Appearance Potential Spectroscopy of Solid Surfaces

Among the techniques utilized for the study of unfilled density of states above the Fermi level in a system, appearance potential spectroscopy (APS) has emerged as one of the simplest. Some review papers on APS have appeared in the last decade. Since then APS has been applied to several interesting systems, the studies of which have been limited by other experimental techniques available. This paper reviews some of these applications of APS. We discuss briefly the one-electron theory describing the APS process and outline the basic experimental set-ups used by workers in this field. We then survey some important applications of this technique to simple, as well as, multi-component systems. The results of the applications cited are compared with those from other techniques wherever available. The electronic structure of transition metals, rare earths and their intermetallics as obtained from APS spectra are discussed. The phenomena of adsorption and fine structure which are dependent on the surface sensitivity of APS are also dealt with by including some interesting applications. Finally, we take into account the strengths and limitations of this technique and outline the prospects of this spectroscopy in attaining its importance among the various surface spectroscopies

Anatomical variations and bilateral symmetry of roots and root canal system of mandibular first permanent molars in Saudi Arabian population utilizing cone- beam computed tomography

Aim: The aim of the study was to evaluate the anatomical variations of the roots and root canal system, and to determine the symmetry between right and left sides of mandibular first permanent molars in Saudi Arabian population using images derived from cone beam computed tomography (CBCT) scans. Methods: The CBCT scans (with the following parameters: FOV 170 × 120 mm, 90 Kv, 5–8 mA, 17.5 s exposure time and 0.25 mm voxel size) were retrieved from the database and axial, coronal and sagittal sections of mandibular first molars were examined. The number of roots, canals and type of canal configuration based on Vertucci's classification were recorded. Bilateral symmetry between right and left side of the same individuals and differences between genders were investigated. Results: Out of 174 mandibular first molars, 97.1% were two rooted and 2.9% were three rooted (distolingual root). In regards to the number of canals, 73% had three, 25.3% had four and 1.7% had two root canals. In teeth with four root canals, 90.9% of the extra canal was in the distal root, while 9.1% in the extra distolingual root. The most common canal configuration in mesial and distal root were type IV (64.9%) and type I (77%), respectively. Symmetrical analysis revealed 100% symmetry in number of roots and 56.4% in number of canals between right and left teeth in the same individual. Conclusions: Within the limitation of this study, wide range of canals configurations were noted in mandibular first molars among the Saudi Arabian population. The prevalence of three rooted mandibular first molars was relatively low. Three canals were most commonly seen in mandibular first molars. Bilateral symmetry was varied in number of canals and canals configurations, which could be of clinical significance while performing root canal treatment on both side mandibular first permanent molars

Multiple Impact of Integrated Watershed Management in Low Rainfall Semi-Arid Region: A Case Study from Eastern Rajasthan, India

The agriculture in low rainfall areas of eastern Rajasthan, India is characterized by high risks from drought, degraded natural resources and pervasive poverty, food insecurity and malnutrition. In this region, water is the main limiting factor for upgrading rainfed agriculture. For such areas integrated watershed management is recognized as a potential approach for agriculture growth and rehabilitation of fragile and degraded lands. At Gokulpura-Goverdhanpura village in Bundi eastern Rajasthan, India an integrated watershed project was implemented using the holistic systems approach. This paper discusses the impacts of this watershed program on bio-physical, socio-economic, environmental and ecological parameters. Results indicate that due to watershed interventions the groundwater availability has substantially increased which brought changes in cropping patterns with high value crops. Significant increases in irrigated area, cropping intensity along with diversification of crops from traditional to commercial cash crops were recorded. The watershed program also significantly improved the socio-economic status of the watershed community. It has increased the income and reduced poverty of the people in the watershed. The watershed interventions generated good employment opportunities and significantly reduced the migration of both skilled and unskilled labor from the watershed village to urban areas. It has also improved the environmental quality and ecological status in the watershed. The watershed interventions increased the vegetative index or greenery, reduced runoff, soil loss, and land degradations and improved the bio-diversity in fragile ecosystems. Overall, the integrated watershed program at Gokulpura-Goverdhanpura provided resilience by ensuring continued and sustainable multiple outputs, besides soil and water conservation and other positive environmental effects

EXAFS study of intermetallics of the type RGe<SUB>2</SUB> (R=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Y) Part I: determination of Ge-Ge distances

A study of the EXAFS associated with the K x-ray absorption discontinuity of germanium in pure germanium and in the rare-earth germanides RGe2 (where R=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Y) has been carried out. The Ge-Ge distances have been obtained in these compounds. Considering the phase to the RGe2 system, the bond lengths in these compounds have been determined. The values obtained by us for the RGe2 compounds (R=La, Ce, Pr, Nd, Sm, Gd, Dy and Y) agree with those obtained earlier by crystallographic methods. The bond lengths for the compounds TbGe2, HoGe2 and ErGe2 are also being reported

Rural Prosperity through Integrated Watershed Management:A Case Study of Gokulpura-Goverdhanpura in Eastern Rajasthan. Global Theme on Agroecosystems Report no.36

The agriculture in eastern Rajasthan is characterized by high risks from drought, degraded natural resources and pervasive poverty. At Gokulpura-Goverdhanpura village in Bundi Rajasthan,ICRISAT along with partners implemented integrated watershed project using holistic systems approach with integrated genetic and natural resource management (IGNRM) strategy. This report discusses the multi-faceted impact of this watershed program. It has been found that the science-led participatory watershed program at Gokulpura- Goverdhanpura had made positive impacts on natural resources, rural livelihoods and environment. The major impact of watershed interventions was seen in improving the surface and groundwater availability. Increased water availability resulted in increased cropping intensity and diversification to more remunerative land use systems involving livestock, horticultural and vegetable production. Overall, the watershed program has reduced land degradation, enhanced agricultural productivity and incomes, decreased poverty of rural poor, reduced labor migration and improved environment quality

Scanning tunneling microscopy of the electronic structure of chemical vapor deposited diamond films

This article discusses scanning tunneling microscopy of the electronic structure of chemical vapor deposited diamond films

Enhanced productivity and income through balanced nutrition in Madhya Pradesh and Rajasthan Watersheds

Community watersheds technically supported by the consortium of institutions adopt holistic system's approach as against the compartmental approach of soil and water conservation. ICRISAT-led consortium used characterization of soil resources in the benchmark watersheds (Semli and Shyampura Watersheds, Dewas district and Madhusudangadh watershed, Guna district in Madhya Pradesh and Bundi Watershed, Bundi district in Rajasthan, India) as an entry point activity. Stratified sampling of fields on a toposequence in the watersheds revealed widespread deficiency of multiple nutrients particularly Zn (67-100%), B (72-100%) with an exception of Guna and S (72-100%) along with N and P, which could be limiting the yield potential in the watersheds. Farmers' participatory research trials with different crops showed tremendous yield advantages upto 79% over the farmers practice. The FPR trials also showed economic viability of amendment options with a net increased profit of Rs. 8190 ha-1 in case of wheat and Rs. 10740 with chickpea in M.P. watersheds. These FPR trials highlighted the urgency to provide right information about soil health to the farmers in time and empowering them to adopt balanced nutrient management strategies for increasing productivity and minimizing cost of inputs that are unnecessar

Competing risks analysis for neutrophil to lymphocyte ratio as a predictor of diabetic retinopathy incidence in the Scottish population

Background: Diabetic retinopathy (DR) is a major sight-threatening microvascular complication in individuals with diabetes. Systemic inflammation combined with oxidative stress is thought to capture most of the complexities involved in the pathology of diabetic retinopathy. A high level of neutrophil–lymphocyte ratio (NLR) is an indicator of abnormal immune system activity. Current estimates of the association of NLR with diabetes and its complications are almost entirely derived from cross-sectional studies, suggesting that the nature of the reported association may be more diagnostic than prognostic. Therefore, in the present study, we examined the utility of NLR as a biomarker to predict the incidence of DR in the Scottish population.Methods: The incidence of DR was defined as the time to the first diagnosis of R1 or above grade in the Scottish retinopathy grading scheme from type 2 diabetes diagnosis. The effect of NLR and its interactions were explored using a competing risks survival model adjusting for other risk factors and accounting for deaths. The Fine and Gray subdistribution hazard model (FGR) was used to predict the effect of NLR on the incidence of DR.Results: We analysed data from 23,531 individuals with complete covariate information. At 10 years, 8416 (35.8%) had developed DR and 2989 (12.7%) were lost to competing events (death) without developing DR and 12,126 individuals did not have DR. The median (interquartile range) level of NLR was 2.04 (1.5 to 2.7). The optimal NLR cut-off value to predict retinopathy incidence was 3.04. After accounting for competing risks at 10 years, the cumulative incidence of DR and deaths without DR were 50.7% and 21.9%, respectively. NLR was associated with incident DR in both Cause-specific hazard (CSH = 1.63; 95% CI: 1.28–2.07) and FGR models the subdistribution hazard (sHR = 2.24; 95% CI: 1.70–2.94). Both age and HbA 1c were found to modulate the association between NLR and the risk of DR.Conclusions: The current study suggests that NLR has a promising potential to predict DR incidence in the Scottish population, especially in individuals less than 65 years and in those with well-controlled glycaemic status.</p