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النتائج 331 - 340 من 372
Synergies evaluation and influencing factors analysis of the water–energy–food nexus from symbiosis perspective: A case study in the Beijing–Tianjin–Hebei region النص الكامل
2022
Wang, Yong | Xie, Yanjing | Qi, Lin | He, Yuan | Bo, He
In the context of global population growth and environmental degradation, research on the synergies of the water–energy–food (WEF) nexus is important for sustainable regional development. Using symbiosis and synergy theories, the authors constructed a synergy evaluation index for the WEF nexus and used the set pair analysis-variable fuzzy sets model to analyze the WEF nexus synergies in the Beijing–Tianjin–Hebei region (BTH) of China, from 2005 to 2017. The main factors affecting WEF nexus synergies were also analyzed, with results indicating that: 1) the WEF nexus synergies were the best in Beijing, followed by the BTH as a whole, Tianjin, and then Hebei. We also found that WEF nexus synergy grades have been gradually improving over time, with Beijing improving the most, and Tianjin the least. 2) The WEF nexus synergy grades in each region, for symbiotic units, symbiotic relationships, and symbiotic environments, have also gradually improved. And symbiotic relationship synergies were better than symbiotic environment synergies than symbiotic unit synergies. 3) The WEF nexus symbiotic unit synergies were strongest in Tianjin, followed by Beijing, the BTH as a whole, and then Hebei. The symbiotic relationship synergies were strongest in Beijing, followed by Hebei, the BTH as a whole, and then Tianjin. The symbiotic environment synergies were also strongest in Beijing, followed this time by the BTH as a whole, Tianjin, and then Hebei. 4) Economic factors and symbiotic unit synergies were found to be the aspects most influential on WEF nexus synergies in each region. In addition, symbiotic relationship synergies were found to have important impacts on the WEF nexus synergies in Hebei and the BTH as a whole. Overall, we were able to conclude that the methodology developed in this study provided a scientific basis for synergy optimization in the context of a regional WEF nexus.
اظهر المزيد [+] اقل [-]Studies of Food Ecology of Great Cormorant Phalacrocorax carbo in Relation to Water Transparency Require System-Adjusted Data: An Example from Two Polish Reservoirs النص الكامل
2022
Gwiazda, Robert | Flis, Adam
Water transparency is an important factor affecting fish availability (underwater visibility) for diving birds. The diet of Great Cormorants Phalacrocorax carbo in relation to water transparency (range 1.4–4.0 m) was studied by pellet analyses at the submontane reservoir Dobczyce, Poland, from June to November. Although water transparency proved to be related to the birds' distribution, in the range of turbidities studied, no relationship was found with either fish species and fish size taken. Of 14 species in the diet, Roach Rutilus rutilus was dominant in all monthly samples (35–91% in 2002, 56–82% in 2004). Numbers of Great Cormorants and water transparency (range 0.4–1.4 m) were studied in the turbid lowland reservoir Goczałkowice during the migration period in autumn (August–November 2011 and 2012). Observations here suggest that the effect of water transparency on food uptake and habitat choice was only apparent below 0.6 m Secchi depth. The number of foraging Great Cormorants was not only affected by Secchi depth, but by a complex of factors (year, month, place, Secchi depth and water depth). We argue that, especially when the number of Great Cormorants is low, only highly detailed measurements of these factors (both spatially and as time series) can show the complex relationship between prey distribution, environmental conditions and the predator's behaviour.
اظهر المزيد [+] اقل [-]An integrative analytical framework of water-energy-food security for sustainable development at the country scale: A case study of five Central Asian countries النص الكامل
2022
Hao, Lingang | Wang, Ping | Yu, Jingjie | Ruan, Hongwei
Thoroughly understanding the security of water, energy and food (WEF) and the factors that influence them is essential for sustainable development management in any region. This study proposed a new analytical framework for WEF security evaluation in both individual sectors and the whole system, using the technique for order preference by similarity to an ideal solution (TOPSIS) and four dimensions of security indicators: availability, self-sufficiency, productivity and accessibility. The internal relationships among the three sectors and the main factors influencing WEF security were analysed by Spearman’s rank correlation and radar graphs, respectively. The five countries in Central Asia (CA), which are experiencing WEF crises and facing great challenges in achieving their sustainable development goals (SDGs), were chosen as a case study in this paper. Our results showed that Kazakhstan attained the highest WEF security level, followed by Kyrgyzstan, Turkmenistan and Uzbekistan; Tajikistan exhibited the lowest security level from 2000 to 2014. Three types of internal relationships among the three sectors were identified: synergies, trade-offs and unclassified. The unclassified relationship type accounted for the largest share of 54% in CA, suggesting great potential for synergetic improvement among the three sectors. Approaches for improving the country WEF security based on our research are as follows: Kazakhstan should prioritize food allocation and supply, Kyrgyzstan and Tajikistan should increase energy and food production and raise the supply level and usage efficiency of water and food, Turkmenistan should increase the available water resources and food production and improve the supply level and usage efficiency of water and energy, and Uzbekistan should both increase the available amount and enhance the WEF management performance.
اظهر المزيد [+] اقل [-]Development of natural deep eutectic solvents (NADESs) as anti-freezing agents for the frozen food industry: Water-tailoring effects, anti-freezing mechanisms and applications النص الكامل
2022
Tian, You | Sun, Da-Wen | Zhu, Zhiwei
Nature-inspired natural deep eutectic solvents (NADESs) as anti-freezing agents including Pro:Glc (5:3), Pro:Glc (1:1), Pro:Sor (1:1), and Urea:Glc:CaCl₂ (3:6:1) were prepared. Viscosity (η), conductivity (σ), activation energy of viscous flow (Eη) and conduction (Eᴧ), transverse relaxation time (T₂), thermal behaviours, and anti-freezing capacities of the NADESs were investigated. A critical T₂ of 24.60 ms for η changes was obtained, and the relationship between η and T₂ was determined as lnη = -1.398lnT₂ + 10.688. Differentialscanningcalorimetry and low-field nuclear magnetic resonance analyses indicated NADESs could hinder the molecular motion as temperature decreased through enhancing the hydrogen-bonding strength, endowing them with excellent anti-freezing capacity. NADESs showed varied Eη (41.58 ∼ 45.72 kJ mol⁻¹) and Eᴧ (48.31 ∼ 63.08 kJ mol⁻¹), of which Pro:Sor (1:1) possessed the greatest ones, showing its greatest temperature sensitivity and best anti-frosting capacity. Applications in frozen chicken breast further announced the potentials of NADESs as anti-freezing agents for the industry.
اظهر المزيد [+] اقل [-]Bacterial Communities and Antibiotic Resistance of Potential Pathogens Involved in Food Safety and Public Health in Fish and Water of Lake Karla, Thessaly, Greece النص الكامل
2022
Dimitrios A. Anagnostopoulos | Foteini F. Parlapani | Stamatia Natoudi | Faidra Syropoulou | Maria Kyritsi | Ioannis Vergos | Christos Hadjichristodoulou | Ifigenia Kagalou | Ioannis S. Boziaris
Bacterial communities, microbial populations, and antibiotic resistance of potential pathogens in the water and fish (Cyprinus carpio, flesh and gut) from different areas (A1, A2 and A3&mdash:A1 was linked with river water, A2 with cattle activity, and A3 with waters of a spring after heavy rains) of Lake Karla (Thessaly, Central Greece) were investigated. The isolated bacteria were identified using Matrix-assisted laser desorption ionization&ndash:time of flight mass spectrometry (MALDI-TOF MS) and were tested for resistance in 21 antibiotics. The microbiota composition of fish flesh was also studied using 16S amplicon-based sequencing Serratia fonticola and several species of Aeromonas (e.g., Aeromonas salmonicida, Aeromonas bestiarium, Aeromonas veronii, etc.) exhibited the highest abundances in all studied samples, while the microbiota profile between the three studied areas was similar, according to the culture-dependent analysis. Of them, S. fonticola was found to be resistant in the majority of the antibiotics for the water and fish (gut and flesh), mainly of the areas A1 and A2. Regarding 16S metabarcoding, the presence of Serratia and Aeromonas at genus level was confirmed, but they found at very lower abundances than those reported using the culture-dependent analysis. Finally, the TVC and the rest of the studied microbiological parameters were found at acceptable levels (4 log cfu/mL or cfu/g and 2&ndash:4 log cfu/mL or cfu/g, extremely low levels of E. coli/coliforms) in both water and fish flesh. Based on our findings, the water of Lake Karla would be used for activities such as irrigation, recreation and fishing, however, the development and implementation of a quality management tool for Lake Karla, to ensure environmental hygiene and prevention of zoonosis during the whole year, is imperative.
اظهر المزيد [+] اقل [-]Estrés por calor en ganado lechero con énfasis en la producción de leche y los hábitos de consumo de alimento y agua. Revisión النص الكامل
2022
Correa-Calderón,Abelardo | Avendaño-Reyes,Leonel | López-Baca,M. Ángeles | Macías-Cruz,Ulises
Resumen El impacto negativo del estrés por calor (EC) en la ganadería lechera repercute en cuantiosas pérdidas económicas a nivel mundial, dado que reduce la producción de leche, la eficiencia reproductiva y la vida productiva de las vacas. Adicionalmente, el mejoramiento genético continuo resulta en vacas muy productivas, pero menos tolerantes al EC debido a que producen mayor calor metabólico. Esto en conjunto con el calentamiento global convertirá al EC en un reto difícil de controlar para la industria lechera. Como respuesta dependiente del grado de EC, el ganado lechero realiza una serie de ajustes fisiológicos, metabólicos y conductuales como mecanismos de termorregulación para disipar el exceso de calor corporal y reducir la producción endógena del mismo, todo dirigido a mantener la normotermia. Sin embargo, la secreción láctea y la fertilidad se reducen por efecto directo de la hipertermia e indirectamente por la reducción en el consumo de nutrientes dietéticos. Los consumos de alimento y de agua están asociados estrechamente con la reducción de la productividad en ganado lechero expuesto a EC. Cabe mencionar que el impacto del EC en la productividad del ganado lechero varía entre razas, siendo las razas Bos taurus menos tolerantes al EC, particularmente la raza Holstein. Actualmente, se investiga en la identificación de genes asociados con la termotolerancia, los cuales son empleados en programas de selección por marcadores genéticos para producir vacas altas productoras de leche en climas cálidos. Por lo tanto, el objetivo de esta revisión es hacer un análisis comprensivo de los efectos del EC sobre la producción de leche, activación de mecanismos de termorregulación y conducta de ingesta en ganado lechero.
اظهر المزيد [+] اقل [-]Estrés por calor en ganado lechero con énfasis en la producción de leche y los hábitos de consumo de alimento y agua. Revisión النص الكامل
2022
Abelardo Correa-Calderón | Leonel Avendaño-Reyes | M. Ángeles López-Baca | Ulises Macías-Cruz
El impacto negativo del estrés por calor (EC) en la ganadería lechera repercute en cuantiosas pérdidas económicas a nivel mundial, dado que reduce la producción de leche, la eficiencia reproductiva y la vida productiva de las vacas. Adicionalmente, el mejoramiento genético continuo resulta en vacas muy productivas, pero menos tolerantes al EC debido a que producen mayor calor metabólico. Esto en conjunto con el calentamiento global convertirá al EC en un reto difícil de controlar para la industria lechera. Como respuesta dependiente del grado de EC, el ganado lechero realiza una serie de ajustes fisiológicos, metabólicos y conductuales como mecanismos de termorregulación para disipar el exceso de calor corporal y reducir la producción endógena del mismo, todo dirigido a mantener la normotermia. Sin embargo, la secreción láctea y la fertilidad se reducen por efecto directo de la hipertermia e indirectamente por la reducción en el consumo de nutrientes dietéticos. Los consumos de alimento y de agua están asociados estrechamente con la reducción de la productividad en ganado lechero expuesto a EC. Cabe mencionar que el impacto del EC en la productividad del ganado lechero varía entre razas, siendo las razas Bos taurus menos tolerantes al EC, particularmente la raza Holstein. Actualmente, se investiga en la identificación de genes asociados con la termotolerancia, los cuales son empleados en programas de selección por marcadores genéticos para producir vacas altas productoras de leche en climas cálidos. Por lo tanto, el objetivo de esta revisión es hacer un análisis comprensivo de los efectos del EC sobre la producción de leche, activación de mecanismos de termorregulación y conducta de ingesta en ganado lechero.
اظهر المزيد [+] اقل [-]Visión crítica de la relación del agua, la energía y los alimentos bajo el enfoque de los derechos humanos en México, 2011- 2020 النص الكامل
2022
Rivera de La Rosa, José de Jesús | Arrieta Martínez, Elisa
"Para entender la relación del agua, la energía y los alimentos bajo el enfoque de los derechos humanos en México durante el periodo 2011-2020; y su vinculación con temas de seguridad y soberanía; resulta de ayuda el enfoque del NAEA. En esta tesis se desglosan los elementos teóricos que lo conforman, ya que cada uno de ellos tuvo un proceso diferente de reconocimiento en la jurisdicción internacional y su conciliación con el marco jurídico nacional para la protección de la soberanía y el resguardo de diversos temas de seguridad, debido a que cada nación responde en relación a la posición geopolítica que tiene en el mundo, en el caso particular de México, al ser un territorio con abundantes recursos hídricos y naturales se ha utilizado un desarrollo extractivista y de base industrial para el país". | Área Económico Administrativa | Facultad de Economía | Maestría en Desarrollo Económico y Cooperación Internacional | generalPublic | Maestro(a) en Desarrollo Económico y Cooperación Internacional
اظهر المزيد [+] اقل [-]Optimization of magnetic ionic based dispersive liquid-liquid microextraction of cadmium in water and food samples using experimental design prior to flame atomic absorption spectrophotometry النص الكامل
2022
Elik, Adil | Altunay, Nail
A magnetic ionic based dispersive liquid liquid microextraction (MIL-DLLME) procedure was optimized for the analysis and extraction of cadmium in water and food samples by flame atomic absorption spectrophotometry (FAAS). Contribution of experimental variables were optimized through central composite design combined with response surface analysis. Under optimized conditions, the limit of detection was found 0.6 ng mL⁻¹ with the relative standard deviation of 1.7%. Dynamic range was obtained in the concentration range of 2–700 ng mL⁻¹ with correlation coefficient of 0.9983. Relative recoveries were ranged from 94% to 99% with enrichment factor of 172. The validation of the optimized method was successfully confirmed by reference material analysis. The optimized method allows the analysis of cadmium in water and food samples with good reliability of the determination. Compared with the conventional procedures, the method enabled a fast, green and simple determination of cadmium in the real sample with minimal solvent consumption and a higher extraction capability.
اظهر المزيد [+] اقل [-]Cloud point extraction coupled with back-extraction for speciation of inorganic vanadium in water and determination of total vanadium in food samples by ICP-OES النص الكامل
2022
Mortada, Wael I. | El-Defrawy, Mohamed M. | Erfan, Eman | El-Asmy, Hala A.
A preconcentration procedure based on cloud point extraction and back-extraction (CPE-BE) was proposed for speciation of inorganic vanadium (V⁴⁺ and V⁵⁺) followed by determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). Two consecutive steps are used in this technique. The traditional CPE technique was applied as a first step, V⁵⁺ reacts with bis(3,4-dihydroxybenzylidene)isophthalohydrazide (DHBIP) forming a hydrophobic complex at pH 7.0. The formed complex is then entrapped in a surfactant-rich phase of Triton X-114, while V⁴⁺ kept in the aqueous phase. Following this stage, a back-extraction step was performed to minimize the deteriorating effect of the organic matrix on the plasma performance. For this purpose, the surfactant-rich phase containing the analyte was incubated at 45 °C with 1.0 mL of 1.0 mol L⁻¹ of HNO₃ solution for 15 min. Finally, the analyte in the aqueous phase was determined by ICP-OES. The total vanadium was determined as V⁵⁺ after oxidation of V⁴⁺ by using hydrogen peroxide. The calibration graph is linear from 0.4–750.0 μg L⁻¹ for V⁵⁺ at the optimum conditions (pH 7.0, 10⁻⁴ mol L⁻¹ DHBIP, 0.1 % (v/v) Triton X-114 and 45 °C). The detection and quantification limits of V⁵⁺ were 0.12 μg L⁻¹and 0.40 μg L⁻¹, respectively, with an enrichment factor of 49.5, and the relative standard deviation was less than 2.5 % (n = 7, c = 10 μg L⁻¹). The method has been used for speciation of inorganic V in water samples and determination of total V in cabbage, carrots, mint, and tomato samples with satisfactory results.
اظهر المزيد [+] اقل [-]