Analiza kretanja rasta proizvodnje poljoprivrednih kultura u Nigeriji (1961. –2014.)

This paper focuses on trend analysis of crop productivity growth in Nigeria between 1961 and 2014. It was therefore intended to estimate the effect of different factors of production that influence crop output and to compute their technical efficiency, technological change and total factor productivity change. Panel data was broken into land, labour, tractor, fertilizer and animal power. Descriptive statistics, Cobb-Douglas production analysis and Malmquist Productivity index were the tools employed for the analysis. The result of the trend analysis shows that time has a positive effect on crop production and also shows that there is an increase in crop output, land, labour, tractor, fertilizer and animal power over years. Land and animal power are statistically significant at 1% probability level and a unit increase in land and animal power, crop output increases by 2.176772 tons and 0.7531192 tons respectively, this implies that land and animal power have a positive effect on crop output in Nigeria. Labour and tractor have negative impact on crop output, while fertilizer has no significant effect on crop output. The efficiency change, technical change and total factor productivity change were also analyzed. According to the analysis, Nigeria experienced the highest agricultural productivity from 1992, with value of 1.166. It is therefore recommended that the use of agricultural land should be increased, relevant policies should address the constraints to technology progress, and efficiency should be promoted in order to improve productivity growth.Ovaj je rad usredotočen na analizu kretanja rasta proizvodnje poljoprivrednih kultura u Nigeriji u razdoblju od 1961. do 2014. Cilj je ovog rada odrediti kako različiti faktori proizvodnje utječu na količinu proizvedenih kultura te izmjeriti njihovu tehničku učinkovitost, tehnološki razvoj i promjene u ukupnom faktoru produktivnosti. Panel podaci razdijeljeni su u sljedeće kategorije: zemljište, radna snaga, traktori, gnojivo i životinjska snaga (radne životinje). Za potrebe analize korištena je deskriptivna statistika, Cobb-Douglasova proizvodna funkcija i Malmquistov indeks produktivnosti. Dobiveni rezultati pokazuju da vrijeme ima pozitivan učinak na proizvodnju poljoprivrednih kultura te da je tijekom godina zamjetan porast u količini proizvedenih kultura, zemljištu, radnoj snazi, traktorima, gnojivu i životinjskoj snazi. Zemljište i životinjske snaga statistički su značajne kategorije, s razinom vjerojatnosti od 1 %. Porast jedinice zemljišta rezultira porastom od 2,176.772 tona u poljoprivrednim kulturama, a životinjske snage porastom od 0,7531192 tona u poljoprivrednim kulturama. Iz ovoga proizlazi da zemljište i životinjska snaga imaju pozitivan utjecaj na količinu proizvedenih poljoprivrednih kultura u Nigeriji. Kategorije radne snage i traktora imaju negativan učinak, a gnojiva nemaju nikakav značajni učinak na količinu proizvedenih poljoprivrednih kultura. Mjerena je i tehnička učinkovitost te tehnološki razvoj i promjene u ukupnom faktoru produktivnosti. Prema dobivenim rezultatima, poljoprivredna je proizvodnja u Nigeriji 1992. dosegla svoju najveću vrijednost od 1,166. S obzirom na rezultate preporučuje za povećanje poljoprivrednog zemljišta i učinkovitosti te donošenje relevantnih mjera čiji bi cilj bio rješavanje problematike razvoja tehnologije

Multinomial Logit Estimation of Income Sources by Watermelon Farmers in Northeastern Nigeria

The main objective of the research was to use multinomial logit model to estimate income sources of watermelon farmers in northeastern Nigeria. A total of 434 farmers were sampled through multi-stage sampling procedure covering three Local Government Areas of Yobe state, Nigeria. The sources were personal savings, friends and relatives, Bank loans and cooperative/thrift societies. The results revealed that farm size, age and level of education were significant at 5% probability level and positively influenced the utilization of income from friends and relatives. Farmers' level of education, total cost of production and farm size significantly influenced farmers to obtain loans from banks. The marginal effects were 0.0504, 2.75 and 0.0038 showing the degrees of probabilities the variables can influence bank loans. Watermelon farmers can only obtain loans from cooperative and thrift society based on their farm size, total revenue, age, total cost and their level of output. These variables were significant at 1% and 5% probability levels with appropriate signs. The study concluded that 60% of the farmers fund their farm through personal savings and was difficult to get bank loans. It was recommended that micro-savings be encouraged among farmers and cooperative/thrift societies should be encouraged and adequately developed through the Non-Governmental Organizations

Utjecaj klimatskih promjena na proizvodnju riže u Adamawi, Nigerija

This study analyzes the effect of climate change on rice production in Adamawa State, Nigeria. The study describes the trend in rice production and determines the factors affecting the output of rice in Adamawa. Secondary data from 1990-2015 was used. The analytical tools used were descriptive analysis, unit root and regression analysis. The result of the study reveals that there is variation in the trend of the climatic factors affecting rice production in Adamawa State. The findings reveal that rainfall and minimum temperature are the major climatic factors that affect the rice production; such that 1% increase in rainfall leads to 22.2% increase in rice production and 1% increase in minimum temperature leads to 3.7% reduction in rice production. Therefore rainfall is found to be positively significant to rice output, while minimum temperature is found to be negatively significant. The study therefore recommends that irrigation facilities should be built, especially in the north where drought threatens food production. Also breeders should develop rice varieties that have less gestation period and can survive high temperature.Ovaj se rad bavi utjecajem klimatskih promjena na proizvodnju riže u Adamawi, Nigerija. Opisuju se trendovi rasta i pada proizvodnje te određuju faktori koji utječu na količinu proizvedene riže. Istraživanje se temelji na sekundarnim podacima iz razdoblja od 1990. do 2015. Za analizu su korištene sljedeće metode: deskriptivna analiza, test jediničnog korijena i regresijska analiza. Rezultati dobiveni istraživanjem pokazuju da klimatski faktori utječu na proizvodnju riže u Adamawi, a kao glavni među njima ističu se količina padalina i minimalna temperatura: porast u količini padalina od 1 % rezultira porastom u proizvodnji riže od 22.2 %, a porast minimalne temperature od 1 % rezultira padom u proizvodnji riže od 3.7 %. Iz toga se može zaključiti da postoji pozitivna korelacija između količine padalina i količine proizvedene križe te negativna korelacija s obzirom na minimalnu temperaturu. S obzirom na dobivene rezultate preporučuje se izgradnja objekata za navodnjavanje, osobito na sjeveru gdje su sušna razdoblja prijetnja proizvodnji hrane. Također, uzgajivačima se preporuča razvoj vrsta riže koje imaju kraći gestacijski period te mogu preživjeti više temperature

Pressure-dependent EPANET extension

In water distribution systems (WDSs), the available flow at a demand node is dependent on the pressure at that node. When a network is lacking in pressure, not all consumer demands will be met in full. In this context, the assumption that all demands are fully satisfied regardless of the pressure in the system becomes unreasonable and represents the main limitation of the conventional demand driven analysis (DDA) approach to WDS modelling. A realistic depiction of the network performance can only be attained by considering demands to be pressure dependent. This paper presents an extension of the renowned DDA based hydraulic simulator EPANET 2 to incorporate pressure-dependent demands. This extension is termed “EPANET-PDX” (pressure-dependent extension) herein. The utilization of a continuous nodal pressure-flow function coupled with a line search and backtracking procedure greatly enhance the algorithm’s convergence rate and robustness. Simulations of real life networks consisting of multiple sources, pipes, valves and pumps were successfully executed and results are presented herein. Excellent modelling performance was achieved for analysing both normal and pressure deficient conditions of the WDSs. Detailed computational efficiency results of EPANET-PDX with reference to EPANET 2 are included as well

Penalty-free feasibility boundary convergent multi-objective evolutionary algorithm for the optimization of water distribution systems

This paper presents a new penalty-free multi-objective evolutionary approach (PFMOEA) for the optimization of water distribution systems (WDSs). The proposed approach utilizes pressure dependent analysis (PDA) to develop a multi-objective evolutionary search. PDA is able to simulate both normal and pressure deficient networks and provides the means to accurately and rapidly identify the feasible region of the solution space, effectively locating global or near global optimal solutions along its active constraint boundary. The significant advantage of this method over previous methods is that it eliminates the need for ad-hoc penalty functions, additional “boundary search” parameters, or special constraint handling procedures. Conceptually, the approach is downright straightforward and probably the simplest hitherto. The PFMOEA has been applied to several WDS benchmarks and its performance examined. It is demonstrated that the approach is highly robust and efficient in locating optimal solutions. Superior results in terms of the initial network construction cost and number of hydraulic simulations required were obtained. The improvements are demonstrated through comparisons with previously published solutions from the literature

Informational entropy : a failure tolerance and reliability surrogate for water distribution networks

Evolutionary algorithms are used widely in optimization studies on water distribution networks. The optimization algorithms use simulation models that analyse the networks under various operating conditions. The solution process typically involves cost minimization along with reliability constraints that ensure reasonably satisfactory performance under abnormal operating conditions also. Flow entropy has been employed previously as a surrogate reliability measure. While a body of work exists for a single operating condition under steady state conditions, the effectiveness of flow entropy for systems with multiple operating conditions has received very little attention. This paper describes a multi-objective genetic algorithm that maximizes the flow entropy under multiple operating conditions for any given network. The new methodology proposed is consistent with the maximum entropy formalism that requires active consideration of all the relevant information. Furthermore, an alternative but equivalent flow entropy model that emphasizes the relative uniformity of the nodal demands is described. The flow entropy of water distribution networks under multiple operating conditions is discussed with reference to the joint entropy of multiple probability spaces, which provides the theoretical foundation for the optimization methodology proposed. Besides the rationale, results are included that show that the most robust or failure-tolerant solutions are achieved by maximizing the sum of the entropies

DAF-16 and Δ9 Desaturase Genes Promote Cold Tolerance in Long-Lived Caenorhabditis elegans age-1 Mutants

In Caenorhabditis elegans, mutants of the conserved insulin/IGF-1 signalling (IIS) pathway are long-lived and stress resistant due to the altered expression of DAF-16 target genes such as those involved in cellular defence and metabolism. The three Δ9 desaturase genes, fat-5, fat-6 and fat-7, are included amongst these DAF-16 targets, and it is well established that Δ9 desaturase enzymes play an important role in survival at low temperatures. However, no assessment of cold tolerance has previously been reported for IIS mutants. We demonstrate that long-lived age-1(hx546) mutants are remarkably resilient to low temperature stress relative to wild type worms, and that this is dependent upon daf-16. We also show that cold tolerance following direct transfer to low temperatures is increased in wild type worms during the facultative, daf-16 dependent, dauer stage. Although the cold tolerant phenotype of age-1(hx546) mutants is predominantly due to the Δ9 desaturase genes, additional transcriptional targets of DAF-16 are also involved. Surprisingly, survival of wild type adults following a rapid temperature decline is not dependent upon functional daf-16, and cellular distributions of a DAF-16::GFP fusion protein indicate that DAF-16 is not activated during low temperature stress. This suggests that cold-induced physiological defences are not specifically regulated by the IIS pathway and DAF-16, but expression of DAF-16 target genes in IIS mutants and dauers is sufficient to promote cross tolerance to low temperatures in addition to other forms of stress

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens