126,861 research outputs found
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
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
Caracterización ultrasonográfica modo-B y Doppler del cuerpo lúteo en llamas
No full textMode B and Doppler ultrasonography in ruminants, as a technique, has allowed establishing new concepts on the reproductive physiology of females, through the study of follicular dynamics and morphometry of the corpus lu-teum, therefore, the objective was to characterize using mode B ultrasound and Doppler the corpus luteum in recipients’ llamas. 37 llamas were used as recipients (27 for mode B and 10 Doppler ultrasound) that were syn-chronized by applying buserelin acetate 0.0096 mg, nine days later 0.048 mg of Prostaglandin F2α analog was applied, two days later the second dose of buserelin acetate in the same dose to a ovulation and subsequent for-mation of the corpus luteum, The B-mode evaluation of the morphometry consisted of observing the ecotexture, area, diameter and volume of the corpus luteum with the use of a SonoStar SS-8® ultrasound machine at 6.5 MHz frequency and 6 cm depth equipped with a transrectal linear transducer, with the same technique with a Draminski 4Vet® Doppler device, the percentage of luteal area of vascularization (% AVL) was determined. The data were subjected to a descriptive analysis, being 0.119±0.032 cm2 in area, 12.7±1.7 mm in diameter and 0.84±0.32 cm3 in volumen of CL, to determine the relationship between metric measurements the Pearson correlation was used observing a positive relationship between area/diameter of 0.6602, observing a high positive correlation between area and volume, finally, the characteristics of % AVL was 34.97 for the CLs of recipients llamas. In conclusion, the morphometric characteristics evaluated in mode B (area, diameter, and volume) have a positive correlation and the % AVL could be applied as a tool in efficient reproduc-tive management for the selection of receptors in camelids, understanding that it is one of the first reports of these characteristics in llamas. 0.7506, area/volume of 0.9289 and diameter/volume of La ultrasonografía modo B y Doppler en los rumiantes, como técnica ha permitido establecer nuevos conceptos sobre la fisiología reproductiva de las hembras, a través del estudio de la dinámica folicular y morfometría del cuerpo lúteo, por tanto, el objetivo fue caracterizar mediante ultrasonografía modo B y Doppler el cuerpo lúteo en llamas receptoras. Se utilizaron 37 llamas como receptoras (27 para ultrasonografía modo B y 10 Doppler) que fueron sincronizadas aplicando acetato de buserelina 0.0096 mg, nueve días posteriores se aplicó 0.048 mg de análogo de prostaglandina F2α, a los dos días posteriores se aplicó la segunda dosis de acetato de buserelina en la misma dosis para garantizar la ovulación y posterior formación del cuerpo lúteo, la evaluación en modo B de la morfometría consistió en observar la ecotextura, área, diámetro y volumen del cuerpo lúteo con el uso de un equipo ultrasonógrafo SonoStar SS-8® a 6.5 MHz de frecuencia y 6 cm de profundidad equipado con un transductor lineal transrectal; con la misma técnica con un equipo Draminski 4Vet® Doppler se determinó el porcentaje de área luteal de vascularización (% AVL). Los datos fueron sometidos a un análisis descriptivo siendo de 0.119±0.032 cm2 de área, 12.7±1.7 mm de diámetro y 0.84±0.32 cm3 de volumen de CL, para determinar la relación entre medidas métricas se utilizó la correlación de Pearson observando una relación positiva entre área/diámetro de 0.7506, área/volumen de 0.9289 y diámetro/volumen de 0.6602, observando una correlación alta positiva entre área y volumen, finalmente las características de % AVL fue de 34.97 para los CL de llamas receptoras. En conclusión, las características morfométricas evaluadas en modo B (área, diámetro y volumen) tienen una correlación positiva y el % AVL podría aplicarse como herramienta en el manejo reproductivo eficiente para la selección de receptoras en camélidos, entendiendo que es uno de los primeros reportes de estas características en llamas
VHH repertoires of naïve and protein-immunized llamas.
No full text<p>VHH sequences from immunized llamas 8 and 9 and seven naïve llamas were amplified from their respective phagemid libraries by PCR using primers specific to the 5′ and 3′ conserved regions of the VHH and subjected to 454 sequencing. (<b>A</b>) Unique sequences generated from the indicated llama phage library were used to build end-joining network diagrams with significantly more linkages (P = 0.001) in the naive llamas versus (<b>B</b>) immunized llamas. (<b>C</b>) Shared percentage identities with neutralizing VHH J3 and divergence from its inferred V gene Vt were calculated for all unique sequences from the control naïve llamas, and the J3-source llama 8. The left hand panel shows percentage identity for all sequences from naïve 3 plotted against divergence from Vt. The right panel shows percentage identity for all sequences from llama 8 plotted against divergence from Vt. The horizontal dotted line on each panel indicates the percentage identity shared by Vt and J3 and the vertical dotted line indicates the divergence of J3 from Vt, (<b>D</b>) Shared percentage identities with neutralizing VHH 3E3 and divergence from its inferred V gene Ve were calculated for all unique sequences from the control naïve llamas, and the 3E3-source llama 9. The left hand panel shows percentage identity for all sequences from naïve 3 plotted against divergence from Ve. The right panel shows percentage identity for all sequences from llama 9 plotted against divergence from Ve. The horizontal dotted line on each panel indicates the percentage identity shared by Ve and 3E3 and the vertical dotted line indicated the divergence of 3E3 from Ve.</p
Pharmacokinetics of ceftiofur in llamas and alpacas
No full textPharmacokinetic studies of antibiotics in South American camelids are uncommon, therefore drugs are often administered to llamas and alpacas based on dosages established in other domestic species. The disposition of ceftiofur sodium was studied in llamas following intramuscular administration and in alpacas following intravenous and intramuscular administration. Eleven adult llamas were given ceftiofur sodium by intramuscular injection. Each animal received either a standard dose of 2.2 mg/kg or an allometrically scaled dose ranging from 2.62 to 2.99 mg/kg in a crossover design. Ten adult alpacas were given ceftiofur sodium by intravenous and intramuscular injections. Each animal received a standard dosage of 1 mg/kg or an allometrically scaled dose ranging from 1.27 to 1.44 mg/kg i.v., and 1.31-1.51 mg/kg i.m. Blood samples were collected at 0, 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, and 72 h after administration of the ceftiofur. Pharmacokinetic parameters of ceftiofur in llamas and alpacas were similar following i.m. dosing at both dose levels. The only differences noted were in the total AUC between dose levels, but the AUC/dose values were not different. A sequence effect was noted in the alpaca data, which resulted in lower AUCs for the second dose when the i.v. dose was given first, and with higher AUCs for the second dose when the i.m. dose was given first. Overall, ceftiofur pharmacokinetics in llamas and alpacas are similar, and also very similar to reported parameters for sheep and goats
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The disposition of four therapeutically important antimicrobial agents in llamas
No full textThe disposition of four therapeutically important antimicrobial agents was studied in llamas following intravenous bolus administration. Six llamas were each given ampicillin, tobramycin, trimethoprim and enrofloxacin at a dose of 12 mg/kg, 1 mg/kg, 3 mg/kg and 5 mg/kg of body weight with a wash out period of 3 days between each treatment. Plasma concentrations of these antimicrobial agents over 12 hours following IV bolus dosing were determined by reverse phase HPLC. Dispositions of these four antimicrobial agents were described by two compartment open model with elimination from the central compartment, and also by non-compartmental methods. From compartmental analysis, the elimination rate constant, half-life, and apparent volume of distribution in the central compartment were determined. Statistical moment theory was used to determine non-compartmental pharmacokinetic parameters of mean residence time, clearance, and volume of distribution at steady-state. Based on the disposition parameters determined, a dose and dosing interval for each of the four antimicrobial agents was suggested for llamas. Steady state peak and trough plasma levels were also predicted for the drugs in this study for llamas
Extended Viral Shedding of MERS-CoV Clade B Virus in Llamas Compared with African Clade C Strain
No full textMiddle East respiratory syndrome coronavirus (MERS-CoV) clade B viruses are found in camelids and humans in the Middle East, but clade C viruses are not. We provide experimental evidence for extended shedding of MERS-CoV clade B viruses in llamas, which might explain why they outcompete clade C strains in the Arabian Peninsula
Education and earnings inequality in Mexico
No full textEducation attainment levels increased dramatically for Mexico's labor force in the 1980s and early 1990s. In parallel, the country experienced a pronounced increase in earnings inequality from 1984-94, reflected in a higher dispersion of wages and an absolute decline in the real incomes of less educated, poorer Mexicans. This increased wage dispersion presents policymakers with a tradeoff between efficiency considerations (favoring increased spending on higher education) and equity considerations (favoring a more equal distribution of per student spending) in the allocation of fiscal resources to education. The author concludes that the best way to deal with this equity-efficiency tradeoff is to encourage greater private participation in higher education. His main findings are that: a) The accumulation of human capital during 1984-94, as proxied by education attainment, was accompanied by a more equal distribution of education attainment levels over that period and, thus, exerted an equalizing effect on the distribution of incomes. The increased income inequalityobserved over that period appears to be caused by an increased rate of skill-based technological change, whose transmission to Mexico and other developing countries may have been facilitated by the increased openness of their economies. b) The greater dispersion of wager observed in Mexico during the past decade raised the rates of return on investing in higher education, reversing the traditional pattern where primary education exhibits the highest rates of return. c) The social rates of return across levels of schooling were more uniform in 1994 than in 1984, suggesting a more efficient assignment of education spending. At the same time, the distribution of spending on education became more egalitarian, as per student spending in higher education declined markedly compared with per student spending at the primary level. This surprising coincidence in the pattern of spending on education was only possible because Mexico started out with a very distorted resource allocation in education that was both highly inequitable and inefficient. As Mexico's policymakers are on the way to correcting these distortions, the opportunities for avoiding the equity-efficiency tradeoff within Mexico's centralized education framework will become progressively exhausted. d) There is little reason to expect the pace of technological change, which appears mainly responsible for raising wage dispersion and the relative returns on higher education, to abate. Efficiency considerations dictate that Mexico should respond by devoting more resources to higher education. However, the federal budget, which traditionally has financed the lion's share of higher education costs in Mexico, is unable to accommodate additional spending on higher education, while spending cuts elsewhere in the education sector are bound to raise serious equity questions. Thus, to avoid falling behind in terms of human capital accumulation, greater private sector participation is necessary, at least, in terms of cost recovery from the main beneficiaries of higher education.Decentralization,Teaching and Learning,Environmental Economics&Policies,Public Health Promotion,Curriculum&Instruction,Teaching and Learning,Environmental Economics&Policies,Health Monitoring&Evaluation,Gender and Education,Curriculum&Instruction
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
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