Geometry, petrology and growth of a shallow crustal laccolith : the Torres del Paine Mafic Complex (Patagonia)

1. ABSTRACTS - RÉSUMÉSSCIENTIFIC ABSTRACT - ENGLISH VERSIONGeometry, petrology and growth of a shallow crustal laccolith: the Torres del Paine Mafi c Complex (Patagonia)The Torres del Paine intrusive complex (TPIC) is a composite mafic-granitic intrusion, ~70km2, belonging to a chain of isolated Miocene plutons in southern Patagonia. Their position is intermediate between the Mesozoic-Cenozoic calc-alkaline subduction related Patagonian batholith in the West and the late Cenozoic alkaline basaltic back-arc related plateau lavas in the East. The Torres del Paine complex formed during an important reconfiguration of the Patagonian geodynamic setting, with a migration of magmatism from the arc to the back-arc, possibly related to the Chile ridge subductionThe complex intruded the flysch of the Cretaceous Cerro Toro and Punta Barrosa Formations during the Miocene, creating a well-defined narrow contact aureole of 200-400 m width.In its eastern part, the Torres del Paine intrusive complex is a laccolith, composed of a succession of hornblende-gabbro to diorite sills at its base, with a total thickness of ~250m, showing brittle contacts with the overlying granitic sills, that form spectacular cliffs of more than 1000m. This laccolith is connected, in the western part, to its feeding system, with vertical alternating sheets of layered gabbronorite and Hbl-gabbro, surrounded and percolated by diorites. ID-TIMS U-Pb on zircons on feeder zone (FZ) gab- bros yield 12.593±0.009Ma and 12.587±0.009Ma, which is identifcal within error to the oldest granite dated so far by Michel et al. (2008). In contrast, the laccolith mafic complex is younger than than the youngest granite (12.50±0.02Ma), and has been emplaced from 12.472±0.009Ma to 12.431 ±0.006Ma, by under-accretion beneath the youngest granite at the interface with previously emplaced mafic sills.The gabbronorite crystallization sequence in the feeder zone is dominated by olivine, plagioclase, clinopyroxene and orthopyroxene, while amphibole forms late interstitial crystals. The crystallization sequence is identical in Hornblende-gabbro from the feeder zone, with higher modal hornblende. Gabbronorite and Hornblende-gabbro both display distinct Eu and Sr positive anomalies. In the laccolith, a lower Hornblende-gabbro crystallized in sills and evolved to a high alkali shoshonitic series. The Al203, Ti02, Na20, K20, Ba and Sr composition of these gabbros is highly variable and increases up to ~50wt% Si02. The lower hornblende-gabbro is characterized by kaersutite anhedral cores with inclusions of olivine, clino- and orthopyroxene and rare apatite and An70 plagioclase. Trace element modelling indicates that hornblende and clinopyroxene are in equilibrium with a liquid whose composition is similar to late basaltic trachyandesitic dikes that cut the complex. The matrix in the lower hornblende gabbro is composed of normally zoned oligoclase, Magnesio-hornblende, biotite, ilmenite and rare quartz and potassium feldspar. This assemblage crystallized in-situ from a Ba and Sr-depleted melts. In contrast, the upper Hbl-gabbro is high-K calc-alkaline. Poikilitic pargasite cores have inclusions of euhedral An70 plagioclase inclusions, and contain occasionally clinopyroxene, olivine and orthopyroxene. The matrix composition is identical to the lower hornblende-gabbro and similar to the diorite. Diorite bulk rock compositions show the same mineralogy but different modal proportions relative to hornblende-gabbrosThe Torres del Paine Intrusive Complex isotopic composition is 87Sr/86Sr=0.704, 143Nd/144Nd=0.5127, 206Pb/204Pb=18.70 and 207Pb/204Pb=15.65. Differentiated dioritic and granitic units may be linked to the gabbroic cumulates series, with 20-50% trapped interstitial melt, through fractionation of olivine-bearing gabbronorite or hornblende-gabbro fractionation The relative homogeneity of the isotopic compositions indicate that only small amounts of assimilation occurred. Two-pyroxenes thermometry, clinopyroxene barometry and amphibole-plagioclase thermometry was used to estimate pressure and temperature conditions. The early fractionation of ultramafic cumulates occurs at mid to lower crustal conditions, at temperatures exceeding 900°C. In contrast, the TPIC emplacement conditions have been estimated to ~0.7±0.5kbar and 790±60°C.Based on field and microtextural observations and geochemical modelling, fractionation of basaltic-trachyandesitic liquids at intermediate to lower crustal levels, has led to the formation of the Torres del Paine granites. Repetitive replenishment of basaltic trachy- andesitic liquid in crustal reservoirs led to mixed magmas that will ascend via the feeder zone, and crystallize into a laccolith, in the form of successive dioritic and gabbroic sills. Dynamic fractionation during emplacement concentrated hornblende rich cumulates in the center of individual sills. Variable degrees.of post-emplacement compaction led to the expulsion of felsic liquids that preferentially concentrated at the top of the sills. Incremental sills amalgamation of the entire Torres del Paine Intrusive Complex has lasted for ~160ka.RESUME SCIENTIFIQUE - VERSION FRANÇAISEGéométrie, pétrologie et croissance d'un laccolite peu profond : Le complexe ma- fique du Torres del Paine (Patagonie)Le Complexe Intrusif du Torres del Paine (CITP) est une intrusion bimodale, d'environ 70km2, appartenant à une chaîne de plutons Miocènes isolés, dans le sud de la Patago-nie. Leur position est intermédiaire entre le batholite patagonien calco-alcalin, à l'Ouest, mis en place au Mesozoïque-Cenozoïque dans un contexte de subduction, et les basal-tes andésitiques et trachybasaltes alcalins de plateau, plus jeune, à l'Est, lié à l'ouverture d'un arrière-arc.A son extrémité Est, le CITP est une succession de sills de gabbro à Hbl et de diorite, sur une épaisseur de ~250m, avec des évidences de mélange. Les contacts avec les sills de granite au-dessus, formant des parois de plus de 1000m, sont cassants. Ce laccolite est connecté, dans sa partie Ouest, à une zone d'alimentation, avec des intrusions sub-ver- ticales de gabbronorite litée et de gabbro à Hbl, en alternance. Celles-ci sont traversées et entourées par des diorites. Les zircons des gabbros de la zone d'alimentation, datés par ID-TIMS, ont cristallisés à 12.593±0.009Ma et 12.587±0.009Ma, ce qui correspond au plus vieux granite daté à ce jour par Michel et al. (2008). A l'inverse, les roches manques du laccolite se sont mises en place entre 12.472±0.009Ma et 12.431 ±0.006Ma, par sous-plaquage successifs à l'interface avec le granite le plus jeune daté à ce jour (12.50±0.02Ma).La séquence de cristallisation des gabbronorites est dominée par Ol, Plg, Cpx et Opx, alors que la Hbl est un cristal interstitiel. Elle est identique dans les gabbros à Hbl de la zone d'alimentation, avec ~30%vol de Hbl. Les gabbros de la zone d'alimentation montrent des anomalies positives en Eu et Sr distinctes. Dans le laccolite, le gabbro à Hbl inférieur évolue le long d'une série shoshonitique, riche en éléments incompatibles. Sa concentration en Al203, Ti02, Na20, K20, Ba et Sr est très variable et augmente rapide-ment jusqu'à ~50wt% Si02. Il est caractérisé par la présence de coeurs résorbés de kaer- sutite, entourés de Bt, et contenant des inclusions d'OI, Cpx et Opx, ou alors d'Ap et de rares Plg (An70). Hbl et Cpx ont cristallisés à partir d'un liquide de composition similaire aux dykes trachy-andesite basaltique du CITP. La matrice, cristallisée in-situ à partir d'un liquide pauvre en Ba et Sr, est composée d'oligoclase zoné de façon simple, de Mg-Hbl, Bt, llm ainsi que de rares Qtz et KF. Le gabbro à Hbl supérieur, quant à lui, appartient à une suite chimique calco-alcaline riche en K. Des coeurs poecilitiques de pargasite con-tiennent de nombreuses inclusions de Plg (An70) automorphe, ainsi que des Ol, Cpx et Opx. La composition de la matrice est identique à celle des gabbros à Hbl inférieurs et toutes deux sont similaires à la minéralogie des diorites. Les analyses sur roches totales de diorites montrent la même variabilité que celles de gabbros à Hbl, mais avec une ten-eur en Si02 plus élevée.La composition isotopique des liquides primitifs du CITP a été mesurée à 87Sr/86Sr=0.704, 143Nd/144Nd=0.5127, 206Pb/204Pb=18.70 et 207Pb/204Pb=15.65. Les granites et diorites différenciés peuvent être reliés à des cumulais gabbronoritiques (F=0.74 pour les granites et F=1-0.5 pour les diorites) et gabbroïques à Hbl (fractionnement supplémentaire pour les granites, avec F=0.3). La cristallisation de 20 à 50%vol de liquide interstitiel piégé dans les gabbros du CITP explique leur signature géochimique. Seules de faibles quantités de croûte continentale ont été assimilées. La température et la pression de fractionnement ont été estimées, sur la base des thermobaromètres Opx-Cpx, Hbl-Plg et Cpx, à plus de 900°C et une profondeur correspondant à la croûte inférieure-moyenne. A l'inverse, les conditions de cristallisation de la matrice des gabbros et diorites du laccolite ont été estimées à 790±60°C et ~0.7±0.5kbar.Je propose que les liquides felsiques du CITP se soient formés par cristallisation frac-tionnée en profondeur des assemblages minéralogiques observés dans les gabbros du CITP, à partir d'un liquide trachy-andesite basaltique. La percolation de magma dans les cristaux accumulés permet la remontée du mélange à travers la zone d'alimentation, vers le laccolite, où des sills se mettent en place successivement. L'amalgamation de sills dans le CITP a duré ~160ka.Le CITP s'est formé durant une reconfiguration importante du contexte géodynamique en Patagonie, avec un changement du magmatisme d'arc vers un volcanisme d'arrière- arc. Ce changement est certainement lié à la subduction de la ride du Chili.RESUME GRAND PUBLIC - VERSION FRANÇAISEGéométrie, pétrologie et croissance d'une chambre magmatique peu profonde : Le complexe mafique du Torres del Paine (Patagonie)Le pourtour de l'Océan Pacifique est caractérisé par une zone de convergence de plaques tectoniques, appelée zone de subduction, avec le plongement de croûte océa-nique sous les Andes dans le cas de la Patagonie. De nombreux volcans y sont associés, formant la ceinture de feu. Mais seuls quelques pourcents de tout le magma traversant la croûte terrestre parviennent à la surface et la majeure partie cristallise en profondeur, dans des chambres magmatiques. Quelles est leur forme, croissance, cristallisation et durée de vie ? Le complexe magmatique du Torres del Paine représente l'un des meilleurs endroits au monde pour répondre à ces questions. Il se situe au sud de la Patagonie, formant un massif de 70km2. Des réponses peuvent être trouvées à différentes échelles, variant de la montagne à des minéraux de quelques 1000ème de millimètres.Il est possible de distinguer trois types de roches : des gabbros et des diorites sur une épaisseur de 250m, surmontées par des parois de granite de plus de 1000m. Les contacts entre ces roches sont tous horizontaux. Entre granites et gabbro-diorite, le contact est net, indiquant que le second magma s'est mis en place au contact avec un magma plus ancien, totalement solidifié. Entre gabbros et diorites, les contacts sont diffus, souvent non-linéaires, indiquant à l'inverse la mise en contact de magmas encore partiellement liquides. Dans la partie Ouest de cette chambre magmatique, les contacts entre roches sont verticaux. Il s'agit certainement du lieu de remplissage de la chambre magmatique.Lors du refroidissement d'un magma, différents cristaux vont se former. Leur stabilité et leur composition varient en fonction de la pression, de la température ou de la chimie du magma. La séquence de cristallisation peut être définie sur la base d'observations microscopiques et de la composition chimique des minéraux. Différents gabbros sont ainsi distingués : le gabbro à la base est riche en hornblende, d'une taille de ~5mm, sans inclusion de plagioclase mais avec des cristaux d'olivine, clinopyroxene et orthopyroxene inclus ; le gabbro supérieur est lui-aussi riche en hornblende (~5mm), avec les mêmes inclusions additionnées de plagioclase. Ces cristaux se sont formés à une température supérieure à 900°C et une profondeur correspondant à la croûte moyenne ou inférieure. Les minéraux plus fin, se trouvant hors des cristaux de hornblende des deux gabbros, sont similaires à ceux des diorites : plagioclase, biotite, hornblende, apatite, quartz et feldspath alcalin. Ces minéraux sont caractéristiques des granites. Ils ont cristallisé à ~790°C et ~2km de profondeur.La cristallisation des minéraux et leur extraction du magma par gravité provoque un changement progressif de la composition de ce dernier. Ainsi, après extraction d'olivine et d'orthopyroxene riches en Mg, de clinopyroxene riche en Ca, de plagioclase riche en Ca et Al et d'hornblende riche en Ca, Al et Mg, le liquide final sera appauvri en ces élé-ments. Un lien peut ainsi être proposé entre les diorites dont la composition est proche du liquide de départ, les granites dont la composition est similaire au liquide final, et les gabbros dont la minéralogie correspond aux minéraux extraits.L'utilisation de zircons, un minéral riche en U dont les atomes se transforment en Pb par décomposition radioactive au cours de millions d'années, permet de dater le refroidissement des roches qui les contiennent. Ainsi, il a été observé que les roches de la zone d'alimentation, à l'Ouest du complexe magmatique, ont cristallisés il y a 12.59±0.01 Ma, en même temps que les granites les plus vieux, se trouvant au sommet de la chambre magmatique, datés par Michel et al. (2008). Les deux roches pourraient donc avoir la même origine. A l'inverse, les gabbros et diorites de la chambre magmatique ont cristallisé entre 12.47±0.01Ma et 12.43±0.01Ma, les roches les plus vieilles étant à la base.En comparant la composition des roches du Torres del Paine avec celles d'autres en-tités géologiques de Patagonie, les causes du magmatisme peuvent être recherchées. A l'Ouest, on trouve en effet des intrusions granitiques, plus anciennes, caractéristiques de zones de convergence de plaque tectonique, alors qu'à l'Est, des laves basaltiques plus jeunes sont caractéristiques d'une dynamique d'extension. Sur la base des compositions chimiques des roches de ces différentes entités, l'évolution progressive de l'une à l'autre a pu être démontrée. Elle est certainement due à l'arrivée d'une dorsale océanique (zone d'extension crustale et de création de croûte océanique par la remontée de magma) dans la zone de subduction, le long des Andes.Je propose que, dans un premier temps, des magmas granitiques sont remontés dans la chambre magmatique, laissant d'importants volumes de cristaux dans la croûte pro-fonde. Dans un second épisode, les cristaux formés en profondeur ont été transportés à travers la croûte continentale, suite au mélange avec un nouveau magma injecté. Ces magmas chargés de cristaux ont traversé la zone d'alimentation avant de s'injecter dans la chambre magmatique. Différents puises ont été distingués, injectés dans la chambre magmatique du sommet à la base concernant les granites, puis à la base du granite le plus jeune pour les gabbros et diorites. Le complexe magmatique du Torres del Paine s'est construit sur une période totale de 160'000±20'000 ans.

Analysis of antiviral immunity in primary and chronic infections

Several evidences in humans underscored the contribution of CD4 and CD8 T-cell responses in controlling viral and bacterial infections. However, CD4 and CD8 Τ cells have distinct and specific effector functions leading to a hierarchical importance in responding to different types of pathogens. In this context, the present work aimed to investigate distinct CD8 T-cell features potentially influencing T-cell efficacy against viral infection. To achieve this-objective, CD8 Τ cells derived from HIV-infected patients and healthy donors harbouring virus-specific immune responses or immunized with an HTV vaccine candidate were studied. In particular, we performed a comprehensive cross-sectional and longitudinal analysis to characterize the function, the phenotype and the functional avidity of HIV-specific CD8 Τ cells during acute (PHI) and chronic infection and, in particular, we investigated immunological parameters potentially associated with the functional avidity of HIV-specific CD8 Τ cells. In addition, we studied the expression pattern of co-inhibitory molecules and the influence of CD 160 on the functions of CD8 Τ cells in absence of chronic infections. From these analyses we observed that the functional avidity of HIV-specific CD8 T- cell responses was significantly lower in acute than in chronic infection, but was not different between chronic progressive and non-progressive patients. Functional avidity remained low after several years of antiretroviral therapy in PHI patients, but increased in patients experiencing a virus rebound following treatment interruption in association with a massive renewal of the global CD8 complementarity-determining region 3 of the TCR. The functional avidity was also directly associated to T-cell exhaustion. In individuals with no sign of HIV or Hepatitis A, Β or C virus infection, CD8 Τ cells expressed higher levels of co-inhibitory molecules than CD4 Τ cells and this was dependent on the stage of T-cell differentiation and activation. The expression of CD 160 impaired the proliferation capacity and IL-2 production of CD8 Τ cells and was reduced upon CD8 T-cell activation, entitling CD 160 as unique marker of CD8 T-cell exhaustion. The CD 160 blockade restored the proliferation capacity of virus-specific CD8 Τ cells providing a potential new target for immunotherapy. All together, these results expand our knowledge regarding the interplay between the immune system and the viruses. - De nombreuses études chez l'Homme ont mis en évidence la contribution des réponses cellulaires Τ CD4 et CD8 dans le contrôle des infections virales et bactériennes. En particulier, les lymphocytes Τ ont différentes fonctions effectrices spécifiques qui leur confèrent un rôle clé lors d'infections par différents pathogènes. Ce travail vise à étudier différentes caractéristiques des cellules Τ CD8 affectant l'efficacité des réponses cellulaires contre les virus. Pour atteindre cet objectif nous avons étudié les cellules Τ CD8 provenant de patients infectés par le VIH et de donneurs sains avec des réponses immunitaires naturelles ou vaccinales contre des virus. Nous avons effectué plusieurs analyses transversales et longitudinales des fonctions, du phénotype et de l'avidité fonctionnelle des lymphocytes Τ CD8 spécifiques au VIH au cours d'infections aiguës et chroniques; en particulier, nous avons étudié les paramètres immunologiques qui pourraient être associés à l'avidité fonctionnelle. De plus, nous avons investigué le profil d'expression des principales molécules co-inhibitrices et en particulier le rôle du CD 160 dans les fonctions des lymphocytes Τ CD8. Sur la base de ces analyses, nous avons constaté que l'avidité fonctionnelle des cellules Τ CD8 spécifiques au VIH était significativement plus faible lors infections aiguës que lors d'infections chroniques, mais n'était, par contre, pas différente entre les patients avec des infections chroniques progressives et non progressives. L'avidité fonctionnelle reste faible après plusieurs années de traitement antirétroviral, mais augmente chez les patients subissant un rebond viral, et donc exposés à des hautes virémies, suite à l'interruption du traitement. Cette augmentation d'avidité des lymphocytes Τ CD8, liée à un épuisement fonctionnel accru, était quantitativement directement associée à un renouvellement massif du TCR. Indépendamment de l'infection par le VIH, les cellules Τ CD8 expriment des niveaux plus élevés de molécules co-inhibitrices (PD-1, 2B4 et CD 160) par rapport aux cellules Τ CD4 et ceci dépend de leur stade de différenciation et d'activation. En particulier, CD 160 semble être un marqueur clé d'épuisement cellulaire des cellules Τ CD8, et donc une nouvelle cible potentielle pour l'immunothérapie, car a) son expression réduit la capacité proliférative et la production d'IL-2 b) CD 160 diminue suite à 1'activation et c) le blocage de CD 160 redonne la capacité proliférative aux cellules Τ CD8 spécifiques aux virus. - Le système immunitaire est un ensemble de cellules, tissus et organes indispensables pour limiter l'entrée des pathogènes à travers la peau et les muqueuses. Parmi les différentes cellules composant le système immunitaire, les cellules Τ CD4 et CD8 sont fondamentales pour le contrôle des infections virales et bactériennes. Les moyens pour combattre les différents pathogènes peuvent être cependant très variables. Les cellules Τ CD8, qui sont indispensables pour la lutte contre les virus, peuvent avoir différents niveaux de sensibilité; les cellules qui répondent à de faibles quantités d'antigène ont une forte sensibilité. Suite à une première infection virale, les cellules Τ CD8 ont une sensibilité plus faible que lors d'expositions répétées au même virus. En effet, la réexposition au pathogène induit une augmentation de sensibilité, grâce au recrutement et/ou à l'expansion de cellules Τ dotées d'une sensibilité plus élevée. Les cellules Τ CD8 avec une plus haute sensibilité semblent être caractérisées par une perte de fonctionnalité (épuisement fonctionnel associé à une haute expression de molécules dites inhibitrices). En absence d'infection, la fonction des molécules inhibitrices n'est pas encore clairement définie. Les cellules Τ CD8 montrent un niveau d'expression plus élevé de ces molécules par rapport aux cellules Τ CD4. Ceci dépend de l'état des cellules. Parmi ces molécules, le CD160 est associé à l'incapacité des cellules à proliférer et à produire de l'IL-2, une protéine importante pour la prolifération et la survie cellulaire. L'incapacité des cellules exprimant le CD 160 à proliférer en réponse à des virus peut être restaurée par le blocage fonctionnel du récepteur CD 160. Cette étude étoffe notre connaissance du rôle des cellules Τ CD8 ainsi que des conséquences induites par leur épuisement fonctionnel. Ces informations sont fondamentales pour le développement de nouvelles stratégies thérapeutiques et vaccinales.

Toxicological and ultrastructural analysis of the impact of pesticides used in temperate fruit crops on two populations of Chrysoperla externa (Neuroptera, Chrysopidae)

This study aimed to evaluate the effects of (g a.i. L-1) abamectin (0.02), carbaryl (1.73), sulphur (4.8), fenitrothion (0.75), methidathion (0.4), and trichlorfon (1.5) on the survival of larvae and pupae, on the oviposition of adults and hatching of eggs from treated Chrysoperla externa third-instar larvae from two different populations (Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil). Morphological changes caused by abamectin to eggs laid by C. externa from Vacaria population were evaluated by mean of ultrastructural analysis. The pesticides were applied on glass plates. Distilled water was used as control. For the evaluation of larvae mortality, a fully randomized experimental design in a 2 x 7 (two populations x seven treatments) factorial scheme was used, whereas for the effects of the compounds on oviposition capacity and egg viability, a 2 x 4 factorial scheme was used. Carbaryl, fenitrothion, and methidathion caused 100% mortality of larvae. Abamectin reduced the hatching of eggs from treated third-instar larvae of both populations; however, this pesticide presented highest toxicity on insects from Vacaria. The ultrastructural analysis showed that abamectin caused malformations in micropyle and in chorion external surface of C. externa eggs. Based in the total effect (E), carbaryl, fenitrothion, and methidathion are harmful to C. externa; trichlorfon is harmless to third-instar larvae, while abamectin and sulphur are harmless and slightly harmful to third-instar larvae from Bento Gonçalves and Vacaria, respectively.

Combining heat stress and moderate hypoxia reduces cycling time to exhaustion without modifying neuromuscular fatigue characteristics.

PURPOSE: This study investigated the isolated and combined effects of heat [temperate (22 °C/30 % rH) vs. hot (35 °C/40 % rH)] and hypoxia [sea level (FiO2 0.21) vs. moderate altitude (FiO2 0.15)] on exercise capacity and neuromuscular fatigue characteristics. METHODS: Eleven physically active subjects cycled to exhaustion at constant workload (66 % of the power output associated with their maximal oxygen uptake in temperate conditions) in four different environmental conditions [temperate/sea level (control), hot/sea level (hot), temperate/moderate altitude (hypoxia) and hot/moderate altitude (hot + hypoxia)]. Torque and electromyography (EMG) responses following electrical stimulation of the tibial nerve (plantar-flexion; soleus) were recorded before and 5 min after exercise. RESULTS: Time to exhaustion was reduced (P < 0.05) in hot (-35 ± 15 %) or hypoxia (-36 ± 14 %) compared to control (61 ± 28 min), while hot + hypoxia (-51 ± 20 %) further compromised exercise capacity (P < 0.05). However, the effect of temperature or altitude on end-exercise core temperature (P = 0.089 and P = 0.070, respectively) and rating of perceived exertion (P > 0.05) did not reach significance. Maximal voluntary contraction torque, voluntary activation (twitch interpolation) and peak twitch torque decreased from pre- to post-exercise (-9 ± 1, -4 ± 1 and -6 ± 1 % all trials compounded, respectively; P < 0.05), with no effect of the temperature or altitude. M-wave amplitude and root mean square activity were reduced (P < 0.05) in hot compared to temperate conditions, while normalized maximal EMG activity did not change. Altitude had no effect on any measured parameters. CONCLUSION: Moderate hypoxia in combination with heat stress reduces cycling time to exhaustion without modifying neuromuscular fatigue characteristics. Impaired oxygen delivery or increased cardiovascular strain, increasing relative exercise intensity, may have also contributed to earlier exercise cessation.

State power and protected areas: Dynamics and contradictions of forest conservation in Madhya Pradesh, India

The traditionally coercive and state-controlled governance of protected areas for nature conservation in developing countries has in many cases undergone change in the context of widespread decentralization and liberalization. This article examines an emerging "mixed" (coercive, community- and market-oriented) conservation approach in managed-resource protected areas and its effects on state power through a case study on forest protection in the central Indian state of Madhya Pradesh. The findings suggest that imperfect decentralization and partial liberalization resulted in changed forms, rather than uniform loss, of state power. A forest co-management program paradoxically strengthened local capacity and influence of the Forest Department, which generally maintained its territorial and knowledge-based control over forests and timber management. Furthermore, deregulation and reregulation enabled the state to withdraw from uneconomic activities but also implied reduced place-based control of non-timber forest products. Generally, the new policies and programs contributed to the separation of livelihoods and forests in Madhya Pradesh. The article concludes that regulatory, community- and market-based initiatives would need to be better coordinated to lead to more effective nature conservation and positive livelihood outcomes.

Thermal hygrometric requirements for the rearing and release of Tamarixia radiata (Waterston) (Hymenoptera, Eulophidae)

Thermal hygrometric requirements for the rearing and release of Tamarixia radiata (Waterston) (Hymenoptera, Eulophidae). Tamarixia radiata is the main agent for the biological control of Diaphorina citri in Brazil with a parasitism rate ranging from 20 to 80%. This study investigated the influence of temperature on the development, fecundity and longevity of adults of T. radiata and the effect of relative humidity (RH) on their parasitism capacity and survival rate in the pre-imaginal period. The effect of temperature was assessed in the range between 15 and 35 ± 1ºC, 70 ± 10% RH, and a 14-h photophase. The RH effect was evaluated in the range from 30 to 90 ± 10%, temperature at 25 ± 1ºC, and photophase of 14-h. At 25ºC, circa 166.7 nymphs were parasitized, the highest parasitism capacity observed compared to other treatments. The longest longevity of females was observed at 25ºC, although the rate did not differ in the 20-30ºC temperature range. The threshold temperature (TT) was 7.2ºC, and 188.7 degrees-day were required for the development (egg-to-adult period). The parasitism rate and longevity were higher at 50 and 70% of RH. This shows that temperature and RH may affect the parasitism capacity of T. radiata on nymphs of D. citri, which can explain the great parasitism variation for D. citri observed in citrus groves in São Paulo State, Brazil.

Mice carrying ubiquitin-specific protease 2 (Usp2) gene inactivation maintain normal sodium balance and blood pressure.

Ubiquitylation plays an important role in the control of Na⁺ homeostasis by the kidney. It is well established that the epithelial Na⁺ channel ENaC is regulated by the ubiquitin-protein ligase NEDD4-2, limiting ENaC cell surface expression and activity. Ubiquitylation can be reversed by the action of deubiquitylating enzymes (DUBs). One such DUB, USP2-45, was identified previously as an aldosterone-induced protein in the kidney and is also a circadian output gene. In heterologous expression systems, USP2-45 binds to ENaC, deubiquitylates it, and enhances channel density and activity at the cell surface. Because the role of USP2-45 in renal Na⁺ transport had not been studied in vivo, we investigated here the effect of Usp2 gene inactivation in this process. We demonstrate first that USP2-45 protein has a rhythmic expression with a peak at ZT12. Usp2-KO mice did not show any differences from wild-type littermates with respect to the diurnal control of Na⁺ or K⁺ urinary excretion and plasma levels either on a standard diet or after acute and chronic changes to low- and high-Na⁺ diets, respectively. Moreover, they had similar aldosterone levels on either a low- or high-Na⁺ diet. Blood pressure measurements using telemetry did not reveal variations compared with control mice. Usp2-KO mice did not display alterations in expression of genes involved in sodium homeostasis or the ubiquitin system, as evidenced by transcriptome analysis in the kidney. Our data suggest that USP2 does not play a primary role in the control of Na⁺ balance or blood pressure.

Buffer Capacity Allocation: A method to QoS support on MPLS networks

This paper describes an optimized model to support QoS by mean of Congestion minimization on LSPs (Label Switching Path). In order to perform this model, we start from a CFA (Capacity and Flow Allocation) model. As this model does not consider the buffer size to calculate the capacity cost, our model- named BCA (Buffer Capacity Allocation)- take into account this issue and it improve the CFA performance. To test our proposal, we perform several simulations; results show that BCA model minimizes LSP congestion and uniformly distributes flows on the network

Effect of multiple oral doses of androgenic anabolic steroids on endurance performance and serum indices of physical stress in healthy male subjects.

Anabolic androgenic steroids (AAS) are doping agents that are mostly used for improvement of strength and muscle hypertrophy. In some sports, athletes reported that the intake of AAS is associated with a better recovery, a higher training load capacity and therefore an increase in physical and mental performances. The purpose of this study was to evaluate, the effect of multiple doses of AAS on different physiological parameters that could indirectly relate the physical state of athletes during a hard endurance training program. In a double blind settings, three groups (n = 9, 8 and 8) were orally administered placebo, testosterone undecanoate or 19-norandrostenedione, 12 times during 1 month. Serum biomarkers (creatine kinase, ASAT and urea), serum hormone profiles (testosterone, cortisol and LH) and urinary catecholamines (noradrenalin, adrenalin and dopamine) were evaluated during the treatment. Running performance was assessed before and after the intervention phase by means of a standardized treadmill test. None of the measured biochemical variables showed significant impact of AAS on physical stress level. Data from exercise testing on submaximal and maximal level did not reveal any performance differences between the three groups or their response to the treatment. In the present study, no effect of multiple oral doses of AAS on endurance performance or bioserum recovery markers was found.

Determinants of brain cell metabolic phenotypes and energy substrate utilization unraveled with a modeling approach.

Although all brain cells bear in principle a comparable potential in terms of energetics, in reality they exhibit different metabolic profiles. The specific biochemical characteristics explaining such disparities and their relative importance are largely unknown. Using a modeling approach, we show that modifying the kinetic parameters of pyruvate dehydrogenase and mitochondrial NADH shuttling within a realistic interval can yield a striking switch in lactate flux direction. In this context, cells having essentially an oxidative profile exhibit pronounced extracellular lactate uptake and consumption. However, they can be turned into cells with prominent aerobic glycolysis by selectively reducing the aforementioned parameters. In the case of primarily oxidative cells, we also examined the role of glycolysis and lactate transport in providing pyruvate to mitochondria in order to sustain oxidative phosphorylation. The results show that changes in lactate transport capacity and extracellular lactate concentration within the range described experimentally can sustain enhanced oxidative metabolism upon activation. Such a demonstration provides key elements to understand why certain brain cell types constitutively adopt a particular metabolic profile and how specific features can be altered under different physiological and pathological conditions in order to face evolving energy demands.

Assessment of soil properties by organic matter and EM-microorganism incorporation

Properties of a claim loam soil, collected in Aranjuez (Madrid) and enriched with organic matter and microorganisms, were evaluated under controlled temperature and moisture conditions, over a period of three months. The following treatments were carried out: soil (control); soil + 50 t ha-1 of animal manure (E50); soil + 50 t ha-1 of animal manure + 30 L ha-1 of effective microorganisms (E50EM); soil + 30 t ha-1 of the combination of various green crop residues and weeds (RC30) and soil + 30 t ha-1 of the combination of various green crop residues and weeds + 30 L ha-1 of effective microorganisms (RC30EM). Soil samples were taken before and after incubation and their physical, chemical, and microbiological parameters analyzed. Significant increase was observed in the production of exopolysaccharides and basic phosphatase and esterase enzyme activities in the treatments E50EM and RC30EM, in correlation with the humification of organic matter, water retention at field capacity, and the cationic exchange capacity (CEC) of the same treatments. The conclusion was drawn that the incorporation of a mixture of effective microorganisms (EM) intensified the biological soil activity and improved physical and chemical soil properties, contributing to a quick humification of fresh organic matter. These findings were illustrated by the microbiological activities of exopolysaccharides and by alkaline phosphatase and esterase enzymes, which can be used as early and integrated soil health indicators.

Deubiquitylation regulates activation and proteolytic cleavage of ENaC

The epithelial sodium channel (ENaC) is critical for sodium and BP homeostasis. ENaC is regulated by Nedd4-2-mediated ubiquitylation, which leads to its internalization; this process can be reversed by deubiquitylation, which is regulated by the aldosterone-induced enzyme Usp2-45. In a second regulatory pathway, ENaC can be activated by luminal serine protease-mediated cleavage of its extracellular loops. Whether these two regulatory processes interact, however, is unknown. Here, in HEK293 cells stably transfected with ENaC, Usp2-45 interacted with ENaC, leading to deubiquitylation of the channel and stimulation of ENaC activity >20-fold. This was accompanied by a modest increase in cell surface expression of ENaC and by proteolytic cleavage of alphaENaC and gammaENaC at their extracellular loops. When endocytosis was inhibited with dominant negative dynamin (DynK44R), channel density and gammaENaC cleavage were increased, but alphaENaC cleavage and ENaC activity were not augmented. When Usp2-45 was coexpressed with DynK44R, both alphaENaC cleavage and activity were recovered. In summary, these data suggest that Usp2-45 deubiquitylation of ENaC enhances the proteolytic activation of both alphaENaC and gammaENaC, possibly by inducing a conformational change and by interfering with endocytosis, respectively

Stationarity analysis of historical flood series in France and Spain (14th-20th centuries)

Interdisciplinary frameworks for studying natural hazards and their temporal trends have an important potential in data generation for risk assessment, land use planning, and therefore the sustainable management of resources. This paper focuses on the adjustments required because of the wide variety of scientific fields involved in the reconstruction and characterisation of flood events for the past 1000 years. The aim of this paper is to describe various methodological aspects of the study of flood events in their historical dimension, including the critical evaluation of old documentary and instrumental sources, flood-event classification and hydraulic modelling, and homogeneity and quality control tests. Standardized criteria for flood classification have been defined and applied to the Isère and Drac floods in France, from 1600 to 1950, and to the Ter, the Llobregat and the Segre floods, in Spain, from 1300 to 1980. The analysis on the Drac and Isère data series from 1600 to the present day showed that extraordinary and catastrophic floods were not distributed uniformly in time. However, the largest floods (general catastrophic floods) were homogeneously distributed in time within the period 1600¿1900. No major flood occurred during the 20th century in these rivers. From 1300 to the present day, no homogeneous behaviour was observed for extraordinary floods in the Spanish rivers. The largest floods were uniformly distributed in time within the period 1300-1900, for the Segre and Ter rivers.

Effects of thyroid hormones and aldosterone on mineralocorticoid binding sites in the toad bladder.

In the urinary bladder of the toad Bufo marinus triiodothyronine selectively inhibits the late effect of aldosterone on Na+ transport. We have investigated whether T3 might mediate its antimineralocorticoid action by controlling: i) the level of aldosterone binding sites in the soluble (cytosolic) pool isolated from tissues treated with T3 (60 nM) for up to 20 hr of incubation; ii) the kinetics of uptake of 3H-aldosterone into cytoplasmic and nuclear fractions after 2 or 20 hr of exposure to T3. The number and the affinity of Type I (high affinity, low capacity) and Type II (low affinity, high capacity) cytosolic binding sites (measured at 0 degrees C) did not vary significantly after 18 hr of exposure to T3, while aldosterone-dependent Na+ transport was significantly inhibited. In addition, T3 did not modify the kinetics of uptake (90 min) of 3H-aldosterone into cytoplasmic and nuclear fractions of toad bladder incubated in vitro at 25 degrees C. By contrast, aldosterone itself was able to down-regulate its cytosolic and nuclear binding sites after an 18-hr exposure to the steroid hormone (10 or 80 nM). T3 slightly (20%) but significantly potentiated the down regulation of nuclear binding sites. In conclusion, T3 does not appear to have major effects on the regulation of the aldosterone receptor, which could explain in a simple manner its antimineralocorticoid action.

Record of Decision, Council Bluffs Interstate System(I-29, I-80 and I-480) Improvements Project, October 15, 2005

The Federal Highway Administration (FHWA) approves the selection of the Reconstruction of All or Part of the Interstate (Construction Alternative) as the Preferred Alternative to provide improvements to the interstate system in the Omaha/Council Bluffs metropolitan area, extending across the Missouri River on Interstate 80 to east of the Interstate 480 interchange in Omaha, Nebraska. The study considered long-term, broad-based transportation improvements along Interstate I-29 (I-29), I-80, and I-480, including approximately 18 mainline miles of interstate and 14 interchanges (3 system, 11 service), that would add capacity and correct functional issues along the mainline and interchanges and upgrade the I-80 Missouri River Crossing.