Riqueza e distribuição temporal de anuros (Amphibia: Anura) em um fragmento de Floresta Ombrófila Mista

Apesar do Brasil abrigar uma riqueza elevada de anfíbios anuros, muitas regiões ainda são consideradas subamostradas, incluindo ecossistemas que estão degradados e ameaçados. Esse é o caso da Floresta Ombrófila Mista (FOM), formação que possui apenas 3% de sua distribuição original, sendo que apenas uma porcentagem menor ainda constitui florestas em estágio primário ou avançado. O objetivo deste estudo foi determinar a estrutura de uma taxocenose de anuros em um remanescente de FOM, avaliar a variação de riqueza e abundância em função de variáveis climáticas, comparar a taxocenose com outras oito inseridas na mesma formação e verificar se a riqueza registrada nas localidades varia em função da área total, da quantidade ou dos tipos de ambientes presentes. Foram realizadas 12 campanhas entre setembro de 2008 e agosto de 2009, totalizando 72 horas de amostragem. Por meio dos métodos de amostragem em sítio de reprodução em sete corpos d'água e de busca aural em quatro transecções no interior da floresta, foi registrada a ocorrência de 24 espécies de sete famílias, correspondendo a 96% da riqueza estimada para a área. Tanto a riqueza quanto a abundância foram registradas no período com maior volume de chuva. O número de espécies nos ambientes amostrados variou de um a 15, e quase metade (41%) delas foram exclusivas de ambientes florestais. Para os inventários de anuros em FOM, o que explica a maior riqueza de espécies é a quantidade de tipos de ambientes amostrados, indicando que amostragens em localidades mais heterogêneas, que podem satisfazer os requisitos reprodutivos de um maior número de espécies, aumentam o registro da riqueza local. Mesmo sendo um fragmento pequeno e alterado, a riqueza registrada foi alta se comparada com outras áreas cuja anurofauna foi inventariada, e que estão inseridas na FOM e apresentam esforço amostral semelhante. Devido à ocorrência de muitas espécies dependentes da integridade da floresta a minimização de atividades antrópicas e estudos mais detalhados devem ser as principais diretrizes para a manutenção e conservação local.

Variación espacio-temporal de Chironomidae (Diptera) bentónicos y derivantes en un arroyo serrano en Córdoba, Argentina

Chironomidae es una de las familias más abundantes y diversas en los ecosistemas de agua dulce, sin embargo su complejidad sistemática ha sido motivo de su escaso desarrollo en muchos estudios limnológicos. El objetivo de este estudio fue analizar los ensambles de Chironomidae bentónicos y derivantes de un arroyo serrano de la región central de Argentina evaluando abundancia, diversidad y composición de especies en diferentes hábitats fluviales y distintas estaciones del año. Se tomaron muestras cuantitativas de bentos y deriva en el arroyo Achiras (Córdoba, Argentina) en hábitats de rabión y corredera, y se registraron variables ambientales en las cuatro estaciones del año, entre 2007 y 2008. Se registró un total de 25 taxones pertenecientes a cuatro subfamilias. Los quironómidos bentónicos constituyeron el 19% de la comunidad de macroinvertebrados, mientras que en deriva representaron el 33%. En el bentos dominó Thienemannimyia sp. y en la deriva, Corynoneura sp. De acuerdo con los resultados de ANOVAs de dos vías, los mayores valores de riqueza taxonómica y densidad bentónica se registraron en el periodo de aguas bajas (otoño e invierno) y la diversidad de quirónomidos bentónicos fue mayor en rabión. Por el contrario, para el ensamble de derivantes sólo la equitatividad fue diferente entre hábitats y entre estaciones. El análisis TWINSPAN mostró una separación espacio-temporal de las muestras de bentos, mientras que las muestras de deriva se segregaron sólo temporalmente lo que sugiere que el transporte aguas abajo de los invertebrados homogeniza la variación espacial observada en el bentos. La densidad de bentos y deriva varió de manera similar a través de las estaciones del año y el coeficiente de Jaccard presentó un alto índice de similitud entre bentos y deriva (86%). Este trabajo posibilitó conocer la dinámica temporal y espacial de los quironómidos bentónicos y derivantes en un arroyo serrano. La ampliación del conocimiento taxonómico, biológico y ecológico de Chironomidae posibilitará adecuar e implementar estrategias de manejo y conservación de los ecosistemas lóticos en la región central de Argentina.

Distribuição espacial e temporal de espécies de Bledius (Coleoptera, Staphylinidae) em praias arenosas no sul do Brasil

Besouros da família Staphylinidae são comuns em zonas costeiras inundáveis pelas marés, como praias arenosas, manguezais, estuários e marismas. O objetivo desse trabalho foi estudar a distribuição espacial e a variação temporal da abundância ao longo de um ano, das espécies ocorrentes em duas praias arenosas (Assenodi e Cem) no Pontal do Paraná, Paraná, Brasil. Coletas semanais com um cilindro de PVC com 15 cm de diâmetro (0,017 m²) enterrado a 5 cm de profundidade, foram realizadas de janeiro a dezembro de 2012. A praia Assenodi apresentou altos valores de umidade de sedimento no supralitoral e pós-praia. Nesta praia, Bledius bonariensis foi dominante, mas também houve registro de B. fernandezi, ambas distribuídas nas porções superiores do perfil praial e ocorreram ao longo de todo o ano. A praia Cem apresentou valores altos de umidade do sedimento apenas no mesolitoral, em decorrência da subida e descida da maré, neste estrato B. hermani, foi a espécie dominante. Bledius bonariensis teve ocorrência ocasional em alguns meses do outono e inverno, associada a um aumento nas precipitações. A variação na abundância de B. hermani foi grande, sendo os maiores valores associados às altas temperaturas do verão. As espécies de Bledius mostraram uma clara separação espacial relacionada a distintos requerimentos ambientais, o que possibilita a coocorrência das três espécies na mesma praia em função de variações ambientais ao longo do ano.

Diversidad, distribución espacio-temporal y turnos de vocalización de anuros (Amphibia, Anura) en un área ecotonal del nordeste de Argentina

RESUMEN Estudios acerca de la diversidad e historia natural de comunidades de anuros son elementales para distinguir entre fluctuaciones naturales de aquellas causadas por impactos antrópicos (herramienta clave en programas de conservación), evaluar el papel que juegan en la dinámica de los ecosistemas y permitir comparaciones de gradientes de diversidad. En este contexto, se analiza la diversidad, la distribución temporal y espacial, y los turnos de vocalización de anuros de tres sitios de reproducción en los Esteros del Iberá, en el nordeste de Argentina. Los muestreos fueron mensuales entre julio de 2008 y junio de 2010. Se registraron 26 especies pertenecientes a cinco familias: Bufonidae (2), Hylidae (11), Leptodactylidae (11), Microhylidae (1), y Odontophrynidae (1). Se encontraron variaciones en la riqueza de especies por sitio, en el periodo, frecuencia y turno de vocalización y en la abundancia de machos vocalizadores. La riqueza es similar al de otros humedales similares, incluyendo un importante dominio de leptodactílidos e hílidos, patrón frecuente en ensambles neotropicales. La concentración de las especies en actividad de vocalización en los meses más cálidos y lluviosos estuvo asociada con los cambios en la temperatura y en las precipitaciones, las cuales fueron señaladas como algunos de los factores que inician la actividad reproductiva en ambientes estacionales.

Automatic top-down processing explains common left occipito-temporal responses to visual words and objects.

Previous studies have demonstrated that a region in the left ventral occipito-temporal (LvOT) cortex is highly selective to the visual forms of written words and objects relative to closely matched visual stimuli. Here, we investigated why LvOT activation is not higher for reading than picture naming even though written words and pictures of objects have grossly different visual forms. To compare neuronal responses for words and pictures within the same LvOT area, we used functional magnetic resonance imaging adaptation and instructed participants to name target stimuli that followed briefly presented masked primes that were either presented in the same stimulus type as the target (word-word, picture-picture) or a different stimulus type (picture-word, word-picture). We found that activation throughout posterior and anterior parts of LvOT was reduced when the prime had the same name/response as the target irrespective of whether the prime-target relationship was within or between stimulus type. As posterior LvOT is a visual form processing area, and there was no visual form similarity between different stimulus types, we suggest that our results indicate automatic top-down influences from pictures to words and words to pictures. This novel perspective motivates further investigation of the functional properties of this intriguing region.

Variabilitat temporal i geogràfica i caracterització química de la contaminació atmosfèrica particulada a Sabadell

Estudi de 3 punts amb diferent intensitat de trànsit a Sabadell: punt de trànsit, fons urbà i fons suburbà. Nivells de PM i altres gasos contaminants van ser mesurats durant 1 mes. Els objectius principals són la correlació dels nivells de partícules i NOx als 3 punts d’estudi (ja que als estudis epidemiològics s’utilitza NO2 com a indicador del nivell de partícules); la caracterització química de les partícules per determinar quina porció té origen en les emissions dels tubs d’escapament i identificar similituds i diferències entre els nivells i composició de partícules entre les diferents estacions seleccionades.

Automatic measurement of key ski jumping phases and temporal events with a wearable system.

We propose a new method, based on inertial sensors, to automatically measure at high frequency the durations of the main phases of ski jumping (i.e. take-off release, take-off, and early flight). The kinematics of the ski jumping movement were recorded by four inertial sensors, attached to the thigh and shank of junior athletes, for 40 jumps performed during indoor conditions and 36 jumps in field conditions. An algorithm was designed to detect temporal events from the recorded signals and to estimate the duration of each phase. These durations were evaluated against a reference camera-based motion capture system and by trainers conducting video observations. The precision for the take-off release and take-off durations (indoor < 39 ms, outdoor = 27 ms) can be considered technically valid for performance assessment. The errors for early flight duration (indoor = 22 ms, outdoor = 119 ms) were comparable to the trainers' variability and should be interpreted with caution. No significant changes in the error were noted between indoor and outdoor conditions, and individual jumping technique did not influence the error of take-off release and take-off. Therefore, the proposed system can provide valuable information for performance evaluation of ski jumpers during training sessions.

Distribuição temporal de perfis eletrofocéticos de Acido nucleico de rotavírus em fezes de crianças em Belém, Pará

Amostras de rotavírus provenientes de crianças habitantes na periferia de Belém, Pará, foram analisadas por eletroforese em gel de policrilamida (PAGE). As bandas correspondentes aos 11 segmentos de ARN foram detectadas em 46 (76,7%) das 60 amostras de rotavírus. Das amostras classificadas 5 (109%) foram relativas ao subgrupo I, 41 (89,1%) ao subgrupo II e, em 23,3%) não foi possível classificação face a ausência das bandas 10 e 11. As amostras de rotavírus sub-grupo II e codificadas como "1N2L" foram as mais freqüentes, ocorrendo em 30 (65,2%) das 46 classificadas.

Temporal and spatial appearance of the membrane cytoskeleton and perineuronal nets in the rat neocortex.

Parvalbumin-immunoreactive interneurons are surrounded by perineuronal nets, containing molecules of the extracellular matrix (e.g. tenascin-R). Furthermore, they seem to have a special cytoskeleton composed of, among others, ankyrinR and beta Rspectrin. In the present developmental study we showed that the intracellular markers parvalbumin, ankyrinR and beta Rspectrin as well as Vicia Villosa agglutinin, an extracellular marker for perineuronal nets, appeared in the second postnatal week. In the third postnatal week, ankyrinR and beta R spectrin were present in the parvalbumin-positive interneurons. Tenascin-R appeared in a similar topographic distribution as the intracellular markers. The adult pattern was established upon the end of the fourth postnatal week. Our results indicate that cytoskeletal maturity maybe a prerequisite for the organization of perineuronal nets of extracellular matrix.

Improved temporal resolution for functional studies with reduced number of segments with three-dimensional echo planar imaging.

PURPOSE: To introduce a new k-space traversal strategy for segmented three-dimensional echo planar imaging (3D EPI) that encodes two partitions per radiofrequency excitation, effectively reducing the number excitations used to acquire a 3D EPI dataset by half. METHODS: The strategy was evaluated in the context of functional MRI applications for: image quality compared with segmented 3D EPI, temporal signal-to-noise ratio (tSNR) (the ability to detect resting state networks compared with multislice two-dimensional (2D) EPI and segmented 3D EPI, and temporal resolution (the ability to separate cardiac- and respiration-related fluctuations from the desired blood oxygen level-dependent signal of interest). RESULTS: Whole brain images with a nominal voxel size of 2 mm isotropic could be acquired with a temporal resolution under half a second using traditional parallel imaging acceleration up to 4× in the partition-encode direction and using novel data acquisition speed-up of 2× with a 32-channel coil. With 8× data acquisition speed-up in the partition-encode direction, 3D reduced excitations (RE)-EPI produced acceptable image quality without introduction of noticeable additional artifacts. Due to increased tSNR and better characterization of physiological fluctuations, the new strategy allowed detection of more resting state networks compared with multislice 2D-EPI and segmented 3D EPI. CONCLUSION: 3D RE-EPI resulted in significant increases in temporal resolution for whole brain acquisitions and in improved physiological noise characterization compared with 2D-EPI and segmented 3D EPI. Magn Reson Med 72:786-792, 2014. © 2013 Wiley Periodicals, Inc.

Automatic front-crawl temporal phase detection using adaptive filtering of inertial signals

This study introduces a novel approach for automatic temporal phase detection and inter-arm coordination estimation in front-crawl swimming using inertial measurement units (IMUs). We examined the validity of our method by comparison against a video-based system. Three waterproofed IMUs (composed of 3D accelerometer, 3D gyroscope) were placed on both forearms and the sacrum of the swimmer. We used two underwater video cameras in side and frontal views as our reference system. Two independent operators performed the video analysis. To test our methodology, seven well-trained swimmers performed three 300 m trials in a 50 m indoor pool. Each trial was in a different coordination mode quantified by the index of coordination. We detected different phases of the arm stroke by employing orientation estimation techniques and a new adaptive change detection algorithm on inertial signals. The difference of 0.2 +/- 3.9% between our estimation and video-based system in assessment of the index of coordination was comparable to experienced operators' difference (1.1 +/- 3.6%). The 95% limits of agreement of the difference between the two systems in estimation of the temporal phases were always less than 7.9% of the cycle duration. The inertial system offers an automatic easy-to-use system with timely feedback for the study of swimming.

How are temporal and social comparisons related to appraisals of self-rated health during very old age?

This study investigated the direction of effects of temporal and downward social comparisons on self-rated health in very old age. Self-rated health can either reinforce or hinder comparison processes. In the framework of the Swiss Interdisciplinary Longitudinal Study on the Oldest Old, individuals aged 80 to 84 at baseline were interviewed and followed longitudinally for 5 years. Multilevel analyses were used to test the relative importance of temporal and social comparisons on self-rated health evaluations synchronically and diachronically (with a time lag of 12 to 18 months) as well as the direction of these relative influences. Results indicate that (a) at the synchronic level, continuity temporal comparisons have more impact than downward social comparisons on self-rated health; (b) both types of comparison had an independent and positive effect on self-rated health at the diachronic level; (c) self-rated health has an independent synchronic effect on both types of comparison and an independent diachronic effect in temporal comparison.

Spatial and temporal distribution of anopheline larvae in two malarious areas in Sucre State, Venezuela

The spatial and temporal distribution of anopheline larvae was studied in two coastal malarious areas of Sucre, State, Venezuela. Seven habitat types were sampled in the village of Guayana and eight species of Anopheles were collected. Anopheles aquasalis was the predominant species collected and was most abundant in the brackish marsh habitat (71 larvae per 100 samples). It was most abundant during the rainy season. At the second location, Santa F e, six habitat types were sampled and four anopheline species were collected. Habitats where An. aquasalis was most abundant were temporary freshwater ponds (34 larvae per 100 samples) and mangroves (10.5 larvae per 100 samples). At this location it was also most abundant in the rainy season. During the dry season it was collected in small numbers in river pools (1.3 larvae per 100 samples) along with large numbers of An. pseudopunctipennis (479 larvae per 100 samples). Larval control could be an important component of the malaria control program because major habitats could be defined and presence and abundance of larvae was limited to specific times of year.