bluuebunny/crossref_metadata_2025 huggingface dataset:
The hydraulic management of the Barra Bonita reservoir (SP, Brazil) as a factor influencing the temporal succession of its fish community
Authors: Petesse ML. , Petrere Jr. M. , Spigolon RJ.
Published: December 2007

The temporal succession of fish communities allows evaluating the environmental conditions and the adaptation capacity of the fish species to anthropogenic stress in reservoirs. The fish community at Barra Bonita reservoir was sampled in two different periods of the year (dry and rainy) and in three different areas of the reservoir (fluvial, transition, and lentic). The species list was compared to another four lists, trying to detect the transformations of the fish community for the last 15 years. In order to evaluate the adaptation of the present fish community to the hydraulic management of reservoir, the trophic and reproductive structures were studied. Temporal succession analysis shows little change in fish richness of the communities. The number of fish species varies between 23 and 39 for a total of 68 registered species. From this, 27 can be considered constant, 14 accessory and 27 accidental; the main differences observed were for Anostomidae, Loricariidae and Characidae families. In relation to the hydraulic management, we found a fish community stabilized and adapted to environmental stress. This is characterized by the dominance of small-sized fish species of opportunistic diet and high reproductive compensation (r-strategists). The overlap of biological cycles of the most abundant species with the reservoir level fluctuations points to the period from September to March-April as critical for reproductive success and only the species with partial reproductive strategy or parental care are best succeeded. These results, interpreted in the context of the reservoir aging process, indicate that Barra Bonita reservoir is entering a transition phase, between the colonization and aging stages.
The feeding activity of Colossoma macropomum larvae (tambaqui) in fishponds with water hyacinth (Eichhornia crassipes) fertilizer
Authors: Sipaúba-Tavares LH. , Braga FMS.
Published: December 2007

Analysis of macrophyte water hyacinth (Eichhornia crassipes) as an organic fertilizer of Colossoma macropomum (tambaqui) larvae in ponds is provided. Water hyacinth produce an organic fertilizer at the ratio of 100 g.m-2 in tambaqui ponds. Two groups of 5,000 larvae were transferred to two fishponds with and without water hyacinth fertilizer and reared until day 43. The fertilized pond evidenced more plankton abundance during the entire production period when compared with the control pond (P < 0.001). The phytoplankton community in the pond was not significantly different than in gut contents (P > 0.05) in both ponds (with and without organic fertilizer). Fish larvae failed to show any preference or selectivity in relation to the different algae (P > 0.01) in the pond, but exhibited high ingestion selectivity for zooplankton (P < 0.05). Application of fertilizer increased (P < 0.05) the abundance of phytoplankton and zooplankton in the treatment pond. Since water hyacinth fertilizer is quite cheap and easily available, it may be conveniently used to enhance fish yield in ponds.
Feeding ecology of a nocturnal invasive alien lizard species, Hemidactylus mabouia Moreau de Jonnès, 1818 (Gekkonidae), living in an outcrop rocky area in southeastern Brazil
Authors: Rocha CFD. , Anjos LA.
Published: December 2007

We studied in fieldwork, the feeding ecology of a Hemidactylus mabouia population from southeastern Brazil throughout one year in a region with marked climatic seasonality. A sampling of availability of arthropods in the environment was carried out, which evidenced that the availability of food resources influenced the composition of the diet of H. mabouia. There were no seasonal differences on diet composition, which may be due to the relatively constant availability on prey throughout the year. In general, this population can be classified as generalist and opportunistic regarding diet. There was a high food niche overlap among juveniles and adults, although juvenile lizards tend to eat higer number of prey (but in lower volume) when compared to adult lizards. The ability to exploit a wide array of prey in an efficient way, maintaining a positive energetic balance, may be a factor determining the efficiency of this exotic species to occupy invaded areas.
Reproduction of Pirapitinga do Sul (Brycon opalinus Cuvier, 1819) in the Parque Estadual da Serra do Mar-Núcleo Santa Virgínia, São Paulo, Brazil
Authors: Gomiero LM. , Braga FMS.
Published: December 2007

The objective of the study was to characterize seasonally and locally the reproduction of Pirapitinga do Sul (Brycon opalinus). The study area included three rivers (Paraibuna, Ipiranga, and Grande) in the Santa Virgínia Unit of the Serra do Mar State Park, State of São Paulo, Brazil. Breeding occurred in spring, summer, and autumn. The L50 and the L100 of this species were 16 to 18 cm and 26 to 28 cm, respectively. Spawning was total, with synchronous development in two groups. The size of mature oocytes was 1,346.4 µm, reaching a maximum of 2,570.4 µm, with a mean fecundity of 9,190.5 oocytes. This species has external fertilization, is non-migratory, and lacks parental care of the young. Preservation of the Pirapitinga do Sul depends, in great part, on maintaining water quality, preservation of the riverine forests, and access to breeding areas.
Calosotomia em paciente com epilepsia generalizada primária e crises tônico-clônicas generalizadas refratárias: relato de caso
Authors: Pereira Alessandra Marques , Souza Victor , Palmini André , Azambuja Ney , Torres Carolina Machado , Martinez José Victor , Costa Jaderson Costa da
Published: December 2007

INTRODUÇÃO: Pacientes com epilepsia generalizada primária (idiopática) podem, raramente, não responder ao tratamento medicamentoso e assim apresentar crises tônico-clônicas generalizadas (CTCG) recorrentes, incapacitantes e que colocam o paciente em risco de complicações graves. OBJETIVO: Nesse artigo é relatado o caso de um paciente com epilepsia generalizada primária e CTCG semanais, refratárias a diversos esquemas medicamentosos, que foi submetido a uma calosotomia. RESULTADO: No curto espaço de 3 meses de seguimento pós-operatório, o paciente não mais apresentou CTCG. CONCLUSÃO: A calosotomia pode ser um procedimento útil na redução da freqüência de CTCG refratárias, mesmo em pacientes com epilepsia generalizada primária.
Ação educativa de professores de ensino fundamental sobre epilepsia na periferia do município de São Paulo: união de extremos especialistas e educadores
Authors: Guilhoto Laura Maria de Figueiredo Ferreira , Nobre Cássia , Silva Arthur Raymundo Chaves Oliveira , Tavares Carlos
Published: December 2007

INTRODUÇÃO: A epilepsia afeta aproximadamente 2% da população mundial e há pouca divulgação pública de informações sobre o tema, tornando-se importante a apresentação do assunto às comunidades, especialmente no âmbito escolar, onde as crianças permanecem boa parte do seu tempo. O objetivo deste estudo foi aplicar em uma escola municipal de ensino fundamental de Guaianases, um dos bairros mais pobres da periferia do município de São Paulo, questionário sobre epilepsia dentro do projeto "Epilepsia na Escola e a ação do professor" da Associação Brasileira de Epilepsia (ABE). MÉTODOS: O questionário foi elaborado pela ABE envolvendo: conceituação e definição da epilepsia; causas; efeitos das drogas antiepilépticas; atividades da pessoa com epilepsia; e finalmente cuidados durante a crise epiléptica. O questionário com 21 questões foi aplicado antes de aula (fase 1) sobre o tema "Epilepsia para professores", e 2 meses após (fase 2). RESULTADOS: Houve acerto das questões em mais de 70% dos entrevistados na fase 1, em 13 de 21 questões, e na fase 2, em 17 de 21 questões. CONCLUSÕES: Observamos nesse estudo que professores de uma escola de uma das regiões mais pobres do município de São Paulo apresentavam conhecimentos básicos sobre epilepsia, que puderam ser incrementados após aula específica da Associação Brasileira de Epilepsia.
Two new species of Astyanax (Ostariophysi: Characiformes: Characidae) from eastern Brazil, with a synopsis of the Astyanax scabripinnis species complex
Authors: Bertaco Vinicius A. , Lucena Carlos A. S. de
Published: December 2007

Two new species of Astyanax are described from eastern Brazil: A . microschemos from the córrego Palmital, rio Itapemirim drainage, Espírito Santo, and A . pelecus from the rio Pardo drainage, Bahia. Astyanax microschemos differs from its congeners by its shallower body depth, 26.9-29.7% of standard length, the presence of one vertically elongate humeral spot that extend above and below the lateral line, smaller interorbital width, 26.9-30.4% of head length, and the possession of 14-18 branched anal-fin rays. Astyanax pelecus differs from its congeners in the possession of only one humeral spot limited to the region dorsal to the lateral line, conspicuous, dark, midlateral body stripe extending from the upper margin of the opercle to the caudal-fin base, a shallower body depth, 26.7-34.8% of standard length, and the possession of 16-18 branched anal-fin rays, 38-39 scales in the lateral-line series, and four scales between the lateral line and the pelvic-fin origin. Astyanax microschemos has a massive head, short snout, usually smaller than the orbital diameter, shallow body depth, and vertically-elongate humeral spot that serve to include it in the A . scabripinnis species complex. A comparative synopsis of this complex is provided.
Food spectrum and trophic structure of the ichthyofauna of Corumbá reservoir, Paraná river Basin, Brazil
Authors: Luz-Agostinho Karla D. G. , Bini Luis M. , Fugi Rosemara , Agostinho Angelo A. , Júlio Jr. Horácio F.
Published: December 2007

In this paper we evaluate plasticity of fish concerning diet. We expect that sampling over a large temporal and spatial scale, including environmental changes such as impoundments, will allow us to cover most of the diet plasticity. We also evaluate the efficacy of ordination method in discriminating trophic groups based on fish species diet. Data were obtained from 17 sampling stations sampled monthly from March/96 to February/99 in the Corumbá river drainage, before and after the formation of the Corumba reservoir. Diet was determined analysing 9,177 stomach contents from 64 fish species. Trophic categories were discriminated by a non-hierarchic grouping analysis named k-means, applied to diet data. Most of the species presented great trophic plasticity, eating a great variety of food items. Resources availability, estimated from all fish stomach contents, was similar among environments, except in creeks, where it varied more with a large importance of terrestrial insects. K-means present satisfactory results, identifying nine trophic groups (detritivores, herbivore-piscivores, insectivore-herbivores, omnivores, invertivores, aquatic insectivores, piscivore-insectivores, piscivores and herbivores).
Reproductive success and female preference in the amazonian cichlid angel fish, Pterophyllum scalare (Lichtenstein, 1823)
Authors: Cacho Maria do Socorro R. F. , Chellappa Sathyabama , Yamamoto Maria Emília
Published: December 2007

The angel fish, Pterophyllum scalare is a cichlid native to the Amazon Basin of Brazil and is exported as an ornamental fish. In this study the importance of the experience and previous reproductive success of males in mate selection was investigated. In order to investigate reproductive experience, six pairs of males (experienced and inexperienced) and six females were used. Males were placed in an aquarium, where one female was released. Mate selection was verified by the time spent by a female near one of the males. To evaluate reproductive success, six pairs of males were tested, each pair consisting of a successful male and an unsuccessful one. Again, time spent with one of the males was considered as an indication of preference by the female. Each female was then paired with an unsuccessful male and their reproductive success was assessed. Females preferred larger, aggressive, territorial and experienced males. Correlations between male aggressiveness, aeration and egg survival were significant. During larval care, male aggressiveness was significantly related to larvae survival. Furthermore, intrabucal care and larval survival showed significant correlations with care provided by the experienced, mated and isolated fish. Survival of offspring resulted from mating with experienced and inexperienced males showed significant differences. Correlations between time spent by females with successful males during reproduction and survival rate of eggs and larvae were significant. Females assess the capacity and willingness of males in investing efforts to raise the offspring through their courtship behavior. Experienced and successful males are preferred by females and thereby achieve greater reproductive success.
Karyotype description of three species of Loricariidae (Siluriformes) and occurrence of the ZZ/ZW sexual system in Hemiancistrus spilomma Cardoso & Lucinda, 2003
Authors: Oliveira Renildo Ribeiro de , Souza Issakar Lima , Venere Paulo Cesar
Published: December 2007

The neotropical freshwater systems have a high number of catfish species (Siluriformes), and many of those are denominated "cascudos" in Brazil. Cytogenetic data about three "cascudos" species fished in the rio Araguaia are described in the present study. The Pterygoplichthys joselimaianus showed 2n=52, with 28 metacentrics (M) chromosomes, 16 submetacentrics (SM) and 8 subtelocentrics/acrocentrics (ST/A) in both sexes. Hemiancistrus spinosissimus showed 2n=52, with karyotype formulae 26M+22SM+4ST, in both sexes. Hemiancistrusspilomma also showed 2n=52, but in this species a ZZ/ZW sex chromosome system (25M+21SM+6ST in females and 24M+22SM+6ST in males) was observed. The cells from H. spinosissimus and P. joselimaianus showed one chromosome pair bearing Ag-NORs, while in the H. spilomma three chromosome pairs bearing Ag-NORs were detected. The data showed in this work reveal particular chromosomal characteristics, important for a good recognition of both Hemincistrus species, and also show the importance of the insertion of cytogenetic data on taxonomic phylogenetic studies.
Turtle riders: remoras on marine turtles in Southwest Atlantic
Authors: Sazima Ivan , Grossman Alice
Published: December 2007

An overview is presented for a poorly documented relationship between reef vertebrates in Southwest Atlantic: remoras (Echeneidae) associated with marine turtles. Two remora species (Echeneis naucrates and Remora remora) and four turtle species (Caretta caretta, Chelonia mydas, Eretmochelys imbricata, and Dermochelys coriacea) are here recorded in symbiotic associations in the SW Atlantic. Echeneis naucrates was recorded both on the coast and on oceanic islands, whereas R. remora was recorded only at oceanic islands and in the open sea. The remora-turtle association is usually regarded as an instance of phoresis (hitchhiking), albeit feeding by the fish is also involved in this symbiosis type. This association seems to be rare in SW Atlantic.
Cruciglanis, a new genus of Pseudopimelodid catfish (Ostariophysi: Siluriformes) with description of a new species from the Colombian Pacific coast
Authors: Ortega-Lara Armando , Lehmann A. Pablo
Published: December 2007

Cruciglanis pacifici, gen. et sp. nov., is described from the Dagua and Anchicaya Rivers on the Pacific slope of Colombia. The new genus is differentiated from the other genera in the family by the presence of an ossified crucifix-shaped second basibranchial; ectopterygoid bone shaped as an inverted comma, with its distal end narrow and directed medially towards the mesopterygoid; anterior fontanel elongated, reaching a transverse line at sensory canal opening of the sphenotic bone; caudal fin emarginated with rounded edges and ventral lobe more developed than the dorsal lobe; caudal fin with a dark spot from its base and fused with the peduncular spot, covering the anterior three quarters of its length, distal rim totally hyaline. Coloration of the species is described in vivo, and the shared diagnostic characters with the other genera within the Pseudopimelodidae are discussed. The phylogenetic position of the new genus is proposed and new insights in the family interrelationships are presented.
Testing the ecomorphological hypothesis in a headwater riffles fish assemblage of the rio São Francisco, southeastern Brazil
Authors: Casatti Lilian , Castro Ricardo M. C.
Published: December 2007

The ecomorphology of 14 fish species resident in a headwater riffles area of the São Francisco river, southeastern Brasil, was analyzed and combined with diet and feeding behavior data, previously obtained by us. The three larger species groups formed in the ecomorphological analysis were found to reflect primarily microhabitat occupation in the following manner: a) nektonic characids with compressed bodies, lateral eyes and lateral pectoral fins, with diurnal and opportunistic feeding habits (Astyanax rivularis, Bryconamericus stramineus, and Bryconamericus sp.); b) nektobenthic characiforms and siluriforms with fusiform bodies and expanded pectoral fins, including sit-and-wait characidiins, predators of aquatic insect larvae (Characidium fasciatum and Ch.zebra), as well as the algae grazing parodontids (Apareiodon ibitiensis and Parodon hilarii), and also the heptapterid and trichomycterid catfishes that practice substrate speculation and feed on benthic aquatic insect larvae (Cetopsorhamdia iheringi, Imparfinis minutus, Rhamdia quelen, and Trichomycterus sp.); c) benthic species with depressed bodies, suctorial oral discs, dorsal eyes, and horizontal pectoral fins, represented by the periphytivorous loricariid catfishes (Hisonotus sp., Harttia sp., and Hypostomus garmani). Correlation between diet and general morphology was not significant in our analysis, unless when the analyzed set included only nektonic and benthic species, indicating that the lack of correlation between these factors is most pronounced in the group of nektobenthic species. The unequivocal case of morphological convergence found between the nektobenthic Characidiinae and Parodontidae is a clear example of the integration between phylogenetic information and ecomorphology, and provides a way to objectively identify cases of morphological and adaptive convergence and divergence. Furthermore, the general congruence between the ecomorphological results and the independently obtained ecological data about the analyzed fish species in their natural environment seems to be strong evidence in favor of the proposed predictive capabilities of the ecomorphological hypothesis.
Chromosomal characterization of the bonytongue Arapaima gigas (Osteoglossiformes: Arapaimidae)
Authors: Marques Debora Karla , Venere Paulo Cesar , Galetti Junior Pedro Manoel
Published: December 2007

The mitotic chromosomes of the pirarucu Arapaima gigas inhabiting the middle Araguaia River and collected in the municipality of Araguaiana (MT, Brazil) were studied. The chromosomes were analyzed through Giemsa staining, C-banding, Ag-NOR staining and in situ hybridization using an 18S rRNA gene probe. The karyotype had 2n=56 comprising 14 biarmed and 14 uniarmed chromosome pairs in both sexes. No cytologically distinguishable sex chromosome was identified. A single NOR-bearing chromosome pair was detected by Ag-NOR staining and confirmed by 18S rDNA- FISH. Faint constitutive heterochromatin was C-banded in the centromeric region of some chromosomes.
Collaborative monitoring of the ornamental trade of seahorses and pipefishes (Teleostei: Syngnathidae) in Brazil: Bahia State as a case study
Authors: Rosa Ierecê L. , Sampaio Cláudio L. S. , Barros Adrianne T.
Published: December 2007

Many species of seahorses and pipefishes (family Syngnathidae) are traded for medicinal purposes and aquaria; some are also sold as souvenirs or curiosities. Brazil is one of the main suppliers of seahorses for the international aquarium trade, nevertheless, little is known about the magnitude of that trade in the country. With regards to pipefishes, virtually nothing is known about their captures for ornamental purposes in Brazil. The present study assesses the magnitude of captures and trade of seahorses and pipefishes, based on data obtained through a collaborative monitoring program established with the main retailer of marine ornamental organisms in the State of Bahia. The syngnathid fishery is conducted in shallow waters never exceeding 7 m, generally by breathhold diving. Both seahorses and pipefishes are mostly caught by hand, and only rarely hand-nets or plastic bags are used. From January/1997 to June/2005, 152 fishers recorded their daily catches of syngnathids. Two species of seahorses, Hippocampus reidi and H. cf. erectus (9,793 specimens captured from 1997 to 2005) and three species of pipefishes, Cosmocampus albirostris, Micrognathus sp. and Syngnathus sp. (143 specimens captured from 1999 to 2005) were traded. H. reidi was the most heavily exploited species.
Modeling energy flow in a large Neotropical reservoir: a tool do evaluate fishing and stability
Authors: Angelini Ronaldo , Agostinho Angelo Antonio , Gomes Luiz Carlos
Published: December 2007

Recently, there is an increasing perception that the ecosystem approach gives important insights to support fisheries stock assessment and management. This paper aims to quantify energy flows in the Itaipu Reservoir (Brazil) and to simulate increase of the fishing effort of some species, using Ecopath with Ecosim software, which could allow inferences on stability. Therefore, two steady-state Itaipu models were built (1983-87 and 1988-92). Results showed that: a) there are no differences between models, and results on aging trends do not vary over time indicating that fishery does not alter the ecosystem as a whole; b) results of fisheries simulations are approximate to mono-specific stock assessment for the same species and periods; c) many authors believe that tropical ecosystems are environments where biotic and abiotic oscillations are annual and sometimes unexpected, but the results found for the Itaipu Reservoir indicate that stability was met after 16 years.
Comparing on site human and video counts at Igarapava fish ladder, south eastern Brazil
Authors: Bowen Mark D. , Marques Simone , Silva Luiz G. M. , Vono Volney , Godinho Hugo P.
Published: December 2007

On site human observations and video images were collected and compared at the window of the Igarapava Dam fish ladder (IDFL), rio Grande , Southeastern Brazil, between March 1st and June 30th, 2004. We conducted four experiments with two humans (Observer 1 and Observer 2) observing fish passage in the IDFL window while a Sony 3CCD video camera (Observer 3) recorded fish passage at the same time. Experiments, each one hour in length, were distributed throughout the diel cycle using full spectrum lights. We identified fish species, the number of individuals for each species, and the real time that they passed. Counts from each human observer were compared to the video counts. The fish species most commonly observed in the window were - curimba (Prochilodus lineatus), mandi-amarelo (Pimelodus maculatus), piau-três-pintas (Leporinus friderici) and ferreirinha (Leporinus octofasciatus). The number of species and individuals were indistinguishable for the three observers. But, the number of species and individuals were significantly different among experiments. Thus, the three observers register the same number of species and count the same number of individuals even when these two response variables differ significantly among experiments. Based on these results, we concluded that the video count was an accurate method to assess fish passage at the IDFL.
15N‐NITRATE SIGNATURE IN LOW‐ORDER STREAMS: EFFECTS OF LAND COVER AND AGRICULTURAL PRACTICES
Authors: Lefebvre S. , Clément J.-C. , Pinay G. , Thenail C. , Durand P. , Marmonier P.
Published: December 2007

Many studies have shown that intensive agricultural practices significantly increase the nitrogen concentration of stream surface waters, but it remains difficult to identify, quantify, and differentiate between terrestrial and in‐stream sources or sinks of nitrogen, and rates of transformation. In this study we used the δ15N‐NO3 signature in a watershed dominated by agriculture as an integrating marker to trace (1) the effects of the land cover and agricultural practices on stream‐water N concentration in the upstream area of the hydrographic network, (2) influence of the in‐stream processes on the NO3‐N loads at the reach scale (100 m and 1000 m long), and (3) changes in δ15N‐NO3 signature with increasing stream order (from first to third order). This study suggests that land cover and fertilization practices were the major determinants of δ15N‐NO3 signature in first‐order streams. NO3‐N loads and δ15N‐NO3 signature increased with fertilization intensity. Small changes in δ15N‐NO3 signature and minor inputs of groundwater were observed along both types of reaches, suggesting the NO3‐N load was slightly influenced by in‐stream processes. The variability of NO3‐N concentrations and δ15N signature decreased with increasing stream order, and the δ15N signature was positively correlated with watershed areas devoted to crops, supporting a dominant effect of agriculture compared to the effect of in‐stream N processing. Consequently, land cover and fertilization practices are integrated in the natural isotopic signal at the third‐order stream scale. The GIS analysis of the land cover coupled with natural‐abundance isotope signature (δ15N) represents a potential tool to evaluate the effects of agricultural practices in rural catchments and the consequences of future changes in management policies at the regional scale.
MODELING SPAWNING DATES OFHUCHO TAIMENIN MONGOLIA TO ESTABLISH FISHERY MANAGEMENT ZONES
Authors: Vander Zanden M. Jake , Joppa Lucas N. , Allen Brant C. , Chandra Sudeep , Gilroy David , Hogan Zeb , Maxted Jeffrey T. , Zhu Jun
Published: December 2007

The ecological impacts of recreational fisheries are of growing concern and pose a number of unique management challenges. Here we report on our efforts to provide guidance for managing a recreational fishery for taimen, the giant Eurasian trout (Hucho taimen) in Mongolia. This species has declined dramatically across its range of Siberia and Central Asia, and is currently listed as endangered in Mongolia. Strong populations persist in remote regions of Mongolia because of limited anthropogenic impacts and harvest, though interest in the fishery is expanding rapidly. Current fishing regulations list the spring “opening date” for taimen fishing as 15 June, although regulations have not been consistently enforced, partially because taimen spawn much earlier than 15 June in much of the country. Through a combination of statistical models, climate data, knowledge of taimen biology, and geographic information systems (GIS), we model taimen spawning dates for potential habitat in Mongolia. A parametric bootstrap procedure was used to simulate variability in spawning date derived from inter‐annual climate variability and model error, from which we estimated the date in which taimen spawning is predicted to occur with 90% confidence. We recommend the designation of three fisheries management zones, with corresponding opening dates of 20 May, 1 June, and 15 June. Our fishery opening date recommendations are less restrictive than existing regulations. Provided there is little or no catch‐and‐release fishing mortality, this approach serves both environmental and human needs by protecting taimen during the reproductive period, while still allowing a post‐spawning catch‐and‐release fishery that benefits local economies and generates revenue (through fishing concession fees) for local conservation efforts.
SIZE‐SELECTIVE HARVESTING ALTERS LIFE HISTORIES OF A TEMPERATE SEX‐CHANGING FISH
Authors: Hamilton Scott L. , Caselle Jennifer E. , Standish Julie D. , Schroeder Donna M. , Love Milton S. , Rosales-Casian Jorge A. , Sosa-Nishizaki Oscar
Published: December 2007

Selective mortality, whether caused naturally by predation or through the influence of harvest practices, initiates changes within populations when individuals possessing certain heritable traits have increased fitness. Theory predicts that increased mortality rates will select for changes in a number of different life history characteristics. For example, fishing often targets larger individuals and has been shown repeatedly to alter population size structure and growth rates, and the timing of maturation. For sex‐changing species, selective fishing practices can affect additional traits such as the mature population sex ratio and the timing of sexual transformation. Using historical comparisons, we examined the effects of exploitation on life history characteristics of California sheephead, Semicossyphus pulcher, a temperate protogynous (female–male sex changer) labrid that inhabits nearshore rocky environments from central California, USA, to southern Baja California, Mexico. Recreational fishing intensified and an unregulated commercial live‐fish fishery developed rapidly in southern California between the historical and current studies. Collections of S. pulcher from three locations (Bahía Tortugas, Catalina Island, and San Nicolas Island) in 1998 were compared with data collected 20–30 years previously to ascertain fishery‐induced changes in life history traits. At Bahía Tortugas, where fishing by the artisanal community remained light and annual survivorship stayed high, we observed no changes in size structure or shifts in the timing of maturation or the timing of sex change. In contrast, where recreational (Catalina) and commercial (San Nicolas) fishing intensified and annual survivorship correspondingly declined, males and females shifted significantly to smaller body sizes, females matured earlier and changed sex into males at both smaller sizes and younger ages and appeared to have a reduced maximum lifespan. Mature sex ratios (female : male) increased at San Nicolas, despite a twofold reduction in the mean time spent as a mature female. Proper fisheries management requires measures to prevent sex ratio skew, sperm limitation, and reproductive failure because populations of sequential hermaphrodites are more sensitive to size‐selective harvest than separate‐sex species. This is especially true for S. pulcher, where different segments of the fishery (commercial vs. recreational) selectively target distinct sizes and therefore sexes in different locations.
AGE‐STRUCTURED MODELING REVEALS LONG‐TERM DECLINES IN THE NATALITY OF WESTERN STELLER SEA LIONS
Authors: Holmes E. E. , Fritz L. W. , York A. E. , Sweeney K.
Published: December 2007

Since the mid‐1970s, the western Steller sea lion (Eumetopias jubatus), inhabiting Alaskan waters from Prince William Sound west through the Aleutian Islands, has declined by over 80%. Changing oceanographic conditions, competition from fishing operations, direct human‐related mortality, and predators have been suggested as factors driving the decline, but the indirect and interactive nature of their effects on sea lions have made it difficult to attribute changes in abundance to specific factors. In part, this is because only changes in abundance, not changes in vital rates, are known. To determine how vital rates of the western Steller sea lion have changed during its 28‐year decline, we first estimated the changes in Steller sea lion age structure using measurements of animals in aerial photographs taken during population surveys since 1985 in the central Gulf of Alaska (CGOA). We then fit an age‐structured model with temporally varying vital rates to the age‐structure data and to total population and pup counts. The model fits indicate that birth rate in the CGOA steadily declined from 1976 to 2004. Over the same period, survivorship first dropped severely in the early 1980s, when the population collapsed, and then survivorship steadily recovered. The best‐fitting model indicates that in 2004, the birth rate in the central Gulf of Alaska was 36% lower than in the 1970s, while adult and juvenile survivorship were close to or slightly above 1970s levels. These predictions and other model predictions concerning population structure match independent field data from mark–recapture studies and photometric analyses. The dominant eigenvalue for the estimated 2004 Leslie matrix is 1.0014, indicating a stable population. The stability, however, depends on very high adult survival, and the shift in vital rates results in a population that is more sensitive to changes in adult survivorship. Although our modeling analysis focused exclusively on the central Gulf of Alaska, the western Gulf of Alaska and eastern Aleutians show a similar pattern of declining pup fraction with no increase in the juvenile, or pre‐breeding, fraction. This suggests that declining birth rate may be a problem for western Steller sea lions across the Gulf of Alaska and into the Aleutian Islands.
The ‘Regulatory’ State and the Use of ‘Independent’ Agencies as Legitimising Mechanisms of Educational Reform
Authors: Gouvias Dionyssios
Published: December 2007

The emergence – at the dawn of the new millennium – of ‘independent agencies’, ‘national commissions’ and ‘councils’ around the world, has been based and justified on grounds of ‘impartiality’, ‘reliability’, ‘democratic-principles guardianship’, or even ‘technical competence’. These ‘independent’ agencies are compared to state agencies, which traditionally have been responsible for the formulation of education policies. By using analytic tools from the Marxist, as well as from the neo-Weberian theoretical traditions, it is argued that the constitution of these new ‘independent agencies’ is a response to the post-modern State (what the author calls the ‘regulatory State’) legitimacy crisis. By including representatives from various interest parties, the dominant interests within the State mechanisms –always in accordance with the current power balance in the various social fields– vest the inherently unequal social relations with the magic cloak of ‘social partnership’.
Technical and Vocational Education in Cameroon and Critical Avenues for Development
Authors: Che S. Megan
Published: December 2007

Technical and vocational education (TVE) can influence development and economic progress for post-colonial societies. Some newly independent sub-Saharan African countries attempted curricular transformation that might produce a skilled workforce through widespread access to versions of TVE. In Cameroon, no such post-colonial curricular revolution was enacted. This article qualitatively analyzes fourteen Cameroonian secondary mathematics teachers' spontaneous discussions about the possibilities and perceived necessity for increased TVE avenues in Cameroon. Relationships between TVE, the problem of educated unemployed, the public and private sectors, and development are explored. This article views teachers' discussions from a lens of critical theory.
Audit Fees and Auditor Dismissals in the Sarbanes-Oxley Era
Authors: Ettredge Michael L. , Scholz Susan , Li Chan
Published: December 2007

The accounting scandals and Sarbanes-Oxley Act (SOX) of 2002 resulted in large increases in required audit work, and corresponding increases in audit fees for public companies. This study provides early evidence regarding the relationship between higher audit fees, both levels and changes, and auditor dismissals in the period immediately subsequent to the passage of SOX. We find that clients paying higher fees are more likely to dismiss their auditors. We also find that dismissals are associated with smaller companies, companies with going-concern reports, and companies that later reported material weaknesses in their internal controls. Among dismissing clients, smaller Big 4 clients, paying higher fees, tend to hire non-Big 4 successor auditors. This result holds when auditors are divided into Big 4, national, and local tiers. We also find evidence that dismissing clients, in particular clients hiring new non-Big 4 auditors, experience smaller fee increases than nonswitching clients in the following year. These results are consistent with the notion that in the immediate post-SOX period, some companies dismissed their auditors in expectation of lower fees from the succeeding auditor.
Do Clients Share Preparers' Self-Assessment of the Extent to Which They Advocate for Their Clients?
Authors: Stephenson Teresa
Published: December 2007

A conflict between the tax preparation services that tax preparers provide and the services taxpayers seek is demonstrated in the literature: tax professionals equate client advocacy with aggressive tax positions while taxpayers hire preparers to increase accuracy and reduce the probability of tax audit. Although this difference has been demonstrated at the large firms, more than half of tax preparers are at regional and local firms. This study examines tax preparers, self-employed or from local and regional firms, and their clients using an established scale—the recently developed Mason–Levy Advocacy Scale. This research measures the understanding taxpayers have of their tax preparers' self-assessed levels of client advocacy. A practically small but statistically significant difference is found. Advocacy is found to be equal between CPAs and non-CPAs—counter to prior research. Also, CPA clients and non-CPA clients are found to have similar perceptions regarding the aggressiveness of their preparers. The implications to practice are that more conservative tax preparation may satisfy clients with less risk and cost. Additionally, less aggressive tax positions will help to close the tax gap.
Auditors' Identification with Their Clients and Its Effect on Auditors' Objectivity
Authors: Bamber E. Michael , Iyer Venkataraman M.
Published: December 2007

This study empirically models auditors' relationships with their clients. The Independence Standards Board (ISB 2000) identified auditors' familiarity with the client as one of five threats to auditor independence. Yet familiarity with the client is necessary for auditors to understand the client well enough to plan and perform an effective and efficient audit. We introduce a theory-based measure of the extent to which auditors identify with a client, which we then use to directly measure auditors' attachment to the client and the threat of this attachment to auditors' objectivity. The responses of 252 practicing auditors support our theoretical predictions. Specifically, we find that auditors do identify with their clients and that auditors who identify more with a client are more likely to acquiesce to the client-preferred position. On the other hand, more experienced auditors and auditors who exhibit higher levels of professional identification are less likely to acquiesce to the client's position.
Big 4 Audit Fee Premiums for National and Office-Level Industry Leadership in the United Kingdom
Authors: Basioudis Ilias G. , Francis Jere R.
Published: December 2007

The pricing of Big 4 industry leadership is examined for a sample of U.K. publicly-listed companies, and adds to the evidence from the Australian and U.S. audit markets that city-specific industry leadership commands a fee premium. There is a significant fee premium for city-specific industry leaders relative to other Big 4 auditors, but no evidence that either the top-ranked or second-ranked firm nationally commands a fee premium relative to other Big 4 auditors, after controlling for city-level industry leadership. We also test for Big 4 fee premiums relative to non-Big 4 auditors and the U.K. data suggest a three-level hierarchy based on audit fee differentials: (1) Big 4 city-specific industry leaders have the largest fees; (2) other Big 4 auditors (noncity leaders) and second-tier national firms have comparable fees that are lower than Big 4 city leaders but larger than third-tier firms; and (3) third-tier accounting firms have the lowest fees.
The Association between Partnership Financial Integration and Risky Audit Client Portfolios
Authors: Hay David C. , Baskerville Rachel F. , Qiu Travis Hui
Published: December 2007

This study examines whether profit-sharing arrangements within accounting firms are associated with the riskiness of their client portfolios. Our results use unique data about the profit-sharing arrangements of the Big 8 firms during the period 1985 to 1994. We investigate whether there is a correlation between profit-sharing and risky clients. Firms consist of the financially integrated firms, i.e., those that share their profits across a large pool of partners across the country and the financially independent firms that share their profits in a small pool on a local office basis. The large-pool firms provide more incentive for partners to cooperate to audit high-risk clients than the small-pool firms. Our results show that the large-pool firms are associated with riskier client portfolios; this is indicated by a higher proportion of fees from clients that later suffer from bankruptcies. In contrast, a smaller proportion of the clients of the small-pool firms go bankrupt. Tests using financial distress as alternative measures of client risk confirm this result.
Scales to Assess the Quality of Randomized Controlled Trials: A Systematic Review
Authors: Olivo Susan Armijo , Macedo Luciana Gazzi , Gadotti Inae Caroline , Fuentes Jorge , Stanton Tasha , Magee David J
Published: December 2007

Background and Purpose

The methodological quality of randomized controlled trials (RCTs) is commonly evaluated in order to assess the risk of biased estimates of treatment effects. The purpose of this systematic review was to identify scales used to evaluate the methodological quality of RCTs in health care research and summarize the content, construction, development, and psychometric properties of these scales.

Methods

Extensive electronic database searches, along with a manual search, were performed.

Results

One hundred five relevant studies were identified. They accounted for 21 scales and their modifications. The majority of scales had not been rigorously developed or tested for validity and reliability. The Jadad Scale presented the best validity and reliability evidence; however, its validity for physical therapy trials has not been supported.

Discussion and Conclusion

Many scales are used to evaluate the methodological quality of RCTs, but most of these scales have not been adequately developed and have not been adequately tested for validity and reliability. A valid and reliable scale for the assessment of the methodological quality of physical therapy trials needs to be developed.
Polyelectrolyte Blend Multilayers: A Versatile Route to Engineering Interfaces and Films
Authors: Quinn A. , Such G. K. , Quinn J. F. , Caruso F.
Published: December 2007

The ability to reliably engineer surfaces with nanoscale precision is a rapidly developing field of research with applications ranging from biosensing and biomedical materials to antifouling and corrosion protection. The layer‐by‐layer (LbL) approach is a widely utilized method for engineering surfaces, in part because of the large array of polymeric materials that can be integrated and the diverse range of functionality that these materials afford. Herein, we discuss the LbL deposition of multicomponent ‘blend' solutions to form polyelectrolyte blend multilayer films and coatings. This approach is a versatile platform for enhancing film stability, incorporating a wide range of functional materials, controlling film morphology and material properties, and increasing biological response, thereby expanding the range of potential applications.
Multiple Functionalization of Mesoporous Silica in One‐Pot: Direct Synthesis of Aluminum‐Containing Plugged SBA‐15 from Aqueous Nitrate Solutions
Authors: Wu Z. Y. , Wang H. J. , Zhuang T. T. , Sun L. B. , Wang Y. M. , Zhu J. H.
Published: December 2007

Aluminum‐containing plugged mesoporous silica has been successfully prepared in an aqueous solution that contains triblock copolymer templates, nitrates, and silica sources but without using mineral acid. The acidity of the solution can be finely tuned from pH 1.4 to 2.8 according to the amount of the introduced aluminum species which ranged from an Al/Si molar ratio of 0.25/1 to 4.0/1. The aluminum nitrate additive in the starting mixture, along with the weak acidity produced by the nitrates, contributes to the formation of plugged hexagonal structures and the introduction of different amounts of aluminum species into the mesostructure. Characterization by X‐ray diffraction, transmission electron microscopy, and N2 sorption measurements show that the Al‐containing plugged silicas possess well‐ordered hexagonal mesostructures with high surface areas (700–860 m2 g–1), large pore volume (0.77–1.05 cm3 g–1) and, more importantly, combined micropores and/or small mesopores in the cylindrical channels. Inductively coupled plasma–atomic emission spectrometry results show that 0.7–3.0 wt % aluminum can be introduced into the final samples. 27Al MAS NMR results display that about 43–60% aluminum species are incorporated into the skeleton of the Al‐containing silicas and the amount of the framework aluminum increases as the initial added nitrates rises. Scanning electron microscopy images reveal that the directly synthesized Al‐containing plugged silica has a similar morphology to that of traditional SBA‐15. Furthermore, the Al‐containing plugged samples have excellent performances in the adsorption and the catalytic decomposition of isopropyl alcohol and nitrosamine. Finally, the direct synthesis method is used to produce plugged mesoporous silicas that contain other metals such as chromium and copper, and the resultant samples also show good catalytic activities.
Graphene Physics in Graphite
Authors: Kopelevich Y. , Esquinazi P.
Published: December 2007

Single layers of carbon dubbed “graphene”, from which graphite is built, have attracted broad interest in the scientific community because of recent exciting experimental results. Graphene is interesting from a fundamental research perspective, as well as for potential technological applications. Here, we provide a brief overview of recent developments in this field, focusing especially on the electronic properties of graphite. Experimental evidence indicates that high‐quality graphite is a multi‐layer system with nearly decoupled 2D graphene planes. Based on experimental observations, we anticipate that thin graphite samples and not single layers will be the most promising candidates for graphene‐based electronics.
Inside Front Cover: Modulating Neuronal Responses by Controlled Integration of Acetylcholine‐like Functionalities in Biomimetic Polymers (Adv. Mater. 24/2007)
Authors: Gumera C. B. , Wang Y.
Published: December 2007

Primary neurons respond to acetylcholine functionalities in polymers in a dose‐dependent manner, report Christiane Gumera and Yadong Wang on p. 4404. The control of the interactions between a biomaterial and neurons may enable novel clinical treatments for neurological disorders. Here, the repeating unit of the polymer is shown on top of neurites extending from the dorsal root ganglia cultured on the polymer.