1,737 research outputs found
A Study of the LXeGRIT Detection Efficiency for MeV Gamma-Rays during the 2000 Balloon Flight Campaign
LXeGRIT - Liquid Xenon Gamma-Ray Imaging Telescope - is the first prototype
of a Compton telescope for \MeV \g-ray astrophysics based on a LXe time
projection chamber. One of the most relevant figures of merit for a Compton
telescope is the detection efficiency for \g-rays, which depends on diverse
contributions such as detector geometry and passive materials, trigger
efficiency, dead time, etc. A detailed study of the efficiency of the LXeGRIT
instrument, based both on laboratory measurements and Monte Carlo simulations,
is presented in this paper.Comment: 20 pages, 15 figures; submitted to NIM
Detection of liquid xenon scintillation light with a Silicon Photomultiplier
We have studied the feasibility of a silicon photomultiplier (SiPM) to detect
liquid xenon (LXe) scintillation light. The SiPM was operated inside a small
volume of pure LXe, at -95 degree Celsius, irradiated with an internal Am-241
alpha source. The gain of the SiPM at this temperature was estimated to be 1.8
x 10^6 with bias voltage at 52 V. Based on the geometry of the setup, the
quantum efficiency of the SiPM was estimated to be 22% at the Xe wavelength of
178 nm. The low excess noise factor, high single photoelectron detection
efficiency, and low bias voltage of SiPMs make them attractive alternative UV
photon detection devices to photomultiplier tubes (PMTs) for liquid xenon
detectors, especially for experiments requiring a very low energy detection
threshold, such as neutralino dark matter searches
Analysis of Search Incidents and Lost Person Behavior in Yosemite National Park
Every year thousands of people are reported lost or missing in wilderness areas and in response, a search and rescue (SAR) operation is launched to locate, stabilize, and extract those missing. Actually locating the subject is often the most difficult of these processes. This study attempts to improve upon search operations by analyzing lost person behavior at the "local" level. If a search manager knew what a lost subject was most likely to do when lost, then they could plan the search accordingly and return them to safety much quicker. Additionally, if National Park officials knew who was becoming lost, and when and where this occurred, steps could be taken to prevent these people from becoming lost in the first place. Eleven years (2000-2010) of Search and Rescue case incident reports from Yosemite National Park (2,308 in total) were examined and 213 searches were retained for analysis. It was determined that approximately 62% of incidents involve missing hikers. Nearly two thirds of the searches were for one subject and about two-thirds of these involved males. The mean age of missing persons was 36 years old. Most people were reported missing in July, on Saturday, and between the hours of 2 and 3 p.m. Almost half of people reported as missing were actually lost while others were merely separated from their party, or overdue. Contributing factors include losing the trail accidentally, failure to communicate the intended plan, and miscalculating the time or distance of the planned route, among others. Within a Geographic Information System (GIS) the Initial Planning Point (IPP), the point at which the person was last seen or known to be, and the found location was georeferenced for each incident using the point radius method. This allowed for a Getis-Ord Gi* analysis to be conducted of both the IPPs and found locations and "hot spots" were identified for each. The GIS also provided an environment for analyzing lost person behavior. Within Yosemite National Park lost hikers most often utilized route traveling in order to reorient themselves. Additionally, descriptive lost person behavior statistics for hikers were calculated, including: horizontal distance from the IPP to the found location, vertical elevation change from the IPP to the found location, dispersion angle from intended destination to the found location, and the track offset of the found location. These "local" results were then compared to "international" statistics presented by the International Search and Rescue Incident Database (ISRID) using a chi-square goodness of fit test. It was found that the ISRID data provided for horizontal distance from the IPP and track offset were not suitable for use in Yosemite while the data pertaining to vertical elevation change from the IPP and the dispersion angle could potentially be utilized for search planning
Ecotourism as a field of Sustainable Rural Development: A case study of Bhor Tehsil (MS)
Eco-tourism focuses on local cultures, wilderness adventures, volunteering, personal growth and learning new ways to live on our vulnerable planet. It is considered the fastest growing market in the tourism industry, according to the World Tourism Organization with an annual growth rate of 9.6% worldwide and representing 8% of the world Gross Domestic Product, 11.4% of all consumers spending. Tourism or ecotourism is inherent desire of human beings, which developed with the progress of human civilization. Every man on this planet earth is very fond of tourism, hence always attracted towards nature. The mountains, hills, valleys, oceans, rivers, lakes, islands, waterfalls, forests, wild animals, birds, butterflies etc. have become important attractions for the ecotourists. The improved standard of life and economic status of middle class society has brought ecotourism within their reach. At present there is pressing demand for planned, well-developed and perfectly managed ecotourism. India is truly famous for hospitality. "Atithi Deo Bhav", means the visitors or guests are equal to God in Indian culture due to which India become the top most place for ecotourism in the world. The diverse culture, rich bio diversity, conductive climate, greenery and the peaceful as well as spiritual mind of the Indian people have become the main attractions for ecotourism.Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â The pleasant weather, natural lakes, green hills, beautiful valleys are the main attractions for ecotourists in Bhor Tehsil of Pune district. Hence there is an urgent need to investigate the hidden potential of ecotourism management and sustainable development. Not only this, but it also become the potential area of employment to rural people and youth. Ecotourism development may become pivotal for socioeconomic transformation of villages with natural ecotourism sites
The Role of ID3 and PCB153 in the Hyperproliferation and Dysregulation of Lung Endothelial Cells
Uncontrolled growth of vascular stem cells as a result of endothelial-mesenchymal transition is considered to cause hyper-proliferative vascular remodeling in severe pulmonary arterial hypertension (PAH) patients. Hyperplastic intimal growth is one of the causes of closure of the lumen of pulmonary arterioles. This abnormal vessel remodeling leads to the progressive increase in pressure of the pulmonary arterioles causing severe PAH; and debilitating harm to patients resulting in mortality from right heart failure. Environmental factors, including polychlorinated biphenyls (PCBs), are considered to be involved in hyper-proliferative vascular remodeling because genetic makeup can only explain about 10% of severe PAH cases. PCB involvement in lung toxicity has received attention because (i) they have been reported to accumulate in the lung; (ii) PCBs produce pathological vascular remodeling in the experimental model; high levels of PCBs are found in human lung tissue; and (iii) epidemiological studies show the association between lung toxicity and PCBs; and prevalence of hypertension and elevated concentrations of particularly PCB153. Recent studies identify PCB153 as one of the largest contributors for total PCB body burden in humans. Our previous studies demonstrated PCB153 mediated vascular endothelial dysfunction and activated the inhibitor of differentiation protein 3 (ID3). ID3 is an important determinant of mitogen and reactive oxygen species-induced G1→S phase cell cycle progression. Although phosphorylation of ID3 increases cell growth by antagonizing the transcription of cell cycle inhibitors, still there is a critical gap in understanding the molecular mechanism(s) of pulmonary proliferative vascular remodeling associated with PCB exposure in humans and the role of the transcription regulator ID3. Our overall objective was to investigate ID3 mediated transcriptional reprogramming as a driver of PCB153-induced pathological proliferative vascular remodeling. Stable ectopic expression of ID3 in lung endothelial cells contributed to endothelial-mesenchymal transition (EndMT), cell proliferation, and cell migration. Using an endothelial spheroid assay, an established method to measure aberrant hyper-proliferation of endothelial cells in PAH patients, we show that stable ectopic expression of ID3 increased the number and size of vascular spheres. ID3 overexpressing cells exposed to environmentally relevant concentrations of PCB153 showed a two-fold increase in cell proliferation as determined by MTT, SRB, and BrdU assays. ID3 overexpressing cells showed the loss of VE-cadherin and gain of MMP9 and vimentin, which are markers of EndMT. PCB153 also increased phosphorylation of ID3 in lung endothelial cells. To determine the molecular mechanism by which ID3 contributes to hyper-proliferative endothelial cells, we investigated ID3 transcriptional reprogramming using ChIP-Seq and RNA-Seq technology. We show here for the first time that ID3 is part of a more general mechanism of transcriptional regulation. Our ChIP-Seq data show that ID3 binds to a subset of approximately 1200 target genes. Comprehensive motif analysis of ChIP-Seq data using the MEME Suite software toolkit revealed that ID3 bound to the GAGAGAGAGA motif sequence on genomic DNA. We also show a significant preference of ID3 binding to motifs associated with transcription factors IRF1, BC11A, IRF4, PRDM1, FOXJ3, SMAD4, ZBTB6, GATA1, and STAT2. Using an integrative approach of ChIP-Seq and RNA-Seq data, we identified 19 genes whose promoter region was bound by ID3 and RNA was differentially expressed in ID3 overexpressing cells. In summary, our data demonstrated that PCB153 and/or ID3 induces proliferation of lung endothelial cells via transcriptional reprogramming. Discoveries from these findings will lay the necessary groundbreaking work for testing the efficacy of ID3 antagonists for the prevention and treatment of pathological vascular remodeling as well as provide a new paradigm by which PCBs may contribute to lung vascular toxicity
Agrotourism is an Immerging field of Sustainable Development for Rural Area: A case study of BhorTahsil of Maharashtra.
Agrotourism is considered as the fastest growing sector in the tourism industry. The concept has been successfully implemented in Maharashtra. It has become a new avenue for earning the income for the rural farmers. In Maharashtra, rural areas have formed an organization named Maharashtra State Agricultural and Rural Tourism (MART). There are about 150 Agro tourism centers in the state working without financial assistance of the Government schemes. Agrotourismfocuses on local Agriculture pattern and agro cultures, wilderness adventures, volunteering, personal growth and learning new ways to live on our vulnerable planet. It is considered the fastest growing market in the tourism industry, according to the World Tourism Organization with an annual growth rate of 5% worldwide and representing 6% of the world Gross Domestic Product, 11.4% of all consumers spending. Foreign Tourist Arrivals (FTAs) in India during 2013 were 6.97 million with a growth of 5.9% as compared to the FTAs of 6.58 million during 2012 registering a growth of 4.3% over 2011. The Foreign Exchange Earnings (FEEs) from tourism in terms of US dollars during 2013 was US 17.737 billion during 2012 registering a growth of 7.1% over 2011. Substantial growth was observed in domestic tourism sector as the domestic tourist visits during the year 2013 was 1145 million, showing a growth of 9.59% over 2012.Ă‚Â Ă‚Â Tourism or Agrotourism is inherent desire of human beings, which developed with the progress of human civilization. Every man on this planet earth is very fond of tourism, hence always attracted towards nature. The mountains, hills, valleys, oceans, rivers, lakes, islands, waterfalls, forests, wild animals, birds, butterflies etc. have become important attractions for the agrotourists. The improved standard of life and economic status of middle class society has brought ecotourism within their reach. At present there is pressing demand for planned, well-developed and perfectly managed ecotourism. India is truly famous for hospitality. "AtithiDeoBhav", means the visitors or guests are equal to God in Indian culture due to which India become the top most place for ecotourism in the world. The diverse culture, rich bio diversity, conductive climate, greenery and the peaceful as well as spiritual mind of the Indian people have become the main attractions for ecotourism as well as Agrotourism.Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â Ă‚Â The pleasant weather, natural lakes, green hills, beautiful valleys and agriculture (Manly paddy field) are the main attractions for agrotourists in BhorTahsil Pune district. Hence there is an urgent need to investigate the hidden potential of Agrotourismmanagement and sustainable development. Not only this, but it also become the potential area of employment to rural people and youth. Ecotourism development may become pivotal for socioeconomic transformation of villages with naturalecotourism sites
Collaborative learning among high school students in an alternative styles strings ensemble
Traditional teaching and learning structures in large music ensembles (e.g., orchestra) place the teacher as the leader and sole dispenser of knowledge with the students as passive learners (e.g., Allsup, 2003; Hendricks, 2018; Rogoff, 1994). However, research indicates that students can play an active role in the learning that occurs in school music ensembles. Alternative style string ensembles, which often involve informal learning, are ideal musical settings for the development of a student-centered, collaborative learning environment. The purpose of this study was to explore how high school string students collaborated with each other as they learned alternative music styles music in an after-school fiddle group. Communities of practice (Lave & Wenger, 1991) served as the theoretical framework for this investigation in which I explored student participants’ perspectives, experiences, and interactions as they learned new alternative styles music. During the course of this study I also explored the changing learning roles of the participants and the role of the teacher as facilitator during the learning process. The following research questions guided this study: (1) What various roles did the students undertake in their community of practice? (2) How did the participants move toward legitimate participation as they collaborated with each other in alternative styles of music? (3) How did the teacher serve as facilitator of this community of practice?
Data were collected via observations and by way of semi-structured interviews of the participants and their teacher. I used a system of coding to identify important components of learning, what the participants learned, and their movement through the community of learning. From these codes, I identified the following themes: teaching and learning aurally, collaborative learning, changing learning roles of students and the teacher, transfer of participation, leadership and sharing knowledge, student centered learning, enjoyment of playing with others, confidence, perseverance, and students gaining a deeper interest and understanding of the music. These themes served as the basis for presenting the findings for the reader. Findings from this study may inform secondary school string teachers in developing strategies for incorporating alternative styles and collaborative learning environments into their own string curricula. Findings may also provide insights with helping teachers in developing and refining student-centered collaborative learning settings and alternative styles
A study of Centchroman users with special reference to its contraceptive benefit
Background: Centchroman (INN: Ormeloxifene), was developed at CDRI, Lucknow in 1967. This drug was finally approved and licensed in 1991 and launched as Saheli and Choice-7 for marketing in 1992. The Ministry of Health and Family Welfare, India has now introduced centchroman in national family planning programme under the trade name “Chhaya” from April 2016. Centchroman is a novel nonsteroidal contraceptive that inhibits the fertilised ovum from implantation and thus prevents pregnancy. The aim of this study was to assess the effectiveness, side effects, discontinuation rates and failure rate among the users of Centchroman (Chhaya).Methods: The retrospective study was conducted by reviewing the records of Centchroman (Chhaya) contraceptives acceptor over the period of one year from September 2017 to August 2018 in family welfare clinic of Department of Obstetrics and Gynecology at Tomo Riba Institute of Health and Medical Science, a tertiary level center in Naharlagun, Arunachal Pradesh, India.Results: A total of 146 women were evaluated for the study. Majority of the women were in the age group of 20-30 years (76.02%) with mean age of 26 years. Most of the centchroman acceptors were multipara (74.65%) and women in post-abortion (38.35%) and postpartum group (36.3%). Duration of use ranged from 3 months in 146 women to 12 months in 98 women. The discontinuation rate was 31.5%. The major menstrual complaint was delayed menstrual cycle in 15.06% women and irregular cycle in 10.95%. Of the 146 women in the study group, pregnancy occurred in 3 women. Pearl index calculated for centchroman was 2.05/HWY.Conclusions: Centchroman is a non-steroidal, non-hormonal oral contraceptive drug with good therapeutic efficacy and a favourable side effect profile. Centchroman has an important place in postpartum contraception due to its safety profile in breastfeeding women
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