132 research outputs found

    Insights into antimicrobial resistance among long distance migratory East Canadian High Arctic light-bellied Brent geese (Branta bernicla hrota)

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    This is the final version of the article. Available from BioMed Central via the DOI in this record.BACKGROUND: Antimicrobial resistance (AMR) is the most significant threat to global public health and ascertaining the role wild birds play in the epidemiology of resistance is critically important. This study investigated the prevalence of AMR Gram-negative bacteria among long-distance migratory East Canadian High Arctic (ECHA) light-bellied Brent geese found wintering on the east coast of Ireland. FINDINGS: In this study a number of bacterial species were isolated from cloacal swabs taken from ECHA light-bellied Brent geese. Nucleotide sequence analysis identified five species of Gram-negative bacteria; the dominant isolated species were Pantoea spp. (n = 5) followed by Buttiauxella agrestis (n = 2). Antimicrobial susceptibility disk diffusion results identified four of the Pantoea spp. strains, and one of the Buttiauxella agrestis strains resistant to amoxicillin-clavulanic acid. CONCLUSION: To our knowledge this is the first record of AMR bacteria isolated from long distance migratory ECHA light-bellied Brent geese. This indicates that this species may act as reservoirs and potential disseminators of resistance genes into remote natural ecosystems across their migratory range. This population of geese frequently forage (and defecate) on public amenity areas during the winter months presenting a potential human health risk.SB is funded by a European Research Councils consolidators grant (STATEMIG: 310820)

    Costs of insensitive acetylcholinesterase insecticide resistance for the malaria vector Anopheles gambiae homozygous for the G119S mutation

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    <p>Abstract</p> <p>Background</p> <p>The G119S mutation responsible for insensitive acetylcholinesterase resistance to organophosphate and carbamate insecticides has recently been reported from natural populations of <it>Anopheles gambiae </it>in West Africa. These reports suggest there are costs of resistance associated with this mutation for <it>An. gambiae</it>, especially for homozygous individuals, and these costs could be influential in determining the frequency of carbamate resistance in these populations.</p> <p>Methods</p> <p>Life-history traits of the AcerKis and Kisumu strains of <it>An. gambiae </it>were compared following the manipulation of larval food availability in three separate experiments conducted in an insecticide-free laboratory environment. These two strains share the same genetic background, but differ in being homozygous for the presence or absence of the G119S mutation at the <it>ace-1 </it>locus, respectively.</p> <p>Results</p> <p>Pupae of the resistant strain were significantly more likely to die during pupation than those of the susceptible strain. Ages at pupation were significantly earlier for the resistant strain and their dry starved weights were significantly lighter; this difference in weight remained when the two strains were matched for ages at pupation.</p> <p>Conclusions</p> <p>The main cost of resistance found for <it>An. gambiae </it>mosquitoes homozygous for the G119S mutation was that they were significantly more likely to die during pupation than their susceptible counterparts, and they did so across a range of larval food conditions. Comparing the frequency of G119S in fourth instar larvae and adults emerging from the same populations would provide a way to test whether this cost of resistance is being expressed in natural populations of <it>An. gambiae </it>and influencing the dynamics of this resistance mutation.</p

    Using mineral chemistry to aid exploration: a case study from the resolution porphyry Cu-Mo deposit, Arizona

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    The giant, high-grade Resolution porphyry Cu-Mo deposit in the Superior district of Arizona is hosted in Proterozoic and Paleozoic basement and in an overlying Cretaceous volcaniclastic breccia and sandstone package. Resolution has a central domain of potassic alteration that extends more than 1 km outboard of the ore zone, overlapping with a propylitic halo characterized by epidote, chlorite, and pyrite that is particularly well developed in the Laramide volcaniclastic rocks and Proterozoic dolerite sills. The potassic and propylitic assemblages were overprinted in the upper parts of the deposit by intense phyllic and advanced argillic alteration. The district was disrupted by Tertiary Basin and Range extension, and the fault block containing Resolution and its Cretaceous host succession was buried under thick mid-Miocene dacitic volcanic cover, obscuring the geologic, geophysical, and geochemical footprint of the deposit. To test the potential of propylitic mineral chemistry analyses to aid in the detection of concealed porphyry deposits, a blind test was conducted using a suite of epidote-chlorite ± pyrite-altered Laramide volcaniclastic rocks and Proterozoic dolerites collected from the propylitic halo, with samples taken from two domains located to the north and south and above the Resolution ore zone. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data of epidote provided indications of deposit fertility and proximity. Competition for chalcophile elements (As, Sb, Pb) between coexisting pyrite and epidote grains led to a subdued As-Sb fertility response in epidote, consistent with epidote collected between 0.7 and 1.5 km from the center of a large porphyry deposit. Temperature-sensitive trace elements in chlorite provided coherent spatial zonation patterns, implying a heat source centered at depth between the two sample clusters, and application of chlorite proximitor calculations based on LA-ICP-MS analyses provided a precisely defined drill target in this location in three dimensions. Drilling of this target would have resulted in the discovery of Resolution, confirming that epidote and chlorite mineral chemistry can potentially add value to porphyry exploration under cover

    Goal setting and self-efficacy among delinquent, at-risk and not at-risk adolescents

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    Setting clear achievable goals that enhance self-efficacy and reputational status directs the energies of adolescents into socially conforming or non-conforming activities. This present study investigates the characteristics and relationships between goal setting and self-efficacy among a matched sample of 88 delinquent (18 % female), 97 at-risk (20 % female), and 95 not at-risk adolescents (20 % female). Four hypotheses related to this were tested. Findings revealed that delinquent adolescents reported fewest goals, set fewer challenging goals, had a lower commitment to their goals, and reported lower levels of academic and self-regulatory efficacy than those in the at-risk and not at-risk groups. Discriminant function analysis indicated that adolescents who reported high delinquency goals and low educational and interpersonal goals were likely to belong to the delinquent group, while adolescents who reported high educational and interpersonal goals and low delinquency goals were likely to belong to the not at-risk group. The at-risk and not at-risk groups could not be differentiated. A multinomial logistic regression also revealed that adolescents were more likely to belong to the delinquent group if they reported lower self-regulatory efficacy and lower goal commitment. These findings have important implications for the development of prevention and intervention programs, particularly for those on a trajectory to delinquency. Specifically, programs should focus on assisting adolescents to develop clear self-set achievable goals and support them through the process of attaining them, particularly if the trajectory towards delinquency is to be addressed

    Effects of regular salt marsh haying on marsh plants, algae, invertebrates and birds at Plum Island Sound, Massachusetts

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Wetlands Ecology and Management 17 (2009): 469-487, doi: 10.1007/s11273-008-9125-3.The haying of salt marshes, a traditional activity since colonial times in New England, still occurs in about 400 ha of marsh in the Plum Island Sound estuary in northeastern Massachusetts. We took advantage of this haying activity to investigate how the periodic large-scale removal of aboveground biomass affects a number of marsh processes. Hayed marshes were no different from adjacent reference marshes in plant species density (species per area) and end-of-year aboveground biomass, but did differ in vegetation composition. Spartina patens was more abundant in hayed marshes than S. alterniflora, and the reverse was true in reference marshes. The differences in relative covers of these plant species were not associated with any differences between hayed and reference marshes in the elevations of the marsh platform. Instead it suggested that S. patens was more tolerant of haying than S. alterniflora. S. patens had higher stem densities in hayed marshes than it did in reference marshes, suggesting that periodic cutting stimulated tillering of this species. Although we predicted that haying would stimulate benthic chlorophyll production by opening up the canopy, we found differences to be inconsistent, possibly due to the relatively rapid regrowth of S. patens and to grazing by invertebrates on the algae. The pulmonate snail, Melampus bidendatus was depleted in its δ13C content in the hayed marsh compared to the reference, suggesting a diet shift to benthic algae in hayed marshes. The stable isotope ratios of a number of other consumer species were not affected by haying activity. Migratory shorebirds cue in to recently hayed marshes and may contribute to short term declines in some invertebrate species, however the number of taxa per unit area of marsh surface invertebrates and their overall abundances were unaffected by haying over the long term. Haying had no impact on nutrient concentrations in creeks just downstream from hayed plots, but the sediments of hayed marshes were lower in total N and P compared to references. In sum, haying appeared to affect plant species composition but had only short-term affects on consumer organisms. This contrasts with many grassland ecosystems, where an intermediate level of disturbance, such as by grazing, increases species diversity and may stimulate productivity. From a management perspective, periodic mowing could be a way to maintain S. patens habitats and the suite of species with which they are associated.This research was supported by the Plum Island Ecosystem Long Term Ecological Research program (OCE-972692 and OCE 0423565) of the National Science Foundation (NSF). J. Horowitz and J. Ludlam were supported by NSF Research Experience for Undergraduate (REU) grants when they were students at Hampshire College and Gordon College respectively

    The working alliance in a randomized controlled trial comparing online with face-to-face cognitive-behavioral therapy for depression

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    Background: Although numerous efficacy studies in recent years have found internet-based interventions for depression to be effective, there has been scant consideration of therapeutic process factors in the online setting. In face-to face therapy, the quality of the working alliance explains variance in treatment outcome. However, little is yet known about the impact of the working alliance in internet-based interventions, particularly as compared with face-to-face therapy. Methods: This study explored the working alliance between client and therapist in the middle and at the end of a cognitive-behavioral intervention for depression. The participants were randomized to an internet-based treatment group (n = 25) or face-to-face group (n = 28). Both groups received the same cognitive behavioral therapy over an 8-week timeframe. Participants completed the Beck Depression Inventory (BDI) post-treatment and the Working Alliance Inventory at mid- and post- treatment. Therapists completed the therapist version of the Working Alliance Inventory at post-treatment. Results: With the exception of therapists' ratings of the tasks subscale, which were significantly higher in the online group, the two groups' ratings of the working alliance did not differ significantly. Further, significant correlations were found between clients' ratings of the working alliance and therapy outcome at post-treatment in the online group and at both mid- and post-treatment in the face-to-face group. Correlation analysis revealed that the working alliance ratings did not significantly predict the BDI residual gain score in either group. Conclusions: Contrary to what might have been expected, the working alliance in the online group was comparable to that in the face-to-face group. However, the results showed no significant relations between the BDI residual gain score and the working alliance ratings in either group

    C9ORF72 interaction with cofilin modulates actin dynamics in motor neurons.

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    Intronic hexanucleotide expansions in C9ORF72 are common in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, but it is unknown whether loss of function, toxicity by the expanded RNA or dipeptides from non-ATG-initiated translation are responsible for the pathophysiology. We determined the interactome of C9ORF72 in motor neurons and found that C9ORF72 was present in a complex with cofilin and other actin binding proteins. Phosphorylation of cofilin was enhanced in C9ORF72-depleted motor neurons, in patient-derived lymphoblastoid cells, induced pluripotent stem cell-derived motor neurons and post-mortem brain samples from ALS patients. C9ORF72 modulates the activity of the small GTPases Arf6 and Rac1, resulting in enhanced activity of LIM-kinases 1 and 2 (LIMK1/2). This results in reduced axonal actin dynamics in C9ORF72-depleted motor neurons. Dominant negative Arf6 rescues this defect, suggesting that C9ORF72 acts as a modulator of small GTPases in a pathway that regulates axonal actin dynamics

    Differential Effects of Pravastatin and Simvastatin on the Growth of Tumor Cells from Different Organ Sites

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    3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) inhibitors, commonly known as statins, may possess cancer preventive and therapeutic properties. Statins are effective suppressors of cholesterol synthesis with a well-established risk-benefit ratio in cardiovascular disease prevention. Mechanistically, targeting HMGCR activity primarily influences cholesterol biosynthesis and prenylation of signaling proteins. Pravastatin is a hydrophilic statin that is selectively taken up by a sodium-independent organic anion transporter protein-1B1 (OATP1B1) exclusively expressed in liver. Simvastatin is a hydrophobic statin that enters cells by other mechanisms. Poorly-differentiated and well-differentiated cancer cell lines were selected from various tissues and examined for their response to these two statins. Simvastatin inhibited the growth of most tumor cell lines more effectively than pravastatin in a dose dependent manner. Poorly-differentiated cancer cells were generally more responsive to simvastatin than well-differentiated cancer cells, and the levels of HMGCR expression did not consistently correlate with response to statin treatment. Pravastatin had a significant effect on normal hepatocytes due to facilitated uptake and a lesser effect on prostate PC3 and colon Caco-2 cancer cells since the OATP1B1 mRNA and protein were only found in the normal liver and hepatocytes. The inhibition of cell growth was accompanied by distinct alterations in mitochondrial networks and dramatic changes in cellular morphology related to cofilin regulation and loss of p-caveolin. Both statins, hydrophilic pravastatin and hypdrophobic simvastatin caused redistribution of OATP1B1 and HMGCR to perinuclear sites. In conclusion, the specific chemical properties of different classes of statins dictate mechanistic properties which may be relevant when evaluating biological responses to statins
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