Analyzing the sensitivity of a flood risk assessment model towards its input data

The Small Island Developing States are characterized by an unstable economy and low-lying, densely populated cities, resulting in a high vulnerability to natural hazards. Flooding affects more people than any other hazard. To limit the consequences of these hazards, adequate risk assessments are indispensable. Satisfactory input data for these assessments are hard to acquire, especially in developing countries. Therefore, in this study, a methodology was developed and evaluated to test the sensitivity of a flood model towards its input data in order to determine a minimum set of indispensable data. In a first step, a flood damage assessment model was created for the case study of Annotto Bay, Jamaica. This model generates a damage map for the region based on the flood extent map of the 2001 inundations caused by Tropical Storm Michelle. Three damages were taken into account: building, road and crop damage. Twelve scenarios were generated, each with a different combination of input data, testing one of the three damage calculations for its sensitivity. One main conclusion was that population density, in combination with an average number of people per household, is a good parameter in determining the building damage when exact building locations are unknown. Furthermore, the importance of roads for an accurate visual result was demonstrated

Rolling tachyon solution of two-dimensional string theory

We consider a classical (string) field theory of $c=1$ matrix model which was developed earlier in hep-th/9207011 and subsequent papers. This is a noncommutative field theory where the noncommutativity parameter is the string coupling $g_s$. We construct a classical solution of this field theory and show that it describes the complete time history of the recently found rolling tachyon on an unstable D0 brane.Comment: 19 pages, 2 figures, minor changes in text and additional references, correction of decay time (version to appear in JHEP.

Study on the effect of toxicity under highly arsenic prone zone in Nadia district of West Bengal in India

The present study was carried out on the basis of status of arsenic in soil, drinking water and plants, blood, urine and faeces of animals at arsenic prone zone. Within the ambit with the environment, the examination of animals was taken into consideration. They were screened and categorised on the degree of As toxicity. For field works animals were randomly selected from arsenic prone zone. The external manifestation indicated a complex syndrome and characteristic signs such as increased heart rate and respiratory rate, red urine, congested mucous membrane, anorexia, absence of ruminal motility, diarrhoea with blood, polyuria and unusual weight loss. The haematobiochemical changes such as low Hb level, decreased level of TEC, TLC and increased level ALT, AST, BUN and creatinine. Increased level of arsenic in urine, blood and faeces than the value of control animals could be the confirmatory indication of arsenic toxicity

Online Class Cover Problem

In this paper, we study the online class cover problem where a (finite or infinite) family $\cal F$ of geometric objects and a set ${\cal P}_r$ of red points in $\mathbb{R}^d$ are given a prior, and blue points from $\mathbb{R}^d$ arrives one after another. Upon the arrival of a blue point, the online algorithm must make an irreversible decision to cover it with objects from $\cal F$ that do not cover any points of ${\cal P}_r$. The objective of the problem is to place the minimum number of objects. When $\cal F$ consists of all possible translates of a square in $\mathbb{R}^2$, we prove that the competitive ratio of any deterministic online algorithm is $\Omega(\log |{\cal P}_r|)$. On the other hand, when the objects are all possible translates of a rectangle in $\mathbb{R}^2$, we propose an $O(\log |{\cal P}_r|)$-competitive deterministic algorithm for the problem.Comment: 27 pages, 23 figure

Comments on No-Hair Theorems and Stabilty of Blackholes

In the light of recent blackhole solutions inspired by string theory, we review some old statements on field theoretic hair on blackholes. We also discuss some stability issues. In particular we argue that the two dimensional string blackhole solution is semi-classically stable while the naked singularity is unstable to tachyon fluctuations. Finally we comment on the relation between the linear dilaton theory and the $2d$ blackhole solution.Comment: 14 page

A PROSPECTIVE STUDY COMPARING CONCURRENT CHEMORADIATION WITH OR WITHOUT GEFITINIB IN TREATMENT OF LOCALLY ADVANCED HEAD AND NECK CARCINOMA

ABSTRACT BACKGROUND-Concurrent chemoradiotherapy (CTRT) is now an acceptable definitive therapy for locally advanced head and neck carcinomas. But, multiple studies revealed that addition of anti-EGFR agent with CTRT  improves the loco-regional response at a cost of higher but acceptable toxicity. Our study aimed at assessing CTRT with or without Gefitinib in terms of treatment response and acute toxicity profile. MATERIALS AND METHODS- Patients with Locally advanced, non-metastatic, squamous cell carcinoma of Head-neck were  randomised in two groups-the control group  received  external beam radiotherapy  66Gy/33 fractions/6.5 weeks along with concurrent  injection Cisplatin at the dose of 100mg/m2 on day 1, 22, and 43 during radiation and the study group received concurrent chemoradiotherapy  along with  Tab Gefitinib-250 mg during the  duration of radiotherapy. Response assessment was done  after completion of treatment and all patients were followed up for treatment related acute toxicity during the course of treatment and then at every month for at least 6 months.  RESULTS- 46.66% of study arm (CTRT+Gefitinib) patients showed complete response and  Overall response was 79%. In control arm (CTRT alone), there was 51.6% complete response  and Overall response was 77%, though difference was statistically not significant (p value 0.84). Although statistically not significant, Gefitinib containing arm had numerically higher hematological, gastro-intestinal toxicity and weight loss. CONCLUSION- Gefitinib along with chemoradiation showed numerically higher overall response (complete response + partial response) and comparable acute toxicity profile in comparison to chemoradiation alone.   &nbsp