Selection bias: neighbourhood controls and controls selected from those presenting to a Health Unit in a case control study of efficacy of BCG revaccination.

BACKGROUND: In most case control studies the hardest decision is the choice of the control group, as in the ideal control group the proportion exposed is the same as in the population that produced the cases. METHODS: A comparison of two control groups in a case control study of the efficacy of BCG revaccination. One group was selected from subjects presenting to the heath unit the case attended for routine prevention and care; the second group was selected from the neighbourhood of cases. All Health Units from which controls were selected offered BCG revaccination. Efficacy estimated in a randomized control trial of BCG revaccination was used to establish that the neighbourhood control group was the one that gave unbiased results. RESULTS: The proportion of controls with scars indicating BCG revaccination was higher among the control group selected from Health Unit attenders than among neighbourhood controls. This excess was not removed after control for social variables and history of exposure to tuberculosis, and appears to have resulted from the fact that people attending the Health Unit were more likely to have been revaccinated than neighbourhood controls, although we can not exclude an effect of other unmeasured variables. CONCLUSION: In this study, controls selected from people presenting to a Health Unit overrepresented exposure to BCG revaccination. Had the results from the HU attenders control group been accepted this would have resulted in overestimation of vaccine efficacy. When the exposure of interest is offered in a health facility, selection of controls from attenders at the facility may result in over representation of exposure in controls and selection bias

Satellites and large doping- and temperature-dependence of electronic properties in hole-doped BaFe2As2

Over the last years, superconductivity has been discovered in several families of iron-based compounds. Despite intense research, even basic electronic properties of these materials, such as Fermi surfaces, effective electron masses, or orbital characters are still subject to debate. Here, we address an issue that has not been considered before, namely the consequences of dynamical screening of the Coulomb interactions among Fe-d electrons. We demonstrate its importance not only for correlation satellites seen in photoemission spectroscopy, but also for the low-energy electronic structure. From our analysis of the normal phase of BaFe2As2 emerges the picture of a strongly correlated compound with strongly doping- and temperature-dependent properties. In the hole overdoped regime, an incoherent metal is found, while Fermi-liquid behavior is recovered in the undoped compound. At optimal doping, the self-energy exhibits an unusual square-root energy dependence which leads to strong band renormalizations near the Fermi level

Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England

Purebred dog health is thought to be compromised by an increasing occurence of inherited diseases but inadequate prevalence data on common disorders have hampered efforts to prioritise health reforms. Analysis of primary veterinary practice clinical data has been proposed for reliable estimation of disorder prevalence in dogs. Electronic patient record (EPR) data were collected on 148,741 dogs attending 93 clinics across central and south-eastern England. Analysis in detail of a random sample of EPRs relating to 3,884 dogs from 89 clinics identified the most frequently recorded disorders as otitis externa (prevalence 10.2%, 95% CI: 9.1-11.3), periodontal disease (9.3%, 95% CI: 8.3-10.3) and anal sac impaction (7.1%, 95% CI: 6.1-8.1). Using syndromic classification, the most prevalent body location affected was the head-and-neck (32.8%, 95% CI: 30.7-34.9), the most prevalent organ system affected was the integument (36.3%, 95% CI: 33.9-38.6) and the most prevalent pathophysiologic process diagnosed was inflammation (32.1%, 95% CI: 29.8-34.3). Among the twenty most-frequently recorded disorders, purebred dogs had a significantly higher prevalence compared with crossbreds for three: otitis externa (P = 0.001), obesity (P = 0.006) and skin mass lesion (P = 0.033), and popular breeds differed significantly from each other in their prevalence for five: periodontal disease (P = 0.002), overgrown nails (P = 0.004), degenerative joint disease (P = 0.005), obesity (P = 0.001) and lipoma (P = 0.003). These results fill a crucial data gap in disorder prevalence information and assist with disorder prioritisation. The results suggest that, for maximal impact, breeding reforms should target commonly-diagnosed complex disorders that are amenable to genetic improvement and should place special focus on at-risk breeds. Future studies evaluating disorder severity and duration will augment the usefulness of the disorder prevalence information reported herein

Profits and Fractal Properties: Notes on Marx, Countertendencies and Simulation Models

© 2017 Informa UK Limited, trading as Taylor & Francis Group. There are new reasons for revisiting Marx’s elaboration on the rate of profit because contemporary debates provide findings from the MEGA Project, long-term data on the rate of profit, and tools for dealing with complexity and non-equilibrium systems. This article proposes that the interplay between the tendency and the countertendencies of the rate of profit to fall can be translated into a simple system of equations, one based on each chapter of Section Three of Capital—as if Marx sought to mathematically formalise his insights. This article reviews previous debates, presents data and runs a simulation model, showing that the rate of profit behaves as fractals.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil), grant (BEX 0840/14-9

A network model for the complex behavior of the rate of profit: Exploring a simulation model with overlapping technological revolutions

This article proposes a network model to replicate the behaviour of the profit rate in the long run. Specifically, it accounts for the results of an empirical investigation of the profit rate in the US, which show that it has fractal properties and its complexity changes over time. The starting point of the model is Marx’s insights on the interplay between the tendency of the rate to fall and its countertendencies. It combines these insights with the persistent generation of new commodities – inventions – and a specific set of new branches of production that triggers technological revolutions. A simulation running this network model successfully replicates historical features of the system.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil), grant (BEX 0840/14-9

Comparative phylogenetic methods and the cultural evolution of medicinal plant use

Human life depends on plant biodiversity and the ways in which plants are used are culturally determined. Whilst anthropologists have used phylogenetic comparative methods (PCMs) to gain an increasingly sophisticated understanding of the evolution of political, religious, social, and material culture, plant use has been almost entirely neglected. Medicinal plants are of special interest because of their role in maintaining people’s health across the world. PCMs in particular, and cultural evolutionary theory in general, provide a framework in which to study the diversity of medicinal plant applications cross-culturally, and to infer changes in plant use through time. These methods can be applied to single medicinal plants as well as the entire set of plants used by a culture for medicine, and they account for the non-independence of data when testing for floristic, cultural or other drivers of plant use. With cultural, biological, and linguistic diversity under threat, gaining a deeper and broader understanding of the variation of medicinal plant use through time and space is pressing

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Conservation priorities of useful plants from different techniques of collection and analysis of ethnobotanical data

This study analyzes three methods of data analysis to verify which one would be more appropriate to get information aiming the conservation, selecting the use value (VU) inventory in situ and conservation property index (IPC). It was developed in in Northeast Brazil, via interviewed householders (46 informants). The VU was calculated considering only the effective use of plants; the inventory in situ was made through the frequency of species occurrence in homes; and the IPC combining ethnobotanical and phytossociological data. It was observed a similar cast of the indicated species by VU and inventory in situ, being different from the IPC cast. As this study sought to analyze the best technique for species identification which were needing conservationist actions, and obtained different results among the chosen methods. It has been suggested the use of methods that unite in their analysis both ethnobotanical and ecological aspects, like in the plants list from the priority index of conservation, which demonstrated to be more efficient to identify rare species in the local vegetation. The VU and the inventory in situ are more efficient to identify the most known and used species in the communities, however without analyzing these plants in the local vegetation

Neurocysticercosis in Paraiba, northeast Brazil: an endemic area?

Neurocysticercosis is the central nervous system infestation by Cysticercus cellulosae, the larval form of Taenia solium. It is related to poor hygiene habits and sanitation; although Northeast is poorest Region of Brazil, it has been always stated as a non-endemic area. After the installation of computed tomography (CT) service, the incidence of neurocysticercosis began to raise in neurology services in Campina Grande PB, a city where people from the interior Paraíba can find specialized medical facilities. We analyse 5,883 CT record of the TomoHPI Computed Tomography Service from August 1993 to December 1995, observing 1.02% suggestive neurocysticercosis cases and classified them according to sex and age, precedence and socioeconomic condition. Distribution of cases according to age is homogeneous until the age of 50 (mean: 28.36 years old). Men and women are equally affected. Urban areas inhabitants represented 83.33%. Residents of Campina Grande represented 48.33% and 48.34% were residents of cities around Campina Grande (until 50 Km around) and other cities of Paraíba State. Fifty-eight patients were dependent to public health care system. We conclude that neurocysticercosis seems to be endemic in Paraíba State, demanding a more detailed study to determine its incidence/prevalence.Neurocisticercose é a infestação do sistema nervoso central pelo Cysticercus cellulosae, a forma larval da Taenia solium. É relacionada a hábitos higiênicos e sanitários precários; embora o Nordeste seja a Região mais pobre do Brasil, foi sempre considerada área não-endêmica para neurocisticercose. Depois da instalação de um serviço de tomografia computadorizada (TC), a incidência da neurocisticercose começou a crescer nos serviços de neurologia em Campina Grande PB, cidade para onde confluem pessoas de todo o interior paraibano à procura de serviços médicos especializados. Analisamos 5.883 TC realizadas no Serviço TomoHPI de Radioimagem do Hospital Pedro I de agosto de 1993 até dezembro de 1995 e 1,02% foram diagnosticadas como sugestivas de neurocisticercose e classificadas de acordo com idade e sexo, procedência e condições sócio-econômicas. A distribuição dos casos de acordo com a idade é homogênea até os 50 anos de idade (média: 28,36 anos). Homens e mulheres são afetados igualmente. Procedentes de áreas urbanas representam 83.33%. Residentes em Campina Grande representam 48.33% do total; 48,34% residem em cidades ao redor de Campina Grande (até 50 Km de distância) ou em outras cidades da Paraíba. Cincoenta e oito pacientes são dependentes do Sistema Único de Saúde. Concluimos que a neurocisticercose parece ser endêmica em nosso Estado, sendo necessários estudos mais detalhados para que tal assertiva possa ser confirmada