Evaluation of Acetochlor and other Very-Long-Chain Fatty Acid-Inhibiting Herbicides in Arkansas Rice

The prevalence of herbicide resistance and lack of effective management options for controlling problematic weeds such as barnyardgrass and weedy rice in Arkansas rice production has led to exploration of alternative herbicide sites of action (SOA). Very-long-chain fatty acid (VLCFA)-inhibiting herbicides are not currently labeled for use in U.S. rice production but have been used with success in other row crops and in rice production in Asia. Based on preliminary research, rice tolerance and weed control were evaluated following various application timings and rates of acetochlor and pethoxamid, in addition to several other VLCFA-inhibiting herbicides. Rice tolerance to acetochlor was maximized when applied in a microencapsulated (ME) formulation at the 1-leaf growth stage. Rice also demonstrated adequate tolerance to ME acetochlor applied delayed-preemergence (DPRE); however, when activating rainfall was received soon after application, unacceptable rice injury was observed and is therefore not recommended. When properly activated, barnyardgrass control and rough rice yield was comparable between acetochlor-based herbicide programs and clomazone-based programs in Clearfield and Provisia rice systems. However, it should be noted that early-season barnyardgrass control and rough rice yields were generally higher following clomazone-based herbicide programs due to minimal rice injury and excellent barnyardgrass control in all environments. Both ME acetochlor and pethoxamid provided early-season control of weedy rice and other grass species when applied soon after planting. Although DPRE applications were the most effective for weed control, they pose extreme risk for rice injury and should be avoided. In contrast, weed control was slightly reduced by delaying applications to 1-leaf rice but risk for rice injury was also decreased. Winter-applied VLCFA-inhibiting herbicides caused tolerable injury to rice planted the following spring. Microencapsulated acetochlor and pyroxasulfone provided considerable suppression of weedy rice for as long as seven weeks after planting, suggesting an alternative method for controlling weedy rice. Should ME acetochlor and pethoxamid be registered for use in U.S. rice production, they have potential to provide growers with an alternative SOA to combat herbicide resistance and control problematic weed species

Gas-Grain Simulation Facility: Fundamental studies of particle formation and interactions. Volume 2: Abstracts, candidate experiments and feasibility study

An overview of the Gas-Grain Simulation Facility (GGSF) project and its current status is provided. The proceedings of the Gas-Grain Simulation Facility Experiments Workshop are recorded. The goal of the workshop was to define experiments for the GGSF--a small particle microgravity research facility. The workshop addressed the opportunity for performing, in Earth orbit, a wide variety of experiments that involve single small particles (grains) or clouds of particles. Twenty experiments from the fields of exobiology, planetary science, astrophysics, atmospheric science, biology, physics, and chemistry were described at the workshop and are outlined in Volume 2. Each experiment description included specific scientific objectives, an outline of the experimental procedure, and the anticipated GGSF performance requirements. Since these experiments represent the types of studies that will ultimately be proposed for the facility, they will be used to define the general science requirements of the GGSF. Also included in the second volume is a physics feasibility study and abstracts of example Gas-Grain Simulation Facility experiments and related experiments in progress

Gas-Grain Simulation Facility: Fundamental studies of particle formation and interactions. Volume 1: Executive summary and overview

An overview of the Gas-Grain Simulation Facility (GGSF) project and its current status is provided. The proceedings of the Gas-Grain Simulation Facility Experiments Workshop are recorded. The goal of the workshop was to define experiments for the GGSF--a small particle microgravity research facility. The workshop addressed the opportunity for performing, in Earth orbit, a wide variety of experiments that involve single small particles (grains) or clouds of particles. The first volume includes the executive summary, overview, scientific justification, history, and planned development of the Facility

Population Structure Analyses Provide Insight into the Source Populations Underlying Rural Isolated Communities in Illinois

We have previously hypothesized that relatively small and isolated rural communities may experience founder effects, defined as the genetic ramifications of small population sizes at the time of a community’s establishment. To explore this, we used an Illumina Infinium Omni2.5Exome-8 chip to collect data from 157 individuals from four Illinois communities, three rural and one urban. Genetic diversity estimates of 999,259 autosomal markers suggested that the reduction in heterozygosity due to shared ancestry was approximately 0, indicating a randomly mating population. An eigenanalysis, which is similar to a principal component analysis but ran on a genetic coancestry matrix, conducted in the SNPRelate R package revealed that the majority of these individuals formed one cluster with a few putative outliers obscuring population variation. An additional eigenanalysis on the same markers in a combined data set including the 2,504 individuals in the 1000 Genomes database found that most of the 157 Illinois individuals clustered into one group in close proximity to individuals of European descent. A final eigenanalysis of the Illinois individuals with the 503 individuals of European descent (within the 1000 Genomes Project) revealed two clusters of individuals and likely two source populations; one British and one consisting of multiple European subpopulations. We therefore demonstrate the feasibility of examining genetic relatedness across Illinois populations and assessing the number of source populations using publicly available databases. When assessed, it becomes possible for population structure information to contribute to the understanding of genetic history in rural populations

Fragmentation production of doubly heavy baryons

Baryons with a single heavy quark are being studied experimentally at present. Baryons with two units of heavy flavor will be abundantly produced not only at future colliders, but also at existing facilities. In this paper we study the production via heavy quark fragmentation of baryons containing two heavy quarks at the Tevatron, the LHC, HERA, and the NLC. The production rate is woefully small at HERA and at the NLC, but significant at $pp$ and $p\bar{p}$ machines. We present distributions in various kinematical variables in addition to the integrated cross sections at hadron colliders.Comment: 13 pages, macro package epsfig needed, 6 .eps figure files in a separate uuencoded, compressed and tarred file; complete paper available at http://www.physics.carleton.ca/~mad/papers/paper.p

Convergent Neural Correlates of Empathy and Anxiety During Socioemotional Processing

Empathy is characterized by the ability to understand and share an emotional experience with another person and is closely tied to compassion and concern for others. Consequently, this increased emotional awareness and sensitivity may also be related to increased anxiety. Taken from another perspective, higher general anxiety may translate into increased concern for others, or concern for how one’s actions might affect others, and therefore may be linked to increased empathy. Furthermore, self-reflection is positively related to perspective-taking and empathic concern, while rumination is closely tied to anxiety, thus providing an additional connecting point between empathy and anxiety through enhanced internally generated thought. While previous literature suggests a relationship between empathy and anxiety, this has yet to be empirically studied using neuroimaging tools aimed at investigating the underlying neural correlates that may support these convergent responses. We therefore conducted an functional magnetic resonance imaging (fMRI) study (N = 49) in which participants viewed fearful and neutral human faces and rated how the faces made them feel, to promote introspection. Participants also completed questionnaires assessing empathy Toronto Empathy Questionnaire (TEQ), trait anxiety State Trait Anxiety Inventory (STAI), worry Penn State Worry Questionnaire (PSWQ) and rumination Ruminative Responses Scale (RRS). Behaviorally, empathy positively correlated with worry, worry and rumination positively correlated with anxiety, and significant indirect relationships were found between empathy and anxiety through worry and rumination. Using the neuroimaging face processing task as a backdrop on which the neurobiological mechanisms of empathy and anxiety may interact, regressions of questionnaires with brain activations revealed that empathy related to activation in the temporoparietal junction (TPJ), anxiety related to bilateral insula activation, and worry related to medial prefrontal cortex (mPFC) activation, while rumination showed increased engagement of all three aforementioned regions. Functional connectivity (FC) analyses showed increased communication between the left amygdala and insula related to higher empathy, worry and rumination. Finally, whole-brain analysis using median split groups from questionnaires revealed that the lower halves of anxiety, worry and rumination exhibited increased activation in top-down attentional networks. In sum, empathy, worry and rumination related to enhanced bottom-up processing, while worry, rumination and anxiety exhibited decreased top-down attentional control, suggesting an indirect relationship between empathy and anxiety through the ruminative tendencies of worry

Infrared enhanced analytic coupling and chiral symmetry breaking in QCD

We study the impact on chiral symmetry breaking of a recently developed model for the QCD analytic invariant charge. This charge contains no adjustable parameters, other than the QCD mass scale $\Lambda$, and embodies asymptotic freedom and infrared enhancement into a single expression. Its incorporation into the standard form of the quark gap equation gives rise to solutions for the dynamically generated mass that display a singular confining behaviour at the origin. Using the Pagels-Stokar method we relate the obtained solutions to the pion decay constant $f_{\pi}$, and estimate the scale parameter $\Lambda$, in the presence of four active quarks, to be about 880 MeV.Comment: 14 pages, 3 figures; to appear in J. Phys.

Supersymmetric Extra Dimensions: Gravitino Effects in Selectron Pair Production

We examine the phenomenological consequences of a supersymmetric bulk in the scenario of large extra dimensions. We assume supersymmetry is realized in the bulk and study the interactions of the resulting bulk gravitino Kaluza-Klein (KK) tower of states, with supersymmetry breaking on the brane inducing a light mass for the zero-mode gravitino. We derive the 4-d effective theory, including the couplings of the bulk gravitino KK states to fermions and their scalar superpartners. The virtual exchange of the gravitino KK states in selectron pair production in polarized \epem collisions is then examined. We find that the leading order operator for this exchange is dimension six, in contrast to that of bulk graviton KK exchange which induces a dimension eight operator at lowest order. The resulting kinematic distributions for selectron production are dramatically altered from those in D=4 supersymmetric scenarios, and can lead to a enormous sensitivity to the fundamental higher dimensional Planck scale, of order $20-25\times \sqrt s$.Comment: 48 pg

Occupational asphalt is not associated with head and neck cancer

Epidemiologic studies that evaluate the relationship between occupational asphalt exposure and head and neck cancer have had a limited ability to control for known risk factors such as smoking, alcohol and human papillomavirus (HPV)

Natural Variation in Decision-Making Behavior in Drosophila melanogaster

There has been considerable recent interest in using Drosophila melanogaster to investigate the molecular basis of decision-making behavior. Deciding where to place eggs is likely one of the most important decisions for a female fly, as eggs are vulnerable and larvae have limited motility. Here, we show that many natural genotypes of D. melanogaster prefer to lay eggs near nutritious substrate, rather than in nutritious substrate. These preferences are highly polymorphic in both degree and direction, with considerable heritability (0.488) and evolvability