1,088 research outputs found
Testing the heterogeneity theory of late-life mortality plateaus by using cohorts of Drosophila melanogaster
Cognitive errors assessed by observer ratings in bipolar affective disorder: relationship with symptoms and therapeutic alliance
The construct of cognitive errors is clinically relevant for cognitive therapy of mood disorders. Beck's universality hypothesis postulates the relevance of negative cognitions in all subtypes of mood disorders, as well as positive cognitions for manic states. This hypothesis has rarely been empirically addressed for patients presenting bipolar affective disorder (BD). In-patients (n = 30) presenting with BD were interviewed, as were 30 participants of a matched control group. Valid and reliable observer-rater methodology for cognitive errors was applied to the session transcripts. Overall, patients make more cognitive errors than controls. When manic and depressive patients were compared, parts of the universality hypothesis were confirmed. Manic symptoms are related to positive and negative cognitive errors. These results are discussed with regard to the main assumptions of the cognitive model for depression; thus adding an argument for extending it to the BD diagnostic group, taking into consideration specificities in terms of cognitive errors. Clinical implications for cognitive therapy of BD are suggeste
secCl is a cys-loop ion channel necessary for the chloride conductance that mediates hormone-induced fluid secretion in Drosophila
Organisms use circulating diuretic hormones to control water balance (osmolarity), thereby avoiding dehydration and managing excretion of waste products. The hormones act through G-protein-coupled receptors to activate second messenger systems that in turn control the permeability of secretory epithelia to ions like chloride. In insects, the chloride channel mediating the effects of diuretic hormones was unknown. Surprisingly, we find a pentameric, cys-loop chloride channel, a type of channel normally associated with neurotransmission, mediating hormone-induced transepithelial chloride conductance. This discovery is important because: 1) it describes an unexpected role for pentameric receptors in the membrane permeability of secretory epithelial cells, and 2) it suggests that neurotransmitter-gated ion channels may have evolved from channels involved in secretion
New, but improved? Comparison between first and revised version of the Helping Alliance questionnaire
There is a consensus in the psychotherapy research field to consider the therapeutic alliance, broadly defined as the mutual collaboration between the therapist and the patient, as a robust and consistent predictor of therapy outcome. There is little agreement, however, on the best way to operationalise and measure it. Several instruments are available, each of them displaying some unique features so that investigators have problems to choose among them on the basis of considerations other than ease of administration, continuity with previous research or availability. One of the early self-report measures and widely used instruments was the Helping Alliance questionnaire (HAq-I) (Alexander and Luborsky, 1986). In recent years, we have become aware that it was limited by the presence of items that were explicitly assessing early symptomatic improvement and by the fact that all the items were worded positively. A revised version (HAq-II) was developed (Luborsky et al., 1996), guided by two main goals: (1) to reduce the inclination of the scale toward measuring early symptomatic improvement and thus confusing these two dimensions, and (2) to better incorporate the various aspects of the alliance related to the collaborative effort of patient and therapist. The new instrument includes 5 from the 11 items of the HAq-I and 14 new items - 5 of them worded negatively. The aim of the study is twofold: to validate the French version of the new HAq-II and to investigate empirically to what extent the HAq-II has improved over the HAq-I. The sample included 60 self-referred outpatients assigned to a Brief Psychodynamic Investigation (BPI), a manual-based investigation procedure in four sessions guided by psychodynamic principles. We looked at the correlation between the two HAq (I and II) and the Working Alliance Inventory (WAI), patient pretreatment characteristics (SCL-90, HDRS, HAMA, IIP) and outcome (SCL-90, SAS and patient satisfaction). Results showed that the French version of the HAq-II has good psychometric properties. Estimates of internal consistency and test-retest reliability were fairly similar to the original English version. Indication of its validity included high correlation with other alliance measures and independence from patient pretreatment characteristics. Surprisingly, HAq-II score predicted patient's satisfaction with the treatment but not symptomatic improvement. Taken together, these first results are promising and indicate that the translated version of the HAq-II is a valid instrument for measuring the helping alliance. Concerning the comparison between the two versions of the HAq, HAq-II has proved to be an improvement compared to the original HAq-I scale: it better relates to the alliance construct and it is less influenced by the symptoms of the patient. Considering also its better construct validity (Luborsky et al., 1996), we definitely recommend the use of the revised HAq-II instead of the initial version of the scale. (PsycINFO Database Record (c) 2006 APA, all rights reserved
RAID-2: Design and implementation of a large scale disk array controller
We describe the implementation of a large scale disk array controller and subsystem incorporating over 100 high performance 3.5 inch disk drives. It is designed to provide 40 MB/s sustained performance and 40 GB capacity in three 19 inch racks. The array controller forms an integral part of a file server that attaches to a Gb/s local area network. The controller implements a high bandwidth interconnect between an interleaved memory, an XOR calculation engine, the network interface (HIPPI), and the disk interfaces (SCSI). The system is now functionally operational, and we are tuning its performance. We review the design decisions, history, and lessons learned from this three year university implementation effort to construct a truly large scale system assembly
Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt
Sequestration of carbon by the marine biological pump depends on the processes that alter, remineralize, and preserve particulate organic carbon (POC) during transit to the deep ocean. Here, we present data collected from the Great Calcite Belt, a calcite-rich band across the Southern Ocean surface, to compare the transformation of POC in the euphotic and mesopelagic zones of the water column. The [superscript 234]Th-derived export fluxes and size-fractionated concentrations of POC, particulate inorganic carbon (PIC), and biogenic silica (BSi) were measured from the upper 1000 m of 27 stations across the Atlantic and Indian sectors of the Great Calcite Belt. POC export out of the euphotic zone was correlated with BSi export. PIC export was not, but did correlate positively with POC flux transfer efficiency. Moreover, regions of high BSi concentrations, which corresponded to regions with proportionally larger particles, exhibited higher attenuation of > 51 μm POC concentrations in the mesopelagic zone. The interplay among POC size partitioning, mineral composition, and POC attenuation suggests a more fundamental driver of POC transfer through both depth regimes in the Great Calcite Belt. In particular, we argue that diatom-rich communities produce large and labile POC aggregates, which not only generate high export fluxes but also drive more remineralization in the mesopelagic zone. We observe the opposite in communities with smaller calcifying phytoplankton, such as coccolithophores. We hypothesize that these differences are influenced by inherent differences in the lability of POC exported by different phytoplankton communities
Hemolytic anemia due to acute cytomegalovirus infection in an immunocompetent adult: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Cytomegalovirus is a common virus responsible for a wide range of clinical manifestations. Hemolysis is a rare but potentially life-threatening complication of cytomegalovirus infection, described mostly in immunocompromised patients, the pathogenesis of which is still unclear.</p> <p>We performed a review of the literature regarding cases of hemolytic anemia during acute cytomegalovirus infection in apparently immunocompetent individuals. We searched for relevant articles in PubMed for the period of 1980 through 2008.</p> <p>Case presentation</p> <p>We describe a case of Coombs-negative hemolytic anemia in a 44-year-old Caucasian immunocompetent man with acute cytomegalovirus infection.</p> <p>Conclusion</p> <p>Clinicians should consider cytomegalovirus infection in the differential diagnosis of hemolytic anemia in immunocompetent adults. Possible therapeutic options include antiviral therapy and steroids, although the best treatment strategy is still controversial.</p
DISTRIBUTION PATTERNS OF KEY FISH SPECIES OF THE SOUTHERN BENGUELA ECOSYSTEM: AN APPROACH COMBINING FISHERY-DEPENDENT AND FISHERY-INDEPENDENT DATA
Within the context of an ecosystem approach for fisheries, there is a need for quantitative information on distributions of key marine species. This information is valuable input for modelling species interactions in the southern Benguela ecosystem. In the present study, a method is described for mapping the density distribution of 15 key species: anchovy Engraulis encrasicolus, sardine Sardinops sagax, round herring Etrumeus whiteheadi, chub mackerel Scomber japonicus, horse mackerel Trachurus trachurus capensis, lanternfish Lampanyctodes hectoris, lightfish Maurolicus muelleri, albacore Thunnus alalunga, bigeye tuna Thunnus obesus, yellowfin tuna Thunnus albacares, silver kob Argyrosomus inodorus, snoek Thyrsites atun, Cape hake Merluccius spp., kingklip Genypterus capensis and chokka squid Loligo vulgaris reynaudi. The purpose was to make use of all available sources of data to extend the spatial and temporal coverage of the southern Benguela. Six sources of data were combined on a 10´ × 10´ cell grid in a Geographical Information System: acoustic and demersal surveys conducted by Marine and Coastal Management (MCM), and pelagic, demersal (including midwater trawl), hake-directed and tuna-directed longline commercial landings data collected by MCM. Comparisons of distributions between two periods (1980s and 1990s) and between two semesters (April –September and October–March) were conducted, but biases as a result of major differences in sampling strategy prevented detailed analysis for certain species. Maps of density distributions are nevertheless presented here and the method to determine them is discussed.Afr. J. mar. Sci. 26: 115–13
Osmotrophy of dissolved organic carbon by coccolithophores in darkness
• The evolutionary and ecological story of coccolithophores poses questions about their heterotrophy, surviving darkness after the end-Cretaceous asteroid impact as well as survival in the deep ocean twilight zone. Uptake of dissolved organic carbon might be an alternative nutritional strategy for supply of energy and carbon molecules.
• Using long-term batch culture experiments, we examined coccolithophore growth and maintenance on organic compounds in darkness. Radiolabeled experiments were performed to study the uptake kinetics. Pulse-chase experiments were used to examine the uptake into unassimilated, exchangeable pools versus assimilated, non-exchangeable pools.
• We found that coccolithophores were able to survive and maintain their metabolism for up to 30 days in darkness, accomplishing about one cell division. The concentration dependence for uptake was similar to the concentration dependence for growth in Cruciplacolithus neochelis, suggesting that it was taking up carbon compounds and immediately incorporating them into biomass. We recorded net incorporation of radioactivity into the particulate inorganic fraction.
• We conclude that osmotrophy provides nutritional flexibility and supports long-term survival in light levels well below threshold for photosynthesis. The incorporation of dissolved organic matter into particulate inorganic carbon, raises fundamental questions about the role of the alkalinity pump and the alkalinity balance in the sea
Dietary Mediators of the Genetic Susceptibility to Obesity—Results from the Quebec Family Study
BACKGROUND: Recent studies showed that eating behaviors such as disinhibition, emotional and external eating, and snacking mediate genetic susceptibility to obesity. It remains unknown if diet quality and intake of specific food groups also mediate the genetic susceptibility to obesity. OBJECTIVE: This study aimed to assess if diet quality and intakes of specific food groups mediate the association between a polygenic risk score (PRS) for BMI and BMI and waist circumference (WC). We hypothesized that poor diet quality, high intakes of energy-dense food groups, and low intakes of nutrient-dense food groups mediate the genetic susceptibility to obesity. METHODS: This cross-sectional study included 750 participants (56.3% women, aged 41.5 ± 14.9 y, BMI 27.8 ± 7.5 kg/m2) from the Quebec Family Study. A PRSBMI based on >500,000 genetic variants was calculated using LDpred2. Dietary intakes were assessed with a 3-d food record from which a diet quality score (i.e. Nutrient Rich Food Index 6.3) and food groups were derived. Mediation analyses were conducted using a regression-based and bootstrapping approach. RESULTS: The PRSBMI explained 25.7% and 19.8% of the variance in BMI and WC, respectively. The association between PRSBMI and BMI was partly mediated by poor diet quality (β = 0.33 ± 0.12; 95% CI: 0.13, 0.60), high intakes of fat and high-fat foods (β = 0.46 ± 0.16; 95% CI: 0.19, 0.79) and sugar-sweetened beverages (β = 0.25 ± 0.14; 95% CI: 0.05, 0.60), and low intakes of vegetables (β = 0.15 ± 0.08; 95% CI: 0.03, 0.32), fruits (β = 0.37 ± 0.12; 95% CI: 0.17, 0.64), and dairy products (β = 0.17 ± 0.09; 95% CI: 0.02, 0.37). The same trends were observed for WC. CONCLUSIONS: The genetic susceptibility to obesity was partly mediated by poor diet quality and intakes of specific food groups. These results suggest that improvement in diet quality may reduce obesity risk among individuals with high genetic susceptibility and emphasize the need to intervene on diet quality among these individuals
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