Adaptations to Host Infection and Larval Parasitism in Unionoida

Freshwater mussel larval parasitism of fish is unique among bivalves. The relationship is primarily phoretic rather than nutritive; only the smallest glochidia and the haustorial larva grow substantially while on the host. Growth of the smallest larvae suggests a lower functional size limit of ∼150 μm for the juvenile stage. Most Ambleminae, the most diverse North American clade, infect host gills by attracting feeding fish. Many species of Pleurobemini and some Lampsilini release conglutinates of eggs and larvae that resemble host food items. Many Lampsilini and a few Quadrulini use mantle modifications to attract host fish to the female. The mantle of some Quadrulini forms a posterior chamber that holds glochidia for immediate release in response to host fish. In many Lampsilini, mantle flap lures and a protrusible marsupium promote attack by the host fish and direct extraction of glochidia from the marsupium by the host. Host extraction of glochidia from the brooding female might have favored the evolution of long-term brooding in Lampsilini because glochidia need not be released by the female to encounter the host. A remarkable derivative of the host extraction strategy evolved in Epioblasma, which catch fish between the valves and release glochidia directly to the trapped host before releasing it. Host specificity is a critical feature of the evolutionary diversification and conservation biology of Unionoida. As temporary parasites, mussels must primarily evade the innate immune responses of the host, rather than the adaptive (acquired) responses. Evolution of host specificity is associated with selective encounter of host taxa, either because of host attraction strategies or because of dominance of particular host species in the habitat. The intricate relationships between mussels and fish are easily disrupted and, thus, contribute to the imperilment of many mussel species, yet they also fascinate us and compel conservation efforts

Uso de leitos cultivados no tratamento de efluentes da aquicultura.

In the last fifty years, worldwide aquaculture has increased about 8.8% /year. In Brazil, the tilapia culture, the flagship aquaculture production, represents 39% of the total cultivated fish. The increasing demand for aquatic protein, the demographic increasement and the decline of natural stocks have contributed to the promotion of aquaculture around the world. Nevertheless, concerns about the negative environmental impacts caused by this activity are also increasing. Some of these impacts are: destruction of mangroves, significant inputs of nitrogen, phosphorus and organic matter downstream nurseries, invasion of exotic species in natural aquatic ecosystems. Natural treatment systems such as constructed wetlands are costeffective, do not depend on energy, and the efficiency of removal of the main physico-chemical parameters of water quality are at 70 to 90% on average. By bacteriological metabolism and mechanical filtration, the organic matter is used as food and nutrient for aquatic plants. This study aims to assess the efficiency of constructed wetlands for treatment of effluents from tilapia culture, using a closed cycle of water. At Embrapa Environment (Jaguariúna, SP), a system composed by 54 plastic boxes was constructed to test three kinds of substrates: pebbles, expanded clay and a mixture of both. The plant Vetiver was used as another part of the treatment system. We expect to verify a great reduction in important parameters such as total nitrogen, total phosphorus, biochemical oxygen demand, total suspended solids and others. This system could be very useful at smallholder aquaculture worried with best management practices

Student Understanding of DNA Structure–Function Relationships Improves from Using 3D Learning Modules with Dynamic 3D Printed Models

Understanding the relationship between molecular structure and function represents an important goal of undergraduate life sciences. Although evidence suggests that handling physical models supports gains in student understanding of structure–function relationships, such models have not been widely implemented in biochemistry classrooms. Three-dimensional (3D) printing represents an emerging cost-effective means of producing molecular models to help students investigate structure–function concepts. We developed three interactive learning modules with dynamic 3D printed models to help biochemistry students visualize biomolecular structures and address particular misconceptions. These modules targeted specific learning objectives related to DNA and RNA structure, transcription factor-DNA interactions, and DNA supercoiling dynamics. We also designed accompanying assessments to gauge student learning. Students responded favorably to the modules and showed normalized learning gains of 49% with respect to their ability to understand and relate molecular structures to biochemical functions. By incorporating accurate 3D printed structures, these modules represent a novel advance in instructional design for biomolecular visualization. We provide instructors with the materials necessary to incorporate each module in the classroom, including instructions for acquiring and distributing the models, activities, and assessments. 9 supplemental files attached (below

Avaliação de um sistema de leito cultivado com recirculação para piscicultura.

Resumo: O presente estudo teve como objetivo avaliar a eficiência de leitos cultivados de fluxo subsuperficial no tratamento do efluente de piscicultura da tilápia-do-nilo (Oreochromis niloticus) em escala piloto, com ciclo fechado de água. Para tanto, foi construído um sistema de leitos cultivados composto por três unidades com os seguintes tipos de meio suporte: brita, argila expandida e uma mistura homogênea de ambos os substratos, denominada MIX. Estes meios suportes foram avaliados com e sem a presença da planta vetiver (Chrysopogon zizanioides). A eficiência dos leitos foi medida por avaliações de parâmetros físicoquímicos da água bruta e tratada, além do desempenho da planta vetiver no tratamento da água. Os resultados indicam que o meio suporte composto de brita com vetiver apresentou melhor eficiência como tratamento do efluente de piscicultura considerando a avaliação da qualidade da água, principalmente para os parâmetros: pH (próximo da neutralidade - 6,55), condutividade elétrica (0,49 mS/cm), e nitrogênio total (0,086 mg/L), com maior percentual de redução após o tratamento, onde a brita em associação com o vetiver apresentou redução de 85% do nitrogênio total. Tais resultados reforçam o potencial deste sistema para uso por piscicultores, pois emprega materiais de custo relativamente baixo, porém com elevada eficiência na redução de parâmetros críticos para a piscicultura. Abstract: The present study aimed to evaluate the efficiency of subsurface flow constructed wetlands to treat effluent from fish farming of nile tilapia (Oreochromis niloticus) in pilot scale with closed water cycle. To this end, it set up a system of constructed wetlands consisting of three types of support media: gravel, expanded clay and a homogeneous mixture of both substrates, called MIX. These support media were tested with and without the association with the plant vetiver (Chrysopogon zizanioides). The performance of the beds was measured by assessments of physical-chemical parameters of effluent and treated water, besides the performance of the vetiver plant in water filtration. The results indicate that the gravel bed associated with the plant vetiver performed better for the quality of the treated water for pH (closer to neutrality ? 6,55), electric conductivity (0,49 mS/cm) and total nitrogen (0,086 mg/L) (highest percentage reduction after treatment). The gravel in association with vetiver showed a reduction of 85% of the total nitrogen. These results reinforce the potential of this system for use by fish farmers, since it uses materials of relatively low cost but with high efficiency in the reduction of critical parameters for fish farming.bitstream/item/160850/1/BP-71-Mariana.pd

Preliminary assessment of diffused loads from rural areas in a sub-basin of the Jaguari River, SP, Brazil

Official water quality and flow data from Jaguari River were used to assess the diffused loads of nutrients from rural areas into surface waters. Mathematical models of mean daily loads of total nitrogen (TN) and total phosphorus (TP) were generated through the application of simple statistical procedures to field data collected from 1999 to 2002. The models obtained were validated with field data collected from 1996 to 1998. The application of the model showed that, on average, 68.2% of the TN annual loads and 77.3% of the TP annual loads were transported through the sub-basin during the raining season. Assuming the mean baseflow loads as 1706.5 kg TN d-1 and 165.7 kg TP d-1, the annual diffused loads obtained - primarily from rural sources - were equivalent to 55.1 and 69.4% of the total annual loads of TN and TP transported through the sub - basin, respectively. The mean export coefficients from diffused loads for TN and TP were equal to 230 and 40 kg km-2 year-1, respectively. In may be concluded that controlling the diffused loads of TP from rural areas should decrease the high concentrations observed.Dados oficiais de concentração de nutrientes e vazão do Rio Jaguari, foram utilizados na avaliação das contribuições difusas, com origem rural, às águas superficiais de uma sub-bacia do Rio Jaguari, SP. Modelos de cargas médias diárias de Ntotal e Ptotal foram gerados a partir de regressão estatística aplicada a dados de campo obtidos entre 1999 e 2002. A validação dos modelos foi feita utilizando-se dados de campo obtidos entre 1996 e 1998. O modelo mostrou que, em média, 68,2% das cargas anuais de Ntotal e 77,3% das cargas anuais de Ptotal foram transportados pela sub-bacia no período chuvoso. Partindo-se de cargas de base diárias de 1706,5 kg Ntotal e de 165,7 kg Ptotal, determinou-se que 55,1 e 69,4% das cargas anuais totais de Ntotal e Ptotal, respectivamente, transportadas pela sub-bacia, provieram de fontes difusas. As taxas de exportação de nutrientes por carga difusa, obtidas pela aplicação do modelo, foram iguais a 230 kg Ntotal km-2 ano-1 e 40 kg Ptotal km-2 ano-1. Concluiu-se que o controle das fontes difusas de Ptotal, a partir de áreas rurais, deverá diminuir as concentrações deste nutriente no Rio Jaguari.715723Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Validação de método analítico para quantificação de interferentes endócrinos em águas residuárias após tratamento secundário.

Interferentes endócrinos são substâncias que estão cada vez mais presentes no meio ambiente, especialmente nos corpos hídricos, que podem causar câncer em seres humanos e animais, mutagenicidade nos órgãos reprodutores das espécies animais presentes na biota aquática, esterilidade em homens, entre outros efeitos adversos à saúde. Constructed wetlands são métodos alternativos de tratamento de água e efluentes, que se baseiam na retirada de poluentes pelas macrófitas aquáticas e pelo biofilme formado nas raízes das plantas fixadas ao meio suporte, simulando assim os sistemas naturais de tratamento. Eles têm como vantagem o baixo custo de implantação e manutenção, economia de energia elétrica durante seu funcionamento, além de serem eficientes na remoção de poluentes. Constructed wetlands foram citados como um eficiente método de remoção de pesticidas levemente hidrofóbicos. Neste contexto, devido ao fato de estrogênios serem substâncias levemente hidrofóbicas, o presente trabalho visou desenvolver e validar uma metodologia de análise cromatográfica para determinação quantitativa dos hormônios etinilestradiol (EE2) e levonorgestrel (LEV), e do composto químico bisfenol A (BPA) em águas residuárias após tratamento secundário, com o intuito de analisar esses compostos no afluente e efluente de uma wetland construída em escala laboratorial

Levantamento dos fatores que condicionam o uso da biblioteca da Faculdade de Educação, Filosofia, Ciências Sociais e da Documentação da UNESP, Campus de Marília (SP)

Detecta fatores condicionantes do uso da biblioteca em questão, caracterizados em: aspectos físicos, comunicação entre funcionários e usuários, profissionalismo, opções de lazer por parte dos usuários e suas preferências em relação a jogos e esportes. Optou-se pela literatura da área de Psicologia, para maior compreensão do comportamento dos indivíduos, já que as experiências oferecem dados - estímulos - dos quais apreendem-se suas sensações. Quando agradáveis, deseja-se repetí-las, e ocorre afastamento das pessoas quando estas per­cebem situações desagradáveis. Aplicou-se um questionário na população da B/FEFCSD, composta por 682 elementos, obtendo-se um retorno de 76,09% do instrumento de coleta de dados. Verificou-se a existência de algumas barreiras inexpressivas nas variáveis testadas, embora aquelas importem para a Biblioteca, que se vale de modelo promotivo, isto é, máxima exploração dos serviços em benefício da comunidade a que serve. Mediante os resultados e conclusões, sugere-se: um estudo de adequação da coleção; intensificação dos cursos de capacitação dos usuários reais e potenciais para melhor aproveitamento dos recursos da biblioteca; maior embasamento nas diretrizes oriundas da área da Relações Humanas; análise, projeção e implementação de uma sala de jogos, incitada pela biblioteca, bem como incentivo às práticas desportivas.

Catecholaminergic polymorphic ventricular tachycardia patients with multiple genetic variants in the PACES CPVT Registry.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is often a life-threatening arrhythmia disorder with variable penetrance and expressivity. Little is known about the incidence or outcomes of CPVT patients with ≥2 variants. METHODS: The phenotypes, genotypes and outcomes of patients in the Pediatric and Congenital Electrophysiology Society CPVT Registry with ≥2 variants in genes linked to CPVT were ascertained. The American College of Medical Genetics & Genomics (ACMG) criteria and structural mapping were used to predict the pathogenicity of variants (3D model of pig RyR2 in open-state). RESULTS: Among 237 CPVT subjects, 193 (81%) had genetic testing. Fifteen patients (8%) with a median age of 9 years (IQR 5-12) had ≥2 variants. Sudden cardiac arrest occurred in 11 children (73%), although none died during a median follow-up of 4.3 years (IQR 2.5-6.1). Thirteen patients (80%) had at least two RYR2 variants, while the remaining two patients had RYR2 variants plus variants in other CPVT-linked genes. Among all variants identified, re-classification of the commercial laboratory interpretation using ACMG criteria led to the upgrade from variant of unknown significance (VUS) to pathogenic/likely pathogenic (P/LP) for 5 variants, and downgrade from P/LP to VUS for 6 variants. For RYR2 variants, 3D mapping using the RyR2 model suggested that 2 VUS by ACMG criteria were P/LP, while 2 variants were downgraded to likely benign. CONCLUSIONS: This severely affected cohort demonstrates that a minority of CPVT cases are related to ≥2 variants, which may have implications on family-based genetic counselling. While multi-variant CPVT patients were at high-risk for sudden cardiac arrest, there are insufficient data to conclude that this genetic phenomenon has prognostic implications at present. Further research is needed to determine the significance and generalizability of this observation. This study also shows that a rigorous approach to variant re-classification using the ACMG criteria and 3D mapping is important in reaching an accurate diagnosis, especially in the multi-variant population

Left Ventricular Systolic Dysfunction in Patients Diagnosed With Hypertrophic Cardiomyopathy During Childhood: Insights From the SHaRe Registry.

BACKGROUND: The development of left ventricular systolic dysfunction (LVSD) in hypertrophic cardiomyopathy (HCM) is rare but serious and associated with poor outcomes in adults. Little is known about the prevalence, predictors, and prognosis of LVSD in patients diagnosed with HCM as children. METHODS: Data from patients with HCM in the international, multicenter SHaRe (Sarcomeric Human Cardiomyopathy Registry) were analyzed. LVSD was defined as left ventricular ejection fraction <50% on echocardiographic reports. Prognosis was assessed by a composite of death, cardiac transplantation, and left ventricular assist device implantation. Predictors of developing incident LVSD and subsequent prognosis with LVSD were assessed using Cox proportional hazards models. RESULTS: We studied 1010 patients diagnosed with HCM during childhood (<18 years of age) and compared them with 6741 patients with HCM diagnosed as adults. In the pediatric HCM cohort, median age at HCM diagnosis was 12.7 years (interquartile range, 8.0-15.3), and 393 (36%) patients were female. At initial SHaRe site evaluation, 56 (5.5%) patients with childhood-diagnosed HCM had prevalent LVSD, and 92 (9.1%) developed incident LVSD during a median follow-up of 5.5 years. Overall LVSD prevalence was 14.7% compared with 8.7% in patients with adult-diagnosed HCM. Median age at incident LVSD was 32.6 years (interquartile range, 21.3-41.6) for the pediatric cohort and 57.2 years (interquartile range, 47.3-66.5) for the adult cohort. Predictors of developing incident LVSD in childhood-diagnosed HCM included age <12 years at HCM diagnosis (hazard ratio [HR], 1.72 [CI, 1.13-2.62), male sex (HR, 3.1 [CI, 1.88-5.2), carrying a pathogenic sarcomere variant (HR, 2.19 [CI, 1.08-4.4]), previous septal reduction therapy (HR, 2.34 [CI, 1.42-3.9]), and lower initial left ventricular ejection fraction (HR, 1.53 [CI, 1.38-1.69] per 5% decrease). Forty percent of patients with LVSD and HCM diagnosed during childhood met the composite outcome, with higher rates in female participants (HR, 2.60 [CI, 1.41-4.78]) and patients with a left ventricular ejection fraction <35% (HR, 3.76 [2.16-6.52]). CONCLUSIONS: Patients with childhood-diagnosed HCM have a significantly higher lifetime risk of developing LVSD, and LVSD emerges earlier than for patients with adult-diagnosed HCM. Regardless of age at diagnosis with HCM or LVSD, the prognosis with LVSD is poor, warranting careful surveillance for LVSD, especially as children with HCM transition to adult care

Unraveling the role of protein dynamics in dihydrofolate reductase catalysis

Protein dynamics have controversially been proposed to be at the heart of enzyme catalysis, but identification and analysis of dynamical effects in enzyme-catalyzed reactions have proved very challenging. Here, we tackle this question by comparing an enzyme with its heavy (15N, 13C, 2H substituted) counterpart, providing a subtle probe of dynamics. The crucial hydride transfer step of the reaction (the chemical step) occurs more slowly in the heavy enzyme. A combination of experimental results, quantum mechanics/molecular mechanics simulations, and theoretical analyses identify the origins of the observed differences in reactivity. The generally slightly slower reaction in the heavy enzyme reflects differences in environmental coupling to the hydride transfer step. Importantly, the barrier and contribution of quantum tunneling are not affected, indicating no significant role for “promoting motions” in driving tunneling or modulating the barrier. The chemical step is slower in the heavy enzyme because protein motions coupled to the reaction coordinate are slower. The fact that the heavy enzyme is only slightly less active than its light counterpart shows that protein dynamics have a small, but measurable, effect on the chemical reaction rate