713 research outputs found
Carbon and nitrogen assimilation in the Bering Sea clams Nuculana radiata and Macoma moesta
We analyzed bulk carbon and nitrogen stable isotope values (delta C-13 and delta N-15) of the benthic clams Nuculana radiata and Macoma moesta from the Bering Sea during controlled feeding experiments (spring of 2009 and 2010) using isotopically labeled sea ice algae. The aim was to determine the ability of these clam species to assimilate carbon and nitrogen from sea ice algae. Specimens were collected in the Bering Sea and placed into jars without sediment (2009, N. radiata only) or into natural sediment cores (2010, both species). The clams were offered isotopically enriched (both C and N) or non-enriched algal feeds for time periods of 42 (2009) and 18 d (2010). Isotopic assimilation rates for carbon and nitrogen were calculated using the change in the isotope ratios of the clams over the experimental time. N. radiata in the jar experiments had slow isotopic assimilation rates (0.01 to 0.23 parts per thousand d(-1)), with solvent-extractable organic matter/lipids taking up both of the isotope markers fastest and muscle tissue the slowest. Lipids may thus be particularly suitable to track the immediate ingestion of sea ice algal production in benthic consumers. M. moesta showed 30% higher isotopic assimilation compared to N. radiata in sediment cores, likely reflecting the different feeding behaviors of these two species. Based on our results, N. radiata is likely better able to utilize food sources buried in the sediment and may be more competitive over the sediment surface feeding M. moesta under conditions of reduced ice algal production in the northern Bering Sea. (C) 2012 Elsevier B.V. All rights reserved.This project was undertaken as a part of the National Science Foundation
funded Bering Sea Ecosystem Study (BEST Project) #0732767awarded to R. Gradinger, K. Iken, and B. Bluhm at the University of Alaska Fairbanks. Additional research funding to J. Weems was provided by the UAF Center for Global Change Student Research Grant with funds from the Cooperative Institute for Alaska Research and the Harland and
Genevieve Emerson Foundation of Adel, Iowa. Bering Sea field support and operations in 2009 and 2010 were provided by chief scientists L. Cooper, J. Grebmeier, and C. Ashjian, and the vessels and crews of the United States Coast Guard Cutters Healy and Polar Sea. Additionally, field and laboratory aid was provided by B. Bluhm, M. Kaufman, B. McConnell, M. Schuster, and J. von Meltzer. Services rendered by the Alaska Stable Isotope Facility and its staff, N. Haubenstock and T. Howe, were very much appreciated. Academic support for J. Weems was provided by the School of Fisheries and Ocean Sciences at the University of Alaska Fairbanks. We thank M. Castellini and two anonymous reviewers for comments on earlier versions of this manuscript. Support for the fatty acid analyses and partial support forWooller came from NSF grant ARC 0902177 awarded to (Gradinger, Iken and Wooller). [ST]Ye
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Defining signatures of arm-wise copy number change and their associated drivers in kidney cancers
Using pan-cancer data from The Cancer Genome Atlas (TCGA), we investigated how patterns in copy number alterations in cancer cells vary both by tissue type and as a function of genetic alteration. We find that patterns in both chromosomal ploidy and individual arm copy number are dependent on tumour type. We highlight for example, the significant losses in chromosome arm 3p and the gain of ploidy in 5q in kidney clear cell renal cell carcinoma tissue samples. We find that specific gene mutations are associated with genome-wide copy number changes. Using
signatures derived from non-negative matrix factorisation (NMF), we also find gene mutations that are associated with particular patterns of ploidy change. Finally, utilising a set of machine learning classifiers, we successfully predicted the presence of mutated genes in a sample using arm-wise copy number patterns as features. This demonstrates that mutations in specific genes are correlated and may lead to specific patterns of ploidy loss and gain across chromosome arms. Using these same classifiers, we highlight which arms are most predictive of commonly mutated genes in kidney renal clear cell carcinoma (KIRC)
Late Holocene hydrologic and vegetation changes at Turneffe Atoli, Belize, compared with records from mainland Central America and Mexico
Studies on the breeding biology of the kittiwake (rissa tridactyla) using marked individuals
The attendance and activity of the members of Kittiwake pairs at their breeding sites was monitored throughout 5 successive breeding seasons using a radioisotope-marker technique. The seasonal occupation of the colony from January to November is described, together with the patterns of site occupation, nest-building, egg laying, incubation and brooding behaviour. Pair members share almost equally the duties of incubation and the brooding and feeding of the young. Although one partner can compensate considerably for the absence of its mate, both sexes must normally contribute for breeding to be successful. A high peak of activity prior to laying probably brings the female into ovulatory condition, and strengthens the pair bond just before shared incubation places the greatest strain upon it. These effects are probably mediated through arrival displays on the site. Comparisons revealed that established pairs and older, more experienced breeding individuals showed higher levels of activity and attendance than less experienced birds. The former also integrated their patterns of behaviour more effectively, and this probably contributes to their greater reproductive success. Naive individuals showed a marked improvement in their breeding activity during their second year together. However some inexperienced breeding individuals integrate their activities very successfully at their first attempt, whereas some experienced individuals do not. It is suggested that some measure of compatibility may be necessary for successful co-ordination of breeding activities between pad members. This idea of compatibility is consistent with the very considerable degree of heterogeneity in the patterns of pair behaviour recorded within the population, although established pairs showed very similar patterns in successive years
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On the interpretation of gravity variations in the presence of active hydrothermal systems: Insights from the Nisyros Caldera, Greece
We report on short-term (over tens of minutes) residual gravity changes recorded at the restless Nisyros caldera in Greece via a series of discrete measurements at benchmarks within or in proximity to a hydrothermal area located along the caldera floor. The obtained time series reveal sinusoidal gravity variations with amplitudes of up to 25 μGal and wavelengths of 40–50 min. Degassing of a magmatic source coupling into (shallow) hydrothermal systems including the ascent of steam pockets and transient pressure variations during steam/liquid interface propagation appear to be the most likely causative process for the observed short-term variations. We assess standard protocols of microgravity surveys for hazard assessment in volcanic areas in the light of these findings and propose additional techniques, such as continuous gravimetry, for the discrimination of hydrothermal signals from deeper-seated, i.e. magmatic, signals during gravity monitoring of restless volcanoes hosting active hydrothermal systems
Self-care mechanisms for police officers and military personnel exposed to terrorist documents : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University, Albany, New Zealand
Introduction. Police officers and military personnel are exposed to a wide range of potentially traumatic incidents due to the nature of their work. These incidents include arriving first to accidents and instituting initial assessments and treatments of victims. Police and military work may involve child victims of crime and abuse, violent, individual, and mass incidents, body retrievals, search and rescue, among others. Police officers and military personnel are generally exposed to terrorist documents while on overseas deployments. Despite a growing awareness from the general public of the impact of terrorism on both victims and first responders, most of the literature has focussed directly on victims of terrorism rather than first responders. The literature has focused on acts of terrorism but not that of terrorist documents. Method. The qualitative Delphi Method was used to gain information on possible self-care mechanisms that police officers and military personnel can use to help mitigate the potentially damaging psychological effects of being exposed to terrorist documents. This information was collected via a two-part process using a questionnaire that was distributed via email. Results. A total of five participants were recruited, all of whom completed both parts one and two of the study. The results provided in-depth answers to various questions regarding exposure to terrorist documents, occupational and organisational variables and varying questions around self-care both at the individual and organisational level. The results highlighted both practical and conceptual ideas as to how psychologists who have worked with first responder populations suggest police officers and military personnel who are exposed to terrorist documents within their work can protect themselves. Discussion. The results of the study presented individuals and organisations with strategies and methods that police officers and military personnel can use to protect themselves from the potentially adverse effects of exposure to terrorist documents. Limitations and future research suggestions are discussed with a focus on how this study can be expanded to provide self-care strategies to a broader population of first responders and to support a broader range of potentially traumatic exposures
The emplacement dynamics of pumice lobes ascertained from morphology and granulometry: Examples from the 1993 deposits at Lascar Volcano, Chile
Pedestrianisation: Are We Reading From the Same Page? Perspective From Key Stakeholders in Takapuna, Auckland
Transforming car-oriented streets into functional public spaces and pedestrianised environments has the potential to create environments that support active transport (e.g. walking and cycling), social interaction, and economic development. In the face of built environment characteristics, individual perceptions play a vital role in travel behaviour, spend characteristics, and social cohesion. This study investigates the perceived benefits of pedestrianising a shopping precinct in Takapuna, Auckland, New Zealand. Semi-structured interviews were conducted with nine stakeholders across three groups: shoppers, retailers, and local government. Shoppers and retailers perceived pedestrianisation schemes as a way of improving: aesthetics; connectivity and accessibility; safety; public transport infrastructure, and walking and cycling levels within the area. Retailers were also concerned about the impact of short-term construction on revenue. Local government respondents realised the potential of pedestrianising the site to improve existing infrastructure and become more economically competitive with other nearby retail options. All stakeholders recognised the importance and benefit of securing collaborative input into urban regeneration schemes. Any urban regeneration developments must be considered within a long-term cohesive strategic framework. Overall perceptions of pedestrianising Takapuna were seen as positive across all groups, and seen as being able to make improvements across multiple areas including further supporting business development
Computational approaches to identify genetic interactions for cancer therapeutics
The development of improved cancer therapies is frequently cited as an urgent unmet medical need. Here we describe how genetic interactions are being therapeutically exploited to identify novel targeted treatments for cancer. We discuss the current methodologies that use ‘omics data to identify genetic interactions, in particular focusing on synthetic sickness lethality (SSL) and synthetic dosage lethality (SDL). We describe the experimen- tal and computational approaches undertaken both in humans and model organisms to identify these interac- tions. Finally we discuss some of the identified targets with licensed drugs, inhibitors in clinical trials or with compounds under development
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