184 research outputs found
Acclimatization of the crustose coralline alga Porolithon onkodes to variable pCO2
Ocean acidification (OA) has important implications for the persistence of coral reef ecosystems, due to potentially negative effects on biomineralization. Many coral reefs are dynamic with respect to carbonate chemistry, and experience fluctuations in pCO2 that exceed OA projections for the near future. To understand the influence of dynamic pCO2 on an important reef calcifier, we tested the response of the crustose coralline alga Porolithon onkodes to oscillating pCO2. Individuals were exposed to ambient (400 ??atm), high (660 ??atm), or variable pCO2 (oscillating between 400/660 ??atm) treatments for 14 days. To explore the potential for coralline acclimatization, we collected individuals from low and high pCO2 variability sites (upstream and downstream respectively) on a back reef characterized by unidirectional water flow in Moorea, French Polynesia. We quantified the effects of treatment on algal calcification by measuring the change in buoyant weight, and on algal metabolism by conducting sealed incubations to measure rates of photosynthesis and respiration. Net photosynthesis was higher in the ambient treatment than the variable treatment, regardless of habitat origin, and there was no effect on respiration or gross photosynthesis. Exposure to high pCO2 decreased P. onkodes calcification by >70%, regardless of the original habitat. In the variable treatment, corallines from the high variability habitat calcified 42% more than corallines from the low variability habitat. The significance of the original habitat for the coralline calcification response to variable, high pCO2 indicates that individuals existing in dynamic pCO2 habitats may be acclimatized to OA within the scope of in situ variability. These results highlight the importance of accounting for natural pCO2 variability in OA manipulations, and provide insight into the potential for plasticity in habitat and species-specific responses to changing ocean chemistry.Funding was provided by grants from the National Science Foundation (OCE-0417412, OCE-10-26852, OCE-1041270) and gifts from the Gordon and Betty Moore Foundation. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript
Hyperthyroidism related to McCune-Albright syndrome: report of two cases and review of the literature
INTRODUCTION: McCune-Albright syndrome is a sporadic disease clinicaly characterized by polyostotic fibrous dysplasia, café-au-lait cutaneous spots and hyperfunctional endocrinopathies, such as precocious puberty, hyperthyroidism, acromegaly and others. The biologic physiopathology of the disease is based on an activating mutation of the gene for the Gs protein which mediates the activation of adenyl cyclase and subsequent gland autonomous secretion. The thyroid gland is usually involved in this disease, being hyperthyroidism the second most common endocrinopathy seen after precocious puberty. OBJECTIVE: Revision of the literature since 1937 to 1997, adding our casuistic and discussing the adequate treatment for the hyperthyroidism in the syndrome. RESULTS: Among 85 cases identified with the syndrome, hyperthyroidism treatment was described in 26 of them. Fifteen were submitted to surgery (total thyroidectomy), 6 were submitted to iodotherapy and 5 were treated with antithyroid drugs (ATD - propylthiouracil, carbimazole or methimazole). In some cases, treatment association was done. CONCLUSION: McCune-Albright syndrome is a rare disease, combining polyostotic fibrous dysplasia, café-au-lait cutaneous spots and hyperfunctional endocrinopathies. Cases with hyperthyroidism are treated iniatially clinically, but definitive ablation with surgery or radioiodine treatment is the most indicated option.INTRODUÇÃO: A síndrome de McCune Albright é uma doença rara, clinicamente definida pela combinação de displasia fibrosa poliostótica, manchas café-com-leite e endocrinopatias com hiperfunção, como puberdade precoce, hipertireoidismo, acromegalia e outras. A fisiopatologia biomolecular baseia-se em uma mutação ativadora do gene para a subunidade alfa da proteína de membrana Gs, que estimula a produção intracelular de AMPc, conferindo secreção autônoma à glândula em particular. A glândula tireóide é freqüentemente envolvida nesta doença, sendo o hipertireoidismo a segunda endocrinopatia mais comum após a puberdade precoce. OBJETIVO: Realizar uma revisão da literatura no período de 1937 a 1997, incluindo nossa casuística, e discutir o tratamento utilizado para o hipertireoidismo nesta síndrome. RESULTADOS: Do total de 85 casos, em 26 com hipertireoidismo se descreve o tipo de tratamento utilizado. Entre esses, 15 foram submetidos à cirurgia (tireoidectomia total), seis foram submetidos à iodoterapia e cinco foram submetidos a tratamento com drogas antitireoidianas (DAT - propiltiuracil, carbimazol ou metimazol), pois em alguns houve associação dos tratamentos citados anteriormente. CONCLUSÃO: A síndrome de McCune-Albright é uma doença rara, que inclui displasia fibrosa poliostótica, manchas café-com-leite e endocrinopatias com hiperfunção. Os casos acompanhados com hipertireoidismo são inicialmente tratados clinicamente com DAT, porém a ablação cirúrgica ou com radioiodoterapia é a opção definitiva mais indicada.Universidade Federal de São Paulo (UNIFESP) Departamento de Otorrinolaringologia e Cirurgia de Cabeça e PescoçoUNIFESP, Depto. de Otorrinolaringologia e Cirurgia de Cabeça e PescoçoSciEL
Low level constraints on dynamic contour path integration
Contour integration is a fundamental visual process. The constraints on integrating
discrete contour elements and the associated neural mechanisms have typically been
investigated using static contour paths. However, in our dynamic natural environment
objects and scenes vary over space and time. With the aim of investigating the
parameters affecting spatiotemporal contour path integration, we measured human
contrast detection performance of a briefly presented foveal target embedded in
dynamic collinear stimulus sequences (comprising five short 'predictor' bars appearing
consecutively towards the fovea, followed by the 'target' bar) in four experiments. The
data showed that participants' target detection performance was relatively unchanged
when individual contour elements were separated by up to 2° spatial gap or 200ms
temporal gap. Randomising the luminance contrast or colour of the predictors, on the
other hand, had similar detrimental effect on grouping dynamic contour path and
subsequent target detection performance. Randomising the orientation of the
predictors reduced target detection performance greater than introducing misalignment
relative to the contour path. The results suggest that the visual system integrates
dynamic path elements to bias target detection even when the continuity of path is
disrupted in terms of spatial (2°), temporal (200ms), colour (over 10 colours) and
luminance (-25% to 25%) information. We discuss how the findings can be largely
reconciled within the functioning of V1 horizontal connections
Patients' opinion on the barriers to diabetes control in areas of conflicts: The Iraqi example
<p>Abstract</p> <p>Background</p> <p>The health system in Iraq has undergone progressive decline since the embargo that followed the second gulf war in 1991. The aim of this study is to see barriers to glycemic control form the patient perspective, in a diabetic clinic in the south of Iraq.</p> <p>Methods</p> <p>A cross sectional study from the diabetes out-patient clinic in Al-Faiha general hospital in Basrah, South Iraq for the period from January to December 2007. The study includes diabetic patients whether type 1 or 2 if they have at least one year of follow up in the same clinic. Those with A1C ≥ 7% were interviewed by special questionnaire, that was filled in by the medical staff of the clinic. The subjects analyzed in this study were adults (≥ 18 years old) with previously diagnosed diabetes (n = 3522). The duration of diabetes range from 1 to 30 years.</p> <p>Results</p> <p>Mean A1C was 8.4 ± 2 percent, with 835(23.7%) patients with A1C less than 7% and 2688(76.3%) equal to or more than 7%. Of 3522 studied patients, 46.6% were men and 51.5% were women, with mean age of 53.78 ± 12.81 year and age range 18–97 years. Patient opinion for not achieving good glycemic control among 2688 patients with HbA1C ≥ 7% included the following. No drug supply from primary health care center (PHC) or drug shortage is a cause in 50.8% of cases, while drugs and or laboratory expense were the cause in 50.2%. Thirty point seven percent of patients said that they were unaware of diabetics complications and 20.9% think that diabetes is an untreatable disease. Thirty percent think that non-control of their diabetes is due to migration after the war. No electricity or erratic electricity, self-monitoring of blood glucose (SMBG) is not available, or strips were not available or could not be used, and illiteracy as a cause was seen in 15%, 10.8% and 9.9% respectively.</p> <p>Conclusion</p> <p>Our patients with diabetes mellitus declared that of the causes for poor glycemic control most of them related to the current health situation in Iraq.</p
The supernatural characters and powers of sacred trees in the Holy Land
This article surveys the beliefs concerning the supernatural characteristics and powers of sacred trees in Israel; it is based on a field study as well as a survey of the literature and includes 118 interviews with Muslims and Druze. Both the Muslims and Druze in this study attribute supernatural dimensions to sacred trees which are directly related to ancient, deep-rooted pagan traditions. The Muslims attribute similar divine powers to sacred trees as they do to the graves of their saints; the graves and the trees are both considered to be the abode of the soul of a saint which is the source of their miraculous powers. Any violation of a sacred tree would be strictly punished while leaving the opportunity for atonement and forgiveness. The Druze, who believe in the transmigration of souls, have similar traditions concerning sacred trees but with a different religious background. In polytheistic religions the sacred grove/forest is a centre of the community's official worship; any violation of the trees is regarded as a threat to the well being of the community. Punishments may thus be collective. In the monotheistic world (including Christianity, Islam and Druze) the pagan worship of trees was converted into the worship/adoration of saints/prophets; it is not a part of the official religion but rather a personal act and the punishments are exerted only on the violating individual
Incremental grouping of image elements in vision
One important task for the visual system is to group image elements that belong to an object and to segregate them from other objects and the background. We here present an incremental grouping theory (IGT) that addresses the role of object-based attention in perceptual grouping at a psychological level and, at the same time, outlines the mechanisms for grouping at the neurophysiological level. The IGT proposes that there are two processes for perceptual grouping. The first process is base grouping and relies on neurons that are tuned to feature conjunctions. Base grouping is fast and occurs in parallel across the visual scene, but not all possible feature conjunctions can be coded as base groupings. If there are no neurons tuned to the relevant feature conjunctions, a second process called incremental grouping comes into play. Incremental grouping is a time-consuming and capacity-limited process that requires the gradual spread of enhanced neuronal activity across the representation of an object in the visual cortex. The spread of enhanced neuronal activity corresponds to the labeling of image elements with object-based attention
Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma
Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearson’s chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ± 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33–41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, χ2P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05–5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available
DNA damage by lipid peroxidation products: implications in cancer, inflammation and autoimmunity
Oxidative stress and lipid peroxidation (LPO) induced by inflammation, excess metal storage and excess caloric intake cause generalized DNA damage, producing genotoxic and mutagenic effects. The consequent deregulation of cell homeostasis is implicated in the pathogenesis of a number of malignancies and degenerative diseases. Reactive aldehydes produced by LPO, such as malondialdehyde, acrolein, crotonaldehyde and 4-hydroxy-2-nonenal, react with DNA bases, generating promutagenic exocyclic DNA adducts, which likely contribute to the mutagenic and carcinogenic effects associated with oxidative stress-induced LPO. However, reactive aldehydes, when added to tumor cells, can exert an anticancerous effect. They act, analogously to other chemotherapeutic drugs, by forming DNA adducts and, in this way, they drive the tumor cells toward apoptosis. The aldehyde-DNA adducts, which can be observed during inflammation, play an important role by inducing epigenetic changes which, in turn, can modulate the inflammatory process. The pathogenic role of the adducts formed by the products of LPO with biological macromolecules in the breaking of immunological tolerance to self antigens and in the development of autoimmunity has been supported by a wealth of evidence. The instrumental role of the adducts of reactive LPO products with self protein antigens in the sensitization of autoreactive cells to the respective unmodified proteins and in the intermolecular spreading of the autoimmune responses to aldehyde-modified and native DNA is well documented. In contrast, further investigation is required in order to establish whether the formation of adducts of LPO products with DNA might incite substantial immune responsivity and might be instrumental for the spreading of the immunological responses from aldehyde-modified DNA to native DNA and similarly modified, unmodified and/or structurally analogous self protein antigens, thus leading to autoimmunity
Lawson criterion for ignition exceeded in an inertial fusion experiment
For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion
Cardiometabolic Risk Factor Changes Observed in Diabetes Prevention Programs in US Settings: A Systematic Review and Meta-analysis
Background: The Diabetes Prevention Program (DPP) study showed that weight loss in high-risk adults lowered diabetes incidence and cardiovascular disease risk. No prior analyses have aggregated weight and cardiometabolic risk factor changes observed in studies implementing DPP interventions in nonresearch settings in the United States. Methods and Findings: In this systematic review and meta-analysis, we pooled data from studies in the United States implementing DPP lifestyle modification programs (focused on modest [5%–7%] weight loss through ≥150 min of moderate physical activity per week and restriction of fat intake) in clinical, community, and online settings. We reported aggregated pre- and post-intervention weight and cardiometabolic risk factor changes (fasting blood glucose [FBG], glycosylated hemoglobin [HbA1c], systolic or diastolic blood pressure [SBP/DBP], total [TC] or HDL-cholesterol). We searched the MEDLINE, EMBASE, Cochrane Library, and Clinicaltrials.gov databases from January 1, 2003, to May 1, 2016. Two reviewers independently evaluated article eligibility and extracted data on study designs, populations enrolled, intervention program characteristics (duration, number of core and maintenance sessions), and outcomes. We used a random effects model to calculate summary estimates for each outcome and associated 95% confidence intervals (CI). To examine sources of heterogeneity, results were stratified according to the presence of maintenance sessions, risk level of participants (prediabetes or other), and intervention delivery personnel (lay or professional). Forty-four studies that enrolled 8,995 participants met eligibility criteria. Participants had an average age of 50.8 years and body mass index (BMI) of 34.8 kg/m2, and 25.2% were male. On average, study follow-up was 9.3 mo (median 12.0) with a range of 1.5 to 36 months; programs offered a mean of 12.6 sessions, with mean participant attendance of 11.0 core sessions. Sixty percent of programs offered some form of post-core maintenance (either email or in person). Mean absolute changes observed were: weight -3.77 kg (95% CI: -4.55; -2.99), HbA1c -0.21% (-0.29; -0.13), FBG -2.40 mg/dL (-3.59; -1.21), SBP -4.29 mmHg (-5.73, -2.84), DBP -2.56 mmHg (-3.40, 1.71), HDL +0.85 mg/dL (-0.10, 1.60), and TC -5.34 mg/dL (-9.72, -0.97). Programs with a maintenance component achieved greater reductions in weight (additional -1.66kg) and FBG (additional -3.14 mg/dl). Findings are subject to incomplete reporting and heterogeneity of studies included, and confounding because most included studies used pre-post study designs. Conclusions: DPP lifestyle modification programs achieved clinically meaningful weight and cardiometabolic health improvements. Together, these data suggest that additional value is gained from these programs, reinforcing that they are likely very cost-effective
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