Immigrant networks and their implications for occupational choice and wages

This paper employs United States Census data to study the occupational allocation of immigrants. The data reveal that the occupational shares of various ethnic groups have grown drastically in regional labor markets over the period 1980 to 2000. We examine the extent to which this growth can be attributed to network effects. That is, we examine the relationship between the occupational choice decision of recently arrived immigrants with those of established immigrants from the same country. We also consider the earnings implications of these immigrant networks for recent arrivals. The empirical evidence strongly suggests the operation of networks in the immigrant labor market. First, we find evidence that new arrivals are locating in the same occupations as their countrymen. Moreover, this location decision is operating at the level of regional labor markets. Second, we find that individuals who locate in the popular occupations of their countrymen enjoy a large and positive effect on their hourly wage and their level of weekly earnings

Leptonic decay of Heavy-light Mesons in a QCD Potential Model

We study the masses and decay constants of heavy-light flavour mesons D, Ds, B and Bs in a QCD Potential model. The mesonic wavefunction is used to compute the masses of D and B mesons in the ground state and the wavefunction is transformed to momentum space to estimate the pseudoscalar decay constants of these mesons. The leptonic decay widths and branching ratio of these mesons for different leptonic channels are also computed to compare with the experimental values. The results are found to be compatible with available data.Comment: 9 pages,3 table

A survey of patient acceptance of resect and discard for diminutive polyps

Background and Aims Resect and discard is a new paradigm for management of diminutive colon polyps. Little is known regarding whether patients would accept resect and discard. We surveyed colonoscopy patients and their drivers regarding acceptance of resect and discard. Methods This was a cross-sectional survey of colonoscopy outpatients and their drivers at two outpatient academic endoscopy centers. Results Four hundred fifteen colonoscopy patients and 293 drivers completed the survey (93.5% of all invited participants). Results for the two groups were similar. Overall, 66.3% indicated they would accept resect and discard. Participants who were younger, white, and seen at the ambulatory surgery center (vs the hospital outpatient department) were more likely to accept. Those declining resect and discard were more likely to be willing to pay some amount out-of-pocket to have diminutive polyps checked by pathology (97.1% vs 44.5%). Of those unwilling to accept resect and discard, 49.8% would require a zero chance of cancer in diminutive polyps before accepting resect and discard. Conclusions Patient acceptance of resect and discard appears promising but is quite variable. Eliciting individual patient acceptance of resect and discard will be important during initial implementation into clinical practice

Matlab Simulation of Single Phase Shunt Active Filter Based on PQ Theory

ABSTRACT- This paper presents the simulation of single phase shunt active filter based on PQ theory. Generally PQ theory is used for 3 phases 3 wires or 3 phases 4 wire system but here it is used for single phase system. This paper also concentrates hardly on reduction of THD of load current. Since the system has only single phase signal for both voltage and current, thus the dummy signal with 120 º different angels must be generated for input of the p-q theory. During simulation the six pulses will be generated for switching of IGBT but only two will be used. MATLAB/SIMULINK power system toolbox is used to simulate the proposed system

Oscillation frequency of B and B mesons in a QCD potential model with relativistic effect

Wavefunction at the origin with the incorporation of relativistic effect leads to singularity in a specific potential model. To regularise the wavefunction, we introduce a short distance scale here and use it to estimate masses and decay constants of Bd and Bs mesons within the QCD potential model.These values are then used to compute the oscillation frequency \Delta mB of Bd and Bs mesons. The values are found to be in good agreement with experiment and other theoretical values.Comment: 10 page

Predicting invasive fungal disease due to Candida species in non-neutropenic, critically ill, adult patients in United Kingdom critical care units

Background Given the predominance of invasive fungal disease (IFD) amongst the non-immunocompromised adult critically ill population, the potential benefit of antifungal prophylaxis and the lack of generalisable tools to identify high risk patients, the aim of the current study was to describe the epidemiology of IFD in UK critical care units, and to develop and validate a clinical risk prediction tool to identify non-neutropenic, critically ill adult patients at high risk of IFD who would benefit from antifungal prophylaxis. Methods Data on risk factors for, and outcomes from, IFD were collected for consecutive admissions to adult, general critical care units in the UK participating in the Fungal Infection Risk Evaluation (FIRE) Study. Three risk prediction models were developed to model the risk of subsequent Candida IFD based on information available at three time points: admission to the critical care unit, at the end of 24 h and at the end of calendar day 3 of the critical care unit stay. The final model at each time point was evaluated in the three external validation samples. Results Between July 2009 and April 2011, 60,778 admissions from 96 critical care units were recruited. In total, 359 admissions (0.6 %) were admitted with, or developed, Candida IFD (66 % Candida albicans). At the rate of candidaemia of 3.3 per 1000 admissions, blood was the most common Candida IFD infection site. Of the initial 46 potential variables, the final admission model and the 24-h model both contained seven variables while the end of calendar day 3 model contained five variables. The end of calendar day 3 model performed the best with a c index of 0.709 in the full validation sample. Conclusions Incidence of Candida IFD in UK critical care units in this study was consistent with reports from other European epidemiological studies, but lower than that suggested by previous hospital-wide surveillance in the UK during the 1990s. Risk modeling using classical statistical methods produced relatively simple risk models, and associated clinical decision rules, that provided acceptable discrimination for identifying patients at ‘high risk’ of Candida IFD

Optimized mosquito surveillance in St. Tammany's Parish, LA

Since its emergence in the United States in 1999, West Nile Virus has caused hundreds of deaths and has been spreading geographically. In order to efficiently control West Nile Virus outbreaks, it is necessary to monitor the spread of its primary mosquito vectors. This report contains a new computational method to optimize the surveillance methods of West Nile Virus vectors at St. Tammany Parish, Louisiana. Based on multiple years of data, the distribution of mosquito density was thoroughly anazlyed. The results include the identification of multi-year patterns and high-risk zones for West Nile Virus in the parish and correlations in mosquito prevalence across these zones. A spatial statistical model was developed for the surveillance network regarding the West Nile Virus vector Culex Quinquefasciatus. An approximation algorithm was applied to determine the optimal location of surveillance sites that provide the most informative locations for Culex Quinquefasciatus surveillance in the parish. The results of this paper indicate that a greedy algorithm, thus far, is the best possible solution to determine the optimal surveillance sites. In its current state, the algorithm is simplified as the most informative locations as those that decrease the variance the most. An improved algorithm involving more variables such as rainfall will enhance the ability to determine an optimal mosquito surveillance network. Optimizing mosquito surveillance methods can improve the ability to monitor mosquito vectors and significantly reduce costs.Mathematic

Total Solar Eclipse

Our mission objective was to capture the total solar eclipse that occurred on August 21, 2017. To assemble all the payloads (video, still image and Iridium) and the ground station tracking system. To determine and implement the pointing solutions for the video camera to point the sun. To stabilize the structure of the payload, preventing it from twisting/rotating

Comparative Analysis of Machine Learning Models for Detecting Fake Reviews on Amazon

This research is concerned with the efficiency of machine learning models when it comes to detecting fake reviews on Amazon. Since or because of the rapid growth of e-commerce, online reviews have become important in determinations of consumer decisions. But the growing trend of fake reviews erodes the trust of the consumers and alters the behavior of the market. There are various evaluations of machine learning algorithms: Logistic Regression, Support Vector Machines (SVM), Random Forest, and Gradient Boosting among others to establish the most effective and reliable model for detection of fake reviews. This study uses a publicly available dataset of Amazon product reviews identified as either genuine or fake, which contains text data as well as metadata on reviewers. Before training the models, methods of data preprocessing are applied, including the text cleaning, tokenization, and feature extraction. Performance evaluation is done based on the metrics of accuracy, precision, recall, and F1 score. Results reveal that the ensemble methods such as Random Forest, and Gradient Boosting classifiers perform better than other models in terms of recall as well as overall classification performance. The study identifies the issues with processing imbalanced datasets and points to its importance to pay attention to model transparency and interpretability. Lastly, the research offers recommendations to e-commerce platforms in order to increase the review credibility and safeguard consumer trust