How patients understand depression associated with chronic physical disease - A systematic review

Background: Clinicians are encouraged to screen people with chronic physical illness for depression. Screening alone may not improve outcomes, especially if the process is incompatible with patient beliefs. The aim of this research is to understand peoples beliefs about depression, particularly in the presence of chronic physical disease. Methods: A mixed method systematic review involving a thematic analysis of qualitative studies and quantitative studies of beliefs held by people with current depressive symptoms. MEDLINE, EMBASE, PSYCHINFO, CINAHL, BIOSIS, Web of Science, The Cochrane Library, UKCRN portfolio, National Research Register Archive, Clinicaltrials.gov and OpenSIGLE were searched from database inception to 31st December 2010. A narrative synthesis of qualitative and quantitative data, based initially upon illness representations and extended to include other themes not compatible with that framework. Results: A range of clinically relevant beliefs was identified from 65 studies including the difficulty in labeling depression, complex causal factors instead of the biological model, the roles of different treatments and negative views about the consequences of depression. We found other important themes less related to ideas about illness: the existence of a self-sustaining depression spiral; depression as an existential state; the ambiguous status of suicidal thinking; and the role of stigma and blame in depression. Conclusions: Approaches to detection of depression in physical illness need to be receptive to the range of beliefs held by patients. Patient beliefs have implications for engagement with depression screening

Effective interaction between helical bio-molecules

The effective interaction between two parallel strands of helical bio-molecules, such as deoxyribose nucleic acids (DNA), is calculated using computer simulations of the "primitive" model of electrolytes. In particular we study a simple model for B-DNA incorporating explicitly its charge pattern as a double-helix structure. The effective force and the effective torque exerted onto the molecules depend on the central distance and on the relative orientation. The contributions of nonlinear screening by monovalent counterions to these forces and torques are analyzed and calculated for different salt concentrations. As a result, we find that the sign of the force depends sensitively on the relative orientation. For intermolecular distances smaller than $6\AA$ it can be both attractive and repulsive. Furthermore we report a nonmonotonic behaviour of the effective force for increasing salt concentration. Both features cannot be described within linear screening theories. For large distances, on the other hand, the results agree with linear screening theories provided the charge of the bio-molecules is suitably renormalized.Comment: 18 pages, 18 figures included in text, 100 bibliog

The Sandia Fracture Challenge: blind round robin predictions of ductile tearing

Existing and emerging methods in computational mechanics are rarely validated against problems with an unknown outcome. For this reason, Sandia National Laboratories, in partnership with US National Science Foundation and Naval Surface Warfare Center Carderock Division, launched a computational challenge in mid-summer, 2012. Researchers and engineers were invited to predict crack initiation and propagation in a simple but novel geometry fabricated from a common off-the-shelf commercial engineering alloy. The goal of this international Sandia Fracture Challenge was to benchmark the capabilities for the prediction of deformation and damage evolution associated with ductile tearing in structural metals, including physics models, computational methods, and numerical implementations currently available in the computational fracture community. Thirteen teams participated, reporting blind predictions for the outcome of the Challenge. The simulations and experiments were performed independently and kept confidential. The methods for fracture prediction taken by the thirteen teams ranged from very simple engineering calculations to complicated multiscale simulations. The wide variation in modeling results showed a striking lack of consistency across research groups in addressing problems of ductile fracture. While some methods were more successful than others, it is clear that the problem of ductile fracture prediction continues to be challenging. Specific areas of deficiency have been identified through this effort. Also, the effort has underscored the need for additional blind prediction-based assessments

Novel poly(phenylene vinylenes) with well-defined poly(ε-caprolactone) or polystyrene as lateral substituents: Synthesis and characterization

New macromonomers containing dialdehyde functionalities placed at the middle or at the end of the chains were synthesized in two reaction steps. First, using ring-opening polymerization (ROP) of ε-caprolactone (CL) or atom transfer radical polymerization (ATRP) of styrene (St) in the presence of proper initiators provided well-defined low molecular weight polymers with dibromobenzene moieties. In the second step, using Suzuki couplings of these dibromobenzene functions with 4-formylphenyl boronic acid, macromonomers having 4,4‘-dicarbaldehyde terphenyl moieties were obtained. Poly(phenylenevinylene)s (PPVs), with lateral subtituents PSt or PCL chains respectively, were synthesized by following a Wittig polycondensation in combination with bis(triphenylphosphonium) salts in the presence of potassium tert-butoxide. The resulting PPVs were soluble in common organic solvents at room temperature as were the starting macromonomers. All of the starting and intermediate polymers and the final PPVs were characterized by using 1H and 13C NMR, IR, GPC, DSC, and TGA measurements. Optical properties of the polymers were followed by UV and fluorescence spectroscopy. The studied PPVs show a blue or green fluorescence in solution

Mate recognition as a reproductive barrier in sexual and parthenogenetic Eucypris virens (Crustacea, Ostracoda)

Mate selection is one of the motors of evolution and of particular importance in the case of organisms in which sexual and parthenogenetic populations coexist. Sexual populations of the ostracod species complex Eucypris virens are often mixed with parthenogenetic ones. A powerful mate selection mechanism must exist to avoid time, energy and sperm loss, for the maintenance and success of sexual reproduction in these mixed populations. There are four types of E. virens individuals: males (diploid), sexual females (diploid) and asexual females (parthenogenetic and either di- or triploid). From one parthenogenetic population and two populations with males of E. virens, we sampled early stage juveniles, and reared them to adulthood in isolation. We combined three virgin ostracods, one male and two females, these latter of contrasting reproductive mode (sexual versus asexual) and origin (allopatric versus sympatric to the males). A posteriori molecular analyses further allowed identification of the mitochondrial clade and ploidy level of the individuals. Strong mate preferences were detected: sexual encounters occurred almost exclusively between males and sexual females and those involving asexual females (either di- or triploid) occurred rarely. The clear recognition of sexual individuals among each other implies that the presence of parthenogens does not greatly disturb the reproductive process in the sexual population. Moreover, this behaviour might play a role in the emergence and cohesiveness of cryptic species within E. virens. Although rare in small populations and at short timescales, copulations between males and asexual females support the hypothesis of hybrid origin for polyploidy