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781. [Article] A study of the accuracy in the methods of sampling, preserving, and testing milk for fat at Oregon milk plants
A study was undertaken to determine, by methods and equipment, the variations between of sampling, preserving, and testing milk for fat during the various seasons of the year, and to try and solve the ...Citation Citation
- Title:
- A study of the accuracy in the methods of sampling, preserving, and testing milk for fat at Oregon milk plants
- Author:
- Robichaux, Roy Paul, 1909-
A study was undertaken to determine, by methods and equipment, the variations between of sampling, preserving, and testing milk for fat during the various seasons of the year, and to try and solve the problem whereby the sampling, preserving, and testing of milk for fat at milk plants could be more uniformly accomplished by different operators. During the period from May 1939 to April 1940 a total of 2064 tests by the Babcock method and 1032 tests by the Mojonnier method were made according to a standardized procedure. A total of 900 daily samples of milk, 12 five day-, 60 seven day-, and 60 fifteen-day composite samples of milk were included in the tests that comprised 10 complete "Units" over the different seasons of the year. Small decreases occurred in the fat percentages of composite samples as compared to the average of daily tests on the same samples of milk. These decreases amounted to 0.016, 0.021, and 0.027 for the five-, seven-, and fifteen-day composites respectively by the Babcock method of testing and 0.023, 0.021, and 0.055 for the three storage periods by the Mojonnier method of testing. The above decreases wore not found to be significant when the data was subjected to a statistical analysis. The Babcock results averaged approximately 0.075 higher in the percentage than the Mojonnier results on the same fresh samples of milk and also on the 5, and 7 day composites. The Babcock results averaged 0.104- higher than the Mojonnier on the 15-day composites. The differences obtained by the Babcock and Mojonnier methods of testing on both daily and composite samples of milk were found to be very significant. Numerous variations from standardized procedure were conducted to determine the effect of such variations on the final fat test. This comparative study included more than 2000 individual tests by the Babcock method and 165 individual determinations by the Mojonnier analysis. Results of these tests showed that: Variations in handling 7, and 15 day composites, such as, storage temperatures of 70° F. or above, not mixing the daily portions properly, and using unsterilized bottles, caused decreases from the average daily tests which amounted to between 0.04 and 0.14. Formalin did not prove to be superior to mercuric chloride as a preservative of milk samples, Saponin did not prevent the decline in the test of composite milk samples. Glymol added to the fat column to remove the upper meniscus in the Babcock test lowered the test by 0.192. The following variations in the Babcock testing technique were found to have a significant effect on the final results obtained: Varying the temperature of the milk above er below normal when measuring the portion for the tests; Using acid of unstandardized strength and incorrect temperature; Varying the temperature of reading the fat column above and below normal; Varying the speed of the centrifuge above or below the specified speed; Using test bottles that varied more than 0.015cc. from the correct capacity of 1.600 cc. in the calibrated portion. The following variations in the Babcock testing technique were found to have slight but noticeable effects on the final fat tests: Not using a proper lighting system to determine the exact position of the upper meniscus in reading the test; Adding water to the tests of such a temperature that the fat column migrated downward at least one inch in tempering at 138° F.; Using speeds of the centrifuge above that which was specified. Results of miscellaneous studies showed that: Duplicate tests by the Mojonnier method checked within an average variation of 0.0064 and a maximum variation of 0.015; Pasteurization of milk prevented the increased difference in results between the Babcock and Mojonnier methods of testing on samples stored for 15- days; Smaller differences were obtained on the same tests by different readers when read by the reading light than were obtained when the light was not used; Errors of 0.05 in reading the Babcock test were attributed to inability to determine the exact position of the top meniscus on the fat column; Dumping the milk in weigh vats at milk plants did not cause enough agitation to incorporate the cream sufficiently to obtain an accurate sample; Closer agreements were obtained with the Babcock and Mojonnier methods on the same sample of milk from Holstein and Ayrshire cows than were obtained on the milk from Jersey cows.
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782. [Article] Biological attributes and alteration of the habitat to manipulate populations of Labops hesperius Uhler (Heteroptera:Miridae)
Biological attributes and alteration of the habitat of Labops hesperius Uhler were investigated on rangeland seeded to crested wheatgrass near Vale, Oregon, and on rangeland seeded to crested and intermediate ...Citation Citation
- Title:
- Biological attributes and alteration of the habitat to manipulate populations of Labops hesperius Uhler (Heteroptera:Miridae)
- Author:
- Fuxa, James R.
Biological attributes and alteration of the habitat of Labops hesperius Uhler were investigated on rangeland seeded to crested wheatgrass near Vale, Oregon, and on rangeland seeded to crested and intermediate wheatgrass near Seneca, Oregon. Nymphs and adults were present at Vale from late March until mid-June and at Seneca from early April until late June or early July. Females at the Vale site preferred to oviposit in dry culms of crested wheatgrass and in Sandberg's bluegrass but they also oviposited in cheatgrass and green calms of crested wheatgrass. Females at a Seneca site oviposited in green intermediate wheatgrass. Population density at the Vale site was positively correlated with the total weight of dry wheatgrass and ground litter present at different locations because the straw provided oviposition sites or protection for the bugs. The obligatory egg diapause was investigated by subjecting eggs collected in September to different temperature treatments in the laboratory. Diapause was terminated after a minimum of 60 days exposure to 3° or 9° C and about two weeks incubation in 15°C and 16-hour photophase. Eggs survived temperatures as low as -15° C, and one temperature treatment resulted in 87% hatch. A 30 day acclimation temperature of 9° or 3° C before exposing the eggs to 3° or -15°C, respectively, resulted in a higher egg-hatch percentage. Egg diapause in L. hesperius differed from that in other mirids because the embryo of the former diapaused at a more advanced stage of embryogenesis. Sticky traps, pitfall traps, and a marking technique were used to study dispersal capabilities of L. hesperius at the Vale site. The bugs were capable of moving 7. 8 meters by walking on the ground and 23. 2 meters by a combination of flying and walking. The bugs could perceive red, yellow, and blue traps, but not white traps, at an altitude of 1. 52 meters, which was the common flight altitude. Macropterous females attained sexual maturity later than brachypterous females indicating that the former are specialized for migration. Males flew but the trap data did not indicate whether the nature of their flight was dispersal or trivial. The low percentage of macropterous females in the population might explain the slow dispersal rate of L. hesperius. Another mirid, Irbisia brachycera Uhler, was also captured in large numbers on sticky traps. Feeding damage to wheatgrass plants was studied by visual evaluation and chemical analysis of the damaged leaves. Chemical analysis indicated that feeding damage caused a decrease in plant cell contents but an increase in digestibility of the cell-wall constituents. However, a damage level of only 25% caused a relative increase in cell-wall constituents to an extent that would probably decrease the voluntary intake of wheatgrass by ruminants. Various range cultural and management practices were investigated to determine whether they could be used to reduce the population density of L. hesperius. Fertilizer treatments that included nitrogen significantly increased the density of L. hesperius but none of the fertilizer treatments significantly decreased the density. The bug density did not increase in proportion to the increase in herbage yield expected from fertilizing wheatgrass with nitrogen. The herbicide Paraquat indirectly killed nymphs and adults of L. hesperius by prematurely curing the wheatgrass which resulted in starvation of the bugs. The egg density was also reduced because the females starved to death before they were able to oviposit. Paraquat reduced the herbage yield as expected but increased the quality of the herbage. Prematurely curing wheatgrass with Paraquat will be an economical method of controlling L. hesperius provided that the spray can be timed to both reduce the bug population and increase the feed value of the forage. Mechanical removal of herbage during the egg stage reduced the bug population density by directly destroying the eggs or by exposing them to more harsh winter conditions or both. Mechanical removal during the nymphal and adult stages did not directly affect the population density since the bugs were able to find sufficient food for survival in the stubble. However, mechanical removal of herbage during the nymphal stages can reduce bug density in populations that are relatively dense originally, and removal immediately before oviposition prevents the females from laying eggs. Field burning, hay crop removal, and grazing are cultural practices that might control L. hesperius by mechanically removing the herbage. Hay crop removal, grazing during the nymphal and early adult stages, and grazing during the egg stage should each prove useful for controlling L. hesperius on different types of pasture infested with bugs.
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783. [Article] Characterization of microaggregate formation by Mycobacterium avium subspecies hominissuis
Mycobacterium avium subsp hominissuis (MAH) is an opportunistic environmental pathogen that causes respiratory and gastrointestinal illness in immunocompromised persons such as those with chronic respiratory ...Citation Citation
- Title:
- Characterization of microaggregate formation by Mycobacterium avium subspecies hominissuis
- Author:
- Babrak, Lmar
Mycobacterium avium subsp hominissuis (MAH) is an opportunistic environmental pathogen that causes respiratory and gastrointestinal illness in immunocompromised persons such as those with chronic respiratory diseases or AIDs, respectively. In recent years, there has been a significant increase in the incidence of nontuberculous mycobacterial (NTM) lung infections, including in cystic fibrosis patients where MAH accounts for 72% of mycobacterial infections. Currently, there is no efficient approach to prevent or treat MAH infection in the lungs. During initial colonization of the airways, MAH form microaggregates composed of 3 to 20 bacteria on the human respiratory epithelial cells, which provides an environment for phenotypic changes leading to efficient mucosal invasion in vitro and in vivo. In this dissertation, the aims are to identify and characterize genes that are important for the invasive microaggregate phenotype and characterize the host response to microaggregate infection to further understand the early stages of MAH respiratory infection. In Chapter 2, DNA microarray analysis was employed to identify genes associated with the microaggregate phenotype. The gene encoding microaggregate- binding protein 1 (MBP-1) (MAV_3013) is highly expressed during microaggregate formation. When expressed in noninvasive Mycobacterium smegmatis, MBP-1 increased the ability of the bacteria to bind to HEp-2 epithelial cells. Using anti-MBP- 1 immune serum, microaggregate binding to HEp-2 cells was significantly reduced. By far-Western blotting, and verified by coimmunoprecipitation, we observed that MBP-1 interacts with the host cytoskeletal protein vimentin. As visualized by confocal microscopy, microaggregates, as well as MBP-1, induced vimentin polymerization at the site of bacterium-host cell contact. Binding of microaggregates to HEp-2 cells was inhibited by treatment with an anti-vimentin antibody, suggesting that MBP-1 expression is important for M. avium subsp. hominissuis adherence to the host cell. MBP-1 immune serum significantly inhibited M. avium subsp. hominissuis infection throughout the respiratory tracts of mice. In Chapter 3, the small hypothetical gene MAV_0831 (Microaggregate Invasion Protein-1, MIP-1) was identified as being upregulated during microaggregate formation. When MIP-1 was overexpressed in poorly-invasive M. smegmatis, it provided the bacterium the ability to bind and enter epithelial cells. In addition, incubating microaggregates with recombinant MIP-1 protein enhanced the ability of microaggregates to invade HEp-2 cells, and exposure to anti-MIP-1 immune serum reduced the invasion of the host epithelium. Through protein-protein interaction assays, MIP-1 was found to bind to the host protein filamin A, a cytoskeletal actin-binding protein integral to the modulation of host cell shape and migration. As visualized by immunofluorescence, filamin A was able to co-localize with microaggregates and to a lesser extent planktonic bacteria. Invasion of HEp-2 cells by microaggregates and planktonic bacteria was also inhibited by the addition of anti-filamin A antibody suggesting that filamin A plays an important role during infection. In addition, at earlier time points binding and invasion assay results suggest that MBP-1 participates significantly during the first interactions with the host cell while MIP-1 becomes important once the bacteria adhere to the host epithelium. While these studies are valuable in understanding the pathogenesis of MAH, they primarily investigated the bacteria during microaggregate infection without commenting on the differences in the host response to microaggregate and planktonic infection. In Chapter 4, the bacteria-host interaction between microaggregates and epithelial cells was examined in a variety of assays. Using a transwell polarized epithelial cell model, microaggregates tended to translocate through the monolayer more efficiently than planktonic bacteria. In addition, during infection with microaggregate and planktonic bacteria, host phosphorylated proteins were identified revealing differences in immune response, glutathione synthesis, and apoptosis. The host immune response was further investigated by measuring pro-inflammatory cytokine secretion during microaggregate and planktonic infection of BEAS-2B bronchial epithelial cells. The epithelial cells secreted more CCL5 during microaggregate infection suggesting that this chemokine may play an important role during microaggregate invasion. Collectively, this study confirms the different nature of infection by planktonic bacteria and microaggregates. Overall, our data provide insights into the initial interaction between MAH and the respiratory mucosa. We characterized a pathogenic mechanism of infection utilized by MAH to manipulate the host respiratory epithelium and suggest new potential targets for the development of anti-virulence therapy.
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The carboxylesterases of three species of diptera, the flesh fly (Sarcophaga bullata, Park.), the black blow fly (Phormia regina, Meig.), and the house fly (Musca domestica, L.) were compared in relation to ...
Citation Citation
- Title:
- Carboxylesterases in the house fly (Musca domestica, L.), flesh fly (Sarcophaga bullata, Park.), and black blow fly (Phormia regina, Meig.)
- Author:
- Maa, Can-jen William
The carboxylesterases of three species of diptera, the flesh fly (Sarcophaga bullata, Park.), the black blow fly (Phormia regina, Meig.), and the house fly (Musca domestica, L.) were compared in relation to hydrolytic activity against three substrates, response to inhibition and induction, isozyme composition, and age-dependent variation in activity. Similar studies were also conducted with an insecticide-resistant house fly strain. Most of the experiments were with adult female flies but male flies as well as larvae and pupae were included in several experiments. Naphthyl acetate was the substrate common to all experiments and the esterases hydrolyzing this compound were further characterized according to their inhibition by eserine, parahydroxymecuribenzoate (PHNB), and paraoxon. The hydrolytic activity observed in the presence of eserine and PHNB or blocked by paraoxon was considered to be due to carboxylesterases of the B-type. Two other esters, hydroprene, an insect growth regulator similar in structure to the natural juvenile hormone, and juvenile hormone-1, were also used as substrates. Neither the hemolymph nor the cytosol esterases of the three species were susceptible to eserine inhibition, indicating that the samples contained minor quantities of the choline esterases. PHNB had little inhibitory effect on the flesh fly esterases of both hemolymph and soluble fraction. However, this inhibitor reduced the activity of the blow fly esterases by more than 50 percent, indicating a high content of aryl esterases in this species. The house fly esterases were also inhibited by PHNB but to a less extent than those of the blow fly. As expected, paraoxon was a strong inhibitor of the esterases in both hemolymph and soluble fraction of the three species. The total enzyme content of the flies was estimated from the hemolymph volumes determined earlier and the activity per unit volume found in the age-dependency experiments. The daily average activity estimated in this way was highest in the flesh fly, about four times that of the blow fly, and lowest in the house fly, about one-seventh that of the flesh fly. The values were even lower in the case of the resistant house flies, about 1/40th those of the flesh fly. When hydroprene was used as a substrate in the age-dependency experiments, the activity profiles were similar to those found with naphthyl acetate as substrate indicating that the same enzymes were involved in the hydrolysis of this JH analogue. Of the three species, the flesh fly esterases were most active against hydroprene and the blow fly and resistant house fly enzymes were the least active. The flesh fly hemolymph enzymes averaged, on a per-day basis, up to three times more hydroprene cleaving activity than those of the resistant house flies. The electrophorese experiments with hemolymph and cytosol revealed the presence of several carboxylesterase isozymes. As many as 14 different esterase-active bands were found in flesh fly hemolymph, 11 in blow fly hemolymph, and 12 in house fly hemolymph. Similar results were obtained with the cytosol. These bands were placed in five groups according to their mobilities in the poly acrylamide gels and it was evident that the isozymes migrating to the midpoint of the gels were responsible for most of the carboxylesterase activity. Some slow-moving isozymes were also thought to be responsible for this type of activity. Other evidence obtained during the electrophoreses experiments indicated that the isozymes hydrolizing hydroprene were from the same groups as those cleaving naphthyl-acetate while those which attacked JH-1 had different electrophoretic characteristics. Both hydroprene and naphthyl acetate esterases were induced by topically applied hydroprene. The response was dose dependent in the range 1-10 ug for flesh flies and 1-5 ug for house flies and blow flies. However, the response was variable and appeared to depend on the age of the flies at the time of the treatment. Increases in esterase activity ranged from 1.5 to 4-fold with the flesh fly enzymes being the most responsive and those of the blow fly the least. The possibility of JH-1 esterase induction by hydroprene was not investigated.
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785. [Article] Transcription factor CTIP2 regulates hair follicle development, hair cycling and wound healing
The integumentary system is the largest organ system of the body that comprises of skin and its appendages such as hair follicles, sebaceous and sweat glands. Skin is divided into three distinct structural ...Citation Citation
- Title:
- Transcription factor CTIP2 regulates hair follicle development, hair cycling and wound healing
- Author:
- Bhattacharya, Shreya
The integumentary system is the largest organ system of the body that comprises of skin and its appendages such as hair follicles, sebaceous and sweat glands. Skin is divided into three distinct structural layers: the epidermis, dermis and hypodermis. The epidermis originates from the ectoderm and is composed of four layers specified as basal, spinous, granular and corneal layer. The function of epidermis is to protect against all sources of environmental insults, prevent water loss and undergo re-epithelialization after wounding. For its normal functioning, the epidermis continually replenishes itself through a process of continuous proliferation and terminal differentiation of keratinocytes from the basal layer. The hair follicle is a complex appendage of skin, which give rise to the keratinized hair shaft. Hair follicle is formed during embryonic development and it goes through cycles of growth (anagen), regression (catagen) and quiescence (telogen). The bulge region of the hair follicle in the outer root sheath area contains slow-cycling stem cells which are responsible for normal hair cycling as well as cutaneous wound repair after injury. CTIP2 (COUP-TF interacting protein 2) is a C2H2 zinc finger transcription factor that is expressed in various organs and tissues. It has been shown to play an important role in the development of thymocyte, tooth and corticospinal motor neuron. Expression of CTIP2 is observed in the developing murine epidermis and dermis during skin organogenesis and predominantly in epidermal keratinocytes in adult mice skin. It is also expressed in the embryonic and mature adult hair follicles, especially in bulge region. CTIP2 regulates epidermal proliferation and terminal differentiation during embryogenesis and adulthood. Here we show that CTIP2 controls hair follicle development, hair cycling and cutaneous wound healing. To study the role of CTIP2 in hair morphogenesis and hair cycling, we have utilized two different genetically modified mouse strains. First, we studied the effect of CTIP2 during hair follicle formation using Ctip2-null mice containing a germline deletion of Ctip2. Ctip2-null mice exhibited reduced hair follicle density and downregulation of EGFR and NOTCH1 expression. To analyze the consequence of loss-of–funtion of CTIP2 on postnatal hair cycling, we selectively ablated Ctip2 in the epidermis and hair follicles using the Cre-LoxP strategy to generate Ctip2[superscript ep-/-] mice. Ctip2[superscript ep-/-] mice showed a defect in postnatal hair cycling marked by early exit from telogen and premature entry into anagen. The premature induction of anagen is a result of stem cell activation, increase in cell proliferation and decrease in apoptosis-driven cell death in the hair follicles. This early activation of follicular stem cells eventually leads to their depletion and therefore ultimate loss of hair follicles and hair coat. Reduced expression of LHX2 and NFATC1, which are two important regulators of hair cycling, was observed in the bulge area of Ctip2[superscript ep-/-] mice hair follicles. Furthermore, chromatin immunoprecipitation (ChIP) assay revealed that CTIP2 is recruited to the promoter region of both Lhx2 and Nfatc1 and possibly directly regulates their expression. Altogether, our results suggest that CTIP2 modulates expression of factors that regulate hair follicle morphogenesis and normal hair cycling as well as control stem cell fate and survival in the HFs. Considering CTIP2’s role in skin formation and homeostasis we hypothesized that CTIP2 is involved in the epidermal regeneration process during wound closure after injury. To test our hypothesis, we used Ctip2[superscript ep-/-] mouse model where Ctip2 is conditionally inactivated in epidermis and hair follicle. Selective ablation of Ctip2 in the epidermis and HFs lead to the delay in wound healing. The slower healing property was an outcome of impaired keratinocyte activation, proliferation, differentiation and migration. Moreover, defects in cell-cell adhesion and ECM development were also observed in the healing wounds of Ctip2ep-/- mice due to the lack of E-cadherin and insufficient expression of alpha smooth muscle actin. Hair follicle stem cell factors such as K15, CD34, CD133, NFATC1 and LRIG1 that are crucial for wound re-epithelialization were aberrantly expressed in wound adjacent region of Ctip2[superscript ep-/-] mice. Our results identify CTIP2 as a key regulator of epidermal stem cells during skin wound healing and an important player in efficient wound closure after injury.
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Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental ...
Citation Citation
- Title:
- Chemical element profiles by instrumental neutron activation analysis : in, part 1, two species of wheat bunt spores, Tilletia caries (DC) Tul. and Tilletia controversa Kühn; part 2, representative sediment and basalt samples taken from a DSDP 678 m core, site 525A, Leg 74, Walvis Ridge
- Author:
- Liu, Yun-gang
Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental neutron activation analysis in 37 TS spore samples, and 31 DS spore samples. Aluminum was chosen as a soil contamination indicator to correct for soil contamination. The plot of the concentrations of the ith element [X[subscript i]] versus Al, yielded the biological concentrations of [X.[subscript i]]. The results show that the biological concentrations of Sc, V, La, and Sm are insignificantly small and that their contents in the spores are essentially all derived from soil dust contamination. For Na and Fe, considerable fractions, 0.15 and 0.60, respectively, of their total concentrations are derived from soil contamination. For other elements, the soil contamination contributions are relatively small compared to their biological concentrations. The "student" t-test was used for comparisons of the geometric means of the element concentrations between the TS and DS spore series. The differences between the mean values of Cl, K, Ca, Mn, Zn, and Br for the TS and CS series are not totally due to random errors within the 95% confidence level. The differences for K and Cl between the TS and DS series are large and outside the ±10- limits; therefore, the concentrations of these two elements can be used as reliable criteria for distinguishing these two species. Also, Br may be useful as a diagnostic trace element due to the significant difference between the Br geometric means of the TS and DS spores. Part 2 Forty sediment and four basement basalt samples, taken from a 678 m core drilled by the DSDP (Deep Sea Drilling Project) at Site 525A, Leg 74 (June 10-15, 1980), as well as sixteen selected basalt samples around the south Atlantic Ocean were subjected to instrumental neutron activation analysis. Thirty-two major, minor, and trace elements were determined. The core from the Wavlis Ridge site (2467 m) consisted of 574.6 m of sediment and 103.5 m of basalt. The downcore element concentration profiles and regression analyses show that the rare earth elements (REE) are present in significant amounts in both the carbonate and non-carbonate phases in sediments; Sr is concentrated in the carbonate phase; most of the other elements determined exist mainly in the non-carbonate (mostly clay) phase. The calculated partition coefficients of the REEs between the carbonate phase and the free REE ion concentrations in sea water were high and increased with decreasing REE ionic radii or increasing atomic number from 3.9x10⁶ for La to 15x10⁶ for Lu. Using the partition coefficients of the REEs in the carbonate and non-carbonate (clay) phases, the REE concentrations in Atlantic sea water were calculated, and the results indicate that the lanthanide concentrations have not been changed significantly in south Atlantic sea water over the past 70 m.y.. The Ce anomaly observed in >95% carbonate sediments is related to the Ce⁺³ concentration in sea water; therefore, the Ce anomaly is a redox (reducing-oxidizing) indicator of sea water. (Essentially, >99.99% of soluble Ce in sea water is present as Ce⁺³.) The REE patterns show no Ce depletion in mollusc shell segments from the late Campanian, and a slight Ce depletion in carbonate phases from the late Paleocene sediments. From early Eocene on, the REE patterns in the carbonate phase show a marked Ce depletion, the same as is observed in carbonates from the late Pleistocene to early Holocene (about 0.3 m.y. ago). The abrupt and striking change in the Ce depletion indicates that sea water was anoxic over the Walvis Ridge during the late Campanian. As the gap between northeast South America (northeast Brazil) and west central Africa (near the southwest corner of the upper half of Africa, e.g., near Liberia) widened and the Walvis Ridge subsided between the late Campanian and late Paleocene, sea water flow between the north Atlantic and south Atlantic oceans increased steadily, and gradually flushed out the anoxic water layer over the Walvis Ridge, thereby achieving oxidation conditions at about 54 m.y. ago, that are similar to present day sea water redox conditions: in the world oceans. The chemical compositions of the basement rocks of the core corresponds to alkalic basalts, not MA-Crean Ridge basalts (MORBs). Only a few basement rocks had been recovered from other Walvis Ridge sites. The results add more evidence which supports the hypothesis that the Wavlis Ridge was formed by a series of volcanoes moving over a "hot spot" near the Mid-Atlantic Ridge. These volcanoes migrated eastward as the South American and African continents drifted away. Most of the basalt samples taken from the southeast Brazilian continental margin also are not similar to MORE. From the bulk chemical composition and the REE pattern, one 112 m.y. old basalt has been identified as an early-stage MORB. To date, this is the oldest oceanic tholeiite recovered from the south Atlantic. This direct evidence indicates that the continental split between South America and Africa commenced ≥112 m.y. ago, and is consistent with the suggestion that the rift between the two continents began about 125 m.y. ago.
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787. [Article] Potential effects of climate change and fire management on fire behavior and vegetation patterns on an east Cascades landscape
Climate exerts considerable control on wildfire regimes, and climate and wildfire are both major drivers of forest growth and succession in interior Northwest forests. Estimating potential response of ...Citation Citation
- Title:
- Potential effects of climate change and fire management on fire behavior and vegetation patterns on an east Cascades landscape
- Author:
- Greaves, Heather E.
Climate exerts considerable control on wildfire regimes, and climate and wildfire are both major drivers of forest growth and succession in interior Northwest forests. Estimating potential response of these landscapes to anticipated changes in climate helps researchers and land managers understand and mitigate impacts of climate change on important ecological and economic resources. Spatially explicit, mechanistic computer simulation models are powerful tools that permit researchers to incorporate climate and disturbance events along with vegetation physiology and phenology to explore complex potential effects of climate change over wide spatial and temporal scales. In this thesis, I used the simulation model FireBGCv2 to characterize potential response of fire, vegetation, and landscape dynamics to a range of possible future climate and fire management scenarios. The simulation landscape (~43,000 hectares) is part of Deschutes National Forest, which is located at the interface of maritime and continental climates and is known for its beauty and ecological diversity. Simulation scenarios included all combinations of +0°C, +3°C, and +6°C of warming; +10%, ±0%, and -10% historical precipitation; and 10% and 90% fire suppression, and were run for 500 years. To characterize fire dynamics, I investigated how mean fire frequency, intensity, and fuel loadings changed over time in all scenarios, and how fire and tree mortality interacted over time. To explore vegetation and landscape dynamics, I described the distribution and spatial arrangement of vegetation types and forest successional stages on the landscape, and used a nonmetric multidimensional scaling (NMS) ordination to holistically evaluate overall similarity of composition, structure, and landscape pattern among all simulation scenarios over time. Changes in precipitation had little effect on fire characteristics or vegetation and landscape characteristics, indicating that simulated precipitation changes were not sufficient to significantly affect vegetation moisture stress or fire behavior on this landscape. Current heavy fuel loads controlled early fire dynamics, with high mean fire intensities occurring early in all simulations. Increases in fire frequency accompanied all temperature increases, leading to decreasing fuel loads and fire intensities over time in warming scenarios. With no increase in temperature or in fire frequency, high fire intensities and heavier fuel loads were sustained. Over time, more fire associated with warming or less fire suppression increased the percentage of the landscape occupied by non-forest and fire-sensitive early seral forest successional stages, which tended to increase the percentage of fire area burning at high severity (in terms of tree mortality). This fire-vegetation relationship may reflect a return to a more historical range of conditions on this landscape. Higher temperatures and fire frequency led to significant spatial migration of forest types across the landscape, with communities at the highest and lowest elevations particularly affected. Warming led to an upslope shift of warm mixed conifer and ponderosa pine (Pinus ponderosa) forests, severely contracting (under 3° of warming) or eliminating (under 6° of warming) area dominated by mountain hemlock (Tsuga mertensiana) and cool, wet conifer forest in the high western portion of the landscape. In lower elevations, warming and fire together contributed to significant expansion of open (<10% tree canopy cover) forest and grass- and shrubland. The compositional changes and spatial shifts simulated in the warming scenarios suggest that climate change is likely to significantly affect forests on this landscape. Warming and associated fire also tended to increase heterogeneity of forest structural stages and landscape pattern, resulting in a more diverse distribution of structural stages, especially in lower elevations, and a more divided landscape of smaller forest stands. The NMS ordination emphasized the dissimilarity between the severe +6° scenarios and the other two temperature scenarios. The +0° and +3° scenarios differed from each other in composition (mainly because cool forest was lost in the +3° scenarios), but within a given level of fire suppression they remained remarkably similar in terms of overall composition, structure, and landscape pattern, while the +6° scenarios separated noticeably from them. Such decisive differences suggest that under the simulated ranges of precipitation and fire suppression, the interval between 3 and 6 degrees of warming on this landscape may capture an ecological threshold, or tipping point. Additional simulation research that incorporates (for example) management actions, insects and pathogens, and a wider array of precipitation scenarios could help illuminate more clearly the possible range of future landscape conditions. Still, these results provide a glimpse of potential divergent outcomes on this important landscape under possible future climates, and suggest that these forests will undergo considerable changes from both historical and current conditions in response to higher temperatures expected in this area. Some changes may be inevitable with warming, such as the upslope shift of warm forest types, but careful planning for fire and fuels management might allow land managers to modulate fire behavior and steer vegetation dynamics toward the most desirable outcome possible.
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Evaluations of previously established field trials indicate that chioropicrin and Vorlex continue to provide a diminishing level of protection to Douglas-fir poles. Tests of solid methylisothiocyanate ...
Citation Citation
- Title:
- Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1991
- Author:
- Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.)
Evaluations of previously established field trials indicate that chioropicrin and Vorlex continue to provide a diminishing level of protection to Douglas-fir poles. Tests of solid methylisothiocyanate (MITC), now in their thirteenth year, indicate that this chemical continues to prevent recolonization of Douglas-fir poles by decay fungi. MITC appears to provide equivalent or better protection than Vorlex. Gelatin encapsulated MITC and chioropicrin also continue to perform well in field trials. Although the gelatin is water soluble and must decompose to release the chemical, the addition of water to the treatment holes did not appear to significantly enhance long-term MITC performance. Laboratory trials to identify safer fumigants indicate that sodium nmethyldithiocarbamate decomposition occurs even in dry wood, although the rate of decomposition is enhanced by the presence of some moisture. A gelled 40 % NaMDC formulation has also been evaluated for its ability to eliminate decay fungi from Douglas-fir heartwood. This formulation has performed better than liquid metham sodium. Field trials are planned with both the solid and gelled NaMDC. Laboratory trials have also been performed to evaluate the toxicity of fused borate rods to Antrodia carbonica and Postia placenta. These two fungi are important decayers of Douglas-fir utility poles. The results indicate that the boron moved well through both wood species, but complete elimination of the test fungus required 6 to 8 weeks. Antrodia carbonica was generally more tolerant of boron than P. placenta. Field trials of fused borate rods indicate that the boron has moved downward from the point of application, but no evidence of upward movement was noted. Trials to evaluate the efficacy of glass-encapsulated M:[TC in Douglas-fir 1 11 and southern pine poles are now in their second year. The results continue to indicate the MITC levels are higher in Douglas-fir poles. The reasons for this descrepancy are unclear, but may reflect an increased MITC loss from the more permeable southern pine poles. Controlled studies of MITC release rates from the glass vials show that the tubes retain chemical for 1 to 2 years under normal conditions. Faster losses occur under more tropical conditions, while little loss occurs in cold conditions. Evaluations of additives to enhance Basamid decomposition in Douglas-fir pole sections indicate that the presence of copper sulfate and pH 12 buffer markedly improve the rate of decomposition to MuG one year after chemical application. More controlled laboratory studies are underway to better understand this effect. The trials to evaluate the effects of voids on fumigant movement continue to indicate that the void has little effect on chemical concentration. These results indicate that fumigant treatment of poles with voids is feasible provided the wood retains adequate strength. Laboratory trials to develop diffusion coefficients for chloropicri.n movement through Douglas-fir heartwood have been developed. As expected, chioropicrin movement was most rapid longitudinally and at the fiber saturation point. Drier wood retained more chemical, slowing diffusion. The diffusion coefficients will be employed in the fumigant model currently being evaluated on MITC. The model indicates that MITC movement was greatest at moderate moisture levels (22 or 44 %), while higher or lower moisture regimes limited chemical movement. The results obtained using the model will be confirmed through laboratory trials and by comparison with the results of chemical analyses performed on the glass-encapsulated MITC trials. The trials to identify potential replacements for pentachlorophenol for Ii' remedial treatments are continuing. A number of chemicals have been identified for both the protection of field drilled bolt holes and the spray treatment of western redcedar sapwood. Spray treatments of the most promising chemicals will be applied to western redcedar poles in service. The identification of small scale tests for detecting decay or estimating residual strength are continuing. We also continue to evaluate the effectiveness of various pretreatments for improving treatment and performance of poles. The effects of through boring and radial drilling patterns on treatment were evaluated on a glue-laminated Douglas-fir pole. While some differences were noted in the patterns, the pole was too well-treated to permit effective separation of the various patterns. The air-seasoning studies are now completed. Evaluation of the final pahse of this study showed that decay fungi began to colonize the pole sections after only 3 months of air-seasoning. Examination of weather data failed to provide a conclusive relationship between climate and colonization, possibly due to the array of variables to which the seasoning wood is subjected. The test suggests that most poles are adequately dried within three months of air-seasoning so that short air-seasoning exposures could be feasible. Sterilization at some point during the treatment cycle should still be considered as an integral part in the proper treatment of poles. Field trials to evaluate the performance of modified groundline wrap systems are continuing at both the Corvallis site and on a test line near Modesto, CA. The results at the Corvallis site indicate the copper naphthenate, boron, and fluoride are all moving well into the wood eighteen months after application. More controlled laboratory trials on one formulation suggest that the water soluble copper naphthenate can migrate for some distance into the wood within six months after application. As expected, wet wood permits more iv substantial diffusion. Evaluation of copper naphthenate treated western redcedar stakes in a fungus cellar suggests that the specified treatment levels are providing adequate protection, although some decay is occurring. Stakes which were obtained from weathered sapwood appear to be failing more rapidly those cut from freshly sawn lumber, possibly because the former stakes have a more open structure which permits leaching losses and subsequent fungal colonization.
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This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues ...
Citation Citation
- Title:
- Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1987
- Author:
- Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.)
This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues to protect Douglas-fir poles after 17 years and piling after 12 years. Vorlex treated poles are being gradually recolonized by decay fungi, while the Vapam treated poles appear to have little resistance to decay fungi. The latter poles were retreated last summer and will be used to determine the effectiveness of fumigant retreatment. Solid methylisothiocyanate (NIT) continues to protect Douglasfir poles, although the 20 percent NIT treatment has experienced slightly higher levels of colonization after 9 years. Additional tests to evaluate the effectiveness of gelatin encapsulated MIT or chioropicrin indicate that both chemicals continue to remain effective. In addition, there now appears to be little difference between the levels of control exhibited following addition of varying amounts of water to the poles along with gelatin encapsulated NIT. Closed tube bioassays indicate the chioropicrin remains at fungitoxic levels after 17 years, while no volatile fungitoxins appear to be present in Vapam or Vorlex treated wood. The evaluation of untreated Douglas-fir posts treated with NIT, chloropicrin, or Vapam indicate that fumigants can not ccatletely protect untreated wood in ground contact unless there is sane other type of preservative treated barrier present. Although the NIT treatment provided the best protection, all of the posts experienced some surface decay and termite attack after 10 years. These results appear similar to those found with more recent tests of posts treated with various coLthinations of preservative containing wraps and fuinigants. Evaluation of Mylone and tridipain, two solid chemicals that degrade to produce NIT, initcates that NIT production and fungal control are enhanced by the addition of basic pH buffers; however, only the pH 12 buffer resulted in rapid fungal control. These results Jnitcate that the rate of fumigant release can be tailored to control specific decay problems. We have also investigated the decomposition of Vapam in wood. As previously reported, there are over 14 potential deccmposition products from this chemical. This past year we developed methods for assaying these chemicals, evaluated the long-term stability of each, and prepared test blocks for evaluating decc*,osjtion in wood. In addition, we have studied the migration of volatile compounds from Vapam and NIT treated blocks under controlled aeration. After 5,000 hours, detectable levesis of NIT, carbon disulfide, and carbon oxysulfide are still present in air surrounding the Douglas-fir blocks. These tests indicate that low levels of volatile chemicals are continuously eninitted from fumigant treated wood. While this poses little difficulty for utility poles, it may pose some hazard for wood in closed spaces. Evaluations will continue until the emission levels decline below detectable limits. In addition to Vapam deccmposition studies, we have also evaluated the decoxrosition, movement and fungitoxicity of NIT under a variety of environmental conditions. In general, wet wood held less NIT, but the degree of control produced was more rapid. These results suggest that dry wood will act as a reseivoir of NIT, which will be released as moisture enters and swells the wood. This effect may provide an excellent long-term decay control strategy. The information from these studies will be used to develop more 111 ecific recaimrndations for fumigant treatment. Cedar Saood Decay Control: This past year we reestablished the field test of promising nei pentachiorophenol replacements, incorporating 26 chemicals into these tests. These saitles will be evaluated after 1 and 2 years to determine efficacy. In addition to the field test, we evaluated 13 new formulations or cinations of formulations in our laboratory screening tests. A nuner of chemicals including Isothiazolone, Amical 48 and a nurrer of quaternary aimnonium compounds appear promising and have been included in the field test. Bolt Hole Decay Prevention: Test established 5 years ago to determine the effectiveness of sprays, liquids or pastes applied to field drilled bolts holes indicate that airanonium bifluoride, Boracol 40, and 10% penta provided greater protection than Polybor or Patox washers. In addition, no evidence of corrosion was associated with any of the treatments. Fumigant treatments below the bolt holes continue to eliminate decay fungi, although samples removed from further down the pole indicate an incoIr)1ete distribution of MIT. These tests will be reevaluated this coming year. Detecting Early Decay and Estimating Residual Strength: We continue to evaluate the use of fluorescent coupled lectins and infra-red spectroscopy for detecting fungi in wood and early decay under controlled laboratory conditions. We have also continued evaluation of longitudinal compression (L) as a measure of ultite wood strength using a series of 27 Ldgepole pine posts. While the dense knot clusters interferred with the analysis, LCS, in combination with other parameters, was a reasonably good predictor of bending strength. These tests will continue with more uniform material. iv In addition to tests of LCS, we have evaluated the ability of small scal e tests to determine the strength of various wood pole connectors. Out results were in close agreement with those obtained using full scale tests aii illustrate the value of using small r1 e tests to develop strength information. Initiation of Decay in Air-Seasoning Douglas-fir: We continue to evaluate the data developed in the air-seasoning st1wies. This past year we began to develop information on the effects of various colony sizes on wood strength. This data will help us assign strength values to the colony size data we ha developed frau the air-seasoning study. At present, only Peniophora spp. has been tested, but . carbonica, P. placenta, and Haematostereum sanguinolentuin will also be included. Evaluation of the teinperatures required to eliminate fungi from Douglas-f ir poles also continue. We have ccatpleted 9 test charges which indicate that the penta treatmants involving a Boulton-seasoning cycle result in a ixre than adequate heating of the wood, while steam treants associated with amnniacal copper arsenate are nre variable. We feel that longer heating periods are required for poles greater than 12 inches in diamater, but that the current 6 hour steam period will result in heating of the center to 67 C for over 1 hour in smaller poles. Microfungi in Douglas-fir Poles: We continue to evaluate the effects of nticrofungi on properties of fumigant treated Douglas-fir poles. These tests indicate that prior colonization of fumigant treated wood by Scytalidium or Trichoderma species resulted in lower weight losses by P. placenta and . carbonica. Evaluation of a Cellon treated Douglas-fir laminated beam indicated that V severe penta depletion was associated with virtually all of the surface decay present. This beam had only been in service for 12 years in an extremely dry climate arxl it is unclear why the decay was so rapid.
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790. [Article] Surface-subsurface geology of the middle to upper Eocene sedimentary and volcanic rock units, western Columbia County, northwest Oregon
The middle to upper Eocene Tillamook Volcanics form the basement in the Rock Creek - Rocky Point area. These tholeiitic to alkalic basalts, basaltic andesites, and andesites were erupted as shield volcanoes ...Citation Citation
- Title:
- Surface-subsurface geology of the middle to upper Eocene sedimentary and volcanic rock units, western Columbia County, northwest Oregon
- Author:
- Berkman, Thomas Anthony
The middle to upper Eocene Tillamook Volcanics form the basement in the Rock Creek - Rocky Point area. These tholeiitic to alkalic basalts, basaltic andesites, and andesites were erupted as shield volcanoes seaward of the strandline ontop of an older deep-marine mudstone unit (Yamhill Formation) and an accreted portion of oceanic seafloor (lower Eocene Siletz River Volcanics). The subaerial flows are predominantly aphyric with subordinate plagioclase-augite porphyritic flows with pilotaxitic texture. The overlying Hamlet formation (informal) is composed of three members which document a marine transgression over subsiding islands of Tilamook Volcanics in the middle to late Eocene. The stratigraphically lowest Roy Creek member is composed of basaltic boulder to cobble conglomerate grading upward into fossiliferous pebbly basaltic sandstone deposited around sea stacks and along a high-energy rocky coastline composed of Tillamook Volcanics. Continued subsidence and transgression resulted in deposition of the Sunset Highway member of the Hamlet formation, which conformably overlies the Roy Creek member. The Sunset Highway member consists of interbedded micaceous arkosic sandstone and siltstone with rare basaltic grit beds occurring near the top of the member. Molluscan fauna, faint low-angle cross-bedding, parallel laminations and bioturbation in these sandstones are interpreted to represent deposition in a high-energy inner shelf environment. The upper Narizian (upper Eocene) Sweet Home Creek member conformably overlies the Sunset Highway member in western Columbia and eastern Clatsop counties and is composed of two lithofacies. The dominant lower facies consists of micromicaceous and carbonaceous silty mudstone which contains abundant Foraniinifera indicative of outer neritic to tipper bathyal water depths. Thin-bedded micaceous arkosic turbidite sandstones in nested channels of the upper facies are locally present near the top of the unit and represent deposits of a channelized shelf-slope break. Abrupt sea level regression coupled with increased sedimentation rates due to tectonic unroofing in source areas in Idaho and Washington resulted in abrupt shallowing of sedimentation before deposition of the overlying Cowlitz Formation (C & W sandstone member). The C & W sandstone in cores from the Mist Gas Field and outcrops in the Rock Creek - Rocky Point area in Columbia County consists of massive to hummocky bedded sandstone with some bioturbated siltstone and coal formed in a delta front complex ranging from brackish-water swamps to storm-wave-dominated lower shoreface environments. Sandstone onlaps basement highs of Tillamook Volcanics (Nehalem arch), resulting in a complicated facies geometry with some intrabasinal basaltic detritus. Sedimentary structures, statistical grain size analysis, and lithofacies associations suggest that strong wave processes reworked the delta front sands during a transgression at the seaward edge of the system. Thickening-upward and shallowing-upward sequences record periods of westward deltaic progradation and increasing storm-wave energy. C & W gas reservoirs consist of well-sorted, friable, fine-grained arkose to lithic arkose. Sandstone reservoir porosity and permeability average 31% and 1200 md, respectively. Porosity is dominated by primary intergranular pores which have been reduced by (1) compaction of ductile grains, (2) formation of minor mixed-layer clay rim cement, sparry calcite cement and authigenic pyrite, and (3) late stage precipitation of plagioclase, K-feldspar, and quartz overgrowths. However, partial dissolution of plagiociase feldspar has created some secondary porosity. Although arkosic sandstones have high porosities and correspondingly high permeabilities, chioritic cement in volcaniclastic-rich sandstones significantly reduces permeability without concomitant reduction in porosity. The Cole Mountain basalt (informal) locally intnides and overlies the Cowlitz Formation. These basalts to basaltic andesites have calc-alkaline affinities and consist of hypabyssal sills, submarine lava flows, and local peperites which are lithologically, chemically, and petrographically distinct from the slightly older Tillamook Volcanics. The uppermost Narizian to Refugian (latest Eocene) Keasey Formation unconfonnably overlies the Cowlitz Formation in the study area. Volcanic and glauconitic sandstones at the base of the Keasey Formation mark the unconformity and reflect a period of slow sedimentation under slightly reducing conditions. The Keasey Formation predominantly consists of stractureless, tuffaceous fossiliferous mudstone deposited by hemipelagic sedimentation on the middle to upper slope. The informal Miocene (?) Ivy Creek formation locally disconformably overlies the Keasey Formation in the study area. The fluvially deposited Ivy Creek formation consists of a friable upper trough cross-bedded pebbly sand fades which overlies 9 m of blue organic-rich overbank clay. Local pebbly grits in matrix-support with buried flow-oriented rooted tree stems suggest that some debris flows entered the fluvial system from surrounding highlands. The unit may correspond to the middle Miocene Scappoose Formation. Northwest-trending down-to-the-northeast high-angle faults, some with oblique offset, and a subordinate set of older east-trending faults are the dominant structural features of the Rock Creek - Rocky Point area. The faulting produces a dissected structural high or upthrown basement block of middle to upper Eocene Tillamook Volcanics. Upper Eocene sedimentary units flank the north and south sides with occasional perched sedimentary outliers along the volcanic crest. Although source rock evaluations from this study indicate that the upper Eocene samples are thermally immature, it is possible that thermogenic thy gas at Mist migrated updip from more deeply buried Cowlitz shales and coals or equivalent Eocene strata in the adjacent Tualatin and Astoria basins.