Landslide and Subsidence Potential due to the Progressive Development of Cave Network in Ella-Wellawaya Area, Sri Lanka

Carbonate rocks are highly soluble. Sinkholes are formed by both the failure of solution cavities andthe rapid removal of fines from solution cavities in carbonate and metacarbonate rocks. Sri Lankanlandmass is composed of Proterozoic high-grade metamorphic rocks such as gneiss andmetacarbonates like marble. Large caves in Sri Lanka form in both marble and gneiss. A few landsubsidence events have occurred recently in Ella-Wellawaya area, which is a hilly terrain. In addition,some cases of groundwater table lowering, which has caused drying of dug wells have also beenrecorded within the area, apparently related to a major development project presently under way in thearea.The main objective of this paper is to draw the immediate attention of local researchers andauthorities whom are working on mitigation and management of disasters, groundwater and climatechange, showing the importance of carrying out detail studies on potential landslides and landsubsidence of Ella-Wellawaya area for avoiding and minimising loss of humans and properties.Preliminary surveys on some land subsidence cases and speleological studies including geology,hydrogeology and morphological mapping of the underground caves in the area have been activelycarried out. According to the results, it is shown that the subsidence is likely to be correlated with thecollapsing of cavities and weathered zones in metacarbonates, and disturbances to the groundwatertable. Field explorations done during the last two years have discovered several large undergroundcaves in the area some more than 100 m across. Most of the cave roofs have been thinned by thebreakdown of bedrock along weak zones such as joints. Since the process of collapse, trigged byweathering is continuing and patches and lenses of carbonate rocks observed in the caves are stillbeing dissolved, the expansion of the cave spaces is unending. Some of the chambers of these cavesare aligned parallel to the steep slopes in the Ella-Wellawaya area and some acted as undergroundwater conduits and storages during the rainy seasons. The Ella-Wellawaya area has been undergone achange in vegetation cover since the colonial period and hence the area is more prone to soil erosionwhich exposes the near surface natural cavities to the underground caves. Present human exposuresand interactions within the susceptible slopes have brought lives and properties under threat. Hencefuture land subsidence and landslide occurrences are highly predictable with the recent conditions inthe area and hence threat to human life and properties is high. The tourism industry, unique to the areacould particularly be affected. Hence such hazardous should properly be identified and demarcatedand the erosion triggered by present vegetation changes must properly be addressed.Keywords: Metacarbonate rocks, Subsidence, Ella-Wellawaya, Cave network, Erosio

Out-of-pocket expenditure in accessing healthcare services among Chronic Kidney Disease patients in Anuradhapura District

Introduction: Chronic Kidney Disease (CKD) has significant economic impact on both patients’ households and the country. Objectives: To assess the out-of-pocket (OOP) expenditure of accessing health services among CKD patients in Anuradhapura District.Methods: This community based cross-sectional study included a representative sample of 1174 registered CKD patients from all 19 Medical Officer of Health areas in the district of Anuradhapura. Trained para-medical staff visited the households and administered an interviewer administered questionnaire to gather information.Results: A total of 1118 CKD patients participated. Mean age was 58.3 (SD 10.8) years. Fifty nine (5.3%) patients had been hospitalized during the six months preceding data collection. The total OOP for a hospital admission for one patient was Rs.3625 (IQR 1650-8760). Thirty eight (3.4%) patients were on dialysis. The median direct cost per patient for an episode of dialysis was Rs.595 (IQR 415-995) while the median direct cost for a dialysis patient per month was Rs.5490 (IQR 3950-10934). In the study population a total of 1095 (98.0%) had attended clinic at least once during the six months preceding the study. The OOP expenditure for a single clinic visit for one patient was Rs.434 (IQR 200-860). Conclusions: CKD patients living in Anuradhapura district spend significant amounts on accessing health care which can worsen their economic hardships. Planned interventions are warranted in order to improve their quality of life and financial situation

Nonperturbative transverse-momentum-dependent effects in dihadron and direct photon-hadron angular correlations in p+pp+p collisions at s=200\sqrt{s}=200 GeV

International audienceDihadron and isolated direct photon-hadron angular correlations are measured in p+p collisions at s=200  GeV. The correlations are sensitive to nonperturbative initial-state and final-state transverse momenta kT and jT in the azimuthal nearly back-to-back region Δϕ∼π. To have sensitivity to small transverse momentum scales, nonperturbative momentum widths of pout, the out-of-plane transverse-momentum component perpendicular to the trigger particle, are measured. In this region, the evolution of pout can be studied when several different hard scales are measured. These widths are used to investigate possible effects from transverse-momentum-dependent factorization breaking. When accounting for the longitudinal-momentum fraction of the away-side hadron with respect to the near-side trigger particle, the widths are found to increase with the hard scale; this is qualitatively similar to the observed behavior in Drell-Yan and semi-inclusive deep-inelastic scattering interactions, where factorization is predicted to hold. The momentum widths are also studied as a function of center-of-mass energy by comparing to previous measurements at s=510  GeV. The nonperturbative jet widths also appear to increase with s at a similar xT, which is qualitatively consistent to similar measurements in Drell-Yan interactions. Future detailed global comparisons between measurements of processes where transverse-momentum-dependent factorization is predicted to hold and be broken will provide further insight into the role of color in hadronic interactions

Correlations of μμ\mu\mu, eμe\mu, and eeee pairs in pp+pp collisions at s=200\sqrt{s}=200 GeV and implications for ccˉc\bar{c} and bbˉb\bar{b} production mechanisms

PHENIX has measured the azimuthal correlations of muon pairs from charm and bottom semi-leptonic decays in $p$+$p$ collisions at $\sqrt{s}=200$ GeV, using a novel analysis technique utilizing both unlike- and like-sign muon pairs to separate charm, bottom and Drell-Yan contributions. The dimuon measurements combined with the previous electron-muon and dielectron measurements span a wide range in rapidity, and are well described by PYTHIA Tune A. Through a Bayesian analysis based on PYTHIA Tune A, we show that leading order pair creation is the dominant $(76\%\pm^{14}_{19}\%)$ contribution for $b\bar{b}$ production, whereas the data favor the scenario in which next-to-leading-order processes dominate $c\bar{c}$ production. The small contribution of next-to-leading-order processes in $b\bar{b}$ production at the collision energies of the Relativistic Heavy Ion Collider contrasts with the case at Large-Hadron-Collider energies, where next-to-leading-order processes are expected to dominate

Measurements of μμ\mu\mu pairs from open heavy flavor and Drell-Yan in p+pp+p collisions at s=200\sqrt{s}=200 GeV

International audiencePHENIX reports differential cross sections of μμ pairs from semileptonic heavy-flavor decays and the Drell-Yan production mechanism measured in p+p collisions at s=200  GeV at forward and backward rapidity (1.2<|η|<2.2). The μμ pairs from cc¯, bb¯, and Drell-Yan are separated using a template fit to unlike- and like-sign muon pair spectra in mass and pT. The azimuthal opening angle correlation between the muons from cc¯ and bb¯ decays and the pair-pT distributions are compared to distributions generated using pythia and powheg models, which both include next-to-leading order processes. The measured distributions for pairs from cc¯ are consistent with pythia calculations. The cc¯ data present narrower azimuthal correlations and softer pT distributions compared to distributions generated from powheg. The bb¯ data are well described by both models. The extrapolated total cross section for bottom production is 3.75±0.24(stat)±0.500.35(syst)±0.45(global)  [μb], which is consistent with previous measurements at the Relativistic Heavy Ion Collider in the same system at the same collision energy and is approximately a factor of 2 higher than the central value calculated with theoretical models. The measured Drell-Yan cross section is in good agreement with next-to-leading-order quantum-chromodynamics calculations

Single-spin asymmetry of J/ψJ/\psi production in p+pp+p, p+p+Al, and p+p+Au collisions with transversely polarized proton beams at sNN=200\sqrt{s_{_{NN}}}=200 GeV

International audienceWe report the transverse single-spin asymmetries of J/ψ production at forward and backward rapidity, 1.2<|y|<2.2, as a function of J/ψ transverse momentum (pT) and Feynman-x (xF). The data analyzed were recorded by the PHENIX experiment at the Relativistic Heavy Ion Collider in 2015 from p+p, p+Al, and p+Au collisions with transversely polarized proton beams at sNN=200  GeV. At this collision energy, single-spin asymmetries for heavy-flavor particle production of p+p collisions provide access to the spin-dependent gluon distribution and higher-twist correlation functions inside the nucleon, such as the gluon Qiu-Sterman and trigluon correlation functions. Proton+nucleus collisions offer an excellent opportunity to study nuclear effects on the correlation functions. The data indicate a positive asymmetry at the two-standard-deviation level in the p+p data for 2  GeV/c<pT<10  GeV/c at backward rapidity and negative asymmetries at the two-standard-deviation level in the p+Au data for pT<2  GeV/c at both forward and backward rapidity, while in p+Al collisions the asymmetries are consistent with zero within the range of experimental uncertainties