105 research outputs found

    Alien Registration- Sewell, Mary A. (Millinocket, Penobscot County)

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    https://digitalmaine.com/alien_docs/7721/thumbnail.jp

    Temperature and salinity tolerances of Stage 1 zoeae predict possible range expansion of an introduced portunid crab, Charybdis japonica, in New Zealand

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    The successful invasion of a non-native species depends on several factors, including initial colonization and establishment of a self-sustaining population. Populations of the non-native paddle crab Charybdis japonica were first recognized in the Waitemata Harbour, Auckland, New Zealand in 2000, most likely arriving in ballast waters of an Asian merchant vessel. A survey completed in 2003 found C. japonica throughout the Waitemata Harbour, and further sampling in 2009 has revealed several well established populations in estuaries up to 70 km from the putative invasion point. As the potential for further establishment of C. japonica beyond this area may depend on the temperature and salinity tolerances of their free swimming larvae, we quantified the survival of newly-hatched Stage 1 C. japonica zoeae subjected to temperatures ranging from 11 to 43°C or salinities from 5 to 45‰ in the laboratory. Upon hatching, replicate C. japonica zoeae were directly transferred from 21°C and 34.6‰ seawater to either an experimental temperature or salinity level. Behaviour and death rates of the larvae were monitored over a 24 h period in the absence of food. Comparisons of zoeal survival rates to historical sea surface temperatures and salinities show that C. japonica Stage 1 zoeae tolerate a broad range of temperatures and salinities and could survive natural conditions throughout New Zealand. This gives C. japonica the potential to invade many other New Zealand estuaries and harbours

    The state of the science of nurse work environments in the United States: A systematic review

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    A healthy nurse work environment is a workplace that is safe, empowering, and satisfying. Many research studies were conducted on nurse work environments in the last decade; however, it lacks an overview of these research studies. The purpose of this review is to identify, evaluate, and summarize the major foci of studies about nurse work environments in the United States published between January 2005 and December 2017 and provide strategies to improve nurse work environments. Databases searched included MEDLINE via PubMed, CINAHL, PsycINFO, Nursing and Allied Health, and the Cochrane Library. The literature search followed the PRISMA guideline. Fifty-four articles were reviewed. Five major themes emerged: 1) Impacts of healthy work environments on nurses' outcomes such as psy- chological health, emotional strains, job satisfaction, and retention; 2) Associations between healthy work environments and nurse interpersonal relationships at workplaces, job performance, and pro- ductivity; 3) Effects of healthy work environments on patient care quality; 4) Influences of healthy work environments on hospital accidental safety; and 5) Relationships between nurse leadership and healthy work environments. This review shows that nurses, as frontline patient care providers, are the foun- dation for patient safety and care quality. Promoting nurse empowerment, engagement, and interper- sonal relationships at work is rudimental to achieve a healthy work environment and quality patient care. Healthier work environments lead to more satisfied nurses who will result in better job perfor- mance and higher quality of patient care, which will subsequently improve healthcare organizations' financial viability. Fostering a healthy work environment is a continuous effort

    Rotavirus NSP4 is secreted from infected cells as an oligomeric lipoprotein and binds to glycosaminoglycans on the surface of non-infected cells

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    <p>Abstract</p> <p>Background</p> <p>Nonstructural glycoprotein 4 (NSP4) encoded by rotavirus is the only viral protein currently believed to function as an enterotoxin. NSP4 is synthesized as an intracellular transmembrane glycoprotein and as such is essential for virus assembly. Infection of polarized Caco-2 cells with rotavirus also results in the secretion of glycosylated NSP4 apparently in a soluble form despite retention of its transmembrane domain. We have examined the structure, solubility and cell-binding properties of this secreted form of NSP4 to further understand the biochemical basis for its enterotoxic function. We show here that NSP4 is secreted as discrete detergent-sensitive oligomers in a complex with phospholipids and demonstrate that this secreted form of NSP4 can bind to glycosaminoglycans present on the surface of a range of different cell types.</p> <p>Methods</p> <p>NSP4 was purified from the medium of infected cells after ultracentrifugation and ultrafiltration by successive lectin-affinity and ion exchange chromatography. Oligomerisation of NSP4 was examined by density gradient centrifugation and chemical crosslinking and the lipid content was assessed by analytical thin layer chromatography and flame ionization detection. Binding of NSP4 to various cell lines was measured using a flow cytometric-based assay.</p> <p>Results</p> <p>Secreted NSP4 formed oligomers that contained phospholipid but dissociated to a dimeric species in the presence of non-ionic detergent. The purified glycoprotein binds to the surface of various non-infected cells of distinct lineage. Binding of NSP4 to HT-29, a cell line of intestinal origin, is saturable and independent of divalent cations. Complementary biochemical approaches reveal that NSP4 binds to sulfated glycosaminoglycans on the plasma membrane.</p> <p>Conclusion</p> <p>Our study is the first to analyze an authentic (i.e. non-recombinant) form of NSP4 that is secreted from virus-infected cells. Despite retention of the transmembrane domain, secreted NSP4 remains soluble in an aqueous environment as an oligomeric lipoprotein that can bind to various cell types via an interaction with glycosaminoglycans. This broad cellular tropism exhibited by NSP4 may have implications for the pathophysiology of rotavirus disease.</p

    Description and ecophysiology of a new species of Syndesmis Silliman, 1881 (Rhabdocoela: Umagillidae) from the sea urchin Evechinus chloroticus (Valenciennes, 1846) Mortensen, 1943 in New Zealand

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    A new rhabdocoel of the genus Syndesmis Silliman, 1881 (Umagillidae) is described from the intestine of the New Zealand sea urchin Evechinus chloroticus (Valenciennes, 1846) Mortensen, 1943a. This new species, Syndesmis kurakaikina n. sp., is morphologically distinct and can easily be recognised by its very long (+/- 1 mm) styles and its bright-red colour. In addition to providing a formal description, we present some observations on reproduction and life history of this new species. Fecundity is comparable to that of other umagillids and the rate of egg production and development increases with temperature. Hatching in this species is induced by intestinal fluids of its host. Relevant to global warming, we assessed the effect of temperature on survival, fecundity, and development. The tests indicate that Syndesmis kurakaikina n. sp. is tolerant of a wide range of temperatures (11-25 degrees C) and that its temperature optimum lies between 18.0 and 21.5 degrees C. Egg viability is, however, significantly compromised at the higher end of this temperature range, with expelled egg capsules often being deformed and showing increasingly lower rates of hatching. Given this, a rise in global temperature might increase the risk of Syndesmis kurakaikina n. sp. infecting new hosts and would possibly facilitate the spread of these endosymbionts.Peer reviewe

    Sex and reproductive cycle affect lipid and fatty acid profiles of gonads of Arbacia dufresnii (Echinodermata: Echinoidea)

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    Analysis of the lipid composition of gonads allows differentiation between energy and structural lipids, which is important for understanding lipid utilization during gametogenesis. Fatty acids, which are frequently used as biomarkers in trophic ecology studies, are also a useful companion to lipid studies and provide a detailed understanding of a species' reproductive cycle. We examined the influence of sex and the reproductive cycle on the lipid and fatty acid profiles of gonads in the sea urchin Arbacia dufresnii. In a population from Nuevo Gulf, Argentina, we found significant changes in total lipid concentration, lipid profile and fatty acid profile throughout the reproductive cycle. Ovaries and testes containing fully mature gametes differed in total lipid concentration (higher in the ovaries), lipid profile (more energy lipids in ovaries and more structural lipids in testes) and fatty acid profile (differed by sex, not only in the variety of fatty acids present but in the degree of unsaturation). Our results show that differences in lipid and fatty acid profiles caused by sex and gonadal reproductive stage need to be considered when these tools are used as biomarkers in ecological studies.Fil: Zárate, Erica. The University of Auckland; Nueva ZelandaFil: Díaz de Vivar, María Enriqueta Adela. Universidad Nacional de la Patagonia; ArgentinaFil: Avaro, Marisa Gladis. Universidad Nacional de la Patagonia; ArgentinaFil: Epherra, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Sewell, Mary A.. The University of Auckland; Nueva Zeland

    Can we predict ectotherm responses to climate change using thermal performance curves and body temperatures?

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    Thermal performance curves (TPCs), which quantify how an ectotherm\u27s body temperature (Tb ) affects its performance or fitness, are often used in an attempt to predict organismal responses to climate change. Here, we examine the key - but often biologically unreasonable - assumptions underlying this approach; for example, that physiology and thermal regimes are invariant over ontogeny, space and time, and also that TPCs are independent of previously experienced Tb. We show how a critical consideration of these assumptions can lead to biologically useful hypotheses and experimental designs. For example, rather than assuming that TPCs are fixed during ontogeny, one can measure TPCs for each major life stage and incorporate these into stage-specific ecological models to reveal the life stage most likely to be vulnerable to climate change. Our overall goal is to explicitly examine the assumptions underlying the integration of TPCs with Tb , to develop a framework within which empiricists can place their work within these limitations, and to facilitate the application of thermal physiology to understanding the biological implications of climate change
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