Specialized odorant receptors in social insects that detect cuticular hydrocarbon cues and candidate pheromones.

Eusocial insects use cuticular hydrocarbons as components of pheromones that mediate social behaviours, such as caste and nestmate recognition, and regulation of reproduction. In ants such as Harpegnathos saltator, the queen produces a pheromone which suppresses the development of workers' ovaries and if she is removed, workers can transition to a reproductive state known as gamergate. Here we functionally characterize a subfamily of odorant receptors (Ors) with a nine-exon gene structure that have undergone a massive expansion in ants and other eusocial insects. We deorphanize 22 representative members and find they can detect cuticular hydrocarbons from different ant castes, with one (HsOr263) that responds strongly to gamergate extract and a candidate queen pheromone component. After systematic testing with a diverse panel of hydrocarbons, we find that most Harpegnathos saltator Ors are narrowly tuned, suggesting that several receptors must contribute to detection and discrimination of different cuticular hydrocarbons important in mediating eusocial behaviour.Cuticular hydrocarbons (CHC) mediate the interactions between individuals in eusocial insects, but the sensory receptors for CHCs are unclear. Here the authors show that in ants such as H. saltator, the 9-exon subfamily of odorant receptors (HsOrs) responds to CHCs, and ectopic expression of HsOrs in Drosophila neurons imparts responsiveness to CHCs

Forestry in Brazil and environmental impacts: a holistic vision

This study was aimed at raising and discussing issues about forestry and its influence on natural environments through a literature review based on an exploratory descriptive method. The monograph was used as a procedural method because it allowed us to use various literature sources, such as the Doctrine, constitutions and other legal documents related to those principles within the scope of environmental law. The man is turning native forests into an artificial environment and is also homogenizing productive processes, including agriculture and livestock. The fact that the environment loses its characteristic of genetic heterogeneity or complexity means that the ecosystems are being simplified. If this occurs, there will be an impact on biodiversity. Consequently, "genetic erosion" will be produced, reducing the number of flora and fauna species.O presente trabalho objetivou levantar e discutir questões acerca da silvicultura e sua influencia no ambiente natural, tomando como base uma revisão bibliográfica ligada a temática. A metodologia deste trabalho foi fundamentada em revisão bibliográfica, através do método descritivo exploratório. Como método de procedimento, foi utilizado o monográfico, por possibilitar o procedimento da pesquisa a partir de diversas fontes bibliográficas, como a doutrina, os textos constitucionais e demais documentos legais referentes aos princípios no âmbito do direito ambiental. O homem está artificializando o ambiente florestal nativo e homogeneizando os processos de produção que envolve, inclusive, a agricultura e a pecuária. Quando o ambiente perde sua característica de heterogeneidade ou de complexidade gênica, significa que se está procedendo a uma simplificação desses ecossistemas. Se tais fatos estão ocorrendo, ter-se-á, então, um reflexo sobre a biodiversidade, cujo resultado final será uma “erosão genética”, que nada mais é do que a redução do número de espécies da flora e da fauna.Asociación de Universidades Grupo Montevide

Dark Matter Subhalos in the Ursa Minor Dwarf Galaxy

Through numerical simulations, we study the dissolution timescale of the Ursa Minor cold stellar clump, due to the combination of phase-mixing and gravitational encounters with compact dark substructures in the halo of Ursa Minor. We compare two scenarios; one where the dark halo is made up by a smooth mass distribution of light particles and one where the halo contains 10% of its mass in the form of substructures (subhalos). In a smooth halo, the stellar clump survives for a Hubble time provided that the dark matter halo has a big core. In contrast, when the point-mass dark substructures are added, the clump survives barely for \sim 1.5 Gyr. These results suggest a strong test to the \Lambda-cold dark matter scenario at dwarf galaxy scale.Comment: accepted for publication in Ap

OCUPANDO ESPAÇOS: GESTOS, PROCESSOS DE SUBJETIVAÇÃO E COLETIVIDADES ENTRE JOVENS UNIVERSITÁRIOS

Este estudo analisa o modo como os estudantes da PUC-MG ocupam o espaço da universidade e das imediações, procurando compreender melhor os processos de subjetivação e os modos de vida coletivos aí encetados, no sentido de identificar possibilidades de afirmação do presente (e de uma dimensão política deste), através das corporeidades, e dos espaços públicos. Utilizou-se pesquisa bibliográfica centrada em teóricos da filosofia da diferença e da filosofia das imagens, e trabalho de campo baseado na metodologia de pesquisa-intervenção. Realizou-se registro dos itinerários e das permanências dos estudantes nos espaços da universidade, através da produção de imagens (fotos e filmagens) e de intervenções nas ocupações do campus (mapas para serem inscritos e o grupo Espaço Pensamento Ação). Conclui-se que, num espaço que se apresenta geralmente marcado, os ocupantes querem se inscrever, compondo efêmeros coletivos. Percebese, assim, a necessidade de esses corpos se inscreverem e criarem, de alguma maneira, seus próprios espaços.Palavras-Chave: Processos de subjetivação. Coletividades. Imagens. Gestos

Diagnostic route is associated with care satisfaction independently of tumour stage: Evidence from linked English Cancer Patient Experience Survey and cancer registration data.

BACKGROUND: Whether diagnostic route (e.g. emergency presentation) is associated with cancer care experience independently of tumour stage is unknown. METHODS: We analysed data on 18 590 patients with breast, prostate, colon, lung, and rectal cancers who responded to the 2014 English Cancer Patient Experience Survey, linked to cancer registration data on diagnostic route and tumour stage at diagnosis. We estimated odds ratios (OR) of reporting a negative experience of overall cancer care by tumour stage and diagnostic route (crude and adjusted for patient characteristic and cancer site variables) and examined their interactions with cancer site. RESULTS: After adjustment, the likelihood of reporting a negative experience was highest for emergency presenters and lowest for screening-detected patients with breast, colon, and rectal cancers (OR versus two-week-wait 1.51, 95% confidence interval [CI] 1.24-1.83; 0.88, 95% CI 0.75-1.03, respectively). Patients with the most advanced stage were more likely to report a negative experience (OR stage IV versus I 1.37, 95% CI 1.15-1.62) with little confounding between stage and route, and no evidence for cancer-stage or cancer-route interactions. CONCLUSIONS: Though the extent of disease is strongly associated with ratings of overall cancer care, diagnostic route (particularly emergency presentation or screening detection) exerts important independent effects.This work is supported by Macmillan Cancer Support grant 5995414 for which GAA and GL are joint principal investigators. GL is supported by a Cancer Research UK Advanced Clinician Scientist Fellowship Award (C18081/A18180)

An XMM-Newton search for X-ray sources in the Fornax dwarf galaxy

We report the results of a deep archive XMM-Newton observation of the Fornax spheroidal galaxy that we analyzed with the aim of fully characterizing the X-ray source population (in most of the cases likely to be background active galactic nuclei) detected towards the target. A cross correlation with the available databases allowed us to find a source that may be associated with a variable star belonging to the galaxy. We also searched for X-ray sources in the vicinity of the Fornax globular clusters GC 3 and GC 4 and found two sources probably associated with the respective clusters. The deep X-ray observation was also suitable for the search of the intermediate-mass black hole (of mass $\simeq 10^{4}$ M$_{\odot}$) expected to be hosted in the center of the galaxy. In the case of Fornax, this search is extremely difficult since the galaxy centroid of gravity is poorly constrained because of the large asymmetry observed in the optical surface brightness. Since we cannot firmly establish the existence of an X-ray counterpart of the putative black hole, we put constraints only on the accretion parameters. In particular, we found that the corresponding upper limit on the accretion efficiency, with respect to the Eddington luminosity, is as low as a few $10^{-5}$.Comment: In press on Astronomy and Astrophysics. 12 Pages, colour figures on the on-line version of the pape

Nerve excitability changes related to muscle weakness in chronic progressive external ophthalmoplegia

Objective: To explore potential spreading to peripheral nerves of the mitochondrial dysfunction in chronic progressive external ophthalmoplegia (CPEO) by assessing axonal excitability. Methods: CPEO patients (n = 13) with large size deletion of mitochondrial DNA and matching healthy controls (n = 22) were included in a case-control study. Muscle strength was quantified using MRC sum-score and used to define two groups of patients: CPEO-weak and CPEO-normal (normal strength). Nerve excitability properties of median motor axons were assessed with the TROND protocol and changes interpreted with the aid of a model. Results: Alterations of nerve excitability strongly correlated with scores of muscle strength. CPEO-weak displayed abnormal nerve excitability compared to CPEO-normal and healthy controls, with increased superexcitability and responses to hyperpolarizing current. Modeling indicated that the CPEO-weak recordings were best explained by an increase in the ‘Barrett-Barrett’ conductance across the myelin sheath. Conclusion: CPEO patients with skeletal weakness presented sub-clinical nerve excitability changes, which were not consistent with axonal membrane depolarization, but suggested Schwann cell involvement. Significance: This study provides new insights into the spreading of large size deletion of mitochondrial DNA to Schwann cells in CPEO patients

High-Redshift Star-Forming Galaxies: Angular Momentum and Baryon Fraction, Turbulent Pressure Effects and the Origin of Turbulence

The structure of a sample of high-redshift (z=2), rotating galaxies with high star formation rates and turbulent gas velocities of sigma=40-80 km/s is investigated. Fitting the observed disk rotational velocities and radii with a Mo, Mao, White (1998) (MMW) model requires unusually large disk spin parameters lambda_d>0.1 and disk-to-dark halo mass fraction m_d=0.2, close to the cosmic baryon fraction. The galaxies segregate into dispersion-dominated systems with 1<vmax/sigma<3, maximum rotational velocities vmax<200 km/s and disk half-light radii rd=1-3 kpc and rotation-dominated systems with vmax>200 km/s, vmax/sigma>3 and rd=4-8 kpc. For the dispersion-dominated sample, radial pressure gradients partly compensate the gravitational force, reducing the rotational velocities. Including this pressure effect in the MMW model, dispersion-dominated galaxies can be fitted well with spin parameters lf lambda_d=0.03-0.05 for high disk mass fractions of m_d=0.2 and with lambda_d=0.01-0.03 for m_d=0.05. These values are in good agreement with cosmological expectations. For the rotation-dominated sample however pressure effects are small and better agreement with theoretically expected disk spin parameters can only be achieved if the dark halo mass contribution in the visible disk regime (2-3*rd) is smaller than predicted by the MMW model. We argue that these galaxies can still be embedded in standard cold dark matter halos if the halos did not contract adiabatically in response to disk formation. It is shown that the observed high turbulent gas motions of the galaxies are consistent with a Toomre instability parameter Q=1 which is equal to the critical value, expected for gravitational disk instability to be the major driver of turbulence. The dominant energy source of turbulence is then the potential energy of the gas in the disk.Comment: 23 pages, 4 figures, ApJ, in pres

Halo density reduction by baryonic settling?

We test the proposal by El-Zant et al that the dark matter density of halos could be reduced through dynamical friction acting on heavy baryonic clumps in the early stages of galaxy formation. Using N-body simulations, we confirm that the inner halo density cusp is flattened to 0.2 of the halo break radius by the settling of a single clump of mass \ga 0.5% of the halo mass. We also find that an ensemble of 50 clumps each having masses \ga 0.2% can flatten the cusp to almost the halo break radius on a time scale of \sim9 Gyr, for an NFW halo of concentration 15. We summarize some of the difficulties that need to be overcome if this mechanism is to resolve the apparent conflict between the observed inner densities of galaxy halos and the predictions of LCDM.Comment: 7 pages, 6 figures, uses emulateap