Architecture and growth strategy of two evergreen species of the Western Ghats (South India). Knema attenuata (Myristicaceae) and Vateria indica (Dipterocarpaceae)

Analysing tree architecture consists in describing the successive growth stages from the seedling to the death of plants. The description and monitoring of the different types of axes (stem, branches, twigs, etc.) and lateral productions (flowers, leaves, etc.) helps in characterising the structural growth strategies. In this paper, I describe and interpret the architectural development of two species: Vateria indica (Dipterocarpaceae), an emergent, and Knema attenuata (Myristicaceae), a lower canopy species. These two species are among the most frequent species of the low elevation moist evergreen forests of the Western Ghats in South India. They were observed in the Kadamakal Reserve Forest (Coorg District, Karnataka State). Both species conform to Massart's architectural model but exhibit different ways of building up their crown and different strategies of reiteration in response to light availability in order to maintain their growth under canopy: K. attenuata reinforces its structure from the very early stage and maintains its position of a lower canopy tree through its very regular structure until it reaches the canopy, while V. indica establishes its structure once it reaches this limit. The aim of this paper is to show how two species which belong to two different vertical strata, grow and adapt in the light-limited forest environment and to describe by which way they manage to reach the canopy and intercept light

Modeling tree architecture and forest dynamics. A research project in the dense moist evergreen forests of the Western Ghats (South India)

This working paper presents a research programme which aims at modelling the dynamics of the dense moist evergreen forests of the Western Ghats (India) from analysing, modelling and simulating tree architecture. The paper first reviews various approaches to modelling the dynamics of heterogeneous forests, either temperate or tropical: demographic matrix models, distance-dependent tree growth models, gap models, cellular automata and multiagent systems. The advantages and drawbacks of the architectural approach are then discussed. The proposed study site is then briefly presented and a programme is outlined: selection of some species which are both frequent and representative of the different forest strata, sampling strategy and measurements, methods used for modelling and computer simulation. The preliminary results obtained since the project was started in early 1995 are then briefly reviewed; a more detailed account will soon be published in another paper of this series

Decrease in Fas-induced apoptosis by the γ-secretase inhibitor is dependent on p75(NTR) in a glioblastoma cell line.

International audiencep75(NTR), a member of the tumor necrosis factor superfamily, plays a key role in numerous physiological processes, including cell survival or apoptosis. Yet, the associated signaling pathways remain poorly understood. Similar to Notch, γ-secretase cleavage is implicated in the p75(NTR) signaling pathway leading to nuclear translocation of the intracellular domain and cell death. Fas receptor activation was found to promote cell death apoptosis in several cell lines. The goal of this study was to determine the respective role of p75(NTR) and Notch in the resistance to Fas-induced apoptosis in the U-87 MG glioblastoma cell line. Using the γ-secretase inhibitor, we investigated the modulation of Fas-induced apoptosis dependent on p75(NTR)-Fas receptor interaction. Whereas the U-87 MG cells expressed the Fas receptor at the cell membrane, apoptosis induced by Fas activation was decreased by the γ-secretase inhibitor. These data suggest that γ-secretase is implicated in p75(NTR) and Fas interaction leading to cell death signaling

Una aproximación estética a la presentación satírica de la raza, la mujer y las relaciones adolescentes americanas en el guion, los vestuarios y la dirección de actores de la película Mean Girls desde la perspectiva de Davis Ryalls

Este trabajo se propone hacer un análisis estético de los temas más prominentes en la película satírica Mean Girls, que se estrenó en el 2004. La base de la película es más profunda de lo que aparenta a primera vista. Es por eso que este trabajo busca analizarla desde tres puntos básicos: la manera en que la raza es presentada, las representaciones de la mujer y la manera en que estas interactúan; siempre teniendo en cuenta que todo esto se sitúa en el universo cultural americano. Para ello se partirá siempre desde un análisis de la sátira misma y su relación con la estética, ya que la consideramos un componente importante en dicha película

M comme mère, M comme monstre

De tout temps, la monstruosité des mères a suscité l’intérêt de la société. Déclenchant les débats éthiques, des déchaînements médiatiques, elle est aussi à l’origine d’un nombre impressionnant d’œuvres artistiques complexes

AAV-mediated intramuscular delivery of myotubularin corrects the myotubular myopathy phenotype in targeted murine muscle and suggests a function in plasma membrane homeostasis

Myotubular myopathy (XLMTM, OMIM 310400) is a severe congenital muscular disease due to mutations in the myotubularin gene (MTM1) and characterized by the presence of small myofibers with frequent occurrence of central nuclei. Myotubularin is a ubiquitously expressed phosphoinositide phosphatase with a muscle-specific role in man and mouse that is poorly understood. No specific treatment exists to date for patients with myotubular myopathy. We have constructed an adeno-associated virus (AAV) vector expressing myotubularin in order to test its therapeutic potential in a XLMTM mouse model. We show that a single intramuscular injection of this vector in symptomatic Mtm1-deficient mice ameliorates the pathological phenotype in the targeted muscle. Myotubularin replacement in mice largely corrects nuclei and mitochondria positioning in myofibers and leads to a strong increase in muscle volume and recovery of the contractile force. In addition, we used this AAV vector to overexpress myotubularin in wild-type skeletal muscle and get insight into its localization and function. We show that a substantial proportion of myotubularin associates with the sarcolemma and I band, including triads. Myotubularin overexpression in muscle induces the accumulation of packed membrane saccules and presence of vacuoles that contain markers of sarcolemma and T-tubules, suggesting that myotubularin is involved in plasma membrane homeostasis of myofibers. This study provides a proof-of-principle that local delivery of an AAV vector expressing myotubularin can improve the motor capacities of XLMTM muscle and represents a novel approach to study myotubularin function in skeletal muscle

Parasite Population Genetic Contributions to the Schistosomiasis Consortium for Operational Research and Evaluation within Sub-Saharan Africa

Analyses of the population genetic structure of schistosomes under the “Schistosomiasis Consortium for Operational Research and Evaluation” (SCORE) contrasting treatment pressure scenarios in Tanzania, Niger, and Zanzibar were performed to provide supplementary critical information with which to evaluate the impact of these large-scale control activities and guide how activities could be adjusted. We predicted that population genetic analyses would reveal information on a range of important parameters including, but not exclusive to, recruitment and transmission of genotypes, occurrence of hybridization events, differences in reproductive mode, and degrees of inbreeding, and hence, the evolutionary potential, and responses of parasite populations under contrasting treatment pressures. Key findings revealed that naturally high levels of gene flow and mixing of the parasite populations between neighboring sites were likely to dilute any effects imposed by the SCORE treatment arms. Furthermore, significant inherent differences in parasite fecundity were observed, independent of current treatment arm, but potentially of major impact in terms of maintaining high levels of ongoing transmission in persistent “biological hotspot” sites. Within Niger, naturally occurring Schistosoma haematobium/Schistosoma bovis viable hybrids were found to be abundant, often occurring in significantly higher proportions than that of single-species S. haematobium infections. By examining parasite population genetic structures across hosts, treatment regimens, and the spatial landscape, our results to date illustrate key transmission processes over and above that which could be achieved through standard parasitological monitoring of prevalence and intensity alone, as well as adding to our understanding of Schistosoma spp. life history strategies in general

Practical Recommendations for Optimal Thromboprophylaxis in Patients with COVID-19: A Consensus Statement Based on Available Clinical Trials.

Coronavirus disease 2019 (COVID-19) has been shown to be strongly associated with increased risk for venous thromboembolism events (VTE) mainly in the inpatient but also in the outpatient setting. Pharmacologic thromboprophylaxis has been shown to offer significant benefits in terms of reducing not only VTE events but also mortality, especially in acutely ill patients with COVID-19. Although the main source of evidence is derived from observational studies with several limitations, thromboprophylaxis is currently recommended for all hospitalized patients with acceptable bleeding risk by all national and international guidelines. Recently, high quality data from randomized controlled trials (RCTs) further support the role of thromboprophylaxis and provide insights into the optimal thromboprophylaxis strategy. The aim of this statement is to systematically review all the available evidence derived from RCTs regarding thromboprophylaxis strategies in patients with COVID-19 in different settings (either inpatient or outpatient) and provide evidence-based guidance to practical questions in everyday clinical practice. Clinical questions accompanied by practical recommendations are provided based on data derived from 20 RCTs that were identified and included in the present study. Overall, the main conclusions are: (i) thromboprophylaxis should be administered in all hospitalized patients with COVID-19, (ii) an optimal dose of inpatient thromboprophylaxis is dependent upon the severity of COVID-19, (iii) thromboprophylaxis should be administered on an individualized basis in post-discharge patients with COVID-19 with high thrombotic risk, and (iv) thromboprophylaxis should not be routinely administered in outpatients. Changes regarding the dominant SARS-CoV-2 variants, the wide immunization status (increasing rates of vaccination and reinfections), and the availability of antiviral therapies and monoclonal antibodies might affect the characteristics of patients with COVID-19; thus, future studies will inform us about the thrombotic risk and the optimal therapeutic strategies for these patients

Commissioning and operation of the readout system for the solid neutrino detector

The SoLid experiment aims to measure neutrino oscillation at a baseline of 6.4 m from the BR2 nuclear reactor in Belgium. Anti-neutrinos interact via inverse beta decay (IBD), resulting in a positron and neutron signal that are correlated in time and space. The detector operates in a surface building, with modest shielding, and relies on extremely efficient online rejection of backgrounds in order to identify these interactions. A novel detector design has been developed using 12800 5 cm cubes for high segmentation. Each cube is formed of a sandwich of two scintillators, PVT and 6LiF:ZnS(Ag), allowing the detection and identification of positrons and neutrons respectively. The active volume of the detector is an array of cubes measuring 80x80x250 cm (corresponding to a fiducial mass of 1.6 T), which is read out in layers using two dimensional arrays of wavelength shifting fibres and silicon photomultipliers, for a total of 3200 readout channels. Signals are recorded with 14 bit resolution, and at 40 MHz sampling frequency, for a total raw data rate of over 2 Tbit/s. In this paper, we describe a novel readout and trigger system built for the experiment, that satisfies requirements on: compactness, low power, high performance, and very low cost per channel. The system uses a combination of high price-performance FPGAs with a gigabit Ethernet based readout system, and its total power consumption is under 1 kW. The use of zero suppression techniques, combined with pulse shape discrimination trigger algorithms to detect neutrons, results in an online data reduction factor of around 10000. The neutron trigger is combined with a large per-channel history time buffer, allowing for unbiased positron detection. The system was commissioned in late 2017, with successful physics data taking established in early 2018

Ploidy of Cell-Sorted Trophic and Cystic Forms of Pneumocystis carinii

Once regarded as an AIDS-defining illness, Pneumocystis pneumonia (PcP) is nowadays prevailing in immunocompromised HIV-negative individuals such as patients receiving immunosuppressive therapies or affected by primary immunodeficiency. Moreover, Pneumocystis clinical spectrum is broadening to non-severely-immunocompromised subjects who could be colonized by the fungus while remaining asymptomatic for PcP, thus being able to transmit the infection by airborne route to susceptible hosts. Although the taxonomical position of the Pneumocystis genus has been clarified, several aspects of its life cycle remain elusive such as its mode of proliferation within the alveolus or its ploidy level. As no long-term culture model exists to grow Pneumocystis organisms in vitro, an option was to use a model of immunosuppressed rat infected with Pneumocystis carinii and sort life cycle stage fractions using a high-through-put cytometer. Subsequently, ploidy levels of the P. carinii trophic and cystic form fractions were measured by flow cytometry. In the cystic form, eight contents of DNA were measured thus strengthening the fact that each mature cyst contains eight haploid spores. Following release, each spore evolves into a trophic form. The majority of the trophic form fraction was haploid in our study. Some less abundant trophic forms displayed two contents of DNA indicating that they could undergo (i) mating/fusion leading to a diploid status or (ii) asexual mitotic division or (iii) both. Even less abundant trophic forms with four contents of DNA were suggestive of mitotic divisions occurring following mating in diploid trophic forms. Of interest, was the presence of trophic forms with three contents of DNA, an unusual finding that could be related to asymmetrical mitotic divisions occurring in other fungal species to create genetic diversity at lower energetic expenses than mating. Overall, ploidy data of P. carinii life cycle stages shed new light on the complexity of its modes of proliferation