Characterizing bean pod rot in Arkansas and Missouri

Green beans are an important crop grown for processing in both Arkansas and Missouri. Green beans are harvested mechanically using non-selective picking fingers. Harvested beans are then transported in bulk to processing plants that are located at various locations throughout the midSouth. Thus, the crop is managed for high quality, avoiding pod blemishes caused by insects and diseases. One of the consistent quality problems that affect Arkansas and Missouri green bean crops is pod rot. Two of the causal agents of pod rot that have been reported by researchers and vegetable companies alike are Pythium aphanidermatum and an unidentified Phytophthora sp. In this study, 15 growers’ fields were selected and soil samples (at planting), pod samples (at harvest), and environmental data were taken from each field. Disease incidence for field sites ranged from 0 to 7.3%. Pathogens associated with pod rot were Sclerotinia sclerotiorum, Rhizoctonia solani, a Phytophthora sp., and Pythium spp. The two suspected causal agents for pod rot, Pythium and Phytophthora spp., were found in all but one of the 12 field sites assessed for pod rot. Pythium inoculum potential, as determined by a baiting technique, was not a good indicator of pod rot incidence. In addition, soil temperature and water were not associated with pod rot. Pods collected at harvest having symptoms of pod rot were either in direct contact with the soil, senescing leaf tissue, or other diseased pods

Flatfish herding behavior in response to trawl sweeps: a comparison of diel responses to conventional sweeps and elevated sweeps

Commercial bottom trawls often have sweeps to herd fish into the net. Elevation of the sweeps off the seaf loor may reduce seafloor disturbance, but also reduce herding effectiveness. In both field and laboratory experiments, we examined the behavior of flatfish in response to sweeps. We tested the hypotheses that 1) sweeps are more effective at herding flatfish during the day than at night, when fish are unable to see approaching gear, and that 2) elevation of sweeps off the seafloor reduces herding during the day, but not at night. In sea trials, day catches were greater than night catches for four out of six flatfish species examined. The elevation of sweeps 10 cm significantly decreased catches during the day, but not at night. Laboratory experiments revealed northern rock sole (Lepidopsetta polyxystra) and Pacific halibut (Hippoglossus stenolepis) were more likely to be herded\ud by the sweep in the light, whereas in the dark they tended to pass under or over the sweep. In the light, elevation of the sweep reduced herding, and more fish passed under the sweep. In contrast, in the dark, sweep elevation had little effect upon the number of fish that exhibited herding behavior. The results of both field and laboratory experiments were consistent with the premise that vision is the principle sensory input that controls fish behavior and orientation to trawl gear, and gear performance will differ between conditions where flatfish can see, in contrast to where they cannot see, the approaching gear

HOPE Longitudinal Study: Year 2 Results

Abstract pending

The discount window : time for reform?

For many years, the Federal Reserve's discount window has played an important role in monetary policy. Discount window borrowing helps individual depository institutions manage their reserve accounts in the presence of unexpected deposit and payments flows. Improved reserve management, in turn, helps stabilize the overnight federal funds market by reducing the volatility of short-term interest rates. Moreover, announced changes in the Federal Reserve's discount rate have often signaled important shifts in the stance of monetary policy and have frequently been associated with large changes in market interest rates, exchange rates, and asset prices.> In the 1990s, however, fewer and fewer institutions have relied on the window to meet short-term credit needs. Consequently, the usefulness of the discount window in smoothing reserve imbalances and stabilizing interest rates may have been reduced. In addition, changes in monetary policy operating procedures and the formal announcement of monetary policy decisions by the Federal Reserve may have reduced the effectiveness of discount rate changes in influencing market interest rates and asset prices.> Hakkio and Sellon analyze the changing role of the discount window in monetary policy and examine the case for discount window reform. One alternative to the traditional discount window is a "Lombard-type" lending facility in which depository institutions can borrow more freely than under the current system but at a higher rate. While there appear to be good arguments in favor of modernizing the discount mechanism, a number of conceptual and practical issues must be addressed before implementing a Lombard-type lending facility. An additional consideration, going forward, is the projected reduction in the supply of Treasury debt over the next few years. A shrinking supply of Treasury securities could complicate the use of open market operations in providing reserves to the banking system and require the Federal Reserve to place greater emphasis on the discount window. Consequently, any redesign of the discount window would need to address this issue.Discount window ; Discount ; Monetary policy

Chipping away at gamma-H2AX foci

The mammalian histone H2AX protein functions as a dosage-dependent genomic caretaker and tumor suppressor. Phosphorylation of H2AX to form gamma-H2AX in chromatin around DNA double strand breaks (DSBs) is an early event following induction of these hazardous lesions. For a decade, mechanisms that regulate H2AX phosphorylation have been investigated mainly through two-dimensional immunofluorescence (IF). We recently used chromatin immunoprecipitation (ChIP) to measure gamma-H2AX densities along chromosomal DNA strands broken in G(1) phase mouse lymphocytes. Our experiments revealed that (1) gamma-H2AX densities in nucleosomes form at high levels near DSBs and at diminishing levels farther and farther away from DNA ends, and (2) ATM regulates H2AX phosphorylation through both MDC1-dependent and MDC1-independent means. Neither of these mechanisms were discovered by previous if studies due to the inherent limitations of light microscopy. Here, we compare data obtained from parallel gamma-H2AX ChIP and three-dimensional IF analyses and discuss the impact of our findings upon molecular mechanisms that regulate H2AX phosphorylation in chromatin around DNA breakage sites

Studying the Nature of Dark Energy with Galaxy Clusters

We report on the status of our effort to constrain the nature of dark energy through the evolution of the cluster mass function. Chandra temperature profiles for 31 clusters from a local cluster sample are shown. The X-ray appearance of the proto supermassive binary black hole at the center of the cluster Abell 400 is described. Preliminary weak lensing results obtained with Megacam@MMT for a redshift z=0.5 cluster from a distant cluster sample are given.Comment: 5 pages, to appear in: Aschenbach, B., Burwitz, V., Hasinger, G., Leibundgut, B. (eds.), Relativistic Astrophysics and Cosmology - Einstein's Legacy. ESO Astrophysics Symposia, Springer Verlag, Berlin, German

The limitations of speech control: perceptions of provision of speech-driven environmental controls

This study set out to collect data from assistive technology professionals about their provision of speech-driven environmental control systems. This study is part of a larger study looking at developing a new speech-driven environmental control system

The Amazing Old Nova Q Cygni: A Far Ultraviolet Synthetic Spectral Analysis

Q Cygni (Nova Cygni 1876) is the third oldest old novae (after WY Sge and V841 Oph) with a long orbital period of 10.08 hours and spectroscopic peculiarities in the optical including the presence of variable wind outflow revealed by optical P Cygni profiles in the HeI lines and H alpha beta (Kafka et al. 2003). We have carried out a synthetic spectral analysis of a far ultraviolet IUE archival spectrum of Q Cygni using our optically thick, steady state, accretion disk models and model white dwarf photospheres. We find that the accretion light of a luminous accretion disk dominates the FUV flux of the hot component with a rate of accretion 2-3 1.E-9 Msun/yr. We find that Q Cygni lies at a distance of 741 \pm 110 pc . The implications of our results for theoretical predictions for old novae are presented.Comment: PASP, August 201

Weakly Equivalent Arrays

The (extensional) theory of arrays is widely used to model systems. Hence, efficient decision procedures are needed to model check such systems. Current decision procedures for the theory of arrays saturate the read-over-write and extensionality axioms originally proposed by McCarthy. Various filters are used to limit the number of axiom instantiations while preserving completeness. We present an algorithm that lazily instantiates lemmas based on weak equivalence classes. These lemmas are easier to interpolate as they only contain existing terms. We formally define weak equivalence and show correctness of the resulting decision procedure

Cyclic and constant temperature aging effects on magnetic materials for inverters and converters

Cyclic and constant temperature aging effects on magnetic materials for inverters and converter