199 research outputs found

    Direct Observation of the Superfluid Phase Transition in Ultracold Fermi Gases

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    Water freezes into ice, atomic spins spontaneously align in a magnet, liquid helium becomes superfluid: Phase transitions are dramatic phenomena. However, despite the drastic change in the system's behaviour, observing the transition can sometimes be subtle. The hallmark of Bose-Einstein condensation (BEC) and superfluidity in trapped, weakly interacting Bose gases is the sudden appearance of a dense central core inside a thermal cloud. In strongly interacting gases, such as the recently observed fermionic superfluids, this clear separation between the superfluid and the normal parts of the cloud is no longer given. Condensates of fermion pairs could be detected only using magnetic field sweeps into the weakly interacting regime. The quantitative description of these sweeps presents a major theoretical challenge. Here we demonstrate that the superfluid phase transition can be directly observed by sudden changes in the shape of the clouds, in complete analogy to the case of weakly interacting Bose gases. By preparing unequal mixtures of the two spin components involved in the pairing, we greatly enhance the contrast between the superfluid core and the normal component. Furthermore, the non-interacting wings of excess atoms serve as a direct and reliable thermometer. Even in the normal state, strong interactions significantly deform the density profile of the majority spin component. We show that it is these interactions which drive the normal-to-superfluid transition at the critical population imbalance of 70(5)%.Comment: 16 pages (incl. Supplemental Material), 5 figure

    Rugoscopy in human identification: a study in a sample of twins

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    Palatal rugae patterns can be useful for forensic identification purposes. However, some doubts persist in concerning the pattern singularity in twins. The purpose of this study was to assess palatal rugae pattern singularity in a sample of twins. To do this, the palatal rugae patterns of 19 pairs of monozygotic twins and 47 pairs of dizygotic twins were studied. Our results showed that in monozygotic twins, no statistical significant differences were found, either in the form or number of palatal rugae. However, in dizygotic twins, differences were found in the number or shape of all palatal rugae (except for the shape of the first two right ones), suggesting that the palatal rugae pattern can be useful for identification purposes of dizygotic, but not of monozygotic, twins.Generation XXI was funded by Programa Operacional de Saúde (Regional Department of Ministry of Health). It has support from the Portuguese Foundation for Science and Technology (FCT) and from the Calouste Gulbenkian Foundation.An individual grant to Braga S (SFRH/BD/120500/2016) by the Portuguese Foundation for Science and Technology (FCT) is gratefully acknowledged.This work was financed by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE 2020 – Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT – Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/MEC-MCI/29777/2017/POCI-01-0145-FEDER-029777

    Orofacial Injuries in Children and Adolescents (2009-2013): A 5-Year Study In Porto, Portugal

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    The aim of this study was to verify the prevalence of acts of aggression to the head, face and neck towards victims of Physical Violence against Children and Adolescents (PVCA) who were examined at the National Institute of Legal Medicine and Forensic Sciences Delegation North (INMLCF-DN) in Porto, Portugal. A study was carried out on 2,148 complaints of physical aggression against children and adolescents (0 to less than 18 years old) occurred between 2009 and 2013 and which were retrieved from information about violence held on INMLCF-DN data files. Continuous variables were described and the association between them was verified by Chi-square or Fischer’s Exact tests with 5% significance level. Within the 5-year timespan, 1,380 cases were identified with clinical relation with physical aggression. Most subjects evaluated were male adolescents and the most affected body region was the face, to which 747 injuries (24.7%) were recorded, with statistically significant association between sex and region (head and face). Victims in 15-17-year-old age group are more susceptible to violence than those in the 0-14-year-old age range. Dentists routinely examine the face, neck and skull, which make them the most appropriate health professionals to identify cases of aggression early.The authors thank the INMLCF-DN (Instituto Nacional de Medicina Legal e Ciências Forenses - Delegação do Norte, Portugal) for technical support and CAPES(Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil) for scholarship

    Treatment of developmental dyslexia: A review

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    Remarkably few research articles on the treatment of developmental dyslexia were published during the last 25 years. Some treatment research arose from the temporal processing theory, some from the phonological deficit hypothesis and some more from the balance model of learning to read and dyslexia. Within the framework of that model, this article reviews the aetiology of dyslexia sub-types, the neuropsychological rationale for treatment, the treatment techniques and the outcomes of treatment research. The possible mechanisms underlying the effects of treatment are discussed. © 2005 Informa UK Ltd All rights reserved

    Forensic age estimation using the eruption of the second permanent mandibular molar: determining age over 14 years-old

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    Little is known about the role of the second molar eruption in forensic age estimation; however, in countries where the legal age is 14-years-old, it can provide important information. This study aims to analyse whether the eruption stages of the second mandibular molar can be used for forensic age estimation purposes. The eruption stage of the second left mandibular molar was assessed and correlation between age and stage of eruption was evaluated using Spearman rank order correlation. A Chi-square test was used to assess the correlation between age equal or superior to 14 and stage C or D attainment. The level of significance was defined as p<0.05. Stage C and D attainment and age 14 were significantly related in both sexes (p<0.001). Still, stage 3 was attained by 37% and 44.4% of the males and females younger than 14 years, respectively; stage 4 was attained by 14.8% and 25.6% of the males and females younger than 14 years, respectively. Second molar emergence, particularly stage D, can be used as a dental age indicator. When stage D is attained, particularly in males, there is strong suggestion of age over 14 years. However, other markers should also be used

    Chronology of mineralization of the permanent mandibular second molar teeth and forensic age estimation

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    Forensic age estimation frequently relies upon the chronology of mineralization of the third molar teeth. However, even when present, third molar teeth cannot always be used for estimating age in people who are classified as minors. Seconds molars develop earlier and in a more predictable way, and therefore are often more reliable for age estimation in this age group. This study aims to contribute to forensic age estimation using an age threshold of 14-years, studying the stages of development of permanent mandibular second molar teeth mineralization. 367 orthopantograms of a Portuguese population group, aged between 3 and 19 years, were studied. The stages of mineralization of mandibular permanent second molar teeth were studied following the classification stages proposed by Demirjian et al. Stage descriptive analysis was performed, and associations between age and stage were studied.A logistic regression to determine age over 14 years, using maturation stages and sex as a predictive variables, was made. A second sample was used for testing the model. The significance level was set at 5%. The model correctly classified 92.0% of cases overall. The equation was tested in the second sample, and the results showed that there were no statistical significant differences between the binary real age (i.e. age < 14 and age ≥ 14 years) and the estimated age (p = 0.109). The developed model is useful for age estimation using 14-years as a threshold. However, stage maturation analyses showed that stage F, in males, and stages G and H, in both sexes, lead to an estimated age with significant statistical differences from chronological age

    Regulation of immunity during visceral Leishmania infection

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    Unicellular eukaryotes of the genus Leishmania are collectively responsible for a heterogeneous group of diseases known as leishmaniasis. The visceral form of leishmaniasis, caused by L. donovani or L. infantum, is a devastating condition, claiming 20,000 to 40,000 lives annually, with particular incidence in some of the poorest regions of the world. Immunity to Leishmania depends on the development of protective type I immune responses capable of activating infected phagocytes to kill intracellular amastigotes. However, despite the induction of protective responses, disease progresses due to a multitude of factors that impede an optimal response. These include the action of suppressive cytokines, exhaustion of specific T cells, loss of lymphoid tissue architecture and a defective humoral response. We will review how these responses are orchestrated during the course of infection, including both early and chronic stages, focusing on the spleen and the liver, which are the main target organs of visceral Leishmania in the host. A comprehensive understanding of the immune events that occur during visceral Leishmania infection is crucial for the implementation of immunotherapeutic approaches that complement the current anti-Leishmania chemotherapy and the development of effective vaccines to prevent disease.The research leading to these results has received funding from the European Community’s Seventh Framework Programme under grant agreement No.602773 (Project KINDRED). VR is supported by a post-doctoral fellowship granted by the KINDReD consortium. RS thanks the Foundation for Science and Technology (FCT) for an Investigator Grant (IF/00021/2014). This work was supported by grants to JE from ANR (LEISH-APO, France), Partenariat Hubert Curien (PHC) (program Volubilis, MA/11/262). JE acknowledges the support of the Canada Research Chair Program

    Merozoite release from Plasmodium falciparum-infected erythrocytes involves the transfer of DiIC16 from infected cell membrane to Maurer’s clefts

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    Merozoite release from infected erythrocytes is a complex process, which is still not fully understood. Such process was characterised at ultra-structural level in this work by labelling erythrocyte membrane with a fluorescent lipid probe and subsequent photo-conversion into an electron-dense precipitate. A lipophilic DiIC16 probe was inserted into the infected erythrocyte surface and the transport of this phospholipid analogue through the erythrocyte membrane was followed up during 48 h of the asexual erythrocyte cycle. The lipid probe was transferred from infected erythrocyte membranes to Maurer’s clefts during merozoite release, thereby indicating that these membranes remained inside host cells after parasite release. Fluorescent structures were never observed inside infected erythrocytes preceding merozoite exit and merozoites released from infected erythrocyte were not fluorescent. However, specific precipitated material was localised bordering the parasitophorous vacuole membrane and tubovesicular membranes when labelled non-infected erythrocytes were invaded by merozoites. It was revealed that lipids were interchangeable from one membrane to another, passing from infected erythrocyte membrane to Maurer’s clefts inside the erythrocyte ghost, even after merozoite release. Maurer’s clefts became photo-converted following merozoite release, suggesting that these structures were in close contact with infected erythrocyte membrane during merozoite exit and possibly played some role in malarial parasite exit from the host cell
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