75 research outputs found
Loss of ATRX in Chondrocytes Has Minimal Effects on Skeletal Development
BACKGROUND:Mutations in the human ATRX gene cause developmental defects, including skeletal deformities and dwarfism. ATRX encodes a chromatin remodeling protein, however the role of ATRX in skeletal development is currently unknown. METHODOLOGY/PRINCIPAL FINDINGS:We induced Atrx deletion in mouse cartilage using the Cre-loxP system, with Cre expression driven by the collagen II (Col2a1) promoter. Growth rate, body size and weight, and long bone length did not differ in Atrx(Col2cre) mice compared to control littermates. Histological analyses of the growth plate did not reveal any differences between control and mutant mice. Expression patterns of Sox9, a transcription factor required for cartilage morphogenesis, and p57, a marker of cell cycle arrest and hypertrophic chondrocyte differentiation, was unaffected. However, loss of ATRX in cartilage led to a delay in the ossification of the hips in some mice. We also observed hindlimb polydactily in one out of 61 mutants. CONCLUSIONS/SIGNIFICANCE:These findings indicate that ATRX is not directly required for development or growth of cartilage in the mouse, suggesting that the short stature in ATR-X patients is caused by defects in cartilage-extrinsic mechanisms
On supersymmetric quantum mechanics
This paper constitutes a review on N=2 fractional supersymmetric Quantum
Mechanics of order k. The presentation is based on the introduction of a
generalized Weyl-Heisenberg algebra W_k. It is shown how a general Hamiltonian
can be associated with the algebra W_k. This general Hamiltonian covers various
supersymmetrical versions of dynamical systems (Morse system, Poschl-Teller
system, fractional supersymmetric oscillator of order k, etc.). The case of
ordinary supersymmetric Quantum Mechanics corresponds to k=2. A connection
between fractional supersymmetric Quantum Mechanics and ordinary supersymmetric
Quantum Mechanics is briefly described. A realization of the algebra W_k, of
the N=2 supercharges and of the corresponding Hamiltonian is given in terms of
deformed-bosons and k-fermions as well as in terms of differential operators.Comment: Review paper (31 pages) to be published in: Fundamental World of
Quantum Chemistry, A Tribute to the Memory of Per-Olov Lowdin, Volume 3, E.
Brandas and E.S. Kryachko (Eds.), Springer-Verlag, Berlin, 200
Dietary intake and breast density in high-risk women: a cross-sectional study
Background Women with a family history of breast cancer may be at higher risk for breast cancer, but few previous studies evaluating diet and breast cancer have focused on such women. The objective of the present study was to determine whether diet, a modifiable risk factor, is related to breast density among women at high genetic risk for breast cancer. Methods Women with at least one first-degree or second-degree relative with breast cancer or ovarian cancer participating in the Fox Chase Cancer Center Family Risk Assessment Program completed health history and food frequency questionnaires and received standard screening mammograms. Cranial–caudal mammographic images were classified into the four Breast Imaging Reporting and Data System categories ranging from \u27entirely fatty\u27 to \u27extremely dense\u27. Logistic regression analysis using proportional odds models for polychotomous outcomes provided estimates of odds ratios for having a higher category versus a lower category of breast density. Results Among 157 high-risk women, breast density was inversely associated with vitamin D intake (odds ratio for third tertile versus first tertile, 0.5; 95% confidence interval, 0.2–1.0). In contrast, intakes above the median level for protein (odds ratio, 3.0; 95% confidence interval, 1.3–6.9) and above the median level for animal protein (odds ratio, 4.3; 95% confidence interval, 1.8–10.3) were associated with higher breast density, but only among women whose family history did not reflect a known familial cancer syndrome or a breast cancer predisposition gene. Conclusion For women with a strong family history that was not associated with known cancer syndromes, dietary factors may be associated with breast density, a strong predictor of breast cancer risk. Since women with strong family history are often very motivated to change their lifestyle habits, further studies are needed to confirm whether changes in diet will change the breast density and the subsequent onset of breast cancer in these women
Vitamin D and breast cancer: interpreting current evidence
Preclinical investigations and selected clinical observational studies support an association between higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk. However, the recently updated report from the Institute of Medicine concluded that, for cancer and vitamin D, the evidence was 'inconsistent and insufficient to inform nutritional requirements'. Against this background, reports examining vitamin D intake, 25-hydroxyvitamin D levels and breast cancer incidence and outcome were reviewed. Current evidence supports the pursuit of several research questions but not routine 25-hydroxyvitamin D monitoring and vitamin D supplementation to reduce breast cancer incidence or improve breast cancer outcome
Are sciences essential and humanities elective? Disentangling competing claims for humanities research public value
[EN] Recent policy discourse suggests that arts and humanities research is seen as being less useful to society than other disciplines, notably in science, technology, engineering and mathematics. The paper explores how this assumption s construction has been built and whether it is based upon an unfair prejudice: we argue for a prima facie case to answer in assuming that arts and humanities research s lower societal value. We identify a set of claims circulating in policy circles regarding science, technology, engineering and math- ematics research and arts and humanities research s differences. We find two groups: arts and humanities research is less useful than science, technology, engineering and mathematics, and arts and humanities research is merely differently useful. We argue that empirical analysis is necessary to disentangle which ones are true to assess whether policy-making is being based on rational and evidence-based claims. We argue that debates about public research value should recognise that humanities have different (but equally valid) kinds of societal value.This work was supported by the Spanish Ministry of Education, which funded the PhD research fellowship of Julia Olmos Peñuela through the F.P.U program [AP2007- 01850]. The research fellowship took place in the framework of the HERAVALUE project, Measuring the public value of arts and humanities research, financially supported by the HERA Joint Research Programme, cofunded by AHRC, AKA, DASTI, ETF, FNR, FWF, HAZU, IRCHSS, MHEST, NWO, RANNIS, RCN, VR and The European Community FP7 2007-2013, under the Socio-economic Sciences and Humanities programme. The
authors would like to thank the editors and two anonymous referees for their invaluable comments. Any errors or omissions remain the authors’ responsibilitieOlmos-Peñuela, J.; Benneworth, P.; Castro-MartÃnez, E. (2015). Are sciences essential and humanities elective? Disentangling competing claims for humanities research public value. Arts and Humanities in Higher Education. 14(1):61-78. https://doi.org/10.1177/1474022214534081S617814
Monitoring Winter and Summer Abundance of Cetaceans in the Pelagos Sanctuary (Northwestern Mediterranean Sea) Through Aerial Surveys
Systematic long-term monitoring of abundance is essential to inform conservation measures and evaluate their effectiveness. To instigate such work in the Pelagos Sanctuary in the Mediterranean, two aerial surveys were conducted in winter and summer 2009. A total of 467 (131 in winter, 336 in summer) sightings of 7 species was made. Sample sizes were sufficient to estimate abundance of fin whales in summer (148; 95% CI = 87–254) and striped dolphins in winter (19,462; 95% CI = 12 939–29 273) and in summer (38 488; 95% CI = 27 447–53 968). Numbers of animals within the Sanctuary are significantly higher in summer, when human activities and thus potential population level impacts are highest. Comparisons with data from past shipboard surveys suggest an appreciable decrease in fin whales within the Sanctuary area and an appreciable increase in striped dolphins. Aerial surveys proved to be more efficient than ship surveys, allowing more robust estimates, with smaller CIs and CVs. These results provide essential baseline data for this marine protected area and continued regular surveys will allow the effectiveness of the MPA in terms of cetacean conservation to be evaluated and inform future management measures. The collected data may also be crucial in assessing whether ship strikes, one of the main causes of death for fin whales in the Mediterranean, are affecting the Mediterranean population
Drivers of population structure of the bottlenose dolphin (Tursiops truncatus) in the Eastern Mediterranean Sea
The drivers of population differentiation in oceanic high dispersal organisms, have been crucial for research in evolutionary biology. Adaptation to different environments is commonly invoked as a driver of differentiation in the oceans, in alternative to geographic isolation. In this study, we investigate the population structure and phylogeography of the bottlenose dolphin (Tursiops truncatus) in the Mediterranean Sea, using microsatellite loci and the entire mtDNA control region. By further comparing the Mediterranean populations with the well described Atlantic populations, we addressed the following hypotheses: (1) bottlenose dolphins show population structure within the environmentally complex Eastern Mediterranean Sea; (2) population structure was gained locally or otherwise results from chance distribution of preexisting genetic structure; (3) strong demographic variations within the Mediterranean basin have affected genetic variation sufficiently to bias detected patterns of population structure. Our results suggest that bottlenose dolphin exhibits population structures that correspond well to the main Mediterranean oceanographic basins. Furthermore, we found evidence for fine scale population division within the Adriatic and the Levantine seas. We further describe for the first time, a distinction between populations inhabiting pelagic and coastal regions within the Mediterranean. Phylogeographic analysis suggests that current genetic structure, results mostly from stochastic distribution of Atlantic genetic variation, during a recent postglacial expansion. Comparison with Atlantic mtDNA haplotypes, further suggest the existence of a metapopulation across North Atlantic/Mediterranean, with pelagic regions acting as source for coastal environments
Marine mammals and Good Environmental Status: Science, Policy and Society; Challenges and Opportunities
The Marine Strategy Framework Directive has become the key instrument for marine conservation in European seas. We review its implementation, focusing on cetacean biodiversity, using
the examples of Spain and the Regional Seas Convention, OSPAR. The MSFD has been widely criticised for legal vagueness, lack of coordination,
uncertainty about funding, and poor governance; its
future role within EU Integrated Maritime Policy
remains unclear. Nevertheless, the first stages of the
process have run broadly to schedule: current status,
environmental objectives and indicators have been
described and the design of monitoring programmes is in progress, drawing on experience with other environmental
legislation. The MSFD is now entering its
critical phase, with lack of funding for monitoring,
limited scope for management interventions, and
uncertainty about how conservation objectives will
be reconciled with the needs of other marine and
maritime sectors, being among the main concerns.
Clarity in governance, about the roles of the EU,
Member States, Regional Seas Conventions and
stakeholders, is needed to ensure success. However,
even if (as seems likely) good environmental status
cannot be achieved by 2020, significant steps will have been taken to place environmental sustainability
centre-stage in the development of Integrated Maritime
Policy for EU seas.Postprin
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