Geometric predictors of abdominal aortic aneurysm maximum wall stress

Abdominal aortic aneurysm (AAA) is a dilation of the abdominal aorta (above 50 % of its original diameter), which can cause death upon rupturing. It usually grows asymptomatically leading to late clinical intervention. The medical criteria to indicate surgery are based on measuring the diameter and growth rate, but in many cases aneurysms fail at uncharacterized critical values. In search of a more efficient technique in predicting AAA failure, there is consensus on the importance of studying its geometric characteristics and estimation of the wall stress, but no fully successful correlation has been found between the two yet. This work examines the relationship between a parameterized geometry (18 input variables and 10 dependent indices) and 1 output variable: the maximum wall stress

Extensiones autoadjuntas hamiltonianas en un intervalo de la recta real: El operador energía cinética.

Based on physical arguments, we find the position, momentum, and kinetic energy operators in the interval (0, ℓ) of the real line. We characterize the domain of the canonical commutation rule (between position and momentum operators) and the validity of the uncertainty principle.Haciendo uso de argumentos fı´sicos, hallamos los operadores momentum y energı´a cin´etica en el intervalo (0, ℓ) de la recta real, ası´ como el operador posici´on. Caracterizamos el dominio de la regla can´onica de conmutaci´on (entre los operadores posici´on y momentum) y de validez del principio de incertidumbre

Conservation strategies to mitigate impacts from climate change in Amazonia

Protected area systems and conservation corridors can help mitigate the impacts of climate change on Amazonian biodiversity. We propose conservation design criteria that will help species survive in situ or adjust range distributions in response to increased drought. The first priority is to protect the western Amazon, identified as the ‘Core Amazon’, due to stable rainfall regimes and macro-ecological phenomena that have led to the evolution of high levels of biodiversity. Ecotones can buffer the impact from climate change because populations are genetically adapted to climate extremes, particularly seasonality, because high levels of habitat diversity are associated with edaphic variability. Future climatic tension zones should be surveyed for geomorphological features that capture rain or conserve soil moisture to identify potential refugia for humid forest species. Conservation corridors should span environmental gradients to ensure that species can shift range distributions. Riparian corridors provide protection to both terrestrial and aquatic ecosystems. Multiple potential altitudinal corridors exist in the Andes, but natural and anthropogenic bottlenecks will constrain the ability of species to shift their ranges and adapt to climate change. Planned infrastructure investments are a serious threat to the potential to consolidate corridors over the short and medium term

The Added Complications of Climate Change: Understanding and Managing Biodiversity, Ecosystems, and Ecosystem Services Under Multiple Stressors.

Ecosystems around the world are already threatened by land-use and land-cover change, extraction of natural resources, biological disturbances, and pollution. These environmental stressors have been the primary source of ecosystem degradation to date, and climate change is now exacerbating some of their effects. Ecosystems already under stress are likely to have more rapid and acute reactions to climate change; it is therefore useful to understand how multiple stresses will interact, especially as the magnitude of climate change increases. Understanding these interactions could be critically important in the design of climate adaptation strategies, especially because actions taken by other sectors (eg energy, agriculture, transportation) to address climate change may create new ecosystem stresses

Utilización de inóculos comerciales conteniendo bacterias productoras de ácido láctico sobre las características fermentativas y estabilidad aeróbica de ensilaje de maíz

This study evaluated two treatments based on addition of two commercial microbial inoculants of lactic acid-producing bacteria (LAPB), one of the homolactic type (HOT) and the other a combination of homolatic with heterolactic bacteria (HHT), plus a control treatment without inoculation (CNT), on the fermentative characteristics of tropical maize in micro-silos and aerobic stability (AS) of the resulting silage. The fermentative characteristics were determined in triplicate samples taken at various lengths of fermentation (15, 30, 58 and 90 d), which were analyzed for pH, concentration of organic acids and NHL. To evaluate AS, changes in pH and temperature of the silage were monitored during five days of exposure to air. No significant differences were found among treatments in any of the fermentation characteristics studied. HOT resulted in the numerically lowest average pH (4.23) and the highest average percentage content of lactic acid (2.18), followed by HHT (4.28 and 2.11) and CNT (4.32 and 1.94), respectively. Also, regarding indicators of AS there were no significant differences among treatments, but numerically the average pH of exposed HOT silage was lower (5.30 vs 5.43 the average value of both HHT and CNT) and there was a trend (P <0.15) toward lower average temperature (°C ) in favor of HHT (29.61 vs. 30.26 and 30.28 for HOT and CNT silages). In general, the use of LAPB inoculants in tropical maize silage did not result in large differences relative to non-inoculated silage in the variables under study regarding fermentation characteristics and AS.Se evaluaron dos tratamientos basados en la adición de dos inóculos microbianos comerciales, uno a base de bacterias productoras de ácido láctico (BPAL) homofermentativas (THO) y el otro una combinación de estas con heterofermentativas (THH), además de un tratamiento control sin inoculación (TCN), en sus efectos sobre las características fermentativas de maíz tropical en micro-silos y la estabilidad aeróbica (EA) del ensilaje resultante. Las características fermentativas se determinaron en muestras por triplicado, tomadas a diferentes largos de fermentación (15, 30, 58, y 90 d), que se analizaron para pH, concentración de ácidos orgánicos y NHL. Para evaluar la EA se monitoreó los cambios de pH y temperatura del ensilaje expuesto al aire durante cinco días. No se encontró diferencias significativas entre tratamientos en ninguna de las características fermentativas incluidas. Numéricamente el THO mostró en promedio el menor pH (4.23) y el mayor contenido porcentual de ácido láctico (AL) (2.18), seguido respectivamente por THH (4.28 y 2.11) y TCN (4.32 y 1.94). Los indicadores de EA tampoco difirieron significativamente entre tratamientos, pero hubo una diferencia en pH promedio del ensilaje expuesto, favorable a THO (5.30 vs 5.43 valor común en ambos THH y TCN); y una tendencia (P < 0.15) en temperatura promedio (°C) favorable a THH (29.61 vs 30.26 en THO y 30.28 en TCN). En general, el uso de los inóculos de BPAL en ensilaje de maíz tropical no resultó en grandes diferencias relativo a ensilaje no inoculado en las variables dependientes en estudio relativo a características fermentativas y EA.

Thirty Years of Land-cover Change in Bolivia

Land-cover change in eastern lowland Bolivia was documented using Landsat images from five epochs for all landscapes situated below the montane tree line at approximately 3000 m, including humid forest, inundated forest, seasonally dry forest, and cloud forest, as well as scrublands and grasslands. Deforestation in eastern Bolivia in 2004 covered 45 411 km2, representing;9% of the original forest cover, with an additional conversion of 9042 km2 of scrub and savanna habitats representing 17 % of total historical land-cover change. Annual rates of land-cover change increased from;400 km2 y1 in the 1960s to;2900 km2 y1 in the last epoch spanning 2001 to 2004. This study provides Bolivia with a spatially explicit information resource to monitor future land-cover change, a prerequisite for proposed mechanisms to compensate countries for reducing carbon emissions as a result of deforestation. A comparison of the most recent epoch with previous periods shows that policies enacted in the late 1990s to promote forest conservation had no observable impact on reducing deforestation and that deforestation actually increased in some protected areas. The rate of land-cover change continues to increase linearly nationwide, but is growing faster in the Santa Cruz department because of the expansion of mecha-nized agriculture and cattle farms

Consumo y digestibilidad de una dieta para corderos basada en henos de gramíneas tropicales y de Hyparrhenia rufa con un probiótico aportador de Bacillus subtilis y Bacillus licheniformi

An experiment consisting of two periods (P1 and P2) was conducted to determine the effect of adding a probiotic of bacterial strains of Bacillus subtilis and B. licheniformis to a basal diet of low quality grass hays on voluntary consumption (VC) and digestibility. Ten Creole lambs were randomly assigned to one of two treatments: control (without additive) or probiotic (with additive In diet). The basal diet consisted of a dally forage offering equal to 4% of live weight (LW) on a dry matter (DM) basis. The forage offered was 50% native grass hay [71.7% neutral detergent fiber (NDF), 4.9% crude protein (CP) in P1; and 71.2% NDF, 5.4% CP in P2], and 50% of Hyparrhenia rufa hay (78.8% NDF, 3.5% CP in P1; and 75.6% NDF, 5.5% CP in P2). The lambs were supplemented with 225 g of commercial concentrate (CC) daily. The additive was mixed with the CC to supply 1.33 X ICcfu/head daily during the 49 days of P1. From day 50 to 84 (P2), the probiotic addition was suspended to determine possible residual effects. The lambs were weighed weekly. The VC and digestibility of DM, NDF and CP were determined from day 42 to 49 in P1 and from day 77 to 84 in P2. The variables related to parasitism and anemia: fecal egg count (FEC), FAMACHA® index score and packed cell volume (PCV) were determined every 21 days. Data from each experimental period were analyzed according to a completely randomized design with five replicas per treatment. During P1, the daily LW gain of the lambs was 23 vs. 20 g for control and probiotic treatments, respectively. The dietary addition of probiotic increased (p < 0.05) total DM intake (445 vs. 484 g/d), DM intake as a percentage of LW (2.04 vs. 2.37) and forage DM as a percentage of total DM intake (54.77 vs. 59.42). The digestibility coefficients of DM (59.98 vs. 62.62%) and CP (59.35 vs. 61.76%) did not differ between treatments, but there was a tendency (p = 0.09) to improve NDF digestibility (58.71 vs. 62.48%) with probiotic addition. The FEC observed in the control and probiotic groups were 820 vs. 1,380 eggs/g initially and increased more in the control (p < 0.05) to 2,390 vs. 2,780 eggs/g at day 21, then decreased less in this group to 1,830 vs. 1,480 eggs/g at day 42. The PCV values changed between days 0 and 42 from 24.4 to 17.9% in the control and from 20.6 to 22.6% in the probiotic group, but without significant effects (p > 0.05). The anemia level according to FAMACHA® score differed little between treatments and did not exceed a maximum of 2.6. During P2, the LW gain of the lambs of both control and previously probiotic treated groups was 48 g/d. Total DM intake was 587 vs. 562 g/d and digestibilities were: DM (58.46 vs. 57.59%), NDF (57.50 vs. 56.85%) and CP (60.78 vs. 62.11%) without significant differences (p > 0.05). The FEC decreased progressively to respective final values at 84 days of 1,230 vs. 440 eggs/g, whereas the PCV increased to 23.4 vs. 25.1% at day 84 without significant differences. The maximum FAMACHA® score was 2.8 vs. 2.2 in the two respective treatments. In summary, the addition of the probiotic in the diet improved VC and tended to increase NDF digestibility, but did not affect growth, even though there were signs of animal health benefiting. After suspending the use of the additive, no residual effect on the variables evaluated was observed.Se realizó un experimento en dos periodos (P1 y P2) para determinar el efecto de la inclusión de un probiótico aportador de las bacterias Bacillus subtilis y B. licheniformis en una dieta basada en henos de gramíneas de baja calidad sobre el consumo voluntario (CV) y digestibilidad utilizando 10 corderos criollos. Los corderos se asignaron aleatoriamente a uno de dos tratamientos: sin (control) o con el probiótico dietético. La dieta basal constó de un ofrecimiento diario de forraje igual al 4% del peso vivo (PV) en la materia seca (MS). El forraje consistió de 50% de heno de gramíneas tropicales naturalizadas [71.7% Fibra Detergente Neutra (FDN), 4.9% Proteína Bruta (PB) en P1; y 71.2% FDN, 5.4% PB en P2] y 50% de heno de Hyparrhenia rufa (78.8% FDN, 3.5% PB en P1; y 75.6% FDN, 5.5% PB en P2). Se suplió también 225 g diarios de concentrado comercial (CC). El aditivo se mezcló con el CC para suplir 1.33 X 10 ufe/animal diariamente durante 49 días en P1. Del día 50 al 84 (P2) se suspendió el ofrecimiento del aditivo para determinar posibles efectos residuales de este. Se pesaron los corderos semanalmente. El CV y digestibilidad de la MS, FDN y PB se determinaron del día 42 al 49 en P1. y del día 77 al 84 en P2. Las variables indicativas de parasitismo y anemia: conteo de huevos en las heces (CHH), valor FAMACHA® y hematocrito, se determinaron cada 21 días. Los datos por periodo experimental se analizaron según un diseño completamente aleatorizado con cinco repeticiones por tratamiento. Durante el P1, la ganancia en PV de los ovinos fue de 23 vs. 20 g/día para los tratamientos control y con probiótico, respectivamente. La adición dietética del probiótico aumentó (p < 0.05) el consumo total de MS (445 vs. 484 g/d), dicho consumo como porcentaje del PV (2.04 vs. 2.37), además del consumo de MS de forraje como porcentaje del consumo de MS total (54.77 vs. 59.42). La digestibilidad porcentual de MS (59.98 vs. 62.62) y de PB (59.35 vs. 61.76) no difirió entre tratamientos, pero hubo tendencia (p = 0.09) a mejorar la digestibilidad de FDN con el probiótico (58.71 vs. 62.48). El CHH de los respectivos grupos testigo y con probiótico fue 820 vs. 1,380 huevos/g ¡nlclalmente y aumentó más (p < 0.05) en el testigo a 2,390 vs. 2,780 huevos/g al día 21 y luego bajó a 1,830 vs. 1,480 huevos/g al día 42. Entre los días 0 y 42, el hematocrlto cambió significativamente (p > 0.05) de 24.4 a 17.9 en el testigo y de 20.6 a 22.6 en el grupo con problótlco. El nivel de anemia estimado por FAMACHA® difirió mínimamente entre ambos tratamientos y no pasó de un valor máximo de 2.6. Durante el P2, la ganancia en PV de los ovinos de ambos grupos (testigo y previamente con el problótlco) fue 48 g/ día. Al comparar estos dos respectivos grupos, el consumo de MS fue 587 vs. 562 g/día y las dlgestlbllldades fueron: MS (58.46 vs. 57.59%), FDN (57.50 vs. 56.85%) y PB (60.78 vs. 62.11%), sin diferencias (p > 0.05). El CHH bajó progresivamente a respectivos valores finales de 1,230 y 440 huevos/g a los 84 días, mientras el hematocrlto subió a valores de 23.4 y 25.1% a los 84 días, sin diferencias (p > 0.05). El valor máximo de FAMACHA® fue de 2.8 y 2.2 en los dos respectivos tratamientos. En resumen, la adición dietética del probiótico incentivó el CV y tendió a aumentar la digestibilidad de FDN, pero no afectó el crecimiento, aunque dio ciertos indicios de favorecer la salud animal. Después de suspender el aditivo, no se observó ningún efecto residual del mismo sobre las variables evaluadas

Symbiosis between Cretaceous dinosaurs and feather-feeding beetles

Extant terrestrial vertebrates, including birds, have a panoply of symbiotic relationships with many insects and arachnids, such as parasitism or mutualism. Yet, identifying arthropod-vertebrate symbioses in the fossil record has been based largely on indirect evidence; findings of direct association between arthropod guests and dinosaur host remains are exceedingly scarce. Here, we present direct and indirect evidence demonstrating that beetle larvae fed on feathers from an undetermined theropod host (avian or nonavian) 105 million y ago. An exceptional amber assemblage is reported of larval molts (exuviae) intimately associated with plumulaceous feather and other remains, as well as three additional amber pieces preserving isolated conspecific exuviae. Samples were found in the roughly coeval Spanish amber deposits of El Soplao, San Just, and Peñacerrada I. Integration of the morphological, systematic, and taphonomic data shows that the beetle larval exuviae, belonging to three developmental stages, are most consistent with skin/hide beetles (family Dermestidae), an ecologically important group with extant keratophagous species that commonly inhabit bird and mammal nests. These findings show that a symbiotic relationship involving keratophagy comparable to that of beetles and birds in current ecosystems existed between their Early Cretaceous relatives

Correction to: Determining puma habitat suitability in the Eastern USA (Biodiversity and Conservation, (2023), 10.1007/s10531-022-02529-z)

In the original article, One of the author names was incorrectly misspelled as Tom Bulter. It must be published as “Tom Butler”. The original article has been corrected

Determining puma habitat suitability in the Eastern USA

Pumas (Puma concolor) were eliminated from most of the eastern USA a century ago. In the past couple of decades, their recovery in the West has increased puma dispersal into the Midwest, with some individuals even traveling to the East Coast. We combined published expert opinion data and a habitat suitability index in an analysis that identified 17 areas in the Upper Midwest, Ozarks, Appalachia, and New England that could potentially host puma populations in the future. Thirteen of these were larger than 10,000 km2 and so likely to ensure a puma population’s long-term genetic health. Further, we quantified patch size, human density, livestock density, percent public land, and a sociocultural index reflecting wildlife values for comparing patches, as well as present a summary of current legislation relevant to puma management in the East. Our work may be useful in identifying suitable areas to restore pumas based not only on the quality of their biophysical habitat, but also on social values conducive to puma-human coexistence