Estudio Comparativo de los Efectos del Tipo de Forraje y de la Proporción Forraje - Concentrado sobre la Fermentación Ruminal en Cabras y en Fermentadores de Flujo Simple Continuo.

Los fermentadores de flujo continuo (FFC) permiten el estudio de la fermentación ruminal de forma más simple y menos costosa que los ensayos in vivo. Sin embargo, las comparaciones directas rumen – FFC son escasas y las existentes se han llevado a cabo con fermentadores de flujo doble continuo y ganado vacuno (Hannah et al., 1986; Mansfield et al., 1995; Muetzel et al., 2008). La información relativa a pequeños rumiantes es escasa (Carro et al., 2009; Molina et al., 2009) y los diferentes estudios han empleado ingestas variables entre 10,5 (Muetzel et al., 2008) y 90 (Slyter y Rumsey, 1991) g de materia seca (MS)/día/L de volumen efectivo del fermentador. Dado el efecto del pH sobre la fermentación ruminal (Calsamiglia et al., 2008) su estudio parece esencial en lo que a la simulación in vitro se refiere. El objetivo del presente trabajo es comparar los efectos del tipo de forraje (F) y de la relación forraje:concentrado (F:C) sobre la fermentación ruminal en el rumen de caprino y en fermentadores de flujo simple continuo (FFSC). Además, se analiza el efecto del pH utilizando suministrando a los FFSC 30 ó 45 g MS/día

The effect of sheep genetic merit and feed allowance on nitrogen partitioning and isotopic discrimination

Animal nitrogen (N) partitioning is a key parameter for profitability and sustainability of ruminant production systems, which may be predicted from N isotopic discrimination or fractionation (Δ¹⁵N). Both animal genetics and feeding level may interact and impact on N partitioning. Therefore, this study aimed to assess the interactive effects of genetic merit (G) and feed allowance (F) on N partitioning and Δ¹⁵N in sheep. The sheep were drawn from two levels of G (high G vs. low G; based on New Zealand Sheep Improvement Limited (http://www.sil.co.nz/) dual (wool and meat) growth index) and allocated to two levels of F (1.7 (high F) vs. 1.1 (low F) times Metabolisable Energy requirement for maintenance) treatments. Twenty-four Coopworth rams were divided into four equal groups for a N balance study: high G × high F, high G × low F, low G × high F, and low G × low F. The main factors (G and F) and the interaction term were used for 2-way ANOVA and regression analysis. Higher F led to higher N excretions (urinary N (UN); faecal N (FN); manure N), retained N, N use efficiency (NUE), and urinary purine derivatives excretion (P < 0.05). On the other hand, higher UN/N intake, and plasma Δ¹⁵N were observed with the lower F (P < 0.05). Higher G led to increased UN, FN, manure N, apparent N digestibility, and urinary purine derivatives excretion (P < 0.05). Higher F only increased UN in high G sheep, with no effect on low G sheep (P < 0.05). Regression analysis results demonstrated potential to use plasma Δ¹⁵N to reflect the effects of G and F on NUE and UN/N intake. Further research is urged to study interactive effects of genetic and feeding level on sheep N partitioning

Micro and nano-patterning of single-crystal diamond by swift heavy ion irradiation

This paper presents experimental data and analysis of the structural damage caused by swift-heavy ion irradiation of single-crystal diamond. The patterned buried structural damage is shown to generate, via swelling, a mirror- pattern on the sample surface, which remains largely damage-free. While extensive results are available for light ion implantations, this effect is reported here for the first time in the heavy ion regime,where a completely different range of input parameters (in terms of ion species, energy, stopping power, etc.) is available for customized irradiation. The chosen ion species are Au and Br, in the energy range 10–40 MeV. The observed patterns, as characterized by profilometry and atomic force microscopy, are reported in a series ofmodel experiments,which show swelling patterns ranging from a few nm to above 200 nm. Moreover, a systematic phenomenological modeling is presented, inwhich surface swelling measurements are correlated to buried crystal damage. A comparison ismade with data for light ion implantations, showing good compatibilitywith the proposedmodels. The modeling presented in thiswork can be useful for the design and realization of micropatterned surfaces in single crystal diamond, allowing generating highly customized structures by combining appropriately chosen irradiation parameters and masks

Review: Biological determinants of between-animal variation in feed efficiency of growing beef cattle

Animal's feed efficiency in growing cattle (i.e. the animal ability to reach a market or adult BW with the least amount of feed intake), is a key factor in the beef cattle industry. Feeding systems have made huge progress to understand dietary factors influencing the average animal feed efficiency. However, there exists a considerable amount of animal-to-animal variation around the average feed efficiency observed in beef cattle reared in similar conditions, which is still far from being understood. This review aims to identify biological determinants and molecular pathways involved in the between-animal variation in feed efficiency with particular reference to growing beef cattle phenotyped for residual feed intake (RFI). Moreover, the review attempts to distinguish true potential determinants from those revealed through simple associations or indirectly linked to RFI through their association with feed intake. Most representative and studied biological processes which seem to be connected to feed efficiency were reviewed, such as feeding behaviour, digestion and methane production, rumen microbiome structure and functioning, energy metabolism at the whole body and cellular levels, protein turnover, hormone regulation and body composition. In addition, an overall molecular network analysis was conducted for unravelling networks and their linked functions involved in between-animal variation in feed efficiency. The results from this review suggest that feeding and digestive-related mechanisms could be associated with RFI mainly because they co-vary with feed intake. Although much more research is warranted, especially with high-forage diets, the role of feeding and digestive related mechanisms as true determinants of animal variability in feed efficiency could be minor. Concerning the metabolic-related mechanisms, despite the scarcity of studies using reference methods it seems that feed efficient animals have a significantly lower energy metabolic rate independent of the associated intake reduction. This lower heat production in feed efficient animals may result from a decreased protein turnover and a higher efficiency of ATP production in mitochondria, both mechanisms also identified in the molecular network analysis. In contrast, hormones and body composition could not be conclusively related to animal-to-animal variation in feed efficiency. The analysis of potential biological networks underlying RFI variations highlighted other significant pathways such as lipid metabolism and immunity and stress response. Finally, emerging knowledge suggests that metabolic functions underlying genetic variation in feed efficiency could be associated with other important traits in animal production. This emphasizes the relevance of understanding the biological basis of relevant animal traits to better define future balanced breeding programmes

Fat accretion measurements strengthen the relationship between feed conversion efficiency and Nitrogen isotopic discrimination while rumen microbial genes contribute little

The use of biomarkers for feed conversion efficiency (FCE), such as Nitrogen isotopic discrimination (ΔN), facilitates easier measurement and may be useful in breeding strategies. However, we need to better understand the relationship between FCE and ΔN, particularly the effects of differences in the composition of liveweight gain and rumen N metabolism. Alongside measurements of FCE and ΔN, we estimated changes in body composition and used dietary treatments with and without nitrates, and rumen metagenomics to explore these effects. Nitrate fed steers had reduced FCE and higher ΔN in plasma compared to steers offered non-nitrate containing diets. The negative relationship between FCE and ΔN was strengthened with the inclusion of fat depth change at the 3lumbar vertebrae, but not with average daily gain. We identified 1,700 microbial genes with a relative abundance >0.01% of which, 26 were associated with ΔN. These genes explained 69% of variation in ΔN and showed clustering in two distinct functional networks. However, there was no clear relationship between their relative abundances and ΔN, suggesting that rumen microbial genes contribute little to ΔN. Conversely, we show that changes in the composition of gain (fat accretion) provide additional strength to the relationship between FCE and ΔN

Children at danger: injury fatalities among children in San Diego County

External causes of death are important in the pediatric population worldwide. We performed an analysis of all injury-fatalities in children between ages zero and 17 years, between January 2000 and December 2006, in San Diego County, California, United States of America. Information was obtained from the County of San Diego Medical Examiner’s database. External causes were selected and grouped by intent and mechanism. Demographics, location of death and relation between the injury mechanism and time of death were described. There were 884 medico-legal examinations, of which 480 deaths were due to external causes. There majority were males (328, 68.3%) and whites (190, 39.6%). The most prevalent mechanism of injury leading to death was road traffic accidents (40.2%), followed by asphyxia (22.7%) and penetrating trauma (17.7%). Unintentional injuries occurred in 65.8% and intentional injuries, including homicide and suicide, occurred in 24.2 and 9.4%, respectively. Death occurred at the scene in 196 cases (40.9%). Most deaths occurred in highways (35.3%) and at home (28%). One hundred forty-six patients (30.4%) died in the first 24 h. Seven percent died 1 week after the initial injury. Among the cases that died at the scene, 48.3% were motor vehicle accidents, 20.9% were victims of firearms, 6.5% died from poisoning, 5% from hanging, and 4% from drowning. External causes remain an important cause of death in children in San Diego County. Specific strategies to decrease road-traffic accidents and homicides must be developed and implemented to reduce the burden of injury-related deaths in children

The gap in injury mortality rates between urban and rural residents of Hubei province, China

<p>Abstract</p> <p>Background</p> <p>Injury is a growing public health concern in China. Injury death rates are often higher in rural areas than in urban areas in general. The objective of this study is to compare the injury mortality rates in urban and rural residents in Hubei Province in central China by age, sex and mechanism of injury.</p> <p>Methods</p> <p>Using data from the Disease Surveillance Points (DSP) system maintained by the Hubei Province Centers for Disease Control and Prevention (CDC) from 2006 to 2008, injury deaths were classified according to the International Classification of Disease-10^thRevision (ICD-10). Crude and age-adjusted annual mortality rates were calculated for rural and urban residents of Hubei Province.</p> <p>Results</p> <p>The crude and age-adjusted injury death rates were significantly higher for rural residents than for urban residents (crude rate ratio 1.9, 95% confidence interval 1.8-2.0; adjusted rate ratio 2.4, 95% confidence interval 2.3-2.4). The age-adjusted injury death rate for males was 81.6/100,000 in rural areas compared with 37.0/100 000 in urban areas; for females, the respective rates were 57.9/100,000 and 22.4/100 000. Death rates for suicide (32.4 per 100 000 vs 3.9 per 100 000), traffic-related injuries (15.8 per 100 000 vs 9.5 per 100 000), drowning (6.9 per 100 000 vs 2.3 per 100 000) and crushing injuries (2.0 per 100 000 vs 0.7 per 100 000) were significantly higher in rural areas. Overall injury death rates were much higher in persons over 65 years, with significantly higher rates in rural residents compared with urban residents for suicide (279.8 per 100 000 vs 10.7 per 100 000), traffic-related injuries, and drownings in this age group. Death rates for falls, poisoning, and suffocation were similar in the two geographic groups.</p> <p>Conclusions</p> <p>Rates of suicide, traffic-related injury deaths and drownings are demonstrably higher in rural compared with urban locations and should be targeted for injury prevention activity. There is a need for injury prevention policies targeted at elderly residents, especially with regard to suicide prevention in rural areas in Central China.</p

The value of postmortem computed tomography as an alternative for autopsy in trauma victims: a systematic review

The aim of this study was to assess the role of postmortem computed tomography (PMCT) as an alternative for autopsy in determining the cause of death and the identification of specific injuries in trauma victims. A systematic review was performed by searching the EMBASE and MEDLINE databases. Articles were eligible if they reported both PMCT as well as autopsy findings and included more than one trauma victim. Two reviewers independently assessed the eligibility and quality of the articles. The outcomes were described in terms of the percentage agreement on causes of death and amount of injuries detected. The data extraction and analysis were performed together. Fifteen studies were included describing 244 victims. The median sample size was 13 (range 5–52). The percentage agreement on the cause of death between PMCT and autopsy varied between 46 and 100%. The overall amount of injuries detected on CT ranged from 53 to 100% compared with autopsy. Several studies suggested that PMCT was capable of identifying injuries not detected during normal autopsy. This systematic review provides inconsistent evidence as to whether PMCT is a reliable alternative for autopsy in trauma victims. PMCT has promising features in postmortem examination suggesting PMCT is a good alternative for a refused autopsy or a good adjunct to autopsy because it detects extra injuries overseen during autopsies. To examine the value of PMCT in trauma victims there is a need for well-designed and larger prospective studies

International study to evaluate PCR methods for detection of Trypanosoma cruzi DNA in blood samples from Chagas disease patients

A century after its discovery, Chagas disease, caused by the parasite Trypanosoma cruzi, still represents a major neglected tropical threat. Accurate diagnostics tools as well as surrogate markers of parasitological response to treatment are research priorities in the field. The polymerase chain reaction (PCR) has been proposed as a sensitive laboratory tool for detection of T. cruzi infection and monitoring of parasitological treatment outcome. However, high variation in accuracy and lack of international quality controls has precluded reliable applications in the clinical practice and comparisons of data among cohorts and geographical regions. In an effort towards harmonization of PCR strategies, 26 expert laboratories from 16 countries evaluated their current PCR procedures against sets of control samples, composed by serial dilutions of T.cruzi DNA from culture stocks belonging to different lineages, human blood spiked with parasite cells and blood samples from Chagas disease patients. A high variability in sensitivities and specificities was found among the 48 reported PCR tests. Out of them, four tests with best performance were selected and further evaluated. This study represents a crucial first step towards device of a standardized operative procedure for T. cruzi PCR.Fil: Schijman, Alejandro G. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratorio de Biología Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Bisio, Margarita. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratorio de Biología Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Orellana, Liliana. Universidad de Buenos Aires. Instituto de Cálculo; Argentina.Fil: Sued, Mariela. Universidad de Buenos Aires. Instituto de Cálculo; Argentina.Fil: Duffy, Tomás. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratorio de Biología Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Mejia Jaramillo, Ana M. Universidad de Antioquia. Grupo Chagas; Colombia.Fil: Cura, Carolina. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratorio de Biología Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Auter, Frederic. French Blood Services; Francia.Fil: Veron, Vincent. Universidad de Parasitología. Laboratorio Hospitalario; Guayana Francesa.Fil: Qvarnstrom, Yvonne. Centers for Disease Control. Department of Parasitic Diseases; Estados Unidos.Fil: Deborggraeve, Stijn. Institute of Tropical Medicine; Bélgica.Fil: Hijar, Gisely. Instituto Nacional de Salud; Perú.Fil: Zulantay, Inés. Facultad de Medicina; Chile.Fil: Lucero, Raúl Horacio. Universidad Nacional del Nordeste; Argentina.Fil: Velázquez, Elsa. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología Dr. Mario Fatala Chaben; Argentina.Fil: Tellez, Tatiana. Universidad Mayor de San Simon. Centro Universitario de Medicina Tropical; Bolivia.Fil: Sanchez Leon, Zunilda. Universidad Nacional de Asunción. Instituto de Investigaciones en Ciencias de la Salud; Paraguay.Fil: Galvão, Lucia. Faculdade de Farmácia; Brasil.Fil: Nolder, Debbie. Hospital for Tropical Diseases. London School of Tropical Medicine and Hygiene Department of Clinical Parasitology; Reino Unido.Fil: Monje Rumi, María. Universidad Nacional de Salta. Laboratorio de Patología Experimental; Argentina.Fil: Levi, José E. Hospital Sirio Libanês. Blood Bank; Brasil.Fil: Ramirez, Juan D. Universidad de los Andes. Centro de Investigaciones en Microbiología y Parasitología Tropical; Colombia.Fil: Zorrilla, Pilar. Instituto Pasteur; Uruguay.Fil: Flores, María. Instituto de Salud Carlos III. Centro de Mahahonda; España.Fil: Jercic, Maria I. Instituto Nacional De Salud. Sección Parasitología; Chile.Fil: Crisante, Gladys. Universidad de los Andes. Centro de Investigaciones Parasitológicas J.F. Torrealba; Venezuela.Fil: Añez, Néstor. Universidad de los Andes. Centro de Investigaciones Parasitológicas J.F. Torrealba; Venezuela.Fil: De Castro, Ana M. Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública (IPTSP); Brasil.Fil: Gonzalez, Clara I. Universidad Industrial de Santander. Grupo de Inmunología y Epidemiología Molecular (GIEM); Colombia.Fil: Acosta Viana, Karla. Universidad Autónoma de Yucatán. Departamento de Biomedicina de Enfermedades Infecciosas y Parasitarias Laboratorio de Biología Celular; México.Fil: Yachelini, Pedro. Universidad Católica de Santiago del Estero. Instituto de Biomedicina; Argentina.Fil: Torrico, Faustino. Universidad Mayor de San Simon. Centro Universitario de Medicina Tropical; Bolivia.Fil: Robello, Carlos. Instituto Pasteur; Uruguay.Fil: Diosque, Patricio. Universidad Nacional de Salta. Laboratorio de Patología Experimental; Argentina.Fil: Triana Chavez, Omar. Universidad de Antioquia. Grupo Chagas; Colombia.Fil: Aznar, Christine. Universidad de Parasitología. Laboratorio Hospitalario; Guayana Francesa.Fil: Russomando, Graciela. Universidad Nacional de Asunción. Instituto de Investigaciones en Ciencias de la Salud; Paraguay.Fil: Büscher, Philippe. Institute of Tropical Medicine; Bélgica.Fil: Assal, Azzedine. French Blood Services; Francia.Fil: Guhl, Felipe. Universidad de los Andes. Centro de Investigaciones en Microbiología y Parasitología Tropical; Colombia.Fil: Sosa Estani, Sergio. ANLIS Dr.C.G.Malbrán. Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias; Argentina.Fil: DaSilva, Alexandre. Centers for Disease Control. Department of Parasitic Diseases; Estados Unidos.Fil: Britto, Constança. Instituto Oswaldo Cruz/FIOCRUZ. Laboratório de Biologia Molecular e Doenças Endêmicas; Brasil.Fil: Luquetti, Alejandro. Laboratório de Pesquisa de Doença de Chagas; Brasil.Fil: Ladzins, Janis. World Health Organization (WHO). Special Programme for Research and Training in Tropical Diseases (TDR); Suiza