Augmented Cardiopulmonary Baroreflex Sensitivity in Intradialytic Hypertension.

IntroductionEnd-stage renal disease (ESRD) patients with a paradoxical increase in blood pressure (BP) during hemodialysis (HD), termed intradialytic hypertension (ID-HTN), are at significantly increased risk for mortality and adverse cardiovascular events. ID-HTN affects up to 15% of all HD patients, and the pathophysiologic mechanisms remain unknown. We hypothesized that ESRD patients prone to ID-HTN have heightened volume-sensitive cardiopulmonary baroreflex sensitivity (BRS) that leads to exaggerated increases in sympathetic nervous system (SNS) activation during HD.MethodsWe studied ESRD patients on maintenance HD with ID-HTN (n = 10) and without ID-HTN (controls, n = 12) on an interdialytic day, 24 to 30 hours after their last HD session. We measured continuous muscle sympathetic nerve activity (MSNA), beat-to-beat arterial BP, and electrocardiography (ECG) at baseline, and during graded lower body negative pressure (LBNP). Low-dose LBNP isolates cardiopulmonary BRS, whereas higher doses allow assessment of physiologic responses to orthostatic stress.ResultsThe ID-HTN patients had significantly higher pre- and post-HD BP, and greater interdialytic fluid weight gain compared to controls. There was a significantly greater increase in MSNA burst incidence (P = 0.044) during graded LBNP in the ID-HTN group, suggesting heightened cardiopulmonary BRS. The ID-HTN group also had a trend toward increased diastolic BP response during LBNP, and had significantly greater increases in BP during the cold pressor test.ConclusionPatients with ID-HTN have augmented cardiopulmonary BRS that may contribute to increased SNS activation and BP response during HD

An investigation of the bioaccumulation of chromium and uranium metals by Cynodon dactylon: A case study of abandoned New Union Gold Mine Tailings, Limpopo, South Africa

Mine waste, including tailings is generally outlined as one of the largest environmental concern which faces defunct mines in South Africa and New Union Gold Mine is no exception. These tailing contain heavy metal such as chromium (Cr) and uranium (U) which poses enormous threat to the environment even at small quantity. The study focuses mainly on bioaccumulation of Cr and U in soil by Cynodon dactylon, an indigenous grass. The grass and soil sample were collected at New Union Gold Mine and Ka-Madonsi Village at Malamulele, Limpopo Province, South Africa. The concentration of Cr and U were determined with a Thermofischer ICP MS. The research findings indicate that the range in the levels of Cr and U at mine tailings dam A were 152.60 to 196.12 mg/kg and 0.51 to 0.92 μg/gm, respectively. The ranges in the levels of Cr and U at mine tailings dam B were 151.34 to 229.67 mg/kg and 0.85 to 1.06 μg/g, respectively. The levels of Cr and U at the control site were 81.31 mg/kg and 0.73 μg/g. The pH of mine tailing dam A was 3.23 to 3.34 and for tailing dam B were, 3.25 to 3.29 making both tailing acidic while for the control site, it was slightly alkaline at 7.56. The bioconcentration and translation factors of C. dactylon were variable but were dependent on pH conditions. Thus, C. dactylon was able to bioaccumulate toxic metals Cr and U from the mine tailings making them potential phytoremediation agent for the rehabilitation of exposed mine tailings. This is important in covering the mine tailings since any exposed part of mine tailings is liable to water and wind erosion. Thus, Cr and U may be exported to external environment such as aquatic ecosystem and neighboring rural communities with negative impacts.Key words: Phytoremediation, chromium, uranium, indigenous grass, dysfunctional mine tailings

Typologie des exploitations agropastorales du terroir de la NEMA (Sénégal, West Africa)

Dans le terroir de la Néma, pour améliorer les rendements dans un contexte de baisse drastique des superficies cultivables et de la fertilité des sols, les agro-pasteurs ont recours à une gestion intégrée des productions agricoles et animales. Ainsi, suivant leur structure, les exploitations agricoles présentent des formes d’organisation diverses. Pour appréhender cette diversité, deux approches ont été utilisées: l’approche socio-économique (enquête) pour définir les caractéristiques des exploitations et l’approche agronomique visant à évaluer les ressources agricoles. Le traitement des données a permis de distinguer suivant la production et l’utilisation des résidus de récolte, deux groupes d’exploitations : celles qui produisent et utilisent, outre les autres résidus, les résidus de sorgho (A) et celles qui ne produisent et n’utilisent pas ces derniers (B); et suivant la taille, trois groupes d’exploitations: celles de grande taille (B1), de taille moyenne (A et B2) et de petite taille (B3). Si la production et l’épandage du fumier sont généralisés dans les groupes d’exploitations A, B1 et B2, ils sont peu développés dans les petites exploitations (B3). Et ce, du fait de l’absence ou de l’insuffisance du cheptel et de l’outillage agricole dans ces dernières, mais aussi de la faiblesse de la main d’oeuvre. La main d’oeuvre suivant les groupes d’exploitations est évaluée à 3,4 actifs agricoles dans le groupe B3 contre 6,4 ; 7,8 et 17 actifs agricoles respectivement pour les groupes d’exploitations B2, A et B1.Mots clés: Résidus de récolte, gestion intégrée, fertilité, fumier, unités agricole

Effects of Lipid Extraction on δ13C and δ15N Values and Use of Lipid-Correction Models Across Tissues, Taxa and Trophic Groups

1. Lipid-rich animal tissues have low δ13C values, which can lead to inaccurate ecological inferences. Chemical lipid extraction (LE) or correction models account for this depletion, but the need for LE or correction is tissue- and species-specific. Also, LE can alter δ15N values, increasing labour and costs because bulk samples must be analysed for δ15N values separately. 2. We studied the effects of LE on δ13C and δ15N values in liver, muscle and skin of common bottlenose dolphins Tursiops truncatus and West Indian manatees Trichechus manatus, two ecologically important species that occupy different trophic levels. We fit lipid-correction models to each species. We also performed a meta-analysis to more broadly determine the effects of LE across taxa, tissues and trophic groups (carnivores, omnivores and herbivores) and to fit lipid-correction models to different taxonomic and trophic groups. 3. Lipid extraction increased the δ13C values in dolphin tissues but had little effect on manatee tissues and no effect on the δ15N values in either species. A mass balance lipid-correction model best fit the data from all dolphin tissues, and a linear model best fit data for manatee liver while null models best fit data from manatee muscle and skin. Across 128 terrestrial and aquatic species, the effects of LE varied among tissues and were lower for herbivores compared to carnivores. The best-fitting lipid-correction models varied among tissue, taxa and trophic groups. Finally, the δ15N values from muscle and liver were affected by LE. 4. Our results strengthen the growing body of evidence that the need for LE is tissue- and species-specific, without a reliable C:N ratio predictive threshold. The prediction errors of lipid-correction models generally decreased with taxonomic and trophic specificity. The smaller effects of LE in herbivores may be due to differences in diet composition or the physiology of lipid synthesis in members of this trophic group. These results suggest that researchers should use the most species-, tissue- and trophic group-specific information on LE available and, if not available, perform LE on a subset of samples prior to analysis to determine effects

A Deep Learning Model to Predict Traumatic Brain Injury Severity and Outcome from MR Images

For Many Neurological Disorders, Including Traumatic Brain Injury (TBI), Neuroimaging Information Plays a Crucial Role Determining Diagnosis and Prognosis. TBI is a Heterogeneous Disorder that Can Result in Lasting Physical, Emotional and Cognitive Impairments. Magnetic Resonance Imaging (MRI) is a Non-Invasive Technique that Uses Radio Waves to Reveal Fine Details of Brain Anatomy and Pathology. Although MRIs Are Interpreted by Radiologists, Advances Are Being Made in the Use of Deep Learning for MRI Interpretation. This Work Evaluates a Deep Learning Model based on a Residual Learning Convolutional Neural Network that Predicts TBI Severity from MR Images. the Model Achieved a High Sensitivity and Specificity on the Test Sample of Subjects with Varying Levels of TBI Severity. Six Outcome Measures Were Available on TBI Subjects at 6 and 12 Months. Group Comparisons of Outcomes between Subjects Correctly Classified by the Model with Subjects Misclassified Suggested that the Neural Network May Be Able to Identify Latent Predictive Information from the MR Images Not Incorporated in the Ground Truth Labels. the Residual Learning Model Shows Promise in the Classification of MR Images from Subjects with TBI

Polymers in Curved Boxes

We apply results derived in other contexts for the spectrum of the Laplace operator in curved geometries to the study of an ideal polymer chain confined to a spherical annulus in arbitrary space dimension D and conclude that the free energy compared to its value for an uncurved box of the same thickness and volume, is lower when $D < 3$, stays the same when $D = 3$, and is higher when \mbox{$D > 3$}. Thus confining an ideal polymer chain to a cylindrical shell, lowers the effective bending elasticity of the walls, and might induce spontaneous symmetry breaking, i.e. bending. (Actually, the above mentioned results show that {\em {any}} shell in $D = 3$ induces this effect, except for a spherical shell). We compute the contribution of this effect to the bending rigidities in the Helfrich free energy expression.Comment: 20 pages RevTeX, epsf; 4 figures; submitted to Macromoledule

A Predictive Model for User Motivation and Utility Implications of Privacy-Protection Mechanisms in Location Check-Ins

Location check-ins contain both geographical and semantic information about the visited venues. Semantic information is usually represented by means of tags (e.g., “restaurant”). Such data can reveal some personal information about users beyond what they actually expect to disclose, hence their privacy is threatened. To mitigate such threats, several privacy protection techniques based on location generalization have been proposed. Although the privacy implications of such techniques have been extensively studied, the utility implications are mostly unknown. In this paper, we propose a predictive model for quantifying the effect of a privacy-preserving technique (i.e., generalization) on the perceived utility of check-ins. We first study the users’ motivations behind their location check-ins, based on a study targeted at Foursquare users (N = 77). We propose a machine-learning method for determining the motivation behind each check-in, and we design a motivation-based predictive model for the utility implications of generalization. Based on the survey data, our results show that the model accurately predicts the fine-grained motivation behind a check-in in 43% of the cases and in 63% of the cases for the coarse-grained motivation. It also predicts, with a mean error of 0.52 (on a scale from 1 to 5), the loss of utility caused by semantic and geographical generalization. This model makes it possible to design of utility-aware, privacy-enhancing mechanisms in location-based online social networks. It also enables service providers to implement location-sharing mechanisms that preserve both the utility and privacy for their users

ADIÇÃO DE APARAS DE PAPEL RECICLÁVEL NA FABRICAÇÃO DE CHAPAS DE MADEIRA AGLOMERADA

Neste trabalho, foram analisadas as propriedades físico-mecânicas de chapas aglomeradas produzidas com dois tipos de papel reciclável (papel jornal e offset) e partículas de madeira de Pinus elliottii Engelm. As aparas de papel foram usadas no colchão em dois diferentes formatos (tiras ou moídas) e em diferentes proporções: 0, 20, 40, 60 e 100% do peso seco das partículas. Utilizoaram-se 10% de adesivo à base de tanino-formaldeído na proporção 100:10. O experimento foi estabelecido segundo modelo fatorial, com três repetições. Os testes físico-mecânicos das chapas foram realizados segundo a norma ASTM D1037 (1995). Chapas aglomeradas produzidas tanto pela inclusão de papel jornal quanto offset no formato de tiras apresentaram tendência ao estouro durante a abertura dos pratos da prensa, causado pelo alto teor de umidade do colchão. A inclusão de aparas de papel prejudicaram a maioria das propriedades analisadas, fazendo com que não atendessem aos valores estabelecidos pelas normas DIN 68761 (1)-1961, (3)-1971 e ANSI A 208.1 (1987). A absorção d’água após 24 horas de imersão, a ligação interna e a resistência ao arrancamento de parafusos foram as propriedades mais prejudicadas. De modo geral, o uso de papel jornal se mostrou mais promissor do que o papel offset

Lung Cancer: A Classic Example of Tumor Escape and Progression While Providing Opportunities for Immunological Intervention

Lung cancers remain one of the most common and deadly cancers in the world today (12.5% of newly diagnosed cancers) despite current advances in chemo- and radiation therapies. Often, by the time these tumors are diagnosed, they have already metastasized. These tumors demonstrate the classic hallmarks of cancer in that they have advanced defensive strategies allowing them to escape various standard oncological treatments. Immunotherapy is making inroads towards effectively treating other fatal cancers, such as melanoma, glioblastoma multiforme, and castrate-resistant prostate cancers. This paper will cover the escape mechanisms of bronchogenic lung cancer that must be overcome before they can be successfully treated. We also review the history of immunotherapy directed towards lung cancers