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Studies on controlling oyster drills in Tomales BayHaydock, Clarence Irwin 01 January 1961 (has links) (PDF)
The primary purpose of this study was to evaluate the feasibility of controlling oyster drills in Tomales Bay, particularly Urosalpinx cinerea and Ocenebra Japonica (astropods, Muricidae), with chemicals which have been succesfully tested on a number of oyster pests, Including urosalpinx, in Long Island Sound (Loosanoff , 1956- 1961). The problem was polo to provide information. en the present status of drills alle is the bay, a basic preliminary in evaluating others of pest control.
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The predatory behavior of Pisaster ochraceus (Brandt)Jillson, David A. 01 January 1973 (has links) (PDF)
The persistence of predator-prey systems in evolutionar time is a function of the efficiency with which the predator obtains its food, and the ability of the prey to avoid ex- tinction. One of the important components of survival of the system is environmental heterogeneity (Huffaker 1958).
Along rocky intertidal regions of the northern Pacific coast of North America, a major predator, the starfish Pisast ochraceus has a dominant effect upon patterns of distribution of many intertidal organisms (Paine 1966). Likewise, the distribution of intertidal fauna exert an effect upon the activities of Pisaster. Other biological interactions such an grazing activities of limpets and predatory behavior of emails also affect the intertidal distribution of species (Connell 1961, 1970, Dayton 1971).
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Nutrition and feeding in striped bass Morone saxatilis larvae: Lipid and fatty acid requirements and microencapsulated dietsOzkizilcik, Sureyya 01 January 1995 (has links)
There has been a growing interest in the commercial aquaculture of striped bass, Morone saxatilis. Little is known, however, about the nutritional requirements and feeding physiology of striped bass larvae. The objectives of this study were (a) to evaluate the efficiency of the live food enrichment techniques in studying the nutritional requirements for polyunsaturated fatty acids (PUFA), phospholipids and free amino acids, (b) to determine the ontogenetic changes of lipolytic enzymes, and (c) to develop a microencapsulated diet for striped bass larvae as full or partial replacement of live food. Three enrichment techniques, namely, microencapsulated fish oil, yeast/fish oil emulsion and unicellular algae, Chlorella sp. were evaluated for their efficiency in improving the n-3 PUFA content of Artemia nauplii to striped bass larvae. The enrichment of the Artemia nauplii appeared to increase the eicosapentaenoic acid content and enhance the growth of the striped bass larvae. The uptake and metabolism of &\sp{14}&C-glycine or &\sp{14}&C-phosphatidylcholine labeled liposomes by freshly hatched Artemia nauplii were investigated as a new technique for amino acid and phospholipid. The results of this study suggest that liposomes may be used to enrich Artemia nauplii with phospholipids and free amino acids. Ontogenetic changes of triacylglycerol hydrolase, wax ester hydrolase and phospholipase A&\sb2& were determined in the fertilized eggs and premetamorphosed larvae of striped bass and the larval food Artemia using radioassays. It was estimated that first feeding striped bass larvae had the capacity to digest 47% of their daily lipid ingestion. A complex protein-walled microcapsule (CWC) was prepared by incorporating lipid-wall capsules containing highly water soluble nutrients along with other dietary materials in a cross-linked protein-wall microcapsule. In vitro experiments indicated that the CWC was digested by the crude enzyme extract from striped bass larvae or purified porcine pepsin and trypsin. Diet acceptability, growth and survival of striped bass larvae fed complex protein-walled microcapsules were investigated in two separate experiments. In both experiments, the acceptability of microencapsulated diets was high. Neither microencapsulated diet support growth when solely fed to the larvae. The results of this study suggested that CWC can be used for partial replacement (60%) of live food without any significant effect on growth and survival of striped bass larvae.
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The Effect of the Social Environment on Transition Dairy Cow Behavior and HealthCreutzinger, Katherine C. January 2020 (has links)
No description available.
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Zoometric measures in llamas (Lama glama) of rural families in the T'olar and Pajonal natural grazing fields of the municipality Santiago de Machaca - department of La PazTuco Cano, Eloy 01 January 2009 (has links) (PDF)
Llamas have provided, and continue to provide, fiber, meat, skins, fertilizer and transport for the Andean people. In addition, they are part of the traditional and religious culture of the Aymara and the Quechua. Both are currently unaware of the productive qualities of llamas, especially those related to meat production, which is the principle product responsible for generating greater income for farmers. For this reason, 554 llamas were evaluated from a total of 3,693 in 2005. The llamas came from T’olar and Pajonal grasslands in the Santiago de Machaca region of La Paz, Bolivia and represented males and females from four age categories (newborn, 1-2 years, juvenile, and adult). They were evaluated with the objective of determining the zoometric measurements of llamas fed on T’olar and Pajonal grasses. Evaluations were categorized according to gender and age group, while also applying descriptive statistics of zoometric measurements of llama anatomy including the head, neck, thorax, and abdomen regions, as well as height, weight, and fur thickness. The Pv measurement for T’olar fed llamas (64.4 kg) was higher than that of the Pajonal fed llamas (59.9 kg). With respect to gender, females (67.1 kg) were larger than males (53.0 kg). Adults were the largest age group (89.7 kg), followed by juveniles (85.9 kg), 1-2 years (58.7 kg) and newborns (34.1 kg). The T’olar llamas achieved better results than the Pajonal llamas. Furthermore, females were superior to males, most likely due to the large number of females as compared to males in the llamas. Zoometric measurements increased with age, generally reaching a statistically significant margin (P<0.01) between age groups. Growth was greatest between the newborn and juvenile groups but it ultimately slowed down afterwards.
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Diversity of insects from the Vespidae family in three ecological niches (forest, forest border, and agricultural area) in six communities in the Coroico and Coripata municipalities, department of La PazZapata Mayta, Edwin 01 January 2009 (has links) (PDF)
The Vespidae family (order Hymenoptera) is comprised of 4500 species of wasps in 268 genera and 7 subfamilies. These wasps prey upon a wide range of insects, including Lepidopteran caterpillars. Because of their low prey specificity, the use of Vespid wasps in biological control programs is limited. However, in their natural habitat, they play a role in controlling populations of some pest species. This study was conducted in six different communities in the department of La Paz within the municipalities of Coroico and Coripata. Three ecological niches were selected in each community: 1) the forest, 2) the edge of the forest and 3) a crop producing area. In each study unit, three Malaise traps were set up on a 14 day collection cycle from June to December 2007. Over the six month study period, we collected a total of 772 individuals and identified 36 different morphospecies from the six communities. The most abundant genera collected were Protopolybia sp., Mischocyttarus sp., and an unidentified genus (morphospecies #2) which had the greatest abundance of individuals in all of the different ecological niches. The niche factor did not have a significant influence on species diversity in the three ecological niches studied. Generally, this group of wasps is found in all three ecological niches.
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Control of <em>Alternaria solani</em> Resistance to Boscalid, Fluopyram, and ChlorothalonilHollingshead, Andrew K 01 December 2015 (has links) (PDF)
Alternaria solani, cause of early blight, threatens potato yields. Fungicide resistance has made control of early blight difficult and there are concerns that in-season fungicide use results in resistance to boscalid, fluopyram, and chlorothalonil. Concern of high levels of resistance to boscalid a group 7 fungicide may confer cross-resistance to fungicides of the same group such as fluopyram. From 2014 to 2015, A. solani isolates were collected from field plots treated with boscalid, fluopyram, and chlorothalonil to test resistance levels. Isolates were determined resistant if EC50 values were higher than 5 µg ml-1. Boscalid and chlorothalonil mean EC50 values decreased two fold from 2014 to 2015, while fluopyram values increased two fold. A negative correlation between fluopyram and boscalid indicate no cross-resistance. Higher resistance levels to fluopyram (17.1 µg ml-1) were observed in the treatment C-14 where only fluopyram was applied in 2014. Treatments D-14 and D-15, only treated with chlorothalonil, had the highest mean EC50 values to chlorothalonil (2.3 and 1.1 µg ml-1, respectively). Field trials show fluopyram+chlorothalonil had lowest disease severity of 6.6 to 6.8%. Leaf residues of boscalid fluopyram, and chlorothalonil measured an average of 10.2, 4.9, and 55.0 ppm on leaves throughout the canopy. After 14 days average residues diminished to 0.74, 0.39, and 16.9 ppm for boscalid, fluopyram and chlorothalonil, respectively. Boscalid is not effective for early blight control because of high resistance; fluopyram resistance is increasing as treatments of fluopyram are applied; and chlorothalonil does not seem to be affected by continued fungicide application.
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The Effect of Prostaglandin Inhibitor on Pregnancy Rates of Heifer Embryo Transfer RecipientsMcNaughtan, Jared William 23 December 2004 (has links) (PDF)
Manipulation of the reproductive tract results in increased levels of prostaglandin, which may, in turn, reduce pregnancy rates in embryo recipients. Administration of a prostaglandin inhibitor prior to embryo transfer improves pregnancy rates in cows. Embryo transfer into heifers is more difficult and often requires additional manipulation of the uterus. This study was designed to determine whether administration of the prostaglandin inhibitor, flunixin meglumine, immediately prior to embryo transfer increases pregnancy rates in heifers. Heifers (n=466) were divided into two equal groups based on BCS (range=6-7) and weight (range=256-455). Estrus was synchronized in heifers by giving two injections of prostaglandin F_2" (PGF) eleven days apart with a two day stagger between groups. Heifers in each group were watched for estrus for four days following the second PGF injection. Each heifer detected in estrus (n~389; 83%) was palpated seven days later for the presence and location of an acceptable corpus luteum; development of the reproductive tract (uterine tract score; 1=prepubertal, 5=mature tract) and amount of uterine tone (uterine tone score; l=high tone, 2=medium tone, 3=low tone) were also estimated. The 352 heifers that had an acceptable CL were paired based on day of detected estrus, body condition score, body weight, and uterine tone score. One heifer of each pair was randomly assigned to receive 10ml of flunixin meglumine (IM) just prior to embryo transfer. Time between injection until completion of embryo transfer ranged from 2-25 minutes. All heifers received a single frozen/thawed embryo transferred by one of two experienced technicians. Data collected at the time of transfer included cervix score (1-3; 1=easily penetrated, 3=difficult), ease of transfer score (1-3; l=gun easily manipulated to site of transfer, 3=difficult), embryo placement in the uterine horn (U=upper 1/3, M=middle 1/3, L=lower 1/3), and technician. Pregnancy results were obtained 90 days after transfer via rectal palpation. The logistics procedures and chi-square analysis of SAS were used for data analysis.
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Calorespirometric Evidence for Adaptation of Blackbrush and Shadscale to Growth Season Temperatures in Cold DesertsSummers, Heidi A. 24 February 2005 (has links) (PDF)
Coleogyne ramosissima Torr. (blackbrush) and Atriplex confertifolia [Torr. & Frem.] Wats. (shadscale) are cold desert shrubs from different families that often grow together in the Great Basin and the Colorado Plateau in the life zone between 800 and 2000 m elevation. Tissue and seeds from the two species were collected from several localities. Metabolic heat and carbon dioxide production rates were measured with calorespirometry on tissue from field-grown plants and on seedlings at temperatures from 5 to 35°C at 5°C intervals. Blackbrush adapts to higher temperatures earlier than does shadscale, and once it has adjusted to higher temperatures, anabolic rates keep rising with increasing temperature while for shadscale rates flatten out or drop off between 25 and 35°C. Both species are metabolically adapted to temperatures during the growth season determined by the historical rainfall pattern.
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Pressurized Hot Water: An Alternative Method of Nutrient Extraction and Subsequent Analysis for Use in Small-Scale AgricultureCrane, Kristy Susanne 13 July 2004 (has links) (PDF)
Soil analysis for small acreage farms in developing countries is often inconvenient and prohibitively expensive using current procedures, yet the information gained from these soil tests could have economical and environmental benefits. The pressurized hot-water (PHW) extraction coupled with colorimetric or turbidimetric analyses shows promise as an alternative to current procedures. Accepted methods of colorimetric analysis for NO3-N and P exist but an alternative method to atomic absorption spectrometry for K analysis is needed. Of the many possible methods to quantify K, tests performed in the Brigham Young University (BYU) laboratory found sodium tetraphenylborate to be unsatisfactory and sodium cobaltinitrite to be simple, inexpensive and consistent. Test results on 38 arid-zone soils from the Western United States encourage adoption of sodium cobaltinitrite as an acceptable procedure for K quantification in conjunction with PHW extraction [r2 of 0.90 compared to atomic absorption (AA) analysis and r2 of 0.67 compared to values extracted with ammonium acetate and measured with AA]. Two hundred twenty-eight soils varying widely in soil parameters from different areas of Guatemala and Morocco were analyzed for NO3-N, P and K using standard methods (water-CTA, Olsen-molybdic acid and ammonium acetate-atomic absorption, respectively) and correlated to values obtained from the PHW extraction coupled with colorimetric or turbidimetric analytical procedures at BYU. The correlations between the values for these tests were good (r2 of 0.96, 0.71 and 0.52 for NO3-N, P, and K; respectively). Soils from each country were simultaneously analyzed for NO3-N and P in laboratories in Guatemala and Morocco and these results correlated with those from BYU. Correlations between BYU values and those from other laboratories gave generally positive results with the Guatemala laboratory showing overall closer correlation with BYU values than data from the Morocco laboratory. The results suggest that the PHW extraction and accompanying simplified analyses present a viable, less expensive alternative to current soil nutrient extraction and analysis procedures for the range of soils tested from Morocco and Guatemala.
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