Benchmark calculations for elastic fermion-dimer scattering

We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine the scattering length and effective range parameter to high precision. For the lattice calculation we use the finite-volume method of L\"uscher. We take into account topological finite-volume corrections to the dimer binding energy which depend on the momentum of the dimer. After subtracting these effects, we find from the lattice calculation kappa a_fd = 1.174(9) and kappa r_fd = -0.029(13). These results agree well with the continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained from the STM equation. We discuss applications to cold atomic Fermi gases, deuteron-neutron scattering in the spin-quartet channel, and lattice calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure

Control of Bone Resorption by Semaphorin 4D Is Dependent on Ovarian Function

Osteoporosis is one of the most common bone pathologies, which are characterized by a decrease in bone mass. It is well established that bone mass, which results from a balanced bone formation and bone resorption, is regulated by many hormonal, environmental and genetic factors. Here we report that the immune semaphorin 4D (Sema4D) is a novel factor controlling bone resorption. Sema4D-deficient primary osteoclasts showed impaired spreading, adhesion, migration and resorption due to altered ß3 integrin sub-unit downstream signaling. In apparent accordance with these in vitro results, Sema4D deletion in sexually mature female mice led to a high bone mass phenotype due to defective bone resorption by osteoclasts. Mutant males, however, displayed normal bone mass and the female osteopetrotic phenotype was only detected at the onset of sexual maturity, indicating that, in vivo, this intrinsic osteoclast defect might be overcome in these mice. Using bone marrow cross transplantation, we confirmed that Sema4D controls bone resorption through an indirect mechanism. In addition, we show that Sema4D −/− mice were less fertile than their WT littermates. A decrease in Gnrh1 hypothalamic expression and a reduced number of ovarian follicles can explain this attenuated fertility. Interestingly, ovariectomy abrogated the bone resorption phenotype in Sema4D −/− mice, providing the evidence that the observed high bone mass phenotype is strictly dependent on ovarian function. Altogether, this study reveals that, in vivo, Sema4D is an indirect regulator of bone resorption, which acts via its effect on reproductive function

Snail1 controls bone mass by regulating Runx2 and VDR expression during osteoblast differentiation

Bone undergoes continuous remodelling throughout adult life, and the equilibrium between bone formation by osteoblasts and bone resorption by osteoclasts defines the final bone mass. Here we show that Snail1 regulates this balance by controlling osteoblast differentiation. Snail1 is necessary for the early steps of osteoblast development, and it must be downregulated for their final differentiation. At the molecular level, Snail1 controls bone mass by repressing the transcription of both the osteoblast differentiation factor Runx2 and the vitamin D receptor (VDR) genes in osteoblasts. Sustained activation of Snail1 in transgenic mice provokes deficient osteoblast differentiation, which, together with the loss of vitamin D signalling in the bone, also impairs osteoclastogenesis. Indeed, the mineralisation of the bone matrix is severely affected, leading to hypocalcemia-independent osteomalacia. Our data show that the impact of Snail1 activity on the osteoblast population regulates the course of bone cells differentiation and ensures normal bone remodelling

Automatic news recommendations via aggregated profiling

Today, people have only limited, valuable leisure time at their hands which they want to fill in as good as possible according to their own interests, whereas broadcasters want to produce and distribute news items as fast and targeted as possible. These (developing) news stories can be characterised as dynamic, chained, and distributed events in addition to which it is important to aggregate, link, enrich, recommend, and distribute these news event items as targeted as possible to the individual, interested user. In this paper, we show how personalised recommendation and distribution of news events, described using an RDF/OWL representation of the NewsML-G2 standard, can be enabled by automatically categorising and enriching news events metadata via smart indexing and linked open datasets available on the web of data. The recommendations-based on a global, aggregated profile, which also takes into account the (dis)likings of peer friends-are finally fed to the user via a personalised RSS feed. As such, the ultimate goal is to provide an open, user-friendly recommendation platform that harnesses the end-user with a tool to access useful news event information that goes beyond basic information retrieval. At the same time, we provide the (inter)national community with standardised mechanisms to describe/distribute news event and profile information

Hydrothermal saline promoted grafting of periodic mesoporous organic sulfonic acid silicas for sustainable FAME production

Hydrothermal saline promoted grafting of sulfonic acid groups onto SBA-15 and periodic mesoporous organic silica analogues affords solid acid catalysts with high acid site loadings (>2.5 mmol g-1 H+), ordered mesoporosity and tunable hydrophobicity. The resulting catalysts show excellent activity for fatty acid esterification and tripalmitin transesterification to methyl palmitate, with framework phenyl groups promoting fatty acid methyl esters production. (Chemical Equation Presented

Impact of macroporosity on catalytic upgrading of fast pyrolysis bio-oil by esterification over silica sulfonic acids

Fast pyrolysis bio-oils possess unfavourable physicochemical properties and poor stability, due in large part to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom and energy efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates. Macropore (200 nm) incorporation enhances the activity of mesoporous SBA-15 architectures (post-functionalised by hydrothermal saline promoted grafting) for the esterification of linear carboxylic acids, with the magnitude of turnover frequency (TOF) enhancement increasing with chain length from 5 % (C3) to 110 % (C12). Macroporous-mesoporous PrSO3H/SBA-15 also offers a two-fold TOF enhancement over its mesoporous analogue for the esterification of a real thermal fast pyrolysis bio-oil derived from woodchips. The total acid number was reduced by 57 %, with GCxGC-ToFMS evidencing ester and ether formation accompanying loss of acid, phenolic, aldehyde and ketone components

Cryptococcosis in the Democratic Republic of Congo from 1953 to 2021: A systematic review and meta-analysis

Contexte La cryptococcose est l’une des infections opportunistes les plus courantes et les plus incriminées dans la morbidité et mortalité associées à l'infection par le VIH. Dans sa forme neuro-méningée, la cryptococcose est responsable de 15% de décès au cours du VIH dans le monde. Elle est principalement causée par le complexe d’espèces Cryptococcus neoformans/ C. gattii. En République démocratique du Congo (RDC), l'infection par le VIH reste un problème menaçant, ce, dans un environnement de santé publique fragile et précaire. Objectifs La présente revue systématique examine les aspects cliniques et biologiques de la cryptococcose en RDC, et en estime le fardeau dans la population séropositive immunodéprimée à haut risque d’infections opportunistes. Méthodes En utilisant les directives PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis), nous avons recherché dans les bases de données en ligne et dans la littérature grise des publications disponibles sur la cryptococcose et Cryptococcus spp. en RDC. Les études ont été considérées sans aucune restriction linguistique et une méta-analyse a été réalisée pour estimer les données regroupées et les intervalles de confiance correspondants (IC) à 95%. Le fardeau de la cryptococcose neuro-méningée (CNM) a ensuite été estimé sur la base de (1) la prévalence moyenne de la CNM dans la population à VIH et (2) du nombre d’adultes vivant avec le VIH en RDC tel qu’estimé par ONUSIDA en 2020, tout en ne considérant que la population à haut risque. Bien que les personnes vivant avec le VIH (PVVIH) considérées dans la présente étude soient celles qui connaissent leur statut VIH, les critères de haut risque appliqués ici sont : le taux de CD4 < 200 cellules/µL, l'absence du traitement antirétroviral (ARV), l'échec du traitement ARV et la perte de vue dans le suivi. Résultats Au total, 30 articles de recherche ont été inclus dans la présente revue. Ils ont globalement inclus 1.018 patients atteints de cryptococcose, dont 80,8% avec une forme neuro-méningée et majoritairement immunodéprimés par le VIH/SIDA (97,6%). La prévalence moyenne de la CNM a été estimée à 9,63% (IC 95% : [5,99 - 14,07]), infectant principalement des patients de sexe féminin (51,7%), mariés (52%) et d'un âge médian de 35 (28 - 41) ans. Le taux médian de CD4 des patients était de 161 (98-499) cellules/µL et le procédé diagnostique le plus utilisé était la coloration directe à l'encre de Chine (264 sur 357). Plus d'un patient sur deux (52,7%) sont décédés parmi les patients traités. Le traitement de la cryptococcose a consisté principalement en une monothérapie au fluconazole (80,6 %). Par ailleurs, nous estimons qu'environ 9.265 (IC 95 % : 5.763 – 13.537) PVVIH ont été atteintes de CNM en 2020, parmi lesquelles 4.883 (IC 95 % : 3.037 – 7.134) seraient décédées la même année. Dans l’ensemble, en RDC, 74 isolats de Cryptococcus spp. ont été isolés et caractérisés, dont 82,4% de Cryptococcus neoformans, exclusivement de sérotype A et de types moléculaires VNI et VNII ; et 17,6% de Cryptococcus gattii, exclusivement de sérotype B et de type moléculaire VGI. Il est par ailleurs est noté que la plupart de ces types moléculaires ont également été isolés dans les pays voisins de la RDC. Conclusions Au fil des années, en RDC, la cryptococcose est restée fréquente avec un taux de mortalité inacceptablement élevé. En 2020, le nombre de PVVIH infectées et décédées de suite de la cryptococcose démontre son lourd fardeau chez les PVVIH congolaises. Recommandations Il est donc important d'améliorer la lutte contre le VIH-Sida en implémentant, effectivement, la stratégie test and treat et en encourageant le dépistage volontaire, notamment par les populations-clés. La mise en place d'un programme national de lutte contre les mycoses peut soutenir ces effortsCryptococcose chez les personnes vivant avec le VIH à Kinshasa : contribution à l'étude épidémiologique et moléculaire3. Good health and well-bein

Octyl co-grafted PrSO3H/SBA-15:tunable hydrophobic solid acid catalysts for acetic acid esterification

Propylsulfonic acid (PrSO3H) derivatised solid acid catalysts have been prepared by post modification of mesoporous SBA-15 silica with mercaptopropyltrimethoxysilane (MPTMS), with the impact of co-derivatisation with octyltrimethoxysilane (OTMS) groups to impart hydrophobicity to the catalyst investigated. Turn over frequencies (TOF) for acetic acid esterification with methanol increase with PrSO3H surface coverage across both families suggesting a cooperative effect of adjacent acid sites at high acid site densities. Esterification activity is further promoted upon co-functionalisation with hydrophobic octyl chains, with inverse gas chromatography (iGC) measurements indicating increased activity correlates with decreased surface polarity or increased hydrophobicity