125 research outputs found
A mass stranding of squid Martialia hyadesi Rochebrunne & Mabille (Teuthoidea: Ommastrepidae) at Macquarie Island
A large number of squid, subsequently identified as Martialia hyadesi (Ommastrephidae) was stranded on beaches at the northern end of Macquarie Island, 54Β°30'S, 158Β°57'E, on 5 March 1971. The squid were immature, or at least pre-breeding, and had been feeding recently. It is suggested that a sudden change in wind direction, coupled with a rising tide, caused the stranding. This is the first reported stranding of this species, which has not previously been recorded in the Pacific region
Earthquake risk on the Sunda trench
On 28 March 2005 the Sunda megathrust in Indonesia ruptured again, producing another great earthquake three months after the previous one. The rupture was contiguous with that of the December 2004 SumatraβAndaman earthquake, and is likely to have been sparked by local stress, although the triggering stresses at its hypocentre were very small β of the order of just 0.1 bar. Calculations show that stresses imposed by the second rupture have brought closer to failure the megathrust immediately to the south, under the Batu and Mentawai islands, and have expanded the area of increased stress on the Sumatra fault. Palaeoseismologic studies show that the Mentawai segment of the Sunda megathrust is well advanced in its seismic cycle and is therefore a good candidate for triggered failure
Silicon isotopic systematics of deep-sea sponge grounds in the North Atlantic
Β© 2019 Elsevier Ltd Reconstruction of silica cycling in the oceans is key to a thorough understanding of past climates because of the inherent links between the biogeochemistry of silicifiers and sequestration of organic carbon. Diatoms are one of the most important phytoplankton groups in determining export production from surface waters, and rely largely on upwelling deeper waters as a source of dissolved silicon, an essential nutrient for their growth. Quantification of changes in deep water dissolved silicon concentrations in the past allows a more robust understanding of changes in surface nutrient supply and whole-ocean silicon cycling, but cannot be achieved using surface-derived geochemical archives. In the last few years, there has been increasing focus on the use of geochemical archives in siliceous skeletal elements, or spicules, from seafloor-dwelling sponges to fill this gap. The stable silicon isotopic composition of spicules has been shown to be a function of ambient dissolved silicon, providing a potential archive for past changes in bottom water nutrients. However, biomineralisation processes impact silicon isotope fractionation and silica formed by atypical processes (derived from carnivorous sponges, hypersilicified spicules, and giant basal spicules) result in anomalous geochemical signatures. Furthermore, there is considerable scatter in the calibration between spicule silicon isotopes and dissolved silicon in seawater, even when the atypical groups have been removed. Here, we explore this variability further, by examining aggregation and assemblage-level differences in isotopic fractionation, using silicon isotopic measurements of specimens from two monospecific sponge groups (Pheronema carpenteri and Vazella pourtalesi), and one mixed-species population (genus Geodia) from the North Atlantic. Our new data reveal that variability within the monospecific aggregations is less than mixed-species assemblage, pointing towards a genetic control in isotopic fractionation. However, there is still variability within the monospecific aggregations, which cannot be explained by macroscale environmental differences: such variability is likely a reflection of the physiological health of the individuals, or highly localised heterogeneities in sponge habitats. Other challenges remain in the interpretation of spicule silicon isotopes as proxies for dissolved silicon changes through time, especially when investigating periods of Earth history that extend back considerably further than the residence time of dissolved silicon in the oceans. Despite all the questions still surrounding the use of sponge silicon isotopes in palaeoceanographic applications, they are still the only known archive of bottom water dissolved silicon. Continued efforts to understanding sponge biomineralisation and to incorporate silicon isotopes into oceanic models will help to improve further the reliability of the archive
Maternal obesity support services: a qualitative study of the perspectives of women and midwives
Background -
Twenty percent of pregnant women in the UK are obese (BMI β₯ 30 kg/m2), reflecting the growing public health challenge of obesity in the 21st century. Obesity increases the risk of adverse outcomes during pregnancy and birth and has significant cost implications for maternity services. Gestational weight management strategies are a high priority; however the evidence for effective, feasible and acceptable weight control interventions is limited and inconclusive. This qualitative study explored the experiences and perceptions of pregnant women and midwives regarding existing support for weight management in pregnancy and their ideas for service development.
Methods -
A purposive sample of 6 women and 7 midwives from Doncaster, UK, participated in two separate focus groups. Transcripts were analysed thematically.
Results -
Two overarching themes were identified, 'Explanations for obesity and weight management' and 'Best care for pregnant women'. 'Explanations' included a lack of knowledge about weight, diet and exercise during pregnancy; self-talk messages which excused overeating; difficulties maintaining motivation for a healthy lifestyle; the importance of social support; stigmatisation; and sensitivity surrounding communication about obesity between midwives and their clients. 'Best care' suggested that weight management required care which was consistent and continuous, supportive and non-judgemental, and which created opportunities for interaction and mutual support between obese pregnant women.
Conclusions -
Women need unambiguous advice regarding healthy lifestyles, diet and exercise in pregnancy to address a lack of knowledge and a tendency towards unhelpful self-talk messages. Midwives expressed difficulties in communicating with their clients about their weight, given awareness that obesity is a sensitive and potentially stigmatising issue. This indicates more could be done to educate and support them in their work with obese pregnant women. Motivation and social support were strong explanatory themes for obesity and weight management, suggesting that interventions should focus on motivational strategies and social support facilitation
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The poleward migration of the location of tropical cyclone maximum intensity
Temporally inconsistent and potentially unreliable global historical data hinder the detection of trends in tropical cyclone activity. This limits our confidence in evaluating proposed linkages between observed trends in tropical cyclones and in the environment. Here we mitigate this difficulty by focusing on a metric that is comparatively insensitive to past data uncertainty, and identify a pronounced poleward migration in the average latitude at which tropical cyclones have achieved their lifetime-maximum intensity over the past 30 years. The poleward trends are evident in the global historical data in both the Northern and the Southern hemispheres, with rates of 53 and 62 kilometres per decade, respectively, and are statistically significant. When considered together, the trends in each hemisphere depict a global-average migration of tropical cyclone activity away from the tropics at a rate of about one degree of latitude per decade, which lies within the range of estimates of the observed expansion of the tropics over the same period. The global migration remains evident and statistically significant under a formal data homogenization procedure, and is unlikely to be a data artefact. The migration away from the tropics is apparently linked to marked changes in the mean meridional structure of environmental vertical wind shear and potential intensity, and can plausibly be linked to tropical expansion, which is thought to have anthropogenic contributions
Plate-boundary deformation associated with the great SumatraβAndaman earthquake
The SumatraβAndaman earthquake of 26 December 2004 is the first giant earthquake (moment magnitude M_w > 9.0) to have occurred since the advent of modern space-based geodesy and broadband seismology. It therefore provides an unprecedented opportunity to investigate the characteristics of one of these enormous and rare events. Here we report estimates of the ground displacement associated with this event, using near-field Global Positioning System (GPS) surveys in northwestern Sumatra combined with in situ and remote observations of the vertical motion of coral reefs. These data show that the earthquake was generated by rupture of the Sunda subduction megathrust over a distance of >1,500 kilometres and a width of <150 kilometres. Megathrust slip exceeded 20 metres offshore northern Sumatra, mostly at depths shallower than 30 kilometres. Comparison of the geodetically and seismically inferred slip distribution indicates that ~30 per cent additional fault slip accrued in the 1.5 months following the 500-second-long seismic rupture. Both seismic and aseismic slip before our re-occupation of GPS sites occurred on the shallow portion of the megathrust, where the large Aceh tsunami originated. Slip tapers off abruptly along strike beneath Simeulue Island at the southeastern edge of the rupture, where the earthquake nucleated and where an M_w = 7.2 earthquake occurred in late 2002. This edge also abuts the northern limit of slip in the 28 March 2005 M_w = 8.7 NiasβSimeulue earthquake
A randomized controlled trial on the effectiveness of strength training on clinical and muscle cellular outcomes in patients with prostate cancer during androgen deprivation therapy: rationale and design
Background
Studies indicate that strength training has beneficial effects on clinical health outcomes in prostate cancer patients during androgen deprivation therapy. However, randomized controlled trials are needed to scientifically determine the effectiveness of strength training on the muscle cell level. Furthermore, close examination of the feasibility of a high-load strength training program is warranted. The Physical Exercise and Prostate Cancer (PEPC) trial is designed to determine the effectiveness of strength training on clinical and muscle cellular outcomes in non-metastatic prostate cancer patients after high-dose radiotherapy and during ongoing androgen deprivation therapy.
Methods/design
Patients receiving androgen deprivation therapy for 9-36 months combined with external high-dose radiotherapy for locally advanced prostate cancer are randomized to an exercise intervention group that receives a 16 week high-load strength training program or a control group that is encouraged to maintain their habitual activity level. In both arms, androgen deprivation therapy is continued until the end of the intervention period.
Clinical outcomes are body composition (lean body mass, bone mineral density and fat mass) measured by Dual-energy X-ray Absorptiometry, serological outcomes, physical functioning (muscle strength and cardio-respiratory fitness) assessed with physical tests and psycho-social functioning (mental health, fatigue and health-related quality of life) assessed by questionnaires. Muscle cellular outcomes are a) muscle fiber size b) regulators of muscle fiber size (number of myonuclei per muscle fiber, number of satellite cells per muscle fiber, number of satellite cells and myonuclei positive for androgen receptors and proteins involved in muscle protein degradation and muscle hypertrophy) and c) regulators of muscle fiber function such as proteins involved in cellular stress and mitochondrial function. Muscle cellular outcomes are measured on muscle cross sections and muscle homogenate from muscle biopsies obtained from muscle vastus lateralis.
Discussion
The findings from the PEPC trial will provide new knowledge on the effects of high-load strength training on clinical and muscle cellular outcomes in prostate cancer patients during androgen deprivation therapy.
Trial registration
ClinicalTrials.gov:
NCT0065822
SFRP1 reduction results in an increased sensitivity to TGF-Ξ² signaling
Background Transforming growth factor (TGF)-Ξ² plays a dual role during mammary gland development and tumorigenesis and has been shown to stimulate epithelial-mesenchymal transition (EMT) as well as cellular migration. The Wnt/Ξ²-catenin pathway is also implicated in EMT and inappropriate activation of the Wnt/Ξ²-catenin signaling pathway leads to the development of several human cancers, including breast cancer. Secreted frizzled-related protein 1 (SFRP1) antagonizes this pathway and loss of SFRP1 expression is frequently observed in breast tumors and breast cancer cell lines. We previously showed that when SFRP1 is knocked down in immortalized non-malignant mammary epithelial cells, the cells (TERT-siSFRP1) acquire characteristics associated with breast tumor initiating cells. The phenotypic and genotypic changes that occur in response to SFRP1 loss are consistent with EMT, including a substantial increase in the expression of ZEB2. Considering that ZEB2 has been shown to interact with mediators of TGF-Ξ² signaling, we sought to determine whether TGF-Ξ² signaling is altered in TERT-siSFRP1 cells. Methods Luciferase reporter assays and real-time PCR analysis were employed to measure TGF-Ξ² transcriptional targets. Western blot analysis was used to evaluate TGF-Ξ²-mediated ERK1/2 phosphorylation. Migration chamber assays were utilized to quantify cellular migration. TERT-siSFRP1 cells were transfected with Stealth RNAiβ’ siRNA in order to knock-down the expression of ZEB2. Results TERT-siSFRP1 cells exhibit a significant increase in both TGF-Ξ²-mediated luciferase activity as well as TGF-Ξ² transcriptional targets, including Integrin Ξ²3 and PAI-1. Phosphorylation of ERK1/2 is increased in TERT-siSFRP1 cells in response to enhanced TGF-Ξ² signaling. Furthermore, when the TGF-Ξ² pathway is blocked with a TGF-Ξ²R antagonist (LY364947), cellular migration is significantly hindered. Finally, we found that when ZEB2 is knocked-down, there is a significant reduction in the expression of exogeneous and endogenous TGF-Ξ² transcriptional targets and cellular migration is impeded. Conclusions We demonstrate that down-regulation of SFRP1 renders mammary epithelial cells more sensitive to TGF-Ξ² signaling which can be partially ameliorated by blocking the expression of ZEB2
Lifestyle behaviors, obesity, and perceived health among men with and without a diagnosis of prostate cancer: A population-based, cross-sectional study
<p>Abstract</p> <p>Background</p> <p>A better understanding of how prostate cancer survivors differ from men without prostate cancer and whether these potential differences vary across demographic subgroups will help to focus and prioritize future public health interventions for improving the health and well-being of prostate cancer survivors. Therefore, our study aims were to compare lifestyle behaviors, body mass index (BMI), and perceived health in men with and without a diagnosis of prostate cancer in a national, population-based sample and to explore whether these comparisons differ for demographic subgroups.</p> <p>Methods</p> <p>In a cross-sectional study, men aged β₯ 40 were identified from the Behavioral Risk Factor Surveillance System (BRFSS) 2002 data (n = 63,662). Respondents reporting history of prostate cancer (n = 2,524) were compared with non prostate cancer controls (n = 61,138) with regard to daily fruit and vegetable servings (FVPD), smoking, alcohol, sedentary behavior, BMI, and perceived health. Multivariable logistic regression calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) for the entire sample and for age, race, education, and urbanicity subgroups.</p> <p>Results</p> <p>Men with prostate cancer did not differ from men without prostate cancer with regard to smoking, alcohol, sedentary behavior, and obesity but were more likely to consume β₯ 5 FVPD (OR, 95% CI: 1.30, 1.09β1.56) and report poor or fair health (OR, 95% CI: 1.62, 1.33β1.97). Subgroup analyses demonstrated attenuation of the higher likelihood of β₯ 5 FVPD among prostate cancer survivors in rural respondents (OR, 95% CI: 0.98, 0.72β1.33). Poorer perceived health was greatest if β€ 65 years of age (OR, 95% CI: 2.54, 1.79β3.60) and nonsignificant if black (OR, 95% CI: 1.41, 0.70β2.82). Smoking and alcohol which were not significant for the sample as a whole, demonstrated significant associations in certain subgroups.</p> <p>Conclusion</p> <p>Although efforts to enhance perceived health and healthy lifestyle behaviors among prostate cancer survivors are warranted, demographic subgroups such as prostate cancer survivors β€ 65 and rural populations may require more aggressive interventions.</p
Systematic Single-Cell Analysis of Pichia pastoris Reveals Secretory Capacity Limits Productivity
Biopharmaceuticals represent the fastest growing sector of the global pharmaceutical industry. Cost-efficient production of these biologic drugs requires a robust host organism for generating high titers of protein during fermentation. Understanding key cellular processes that limit protein production and secretion is, therefore, essential for rational strain engineering. Here, with single-cell resolution, we systematically analysed the productivity of a series of Pichia pastoris strains that produce different proteins both constitutively and inducibly. We characterized each strain by qPCR, RT-qPCR, microengraving, and imaging cytometry. We then developed a simple mathematical model describing the flux of folded protein through the ER. This combination of single-cell measurements and computational modelling shows that protein trafficking through the secretory machinery is often the rate-limiting step in single-cell production, and strategies to enhance the overall capacity of protein secretion within hosts for the production of heterologous proteins may improve productivity
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