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Sample records for 4-h patch test

  1. Patch tests*

    PubMed Central

    Lazzarini, Rosana; Duarte, Ida; Ferreira, Alessandra Lindmayer

    2013-01-01

    Patch tests were introduced as a diagnostic tool in the late nineteenth century. Since then, they have improved considerably becoming what they are today. Patch tests are used in the diagnostic investigation of contact dermatitis worldwide. Batteries or series previously studied and standardized should be used in patch testing. The methodology is simple, but it requires adequate training for the results to be correctly interpreted and used. Despite having been used for over a century, it needs improvement like all other diagnostic techniques in the medical field. PMID:24474094

  2. [Patch testing: historical aspects].

    PubMed

    Lachapelle, J-M

    2009-01-01

    This article reviews the key points in the history of patch testing, which spans more than a century, starting with the first description of the method by J. Jadassohn in 1895. Special attention is paid to the contribution of French schools in this field, which led to the foundation of the Groupe d'études et de recherches en dermato-allergologie (GERDA). PMID:19686889

  3. Stability of patch test allergens.

    PubMed

    Joy, Nicole Marie; Rice, Kristen R; Atwater, Amber Reck

    2013-01-01

    Patch testing is widely used in evaluating suspected contact dermatitis. One major component of a quality patch test result is a dependable, predictable allergen supply. The allergen needs to be present at a sufficient concentration to elicit a reaction in an allergic patient. To better understand the stability of patch-test allergens, we completed a systematic review of the literature. We found that there is variability in stability among patch-test allergens and that although a few have been shown to be stable, many degrade when in storage. In most cases, expiration dates should be honored. In addition, allergen panels should be prepared as close to the time of patch test application as is possible. PMID:24030367

  4. Easier patch testing with TRUE Test.

    PubMed

    Fischer, T; Maibach, H I

    1989-03-01

    TRUE Test, a standardized, ready-to-apply patch test system, is made from polyester covered with a film of allergens incorporated in a hydrophilic polymer. The patches are mounted on nonwoven cellulose tape with acrylic adhesive, covered with siliconized plastic, and packed in an air-tight and light-impermeable envelope. When the test strip is taped on the skin, perspiration hydrates the film and transforms it to a gel, which causes the allergen to be released. The first panel of 12 allergens and allergen mixes is standardized and tested for stability in vitro and in vivo. The accuracy of the test panel has been certified in international multicenter studies by comparing it with present patch test techniques. A second panel of 11 more allergens was completed in 1988. The two test panels include the full standard panel of the North American Contact Dermatitis Group. PMID:2918115

  5. Routine patch testing with paraben esters.

    PubMed

    Menné, T; Hjorth, N

    1988-09-01

    Paraben esters are the most widely used preservatives in cosmetics and topical medicaments. Their sensitization potential is low, based on both experimental and human experience. A paraben mixture is included in the ICDRG standard series, and in patch test studies, approximately 1% of eczema patients react to it. The present study confirms this frequency in 8020 patients patch tested consecutively. Testing with the individual paraben esters was employed as confirmation, which makes it unlikely that the excited skin syndrome is a significant problem in this context. It remains undetermined whether the present paraben mixture is the optimal patch test material for diagnosing paraben sensitivity. PMID:3191679

  6. Patch testing with cement containing iron sulfate.

    PubMed

    Bruze, M; Fregert, S; Gruvberger, B

    1990-01-01

    Addition of iron sulfate to cement means transformation of water-soluble hexavalent chromium into nonwater-soluble trivalent chromium. This has been the basis for preventive measures concerning sensitization to hexavalent chromium (chromate) in cement. For some years, iron sulfate has been added to cement manufactured in the Scandinavian countries. In the present in vivo study, cements with and without iron sulfate were compared concerning their capacity to elicit allergic patch-test reactions in eight chromate-hypersensitive individuals. No patch-test reactions were obtained from a water extract of cement with iron sulfate when appropriately buffered. PMID:2137395

  7. Contact Dermatitis, Patch Testing, and Allergen Avoidance.

    PubMed

    Burkemper, Nicole M

    2015-01-01

    In patients presenting with a complaint of rash, contact dermatitis is often the underlying diagnosis making it an entity with which health care providers should be familiar. Contact dermatitis can be divided into irritant contact dermatitis and allergic contact dermatitis. In a patient suspected of having allergic contact dermatitis, patch testing can be done to identify specific allergens. Education focused on allergen avoidance and safe products is an integral part of treatment for the contact dermatitis patient. Knowledge of the most common allergens is helpful for clinicians to be able to provide this education. PMID:26455061

  8. Value of Gluten Patch Test in Diagnosis of Celiac Disease

    PubMed Central

    Saneian, Hosein; Zandieh, Fariborz; Akhavan, Paria; Taherian, Rouzbeh

    2011-01-01

    Objective Celiac disease is an intestinal disorder identified by mucus inflammation, villous atrophy and crypt hyperplasia. This disorder can be controlled by elimination of gluten from daily diet. Patients with celiac disease are at greater risk of gastrointestinal malignancy and non-Hodgkin lymphoma than are the general population. This study tries to present the value of gluten patch test for diagnosis of celiac disease. Methods In this investigation, the study population was divided into case and control groups. The case group consisted of patients with celiac disease. The control group were patients involved in celiac disease but suffering from other gastrointestinal disorders. Both gluten patch and placebo patch were attached to the skin between the scapulas. The results were read twice: 48 hours and 96 hours after the patch was applied. Patients who showed irritation reactions were withdrawn from this study. The results were analysed by SPSS software, Spearman's test, chi square, and Mann–Whitney tests. Findings The value obtained from the gluten patch test after 96 hours are as follows: specification at 95%, sensitivity at 8%, positive prediction value at 67%, and negative prediction value at 43%. Conclusion It can be concluded that the gluten patch test is not an efficient test for screening of celiac disease, however, it can be useful for diagnosis of celiac disease if employed and studied with clinical symptoms and serologic and biopsy tests. Furthermore, we should doubt our judgment if the result of gluten patch test for the patient with celiac disease is positive. PMID:23056837

  9. 4H-SiC JFET Multilayer Integrated Circuit Technologies Tested Up to 1000 K

    NASA Technical Reports Server (NTRS)

    Spry, D. J.; Neudeck, P. G.; Chen, L.; Chang, C. W.; Lukco, D.; Beheim, G. M.

    2015-01-01

    Testing of semiconductor electronics at temperatures above their designed operating envelope is recognized as vital to qualification and lifetime prediction of circuits. This work describes the high temperature electrical testing of prototype 4H silicon carbide (SiC) junction field effect transistor (JFET) integrated circuits (ICs) technology implemented with multilayer interconnects; these ICs are intended for prolonged operation at temperatures up to 773K (500 C). A 50 mm diameter sapphire wafer was used in place of the standard NASA packaging for this experiment. Testing was carried out between 300K (27 C) and 1150K (877 C) with successful electrical operation of all devices observed up to 1000K (727 C).

  10. Dermatotoxicologic clinical solutions: textile dye dermatitis patch testing.

    PubMed

    Coman, Garrett; Blickenstaff, Nicholas; Edwards, Ashley; Maibach, Howard

    2015-03-01

    The authors provide a framework for working up and counseling a patient with suspected textile dermatitis, focusing on identifying which textile materials are most likely to be the cause of the eczematous lesions, the current clinical guidelines, the utility and appropriateness of patch testing, the limitations of these guidelines, and our pro tempore recommendations. While there are many challenges to correctly identify and counsel patients on how to avoid the offending textile products in a patient with suspected textile dye dermatitis, there is value in following the guidelines set forth to help identify the causative textile(s). Although patch tests can be useful, dermatologists should understand the limitations of standardized patch testing for patients with suspected textile dye-induced dermatitis. These guidelines are expected to increase the likelihood of identifying the causative textile(s), so that patch testing can be supplemented with swatch testing and chemical dye extraction to help discover the allergenic dye. PMID:24678750

  11. Membrane Vibration Tests Using Surface-Bonded Piezoelectric Patch Actuation

    NASA Technical Reports Server (NTRS)

    Gasper, James L.; Pappa, Richard S.

    2003-01-01

    This paper describes the status of on-going work at the NASA Langley Research Center to measure the dynamics of thin membranes. The test article is a one-meter square pre-tensioned Kapton membrane that incorporates small surface-bonded piezoelectric patches strategically positioned to excite many modes. It is shown that PVDF (polyvinylidene fluoride) and MFC (macro fiber composite) piezoelectric patch actuators provide adequate excitation energy to obtain modal frequencies and mode shapes. Results from modal tests performed on the membrane using piezoelectric patches of different sizes and positions are discussed.

  12. Rapid diagnosis of cholera by coagglutination test using 4-h fecal enrichment cultures.

    PubMed Central

    Rahman, M; Sack, D A; Mahmood, S; Hossain, A

    1987-01-01

    A simple, rapid, and reliable method to detect Vibrio cholerae in fecal specimens would assist in the management of cases of severe diarrhea, especially since most such cases occur in areas with minimal laboratory facilities. A coagglutination test was used to detect V. cholerae antigen in bile-peptone broth incubated with feces. In the technique, Staphylococcus aureus Cowan 1 coated with anti-V. cholerae O1 antiserum was tested with cultures incubated for 4 h. When 165 specimens were tested, the sensitivity, specificity, and accuracy of the test, compared with standard culture methods, were 97, 99, and 98%, respectively. These promising results were better than those of dark-field microscopy using the same specimens, and the test was logistically easy to perform. The coagglutination test using enrichment broth culture of feces is a simple and rapid method which may be used to confirm a diagnosis of cholera. PMID:3693549

  13. Aeroallergen Patch Testing in Patients of Suspected Contact Dermatitis

    PubMed Central

    Bisen, Nelee; Shenoi, Shrutakirthi D; Balachandran, C

    2014-01-01

    Background: Aeroallergens are airborne substances present in the environment with the potential to trigger an allergic reaction in the respiratory tract, mucosae, or skin of susceptible individuals. The relevance of aeroallergens in the pathogenesis of atopic dermatitis has been reported by many investigators. However, very few studies have been conducted to investigate their role in the production of allergic contact dermatitis (ACD). Aims: To determine the prevalence of aeroallergen patch test positivity in patients of suspected ACD and to study the clinical characteristics of patients testing positive with aeroallergens. Materials and Methods: Patients presenting to our department with suspected contact allergy and undergoing patch testing with Indian Standard Series (ISS) between January 2010 and June 2011 were studied. After a detailed history and clinical examination, patients were patch tested with ISS and aeroallergen series. Based on the history and clinical suspicion, patients were additionally patch tested with 15% Parthenium. Prior tape stripping was done in some patients. Results: Out of total 114 patients, 26 (22.8%) showed sensitivity to aeroallergen series. Parthenium was the commonest aeroallergen being positive in all 26 patients followed by Xanthium in two. None reacted to other allergens. Although positivity was more in patients with prior tape stripping, the difference was not statistically significant. Conclusion: Most common aeroallergen found to be positive in our study was Parthenium hysterophorus. In view of low positivity to other allergens, routine aeroallergen patch testing in patients with suspected contact dermatitis may not be necessary. PMID:24891655

  14. Photopatch and UV-irradiated patch testing in photosensitive dermatitis

    PubMed Central

    Rai, Reena; Thomas, Maria

    2016-01-01

    Background: The photopatch test is used to detect photoallergic reactions to various antigens such as sunscreens and drugs. Photosensitive dermatitis can be caused due to antigens like parthenium, fragrances, rubbers and metals. The photopatch test does not contain these antigens. Therefore, the Indian Standard Series (ISS) along with the Standard photopatch series from Chemotechnique Diagnostics, Sweden was used to detect light induced antigens. Aim: To detect light induced antigens in patients with photosensitive dermatitis. Methods: This study was done in a descriptive, observer blinded manner. Photopatch test and ISS were applied in duplicate on the patient's back by the standard method. After 24 hours, readings were recorded according to ICDRG criteria. One side was closed and other side irradiated with 14 J/cm2 of UVA and a second set of readings were recorded after 48 hrs. Result: The highest positivity was obtained with parthenium, with 18 out of 35 (51%) patients showing a positive patch test reaction with both photoallergic contact dermatitis and photoaggravation. Four patients (11%) showed positive patch test reaction suggestive of contact dermatitis to potassium dichromate and fragrance mix. Six patients had contact dermatitis to numerous antigens such as nickel, cobalt, chinoform and para-phenylenediamine. None of these patients showed photoaggravation on patch testing. Conclusion: Parthenium was found to cause photoallergy, contact dermatitis with photoaggravation and contact allergy. Hence, photopatch test and UV irradiated patch test can be an important tool to detect light induced antigens in patients with photosensitive dermatitis. PMID:26955581

  15. Benzyl salicylate: a survey of consumer patch-test sensitization.

    PubMed

    Kohrman, K A; Booman, K A; Dorsky, J; Rothenstein, A S; Sedlak, R I; Steltenkamp, R J; Thompson, G R

    1983-12-01

    The potential of benzyl salicylate, an important fragrance and flavour ingredient, to induce hypersensitivity or to elicit reactions to pre-existing hypersensitivity in the general population was evaluated by analysing patch-test data. Results obtained from fragrance and formulator companies for a total of 10,538 patch tests on benzyl salicylate alone, on a variety of household and personal care consumer products and on fragrance blends containing benzyl salicylate were analysed as part of this survey. No induced or elicited responses directly attributable to benzyl salicylate were observed in the 35 patch tests on benzyl salicylate alone, or in the 10,503 patch tests on consumer products or fragrance blends containing benzyl salicylate. The highest concentration of benzyl salicylate tested in the consumer-product tests was 2 X 10(-1)%, and benzyl salicylate alone was tested at 10% in ethanol. This study indicates that benzyl salicylate has a very low potential to induce hypersensitivity ('induced' reactions) or to elicit reactions presumably attributable to pre-existing sensitization ('elicited' reactions) and thus supports the safe use of benzyl salicylate in consumer products and fragrance blends. PMID:6686578

  16. Patch Testing with Dental Screening Series in Oral Disease

    PubMed Central

    Kim, Tae-Wook; Kim, Woo-Il; Mun, Je-Ho; Song, Margaret; Kim, Hoon-Soo; Kim, Byung-Soo; Kim, Moon-Bum

    2015-01-01

    Background The oral mucosa is constantly exposed to several irritants and allergens including dental materials, but the role of contact allergy in oral disease is obscure. Objective To analyze positive patch test results in patients with oral diseases and evaluate the clinical relevance of oral diseases with contact allergy to dental materials. Methods We retrospectively analyzed patch test results with dental screening series in 44 patients with oral disease from 2004~2011. Results Oral diseases included oral lichen planus (54.5%), cheilitis (27.3%), burning mouth syndrome (9.1%), and others (9.1%). Thirty-one of 44 patients (70.5%) had positive reactions to one or more allergens. The most commonly detected allergens were gold sodium thiosulfate (25.0%) and nickel sulfate (25.0%), followed by potassium dichromate (22.7%), cobalt (15.9%), palladium (6.8%), mercury (4.5%), copper (4.5%), and methylhydroquinone (4.5%). Six of 24 patients with oral lichen planus had a symptom in areas adjacent to dental materials and positive patch test reactions to allergens contained in the suspected dental materials. Conclusion Patch tests with dental screening series are worth considering for oral diseases, especially for oral lichen planus. PMID:26273153

  17. Patch Testing in Suspected Allergic Contact Dermatitis to Cosmetics

    PubMed Central

    Paulose, Rekha

    2014-01-01

    Background. Increasing use of cosmetics has contributed to a rise in the incidence of allergic contact dermatitis (ACD) to cosmetics. It is estimated that 1–5.4% of the population is sensitized to a cosmetic ingredient. Patch testing helps to confirm the presence of an allergy and to identify the actual allergens which are chemical mixtures of various ingredients. Objectives. The aims of this study are to perform patch testing in suspected ACD to cosmetics and to identify the most common allergen and cosmetic product causing dermatitis. Methods. Fifty patients with suspected ACD to cosmetics were patch-tested with 38 antigens of the Indian Cosmetic Series and 12 antigens of the Indian Standard Series. Results. The majority (58%) of patients belonged to the 21–40 years age group. The presence of ACD to cosmetics was confirmed in 38 (76%) patients. Face creams (20%), hair dyes (14%), and soaps (12%) were the most commonly implicated. The most common allergens identified were gallate mix (40%), cetrimide (28%), and thiomersal (20%). Out of a total of 2531 patches applied, positive reactions were obtained in 3.75%. Conclusion. Incidence of ACD to cosmetics was greater in females. Face creams and hair dyes were the most common cosmetic products implicated. The principal allergens were gallate mix, cetrimide, and thiomersal. PMID:25295057

  18. Patch testing with components of water-based metalworking fluids.

    PubMed

    Geier, Johannes; Lessmann, Holger; Frosch, Peter J; Pirker, Claudia; Koch, Patrick; Aschoff, Roland; Richter, Gerhard; Becker, Detlef; Eckert, Christian; Uter, Wolfgang; Schnuch, Axel; Fuchs, Thomas

    2003-08-01

    Water-based metalworking fluids (MWFs) may cause both irritant and allergic contact dermatitis. Several well-known MWF allergens are available for patch testing, but considering the wide variety of possible components used in MWF, our diagnostic arsenal covers only a small part of potential allergens. We therefore selected 13 frequently used MWF components that might be sensitizers and had not yet been tested routinely. In 5 centres, 233 dermatitis patients with present or past occupational exposure to MWF were patch tested with this and other panels. Only 7 patients showed positive reactions to the study panel. Allergic reactions to the emulsifier diglycolamine [syn. 2-(2-aminoethoxy) ethanol] were seen in 5 patients, and 1 patient each reacted positively to 2-amino-2-ethyl-1,3-propanediol (AEPD) and methyldiethanolamine (MDEA). Clinical relevance of the reactions to diglycolamine was unequivocally proven by its presence in the MWF from the patients' workplace in 3 cases. Diglycolamine seems to be an important MWF allergen, independently from monoethanolamine and diethanolamine. A test concentration of 1% petrolatum (pet.) appears to be appropriate. The importance of AEPD and MDEA as MWF allergens still remains to be established. The lack of positive test reactions to the other MWF components tested may be due to their low-sensitizing potential or too low a patch test concentration being used. PMID:14641356

  19. Impulse Testing of Corporate-Fed Patch Array Antennas

    NASA Technical Reports Server (NTRS)

    Chamberlain, Neil F.

    2011-01-01

    This paper discusses a novel method for detecting faults in antenna arrays. The method, termed Impulse Testing, was developed for corporate-fed patch arrays where the element is fed by a probe and is shorted at its center. Impulse Testing was devised to supplement conventional microwave measurements in order to quickly verify antenna integrity. The technique relies on exciting each antenna element in turn with a fast pulse (or impulse) that propagates through the feed network to the output port of the antenna. The resulting impulse response is characteristic of the path through the feed network. Using an oscilloscope, a simple amplitude measurement can be made to detect faults. A circuit model of the antenna elements and feed network was constructed to assess various fault scenarios and determine fault-detection thresholds. The experimental setup and impulse measurements for two patch array antennas are presented. Advantages and limitations of the technique are discussed along with applications to other antenna array topologies

  20. Adhesion testing of polyurethane matrix patches for transdermal delivery of testosterone.

    PubMed

    Dittgen, M; Gansen, P

    2012-06-01

    The 180 degrees peel test was applied to measure adhesion of three experimental polyurethane (PU) matrix patches and one commercial patch, Testopatch, on human volunteers skin. Comparing the results with those measurements on stainless steel or leather, a significant correlation between the leather data and the skin measurements was found. In contrary to results from stainless steel tests, all of the PU patches achieved better adhesion on skin than the commercial patch. PMID:22822549

  1. Reproducibility of patch tests: comparison of identical test allergens from different commercial sources.

    PubMed

    Schiessl, Claudia; Wolber, Carola; Strohal, Robert

    2004-01-01

    The reproducibility of patch tests is an important determinant of the clinical value of this diagnostic procedure. The aim of the present study was to delineate comparatively the efficiency and reproducibility of identical test reagents from 2 different commercial sources. Purchased in duplicate from brial and Boots-Hermal, 30 allergens from the European standard and an extension series were simultaneously applied to Finn Chambers and affixed next to each other. Out of 2070 paired patch tests in 71 patients, 97.2% presented with concordant-negative results. 60 patch tests were classified as allergic with 95% concordant-positive results. From these paired positive patches, a subgroup of 13 (22.8%) corresponding allergens presented with minor differences in the visible strength of the allergic reaction. Generated by cobalt chloride, formaldehyde and 2-bromo-2-nitropropane-1,3-diol in 1 patient each, discordant results, i.e. 1 positive and 1 negative test in parallel, were found in only 5%. Taken together, we were able to demonstrate that patch test preparations from 2 different companies exhibited a high level of reproducibility. This standardized quality of test reagents from different suppliers provides useful information on several aspects of everyday practice. PMID:15059100

  2. Single doses of local betamethasone do not suppress allergic patch test reactions to nickel sulfate.

    PubMed

    Molander, Gerd; Petman, Leena; Kannas, Liisa; Lauerma, Antti I

    2004-04-01

    Topical corticosteroids are usually banned on test areas prior to patch testing. The previous literature on the effect of topical corticosteroids is conflicting. Patients allergic to nickel sulfate were patch tested on 4 sites with nickel on day (D) 0. Intracutaneous betamethasone was injected to test sites on D-1, D0 and D1. NaCl injection on D-1 was control. The patch test reactions were evaluated clinically and with laser Doppler. There were no differences in patch test reaction intensities on sites treated with intracutaneous betamethasone as compared to control. A single local dose of potent corticosteroid does not suppress allergic patch reactions to nickel. The current practice of avoiding topical corticosteroid use prior to patch testing should be re-evaluated. PMID:15186376

  3. A Pragmatic Approach to Patch Testing Atopic Dermatitis Patients: Clinical Recommendations Based on Expert Consensus Opinion.

    PubMed

    Chen, Jennifer K; Jacob, Sharon E; Nedorost, Susan T; Hanifin, Jon M; Simpson, Eric L; Boguniewicz, Mark; Watsky, Kalman L; Lugo-Somolinos, Aida; Hamann, Carsten R; Eberting, Cheryl Lee; Silverberg, Jonathan I; Thyssen, Jacob P

    2016-01-01

    Allergic contact dermatitis (ACD) may complicate the clinical course of atopic dermatitis (AD), and patch testing remains the criterion standard for diagnosing ACD. To date, there have been no guidelines or consensus recommendations on when and how to patch test individuals with AD. Failure to patch test when appropriate may result in overlooking an important and potentially curable complicating comorbidity. In this article, we present consensus recommendations regarding when to perform patch testing in the AD patient, best practices, and common pitfalls. Patch testing should be considered in AD patients with dermatitis that fails to improve with topical therapy; with atypical/changing distribution of dermatitis, or pattern suggestive of ACD; with therapy-resistant hand eczema in the working population; with adult- or adolescent-onset AD; and/or before initiating systemic immunosuppressants for the treatment of dermatitis. A suggested patch testing algorithm for AD patients is provided. PMID:27427820

  4. Patch testing a patient with allergic contact hand dermatitis who is taking infliximab.

    PubMed

    Rosmarin, David; Bush, Michelle; Scheinman, Pamela L

    2008-07-01

    We report the case of a patient who developed allergic contact hand dermatitis while receiving infliximab infusions for psoriasis and psoriatic arthritis. Patch testing showed multiple positive allergens. To our knowledge, this is the first case report of successful patch testing in a patient receiving tumor necrosis factor-alpha (TNF-alpha) blockade therapy. TNF-alpha blockers do not necessarily suppress allergic contact hypersensitivity and are not an absolute contraindication to patch testing. PMID:18468722

  5. [Effect of cignolin and infrared irradiation on the patch test and lymphocyte transformation test].

    PubMed

    Eter, J; Schulze, H J; Mahrle, G

    1990-09-01

    In a study on the effect of anthralin and infrared irradiation (IR) on the allergic patch test in vivo and the lymphocyte transformation test in vitro, we observed that anthralin enhanced the local test reaction. Our findings suggest an additive reaction of toxic anthralin dermatitis and allergic test reaction. Immunohistology showed that additional treatment with anthralin resulted in elevated numbers of the OKT-6+ dendritic cells in the epidermis. Anthralin in concentrations of greater than or equal to 10(-5) M inhibited the lymphocyte transformation in vitro. IR irradiation-either before or during patch testing-did not significantly influence the allergic test reaction or the lymphocyte transformation, if the temperature was adjusted to 37 degrees C. In comparison to convective heat, we found no specific effect of IR irradiation. PMID:2264370

  6. Skin reactivity to metallic cobalt in patients with a positive patch test to cobalt chloride.

    PubMed

    de Fine Olivarius, F; Menné, T

    1992-10-01

    458 consecutive patients were patch tested with a metallic cobalt disc as a supplement to the standard series. 23 patients had a positive reaction to CoCl2 1% pet. Of these, 19 were tested with the cobalt disc. 11 had a positive reaction and 5 a questionable reaction. There were no positive reactions to the cobalt disc in patients with a negative patch test to CoCl2 1% pet. Patch testing with CoCl2 1% pet. diagnoses all patients with allergy to metallic cobalt, but the test method is limited by a high number of irritant and questionable reactions. PMID:1451489

  7. The association between size of test chamber and patch test reaction: a statistical reanalysis.

    PubMed

    Gefeller, O; Pfahlberg, A; Geier, J; Brasch, J; Uter, W

    1999-01-01

    A recent study by Brasch and co-workers reported on the association between size of test chamber and patch test reaction. The investigators interpreted their data on 495 patients as having conclusively shown that standard preparations of fragrance mix, wool wax alcohols, Kathon CG and formaldehyde led to more positive test reactions when large Finn Chambers were used for patch testing. We have scrutinized the statistical aspects of this study and conclude that the authors should have adopted a statistical approach suitable to analyse dependent samples. After explaining the correct methodological way of dealing with quadratic contingency tables formed by 2 dependent samples, we reanalyze the data accordingly and compare the results to those of the original paper. Based on this reanalysis, the conclusions are more complex: the reaction pattern for the fragrance mix and wool wax alcohols is significantly different between small and large test chambers; however, this discrepancy arises primarily from changing weak positive reactions with small chambers to strong positive reactions with large chambers. For formaldehyde, no relationship between chamber size and patch test reaction was found in the data, while for Kathon CG, statistical evidence is borderline that more positive test reactions are yielded by large test chambers than by small ones. PMID:9928799

  8. European Society of Contact Dermatitis guideline for diagnostic patch testing - recommendations on best practice.

    PubMed

    Johansen, Jeanne D; Aalto-Korte, Kristiina; Agner, Tove; Andersen, Klaus E; Bircher, Andreas; Bruze, Magnus; Cannavó, Alicia; Giménez-Arnau, Ana; Gonçalo, Margarida; Goossens, An; John, Swen M; Lidén, Carola; Lindberg, Magnus; Mahler, Vera; Matura, Mihály; Rustemeyer, Thomas; Serup, Jørgen; Spiewak, Radoslaw; Thyssen, Jacob P; Vigan, Martine; White, Ian R; Wilkinson, Mark; Uter, Wolfgang

    2015-10-01

    The present guideline summarizes all aspects of patch testing for the diagnosis of contact allergy in patients suspected of suffering, or having been suffering, from allergic contact dermatitis or other delayed-type hypersensitivity skin and mucosal conditions. Sections with brief descriptions and discussions of different pertinent topics are followed by a highlighted short practical recommendation. Topics comprise, after an introduction with important definitions, materials, technique, modifications of epicutaneous testing, individual factors influencing the patch test outcome or necessitating special considerations, children, patients with occupational contact dermatitis and drug eruptions as special groups, patch testing of materials brought in by the patient, adverse effects of patch testing, and the final evaluation and patient counselling based on this judgement. Finally, short reference is made to aspects of (continuing) medical education and to electronic collection of data for epidemiological surveillance. PMID:26179009

  9. [Should metal alloy discs be used for patch testing in suspected metal implant intolerance reaction?].

    PubMed

    Thomas, P; Geier, J; Dickel, H; Diepgen, T; Hillen, U; Kreft, B; Schnuch, A; Szliska, C; Mahler, V

    2015-11-01

    Intolerance reactions to metal implants may be caused by metal allergy. However, prior to implantation, patch testing should not be done in a prophylactic-prophetic approach. Pre-implant patch testing should only be performed to verify or exclude metal allergy in patients with a reported respective history. In the case of implant-in particular arthroplasty-related complications like, for example, pain, effusion, skin changes, reduced range of motion, or loosening, orthopedic-surgical differential diagnostics should be performed first. Allergological workup of suspected metal implant allergy should be done with the DKG baseline series which contains nickel-, cobalt- and chromium-preparations. Various studies assessing the usefulness of metal alloy discs for patch testing proved that this approach does not give reliable information about metal allergy. Positive patch test reactions to the discs cannot be assigned to a specific metal within the disc alloy components. Furthermore, availability of such metal discs might be an invitation to uncritical testing. Accordingly, due to lack of benefit in comparison to patch testing with standardized metal salt preparations, we do not recommend patch testing with metal alloy discs. PMID:26438196

  10. Attitudes about Advances in Sweat Patch Testing in Drug Courts: Insights from a Case Study in Southern California

    ERIC Educational Resources Information Center

    Polzer, Katherine

    2010-01-01

    Drug courts are reinventing the drug testing framework by experimenting with new methods, including use of the sweat patch. The sweat patch is a band-aid like strip used to monitor drug court participants. The validity and reliability of the sweat patch as an effective testing method was examined, as well as the effectiveness, meaning how likely…

  11. False-positive, follicular and irritant patch test reactions to metal salts.

    PubMed

    Fischer, T; Rystedt, I

    1985-02-01

    853 hard metal workers were patch tested with nickel sulphate 5%, potassium dichromate 0.5% and cobalt chloride 1%, each in petrolatum. Non-allergic reactions appeared in 6.5% of the nickel tests, 13% of the chromium tests and 18.3% of the cobalt tests. Most of the individuals with positive, poral or pustular reactions were retested with serial dilutions of metal salts in pet. and in water. The accuracy of a positive initial nickel reaction was 83%, a chromium reaction 40% and a cobalt reaction 62%. The nonallergic reactions were partly reproducible and correlated with both the type of patch test material and with individual factors. Weak and moderately strong positive patch test reactions to metal salts may be irritant and should be checked with serial dilution tests or at least be retested. A reduction of the cobalt chloride concentration from 1% to 0.5% in the standard test material is discussed. PMID:3157537

  12. Inferring local competition intensity from patch size distributions: a test using biological soil crusts

    USGS Publications Warehouse

    Bowker, Matthew A.; Maestre, Fernando T.

    2012-01-01

    Dryland vegetation is inherently patchy. This patchiness goes on to impact ecology, hydrology, and biogeochemistry. Recently, researchers have proposed that dryland vegetation patch sizes follow a power law which is due to local plant facilitation. It is unknown what patch size distribution prevails when competition predominates over facilitation, or if such a pattern could be used to detect competition. We investigated this question in an alternative vegetation type, mosses and lichens of biological soil crusts, which exhibit a smaller scale patch-interpatch configuration. This micro-vegetation is characterized by competition for space. We proposed that multiplicative effects of genetics, environment and competition should result in a log-normal patch size distribution. When testing the prevalence of log-normal versus power law patch size distributions, we found that the log-normal was the better distribution in 53% of cases and a reasonable fit in 83%. In contrast, the power law was better in 39% of cases, and in 8% of instances both distributions fit equally well. We further hypothesized that the log-normal distribution parameters would be predictably influenced by competition strength. There was qualitative agreement between one of the distribution's parameters (μ) and a novel intransitive (lacking a 'best' competitor) competition index, suggesting that as intransitivity increases, patch sizes decrease. The correlation of μ with other competition indicators based on spatial segregation of species (the C-score) depended on aridity. In less arid sites, μ was negatively correlated with the C-score (suggesting smaller patches under stronger competition), while positive correlations (suggesting larger patches under stronger competition) were observed at more arid sites. We propose that this is due to an increasing prevalence of competition transitivity as aridity increases. These findings broaden the emerging theory surrounding dryland patch size distributions

  13. 4-H and Iowa.

    ERIC Educational Resources Information Center

    Gore, Deborah, Ed.

    1988-01-01

    This issue focuses on Iowa's role in the historical development of the 4-H youth program. "Roots in Iowa" and "Jessie Field Shambaugh: The Mother of 4-H" (J. Friedel) describes the rural Iowan roots of the 4-H program, which today is located in 80 different countries, and give the story of its founder. Jessie Shambaugh, a rural Iowa teacher and…

  14. Patch-test-induced "flare-up" reactions to neomycin at prior biopsy sites.

    PubMed

    Jacob, Sharon E; Barland, Chantal; ElSaie, Mohamed L

    2008-01-01

    "Recall dermatitis" classically refers to the uncommon phenomenon of chemotherapy-induced reactivation of skin damage originally induced by radiotherapy months or years earlier. We compare this condition to ectopic flare-up reactions presenting as dermatitis at existing or previous sites by an inducing agent. Enhanced sensitization of an existent allergen by patch testing is rarely described. We describe a case of a 61-year-old man's developing localized allergic contact dermatitis at previous neomycin-treated sites following the diagnosis of neomycin sensitivity on patch testing, which we attribute to a "flare-up" phenomenon. PMID:19134429

  15. Predictive patch testing of "Medigloves" on humans using the repeated insult technique.

    PubMed

    Timpatanapong, P; Charuwichitratana, S; Rajatanavin, N; Sakuntapai, A

    1991-01-01

    The predictive patch tests using the repeated insult technique with pieces of ETO sterilized "Medigloves" on 200 human subjects showed negative allergic reactions in all cases. Therefore, the sensitizing potential of "Medigloves" is quite low, if any. Mild to severe forms of miliaria rubra were occasionally observed in about one fourth of the subjects during the induction and challenge periods since the weather was quite warm and humid. However, three subjects who developed more pronounced miliaria rubra on the skin underneath rubber-glove squares were selected for provocative use tests. The results were negative in all cases. A subject who showed a false-positive allergic reaction also showed negative results in a provocative use test and in patch tests with standard rubber chemicals and pieces of "Medigloves" from various batches. Occlusive patch tests for 72 hours with Mediglove pieces from the same batch used in the initial test challenge phase were repeatedly negative when performed during the cool time of the year. In tropical countries, predictive closed patch tests employing solid occlusive materials should be done during cool weather in order to prevent or minimize the occurrence of miliaria. In hot weather, this is a common source of false positive reactions. PMID:2026980

  16. Contact sensitization in 1094 children undergoing patch testing over a 7-year period.

    PubMed

    Seidenari, Stefania; Giusti, Francesca; Pepe, Patrizia; Mantovani, Lucia

    2005-01-01

    Contact sensitization in children is frequent. However, because exposure to sensitizing agents varies rapidly, it is of utmost importance to perform a periodic evaluation of patch test results. Our purpose was to compare our data on contact sensitization in children during the past 7 years to our previous 1988-1994 findings, in order to identify emerging allergens and update our pediatric series. From 1995 to 2001, 1094 consecutive children were examined. Of these, 997 patients were patch tested with our pediatric series, which includes 30 allergens, whereas 97 underwent patch testing with 46 allergens. A total of 570 children proved allergic (52.1%). The highest sensitization rate was observed in children under 3 years of age. No differences between atopic dermatitis patients and nonatopic ones were observed in the sensitization rate. Neomycin, nickel, wool alcohols, thimerosal, and ammoniated mercury gave most of the positive responses. With respect to 1988-1995 data, allergy to substances such as neomycin, nickel, wool alcohols, thimerosal, ammoniated mercury, propolis, potassium dichromate, and thiuram mix proved more frequent. In conclusion, as sensitization rates to different allergens show great variations over time, periodic evaluations of patch test results in children is necessary in order to update the test trays. PMID:15660887

  17. Nondestructive testing of surface-bonded piezoelectric patch actuators

    NASA Astrophysics Data System (ADS)

    Duerr, Johannes K.; Krohn, Nils; Nixdorf, Klaus; Luetze, Steffen; Herold-Schmidt, Ursula; Busse, Gerhard

    1999-07-01

    Introduction of new technologies to aerospace applications necessarily requires methods of non-destructive testing suitable to evaluate structural integrity. This important task also occurred when it was decided to develop and manufacture a large Fin-Box-Demonstrator equivalent to a fighter aircraft tail equipped with surface bonded piezoceramic actuators between DaimlerChrysler Aerospace - Military Aircraft Division and DaimlerChrysler Research and Technology. The objective of this project is to prove that structural vibrations of a fighter aircraft tail fin due to buffeting can be damped actively by means of surface bonded piezoceramic actuators.

  18. Degradation of triglycidyl isocyanurate as a cause of false-negative patch test reaction.

    PubMed

    Erikstam, U; Bruze, M; Goossens, A

    2001-01-01

    Triglycidyl isocyanurate (TGIC) is mainly used in polyester-based powder paints, but also in laminates, insulating varnishes, coatings and adhesives. Several cases of contact allergy to TGIC have been reported during the last 10 years. Contact allergy to TGIC has developed in a factory producing the chemical, in a factory producing powder paints containing TGIC, and in industries using powder coating. In this paper, we report a man who developed a work-related dermatitis when working on the painting of metal frames. He was exposed to polyester powder pigments containing TGIC. When patch tested, he was negative to TGIC (prepared in 1988) 3x and positive to polyester powder pigment. Only when a new test preparation of fresh TGIC powder was tested, was a positive reaction obtained. Chemical analyses showed that there was no TGIC in the test preparation from 1988, and that in the TGIC powder from 1988, there was only 30% of the expected amount of TGIC. The investigations, clinical and chemical, strongly indicate degradation of TGIC in the test preparation and powder. Both substances and the test preparations made from them may change over time. Therefore, if a false-negative reaction due to a test preparation is strongly suspected, we recommend a re-test of the patient with a new test preparation of fresh material. As a general rule, patch testing should be performed with fresh substances and test preparations made from them, unless their stability and durability are known. PMID:11156005

  19. Patch testing with patients' own cosmetics and toiletries--results of the IVDK*, 1998-2002.

    PubMed

    Uter, Wolfgang; Balzer, Christina; Geier, Johannes; Frosch, Peter J; Schnuch, Axel

    2005-10-01

    Patch test results with products brought in by the patients collected by the members of the Information Network of Departments of Dermatology (IVDK) between 1998 and 2002 were analysed. 5911 patients were patch tested with their own cosmetics and toiletries during this period. The 34 082 single test preparations applied to these 5911 patients were manually assigned to 1 of 26 categories, based on the EU Classification Annex I to 76/768/EEC, which had been further refined. The leave-on product category most commonly tested was 'creams, emulsions, lotions, gels and oils for the skin' (n = 3621 tested, n = 312 positive). The rinse-off product type most commonly tested was 'bath and shower preparations' (n = 1333 tested, n = 71 positive). In one-third of patients tested positive to these products, no other positive test result was observed. In the remainder, positive reactions to the fragrance mix, Myroxylon pereirae resin, methyldibromo glutaronitrile, (chloro-)methylisothiazolinone, 2-bromo-2-nitropropane-1,3-diole and further ingredients of cosmetics and toiletries were more common than in product-negative patients. However, in view of the potential for false-positive reactions mainly to rinse-off products, the results must be interpreted with caution. In conclusion, testing of patients' own products can be regarded as efficient and safe, if in accordance with current recommendations. PMID:16191021

  20. Outcome of a second patch test reading of TRUE Tests® on D6/7.

    PubMed

    Madsen, Jakob Torp; Andersen, Klaus Ejner

    2013-02-01

    Background. Two readings of patch test reactions are recommended. Objectives. To evaluate the outcome of a second patch test reading of TRUE Test® allergens on D6/7 in relation to negative or doubtful reactions on D3/4. Methods. This was a retrospective investigation of patch test data from January 1992 to October 2011 from consecutive eczema patients tested with the TRUE Test® panels. Results. In the period of nearly 20 years, a total of 9997 patients were tested. The total number of positive reactions to the 29 allergens was 6509; 4.4% were positive on D6/7 and negative on D3/4; and 9.1% were positive on D6/7 after a doubtful (?+) reaction on D3/4. Neomycin was the most frequent allergen giving delayed positive reactions (57%), followed by budesonide (42%) and hydrocortisone-17-butyrate (31%). Conclusion. A total of 4.4% of positive TRUE Test® reactions would be missed, and 9.1% might be missed, if only one reading was performed on D3/4. The results emphasize that many doubtful reactions at D3/4 may develop into positive reactions at a later reading. This may have important implications for evaluation of the clinical relevance of the test result. PMID:23289880

  1. Processing and Prolonged 500 C Testing of 4H-SiC JFET Integrated Circuits with Two Levels of Metal Interconnect

    NASA Technical Reports Server (NTRS)

    Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.; Krasowski, Michael J.; Prokop, Norman F.

    2015-01-01

    Complex integrated circuit (IC) chips rely on more than one level of interconnect metallization for routing of electrical power and signals. This work reports the processing and testing of 4H-SiC junction field effect transistor (JFET) prototype ICs with two levels of metal interconnect capable of prolonged operation at 500 C. Packaged functional circuits including 3-and 11-stage ring oscillators, a 4-bit digital to analog converter, and a 4-bit address decoder and random access memory cell have been demonstrated at 500 C. A 3-stage oscillator functioned for over 3000 hours at 500 C in air ambient.

  2. Processing and Prolonged 500 C Testing of 4H-SiC JFET Integrated Circuits with Two Levels of Metal Interconnect

    NASA Technical Reports Server (NTRS)

    Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.; Krasowski, Michael J.; Prokop, Norman F.

    2015-01-01

    Complex integrated circuit (IC) chips rely on more than one level of interconnect metallization for routing of electrical power and signals. This work reports the processing and testing of 4H-SiC junction field effect transistor (JFET) prototype IC's with two levels of metal interconnect capable of prolonged operation at 500 C. Packaged functional circuits including 3- and 11-stage ring oscillators, a 4-bit digital to analog converter, and a 4-bit address decoder and random access memory cell have been demonstrated at 500 C. A 3-stage oscillator functioned for over 3000 hours at 500 C in air ambient. Improved reproducibility remains to be accomplished.

  3. Review of magnetostrictive patch transducers and applications in ultrasonic nondestructive testing of waveguides.

    PubMed

    Kim, Yoon Young; Kwon, Young Eui

    2015-09-01

    A magnetostrictive patch transducer (MPT) is a transducer that exploits the magnetostrictive phenomena representing interactions between mechanical and magnetic fields in ferromagnetic materials. Since MPT technology was mainly developed and applied for nondestructive ultrasonic testing in waveguides such as pipes and plates, this paper will accordingly review advances of this technology in such a context. An MPT consists of a magnetic circuit composed of permanent magnets and coils, and a thin magnetostrictive patch that works as a sensing and actuating element which is bonded onto or coupled with a test waveguide. The configurations of the circuit and magnetostrictive patch therefore critically affect the performance of an MPT as well as the excited and measured wave modes in a waveguide. In this paper, a variety of state-of-the-art MPT configurations and their applications will be reviewed along with the working principle of this transducer type. The use of MPTs in wave experiments involving phononic crystals and elastic metamaterials is also briefly introduced. PMID:26048175

  4. Test/analysis comparison of piezoelectric patch local behavior for vibroacoustic active control application

    NASA Astrophysics Data System (ADS)

    Florens, Corine; Balmes, Etienne; Clero, Franck

    2007-04-01

    To predict the effect of active control on aircraft or helicopter trim panels, made with honeycomb sandwich composite, one approach consists in modeling the panel by Finite Element Method. FEM with shell elements for the laminate and volume elements for the core is classically used in industry; in a previous study the homogenized modeling approach has been validated. The aim of the present paper is to make a test/analysis comparison of the dynamic behavior of a honeycomb core sandwich beam actuated by a piezoelectric patch. More precisely, the behavior in the vicinity of the piezoelectric actuator is characterized, in order to validate the modeling approach of honeycomb sandwich composite equipped with piezoelectric patches.

  5. Testing metapopulation concepts: effects of patch characteristics and neighborhood occupancy on the dynamics of an endangered lagomorph

    USGS Publications Warehouse

    Eaton, Mitchell J.; Hughes, Phillip T.; Hines, James E.; Nichols, James D.

    2014-01-01

    Metapopulation ecology is a field that is richer in theory than in empirical results. Many existing empirical studies use an incidence function approach based on spatial patterns and key assumptions about extinction and colonization rates. Here we recast these assumptions as hypotheses to be tested using 18 years of historic detection survey data combined with four years of data from a new monitoring program for the Lower Keys marsh rabbit. We developed a new model to estimate probabilities of local extinction and colonization in the presence of nondetection, while accounting for estimated occupancy levels of neighboring patches. We used model selection to identify important drivers of population turnover and estimate the effective neighborhood size for this system. Several key relationships related to patch size and isolation that are often assumed in metapopulation models were supported: patch size was negatively related to the probability of extinction and positively related to colonization, and estimated occupancy of neighboring patches was positively related to colonization and negatively related to extinction probabilities. This latter relationship suggested the existence of rescue effects. In our study system, we inferred that coastal patches experienced higher probabilities of extinction and colonization than interior patches. Interior patches exhibited higher occupancy probabilities and may serve as refugia, permitting colonization of coastal patches following disturbances such as hurricanes and storm surges. Our modeling approach should be useful for incorporating neighbor occupancy into future metapopulation analyses and in dealing with other historic occupancy surveys that may not include the recommended levels of sampling replication.

  6. Analysis of skin patch test results and metalloproteinase-2 levels in a patient with contact dermatitis

    PubMed Central

    Czajkowski, Rafał; Kowaliszyn, Bogna; Żbikowska-Gotz, Magdalena; Bartuzi, Zbigniew

    2015-01-01

    Introduction The complex course of skin reactions that contact eczema involves is due in part to abnormalities of the extracellular matrix function. Proteins that degrade extracellular matrix components include metalloproteinases (MMP), which are divided into subcategories depending on the chemical structure and substrate specificity. Aim To analyse patch test results in contact dermatitis patients and to assess MMP-2 levels during skin lesion exacerbation and remission. Material and methods Fifty patients suffering from contact eczema were qualified to the study and 20 healthy volunteers as a control group. The study group patients had epidermal skin tests performed with the “European Standard” set. To assess the MMP-2 level in serum, venous blood was drawn, twice from study group patients – during contact dermatitis exacerbation and remission periods – and once from control group patients. Assessment of MMP-2 in serum was done with ELISA immunoassay. To verify the proposed hypotheses, parametric and nonparametric significance tests were used. Results Hands were the most frequent location of contact dermatitis. Nickel (II) sulphate was the most frequent sensitizing substance. Mean MMP-2 levels were statistically higher in the study group both in contact dermatitis exacerbation and remission periods than in the control group. There was no statistically significant difference between MMP-2 levels and skin patch test results. Conclusions Nickel is one of the most allergenic contact allergens in patients with contact dermatitis. Metalloproteinase-2 is a good marker of contact dermatitis in various stages of the disease. PMID:26161054

  7. In pursuit of defining clinical relevance of positive patch tests results.

    PubMed

    Wolf, Ronni; Davidovici, Batya; Stone, Stephen P; Tuzun, Yalcin

    2007-01-01

    According to the current classification of clinical relevance of the positive patch test reactions, the positive results of patients who are allergic to various allergens that are not responsible for the present dermatitis do not fit into the category of "relevant to present dermatitis" but should be defined as "relevant to a preceding bout of dermatitis." This seems to us inappropriate and misleading because reexposure to the sensitizing agent would quickly revert their reaction to "relevant to present dermatitis." We suggest an alternative possibility to the current division of the various types of clinical relevance, namely, "relevance to a present allergy other than the presenting dermatitis." PMID:17870528

  8. Patch-test results in children and adolescents: systematic review of a 15-year period*

    PubMed Central

    Rodrigues, Dulcilea Ferraz; Goulart, Eugênio Marcos Andrade

    2016-01-01

    The number of studies on patch-test results in children and adolescents has gradually increased in recent years, thus stimulating reviews. This paper is a systematic review of a 15-year period devoted to studying the issue. Variations pertaining to the number and age groups of tested children and/or adolescents, the number of subjects with atopy/atopic dermatitis history, the quantity, type and concentrations of the tested substances, the test technique and type of data regarding clinical relevance, must all be considered in evaluating these studies, as they make it harder to formulate conclusions. The most common allergens in children were nickel, thimerosal, cobalt, fragrance, lanolin and neomycin. In adolescents, they were nickel, thimerosal, cobalt, fragrance, potassium dichromate, and Myroxylon pereirae. Knowledge of this matter aids health professionals in planning preventive programs aimed at improving children's quality of life and ensuring that their future prospects are not undermined. PMID:26982781

  9. Patch-test results in children and adolescents: systematic review of a 15-year period.

    PubMed

    Rodrigues, Dulcilea Ferraz; Goulart, Eugênio Marcos Andrade

    2016-02-01

    The number of studies on patch-test results in children and adolescents has gradually increased in recent years, thus stimulating reviews. This paper is a systematic review of a 15-year period devoted to studying the issue. Variations pertaining to the number and age groups of tested children and/or adolescents, the number of subjects with atopy/atopic dermatitis history, the quantity, type and concentrations of the tested substances, the test technique and type of data regarding clinical relevance, must all be considered in evaluating these studies, as they make it harder to formulate conclusions. The most common allergens in children were nickel, thimerosal, cobalt, fragrance, lanolin and neomycin. In adolescents, they were nickel, thimerosal, cobalt, fragrance, potassium dichromate, and Myroxylon pereirae. Knowledge of this matter aids health professionals in planning preventive programs aimed at improving children's quality of life and ensuring that their future prospects are not undermined. PMID:26982781

  10. Noninvasive in vivo confocal laser scanning microscopy is effective in differentiating allergic from nonallergic equivocal patch test reactions.

    PubMed

    Slodownik, D; Levi, A; Lapidoth, M; Ingber, A; Horev, L; Enk, C D

    2015-04-01

    Patch testing is the gold standard for the validation of contact dermatitis. It relies on the subjective scoring by an evaluator of the inflammatory reaction induced by an allergen applied to the skin. Equivocal reactions imply faint erythema and could represent allergic, irritant, or negative reactions. They constitute approximately 1 % of the positive reactions encountered in patch test practice. Histological evaluation of the equivocal reaction has proven helpful for the correct interpretation but is however time consuming, and its invasive nature is often unacceptable to the patient. In vivo confocal laser scanning microscopy (CLSM) is a novel, noninvasive imaging technique which permits real-time visualization of skin structures and lesions at a resolution close to that obtained by conventional histology. CLSM has been successfully applied for the differentiation between clinically clear-cut allergic and irritant patch test reactions. The objective of this study is to determine the relevance of CLSM in differentiating between allergic, irritant, and negative equivocal patch test reactions. Fifteen patients who underwent patch testing in our clinic were observed as having 20 equivocal reactions. All 20 reactions were evaluated using in vivo CLSM and compared with adjacent normal skin. In vivo CLSM evaluation revealed that 8 of the 20 equivocal reactions (40 %) showed confocal patterns consistent with the patterns encountered in positive allergic reactions. Anamnestic exposure, i.e., detailed assessment of previous related contact with these allergens, confirmed high relevance rates. In vivo CLSM is useful in differentiating between allergic, irritant, and negative equivocal patch test reactions, a differentiation that cannot be made by conventional clinical patch test reading. PMID:25604734

  11. DKG statement on the use of metal alloy discs for patch testing in suspected intolerance to metal implants.

    PubMed

    Thomas, Peter; Geier, Johannes; Dickel, Heinrich; Diepgen, Thomas; Hillen, Uwe; Kreft, Burkhard; Schnuch, Axel; Szliska, Christiane; Mahler, Vera

    2015-10-01

    Intolerance reactions to metal implants may be caused by metal allergy. However, prior to implantation, 'prophetic'/prophylactic patch testing should not be performed. Pre-implant patch testing should only be done to verify or exclude metal allergy in patients with a corresponding history. In case of implant-related complications - in particular following replacement arthroplasty - such as pain, effusion, skin lesions, reduced range of motion or implant loosening, orthopedic causes should be ruled out first. Workup of suspected metal implant allergy should then be done using the DKG standard series, which includes nickel, cobalt, and chromium preparations. Various studies assessing the usefulness of metal alloy discs for patch testing have shown this particular approach to be ineffective with respect to providing reliable information on metal allergy. Any positive reaction in such tests cannot be assigned to a specific metal contained within the alloy. Furthermore, there is a risk of broad and indiscriminate use of these readily available discs. Accordingly, given the lack of additional benefit compared to patch testing with standardized metal salt preparations, we do not recommend patch testing with metal alloy discs. PMID:26408461

  12. Clutter sensitivity test under controlled field conditions Resonant Microstrip Patch Antenna (RMPA) sensor technology

    SciTech Connect

    1996-06-27

    Theoretical research, controlled laboratory tests, and these field test results show that nonmetallic (and metallic) shallowly buried objects can be detected and imaged with the Resonant Microstrip Patch Antenna (RMPA) sensor. The sensor can be modeled as a high Q cavity which capitalizes on its resonant condition sensitivity to scattered waves from buried objects. When the RMPA sensor is swept over a shallowly buried object, the RMPA fed-point impedance (resistance), measured with a Maxwell bridge, changes by tens of percent. The significant change in unprocessed impedance data can be presented in two-dimensional and three-dimensional graphical displays over the survey area. This forms silhouette images of the objects without the application of computationally intensive data processing algorithms. Because RMPA employed electromagnetic waves to illuminate the shallowly buried object, a number of questions and issues arise in the decision to fund or deny funding of the reconfiguration of the RMPA technology into a nonmetallic (metallic) land mine detector.

  13. Adhesion molecules in atopic dermatitis: patch tests elicited by house dust mite.

    PubMed

    Jung, K; Linse, F; Pals, S T; Heller, R; Moths, C; Neumann, C

    1997-10-01

    Different T-helper subsets, which are characterized by the secretion of distinct cytokines (Th1, Th2), have been found in house dust mite-exposed skin of sensitized individuals and in nickel-specific T lymphocytes from nickel contact allergic and non-allergic individuals. In order to evaluate the role which adhesion molecules may play in the homing of different T-cell subsets into allergen-exposed skin of atopic and normal individuals, we compared the expression pattern of adhesion molecules in patch test reactions to house dust mite antigen (D.pt.), nickel sulfate (Ni) and the irritant anthralin. Biopsies were taken at various time points after application of these agents and studied by immuncytochemistry. To exclude an endogenous difference in adhesion molecule expression in atopic and non-atopic skin, sequential biopsies from Ni patch tests of 2 normal individuals were also included in this study. The expression of E-selectin, P-selectin, CD31, VCAM-1 and ICAM-1 on endothelial cells and other cells in the skin was quantified by microscopic evaluation. Skin homing T cells were also quantified using antibodies to CD3, CD4, CD8, UCHL-1, L-selectin and the cutaneous lymphocyte antigen (CLA). Independent of the eliciting substance, all lesions showed an upregulation of all adhesion molecules tested, with the exception of CD62. The appearance of E-selectin and an increase in ICAM-1 and VCAM-1 expression were first observed at 12 h after application of the various agents. In parallel, the number of CLA+ and L-selectin+ lymphocytes increased steadily. No principle differences could be established between the various types of skin reactions in atopic individuals, nor did the skin of patients with AD differ from normal controls. Our results provide evidence that differential expression of adhesion molecules does not play a major part in observed differential homing of Th1 and Th2-cell subsets into patch test sites provoked by house dust mite and nickel sulfate in atopic

  14. Intradermal Tests for Diagnosis of Drug Allergy are not Affected by a Topical Anesthetic Patch.

    PubMed

    Couto, Mariana; Silva, Diana; Ferreira, Ana; Cernadas, Josefina R

    2014-09-01

    The use of topical anesthesia to perform intradermal tests (IDTs) for drug allergy diagnosis was never investigated. We aimed to determine the effects of a topical anesthetic patch containing prilocaine-lidocaine on wheal size of IDT with drugs. Patients who had positive IDT as part of their investigation process of suspected drug hypersensitivity were selected. IDT were performed according to guidelines. Anesthetic patch (AP) was placed and the same prior positive IDT, as well as positive histamine skin prick test (SPT) and negative (saline IDT) controls, were performed in the anesthetized area. Patients with negative IDT were also included to check for false positives with AP. Increase in wheals after 20 minutes both with and without AP was recorded and compared. 45 IDT were performed (36 patients), of which 37 have been previously positive (14 antibiotics, 10 general anesthetics, 6 non-steroidal anti-inflammatory drugs, 3 iodinated contrasts, 3 anti-Hi-histamines and 1 ranitidine). Mean histamine SPT size without the AP was 4.7 mm [95%CI (4.4-5.1]), and 4.6 mm [95%CI(4.2-5.0)] with anesthesia. Mean wheal increase in IDT for drugs without the anesthesia was 4.5 mm [95%CI(3.3-5.7)] and with anesthesia was 4.3 mm [95%CI(2.8-5.8)]. No statistical significant differences were observed between skin tests with or without AP for histamine SPT (P=0.089), IDT with saline (P=0.750), and IDT with drugs (P=0.995). None of the patients with negative IDT showed positivity with the AP, or vice-versa. The use of an AP containing prilocaine-lidocaine does not interfere with IDT to diagnose drug allergy, and no false positive tests were found. PMID:25229004

  15. Patch test results in patients with allergic contact dermatitis in the Podlasie region

    PubMed Central

    Bacharewicz, Joanna; Pawłoś, Anna

    2013-01-01

    Introduction The aim of the study was to provide current data on the incidence of allergy to various contact allergens in patients with allergic contact eczema and the analysis of selected socio-demographic data of the patients. Material and methods The study included 1532 patients (1010 women and 522 men) treated for allergic contact dermatitis at the Department of Dermatology and Venereology and at the Dermatology Outpatient Clinic in Bialystok in 2007–2011. The assessment of selected demographic data and skin lesions was based on the MOAHFLA index, while the results of patch tests were analyzed with modified Baseline European Series consisting of 31 allergens. Results In the group of patients with eczema, 34.1% were men, and 55% of all respondents were people over 40 years of age. The occupational character of skin lesions was found in 22.5%. Most frequently (38.9%) skin lesions were localized on the hands, rarely involved legs (3.98%). Atopic dermatitis was diagnosed in 4.5% of patients. The ten most frequent allergens were: nickel sulfate (24%), cobalt chloride (15.3%), fragrance mix (8.25%), potassium dichromate (6.8%), balsam of Peru (5.5%), neomycin (4.42%), paraphenylenediamine (3.85%), Quatermium-15 (2.1%), detreomycin (1.83%) and budesonide (1.44% of tested patients). Conclusions Frequent allergy to detreomycin indicates the need of patch testing for this allergen of all examined patients with allergic contact dermatitis. The increased frequency of the nickel allergy is a worrying problem and indicates the need for education about the risk factors for nickel allergy development and the implementation of appropriate legal regulations. PMID:24493997

  16. Patch testing with oxidized R-(+)-limonene and its hydroperoxide fraction.

    PubMed

    Matura, Mihály; Goossens, An; Bordalo, Olivia; Garcia-Bravo, Begoña; Magnusson, Kerstin; Wrangsjö, Karin; Karlberg, Ann-Therese

    2003-07-01

    R-(+)-Limonene is an ubiquitous allergen in our environment. It is one of the most widely used fragrance materials not only in fine fragrances but also most often incorporated in domestic and occupational products. Although the non-oxidized R-(+)-limonene itself is not allergenic, it easily forms allergenic products due to autoxidation during handling and storage. 2273 patients at 4 dermatological clinics in Europe were patch tested between 1997 and 1999 in 2 steps. First, the oxidation mixture of R-(+)-limonene and 1 selected allergen fraction of the mixture, the limonene hydroperoxides, were tested in 2 different vehicles in consecutive patients. A diverging frequency of positive patch test reactions was observed in the 4 clinics. 3.8% of the consecutive patients tested reacted to oxidized R-(+)-limonene in 2 clinics, 6.5% in the 3rd, whereas 0.3% in the 4th clinic. In 2 of the centres, different but significant concomitant positive response rates to other allergens were observed; e.g. to fragrance materials and to colophonium. However, in the total test population, 57% of the limonene-allergic subjects did not react to any of the fragrance allergy markers used in the standard series. In the 2nd step, patients showing positive reactions were retested, also including additional separate allergens of the limonene oxidation mixture (carvone and limonene oxide). 60% of the limonene-allergic patients showed positive results at retesting. The limonene hydroperoxide fraction was proved to be the most important allergen of the oxidation mixture, showing positive reactions in around 60% of the limonene-allergic patients at both test sessions. Testing limonene oxide and carvone separately resulted in very few positive reactions. 3% oxidized R-(+)-limonene in non-stabilized petrolatum is most suitable when using only 1 test preparation for diagnosis of contact allergy to oxidized limonene. Our data give clinical support to the European classification of R

  17. Patch test standard series recommended by the Brazilian Contact Dermatitis Study Group during the 2006-2011 period*

    PubMed Central

    Duarte, Ida Alzira Gomes; Tanaka, Greta Merie; Suzuki, Nathalie Mie; Lazzarini, Rosana; Lopes, Andressa Sato de Aquino; Volpini, Beatrice Mussio Fornazier; de Castro, Paulo Carrara

    2013-01-01

    A retrospective study was carried out between 2006-2011. Six hundred and eighteen patients with suspected allergic contact dermatitis underwent the standard patch test series recommended by the Brazilian Contact Dermatitis Research Group. The aim of our study was to evaluate the variation of positive patch-test results from standard series year by year. The most frequently positive allergens were: nickel sulfate, thimerosal and potassium bichromate. Decrease of positive patch-test results over the years was statistically significant for: lanolin (p=0.01), neomycin (p=0.01) and anthraquinone (p=0.04). A follow-up study should be useful in determining which allergens could be excluded from standard series, as they may represent low sensitization risk. PMID:24474122

  18. Patch test standard series recommended by the Brazilian Contact Dermatitis Study Group during the 2006-2011 period.

    PubMed

    Duarte, Ida Alzira Gomes; Tanaka, Greta Merie; Suzuki, Nathalie Mie; Lazzarini, Rosana; Lopes, Andressa Sato de Aquino; Volpini, Beatrice Mussio Fornazier; Castro, Paulo Carrara de

    2013-01-01

    A retrospective study was carried out between 2006-2011. Six hundred and eighteen patients with suspected allergic contact dermatitis underwent the standard patch test series recommended by the Brazilian Contact Dermatitis Research Group. The aim of our study was to evaluate the variation of positive patch-test results from standard series year by year. The most frequently positive allergens were: nickel sulfate, thimerosal and potassium bichromate. Decrease of positive patch-test results over the years was statistically significant for: lanolin (p=0.01), neomycin (p=0.01) and anthraquinone (p=0.04). A follow-up study should be useful in determining which allergens could be excluded from standard series, as they may represent low sensitization risk. PMID:24474122

  19. Immunoglobulin E-Mediated Allergy Plays a Role in Atopic Eczema as Shown in the Atopy Patch Test

    PubMed Central

    2008-01-01

    Although the pathophysiology of immunoglobulin E (IgE)-mediated allergic rhinoconjunctivitis and bronchial asthma is rather well established, the role of allergy in atopic eczema (AE) is still controversial. By a technique called atopy patch test, aeroallergens like house dust mite, animal dander, or pollen were proven as relevant trigger factors in a subgroup of patients with AE. The atopy patch test is an epicutaneous patch test with such allergens known to elicit IgE-mediated reactions, and used for the evaluation of eczematous skin reactions. In a series of single-center and multicenter studies, a method was developed, standardized, and compared with other diagnostic techniques (radioallergosorbent test, skin prick test) in AE patients. With regard to clinical history, the most specific results were obtained with the atopy patch test (allergen-dependent, 69%-92%), whereas sensitivity was higher for skin prick test (range, 69%-82%) and specific IgE (range, 65%-94%). The characterization of a patient subgroup with relevant IgE-mediated allergy may lead to more efficient avoidance and eventually even specific immunotherapy strategies in the management of AE. PMID:23283386

  20. Identification and testing of early indicators for N leaching from urine patches.

    PubMed

    Vogeler, Iris; Cichota, Rogerio; Snow, Val

    2013-11-30

    Nitrogen leaching from urine patches has been identified as a major source of nitrogen loss under intensive grazing dairy farming. Leaching is notoriously variable, influenced by management, soil type, year-to-year variation in climate and timing and rate of urine depositions. To identify early indicators for the risk of N leaching from urine patches for potential usage in a precision management system, we used the simulation model APSIM (Agricultural Production Systems SIMulator) to produce an extensive N leaching dataset for the Waikato region of New Zealand. In total, nearly forty thousand simulation runs with different combinations of soil type and urine deposition times, in 33 different years, were done. The risk forecasting indicators were chosen based on their practicality: being readily measured on farm (soil water content, temperature and pasture growth) or that could be centrally supplied to farms (such as actual and forecast weather data). The thresholds of the early indicators that are used to forecast a period for high risk of N leaching were determined via classification and regression tree analysis. The most informative factors were soil temperature, pasture dry matter production, and average soil water content in the top soil over the two weeks prior to the urine N application event. Rainfall and air temperature for the two weeks following urine deposition were also important to fine-tune the predictions. The identified early indicators were then tested for their potential to predict the risk of N leaching in two typical soils from the Waikato region in New Zealand. The accuracy of the predictions varied with the number of indicators, the soil type and the risk level, and the number of correct predictions ranged from about 45 to over 90%. Further expansion and fine-tuning of the indicators and the development of a practical N risk tool based on these indicators is needed. PMID:24064140

  1. Atopy patch test for the diagnosis of food protein-induced enterocolitis syndrome.

    PubMed

    Fogg, Matthew I; Brown-Whitehorn, Terri A; Pawlowski, Nicholas A; Spergel, Jonathan M

    2006-08-01

    Food protein-induced enterocolitis syndrome (FPIES) is thought to be a non-IgE mediated food allergy syndrome. Affected infants typically demonstrate gastrointestinal symptoms after hours after ingestion of the offending food. Traditional allergy testing is not useful for this disorder because tests for food specific IgE are routinely negative. A diagnostic oral food challenge (OFC) is the only method to confirm the diagnosis of FPIES. This prospective study was undertaken to determine whether the atopy patch test (APT) is able to predict the results of the OFC. Nineteen infants with suspected FPIES by clinical history underwent APT to the suspected foods. After APT was performed, subjects underwent OFC to determine whether FPIES was present. The results of APT and OFC were compared and used to calculate sensitivity and specificity of the APT. APT predicted the results of oral food challenges in 28/33 instances. There were 16 cases of FPIES confirmed by oral food challenges. In all 16 cases of FPIES, the APT was positive to the suspected food. However, the APT was positive in five instances where the oral food challenge was negative. All 12 patients with a negative APT had a negative oral food challenge to the suspected food. APT appears to be a promising diagnostic tool for the diagnosis of FPIES. PMID:16846453

  2. Testing the Palma-Clary Reduced Dimensionality Model Using Classical Mechanics on the CH4 + H → CH3 + H2 Reaction.

    PubMed

    Vikár, Anna; Nagy, Tibor; Lendvay, György

    2016-07-14

    Application of exact quantum scattering methods in theoretical reaction dynamics of bimolecular reactions is limited by the complexity of the equations of nuclear motion to be solved. Simplification is often achieved by reducing the number of degrees of freedom to be explicitly handled by freezing the less important spectator modes. The reaction cross sections obtained in reduced-dimensionality (RD) quantum scattering methods can be used in the calculation of rate coefficients, but their physical meaning is limited. The accurate test of the performance of a reduced-dimensionality method would be a comparison of the RD cross sections with those obtained in accurate full-dimensional (FD) calculations, which is not feasible because of the lack of complete full-dimensional results. However, classical mechanics allows one to perform reaction dynamics calculations using both the RD and the FD model. In this paper, an RD versus FD comparison is made for the 8-dimensional Palma-Clary model on the example of four isotopologs of the CH4 + H → CH3 + H2 reaction, which has 12 internal dimensions. In the Palma-Clary model, the only restriction is that the methyl group is confined to maintain C3v symmetry. Both RD and FD opacity and excitation functions as well as differential cross sections were calculated using the quasiclassical trajectory method. The initial reactant separation has been handled according to our one-period averaging method [ Nagy et al. J. Chem. Phys. 2016, 144, 014104 ]. The RD and FD excitation functions were found to be close to each other for some isotopologs, but in general, the RD reactivity parameters are lower than the FD reactivity parameters beyond statistical error, and for one of the isotopologs, the deviation is significant. This indicates that the goodness of RD cross sections cannot be taken for granted. PMID:26918703

  3. Evaluation of Suspected Cosmetic Induced Facial Dermatoses with the Use of Indian Standard Series and Cosmetic Series Patch Test

    PubMed Central

    Rastogi, Madhur Kant; Gupta, Astha; Soodan, Puneet Singh; Gahalaut, Pratik

    2015-01-01

    Introduction: Awareness about skin beauty or cosmetic elegance has received worldwide attention in the present day youth oriented society. Along with careful detailed history and thorough examination patch test is considered cornerstone in diagnosis of allergic contact dermatitis. Materials and Methods: Fifty patients suspected clinical diagnosis of contact facial dermatitis due to attended the Department of Dermatology, were included in a hospital based study. The patch test was applied on the upper back of using 32 allergens present in Indian cosmetic series and 20 known allergens in Indian standard battery series procured from Systopic Pharmaceutical Ltd, after applying the patch test, the patient was asked to come after 48h and 72h for reading the results of the patch test. Results: Out of 50 patients there were 32 (64%) females (housewives 36%) patients and 18 (36%) male (farmers 12%). Itching was the most common presenting symptom in 39 patients (78%) least was hypopigmentation and pain in 2%. Forehead was the most common site of involvement in 25 patients (50%) least were cheeks in 15 patients (30%). Erythema was the commonest morphological presentation seen in 36 patients (72%). Hair dye was suspected in maximum number of patients that is 13 (26%). Most common antigen showing patch test positivity was paraphenylenediamine in nine patients (18%). There are significantly more chances of developing positive test reaction with Indian standard series compared to cosmetic series. (p=.0053 using Fischer Exact test). Conclusion: In India there is no legislation regarding labeling ingredients on cosmetics as in the western countries, so labelling of the contents of cosmetic products should be the main challenge in cosmetic dermatitis is to identify. PMID:25954688

  4. Patch testing with hair cosmetic series in Europe: a critical review and recommendation.

    PubMed

    Uter, Wolfgang; Bensefa-Colas, Lynda; Frosch, Peter; Giménez-Arnau, Ana; John, Swen M; Lepoittevin, Jean-Pierre; Lidén, Carola; White, Ian R; Duus Johansen, Jeanne

    2015-08-01

    Many key ingredients of hair cosmetics (in particular, dyes, bleaches, and hair-styling agents) are potent (strong to extreme) contact allergens. Some heterogeneity is apparent from published results concerning the range of allergens for which patch testing is important. The objective of the present review was to collect information on the current practice of using 'hair cosmetic series', and discuss this against the background of evidence concerning consumer/professional exposure and regulatory aspects to finally derive a recommendation for a 'European hair cosmetic series'. The methods involved (i) a survey targeting all members of the COST action 'StanDerm' (TD1206) consortium, (ii) analysis of data in the database of the European Surveillance System on Contact Allergies (ESSCA), and (iii) literature review. Information from 19 European countries was available, partly from national networks, and partly from one or several departments of dermatology or, occasionally, occupational medicine. Apart from some substances being tested only in single departments, a broad overlap regarding 'important' allergens was evident. Some of the substances are no longer permitted for use in cosmetics (Annex II of the Cosmetics Regulation). An up-to-date 'European hair cosmetics series', as recommended in the present article, should (i) include broadly used and/or potent contact allergens, (ii) eliminate substances of only historical concern, and (iii) be continually updated as new evidence emerges. PMID:26080054

  5. Are contact allergens stable in patch test preparations? Investigation of the degradation of d-limonene hydroperoxides in petrolatum.

    PubMed

    Nilsson, U; Magnusson, K; Karlberg, O; Karlberg, A T

    1999-03-01

    Several of the products formed after oxidation of d-limonene exhibit strong contact allergenic properties. Some, e.g., the hydroperoxides, are unstable compounds. In this study, we have examined whether the limonene hydroperoxides are chemically stable in white petrolatum used for patch testing. We found that the stability of the hydroperoxides was strongly dependent on whether or not the petrolatum was stabilized with alpha-tocopheryl acetate. In the presence of this antioxidant, the hydroperoxides were degraded to a greater extent. The hydroperoxides were shown to be directly reduced to the corresponding alcohols by this agent. On the other hand, the compounds where shown to be stable in non-stabilized petrolatum throughout clinical patch testing for a period of 6 weeks, provided that the preparations were stored in a refrigerator when not used. Thus, it is recommended that vehicles without alpha-tocopheryl acetate are used when peroxy or hydroperoxy compounds are patch tested or used in sensitization experiments. However, it is important to limit the storage time so that optimal conditions are at hand. A fast method was developed to enable isolation and quantification of the hydroperoxides in white petrolatum. This analytical method may also be applicable to other compositions of patch test preparations. PMID:10073439

  6. Pre-treatment of nickel test areas with sodium lauryl sulfate detects nickel sensitivity in subjects reacting negatively to routinely performed patch tests.

    PubMed

    Seidenari, S; Motolese, A; Belletti, B

    1996-02-01

    A fair % of patients with a clinical history of nickel allergy show negative patch test results. To improve the response rate to NiSO4 5% pet. patch tests, a testing procedure utilizing pre-treatment of the test area by a 24-h application of sodium lauryl sulfate (SLS) was introduced. 46 women with a clinical history of nickel sensitivity, who exhibited negative reactions to nickel sulfate 5% pet. patch tests, were studied. Patients underwent 6 patch tests on adjacent sites on the volar surface of the forearms. 4 patch tests were performed with a 72-h application of 40 mg nickel sulfate 5% pet. While 1 of these patch tests served as control, 3 test areas underwent 24-h pre-treatment with 40 microliters SLS, 1 with 0.1% and 2 with 0.5% solution. To evaluate differences in the reactivity to SLS plus nickel sulfate related to the site on the forearm, 0.5% SLS pre-treatment was performed both on a proximal and on a distal test site. At the 72-h evaluation, 19 subjects out of 46 showed positive reactions to nickel sulfate 5% pet. at skin sites pre-treated with 0.1% SLS, whereas 23 patients reacted positively at 0.5% SLS pre-treated areas. Echographic values of skin thickness and of hypo-echogenic dermal areas at positive pre-treated nickel test areas were higher than at control test areas, confirming the clinical evidence of an increased response to NiSO4 after SLS pre-treatment. The inflammatory reaction, as evaluated clinically and echographically, was much higher at distal skin areas (0.1% SLS and distal 0.5% SLS) than at proximal 0.5% SLS ones. PMID:8681564

  7. Food allergy-related paediatric constipation: the usefulness of atopy patch test.

    PubMed

    Syrigou, Ekaterini I; Pitsios, Constantinos; Panagiotou, Ioanna; Chouliaras, Georgios; Kitsiou, Sofia; Kanariou, Mary; Roma-Giannikou, Eleftheria

    2011-09-01

    The aims of this study were to evaluate the implication of food allergy as a cause of paediatric constipation and to determine the diet period needed to tolerate the constipation-causing foods. Fifty-four children aged 6 months to 14 years (median, 42 months) suffering from chronic constipation (without anatomic abnormalities, cοeliac disease or hypothyroidism), unresponsive to a 3-month laxative therapy, were prospectively evaluated. All participants were evaluated for allergy to cow's milk, egg, wheat, rice, corn, potato, chicken, beef and soy, using skin tests (SPT), serum specific IgE and atopy patch test (APT). A withdrawal of the APT-positive foods was instructed. Thirty-two children had positive APT; 15 were positive to one; six, to two and 11, to three or more food allergens, wheat and egg being the commonest. After withdrawing the APT-positive foods for an 8-week period, constipation had improved in 28/32 children, but a relapse of constipation was noticed after an oral food challenge, so they continued the elimination diet. Tolerance to food allergens was achieved in only 6/28 after 6 months, compared to 25/28 after 12 months and to all after a 2-year-long elimination. Food allergy seems to be a significant etiologic factor for chronic constipation not responding to treatment, in infants and young children. APT was found to be useful in evaluating non-IgE allergy-mediated constipation, and there was no correlation of APT with IgE detection. Tolerance was adequately achieved after 12 months of strict food allergen elimination. PMID:21347849

  8. Usefulness of Atopy Patch Test on a child with milk protein-induced enterocolitis syndrome: a case report.

    PubMed

    Scaparrotta, A; Di Pillo, S; Consilvio, N P; Attanasi, M; Cingolani, A; Rapino, D; Cerasa, M; Pucci, N; Di Gioacchino, M; Chiarelli, F

    2013-01-01

    We describe the case of a child affected by milk-protein induced enterocolitis, in which oral challenge with corn was performed without symptoms after a negative specific Atopy Patch Test. Food protein-induced enterocolitis syndrome (FPIES) is an uncommon nonIgE-mediated gastrointestinal food hypersensitivity of infancy, characterized by severe vomiting and diarrhea arising within 1 to 3 hours after ingestion of the causative food. Little is known about the pathophysiology of FPIES. The absence of food-specific IgE as demonstrated by negative skin prick tests suggests that the disease is not caused by an early onset IgE-mediated reaction. Atopy Patch Test has been described as sensitive and predictive in this syndrome. The hypothesis on the immunological pathogenesis has been discussed on the basis of literature data. PMID:24067480

  9. Salmon Patch

    MedlinePlus

    ... the head. Salmon patches are different from port-wine stains (discussed as a separate topic) in that ... difference between a salmon patch and a port-wine stain. In the past, port-wine stains and ...

  10. Multi-state 4-H energy program

    SciTech Connect

    Bakker, U.B.; Garthe, J.W.

    1983-06-01

    Through Agricultural Engineering 4-H Energy Programs, youth can be educated to gain knowledge, increase hands on skills, and incorporate energy-saving techniques into their lifestyle. In a pilot multi-state energy program tested by 13 states, youth increased their energy awareness.

  11. Ciprofloxacin-induced acute generalized exanthematous pustulosis mimicking bullous drug eruption confirmed by a positive patch test.

    PubMed

    Hausermann, P; Scherer, K; Weber, M; Bircher, A J

    2005-01-01

    We report the case of an 80-year-old woman presenting with ciprofloxacin-induced acute generalized exanthematous pustulosis (AGEP) confirmed by a positive patch test. Cutaneous morphology, course and histological findings were consistent with a definite diagnosis according to the AGEP validation score of the EuroSCAR study group. We point to the rarity of quinolone-induced AGEP and discuss immunological mechanisms, the value of in vivo and in vitro tests as well as the main differential diagnosis. Furthermore, we highlight in this particular case the challenging differentiation from bullous drug eruption. PMID:16205075

  12. 4-H Club Goat Guide.

    ERIC Educational Resources Information Center

    Brown, R. Kipp

    This guide provides information for 4-H Club members who have decided on a club goat project. Topics include general information in the following areas: show rules; facilities and equipment (barns/sheds, fences, feeders, water containers, and equipment); selection (structural correctness, muscle, volume and capacity, style and balance, and growth…

  13. Recruiting 4-H Volunteer Leaders.

    ERIC Educational Resources Information Center

    National Four-H Club Foundation, Washington, DC.

    The guide is intended to assist 4-H Club extension workers in recruiting volunteer adult and youth leaders. It discusses: why volunteers serve (organizational identity, desire to serve, involvement of other family members, future opportunities and obligations, community status, self interest, and public opinion); how to recruit (person-to-person…

  14. Eosinophilic airway disease in a patient with a negative skin prick test, but a positive patch test with platinum salts--implications for medical surveillance.

    PubMed

    Merget, Rolf; Fartasch, Manigé; Sander, Ingrid; Van Kampen, Vera; Raulf, Monika; Brüning, Thomas

    2015-09-01

    We present the case of a 52-year-old woman with a topic dermatitis since adolescence who developed work-related hand eczema, cough and runny nose 12 years after she had started working as a laboratory technician at a precious metals refinery. While skin prick test with sodium hexachloroplatinate (SPTPt ) was negative, patch testing with ammonium tetrachloroplatinate was positive after 24, 48, 72, and 96 hr. Inhalation challenge with sodium hexachloroplatinate yielded cough, mild shortness of breath, and a maximal decrease of FEV1 of 8% from baseline 24 hr after the challenge. Significant increases of bronchial hyperresponsiveness, exhaled nitric monoxide and sputum eosinophils were documented after the challenge. We conclude that eosinophilic airway disease due to platinum salts may occur in SPTPt negative subjects. Both, patch testing and inhalation challenge with platinum salts should be considered in SPT negative subjects with occupational exposure to precious metal salts and work-related allergic symptoms. PMID:26010732

  15. Methyl esterification of 15-hydroperoxyabietic acid does not affect the patch-test result in colophonium allergic patients.

    PubMed

    Karlberg, Ann-Therese; Bråred-Christensson, Johanna; Börje, Anna; Harambasic, Elma; Matura, Mihàly

    2007-06-01

    Colophonium (gum rosin) consists of numerous compounds. We have previously shown that abietic acid (Fig. 1), the major compound in gum rosin, is oxidized to strong contact allergens at air exposure (1). The most potent allergen identified is 15-hydroperoxyabietic acid (15-HPA, Fig. 1), which was isolated as its methyl ester (Fig. 1) and used for patch testing (2, 3). The aim of this study was to confirm the previous postulate that methyl esterification of the carboxyl group in 15-HPA does not affect the allergenic activity. PMID:17577378

  16. The Spanish standard patch test series: 2016 update by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC).

    PubMed

    Hervella-Garcés, M; García-Gavín, J; Silvestre-Salvador, J F

    2016-09-01

    The Spanish standard patch test series, as recommended by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC), has been updated for 2016. The new series replaces the 2012 version and contains the minimum set of allergens recommended for routine investigation of contact allergy in Spain from 2016 onwards. Four haptens -clioquinol, thimerosal, mercury, and primin- have been eliminated owing to a low frequency of relevant allergic reactions, while 3 new allergens -methylisothiazolinone, diazolidinyl urea, and imidazolidinyl urea- have been added. GEIDAC has also modified the recommended aqueous solution concentrations for the 2 classic, major haptens methylchloroisothiazolinone and methylisothiazolinone, which are now to be tested at 200ppm in aqueous solution, and formaldehyde, which is now to be tested in a 2% aqueous solution. Updating the Spanish standard series is one of the functions of GEIDAC, which is responsible for ensuring that the standard series is suited to the country's epidemiological profile and pattern of contact sensitization. PMID:27262363

  17. Skin Irritation to Glass Wool or Continuous Glass Filaments as Observed by a Patch Test among Human Japanese Volunteers

    PubMed Central

    TSUNODA, Masashi; KIDO, Takamasa; MOGI, Sachiyo; SUGIURA, Yumiko; MIYAJIMA, Eriko; KUDO, Yuichiro; KUMAZAWA, Tatenao; AIZAWA, Yoshiharu

    2014-01-01

    Glass wool and continuous glass filaments have been used in industry. We examined the irritability of those among Japanese. A patch test was performed on 43 volunteers for the followings: glass wool for non-residential use with and without a urea-modified phenolic resin binder, that for residential use with and without the binder, and continuous glass filaments with diameters of 4, 7, 9, and 13 µm. Materials were applied to an upper arm of each volunteer for 24 h. The skin was observed at 1 and 24 h after the removal. At 1 h after removal, slight erythema was observed on the skin of a woman after the exposure to glass wool for residential use without the binder. Erythema was observed on the skin of another woman at 1 h after a 24-h exposure to glass wool for non-residential use without the binder. There were no reactions at 24 h after the removal. The low reactions in the patch test suggested that the irritability caused by glass wool, irrespective of a resin component, could be induced mechanically, and that the irritability caused by continuous glass filaments with resin could be slight and either mechanical or chemical. PMID:25070402

  18. Results of tests of K5NA and a revised formulation of EPDM/cork patch material in MSFC Hot Gas Facility

    NASA Technical Reports Server (NTRS)

    Dean, W. G.

    1982-01-01

    During prelaunch procedures at Kennedy Space Center some of the EPDM Thermal Protection System material was damaged on the Solid Rocket Booster stiffener stubs. The preferred solution was to patch the damaged areas with a cork-filled epoxy patching compound. Before this was done, however, it was requested that this patching technique be checked out by testing it in the MSFC Hot Gas Facility. Two tests were run in the HFG in 1980. The results showed the patch material to be adequate. Since that time, the formulation of the cork-filled epoxy material has been changed. It became necessary to retest this concept to be sure that the new material is as good as or better than the original material. In addition to the revised formulation material, tests were also made using K5NA as the patch material. The objectives of the tests reported herein were to: (1) compare the thermal performance of the original and the new cork-filled epoxy formulations, and (2) compare the K5NA closeout material to these epoxy materials. Material specifications are also discussed.

  19. Patch Testing with Main Sensitizers Does Not Detect All Cases of Contact Allergy to Oxidized Lavender Oil.

    PubMed

    Hagvall, Lina; Christensson, Johanna Bråred

    2016-06-15

    Lavender oil is an essential oil obtained from lavender (Lavendula angustifolia). The main components linalool and linalyl acetate have been shown to autoxidize in contact with oxygen in the air, forming sensitizing hydroperoxides. Patients with suspected allergic contact dermatitis were consecutively patch-tested with oxidized lavender oil 6% pet., oxidized linalyl acetate 6% pet., and oxidized linalool 6% pet. to investigate the frequency of contact allergy to oxidized lavender oil, and the pattern of concomitant reactions to oxidized linalool and oxidized linalyl acetate. Positive reactions to oxidized lavender oil were found in 2.8% of the patients. Among those, 56% reacted to oxidized linalool and/or oxidized linalyl acetate, while 52% reacted to the fragrance markers of the baseline series. Oxidized lavender oil showed among the highest frequencies of contact allergy to studied essential oils. A well-standardized preparation of oxidized lavender oil could be a useful tool for diagnosis of contact allergy to fragrances. PMID:26671837

  20. Children with Atopic Dermatitis Should Always be Patch-tested if They Have Hand or Foot Dermatitis.

    PubMed

    Isaksson, Marléne; Olhardt, Sanna; Rådehed, Jeanette; Svensson, Åke

    2015-05-01

    Atopic dermatitis is the most common chronic inflammatory disease among children in industrialised countries. Many factors influence this disease in a negative way and contact allergy is one such factor. The aim of the study was to examine the frequency of contact allergy among children with the diagnosis atopic dermatitis. Contact allergy was found in 22/82 children (26.8%), the most common from Amerchol L101 (11.0%), potassium dichromate (7.3%), and nickel sulfate (4.9%). A statistically significant difference in contact allergy frequency was demonstrated for those with hand and/or foot eczema compared to those without. Children with atopic dermatitis who suffer from hand and/or foot dermatitis should always be patch-tested to evaluate whether they have a relevant contact allergy and thus allergic contact dermatitis. PMID:25367826

  1. Con-Patch: When a Patch Meets Its Context.

    PubMed

    Romano, Yaniv; Elad, Michael

    2016-09-01

    Measuring the similarity between the patches in images is a fundamental building block in various tasks. Naturally, the patch size has a major impact on the matching quality and on the consequent application performance. Under the assumption that our patch database is sufficiently sampled, using large patches (e.g., 21 × 21 ) should be preferred over small ones (e.g., 7 × 7 ). However, this dense-sampling assumption is rarely true; in most cases, large patches cannot find relevant nearby examples. This phenomenon is a consequence of the curse of dimensionality, stating that the database size should grow exponentially with the patch size to ensure proper matches. This explains the favored choice of small patch size in most applications. Is there a way to keep the simplicity and work with small patches while getting some of the benefits that large patches provide? In this paper, we offer such an approach. We propose to concatenate the regular content of a conventional (small) patch with a compact representation of its (large) surroundings-its context. Therefore, with a minor increase of the dimensions (e.g., with additional ten values to the patch representation), we implicitly/softly describe the information of a large patch. The additional descriptors are computed based on a self-similarity behavior of the patch surrounding. We show that this approach achieves better matches, compared with the use of conventional-size patches, without the need to increase the database-size. Also, the effectiveness of the proposed method is tested on three distinct problems: 1) external natural image denoising; 2) depth image super-resolution; and 3) motion-compensated frame-rate up conversion. PMID:27295669

  2. Con-Patch: When a Patch Meets Its Context

    NASA Astrophysics Data System (ADS)

    Romano, Yaniv; Elad, Michael

    2016-09-01

    Measuring the similarity between patches in images is a fundamental building block in various tasks. Naturally, the patch-size has a major impact on the matching quality, and on the consequent application performance. Under the assumption that our patch database is sufficiently sampled, using large patches (e.g. 21-by-21) should be preferred over small ones (e.g. 7-by-7). However, this "dense-sampling" assumption is rarely true; in most cases large patches cannot find relevant nearby examples. This phenomenon is a consequence of the curse of dimensionality, stating that the database-size should grow exponentially with the patch-size to ensure proper matches. This explains the favored choice of small patch-size in most applications. Is there a way to keep the simplicity and work with small patches while getting some of the benefits that large patches provide? In this work we offer such an approach. We propose to concatenate the regular content of a conventional (small) patch with a compact representation of its (large) surroundings - its context. Therefore, with a minor increase of the dimensions (e.g. with additional 10 values to the patch representation), we implicitly/softly describe the information of a large patch. The additional descriptors are computed based on a self-similarity behavior of the patch surrounding. We show that this approach achieves better matches, compared to the use of conventional-size patches, without the need to increase the database-size. Also, the effectiveness of the proposed method is tested on three distinct problems: (i) External natural image denoising, (ii) Depth image super-resolution, and (iii) Motion-compensated frame-rate up-conversion.

  3. An experimental test of the effects of food resources and hydraulic refuge on patch colonization by stream macroinvertebrates during spates.

    PubMed

    Negishi, Junjiro N; Richardson, John S

    2006-01-01

    1. The passive or active movement of organisms between habitat patches plays important roles in achieving ecosystem resilience to disturbance and long-term control of population levels. However, causal mechanisms of disturbance-induced movements of mobile biota across heterogeneous habitat patches at a relatively short time-scale are little understood. 2. We experimentally tested the effects of food resource values on macroinvertebrate colonization of hydraulic refugia from spates in a second-order creek. Experimental cages were colonized by macroinvertebrates with combinations of resource types (natural or polyester leaves), and extent of exposure to stream flow (exposed to or sheltered from current); one half of each set was collected before and after a spate. This experiment was repeated over three spates of varying magnitude and seasonal contexts. 3. Pre-spate colonization was consistently greater for the cages with natural leaves relative to artificial leaves regardless of the extent of flow exposure. Two autumn spates with relatively low and stable antecedent flow conditions caused large movements of organic matter and macroinvertebrates across the stream, showing community-level accumulations into hydraulically sheltered patches independent of food treatment. The smallest spate with high and variable antecedent flows during winter resulted in negligible responses, which we interpret to be a result of depletion of easily transportable organic matter and organisms. 4. Two detritivorous taxa, the mayfly Paraleptophlebia spp. and stonefly Despaxia augusta (Banks) were the most responsive to autumn spates, and had disproportionately higher colonization rates of cages when provided with natural leaves during the largest autumn spate. Preferential settlement in food-enriched hydraulic refugia was attributable to taxon-specific mobility related to efficient acquisition of detritus resource, whose availability varies spatially and temporally. 5. Our findings suggest

  4. Discrepancy in patch test results with wool wax alcohols and Amerchol L-101.

    PubMed

    Matthieu, L; Dockx, P

    1997-03-01

    Wondering why Amerchol L-101 (containing wool wax alcohols obtained from the hydrolysis of wool fat) appears as a test material (100%) in a cosmetics series (Chemotechnique Diagnostics AB), as wool wax alcohols were already tested in the European standard series, we added Amerchol L-101 (100%) systematically to the standard series. From 8 April 1991 to 28 February 1992, a total of 393 patients were tested: 3.05% (n = 12) showed positive test results (+, +2, +3) for wool wax alcohols as well as Amerchol L-101 (100%), 0.3% (n = 1) for wool wax alcohols only, and 11.1% (n = 44) for Amerchol L-101 (100%) only. Thus, the positive tests for Amerchol L-101 (100%) had a higher frequency of 3.4 compared to those for wool wax alcohols. In the meantime, we also added Amerchol L-101 50% (Trolab) to the standard series. Of all patients tested (n = 223) 2.7% (n = 6) had positive reactions to wool wax alcohols and 12.1% (n = 27) to Amerchol L-101 100% and/or 50%. Thus, positive reactions to Amerchol L-101 (100% and 50%) were 4.5 higher, whereas the rate of concordancy decreased. It is remarkable that 8 patients only had a positive reaction to Amerchol L-101 50% and 9 only to Amerchol L-101 100%. It seems that we miss many diagnoses in contact allergy by using only the standard wool wax alcohols test (30%). PMID:9145265

  5. Patch test results in children and adolescents. Study from the Santa Casa de Belo Horizonte Dermatology Clinic, Brazil, from 2003 to 2010*

    PubMed Central

    Rodrigues, Dulcilea Ferraz; Goulart, Eugênio Marcos Andrade

    2015-01-01

    BACKGROUND Patch testing is an efficient method to identify the allergen responsible for allergic contact dermatitis. OBJECTIVE To evaluate the results of patch tests in children and adolescents comparing these two age groups' results. METHODS Cross-sectional study to assess patch test results of 125 children and adolescents aged 1-19 years, with suspected allergic contact dermatitis, in a dermatology clinic in Brazil. Two Brazilian standardized series were used. RESULTS Seventy four (59.2%) patients had "at least one positive reaction" to the patch test. Among these positive tests, 77.0% were deemed relevant. The most frequent allergens were nickel (36.8%), thimerosal (18.4%), tosylamide formaldehyde resin (6.8%), neomycin (6.4%), cobalt (4.0%) and fragrance mix I (4.0%). The most frequent positive tests came from adolescents (p=0.0014) and females (p=0.0002). There was no relevant statistical difference concerning contact sensitizations among patients with or without atopic history. However, there were significant differences regarding sensitization to nickel (p=0.029) and thimerosal (p=0.042) between the two age groups under study, while adolescents were the most affected. CONCLUSION Nickel and fragrances were the only positive (and relevant) allergens in children. Nickel and tosylamide formaldehyde resin were the most frequent and relevant allergens among adolescents. PMID:26560213

  6. Use of the cytosensor microphysiometer to predict results of a 21-day cumulative irritation patch test in humans.

    PubMed

    Landin, Wendell E; Mun, Greg C; Nims, Raymond W; Harbell, John W

    2007-09-01

    The cytosensor microphysiometer (mu phi) was investigated as a rapid, relatively inexpensive test to predict performance of skin cleansing wipes on the human 21-day cumulative irritation patch test (21CIPT). It indirectly measures metabolic rate changes in L929 cells as a function of test article dose, by measuring the acidification rate in a low-buffer medium. The dose producing a 50% reduction in metabolic rate (MRD50), relative to the baseline rate, is used as a measure of toxicity. The acute toxicity of the mu phi assay can be compared to the chronic toxicity of the 21CIPT, which is based largely on the exposure of test agents to the epidermal cells, resulting in damage and penetration of the stratum corneum leading to cell toxicity. Two series of surfactant-based cleansing wipe products were tested via the mu phi assay and 21CIPT. The first series, consisting of 20 products, was used to determine a prediction model. The second series of 38 products consisted of routine product development formulas or marketed products. Comparing the results from both tests, samples with an MRD50 greater than 50 mg/ml provided a 21CIPT score consistent with a product that performs satisfactorily in the market. When the MRD50 was greater than 78 mg/ml, the 21CIPT score was usually zero. The mu phi may be more sensitive than the 21CIPT for ranking minimally irritating materials. The mu phi assay is useful as a screen for predicting the performance of a wet wipes formula on the 21CIPT, and concurrently reduces the use of animals for safety testing in a product development program for cleansing wipes. PMID:17475442

  7. Adult 4-H Volunteer Empowerment in 4-H Youth Development Settings

    ERIC Educational Resources Information Center

    Olsen, Pamela

    2009-01-01

    The primary purpose of this study was to determine which factors related to adult 4-H volunteer empowerment in 4-H youth development settings. This study examined the relationship of adult 4-H volunteers' perceived leadership styles of Oregon 4-H Youth Development Educators (YDE) to the adult 4-H volunteer sense of empowerment. In addition,…

  8. Strengthening 4-H by Analyzing Enrollment Data

    ERIC Educational Resources Information Center

    Hamilton, Stephen F.; Northern, Angela; Neff, Robert

    2014-01-01

    The study reported here used data from the ACCESS 4-H Enrollment System to gain insight into strengthening New York State's 4-H programming. Member enrollment lists from 2009 to 2012 were analyzed using Microsoft Excel to determine trends and dropout rates. The descriptive data indicate declining 4-H enrollment in recent years and peak…

  9. Engaging Library Partners in 4-H Programming

    ERIC Educational Resources Information Center

    Fields, Nia Imani; Rafferty, Elizabeth

    2012-01-01

    When most people think about 4-H, they remember county fairs, livestock programs, and agricultural education. While these programs are still prominent, 4-H has grown in order to meet the growing demands of today's youth. The organization has expanded services and programs to serve rural, suburban, and urban youth in every state in the U.S. 4-H is…

  10. Application of Near-Field Microwave and Millimeter Wave Nondestructive Testing for Evaluation of Fiber Breakage and Orientation Evaluation in CFRP Composite Patches

    NASA Astrophysics Data System (ADS)

    Kharkovsky, S.; Zoughi, R.

    2005-04-01

    Near-field microwave and millimeter wave nondestructive testing and evaluation techniques have been successfully used for detecting defects such as disbond and delamination in complex composite structures. This paper presents the results of fiber breakage detection and fiber orientation determination in carbon fiber reinforced polymer patches which are used in aerospace industry and civil infrastructure.

  11. The role of patch testing in the evaluation of orthopedic implant-related adverse effects: current evidence does not support broad use.

    PubMed

    Crawford, Glen H

    2013-01-01

    In recent years, there has been a growing interest in the use of skin patch testing to evaluate patients for orthopedic, implant-related adverse effects. This may be done preoperatively to avoid implanting a material to which an individual may be allergic or postoperatively to implicate sensitivity as a cause for implant failure. There is emerging evidence that patch testing might have utility in the workup of implant-related adverse events; however, the level of evidence at the present time is weak and based only on a collection of case reports, series, and retrospective cohort studies (level IV evidence as per United States Department of Health and Human Services guidelines); there are no randomized controlled trials (level I evidence) with which to guide medical decision making. Recent reports have advocated that patch testing be broadly used in the preoperative evaluation of all patients self-reporting a history of metal sensitivity. In addition, several authors have advocated that patch test results should guide preoperative implant selection and postoperative implant removal. It is the opinion of this author that these recommendations are premature, lacking robust clinical evidence, and unfeasible given the broad-reaching logistical impact and societal costs involved. More robust clinical data are needed, and thorough cost-benefit analyses must be performed before such far-reaching and costly systematic practices should be broadly implemented. PMID:23665834

  12. Allergic contact stomatitis to dodecyl gallate? A review of the relevance of positive patch test results to gallates.

    PubMed

    Gamboni, Sarah E; Palmer, Amanda M; Nixon, Rosemary L

    2013-08-01

    Gallic acid esters or gallates are antioxidants used as preservatives in food and cosmetics. Few cases of gallates causing allergic contact dermatitis (ACD) have been reported in the literature. We present a case report of a 42-year-old beauty therapist who presented with a swollen tongue. Patch testing was positive to dodecyl gallate, commonly reported as being present in edible oil and oily foods such as margarine. Our patient avoided foods presumed to contain gallates and at the 6-week review reported a substantial improvement in her tongue symptoms. We reviewed our database and found 16 (7%) definitely or possibly relevant reactions to dodecyl gallate, seven (15%) definitely or possibly relevant reactions to propyl gallate and six (3%) definitely or possibly relevant reactions to octyl gallate. Most reactions were attributed to margarine, moisturising cream and lipstick. These products are often mentioned in the literature as containing gallates; however, ingredient labelling and discussions with manufacturers made it difficult to establish whether they are currently present in foods. Ascertaining relevance for these reactions is not always possible. PMID:22943875

  13. Linac4 H- ion sources

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Aguglia, D.; Alessi, J.; Andersson, P.; Bertolo, S.; Briefi, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; David, N.; Chaudet, E.; Faircloth, D.; Fantz, U.; Fink, D. A.; Garlasche, M.; Grudiev, A.; Guida, R.; Hansen, J.; Haase, M.; Hatayama, A.; Jones, A.; Koszar, I.; Lallement, J.-B.; Lombardi, A. M.; Machado, C.; Mastrostefano, C.; Mathot, S.; Mattei, S.; Moyret, P.; Nisbet, D.; Nishida, K.; O'Neil, M.; Paoluzzi, M.; Scrivens, R.; Shibata, T.; Steyaert, D.; Thaus, N.; Voulgarakis, G.

    2016-02-01

    CERN's 160 MeV H- linear accelerator (Linac4) is a key constituent of the injector chain upgrade of the Large Hadron Collider that is being installed and commissioned. A cesiated surface ion source prototype is being tested and has delivered a beam intensity of 45 mA within an emittance of 0.3 π ṡ mm ṡ mrad. The optimum ratio of the co-extracted electron- to ion-current is below 1 and the best production efficiency, defined as the ratio of the beam current to the 2 MHz RF-power transmitted to the plasma, reached 1.1 mA/kW. The H- source prototype and the first tests of the new ion source optics, electron-dump, and front end developed to minimize the beam emittance are presented. A temperature regulated magnetron H- source developed by the Brookhaven National Laboratory was built at CERN. The first tests of the magnetron operated at 0.8 Hz repetition rate are described.

  14. Pretreatment of the test area with 1-day occlusion improves the response rate to NiSO4 5% pet. patch tests in subjects with a positive history of nickel allergy.

    PubMed

    Seidenari, S; Manzini, B M; Belletti, B

    1995-09-01

    A group of 58 women, aged 18 to 51 years, with a clinical history of nickel allergy, who exhibited equivocal or negative reactions to nickel sulfate 5% pet. patch tests performed on the skin of the back, were recruited consecutively from the patch test clinic from September 1993 to June 1994. In order to improve the response rate to NiSO4 5% pet. patch tests, a testing procedure utilizing pretreatment of the test area by 1-day (24-h) occlusion was introduced. Patients underwent 2 patch tests on adjacent sites of the volar surface of both forearms. 3 of the patch tests were performed with 40 mg nickel sulfate 5% pet., whereas a control test was carried out by occluding with an empty chamber. 2 of the nickel sulfate test sites were pretreated with 1-day occlusion performed with an empty chamber. A visual grading system and echographic measurement were used to quantify the responses 30-40 min after patch test removal. Echographic evaluations were carried out using a 20 MHz B-scanner. Measurement of skin thickness and determination of the hypoechogenic dermal area, both considered to be parameters of inflammation, were used to evaluate the intensity of the allergic reaction. At the 3-day (72-h) evaluation, 19 subjects out of 58 clearly showed positive reactions to nickel sulfate 5% pet. at pre-occluded skin sites. Moreover, values of skin thickness and of 0-30 areas at positive pre-occluded nickel test areas were higher in respect to control test areas, confirming clinical evidence of increased response to NiSO4 after occlusion. PMID:8565454

  15. Community Development: A 4-H Intern Report.

    ERIC Educational Resources Information Center

    Scheneman, C. Stephen

    State progress reports on the 4-H/Community Development program, a 1973 nationwide Federally sponsored program facilitating youth in community decision-making processes, indicate that the program appears to be evolving into a viable and integral part of the total 4-H program. Although the report describes unique program features of various States,…

  16. Holding on to 4-H Leaders.

    ERIC Educational Resources Information Center

    Hass, Glen

    1979-01-01

    Data from a survey of 4-H Club leaders in Saskatchewan, Canada, were used to determine the effect of attendance at leadership training events on leaders' decisions to re-enroll or discontinue. It was found that involvement in 4-H activities, supported by leadership training, increased leaders' satisfaction and likelihood of re-enrolling. (MF)

  17. Strengthening 4-H Program Communication through Technology

    ERIC Educational Resources Information Center

    Robideau, Kari; Santl, Karyn

    2011-01-01

    Advances in technology are transforming how youth and parents interact with programs. The Strengthening 4-H Communication through Technology project was implemented in eight county 4-H programs in Northwest Minnesota. This article outlines the intentional process used to effectively implement technology in program planning. The project includes:…

  18. Granisetron Transdermal Patch

    MedlinePlus

    ... patch. Each patch is stuck onto a thin plastic liner and a separate rigid plastic film. Do not open the pouch in advance, ... cut the patch into pieces. Peel the thin plastic liner off of the printed side of the ...

  19. Methylphenidate Transdermal Patch

    MedlinePlus

    ... still remove the patch at your regular patch removal time. Do not apply extra patches to make ... room temperature and away from excess heat and moisture (not in the bathroom). Do not refrigerate or ...

  20. Rivastigmine Transdermal Patch

    MedlinePlus

    ... still remove the patch at your regular patch removal time. If it is almost time for the ... room temperature and away from excess heat and moisture (not in the bathroom). Throw away any patches ...

  1. Cabbage Patch

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This Sojourner rover image of the Cabbage Patch shows small rounded objects on the surface that are about 3-4 cm across. Some of these are within excavations, which are about 0.5 cm wide. Several questions arise about the pebbles: Why are they rounded? Where did they come from? What do they mean?

    Geologists use MULTIPLE WORKING HYPOTHESES when attempting to explain observations. Some hypotheses that could account for the pebbles are: They were rounded during transport by waters of catastrophic floods and deposited on the Ares Vallis floodplain They were rounded by wave action on an ancient Martian beach They were rounded during glacial transport They are glasses that were produced by melting during impact cratering. The glass was first ejected from the crater, then molded into spherical shapes or drops as it traveled through the atmosphere, and finally was deposited at the sites They are spatter from lava flows They are nodules brought up from the deep Martian interior by lava flows or pyroclastic eruptions. They are concretions formed in sedimentary rocks They came from ancient conglomerate rocks. The pebbles were rounded by water action and subsequently lithified into conglomerate rocks. Later, the waters of catastrophic floods transported the conglomerates and deposited them on the Ares floodplain. The pebbles were then freed from the rocks by weathering. A combination of the above

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  2. Relationships between 4-H Volunteer Leader Competencies and Skills Youth Learn in 4-H Programs

    ERIC Educational Resources Information Center

    Radhakrishna, Rama; Ewing, John C.

    2011-01-01

    This article examined the relationships between 4-H volunteer leader competencies and skills youth learn in 4-H. Using a descriptive-correlational research, the study reported found significant relationships between leadership competencies and skills youth learn in 4-H. Regression analysis revealed that two variables--skills and…

  3. Middle Childhood: 4-H Child Development Project.

    ERIC Educational Resources Information Center

    Francis, Connie M.

    Part of a series for 4-H members between 9 and 19 years of age, this age-graded guide to the development of 6-, 7-, and 8-year-olds aims to help 4-H members who are children and adolescents themselves: (1) understand the physical, mental, social, and emotional development of children in middle childhood; (2) learn to care for a child in middle…

  4. Granisetron Transdermal Patch

    MedlinePlus

    ... the patch. Each patch is stuck onto a thin plastic liner and a separate rigid plastic film. Do not open the pouch in advance, because ... to cut the patch into pieces. Peel the thin plastic liner off of the printed side ... one piece of the plastic film from the sticky side of the patch. Be ...

  5. Demonstration of an instrumented patch

    NASA Astrophysics Data System (ADS)

    Martinez, M.; Renaud, G.; Backman, D.; Genest, M.; Delannoy, M.

    2007-04-01

    The primary objective of this study was to demonstrate the effectiveness of various strain measurement techniques at detecting the disbonding of a composite repair patch and then using this information to validate a new capacitance based disbond detection technique. The instrumented repair patch was parametrically designed with the help of Finite Element Analysis (FEA) software to have a stress concentration at its tip. This stress concentration was designed to produce a disbond during fatigue testing, without the need for the introduction of any foreign material to create an artificial disbond condition. The aluminum substrate was grit blasted and the instrumented patch was bonded using FM ®73 adhesive, and was cured following the recommendations of the manufacturer. The geometric characteristics of the patch followed standard repair guidelines for such variables as material selection, taper angles and loading conditions, with the exception of the area designed for premature disbond. All test specimens were inspected using non-destructive testing technique (ultrasound pulse echo) to guarantee that no disbonding had occurred during curing of the specimen. The specimens were placed under fatigue loading to induce a disbond condition between the aluminum substrate and the patch. The specimens were cyclically loaded and strain gauges bonded to strategic locations on the aluminum and composite patch surface to be able to measure changes in surface strains as the disbond progressed. A Digital Image Correlation (DIC) system was also used to measure full field strains over the gauge length of the coupon. The DIC results were compared with the strain gauge data and were used to provide a qualitative measure of the load transfer in the bonded specimen, which clearly demonstrated the change in surface strain that occurred as the composite patch disbonded from the aluminum substrate. Thermoelastic Stress Analysis (TSA) was also used to measure surface strains on the

  6. Patching. Restitching business portfolios in dynamic markets.

    PubMed

    Eisenhardt, K M; Brown, S L

    1999-01-01

    In turbulent markets, businesses and opportunities are constantly falling out of alignment. New technologies and emerging markets create fresh opportunities. Converging markets produce more. And of course, some markets fade. In this landscape of continuous flux, it's more important to build corporate-level strategic processes that enable dynamic repositioning than it is to build any particular defensible position. That's why smart corporate strategists use patching, a process of mapping and remapping business units to create a shifting mix of highly focused, tightly aligned businesses that can respond to changing market opportunities. Patching is not just another name for reorganizing; patchers have a distinctive mindset. Traditional managers see structure as stable; patching managers believe structure is inherently temporary. Traditional managers set corporate strategy first, but patching managers keep the organization focused on the right set of business opportunities and let strategy emerge from individual businesses. Although the focus of patching is flexibility, the process itself follows a pattern. Patching changes are usually small in scale and made frequently. Patching should be done quickly; the emphasis is on getting the patch about right and fixing problems later. Patches should have a test drive before they're formalized but then be tightly scripted after they've been announced. And patching won't work without the right infrastructure: modular business units, fine-grained and complete unit-level metrics, and companywide compensation parity. The authors illustrate how patching works and point out some common stumbling blocks. PMID:10387579

  7. 4-H Science Inquiry Video Series

    ERIC Educational Resources Information Center

    Green, Jeremy W.; Black, Lynette; Willis, Patrick

    2013-01-01

    Studies support science inquiry as a positive method and approach for 4-H professionals and volunteers to use for teaching science-based practices to youth. The development of a science inquiry video series has yielded positive results as it relates to youth development education and science. The video series highlights how to conduct science-rich…

  8. The Preschooler: 4-H Child Development Project.

    ERIC Educational Resources Information Center

    Francis, Connie M.

    Intended for 4-H participants who plan and implement activities in the area of child development, this booklet provides a study guide to help young learners: (1) gain understanding of a preschool child's physical, mental, social, and emotional growth; (2) learn to care for a preschooler and promote preschoolers' feelings of security and safety;…

  9. Separates. 4-H Textile Science Advanced Project.

    ERIC Educational Resources Information Center

    Scholl, Jan F.

    This booklet, which was developed for use by 4-H club members in Pennsylvania, contains the information required to sew a two-piece nontailored outfit and/or a one-or two-piece dress. The following are among the topics covered: the difference between a fiber and a fabric; properties of different fibers and fabrics; common jacket, neckline, sleeve,…

  10. Non-invasive monitoring and quantitative analysis of patch test reactions by reflectance spectrophotometry, laser Doppler flowmetry and transepidermal water loss

    NASA Astrophysics Data System (ADS)

    Eikje, Natalja Skrebova; Arase, Seiji

    2008-02-01

    Reflectance spectrophotometry (RS), laser Doppler flowmetry (LDF) and transepidermal water loss (TEWL) techniques were simultaneously used to non-invasively monitor skin colour (SC), skin blood flow (SBF) and barrier function damage (BFD) in routinely patch-tested Japanese patients in dermatology clinic. The analytical quality, reliability and reproducibility of each technique were compared and analyzed in correlated to visual scoring patch test (PT) reactions as negative (-), doubtful (+?), weak (+) and strong (++/+++) at 48- and 72-hour monitoring. An attempt was made to quantify predominant in the clinic "+?"- and "+'"-PT-reactions. The relationship between 48 h and 72 h measurements in different reaction groups was poor for TEWL, LDF showed a tendency to decrease at 72 h, but good for RS. A correlation between visual scorings and instrumental mean values was poor for TEWL, good for LDF and excellent for RS. So, measurements by RS were the most statistically significant to non-invasively monitor and quantify doubtful, weak and strong PT reactions, accordingly providing continuous data grading of reaction intensity suitable in the clinic. Moreover, monitoring of SC changes was the most reliable parameter for the quantitative distinguishing of doubtful and weak reactions in pigmented skin.

  11. Reliability of a flushing questionnaire and the ethanol patch test in screening for inactive aldehyde dehydrogenase-2 and alcohol-related cancer risk.

    PubMed

    Yokoyama, A; Muramatsu, T; Ohmori, T; Kumagai, Y; Higuchi, S; Ishii, H

    1997-12-01

    Molecular epidemiology of esophageal and upper aerodigestive tract cancers revealed that alcohol is more carcinogenic in persons with inactive aldehyde dehydrogenase-2 (ALDH2) than in those with active ALDH2. A simple questionnaire has been developed to screen for the facial flushing that occurs in persons with inactive ALDH2 when they drink even a single glass of beer. In this study, 266 of 284 consecutive male Japanese clinic patients (age > or = 50 years) completed the flushing questionnaire, and 239 underwent the ethanol patch test (a cutaneous model for the flushing response). Blinded genotyping showed inactive ALDH2 for 94.4% (102 of 108) of subjects who reported always flushing (early in their drinking history or currently) and for 47.7% (21 of 44) of those who reported sometimes flushing, whereas 95.6% (109 of 114) of subjects reporting that they never exhibited facial flushing had active ALDH2. When all three categories of flushing (current always, former always, and sometimes) were collapsed into one, the questionnaire's sensitivity and specificity for identifying inactive ALDH2 were 96.1 and 79.0%, respectively, compared with 72.4 and 71.4% for the ethanol patch test. The results suggest the utility of this simple flushing questionnaire in daily practice, as well as large-scale studies to assess cancer risks associated with drinking and ALDH2 and for activities aimed at preventing alcohol-related cancer. PMID:9419411

  12. National 4-H Common Measures: Initial Evaluation from California 4-H

    ERIC Educational Resources Information Center

    Lewis, Kendra M.; Horrillo, Shannon J.; Widaman, Keith; Worker, Steven M.; Trzesniewski, Kali

    2015-01-01

    Evaluation is a key component to learning about the effectiveness of a program. This article provides descriptive statistics of the newly developed National 4-H Common Measures (science, healthy living, citizenship, and youth development) based on data from 721 California 4-H youth. The measures were evaluated for their reliability and validity of…

  13. Effectiveness of the 4-H Program as Perceived by Parents of 4-H Participants

    ERIC Educational Resources Information Center

    Radhakrishna, Rama; Foley, Caitlin; Ingram, Patreese; Ewing, John C.

    2013-01-01

    The study reported here examined the effectiveness of 4-H program as perceived by parents of program participants. Descriptive-correlational design was employed, with data collected using a mail survey. Parents perceived 4-H as an effective organization in teaching life skills to youth. Significant relationships were found between parents'…

  14. Scopolamine Transdermal Patch

    MedlinePlus

    ... patch from its protective pouch. To expose the adhesive surface of the patch, the clear plastic protective ... peeled off and discarded. Contact with the exposed adhesive layer should be avoided to prevent contamination of ...

  15. Lidocaine Transdermal Patch

    MedlinePlus

    ... that area. Use scissors to remove the outer seal from the package. Then pull apart the zipper seal. Remove up to three patches from the package and press the zipper seal tightly together. The remaining patches may dry out ...

  16. Metal Patch Antenna

    NASA Technical Reports Server (NTRS)

    Chamberlain, Neil F. (Inventor); Hodges, Richard E. (Inventor); Zawadzki, Mark S. (Inventor)

    2012-01-01

    Disclosed herein is a patch antenna comprises a planar conductive patch attached to a ground plane by a support member, and a probe connector in electrical communication with the conductive patch arranged to conduct electromagnetic energy to or from the conductive patch, wherein the conductive patch is disposed essentially parallel to the ground plane and is separated from the ground plane by a spacing distance; wherein the support member comprises a plurality of sides disposed about a central axis oriented perpendicular to the conductive patch and the ground plane; wherein the conductive patch is solely supported above the ground plane by the support member; and wherein the support member provides electrical communication between the planer conductive patch and the ground plane.

  17. VIBRATIONALLY EXCITED C{sub 4}H

    SciTech Connect

    Cooksy, Andrew L.; Gottlieb, C. A.; Thaddeus, P.; Patel, Nimesh A.; Young, Ken H.; McCarthy, M. C.; Killian, T. C.

    2015-02-01

    Rotational spectra in four new excited vibrational levels of the linear carbon chain radical C{sub 4}H were observed in the millimeter band between 69 and 364 GHz in a low pressure glow discharge, and two of these were observed in a supersonic molecular beam between 19 and 38 GHz. All have rotational constants within 0.4% of the X{sup 2}Σ{sup +} ground vibrational state of C{sub 4}H and were assigned to new bending vibrational levels, two each with {sup 2}Σ and {sup 2}Π vibrational symmetry. The new levels are tentatively assigned to the 1ν{sub 6} and 1ν{sub 5} bending vibrational modes (both with {sup 2}Π symmetry), and the 1ν{sub 6}+1ν{sub 7} and 1ν{sub 5}+1ν{sub 6} combination levels ({sup 2}Σ symmetry) on the basis of the derived spectroscopic constants, relative intensities in our discharge source, and published laser spectroscopic and quantum calculations. Prior spectroscopic constants in the 1ν{sub 7} and 2ν{sub 7} levels were refined. Also presented are interferometric maps of the ground state and the 1ν{sub 7} level obtained with the Submillimeter Array (SMA) near 257 GHz which show that C{sub 4}H is present near the central star in IRC+10216. We found no evidence with the SMA for the new vibrationally excited levels of C{sub 4}H at a peak flux density averaged over a 3{sup ′′} synthesized beam of ⩾0.15 Jy/beam in the 294–296 and 304–306 GHz range, but it is anticipated that rotational lines in the new levels might be observed in IRC+10216 when ALMA attains its full design capability.

  18. Learnings and Recommendations to Advance 4-H Science Readiness

    ERIC Educational Resources Information Center

    Schmitt-McQuitty, Lynn; Carlos, Ramona; Smith, Martin H.

    2014-01-01

    The case study investigation reported here assessed California 4-H professionals' understanding of the essential components of effective 4-H Science programming as established by the National 4-H Science Mission Mandate. Using the 4-H Science Checklist as the basis for defining 4-H Science Readiness, academic and program staff were surveyed…

  19. Corridor Length and Patch Colonization by a Butterfly Junonia coenia

    SciTech Connect

    Nick Haddad

    2000-06-01

    Habitat corridors have been proposed to reduce patch isolation and increase population persistence in fragmented landscapes. This study tested whether patch colonization was increased by the presence and various length corridors. The specific butterfly species tested has been shown to use corridors, however, the results indicate that neither the distance between patches or the presence of a corridor influenced colonization.

  20. Noninvasive measuring methods for the investigation of irritant patch test reactions. A study of patients with hand eczema, atopic dermatitis and controls.

    PubMed

    Agner, T

    1992-01-01

    The aim of the study was to assess the susceptibility of clinically normal skin to a standard irritant trauma under varying physiological and patophysiological conditions. Evaluation of skin responses to patch tests with sodium lauryl sulphate (SLS) was used for assessment of skin susceptibility. The following noninvasive measuring methods were used for evaluation of the skin before and after exposure to irritants: measurement of transepidermal water loss by an evaporimeter, measurement of electrical conductance by a hydrometer, measurement of skin blood flow by laser Doppler flowmetry, measurement of skin colour by a colorimeter and measurement of skin thickness by ultrasound A-scan. The studies were carried out on healthy volunteers and patients with eczema. In the first studies the standard irritant patch test for assessment of skin susceptibility was characterized and validated. SLS was chosen among other irritants because of its ability to penetrate and impair the skin barrier. The implications of use of different qualities of SLS was investigated. The applied noninvasive measuring methods were evaluated, and for quantification of SLS-induced skin damage measurement of TEWL was found to be the most sensitive method. Application of the standard test on clinically normal skin under varying physiological and patophysiological conditions lead to the following main results: Seasonal variation in skin susceptibility to SLS was found, with increased susceptibility in winter, when the hydration state of the stratum corneum was also found to be decreased. A variation in skin reactivity to SLS during the menstrual cycle was demonstrated, with an increased skin response at day 1 as compared to days 9-11 in the menstrual cycle. The presence of active eczema distant from the test site increased skin susceptibility to SLS, indicating a generalized hyperreactivity of the skin. Taking these sources of variation into account healthy volunteers and patients with hand eczema and

  1. Minnesota 4-H Science of Agriculture Challenge: Infusing Agricultural Science and Engineering Concepts into 4-H Youth Development

    ERIC Educational Resources Information Center

    Rice, Joshua E.; Rugg, Bradley; Davis, Sharon

    2016-01-01

    Youth involved in 4-H projects have been engaged in science-related endeavors for years. Since 2006, 4-H has invested considerable resources in the advancement of science learning. The new Minnesota 4-H Science of Agriculture Challenge program challenges 4-H youth to work together to identify agriculture-related issues in their communities and to…

  2. Diversity Inclusion in 4-H Youth Programs: Examining the Perceptions among West Virginia 4-H Youth Professionals

    ERIC Educational Resources Information Center

    LaVergne, Douglas D.

    2013-01-01

    The study reported here sought to examine the perceptions of 4-H youth professionals towards diversity inclusion in 4-H youth programs. A majority of professionals positively reported that there are benefits for youth of color and youth with disabilities in 4-H youth programs. Respondents indicated that the lack of information about 4-H youth…

  3. Fentanyl Transdermal Patch

    MedlinePlus

    ... pain, pain after an operation or medical or dental procedure, or pain that can be controlled by medication that is ... transdermal patch.if you are having surgery, including dental surgery, tell the ... to prevent or treat constipation while you are using fentanyl patches.

  4. Visual Display Study: National 4-H Center. A 4-H Intern Report.

    ERIC Educational Resources Information Center

    Farwell, Sanford W.

    An internship report cites ways in which the National 4-H Center could be more effective in a visual sense. The author suggests collecting the memorabilia already at the Center to form an historical museum and coordinating the historical items with present items. Impact areas, those with a lot of traffic, are discussed individually in terms of…

  5. A Survey of Patch Methods

    NASA Technical Reports Server (NTRS)

    Barnhill, R. E.

    1985-01-01

    Patch methods are someshow a response to the fact that surface geometry is local, that is, only small parts of a surface are created at a time. The two categories of patches, transfinite patches and finite dimensional patches are examined and a discussion of trivariate patches is presented.

  6. Nickel-Related Intestinal Mucositis in IBS-Like Patients: Laser Doppler Perfusion Imaging and Oral Mucosa Patch Test in Use.

    PubMed

    Borghini, Raffaele; Puzzono, Marta; Rosato, Edoardo; Di Tola, Marco; Marino, Mariacatia; Greco, Francesca; Picarelli, Antonio

    2016-09-01

    Nickel (Ni) is often the trigger of irritable bowel syndrome (IBS)-like gastrointestinal disorders: its ingestion may cause allergic contact mucositis, identifiable by means of oral mucosa patch test (omPT). OmPT effectiveness has been proven, but it is still an operator-dependent method. Laser Doppler perfusion imaging (LDPI) was tested to support omPT in Ni allergic contact mucositis diagnosis. Group A: 22 patients with intestinal/systemic symptoms related to the ingestion of Ni-containing foods. Group B: 12 asymptomatic volunteers. Ni-related symptoms and their severity were tested by a questionnaire. All patients underwent Ni omPT with clinical evaluation at baseline (T0), after 30 min (T1), after 2 h (T2), and after 24-48 h (T3). LDPI was performed to evaluate the mean mucosal perfusion at T0, T1, and T2. Statistical analysis was performed by ANOVA test and Bonferroni multiple-comparison test. All 22 Ni-sensitive patients (group A) presented oral mucosa hyperemia and/or edema at T2. Eight out of the same 22 patients presented a local delayed vesicular reaction at T3 (group A1), unlike the remaining 14 out of 22 patients (group A2). All 12 patients belonging to control group B did not show any alteration. The mean mucosal perfusion calculated with LDPI showed an increase in both subgroups A1 and A2. In group B, no significant perfusion variations were observed. LDPI may support omPT for diagnostic purposes in Ni allergic contact mucositis. This also applies to symptomatic Ni-sensitive patients without aphthous stomatitis after 24-48 h from omPT and that could risk to miss the diagnosis. PMID:26899317

  7. Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy. Part 2. Patch test relationship to formaldehyde contact allergy, experimental provocation tests, amount of formaldehyde released, and assessment of risk to consumers allergic to formaldehyde.

    PubMed

    de Groot, Anton; White, Ian R; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    This is the second part of an article on formaldehyde-releasers in cosmetics. The patch test relationship between the releasers in cosmetics to formaldehyde contact allergy is reviewed and it is assessed whether products preserved with formaldehyde-releasers may contain enough free formaldehyde to pose a threat to individuals with contact allergy to formaldehyde. There is a clear relationship between positive patch test reactions to formaldehyde-releasers and formaldehyde contact allergy: 15% of all reactions to 2-bromo-2-nitropropane-1,3-diol and 40-60% of the reactions to the other releasers are caused by a reaction to the formaldehyde in the test material. There is only fragmented data on the amount of free formaldehyde in cosmetics preserved with formaldehyde donors. However, all releasers (with the exception of 2-bromo-2-nitropropane-1,3-diol, for which adequate data are lacking) can, in the right circumstances of concentration and product composition, release >200 p.p.m. formaldehyde, which may result in allergic contact dermatitis. Whether this is actually the case in any particular product cannot be determined from the ingredient labelling. Therefore, we recommend advising patients allergic to formaldehyde to avoid leave-on cosmetics preserved with quaternium-15, diazolidinyl urea, DMDM hydantoin, or imidazolidinyl urea, acknowledging that many would tolerate some products. PMID:20136876

  8. Atopy patch tests are useful to predict oral tolerance in children with gastrointestinal symptoms related to non-IgE-mediated cow's milk allergy.

    PubMed

    Nocerino, R; Granata, V; Di Costanzo, M; Pezzella, V; Leone, L; Passariello, A; Terrin, G; Troncone, R; Berni Canani, R

    2013-02-01

    Atopy patch tests (APTs) have been proposed for the diagnostic approach in children with non-IgE-mediated cow's milk allergy and gastrointestinal symptoms. We aimed to investigate the benefit of APTs in predicting oral tolerance in these patients. We prospectively evaluated 172 subjects with a sure diagnosis of non-IgE-mediated CMA and gastrointestinal symptoms (97 boys, 56.4%; age, 6.37 m; range, 2-12 m). At diagnosis, 113/172 (65.7%) children had positive APTs to cow's milk proteins (CMP). After 12 months of exclusion, diet APTs were repeated immediately before OFC. APTs significantly correlated (P < 0.001) with the OFC outcome (r 0.579). Diagnostic accuracy was sensitivity of 67.95%, specificity of 88.3%, PPV of 82.81%, NPV of 76.85%, and a +LR of 5.80. APTs are a valuable tool in the follow-up of children with non-IgE-mediated CMA-related gastrointestinal symptoms by contributing in determining whether an OFC can safely be undertaken. PMID:23205566

  9. The Big E (Energy). 4-H Energy Project. 4-H Member's E-Book, Unit 1.

    ERIC Educational Resources Information Center

    Caldwell, William; And Others

    This activity and record book is designed for unit 1 (ages 9-11) of the Nebraska 4-H Energy Project. In this project, members are required to: (1) use energy wisely by closing doors and turning off lights; (2) inspecting homes for energy use at least once; (3) judging the best use of lighting in a home; (4) sharing ideas about energy use in a…

  10. CPR: Purposeful Action. Putting New Life into 4-H.

    ERIC Educational Resources Information Center

    Jones, Deborah A.; Smith, William C.

    1988-01-01

    In Ohio, 4-H professionals found that it is necessary to conduct market research to have an effective program. Cardiopulmonary resuscitation (CPR) training has been successful in strengthening the 4-H position in the marketplace. (JOW)

  11. Hamsters?! What Does 4-H Stand for, Anyway?

    ERIC Educational Resources Information Center

    Grundeen, Brenda

    This paper briefly traces the history of 4-H youth development programs, explains what youth development is, and shows how the experiential learning model is used in 4-H. Begun over 75 years ago as a means of extending the learning of the land-grant university to rural youth, 4-H is part of the Cooperative Extension Service. The curriculum…

  12. Using Digital Classrooms to Conduct 4-H Club Meetings

    ERIC Educational Resources Information Center

    West, Patricia; Fuhrman, Nicholas E.; Morgan, A. Christian; Duncan, Dennis W.

    2012-01-01

    Using computer technology and digital classrooms to conduct 4-H Club meetings is an efficient way to continue delivering quality 4-H programming during times of limited resources and staff. Nineteen Junior and Senior 4-H'ers participated in seven digital classroom workshops using the Wimba Classroom application. These digital classroom…

  13. Factors Affecting Teen Involvement in Pennsylvania 4-H Programming

    ERIC Educational Resources Information Center

    Gill, Bart E.; Ewing, John C.; Bruce, Jacklyn A.

    2010-01-01

    The study reported here determined the factors that affect teen involvement in 4-H programming. The design of the study was descriptive and correlational in nature. Using a purposive sampling procedure, a survey questionnaire was distributed to all (N=214) 4-H members attending the 4-H State Leadership Conference. The major findings of the study…

  14. The 4-H Club Meeting: An Essential Youth Development Strategy

    ERIC Educational Resources Information Center

    Cassels, Alicia; Post, Liz; Nestor, Patrick I.

    2015-01-01

    The club meeting has served as a key delivery method for 4-H programming across the United States throughout its history. A survey of WV 4-H community club members reinforces the body of evidence that the 4-H club meeting is an effective vehicle for delivering positive youth learning opportunities within the umbrella of the Essential Elements of…

  15. Nicotine Transdermal Patch

    MedlinePlus

    ... patches are used to help people stop smoking cigarettes. They provide a source of nicotine that reduces ... cause harm to the fetus.do not smoke cigarettes or use other nicotine products while using nicotine ...

  16. Diclofenac Transdermal Patch

    MedlinePlus

    ... and making sure not to cut the zipper seal just below it. Pull apart the zipper seal on the envelope and remove one patch. Reseal the envelope by squeezing the zipper seal together. Make sure the envelope is closed tightly ...

  17. Lidocaine Transdermal Patch

    MedlinePlus

    ... patches are used to relieve the pain of post-herpetic neuralgia (PHN; the burning, stabbing pains, or ... in your eye, wash it with plenty of water or saline solution. Wash your hands after handling ...

  18. Rotigotine Transdermal Patch

    MedlinePlus

    ... that causes difficulties with movement, muscle control, and balance) including shaking of parts of the body, stiffness, slowed movements, and problems with balance. Rotigotine transdermal patches are also used to treat ...

  19. Methylphenidate Transdermal Patch

    MedlinePlus

    ... for ADHD, which may include counseling and special education. Make sure to follow all of your doctor's ... that was covered by the patch seizures motion tics or verbal tics believing things that are not ...

  20. DyninstAPI Patches

    2012-04-01

    We are seeking a code review of patches against DyninstAPI 8.0. DyninstAPI is an open source binary instrumentation library from the University of Wisconsin and University of Maryland. Our patches port DyninstAPI to the BlueGene/P and BlueGene/Q systems, as well as fix DyninstAPI bugs and implement minor new features in DyninstAPI.

  1. FNAL system patching design

    SciTech Connect

    Schmidt, Jack; Lilianstrom, Al; Romero, Andy; Dawson, Troy; Sieh, Connie; /Fermilab

    2004-01-01

    FNAL has over 5000 PCs running either Linux or Windows software. Protecting these systems efficiently against the latest vulnerabilities that arise has prompted FNAL to take a more central approach to patching systems. Due to different levels of existing support infrastructures, the patching solution for linux systems differs from that of windows systems. In either case, systems are checked for vulnerabilities by Computer Security using the Nessus tool.

  2. Tunable circular patch antennas

    NASA Astrophysics Data System (ADS)

    Lan, G.-L.; Sengupta, D. L.

    1985-10-01

    A method to control the resonant or operating frequencies of circular patch antennas has been investigated experimentally and theoretically. It consists of the placement of passive metallic or tuning posts at approximate locations within the input region of the antenna. Comparison of measured and analytical results seems to establish the validity of a theoretical model proposed to determine the input performance of such circular patch antennas.

  3. Frequent occurrence of T cell–mediated late reactions revealed by atopy patch testing with hypoallergenic rBet v 1 fragments

    PubMed Central

    Campana, Raffaela; Moritz, Katharina; Marth, Katharina; Neubauer, Angela; Huber, Hans; Henning, Rainer; Blatt, Katharina; Hoermann, Gregor; Brodie, Tess M.; Kaider, Alexandra; Valent, Peter; Sallusto, Federica; Wöhrl, Stefan; Valenta, Rudolf

    2015-01-01

    Background Late allergic reactions are common in the course of allergen-specific immunotherapy and even occur with allergy vaccines with reduced IgE reactivity. Objective We sought to study atopy patch test (APT) reactions and T-cell responses to the recombinant birch pollen allergen Bet v 1 and recombinant hypoallergenic T-cell epitope–containing Bet v 1 fragments in patients with birch pollen allergy with and without atopic dermatitis (AD). Methods A clinical study was conducted in 15 patients with birch pollen allergy with AD (group 1), 5 patients with birch pollen allergy without AD (group 2), 5 allergic patients without birch pollen allergy (group 3), and 5 nonallergic subjects (group 4) by performing skin prick tests and APTs with rBet v 1 and hypoallergenic rBet v 1 fragments. T-cell, cutaneous lymphocyte antigen (CLA)+ and CCR4+ T-cell and cytokine responses were studied by thymidine uptake, carboxyfluorescein diacetate succinimidyl ester staining, and Luminex technology, respectively. Results rBet v 1 and hypoallergenic rBet v 1 fragments induced APT reactions in not only most of the patients with birch pollen allergy with AD (11/15) but also in most of those without AD (4/5). Patients with birch pollen allergy with AD had higher Bet v 1–specific proliferation of CLA+ and CCR4+ T cells compared with patients with birch pollen allergy without AD. There were no differences in Bet v 1–specific CLA+ and CCR4+ proliferation and cytokine secretion in patients with and without APT reactions. Conclusion Hypoallergenic rBet v 1 fragments induce T cell–dependent late reactions not only in patients with birch pollen allergy with AD but also in those without AD, which can be determined based on APT results but not based on in vitro parameters. PMID:26518092

  4. Development and evaluation of a tampering resistant transdermal fentanyl patch.

    PubMed

    Cai, Bing; Engqvist, Håkan; Bredenberg, Susanne

    2015-07-01

    With the increasing number of misuse and abuse of opioids, the resistance to tampering becomes an important attribute for transdermal opioid patches. In this study, drug-containing geopolymer granules were integrated into an adhesive matrix to improve the resistance of fast drug release against some common abuse techniques. Bench testing showed that fentanyl loaded geopolymer granules had better resistance to tampering compared to a commercial fentanyl patch. Moreover, in a pilot in vivo study on a few rats, the granules showed potential to give similar drug plasma concentrations as the commercial fentanyl patch. After integrating geopolymer granules into an adhesive matrix, the new patch showed a better resistance against the investigated tampering tests compared with the commercially available patch. In this study, we showed that incorporating drug loaded geopolymer granules into a patch adhesive has potential to improve the resistance of the fentanyl patch against tampering without compromising the drug release. PMID:25913120

  5. Sperm Patch-Clamp

    PubMed Central

    Lishko, Polina; Clapham, David E.; Navarro, Betsy; Kirichok, Yuriy

    2014-01-01

    Sperm intracellular pH and calcium concentration ([Ca2+]i) are two central factors that control sperm activity within the female reproductive tract. As such, the ion channels of the sperm plasma membrane that alter intracellular sperm [Ca2+] and pH play important roles in sperm physiology and the process of fertilization. Indeed, sperm ion channels regulate sperm motility, control sperm chemotaxis toward the egg in some species, and may trigger the acrosome reaction. Until recently, our understanding of these important molecules was rudimentary due to the inability to patch-clamp spermatozoa and directly record the activity of these ion channels under voltage clamp. Recently, we overcame this technical barrier and developed a method for reproducible application of the patch-clamp technique to mouse and human spermatozoa. This chapter covers important aspects of application of the patch-clamp technique to spermatozoa, such as selection of the electrophysiological equipment, isolation of spermatozoa for patch-clamp experiments, formation of the gigaohm seal with spermatozoa, and transition into the whole-cell mode of recording. We also discuss potential pitfalls in application of the patch-clamp technique to flagellar ion channels. PMID:23522465

  6. STS-62 crew patch

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The STS-62 crew patch depicts the world's first reusable spacecraft on its sixteenth flight. Columbia is in its entry-interface attitude as it prepares to return to Earth. The varied hues of the rainbow on the horizon connote the varied, but complementary, nature of all the payloads united on this mission. The upward-pointing vector shape of the patch is symbolic of America's reach for excellence in its unswerving pursuit to explore the frontiers of space. The brilliant sunrise just beyond Columbia suggests the promise that research in space holds for the hopes and dreams of future generations. The STS-62 insignia was designed by Mark Pestana.

  7. Image inpainting by patch propagation using patch sparsity.

    PubMed

    Xu, Zongben; Sun, Jian

    2010-05-01

    This paper introduces a novel examplar-based inpainting algorithm through investigating the sparsity of natural image patches. Two novel concepts of sparsity at the patch level are proposed for modeling the patch priority and patch representation, which are two crucial steps for patch propagation in the examplar-based inpainting approach. First, patch structure sparsity is designed to measure the confidence of a patch located at the image structure (e.g., the edge or corner) by the sparseness of its nonzero similarities to the neighboring patches. The patch with larger structure sparsity will be assigned higher priority for further inpainting. Second, it is assumed that the patch to be filled can be represented by the sparse linear combination of candidate patches under the local patch consistency constraint in a framework of sparse representation. Compared with the traditional examplar-based inpainting approach, structure sparsity enables better discrimination of structure and texture, and the patch sparse representation forces the newly inpainted regions to be sharp and consistent with the surrounding textures. Experiments on synthetic and natural images show the advantages of the proposed approach. PMID:20129864

  8. Analytical solutions for rotating vortex arrays involving multiple vortex patches

    NASA Astrophysics Data System (ADS)

    Crowdy, Darren; Marshall, Jonathan

    2005-01-01

    A continous two-parameter family of analytical solutions to the Euler equations are presented representing a class of steadily rotating vortex arrays involving N+1 interacting vortex patches where N ≥ 3 is an integer. The solutions consist of a central vortex patch surrounded by an N-fold symmetric alternating array of satellite point vortices and vortex patches. One of the parameters governs the size of the central patch, the other governs the size of the N satellite patches. In the limit where the areas of the satellite vortex patches tend to zero, the solutions degenerate to the exact solutions of Crowdy (J. Fluid Mech. vol. 469, 2002, p. 209). Limiting states are found in which cusps form only on the central patch, only on the satellite patches, or simultaneously on both central and satellite patches. Contour dynamics simulations are used to check the mathematical solutions and test their robustness. The linear stability of a class of "point-vortex models" (in which the patches are replaced by point vortices) are also studied in order to examine the stability of the distributed-vorticity configurations to pure-displacement modes. On the other hand, a desingularization of all point vortices to Rankine vortices leads to a class of "quasi-equilibria" consisting purely of interacting vortex patches close to hydrodynamic equilibrium.

  9. Nitroglycerin Transdermal Patch

    MedlinePlus

    ... verapamil (Calan, Isoptin); ergot-type medications such as bromocriptine (Parlodel), cabergoline, dihydroergotamine (D.H.E. 45, Migranal), ... at any time, especially if you have been drinking alcoholic beverages. To ... during your treatment with nitroglycerin patches.you should know that you ...

  10. Performance statistics of the FORTRAN 4 /H/ library for the IBM system/360

    NASA Technical Reports Server (NTRS)

    Clark, N. A.; Cody, W. J., Jr.; Hillstrom, K. E.; Thieleker, E. A.

    1969-01-01

    Test procedures and results for accuracy and timing tests of the basic IBM 360/50 FORTRAN 4 /H/ subroutine library are reported. The testing was undertaken to verify performance capability and as a prelude to providing some replacement routines of improved performance.

  11. Why 4-H Members Leave: A Study of Discontinuance through Both Current 4-H Members and Former Members

    ERIC Educational Resources Information Center

    Chilek, Kevin Dwayne

    2012-01-01

    4-H members quit. It is part of every 4-H program, and according to the research, it is even part of growing up. If only we knew why they quit, we could possibly do something about it. To date, the reasons youth join 4-H have been more thoroughly researched than the reasons they quit. This study explores why youth choose to discontinue membership…

  12. Sewing Skills Progress Chart. 4-H Textile Science.

    ERIC Educational Resources Information Center

    Scholl, Jan F.

    This document, which was developed for use by Pennsylvania 4-H Club leaders and members, is a chart that can be used to help club members determine and document those sewing skills they already have and those they need to learn as they complete one or more 4-H Club sewing projects. The document begins with a note to club leaders and parents that…

  13. Council of Presidents: A Multifaceted Idea for 4-H

    ERIC Educational Resources Information Center

    Torretta, Alayne

    2015-01-01

    Communication between 4-H professionals and the youth they work with is an important part of a successful 4-H program. By creating a Council of Presidents comprised of officers of all the clubs in your county, you can increase communication while assuring your program addresses all four essential elements. The Council is also as a vehicle for…

  14. 4-H Participation and Science Interest in Youth

    ERIC Educational Resources Information Center

    Heck, Katherine; Carlos, Ramona M.; Barnett, Cynthia; Smith, Martin H.

    2012-01-01

    The study reported here investigated the impacts of participation in 4-H on young people's interest and participation in science. Survey data were collected from relatively large and ethnically diverse samples of elementary and high school-aged students in California. Results indicated that although elementary-grade 4-H members are not more…

  15. Embracing Scientific and Engineering Practices in 4-H

    ERIC Educational Resources Information Center

    Worker, Steven M.

    2013-01-01

    The 4-H Science Initiative has renewed efforts to strengthen 4-H programmatic and evaluation efforts in science and engineering education. A fundamental component of this initiative is to provide opportunities to youth to aid in their development of science process skills; however, emerging research stresses the importance of engaging youth in…

  16. Camping with a Purpose...A 4-H Handbook.

    ERIC Educational Resources Information Center

    Heller, John H.; And Others

    The 4-H handbook focuses on factors to consider and things to be done when developing a camping program. Since the emphasis, structure, and administration of 4-H camping varies, the booklet is flexible enough to be adapted to different state, district, and county situations. Major topics are camping's importance to extension education,…

  17. Socialization of Youth: Role of the 4-H Professional.

    ERIC Educational Resources Information Center

    Freebern, John Robert

    Many professional 4-H staff members lack a sufficient background in the social sciences, fail to understand the complexity of the socialization task, and are not aware of the changes made by other socialization agents in the community. This paper is designed to help the professional 4-H adult worker improve his role as a socialization agent.…

  18. Stabilization of 4H hexagonal phase in gold nanoribbons

    PubMed Central

    Fan, Zhanxi; Bosman, Michel; Huang, Xiao; Huang, Ding; Yu, Yi; Ong, Khuong P.; Akimov, Yuriy A.; Wu, Lin; Li, Bing; Wu, Jumiati; Huang, Ying; Liu, Qing; Eng Png, Ching; Lip Gan, Chee; Yang, Peidong; Zhang, Hua

    2015-01-01

    Gold, silver, platinum and palladium typically crystallize with the face-centred cubic structure. Here we report the high-yield solution synthesis of gold nanoribbons in the 4H hexagonal polytype, a previously unreported metastable phase of gold. These gold nanoribbons undergo a phase transition from the original 4H hexagonal to face-centred cubic structure on ligand exchange under ambient conditions. Using monochromated electron energy-loss spectroscopy, the strong infrared plasmon absorption of single 4H gold nanoribbons is observed. Furthermore, the 4H hexagonal phases of silver, palladium and platinum can be readily stabilized through direct epitaxial growth of these metals on the 4H gold nanoribbon surface. Our findings may open up new strategies for the crystal phase-controlled synthesis of advanced noble metal nanomaterials. PMID:26216712

  19. Texas 4-H Agents' Perceptions of Selected Competencies in the 4-H Professional Research, Knowledge, and Competencies Model

    ERIC Educational Resources Information Center

    Harder, Amy; Wingenbach, Gary J.

    2008-01-01

    There are many competencies necessary for success as a 4-H agent. The 4-H Professional Research, Knowledge, and Competencies (PRKC) Model organizes competencies into six domains: (a) Youth Development, (b) Youth Program Development, (c) Volunteerism, (d) Partnerships, (e) Organizational Systems, and (f) Equity, Access and Opportunity (National 4-H…

  20. Polymer concrete patching manual

    NASA Astrophysics Data System (ADS)

    Fontana, J. J.; Bartholomew, J.

    1982-06-01

    The practicality of using polymer concrete to repair deteriorated portland cement concrete bridge decks and pavements was demonstrated. This manual outlines the procedures for using polymer concrete as a rapid patching material to repair deteriorated concrete. The process technology, materials, equipment, and safety provisions used in manufacturing and placing polymer concrete are discussed. Potential users are informed of the various steps necessary to insure successful field applications of the material.

  1. Growing vortex patches

    NASA Astrophysics Data System (ADS)

    Crowdy, Darren; Marshall, Jonathan

    2004-08-01

    This paper demonstrates that two well-known equilibrium solutions of the Euler equations—the corotating point vortex pair and the Rankine vortex—are connected by a continuous branch of exact solutions. The central idea is to "grow" new vortex patches at two stagnation points that exist in the frame of reference of the corotating point vortex pair. This is done by generalizing a mathematical technique for constructing vortex equilibria first presented by Crowdy [D. G. Crowdy, "A class of exact multipolar vortices," Phys. Fluids 11, 2556 (1999)]. The solutions exhibit several interesting features, including the merging of two separate vortex patches via the development of touching cusps. Numerical contour dynamics methods are used to verify the mathematical solutions and reveal them to be robust structures. The general issue of how simple vortex equilibria can be continued continuously to more complicated ones with very different vortical topologies is discussed. The solutions are examples of exact solutions of the Euler equations involving multiple interacting vortex patches.

  2. Sodium diffusion in 4H-SiC

    SciTech Connect

    Linnarsson, M. K. Hallén, A.

    2014-09-01

    Sodium diffusion has been studied in p-type 4H-SiC. Heat treatments have been performed from 1200 °C to 1800 °C for 1 min to 4 h. Secondary ion mass spectrometry has been used to measure the sodium distribution. We show that sodium has a considerable mobility at 1200 °C in p-type 4H-SiC. On the other hand for sodium atoms trapped at suitable sites the mobility is limited up to 1800 °C. Trap limited diffusion kinetics is suggested and an effective diffusivity has been extracted with an activation energy of 4 eV for sodium diffusion in p-type 4H-SiC.

  3. Comparative study of patches for liquid cooled garments.

    NASA Technical Reports Server (NTRS)

    Shitzer, A.; Chambers, A. B.

    1973-01-01

    Tests were performed on 12 cooling patches of various designs to establish criteria for the evaluation of their performance in liquid-cooled suits in industrial, military and aerospace applications. The thermal effectiveness value was 0.088 for patch designs with a double spiral flow pattern, and 0.075 for patch designs with a parallel flow pattern. The ratio of thermal energy transfer rate to cooling-medium pumping power requirement is indicated as the prime performance characteristic to be considered in the selection and rating of cooling patches.

  4. Patch antenna terahertz photodetectors

    SciTech Connect

    Palaferri, D.; Todorov, Y. Chen, Y. N.; Madeo, J.; Vasanelli, A.; Sirtori, C.; Li, L. H.; Davies, A. G.; Linfield, E. H.

    2015-04-20

    We report on the implementation of 5 THz quantum well photodetector exploiting a patch antenna cavity array. The benefit of our plasmonic architecture on the detector performance is assessed by comparing it with detectors made using the same quantum well absorbing region, but processed into a standard 45° polished facet mesa. Our results demonstrate a clear improvement in responsivity, polarization insensitivity, and background limited performance. Peak detectivities in excess of 5 × 10{sup 12} cmHz{sup 1/2}/W have been obtained, a value comparable with that of the best cryogenic cooled bolometers.

  5. Isomer Energy Differences for the C4H3 and C4H5 Isomers UsingDiffusion Monte Carlo

    SciTech Connect

    Domin, D.; Lester Jr., W.A.; Whitesides, R.; Frenklach, M.

    2007-12-01

    A new diffusion Monte Carlo study is performed on the isomers of C{sub 4}H{sub 3} and C{sub 4}H{sub 5} emulating the methodology of a previous study [Int. J. Chem. Kinetics 33, 808 (2001)]. Using the same trial wave function form of the previous study, substantially different isomerization energies were found owing to the use of larger walker populations in the present work. The energy differences between the E and I isomers of C{sub 4}H{sub 3} were found to be 10.5 {+-} 0.5 kcal/mol and for C{sub 4}H{sub 5}, 9.7 {+-} 0.6 kcal/mol. These results are in reasonable accord with recent MRCI and CCSD(T) findings.

  6. Statistics for Patch Observations

    NASA Astrophysics Data System (ADS)

    Hingee, K. L.

    2016-06-01

    In the application of remote sensing it is common to investigate processes that generate patches of material. This is especially true when using categorical land cover or land use maps. Here we view some existing tools, landscape pattern indices (LPI), as non-parametric estimators of random closed sets (RACS). This RACS framework enables LPIs to be studied rigorously. A RACS is any random process that generates a closed set, which encompasses any processes that result in binary (two-class) land cover maps. RACS theory, and methods in the underlying field of stochastic geometry, are particularly well suited to high-resolution remote sensing where objects extend across tens of pixels, and the shapes and orientations of patches are symptomatic of underlying processes. For some LPI this field already contains variance information and border correction techniques. After introducing RACS theory we discuss the core area LPI in detail. It is closely related to the spherical contact distribution leading to conditional variants, a new version of contagion, variance information and multiple border-corrected estimators. We demonstrate some of these findings on high resolution tree canopy data.

  7. Tiling Motion Patches.

    PubMed

    Hyun, Kyunglyul; Kim, Manmyung; Hwang, Youngseok; Lee, Jehee

    2013-05-01

    Simulating multiple character interaction is challenging because character actions must be carefully coordinated to align their spatial locations and synchronized with each other. We present an algorithm to create a dense crowd of virtual characters interacting with each other. The interaction may involve physical contacts, such as hand shaking, hugging, and carrying a heavy object collaboratively. We address the problem by collecting deformable motion patches, each of which describes an episode of multiple interacting characters, and tiling them spatially and temporally. The tiling of motion patches generates a seamless simulation of virtual characters interacting with each other in a non-trivial manner. Our tiling algorithm uses a combination of stochastic sampling and deterministic search to address the discrete and continuous aspects of the tiling problem. Our tiling algorithm made it possible to automatically generate highly-complex animation of multiple interacting characters. We achieved the level of complexity far beyond the current state-of-the-art animation techniques could generate, in terms of the diversity of human behaviors and the spatial/temporal density of interpersonal interactions. PMID:23669532

  8. Tiling motion patches.

    PubMed

    Hyun, Kyunglyul; Kim, Manmyung; Hwang, Youngseok; Lee, Jehee

    2013-11-01

    Simulating multiple character interaction is challenging because character actions must be carefully coordinated to align their spatial locations and synchronized with each other. We present an algorithm to create a dense crowd of virtual characters interacting with each other. The interaction may involve physical contacts, such as hand shaking, hugging, and carrying a heavy object collaboratively. We address the problem by collecting deformable motion patches, each of which describes an episode of multiple interacting characters, and tiling them spatially and temporally. The tiling of motion patches generates a seamless simulation of virtual characters interacting with each other in a nontrivial manner. Our tiling algorithm uses a combination of stochastic sampling and deterministic search to address the discrete and continuous aspects of the tiling problem. Our tiling algorithm made it possible to automatically generate highly complex animation of multiple interacting characters. We achieve the level of interaction complexity far beyond the current state of the art that animation techniques could generate, in terms of the diversity of human behaviors and the spatial/temporal density of interpersonal interactions. PMID:24029911

  9. Patched Conic Trajectory Code

    NASA Technical Reports Server (NTRS)

    Park, Brooke Anderson; Wright, Henry

    2012-01-01

    PatCon code was developed to help mission designers run trade studies on launch and arrival times for any given planet. Initially developed in Fortran, the required inputs included launch date, arrival date, and other orbital parameters of the launch planet and arrival planets at the given dates. These parameters include the position of the planets, the eccentricity, semi-major axes, argument of periapsis, ascending node, and inclination of the planets. With these inputs, a patched conic approximation is used to determine the trajectory. The patched conic approximation divides the planetary mission into three parts: (1) the departure phase, in which the two relevant bodies are Earth and the spacecraft, and where the trajectory is a departure hyperbola with Earth at the focus; (2) the cruise phase, in which the two bodies are the Sun and the spacecraft, and where the trajectory is a transfer ellipse with the Sun at the focus; and (3) the arrival phase, in which the two bodies are the target planet and the spacecraft, where the trajectory is an arrival hyperbola with the planet as the focus.

  10. Disruption of PF4/H multimolecular complex formation with a minimally anticoagulant heparin (ODSH)

    PubMed Central

    Joglekar, Manali V.; Quintana Diez, Pedro M.; Marcus, Stephen; Qi, Rui; Espinasse, Benjamin; Wiesner, Mark R.; Pempe, Elizabeth; Liu, Jian; Monroe, Dougald M.; Arepally, Gowthami M.

    2015-01-01

    Summary Recent studies have shown that ultra-large complexes (ULCs) of platelet factor 4 (PF4) and heparin (H) play an essential role in the pathogenesis of Heparin-Induced Thrombocytopenia (HIT), an immune-mediated disorder caused by PF4/H antibodies. Because antigenic PF4/H ULCs assemble through non-specific electrostatic interactions, we reasoned that disruption of charge-based interactions can modulate the immune response to antigen. We tested a minimally anticoagulant compound (2-O, 3-O desulfated heparin or ODSH) with preserved charge to disrupt PF4/H complex formation and immunogenicity. We show that ODSH disrupts complexes when added to pre-formed PF4/H ULCs and prevents ULC formation when incubated simultaneously with PF4 and UFH. In other studies, we show that excess ODSH reduces HIT antibody (Ab) binding in immunoassays and that PF4/ODSH complexes do not cross-react with HIT Abs. When ODSH and UFH are mixed at equimolar concentrations, we show that there is a negligible effect on amount of protamine required for heparin neutralization and reduced immunogenicity of PF4/UFH in the presence of ODSH. Taken together, these studies suggest that ODSH can be used concurrently with UFH to disrupt PF4/H charge interactions and provides a novel strategy to reduce antibody mediated complications in HIT. PMID:22318669

  11. Density Functional Exploration of C4H3N Isomers.

    PubMed

    Custer, Thomas; Szczepaniak, Urszula; Gronowski, Marcin; Fabisiewicz, Emilia; Couturier-Tamburelli, Isabelle; Kołos, Robert

    2016-07-28

    Molecules having C4H3N stoichiometry are of astrophysical interest. Two of these, methylcyanoacetylene (CH3C3N) and its structural isomer allenyl cyanide (H2CCCHN), have been observed in interstellar space, while several more have been examined in laboratories. Here we describe, for a broad range of C4H3N isomers, density functional calculations (B3LYP/aug-cc-pVTZ) of molecular parameters including the energetics, geometries, rotational constants, electric dipole moments, polarizabilities, vibrational IR frequencies, IR absorption intensities, and Raman activities. Singlet-triplet splittings as well as singlet vertical electronic excitation energies are given for selected species. The identification of less stable C4H3N molecules, generated in ongoing spectroscopic experiments, relies heavily on these quantum chemical predictions. PMID:27341606

  12. Bright patches on Ariel

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Distinct bright patches are visible on Ariel, the brightest of Uranus' five largest satellites. Voyager 2 obtained this image Jan. 22, 1986, from a distance of 2.52 million kilometers (1.56 million miles). The clear-filter image, obtained with the narrow-angle camera, shows a resolution of 47 km (29 miles). Ariel is about 1,300 km (800 mi) in diameter. This image shows several distinct bright areas that reflect nearly 45 percent of the incident sunlight; on average, the satellite displays a reflectivity of about 25-30 percent. The bright areas are probably fresh water ice, perhaps excavated by impacts. The south pole of Ariel is slightly off center of the disk in this view. Voyager 2 will obtain its best views of the satellite on Jan. 24, at a closest-approach distance of 127,000 km (79,000 mi). The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  13. Granuloma annulare, patch type.

    PubMed

    Victor, Frank C; Mengden, Stephanie

    2008-01-01

    A 64-year-old man was referred to the Bellevue Hospital Center Dermatology Clinic for evaluation of an asymptomatic eruption on his left inner arm, which had been present for 4 months and was unresponsive to topical anti-fungal therapy. One month after the initial eruption, 2 similar, asymptomatic lesions appeared on the right inner arm. The lesions were slowly expanding. A biopsy specimen from the left medial arm was consistent with interstitial granuloma annulare. The patient's clinical presentation was consistent with patch-type granuloma annulare. He was treated with a mid-potency topical glucocorticoid twice daily for 4 weeks without benefit. Since the eruption was asymptomatic, treatment was discontinued. PMID:18627757

  14. Stress field sensitivity of a composite patch repair as a result of varying patch thickness

    NASA Astrophysics Data System (ADS)

    Siener, Michael P.

    The feasibility of increasing the efficiency of a composite scarf joint and, hence, of the composite patch repair, was investigated by using single lap joint configurations based on a variety of patch material thicknesses and stiffnesses, and testing for the elastic response and the strength capability. Stress analyses of these configurations were carried out and compared to the results from tests. It was found that, by reorienting plies in the principal stress direction, it is possible to reduce the number of plies and thickness required to form a usable composite repair patch. The results also show that it may be necessary to incorporate the nonlinear adhesive behavior into the model to account for the extensional response of the adherends.

  15. The Big E (Energy). 4-H Member Guide, Unit 2.

    ERIC Educational Resources Information Center

    Caldwell, William; And Others

    This activity and record book is designed for unit 2 (ages 12-14) of the Nebraska 4-H Energy Project. Aims, energy attitudes to be developed, and instructions are provided for each activity. Activities include: (1) a word search of energy-related words (with definitions provided); (2) determining fuel waste; (3) reading electric/gas meters and…

  16. Keys To The Kansas Environment. 4-H School Enrichment Program.

    ERIC Educational Resources Information Center

    Kansas State Univ., Manhattan. Extension Service.

    The 4-H Club packet for preschool and elementary school children contains nine "keys", or short learning exercises, designed to enrich science and environmental education both in and out of the classroom. Each "key" includes the purpose of the activity, the intended audience, the best time of the year for the activity, background information,…

  17. Marketing Strategies for Recruiting 4-H Members in West Virginia.

    ERIC Educational Resources Information Center

    Wingenbach, Gary J.; Nestor, Cheryl; Lawrence, Layle D.; Gartin, Stacy A.; Woloshuk, Jean; Mulkeen, Patricia

    2000-01-01

    According to a survey of 174 West Virginia 4-H members aged 13-18, the Internet and word of mouth were most effective in recruiting new members. Active messages stressing camps, fun, and friendship had the most influence on retention. A statewide marketing plan was recommended. (SK)

  18. Self-Protection: A New Approach to 4-H Health.

    ERIC Educational Resources Information Center

    Wright, Sharon K. B.

    This document introduces the issue of self-protection as the Minnesota 4-H Youth Development response to self-destructive behavior among adolescents. It presents findings from a statewide survey of over 36,000 secondary school students using the Minnesota Adolescent Health Survey. Responses are given in the areas of health, school attitudes,…

  19. CONSERVING OUR NATURAL RESOURCES, A 4-H LEADER'S GUIDE.

    ERIC Educational Resources Information Center

    AMICK, W. ROBERT; AND OTHERS

    AN EFFECTIVE 4-H CONSERVATION PROGRAM IS DEVELOPED AROUND THE FOLLOWING BASIC CONCEPTS--(1) MAN IS A PART OF THE NATURAL WORLD, IN WHICH THERE ARE MANY VALUABLE MATERIALS, (2) MAN HAS LEARNED TO USE MANY OF THOSE MATERIALS FOR HUMAN SUSTENANCE AND BETTERMENT, AND (3) MAN'S ECONOMIC, SOCIAL, AND GENERAL WELFARE IS LARGELY DEPENDENT UPON THE MANNER…

  20. "Ohio 4-H CARTEENS": Peer Intervention Safety Program.

    ERIC Educational Resources Information Center

    Cropper, Rebecca J.

    1999-01-01

    Ohio 4-H's CARTEENS seeks to reduce juvenile traffic violations in a program designed and presented by teen peer educators with guidance and technical assistance from the state highway patrol. Teens examined court data to determine content, which includes defensive driving, rural road safety, and dealing with peer pressure. (SK)

  1. Effectiveness of the Indiana 4-H Tractor Program: Alumni Perceptions.

    ERIC Educational Resources Information Center

    Carrabba, James J., Jr.; Talbert, B. Allen; Field, William E.; Tormoehlen, Roger

    2001-01-01

    Responses from Indiana 4-H tractor driving contestants 1982-197 (n=139) showed that 74% were employed on farms; most felt the contests effectively taught tractor safety and made them generally aware of safety. However, many still engaged in risky behaviors such as not wearing seatbelts in tractors with rollover protective structures or allowing…

  2. The Big E (Energy). 4-H Member Guide, Unit 3.

    ERIC Educational Resources Information Center

    Caldwell, William; And Others

    This activity and record book is designed for unit 3 (ages 15-19) of the Nebraska 4-H Energy Project. Aims, energy attitudes to be developed, and instructions are provided for each activity. Activities include: (1) determining ways to reduce energy waste with hot water heaters; (2) making personal choices about using appliances; (3) conducting a…

  3. A Phenomenological Look at 4-H Volunteer Motives for Service

    ERIC Educational Resources Information Center

    Schrock, Jessalyn; Kelsey, Kathleen D.

    2013-01-01

    Volunteers play a vital role in 4-H programs. Without their service, many programs would not be possible. Understanding volunteer motives provides Extension educators with tools for finding high-quality volunteers. The research reported here used McClelland's (1985) framework for motivation (affiliation, achievement, and power) and…

  4. Minnesota 4-H Youth Program Quality Improvement Model

    ERIC Educational Resources Information Center

    Herman, Margo; Grant, Samantha

    2015-01-01

    The University of Minnesota Extension Center for Youth Development made an organizational decision in 2011 to invest in a system-wide approach to implement youth program quality into the 4-H program using the Youth Program Quality Assessment (YPQA) tool. This article describes the four key components to the Minnesota Youth Program Quality…

  5. The Evaluation Attitudes and Practices of 4-H Educators

    ERIC Educational Resources Information Center

    Lekies, Kristi S.; Bennett, Amanda M.

    2011-01-01

    Extension educators are expected to conduct program evaluation. An Internet survey was sent to county 4-H educators in Ohio to examine their evaluation attitudes and practices, as well as barriers to conducting evaluation. Respondents indicated a range of attitudes about evaluation and limited use of different designs and methods. Having enough…

  6. Fashion Revue. 4-H Textile Science Activity Guide.

    ERIC Educational Resources Information Center

    Scholl, Jan

    This publication was developed to help students participating in Fashion Review, a 4-H event in which students model a clothing outfit and accessories and are judged on their modeling ability, their presentation, and how well the clothing and accessory choices complement the students' skin tones, hair color, figure or physique, personality, and…

  7. Ethinyl Estradiol and Norelgestromin Transdermal Patch

    MedlinePlus

    ... the skin. One patch is applied once a week for 3 weeks, followed by a patch-free week. Follow the directions on your prescription label carefully, ... new patch on the same day of the week (the Patch Change Day). Apply a new patch ...

  8. Water Worlds. 4-H Member's Guide M-5-18; 4-H Leaders Guide L-5-18.

    ERIC Educational Resources Information Center

    Hawkes, Janet E.; And Others

    This pocket folder of materials is designed to provide children aged 9 to 12 with an opportunity to explore and observe aquatic environments. The package includes a 4-H Leader's guide, member's guide, and supplementary materials. The leader's guide contains safety considerations, tips and techniques, and additional activities for getting started…

  9. New Jersey 4-H Goat Extravaganza: Efficiently Meeting the Educational Needs of 4-H Goat Project Members, Volunteers, and Parents

    ERIC Educational Resources Information Center

    Ripberger, Chad

    2014-01-01

    The 4-H Goat Extravaganza maximizes limited resources to help youth and adults develop knowledge and skills in goat care and management. It capitalizes on the talents and interests of volunteers to efficiently combine a goat-themed art show, team presentation contest, quiz bowl, skillathon, and adult workshop into 1 day. This article outlines the…

  10. Starting and Maintaining a Marine Aquarium: 4-H Members Guide [and] 4-H Member's Project Record Book.

    ERIC Educational Resources Information Center

    Crenshaw, Neil

    The guide and the project record book included in this document are designed for 4-H members who would like to start a salt-water aquarium project. The guide includes the following topics: (1) general requirements for salt-water aquariums; (2) directions for making an aquarium; (3) suggestions for where to locate it; (4) pros and cons of using…

  11. Litter Control Achievement - Ohio 4-H Club Score Sheet [and] Activity Guides 1 through 7. 4-H Pilot Program 918.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Cooperative Extension Service.

    Seven activity guides, evaluation sheet, and club scoresheet have been prepared for Ohio 4-H clubs' litter education program. Topics of the seven activity guides include: (1) general guidelines and types of activities; (2) little known facts about waste/litter; (3) guidelines for a walking tour; (4) fact sheet (questionnaire) related to garbage;…

  12. Edge of polar cap patches

    NASA Astrophysics Data System (ADS)

    Hosokawa, K.; Taguchi, S.; Ogawa, Y.

    2016-04-01

    On the night of 4 December 2013, a sequence of polar cap patches was captured by an all-sky airglow imager (ASI) in Longyearbyen, Norway (78.1°N, 15.5°E). The 630.0 nm airglow images from the ASI of 4 second exposure time, oversampled the emission of natural lifetime (with quenching) of at least ˜30 sec, introduce no observational blurring effects. By using such high-quality ASI images, we succeeded in visualizing an asymmetry in the gradients between the leading/trailing edges of the patches in a 2-D fashion. The gradient in the leading edge was found to be 2-3 times steeper than that in the trailing edge. We also identified fingerlike structures, appearing only along the trailing edge of the patches, whose horizontal scale size ranged from 55 to 210 km. These fingers are considered to be manifestations of plasma structuring through the gradient-drift instability (GDI), which is known to occur only along the trailing edge of patches. That is, the current 2-D observations visualized, for the first time, how GDI stirs the patch plasma and such a mixing process makes the trailing edge more gradual. This result strongly implies a close connection between the GDI-driven plasma stirring and the asymmetry in the large-scale shape of patches and then suggests that the fingerlike structures can be used as markers to estimate the fine-scale structure in the plasma flow within patches.

  13. Phosphorus implantation into 4H-silicon carbide

    SciTech Connect

    Capano, M.A.; Santhakumar, R.; Venugopal, R.; Melloch, M.R.; Cooper, J.A. Jr.

    2000-02-01

    Sheet resistances in nitrogen- and phosphorus-implanted 4H-SiC are measured to assess the time and temperature dependencies of this variable. In 4H-SiC implanted with 3 x 10{sup 15} cm{sup {minus}2} nitrogen ions to a depth of 2,800 {angstrom}, the minimum sheet resistance observed is 534 {Omega}/{open{underscore}square}, a record low value for any implanted element into any polytype of SiC. Time-independent sheet resistances are observed following anneals at 1,700 C for nitrogen and phosphorus samples. Lower temperature anneals produce sheet resistances which decrease monotonically with increasing time of anneal. Overall, sheet resistances from phosphorus-implanted 4H-SiC are an order of magnitude below those measured from nitrogen implanted samples. The response of phosphorus to low-temperature annealing is significant, and sheet resistances below 500 {Omega}/{open{underscore}square} are achieved at 1,200 C. Activation of phosphorus is attempted in an oxidizing atmosphere with and without prior argon annealing. A three-hour gate oxidation in wet O{sub 2} at 1,150 C, followed by a 30 min argon anneal, produced a sheet resistance of 1081 {Omega}/{open{underscore}square}. Oxidation after argon annealing caused sheet resistances to increase by about 20% compared to samples subjected solely to argon annealing. It is also found that oxide growth rates are much higher over phosphorus implanted than over unimplanted 4H-SiC. Reasons for the disparity in sheet resistances between nitrogen and phosphorus implants, and for the difference in oxide growth rates are suggested.

  14. A Perfect Fit: 4-H Involvement for Youth with Disabilities. A Leader's Guide.

    ERIC Educational Resources Information Center

    Schnepf, Greg W.; And Others

    This guide for 4-H leaders and volunteers offers information to help integrate youth with disabilities into various 4-H programs. After an introduction, a section on 4-H and mainstreaming reviews the mission of 4-H; considers what 4-H has to offer youth; defines mainstreaming; notes the benefits of mainstreaming; and distinguishes among the terms…

  15. Temperature dependence of current-and capacitance-voltage characteristics of an Au/4H-SiC Schottky diode

    NASA Astrophysics Data System (ADS)

    Gülnahar, Murat

    2014-12-01

    In this study, the current-voltage (I-V) and capacitance-voltage (C-V) measurements of an Au/4H-SiC Schottky diode are characterized as a function of the temperature in 50-300 K temperature range. The experimental parameters such as ideality factor and apparent barrier height presents to be strongly temperature dependent, that is, the ideality factor increases and the apparent barrier height decreases with decreasing temperature, whereas the barrier height values increase with the temperature for C-V data. Likewise, the Richardson plot deviates at low temperatures. These anomaly behaviors observed for Au/4H-SiC are attributed to Schottky barrier inhomogeneities. The barrier anomaly which relates to interface of Au/4H-SiC is also confirmed by the C-V measurements versus the frequency measured in 300 K and it is interpreted by both Tung's lateral inhomogeneity model and multi-Gaussian distribution approach. The values of the weighting coefficients, standard deviations and mean barrier height are calculated for each distribution region of Au/4H-SiC using the multi-Gaussian distribution approach. In addition, the total effective area of the patches NAe is obtained at separate temperatures and as a result, it is expressed that the low barrier regions influence meaningfully to the current transport at the junction. The homogeneous barrier height value is calculated from the correlation between the ideality factor and barrier height and it is noted that the values of standard deviation from ideality factor versus q/3kT curve are in close agreement with the values obtained from the barrier height versus q/2kT variation. As a result, it can be concluded that the temperature dependent electrical characteristics of Au/4H-SiC can be successfully commented on the basis of the thermionic emission theory with both models.

  16. Creation of polar cap patches

    NASA Astrophysics Data System (ADS)

    Hosokawa, K.; Taguchi, S.; Ogawa, Y.

    2014-12-01

    Polar cap patches, which are islands of enhanced plasma density drifting anti-sunward, are one of the outstanding phenomena in the polar cap F region ionosphere. In the last decade, data from all-sky airglow imagers have been extensively used for better understanding the propagation of patches in the central polar cap region. But still, it has been rather difficult to capture the birth of patches in their generation region near the dayside cusp, because, in most places, the dayside part of the polar cap ionosphere is sunlit even in winter. In Longyearbyen (78.1N, 15.5E), Norway, however, optical observations are possible near the dayside cusp region in a limited period around the winter solstice. This enables us to directly image how polar cap patches are born in the cusp. In this paper, we present a few intervals of daytime optical observations, during which polar cap patches were generated within the field-of-view of an all-sky imager in Longyearbyen. During all the intervals studied here, we identified several signatures of poleward moving auroral forms (PMAF) in the equatorward half of the field-of-view, which are known as ionospheric manifestations of dayside reconnection. Interestingly, patches were directly produced from such poleward moving auroral signatures and propagated poleward along the anti-sunward convection near the cusp. In the literature, Lorentzen et al. (2012) first reported such a direct production of patches from PMAFs. During the current observations, however, we succeeded in tracking the propagation of patches until they reached the poleward edge of the field-of-view of the imager. This confirms that the faint airglow structures produced from PMAFs were actually transported for a long distance towards the central polar cap area; thus, polar cap patches were produced. From this set of observations, we suggest that polar cap patches during moderately disturbed conditions (i.e, non-storm time conditions) can be directly produced by the

  17. Formulation Optimization of Arecoline Patches

    PubMed Central

    Wu, Pao-Chu; Tsai, Pi-Ju; Lin, Shin-Chen; Huang, Yaw-Bin

    2014-01-01

    The response surface methodology (RSM) including polynomial equations has been used to design an optimal patch formulation with appropriate adhesion and flux. The patch formulations were composed of different polymers, including Eudragit RS 100 (ERS), Eudragit RL 100 (ERL) and polyvinylpyrrolidone K30 (PVP), plasticizers (PEG 400), and drug. In addition, using terpenes as enhancers could increase the flux of the drug. Menthol showed the highest enhancement effect on the flux of arecoline. PMID:24707220

  18. American crew patch of the ASTP mission

    NASA Technical Reports Server (NTRS)

    1975-01-01

    This is the American crew patch of the joint U.S.-USSR Apollo Soyuz Test Project (ASTP) scheduled for July 1975. Of circular design, the patch as a colored border area, outlined in red, with the names of the five crewmen and the words Apollo in English and Soyuz in Russian around an artist's concept of the Apollo and Soyuz spacecraft about to dock in Earth orbit. The bright Sun and the blue and white Earth are in the background. The white stars on the blue background represent American Astronauts Thomas P. Stafford, Vance D. Brand, and Donald K. Slayton. The dark gold stars on the red background represent Soviet Cosmonauts Aleskey A. Leonov, and Valeriy N. Kubasov.

  19. Structural health monitoring of composite repair patches in bridge rehabilitation

    NASA Astrophysics Data System (ADS)

    Wu, Zhanjun; Ghosh, Kumar; Qing, Xinlin; Karbhari, Vistasp; Chang, Fu-Kuo

    2006-03-01

    In recent years, there are many issues involving safety on old bridges, aircrafts and other structures, which threaten the lives of the people using those structures, as well as the structures themselves. To prevent future failure, various measures are being taken. Structure rehabilitations with carbon fiber reinforced composite patches have been adopted and demonstrated to be an excellent way to enhance/repair the structures and prolong the service life. However, there are still many problems residing in this kind of technology that remain unsolved, for example, the failure of the interface between composite repair patches and their host structures. This is a critical issue that must be addressed in order to show the viability of composite patches. In order to study debond occurring between composite repair patches and their host structures, a structure health monitoring scheme was demonstrated on a concrete bridge model in the laboratory. The system is based on active sensing with diagnostic lamb waves, in which piezoelectric transducers are used as both sensors and actuators. In the test, six SMART Layers, each having eight piezoelectirc transducers, were integrated with two composite repair strips on the deck slab of the concrete bridge model. For the three diagnostic layers with each composite repair patch, two layers were bonded on the top surface of the patch, and the other is embedded at the interface between the composite repair patch and the deck slab of the concrete bridge model. The loading procedure of the test included three phases. First, the bridge model was preloaded to initiate cracks on the deck slabs and the repair patches were then implemented. Second, the load was raised to reach the shear capacity of the girders of the bridge model and then the repair patches were implemented on those girders. Lastly, the structure was loaded to damage the deck slabs. During the test, the initiation and development of debond between composite repair patches

  20. Taro corms mucilage/HPMC based transdermal patch: an efficient device for delivery of diltiazem hydrochloride.

    PubMed

    Sarkar, Gunjan; Saha, Nayan Ranjan; Roy, Indranil; Bhattacharyya, Amartya; Bose, Madhura; Mishra, Roshnara; Rana, Dipak; Bhattacharjee, Debashis; Chattopadhyay, Dipankar

    2014-05-01

    The aim of this work is to examine the effectiveness of mucilage/hydroxypropylmethylcellulose (HPMC) based transdermal patch (matrix type) as a drug delivery device. We have successfully extracted mucilage from Colocasia esculenta (Taro) corms and prepared diltiazem hydrochloride incorporated mucilage/HPMC based transdermal patches using various wt% of mucilage by the solvent evaporation technique. Characterization of both mucilage and transdermal patches has been done by several techniques such as Molisch's test, organoleptic evaluation of mucilage, mechanical, morphological and thermal analysis of transdermal patches. Skin irritation test is studied on hairless Albino rat skin showing that transdermal patches are apparently free of potentially hazardous skin irritation. Fourier transform infrared analysis shows that there is no interaction between drug, mucilage and HPMC while scanning electron microscopy shows the surface morphology of transdermal patches. In vitro drug release time of mucilage-HPMC based transdermal patches is prolonged with increasing mucilage concentration in the formulation. PMID:24556117

  1. Periodicities of polar cap patches

    NASA Astrophysics Data System (ADS)

    Hosokawa, K.; Taguchi, S.; Ogawa, Y.; Aoki, T.

    2013-01-01

    A highly sensitive all-sky electron multiplier charge-coupled device airglow imager has been operative in Longyearbyen, Norway since October 2011. The imager captures 630.0 nm all-sky images with an exposure time of 4 s, which is about 10 times shorter than that achieved by conventional cooled CCD imagers. This allows us to visualize the structure of polar cap patches without blurring effects and better estimate their periodicities. We present, as one of the first results from the imager, an event of successive appearance of patches on the night of 21 December 2011. A time series of the optical intensity at zenith showed modulations having two distinguished periods, one at 40 min and the other at 5-12 min. One possible explanation is that such a coexistence of two different periodicities is a manifestation of simultaneous occurrence of patch generation processes on the 40 min periodicity was created by large-scale reconfiguration of the dayside convection pattern while the 5-12 min modulations were closely associated with mechanisms driven by pulsed reconnection on the dayside magnetopause. Such a combined effect of multiple patch generation processes may play a role in structuring patches; thus, it would be of particular importance for evaluating the space weather effects in the trans-ionospheric communications environment in the polar cap.

  2. The Effects of Nutrient Dynamics on Root Patch Choice

    PubMed Central

    Gersani, Mordechai; Ovadia, Ofer; Novoplansky, Ariel

    2010-01-01

    Plants have been recognized to be capable of allocating more roots to rich patches in the soil. We tested the hypothesis that in addition to their sensitivity to absolute differences in nutrient availability, plants are also responsive to temporal changes in nutrient availability. Different roots of the same Pisum sativum plants were subjected to variable homogeneous and heterogeneous temporally – dynamic and static nutrient regimes. When given a choice, plants not only developed greater root biomasses in richer patches; they discriminately allocated more resources to roots that developed in patches with increasing nutrient levels, even when their other roots developed in richer patches. These results suggest that plants are able to perceive and respond to dynamic environmental changes. This ability might enable plants to increase their performance by responding to both current and anticipated resource availabilities in their immediate proximity. PMID:20520811

  3. Transdermal Buprenorphine Patches for Postoperative Pain Control in Abdominal Surgery

    PubMed Central

    Kumar, Santosh; Singh, Prithvi Kumar; Verma, Reetu; Chandra, Girish; Bhatia, Vinod Kumar; Singh, Dinesh; Bogra, Jaishri

    2016-01-01

    Introduction Buprenorphine is a semi-synthetic derivative of thebaine; its low concentration is sufficient to provide effective pain relief. Aim To evaluate the efficacy of transdermal buprenorphine patch in postoperative pain management. Materials and Methods After ethical approval and taking informed consent from the patients, they were randomized into three groups (n=30 in each group) using a computer generated random number table. Group A: placebo patch; Group B: buprenorphine (10mg) patch and Group C: buprenorphine (20mg) patch. Haemodynamic and analgesic effects were compared by using analysis of variance (ANOVA) followed by Turkey’s post hoc test. The proportion of side effects was compared using the Chi-square test. Results Haemodynamic changes were not statistically different in all the three groups A, B and C, whereas at the end of surgery VAS score of Group A subjects was significantly higher (4.93±0.98) as compared to Group B (1.73±0.64) and Group C (1.40±0.50). On 2nd postoperative day, no pain was reported by the Group C patients and on 4th day after surgery, no pain was reported by Group B patients. Conclusion The transdermal buprenorphine patch (20mg) was effective in attenuating postoperative pain, maintaining haemodynamic stability requiring no rescue analgesia, with fewer postoperative rescue analgesic requirements in low dose of buprenorphine patch (10mg) group. PMID:27504383

  4. Hydrogen Gas Sensors Fabricated on Atomically Flat 4H-SiC Webbed Cantilevers

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Spry, David J.; Trunek, Andrew J.; Evans, Laura J.; Chen, Liang-Yu; Hunter, Gary W.; Androjna, Drago

    2007-01-01

    This paper reports on initial results from the first device tested of a "second generation" Pt-SiC Schottky diode hydrogen gas sensor that: 1) resides on the top of atomically flat 4H-SiC webbed cantilevers, 2) has integrated heater resistor, and 3) is bonded and packaged. With proper selection of heater resistor and sensor diode biases, rapid detection of H2 down to concentrations of 20 ppm was achieved. A stable sensor current gain of 125 +/- 11 standard deviation was demonstrated during 250 hours of cyclic test exposures to 0.5% H2 and N2/air.

  5. Intergenerational Panels at Centennial Events: Stimulating Discussion about Continuity and Change in the 4-H Program

    ERIC Educational Resources Information Center

    Kaplan, Matthew S.; Weikert, Ben; Scholl, Jan; Rushton, Mya

    2013-01-01

    This article introduces an intergenerational strategy for organizations planning centennial celebratory events. The methods and findings from the 4-H through the Generations session conducted at the joint 4-H Leadership Conference and 4-H Leaders Forum to celebrate the Pennsylvania 4-H Centennial are reported. Youth and adult participants shared…

  6. North Central Region 4-H Volunteers: Documenting Their Contributions and Volunteer Development

    ERIC Educational Resources Information Center

    Nippolt, Pamela Larson; Pleskac, Sue; Schwartz, Vicki; Swanson, Doug

    2012-01-01

    Documenting volunteer contributions strengthens Extension partnerships with volunteers. A team of North Central Region 4-H volunteer specialists collaborated to conduct a study of 4-H volunteer contributions and impacts related to working with youth within the 4-H program. Over three thousand (3,332) 4-H volunteers from throughout the 12-state…

  7. Experimental investigations of the hypernucleus Λ4H

    NASA Astrophysics Data System (ADS)

    Achenbach, P.; Schulz, F.; Aulenbacher, S.; Beričič, J.; Bleser, S.; Böhm, R.; Bosnar, D.; Correa, L.; Distler, M. O.; Esser, A.; Fonvieille, H.; Friščić, I.; Fujii, Y.; Fujita, M.; Gogami, T.; Kanda, H.; Kaneta, M.; Kegel, S.; Kohl, Y.; Kusaka, W.; Margaryan, A.; Merkel, H.; Mihovilovič, M.; Müller, U.; Nagao, S.; Nakamura, S. N.; Pochodzalla, J.; Sanchez Lorente, A.; Schlimme, B. S.; Schoth, M.; Sfienti, C.; Širca, S.; Steinen, M.; Takahashi, Y.; Tang, L.; Thiel, M.; Tsukada, K.; Tyukin, A.; Weber, A.

    2016-03-01

    Negatively charged pions from two-body decays of stopped Λ4H hypernuclei were studied in 2012 at the Mainz Microtron MAMI, Germany. The momenta of the decay-pions were measured with unprecedented precision by using high-resolution magnetic spectrometers. A challenge of the experiment was the tagging of kaons from associated K+∧ production off a Be target at very forward angles. In the year 2014, this experiment was continued with a better control of the systematic uncertainties, with better suppression of coincident and random background, improved particle identification, and with higher luminosities. Another key point of the progress was the improvement in the absolute momentum calibration of the magnetic spectrometers.

  8. 4H-SiC detectors for ultraviolet light monitoring

    NASA Astrophysics Data System (ADS)

    Mazzillo, M.; Sciuto, A.; Badalà, P.; Carbone, B.; Russo, A.; Coffa, S.

    2015-02-01

    Silicon Carbide (SiC) provides the unique property of near-perfect visible blindness and very high signal-to-noise ratio due to the high quantum efficiency and low dark current even at high temperature. These features make SiC the best available material for the manufacturing of visible blind semiconductor ultraviolet (UV) light detectors. Thanks to their properties, SiC detectors have been extensively used in fact for flame detection monitoring, UV sterilization and astronomy. Here we report on the electrical and optical performance of patterned thin metal film NiSi/4H-SiC vertical Schottky photodiodes with different semiconductor exposed area suitably designed for UV light monitoring.

  9. Extended defects in 4H-silicon carbide homoepitaxial layers

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan

    The purpose of this thesis is to study the structure of extended defects in 4H-SIC homoepitaxial layers, and to identify their nucleation mechanisms. Characteristics of basal plane dislocations in 4H-SiC epilayers were investigated in a comprehensive manner, including their morphologies, Burgers' vectors, positions, and correlation with the extended defects propagating from the substrate. Plan-view transmission x-ray topography was the major characterization technique used in this study. Complementary data was obtained by KOH etching and optical microscopy. Trace of glide was detected on every basal plane dislocation in the entire 3-inch epilayer. In the center area of the epi-wafer, the glide can extend to macroscopic distance and form edge-type dislocations at the epilayer/surface interface. During the motion, dislocation half loop arrays were found to nucleate at the growth front. The magnitude of the resolved shear stress was estimated based on the radius of curvature of the dislocation lines. It surpassed the critical resolved shear stress at the epitaxial growth temperature. The stress was identified to be compressive in the epilayer. Its origin was studied. Nitrogen-doping-difference-induced misfit strain was excluded as the source of the stress. The structures of two morphological defects, 'carrots' and 'arrows', were studied. Cross-section x-ray topography was used to image the structure of carrot defect in whole. The defect was found to nucleate at the epilayer/substrate interface on a threading screw dislocation propagating from the substrate. Its structure was mainly composed of a prismatic stacking fault and a Frank-type basal plane stacking fault. The arrow defect was found to be produced by a spheroid shape inclusion in the volume of the epilayer. Zone axis diffraction pattern under transmission electron microscope identified the nature of the inclusion as 3C-SIC. It was determined to nucleate at the substrate surface contaminations.

  10. Patch Size and Isolation Predict Plant Species Density in a Naturally Fragmented Forest

    PubMed Central

    Munguía-Rosas, Miguel A.; Montiel, Salvador

    2014-01-01

    Studies of the effects of patch size and isolation on plant species density have yielded contrasting results. However, much of the available evidence comes from relatively recent anthropogenic forest fragments which have not reached equilibrium between extinction and immigration. This is a critical issue because the theory clearly states that only when equilibrium has been reached can the number of species be accurately predicted by habitat size and isolation. Therefore, species density could be better predicted by patch size and isolation in an ecosystem that has been fragmented for a very long time. We tested whether patch area, isolation and other spatial variables explain variation among forest patches in plant species density in an ecosystem where the forest has been naturally fragmented for long periods of time on a geological scale. Our main predictions were that plant species density will be positively correlated with patch size, and negatively correlated with isolation (distance to the nearest patch, connectivity, and distance to the continuous forest). We surveyed the vascular flora (except lianas and epiphytes) of 19 forest patches using five belt transects (50×4 m each) per patch (area sampled per patch = 0.1 ha). As predicted, plant species density was positively associated (logarithmically) with patch size and negatively associated (linearly) with patch isolation (distance to the nearest patch). Other spatial variables such as patch elevation and perimeter, did not explain among-patch variability in plant species density. The power of patch area and isolation as predictors of plant species density was moderate (together they explain 43% of the variation), however, a larger sample size may improve the explanatory power of these variables. Patch size and isolation may be suitable predictors of long-term plant species density in terrestrial ecosystems that are naturally and anthropogenically fragmented. PMID:25347818

  11. MS lesion segmentation using a multi-channel patch-based approach with spatial consistency

    NASA Astrophysics Data System (ADS)

    Mechrez, Roey; Goldberger, Jacob; Greenspan, Hayit

    2015-03-01

    This paper presents an automatic method for segmentation of Multiple Sclerosis (MS) in Magnetic Resonance Images (MRI) of the brain. The approach is based on similarities between multi-channel patches (T1, T2 and FLAIR). An MS lesion patch database is built using training images for which the label maps are known. For each patch in the testing image, k similar patches are retrieved from the database. The matching labels for these k patches are then combined to produce an initial segmentation map for the test case. Finally a novel iterative patch-based label refinement process based on the initial segmentation map is performed to ensure spatial consistency of the detected lesions. A leave-one-out evaluation is done for each testing image in the MS lesion segmentation challenge of MICCAI 2008. Results are shown to compete with the state-of-the-art methods on the MICCAI 2008 challenge.

  12. Smart patch piezoceramic actuator issues

    NASA Technical Reports Server (NTRS)

    Griffin, Steven F.; Denoyer, Keith K.; Yost, Brad

    1993-01-01

    The Phillips Laboratory is undertaking the challenge of finding new and innovative ways to integrate sensing, actuation, and the supporting control and power electronics into a compact self-contained unit to provide vibration suppression for a host structure. This self-contained unit is commonly referred to as a smart patch. The interfaces to the smart patch will be limited to standard spacecraft power and possibly a communications line. The effort to develop a smart patch involves both contractual and inhouse programs which are currently focused on miniaturization of the electronics associated with vibrational control using piezoceramic sensors and actuators. This paper is comprised of two distinct parts. The first part examines issues associated with bonding piezoceramic actuators to a host structure. Experimental data from several specimens with varying flexural stiffness are compared to predictions from two piezoelectric/substructure coupling models, the Blocked Force Model and the Uniform Strain Model with Perfect Bonding. The second part of the paper highlights a demonstration article smart patch created using the insights gained from inhouse efforts at the Phillips Laboratory. This demonstration article has self contained electronics on the same order of size as the actuator powered by a voltage differential of approximately 32 volts. This voltage is provided by four rechargeable 8 volt batteries.

  13. Smart patch piezoceramic actuator issues

    NASA Astrophysics Data System (ADS)

    Griffin, Steven F.; Denoyer, Keith K.; Yost, Brad

    1993-02-01

    The Phillips Laboratory is undertaking the challenge of finding new and innovative ways to integrate sensing, actuation, and the supporting control and power electronics into a compact self-contained unit to provide vibration suppression for a host structure. This self-contained unit is commonly referred to as a smart patch. The interfaces to the smart patch will be limited to standard spacecraft power and possibly a communications line. The effort to develop a smart patch involves both contractual and inhouse programs which are currently focused on miniaturization of the electronics associated with vibrational control using piezoceramic sensors and actuators. This paper is comprised of two distinct parts. The first part examines issues associated with bonding piezoceramic actuators to a host structure. Experimental data from several specimens with varying flexural stiffness are compared to predictions from two piezoelectric/substructure coupling models, the Blocked Force Model and the Uniform Strain Model with Perfect Bonding. The second part of the paper highlights a demonstration article smart patch created using the insights gained from inhouse efforts at the Phillips Laboratory. This demonstration article has self contained electronics on the same order of size as the actuator powered by a voltage differential of approximately 32 volts. This voltage is provided by four rechargeable 8 volt batteries.

  14. Monocular patching may induce ipsilateral "where" spatial bias.

    PubMed

    Chen, Peii; Erdahl, Lillian; Barrett, Anna M

    2009-02-01

    Spatial bias is an asymmetry of perception and/or representation of spatial information - "where" bias -, or of spatially directed actions - "aiming" bias. A monocular patch may induce contralateral "where" spatial bias (the Sprague effect [Sprague, J. M. (1966). Interaction of cortex and superior colliculus in mediation of visually guided behavior in cat. Science, 153(3743), 1544-1547]). However, an ipsilateral patch-induced spatial bias may be observed if visual occlusion results in top-down, compensatory re-allocation of spatial perceptual or representational resources toward the region of visual deprivation. Tactile distraction from a monocular patch may also contribute to an ipsilateral bias. To examine these hypotheses, neurologically normal adults bisected horizontal lines at baseline without a patch, while wearing a monocular patch, and while wearing tactile-only and visual-only monocular occlusion. We fractionated "where" and "aiming" spatial bias components using a video apparatus to reverse visual feedback for half of the test trials. The results support monocular patch-induced ipsilateral "where" spatial errors, which are not consistent with the Sprague effect. Further, the present findings suggested that the induced ipsilateral bias may be primarily induced by visual deprivation, consistent with compensatory "where" resource re-allocation. PMID:19100274

  15. Montage of Apollo Crew Patches

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This montage depicts the flight crew patches for the manned Apollo 7 thru Apollo 17 missions. The Apollo 7 through 10 missions were basically manned test flights that paved the way for lunar landing missions. Primary objectives met included the demonstration of the Command Service Module (CSM) crew performance; crew/space vehicle/mission support facilities performance and testing during a manned CSM mission; CSM rendezvous capability; translunar injection demonstration; the first manned Apollo docking, the first Apollo Extra Vehicular Activity (EVA), performance of the first manned flight of the lunar module (LM); the CSM-LM docking in translunar trajectory, LM undocking in lunar orbit, LM staging in lunar orbit, and manned LM-CSM docking in lunar orbit. Apollo 11 through 17 were lunar landing missions with the exception of Apollo 13 which was forced to circle the moon without landing due to an onboard explosion. The craft was,however, able to return to Earth safely. Apollo 11 was the first manned lunar landing mission and performed the first lunar surface EVA. Landing site was the Sea of Tranquility. A message for mankind was delivered, the U.S. flag was planted, experiments were set up and 47 pounds of lunar surface material was collected for analysis back on Earth. Apollo 12, the 2nd manned lunar landing mission landed in the Ocean of Storms and retrieved parts of the unmanned Surveyor 3, which had landed on the Moon in April 1967. The Apollo Lunar Surface Experiments Package (ALSEP) was deployed, and 75 pounds of lunar material was gathered. Apollo 14, the 3rd lunar landing mission landed in Fra Mauro. ALSEP and other instruments were deployed, and 94 pounds of lunar materials were gathered, using a hand cart for first time to transport rocks. Apollo 15, the 4th lunar landing mission landed in the Hadley-Apennine region. With the first use of the Lunar Roving Vehicle (LRV), the crew was bale to gather 169 pounds of lunar material. Apollo 16, the 5th lunar

  16. Local spread of metamitron resistant Chenopodium album L. patches.

    PubMed

    Aper, J; De Riek, J; Mechant, E; Bulcke, R; Reheul, D

    2011-01-01

    Molecular markers can provide valuable information on the spread of resistant weed biotypes. In particular, tracing local spread of resistant weed patches will give details on the importance of seed migration with machinery, manure, wind or birds. This study investigated the local spread of metamitron resistant Chenopodium album L. patches in the southwest region of the province West-Flanders (Belgium). During the summer of 2009, leaf and seed samples were harvested in 27 patches, distributed over 10 sugar beet fields and 1 maize field. The fields were grouped in four local clusters. Each cluster corresponded with the farmer who cultivated these fields. A cleaved amplified polymorphic sequence (CAPS) procedure identified the Ser264 to Gly mutation in the D1 protein, endowing resistance to metamitron, a key herbicide applied in sugar beet. The majority of the sampled plants within a patch (97% on average) carried this mutation. Amplified fragment length polymorphism (AFLP) analysis was performed with 4 primer pairs and yielded 270 molecular markers, polymorphic for the whole dataset (303 samples). Analysis of molecular variance revealed that a significant part of the genetic variability was attributed to variation among the four farmer locations (12 %) and variation among Chenopodium album patches within the farmer locations (14%). In addition, Mantel tests revealed a positive correlation between genetic distances (linearised phipt between pairs of patches) and geographic distances (Mantel-coefficient significant at p = 0.002), suggesting isolation-by-distance. In one field, a decreased genetic diversity and strong genetic relationships between all the patches in this field supported the hypothesis of a recent introduction of resistant biotypes. Furthermore, genetic similarity between patches from different fields from the same farmer and from different farmers indicated that seed transport between neighbouring fields is likely to have an important impact on the

  17. Characterization of phosphorus implantation in 4H-SiC

    SciTech Connect

    Khemka, V.; Patel, R.; Ramungul, N.; Chow, T.P.; Ghezzo, M.; Kretchmer, J.

    1999-03-01

    Silicon carbide is expected to be a promising material for high-voltage semiconductor power devices. The authors report the characterization of phosphorus implantation in 4H-SiC. The implanted layers are characterized by analytical techniques (secondary ion mass spectrometry, transmission electron microscopy) as well as electrical and a sheet resistance value as low as 160 {Omega}/{open_square} has been measured. The authors have also studied the effect of annealing time and temperature on activation of phosphorus implants. It has been shown to be possible to obtain low sheet resistance ({approximately}260 {Omega}/{open_square}) by annealing at a temperature as low as 1,200 C. High-dose ({approximately} 4 {times} 10{sup 15} cm{sup {minus}2}) implants are found to have a higher sheet resistance than that on lower dose implants which is attributed to the near-surface depletion of the dopant during high temperature anneal. Different implantation dosages were utilized for the experiments and subsequently junction rectifiers were fabricated. Forward characteristics of these diodes are observed to obey a generalized Sah-Noyce-Shockly multiple level recombination model with four shallow levels and one deep level.

  18. 4H-SiC Schottky photodiodes for ultraviolet flame detection

    NASA Astrophysics Data System (ADS)

    Mazzillo, M.; Sciuto, A.

    2015-10-01

    In the last few years silicon carbide (SiC) has emerged as an appropriate material for the detection of very low ultraviolet photon fluxes even at elevated temperatures. In this paper we report on the electro-optical characteristics of large area interdigit Ni2Si/4H-SiC photodiodes in TO metal can package with a suitable molded cap quartz window with high transmission in the ultraviolet wavelength range. The detectors have been tested for the detection of the ultraviolet component of the yellow flame emitted by a small candle, showing good sensitivity for very weak photon fluxes notwithstanding the linear operation condition of the photodiodes.

  19. Improved Image Registration by Sparse Patch-Based Deformation Estimation

    PubMed Central

    Kim, Minjeong; Wu, Guorong; Wang, Qian; Shen, Dinggang

    2014-01-01

    Despite of intensive efforts for decades, deformable image registration is still a challenging problem due to the potential large anatomical differences across individual images, which limits the registration performance. Fortunately, this issue could be alleviated if a good initial deformation can be provided for the two images under registration, which are often termed as the moving subject and the fixed template, respectively. In this work, we present a novel patch-based initial deformation prediction framework for improving the performance of existing registration algorithms. Our main idea is to estimate the initial deformation between subject and template in a patch-wise fashion by using the sparse representation technique. We argue that two image patches should follow the same deformation towards the template image if their patch-wise appearance patterns are similar. To this end, our framework consists of two stages, i.e., the training stage and the application stage. In the training stage, we register all training images to the pre-selected template, such that the deformation of each training image with respect to the template is known. In the application stage, we apply the following four steps to efficiently calculate the initial deformation field for the new test subject: (1) We pick a small number of key points in the distinctive regions of the test subject; (2) For each key point, we extract a local patch and form a coupled appearance-deformation dictionary from training images where each dictionary atom consists of the image intensity patch as well as their respective local deformations; (3) A small set of training image patches in the coupled dictionary are selected to represent the image patch of each subject key point by sparse representation. Then, we can predict the initial deformation for each subject key point by propagating the pre-estimated deformations on the selected training patches with the same sparse representation coefficients. (4) We

  20. Synthesis and antifungal activity of 2H-1,4-benzoxazin-3(4H)-one derivatives.

    PubMed

    Śmist, Małgorzata; Kwiecień, Halina; Krawczyk, Maria

    2016-06-01

    A series of 2-alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-l) was easily synthesized by two-step process involving O-alkylation of 2-nitrophenols with methyl 2-bromoalkanoates and next "green" catalytic reductive cyclization of the obtained 2-nitro ester intermediates (3a-l). Further, 6,7-dibromo (5a-c) and N-acetyl (6) derivatives were prepared by bromination and acetylation of unsubstituted 2-alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-c). The novel compounds (3a-l, 4d-l, 5a-c and 6) were fully characterized by spectroscopic methods (MS, (1)H and (13)C NMR). 2-Alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-l, 5a-c and 6) were screened for antifungal activity. Preliminary assays were performed using two methods: in vitro against seven phytopathogenic fungi-Botrytis cinerea, Phythophtora cactorum, Rhizoctonia solani, Phoma betae, Fusarium culmorum, Fusarium oxysporum and Alternaria alternata-and in vivo against barley powdery mildew Blumeria graminis. The tested compounds displayed moderate to good antifungal activity at high concentration (200 mg L(-1)). The most potent compounds were 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a), 2-ethyl-7-fluoro-2H-1,4-benzoxazin-3(4H)-one (4g) and 4-acetyl-2-ethyl-2H-1,4-benzoxazin-3(4H)-one (6), which completely inhibited the mycelial growth of seven agricultural fungi at the concentration of 200 mg L(-1) in the in vitro tests. Moreover, 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a) and 4-acetyl-2-ethyl-2H-1,4-benzoxazin-3(4H)-one (6) were also screened for antifungal activity at concentrations of 100 mg L(-1) and 20 mg L(-1). In the concentration of 100 mg L(-1), the N-acetyl derivative (6) completely inhibited the growth of three strains of fungi (F. culmorum, P. cactorum and R. solani), while 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a) completely inhibited only R. solani strain. At the concentration of 20 mg L(-1), compound 6 showed good activity only against P. cactorum strain (72%). PMID:26963527

  1. Drift Phenomena of Forward and Reverse Recovery Characteristics in 0001 4H-SiC p-i-n Diode

    NASA Astrophysics Data System (ADS)

    Nakayama, Koji; Sugawara, Yoshitaka; Tsuchida, Hidekazu; Kimura, Chiharu; Aoki, Hidemitsu

    2011-04-01

    4H-SiC p-i-n diodes fabricated on the (0001) C-face showed smaller forward voltage drift and minimal changes in reverse recovery characteristics after a forward bias stress test compared to those observed on the (0001) Si-face. These drift phenomena in 4H-SiC p-i-n diodes could be explained by increased recombination along the perimeter of single Shockley-type stacking faults. It is suggested that the number of single Shockley-type stacking faults significantly decreased in the drift layer fabricated on (0001) C-face in comparison with that on (0001) Si-face.

  2. OpenSSO Project Patches

    2009-06-08

    These are patches to Sun Microsystems open source OpenSSO project to fix various bugs and incorporate changes for Sandia and NNSA to use the product including fixes to improve OpenSSO's authentication and authorization abilities. These fixes will then by incorporated by Sun into their Sun Access Manager product, which is used by various DOE/NNSA plants and labs. Having Sun maintain these changes will relieve SNL and DOE from the cost of maintaining the changes themselves.

  3. Foraging decisions, patch use, and seasonality in egrets (Aves: ciconiiformes)

    USGS Publications Warehouse

    Erwin, R.M.

    1985-01-01

    Feeding snowy (Egretta thula) and great (Casmerodius albus) egrets were observed during 2 breeding seasons in coastal New Jersey and 2 brief winter periods in northeast Florida (USA). A number of tests based on assumptions of foraging models, predictions from foraging theory, and earlier empirical tests concerning time allocation and movement in foraging patches was made. Few of the expectations based on foraging theory and/or assumptions were supported by the empirical evidence. Snowy egrets fed with greater intensity and efficiency during the breeding season (when young were being fed) than during winter. They also showed some tendency to leave patches when their capture rate declined, and they spent more time foraging in patches when other birds were present nearby. Great egrets showed few of these tendencies, although they did leave patches when their intercapture intervals increased. Satiation differences had some influence on feeding rates in snowy egrets, but only at the end of feeding bouts. Some individuals of both species revisited areas in patches that had recently been exploited, and success rates were usually higher after the 2nd visit. Apparently, for predators of active prey, short-term changes in resource availability ('resource depression') may be more important than resource depletion, a common assumption in most optimal foraging theory models.

  4. 7 CFR 8.9 - Use in 4-H fund raising.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Use in 4-H fund raising. 8.9 Section 8.9 Agriculture Office of the Secretary of Agriculture 4-H CLUB NAME AND EMBLEM § 8.9 Use in 4-H fund raising. (a) Fund-raising programs using the 4-H Name or Emblem may be carried out for specific educational purposes. Such fund-raising programs and use of the...

  5. Effects of Patch-Size on Populations of Intertidal Limpets, Siphonaria spp., in a Linear Landscape

    PubMed Central

    Cole, Victoria J.; Johnson, Linda G.; McQuaid, Christopher D.

    2012-01-01

    Organisms with different life-histories and abilities to disperse often utilise habitat patches in different ways. We investigated the influence of the size of patches of rock (separated by stretches of sand) on the density of pulmonate limpets (Siphonaria spp.) along 1500 km of the linear landscape of the South African coastline. We compared the influence of patch-size on two congeneric species with different modes of development, S. serrata a direct developer, and S. concinna a planktonic developer. We tested the spatial and temporal consistency of the effects of patch-size by sampling 7 independent regions spanning the distributional range of both species of limpets, and by sampling one region at monthly intervals for 1 year. Within each region or month, 4 small patches (<20 m in length) interspersed with the 4 large patches (>60 m in length) were sampled. Across the entire geographic range and throughout the year, there were more of both species of limpets in large patches than in small patches. In most regions, there was greater variability in large patches than small patches. Variability within patches in a single region was similar throughout the year, with greater variability of both species in large than in small patches. We found little influence of the mode of development on the response of limpets to patch-size. Our findings highlight the importance of understanding patterns of distribution of species with respect to habitat heterogeneity in linear landscapes, and contradict the idea that organism mobility at an early ontogenetic stage directly affects habitat use. PMID:23284875

  6. SADDLE HORSE AND OTHER LIVESTOCK ADVISORS' PERCEPTIONS OF 4-H CLUB WORK IN OHIO.

    ERIC Educational Resources Information Center

    GROVES, ROBERT H.

    PERCEPTIONS AND UNDERSTANDINGS OF 4-H OBJECTIVES AND PROGRAMS OF 4-H SADDLE HORSE ADVISORS WERE COMPARED WITH THOSE OF OTHER LIVESTOCK ADVISORS IN NORTHEASTERN AND SOUTHWESTERN DISTRICTS OF OHIO. DATA WERE COLLECTED BY QUESTIONNAIRES FROM 90 SADDLE HORSE AND 133 OTHER LIVESTOCK ADVISORS. STATE 4-H STAFF AND SUPERVISORS PROVIDED CORRECT ANSWERS.…

  7. Using the Delphi Technique to Assess Educational Needs Related to Extension's 4-H Beef Program.

    ERIC Educational Resources Information Center

    Shih, Ching-Chun; Gamon, Julia A.

    1997-01-01

    Delphi panels completing questionnaires included 32 parents of 4-H students, 16 extension beef specialists, 21 4-H field specialists, and 21 industry representatives. They identified 31 subject-matter and 30 life-skill topics useful for 4-H manuals. Emerging topics included consumer and environmental concerns. (SK)

  8. Perceptions of Missouri 4-H Youth Development Personnel Regarding Interorganizational Cooperative Behavior

    ERIC Educational Resources Information Center

    McKim, Billy R.; Torres, Robert M.

    2011-01-01

    Perceptions of 4-H youth development personnel regarding interorganizational cooperation were studied between the perceived and desired levels of cooperative activities between 4-H youth development personnel and secondary agriculture teachers. Results indicated that 4-H youth development personnel wanted higher levels of coordinated efforts…

  9. Examination of Attitude and Interest Measures for 4-H Science Evaluation

    ERIC Educational Resources Information Center

    Lewis, Kendra M.; Worker, Steven M.

    2015-01-01

    Science education research has demonstrated the influence of affect on learning. The National 4-H Science Logic Model outlines outcomes from youth participation in 4-H science programs, which includes attitude and interest outcomes. The associated measure, the National 4-H Science Common Measure, assesses these attitude constructs and not other…

  10. Perceptions of Texas 4-H Livestock Ambassadors on Career Development, Higher Education, and Leadership Development

    ERIC Educational Resources Information Center

    Zanolini, William F.; Rayfield, John; Ripley, Jeff

    2013-01-01

    Selected 4-H youth participated in the Texas 4-H Livestock Ambassador program. Forty-five youth participated in the 3-day program delivered by university professors and staff, Texas AgriLife Extension faculty and industry representatives. An instrument was developed and administered to the Texas 4-H Livestock Ambassadors at the end of their first…

  11. Understanding the Knowledge and Use of Experiential Learning within Pennsylvania 4-H Clubs

    ERIC Educational Resources Information Center

    Bechtel, Robyn; Ewing, John C.; Threeton, Mark; Mincemoyer, Claudia

    2013-01-01

    Experiential learning is incorporated into the National 4-H curriculum. However, the state 4-H staff in Pennsylvania is unsure of the current knowledge and use of experiential learning within the local 4-H clubs. An online survey was distributed to Extension educators and volunteer leaders within Pennsylvania to assess the current knowledge and…

  12. Relationship between Participation in 4-H and Community Leadership in Rural Montana

    ERIC Educational Resources Information Center

    Flynn, Allison; Frick, Martin; Steele, Douglas

    2010-01-01

    Studies on the impact of 4-H on former members generally use alumni as one cohort. In rural states, such as Montana, it is important to understand the impact of 4-H on alumni in these rural areas and the role 4-H plays in community involvement. The study reported here sought to determine the perception of current community leaders in rural Montana…

  13. Expression analysis of kenaf cinnamate 4-hydroxylase (C4H) ortholog during developmental and stress responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to clone and analyze the expression pattern of a C4H gene encoding cinnamate 4-hydroxylase from kenaf (Hibiscus cannabinus L.). A full-length C4H ortholog was cloned using degenerate primers and the RACE (rapid amplification of cDNA ends) method. The full-length C4H ortholog...

  14. Text to Speech: A 4-H Model of Accessibility and Inclusion

    ERIC Educational Resources Information Center

    Green, Jeremy W.

    2012-01-01

    4-H project manuals play an integral part in a youth's ability to achieve mastery in a specific project area. For youth who struggle with reading, written 4-H materials prove inadequate in addressing the needs of the learner. This article proposes a new delivery method of 4-H educational material designed to create a more inclusive and…

  15. Stewardship as a Means to Create Organizational Reform: A View into Minnesota 4-H Youth Development

    ERIC Educational Resources Information Center

    Skuza, Jennifer A.; Freeman, Dorothy M.; Bremseth, Tamara J.; Doering, Shirley A.; Quinlan, Robert B.; Morreim, Patricia A.; Deidrick, James C.

    2010-01-01

    Minnesota 4-H Youth Development (MN 4-H) used stewardship as a means to create organizational reform to address the public use of the 4-H name and emblem in terms of risk management, real estate and equipment, and finances. A task force implemented a participatory process with colleagues and stakeholders to build and implement the reform effort.…

  16. The ultraviolet photochemistry of diacetylene - Direct detection of primary products of the metastable C4H2* + C4H2 reaction

    NASA Technical Reports Server (NTRS)

    Bandy, Ralph E.; Lakshminarayan, Chitra; Frost, Rex K.; Zwier, Timothy S.

    1993-01-01

    The products of diacetylene's ultraviolet photochemistry over the 245-220 nm region were directly determined in experiments where C4H2 was excited within a small reaction tube attached to a pulsed nozzle. The products formed in the collisions of C4H2* with C4H2 were subsequently ionized by vacuum UV radiation (at 118 nm) in the ion source of a time-of-flight mass spectrometer. It was found that the reaction of C4H2* with C4H2 produces C6H2 (+C2H2), C8H2 (+2H,H2), and C8H3 (+H), confirming the results of Glicker and Okabe (1987). Under certain conditions, secondary products were observed. Mechanisms for the observed reactions are proposed.

  17. Density functional studies on the endohedral complex of fullerene C70 with tetrahedrane (C4H4): C4H4@C70.

    PubMed

    Ren, Xiao-Yuan; Jiang, Cai-Ying

    2012-07-01

    B3LYP/6-31G(d) hybrid HF/DFT calculations were carried out to determine the structural and electronic properties of the endohedral complex of a C(70) cage with tetrahedrane (C(4)H(4)). It was demonstrated that the formation of the complex is endothermic, with a destabilization energy of 72.56 kcal mol(-1). C(4)H(4) is seated in the center of the C(70) cage and exists in molecular form inside the fullerene. C(4)H(4) endohedral doping slightly perturbs the molecular orbitals of C(70). The calculated HOMO-LUMO gaps, the electron affinity (EA), and the ionization potential (IP) indicate that C(4)H(4)@C(70) is more chemically reactive than C(70). The IR active modes and harmonic vibrational frequencies of C(4)H(4)@ C(70) are also discussed. PMID:22246288

  18. A large-scale deforestation experiment: Effects of patch area and isolation on Amazon birds

    USGS Publications Warehouse

    Ferraz, G.; Nichols, J.D.; Hines, J.E.; Stouffer, P.C.; Bierregaard, R.O.; Lovejoy, T.E.

    2007-01-01

    As compared with extensive contiguous areas, small isolated habitat patches lack many species. Some species disappear after isolation; others are rarely found in any small patch, regardless of isolation. We used a 13-year data set of bird captures from a large landscape-manipulation experiment in a Brazilian Amazon forest to model the extinction-colonization dynamics of 55 species and tested basic predictions of island biogeography and metapopulation theory. From our models, we derived two metrics of species vulnerability to changes in isolation and patch area. We found a strong effect of area and a variable effect of isolation on the predicted patch occupancy by birds.

  19. An Integrated Gate Driver in 4H-SiC for Power Converter Applications

    SciTech Connect

    Ericson, Milton Nance; Frank, Steven Shane; Britton, Charles; Janke, Devon D; Ezell, N Dianne Bull; Ryu, Sei_Hyung; Mantooth, Alan; Francis, Dr. Matt; Lanmichhane, Dr. Ranjan; Shepherd, Dr. Paul; Glover, Dr. Michael; Whitaker, Mr. Bret; Cole, Mr. Zach; Passmore, Mr. Brandon; Mcnutt, Tyler

    2014-01-01

    A gate driver fabricated in a 2-um 4H silicon carbide (SiC) process is presented. This process was optimized for vertical power MOSFET fabrication but accommodated integration of a few low-voltage device types including N-channel MOSFETs, resistors, and capacitors. The gate driver topology employed incorporates an input level translator, variable power connections, and separate power supply connectivity allowing selection of the output signal drive amplitude. The output stage utilizes a source follower pull-up device that is both overdriven and body source connected to improve rise time behavior. Full characterization of this design driving a SiC power MOSFET is presented including rise and fall times, propagation delays, and power consumption. All parameters were measured to elevated temperatures exceeding 300 C. Details of the custom test system hardware and software utilized for gate driver testing are also provided.

  20. Temporary patching of damaged UF{sub 6} cylinders

    SciTech Connect

    Cardenas, A.L.

    1991-12-31

    Patching techniques based on application of epoxy resins have been developed for temporarily repairing UF{sub 6} cylinders which have sustained relatively minor damage and must be safely emptied. The method is considerably faster and simpler than metallurgical weld repairs. Laboratory tests, detailed operational procedures, and case histories of experience at the Portsmouth Gaseous Diffusion Plant are described.

  1. Improving effectiveness of coke oven patching

    SciTech Connect

    Withrow, J.A.; McCollum, H.R.

    1982-01-01

    An effective patching program is essential to protect the battery against severe damage which would result from air, foul gas, and fuel gas leaks; and to keep it in operating condition for a reasonable life span. In addition to that basic purpose of patching, other areas such as heating efficiency, coke quality, and emissions performance can benefit from an effective program. Clairton Works and US Steel Research have made improvements in the patching program in several broad categories: equipment used for application of patching material, the patching material itself, and practices used in administration of the patching program. The equipment changes include a pusher machine ram-mounted roof patching unit and a new type of patching buggy for use with materials which tend to settle or cake. New materials have been formulated which develop a ceramic bond on the oven refractories and provide superior adherance. Battery Temperature Profiles, Charging Surveys, and Stack Observation Reports are used on a regular basis to identify critical areas for patching beyond those which can be identified by operating personnel on an incidental basis. This paper reviews each of these improvements in Clairton's patching program in terms of the equipment, materials, and practices per se and also discusses the results of implementing these changes.

  2. ERTS-1 anomalous dark patches

    NASA Technical Reports Server (NTRS)

    Strong, A. E. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Through combined use of imagery from ERTS-1 and NOAA-2 satellites was found that when the sun elevation exceeds 55 degrees, the ERTS-1 imagery is subject to considerable contamination by sunlight even though the actual specular point is nearly 300 nautical miles from nadir. Based on sea surface wave slope information, a wind speed of 10 knots will theoretically provide approximately 0.5 percent incident solar reflectance under observed ERTS multispectral scanner detectors. This reflectance nearly doubles under the influence of a 20 knot wind. The most pronounced effect occurs in areas of calm water where anomalous dark patches are observed. Calm water at distances from the specular point found in ERTS scenes will reflect no solar energy to the multispectral scanner, making these regions stand out as dark areas in all bands in an ocean scene otherwise comprosed by a general diffuse sunlight from rougher ocean surfaces. Anomalous dark patches in the outer parts of the glitter zones may explain the unusual appearance of some scenes.

  3. Exogenous pigment in Peyer's patches

    SciTech Connect

    Shepherd, N.A.; Crocker, P.R.; Smith, A.P.; Levison, D.A.

    1987-01-01

    Dark brown granular pigment was found consistently in macrophages in the deep aspect of adult Peyer's patches. Tissue sections from intestinal resections of 35 patients with a variety of pathologic diagnoses and of seven postmortem cases with no evidence of gastrointestinal disease were examined for the presence of this pigment. It was found in all patients over the age of 6 years (34 cases) but was not found in any children below that age (eight cases). Scanning electron microscopy with secondary and backscattered electron imaging and x-ray energy spectroscopy were performed on routine histologic sections. The pigmented macrophages contained aluminum and silicon, diffusely present throughout the cytoplasm, and numerous discrete foci of titanium. Pigment containing these same elements has also been found around dilated submucosal lymphatics, in mesenteric lymph nodes, and in some transmural inflammatory aggregates of Crohn's disease. The pigment probably is derived from the diet and actively taken up by Peyer's patches, which are able to incorporate inert particulate matter.

  4. Scale-dependent feedbacks between patch size and plant reproduction in desert grassland

    USGS Publications Warehouse

    Svejcar, Lauren N.; Bestelmeyer, Brandon T.; Duniway, Michael C.; James, Darren K.

    2015-01-01

    Theoretical models suggest that scale-dependent feedbacks between plant reproductive success and plant patch size govern transitions from highly to sparsely vegetated states in drylands, yet there is scant empirical evidence for these mechanisms. Scale-dependent feedback models suggest that an optimal patch size exists for growth and reproduction of plants and that a threshold patch organization exists below which positive feedbacks between vegetation and resources can break down, leading to critical transitions. We examined the relationship between patch size and plant reproduction using an experiment in a Chihuahuan Desert grassland. We tested the hypothesis that reproductive effort and success of a dominant grass (Bouteloua eriopoda) would vary predictably with patch size. We found that focal plants in medium-sized patches featured higher rates of grass reproductive success than when plants occupied either large patch interiors or small patches. These patterns support the existence of scale-dependent feedbacks in Chihuahuan Desert grasslands and indicate an optimal patch size for reproductive effort and success in B. eriopoda. We discuss the implications of these results for detecting ecological thresholds in desert grasslands.

  5. The reinvestigation of the kinetics of the metathesis reactions t-C4H9• + HBr (HI) → i-C4H10 + Br• (I•) and of the t-C4H9• free radical thermochemistry.

    PubMed

    Leplat, N; Rossi, M J

    2014-07-17

    A reinvestigation of the absolute rate constant of the metathesis reactions t-C4H9• + HBr → i-C4H10 + Br• (1) and t-C4H9• + HI → i-C4H10 + I• (2) was performed thanks to a recently developed apparatus consisting of a Knudsen reactor coupled to detection based on single-photon (VUV) photoionization mass spectrometry (SPIMS). It enables the generation of thermalized hydrocarbon free radicals owing to a source upstream of and external to the Knudsen reactor. The following Arrhenius expressions were obtained: k1 = 5.6(±1.4) × 10(–12) exp(−6.76(±0.94)/(RT)) and k2 = 2.0(±0.6) × 10(–11) exp(−8.48(±0.94)/(RT)) with R = 8.314 J mol(–1) K(–1) over the range 293 to 623 K. The mass balance of the reaction system based on closed shell product detection (CSPD) was checked in order to ensure the accuracy of the used reaction mechanism and as an independent check of k1 and k2. The wall-loss rate constants of the t-butyl free radical, kw(C4H9), were measured and found to be low compared with the corresponding escape rate constant, ke(C4H9), for effusion of t-C4H9• out of the Knudsen reactor. On the basis of the present results, the free radical standard heat of formation ΔfH298°(t-C4H9•) = 44.3 ± 1.7 kJ mol(–1) was obtained when combined with the kinetics of the inverse halogenation reaction taken from the literature and using S298°(t-C4H9•) = 322.2 J K(–1) mol(–1) following a “Third Law” evaluation method. The standard enthalpy for t-butyl free radical is consistent for both the bromination and iodination reactions within the stated uncertainties. PMID:24942181

  6. Electrochemical cell with a cadmium patch electrode

    SciTech Connect

    Ames, A.E.; Bloom, S.M.; Hoffman, A.; Norland, K.

    1980-01-22

    A cadmium patch laminar electrode, comprising a dispersion of particulate cadmium in a binder matrix on a conductive plastic substrate is prepared by contacting a zinc patch electrode comprising a dispersion of particulate zinc in a binder matrix on a conductive plastic substrate with an aqueous solution of a cadmium salt. The cadmium patch electrode can be used in a primary electrochemical cell such as that employing a manganese dioxide cathode and a cadmium chloride electrolyte.

  7. Multi-Mode Broadband Patch Antenna

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R. (Inventor)

    2001-01-01

    A multi-mode broad band patch antenna is provided that allows for the same aperture to be used at independent frequencies such as reception at 19 GHz and transmission at 29 GHz. Furthermore, the multi-mode broadband patch antenna provides a ferroelectric film that allows for tuning capability of the multi-mode broadband patch antenna over a relatively large tuning range. The alternative use of a semiconductor substrate permits reduced control voltages since the semiconductor functions as a counter electrode.

  8. RF MEMS reconfigurable triangular patch antenna.

    SciTech Connect

    Nordquist, Christopher Daniel; Christodoulou, Christos George; Feldner, Lucas Matthew

    2005-01-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  9. RF MEMS reconfigurable triangular patch antenna.

    SciTech Connect

    Christodoulou, Christos George; Nordquist, Christopher Daniel; Feldner, Lucas Matthew

    2005-07-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  10. Transdermal fentanyl patches in small animals.

    PubMed

    Hofmeister, Erik H; Egger, Christine M

    2004-01-01

    Fentanyl citrate is a potent opioid that can be delivered by the transdermal route in cats and dogs. Publications regarding transdermal fentanyl patches were obtained and systematically reviewed. Seven studies in cats and seven studies in dogs met the criteria for inclusion in this review. Dogs achieved effective plasma concentrations approximately 24 hours after patch application. Cats achieved effective plasma concentrations 7 hours after patch application. In dogs, transdermal fentanyl produced analgesia for up to 72 hours, except for the immediate 0- to 6-hour postoperative period. In cats, transdermal fentanyl produced analgesia equivalent to intermittent butorphanol administration for up to 72 hours following patch application. PMID:15533967

  11. Design, fabrication, and characterization of 4H-silicon carbide rectifiers for power switching applications

    NASA Astrophysics Data System (ADS)

    Sheridan, David Charles

    Silicon Carbide has received a substantial increase in research interest over the past few years as a base material system for high-frequency and high-power semiconductor devices. Of the over 1200 polytypes, 4H-SiC is the most attractive polytype for power devices due to its wide band gap (3.2eV), excellent thermal conductivity (4.9 W/cm·K), and high critical field strength (˜2 x 106 V/cm). Important for power devices, the 10x increase in critical field strength of SiC allows high voltage blocking layers to be fabricated significantly thinner than for comparable Si devices. For power rectifiers, this reduces device on-resistance, while maintaining the same high voltage blocking capability. In this work, 4H-SiC Schottky, pn, and junction barrier Schottky (JBS) rectifiers for use in high voltage switching applications have been designed, fabricated, and extensively characterized. First, a detailed review of 4H-SiC material parameters was performed and SiC models were implemented into a standard Si drift-diffusion numerical simulator. Using these models, a SiC simulation methodology was developed in order to enable predictive SiC device design. A wide variety of rectifier and edge termination designs were investigated and optimized with respect to breakdown efficiency, area consumption, resistance to interface charge, and fabrication practicality. Simulated termination methods include: field plates, floating guard rings, and a variety of junction termination extensions (JTE). Using the device simulation results, both Schottky and JBS rectifiers were fabricated with a novel self-aligned edge termination design, and fabricated with process elements developed at the Alabama Microelectronics Science and Technology Center facility. These rectifiers exhibited near-ideal forward characteristics and had blocking voltages in excess of 2.5kV. The SiC diodes were subjected to inductive switching tests, and were found to have superior reverse recovery characteristics compared

  12. Formulation and evaluation of ethylene-vinyl acetate copolymer matrix patches containing formoterol fumarate.

    PubMed

    Kakubari, Ikuhiro; Shinkai, Norihiro; Kawakami, Junji; Uruno, Akemi; Takayasu, Toshiyuki; Yamauchi, Hitoshi; Takayama, Satoshi; Takayama, Kozo

    2006-03-01

    The skin permeability and stability of formoterol fumarate (FF) in matrix patches containing l-menthol as an enhancer and N-methyl-2-pyrrolidone (NMP) as the solvent were investigated. Using a total of 28 matrix patches having a similar composition, containing ethylene-vinyl acetate (EVA) as the forming polymer and hydrogenated rosin glycerol ester (Ester Gum H) as the adhesive, the skin permeation of FF was found to increase with increasing l-menthol and NMP contents. FF in the matrix patches containing NMP in the range of 4.8-7.2% was stable, but stability decreased at higher values. With a standard matrix patch containing FF, the Cmax and AUC(0-24) values were found to be 1.93 ng/ml after 4 h percutaneous application to rats and 25.6 ng x h/ml. The bioavailability after percutaneous exposure was equivalent to 15.2% of the AUC(0-24) after intravenous administration. Percutaneous application proved efficacious with regard to control of simulated asthma at dose levels lower than those with which side effects occurred. Thus an optimized matrix patch containing FF was prepared with potential advantages for control of asthma. PMID:16508156

  13. 4-H PetPALS Juvenile Diversion Program Supports At-Risk Youth and Seniors

    ERIC Educational Resources Information Center

    Goble, Connie L.; Miller, Lucinda B.

    2014-01-01

    The 4-H PetPALS Juvenile Diversion Program provides a partnership opportunity with Extension and the juvenile court system to positively impact lives of at-risk youth. At-risk youth are taught by 4-H PetPALS adult volunteer leaders and 4-H PetPALS members to value and respect the human-animal bond, as well as to understand and empathize with…

  14. Patch voltage clamp of squid axon membrane.

    PubMed

    Fishman, H M

    1975-12-01

    A small area (patch) of the external surface of a squid axon can be "isolated" electrically from the surrounding bath by means of a pair of concentric glass pipettes. The seawater-filled inner pipette makes contact with the axon and constitutes the external access to the patch. The outer pipette is used to direct flowing sucrose solution over the area surrounding the patch of membrane underlying the inner pipette. Typically, sucrose isolated patches remain in good condition (spike amplitude greater than 90 mV) for periods of approximately one half hour. Patches of axon membrane which had previously been exposed to sucrose solution were often excitable. Membrane survival of sucrose treatment apparently arises from an outflow of ions from the axon and perhaps satellite cells into the interstitial cell space surrounding the exolemma. Estimate of the total access resistance (electrode plus series resistance) to the patch is about 100 komega (7 omega cm2). Patch capacitance ranges from 10-100 pF, which suggests areas of 10(-4) to 10(-5) cm2 and resting patch resistances of 10-100 Momega. Shunt resistance through the interstitial space exposed to sucrose solution, which isolates the patch, is typically 1-2 Momega. These parameters indicate that good potential control and response times can be achieved on a patch. Furthermore, spatial uniformity is demonstrated by measurement of an exoplasmic isopotential during voltage clamp of an axon patch. The method may be useful for other preparations in which limited membrane area is available or in special instances such as in the measurement of membrane conduction noise. PMID:1214276

  15. HotPatch Web Gateway: Statistical Analysis of Unusual Patches on Protein Surfaces

    DOE Data Explorer

    Pettit, Frank K.; Bowie, James U. [DOE-Molecular Biology Institute

    HotPatch finds unusual patches on the surface of proteins, and computes just how unusual they are (patch rareness), and how likely each patch is to be of functional importance (functional confidence (FC).) The statistical analysis is done by comparing your protein's surface against the surfaces of a large set of proteins whose functional sites are known. Optionally, HotPatch can also write a script that will display the patches on the structure, when the script is loaded into some common molecular visualization programs. HotPatch generates complete statistics (functional confidence and patch rareness) on the most significant patches on your protein. For each property you choose to analyze, you'll receive an email to which will be attached a PDB-format file in which atomic B-factors (temp. factors) are replaced by patch indices; and the PDB file's Header Remarks will give statistical scores and a PDB-format file in which atomic B-factors are replaced by the raw values of the property used for patch analysis (for example, hydrophobicity instead of hydrophobic patches). [Copied with edits from http://hotpatch.mbi.ucla.edu/

  16. Vacuum simulation and characterization for the Linac4 H- source

    NASA Astrophysics Data System (ADS)

    Pasquino, C.; Chiggiato, P.; Michet, A.; Hansen, J.; Lettry, J.

    2013-02-01

    At CERN, the 160 MeV H- Linac4 will soon replace the 50 MeV proton Linac2. In the H- source two major sources of gas are identified. The first is the pulsed injection at about 0.1 mbar in the plasma chamber. The second is the constant H2 injection up to 10-5 mbar in the LEBT for beam space charge compensation. In addition, the outgassing of materials exposed to vacuum can play an important role in contamination control and global gas balance. To evaluate the time dependent partial pressure profiles in the H- ion source and the RFQ, electrical network - vacuum analogy and test particle Monte Carlo simulation have been used. The simulation outcome indicates that the pressure requirements are in the reach of the proposed vacuum pumping system. Preliminary results show good agreement between the experimental and the simulated pressure profiles; a calibration campaign is in progress to fully benchmark the implemented calculations. Systematic outgassing rate measurements are on-going for critical components in the ion source and RFQ. Amongst them those for the Cu-coated SmCo magnet located in the vacuum system of the biased electron dump electrode, show results lower to stainless steel at room temperature.

  17. Gravity Survey of the Rye Patch KGRA, Rye Patch, Nevada

    NASA Astrophysics Data System (ADS)

    Mcdonald, M. R.; Gosnold, W. D.

    2011-12-01

    The Rye Patch Known Geothermal Resource Area (KGRA) is located in Pershing County Nevada on the west side of the Humboldt Range and east of the Rye Patch Reservoir approximately 200 km northeast of Reno, Nevada. Previous studies include an earlier gravity survey, 3-D seismic reflection, vertical seismic profiling (VSP) on a single well, 3-D seismic imaging, and a report of the integrated seismic studies. Recently, Presco Energy conducted an aeromagnetic survey and is currently in the process of applying 2-D VSP methods to target exploration and production wells at the site. These studies have indicated that geothermal fluid flow primarily occurs along faults and fractures and that two potential aquifers include a sandstone/siltstone member of the Triassic Natchez Pass Formation and a karst zone that occurs at the interface between Mesozoic limestone and Tertiary volcanics. We hypothesized that addition of a high-resolution gravity survey would better define the locations, trends, lengths, and dip angles of faults and possible solution cavity features. The gravity survey encompassed an area of approximately 78 km2 (30 mi2) within the boundary of the KGRA along with portions of 8 sections directly to the west and 8 sections directly to the east. The survey included 203 stations that were spaced at 400 m intervals. The simple Bouguer anomaly patterns were coincident with elevation, and those patterns remained after terrain corrections were performed. To remove this signal, the data were further processed using wave-length (bandpass) filtering techniques. The results of the filtering and comparison with the recent aeromagnetic survey indicate that the location and trend of major fault systems can be identified using this technique. Dip angles can be inferred by the anomaly contour gradients. By further reductions in the bandpass window, other features such as possible karst solution channels may also be recognizable. Drilling or other geophysical methods such as a

  18. Formulation, physicochemical characterization, and in vitro study of chitosan/HPMC blends-based herbal blended patches.

    PubMed

    Suksaeree, Jirapornchai; Monton, Chaowalit; Madaka, Fameera; Chusut, Tun; Saingam, Worawan; Pichayakorn, Wiwat; Boonme, Prapaporn

    2015-02-01

    The current work prepared chitosan/hydroxypropyl methylcellulose (HPMC) blends and studied the possibility of chitosan/HPMC blended patches for Zingiber cassumunar Roxb. The blended patches without/with crude Z. cassumunar oil were prepared by homogeneously mixing the 3.5% w/v of chitosan solution and 20% w/v of HPMC solution, and glycerine was used as plasticizer. Then, they were poured into Petri dish and produced the blended patches in hot air oven at 70 ± 2°C. The blended patches were tested and evaluated by the physicochemical properties: moisture uptake, swelling ratio, erosion, porosity, Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction, and photographed the surface and cross-section morphology under SEM technique. Herbal blended patches were studied by the in vitro release and skin permeation of active compound D. The blended patches could absorb the moisture and became hydrated patches that occurred during the swelling of blended patches. They were eroded and increased by the number of porous channels to pass through out for active compound D. In addition, the blended patches indicated the compatibility of the blended ingredients and homogeneous smooth and compact. The blended patches made from chitosan/HPMC blends provide a controlled release and skin permeation behavior of compound D. Thus, the blended patches could be suitably used for herbal medicine application. PMID:25233803

  19. Immunoisolation Patch System for Cellular Transplantation

    NASA Technical Reports Server (NTRS)

    Wang, Taylor G. (Inventor)

    2014-01-01

    An immunoisolation patch system, and particularly a patch system comprising multiple immunoisolation microcapsules, each encapsulating biological material such as cells for transplantation, which can be used in the prophylactic and therapeutic treatment of disease in large animals and humans without the need for immunosuppression.

  20. Transdermal patches: history, development and pharmacology

    PubMed Central

    Pastore, Michael N; Kalia, Yogeshvar N; Horstmann, Michael; Roberts, Michael S

    2015-01-01

    Transdermal patches are now widely used as cosmetic, topical and transdermal delivery systems. These patches represent a key outcome from the growth in skin science, technology and expertise developed through trial and error, clinical observation and evidence-based studies that date back to the first existing human records. This review begins with the earliest topical therapies and traces topical delivery to the present-day transdermal patches, describing along the way the initial trials, devices and drug delivery systems that underpin current transdermal patches and their actives. This is followed by consideration of the evolution in the various patch designs and their limitations as well as requirements for actives to be used for transdermal delivery. The properties of and issues associated with the use of currently marketed products, such as variability, safety and regulatory aspects, are then described. The review concludes by examining future prospects for transdermal patches and drug delivery systems, such as the combination of active delivery systems with patches, minimally invasive microneedle patches and cutaneous solutions, including metered-dose systems. PMID:25560046

  1. Bulkhead interface chassis for optical fiber patching

    NASA Astrophysics Data System (ADS)

    George, M.

    1985-06-01

    An optical fiber patch panel was designed to meet the changing needs of optical fiber communication link installations. This paper deals with the specification and construction details of the Bulkhead Interface Chassis patch panel. Included is ordering information for the commercial parts needed and shop drawings of the pieces to be machined.

  2. AB INITIO CHARACTERIZATION OF C{sup -}{sub 4}, C{sub 4}H, AND C{sub 4}H{sup -}

    SciTech Connect

    Senent, M. L.

    2010-01-10

    Using state-of-the-art theoretical methods, we investigate the stable isomers of C{sup -}{sub 4}, C{sub 4}H and C{sub 4}H{sup -}. Three of them are relevant for astrophysics and astrochemistry. These computations are performed using highly correlated ab initio methods and the aug-cc-pVXZ (X = T,Q) basis sets. In addition to the linear isomers, we predict the existence of several cyclic and branched forms for these molecules. For all the molecular species of interest here, sets of spectroscopic parameters are determined with perturbation theory, which compare quite well with experiment. For l - C{sub 4}H{sup -}(X {sup 1}SIGMA{sup +}), the quartic force field is computed at the coupled cluster level of theory. This force field is derived from full nine-dimensional potential energy surface generated close to the equilibrium geometry of this anion. Finally, we treat the thermochemistry of the hydrogen attachment and the electron attachment reactions that may lead to the formation of the C{sub 4}H{sup -} from either C{sup -}{sub 4} or C{sub 4}H.

  3. Tendon graft substitutes-rotator cuff patches.

    PubMed

    Coons, David A; Alan Barber, F

    2006-09-01

    Over the past few years, many biologic patches have been developed to augment repairs of large or complex tendon tears. These patches include both allograft and xenografts. Regardless of their origins, these products are primarily composed of purified type I collagen. Many factors should be considered when choosing an augmentation patch including tissue origin, graft processing, cross-linking, clinical experience, and physical properties. The purpose of this article is to familiarize the sports medicine community with several tendon augmentation grafts: GraftJacket (Wright Medical Technology, Arlington, TN), CuffPatch (Organogenesis, Canton, MA, licensed to Arthrotek, Warsaw, IN), Restore (Depuy, Warsaw, IN), Zimmer Collagen Repair (Permacol) patch (Tissue Science Laboratories Covington, GA, licensed to Zimmer, Warsaw, IN), TissueMend (TEI Biosciences, Boston, MA, licensed to Stryker Howmedica Osteonics, Kalamazoo, MI), OrthoADAPT (Pegasus Biologics, Irvine, CA), and BioBlanket (Kensey Nash, Exton, PA). PMID:17135966

  4. Engineered Tissue Patch for Cardiac Cell Therapy

    PubMed Central

    Zhang, Jianyi

    2015-01-01

    Opinion statement Cell therapy can be administered via injections delivered directly into the myocardium or as engineered cardiac tissue patches, which are the subject of this review. Engineered cardiac patches can be created from sheets of interconnected cells or by suspending the cells in a scaffold of material that is designed to mimic the native extracellular matrix. The sheet-based approach produces patches with well-aligned and electronically coupled cardiomyocytes, but cell-containing scaffolds are more readily vascularized by the host's circulatory system and, consequently, are currently more suitable for applications that require a thicker patch. Cell patches can also be modified for the co-delivery of peptides that may promote cell survival and activate endogenous repair mechanisms; nevertheless, techniques for controlling inflammation, limiting apoptosis, and improving vascular growth need continue to be developed to make it a therapeutic modality for patients with myocardial infarction. PMID:26122908

  5. Safe patch version 0.9 user manual

    SciTech Connect

    Kelley, M

    1999-03-01

    The SafePatch version 0.9 provides automated analysis of network-based computer systems to determine the status of security patches and distributes needed patches. SafePatch determines what patches need to be installed and what patches are installed on a system. SafePatch will distribute needed patches to the remote system for later installation. For those patches that are installed, SafePatch checks the permissions and ownership of the files referenced in the patch and reports on the attributes that differ from those recommended by the patch. SafePatch also ensures that the system software is authentic (that is, belonging to either a release of an operating system or a patch). The process SafePatch uses to authenticate the software on a system is more reliable and secure than other vendor-specific tools. SafePatch compares the remote system's files with the files from the patches to determine what is actually installed and what needs to be installed. This approach ensures accurate reporting of a system's patch status. It also allows SafePatch to identify files that do not belong to either the original system distribution (for example, Solaris 2.5) or to any patch. These unidentified files may be customized or trojan. Either way these files should be investigated further to determine their exact origin.

  6. Image Quality Assessment Based on Inter-Patch and Intra-Patch Similarity

    PubMed Central

    Zhou, Fei; Lu, Zongqing; Wang, Can; Sun, Wen; Xia, Shu-Tao; Liao, Qingmin

    2015-01-01

    In this paper, we propose a full-reference (FR) image quality assessment (IQA) scheme, which evaluates image fidelity from two aspects: the inter-patch similarity and the intra-patch similarity. The scheme is performed in a patch-wise fashion so that a quality map can be obtained. On one hand, we investigate the disparity between one image patch and its adjacent ones. This disparity is visually described by an inter-patch feature, where the hybrid effect of luminance masking and contrast masking is taken into account. The inter-patch similarity is further measured by modifying the normalized correlation coefficient (NCC). On the other hand, we also attach importance to the impact of image contents within one patch on the IQA problem. For the intra-patch feature, we consider image curvature as an important complement of image gradient. According to local image contents, the intra-patch similarity is measured by adaptively comparing image curvature and gradient. Besides, a nonlinear integration of the inter-patch and intra-patch similarity is presented to obtain an overall score of image quality. The experiments conducted on six publicly available image databases show that our scheme achieves better performance in comparison with several state-of-the-art schemes. PMID:25793282

  7. Reconfigurable Wideband Circularly Polarized Microstrip Patch Antenna for Wireless Applications

    NASA Astrophysics Data System (ADS)

    Khidre, Ahmed

    vice versa, with the aid of two RF PIN diodes that act as RF switches. The proposed structure which is simple; consists of a single-layer single fed radiating E-shaped patch and RF switch placed on each of its slots at an appropriate location. The design targets WLAN IEEE 802.11b/g frequency band (2.4- 2.5 GHz) as one example of the wireless applications. The idea is based on the first proposed design. In other words, if one of the switches is ON and the other is OFF, the two slot lengths will become effectively unequal and circular polarization will be obtained. If the states of the two switches are reversed, circular polarization with opposite orientation will be obtained at the same frequency band. Full-wave simulator Ansoft HFSS is again used for the analysis. Complete detailed DC biasing circuit of the switches for integration with the antenna is presented. Also, characterizations of the microwave components used in the biasing circuit are discussed. Antenna prototype has been fabricated and tested. Simulation results along with the measured one, for the reflection coefficient, axial ratio, radiation pattern, and antenna gain agree well, showing wide bandwidth and high gain for the two circularly polarized modes.

  8. 4-H's Influence on Advanced Training, Careers and Leadership Roles in Adulthood.

    ERIC Educational Resources Information Center

    Rockwell, S. Kay; And Others

    A study explored how adults felt their 4-H experience contributed to their selection of advanced education and/or a career and helped them with leadership skills in their occupations or community activities. To obtain data, a questionnaire was mailed to former 4-H members aged 25 to 35 in northeast Nebraska; 318 questionnaires were returned.…

  9. Bringing Carnaval Drum and Dance Traditions into 4-H Programming for Latino Youth

    ERIC Educational Resources Information Center

    Conklin-Ginop, Evelyn; Braverman, Marc T.; Caruso, Robyn; Bone, Dennis

    2011-01-01

    4-H Bloco Drum and Dance is an afterschool program that teaches adolescents drumming, dancing, and theater arts in the rich traditions of Brazilian Carnaval. Teens learn to express themselves in a variety of modalities and perform at community events. The program was developed by a community coalition that included 4-H, other youth programs, and…

  10. The First Fifty Years of the 4-H Program (Part 1).

    ERIC Educational Resources Information Center

    Van Horn, Beth E.; Flanagan, Constance A.; Thomson, Joan S.

    1998-01-01

    Reviews achievements during the first 50 years of 4-H club work, including volunteer leadership development, funding support, and response to society's needs during the war years. Demonstrates how 4-H has changed to meet societal needs while remaining true to the original mission. (SK)

  11. Birds in Your Backyard. 4-H Leaders Guide. L-5-17.

    ERIC Educational Resources Information Center

    Hawkes, Janet E.; Held Phillips, Diane

    This pocket folder of instructional materials is designed to introduce youth aged 9 to 12 to ornithology, the study of birds. The package includes a 4-H member's guide and a Leader's guide. The illustrated 4-H member's guide contains information about attracting and feeding birds. It also includes activities for cooking for birds, making bird…

  12. 4-H Healthy Living Programs with Impact: A National Environmental Scan

    ERIC Educational Resources Information Center

    Downey, Laura H.; Peterson, Donna J.; LeMenestrel, Suzanne; Leatherman, JoAnne; Lang, James

    2014-01-01

    The 4-H youth development program of the nation's 109 land-grant universities and the Cooperative Extension System is one of the largest youth development organization in the United States serving approximately six million youth. The 4-H Healthy Living initiative began in 2008 to promote achievement of optimal physical, social, and emotional…

  13. College Transition Study Shows 4-H Helps Youth Prepare for and Succeed in College

    ERIC Educational Resources Information Center

    Ratkos, Judy; Knollenberg, Lauren

    2015-01-01

    Many young adults enter college without the knowledge and skills necessary to succeed. The purpose of the study reported here was to determine if 4-H helps develop life skills needed for the transition to college and overall college success. An online survey was sent to college-attending 4-H alumni and a comparison group, with a final sample size…

  14. The Effects of Age, Gender, and 4-H Involvement on Life Skill Development

    ERIC Educational Resources Information Center

    Haas, Bruce E.; Mincemoyer, Claudia C.; Perkins, Daniel F.

    2015-01-01

    The study reported here examined the effects of age, gender, and 4-H involvement in clubs on life skill development of youth ages eight to 18 over a 12-month period. Regression analyses found age, gender, and 4-H involvement significantly influenced life skill development. Results found that females have higher levels of competencies in life…

  15. Acquisition, Custody, and Storage of Firearms Used in 4-H Shooting Sports Programs

    ERIC Educational Resources Information Center

    White, David J.; Smith, Jedediah D.

    2014-01-01

    Shooting sports has been a 4-H program offering since the 1930's. Tragic events related to the use of firearms as weapons have caused public and private entities to evaluate and consider the appropriateness of youth access to and usage of firearms. 4-H educators have the primary responsibility for managing the risk associated with shooting…

  16. Characteristics and Perceptions of 4-H Participants: Gender and Age Differences across Adolescence

    ERIC Educational Resources Information Center

    Bartoszuk, Karin; Randall, Brandy A.

    2011-01-01

    The study reported here examined 367 adolescent 4-H participants in terms of demographic, psychological, behavioral, and relational characteristics, as well as their perceptions and experiences in 4-H. Overall, participants scored high on all outcome variables except having a diverse population in their club. Older participants were more…

  17. Food Challenge: Serving Up 4-H to Non-Traditional Audiences

    ERIC Educational Resources Information Center

    Dodd, Sara; Follmer-Reece, Holly E.; Kostina-Ritchey, Erin; Reyna, Roxanna

    2015-01-01

    This article describes a novel approach for introducing 4-H to non-traditional/diverse audiences using 4-H Food Challenge. Set in a low SES and minority-serving rural school, Food Challenge was presented during the school day to all 7th grade students, with almost half voluntarily participating in an after-school club component. Program design…

  18. 4-H Youth Development: The Past, the Present, and the Future

    ERIC Educational Resources Information Center

    Borden, Lynne M.; Perkins, Daniel F.; Hawkey, Kyle

    2014-01-01

    The 4-H Program within Cooperative Extension is more than 100 years old. As we celebrate 100 years of Cooperative Extension, the foundation built by the 4-H Program serves as grounds to meet the needs of today's youth. The diversity of the youth who participate continues to grow, families continue to become less traditional, potential…

  19. Global 4-H Network: Laying the Groundwork for Global Extension Opportunities

    ERIC Educational Resources Information Center

    Major, Jennifer; Miller, Rhonda

    2012-01-01

    A descriptive study examining 4-H programs in Africa, Asia, and Europe was conducted to provide understanding and direction in the establishment of a Global 4-H Network. Information regarding structure, organizational support, funding, and programming areas was gathered. Programs varied greatly by country, and many partnered with other 4-H…

  20. 4-H and Tech Ed Partnership Gets Students Geeked about STEM

    ERIC Educational Resources Information Center

    Ivey, Debra; Quam, Greg

    2009-01-01

    This article discusses the 4-H Gateway Academies specifically designed to enhance science, technology, engineering, and math (STEM) skills and knowledge in middle school youth. The innovative summer day camps partnered Project Lead the Way--trained teachers with county 4-H staff from University of Wisconsin-Extension (UW-Extension) Cooperative…

  1. Fitting the Framework: The STEM Institute and the 4-H Essential Elements

    ERIC Educational Resources Information Center

    Sallee, Jeff; Peek, Gina G.

    2014-01-01

    Extension and 4-H youth development programs are addressing a shortage of scientists, engineers, and other related professionals by promoting science, technology, engineering, and math (STEM). This case study illustrates how the Oklahoma 4-H Youth Development program trained youth-adult teams to design and implement STEM projects. The STEM…

  2. 4-H and Forestry Afterschool Clubs: A Collaboration to Foster Stewardship Attitudes and Behaviors in Youth

    ERIC Educational Resources Information Center

    Gupta, Angela S.; Grant, Samantha; Strauss, Andrea Lorek

    2012-01-01

    The University of Minnesota Extension's 4-H and Forestry Afterschool program combined the 4-H structure and various forestry curricula to foster positive attitudes towards the environment and stewardship-related behaviors as these may serve as precursors to later choices that benefit the environment. Evaluation of third through fifth grade…

  3. Relative abundance of mesopredators and size of oak patches in the cross-timbers ecoregion

    USGS Publications Warehouse

    Disney, M.R.; Hellgren, E.C.; Davis, C.A.; Leslie, David M., Jr.; Engle, David M.

    2008-01-01

    Mesopredators (e.g., raccoon Procyon lotor, Virginia opossum Didelphis virginiana, striped skunk Mephitis mephitis) have received considerable attention because of links to population declines in birds via increased nest predation, especially in landscapes fragmented by anthropogenic forces. Relationships of abundance of mesopredators to size of habitat patches have received less attention than relationships to other metrics of fragmentation, particularly edge characteristics. We tested the hypothesis that relative abundance of mesopredators (e.g., raccoons and Virginia opossums) was related negatively to size of forest patch. We delineated 15 patches of oak (Quercus) forest ranging from 0.2 to 55.3 ha within a grassland-woodland mosaic in the cross-timbers ecoregion of Oklahoma. Scent stations and live traps within these patches were used to index relative abundance of mesopredators in summers 2003 and 2004. Both indices of relative abundance were related weakly and negatively to area of forest patch. However, rate of capture and visitation to scent station were not correlated consistently throughout the study. Our results suggested that the two methods to index abundance provided separate information on functional and numerical responses to size of patch. Our evidence that mesopredators within the cross timbers were more likely to be in smaller patches of oak forest may have implications to success of avian nesting in these patches.

  4. A procedure of landscape services assessment based on mosaics of patches and boundaries.

    PubMed

    Martín de Agar, Pilar; Ortega, Marta; de Pablo, Carlos L

    2016-09-15

    We develop a procedure for assessing the environmental value of landscape mosaics that simultaneously considers the values of land use patches and the values of the boundaries between them. These boundaries indicate the ecological interactions between the patches. A landscape mosaic is defined as a set of patches and the boundaries between them and corresponds to a spatial pattern of ecological interactions. The procedure is performed in two steps: (i) an environmental assessment of land use patches by means of a function that integrates values based on the goods and services the patches provide, and (ii) an environmental valuation of mosaics using a function that integrates the environmental values of their patches and the types and frequencies of the boundaries between them. This procedure allows us to measure how changes in land uses or in their spatial arrangement cause variations in the environmental value of landscape mosaics and therefore in that of the whole landscape. The procedure was tested in the Sierra Norte of Madrid (central Spain). The results show that the environmental values of the landscape depend not only on the land use patches but also on the values associated with the pattern of the boundaries within the mosaics. The results also highlight the importance of the boundaries between land use patches as determinants of the goods and services provided by the landscape. PMID:27233047

  5. Developing a nicotine patch adherence intervention for HIV-positive Latino smokers.

    PubMed

    Shadel, William G; Galvan, Frank H; Tucker, Joan S

    2016-08-01

    This paper describes two phases of formative research that had the goal of developing a treatment designed to improve adherence with the nicotine patch in HIV-positive Latino smokers. Each research phase (Phase I and II) was conducted independent of the other and used different qualitative methods to inform the development of the intervention. Phase I interviewed n=14 smokers who had previous experience using the nicotine patch to gain detailed understanding of how, when, and why they used it; their perceived barriers to using it; and their perspective on ways to improve adherence to it. Phase II provided n=35 smokers with brief smoking cessation treatment and nicotine patches, then interviewed them in "near real time" over a two month period about their use of the patch during a quit attempt (e.g., perceived barriers and facilitators). Authors of the paper extracted relevant themes emerging from the interview transcripts across the two phases. Results indicated that consistent use of the nicotine patch was associated with maintaining high motivation for use (i.e., not necessarily motivation to quit, but motivation to continue patch use); linking its use with established daily routines (e.g., with taking other medications, with brushing teeth); and maintaining realistic expectations for patch efficacy (e.g., that users may still experience some level of craving and/or withdrawal). This information will used to develop and pilot test a brief treatment module that focuses on improving nicotine patch adherence. PMID:27070097

  6. Group-Living Herbivores Weigh Up Food Availability and Dominance Status when Making Patch-Joining Decisions

    PubMed Central

    Stears, Keenan; Kerley, Graham I. H.; Shrader, Adrian M.

    2014-01-01

    Two key factors that influence the foraging behaviour of group-living herbivores are food availability and individual dominance status. Yet, how the combination of these factors influences the patch-joining decisions of individuals foraging within groups has scarcely been explored. To address this, we focused on the patch-joining decisions of group-living domestic goats (Capra hircus). When individuals were tested against the top four ranked goats of the herd, we found that at patches with low food availability they avoided these dominant patch-holders and only joined subordinates (i.e. costs outweighed benefits). However, as the amount of food increased, the avoidance of the top ranked individuals declined. Specifically, goats shifted and joined the patch of an individual one dominance rank higher than the previous dominant patch holder when the initial quantity of food in the new patch was twice that of the lower ranking individual’s patch (i.e. benefits outweighed costs). In contrast, when individuals chose between patches held by dominant goats, other than the top four ranked goats, and subordinate individuals, we found that they equally joined the dominant and subordinate patch-holders. This joining was irrespective of the dominance gap, absolute rank of the dominant patch-holder, sex or food availability (i.e. benefits outweighed costs). Ultimately, our results highlight that herbivores weigh up the costs and benefits of both food availability and patch-holder dominance status when making patch-joining decisions. Furthermore, as the initial quantity of food increases, food availability becomes more important than dominance with regard to influencing patch-joining decisions. PMID:25271889

  7. Effects of Spatial Patch Arrangement and Scale of Covarying Resources on Growth and Intraspecific Competition of a Clonal Plant

    PubMed Central

    Wang, Yong-Jian; Shi, Xue-Ping; Meng, Xue-Feng; Wu, Xiao-Jing; Luo, Fang-Li; Yu, Fei-Hai

    2016-01-01

    Spatial heterogeneity in two co-variable resources such as light and water availability is common and can affect the growth of clonal plants. Several studies have tested effects of spatial heterogeneity in the supply of a single resource on competitive interactions of plants, but none has examined those of heterogeneous distribution of two co-variable resources. In a greenhouse experiment, we grew one (without intraspecific competition) or nine isolated ramets (with competition) of a rhizomatous herb Iris japonica under a homogeneous environment and four heterogeneous environments differing in patch arrangement (reciprocal and parallel patchiness of light and soil water) and patch scale (large and small patches of light and water). Intraspecific competition significantly decreased the growth of I. japonica, but at the whole container level there were no significant interaction effects of competition by spatial heterogeneity or significant effect of heterogeneity on competitive intensity. Irrespective of competition, the growth of I. japonica in the high and the low water patches did not differ significantly in the homogeneous treatments, but it was significantly larger in the high than in the low water patches in the heterogeneous treatments with large patches. For the heterogeneous treatments with small patches, the growth of I. japonica was significantly larger in the high than in the low water patches in the presence of competition, but such an effect was not significant in the absence of competition. Furthermore, patch arrangement and patch scale significantly affected competitive intensity at the patch level. Therefore, spatial heterogeneity in light and water supply can alter intraspecific competition at the patch level and such effects depend on patch arrangement and patch scale. PMID:27375630

  8. Effects of Spatial Patch Arrangement and Scale of Covarying Resources on Growth and Intraspecific Competition of a Clonal Plant.

    PubMed

    Wang, Yong-Jian; Shi, Xue-Ping; Meng, Xue-Feng; Wu, Xiao-Jing; Luo, Fang-Li; Yu, Fei-Hai

    2016-01-01

    Spatial heterogeneity in two co-variable resources such as light and water availability is common and can affect the growth of clonal plants. Several studies have tested effects of spatial heterogeneity in the supply of a single resource on competitive interactions of plants, but none has examined those of heterogeneous distribution of two co-variable resources. In a greenhouse experiment, we grew one (without intraspecific competition) or nine isolated ramets (with competition) of a rhizomatous herb Iris japonica under a homogeneous environment and four heterogeneous environments differing in patch arrangement (reciprocal and parallel patchiness of light and soil water) and patch scale (large and small patches of light and water). Intraspecific competition significantly decreased the growth of I. japonica, but at the whole container level there were no significant interaction effects of competition by spatial heterogeneity or significant effect of heterogeneity on competitive intensity. Irrespective of competition, the growth of I. japonica in the high and the low water patches did not differ significantly in the homogeneous treatments, but it was significantly larger in the high than in the low water patches in the heterogeneous treatments with large patches. For the heterogeneous treatments with small patches, the growth of I. japonica was significantly larger in the high than in the low water patches in the presence of competition, but such an effect was not significant in the absence of competition. Furthermore, patch arrangement and patch scale significantly affected competitive intensity at the patch level. Therefore, spatial heterogeneity in light and water supply can alter intraspecific competition at the patch level and such effects depend on patch arrangement and patch scale. PMID:27375630

  9. Simple method for the growth of 4H silicon carbide on silicon substrate

    NASA Astrophysics Data System (ADS)

    Asghar, M.; Shahid, M. Y.; Iqbal, F.; Fatima, K.; Nawaz, Muhammad Asif; Arbi, H. M.; Tsu, R.

    2016-03-01

    In this study we report thermal evaporation technique as a simple method for the growth of 4H silicon carbide on p-type silicon substrate. A mixture of Si and C60 powder of high purity (99.99%) was evaporated from molybdenum boat. The as grown film was characterized by XRD, FTIR, UV-Vis Spectrophotometer and Hall Measurements. The XRD pattern displayed four peaks at 2Θ angles 28.550, 32.700, 36.100 and 58.900 related to Si (1 1 1), 4H-SiC (1 0 0), 4H-SiC (1 1 1) and 4H-SiC (2 2 2), respectively. FTIR, UV-Vis spectrophotometer and electrical properties further strengthened the 4H-SiC growth.

  10. Tertiary amine-catalyzed (4 + 2) annulations of δ-acetoxy allenoates: synthesis of multisubstituted 4H-pyran and 4H-chromene.

    PubMed

    Gu, Yiting; Li, Falin; Hu, Pengfei; Liao, Daohua; Tong, Xiaofeng

    2015-03-01

    The DABCO-catalyzed divergent (4 + 2) annulations of δ-acetoxy allenoates 1 are reported. The chemical behavior of 1 under DABCO catalyst was found to be substrate dependent. Allenoate 1 with an aromatic group at δC preferentially reacted with salicylaldehyde derivative 2, delivering 4H-chromenes 3. On the other hand, allenoates 1 with an alkyl group at δC readily underwent (4 + 2) annulations with oxo diene 4 to afford 4H-pyrans 5. PMID:25692476

  11. Ultra high voltage MOS controlled 4H-SiC power switching devices

    NASA Astrophysics Data System (ADS)

    Ryu, S.; Capell, C.; Van Brunt, E.; Jonas, C.; O'Loughlin, M.; Clayton, J.; Lam, K.; Pala, V.; Hull, B.; Lemma, Y.; Lichtenwalner, D.; Zhang, Q. J.; Richmond, J.; Butler, P.; Grider, D.; Casady, J.; Allen, S.; Palmour, J.; Hinojosa, M.; Tipton, C. W.; Scozzie, C.

    2015-08-01

    Ultra high voltage (UHV, >15 kV) 4H-silicon carbide (SiC) power devices have the potential to significantly improve the system performance, reliability, and cost of energy conversion systems by providing reduced part count, simplified circuit topology, and reduced switching losses. In this paper, we compare the two MOS based UHV 4H-SiC power switching devices; 15 kV 4H-SiC MOSFETs and 15 kV 4H-SiC n-IGBTs. The 15 kV 4H-SiC MOSFET shows a specific on-resistance of 204 mΩ cm2 at 25 °C, which increased to 570 mΩ cm2 at 150 °C. The 15 kV 4H-SiC MOSFET provides low, temperature-independent, switching losses which makes the device more attractive for applications that require higher switching frequencies. The 15 kV 4H-SiC n-IGBT shows a significantly lower forward voltage drop (VF), along with reasonable switching performance, which make it a very attractive device for high voltage applications with lower switching frequency requirements. An electrothermal analysis showed that the 15 kV 4H-SiC n-IGBT outperforms the 15 kV 4H-SiC MOSFET for applications with switching frequencies of less than 5 kHz. It was also shown that the use of a carrier storage layer (CSL) can significantly improve the conduction performance of the 15 kV 4H-SiC n-IGBTs.

  12. Patch shape, connectivity, and foraging by oldfield mice (Peromyscus polionotus).

    SciTech Connect

    Orrock, John, L.; Danielson, Brent J

    2005-06-01

    We examined how corridors and patch shape affect foraging by the oldfield mouse (Peromyscus polionotus) by deploying foraging trays and live traps in experimental landscapes with 3 different patch types: patches connected with a corridor, unconnected patches with projecting corridorlike portions (winged patches), and unconnected rectangular patches. Corridors did not lead to different levels of activity of P. polionotus among the 3 patch types. Rather, corridors influenced activity by changing patch shape: foraging in seed trays and total number of captures of P. polionotus tended to be greater at the patch center than at the patch edge, but only in connected and winged patches where corridors or wings increased the amount of patch edge relative to the amount of core habitat in the patch. P. polionotus avoided open microhabitats near the patch edge in winged and connected patches, but not open microhabitats near the patch interior, suggesting that predation risk caused shifts in foraging near edges in connected and winged patches. Foraging in corridors and wings was generally low, suggesting that both are high-risk habitats where predation risk is not ameliorated by proximity to vegetative cover. By changing patch shape, corridors caused changes in within-patch activity of P. polionotus, changing foraging patterns and potentially altering the dynamics of P. polionotus and the seeds they consume.

  13. Oracle Applications Patch Administration Tool (PAT) Beta Version

    2002-01-04

    PAT is a Patch Administration Tool that provides analysis, tracking, and management of Oracle Application patches. This includes capabilities as outlined below: Patch Analysis & Management Tool Outline of capabilities: Administration Patch Data Maintenance -- track Oracle Application patches applied to what database instance & machine Patch Analysis capture text files (readme.txt and driver files) form comparison detail report comparison detail PL/SQL package comparison detail SQL scripts detail JSP module comparison detail Parse and loadmore » the current applptch.txt (10.7) or load patch data from Oracle Application database patch tables (11i) Display Analysis -- Compare patch to be applied with current Oracle Application installed Appl_top code versions Patch Detail Module comparison detail Analyze and display one Oracle Application module patch. Patch Management -- automatic queue and execution of patches Administration Parameter maintenance -- setting for directory structure of Oracle Application appl_top Validation data maintenance -- machine names and instances to patch Operation Patch Data Maintenance Schedule a patch (queue for later execution) Run a patch (queue for immediate execution) Review the patch logs Patch Management Reports« less

  14. Oracle Applications Patch Administration Tool (PAT) Beta Version

    SciTech Connect

    2002-01-04

    PAT is a Patch Administration Tool that provides analysis, tracking, and management of Oracle Application patches. This includes capabilities as outlined below: Patch Analysis & Management Tool Outline of capabilities: Administration Patch Data Maintenance -- track Oracle Application patches applied to what database instance & machine Patch Analysis capture text files (readme.txt and driver files) form comparison detail report comparison detail PL/SQL package comparison detail SQL scripts detail JSP module comparison detail Parse and load the current applptch.txt (10.7) or load patch data from Oracle Application database patch tables (11i) Display Analysis -- Compare patch to be applied with current Oracle Application installed Appl_top code versions Patch Detail Module comparison detail Analyze and display one Oracle Application module patch. Patch Management -- automatic queue and execution of patches Administration Parameter maintenance -- setting for directory structure of Oracle Application appl_top Validation data maintenance -- machine names and instances to patch Operation Patch Data Maintenance Schedule a patch (queue for later execution) Run a patch (queue for immediate execution) Review the patch logs Patch Management Reports

  15. Reliability of piezoceramic patch sensors under cyclic mechanical loading

    NASA Astrophysics Data System (ADS)

    Thielicke, Bärbel; Gesang, Thomas; Wierach, Peter

    2003-12-01

    Piezoceramic patch sensors have to withstand the primary stresses and strains of a structure during operation. In the leading project 'Adaptronics' a lifespan of 106 cycles at 0.1% strain was required for sensors applied on components of steel and carbon fibre reinforced plastic (CFRP). In order to test the reliability of the patches themselves and of their adhesion on the substrate, special four-point bending tests were carried out under quasistatic loading and under cyclic loading at different strain levels. The specimens consisted in sheets of steel and CFRP as substrates on which the newly developed patches with embedded piezoelectric foils and fibres were glued. In the quasistatic bending tests the performance of each sensor was characterized by measuring the sensor signal (charge) as a function of strain before and after cycling. Damage of the specimens would result in a decreasing slope of the charge-strain-curve after cycling. However, all the specimens tested survived 107 cycles up to 0.12% strain without marked loss of performance.

  16. Disorganized Cortical Patches Suggest Prenatal Origin of Autism

    MedlinePlus

    ... brain tissue revealed patch-like areas of disorganized neurons. Arrows show a patch of decreased or absent ... autistic brain is speckled with patches of abnormal neurons, according to research partially funded by the National ...

  17. Deformation of vortex patches by boundaries

    NASA Astrophysics Data System (ADS)

    Crosby, A.; Johnson, E. R.; Morrison, P. J.

    2013-02-01

    The deformation of two-dimensional vortex patches in the vicinity of fluid boundaries is investigated. The presence of a boundary causes an initially circular patch of uniform vorticity to deform. Sufficiently far away from the boundary, the deformed shape is well approximated by an ellipse. This leading order elliptical deformation is investigated via the elliptic moment model of Melander, Zabusky, and Styczek [J. Fluid Mech. 167, 95 (1986), 10.1017/S0022112086002744]. When the boundary is straight, the centre of the elliptic patch remains at a constant distance from the boundary, and the motion is integrable. Furthermore, since the straining flow acting on the patch is constant in time, the problem is that of an elliptic vortex patch in constant strain, which was analysed by Kida [J. Phys. Soc. Jpn. 50, 3517 (1981), 10.1143/JPSJ.50.3517]. For more complicated boundary shapes, such as a square corner, the motion is no longer integrable. Instead, there is an adiabatic invariant for the motion. This adiabatic invariant arises due to the separation in times scales between the relatively rapid time scale associated with the rotation of the patch and the slower time scale associated with the self-advection of the patch along the boundary. The interaction of a vortex patch with a circular island is also considered. Without a background flow, the conservation of angular impulse implies that the motion is again integrable. The addition of an irrotational flow past the island can drive the patch towards the boundary, leading to the possibility of large deformations and breakup.

  18. A smart composite patch for the repair of aircraft structures

    NASA Astrophysics Data System (ADS)

    Wakha, Kelah; Samuel, Paul; Pines, Darryll J.

    2005-05-01

    Recent interest in bonded composite patch repair technology for aerospace systems is because this method can be carried out at a reduced cost and time and can easily be applied to complex geometric structures. This paper details the development of a dual stiffness/energy sensor for monitoring the integrity of a composite patch used to repair an aluminum structural component. The smart sensor has the ability to predict the elastic field of a given host structure based on the strain state of two sub-sensors integrated into the structure. The present study shows the possibility of using the sensor to deduce the local instantaneous host stiffness. Damaged structures are characterized by a reduction in their elastic stiffness that evolve from microstructural defects. A local smart sensor can be developed to sense the local average properties on a host. In this paper, sensors are attached to a structure and a modified Eshelby's equivalent inclusion method is used to derive the elastic properties of the host. An analytical derivation and a sensitivity analysis for the quasistatic application is given in a papers by Majed, Dasgupta, Kelah and Pines. A summary of the derivation of the dynamic Eshelby tensor is presented. This is of importance because damage detection in structures undergoing vibratory and other motions present a greater challenge than those in quasistatic motion. An in-situ health monitoring active sensor system for a real structure (an aluminum plate with an attached repair patch) under close-to real lifecycle loading conditions is developed. The detection of the onset of any damage to the structure as well as the repair patch and the subsequent monitoring of the growth of this damage constitute important goals of the system. Both experimental and finite element methods were applied. Experimental results are presented for tests of the aluminum plate with the repair patch under monotonic quasi-static and dynamic loading vibratory conditions. In summary, the

  19. Electrostatic patch potentials in Casimir force measurements

    NASA Astrophysics Data System (ADS)

    Garrett, Joseph; Somers, David; Munday, Jeremy

    2015-03-01

    Measurements of the Casimir force require the elimination of the electrostatic force between interacting surfaces. The force can be minimized by applying a potential to one of the two surfaces. However, electrostatic patch potentials remain and contribute an additional force which can obscure the Casimir force signal. We will discuss recent measurements of patch potentials made with Heterodyne Amplitude-Modulated Kelvin Probe Force Microscopy that suggest patches could be responsible for >1% of the signal in some Casimir force measurements, and thus make the distinction between different theoretical models of the Casimir force (e.g. a Drude-model or a plasma-model for the dielectric response) difficult to discern.

  20. Koch fractal boundary patch over reactive impedance

    NASA Astrophysics Data System (ADS)

    Reddy V, Venkateshwar; Sarma, N. V. S. N.

    2013-04-01

    This paper describes the enhancement of bandwidth and miniaturization for patch antennas. Introduction of fractal structure (Square Koch) over reactive impedance surface (RIS) is used to enhance impedance bandwidth while minimizing the patch size. Comparison has been made with those of a single-layer (sub1) antenna and the corresponding dual-layer (RIS) antenna. Approximately double the impedance bandwidth is achieved with the proposed RIS Square Koch antenna 1 when compared with Square Koch antenna 1without RIS. There is a 55 % reduction in the patch size. The simulated results indicate that the presented antennas provide gain of about 2.5dBi over the entire band of frequencies.

  1. Highly corrosion resistant weld overlay for oil patch applications

    SciTech Connect

    Hibner, E.L.; Maligas, M.N.; Vicic, J.C.

    1994-12-31

    Petroleum equipment companies currently sell 4130 and 4140 steel pipe with alloy 625 (UNS N06625) weld overlay for Oil Patch applications. Alloy 686 (UNS N06686), because of it`s superior corrosion resistance, is currently being evaluated as a replacement material for alloy 625. Mechanical properties and Slow Strain Rate test results for the alloy 686 weld overlay are discussed relative to the alloy 625 weld overlay.

  2. Investigations of 3C-SiC inclusions in 4H-SiC epilayers on 4H-SiC single crystal substrates

    SciTech Connect

    Si, W.; Dudley, M.; Kong, H.S.; Sumakeris, J.; Carter, C. Jr.

    1997-03-01

    Synchrotron white beam x-ray topography (SWBXT) and Nomarski optical microscopy (NOM) have been used to characterize 4H-SiC epilayers and to study the character of triangular inclusions therein. 4H-SiC substrates misoriented by a range of angles from (0001), as well as (1 1{bar 0}0) and (11 2{bar 0}) oriented substrates were used. No evidence was found for the nucleation of 3C-SiC inclusions at superscrew dislocations (along the [0001] axis) in the 4H-SiC substrates. Increasing the off-axis angle of the substrates from 3.5 to 6.5{degree} was found to greatly suppress the formation of the triangular inclusions. In the case of substrates misoriented by 8.0{degree} from (0001) toward [112{bar 0}], the triangular inclusions were virtually eliminated. The crystalline quality of 4H-SiC epilayers grown on the substrates misoriented by 8.0{degree} from (0001) was very good. For the (11{bar 0}0) and (112{bar 0}) samples, there is no indication of 3C-SiC inclusions in the epilayers. Possible formation mechanisms and the morphology of 3C-SiC inclusions are discussed. 17 refs., 13 figs.

  3. Wiggles and Wags: Dog 1--Fun Activities for You and Your Dog. 4-H Skills for Life Animal Series. National 4-H Curriculum. BU-08166

    ERIC Educational Resources Information Center

    National 4-H Council, 2005

    2005-01-01

    These guides are activity guides. Several fact-filled books about dogs are listed as resources on this guide. The activities are active, hands-on, and engaging and are guided by the 4-H motto: Learning by Doing. As youth explore a dog project topic of interest to them, they also practice essential life skills. Although a few dog project youth will…

  4. Electrical Characterization of 4H-SiC JFET Wafer: DC Parameter Variations for Extreme Temperature IC Design

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Chen, Liangyu; Spry, David J.; Beheim, Glenn M.; Chang, Carl W.

    2014-01-01

    This work reports DC electrical characterization of a 76 mm diameter 4H-SiC JFET test wafer fabricated as part of NASA's on-going efforts to realize medium-scale ICs with prolonged and stable circuit operation at temperatures as high as 500 degC. In particular, these measurements provide quantitative parameter ranges for use in JFET IC design and simulation. Larger than expected parameter variations were observed both as a function of position across the wafer as well as a function of ambient testing temperature from 23 degC to 500 degC.

  5. Impact of host plant connectivity, crop border and patch size on adult Colorado potato beetle retention.

    PubMed

    Boiteau, Gilles; Vincent, Charles; Leskey, Tracy C; Colpitts, Bruce G; MacKinley, Pamela; Lee, Doo-Hyung

    2014-01-01

    Tagged Colorado potato beetles (CPB), Leptinotarsa decemlineata (Say), were released on potato plants, Solanum tuberosum L., and tracked using a portable harmonic radar system to determine the impact of host plant spatial distribution on the tendency of the pest to remain on the colonized host plant or patch. Results confirmed the long residency time on the host plant and showed that close connection of the plant to neighboring plants hastened dispersal between plants. Tracking walking CPB for over 6 h in small potato plots revealed that all types of mixed borders tested (potato/bare ground, potato/timothy and potato/woodland) acted as a strong barrier and retained beetles within the patch. In another experiment in potato patches surrounded by bare ground borders, tracked walking CPB displayed similar behaviour for up to four days. The distribution of turning angles in the CPB walking paths was not uniform and corresponded to beetles following the edge rows of potato patches in response to the crop border barrier or reversing their direction as they reached the end of a row and therefore a border. Patch size had no or little effect on beetle retention in the patch. The relative distribution of counts of tagged beetles detected among small (16 m2), medium (64 m2) and large size (256 m2) patches of potato four days after initial release remained similar to that of numbers released. Even though mixed crop borders were a strong barrier to walking CPB emigrating from potato patches, the departure rate of beetles over time was high. Results suggest that the effect of mixed borders is largely limited to dispersal by walking and does not apply to beetles leaving host patches by flight. The manipulation of crop borders and patch size seem to have limited potential for the management of CPB emigrating from potato fields. PMID:24816717

  6. Using Multiple Youth Programming Delivery Modes to Drive the Development of Social Capital in 4-H Participants

    ERIC Educational Resources Information Center

    Kinsey, Sharon

    2013-01-01

    This article focuses on how 4-H youth participants are building social capital, or connections among individuals and community members, through their 4-H experiences. These experiences can be seen through the lens of such 4-H delivery modes as the traditional 4-H club, after-school programs, and school enrichment programs. In addition, other…

  7. Contaminant exposures at the 4H shell mounds in the Santa Barbara Channel.

    PubMed

    Phillips, Charles R; Salazar, Michael H; Salazar, Sandra M; Snyder, Barry J

    2006-12-01

    Remobilization, bioavailability, and potential toxicity of chemical contaminants were evaluated at the 4H shell mounds - the site of abandoned offshore oil and gas production platforms in the Santa Barbara Channel region of the Southern California Bight. Evaluations used a weight-of-evidence approach based on results from bulk phase chemical analyses and laboratory toxicity testing of shell mound cores, in situ field bioassays using caged mussels, and surficial sediment chemistry. Shell mound cores contained elevated concentrations of metals associated with drilling wastes (e.g., Ba, Cr, Pb, and Zn), as well as monocyclic and polycyclic aromatic hydrocarbons (PAHs). The highest concentrations along with pockets of free oil were associated with the middle "cuttings" stratum. Sediments composited from all core strata caused significant acute toxicity and bioaccumulation of Ba and PAHs in test organisms during laboratory exposures. In contrast, caged mussels placed at each of the shell mounds for a period of 57-58 days had greater than 90% survival, and there were no significant differences in survival of mussels placed at the shell mounds and corresponding reference sites. While all mussel samples exhibited increases in shell length, whole animal weight, and tissue lipid content, in some cases growth metrics for the shell mound mussels were significantly higher than those for the reference sites. Concentrations of metals, PAHs, and polychlorinated biphenyls (PCBs) in tissues of the shell mound mussels were not significantly different from those at reference sites. The presence of labile aromatic hydrocarbons in shell mound cores and absence of significant contaminant accumulation of tissues of caged mussels indicated that chemical contaminants are not being remobilized from the 4H shell mounds. Surficial bottom sediments near the shell mounds contained elevated Ba concentrations that probably were associated with drilling wastes. However, concentrations did not

  8. Synthesis and characterization of 4-aryl-4H-chromenes from H-cardanol.

    PubMed

    Rao, Hulluru Surya Prakash; Kamalraj, Mani

    2014-09-01

    We have synthesized and characterized a variety of fat-soluble, low-melting and medicinally useful 4-aryl-4H-chromenes from H-cardanol (side-chain perhydrogenated cardanol, 3-pentadecylphenol), a renewable and low-cost product from locally grown cashew nut trees (Anacardium occidentale L.). We incorporated H-cardanol into the aromatic rings of either 4H-chromene or phenol, or both. Substitution of C4SMe in N-methyl-4-(methylthio)-3-nitro-4H-chromene-2-amines with H-cardanol was regio-specific at the C6 position. PMID:25918806

  9. Ethinyl Estradiol and Norelgestromin Transdermal Patch

    MedlinePlus

    ... contraceptive patch is a very effective method of birth control, but it does not prevent the spread of ... period, you must use a backup method of birth control (such as a condom and/or a spermicide) ...

  10. Scattering from arbitrarily shaped microstrip patch antennas

    NASA Technical Reports Server (NTRS)

    Shively, David G.; Deshpande, Manohar D.; Cockrell, Capers R.

    1992-01-01

    The scattering properties of arbitrarily shaped microstrip patch antennas are examined. The electric field integral equation for a current element on a grounded dielectric slab is developed for a rectangular geometry based on Galerkin's technique with subdomain rooftop basis functions. A shape function is introduced that allows a rectangular grid approximation to the arbitrarily shaped patch. The incident field on the patch is expressed as a function of incidence angle theta(i), phi(i). The resulting system of equations is then solved for the unknown current modes on the patch, and the electromagnetic scattering is calculated for a given angle. Comparisons are made with other calculated results as well as with measurements.

  11. An evaluation of patch connectivity measures.

    PubMed

    Prugh, Laura R

    2009-07-01

    Measuring connectivity is critical to the study of fragmented populations. The three most commonly used types of patch connectivity measures differ substantially in how they are calculated, but the performance of these measures has not been broadly assessed. Here I compare the ability of nearest neighbor (NN), buffer, and incidence function model (IFM) measures to predict the patch occupancy and colonization patterns of 24 invertebrate, reptile, and amphibian metapopulations. I predicted that NN measures, which have been criticized as being overly simplistic, would be the worst predictors of species occupancy and colonization. I also predicted that buffer measures, which sum the amount of habitat in a radius surrounding the focal patch, would have intermediate performance, and IFM measures, which take into account the areas and distances to all potential source patches, would perform best. As expected, the simplest NN measure (distance to the nearest habitat patch, NHi) was the poorest predictor of patch occupancy and colonization. Contrary to expectations, however, the next-simplest NN measure (distance to the nearest occupied [source] patch, NSi) was as good a predictor of occupancy and colonization as the best-performing buffer measure and the general IFM measure Si. In contrast to previous studies suggesting that area-based connectivity measures perform better than distance-based ones, my results indicate that the exclusion of vacant habitat patches from calculations is the key to improved measure performance. I highlight several problems with the parameterization and use of IFM measures and suggest that models based on NSi are equally powerful and more practical for many conservation applications. PMID:19688936

  12. Aspects and applications of patched grid calculations

    NASA Technical Reports Server (NTRS)

    Walters, Robert W.; Switzer, George F.; Thomas, James L.

    1991-01-01

    Patched grid calculations within the framework of an implicit, flux vector split upwind/relaxation algorithm for the Euler equations are presented. Aspects of computing on patched grids are discussed including the effect of a metric-discontinuous interface on the convergence rate of the algorithm, and the effect of curvature along an interface. Applications to a converging-diverging nozzle including effects of choking and bypass slots in two dimensions are presented.

  13. Characterization of tungsten-nickel simultaneous Ohmic contacts to p- and n-type 4H-SiC

    NASA Astrophysics Data System (ADS)

    Kragh-Buetow, K. C.; Okojie, R. S.; Lukco, D.; Mohney, S. E.

    2015-10-01

    Ohmic contacts to p- and n-type 4H-SiC using refractory alloyed W:Ni thin films were investigated. Transfer length measurement test structures to p-type 4H-SiC (NA = 3 × 1020 cm-3) revealed Ohmic contacts with specific contact resistances, ρc, of ˜10-5 Ω cm2 after 0.5 h annealing in argon at temperatures of 1000 °C, 1100 °C, 1150 °C, and 1200 °C. Contacts fabricated on n-type 4H-SiC (ND = 2 × 1019 cm-3) by similar methods were shown to have similar specific contact resistance values after annealing, demonstrating simultaneous Ohmic contact formation for W:Ni alloys on 4H-SiC. The lowest ρc values were (7.3 ± 0.9) × 10-6 Ω cm2 for p-SiC and (6.8 ± 3.1) × 10-6 Ω cm2 for n-SiC after annealing at 1150 °C. X-ray diffraction shows a cubic tungsten-nickel-carbide phase in the Ohmic contacts after annealing as well as WC after higher temperatures. Auger electron spectroscopy depth profiles support the presence of metal carbide regions above a nickel and silicon-rich region near the interface. X-ray energy dispersive spectroscopy mapping showed tungsten-rich and nickel-rich regions after annealing at 1100 °C and above. W:Ni alloys show promise as simultaneous Ohmic contacts to p- and n-SiC, offering low and comparable ρc values along with the formation of WxNiyC.

  14. Preparation of Mucoadhesive Oral Patches Containing Tetracycline Hydrochloride and Carvacrol for Treatment of Local Mouth Bacterial Infections and Candidiasis

    PubMed Central

    Obaidat, Rana M.; Bader, Ammar; Al-Rajab, Wafa; Abu Sheikha, Ghassan; Obaidat, Aiman A.

    2011-01-01

    The specific aim of this work was to prepare mucoadhesive patches containing tetracycline hydrochloride and carvacrol in an attempt to develop a novel oral drug delivery system for the treatment of mouth infections. The bilayered patches were prepared using ethyl cellulose as a backing layer and carbopol 934 as a matrix mucoadhesive layer. Patches were prepared with different loading amounts of tetracycline hydrochloride and carvacrol. The antimicrobial activity was assessed for the prepared patches using the disc-diffusion method against the yeast Candida albicans and five bacterial strains, including Pseudomonas aeruginosa, Escherichia coli, Bacillus cereus, Staphylococcus aureus, and Bacillus bronchispti. In this work, we highlighted the possibility of occurrence of a synergistic action between carvacrol and tetracycline. The best formulation was selected based on microbiological tests, drug release, ex-vivo mucoadhesive performance, and swelling index. Physical characteristics of the selected formulations were determined. These included pH, patch thickness, weight uniformity, content uniformity, folding endurance, and patch stability. PMID:21617783

  15. Pericardial patch venoplasty heals via attraction of venous progenitor cells.

    PubMed

    Bai, Hualong; Wang, Mo; Foster, Trenton R; Hu, Haidi; He, Hao; Hashimoto, Takuya; Hanisch, Jesse J; Santana, Jeans M; Xing, Ying; Dardik, Alan

    2016-06-01

    Pericardial patches are commonly used during cardiovascular surgery to close blood vessels. In arteries, patches accumulate arterial progenitor cells; we hypothesized that venous patches would accumulate venous progenitor cells, in the absence of arterial pressure. We developed a novel rat inferior vena cava (IVC) venotomy model and repaired it with a pericardial patch. Cells infiltrated the patch to form a thick neointima by day 7; some cells were CD34(+)/VEGFR2(+) and CD31(+)/Eph-B4(+) consistent with development of venous identity in the healing patch. Compared to arterial patches, the venous patches had increased neointimal thickness at day 7 without any pseudoaneurysms. Addition of an arteriovenous fistula (AVF) to increase blood flow on the patch resulted in reduced patch neointimal thickness and proliferation, but neointimal thickness was not reversible with AVF ligation. These results show that rat patch venoplasty is a novel model of aggressive venous neointimal hyperplasia. PMID:27354544

  16. Pulse Dynamics in Endocytic Protein Patches

    NASA Astrophysics Data System (ADS)

    Carlsson, Anders; Wang, Xinxin

    2015-03-01

    During the process of endocytosis in yeast, submicron-sized protein patches assemble, exert forces on the membrane to bend it, and finally disassemble. The patches contain an initial coat that establishes the endocytic site and binds cargo, polymers of the protein actin, ``nucleation-promoting factors'' (NPFs) that catalyze actin polymerization, and curvature-generating proteins. We model the dynamics of protein patches in yeast using a variant of the activator-inhibitor ``Fitzhugh-Nagumo'' model. We treat NPFs as the activator, and polymerized actin as the inhibitor, on the basis of findings that the lifetime of NPF patches is extended when actin polymerization is inhibited. Using this model, we find that as the polymerization rate is reduced, there is a discontinuous transition from protein pulses to persistent patches. We also find, surprisingly, that in some parameter regimes reducing the polymerization rate can increase the polymerized-actin content of the patch. We present data for NPF dynamics budding yeast, which confirm some of the predictions of the model. Supported by NIH under Grant R01-GM107667.

  17. The effects of patch shape and connectivity on nest site selection and reproductive success of the Indigo Bunting.

    SciTech Connect

    Weldon, Aimee Jean

    2004-07-01

    Description – Ph.D Dissertation. North Carolina State University. Raleigh, North Carolina. 135 pp. Abatract - Habitat fragmentation and its associated effects have been blamed for the recent population declines of many Neotropical migratory bird species. Increased predation and parasitism resulting from edge-related effects have been implicated for poor nesting success in many studies, mostly of forest interior species. However, little attention has been devoted to disturbance-dependent birds. In this study, I examine how patch shape and connectivity in fragmented landscapes affects the reproductive success of disturbance-dependent bird species, specifically the Indigo Bunting (Passerina cyanea). I conducted my study in a landscape-scale experimental system of similar-area habitat patches that differed in connectivity and in shape. Shapes differed between edgy and rectangular forms, where edgy patches contained 50% more edge than rectangular patches. I tested whether edgy patches function as ecological traps for species with strong edge preferences, by leading them to select dangerous habitats. Indigo Buntings preferentially selected edgy patches over rectangular patches, but experienced significantly lower reproductive success in edgy patches early in the season. Although predation pressure intensified in rectangular patches late in the season, seasonal fecundity was still significantly lower in edgy patches, providing the first empirical evidence that edges can function as ecological traps for Indigo Buntings. A second objective of my study was to evaluate the efficacy of conservation corridors for disturbance-dependent bird species. Conservation corridors have become a popular strategy to preserve biodiversity and promote gene flow in fragmented landscapes, but corridors may also have negative consequences. I tested the hypothesis that corridors can increase nest predation risk in connected patches relative to unconnected patches. Nest predation rates

  18. Al4H7− is a resilient building block for aluminum hydrogen cluster materials

    PubMed Central

    Roach, P. J.; Reber, A. C.; Woodward, W. H.; Khanna, S. N.; Castleman, A. W.

    2007-01-01

    The formation and oxygen etching of AlnHm− clusters are characterized in a flow reactor experiment with first-principles theoretical investigations to demonstrate the exceptional stability of Al4H7−. The origin of the preponderance of Al4H7− in the mass spectra of hydrogenated aluminum anions and its resistance to O2 etching are discussed. Al4H7− is shown to have the ability to bond with ionic partners to form stable hydrides through addition of an alkali atom [XAl4H7 (X = Li-Cs)]. An intuitive model that can predict the existence of stable hydrogenated cluster species is proposed. The potential synthetic utility of the superatom assemblies built on these units is addressed. PMID:17823245

  19. Ohio 4-H Agents' and Volunteer Leaders' Perceptions of the Volunteer Leadership Development Program.

    ERIC Educational Resources Information Center

    Kwarteng, Joseph A.; And Others

    1988-01-01

    This study found that six areas of volunteer leadership development are important to volunteers and 4-H agents. The areas are (1) recruiting, (2) training, (3) motivation, (4) recognition, (5) retention, and (6) supervision. (JOW)

  20. Characterization of deep electron traps in 4H-SiC Junction Barrier Schottky rectifiers

    NASA Astrophysics Data System (ADS)

    Gelczuk, Ł.; Dąbrowska-Szata, M.; Sochacki, M.; Szmidt, J.

    2014-04-01

    Conventional deep level transient spectroscopy (DLTS) technique was used to study deep electron traps in 4H-SiC Junction Barrier Schottky (JBS) rectifiers. 4H-SiC epitaxial layers, doped with nitrogen and grown on standard n+-4H-SiC substrates were exposed to low-dose aluminum ion implantation process under the Schottky contact in order to form both JBS grid and junction termination extension (JTE), and assure good rectifying properties of the diodes. Several deep electron traps were revealed and attributed to impurities or intrinsic defects in 4H-SiC epitaxial layers, on the basis of comparison of their electrical parameters (i.e. activation energies, apparent capture cross sections and concentrations) with previously published results.

  1. Transdermal nicotine patches do not cause clinically significant gastroesophageal reflux or esophageal motor disorders.

    PubMed

    Wright, R A; Goldsmith, L J; Ameen, V; D'Angelo, A; Kirby, S L; Prakash, S

    1999-12-01

    Transdermal nicotine delivery systems are widely used in smoking cessation. The purpose of this study was to determine whether common symptoms of pyrosis and dyspepsia associated with these patches are related to gastroesophageal reflux or esophageal dysmotility. Twenty-seven paid volunteer cigarette smokers (> 15 cigarettes/day) without symptomatic gastroesophageal reflux disease participated in this single-blinded, placebo-controlled study. Twenty subjects completed the study. Subjects underwent three sequential 24-h intraesophageal pH/motor studies (Synectics model T32342084, Shore View, MN). The pH/motility probe was positioned 5 cm above the manometrically determined LES. A placebo patch was applied for the first 24-h study and a 15-mg nicotine patch (Nicotrol) was applied for the initial 16 h (removed for remaining 8 h) of the second 24-h period. A 21-mg nicotine patch (Nicoderm) was applied for another 24-h study period. All subjects consumed an identical, defined diet documented by meal receipts, and refrained from smoking and tobacco use throughout the study periods (CO breath test confirmation). The Wilcoxon, paired t-test, exact McNemar statistical methods were used. The results showed that there were no significant differences in reflux symptoms (pyrosis, chest pain, nausea, dysphagia), supine gastroesophageal reflux (number of episodes, duration, or cumulative acid exposure), or the total number of reflux episodes between placebo and nicotine patch treatment periods. The number of post-prandial upright acid reflux episodes (p = 004) and number of upright acid reflux episodes lasting more than 5 min (p = 0.007) were statistically higher with the placebo patch compared to the active nicotine patches. No differences in intraesophageal pH or motility indices were noted between the two transdermal nicotine patches (Nicotrol, Nicoderm). It was concluded that dyspeptic symptoms in subjects utilizing transdermal nicotine patches are not related to

  2. Short-term monocular patching boosts the patched eye’s response in visual cortex

    PubMed Central

    Zhou, Jiawei; Baker, Daniel H.; Simard, Mathieu; Saint-Amour, Dave; Hess, Robert F.

    2015-01-01

    Abstract Purpose: Several recent studies have demonstrated that following short-term monocular deprivation in normal adults, the patched eye, rather than the unpatched eye, becomes stronger in subsequent binocular viewing. However, little is known about the site and nature of the underlying processes. In this study, we examine the underlying mechanisms by measuring steady-state visual evoked potentials (SSVEPs) as an index of the neural contrast response in early visual areas. Methods: The experiment consisted of three consecutive stages: a pre-patching EEG recording (14 minutes), a monocular patching stage (2.5 hours) and a post-patching EEG recording (14 minutes; started immediately after the removal of the patch). During the patching stage, a diffuser (transmits light but not pattern) was placed in front of one randomly selected eye. During the EEG recording stage, contrast response functions for each eye were measured. Results: The neural responses from the patched eye increased after the removal of the patch, whilst the responses from the unpatched eye remained the same. Such phenomena occurred under both monocular and dichoptic viewing conditions. Conclusions: We interpret this eye dominance plasticity in adult human visual cortex as homeostatic intrinsic plasticity regulated by an increase of contrast-gain in the patched eye. PMID:26410580

  3. Edge termination study and fabrication of a 4H-SiC junction barrier Schottky diode

    NASA Astrophysics Data System (ADS)

    Chen, Feng-Ping; Zhang, Yu-Ming; Zhang, Yi-Men; Tang, Xiao-Yan; Wang, Yue-Hu; Chen, Wen-Hao

    2011-11-01

    The 4H-SiC junction barrier Schottky (JBS) diodes terminated by field guard rings and offset field plate are designed, fabricated and characterized. It is shown experimentally that a 3-μ P-type implantation window spacing gives an optimum trade-off between forward drop voltage and leakage current density for these diodes, yielding a specific on-resistance of 8.3 mΩ·cm2. A JBS diode with a turn-on voltage of 0.65 V and a reverse current density less than 1 A/cm2 under 500 V is fabricated, and the reverse recovery time is tested to be 80 ns, and the peak reverse current is 28.1 mA. Temperature-dependent characteristics are also studied in a temperature range of 75 °C-200 °C. The diode shows a stable Schottky barrier height of up to 200 °C and a stable operation under a continuous forward current of 100 A/cm2.

  4. Phosphorus doping of 4H SiC by liquid immersion excimer laser irradiation

    SciTech Connect

    Ikeda, Akihiro; Nishi, Koji; Ikenoue, Hiroshi; Asano, Tanemasa

    2013-02-04

    Phosphorus doping of 4H SiC is performed by KrF excimer laser irradiation of 4H SiC immersed in phosphoric acid. Phosphorus is incorporated to a depth of a few tens of nanometers at a concentration of over 10{sup 20}/cm{sup 3} without generating significant crystal defects. Formation of a pn junction diode with an ideality factor of 1.06 is demonstrated.

  5. Ferromagnetism in proton irradiated 4H-SiC single crystal

    SciTech Connect

    Zhou, Ren-Wei; Wang, Hua-Jie; Chen, Wei-Bin; Li, Fei; Liu, Xue-Chao Zhuo, Shi-Yi; Shi, Er-Wei

    2015-04-15

    Room-temperature ferromagnetism is observed in proton irradiated 4H-SiC single crystal. An initial increase in proton dose leads to pronounced ferromagnetism, accompanying with obvious increase in vacancy concentration. Further increase in irradiation dose lowers the saturation magnetization with the decrease in total vacancy defects due to the defects recombination. It is found that divacancies are the mainly defects in proton irradiated 4H-SiC and responsible for the observed ferromagnetism.

  6. Medical Images Fusion with Patch Based Structure Tensor.

    PubMed

    Luo, Fen; Sun, Jiangfeng; Hou, Shouming

    2015-01-01

    Nowadays medical imaging has played an important role in clinical use, which provide important clues for medical diagnosis. In medical image fusion, the extraction of some fine details and description is critical. To solve this problem, a modified structure tensor by considering similarity between two patches is proposed. The patch based filter can suppress noise and add the robustness of the eigen-values of the structure tensor by allowing the use of more information of far away pixels. After defining the new structure tensor, we apply it into medical image fusion with a multi-resolution wavelet theory. The features are extracted and described by the eigen-values of two multi-modality source data. To test the performance of the proposed scheme, the CT and MR images are used as input source images for medical image fusion. The experimental results show that the proposed method can produce better results compared to some related approaches. PMID:26628927

  7. Fabrication of High-Q Nanobeam Photonic Crystals in Epitaxially Grown 4H-SiC.

    PubMed

    Bracher, David O; Hu, Evelyn L

    2015-09-01

    Silicon carbide (SiC) is an intriguing material due to the presence of spin-active point defects in several polytypes, including 4H-SiC. For many quantum information and sensing applications involving such point defects, it is important to couple their emission to high quality optical cavities. Here we present the fabrication of 1D nanobeam photonic crystal cavities (PCC) in 4H-SiC using a dopant-selective etch to undercut a homoepitaxially grown epilayer of p-type 4H-SiC. These are the first PCCs demonstrated in 4H-SiC and show high quality factors (Q) of up to ∼7000 as well as low modal volumes of <0.5 (λ/n)(3). We take advantage of the high device yield of this fabrication method to characterize hundreds of devices and determine which PCC geometries are optimal. Additionally, we demonstrate two methods to tune the resonant wavelengths of the PCCs over 5 nm without significant degradation of the Q. Lastly, we characterize nanobeam PCCs coupled to luminescence from silicon vacancy point defects (V1, V2) in 4H-SiC. The fundamental modes of two such PCCs are tuned into spectral overlap with the zero phonon line (ZPL) of the V2 center, resulting in an intensity increase of up to 3-fold. These results are important steps on the path to developing 4H-SiC as a platform for quantum information and sensing. PMID:26305122

  8. Key contribution of eIF4H-mediated translational control in tumor promotion

    PubMed Central

    Vaysse, Charlotte; Philippe, Céline; Martineau, Yvan; Quelen, Cathy; Hieblot, Corinne; Renaud, Claire; Nicaise, Yvan; Desquesnes, Aurore; Pannese, Maria; Filleron, Thomas; Escourrou, Ghislaine; Lawson, Malcolm; Rintoul, Robert C.; Delisle, Marie Bernadette; Pyronnet, Stéphane; Brousset, Pierre; Prats, Hervé; Touriol, Christian

    2015-01-01

    Dysregulated expression of translation initiation factors has been associated with carcinogenesis, but underlying mechanisms remains to be fully understood. Here we show that eIF4H (eukaryotic translation initiation factor 4H), an activator of the RNA helicase eIF4A, is overexpressed in lung carcinomas and predictive of response to chemotherapy. In lung cancer cells, depletion of eIF4H enhances sensitization to chemotherapy, decreases cell migration and inhibits tumor growth in vivo, in association with reduced translation of mRNA encoding cell-proliferation (c-Myc, cyclin D1) angiogenic (FGF-2) and anti-apoptotic factors (CIAP-1, BCL-xL). Conversely, each isoform of eIF4H acts as an oncogene in NIH3T3 cells by stimulating transformation, invasion, tumor growth and resistance to drug-induced apoptosis together with increased translation of IRES-containing or structured 5′UTR mRNAs. These results demonstrate that eIF4H plays a crucial role in translational control and can promote cellular transformation by preferentially regulating the translation of potent growth and survival factor mRNAs, indicating that eIF4H is a promising new molecular target for cancer therapy. PMID:26498689

  9. Association analysis of the LTA4H gene polymorphisms and pulmonary tuberculosis in 9115 subjects

    PubMed Central

    Curtis, James; Kopanitsa, Liliya; Stebbings, Emma; Speirs, Arran; Ignatyeva, Olga; Balabanova, Yanina; Nikolayevskyy, Vladyslav; Hoffner, Sven; Horstmann, Rolf; Drobniewski, Francis; Nejentsev, Sergey

    2011-01-01

    Summary Immunoregulatory eicosanoids have been implicated in protection from mycobacterial infection in cell and animal models. Recently, a study of the zebrafish embryo demonstrated that mutants of the lta4h gene, which encodes the leukotriene A4 hydrolase (LTA4H) enzyme of the eicosanoid pathway, have hypersusceptibility to Mycobacterium marinum infection. It also reported that heterozygosity at the two single nucleotide polymorphisms rs1978331 and rs2660898 located in introns of the LTA4H gene, a human homologue of lta4h, is associated with protection from pulmonary tuberculosis. To replicate this association we genotyped six LTA4H gene polymorphisms in samples from 3703 pulmonary tuberculosis patients and 5412 healthy controls collected in Russia. We found no evidence of the protective effect of heterozygosity at the polymorphisms rs1978331 and rs2660898 (P = 0.29 and 0.49) and no association of the alleles of any of the six polymorphisms (P = 0.13–0.81). These results suggest that common polymorphisms in the LTA4H gene do not play any major role in susceptibility to clinical pulmonary tuberculosis. PMID:21112816

  10. Complex interaction of dendritic connectivity and hierarchical patch size on biodiversity in river-like landscapes.

    PubMed

    Carrara, Francesco; Rinaldo, Andrea; Giometto, Andrea; Altermatt, Florian

    2014-01-01

    Habitat fragmentation and land use changes are causing major biodiversity losses. Connectivity of the landscape or environmental conditions alone can shape biodiversity patterns. In nature, however, local habitat characteristics are often intrinsically linked to a specific connectivity. Such a link is evident in riverine ecosystems, where hierarchical dendritic structures command related scaling on habitat capacity. We experimentally disentangled the effect of local habitat capacity (i.e., the patch size) and dendritic connectivity on biodiversity in aquatic microcosm metacommunities by suitably arranging patch sizes within river-like networks. Overall, more connected communities that occupy a central position in the network exhibited higher species richness, irrespective of patch size arrangement. High regional evenness in community composition was found only in landscapes preserving geomorphological scaling properties of patch sizes. In these landscapes, some of the rarer species sustained regionally more abundant populations better tracking their own niche requirements compared to landscapes with homogeneous patch size or landscapes with spatially uncorrelated patch size. Our analysis suggests that altering the natural link between dendritic connectivity and patch size strongly affects community composition and population persistence at multiple scales. The experimental results are demonstrating a principle that can be tested in theoretical metacommunity models and eventually be projected to real riverine ecosystems. PMID:24334732

  11. Patched-grid calculations with the Euler and Navier-Stokes equations: Theory and application

    NASA Technical Reports Server (NTRS)

    Rai, M. M.

    1986-01-01

    The Rai (1984,85) patch-boundary scheme for the Euler equations is described. The integration methods used to update the interior grid points are are discussed. Stability of patch-boundary schemes and the use of these schemes in Navier-Stokes calculations are mentioned. Results for inviscid, supersonic flow over a cylinder, blast wave diffraction by ramp, and the motion of a vortex in a freestream are presented. These test cases demonstrate the quality of solutions possible with the scheme.

  12. Measuring Radiation Patterns of Reconfigurable Patch Antennas on Wafers

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.

    2004-01-01

    An apparatus and technique have been devised for measuring the radiation pattern of a microwave patch antenna that is one of a number of identical units that have been fabricated in a planar array on a high-resistivity silicon wafer. The apparatus and technique are intended, more specifically, for application to such an antenna that includes a DC-controlled microelectromechanical system (MEMS) actuator for switching the antenna between two polarization states or between two resonance frequencies. Prior to the development of the present apparatus and technique, patch antennas on wafers were tested by techniques and equipment that are more suited to testing of conventional printed-circuit antennas. The techniques included sawing of the wafers to isolate individual antennas for testing. The equipment included custom-built test fixtures that included special signal launchers and transmission-line transitions. The present apparatus and technique eliminate the need for sawing wafers and for custom-built test fixtures, thereby making it possible to test antennas in less time and at less cost. Moreover, in a production setting, elimination of the premature sawing of wafers for testing reduces loss from breakage, thereby enhancing yield.

  13. Methods of Making and Using Shape Memory Polymer Composite Patches

    NASA Technical Reports Server (NTRS)

    Hood, Patrick J.

    2011-01-01

    A method of repairing a composite component having a damaged area including: laying a composite patch over the damaged area: activating the shape memory polymer resin to easily and quickly mold said patch to said damaged area; deactivating said shape memory polymer so that said composite patch retains the molded shape; and bonding said composite patch to said damaged part.

  14. Allergy testing - skin

    MedlinePlus

    Patch tests - allergy; Scratch tests - allergy; Skin tests - allergy; RAST test ... There are three common methods of allergy skin testing. The skin prick test involves: Placing a small amount of substances that may be causing your symptoms on the skin, ...

  15. Directional magnetostrictive patch transducer based on Galfenol’s anisotropic magnetostriction feature

    NASA Astrophysics Data System (ADS)

    Yoo, Byungseok; Na, Suok-Min; Flatau, Alison B.; Pines, Darryll J.

    2014-09-01

    This paper presents the investigation of a directional magnetostrictive patch transducer (MPT) composed of a highly textured Galfenol (Fe-Ga alloy) patch in the use of ultrasonic guided Lamb wave (GLW) inspection techniques for isotropic planar structures. Recently, the actuation and sensing performance of an MPT using a disc patch made of polycrystalline nickel was reported, based on GLW testing in thin aluminum plates. The nickel-based MPT appeared to have omnidirectional GLW sensitivity in the metallic plate because of the isotropic magnetostrictive nature of polycrystalline nickel with random orientation. In this work, we investigated two viable methods to control and improve MPT’s directional sensitivity for detecting GLWs in metallic plate structures. First, we proposed a circular MPT (CMPT) using the highly textured Galfenol patch with a large magnetostriction of ˜270 ppm along a <100> preferred orientation parallel to the patch’s rolling direction. The CMPT exhibited outstanding sensitivity to incoming GLWs along the <100> direction of the patch in a thin aluminum plate. This was mainly due to the unique anisotropic magnetostriction effect of the textured Galfenol patch. In addition to the use of the Galfenol material, we developed a novel cruciform MPT (XMPT) containing four solenoid sensing coils that possessed individual directional sensing preferences, corresponding to the orientations of the sensing coils. The directional sensing performance of the XMPT was initially validated by using the polycrystalline nickel patch with the isotropic magnetostrictive characteristic, exhibiting the remarkable directionality attributes of the individual sensing elements. Of particular interest was that the XMPT combined with the highly textured Galfenol patch demonstrated excellent directional sensitivity corresponding to the Galfenol’s preferred orientation. And the directional sensing feature was noticeably enhanced by incorporating the textured Galfenol

  16. Plant community response to landscape connectivity and patch shape.

    SciTech Connect

    Damschen, Ellen I.

    2005-07-01

    Ph.D Dissertation. North Carolina State University. Raleigh, North Carolina. 135 pp. Abstract. Land transformation is the single most important factor promoting the global loss of terrestrial biological diversity. Remaining habitat fragments contain more edges, less interior habitat, and are more isolated from other habitat fragments, all of which decrease rates of colonization following local extinctions, reduce reproductive rates and gene flow between populations, and ultimately lead to species extinctions. The best approach to prevent species loss, therefore, is to preserve greater areas of habitat. In many cases, however, habitat has already been fragmented and strategies are needed to configure and manage the remaining land. Land managers often create reserve networks that incorporate the use of landscape corridors, linear strips of habitat connecting isolated patches, to reduce species loss by increasing colonizations and decreasing extinctions. Most empirical tests of corridors have been limited to individuals and populations, leaving corridor effects on diversity largely unknown, especially at large spatial scales. Additionally, only a handful of studies have examined corridor effects on plants, which may be especially sensitive to the abiotic changes resulting from alterations in patch shape due to dispersal limitation. Using one of the best-replicated, large-scale habitat fragmentation experiments, I tested explicitly for corridor effects on plant community diversity and composition by examining the established plant community and the soil seedbank. My experimental design distinguished among the three possible ways corridors can affect between-patch processes: by acting as a movement conduit between connected patches (“connectivity effects”), by increasing area alone (“area effects”), and by intercepting organisms moving across the landscape and filtering them into connected patches (“drift-fence effects”). Additionally, I tested for the

  17. PL-PatchSurfer: A Novel Molecular Local Surface-Based Method for Exploring Protein-Ligand Interactions

    PubMed Central

    Hu, Bingjie; Zhu, Xiaolei; Monroe, Lyman; Bures, Mark G.; Kihara, Daisuke

    2014-01-01

    Structure-based computational methods have been widely used in exploring protein-ligand interactions, including predicting the binding ligands of a given protein based on their structural complementarity. Compared to other protein and ligand representations, the advantages of a surface representation include reduced sensitivity to subtle changes in the pocket and ligand conformation and fast search speed. Here we developed a novel method named PL-PatchSurfer (Protein-Ligand PatchSurfer). PL-PatchSurfer represents the protein binding pocket and the ligand molecular surface as a combination of segmented surface patches. Each patch is characterized by its geometrical shape and the electrostatic potential, which are represented using the 3D Zernike descriptor (3DZD). We first tested PL-PatchSurfer on binding ligand prediction and found it outperformed the pocket-similarity based ligand prediction program. We then optimized the search algorithm of PL-PatchSurfer using the PDBbind dataset. Finally, we explored the utility of applying PL-PatchSurfer to a larger and more diverse dataset and showed that PL-PatchSurfer was able to provide a high early enrichment for most of the targets. To the best of our knowledge, PL-PatchSurfer is the first surface patch-based method that treats ligand complementarity at protein binding sites. We believe that using a surface patch approach to better understand protein-ligand interactions has the potential to significantly enhance the design of new ligands for a wide array of drug-targets. PMID:25167137

  18. A Novel Virus-Patch Dynamic Model.

    PubMed

    Yang, Lu-Xing; Yang, Xiaofan

    2015-01-01

    The distributed patch dissemination strategies are a promising alternative to the conventional centralized patch dissemination strategies. This paper aims to establish a theoretical framework for evaluating the effectiveness of distributed patch dissemination mechanism. Assuming that the Internet offers P2P service for every pair of nodes on the network, a dynamic model capturing both the virus propagation mechanism and the distributed patch dissemination mechanism is proposed. This model takes into account the infected removable storage media and hence captures the interaction of patches with viruses better than the original SIPS model. Surprisingly, the proposed model exhibits much simpler dynamic properties than the original SIPS model. Specifically, our model admits only two potential (viral) equilibria and undergoes a fold bifurcation. The global stabilities of the two equilibria are determined. Consequently, the dynamical properties of the proposed model are fully understood. Furthermore, it is found that reducing the probability per unit time of disconnecting a node from the Internet benefits the containment of electronic viruses. PMID:26368556

  19. A Novel Virus-Patch Dynamic Model

    PubMed Central

    Yang, Lu-Xing; Yang, Xiaofan

    2015-01-01

    The distributed patch dissemination strategies are a promising alternative to the conventional centralized patch dissemination strategies. This paper aims to establish a theoretical framework for evaluating the effectiveness of distributed patch dissemination mechanism. Assuming that the Internet offers P2P service for every pair of nodes on the network, a dynamic model capturing both the virus propagation mechanism and the distributed patch dissemination mechanism is proposed. This model takes into account the infected removable storage media and hence captures the interaction of patches with viruses better than the original SIPS model. Surprisingly, the proposed model exhibits much simpler dynamic properties than the original SIPS model. Specifically, our model admits only two potential (viral) equilibria and undergoes a fold bifurcation. The global stabilities of the two equilibria are determined. Consequently, the dynamical properties of the proposed model are fully understood. Furthermore, it is found that reducing the probability per unit time of disconnecting a node from the Internet benefits the containment of electronic viruses. PMID:26368556

  20. Patch-primitive driven compressive ghost imaging.

    PubMed

    Hu, Xuemei; Suo, Jinli; Yue, Tao; Bian, Liheng; Dai, Qionghai

    2015-05-01

    Ghost imaging has rapidly developed for about two decades and attracted wide attention from different research fields. However, the practical applications of ghost imaging are still largely limited, by its low reconstruction quality and large required measurements. Inspired by the fact that the natural image patches usually exhibit simple structures, and these structures share common primitives, we propose a patch-primitive driven reconstruction approach to raise the quality of ghost imaging. Specifically, we resort to a statistical learning strategy by representing each image patch with sparse coefficients upon an over-complete dictionary. The dictionary is composed of various primitives learned from a large number of image patches from a natural image database. By introducing a linear mapping between non-overlapping image patches and the whole image, we incorporate the above local prior into the convex optimization framework of compressive ghost imaging. Experiments demonstrate that our method could obtain better reconstruction from the same amount of measurements, and thus reduce the number of requisite measurements for achieving satisfying imaging quality. PMID:25969205

  1. Characterizing the morphology of protein binding patches.

    PubMed

    Malod-Dognin, Noël; Bansal, Achin; Cazals, Frédéric

    2012-12-01

    Let the patch of a partner in a protein complex be the collection of atoms accounting for the interaction. To improve our understanding of the structure-function relationship, we present a patch model decoupling the topological and geometric properties. While the geometry is classically encoded by the atomic positions, the topology is recorded in a graph encoding the relative position of concentric shells partitioning the interface atoms. The topological-geometric duality provides the basis of a generic dynamic programming-based algorithm comparing patches at the shell level, which may favor topological or geometric features. On the biological side, we address four questions, using 249 cocrystallized heterodimers organized in biological families. First, we dissect the morphology of binding patches and show that Nature enjoyed the topological and geometric degrees of freedom independently while retaining a finite set of qualitatively distinct topological signatures. Second, we argue that our shell-based comparison is effective to perform atomic-level comparisons and show that topological similarity is a less stringent than geometric similarity. We also use the topological versus geometric duality to exhibit topo-rigid patches, whose topology (but not geometry) remains stable upon docking. Third, we use our comparison algorithms to infer specificity-related information amidst a database of complexes. Finally, we exhibit a descriptor outperforming its contenders to predict the binding affinities of the affinity benchmark. The softwares developed with this article are availablefrom http://team.inria.fr/abs/vorpatch_compatch/. PMID:22806945

  2. Population densities and density-area relationships in a community with advective dispersal and variable mosaics of resource patches.

    PubMed

    Lancaster, Jill; Downes, Barbara J

    2014-12-01

    Many communities comprise species that select resources that are patchily distributed in an environment that is otherwise unsuitable or suboptimal. Effects of this patchiness can depend on the characteristics of patch arrays and animal movements, and produce non-intuitive outcomes in which population densities are unrelated to resource abundance. Resource mosaics are predicted to have only weak effects, however, where patches are ephemeral or organisms are transported advectively. The running waters of streams and benthic invertebrates epitomize such systems, but empirical tests of resource mosaics are scarce. We sampled 15 common macroinvertebrates inhabiting distinct detritus patches at four sites within a sand-bed stream, where detritus formed a major resource of food and living space. At each site, environmental variables were measured for 100 leaf packs; invertebrates were counted in 50 leaf packs. Sites differed in total abundance of detritus, leaf pack sizes and invertebrate densities. Multivariate analysis indicated that patch size was the dominant environmental variable, but invertebrate densities differed significantly between sites even after accounting for patch size. Leaf specialists showed positive and strong density-area relationships, except where the patch size range was small and patches were aggregated. In contrast, generalist species had weaker and variable responses to patch sizes. Population densities were not associated with total resource abundance, with the highest densities of leaf specialists in sites with the least detritus. Our results demonstrate that patchy resources can affect species even in communities where species are mobile, have advective dispersal, and patches are relatively ephemeral. PMID:25190216

  3. Adhesive RFID Sensor Patch for Monitoring of Sweat Electrolytes.

    PubMed

    Rose, Daniel P; Ratterman, Michael E; Griffin, Daniel K; Hou, Linlin; Kelley-Loughnane, Nancy; Naik, Rajesh R; Hagen, Joshua A; Papautsky, Ian; Heikenfeld, Jason C

    2015-06-01

    Wearable digital health devices are dominantly found in rigid form factors such as bracelets and pucks. An adhesive radio-frequency identification (RFID) sensor bandage (patch) is reported, which can be made completely intimate with human skin, a distinct advantage for chronological monitoring of biomarkers in sweat. In this demonstration, a commercial RFID chip is adapted with minimum components to allow potentiometric sensing of solutes in sweat, and surface temperature, as read by an Android smartphone app with 96% accuracy at 50 mM Na(+) (in vitro tests). All circuitry is solder-reflow integrated on a standard Cu/polyimide flexible-electronic layer including an antenna, but while also allowing electroplating for simple integration of exotic metals for sensing electrodes. Optional paper microfluidics wick sweat from a sweat porous adhesive allowing flow to the sensor, or the sensor can be directly contacted to the skin. The wearability of the patch has been demonstrated for up to seven days, and includes a protective textile which provides a feel and appearance similar to a standard Band-Aid. Applications include hydration monitoring, but the basic capability is extendable to other mM ionic solutes in sweat (Cl(-), K(+), Mg(2+), NH4(+), and Zn(2+)). The design and fabrication of the patch are provided in full detail, as the basic components could be useful in the design of other wearable sensors. PMID:25398174

  4. Can we go beyond burned area assessment with fire patch metrics from global remote rensing?

    NASA Astrophysics Data System (ADS)

    Nogueira Pereira Messias, Joana; Ruffault, Julien; Chuvieco, Emilio; Mouillot, Florent

    2016-04-01

    Fire is a major event influencing global biogeochemical cycles and contribute to the emissions of CO2 and other greenhouse gases to the atmosphere. Global burned area (BA) datasets from remote sensing have provided the fruitful information for quantifying carbon emissions in global biogeochemical models, and for DGVM's benchmarking. Patch level analysis from pixel level information recently emerged as an informative additional feature of the regime as fire size distribution. The aim of this study is to evaluate the ability of global BA products to accurately represent characteristics of fire patches (size, complexity shape and spatial orientation). We selected a site in the Brazilian savannas (Cerrado), one of the most fire prone biome and one of the validation test site for the ESA fire-Cci project. We used the pixel-level burned area detected by Landsat, MCD45A1 and the newly delivered MERIS ESA fire-Cci for the period 2002-2009. A flood-fill algorithm adapted from Archibald and Roy (2009) was used to identify the individual fire patches (patch ID) according to the burned date (BD). For each patch ID, we calculated a panel of patch metrics as area, perimeter and core area, shape complexity (shape index and fractal dimension) and the feature of the ellipse fitted over the spatial distribution of pixels composing the patch (eccentricity and direction of the main axis). Paired fire patches overlapping between each BA products were compared. The correlation between patch metrics were evaluated by linear regression models for each inter-product comparison according to fire size classes. Our results showed significant patch overlaps (>30%) between products for patches with areas larger than 270ha, with more than 90% of patches overlapping between MERIS and MCD45A1. Fire Patch metrics correlations showed R2>0.6 for all comparisons of patch Area and Core Area, with a slope of 0.99 between MERIS and MCD45A1 illustrating the agreement between the two global products. The

  5. Fault-patch stress-transfer efficiency in presence of sub-patch geometric complexity

    NASA Astrophysics Data System (ADS)

    Zielke, Olaf; Mai, Martin

    2015-04-01

    It is well known that faults are not planar surfaces. Instead they exhibit self-similar or self-affine properties that span a wide range of spatial (sub-micrometer to tens-of-kilometer). This geometric fault roughness has a distinct impact on amount and distribution of stresses/strains induced in the medium and on other portions of the fault. However, when numerically simulated (for example in multi-cycle EQ rupture simulations or Coulomb failure stress calculations) this roughness is largely ignored: individual fault patches --the incremental elements that build the fault surface in the respective computer models-- are planar and fault roughness at this and lower spatial scales is not considered. As a result, the fault-patch stress-transfer efficiency may be systematically too large in those numerical simulations with respect to the "actual" efficiency level. Here, we investigate the effect of sub-patch geometric complexity on fault-patch stress-transfer efficiency. For that, we sub-divide a fault patch (e.g., 1x1km) into a large number of sub-patches (e.g., 20x20m) and determine amount of induced stresses at selected positions around that patch for different levels and realizations of fault roughness. For each fault roughness level, we compute mean and standard deviation of the induced stresses, enabling us to compute the coefficient of variation. We normalize those values with stresses from the corresponding single (planar) fault patch, providing scaling factors and their variability for stress transfer efficiency. Given a certain fault roughness that is assumed for a fault, this work provides the means to implement the sub-patch fault roughness into investigations based on fault-patch interaction schemes.

  6. Comparative acceptance of three transdermal nitroglycerin placebo patches.

    PubMed

    Rayment, C M; Kaul, A F; Garfield, J M

    1985-06-01

    Factors that might affect patient acceptance of transdermal drug-delivery system patches were evaluated in healthy volunteers using placebo patches. Placebo transdermal nitroglycerin patches (Transderm-Nitro 5 placebo, Ciba Pharmaceutical Company; Nitro-Dur 10 cm2 placebo, Key Pharmaceuticals; and Nitrodisc 5 placebo, Searle Laboratories) were supplied by the manufacturers. Eighty-two healthy subjects were randomly assigned to begin using one of the three brands of patches. Using a Latin-square crossover design, subjects applied each brand of patch daily for five days and crossed over to the other brands on study days 6 and 11. At the end of each study phase, subjects completed a written questionnaire designed to evaluate their overall acceptance of each brand of patch. A total of 80 subjects completed all three phases of the study. According to forced rank preference, 84% of subjects preferred the Ciba patch to one of the other two brands. Subjects judged the Ciba patch to be the easiest of the three brands to use and reported significantly fewer side effects and skin irritation while using the Ciba patch; they also preferred the size of the Ciba patch and experienced significantly fewer problems with adherence of the Ciba patch. A significant percentage of subjects indicated that they would prefer a transdermal patch over tablets or ointment. Most subjects preferred the Ciba patch over the Key patch or Searle patch. PMID:3925770

  7. CVD Growth of 3C-SiC on 4H/6H Mesas

    SciTech Connect

    Neudeck,P.; Trunek, A.; Spry, D.; Powell, J.; Du, H.; Skowronski, M.; Huang, X.; Dudley, M.

    2006-01-01

    This article describes growth and characterization of the highest quality reproducible 3C-SiC heteroepitaxial films ever reported. By properly nucleating 3C-SiC growth on top of perfectly on-axis (0001) 4H-SiC mesa surfaces completely free of atomic scale steps and extended defects, growth of 3C-SiC mesa heterofilms completely free of extended crystal defects can be achieved. In contrast, nucleation and growth of 3C-SiC mesa heterofilms on top of 4H-SiC mesas with atomic-scale steps always results in numerous observable dislocations threading through the 3C-SiC epilayer. High-resolution X-ray diffraction (HRXRD) and high resolution cross-sectional transmission electron microscopy (HRXTEM) measurements indicate non-trivial, in-plane, lattice mismatch between the 3C and 4H layers. This mismatch is somewhat relieved in the step-free mesa case via misfit dislocations confined to the 3C/4H interfacial region without dislocations threading into the overlying 3C-SiC layer. These results indicate that the presence or absence of steps at the 3C/4H heteroepitaxial interface critically impacts the quality, defect structure, and relaxation mechanisms of single-crystal heteroepitaxial 3C-SiC films.

  8. Existence of {sub {lambda}}{sub {lambda}}{sup 4}H: A variational Monte Carlo search

    SciTech Connect

    Shoeb, Mohammad

    2005-02-01

    A variational Monte Carlo (VMC) calculation for the binding energy B{sub {lambda}}{sub {lambda}} of the lightest hypernucleus {sub {lambda}}{sub {lambda}}{sup 4}H has been performed in the four-body {lambda}{lambda}pn model. A range of input {lambda}{lambda} potentials of moderate strength produce a particle-stable {sub {lambda}}{sub {lambda}}{sup 4}H for the simulated NSC97e and f {lambda}N potentials, whereas the phenomenological Minnesota {lambda}N potential needs a much stronger {lambda}{lambda} potential to bind. The VMC results for B{sub {lambda}}{sub {lambda}} agree with the prediction of the stochastic variational model but contradict the recent Faddeev-Yakubovsky calculation. As reported earlier, B{sub {lambda}}{sub {lambda}} is sensitive to the triplet {lambda}N channel for a given {lambda}{lambda} potential. The B{sub {lambda}}{sub {lambda}} of {sub {lambda}}{sub {lambda}}{sup 4}H in the three-body {lambda}{lambda}d cluster model is consistent with but slightly lower than the Faddeev calculation. The VMC method predicts a stable {sub {lambda}}{sub {lambda}}{sup 4}H system in both models and thus offers the possibility of identifying {sub {lambda}}{sub {lambda}}{sup 4}H in a future extension of E906 or of a related experiment at KEK, provided the simulated potentials are true representations of realistic Nijmegen potentials.

  9. Self-assembly of C4H-type hydrogenated graphene.

    PubMed

    Liu, Zilong; Xue, Qingzhong; Xing, Wei; Du, Yonggang; Han, Zhide

    2013-11-21

    We demonstrate by molecular dynamic (MD) simulations that patterned partially hydrogenated graphene (C4H) can self-assemble at room temperature. The main driving force of the self-assembly of C4H is due to the one-sided distribution of hydrogen and the corresponding asymmetric orientation of sp(3) bonding, there exists strong electrostatic repulsion between the relatively close H atoms. The simulations show that C4H can self-assemble into various carbon nanoscroll (CNS) structures, this is mainly controlled by its geometry (size and aspect ratio). And the carbon nanotube (CNT) is a good candidate to activate and guide C4H to form CNS, whose core size can be controlled. Meanwhile, a novel CNT/C4H core/shell composite nanostructure is also formed. The theoretical results shed important light on a feasible approach to fabricate high-quality CNS and other novel nanostructures including core/shell structures, which hold great potential applications in optics, optoelectronic devices, hydrogen storage, sensors, and energy storage in supercapacitors or batteries. PMID:24064528

  10. CFD Growth of 3C-SiC on 4H/6H Mesas

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Trunek, Andrew J.; Spry, David J.; Powell, J. Anthony; Du, Hui; Skowronski, Marek; Huang, XianRong; Dudley, Michael

    2006-01-01

    This article describes growth and characterization of the highest quality reproducible 3C-SiC heteroepitaxial films ever reported. By properly nucleating 3C-SiC growth on top of perfectly on-axis (0001) 4H-SiC mesa surfaces completely free of atomic scale steps and extended defects, growth of 3C-SiC mesa heterofilms completely free of extended crystal defects can be achieved. In contrast, nucleation and growth of 3C-SiC mesa heterofilms on top of 4H-SiC mesas with atomic-scale steps always results in numerous observable dislocations threading through the 3C-SiC epilayer. High-resolution X-ray diffraction and transmission electron microscopy measurements indicate non-trivial in-plane lattice mismatch between the 3C and 4H layers. This mismatch is somewhat relieved in the step-free mesa case via misfit dislocations confined to the 3C/4H interfacial region without dislocations threading into the overlying 3C-SiC layer. These results indicate that the presence or absence of steps at the 3C/4H heteroepitaxial interface critically impacts the quality, defect structure, and relaxation mechanisms of single-crystal heteroepitaxial 3C-SiC films.

  11. Requirements for B7-CD28 costimulation in mucosal IgA responses: paradoxes observed in CTLA4-H gamma 1 transgenic mice.

    PubMed

    Gärdby, E; Lane, P; Lycke, N Y

    1998-07-01

    The block in the CD80/CD86-CD28/CTLA-4 pathway in CTLA4-H gamma 1 transgenic (Tg) mice results in strongly impaired systemic IgG immunity and failure to develop germinal center reactions. By contrast, here we report that mucosal immunity and IgA B cell differentiation are not affected by this block. We found abundant germinal centers and evidence of IgA switch differentiation in Peyer's patches, normal total IgA levels, and normal numbers of IgA-labeling cells in the gut mucosa. The distribution of B-1 and B-2 cells and the relative contribution of B-1 cells to the total IgA B cells were similar in Tg and wild-type mice. Despite this, oral immunizations with keyhole limpet hemocyanin plus cholera toxin adjuvant failed to stimulate Ag-specific mucosal IgA responses in CTLA4-H gamma 1 Tg mice. This was not due to a lack of adjuvant activity of cholera toxin in Tg mice, nor was this secondary to an inability to take up Ag from the gut lumen. Rather, CD4+ T cells stimulated by oral immunization in Tg mice appeared to be inappropriately primed, as evidenced by a significantly reduced level of CD40 ligand and CD44 expression and an increased expression of CD95 compared to those in wild-type mice. This study reveals a paradox in the regulation of mucosal IgA responses. PMID:9647206

  12. Dimensionality reduction via locally reconstructive patch alignment

    NASA Astrophysics Data System (ADS)

    Chen, Yi; Yin, Jun; Zhu, Jie; Jin, Zhong

    2012-07-01

    Based on the local patch concept, we proposed locally reconstructive patch alignment (LRPA) for dimensionality reduction. For each patch, LRPA aims to find the low-dimensional subspace in which the reconstruction error of the within-class nearest neighbors is minimized and the reconstruction error of the between-class nearest neighbors is maximized. LRPA preserves the local structure hidden in the high-dimensional space. More importantly, LRPA has natural connections with linear regression classification (LRC). While LRC uses reconstruction errors as the classification rule, a sample can be classified correctly when the within-class reconstruction error is minimal. The goal of LRPA makes it cooperate well with LRC. The experimental results on the extended Yale B (YALE-B), AR, PolyU finger knuckle print, and the palm print databases demonstrate LRPA plus LRC is an effective and robust pattern-recognition system.

  13. Patch-Clamp Fluorometry: Electrophysiology meets Fluorescence

    PubMed Central

    Kusch, Jana; Zifarelli, Giovanni

    2014-01-01

    Ion channels and transporters are membrane proteins whose functions are driven by conformational changes. Classical biophysical techniques provide insight into either the structure or the function of these proteins, but a full understanding of their behavior requires a correlation of both these aspects in time. Patch-clamp and voltage-clamp fluorometry combine spectroscopic and electrophysiological techniques to simultaneously detect conformational changes and ionic currents across the membrane. Since its introduction, patch-clamp fluorometry has been responsible for invaluable advances in our knowledge of ion channel biophysics. Over the years, the technique has been applied to many different ion channel families to address several biophysical questions with a variety of spectroscopic approaches and electrophysiological configurations. This review illustrates the strength and the flexibility of patch-clamp fluorometry, demonstrating its potential as a tool for future research. PMID:24655500

  14. Repair of Full-Thickness Defects in Alimentary Tract Wall With Patches of Expanded Polytetrafluoroethylene

    PubMed Central

    Oh, Daniel S.; Manning, Melanie M.; Emmanuel, Janson; Broyles, Stuart E.; Stone, H. Harlan

    2002-01-01

    Objectives To test the efficacy of patches of expanded polytetrafluoroethylene (ePTFE) for the repair of full-thickness defects in alimentary tract wall. Summary Background Data A recent report of successful replacement of duodenal wall with patches of ePTFE was met with skepticism and clearly warranted confirmation as well as evaluation in repair of other segments of the abdominal intestinal tract. Methods Defects of 4 cm2 were created in various segments of canine abdominal alimentary tract (stomach, duodenum, small bowel, and colon) as well as in bladder dome. For the duodenum in 13 dogs, three different ePTFE fabrications were used: CVX (cardiovascular), PDX (preclude dura membrane), and DLM (dual mesh plus). In repair of the other areas in six dogs, the PDX patch was used. When the animals were killed, both gross inspection of the parietes and tissue for histologic study became the basis for evaluation. Peritoneal and intraluminal cultures of the specific study viscera were also taken. Results There were no patch failures. Only six significant adhesions were noted in 3 of the 19 dogs. Serosal surface healing was complete without exception by 1 week in all animals. Patches of CVX and PDX had heaping mucosa at the margin of well-sealed patch edges in the study involving duodenum. However, the DLM patch had an undergrowth of mucosa with partial patch separation by 1 week, beginning patch extrusion into gut lumen at 3 weeks, and total separation of patch with complete mucosal repair at 6 weeks. The fate of the PDX patches at 6 weeks in stomach, small bowel, colon, and bladder was identical to what had been observed for the PDX patch in the duodenum. All peritoneal and bladder cultures had no growth, whereas the contents of the alimentary tract grew expected flora. Conclusions These observations suggest that ePTFE may well be an acceptable membrane for at least temporary replacement of full-thickness hollow viscus defects, even in the face of heavy bacterial

  15. Using Positive Youth Development to Predict Contribution and Risk Behaviors in Early Adolescence: Findings from the First Two Waves of the 4-H Study of Positive Youth Development

    ERIC Educational Resources Information Center

    Jelicic, Helena; Bobek, Deborah L.; Phelps, Erin; Lerner, Richard M.; Lerner, Jacqueline V.

    2007-01-01

    Theories of positive youth development (PYD) regard such development as bases of both community contributions and lessened likelihood of risk/problem behaviors. Using data from the 4-H Study of PYD, we tested these expectations by examining if PYD in Grade 5 predicted both youth contributions and risk behaviors and depression in Grade 6. Results…

  16. Patch-Based Segmentation with Spatial Consistency: Application to MS Lesions in Brain MRI

    PubMed Central

    Mechrez, Roey; Goldberger, Jacob; Greenspan, Hayit

    2016-01-01

    This paper presents an automatic lesion segmentation method based on similarities between multichannel patches. A patch database is built using training images for which the label maps are known. For each patch in the testing image, k similar patches are retrieved from the database. The matching labels for these k patches are then combined to produce an initial segmentation map for the test case. Finally an iterative patch-based label refinement process based on the initial segmentation map is performed to ensure the spatial consistency of the detected lesions. The method was evaluated in experiments on multiple sclerosis (MS) lesion segmentation in magnetic resonance images (MRI) of the brain. An evaluation was done for each image in the MICCAI 2008 MS lesion segmentation challenge. Results are shown to compete with the state of the art in the challenge. We conclude that the proposed algorithm for segmentation of lesions provides a promising new approach for local segmentation and global detection in medical images. PMID:26904103

  17. Boolean Operations with Prism Algebraic Patches.

    PubMed

    Bajaj, Chandrajit; Paoluzzi, Alberto; Portuesi, Simone; Lei, Na; Zhao, Wenqi

    2008-01-01

    In this paper we discuss a symbolic-numeric algorithm for Boolean operations, closed in the algebra of curved polyhedra whose boundary is triangulated with algebraic patches (A-patches). This approach uses a linear polyhedron as a first approximation of both the arguments and the result. On each triangle of a boundary representation of such linear approximation, a piecewise cubic algebraic interpolant is built, using a C(1)-continuous prism algebraic patch (prism A-patch) that interpolates the three triangle vertices, with given normal vectors. The boundary representation only stores the vertices of the initial triangulation and their external vertex normals. In order to represent also flat and/or sharp local features, the corresponding normal-per-face and/or normal-per-edge may be also given, respectively. The topology is described by storing, for each curved triangle, the two triples of pointers to incident vertices and to adjacent triangles. For each triangle, a scaffolding prism is built, produced by its extreme vertices and normals, which provides a containment volume for the curved interpolating A-patch. When looking for the result of a regularized Boolean operation, the 0-set of a tri-variate polynomial within each such prism is generated, and intersected with the analogous 0-sets of the other curved polyhedron, when two prisms have non-empty intersection. The intersection curves of the boundaries are traced and used to decompose each boundary into the 3 standard classes of subpatches, denoted in, out and on. While tracing the intersection curves, the locally refined triangulation of intersecting patches is produced, and added to the boundary representation. PMID:21516262

  18. Lightweight Material Patches Allow for Quick Repairs

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Cornerstone Research Group Inc., of Dayton, Ohio, has been the recipient of 16 Small Business Innovation Research (SBIR) contracts with NASA with a variety of different focuses, including projects like creating inflatable structures for radio frequency antennas and, most recently, healable polymer matrix composites for future space vehicles. One of its earlier SBIR contracts, with Kennedy Space Center, led to the development of a new type of structural patch for a variety of consumer uses: Rubbn Repair, for automotive uses; and Rec Repair for the outdoors and adventure market. Both are flexible, heat-activated structural patches.

  19. Monoamine oxidase inhibitory activity of 2-aryl-4H-chromen-4-ones.

    PubMed

    Nayak, Badavath Vishnu; Ciftci-Yabanoglu, S; Bhakat, Soumendranath; Timiri, Ajay Kumar; Sinha, Barij N; Ucar, G; Soliman, Mahmoud E S; Jayaprakash, Venkatesan

    2015-02-01

    A series of twenty 2-aryl-4H-chromen-4-one (flavones) derivatives (3a-3s) were synthesized and tested for hMAO inhibitory activity. Fifteen compounds (3a, 3c, 3e-3h, 3j-3p, 3r, 3s) were found to be selective towards MAO-B, while 3d was selective towards MAO-A, and 3b, 3i and 3q were non-selective. Experimental Selectivity Index for MAO-B ranges from 2.0 (3g, 3p) to 30.0 (3j). Compound 3j, which is carrying 3,4-di-OMeC6H3 groups at R position on the molecule, was found to be potent MAO-B inhibitor amongst the fifteen with Ki value for MAO-B of 0.16±0.01 μM comparable to that of standard drug, Selegiline (Ki for MAO-B is 0.16±0.01 μM). Compound 3j also appeared as the most selective MAO-B inhibitor according to its best selectivity index (30.0), which is comparable to that of Selegiline (SIMAO-B=35.0). Molecular docking and molecular dynamics simulation studies were carried out using Autodock-4.0 and Amber12 to understand the molecular level interaction and energy relation of MAO isoforms with selective inhibitors (3d and 3j). Simulation results are in good agreement with the experimental results. Leads identified may further be explored to develop potent isoform specific inhibitors of MAO. PMID:25506816

  20. The lta4h Locus Modulates Susceptibility to Mycobacterial Infection in Zebrafish and Humans

    PubMed Central

    Tobin, David M.; Vary, Jay C.; Ray, John P.; Walsh, Gregory S.; Dunstan, Sarah J.; Bang, Nguyen D.; Hagge, Deanna A.; Khadge, Saraswoti; King, Mary-Claire; Hawn, Thomas R.; Moens, Cecilia B.; Ramakrishnan, Lalita

    2010-01-01

    SUMMARY Exposure to Mycobacterium tuberculosis produces varied early outcomes, ranging from resistance to infection to progressive disease. Here we report results from a forward genetic screen in zebrafish larvae that identify multiple mutant classes with distinct patterns of innate susceptibility to Mycobacterium marinum. A hypersusceptible mutant maps to the lta4h locus encoding leukotriene A4 hydrolase, which catalyzes the final step in the synthesis of leukotriene B4 (LTB4), a potent chemoattractant and proinflammatory eicosanoid. lta4h mutations confer hypersusceptibility independent of LTB4 reduction, by redirecting eicosanoid substrates to anti-inflammatory lipoxins. The resultant anti-inflammatory state permits increased mycobacterial proliferation by limiting production of tumor necrosis factor. In humans, we find that protection from both tuberculosis and multibacillary leprosy is associated with heterozygosity for LTA4H polymorphisms that have previously been correlated with differential LTB4 production. Our results suggest conserved roles for balanced eicosanoid production in vertebrate resistance to mycobacterial infection. PMID:20211140

  1. Adult volunteerism in Pennsylvania 4-H natural resources programs for youth

    NASA Astrophysics Data System (ADS)

    Smith, Sanford Sherrick

    2001-07-01

    Pennsylvania's 4-H Youth Development Program relies on adult volunteers to reach youth with educational information and opportunities. Finding adults willing to do this volunteer work is challenging. This study looks at the current status of adult volunteerism with natural resources 4-H projects, and seeks to understand potential volunteers. The literature has much to offer in regards to general volunteer trends, management, motivations, and task preferences; however, few studies focus on volunteers in natural resources or environmental education. A telephone survey conducted with county 4-H agents revealed that only 3.2% of Pennsylvania's 4-H volunteers work with natural resources projects in 56 out of 67 counties, and that very few volunteers have any formal background in natural resources. Semi-structured interviews with 41 adult volunteers currently working with natural resources projects explored volunteer demographics, history, program design preferences, and ideas for seeking more volunteers. Findings from the telephone survey and the semi-structured interviews were used to generate a mail survey with large, random samples from three population groups: (1) 4-H Volunteers, (2) 4-H Parents, and (3) Natural Resources Professionals. Confidence with youth and subject matter, and adult willingness to volunteer was explored for each of the groups in relation to background, demographic characteristics, motivational needs, past and present volunteer activity, personal interests, and program design importance. Natural resources subject matter confidence was shown to be the most significant variable determining willingness to volunteer for all three groups. The variables that contributed to subject matter and youth confidence varied for each population. Key variables effecting willingness to volunteer included outdoor activity level, personal interest in natural resources, the need to fulfill feelings of social responsibility, and confidence with youth. Program design

  2. Synthesis, antifungal activity and docking study of 2-amino-4H-benzochromene-3-carbonitrile derivatives

    NASA Astrophysics Data System (ADS)

    Mirjalili, BiBi Fatemeh; Zamani, Leila; Zomorodian, Kamiar; Khabnadideh, Soghra; Haghighijoo, Zahra; Malakotikhah, Zahra; Ayatollahi Mousavi, Seyyed Amin; Khojasteh, Shaghayegh

    2016-07-01

    Pathogenic fungi are associated with diseases ranging from simple dermatosis to life-threatening infections, particularly in immunocompromised patients. During the past two decades, resistance to established antifungal drugs has increased dramatically and has made it crucial to identify novel antimicrobial compounds. Here, we selected 12 new compounds of 2-amino-4H-benzochromene-3-carbonitrile drivetives (C1-C12) for synthesis by using nano-TiCl4.SiO2 as efficient and green catalyst, then nine of synthetic compounds were evaluated against different species of fungi, positive gram and negative gram of bacteria. Standard and clinical strains of antibiotics sensitive and resistant fungi and bacteria were cultured in appropriate media. Biological activity of the 2-amino-4H-benzochromene-3-carbonitrile derivatives against fungi and bacteries were estimated by the broth micro-dilution method as recommended by clinical and laboratory standard institute (CLSI). In addition minimal fangicidal and bactericial concenteration of the compounds were also determined. Considering our results showed that compound 2-amino-4-(4-methyl benzoate)-4H-benzo[f]chromen-3-carbonitrile (C9) had the most antifungal activity against Aspergillus clavatus, Candida glabarata, Candida dubliniensis, Candida albicans and Candida tropicalis at concentrations ranging from 8 to ≤128 μg/mL. Also compounds 2-amino-4-(3,4-dimethoxyphenyl)-4H-benzo[f]chromen-3-carbonitrile (C4) and 2-amino-4-(4-isopropylphenyl)-4H-benzo[f]chromen-3-carbonitrile (C3) had significant inhibitory activities against Epidermophyton floccosum following 2-amino-4-(4-methylbenzoate)-4H-benzo[f]chromen-3-carbonitrile (C9), respectively. Docking simulation was performed to insert compounds C3, C4 and C9 in to CYP51 active site to determine the probable binding model.

  3. Synthesis, antifungal activity and docking study of 2-amino-4H-benzochromene-3-carbonitrile derivatives

    NASA Astrophysics Data System (ADS)

    Mirjalili, BiBi Fatemeh; Zamani, Leila; Zomorodian, Kamiar; Khabnadideh, Soghra; Haghighijoo, Zahra; Malakotikhah, Zahra; Ayatollahi Mousavi, Seyyed Amin; Khojasteh, Shaghayegh

    2016-07-01

    Pathogenic fungi are associated with diseases ranging from simple dermatosis to life-threatening infections, particularly in immunocompromised patients. During the past two decades, resistance to established antifungal drugs has increased dramatically and has made it crucial to identify novel antimicrobial compounds. Here, we selected 12 new compounds of 2-amino-4H-benzochromene-3-carbonitrile drivetives (C1-C12) for synthesis by using nano-TiCl4.SiO2 as efficient and green catalyst, then nine of synthetic compounds were evaluated against different species of fungi, positive gram and negative gram of bacteria. Standard and clinical strains of antibiotics sensitive and resistant fungi and bacteria were cultured in appropriate media. Biological activity of the 2-amino-4H-benzochromene-3-carbonitrile derivatives against fungi and bacteries were estimated by the broth micro-dilution method as recommended by clinical and laboratory standard institute (CLSI). In addition minimal fangicidal and bactericial concenteration of the compounds were also determined. Considering our results showed that compound 2-amino-4-(4-methyl benzoate)-4H-benzo[f]chromen-3-carbonitrile (C9) had the most antifungal activity against Aspergillus clavatus, Candida glabarata, Candida dubliniensis, Candida albicans and Candida tropicalis at concentrations ranging from 8 to ≤128 μg/mL. Also compounds 2-amino-4-(3,4-dimethoxyphenyl)-4H-benzo[f]chromen-3-carbonitrile (C4) and 2-amino-4-(4-isopropylphenyl)-4H-benzo[f]chromen-3-carbonitrile (C3) had significant inhibitory activities against Epidermophyton floccosum following 2-amino-4-(4-methylbenzoate)-4H-benzo[f]chromen-3-carbonitrile (C9), respectively. Docking simulation was performed to insert compounds C3, C4 and C9 in to CYP51 active site to determine the probable binding model.

  4. Transition metal swift heavy ion implantation on 4H-SiC

    NASA Astrophysics Data System (ADS)

    Ali, A. Ashraf; Kumar, J.; Ramakrishnan, V.; Asokan, K.

    2016-03-01

    This work reports on the realization of Quantum Ring (QR) and Quantum Dot (QD) like structures on 4H-SiC through SHI implantation and on their Raman studies. 4H-SiC is SHI implanted with Transition Metal (TM) Ni ion at different fluences. It is observed that a vibrational mode emerges as the result of Ni ion implantation. The E2 (TO) and the A1 (LO) are suppressed as the fluence increases. In this paper Raman and AFM studies have been performed at room temperature and the queer anomalies are addressed so new devices can be fabricated.

  5. Crystal and molecular structure of 2,4,4-trisubstituted 5-amino-4 H-imidazoles

    NASA Astrophysics Data System (ADS)

    Bellanato, J.; Avendaño, C.; Ramos, M. T.; Smith-Verdier, P.; Florencio, F.; Garcia-Blanco, S.

    Three 5-amino-4 H-imidazole derivatives 2(2-pyridyl) and 2-ethoxycarbonyl-4,4-pentamethylene-5-amino-and 2(2-pyridyl)-4,4-dimethyl-5(2-pyridylamino)4 H-imidazoles have been studied by i.r. and Raman spectroscopy. The crystal structure of one has been determined by X-ray diffraction. The tautomeric amino-imino equilibrium in different working conditions is also studied from spectroscopic data. The amino and the unconjugated imino forms are characterized.

  6. Analysis of Surface Defects on the Reverse Characteristics of 4H-SiC JBS Diode

    NASA Astrophysics Data System (ADS)

    Katsuno, Takashi; Watanabe, Yukihiko; Fujiwara, Hirokazu; Konishi, Masaki; Yamamoto, Takeo; Endo, Takeshi; Ishiko, Masayasu

    The good relations between the reverse characteristics of 4H-SiC JBS diodes and the surface defects were obtained. The reverse characteristics of 4H-SiC JBS diodes were categorized in three groups as follows: (A) low blocking voltage, (B) high leakage current and (C) low leakage current. The groups of (A) and (B) were caused by the existences of the micropipe and small particles, and the carrot-like defects on the SiC surfaces, respectively. In group (C), there was no defect on the surfaces observed by the optical microscope. The structure of carrot-like defect was analyzed by the cathode-luminescence and TEM.

  7. Managing for Motivation: Herzberg's Motivation-Hygiene Theory and Its Application to 4-H Leadership. National Intern Report.

    ERIC Educational Resources Information Center

    Freeman, Walter J.

    A study examined the organizational factors contributing to the motivation of 4-H volunteer leaders. A modified form of Herzberg's Motivation-Hygiene Theory served as the research design of the study. A total of 149 4-H leaders were interviewed regarding thirteen job factors: recognition; personal growth; relationships with other 4-H leaders,…

  8. Current Practices for Training Staff to Accommodate Youth with Special Health Care Needs in the 4-H Camp Setting

    ERIC Educational Resources Information Center

    Mouton, Lauren; Bruce, Jacklyn

    2013-01-01

    The theory of inclusion is the foundation for the study reported here; inclusion is a focus not only of formal education, but also of nonformal educational settings such as 4-H. Ideally, 4-H camps are designed to serve youth of all backgrounds and abilities. By accommodating youth with special health care needs, 4-H camps are effectively meeting…

  9. Maine 4-H Afterschool Academy--A Professional Development Opportunity for Out-of-School-Time Providers

    ERIC Educational Resources Information Center

    Lobley, Jennifer; Ouellette, Kristy L.

    2013-01-01

    The Maine 4-H Afterschool Academy trained 369 after-school and out of school time providers in 2011. This easy-to-adapt professional development opportunity used blended learning, a combination of in-person and Web-based opportunities. Providers successfully learned concepts and practical knowledge regarding 4-H, specifically 4-H Science. In…

  10. E-Learning for 4-H Volunteers: Who Uses It, and What Can We Learn from Them?

    ERIC Educational Resources Information Center

    Ouellette, Kristy L.; Lesmeister, Marilyn K.; Lobley, Jennifer; Gross, Kerry M.

    2014-01-01

    Orienting and training 4-H volunteers are critical to individuals and the organization. The two-part study reported here re-establishes the profile of the 4-H volunteer and evaluates both the format and content of e-Learning for 4-H Volunteers modules launched in 2006. Volunteers from seven states perceived that online modules made learning more…

  11. Soil, Seeds, and the Pumpkin Patch!

    ERIC Educational Resources Information Center

    Phillips, Marianne; Vowell, Julie

    2013-01-01

    "Soil, Seeds, and the Pumpkin Patch!" is an integrated unit designed to provide elementary school teachers with ideas for using hands-on activities, fostering inquiry and valuable discussion, and using technology as a learning tool. This unit integrates science with language arts, mathematics, literature, and technology. During this unit, students…

  12. Juno Microwave Radiometer Patch Array Antennas

    NASA Technical Reports Server (NTRS)

    Chamberlain, N.; Chen, J.; Focardi, P.; Hodges, R.; Hughes, R.; Jakoboski, J.; Venkatesan, J.; Zawadzki, M.

    2009-01-01

    Juno is a mission in the NASA New Frontiers Program with the goal of significantly improving our understanding of the formation and structure of Jupiter. This paper discusses the modeling and measurement of the two patch array antennas. An overview of the antenna architecture, design and development at JPL is provided, along with estimates of performance and the results of measurements.

  13. Perturbation analysis for patch occupancy dynamics

    USGS Publications Warehouse

    Martin, Julien; Nichols, James D.; McIntyre, Carol L.; Ferraz, Goncalo; Hines, James E.

    2009-01-01

    Perturbation analysis is a powerful tool to study population and community dynamics. This article describes expressions for sensitivity metrics reflecting changes in equilibrium occupancy resulting from small changes in the vital rates of patch occupancy dynamics (i.e., probabilities of local patch colonization and extinction). We illustrate our approach with a case study of occupancy dynamics of Golden Eagle (Aquila chrysaetos) nesting territories. Examination of the hypothesis of system equilibrium suggests that the system satisfies equilibrium conditions. Estimates of vital rates obtained using patch occupancy models are used to estimate equilibrium patch occupancy of eagles. We then compute estimates of sensitivity metrics and discuss their implications for eagle population ecology and management. Finally, we discuss the intuition underlying our sensitivity metrics and then provide examples of ecological questions that can be addressed using perturbation analyses. For instance, the sensitivity metrics lead to predictions about the relative importance of local colonization and local extinction probabilities in influencing equilibrium occupancy for rare and common species.

  14. Multimode Broad-Band Patch Antennas

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    2003-01-01

    Microstrip patch antennas of a proposed type would be tunable over broad wavelength ranges. These antennas would be attractive for use in a variety of microwave communication systems in which there are requirements for transmission and/or reception at multiple, widely separated frequencies. Prior efforts to construct tunable microstrip patch antennas have involved integration of microstrip circuitry with, variously, ferrite films with magneticfield tuning, solid-state electronic tuning devices, or piezoelectric tuning actuators. Those efforts have been somewhat successful, but have yielded tuning ranges of 20 percent and smaller much smaller than needed in typical practical cases. Like prior microstrip patch antennas (both tunable and non-tunable), the proposed antennas would have instantaneous bandwidths of about 1 percent of their nominal or resonance frequencies. However, these would be tunable over much broader frequency ranges as much as several octaves, depending on specific designs. They could be fabricated relatively simply and inexpensively by use of conventional photolithography, and without need for integration with solid-state electronic or piezoelectric control devices. An antenna as proposed (see figure) would include a microstrip patch radiating element on a thin ferroelectric film on a semiconductor substrate with a ground-plane conductor on the underside of the substrate. The ferroelectric film could be, for example, SrTiO3 with a thickness of the order of 1 or 2 micrometers.

  15. Structure, ferroelectric ordering, and semiempirical quantum calculations of lanthanide based metal-organic framework: [Nd(C4H5O6)(C4H4O6)][3H2O

    NASA Astrophysics Data System (ADS)

    Ahmad, Bhat Zahoor; Want, Basharat

    2016-04-01

    We investigate the structure and ferroelectric behavior of a lanthanide based metal-organic framework (MOF), [Nd(C4H5O6)(C4H4O6)][3H2O]. X-ray crystal structure analyses reveal that it crystallizes in the P41212 space group with Nd centres, coordinated by nine oxygen atoms, forming a distorted capped square antiprismatic geometry. The molecules, bridged by tartrate ligands, form a 2D chiral structure. The 2D sheets are further linked into a 3D porous framework via strong hydrogen-bonding scheme (O-H…O ≈ 2.113 Å). Dielectric studies reveal two anomalies at 295 K and 185 K. The former is a paraelectric-ferroelectric transition, and the later is attributed to the freezing down of the motion of the hydroxyl groups. The phase transition is of second order, and the spontaneous polarization in low temperature phase is attributed to the ordering of protons of hydroxyl groups. The dielectric nonlinearity parameters have been calculated using Landau- Devonshire phenomenological theory. In addition, the most recent semiempirical models, Sparkle/PM7, Sparkle/RM1, and Sparkle/AM1, are tested on the present system to assay the accuracy of semiempirical quantum approaches to predict the geometries of solid MOFs. Our results show that Sparkle/PM7 model is the most accurate to predict the unit cell structure and coordination polyhedron geometry. The semiempirical methods are also used to calculate different ground state molecular properties.

  16. A method to visualize transdermal nickel permeation in mouse skin using a nickel allergy patch

    PubMed Central

    Sugiyama, Tomoko; Uo, Motohiro; Wada, Takahiro; Hongo, Toshio; Omagari, Daisuke; Komiyama, Kazuo; Oikawa, Masakazu; Kusama, Mikio; Mori, Yoshiyuki

    2015-01-01

    Metal patch test is often used in clinical settings when metal-induced contact dermatitis is suspected. However, the transdermal permeation behavior of metal ions from the patch test remains unclear. Current patch tests using high concentrations of metal salt solutions have some side effects, e.g. acute skin reactions to high concentrations of metal salt. To resolve these, estimating metal ion transdermal permeation is wished. In this study, synchrotron radiation X-ray fluorescence (SR-XRF) and micro-focused particle-induced X-ray emission (micro-PIXE) were used to visualize the time-dependent Ni permeation in mouse skin. The cross-sectional diffusion of Ni was visualized in a time-dependent manner. Our results indicate that maximum Ni permeation occurs after 24 h of patch treatment, and the permeated Ni content was high in the epidermis and spread into the dermis beyond the basal layer. This method may be useful to determine the appropriate solution concentration and duration of administration for the patch test. PMID:26484550

  17. A method to visualize transdermal nickel permeation in mouse skin using a nickel allergy patch.

    PubMed

    Sugiyama, Tomoko; Uo, Motohiro; Wada, Takahiro; Hongo, Toshio; Omagari, Daisuke; Komiyama, Kazuo; Oikawa, Masakazu; Kusama, Mikio; Mori, Yoshiyuki

    2015-01-01

    Metal patch test is often used in clinical settings when metal-induced contact dermatitis is suspected. However, the transdermal permeation behavior of metal ions from the patch test remains unclear. Current patch tests using high concentrations of metal salt solutions have some side effects, e.g. acute skin reactions to high concentrations of metal salt. To resolve these, estimating metal ion transdermal permeation is wished. In this study, synchrotron radiation X-ray fluorescence (SR-XRF) and micro-focused particle-induced X-ray emission (micro-PIXE) were used to visualize the time-dependent Ni permeation in mouse skin. The cross-sectional diffusion of Ni was visualized in a time-dependent manner. Our results indicate that maximum Ni permeation occurs after 24 h of patch treatment, and the permeated Ni content was high in the epidermis and spread into the dermis beyond the basal layer. This method may be useful to determine the appropriate solution concentration and duration of administration for the patch test. PMID:26484550

  18. Patch occupancy, number of individuals and population density of the Marbled White in a changing agricultural landscape

    NASA Astrophysics Data System (ADS)

    Lenda, Magdalena; Skórka, Piotr

    2010-09-01

    Metapopulation theory predicts the occurrence of animals in habitat patches. In this paper, we tested predictions based on this theory, including effects of spatial autocorrelation, to describe factors affecting the presence, local number of individuals and density of the Marbled White butterfly Melanargia galathea in habitat patches spread across the agricultural landscape of southern Poland. This agricultural landscape has undergone significant changes in recent decades due to the country's political transformation and is currently characterized by a large proportion of fallow (abandoned) land. We compared 48 occupied habitat patches with 60 unoccupied ones. Positive spatial autocorrelation was found in the number and density of individuals in habitat patches. The probability of patch occupancy was higher for patches that were larger, had a higher proportion of edges, were located closer to the nearest neighbouring local population and to the nearest piece of fallow, contained a smaller area of cut grass, and also had more nectar resources. The number of Marbled Whites in habitat patches was positively related to the patch area, the distance to the nearest fallow and the abundance of nectar resources, but was negatively related to the density of shrubs. The density of individuals was positively related to abundance of flowers, proportion of edge in a patch and distance to the nearest fallow, but it was negatively related to patch area, vegetation height and grass cover. These results indicate that recent land-use changes in agricultural landscapes have had both positive and negative effects on the presence and local number of individuals and density of the Marbled White. These changes affect the metapopulation of the species through changes in habitat quality and landscape connectivity in the area surrounding habitat patches.

  19. Multi-Band Miniaturized Patch Antennas for a Compact, Shielded Microwave Breast Imaging Array

    PubMed Central

    Aguilar, Suzette M.; Al-Joumayly, Mudar A.; Burfeindt, Matthew J.; Behdad, Nader; Hagness, Susan C.

    2014-01-01

    We present a comprehensive study of a class of multi-band miniaturized patch antennas designed for use in a 3D enclosed sensor array for microwave breast imaging. Miniaturization and multi-band operation are achieved by loading the antenna with non-radiating slots at strategic locations along the patch. This results in symmetric radiation patterns and similar radiation characteristics at all frequencies of operation. Prototypes were fabricated and tested in a biocompatible immersion medium. Excellent agreement was obtained between simulations and measurements. The trade-off between miniaturization and radiation efficiency within this class of patch antennas is explored via a numerical analysis of the effects of the location and number of slots, as well as the thickness and permittivity of the dielectric substrate, on the resonant frequencies and gain. Additionally, we compare 3D quantitative microwave breast imaging performance achieved with two different enclosed arrays of slot-loaded miniaturized patch antennas. Simulated array measurements were obtained for a 3D anatomically realistic numerical breast phantom. The reconstructed breast images generated from miniaturized patch array data suggest that, for the realistic noise power levels assumed in this study, the variations in gain observed across this class of multi-band patch antennas do not significantly impact the overall image quality. We conclude that these miniaturized antennas are promising candidates as compact array elements for shielded, multi-frequency microwave breast imaging systems. PMID:25392561

  20. Patching vs Atropine to Treat Amblyopia in Children Aged 7 to 12 Years: A Randomized Trial

    PubMed Central

    2008-01-01

    Objective To compare patching with atropine eye drops in the treatment of moderate amblyopia (20/40 -20/100) in children age 7 to 12 years. Methods In a randomized multi-center clinical trial, 193 children with amblyopia were randomized to weekend atropine or patching 2 hours per day of the sound eye. Main Outcome Measure Masked assessment of amblyopic eye visual acuity using the EETDRS testing protocol at 17 weeks. Results At 17 weeks, visual acuity had improved from baseline by an average of 7.6 letters in the atropine group and 8.6 letters in the patching group. The mean difference (patching minus atropine) between groups adjusted for baseline acuity was 1.2 letters (ends of complementary 1-sided 95% confidence intervals for noninferiority = -0.7 and +3.1 letters). Based on the confidence intervals this difference met the pre-specified definition for equivalence (ends of confidence intervals <5 letters). Amblyopic eye visual acuity was 20/25 or better in 15 subjects (17%) in the atropine group and 20 subjects (24%) in the patching group (difference = 7%, 95% confidence interval = -3% to 17%). Conclusions Treatment with atropine or patching leads to similar degrees of improvement in 7 to 12 year old children with moderate amblyopia. About 1 in 5 achieves 20/25 or better visual acuity in the amblyopic eye. Application to Clinical Practice Treatment of older children with unilateral amblyopia. PMID:19064841

  1. An Active Patch Model for Real World Texture and Appearance Classification

    PubMed Central

    Mao, Junhua; Zhu, Jun; Yuille, Alan L.

    2014-01-01

    This paper addresses the task of natural texture and appearance classification. Our goal is to develop a simple and intuitive method that performs at state of the art on datasets ranging from homogeneous texture (e.g., material texture), to less homogeneous texture (e.g., the fur of animals), and to inhomogeneous texture (the appearance patterns of vehicles). Our method uses a bag-of-words model where the features are based on a dictionary of active patches. Active patches are raw intensity patches which can undergo spatial transformations (e.g., rotation and scaling) and adjust themselves to best match the image regions. The dictionary of active patches is required to be compact and representative, in the sense that we can use it to approximately reconstruct the images that we want to classify. We propose a probabilistic model to quantify the quality of image reconstruction and design a greedy learning algorithm to obtain the dictionary. We classify images using the occurrence frequency of the active patches. Feature extraction is fast (about 100 ms per image) using the GPU. The experimental results show that our method improves the state of the art on a challenging material texture benchmark dataset (KTH-TIPS2). To test our method on less homogeneous or inhomogeneous images, we construct two new datasets consisting of appearance image patches of animals and vehicles cropped from the PASCAL VOC dataset. Our method outperforms competing methods on these datasets. PMID:25531013

  2. Experimental manipulation shows that the white wing patch in collared flycatchers is a male sexual ornament

    PubMed Central

    de Heij, Maaike E; Gustafsson, Lars; Brommer, Jon E

    2011-01-01

    Descriptive analysis suggests that a conspicuous white wing patch in dichromatic (black and white) pied and collared flycatchers is under sexual selection. Here, we use an experimental approach to test whether this trait is indeed the target of selection. We caught 100 collared flycatcher Ficedula albicollis males soon after their arrival on the breeding site. We reduced (blackened) part of the white wing patch in half of these males and recorded their mating success and within and extra-pair offspring production. Reduction of the size of the white wing patch lowered a male's probability to attract a secondary social female, but not a primary female. However, primary females paired to males with a reduced wing patch were smaller (in tarsus), suggesting that male choice of partner or female–female competition over mates occurs in this species. The probability of pairing with a primary female (but not other components of male reproductive success) declined with arrival time (proxied by the date of capture). Males with a reduced wing patch size tended to sire less extra-pair offspring, although this relationship was reversed in one of the three study plots, suggesting that mating dynamics are context dependent. While our findings show that wing patch size is the target of sexual selection, the pathways and the strength of selection on this ornament differed markedly from a previous descriptive study. Nonexperimental studies of sexual selection in the wild may overestimate its importance because male fitness and ornamentation both depend positively on environmental conditions. PMID:22393521

  3. Predator-Prey Interactions Shape Thermal Patch Use in a Newt Larvae-Dragonfly Nymph Model

    PubMed Central

    Gvoždík, Lumír; Černická, Eva; Van Damme, Raoul

    2013-01-01

    Thermal quality and predation risk are considered important factors influencing habitat patch use in ectothermic prey. However, how the predator’s food requirement and the prey’s necessity to avoid predation interact with their respective thermoregulatory strategies remains poorly understood. The recently developed ‘thermal game model’ predicts that in the face of imminent predation, prey should divide their time equally among a range of thermal patches. In contrast, predators should concentrate their hunting activities towards warmer patches. In this study, we test these predictions in a laboratory setup and an artificial environment that mimics more natural conditions. In both cases, we scored thermal patch use of newt larvae (prey) and free-ranging dragonfly nymphs (predators). Similar effects were seen in both settings. The newt larvae spent less time in the warm patch if dragonfly nymphs were present. The patch use of the dragonfly nymphs did not change as a function of prey availability, even when the nymphs were starved prior to the experiment. Our behavioral observations partially corroborate predictions of the thermal game model. In line with asymmetric fitness pay-offs in predator-prey interactions (the ‘life-dinner’ principle), the prey’s thermal strategy is more sensitive to the presence of predators than vice versa. PMID:23755175

  4. Effects of slits in a patch of omnidirectional Lamb-wave MPT on the transducer output

    NASA Astrophysics Data System (ADS)

    Kim, Kiyean; Lee, Hyung Jin; Lee, Joo Kyung; Kim, Yoon Young

    2016-03-01

    An omnidirectional Lamb-wave magnetostrictive patch transducer (MPT) uses a thin circular magnetostrictive patch excited by the axisymmetric turns of a plane coil placed over it. Since the dynamic magnetic field applied by the coil induces an eddy current only on the top surface due to the skin effect, the mechanical deformation in the patch is confined only near the surface, considerably limiting the transducer output power. This study shows that if a radial slit is introduced in the patch, the circular flow of the eddy current on the top surface only becomes broken, and thus the eddy current flows on both the top and bottom surfaces. As a consequence, there is a substantial increase in the dynamic magnetic field in the patch and, in turn, an increased transducer output power. Interestingly, the material type, either metallic or nonmetallic, of the test waveguide plate affects the magnitude of the eddy current near the bottom surface and the overall magnetic field. If the number of slits is over a certain number, say, 8, and the slits are symmetrically made in the patch, the omni-directivity of the resulting MPT is virtually ensured. Finally, the present findings are verified both numerically and experimentally.

  5. Multi-Band Miniaturized Patch Antennas for a Compact, Shielded Microwave Breast Imaging Array.

    PubMed

    Aguilar, Suzette M; Al-Joumayly, Mudar A; Burfeindt, Matthew J; Behdad, Nader; Hagness, Susan C

    2013-12-18

    We present a comprehensive study of a class of multi-band miniaturized patch antennas designed for use in a 3D enclosed sensor array for microwave breast imaging. Miniaturization and multi-band operation are achieved by loading the antenna with non-radiating slots at strategic locations along the patch. This results in symmetric radiation patterns and similar radiation characteristics at all frequencies of operation. Prototypes were fabricated and tested in a biocompatible immersion medium. Excellent agreement was obtained between simulations and measurements. The trade-off between miniaturization and radiation efficiency within this class of patch antennas is explored via a numerical analysis of the effects of the location and number of slots, as well as the thickness and permittivity of the dielectric substrate, on the resonant frequencies and gain. Additionally, we compare 3D quantitative microwave breast imaging performance achieved with two different enclosed arrays of slot-loaded miniaturized patch antennas. Simulated array measurements were obtained for a 3D anatomically realistic numerical breast phantom. The reconstructed breast images generated from miniaturized patch array data suggest that, for the realistic noise power levels assumed in this study, the variations in gain observed across this class of multi-band patch antennas do not significantly impact the overall image quality. We conclude that these miniaturized antennas are promising candidates as compact array elements for shielded, multi-frequency microwave breast imaging systems. PMID:25392561

  6. Relationships of habitat patch size to predator community and survival of duck nests

    USGS Publications Warehouse

    Sovada, M.A.; Zicus, M.C.; Greenwood, R.J.; Rave, D.P.; Newton, W.E.; Woodward, R.O.; Beiser, J.A.

    2000-01-01

    We studied duck nest success and predator community composition in relation to size of discrete patches of nesting cover in the Prairie Pothole Region (PPR) of the United States in 1993-95. We focused on nests in uplands that were seeded to perennial grasses and forbs and enrolled in the Conservation Reserve Program (CRP) in Minnesota, North Dakota, and South Dakota. We estimated daily survival rates (DSRs) of upland duck nests and indices of activity for red foxes (Vulpes vulpes), coyotes (Canis latrans), American badgers (Taxidea taxus), striped skunks (Mephitis mephitis), and Franklin's ground squirrels (Spermophilus franklinii), and related these variables to habitat patch size. The effect of patch size (small vs. large) on estimated annual mean DSR was dependent on date of nest initiation (early vs. late) and year. Examination of within-year comparisons for early and late nests suggested that DSR was generally greater in larger habitat patches. Activity indices for the 5 mammalian nest predators were influenced differently by year, location, and patch size. Activity indices of the red fox were greatest in small patches. Coyote indices were the most inconsistent, demonstrating a year X location X patch size interaction. Activity indices of the striped skunk and American badger varied only among years. Franklin's ground squirrel indices were affected by study area location, with higher indices in the southeast than the northwest. Red fox activity was weakly correlated with that of the striped skunk and coyote. Although a positive relationship between habitat patch size and nest success probably exists, we believe the experiment to fully test this hypothesis will continue to be elusive.

  7. PatchSurfers: Two methods for local molecular property-based binding ligand prediction.

    PubMed

    Shin, Woong-Hee; Bures, Mark Gregory; Kihara, Daisuke

    2016-01-15

    Protein function prediction is an active area of research in computational biology. Function prediction can help biologists make hypotheses for characterization of genes and help interpret biological assays, and thus is a productive area for collaboration between experimental and computational biologists. Among various function prediction methods, predicting binding ligand molecules for a target protein is an important class because ligand binding events for a protein are usually closely intertwined with the proteins' biological function, and also because predicted binding ligands can often be directly tested by biochemical assays. Binding ligand prediction methods can be classified into two types: those which are based on protein-protein (or pocket-pocket) comparison, and those that compare a target pocket directly to ligands. Recently, our group proposed two computational binding ligand prediction methods, Patch-Surfer, which is a pocket-pocket comparison method, and PL-PatchSurfer, which compares a pocket to ligand molecules. The two programs apply surface patch-based descriptions to calculate similarity or complementarity between molecules. A surface patch is characterized by physicochemical properties such as shape, hydrophobicity, and electrostatic potentials. These properties on the surface are represented using three-dimensional Zernike descriptors (3DZD), which are based on a series expansion of a 3 dimensional function. Utilizing 3DZD for describing the physicochemical properties has two main advantages: (1) rotational invariance and (2) fast comparison. Here, we introduce Patch-Surfer and PL-PatchSurfer with an emphasis on PL-PatchSurfer, which is more recently developed. Illustrative examples of PL-PatchSurfer performance on binding ligand prediction as well as virtual drug screening are also provided. PMID:26427548

  8. Children and their 4-H animal projects: How children use science in agricultural activity

    NASA Astrophysics Data System (ADS)

    Emo, Kenneth Roy

    Many children are introduced to science through informal educational programs. 4-H, an educational youth program, has a history of introducing scientific practices into agriculture. The purpose of this ethnographically-driven case study is to examine how science informs the actions of children raising market animals in a 4-H project. For two years the researcher collected data on 4-H children with market animal projects. Observations, interviews, and artifacts gathered are interpreted using the framework of activity theory. This study provides evidence for how the context of an activity system influences individual actions. Rules developed by the organization guide the actions of children to incorporate physical and psychological tools of science into their project to achieve the object: producing animals of proper weight and quality to be competitive in the county fair. Children learn the necessary actions from a community of practitioners through which expertise is distributed. Children's learning is demonstrated by the way their participation in their project changes with time, from receiving assistance from others to developing expertise in which they provide assistance to others. The strength of this educational experience is how children apply specific tools of science in ways that provide meaning and relevancy to their 4-H activity.

  9. More than Cows & Cooking: Newest Research Shows the Impact of 4-H.

    ERIC Educational Resources Information Center

    Astroth, Kirk A.; Haynes, George W.

    2002-01-01

    A Montana survey of 2,500 students' use of out-of-school time found that only 17% reported no involvement in out-of-school activities. 4-H participants were less likely to shoplift, steal, smoke cigarettes, ride with a drunk driver, or damage property. They were more likely to develop self-confidence and social competence, demonstrate leadership,…

  10. County Clustering for the California 4-H Youth Development Program: Impacts and Lessons Learned

    ERIC Educational Resources Information Center

    Subramaniam, Aarti; Dasher, Harry Steve; Young, Jane Chin

    2012-01-01

    In response to budgetary constraints, a new staffing structure, the Pilot Leadership Plan, was proposed for California's 4-H Youth Development Program. County clusters were formed, each led by a coordinator. The plan was piloted for 2 years to provide insight into how county clustering could support Extension staff to increase and enhance…

  11. 4-H Horticulture Project Activity Guides. Leader's Guide and Units 1-3.

    ERIC Educational Resources Information Center

    Illinois Univ., Urbana. Cooperative Extension Service.

    This document, concerning the 4-H horticulture project, includes a leader's guide and three youth activity guides. The leader's guide can be used to plan group project meetings that are both fun and educational. Activities can be adapted to various age groups. The leader's guide includes basic information for growing plants indoors and outdoors,…

  12. Promoting the Essential Elements of 4-H Youth Development through an Experiential Learning Model

    ERIC Educational Resources Information Center

    Meyer, Shelley; Jones, Kenneth R.

    2015-01-01

    The purpose of the project reported here was to apply Experiential Learning Theory to a context involving middle and high school aged youth while assessing the four concepts (belonging, mastery, independence, and generosity) in relation to the 4-H youth development essential elements. The conclusions of the project's evaluation suggest…

  13. 4-H Chickquest: Connecting Agri-Science with STEM Standards in Urban Schools

    ERIC Educational Resources Information Center

    Horton, Robert L.; Krieger, Jackie; Halasa, Katrina

    2013-01-01

    While young students are more capable of scientific inquiry than previously believed, elementary school teachers are often inexperienced in and lack confidence with teaching science. ChickQuest is a 4-H-created embryology curriculum for third-graders that meets Ohio state science standards, teaches STEM skills, and promotes ongoing interaction…

  14. Possession, Transportation, and Use of Firearms by Older Youth in 4-H Shooting Sports Programs

    ERIC Educational Resources Information Center

    White, David J.; Williver, S. Todd

    2014-01-01

    Thirty years ago we would think nothing of driving to school with a jackknife in our pocket or rifle in the gun rack. Since then, the practices of possessing, transporting, and using firearms have been limited by laws, rules, and public perception. Despite restrictions on youth, the Youth Handgun Safety Act does afford 4-H shooting sports members…

  15. 4-H Tractor Operator Program Teaches Employability Skills and Safety to Youth

    ERIC Educational Resources Information Center

    Barrett, Debra K.

    2013-01-01

    For Michigan State University Extension, the Berrien County 4-H Tractor Operator Program has provided tractor safety education to teens for over 30 years. The certification training satisfies current requirements for operation of a 20 PTO HP or greater agricultural tractor by 14- and 15-year-old youth employed on property "not" owned,…

  16. Stakeholder Satisfaction with a 4-H Extension Program for Five- to Eight-Year-Old Children.

    ERIC Educational Resources Information Center

    Scheer, Scott D.; Lafontaine, Kenneth R.

    1999-01-01

    A 4-H K-2 program was evaluated by 277 parents, 144 volunteers, and 44 extension agents. These stakeholders believed the program was beneficial and effective in improving children's life skills (self-esteem, making friends, making choices, learning and physical skills). (SK)

  17. Life Skill Development Related to Participation in 4-H Animal Science Projects.

    ERIC Educational Resources Information Center

    Ward, Carol Knowlton

    1996-01-01

    Alumni of 4-H animal science programs in New Jersey were surveyed (n=52). Participation had a positive influence on life skill development, especially "accepting responsibility." Experience with shows and judging was beneficial to public speaking/job interview skills. Although many were not in animal science careers, they enjoyed related hobbies.…

  18. A Beach and Dune Community. 4-H Marine Science. Member's Guide. Activity I. MSp 1.

    ERIC Educational Resources Information Center

    Auburn Univ., AL. Cooperative Extension Service.

    The investigation in this booklet is designed to provide 4-H members with opportunities to identify common plants and animals found on beaches and sand dunes and to determine the role of the plants and animals in this community. Learners are provided with a picture of a hypothetical beach and sand dune and a list of organisms (included in the…

  19. The Big E (Energy). 4-H Leader's Guide for Units 2 & 3.

    ERIC Educational Resources Information Center

    Caldwell, William; And Others

    This leader's guide is designed for units 2 and 3 of the Nebraska 4-H Energy Project. The goals of the project are to: (1) help young people understand energy problems related to life styles; (2) use energy resources carefully; (3) guide members in choosing their own energy alternatives; and (4) to enjoy together the challenges and creativity of…

  20. CareerSmarts. 4-H Mentoring Program. Agent's Handbook. Mentor's Handbook. Protege's Handbook.

    ERIC Educational Resources Information Center

    Locklear, Eddie L.

    The North Carolina 4-H CareerSmarts Program is designed to unite the public and private sectors to provide career education for young people. This packet contains three handbooks (for agents, proteges, and mentors) that explain the program and outline practical ways to conduct it. CareerSmarts consists of three phases. Phase one is conducted…

  1. Louisiana 4-H Seeds of Service School Gardens: A Descriptive View

    ERIC Educational Resources Information Center

    Cater, Melissa; Fox, Janet; Fletcher, Bobby Jr.

    2012-01-01

    Louisiana 4-H Seeds of Service School Gardens, a K-12 Learn and Serve Grant program, provides a descriptive view of how school gardens along with classroom instruction link curriculum to outdoor classrooms. The purpose of the process evaluation was to describe curriculum implementation fidelity, reach of the gardening program to participants, use…

  2. Bufexamac ameliorates LPS-induced acute lung injury in mice by targeting LTA4H.

    PubMed

    Xiao, Qiang; Dong, Ningning; Yao, Xue; Wu, Dang; Lu, Yanli; Mao, Fei; Zhu, Jin; Li, Jian; Huang, Jin; Chen, Aifang; Huang, Lu; Wang, Xuehai; Yang, Guangxiao; He, Guangyuan; Xu, Yong; Lu, Weiqiang

    2016-01-01

    Neutrophils play an important role in the occurrence and development of acute lung injury (ALI). Leukotriene B4 (LTB4), a hydrolysis product of epoxide leukotriene A4 (LTA4) catalyzed by LTA4 hydrolase (LTA4H), is one of the most potent chemoattractants for neutrophil. Bufexamac is a drug widely used as an anti-inflammatory agent on the skin, however, the mechanism of action is still not fully understood. In this study, we found bufexamac was capable of specifically inhibiting LTA4H enzymatic activity and revealed the mode of interaction of bufexamac and LTA4H using X-ray crystallography. Moreover, bufexamac significantly prevented the production of LTB4 in neutrophil and inhibited the fMLP-induced neutrophil migration through inhibition of LTA4H. Finally, bufexamac significantly attenuated lung inflammation as reflected by reduced LTB4 levels and weakened neutrophil infiltration in bronchoalveolar lavage fluid from a lipopolysaccharide-induced ALI mouse model. In summary, our study indicates that bufexamac acts as an inhibitor of LTB4 biosynthesis and may have potential clinical applications for the treatment of ALI. PMID:27126280

  3. Temperature Dependence of Attenuation of Coplanar Waveguide on 4H High Resistivity SIC Through 540C

    NASA Technical Reports Server (NTRS)

    Ponchak, G. E.; Schwartz, Z.; Alterovitz, S. A.; Downey, A. N.; Freeman, J. C.

    2003-01-01

    For the first time, the temperature and frequency dependence of the attenuation of a Coplanar Waveguide (CPW) on 4H, High Resistivity Sic substrate is reported. The low frequency attenuation increases by 2 dB/cm at 500 C and the high frequency attenuation increases by 3.3 dB/cm at 500 C compared to room temperature.

  4. The Value of 4-H Judging Teams--Missouri Dairy Judging Alumni Survey

    ERIC Educational Resources Information Center

    Deaver, Karla; Probert, Ted

    2016-01-01

    Former Missouri 4-H Dairy Judging Team members responded to a survey about life skills development and the value of the judging team experience. Results of the survey indicate that judging team experience was highly influential in the development of communication, public speaking, and presentation skills. Respondents also indicated that judging…

  5. Formation of low-temperature cirrus from H2SO4/H2O aerosol droplets.

    PubMed

    Bogdan, A; Molina, M J; Sassen, K; Kulmala, M

    2006-11-23

    We present experimental results obtained with a differential scanning calorimeter (DSC) that indicate the small ice particles in low-temperature cirrus clouds are not completely solid but rather coated with an unfrozen H2SO4/H2O overlayer. Our results provide a new look on the formation, development, and microphysical properties of low-temperature cirrus clouds. PMID:17107102

  6. Bufexamac ameliorates LPS-induced acute lung injury in mice by targeting LTA4H

    PubMed Central

    Xiao, Qiang; Dong, Ningning; Yao, Xue; Wu, Dang; Lu, Yanli; Mao, Fei; Zhu, Jin; Li, Jian; Huang, Jin; Chen, Aifang; Huang, Lu; Wang, Xuehai; Yang, Guangxiao; He, Guangyuan; Xu, Yong; Lu, Weiqiang

    2016-01-01

    Neutrophils play an important role in the occurrence and development of acute lung injury (ALI). Leukotriene B4 (LTB4), a hydrolysis product of epoxide leukotriene A4 (LTA4) catalyzed by LTA4 hydrolase (LTA4H), is one of the most potent chemoattractants for neutrophil. Bufexamac is a drug widely used as an anti-inflammatory agent on the skin, however, the mechanism of action is still not fully understood. In this study, we found bufexamac was capable of specifically inhibiting LTA4H enzymatic activity and revealed the mode of interaction of bufexamac and LTA4H using X-ray crystallography. Moreover, bufexamac significantly prevented the production of LTB4 in neutrophil and inhibited the fMLP-induced neutrophil migration through inhibition of LTA4H. Finally, bufexamac significantly attenuated lung inflammation as reflected by reduced LTB4 levels and weakened neutrophil infiltration in bronchoalveolar lavage fluid from a lipopolysaccharide-induced ALI mouse model. In summary, our study indicates that bufexamac acts as an inhibitor of LTB4 biosynthesis and may have potential clinical applications for the treatment of ALI. PMID:27126280

  7. Participant Comfort with and Application of Inquiry-Based Learning: Results from 4-H Volunteer Training

    ERIC Educational Resources Information Center

    Haugen, Heidi; Stevenson, Anne; Meyer, Rebecca L.

    2016-01-01

    This article explores how a one-time training designed to support learning transfer affected 4-H volunteers' comfort levels with the training content and how comfort levels, in turn, affected the volunteers' application of tools and techniques learned during the training. Results of a follow-up survey suggest that the training participants…

  8. Bio-Security Proficiencies Project for Beginning Producers in 4-H

    ERIC Educational Resources Information Center

    Smith, Martin H.; Meehan, Cheryl L.; Borba, John A.

    2014-01-01

    Improving bio-security practices among 4-H members who raise and show project animals is important. Bio-security measures can reduce the risk of disease spread and mitigate potential health and economic risks of disease outbreaks involving animal and zoonotic pathogens. Survey data provided statistical evidence that the Bio-Security Proficiencies…

  9. 4H-SiC photodiode model for DC SPICE circuit simulation

    NASA Astrophysics Data System (ADS)

    Kociubiński, Andrzej; Duk, Mariusz; Korona, Mateusz; Muzyka, Krzysztof

    2015-09-01

    Technology, characterization and in particularly modeling of 4H-SiC photodiode have been presented in this paper. Modeling and simulation has been performed using PSPICE environment. Comparison of simulation with real results for electrical characteristic (I-V) of circular SiC photodiodes has been also presented.

  10. Associated Factors in Recruitment and Retention of 4-H Members in West Virginia.

    ERIC Educational Resources Information Center

    Wingenbach, Gary J.; Meighan, Terence; Lawrence, Layle D.; Gartin, Stacy A.; Woloshuk, Jean M.

    1999-01-01

    Extension agents and 4-H Club leaders (n=115) rated the following as effective recruitment techniques: an active club, word of mouth, interesting programs, and members' active role. Successful retention techniques included effective leaders; praise, motivation, and encouragement; and fun meetings, programs, and activities. (SK)

  11. An Evaluation of the 4-H "Health Rocks" Program: Implications for Program Improvement

    ERIC Educational Resources Information Center

    Self, Carlton; Morgan, A. Christian; Fuhrman, Nicholas E.; Navarro, Maria

    2013-01-01

    The National 4-H Council developed the Health Rocks substance abuse educational program to prevent youth from engaging in risky behaviors. The program was presented in 2010 to more than 8,000 middle school youth in Georgia. A post-then-pre evaluation was conducted with youth who completed 10 hours of instruction to determine if changes in youth…

  12. South Carolina's Model for Initiating Hispanic 4-H Clubs

    ERIC Educational Resources Information Center

    Lippert, Robert; Rembert, Kellye

    2012-01-01

    Over the past 5 years, through the initiative of several county Extension agents, South Carolina 4-H has established a successful model for bringing Hispanic youth into our program. We have found the most effective method is to initiate contact and establish partnerships with the principals and ESOL instructors in the local schools. Through this…

  13. The Big E (Energy). 4-H Leader's Guide [for Unit 1].

    ERIC Educational Resources Information Center

    Caldwell, William; And Others

    This guide is designed for leaders of the Nebraska 4-H Energy Project. The goals of the project are to: (1) help young people understand energy problems related to life styles; (2) use energy resources carefully; (3) guide members in choosing their own energy alternatives; and (4) enjoy together the challenges and creativity of finding energy…

  14. A Partnership Model for Training Episodic Environmental Stewardship 4-H Volunteers

    ERIC Educational Resources Information Center

    Young, Jane Chin; Alexander, Janice; Smith, Martin H.

    2013-01-01

    The Marin Environmental Stewardship pilot project demonstrates the potential for a partnership model that brings together external and internal collaborators to recruit and train episodic 4-H volunteers to meet environmental education needs within a community. The clientele served by the volunteers trained through the project was at-risk, urban…

  15. Thickness effects on a cracked aluminum plate with composite patch repair

    NASA Astrophysics Data System (ADS)

    Schubbe, Joel Jon

    Post-repair fatigue crack growth was investigated in 3.175, 4.826, and 6.35 mm thick aluminum panels (508 mm long, 153 mm wide), asymmetrically repaired with boron/epoxy composite patches bonded to the plates with FM73 sheet adhesive. Patches were uniaxial with patch to panel stiffness ratios ranging from 0.46 to 1.3. Experimental fatigue tests were carried out at 120 MPa, R = 0.1, and 10 Hz (sinusoidal) to measure patched and unpatched face crack lengths, center crack opening displacements, and selected strains. Crack growth data was acquired using optical, eddy current, and post-test analysis methods. Crack growth rates were calculated using the incremental polynomial method. Test results showed increased plate thickness caused increased fatigue crack growth rates in both unrepaired and repaired panels. Thermally-induced bending due to patch bonding affects crack growth rates. Increased stiffness ratios increased life-spans and reduced crack growth anomalies such as retardation. Disbond growth is more dependent on crack size than on patch configuration and tends to accelerate when the crack grows beyond a critical length or where the patch changes thickness. A three-layer Mindlin plate finite element model was used as a two-dimensional analytical technique to predict patched and unpatched face reaction loads and displacements. This method uses a third plate layer to model the adhesive layer as a continuum. Constraint equations are used to enforce compatibility conditions along the plate-adhesive and adhesive patch interfaces. The calculated loads and displacements, in conjunction with the modified crack closure method, were used to compute stress intensity factors for the crack tips. Crack growth rates were calculated using experimentally determined material constants and the fatigue crack growth relationship (Paris Law) of the unpatched plate. Comparisons of the experimental to analytical curvatures of repaired panels showed excellent agreement for crack lengths

  16. Using multiple youth programming delivery modes to drive the development of social capital in 4-H participants.

    PubMed

    Kinsey, Sharon

    2013-06-01

    This article focuses on how 4-H youth participants are building social capital, or connections among individuals and community members, through their 4-H experiences. These experiences can be seen through the lens of such 4-H delivery modes as the traditional 4-H club, after-school programs, and school enrichment programs. In addition, other experiences such as leadership camps and conferences or activities in the local community afford youth the opportunity to build the relationships, trust, and respect reflective of social capital. Examples are derived from 4-H program participants-urban, suburban and rural youth-in Camden County, New Jersey. PMID:23878086

  17. ZC4H2 Mutations Are Associated with Arthrogryposis Multiplex Congenita and Intellectual Disability through Impairment of Central and Peripheral Synaptic Plasticity

    PubMed Central

    Hirata, Hiromi; Nanda, Indrajit; van Riesen, Anne; McMichael, Gai; Hu, Hao; Hambrock, Melanie; Papon, Marie-Amélie; Fischer, Ute; Marouillat, Sylviane; Ding, Can; Alirol, Servane; Bienek, Melanie; Preisler-Adams, Sabine; Grimme, Astrid; Seelow, Dominik; Webster, Richard; Haan, Eric; MacLennan, Alastair; Stenzel, Werner; Yap, Tzu Ying; Gardner, Alison; Nguyen, Lam Son; Shaw, Marie; Lebrun, Nicolas; Haas, Stefan A.; Kress, Wolfram; Haaf, Thomas; Schellenberger, Elke; Chelly, Jamel; Viot, Géraldine; Shaffer, Lisa G.; Rosenfeld, Jill A.; Kramer, Nancy; Falk, Rena; El-Khechen, Dima; Escobar, Luis F.; Hennekam, Raoul; Wieacker, Peter; Hübner, Christoph; Ropers, Hans-Hilger; Gecz, Jozef; Schuelke, Markus; Laumonnier, Frédéric; Kalscheuer, Vera M.

    2013-01-01

    Arthrogryposis multiplex congenita (AMC) is caused by heterogeneous pathologies leading to multiple antenatal joint contractures through fetal akinesia. Understanding the pathophysiology of this disorder is important for clinical care of the affected individuals and genetic counseling of the families. We thus aimed to establish the genetic basis of an AMC subtype that is associated with multiple dysmorphic features and intellectual disability (ID). We used haplotype analysis, next-generation sequencing, array comparative genomic hybridization, and chromosome breakpoint mapping to identify the pathogenic mutations in families and simplex cases. Suspected disease variants were verified by cosegregation analysis. We identified disease-causing mutations in the zinc-finger gene ZC4H2 in four families affected by X-linked AMC plus ID and one family affected by cerebral palsy. Several heterozygous females were also affected, but to a lesser degree. Furthermore, we found two ZC4H2 deletions and one rearrangement in two female and one male unrelated simplex cases, respectively. In mouse primary hippocampal neurons, transiently produced ZC4H2 localized to the postsynaptic compartment of excitatory synapses, and the altered protein influenced dendritic spine density. In zebrafish, antisense-morpholino-mediated zc4h2 knockdown caused abnormal swimming and impaired α-motoneuron development. All missense mutations identified herein failed to rescue the swimming defect of zebrafish morphants. We conclude that ZC4H2 point mutations, rearrangements, and small deletions cause a clinically variable broad-spectrum neurodevelopmental disorder of the central and peripheral nervous systems in both familial and simplex cases of both sexes. Our results highlight the importance of ZC4H2 for genetic testing of individuals presenting with ID plus muscle weakness and minor or major forms of AMC. PMID:23623388

  18. ZC4H2 mutations are associated with arthrogryposis multiplex congenita and intellectual disability through impairment of central and peripheral synaptic plasticity.

    PubMed

    Hirata, Hiromi; Nanda, Indrajit; van Riesen, Anne; McMichael, Gai; Hu, Hao; Hambrock, Melanie; Papon, Marie-Amélie; Fischer, Ute; Marouillat, Sylviane; Ding, Can; Alirol, Servane; Bienek, Melanie; Preisler-Adams, Sabine; Grimme, Astrid; Seelow, Dominik; Webster, Richard; Haan, Eric; MacLennan, Alastair; Stenzel, Werner; Yap, Tzu Ying; Gardner, Alison; Nguyen, Lam Son; Shaw, Marie; Lebrun, Nicolas; Haas, Stefan A; Kress, Wolfram; Haaf, Thomas; Schellenberger, Elke; Chelly, Jamel; Viot, Géraldine; Shaffer, Lisa G; Rosenfeld, Jill A; Kramer, Nancy; Falk, Rena; El-Khechen, Dima; Escobar, Luis F; Hennekam, Raoul; Wieacker, Peter; Hübner, Christoph; Ropers, Hans-Hilger; Gecz, Jozef; Schuelke, Markus; Laumonnier, Frédéric; Kalscheuer, Vera M

    2013-05-01

    Arthrogryposis multiplex congenita (AMC) is caused by heterogeneous pathologies leading to multiple antenatal joint contractures through fetal akinesia. Understanding the pathophysiology of this disorder is important for clinical care of the affected individuals and genetic counseling of the families. We thus aimed to establish the genetic basis of an AMC subtype that is associated with multiple dysmorphic features and intellectual disability (ID). We used haplotype analysis, next-generation sequencing, array comparative genomic hybridization, and chromosome breakpoint mapping to identify the pathogenic mutations in families and simplex cases. Suspected disease variants were verified by cosegregation analysis. We identified disease-causing mutations in the zinc-finger gene ZC4H2 in four families affected by X-linked AMC plus ID and one family affected by cerebral palsy. Several heterozygous females were also affected, but to a lesser degree. Furthermore, we found two ZC4H2 deletions and one rearrangement in two female and one male unrelated simplex cases, respectively. In mouse primary hippocampal neurons, transiently produced ZC4H2 localized to the postsynaptic compartment of excitatory synapses, and the altered protein influenced dendritic spine density. In zebrafish, antisense-morpholino-mediated zc4h2 knockdown caused abnormal swimming and impaired α-motoneuron development. All missense mutations identified herein failed to rescue the swimming defect of zebrafish morphants. We conclude that ZC4H2 point mutations, rearrangements, and small deletions cause a clinically variable broad-spectrum neurodevelopmental disorder of the central and peripheral nervous systems in both familial and simplex cases of both sexes. Our results highlight the importance of ZC4H2 for genetic testing of individuals presenting with ID plus muscle weakness and minor or major forms of AMC. PMID:23623388

  19. Patch burning: implications on water erosion and soil properties.

    PubMed

    Ozaslan Parlak, Altingul; Parlak, Mehmet; Blanco-Canqui, Humberto; Schacht, Walter H; Guretzky, John A; Mamo, Martha

    2015-05-01

    Patch burning can be a potential management tool to create grassland heterogeneity and enhance forage productivity and plant biodiversity, but its impacts on soil and environment have not been widely documented. In summer 2013, we studied the effect of time after patch burning (4 mo after burning [recently burned patches], 16 mo after burning [older burned patches], and unburned patches [control]) on vegetative cover, water erosion, and soil properties on a patch-burn experiment established in 2011 on a Yutan silty clay loam near Mead, NE. The recently burned patches had 29 ± 8.0% (mean ± SD) more bare ground, 21 ± 1.4% less canopy cover, and 40 ± 11% less litter cover than older burned and unburned patches. Bare ground and canopy cover did not differ between the older burned and unburned patches, indicating that vegetation recovered. Runoff depth from the older burned and recently burned patches was 2.8 times (19.6 ± 4.1 vs. 7.1 ± 3.0 mm [mean ± SD]) greater than the unburned patches. The recently burned patches had 4.5 times greater sediment loss (293 ± 89 vs. 65 ± 56 g m) and 3.8 times greater sediment-associated organic C loss (9.2 ± 2.0 vs. 2.4 ± 1.9 g m) than the older burned and unburned patches. The recently burned patches had increased daytime soil temperature but no differences in soil compaction and structural properties, dissolved nutrients, soil C, and total N concentration relative to older burned and unburned patches. Overall, recently burned patches can have reduced canopy and litter cover and increased water erosion, but soil properties may not differ from older burn or unburned patches under the conditions of this study. PMID:26024270

  20. High efficiency 4H-SiC betavoltaic power sources using tritium radioisotopes

    NASA Astrophysics Data System (ADS)

    Thomas, Christopher; Portnoff, Samuel; Spencer, M. G.

    2016-01-01

    Realization of an 18.6% efficient 4H-silicon carbide (4H-SiC) large area betavoltaic power source using the radioisotope tritium is reported. A 200 nm 4H-SiC P+N junction is used to collect high-energy electrons. The electron source is a titanium tritide (TiH3x) foil, or an integrated titanium tritide region formed by the diffusion of tritium into titanium. The specific activity of the source is directly measured. Dark current measured under short circuit conditions was less than 6.1 pA/cm2. Samples measured with an external tritium foil produced an open circuit voltage of 2.09 V, short circuit current of 75.47 nA/cm2, fill factor of 0.86, and power efficiency of 18.6%. Samples measured with an integrated source produced power efficiencies of 12%. Simulations were done to determine the beta spectrum (modified by self absorption) exiting the source and the electron hole pair generation function in the 4H-SiC. The electron-hole pair generation function in 4H-SiC was modeled as a Gaussian distribution, and a closed form solution of the continuity equation was used to analyze the cell performance. The effective surface recombination velocity in our samples was found to be 105-106 cm/s. Our analysis demonstrated that the surface recombination dominates the performance of a tritium betavoltaic device but that using a thin P+N junction structure can mitigate some of the negative effects.

  1. Optical beam induced current measurements based on two-photon absorption process in 4H-SiC bipolar diodes

    SciTech Connect

    Hamad, H.; Raynaud, C.; Bevilacqua, P.; Tournier, D.; Planson, D.; Vergne, B.

    2014-02-24

    Using a pulsed green laser with a wavelength of 532 nm, a duration pulse of ∼1 ns, and a mean power varying between 1 and 100 mW, induced photocurrents have been measured in 4H-SiC bipolar diodes. Considering the photon energy (2.33 eV) and the bandgap of 4H-SiC (3.2 eV), the generation of electron-hole pair by the conventional single photon absorption process should be negligible. The intensity of the measured photocurrents depends quadratically on the power beam intensity. This clearly shows that they are generated using two-photon absorption process. As in conventional OBIC (Optical Beam Induced Current), the measurements give an image of the electric field distribution in the structure under test, and the minority carrier lifetime can be extracted from the decrease of the photocurrent at the edge of the structure. The extracted minority carrier lifetime of 210 ns is consistent with results obtained in case of single photon absorption.

  2. Assessment of 4H-SiC epitaxial layers and high resistivity bulk crystals for radiation detectors

    NASA Astrophysics Data System (ADS)

    Mandal, Krishna C.; Muzykov, Peter G.; Chaudhuri, Sandeep K.; Terry, J. R.

    2012-10-01

    We present results of structural, electrical, and defect characterization of 4H-SiC epitaxial layers and bulk crystals and show performance of the radiation detectors fabricated from these materials. The crystal quality was evaluated by x-ray diffraction (XRD) rocking curve measurements, electron beam induced current (EBIC) imaging, and defect delineating etching in conjunction with optical microscopy and scanning electron microscopy (SEM). Studies of the electrically active intrinsic defects and impurities were conducted using thermally stimulated current (TSC) measurements in a wide temperature range of 94 - 750K. The results are correlated with the capability of bulk crystals and epitaxial layers for the detection of α-particles, low to high energy x-rays and gamma rays. High barrier rectifying Schottky diodes have been fabricated and tested. The epitaxial 4H-SiC radiation detectors exhibited low leakage current (< 1 nA) at ~ 200 V operating voltage up to 200 C. The soft x-ray responsivity measurements performed at the National Synchrotron Light Source (NSLS) at Brookhaven National Lab (BNL) showed significantly improved characteristics compared to commercially-available SiC UV photodiode detectors.

  3. Emergent Properties of Patch Shapes Affect Edge Permeability to Animals

    PubMed Central

    Nams, Vilis O.

    2011-01-01

    Animal travel between habitat patches affects populations, communities and ecosystems. There are three levels of organization of edge properties, and each of these can affect animals. At the lowest level are the different habitats on each side of an edge, then there is the edge itself, and finally, at the highest level of organization, is the geometry or structure of the edge. This study used computer simulations to (1) find out whether effects of edge shapes on animal behavior can arise as emergent properties solely due to reactions to edges in general, without the animals reacting to the shapes of the edges, and to (2) generate predictions to allow field and experimental studies to test mechanisms of edge shape response. Individual animals were modeled traveling inside a habitat patch that had different kinds of edge shapes (convex, concave and straight). When animals responded edges of patches, this created an emergent property of responding to the shape of the edge. The response was mostly to absolute width of the shapes, and not the narrowness of them. When animals were attracted to edges, then they tended to collect in convexities and disperse from concavities, and the opposite happened when animals avoided edges. Most of the responses occurred within a distance of 40% of the perceptual range from the tip of the shapes. Predictions were produced for directionality at various locations and combinations of treatments, to be used for testing edge behavior mechanisms. These results suggest that edge shapes tend to either concentrate or disperse animals, simply because the animals are either attracted to or avoid edges, with an effect as great as 3 times the normal density. Thus edge shape could affect processes like pollination, seed predation and dispersal and predator abundance. PMID:21747965

  4. Human pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) after repeated doses taken 4 h apart Human pharmacology of MDMA after repeated doses taken 4 h apart.

    PubMed

    Farré, Magí; Tomillero, Angels; Pérez-Mañá, Clara; Yubero, Samanta; Papaseit, Esther; Roset, Pere-Nolasc; Pujadas, Mitona; Torrens, Marta; Camí, Jordi; de la Torre, Rafael

    2015-10-01

    3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a popular psychostimulant, frequently associated with multiple administrations over a short period of time. Repeated administration of MDMA in experimental settings induces tolerance and metabolic inhibition. The aim is to determine the acute pharmacological effects and pharmacokinetics resulting from two consecutive 100mg doses of MDMA separated by 4h. Ten male volunteers participated in a randomized, double-blind, crossover, placebo-controlled trial. The four conditions were placebo plus placebo, placebo plus MDMA, MDMA plus placebo, and MDMA plus MDMA. Outcome variables included pharmacological effects and pharmacokinetic parameters. After a second dose of MDMA, most effects were similar to those after a single dose, despite a doubling of MDMA concentrations (except for systolic blood pressure and reaction time). After repeated MDMA administration, a 2-fold increase was observed in MDMA plasma concentrations. For a simple dose accumulation MDMA and MDA concentrations were higher (+23.1% Cmax and +17.1% AUC for MDMA and +14.2% Cmax and +10.3% AUC for MDA) and HMMA and HMA concentrations lower (-43.3% Cmax and -39.9% AUC for HMMA and -33.2% Cmax and -35.1% AUC for HMA) than expected, probably related to MDMA metabolic autoinhibition. Although MDMA concentrations doubled after the second dose, most pharmacological effects were similar or slightly higher in comparison to the single administration, except for systolic blood pressure and reaction time which were greater than predicted. The pharmacokinetic-effects relationship suggests that when MDMA is administered at a 4h interval there exists a phenomenon of acute tolerance to its effects. PMID:26073279

  5. Cardiovascular responses to lower body negative pressure before and after 4 h of head-down bed rest and seated control in men and women.

    PubMed

    Edgell, H; Grinberg, A; Gagné, N; Beavers, K R; Hughson, R L

    2012-11-01

    Cardiovascular deconditioning after a 4-h head-down bed rest (HDBR) might be a consequence of the time of day relative to pre-HDBR testing, or simply 4 h of confinement and inactivity rather than the posture change. Ten men and 11 women were studied during lower body negative pressure (LBNP) before and after 4-h HDBR and 4-h seated posture (SEAT) as a control for time of day and physical inactivity effects to test the hypotheses that cardiovascular deconditioning was a consequence of the HDBR posture, and that women would have a greater deconditioning response. Following HDBR, men and women had lower blood volume, higher heart rate with a greater increase during LBNP, a greater decrease of stroke volume during LBNP, lower central venous pressure, smaller inferior vena cava diameter, higher portal vein resistance index with a greater increase during LBNP, but lower forearm vascular resistance, lower norepinephrine, and lower renin. Women had lower vasopressin and men had higher vasopressin after HDBR, and women had lower pelvic impedance and men higher pelvic impedance. Following SEAT, brachial vascular resistance was reduced, thoracic impedance was elevated, the reduction of central venous pressure during LBNP was changed, women had higher angiotensin II whereas men had lower levels, and pelvic impedance increased in women and decreased in men. Cardiovascular deconditioning was greater after 4-h HDBR than after SEAT. Women and men had similar responses for most cardiovascular variables in the present study that tested the responses to LBNP after short-duration HDBR compared with a control condition. PMID:22984250

  6. NORTHWEST OBLIQUE AERIAL VIEW OF FORT DELAWARE AND PEA PATCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NORTHWEST OBLIQUE AERIAL VIEW OF FORT DELAWARE AND PEA PATCH ISLAND. REMAINS OF SEA WALL VISIBLE IN FOREGROUND AND RIGHT OF IMAGE - Fort Delaware, Pea Patch Island, Delaware City, New Castle County, DE

  7. Corridor Length and Patch Colonization by a Butterfly, Junonia coenia

    SciTech Connect

    Haddad, N.

    1999-01-22

    Study hypothesized that corridors increase patch colonization by Junonia coenia regardless of insects initial distance from patch, as the butterfly is known to move between patches preferentially through corridors. Neither corridor nor distance had significant effect on patch colonization, but significant interaction between presence or absence of corridors and distance. One critical factor is interpatch distance which may determine the relative effectiveness of corridors and other landscape configurations.

  8. Ceramic Paste for Patching High-Temperature Insulation

    NASA Technical Reports Server (NTRS)

    Adam, Steven J.; Tompkins, James V.; Toombs, Gordon R.; Hogensen, Pete; Soden, Douglas G.

    2007-01-01

    A ceramic paste that can be applied relatively easily, either by itself or in combination with one or more layer(s) of high-temperature ceramic fabrics, such as silicon carbide or zirconia, has been invented as a means of patching cracks or holes in the reinforced carbon-carbon forward surfaces of a space shuttle in orbit before returning to Earth. The paste or the paste/fabric combination could also be used to repair rocket-motor combustion chambers, and could be used on Earth to patch similar high-temperature structures. The specified chemical composition of the paste admits of a number of variations, and the exact proportions of its constituents are proprietary. In general, the paste consists of (1) silicon carbide, possibly with addition of (2) hafnium carbide, zirconium carbide, zirconium boride, silicon tetraboride, silicon hexaboride, or other metal carbides or oxides blended with (3) a silazane-based polymer. Because the paste is viscous and sticky at normal terrestrial and outer-space ambient temperatures, high-temperature ceramic fabrics such as silicon carbide or zirconia fabric impregnated with the paste (or the paste alone) sticks to the damaged surface to which it is applied. Once the patch has been applied, it is smoothed to minimize edge steps as required [forward-facing edge steps must be < or equal to 0.030 in. (< or equal to 0.76 mm) in the original intended space-shuttle application]. The patch is then heated to a curing temperature thereby converting it from a flexible material to a hard, tough material. The curing temperature is 375 to 450 F (approx.190 to 230 C). In torch tests and arc-jet tests, the cured paste was found to be capable of withstanding a temperature of 3,500 F (approx. 1,900 C) for 15 minutes. As such, the material appears to satisfy the requirement, in the original space-shuttle application, to withstand re-entry temperatures of approx.3,000 F (approx. 1,600 C).

  9. On the evolution of patch-type dependent immigration.

    PubMed

    Gyllenberg, Mats; Kisdi, Éva; Weigang, Helene C

    2016-04-21

    Empirical studies of dispersal indicate that decisions to immigrate are patch-type dependent; yet theoretical models usually ignore this fact. Here, we investigate the evolution of patch-type dependent immigration of a population inhabiting and dispersing in a heterogeneous landscape, which is structured by patches of low and high reward. We model the decision to immigrate in detail from a mechanistic underpinning. With the methods of adaptive dynamics, we derive both analytical and numerical results for the evolution of immigration when life-history traits are patch-type dependent. The model exhibits evolutionary branching in a wide parameter range and the subsequent coevolution can lead to a stable coexistence of a generalist, settling in patches of any type, and a specialist that only immigrates into patches of high reward. We find that individuals always settle in the patches of high reward, in which survival until maturation, relative fecundity and emigration probability are high. We investigate how the probability to immigrate into patches of low reward changes with model parameters. For example, we show that immigration into patches of low reward increases when the emigration probability in these patches increases. Further, immigration into patches of low reward decreases when the patches of high reward become less safe during the dispersal season. PMID:26860659

  10. Synthesis and crystal and molecular structure of a tetranuclear cluster based on the rhenium(III)-bisorganohydrazino core: [Re(HNNC(4)H(3)N(2))(NNC(4)H(3)N(2))(OCH(3))(2)](4).

    PubMed

    Femia, Frank J; Chen, Xiaoyuan; Maresca, Kevin P; Babich, John W; Zubieta, Jon

    2000-09-01

    Reaction of NH(4)ReO(4) with excess 2-hydrazinopyrimidine in methanol yields [Re(eta(1)-NNC(4)H(3)N(2)H)(eta(2)-HNNC(4)H(3)N(2))Cl(3)] (1). Attempts to recrystallize 1 by slow diffusion of methanol into DMF after 8 months produced black crystals of [Re(HNNC(4)H(3)N(2))(NNC(4)H(3)N(2))(OCH(3))(2)](4) (2). The structure of 2 consists of isolated tetranuclear clusters, constructed from {Re(eta(2)-HNNC(4)H(3)N(2))(eta(1)-NNC(4)H(3)N(2))(OCH(3))(2)} units linked through the beta-nitrogen of the chelating organodiazene ligand of adjacent units into a box-like aggregate. PMID:20613968

  11. Atypical scabies presenting as annular patches.

    PubMed

    Hossain, Delwar

    2014-01-01

    Scabies is a common parasitic disease that can be recognized by the development of itchy lesions and a predilection for certain places on the body. It may infrequently present with patchy lesions. We report a patient with well-defined annular patches. Histopathology showed an egg of the scabies mite in the epidermis. Treatment with permethrin cream resulted in complete resolution of her disease. PMID:22967356

  12. Design of an innovative magnetostrictive patch actuator

    NASA Astrophysics Data System (ADS)

    Cinquemani, S.; Giberti, H.

    2015-04-01

    Magnetostrictive actuators can be profitably used to reduce vibration in structures. However, this technology has been exploited only to develop inertial actuators, while patches actuators have not been ever used in practice. Patches actuators consist on a layer of magnetostrictive material, which has to be stuck to the surface of the vibrating structure, and on a coil surrounding the layer itself. However, the presence of the winding severely limits the use of such devices. As a matter of fact, the scientific literature reports only theoretical uses of such actuators, but, in practice it does not seem they were ever used. This paper presents an innovative solution to improve the structure of the actuator patches, allowing their use in several practical applications. The principle of operation of these devices is rather simple. The actuator patch is able to generate a local deformation of the surface of the vibrating structure so as to introduce an equivalent damping that dissipates the kinetic energy associated to the vibration. This deformation is related to the behavior of the magnetostrictive material immersed in a variable magnetic field generated by the a variable current flowing in the winding. Contrary to what suggested in the theoretical literature, the designed device has the advantage of generating the variable magnetic field no longer in close proximity of the material, but in a different area, thus allowing a better coupling. The magnetic field is then conveyed through a suitable ferromagnetic structure to the magnetostrictive material. The device has been designed and simulated through FEA. Results confirm that the new configuration can easily overcome all the limits of traditional devices.

  13. Solubility and diffusion of chromium in 4H-SiC

    NASA Astrophysics Data System (ADS)

    Danno, Katsunori; Saito, Makoto; Seki, Akinori; Sato, Kazuaki; Bessho, Takeshi; Kimoto, Tsunenobu

    2016-06-01

    The solubility and diffusivity of Cr atoms in 4H-SiC epilayers are investigated. The formation energy of 4H-SiC containing Cr has been calculated by first-principles calculation. Si sites have been found to be more stable than C sites or interstitial sites for Cr atoms owing to the lower formation energy. The solubility estimated from the formation energy coincides with the saturated Cr concentration in SiC crystals grown by solution growth. The diffusivity of implanted Cr atoms (located at interstitial sites) was not affected by the charge states of Cr atoms and/or vacancies such as carbon vacancies and silicon vacancies, implying the interstitial diffusion of Cr atoms.

  14. Donor-acceptor-pair emission in fluorescent 4H-SiC grown by PVT method

    SciTech Connect

    Liu, Xi Zhuo, Shi-Yi; Gao, Pan; Huang, Wei; Yan, Cheng-Feng; Shi, Er-Wei

    2015-04-15

    Fluorescent SiC, which contains donor and acceptor impurities with optimum concentrations, can work as a phosphor for visible light emission by donor-acceptor-pair (DAP) recombination. In this work, 3 inch N-B-Al co-doped fluorescent 4H-SiC crystals are prepared by PVT method. The p-type fluorescent 4H-SiC with low aluminum doping concentration can show intensive yellow-green fluorescence at room temperature. N-B DAP peak wavelength shifts from 578nm to 525nm and weak N-Al DAP emission occurred 403/420 nm quenches, when the temperature increases from 4K to 298K. The aluminum doping induces higher defect concentration in the fluorescent crystal and decreases optical transmissivity of the crystal in the visible light range. It triggers more non-radiative recombination and light absorption losses in the crystal.

  15. A novel 4H-SiC MESFET with clival gate

    NASA Astrophysics Data System (ADS)

    Jia, Hujun; Xing, Ding; Zhang, Hang; Pei, Xiaoyan; Sun, Zhelin; Yuan, Yingchun

    2015-07-01

    In this paper, a novel 4H-SiC metal semiconductor field effect transistor (MESFET) with a clival gate structure (CG-MESFET) is proposed. The drain current (ID) and the breakdown voltage (VB) are simulated and compared to the traditional double-recessed gate 4H-SiC MESFET (DR-MESFET). The results indicate that the drain current (ID) of the CG-MESFET transforms with the change of end point of clival gate (EPCG), and it reaches to a maximum value about 545 mA when EPCG is at 1/2 of whole gate, thus, the drain current (ID) has a much greater increase than that of the DR-MESFET. The CG-MESFET has the advantages of high breakdown voltage (VB) that is increased by 15% and superior DC performances over the DR-MESFET.

  16. Structure determination of an amorphous compound AlB4H11.

    SciTech Connect

    Chen, Xuenian; Zhang, Yongsheng; Wang, Yongli; Zhou, Wei; Knight, Douglas A; Yisgedu, Teshome; Huang, Zhenguo; Lingam, Hima; Billet, Beau; Udovic, Terrence J; Brown, Gilbert M; Shore, Sheldon; Wolverton, Christopher; Zhao, J.-C.

    2012-01-01

    The structure of the amorphous aluminoborane compound AlB4H11 was identified through a collaborative study closely coupling a first-principles density functional based approach with experimental measurements using IR, NMR, and neutron vibrational spectroscopy (NVS). The AlB4H11 structure was found to contain distinct [BH4] and [B3H7] units without any [AlH4] units. It forms a [B3H7] Al(BH4) polymer chain with the [BH4] units twisted relative to each other perpendicular to the chain direction and bonded to Al, and a chain backbone consists of [B3H7] and Al where the [B3H7] unit exhibits a triangular boron configuration. The computed lowest energy structure shows good agreement with results of IR, NVS and NMR spectra; this agreement demonstrates the extended applicability of the structure prediction approach to the prediction of even amorphous compounds.

  17. Thermodynamic calculations in the system CH4-H2O and methane hydrate phase equilibria

    USGS Publications Warehouse

    Circone, S.; Kirby, S.H.; Stern, L.A.

    2006-01-01

    Using the Gibbs function of reaction, equilibrium pressure, temperature conditions for the formation of methane clathrate hydrate have been calculated from the thermodynamic properties of phases in the system CH4-H 2O. The thermodynamic model accurately reproduces the published phase-equilibria data to within ??2 K of the observed equilibrium boundaries in the range 0.08-117 MPa and 190-307 K. The model also provides an estimate of the third-law entropy of methane hydrate at 273.15 K, 0.1 MPa of 56.2 J mol-1 K-1 for 1/n CH4??H 2O, where n is the hydrate number. Agreement between the calculated and published phase-equilibria data is optimized when the hydrate composition is fixed and independent of the pressure and temperature for the conditions modeled. ?? 2006 American Chemical Society.

  18. Donor-acceptor-pair emission in fluorescent 4H-SiC grown by PVT method

    NASA Astrophysics Data System (ADS)

    Liu, Xi; Zhuo, Shi-Yi; Gao, Pan; Huang, Wei; Yan, Cheng-Feng; Shi, Er-Wei

    2015-04-01

    Fluorescent SiC, which contains donor and acceptor impurities with optimum concentrations, can work as a phosphor for visible light emission by donor-acceptor-pair (DAP) recombination. In this work, 3 inch N-B-Al co-doped fluorescent 4H-SiC crystals are prepared by PVT method. The p-type fluorescent 4H-SiC with low aluminum doping concentration can show intensive yellow-green fluorescence at room temperature. N-B DAP peak wavelength shifts from 578nm to 525nm and weak N-Al DAP emission occurred 403/420 nm quenches, when the temperature increases from 4K to 298K. The aluminum doping induces higher defect concentration in the fluorescent crystal and decreases optical transmissivity of the crystal in the visible light range. It triggers more non-radiative recombination and light absorption losses in the crystal.

  19. Monte Carlo Simulation of Electron Transport in 4H- and 6H-SiC

    SciTech Connect

    Sun, C. C.; You, A. H.; Wong, E. K.

    2010-07-07

    The Monte Carlo (MC) simulation of electron transport properties at high electric field region in 4H- and 6H-SiC are presented. This MC model includes two non-parabolic conduction bands. Based on the material parameters, the electron scattering rates included polar optical phonon scattering, optical phonon scattering and acoustic phonon scattering are evaluated. The electron drift velocity, energy and free flight time are simulated as a function of applied electric field at an impurity concentration of 1x10{sup 18} cm{sup 3} in room temperature. The simulated drift velocity with electric field dependencies is in a good agreement with experimental results found in literature. The saturation velocities for both polytypes are close, but the scattering rates are much more pronounced for 6H-SiC. Our simulation model clearly shows complete electron transport properties in 4H- and 6H-SiC.

  20. The C4H radical and the diffuse interstellar bands. An ab initio study

    NASA Technical Reports Server (NTRS)

    Kolbuszewski, Marcin

    1994-01-01

    An ab initio study of the low-lying electronic states of C4H has been presented where the species studied has a chi(2)sigma(+) ground state and two low lying pi states. Based on the vertical and adiabatic excitation energies between those states it is suggested that the 4428 A diffuse interstellar band is not carried by C4H. The application of the particle in a box model shows strong coincidences between the strong DIB's and predicted wavelengths of pi-pi transitions in C(2n)H series. Based on those coincidences, it is suggested the C(2n)H species as good candidates for carriers of diffuse interstellar bands.

  1. Strain energy analysis of screw dislocations in 4H-SiC by molecular dynamics

    NASA Astrophysics Data System (ADS)

    Kawamura, Takahiro; Mizutani, Mitsutoshi; Suzuki, Yasuyuki; Kangawa, Yoshihiro; Kakimoto, Koichi

    2016-03-01

    We simulated screw dislocations with the Burgers vector parallel to the [0001] direction in 4H-SiC by a classical molecular dynamics method. A stable structure of an extended dislocation generated by the dissociation of a screw dislocation was identified by calculating the strain energy caused by dislocation cores and stacking faults. As a result, we conclude that the most expected structure of the extended dislocation is made of partial dislocations with the Burgers vector b = 1/2c + 1/2c (c is equal to the thickness of one period in the c-axis direction of 4H-SiC) and the stacking fault that is parallel to the a-plane, and that the distance between the dislocation cores is less than about 44 Å.

  2. Free carrier absorption and lifetime mapping in 4H SiC epilayers

    SciTech Connect

    Galeckas, A.; Grivickas, V.; Linnros, J.; Bleichner, H.

    1997-04-01

    Results of carrier lifetime studies in low-doped epitaxial 4H SiC layers are reported. The free carrier absorption (FCA) technique was applied to extract carrier lifetime parameters and their spatial distribution in a wide photoexcitation range. The FCA magnitude is shown to scale linearly with the photoinjected carrier concentration, while the absorption cross section increases according to a {lambda}{sup 4.4} law for near infrared wavelengths. High spatial resolution carrier lifetime mapping of large 4H SiC areas revealed features related to structural imperfections of epilayers. Finally, a density dependent fast lifetime component was observed at high injection levels and attributed to band-to-band Auger recombination. {copyright} {ital 1997 American Institute of Physics.}

  3. Detection of minority carrier traps in p-type 4H-SiC

    SciTech Connect

    Alfieri, G.; Kimoto, T.

    2014-03-03

    Contrarily to the case of n-type 4H-SiC, very little is known about the presence of minority carrier traps in p-type epilayers. In this study, we performed the electrical characterization of as-grown, electron irradiated, and thermally oxidized p-type 4H-SiC, by using minority carrier transient spectroscopy. Four minority carrier traps are reported in 1.6–2.3 eV energy range above the valence band edge (E{sub V}). Particular emphasis is given to the mid-gap minority carrier trap (EH{sub 6∕7}) and to its correlation to an energetically close mid-gap majority carrier trap (HK4)

  4. Fabrication and characteristics of a 4H-SiC junction barrier Schottky diode

    NASA Astrophysics Data System (ADS)

    Fengping, Chen; Yuming, Zhang; Hongliang, Lü; Yimen, Zhang; Hui, Guo; Xin, Guo

    2011-06-01

    4H-SiC junction barrier Schottky (JBS) diodes with four kinds of design have been fabricated and characterized using two different processes in which one is fabricated by making the P-type ohmic contact of the anode independently, and the other is processed by depositing a Schottky metal multi-layer on the whole anode. The reverse performances are compared to find the influences of these factors. The results show that JBS diodes with field guard rings have a lower reverse current density and a higher breakdown voltage, and with independent P-type ohmic contact manufacturing, the reverse performance of 4H-SiC JBS diodes can be improved effectively. Furthermore, the P-type ohmic contact is studied in this work.

  5. Hall scattering factors in p-type 4H-SiC with various doping concentrations

    NASA Astrophysics Data System (ADS)

    Asada, Satoshi; Okuda, Takafumi; Kimoto, Tsunenobu; Suda, Jun

    2016-04-01

    The Hall scattering factor (γH) in p-type 4H-SiC with various aluminum doping concentrations of 5.8 × 1014-7.1 × 1018 cm-3 was investigated from 300 to 900 K. γH was determined by comparing the Hall coefficient with the theoretical carrier concentration derived from acceptor and donor concentrations obtained from secondary ion mass spectrometry and capacitance-voltage measurements. γH decreased with increasing temperature or doping concentration; γH = 1-0.4 for the doping concentration of 5.8 × 1014 cm-3 and γH = 0.5-0.2 for the doping concentration of 7.1 × 1018 cm-3. The dependence might be caused by the anisotropic and nonparabolic valence band structure of 4H-SiC.

  6. Crystal structure induced residue formation on 4H-SiC by reactive ion etching

    NASA Astrophysics Data System (ADS)

    Liu, Yi-hong; Sun, Yu-jun; Zhao, Gao-jie; Liao, Li-ming; Wang, Tao; Chen, Zhi-zhan

    2016-06-01

    The (000 1 ¯) C face of 4H-SiC wafer was etched by reactive ion etching in SF6/O2 plasma. The effect of etching parameters, such as work pressure, SF6:O2 ratio and etching time, on the residue formation were systematically investigated. The residue morphologies were observed by scanning electron microscopy and atomic force microscopy, respectively. The residues have spike shape and their facets are defined as { 1 1 ¯ 0 2 ¯ } crystal planes. They are formed at beginning of the etching and no new spikes are generated as prolonging etching time. Both work pressure and SF6:O2 ratio play significant role in the spike formation. The residues can be eliminated completely by increasing the SF6:O2 ratio and work pressure. On the basis of experimental results and of 4H-SiC crystal structure, the spike formation model is proposed.

  7. Nitrogen passivation of deposited oxides on n 4H-SiC

    NASA Astrophysics Data System (ADS)

    Chung, G. Y.; Williams, J. R.; Isaacs-Smith, T.; Ren, F.; McDonald, K.; Feldman, L. C.

    2002-11-01

    Results for measurements of interface state density and breakdown field strength are reported for deposited oxides on n 4H-SiC following passivation with nitric oxide. Low-temperature oxides deposited by plasma-enhanced chemical vapor deposition and high-temperature oxides deposited at 950 °C were investigated. Nitrogen passivation of deposited oxides on n 4H-SiC is found to produce interface state densities of 1-2×1012cm-2 eV-1 at Ec-E=0.1 eV, regardless of variations in oxide deposition procedures that affect the residual interfacial carbon concentration. Breakdown field strengths were higher for passivated high-temperature oxides compared to passivated low-temperature oxides at room temperature and 290 °C. We suggest that additional oxide growth during the NO passivation is the reason for the observed interface state densities.

  8. A 4H Silicon Carbide Gate Buffer for Integrated Power Systems

    SciTech Connect

    Ericson, N; Frank, S; Britton, C; Marlino, L; Ryu, SH; Grider, D; Mantooth, A; Francis, M; Lamichhane, R; Mudholkar, M; Shepherd, P; Glover, M; Valle-Mayorga, J; McNutt, T; Barkley, A; Whitaker, B; Cole, Z; Passmore, B; Lostetter, A

    2014-02-01

    A gate buffer fabricated in a 2-mu m 4H silicon carbide (SiC) process is presented. The circuit is composed of an input buffer stage with a push-pull output stage, and is fabricated using enhancement mode N-channel FETs in a process optimized for SiC power switching devices. Simulation and measurement results of the fabricated gate buffer are presented and compared for operation at various voltage supply levels, with a capacitive load of 2 nF. Details of the design including layout specifics, simulation results, and directions for future improvement of this buffer are presented. In addition, plans for its incorporation into an isolated high-side/low-side gate-driver architecture, fully integrated with power switching devices in a SiC process, are briefly discussed. This letter represents the first reported MOSFET-based gate buffer fabricated in 4H SiC.

  9. Nanowired three-dimensional cardiac patches

    NASA Astrophysics Data System (ADS)

    Dvir, Tal; Timko, Brian P.; Brigham, Mark D.; Naik, Shreesh R.; Karajanagi, Sandeep S.; Levy, Oren; Jin, Hongwei; Parker, Kevin K.; Langer, Robert; Kohane, Daniel S.

    2011-11-01

    Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds. These biomaterials, which are usually made of either biological polymers such as alginate or synthetic polymers such as poly(lactic acid) (PLA), help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches.

  10. Nanowired three-dimensional cardiac patches.

    PubMed

    Dvir, Tal; Timko, Brian P; Brigham, Mark D; Naik, Shreesh R; Karajanagi, Sandeep S; Levy, Oren; Jin, Hongwei; Parker, Kevin K; Langer, Robert; Kohane, Daniel S

    2011-11-01

    Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds. These biomaterials, which are usually made of either biological polymers such as alginate or synthetic polymers such as poly(lactic acid) (PLA), help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches. PMID:21946708

  11. Enantioselective synthesis of 4H-pyranonaphthoquinones via sequential squaramide and silver catalysis.

    PubMed

    Kaya, Uğur; Chauhan, Pankaj; Hack, Daniel; Deckers, Kristina; Puttreddy, Rakesh; Rissanen, Kari; Enders, Dieter

    2016-01-28

    An enantioselective one-pot Michael addition/hydroalkoxylation reaction between 2-hydroxy-1,4-naphthoquinones and alkyne-tethered nitroalkenes catalyzed by a cinchona-derived squaramide and a silver(I) salt has been developed. The sequential protocol provides a direct access to 4H-pyranonaphthoquinones in moderate to very good yields and good to excellent enantioselectivities at a very low catalyst loading (0.5 mol%) of the squaramide. PMID:26660230

  12. Electric-field dependence of electron drift velocity in 4H-SiC

    NASA Astrophysics Data System (ADS)

    Ivanov, P. A.; Potapov, A. S.; Samsonova, T. P.; Grekhov, I. V.

    2016-09-01

    Room temperature isothermal forward current-voltage characteristics of mesa-epitaxial 4H-SiC Schottky diodes were measured at high electric fields (beyond 105 V/cm) in the 34-μm thick n-base doped at 1 × 1015 cm-3. The effect of diode self-heating on current was minimized when using single 4-ns pulses. The analytical formula was derived for the dependence of electron drift velocity on electric field along c-axis.

  13. Defect formation in 4H-SiC single crystal grown on the prismatic seeds

    NASA Astrophysics Data System (ADS)

    Fadeev, A. Yu; Lebedev, A. O.; Tairov, Yu M.

    2014-12-01

    The defect structure of 4H silicon carbide single crystals grown by PVT method on three prismatic seeds (10-10), (11-20) and (8.3.-11.0) is considered. The only defects existing in the grown ingots are stacking faults and basal plane dislocations. The type of stacking fault is studied. The dependence of stacking fault morphology on the seed orientation is analyzed.

  14. High Resolution Topography Analysis on Threading Edge Dislocations in 4H-SiC Epilayers

    SciTech Connect

    Kamata, I.; Nagano, M; Tsuchida, H; Chen, Y; Dudley, M

    2009-01-01

    Threading edge dislocations (TEDs) in a 4H-SiC epitaxial layer are investigated using high-resolution synchrotron topography. Six types of TED image are confirmed to correspond to the Burgers vector directions by a comparison of computer simulated images and observed topography images in crystal boundaries. Using a mapping method, a wide spatial distribution of the six types of TED is examined in a quarter section of a 2-inch wafer.

  15. Polarographic study of cadmium 5-hydroxy 2-(hydroxymethyl) 4H-pyran-4-one complex

    NASA Technical Reports Server (NTRS)

    Wilson, Ray F.; Daniels, Robert C.

    1989-01-01

    A polarographic study was performed on the products formed in the interaction of cadmium (II) with a 5-hydroxy 2-(hydroxymethyl) 4H-Pyran-4-one, using varying conditions of pH, supporting electrolytes, and concentrations. Measurements using the differential pulse method show that cadmium (II) exhibits a molar combining ratio of complexing agents to cation ranging from 1 to 1 to 3 to 1 depending on the pH and the supporting electrolyte employed.

  16. Resistance of 4H-SiC Schottky barriers at high forward-current densities

    SciTech Connect

    Ivanov, P. A. Samsonova, T. P.; Il’inskaya, N. D.; Serebrennikova, O. Yu.; Kon’kov, O. I.; Potapov, A. S.

    2015-07-15

    The resistance of Schottky barriers based on 4H-SiC is experimentally determined at high forward-current densities. The measured resistance is found to be significantly higher than the resistance predicted by classical mechanisms of electron transport in Schottky contacts. An assumption concerning the crucial contribution of the tunnel-transparent intermediate oxide layer between the metal and semiconductor to the barrier resistance is proposed and partially justified.

  17. Bis(4H-1,2,4-triazol-3-yl)disulfane

    PubMed Central

    Liu, Dongsheng; Xu, Yaping; Li, Xinfa; Ying, Shaoming; Chen, Wentong

    2008-01-01

    The title compound, C4H4N6S2, was synthesized by the reaction of 3-mercapto-1H-1,2,4-triazole with sodium hydrox­ide in ethanol. The mol­ecule possesses a crystallographically imposed twofold axis. Inter­molecular N—H⋯N hydrogen bonds link the mol­ecules into chains along the c axis. PMID:21200812

  18. Theoretical microwave spectral constants for C3H/+/ and C4H/+/

    NASA Technical Reports Server (NTRS)

    Wilson, S.; Green, S.

    1980-01-01

    A number of linear conjugated carbon chain molecules have been observed in the interstellar gas. It has been suggested that ion molecule chemistry schemes may explain the formation of these compounds. In the present paper, theoretical bond lengths and rotation constants are obtained for C3H(+) and C4H(+). Calculations for C3 are used to assess the accuracy of the former. Recent results for C2H(+) are examined.

  19. A novel conformational B-cell epitope prediction method based on mimotope and patch analysis.

    PubMed

    Sun, Pingping; Qi, Jialiang; Zhao, Yizhu; Huang, Yanxin; Yang, Guifu; Ma, Zhiqiang; Li, Yuxin

    2016-04-01

    A B-cell epitope is a group of residues on the surface of an antigen that stimulates humoral immune responses. Identifying B-cell epitopes is important for effective vaccine design. Predicting epitopes by experimental methods is expensive in terms of time, cost and effort; therefore, computational methods that have a low cost and high speed are widely used to predict B-cell epitopes. Recently, epitope prediction based on random peptide library screening has been viewed as a promising method. Some novel software and web-based servers have been proposed that have succeeded in some test cases. Herein, we propose a novel epitope prediction method based on amino acid pairs and patch analysis. The method first divides antigen surfaces into overlapping patches based on both radius (R) and number (N), then predict epitopes based on Amino Acid Pairs (AAPs) from mimotopes and the surface patch. The proposed method yields a mean sensitivity of 0.53, specificity of 0.77, ACC of 0.75 and F-measure of 0.45 for 39 test cases. Compared with mimotope-based methods, patch-based methods and two other prediction methods, the sensitivity of the new method offers a certain improvement. Our findings demonstrate that this proposed method was successful for patch and AAPs analysis and allowed for conformational B-cell epitope prediction. PMID:26804644

  20. Experimental Fatigue Study of Composite Patch Repaired Steel Plates with Cracks

    NASA Astrophysics Data System (ADS)

    Karatzas, Vasileios A.; Kotsidis, Elias A.; Tsouvalis, Nicholas G.

    2015-10-01

    Cracks are among the most commonly encountered defects in metallic structures operating at sea. Composite patch repairing is a repair method which is gaining popularity as it counters most of the problems faced by conventional renewal repairs. Extensive studies can be found in the literature addressing the efficiency of this novel repair method using techniques which meet higher performance and monitoring standards than these commonly found in naval applications. In this work the efficiency of practices widely used in the ship repair industry for the implementation of composite patch repairing is addressed. To this end, steel plates repaired with composite patches were tested under fatigue loading. The composite patches consisted of carbon fibers in epoxy matrix and were directly laminated to the steel surface using the vacuum infusion method. Two different surface preparation methods, namely grit-blasting and mechanical treatment with the use of a needle gun were studied. In addition, in order to account for the harsh environmental conditions during the operating life of the structure and to study its effect on the repair, two different aging scenarios were considered. Non-destructive evaluation of the patches was performed so as to assess the quality of the repair, and the evolution of debonding during testing.

  1. Laboratory detection of the C3N an C4H free radicals

    NASA Technical Reports Server (NTRS)

    Gottlieb, C. A.; Gottlieb, E. W.; Thaddeus, P.; Kawamura, H.

    1983-01-01

    The millimeter-wave spectra of the linear carbon chain free radicals C3N and C4H, first identified in IRC + 10216 and hitherto observed only in a few astronomical sources, have been detected with a Zeeman-modulated spectrometer in laboratory glow discharges through low pressure flowing mixtures of N2 + HC3N and He + HCCH, respectively. Four successive rotational transitions between 168 and 198 GHz have been measured for C3N, and five rotational transitions between 143 and 200 GHz for C4H; each is a well-resolved spin doublet owing to the unpaired electron present in both species. Precise values for the rotational, centrifugal distortion, and spin doubling constants have been obtained, which, with hyperfine constants derived from observations of the lower rotational transitions in the astronomical source TMC 1, allow all the rotational transitions of C3N and C4H at frequencies less than 300 GHz to be calculated to an absolute accuracy exceeding 1 ppm.

  2. Carbon-antisite vacancy defect in 4H silicon carbide for realizing solid state qubit

    NASA Astrophysics Data System (ADS)

    Gali, Adam; Szász, Krisztián; Ivády, Viktor; Abrikosov, Igor; Bockstedte, Michel; Janzén, Erik

    2015-03-01

    Dopants in solids are promising candidates for implementations of quantum bits for quantum computing. Silicon carbide (SiC) with engineered point defects is considered as very promising material for the next generation devices, with applications ranging from electronics and photonics to quantum computing. Employing density functional theory and many body perturbation theory, we show that the neutral carbon antisite-vacancy pair (CAV) has high spin ground state, and that its spin may be coherently manipulated by optical excitation in n-type 4H SiC. As the positively charged CAV defect in 4H SiC has been recently engineered to act as single photon source, our finding brings a hope that optically addressed quantum bits can be realized by the neutral CAV defects in 4H SiC, and provide an additional target for researchers seeking for solid state single color centers for quantum information processes and metrology. The calculated zero-phonon line of the optically excited state is about 1550 nm (0.8 eV) which perfectly fits to the telecom wavelengths, that makes this qubit candidate very promising for integration of quantum optics devices with existing fiber optics technology. Lendület program of Hungarian Academy of Sciences, the Knut & Alice Wallenberg Foundation, Swedish Research Council, US DoE.

  3. Extended charge accumulation in ruthenium-4H-imidazole-based black absorbers: a theoretical design concept.

    PubMed

    Kupfer, Stephan

    2016-05-11

    A theoretical-guided design concept aiming to achieve highly efficient unidirectional charge transfer and multi-charge separation upon successive photoexcitation for light-harvesting dyes in the scope of supramolecular photocatalysts is presented. Four 4H-imidazole-ruthenium(ii) complexes incorporating a biimidazole-based electron-donating ligand sphere have been designed based on the well-known 4H-imidazole-ruthenium(ii) polypyridyl dyes. The quantum chemical evaluation, performed at the density functional and time-dependent density functional level of theory, revealed extraordinary unidirectional charge transfer bands from the near-infrared to the ultraviolet region of the absorption spectrum upon multi-photoexcitation. Spectro-electrochemical simulations modeling photoexcited intermediates determined the outstanding multi-electron storage capacity for this novel class of black dyes. These remarkable photochemical and photophysical properties are found to be preserved upon site-specific protonation rendering 4H-imidazole-ruthenium(ii) biimidazole dyes ideal for light-harvesting applications in the field of solar energy conversion. PMID:27121270

  4. Identification of the Amorphous AlB4H11 Structure

    NASA Astrophysics Data System (ADS)

    Wang, Yongli; Zhang, Yongsheng; Chen, Xuenian; Zhao, Ji-Cheng; Zhou, Wei; Udovic, Terrence; Wolverton, C.

    2012-02-01

    In recent experimental work, AlB4H11 has been identified as a potential hydrogen storage material with a good desorption temperature and partial reversibility. It is an amorphous, white solid at room temperature and its molecular structure is presently unknown. We combine experimental measurements (NMR, neutron vibrational spectra and IR) and a theoretical structure prediction method to identify the (local) structure of the amorphous AlB4H11 phase. The theoretical structure prediction method is a combination of the Monte-Carlo based prototype electrostatic ground state search (PEGS) method and first-principles calculation (DFT). The PEGS+DFT method has successfully predicted many crystalline solid structures, but has never been applied to the prediction of amorphous solid structures. The PEGS predictions of the AlB4H11 structure are quite successful: we find the calculated phonon density of states (pDOS) of our PEGS+DFT predicted structures is in close agreement with the experimental vibrational measurements. More broadly, our findings indicate that first-principles theoretical design of new amorphous materials for energy storage is now possible, paving a promising way for similar studies in the future.

  5. A remarkable activity of human leukotriene A4 hydrolase (LTA4H) toward unnatural amino acids.

    PubMed

    Byzia, Anna; Haeggström, Jesper Z; Salvesen, Guy S; Drag, Marcin

    2014-05-01

    Leukotriene A4 hydrolase (LTA4H--EC 3.3.2.6) is a bifunctional zinc metalloenzyme, which processes LTA4 through an epoxide hydrolase activity and is also able to trim one amino acid at a time from N-terminal peptidic substrates via its aminopeptidase activity. In this report, we have utilized a library of 130 individual proteinogenic and unnatural amino acid fluorogenic substrates to determine the aminopeptidase specificity of this enzyme. We have found that the best proteinogenic amino acid recognized by LTA4H is arginine. However, we have also observed several unnatural amino acids, which were significantly better in terms of cleavage rate (k cat/K m values). Among them, the benzyl ester of aspartic acid exhibited a k cat/K m value that was more than two orders of magnitude higher (1.75 × 10(5) M(-1) s(-1)) as compared to L-Arg (1.5 × 10(3) M(-1) s(-1)). This information can be used for design of potent inhibitors of this enzyme, but may also suggest yet undiscovered functions or specificities of LTA4H. PMID:24573245

  6. Ab initio study of the O4H(+) novel species: spectroscopic fingerprints to aid its observation.

    PubMed

    Xavier, F George D; Hernández-Lamoneda, Rámon

    2015-06-28

    A detailed ab initio characterization of the structural, energetic and spectroscopic properties of the novel O4H(+) species is presented. The equilibrium structures and relative energies of all multiplet states have been determined systematically by analyzing static and dynamical correlation effects. The two and three body dissociation processes have been studied and indicate the presence of conical intersections in various states including the ground state. Comparison with available thermochemical data is very good, supporting the applied methodology. The reaction, H3(+) + O4→ O4H(+) + H2, was found to be exothermic ΔH = -19.4 kcal mol(-1) and therefore, it is proposed that the product in the singlet state could be formed in the interstellar medium (ISM) via collision processes. To aid in its laboratory or radioastronomy detection in the interstellar medium we determined spectroscopic fingerprints. It is estimated for the most stable geometry of O4H(+) dipole allowed electronic transitions in the visible region at 429 nm and 666 nm, an intense band at 1745 cm(-1) in the infrared and signals at 40.6, 81.2 and 139.2 GHz in the microwave region at 10, 50 and 150 K respectively, relevant for detection in the ISM. PMID:26028209

  7. Characterization of a n+3C/n-4H SiC heterojunction diode

    NASA Astrophysics Data System (ADS)

    Minamisawa, R. A.; Mihaila, A.; Farkas, I.; Teodorescu, V. S.; Afanas'ev, V. V.; Hsu, C.-W.; Janzén, E.; Rahimo, M.

    2016-04-01

    We report on the fabrication of n + 3C/n-4H SiC heterojunction diodes (HJDs) potentially promising the ultimate thermal stability of the junction. The diodes were systematically analyzed by TEM, X-ray diffraction, AFM, and secondary ion mass spectroscopy, indicating the formation of epitaxial 3C-SiC crystal on top of 4H-SiC substrate with continuous interface, low surface roughness, and up to ˜7 × 1017 cm-3 dopant impurity concentration. The conduction band off-set is about 1 V as extracted from CV measurements, while the valence bands of both SiC polytypes are aligned. The HJDs feature opening voltage of 1.65 V, consistent with the barrier height of about 1.5 eV extracted from CV measurement. We finally compare the electrical results of the n + 3C/n-4H SiC heterojunction diodes with those featuring Si and Ge doped anodes in order to evaluate current challenges involved in the fabrication of such devices.

  8. Demonstration of the First 4H-SiC EUV Detector with Large Detection Area

    NASA Technical Reports Server (NTRS)

    Xin, Xiaobin; Yan, Feng; Koeth, Timothy W.; Hu, Jun; Zhao, Jian H.

    2005-01-01

    Ultraviolet (UV) and Extreme Ultraviolet (EUV) detectors are very attractive in astronomy, photolithography and biochemical applications. For EUV applications, most of the semiconductor detectors based on PN or PIN structures suffer from the very short penetration depth. Most of the carries are absorbed at the surface and recombined there due to the high surface recombination before reach the depletion region, resulting very low quantum efficiency. On the other hand, for Schottky structures, the active region starts from the surface and carriers generated from the surface can be efficiently collected. 4H-Sic has a bandgap of 3.26eV and is immune to visible light background noise. Also, 4H-Sic detectors usually have very good radiation hardness and very low noise, which is very important for space applications where the signal is very weak. The E W photodiodes presented in this paper are based on Schottky structures. Platinum (Pt) and Nickel (Ni) are selected as the Schottky contact metals, which have the highest electron work functions (5.65eV and 5.15eV, respectively) among all the known metals on 4H-Sic.

  9. Depletion of deep marine food patches forces divers to give up early.

    PubMed

    Thums, Michele; Bradshaw, Corey J A; Sumner, Michael D; Horsburgh, Judy M; Hindell, Mark A

    2013-01-01

    Many optimal foraging models for diving animals examine strategies that maximize time spent in the foraging zone, assuming that prey acquisition increases linearly with search time. Other models have considered the effect of patch quality and predict a net energetic benefit if dives where no prey is encountered early in the dive are abandoned. For deep divers, however, the energetic benefit of giving up is reduced owing to the elevated energy costs associated with descending to physiologically hostile depths, so patch residence time should be invariant. Others consider an asymptotic gain function where the decision to leave a patch is driven by patch-depletion effects - the marginal value theorem. As predator behaviour is increasingly being used as an index of marine resource density and distribution, it is important to understand the nature of this gain function. We investigated the dive behaviour of the world's deepest-diving seal, the southern elephant seal Mirounga leonina, in response to patch quality. Testing these models has largely been limited to controlled experiments on captive animals. By integrating in situ measurements of the seal's relative lipid content obtained from drift rate data (a measure of foraging success) with area-restricted search behaviour identified from first-passage time analysis, we identified regions of high- and low-quality patches. Dive durations and bottom times were not invariant and did not increase in regions of high quality; rather, both were longer when patches were of relatively low quality. This is consistent with the predictions of the marginal value theorem and provides support for a nonlinear relationship between search time and prey acquisition. We also found higher descent and ascent rates in high-quality patches suggesting that seals minimized travel time to the foraging patch when quality was high; however, this was not achieved by increasing speed or dive angle. Relative body lipid content was an important

  10. Interfacial atomic site characterization by photoelectron diffraction for 4H-AlN/4H-SiC(11\\bar{2}0) heterojunction

    NASA Astrophysics Data System (ADS)

    Maejima, Naoyuki; Horita, Masahiro; Matsui, Hirosuke; Matsushita, Tomohiro; Daimon, Hiroshi; Matsui, Fumihiko

    2016-08-01

    The interfacial atomic structure of an AlN thin film on a nonpolar 4H-SiC(11\\bar{2}0) substrate grown by atomic Al and N plasma deposition was studied by photoelectron diffraction and spectroscopy. The epitaxial growth of the thin film was confirmed by the comparison of element-specific photoelectron intensity angular distributions (PIADs). Depth profiles were analyzed by angle-resolved constant-final-state-mode X-ray photoelectron spectroscopy (AR-XPS). No polar angular dependence was observed in Al 2p spectra, while an additional intermixing component was found in interface-sensitive N 1s spectra. The site-specific N 1s PIADs for the AlN film and an intermixing component were derived from two N 1s PIADs with different binding energies. We attributed the intermixing component to SiN interfacial layer sites. In order to prevent SiN growth at the interface, we deposited Al on the SiC(11\\bar{2}0) substrate prior to the AlN growth. A significant reduction in the amount of intermixing components at the AlN/SiC interface was confirmed by AR-XPS.

  11. Computer-aided patch planning for treatment of complex coarctation of the aorta

    NASA Astrophysics Data System (ADS)

    Rietdorf, Urte; Riesenkampff, Eugénie; Kuehne, Titus; Huebler, Michael; Meinzer, Hans-Peter; Wolf, Ivo

    2009-02-01

    Between five and eight percent of all children born with congenitally malformed hearts suffer from coarctations of the aorta. Some severe coarctations can only be treated by surgical repair. Untreated, this defect can cause serious damage to organ development or even lead to death. Patch repair requires open surgery. It can affect patients of any age: newborns with severe coarctation and/or hypoplastic aortic arch as well as older patients with late diagnosis of coarctation of the aorta. Another patient group are patients of varying age with re-coarctation of the aorta or hypoplastic aortic arch after surgical and/or interventional repair. If anatomy is complex and interventional treatment by catheterization, balloon angioplasty or stent placement is not possible, surgery is indicated. The choice of type of surgery depends not only on the given anatomy but also on the experience the surgical team has with each method. One surgical approach is patch repair. A patch of a suitable shape and size is sewed into the aorta to expand the aortic lumen at the site of coarctation. At present, the shape and size of the patch are estimated intra-operatively by the surgeon. We have developed a software application that allows planning of the patch pre-operatively on the basis of magnetic resonance angiographic data. The application determines the diameter of the coarctation and/or hypoplastic segment and constructs a patch proposal by calculating the difference to the normal vessel diameter pre-operatively. Evaluation of MR angiographic datasets from 12 test patients with different kinds of aortic arch stenosis shows a divergence of only (1.5+/-1.2) mm in coarctation diameters between manual segmentations and our approach, with comparable time expenditure. Following this proposal the patch can be prepared and adapted to the patient's anatomy pre-operatively. Ideally, this leads to shorter operation times and a better long-term outcome with a reduced rate of residual stenosis and

  12. Transcatheter patch occlusion of experimental atrial septal defects.

    PubMed

    Sideris, Eleftherios B; Sideris, Chrysoula E; Stamatelopoulos, Stamatis F; Moulopoulos, Spyridon D

    2002-11-01

    The effectiveness and safety of transcatheter patch atrial septal defect (ASD) occlusion were studied in 20 piglets. Experimental atrial septal defects were created by foramen ovale dilation. ASDs were corrected by polyurethane patches of two types (flat and sleeve). Specially made balloon catheters supported the patches for periods varying from 1 to 6 days; after this period, the supporting catheters were withdrawn and the patches were released. All transcatheter patches were safely embedded in the atrial septum 48 hr or more after implantation. All defects were fully occluded. One patch became infected. The transcatheter patch experimental ASD occlusion method was found effective and safe, potentially applicable in the occlusion of human ASDs. PMID:12410521

  13. Analysis of habitat selection studies with multiple patches within cover types

    USGS Publications Warehouse

    Otis, D.L.

    1997-01-01

    Current statistical methods are inadequate for evaluation of the relation between spatial pattern of the landscape and observed patterns of habitat use by individuals or populations. For example, traditional habitat selection analysis methods do not use information about the size and distribution of the several patches of each cover type that may exist within the study area. Statistical tests are presented for hypotheses about disproportional use of cover types and patches within cover types. These tests require that use of individual patches is recorded, as well as the size of individual patches. Different designs are considered in which there are (1) single or multiple samples of use, and (2) equal or unequal habitat availability. Formulas for calculating Type II statistical errors of the tests are presented and Monte Carlo simulation is used to assess the accuracy of the formulas and to check the Type I error rates of the proposed test statistics. With adequate sample sizes, Type II error formulas can be a useful tool for planning of habitat selection studies. An example analysis is presented of a hypothetical study of habitat selection by ring-necked pheasants (Phasianus colchicus) in a Midwestern landscape. The proposed tests also represent a contribution toward bringing together concepts of landscape ecology and wildlife habitat selection.

  14. Deep patch technique for landslide repair. Final report

    SciTech Connect

    Helwany, B.M.

    1994-10-01

    The report describes the laboratory testing of the `USFS deep patch` technique and a CTI modification of this technique for repairing landslides with geosynthetic reinforcement. The technique involves replacing sections of roadway lost due to landslides on top of a geosynthetically-reinforced embankment. The CTI modification involves replacing the reinforced slope with a geosynthetically-reinforced retaining wall with a truncated base. Both techniques rely on the cantilevering ability of the reinforced mass to limit the load on the foundation with a high slide potential. The tests with road base showed that (1) both the USFS and CTI repair reduced effectively the adverse effects of local landsliding on the highway pavement by preventing crack propagation; (2) the USFS repair increased the stability of the repaired slope, which was in progressive failure, by reducing the stresses exerted on it; and (3) the CTI repair produced substantially greater stresses on its foundation due to the truncated base of the reinforced mass.

  15. The time dependence of reversed archeomagnetic flux patches

    NASA Astrophysics Data System (ADS)

    Terra-Nova, Filipe; Amit, Hagay; Hartmann, Gelvam A.; Trindade, Ricardo I. F.

    2015-02-01

    Archeomagnetic field models may provide important insights to the geodynamo. Here we investigate the existence and mobility of reversed flux patches (RFPs) in an archeomagnetic field model. We introduce topological algorithms to define, identify, and track RFPs. In addition, we explore the relations between RFPs and dipole changes and apply robustness tests to the RFPs. In contrast to previous definitions, patches that reside on the geographic equator are adequately identified based on our RFPs definition. Most RFPs exhibit a westward drift and migrate toward higher latitudes. Undulations of the magnetic equator and RFPs oppose the axial dipole moment (ADM). Filtered models show a tracking behavior similar to the nonfiltered model, and surprisingly new RFPs occasionally emerge. The advection and diffusion of RFPs have worked in unison to yield the decrease of the ADM at recent times. The absence of RFPs in the period 550-1440 A.D. is related to a low in intermediate degrees of the geomagnetic power spectrum. We thus hypothesize that the RFPs are strongly dependent on intermediate spherical harmonic degrees 4 and above.

  16. The time dependence of reversed archeomagnetic flux patches

    NASA Astrophysics Data System (ADS)

    Terra-Nova, Filipe; Amit, Hagay; Hartmann, Gelvam A.; Trindade, Ricardo I. F.

    2016-04-01

    Archeomagnetic field models may provide important insights to the geodynamo. Here we investigate the existence and mobility of reversed flux patches (RFPs) in archeomagnetic field model CALS3k.4b of Korte and Constable (2011; PEPI, 188, 247-259). We introduce topological algorithms to define, identify and track RPFs. In addition, we explore the relations between RFPs and dipole changes, and apply robustness tests to the RFPs. In contrast to previous definitions, patches that reside on the geographic equator are adequately identified based on our RFPs definition that takes the magnetic equator as a reference. Most RFPs exhibit a westward drift and migrate towards higher latitudes. Undulations of the magnetic equator and RFPs oppose the axial dipole moment (ADM). Filtered models show a tracking behaviour similar to the non-filtered model, and surprisingly new RFPs occasionally emerge. The advection and diffusion of RFPs have worked in unison to yield the decrease of the ADM at recent times. The absence of RFPs in the period 550-1440 AD is related to a low in intermediate degrees of the geomagnetic power spectrum. We thus hypothesize that the RFPs are strongly dependent on intermediate spherical harmonic degrees 4 and above. Comparison of tracking of RFPs among various archeomagnetic field models was also performed and gives more complex results.

  17. Effect of stiffness and thickness ratio of host plate and piezoelectric patches on reduction of the stress concentration factor

    NASA Astrophysics Data System (ADS)

    Fesharaki, Javad Jafari; Madani, Seyed Ghasem; Golabi, Sa'id

    2016-06-01

    This paper focuses on the effects of stiffness ratio and thickness ratio on reducing stress concentration factor using piezoelectric patches in a rectangular plate with a hole, as a classical shape. Various locations of actuators and induction of positive/negative strains into the host plate are investigated and the best location of patches is presented. The study investigated the ratio effects and piezoelectric patches bounded on a rectangular host plate having various thicknesses and materials. Results show that the best position of actuators varies based on values of thickness and stiffness ratios of the host plate and piezoelectric patches. Also, the location of maximum stress concentration is transmitted from top and bottom of the hole to another point around the edge by changing the location of the piezoelectric actuators. To verify the results, some experimental tests are applied. The results show good agreement between the finite element analysis and experimental tests.

  18. Formulation, in vitro, and in vivo evaluation of matrix-type transdermal patches containing olanzapine.

    PubMed

    Aggarwal, Geeta; Dhawan, Sanju; Harikumar, S L

    2013-01-01

    Transdermal patches of olanzapine were aimed to be prepared to overcome the side effects by oral application. The strategy was formulation of eudragit-based polymeric films to prepare transdermal patches by using nonionic (span-20), anionic (sodium lauryl sulfate), cationic surfactant (benzalkonium chloride), and vegetable oil (olive oil) as permeation enhancers. The patches were subjected to physicochemical, in vitro release and ex vivo permeation studies. On the basis of in vitro release performance, ERL 100:ERS 100 in the ratio of 3:2 was selected for incorporation of permeation enhancers. The permeation studies showed that formulation containing 10% span 20 (OD3) exhibited greatest cumulative amount of drug permeated (19.02 ± 0.21 mg) in 72 h, so OD3 was concluded as optimized formulation and assessed for pharmacokinetic, pharmacodynamic, and skin irritation potential. In vivo studies of optimized olanzapine patch in rabbit model revealed prolongation of action with Frel 116.09% during 72-h study period. Neuroleptic efficacy of transdermal patch was comparable to oral formulation during rotarod and grip test in Wistar albino rats with no skin irritation. Thus, developed formulation of olanzapine is expected to improve the patient compliance, form better dosage regimen, and provide maintenance therapy to psychotic patients. PMID:21913873

  19. Patch network criteria for dispersal-limited endemic birds of South American temperate rain forest.

    PubMed

    Castellón, Traci D; Sieving, Kathryn E

    2007-12-01

    We developed a set of simple empirically based criteria for distinguishing forest patch configurations that we expected to support persistent populations of two endemic Tapaculo species with limited dispersal ability (Chucao Tapaculos [Scelorchilus rubecula] and Black-throated Huet-huets [Pteroptochos tarnii]) in South American temperate rain forest. The criteria address sustainable population sizes (tested using population viability analysis), habitat area needed to support sustainable populations, and measures of functional connectivity derived from radiotelemetry data and patch occupancy models. We then applied the criteria in three real-world demonstration landscapes, first, to predict numbers of breeding territories potentially accommodated within patch configurations and, second, to evaluate increases that might be achieved if landscape connections among isolated patches were restored (e.g., using corridors). The best connected of the three demonstration landscapes was predicted to support large sustainable populations without intervention to restore connectivity, whereas none of the patch configurations was sustainable in the most fragmented landscape, with or without corridor restoration. Notably, however, corridor restoration in the landscape with an intermediate fragmentation level was expected to quadruple the sustainable Chucao population and potentially prevent regional Huet-huet extinction. Thus, our network criteria provide a simple approach for developing and evaluating spatially explicit prescriptions for conservation planning in this highly endangered biome. The criteria may be especially useful for discriminating among landscapes where restoration of connectivity is, or is not, an appropriate course of action. PMID:18213959

  20. Ultra-High Voltage 4H-SiC Bi-Directional Insulated Gate Bipolar Transistors

    NASA Astrophysics Data System (ADS)

    Chowdhury, Sauvik

    4H- Silicon Carbide (4H-SiC) is an attractive material for power semiconductor devices due to its large bandgap, high critical electric field and high thermal conductivity compared to Silicon (Si). For ultra-high voltage applications (BV > 10 kV), 4H-SiC Insulated Gate Bipolar Transistors (IGBTs) are favored over unipolar transistors due to lower conduction losses. With improvements in SiC materials and processing technology, promising results have been demonstrated in the area of conventional unidirectional 4H-SiC IGBTs, with breakdown voltage ratings up to 27 kV. This research presents the experimental demonstration of the world's first high voltage bi-directional power transistors in 4H-SiC. Traditionally, four (two IGBTs and two diodes) or two (two reverse blocking IGBTs) semiconductor devices are necessary to yield a bidirectional switch. With a monolithically integrated bidirectional switch as presented here, the number of semiconductor devices is reduced to only one, which results in increased reliability and reduced cost of the overall system. Additionally, by using the unique dual gate operation of BD-IGBTs, switching losses can be reduced to a small fraction of that in conventional IGBTs, resulting in increased efficiency. First, the performance limits of SiC IGBTs are calculated by using analytical methods. The performance benefits of SiC IGBTs over SiC unipolar devices and Si IGBTs are quantified. Numerical simulations are used to optimize the unit cell and edge termination structures for a 15 kV SiC BD-IGBT. The effect of different device parameters on BD-IGBT static and switching performance are quantified. Second, the process technology necessary for the fabrication of high voltage SiC BD-IGBTs is optimized. The effect of different process steps on parameters such as breakdown voltage, carrier lifetime, gate oxide reliability, SiO2-SiC interface charge density is quantified. A carrier lifetime enhancement process has been optimized for lightly doped

  1. Development of a self-stressing NiTiNb shape memory alloy (SMA)/fiber reinforced polymer (FRP) patch

    NASA Astrophysics Data System (ADS)

    El-Tahan, M.; Dawood, M.; Song, G.

    2015-06-01

    The objective of this research is to develop a self-stressing patch using a combination of shape memory alloys (SMAs) and fiber reinforced polymer (FRP) composites. Prestressed carbon FRP patches are emerging as a promising alternative to traditional methods to repair cracked steel structures and civil infrastructure. However, prestressing these patches typically requires heavy and complex fixtures, which is impractical in many applications. This paper presents a new approach in which the prestressing force is applied by restraining the shape memory effect of NiTiNb SMA wires. The wires are subsequently embedded in an FRP overlay patch. This method overcomes the practical challenges associated with conventional prestressing. This paper presents the conceptual development of the self-stressing patch with the support of experimental observations. The bond between the SMA wires and the FRP is evaluated using pull-out tests. The paper concludes with an experimental study that evaluates the patch response during activation subsequent monotonic tensile loading. The results demonstrate that the self-stressing patch with NiTiNb SMA is capable of generating a significant prestressing force with minimal tool and labor requirements.

  2. Wideband Patch Antenna for Land based Vehicles

    NASA Astrophysics Data System (ADS)

    Gangwar, R. P. S.; Dutt, Sanjay

    2016-07-01

    In this paper, an irregular pentagon shaped patch antenna has been presented. The proposed antenna operates over a wide band in frequency range from 12 to 26 GHz with VSWR < 2. It has a partial ground plane with two-inverted L and one I shaped slots in the radiation patch to attain wide bandwidth. The antenna consists of FR4 epoxy as a dielectric substrate with dielectric constant 4.4 and loss tangent 0.002. The size of the antenna is 30 × 30 × 1.57 mm3 and is fed by the microstrip line. The size of the fabricated proposed antenna is smaller than that of the antenna under reference (elliptical radiating patch with defected ground plane). The simulation has been done using high frequency structure simulator (HFSS) which is a finite element method (FEM) based tool. The proposed antenna exhibits the return loss of 21.85, 28.03 and 29.14 dB and gain of 6.6, 5.67 and 7.0 dB at resonant frequencies 16.7, 19.00 and 21.4 GHz, respectively. The bandwidth of the antenna is 10 GHz with normalized radiation efficiencies of 65, 69 and 70 % at corresponding resonant frequencies. The measured results of the fabricated proposed antenna have been compared with the simulated results and there has been a close agreement between both the results. Also the simulated results of the proposed antenna have been compared with the antenna under reference and it is found that the performance of the proposed antenna is far better. The proposed antenna can be used for land based vehicles in both Ku-band (12-18 GHz) and K-band (18-26 GHz).

  3. Analyzing Milestones in Smoking Cessation: Illustration in a Nicotine Patch Trial in Adult Smokers

    ERIC Educational Resources Information Center

    Shiffman, Saul; Scharf, Deborah M.; Shadel, William G.; Gwaltney, Chad J.; Dang, Qianyu; Paton, Stephanie M.; Clark, Duncan B.

    2006-01-01

    Tests of addiction treatments seldom reveal where treatment exercises its effect (i.e., promoting initial abstinence, preventing lapses, and/or impeding progression from lapse to relapse). The authors illustrate analyses distinguishing effects on these milestones in a randomized trial of high-dose nicotine patch (35 mg; n = 188) versus placebo (n…

  4. How reliable do fibre Bragg grating patches perform as strain sensors?

    NASA Astrophysics Data System (ADS)

    Schlüter, Vivien Gisela; Kusche, Nadine; Habel, Wolfgang R.

    2010-09-01

    In Germany, the first guideline for the use of fibre Bragg grating strain sensors, "Optical Strain Sensor based on Fibre Bragg Grating" [1], has been developed by the GESA guideline group of VDI "The Association of German Engineers" and published by Beuth Verlag. This guideline provides the basic specifications of these sensor types and the sensor characteristics which have to be known for a reliable sensor performance. In conformity to this guideline, experimental investigations on the strain transfer characteristics of fibre Bragg grating patches have been carried out. A comparison between patches and resistance strain gauges during tensile tests and combined temperature and tensile loading was carried out. The evaluated strain gauge factor and the temperature sensitivity of the strain gauge factor have been compared to the manufacturer's data. The overall performance of the patches has been evaluated. The experimental investigations showed that there are partial disagreements between the manufacturer's specifications and the observed characteristics.

  5. Reduction in Stress Intensity Factor of a Compact Tension Specimen by Bonding Symmetrical GFRP Patches

    NASA Astrophysics Data System (ADS)

    Shinde, P. S.; Tripathi, V. K.; Singh, K. K.; Sarkar, P. K.; Kumar, P.

    2013-10-01

    Reduction in stress intensity factor (SIF) of an acrylic compact tension (CT) specimen is studied by symmetrical bonding of glass fiber reinforced plastic (GFRP) patches on both sides of the specimen. The CT specimen was designed and developed to satisfy all dimensional constraints for plane strain condition. A suitable load fixture using dead weight for higher accuracy was designed for the purpose. The numerical and experimental analysis of CT specimen with varying geometry of the GFRP patches was carried out to analyze their effect on SIF of the specimen. The strain near the crack tip was measured by bonding a small strain gauge to estimate the equivalent SIF of the CT specimen. The test data was compared with the results of numerical analysis carried out using ANSYS software. The variation in strain value determined through theoretical analysis, numerical evaluation and experimental measurement is within 7 %. The equivalent SIF was found to be drastically reduced after bonding the CT specimen with GFRP patches.

  6. Dielectric studies of environmentally friendly and flexible lignocelluloses fibrils for miniaturization of patch antenna

    NASA Astrophysics Data System (ADS)

    Razaq, Aamir; Khan, Asim Ali; Asif, M. H.; Iqbal, Shahid; Ali, Jawad; Manzoor, Faisal; Awan, M. S.

    2015-10-01

    Naturally, existing lignocelluloses fibers showed outstanding potential in paper industry and other conventional applications. On the other hand, lignocellulose fibers are suitable candidate for high-tech applications under the scope of abundance, flexibility, light-weight and environment friendliness. In this study, paper sheets were prepared from lignocelluloses fibers extracted from self-growing plant, typha angustifolia. Lignocelluloses paper sheets were characterized for scanning electron microscopy (SEM), universal testing machine (UTM) and vector network analyzer (VNA). Flexible paper sheets displayed a tensile strength of 9.1 MPa and further used as a substrate in patch antenna to observe dielectric characteristics. The patch antenna is designed at 5.1 GHz which showed return loss less than -10 dB and dielectric constant 3.71. The use of lignocelluloses paper sheet as a substrate in patch antenna will provide the opportunity of miniaturization of size and weight in comparison of a jean substrate based antenna.

  7. Biological cell controllable patch-clamp microchip

    NASA Astrophysics Data System (ADS)

    Penmetsa, Siva; Nagrajan, Krithika; Gong, Zhongcheng; Mills, David; Que, Long

    2010-12-01

    A patch-clamp (PC) microchip with cell sorting and positioning functions is reported, which can avoid drawbacks of random cell selection or positioning for a PC microchip. The cell sorting and positioning are enabled by air bubble (AB) actuators. AB actuators are pneumatic actuators, in which air pressure is generated by microheaters within sealed microchambers. The sorting, positioning, and capturing of 3T3 cells by this type of microchip have been demonstrated. Using human breast cancer cells MDA-MB-231 as the model, experiments have been demonstrated by this microchip as a label-free technical platform for real-time monitoring of the cell viability.

  8. Aspects and applications of patched grid calculations

    NASA Technical Reports Server (NTRS)

    Walters, R. W.; Switzer, G. F.; Thomas, J. L.

    1986-01-01

    Patched grid calculations within the framework of an implicit, flux-vector split upwind/relaxation algorithm for the Euler equations are presented. The effect of a metric-discontinuous interface on the convergence rate of the algorithm is discussed along with the spatial accuracy of the solution and the effect of curvature along an interface. Results are presented and discussed for the free-stream problem, shock reflection problem, supersonic inlet with a 5 degree ramp, aerodynamically choked inlet, and three-dimensional analytic forebody.

  9. Complex suicide with homemade nicotine patches.

    PubMed

    Lardi, C; Vogt, S; Pollak, S; Thierauf, A

    2014-03-01

    Suicide by self-poisoning is rather common around the world. This paper presents an exceptional complex suicide in which nicotine was applied in the form of self-made patches soaked with an extraction from fine-cut tobacco. In addition, the 51-year-old suicide victim took a lethal dose of diphenhydramine. Toxicological analysis also revealed the presence of tetrazepam in subtherapeutic concentrations. The scene of death suggested an autoerotic accident at first, as the body was tied with tapes, cables and handcuffs. As a result of the entire investigations, the fatality had to be classified as a suicidal intoxication by nicotine and diphenhydramine. PMID:24439154

  10. Anharmonic vibrations of the dicarbon antisite defect in 4H-SiC

    SciTech Connect

    Yan, F.; Devaty, R. P.; Choyke, W. J.; Gali, A.; Kimoto, T.; Ohshima, T.; Pensl, G.

    2012-03-26

    Dicarbon antisite defects were created by either electron irradiation or ion implantation into 4H-SiC. The no-phonon lines from the dicarbon antisite defect center were observed with their phonon replicas. The stretch frequencies of the defect were observed up to the fifth harmonic. The Morse potential model accounts for the anharmonicity quite well and gives a very good prediction of the vibration energies up to the fifth harmonic with an error of less than 1%. First principles calculations show that the model of a dicarbon antisite defect along with its four nearest neighboring carbon atoms can explain the observed anharmonicity.

  11. Light triggered 4H-SiC thyristors with an etched guard ring assisted JTE

    NASA Astrophysics Data System (ADS)

    Dheilly, Nicolas; Planson, Dominique; Pâques, Gontran; Scharnholz, Sigo

    2012-07-01

    In this paper, an original termination, the etched guard ring assisted junction termination extension (JTE), is demonstrated on 4H-SiC light triggered thyristors. The termination structure, designed with finite element simulations, is detailed and particular attention is paid to the sensitivity to etching depth uncertainties. The fabrication processes and the electrical characterization of the devices are described. A blocking voltage of 6.3 kV is attained, validating the principle of the termination. Switching and quasi static on-state measurements are also performed to investigate the functionality of the thyristors.

  12. Atomic oxidation of large area epitaxial graphene on 4H-SiC(0001)

    SciTech Connect

    Velez-Fort, E.; Ouerghi, A.; Silly, M. G.; Sirtti, F.; Eddrief, M.; Marangolo, M.; Shukla, A.

    2014-03-03

    Structural and electronic properties of epitaxial graphene on 4H-SiC were studied before and after an atomic oxidation process. X-ray photoemission spectroscopy indicates that oxygen penetrates into the substrate and decouples a part of the interface layer. Raman spectroscopy demonstrates the increase of defects due to the presence of oxygen. Interestingly, we observed on the near edge x-ray absorption fine structure spectra a splitting of the π* peak into two distinct resonances centered at 284.7 and 285.2 eV. This double structure smears out after the oxidation process and permits to probe the interface architecture between graphene and the substrate.

  13. Structural defects in electrically degraded 4H-SiC p+/n-/n+ diodes

    NASA Astrophysics Data System (ADS)

    Persson, P. O. A.; Hultman, L.; Jacobson, H.; Bergman, J. P.; Janzen, E.; Molina-Aldareguia, J. M.; Clegg, W. J.; Tuomi, T.

    2002-06-01

    Triangular structural defects are occasionally generated during the long-term operation of 4H-SiC pin diodes and degrade the forward characteristics of the diode. We have used synchrotron white beam x-ray topography, scanning electron microscopy, in situ cathodo luminescence, and transmission electron microscopy to characterize the structure and formation of these defects. It is shown that the defects are stacking faults on the (0001) basal planes, bound by partial dislocations with Burgers vectors 1/3<1010> and 1/3<0110>. These partials are suggested to form by the dissociation of existing dislocations.

  14. Dynamic characteristics of 4H-SiC drift step recovery diodes

    SciTech Connect

    Ivanov, P. A. Kon’kov, O. I.; Samsonova, T. P.; Potapov, A. S.; Grekhov, I. V.

    2015-11-15

    The dynamic characteristics of 4H-SiC p{sup +}–p–n{sub 0}–n{sup +} diodes are experimentally studied in the pulsed modes characteristic of the operation of drift step recovery diodes (DSRD-mode). The effect of the subnanosecond termination of the reverse current maintained by electron-hole plasma preliminarily pumped by a forward current pulse is analyzed in detail. The influence exerted on the DSRD effect by the amplitude of reverse-voltage pulses, the amplitude and duration of forward-current pulses, and the time delay between the forward and reverse pulses is demonstrated and accounted for.

  15. 4H SiC BJTs with current gain of 110

    NASA Astrophysics Data System (ADS)

    Zhang, Qingchun (Jon); Agarwal, Anant; Burk, Al; Geil, Bruce; Scozzie, Charles

    2008-07-01

    4H-SiC BJTs with a common emitter current gain of 110 have been demonstrated. The high current gain was attributed to a thin base of 0.25 μm which reduces the carrier recombination in the base region. The device open base breakdown voltage (BVCEO) of 270 V was much less than the open emitter breakdown voltage (BVCBO) of 1560 V due to the emitter leakage current multiplication from the high current gain by "transistor action" of BJTs. The device has shown minimal gain degradation after electrical stress at high current density of >200 A/cm2up to 25 h.

  16. High quality interlayer dielectric for 4H SiC DMOSFETs

    NASA Astrophysics Data System (ADS)

    Okayama, T.; Arthur, S. D.; Waldrab, P.; Rao, Mulpuri V.

    2007-11-01

    In this work useful weight percentages of boron and phosphorus in boro-phospho-silicate-glass (BPSG) interlayer dielectric (ILD) films to getter mobile ions effectively in 4H-SiC DMOSFET structures are developed, considering the limitations, such as the required low glass flow temperature, and the possible hygroscopic nature of the films and formation of crystalline BPO4 particles, which may occur for high B and P weight percentages. The B and P weight percentage viscous flow temperature contours and empirical inequalities representing the above-mentioned limitations are developed and discussed. Results of this work are useful for both silicon and compound semiconductor device technologies.

  17. Development of 10 kV 4H-SiC JBS diode with FGR termination

    NASA Astrophysics Data System (ADS)

    Runhua, Huang; Yonghong, Tao; Pengfei, Cao; Ling, Wang; Gang, Chen; Song, Bai; Rui, Li; Yun, Li; Zhifei, Zhao

    2014-07-01

    The design, fabrication, and electrical characteristics of the 4H-SiC JBS diode with a breakdown voltage higher than 10 kV are presented. 60 floating guard rings have been used in the fabrication. Numerical simulations have been performed to select the doping level and thickness of the drift layer and the effectiveness of the edge termination technique. The n-type epilayer is 100 μm in thickness with a doping of 6 × 1014 cm-3. The on-state voltage was 2.7 V at JF = 13 A/cm2.

  18. 4H-SiC junction-barrier Schottky diodes with high forward current densities

    NASA Astrophysics Data System (ADS)

    Tone, Kiyoshi; Zhao, Jian H.; Weiner, Maurice; Pan, Menghan

    2001-07-01

    4H-SiC junction-barrier Schottky (JBS) diodes blocking 1000 V have been fabricated. I-V characteristics have been evaluated at room temperature and 255 °C in comparison with the Schottky barrier (SB) and pin diodes fabricated on the same wafer. While the low reverse leakage confirms the functioning of JBS, the high forward current densities of 630 and 210 A cm-2 at 4.0 V at room temperature and 255 °C, respectively, with only ~20% reduction from those of the SB diodes, clearly demonstrate that the SiC JBS diodes can be fabricated with acceptable sacrifice in the forward current capacities.

  19. Improvements in Realizing 4H-SiC Thermal Neutron Detectors

    NASA Astrophysics Data System (ADS)

    Issa, F.; Vervisch, V.; Ottaviani, L.; Szalkai, D.; Vermeeren, L.; Lyoussi, A.; Kuznetsov, A.; Lazar, M.; Klix, A.; Palais, O.; Hallén, A.

    2016-02-01

    In this work we presented two types of 4H-SiC semiconductor detectors (D1 and D2) both based on ion implantation of 10B inside the aluminum metallic contact. The first detector shows a high leakage current after the implantation and low signal to noise ratio. However, improvements concerning the implantation parameters and the distance between the implanted 10B thermal neutron converter layer and the active pn-junction have led to low leakage current and thus to higher signal to noise ratio. This proves the strength of this new method of realizing sensitive SiC-based thermal neutron detectors.

  20. Transient collector modulation of 4H-SiC BJTs during switch-on process

    NASA Astrophysics Data System (ADS)

    Yuferev, Valentin S.; Levinshtein, Michael E.; Ivanov, Pavel A.; Zhang, Jon Q.; Palmour, John W.

    2016-09-01

    Main physical features of the collector resistance modulation processes have been studied via a one-dimensional simulation for n+-p-n0-n+ 4H-SiC bipolar junction transistor. The motion dynamics of minority carriers (holes) across the n0 collector layer during the switch-on process is traced. It is demonstrated that the effective modulation of the collector resistance is only possible in the case of a rather fast transistor switch-on. A necessary condition for the fast switch-on is the large amplitude and short leading edge of the base current pulse.