Search results for " Fertility."
showing 10 items of 130 documents
Impacts of land‐use changes on soil fertility in Okomu Forest Reserve, Southern Nigeria
2021
Modeling soil cation exchange capacity in multiple countries
2017
Abstract Cation exchange capacity (CEC), as an important indicator for soil quality, represents soil's ability to hold positively charged ions. We attempted to predict CEC using different statistical methods including monotone analysis of variance (MONANOVA), artificial neural networks (ANNs), principal components regressions (PCR), and particle swarm optimization (PSO) in order to compare the utility of these approaches and identify the best predictor. We analyzed 170 soil samples from four different nations (USA, Spain, Iran and Iraq) under three land uses (agriculture, pasture, and forest). Seventy percent of the samples (120 samples) were selected as the calibration set and the remainin…
THE IMPACT OF FIRE ON REDISTRIBUTION OF SOIL ORGANIC MATTER ON A MEDITERRANEAN HILLSLOPE UNDER MAQUIA VEGETATION TYPE
2010
Soil organic matter (SOM) changes affect the CO2 atmospheric levels and is a key factor on soil fertility and soil erodibility. Fire affects ecosystems and the soil properties due to heating and post-fire soil erosion and degradation processes. In order to understand fire effects on soil organic carbon (SOC) balance research was undertaken on a fire-prone ecosystem: the Mediterranean maquia. The spatial distribution of SOC was measured in a Burnt site 6 months after a wildfire and in a Control site. Samples were collected at two different depths (0–3 and 3–10 cm) and SOC was determined. The results show that 41·8 per cent of the SOC stock was lost. This is due to the removal of the burnt ma…
Distribution of soil organic carbon in Wadi Al-Thulaima, Saudi Arabia: A hyper-arid habitat altered by wastewater reuse
2018
The carbon cycle is being altered as a result of human-induced changes in the Earth's system. Therefore, ecosystems such as wetlands, authentic CO2 sinks, are becoming especially important. Little information exits on the soil organic carbon (SOC) stock for the middle east-countries man-made wetlands making wadis permanent with the outflow of wastewater treatment plants. This paper presents the vertical distribution of SOC content, soil bulk density (SBD) and SOC density in soil of vegetated and bare sites in Wadi Al-Thulaima, one of the artificial wetlands in central Saudi Arabia. The mean distribution of SBD in the vegetated and bare sites increased significantly with depth. Inversely, th…
A comprehensive use of ultrasound examination in infertility workup
2021
Considering the growing availability of ultrasound diagnostic methods in gynecology, its role in the infertility setting is increasing. In this review, we present an up-to-date ultrasound based diagnostic scheme in infertility workup comprising the evaluation of ovarian anatomy and function, uterine exploration, as well as tubal patency. The possibility of performing the vast majority of infertility diagnostics by ultrasound in the ambulatory settings is not only attractive and beneficial to patients, but also to health care system. Thus, it is vital for gynecologists to implement modern non-invasive ultrasound modalities in their everyday practice.
Effect of biochar on the physical and structural properties of a sandy soil
2019
Abstract Biochar application to soil can be considered as a means to improve soil quality, thereby optimizing irrigation management and reducing irrigation needs, especially in dryland regions. This paper is aimed at investigating the effect of biochar (BC) on a desert sandy soil (Al Foah, United Arab Emirates) in terms of bulk density, porosity, water retention, plant available water (AWmax), aggregate stability (AS) and specific surface area (BET-SSA). BC was produced from forest biomass (Italy). Soil water retention was measured by the High Energy Moisture Characteristic (HEMC) and by pressure plate measurements, by using BC fractions equal to 0 (soil only), 0.014, 0.091, 0.23, 0.33 and …
ESCOLARIZACIÓN, TRABAJO INFANTIL Y SATISFACCIÓN LABORAL: EVIDENCIA PARA ETIOPÍA
2012
En ligne sur http://www.staragon.com/revecap/revista/numeros/58/pdf/gamero_lassibille.pdf; International audience; Tomando como referencia Etiopía, este artículo investiga, en el marco de un modelo probit bivariante, cuáles son los factores que influyen en las probabilidades de que un niño trabaje o siga escolarizado. Los resultados muestran que el trabajo infantil desplaza efectivamente a la demanda de educación y sugieren que prohibir el trabajo infantil, para romper la competencia que se ejerce entre la educación y el empleo, podría perpetuar el nivel de pobreza de las generaciones futuras. Por otro lado, se analizan los factores de los que depende su satisfacción laboral, poniendo espec…
LOW FERTILITY AND POLICY RESPONSES IN SOME DEVELOPED COUNTRIES WITH SPECIAL REFERENCE TO EUROPE
2003
Pension Schemes and Falling Birth-Rates: Change in Customs or Microeconomic Optimization?
2004
In this paper, we develop an overlapping generations model where fertility is endogenous. The utility of the parents is a function of the number of their children, and each child implies two types of fixed costs: the financial cost and the cost in terms of time. A "pay-as-you-go" pension scheme introduces an externality in that the number of children will be fewer than optimal because their favorable impact on the level of pension income is not taken into account. First, we define the competitive equilibrium dynamics and the steady state. This allows comparisons with the optimal stationary state, a notion which generalizes the golden rule. Two instruments, pensions and child benefits, are n…
The effect of women’s participation in the labour market on the postponement of first childbirth: a comparison of Italy and Hungary
2014
This paper analyses the effect of increasing female participation in the labour market on the transition to first childbirth. Regional perspectives are considered to help us understand how postponement behaviour is changing over time and at different paces in each region. The analysis is based on the first wave of the Generations and Gender Survey of Italy and Hungary. We use a multilevel event history random intercept model to examine the effect of individuals’ positions in the labour market on the transition to motherhood, controlling for differences in macrolevel factors related to regional backgrounds in the two countries. The regional data for Italy came from the Italian National Stati…