Development and dynamics of the Atlantic rainforest during the Late Quaternary and its connections with the climate system

The Atlantic rainforest harbour an outstandingly high biodiversirty. Many different environmental factors (climate, soil, geomorphology, ocean and etc) interact in a very large space creating complex ecosystems with high endemism. Altough, its richness, the Altnatic rainforest is highly endangered due to increasing human impact through the intensification of land-use and consequent broad landscape replacement. Many palaecological studies have been developed during the last decades providing important background of diverse location around Atlantic rainforest, however little is known about regional palaeoecological history and landscape dynamics. In this study, we present palynological analyses carried out in a compilation of several pollen records from Alantic rainforest ecosystems and surrounding regions that help to unveil patterns and processes in present and past vegetation change during the Late Quaternary. A palaeoecological study of 3 time periods (3000 yrs BP, pre-colonization and modern) of 27 pollen records of Atlantic rainforest and associated ecosystems reveals marked vegetation changes as consequence of climate and human impacts during the Late Holocene. The samples concerning the pre-colonization period was used as standard for comparison once it represents the natural vegetation conditions once climate was similar to today and there was no human impact on it. Handling multivariate techniques associated to pollen abundaces threshold, the pre-colonization period was classified into 7 groups. Moreover, it was noticed a clear differentiation between grassland and forested vegetation and between tropical and subtropical vegetation types. The comparison of pre-colonization with the other two time slices revealed that using Poaceae threshold most of sites from 3,000 BP and modern assemblages maintained their classification. Furthermore, combining with other taxa abundance, the number of sites with the same classification became reduced. Using square chord dissimilarity as a quantitative of change indicator, the change prompted by human actions within 500 years of colonization and 3,000 years of natural changes were equivalent. Comparing pre-colonization with surface samples, it is noticed that modern pollen still able to represent important environmental gradients however, their use as modern analogue requires careful treatment. Oonce fossil pollen are the best indicators to track past vegetation changes, we carried out a parallel analysis of 19 pollen records to unveil the regional vegetation history allowing inferences about synchronoicity. The accumulated probability distributions show potential synchronous vegetation at 8900, 5900, 2800, 1200 and 550 cal yrs BP. The southern sites experienced more cycles of changes than others, mainly during the late Holocene. The main variations on pollen spectra were captured by both PC and rate of change analysis, that well represented the main periods of change. In general, the early Holocene was a stable period, after the mid-Holocene the changes have started and intensified around 2800 cal yrs BP with other pulses later on agreeing with other researches carried out at other regions of South America indicating connections with continental climate patterns associated to South American monsoon. The application of unconstrained cluster analysis and pollen abundance threshold to 16 pollen samples from southern andsoutheastern Brazil, revealed that although no large temporal pattern is noticed, the used of appropriate technique can give a broad perspective of vegetation type atspecific time. Moreover, the clear differentiation of vegetation among different times was successfully achived revealing the major variation of vegetation between open and forested landscapes

Técnicas do Rastramento Ocular no Diagnóstico do Transtorno Depressivo: uma revisão sistemática

This systematic review aimed to verify the empirical evidence of the application of the eye tracking technique in depressive disorder. The PubMed, PsyInfo and Web of Science databases were used, using the following descriptors: ((Depression OR "Affective Disorders") AND ("Eye Tracking" OR Eye-Tracking OR "Eye Movements" OR "Eye Tracker" OR "Eye Gaze")). According to the eligibility criteria, sixteen relevant studies were identified and its methods, results and their main limitations were verified. The results suggest an increase in latency and reaction time to detect complex stimuli, e.g. the recognition of emotional facial expressions. In addition, greater numbers of fixations in stimuli of negative emotional content were observed. The findings demonstrate that changes in eye movement measurements in depressive disorder are associated with an attentional bias mechanism. It is concluded that Eye Tracking is a useful tool for psychophysiological assessment of depressive disorder.Esta revisão sistemática teve como objetivo verificar as evidências empíricas da aplicação da técnica de rastreamento ocular no transtorno depressivo. Foram utilizadas as bases de dados PubMed, PsyInfo e Web of Science, utilizando os seguintes descritores: ((Depression OR "Affective Disorders") AND ("Eye Tracking" OR Eye-Tracking OR "Eye Movements" OR "Eye Tracker" OR "Eye Gaze")). De acordo com os critérios de elegibilidade, foram identificados cinco estudos relevantes e verificados seus métodos, resultados e suas principais limitações. Os resultados sugerem um aumento na latência e no tempo de reação para detectar estímulos complexos, por ex. o reconhecimento de expressões faciais emocionais. Além disso, observou-se um maior número de fixações em estímulos de conteúdo emocional negativo. Os resultados demonstram que as alterações nas medidas dos movimentos oculares no transtorno depressivo estão associadas a um mecanismo de viés de atenção. Conclui-se que o rastreamento ocular é uma ferramenta útil para avaliação psicofisiológica do transtorno depressivo

Drosophila Ana2 is a conserved centriole duplication factor

Drosophila protein Ana2 supports de novo formation of centrioles and may be a functional homologue of the C. elegans centriole duplication protein SAS-5

Reducing antioxidant capacity evaluated by means of a controlled potential oxidative attack

An analytical method suitable for an antioxidant sensor is presented following the response of these substances to an extensive oxidative attack imposed by electrochemical means. The electrochemical assay simulates the action of a reactive oxygen species (ROS) by means of electrolyses carried out at a potential which is settled at the formal potential of the ROS. The antioxidant activities of trolox and ascorbic, gallic and caffeic acids and of mixtures these antioxidants was estimated from the charge required for the complete oxidation of the antioxidants from assays where the oxidative attack by O2 and by O2 were simulated.Fundação para a Ciência e Tecnologia (FCT)Centro de Química da Universidade do Minh

Angelman Syndrome Protein UBE3A Interacts with Primary Microcephaly Protein ASPM, Localizes to Centrosomes and Regulates Chromosome Segregation

Many proteins associated with the phenotype microcephaly have been localized to the centrosome or linked to it functionally. All the seven autosomal recessive primary microcephaly (MCPH) proteins localize at the centrosome. Microcephalic osteodysplastic primordial dwarfism type II protein PCNT and Seckel syndrome (also characterized by severe microcephaly) protein ATR are also centrosomal proteins. All of the above findings show the importance of centrosomal proteins as the key players in neurogenesis and brain development. However, the exact mechanism as to how the loss-of-function of these proteins leads to microcephaly remains to be elucidated. To gain insight into the function of the most commonly mutated MCPH gene ASPM, we used the yeast two-hybrid technique to screen a human fetal brain cDNA library with an ASPM bait. The analysis identified Angelman syndrome gene product UBE3A as an ASPM interactor. Like ASPM, UBE3A also localizes to the centrosome. The identification of UBE3A as an ASPM interactor is not surprising as more than 80% of Angelman syndrome patients have microcephaly. However, unlike in MCPH, microcephaly is postnatal in Angelman syndrome patients. Our results show that UBE3A is a cell cycle regulated protein and its level peaks in mitosis. The shRNA knockdown of UBE3A in HEK293 cells led to many mitotic abnormalities including chromosome missegregation, abnormal cytokinesis and apoptosis. Thus our study links Angelman syndrome protein UBE3A to ASPM, centrosome and mitosis for the first time. We suggest that a defective chromosome segregation mechanism is responsible for the development of microcephaly in Angelman syndrome

Post Eclosion Age Predicts the Prevalence of Midgut Trypanosome Infections in Glossina

The teneral phenomenon, as observed in Glossina sp., refers to the increased susceptibility of the fly to trypanosome infection when the first bloodmeal taken is trypanosome-infected. In recent years, the term teneral has gradually become synonymous with unfed, and thus fails to consider the age of the newly emerged fly at the time the first bloodmeal is taken. Furthermore, conflicting evidence exists of the effect of the age of the teneral fly post eclosion when it is given the infected first bloodmeal in determining the infection prevalence. This study demonstrates that it is not the feeding history of the fly but rather the age (hours after eclosion of the fly from the puparium) of the fly when it takes the first (infective) bloodmeal that determines the level of fly susceptibility to trypanosome infection. We examine this phenomenon in male and female flies from two distinct tsetse clades (Glossina morsitans morsitans and Glossina palpalis palpalis) infected with two salivarian trypanosome species, Trypanosoma (Trypanozoon) brucei brucei and Trypanosoma (Nannomonas) congolense using Fisher's exact test to examine differences in infection rates. Teneral tsetse aged less than 24 hours post-eclosion (h.p.e.) are twice as susceptible to trypanosome infection as flies aged 48 h.p.e. This trend is conserved across sex, vector clade and parasite species. The life cycle stage of the parasite fed to the fly (mammalian versus insect form trypanosomes) does not alter this age-related bias in infection. Reducing the numbers of parasites fed to 48 h.p.e., but not to 24 h.p.e. flies, increases teneral refractoriness. The importance of this phenomenon in disease biology in the field as well as the necessity of employing flies of consistent age in laboratory-based infection studies is discussed

Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter