527 research outputs found
The Transformation of Regional Development Agencies through Partnership: From Model Delivery to Catalytic Converter?
EVALUATING THE IMPACT OF INTEGRATED PEST MANAGEMENT ON AGRICULTURE AND THE ENVIRONMENT IN THE TEXAS PANHANDLE
Agricultural producers in the Texas High Plains are facing the worst comparative economic conditions since 1913. Under these circumstances it is desirable to evaluate which programs are beneficial to agricultural producers and which ones are not. The concept of Integrated Pest Management was introduced to the Texas High Plains in 1976 and since then many IPM practices have been adopted for the four major crops; corn, cotton, sorghum, and wheat. The reduction in production cost is used as a measure of economic benefit and contingent valuation is used to estimate the value of the environmental benefits. The IPM practices, which have been adopted, reduce the production cost by more than 99 million per year. The total value of the economic and environmental benefits accruing to the Texas High Plains exceeds $272 million per year.Crop Production/Industries,
Phytoplankton species composition and abundance in a Gulf Stream warm core ring. I. Changes over a five month period
During the spring and summer of 1982, Gulf Stream warm core ring (WCR) 82B was sampled during four cruises from April to August to investigate the changes in the phytoplankton flora with time. Discrete water samples from 28 stations were collected for identification and enumeration of phytoplankton. The spring increase in WCR 828 occurred from late April to mid-May and was multiphasic; early periods were dominated by the diatoms Minidiscus trioculatus (4–5 μm diam.) and a small Thalassiosira, possibly T. bulbosa, while later periods were dominated by a small (2–3 μm) biflagellate. In June, another diatom concentration was detected at ring center, but this one was dominated by Chaetoceros cf. vixvisibilis and Leptocylindrus danicus. After interactions with and overwashes by the Gulf Stream and Slope Water in July, diatom numbers in the surface waters of the ring in August were greatly reduced relative to June, and no single species dominated. Changes in phytoplankton abundance in the ring core occurred on different time sequences from changes in the surrounding Slope Water or in the source water, the Sargasso Sea. The dominant taxa in the ring changed rapidly, on time scales of 1.5 months or less (intercruise time period). Successional changes were more important in altering the phytoplankton composition during the first two cruises, while sequential changes characterized the end of the study period. The ring center showed dramatic differences from its source water just 2 months after ring formation but remained distinct from the Slope Water for 4–5 months
Phytoplankton species composition and abundance in a Gulf Stream warm core ring. II. Distributional patterns
During the spring and summer of 1982, Gulf Stream warm core ring (WCR) 82B was sampled during four cruises from April to August to investigate phytoplankton distributional patterns. Discrete water samples from 28 stations were collected for identification and enumeration of phytoplankton. In April, when the water column was well mixed to 350 m, quantitative samples clustered by station when the 100 most frequently observed taxa were used as variables, indicating fairly unique assemblages at each station that were consistent with depth. Two transects across the ring in June showed a symmetrical diatom abundance maximum, dominated by Chaetoceros cf. vixvisibilis (maximum abundance 31,900 cells l–1) and Leptocylindrus danicus (maximum abundance 21,000 cells l–1), situated in the surface water at ring center. Dinoflagellate and coccolithophorid maxima were situated slightly deeper than the diatom maximum, in the seasonal thermocline from 20 to 35 m. A biomass maximum observed in a Shelf Water entrainment feature wrapping around the eastern perimeter of the ring contained elevated numbers of coccolithophorids and coccoid, unicellular monads (1–3 μm in diameter) and was thus compositionally distinct from the ring center biomass maximum. In July and August the ring underwent numerous interactions with and overwashes by the Slope Water and Gulf Stream. August samples from the ring, Sargasso Sea, Gulf Stream, and Slope Water all contained similar taxa and abundances. Different phytoplankton groups may be responding to different nutrient input mechanisms at the ring edge and center. Diatom maxima at ring center may form as a result of pulsed nutrient input from storms and a slight upwelling due to the gradual relaxation of the thermocline as the ring ages, while concentrations of ultraplanktonic algae (monads, coccolithophorids) toward the ring margin may result from near steady-state nutrient input along sloping isopycnals and/or advection from the ring exterior
Mechanisms of mobile bearing dislocation in lateral unicompartmental knee replacement
Mobile bearing dislocation occurs in 1– 6% of Oxford Domed Lateral replacements. Dislocations are predominantly medial, but can occur anteriorly or posteriorly. They tend to occur when the knee is flexed. It is not clear how dislocations can be prevented. A previously described mechanical rig for assessing mobile bearing dislocation was updated so as to study dislocation with the knee in flexion. Sub-categories for the description of each type of dislocation were introduced. Dislocation was only possible when the knee was distracted. As the amount of distraction possible in the knee is variable, the risk of dislocation is related to the amount of distraction in the rig necessary for a dislocation. The type of dislocation requiring the least distraction was medial `edge' dislocation in which the edge of the bearing dislocates onto the tibial wall, which is the most common type of dislocation. The amount of distraction necessary decreased the further the bearing was from the wall and with 50% posterior overhang. Rotation of the knee did not influence the amount of distraction. In conclusion dislocation can only occur if the lateral compartment is distracted. To reduce the dislocation risk, surgeons should aim to position the femoral and tibial components so that the bearing is as close as possible to the wall without jamming against it and the tibial component should be positioned flush with the posterior tibial cortex. If, during the surgery, the mobile bearing can easily be dislocated onto the wall the surgeon should consider changing to a fixed bearing. The tibial component should also be positioned flush with the posterior tibial cortex, as if it is too far forward this may contribute to dislocation
Anticoagulant rodenticides on our public and community lands: spatial distribution of exposure and poisoning of a rare forest carnivore.
Anticoagulant rodenticide (AR) poisoning has emerged as a significant concern for conservation and management of non-target wildlife. The purpose for these toxicants is to suppress pest populations in agricultural or urban settings. The potential of direct and indirect exposures and illicit use of ARs on public and community forest lands have recently raised concern for fishers (Martes pennanti), a candidate for listing under the federal Endangered Species Act in the Pacific states. In an investigation of threats to fisher population persistence in the two isolated California populations, we investigate the magnitude of this previously undocumented threat to fishers, we tested 58 carcasses for the presence and quantification of ARs, conducted spatial analysis of exposed fishers in an effort to identify potential point sources of AR, and identified fishers that died directly due to AR poisoning. We found 46 of 58 (79%) fishers exposed to an AR with 96% of those individuals having been exposed to one or more second-generation AR compounds. No spatial clustering of AR exposure was detected and the spatial distribution of exposure suggests that AR contamination is widespread within the fisher's range in California, which encompasses mostly public forest and park lands Additionally, we diagnosed four fisher deaths, including a lactating female, that were directly attributed to AR toxicosis and documented the first neonatal or milk transfer of an AR to an altricial fisher kit. These ARs, which some are acutely toxic, pose both a direct mortality or fitness risk to fishers, and a significant indirect risk to these isolated populations. Future research should be directed towards investigating risks to prey populations fishers are dependent on, exposure in other rare forest carnivores, and potential AR point sources such as illegal marijuana cultivation in the range of fishers on California public lands
Virus removal from aqueous environments with polyelectrolyte coatings on a polypropylene fleece
The adsorption of viruses from aqueous solution is frequently performed to detect viruses. Charged filtration materials capture viruses via electrostatic interactions, but lack the specificity of biological virus-binding substances like heparin. Herein, we present three methods to immobilize heparin-mimicking, virus-binding polymers to a filter material. Two mussel-inspired approaches are used, based on dopamine or mussel-inspired dendritic polyglycerol, and post-functionalized with a block-copolymer consisting of linear polyglycerol sulfate and amino groups as anchor (lPGS-b-NH2). As third method, a polymer coating based on lPGS with benzophenone anchor groups is tested (lPGS-b-BPh). All three methods yield dense and stable coatings. A positively charged dye serves as a tool to quantitatively analyze the sulfate content on coated fleece. Especially lPGS-b-BPh is shown to be a dense polymer brush coating with about 0.1 polymer chains per nm2. Proteins adsorb to the lPGS coated materials depending on their charge, as shown for lysozyme and human serum albumin. Finally, herpes simplex virus type 1 (HSV-1) and severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) can be removed from solution upon incubation with coated fleece materials by about 90% and 45%, respectively. In summary, the presented techniques may be a useful tool to collect viruses from aqueous environments
Hnrnph1 Is A Quantitative Trait Gene for Methamphetamine Sensitivity.
Psychostimulant addiction is a heritable substance use disorder; however its genetic basis is almost entirely unknown. Quantitative trait locus (QTL) mapping in mice offers a complementary approach to human genome-wide association studies and can facilitate environment control, statistical power, novel gene discovery, and neurobiological mechanisms. We used interval-specific congenic mouse lines carrying various segments of chromosome 11 from the DBA/2J strain on an isogenic C57BL/6J background to positionally clone a 206 kb QTL (50,185,512-50,391,845 bp) that was causally associated with a reduction in the locomotor stimulant response to methamphetamine (2 mg/kg, i.p.; DBA/2J < C57BL/6J)-a non-contingent, drug-induced behavior that is associated with stimulation of the dopaminergic reward circuitry. This chromosomal region contained only two protein coding genes-heterogeneous nuclear ribonucleoprotein, H1 (Hnrnph1) and RUN and FYVE domain-containing 1 (Rufy1). Transcriptome analysis via mRNA sequencing in the striatum implicated a neurobiological mechanism involving a reduction in mesolimbic innervation and striatal neurotransmission. For instance, Nr4a2 (nuclear receptor subfamily 4, group A, member 2), a transcription factor crucial for midbrain dopaminergic neuron development, exhibited a 2.1-fold decrease in expression (DBA/2J < C57BL/6J; p 4.2 x 10-15). Transcription activator-like effector nucleases (TALENs)-mediated introduction of frameshift deletions in the first coding exon of Hnrnph1, but not Rufy1, recapitulated the reduced methamphetamine behavioral response, thus identifying Hnrnph1 as a quantitative trait gene for methamphetamine sensitivity. These results define a novel contribution of Hnrnph1 to neurobehavioral dysfunction associated with dopaminergic neurotransmission. These findings could have implications for understanding the genetic basis of methamphetamine addiction in humans and the development of novel therapeutics for prevention and treatment of substance abuse and possibly other psychiatric disorders
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