Global network structure of dominance hierarchy of ant workers

Dominance hierarchy among animals is widespread in various species and believed to serve to regulate resource allocation within an animal group. Unlike small groups, however, detection and quantification of linear hierarchy in large groups of animals are a difficult task. Here, we analyse aggression-based dominance hierarchies formed by worker ants in Diacamma sp. as large directed networks. We show that the observed dominance networks are perfect or approximate directed acyclic graphs, which are consistent with perfect linear hierarchy. The observed networks are also sparse and random but significantly different from networks generated through thinning of the perfect linear tournament (i.e., all individuals are linearly ranked and dominance relationship exists between every pair of individuals). These results pertain to global structure of the networks, which contrasts with the previous studies inspecting frequencies of different types of triads. In addition, the distribution of the out-degree (i.e., number of workers that the focal worker attacks), not in-degree (i.e., number of workers that attack the focal worker), of each observed network is right-skewed. Those having excessively large out-degrees are located near the top, but not the top, of the hierarchy. We also discuss evolutionary implications of the discovered properties of dominance networks.Comment: 5 figures, 2 tables, 4 supplementary figures, 2 supplementary table

Gamergate controls dopamine levels of workers in <i>Diacamma</i> sp.

Introdução: O climatério representa uma fase de mudança e de transição no ciclo de vida feminino, durante o qual as mulheres experimentam alterações físicas e psicológicas decorrentes do hipoestrogenismo e envelhecimento. O Médico de Família é habitualmente o primeiro profissional de saúde a quem a mulher recorre para esclarecer as suas dúvidas e solicitar o alívio da sintomatologia climatérica, ocupando uma posição privilegiada para promover a capacitação e empowerment das utentes. Métodos: Promoveu-se um estudo observacional transversal, aplicando um questionário de auto-preenchimento a 92 mulheres, com idades compreendidas entre os 40 e os 60 anos, que frequentam os Centros de Saúde Norton de Matos e S. Martinho do Bispo (USF Mondego), de forma a avaliar a abordagem da menopausa nos Cuidados de Saúde Primários. A recolha dos dados decorreu de abril a julho de 2014. O tratamento estatístico foi efetuado através da plataforma estatística IBM SPSS v21.0. Resultados: Mais de metade das mulheres (55,4%) referiu ter conversado com o Médico de Família sobre a menopausa e todos os assuntos relacionados, todavia 19,6% ainda manifestavam dúvidas. O médico foi considerado a principal fonte de informação para 50% das inquiridas. A maioria das mulheres (77,2%) descreveu a presença de sintomas climatéricos, sendo os mais frequentes as dores ósseas (73,2%) e a ansiedade (67,6%). 39,1% das inquiridas indicaram a interferência do climatério na sua vida diária, sendo a vida familiar (69,4%) e a sexual (58,3%) as mais afetadas. Verificou-se uma associação significativa entre a presença de sintomas e a interferência do climatério na vida diária e na qualidade de vida da mulher. As mulheres sintomáticas (OR=12,983 com IC95% [2,808;60,033]) e as que referiram a interferência do climatério no dia a dia (OR=5,965 com IC95% [2,364;15,048]) apresentaram uma probabilidade aumentada de recorrer a consultas de Medicina Geral e Familiar. As infeções urinárias de repetição (91,7%) foram as queixas que mais motivaram a ida ao Médico de Família. Das mulheres sintomáticas, 45,1% referiram ter cuidados adicionais ou fazer algum tratamento. A terapêutica hormonal revelou-se a mais eficaz no alívio das queixas, tendo como prescritor mais frequente o Ginecologista (58,3%). Conclusão: O Médico de Família assume um papel crucial na capacitação e acompanhamento da mulher climatérica. Constatou-se que ainda permanecem dúvidas que necessitam de ser esclarecidas e que são necessárias normas que uniformizem a abordagem da menopausa na prática clínica.Introduction: The climacteric represents a time of change and transition in the female life cycle, during which women experience physical and psychological changes resulting from hypoestrogenism and aging. The general practitioner is usually the first health professional to whom a woman appeals to clarify her doubts and request relief from climacteric symptoms, occupying a privileged position to promote capacity building and empowerment of patients. Methods: It was promoted a cross-sectional observational study, applying a self-completion questionnaire to 92 women, aged between 40 and 60 years, who attend the health centers of Norton de Matos and S. Martinho do Bispo (USF Mondego), in order to evaluate the approach of menopause in Primary Health Care. Data collection took place from April to July 2014. The statistical analysis was performed by the statistical platform IBM SPSS v21.0. Results: More than half of women (55.4%) said they had talked to the general practitioner about menopause and all the related subjects, however 19.6% still had doubts. The doctor was considered the main source of information for 50% of the surveyed women. Most women (77.2%) described the presence of menopausal symptoms, the most common being bone pain (73.2%) and anxiety (67.6%). 39.1% of the surveyed indicated the interference of the climacteric in their everyday life, being the family life (69.4%) and the sexual life (58.3%) the most affected. There was a significant association between the presence of symptoms of menopause and the interference of the climacteric in daily life and quality of life. Symptomatic women (OR = 12.983 with 95% CI [2.808, 60.033]) and those who mentioned the interference of the climacteric in daily life (OR = 5.965 95% CI [2.364, 15.048]) had an increased likelihood of appealing to a general practitioner. Recurrent urinary tract infections (91.7%) were complaints that most commonly lead going to the general practitioner. Of symptomatic women, 45.1% said having additional care or getting some treatment. Hormone therapy proved more effective in relieving complaints, having the gynecologist as the most frequent prescriber (58.3%). Conclusion: The general practitioner plays a key role in the capacity building and monitoring of the climacteric woman. It was found that there are still questions that need to be clarified and that standards are necessary to standardize the approach of menopause in clinical practice

Temporal Progression Patterns of Brain Atrophy in Corticobasal Syndrome and Progressive Supranuclear Palsy Revealed by Subtype and Stage Inference (SuStaIn)

Differentiating corticobasal degeneration presenting with corticobasal syndrome (CBD-CBS) from progressive supranuclear palsy with Richardson's syndrome (PSP-RS), particularly in early stages, is often challenging because the neurodegenerative conditions closely overlap in terms of clinical presentation and pathology. Although volumetry using brain magnetic resonance imaging (MRI) has been studied in patients with CBS and PSP-RS, studies assessing the progression of brain atrophy are limited. Therefore, we aimed to reveal the difference in the temporal progression patterns of brain atrophy between patients with CBS and those with PSP-RS purely based on cross-sectional data using Subtype and Stage Inference (SuStaIn)—a novel, unsupervised machine learning technique that integrates clustering and disease progression modeling. We applied SuStaIn to the cross-sectional regional brain volumes of 25 patients with CBS, 39 patients with typical PSP-RS, and 50 healthy controls to estimate the two disease subtypes and trajectories of CBS and PSP-RS, which have distinct atrophy patterns. The progression model and classification accuracy of CBS and PSP-RS were compared with those of previous studies to evaluate the performance of SuStaIn. SuStaIn identified distinct temporal progression patterns of brain atrophy for CBS and PSP-RS, which were largely consistent with previous evidence, with high reproducibility (99.7%) under cross-validation. We classified these diseases with high accuracy (0.875) and sensitivity (0.680 and 1.000, respectively) based on cross-sectional structural brain MRI data; the accuracy was higher than that reported in previous studies. Moreover, SuStaIn stage correctly reflected disease severity without the label of disease stage, such as disease duration. Furthermore, SuStaIn also showed the genialized performance of differentiation and reflection for CBS and PSP-RS. Thus, SuStaIn has potential for improving our understanding of disease mechanisms, accurately stratifying patients, and providing prognoses for patients with CBS and PSP-RS

Microscopic Surface Structure of Liquid Alkali Metals

We report an x-ray scattering study of the microscopic structure of the surface of a liquid alkali metal. The bulk liquid structure factor of the eutectic K67Na33 alloy is characteristic of an ideal mixture, and so shares the properties of an elemental liquid alkali metal. Analysis of off-specular diffuse scattering and specular x-ray reflectivity shows that the surface roughness of the K-Na alloy follows simple capillary wave behavior with a surface structure factor indicative of surface induced layering. Comparison of thelow-angle tail of the K67Na33 surface structure factor with the one measured for liquid Ga and In previously suggests that layering is less pronounced in alkali metals. Controlled exposure of the liquid to H2 and O2 gas does not affect the surface structure, indicating that oxide and hydride are not stable at the liquid surface under these experimental conditions.Comment: 12 pages, 3 figures, published in Phys. Rev.

Phase-field-crystal models for condensed matter dynamics on atomic length and diffusive time scales: an overview

Here, we review the basic concepts and applications of the phase-field-crystal (PFC) method, which is one of the latest simulation methodologies in materials science for problems, where atomic- and microscales are tightly coupled. The PFC method operates on atomic length and diffusive time scales, and thus constitutes a computationally efficient alternative to molecular simulation methods. Its intense development in materials science started fairly recently following the work by Elder et al. [Phys. Rev. Lett. 88 (2002), p. 245701]. Since these initial studies, dynamical density functional theory and thermodynamic concepts have been linked to the PFC approach to serve as further theoretical fundaments for the latter. In this review, we summarize these methodological development steps as well as the most important applications of the PFC method with a special focus on the interaction of development steps taken in hard and soft matter physics, respectively. Doing so, we hope to present today's state of the art in PFC modelling as well as the potential, which might still arise from this method in physics and materials science in the nearby future.Comment: 95 pages, 48 figure

Microscopic dynamics in liquid metals: the experimental point of view

The experimental results relevant for the understanding of the microscopic dynamics in liquid metals are reviewed, with special regards to the ones achieved in the last two decades. Inelastic Neutron Scattering played a major role since the development of neutron facilities in the sixties. The last ten years, however, saw the development of third generation radiation sources, which opened the possibility of performing Inelastic Scattering with X rays, thus disclosing previously unaccessible energy-momentum regions. The purely coherent response of X rays, moreover, combined with the mixed coherent/incoherent response typical of neutron scattering, provides enormous potentialities to disentangle aspects related to the collectivity of motion from the single particle dynamics. If the last twenty years saw major experimental developments, on the theoretical side fresh ideas came up to the side of the most traditional and established theories. Beside the raw experimental results, therefore, we review models and theoretical approaches for the description of microscopic dynamics over different length-scales, from the hydrodynamic region down to the single particle regime, walking the perilous and sometimes uncharted path of the generalized hydrodynamics extension. Approaches peculiar of conductive systems, based on the ionic plasma theory, are also considered, as well as kinetic and mode coupling theory applied to hard sphere systems, which turn out to mimic with remarkable detail the atomic dynamics of liquid metals. Finally, cutting edges issues and open problems, such as the ultimate origin of the anomalous acoustic dispersion or the relevance of transport properties of a conductive systems in ruling the ionic dynamic structure factor are discussed.Comment: 53 pages, 41 figures, to appear in "The Review of Modern Physics". Tentatively scheduled for July issu

Body distribution of 11C-methionine and 18FDG in rat measured by microPET

Compounds 18F-fluorodeoxyglucose (18FDG) and 11C-methionine (11C-MET) are radiodiagnostics frequently used in clinical Positron Emission Tomography (PET) as well in preclinical studies of various pathologies. The present study was focused on the comparison of biodistribution of both radiotracers in intact Wistar rats. The animals were scanned by microPET twice. The first scanning was done after 11C-MET administration, the second scan followed 5–7 days later using 18FDG. The radiotracers were injected into the tail vein of animals in isoflurane anesthesia. After a redistribution period, whole body scans were obtained using eXplore Vista SrT GE tomograph. Accumulation of the drugs in tissues was expressed in relative values (% ID/g) in selected regions of interest. As arbitrary reference tissue for drug accumulation, the sternoclavicular area was used. 18C-MET was found remarkably cumulating especially in the liver, spleen and distal part of the gastrointestinal tract. The compound was accumulated in the liver 6.9±0.92 (mean±SEM) times more intensively than in the reference tissue. The respective value for spleen and cecum/colon was 5.62±0.81 and 3.56±0.14 times. Accumulation of 11C-MET in other body parts including the brain and heart was very low and was apparently equal to the arbitrary tissue (0.13±0.01% ID/g). In the same animals 18FDG (biontFDG) was remarkably cumulated especially in Harderian glands compared to arbitrary tissue background (11.02±1.00 times), heart (7.52±1.70 times), brain (6.14±0.37 times), and colon (5.68±0.31 times). 18FDG accumulation in the liver, spleen and other organs was apparently not different from that found in the background (0.14±0.02% ID/g). The data obtained may serve as reference values in further microPET preclinical studies with 11C-MET and 18FDG under the given conditions

A Histone-Like Protein of Mycobacteria Possesses Ferritin Superfamily Protein-Like Activity and Protects against DNA Damage by Fenton Reaction

Iron is an essential metal for living organisms but its level must be strictly controlled in cells, because ferrous ion induces toxicity by generating highly active reactive oxygen, hydroxyl radicals, through the Fenton reaction. In addition, ferric ion shows low solubility under physiological conditions. To overcome these obstacles living organisms possess Ferritin superfamily proteins that are distributed in all three domains of life: bacteria, archaea, and eukaryotes. These proteins minimize hydroxyl radical formation by ferroxidase activity that converts Fe2+ into Fe3+ and sequesters iron by storing it as a mineral inside a protein cage. In this study, we discovered that mycobacterial DNA-binding protein 1 (MDP1), a histone-like protein, has similar activity to ferritin superfamily proteins. MDP1 prevented the Fenton reaction and protects DNA by the ferroxidase activity. The Km values of the ferroxidase activity by MDP1 of Mycobacterium bovis bacillus Calmette-Guérin (BCG-3007c), Mycobacterium tuberculosis (Rv2986c), and Mycobacterium leprae (ML1683; ML-LBP) were 0.292, 0.252, and 0.129 mM, respectively. Furthermore, one MDP1 molecule directly captured 81.4±19.1 iron atoms, suggesting the role of this protein in iron storage. This study describes for the first time a ferroxidase-iron storage protein outside of the ferritin superfamily proteins and the protective role of this bacterial protein from DNA damage