Conformational Dependence of a Protein Kinase Phosphate Transfer Reaction

Atomic motions and energetics for a phosphate transfer reaction catalyzed by the cAMP-dependent protein kinase (PKA) are calculated by plane-wave density functional theory, starting from structures of proteins crystallized in both the reactant conformation (RC) and the transition-state conformation (TC). In the TC, we calculate that the reactants and products are nearly isoenergetic with a 0.2 eV barrier; while phosphate transfer is unfavorable by over 1.2 eV in the RC, with an even higher barrier. With the protein in the TC, the motions involved in reaction are small, with only P$_\gamma$ and the catalytic proton moving more than 0.5 \AA. Examination of the structures reveals that in the RC the active site cleft is not completely closed and there is insufficient space for the phosphorylated serine residue in the product state. Together, these observations imply that the phosphate transfer reaction occurs rapidly and reversibly in a particular conformation of the protein, and that the reaction can be gated by changes of a few tenths of an \AA in the catalytic site.Comment: revtex4, 7 pages, 4 figures, to be submitted to Scienc

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Eating Behaviors of Older Adults Participating in Government-Sponsored Programs with Different Demographic Backgrounds

The purpose of this study was to determine the food behaviors of nutritionally high-risk seniors as a function of their racial background, gender, marital status, and education level. A total of 69 seniors were identified to be at high nutritional risk using the Nutrition Screening Initiative (NSI) checklist. A supplemental questionnaire (SQ) was created to examine the risk factors in relation to the participant’s demographic background. Key results indicated that Asians practiced healthy food behaviors and women were more likely to eat alone (p≤0.05). Married participants (90.9%) were most likely to consume 2 meals or more each day. College educated individuals practiced healthier eating, eating 5 servings or more of fruits and vegetables (p≤0.01) and 2 or more servings of milk and milk products (p≤0.01). These preliminary findings indicate that more studies should be conducted to focus on the demographic characteristics and food behaviors among older populations

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Chronic Exertional Compartment Syndrome: A Case Report about Claudication in a Healthy Adult

Claudication occurs when the blood supply is insufficient to service the musculature in the body with oxygen and metabolic waste management. A clinical complaint of claudication is commonly seen in primary care among older patients with vascular risk factors. A young and healthy patient presenting with claudication is less common and often results in delayed diagnosis with numerous extraneous diagnostic studies. This case discusses a young, healthy male patient with lower extremity symptoms that got worse with exercise and better with rest. He had normal physical exam findings leading to multiple diagnostic studies and over 12 months between the onset of symptoms and his return to full activity. Claudication can result from rare conditions, such as chronic exertional compartment syndrome, popliteal artery entrapment syndrome, fibromuscular dysplasia, and cystic adventitial disease. Symptomatic individuals with chronic exertional compartment syndrome experience reversible muscular pain from exercise-induced pressure, which increases within the finite spaces of any muscular compartment. Understanding the pathophysiology of exertional compartment syndrome and its related diagnoses allows for an organized diagnostic approach to young, healthy patients with claudication symptoms. This organized approach allows timely care, which is imperative for primary care physicians to reduce the number of tests performed, decrease the time to diagnosis, and reduce both the anxiety and cost for the patient. The approach presented herein can serve as a reminder of a proper work-up in similar patients and allow practitioners to identify the conditions that require intervention to improve outcomes

Problem-Solving Intervention for Caregivers of Children with Mental Health Problems

Building Our Solutions and Connections (BOSC) focused on enhancing problem-solving skills (PSS) of primary caregivers of children with mental health problems. Aims were determining feasibility, acceptability, and effect size (ES) estimates for depression, burden, personal control, and PSS. Methods—Caregivers were randomized to BOSC (n=30) or wait-list control (WLC) groups (n=31). Data were collected at baseline, post-intervention, and 3 and 6 months post-intervention. Results—Three-months post-intervention, ES for burden and personal control were .07 and .08, respectively. ES for depressed caregivers for burden and personal control were 0.14 and 0.19, respectively. Conclusions—Evidence indicates that the intervention had desired effects

The political phenomenology of war reporting

Drawing on interviews with war correspondents, editors, political and military personnel, this article investigates the political dimension of the structuration and structuring effects of the reporter’s experience of journalism. Self-reflection and judgements about colleagues confirm that there are dominant norms for interpreting and acting in conflict scenarios which, while contingent upon socio-historical context, are interpreted as natural. But the prevalence of such codes masks the systematically misrecognized symbolic systems of mystification and ambivalence – systems which reproduce hierarchies and gatekeeping structures in the field, but which are either experienced as unremarkable, dismissed with irony and cynicism, or not present to the consciousness of the war correspondent. The article builds on recent theories of journalistic disposition, ideology, discourse and professionalism, and describes the political dimension of journalistic practice perceived in the field as apolitical. It addresses the gendering of war correspondence, the rise of the journalist as moral authority, and questions the extent to which respondent reflections can be defensibly analytically determined

Solubility of nickel in slags equilibrated with Ni-S melt

To provide thermodynamic data for converting the nickel matte to liquid nickel, an experimental study was conducted in the phase equilibrium between the Ni-S melt and FeOX-SiO2, FeOX-CaO or CaO-Al2O3 based slag melted in a magnesia crucible at 1773 and 1873 K. pSO2 was controlled at 10.1 kPa while pO2 and pS2 ranged between those where NiO precipitated and Ni3S2 formed, respectively. The nickel content in the slag and the sulfur content in the metal at given pO2 and pS2 were smallest for the CaO-Al2O3 based slag. Both decreased with increasing temperature. At 1873 K, the content of nickel in the CaO-Al2O3 based slag at pO2 of 10 Pa (near the precipitation of NiO) was 4%, while the content of sulfur in alloy is 0.4 mass %. Thus, the CaO-Al2O3 base slag at 1873 K would be suitable for direct converting of Ni3S2 to metallic nickel. The distribution behavior of nickel between the slag and the Ni-S melt was discussed based on the concept of oxidic and sulfidic dissolution

Children with new onset seizures: A prospective study of parent variables, child behavior problems, and seizure occurrence

OBJECTIVE: Parent variables (stigma, mood, unmet needs for information and support, and worry) are associated with behavioral difficulties in children with seizures; however, it is not known how this relationship is influenced by additional seizures. This study followed children (ages 4-14 years) and their parents over a 24-month period (with data collected at baseline and 6, 12, and 24 months) and investigated the effect of an additional seizure on the relationship between parenting variables and child behavior difficulties. METHODS: The sample was parents of 196 children (104 girls and 92 boys) with a first seizure within the past 6 weeks. Child mean age at baseline was 8 years, 3 months (SD 3 years). Data were analyzed using t-tests, chi-square tests, and repeated measures analyses of covariance. RESULTS: Relationships between parent variables, additional seizures, and child behavior problems were consistent across time. Several associations between parent variables and child behavior problems were stronger in the additional seizure group than in the no additional seizure group. CONCLUSIONS: Findings suggest that interventions that assist families to respond constructively to the reactions of others regarding their child's seizure condition and to address their needs for information and support could help families of children with continuing seizures to have an improved quality of life