Captación artificial y crecimiento temprano de la semilla de Argopecten puppuratus (Lamarck, 1819) en la Reserva Marina La Rinconada, Antofagasta, Chile

Artificial collection of early juveniles (“spat”) of the scallop Argopecten purpuratus in Japanese-type collectors was evaluated between January 2001 and July 2002 in the La Rinconada Marine Reserve, Antofagasta, Chile. This area of Antofagasta Bay has in the past been noted for the retention of scallop larvae by local gyres, in which their numbers can vary between 89 and 34175 larvae m-3, producing larval sets of 400 to 15340 post-larvae (spat) per collector. The results showed no quantitative relationship between larval abundance in the water and the spat density collected per day in the collectors, although high settlement rates were associated with high numbers of umboned larvae in the water. Allowing collectors to remain in situ for extended periods of 88 and 159 days resulted in a severe loss of seed which had settled in the collectors during the first 28 to 40 days of immersion. These losses varied between 50.9 and 99.6% of the spat collected, and were more prejudicial for the smaller cohorts that had settled in the collectors at the end of the first immersion period. The growth rates measured among different cohorts for each immersion period varied between 81.3 and 235.2 mm/day for the first cohort (C1) and between 64.0 and 167.4 mm/day for the second cohort (C2). The highest growth rates occurred in collectors containing the lowest numbers of spat after the occurrence of spat losses during the long periods of immersion. Occurrence of intraspecific competition within the collectors is discussed as potentially responsible for the decreases in spat numbers and the variations observed in their growth rates.Un programa mensual de captación de A. purpuratus, implementado en la reserva marina de La Rinconada, entre enero de 2001 y julio de 2002, la caracterizó como zona de retención larvaria, con densidades variando entre 89 y 34175 larvas m-3, y de fijaciones entre 400 y 15340 post-larvas por colector. No se encontró una relación directa entre abundancia larvaria y asentamiento, sin embargo, las mayores captaciones estuvieron asociadas a la presencia de un elevado número de estados umbonados. La mantenimiento prolongado de colectores in situ, por periodos que variaron entre 88 y 159 días, provocó una fuerte reducción en el número de semillas que se asentaron en ellos durante los primeros 28 a 40 días de inmersión Estas reducciones variaron entre el 99.6 y el 50.9% de la semilla fijada, siendo las más perjudicadas las cohortes más pequeñas, asentadas al final del primer periodo de inmersión. Las tasas de crecimiento registradas en estas cohortes, para cada periodo de inmersión, variaron entre 81.3 y 235.2 ìm/día para las cohortes C1 y entre 64.0 y 167.4 ìm/día para las cohortes C2. Las mayores tasas están directamente relacionadas con un menor número de semilla recuperada. Se discuten las competencias intraespecíficas ocurridas en los colectores, como responsables de la disminución del número de semilla y de las variaciones registradas en sus tasas de crecimiento

Simplified qualitative discrete numerical model to determine cracking pattern in brittle materials by means of finite element method

This paper presents the formulation, implementation, and validation of a simplified qualitative model to determine the crack path of solids considering static loads, infinitesimal strain, and plane stress condition. This model is based on finite element method with a special meshing technique, where nonlinear link elements are included between the faces of the linear triangular elements. The stiffness loss of some link elements represents the crack opening. Three experimental tests of bending beams are simulated, where the cracking pattern calculated with the proposed numerical model is similar to experimental result. The advantages of the proposed model compared to discrete crack approaches with interface elements can be the implementation simplicity, the numerical stability, and the very low computational cost. The simulation with greater values of the initial stiffness of the link elements does not affect the discontinuity path and the stability of the numerical solution. The exploded mesh procedure presented in this model avoids a complex nonlinear analysis and regenerative or adaptive meshes.Peer ReviewedPostprint (published version

Conducta estral circanual en ovejas Pelibuey bajo condiciones áridas del noroeste de México

In order  to determine  the  circannual  estrus  behavior of Pelibuey  ewes  under  arid  conditions of  Northwestern Mexico(32o  NL),  22  adult  ewes  were  maintained  in  confinement  conditions  with  constant  feeding  during  one  year.  Daily,morning  and  afternoon,  the  ewe  group  was  exposed  to  one  of  three  ram  fitted  with  an  apron  to  detect estrusbehavior.  Annual  averages  of  temperature,  relative  humidity  and  temperature-humidity  index  were  25.3±8.1  ºC,33.1±10.7  %  and  72.0±8.4  units,  respectively.  Monthly  percentage  of  ewes  in  estrus  was  lower  (P0.05).  Compared  with  others  months,  a  higher  (P36  and  0.05). Comparado con el resto de los meses; un mayor (P36 y <48h) fue mayor (P<0.05) en junio y agosto. En conclusión, en condiciones áridas del noroeste de México, las ovejas Pelibuey disminuyen su actividad estral de enero a junio, y las elevadas  temperaturas ambientales de verano no son un factor que afecte la presencia de estro en dicha raza

Growth and carcass characteristics of lambs finished with zilpaterol hydrochloride in grazing alfalfa

El objetivo del estudio fue evaluar el efecto de clorhidrato de zilpaterol (CZ) sobre la ganancia de peso y las características de la canal en corderos finalizados en pradera de alfalfa y suplementados con concentrado en corral. Un total de 24 corderos machos enteros Dorper x Pelibuey, con peso vivo inicial de 25.0 ± 0.24 kg, fueron divididos en dos grupos (n=12) y alimentados con 0 o 10 mg/cabeza/día de CZ los últimos 30 días antes del sacrificio. Durante el periodo experimental, todos los corderos pastorearon en alfalfa 8 h/día y se suplementaron con 450 g/d de concentrado. El CZ no afectó (P>0.05) el peso vivo. Las ganancias de peso diaria y total fueron similares (P>0.05) entre ambos grupos. Las características de canal y el rendimiento de cortes primarios no fueron afectados (P>0.05) por el CZ. En conclusión, el clorhidrato de zilpaterol a una dosis de 10 mg/cabeza/día no mejoró el crecimiento ni las características de canal en corderos finalizados en pradera de alfalfa y suplementados con concentrado.The objective of the study was to evaluate the effect of zilpaterol hydrochloride (ZH) on the weight gain and carcass characteristics in lambs finished in alfalfa pasture and supplemented with concentrate in pen. A total of 24 Dorper x Pelibuey ram lambs initially weighting 25.0±0.24 kg were divided in two groups (n=12) and fed with 0 or 10 mg/ head/d of ZH for the last 30 d before slaughter. During the experimental period, all lambs were grazed in alfalfa during 8 h/d and supplemented with 450 g/d of concentrate. The ZH did not affect (P>0.05) the live weight. Daily and total weight gains were similar (P>0.05) between both groups. Carcass characteristics and wholesale cut yields were not affected (P>0.05) by ZH. In conclusion, growth and carcass characteristics were not improved by feeding zilpaterol (10 mg/head/d) in finished lambs on alfalfa grassland and supplemented with concentrate

Effects of zilpaterol hydrochloride and zinc methionine on growth performance and carcass characteristics of beef bulls

Sixty beef bulls with a body weight (BW) of 314.79 16.2 kg were used to evaluate the effects of zilpaterol hydrochloride (ZH) and zinc methionine (ZM) on growth performance and carcass characteristics. The experimental design was a randomized complete block, with a factorial 22 arrangement of treatments (ZH: 0 and 0.15 mg kg 1 BW; ZM: 0 and 80 mg kg 1 dry matter). The ZH increased (PB0.05) the final BW, average daily gain, feed conversion, carcass yield and longissimus dorsi area. Bulls fed ZH plus ZM had less (PB0.01) backfat thickness and intramuscular fat (IMF) compared with those fed ZH or ZM alone. The ZH increased (PB0.02) the meat crude protein content and cooking loss. It is therefore concluded that ZH increases growth performance, carcass yield, longissimus dorsi area, and meat crude protein. The interaction of ZM and ZH did not present additional advantages. The reason for the reduction in backfat thickness and IMF by ZH plus ZM is unclear, and implies that our knowledge of b-agonistic adrenergic substances and their interactions with minerals is incomplete

Un examen actualizado de la percepción de las barreras para la implementación de la farmacogenómica y la utilidad de los pares fármaco/gen en América Latina y el Caribe

La farmacogenómica (PGx) se considera un campo emergente en los países en desarrollo. La investigación sobre PGx en la región de América Latina y el Caribe (ALC) sigue siendo escasa, con información limitada en algunas poblaciones. Por lo tanto, las extrapolaciones son complicadas, especialmente en poblaciones mixtas. En este trabajo, revisamos y analizamos el conocimiento farmacogenómico entre la comunidad científica y clínica de ALC y examinamos las barreras para la aplicación clínica. Realizamos una búsqueda de publicaciones y ensayos clínicos en este campo en todo el mundo y evaluamos la contribución de ALC. A continuación, realizamos una encuesta regional estructurada que evaluó una lista de 14 barreras potenciales para la aplicación clínica de biomarcadores en función de su importancia. Además, se analizó una lista emparejada de 54 genes/fármacos para determinar una asociación entre los biomarcadores y la respuesta a la medicina genómica. Esta encuesta se comparó con una encuesta anterior realizada en 2014 para evaluar el progreso en la región. Los resultados de la búsqueda indicaron que los países de América Latina y el Caribe han contribuido con el 3,44% del total de publicaciones y el 2,45% de los ensayos clínicos relacionados con PGx en todo el mundo hasta el momento. Un total de 106 profesionales de 17 países respondieron a la encuesta. Se identificaron seis grandes grupos de obstáculos. A pesar de los continuos esfuerzos de la región en la última década, la principal barrera para la implementación de PGx en ALC sigue siendo la misma, la "necesidad de directrices, procesos y protocolos para la aplicación clínica de la farmacogenética/farmacogenómica". Las cuestiones de coste-eficacia se consideran factores críticos en la región. Los puntos relacionados con la reticencia de los clínicos son actualmente menos relevantes. Según los resultados de la encuesta, los pares gen/fármaco mejor clasificados (96%-99%) y percibidos como importantes fueron CYP2D6/tamoxifeno, CYP3A5/tacrolimus, CYP2D6/opioides, DPYD/fluoropirimidinas, TMPT/tiopurinas, CYP2D6/antidepresivos tricíclicos, CYP2C19/antidepresivos tricíclicos, NUDT15/tiopurinas, CYP2B6/efavirenz y CYP2C19/clopidogrel. En conclusión, aunque la contribución global de los países de ALC sigue siendo baja en el campo del PGx, se ha observado una mejora relevante en la región. La percepción de la utilidad de las pruebas PGx en la comunidad biomédica ha cambiado drásticamente, aumentando la concienciación entre los médicos, lo que sugiere un futuro prometedor en las aplicaciones clínicas de PGx en ALC.Pharmacogenomics (PGx) is considered an emergent field in developing countries. Research on PGx in the Latin American and the Caribbean (LAC) region remains scarce, with limited information in some populations. Thus, extrapolations are complicated, especially in mixed populations. In this paper, we reviewed and analyzed pharmacogenomic knowledge among the LAC scientific and clinical community and examined barriers to clinical application. We performed a search for publications and clinical trials in the field worldwide and evaluated the contribution of LAC. Next, we conducted a regional structured survey that evaluated a list of 14 potential barriers to the clinical implementation of biomarkers based on their importance. In addition, a paired list of 54 genes/drugs was analyzed to determine an association between biomarkers and response to genomic medicine. This survey was compared to a previous survey performed in 2014 to assess progress in the region. The search results indicated that Latin American and Caribbean countries have contributed 3.44% of the total publications and 2.45% of the PGx-related clinical trials worldwide thus far. A total of 106 professionals from 17 countries answered the survey. Six major groups of barriers were identified. Despite the region’s continuous efforts in the last decade, the primary barrier to PGx implementation in LAC remains the same, the “need for guidelines, processes, and protocols for the clinical application of pharmacogenetics/pharmacogenomics”. Cost-effectiveness issues are considered critical factors in the region. Items related to the reluctance of clinicians are currently less relevant. Based on the survey results, the highest ranked (96%–99%) gene/drug pairs perceived as important were CYP2D6/tamoxifen, CYP3A5/tacrolimus, CYP2D6/opioids, DPYD/fluoropyrimidines, TMPT/thiopurines, CYP2D6/tricyclic antidepressants, CYP2C19/tricyclic antidepressants, NUDT15/thiopurines, CYP2B6/efavirenz, and CYP2C19/clopidogrel. In conclusion, although the global contribution of LAC countries remains low in the PGx field, a relevant improvement has been observed in the region. The perception of the usefulness of PGx tests in biomedical community has drastically changed, raising awareness among physicians, which suggests a promising future in the clinical applications of PGx in LAC

An Updated Examination of the Perception of Barriers for Pharmacogenomics Implementation and the Usefulness of Drug/Gene Pairs in Latin America and the Caribbean

Pharmacogenomics (PGx) is considered an emergent field in developing countries. Research on PGx in the Latin American and the Caribbean (LAC) region remains scarce, with limited information in some populations. Thus, extrapolations are complicated, especially in mixed populations. In this paper, we reviewed and analyzed pharmacogenomic knowledge among the LAC scientific and clinical community and examined barriers to clinical application. We performed a search for publications and clinical trials in the field worldwide and evaluated the contribution of LAC. Next, we conducted a regional structured survey that evaluated a list of 14 potential barriers to the clinical implementation of biomarkers based on their importance. In addition, a paired list of 54 genes/drugs was analyzed to determine an association between biomarkers and response to genomic medicine. This survey was compared to a previous survey performed in 2014 to assess progress in the region. The search results indicated that Latin American and Caribbean countries have contributed 3.44% of the total publications and 2.45% of the PGx-related clinical trials worldwide thus far. A total of 106 professionals from 17 countries answered the survey. Six major groups of barriers were identified. Despite the region’s continuous efforts in the last decade, the primary barrier to PGx implementation in LAC remains the same, the “need for guidelines, processes, and protocols for the clinical application of pharmacogenetics/pharmacogenomics”. Cost-effectiveness issues are considered critical factors in the region. Items related to the reluctance of clinicians are currently less relevant. Based on the survey results, the highest ranked (96%–99%) gene/drug pairs perceived as important were CYP2D6/tamoxifen, CYP3A5/tacrolimus, CYP2D6/opioids, DPYD/fluoropyrimidines, TMPT/thiopurines, CYP2D6/tricyclic antidepressants, CYP2C19/tricyclic antidepressants, NUDT15/thiopurines, CYP2B6/efavirenz, and CYP2C19/clopidogrel. In conclusion, although the global contribution of LAC countries remains low in the PGx field, a relevant improvement has been observed in the region. The perception of the usefulness of PGx tests in biomedical community has drastically changed, raising awareness among physicians, which suggests a promising future in the clinical applications of PGx in LAC

Waveform Modelling for the Laser Interferometer Space Antenna

LISA, the Laser Interferometer Space Antenna, will usher in a new era in gravitational-wave astronomy. As the first anticipated space-based gravitational-wave detector, it will expand our view to the millihertz gravitational-wave sky, where a spectacular variety of interesting new sources abound: from millions of ultra-compact binaries in our Galaxy, to mergers of massive black holes at cosmological distances; from the beginnings of inspirals that will venture into the ground-based detectors' view to the death spiral of compact objects into massive black holes, and many sources in between. Central to realising LISA's discovery potential are waveform models, the theoretical and phenomenological predictions of the pattern of gravitational waves that these sources emit. This white paper is presented on behalf of the Waveform Working Group for the LISA Consortium. It provides a review of the current state of waveform models for LISA sources, and describes the significant challenges that must yet be overcome.Comment: 239 pages, 11 figures, white paper from the LISA Consortium Waveform Working Group, invited for submission to Living Reviews in Relativity, updated with comments from communit

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others