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84 resultados, página 4 de 9

Spatiotemporal analysis of rainfall and temperature variability and trends for climate resilient maize farming system in major agroecology zones of northwest Ethiopia

Kindie Tesfaye Dereje Ademe Enyew Adgo (2023, [Artículo])

Spatiotemporal studies of the annual and seasonal climate variability and trend on an agroecological spatial scale for establishing a climate-resilient maize farming system have not yet been conducted in Ethiopia. The study was carried out in three major agroecological zones in northwest Ethiopia using climate data from 1987 to 2018. The coefficient of variation (CV), precipitation concertation index (PCI), and rainfall anomaly index (RAI) were used to analyze the variability of rainfall. The Mann-Kendall test and Sen’s slope estimator were also applied to estimate trends and slopes of changes in rainfall and temperature. High-significance warming trends in the maximum and minimum temperatures were shown in the highland and lowland agroecology zones, respectively. Rainfall has also demonstrated a maximum declining trend throughout the keremt season in the highland agroecology zone. However, rainfall distribution has become more unpredictable in the Bega and Belg seasons. Climate-resilient maize agronomic activities have been determined by analyzing the onset and cessation dates and the length of the growth period (LGP). The rainy season begins between May 8 and June 3 and finishes between October 26 and November 16. The length of the growth period (LGP) during the rainy season ranges from 94 to 229 days.

Climate Trends Spatiotemporal Analysis Agroecology Zone CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA AGROECOLOGY CLIMATE CLIMATE VARIABILITY MAIZE

The past, the present, the future, and occupational self-efficacy: an attributions and cultural differences perspective

Daniel Arturo Cernas Ortiz (2023, [Artículo, Artículo])

This study´s objective was to examine empirical relationships between three dimensions of time perspective (future, present fatalistic, and past negative) and occupational self-efficacy. By surveying Mexican (n = 286) and U.S. (n = 272) respondents, we also tested the moderating role of culture. Regression analyses revealed that time perspective dimensions have significant associations with occupational self-efficacy, being future time perspective more potent than its past negative and present fatalistic counterparts. Moderation analyses indicated that none of the examined time perspective-self-efficacy relationships varied significantly between the U.S. and Mexico. Overall, this study suggests that relationships between time perspective and occupational self-efficacy vary according to different temporal dimensions, that future TP is key to develop occupational self-efficacy, and that cultural values may not exert a significant influence on the time perspective-occupational self-efficacy connection.

Perspectiva de tiempo autoeficacia diferencias culturales análisis de moderación CIENCIAS SOCIALES CIENCIAS SOCIALES Time perspective self-efficacy cultural differences moderation analysis

Deterministic Brownian-like Motion: Electronic Approach

JOSE LUIS ECHENAUSIA MONROY Eric Campos Cantón Rider Jaimes Reátegui JUAN HUGO GARCIA LOPEZ GUILLERMO HUERTA CUELLAR (2022, [Artículo])

"Brownian motion is a dynamic behavior with random changes over time (stochastic) that occurs in many vital functions related to fluid environments, stock behavior, or even renewable energy generation. In this paper, we present a circuit implementation that reproduces Brownian motion based on a fully deterministic set of differential equations. The dynamics of the electronic circuit are characterized using four well-known metrics of Brownian motion, namely: (i) Detrended Fluctuation Analysis (DFA), (ii) power law in the power spectrum, (iii) normal probability distribution, and (iv) Mean Square Displacement (MSD); where traditional Brownian motion exhibits linear time growth of the MSD, a Gaussian distribution, a −2 power law of the frequency spectrum, and DFA values close to 1.5. The obtained results show that for a certain combination of values in the deterministic model, the dynamics in the electronic circuit are consistent with the expectations for a stochastic Brownian behavior. The presented electronic circuit improves the study of Brownian behavior by eliminating the stochastic component, allowing reproducibility of the results through fully deterministic equations, and enabling the generation of physical signals (analog electronic signals) with Brownian-like properties with potential applications in fields such as medicine, economics, genetics, and communications, to name a few."

Brownian motion Deterministic Brownian motion DFA analysis Statistical analysis Electronic circuit Electronic implementation CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA