Savannah land cover characterisation: a quality assessment using Sentinel 1/2, Landsat, PALSAR and PlanetScope

The importance of savannahs worldwide has been widely acknowledged and documented. They are important ecosystems that are found on almost half of the African continent and a fifth of the Earth’s surface. They consist of varying densities of grasses and woody vegetation and,due to their complexity, they have been centre stage for a number of land system science debates, such as, equilibrium dynamics, land degradation and desertification, or their contribution to the global carbon cycle, to name but a few. Their significance is directly linked to the numerous recent efforts to map and monitor their land cover as accurately as possible, most commonly by employing Earth observation technologies. A recent case study by Symeonakis et al. (2018), carried out in a southern African savannah covering an area of ~44,000km2, tested the performance of different combinations of Landsat- and PALSAR-based metrics from the dry and wet seasons. They concluded that the combination of multi-sensor and multi-season data provides the best results when mapping the main land cover types of woody vegetation, grasses, crops and urban/bare. Here, we take this work further by testing the performance of 15 similar models, this time based on a combination of Sentinel-1 and Sentinel-2 metrics from the dry and wet season, using the same study area, training and validation samples (extracted from 0.5 m RGB aerial photography). Our results corroborate the findings of the previous study: the combination of the Sentinel optical and C-band radar data from both seasons yielded the most accurate land cover Random Forests classifications: overall accuracy of 87%, overall k: 0.83. Very high user’s and producer’s accuracies were also found, especially for the woody class (User’s: 93%; Producer’s: 93%), which is of primary concern in these savannah environments, due to its relevance to the land degradation processes that are dominant in the region: bush encroachment, overexploitation for fuelwood and deforestation. Similar to the Landsat/PALSAR study, the models based on SAR data only, were less accurate than the optical models. As anticipated, the L-band PALSAR data used in the previous study performed better in mapping the woody cover than their C-band counterparts, since L-band radiation is able to penetrate through the canopy layer and reach the woody stems and branches more efficiently. However, and interestingly, the Landsat-PALSAR study generally outperformed the Sentinel1/2 study, e.g. reporting the same omission but a 5% lower commission error for the woody class (estimated from the all-parameter model). Additionally, we tested a novel land cover configuration mapping accuracy approach using PlanetScope 3m-pixel data, with the view to assessing the quality of the mapping of landscape configuration (e.g. number of crop paddocks) and not only its composition (e.g. crop vs other cover). For five test areas of 170 km2 each, we performed object-based classifications of the PlanetScope imagery (two images per test area, one from the dry and one from the wet season). The results were less promising than those achieved for land cover composition: as an example, in one of our areas of focus, we determined 30 crop paddocks, 28 of which were of the circular centre pivot type ranging from 0.06 to 0.75 km2. For the same area, we mapped a significantly larger number of paddocks with the Sentinel 2 data, most of which were of the rectangular-shaped type. This discrepancy was attributed to the spectral similarity between the crop and grass land cover types, as well as the averaging effect of the lower spatial resolution of the Sentinel. Our findings, however, suggesting a multi-sensor and multi-seasonal approach, are an important addition to the emerging literature and can be used to guide efforts for achieving a highly accurate savannah land cover characterisation. Future work will investigate the use of the PlanetScope object-based classifications as training of the coarser-resolution models (e.g. Seninel 1- and 2-based metrics), not only for improving the mapping of land cover configuration, but also for mapping fractional cover, e.g. % woody vegetation

Mycobacterium paratuberculosis sheep type strain in Uruguay: evidence for a wider geographic distribution in South America

Johne's disease (JD) is an economically important disease of ruminants caused by Mycobacterium avium paratuberculosis (MAP), which also infects other species including humans. Two major MAP strain types are currently recognized: sheep (S) and cattle (C) types. Information on JD prevalence and MAP types infecting small ruminants in South America is limited, and all but one of the MAP types reported from this region are of the C type. This study describes clinicopathological, molecular and microbiological findings in 11 cases of JD caused by a type S MAP strain, and estimated true within-flock prevalence in a ~735-sheep operation in Uruguay. Postmortem examination and histology (hematoxylin-eosin and Ziehl-Neelsen stains) of samples from 41 selected sheep revealed lymphohistiocytic/granulomatous enteritis and mesenteric lymphadenitis in 11 animals, with moderate/severe multibacillary lesions in 6 clinical cases, and minimal/mild paucibacillary lesions in 5 sub-clinical cases. Immunohistochemistry using an antibody against Mycobacterium bovis that cross-reacts with MAP (2 cases), and transmission electron microscopy (1 case), revealed myriads of intrahistiocytic mycobacteria. MAP was isolated in one case and detected by PCR in 6 cases. The S type of MAP was identified using a multiplex PCR that distinguishes between S and C types, and PCR-REA. The estimated true within-flock prevalence was ≤ 2.3%. This represents the first communication on within-flock prevalence of JD associated with a type S MAP strain in South America and the second documentation of this strain in the subcontinent. Additional studies are required to better understand the molecular epidemiology of the different MAP types in the region.Centro de Diagnóstico e Investigaciones Veterinaria

Cyclodextrin Complexes of Reduced Bromonoscapine in Guar Gum Microspheres Enhance Colonic Drug Delivery

Here, we report improved solubility and enhanced colonic delivery of reduced bromonoscapine (Red-Br-Nos), a cyclic ether brominated analogue of noscapine, upon encapsulation of its cyclodextrin (CD) complexes in bioresponsive guar gum microspheres (GGM). Phase−solubility analysis suggested that Red-Br-Nos complexed with β-CD and methyl-β-CD in a 1:1 stoichiometry, with a stability constant (Kc) of 2.29 × 103 M−1 and 4.27 × 103 M−1. Fourier transforms infrared spectroscopy indicated entrance of an O−CH2 or OCH3−C6H4−OCH3 moiety of Red-Br-Nos in the β-CD or methyl-β- CD cavity. Furthermore, the cage complex of Red-Br-Nos with β-CD and methyl-β-CD was validated by several spectral techniques. Rotating frame Overhauser enhancement spectroscopy revealed that the Ha proton of the OCH3−C6H4−OCH3 moiety was closer to the H5 proton of β-CD and the H3 proton of the methyl-β-CD cavity. The solubility of Red-Br-Nos in phosphate buffer saline (PBS, pH ∼ 7.4) was improved by ∼10.7-fold and ∼21.2-fold when mixed with β-CD and methyl-β-CD, respectively. This increase in solubility led to a favorable decline in the IC50 by ∼2-fold and ∼3-fold for Red-Br-Nos−β-CD-GGM and Red-Br-Nos−methyl-β-CD-GGM formulations respectively, compared to free Red-Br-Nos−β-CD and Red-Br-Nos−methyl-β-CD in human colon HT-29 cells. GGM-bearing drug complex formulations were found to be highly cytotoxic to the HT-29 cell line and further effective with simultaneous continuous release of Red-Br-Nos from microspheres. This is the first study to showing the preparation of drug-complex loaded GGMS for colon delivery of Red-Br-Nos that warrants preclinical assessment for the effective management of colon cancer

Developmental adaptation to high altitude hypoxia

Experimental studies on animals and humans exposed to hypoxic stress have been reviewed. These data suggest that the influence of hypoxic stress, and the organism's response to it, are greater during growth than during adulthood. The organism's responses include alterations in the quantity and size of the alveolar units of the lungs, enlargement of the right ventricle of the heart, slower somatic growth as measured by birth weight and body size, increased aerobic capacity during maximal work, and greater control of ventilation. It is postulated that the organism is more sensitive to the influence of environmental factors during growth and development than during adulthood. Consequently, adaptive traits acquired during the developmental period have profound, long-term consequences, which are reflected in the physiological and morphological characteristics of the adult organism. It is concluded that the differences between the highland and lowland natives in their physiological performance and morphology are mostly due to adaptations acquired during the developmental period.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47840/1/484_2005_Article_BF01553707.pd

Qué factores determinan que las ovejas tengan un alto porcentaje de ovulación y una alta tasa ovulatoria?. Análisis de 20 experimentos realizados en INIA La Estanzuela e INIA Treinta y Tres con ovejas Corriedale, Ideal e Ideal x Frisona Milchschaf.

El presente artículo capitaliza un gran volumen de información generada por INIA , apuntando a una mayor comprensión del efecto del tipo y duración de lasuplementación (en particular el rol de la proteína y la energía) sobre la ovulación y la tasa ovulatoria en ovinos

Producción ovina intensiva: eficiencia y competitividad.

La producción en pequeña escala demanda producir en máximos niveles de eficiencia, como contraparte permite manejos individualizados que potencian los resultados obtenidos. En ellos el ovino ha encontrado un espacio en el cual insertarse, constituyéndose en un reducto cultural de mucho valor para el futuro de nuestra sociedad rural. Sin embargo, las prácticas de manejo generales que buscan eficiencia y competitividad en un sistema de producción de corderos son universalmente aplicables a cualquier escala y constituyen una opción muy interesante sobre campos que admitan algún grado de intensificación en su base forrajera

Biotipos maternales ovinos: pilares de una producción eficiente.

Desde hace algunos años la producción ovina intensiva se ha transformado en una alternativa muy exitosa en predios de escala reducida, lo que ha permitido la mejora de la competitividad y de los resultados económicos y ha significado un estímulo para quienes han querido insertarse en la producción ovina y en el medio rural. Este éxito se sustenta en dos conceptos claves: máxima eficiencia biológica y bajos costos de producción

Relevamiento de problemas sanitarios y de manejo durante la terminación en bovinos en sistemas de confinamiento en Uruguay / Survey of health and management problems during finishing in cattle in confinement systems in Uruguay.

En los últimos años ha habido un cambio en los sistemas de engorde en Uruguay, con un incremento importante del engorde a corral. Esto podría implicar que se presenten problemas sanitarios diferentes a los que se presentan en sistemas pastoriles tradicionales y del cual no se cuenta con información objetiva. El objetivo de este trabajo fue el de relevar información sobre los potenciales problemas sanitarios y de manejo en los sistemas de engorde a corral de Uruguay. La metodología aplicada fue la de encuesta mediante cuestionario el cual constó de 46 preguntas, administrado mediante entrevista personal a los dueños o encargados de establecimientos identificados que realizan engorde a corral durante un período de al menos 100 días. El período de estudio fue entre abril y diciembre de 2012. De un total de 84 establecimientos registrados que realizaban engorde a corral al momento de la encuesta 71 de ellos respondieron, resultando en una tasa de respuesta de 84,5%. Los principales resultados mostraron que la acidosis junto a los problemas podales y las enfermedades clostridiales fueron identificadas como importantes en el 25% de los establecimientos, mientras que los problemas urinarios (principalmente la urolitiasis) se registraron en el 20% de los establecimientos y los problemas respiratorios sólo ocuparon el 10% de la casuística de enfermedades.El promedio de mortalidad en estos encierros fue de 0,43% (rango= 0,02% y 1,0%), identificándose la indigestión/acidosis responsable del 44% de las causas de muertes.Summary: Uruguayan traditional beef cattle finishing systems has changed during the last years, with an important number of animals being finished under confinement feeding. This might suggest that animal health problems in these production systems are different from those already present under grazingconditions. The objective of this study was to obtain information on potential health problems in beef cattle under feed lot systems in Uruguay. A questionnaire-based survey was designed and presented to feedlots owners or managers as personal interview, during April-December 2012. A total of 71 farmers (n=84) responded, resulting in a response rate of 84.5%. Results from this surveys demonstrated that acidosis, clostridia diseases and foot problems were present in oneout of four of the interviewed farms; urinary problems were present in 20% of the farms and respiratory problems in one out of ten. The average mortality was 0.43% (Range: 0.02% to 1.0%), being the digestive problems responsible for 44% of the death