bluuebunny/crossref_metadata_2025 huggingface dataset:
Influência de variáveis do treinamento contra-resistência sobre a força muscular de idosos: uma revisão sistemática com ênfase nas relações dose-resposta
Authors: Silva Nádia Lima da , Farinatti Paulo de Tarso Veras
Published: September 2007

A força muscular é considerada componente importante de programas de exercícios físicos. Os benefícios desse tipo de treinamento dependem da combinação do número de repetições, séries, sobrecarga, seqüência e intervalos entre as séries e exercícios. No entanto, não se tem ainda muito clara qual a melhor combinação dessas variáveis para uma ótima relação dose-resposta em pessoas idosas. O objetivo do estudo foi analisar as pesquisas sobre treinamento de força para idosos, por meio de revisão sistemática, com o propósito de identificar tendências comuns em termos de efeitos do treinamento provocados pela manipulação dessas variáveis. Após definição de critérios de inclusão, foram selecionados 22 estudos, agrupados por similaridade de tratamento (número de séries, freqüência semanal, intensidade, intervalos e ordem dos exercícios). Técnicas de estatística descritiva auxiliaram na determinação de possíveis tendências nas relações dose-resposta. Uma vez identificadas, essas tendências foram analisadas qualitativamente. De todas as variáveis revisadas, somente para a intensidade da sobrecarga foram encontradas evidências permitindo afirmar que cargas maiores seriam mais eficazes para induzir aumento de força nessa faixa etária. Quanto às demais variáveis, os resultados disponíveis na literatura não dão respaldo para inferências seguras quanto ao melhor delineamento de programas de treinamento que aliem, ao mesmo tempo, efetividade e segurança. Recomenda-se, então, que estudos sejam realizados para comparar experimentalmente os efeitos da manipulação dessas variáveis sobre a força muscular de idosos.
Asma induzida pelo exercício: aspectos atuais e recomendações
Authors: Laitano Orlando , Meyer Flávia
Published: September 2007

OBJETIVO: Descrever os mecanismos da asma induzida pelo exercício (AIE), bem como os efeitos de diferentes tipos de treinamento físico na função pulmonar e nas capacidades aeróbia e anaeróbia. Destaca-se a importância de um diagnóstico correto mediante o teste de exercício e, no manejo, o uso de drogas beta-adrenérgicas e anticolinérgicas. FONTE DOS DADOS: Os artigos foram criteriosamente escolhidos utilizando as bases de dados PubMed e Scielo pelo ano de publicação e dando preferência a ensaios clínicos randomizados, com critérios de seleção da amostra bem definidos. SÍNTESE DOS DADOS: Os mecanismos para explicar a AIE permanecem sem conclusão, mas parece haver uma interação fisiológica entre as hipóteses aqui apresentadas. O uso de medicamentos e as freqüentes crises durante o exercício aparecem como fatores limitantes para a prática de exercícios físicos, conduzindo para um estilo de vida sedentário. CONCLUSÃO: Deve-se incentivar a prática de exercícios devidamente prescritos e minimizar as restrições aos sujeitos com AIE.
Reproductive biology of a population of Gymnotus aff.carapo (Teleostei: Gymnotidae) from southern Brazil
Authors: Cognato Diego de Paula , Fialho Clarice Bernhardt
Published: September 2007

The reproductive period and its relation with somatic and abiotic factors, the relative and absolute fecundity, spawning type, length of first maturation and sex ratio is describe for Gymnotus aff.carapo from a small lake at Itapuã State Park, Rio Grande do Sul, Brazil. Gymnotus aff. carapo presents a relatively long reproductive cycle extending from November/2003 to March/2004. Decreases in water conductivity and increases in dissolved oxygen are correlated with increased gonadal development in males. In females, seasonal increases in temperature and photoperiod and decreases in dissolved oxygen are correlated with increased gonadal development. The mean absolute fecundity was 915.3 oocytes, and mean relative fecundity 0.20 oocytes/mg body weight. Egg size distributions indicate multiple spawning. The size of first maturation was 141 mm in females and 146 mm in males. The sex ratio was 1:1, with a male bias only in smaller size classes.
Infestation pattern and parasitic castration of the crustacean Riggia paranensis (Crustacea: Cymothoidea) on the fresh water fish Cyphocharax gilbert (Teleostei: Curimatidae)
Authors: Azevedo Juliana de Souza , Silva Leonardo Gomes da , Bizerri Carlos Roberto Silveira Fontenelle , Dansa-Petretski Marilvia Alencar , Lima Neuza Rejane Wille
Published: September 2007

Cyphocharax gilbert infested by Riggia paranensis shows parasitic castration. The prevalence of parasitism in C. gilbert varied among different environments, being higher in the middle rio Itabapoana. Fish were collected monthly using two cast nets (thrown 30 times during the day) and gillnets kept in the river during 12 hour, from sunset to sunrise, between September 1997 and August 2000. Infestation pattern was investigated on 1358 specimens. Most of them were infested (57.9%), with one or two parasites; the majority (62.9%) was collected during the rainy season (spring-summer). The parasite did not show preference for sex or size of hosts. A total of 91.5% of the 511 examined parasites had a body size that represented 10.1% to 20% of host standard length. The reproductive condition of 311 specimens of R. paranensis was analyzed checking the presence of oocytes in the ovarian and eggs or embryos in the marsupium. Nearly 73% of them were at reproductive phase, and had a body size that represented 5.1% to 20% of host standard length. The size of the immature parasites varied from 0.1% to 5% of the host size. The results suggest that R. paranensis may adopt a fast growth rate strategy and increase the investment in reproduction when they occupy most of the host's pericardial space.
The air-breathing cycle of Hoplosternum littorale (Hancock, 1828)(Siluriformes: Callichthyidae)
Authors: Jucá-Chagas Ricardo , Boccardo Lilian
Published: September 2007

Hoplosternum littorale is a continuous air breather, which uses a portion of its intestine to extract oxygen from inspired air. Its air-breathing behavior occurs in four phases: 1) ascent to the water surface; 2) mouth emergence with expansion of the oral cavity for air inspiration; 3) downward swimming and oral cavity compression resulting in air swallowing and the expiration of old air from the anus; 4) return to bottom. The time required to complete the air-breathing cycle was significantly shorter for small fish compared to large fish.
Description of five new species of Acestrocephalus Eigenmann and redescription of A. sardina and A. boehlkei (Characiformes: Characidae)
Authors: Menezes Naércio A.
Published: September 2007

Acestrocephalus maculosus, A. stigmatus, A. nigrifasciatus, A. acutus, and A. pallidus are described as new species and A. sardina and A. boehlkei are redescribed. Acestrocephalus ginesi is considered synonymous with A. sardina. Specimens of Acestrocephalus anomalus, a valid trans-Andean species, were not available for study. Acestrocephalus stigmatus, A. maculosus, and A. boehlkei have a dark humeral blotch not present in the remaining species and the species within the two species groups thus characterized are told apart by meristic and morphometric data as well as morphological structures associated with the pseudotympanum.
Redescription of Pterygoplichthys punctatus and description of a new species of Pterygoplichthys (Siluriformes: Loricariidae)
Authors: Armbruster Jonathan W. , Page Lawrence M.
Published: September 2007

Pterygoplichthys punctatus and P. weberi, new species, are unique among hypostomines in having a medially divided buccal papilla. The two species can be separated from one another by color (small spots in P. punctatus, large in P. weberi), condition of the buccal papilla (deeply divided at all ages in P. punctatus vs. shallowly divided in adults of P. weberi), condition of the lateral keel odontodes (fairly short and directed posteriorly in P. punctatus vs. large and directed almost laterally in P. weberi), and body width (SL/cleithral width 3.6-4.0 in P. punctatus vs. 3.3-3.4 in P. weberi). Pterygoplichthys punctatus is known from the rio Madeira drainage and the rio Urubu of Brazil and has published, but unconfirmed localities in the rio Purus and rio Tocantins basin, and P. weberi is known from the Río Marañon, Río Ucayali, and upper Río Amazonas drainages of Colombia, Ecuador, and Peru.
A new species of Pimelodus LaCépède, 1803 (Siluriformes: Pimelodidae) from the rio São Francisco drainage, Brazil
Authors: Ribeiro Frank Raynner V. , Lucena Carlos Alberto S. de
Published: September 2007

Pimelodus pohli, new species, is described from the rio São Francisco drainage. It differs from congeners by the following characters in combination: adults with dark spots on anterodorsal region of body and young specimens (up to 100 mm SL) with three rows of dark spots laterally on body; comparatively long adipose fin, more than one third of the distance between posterior end of dorsal fin base and the vertical through posterior end of anal-fin base (21.8-26.2% SL); lips poorly developed; 20-25 gill rakers; and maxillary barbels slightly surpassing the caudal-fin base. A key to the species of Pimelodus of the rio São Francisco drainage is presented.
Fishes associated with spinner dolphins at Fernando de Noronha Archipelago, tropical Western Atlantic: an update and overview
Authors: Sazima Ivan , Sazima Cristina , Silva-Jr José Martins da
Published: September 2007

An update is presented for fish species associated with spinner dolphins at Fernando de Noronha Archipelago, tropical Western Atlantic, providing a general view of their diversity. The associates are mostly reef-dwelling fishes that feed on the dolphin wastes. Twelve species are habitual or occasional plankton-eaters and two species are herbivores that occasionally forage on floating pieces of algae. One species is a strict carnivore, one species is a hitchhiker that forages on a variety of foods including parasites and dead tissue from the dolphins, and one species is a carnivore that joins the dolphin groups to forage on schools of small fishes or squids. We predict that the list of fish associated with spinner dolphins will expand mostly with addition of habitual or occasional plankton-eaters.
Charax goeldii Fowler, 1913 a valid species of Galeocharax Fowler (Characiformes: Characidae)
Authors: Menezes Naércio A.
Published: September 2007

Charax goeldii Fowler is resurrected from synonymy of Galeocharax gulo and redescribed. Its inclusion in Galeocharax is justified, and comments on the distribution of the species of this genus are made. The record of Galeocharax gulo in the rio São Francisco is considered a mistake.
New Astyanax from the upper rio Tapajós drainage, Central Brazil (Characiformes: Characidae)
Authors: Bertaco Vinicius A. , Garutti Valdener
Published: September 2007

Astyanax utiariti, new species, is described from the upper rio Tapajós drainage, Mato Grosso, Brazil. Astyanax utiariti has a horizontally oval black humeral spot, a lozenge-shaped caudal-peduncle spot, continuing to the tip of the middle caudal-fin rays, and two brown bars in the humeral region that allows its inclusion in the A. bimaculatus species group. It also possesses a black stripe extending along midlateral body. The new species is distinguished from its congeners by a reticulate scale pattern, a black longitudinal stripe, toothless maxilla, larger dentary teeth and teeth of the inner row of the premaxilla with five to seven cusps, body depth 33.3-39.9% of standard length (SL), head length (HL) 23.9-26.4% of SL, caudal-peduncle depth 12.0-13.4% of SL, orbital diameter 28.5-34.3% of HL, interorbital width 32.7-38.4% of HL, 36-38 perforated scales along the lateral line, and 22-26 branched anal-fin rays.
Knodus shinahota (Characiformes: Characidae) a new species from the río Shinahota, río Chapare basin (Mamoré system), Bolivia
Authors: Ferreira Katiane M. , Carvajal Fernando M.
Published: September 2007

Knodus shinahota, new species, is described from río Shinahota, a tributary of the upper rio Mamoré basin, Província de Tiraque, Cochabamba State, Bolivia. The new species can be distinguished from all congeners except K. chapadae and K. geryi by having six rows of scales between the lateral line and the dorsal-fin origin (vs 4 or 5 rows of scales in the other species). Knodus shinahota differs from K. chapadae by possessing more rows of scales between the lateral line and the pelvic-fin origin (5 vs 3½ or 4, respectively) and more lateral line scales (38-41 vs 36-38, respectively). It differs from K. geryi by possessing more rows of scales between the lateral-line and the pelvic-fin origin (5 vs 4, respectively); fewer branched anal-fin rays (17-20 vs 15-17, respectively), and by lacking the two symmetric, large, dark, blotches on the basal portions of the caudal-fin lobes that characterize K. geryi.
Cytogenetic and comparative morphology of two allopatric populations of Astyanax altiparanae Garutti & Britski, 2000 (Teleostei: Characidae) from upper rio Paraná basin
Authors: Domingues Manoela de S. , Vicari Marcelo R. , Abilhoa Vinícius , Wamser João P. , Cestari Marta M. , Bertollo Luiz A. C. , Almeida Mara C. de , Artoni Roberto F.
Published: September 2007

The recently described fish species, Astyanax altiparanae (tetra) is common in the upper rio Paraná basin, and has been reported in the Iguaçu basin. However, its natural origin in the rio Iguaçu is questionable. In the present work, karyotypical and morphological features of two populations of Astyanax altiparanae from the upper rio Tibagi and upper rio Iguaçu were compared. Both populations showed 2n=50 chromosomes and differences in their karyotype formula, NOR-bearing chromosomes and location of heterochromatin. Morphometric data from both populations were analyzed through free-size canonical variables. Cytogenetic and morphological results were mostly coincident showing exclusive markers that reflect their degree of populational isolation. In addition to other geographic, morphological and molecular data for A. altiparanae populations from the lower rio Iguaçu and rio Paraná tributaries upstream from the Itaipu Dam (South Brazil), the present results indicate that the two populations analyzed in this study belong to different stocks. The presence of this species along the rio Iguaçu basin would be a consequence of a complex and poorly understood evolutionary history.
Fish assemblage structure in tributaries of the Meia Ponte River, Goiás, Brazil
Authors: Fialho Afonso P. , Oliveira Leandro G. , Tejerina-Garro Francisco L. , Gomes Luiz C.
Published: September 2007

This study was conducted in the Meia Ponte River basin, which is located in the Cerrado biome. The objective was to describe the structure of fish assemblages and to evaluate the results with the regard to the position of the tributaries (sampling stations) along the basin. This basin drains 35 municipalities of Goiás State. Springs of the Meia Ponte are located in the district of Itauçu (GO), in the Serra dos Brandões. Two sampling were conducted, one in the rainy season (March/2001) and another in the dry season (August/2001). Thirty sampling sites in tributaries and one in the channel of the Meia Ponte River, in its upper course, were selected to capture fish with dipnets (3 mm mesh) during one hour, along 100-m stretch. Sampling periods (season; rainy and dry) and the categorization according to the distance of the sampling station from the mouth of the Meia Ponte River (position; upper, intermediate and lower) were used to evaluate differences in fish assemblage structure, summarized by a detrended correspondence analysis (DCA), applied on the abundance data matrix, squared root transformed, to eliminate the effect of abundant species. The first two axes were retained for interpretation (eigenvalues = 0.35 and 0.24, for axis 1 and 2, respectively). The two-way ANOVA (factors seasons and positions) identified significant differences (p <0.05) in score averages for axis 1 and 2, for both factors. These results suggest significant differences in fish assemblage structure in the Meia Ponte River basin for the seasons (rainy and dry) and positions (upper, intermediate and lower) studied, in spite of the short spatial scale. These findings demonstrate a great ichthyofauna heterogeneity in the uppermost part of the Paraná River.
Feeding habits of Thoracocharax stellatus (Characiformes: Gasteropelecidae) in the upper rio Tocantins, Brazil
Authors: Netto-Ferreira André L. , Albrecht Míriam P. , Nessimian Jorge L. , Caramaschi Érica P.
Published: September 2007

The silver hatchetfish Thoracocharax stellatus is one of the approximately 200 fish species recorded for the upper rio Tocantins, in the region where it was impounded by the Serra da Mesa hydroelectric dam. Analysis of the stomach contents of 88 specimens revealed a diet consisting almost entirely of insects (99.6%), most of which were terrestrial (87.6%). Ants, beetles, and mayflies were the main food items. Dawn and dusk seemed to be the periods of highest foraging activity for T. stellatus. As a specialist on terrestrial insects, this species has a close connection with the region near the river bank, where prey is provided from the associated riparian vegetation. Despite the impoundment and depletion of the land-water ecotone observed in later stages of reservoir formation, no significant changes in the diet of the few remnant specimens were recorded, which seems to indicate little feeding flexibility. Thus, feeding seemed to be an overriding factor for the displacement of this species after river impoundment.
Comments on the type status of Laemolyta (Characiformes: Anostomidae) specimens described by Garman, 1890 and Borodin, 1931
Authors: Petry Paulo , Mautari Kelly , Menezes Naércio A. , Hartel Karsten
Published: September 2007

The type status of the specimens of the genus Laemolyta described by S. Garman and N. Borodin are reviewed. The species involved were described as Anostomus varius nitens Garman, 1890, A. varius Garman, 1890, A. proximus Garman, 1890, and A. garmani Borodin, 1931. Several lots were subsequently erroneously designated as types and their status are corrected.
Schooling behavior of Mugil curema (Perciformes: Mugilidae) in an estuary in southeastern Brazil
Authors: Carvalho Carolina Delgado de , Corneta Carolina Marocco , Uieda Virginia Sanches
Published: September 2007

Schools of mullets, Mugilidae, are abundant in estuaries and shallow marine waters. We report on the schooling behavior of juvenile white mullet, Mugil curema, in the estuary of the Canto da Paciência stream, in Ubatuba, southeastern Brazil. Schools of small fish (15 to 35 mm TL) were composed of a larger number of individuals (up to a hundred individuals), and were found feeding mainly in shallow nearshore waters, whereas schools of larger fish (40 to 100 mm TL) were observed only in deeper waters. Three patterns of swimming were observed for the schools: stationary feeding, slow movement while searching for food, and rapid displacement. The variations observed in school structure and behavior seem to be related to the balance between predation risk and increasing food intake.
Is fish passage technology saving fish resources in the lower La Plata River basin?
Authors: Oldani Norberto Oscar , Baigún Claudio Rafael Mariano , Nestler John Michael , Goodwin Richard Andrew
Published: September 2007

Over 450 dams have been constructed in the upper Paraná River basin in Brazil during the past 40 years. River regulation by these dams is considered a primary factor in the reduction of fish diversity and depletion of migratory species. In contrast to the upper Paraná Basin, only two large dams (both with upstream fish passage) have been constructed in the lower La Plata River basin. Fishery managers in the lower basin are concerned that existing and planned dams will further deplete populations of migratory fish species that constitute important recreational and commercial fisheries as has occurred in the upper basin. We assessed the sustainability of fisheries in the lower basin in the face of increased river regulation by using literature information to describe the efficiency of the fish passage systems used to mitigate river regulation impacts on fisheries. Our analysis shows that fish passage systems at both lower basin dams, Yacyreta and Salto Grande, fail to transfer sufficient numbers of upstream migrants to sustain populations of migratory species. Fish passage efficiency of target species in the fish elevators at Yacyreta is less than 2%. Fish diversity in the fish elevators is low because about 85% of the fish belong to only three non-migratory species (Pimelodus maculatus, Oxydoras kneri and Rhinodoras dorbignyi). Large migratory species targeted for passage rarely comprise even 5 % of the fish number in the passage system. The two Borland locks at Salto Grande Dam cannot dependably pass large numbers of migratory species because passage efficiency is dependent upon interactions of powerhouse and spillway operation with tailrace elevations. Most species in the Borland system were either a small catfish (Parapimelodus valenciennis) or a engraulid (Lycengraulis grossidens). Again, the targeted migratory species were not abundant in the passage system. We conclude that existing fish passage technology in the lower basin is inadequate and that improved fish passage designs are required to conserve migratory species. These designs must be based on integrated information from geomorphology (habitat), natural fish behavior, fish swimming capabilities, and detailed population studies.
Preliminary study on the application of radio-telemetry techniques to evaluate movements of fish in the Lateral canal at Itaipu Dam, Brazil
Authors: Hahn Lisiane , English Karl , Carosfeld Joachim , Silva Luiz Gustavo Martins da , Latini João Dirço , Agostinho Angelo Antônio , Fernandez Domingo Rodriguez
Published: September 2007

A preliminary study on the application of radio-telemetry techniques to describe the movements of fish in a bypass channel at Itaipu Dam (Paraná River), known as "Canal da Piracema," was carried out between January and February of 2004. Fourteen individuals of six species (Prochilodus lineatus, Leporinus friderici, Schizodon borellii, Pseudoplatystoma fasciatum, Pterodoras granulosus and Cichla kelberi) were intragastrically and surgically radiotagged and monitored by three experimental fixed radio-telemetry stations installed in the upper portion of the Canal. The surgical implantation of transmitters and the anesthesia using clove oil proved to be more efficient and allowed easier handling in comparison to intragastric implantation and electronarcosis immobilization. The use of fixed stations to obtain data was found to be very suitable for tracking movements of several different fish species in the Itaipu lateral channel. Three species (P. granulosus, S. borellii and C. kelberi) moved downstream after release. Two individuals of P. fasciatum and two of P. lineatus migrated upstream, leaving the channel 7 and 10 days and 2 and 24 days after release, respectively. Leporinus friderici was the only species that did not leave the release site until the end of the study period.
Fish ladder of Lajeado Dam: migrations on one-way routes?
Authors: Agostinho Angelo Antônio , Marques Elineide Eugênio , Agostinho Carlos Sérgio , Almeida Deusimar Augusto de , Oliveira Rafael José de , Melo Jussiclene Rodrigues Bezerra de
Published: September 2007

Fish ladders are generally conceived to reestablish connectivity among critical habitats for migratory species, thus mitigating the impacts of the blockage of migration routes by dams. If this management tool is to be meaningful for conserving fish species, it must provide a fully permeable connection and assure both upward and downward movements. However, because reservoirs have very different hydrodynamics than the original river, it is expected that, at least in the inner area, they may constitute an additional barrier to this movement, especially for descending fish. Thus, the present study sought to determine if migratory fish and their offspring disperse downstream from the dam after ascending a ladder and spawning in the upper reaches of a basin. To achieve this purpose, we evaluated the limitation imposed by lentic areas to the descent of eggs, larvae and adults of migratory species; we also determined the abundance and composition of larvae present in the plankton near the dam, and compared the intensity of the upward and downward movements of adult fish. Samples of ichthyoplankton were taken upriver, inside the reservoir, in the river downstream from the dam, and in the forebay of the Lajeado Dam on the Tocantins River (Luis Eduardo Magalhães Hydroelectric Plant), from October, 1999 through September, 2004. The densities of fish ascending and descending the ladder were determined experimentally on eight occasions, from June, 2004 to March, 2005. Due to difficulties in identifying the true fish origin (up or down) in the environments connected by the fish passage system, the evaluation of the distribution of migratory fish in reservoirs was based on the landings of the commercial fishery conducted along the Itaipu Reservoir during the four years preceding (2001 through 2003) the construction of the lateral channel (fish-passage mechanism). Fish eggs and larvae drifting down the Tocantins River did not appear in samples taken in the lower half of the reservoir; those found in water flowing through the spillways, turbines or fish ladder of Lajeado Dam belonged essentially to non-migratory clupeids that spawn in the inner part of the reservoir. In addition, results showed that in a reservoir with no fish-passage mechanism, migrants select habitats that still maintain riverine characteristics, in the upper parts of the impounded area. The downward movements are negligible compared to those upward, in the experiments conducted in the fish ladder. It is concluded, therefore, that the Lajeado fish ladder, and possibly those at other dams, is essentially a one-way route that promotes upstream movements of migrants, without the necessary return of adults or their offspring. Thus, the low permeability of the connections provided by these management tools can drastically increase the level of environmental impact that they were actually intended to reduce.
Swimming performance of the migratory Neotropical fish Leporinus reinhardti (Characiformes: Anostomidae)
Authors: Santos Hersília de Andrade e , Pompeu Paulo dos Santos , Martinez Carlos Barreira
Published: September 2007

The fishways built in Latin America were mainly based on those used in the northern hemisphere for passing salmonids upstream. However, the swimming capacity in terms of speed and endurance is a major factor concerning the design of a fishway, and this information is not available for migratory neotropical fish species. Therefore, studies on swimming performance of neotropical species is fundamental. The aim of this study was to estimate the critical, sustained and prolonged speeds for the piau-três-pintas Leporinus reinhardti, and to evaluate the influence of water temperature on the swimming performance of the species. Variable (increasing) and fixed velocity tests were performed in a respirometer. When compared to other species whose critical speed data are available, the piau showed higher speeds, for a given total length. Fatigue times per prolonged speed class were estimated as well as prolonged speed per fatigue time class. The changing point from sustained to prolonged swimming was estimated to occur approximately at a speed of seven body-lengths per second (1.12 m/s for an individual with 16 cm total length: the first maturation length). In spite of the great swimming performance of piau, the adoption of efficient directives in fishway projects to allow the passage of neotropical ichthyofauna, will depend on a more detailed analysis of the swimming capacity of different species.
Selectivity of fish ladders: a bottleneck in Neotropical fish movement
Authors: Agostinho Carlos Sérgio , Agostinho Angelo Antônio , Pelicice Fernando , Almeida Deusimar Augusto de , Marques Elineide Eugênio
Published: September 2007

Although dozens of fish ladders have been constructed at dams of Brazilian reservoirs, there are few studies evaluating their efficiency as a tool for the conservation of Neotropical ichthyofauna, especially for migratory species. Therefore, the present study evaluated the selectivity of the species that entered and ascended the fish ladder located next to Lajeado Dam (Luis Eduardo Magalhães Hydroelectric Power Plant) on the Tocantins River. Samples were taken monthly from November, 2002 through October, 2003, in the resting pools of the ladder, using cast nets, and in the downstream stretch, using gillnets. The selectivity of the ladder in attracting fish was evaluated by comparing the occurrence, relative abundance, dominance and the congruence of abundance ranks of migratory and non-migratory species in the ladder and in the stretch of river immediately downstream. Species richness and fish abundance in the resting pools were used to evaluate selectivity along the ladder. The effects on selectivity by temporal variations in water level downriver and maximum flow velocity in the fish ladder were also analyzed. Out of the 130 species recorded downriver, 62.3% were caught in the ladder, and migratory species were clearly favored. However, more than 2/3 of the catch belonged to only three species (Rhaphiodon vulpinus, Psectrogaster amazonica and Oxydoras niger). Although the majority of the species that entered the ladder were able to reach its top, there was a sharp reduction in abundance of individuals towards the top. Temporal variations in the water level below the dam influenced richness and abundance of fish concentrated downstream and in the ladder, with lower values during periods of low water. In the ladder, a maximum flow velocity of 2.3 m/s, although also selective, proved to be more appropriate for fish ascension than a velocity of 2.8 m/s. It was concluded that the entry and ascension of the fish in the ladder were not congruent with their proportions in the downriver stretch: fish samples in the ladder were clearly dominated by a few species, including some that do not need to be translocated. Thus, selectivity constitutes an important bottleneck to initiatives for translocating fish aimed at conserving their stocks or biodiversity. It is urgent to review the decision-making process for the construction of fish passages and to evaluate the functioning of those already operating.
Proposal of a sluice-type fish pass
Authors: Haselbauer Matthias A. , Martinez Carlos Barreira
Published: September 2007

One-dimensional design of fish passes often leads to an unsatisfying solution. The problems are due to insufficient, if not completely missing, collaboration between biologists and civil engineers. In the present paper, a new type of fish pass is presented. A labyrinth flux develops in a system of sequential sluices and baffles in between, which uncouple the supercritical flow of the single sluices. A series of biological, hydraulic and numerical experiments was carried out in order to investigate the optimum configuration in terms of geometric issues, regarding the biological needs and performances of organisms to be transported. Following this optimization, fish can control the prevailing flow conditions quite well. Because the air entrainment into the water is avoided, fish perception is not affected. A geometric extension regarding the needs of small fish, bottom fish, and macrozoobenthos decreases the selectivity and predation pressure on them.
“That's Online Writing, Not Boring School Writing”: Writing With Blogs and the Talkback Project
Authors: Witte Shelbie
Published: October 2007

The Talkback Project used blog software to involve eighth‐grade language arts students, preservice teachers, and parents in online discussion of young adult novels and their personal connections with them. The author shares the challenges associated with the project—including the implications of Internet safety and legal concerns associated with technology integration—but argues that classroom blogging provides positive opportunities for students to

Develop their digital fluency

Strengthen traditional literacy skills

Apply real‐life 21st‐century skills in a safe and monitored environment
Supporting Students With Dyslexia at the Secondary Level: An Emotional Model of Literacy
Authors: Long Louise , MacBlain Sean , MacBlain Martin
Published: October 2007

A 13‐year‐old male adolescent with dyslexia was studied to examine how holistic approaches to intervention can foster academic achievement and emotional well‐being. Findings suggest that appropriate strategies can empower learners and raise standards and highlight the importance of teacher empathy in enhancing the quality of the learning environment. This is best achieved through collaborative practice and whole‐school systemic work.

As a follow‐up, a convenience sample of 25 dyslexic adolescents was surveyed to examine perceptions of being dyslexic and evaluations of the learning environment. Results indicated that although study skills are being taught, teachers may lack approachability and empathy. Findings are discussed in the context of the role of teachers in promoting student engagement and enhancing self‐efficacy. Strategies are suggested for empowering learners, promoting self‐esteem, and modifying the learning environment to provide student‐centered, affective, and social‐academic pathways.
“School” Reading and Multiple Texts: Examining the Metacognitive Development of Secondary‐Level Preservice Teachers
Authors: Lesley Mellinee , Watson Patricia , Elliot Susan
Published: October 2007

This practitioner‐research study investigated the reading behaviors of preservice teachers from diverse content disciplines as they engaged in reading multiple texts pertaining to a historical topic. Through participant‐observer field notes, reader response journals, reflective essays, and participant debriefing, the authors examined the metacognitive awareness of students enrolled in a content area literacy course for preservice, secondary‐level teachers.

Results indicated that prospective teachers relied predominantly on a limited number of metacognitive strategies and engaged in reading behavior ranging from skimming and incomplete reading practices to not reading at all. This trend of engaging in less proficient or “pseudo‐reading” strategies points to similarities in the reading behaviors and identities of these preservice teachers and of struggling readers described in many pedagogical theories surrounding content area literacy instruction. This study offers an explanation for the resistance secondary preservice teachers often exhibit toward content area literacy methods.
Why Johnny Can Never, Ever Read: The Perpetual Literacy Crisis and Student Identity
Authors: Williams Bronwyn T.
Published: October 2007

Alarms about a “literacy crisis” among young people have been sounded on a regular basis for more than a century. Yet as each generation of students matures, it is able to accomplish the reading and writing tasks necessary for society to continue. Perhaps then, rather than sounding more alarms, it is time to consider what anxieties, particularly economic anxieties, drive the perpetual literacy crisis. We should consider how these anxieties influence our perceptions of student identities and how best to respond in the classroom.
The Last Night of All
Authors: Wood Michael
Published: October 2007

This is a brief essay about a long or perhaps interminable subject, about what I am (for the moment) calling the genre of the unfinishable work, as distinct from works that are unfinished or open-ended—the work whose themes and style involve what comes last and then what comes after that, if there is anything after that. I thought at first there might be too few of these works to form a genre. Now I am inclined to think there may be too many, but the shift or increase does give us a contrasting term and may help us consider more closely the possibility that lies between insufficiency and excess.
Remapping the Crime Novel in the Francophone Caribbean: The Case of Patrick Chamoiseau's Solibo Magnifique
Authors: Knepper Wendy
Published: October 2007

Shaped by a history of mobilities, displacements, and creolizing processes, the Caribbean is a significant testing ground for theories concerning the circulation and remapping of genre. Taking Patrick Chamoiseau's theory of generic wandering as my point of departure, I argue that his Solibo Magnifique exemplifies the principle of generic creolization. This is evident in the novel's intermixing of the detective novel, film noir, the spaghetti western, the comic book, the hard-boiled crime novel, and creole storytelling techniques. By manipulating the conventions by which the classical detective, the hard-boiled police officer, and the private investigator are characterized, Chamoiseau's narrative turns from an investigation into one man's death to an interrogation of Martinique, its history and the workings of its neocolonial psyche. Through the example of Solibo Magnifique and its radiating influence on other postcolonial crime writers, I conclude that this principle of creative creolization is increasingly relevant to understanding a world in which genre's radiating and rhizomic web of mobilities involves local and global confluences.
Poetry of Politics and Mourning: Mahmoud Darwish's Genre-Transforming Tribute to Edward W. Said
Authors: Dyer Rebecca
Published: October 2007

This essay provides an analysis of “Tibaq,” an elegy written in Edward W. Said's honor by the acclaimed Palestinian poet Mahmoud Darwish. Noting that the poem exhibits aspects of a number of genres and demonstrates Darwish's generally innovative approach to traditional literary forms, I consider how he has transformed the marthiya, the elegiac genre that has been part of the Arabic literary tradition since the pre-Islamic era. I argue that Darwish used the elegy-writing occasion to comment on Said's politics and to make respectful use of his critical methods, particularly his interdisciplinary borrowing of counterpoint, a concept typically used in music analysis. By reworking the conventional marthiya to represent Said's life in exile and his diverse body of work and by putting his contrapuntal method into practice in the conversation depicted in the poem, Darwish elegizes a long-lasting friendship and shores up a shared political cause.
The Polyvalent Discourse of Electronic Music
Authors: SAIBER ARIELLE
Published: October 2007

MIGHT ELECTRONIC MUSIC—A MAJOR FORCE BEHIND CHANGES IN ACOUSTIC TECHNOLOGY, COPYRIGHT LAW, HUMAN-MACHINE INTERface, artistic production, marketing and consumption practices, and global connectivity—help us think about the dizzying proliferation of today's written forms and how we talk about them? It can certainly offer new models and a rich vocabulary for speaking about such things as labeling, canon, and the relationship between author and audience. As “text” continues to bloat, shrink, scatter, and blur, thanks in part to the same digital tools used by contemporary e-music, perhaps looking at how this sound swarm is dealing with its identity will be useful to those who read, write, and write about literature. The essay that follows invites literary scholars to “listen awry” to a wildly polyvalent, indeterminate musical complex that simultaneously lobbies for, rejects, and eludes categorization.
Genre and the Institution of Research: Three American Instances
Authors: Harpham Geoffrey Galt
Published: October 2007

No concept is more fundamental to literary study than genre. It is virtually impossible to think seriously about literature without considering the codes or conventions that structure literary texts. Aristotle's distinction between the “poetic kinds” of epic and drama and Horace's insistence on poetic decorum are early attempts to distinguish among types of creative expression in order to understand and appreciate the specific excellences of each. The most enduring typology of genres divides literature into three classes, depending on who speaks in and therefore controls the work. As M. H. Abrams represents these distinctions, they consist of “lyric (uttered throughout in the first person), epic or narrative (in which the narrator speaks in the first person, then lets his characters speak for themselves); and drama (in which the characters do all the talking).” Other divisions have been proposed (e.g., Northrop Frye's division of comedy, tragedy, irony, and satire), as have more nuanced accounts of genre itself that focus on how genres can cross, mix, and stretch to include deviations from type. But as a means of imposing a preliminary principle of order on an immense and various field, genre is an indispensable concept.
Rho GDP dissociation inhibitor α interacts with estrogen receptor α and influences estrogen responsiveness
Authors: El Marzouk Saad , Schultz-Norton Jennifer R , Likhite Varsha S , McLeod Ian X , Yates John R , Nardulli Ann M
Published: October 2007

Estrogen receptor α (ERα) is a ligand-activated transcription factor that regulates expression of estrogen-responsive genes. Upon binding of the ligand-occupied ERα to estrogen response elements (EREs) in DNA, the receptor interacts with a variety of coregulatory proteins to modulate transcription of target genes. We have isolated and identified a number of proteins associated with the DNA-bound ERα. One of these proteins, Rho guanosine diphosphate (GDP) dissociation inhibitor α (RhoGDIα), is a negative regulator of the Rho family of GTP-binding proteins. In this study, we demonstrate that endogenously expressed RhoGDIα is present in the nucleus as well as the cytoplasm of MCF-7 breast cancer cells, and that RhoGDIα binds directly to ERα, alters the ERα–ERE interaction, and influences the ability of ERα to regulate transcription of a heterologous estrogen-responsive reporter plasmid in transient transfection assays as well as endogenous, estrogen-responsive genes in MCF-7 cells. Our studies suggest that, in addition to the activity of RhoGDIα in the cytoplasm, it also influences ERα signaling in the nucleus.
Benign prostatic hyperplasia (BPH) epithelial cell line BPH-1 induces aromatase expression in prostatic stromal cells via prostaglandin E2
Authors: Wu Quan , Zhou Ying , Chen Linfeng , Shi Jiandang , Wang Chun-Yu , Miao Lin , Klocker Helmut , Park Irwin , Lee Chung , Zhang Ju
Published: October 2007

Estradiol (E2) level in stroma of benign prostatic hyperplasia (BPH) increases with age, and this increase was associated with an elevated expression of aromatase in prostatic stromal cells (PrSCs). Here, we showed that conditioned medium (CM) of BPH-1 (a benign hyperplastic prostatic epithelial cell line), but not of prostate cancer cell lines (LNCaP, DU-145, and PC-3), stimulates aromatase expression in PrSCs. Cyclooxygenase-2 (COX-2) mRNA level in BPH-1, as well as prostaglandin E2 (PGE2) concentration in BPH-1 CM, was significantly higher than that of prostate cancer cell lines. CM of BPH-1 treated with NS-398 (a specific inhibitor of COX-2) failed to stimulate aromatase expression in PrSCs. And PGE2 can stimulate aromatase expression in PrSCs. Our data suggested that BPH-1 induced aromatase expression in PrSCs through the production of PGE2 in a paracrine mechanism.
Effect of nutrition on the GH responsiveness of liver and adipose tissue in dairy cows
Authors: Rhoads R P , Kim J W , Van Amburgh M E , Ehrhardt R A , Frank S J , Boisclair Y R
Published: October 2007

Dairy cows enter a period of energy insufficiency after parturition. In liver, this energy deficit leads to reduced expression of the liver-specific GH receptor transcript (GHR1A) and decreased GHR abundance. As a consequence, hepatic processes stimulated by GH, such as IGF-I production, are reduced. In contrast, adipose tissue has been assumed to remain fully GH responsive in early lactation. To determine whether energy insufficiency causes contrasting changes in the GH responsiveness of liver and adipose tissue, six lactating dairy cows were treated for 4 days with saline or bovine GH when adequately fed (AF, 120% of total energy requirement) or underfed (UF, 30% of maintenance energy requirement). AF cows mounted robust GH responses in liver (plasma IGF-I and IGF-I mRNA) and adipose tissue (epinephrine-stimulated release of non-esterified fatty acids in plasma, IGF-I mRNA, and p85 regulatory subunit of phosphatidylinositol 3-kinase mRNA). Reductions of these responses were seen in the liver and adipose tissue of UF cows and were associated with decreased GHR abundance. Reduced GHR abundance occurred without corresponding reductions of GHR1A transcripts in liver or total GHR transcripts in adipose tissue. In contrast, undernutrition did not alter the abundance of proteins involved in the early post-receptor signaling steps. Thus, a feed restriction reproducing the energy deficit of early lactation depresses GH actions not only in liver but also in adipose tissue. It remains unknown whether a similar reduction of GH action occurs in the adipose tissue of early lactating dairy cows.
Glucocorticoid-induced apoptosis in human decidua: a novel role for 11β-hydroxysteroid dehydrogenase in late gestation
Authors: Chan Junny , Rabbitt Elizabeth H , Innes Barbara A , Bulmer Judith N , Stewart Paul M , Kilby Mark D , Hewison Martin
Published: October 2007

Glucocorticoids play a fundamental role in the endocrinology of pregnancy but excess glucocorticoids in utero may lead to abnormalities of fetal growth. Protection against fetal exposure to cortisol is provided by the enzyme 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) located in the human placental trophoblast. By contrast, relatively little is known concerning the function of glucocorticoid-activating 11β-HSD1, which is strongly expressed within human maternal decidua. To address this we have assessed: i) changes in decidual 11β-HSD1 expression across gestation and ii) the functional role of glucocorticoids in decidua. Human decidua was collected from women undergoing surgical termination of pregnancy in first (n = 32) and second (n = 10) trimesters, and elective caesarean sections in the third trimester (n = 9). Analysis of mRNA for 11β-HSD1 by real-time RT-PCR showed increased expression in second (9.3-fold, P < 0.01) and third (210-fold, P < 0.001) trimesters. Studies using primary cultures of decidual cells also revealed higher levels of cortisol generation in the third trimester. Changes in decidual 11β-HSD1 with gestation were paralleled by increased expression of the apoptosis markers caspase-3 and annexin-V, particularly in cluster designation (CD)10−VE non-stromal cells (20-fold in third trimester relative to first trimester). Apoptosis was also readily induced in primary cultures of third trimester decidual cells when treated with cortisol, cortisone, or dexamethasone (all 100 nM for 24 h). The effect of cortisone but not cortisol or dexamethasone was blocked by an 11β-HSD inhibitor confirming the functional significance of endogenous cortisol generation. These data show that autocrine metabolism of glucocorticoids is an important facet of the feto-placental unit in late gestation and we propose that a possible effect of this is to stimulate programmed cell death in human decidua.