201 research outputs found
Diel and seasonal timing of sound production by black drum (Pogonias cromis)
Acoustic recorders were used to document black drum (Pogonias cromis) sound production during their spawning season in southwest Florida. Diel patterns of sound production were similar to those of other sciaenid fishes and demonstrated increased sound levels from the late afternoon to early evening—a period that lasted up to 12 hours during peak season. Peak sound production occurred from January through March when water temperatures were between 18° and 22°C. Seasonal trends in sound production
matched patterns of black drum reproductive readiness and spawning reported previously for populations in the Gulf of Mexico. Total acoustic energy of nightly chorus events was
estimated by integration of the sound pressure amplitude with duration above a threshold based on daytime background levels. Maximum chorus sound level was highly correlated with total acoustic energy and was used to quantitatively represent nightly black drum sound production. This study
gives evidence that long-term passive acoustic recordings can provide information on the timing and location of black drum reproductive behavior that is similar to that provided by traditional, more costly methods. The methods and results have broad application for the study of many other
fish species, including commercially and recreationally valuable reef fishes that produce sound in association with
reproductive beha
Dietary Habits of the Gafftopsail Catfish, Bagre marinus, in Tarpon Bay and Pine Island South, Florida
A total of 507 gafftopsail catfish, Bagre marinus, were captured by hook and line in Tarpon Bay and neighboring Pine Island Sound, Florida from June 3, 1999 to May 6, 2000 in order to identify foods of this understudied species. A total of 86 (17.0%) specimens contained only unidentifiable food, and 187 (36.9%) specimens were found with empty stomachs. Based on the index of relative importance, the pink shrimp, Farfantepenaeus duorarum, was the most important food for specimens ≤200 mm fork length (FL), amphipods the most important food for specimens 201-300 mm FL, and unidentifiable fish the most important food for specimens ≥301 mm FL. Diet of B. marinus was also compared among four seasons: June through August; September through November, December through February, and March through May. Unidentifiable fish was the most important food for June through August and September through November. Clupeid fishes were the most important food for December through February. The amphipod Ampelisca abdita was the most important food for March through May. The wide variety of foods consumed by B. marinus indicates an opportunistic feeding strategy
A Comparison of Macroepifauna Among Vegetated and Unvegetated Habitats in a South Florida Estuary Using a Passive Sampling Gear
We compared abundance, richness, diversity, and community structure of macroepifauna among the seagrasses Halodule wrightii, Thalassia testudinum, and Syringodium filiforme, and unvegetated substrate in Tarpon Bay, Caloosahatchee River estuary, Florida. Sampling was conducted using wire-mesh minnow traps deployed over fifty-six 24-h periods from Jan. 1999 to Jan. 2000. A total of 36, 35, 28, and 28 species were identified from Halodule, Thalassia, Syringodium, and unvegetated samples, respectively. The gastropod Nassarius vibex was the most abundant species from Halodule and unvegetated substrate, whereas the pinfish (Lagodon rhomboides) was the most abundant species from Thalassia and Syringodium. Abundance of these codominant species varied seasonally throughout the study. For all taxa combined and for codominants, each seagrass contained greater averages than unvegetated substrate in each season. Seagrasses typically had higher average species richness and diversity than unvegetated substrate in each season. Results indicate that Tarpon Bay typifies subtropical estuaries in that its epifaunal community is dominated by few species, faunal abundances vary seasonally, and more organisms are found in seagrasses than in unvegetated areas. Our results serve as a foundation to compare against future research in an understudied system
Evolving training sets for improved transfer learning in brain computer interfaces
A new proof-of-concept method for optimising the performance of Brain Computer Interfaces (BCI) while minimising the quantity of required training data is introduced. This is achieved by using an evolutionary approach to rearrange the distribution of training instances, prior to the construction of an Ensemble Learning Generic Information (ELGI) model. The training data from a population was optimised to emphasise generality of the models derived from it, prior to a re-combination with participant-specific data via the ELGI approach, and training of classifiers. Evidence is given to support the adoption of this approach in the more difficult BCI conditions: smaller training sets, and those suffering from temporal drift. This paper serves as a case study to lay the groundwork for further exploration of this approach
The potential role of podoplanin in tumour invasion
Podoplanin is a small mucin-like transmembrane protein, widely expressed in various specialised cell types throughout the body. Here, we revisit the mechanism of podoplanin-mediated tumour invasion. We compare molecular pathways leading to single and collective cell invasion and discuss novel distinct concepts of tumour cell invasion
Carbon Sequestration in Synechococcus Sp.: From Molecular Machines to Hierarchical Modeling
The U.S. Department of Energy recently announced the first five grants for the Genomes to Life (GTL) Program. The goal of this program is to "achieve the most far-reaching of all biological goals: a fundamental, comprehensive, and systematic understanding of life." While more information about the program can be found at the GTL website (www.doegenomestolife.org), this paper provides an overview of one of the five GTL projects funded, "Carbon Sequestration in Synechococcus Sp.: From Molecular Machines to Hierarchical Modeling." This project is a combined experimental and computational effort emphasizing developing, prototyping, and applying new computational tools and methods to ellucidate the biochemical mechanisms of the carbon sequestration of Synechococcus Sp., an abundant marine cyanobacteria known to play an important role in the global carbon cycle. Understanding, predicting, and perhaps manipulating carbon fixation in the oceans has long been a major focus of biological oceanography and has more recently been of interest to a broader audience of scientists and policy makers. It is clear that the oceanic sinks and sources of CO2 are important terms in the global environmental response to anthropogenic atmospheric inputs of CO2 and that oceanic microorganisms play a key role in this response. However, the relationship between this global phenomenon and the biochemical mechanisms of carbon fixation in these microorganisms is poorly understood. The project includes five subprojects: an experimental investigation, three computational biology efforts, and a fifth which deals with addressing computational infrastructure challenges of relevance to this project and the Genomes to Life program as a whole. Our experimental effort is designed to provide biology and data to drive the computational efforts and includes significant investment in developing new experimental methods for uncovering protein partners, characterizing protein complexes, identifying new binding domains. We will also develop and apply new data measurement and statistical methods for analyzing microarray experiments. Our computational efforts include coupling molecular simulation methods with knowledge discovery from diverse biological data sets for high-throughput discovery and characterization of protein-protein complexes and developing a set of novel capabilities for inference of regulatory pathways in microbial genomes across multiple sources of information through the integration of computational and experimental technologies. These capabilities will be applied to Synechococcus regulatory pathways to characterize their interaction map and identify component proteins in these pathways. We will also investigate methods for combining experimental and computational results with visualization and natural language tools to accelerate discovery of regulatory pathways. Furthermore, given that the ultimate goal of this effort is to develop a systems-level of understanding of how the Synechococcus genome affects carbon fixation at the global scale, we will develop and apply a set of tools for capturing the carbon fixation behavior of complex of Synechococcus at different levels of resolution. Finally, because the explosion of data being produced by high-throughput experiments requires data analysis and models which are more computationally complex, more heterogeneous, and require coupling to ever increasing amounts of experimentally obtained data in varying formats, we have also established a companion computational infrastructure to support this effort as well as the Genomes to Life program as a whole.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63164/1/153623102321112746.pd
The lactose operon from Lactobacillus casei is involved in the transport and metabolism of the human milk oligosaccharide core-2 N-acetyllactosamine
The lactose operon (lacTEGF) from Lactobacillus casei strain BL23 has been previously studied. The lacT gene codes for a transcriptional antiterminator, lacE and lacF for the lactose-specific phosphoenolpyruvate: phosphotransferase system (PTSLac) EIICB and EIIA domains, respectively, and lacG for the phospho-β-galactosidase. In this work, we have shown that L. casei is able to metabolize N-acetyllactosamine (LacNAc), a disaccharide present at human milk and intestinal mucosa. The mutant strains BL153 (lacE) and BL155 (lacF) were defective in LacNAc utilization, indicating that the EIICB and EIIA of the PTSLac are involved in the uptake of LacNAc in addition to lactose. Inactivation of lacG abolishes the growth of L. casei in both disaccharides and analysis of LacG activity showed a high selectivity toward phosphorylated compounds, suggesting that LacG is necessary for the hydrolysis of the intracellular phosphorylated lactose and LacNAc. L. casei (lacAB) strain deficient in galactose-6P isomerase showed a growth rate in lactose (0.0293 ± 0.0014 h-1) and in LacNAc (0.0307 ± 0.0009 h-1) significantly lower than the wild-type (0.1010 ± 0.0006 h-1 and 0.0522 ± 0.0005 h-1, respectively), indicating that their galactose moiety is catabolized through the tagatose-6P pathway. Transcriptional analysis showed induction levels of the lac genes ranged from 130 to 320-fold in LacNAc and from 100 to 200-fold in lactose, compared to cells growing in glucose
11β-HSD1 plays a critical role in trabecular bone loss associated with systemic glucocorticoid therapy
Background: Despite their efficacy in the treatment of chronic inflammation, the prolonged application of therapeutic glucocorticoids (GCs) is limited by significant systemic side effects including glucocorticoid-induced osteoporosis (GIOP). 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a bi-directional enzyme that primarily activates GCs in vivo, regulating tissue-specific exposure to active GC. We aimed to determine the contribution of 11β-HSD1 to GIOP. Methods: Wild type (WT) and 11β-HSD1 knockout (KO) mice were treated with corticosterone (100 μg/ml, 0.66% ethanol) or vehicle (0.66% ethanol) in drinking water over 4 weeks (six animals per group). Bone parameters were assessed by micro-CT, sub-micron absorption tomography and serum markers of bone metabolism. Osteoblast and osteoclast gene expression was assessed by quantitative RT-PCR. Results: Wild type mice receiving corticosterone developed marked trabecular bone loss with reduced bone volume to tissue volume (BV/TV), trabecular thickness (Tb.Th) and trabecular number (Tb.N). Histomorphometric analysis revealed a dramatic reduction in osteoblast numbers. This was matched by a significant reduction in the serum marker of osteoblast bone formation P1NP and gene expression of the osteoblast markers Alp and Bglap. In contrast, 11β-HSD1 KO mice receiving corticosterone demonstrated almost complete protection from trabecular bone loss, with partial protection from the decrease in osteoblast numbers and markers of bone formation relative to WT counterparts receiving corticosterone. Conclusions: This study demonstrates that 11β-HSD1 plays a critical role in GIOP, mediating GC suppression of anabolic bone formation and reduced bone volume secondary to a decrease in osteoblast numbers. This raises the intriguing possibility that therapeutic inhibitors of 11β-HSD1 may be effective in preventing GIOP in patients receiving therapeutic steroids
A Multicassette Gateway Vector Set for High Throughput and Comparative Analyses in Ciona and Vertebrate Embryos
BACKGROUND: The past few years have seen a vast increase in the amount of genomic data available for a growing number of taxa, including sets of full length cDNA clones and cis-regulatory sequences. Large scale cross-species comparisons of protein function and cis-regulatory sequences may help to understand the emergence of specific traits during evolution. PRINCIPAL FINDINGS: To facilitate such comparisons, we developed a Gateway compatible vector set, which can be used to systematically dissect cis-regulatory sequences, and overexpress wild type or tagged proteins in a variety of chordate systems. It was developed and first characterised in the embryos of the ascidian Ciona intestinalis, in which large scale analyses are easier to perform than in vertebrates, owing to the very efficient embryo electroporation protocol available in this organism. Its use was then extended to fish embryos and cultured mammalian cells. CONCLUSION: This versatile vector set opens the way to the mid- to large-scale comparative analyses of protein function and cis-regulatory sequences across chordate evolution. A complete user manual is provided as supplemental material
CaracterÃsticas quÃmicas de um latossolo adubado com uréia e cloreto de potássio em ambiente protegido
A produção de vegetais mais sadios e de boa qualidade e o fornecimento contÃnuo no mercado são fatores que têm determinado a adoção do sistema de cultivo protegido por um número maior de produtores. Porém, devido ao pouco conhecimento sobre o manejo do solo nessas condições, tem-se aplicado altas doses de fertilizantes, ocasionando problemas de salinidade e desequilÃbrio nutricional. O objetivo desse trabalho foi avaliar os efeitos da aplicação da uréia e do cloreto de potássio nas caracterÃsticas quÃmicas de um LATOSSOLO VERMELHO Destrófico, principalmente nos Ãndices de acidez e saturação em potássio. O N e o K foram aplicados em cobertura, nas doses equivalentes de 13,3 e 39,9 g m-2 de N e 5,5 e 16,6 g m-2 de K, em esquema fatorial (2x2+1), com tratamento adicional, sem a aplicação dos nutrientes. Cultivou-se pimentão, cultivar Mayata, em condições de ambiente protegido, durante 34 semanas. Após o pegamento das mudas, foi aplicado 1/6 dos nutrientes a cada dez dias. Ao final do ciclo, as formas de N nÃtrico e N amoniacal representaram melhor as doses do nutriente aplicados ao solo e não houve acidificação. As raÃzes tiveram significativo crescimento após a aplicação de N, enquanto que o aumento da dose de K, aplicado como KCl, prejudicou o crescimento radicular, provavelmente associado à alta concentração de K no solo e possÃveis efeitos salinos, correspondendo a mais de 5,0 mmol c dm-3 e mais que 5,3% de saturação do K no complexo de troca, na camada superficial do solo
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