2,108 research outputs found

    Fluctuation Scaling, Taylor’s Law, and Crime

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    Fluctuation scaling relationships have been observed in a wide range of processes ranging from internet router traffic to measles cases. Taylor’s law is one such scaling relationship and has been widely applied in ecology to understand communities including trees, birds, human populations, and insects. We show that monthly crime reports in the UK show complex fluctuation scaling which can be approximated by Taylor’s law relationships corresponding to local policing neighborhoods and larger regional and countrywide scales. Regression models applied to local scale data from Derbyshire and Nottinghamshire found that different categories of crime exhibited different scaling exponents with no significant difference between the two regions. On this scale, violence reports were close to a Poisson distribution (α = 1.057±0.026) while burglary exhibited a greater exponent (α = 1.292±0.029) indicative of temporal clustering. These two regions exhibited significantly different pre-exponential factors for the categories of anti-social behavior and burglary indicating that local variations in crime reports can be assessed using fluctuation scaling methods. At regional and countrywide scales, all categories exhibited scaling behavior indicative of temporal clustering evidenced by Taylor’s law exponents from 1.43±0.12 (Drugs) to 2.094±0081 (Other Crimes). Investigating crime behavior via fluctuation scaling gives insight beyond that of raw numbers and is unique in reporting on all processes contributing to the observed variance and is either robust to or exhibits signs of many types of data manipulation

    High-Sensitivity Magnetic Sensors Based on GMI Microwire-SAW IDT Design

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    This work presents a design approach for a highly sensitive, miniaturized magnetic sensor. The design makes use of GMI microwires and a multi-electrode SAW IDT. The use of SAW IDTs allows for the magnetic effect of the GMI microwire to be measured through the transduction process. This approach permits simultaneous measurement at different frequencies of operation, enabling highly sensitive measurement over a wide range of magnetic fields. This technique may find application in magnetic sensing for non-invasive battery SOC measurement

    Efficient Cell Phone Keypad Designing for Bangla SMS Using English Alphabets

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    Mobile phone networks are increasingly supporting the transmission of textual message between individuals. In this paper we have introduced a new approach that will enhance the speed of typing process in Bangla by using English mobile keypad. An example of making Bangla sentences using English keypad could be “Ami valo achiâ€. Traditional cell phone keypad is not suitable for Bangla typing using English alphabets and number of key pressing is high to make such Bangla SMS (Short Message Service). The proposed approach has been explored to speed up the typing process in Bangla using English alphabets. The alphabets are rearranged according to the priority of frequencies. The frequency of alphabet is appeared by most used letter in SMS. The letters which are mostly used are recognized as higher frequency. The proposed design consumes less time for typing Bangla SMS using English letter format. Keywords: Mobile keypad, unitap, multitap, Bangla SMS, frequency

    Analysis of Dual Core Hexagonal PCF Based Polarization Beam Splitter

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    In this research work an analysis has been carried out on symmetric dual core hexagonal PCF-based polarization beam splitter by using finite element method (FEM). The splitter designs are carried out with hexagonal PCFs with simple symmetric design by varying only air holes diameter. The results of numerical calculation show that coupling lengths are higher for polarization splitters with larger air hole diameters and with the increase of operating wavelength coupling length decreases. Furthermore it is possible to obtain an 8.4 mm-long polarization beam splitter with high extinction ratio (250dB). This study will be very helpful to design and manufacture simple PCF based splitters with better performance. Keywords: photonic crystal fiber (PCF), finite element method (FEM), polarization beam splitter, birefringence, extinction ratio, coupling lengt

    Survey and scientific evaluation of medicinal plants used by the Pahan and Teli tribal communities of Natore district, Bangladesh

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    The Pahans and the Telis are two of the smallest indigenous communities in Bangladesh. The Pahans, numbering about 14,000 people are widely scattered in several northern districts of the country, while the Telis are such a small community that nothing has been reported on their numbers and lifestyle. Both tribes are on the verge of disappearance. One each of the Pahan and the Teli community was located after much search in two adjoining villages of Natore district, Bangladesh. Since the tribes were found to still depend on their traditional medicinal practitioners for treatment of ailments, it was the objective of the present study to document their traditional usage of medicinal plants and to evaluate such plants against modern research-based pharmacological activity studies on these plants. Interviews were conducted of the practitioners of the Pahan and Teli community of Natore district with the help of a semi-structured questionnaire and using the guided field-walk method. Plant specimens aspointed out by the practitioners were collected and pressed on the field and identification completed at the Bangladesh National Herbarium. The Pahan tribal practitioners used 13 plants distributed into 9 families for treatment of 14 different ailments. The Teli tribal practitioner used 15 plants divided into 14 families for treatment of 17 different ailments. Eight out of the thirteen plants used by the Pahan tribal practitioner (61.5%) had reported relevant pharmacological activities in the scientific literature, while six out of the fifteen plants used by the Teli tribal practitioners (40%) had such relevant pharmacological activities in accordance with their usage. The medicinal plants used by the Pahans and Telis warrant further scientific studies toward discovery of lead compounds and efficacious drugs and the documentation and protection of the traditional medical knowledge held by these tribes

    Molecular characterization and resistance profile of nosocomial Acinetobacter baumannii in intensive care unit of tertiary care hospital in Bangladesh

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    This study was designed to investigate the resistance profile along with the genetic background of resistance to beta-lactam antibiotics among the nosocomial A. baumannii in Bangladesh. A. baumannii was confirmed by detecting blaOXA-51-like. Antibiotic susceptibility was determined by disk diffusion method. Agar dilution method was used to determine MIC of ceftazidime and imipenem. All A. baumannii were phenotypically screened for ampC, ESBL and MBL production. Genetic markers of antibiotic resistance such as blaampC, blaOXA-51, 23, 40, 58 and 143, blaKPC, blaIMP, blaVIM and blaNDM-1, genetic environment around blaADC and ISAba1 upstream of blaOXAs were evaluated by PCR. Twenty-four (96%) A. baumannii were considered as MDR. 96% A. baumannii were resistant to amoxiclav, ceftazidime, ciprofloxacin and cefoxitin, 92% to cefotaxime and piperacillin-tazobactam, 88% to cefepime, amikacin and imipenem, 52% to sulbactam-cefoperazone and 40% were resistant to aztreonam. All were sensitive to colistin. The distribution of several beta-lactamase genes such as blaOXA-51 (100%), blaADC-like (92%), blaNDM-1 (92%), EBC group (84%), blaOXA-23 (76%), blaVIM (72%), blaKPC (44%), DHA group (24%), blaOXA-58 (16%), ACC group (8%) and CIT group (4%) were observed among the 25 A. baumannii. This is the first reported plasmid mediated ampC beta-lactamases in A. baumannii. blaOXA-51 was positive in 100%, blaNDM-1 in 95.45%, blaOXA-23 in 77.27%, blaVIM in 72.73%, blaKPC in 50% and blaOXA-58 in 18.18% of imipenem resistant isolates. MDR profile of nosocomial A. baumannii would highlight the importance of standard guideline of antimicrobials use and infection control policy in the hospitals of Bangladesh.</jats:p

    TCP throughput optimization over 802.11 MAC protocol in multi-hop ad-hoc networks.

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    The acknowledgment strategy has great potential to increase the TCP throughput when it runs over 802.11 MAC protocol. In particular TCP acknowledgments carry out an extensive number of medium accesses as they compete in the same route as data packets for media. As the load increases, the well-known hidden terminal effects caused by interference between ACK and data packets in MAC layer can degrade TCP performance dramatically if TCP acknowledges every incoming data packets. In this paper, we propose a TCP-MAC interaction strategy which tries to reduce the number of induced ACKs by monitoring the channel condition. To this end, the total collision probability collected along the path in MAC layer is used to properly set the number of the delayed ACKs in TCP. Based on the measured collision probability, TCP sender dynamically adjusts itself to the channel condition by delaying less ACKs in high traffics and more in low traffic conditions. The simulation results show a reasonable tradeoff between performance under moderate and high traffics

    Prevalence of subclinical cardiac abnormalities in patients with metal-on-metal hip replacements

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    Background Metal-on-metal (MOM) hip prostheses have a higher failure rate than conventional prostheses and leaching of cobalt and chromium has been linked to cardiomyopathy. We screened MOM subjects to evaluate if cobalt and chromium are related to subclinical cardiac dysfunction. Methods A single centre, non-randomised, observational study using echocardiography in 95 patients who had undergone MOM hip prostheses, and 15 age matched controls with non-MOM hip replacement. Serial plasma cobalt and chromium levels were recorded, and data compared by tertiles of cobalt exposure. Results Indexed left ventricular (LV) end-diastolic and end-systolic volumes (EDVi and ESVi) increased with tertile of cobalt (omnibus p = 0.003 for EDVi and ESVi), as did indexed left atrial (LA) volumes (p = 0.003). MOM subjects had 25% larger EDVi than controls, 32% larger ESVi (40 ml vs. 32 ml, and 15 ml vs. 11 ml, p = 0.003 for both) and 28% larger indexed LA (23 ml vs. 18 ml, p = 0.002). There were no differences in LV systolic or diastolic function, including ejection fraction, tissue velocity and mitral E/e′. Estimated glomerular filtration rate was 18% lower in the highest tertile compared with the lowest (p = 0.01) and correlated inversely with LA volume (r = −0.36, p < 0.001) and LV EDV (r = −0.24, p = 0.02). Conclusions No correlations between sensitive measures of systolic or diastolic cardiac function or serum cobalt/chromium levels were observed in this study. However, there was a relationship between increasing left ventricular and left atrial volumes and declining renal function with high cobalt levels which requires further evaluation in MOM patients

    Rice diversity and the joy of eid

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    This brief presents the results of research on the conservation and sustainable use of rice diversity in Bangladesh and how the rice varieties used and planted are intrinsically linked to religious festivals, food culture, land morphology and the climate that shape rice farming/cropping in this region. It highlights the important roles played by Community Seed Wealth Centers (community seed banks) and the Nayakrishi farmers, who manage them, in ensuring the conservation of rice varieties that are in danger of disappearing, and in supplying farmers with diverse, good quality seed. It also demonstrates the key roles played by women farmers as seed custodians and the strategic research and capacity building activities carried out by the Community Seed Wealth Centers

    Thromboinflammatory changes in plasma proteome of pregnant women with PCOS detected by quantitative label-free proteomics

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    Polycystic ovary syndrome (PCOS) is the most common endocrinological disorder of fertile-aged women. Several adverse pregnancy outcomes and abnormalities of the placenta have been associated with PCOS. By using quantitative label-free proteomics we investigated whether changes in the plasma proteome of pregnant women with PCOS could elucidate the mechanisms behind the pathologies observed in PCOS pregnancies. A total of 169 proteins with >= 2 unique peptides were detected to be differentially expressed between women with PCOS (n = 7) and matched controls (n = 20) at term of pregnancy, out of which 35 were significant (p-value <0.05). A pathway analysis revealed that networks related to humoral immune responses, inflammatory responses, cardiovascular disease and cellular growth and proliferation were affected by PCOS. Classification of cases and controls was carried out using principal component analysis, orthogonal projections on latent structure-discriminant analysis (OPLS-DA), hierarchical clustering, self-organising maps and ROC-curve analysis. The most significantly enriched proteins in PCOS were properdin and insulin-like growth factor II. In the dataset, properdin had the best predictive accuracy for PCOS (AUC=1). Additionally, properdin abundances correlated with AMH levels in pregnant women.Peer reviewe
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