2,264 research outputs found
Fisher perceptions of Belize's Managed Access program reveal overall support but need for improved enforcement
A major challenge facing global fisheries is gaining support for sustainable management, which is vital for ensuring the longevity of coastal resources for livelihood and ecosystem benefits. Territorial User Rights for Fishing (TURFs) have emerged as a possible solution to overfishing by requiring fishers to report their catch, color-code their vessels, and fish in designated areas. Belize was the first country in the Caribbean to implement TURFs - in a program called "Managed Access" - with two pilot sites opening in 2011 and seven sites added in 2016. This study evaluates the knowledge, attitudes and perceptions of fishers in the Managed Access program, comparing responses between 2014 and 2019. We collaborated with the Belize Fisheries Department and two local conservation organizations to administer surveys to 362 fishers in 2014 and 123 fishers in 2019, from ten communities in southern Belize. Overall, fishers in both years understood the requirements for acquiring and renewing their licenses, but in 2019, significantly more fishers understood the logbook reporting requirement and the benefits of having tenure rights than those in 2014. 69% of respondents from 2019 support the program in the long run, but 62% report observing illegal fishing behavior. These data suggest a need to educate fishers about the benefits of accurate catch reporting, improve enforcement, and develop fisher empowerment programs, while also guiding management decisions on a national scale. Although the Managed Access program in Belize is fairly new, the lessons learned can be applied to other small-scale fisheries contexts
Excess body weight in children may increase the length of hospital stay
OBJECTIVES: To investigate the prevalence of excess body weight in the pediatric ward of University Hospital and to test both the association between initial nutritional diagnosis and the length of stay and the in-hospital variation in nutritional status. METHODS: Retrospective cohort study based on information entered in clinical records from University Hospital. The data were collected from a convenience sample of 91 cases among children aged one to 10 years admitted to the hospital in 2009. The data that characterize the sample are presented in a descriptive manner. Additionally, we performed a multivariate linear regression analysis adjusted for age and gender. RESULTS: Nutritional classification at baseline showed that 87.8% of the children had a normal weight and that 8.9% had excess weight. The linear regression models showed that the average weight loss z-score of the children with excess weight compared with the group with normal weight was −0.48 (p = 0.018) and that their length of stay was 2.37 days longer on average compared with that of the normal-weight group (p = 0.047). CONCLUSIONS: The length of stay and loss of weight at the hospital may be greater among children with excess weight than among children with normal weight
The Luminous Starburst Ring in NGC 7771: Sequential Star Formation?
Only two of the twenty highly luminous starburst galaxies analyzed by Smith
et al. exhibit circumnuclear rings of star formation. These galaxies provide a
link between 10^11 L_sun systems and classical, less-luminous ringed systems.
We report the discovery of a near-infrared counterpart to the nuclear ring of
radio emission in NGC 7771. A displacement between the ~10 radio bright clumps
and the ~10 near-infrared bright clumps indicates the presence of multiple
generations of star formation. The estimated thermal emission from each radio
source is equivalent to that of ~35000 O6 stars. Each near-infrared bright knot
contains ~5000 red supergiants, on average. The stellar mass of each knot is
estimated to be ~10^7 M_sun. The implied time-averaged star formation rate is
\~40 M_sun per yr. Several similarities are found between the properties of
this system and other ringed and non-ringed starbursts. Morphological
differences between NGC 7771 and the starburst + Seyfert 1 galaxy NGC 7469
suggest that NGC 7771 may not be old enough to fuel an AGN, or may not be
capable of fueling an AGN. Alternatively, the differences may be unrelated to
the presence or absence of an AGN and may simply reflect the possibility that
star formation in rings is episodic.Comment: accepted for publication in The Astrophysical Journal (10 January
1999); 48 pages including 13 figures; AAS LaTe
Telephone-Assisted, Parent-Mediated CBT for Rural Latino Youth With Anxiety: A Feasibility Trial
ObjectiveIn this study, we tailor a child anxiety cognitive-behavior therapy (CBT) program to fit the needs of rural Latino/a Spanish-speaking families and examine the feasibility, acceptability, tolerability, and safety of this intervention using 2 modes of service delivery.MethodChildren (n = 31; age 8-13) with anxiety disorders were recruited from primary care settings and randomized to 1 of 2 modes of parent-mediated CBT bibliotherapy: (1) telephone-delivered, therapist-assisted bibliotherapy (TTB; n = 15), and (2) a more minimal contact, self-directed, bibliotherapy condition (SB; n = 16). Independent evaluators administered a diagnostic interview at baseline and posttreatment; demographic and engagement-related questionnaires were also administered.ResultsIn the TTB group, 10 of 15 parents (66.7%) completed the requisite number of therapist-assisted bibliotherapy sessions, and in the SB group, 4 of 16 parents (25%) completed the requisite number of self-directed bibliotherapy modules; this comparison was significant, χ2(1) = 5.43, p = .02. In the TTB condition, treatment length and session duration were longer than reported in previous studies. Barriers that were most strongly endorsed were stressors and obstacles competing with treatment, as well as treatment demandingness. Findings revealed good satisfaction across the conditions, although ratings were significantly higher in the TTB group, F = 5.67, p = .028. Remission rates (i.e., no anxiety disorder) for those that provided posttreatment data (N = 25) were 50% and 36% for the TTB and SB groups, respectively, χ2(1) = .465, p = .50.ConclusionsImplications of these feasibility findings and suggestions for future research are discussed. (clinicaltrials.gov unique identifier: NCT01491880). (PsycINFO Database Recor
Templated self-assembly of gold nanoparticles in smectic liquid crystals confined at 3D printed curved surfaces
The fabrication of assembled structures of topological defects in liquid
crystals (LCs) has attracted much attention during the last decade, stemming
from the potential application of these defects in modern technologies. A range
of techniques can be employed to create large areas of engineered defects in
LCs, including mechanical shearing, chemical surface treatment, external
fields, or geometric confinement. The technology of 3D printing has recently
emerged as a powerful method to fabricate novel patterning topographies
inaccessible by other microfabrication techniques, especially confining
geometries with curved topographies. In this work, we show the advantages of
using 3D-printed curved surfaces and controlled anchoring properties to confine
LCs and engineer new structures of topological defects, whose structure we
elucidate by comparison with a novel application of Landau-de Gennes free
energy minimization to the smectic A-nematic phase transition. We also
demonstrate the ability of these defects to act as a scaffold for assembling
gold (Au) nanoparticles (NPs) into reconfigurable 3D structures. We discuss the
characteristics of this templated self-assembly (TSA) approach and explain the
relationship between NP concentrations and defect structures with insights
gained from numerical modeling. This work paves the way for a versatile
platform of LC defect-templated assembly of a range of functional nanomaterials
useful in the field of energy technology.Comment: Main text: 30 pages, 6 figures. Supplementary Information: 5 pages, 4
figure
Astrocyte development—More questions than answers
The past 15–20 years has seen a remarkable shift in our understanding of astrocyte contributions to central nervous system (CNS) function. Astrocytes have emerged from the shadows of neuroscience and are now recognized as key elements in a broad array of CNS functions. Astrocytes comprise a substantial fraction of cells in the human CNS. Nevertheless, fundamental questions surrounding their basic biology remain poorly understood. While recent studies have revealed a diversity of essential roles in CNS function, from synapse formation and function to blood brain barrier maintenance, fundamental mechanisms of astrocyte development, including their expansion, migration, and maturation, remain to be elucidated. The coincident development of astrocytes and synapses highlights the need to better understand astrocyte development and will facilitate novel strategies for addressing neurodevelopmental and neurological dysfunction. In this review, we provide an overview of the current understanding of astrocyte development, focusing primarily on mammalian astrocytes and highlight outstanding questions that remain to be addressed. We also include an overview of Drosophila glial development, emphasizing astrocyte-like glia given their close anatomical and functional association with synapses. Drosophila offer an array of sophisticated molecular genetic tools and they remain a powerful model for elucidating fundamental cellular and molecular mechanisms governing astrocyte development. Understanding the parallels and distinctions between astrocyte development in Drosophila and vertebrates will enable investigators to leverage the strengths of each model system to gain new insights into astrocyte function
Germinação de sementes e emergência de plântulas de Anadenanthera colubrina (Vell.) Brenan var. cebil (Griseb.) Altschut, Fabaceae, estabelecida em fragmentos florestais do Cerrado, MG
http://dx.doi.org/10.5902/1980509810541 The seed germination strategy is important for the survival of species, allowing their maintenance and regeneration in the environment. Seed germination and seedling emergence of Anadenanthera colubrina were studied to examine the reproductive efficiency of this species, typical of Cerrado biome. The fruits were collected in ‘Vale do Rio Araguari’, in MG state. The water content at 105 °C, the germination in controlled laboratory conditions and seedling emergence in semi-open greenhouse were analyzed. The seeds had low water content between 6.7 to 10.7%. The germinating ability and the emergence percentage were high for almost all studied individuals, being registered 68 for seeds of individual number 2 and 85 - 94% for the others; 38% (individual number 2) and 78 - 91% (for the others), respectively. The speed of the processes was high, with the end of germination within 12.8 days and emergence within 18.8 days. The processes were heterogeneous, with values of coefficient of variation of the germination or emergence time above 28.5%; asynchronous, with values of uncertainty above 1.5 bits and synchrony below 0.3812. The seeds of this species were efficient in both processes and the heterogeneity and asynchrony may indicate the effects of environmental fluctuations during the seed formation, besides the genetic variability, intrinsic to each individual of the population. The speed and the high potential of seed germination of this species may also facilitate the programs of reforestation with the production of large numbers of seedlings in short time. http://dx.doi.org/10.5902/1980509810541A estratégia de germinação dos diásporos é fundamental para a sobrevivência das espécies, sendo um dos fatores que permitem a sua manutenção e regeneração no ambiente. A germinação das sementes e a emergência das plântulas de Anadenanthera colubrina foram estudadas para analisar a eficiência reprodutiva da espécie, oriunda de fragmentos de vegetação do bioma Cerrado. Os frutos foram coletados no Vale do Rio Araguari, MG. O teor de água a 105ºC, a germinação em condições controladas de laboratório e a emergência das plântulas em estufa semiaberta, coberta com sombrite, foram analisados. As sementes apresentaram baixo teor de água, entre 6,7 e 10,7%. A germinabilidade e a porcentagem de emergência foram altas para quase todos os indivíduos estudados, estando entre 68 (indivíduo 2) e 85 - 94% (para os demais indivíduos); 38 (indivíduo 2) e 78 - 91% (para os demais), respectivamente. A velocidade dos processos foi alta, com o término da germinação dentro de 12,8 dias e emergência em 18,8 dias. Os processos foram heterogêneos, com valores do coeficiente de variação do tempo acima de 28,5%; assíncrono, sendo registrados valores acima de 1,5 bits para a incerteza e abaixo de 0,3812 para a sincronia. As sementes desta espécie se mostraram eficientes em ambos os processos e a heterogeneidade e assincronia podem ser indicativos dos efeitos das oscilações ambientais durante a formação das sementes, além da variabilidade genética, intrínseca de cada indivíduo da população. A rapidez e o alto potencial de germinação das sementes desta espécie também podem viabilizar programas de revegetação, com a produção de grande quantidade de plantas jovens em curto tempo
A amplitude amostral interfere nas medidas de germinação de Bowdichia virgilioides Kunth?
http://dx.doi.org/10.5902/1980509812346It is usual to find papers about seed germination of native species using different sample sizes. However, theconsequences of these procedures on the results are unknown. This study measured the germination processof Bowdichia virgilioides based on different seed sample sizes. The assay was conducted in a germinationchamber under continuous fluorescent white lamps and 26.2 ± 2.5 ºC. The design was completelyrandomized, as a 3 x 3 factorial (three sample sizes x three seed lots), with four replications per treatment.The sowing was done in gerbox, each one containing 25 seeds, making up 100, 200 and 400 seeds persample analyzed. Germinability, time (first, average and final), speed (mean germination rate and Maguire’sindex – VE or IVG), coefficient of variation of the germination time, uncertainty and synchrony of thegermination process were evaluated. Those seeds with embryo protrusion were considered germinated.Germination relative frequency graphics were also made. Among these measurements, the most fragile to size sample were VE and the uncertainty. VE was also influenced by the relation between germinability andmean germination rate, demonstrating its instability to measure the speed of the germination process whenthe lots have different germination capacity. Results of time measurements, uniformity, mean germinationrate and germinability were not affected by seed sample size. Germinability, however, was the most stablegermination measurement, and was not affected by sample size, even when analyzed by seed lots with verydiscrepant quality.http://dx.doi.org/10.5902/1980509812346É comum encontrar na literatura trabalhos sobre germinação de sementes nativas de uma mesma espécie com tamanhos de amostra diferenciados. No entanto, não se sabe quais são as consequências disso para os resultados obtidos. Assim, objetivou-se estudar o comportamento das medidas de germinação frente à variação do número de sementes que compõe a amostra para Bowdichia virgilioides. O experimento foi conduzido em câmara de germinação, sob luz branca fluorescente contínua, a 26,2 ± 2,5 ºC. O delineamento utilizado foi o inteiramente casualizado, em esquema fatorial 3 x 3 (três tamanhos de amostra x três lotes), com número de repetições fixo e igual a quatro. A semeadura foi realizada em caixas tipo gerbox, contendo 25, 50 ou 100 sementes, perfazendo 100, 200 ou 400 sementes por amostra. A germinabilidade, tempo inicial, médio e final, velocidade média e VE (IVG), coeficiente de variação do tempo, incerteza e sincronia da germinação foram avaliados, sendo consideradas germinadas as sementes com protrusão de embrião. Gráficos de frequência relativa também foram construídos. Dentre estas medidas, as mais frágeis ao incremento do tamanho da amostra foram o VE e a incerteza. O VE, além de ser influenciado pelo tamanho da amostra, também foi influenciado pelo contrabalancear entre germinabilidade e velocidade média, demonstrando ser uma medida imprópria para mensurar velocidade de germinação quando a capacidade germinativa dos lotes for diferente. As medidas de tempo, uniformidade, sincronia, velocidade média e a germinabilidade não tiveram seus resultados afetados pelos diferentes tamanhos da amostra. A germinabilidade, entretanto, mostrou-se a medida mais estável do processo germinativo, não sendo influenciada pelo tamanho da amostra, mesmo quando analisada por meio de lotes com qualidades muito discrepantes
Juvenile neurogenesis makes essential contributions to adult brain structure and plays a sex-dependent role in fear memories
Postnatal neurogenesis (PNN) contributes neurons to olfactory bulb (OB) and dentate gyrus (DG) throughout juvenile development, but the quantitative amount, temporal dynamics and functional roles of this contribution have not been defined. By using transgenic mouse models for cell lineage tracing and conditional cell ablation, we found that juvenile neurogenesis gradually increased the total number of granule neurons by approximately 40% in OB, and by 25% in DG, between 2 weeks and 2 months of age, and that total numbers remained stable thereafter. These findings indicate that the overwhelming majority of net postnatal neuronal addition in these regions occurs during the juvenile period and that adult neurogenesis contributes primarily to replacement of granule cells in both regions. Behavioral analysis in our conditional cell ablation mouse model showed that complete loss of PNN throughout both the juvenile and young adult period produced a specific set of sex-dependent cognitive changes. We observed normal hippocampus-independent delay fear conditioning, but excessive generalization of fear to a novel auditory stimulus, which is consistent with a role for PNN in psychopathology. Standard contextual fear conditioning was intact, however, pre-exposure dependent contextual fear was impaired suggesting a specific role for PNN in incidental contextual learning. Contextual discrimination between two highly similar contexts was enhanced; suggesting either enhanced contextual pattern separation or impaired temporal integration. We also observed a reduced reliance on olfactory cues, consistent with a role for OB PNN in the efficient processing of olfactory information. Thus, juvenile neurogenesis adds substantively to the total numbers of granule neurons in OB and DG during periods of critical juvenile behavioral development, including weaning, early social interactions and sexual maturation, and plays a sex-dependent role in fear memories
Dormência múltipla e efeito maternal na germinação de sementes de Miconia ferruginata (Melastomataceae), Serra de Caldas Novas, Goiás, Brasil
Species with mostly asexual reproduction are interesting subjects for germination studies since variation would be more easily linked to environmental factors. Miconia ferruginata DC. is an apomictic treelet in Brazilian cerrado areas on rocky outcrops. Germination of seeds collected from individuals occurring in the Serra de Caldas Novas State Park, Goiás, was studied in three experiments under controlled conditions. Germination characteristics differed among individuals and were correlated with altitude and soil Al content. Seeds from plants growing at lower altitudes, with lower soil aluminium content, presented malformed seeds with absence of embryo which rendered lower, but better synchronized germination. The nested analysis showed that from the total variance, 78.14% for germinability, 54.56% for uncertainty of the germination process, and 68.30% for the quantity of seeds without embryo was attributed to the altitudinal effect. Individuals nested within altitude contributed up to 16.93% for the total variance. It means that there is low variability among individuals of the same altitude and high variability among individuals from different points of the slope, making clear that for the studied population the environmental effect is stronger than the genetic component to determine the seed quality. The testa of the seeds provides a mechanical dormancy which seems to be associated also with phenolic compounds, which help to disperse germination through time. Photoblastism was also registered for seeds of this species.Espécies com reprodução principalmente assexuada são interessantes para estudos de germinação, uma vez que a variação pode ser mais facilmente associada a fatores ambientais. Miconia ferruginata DC. é um arbusto apomítico de cerrado rupestre brasileiro. A germinação de sementes coletadas no Parque Estadual da Serra de Caldas Novas, Goiás foi estudada em três experimentos sob condições de laboratório. O processo de germinação diferiu entre os indivíduos, correlacionando-se com altitude e teor de Al do solo. Sementes oriundas de plantas crescendo nas menores altitudes, com menor teor de alumínio no solo, apresentaram sementes mal formadas, com ausência de embrião, resultando em baixa germinabilidade, mas maior sincronia de germinação. A análise hierárquica mostrou que 78,14% da variabilidade na germinabilidade, 54,56% na incerteza e 68,30% na quantidade de sementes sem embrião foram atribuídos ao efeito altitudinal. Indivíduos agrupados dentro de altitude contribuíram até 16,93% para a variância total. Isto significa que há baixa variabilidade entre indivíduos da mesma altitude e alta variabilidade entre indivíduos de diferentes pontos da Serra, indicando que para a população estudada o efeito ambiental é mais forte do que o componente genético para determinar a qualidade das sementes. A testa das sementes propiciou dormência mecânica que parece estar associada com a presença de compostos fenólicos, o que ajuda a dispersar a germinação no tempo. Fotoblastismo também foi registrado para sementes dessa espécie.92105Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
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