834 research outputs found
Row Width Effects on Corn Yield at Varying Plant Densities
The majority of corn acres in Iowa are planted in “conventional” 30-inch row widths, with some farmers choosing to stay with the 38-inch row system. Questions often arise on the magnitude of yield penalty, whether there really is a yield penalty, or if there is actually a benefit to wider row corn in specific situations with today’s elite hybrids. Recommendations are difficult because current data do not exist. There also is growing interest in narrower row corn (20-inch) and any economical or environmental benefits associated with this practice. These two questions have created a need for more research involving modern hybrids and management practices. The objectives of this study were to (1) identify any row width benefits and (2) determine the optimum planting population for each row width. In addition to this site in 2000, this research was conducted at two other university research farms
“We Are Asking Why You Treat Us This Way. Is It Because We Are Negroes?” A Reparations-Based Approach to Remedying the Trump Administration’s Cancellation of TPS Protections for Haitians
This Article places the Trump Administration’s decision to cancel TPS for Haitians within the longer history of U.S. racism and exclusion against Haiti and Haitians, observes the legal challenges against this decision and their limitations, and imagines a future that repairs the harms caused by past and current racist policies. First, this Article briefly outlines the history of exclusionary, race-based immigration laws in the United States, and specifically how this legal framework, coupled with existing anti-Black ideologies in the United States, directly impacted Haitians and Haitian immigrants arriving in the United States. Next, the Article provides an overview of the TPS decision-making process, the Trump Administration’s openly racist comments against Haitians and other people of color before and during the decision-making process to cancel TPS, and the departure from the established administrative process for TPS cancellation. The Article then reviews the legal challenges against TPS cancellation and the arguments that the decision violated the Equal Protection Clause and how such efforts reveal the limitations of litigation as a tool to achieve social justice.
Looking towards the future, this Article discusses reparations and remittances as creative ways to repair some of the damage wrought by the United States’ history of racial discrimination in immigration and foreign policy against Haitians. Specifically, this Article explores three solutions: (1) recognizing the harms caused specifically to Haitians by the United States’ exclusionary foreign affairs and immigration policies; (2) using material and non-material forms of reparations, including extending TPS, offering a pathway for citizenship for TPS holders, or offering Haitian TPS recipients benefits to public programs; and (3) valuing the role remittances play in affirming Haitians’ autonomy and working towards eroding decades of imperialistic treatment of Haitians
Self-directed career preference selection for individuals with intellectual disabilities: Using computer technology to enhance self-determination
This is the published version. Copyright 2003 IOS Press.Objectives: To conduct a preliminary study investigating the application of a self-directed video and audio software
program to assist individuals with intellectual disabilities to express their vocational job preferences. A working software
prototype, called WorkSight, was developed and field tested.
Study design: The effectiveness of theWorkSight approach was assessed by comparing it to currently used career assessment tools
via ratings by educators and agency professionals. WorkSight was also tested in terms of its efficacy to match the job preferences
that were predicted by the same educators and agency professionals. A total of 25 adults with intellectual disabilities participated
in this study.
Results: Adults with intellectual disabilities were able to use the computer-based job preference assessment to determine career
and job priorities.
Conclusions: The use of technology providing multimedia-based work information has promise to enable persons with intellectual
disabilities to express preferences and to improve job placement and matching activities
The yellow European eel (Anguilla anguilla L.) may adopt a sedentary lifestyle in inland freshwaters
We analysed the movements of the growing yellow phase using a long-term mark–recapture programme on European eels in a small catchment (the Frémur, France). The results showed that of the yellow eels (>200 mm) recaptured, more than 90% were recaptured at the original marking site over a long period before the silvering metamorphosis and downstream migration. We conclude that yellow European eels >200 mm may adopt a sedentary lifestyle in freshwater area, especially in small catchment
Staphylococcus aureus Biofilm and Planktonic cultures differentially impact gene expression, mapk phosphorylation, and cytokine production in human keratinocytes
<p>Abstract</p> <p>Background</p> <p>Many chronic diseases, such as non-healing wounds are characterized by prolonged inflammation and respond poorly to conventional treatment. Bacterial biofilms are a major impediment to wound healing. Persistent infection of the skin allows the formation of complex bacterial communities termed biofilm. Bacteria living in biofilms are phenotypically distinct from their planktonic counterparts and are orders of magnitude more resistant to antibiotics, host immune response, and environmental stress. <it>Staphylococcus aureus </it>is prevalent in cutaneous infections such as chronic wounds and is an important human pathogen.</p> <p>Results</p> <p>The impact of <it>S. aureus </it>soluble products in biofilm-conditioned medium (BCM) or in planktonic-conditioned medium (PCM) on human keratinocytes was investigated. Proteomic analysis of BCM and PCM revealed differential protein compositions with PCM containing several enzymes involved in glycolysis. Global gene expression of keratinocytes exposed to biofilm and planktonic <it>S. aureus </it>was analyzed after four hours of exposure. Gene ontology terms associated with responses to bacteria, inflammation, apoptosis, chemotaxis, and signal transduction were enriched in BCM treated keratinocytes. Several transcripts encoding cytokines were also upregulated by BCM after four hours. ELISA analysis of cytokines confirmed microarray results at four hours and revealed that after 24 hours of exposure, <it>S. aureus </it>biofilm induced sustained low level cytokine production compared to near exponential increases of cytokines in planktonic treated keratinocytes. The reduction in cytokines produced by keratinocytes exposed to biofilm was accompanied by suppressed phosphorylation of MAPKs. Chemical inhibition of MAPKs did not drastically reduce cytokine production in BCM-treated keratinocytes suggesting that the majority of cytokine production is mediated through MAPK-independent mechanisms.</p> <p>Conclusions</p> <p>Collectively the results indicate that <it>S. aureus </it>biofilms induce a distinct inflammatory response compared to their planktonic counterparts. The differential gene expression and production of inflammatory cytokines by biofilm and planktonic cultures in keratinocytes could have implications for the formation and persistence of chronic wounds. The formation of a biofilm should be considered in any study investigating host response to bacteria.</p
Voluntary running exercise protects against sepsis-induced early inflammatory and pro-coagulant responses in aged mice
Background: Despite many animal studies and clinical trials, mortality in sepsis remains high. This may be due to the fact that most experimental studies of sepsis employ young animals, whereas the majority of septic patients are elderly (60 - 70 years). The objective of the present study was to examine the sepsis-induced inflammatory and pro-coagulant responses in aged mice. Since running exercise protects against a variety of diseases, we also examined the effect of voluntary running on septic responses in aged mice. Methods: Male C57BL/6 mice were housed in our institute from 2-3 to 22 months (an age mimicking that of the elderly). Mice were prevented from becoming obese by food restriction (given 70-90% of ad libitum consumption amount). Between 20 and 22 months, a subgroup of mice ran voluntarily on wheels, alternating 1-3 days of running with 1-2 days of rest. At 22 months, mice were intraperitoneally injected with sterile saline (control) or 3.75 g/kg fecal slurry (septic). At 7 h post injection, we examined (1) neutrophil influx in the lung and liver by measuring myeloperoxidase and/or neutrophil elastase in the tissue homogenates by spectrophotometry, (2) interleukin 6 (IL6) and KC in the lung lavage by ELISA, (3) pulmonary surfactant function by measuring percentage of large aggregates, (4) capillary plugging (pro-coagulant response) in skeletal muscle by intravital microscopy, (5) endothelial nitric oxide synthase (eNOS) protein in skeletal muscle (eNOS-derived NO is putative inhibitor of capillary plugging) by immunoblotting, and (6) systemic blood platelet counts by hemocytometry. Results: Sepsis caused high levels of pulmonary myeloperoxidase, elastase, IL6, KC, liver myeloperoxidase, and capillary plugging. Sepsis also caused low levels of surfactant function and platelet counts. Running exercise increased eNOS protein and attenuated the septic responses. Conclusions: Voluntary running protects against exacerbated sepsis-induced inflammatory and pro-coagulant responses in aged mice. Protection against pro-coagulant responses may involve eNOS upregulation. The present discovery in aged mice calls for clinical investigation into potential beneficial effects of exercise on septic outcomes in the elderly
Survey of bacterial diversity in chronic wounds using Pyrosequencing, DGGE, and full ribosome shotgun sequencing
<p>Abstract</p> <p>Background</p> <p>Chronic wound pathogenic biofilms are host-pathogen environments that colonize and exist as a cohabitation of many bacterial species. These bacterial populations cooperate to promote their own survival and the chronic nature of the infection. Few studies have performed extensive surveys of the bacterial populations that occur within different types of chronic wound biofilms. The use of 3 separate16S-based molecular amplifications followed by pyrosequencing, shotgun Sanger sequencing, and denaturing gradient gel electrophoresis were utilized to survey the major populations of bacteria that occur in the pathogenic biofilms of three types of chronic wound types: diabetic foot ulcers (D), venous leg ulcers (V), and pressure ulcers (P).</p> <p>Results</p> <p>There are specific major populations of bacteria that were evident in the biofilms of all chronic wound types, including <it>Staphylococcus, Pseudomonas, Peptoniphilus, Enterobacter, Stenotrophomonas, Finegoldia</it>, and <it>Serratia </it>spp. Each of the wound types reveals marked differences in bacterial populations, such as pressure ulcers in which 62% of the populations were identified as obligate anaerobes. There were also populations of bacteria that were identified but not recognized as wound pathogens, such as <it>Abiotrophia para-adiacens </it>and <it>Rhodopseudomonas </it>spp. Results of molecular analyses were also compared to those obtained using traditional culture-based diagnostics. Only in one wound type did culture methods correctly identify the primary bacterial population indicating the need for improved diagnostic methods.</p> <p>Conclusion</p> <p>If clinicians can gain a better understanding of the wound's microbiota, it will give them a greater understanding of the wound's ecology and will allow them to better manage healing of the wound improving the prognosis of patients. This research highlights the necessity to begin evaluating, studying, and treating chronic wound pathogenic biofilms as multi-species entities in order to improve the outcomes of patients. This survey will also foster the pioneering and development of new molecular diagnostic tools, which can be used to identify the community compositions of chronic wound pathogenic biofilms and other medical biofilm infections.</p
Sequential Grazing Systems for Beef Cattle Production
Pasture productivity in Iowa is often limited by low productivity of cool-season grasses during summer. This uneven seasonal distribution of for age production could be improved by including species in pasture systems that perform better under higher temperatures. Warm-season grasses produce most of their growth during summer when cool-season grasses are semi -dormant. By using cool-season and warm-season pastures in a sequential system it should be possible to improve seasonal productivity. The overall objective of this project i s to evaluate the productivity of sequential grazing system s for beef cattle production in Southern Iowa. Specific objectives are to: 1) evaluate the impact of legumes on the productivity of cool-season pastures grazed in the spring and fall, 2) evaluate warm-season grasses f or summer grazing, and 3) determine the effects of pasture sequence on the productivity of season-long grazing systems
Influence of Introgression and Geological Processes on Phylogenetic Relationships of Western North American Mountain Suckers (Pantosteus, Catostomidae)
Intense geological activity caused major topographic changes in Western North America over the past 15 million years. Major rivers here are composites of different ancient rivers, resulting in isolation and mixing episodes between river basins over time. This history influenced the diversification of most of the aquatic fauna. The genus Pantosteus is one of several clades centered in this tectonically active region. The eight recognized Pantosteus species are widespread and common across southwestern Canada, western USA and into northern Mexico. They are typically found in medium gradient, middle-elevation reaches of rivers over rocky substrates. This study (1) compares molecular data with morphological and paleontological data for proposed species of Pantosteus, (2) tests hypotheses of their monophyly, (3) uses these data for phylogenetic inferences of sister-group relationships, and (4) estimates timing of divergence events of identified lineages. Using 8055 base pairs from mitochondrial DNA protein coding genes, Pantosteus and Catostomus are reciprocally monophyletic, in contrast with morphological data. The only exception to a monophyleticPantosteus is P. columbianus whose mtDNA is closely aligned with C. tahoensis because of introgression. Within Pantosteus, several species have deep genetic divergences among allopatric sister lineages, several of which are diagnosed and elevated to species, bringing the total diversity in the group to 11 species. Conflicting molecular and morphological data may be resolved when patterns of divergence are shown to be correlated with sympatry and evidence of introgression
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