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

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

XMM-Newton observations of the supernova remnant IC443: I. soft X-ray emission from shocked interstellar medium

The shocked interstellar medium around IC443 produces strong X-ray emission in the soft energy band (E<1.5 keV). We present an analysis of such emission as observed with the EPIC MOS cameras on board the XMM-Newotn observatory, with the purpose to find clear signatures of the interactions with the interstellar medium (ISM) in the X-ray band, which may complement results obtained in other wavelenghts. We found that the giant molecular cloud mapped in CO emission is located in the foreground and gives an evident signature in the absorption of X-rays. This cloud may have a torus shape and the part of torus interacting with the IC443 shock gives rise to 2MASS-K emission in the southeast. The measured density of emitting X-ray shocked plasma increases toward the northeastern limb, where the remnant is interacting with an atomic cloud. We found an excellent correlation between emission in the 0.3-0.5 keV band and bright optical/radio filament on large spatial scales. The partial shell structure seen in this band therefore traces the encounter with the atomic cloud.Comment: 10 pages, 10 figures, accepted for publication in ApJ (20 September 2006, v649). For hi-res figures, see http://www.astropa.unipa.it/Library/OAPA_preprints/ic443ele1.ps.g

ASCA Observations of the Supernova Remnant IC 443: Thermal Structure and Detection of Overionized Plasma

We present the results of X-ray spatial and spectral studies of the ``mixed-morphology'' supernova remnant IC 443 using ASCA. IC 443 has a center-filled image in X-ray band, contrasting with the shell-like appearance in radio and optical bands. The overall X-ray emission is thermal, not from a synchrotron nebula. ASCA observed IC 443 three times, covering the whole remnant. From the image analysis, we found that the softness-ratio map reveals a shell-like structure. At the same time, its spectra require two (1.0 keV and 0.2 keV) plasma components; the emission of the 0.2 keV plasma is stronger in the region near the shell than the center. These results can be explained by a simple model that IC 443 has a hot (1.0 keV) interior surrounded by a cool (0.2 keV) outer shell. From the emission measures, we infer that the 0.2 keV plasma is denser than the 1.0 keV plasma, suggesting pressure equilibrium between the two. In addition, we found that the ionization temperature of sulfur, obtained from H-like K$\alpha$ to He-like K$\alpha$ intensity ratio, is 1.5 keV, significantly higher than the gas temperature of 1.0 keV suggested from the continuum spectrum. The same can be concluded for silicon. Neither an additional, hotter plasma component nor a multi-temperature plasma successfully accounts for this ratio, and we conclude that the 1.0 keV plasma is overionized. This is the first time that overionized gas has been detected in a SNR. For the gas to become overionized in the absence of a photoionizing flux, it must cool faster than the ions recombine. Thermal conduction from the 1.0 keV plasma to the 0.2 keV one could cause the 1.0 keV plasma to become overionized, which is plausible within an old (3$\times10^4$ yr) SNR.Comment: 11 pages, 15 figures, 2 tables, accepted for publication in The Astrophysical Journa

Isolated X-ray -- infrared sources in the region of interaction of the supernova remnant IC 443 with a molecular cloud

The nature of the extended hard X-ray source XMMU J061804.3+222732 and its surroundings is investigated using XMM-Newton, Chandra, and Spitzer observations. This source is located in an interaction region of the IC 443 supernova remnant with a neighboring molecular cloud. The X-ray emission consists of a number of bright clumps embedded in an extended structured non-thermal X-ray nebula larger than 30" in size. Some clumps show evidence for line emission at ~1.9 keV and ~3.7 keV at the 99% confidence level. Large-scale diffuse radio emission of IC 443 passes over the source region, with an enhancement near the source. An IR source of about 14" x 7" size is prominent in the 24 um, 70 um, and 2.2 um bands, adjacent to a putative Si K-shell X-ray line emission region. The observed IR/X-ray morphology and spectra are consistent with those expected for J/C-type shocks of different velocities driven by fragmented supernova ejecta colliding with the dense medium of a molecular cloud. The IR emission of the source detected by Spitzer can be attributed to both continuum emission from an HII region created by the ejecta fragment and line emission excited by shocks. This source region in IC 443 may be an example of a rather numerous population of hard X-ray/IR sources created by supernova explosions in the dense environment of star-forming regions. Alternative Galactic and extragalactic interpretations of the observed source are also discussed.Comment: The Astrophysical Journal, v. 677 (April 2008), in pres

MAGIC J0616+225 as delayed TeV emission of cosmic-rays diffusing from SNR IC 443

We present a theoretical model that explains the high energy phenomenology of the neighborhood of SNR IC 443, as observed with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope and the Energetic Gamma-Ray Experiment Telescope (EGRET). We interpret MAGIC J0616+225 as delayed TeV emission of cosmic-rays diffusing from IC 443 and interacting with a known cloud located at a distance of about 20 pc in the foreground of the remnant. This scenario naturally explains the displacement between EGRET and MAGIC sources, their fluxes, and their spectra. We compare this model with others recently presented, and discuss how it can be tested with observations by the Gamma-ray Large Area Telescope (GLAST).Comment: Accepted for publication in MNRAS Letter

RNAi Screening in Drosophila Cells Identifies New Modifiers of Mutant Huntingtin Aggregation

The fruitfly Drosophila melanogaster is well established as a model system in the study of human neurodegenerative diseases. Utilizing RNAi, we have carried out a high-throughput screen for modifiers of aggregate formation in Drosophila larval CNS-derived cells expressing mutant human Huntingtin exon 1 fused to EGFP with an expanded polyglutamine repeat (62Q). 7200 genes, encompassing around 50% of the Drosophila genome, were screened, resulting in the identification of 404 candidates that either suppress or enhance aggregation. These candidates were subjected to secondary screening in normal length (18Q)-expressing cells and pruned to remove dsRNAs with greater than 10 off-target effects (OTEs). De novo RNAi probes were designed and synthesized for the remaining 68 candidates. Following a tertiary round of screening, 21 high confidence candidates were analyzed in vivo for their ability to modify mutant Huntingtin-induced eye degeneration and brain aggregation. We have established useful models for the study of human HD using the fly, and through our RNAi screen, we have identified new modifiers of mutant human Huntingtin aggregation and aggregate formation in the brain. Newly identified modifiers including genes related to nuclear transport, nucleotide processes, and signaling, may be involved in polyglutamine aggregate formation and Huntington disease cascades

Anatomical-Molecular Distribution of EphrinA1 in Infarcted Mouse Heart Using MALDI Mass Spectrometry Imaging

EphrinA1 is a tyrosine kinase receptor localized in the cellular membrane of healthy cardiomyocytes, the expression of which is lost upon myocardial infarction (MI). Intra-cardiac injection of the recombinant form of ephrinA1 (ephrinA1-Fc) at the time of ligation in mice has shown beneficial effects by reducing infarct size and myocardial necrosis post-MI. To date, immunohistochemistry and Western blotting comprise the only experimental approaches utilized to localize and quantify relative changes of ephrinA1 in sections and homogenates of whole left ventricle, respectively. Herein, we used matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) coupled with a time-of-flight mass spectrometer (MALDI/TOF MS) to identify intact as well as tryptic fragments of ephrinA1 in healthy controls and acutely infarcted murine hearts. The purpose of the present study was 3-fold: (1) to spatially resolve the molecular distribution of endogenous ephrinA1, (2) to determine the anatomical expression profile of endogenous ephrinA1 after acute MI, and (3) to identify molecular targets of ephrinA1-Fc action post-MI. The tryptic fragments detected were identified as the ephrinA1-isoform with 38% and 34% sequence coverage and Mascot scores of 25 for the control and MI hearts, respectively. By using MALDI-MSI, we have been able to simultaneously measure the distribution and spatial localization of ephrinA1, as well as additional cardiac proteins, thus offering valuable information for the elucidation of molecular partners, mediators, and targets of ephrinA1 action in cardiac muscle.Open Access Fun

Assessing non-Mendelian inheritance in inherited axonopathies

PURPOSE: Inherited axonopathies (IA) are rare, clinically and genetically heterogeneous diseases that lead to length-dependent degeneration of the long axons in central (hereditary spastic paraplegia [HSP]) and peripheral (Charcot–Marie–Tooth type 2 [CMT2]) nervous systems. Mendelian high-penetrance alleles in over 100 different genes have been shown to cause IA; however, about 50% of IA cases do not receive a genetic diagnosis. A more comprehensive spectrum of causative genes and alleles is warranted, including causative and risk alleles, as well as oligogenic multilocus inheritance. METHODS: Through international collaboration, IA exome studies are beginning to be sufficiently powered to perform a pilot rare variant burden analysis. After extensive quality control, our cohort contained 343 CMT cases, 515 HSP cases, and 935 non-neurological controls. We assessed the cumulative mutational burden across disease genes, explored the evidence for multilocus inheritance, and performed an exome-wide rare variant burden analysis. RESULTS: We replicated the previously described mutational burden in a much larger cohort of CMT cases, and observed the same effect in HSP cases. We identified a preliminary risk allele for CMT in the EXOC4 gene (p value= 6.9 × 10-6, odds ratio [OR] = 2.1) and explored the possibility of multilocus inheritance in IA. CONCLUSION: Our results support the continuing emergence of complex inheritance mechanisms in historically Mendelian disorders

Female Institutional Directors on Boards and Firm Value

The aim of this research is to examine what impact female institutional directors on boards have on corporate performance. Previous research shows that institutional female directors cannot be considered as a homogeneous group since they represent investors who may or may not maintain business relations with the companies on whose corporate boards they sit. Thus, it is not only the effect of female institutional directors as a whole on firm value that has been analysed, but also the impact of pressure-resistant female directors, who represent institutional investors (investment, pension and mutual funds) that only invest in the company, and do not maintain a business relation with the firm. We hypothesize that there is a non-linear association, specifically quadratic, between institutional and pressure-resistant female directors on boards and corporate performance. Our results report that female institutional directors on boards enhance corporate performance, but when they reach a certain threshold on boards (11.72 %), firm value decreases. In line with female institutional directors, pressure-resistant female directors on boards also increase firm value, but only up to a certain figure (12.71 % on boards), above which they have a negative impact on firm performance. These findings are consistent with an inverted U-shaped relationship between female institutional directors and pressure-resistant female directors and firm performance