271 research outputs found

    Introducing QoS support in Bluetooth Piconetwith a Class-Based EDF Scheduling

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    In this paper, we focus on the Bluetooth wireless network, analyzing its ability to support Quality of Service (QoS) requirements defined by the application. In particular, we are interested in two QoS parameters: (i) an application constraint denoting the importance degree of a message, and (ii) its delivery deadline. The QoS perceived by the application depends on the efficiency of the scheduling schemes chosen at the medium access layer. We define the minimal knowledge level required by a scheduling scheme to support these QoS constraints. As an example of classical scheduling schemes, we analyze performances of One-Round Robin (1-RR) and show that it does not provide a sufficient service differentiation. To achieve better service differentiation, we first present enhancements accounting locally for the two QoS parameters. These enhancements are applied to 1-RR scheduling scheme and we then give a comparison between the two versions. These comparisons are done by evaluating in each class, the average message response time and the percentage of messages missing their deadline. We then introduce enhancements in the intra-piconet scheduling. So, we define a new Bluetooth global scheduling, called Class-Based Earliest Deadline First (CB-EDF) that takes into account both locally and globally these two QoS parameters. Simulation results show that CB-EDF achieves a good service differentiation and allows the coexistence of messages with different application constraints on the same ACL link. Moreover, CB-EDF is a flexible solution that adapts itself to the provided knowledge level

    North Atlantic western boundary currents are intense dissolved organic carbon streams

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    In the North Atlantic, there are two main western boundary currents related to the Atlantic Meridional Overturning Circulation (AMOC): the Gulf Stream flowing northward and the Deep Western Boundary Current (DWBC) flowing southward. Here we analyze data from the OVIDE section (GO-SHIP A25 Portugal-Greenland 40-60 degrees N) that crosses the DWBC and the northward extension of the Gulf Stream, the North Atlantic Current. We show that North Atlantic western boundary currents play a key role in the transport of dissolved organic matter, specifically dissolved organic carbon (DOC). Revisited transports and budgets of DOC with new available data identify the eastern Subpolar North Atlantic (eSPNA) as an important source of locally produced organic matter for the North Atlantic and a key region in the supply of bioavailable DOC to the deep ocean. The East Greenland Current, and its upstream source the East Reykjanes Ridge Current on the eastern flank of the mid-Atlantic ridge, are export pathways of bioavailable DOC toward subtropical latitudes. The fast overturning and subsequent remineralization of DOC produced in the autotrophic eSPNA explains up to 38% of the total oxygen consumption in the deep North Atlantic between the OVIDE section and 24 degrees N. Carbon budgets that do not take into account this organic remineralization process overestimates the natural uptake of carbon dioxide (CO2) from the atmosphere by one third. The inclusion of DOC transports in regional carbon budgets reconciles the estimates of CO2 uptake in the North Atlantic between model and observations.FCT: UID/Multi/04326/2019/ CEECINST/00114/2018.info:eu-repo/semantics/publishedVersio

    The GEOVIDE cruise in May-June 2014 reveals an intense Meridional Overturning Circulation over a cold and fresh subpolar North Atlantic

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    The GEOVIDE cruise was carried out in the subpolar North Atlantic (SPNA) along the OVIDE section and across the Labrador Sea in May-June 2014. It was planned to clarify the distribution of the trace elements and their isotopes in the SPNA as part of the GEOTRACES international program. This paper focuses on the state of the circulation and distribution of thermohaline properties during the cruise. In terms of circulation, the comparison with the 2002-2012 mean state shows a more intense Irminger Current and also a weaker North Atlantic Current, with a transfer of volume transport from its northern to its central branch. However, those anomalies are compatible with the variability already observed along the OVIDE section in the 2000s. In terms of properties, the surface waters of the eastern SPNA were much colder and fresher than the averages over 2002-2012. In spite of negative temperature anomalies in the surface waters, the heat transport across the OVIDE section estimated at 0.56±0.06PW was the largest measured since 2002. This relatively large value is related to the relatively strong Meridional Overturning Circulation measured across the OVIDE section during GEOVIDE (18.7±3.0Sv). By analyzing the air-sea heat and freshwater fluxes over the eastern SPNA in relation to the heat and freshwater content changes observed during 2013 and 2014, we concluded that on a short timescale these changes were mainly driven by air-sea heat and freshwater fluxes rather than by ocean circulation

    Zip4/Spo22 Is Required for Class I CO Formation but Not for Synapsis Completion in Arabidopsis thaliana

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    In budding yeast meiosis, the formation of class I interference-sensitive crossovers requires the ZMM proteins. These ZMM proteins are essential in forming a mature synaptonemal complex, and a subset of these (Zip2, Zip3, and Zip4) has been proposed to compose the core of synapsis initiation complexes (SICs). Zip4/Spo22 functions with Zip2 to promote polymerization of Zip1 along chromosomes, making it a crucial SIC component. In higher eukaryotes, synapsis and recombination have often been correlated, but it is totally unknown how these two processes are linked. In this study, we present the characterization of a higher eukaryote SIC component homologue: Arabidopsis AtZIP4. We show that mutations in AtZIP4 belong to the same epistasis group as Atmsh4 and eliminate approximately 85% of crossovers (COs). Furthermore, genetic analyses on two adjacent intervals of Chromosome I established that the remaining COs in Atzip4 do not show interference. Lastly, immunolocalization studies showed that polymerization of the central element of the synaptonemal complex is not affected in Atzip4 background, even if it may proceed from fewer sites compared to wild type. These results reveal that Zip4 function in class I CO formation is conserved from budding yeast to Arabidopsis. On the other hand, and contrary to the situation in yeast, mutation in AtZIP4 does not prevent synapsis, showing that both aspects of the Zip4 function (i.e., class I CO maturation and synapsis) can be uncoupled

    Bringing patient advisors to the bedside: a promising avenue for improving partnership between patients and their care team

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    This paper presents an innovative model of care, which brings patients who have already been through a similar experience of illness (patient advisors) directly to the bedside of patients, where they are viewed as full-fledged members of the clinical team. As part of a pilot project, three patient advisors were recruited and met with patients who had sustained a traumatic amputation and were admitted to the only center of expertise in replantation of the upper limb in Canada. Several individual interviews and focus groups with patients and patient advisors have revealed very promising results. Indeed, patients have expressed tremendous appreciation for their meetings and interactions with patient advisors. They have stated feeling less isolated, having a better morale and increased hopefulness regarding the outcome of the care pathway. Patient advisors also felt a positive impact of their involvement. A larger study needs to be conducted to determine the impact of this model of care on patient adherence to treatment and on members of the health care team

    Upper Pleistocene comparativeOSL, U/Th and 14C datings of sedimentary sequences and correlative morphodynamical implications in the South-Western Anti-Atlas (Oued Noun, 29° N, Morocco)

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    The lower Oued Noun valley, in the arid region of the Atlantic SW Anti-Atlas, contains an extensive Soltanian (= Upper Pleistocene pro-parte) terrace. The paper presents dates for these deposits and an interpretation of their fluvial dynamic and morpho-climatic geneses in this distal part of the valley.The Soltanian terrace, about 30 m thick at Fort Oued Noun, consists of 3 units: a basal deposit of coarse gravel buried by slope deposits and travertine (Unit 1); a main unit, more than 20 m thick (Unit 2) that consists of at least 7 repeated sequences each comprising basal fine gravels and sands, associated with detrital travertine, overlain by stromatolithic tufa and finally by a thick accumulation of sandy silts. These silts were deposited by suspension and decantation in shallow non-turbulent water bodies. The gravels, sands and travertines are more prominent at the bottom and in the upper parts of Unit 2 whilst silts dominate the mid members. Middle Paleolithic artefacts and bones of large mammals are found throughout this Unit.Unit 3, at the top of the formation, comprises red silts that differ from those of Unit 2, containing more aeolian grains and more palygorskyte and being spatially associated with adjacent tributaries fans.Radiometric dates were obtained on travertine (U/Th), on quartz grains extracted from sediments (OSL) and on Melanopsis and Charcoal (14C). U/Th results show three travertine constructions at ca 90, 55-50 and 25-20 ka B.P. The 90 ka dates, however, are not in correct stratigraphic position. The OSL dates suggest that the period of silt aggradation of Unit 2 occured between ca. 50 and 25 ka B.P., the main part of them being deposited between 40 and 30 ka B.P. 14C dates from the upper part of Unit 2 and the base of Unit 3, range between ca 28 and 18 ka B.P. These dates, together with geomorphological and sedimentological analyses, indicate that the valley floor had been lowered to its present depth before ca. 90 ka B.P. However, the slope deposits, older travertines and the basal gravel (Unit 1), classic fluvial and colluvial deposits, are not yet securely dated but they possibly correspond with wetter episodes in O.I.S. stages 5b, 5a and 4, or even later. The silts that form the bulk of Unit 2 were deposited into shallow swamps during biostasic episodes of O.I.S. 3 and were associated with high groundwater levels. Then, large mammals found grass and water along the valley and were hunted by Middle Paleolithic people. The water table remained high after 30 ka B.P. and the gravel-bed channels of the local tributaries were active during the 30-20 ka B.P. period. After ca. 20 ka, sediments suggest more varied conditions in this part of the valley, vegetation disappeared and soils were reworked into local colluvial fans, with concomitant aeolian deposits (Unit 3, O.I.S. 2). Finally, deep linear incision occured dissecting the Soltanian aggraded valley floor during the early Holocene.La basse vallĂ©e de l'oued Noun, aujourd'hui situĂ©e dans le domaine aride du versant sud de l'Anti-Atlas, montre une terrasse soltanienne (PlĂ©istocĂšne supĂ©rieur pro-parte) bien dĂ©veloppĂ©e. Les objectifs de cet article sont de dĂ©terminer avec prĂ©cision les Ăąges des sĂ©diments et de comprendre les changements de la dynamique fluviale, avec ses phases successives d’aggradation et d’érosion, Ă  la fin du PlĂ©istocĂšne supĂ©rieur.La formation soltanienne, Ă©paisse de 30 m Ă  Fort Oued Noun, se compose de 3 unitĂ©s : un dĂ©pĂŽt conglomĂ©ratique de base surmontĂ© par des dĂ©pĂŽts de pente et Ă  des travertins (Unité 1) ; un dĂ©pĂŽt principal de plus de 20 m (Unité 2), qui consiste en au moins 7 sĂ©quences rĂ©pĂ©titives montrant chacune Ă  la base des petits galets et des sables associĂ©s Ă  des travertins dĂ©tritiques, surmontĂ©s de travertins stromatolithiques construits finalement recouverts d'accumulations Ă©paisses de limons. Ces limons ont Ă©tĂ© dĂ©posĂ©s par suspension et dĂ©cantation dans des eaux calmes et peu profondes. Les galets, sables et travertins sont surtout frĂ©quents Ă  la base et au sommet de l’Unité 2, tandis que les limons dominent dans sa partie moyenne. Dans toute l’Unité 2, on trouve des ossements de grands mammifĂšres et des outillages lithiques du PalĂ©olithique moyen. Au sommet de la formation, des limons rouges supĂ©rieurs (Unité 3) diffĂšrent des prĂ©cĂ©dents et appartiennent Ă  des cĂŽnes dĂ©posĂ©s par les affluents locaux, avec davantage de grains Ă©oliens et de palygorskyte.Les datations radiomĂ©triques ont Ă©tĂ© obtenues  pour des travertins (U/Th), des grains de quartz extraits des sĂ©diments (OSL), des charbons et Melanopsis (14C). Les datations U/Th montrent trois pĂ©riodes de construction de travertins autour de 90, 55-50 et 25-20 ka B.P. Les rĂ©sultats Ă  90 ka ne sont toutefois pas en bon accord avec la stratigraphie. D'aprĂšs les rĂ©sultats OSL, la pĂ©riode d'aggradation des silts de l'UnitĂ© 2 se situe entre environ 50 et 25 ka B.P., la majeure partie de ces silts se dĂ©posant entre 40 et 30 ka B.P. Les datations 14C se rangent entre 28 et 18 ka B.P. Elles concernent la partie supĂ©rieure de l'Unité 2 et la partie basale de l'Unité 3.Ces rĂ©sultats, associĂ©s aux observations gĂ©omorphologiques et sĂ©dimentologiques, montrent que la vallĂ©e Ă©tait dĂ©jĂ  creusĂ©e autour de 90 ka B.P. Les dĂ©pĂŽts de pente, les plus anciens travertins et le dĂ©pĂŽt basal graveleux, ayant tous une signature de dĂ©pĂŽts colluviaux ou alluviaux classiques, ne sont pas datĂ©s avec sĂ»reté ; ils peuvent correspondre Ă  des Ă©pisodes humides des stages isotopiques 5b, 5a et 4, mais peuvent aussi ĂȘtre plus rĂ©cents. Les silts qui forment la masse de l'Unité 2 ne peuvent ĂȘtre reliĂ©s uniquement Ă  une activitĂ© fluviale et ont Ă©tĂ© dĂ©posĂ©s dans des Ă©tendues d'eaux calmes liĂ©es Ă  une Ă©lĂ©vation concomitante du niveau des nappes phrĂ©atiques durant des Ă©pisodes biostasiques du stage isotopique 3. De grands mammifĂšres ont alors pu trouver de l'eau et de l'herbe dans la vallĂ©e et ĂȘtre chassĂ©s par les hommes du PalĂ©olithique moyen. La nappe phrĂ©atique s'est maintenue Ă  un niveau Ă©levĂ© aprĂšs 30 ka B.P et les chenaux Ă  graviers des affluents locaux sont restĂ©s actifs durant la pĂ©riode 30-20 ka B.P. AprĂšs cette date, l’instabilitĂ© s’est accrue ; dans cette partie de la vallĂ©e, la vĂ©gĂ©tation s'est rarĂ©fiĂ©e, les sols ont Ă©tĂ© remaniĂ©s, Ă©difiant des cĂŽnes locaux oĂč s'observent aussi des influences Ă©oliennes (Unité 3, stage isotopique 2). Enfin, une forte incision linĂ©aire s’est produite Ă  l’HolocĂšne infĂ©rieur, dissĂ©quant l'accumulation soltanienne

    The Partnership Co-Design Lab: Co-constructing a Patient Advisor Programme to increase adherence to rehabilitation after upper extremity replantation

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    A five-phase Patient Advisor Programme created by the Partnership Co-Design Lab led to higher rates of adherence to rehabilitation interventions for patients followed at the main rehabilitation centre compared to patients transferred to other, more remote, rehabilitation facilities

    MYH7 p.(Arg1712Gln) is pathogenic founder variant causing hypertrophic cardiomyopathy with overall relatively delayed onset

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    Introduction: The MYH7 c.5135G &gt; A p.(Arg1712Gln) variant has been identified in several patients worldwide and is classified as pathogenic in the ClinVar database. We aimed to delineate its associated phenotype and evaluate a potential founder effect.Methods: We retrospectively collected clinical and genetic data of 22 probands and 74 family members from an international cohort.Results: In total, 53 individuals carried the MYH7 p.(Arg1712Gln) variant, of whom 38 (72%) were diagnosed with hypertrophic cardiomyopathy (HCM). Mean age at HCM diagnosis was 48.8 years (standard deviation: 18.1; range: 8–74). The clinical presentation ranged from asymptomatic HCM to arrhythmias (atrial fibrillation and malignant ventricular arrhythmias). Aborted sudden cardiac death (SCD) leading to the diagnosis of HCM occurred in one proband at the age of 68 years, and a family history of SCD was reported by 39% (5/13) probands. Neither heart failure deaths nor heart transplants were reported. Women had a generally later-onset disease, with 14% of female carriers diagnosed with HCM at age 50 years compared with 54% of male carriers. In both sexes, the disease was fully penetrant by age 75 years. Haplotypes were reconstructed for 35 patients and showed a founder effect in a subset of patients.Conclusion: MYH7 p.(Arg1712Gln) is a pathogenic founder variant with a consistent HCM phenotype that may present with delayed penetrance. This suggested that clinical follow-up should be pursued after the seventh decade in healthy carriers and that longer intervals between screening may be justified in healthy women &lt; 30 years.</p
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