1,512 research outputs found

    Effects of Threat and Sleep Deprivation on Action Tendencies and Response Inhibition

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    The ability to control action is crucial for adaptive responding, but may be compromised in situations involving strong emotions (e.g., threat) or when people are deprived of resources (e.g., sleep). As compromised action control can have large consequences in threatening situations, for example when police officers face a potentially armed suspect, we experimentally investigated how acute threat and partial sleep deprivation affect the ability to control impulsive responses, in 52 healthy young adults performing a simulated shooting task. The results showed that acute threat increased the tendency to act quickly (i.e., reduced response times; Coef = 9.46, 95% CI [3.49, 15.29], p = .001) and impaired response inhibition (i.e., increased stop signal reaction times; Coef = -4.91, 95% CI [-9.47, -0.44], p = .035). In addition, three nights of partial sleep deprivation (five hours [n = 28] vs. eight hours [n = 24] of sleep), led to a significant decrease in overall response accuracy (Coef = -0.22, 95% CI [- 0.40, -0.05], p = .025). Contrary to expectations, our results did not show increased threat sensitivity in sleep-deprived individuals (all p > .13). Nevertheless, they may have important implications for professionals who are required to maintain behavioral control under high levels of threat and who experience disturbed sleep due to e.g. shift work, as both factors negatively affected performanc

    The 18S ribosomal RNA sequence of the sea anemone <i>Ammonia sulcata</i> and its evolutionary position among other eukaryotes

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    Evolutionary trees based on partial small ribosomal subunit RNA sequences of 22 metazoa species have been published [(1988) Science 239, 748-753]. In these trees, cnidarians (Radiata) seemed to have evolved independently from the Bilateria, which is in contradiction with the general evolutionary view. In order to further investigate this problem, the complete srRNA sequence of the sea anemone Ammonia sulcata was determined and evolutionary trees were constructed using a matrix optimization method. In the tree thus obtained the sea anemone and Bilateria together form a monophyletic cluster, with the sea anemone forming the first line of descent of the metazoan group

    Vaginal yeast infections in diabetic women

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    Two hundred and three diabetic women (89 with and 114 without genital symptoms) were examined for the presence of yeasts and Trichomonas vaginalis. Yeasts were isolated from the vaginas of 35,5% of patients and were more common in the symptomatic group (48,0%) than the asymptomatic group (25,4%; P &lt; 0,(5). Candida albicans was isolated from 12,8% of all patients and showed a significant association with pruritus vulvae (P &lt; 0,(5). A significant association was also shown between the presence of yeasts in the rectum and in the vagina. C. glabrata (Torulopsis glabrata) was the COmDlonest yeast species isolated (50,0%), with C. albicans the next most frequent (36,1%). T. vaginalis infection was present in 14,3% of all subjects

    Plasmodium knowlesi malaria in Vietnam: some clarifications

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    A recently published comment on a report of Plasmodium knowlesi infections in Vietnam states that this may not accurately represent the situation in the study area because the PCR primers used may cross-hybridize with Plasmodium vivax. Nevertheless, P. knowlesi infections have been confirmed by sequencing. In addition, a neighbour-joining tree based on the 18S S-Type SSUrRNA gene shows that the Vietnamese samples clearly cluster with the P. knowlesi isolates identified in Malaysia and are distinct from the corresponding P. vivax sequences. All samples came from asymptomatic individuals who did not consult for fever during the months preceding or following the survey, indicating that asymptomatic P. knowlesi infections occur in this population, although this does not exclude the occurrence of symptomatic cases. Large-scale studies to determine the extent and the epidemiology of P. knowlesi malaria in Vietnam are further needed

    Clinical and Molecular Characteristics and Outcome of Cystic Partially Differentiated Nephroblastoma and Cystic Nephroma: A Narrative Review of the Literature

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    In children presenting with a predominantly cystic renal tumor, the most likely diagnoses include cystic partially differentiated nephroblastoma (CPDN) and cystic nephroma (CN). Both entities are rare and limited information on the clinical and molecular characteristics, treatment, and outcome is available since large cohort studies are lacking. We performed an extensive literature review, in which we identified 113 CPDN and 167 CN. The median age at presentation for CPDN and CN was 12 months (range: 3 weeks–4 years) and 16 months (prenatal diagnosis–16 years), respectively. No patients presented with metastatic disease. Bilateral disease occurred in both entities. Surgery was the main treatment for both. Two/113 CPDN patients and 26/167 CN patients had previous, concomitant, or subsequent other tumors. Unlike CPDN, CN was strongly associated with somatic (n = 27/29) and germline (n = 12/12) DICER1-mutations. Four CPDN patients and one CN patient relapsed. Death was reported in six/103 patients with CPDN and six/118 CN patients, none directly due to disease. In conclusion, children with CPDN and CN are young, do not present with metastases, and have an excellent outcome. Awareness of concomitant or subsequent tumors and genetic testing is important. International registration of cystic renal tumor cohorts is required to enable a better understanding of clinical and genetic characteristics

    Post-contrast acute kidney injury \u2013 Part 1: Definition, clinical features, incidence, role of contrast medium and risk factors: Recommendations for updated ESUR Contrast Medium Safety Committee guidelines

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    Purpose: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 2011 guidelines on the prevention of post-contrast acute kidney injury (PC-AKI). The results of the literature review and the recommendations based on it, which were used to prepare the new guidelines, are presented in two papers. Areas covered in part 1: Topics reviewed include the terminology used, the best way to measure eGFR, the definition of PC-AKI, and the risk factors for PC-AKI, including whether the risk with intravenous and intra-arterial contrast medium differs. Key Points: \u2022 PC-AKI is the preferred term for renal function deterioration after contrast medium. \u2022 PC-AKI has many possible causes. \u2022 The risk of AKI caused by intravascular contrast medium has been overstated. \u2022 Important patient risk factors for PC-AKI are CKD and dehydration

    Post-contrast acute kidney injury. Part 2: risk stratification, role of hydration and other prophylactic measures, patients taking metformin and chronic dialysis patients: Recommendations for updated ESUR Contrast Medium Safety Committee guidelines

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    Objectives: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 2011 guidelines on the prevention of post-contrast acute kidney injury (PC-AKI). The results of the literature review and the recommendations based on it, which were used to prepare the new guidelines, are presented in two papers. Areas covered in part 2: Topics reviewed include stratification of PC-AKI risk, the need to withdraw nephrotoxic medication, PC-AKI prophylaxis with hydration or drugs, the use of metformin in diabetic patients receiving contrast medium and the need to alter dialysis schedules in patients receiving contrast medium. Key points: \u2022 In CKD, hydration reduces the PC-AKI risk \u2022 Intravenous normal saline and intravenous sodium bicarbonate provide equally effective prophylaxis \u2022 No drugs have been consistently shown to reduce the risk of PC-AKI \u2022 Stop metformin from the time of contrast medium administration if eGFR < 30 ml/min/1.73 m2 \u2022 Dialysis schedules need not change when intravascular contrast medium is given

    A lipocalin mediates unidirectional heme biomineralization in malaria parasites.

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    During blood-stage development, malaria parasites are challenged with the detoxification of enormous amounts of heme released during the proteolytic catabolism of erythrocytic hemoglobin. They tackle this problem by sequestering heme into bioinert crystals known as hemozoin. The mechanisms underlying this biomineralization process remain enigmatic. Here, we demonstrate that both rodent and human malaria parasite species secrete and internalize a lipocalin-like protein, PV5, to control heme crystallization. Transcriptional deregulation of PV5 in the rodent parasite Plasmodium berghei results in inordinate elongation of hemozoin crystals, while conditional PV5 inactivation in the human malaria agent Plasmodium falciparum causes excessive multidirectional crystal branching. Although hemoglobin processing remains unaffected, PV5-deficient parasites generate less hemozoin. Electron diffraction analysis indicates that despite the distinct changes in crystal morphology, neither the crystalline order nor unit cell of hemozoin are affected by impaired PV5 function. Deregulation of PV5 expression renders P. berghei hypersensitive to the antimalarial drugs artesunate, chloroquine, and atovaquone, resulting in accelerated parasite clearance following drug treatment in vivo. Together, our findings demonstrate the Plasmodium-tailored role of a lipocalin family member in hemozoin formation and underscore the heme biomineralization pathway as an attractive target for therapeutic exploitation

    Validating module network learning algorithms using simulated data

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    In recent years, several authors have used probabilistic graphical models to learn expression modules and their regulatory programs from gene expression data. Here, we demonstrate the use of the synthetic data generator SynTReN for the purpose of testing and comparing module network learning algorithms. We introduce a software package for learning module networks, called LeMoNe, which incorporates a novel strategy for learning regulatory programs. Novelties include the use of a bottom-up Bayesian hierarchical clustering to construct the regulatory programs, and the use of a conditional entropy measure to assign regulators to the regulation program nodes. Using SynTReN data, we test the performance of LeMoNe in a completely controlled situation and assess the effect of the methodological changes we made with respect to an existing software package, namely Genomica. Additionally, we assess the effect of various parameters, such as the size of the data set and the amount of noise, on the inference performance. Overall, application of Genomica and LeMoNe to simulated data sets gave comparable results. However, LeMoNe offers some advantages, one of them being that the learning process is considerably faster for larger data sets. Additionally, we show that the location of the regulators in the LeMoNe regulation programs and their conditional entropy may be used to prioritize regulators for functional validation, and that the combination of the bottom-up clustering strategy with the conditional entropy-based assignment of regulators improves the handling of missing or hidden regulators.Comment: 13 pages, 6 figures + 2 pages, 2 figures supplementary informatio

    Functional significance may underlie the taxonomic utility of single amino acid substitutions in conserved proteins

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    We hypothesized that some amino acid substitutions in conserved proteins that are strongly fixed by critical functional roles would show lineage-specific distributions. As an example of an archetypal conserved eukaryotic protein we considered the active site of ß-tubulin. Our analysis identified one amino acid substitution—ß-tubulin F224—which was highly lineage specific. Investigation of ß-tubulin for other phylogenetically restricted amino acids identified several with apparent specificity for well-defined phylogenetic groups. Intriguingly, none showed specificity for “supergroups” other than the unikonts. To understand why, we analysed the ß-tubulin Neighbor-Net and demonstrated a fundamental division between core ß-tubulins (plant-like) and divergent ß-tubulins (animal and fungal). F224 was almost completely restricted to the core ß-tubulins, while divergent ß-tubulins possessed Y224. Thus, our specific example offers insight into the restrictions associated with the co-evolution of ß-tubulin during the radiation of eukaryotes, underlining a fundamental dichotomy between F-type, core ß-tubulins and Y-type, divergent ß-tubulins. More broadly our study provides proof of principle for the taxonomic utility of critical amino acids in the active sites of conserved proteins
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