Lie symmetries, Kac-Moody-Virasoro algebras and integrability of certain (2+1)-dimensional nonlinear evolution equations

In this paper we study Lie symmetries, Kac-Moody-Virasoro algebras, similarity reductions and particular solutions of two different recently introduced (2+1)-dimensional nonlinear evolution equations, namely (i) (2+1)-dimensional breaking soliton equation and (ii) (2+1)-dimensional nonlinear Schr\"odinger type equation introduced by Zakharov and studied later by Strachan. Interestingly our studies show that not all integrable higher dimensional systems admit Kac-Moody-Virasoro type sub-algebras. Particularly the two integrable systems mentioned above do not admit Virasoro type subalgebras, eventhough the other integrable higher dimensional systems do admit such algebras which we have also reviewed in the Appendix. Further, we bring out physically interesting solutions for special choices of the symmetry parameters in both the systems

Social transformations of rural communities through ecotourism : a systematic review / Velan Kunjuraman and Rosazman Hussin

This review paper observes the gap in the tourism literature, specifically on issues regarding communities’ qualities of life through eco(tourism) activities in both developed and developing countries. Based on the previous literature, it was found that the term ‘social transformation’ is often overlooked in the literature and less focused by tourism researchers. The issue of social transformation in tourism development is crucial to be studied in order to understand the communities’ quality of life when engaging in tourism activities and how they manage impacts. In this paper, literature on community participation in tourism activities and the issue of tourism impacts towards communities’ qualities of life is also studied. The main contribution of this paper is the discussion on the issue of social transformations of local communities through tourism is scarce and proposes the need to study by having some successful case studies in both developed and developing countries

A Path to the Direct Detection of sub-GeV Dark Matter Using Calorimetric Readout of a Superfluid 4^4He Target

A promising technology concept for sub-GeV dark matter detection is described, in which low-temperature microcalorimeters serve as the sensors and superfluid $^4$He serves as the target material. A superfluid helium target has several advantageous properties, including a light nuclear mass for better kinematic matching with light dark matter particles, copious production of scintillation light, extremely good intrinsic radiopurity, a high impedance to external vibration noise, and a unique mechanism for observing phonon-like modes via liberation of $^4$He atoms into a vacuum (`quantum evaporation'). In this concept, both scintillation photons and triplet excimers are detected using calorimeters, including calorimeters immersed in the superfluid. Kinetic excitations of the superfluid medium (rotons and phonons) are detected using quantum evaporation and subsequent atomic adsorption onto a microcalorimeter suspended in vacuum above the target helium. The energy of adsorption amplifies the phonon/roton signal before calorimetric sensing, producing a gain mechanism that can reduce the techonology's recoil energy threshold below the calorimeter energy threshold. We describe signal production and signal sensing probabilities, and estimate electron recoil discrimination. We then simulate radioactive backgrounds from gamma rays and neutrons. Dark matter - nucleon elastic scattering cross-section sensitivities are projected, demonstrating that even very small (sub-kg) target masses can probe wide regions of as-yet untested dark matter parameter space

Challenges of community-based homestay programme in Sabah, Malaysia: hopeful or hopeless?

This paper explores the challenges faced by the participants of community-based homestay programme in Dagat Village of Lower Kinabatangan-Segama Wetlands of Sabah, Malaysia. Primary data were gathered through field observation and in-depth interviews conducted with the participants in September 2015 and March 2016. The results of this study revealed that the tourism activities based on homestay programme in Dagat Village have the potential to be developed because of its vast natural resources but it was found that the local community faced many challenges during their homestay operation at the study site, which include lack of infrastructure development, poor promotional activity, lack of trained human resource, safety and security issues, poor local leadership, and lack of tourism management experiences that cause the homestay programme operation to be unsustainable. Therefore, this study recommends the importance of collaboration and partnerships among tourism stakeholders in order to achieve a successful ecotourism development

Establishing Privacy Advisory Commissions for the Regulation of Facial Recognition Systems at the Municipal Level

As facial recognition systems (FRS) become widely available, a growing number of local governing bodies across the country have adopted these technologies. Without regulating how and when these technologies are used, the adoption of FRS by municipal governments has the potential to violate civil liberties and disproportionately harm marginalized groups. FRS may be an invaluable tool for law enforcement; however, best practices must be adopted to curb their misuse, specifically at the municipal level. We propose that cities considering procurement of FRS create an independent privacy advisory commission with a clear mandate, guaranteed cooperation from local government, technology expertise, and community stakeholder input

Damage Patterns

This chapter provides an overview of the macroseismic effects of the Bhuj earthquake. Such information is useful for several reasons. First, direct information about the vulnerability of structures to strong ground motion is useful for assessing, and perhaps mitigating, the hazard posed to similar structures by future large earthquakes. Secondly, given the paucity of instrumental recordings of the Bhuj earthquake, macroseismic data can provide useful information about the spatial variation of ground motions. Finally, detailed damage assessments for this earthquake can be compared to available accounts of historic earthquakes in India and other similar tectonic regimes around the world. These comparisons will provide additional insight into the magnitude of important earthquakes for which there are few or no instrumental recordings. The Bhuj earthquake is of particular interest because of the possibility that it represents an analog for the principal New Madrid (central United States) earthquakes of 1811-1812. The Bhuj earthquake occurred much closer to an active plate boundary than did the New Madrid events, and the Bhuj earthquake might therefore be considered a plate boundary-related event. However, in both cases, the regions primarily affected by the earthquake are stable continental interiors with low attenuation. A quantification of damage patterns, such as that presented in this chapter, can provide useful insight into the attenuation and frequency content of ground motions, which may in turn be useful in resolving whether the Bhuj earthquake should be considered interplate or intraplate for the purpose of data classification. This chapter combines two different approaches to quantify macroseismic effects of the Bhuj earthquake. First, a large-scale map of intensities was compiled based on media accounts. Second, ground-level surveys of damage in towns and villages across the epicentral area by the India-U.S. Geotechnical Earthquake Engineering Reconnaissance Team were synthesized. This approach provides both coarse- and fine-scale overviews of damage, as well as an opportunity to compare detailed ground-based intensity results to a "broad brush" intensity value determined from one or a small handful of media accounts for any one location

Antiulcer activity of Muntingia calabura leaves involves the modulation of endogenous nitric oxide and nonprotein sulfhydryl compounds

Context: Muntingia calabura L. (Muntingiaceae) is a native plant species of the American continent and is widely cultivated in warm areas in Asia, including Malaysia. The plant is traditionally used to relieve pain from gastric ulcers. Objective: This study was designed to determine the antiulcer activity of a methanol extract of M. calabura leaves (MEMC) and the possible mechanisms of action involved. Materials and methods: An acute toxicity study was conducted using a single oral dose of 2000 mg/kg MEMC. The antiulcer activity of MEMC was evaluated in absolute ethanol- and indomethacin-induced gastric ulcer rat models. MEMC was administered orally (dose range 25–500 mg/kg) to rats fasted for 24 h. The animals were pretreated with NG-nitro-l-arginine methyl esters (l-NAME) or N-ethylmaleimide (NEM) prior to MEMC treatment to assess the possible involvement of endogenous nitric oxide (NO) and nonprotein sulfhydryl (NP-SH) compounds in the gastroprotective effect of MEMC. Results: As the administered dose did not cause toxicity in the rats, the oral median lethal dose (LD50) of MEMC was >2000 mg/kg in rats. MEMC exerted significant (p < 0.001) gastroprotective activity in the ethanol- and indomethacin-induced ulcer models dose-dependently. Histological evaluation supported the observed antiulcer activity of MEMC. l-NAME and NEM pretreatment significantly (p < 0.05) reversed and abolished the gastroprotective effect of MEMC, respectively. Discussion and conclusion: The results obtained indicate that MEMC has significant antiulcer activity that might involve the participation of endogenous NO and NP-SH compounds. These findings provide new pharmacological information regarding the potential use of M. calabura

A symmetry classification for a class of (2+1)-nonlinear wave equation

In this paper, a symmetry classification of a $(2+1)$-nonlinear wave equation $u_{tt}-f(u)(u_{xx}+u_{yy})=0$ where $f(u)$ is a smooth function on $u$, using Lie group method, is given. The basic infinitesimal method for calculating symmetry groups is presented, and used to determine the general symmetry group of this $(2+1)$-nonlinear wave equation