A Comparison of Vegetation in Restored and Natural Wetlands in the Nebraska Sandhills.

Plant composition was compared between 3 restored and 3 natural Nebraska sandhill wetlands using plot data collected from each wetland in July and August of 1995 along five randomly placed, 25m transects. A total of 126 species were identified, of which 72 were found only in the natural area and 23 only in the restored area; the natural wetlands average 58 species and their restored 31. Cluster analysis of mean cover values, at a Euclidean Distance of 1000, identified five vegetative associations in the natural and three in the restored wetlands. In addition, cluster analysis of combined data indicated a complete separation of the restored and natural wetlands. Ordination of combined data showed a tight clustering of the restored area plots midway along the X-axis (xeric-hydric gradient; Eigenvalue 0.78) suggesting that the restored area represents only a portion of the total gradient of the natural area. Three Basic patterns of species distribution were identified based on the natural area data. Type I species distributions were characterized by Scirpus acutus which increased in canopy cover from being absent in the xeric upland to 18% cover in the hydric lowland. This species, however, was ubiquitous throughout the restored area averaging 2% cover. Eleocharis erythropoda characterized Type II species are both natural and restored wetlands with the highest canopy in central plots of the natural area transect (26%) and even higher (55%) in the restored area. Dichanthelium acuminatum var. implicatum typified Type III Species with a decrease in cover from xeric (11%) to absent in the hydric sites. Type III species were either absent. ANOVA and Sudent-Newman-Keuls multi comparison test of species with a frequency of at least 10% showed significant differences (p\u3c0.05) among at least two or three restored or natural wetland plots for Agrostis stolonifera, Amberosia psilostachya, Elecharis acicularis, Eleocharis erythropoda, Eleocharis palustris, Lysicmachia ciliate, Lythrum alatum, Scripus acutus, Spartina pectinate, Suim suave, and Typha spp.. Based on community-level and species level analyses, the present study suggests that the restored Sandhill wetlands evaluated are not, presently, similar to natural wetlands and that it would be premature to suggest that the restorations are successful. Further, the results of this study suggest that serious wetland restoration efforts must ensure that basic abiotic (e.g. topographic) heterogeneity is provided in restoration sites. The difficulties, and probable costs, involve in ensuring successful wetland restoration should invite more serious efforts to prevent destruction of habitat

School of Pharmacy, a history

Since the beginnings of the Medical College of Virginia (MCV), the School of Pharmacy at Virginia Commonwealth University has been a leader in pharmacy education. This book traces the history of the School of Pharmacy up to the time of its publication in 1988. Topics covered include the merging of MCV and University College of Medicine, the development of bachelors, masters and doctoral programs, changes in curriculum along with advances in the field, and the history of the school’s facilities.https://scholarscompass.vcu.edu/vcu_books/1014/thumbnail.jp

Notch Simultaneously Orchestrates Multiple Helper T Cell Programs Independently of Cytokine Signals

SummaryTwo models are proposed to explain Notch function during helper T (Th) cell differentiation. One argues that Notch instructs one Th cell fate over the other, whereas the other posits that Notch function is dictated by cytokines. Here we provide a detailed mechanistic study investigating the role of Notch in orchestrating Th cell differentiation. Notch neither instructed Th cell differentiation nor did cytokines direct Notch activity, but instead, Notch simultaneously regulated the Th1, Th2, and Th17 cell genetic programs independently of cytokine signals. In addition to regulating these programs in both polarized and nonpolarized Th cells, we identified Ifng as a direct Notch target. Notch bound the Ifng CNS-22 enhancer, where it synergized with Tbet at the promoter. Thus, Notch acts as an unbiased amplifier of Th cell differentiation. Our data provide a paradigm for Notch in hematopoiesis, with Notch simultaneously orchestrating multiple lineage programs, rather than restricting alternate outcomes

A survey of parental self-efficacy experiences: maximising potential through health visiting and universal parenting support

Aims: To examine parental self-efficacy experiences for users of a parenting support programme and consider the pertinence of self-efficacy theory to health visiting (public health nursing) practice. Background: Commonly, successful parenting training programmes are underpinned by social learning principles and aim to strengthen parental self-efficacy. However, research examining programme effectiveness rarely discusses how self-efficacy outcomes are achieved. Design: A descriptive survey was completed as the first part of a realistic evaluation study examining how a UK parenting support programme worked. Method: The first part of the realistic evaluation involved validating outcome measures (the Parenting Self-Agency Measure and Self-Efficacy for Parenting Tasks Index subscales) and administering a questionnaire survey. The questionnaire was completed by adults accessing a parenting support programme during a 10-month period (n = 168). Data were analysed using descriptive and inferential statistics. Results. Women were the main users of the programme, which included informal drop-in groups as well as more formalised health visiting services and parenting training courses. The Parenting Self-Agency Measure results indicated good general parental self-efficacy; however, the task-specific Self-Efficacy for Parenting Tasks Indexes scales suggested that parents were less self-efficacious in disciplining children. Lower self-efficacy scores correlated with high ratings for ‘feeling tired’, ‘receiving negative comments’ and ‘giving-in to a child’s demands’. Conclusions: Study results indicate that the domain general and task-specific measures provide different, but helpful, insights into parental self-efficacy experiences. By identifying factors associated with the levels of general and task-specific parental self-efficacy, health visitors can gain a fuller appreciation of support needs. Relevance to practice: To maximise potential through parenting support, attention should be given to addressing factors associated with poorer self-efficacy experiences, including parental tiredness. Equally, practice should be directed at developing community environments that offer exposure to positive praise and the opportunity to practice new skills without facing criticism

Young Stars and Protostellar Cores near NGC 2023

We investigate the young (proto)stellar population in NGC 2023 and the L 1630 molecular cloud bordering the HII region IC 434, using Spitzer IRAC and MIPS archive data, JCMT SCUBA imaging and spectroscopy as well as targeted BIMA observations of one of the Class 0 protostars, NGC 2023 MM1. We have performed photometry of all IRAC and MIPS images, and used color-color diagrams to identify and classify all young stars seen within a 22'x26' field along the boundary between IC 434 and L 1630. For some stars, which have sufficient optical, IR, and/or sub-millimeter data we have also used the online SED fitting tool for a large 2D archive of axisymmetric radiative transfer models to perform more detailed modeling of the observed SEDs. We identify 5 sub-millimeter cores in our 850 and 450 micron SCUBA images, two of which have embedded class 0 or I protostars. Observations with BIMA are used to refine the position and characteristics of the Class 0 source NGC 2023 MM 1. These observations show that it is embedded in a very cold cloud core, which is strongly enhanced in NH2D. We find that HD 37903 is the most massive member of a cluster with 20 -- 30 PMS stars. We also find smaller groups of PMS stars formed from the Horsehead nebula and another elephant trunk structure to the north of the Horsehead. We refine the spectral classification of HD 37903 to B2 Ve. Our study shows that the expansion of the IC 434 HII region has triggered star formation in some of the dense elephant trunk structures and compressed gas inside the L 1630 molecular cloud. This pre-shock region is seen as a sub-millimeter ridge in which stars have already formed. The cluster associated with NGC 2023 is very young, and has a large fraction of Class I sources.Comment: 21 pages, 11 figures. Accepted for publication in A&A Replaced with higher resolution figure

The hydrodynamics of the supernova remnant Cas A: The influence of the progenitor evolution on the velocity structure and clumping

There are large differences in the proposed progenitor models for the Cas A SNR. One of these differences is the presence or absence of a Wolf-Rayet (WR) phase of the progenitor star. The mass loss history of the progenitor star strongly affects the shape of the Supernova remnant (SNR). In this paper we investigate whether the progenitor star of Cas A had a WR phase or not and how long it may have lasted. We performed two-dimensional multi-species hydrodynamical simulations of the CSM around the progenitor star for several WR life times, each followed by the interaction of the supernova ejecta with the CSM. We then looked at the influence of the length of the WR phase and compared the results of the simulations with the observations of Cas A. The difference in the structure of the CSM, for models with different WR life times, has a strong impact on the resulting SNR. With an increasing WR life time the reverse shock velocity of the SNR decreases and the range of observed velocities in the shocked material increases. Furthermore, if a WR phase occurs, the remainders of the WR shell will be visible in the resulting SNR. Comparing our results with the observations suggests that the progenitor star of Cas A did not have a WR phase. We also find that the quasi-stationary flocculi (QSF) in Cas A are not consistent with the clumps from a WR shell that have been shocked and accelerated by the interaction with the SN ejecta. We can also conclude that for a SN explosion taking place in a CSM that is shaped by the wind during a short < 15000 yr WR phase, the clumps from the WR shell will be visible inside the SNR.Comment: 11 figures, 11 pages, accepted for publication in A&

The Far Ultraviolet Spectral Signatures of Formaldehyde and Carbon Dioxide in Comets

Observations of four comets made with the Far Ultraviolet Spectroscopic Explorer show the rotational envelope of the (0,0) band of the CO Hopfield-Birge system (C - X) at 1088 A to consist of both "cold" and "hot" components, the "cold" component accounting for ~75% of the flux and with a rotational temperature in the range 55-75 K. We identify the "hot" component as coming from the dissociation of CO2 into rotationally "hot" CO, with electron impact dissociation probably dominant over photodissociation near the nucleus. An additional weak, broad satellite band is seen centered near the position of the P(40) line that we attribute to CO fluorescence from a non-thermal high J rotational population produced by photodissociation of formaldehyde into CO and H2. This process also leaves the H2 preferentially populated in excited vibrational levels which are identified by fluorescent H2 lines in the spectrum excited by solar OVI 1031.9 and solar Lyman-alpha. The amount of H2 produced by H2CO dissociation is comparable to the amount produced by photodissociation of H2O. Electron impact excitation of CO, rather than resonance fluorescence, appears to be the primary source of the observed (B - X) (0,0) band at 1151 A.Comment: 21 pages, 7 figures, accepted for publication in the Astrophysical Journa

Stars and brown dwarfs in the sigma Orionis cluster: the Mayrit catalogue

The young sigma Orionis cluster is an indispensable basis for understanding the formation and evolution of stars, brown dwarfs and planetary-mass objects. Our knowledge of its stellar population is, however, incomplete. I present the Mayrit catalogue, that comprises most of the stars and high-mass brown dwarfs of the cluster. The basis of this work is an optical-near infrared correlation between the 2MASS and DENIS catalogues in a circular area of radius 30 arcmin centred on the OB-type binary sigma Ori AB. The analysis is supported on a bibliographic search of confirmed cluster members with features of youth and on additional X-ray, mid-infrared and astrometric data. I list 241 sigma Orionis stars and brown dwarfs with known features of youth, 97 candidate cluster members (40 are new) and 115 back- and foreground sources in the survey area. The 338 cluster members and member candidates constitute the Mayrit catalogue. This catalogue is a suitable input for studying the spatial ditribution, multiplicity, properties and frequency of discs and the complete mass function of sigma Orionis.Comment: accepted for publication in A&A, section 14. Online catalogs and dat

Diffuse Hard X-ray Emission in Starburst Galaxies as Synchrotron from Very High Energy Electrons

[Abdriged] The origin of the diffuse hard X-ray (2 - 10 keV) emission from starburst galaxies is a long-standing problem. We suggest that synchrotron emission of 10 - 100 TeV electrons and positrons (e+/-) can contribute to this emission, because starbursts have strong magnetic fields. We consider three sources of e+/- at these energies: (1) primary electrons directly accelerated by supernova remnants; (2) pionic secondary e+/- created by inelastic collisions between CR protons and gas nuclei in the dense ISMs of starbursts; (3) pair e+/- produced between the interactions between 10 - 100 TeV gamma-rays and the intense far-infrared (FIR) radiation fields of starbursts. We create one-zone steady-state models of the CR population in the Galactic Center (R <= 112 pc), NGC 253, M82, and Arp 220's nuclei, assuming a power law injection spectrum for electrons and protons. We compare these models to extant radio and GeV and TeV gamma-ray data for these starbursts, and calculate the diffuse synchrotron X-ray and Inverse Compton (IC) luminosities of these starbursts. If the primary electron spectrum extends to ~PeV energies and has a proton/electron injection ratio similar to the Galactic value, we find that synchrotron contributes 2 - 20% of their unresolved, diffuse hard X-ray emission. Inverse Compton emission is likewise a minority of the unresolved X-ray emission in these starbursts, from 0.1% in the Galactic Center to 10% in Arp 220's nuclei. We also model generic starbursts, including submillimeter galaxies, in the context of the FIR--X-ray relation, finding that up to 2% in the densest starbursts with our fiducial assumptions. Neutrino and TeV gamma-ray data can further constrain the synchrotron X-ray emission of starbursts. Our models do not constrain hard synchrotron X-ray emission from any additional hard components of primary e+/- from sources like pulsars in starbursts.Comment: Accepted by ApJ; 31 pages, emulateapj forma