bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptação dos testes de lactato mínimo, potência crítica e limiar anaeróbio para avaliação da transição anaeróbia-anaeróbia em protocolo específico para o tênis de mesa
Authors: Morel Érika Alves , Zagatto Alessandro Moura
Published: February 2009

Os objetivos do estudo foram verificar a adaptação dos testes de lactato mínimo, freqüência crítica e limiar anaeróbio em protocolo específico para o tênis de mesa para avaliação da transição anaeróbia-anaeróbia; verificar a reprodutibilidade do teste de lactato mínimo; e verificar a associação desses procedimentos específicos com o limiar anaeróbio determinado em corrida em esteira rolante (LAn est). Para isso, foram estudados 11 mesatenistas com tempo mínimo de treinamento de dois anos. Foram aplicados os testes de: 1) lactato mínimo em duas ocasiões para análise da reprodutibilidade (LACmin1 e LACmin2); 2) teste de freqüência crítica (fcrit); 3) teste incremental para determinação do limiar anaeróbio através da concentração fixa de lactato de 3,5mM (LAn esp3,5) e regressão linear bissegmentada (LAnBI), todos em procedimentos específicos para o tênis de mesa; e 4) o limiar anaeróbio em corrida aplicado em esteira rolante (LAn est) determinado pela concentração fixa de lactato de 3,5mM. Nos procedimentos específicos foi utilizado um lançador de bolas mecânico como ergômetro e os participantes realizaram golpes apenas de forehand. Como procedimentos estatísticos foram utilizados os testes de Bland-Altman, correlação produto-momento e ANOVA one way, com nível de significância de 5%. As intensidades de LACmin (59,40 ± 4,06 e 61,56 ± 8,97 bolas.min-1) apresentaram boa concordância (teste de Bland-Altman) e foram significativamente correlacionadas (0,61). A fcrit, o LAn esp3,5 e o LAnBI foram correspondentes a 56,50 ± 6,84 bolas.min-1; 66,74 ± 5,03 bolas.min-1; e 62,67 ± 7,25 bolas.min-1, respectivamente. Foi verificada apenas diferença significativa entre as intensidades de LAn esp3,5 e de fcrit. Foram encontradas correlações significativas entre LACmin1 e LACmin2 (0,61), LACmin1 e fcrit (0,61), LACmin2 e fcrit (0,69), LAn esp3,5 e LAnBI (0,70), enquanto que o LAn est (9,11 ± 1,94km.h-1) foi apenas correlacionado com a intensidade de fcrit (0,73). Desse modo, pode-se concluir que o teste de LACmin específico é reprodutível e que esse procedimento, assim como o teste de fcrit, pode ser aplicado para avaliar a transição aeróbia-anaeróbia no tênis de mesa e que o LAn est deve ser utilizado com cautela na avaliação de mesatenistas.
Caminhada em ambiente aquático e terrestre: revisão de literatura sobre a comparação das respostas neuromusculares e cardiorrespiratórias
Authors: Silva Eduardo Marczwski da , Kruel Luiz Fernando Martins
Published: February 2009

O objetivo deste estudo foi realizar uma revisão de literatura sobre a comparação das respostas neuromusculares e cardiorrespiratórias durante a caminhada em meio aquático e em meio terrestre. As respostas foram apresentadas para a caminhada em piscina rasa e para a caminhada em piscina funda. Em relação à caminhada em piscina rasa, as respostas neuromusculares (sinal EMG) e cardiorrespiratórias (FC e VO2) são muito dependentes da velocidade do exercício. As respostas neuromusculares podem ser menores no meio aquático quando a velocidade da caminhada é menor nesse ambiente. Por outro lado, quando o exercício é realizado com velocidades similares, a atividade dos músculos propulsores pode ser superior durante a caminhada aquática. Da mesma forma, respostas cardiorrespiratórias maiores são registradas no exercício aquático quando velocidades similares de caminhada são utilizadas. Contudo, com velocidades menores, essas respostas são semelhantes ou menores que as encontradas em meio terrestre. No que diz respeito à caminhada em piscina funda, as respostas neuromusculares diferem daquelas encontradas durante a caminhada em meio terrestre devido à ausência das forças de reação com o solo. Essa característica possivelmente modifica os músculos envolvidos na produção de força propulsiva nesse exercício. Além do mais, durante a caminhada em piscina funda, as respostas cardiorrespiratórias parecem sempre mais baixas devido à grande redução no peso hidrostático e à menor atividade dos músculos posturais e pela utilização do cinturão flutuador nessa modalidade.
Behavioral flexibility of a group of bearded capuchin monkeys (Cebus libidinosus) in the National Park of Brasília (Brazil): consequences of cohabitation with visitors
Authors: Sabbatini G. , Stammati M. , Tavares MCH. , Visalberghi E.
Published: February 2009

Increasing urbanization and deforestation have enhanced the opportunities of contact between humans and monkeys and the impact of human activities on primate behavior is receiving growing attention. This study explores whether activity budgets and diet of a group of capuchin monkeys (Cebus libidinosus) inhabiting the area of the swimming pools of the National Park of Brasília is affected by the presence of visitors providing food to them. During one year, both in the dry and the wet seasons, we scored capuchins' behavior via scan sampling every ten minutes. Results showed that this group spent less time foraging for wild foods than other comparable groups living in similar habitats. Moreover, capuchins relied more on human food during the dry season, when pulpy fruits were less available, than in the wet season. Our findings confirm other studies on different monkey species that have shown that access to human food decreases the time spent foraging for wild food and the home range size. They also show that capuchins are able to modify their diet, to exploit alternative food sources, and to change their activity budget in response to the availability of new food opportunities and to seasonal food availability.
Interactions between benthic macroinvertebrates and fishes in a low order stream in Campos de Cima da Serra, RS, Brazil
Authors: Winckler-Sosinski LT. , Silveira TCL. , Schulz UH. , Schwarzbold A.
Published: February 2009

Benthic macroinvertebrates constitute the link between organic matter input in streams and fishes. However, the possibility of influence of predators on the invertebrates is still a controversial issue. The possibility of alteration of the benthic community by the modification in predation in a stream in the South of Brazil was studied by means of an exclusion experiment under semi-natural conditions. The exclusion showed an increase in the abundance of Plecoptera in the river where the rainbow trout was introduced, the larvae of Trichoptera also increased in abundance in the units of fish exclusion. This difference does not confirm the pressure applied by the trout on the benthic macro fauna due to differences in ichthyofauna and in the habitat of both rivers. Nevertheless, it points to the need for the development of studies concerning the trophic relations and the possible effects of this introduction in the aquatic biota.
Dynamics of the terrestrial amphibian assemblage in a flooded riparian forest fragment in a Neotropical region in the south of Brazil
Authors: Maltchik L. , Peixoto CD. , Stenert C. , Moreira LFB. , Machado IF.
Published: February 2009

The aim of this study was to analyze the richness, abundance and composition of the terrestrial amphibian assemblage in a flooded riparian forest fragment in a Neotropical region in the south of Brazil over a year (2002-2003). A total of 1,265 terrestrial amphibians were captured, representing 12 species and six families. Leiuperidae represented 41.7 and 56.3% of the total number of species and individuals captured, respectively. The amphibian richness and abundance were higher in the Spring-Summer than in the Autumn-Winter period, and these attributes did not change after the flood events. However, the floods homogeneously distributed the amphibian species over the fragment. Our study documented the terrestrial amphibian's use in a riparian forest fragment associated to a floodplain system in the south of Brazil, showing the importance of these habitats as possible dispersal corridors among nearby wetlands.
Spatial distribution of parasitism on Phyllocnistis citrella Stainton, 1856 (Lepidoptera: Gracillariidae) in citrus orchards
Authors: Jahnke SM. , Redaelli LR. , Diefenbach LMG. , Efrom CF.
Published: February 2009

Many species of microhymenopterous parasitoids have been registered on Phyllocnistis citrella, the citrus leafminer. The present study aimed to identify the spatial distribution pattern of the native and introduced parasitoids of P. citrella in two citrus orchards in Montenegro, RS. The new shoots from 24 randomly selected trees in each orchard were inspected at the bottom (0-1.5 m) and top (1.5-2.5 m) stratum and had their position relative to the quadrants (North, South, East and West) registered at every 15 days from July/2002 to June/2003. The leaves with pupae were collected and kept isolated until the emergence of parasitoids or of the leaf miner; so, the sampling was biased towards parasitoids that emerge in the host pupal phase. The horizontal spatial distribution was evaluated testing the fitness of data to the Poisson and negative binomial distributions. In Montenegrina, there was no significant difference in the number of parasitoids and in the mean number of pupae found in the top and bottom strata (χ2 = 0.66; df = 1; P > 0.05) (χ2 = 0.27; df =1; P > 0.05), respectively. In relation to the quadrants, the highest average numbers of the leafminer pupae and of parasitoids were registered at the East quadrant (χ2 = 11.81; df = 3; P < 0.05), (χ2 = 10.36; df = 3; P < 0.05). In the Murcott orchard, a higher number of parasitoids was found at the top stratum (63.5%) (χ2 = 7.24; df =1 P < 0.05), the same occurring with the average number of P. citrella pupae (62.9%) (χ2 = 6.66; df = 1; P < 0.05). The highest number of parasitoids and of miners was registered at the North quadrant (χ2 = 19. 29; df = 3; P < 0.05), (χ2 = 4.39; df = 3; P < 0.05). In both orchards, there was no difference between the numbers of shoots either relative to the strata as well as to the quadrants. As the number of shoots did not varied much relative to the quadrants, it is possible that the higher number of miners and parasitoids in the East and West quadrants would be influenced by the higher solar exposure of these quadrants. The data of the horizontal spatial distribution of the parasitism fit to the negative binomial distribution in all sampling occasions, indicating an aggregated pattern.
Taxonomic review of the genus Adelomelon (Gastropoda; Volutidae), based on type material
Authors: Wiggers F. , Veitenheimer-Mendes IL.
Published: February 2009

The genus Adelomelon Dall, 1906 comprises a group of South American marine gastropods. We present updated information on the genus Adelomelon, with emphasis on the status and location of type material, including that of junior synonyms. Scaphella arnheimi Rivers, 1891 and Voluta paradoxa Lahille, 1895 are removed from the synonymy of Adelomelon ancilla (Lightfoot, 1758) and Adelomelon barattinii Klappenbach and Ureta, 1966 is included. The subgenus Weaveria Clench and Turner, 1964 is placed in synonymy with Adelomelon s.s. A key to the species of Adelomelon is provided.
Brood size and its importance for nestling growth in the Biscutate Swift (Streptoprocne biscutata, Aves: Apodidae)
Authors: Pichorim M. , Monteiro-Filho ELA.
Published: February 2009

Many Apodidae, including Streptoprocne biscutata (Sclater, 1866), drop eggs from their nests during incubation. This is interpreted as nest site competition or accident. We provide evidence that egg ejection is deliberate and that this behaviour controls the brood size. Brood sizes were manipulated and nestling growth was measured to test the hypothesis that pairs can regulate brood size during incubation based on current ability to rear nestlings. Natural (control) broods with one, two and three nestlings, and manipulated (experimental) broods reduced to one and increased to two and three young were monitored. Growth rates were measured based on weight, and wing, tail and tarsus lengths of natural and manipulated broods. We compared the slopes of each measure's regression lines of the nestlings of each brood size by t-test. Nestling growth of control nests was similar and relatively little associated with brood size. In broods reduced to one nestling, weight, wing and tail had greater growth rates, and in broods increased to three nestlings growth rates were lower. Weight was most, and tarsus length least influenced by brood size. In general, nestling growth of manipulated nests was inversely proportional to brood size. The results suggest that pairs with larger clutches are in better physical conditions than others. Thus, in experimental broods, pairs are over or under-loaded because feeding activities increase or decrease and these changes affect the growth rate of the nestlings. The present study suggests that egg ejection can control brood size. This behaviour is probably stimulated by physical changes in the adult birds during incubation.
Shell occupation by the endemic western Atlantic hermit crab Isocheles sawayai (Diogenidae) from Caraguatatuba, Brazil
Authors: Fantucci MZ. , Biagi R. , Mantelatto FL.
Published: February 2009

The aim of this study was to characterize the pattern of shell occupation by the hermit crab Isocheles sawayai Forest and Saint-Laurent, 1968, from the Caraguatatuba region. The percentage of shell types that were occupied and the morphometric relationships between hermit crabs and occupied shells were analyzed from systematized collections that were conducted monthly from July 2001 to June 2003. A total of 373 individuals were captured (297 males, 41 non-ovigerous females, 25 ovigerous females and 10 intersexes), occupying 17 species of gastropod shells. Stramonita haemastoma (Linnaeus, 1767) (49.87%) was the significantly most occupied species (χ2 = 89.30; P < 0.05) followed, with no significant difference, by Phalium granulatum (Born, 1778) (11.53%), Polinices hepaticus (Roding, 1798) (8.31%) and Cymatium parthenopeum (von Salis, 1793) (6.97%). All the morphometric relationships between hermit crabs and occupied shells showed high (r > 0.68) and significant (P < 0.05) correlation values, which is an important indication that in this I. sawayai population the animals occupied adequate shells. The high number of occupied shell species and relative plasticity indicated that, for the studied population, occupation is influenced by the shell availability.
Influence of food restriction on the reproduction and larval performance of matrinxã, Brycon amazonicus (Spix and Agassiz, 1829)
Authors: Camargo ACS. , Urbinati EC.
Published: February 2009

This work evaluated the effect of food restriction and refeeding of matrinxã females, Brycon amazonicus, on their reproductive performance and on the growth and survival of the progeny. Broodstocks were distributed in 8 earthen tanks (15 fish/tank) and fish from 4 tanks were fed daily (G1) while fish from the other 4 tanks were fed for 3 days and not fed for 2 days (G2) during 6 months prior to artificial spawning. Among the induced females, 57% in G1 group and 45% in G2 group spawned and the mean egg weights were 208.1 g (G1) and 131.6 g (G2). Oocytes of G2 fish were smaller (1.017 ± 0.003 mm) than oocytes of G1 fish (1.048 ± 0.002 mm). Fertilization (71.91 ± 12.6% and 61.18 ± 13.7%) and hatching (61.28 ± 33.9% and 67.50 ± 23.4%) rates did not differ between G1 and G2 fish. Larvae were collected at hatching and at 24, 48 and 72 hours of incubation and fixed for growth measurement. After incubation, fry were transferred to aquaria and sampled 1, 5, 9 and 15 days later. G1 and G2 larvae had similar weight (1.51 ± 0.15 and 1.46 ± 0.07 mg) but the G2 length was significantly higher (6.26 ± 0.13 and 6.74 ± 0.14 mm). By the ninth day of rearing, G2 fry had higher weight (13.6 ± 0.26 and 18.9 ± 0.07 mg) and length (11.8 ± 0.09 and 14.5 ± 0.04 mm) but by the fifteenth day, G1 fry had higher weight (90.2 ± 1.19 and 68.6 ± 0.77 mg) and length (18.8 ± 0.16 and 18.5 ± 0.04 mm) than G2 fry. By the ninth day of rearing, when fry are recommended to be transferred to outdoor tanks, G2 fry were larger and after 15 days, fry produced by restricted-fed females showed higher survival. The survival rate of G2 progeny by the fifteenth day was significantly higher (24.7 ± 2.07%) than that of G1 progeny (19.2 ± 1.91%). The ration restriction (35% reduction) imposed on matrinxã broodstock during 6 months prior to spawning reduced the number of spawned females and the egg amount, but it did not affect fertilization and hatching rates. Otherwise restricted-female larvae were larger and presented higher survival.
Comments about some species abundance patterns: classic, neutral, and niche partitioning models
Authors: Ferreira FC. , Petrere-Jr. M.
Published: February 2009

The literature on species abundance models is extensive and a great deal of new and important contributions have been published in the last three decades. Broadly speaking, one can recognize five families of species abundance models: i) purely statistical or classic models (Broken-stick, Log-normal, Logarithmic and Geometric series); ii) branching process (Zipf-Mandelbrot and Fractal branching models); iii) population dynamics (Neutral models included); iv) spatial distribution of individuals (Multifractal and HEAP models) and v) niche partitioning (Sugihara's breakage and Tokeshi models). Among these the neutral, the classic and the niche partitioning models have been the most applied to natural communities, the former having been more extensively discussed than the others in the last years. The objective of this paper is to comment some aspects of the classic, neutral and niche partitioning models in a way that the proposed distributions may contribute to the analysis of the empirical patterns of species abundance. In spite of the variety of models, the distributions in general vary between the log-normal and the logarithmic series. From these models the Power-Fraction, together with independent niche dimensions measures, are amenable to experimental tests and may offer answers on which resources are important in the structuring of biological communities.
The inverted trophic cascade in tropical plankton communities: impacts of exotic fish in the Middle Rio Doce lake district, Minas Gerais, Brazil
Authors: Pinto-Coelho RM. , Bezerra-Neto JF. , Miranda F. , Mota TG. , Resck R. , Santos AM. , Maia-Barbosa PM. , Mello NAST. , Marques MM. , Campos MO. , Barbosa FAR.
Published: February 2009

The present study deals with the ecological impacts of the introduction of two alien species of piscivorous fish in several lakes of the Middle Rio Doce lake district in Minas Gerais, Brazil. It was demonstrated that these effects were not restricted only to the fish community. The introduction of the predatory red piranha Pygocentrus nattereri and the tucunaré Cichla cf. ocellaris caused not only a sharp decrease in the number of native fish species, but also major shifts in other trophic levels. Just after the fish were introduced, most lakes began to show conspicuous changes in phytoplankton species composition, in which Cyanophyceae gradually came to dominate. The zooplankton community lost several species, and in some cases, such as Lake Carioca, all the cladoceran species disappeared. On the other hand, invertebrate predators, represented by the dipteran Chaoboridae, boomed in the lake, with higher densities of exotic species, probably as a result of the "ecological release" by reduction of the original fish fauna. There was a general trend of species loss in different trophic levels. All these changes are apparently associated with decreases in water quality. The present situation in these lakes demands new approaches to the management and conservation of these ecosystems.
Zooplankton in littoral waters of a tropical lake: a revisited biodiversity
Authors: Maia-Barbosa PM. , Peixoto RS. , Guimarães AS.
Published: February 2009

The present study was carried out in Lake Dom Helvécio, in the state of Minas Gerais, with two main objectives: to demonstrate the contribution of the littoral zone, in order to better characterize zooplankton fauna; and to assess the distribution of zooplankton species in different habitats, i.e., the littoral zone with and without aquatic vegetation. The samples were collected in February and July 2006, throughout the littoral zone of the lake, in areas with and without aquatic vegetation. We identified a total of 188 species, of which 130 are new records for Lake Dom Helvécio. One hundred and eighty-four species were identified in the littoral zone with aquatic vegetation, and 117 in the zone with no vegetation. The higher zooplankton richness in areas of the littoral zone with aquatic vegetation can be related to the greater environmental heterogeneity. Compared to previous studies on the littoral zones of lakes along the middle River Doce, the present study expended greater sampling effort, and identified many more species. In relation to biological conservation, this study demonstrated the importance of the littoral zone for better characterization and conservation of the zooplankton fauna, especially when it is colonized by aquatic vegetation. Underestimating the richness of species may provide inaccurate data on the biota, as well as on the ecological conditions in an environment.
Reservoirs and human well being: new challenges for evaluating impacts and benefits in the neotropics
Authors: Tundisi JG. , Matsumura-Tundisi T. , Tundisi JEM.
Published: February 2009

As in many other continents, neotropical ecosystems are impacted by the construction of reservoirs. These artificial ecosystems change considerably the natural terrestrial and aquatic ecosystems and their biodiversity. The multiple uses of reservoirs promote benefits for the human beings in terms of economic development, income, jobs and employment. Services of reservoirs are important assets for the regional ecosystem. Evaluation of ecosystem services produced by artificial reservoirs, are new challenges to the understanding of the cost/benefit relationships of reservoir construction in the neotropics. Regulating and other services promoted by reservoirs lead to new trends for "green technology" and the implementation of ecohydrological and ecotechnological developments. This approach can be utilized with better success as a substitute for the usual impact/benefit evaluation of the reservoirs. Better and diversified services can be achieved with "green technology" applied to the construction.
Patristic evolutionary rates suggest a punctuated pattern in forelimb evolution before and after the origin of birds
Authors: Dececchi T. Alex , Larsson Hans C. E.
Published: February 2009

The evolution of powered flight has traditionally been associated with the origin of birds, the most successful clade of modern tetrapods, as exemplified by the nearly 10,000 species alive today. Flight requires a suite of morphological changes to skeletal anatomy to create a light yet resistant framework for an airfoil and advanced nervous motor control. Given the level of morphological integration necessary to create a suitable aerofoil, the origin of flight may be intuitively assumed to be coupled with high evolutionary rates of wing-related morphologies. Here we show that the origin of birds is associated with little or no evolutionary change to the skeletal anatomy of the forelimb, and thusArchaeopteryxis unlikely to be the “Rosetta Stone” for the origin of flight it was once believed to be. Using comparative statistics and time-series analyses on a data set constructed from all known forelimb skeletal anatomy of non-avian theropod dinosaurs and a diverse assemblage of early birds, we demonstrate three focused peaks of rapid forelimb evolution at Tetanurae, Eumaniraptora, and Ornithothoraces. The peaks are not associated with missing data and remain stable under multiple perturbations to the phylogenetic arrangements. Different regions of the forelimbs are demonstrated to have undergone asynchronous periods of evolutionary peaks and stasis. Our results evince a more complicated stepwise mode of forelimb evolution before and after the origin of Aves than previously supposed.
EMDR With Children and Adolescents After Single-Incident Trauma An Intervention Study
Authors: Hensel Thomas
Published: February 2009

This study used a naturalistic design to investigate the effectiveness of eye movement desensitization and reprocessing (EMDR) with children and adolescents who were exposed to single-incident trauma. Participants were 36 children and adolescents ranging in age from 1 year 9 months to 18 years 1 month who were referred consecutively to the author’s private practice. Assessments were conducted at intake, post-waitlist/pretreatment, and at follow up. EMDR treatment resulted in significant improvement (Cohen’s d = 1.87). Follow-ups after 6 months revealed stable, further slight improvement. It was shown that children younger than 4 years of age can be treated using EMDR and that the group of preschool children had the same benefit from the treatment as the school-age children.
Present and Accounted For: Sensory Stimulation and Parietal Neuroplasticity
Authors: Pearson Heather J.
Published: February 2009

There are commonalities between neurologic syndromes arising from lesions of the parietal cortex and psychiatric syndromes secondary to psychological trauma. Additionally some posttraumatic syndromes may reflect functional disruption of parietal areas. Directional or bilateral alternating peripheral sensory stimulation appear to assist in the amelioration of a wide range of clinical conditions, including the neglect syndrome and Posttraumatic Stress Disorder. It is posited that the stimulation may exert its effect through activation of parietal higher-order functions. The activation may result in an integration of sensory information and an updating of the current representation of person and space, which incorporates an awareness of current body reality, sense of self, and world view. It is hypothesized that the EMDR procedure is ideally constructed to facilitate parietal activation through multimodal sensory stimulation, attention and episodic memory retrieval and focus on internal and external body, space, and self. Further investigations and an integration of data between disciplines are suggested, in order to expand our range of effective treatments.
Toxicity of manufactured zinc oxide nanoparticles in the nematodeCaenorhabditis elegans
Authors: Ma Hongbo , Bertsch Paul M. , Glenn Travis C. , Kabengi Nadine J. , Williams Phillip L.
Published: February 2009

Information describing the possible impacts of manufactured nanoparticles on human health and ecological receptors is limited. The objective of the present study was to evaluate the potential toxicological effects of manufactured zinc oxide nanoparticles (ZnO-NPs; 1.5 nm) compared to aqueous zinc chloride (ZnCl2) in the free-living nematode Caenorhabditis elegans. Toxicity of both types of Zn was investigated using the ecologically relevant endpoints of lethality, behavior, reproduction, and transgene expression in a mtl-2::GFP (gene encoding green fluorescence protein fused onto the metallothionein-2 gene promoter) transgenic strain of C. elegans. Zinc oxide nanoparticles showed no significant difference from ZnCl2 regarding either lethality or reproduction in C. elegans, as indicated by their median lethal concentrations (LC50s; p = 0.29, n = 3) and median effective concentrations (EC50s; Z = 0.835, p = 0.797). Also, no significant difference was found in EC50s for behavioral change between ZnO-NPs (635 mg Zn/L; 95% confidence interval [CI], 477–844 mg Zn/L) and ZnCl2 (546 mg Zn/L; 95% CI, 447–666 mg Zn/L) (Z = 0.907, p = 0.834). Zinc oxide nanoparticles induced transgene expression in the mtl-2::GFP transgenic C. elegans in a manner similar to that of ZnCl2, suggesting that intracellular biotransformation of the nanoparticles might have occurred or the nanoparticles have dissolved to Zn2+ to enact toxicity. These findings demonstrate that manufactured ZnO-NPs have toxicity to the nematode C. elegans similar to that of aqueous ZnCl2.
When Does Teacher Licensure Make Sense?
Authors: Arias J. J. , Scafidi Benjamin
Published: February 2009

Teacher licensure is a regime where schools are forbidden from hiring teachers who have not completed a program of study in a teacher education program and/or other preparation requirements. This paper specifies a theoretical model of a school hiring teachers who are either traditionalcompleted a program of study in a teacher education program or alternativeentered teaching through an alternative path. We combine the implications of the theoretical model with the empirical literature on teacher labor markets to reach conclusions about how labor market policies would impact teacher quality. Perhaps the most important conclusion is that it is very likely that a regime of teacher licensure would lower teacher quality and student achievement. The key reason why licensure would lower teacher quality is that licensure fails to make the important distinction between marginal and average quality in hiring decisions.
Mediastinal Lipoblastomatosis: Report of a Case with Complex Karyotype and Review of the Literature
Authors: Amra Nasir K. , Amr Samir S.
Published: February 2009

Lipoblastoma or lipoblastomatosis is an uncommon fatty tumor seen in children up to the age of 5 years, with very rare exceptions above that age. It usually occurs in the extremities, but it can arise in other anatomical sites, including the head and neck area, trunk, mediastinum, mesentry, and retroperitoneum. We report a 9-month-old boy with mediastinal lipoblastomatosis showing unusually complex chromosomal aberrations. Five years following surgical excision that was incomplete as a result of the tumor's proximity to major blood vessels, the patient developed a recurrence of the tumor in the mediastinum with extension to the neck and spinal dura. We present a review of the literature related to mediastinal lipoblastoma and lipoblastomatosis and the chromosomal abnormalities of these tumors.
Gauss’ law of error revisited in the framework of Sharma-Taneja-Mittal information measure
Authors: Scarfone Antonio , Suyari Hiroki , Wada Tatsuaki
Published: February 2009

We reformulate the Gauss’ law of error in presence of correlations which are taken into account by means of a deformed product arising in the framework of the Sharma-Taneja-Mittal measure. Having reviewed the main proprieties of the generalized product and its related algebra, we derive, according to the Maximum Likelihood Principle, a family of error distributions with an asymptotic power-law behavior.
DFT study on electronic structures and optical absorption properties of C, S cation- doped SrTiO3
Authors: Liu Jiawen , Wang Lu , Liu Jihong , Wang Tianchi , Qu Weili , Li Zhonghua
Published: February 2009

The effects of C cation and S cation doping on the electronic structures and optical properties of SrTiO3 are investigated by density function theory (DFT) calculations. The calculated results reveal that the top of the valence band is predominately made up of the O 2p states for the pure SrTiO3. When SrTiO3 was doped with C cation and S cation, the top of the valence bands consists mainly of O 2p+C 2s hybrid orbitals and O 2p+S 3s hybrid orbitals, respectively. The band gap of SrTiO3 is narrowed by the doping with C cation and S cation, especially for the C and S-codoped SrTiO3. Moreover, the red shifts of the absorption edge are found by the calculated optical properties, which is consistent with reported experiment results. It is the explanation for their visible light respondency by the presence of C 2s and S 3s states on the upper edge of the valence band. All of these results can explain the good photocatalytic properties of C, S cation-codoped SrTiO3 under visible light irradiation.
One-Year Follow-Up Outcomes of Spanish and English Interventions for English Language Learners at Risk for Reading Problems
Authors: Cirino Paul T. , Vaughn Sharon , Linan-Thompson Sylvia , Cardenas-Hagan Elsa , Fletcher Jack M. , Francis David J.
Published: February 2009

The authors report 1-year follow-up data from 215 English language learners with reading difficulties who received a supplemental first grade reading intervention in the language of their core reading instruction. The researchers provided no intervention or boosters in second grade. The Spanish study revealed significant differences favoring treatment students on Spanish measures of decoding, spelling, fluency, and comprehension (median d = 0.53). Similar results were evidenced in the English study, with significant differences favoring treatment students on English measures of oral language, decoding, spelling, fluency, and comprehension (median d = 0.40). Few direct transfer effects were noted for either language. The first grade intervention was associated with stronger skills in a variety of literacy-related domains 1 year after its termination.
Probabilistic Distributed Algorithms for Energy Efficient Routing and Tracking in Wireless Sensor Networks
Authors: Nikoletseas Sotiris , Spirakis Paul G.
Published: February 2009

In this work we focus on the energy efficiency challenge in wireless sensor networks, from both an on-line perspective (related to routing), as well as a network design perspective (related to tracking). We investigate a few representative, important aspects of energy efficiency: a) the robust and fast data propagation b) the problem of balancing the energy dissipation among all sensors in the network and c) the problem of efficiently tracking moving entities in sensor networks. Our work here is a methodological survey of selected results that have already appeared in the related literature. In particular, we investigate important issues of energy optimization, like minimizing the total energy dissipation, minimizing the number of transmissions as well as balancing the energy load to prolong the system’s lifetime. We review characteristic protocols and techniques in the recent literature, including probabilistic forwarding and local optimization methods. We study the problem of localizing and tracking multiple moving targets from a network design perspective i.e. towards estimating the least possible number of sensors, their positions and operation characteristics needed to efficiently perform the tracking task. To avoid an expensive massive deployment, we try to take advantage of possible coverage overlaps over space and time, by introducing a novel combinatorial model that captures such overlaps. Under this model, we abstract the tracking network design problem by a covering combinatorial problem and then design and analyze an efficient approximate method for sensor placement and operation.
Quantum Dots for Live Cell and In Vivo Imaging
Authors: Walling Maureen A. , Novak Jennifer A. , Shepard Jason R. E.
Published: February 2009

In the past few decades, technology has made immeasurable strides to enable visualization, identification, and quantitation in biological systems. Many of these technological advancements are occurring on the nanometer scale, where multiple scientific disciplines are combining to create new materials with enhanced properties. The integration of inorganic synthetic methods with a size reduction to the nano-scale has lead to the creation of a new class of optical reporters, called quantum dots. These semiconductor quantum dot nanocrystals have emerged as an alternative to organic dyes and fluorescent proteins, and are brighter and more stable against photobleaching than standard fluorescent indicators. Quantum dots have tunable optical properties that have proved useful in a wide range of applications from multiplexed analysis such as DNA detection and cell sorting and tracking, to most recently demonstrating promise for in vivo imaging and diagnostics. This review provides an in-depth discussion of past, present, and future trends in quantum dot use with an emphasis on in vivo imaging and its related applications.
Morphological variation of intervessel pit membranes and implications to xylem function in angiosperms
Authors: Jansen Steven , Choat Brendan , Pletsers Annelies
Published: February 2009

Pit membranes between xylem vessels have been suggested to have functional adaptive traits because of their influence on hydraulic resistance and vulnerability to embolism in plants. Observations of intervessel pit membranes in 26 hardwood species using electron microscopy showed significant variation in their structure, with a more than 25‐fold difference in thickness (70–1892 nm) and observed maximum pore diameter (10–225 nm). In some SEM images, pit membrane porosity was affected by sample preparation, although pores were resolvable in intact pit membranes of many species. A significant relationship (r2 = 0.7, P = 0.002) was found between pit membrane thickness and maximum pore diameter, indicating that the thinner membranes are usually more porous. In a subset of nine species, maximum pore diameter determined from SEM was correlated with pore diameter calculated from air‐seeding thresholds (r2 = 0.8, P < 0.001). Our data suggest that SEM images of intact pit membranes underestimate the porosity of pit membranes in situ. Pit membrane porosity based on SEM offers a relative estimate of air‐seeding thresholds, but absolute pore diameters must be treated with caution. The implications of variation in pit membrane thickness and porosity to plant function are discussed.
Predicting the allometry of leaf surface area and dry mass
Authors: Niklas Karl J. , Cobb Edward D. , Spatz Hanns‐Christof
Published: February 2009

The manner in which increases in leaf surface areaSscale with respect to increases in leaf dry massMtwithin and across species has important implications to understanding the ability of plants to harvest sunlight, grow, and ultimately reproduce. Thus far, no mechanistic explanation has been advanced to explain why prior work shows that the scaling exponent governing theStoMtrelationship is generally significantly less than one (i.e.,S∝Mtα < 1.0) such that increases inMtyield diminishing returns with respect to increases inSacross most species. Here, we show analytically why this phenomenon occurs and present equations that predict trends observed in the numerical values of scaling exponents for theSvs.Mtrelationships observed across dicot tree species and two aquatic vascular plant species.
Three extant genera of freshwater thalassiosiroid diatoms from Middle Eocene sediments in northern Canada
Authors: Wolfe Alexander P. , Siver Peter A.
Published: February 2009

The evolutionary history of diatoms is only constrained partially by the fossil record. The timing of several key events, such as initial colonization of freshwater habitats by marine taxa, remains poorly resolved. Numerous specimens of the genera Cyclotella, Discostella, and Puncticulata (Ochrophyta: Thalassiosirales) have been recovered in Middle Eocene lacustrine sediments from the Giraffe Pipe locality in the Northwest Territories, Canada. These diatoms extend the fossil record of the family Stephanodiscaceae to at least 40 million years before present (Ma) and thus provide a new evolutionary milepost for the thalassiosiroid diatoms, an important clade of centric diatoms with global representation in both marine and freshwater environments. The quality of the fossil material enables detailed investigations of areolae, fultoportulae, and rimoportulae, revealing direct morphological affinities with a number of extant taxa. These observations extend the antiquity of several characters of phylogenetic importance within the thalassiosiroid diatoms, including the fultoportula, and imply that the entire lineage is considerably older than prior constraints from the fossil record, as suggested independently by several recent molecular phylogenies.
Zeolite catalyzed solvent-free one-pot synthesis of dihydropyrimidin-2(1H)-ones – A practical synthesis of monastrol
Authors: Kulkarni Mukund G , Chavhan Sanjay W , Shinde Mahadev P , Gaikwad Dnyaneshwar D , Borhade Ajit S , Dhondge Attrimuni P , Shaikh Yunnus B , Ningdale Vijay B , Desai Mayur P , Birhade Deekshaputra R
Published: February 2009

A zeolite-catalyzed, simple, one-pot, solvent-free, cost effective, and environmentally benign process for the synthesis of dihydropyrimidones is described. This reaction is scaleable to multigram scale and the catalyst is recyclable. This methodology has resulted in an efficient synthesis of monastrol, a potent inhibitor of kinesin Eg5.
Memoria del exilio y exilio de la memoria
Authors: Sánchez Cuervo Antolín
Published: February 2009

Historia y memoria no son términos equivalentes, menos aún cuando apuntan hacia un pasado atravesado por la exclusión y la injusticia. Si lo primero tiende a reducir ese pasado en términos de objetividad científica, lo segundo pone el acento en su actualidad crítica. Tal es la tensión que suscita el rescate de un episodio como el exilio español de 1939. Algunas reflexiones de tres pensadores emblemáticos del mismo como Eugenio Ímaz, María Zambrano y Adolfo Sánchez Vázquez resultan iluminadoras en este sentido. Escritas en momentos y contextos tan significativos como la posguerra, el llamado segundo franquismo y el horizonte de la España democrática, sugieren claves hermenéuticas relevantes a la hora de plantear una memoria del exilio.
Los frutos perdidos: los intelectuales de la Residencia de Estudiantes en el exilio
Authors: Ribagorda Álvaro
Published: February 2009

El exilio español de 1936 supuso uno de los episodios más traumáticos de la historia española. Miles de intelectuales se vieron obligados a abandonar España, donde fueron perseguidos, condenados y difamados por la dictadura de Franco. La Residencia de Estudiantes había sido la institución más representativa de la modernización de España antes de la Guerra Civil, y muchos de los intelectuales españoles más importantes que tuvieron que exiliarse estaban estrechamente ligados a la Residencia. Estudiando las biografías de algunos de ellos podemos intentar comprender la aportación del exilio español al desarrollo cultural de otros países, y la extraordinaria pérdida que su marcha supuso para España.
La actividad política de las mujeres republicanas en México (1940-1960)
Authors: Domínguez Prats Pilar
Published: February 2009

Durante el exilio en México, una parte significativa de la minoría femenina activa en política en el período republicano se dedicó a la reconstrucción de una de las organizaciones de mujeres que habían funcionado en España durante la guerra, la “Agrupación de Mujeres Antifascistas”. Así se creó en los años cuarenta la Unión de Mujeres Españolas, dedicada en especial a la solidaridad material con las mujeres y los hombres presos dentro de las cárceles franquistas. Su actividad política desarrollada a partir de un discurso “femenino pero no feminista” plantea la fluida relación existente entre el espacio privado del hogar y lo público, en relación con las actividades antifranquistas emprendidas por estas mujeres desde los años cuarenta hasta los sesenta.
Itinerarios cubanos del exilio gallego
Authors: Cagiao Vila Pilar , Pérez Rey Nancy
Published: February 2009

Para los gallegos que sufrieron el exilio de la Guerra Civil, Cuba representó una posibilidad real mediatizada en buena medida por las relaciones mantenidas anteriormente con Galicia en virtud de las redes sociales establecidas por la emigración. Exiliados de la más diversa adscripción política y profesional llegaron al país, de modo temporal o definitivo, constituyendo un eslabón más en las relaciones históricas mantenidas entre ambos pueblos.
Nos asedian con el silencio. Reflexiones y actuaciones de José Cuatrecasas Arumí (1903-1996) en torno a la República española desde su exilio norteamericano
Authors: González Bueno Antonio
Published: February 2009

El exilio español causado por la Guerra Civil no acabó con el transterramiento de los republicanos españoles en los territorios de acogida; su huella perduró hasta el final del franquismo. La correspondencia cursada entre José Cuatrecasas con José Asensio y Fernando Valera es buena prueba de los intentos de un pequeño grupo de españoles exilados en los Estados Unidos de Norteamérica por ser útiles al Gobierno de la República en los duros años de las décadas de 1950 y 1960, cuando las relaciones entre Eisenhower y Franco cobran especial protagonismo: la negociación de las bases, la ayuda norteamericana, la integración de España en la ONU, la pérdida del Protectorado marroquí, las huelgas de estudiantes y tantos otros acontecimientos tienen una particular lectura desde la óptica de quienes siempre vislumbraron la posibilidad de retornar a una España democrática.
Una princesa medieval y otras cuestiones de biología
Authors: Cervantes Emilio
Published: February 2009

Partiendo de la historia de la princesa Cristina, que vino hacia 1250 de Noruega a España para casarse con el rey Alfonso X se plantea una visión original del conocimiento en general y, en particular, de aspectos de la biología que tienen mucho en común con la historia. Los primeros capítulos contienen reflexiones acerca del tiempo y la importancia que tiene, en biología, el modo de verlo e interpretarlo. Siguen unos capítulos acerca del conocimiento, qué es y cómo es adquirido. A continuación capítulos sobre diversos aspectos de la biología: su historia, la importancia relativa de la observación y de la experimentación, sus relaciones con la lingüistica, la psicología y la pedagogía. El capítulo final, titulado: «Biología y Filosofía. Perspectivas» se ha escrito con la intención de buscar un acercamiento entre ambas disciplinas que es hoy en día necesario.
Ligand‐Accelerated Asymmetric [1,2]‐Stevens Rearrangment of Sulfur Ylides via Decomposition of Diazomalonates Catalyzed by Chiral Bisoxazoline/Copper Complex
Authors: Qu Jian‐Ping , Xu Zheng‐Hu , Zhou Jian , Cao Chun‐Li , Sun Xiu‐Li , Dai Li‐Xin , Tang Yong
Published: February 2009

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The first example of catalytic asymmetric [1,2]‐Stevens rearrangement reaction of 1,3‐oxathiolanes with diazomalonates has been developed and up to 90% ee is achieved by the bisoxazoline 4e/copper(II) triflate [Cu(OTf)2] complex.
Atom transfer radical polymerization and copolymerization of vinyl acetate catalyzed by copper halide/terpyridine
Authors: Tang Huadong , Radosz Maciej , Shen Youqing
Published: February 2009

Copper‐mediated atom transfer radical polymerization (ATRP) is versatile for living polymerizations of a wide range of monomers, but ATRP of vinyl acetate (VAc) remains challenging due to the low homolytic cleavage activity of the carbon‐halide bond of the dormant poly(vinyl acetate) (PVAc) chains and the high reactivity of growing PVAc radicals. Therefore, all the reported highly active copper‐based catalysts are inactive in ATRP of VAc. Herein, we report the first copper‐catalyst mediated ATRP of VAc using CuBr/2,2′:6′,2″‐terpyridine (tPy) or CuCl/tPy as catalysts. The polymerization was a first order reaction with respect to the monomer concentration. The molecular weights of the resulting PVAc linearly increased with the VAc conversion. The living character was further proven by self‐chain extension of PVAc. Using polystyrene (PS) as a macroinitiator, a well‐defined diblock copolymer PS‐b‐PVAc was prepared. Hydrolysis of the PS‐b‐PVAc produced a PS‐b‐poly(vinyl alcohol) amphiphilic diblock copolymer. © 2009 American Institute of Chemical Engineers AIChE J, 2009