Negation recognition in clinical natural language processing using a combination of the NegEx algorithm and a convolutional neural network.

BACKGROUND: Important clinical information of patients is present in unstructured free-text fields of Electronic Health Records (EHRs). While this information can be extracted using clinical Natural Language Processing (cNLP), the recognition of negation modifiers represents an important challenge. A wide range of cNLP applications have been developed to detect the negation of medical entities in clinical free-text, however, effective solutions for languages other than English are scarce. This study aimed at developing a solution for negation recognition in Spanish EHRs based on a combination of a customized rule-based NegEx layer and a convolutional neural network (CNN). METHODS: Based on our previous experience in real world evidence (RWE) studies using information embedded in EHRs, negation recognition was simplified into a binary problem ('affirmative' vs. 'non-affirmative' class). For the NegEx layer, negation rules were obtained from a publicly available Spanish corpus and enriched with custom ones, whereby the CNN binary classifier was trained on EHRs annotated for clinical named entities (cNEs) and negation markers by medical doctors. RESULTS: The proposed negation recognition pipeline obtained precision, recall, and F1-score of 0.93, 0.94, and 0.94 for the 'affirmative' class, and 0.86, 0.84, and 0.85 for the 'non-affirmative' class, respectively. To validate the generalization capabilities of our methodology, we applied the negation recognition pipeline on EHRs (6,710 cNEs) from a different data source distribution than the training corpus and obtained consistent performance metrics for the 'affirmative' and 'non-affirmative' class (0.95, 0.97, and 0.96; and 0.90, 0.83, and 0.86 for precision, recall, and F1-score, respectively). Lastly, we evaluated the pipeline against two publicly available Spanish negation corpora, the IULA and NUBes, obtaining state-of-the-art metrics (1.00, 0.99, and 0.99; and 1.00, 0.93, and 0.96 for precision, recall, and F1-score, respectively). CONCLUSION: Negation recognition is a source of low precision in the retrieval of cNEs from EHRs' free-text. Combining a customized rule-based NegEx layer with a CNN binary classifier outperformed many other current approaches. RWE studies highly benefit from the correct recognition of negation as it reduces false positive detections of cNE which otherwise would undoubtedly reduce the credibility of cNLP systems.

Age represents the main driver of surgical decision making in patients candidate to radical cystectomy.

BACKGROUND AND OBJECTIVES: Age might influence the choice of surgical approach, type of urinary diversion (UD) and lymph node dissection (LND) in patients candidate to radical cystectomy (RC) for urothelial bladder cancer (UBC). Similarly, age may enhance surgical morbidity and worsen perioperative outcomes. We tested the impact of age (octogenarian vs. younger patients) on surgical decision making and peri- and postoperative outcomes of RC. METHODS: Non-metastatic muscle-invasive UBC patients treated with RC at 18 high-volume European institutions between 2006 and 2021 were identified and stratified according to age (≥80 vs. <80 years). Intraoperative Complications Assessment and Reporting with Universal Standards and European Association of Urology guidelines recommendations were accomplished in collection and reporting of, respectively, intraoperative and postoperative complications. Multivariable logistic regression models (MVA) tested the impact of age on outcomes of interest. Sensitivity analyses after 1:3 propensity score matching were performed. RESULTS: Of 1955 overall patients, 251 (13%) were ≥80-year-old. Minimally invasive RC was performed in 18% and 40% of octogenarian and younger patients, respectively (p < 0.001). UD without bowel manipulation (ureterocutaneostomy, UCS) was performed in 31% and 7% of octogenarian and younger patients (p < 0.001). LND was delivered to 81% and 93% of octogenarian and younger patients (p < 0.001). At MVA, age ≥80 years independently predicted open approach (odds ratio [OR]: 1.55), UCS (OR: 3.70), and omission of LND (OR: 0.41; all p ≤ 0.02). Compared to their younger counterparts, octogenarian patients experienced higher rates of intraoperative (8% vs. 4%, p = 0.04) but not of postoperative complications (64% vs. 61%, p = 0.07). At MVA, age ≥80 years was not an independent predictor of length of stay, intraoperative or postoperative transfusions and complications, and readmissions (all p values >0.1). These results were replicated in sensitivity analyses. CONCLUSIONS: Age ≥80 years does not independently portend worse surgical outcomes for RC. However, octogenarians are unreasonably more likely to receive open approach and UCS diversion, and less likely to undergo LND.

Shigella IpaA mediates actin bundling through diffusible vinculin oligomers with activation imprint.

Upon activation, vinculin reinforces cytoskeletal anchorage during cell adhesion. Activating ligands classically disrupt intramolecular interactions between the vinculin head and tail domains that bind to actin filaments. Here, we show that Shigella IpaA triggers major allosteric changes in the head domain, leading to vinculin homo-oligomerization. Through the cooperative binding of its three vinculin-binding sites (VBSs), IpaA induces a striking reorientation of the D1 and D2 head subdomains associated with vinculin oligomerization. IpaA thus acts as a catalyst producing vinculin clusters that bundle actin at a distance from the activation site and trigger the formation of highly stable adhesions resisting the action of actin relaxing drugs. Unlike canonical activation, vinculin homo-oligomers induced by IpaA appear to keep a persistent imprint of the activated state in addition to their bundling activity, accounting for stable cell adhesion independent of force transduction and relevant to bacterial invasion.

MindReader: Unsupervised Classification of Electroencephalographic Data.

Electroencephalogram (EEG) interpretation plays a critical role in the clinical assessment of neurological conditions, most notably epilepsy. However, EEG recordings are typically analyzed manually by highly specialized and heavily trained personnel. Moreover, the low rate of capturing abnormal events during the procedure makes interpretation time-consuming, resource-hungry, and overall an expensive process. Automatic detection offers the potential to improve the quality of patient care by shortening the time to diagnosis, managing big data and optimizing the allocation of human resources towards precision medicine. Here, we present MindReader, a novel unsupervised machine-learning method comprised of the interplay between an autoencoder network, a hidden Markov model (HMM), and a generative component: after dividing the signal into overlapping frames and performing a fast Fourier transform, MindReader trains an autoencoder neural network for dimensionality reduction and compact representation of different frequency patterns for each frame. Next, we processed the temporal patterns using a HMM, while a third and generative component hypothesized and characterized the different phases that were then fed back to the HMM. MindReader then automatically generates labels that the physician can interpret as pathological and non-pathological phases, thus effectively reducing the search space for trained personnel. We evaluated MindReader's predictive performance on 686 recordings, encompassing more than 980 h from the publicly available Physionet database. Compared to manual annotations, MindReader identified 197 of 198 epileptic events (99.45%), and is, as such, a highly sensitive method, which is a prerequisite for clinical use.

One-Year Surveillance of SARS-CoV-2 Virus in Natural and Drinking Water.

Although the SARS-CoV-2 virus has been detected in wastewater from several countries, monitoring its presence in other water matrices is still limited. This study aimed to evaluate the presence of this virus in natural and drinking water over one year of monitoring (2021). A survey of viral RNA was carried out by RT-qPCR in concentrated samples of surface water, groundwater, and drinking water from different regions of Portugal. SARS-CoV-2 RNA-quantified in genomic copies per liter (gc/L) of sampled water-was not detected in groundwater, but was detected and quantified in samples of surface water (two out of 43; 8035 and 23,757 gc/L) and in drinking water (one out of 43 samples; 7463 gc/L). The study also detected and quantified Norovirus RNA, intending to confirm the use of this enteric virus to assess variations in fecal matter throughout the sampling campaign. The samples positive for SARS-CoV-2 RNA also had the highest concentrations of Norovirus RNA-including the drinking water sample, which proved negative for fecal enteric bacteria (FIB). These results indicate that, to protect human health, it is advisable to continue monitoring these viruses, and noroviruses as fecal indicators (FI) as well-especially in low-flow water bodies that receive wastewater.

Gold-Catalyzed 1,3-Thiazine Formation and Uncommon Tautomer Isolation.

This work represents the first example of a gold-catalyzed formation of 1,3-thiazine/1,3-thiazinane by means of a catalytic approach and further uncommon isolation of the two tautomers. The developed protocol gives rise to a broad scope of 1,3-thiazine derivatives with excellent yields in short reaction times. Interestingly, different isomers could be obtained depending on the state of the compound, and in the crystal state the 1,3-thiazinane isomer is obtained, while in solution the 1,3-thiazine is the unique isomer. This work represents an interesting approach for the synthesis of potential biologically relevant molecules and a crucial precedent in tautomerism isolation and characterization.

Correlates to psychological distress in frail older community-dwellers undergoing lockdown during the COVID-19 pandemic.

BACKGROUND: This study identifies correlates of the lockdown's psychological distress in frail older community-dwellers (Catalonia, Spain). METHODS: Participants from a community frailty intervention program, with a comprehensive geriatric assessment within the 12-months pre-lockdown and COVID-19 free during the first pandemic wave (March-May 2020), underwent a phone assessment past the lockdown to assess COVID-19-related emotional distress (DME) as well as other sociodemograhic, clinical and psychosocial factors. RESULTS: Of the 94 frail older adults (age = 82,34 ± 6,12 years; 68,1% women; 38,3% living alone), 84,9% were at risk of experiencing moderate-to-high psychological distress, according to the backward stepwise logistic regression model obtained (χ2 = 47,007, p < 0,001, Nagelkerke R2 = 0,528), based on the following factors: absence of depressive symptoms before lockdown (OR = 0,12, p = 0,014, 95%CI[0,023-0,647]), not carrying out leisure activities during lockdown (OR = 0,257, p = 0,023, 95%CI[0,079-0,832]) and currently experiencing high malaise due to COVID-19 situation (OR = 1,504, p < 0,001, 95%CI[1,241-1,822]). DISCUSSION: These findings suggest that it is necessary to favour a prior overall health status and to empower frail older community-dwellers in the use of a broad repertoire of coping strategies in the face of adversity to foster mental health and keep at bay the potential emotional impact of the situation generated by the COVID pandemic.

Rennet-Induced Casein Micelle Aggregation Models: A Review.

Two phases are generally recognized in the enzymatic coagulation of milk: hydrolysis and aggregation, although nowadays more and more researchers consider the non-enzymatic phase to actually be a stage of gel formation made up of two sub-stages: micellar aggregation and hardening of the three-dimensional network of para-κ-casein. To evaluate this controversy, the main descriptive models have been reviewed. Most of them can only model micellar aggregation, without modeling the hardening stage. Some are not generalizable enough. However, more recent models have been proposed, applicable to a wide range of conditions, which could differentiate both substages. Manufacturing quality enzymatic cheeses in a cost-effective and consistent manner requires effective control of coagulation, which implies studying the non-enzymatic sub-stages of coagulation separately, as numerous studies require specific measurement methods for each of them. Some authors have recently reviewed the micellar aggregation models, but without differentiating it from hardening. Therefore, a review of the proposed models is necessary, as coagulation cannot be controlled without knowing its mechanisms and the stages that constitute it.

The Barcelona Predictive Model of Clinically Significant Prostate Cancer.

A new and externally validated MRI-PM for csPCa was developed in the metropolitan area of Barcelona, and a web-RC designed with the new option of selecting the csPCa probability threshold. The development cohort comprised 1486 men scheduled to undergo a 3-tesla multiparametric MRI (mpMRI) and guided and/or systematic biopsies in one academic institution of Barcelona. The external validation cohort comprised 946 men in whom the same diagnostic approach was carried out as in the development cohort, in two other academic institutions of the same metropolitan area. CsPCa was detected in 36.9% of men in the development cohort and 40.8% in the external validation cohort (p = 0.054). The area under the curve of mpMRI increased from 0.842 to 0.897 in the developed MRI-PM (p < 0.001), and from 0.743 to 0.858 in the external validation cohort (p < 0.001). A selected 15% threshold avoided 40.1% of prostate biopsies and missed 5.4% of the 36.9% csPCa detected in the development cohort. In men with PI-RADS <3, 4.3% would be biopsied and 32.3% of all existing 4.2% of csPCa would be detected. In men with PI-RADS 3, 62% of prostate biopsies would be avoided and 28% of all existing 12.4% of csPCa would be undetected. In men with PI-RADS 4, 4% of prostate biopsies would be avoided and 0.6% of all existing 43.1% of csPCa would be undetected. In men with PI-RADS 5, 0.6% of prostate biopsies would be avoided and none of the existing 42.0% of csPCa would be undetected. The Barcelona MRI-PM presented good performance on the overall population; however, its clinical usefulness varied regarding the PI-RADS category. The selection of csPCa probability thresholds in the designed RC may facilitate external validation and outperformance of MRI-PMs in specific PI-RADS categories.

Assessment of Water Quality Parameters and their Seasonal Behaviour in a Portuguese Water Supply System: a 6-year Monitoring Study.

Water quality monitoring is a fundamental tool in the management of freshwater resources. The purpose of monitoring is to provide meaningful quality data for local action planning and catchment-wide decision making. The assessment of water quality is crucial to guarantee the efficient operation of the Water Treatment Plants (WTPs), promoting health conditions and contributing for a more sustainable urban water cycle. In accordance, the objective of this study was to evaluate key target chemical and microbiological water quality parameters, some of them already monitored within Portuguese/EU legal framework and others still not regulated, but with environmental and human heath relevance. A local monitoring database model, using a 6-year period (from 2014 to 2019) of water quality data, regarding water samples collected on representative sampling locations covering the freshwater abstraction sites, conventional WTPs and distribution network was assessed. This work provides new knowledge regarding occurrence and seasonal behaviour for both microbiological and chemical water quality parameters, essential to understand/manage the water supply system. Additionally, relationships between the target variables were also assessed. Particularly, strong correlations were identified between TOC and THMs formation at distribution network (r = 0.69; p ≤ 0.001); nitrates were the water quality parameter that revealed the best correlation between surface water source and treated water (r = 0.81; p ≤ 0.001), suggesting that treatment yield/performance is dependent on surface water load. The local and continuous monitoring of water systems are crucial to implement new approaches to guarantee the best quality of drinking water throughout the supply system.

From Thioureas to Thioquinolines through Isolated Benzothiazines by Gold Catalysis.

New benzothiazine heterocycles have been formed from thiourea derivatives by using different gold catalysts. The catalyst and the conditions were optimised towards the selective synthesis of six-membered benzothiazine heterocycles, characterised by X-ray diffraction. Interestingly, these organic compounds evolved under gold catalysis in basic medium to achieve the formation of amino thioquinolines through an unprecedented aromatisation process of the heterocycle. The reaction was also carried out stoichiometrically by reaction with gold complexes to afford thioquinolines coordinated to the gold fragment. Benzothiazine, amino thioquinoline heterocycles and gold-derived species have a great potential for biological applications.

Assessment of the Presence of Hepatitis E virus in Surface Water and Drinking Water in Portugal.

Hepatitis E virus (HEV) is a non-enveloped single-stranded positive-sense RNA virus, belonging to the Hepeviridae family, resistant to environmental conditions, and transmitted by the consumption of contaminated water. This virus is responsible for both sporadic and epidemic outbreaks, leading to thousands of infections per year in several countries, and is thus considered an emerging disease in Europe and Asia. This study refers to a survey in Portugal during 2019, targeting the detection and eventual quantification of enteric viruses in samples from surface and drinking water. Samples positive for HEV RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR), in both types of matrix. The infectivity of these samples was evaluated in cultured Vero E6 cells and RNA from putative viruses produced in cultures evidencing cytopathic effects and was subjected to RT-qPCR targeting HEV genomic RNA. Our results evidenced the existence of samples positive either for HEV RNA (77.8% in surface water and 66.7% in drinking water) or for infectious HEV (23.0% in surface water and 27.7% in drinking water). These results highlight the need for effective virological control of water for human consumption and activities.

O mal-estar docente nas discussões sobre ensino nutrição: falas de professoras da educação básica em fóruns virtuais / Teachers malaise in discussions about teaching nutrition: speeches of basic education teachers in virtual forums / El malestar docente en las discusiones sobre nutrición: relatos de profesoras de la educación básica en foros virtuales

Resumo As expectativas institucionais e sociais relacionadas ao trabalho docente intensificaram-se. A atividade docente é hoje caracterizada pela precarização do trabalho, associada a uma concepção da escola como empresa, na qual são frequentes os múltiplos vínculos de trabalho com elevada carga horária, com consequências negativas sobre a saúde docente. No presente estudo, relatamos achados qualitativos obtidos da análise de postagens de professoras da educação básica em um fórum virtual sobre educação nutricional. Tais discussões espontâneas das professoras revelaram um contraste entre a intensa preocupação com a saúde nutricional de seus alunos que mascara a atenção a essas questões em relação a si mesmas. A incorporação pelas professoras de expectativas socialmente impostas no sentido de solucionarem questões complexas como a obesidade entre estudantes parece adquirir tais dimensões que obliteram a discussão à própria saúde nutricional. Essas expectativas, quando impostas sem os meios para seu atendimento podem contribuir para o sofrimento docente. Destacamos, ainda, a importância da existência de espaços e condições de escuta de professores envolvidos com a educação sobre temas de saúde nas escolas.

Abstract Institutional and social expectations related to teaching work have intensified. The teaching activity is nowadays characterized by precarious work, associated with a conception of the school as a company, in which multiple work links with a high workload are frequent, with negative consequences on teaching health. In the present study, we report qualitative findings obtained from the analysis of posts by teachers of basic education in a virtual forum on nutrition education. Such spontaneous discussions by the teachers revealed a contrast between the intense concern with the nutritional health of their students that masks the attention to these issues in relation to themselves. The incorporation of socially imposed expectations by teachers in order to solve complex issues such as obesity among students seems to acquire such dimensions that obliterate the discussion on nutritional health itself. These expectations, when imposed without the means to meet them, can contribute to teacher suffering. We also highlight the importance of the existence of spaces and listening conditions for teachers involved in education on health issues in schools.

Resumen Las expectativas institucionales y sociales relacionadas al trabajo docente se intensificaron. La actividad docente actualmente se caracteriza por la precariedad del trabajo, asociada a un concepto que se tiene de la escuela como empresa, en la que son frecuentes los diversos vínculos laborales con una alta carga de horas de trabajo, lo que acarreta consecuencias negativas en la salud docente. En este estudio, relatamos hallazgos cualitativos obtenidos del análisis de publicaciones de profesoras de la educación básica en un foro virtual sobre educación nutricional. Tales discusiones espontáneas de las profesoras revelaron un contraste entre la intensa preocupación con la salud nutricional de sus alunos que enmascaran la atención a esas cuestiones en relación a si misma. La incorporación por parte de las profesoras de expectativas socialmente impuestas a fin de resolver cuestiones complejas como la obesidad entre los estudiantes parece adquirir dimensiones que destruyeron la discusión de la propia salud nutricional. Esas expectativas, cuando son impuestas sin los medios para su atención pueden contribuir para el sufrimiento docente. Destacamos, también, la importancia de la existencia de espacios y condiciones para escuchar a los profesores involucrados en la educación sobre temas de salud en las escuelas.

Towards a gamete matching platform: using immunogenetics and artificial intelligence to predict recurrent miscarriage.

The degree of Allele sharing of the Human Leukocyte Antigen (HLA) genes has been linked with recurrent miscarriage (RM). However, no clear genetic markers of RM have yet been identified, possibly because of the complexity of interactions between paternal and maternal genes during embryo development. We propose a methodology to analyse HLA haplotypes from couples either with histories of successful pregnancies or RM. This article describes a method of RM genetic-risk calculation. The proposed HLA representation techniques allowed us to create an algorithm (IMMATCH) to retrospectively predict RM with an AUC = 0.71 (p = 0.0035) thanks to high-resolution typing and the use of linear algebra on peptide binding affinity data. The algorithm features an adjustable threshold to increase either sensitivity or specificity, allowing a sensitivity of 86%. Combining immunogenetics with artificial intelligence could create personalised tools to better understand the genetic causes of unexplained infertility and a gamete matching platform that could increase pregnancy success rates.

Shigella IpaA Binding to Talin Stimulates Filopodial Capture and Cell Adhesion.

The Shigella type III effector IpaA contains three binding sites for the focal adhesion protein vinculin (VBSs), which are involved in bacterial invasion of host cells. Here, we report that IpaA VBS3 unexpectedly binds to talin. The 2.5 Å resolution crystal structure of IpaA VBS3 in complex with the talin H1-H4 helices shows a tightly folded α-helical bundle, which is in contrast to the bundle unraveling upon vinculin interaction. High-affinity binding to talin H1-H4 requires a core of hydrophobic residues and electrostatic interactions conserved in talin VBS H46. Remarkably, IpaA VBS3 localizes to filopodial distal adhesions enriched in talin, but not vinculin. In addition, IpaA VBS3 binding to talin was required for filopodial adhesions and efficient capture of Shigella. These results point to the functional diversity of VBSs and support a specific role for talin binding by a subset of VBSs in the formation of filopodial adhesions.

Whole-genome comparison of endogenous retrovirus segregation across wild and domestic host species populations.

Although recent advances in sequencing and computational analyses have facilitated use of endogenous retroviruses (ERVs) for deciphering coevolution among retroviruses and their hosts, sampling effects from different host populations present major challenges. Here we utilize available whole-genome data from wild and domesticated European rabbit (Oryctolagus cuniculus sp.) populations, sequenced as DNA pools by paired-end Illumina technology, for identifying segregating reference as well as nonreference ERV loci, to reveal their variation along the host phylogeny and domestication history. To produce new viruses, retroviruses must insert a proviral DNA copy into the host nuclear DNA. Occasional proviral insertions into the host germline have been passed down through generations as inherited ERVs during millions of years. These ERVs represent retroviruses that were active at the time of infection and thus present a remarkable record of historical virus-host associations. To examine segregating ERVs in host populations, we apply a reference library search strategy for anchoring ERV-associated short-sequence read pairs from pooled whole-genome sequences to reference genome assembly positions. We show that most ERVs segregate along host phylogeny but also uncover radiation of some ERVs, identified as segregating loci among wild and domestic rabbits. The study targets pertinent issues regarding genome sampling when examining virus-host evolution from the genomic ERV record and offers improved scope regarding common strategies for single-nucleotide variant analyses in host population comparative genomics.

Apoio Matricial e Capsi: desafios do cenário na implantação do matriciamento em saúde mental / Matrix Support and Capsi: scenario challenges in the deployment of the mental health matrix

RESUMO Este estudo qualitativo teve como objetivo explorar o conhecimento e a experiência de uma equipe de Centro de Atenção Psicossocial Infantil (Capsi) acerca da estratégia do Apoio Matricial (AM), com a participação de cinco profissionais da equipe de referência e quatro residentes multiprofissionais. A análise utilizou-se de dois encontros de Grupo Focal no Capsi em 2015-2016 e do Discurso do Sujeito Coletivo. Como resultado, não se chegou a uma definição clara sobre o tema e não se reconheceu uma experiência com AM, tendo dificuldades para implantar esta estratégia dentro das ações de cuidado em saúde mental. Levanta-se a necessidade de articulação de uma rede que realmente consiga contribuir com a mudança de paradigma do modelo médico hegemônico.

ABSTRACT This qualitative study aimed to explore the knowledge and experience of a Center for Child Psychosocial Care (Centro de Atenção Psicossocial Infantil - Capsi) team about Matrix Support Strategy (AM) by means of the participation of five professionals' reference team and four multidisciplinary residents. We used two Focus Groups in Capsi premises during 2015-2016 and applied the Collective Subject Discourse to analyze the speeches. As a result, it was not found any clear definition of the subject and no AM experience was recognized, struggling the implementation of the strategy within care actions in mental health. We conclude by the need to articulate a network that can really contribute to the paradigm shift of the hegemonic medical model.

Evaluating the influence of light intensity in mcyA gene expression and microcystin production in toxic strains of Planktothrix agardhii and Microcystis aeruginosa.

Cyanobacteria are phytoplanktonic organisms widely occurring in freshwaters, being frequently associated with the production of toxins, namely microcystins (MCs). MCs are produced non-ribosomally by a multienzyme complex (mcy genes). It has been reported that environmental factors, such as light intensity, can influence toxin production. The aim of this study was to assess the influence of light intensity in the transcription of the mcyA gene and corresponding production of microcystins in toxic isolates of Planktothrix agardhii, where little is known, and compare them to Microcystis aeruginosa. For that purpose, cultures were exposed to three different light intensities (4, 20 and 30 µmol photons m(-2) s(-1)) for 18 days at 20 ± 1 °C. The growth was followed daily using absorbance readings. Samples were collected at each growth stage for cell counting, microcystins quantification and RNA extraction. The level of transcripts was quantified by RT-qPCR and the relative expression determined using 16S rDNA, gltA and rpoC1 as reference genes. The most stable reference genes in M. aeruginosa were rpoC1 and gltA, whereas in P. agardhii were 16S rDNA and gltA. There was a correspondence between the growth rate and light intensity in M. aeruginosa and P. agardhii. The growth rates for both species were lower at 4 and higher at 30 µmol photons m(-2) s(-1). Microcystin concentration per cell was similar between light intensities in M. aeruginosa and over time, while in P. agardhii it was higher in the stationary phase at 4 µmol photons m(-2) s(-1). There were differences in the expression of mcyA between the two species. In M. aeruginosa, the highest levels of expression occurred at 4 µmol photons m(-2) s(-1) in the adaptation phase, whereas for P. agardhii it was at 4µmol photons m(-2) s(-1) in the exponential growth phase. Our results indicate that the light intensities tested had distinct influences on the growth, microcystin production and mcyA expression levels, presenting considerable differences in M. aeruginosa and P. agardhii.

Avaliação dos eventos sexuais de touros Nelore adultos em testede libido realizado em curral / Evaluation of sexual events of mature Nelore bulls in pen libido test

Um total de 38 touros adultos, aprovados andrologicamente, foi submetido ao teste de libido em curral, sendo avaliados oseventos: reflexo de Flehmen (1), perseguição ativa, com posicionamento (2), impulso de monta (3), tentativa de monta (4),monta abortada (5), monta abortada com perseguição (6) e monta completa (7). Após esta avaliação, os touros foram definidosem três categorias: alta libido – eventos 6 e 7; média libido – eventos 3 a 5 e baixa libido – eventos 1 e 2. Registrou-se altapercentagem (68,42 por cento) de animais com alta ou média libido. Durante os testes de libido, as freqüências médias dos eventosde 1 a 7 foram, respectivamente, 3,02 ± 1,6; 0,44 ± 079; 0,92 ± 1,17; 0,68 ± 0,98; 0,10 ± 0,38; 0,10 ± 0,31 e 0,23 ± 0,48. Obse rvou-se que, após dois minutos e 30 segundos de teste, os touros de baixa libido efetuaram o dobro do evento 1 (reflexo deFlehmen), quando comparados aos touros de alta libido (p>0,05). Observaram-se correlações negativas de média magnitudeentre o evento 1 e os eventos 3, 4, respectivamente, -0,40 e -0,42. Já os eventos 3, 4, 6 e 7 apresentaram correlações de médiapara alta magnitude, com a classificação final da libido, respectivamente, 0,47; 0,37; 0,44 e 0,67. Para os touros que reagiramao teste a média do tempo para a primeira atitude de interesse por uma fêmea (TIS) foi de 40,88 ± 53,02 segundos, comvariações de 10 a 210 segundos. Já o tempo para a primeira atitude de monta (TAM) foi de 101,20 ± 74,03 segundos, variandode 10 a 250 segundos. O TR, para os touros que efetuaram monta completa foi de 200,18 ± 107,77 segundos, variando de 10a 310 segundos.. Registraram-se correlações significativas entre TIS e TAM (0,48) e de TR e TAM (0,65). Conclui-se que oestudo detalhado dos eventos sexuais podem indicar importantes marcadores do comportamento sexual de touros da raçaNelore, direcionando as adaptações necessárias nos testes de libido em curral para touros zebuínos.

A total of 38 Nelore adult bulls, andrologicaly evaluated, were pen tested for libido, being observed the following Sexual reaction(SR): Flehmen reflex (1), active riding with mounting positioning (2), impulse of mounting (3), attempts to mount (4), abortemounting (5), mounting attempts with new attempts (6), and full mounting (7). Bulls were classified as high libido (scores 6 an7), medium libido (scores 3 to 5) and low libido (scores 1 and 2). It was registered high rate (68.42 percent) of bulls with medium anhigh libido. Mean frequency for SR 1 to 7 were, respectively, 3.02 ± 1.6; 0.44 ± 0.79; 0.92 ± 1.17; 0.68 ± 0.98; 0.10 ± 0.38; 0 .100.31 e 0.23 ± 0.48. After 2 minutes and 30 seconds of libido test, bulls classified as low libido realized two times more the S1, when compared to bulls classified as high libido (p>0,05). Negative correlations among SR 1 and SR 3, 4 of -0.40 e -0.4respectively, were recorded. SR 3, 4, 6 and 7 showed correlations varying from medium to high with final libido classificatiorespectively, 0,47; 0.37; 0.44 e 0.67. Among bulls that react to the libido test, the mean reaction time for the first reaction tofemale in heat (RF) was 40.88 ± 53.02 seconds (ranging from 10 to 210 seconds) and the mean mounting reaction time (MTwas 101.20 ± 74.03 seconds (ranging from 10 to 250 seconds). RT for bulls that realized full mounting was 200.18 ± 107.7second, with variations from 10 to 310 seconds. Correlations of 0.48 between RF and MT and 0.65 between RT and MT werecorded (p<0,05). It was concluded that the sexual events are important for make adaptations in pen libido test for zebu bullFurthermore, the pen libido test was efficient in selecting bulls that realized higher number of full mountings.Keywords: sexual behavior, Nelore bulls, Zebu.

Avaliação dos eventos sexuais de touros Nelore adultos em teste de libido realizado em curral

Um total de 38 touros adultos, aprovados andrologicamente, foi submetido ao teste de libido em curral, sendo avaliados oseventos: reflexo de Flehmen (1), perseguição ativa, com posicionamento (2), impulso de monta (3), tentativa de monta (4),monta abortada (5), monta abortada com perseguição (6) e monta completa (7). Após esta avaliação, os touros foram definidosem três categorias: alta libido eventos 6 e 7; média libido eventos 3 a 5 e baixa libido eventos 1 e 2. Registrou-se altapercentagem (68,42%) de animais com alta ou média libido. Durante os testes de libido, as freqüências médias dos eventosde 1 a 7 foram, respectivamente, 3,02 ± 1,6; 0,44 ± 079; 0,92 ± 1,17; 0,68 ± 0,98; 0,10 ± 0,38; 0,10 ± 0,31 e 0,23 ± 0,48. Observouseque, após dois minutos e 30 segundos de teste, os touros de baixa libido efetuaram o dobro do evento 1 (reflexo deFlehmen), quando comparados aos touros de alta libido (p>0,05). Observaram-se correlações negativas de média magnitudeentre o evento 1 e os eventos 3, 4, respectivamente, -0,40 e -0,42. Já os eventos 3, 4, 6 e 7 apresentaram correlações de médiapara alta magnitude, com a classificação final da libido, respectivamente, 0,47; 0,37; 0,44 e 0,67. Para os touros que reagiramao teste a média do tempo para a primeira atitude de interesse por uma fêmea (TIS) foi de 40,88 ± 53,02 segundos, comvariações de 10 a 210 segundos. Já o tempo para a