Exploring the effects of COVID-19-related traumatic events on the mental health of university students in Brazil: A cross-sectional investigation

University students are vulnerable to mental health issues during their academic lives. During the COVID-19 pandemic, university students faced mental distress due to lockdowns and the transition to e-learning. However, it is not known whether these students were also affected specifically by COVID-19-related traumatic events. This study examined the impact of COVID-19-related traumatic events on 2277 university students from two federal institutions of higher education in Brazil. The university students completed an online questionnaire covering demographics, lifestyle habits, health characteristics, COVID-19-related traumatic events, and depression, anxiety, and stress symptoms. The results showed that an increased intensity of COVID-19-related traumatic events was positively associated with stress, anxiety, and depressive symptoms, and each specific type of event was associated with these symptoms. In addition, we found a negative association between these symptoms and male sex and age and a positive association with having or having had a history of cardiovascular, respiratory, neurological, or mental disorders or another disease diagnosed by a physician. In conclusion, this study emphasizes the heightened risk of mental health issues in university students in the face of COVID-19-related traumatic events. Women, young people and people who have or have had a history of disease were the most vulnerable to mental health issues during the COVID-19 pandemic.

Investigating luxS gene expression in lactobacilli along lab-scale cocoa fermentations

Previous metagenomic analyses have suggested that lactobacilli present potential for Quorum Sensing (QS) in cocoa fermentation, and in the present research, laboratory scale fermentations were carried out to monitor the expression of luxS, a universal marker of QS. For that, 96 h-fermentations were studied, as follows: F0 (non inoculated control), F1 (inoculated with yeasts, lactic acid bacteria, and acetic acid bacteria), F2 (inoculated with yeasts and acetic acid bacteria), F3 (inoculated with yeasts only). The parameters evaluated were: plate counting, quantification of key enzymes and analysis of volatile organic compounds associated with key sensory descriptors, using headspace gas chromatography-mass spectrometry (GC-MS). Furthermore, QS was estimated by the quantification of the expression of luxS genes by Reverse Transcriptase Real-Time PCR. The results demonstrated that microbial succession occurred in pilot scale fermentations, but no statistical differences for microbial enumeration and α-diversity index were observed among experiments and control. Moreover, it was not possible to make conclusive correlations of enzymatic profile and fermenting microbiota, likely due to the intrinsic activity of plant hydrolases. Regarding to the expression of luxS genes, in Lactiplantibacillus plantarum they were active along the fermentation, but for Limosilactobacillus fermentum, luxS was expressed only at early and middle phases. Correlation analysis of luxS expression and production of volatile metabolites evidenced a possible negative association of Lp. Plantarum with fermentation quality. In conclusion, these data corroborate former shotgun metagenomic analysis by demonstrating the expression of luxS by lactobacilli in pilot scale cocoa fermentation and evidence Lp. Plantarum is the main lactic acid bacteria related to its expression.

The top-100 cited articles on post-traumatic stress disorder: a historical bibliometric analysis

This is a bibliometric analysis of the most-cited articles on post-traumatic stress disorder (PTSD) with the objective of identifying citation patterns for researchers, journals, centers, periods, topics, and nations. A search was conducted in Thomson Reuters' WoS Core Collection employing the expression TI = (posttraumatic stress disorder OR post-traumatic stress disorder OR PTSD). The 100 most-cited articles were downloaded, and the relevant data were extracted and analyzed. These studies had a total of 69,649 citations, ranging from a minimum of 360 to a maximum of 6029 citations, with an average of 696.49, a standard deviation of 720.92, mode of 369, and a median of 512. Eighty-eight percent of the most-cited articles on PTSD originated from the USA, with just six cities accounting for 52% of the publications and the Boston area alone responsible for almost one-fifth of the total output. The universities of Yale and Harvard headed the ranking of institutions with larger numbers of highly-cited articles. Female researchers represented 42.3% of all authors, 51% of the first authors, and 48% of the corresponding authors. The proportion of M.D. authors decreased significantly between the 1980-1999 (42%) and the 2000-2019 (27.2%) periods while that of Ph.D. authors increased from 44% to 57.4%. The most studied population was military veterans (28%). Female victims of sexual or physical violence, traumatized children, and adult survivors of childhood abuse were assessed in only 6-7% of the most-cited publications. Ten clinical trials evaluated psychological interventions but only three investigated pharmacotherapy. We concluded that influential research on PTSD remains centralized in the USA. A balanced gender representation in publications was found. There was a heavy reliance on combat veterans as the study population. Few highly-cited studies on the pharmacotherapy for PTSD were identified. Focused efforts are needed to address these challenges.

Machine learning applied to fMRI patterns of brain activation in response to mutilation pictures predicts PTSD symptoms

BACKGROUND

The present study aimed to apply multivariate pattern recognition methods to predict posttraumatic stress symptoms from whole-brain activation patterns during two contexts where the aversiveness of unpleasant pictures was manipulated by the presence or absence of safety cues.

METHODS

Trauma-exposed participants were presented with neutral and mutilation pictures during functional magnetic resonance imaging (fMRI) collection. Before the presentation of pictures, a text informed the subjects that the pictures were fictitious ("safe context") or real-life scenes ("real context"). We trained machine learning regression models (Gaussian process regression (GPR)) to predict PTSD symptoms in real and safe contexts.

RESULTS

The GPR model could predict PTSD symptoms from brain responses to mutilation pictures in the real context but not in the safe context. The brain regions with the highest contribution to the model were the occipito-parietal regions, including the superior parietal gyrus, inferior parietal gyrus, and supramarginal gyrus. Additional analysis showed that GPR regression models accurately predicted clusters of PTSD symptoms, nominal intrusion, avoidance, and alterations in cognition. As expected, we obtained very similar results as those obtained in a model predicting PTSD total symptoms.

CONCLUSION

This study is the first to show that machine learning applied to fMRI data collected in an aversive context can predict not only PTSD total symptoms but also clusters of PTSD symptoms in a more aversive context. Furthermore, this approach was able to identify potential biomarkers for PTSD, especially in occipitoparietal regions.

Emotionally subjective reactivity to cervical cytology pictures is modulated by expertise

Our aims were to create a catalog of cytological pictures and to evaluate the valence (level of pleasantness/unpleasantness) and arousal (level of calm/excitement) of these pictures in individuals with different occupations. The sample consisted of medical and law college students and cytopathologists. Valence and arousal score for general pictures were not modulated by expertise in cytology. However, students judged the cytological pictures to be lower in valence and in arousal than the cytopathologists. The cytopathologists classified cytological pictures with lesions as lower in valence and higher in arousal than cytological pictures without lesions.

The different impacts of COVID-19 on the mental health of distinct health care worker categories

The present study sought to explore the factors associated with the odds of having probable depression and posttraumatic stress disorder (PTSD) related to traumatic COVID-19 experiences and their impact on health care workers in distinct categories. In this cross-sectional study, 1843 health care workers (nurses, nurse technicians, physicians, physical therapists, and other healthcare workers) were recruited via convenience sampling. A survey was administered to obtain information regarding sociodemographic, occupational, and mental health status. Descriptive statistics and multivariable logistic regression were used for the analyses. Being a nurse technician was associated with an odds ratio of 1.76 for probable PTSD. No relation was observed between health care worker categories and the odds of probable depression. Additionally, being female and not receiving adequate PPE were related to greater odds of having probable PTSD and depression.

Tonic immobility is associated with posttraumatic stress symptoms in healthcare professionals exposed to COVID-19-related trauma

The Coronavirus Disease 2019 (COVID-19) pandemic has exposed healthcare workers (HCW) to traumatic situations that might lead to the development of posttraumatic stress disorder (PTSD). An important vulnerability factor for PTSD is the peritraumatic tonic immobility (TI) reaction, an involuntary and reflexive defensive response evoked by an intense and inescapable threat. TI is largely understudied in humans and has not been investigated during trauma related to COVID-19. For HCW, the pandemic context might be experienced as an intense and potentially inescapable threat, i.e., an overwhelming situation. Here, we investigated if TI response occurred during traumatic events related to the pandemic and its association with posttraumatic stress symptoms (PTSS). An online survey of 1001 HCW investigated COVID-19-related traumatic experiences, TI and PTSS. TI was reported for all types of traumatic events, and multivariate regression models revealed that TI was significantly associated with PTSS severity. HCW who reported high TI scores exhibited an increase of 9.08 times the probability of having a probable diagnosis of PTSD. Thus, TI was evoked by pandemic-related traumatic situations and associated with PTSS severity and higher odds of a PTSD diagnosis. Tonic immobility occurrence should be screened, and psychoeducation about its reflexive biological nature should be introduced.

Towards diversity in science - a glance at gender disparity in the Brazilian Society of Neuroscience and Behavior (SBNeC)

Gender equity is far from being achieved in most academic institutions worldwide. Women representation in scientific leadership faces multiple obstacles. Implicit bias and stereotype threat are considered important driving forces concerning gender disparities. Negative cultural stereotypes of weak scientific performance, unrelated to true capacity, are implicitly associated with women and other social groups, influencing, without awareness, attitudes and judgments towards them. Meetings of scientific societies are the forum in which members from all stages of scientific careers are brought together. Visibility in the scientific community stems partly from presenting research as a speaker. Here, we investigated gender disparities in the Brazilian Society of Neuroscience and Behavior (SBNeC). Across the 15 mandates (1978-2020), women occupied 30% of the directory board posts, and only twice was a woman president. We evaluated six meetings held between 2010 and 2019. During this period, the membership of women outnumbered that of men in all categories. A total of 57.50% of faculty members, representing the potential pool of speakers and chairs, were female. Compared to this expected value, female speakers across the six meetings were scarce in full conferences (χ²(5)=173.54, P<0.001) and low in symposia (χ²(5)=36.92, P<0.001). Additionally, women chaired fewer symposia (χ²(5)=47.83, P<0.001). Furthermore, men-chaired symposia had significantly fewer women speakers than women-chaired symposia (χ²(1)=56.44, P<0.001). The gender disparities observed here are similar to those in other scientific societies worldwide, urging them to lead actions to pursue gender balance and diversity. Diversity leads not only to fairness but also to higher-quality science.

The invisible scars of emotional abuse: a common and highly harmful form of childhood maltreatment

BACKGROUND

Childhood maltreatment (CM) is unfortunately widespread globally and has been linked with an increased risk of a variety of psychiatric disorders in adults, including posttraumatic stress disorder (PTSD). These associations are well established in the literature for some maltreatment forms, such as sexual and physical abuse. However, the effects of emotional maltreatment are much less explored, even though this type figures among the most common forms of childhood maltreatment. Thus, the present study aims to investigate the impact of each type of childhood maltreatment, both individually and conjointly, on revictimization and PTSD symptom severity using a nonclinical college student sample.

METHODS

Five hundred and two graduate and undergraduate students participated in the study by completing questionnaires assessing lifetime traumatic experiences in general, maltreatment during childhood and PTSD symptoms. Bivariate and multivariate negative binomial regressions were applied to examine the associations among childhood maltreatment, revictimization, and PTSD symptom severity.

RESULTS

Our results showed that using bivariate models, all types of CM were significantly associated with revictimization and PTSD symptom severity. Multivariate models showed that emotional abuse was the type of maltreatment associated with the highest incidence rates of revictimization and PTSD symptom severity.

CONCLUSIONS

These data provide additional evidence of the harmful effects of childhood maltreatment and its long-term consequences for individuals' mental health. Notably, the findings highlight the importance of studying the impacts of emotional abuse, which seems to be a highly prevalent, understudied, and chronic form of maltreatment that is as toxic as other maltreatment forms.

Assessing impacts of future climate change on extreme fire weather and pyro-regions in Iberian Peninsula

Weather conditions play an important role in wildfire activity. In many regions, future climate could lead to different fire weather, with impacts on the ignition, behaviour, and suppression of wildfires, which may, therefore, force new fire regimes. This study aimed to assess the evolution of fire weather indices and the Number of Extreme Days (NED) in the context of climate change. We estimated the impact of these changes on monthly Normalized Burnt Area (NBA) and in the spatial distribution of Pyro-Regions (PR), using a recently identified relationship between NED and NBA intra-annual patterns. The components of the Canadian Forest Fire Weather Index System (CFFWIS) in the Iberian Peninsula were analysed for present-day conditions and future climate scenarios, using daily data from ERA-Interim (1980-2014) and an ensemble of simulations from 11 EURO-CORDEX high spatial resolution models, for two future periods (2041-2070 and 2071-2100) and scenarios (RCP4.5 and RCP8.5). Results suggest a significant increase in future fire weather risk, especially in late spring and early autumn, and also in southern and eastern Iberian Peninsula. NED is expected to strongly increase in summer months in the four PRs, but also to decrease in March and April in the northwestern and southwestern PR. This could change the spatial distribution of PRs, with a general northwards movement: the northern PR is expected to disappear except north of the Cantabrian Mountains, being replaced by the northwestern PR; the southwestern PR is expected to grow and occupy part of the area currently in the northwestern PR; and a new PR could appear in parts of the current eastern PR. These PR changes follow the projected modifications in the major climate regions. Results suggest different fire regimes in the future, with higher fire weather risk, and a longer and harsher fire season.

Vulnerability and Protective Factors for PTSD and Depression Symptoms Among Healthcare Workers During COVID-19: A Machine Learning Approach

Background: Healthcare workers are at high risk for developing mental health problems during the COVID-19 pandemic. There is an urgent need to identify vulnerability and protective factors related to the severity of psychiatric symptoms among healthcare workers to implement targeted prevention and intervention programs to reduce the mental health burden worldwide during COVID-19. Objective: The present study aimed to apply a machine learning approach to predict depression and PTSD symptoms based on psychometric questions that assessed: (1) the level of stress due to being isolated from one's family; (2) professional recognition before and during the pandemic; and (3) altruistic acceptance of risk during the COVID-19 pandemic among healthcare workers. Methods: A total of 437 healthcare workers who experienced some level of isolation at the time of the pandemic participated in the study. Data were collected using a web survey conducted between June 12, 2020, and September 19, 2020. We trained two regression models to predict PTSD and depression symptoms. Pattern regression analyses consisted of a linear epsilon-insensitive support vector machine (ε-SVM). Predicted and actual clinical scores were compared using Pearson's correlation coefficient (r), the coefficient of determination (r²), and the normalized mean squared error (NMSE) to evaluate the model performance. A permutation test was applied to estimate significance levels. Results: Results were significant using two different cross-validation strategies to significantly decode both PTSD and depression symptoms. For all of the models, the stress due to social isolation and professional recognition were the variables with the greatest contributions to the predictive function. Interestingly, professional recognition had a negative predictive value, indicating an inverse relationship with PTSD and depression symptoms. Conclusions: Our findings emphasize the protective role of professional recognition and the vulnerability role of the level of stress due to social isolation in the severity of posttraumatic stress and depression symptoms. The insights gleaned from the current study will advance efforts in terms of intervention programs and public health messaging.

Dyadic Adjustment and Sexual Satisfaction in HPV Diagnosed Portuguese Women: A Longitudinal Study

This study examined the relationship between dyadic adjustment and sexual satisfaction, in Portuguese women diagnosed with human papillomavirus (HPV), using a 1-year longitudinal design. Women were assessed at the beginning of the study (N = 209), six months after (N = 178) and twelve months later (N = 105). A better dyadic adjustment predicted more sexual satisfaction but the inverse was not observed. Younger women (< 40 years) showed greater difficulties in dyadic adjustment, while older women (> 40 years) reported lower sexual satisfaction. Findings highlight the importance of intervening with couples, using different intervention programs according to women's age.

Interactions between emotion and action in the brain

A growing literature supports the existence of interactions between emotion and action in the brain, and the central participation of the anterior midcingulate cortex (aMCC) in this regard. In the present functional magnetic resonance imaging study, we sought to investigate the role of self-relevance during such interactions by varying the context in which threating pictures were presented (with guns pointed towards or away from the observer). Participants performed a simple visual detection task following exposure to such stimuli. Except for voxelwise tests, we adopted a Bayesian analysis framework which evaluated evidence for the hypotheses of interest, given the data, in a continuous fashion. Behaviorally, our results demonstrated a valence by context interaction such that there was a tendency of speeding up responses to targets after viewing threat pictures directed towards the participant. In the brain, interaction patterns that paralleled those observed behaviorally were observed most notably in the middle temporal gyrus, supplementary motor area, precentral gyrus, and anterior insula. In these regions, activity was overall greater during threat conditions relative to neutral ones, and this effect was enhanced in the directed towards context. A valence by context interaction was observed in the aMCC too, where we also observed a correlation (across participants) of evoked responses and reaction time data. Taken together, our study revealed the context-sensitive engagement of motor-related areas during emotional perception, thus supporting the idea that emotion and action interact in important ways in the brain.

Drought in Portugal: Current regime, comparison of indices and impacts on extreme wildfires

In Portugal, drought characterizes the climatic variability, contributes to the increase of fire risk and its duration and intensity are expected to increase in future climate. Surprisingly, the quantitative and objective analysis to characterize the drought regime in current climate conditions as well as its influence on the occurrence of large wildfires (LW) has never been done for Portugal, which are the main objectives of this study. We assessed drought regime for recent past climate conditions (1981-2017), using four different drought indices, namely SPI, SPEI, RDI and VCI, and assessed the influence of drought in LW occurrence. Results include the characterization of drought number, duration, severity, intensity, extension, intra- and inter-annual variability for different classes of severity and the space-time distribution of LW in drought periods and affected area. Our main findings include 67% of the study period were drought months; regions with higher drought duration and severity assessed with SPI and SPEI for general drought conditions evolves from north to south with the increase of drought assessment period; drought characteristics present low intra - annual and inter - annual variability but are clearly associated to the temporal and spatial distribution of LW. In fact, all LW occurred during drought assessed with SPI or SPEI, almost all LW (97% to 95%) and corresponding burnt area (98% to 97%) occurred during drought assessed with SPI and SPEI. The relationship between drought and fire incidence is statistical significant for 3 - month SPI, 3 - and 6 - month SPEI, and is particularly strong for Moderate and Severe drought. 85% and 87% of LW occurred in area affected by drought assessed with SPI or SPEI, respectively. It is not clear which is the best index, but drought plays a fundamental role in the occurrence of large wildfires in Portugal.

How do you perceive threat? It's all in your pattern of brain activity

Whether subtle differences in the emotional context during threat perception can be detected by multi-voxel pattern analysis (MVPA) remains a topic of debate. To investigate this question, we compared the ability of pattern recognition analysis to discriminate between patterns of brain activity to a threatening versus a physically paired neutral stimulus in two different emotional contexts (the stimulus being directed towards or away from the viewer). The directionality of the stimuli is known to be an important factor in activating different defensive responses. Using multiple kernel learning (MKL) classification models, we accurately discriminated patterns of brain activation to threat versus neutral stimuli in the directed towards context but not during the directed away context. Furthermore, we investigated whether it was possible to decode an individual’s subjective threat perception from patterns of whole-brain activity to threatening stimuli in the different emotional contexts using MKL regression models. Interestingly, we were able to accurately predict the subjective threat perception index from the pattern of brain activation to threat only during the directed away context. These results show that subtle differences in the emotional context during threat perception can be detected by MVPA. In the directed towards context, the threat perception was more intense, potentially producing more homogeneous patterns of brain activation across individuals. In the directed away context, the threat perception was relatively less intense and more variable across individuals, enabling the regression model to successfully capture the individual differences and predict the subjective threat perception.

Dyadic Adjustment in HPV-Infected Women One Year After Diagnosis

Objective: This study examined the contribution of age, type of human papillomavirus (HPV), attachment, sexual satisfaction, and spirituality in dyadic adjustment in women with HPV from diagnosis to one year later. Method: This is a longitudinal study with three assessment moments: (T1) at the diagnosis appointment, (T2) six months after, and (T3) 12 months after the diagnosis. Participants answered a sociodemographic questionnaire as well as several other measures: HPV Knowledge Questionnaire (HPVQ), Papanicolaou Exam Knowledge Questionnaire (PEK-Q), Hospital Anxiety and Depression Scale (HADS), Courtauld Emotional Control Scale (CECS), Index of Sexual Satisfaction (ISS), Experiences in Close Relationship Scale-Short Form (ECR-S), Spiritual and Religious Attitudes in Dealing With Illness (SpREUK), and the Revised Dyadic Adjustment Scale (RDAS). Results: Age showed a positive impact on sexual dissatisfaction at T2. Sexual dissatisfaction at T1 predicted sexual dissatisfaction at T2 and dyadic adjustment at T3. Spirituality and insecure attachment at T1 negatively predicted insecure attachment at T2, and the latter predicted dyadic adjustment at T3. Conclusions: The results corroborate the need to assess the dyad when women are diagnosed with HPV. Only then it will be possible to design differentiated intervention programs that take into consideration women's age, attachment style, and sexual satisfaction. Interventions should also include women's partners to promote dyadic adjustment in this population.

Negligent and intentional fires in Portugal: Spatial distribution characterization

In the European context, Portugal is the country with the highest number of wildfires and the second with more burnt area. The vast majority of these events are of human origin, whether caused by accident, negligence or arson, reason why it is particularly important to know the regime of these wildfires for forest and wildfire management activities. The study focuses on the most recent years of 2001-2014, when wildfire ignition's coordinates are known, and aims to identify and characterize the wildfire incidence spatial patterns of variability as well as their main drivers. After grouping wildfires with human cause into negligent and intentional, we studied their spatial distribution in terms of normalized number of wildfires (NNF) and burnt area (NBA) in the five Nomenclature of Territorial Units for Statistics II regions of mainland Portugal. Results disclose an uneven spatial distribution of the fire incidence, characterized by a south-north gradient, much higher values in Norte region and more evident for intentional than for negligent wildfires. Human and biophysical drivers strongly influence NNF and NBA, at regional and national scales. Distribution patterns at regional scale, for negligent and intentional wildfires are quite different from entire mainland and all wildfires. Drivers' influence is higher for intentional than for negligent wildfires, for southern than for northern regions and for NBA than for NNF. The leading drivers of NNF are distance to roads (d) population density (pd) and altitude (h) while of NBA are h, d, slope and pd, and this influence is higher for intentional than for negligent wildfires.

Effects of a Physiotherapeutic Protocol in Respiratory Function, Aerobic Capacity and Quality of Life After Kidney Transplantation

INTRODUCTION

Chronic kidney disease can lead to dysfunction of the respiratory, cardiac, and musculoskeletal systems, altering the body's metabolism. Renal transplantation and hospital physiotherapy, through specific protocols, can improve these dysfunctions.

OBJECTIVES

This study evaluates the impact of a hospital physiotherapeutic protocol in quality of life (QoL), respiratory muscle strength, peak expiratory flow, and 6-minute walk test (6MWT) in the preoperative, first, and fifth days after renal transplantation.

METHODS

We evaluated 39 patients who received a renal transplant at Clinics Hospital of University of Campinas for respiratory muscle strength, expiratory peak flow, and functional capacity by the 6MWT. The short form-36 quality of life questionnaire was applied to 12 patients.

RESULTS

We observed a significant reduction in respiratory muscle strength and peak expiratory flow in the first postoperative day. On postoperative day 5, there was improvement in respiratory muscle strength and expiratory peak flow. However, aerobic capacity measured by 6MWT remained below predicted. Analysis of QoL showed an improvement in almost all analyzed domains after transplantation.

CONCLUSION

A specific physiotherapeutic protocol applied early after transplantation provided recovery of respiratory muscle strength and QoL. However, longer training is necessary to obtain adequate aerobic rehabilitation.

Mediterranean Diet and Musculoskeletal-Functional Outcomes in Community-Dwelling Older People: A Systematic Review and Meta-Analysis

BACKGROUND

Population aging is increasing and this process together with its characteristics influence the prevalence and incidence of chronic conditions and musculoskeletal-functional outcomes such as frailty, functional disability and sarcopenia. Nutritional strategies focused on dietary patterns, such as a Mediterranean diet, can be protective from these outcomes.

PURPOSE

To investigate the association between adherence to a Mediterranean diet and frailty, functional disability and sarcopenia in community-dwelling older people.

METHODS

We systematically reviewed electronic databases (MEDLINE, EMBASE, and others) and grey literature for articles investigating the relationship between adherence to a Mediterranean diet and frailty, functional disability and sarcopenia in community-dwelling people aged 60 and over. Study selection, quality of study assessment and data extraction were conducted independently by two authors. Random effects meta-analyses were performed, and pooled Odds Ratios (OR) were obtained.

RESULTS

After the literature search, screening and eligibility investigation, we included 12studies, with a total of 20,518 subjects. A higher adherence to a Mediterranean diet was found to be inversely associated with frailty (OR 0.42, 95% CI: 0.28-0.65, I2=24.9%, p=0.262) and functional disability (OR 0.75, 95% CI: 0.61-0.93, I2=0.0%, p=0.78). Highly different study characteristics prevented us from performing a meta-analysis for sarcopenia. Cohort data indicated no association between adherence to a Mediterranean diet and sarcopenia; however, cross-sectional results showed a positive relationship.

CONCLUSION

A Mediterranean diet is protective of frailty and functional disability, but not of sarcopenia. More longitudinal studies are needed to understand the relationship between a Mediterranean diet and sarcopenia.

Indices estimated using REML/BLUP and introduction of a super-trait for the selection of progenies in popcorn

Selection indices commonly utilize economic weights, which become arbitrary genetic gains. In popcorn, this is even more evident due to the negative correlation between the main characteristics of economic importance - grain yield and popping expansion. As an option in the use of classical biometrics as a selection index, the optimal procedure restricted maximum likelihood/best linear unbiased predictor (REML/BLUP) allows the simultaneous estimation of genetic parameters and the prediction of genotypic values. Based on the mixed model methodology, the objective of this study was to investigate the comparative efficiency of eight selection indices estimated by REML/BLUP for the effective selection of superior popcorn families in the eighth intrapopulation recurrent selection cycle. We also investigated the efficiency of the inclusion of the variable "expanded popcorn volume per hectare" in the most advantageous selection of superior progenies. In total, 200 full-sib families were evaluated in two different areas in the North and Northwest regions of the State of Rio de Janeiro, Brazil. The REML/BLUP procedure resulted in higher estimated gains than those obtained with classical biometric selection index methodologies and should be incorporated into the selection of progenies. The following indices resulted in higher gains in the characteristics of greatest economic importance: the classical selection index/values attributed by trial, via REML/BLUP, and the greatest genotypic values/expanded popcorn volume per hectare, via REML. The expanded popcorn volume per hectare characteristic enabled satisfactory gains in grain yield and popping expansion; this characteristic should be considered super-trait in popcorn breeding programs.

Phylogeography and population structure analysis reveals diversity by mutations in Lasiodiplodia theobromae with distinct sources of selection

Lasiodiplodia theobromae is a plant pathogen with a worldwide distribution, with low host specificity, causing stem cankers, dieback diseases, and fruit rot in several species of plants. In coconut, this pathogen is reported as the etiological agent of "coconut leaf blight" (CLB) disease, causing several losses in fruit production. The CLB is an important disease for this crop in Brazil. In our study, we used a phylogeographic approach through the molecular characterization of the translation elongation factor 1-α (TEF1-α) to elucidate the pathogen distribution in Brazil and other countries, besides, search information about diversity sources of this pathogen in coconut palm tree at Brazilian northern, northeast, and southeast. We found that L. theobromae diversity is within populations (locations), and populations that are located closest to the center of the tropical zone have more variability as Central Africa, Brazilian Southeast, and Northeast. The widespread distribution could be in part related with long-distance dispersal via global trade of plants and plant products. The entrance route of L. theobromae in Brazil probably occurred from Africa route and not occurred once. In Brazil, the diversity of this pathogen in coconut tree could be linked to two agents of selection: high host diversity (in Northeast) and distinct management measures adopted in Southeast. These different sources of selection, mainly the mutations, could be one of the reasons that we found distinct reactions to "coconut leaf blight" chemical control in these regions.

Molecular analysis of genetic diversity among vine accessions using DNA markers

Viticulture presents a number of economic and social advantages, such as increasing employment levels and fixing the labor force in rural areas. With the aim of initiating a program of genetic improvement in grapevine from the State University of the state of Rio de Janeiro North Darcy Ribeiro, genetic diversity between 40 genotypes (varieties, rootstock, and species of different subgenera) was evaluated using Random amplified polymorphic DNA (RAPD) molecular markers. We built a matrix of binary data, whereby the presence of a band was assigned as "1" and the absence of a band was assigned as "0." The genetic distance was calculated between pairs of genotypes based on the arithmetic complement from the Jaccard Index. The results revealed the presence of considerable variability in the collection. Analysis of the genetic dissimilarity matrix revealed that the most dissimilar genotypes were Rupestris du Lot and Vitis rotundifolia because they were the most genetically distant (0.5972). The most similar were genotypes 31 (unidentified) and Rupestris du lot, which showed zero distance, confirming the results of field observations. A duplicate was confirmed, consistent with field observations, and a short distance was found between the variety 'Italy' and its mutation, 'Ruby'. The grouping methods used were somewhat concordant.

Selecting black-spot resistant papaya genotypes derived from backcrossing and hybrids

Papaya crop is important to Brazilian agribusiness. However, the expansion of papaya cultivation in the country is affected by the absence of commercial cultivars presenting good disease resistance. The black-spot caused by the fungus Asperisporium caricae is the most damaging foliar disease affecting Brazilian papaya crops. The use of genetically resistant cultivars is a promising strategy to reduce the dependence of papaya crops on fungicides. A field split-plot experiment was carried out in the municipality of Linhares, Espírito Santo State, and included 20 hybrids derived from the cross between 14 superior lines and four elite genotypes ('SS72/12', 'SEKATI', 'JS/12' and '41/7'), two commercial cultivars ('Golden' and 'Tainung 01'), and the superior line '36/7', which were evaluated for resistance to black-spot in the fruits and leaves. The treatments were arranged in a randomized block design with six repetitions of three plants per plot. The incidence and severity of black spot in the fruits and leaves were evaluated at three different times in the 2015-2016 crop season. Lines 4, 9, 21, and the parent SEKATI were notable for their capacity to reduce disease severity in the leaves and fruits. Lines 1, 2, 9, 16, and 19, and the parents 'SEKATI' and 'SS-72/12' had reduced disease incidence in their fruits. The most resistant hybrids 'SS-72/12 X 4', 'SS-72/12 X 6', 'SEKATI X 1', 'SEKATI X 2', 'SEKATI X 6', 'SEKATI X 9', and 'SEKATI X 20' presented negative heterosis values for improved black-spot resistance. The current study allowed the selection of black-spot resistant genotypes and hybrids, which presented a significantly reduced disease index in the field.

Immobility reactions under threat: A contribution to human defensive cascade and PTSD

Violence exacts a burden on public health. Gun violence is a major trigger for motor defensive reactions in humans and post-traumatic stress disorder (PTSD) is its main psychiatric sequela. However, studies of the human defensive cascade, especially the motor reactions, are at an early stage. This review focuses on studies that employ stabilometry, a methodology that assesses whole body motor reactions, to address defensive behaviors to violence-related threats. Special attention is given to three reactions: "attentive immobility", "immobility under attack" and "tonic immobility", with emphasis on the latter - a peritraumatic reaction which has been strongly associated with the severity of PTSD. These reactions are characterized by reduced body sway and bradycardia, except tonic immobility that presents robust tachycardia. The advances made by investigations into the immobility reactions of the human defensive cascade contribute to helping to bridge the gap between human and non-human species. Furthermore, progresses in basic research to objectively monitor motor defensive reactions under threat can help to develop a dimensional, trans-diagnostic approach to PTSD.

Proposal of a super trait for the optimum selection of popcorn progenies based on path analysis

A challenge faced by popcorn breeding programs is the existence of a negative correlation between the two main traits, popping expansion and yield, which hinders simultaneous gains. The objective of this study was to investigate the use of a new variable or super trait, which favors the reliable selection of superior progenies. The super trait 'expanded popcorn volume per hectare' was introduced in the evaluation of 200 full-sib families of the eighth recurrent intrapopulation selection cycle, which were arranged in randomized blocks with three replicates in two environments. Although the inability to obtain simultaneous gains through selection via popping expansion or yield was confirmed, the super trait was positively associated with both yield and popping expansion, allowing simultaneous gains via indirect selection using 'expanded popcorn volume per hectare' as the main trait. This approach is recommended because this super trait can be used in breeding programs to optimize selective gains for the crop.

The Perception of Aversiveness of Surgical Procedure Pictures Is Modulated by Personal/Occupational Relevance

It is well established that emotions are organized around two motivational systems: the defensive and the appetitive. Individual differences are relevant factors in emotional reactions, making them more flexible and less stereotyped. There is evidence that health professionals have lower emotional reactivity when viewing scenes of situations involving pain. The objective of this study was to investigate whether the rating of pictures of surgical procedure depends on their personal/occupational relevance. Fifty-two female Nursing (health discipline) and forty-eight Social Work (social science discipline) students participated in the experiment, which consisted of the presentation of 105 images of different categories (e.g., neutral, food), including 25 images of surgical procedure. Volunteers judged each picture according to its valence (pleasantness) and arousal using the Self-Assessment Manikin scale (dimensional approach). Additionally, the participants chose the word that best described what they felt while viewing each image (discrete emotion perspective). The average valence score for surgical procedure pictures for the Nursing group (M = 4.57; SD = 1.02) was higher than the score for the Social Work group (M = 3.31; SD = 1.05), indicating that Nursing students classified those images as less unpleasant than the Social Work students did. Additionally, the majority of Nursing students (65.4%) chose "neutral" as the word that best described what they felt while viewing the pictures. In the Social Work group, disgust (54.2%) was the emotion that was most frequently chosen. The evaluation of emotional stimuli differed according to the groups' personal/occupational relevance: Nursing students judged pictures of surgical procedure as less unpleasant than the Social Work students did, possibly reflecting an emotional regulation skill or some type of habituation that is critically relevant to their future professional work.

Coconut genome size determined by flow cytometry: Tall versus Dwarf types

Coconuts (Cocos nucifera L.) are tropical palm trees that are classified into Tall and Dwarf types based on height, and both types are diploid (2n = 2x = 32 chromosomes). The reproduction mode is autogamous for Dwarf types and allogamous for Tall types. One hypothesis for the origin of the Dwarf coconut suggests that it is a Tall variant that resulted from either mutation or inbreeding, and differences in genome size between the two types would support this hypothesis. In this study, we estimated the genome sizes of 14 coconut accessions (eight Tall and six Dwarf types) using flow cytometry. Nuclei were extracted from leaf discs and stained with propidium iodide, and Pisum sativum (2C = 9.07 pg DNA) was used as an internal standard. Histograms with good resolution and low coefficients of variation (2.5 to 3.2%) were obtained. The 2C DNA content ranged from 5.72 to 5.48 pg for Tall accessions and from 5.58 to 5.52 pg for Dwarf accessions. The mean genome sizes for Tall and Dwarf specimens were 5.59 and 5.55 pg, respectively. Among all accessions, Rennel Island Tall had the highest mean DNA content (5.72 pg), whereas West African Tall had the lowest (5.48 pg). The mean coconut genome size (2C = 5.57 pg, corresponding to 2723.73 Mbp/haploid set) was classified as small. Only small differences in genome size existed among the coconut accessions, suggesting that the Dwarf type did not evolve from the Tall type.

Controls and forecasts of nitrate yields in forested watersheds: A view over mainland Portugal

A study on nitrate yields was conducted in forested watersheds of mainland Portugal. The prime goal was to rank parameters in descending order of their contribution to the export of nitrate towards streams and lakes. To attain the goal, variables like soil loss, rainfall intensity, topography, soil type, forest composition and environmental disturbances such as hardwood harvesting or wildfires were organized in a conceptual yield model. Because some parameters were potentially collinear, a robust multivariate statistical technique was selected to execute the conceptual model and perform the aforementioned ranking, namely Partial Least Squares (PLS) regression. This technique was tested with a sample of 60 forested watersheds (>70% of forest occupation), being subject to a double-validation process to ensure prediction capability. According to final regression coefficients, soil erosion seems to regulate nitrate distribution across the basins, because soil loss and type, rainfall intensity and topography explained around 60% of nitrate yield variance. The major importance of erosion is followed by a moderate role of biochemical processes such as nitrification or nutrient uptake, which accounted for approximately 15% of nitrate yield variance. In this case, deciduous forests and scrubland seem to behave as net sinks of nitrate while coniferous and mixed forests seem to act dually, as net sources or sinks. The least important parameters are the environmental disturbances, explaining no more than 5% of nitrate yield variance. The results of PLS regression were coupled in a scenario analysis with measures designed to protect soil from erosion and surface water from eutrophication. These interventions are to be implemented until 2045, according to regional plans of forest management. Considering the key role of erosion in explaining nitrate dynamics across the catchments, it was not surprising to verify that soil protection measures may reduce nitrate yields by some 35% of their current values.

EEG correlates of the severity of posttraumatic stress symptoms: A systematic review of the dimensional PTSD literature

BACKGROUND

Considering the Research Domain Criteria (RDoC) framework, it is crucial to investigate posttraumatic stress disorder (PTSD) as a spectrum that ranges from normal to pathological. This dimensional approach is especially important to aid early PTSD detection and to guide better treatment options. In recent years, electroencephalography (EEG) has been used to investigate PTSD; however, reviews regarding EEG data related to PTSD are lacking, especially considering the dimensional approach. This systematic review examined the literature regarding EEG alterations in trauma-exposed people with posttraumatic stress symptoms (PTSS) to identify putative EEG biomarkers of PTSS severity.

METHOD

A systematic review of EEG studies of trauma-exposed participants with PTSS that reported dimensional analyses (e.g., correlations or regressions) between PTSS and EEG measures was performed.

RESULTS

The literature search yielded 1178 references, of which 34 studies were eligible for inclusion. Despite variability among the reviewed studies, the PTSS severity was often associated with P2, P3-family event-related potentials (ERPs) and alpha rhythms.

LIMITATIONS

The search was limited to articles published in English; no information about non-published studies or studies reported in other languages was obtained. Another limitation was the heterogeneity of studies, which made meta-analysis challenging.

CONCLUSIONS

EEG provides promising candidates to act as biomarkers, although further studies are required to confirm the findings. Thus, EEG, in addition to being cheaper and easier to implement than other central techniques, has the potential to reveal biomarkers of PTSS severity.

Water resources planning for a river basin with recurrent wildfires

Situated in the north of Portugal, the Beça River basin is subject to recurrent wildfires, which produce serious consequences on soil erosion and nutrient exports, namely by deteriorating the water quality in the basin. In the present study, the ECO Lab tool embedded in the Mike Hydro Basin software was used for the evaluation of river water quality, in particular the dissolved concentration of phosphorus in the period 1990-2013. The phosphorus concentrations are influenced by the burned area and the river flow discharge, but the hydrologic conditions prevail: in a wet year (2000, 16.3 km(2) of burned area) with an average flow of 16.4 m(3)·s(-1) the maximum phosphorus concentration was as low as 0.02 mg·L(-1), while in a dry year (2005, 24.4 km(2) of burned area) with an average flow of 2 m(3)·s(-1) the maximum concentration was as high as 0.57 mg·L(-1). Phosphorus concentrations in the water bodies exceeded the bounds of good ecological status in 2005 and between 2009 and 2012, water for human consumption in 2009 and water for multiple uses in 2010. The River Covas, a right margin tributary of Beça River, is the most appropriate stream as regards the use of water for human consumption, because it presents the biggest water potential with the best water quality. Since wildfires in the basin result essentially from natural causes and climate change forecasts indicate an increase in their frequency and intensity in the near future, forestry measures are proposed to include as a priority the conversion of stands of maritime pine in mixed stands of conifer and hardwood species.

Functional molecular markers (EST-SSR) in the full-sib reciprocal recurrent selection program of maize (Zea mays L.)

This study aimed to improve grain yield in the full-sib reciprocal recurrent selection program of maize from the North Fluminense State University. In the current phase of the program, the goal is to maintain, or even increase, the genetic variability within and among populations, in order to increase heterosis of the 13th cycle of reciprocal recurrent selection. Microsatellite expressed sequence tags (EST-SSRs) were used as a tool to assist the maximization step of genetic variability, targeting the functional genome. Eighty S1 progenies of the 13th recur-rent selection cycle, 40 from each population (CIMMYT and Piranão), were analyzed using 20 EST-SSR loci. Genetic diversity, observed heterozygosity, information content of polymorphism, and inbreeding co-efficient were estimated. Subsequently, analysis of genetic dissimilarity, molecular variance, and a graphical dispersion of genotypes were conducted. The number of alleles in the CIMMYT population ranged from 1 to 6, while in the Piranão population the range was from 2 to 8, with a mean of 3.65 and 4.35, respectively. As evidenced by the number of alleles, the Shannon index showed greater diversity for the Piranão population (1.04) in relation to the CIMMYT population (0.89). The genic SSR markers were effective in clustering genotypes into their respective populations before selection and an increase in the variation between populations after selection was observed. The results indicate that the study populations have expressive genetic diversity, which cor-responds to the functional genome, indicating that this strategy may contribute to genetic gain, especially in association with the grain yield of future hybrids.

Impacts of climate change and land-use scenarios on Margaritifera margaritifera, an environmental indicator and endangered species

In this study, we assess the impacts of future climate and land-use in the Beça River (northern Portugal) under different scenarios and how this will translate into the conservation status of the endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758). This species is currently present in several stretches of the Beça River that still hold adequate ecological conditions. However, the species is threatened by projected declines in precipitation for the 21st century, with implication on the river flows and water depths that might decrease below the species requisites. This situation could be especially critical during summer conditions since the ecological flows may not be assured and several river stretches may be converted into stagnant isolated pools. The habitat connectivity will also be affected with reverberating effects on the mobility of Salmo trutta, the host of M. margaritifera, with consequences in the reproduction and recruitment of pearl mussels. In addition, human-related threats mostly associated with the presence of dams and an predicted increases in wildfires in the future. While the presence of dams may decrease even further the connectivity and river flow, with wildfires the major threat will be related to the wash out of burned areas during storms, eventually causing the disappearance of the mussels, especially the juveniles. In view of future climate and land-use change scenarios, conservation strategies are proposed, including the negotiation of ecological flows with the dam promoters, the replanting of riparian vegetation along the water course and the reintroduction of native tree species throughout the catchment.

Efficiency of circulant diallels via mixed models in the selection of papaya genotypes resistant to foliar fungal diseases

Diallel crossing methods provide information regarding the performance of genitors between themselves and their hybrid combinations. However, with a large number of parents, the number of hybrid combinations that can be obtained and evaluated become limited. One option regarding the number of parents involved is the adoption of circulant diallels. However, information is lacking regarding diallel analysis using mixed models. This study aimed to evaluate the efficacy of the method of linear mixed models to estimate, for variable resistance to foliar fungal diseases, components of general and specific combining ability in a circulant table with different s values. Subsequently, 50 diallels were simulated for each s value, and the correlations and estimates of the combining abilities of the different diallel combinations were analyzed. The circulant diallel method using mixed modeling was effective in the classification of genitors regarding their combining abilities relative to the complete diallels. The numbers of crosses in which each genitor(s) will compose the circulant diallel and the estimated heritability affect the combining ability estimates. With three crosses per parent, it is possible to obtain good concordance (correlation above 0.8) between the combining ability estimates.

Attentional disengagement is modulated by the offset of unpleasant pictures: a saccadic reaction time study

We studied the influence of passively viewing a picture on saccade latencies to peripheral targets. Thirty-two volunteers were instructed to look at a central picture, wait for the onset of a peripheral target, and execute a saccade toward it as quickly as possible - saccadic reaction time (SRT). The central picture (neutral or unpleasant) could be turned off simultaneously with target onset (the no-gap condition) or 200ms prior to target onset (the gap-200 condition). We found that saccade latencies were influenced by emotional valence and condition. In the no-gap condition, SRTs were longer after viewing unpleasant pictures. In the gap-200 condition, the pattern was reversed, and unpleasant pictures induced shorter SRTs in relation to neutral pictures. Furthermore, the influence of unpleasant pictures gradually decreased when images were re-exposed to the participants - affective habituation. The results are discussed in terms of attentional avoidance and disengagement from unpleasant emotional pictures.

The murine long-term multi-lineage renewal marrow stem cell is a cycling cell

Prevailing wisdom holds that hematopoietic stem cells (HSCs) are predominantly quiescent. Although HSC cycle status has long been the subject of scrutiny, virtually all marrow stem cell research has been based on studies of highly purified HSCs. Here we explored the cell cycle status of marrow stem cells in un-separated whole bone marrow (WBM). We show that a large number of long-term multi-lineage engraftable stem cells within WBM are in S/G2/M phase. Using bromodeoxyuridine, we show rapid transit through the cell cycle of a previously defined relatively dormant purified stem cell, the long-term HSC (LT-HSC; Lineage(-)/c-kit(+)/Sca-1(+)/Flk-2(-)). Actively cycling marrow stem cells have continually changing phenotype with cell cycle transit, likely rendering them difficult to purify to homogeneity. Indeed, as WBM contains actively cycling stem cells, and highly purified stem cells engraft predominantly while quiescent, it follows that the population of cycling marrow stem cells within WBM are lost during purification. Our studies indicate that both the discarded lineage-positive and lineage-negative marrow cells in a stem cell separation contain cycling stem cells. We propose that future work should encompass this larger population of cycling stem cells that is poorly represented in current studies solely focused on purified stem cell populations.

Use of microsatellite markers in molecular analysis of segregating populations of papaya (Carica papaya L.) derived from backcrossing

Brazil is the world leader in papaya production. However, only a small number of cultivars are registered for commercial planting, mainly owing to delays in obtaining cultivars and the high costs of the field phase of breeding programs. These costs can be reduced when molecular tools are combined with conventional breeding methods. In the present study, we conducted a molecular analysis of a self-fertilized population of a first backcrossing generation of BC1S1 papaya plants via microsatellite markers both to monitor the level of homozygosity and the gene/allele transfer that confers the Golden trait (fruit color) and to assess the parental genomic proportion in the genotypes studied. Based on the analysis of 20 polymorphic microsatellite loci, 19 genotypes with the Golden trait belonging to BC1S1 were evaluated in addition to the parental genotypes. Genetic distance was estimated through weighted index. The genotypes were then grouped using the hierarchical nearest neighbor method, and the analysis of principal coordinates was used to measure the proportion of parental genomes in the segregating genotypes. The mean value of the inbreeding coefficient was 0.36. The analysis of the principal coordinates revealed that on average, 64% of the recurrent parent genome was present in the population. Together, the analyses allowed the selection of 3 individuals for the next backcross cycle (33BC1S1-18, 34BC1S1-16, and 37BC1S1-10). These individuals had a higher proportion of the recurrent parent and were grouped close to the recurrent parent in the cluster analysis.

The acute effects of strength, endurance and concurrent exercises on the Akt/mTOR/p70(S6K1) and AMPK signaling pathway responses in rat skeletal muscle

The activation of competing intracellular pathways has been proposed to explain the reduced training adaptations after concurrent strength and endurance exercises (CE). The present study investigated the acute effects of CE, strength exercises (SE), and endurance exercises (EE) on phosphorylated/total ratios of selected AMPK and Akt/mTOR/p70^S6K1 pathway proteins in rats. Six animals per exercise group were killed immediately (0 h) and 2 h after each exercise mode. In addition, 6 animals in a non-exercised condition (NE) were killed on the same day and under the same conditions. The levels of AMPK, phospho-Thr¹⁷²AMPK (p-AMPK), Akt, phospho-Ser⁴⁷³Akt (p-Akt), p70^S6K1, phospho-Thr³⁸⁹-p70^S6K1 (p-p70^S6K1), mTOR, phospho-Ser²⁴⁴⁸mTOR (p-mTOR), and phospho-Thr¹⁴⁶²-TSC2 (p-TSC2) expression were evaluated by immunoblotting in total plantaris muscle extracts. The only significant difference detected was an increase (i.e., 87%) in Akt phosphorylated/total ratio in the CE group 2 h after exercise compared to the NE group (P = 0.002). There were no changes in AMPK, TSC2, mTOR, or p70^S6K1 ratios when the exercise modes were compared to the NE condition (P ≥ 0.05). In conclusion, our data suggest that low-intensity and low-volume CE might not blunt the training-induced adaptations, since it did not activate competing intracellular pathways in an acute bout of strength and endurance exercises in rat skeletal muscle.

Construction of an RFLP map in sorghum and comparative mapping in maize

An F2 population derived from a cross between Sorghum bicolor ssp. bicolor ('CK60') and Sorghum bicolor ssp. drummondii ('PI229828') was used to develop an RFLP genetic linkage map of sorghum. The map consists of 201 loci distributed among 10 linkage groups covering a map distance of 1530 cM, with an average 8 cM between adjacent loci. Maize genomic probes (52), maize cDNA probes (124), and sorghum genomic probes (10) were used to define the loci (55, 136, and 10, respectively). Ninety-five percent of the loci fit expected segregation ratios. The loci with distorted segregation ratios were confined almost exclusively to a region of one linkage group. Comparison of sorghum and maize maps indicated high correspondence between the two genomes in terms of loci order and genetic distance. Many loci linked in maize (45 of 55) were also linked in sorghum. Instances of both conserved and rearranged locus orders were detected.

Full-sib reciprocal recurrent selection in the maize populations Cimmyt and Piranão

We estimated the genetic gains of the 12th cycle of reciprocal recurrent selection for maize traits of agronomic interest. We used 23 ISSR molecular markers in an attempt to maximize genetic variability among and within populations based on selection of S(1) progenies. To this end, 138 full-sib families were evaluated in a randomized block design in two environments (the municipalities of Campos dos Goytacazes and Itaocara, in the State of Rio de Janeiro, Brazil), with replications within sets. Direct selection for grain yield was used for the selection of the families. To assess genetic diversity among and within populations, we examined plants produced from part of the S(1s) seeds from the parents that originated the 42 full-sib families that were selected from the agronomic traits. Direct selection for grain yield provided good gains for the traits evaluated, with estimated improvement of -0.87 days for days to flowering, 0.35 plants, 1.79 ears per plot, 0.58 g per 100-grain weight, 308.21 g ear weight per plot, and 261.83 kg/ha grain yield. Application of molecular markers at the stage of superior progeny selection led to increased genetic distance among populations, which is a very important factor for utilization of heterosis and providing greater longevity to the reciprocal recurrent selection program.

Multivariate analysis to determine the genetic distance among backcross papaya (Carica papaya) progenies

Morpho-agronomic and molecular (RAPD and ISSR markers) data were used to evaluate genetic distances between papaya backcross progenies in order to help identify agronomically superior genotypes. Thirty-two papaya progenies were evaluated based on 15 morpho-agronomic characteristics, 20 ISSR and 19 RAPD primers. Manhattan, Jaccard and Gower distances were used to estimate differences based on continuous and binary data and combined analyses, respectively. Except for production, there were significant differences in the continuous variables among the genotypes. The molecular analysis revealed 193 dominant markers (ISSR and RAPD), being 53 polymorphic loci. Among the various clusters that were generated, the one based on a combined analysis of morpho-agronomic and molecular data gave the highest cophenetic correlation (0.72) compared to individual analysis, consistently allocating the progenies into six groups. We found that the Gower algorithm was more coherent in the discrimination of the genotypes, demonstrating that a combination of molecular and agronomic data is valuable for studies of genetic dissimilarity in papaya.

Affiliative stimuli as primers to prosocial predispositions

Affiliative stimuli are pleasant and highly biologically relevant. Affiliative cues are thought to elicit a prosocial predisposition. Here affiliative and neutral pictures were exposed prior to a reaction time task which consisted in responding to a visual target. Half the participants responded with finger-flexion, a movement frequently involved in prosocial activities. The other half responded with finger extension, a less prosocially compatible movement. Results showed that under the exposure to affiliative pictures, as compared to neutral ones, participants who used finger flexion were faster, while those using finger extension were slower. Performance benefits to the task, when flexing the finger, together with performance costs, when extending it, indicate the relevance of movement compatibility to the context. These findings put forward a possible link between affiliative primers and motor preparation to facilitate a repertoire of movements related to prosocial predispositions including finger flexion.

Use of molecular markers in reciprocal recurrent selection of maize increases heterosis effects

We examined the effect of incorporation of molecular markers on variability between and within populations in order to maximize heterotic effects and longevity of a maize reciprocal recurrent selection program. Molecular variability was quantified by inter-simple sequence repeat (ISSR) markers between and within the maize populations Cimmyt and Piranão in the 10th cycle of a reciprocal recurrent selection program. Forty-two S(1) progenies of each population were analyzed, these being families of full-sibs selected according to their agronomic traits. Thirteen primers were selected, which produced 140 bands; 114 of them were polymorphic and 26 monomorphic. Based on UPGMA grouping analysis and by genetic distances, it was possible to identify "contaminant" progenies. These progenies belong to the Piranão or Cimmyt groups, but cluster in the opposite heterotic group. Identification of "contaminant" progenies is relevant for selection, because, besides identifying genotypes that should be eliminated at the recombination stage, it allows increased heterosis expression in crosses between more genetically distinct individuals. After the elimination of the "contaminant" progenies and those that were allocated between the heterotic groups, a new statistical analysis was carried out, which demonstrated increased genetic distances between the populations. It was concluded that the application of molecular markers in reciprocal recurrent selection programs allows the optimization of the monitoring of genetic variability within and between populations, favoring recombination between more distant progenies, besides ensuring increased longevity of the reciprocal recurrent selection program.

RAPD and ISSR markers in the evaluation of genetic divergence among accessions of elephant grass

Considering the expected genetic variability of elephant grass (Pennisetum purpureum), due to its cultivation in different continents, we characterized and estimated the genetic divergences between 46 accessions of elephant grass with different edaphoclimatic adaptations, using RAPD and ISSR markers. We evaluated, comparatively, the consistency of the information achieved with these markers. Twenty-six RAPD and 25 ISSR primers were employed. The RAPD markers produced 185 bands, 72% of which were polymorphic, with a mean of 5.11 polymorphic bands per primer. The 25 ISSR starters produced 216 bands; 76% were polymorphic, with a mean of 6.56 polymorphic bands per primer. The correlation between the genetic distances achieved by the RAPD and ISSR markers was 0.76, which is highly significant by the Mantel test. Based on UPGMA grouping, considering the point of sudden change, five and six groups were formed for the data from the RAPD and ISSR markers, respectively. These markers provided partially concordant groups, indicating that these techniques can provide consistent information and consequently could be used in studies of genetic diversity among accessions.

Genetic characterization of papaya plants (Carica papaya L.) derived from the first backcross generation

The limited number of papaya varieties available reflects the narrow genetic base of this species. The use of backcrossing as a breeding strategy can promote increases in variability, besides allowing targeted improvements. Procedures that combine the use of molecular markers and backcrossing permit a reduction of the time required for introgression of genes of interest and appropriate recovery of the recurrent genome. We used microsatellite markers to characterize the effect of first-generation backcrosses of three papaya progeny, by monitoring the level of homozygosity and the parental genomic ratio. The homozygosity level in the population ranged from 74 to 94%, with a mean of 85% for the three progenies (52-08, 52-29 and 52-34). The high level of inbreeding found among these genotypes increases the expectation of finding more than 95% fixed loci in the next generation of self-fertilization of superior genotypes. The mean proportion of the recurrent parent genome found in first-generation backcross progeny was 50.1%; 52-34 had a larger genomic region in common with the recurrent genitor and the lowest level of homozygosity. The progeny 52-08 was genetically closest to the donor genitor, and it also had the highest level of homozygosity. We found that linking conventional procedures and molecular markers contributed to an increase in the efficiency of the breeding program.

Optimizing the efficiency of the touchdown technique for detecting inter-simple sequence repeat markers in corn (Zea mays)

We evaluated the efficiency of the touchdown method to determine the ideal PCR conditions for distinct inter-simple sequence repeat primers for processing DNA from common corn, popcorn, sweet corn, and a Tripsacum-maize hybrid. Genomic DNA was extracted from eight accessions of corn: two of the dent type, one Tripsacum-maize hybrid, one sweet corn, one flint-type corn, and three popcorn. Fifteen inter-simple sequence repeat primers were used: (CT)(8)RC, (CT)(8)TG, (GA)(8)T, (GA)(8)YC, (CTC)(5)RC, (GTC)(6), (GA)(6)CC, (GT)(6)CC, (CAC)(3)GC, (AG)(8)YT, (AC)(8)T, (AC)(8)YG, (CT)(8)RG, (GGAT)(3)GA, and (GAA)(6)AA. The annealing temperature and the melting temperature for each primer were estimated using a formula for RW Genes products, or we used the temperatures indicated by the manufacturer (Invitrogen). The touchdown method was then applied to each primer, varying the number of final cycles (10 or 12) and the decrease in temperature (0.5 degrees or 1.0 degrees C intervals). The gels were compared, considering the revelation quality, band sharpness and the number of bands visualized. The touchdown-PCR method was more efficient for band amplification for most of the primers, especially at higher annealing temperatures. This type of system is useful for reducing the resources, time and effort needed for optimizing temperature conditions for a group of representative primers.

Fact or fiction? An event-related potential study of implicit emotion regulation

Emotion regulation can be achieved through a number of processes. Previous studies have investigated this issue by encouraging individuals to voluntarily change how they think about a situation in order to decrease its emotional impact. However, little is known about automatic regulation processes. The goal of the present study was to investigate whether an "implicit reappraisal strategy" would modulate the Late Positive Potential (LPP) associated to affective picture viewing. Unpleasant pictures, presented as distractors, were shown in two contexts in which a prior description presented them as taken from either movie scenes (fictitious) or real scenes. Results showed that the interference produced by unpleasant pictures under the real context, indexed by reaction time and LPP amplitude, was attenuated under the fictitious context. These results provide evidence for implicit down-regulation of the stimulus relevance during an inattention condition.