On the Temperature Dependence of the Rate Constant of the Bimolecular Reaction of Two Hydrated Electrons

It has been a longstanding issue in the radiation chemistry of water that, even though H2 is a molecular product, its “escape” yield g(H2) increases with increasing temperature. A main source of H2 is the bimolecular reaction of two hydrated electrons (e-aq). The temperature dependence of the rate constant of this reaction (k1), measured under alkaline conditions, reveals that the rate constant drops abruptly above ~150°C. Recently, it has been suggested that this temperature dependence should be regarded as being independent of pH and used in high-temperature modeling of near-neutral water radiolysis. However, when this drop in the e-aq self-reaction rate constant is included in low (isolated spurs) and high (cylindrical tracks) linear energy transfer (LET) modeling calculations, g(H2) shows a marked downward discontinuity at ~150°C which is not observed experimentally. The consequences of the presence of this discontinuity in g(H2) for both low and high LET radiation are briefly discussed in this communication. It is concluded that the applicability of the sudden drop in k1 observed at ~150°C in alkaline water to near-neutral water is questionable and that further measurements of the rate constant in pure water are highly desirable.Received:13 June 2013; Revised: 27 August 2013; Accepted: 28 August 201

Primary hyperparathyroidism in children, adolescents, and young adults

Primary hyperparathyroidism (HPT) is considered a rare disease in children and an uncommon one in adolescents and young adults. Until 1975, only 60 children under the age of 16 years had been reported with proven HPT. Most had symptoms of weakness, irritability, anorexia, and weight loss. Severe hypercalcemia (serum calcium>15 mg/ 100 ml) and radiologic evidence of bone changes were common findings, and suggested delayed diagnoses . This report is based on the clinical and laboratory findings in 53 young patients with proven primary HPT (range: 1–30 years of age) from 1971 to 1980, treated in one hospital. There were 29 male and 24 female patients, 26 of whom developed symptoms before age 18. Common symptoms included hematuria and renal colic (50%), renal calculi (50%), and hypertension with (6%) and without (3%) severe headaches. Although 64.2% of patients had adenomas, only 54% of patients under 18, and as many as 77.8% over 18, had them. The incidence of hyperplasia was markedly increased in the patients under 18 (38%) as compared to the patients over 18 (18.5%) or the group taken as a whole (30.2%). The following associated diseases were identified: MEA I syndrome (4); MEA II syndrome (4); von Recklinghausen's neurofibromatosis; papillary carcinoma of thyroid; craniopharyngioma; and multiple metaphyseal chondromatosis. One child had hereditary neonatal parathyroid hyperplasia . Primary hyperparathyroidism is more common than previously suspected in young people. Symptoms of renal stones, hypertension, persistent headaches, unexplained anorexia, and weight loss should prompt evaluation for primary HPT. If hyperplasia is found, the patient and family should be investigated for associated endocrinopathies . L'hyperparathyroïdie est considérée une maladie extraordinaire des infants et bien rare des adolescents et des jeunes adultes. Jusqu'à 1975, seulement 60 enfants qui avaient moins de 16 ans étaient rapportés avec l'hyperparathyroïdie verifiée. La majorité avaient les symptômes de faiblesse, irritabilité, anorexie et perdu des poids. L'hypercalcémie severe (calcémies > 15 mg/100 ml) et l'évidence radiologique d'abnormalitiés osseux sont les conclusions ordinaires, et cela donne l'idée que le diagnostic était tard.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41310/1/268_2005_Article_BF01655371.pd

A synthesis of evidence for policy from behavioural science during COVID-19

Scientific evidence regularly guides policy decisions1, with behavioural science increasingly part of this process2. In April 2020, an influential paper3 proposed 19 policy recommendations (‘claims’) detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandemic-related research articles that empirically investigated those claims. We report the scale of evidence and whether evidence supports them to indicate applicability for policymaking. Two independent teams, involving 72 reviewers, found evidence for 18 of 19 claims, with both teams finding evidence supporting 16 (89%) of those 18 claims. The strongest evidence supported claims that anticipated culture, polarization and misinformation would be associated with policy effectiveness. Claims suggesting trusted leaders and positive social norms increased adherence to behavioural interventions also had strong empirical support, as did appealing to social consensus or bipartisan agreement. Targeted language in messaging yielded mixed effects and there were no effects for highlighting individual benefits or protecting others. No available evidence existed to assess any distinct differences in effects between using the terms ‘physical distancing’ and ‘social distancing’. Analysis of 463 papers containing data showed generally large samples; 418 involved human participants with a mean of 16,848 (median of 1,699). That statistical power underscored improved suitability of behavioural science research for informing policy decisions. Furthermore, by implementing a standardized approach to evidence selection and synthesis, we amplify broader implications for advancing scientific evidence in policy formulation and prioritization

Partitioning the Heritability of Tourette Syndrome and Obsessive Compulsive Disorder Reveals Differences in Genetic Architecture

The direct estimation of heritability from genome-wide common variant data as implemented in the program Genome-wide Complex Trait Analysis (GCTA) has provided a means to quantify heritability attributable to all interrogated variants. We have quantified the variance in liability to disease explained

PCR-heterodúplex por agrupamiento: Implementación de un método de identificación de portadores de la mutación más común causal de fibrosis quística en Colombia

"Background: Cystic fibrosis (CF) is the most frequent autosomal recessive disorder in the Caucasian population with an incidence of 1 in 2,500 newborns. More than 1,300 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that causes CF have been described. However, mutation F508del is the most common mutation in different populations around the world. Objective: To develop a fast, reliable and low-cost technique to screen carriers and affected individuals for the F508del mutation. This kind of analysis will have an impact on genetic counselling to decrease the incidence of new cases, in the early diagnosis and instauration of appropriate treatment to decrease morbidity and mortality associated to CF in Colombia. Methods: The reliability of the PCR-heteroduplex by grouping technique by analysis of 400 blood spot samples from asymptomatic CF patients was defined. Results: Using PCR-heteroduplex by grouping technique 100% efficiency, reproducibility and specificity and 92%sensitivity were found. Conclusions: The sensitivity and reproducibility of the PCR-heteroduplex by grouping technique up to pooling of 10 samples were demonstrated. This kind of analysis could be used in heterozygotes and affected screening programs. © 2006 Corporación Editora Médica del Valle.

PCR-heterodúplex por agrupamiento: Implementación de un método de identificación de portadores de la mutación más común causal de fibrosis quística en Colombia

Background: Cystic fibrosis (CF) is the most frequent autosomal recessive disorder in the Caucasian population with an incidence of 1 in 2,500 newborns. More than 1,300 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that causes CF have been described. However, mutation F508del is the most common mutation in different populations around the world. Objective: To develop a fast, reliable and low-cost technique to screen carriers and affected individuals for the F508del mutation. This kind of analysis will have an impact on genetic counselling to decrease the incidence of new cases, in the early diagnosis and instauration of appropriate treatment to decrease morbidity and mortality associated to CF in Colombia. Methods: The reliability of the PCR-heteroduplex by grouping technique by analysis of 400 blood spot samples from asymptomatic CF patients was defined. Results: Using PCR-heteroduplex by grouping technique 100% efficiency, reproducibility and specificity and 92%sensitivity were found. Conclusions: The sensitivity and reproducibility of the PCR-heteroduplex by grouping technique up to pooling of 10 samples were demonstrated. This kind of analysis could be used in heterozygotes and affected screening programs. © 2006 Corporación Editora Médica del Valle