Effects of prior repeated-sprints with different recovery duration on oxygen uptake kinetics during subsequent heavy-exercise.

Introduction: Prior repeated-sprints (6) has become an interesting method to resolve the debate surrounding the principal factors that limits the oxygen uptake (V'O2) kinetics at the onset of exercise [i.e., muscle O2 delivery (5) or metabolic inertia (3)]. The aim of this study was to compare the effects of two repeated-sprints sets of 6x6s separated by different recovery duration between the sprints on V'O2 and muscular de-oxygenation [HHb] kinetics during a subsequent heavy-intensity exercise. Methods: 10 male subjects performed a 6-min constant-load cycling test (T50) at intensity corresponding to half of the difference between V'O2max and the ventilatory threshold. Then, they performed two repeated-sprints sets of 6x6s all-out separated by different recovery duration between the sprints (S1:30s and S2:3min) followed, after 7-min-recovery, by the T50 (S1T50 and S2T50, respectively). V'O2, [HHb] of the vastus lateralis (VL) and surface electromyography activity [i.e., root-mean-square (RMS) and the median frequency of the power density spectrum (MDF)] from VL and vastus medialis (VM) were recorded throughout T50. Models using a bi-exponential function for the overall T50 and a mono-exponential for the first 90s of T50 were used to define V'O2 and [HHb] kinetics respectively. Results: V'O2 mean value was higher in S1 (2.9��0.3l.min-1) than in S2 (1.2��0.3l.min-1); (p<0.001). The peripheral blood flow was increased after sprints as attested by a higher basal heart rate (HRbaseline) (S1T50: +22%; S2T50: +17%; p&#8804;0.008). Time delay [HHb] was shorter for S1T50 and S2T50 than for T50 (-22% for both; p&#8804;0.007) whereas the mean response time of V'O2 was accelerated only after S1 (S1T50: 32.3��2.5s; S2T50: 34.4��2.6s; T50: 35.7��5.4s; p=0.031). There were no significant differences in RMS between the three conditions (p>0.05). MDF of VM was higher during the first 3-min in S1T50 than in T50 (+6%; p&#8804;0.05). Conclusion: The study show that V'O2 kinetics was speeded by prior repeated-sprints with a short (30s) but not a long (3min) inter-sprints-recovery even though the [HHb] kinetics was accelerated and the peripheral blood flow was enhanced after both sprints. S1, inducing a greater PCr depletion (1) and change in the pattern of the fibres recruitment (increase in MDF) compared with S2, may decrease metabolic inertia (2), stimulate the oxidative phosphorylation activation (4) and accelerate V'O2 kinetics at the beginning of the subsequent high-intensity exercise.

A New Approach for the Carbon Monoxide (CO) Exposure Diagnosis: Measurement of Total CO in Human Blood Versus Carboxyhemoglobin (HbCO).

The aim of the study is to present the application of a headspace-gas chromatography-mass spectrometry (HS-GC-MS) method for the determination of the carbon monoxide (CO) blood concentration and to compare it with carboxyhemoglobin (HbCO) saturation. In postmortem cases, the HbCO measured by spectrophotometry frequently leads to inaccurate results due to inadequate samples or analyses. The true role of CO intoxication in the death of a person could be misclassified. The estimation of HbCO from HS-GC-MS CO measurements provides helpful information by determining the total CO levels (CO linked to hemoglobin (HbCO) and CO dissociated from hemoglobin). The CO concentrations were converted in HbCO saturation levels to define cutoff blood CO values. CO limits were defined as less than 1��&#956;mol/mL for living persons, less than 1.5��&#956;mol/mL for dead persons without CO exposure, and greater than 3��&#956;mol/mL for dead persons with clear CO poisoning.

Accuracy profile validation of a new analytical method for propane measurement using headspace-gas chromatography-mass spectrometry

Propane can be responsible for several types of lethal intoxication and explosions. Quantifying it would be very helpful to determine in some cases the cause of death. Some gas chromatography-mass spectrometry (GC-MS) methods of propane measurements do already exist. The main drawback of these GC-MS methods described in the literature is the absence of a specific propane internal standard necessary for accurate quantitative analysis. The main outcome of the following study was to provide an innovative Headspace-GC-MS method (HS-GC-MS) applicable to the routine determination of propane concentration in forensic toxicology laboratories. To date, no stable isotope of propane is commercially available. The development of an in situ generation of standards is thus presented. An internal-labeled standard gas (C3DH7) is generated in situ by the stoichiometric formation of propane by the reaction of deuterated water (D2O) with Grignard reagent propylmagnesium chloride (C3H7MgCl). The method aims to use this internal standard to quantify propane concentrations and, therefore, to obtain precise measurements. Consequently, a complete validation with an accuracy profile according to two different guidelines, the French Society of Pharmaceutical Sciences and Techniques (SFSTP) and the Gesellschaft f��r toxikologische und Forensische Chemie (GTFCh), is presented.

An evaluation of the inorganic and organic geochemistry of the San Vicente Mississippi Valley-type zinc-lead district, central Peru: Implications for ore fluid composition, mixing processes, and sulfate reduction

Mississippi Tialley-type zinc-lead deposits and ore occurrences in the San Vicente belt are hosted in dolostones of the eastern Upper Triassic to Lower Jurassic Pucara basin, central Peru. Combined inorganic and organic geochemical data from 22 sites, including the main San Vicente deposit, minor ore occurrences, and barren localities, provide better understanding of fluid pathways and composition, ore precipitation mechanisms, Eh-pH changes during mineralization, and relationships between organic matter and ore formation. Ore-stage dark replacement dolomite and white sparry dolomite are Fe and rare earth element (REE) depleted, and Mn enriched, compared to the host dolomite. In the main deposit, they display significant negative Ce and probably Eu anomalies. Mixing of an incoming hot, slightly oxidizing, acidic brine (H2CO3 being the dominant dissolved carbon species), probably poor in REE and Fe, with local intraformational, alkaline, reducing waters explains the overall carbon and oxygen isotope variation and the distributions of REE and other trace elements in the different hydrothermal carbonate generations. The incoming ore fluid flowed through major aquifers, probably basal basin detrital units, with limited interaction with the carbonate host rocks. The hydrothermal carbonates show a strong regional chemical homogeneity, indicating access of the ore fluids by interconnected channelways near the ore occurrences. Negative Ce anomalies in the main deposit, that are absent at the district scale, indicate local ore-fluid chemical differences. Oxidation of both migrated and indigenous hydrocarbons by the incoming fluid provided the local reducing conditions necessary for sulfate reduction to H2S, pyrobitumen precipitation, and reduction of Eu3+ to Eu2+. Fe-Mn covariations, combined with the REE contents of the hydrothermal carbonates, are consistent with the mineralizing system shifting from reducing/rock-dominated to oxidizing/fluid-dominated conditions following ore deposition. Sulfate and sulfide sulfur isotopes support sulfide origin from evaporite-derived sulfate by thermochemical organic reduction; further evidence includes the presence of C-13-depleted calcite cements (similar to-12 parts per thousand delta(13)C) as sulfate pseudomorphs, elemental sulfur, altered organic matter in the host dolomite, and isotopically heavier, late, solid bitumen. Significant alteration of the indigenous and extrinsic hydrocarbons, with absent bacterial membrane biomarkers (hopanes) is observed. The light delta(34)S of sulfides from small mines and occurrences compared to the main deposit reflect a local contribution of isotopically light sulfur, evidence of local differences in the ore-fluid chemistry.

Symmetric periodic orbits near a heteroclinic loop in R3 formed by two singular points, a semistable periodic orbit and their invariant manifolds

In this paper we consider C1 vector fields X in R3 having a ���generalized heteroclinic loop��� L which is topologically homeomorphic to the union of a 2���dimensional sphere S2 and a diameter connecting the north with the south pole. The north pole is an attractor on S2 and a repeller on . The equator of the sphere is a periodic orbit unstable in the north hemisphere and stable in the south one. The full space is topologically homeomorphic to the closed ball having as boundary the sphere S2. We also assume that the flow of X is invariant under a topological straight line symmetry on the equator plane of the ball. For each n ��� N, by means of a convenient Poincar��e map, we prove the existence of infinitely many symmetric periodic orbits of X near L that gives n turns around L in a period. We also exhibit a class of polynomial vector fields of degree 4 in R3 satisfying this dynamics.

Blunting the response to endotoxin in healthy sujects : effects of various dose of intravenous fish oil

Enjeux et contexte La recherche de cette derni��re d��cennie sur les acides gras n-3 PUFA contenus dans l'huile de poisson a montr�� que ceux-ci, et particuli��rement l'&#917;&#929;&#913; et le DHA, avaient des propri��t��s anti��inflammatoires et anti arythmiques puissantes, potentiellement utiles chez les septiques et �� cardiaques ��. Les m��canismes sous-jacents sont nombreux, incluant l'incorporation des acides gras dans les membranes de phopholipides, la r��duction de la production de m��diateurs pro-inflammatoires (prostaglandines, leukotrienes, thromboxane), l'augmentation de la production de r��solvines et protectines d��riv��es du DHA, et la r��gulation de voies de signalisation cellulaire. Cependant, les doses de n-3 PUFA utilis��es dans les ��tudes cliniques et chez le sujet sain avant le travail de Yann-Karim Pittet ��taient nettement sup��rieures aux doses nutritionnelles de l'ordre de 5-8 g/j par voie orale ou 1 g/kg par voie intraveineuse. De plus, la voie ent��rale avait la r��putation de n��cessiter plusieurs jours �� semaines de traitement avant d'aboutir �� une incorporation d'acides gras membranaire suffisante pour avoir un impact clinique; quant au temps minimal requis pour obtenir cet effet par voie IV, il ��tait inconnu. Depuis, le d��veloppement d'��mulsions lipidiques intraveineuses destin��es �� la nutrition parent��rale a permis d'imaginer l'administration de pr��traitements IV rapides. Pour les ��tudier, notre laboratoire a d��velopp�� un mod��le d'endotoxine (LPS d'E.Coli) qui mime les r��ponses physiologique, endocrinienne et biologique du sepsis chez le sujet sain, utilisant des doses de 2 ng/kg IV. Les r��ponses sont totalement r��versibles en 8 heures. Dans le but de r��duire �� la fois la dose de lipides et le temps de perfusion, ce travail a ��tudi�� l'influence de 3 doses d��gressives de n-3 PUFA sur les r��ponses �� l'endotoxine, et sur l'incorporation membranaire de ces acides gras. M��thodes Etude prospective chez 3 groupes cons��cutifs de sujets sains soumis �� un challenge d'endotoxine. Intervention : perfusions d'huile de poisson (0.5 et 0.2 g/kg de n-3 PUFA, Omegaven�� 10%) ou placebo, administr��es en 3 heures ou en 1 heure, soit le jour avant ou le jour-m��me du test d'endotoxine. Mesures : variables physiologiques (T��, fc, tension art��rielle, calorim��trie indirecte) Laboratoire - prises de sang �� T0, 60, 120 et 360 min apr��s l'injection de LPS: TNF-&#945;, hs-CRP, hormones de stress, composition en acides gras des membranes plaquettaires. Statistiques Les r��sultats ont ��t�� rapport��s en moyennes et ��carts types. Des aires sous la courbe (AUC) ont ��t�� calcul��es avec la m��thode des parall��l��pip��des pour toutes les variables d��termin��es de mani��re r��p��t��e. L'effet du temps a ��t�� explor�� par des two-way ANOVA pour mesures r��p��t��es. Les comparaisons post-hoc ont ��t�� r��alis��es avec des tests de Dunnett's ou de Scheffe. Les modifications de composition membranaires ainsi que les AUC ont ��t�� analys��es par des tests non-param��triques (Kruskal-Wallis). R��sultats Apr��s LPS, la temp��rature, les concentrations d'ACTH et TNF-&#945; ont augment�� dans les 3 groupes. Ces r��ponse ont ��t�� significativement att��nu��es (p<0.0001) par l'huile de poisson compar�� �� ce que nous avions observ�� dans le groupe contr��le de Pluess et al (ICM 2007). Les concentrations les plus faibles d'ACTH, de TNF-&#945;, et les AUC les plus basses des temp��ratures, ont ��t�� observ��es apr��s une dose unique de 0.2 g/kg de n-3 PUFA administr��e 1 heure avant le LPS. Par contre, l'incorporation membranaire d'EPA est dose-d��pendante. Conclusions Sachant que la r��ponse �� l'endotoxine est reproductible, cette ��tude montre que 3 doses diff��rentes d'huile de poisson att��nuent de mani��re diff��rente cette r��ponse. La perfusion de 0.2 g/kg administr��e juste avant l'endotoxine s'est av��r��e la plus efficace �� att��nuer la r��ponse f��brile, les cytokines et les hormones de stress, sugg��rant une capture de l'endotoxine par l'��mulsion lipidique qui se surajoute aux effets syst��miques et membranaires.

Association between Inflammatory and Obesity Markers in a Swiss Population-Based Sample (CoLaus Study).

Objective: To assess the associations between obesity markers (BMI, waist circumference and %body fat) and inflammatory markers (interleukin-1&#946; (IL-1&#946;); interleukin-6 (IL-6); tumor necrosis factor-&#945; (TNF-&#945;) and high-sensitivity C-reactive protein (hs-CRP)). Methods: Population sample of 2,884 men and 3,201 women aged 35-75 years. Associations were assessed using ridge regression adjusting for age, leisure-time physical activity, and smoking. Results: No differences were found in IL-1&#946; levels between participants with increased obesity markers and healthy counterparts; multivariate regression showed %body fat to be negatively associated with IL-1&#946;. Participants with high %body fat or abdominal obesity had higher IL-6 levels, but no independent association between IL-6 levels and obesity markers was found on multivariate regression. Participants with abdominal obesity had higher TNF-&#945; levels, and positive associations were found between TNF-&#945; levels and waist circumference in men and between TNF-&#945; levels and BMI in women. Obese participants had higher hs-CRP levels, and these differences persisted after multivariate adjustment; similarly, positive associations were found between hs-CRP levels and all obesity markers studied. Conclusion: Obesity markers are differentially associated with cytokine levels. %Body fat is negatively associated with IL-1&#946;; BMI (in women) and waist circumference (in men) are associated with TNF-&#945;; all obesity markers are positively associated with hs-CRP. Copyright �� 2012 S. Karger GmbH, Freiburg.

An improved approach for predicting the distribution of rare and endangered species from occurrence and pseudo-absence data

1. Few examples of habitat-modelling studies of rare and endangered species exist in the literature, although from a conservation perspective predicting their distribution would prove particularly useful. Paucity of data and lack of valid absences are the probable reasons for this shortcoming. Analytic solutions to accommodate the lack of absence include the ecological niche factor analysis (ENFA) and the use of generalized linear models (GLM) with simulated pseudo-absences. 2. In this study we tested a new approach to generating pseudo-absences, based on a preliminary ENFA habitat suitability (HS) map, for the endangered species Eryngium alpinum. This method of generating pseudo-absences was compared with two others: (i) use of a GLM with pseudo-absences generated totally at random, and (ii) use of an ENFA only. 3. The influence of two different spatial resolutions (i.e. grain) was also assessed for tackling the dilemma of quality (grain) vs. quantity (number of occurrences). Each combination of the three above-mentioned methods with the two grains generated a distinct HS map. 4. Four evaluation measures were used for comparing these HS maps: total deviance explained, best kappa, Gini coefficient and minimal predicted area (MPA). The last is a new evaluation criterion proposed in this study. 5. Results showed that (i) GLM models using ENFA-weighted pseudo-absence provide better results, except for the MPA value, and that (ii) quality (spatial resolution and locational accuracy) of the data appears to be more important than quantity (number of occurrences). Furthermore, the proposed MPA value is suggested as a useful measure of model evaluation when used to complement classical statistical measures. 6. Synthesis and applications. We suggest that the use of ENFA-weighted pseudo-absence is a possible way to enhance the quality of GLM-based potential distribution maps and that data quality (i.e. spatial resolution) prevails over quantity (i.e. number of data). Increased accuracy of potential distribution maps could help to define better suitable areas for species protection and reintroduction.

Modelagem da emiss��o de folhas em arroz cultivado e em arroz-vermelho

O objetivo deste trabalho foi simular o aparecimento de folhas em gen��tipos de arroz cultivados e em bi��tipos de arroz-vermelho por meio da adapta����o do modelo de Wang e Engel, modificado por Streck et al. Dois experimentos foram conduzidos em Santa Maria, RS, em 2004/2005 e 2005/2006. Foram utilizadas as cultivares IRGA 417 e EEA 406, um h��brido e dois bi��tipos de arroz-vermelho. O modelo de aparecimento de folhas foi ajustado para os gen��tipos usando-se dados de est��gio de Haun (HS), de cinco ��pocas de semeadura, em 2004/2005, e a avalia����o do modelo foi feita com dados de HS medidos em tr��s ��pocas de semeadura, em 2005/2006. Realizou-se tamb��m um experimento num��rico utilizando-se dados de temperatura de 2003/2004 e de 2006/2007, e comparou-se o HS simulado dos gen��tipos cultivados em rela����o aos bi��tipos de arroz-vermelho. O modelo apresentou bom desempenho para simular o HS com raiz do quadrado m��dio do erro geralmente menor do que uma folha. A emiss��o de folhas na haste principal foi maior nos gen��tipos modernos - IRGA 417 e h��brido - do que no gen��tipo tradicional EEA 406. A emiss��o de folhas �� diferente em distintos bi��tipos de arroz-vermelho.

Densidade de estocagem e salinidade da ��gua na larvicultura do pacam��

O objetivo deste trabalho foi avaliar o efeito da densidade de estocagem e da salinidade da ��gua, na larvicultura do pacam�� Lophiosilurus alexandri, alimentado com n��uplios de Artemia sp. Foram utilizadas tr��s densidades de estocagem: 20, 40 e 60 larvas L-1 (D20, D40 e D60, respectivamente). Para cada densidade testaram-se tr��s ��ndices de salinidade da ��gua: ��gua doce (S0), 2�� (S2) e 4�� (S4), em delineamento experimental inteiramente ao acaso, em esquema fatorial 3x3, com tr��s repeti����es. Foram analisados: crescimento, sobreviv��ncia, mortalidade, canibalismo, produtividade e n��veis de am��nia n��o ionizada. As concentra����es de am��nia n��o ionizada foram maiores nas densidades D40 e D60. Aos dez dias de alimenta����o, o peso foi afetado negativamente em D40 e D60 associado �� maior salinidade da ��gua (S4). A maior sobreviv��ncia foi obtida no tratamento D20S2, enquanto os menores valores foram registrados em rela����o �� salinidade S4, independentemente da densidade testada. Foram verificadas baixas taxas de mortalidade e aus��ncia de canibalismo. A produ����o de juvenis tamb��m foi influenciada pelos fatores avaliados. Larvas de L. alexandri podem ser criadas, durante os dez primeiros dias de alimenta����o ex��gena, em ��gua doce ou a 2�� com maior produ����o de juvenis na densidade D60.

Distribui����o espacial da variabilidade gen��tica intrapopulacional de Dipteryx alata

O objetivo deste trabalho foi avaliar o padr��o espacial da variabilidade gen��tica entre plantas, dentro de tr��s popula����es naturais de barueiro (Dipteryx alata Vogel), pela genotipagem por RAPD e t��cnicas de autocorrela����o espacial. Os cinco iniciadores RAPD permitiram a codifica����o de 45 locos, utilizados nas an��lises de diversidade, estrutura e distribui����o espacial da variabilidade gen��tica entre popula����es. As popula����es apresentaram diversidade gen��tica (Hs) com valor m��dio 0,314. Verificou-se que 12% da varia����o total se encontra entre as popula����es, o que indica que estas mant��m um consider��vel n��vel de variabilidade gen��tica. Foi observada tend��ncia de autocorrela����o espacial positiva nas primeiras classes de dist��ncias, nas tr��s popula����es, o que indica a forma����o de grupos de vizinhan��a com estrutura����o familiar, dentro das popula����es de barueiro. Entretanto, o tamanho desses grupos de vizinhan��a varia entre as popula����es; isso mostra que outros processos ecol��gicos influenciaram a distribui����o espacial da variabilidade gen��tica. As popula����es naturais de barueiro apresentam consider��veis n��veis de diversidade gen��tica, com base nos 45 locos RAPD avaliados.

Effects of particulate matter on inflammatory markers in the general adult population.

BACKGROUND: Particulate air pollution is associated with increased risk of cardiovascular disease and stroke. Although the precise mechanisms underlying this association are still unclear, the induction of systemic inflammation following particle inhalation represents a plausible mechanistic pathway.��METHODS: We used baseline data from the CoLaus Study including 6183 adult participants residing in Lausanne, Switzerland. We analyzed the association of short-term exposure to PM10 (on the day of examination visit) with continuous circulating serum levels of high-sensitive C-reactive protein (hs-CRP), interleukin 1-beta (IL-1&#946;), interleukin 6 (IL-6), and tumor-necrosis-factor alpha (TNF-&#945;) by robust linear regressions, controlling for potential confounding factors and assessing effect modification.��RESULTS: In adjusted analyses, for every 10&#8201;&#956;g/m3 elevation in PM10, IL-1�� increased by 0.034 (95&#8201;% confidence interval, 0.007-0.060) pg/mL, IL-6 by 0.036 (0.015-0.057) pg/mL, and TNF-&#945; by 0.024 (0.013-0.035) pg/mL, whereas no significant association was found with hs-CRP levels.��CONCLUSIONS: Short-term exposure to PM10 was positively associated with higher levels of circulating IL-1��, IL-6 and TNF-&#945; in the adult general population. This positive association suggests a link between air pollution and cardiovascular risk, although further studies are needed to clarify the mechanistic pathway linking PM10 to cardiovascular risk.

Anti-HLA antibody repertoire after IVIg infusion in highly sensitized patients waiting for kidney transplantation.

Polyclonal intravenous immunoglobulin (IVIg) treatment reduces crossmatch positivity and increases rates of transplantation in highly sensitised patients (HS). We quantified the panel reactive antibody (PRA) by microlymphocytotoxicity (MLCC), and we analysed anti-HLA class I and class II IgG specific antibody repertoire by Luminex before and after IVIg infusion alone in HS patients awaiting kidney transplantation. Five patients received three monthly infusions of 1 g/kg of IVIg. Serum samples collected pre and post IVIg treatment were submitted for PRA analysis by MLCC. Anti-class I and anti-class II antibody specificities were then tested by Luminex. We focused on the anti-HLA class I and class II antibodies directed against HLA expressed by a previous graft. We also analysed the anti-HLA antibody repertoire in three patients who had not received IVIg infusion. The PRA level determined by MLCC decreased significantly in one of the five patients, dropping from 40% to 17%. The Luminex assay showed fluctuations of the anti-HLA antibody levels over time, but no significant longterm modifications of the anti-HLA antibody repertoire were observed, even in the patient with a strong and prolonged reduction of the PRA determined by MLCC. Our results show that IVIg at 1 g/kg is not sufficient to reduce PRA and does not modify the repertoire of specific anti-HLA antibody determined by Luminex.

Cross-validation of methods used for analysis of MTBE and other gasoline components in groundwater.

Head space gas chromatography with flame-ionization detection (HS-GC-FID), ancl purge and trap gas chromatography-mass spectrometry (P&T-GC-MS) have been used to determine methyl-tert-butyl ether (MTBE) and benzene, toluene, and the ylenes (BTEX) in groundwater. In the work discussed in this paper measures of quality, e.g. recovery (94-111%), precision (4.6 - 12.2%), limits of detection (0.3 - 5.7 I~g L 1 for HS and 0.001 I~g L 1 for PT), and robust-ness, for both methods were compared. In addition, for purposes of comparison, groundwater samples from areas suffering from odor problems because of fuel spillage and tank leakage were analyzed by use of both techniques. For high concentration levels there was good correlation between results from both methods.