3,332 research outputs found
NIRS potential use for the determination of natural resources quality from dehesa (acorn and grass) in Montanera system for Iberian pigs.
NIRS technology has been used as an alternative to conventional methods to determinate the content of nutrients of acorns and grass from dehesa ecosystem. Dry matter (DM), crude fat (CF), crude protein (CP), starch, total phenolic compounds (TP), α-tocopherol, γ-tocopherol, fatty acids, neutral detergent fiber (NDF), total antioxidant activity (TAA) and total energy (TE) were determined by conventional methods for later development of NIRS predictive equations. The NIR spectrum of each sample was collected and for all studied parameters, a predictive model was obtained and external validated. Good prediction equations were obtained for moisture, crude fat, crude protein, total energy and γ-tocopherol in acorns samples, with high coefficients of correlation (1-VR) and low standard error of prediction (SEP) (1-VR=0.81, SEP=2.62; 1-VR=0.92, SEP=0.54; 1-VR=0.86, SEP=0.47; 1-VR=0.84, SEP=0.2; 1-VR=0.88, SEP=5.4, respectively) and crude protein, NDF, α-tocopherol and linolenic acid content in grass samples (1-VR=0.9, SEP=1.99; 1-VR=0.87, SEP=4.13; 1-VR=0.76, SEP=10.9; 1-VR=0.82, SEP=0.6, respectively). Therefore, these prediction models could be used to determinate the nutritional composition of Montanera natural resources
Perturbation theory for very long-range potentials
Systems with very long-range interactions (that decay at large distances like
with where is the space dimensionality) are
difficult to study by conventional statistical mechanics perturbation methods.
Examples of these systems are gravitational and charged (non-electroneutral).
In this work we propose two alternative methodologies to avoid these
difficulties and capture some of the properties of the original potential. The
first one consists in expressing the original potential in terms of a finite
sum of hard-core Yukawa potentials. In the second one, the potential is
rewritten as a damped potential, using a damping function with a parameter that
controls the range of the interaction. These new potentials, which mimic the
original one, can now be treated by conventional statistical mechanics methods.Comment: 25 pages, 11 figure
Seniors’ ability to decode differently aged facial emotional expressions
The present investigation aims at assessing elders' ability to decode facial emotional expressions conveyed by differently aged people in order to confirm (or disconfirm) the appropriateness of the 'own age bias' theory, as well as investigate effects of different ages and different emotional categories. The study, involves 44 healthy elders (23 females), aged 65+ (mean age=75.09; SD=±7.9) which were requested to label 76 pictures depicting elders, middle-aged and young women and men displaying the six facial emotional expressions of disgust, anger, fear, sadness, happiness and neutrality. Results show a complex pattern of influences that calls for more deep investigations on the features to be accounted by providing socially and emotionally believable interfaces of effective and efficient algorithms to detect and decode their users' emotional facial expressions
Molt and reproduction of understory birds in the Allpahuayo Mishana National Reserve, Loreto, Peru
The processes of molt and reproduction, and the overlap of the two during a bird's life, are practically unstudied in most tropical environments in South America, especially in Peruvian Amazonia. Our study contributes to understanding these processes in this Neotropical region by analyzing data on molt and reproduction of the understory avifauna and their relationship to different biotic environmental (flowering and fruiting) and abiotic factors (precipitation, temperature) during one year in the Allpahuayo Mishana National Reserve in northeastern Peru. A total of 1556 individuals, belonging to 108 species, were captured, of which 847 were molting. Likewise, only 89 individuals were found with a fully vascularized brood patch. However, the level of overlap with molting was high, as a total of 44 (49%) of the birds with a brood patch were also molting primaries. We found that both molt and reproduction occurred throughout the year, with peaks in June-July (the less rainy season) and October-November (the beginning of the rainy season). There was a positive correlation between molt and breeding, and a negative correlation between the presence of juveniles and the fruiting of woody plants. However, we found no statistically significant correlation of molt or reproduction with precipitation, temperature, flowering, and fruiting seasons of woody plants. These results may be subject to the influence of climatological factors and the availability of food resources, such as arthropods, that were not covered in this study. Furthermore, inference is limited due to the relatively short time frame of the study
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Influence of Pore Size on Carbon Dioxide Diffusion in Two Isoreticular Metal-Organic Frameworks
The rapid diffusion of molecules in porous materials is critical for numerous applications including separations, energy storage, sensing, and catalysis. A common strategy for tuning guest diffusion rates is to vary the material pore size, although detailed studies that isolate the effect of changing this particular variable are lacking. Here, we begin to address this challenge by measuring the diffusion of carbon dioxide in two isoreticular metal-organic frameworks featuring channels with different diameters, Zn2(dobdc) (dobdc4- = 2,5-dioxidobenzene-1,4-dicarboxylate) and Zn2(dobpdc) (dobpdc4- = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate), using pulsed field gradient NMR spectroscopy. An increase in the pore diameter from 15 Å in Zn2(dobdc) to 22 Å in Zn2(dobpdc) is accompanied by an increase in the self-diffusion of CO2 by a factor of 4 to 6, depending on the gas pressure. Analysis of the diffusion anisotropy in Zn2(dobdc) reveals that the self-diffusion coefficient for motion of CO2 along the framework channels is at least 10000 times greater than for motion between the framework channels. Our findings should aid the design of improved porous materials for a range of applications where diffusion plays a critical role in determining performance
Cadmium exposure and breast cancer risk: a systematic review and dose-response meta-analysis of cohort studies
Background and aim: Cadmium is a heavy metal which has been implicated in breast cancer etiology because of its toxic properties such as endocrine disruption. The general population is exposed to cadmium through dietary intake, cigarette smoking, emissions of motorized traffic and industrial facilities. We carried out a systematic review and dose-response meta-analysis of the cohort studies investigating the association between cadmium exposure and breast cancer risk, for which inconsistent results have been reported in the literature.
Methods: Following online database search up to January 2019, we carried out a dose-response meta-analysis to identify the relation between cadmium exposure and disease risk. We used a restricted cubic spline model and the \u2018one-stage\u2019 approach, stratifying for exposure assessment method and menopausal status.
Results: We identified 12 studies, 9 using breast cancer incidence and 3 mortality as an outcome. In six studies cadmium exposure was assessed through dietary questionnaires, in five through urinary excretion levels, and in one based on environmental air levels. Seven studies included post-menopausal women only. Overall, we observed a positive linear relation between breast cancer risk and dietary cadmium intake (relative risk (RR) 1.04, 95% confidence interval (CI) 0.81-1.33 at 10 \ub5g/day, and RR 1.12, 95% CI 0.80-1.56 at 20 \ub5g/day). On the converse, risk was not associated with urinary excretion. Analysis restricted to post-menopausal women showed a positive association between cadmium exposure assessed through either dietary intake and urinary excretion, for levels higher than 20 \ub5g/day and 1.65 \ub5g/g creatinine, respectively
El branding y posicionamiento de la empresa JP Ejecución y Elaboración de Proyectos S.A.C., Trujillo, 2022
La presente investigación tuvo como objetivo determinar la relación que existe
entre el branding y posicionamiento de la empresa JP Ejecución y Elaboración
de Proyectos S.A.C., Trujillo 2022. La investigación es de tipo aplicada, de
diseño no experimental, de nivel correlacional y con corte transversal. La
población de estudio estuvo conformada por los clientes que adquieren los
servicios de manera recurrente, obteniendo una muestra de 63 clientes a
analizar. Se aplico la técnica de encuesta y el instrumento utilizado fue un
cuestionario de 18 preguntas, el cual fue procesado por en SPSS. Se obtuvo
como resultado principal luego de aplicar el Rho de Spearman un coeficiente
de correlación de 0.790 obteniendo una relación positiva alta entre las
variables de estudio. Asimismo, se obtuvo un valor de significancia de 0.000
siendo p<0.005, el cual indica que la relación es altamente significativa, por lo
tanto, existe relación relevante entre el branding y el posicionamiento en la
empresa, esta relación es directa, es decir, a mayor branding mayor
posicionamiento
Potassium Intake and Blood Pressure: A Dose-Response Meta-Analysis of Randomized Controlled Trials
BACKGROUND: Epidemiologic studies, including trials, suggest an association between potassium intake and blood pressure (BP). However, the strength and shape of this relationship is uncertain. METHODS AND RESULTS: We performed a meta-analysis to explore the dose-response relationship between potassium supplementation and BP in randomized-controlled trials with a duration >= 4 weeks using the recently developed 1-stage cubic spline regression model. This model allows use of trials with at least 2 exposure categories. We identified 32 eligible trials. Most were conducted in adults with hypertension using a crossover design and potassium supplementation doses that ranged from 30 to 140 mmol/d. We observed a U-shaped relationship between 24-hour active and control arm differences in potassium excretion and BP levels, with weakening of the BP reduction effect above differences of 30 mmol/d and a BP increase above differences similar to 80 mmol/d. Achieved potassium excretion analysis also identified a U-shaped relationship. The BP-lowering effects of potassium supplementation were stronger in participants with hypertension and at higher levels of sodium intake. The BP increase with high potassium excretion was noted in participants with antihypertensive drug-treated hypertension but not in their untreated counterparts. CONCLUSIONS: We identified a nonlinear relationship between potassium intake and both systolic and diastolic BP, although estimates for BP effects of high potassium intakes should be interpreted with caution because of limited availability of trials. Our findings indicate an adequate intake of potassium is desirable to achieve a lower BP level but suggest excessive potassium supplementation should be avoided, particularly in specific subgroups
Sustainable sugarcane vinasse biorefinement for trans-aconitic acid-based biopolymer synthesis and bioenergy generation
This study aimed at developing a multiproduct biorefinery scheme for vinase valorization. It involved the extraction of trans-aconitic acid, its transformation into biopolymers using microwave irradiation and the use of the raffinated-vinasse for biogas production. Each technology was assessed individually, followed by a process integration at bench scale, from which a mass balance was calculated, supporting the feasibility of the approach. As a renewable source derived from a residue, these bioproducts can replace crude-oil-based materials in various chemical industrial processes; however, a detailed techno-economic and life-cycle analysis are required to defined the sustainability of the process
Reproductive output, foraging destinations, and isotopic niche of olive ridley and loggerhead sea turtles, and their hybrids, in Brazil
Hybridization is a fundamental evolutionary and ecological process with significant conservation ramifications. Sea turtle hybridization occurs at unusually high frequencies along the northeastern coast of Brazil. To better understand the process, we studied the reproductive output, migration patterns (through satellite telemetry), and isotopic niches of loggerhead turtles Caretta caretta and olive ridley turtles Lepidochelys olivacea and their hybrids. We classified 154 nesting females as loggerhead (n = 91), olive ridley (n = 38), or hybrid (n = 25) based on mitochondrial and nuclear DNA. Further, we compared nesting female morphological data and reproductive parameters (clutch size, emergence success, hatchling production, incubation period) of 405 nests among hybrids and parental species. We found no significant differences among the 3 groups when hatchling production was corrected for female body size, indicating that hybrids and parental species produce similar numbers of hatchlings per clutch. Satellite tracking of 8 post-nesting hybrid females revealed shared foraging grounds with both parental species, as well as neritic migrations between foraging and nesting areas similar to those previously reported for loggerheads and olive ridleys. Analyses of 13C and 15N isotope values (n = 69) further confirmed this pattern, as hybrid isotopic niches overlapped extensively with both parental species. Thus, given the similarities presented between hybrids and their parental species in reproductive, ecological, and behavioral characteristics, we conclude that these hybrids may persist along with other sea turtle nesting populations in the area, with research and conservation implications. © The authors 2021. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited
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