3,173 research outputs found
Adoption and Impacts of Zero-Tillage in the Rice-Wheat Zone of Irrigated Punjab, Pakistan
This study documents the adoption and impacts of zero-tillage (ZT) wheat in the ricewheat systems of Pakistan’s Punjab province primarily drawing on a detailed empirical survey of 458 rice-wheat farmers. Our random stratified sample revealed 19% to be ZT wheat adopters and a similar share of the wheat area in the surveyed communities to be under ZT. The study suggests that diffusion has stagnated and also flags the issue of disadoption (14%). ZT adopters, non-adopters, and disadopters differ significantly in terms of their resource bases, with adopters typically showing the most favorable values. ZT drastically reduces tractor operations in farmers’ ZT wheat fields from an average of 8 passes to a single pass, implying a saving of 7 tractor hours and 35 liters of diesel per hectare. ZT did not have any significant effect on the mean farmer estimated wheat yield of 3.3 tons per hectare. ZT also had no significant effect on water productivity for wheat or spillover effect on the subsequent rice crop. ZT primarily appears to be a cost-saving technology for wheat in Pakistan’s Punjab. Based on these findings, the study provides a number of recommendations for research and development in Pakistan Punjab’s rice-wheat systems.Wheat, Rice, Agricultural development, Drilling equipment, Economic analysis, Innovation adoption, Farming systems, Cropping patterns, Production costs, Zero tillage, Pakistan, Crop Production/Industries, E16, F08,
The Socio-Economic and Demographic Determinants of Women Work Participation in Pakistan: Evidence from Bahawalpur District
The analysis of labour market participation is useful for formulating employment and human resource development policies. Females form almost more than half of the total population in Pakistan play a very important role in the country. The present study endeavors to estimate the various factors which affect the women work participation. The study is based on the cross-section data collected through field survey. The logistic regression technique is employed to estimate the determinants of female labour force participation. Educational attainment levels turn out to be very significant determinant. Female’s labour force participation rises with increasing level of education. Presence of children in early age groups reduces the female labour force participation. The results of the study conclude that female education is necessary for better employment opportunities.Female labor force participation; Female education; Household Income; Family Dependents; Marital Status; Children; Logit Model; Pakistan
Factors Affecting Cotton Production in Pakistan:Empirical Evidence from Multan District
This paper attempts to examine the factors affecting cotton production in Multan region using primary source of data. A sample of 60 small farmers, 25 medium and 15 large farmers was randomly selected from two Tehsils namely Multan and Shujabad of district Multan. The Cobb-Douglas Production Function is employed to assess the effects of various inputs like cultivation, seed and sowing, irrigation, fertilizer, plant protection, inter-culturing / hoeing and labour cost on cotton yield. The results depicted that seed, fertilizer and irrigation were found scarce commodity for all category of farmers in district Multan. The Cobb-Douglas Production Function results revealed that the coefficients for cultivation (0.113) and seed (0.103) were found statistically significant at 1 percent level. The Cost-Benefit Ratio for the large farmers was found higher (1.41) than that of small (1.22) and medium (1.24) farmers. There is a dire need to ensure the availability of these scarce inputs by both public and private sectors as these inputs were major requirement of the cotton crop.Cotton; Cobb- Douglas Production Function; Cost Benefit Ratio; Marginal Value Product; Allocate Efficiency of Critical Inputs; Multan District; Pakistan
Factors Associated within 28 Days In-Hospital Mortality of Patients with Acute Respiratory Distress Syndrome
Objective. To determine the factors leading to in-hospital mortality within 28 days in hospitalized patients with ARDS. It was a prospective observational cohort study conducted in Intensive Care Unit of Aga Khan University Hospital Karachi from March to August 2011. Methodology. Data was collected from patients admitted in the intensive care unit on the basis of inclusion and exclusion criteria. The patients were followed daily for 28 days to record any in-hospital complications and the outcome of patients. Results. Total of 46 patients were included during this period out of which 56% (26) were males and 43% (20) were females. Mean age was 44 ± 19 years. There were 11 (23.9%) patients with age \u3e65 and 35 (76%) had age \u3c65 years. There were 21 (45.6%) patients with pulmonary ARDS and 25 (54.3%) had extrapulmonary ARDS. APACHE II score of \u3e20 was present in 23 (50%) patients while the rest had score of \u3c20. Regarding in-hospital complications, 23 (50%) patients developed sepsis, 31 (67.4%) had multiorgan failure, 14 (30%) had refractory shock, and 15 (32.6%) developed refractory hypoxemia. Out of 46 patients, 26 (56.5%) died within 28 days. On univariate analysis, high APACHE score, multiorgan failure, refractory shock, and refractory hypoxemia were main causes of death. Conclusion. ARDS is a syndrome of high mortality with mortality rate of 56.5% in this study. High APACHE, sepsis, multiorgan failure, refractory shock, and refractory hypoxemia are the leading causes of death in our patients
Carotid cavernous fistula in a patient with coronary artery disease
Carotid cavernous fistulas are abnormal communications between the carotid and cavernous vasculature, with potential for serious neurological and ocular sequelae. There is considerable literature on the neuro-radiological management of carotico-cavernous fistula depending upon their flow status. The coronary artery bypass grafting (CABG) for coronary artery disease (CAD) is a well established method of revascularization. However, the association of carotid cavernous fistula in presence of CAD is an infrequent occurrence. We present a case of coronary artery disease scheduled for bypass surgery, developed spontaneous bilateral carotid cavernous fistulas, highlighting a unique aspect of association between coronary and carotid disease
Optical Asymmetric Modulation for VLC Systems
The explosive growth of connected devices and the increasing number of broadband users have led to an unprecedented growth in traffic demand. To this effect, the next generation wireless systems are envisioned to meet this growth and offer a potential data rate of 10 Gbps or more. In this context, an attractive solution to the current spectrum crunch issue is to exploit the visible light spectrum for the realization of high-speed commutation systems. However, this requires solutions to certain challenges relating to visible light communications (VLC), such as the stringent requirements of VLC-based intensity modulation and direct detection (IM/DD), which require signals to be real and unipolar. The present work proposes a novel power-domain multiplexing based optical asymmetric modulation (OAM) scheme for indoor VLC systems, which is particularly adapted to transmit high-order modulation signals using linear real and unipolar constellations that fit into the restrictions of IM/DD systems. It is shown that the proposed scheme provides improved system performance that outperforms alternative modulation schemes, at no extra complexity
Optical Non-Orthogonal Multiple Access for Visible Light Communication
The proliferation of mobile Internet and connected devices, offering a
variety of services at different levels of performance, represents a major
challenge for the fifth generation wireless networks and beyond. This requires
a paradigm shift towards the development of key enabling techniques for the
next generation wireless networks. In this respect, visible light communication
(VLC) has recently emerged as a new communication paradigm that is capable of
providing ubiquitous connectivity by complementing radio frequency
communications. One of the main challenges of VLC systems, however, is the low
modulation bandwidth of the light-emitting-diodes, which is in the megahertz
range. This article presents a promising technology, referred to as "optical-
non-orthogonal multiple access (O-NOMA)", which is envisioned to address the
key challenges in the next generation of wireless networks. We provide a
detailed overview and analysis of the state-of-the-art integration of O-NOMA in
VLC networks. Furthermore, we provide insights on the potential opportunities
and challenges as well as some open research problems that are envisioned to
pave the way for the future design and implementation of O-NOMA in VLC systems
Energy Content of Colliding Plane Waves using Approximate Noether Symmetries
This paper is devoted to study the energy content of colliding plane waves
using approximate Noether symmetries. For this purpose, we use approximate Lie
symmetry method of Lagrangian for differential equations. We formulate the
first-order perturbed Lagrangian for colliding plane electromagnetic and
gravitational waves. It is shown that in both cases, there does not existComment: 18 pages, accepted for publication in Brazilian J Physic
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