111 research outputs found
Comparative Effects of Chemical and Physical Sunscreen on Fertilization of Purple Sea Urchins (Strongylocentrotus purpuratus)
Organic compound-based “chemical” sunscreens dominate the commercial sunscreen market, but recent research has revealed the ingredients of these products are detrimental to the health of marine organisms. This revelation has led to increased popularity of mineral-based “physical” sunscreens, primarily containing zinc-oxide (ZnO), as environmentally safe alternatives. While they are marketed as environmentally safe, these claims are largely untested, and it is important to consider potential effects of ZnO-based sunscreens on the development of marine organisms. Though Zn is a necessary micronutrient in the ocean, excess Zn is released into marine environments from anthropogenic sources has negative effects on marine life. Many studies have examined effects of various chemical and physical sunscreens separately, but there are no published studies comparing them directly. In this study, we document effects of oxybenzone based “chemical” sunscreen versus zinc-oxide based “physical” sunscreen on fertilization of the purple sea urchin, Strongylocentrotus purpuratus. We demonstrate that exposure of gametes to chemical sunscreen has a significantly more detrimental effect on fertilization success than exposure to a physical sunscreen at low concentrations, and that the physical sunscreen is slightly more detrimental to ova at higher concentrations than the chemical sunscreen. We also observed decreases in fertilization success when both gametes were exposed to either sunscreen, indicating an additive effect. While both sunscreens appear harmful to the development of marine organisms, our results from exposing gametes to the lower, more environmentally relevant levels of sunscreens, suggest that physical sunscreen may be less harmful than chemical sunscreen to sea urchin gametes
Effects of Bisphenol-A and Styrene on Fertilization and Development of the Purple Sea Urchin (Strongylocentrotus purpuratus)
Plastic waste and debris have greatly increased in the marine environment during the past 50 years. Not only do these plastics entangle and get ingested by marine mammals, turtles, and sea birds, but they also leach chemicals, such as bisphenol-A (BPA) and styrene into the aquatic environment. While some of these chemicals are known to be toxic, few studies have examined their effects on broadcast spawning marine invertebrates, specifically at environmentally relevant concentrations. Purple sea urchins, Strongylocentrotus purpuratus, from the central coast of California, were utilized to examine effects of BPA and styrene on fertilization success and early development of resulting embryos. Previous research has demonstrated that BPA and styrene decrease successful fertilization and delay development of sea urchins, though no previous studies have examined effects of continuous chemical treatment on S. purpuratus development. We exposed eggs, sperm, or both to environmentally relevant concentrations of BPA or styrene (100 µg/L, 500 µg/L, and 1000 µg/L) to test the hypothesis that continuous treatment would lead to developmental abnormalities. The greatest effect was observed in pluteus larvae development, as the percentage of normal embryos decreased by as much as 80% in high dose chemical treatments (p
Factors Influencing Spatial Variability in Nitrogen Processing in Nitrogen-Saturated Soils
Nitrogen (N) saturation is an environmental concern for forests in the eastern U.S. Although several watersheds of the Fernow Experimental Forest (FEF), West Virginia exhibit symptoms of Nsaturation, many watersheds display a high degree of spatial variability in soil N processing. This study examined the effects of temperature on net N mineralization and nitrification in N-saturatedsoils from FEF, and how these effects varied between high N-processing vs. low N-processingsoils collected from two watersheds, WS3 (fertilized with [NH4]2SO4) and WS4 (untreated control). Samples of forest floor material (O2 horizon) and mineral soil (to a 5-cm depth) were taken from three subplots within each of four plots that represented the extremes of highest and lowest ratesof net N mineralization and nitrification (hereafter, high N and low N, respectively) of untreated WS4 and N-treated WS3: control/low N, control/high N, N-treated/low N, N-treated/high N. Forest floor material was analyzed for carbon (C), lignin,and N. Subsamples of mineral soil were extractedimmediately with 1 N KCl and analyzed for NH4+and NO3– to determine preincubation levels. Extracts were also analyzed for Mg, Ca, Al, and pH. To test the hypothesis that the lack of net nitrification observed in field incubations on the untreated/low N plot was the result of absence ofnitrifier populations, we characterized the bacterial community involved in N cycling by amplification of amoA genes. Remaining soil was incubated for 28 d at three temperatures (10, 20, and30°C), followed by 1 N KCl extraction and analysis for NH4+ and NO3–. Net nitrification was essentially 100% of net N mineralization for all samples combined. Nitrification rates from lab incubation sat all temperatures supported earlier observations based on field incubations. At 30°C, rates from N- t reated/high N were three times those of N-treated/low N. Highest rates were found for untreated/high N (two times greater than those of N-treated/high N), whereas untreated/low N exhibited no net nitrification. However, soils exhibitingno net nitrification tested positive for presence of nitrifying bacteria, causing us to reject our initial hypothesis. We hypothesize that nitrifier populations in such soil are being inhibited by a combination of low Ca:Al ratios in mineral soil and allelopathic interactions with mycorrhizae of ericaceous species in the herbaceous layer
The Grizzly, February 27, 1987
Depts., Dean, Court New Faculty Free Agent Team • No Busts, But Bummer Booze Bar Dims Lorelei • Grizzly Poll Points Couple to Final Home • Letters: Impossible Crossings?; Adoption Instead of Abortion; Plea for Soviet Jewry • Ecoliers de Francais: Fly to France Pour Parler • Treasuring Modern Art Takes Time ... And Protest • Men\u27s B-Ball Sponsors Art Auction • Fencing Alive at Ursinus • Bears, 20-3, Looking for Fourth or Better at MAC • Swimmers to Celebrate Wins With Skins • Women Runners Capture MAC Title • Men\u27s Track Runs Third at MAC\u27s • Swimmin\u27 Women Go to MAC\u27s • Notes: Meistersingers\u27 50th Tour; Chambliss Family Lecture; Upcoming Forum Scheduled • Bear Dave Durst Dominates Entering MAC Tourney • Migliore Caps Nine-Letter Career with Athlete of the Week Honors • Two U.C. Gymnasts Go to Nat\u27ls • Robert Cray Band\u27s Strong Persuader Receives a B plushttps://digitalcommons.ursinus.edu/grizzlynews/1183/thumbnail.jp
The genomic repertoire for cell cycle control and DNA metabolism in S. purpuratus
A search of the Strongylocentrotus purpuratus genome for genes associated with cell cycle control and DNA metabolism shows that the known repertoire of these genes is conserved in the sea urchin, although with fewer family members represented than in vertebrates, and with some cases of echinoderm-specific gene diversifications. For example, while homologues of the known cyclins are mostly encoded by single genes in S. purpuratus (unlike vertebrates, which have multiple isoforms), there are additional genes encoding novel cyclins of the B and K/L types. Almost all known cyclin-dependent kinases (CDKs) or CDK-like proteins have an orthologue in S. purpuratus; CDK3 is one exception, whereas CDK4 and 6 are represented by a single homologue, referred to as CDK4. While the complexity of the two families of mitotic kinases, Polo and Aurora, is close to that found in the nematode, the diversity of the NIMA-related kinases (NEK proteins) approaches that of vertebrates. Among the nine NEK proteins found in S. purpuratus, eight could be assigned orthologues in vertebrates, whereas the ninth is unique to sea urchins. Most known DNA replication, DNA repair and mitotic checkpoint genes are also present, as are homologues of the pRB (two) and p53 (one) tumor suppressors. Interestingly, the p21/p27 family of CDK inhibitors is represented by one homologue, whereas the INK4 and ARF families of tumor suppressors appear to be absent, suggesting that these evolved only in vertebrates. Our results suggest that, while the cell cycle control mechanisms known from other animals are generally conserved in sea urchin, parts of the machinery have diversified within the echinoderm lineage. The set of genes uncovered in this analysis of the S. purpuratus genome should enhance future research on cell cycle control and developmental regulation in this model
Detection of the florfenicol resistance gene floR in Chryseobacterium isolates from rainbow trout. Exception to the general rule?
Bacteria from the family Flavobacteriaceae often show low susceptibility to antibiotics. With the exception of two Chryseobacterium spp. isolates that were positive for the florfenicol resistance gene floR, no clinical resistance genes were identified by microarray in 36 Flavobacteriaceae isolates from salmonid fish that could grow in ≥ 4 mg/L florfenicol. Whole genome sequence analysis of the floR positive isolates revealed the presence of a region that contained the antimicrobial resistance genes floR, a tet(X) tetracycline resistance gene, a streptothricin resistance gene and a chloramphenicol acetyltransferase gene. In silico analysis of 377 published genomes for Flavobacteriaceae isolates from a range of sources confirmed that well-characterised resistance gene cassettes were not widely distributed in bacteria from this group. Efflux pump-mediated decreased susceptibility to a range of antimicrobials was confirmed in both floR positive isolates using an efflux pump inhibitor (phenylalanine-arginine β-naphthylamide) assay. The floR isolates possessed putative virulence factors, including production of siderophores and haemolysins, and were mildly pathogenic in rainbow trout. Results support the suggestion that, despite the detection of floR, susceptibility to antimicrobials in Flavobacteriaceae is mostly mediated via intrinsic mechanisms rather than the horizontally acquired resistance genes more normally associated with Gram-negative bacterial pathogens such as Enterobacteriaceae
Nuclear receptor binding protein 1 regulates intestinal progenitor cell homeostasis and tumour formation.
Genetic screens in simple model organisms have identified many of the key components of the conserved signal transduction pathways that are oncogenic when misregulated. Here, we identify H37N21.1 as a gene that regulates vulval induction in let-60(n1046gf), a strain with a gain-of-function mutation in the Caenorhabditis elegans Ras orthologue, and show that somatic deletion of Nrbp1, the mouse orthologue of this gene, results in an intestinal progenitor cell phenotype that leads to profound changes in the proliferation and differentiation of all intestinal cell lineages. We show that Nrbp1 interacts with key components of the ubiquitination machinery and that loss of Nrbp1 in the intestine results in the accumulation of Sall4, a key mediator of stem cell fate, and of Tsc22d2. We also reveal that somatic loss of Nrbp1 results in tumourigenesis, with haematological and intestinal tumours predominating, and that nuclear receptor binding protein 1 (NRBP1) is downregulated in a range of human tumours, where low expression correlates with a poor prognosis. Thus NRBP1 is a conserved regulator of cell fate, that plays an important role in tumour suppression
“It's Just Presence,” the Contributions of Aboriginal and Torres Strait Islander Health Professionals in Cancer Care in Queensland
Objectives: The aim of this research was to explore health professionals' perspectives on the provision of follow-up cancer care for Aboriginal and Torres Strait Islander patients in Queensland.Methods: Semi-structured interviews were conducted with Indigenous and non-Indigenous health professionals who had experience providing care for Indigenous cancer patients in the primary health care and hospital setting.Results: Participants were recruited from six Aboriginal Community Controlled Health Services (n = 17) and from a tertiary hospital (n = 9) across urban, regional, and remote geographical settings. Culturally safe care, psychological support, determining patient needs, practical assistance, and advocating for Indigenous health were identified as enablers to support the needs of Indigenous patients when accessing cancer care, and Indigenous health professionals were identified as the key enabler.Conclusion: Indigenous health professionals significantly contribute to the provision of culturally competent follow-up cancer care by increasing the accessibility of follow-up cancer care services and by supporting the needs of Indigenous cancer patients. All health professionals need to work together and be sufficiently skilled in the delivery of culturally competent care to improve the Indigenous cancer journey and outcomes for Indigenous people. Effective organizational policies and practices are crucial to enable all health professionals to provide culturally competent and responsive cancer care to Indigenous Australians
Disparities in dialysis treatment and outcomes for Dutch and Belgian children with immigrant parents
BACKGROUND: In Belgium and the Netherlands, up to 40% of the children on dialysis are children with immigrant parents of non-Western European origin (non-Western). Concerns exist regarding whether these non-Western patients receive the same quality of care as children with parents of Western European origin (Western). We compared initial dialysis, post-initial treatment, and outcomes between non-Western and Western patients on dialysis. METHODS: All children <19 years old on chronic dialysis in the Netherlands and Belgium between September 2007 and May 2011 were included in the study. Non-Western patients were defined as children of whom one or both parents were born in non-Western countries. RESULTS: Seventy-nine of the 179 included patients (44%) were non-Western children. Compared to Western patients, non-Western patients more often were treated with hemodialysis (HD) instead of peritoneal dialysis (PD) as first dialysis mode (52 vs. 37%, p = 0.046). Before renal transplantation, non-Western patients were on dialysis for a median (range) of 30 (5-99) months, vs. 15 (0-66) months in Western patients (p = 0.007). Renal osteodystrophy was diagnosed in 34% of non-Western vs. 18% of Western patients (p = 0.028). The incidence rate ratio [95% confidence interval] for acute peritonitis was 2.44 [1.43-4.17] (p = 0.032) for non-Western compared to Western patients. CONCLUSIONS: There are important disparities between children on chronic dialysis with parents from Western European origin and those from non-Western European origin in the choice of modality, duration, and outcomes of dialysis therapy
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