The iterated auxiliary particle filter

We present an offline, iterated particle filter to facilitate statistical inference in general state space hidden Markov models. Given a model and a sequence of observations, the associated marginal likelihood L is central to likelihood-based inference for unknown statistical parameters. We define a class of "twisted" models: each member is specified by a sequence of positive functions psi and has an associated psi-auxiliary particle filter that provides unbiased estimates of L. We identify a sequence psi* that is optimal in the sense that the psi*-auxiliary particle filter's estimate of L has zero variance. In practical applications, psi* is unknown so the psi*-auxiliary particle filter cannot straightforwardly be implemented. We use an iterative scheme to approximate psi*, and demonstrate empirically that the resulting iterated auxiliary particle filter significantly outperforms the bootstrap particle filter in challenging settings. Applications include parameter estimation using a particle Markov chain Monte Carlo algorithm

Evaluating genetic traceability methods for captive bred marine fish and their applications in fisheries management and wildlife forensics

Growing demands for marine fish products is leading to increased pressure on already depleted wild populations and a rise in the aquaculture production. Consequently, more captive bred fish are released into the wild through accidental escape or deliberate restocking, stock enhancement and sea ranching programs. The increased mixing of captive bred fish with wild conspecifics may affect the ecological and/or genetic integrity of wild fish populations. From a fisheries management perspective unambiguous identification tools for captive bred fish will be highly valuable to manage risks. Additionally there is great potential to use these tools in wildlife forensics (i.e. tracing back escapees to their origin and determining mislabelling of seafood products). Using SNP data from captive bred and wild populations of Atlantic cod (Gadus morhua L.) and sole (Solea solea L.), we explored the efficiency of population and parentage assignment techniques for the identification and tracing of captive bred fish. Simulated and empirical data were used to correct for stochastic genetic effects. Overall, parentage assignment performed well when a large effective population size characterizes the broodstock and escapees originate from early generations of captive breeding. Consequently, parentage assignments are particularly useful from a fisheries management perspective to monitor the effects of deliberate releases of captive bred fish on wild populations. Population assignment proved to be more efficient after several generations of captive breeding, which makes it a useful method in forensic applications for well-established aquaculture species. We suggest the implementation of a case by case strategy when choosing the best method

Estudio experimental de la consolidación de fracturas en la desnutrición proteica: utilización de calcitonina en ratas desnutrida

Los autores estudian el papel de la Calcitonina en la consolidación de fracturas experimentales producidas en la tibia izquierda de 65 ratas albinas adultas. Los animales se dividían en cuatro grupos. El grupo A compuestos por 20 animales con una dieta normal y recibiendo 5 U/Kg de peso de Calcitonina diaria por vía intramuscular; el grupo B por 20 animales alimentados con una dieta no proteica y recibiendo Calcitonina diariamente y a la misma dosis que en el grupo A; el grupo C es el grupo de control, compuesto por 15 animales alimentados con dieta normal y sin medicación; por último el grupo D, también de control, compuesto por 10 animales alimentados con dieta no proteica y sin medicación. A los componentes de la dieta no proteica se añadió fécula de maíz (MaizenaR ) que fue el origen calórico. Las fracturas fueron protocolizadas de forma que fueron similares en lo que respecta a su loralización en diálisis así como su forma y trazo; se escogieron las tibias para nuestro estudio debido a la facilidad con que dichas fracturas podían realizarse a mano. En todos los grupos los 2 animales fueron sacrificados a las 3 semanas de provocada la fractura. Durante este intervalo, los animales fueron alimentados con la dieta asignada a cada uno de los grupos, con o sin la administración de inyecciones intramusculares de calcitonina. Los animales de cada grupo se situaron en la misma caja, con agua «ad libitum» y sin restricción de movimientos. El hueso fue estudiado macroscópicamente, radiológicamente y microscópicamente mediante técnicas histoló- gicas e histomorfométricas con piezas teñidas con hematoxilina-eosina. Todas las preparaciones fueron estudiadas por microscopía óptica. Los resultados llevaron a los autores a la conclusión de que la curación de la fractura en hueso largo curaba más rápido y el callo era cualitativamente mejor en animales tratados con Calcitonina, cuando eran comparados con los grupos de control.The authors studied the role of Calcitonin in the consolidation of experimental fractures produced in the left tibiae of 65 adult Albino rats. The animals were divided in four groups: Group A: 20 animals on a normal diet, receiving Calcitonin 5 U/kg body weight, intramuscular daily; Group B: 20 animals fed on a no-protein diet and receiving Calcitonin in the same dosage as Group A and daily; Group C: Control group- 15 animals on normal diet and without any medication; and Group D: Control group- 10 animals on no-protein diet and without any medication. To the components of the non-protein diet was added maize starch (MaizenaR ) which was the calory-source. The fractures were standardized to meet the conditions of the experiment such as fractures should be similar concerning both their localization in the diaphyses and their shape and trace; tibiae were chosen for our study due to the readiness with which handmade fractures can be produced. In all groups the animals were killed three weeks after the fractures had been carried out. During this interval, animals were fed on the diet assigned to their respective groups, with or without administration of intramuscular injections of Calcitonin. Animals in each group were placed in the same cage, with water ad libitum and no restriction to movements. The bone healing was studied macroscopically, radiologically, and microscopically through histologic and histomorphometric techniques with the samples stained with hematoxilin-eosin. AD slices were studied by optic microscopy. The results led the authors to the conclusion that long bone fracture healing progressed faster and the calli were qualitatively better in animals treated with Calcitonin, when compared to the controls

Factitious disease: a challenge to several specialities

O transtorno factício caracteriza-se por produção de sintomas por parte do pacientede forma intencional, com o intuito de assumir o papel de paciente. É uma doença de graves implicações clínicas e que gera elevados gastos para o sistema de saúde público. O caso da paciente DLK, ilustrado nesse relato, exemplifica bem esse transtorno. A paciente iniciou suas queixas clínicas com alucinações visuais e um quadro delirante. Com o tempo surgiram queixas de dores abdominais, retenção urinária, fraqueza muscular e um quadro psicótico de difícil resolução. A paciente passou por diversas internações e especialistas e foi submetida a diversos exames e uma laparoscopia, todos de resultados frustros. Apresentou melhora progressiva e importante dos sintomas após o estabelecimento de um vínculo positivo com a equipe e redução das medicações utilizadas. A detecção precoce dessa doença é fundamental, reduzindo a morbidade do transtorno e a prática de medidas iatrogênicas que esses pacientes demandam.In factitious disease there is an intentional production of symptoms by the patient, with the intent of being sick in front of others. It is a disease with serious clinical implications and these patients represent a enormous waste of money to public health. The case of DLK exemplifies it. The complaints of the patient began with delusions and visual hallucinations. She developed abdominal pains, urinary retention, weakness and psychotic symptoms of difficult management. She had gone to several hospitals, submitted to many exams and a laparoscopy, all with frustrating results. There was a progressive and important improvement by the establishment of a positive relation with the patient and reduction of her medications. Early crecognition of this disease is fundamental, diminishing the morbidity of this disease and the practice of iatrogenic measures demanded by these patients

Algunes reflexions entorn de la conceptualització de la infància i adolescència en risc social a l'Estat espanyol

L'article realitza una aproximació a les interpretacions del concepte de risc social de la infancia per part de diversos autors d'àmbit estatal, tenint també en compte els marcs legals català i espanyol. Pretén aclarir quins són els criteris valoratius emprats, tant des de l'àmbit acadèmic com del professional, per interpretar les categoritzacions de la infància i l'adolescència en processos de dificultat i precarietat social. Des d'aquesta perspectiva, s'hi analitza l'estreta relació entre factors de risc, desemparament i marginació. S'hi rebutgen les interpretacions que responsabilitzen el propi menor de la desadaptació, i s'hi defensa la hipótesi de la necessitat d'una intervenció socioeducativa que treballi per una disminució dels factors de risc en el propi medi, mantenint el seu protagonisme en aquest procés.This article is an approach to the different acceptances of the concept social risk as well as the terms neglect and maladjustment, based on the reflections made by different authors and both statal and autonomous legal framework. It intends to clarify which are the criteria of values used in academic and professional ambits in order to understand the categoriesfound in the fields of childhood and adolescence in difficult and precarious conditions. The strong relation between risk factors, neglect and margination has been analysed from this point of view. In the same way the interpretations that hold the minor himself responsible for his maladjustment are rejected and the author defends the necessity of a socio-educational intervention, which reduces the risk factors in the child's environment, and the need of paying close attention to the child's main role in this process.El artículo realiza una aproximación a las interpretaciones del concepto de riesgo social de la infancia por parte de diversos autores de ámbito estatal, teniendo también en cuenta los marcos legales catalán y español. Pretende aclarar cuáles son los criterios valorativos utilizados, tanto desde el ámbito academico como profesional, para interpretar las categorizaciones de la infancia en procesos de dificultad y precariedad. Desde esta perspectiva, se analiza la estrecha relación entre factores de riesgo, desamparamiento y marginación. Se rechazan las interpretaciones que responsabilizan al propio menor de la desadaptación y se defiende la hipótesis de la necesidad de una intervención socioeducativa que trabaje para una disminución de los factores de riesgo en el propio medio, manteniendo su protagonismo en este proceso

How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers

Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program

Novel PCR-based assay for rapid identification of Red Fluorescent Proteins in GloFish and GloFish x wildtype zebrafish (Danio rerio) hybrids

none4noTwenty-five zebrafish presenting three different colour variants were collected and analysed by molecular markers in order to define their species and to verify if the unusual colouration presented by two morphotypes was due to genetic engineering or were natural colour variants obtained by selective breeding or spontaneous mutations. The three morphotypes collected were (a) an unusual reddish-pink (suspected red GloFish®), 15 specimens confiscated by the operative ecological core of police officers; (b) the black/blue striped colouration typical of wildtype Danio rerio (five specimens) and (c) an hybrid morphotype with an atypical flashing red pigmentation of skeletal muscle and a blue-black striped pigmentation of skin (five specimens obtained by crossing suspected GM danios with wildtype line) obtained by crossing wild type danios with fish confiscated by police. Despite the three different colourations presented, all analysed samples were unequivocally Danio rerio, excluding the possibility of belonging to different species or natural variants, which should carry different skin colours. Except the five wild-type danios, all other samples analysed should belong to an engineered variant and thus forbidden by EU GMO legislation. Here we designed a new highly reliable and affordable PCR-based assay able to identify the presence of red fluorescent proteins not only in the 15 parental GM samples but also in the five F1 hybrids created ad hoc. The cross-breeding experiment clearly demonstrated that the exogenous construct made by red fluorescent protein under a fast-muscle promoter was inherited by F1. For this reason in our opinion also cross-hybrids obtained by GM danios and wildtype zebrafish should be included in the list of organisms regulated by GMO legislation. Finally, the obtained results suggest that the PCR-based assay here implemented could represent a cost-effective test to rapidly identify suspected GM fish, which carry RFP/dsRED isoformsopenC. OFELIO; A. CARIANI; M. TRENTINI; I. GUARNIEROC. OFELIO; A. CARIANI; M. TRENTINI; I. GUARNIER