Resonant tunneling through ultrasmall quantum dots: zero-bias anomalies, magnetic field dependence, and boson-assisted transport

We study resonant tunneling through a single-level quantum dot in the presence of strong Coulomb repulsion beyond the perturbative regime. The level is either spin-degenerate or can be split by a magnetic field. We, furthermore, discuss the influence of a bosonic environment. Using a real-time diagrammatic formulation we calculate transition rates, the spectral density and the nonlinear $I-V$ characteristic. The spectral density shows a multiplet of Kondo peaks split by the transport voltage and the boson frequencies, and shifted by the magnetic field. This leads to zero-bias anomalies in the differential conductance, which agree well with recent experimental results for the electron transport through single-charge traps. Furthermore, we predict that the sign of the zero-bias anomaly depends on the level position relative to the Fermi level of the leads.Comment: 27 pages, latex, 21 figures, submitted to Phys. Rev.

Zero-bias anomalies and boson-assisted tunneling through quantum dots

We study resonant tunneling through a quantum dot with one degenerate level in the presence of a strong Coulomb repulsion and a bosonic environment. Using a real-time approach we calculate the spectral density and the nonlinear current within a conserving approximation. The spectral density shows a multiplet of Kondo peaks split by the transport voltage and boson frequencies. As a consequence we find a zero-bias anomaly in the differential conductance which can show a local maximum or minimum depending on the level position. The results are compared with recent experiments.Comment: 4 pages, revtex, 5 postscript figures, submitted to Phys. Rev. Let

A STUDY OF SWEAR WORDS IN MADURESE LANGUAGE AMONG COASTAL TEENAGERS OF MADURA

This study examines the types and functions of Madurese swearing language among coastal teenagers in Madura, particularly students at SMKN 1 Sepulu, Bangkalan Regency. Using a sociolinguistic approach and Hughes' (2006) and Andersson & Trudgill's (1990) theories, this qualitative study identifies six swearing categories, with general terms being the most common. Swearing functions include expressing emotions, building solidarity, and demonstrating peer closeness. The findings enrich the understanding of swearing's social roles among coastal Madurese teenagers

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

PROBLEMATICS OF BIPA LEARNERS LEARNING CULTURE IN ELECTIVE CLASSES

This research aims to analyze the problems faced by BIPA students in learning culture in elective classes. This research uses qualitative method with descriptive research type. The results of this research show several things that become obstacles for foreign students in learning other cultures, namely the difficulty level of teaching materials, inadequate facilities and infrastructure, and cultural differences

Design and Experiments of Low Cost Teleoperation System

In this work, a teleoperation system consists of two planar SCARA manipulators is developed. The manipulators are constructed using basic low cost aluminum bars as well as cheap electronic circuitry and software. Modeling, system identification, individual control and teleoperation control are proposed. Finally, experiments are also performed to verify the effectiveness of the design.Index Terms—Teleoperation systems, PID control, System identification, position control.DOI: http://dx.doi.org/10.11591/ijra.v1i1.27

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Predictive model for heat stress-related symptoms among steel mill workers in East Java, Indonesia

Introduction: As a tropical country, Indonesia’s climate is hot and humid throughout the year, implicating hot workplace environment and leading to workers’ susceptibility to heat stress exposure. Workers at a steel processing mills exposed to an extremely hot environment are prone to experience heat stress-related symptoms caused by occupational heat stress. Methods: The study aimed to build a predictive model of heat stress-related symptoms in steel mill workers based on physiological and environmental parameters. The respondents of this study were 119 operators exposed to a hot workplace in Surabaya, Sidoarjo, and Gresik, East Java, Indonesia. Results: The result as a high correlation (p<0.05) in predictive between the model Wet Bulb Globe Temperature (WBGT), core body temperature, heart rate and heat stress-related symptoms with R-value of 0.78 or 78. In addition, there is a weak correlation between heat stress symptoms and systolic and diastolic blood pressure, as well as humidity factors and heat stress-related symptoms. Heat stress-related symptoms have a linear correlation with the value of WBGT, body core temperature and heart rate, while body core temperature has the highest value of correlation and WBGT is attributed to the lowest of all to the heat stress-related symptoms. Conclusion: With these values in hand, ones can predict whether workers will be exposed to heat stress work environment. Furthermore, with this model, it can predict heat stress-related symptoms in a particular workplace

Unipolar versus bipolar hemiarthroplasty for displaced femoral neck fractures: A pooled analysis of 30,250 participants data

PURPOSE: To assess the clinical outcomes of unipolar versus bipolar hemiarthroplasty for displaced intracapsular femoral neck fractures in older patients and to report whether bipolar implants yield better long-term functional results. METHODS: We searched PubMed, Scopus, EBSCO, and Cochrane Library for relevant randomized clinical trials (RCTs) and observational studies, comparing unipolar and bipolar hemiarthroplasty. Data were extracted from eligible studies and pooled as relative risk (RR) or mean difference (MD) with corresponding 95% confidence intervals (CI) using RevMan software for Windows. RESULTS: A total of 30 studies were included (13 RCTs and 17 observational studies). Analyses included 30,250 patients with a mean age of 79 years and mean follow-up time of 24.6 months. The overall pooled estimates showed that bipolar was superior to unipolar hemiarthroplasty in terms of hip function, range of motion and reoperation rate, but at the expense of longer operative time. In the longer term the unipolar group had higher rates of acetabular erosion compared to the bipolar group. There was no significant difference in terms of hip pain, implant related complications, intraoperative blood loss, mortality, six-minute walk times, medical outcomes, and hospital stay and subsequently cost. CONCLUSIONS: Bipolar hemiarthroplasty is associated with better range of motion, lower rates of acetabular erosion and lower reoperation rates compared to the unipolar hemiarthroplasty but at the expense of longer operative time. Both were similar in terms of mortality, and surgical or medical outcomes. Future large studies are recommended to compare both methods regarding the quality of life

The effect of type of femoral component fixation on mortality and morbidity after hip hemiarthroplasty:A systematic review and meta-analysis

Background: Hip hemiarthroplasty is a well-established treatment of displaced femoral neck fracture, although debate exists over whether cemented or uncemented fixation is superior. Uncemented prostheses have typically been used in younger, healthier patients and cemented prostheses in older patients with less-stable bone. Also, earlier research has suggested that bone cement has cytotoxic effects and may trigger cardiovascular and respiratory adverse events. Questions/Purposes: The aim of this systematic review and meta-analysis was to compare morbidity and mortality rates after cemented and uncemented hemiarthroplasty for the treatment of displaced femoral neck fractures in elderly patients. Methods: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched seven medical databases for randomized clinical trials and observational studies. We compared cemented and uncemented hemiarthroplasty using the Harris Hip Score (HHS), as well as measures of postoperative pain, mortality, and complications. Data were extracted and pooled as risk ratios or standardized mean difference with their corresponding 95% confidence intervals in a meta-analysis model. Results: The meta-analysis included 34 studies (12 randomized trials and 22 observational studies), with a total of 42,411 patients. In the pooled estimate, cemented hemiarthroplasty was associated with less risk of postoperative pain than uncemented hemiarthroplasty. There were no significant differences between groups regarding HHS or rates of postoperative mortality, pulmonary embolism, cardiac arrest, myocardial infarction, acute cardiac arrhythmia, or deep venous thrombosis. Conclusions: While we found that cemented hemiarthroplasty results in less postoperative pain than uncemented hemiarthroplasty in older patients with femoral neck fracture, the lack of significant differences in functional hip scores, mortality, and complications was surprising. Further high-level research is needed