300 research outputs found

    Method and system of doppler correction for mobile communications systems

    Get PDF
    Doppler correction system and method comprising receiving a Doppler effected signal comprising a preamble signal (32). A delayed preamble signal (48) may be generated based on the preamble signal (32). The preamble signal (32) may be multiplied by the delayed preamble signal (48) to generate an in-phase preamble signal (60). The in-phase preamble signal (60) may be filtered to generate a substantially constant in-phase preamble signal (62). A plurality of samples of the substantially constant in-phase preamble signal (62) may be accumulated. A phase-shifted signal (76) may also be generated based on the preamble signal (32). The phase-shifted signal (76) may be multiplied by the delayed preamble signal (48) to generate an out-of-phase preamble signal (80). The out-of-phase preamble signal (80) may be filtered to generate a substantially constant out-of-phase preamble signal (82). A plurality of samples of the substantially constant out-of-phase signal (82) may be accumulated. A sum of the in-phase preamble samples and a sum of the out-of-phase preamble samples may be normalized relative to each other to generate an in-phase Doppler estimator (92) and an out-of-phase Doppler estimator (94)

    Pre-operative bladder irrigation with 1% Povidone iodine in reducing open prostatectomy surgical site infection (SSI) at university teaching hospital, Lusaka

    Get PDF
    Purpose: The aim of the study is to assess the effectiveness of using preoperative bladder irrigation with 1% povidone iodine in reducing post transvesical prostatectomy surgical site infections. Study design: This was a prospective randomized cohort study with blinding of patients and outcome adjudicator regarding group assignments.Methodology: One hundred and thirty patients were recruited from the waiting list of Urology unit II in the department of surgery during the period between July 2011 to December 2012. The non-probability convenience sampling technique was used. Any consenting patient who presented to the department of surgery for open prostatectomy and fulfills the inclusion criteria was selected. The patients were randomly allocated to each of the two groups. Each group had 65 patients. Patients in the study group had their bladder irrigated with 1% 50cc povidoneiodine which was drained upon opening the bladder followed by enucleating the adenomatous prostate gland. Hemostasis was ensured and a 3 way Foley's catheter inserted via the urethral into the bladder and ballooned appropriately for draining and irrigation. The bladder was sutured in 2 layers using 0 or 1 chromic catgut. In the control group povidone-iodine was not used. Both groups received pre-operative antibiotics 30 minutes before incision and post-operative for 5 days. Pre-operative, intraoperative and post-operative data were collected on a standardized data collection forms. Post-operative irrigation was done for 9 to 12 days after which the catheter was removed as an outpatient. Patients were followed up in the urological clinic at 1 week, 2weeks and at 4 weeks post-operatively to assess whether they had developed surgical site infections according to CDC guidelines. Data was analyzed using SPSS version 16.Results: The patients mean age was 71.1 in the control group and 71.4 in the study group with no statistically significant difference (t=0.318; p=0.75; df=126.89). The overall surgical infection rate was 16.2%. In the control group 15 out of 65 patients (23.1%) developed SSIs. While in the study group 6 out of 65 patients (9.2%) developed SSIs. The difference in the rates of SSI between the two groups was statistically significant (÷²; p<0.05; df=126.89) Escherichia coli was the most predominant organism 13/37 (35%), streptococcus 7/37 (18.9), Citrobacter koseri 5/37 (13.5%), Klebsiella sp 4/37 (10.8%). Escherichia coli, Streptococcus and Citrobacter were sensitive to ciprofloxacin; Pantoea agglomerans was sensitive to ceftazidime while Staphylococcus coagulase was sensitive to imipenem. Enterobacter cloace was resistant to all antibiotics used.Conclusion: The study found that irrigating the bladder with 1% povidone-iodine resulted in significant reduction in post prostatectomy surgical site infection, Escherichia coli as the most common causative organism, reduced morbidity and post-operative hospital stay in the povidone iodine group.Key words: Benign prostatic hyperplasia, transvesical prostatectomy, povidone iodine, surgical site infections

    Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts.

    Get PDF
    The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes

    Scaling properties of driven interfaces in disordered media

    Full text link
    We perform a systematic study of several models that have been proposed for the purpose of understanding the motion of driven interfaces in disordered media. We identify two distinct universality classes: (i) One of these, referred to as directed percolation depinning (DPD), can be described by a Langevin equation similar to the Kardar-Parisi-Zhang equation, but with quenched disorder. (ii) The other, referred to as quenched Edwards-Wilkinson (QEW), can be described by a Langevin equation similar to the Edwards-Wilkinson equation but with quenched disorder. We find that for the DPD universality class the coefficient λ\lambda of the nonlinear term diverges at the depinning transition, while for the QEW universality class either λ=0\lambda = 0 or λ0\lambda \to 0 as the depinning transition is approached. The identification of the two universality classes allows us to better understand many of the results previously obtained experimentally and numerically. However, we find that some results cannot be understood in terms of the exponents obtained for the two universality classes {\it at\/} the depinning transition. In order to understand these remaining disagreements, we investigate the scaling properties of models in each of the two universality classes {\it above\/} the depinning transition. For the DPD universality class, we find for the roughness exponent αP=0.63±0.03\alpha_P = 0.63 \pm 0.03 for the pinned phase, and αM=0.75±0.05\alpha_M = 0.75 \pm 0.05 for the moving phase. For the growth exponent, we find βP=0.67±0.05\beta_P = 0.67 \pm 0.05 for the pinned phase, and βM=0.74±0.06\beta_M = 0.74 \pm 0.06 for the moving phase. Furthermore, we find an anomalous scaling of the prefactor of the width on the driving force. A new exponent φM=0.12±0.06\varphi_M = -0.12 \pm 0.06, characterizing the scaling of this prefactor, is shown to relate the values of the roughnessComment: Latex manuscript, Revtex 3.0, 15 pages, and 15 figures also available via anonymous ftp from ftp://jhilad.bu.edu/pub/abms/ (128.197.42.52

    Knowledge, Practice, and Attitudes of Physicians in Low- and Middle-Income Countries on Fertility and Pregnancy-Related Issues in Young Women With Breast Cancer

    Get PDF
    PURPOSE Fertility and pregnancy-related issues are highly relevant for young (≤ 40 years) patients with breast cancer. Limited evidence exists on knowledge, practice, and attitudes of physicians from low- and middle-income countries (LMICs) regarding these issues. METHODS A 19-item questionnaire adapted from an international survey exploring issues about fertility preservation and pregnancy after breast cancer was sent by e-mail between November 2019 and January 2020 to physicians from LMICs involved in breast cancer care. Descriptive analyses were performed. RESULTS A total of 288 physicians from Asia, Africa, America, and Europe completed the survey. Median age was 38 years. Responders were mainly medical oncologists (44.4%) working in an academic setting (46.9%). Among responders, 40.2% and 53.8% reported having never consulted the available international guidelines on fertility preservation and pregnancy after breast cancer, respectively. 25.0%, 19.1%, and 24.3% of responders answered to be not at all knowledgeable about embryo, oocyte, or ovarian tissue cryopreservation, respectively; 29.2%, 23.6%, and 31.3% declared that embryo, oocyte, and ovarian tissue cryopreservation were not available in their countries, respectively. 57.6% of responders disagreed or were neutral on the statement that controlled ovarian stimulation can be considered safe in patients with breast cancer. 49.7% and 58.6% of responders agreed or were neutral on the statement that pregnancy in breast cancer survivors may increase the risk of recurrence overall or only in those with hormone receptor–positive disease, respectively. CONCLUSION This survey showed suboptimal knowledge, practice, and attitudes of physicians from LMICs on fertility preservation and pregnancy after treatment completion in young women with breast cancer. Increasing awareness and education on these aspects are needed to improve adherence to available guidelines and to promote patients' oncofertility counseling.Supported in part by the Italian Ministry of Health—5x1000 funds 2017 (no grant number) and the Italian Association for Cancer Research (AIRC; MFAG 2020 ID 24698)

    Knowledge, Practice, and Attitudes of Physicians in Low- and Middle-Income Countries on Fertility and Pregnancy-Related Issues in Young Women With Breast Cancer

    Get PDF
    PURPOSE: Fertility and pregnancy-related issues are highly relevant for young ( 64 40 years) patients with breast cancer. Limited evidence exists on knowledge, practice, and attitudes of physicians from low- and middle-income countries (LMICs) regarding these issues. METHODS: A 19-item questionnaire adapted from an international survey exploring issues about fertility preservation and pregnancy after breast cancer was sent by e-mail between November 2019 and January 2020 to physicians from LMICs involved in breast cancer care. Descriptive analyses were performed. RESULTS: A total of 288 physicians from Asia, Africa, America, and Europe completed the survey. Median age was 38 years. Responders were mainly medical oncologists (44.4%) working in an academic setting (46.9%). Among responders, 40.2% and 53.8% reported having never consulted the available international guidelines on fertility preservation and pregnancy after breast cancer, respectively. 25.0%, 19.1%, and 24.3% of responders answered to be not at all knowledgeable about embryo, oocyte, or ovarian tissue cryopreservation, respectively; 29.2%, 23.6%, and 31.3% declared that embryo, oocyte, and ovarian tissue cryopreservation were not available in their countries, respectively. 57.6% of responders disagreed or were neutral on the statement that controlled ovarian stimulation can be considered safe in patients with breast cancer. 49.7% and 58.6% of responders agreed or were neutral on the statement that pregnancy in breast cancer survivors may increase the risk of recurrence overall or only in those with hormone receptor-positive disease, respectively. CONCLUSION: This survey showed suboptimal knowledge, practice, and attitudes of physicians from LMICs on fertility preservation and pregnancy after treatment completion in young women with breast cancer. Increasing awareness and education on these aspects are needed to improve adherence to available guidelines and to promote patients' oncofertility counseling
    corecore