1,069 research outputs found
Histological evidence for a supraspinous ligament in sauropod dinosaurs
Supraspinous ossified rods have been reported in the sacra of some derived sauropod dinosaurs. Although different hypotheses have been proposed to explain the origin ofthis structure, histological evidence has never been provided to support or reject any of them. In order to establish its origin, we analyse and characterize the microstructure of thesupraspinous rod of two sauropod dinosaurs from the Upper Cretaceous of Argentina. The supraspinous ossified rod is almost entirely formed by dense Haversian bone. Remains ofprimary bone consist entirely of an avascular tissue composed of two types of fibre-like structures, which are coarse and longitudinally (parallel to the main axis of the element) oriented. These structures are differentiated on the basis of their optical properties under polarized light. Very thin fibrous strands are also observed in some regions. These small fibres are all oriented parallel to one another but perpendicular to the element main axis. Histological features of the primary bone tissue indicate that the sacral supraspinous rod corresponds to an ossified supraspinous ligament. The formation of this structure appears to have been a non-pathological metaplastic ossification, possibly induced by the continuous tensile forces applied to the element.Fil: Cerda, Ignacio Alejandro. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en PaleobiologÃa y GeologÃa; Argentina. Universidad Nacional de RÃo Negro; ArgentinaFil: Casal, Gabriel. Universidad Nacional de la Patagonia; ArgentinaFil: MartÃnez, Rubén DarÃo. Universidad Nacional de la Patagonia ; ArgentinaFil: Ibiricu, Lucio Manuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Nacional Patagónico; Argentin
Vectorial Control of Magnetization by Light
Coherent light-matter interactions have recently extended their applications
to the ultrafast control of magnetization in solids. An important but
unrealized technique is the manipulation of magnetization vector motion to make
it follow an arbitrarily designed multi-dimensional trajectory. Furthermore,
for its realization, the phase and amplitude of degenerate modes need to be
steered independently. A promising method is to employ Raman-type nonlinear
optical processes induced by femtosecond laser pulses, where magnetic
oscillations are induced impulsively with a controlled initial phase and an
azimuthal angle that follows well defined selection rules determined by the
materials' symmetries. Here, we emphasize the fact that temporal variation of
the polarization angle of the laser pulses enables us to distinguish between
the two degenerate modes. A full manipulation of two-dimensional magnetic
oscillations is demonstrated in antiferromagnetic NiO by employing a pair of
polarization-twisted optical pulses. These results have lead to a new concept
of vectorial control of magnetization by light
Phase 3 Multicenter Study of Revusiran in Patients with Hereditary Transthyretin-Mediated (hATTR) Amyloidosis with Cardiomyopathy (ENDEAVOUR)
PURPOSE: The Phase 3 ENDEAVOUR study evaluated revusiran, an investigational RNA interference therapeutic targeting hepatic transthyretin (TTR) production, for treating cardiomyopathy caused by hereditary transthyretin-mediated (hATTR) amyloidosis. / METHODS: Patients with hATTR amyloidosis with cardiomyopathy were randomized 2:1 to receive subcutaneous daily revusiran 500 mg (n = 140) or placebo (n = 66) for 5 days over a week followed by weekly doses. Co-primary endpoints were 6-min walk test distance and serum TTR reduction. / RESULTS: Revusiran treatment was stopped after a median of 6.71 months; the study Sponsor prematurely discontinued dosing due to an observed mortality imbalance between treatment arms. Eighteen (12.9%) patients on revusiran and 2 (3.0%) on placebo died during the on-treatment period. Most deaths in both treatment arms were adjudicated as cardiovascular due to heart failure (HF), consistent with the natural history of the disease. A post hoc safety investigation of patients treated with revusiran found that, at baseline, a greater proportion of those who died were ≥ 75 years and showed clinical evidence of more advanced HF compared with those who were alive throughout treatment. Revusiran pharmacokinetic exposures and TTR lowering did not show meaningful differences between patients who died and who were alive. Revusiran did not deleteriously affect echocardiographic parameters, cardiac biomarkers, or frequency of cardiovascular and HF hospitalization events. / CONCLUSIONS: Causes for the observed mortality imbalance associated with revusiran were thoroughly investigated and no clear causative mechanism could be identified. Although the results suggest similar progression of cardiac parameters in both treatment arms, a role for revusiran cannot be excluded. / CLINICAL TRIAL REGISTRATION: NCT02319005
Neighborhood fast food restaurants and fast food consumption: A national study
<p>Abstract</p> <p>Background</p> <p>Recent studies suggest that neighborhood fast food restaurant availability is related to greater obesity, yet few studies have investigated whether neighborhood fast food restaurant availability promotes fast food consumption. Our aim was to estimate the effect of neighborhood fast food availability on frequency of fast food consumption in a national sample of young adults, a population at high risk for obesity.</p> <p>Methods</p> <p>We used national data from U.S. young adults enrolled in wave III (2001-02; ages 18-28) of the National Longitudinal Study of Adolescent Health (n = 13,150). Urbanicity-stratified multivariate negative binomial regression models were used to examine cross-sectional associations between neighborhood fast food availability and individual-level self-reported fast food consumption frequency, controlling for individual and neighborhood characteristics.</p> <p>Results</p> <p>In adjusted analysis, fast food availability was not associated with weekly frequency of fast food consumption in non-urban or low- or high-density urban areas.</p> <p>Conclusions</p> <p>Policies aiming to reduce neighborhood availability as a means to reduce fast food consumption among young adults may be unsuccessful. Consideration of fast food outlets near school or workplace locations, factors specific to more or less urban settings, and the role of individual lifestyle attitudes and preferences are needed in future research.</p
Effectiveness of proactive telephone counselling for smoking cessation in parents: Study protocol of a randomized controlled trial
Contains fulltext :
99284.pdf (publisher's version ) (Open Access)Background
Smoking is the world's fourth most common risk factor for disease, the leading preventable cause of death, and it is associated with tremendous social costs. In the Netherlands, the smoking prevalence rate is high. A total of 27.7% of the population over age 15 years smokes. In addition to the direct advantages of smoking cessation for the smoker, parents who quit smoking may also decrease their children's risk of smoking initiation.
Methods/Design
A randomized controlled trial will be conducted to evaluate the effectiveness of proactive telephone counselling to increase smoking cessation rates among smoking parents. A total of 512 smoking parents will be proactively recruited through their children's primary schools and randomly assigned to either proactive telephone counselling or a control condition. Proactive telephone counselling will consist of up to seven counsellor-initiated telephone calls (based on cognitive-behavioural skill building and Motivational Interviewing), distributed over a period of three months. Three supplementary brochures will also be provided. In the control condition, parents will receive a standard brochure to aid smoking cessation. Assessments will take place at baseline, three months after start of the intervention (post-measurement), and twelve months after start of the intervention (follow-up measurement). Primary outcome measures will include sustained abstinence between post-measurement and follow-up measurement and 7-day point prevalence abstinence and 24-hours point prevalence abstinence at both post- and follow-up measurement. Several secondary outcome measures will also be included (e.g., smoking intensity, smoking policies at home). In addition, we will evaluate smoking-related cognitions (e.g., attitudes towards smoking, social norms, self-efficacy, intention to smoke) in 9-12 year old children of smoking parents.
Discussion
This study protocol describes the design of a randomized controlled trial to evaluate the effectiveness of proactive telephone counselling in smoking cessation. It is expected that, in the telephone counseling condition, parental smoking cessation rates will be higher and children's cognitions will be less favorable about smoking compared to the control condition.
Trial registration
The protocol for this study is registered with the Netherlands Trial Register NTR2707.6 p
Psammocarcinoma of ovary with serous cystadenofibroma of contralateral ovary: a case report
<p>Abstract</p> <p>Introduction</p> <p>Psammocarcinoma of ovary is a rare serous neoplasm characterized by extensive formation of psammoma bodies, invasion of ovarian stroma, peritoneum or intraperitoneal viscera, and moderate cytological atypia. Extensive medlar search showed presence of only 28 cases of psammocarcinoma of ovary reported till date.</p> <p>Case presentation</p> <p>We herein report a case of psammocarcinoma of ovary with serous cystadenofibroma of contralateral ovary in a 55 year old Asian Indian female.</p> <p>Conclusion</p> <p>To the best of author's knowledge, ours is the rare case describing coexistence of this very rare malignant serous epithelial tumor with a benign serous cystadenofibroma of contralateral ovary.</p
Sex-biased parental care and sexual size dimorphism in a provisioning arthropod
The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests.
To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest.
We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight.
Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species
Local structural distortions and reduced thermal conductivity in Ge-substituted chalcopyrite
Chalcopyrite, CuFeS2 is considered one of the promising n-type thermoelectric materials with high natural abundance as a mineral. In this work, partial substitution of germanium in materials CuFe1−xGexS2, (0.0 ≤ x ≤ 0.10), leads to an almost six-fold enhancement of thermoelectric properties. X-Ray photoelectron spectroscopy (XPS) reveals that germanium is present in two oxidation states: Ge2+ and Ge4+. The stereochemically-active 4s2 lone-pair of electrons associated with Ge2+ induces a local structural distortion. Pair-distribution function (PDF) analysis reveal that Ge2+ ions are displaced from the centre of the GeS4 tetrahedron towards a triangular face, leading to pseudo-trigonal pyramidal coordination. This distortion is accompanied by lattice softening and an increase of the strain-fluctuation scattering parameter (GS), leading to a decrease in thermal conductivity. Phonon calculations demonstrate that germanium substitution leads to the appearance of resonant phonon modes. These modes lie close in energy to the acoustic and low-energy optical modes of the host matrix, with which they can interact, providing an additional mechanism for reducing the thermal conductivity. The weak chemical bonding of germanium with sulphur also leads to localized electronic states near the Fermi level which results in a high density-of-states effective mass, enabling a relatively high Seebeck coefficient to be maintained, despite the reduced electrical resistivity. This combination produces an almost three-fold improvement in the power factor, which when coupled with the substantial reduction in thermal conductivity, leads to a maximum figure-of-merit, zT ∼ 0.4 at 723 K for CuFe0.94Ge0.06S2
Emergence of Pituitary Adenoma in a Child during Surveillance: Clinical Challenges and the Family Members' View in an AIP Mutation-Positive Family.
Introduction: Germline aryl hydrocarbon receptor-interacting protein (AIP) mutations are responsible for 15-30% of familial isolated pituitary adenomas (FIPAs). We report a FIPA kindred with a heterozygous deletion in AIP, aiming to highlight the indications and benefits of genetic screening, variability in clinical presentations, and management challenges in this setting. Patients: An 18-year-old male was diagnosed with a clinically nonfunctioning pituitary adenoma (NFPA). Two years later, his brother was diagnosed with a somatolactotrophinoma, and a small Rathke's cleft cyst and a microadenoma were detected on screening in their 17-year-old sister. Following amenorrhoea, their maternal cousin was diagnosed with hyperprolactinaemia and two distinct pituitary microadenomas. A 12-year-old niece developed headache and her MRI showed a microadenoma, not seen on a pituitary MRI scan 3 years earlier. Discussion: Out of the 14 members harbouring germline AIP mutations in this kindred, 5 have pituitary adenoma. Affected members had different features and courses of disease. Bulky pituitary and not fully suppressed GH on OGTT can be challenging in the evaluation of females in teenage years. Multiple pituitary adenomas with different secretory profiles may arise in the pituitary of these patients. Small, stable NFPAs can be present in mutation carriers, similar to incidentalomas in the general population. Genetic screening and baseline review, with follow-up of younger subjects, are recommended in AIP mutation-positive families.Pedro Marques is supported by Barts and The London Charity Clinical Training Research Fellowship. Márta Korbonits’s project on familial pituitary adenomas is supported by the Medical Research Council, UK
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