Performance evaluation of two slow-medium growing chicken strains maintained under organic production system during different seasons

A total of 160 1-day-old medium-growing male chicks (Gallus gallus domesticus) were raised for 120 days in a certified organic farming system. A total of two strains were studied (Coloryield, CY; RedBro, RB). Overall, two weather periods were considered based on the outdoor temperature, being S1 colder than S2. In total, 40 chicks per strain were assigned to each period (n = 80). Chickens were fed ad libitum with the same organic feeds. In the first month, chickens were kept indoors and, from day 30, they had access to the pasture. Slaughter live weight (LW), average daily gains, (ADG), the feed conversion ratio (FCR), and mortality rates did not differ between the two strains. LW was (p < 0.05) higher in the S1 and a trend (p = 0.084) was observed for ADG, which was higher in S1. No differences were found for feed intake, FCR, and mortality rates between weather periods. There were no differences for coefficient of variation (CV) between the strains studied, nevertheless, CV for LW in S2 was increased. Differences in the productive performance between these strains raised in organic production systems were slight. However, chickens raised in S1 had a better performance. It would be preferable to raise chickens in these weather conditions whenever possible. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Diversidad de mariposas (Lepidoptera, Papilionoidea) y su relación con el paisaje de alta montaña en los Andes nororientales de Colombia

Diversitat de papallones (Lepidoptera, Papilionoidea) i la seva relació amb el paisatge d’alta muntanya als Andes nord-orientals de Colòmbia La regió andina es caracteritza per acollir una gran varietat d’ecosistemes entre els quals es compten les característiques zones d’alta muntanya, que mostren processos de transformació del sòl accelerats que han convertit els boscos natius en zones agrícoles i ramaderes, la qual cosa ha ocasionant un declivi de la diversitat biològica regional. L’ús d’indicadors de diversitat és adequat per avaluar els canvis en els paisatges d’alta muntanya i les papallones són un dels grups més importants per determinar els canvis que es produeixen en els diferents tipus d’ambients. A l’àrea d’estudi es van establir dotze punts de mostreig als complexos d’erms d’Almorzadero, Santurbán i Tamá de la regió nord-oriental de Colòmbia. Durant la fase de mostreig es van practicar captures d’individus adults de papallones en transsectes de 100 x 4 m en un gradient altitudinal de 500 m. Es van registrar 69 espècies, pertanyents a cinc famílies. Els valors de diversitat de la comunitat de papallones diürnes van variar a les diferents cobertures vegetals associades a cada transsecte. Així, les àrees amb cobertura vegetal conservada (per exemple, bosc dens, arbustos i matolls i erm i suberm) van presentar els valors més alts de diversitat, mentre que les zones amb cobertura alterada (per exemple, bosc fragmentat, pastures i àrees agrícoles) van presentar els valors de diversitat més baixos. Les anàlisis d’estructura de comunitats evidencien que les espècies de papallones endèmiques estan associades a àrees fragmentades a les zones d’alta muntanya. Aquest estudi és el primer del seu tipus que estableix canvis en la diversitat de les papallones en zones d’alta muntanya del nord-est de Colòmbia i s’ha fet amb el propòsit de generar estratègies de conservació en llocs que presenten un alt grau d’endemisme i diversitat.Diversity of butterflies (Lepidoptera, Papilionoidea) and their relationship with the highlands’ landscape in the northeastern Andes of Colombia The Andean region harbors a great variety of ecosystems, including the characteristic high mountain zones. The biological diversity in these zones, however, is declining as the result of changes in land use, particularly the introduction of agriculture and cattle ranching. Changes in the high mountain landscape can be appropriately monitored using diversity indicators such as butterflies, one of the most important indicator species. We chose twelve sampling points in the paramo (high altitude moor) complexes Almorzadero, Santurbán and El Tamá, located in the northeastern region of Colombia to collect adult butterflies within transects of 100 x 4 m, along an altitudinal gradient of 500 m. We recorded 69 species, from five families. Diversity values of the diurnal butterfly communities varied among  the different areas of vegetation coverage associated with each transect. Conserved vegetation coverage (i.e. dense forest, scrublands and scrublands, and paramo and subparamo) showed the highest values of diversity, while  perturbed coverage (i.e. fragmented forests, pastures and agriculture areas) presented the lowest values of diversity. Analysis of the community structure showed that endemic butterfly species were associated with fragmented areas in the high mountains. Findings from this study, the first of its kind to determine changes in butterfly diversity in highlands in northeastern Colombia, may help to generate conservation strategies in places where there is high endemism and diversityLa región andina se caracteriza por albergar una gran variedad de ecosistemas entre los que se cuentan las características zonas de alta montaña, que muestran acelerados procesos de transformación del suelo que han convertido los bosques nativos en zonas agrícolas y ganaderas ocasionando un declive de la diversidad biológica regional. El empleo de indicadores de diversidad es adecuado para evaluar los cambios en los paisajes de alta montaña, siendo las mariposas uno de los grupos más importantes para determinar los cambios que se producen en los diferentes tipos de ambientes. En el área de estudio se establecieron doce puntos de muestreo en los complejos de páramos del Almorzadero, Santurbán y Tamá de la región nororiental de Colombia. Durante la fase de muestreo se realizaron capturas de individuos adultos de mariposas en transectos de 100 x 4 m en un gradiente altitudinal de 500 m. Se registraron 69 especies, pertenecientes a cinco familias. Los valores de diversidad de la comunidad de mariposas diurnas variaron en las diferentes coberturas vegetales asociadas a cada transecto. Así, las áreas con cobertura vegetal conservada (por ejemplo, bosque denso, arbustos y matorrales y páramo y subpáramo) presentaron los valores más altos de diversidad, mientras que las zonas con cobertura alterada (por ejemplo, bosque fragmentado, pastos y áreas agrícolas) presentaron los valores de diversidad más bajos. Los análisis de estructura de comunidades evidencian que las especies de mariposas endémicas están asociadas a áreas fragmentadas en las zonas de alta montaña. Este estudio es el primero de su tipo que establece cambios en la diversidad de las mariposas en zonas de alta montaña del nordeste de Colombia y se ha realizado con el propósito de generar estrategias de conservación en lugares que presentan un alto grado de endemismo y diversidad

Irreversible and reversible modes of operation of deterministic ratchets

We discuss a problem of optimization of the energetic efficiency of a simple rocked ratchet. We concentrate on a low-temperature case in which the particle's motion in a ratchet potential is deterministic. We show that the energetic efficiency of a ratchet working adiabatically is bounded from above by a value depending on the form of ratchet potential. The ratchets with strongly asymmetric potentials can achieve ideal efficiency of unity without approaching reversibility. On the other hand we show that for any form of the ratchet potential a set of time-protocols of the outer force exist under which the operation is reversible and the ideal value of efficiency is also achieved. The mode of operation of the ratchet is still quasistatic but not adiabatic. The high values of efficiency can be preserved even under elevated temperatures

Ordovician and Silurian geological heritage of the Arouca region (Portugal)

4 páginas, 3 figuras.-- Trabajo presentado en la 44ª Sesión Científica, Jaén, 2008.The studied region is situated in the Aveiro district, about 50 km SW of Oporto (northern Portugal) and has a rich geological, biological and cultural heritage. The Arouca Geopark was formally established there in late 2007, under the auspices of Arouca’s Municipal Chamber, to reunite 36 geosites from which some of them involve remarkable Ordovician and Silurian rocks and fossils. Outcrops of both periods belong to the Valongo- Tamames syncline of the Central Iberian Zone. Lower Palaeozoic rocks around the Canelas Slate Quarry are of special interest, leading to the creation of a geotouristic route visiting three Ordovician units (Santa Justa quartzites, Valongo shales and Sobrido quartzite plus glaciomarine diamictites) and one Silurian (graptolitic black shales), as well as a Roman gold mine dug in the Lower Ordovician quartzites. However, the most outstanding geosite is the quarry itself, where Middle Ordovician giant trilobites (up to 70 cm in size) and trilobite clusters (up to thousands of specimens) occur in large slabs of slate and are recovered during the exploitation. The Geological Interpretation Centre of Canelas, located near the quarry and open since 2006, is one of the main tourist attractions of the Arouca Geopark, created to preserve and disseminate knowledge about trilobites and the Ordovician world, and having received more than 10,000 visitors in its first 17 months.La empresa Ardósias Valério & Figueiredo Lda., por su apoyo continuado al trabajo paleontológico en la cantera de Canelas. A la Câmara Municipal de Arouca, por su sensibilidad en la gestión del patrimonio geológico y la financiación (a D.R.) para su inventario. Este trabajo es una contribución a los proyectos CGL2006-07628/BTE y PTDC/CTE-GEX/64966/2006, financiados por el Ministerio de Educación y Ciencia español y la Fundación de Ciencia y Tecnología de Portugal, respectivamente.Peer reviewe

The burden of mild cognitive impairment attributable to physical inactivity in Colombia

BACKGROUND: Mild cognitive impairment often precedes dementia. The purpose of this analysis was to estimate the population attributable fraction for physical activity in Colombia, which is the reduction in cases that would occur if all participants were physically active. METHODS: The sample included 20,174 men and women aged 70.04 +/- 7.68 years (mean +/- SD) from the National Survey of Health, Wellbeing and Ageing. Trained interviewers administered a shorter version of the mini-mental state examination and mild cognitive impairment was defined as a score of 12 or less out of 19. Logistic regression models were fitted and population attributable fractions for physical activity were calculated. All analyses were adjusted for age, sex, height, education, income, civil status, smoking, and alcohol drinking. RESULTS: The prevalence of physical activity was approximately 50% when defined as walking between 9 and 20 blocks at least three times per week. Theoretically, 19% of cases of mild cognitive impairment would be eliminated if all adults were to walk (95% confidence interval: 16%, 22%). The prevalence was approximately 20% when defined as taking part in vigorous sport or exercise at least three times per week. Theoretically, 23% of cases of mild cognitive impairment would be eliminated if all adults were to take part in vigorous sport or exercise (16%, 30%). Similar results were observed after removing those who reported mental health problems. CONCLUSION: Physical activity, whether walking or vigorous sport and exercise, has the potential to substantially reduce the burden of mild cognitive impairment in Colombia

Socio-economic and Technical Characteristics of Backyard Animal Husbandry in Two Rural Communities of Yucatan, Mexico

This research work was conducted in order to asses the socio-economic and technical aspects of backyard animal rearing in two communities of Yucatán, México. One hundred and thirty nine families were interviewed in Sudzal (C1) and 117 families in San Jose Tzal (C2). A structured questionnaire was used to interview the families on technical and socio-economic aspects. Using this information the technical level of animal husbandry and a index of socio-economic status of the families involved in backyard animal rearing in both communities were determined. In C1 46.8% of the interviewed families reared animals in their backyard in comparison to 70.9% in C2. Main animal species kept in the backyard were chickens (C1= 92.3% and C2= 88.0), turkeys (C1= 63.1% and C2= 55.4%) and pigs (C1= 38.5% and 1C2= 5. 7% in C1 and C2 respectively). In C2 100% of pigs kept in the backyard were of the commercial type. Technical level in animal production was significantly higher (P 0.0001) in C2 than in C1, because utilisation of commercial diets was higher in C2 (P 0.001) than in C1. The families of C2 had a higher socio-economic level (P 0.002) than families from C1, because families of C2 have houses built with lasting materials (P 0.0001) and the occupation of the head of the family was associated with higher income (merchants or employees) (P 0.0001). The correlation coefficients between socio-economic status and technical level in backyard animal production showed that 84% of the technical level was explained by the socio-economic status. It can be concluded that socio-economic status has a high influence on backyard animal production characteristics. The socio-economic status determine the number of animals kept and the technical level in animal rearing

State-of-the-art of spatial arch bridges

The paper describes a new form of bridge called a spatial arch bridge. This bridge type was developed in response to the demand for landmark structures, which have started to appear in the modern urban landscape to provide a symbol of originality, innovation and progress. Spatial arch bridges are defined as bridges in which the vertical deck loads produce bending moments and shear forces not contained in the arch plane, owing to their geometrical and structural configuration. Moreover, the arch itself may not be contained in a plane. The different variables and geometries that create such a structural configuration have been studied and classified. A wide compilation of examples of this bridge type has been made in chronological order, according to their construction date, from Maillarts first concrete spatial arch bridges to the latest designs and materials

Las sucesiones estratigráficas del Paleozoico inferior y medio

13 páginas, 20 páginas.-- Editor: García Cortés, Angel.-- Capítulo 2.Peer reviewe

Plate fixation or intramedullary fixation of humeral shaft fractures: An updated meta-analysis

Background The optimal approach to operative treatment of humeral shaft fractures remains debatable. Previously published trials have been limited in size and have been inconclusive regarding important patient outcome variables following treatment with either intramedullary nails or plates. We conducted a meta-analysis of available trials comparing treatment of humeral shaft fractures

Phytochemical composition and antioxidant capacity of the aqueous extracts of Malva sylvestris L. and Malva pseudolavatera Webb & Berthel.

Context: Malva spp. have been widely used in the world as traditional remedies. In Ecuadorian markers Malva sylvestris and Malva pseudolavatera are the species most commercialized. However, the scientific information about M. pseudolavatera is little. Aims: To determine the chemical composition and antioxidant capacity of the aqueous extracts of the leaves of both species. Methods: Aqueous extracts were partitioned with butanol and the fractions obtained were analyzed by GC/MS. Total extracts were evaluated as antioxidants using FRAP, DPPH and ABTS assays. Results: Differences in the chemical composition were found between the extracts. Both extracts showed the presence of polysaccharides, phenolic acids and fatty acids, but in M. sylvestris were identified polyols, which there was not observed in M. pseudolavatera. The aqueous extracts showed free radical scavenging and ferric reducing power capacities in vitro assays, being M. sylvestris the most promissory antioxidant, possibly due to the presence of polyols in the extract. In the present research were reported 39 phytochemical compounds by first time for the specie M. pseudolavatera. Conclusions: Aqueous extracts of the leaves of M. sylvestris and M. pseudolavatera showed antioxidant capacity associated with the presence of phenolic acids, polysaccharides and flavonoids in the extracts. Keywords: antioxidant; gas chromatography; Malva pseudolavatera; Malva sylvestris; phytochemicals