4,841 research outputs found

    ICT Governance versus Community Empowerment: Grassroots Evidence from Bangladesh

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    International audienceInformation and Communication Technologies (ICT) is a catalyst to enhance the level of community empowerment - with this motivation, this paper reports on a research study on "Community Empowerment Through ICTs: Evidence from Grassroots in Bangladesh and India". The evidence from an early benchmark study from Bangladesh shows that ICT penetration on its own is not proportionately related with community empowerment. Rather, ICT penetration with a precise application of ICT governance, strengthens community empowerment. The evidence also shows that if ICT penetration is high, but ICT governance is low, ICT does not remain as high a catalytic factor for community empowerment

    Challenges & solutions in a hybrid mHealth mobile app

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    The paper describes the various problems and challenges encountered during the development and remote data collection in a cross-platform hybrid application developed for remote monitoring of participants and what solutions were implemented to mitigate them. These problems and challenges are universal for hybrid applications and this paper digs deep into these in the domain of large-scale, long-duration mHealth research studies. From technical issues to issues with user compliance, this paper discusses the core problems inherent to these types of studies and technologies, and how to mitigate them

    The profile of a narrow line after single scattering by Maxwellian electrons: relativistic corrections to the kernel of the integral kinetic equation

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    The frequency distribution of photons in frequency that results from single Compton scattering of monochromatic radiation on thermal electrons is derived in the mildly relativistic limit. Algebraic expressions are given for (1) the photon redistribution function, K(nu,Omega -> nu',Omega'), and (2) the spectrum produced in the case of isotropic incident radiation, P(nu -> nu'). The former is a good approximation for electron temperatures kT_e < 25 keV and photon energies hnu < 50 keV, and the latter is applicable when hnu(hnu/m_ec^2) < kT_e < 25 keV, hnu < 50 keV. Both formulae can be used for describing the profiles of X-ray and low-frequency lines upon scattering in hot, optically thin plasmas, such as present in clusters of galaxies, in the coronae of accretion disks in X-ray binaries and AGNs, during supernova explosions, etc. Both formulae can also be employed as the kernels of the corresponding integral kinetic equations (direction-dependent and isotropic) in the general problem of Comptonization on thermal electrons. The K(nu,Omega -> nu',Omega') kernel, in particular, is applicable to the problem of induced Compton interaction of anisotropic low-frequency radiation of high brightness temperature with free electrons in the vicinity of powerful radiosources and masers. Fokker-Planck-type expansion (up to fourth order) of the integral kinetic equation with the P(nu -> nu') kernel derived here leads to a generalization of the Kompaneets equation. We further present (1) a simpler kernel that is necessary and sufficient to derive the Kompaneets equation and (2) an expression for the angular function for Compton scattering in a hot plasma, which includes temperature and photon energy corrections to the Rayleigh angular function.Comment: 29 pages, 17 figures, accepted for publication in ApJ, uses emulateapj.sty, corrects misprints in previous astro-ph versio

    International Student Adaptation Factors in Malaysian Public Universities

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    The research focuses on the internationalization of Malaysia's Higher Education by ensuring that the increasing number of international students will be accommodated fairly. The issues addressed will revolve around the Psychological Factor with the Intercultural Adaptation Model by Kim Young Yun as the foundation. The model was used as the framework to focus on the psychological issue the international students experienced. Twelve international students were selected as respondents from four public universities in Malaysia: UPM, UKM, UM and USM as the main research area. This qualitative research used a semi-structured interview as the main instrument of data collection, online interview using WeBex and Google Meet were used. Respondents were selected using quota sampling with varying characteristics. Results were analysed by using the colour-coding technique assisted by ATLAS.ti. Although it is psychologically challenging, some of it is actually helping as a part of their life circle's support system, namely the presence of supportive classmates and support group

    Investigating the Use of Digital Health Technology to Monitor COVID-19 and Its Effects: Protocol for an Observational Study (Covid Collab Study)

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    BACKGROUND: The ubiquity of mobile phones and increasing use of wearable fitness trackers offer a wide-ranging window into people’s health and well-being. There are clear advantages in using remote monitoring technologies to gain an insight into health, particularly under the shadow of the COVID-19 pandemic. OBJECTIVE: Covid Collab is a crowdsourced study that was set up to investigate the feasibility of identifying, monitoring, and understanding the stratification of SARS-CoV-2 infection and recovery through remote monitoring technologies. Additionally, we will assess the impacts of the COVID-19 pandemic and associated social measures on people’s behavior, physical health, and mental well-being. METHODS: Participants will remotely enroll in the study through the Mass Science app to donate historic and prospective mobile phone data, fitness tracking wearable data, and regular COVID-19–related and mental health–related survey data. The data collection period will cover a continuous period (ie, both before and after any reported infections), so that comparisons to a participant’s own baseline can be made. We plan to carry out analyses in several areas, which will cover symptomatology; risk factors; the machine learning–based classification of illness; and trajectories of recovery, mental well-being, and activity. RESULTS: As of June 2021, there are over 17,000 participants—largely from the United Kingdom—and enrollment is ongoing. CONCLUSIONS: This paper introduces a crowdsourced study that will include remotely enrolled participants to record mobile health data throughout the COVID-19 pandemic. The data collected may help researchers investigate a variety of areas, including COVID-19 progression; mental well-being during the pandemic; and the adherence of remote, digitally enrolled participants. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/3258

    Energy detection based cooperative spectrum sensing system for emergency networks

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    During emergencies, a number of rescue teams come to the field and setup their own radio communication systems. If the deployed communication setup does not coordinate among themselves properly, they may interfere with each other when using the same RF channels known as co-channel interference. Spectrum sensing is the most important and complex job for cognitive radios. Cooperation among cognitive radio nodes is needed to enhance the sensing performance. In this paper, we present an experimental study of this solution. A Software Defined Radio comprising of GNU Radio and USRP were used to capture the signal samples to build a database profile of the spectrum condition. MATLAB communications toolbox was used to analyze the data and examine the spectrum pertaining to the condition in emergency networks. The benefits of cooperative spectrum sensing in avoiding co-channel interference during emergency situations are illustrated. Cooperation among cognitive spectrum sensing nodes operating at the same frequency improves the probability of detection, and the overall efficiency of the system. Results show that the cooperative sensing scheme outperforms the individual sensing approach. It can increases the probability of detection relative to the collected samples as the key performance indicator

    Síntesis de ésteres de acetato hexilo, mediante transesterificación química a partir de palma como base sintética de fluidos para sondeos

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    In the present study the synthesis of a palm based ethylhexyl ester was examined through a transesterification reaction of palm oil methyl ester (POME) with 2-ethylhexanol (EH). A sodium methoxide in methanol solution was used as a catalyst. The reaction was carried out at a fixed pressure of 1.5 mbar by varying the temperature (80–140 °C), POME/2EH molar ratio (1:1.5–1:2.2), reaction time (0.5–4 h) and catalyst concentration (1–2% w/w). The reaction with 2-ethylhexanol involved a single step reversible reaction, thus, the reaction was completed in a very short time. The optimum conditions were obtained in less than 30 minutes with 1.5 mbar pressure, 70 °C, and 1:2 molar ratio of POME to 2EH. The analysis of the final product (ethylhexyl ester) was performed using gas chromatography which exhibited 98% of ethyl hexyl ester yield. The gas chromatography analysis of ethyl hexyl ester revealed two major esters peaks i.e. ethyl hexyl palmitate and ethylhexyl oleate.En el presente estudio se analizó la síntesis de ésteres de acetato de hexilo de palma mediante reacción de transesterificación de los ésteres metílicos de aceite de palma (PME) con 2-etilhexanol (EH). Como catalizador se utiliza una solución de metóxido de sodio en metanol. La reacción se lleva a cabo a presión fija de 1,5 mbar mediante la variación de temperatura (80–140 °C), relación molar POME/2EH (1:1.5–1:2.2), tiempo de reacción (0,5–4 h) y concentración de catalizador (1–2% w / w). La reacción con 2-etilhexanol implica un solo paso de una reacción reversible, por lo tanto, ésta se completa en un tiempo muy corto. Las condiciones óptimas se obtuvieron en menos de 30 min a 1,5 mbar, 70 °C y una relación molar de 1:2 de POME al 2EH. El análisis del producto final se realizó usando cromatografía de gases que mostró un rendimiento del 98% del etilhexil éster. El análisis de la cromatografía de gases del etilhexil éster muestra dos grandes picos correspondientes a los ésteres palmitato y oleato de etilhexilo

    Patterned silicon substrates: a common platform for room temperature GaN and ZnO polariton lasers

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    A new platform for fabricating polariton lasers operating at room temperature is introduced: nitride-based distributed Bragg reflectors epitaxially grown on patterned silicon substrates. The patterning allows for an enhanced strain relaxation thereby enabling to stack a large number of crack-free AlN/AlGaN pairs and achieve cavity quality factors of several thousands with a large spatial homogeneity. GaN and ZnO active regions are epitaxially grown thereon and the cavities are completed with top dielectric Bragg reflectors. The two structures display strong-coupling and polariton lasing at room temperature and constitute an intermediate step in the way towards integrated polariton devices

    Chemical and biological investigations of Delonix regia (Bojer ex Hook.) Raf.

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    U radu je opisana izolacija pet sastojaka petroleterske i diklormetanske frakcije metanolnog ekstrakta kore biljke Delonix regia: lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) i p-metoksibenzaldehid (5). Nadalje, testirano je antimikrobno djelovanje različitih ekstrakata difuzijskom metodom na disku (15 μg mm2). Zone inhibicije za sastojke topljive u petroleteru, tetraklormetanu i diklormetanu bile su 914 mm, 1113 mm, odnosno 920 mm, dok je zona inhibicije standarda kanamicina bila 2025 mm. U biološkom pokusu smrtnosti morskih kozica najveću toksičnost pokazali su spojevi topljivi u tetraklormetanu (LC50 = 0,83 μg mL1), dok je topljivost sastojaka topljivih u petroleteru i diklormetanu bila LC50 14,94, odnosno 3,29 μg mL1, a standarda vinkristin sulfata 0,812 μg mL1. Ovo je prvo izvješće o izolaciji sastojaka, antimikrobnom djelovanju i citotoksičnosti biljke D. regia.In this study five compounds, lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) and p-methoxybenzaldehyde (5) were isolated from the petroleum ether and dichloromethane fractions of a methanolic extract of the stem bark of Delonix regia. Antimicrobial screening of the different extracts (15 μg mm2) was conducted by disc diffusion method. The zones of inhibition demonstrated by the petroleum ether, carbon tetrachloride and dichloromethane fractions ranged from 914 mm, 1113 mm and 920 mm, respectively, compared to kanamycin standard with the zone of inhibition of 2025 mm. In brine shrimp lethality bioassay, the carbon tetrachloride soluble materials demonstrated the highest toxicity with LC50 of 0.83 μg mL1, while petroleum ether and dichloromethane soluble partitionates of the methanolic extract revealed LC50 of 14.94 and 3.29 μg mL1, respectively, in comparison with standard vincristine sulphate with LC50 of 0.812 μg mL1. This is the first report on compounds separation from D. regia, their antimicrobial activity and cytotoxicity
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