Acute effects of different intervals between repeated sprints on performance responses in amateur futsal athletes / Efeitos agudos de diferentes intervalos entre sprint repetidos sobre as respostas de desempenho em atletas amadores de futsal

ABSTRACT Objective: Verify the influence of different break times between sprints on the performance of amateur futsal athletes. Methods: 10 individuals, men, amateur futsal athletes (Age: 21.5 ± 1.6; Weight: 72.4 ± 6.88; Height: 1.72 ± 0.05; BMI: 24.3 ± 1.2; Fat%: 13.7 ± 3.3, VO2peak: 49.1 ± 10.5) participated in the study. Individuals were randomly selected to perform sessions with sprints (10 sets 20 m) with different pause times of 15 (S15), 30 (S30) and 60 (S60) seconds. For performance analysis, the speed (km / h) applied to each sprint was used and monitored by a device with a photocell (CEFISE Biotecnologia Esportiva®). Results: There was an interaction between speed and interval time (p = 0.000). For condition S15, a greater reduction in performance was observed (p ≤ 0.05), while for S30 and S60, no significant reduction in performance was observed (p > 0.05). The data for the area under the curve showed a significant difference (p = 0.000), where the interval of 60 s (S60) was longer compared to the values of 30 (S30) (p = 0.000) and 15 s (S15) (p = 0.000). However, there were no significant differences between the 30 and 15 s data (p = 0.248). Conclusion: A shorter time (15 s) interval between repeated sprints can significantly affect performance compared to longer breaks (30 and 60 s), but all the conditions tested here can be positive for the improvement of performance, mainly in sports that demand fast and efficient motor actions such as futsal.

RESUMO Objetivo: Verificar a influência dos diferentes tempos de intervalo entre os sprints no desempenho dos atletas de futsal amadores. Métodos: 10 indivíduos, homens, atletas de futsal amadores (Idade: 21,5 ± 1,6; Peso: 72,4 ± 6,88; Altura: 1,72 ± 0,05; IMC: 24,3 ± 1,2; Gordura%: 13,7 ± 3,3, VO2peak: 49,1 ± 10,5) participou no estudo. Os indivíduos foram selecionados aleatoriamente para realizar sessões com sprints (10 conjuntos 20 m) com diferentes tempos de pausa de 15 (S15), 30 (S30) e 60 (S60) segundos. Para análise do desempenho, a velocidade (km/h) aplicada a cada sprint foi utilizada e monitorizada por um dispositivo com uma fotocélula (CEFISE Biotecnologia Esportiva®). Resultados: Houve uma interação entre velocidade e tempo de intervalo (p = 0,000). Para a condição S15, observou-se uma maior redução no desempenho (p ≤ 0,05), enquanto para S30 e S60, não se observou qualquer redução significativa no desempenho (p > 0,05). Os dados para a área sob a curva mostraram uma diferença significativa (p = 0,000), onde o intervalo de 60 s (S60) foi mais longo em comparação com os valores de 30 (S30) (p = 0,000) e 15 s (S15) (p = 0,000). No entanto, não houve diferenças significativas entre os dados de 30 e 15 s (p = 0,248). Conclusão: Um intervalo de tempo mais curto (15 s) entre sprints repetidos pode afetar significativamente o desempenho em comparação com os intervalos mais longos (30 e 60 s), mas todas as condições aqui testadas podem ser positivas para a melhoria do desempenho, principalmente nos desportos que exigem ações motoras rápidas e eficientes, tais como o futsal.

Possible Amazonian contribution to Sargassum enhancement on the Amazon Continental Shelf.

The Amazon Continental Shelf (ACS) has a coastline of ∼1000 km and is situated in a humid equatorial region with two distinct seasons, wet and dry, and two transitional climatic periods. A total of eight oceanographic cruises were conducted to investigate the dynamics of the inorganic nutrients dissolved in the surface layer of the water column of the ACS and their associations with Sargassum blooms. An excess of nitrogen-N* (NH4+ = 0.01-9.30 µmol l-1) was verified through the salinity gradient from the continent to the ACS, mainly during the period of maximum discharge of the Amazon and Tocantins-Pará rivers. The highest NH4+ concentrations coincided with the occurrence of macrophyte (Sargassum sp.) blooms in the mesohaline and oceanic regions. During this period the high values of NH4+ accompany the low values of Sea Surface Salinity (SSS), indicating the advection of the Amazonian plume towards the Caribbean Sea. In the Sargassum belts we observed a N:P ratio = 60:1 during wet period, while outside this region, the N:P ratio was 34:1. According to DIN vs. AOU ratio, we observed that heterotrophic processes prevail over productive processes, mainly in the mesohaline and low salinity regions. Nitrogen concentrations from runoff, mainly from hydrographic basins, showed significant increases in the last decade, mainly due to anthropogenic factors such as agriculture, deforestation, livestock, urban sewage (domestic and industrial), and demographic growth of the population in the Tocantins-Pará Basin. Additionally, associations of diatoms and cyanobacteria provide more nitrogen in the mesohaline and oceanic regions that nourishes Sargassum blooms. Seasonal comparisons (October and April) of Sargassum belts with other studies, indicated that currents play a fundamental role in the transport of these macrophytes from the east edge (Africa) to the west edge (Brazil and French Guiana) towards the Caribbean Sea in the tropical Atlantic.

Comparative evaluation of the DPP(®) CVL rapid test for canine serodiagnosis in area of visceral leishmaniasis.

We investigated the performance of the DPP(®) canine visceral leishmaniasis (CVL) rapid test, a novel immunochromatographic assay launched by BioManguinhos (Brazil), which was recently included in the new Brazilian protocol for screening CVL in serological surveys. The present study compared the DPP(®) with the ELISA and IFA produced by BioManguinhos (Brazil) both with L. major-like antigens and with in-house tests using Leishmania infantum chagasi (in-house ELISA and in-house IFA). We analyzed the sera from clinically symptomatic (n=47) and asymptomatic (n=38) infected dogs from an endemic area of CVL, as well as from healthy (n=18) dogs, in addition to the sera of dogs (n=81) infected with other pathogens. The DPP(®) and the in-house ELISA showed a sensitivity of 90.6% and 94.1%, respectively, and specificity of 95.1% and 97.5%, respectively, and both presented cross-reactivity only with the sera of dogs with babesiosis, 44% for the DPP(®) and 22% for the in-house ELISA. The clinical groups were detected equally by the two assays. The ELISA BioManguinhos, IFA BioManguinhos, and in house-IFA showed a good sensitivity, 90.6%, 96.5% and 89.4%, respectively, but very low specificity, 77.8%, 69.1% and 65.8%, respectively, due to the high cross-reactivity with the sera from the animals harboring other pathogens. The in-house ELISA provided the highest accuracy (95.8%), followed by the DPP(®) (92.7%), ELISA BioManguinhos (84.3%), IFA BioManguinhos (83.1%), and in-house IFA (78.0%). The simultaneous use of the DPP(®) and ELISA BioManguinhos reached a sensitivity of 99.1% and 82.1% when used sequentially. In conclusion, the DPP(®) performed well as serological test for CVL, and detected both asymptomatic and symptomatic dogs in equal proportions. Although its sensitivity is not ideal yet, discarding the IFA and including the DPP(®) improved the accuracy of the new Brazilian CVL diagnostic protocol, particularly of detecting truly infected dogs. Moreover, considering the higher specificity of DPP(®) (95.1% vs 77.8%), positive predictive value (95.1% vs 81.1%) and positive likelihood value (18.3% vs 4.1%) in comparison with the ELISA BioManguinhos, the use of DPP(®) as a confirmatory test instead of a screening test is suggested.

Police officers under attack: resilience implications of an fMRI study.

OBJECTIVE: Crime is now a top-priority public-health issue in many urban areas. Sao Paulo's state police force was the target of gunfire attack on an unprecedented scale. Several officers were killed or wounded, and many more were affected by psychological trauma. We investigated the brain activity underlying trauma, the coping effect of psychotherapy, and resilience in a highly homogenous sample that experienced the same traumatic event. The design applied was a between-group comparison of cerebral blood-oxygenation-level-dependent signals and symptom scores of police officers with and without partial Posttraumatic Stress Disorder (pPTSD). METHOD: We used functional magnetic resonance imaging (fMRI) to investigate the retrieval of traumatic memories of 36 volunteers divided in three groups: (1) pPTSD policemen submitted to psychotherapy; (2) pPTSD policemen on the wait list; and (3) symptom-free (resilient) policemen. All participants were given a baseline fMRI scan and a follow-up scan some 40 days later. Not given psychotherapy, groups 2 and 3 were controls. RESULTS: Group 1 showed 37% fewer PTSD symptoms post-psychotherapy and their scores and neural expressions were comparable to Group 3 resilient policemen. A marked increased in medial prefrontal cortex (mPFC) activity was concomitant with decreased amygdala activity during traumatic memory retrieval in both resilient and pPTSD participants (after psychotherapy) and these findings were associated with symptom attenuation. CONCLUSIONS: Our results provide neurophysiological evidence of resilience in a high-risk group for PTSD. Psychotherapy may help to build narratives and resilient integrated translations of fragmented traumatic memories via mPFC, and thus weaken their sensory content while strengthening them cognitively.