Percentages of cooled Artemia Nauplii for pacam? larvae culture

Todos os textos, informa??es e resultados apresentados s?o de inteira responsabilidade dos autores.O pacam? ? uma esp?cie nativa e end?mica da bacia hidrografia do Rio S?o Francisco. Os n?uplios de Artemia sp. constituem um importante insumo, principalmente para a cria??o de larvas de peixes, de camar?es marinhos e de ?gua doce. Portanto o objetivo desse trabalho foi avaliar diferentes porcentagens de n?uplios de Artemia sp.resfriada na alimenta??o de larvas de pacam?. Os n?uplios de Artemia sp. s?o adequadas para a alimenta??o de larvas de pacam?, sendo recomendado o fornecimento de 70 a 100% do seu peso vivo.The pacam? is a native and endemic species of the basin hydrography basin of the S?o Francisco River. Artemia sp. nauplii constituted an important ingredient especially for fish larvae breeding of marine, and freshwater prawns. Therefore the aim of this study was to evaluate different percentages of Artemia sp.resfriada the power pacam? larvae. Artemia sp. nauplii. are suitable for pacam? larvae feeding, being recommended 70 to 100% of body weight

Microalgae Schizochytrium sp. in diets for Piau juvenilles

Todos os textos, informa??es e resultados apresentados s?o de inteira responsabilidade dos autores.O DHA ? um ?cido importante da s?rie ?mega 3, fundamental para a forma??o do tecido nervoso e visual em humanos, e confere tamb?m uma boa forma??o da massa encef?lica. O presente trabalho teve o objetivo de avaliar dietas contendo a inclus?o da alga Schizochytrium sp. no desempenho produtivo de juvenis de piau.O experimento foi conduzido no Laborat?rio de Aquicultura e Ecologia Aqu?tica do Departamento de Zootecnia da Universidade Federal dos Vales do Jequitinhonha e Mucuri, em Diamantina MG. Foram utilizados 300 juvenis de Piau (Leporinus friderici) com peso e comprimento total m?dio de 11,8 e 9,68 g respectivamente . Os peixes passaram por sete dias de adapta??o e foram alimentados com a ra??o do tratamento controle. . O experimento foi realizado em um delineamento inteiramente casualizado, com cinco tratamentos (0, 10, 20, 30, e 40 g de Schizochytrium sp/kg-1)e quatro repeti??es. Sete juvenis foram estocados por aqu?rio, totalizando 20 parcelas experimentais. Avaliou-se aos 60 dias de experimento par?metros de desempenho produtivo. Foram mensurados: comprimento padr?o (cm), comprimento total (cm), ganho de peso (g), consumo de ra??o (g), convers?o alimentar (g/g)?, biomassa final (g), e sobreviv?ncia (%). As vari?veis de desempenho apresentaram melhores resultados de acordo com o aumento do n?vel de inclus?o da alga Schizochytrium sp em juvenis de piau. Conlcui-se com este estudo que juvenis de piau alimentados com 40g de Schizochytrium sp.kg-1 apresentam melhor desempenho produtivo e sobreviv?ncia.DHA is an important acid of the omega-3 series, essential for the formation of the nervous and visual tissue in humans, and also gives a good formation of brain matter. This study aimed to evaluate diets with the inclusion of algae Schizochytrium sp. In productive performance of piau juveniles.. Experiment was conducted at the Aquaculture Laboratory of Aquatic Ecology of the Department of Animal Science, of the Federal University of the Jequitinhonha and Mucuri Valleys, in Diamantina MG. . Three hundred Piau (Leporinus friderici) juvenile, with body weight and length means of 11.8, and 9.68 g respectively. Fish have undergone seven days of adaptation and were fed with the control ration treatment. The experiment was conducted in a completely randomized design, with five treatments (0, 10, 20, 30, and 40 g of Schizochytrium sp. Kg-1) and four replications. Seven juveniles were stocked per aquarium, totaling 20 experimental plots. It was evaluated at 60 days of the experiment For the productive performance were measured: standard length (cm), total length (cm), weight gain (g), feed intake (g), feed conversion (g / g) ? , final biomass (g) EC (%) and survival (%). The performance variables showed greater results in accordance with the increase in the level of inclusionof Schizochytrium sp in piau juveniles diets. It follows that piau juveniles fed with 40g Schizochytrium sp.kg-1 have greater growth performance and survival

Editing the genome of chicken primordial germ cells to introduce alleles and study gene function

With continuing advances in genome sequencing technology, the chicken genome assembly is now better annotated with improved accuracy to the level of single nucleotide polymorphisms. Additionally, the genomes of other birds such as the duck, turkey and zebra finch have now been sequenced. A great opportunity exists in avian biology to use genome editing technology to introduce small and defined sequence changes to create specific haplotypes in chicken to investigate gene regulatory function, and also perform rapid and seamless transfer of specific alleles between chicken breeds. The methods for performing such precise genome editing are well established for mammalian species but are not readily applicable in birds due to evolutionary differences in reproductive biology. A significant leap forward to address this challenge in avian biology was the development of long-term culture methods for chicken primordial germ cells (PGCs). PGCs present a cell line in which to perform targeted genetic manipulations that will be heritable. Chicken PGCs have been successfully targeted to generate genetically modified chickens. However, genome editing to introduce small and defined sequence changes has not been demonstrated in any avian species. To address this deficit, the application of CRISPR/Cas9 and short oligonucleotide donors in chicken PGCs for performing small and defined sequence changes was investigated in this thesis. Specifically, homology-directed DNA repair (HDR) using oligonucleotide donors along with wild-type CRISPR/Cas9 (SpCas9-WT) or high fidelity CRISPR/Cas9 (SpCas9-HF1) was investigated in cultured chicken PGCs. The results obtained showed that small sequences changes ranging from a single to a few nucleotides could be precisely edited in many loci in chicken PGCs. In comparison to SpCas9-WT, SpCas9-HF1 increased the frequency of biallelic and single allele editing to generate specific homozygous and heterozygous genotypes. This finding demonstrates the utility of high fidelity CRISPR/Cas9 variants for performing sequence editing with high efficiency in PGCs. Since PGCs can be converted into pluripotent stem cells that can potentially differentiate into many cell types from the three germ layers, genome editing of PGCs can, therefore, be used to generate PGC-derived avian cell types with defined genetic alterations to investigate the host-pathogen interactions of infectious avian diseases. To investigate this possibility, the chicken ANP32A gene was investigated as a target for genetic resistance to avian influenza virus in PGC-derived chicken cell lines. Targeted modification of ANP32A was performed to generate clonal lines of genome-edited PGCs. Avian influenza minigenome replication assays were subsequently performed in the ANP32A-mutant PGC-derived cell lines. The results verified that ANP32A function is crucial for the function of both avian virus polymerase and human-adapted virus polymerase in chicken cells. Importantly, an asparagine to isoleucine mutation at position 129 (N129I) in chicken ANP32A failed to support avian influenza polymerase function. This genetic change can be introduced into chickens and validated in virological studies. Importantly, the results of my investigation demonstrate the potential to use genome editing of PGCs as an approach to generate many types of unique cell models for the study of avian biology. Genome editing of PGCs may also be applied to unravel the genes that control the development of the avian germ cell lineage. In the mouse, gene targeting has been extensively applied to generate loss-of-function mouse models to use the reverse genetics approach to identify key genes that regulate the migration of specified PGCs to the genital ridges. Avian PGCs express similar cytokine receptors as their mammalian counterparts. However, the factors guiding the migration of avian PGCs are largely unknown. To address this, CRISPR/Cas9 was used in this thesis to generate clonal lines of chicken PGCs with loss-of-function deletions in the CXCR4 and c-Kit genes which have been implicated in controlling mouse PGC migration. The results showed that CXCR4-deficient PGCs are absent from the gonads whereas c-Kit-deficient PGCs colonise the developing gonads in reduced numbers and are significantly reduced or absent from older stages. This finding shows a conserved role for CXCR4 and c-Kit signalling in chicken PGC development. Importantly, other genes suspected to be involved in controlling the development of avian germ cells can be investigated using this approach to increase our understanding of avian reproductive biology. Finally, the methods developed in this thesis for editing of the chicken genome may be applied in other avian species once culture methods for the PGCs from these species are develope

To play but not for travel: utilitarian, hedonic and non-cyclists in Cagliari, Italy

Active mobility is the most convenient, healthy, environmental friendliness, suitable for short distance mode of transport. The individual and common benefits linked to the active mobility are recognized all over the world and they justify the growing interest in promoting the bike use. In order to suitably promote cycling, it is important to identify the factors that lead to choose the bicycle. This paper, through a factor analysis and a Hybrid Choice Model, analyzes the way in which the bike is perceived by “utilitarian bikers”, “hedonic bikers” and “non-cyclists”. The data used are drawn from a survey conducted by University of Cagliari (Italy) among a sample of 2752 individuals. The findings confirm a significant influence of socio-demographic variables on the propensity to be hedonic, utilitarian or non cyclists and that latent attitudinal variables can discriminate between utilitarian and non cyclists but cann ot discriminate between hedonic and non cyclists

Measurement of non-random attrition effects on mobility rates using trip diaries data

This paper examines the influence of panel attrition on the intrapersonal dynamics in self-reported trip rates, using the data from the 2013, 2014 and 2015 waves of the Netherlands Mobility Panel, a large scale household panel. A hybrid choice model (HCM) was developed to simultaneously model the effect of socioeconomic, infrastructure and land use variables, life events and non-random attrition on trip rates, whereby the latent variable (LV) model is composed of panel attrition and survey completeness. The discrete choice model (DCM) includes four trip rate categories, including zero trips. The probability of each trip rate category was estimated for both the HCM and the DCM models; with and without the LV model. The first main conclusion from this paper is that the largest bias due to panel attrition occurs in the probability of reporting no trips per day, and 1–2 trips per day. Also, the HCM models show a correlation between the probability of reporting no trips per day and the tendency to drop out altogether. The second main conclusion is that the results show that the latent variables (attrition and completeness) are statistically significant in estimating mobility. Also, socioeconomic variables (gender, driving license, household type and size), mode preferences, spatial infrastructure and life events determine mobility rates and remain significant after adding attrition/completeness variables. Thirdly, the results proved that attrition effects significantly vary across waves