Search
Search Results
-
3181. [Article] Daily and alternate day supplementation of urea of biuret to ruminants consuming low-quality forage
Data is limited evaluating infrequent supplementation of urea or biuret to ruminants consuming low-quality forage (<6% crude protein). Therefore, a series of experiments were designed to compare the effects ...Citation Citation
- Title:
- Daily and alternate day supplementation of urea of biuret to ruminants consuming low-quality forage
- Author:
- Currier, Thomas A.
Data is limited evaluating infrequent supplementation of urea or biuret to ruminants consuming low-quality forage (<6% crude protein). Therefore, a series of experiments were designed to compare the effects of daily (D) and alternate day (2D) supplementation of two non-protein nitrogen (NPN) sources (urea or biuret) to ruminants consuming low-quality forage. Experiment 1 was a N balance study using five wethers in an incomplete 5 x 4 Latin square design (five treatments; four 24-d periods) with a 2 x 2 factorial arrangement of treatments (two sources of NPN and two supplementation frequencies) and an unsupplemented control. Supplements, consisting of urea or biuret mixed with ground soy hulls and dried molasses, were isonitrogenous (approximately 26% crude protein; dry matter basis) and offered D or 2D. The 2D supplemented lambs received double the quantity of supplemental N on their supplementation day compared with D lambs; therefore, all D and 2D treatments received the same amount of supplemental N over a 2-d period. Experiment 2 was a 70-d cow performance study using 80 spring-calving cows during the last third of gestation. Cows were stratified by age, body condition score, and expected calving date, and assigned randomly within stratification to one of the five treatments described in Experiment 1 above. They were then sorted by treatment and randomly assigned to 1 of 20 pens (4 cows/pen, 4 pens/treatment). Experiment 3 was a site of digestion study using five ruminally and duodenally fistulated steers to compare D and 2D supplementation of urea or biuret on forage intake, ruminal fermentation, site and extent of nutrient digestion, and rumen microbial efficiency. Five ruminally and duodenally fistulated steers were used in an incomplete 5 x 4 Latin square design with the same treatments described in Experiment 1. The results for Experiment 1 reported that DM, OM, and N intake, DM, OM, and N digestibility, N balance, and digested N retained were greater (P<0.03) for supplemented wethers compared with CON with no difference (P>0.05) because of NPN source or SF. Supplemented lambs had increased plasma urea N (PUN) compared with CON (P<0.01) and urea treatments had greater PUN compared with biuret (P<0.01). Also, PUN was increased (P=0.02) for D compared with 2D treatments. In addition, data suggest that PUN exhibited less fluctuation on the day of a supplementation event for biuret compared with urea. Experiment 2 demonstrated that pre- and post- calving (within 14 d and 24 h of calving, respectively) cow weight and body condition score changes were more positive (P<0.05) for supplemented groups compared with the CON. In Experiment 3, forage OM intake and OM digestibility were not affected (P>0.05) by NPN supplementation, NPN source, or SF. However, total OM and N intake were increased (P<0.01) with supplementation. Duodenal flow of OM tended (P=0.08) to increase with NPN supplementation while N flow was greater (P=0.04) with NPN supplementation compared with the control. In addition, duodenal bacterial N flow was increased with NPN supplementation (P=0.04) and for biuret compared with urea (P<0.01). Bacterial efficiency (g bacterial N/kg OM truly digested in the rumen) was greater for the control compared with NPN treatments (P<0.01) while biuret had greater true N disappearance compared with urea (P=0.01). Intestinal disappearance (% of duodenal flow) of OM and N was not affected by NPN supplementation, NPN source, or SF. However, apparent total tract N digestibility was increased with NPN supplementation (P<0.01) and not affected by NPN source or SF. In addition, ruminal NH₃-N increased (P<0.04) on the day all supplements were provided and the day only daily supplement were provided with supplemental NPN. However, an NPN source x SF interaction (P=0.03) on the day all supplements were provided indicated NH₃-N increased at a greater rate for urea as SF decreased compared with biuret. Ruminal NH₃-N on the day only daily supplements were provided was greater for D compared with 2D (P=0.02). This data suggests that ruminal degradation of biuret to NH₃-N was more moderate and prolonged compared with urea, possibly improving use by ruminal microflora. On the day all supplements were provided, D treatments had increased (P=0.05) ruminal indigestible acid detergent fiber passage rate and ruminal liquid volume compared with 2D treatments. Overall, NPN supplementation when feeding low-quality forage (<6% CP) was more beneficial than compared to a negative control, for increasing efficiency of forage digestion, N use, and animal performance. While at the same time indicating that the infrequent supplementation of urea or biuret was not detrimental to forage nutrient utilization, N efficiency or cow performance. This research will provide researchers and ruminant livestock producers with original information that can be used in designing winter supplementation strategies that decrease supplementation costs. Keywords: Urea, Biuret, Forage, Non-Protein Nitrogen, Supplementation, Frequency
-
3182. [Article] Assimilation of Multi-Sensor Data into Numerical Hydrodynamic Models of Inland Water Bodies
Numerical models are effective tools for simulating complex physical processes such as hydrodynamic and water quality processes in aquatic systems. The accuracy of the model is dependent on multiple model ...Citation Citation
- Title:
- Assimilation of Multi-Sensor Data into Numerical Hydrodynamic Models of Inland Water Bodies
- Author:
- Javaheri, Amir
Numerical models are effective tools for simulating complex physical processes such as hydrodynamic and water quality processes in aquatic systems. The accuracy of the model is dependent on multiple model parameters and variables that need to be calibrated and regularly updated to reproduce changing aquatic conditions accurately. Multi-sensor water temperature observations, such as remote sensing data and in situ monitoring technologies, can improve model accuracy by providing benefits of individual monitoring technology to the model updating process. In contrast to in-situ temperature sensors, remote sensing technologies (e.g., satellites) provide the benefit of collecting measurements with better X-Y spatial coverage. However, the temporal resolution of satellite data is limited comparing to in-situ measurements. Numerical models and all source of observations have large uncertainty coming from different sources such as errors of approximation and truncation, uncertain model inputs, error in measuring devices and etc. Data assimilation (DA) is able to sequentially update the model state variables by considering the uncertainty in model and observations and estimate the model states and outputs more accurately. Data Assimilation has been proposed for multiple water resources studies that require rapid employment of incoming observations to update and improve accuracy of operational prediction models. The usefulness of DA approaches in assimilating water temperature observations from different types of monitoring technologies (e.g., remote sensing and in-situ sensors) into numerical models of in-land water bodies (e.g., reservoirs, lakes, and rivers) has, however, received limited attention. Assimilating of water temperature measurements from satellites can introduce biases in the updated numerical model of water bodies because the physical region represented by these measurements do not directly correspond with the numerical model's representation of the water column. The main research objective of this study is to efficiently assimilate multi-sensor water temperature data into the hydrodynamic model of water bodies in order to improve the model accuracy. Four specific objectives were addressed in this work to accomplish the overall goal: * Objective 1: Propose a novel approach to address the representation challenge of model and measurements by coupling a skin temperature adjustment technique based on available air and in-situ water temperature observations, with an ensemble Kalman filter (EnKF) based data assimilation technique for reservoirs and lakes. * Objective 2: Investigate whether assimilation of remotely sensed temperature observations using the proposed data fusion approach can improve model accuracy with respect to in-situ temperature observations as well as remote sensing data. * Objective 3: Investigate a global sensitivity analysis tool that combines Latin-hypercube and one-factor-at-a-time sampling to investigate the most sensitive model inputs and parameters in calculating the water age and water temperature of shallow rivers. * Objective 4: Propose an efficient data assimilation framework to take the advantage of both monitoring technologies (e.g., remote sensing and in-situ measurements) to improve the model efficiency of shallow rivers. Results showed that the proposed adjustment approach used in this study for four-dimensional analysis of a reservoir provides reasonably accurate surface layer and water column temperature forecasts, in spite of the use of a fairly small ensemble. Assimilation of adjusted remote sensing data using ensemble Kalman Filter technique improved the overall root mean square difference between modeled surface layer temperatures and the adjusted remotely sensed skin temperature observations from 5.6 °C to 0.51 °C (i.e., 91% improvement). In addition, the overall error in the water column temperature predictions when compared with in-situ observations also decreased from 1.95 °C (before assimilation) to 1.42 °C (after assimilation), thereby, giving a 27% improvement in errors. In contrast, doing data assimilation without the proposed temperature adjustment would have increased this error to 1.98 °C (i.e., 1.5% deterioration). The most effective parameters to calculate water temperature were investigated and perturbed among the acceptable range to create the ensembles. Results show that water temperature is more sensitive to inflow temperature, air temperature, solar radiation, wind speed, flow rate, and wet bulb temperature respectively. Results also show in contrast to in-situ data assimilation, remote sensing data assimilation was able to effectively improve the spatial error of the model. Assimilation of in-situ observation improved the model efficiency at observation site. However, the model error increased by time and after less than two days, the model predictions of updated model were the same as base model before data assimilation. Hence, a maximum acceptable error between model and measurements was defined based on the application of model. Remote sensing data were assimilated into the model as they become available to improve the model accuracy for the entire river. In-situ data were also assimilated into the model when the error between model and observations exceeds the maximum error. Results showed that by assimilation of in-situ data one to three times per day, the average daily error reduced up to 58% comparing to situation that in-situ data were assimilated only once. In addition, the average spatial error reduced from 2.59 °C to 0.66 °C after assimilation of remote sensing data.
-
3183. [Article] Young adults' beliefs about and use of herbal supplements in relation to their dietary attitudes and behaviors
Today in the United States, herbal supplements are growing increasingly popular, however, little is known about the safety and efficacy of these products. This study contributes to the growing body of ...Citation Citation
- Title:
- Young adults' beliefs about and use of herbal supplements in relation to their dietary attitudes and behaviors
- Author:
- Koorndyk, Tamberly
Today in the United States, herbal supplements are growing increasingly popular, however, little is known about the safety and efficacy of these products. This study contributes to the growing body of information about the prevalence of herbal supplement use among young adults (18 to 24 years) and the beliefs young adults hold about herbal supplements in relation to their dietary attitudes and behaviors. A self-administered, four-part questionnaire was mailed to a geographically representative sample of 298 young adults (18 to 24 years) residing in Oregon; 205 questionnaires were usable (69% response rate). There was an equal ratio of male and female respondents, half students and half non-students, the majority being Caucasian (93%), with a mean age of 21.5 years. Nearly 60% of the sample reported using herbal supplements (n=122). Thirty-seven percent were sometime users (less than weekly) and 22% were regular users (at least weekly). More female respondents reported using herbal supplements (69%) than did male respondents (49%). Respondents who were White or Asian/Pacific Islander were the only ethnic groups that reported using herbal supplements regularly. Users were more educated than non-users, however use was very similar among students and non-students. Herbal supplement use also was very similar between respondents having different residencies. Familiarity with different herbs was positively related to level of herbal supplement use. Regular users were familiar with the greatest number of herbs, followed by sometime users. Herbal supplement users tended to have more healthful lifestyle characteristics than non-users. Frequency of fast food patronage was negatively related to level of herbal supplement use. The median number of times a fast food restaurant was patronized was lower among regular users of herbal supplements than among those who did not use supplements or used them less often. The median number of times breakfast was eaten also seemed to be slightly higher among regular users than other groups. Other healthful lifestyle characteristics, such as BMI and drinking in moderation, did not tend to be more healthful among herbal supplement users. The results were mixed on smoking behavior. Regular users of herbal supplements were no more or less likely than non-users to smoke, but non-users were less likely than sometime users to smoke. Regular users of herbal supplements tended to think herbal supplements are useful for certain health parameters more often than sometime users and non-users. Most regular users of herbal supplements agreed herbs are useful for maintaining good health (89%) and preventing/treating common illnesses like colds (85%). Almost two-thirds also thought herbs are useful for preventing serious chronic illnesses (61%) and insuring a well-balanced diet (65%). Attitudes toward the effectiveness, convenience, and expense of taking herbal supplements in comparison to eating a balanced diet as ways of staying healthy were related to herbal supplement use. Herbal supplement users did not appear to have positive attitudes towards herbs when comparing herbs to a well-balanced diet. Only 11% of users thought that herbs are more effective than diet as ways to stay healthy, and users were more likely than non-users to think herbs are more expensive ways to stay healthy. However, both levels of users were more likely to think herbal supplements are more convenient than diet. Attitudes about the effectiveness, safety, expense, naturalness, potency, and personal control of taking herbal supplements in comparison to prescription medications was related to level of herbal supplement use. In general the trend was for users to be more likely to have positive attitudes toward herbs and less likely to give a "don't know" answer. Eating the recommended number of food guide pyramid servings of fruits and vegetables as well as eating a greater number of nutrient rich vegetables was not related to herbal supplement use. However, a somewhat higher percentage of herbal supplement users tended to meet the fruit and vegetable recommendations than nonusers of herbal supplements. Stage of change in relation to vegetable intake was related to herbal supplement use. As respondents' herbal supplement use increased, so did the likelihood of classifying themselves into one of the action stages of change for vegetable consumption. Stage of change for fruit consumption was not related to herbal supplement use. Choice to stop using herbs if they were pronounced unsafe by a governmental agency was not related to level of herbal supplement use. However, 17% of sometime users and 16% of regular users reported that they would continue to use herbs even after they were pronounced unsafe by a governmental agency. The results of this study clearly show that there is a high prevalence of herbal supplement use among young adults in Oregon, and those who are using herbal supplements seem to have a strong belief in the herbs they are taking. With the limited knowledge on herbs' safety and efficacy, young adults need to be educated about the herbs they are using. Hopefully, the information from this study can help health professionals identify which young adults might be using herbal supplements in order to educate them on making smart choices about herbs, and smart choices about their overall health. To inform young adults about the herbs they are using, additional research on herbal supplements' potential benefits and harmful side effects is needed.
-
3184. [Article] Constraints to urban park visitation: Conceptual connections and spatial attributes for traditionally well-served and underserved residents
Connecting with nature is associated with social, physical, and emotional benefits such as stress relief, improved physical health, and lower crime. Parks and other natural areas offer spaces in which ...Citation Citation
- Title:
- Constraints to urban park visitation: Conceptual connections and spatial attributes for traditionally well-served and underserved residents
- Author:
- Rushing, Jaclyn R.
Connecting with nature is associated with social, physical, and emotional benefits such as stress relief, improved physical health, and lower crime. Parks and other natural areas offer spaces in which to connect with nature and reap these and other benefits (e.g., family bonding, social events, learning). Despite increasing populations of racial and ethnic minorities in the United States of America, these groups are underrepresented in many outdoor recreation activities and in visitation to many parks and other protected areas. This underrepresentation and other attributes of park visitation can be partially explained through the theoretical lens of constraints to recreation. Constraints are factors that limit participation, affect leisure preferences, and / or reduce enjoyment and satisfaction with recreation experiences. Examples of constraints include inability to afford park fees, fear of crime in parks, and lack of available leisure time. This thesis contains two standalone articles focusing on resident constraints to visiting urban parks and other natural areas in the Portland, Oregon (USA) metropolitan region. These articles examine: (a) the most common constraints to visiting these parks and natural areas, and whether these constraints vary between traditionally well-served (i.e., white majority residents) and underserved (i.e., ethnic and racial minorities) populations; (b) relationships among constraints, park visitation, and place attachment for both of these groups of residents; and (c) how constraints groups, different types of constraints, and resident characteristics (e.g., minorities) are distributed spatially across this metropolitan region. Data were obtained from mail and online questionnaires completed by two samples of residents in Clackamas, Multnomah, and Washington counties: (a) a proportionate random sample of residents mostly targeting the following groups: African Americans / Blacks, American Indians, Asians, Hispanics / Latinos, Middle Eastern peoples, and Slavic / Eastern European peoples (i.e., probability sample); and (b) a convenience sample of Opt-In panel members (i.e., nonprobability sample). Questionnaires were completed by a total of 3,328 residents across these samples, and the data were weighted by the most recent Census based on county, age, sex (male, female), and education to be representative of adult residents in this region. Race and other demographics were consistent with the Census after weighting. Results of the first article showed that the primary constraints to visiting parks and natural areas in this urban region were being too busy to visit, limited knowledge about Metro parks, and lack of access to these places (Metro parks are managed by Metro, which is the main regional government for Clackamas, Multnomah, and Washington counties). There were no differences in these constraints and most other constraints between traditionally underserved and well-served populations. Traditionally underserved residents, however, were significantly more constrained than the well-served residents were by race and cultural issues at parks, as well as lack of facilities and services at Metro parks. Traditionally well-served residents visited all parks and natural areas in the region significantly more often than did the underserved residents, but there were no differences in visitation to Metro parks or their favorite park. There were also no differences between the two groups in their attachment to their favorite park. Constraints and visitation explained 15% of the variance in attachment for well-served residents and 38% for underserved residents, and constraints explained 4% of the variance in visitation for well-served residents and 26% for underserved residents. The strongest negative predictor of attachment for well-served residents was Metro parks are not the best places, followed by limited access to these places and disinterest in visiting parks and natural areas. The strongest positive predictor for well-served resident attachment was frequency of visitation, followed by race and cultural issues at Metro parks, and lack of facilities and services in these areas. For underserved residents, the strongest negative predictor of attachment was costs followed by Metro parks are not the best places and limited knowledge about these places. Positive predictors of attachment for these residents included frequency of visitation and lack of facilities and services at Metro parks. The only predictor of visitation to their favorite park for well-served residents was fear of visiting other areas (positive relationship), whereas visitation for underserved residents was negatively associated with limited access to Metro parks and positively associated with costs of visiting other areas. The second article used a Geographic Information System (GIS) and hot spot analysis of the survey data to determine any spatial patterns in constraints groups, different types of constraints, and resident characteristics (e.g., minorities). Results revealed two major trends: (a) in the northeast area of the region, there is a clustering of minority residents overlapping with the most constrained hot spots and these residents were most affected by constraints associated with health and lack of recreation partners; and (b) residents in the southwest area of the region were most affected by constraints associated with limited knowledge and access to parks. Specific implications of these results for both management and research are discussed in this thesis. In general, however, these results may inform local agency objectives associated with reaching and engaging various populations, including ethnic and racial minorities. These findings also contribute to the literature by exploring relationships among constraints, park visitation, and attachment between traditionally well-served and underserved populations, and also by applying a GIS analysis of survey data to understand spatial aspects of constraints for each of these populations.
-
Two research projects comprise this thesis. The first project investigated modifying the hormone dosing strategy traditionally used in superovulating donor cows for an embryo collection to decrease drug ...
Citation Citation
- Title:
- Modifying the Hormone Strategy for Superovulating Donor Cows to Reduce Drug Costs without Decreasing the Number of High Quality Transferable Embryos Recovered
- Author:
- Gomes, Maria (Maria Kristine)
Two research projects comprise this thesis. The first project investigated modifying the hormone dosing strategy traditionally used in superovulating donor cows for an embryo collection to decrease drug costs without decreasing the number of high quality, transferable embryos recovered. The objective of this project was to evaluate the number and quality of embryos recovered from donor cows superovulated with a reduced dose of the pituitary gonadotropic hormone, follicle stimulating hormone (FSH), and a greater dose of the hypothalamic releasing hormone, gonadotropin releasing hormone (GnRH). In Experiment 1, 24 crossbred beef cows from the Oregon State University Beef Cattle Ranch were assigned to one of four superovulation treatment groups according to age and parity: 1) 400 mg FSH and 100 μg GnRH (the traditional doses), 2) 400 mg FSH and 200 μg GnRH, 3) 200 mg FSH and 100 μg GnRH, or 4) 200 mg FSH and 200 μg GnRH. Embryos were collected non-surgically 7 d after estrus onset and scored for stage of development and quality using a four-rank grading scheme. In Experiment 2, 12 crossbred beef cows from the Oregon State University Beef Cattle Ranch were superovulated twice with either 1) 400 mg FSH and 100 μg GnRH or 2) 200 mg FSH and 100 μg GnRH. Embryos were collected non-surgically as described in Experiment 1 and good to excellent quality late morulae to blastocysts were cultured, one embryo per 15-microliter drop, for 8 d. At 24-h intervals, embryos were evaluated for viability and overall development and transfered to a fresh micro-drop and conditioned medium was recovered. Conditioned media were assayed for plasminogen activator (PA), a protease correlated with embryo cell number and development to advanced cell stages. In Experiment 1, cows superovulated with 200 μg GnRH produced more unfertilized ova (P = 0.02) than cows superovulated with 100 μg GnRH. Cows superovulated with 200 mg FSH produced a higher percentage (P = 0.07) of transferable embryos and a lower percentage (P = 0.10) of degenerate embryos than cows superovulated with 400 mg FSH. Superovulating cows with the reduced FSH and GnRH doses (200 mg and 100 μg, respectively) yielded fewer total transferable embryos (1.8 embryos) but a greater percentage of transferable embryos at a reduced cost compared to the traditional dose ($24 vs $31 per embryo, respectively). Increased GnRH dosing had a negative effect on transferable embryos and the reduced FSH and increased GnRH dosing was not cost effective. In Experiment 2, cows superovulated with 400 mg FSH produced more unfertilized ova (P = 0.08) than cows superovulated with 200 mg FSH. More (P=0.04) embryos recovered from cows treated with 200 compared to 400 mg FSH developed to the hatched blastocyst stage in culture. Embryos recovered from cows treated with 200 compared to 400 mg FSH also developed to the expanded blastocyst stage sooner (P = 0.08). Embryos collected from cows receiving 200 mg FSH produced more (P = 0.04) PA in the first round of superovulation compared to 400 mg FSH and both doses in the second round. Similar to Experiment 1, the 200 mg FSH dose yielded fewer total transferable embryos in the first round of superovulation but at a reduced cost compared to the 400 mg dose ($25 vs $37 per embryo, respectively). Collectively, these data suggest higher FSH dosing is likely inducing ovulation of poorer quality ova which either fail to fertilize or, if fertilization occurs, may generate a reduced percentage of competent embryos. The reduced FSH dose not only contributes to a reduced cost but may also provide more embryos with a greater likelihood of pregnancy establishment. The second project in this thesis attempted to develop a dipstick-style enzyme assay to assess embryo viability prior to transfer. The objective of this project was to develop a dipstick that rapidly quantified PA production by an embryo and could be used on the farm for an embryo collection and transfer. Dipsticks were constructed by cutting and mounting 5 X 5 mm squares of cellulose acetate, chromatography paper, glass fiber membrane or nitrocellulose on the end of 5 X 25 mm plastic strips. Five microliters of 1, 10 or 50mM of the tripeptide glutamic acid-glycine-arginine (EGR; C₂₇H₃₆N₈O₇•CH₃COOH), a colorimetric substrate for urokinase (UK), were pipetted onto the 5 X 5 mm squares and dried. Dipsticks were incubated in 25-μL of culture medium containing 0, 1, 10, or 100 IU UK/mL or embryo-conditioned medium (ECM) and visually observed for color development at 30-min intervals for up to 90 min. Color development was scored using the following 3-point system where: 0 = absence of yellow, 1 = light yellow and 2 = bright yellow. Dipsticks were able to detect EGR cleavage in 10 and 100 IU/mL UK after 90 and 30 min of incubation, respectively, but no color was observed in dipsticks incubated in ECM. A second approach was developed using a 96-well plate. Twenty-five microliters of 1, 5, 10, 20 or 50 mM EGR were combined with 25-μL of culture mediumcontaining 0, 1, 10, or 100 IU UK/mL or ECM and observed for color development visually and photometrically at OD 405 using an ELISA plate reader at 30-min intervals for up to 120 min. Color development was visually observed in 1, 5, 10 and 50 mM EGR after 30 min of incubation with 100 mM UK/mL but no color was observed in wells containing ECM. However, when the plates were evaluated photometrically EGR cleavage was detected in wells containing ECM and 50 mM EGR after 30 min of incubation. Although the PA dipstick enabled visual detection of EGR cleavage by 10 and 100 IU/mL UK, it was not sensitive enough to detect PA in ECM. The 96-well plate assay was successful in detecting PA in ECM after 30 min of incubation but only photometrically. To use the plate-based assay would require the embryo transfer practitioner to have an ELISA plate reader on hand and the expense associated with such an instrument may limit its on farm application.
-
The rare earth elements (REEs) have been established as powerful tracers for a range of physiochemical processes occurring in the natural environment. They also hold significant economic importance as ...
Citation Citation
- Title:
- Unraveling the Diagenetic Cycling and Sequestration of Rare Earth Elements (REEs) in Marine Sediments to Understand REE Accumulation in Ancient Shales
- Author:
- Yang, Jon
The rare earth elements (REEs) have been established as powerful tracers for a range of physiochemical processes occurring in the natural environment. They also hold significant economic importance as many technological advancements are reliant upon the REEs for their unique magnetic, luminescent, and electrochemical characteristics. In sedimentary settings, understanding the cycling of the REEs is necessary to fully evaluate the application of the REEs as geochemical tracers and to understand the individual factors that may influence the magnitude and signature of REE accumulations. The association of the REEs with the major element cycles of iron (Fe) and phosphorus (P) have been extensively studied in modern sedimentary environments, but there remain uncertainties on the long-term accumulation and signature of the REEs. In particular, our knowledge of how the preserved record of the REEs in ancient marine black shales is derived from the cycling of REEs observed within modern sediments remains unclear. For these marine black shales, this gap in our knowledge has important ramifications for the potential use of the REEs as geochemical tracers of processes such as groundwater flow or hydraulic fracturing activity as well as the potential sourcing of REEs for economic extraction. In this dissertation, I attempt to refine our understanding of REE accumulation in ancient black shales, and how the original signals of the diagenetic cycling of REEs may be preserved, by using sequential extraction techniques to isolate individual reactive components in the sediments. Based on documented associations of the REEs and authigenic phosphate minerals in sedimentary systems, I first investigated the preserved record of P in two ancient black shales to unravel the environmental parameters that lead to the sequestration of P as carbonate fluorapatite (CFA) (Chapter 2). This authigenic mineral form is considered the main sink term of reactive P from the marine system, and the preserved record of CFA and other components of the P system may help understand the cycling of P during the deposition of these ancient black shales. Using the preserved signals of P cycling in the individual components of the P system of the ancient black shales, I estimated paleo-benthic P fluxes to evaluate how the sedimentary cycling of P may have impacted the nutrient delivery to the depositional basin. During the deposition of the Marcellus black shale formation in the Devonian Appalachian Basin, I estimated paleo-benthic inputs of P from the depositional area of the formation that were within the ranges of P delivered from large river systems such as the pre-anthropogenic Mississippi and Mackenzie rivers. These estimates suggest that a return flux of P from the sediments could have been a significant source of nutrients to the basin and provide support for a positive feedback mechanism suggested for epeiric, anoxic basins where a benthic flux of P could help stimulate primary productivity in the surface, leading to a greater drawdown of oxygen in deeper waters, and helping to maintain anoxic conditions in the basin that may enhance organic matter preservation. In the next chapter, I add in the signals of the sedimentary REE cycle preserved in ancient black shales in association with the preserved components of the P cycle (Chapter 3). In addition to the two blacks shales analyzed in Chapter 2 for the individual components of the P system, I analyzed the whole-rock REE content of black shales ranging in age from Jurassic to Devonian and representing a range of depositional environments. In these black shales, authigenic carbonates and fluorapatites hosted the majority of the REEs in sediment intervals with active authigenic mineral formation. Based on published relationships between REEs in diagenetic coatings and pore waters in modern sediments, I inferred from the preserved REE patterns of authigenic phases in black shales that the recorded signature reflects diagenetic zonation, where middle REE-enrichments might record the signal of Fe-(oxyhydr)oxide dissolution and heavy REE- enrichments might record the later diagenetic signal of methanogenesis. In sedimentary intervals where authigenic phases were not prevalent, which represents the majority of the black shale samples investigated, the REE signal was determined by remnant organic matter hosting the light REEs and siliciclastic material hosting the heavy REEs. Although these samples resembled typical globally average shale patterns of the REEs, a closer inspection of the components of the REE system suggest that average values of shale may be an amalgamation of different REEs phases. While the connections between the cycling of P and the REEs have been investigated in Chapters 2 and 3, the connections with the cycling of Fe, which have also been demonstrated to strongly influence the REEs, are absent due to the labile nature of the reactive Fe components that are not preserved in the black shales. Thus, in the final chapter of the dissertation, I describe the REE content measured in reactive Fe and P phases from modern sediments near the island of South Georgia (sub-Antarctic) that receive a large input of reactive Fe through glacial output (Chapter 4). Despite this large input of reactive amorphous Fe-(oxyhydr)oxide phases, the majority of the REEs measured in the sediments were hosted in refractory siliciclastics, with less than 15 % of the REEs in labile (extractable) phases. The low sedimentary REE pool associated with the labile amorphous Fe phase likely reflects deposition under a very shallow (< 300 m) water column that precludes scavenging of REEs from seawater. This inference is consistent with measurements I performed on the dissolved REEs in the water column at South Georgia, that show relatively lower concentrations compared to deeper waters in the Southern Ocean that experience greater degrees of particulate scavenging. For the REEs that were measured within the labile amorphous Fe and P phases, however, I found that the fidelity of the preserved REE record is also impacted by the ability of the REEs to transfer from labile phases to more permanently stable mineral phases. With increasing sediment depth, the REEs demonstrated a transfer from relatively amorphous phases of Fe-(oxyhydr)oxides to more crystalline carbonate components of the sediments, preserving a characteristic middle-REE-enrichment of Fe-(oxyhydr)oxides. Additionally, the REEs also showed a transfer from more labile, amorphous forms of Fe- (oxyhydr)oxides such as ferrihydrite/lepidocrocite into more crystalline forms such as goethite/hematite phases with depth. Collectively, the chapters of this dissertation describe the formation of REE signatures from the initial signals of diagenesis in marine sediments to the preserved record observable today in ancient marine black shales. The major element cycles of Fe and P strongly influence the cycling of REEs both in the origination of REE signatures (e.g., middle-REE-enrichments from Fe-(oxyhydr)oxides) and preservation of diagenetic signals (e.g., middle- to heavy-REE-enrichments in authigenic carbonates and fluorapatites). The insights learned about REE accumulation in marine black shales, which I present in this dissertation might potentially assist in evaluating which phases of the black shales are accessed during groundwater or hydraulic fracturing studies as well as guiding targets for potential REE extraction.
-
Wheat (Triticum aestivum) is a globally traded staple food crop. The diverse and pleasing nature of wheat-derived products is a result of the complex interactions of the polymeric components from the wheat ...
Citation Citation
- Title:
- Two Studies Addressing Practical Needs of Wheat Farmers, Processors, and Breeders : Changes in Falling Number and Alpha-amylase During Grain Storage, and Improved Predictions of Wheat-flour Dough Properties
- Author:
- Adams, Mike R.
Wheat (Triticum aestivum) is a globally traded staple food crop. The diverse and pleasing nature of wheat-derived products is a result of the complex interactions of the polymeric components from the wheat endosperm. Changes in the functionality of these polymeric components, as a result of changes in growing conditions or different genetics, impacts market price and end-product quality and directly affects farmers and processors. Wheat is of particular economic importance to the U.S. Pacific Northwest and, specifically, to the state of Oregon. Providing quality wheat for export is paramount to the survival of the Oregon wheat industry. This dissertation focuses on wheat quality from the perspective of serving the practical needs of farmers, processors, and wheat breeders. The first study, split into two portions, concerns pre-harvest sprouting (PHS) and grain storage. PHS increases alpha amylase (αA) activity in wheat, which, in excess, reduces wheat end-product quality. Falling Number (FN) is the primary test used by industry to gauge PHS damage in wheats. Direct measurement of αA activity is the fundamental frame of reference. The objective of these studies was to determine if FN and αA activity of wheat samples changed during storage and if changes were a function of storage time, storage temperature, and degree of PHS damage. Samples from three Idaho locations were used. These captured a wide range of PHS degree, and therefore, wide ranges of FN values and αA activities. Samples were subdivided and stored at -20°C, +20°C, and +40°C. Low FN values and high αA activities were observed in soft wheats from locations that had rain events prior to harvest. Overall, FN and αA activity had the curvilinear relationship expected from the literature, indicating the validity of the sample set with regard to the FN/αA relationship. Changes in FN and αA activity were observed over a 90 day period of grain storage. FN differed between growing environments, wheat varieties, and storage temperatures. αA activity also differed between growing environments and wheat varieties, but not between storage temperatures. Highest rates of increase in FN were observed in hard wheats with high initial (day 0) FN values. Lowest rates of increase in FN were observed in soft wheats with low day 0 FN values. This contrasted with the changes that occurred in αA activity. Decreases in αA activity over storage time were most prevalent in soft wheats, particularly sprouted soft wheats (i.e. those with day 0 αA activities > 0.1 Ceralpha Units: CU). There were small decreases in αA activity in hard wheats but the distinction between high and low αA activity samples was not as evident as in the soft wheats because the vast majority of hard wheat samples tested had αA activities < 0.1 CU. Decreases in αA activity were in general not associated with corresponding increases in FN values over grain storage time. Increases in FN values occurred at a higher rates as storage temperature increased, particularly in hard wheats with high day 0 FN. Grain storage was successful as a way to raise FN values to > 300 s in very few cases. Storage was not effective in decreasing αA activity from > 0.1 CU to < 0.1 CU. Increases in FN over storage time for the hard wheats significantly differed between locations. However, decreases in αA activities over storage time for the hard wheats were not significantly different between locations. This again highlights a lack of correspondence between increased FN and decreased αA activity, suggesting that these two factors are somewhat decoupled when looking at changes in stored grain. Temperature-induced gluten crosslinking was explored as possible explanation for drastic increases in unsprouted hard wheat FN observed in samples from one location. Total polymeric protein (TPP) content was assessed at the end of the study for unsprouted hard wheats stored at +40°C and -20°C as well as sprouted hard wheats from stored at -20°C. TPP content was assessed as % large unextractable polymeric proteins (%LUPP) and % total unextractable polymeric proteins (%TUPP) using size exclusion high performance liquid chromatography (HPSEC). TPP content was not significantly different between storage temperatures for wheat varieties from the same location. %TUPP, but not % LUPP, was significantly lower in wheat varieties affected by PHS. Changes in FN at high storage temperature were not likely due to increased protein crosslinking. The second study aimed to validate the use of a rapid method for predicting dough strength at early generations in hard wheat breeding programs. Early generation quality screening improves breeding program efficiency. Hard wheats are used to make leavened bread products. The gluten proteins, particularly high molecular weight glutenin subunits (HMW-GS), form large, ramifying networks called the glutenin macropolymer (GMP). High GMP content is associated with increased dough strength and bread quality. Genetic differences in HMW-GS, and by inference, GMP, are responsible for differing dough properties between varieties. The Mixograph is used to measure dough mixing properties and predict end-product quality in breeding programs. GMP can also be measured as total polymeric protein (TPP) via HPSEC. The Solvent Retention Capacity (SRC) test has been proposed to predict hard wheat quality, specifically lactic acid SRC (LASRC). The objectives of this research were to provide preliminary information on the usefulness of using LASRC, on its own, to predict dough mixing properties, specifically as applied to early generation screening in a wheat breeding program, and to assess the relationship between LASRC and TPP. Wheat samples were categorized by flour protein concentration (FPC). Mixograph analysis was used as the baseline for dough properties and was analyzed both by eye and by the proprietary Mixsmart software. TPP content was assessed as %LUPP and %%TUPP. As a result of redundancy between the two TPP measures, only %LUPP was used for statistical analysis. Dough mixing parameters were slightly better correlated with LASRC than %LUPP. Correlations between LASRC, %LUPP, and dough mixing parameters were different between FPC categories, particularly in low FPC samples. A strict cutoff of 115% LASRC effectively screened out the bottom 10% of low quality hard wheats but retained a nearly equal amount of low quality hard wheats that would have been screened out by mixograph analysis. LASRC and %LUPP are not likely to be effective predictors of dough properties, but may have some value to screen for hard wheat quality in the early generations of a wheat breeding cycle.
-
The purpose of this study was to determine the readability of three series of selected fourth, fifth and sixth grade social studies textbooks, a total of nine textbooks. Two measurements were utilized: ...
Citation Citation
- Title:
- The readability of selected fourth, fifth and sixth grade social studies textbooks as determined by the Fry Readability Graph and group informal reading inventories
- Author:
- Pruitt, Janet Louise McCracken, 1930-
The purpose of this study was to determine the readability of three series of selected fourth, fifth and sixth grade social studies textbooks, a total of nine textbooks. Two measurements were utilized: a readability formula (Fry Readability Graph; Knapp, 1971), and group informal reading inventories. The Fry Graph was applied to ten randomly selected 100-word passages in each text; proper nouns were included in the computations. The group informal reading inventories were constructed from the same textbooks on passages not previously taught. The tests were administered in May to 1467 students in 70 randomly selected classrooms. Procedures Both descriptive and inferential statistics were used to analyze the data. Readability levels derived by the application of the Fry Graph were reported for each text:, as was the range of readability within each text and the deviation of each sample from the overall readability of the textbook. The test scores from the group informal reading inventories were first reported in terms of the per cent of subjects scoring at the independent level (90, 95, 100 per cent), the instructional level (65, 70, 75, 80, 85 per cent) and the frustration level (60 per cent or lower) for the sample. Mean test scores were also computed for the sample, the urban and rural subsets, for each grade level, and for each publisher. To determine if there were significant differences among the subsets, the following null hypotheses were formulated: H1 There are no significant differences in the mean scores of the urban and rural subjects. H2 There are no significant differences in the mean scores of the subjects in grades four, five and six. H3 There are no significant differences among the mean scores of the subjects tested on the D. C. Heath, the Silver Burdett or the Benefic Press social studies series. The differences among groups were statistically analyzed at the .05 and .01 levels of significance by the pooled variance t-test or by the analysis of variance. When the analysis of variance resulted in a significant F value, the multiple range test was applied to determine the exact location of the mean difference. Findings of the Study Fry Readability Graph 1. Two textbooks, the fourth grade textbooks published by D. C. Heath and by Silver Burdett, had readability levels in agreement with the publishers' designated grade level. The remaining seven textbooks had readability levels one to four years above the designated grade level. 2. The average range of readability within the textbooks was 6.2 years with little evidence of a gradation from less difficult to more difficult reading material. 3. When the three series were ranked according to their relative difficulty on the basis of the Fry readability levels, it was determined that: a. The D. C. Heath series is the least difficult. b. The Silver Burdett series occupies an intermediate position. c. The Benefic Press series is the most difficult. Group Informal Reading Inventories 1. For the total sample 9.41 per cent of the subjects scored at the independent level, 32.04 per cent scored at the instructional level, and 58.55 per cent scored at the frustration level. The mean test score was 54.82 per cent. 2. The mean score (56.64 per cent) of the urban subjects was significantly higher (.01 level) than the mean score (52.35 per cent) of the rural subjects with a t value of 3.30. H1 was rejected. 3. The mean score for grade four was 50.35 per cent; for grade five, 53.96 per cent; and for grade six, 58.09 per cent. The analysis of variance resulted in a significant (.01 level) F value of 11.25. H2 was rejected. 4. The mean scores by publisher were: D. C. Heath, 55.88 per cent; Silver Burdett, 55.77 per cent; and Benefic Press, 50.38 per cent. The analysis of variance resulted in a significant (.01 level) F value of 5.47. The multiple range test showed significant differences between the Benefic Press and D. C. Heath series (.01 level) and between the Benefic Press and Silver Burdett series (.01 level). There were no significant differences between the D. C. Heath and Silver Burdett series. H3 was rejected. Implications 1. The findings of this study did not differ in any substantial way from the results reported by earlier investigators. Further studies of the readability of social studies textbooks similar in content to the three series analyzed in this investigation is not warranted. 2. Additional research is needed to determine if systematic instruction resembling the procedures prescribed for a well-developed basal reading lesson will significantly affect the ability of students to comprehend social studies textbooks. Recommendations 1. Current knowledge regarding the nature of concept development should be a major consideration for curriculum decisions in the social studies. Piaget's findings regarding the cognitive functioning of elementary school students provide insight regarding the capabilities of this age group. 2. Instructional alternatives that diminish heavy reliance on the textbook should be afforded a fair trial in the classroom, e.g., simulation and gaming (Cuetzkow, 1962; Inbar, 1972), process analog (Fielder, 1967; Joyce, 1972), role playing (Shaftel, 1967), problem solving (Fenton, 1967; Shaftel, 1967), inquiry approaches (Suchman, 1964; Clements, Fielder, Tabachnick, 1966), and inductive development of concepts and generalizations (Taba, 1966; Fenton, 1966; Hanna, 1965). 3. A publicly financed agency staffed by expert analysts and equipped with the necessary resources should be established to provide analysis services to publishers and to determine the difficulty level of all instructional materials as they appear on the market (Bormuth, 1971). 4. Pilot editions of all new textbooks should be field tested with a cross section of students using procedures similar to those utilized by the publishers of standardized tests. 5. When classroom teachers make reading assignments in social studies textbooks, they should faithfully adhere to the same procedures that are prescribed for a well-developed basal reading lesson.
-
3189. [Article] Assessing equity in health system finance and health care utilization : the case of Chile, and a model to measure health care access
Chile has experienced great success in terms of economic growth in the last decades. This growing economy brings changes in the Chilean health care system. Its health care system was primarily funded by ...Citation Citation
- Title:
- Assessing equity in health system finance and health care utilization : the case of Chile, and a model to measure health care access
- Author:
- Nunez Mondaca, Alicia Lorena
Chile has experienced great success in terms of economic growth in the last decades. This growing economy brings changes in the Chilean health care system. Its health care system was primarily funded by state sources until 1981, when a major reform was introduced that established new rules for the health insurance market. Since then, Chile has a public-private mixed health care system, both in financing and delivery of services. Citizens can choose for coverage between the Public National Health Insurance and the Private Health Insurance system. However, these systems have a common funding source coming from the mandatory contribution of employees, equivalent to 7% of their taxable income with an approximate limit of US$2,800 dollars. One of the more important Chilean health reforms towards the establishment of social guarantees was effective on July 2005, when the Regime of Explicit Health Guarantees, also known as Plan AUGE became effective. Plan AUGE is a health program that benefits all Chileans without discrimination of age, gender, economic status, health care, or place of residence. This plan includes the 69 diseases with higher impact on Chilean population in its different stages, but with feasibility of effective treatments. Changes in the health care system and its last reform brought questions about their impact on the distribution of health care services throughout country. Is Chile moving towards a better and more equitable health care system? The main purpose of this thesis is to investigate equity in health system finance and health care utilization as well as to explore alternative measurement of access to health care in Chile. The first two manuscripts examine equity issues in Chile. The purpose of the first one is to assess equity in health system finance in Chile, accounting for all finance sources. While equity in health system finance has been well studied in OECD countries, there are still few published empirical studies on Latin American health care systems, where there tends to be a wider gap in income-wealth distribution among states. This gap may increase the financial burden for people in the lower spectrum of income groups, which is the main concern in the first manuscript. It will focus on identifying policy variables that may contribute to more equitable distribution of the financial burden in health care. The equity principle we adopt for this study is the ability to pay principle. Based on this, we explore factors that contribute to inequities in the health care system finance and issues about who bears the heavier burden of out-of pocket (OOP) payment, progressivity of OOP payment, and the redistributive effect of OOP payment for health care as a source of finance in the Chilean health care system. Our analysis is based on data from the National Socioeconomic Survey (CASEN), and the 2006 National Survey on Satisfaction and OOP payments. Results from this study provide comprehensive understanding of the financial burden of health care in Chile. This study identified evidence of inequity, in spite of the progressivity of the health care system. Furthermore, our assessment of equity in health system finance identified relevant policy variables such as education, insurance system, and method of payment that should be taken into consideration in the ongoing debates and research in improving the Chilean system. Such findings will also benefit other Latin American countries that are concerned about equity in health system finance. The purpose of the second manuscript was to assess equity in health care utilization in Chile. Secondary data analyses from the National Socioeconomic Survey (CASEN) were performed to estimate the impact of different factors including AUGE in the utilization of health care services. We used a two-part model for the analysis of frequency of health care use in the country. Four other separate two-part models were also specified to estimate the frequency of use of preventive services, general practitioner services, specialty care and emergency care. An assessment of horizontal equity was also included. Results suggest the presence of pro-rich inequities in the use of medical care. The estimation of the two-part model found key factors affecting utilization of health care services such as education and the implementation of the AUGE program. These findings provide timely evidence to policy-makers to understand the current distribution and equity of health care utilization, and to strengthen availability of health services accordingly. The third manuscript was motivated by the previous findings. Its purpose was to explore an alternative measurement for health care access. The majority of studies nowadays use a single proxy to estimate access: the use of health care services. However, we saw many limitations on this approach since it only considers people that are already using the system and ignores those that are not. The final manuscript proposed a model to estimate access to health care services based on communitarian claims. The model identified barriers to health care access as well as the preferences of the community for priority settings.
-
3190. [Article] All in a DNA's work : conservation genetics and monitoring of the New Zealand endemic Maui's and Hector's dolphins
The critically endangered Maui's dolphin (Cephalorhynchus hectori maui) and the endangered Hector's dolphin (C. h. hectori) are endemic to the coastal waters of New Zealand, where their primary threat ...Citation Citation
- Title:
- All in a DNA's work : conservation genetics and monitoring of the New Zealand endemic Maui's and Hector's dolphins
- Author:
- Hamner, Rebecca Marie
The critically endangered Maui's dolphin (Cephalorhynchus hectori maui) and the endangered Hector's dolphin (C. h. hectori) are endemic to the coastal waters of New Zealand, where their primary threat is fisheries-related mortality. The Maui's dolphin is among the most critically endangered cetaceans in the world, with its remnant population primarily concentrated in approximately 140 km along the central west coast of New Zealand's North Island. Its closely related sister subspecies, the Hector's dolphin, is more abundant and offers a useful comparison for studying the Maui's dolphin. My work used genetic tools to examine demographic and genetic parameters relevant for conservation considerations regarding Maui's and Hector's dolphins, as well as to build upon past genetic baselines for the purpose of long-term genetic monitoring of these subspecies. Three genetic datasets formed the basis for most analyses: (1) Maui's 01-07, including 54 Maui's dolphin individuals sampled between 2001 and 2007 (n = 70 biopsies, 12 beachcast); (2) Maui's 10-11, including 40 Maui's dolphin individuals sampled in 2010 and 2011 (n = 69 biopsies, 1 beachcast); and (3) Hector's CB11-12, including 148 Hector's dolphin individuals sampled in Cloudy Bay in 2011 and 2012 (n = 263 biopsies). Microsatellite genotypes were used to identify individuals for a genotype recapture abundance estimate of individuals age 1⁺ (N₁₊) and for the estimation of effective population size (N[subscript e]). Both populations exhibited a high N[subscript e] relative to N₁₊, consistent with expectations given their life history characteristics and the limited data available for other dolphin species. The abundance of Maui's dolphins was confirmed to be very low, Maui's 10-11 N₁₊ = 55 (95% CL = 48 - 69), and as expected, it had much lower linkage disequilibrium N[subscript e] (61, 95% CL = 29 - 338) than Hector's CB11-12 (N[subscript e] = 207, 95% CL = 127 - 447; N₁₊ = 272, 95% CL = 236 - 323). The slightly higher Ne/N₁₊ ratio of the Maui's dolphin compared to the Hector's dolphin is consistent with a recent decline in the Maui's dolphin. Although the point estimates of both N[subscript e] and N₁₊ decreased between the two Maui's dolphin datasets (Maui's 01-07: N[subscript e] = 74, 95% CL = 37 - 318; N₁₊ = 69, 95% CL = 38 - 125), the confidence intervals widely overlapped. Maui's 10-11 had significantly fewer alleles (average 4 alleles/locus) and lower heterozygosity (H₀ = 0.316, H[subscript e] = 0.319) than Hector's CB11-12 (average 7 alleles/locus, H₀ = 0.500, H[subscript e] = 0.495; all P <0.001). Interestingly, one microsatellite locus (PPHO104) had anomalously high diversity (31 to 63 alleles) in both Hector's and Maui's dolphins and appears to be influenced by diversifying selection. The observed and expected heterozygosity, internal relatedness, and F[subscript IS] of Maui's dolphins all showed patterns consistent with a decline of the subspecies, although none differed significantly over the short time interval between the two datasets collected in 2001-07 and 2010-11. The lack of significant decline in any of the parameters analyzed for Maui's dolphins is not surprising given the low power to detect a low to moderate decline over the short interval (<1 generation) between the two sampling periods. Compared to minimum viable effective population sizes proposed to guide management decisions, the Maui's dolphin has declined below the recommended threshold of N[subscript e] = 50, recently increased to N[subscript e] ≥100, thought to be necessary to avoid inbreeding depression in the short term (5 generations, ~65.2 years for Maui's and Hector's dolphins). Additionally, both the Maui's dolphin and Cloudy Bay Hector's dolphin populations are below the recommended threshold of N[subscript e] = 500, recently increased to N[subscript e] ≥1000, thought to be necessary to preserve long-term evolutionary potential. This is less of a concern for the Cloudy Bay Hector's population, which is thought to maintain gene flow with neighboring populations. However, for the small, isolated Maui's dolphin population, inbreeding depression is likely to be an increasing concern. Furthermore, each Maui's dolphin individual holds a disproportionate amount of the total genetic variation of the subspecies and would represent a disproportionately large demographic and genetic loss if it died before realizing its reproductive potential in the population. There is, however, potential for genetic restoration by interbreeding with Hector's dolphins, as genetic monitoring of Maui's dolphins revealed the first contemporary dispersal of four (two living females, one dead female, one dead male) Hector's dolphins into the Maui's dolphin distribution. Two Hector's dolphins (one dead female neonate, one living male) were also sampled along the North Island's southwest coast, outside the presumed range of either subspecies. Together, these records provide evidence of long-distance dispersal by Hector's dolphins (≥400 km) and the possibility of an unsampled Hector's dolphin population along the southwest coast of the North Island or northern South Island. These results highlight the value of genetic monitoring for subspecies lacking distinctive physical appearances, as such discoveries are not detected by other means but have important conservation implications. Although the Maui's dolphin is critically endangered, it is not necessarily doomed to extinction. The subspecies appears to be maintaining an equal sex ratio and connectivity within its remnant range, and the highly diverse locus PPHO104 could potentially offer clues to an inbreeding avoidance mechanism. If Maui's dolphins interbreed with the recently identified Hector's dolphin immigrants, it could provide genetic restoration, enhancing chances of long-term survival of the Maui's dolphin. Continued genetic monitoring and examination of recovered carcasses for phenotypic signs of inbreeding are important for gauging genetic threats to the survival of Maui's dolphins, as well as determining if any Hector's dolphin populations appear to be declining toward the critically endangered state of the Maui's dolphin. The results of this work contributed to the decision by the New Zealand Department of Conservation and Ministry for Primary Industries to conduct an updated risk assessment for Maui's dolphins and accelerate the review of the Maui's Dolphin Threat Management Plan. Consequently, commercial and recreational set net restrictions were extended slightly to reduce entanglement risk to Maui's dolphins utilizing the southern part of their distribution, as well as any Hector's dolphins that disperse north into that area. The results related to the population of Hector's dolphins in Cloudy Bay provide information that will contribute to the upcoming review of the Hector's dolphin component of the Threat Management Plan.