Indicadores de receptividad ovina en tres áreas ecológicas de la provincia de Santa Cruz

Tesis para obtener el grado de Magíster Scientiae, de la Universidad Nacional de Mar del Plata, en 2010En Patagonia Sur los cálculos de receptividad ganadera se basan en la estimación de la oferta forrajera de gramíneas bajas. Sin embargo, los arbustos y subarbustos representan hasta el 75% de la PPNA en algunas de las áreas ecológicas de la región, y algunas de sus especies tienen altos valores de proteína. El objetivo de este estudio fue evaluar los siguientes indicadores de la receptividad ganadera ovina en tres áreas ecológicas de la provincia de Santa Cruz y explorar su variabilidad: 1- acumulación de forraje, 2- cobertura de estratos (arbustos, subarbustos, coironal e intercoironal) y especies, y 3- uso de estratos y especies por ovinos. Las áreas ecológicas consideradas fueron Meseta Central (MC), Golfo San Jorge (GSJ) y Matorral de Mata Negra (MMN). En cada área se seleccionó un establecimiento representativo y en cada uno de ellos se escogieron al azar 3 cuadros y se establecieron 3 sitios por cuadro. En enero de 2008 en cada sitio se estimó para cada estrato y especie: su disponibilidad en la vegetación (por cosecha en una clausura), su cobertura (por 100 determinaciones puntuales sobre una transecta de 200 m) y además su porcentaje en las dietas de los ovinos (por microhistología de heces). Además, se estimó el valor nutritivo (%DMS y %PB) del intercoironal y de las especies más abundantes en las dietas y se calcularon índices de selectividad (IS) por estratos y especies, utilizando dos estimadores de su abundancia en la vegetación: cobertura y disponibilidad. Finalmente, con los porcentajes en las dietas y los datos de valor nutritivo estimados, se calculó el aporte de PB que realizan al forraje consumido el intercoironal y las especies individuales. La variabilidad de los datos entre áreas y sitios se exploró por ACP, y las diferencias entre áreas se analizaron por ANVA. En promedio la biomasa total acumulada fue un 83% mayor en MC que en las otras dos áreas (MC=268±40a, GSJ=149±42b y MMN=144±19b MS:kg*ha-1). El intercoironal representó el 16 17 y el 61% para MC, GSJ y MMN, respectivamente, y los estratos leñosos en conjunto el 65, 54 y 20%. La cobertura vegetal fue un 15% superior en MC que en las otras dos áreas (MC=61,0, GSJ=55,3 MMN=52,7). La mayor cobertura de arbustos se registró en el área de MMN (24%), en MC y GSJ la cobertura de este estrato fue de 9 y 4%, respectivamente. Las dietas estuvieron integradas principalmente por especies del intercoironal (MC=68, GSJ=59 y MMN=82%) y los estratos leñosos representaron el 31, 37 y 8%, para las mismas áreas, respectivamente. Sólo 6 ítems estuvieron presentes en más del 10% en las dietas promedio (MC=4, GSJ=3 y MMN=4) y en conjunto representaron el 70, 54 y 74% del total. Según el área ecológica, entre el 68 y 86% de la proteína total de las dietas fue aportado por el intercoironal y en MC y GSJ el 17 y 20% por Chuquiraga sp, el único ítem del componente subarbustivo que estuvo presente en porcentajes mayores al 16% en las dietas y cuyas flores tienen 6% de proteína. En las tres áreas el intercoironal fue siempre seleccionado y el coironal y subarbustos evitados. El patrón de selección de arbustos fue más complejo. En GSJ fueron seleccionados en función de su cobertura pero evitados en función de su disponibilidad y en MMN ocurrió lo inverso. Los resultados indican la capacidad de los ovinos de adaptarse a cambios en la estructura y variaciones de la vegetación, ya que independientemente de la composición botánica del pastizal y de la abundancia relativa de cada estrato, tienden a conformar dietas semejantes entre áreas, y obtienen siempre un forraje de mayor calidad que la media que ofrece el ambiente.In South Patagonia, sheep carrying capacity estimations are carried out considering the short grasses availability but not that of woody species. However, in some ecological areas, shrubs and dwarf shrubs represent up to 75% of the ANPP, and some of their species have high protein values. The objective of this study was to evaluate the following indicators of carrying capacity in three ecological areas of the province of Santa Cruz, exploring their variability: 1- Forage availability, 2- Vegetation cover by strata (shrubs, dwarf shrubs, tussocks and short grasses), and 3- Sheep utilization of strata and species. The ecological areas considered were: Central Plateau Dwarf Shrubland (CP); San Jorge Gulf High Shrubland (SJG) and Mata Negra (Junellia tridens) High Shrubland (MNM). In each area, a representative farm was selected, three paddocks were randomly chosen, and three sites were defined. In January 2008 forage availability (from harvest inside an exclosure), and strata and species cover (100 points on a 200 m transect) and use by sheep (by feces microhistological analysis) were estimated at each site. In addition, the nutritive value (%DMS and %PB) of the short grass strata, and that of the more abundant species in the diets were determined. Also, selection indices (SI) for strata and the more abundant species in the diets were calculated using cover and forage availability vegetation data. Finally, the percentages of protein in diets were calculated using the percentages in diets of the short grass strata and those of the individual species and their nutritive values. Variability between areas and sites was explored by PCA and analyzed by ANOVA. Total biomass accumulation was a 83% higher in CP than in the other two areas (CP=268±40a, SJG=149±42b y MNM=144±19b DM kg*ha-1). Short grasses accounted for 16, 17 and 61% and the woody strata 65, 55 and 20% in CP, SJG and MNM, respectively. Vegetation cover was 15% higher in CP than in the other two areas (CP=61, SJG=55 and MNM=53%). Woody strata cover was higher in MNM (24%), whereas CP and SJG showed 9 and 4% in, respectively. Diets were mainly composed by short grasses species (CP=68, SJG=59 and MNM=82%) and the woody strata represented the 31, 37 and 8% in those areas. Only 6 item accounted more than 10% in the diets (CP=4, SJG=3 and MNM=4) and together represented 70, 54 and 74% of their botanical composition. According ecological area, 68 and 86% of total protein in the diets was provided by short grasses, and 17 to 20% by Chuquiraga sp, the only dwarf shrub item found in percentages higher than 16% in the diets, whose flowers contain 6% PB. Selection indices estimated using vegetation cover showed that short grasses were selected in the three areas (SI: CP=0.3, SJG=0.2 and MNM=0.3) and shrubs only in SJG (SI=0.5). Dwarf shrub were consumed proportionally to their cover, selected in CP and SJG (SI=0) and avoided in MNM (SI=-0.4). These results indicate that sheep have the ability to adapt to changes in structure and composition of vegetation, and that independently of the botanical composition of the vegetation and the relative abundances of the strata, they tend to select similar diets, obtaining a higher quality forage than would be expected the average offer.EEA Santa CruzFil: Andrade, Miguel Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentin

Chequeo de pastizales del campo Experimental Potrok Aike año 2015 y análisis comparativo del periodo 2010 – 2015

En Santa Cruz la ganadería ovina extensiva se basa en el aprovechamiento de la productividad primaria de los pastizales naturales, la cual depende entre otras cosas, de las precipitaciones ocurridas durante el año. Para realizar un manejo adecuado de estos sistemas, una de las premisas indica que se debe ajustar la carga animal en función de la receptividad de los campos (Cingolani et al., 2008).EEA Santa CruzFil: Vargas, Paola Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Andrade, Miguel Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentin

COMPARAÇÃO DE PROCESSOS E TIPOS DE 2ª GERAÇÃO DE BIOCOMBUSTÍVEIS: UMA AVALIAÇÃO DO POTENCIAL BRASILEIRO E PORTUGUÊS

Diante da relevância da exploração de recurso renovaveis no cenário mundial, este artigo analisa a viabilidade económica e a potencial produção de biocombustíveis (gás natural) a partir de recursos lignocelulósicos da biomassa residual de palha de cana-de-açúcar e biomassa resíduos florestais (BRF) no Brasil e em Portugal respectivamente. A rota de transformação baseou-se na gaseificação da biomassa em um gaseificador de leito circulante e ar atmosférico como agente oxidante. Os resultados evidenciam que, em termos lucrativos, o cenário brasileiro se mostrou mais atraente do que o português para uma fábrica de gaseificação autónoma. Já para uma fábrica anexa em uma indústria de papel e celulose, o cenário português se apresenta mais vantajoso. Contudo, tratando-se de disponibilidade de matéria-prima, o território brasileiro torna-se mais competitivo devido à extensa área de produção agricola. Essas pecuciliaridades demonstram que a transformação da biomassa residual em combustíveis avançados por meio da gaseificação ainda carece de investigação, fator este que limita os investidores privados a explorar essa rota. Por fim, sugerem-se maiores incentivos e medidas regulatórias para implementar o desenvolvimento de novas rotas de transformação de biomassa para biocombustíveis avançados

Aprovechamiento de pasturas en estado reproductivo y desempeño de corderas en la Patagonia Austral

En el sur de Santa Cruz se desarrolló un trabajo con el objetivo de evaluar el aprovechamiento de una pastura pura (PP) de pasto ovillo (Dactylis glomerata L.) y una pastura mezcla (PM) de pasto ovillo y agropro intermedio (Agropyron intermedium (Host) Beavois en estado reproductivo y el desempeño productivo de corderas desde el 29 de diciembre al 08 de abril de la temporada 2020-2021. En un lote de animales señalados elegidos al azar de tres campos se determinó el peso vivo (PV) inicial y final (I y F), ganancias y rangos de PVI y PVF y la condición corporal (CC) I y F. Las pasturas se muestrearon en las fechas establecidas de uso para determinar la cobertura vegetal (CV), biomasa aérea (BA), altura de plantas (AP), material vivo y muerto (MV y MM), proteína bruta (PB), fibra en detergente neutro y ácida (FDN y FDA) y digestibilidad de la materia seca (DMS). Se calcularon la BA digestible y desaparecida mediante fórmula. El trabajo incluyó registros de lluvias y temperaturas. El análisis estadístico relacionó la CV y AP con la BAI y BAF y la PB, FDN, FDA y DMS de las PP y PM con el MM recolectado. En los animales, se establecieron asociaciones entre el PV y la CC por fecha, y el MV, PB y DMS con el PV. En la PM, la BA se redujo a la mitad al final del pastoreo con una caída apreciable del MV que aumentó el MM. La PB, FDN y FDA de ambas pasturas correlacionaron con el MM. Hubo una mejora en el PVF por rango del lote de corderas evaluadas. Se concluye la necesidad de ajustar, entre otras prácticas, la carga animal, ingreso y tiempos de pastoreo que permitan un mayor aprovechamiento de este tipo de pasturas en los momentos de mejor calidad nutricional.EEA Santa CruzFil: Utrilla, Víctor Ricardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz. Grupo Producción Agropecuaria; Argentina.Fil: Utrilla, Víctor Ricardo. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Andrade, Miguel Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Andrade, Miguel Alberto. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Gallardo, Rodrigo Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina

Propuesta para un Plan Ganadero Ovino de la Provincia de Santa Cruz. Agosto de 2017

La finalidad del presente Plan Ganadero Ovino Provincial será el de mejorar la competitividad, el desarrollo y la sustentabilidad del sistema ovino extensivo en la provincia de Santa Cruz. El presente Plan involucra a toda la cadena productiva, así como Instituciones públicas y privadas. Este documento sentará las bases y dará las pautas de priorización de las futuras líneas de acción en la ganadería ovina, a ser financiadas por la Unidad Ejecutora Provincial (U.E.P.) de la Ley Ovina Nacional nº 25.422. Se parte de la premisa que no existe una única solución integral para todos los establecimientos si se utiliza un único enfoque, como puede ser tener mayor rentabilidad en condiciones de mercado. Habrá que reconocer que mientras algunos predios pueden comprometerse en algunos aspectos relacionados con la rentabilidad propuestos, otros deberán enfocarse en objetivos relacionados con la preservación del medio ambiente o la ocupación sustentable del territorio.EEA Santa CruzFil: Schorr, Alan Geoffrey. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Santana, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz. Agencia de Extensión Rural Río Gallegos; Argentina.Fil: Andrade, Miguel Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Andrade, Miguel Alberto. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina

Penile prosthesis implantation in an academic institution in Latin America

PURPOSE: We performed a retrospective study to analyze the effectiveness of implantable penile prostheses in the treatment of erectile dysfunction. MATERIALS AND METHODS: This study included 249 patients who received implants between 2001 and 2008. A total of 139 patients who underwent penile prosthesis implantation were interviewed. RESULTS: Approximately half of patients had previously used oral drugs before implantation of the prosthesis. About 45% had diabetes, 25.9% had previously undergone radical prostatectomy (RP), and 64% had hypertension. Exchange was performed in 5.7% for fracture, inadequate size, or extrusion. A total of 24.5% of men had immediate postoperative pain, 7.9% had local infection, and 8.6% had other complications. Patients who had previously undergone RP were 3.2 times more likely to experience a postoperative complication than patients who had not (p = 0.061). Eighty-nine (64%) patients returned to having sex as they had before being diagnosed with ED. Ninety-two of the men (66.2%) had sexual intercourse one to two times per week. One hundred twenty patients (86.3%) rated their level of satisfaction as good, excellent or very good, which was similar to the percentage of partners. The mean follow-up was 40 months. CONCLUSION: Higher rates of postoperative infections and mechanical problems with the implant were found in this study as compared to other studies, which was probably associated with the relative lack of experience of the trainees who were performing the surgeries. Patients with a history of RP or diabetes mellitus prior to implantation were at higher risk of postoperative complications

Natural-based hydrogels for tissue engineering applications

In the field of tissue engineering and regenerative medicine, hydrogels are used as biomaterials to support cell attachment and promote tissue regeneration due to their unique biomimetic characteristics. The use of natural-origin materials significantly influenced the origin and progress of the field due to their ability to mimic the native tissuesâ extracellular matrix and biocompatibility. However, the majority of these natural materials failed to provide satisfactory cues to guide cell differentiation toward the formation of new tissues. In addition, the integration of technological advances, such as 3D printing, microfluidics and nanotechnology, in tissue engineering has obsoleted the first generation of natural-origin hydrogels. During the last decade, a new generation of hydrogels has emerged to meet the specific tissue necessities, to be used with state-of-the-art techniques and to capitalize the intrinsic characteristics of natural-based materials. In this review, we briefly examine important hydrogel crosslinking mechanisms. Then, the latest developments in engineering natural-based hydrogels are investigated and major applications in the field of tissue engineering and regenerative medicine are highlighted. Finally, the current limitations, future challenges and opportunities in this field are discussed to encourage realistic developments for the clinical translation of tissue engineering strategies.Authors acknowledge financial support from the European Union Framework Programme for Research and Innovation Horizon 2020 under European Research Council grant agreement No. 772817; FCT (Fundação para a Ciência e a Tecnologia) for individual fellowship CEECIND/01375/2017 (MGF); FCT for project PTDC/NAN-MAT/30595/2017; Xunta de Galicia for postdoctoral fellowship ED481B-2019-025 (AP); Norwegian Research Council (NFR) for project No. 287953

Unraveling the Holocene Eruptive History of Flores Island (Azores) Through the Analysis of Lacustrine Sedimentary Records

Lacustrine sequences from active volcanic settings usually hold a rich and continuous record of tephra layers, providing a critical source of information to reconstruct a most complete eruptive history of a region. Lake sedimentary records on volcanic islands are particularly useful as the typical small size of these islands and their steep subaerial and submarine slopes lead to a lower preservation of potential erodible pyroclastic deposits. Here we explore the lacustrine sedimentary record of Lagoa da Lomba, a crater lake in the central upland area of Flores Island (Azores), to gain insight into the recent eruptive history of this island. The strategic location of Lagoa da Lomba, half distance between the two clusters of recent volcanic activity of the island, together with its long-lasting record, back to 23.52 cal kyr BP, makes this lake a privileged site to investigate the Holocene volcanic history of Flores. Based on a detailed stratigraphic characterization of sediments from a lake transect of three cores, supported by glass shard geochemistry and radiocarbon dating, we recognized four Holocene eruptive events taking place between 6.28 and 2.36 cal kyr BP, demonstrating that the Holocene volcanic activity at Flores Island may have lasted longer than previously reported. Glass shard geochemistry from the different tephra layers suggests three populations, basaltic to trachybasaltic in composition, where the last eruption is the least evolved endmember. Two of the four eruptive events correlate with subaerially-exposed pyroclastic sequences, in terms of stratigraphy and geochemistry. The most recent event recorded at Lagoa da Lomba was constrained to 3.66 - 2.36 cal kyr BP and linked to an eruption sourced from Lagoa Comprida Volcanic System. The second most recent eruptive event was sourced from Lagoa Funda Volcanic System and dated at 3.66 cal kyr BP. Our observations show that Flores experienced vigorous volcanic activity during the Late Holocene. Therefore, contrary to what is assumed, the possibility of future eruptions should be properly considered, and the volcanic hazard here should not be underestimated. Moreover, we highlight the importance of tephrostratigraphy in recent lake sediments to reconstruct past volcanic activity, especially at small volcanic islands, such as Flores, where exposure is poor due to erosion within the limited subaerial area and the dense vegetation

Guiding stem cell tenogenesis by modulation of growth factor signaling and cell-scale biophysical cues in bioengineered constructs

Tendon injuries and tendinopathies are increasingly prevalent health problems currently lacking effective treatments. Tissue engineering offers promising strategies to boost the low innate regenerative ability of tendons. Within this context, the simultaneous leveraging of both physical and biochemical cues by engineered scaffolding systems can be explored to promote a stronger tenogenic response from stem cells. Here, molecularly imprinted polymeric nanoparticles (MINPs) against transforming growth factor (TGF)-β3 are combined with bioinspired anisotropic hydrogels to produce tenogenesis-inductive constructs. MINPs are first solid phase-imprinted against a TGF-β3 epitope, achieving an affinity comparable to monoclonal antibodies. MINPs and magnetically-responsive microfibers are then encapsulated together with adipose-derived stem cells within gelatin-based hydrogels, applying a magnetostatic field during gelation to align the microfibers. The created anisotropic microstructure guides cell growth and elongation unidirectionally, while MINPs act as artificial receptors for TGF-β3, potentiating its paracrine action in the cellular microenvironment. The combination of both stimuli proves effective at increasing TGF-β signaling, which promotes the expression of tendon-associated genes and corresponding protein synthesis, suggesting that microstructural cues and biomolecule sequestration act in tandem to direct cell fate commitment. Overall, this system recapitulates several elements of tendon development, constituting a promising strategy for the regeneration of this tissue