Variation in Lepidopteran Occurrence in Hemlock-Dominated and Deciduous-Dominated Forests of Central Appalachia

Eastern hemlock, (Tsuga canadensis Carrière, Pinaceae), is threatened with extirpation by an exotic invasive herbivore, the hemlock woolly adelgid, (Adelges tsugae Annand, Homoptera: Adelgidae). Given this threat, a broader and more detailed knowledge of the community associated with eastern hem- lock is merited. As Lepidoptera are important members of forest communities, this study was initiated to determine the relative occurrence of Lepidoptera in hemlock-dominated and deciduous-dominated habitats by evaluating abundance, species richness, temporal variation, and composition overlap. Lepidoptera were surveyed using blacklight traps from May – August 2010 at two collection sites in the Appalachian region of eastern Kentucky. The first collection site was within a forest stand dominated by mixed deciduous species, the second site possessed an overstory of eastern hemlock. Lepidoptera ≥ 20 mm in wingspan were identified and enumerated, yielding a total of 1,020 individuals of ≥ 137 species and 18 families. The total number of Lepidoptera captured in May and June was fewer than in July and August (P ≤ 0.05). The composition of the assemblage varied between collection sites as well as seasonally; 85 species were identified at the deciduous site and 107 species were identified at the hemlock site. While 27 species were recorded only at the deciduous site, 49 species were unique to the hemlock site. Of those unique to the hemlock site, five species were either detritivores or conifer specialists. These data demonstrate the importance of both deciduous and hemlock-dominated forest habitats for many species of Lepidoptera in Appalachia. Our study forms a foundation for understanding species richness patterns of Lepidoptera in hemlock forests in North America and is a useful baseline for comparisons of richness and diversity post invasion by the hemlock woolly adelgid

Two point correlations of a trapped interacting Bose gas at finite temperature

We develop a computationally tractable method for calculating correlation functions of the finite temperature trapped Bose gas that includes the effects of s-wave interactions. Our approach uses a classical field method to model the low energy modes and treats the high energy modes using a Hartree-Fock description. We present results of first and second order correlation functions, in position and momentum space, for an experimentally realistic system in the temperature range of $0.6T_c$ to $1.0T_c$. We also characterize the spatial coherence length of the system. Our theory should be applicable in the critical region where experiments are now able to measure first and second order correlations.Comment: 9 pages, 4 figure

Effects of temperature upon the collapse of a Bose-Einstein condensate in a gas with attractive interactions

We present a study of the effects of temperature upon the excitation frequencies of a Bose-Einstein condensate formed within a dilute gas with a weak attractive effective interaction between the atoms. We use the self-consistent Hartree-Fock Bogoliubov treatment within the Popov approximation and compare our results to previous zero temperature and Hartree-Fock calculations The metastability of the condensate is monitored by means of the $l=0$ excitation frequency. As the number of atoms in the condensate is increased, with $T$ held constant, this frequency goes to zero, signalling a phase transition to a dense collapsed state. The critical number for collapse is found to decrease as a function of temperature, the rate of decrease being greater than that obtained in previous Hartree-Fock calculations.Comment: 4 pages LaTeX, 3 eps figures. To appear as a letter in J. Phys.

Audits and inspections are never enough: a critique to enhance food safety

Internal and external food safety audits are conducted to assess the safety and quality of food including on-farm production, manufacturing practices, sanitation, and hygiene. Some auditors are direct stakeholders that are employed by food establishments to conduct internal audits, while other auditors may represent the interests of a second party purchaser or a third-party auditing agency. Some buyers conduct their own audits or additional testing, while some buyers trust the results of third-party audits or inspections. Third-party auditors, however, use various food safety audit standards and most do not have a vested interest in the products being sold. Audits are conducted under a proprietary standard, while food safety inspections are generally conducted within a legal framework. There have been many foodborne illness outbreaks linked to food processors that have passed third-party audits and inspections, raising questions about the utility of both. Supporters argue third-party audits are a way to ensure food safety in an era of dwindling economic resources. Critics contend that while external audits and inspections can be a valuable tool to help ensure safe food, such activities represent only a snapshot in time. This paper identifies limitations of food safety inspections and audits and provides recommendations for strengthening the system, based on developing a strong food safety culture, including risk-based verification steps, throughout the food safety system

Recoverin Regulates Light-dependent Phosphodiesterase Activity in Retinal Rods

The Ca2+-binding protein recoverin may regulate visual transduction in retinal rods and cones, but its functional role and mechanism of action remain controversial. We compared the photoresponses of rods from control mice and from mice in which the recoverin gene was knocked out. Our analysis indicates that Ca2+-recoverin prolongs the dark-adapted flash response and increases the rod's sensitivity to dim steady light. Knockout rods had faster Ca2+ dynamics, indicating that recoverin is a significant Ca2+ buffer in the outer segment, but incorporation of exogenous buffer did not restore wild-type behavior. We infer that Ca2+-recoverin potentiates light-triggered phosphodiesterase activity, probably by effectively prolonging the catalytic activity of photoexcited rhodopsin

User needs, benefits and integration of robotic systems in a space station laboratory

The methodology, results and conclusions of the User Needs, Benefits, and Integration Study (UNBIS) of Robotic Systems in the Space Station Microgravity and Materials Processing Facility are summarized. Study goals include the determination of user requirements for robotics within the Space Station, United States Laboratory. Three experiments were selected to determine user needs and to allow detailed investigation of microgravity requirements. A NASTRAN analysis of Space Station response to robotic disturbances, and acceleration measurement of a standard industrial robot (Intelledex Model 660) resulted in selection of two ranges of low gravity manipulation: Level 1 (10-3 to 10-5 G at greater than 1 Hz.) and Level 2 (less than = 10-6 G at 0.1 Hz). This included an evaluation of microstepping methods for controlling stepper motors and concluded that an industrial robot actuator can perform milli-G motion without modification. Relative merits of end-effectors and manipulators were studied in order to determine their ability to perform a range of tasks related to the three low gravity experiments. An Effectivity Rating was established for evaluating these robotic system capabilities. Preliminary interface requirements were determined such that definition of requirements for an orbital flight demonstration experiment may be established

Seasonal Occurrence and Habitat Affi liations of Trichoptera at Mammoth Cave National Park

The order Trichoptera is an ecologically-important, diverse group of insects. We investigated the relative abundance and occurrence of these insects at Mammoth Cave National Park (MCNP). We focused our efforts on adults captured at blacklight traps placed across four forest habitats in MCNP on 14 nights during 2010-2011. Large-bodied Trichoptera (≥ 10 mm in length) were identified and enumerated, yielding 2,153 specimens of ≥ 45 species and 11 families. Unique captures were recorded at mixed deciduous-dominated, mixed coniferdominated, and upland deciduous sites (13, 4, and 3 species, respectively). While composition of the assemblage varied across collection sites, as well as seasonally, members of the Hydropsychidae (Hydropsyche spp.) and Leptoceridae (Ceraclea spp.) were the most abundant groups. These two families constituted 93% of total abundance and 65% of species richness across all samples. In this study we detail abundance and richness patterns of Trichoptera across a forest landscape and examine habitats for which data are lacking

Long-range sound-mediated dark soliton interactions in trapped atomic condensates

A long-range soliton interaction is discussed whereby two or more dark solitons interact in an inhomogeneous atomic condensate, modifying their respective dynamics via the exchange of sound waves without ever coming into direct contact. An idealized double well geometry is shown to yield perfect energy transfer and complete periodic identity reversal of the two solitons. Two experimentally relevant geometries are analyzed which should enable the observation of this long-range interaction

Gapless finite-TT theory of collective modes of a trapped gas

We present predictions for the frequencies of collective modes of trapped Bose-condensed $^{87}$Rb atoms at finite temperature. Our treatment includes a self-consistent treatment of the mean-field from finite-$T$ excitations and the anomolous average. This is the first gapless calculation of this type for a trapped Bose-Einstein condensed gas. The corrections quantitatively account for the downward shift in the $m=2$ excitation frequencies observed in recent experiments as the critical temperature is approached.Comment: 4 pages Latex and 2 postscript figure