Chamber specific expression of Myosin heavy chain 7b in the heart of vertebrates

In extant vertebrates, myosin heavy chain (MyHC) 6 and 7 are the main isoforms of atrial and ventricular myocardium respectively, whereas MyHC7b has been proposed to be an ancient cardiac isoform only expressed during embryonic development in modern species. In preliminary immunohistochemical studies of the heart of the lesser spotted dogfish (Scyliorhinus canicula; Chondrichthyes), we have observed that while MF20 labels homogeneously all the myocardium, A4.1025 labels the inflow cardiac segments (sinus venosus and atrium) but not the outflow segments (ventricle and conus arteriosus). In order to interpret these results, we have performed western and slot blots from samples of dogfish and hamster (Mesocricetus auratus) hearts, HPLC-ESI-MS/MS from dogfish samples, and immunohistochemistry in hearts of representative species of vertebrates, namely elasmobranchs, polypteriforms, acipenseriforms, teleosts and mammals, using MF20 and A4.1025 antibodies. Western and slot blot results confirmed the specificity of MF20 and A4.1025 for MyHC in dogfish, as well as their differential reactivity against different myocardial segments. HPLC-ESI-MS/MS using protein databases from Callorhinchus milii (Chondrichthyes) and Chordata revealed the presence of MyHC6 and 7 in all the dogfish myocardial segments, and of MyHC7b only in the outflow segments. Immunohistochemistry showed that while MF20 signals were homogeneous in all the myocardial segments of all the species studied, A4.1025 signals were restricted to the inflow myocardial segments in elasmobranchs, homogeneous in teleosts and acipenseriforms, and low in the ventricle of polypteriforms. It can be inferred that the A4.1025 antibody, as opposed to MF20, has a low affinity for MyHC7b, at least in the dogfish. In addition, we show that MyHC distribution in the cardiac chambers has changed during the evolution of gnathostomes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.Study supported by grants CGL2017-85090-P and CGL2014-52356-P (Ministerio de Economía y Competitividad), FPU15/03209 (Ministerio de Educación, Cultura y Deporte), contract UMAJI75 (Junta de Andalucía, European Social Found), FEDER and Universidad de Málaga

How to avoid a lack of work engagement among public police professionals

This study aims to analyze the combined effect of five conditions—influence at work, interactional justice, workload, laissez-faire leadership, and emotional exhaustion—on the absence of work engagement in public police professionals. Using qualitative comparative analysis on a sample of 119 police professionals, the results show that none of the conditions on their own is necessary to lead to the absence of these professionals' work engagement. In addition, five casual configurations allow for the conclusion that influence at work, interactional justice, emotional exhaustion, and laissez-faire leadership are key conditions, while workload is less decisive in leading to the absence of work engagement in police professionals. The results inform managers of public police institutions on what variables can further contribute to creating workspaces in which learning, professional development, and positive experiences prevail among employees. This study is especially valuable to police professionals because the very nature of their work leads to engagement in acquiring a very powerful meaningS

The Myosin Heavy Chain specific A4.1025 antibody discriminates different cardiac segments in ancient groups of gnathostomes: Morphological and evolutionary implications

El resumen aparece en el Program & Abstracts of the 11th International Congress of Vertebrate Morphology, Washington DC 2016. Anatomical Record, Volume 299, Special Feature: 263.The pan-Myosin Heavy Chain (pan-MyHC) marker MF20 have been reported to show similar, homogeneous signal in the myocardial segments of the heart of teleosts and tetrapods. However, in an ongoing study of the myocardial structure of the dogfish (Scyliorhinus canicula; Chondrichthyes), we observed differential immunostaining of the cardiac segments using another pan-MyHC, the A4.1025 antibody. In order to investigate the relevance of this finding for better understanding of the morphology and evolution of the vertebrate heart, we performed immunohistochemistry, slot blot and western blot in several species of chondrichthyans, actinopterygians and mammals using the above mentioned antibodies. In the dogfish heart, A4.1025 and MF20 specifically recognized MyHC isoforms, although with different degree of affinity. MF20 reactivity was homogeneous and high in all the myocardial segments. However, A4.1025 reactivity was heterogeneous. It was high in the sinus venosus (external layer), atrium and atrioventricular region, low in the ventricle and conus arteriosus, and null in the internal layer of the sinus venosus. A heterogeneous pattern of A4.1025 immunoreactivity was also detected in two other elasmobranchs, a holocephalan, a polypteryform and an acipenseriform. In all of these species, MF20 immunoreactivity was homogeneous. In addition, both markers showed a homogeneous immunoreactivity pattern in teleosts and mammals. Our results indicate that in the hearts of ancient gnathostomes, in all of which a conspicuous conus arteriosus exists, one or more MyHC isoforms with low affinity for A4.1025 show segment-specific distributions. Thus, A4.1025 appears to be an appropriated marker to identify the cardiac segments and their boundaries. We propose that the segmentspecific distribution of MyHC isoforms may generate a particular type of myocardial contractility associated with the presence of a conus arteriosus.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P, CEIMAR, BIO 203, FEDE

Anatomical, histochemical and immunohistochemical characterization of the outflow tract of ray hearts (Rajiformes; Chondrichthyes)

El resumen aparece en el Program & Abstracts of the 11th International Congress of Vertebrate Morphology, Washington DC 2016. Anatomical Record, Volume 299, Special Feature: 264.Recent work has shown that the cardiac outflow tract of sharks and chimaeras does not consist of a single myocardial component, the conus arteriosus, as classically accepted, but two, namely, the myocardial conus arteriosus and the non-myocardial bulbus arteriosus. However, the anatomical composition of the outflow tract of the batoid hearts remains unknown. The present study was designed to fill this gap. The material examined consisted of hearts of two species of rays, namely, the Mediterranean starry ray (Raja asterias) and sandy ray (Leucoraja circularis). They were studied using scanning electron microscopy, and histochemical and inmunohistochemical techniques. In both species, the outflow tract consists of two components, proximal and distal with regard to the ventricle. The proximal component is the conus arteriosus; it is characterized by the presence of compact myocardium in its wall and several transverse rows of pocket-shaped valves at its luminal side. Each valve consists of a leaflet and its supporting sinus. Histologically, the leaflet has two fibrosas, inner and outer, and a middle coat, the spongiosa. The distal component lacks myocardium. Its wall consists of smooth muscle cells, elastic fibers and collagen. Thus, it shows an arterial-like structure. However, it differs from the aorta because it is covered by the epicardium and crossed by coronary arteries. These findings indicate that the distal component is morphologically equivalent to the bulbus arteriosus of sharks and chimaeras. In contrast to foregoing descriptions, the valves of the first transverse row are distally anchored to the bulbus arteriosus and not to the ventral aorta. Our findings give added support to the notion that presence of a bulbus arteriosus at the arterial pole of the heart is common to all chondrichtyans, and not an apomorphy of actinopterygians as classically thought.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P, CEIMAR, BIO 203, FEDE

¿De dónde vienes, corazón? ¿Existe un origen evolutivo del miocardio compacto y su vascularización común para todos los Vertebrados?

De dónde vienes, corazón? ¿Existe un origen evolutivo del miocardio compacto y su vascularización común para todos los Vertebrados? López-Unzu MA, Lorenzale M, Soto-Navarrete MT. Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga (Málaga) Hay preguntas que son comunes a cualquier rama del conocimiento que trate conceptos evolutivos. Una de las más frecuentes, sobre todo en el campo de la Biología Evolutiva, tiene que ver con la procedencia de los caracteres que comparten diferentes grupos de organismos. ¿Tienen esos caracteres un mismo origen evolutivo? El corazón de los condrictios y el de los mamíferos difieren anatómicamente. El corazón de los mamíferos se compone de cuatro cámaras (dos aurículas y dos ventrículos) que conectan con un sistema circulatorio doble. En cambio, el de los condrictios consta de seis segmentos (seno venoso, atrio, región atrio-ventricular, ventrículo, cono arterioso y bulbo arterioso) y bombea la sangre a través de un sistema circulatorio sencillo. La disposición estructural del músculo cardiaco también es diferente en los condrictios y los mamíferos. En los mamíferos el miocardio es de tipo compacto y está irrigado por arterias coronarias. En los condrictios el tipo de miocardio y su vascularización muestran una variación que abarca desde un miocardio de tipo mixto, compuesto por una capa compacta, externa, y otra trabeculada o esponjosa, interna, irrigado por arterias coronarias, hasta un miocardio trabeculado, que puede presentar coronarias o ser avascular. Con estos datos expuestos, se han planteado las cuestiones siguientes. En los primeros vertebrados, ¿qué tipo de miocardio existió?, ¿tenían corazones avasculares o irrigados por arterias coronaria? ¿Tiene la vascularización cardiaca de los vertebrados un origen común o ha aparecido más de una vez? Para indagar acerca de estas cuestiones, se han abordado un estudio que incluye un análisis histomorfológico comparado del miocardio en corazones adultos de diferentes especies de vertebrados, un estudio descriptivo del desarrollo del miocardio y su vascularización en una especie representativa de los condrictios y, por último, la detección diferencial de proteínas cardiacas mediante técnicas en biología molecular y su localización aplicando técnicas inmunohistoquímicas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P (Ministerio de Economía y Competitividad, Madrid, España), FEDER y FPU15/03209 (Ministerio de Educación, Cultura y Deporte, Madrid, España)

¿Qué hay de pez en tu corazón? Los puntos clave de la evolución cardíaca.

Los peces son un grupo diverso de organismos acuáticos -compuesto por condrictios y osteictios- que disponen de un sistema circulatorio cerrado simple, a diferencia del resto de vertebrados, los tetrápodos, que poseen un sistema circulatorio cerrado doble. Ambos grupos tienen un órgano que actúa como bomba de propulsión, el corazón. Anatómicamente, el corazón de los peces, se diferencia al de tetrápodos por ser tubular y estar constituido por seis segmentos, que en sentido caudo-cefálico son: seno venoso, atrio, región atrioventricular, ventrículo, cono arterioso y bulbo arterioso, por los que la sangre circula en un solo sentido. La longitud relativa del bulbo y el cono arterioso varía entre los diferentes grupos de peces. En algunos tetrápodos, como los mamíferos, el corazón es tetracamerado y consta de dos aurículas y dos ventrículos comunicados mediante regiones atrioventriculares. En la pared de todos los segmentos miocárdicos, tanto de peces como de tetrápodos se diferencian tres capas, que de la más externa a la más interna son: epicardio, miocardio y endocardio. El bulbo arterioso no es miocárdico y su pared se compone por epicardio, una capa media formada por musculatura lisa, elastina y colágeno, y endocardio. En peces, el miocardio tiene una morfología variable (mixta o esponjosa), mientras que en tetrápodos solo es compacta. Durante las primeras etapas (estadios) del desarrollo cardiaco de tetrápodos, el corazón, tiene una morfología tubular similar al de los peces. En estadios posteriores, tiene lugar un evento de torsión que, como consecuencia, cambia la posición caudal de la región de entrada de sangre a una posición cefálica. Esta nueva distribución junto a la compartimentación del corazón en cuatro cámaras, es lo que permite el establecimiento de una circulación doble. Con el fin de aumentar el conocimiento existente, nos disponemos a describir y comparar corazones de peces y tetrápodos adultos, así como su desarrollo. Una incursión desde la óptica de la ciencia básica para conocer mejor un órgano con gran interés médico. El trabajo ha sido parcialmente financiado por el proyecto CGL2014-52356-PUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto CGL2014-52356-

Influence of Ionophore Supplementation on Growth Performance, Dietary Energetics and Carcass Characteristics in Finishing Cattle during Period of Heat Stress.

Forty-eight crossbred heifers (378.1±18 kg) were used in a 56-d feeding trial (four pens per treatment in a randomised complete block design) to evaluate the influence of ionophore supplementation on growth performance, dietary energetics and carcass characteristics in finishing cattle during a period of heat stress. Heifers were fed a diet based on steam-flaked corn (2.22 Mcal NEm/kg) with and without an ionophore. Treatments were: i) control, no ionophore; ii) 30 mg/kg monensin sodium (RUM30); iii) 20 mg/kg lasalocid sodium (BOV20), and iv) 30 mg/kg lasalocid sodium (BOV30). Both dry matter intake (DMI) and climatic variables were measured daily and the temperature humidity index (THI) was estimated. The maximum THI during the study averaged 93, while the minimum was 70 (THI average = 79.2±2.3). Compared to controls, monensin supplementation did not influence average daily gain, the estimated NE value of the diet, or observed-to-expected DMI, but tended (p = 0.07) to increase (4.8%) gain to feed. Compared to controls, the group fed BOV30 increased (p≤0.03) daily gain (11.8%), gain to feed (8.3%), net energy of the diet (5%), and observed-to-expected DMI (5.2%). Daily weight gain was greater (7.6%, p = 0.05) for heifers fed BOV30 than for heifers fed MON30. Otherwise, differences between the two treatments in DMI, gain to feed, and dietary NE were not statistically significant (p>0.11). Plotting weekly intakes versus THI, observed intake of controls was greater (p<0.05) at THI values ≤77 than ionophore groups. When THI values were greater than 79, DMI of control and MON30 were not different (p = 0.42), although less than that of groups fed lasalocid (p = 0.04). Variation in energy intake was lower (p>0.05) in the ionophores group (CV = 1.7%) than in the control group (CV = 4.5%). Inclusion of ionophores in the diet resulted in relatively minor changes in carcass characteristics. It is concluded that ionophore supplementation did not exacerbate the decline of DM intake in heat-stressed cattle fed a high-energy finishing diet; on the contrary, it stabilised feed intake and favoured feed efficiency. Ionophore supplementation reduced estimated maintenance coefficients around 10% in finishing cattle during a period of heat stress. This effect was greatest for heifers supplemented with 30 mg lasalocid/kg of diet

Importancia del concepto de Empresa Familiar en investigación: utilización de la base de datos SABI para su clasificación

Este trabajo tiene que ver con aspectos conceptuales de la empresa familiar (EF) y su impacto en la investigación. Su objetivo es servir de guía en el desarrollo de trabajos empíricos que pretenden disociar la EF de la empresa no familiar (EnF) mediante la utilización de bases de datos, particularmente contables y, más concretamente, en el caso español, con la base SABI. En él se pone de manifiesto la importancia, en el ámbito empírico, de buscar un mecanismo que nos permita identificar la EF de forma eficiente, así como las dificultades existentes para ello con el uso de SABI. Trabajar con diferentes criterios de selección y el uso de apellidos nos permite proponer una tipología de EF.

Effects of Replacing Dry-rolled Corn with Increasing Levels of Corn Dried Distillers Grains with Solubles on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy of Diet in Hair Lambs Fed High-concentrate Diets.

Four male lambs (Katahdin; average live weight 25.9±2.9 kg) with "T" type cannulas in the rumen and proximal duodenum were used in a 4×4 Latin square experiment to evaluate the influence of supplemental dry distillers grain with solubles (DDGS) levels (0, 10, 20 and 30%, dry matter basis) in substitution for dry-rolled (DR) corn on characteristics of digestive function and digestible energy (DE) of diet. Treatments did not influence ruminal pH. Substitution of DR corn with DDGS increased ruminal neutral detergent fiber (NDF) digestion (quadratic effect, p<0.01), but decreased ruminal organic matter (OM) digestion (linear effect, p<0.01). Replacing corn with DDGS increased (linear, p≤0.02) duodenal flow of lipids, NDF and feed N. But there were no treatment effects on flow to the small intestine of microbial nitrogen (MN) or microbial N efficiency. The estimated UIP value of DDGS was 44%. Postruminal digestion of OM, starch, lipids and nitrogen (N) were not affected by treatments. Total tract digestion of N increased (linear, p = 0.04) as the DDGS level increased, but DDGS substitution tended to decrease total tract digestion of OM (p = 0.06) and digestion of gross energy (p = 0.08). However, it did not affect the dietary digestible energy (DE, MJ/kg), reflecting the greater gross energy content of DDGS versus DR corn in the replacements. The comparative DE value of DDGS may be considered similar to the DE value of the DR corn it replaced up to 30% in the finishing diets fed to lambs

Effects of Combining Feed Grade Urea and a Slow-release Urea Product on Performance, Dietary Energetics and Carcass Characteristics of Feedlot Lambs Fed Finishing Diets with Different Starch to Acid Detergent Fiber Ratios.

Recent findings have shown that microbial nitrogen flow and digestible energy of diets are increased when urea is combined with a slow-release urea (SRU) in diets with a starch to acid detergent fibre ratio (S:F) 4:1. This affect is attributable to enhanced synchrony between ruminal N availability for microbial growth and carbohydrate degradation. To verify the magnitude of this effects on lamb performance, an experiment was conducted to evaluate the effects of combining urea and a SRU in diets containing S:F ratios of 3:1, 4:1, or 5:1 on performance, dietary energetics and carcass characteristics of finishing lambs. For that, 40 Pelibuey×Katahdin lambs (36.65±3 kg) were assigned to one of five weight groupings in 20 pens (5 repetition/treatments). The S:F ratio in the diet was manipulated by partially replacing the corn grain and dried distiller's grain with solubles by forage (wheat straw) and soybean meal to reach S:F ratios of 3:1, 4:1 or 5:1. An additional treatment of 4:1 S:F ratio with 0.8% urea as the sole source of non-protein nitrogen was used as a reference for comparing the effect of urea combination vs. conventional urea at the same S:F ratio. There were no treatment effects on dry matter intake (DMI). Compared the urea combination vs urea at the same S:F ratio, urea combination increased (p<0.01) average daily gain (ADG, 18.3%), gain for feed (G:F, 9.5%), and apparent energy retention per unit DMI (8.2%). Irrespective of the S:F ratio, the urea combination improved the observed-to-expected dietary ratio and apparent retention per unit DMI was maximal (quadratic effect, p≤0.03) at an S:F ratio of 4:1, while the conventional urea treatment did not modify the observed-to-expected net energy ratio nor the apparent retention per unit DMI at 4:1 S:F ratio. Urea combination group tended (3.8%, p = 0.08) to have heavier carcasses with no effects on the rest of carcass characteristics. As S:F ratio increased, ADG, G:F, dietary net energy, carcass weight, dressing percentage and longissimus thoracis (LM) area increased linearly (p≤0.02). Combining urea and a slow-release urea product results in positive effects on growth performance and dietary energetics, but the best responses are apparently observed when there is a certain proportion (S:F ratio = 4:1) of starch to acid detergent fibre in the diet