Drosophila nasuta (Diptera, Drosophilidae) in Brazil: a decade of invasion and occupation of more than half of the country.

As a result of human activities and natural dispersal, exotic species can be brought to new areas, where they become established and spread, becoming invaders. These species are responsible for the loss of biodiversity and cause ecosystemic harm throughout the world. In this paper, we report the rapid, broad geographic expansion of the invasive fly Drosophila nasuta in Brazil. An 84% increase was found in its area of occupation in the country compared to previous studies. The present data reveal its arrival to the Pantanal wetlands in a location more than one thousand kilometers from the closest previous record in the Cerrado biome. We present the first record of D. nasuta in the Atlantic Forest in the states of Paraíba and Bahia. We report its introduction in the Amazon Forest in the state of Amazonas approximately 700 kilometers from previous records. The relative abundance of D. nasuta in this biome increased fivefold in comparison to a previous study. In the first decade of invasion in Brazil, D. nasuta has already colonized more than half of the country. The present data reveal its invasive potential and underscore the importance of following up the possible negative effects of this biological invasion.

The Covid-19 pandemic reinforces the need for sustainable health planning.

The 2030 Agenda for Sustainable Development highlighted the growing attention to the adequacy of health planning models to sustainable development. A re-reading of the results of a round table debate on "sustainable planning", which took place at the 5th National Congress of Tropical Medicine (Portugal, 2019) under a participant observation strategy, framed by the findings of a "synthesis of better evidence" literature review and cross-referenced with the reflections of different authors and experts about the momentum created by the COVID-19 pandemic, underlined the challenges to sustainable health planning that have emerged and are projected beyond the current pandemic context. Variable perceptions of the term "sustainable health development", leading to the potential loss of their relevance in guiding the elaboration of policies and strategic plans, and the potential higher effectiveness of the participatory approaches of health planning in achieving sustainable health were highlighted in the debate and literature, in general and in public health emergency contexts. Those results gained new relevance during the current COVID-19 pandemic, bringing back to the forefront a reflection of the inadequate planning framework that has usually been used to understand and respond to global health challenges, despite the already existing experience, evidence and support instruments.

Dependency Factors in Evidence Theory: An Analysis in an Information Fusion Scenario Applied in Adverse Drug Reactions.

Multisensor information fusion brings challenges such as data heterogeneity, source precision, and the merger of uncertainties that impact the quality of classifiers. A widely used approach for classification problems in a multisensor context is the Dempster-Shafer Theory. This approach considers the beliefs attached to each source to consolidate the information concerning the hypotheses to come up with a classifier with higher precision. Nevertheless, the fundamental premise for using the approach is that sources are independent and that the classification hypotheses are mutually exclusive. Some approaches ignore this premise, which can lead to unreliable results. There are other approaches, based on statistics and machine learning techniques, that expurgate the dependencies or include a discount factor to mitigate the risk of dependencies. We propose a novel approach based on Bayesian net, Pearson's test, and linear regression to adjust the beliefs for more accurate data fusion, mitigating possible correlations or dependencies. We tested our approach by applying it in the domain of adverse drug reactions discovery. The experiment used nine databases containing data from 50,000 active patients of a Brazilian cancer hospital, including clinical exams, laboratory tests, physicians' anamnesis, medical prescriptions, clinical notes, medicine leaflets packages, international classification of disease, and sickness diagnosis models. This study had the hospital's ethical committee approval. A statistically significant improvement in the precision and recall of the results was obtained compared with existing approaches. The results obtained show that the credibility index proposed by the model significantly increases the quality of the evidence generated with the algorithm Random Forest. A benchmark was performed between three datasets, incremented gradually with attributes of a credibility index, obtaining a precision of 92%. Finally, we performed a benchmark with a public base of heart disease, achieving good results.

Health literacy of patients on oral anticoagulation treatment- individual and social determinants and effect on health and treatment outcomes.

BACKGROUND: Assessment health literacy in people with cardiovascular health problems would facilitate the development of appropriate health strategies for the care and reduction of complications associated with oral anticoagulation therapy. AIM: To evaluate the relationship between health literacy and health and treatment outcomes (concordance with oral anticoagulants, Normalized Ratio control and occurrence of complications) in patients with cardiovascular pathology. METHODS: Observational, analytic and cross-sectional study carried out on 252 patients with cardiovascular pathology (atrial fibrillation, flutter or valve prosthesis), aged 50-85 years, accessing primary care services in Valencia (Spain) in 2018-2019. Variables referring to anticoagulant treatment with vitamin K antagonists (years of treatment, adequate control, polypharmacy and occurrence of complications, among others) and health literacy (Health Literacy Questionnaire) were analysed. RESULTS: All dimensions of health literacy were significantly related to the level of education (p < 0.02), social class (p < 0.02), an adequate control of acenocoumarol (p < 0.001), frequentation of health services (p < 0.001), information by patients to health professionals about anticoagulant treatment (p < 0.03), emergency care visits (p < 0.001) and unscheduled hospital admissions (p < 0.001). CONCLUSION: Health literacy has a relevant influence on the adequate self-management of anticoagulation treatment and the frequency of complications. The different dimensions that comprise health literacy play an important role, but the "social health support" dimension seems to be essential for such optimal self-management. TRIAL REGISTRATION: ACC-ACE-2016-01. Registration date: December 2015.

The cost structure of influencers' posts: the risk of losing followers.

This paper presents an exploratory study of the posting behavior of digital influencers in social participation platforms. As there are different platforms of social participation, we present a taxonomy to unify the different classifications and delimit the scope of our work. Influencers could produce a positive externality of increasing participation by suggesting social causes and government actions they believe in. However, influencers tend to restrict their posts to the domain subject they became popular for. Our goal is to identify the cost structure of posting behavior of influencers, from the desire to post to the actual act of posting. The findings indicate the two key factors influencers consider when posting are (a) the risk of losing followers and (b) the effort required to verify the information. On the other hand, followers indicate they like it when influencers voice their opinion on social causes. These findings are anchored on social influence theory. We also found different factors that motivate/demotivate people to post on social media. We noticed that the factors that will motivate a user to post can either be aroused in him (i.e., already internalized in the person) or can be "planted" in the person (i.e., from outside).

Tuberculosis care for migrant patients in Portugal: a mixed methods study with primary healthcare providers.

BACKGROUND: Tuberculosis (TB) is still a major global health problem. The increasing number of cases observed among foreign-born populations contrasts with the decreasing trends observed in later years in some high-income countries. Healthcare providers are key interveners in the control of TB and HIV-TB infections. In this study, we aimed to explore the perspectives of healthcare providers working in primary care in Portugal about the provision of TB care for migrant patients with TB or HIV-TB co-infection. METHODS: We applied a mixed-methods approach using an online survey and semi-structured interviews with primary healthcare providers. A total of 120 Portuguese healthcare providers participated in the survey, and 17 were interviewed. Survey and interview data were analysed applying descriptive statistics and thematic analysis, respectively. RESULTS: Migrants' lack of knowledge on TB disease and its symptoms was the main reason for advanced-stage presentation of cases. Their high mobility and social isolation affect adherence to treatment. The providers also listed several barriers to migrants' access and use of TB care. The most frequently referred were limited socioeconomic resources, complex bureaucracy at the point of access and registration for healthcare services, especially for undocumented migrants, and obstacles for social protection. Providers also advocated more training initiatives on migrants' health, social and cultural contexts, on HIV and TB integrated care, and on TB scientific update for general practitioners and nurses working at primary healthcare centres. CONCLUSIONS: Future efforts should provide measures to overcome social, economic and administrative obstacles to care for TB-infected migrants, and promote regular training initiatives for national healthcare providers in order to raise awareness and facilitate better care to culturally diverse populations with TB.

Relation between health literacy, self-care and adherence to treatment with oral anticoagulants in adults: a narrative systematic review.

BACKGROUND: Oral anticoagulants (OAC) are widely used in patients with cardiovascular diseases. However, for optimal OAC self-care patients must have skills, among which health literacy (HL) is highlighted. We aimed to describe the relation between HL and self-care in cardiovascular patients on OAC treatment. METHODS: Electronic searches were carried out in the PubMed, Scopus, Embase, CINAHL, Web of Science, Cochrane Library, SciELO, IME-Biomedicina, CUIDEN Plus and LILACS databases, limited to Spanish and English language and between January 2000-December 2016. Papers reported on adults older than 18 years, taking OAC by themselves for at least three months. PRISMA guidelines were used for paper selection. RESULTS: We identified 142 articles and finally included 10; almost all of them about warfarin. Our results suggest that in patients taking OAC treatments there is a positive relationship between HL and the level of knowledge. In addition, a small percentage of participants on the selected papers recognized the side effects and complications associated with OAC treatment. Lower HL level was associated with greater knowledge deficits and less adherence to treatment. CONCLUSION: There is a paucity of research evaluating the effect of HL on diverse aspects of OAC treatments. There is a need to expand the evidence base regarding appropriate HL screening tools, determinants of adequate knowledge and optimal behaviours related to OAC self-management.

Validation of Comet assay in Oregon-R and Wild type strains of Drosophila melanogaster exposed to a natural radioactive environment in Brazilian semiarid region.

Natural radiation of geological origin is a common phenomenon in Brazil, a country where radioactive agents such as uranium may be often found. As an unstable atom, uranium undergoes radioactive decay with the generation of a series of decay by-products, including radon, which may be highly genotoxic and trigger several pathological processes, among which cancer. Because it is a gas, radon may move freely between cracks and gaps in the ground, seeping upwards into the buildings and in the environment. In this study, two Drosophila melanogaster Meigen (Diptera, Drosophilidae) strains called Oregon-R and Wild (collected in a non-radioactive environment) were exposed to atmospheric radiation in the Lajes Pintadas city, in the semiarid zone of northeastern Brazil. After six days of environmental exposure, the organisms presented genetic damage significantly higher than that of the negative control group. The genotoxic effects observed reinforce the findings of other studies carried out in the same region, which warn about the environmental risks related to natural radioactivity occurrence. The results also validate the use of the Comet assay in hemocytes of D. melanogaster as a sensitive test to detect genotoxicity caused by natural radiation, and the use of a recently collected D. melanogaster strain in the environmental of radon.

Anomaly detection based on sensor data in petroleum industry applications.

Anomaly detection is the problem of finding patterns in data that do not conform to an a priori expected behavior. This is related to the problem in which some samples are distant, in terms of a given metric, from the rest of the dataset, where these anomalous samples are indicated as outliers. Anomaly detection has recently attracted the attention of the research community, because of its relevance in real-world applications, like intrusion detection, fraud detection, fault detection and system health monitoring, among many others. Anomalies themselves can have a positive or negative nature, depending on their context and interpretation. However, in either case, it is important for decision makers to be able to detect them in order to take appropriate actions. The petroleum industry is one of the application contexts where these problems are present. The correct detection of such types of unusual information empowers the decision maker with the capacity to act on the system in order to correctly avoid, correct or react to the situations associated with them. In that application context, heavy extraction machines for pumping and generation operations, like turbomachines, are intensively monitored by hundreds of sensors each that send measurements with a high frequency for damage prevention. In this paper, we propose a combination of yet another segmentation algorithm (YASA), a novel fast and high quality segmentation algorithm, with a one-class support vector machine approach for efficient anomaly detection in turbomachines. The proposal is meant for dealing with the aforementioned task and to cope with the lack of labeled training data. As a result, we perform a series of empirical studies comparing our approach to other methods applied to benchmark problems and a real-life application related to oil platform turbomachinery anomaly detection.

Cytogenetic mapping of the Muller F element genes in Drosophila willistoni group.

Comparative genomics in Drosophila began in 1940, when Muller stated that the ancestral haploid karyotype of this genus is constituted by five acrocentric chromosomes and one dot chromosome, named A to F elements. In some species of the willistoni group such as Drosophila willistoni and D. insularis, the F element, instead of a dot chromosome, has been incorporated into the E element, forming chromosome III (E + F fusion). The aim of this study was to investigate the scope of the E + F fusion in the willistoni group, evaluating six other species. Fluorescent in situ hybridization was used to locate two genes of the F element previously studied-cubitus interruptus (ci) and eyeless (ey)-in species of the willistoni and bocainensis subgroups. Moreover, polytene chromosome photomaps corresponding to the F element (basal portion of chromosome III) were constructed for each species studied. In D. willistoni, D. paulistorum and D. equinoxialis, the ci gene was located in subSectction 78B and the ey gene in 78C. In D. tropicalis, ci was located in subSection 76B and ey in 76C. In species of the bocainensis subgroup, ci and ey were localized, respectively, at subsections 76B and 76C in D. nebulosa and D. capricorni, and 76A and 76C in D. fumipennis. Despite the differences in the subsection numbers, all species showed the same position for ci and ey. The results confirm the synteny of E + F fusion in willistoni and bocainensis subgroups, and allow estimating the occurrence of this event at 15 Mya, at least.

Richness and abundance of the cardini group of Drosophila (Diptera, Drosophilidae) in the Caatinga and Atlantic Forest biomes in northeastern Brazil.

Brazil has a high diversity of flies of the genus Drosophila, and part of this richness is represented by the cardini group. We analyzed the fluctuations in the richness and abundance of this group, in environments that had never previously been studied in the northeastern region of Brazil. Among the 28,204 drosophilids sampled, 1,294 belonged to the cardini group and were represented by D. polymorpha, D. cardini, D. neocardini and D. cardinoides. Occurrences of D. neocardini and D. cardinoides were registered for the first time in the Caatinga. In this biome, D. cardini stood out as having the highest abundance, and D. polymorpha was not observed. In the coastal Atlantic Forest, D. cardini was not registered, but D. polymorpha was found in all the localities investigated. Mangrove swamps were the environment with the lowest abundance and richness of the cardini group. The High-altitude Forest presented the highest richness of this group. We suggest that the high abundance of D. polymorpha in the High-altitude Forest and in the coastal Atlantic Forest may be a reflection of the historical relationship between these two environments.

Knowledge Level of ICU Nurses Regarding Nutritional Assessment of Critically Ill Patients: A Systematic Review.

BACKGROUND: Nutritional assessment on admission of critical patients is of vital importance to determine critical patients in whom there is a risk of malnutrition. Currently, it has been detected in most of the patients admitted to the Intensive Care Unit (ICU) that 60% of the daily calories are not achieved. Nurses play an essential role in the comprehensive assessment of the patient, including the nutritional area; however, significant deficits have been detected in some knowledge regarding Enteral Nutrition (EN). OBJECTIVE: We aim to determine the level of knowledge of nurses in the nutritional assessment of critically ill patients. METHODOLOGY: A systematic review of the scientific literature was conducted using the PRISMA statement. Between January 2017 and February 2023, articles were rescued from the electronic databases "Pubmed", "Scopus" and "The Cochrane Library", which analyzed the level of knowledge of ICU nurses regarding nutritional assessment. RESULTS: Most of the results found showed that nurses had deficient levels of knowledge in relation to nutritional assessment and practices. Interventions related to nutritional assessment were scarce, in contrast to those associated with the management of Nasogastric Tube (NGT) or patient positioning. CONCLUSIONS: The level of knowledge described was low or inadequate in relation to the care associated with the nutritional assessment of critically ill patients. The use of scales to assess the risk of malnutrition was not reported. This study was prospectively registered at PROSPERO on 25/10/2023 (insert date) with registration number CRD: 42023426924.

Bone loss in chronic hemiplegia: a longitudinal cohort study.

The purpose of this study was to evaluate hemiplegic stroke patients in terms of long-term changes in bone mineral density and related factors. We conducted a longitudinal cohort study, involving 57 first-stroke patients (40 males) with chronic hemiplegia (for more than 12mo), at a university rehabilitation center in the city of São Paulo, Brazil. Bone loss, body composition, lean mass, and fat mass were evaluated at 2 time points (mean interval, 16mo). Bone loss was significantly greater in paretic forearms than in nonparetic forearms (p=0.001) and in patients having suffered strokes more recently (p=0.015). We found no difference between paretic and nonparetic femurs. Femoral bone loss was significantly greater in patients using anticoagulants or anticonvulsants (p=0.025) and in those with greater spasticity (p=0.040), regardless of the time since stroke. Our results provide additional evidence that hemiplegic stroke patients have progressive bone loss and that such bone loss is more common in the arms than in the legs. Patients with poststroke hemiplegia should be densitometric monitored mainly in paretic arm and treated for bone loss, with attention to the determinants identified in this study.

Evaluation of the European Health Information Training Programme (EHITP): results from InfAct Joint Action.

BACKGROUND: The InfAct (Information for Action) is a Joint Action of the European Commission's 3rd Health Programme with the main goal to build an infrastructure of a health information system for a stronger European Union and to strengthen its core elements. The InfAct Joint Action was developed along 36 months and structured in 10 work packages. Portugal co-led the Work Package 6 (WP6) of this project, which included the development of the proposal of a flagship capacity building programme - the European Health Information Training Programme - and its evaluation. The evaluation objectives included: to evaluate the adequacy of the training programme to the health information needs in the European Member States; to identify possible changes regarding the participants selection process, the training activities and the pedagogical project; and to contribute to the understanding of the potential of the programme to add to available offers in learning on the topics of Public Health information, on the capacity building and behavioural changes in Public Health activities which can be attributed to the course, and of the potential of the programme to contribute to the alignment of health information criteria and procedures between the European Member States. METHODS: The evaluation process was developed using an observational descriptive study design using a mixed methodological approach with both document analysis and primary data collected by questionnaires and interviews analysis. Mixed quantitative and qualitative data collection methods and analysis were used. RESULTS: The proposal of the European Health Information Training Programme seemed adequate to the formative needs and capacities in line with the work performed by the InfAct project. In what concerns about its main thematic areas, it was also aligned with the areas identified in the previous formative needs and capacities mapping. The participants selection process proposed seemed, in general, adequate. The potential of the European Health Information Training Programme proposal to learning, capacity building and behavioral changes at work attributable to the course was considered positive, as well as the potential to the alignment of health information criteria and procedures between European Union Member States. DISCUSSION: In general, we found high consistency between the results obtained from data collected by the techniques used. However, different suggestions for improvement were outlined by the evaluation study population. CONCLUSIONS: The proposed European Health Information Training Programme was a dynamic, flexible, sustainable formative programme in health information and focused on reducing inequalities.

First Records of the Invading Species Drosophila Nasuta (Diptera: Drosophilidae) in the Amazon.

Invading species pose a growing threat to biodiversity, ecosystemic systems, regional economies, and public health. In recent decades, South America has received five exotic drosophilids species, some of which have invaded natural ecosystems and caused harm to agriculture. The most recent case is the Asian fly Drosophila nasuta Lamb. In the present study, we record D. nasuta in the Amazon, which is the largest and most biodiverse tropical rainforest in the world. Sampling of drosophilids was carried out between 2012 and 2017 in the Brazilian state of Pará. Drosophila nasuta was first detected on 1st July 2017, with 145 individuals of this species sampled among the 11,496 drosophilids caught. Although at low abundance, D. nasuta was recorded in forest fragments, anthropized fields, and urban environment. The records of the species occurred in the six municipalities of the state of Pará investigated at locations separated by approximately 700 km. In less than 10 years, D. nasuta has occupied approximately 2.5 million km2 in South America. The present findings assist in understanding the susceptibility of tropical forests to biological invasions.

Patients with seronegative rheumatoid arthritis have a different phenotype than seropositive patients: A clinical and ultrasound study.

Introduction: Rheumatoid arthritis (RA) is an inflammatory disease whose clinical phenotype largely depends on the presence of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). Seronegative RA appears to be a less severe disease, but this remains controversial. This study aimed to assess whether seronegative patients show a less severe disease than seropositive patients. Methods: A cross-sectional study was conducted on RA outpatients from a single center. Clinical activity scales, laboratory evaluations, and cardiovascular risk scores were assessed. Musculoskeletal ultrasound (US) examinations were performed. Results: One hundred and fourteen patients were enrolled. Eighty-five were seropositive (76% women) and 29 seronegative (93% women). Seropositive patients had a younger age at disease onset (43 ± 14 vs. 54 ± 11; p = 0.001) and used sulfasalazine (47 vs. 17%; p = 0.004) and glucocorticoids (36 vs. 10%; p = 0.007) more frequently. No differences in clinical activity scales and in 10-year cardiovascular risk were observed. Pathological US data were found more frequently in seropositive patients in the 2nd metacarpophalangeal (MCP) joint, both in grayscale (71 vs. 38%; p = 0.008) and in power Doppler (PD; 53 vs. 9%; p < 0.001); erosions (36 vs. 9%; p = 0.020) were also more frequent. We found greater severity of PD signals in the 2nd MCP and 3rd MCP joints of the seropositive patients, while synovitis severity was higher only in the 2nd MCP joints. The percentage of total joints with erosions (9 vs. 1%; p < 0.001) and 2nd MCP joints with erosions (25 vs. 7%; p < 0.001) was higher in seropositive patients. Conclusion: RA patients show a differentiated phenotype according to their ACPA and RF status. In seronegative patients, RA begins later in life and has a lower requirement for antirheumatic therapies. On US evaluation, seropositive patients show more joint damage, especially in MCP joints. Despite this, long-term cardiovascular risk is similar among RA patients, regardless of their RF and ACPA status.

Seroprevalence of SARS-CoV-2 Infection in Portugal in May-July 2020: Results of the First National Serological Survey (ISNCOVID-19).

INTRODUCTION: The aim of this study was to estimate and describe the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies (immunoglobulin M and/or immunoglobulin G) in Portugal in May-July 2020. MATERIAL AND METHODS: A cross-sectional seroepidemiological survey was developed after the peak of the first epidemic wave on a sample of 2301 Portuguese residents, aged 1 year or older. Survey sample was selected using a two-stage stratified non-probability sampling design (quota sampling). SARS-CoV-2 immunoglobulin M and immunoglobulin G antibodies were measured in serum samples by enzyme-linked immunosorbent assay. Seroprevalence estimates of immunoglobulin M and/or immunoglobulin G and 95% confidence intervals were stratified by sex, age group, health region and education. RESULTS: Overall, seroprevalence was 2.9% (95% confidence interval: 2.0% - 4.2%). Higher prevalence rates were observed in male (4.1%, 95% confidence interval: 2.6% - 6.6%) and those with secondary education (6.4%, 95% confidence interval: 3.2% - 12.5%). Differences in seroprevalence by age group and region were not statistically significant. DISCUSSION: The estimated seroprevalence of SARS-CoV-2 was higher than the cumulative incidence reported by the National Surveillance System but far from necessary to reach herd immunity. CONCLUSION: Our results support limited extent of infection by SARS-CoV-2 in the study population possibly due to early lockdown measures implemented in Portugal and support the need to continue monitoring of SARS-CoV-2 seroprevalence in order to increase our knowledge about the evolution of the epidemic and to estimate the proportion of the susceptible population over time.

Introdução: Este estudo tem como objetivo estimar e descrever a prevalência dos anticorpos específicos (imunoglobulina M e/ou imunoglobulina G) contra o vírus da síndrome respiratória aguda grave do coronavírus 2 (SARS-CoV-2) em Portugal em maio-julho de 2020. Material e Métodos: Após o pico da primeira onda epidémica foi realizado um estudo seroepidemiológico transversal numa amostra de 2301 pessoas residentes em Portugal, com idade igual ou superior a um ano. A amostra foi selecionada recorrendo um desenho amostral não probabilístico bietápico estratificado por quotas. Procedeu-se à deteção de anticorpos específicos contra SARS-CoV-2 (imunoglobulina M e imunoglobulina G) em amostras de soro por ensaio de imunoabsorção enzimática. As estimativas da seroprevalência (imunoglobulina M e/ou imunoglobulina G) e os respetivos intervalos de confiança a 95% foram estratificadas por sexo, grupo etário, região de saúde e escolaridade. Resultados: A seroprevalência de anticorpos específicos imunoglobulina M e/ou imunoglobulina G foi de 2,9 % (intervalo de confiança a 95%: 2,0% ­ 4,2%), tendo sido mais elevada em homens (4,1%, intervalo de confiança a 95%: 2,6% - 6,6%) e nos indivíduos com ensino secundário (6,4%, intervalo de confiança a 95%: 3,2% - 12,5%). Não foram identificadas diferenças estatisticamente significativas na entre os grupos etários estudados, nem entre regiões. Discussão: A seroprevalência estimada foi superior à incidência cumulativa de infeção reportada pelo Sistema Nacional de Vigilância, embora longe dos valores necessários para atingir a imunidade de grupo. Conclusão: Os resultados indicam uma extensão limitada da infeção por SARS-CoV-2, na população estudada compatível com uma implementação precoce das medidas de confinamento em Portugal e suporta a necessidade de monitorização a seroprevalência de SARS-CoV-2 para conhecer a evolução da epidemia e proporção da população suscetível ao longo do tempo.

Invasion and Spreading of Drosophila nasuta (Diptera, Drosophilidae) in the Caatinga Biome, Brazil.

Biological invasions are one of the main causes of biodiversity loss, and it is essential to understand the pattern and rate of expansion of invasive species outside their native distribution. In this study, we documented the invasion of the Asian fruit fly, Drosophila nasuta Lamb, in the Caatinga, and measured its geographical distribution in this environment, which covers 11% of the Brazilian territory. We collected drosophilids in eight sites distributed in the north of the Caatinga (in the state of Ceará), in the south (in Bahia), in the east (in Pernambuco), and in the west (in Piauí), as well as in sites in the central area of the biome. Drosophila nasuta occurred in all areas and was one of the most frequently occurring species in half of the sampled sites. We observed greater abundance in areas with arboreal vegetation and a possible preference of this species for areas with higher annual rainfall in the Caatinga. Of all the biomes where D. nasuta is found in Brazil, the area occupied in the Caatinga is the largest documented to date. Our results show D. nasuta's success in invading the Caatinga and the vast area this species has colonized in this biome. The success of this invasion can be explained by the high fertility and short life cycle as well as by the ability of D. nasuta to use different trophic resources.