196,069 research outputs found
Automatic System for Wind Turbine Testing
No full textAn innovative electronic system for testing the performance of wind turbines is presented. The main goal of the system is to increase the accuracy in the measurements of torque and speed for each steady-state point of the turbine characteristic power curve. Another useful advantage provided by the electronic control is given by the possibility of fine tuning the load in order to obtain a large number of steady state experimental points describing the characteristic curve of the turbine. Moreover, the system is suitable for integration into an automatic data acquisition and control system. In the paper the main characteristics of the electronic system are described and compared with a traditional system. This electronic control system is used for testing a small Vertical Axis Wind Turbine in a wind tunnel. The wind turbine is directly coupled to a direct current electric generator, and a chopper, electronically controlled by means of a Pulse Width Modulator, is used to supply the circuit. The electric generator is used for braking the wind turbine at various speeds during the performance test. The experimental results obtained through the proposed system are presented and discussed.</jats:p
MC1R gene: comparison between different farm animal species
No full textIl gene MC1R: confronto fra diverse specie animali di interesse zootecnico. Negli animali di interesse zootecnico, il polimorfismo del gene MC1R coinvolto nella pigmentazione è stato studiato a livello molecolare soltanto nell’ultimo decennio. Si sono confrontate descrizioni fenotipiche e polimorfismi del gene MC1R in alcune razze bovine (Rendena, Bruna, Cabannina, Ottonese-Varzese e Pezzata Rossa) e nel cavallo (62 animali). Tutti gli animali feomelanici sono portatori delle mutazioni recessive allo stato omozigote indipendentemente dalla tonalità del mantello. I cavalli neri sono portatori dell’allele selvatico del gene MC1R e della mutazione recessiva del gene ASIP allo stato omozigote. Nei cavalli bai e nelle altre razze bovine studiate è presente, almeno allo stato eterozigote, l’allele selvatico. Nella Bruna e nella Cabannina è presente anche l’allele E1. Nel gene MC1R, sequenziato in capre di razza Bionda dell’Adamello e Nera di Verzasca, si è evidenziata l’unica mutazione descritta in letteratura. I risultati sono stati confrontati con le informazioni disponibili nella specie murina e umana.Coat colour genes in farm animals have only been studied at molecular level over the last ten years, starting with Klungland et al. in 1995. Among the genes involved in pigmentation, MC1R, previously known as Extension locus, revealed polymorphisms related to red and black coat colour in different farm animal species. More exactly, the MelanoCortin-1 Receptor (MC1R) gene, specifically expressed in melanocytes, encodes for the homonymous G-protein coupled receptor involved in the regulation of the type of melanin synthesized. Melanocytes produce in fact two different types of melanins: the black or brown eumelanin and the yellow or red pheomelanin. The hair distribution of eu- and pheomelanins depends on the activity of MC1R, which is normally modulated by response to the melanocortin hormone, antagonized by the action of Agouti protein encoded by the ASIP gene. We previously studied the MC1R polymorphisms in some cattle reared in Italy (Crepaldi et al., 2003) and we now present the data on MC1R in other Italian cattle breeds, horses and goats. The aim of this work is to compare the pigmentary phenotypes and causative MC1R mutations in different farm animals and model species, such as mouse and human, in order to highlight differences and similarities between phenotypes and MC1R polymorphisms. The relationship between phenotypes and Agouti locus is also discussed
Study on genetic variability at alfa s1 and alfa s2 casein loci in autochthonous goat populations of the Lombardy Alps
No full textComparison of coat color description and polymorphisms of MC1R, ASIP and TYRP1 genes in horses
No full textPreliminary study on MC1R polymorphism in some cattle breeds raised in Italy
No full textRicerche preliminari sul polimorfismo del gene MC1R in alcune razze bovine allevate in Italia – Il gene MC1R è stato analizzato in 193 soggetti appartenenti a 8 razze bovine, tramite PCR, per la presenza di due mutazioni ad effetto fenotipico noto sulla pigmentazione del mantello: la delezione G310 e la sostituzione T296C, associate rispettivamente al fenotipo feomelanico (e) ed eumelanico nero (Ed). Sessanta soggetti di razza Limousine e Pezzata Rossa Italiana presentano genotipo e/e; 27 soggetti di razza Frisona Italiana mostrano genotipo Ed/Ed mentre 2 genotipo Ed/e. Gli 84 soggetti appartenenti alle razze Cabannina, Chianina, Marchigiana e Piemontese non presentano tali mutazioni, analogamente a 18 soggetti di razza Romagnola, nella quale però si sono anche osservati 2 soggetti portatori dell’allele e allo stato eterozigote
SP10 The MC1R gene polymorphism in some cattle breeds raised in Italy
No full textMost of the standardized cattle breeds raised in Italy have a coat colour that often allows their unique identification. Thus, the study of polymorphisms in genes involved in pigmentation could provide genetic markers useful for their identification. We have studied the polymorphism of MC1R gene in 213 animals from 9 cattle breeds raised in Italy: Limousin (37), Cabannina (20), Chianina (20), Grey Alpine (20), Italian Holstein (29), Italian Red Spotted (23), Marchigiana (20), Piedmontese (24) and Romagnola (20). Two PCR-RFLP protocols were used to detect the G310 deletion (e allele) and the T296C substitution (Ed allele) respectively causative of a nonfunctional receptor and a constitutively expressed receptor. All Limousin and Italian Red Pied animals resulted homozygous for the e allele. In the Italian Holstein (black pied), 27 out of 29 animals were homozygous for the Ed allele, while 2 were heterozygous Ede. Cabannina, Chianina, Marchigiana, Piedmontese and Romagnola have the same pigmentation pattern, pheomelanic with eumelanic extremities. In the former four breeds all animals investigated resulted homozygous for the wild-type allele (E+E+). Conversely, in the Romagnola breed 2 animals were heterozygous for the e allele (E+e). In the Alpine Grey these two mutations were also not observed. These results suggest that MC1R alleles may be helpful in tracing the origin of food products from Italian cattle. In fact Italian Holstein meat and milk can be revealed by the Ed allele; meat from Chianina, Marchigiana, and Piedmontese breeds can be distinguished by those from Holstein, Limousin or Italian Red Spotted by the absence of both Ed and e mutations. MC1R polymorphisms alone are insufficient to univocally identify single breeds, however the parallel investigation of a number of coat colour genes may reveal the existence of breed-specific genomic formulas permitting a precise molecular tracing of animal products
On the Role of Low-Mass Asymptotic Giant Branch Stars in Producing a Solar System Distribution of s-Process Isotopes
No full textThe production of s-isotopes due to the operation of the reaction 13C(α, n)16O in low-mass stars during asymptotic giant branch phases is investigated following in detail the time evolution of the thermal pulses, the temperature and density stratification within the convective shells, and taking into account the effect of the neutron recycling by 12C through the chain 12C(n, γ)13C(α, n)16O. The resulting average neutron density reaches a maximum of about 5×109cm-3 and then decreases smoothly. Strong overabundances for all s-isotopes with A > 80 are obtained in a solar system distribution. The process appears suitable to reproduce many observed details concerning isotopic ratios
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
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