Beyond good intentions: lessons on equipment donation from an African hospital.

OBJECTIVE: In 2000, a referral hospital in the Gambia accepted a donation of oxygen concentrators to help maintain oxygen supplies. The concentrators broke down and were put into storage. A case study was done to find the reasons for the problem and to draw lessons to help improve both oxygen supplies and the success of future equipment donations. METHODS: A technical assessment of the concentrators was carried out by a biomedical engineer with relevant expertise. Semi-structured interviews were undertaken with key informants, and content analysis and inductive approaches were applied to construct the history of the episode and the reasons for the failure. FINDINGS: Interviews confirmed the importance of technical problems with the equipment. They also revealed that the donation process was flawed, and that the hospital did not have the expertise to assess or maintain the equipment. Technical assessment showed that all units had the wrong voltage and frequency, leading to overheating and breakdown. Subsequently a hospital donations committee was established to oversee the donations process. On-site biomedical engineering expertise was arranged with a nongovernmental organization (NGO) partner. CONCLUSION: Appropriate donations of medical equipment, including oxygen concentrators, can be of benefit to hospitals in resource-poor settings, but recipients and donors need to actively manage donations to ensure that the donations are beneficial. Success requires planning, technical expertise and local participation. Partners with relevant skills and resources may also be needed. In 2002, WHO produced guidelines for medical equipment donations, which address problems that might be encountered. These guidelines should be publicized and used

Discordant transmission of bacteria and viruses from mothers to babies at birth

BACKGROUND: The earliest microbial colonizers of the human gut can have life-long consequences for their hosts. Precisely how the neonatal gut bacterial microbiome and virome are initially populated is not well understood. To better understand how the maternal gut microbiome influences acquisition of the infant gut microbiome, we studied the early life bacterial microbiomes and viromes of 28 infant twin pairs and their mothers. RESULTS: Infant bacterial and viral communities more closely resemble those of their related co-twin than unrelated infants. We found that 63% of an infant\u27s bacterial microbiome can be traced to their mother\u27s gut microbiota. In contrast, only 15% of their viral communities are acquired from their mother. Delivery route did not determine how much of the bacterial microbiome or virome was shared from mother to infant. However, bacteria-bacteriophage interactions were altered by delivery route. CONCLUSIONS: The maternal gut microbiome significantly influences infant gut microbiome acquisition. Vertical transmission of the bacterial microbiome is substantially higher compared to vertical transmission of the virome. However, the degree of similarity between the maternal and infant gut bacterial microbiome and virome did not vary by delivery route. The greater similarity of the bacterial microbiome and virome between twin pairs than unrelated twins may reflect a shared environmental exposure. Thus, differences of the inter-generation transmissibility at birth between the major kingdoms of microbes indicate that the foundation of these microbial communities are shaped by different rules. Video Abstract

Characterization of Dextromethorphan And Dextrorphan Uptake by a Putative Glutamic Acid Carrier and Passive Diffusion Across Brain Microvessel Endothelium

Read More: http://informahealthcare.com/doi/abs/10.3109/10717549309022764The mechanisms of uptake and transcellular passage of dextromethorphan (DM) and its major metabolite dextrorphan (DX) across the endothelial component of the blood–brain barrier have been investigated with primary cultures of bovine brain microvessel endothelial cells (BMECs). The uptake of [14C]DM and [14C]DX by BMECs was observed to be temperature-sensitive and saturable, with approximate Km's of 0.12 and 0.29 mM and Vmax's of 9.2 and 11.0 pmol/mg/min, respectively. The BMEC uptake of [14C] DM was inhibited half-maximally by approximately 0.57 mM L-glutamic acid, 0.71 mM N-methyl-d-asparatate (NMDA), and 0.99 mM DL-threo-β-hydroxyaspartic acid. The BMEC uptake of [14C]DX was inhibited half-maximally by approximately 0.48 mM L-glutamic acid, 1.50 mM NMDA, and 0.69 mM DL-threo-β-hydroxyaspartic acid. Conversely, the bidirectional passage of DM and DX across confluent BMEC monolayers occurred at a faster rate but was neither saturable nor inhibited by high concentrations of glutamic acid, NMDA, or unlabeled DM or DX. These results suggest that DM and DX are capable of interacting with a low-capacity glutamic acid-type carrier mechanism on the apical surface of BMECs. However, the net transfer of these agents across BMEC monolayers appeared to be more rapid and passive in nature

Newton methods for nonsmooth convex minimization: connections among U-Lagrangian, Riemannian Newton and SQP methods

International audienceThis paper studies Newton-type methods for minimization of partly smooth convex functions. Sequential Newton methods are provided using local parameterizations obtained from U-Lagrangian theory and from Riemannian geometry. The Hessian based on the U-Lagrangian depends on the selection of a dual parameter g; by revealing the connection to Riemannian geometry, a natural choice of g emerges for which the two Newton directions become identical. This choice of g is also shown to be related to the least-squares multiplier estimate from a sequential quadratic programming (SQP) approach, and with this multiplier, SQP gives the same search direction as the Newton methods

Projection methods in conic optimization

There exist efficient algorithms to project a point onto the intersection of a convex cone and an affine subspace. Those conic projections are in turn the work-horse of a range of algorithms in conic optimization, having a variety of applications in science, finance and engineering. This chapter reviews some of these algorithms, emphasizing the so-called regularization algorithms for linear conic optimization, and applications in polynomial optimization. This is a presentation of the material of several recent research articles; we aim here at clarifying the ideas, presenting them in a general framework, and pointing out important techniques

La Perte des Savoirs et Pratiques Endogenes: Risques pour l’Environnement Naturel du Territoire Blouf en Basse Casamance (Senelgal)

Au Sénégal, l’environnement naturel en général subit de nombreuses agressions (sécheresse, pollution, destruction des habitats et surexploitation) qui sont autant de causes de perte de la biodiversité. Pourtant, en dépit de ces multiples agressions, il existe encore des endroits en Basse Casamance où l’on peut trouver une biodiversité remarquable. Entre autres milieux, figurent les sites naturels sacrés qui jouissent d’une protection fondée sur des règles traditionnelles, lesquelles reposent sur des savoirs locaux transmis à travers les générations. Les savoirs locaux identifiés ainsi que de nombreuses pratiques locales contribuent à la conservation des ressources naturelles, malgré les pressions multiples. Ces ressources ont des valeurs culturelles, spirituelles et matérielles remarquables. Aujourd’hui, la prise de conscience par la communauté scientifique de l’intérêt de ces savoirs endogènes pour la conservation, pose le problème de leur maintien. Le présent article fait le point sur cette question sur la base d’une recherche bibliographique et d’enquêtes essentiellement qualitatif menées à l’aide de questionnaires et des focus groupes qui ont permis de faire un état des lieux sur les savoirs et pratiques qui subsistent et qui sont bénéfiques pour la conservation. Les interviews sont réalisées auprès de 111 ménages de la contrée Blouf.   In Senegal, the natural environment in general suffers from numerous aggressions (drought, pollution, destruction of habitats and overexploitation) which are as many causes of loss of biodiversity. Yet, despite these multiple attacks on the environment, there are still places in Lower Casamance where we can find remarkable biodiversity. Among other environments are the sacred natural sites that enjoy protection based on traditional rules, which rely on local knowledge passed down through the generations. The knowledge identified in the biophysical and sociocultural environments as well as many local practices contribute to the conservation of marine and coastal natural resources, despite the multiple pressures. These resources have remarkable cultural, spiritual and material values. Today, with the scientific community's awareness of the interest of this endogenous knowledge for conservation, its maintenance is necessary for the well-being of local communities whose survival depends directly on resources. This article reviews this question on the basis of a bibliographic search and essentially qualitative surveys using questionnaires and focus groups that allowed us to take stock of the knowledge and practices remain and are beneficial for conservation. Interviews are conducted with 111 households in the Blouf region

La Perte de Savoirs et de Pratiques Endogenes: Risques pour l’Envitonnement Naturel du Territoire Blouf en Basse Casamance (Senegal)

Au Sénégal, l’environnement naturel en général subit de nombreuses agressions (sécheresse, pollution, destruction des habitats et surexploitation) qui sont autant de causes de perte de la biodiversité. Pourtant, en dépit de ces multiples agressions, il existe encore des endroits en Basse Casamance où l’on peut trouver une biodiversité remarquable. Entre autres milieux, figurent les sites naturels sacrés qui jouissent d’une protection fondée sur des règles traditionnelles, lesquelles reposent sur des savoirs locaux transmis à travers les générations. Les savoirs locaux identifiés ainsi que de nombreuses pratiques locales contribuent à la conservation des ressources naturelles, malgré les pressions multiples. Ces ressources ont des valeurs culturelles, spirituelles et matérielles remarquables. Aujourd’hui, la prise de conscience par la communauté scientifique de l’intérêt de ces savoirs endogènes pour la conservation, pose le problème de leur maintien. Le présent article fait le point sur cette question à partir d’une recherche bibliographique et d’enquêtes essentiellement qualitatif menées à l’aide d’un guide d’entretien et des focus groupes qui ont permis de faire un état des lieux sur les savoirs et pratiques qui subsistent et qui sont bénéfiques pour la conservation.   In Senegal, the natural environment, in general, suffers from numerous aggressions (drought, pollution, destruction of habitats, and overexploitation) which are as many causes of loss of biodiversity. Yet, despite these multiple attacks on the environment, there are still places in Lower Casamance where we can find remarkable biodiversity. Among other environments are the sacred natural sites that enjoy protection based on traditional rules, which rely on local knowledge passed down through the generations. The knowledge identified in the biophysical and sociocultural environments as well as many local practices contribute to the conservation of marine and coastal natural resources, despite the multiple pressures. These resources have remarkable cultural, spiritual, and material values. Today, with the scientific community's awareness of the interest of this endogenous knowledge for conservation, its maintenance is necessary for the well-being of local communities whose survival depends directly on resources. This article reviews this question on the basis of a bibliographic search and essentially qualitative surveys using interview guides and focus groups that allowed us to take stock of the knowledge and practices that remain and are beneficial for conservation

La Perte des Savoirs et Pratiques Endogenes: Risques pour l’Environnement Naturel du Territoire Blouf en Basse Casamance (Senelgal)

Au Sénégal, l’environnement naturel en général subit de nombreuses agressions (sécheresse, pollution, destruction des habitats et surexploitation) qui sont autant de causes de perte de la biodiversité. Pourtant, en dépit de ces multiples agressions, il existe encore des endroits en Basse Casamance où l’on peut trouver une biodiversité remarquable. Entre autres milieux, figurent les sites naturels sacrés qui jouissent d’une protection fondée sur des règles traditionnelles, lesquelles reposent sur des savoirs locaux transmis à travers les générations. Les savoirs locaux identifiés ainsi que de nombreuses pratiques locales contribuent à la conservation des ressources naturelles, malgré les pressions multiples. Ces ressources ont des valeurs culturelles, spirituelles et matérielles remarquables. Aujourd’hui, la prise de conscience par la communauté scientifique de l’intérêt de ces savoirs endogènes pour la conservation, pose le problème de leur maintien. Le présent article fait le point sur cette question sur la base d’une recherche bibliographique et d’enquêtes essentiellement qualitatif menées à l’aide de questionnaires et des focus groupes qui ont permis de faire un état des lieux sur les savoirs et pratiques qui subsistent et qui sont bénéfiques pour la conservation. Les interviews sont réalisées auprès de 111 ménages de la contrée Blouf.   In Senegal, the natural environment in general suffers from numerous aggressions (drought, pollution, destruction of habitats and overexploitation) which are as many causes of loss of biodiversity. Yet, despite these multiple attacks on the environment, there are still places in Lower Casamance where we can find remarkable biodiversity. Among other environments are the sacred natural sites that enjoy protection based on traditional rules, which rely on local knowledge passed down through the generations. The knowledge identified in the biophysical and sociocultural environments as well as many local practices contribute to the conservation of marine and coastal natural resources, despite the multiple pressures. These resources have remarkable cultural, spiritual and material values. Today, with the scientific community's awareness of the interest of this endogenous knowledge for conservation, its maintenance is necessary for the well-being of local communities whose survival depends directly on resources. This article reviews this question on the basis of a bibliographic search and essentially qualitative surveys using questionnaires and focus groups that allowed us to take stock of the knowledge and practices remain and are beneficial for conservation. Interviews are conducted with 111 households in the Blouf region

Large nonsaturating magnetoresistance, weak anti-localization and non-trivial topological states in SrAl2_2Si2_2

We explore the electronic and topological properties of single crystal SrAl$_2$Si$_2$ using magnetotransport experiments in conjunction with first-principle calculations. We find that the temperature-dependent resistivity shows a pronounced peak near 50 K. We observe several remarkable features at low temperatures, such as large non-saturating magnetoresistance, Shubnikov-de Haas oscillations and cusp-like magneto-conductivity. The maximum value of magnetoresistance turns out to be 459\% at 2 K and 12 T. The analysis of the cusp-like feature in magneto-conductivity indicates a clear signature of weak anti-localization. Our Hall resistivity measurements confirm the presence of two types of charge carriers in SrAl$_2$Si$_2$, with low carrier density