Ionization in fast atom-atom collisions: The influence and scaling behavior of electron-electron and electron-nucleus interactions

We report cross sections for ionization of He coincident with electron loss from He, Li, C, O, and Ne projectiles. For He, Li, C, and O projectiles, the cross sections were measured directly, while the Ne cross sections were obtained by transforming results for He projectiles colliding with Ne. We find that, at energies of about 100–500 keV/u, neutral projectiles can ionize a He target almost as effectively as a charged projectile. The contribution to ionization due to electron-electron interactions is found to scale with the number of available projectile electrons. Comparing ionization by the bound electrons on projectiles to ionization by free electrons, we find that the cross sections for ionization by bound electrons are systematically smaller than those for free electrons

Search for exchange-antisymmetric two-photon states

Atomic two-photon J=0 $\leftrightarrow$J'=1 transitions are forbidden for photons of the same energy. This selection rule is related to the fact that photons obey Bose-Einstein statistics. We have searched for small violations of this selection rule by studying transitions in atomic Ba. We set a limit on the probability $v$ that photons are in exchange-antisymmetric states: $v<1.2\cdot10^{-7}$.Comment: 5 pages, 4 figures, ReVTeX and .eps. Submitted to Phys. Rev. Lett. Revised version 9/25/9

Environment and shipping drive environmental DNA beta-diversity among commercial ports

The spread of nonindigenous species by shipping is a large and growing global problem that harms coastal ecosystems and economies and may blur coastal biogeographical patterns. This study coupled eukaryotic environmental DNA (eDNA) metabarcoding with dissimilarity regression to test the hypothesis that ship-borne species spread homogenizes port communities. We first collected and metabarcoded water samples from ports in Europe, Asia, Australia and the Americas. We then calculated community dissimilarities between port pairs and tested for effects of environmental dissimilarity, biogeographical region and four alternative measures of ship-borne species transport risk. We predicted that higher shipping between ports would decrease community dissimilarity, that the effect of shipping would be small compared to that of environment dissimilarity and shared biogeography, and that more complex shipping risk metrics (which account for ballast water and stepping-stone spread) would perform better. Consistent with our hypotheses, community dissimilarities increased significantly with environmental dissimilarity and, to a lesser extent, decreased with ship-borne species transport risks, particularly if the ports had similar environments and stepping-stone risks were considered. Unexpectedly, we found no clear effect of shared biogeography, and that risk metrics incorporating estimates of ballast discharge did not offer more explanatory power than simpler traffic-based risks. Overall, we found that shipping homogenizes eukaryotic communities between ports in predictable ways, which could inform improvements in invasive species policy and management. We demonstrated the usefulness of eDNA metabarcoding and dissimilarity regression for disentangling the drivers of large-scale biodiversity patterns. We conclude by outlining logistical considerations and recommendations for future studies using this approach.Fil: Andrés, Jose. Cornell University. Department Of Ecology And Evolutionary Biology;Fil: Czechowski, Paul. Cornell University. Department Of Ecology And Evolutionary Biology; . University of Otago; Nueva Zelanda. Helmholtz Institute for Metabolic, Obesity and Vascular Research; AlemaniaFil: Grey, Erin. University of Maine; Estados Unidos. Governors State University; Estados UnidosFil: Saebi, Mandana. University of Notre Dame; Estados UnidosFil: Andres, Kara. Cornell University. Department Of Ecology And Evolutionary Biology;Fil: Brown, Christopher. California State University Maritime Academy; Estados UnidosFil: Chawla, Nitesh. University of Notre Dame; Estados UnidosFil: Corbett, James J.. University of Delaware; Estados UnidosFil: Brys, Rein. Research Institute for Nature and Forest; BélgicaFil: Cassey, Phillip. University of Adelaide; AustraliaFil: Correa, Nancy. Ministerio de Defensa. Armada Argentina. Instituto Universitario Naval de la Ara. Escuela de Ciencias del Mar; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; ArgentinaFil: Deveney, Marty R.. South Australian Research And Development Institute; AustraliaFil: Egan, Scott P.. Rice University; Estados UnidosFil: Fisher, Joshua P.. United States Fish and Wildlife Service; Estados UnidosFil: vanden Hooff, Rian. Oregon Department of Environmental Quality; Estados UnidosFil: Knapp, Charles R.. Daniel P. Haerther Center for Conservation and Research; Estados UnidosFil: Leong, Sandric Chee Yew. National University of Singapore; SingapurFil: Neilson, Brian J.. State of Hawaii Division of Aquatic Resources; Estados UnidosFil: Paolucci, Esteban Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pfrender, Michael E.. University of Notre Dame; Estados UnidosFil: Pochardt, Meredith R.. M. Rose Consulting; Estados UnidosFil: Prowse, Thomas A. A.. University of Adelaide; AustraliaFil: Rumrill, Steven S.. Oregon Department of Fish and Wildlife; Estados UnidosFil: Scianni, Chris. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Marine Invasive Species Program; Estados UnidosFil: Sylvester, Francisco. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Tamburri, Mario N.. University of Maryland; Estados UnidosFil: Therriault, Thomas W.. Pacific Biological Station; CanadáFil: Yeo, Darren C. J.. National University of Singapore; SingapurFil: Lodge, David M.. Cornell University. Department Of Ecology And Evolutionary Biology

Effects of acute tryptophan depletion on affective processing in first-degree relatives of depressive patients and controls after exposure to uncontrollable stress

Rationale Individuals with a family history of depression may be more likely to develop depression due to an innate vulnerability of their serotonergic system. However, even though serotonergic vulnerability may constitute a risk factor in the development of depression, it does not seem to be sufficient to cause a depressive episode. Based on previous data, it is suggested that stress may be a mediating factor. Objectives This study examined the role of serotonin (5-HT) in stress coping in individuals with or without a family history of depression. Materials and methods Nineteen healthy first-degree relatives of depressive patients (FH+) and 19 healthy controls without a family history of depression (FH-) were tested in a double-blind placebo-controlled design for affective processing under acute stress exposure, following acute tryptophan depletion (ATD) or placebo. Results Significant negative effects were found of stress on affective processing in FH- and FH+. In addition, FH- responded slower to positive words after stress only following ATD, whereas FH+ responded marginally slower under stress already after placebo and before stress following ATD. Conclusion Acute stress exposure reduces positive affective bias; supporting the role of stress as an important predecessor in the development of depression. Furthermore, FH+ may be more susceptible than FH- to the negative effects of stress as well as to the negative effects of ATD. The results support the assumption that the 5-HT system is involved in stress resilience and may be more vulnerable in first-degree relatives of depression

A method for the isolation of human gastric mucous epithelial cells for primary cell culture: A comparison of biopsy vs surgical tissue

We have developed a method for the isolation and growth of normal human gastric mucous epithelial cells using biopsies or surgically resected tissues as the source of the cells. The attachment and growth of cells were dependent upon: (1) cell planting density, ∼50,000 cells/cm 2 ; (2) extracellular matrix (fibronectin); and (3) and the use of a porous filter. In all experiments we found better cells attachment and growth of human gastric mucous cells isolated from surgical specimens compared with those gastric mucous cells isolated from gastric biopsies. The initial cell viability (as measured by Trypan-blue) was the same in both populations of gastric mucous epithelial cells isolated from either gastric biopsies or surgical specimens. After 4–5 days in culture one could detect various amounts of mucin in all the cells using either periodic acid Schiff (PAS) staining or a specific anti-mucin antibody. A similar pattern of much straining was also found in primary cultures of guinea pig gastric mucous epithelial cells. Immunohistochemical staining for chief cells (anti-pepsinogen) or parietal cells (anti-H + /K + ATPasc) in the gastric mucous cuboidal-like epithelial cells with tight junctions, desmosomes,short microvilli, a filamentous terminal web, mucous granules, and basal lamina-like structure. We could not detect the presence of fibroblasts during the 7–9 days that the primary cells were in culture. This cell culture method will prove useful in the isolation of normal human gastric mucous epithelial cells for in vitro studies of gastric mucosal injury and repair.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43235/1/11022_2004_Article_BF00127904.pd

Use of a conditional Ubr5 mutant allele to investigate the role an N-end rule ubiquitin-protein ligase in Hedgehog signalling and embryonic limb development

Hedgehog (Hh) signalling is a potent regulator of cell fate and function. While much is known about the events within a Hh-stimulated cell, far less is known about the regulation of Hh-ligand production. Drosophila Hyperplastic Discs (Hyd), a ubiquitin-protein ligase, represents one of the few non-transcription factors that independently regulates both hh mRNA expression and pathway activity. Using a murine embryonic stem cell system, we revealed that shRNAi of the mammalian homologue of hyd, Ubr5, effectively prevented retinoic-acid-induced Sonic hedgehog (Shh) expression. We next investigated the UBR5:Hh signalling relationship in vivo by generating and validating a mouse bearing a conditional Ubr5 loss-of-function allele. Conditionally deleting Ubr5 in the early embryonic limb-bud mesenchyme resulted in a transient decrease in Indian hedgehog ligand expression and decreased Hh pathway activity, around E13.5. Although Ubr5-deficient limbs and digits were, on average, shorter than control limbs, the effects were not statistically significant. Hence, while loss of UBR5 perturbed Hedgehog signalling in the developing limb, there were no obvious morphological defects. In summary, we report the first conditional Ubr5 mutant mouse and provide evidence for a role for UBR5 in influencing Hh signalling, but are uncertain to whether the effects on Hedgehog signaling were direct (cell autonomous) or indirect (non-cell-autonomous). Elaboration of the cellular/molecular mechanism(s) involved may help our understanding on diseases and developmental disorders associated with aberrant Hh signalling

The National Early Warning Score and its subcomponents recorded within ±24 hours of emergency medical admission are poor predictors of hospital-acquired acute kidney injury

YesBackground: Hospital-acquired Acute Kidney Injury (H-AKI) is a common cause of avoidable morbidity and mortality. Aim: To determine if the patients’ vital signs data as defined by a National Early Warning Score (NEWS), can predict H-AKI following emergency admission to hospital. Methods: Analyses of emergency admissions to York hospital over 24-months with NEWS data. We report the area under the curve (AUC) for logistic regression models that used the index NEWS (model A0), plus age and sex (A1), plus subcomponents of NEWS (A2) and two-way interactions (A3). Likewise for maximum NEWS (models B0,B1,B2,B3). Results: 4.05% (1361/33608) of emergency admissions had H-AKI. Models using the index NEWS had the lower AUCs (0.59 to 0.68) than models using the maximum NEWS AUCs (0.75 to 0.77). The maximum NEWS model (B3) was more sensitivity than the index NEWS model (A0) (67.60% vs 19.84%) but identified twice as many cases as being at risk of H-AKI (9581 vs 4099) at a NEWS of 5. Conclusions: The index NEWS is a poor predictor of H-AKI. The maximum NEWS is a better predictor but seems unfeasible because it is only knowable in retrospect and is associated with a substantial increase in workload albeit with improved sensitivity.The Health Foundatio

New Benedenia Species (Monogenea: Capsalidae) from Diagramma labiosum (Perciformes: Haemulidae) On the Great Barrier Reef, Australia, With Oncomiracidial Descriptions and A Report of Egg Attachment to the Host

The slate sweetlips, Diagramma labiosum Macleay, 1883 (Perciformes: Haemulidae), off Heron Island, Great Barrier Reef, Queensland, Australia, hosts 2 new species of Benedenia Diesing, 1858 (Monogenea: Monopisthocotylea: Capsalidae). Benedenia beverleyburtonae n. sp. infects proximal regions of the primary gill lamellae and gill arches. The adult is characterized by a dorsal vaginal pore anterior to the common genital pore and a voluminous, highly coiled vas deferens. This species also has fine muscle fibrils concentrically arranged in the haptor. Its ciliated oncomiracidium differs little from larvae of other Benedenia species, with the exception of at least 4 gland cells containing a granular secretion on each side of the body at the level of the excretory bladders, with fine ducts opening anterior to the eyes. Benedenia disciliata n. sp. infects gill arches and gill rakers, and the adult is characterized by its small total length, anterior hamuli with a small proximal notch, posterior hamuli with a broad, triangular shape proximally, a conspicuous internal fertilization chamber, and asymmetrical eggs. None of the 5 specimens collected had testes, but their definite absence is undetermined. Their absence and the fact that the vas deferens was discernable only distally in the specimens of B. disciliata examined may represent atrophying of the male organs. Benedenia disciliata is unique among Benedenia species because eggs are attached to the host's gill arches by tight wrapping of the appendages around spines on the gill rakers and the larva is not ciliated. Among Capsalidae species, these features are shared only with species of Dioncus Goto, 1899. Recent molecular evidence has indicated Benedenia is polyphyletic, but with no clear morphological characters available to divide the genus, the 2 new species fit the current concept for the genus more closely than other capsalid genera. Proposal and description of these taxa and accounts of their oncomiracidia and other aspects of their biology indicate potentially useful characters for division of the genus in the future.Ian D. Whittington and Marty R. Devene