Tunneling density of states, pair correlation, and Josephson current in spin-incoherent Luttinger-liquid/superconductor hybrid systems

We study a hybrid system consisting of a spin-incoherent Luttinger liquid adjoined at one or both ends to a superconductor. We find that the tunneling density of states diverges at low energies and exhibits a universal frequency dependence independent of the strength of the interactions in the system. We show that in spite of exponentially decaying pair correlations with distance into the spin-incoherent Luttinger liquid, the Josephson current remains robust. Compared to the zero temperature Luttinger-liquid case, there is a factor of 2 reduction in the critical current and a halving of the period in the phase difference between the superconductors. We hope these results motivate a class of experiments in the spin-incoherent regime of one-dimensional systems

Irrigation and agriculture development in Africa: Impact on water quality and ecosystem health in the Ethiopian highlands

Evaluating the effect of intensification on water quality: shallow groundwater, streams, lake water bodies & biomass in the Amhara region of Ethiopia

Farmers’ Perception and Adaptation to Climate Change: Heckman’s Two Stage Sample Selection Model

No Abstrac

Cost-effectiveness analysis of clinical specialist outreach as compared to referral system in Ethiopia: an economic evaluation

BACKGROUND: In countries with scarce specialized Human resource for health, patients are usually referred. The other alternative has been mobilizing specialists, clinical specialist outreach. This study examines whether clinical specialist outreach is a cost effective way of using scarce health expertise to provide specialist care as compared to provision of such services through referral system in Ethiopia. METHODS: A cross-sectional study on four purposively selected regional hospitals and three central referral hospitals was conducted from Feb 4-24, 2009. The perspective of analysis was societal covering analytic horizon and time frame from 1 April 2007 to 31 Dec 2008. Data were collected using interview of specialists, project focal persons, patients and review of records. To ensure the propriety standards of evaluation, Ethical clearance was obtained from Jimma University. RESULTS: It was found that 532 patients were operated at outreach hospitals in 125 specialist days. The unit cost of surgical procedures was found to be ETB 4,499.43. On the other hand, if the 125 clinical specialist days were spent to serve patients referred from zonal and regional hospitals at central referral hospitals, 438 patients could have been served. And the unit cost of surgical procedures through referral would have been ETB 6,523.27 per patient. This makes clinical specialist outreach 1.45 times more cost effective way of using scarce clinical specialists' time as compared to referral system. CONCLUSION: Clinical specialist outreach is a cost effective and cost saving way of spending clinical specialists' time as compared to provision of similar services through referral system

A Quantum Theory of Cold Bosonic Atoms in Optical Lattices

Ultracold atoms in optical lattices undergo a quantum phase transition from a superfluid to a Mott insulator as the lattice potential depth is increased. We describe an approximate theory of interacting bosons in optical lattices which provides a qualitative description of both superfluid and insulator states. The theory is based on a change of variables in which the boson coherent state amplitude is replaced by an effective potential which promotes phase coherence between different number states on each lattice site. It is illustrated here by applying it to uniform and fully frustrated lattice cases, but is simple enough that it can easily be applied to spatially inhomogeneous lattice systems

Diversity, Structure and Regeneration Status of the Woodland and Riverine Vegetation of Sire Beggo in Gololcha District, Eastern Ethiopia

This study was conducted on the woodland and riverine vegetation of Sire Beggo in Gololcha District, eastern Ethiopia with the aim of documenting the floristic composition, population structure and identifying major plant community types. Preferential sampling method was employed to collect vegetation data by focusing on vegetation homogeneity. From the study sites, 70 quadrats (each measuring 20 x 20 m = 400 m2 ) were sampled. Regeneration status of woody plants was also assessed using the same quadrate size. The data on the herbaceous species were collected from five, 1 m x 1 m subplots laid at four corners each and one at the centre of the large plot. Vegetation classification was performed using TWINSPAN software package. A total of 185 plant species, representing 61 families were recorded. Fabaceae was the dominant family represented by 15 genera and 23 species, followed by Poaceae and Euphorbiaceae with 17 and 12 species each respectively. The output of TWINSPAN showed five plant community types. Structural analysis of the dominant species revealed different patterns of population structure. Some of the results of population structure and regeneration status indicated abnormal pattern which dictate the need for an urgent conservation of the study area.Keywords: Gololcha, Floristic composition, Structural analysis, Woodland, Ethiopia

Inspiration from Yewol for all of us

Five years ago, communities in the dry highlands of the Yewol mountains found it difficult to grow even their staple crops. In the rainy season, rainwater gushed down the slopes eroding the soil. Free grazing of cattle and unreliable rain affected the productivity so much that crops began to dwindle along with their livestock. Migration was the only way out for some. Food shortage stalked the residents and it still is a reality for some

Feed resources availability, utilization and marketing in central and eastern Tigray, northern Ethiopia

This survey explored the situation of different feed resources for ruminant livestock in two zones (central and eastern) in Tigray region of northern Ethiopia. These two zones account for the region’s 12% of the total land mass, 23% of the human population, 28% of the cattle population, and 56% of the small ruminant population. Farmers feed their livestock a variety of feed resources that range from crop residues to non-conventional feeds.The overall contribution of crop residues exceeds 50% of the livestock feeds currently used by smallholder farmers, and this reflects the level of integration between crop and livestock farming. Overall, the management and utilization of crop residues with particular attention to collection and transportation is constrained by factors such as labour shortage, distance from harvesting field to animals and delayed harvest in the project districts. Grazing land management and improvement is seldom considered by farmers or the extension system. Acute shortages of AIBPs supply from the sources and high price fluctuation in the main towns of the districts are discouraging smallholder dairy and small ruminant farmers from using them on a regular basis. The contribution of improved forage plants is not as expected and forage genetic material multiplication sites are operating with insufficient budget and manpower, and not supported by proper research. The overall feed supply to demand ratio in four districts in the eastern zone is not enough to cover the annual maintenance requirements of the present stock