Stochastic expansions using continuous dictionaries: L\'{e}vy adaptive regression kernels

This article describes a new class of prior distributions for nonparametric function estimation. The unknown function is modeled as a limit of weighted sums of kernels or generator functions indexed by continuous parameters that control local and global features such as their translation, dilation, modulation and shape. L\'{e}vy random fields and their stochastic integrals are employed to induce prior distributions for the unknown functions or, equivalently, for the number of kernels and for the parameters governing their features. Scaling, shape, and other features of the generating functions are location-specific to allow quite different function properties in different parts of the space, as with wavelet bases and other methods employing overcomplete dictionaries. We provide conditions under which the stochastic expansions converge in specified Besov or Sobolev norms. Under a Gaussian error model, this may be viewed as a sparse regression problem, with regularization induced via the L\'{e}vy random field prior distribution. Posterior inference for the unknown functions is based on a reversible jump Markov chain Monte Carlo algorithm. We compare the L\'{e}vy Adaptive Regression Kernel (LARK) method to wavelet-based methods using some of the standard test functions, and illustrate its flexibility and adaptability in nonstationary applications.Comment: Published in at http://dx.doi.org/10.1214/11-AOS889 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Study of Ni Metallization in Macroporous Si Using Wet Chemistry for Radio Frequency Cross-Talk Isolation in Mixed Signal Integrated Circuits.

A highly conductive moat or Faraday cage of through-the-wafer thickness in Si substrate was proposed to be effective in shielding electromagnetic interference thereby reducing radio frequency (RF) cross-talk in high performance mixed signal integrated circuits. Such a structure was realized by metallization of selected ultra-high-aspect-ratio macroporous regions that were electrochemically etched in p- Si substrates. The metallization process was conducted by means of wet chemistry in an alkaline aqueous solution containing Ni2+ without reducing agent. It is found that at elevated temperature during immersion, Ni2+ was rapidly reduced and deposited into macroporous Si and a conformal metallization of the macropore sidewalls was obtained in a way that the entire porous Si framework was converted to Ni. A conductive moat was as a result incorporated into p- Si substrate. The experimentally measured reduction of crosstalk in this structure is 5~18 dB at frequencies up to 35 GHz

Essential Role of NK Cells in IgG Therapy for Experimental Autoimmune Encephalomyelitis

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Effect of thiabendazole and hydrogen peroxide on the pathogen of dry rot of potato

Potato is an important food crop produced all around the world but its susceptibility to a number of post-harvest and storage diseases, including dry rot caused by Fusarium species, has caused a noticeable yield loss. This study was conducted to examine the effect of two chemicals, thiabendazole and hydrogen peroxide on a Fusarium sp., isolated from diseased potato tubers and proved to be pathogenic. The effectiveness of the chemicals was first evaluated in vitro on potato dextrose agar plates amended with the chemicals, and then in vivo on artificially inoculated potato tubers by dipping method. Colony diameters of the pathogen on chemicals amended plates were measured and compared with those on chemicals-free PDA plates (Control) while disease incidence and disease severity were assessed for the chemicals-treated tubers in comparison with non-treated ones. The results showed successful inhibition of the pathogen growth by both chemicals in vitro at concentrations of 7.5 mg L-1 of thiabendazole in potato dextrose agar and 1:111 v/v or 9 ml of hydrogen peroxide in 1 L of medium. However, the two chemicals did not prove to successfully suppress the growth of the pathogenic Fusarium and the development of dry rot on the potato over 21 days of incubation. Further studies on method to apply the chemicals are warranted to prove the efficacy of the two chemicals in controlling the pathogen growth and development on potato tubers

Development of an ESL curriculum to educate Chinese immigrants about hepatitis B.

Chinese immigrants to North America have substantially higher rates of chronic hepatitis B infection than the general population. One area for strategic development in the field of health education is the design and evaluation of English-as-a-Second language (ESL) curricula. The theoretical perspective of the Health Behavior Framework, results from a community-based survey of Chinese Canadian immigrants with limited English proficiency, and findings from focus groups of ESL instructors as well as Chinese ESL students were used to develop a hepatitis B ESL educational module. This research was conducted in Vancouver, BC. Survey data showed that less than three-fifths of the respondents had been tested for hepatitis B, and documented some important hepatitis B knowledge deficits. Further, only about one-quarter had ever received a physician recommendation for hepatitis B serologic testing. The ESL curriculum aims to both promote hepatitis B testing and improve knowledge, and includes seven different ESL exercises: Warm-up, vocabulary cards, information-gap, video, jigsaw, guided discussion, and problem/advice cards. Our quantitative and qualitative methods for curriculum development could be replicated for other health education topics and in other limited English speaking populations

Effect of Cardiac and Noncardiac Conditions on Survival After Defibrillator Implantation

ObjectivesWe sought to examine outcomes in recipients of implantable cardioverter-defibrillators (ICDs) and the effect of age, gender, and comorbidities on survival.BackgroundAge, gender, and comorbidities may significantly affect outcomes in ICD recipients.MethodsWe examined factors associated with mortality in 2,467 ICD recipients in Ontario, Canada, using a province-wide database. Comorbidities were identified retrospectively by examining all diagnosis codes within the 3 years before implant.ResultsMean ages at ICD implant were 63.2 ± 12.5 years (1,944 men) and 59.8 ± 15.9 years (523 women). Mortality rates at one and 2 years were 7.8% and 14.0%. Older age at implant increased the risk of death with hazard ratios (HR) of 2.05 (95% confidence interval [CI] 1.70 to 2.47) and 3.00 (95% CI 2.43 to 3.71) for those 65 to 74 years and ≥75 years, respectively (both p < 0.001), but gender was not a predictor of death. Common noncardiac conditions associated with death included peripheral vascular disease (adjusted HR 1.50, 95% CI 1.18 to 1.91), pulmonary disease (adjusted HR 1.35, 95% CI 1.10 to 1.66), and renal disease (adjusted HR 1.57, 95% CI 1.25 to 1.99). Many ICD recipients had prior heart failure (46.2%) with an increased HR of 2.33 for death (95% CI 1.96 to 2.76; p < 0.001). Greater comorbidity burden conferred increased risk, with HRs adjusted for age, gender, and heart failure of 1.72 (95% CI 1.44 to 2.05), 2.79 (95% CI 2.15 to 3.62), and 2.98 (95% CI 1.74 to 5.10) for those with 1, 2, and 3 or more noncardiac comorbidities, respectively (all p < 0.001).ConclusionsAge, noncardiac comorbidities, and prior heart failure influence survival outcomes in ICD recipients. These factors should be considered in the care of ICD recipients

Hepatitis B testing and vaccination in immigrants attending english as a second language classes in british columbia, Canada.

Background: Hepatitis B virus (HBV) is a growing health issue in Canada, especially given that population growth is now largely the result of immigration. Immigrants from countries with high HBV prevalence and low levels of HBV vaccination have an excess risk of liver disease and there is a need for increased diligence in HBV blood testing and possibly vaccination among these populations. Objective: This study describes the sociodemographic characteristics associated with a history of HBV testing and HBV vaccination in immigrants from several countries with high HBV prevalence who are attending English classes. Methods: 759 adult immigrants attending English as a Second Language classes completed a self-administered questionnaire asking about sociodemographic characteristics and history of HBV testing and HBV vaccination. Descriptive statistics and adjusted ORs were calculated to explore these associations. Results: 71% reported prior HBV testing, 8% reported vaccination without testing, and 21% reported neither testing nor vaccination. Age, education and country of birth all showed significant effects for both testing and vaccination. Conclusions: Health care practitioners need to be cognizant of HBV testing, and possibly vaccination, in some of their patients, including immigrants from countries with endemic HBV infection. Infected persons need to be identified by blood testing in order receive necessary care to prevent or delay the onset of liver disease as well as to adopt appropriate behaviours to reduce the risk of transmission to others. Close contacts of infected persons also require HBV testing and subsequent vaccination (if not infected) or medical management (if infected)

Natural killer cells become tolerogenic after interaction with apoptotic cells

NK cells are effectors in innate immunity and also participate in immunoregulation through the release of TGF-β1 and lysis of activated/autoreactive T cells. Apoptotic cells (AC) have been shown to induce tolerogenic properties in innate immune cells, including macrophages and dendritic cells, but not NK cells. In this study, we demonstrated that after interaction with AC, NK cells released TGF-β1, which in turn suppressed the production of IFN-γ by NK cells upon IL-12 and IgG activation.We further identified phosphatidylserine as a potential target on AC for the NK cells, as phosphatidylserine could stimulate NK cells to release TGF-β1, which in turn suppressed CD4+ T-cell proliferation and activation. Moreover, AC-treated NK cells displayed cytotoxicity against autologous-activated CD4 + T cells by upregulating NKp46. This lysis occurred in part through the NKp46-vimentin pathway, as activated CD4+ T cells expressed vimentin on the cell surface and blocking of vimentin or NKp46, but not other NK-cell receptors, significantly suppressed the NK-cell cytotoxicity.We report here a novel interaction between NK cells and AC, resulting in the tolerogenic properties of NK cells required for immune contraction. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.postprin

Evaluation of a hepatitis B lay health worker intervention for Chinese Americans and Canadians.

Hepatitis B testing is recommended for immigrants from countries where hepatitis B infection is endemic. However, only about one-half of Chinese in North America have received hepatitis B testing. We conducted a randomized controlled trial to evaluate the effectiveness of a hepatitis B lay health worker intervention for Chinese Americans/Canadians. Four hundred and sixty individuals who had never been tested for hepatitis B were identified from community-based surveys of Chinese conducted in Seattle, Washington, and Vancouver, British Columbia. These individuals were randomly assigned to receive a hepatitis B lay health worker intervention or a direct mailing of physical activity educational materials. Follow-up surveys were completed 6 months after randomization. Self-reported hepatitis B testing was verified through medical records review. A total of 319 individuals responded to the follow-up survey (69% response rate). Medical records data verified hepatitis B testing since randomization for 9 (6%) of the 142 experimental group participants and 3 (2%) of the 177 control group participants (P = 0.04). At follow-up, a higher proportion of individuals in the experimental arm than individuals in the control arm knew that hepatitis B can be spread by razors (P < 0.001) and during sexual intercourse (P = 0.07). Our findings suggest that lay health worker interventions can impact hepatitis B-related knowledge. However, our hepatitis B lay health worker intervention had a very limited impact on hepatitis B testing completion. Future research should evaluate other intervention approaches to improving hepatitis B testing rates among Chinese in North America

Application and comparison of scoring indices to predict outcomes in patients with healthcare-associated pneumonia

Introduction: Healthcare-associated pneumonia HCAP is a relatively new category of pneumonia. It refers to infections that occur prior to hospital admission in patients with specific risk factors following contact or exposure to a healthcare environment. There is currently no scoring index to predict the outcomes of HCAP patients. We applied and compared different community acquired pneumonia CAP scoring indices to predict 30-day mortality and 3-day and 14-day intensive care unit ICU admission in patients with HCAP. Methods: We conducted a retrospective cohort study based on an inpatient database from six medical centers, recruiting a total of 444 patients with HCAP between 1 January 2007 and 31 December 2007. Pneumonia severity scoring indices including PSI pneumonia severity index, CURB 65 confusion, urea, respiratory rate, blood pressure , age 65, IDSA/ATS Infectious Diseases Society of America/American Thoracic Society, modified ATS rule, SCAP severe community acquired pneumonia, SMART-COP systolic blood pressure, multilobar involvement, albumin, respiratory rate, tachycardia, confusion, oxygenation, pH, SMRT- CO systolic blood pressure, multilobar involvement, respiratory rate, tachycardia, confusion, oxygenation, and SOAR systolic blood pressure, oxygenation, age, respiratory rate were calculated for each patient. Patient characteristics, co-morbidities, pneumonia pathogen culture results, length of hospital stay LOS, and length of ICU stay were also recorded. Results: PSI > 90 has the highest sensitivity in predicting mortality, followed by CURB-65 >= 2 and SCAP > 9 SCAP score area under the curve AUC: 0.71, PSI AUC: 0.70 and CURB-65 AUC: 0.66. Compared to PSI, modified ATS, IDSA/ATS, SCAP, and SMART-COP were easy to calculate. For predicting ICU admission Day 3 and Day 14, modified ATS AUC: 0.84, 0.82 , SMART-COP AUC: 0.84, 0.82, SCAP AUC: 0.82, 0.80 and IDSA/ ATS AUC: 0.80, 0 .79 performed better statistically significant difference than PSI, CURB- 65, SOAR and SMRT-CO. Conclusions: The utility of the scoring indices for risk assessment in patients with healthcare-associated pneumonia shows that the scoring indices originally designed for CAP can be applied to HCAP