152,708 research outputs found
Diversidad genética y estructura de población de cabras autóctonas nigerianas usando marcadores microsatélites DNA
No full textTwenty-nine microsatellite markers were used to evaluate genetic diversity and rela-tionships among three Nigerian goat breeds and to compare with one South African and one European goat breeds as outgroups. A total of 244 goats from the Sahel (47), Maradi (47), and West African Dwarf (67) breeds; and as outgroup: Kalahari (47) and Saanen (36) breeds were included. DNA was extracted from blood preserved on FTA Classic cards according to manufacturer’s protocol. The microsatellite regions were amplified using thermal cycler. Mean number of allele (MNA), expected and observed Heterozygousities (He and Ho, respectively), Hardy-Weinberg Equilibrium (HWE) and genetic distances between populations were calculated. A dendogram was constructed to reveal evolutionary trend in the studied breeds. A genetic structure of the populations was performed using STRUCTURE. Genetic diversity was high with MNA per locus ranging from 6.69 to 8.79 for Kalahari and West African Dwarf, respectively. Ho values ranged from 59 % for West African Dwarf to 64.9 % for Saanen. The highest He estimates were observed in the West African Dwarf (70 %). The lowest He (66.5 %) was observed in Saanen population. The Mean Fis values for the studied populations ranged from 0.055 to 0.148 for Kalahari and West Africa Dwarf, respectively. Genetic distances between populations revealed the least genetic relationship between Saanen and Maradi (0.386) and highest between Maradi and Sahel (0.025). The HWE test revealed eighteen, seventeen, thirteen, twenty-three, and twenty-one loci were in HWE (p>0.05) in Maradi, West African Dwarf, Sahel, Saanen, and Kalahari, respectively. A gra-phic representation of the STRUCTURE analysis revealed that Nigerian goats descended from a common ancestor different from South African and European breeds used as outgroups
Electronic and phonon contributions to the Thermoelectric properties of newly discovered half-Heusler alloys XHfPb (X= Ni, Pd, and Pt)
No full textIn this work we calculate the thermoelectric figure of merit of XHfPb (X= Ni, Pd, and Pt) by computing the both the power factor and the lattice thermal conductivity by first principles. We make reasonable approximations: we use the Constant Relaxation Time Approximation (CRTA) to compute the electron transport contribution and the modified Debye-Callaway model to calculate the thermal lattice conductivity. We also report the dielectric properties of these semiconductors and the mode Gruneisen parameters. Not surprisingly we find that the average Gruneisen coefficient correlates with the thermal conductivity. Next, we consider a realistic relaxation timer-and carrier concentration n from experimental data on ZrHfPb and obtain the figure of merit ZT as a function of temperature. Our main finding is that despite the Pt is isoelectronic with Ni and Pd, the ZT of PtHfPb is larger and behaves differently from the other two materials, suggesting that PtHfPb is better suited for high temperature thermoelectric generators
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Characterization of the structural response of a lithiated SiO<sub>2</sub> / Si interface: A reactive molecular dynamics study
No full textWe report the results of a computational study regarding the mechanical properties of a lithiated Si/SiO2 interface using reactive molecular dynamics. The study is motivated by an intended application of SiO2-coated Sinanotubes as fibers in structural batteries with a fiber-reinforced composite architecture while serving as anodes. According to the results, main failure properties due to partly irreversible bond breakage during mechanical deformation are identified, indicating agreement with bond energy/bond order based estimates. Microscopic failure properties are also identified and interpreted in view of the observed processes of bonding degradation. In particular, the effect of Li distribution on the shear deformation response is evaluated as significant.Applied Mechanic
Larry O. Spencer, Conference Author Presentation
No full textGen. Larry O. Spencer, USAF (Ret.), author of Dark Horse: A Journey from the Horseshoe to the Pentago
Detecting the existence of gene flow between Spanish and North African goats through a coalescent approach
No full textHuman-driven migrations are one of the main processes shaping the genetic diversity and population structure of domestic species. However, their magnitude and direction have been rarely analysed in a statistical framework. We aimed to estimate the impact of migration on the population structure of Spanish and African goats. To achieve this goal, we analysed a dataset of 1,472 individuals typed with 23 microsatellites. Population structure of African and Spanish goats was moderate (mean F ST = 0.07), with the exception of the Canarian and South African breeds that displayed a significant differentiation when compared to goats from North Africa and Nigeria. Measurement of gene flow with Migrate-n and IMa coalescent genealogy samplers supported the existence of a bidirectional gene flow between African and Spanish goats. Moreover, IMa estimates of the effective number of migrants were remarkably lower than those calculated with Migrate-n and classical approaches. Such discrepancies suggest that recent divergence, rather than extensive gene flow, is the main cause of the weak population structure observed in caprine breeds
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
O. A. C. Review Volume XXXVI Issue 12, August 1924
No full textThis slim summer issue contains the address given by the agricultural section of the British Association for the Advancement of Science, and a report on the visit of this association to the O. A. C. Other articles include instructions on increasing strawberry production and a biography of the author John Masefield. The editorial comments on Rhodes Scholars. The Alumni column provides an update of alumni activities. This issue does not contain a Macdonald column.JoyPresent-day problems in crop productionAfter the strawberry harvestJohn MasefieldVisit of the Agricultural Section of the British Association for the Advancement of ScienceEditorialCollege lifeAlumniadvertisin
An empirical study on the influence of sustainable environmental manufacturing practice on firm performance
No full textEnvironmental problem has been linked to the operational activities of manufacturing
firms as they yield production with economic values under the guidance of environmental regulation.
Hence, sustainable environmental practice is one of the critical factors in the competition and
performance among manufacturers. This study investigates the influence of sustainable environmental
manufacturing practices (SEMP) on firm performance. A survey questionnaire was used to collect
data from 103 manufacturing companies in Malaysia and it was analysed with SmartPLS. The
result found a significant relationship between SEMP and environmental performance, but could
not find an evidence of a significant relationship between SEMP, and financial and operational
performance. This implies that SEMP is yet to be considered as a strategic resource in achieving
competitive advantage and better firm performance among manufacturing companies. Therefore,
the study suggests that the environmental policy maker should create more awareness to enlighten
the manufacturing practitioners not only to perceive sustainable environmental practices as ethical
but also as a strategic factor in achieving better firm performance.
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