Hierarchical Work-Stealing

In this paper, we study the problem of dynamic load-balancing on heterogeneous hierarchical platforms. In particular, we consider here applications involving heavy communications on a distributed platform. The work-stealing algorithm introduced by Blumofe and Leiserson is a commonly used technique to distribute load in a distributed environment but it suffers from poor performances in some cases of communications-intensive applications. We present here several variants of this algorithm found in the literature and different grid middlewares like Satin and Kaapi. In addition, we propose two new variations of the work-stealing algorithm : HWS and PWS. These algorithms improve performances by taking the networking structure into account within the scheduling. We conduct a theoretical analysis of HWS in the case of fork-join task graphs and present experimental results comparing the most relevant algorithms. Experiments on Grid'5000 show that HWS and PWS allow us to obtain performance gains of up to twenty per cent when compared to the standard algorithm. Moreover in some case, the standard algorithm reaches worse performances on the distributed platform than on a single machine while PWS and HWS achieve some speedup

Nerve Transfers to Recover External Rotation of the Shoulder after Brachial Plexus Injuries in Adults

Restoration of external rotation of the shoulder in adults with partial brachial plexus palsies is challenging. While nerve grafts are possible, nerve transfers are currently the most use method for satisfactory restoration of function. Numerous nerve transfers have been described, although the transfer of the spinal accessory nerve to the suprascapular nerve remains the gold standard. The suprascapular nerve and the nerve to the teres minor muscle are the two preferred targets to restore external rotation of the shoulder. There are numerous nerve donors, but their use obviously depends on the initial injury. The most common donors are the spinal accessory nerve, the rhomboid nerve, branches of the radial nerve, the C7 root fascicle or the ulnar nerve. The choice for the transfer depends on the available nerves and first of all on chosen approach, whether it be cervical or scapular. It also depends on the other associated reconstruction procedures, grafts, or nerve transfers for the recovery of other functions, specifically, elevation of the shoulder and flexion of the elbow. The objective of this chapter is to present the main nerve transfers and to propose a therapeutic strategy

Effectiveness of third-trimester ultrasound screening in the prediction of small for gestational age neonates: a retrospective cohort study

editorial reviewe

Can patients with central field loss perform head pointing in a virtual reality environment?

International audienceIntroduction: Virtual Reality (VR) headsets are raising more and more interest from the low-vision research community since they offer a promising framework for low-vision aids and rehabilitation protocols. However, the study of VR accessibility to low vision is still in its early stages and designing efficient user interfaces for low-vision users remains an open challenge. Head pointing (a common way to interact with the world in VR environments) may represent a promising option for patients with Central Field Loss (CFL) who lose the ability to direct their gaze efficiently towards a target. Yet, little is known about the actual head-pointing capacities of CFL patients.Discussion: The purpose of the current study is to evaluate whether patients with CFL are able to perform precise head-pointing tasks in VR. 49 patients with binocular CFL, aged 34 to 97 (mean = 77±13), were tested with an Oculus Go headset in a very simple VR environment (grey background). At the beginning of each block, a head-contingent reticle was displayed in a specific location in front of the patient. A total of 9 reticle locations were tested either in the center of the visual field or with a 7° offset. At each trial, a target appeared in the visual field and patients were instructed to move their head to position the reticle precisely onto the target. Targets were black circles (1° to 3° diameter) randomly presented in five fixed positions (center or top, right, bottom, left at 18° of eccentricity). On average, patients were able to use their head to position the reticle precisely onto the target 94% of the time. Individual differences emerged, with a significant drop in pointing speed performance for specific reticle locations.Conclusions: Our preliminary results show that patients with CFL are able to perform accurately precise head-pointing tasks. This represents a fundamental step towards the design of efficient and user-friendly visual aids and rehabilitation tools using VR. For instance, head pointing could provide an ergonomic framework to design user interfaces that require precise pointing abilities to perform item selection. Similarly, one can imagine designing head-contingent pointing exercises that will drive the rehabilitation process while limiting straining of the eyes

Curative effect of second curettage for treatment of gestational trophoblastic disease - Results of the Belgian registry for gestational trophoblastic disease.

peer reviewedOBJECTIVE: We assessed the curative effect of a second curettage in patients with persistent hCG serum levels after first curettage for a gestational trophoblastic disease (GTD). STUDY DESIGN: This prospective observational study used the data of the Belgian register for GTD between July 2012 and January 2017. We analysed the data of patients who underwent a second curettage. We included 313 patients in the database. Primary endpoints were need for second curettage and chemotherapy. RESULTS: Thirty-seven patients of the study population (12 %) underwent a second curettage. 20 had persistent human chorionic gonadotropin hormone (hCG) elevation before second curettage. Of them, 9 patients (45 %) needed no further treatment afterwards. Eleven patients (55 %) needed further chemotherapy. Nine (82 %) were cured with single-agent chemotherapy and 2 patients (18 %) needed multi-agent chemotherapy. Of the 37 patients, patients with hCG levels below 5000 IU/L undergoing a second curettage were cured without chemotherapy in 65 % versus 45 % of patients with hCG level more than 5000 IU/L. Of the ten patients with a hCG level below 1000 IU/L, eight were cured without chemotherapy. CONCLUSIONS: Patients with post-mole gestational trophoblastic neoplasia can benefit from a second curettage to avoid chemotherapy, especially when the hCG level is lower than 5000 IU/L

Real-Time Assessment of Health-Care Requirements During the Zika Virus Epidemic in Martinique.

The spread of Zika virus in the Americas has been associated with a surge in Guillain-Barré syndrome (GBS) cases. Given the severity of GBS, territories affected by Zika virus need to plan health-care resources to manage GBS patients. To inform such planning in Martinique, we analyzed Zika virus surveillance and GBS data from Martinique in real time with a modeling framework that captured dynamics of the Zika virus epidemic, the risk of GBS in Zika virus-infected persons, and the clinical management of GBS cases. We compared our estimates with those from the 2013-2014 Zika virus epidemic in French Polynesia. We were able to predict just a few weeks into the epidemic that, due to lower transmission potential and lower probability of developing GBS following infection in Martinique, the total number of GBS cases in Martinique would be substantially lower than suggested by simple extrapolations from French Polynesia. We correctly predicted that 8 intensive-care beds and 7 ventilators would be sufficient to treat GBS cases. This study showcased the contribution of modeling to inform local health-care planning during an outbreak. Timely studies that estimate the proportion of infected persons that seek care are needed to improve the predictive power of such approaches

BEEHOPE: um projeto de conservação das subespécies nativas de abelha da Europa Ocidental (linhagem M) à escala Europeia

O projeto BEEHOPE, com o título original “Honeybee conservation centres in western Europe - an innovative strategy using sustainable beekeeping to reduce honeybee decline”, foi um dos 10 aprovados na área da biodiversidade do 5º concurso transnacional (2013-2014) BiodivErsA/FACCE-JPI (http://www.biodiversa.org/766), subordinado ao tema “Promover sinergias e reduzir o compromisso entre o abastecimento de alimentos, biodiversidade e serviços dos ecossistemas”. A diversidade nativa das populações de abelha melífera (Apis mellifera) da linhagem da Europa ocidental (M) tem vindo a ser crescentemente ameaçada pela introdução massiva de colónias da linhagem da Europa oriental (C, onde se incluem as subespécies A. m. ligustica, A. m. carnica, A. m. macedónica etc.), e também por outros fatores bióticos (Varroa e vírus associados, Nosema etc.) e abióticos (pesticidas, perda e fragmentação de habitat, alterações climáticas etc.). É neste contexto que surge o projeto BEEHOPE, o qual tem por objetivo último contribuir para a conservação da diversidade genética das populações de abelha melífera da linhagem M.info:eu-repo/semantics/publishedVersio

National CO\u3csub\u3e2\u3c/sub\u3e budgets (2015-2020) inferred from atmospheric CO\u3csub\u3e2\u3c/sub\u3e observations in support of the global stocktake

Accurate accounting of emissions and removals of CO2 is critical for the planning and verification of emission reduction targets in support of the Paris Agreement. Here, we present a pilot dataset of country-specific net carbon exchange (NCE; fossil plus terrestrial ecosystem fluxes) and terrestrial carbon stock changes aimed at informing countries\u27 carbon budgets. These estimates are based on top-down NCE outputs from the v10 Orbiting Carbon Observatory (OCO-2) modeling intercomparison project (MIP), wherein an ensemble of inverse modeling groups conducted standardized experiments assimilating OCO-2 column-Averaged dry-Air mole fraction (XCO2) retrievals (ACOS v10), in situ CO2 measurements or combinations of these data. The v10 OCO-2 MIP NCE estimates are combined with bottom-up estimates of fossil fuel emissions and lateral carbon fluxes to estimate changes in terrestrial carbon stocks, which are impacted by anthropogenic and natural drivers. These flux and stock change estimates are reported annually (2015-2020) as both a global 1gg×g1g gridded dataset and a country-level dataset and are available for download from the Committee on Earth Observation Satellites\u27 (CEOS) website: 10.48588/npf6-sw92 . Across the v10 OCO-2 MIP experiments, we obtain increases in the ensemble median terrestrial carbon stocks of 3.29-4.58gPgCO2yr-1 (0.90-1.25gPgCyr-1). This is a result of broad increases in terrestrial carbon stocks across the northern extratropics, while the tropics generally have stock losses but with considerable regional variability and differences between v10 OCO-2 MIP experiments. We discuss the state of the science for tracking emissions and removals using top-down methods, including current limitations and future developments towards top-down monitoring and verification systems