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Sample records for regular khat chewing

  1. Prevalence of and factors associated with regular khat chewing among university students in Ethiopia

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    Astatkie A

    2015-02-01

    Full Text Available Ayalew Astatkie,1 Meaza Demissie,2 Yemane Berhane,2 Alemayehu Worku2,3 1School of Public and Environmental Health, College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia; 2Addis Continental Institute of Public Health, Addis Ababa, Ethiopia; 3School of Public Health, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia Purpose: Khat (Catha edulis is commonly chewed for its psychostimulant and euphorigenic effects in Africa and the Arabian Peninsula. Students use it to help them study for long hours especially during the period of examination. However, how regularly khat is chewed among university students and its associated factors are not well documented. In this article we report on the prevalence of and factors associated with regular khat chewing among university students in Ethiopia. Methods: We did a cross-sectional study from May 20, 2014 to June 23, 2014 on a sample of 1,255 regular students recruited from all campuses of Hawassa University, southern Ethiopia. The data were collected using self-administered questionnaires. We analyzed the data to identify factors associated with current regular khat chewing using complex sample adjusted logistic regression analysis. Results: The prevalence of current regular khat chewing was 10.5% (95% confidence interval [CI]: 6.1%–14.9%. After controlling for sex, religion, year of study, having a father who chews khat, cigarette smoking and alcohol drinking in the adjusted logistic regression model, living off-campus in rented houses as compared to living in the university dormitory (adjusted odds ratio [95% CI] =8.09 [1.56–42.01], and having friends who chew khat (adjusted odds ratio [95% CI] =4.62 [1.98–10.74] were found to significantly increase the odds of current regular khat use. Conclusion: Students living outside the university campus in rented houses compared to those living in dormitory and those with khat chewing peers are more likely to use

  2. Prevalence of Khat chewing and associated factors in Ethiopia ...

    African Journals Online (AJOL)

    user

    Ethiopia, Kenya, Yemen, Somalia, Sudan, South Africa and Madagascar; it ... effects of khat chewing; for instance, a study revealed .... cervical cancer screening coverage in women, and provision ..... Socio-economic effects of khat chewing in.

  3. Prevalence, Reasons, and Perceived Effects of Khat Chewing ...

    African Journals Online (AJOL)

    Background: The estimate of the number of people chewing Khat globally ranges from 5 to. 10 million people. ..... Math. 50 (12.5). Physical education. 38 (9.5). Shift of study. Regular. 229 (57.2) ..... Health Studies: A Practical Manual. Geneva: ...

  4. Khat chewing and cirrhosis in Somaliland: Case series

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    Hawa D. Mahamoud

    2016-07-01

    Results: Eight Somali men aged 27–70 years living in Somaliland were identified with cirrhosis of otherwise unknown cause. All chewed khat habitually for many years (15–128 bundles per day times years of use. A liver biopsy of one man was consistent with khat hepatotoxicity. Four of the eight men died during the study period.Conclusion: Khat chewing may be associated with health consequences including severe hepatotoxicity with cirrhosis.

  5. Determinants of alcohol use and khat chewing among Hawassa ...

    African Journals Online (AJOL)

    Background: Students' alcohol and khat use have been associated with various health related problems. However, its magnitude and associated factors among Ethiopian students are not yet well documented. Objective: The study aimed to assess the prevalence of alcohol use, khat chewing and its associated factors ...

  6. INTRODUCTION The habit of chewing khat by the inhabitants of ...

    African Journals Online (AJOL)

    hi-tech

    2000-06-01

    Jun 1, 2000 ... structure of cathinone is similar to amphetamine, and khat produces an ... activation of the serotonin pathways may have an important role in action of ... Pharm. Chem. 1961; 3:323-352. 3. Hughes, P. Khat chewing in Yemen.

  7. Prevalence, Reasons, and Perceived Effects of Khat Chewing ...

    African Journals Online (AJOL)

    Prevalence, Reasons, and Perceived Effects of Khat Chewing Among Students of a College in Gondar Town, Northwestern Ethiopia: A Cross‑sectional Study. ... Among chewers, 83.1% (108/130) reported they faced problem associated to sleep disturbance, 82.3% (107/130) loss of appetite, and 80.8% (105/130) ...

  8. Cigarette smoking and Khat chewing among college students in ...

    African Journals Online (AJOL)

    Objective: To assess the prevalence and risk factors of cigarette smoking and khat chewing among college students. Methods: A cross sectional study was conducted in January 2001 in the four colleges found in North West Ethiopia. Students in each year of study were selected by systematic sampling technique.

  9. Cigarette smoking and khat chewing among University instructors in ...

    African Journals Online (AJOL)

    Objective: To assess the prevalence and risk factors of cigarette smoking and khat chewing. Design: College based cross sectional. Setting: Four colleges found in north west Ethiopia namely Gondar College of Medical Sciences, Gondar College of Teachers Education, Bahr Dar University Engineering Faculty, and Bahr ...

  10. Association Between Khat ( Catha edulis ) Chewing and Infection ...

    African Journals Online (AJOL)

    Setting: KEMRI's Centre for Clinical Research (CCR) and St. Michael's Digestive Disease and Medical Care. Subjects: Ninety three cases were selected using Rome III criteria for functional dyspepsia, and the controls (n=93) were matched on age and gender. Results: Khat Chewing was associated with infection with H.

  11. Association between Khat Chewing and Gastrointestinal Disorders ...

    African Journals Online (AJOL)

    The prevalence of gastritis was 580 (57.7%); constipation 235 (23.4%); hemorrhoids 54 (5.4%) and that of dental problems (carries, decay, filling and extraction) was 225 (22.4%) of all study participants. Gastrointestinal disorders were found to be higher among khat chewers, where 64(36.2%) of them had dental problems; ...

  12. Is Khat (Catha edulis) chewing a risk factor for periodontal diseases? A systematic review.

    Science.gov (United States)

    Kalakonda, Butchibabu; Al-Maweri, Sadeq-Ali; Al-Shamiri, Hashem-Motahir; Ijaz, Anum; Gamal, Shukri; Dhaifullah, Esam

    2017-10-01

    Khat (Catha edulis) chewing is a highly prevalent habit in the Arabian Peninsula and East Africa, and has recently spread to Western countries. The association between khat chewing and oral mucosal lesions is well documented in the literature. However, there is no concrete evidence on the association between khat chewing and periodontal disease. The purpose of this systematic review was to analyze the influence of khat chewing on periodontal health. A literature search of PubMed, Scopus and Web of Sciences databases was carried out to identify relevant articles published from 1990 to May 2017. The inclusion criteria were all clinical studies that assessed the relationship between khat chewing and periodontal disease. The search yielded 122 articles, of which 10 were included in this systematic review. Most of the studies exhibited a positive correlation between khat chewing and periodontal disease. Altogether, the analysis of the current evidence reveals that khat chewing is destructive to the periodontium and enhances the risk of periodontal disease progression. However, due to variability of studies, more longitudinal case-controlled studies are highly warranted to establish a causal relation between khat chewing and periodontal disease. Key words: Khat chewing, periodontal health, periodontal disease, risk factor.

  13. Khat chewing and acculturation in East-African migrants living in Frankfurt am Main/Germany.

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    Bongard, Stephan; Nakajima, Motohiro; al'Absi, Mustafa

    2015-04-22

    Khat (Catha edulis, Forsk) is a drug widely used in countries around the Red Sea (East-Africa and Arabian Peninsula). In Germany khat chewing is illegal but nevertheless an often observed habit in immigrants from this region. This study investigates the interrelation between immigrants acculturation processes and traditional khat chewing habits. Sixty-one khat chewers (14 female) from East-African countries were interviewed about their khat chewing habits and acculturation strategy using standardized questionnaires. Results indicate that immigrants׳ khat chewing behaviors are similar to what is common in countries with traditional khat use. But khat chewing tended to be less among immigrants who were relatively more oriented towards their cultures of origin. Chewing khat was subjectively considered to help coping with problems, to forget bad memories and to concentrate better. It was concluded that khat chewing serves a functional use of coping with stressful events in the present or in the past within this sample. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Khat chewing habit among school students of Jazan region, Saudi Arabia.

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    Rashad Mohammed Alsanosy

    Full Text Available BACKGROUND: The use of Khat leaves (Catha edulis in Jazan, southwest of KSA, is prevalent among all segments of the population. OBJECTIVE: This study was conducted to assess the prevalence and predictors of Khat chewing among intermediate and secondary school students of Jazan region. METHODOLOGY: A cross-sectional survey was conducted in late 2011 in Jazan region. A random sample of 3923 students was selected from 72 intermediate and upper secondary schools representing the different educational sectors of the region. A structured self-administered questionnaire was used for data collection. Descriptive statistics, a chi-squared test and logistic regression were performed to examine the prevalence, associations and predictors of Khat chewing. RESULT: The overall Khat chewing prevalence among students was 20.5% (95% C.I.: 19.27-21.79. The prevalence was significantly higher among males, at 33.1% (95% CI: 31.16-35.08, than among females 4.3% (95% C.I.: 3.39-5.31 ( P <0.001. Univariate analysis revealed that gender, age, academic performance, friends' smoking and Khat chewing, and students' smoking status were associated with a significantly high risk of Khat chewing ( P <0.001 for all. The multivariate logistic regression analysis suggested that the most important independent predictors of Khat chewing among the students in our sample were students' smoking status (OR = 13.02, P <0.001, friends' use of Khat (OR = 5.65, P <0.001, gender (OR = 4.62, P <0.001, and friend's use of tobacco (OR = 1.43, P <0.001. CONCLUSION: A significant percentage of students chew Khat. The abuse of Khat is significantly associated with gender, peer influence, and cigarette smoking. Intervention programs are needed to create awareness among school students and to reduce the prevalence of the habit and its unfavorable consequences.

  15. Prevalence of khat chewing and its effect on academic performance in Sidama zone, Southern Ethiopia.

    Science.gov (United States)

    Kassa, Andargachew; Loha, Eskindir; Esaiyas, Atkilt

    2017-03-01

    Khat use is a well-established public health problem in Yemen, Arabian Peninsula, and Ethiopia. Along with its large scale production, the magnitude of khat use is increasing among students. This study was intended to assess the prevalence, determinants, and effect of khat use on academic performance of high school students in Sidama Ethiopia. A cross-sectional study was conducted from April to June 2015. We used a stratified sampling technique to draw a total of 1,577 students. The data was collected using self-administered questionnaires and analyzed using SPSS version 20. Descriptive statistics and logistic regression models were used to determine the prevalence, effects, and predictors of khat use. The life time and current prevalence of khat use were 14.6% and 13%, respectively. Smoking cigarette (AOR=5.1, 95% C.I: 2.3-14.3), drinking alcohol (AOR=3.0, 95% C.I: 1.4-6.3), having a family growing khat (AOR=2.0, 95% C.I: 1.1-2.5), having friend chewing khat (AOR=3. 95% C.I: 2.0-4.6), were some of factors that increased the odds of students' khat use. Student's khat use increased the odds of student's poor academic performance (AOR=2.1, 95% C.I: 1.1-3.9). The prevalence of khat use in high khat producing districts of Sidama and its contribution to poor academic performance demand prompt intervention.

  16. Khat chewing habit among school students of Jazan region, Saudi Arabia.

    Science.gov (United States)

    Alsanosy, Rashad Mohammed; Mahfouz, Mohamed Salih; Gaffar, Abdelrahim Mutwakel

    2013-01-01

    The use of Khat leaves (Catha edulis) in Jazan, southwest of KSA, is prevalent among all segments of the population. This study was conducted to assess the prevalence and predictors of Khat chewing among intermediate and secondary school students of Jazan region. A cross-sectional survey was conducted in late 2011 in Jazan region. A random sample of 3923 students was selected from 72 intermediate and upper secondary schools representing the different educational sectors of the region. A structured self-administered questionnaire was used for data collection. Descriptive statistics, a chi-squared test and logistic regression were performed to examine the prevalence, associations and predictors of Khat chewing. The overall Khat chewing prevalence among students was 20.5% (95% C.I.: 19.27-21.79). The prevalence was significantly higher among males, at 33.1% (95% CI: 31.16-35.08), than among females 4.3% (95% C.I.: 3.39-5.31) ( P academic performance, friends' smoking and Khat chewing, and students' smoking status were associated with a significantly high risk of Khat chewing ( P peer influence, and cigarette smoking. Intervention programs are needed to create awareness among school students and to reduce the prevalence of the habit and its unfavorable consequences.

  17. Khat Chewing Practice and Associated Factors among Adults in Ethiopia: Further Analysis Using the 2011 Demographic and Health Survey.

    Science.gov (United States)

    Haile, Demewoz; Lakew, Yihunie

    2015-01-01

    Khat chewing has become a highly prevalent practice and a growing public health concern in Ethiopia. Although there have been many small scale studies, very limited national information has been available in the general population. This study aimed to identify factors associated with khat chewing practice among Ethiopian adults. The study used the 2011 Ethiopian demographic and health survey data. The survey was cross-sectional by design and used a multistage cluster sampling procedure. Bivariate and multivariable logistic regression models with adjusted odds ratio (AOR) and their 95% confidence intervals (CI) were used to quantify the predictors. The overall khat chewing prevalence was 15.3% (95% CI: 14.90-15.71). Regional variation was observed with the highest in Harari [(53.2% (95% CI: 43.04-63.28)] and lowest in Tigray regional state [(1.1% (95% CI: 0.72-1.66)]. Multivariable analysis showed that Islam followers were 23.8 times more likely to chew khat as compared to Orthodox followers. Being a resident in Oromiya, South Nation, Nationalities and People (SNNP), Gambella, Harari and Dire Dawa regions had 1.9, 1.6, 3.1, 5.2 and 3.5 times higher odds of chewing khat as compared to Addis Ababa residents, respectively. Adults in the age group 45-49 years were 3.6 times more likely to chew khat as compared to 15-19 years. The middle and richest wealth quintiles were 1.3 and 1.5 times more likely to chew khat, respectively, as compared to the poorest category. Rural residents had 1.3 odds of chewing khat than urban residents. Those individuals who had occupation in sales, agriculture, service sector, skilled and unskilled manual workers were 1.6, 1.3, 2.4, 1.7 and 2.3 times more likely to chew khat, respectively, as compared to those who have no occupation. Females were 77% less likely to chew khat as compared to males. Formerly married and those experienced in child death had 1.4 and 1.2 times higher odds to chew khat as compared with those never married and never

  18. Prevalence and determinants of khat (Catha edulis chewing among high school students in eastern Ethiopia: a cross-sectional study.

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    Ayalu A Reda

    Full Text Available BACKGROUND: Use of psychoactive drugs such as khat leaves (Catha edulis alter moods and emotional state and lead to adverse effects on the health and social life of users. Ethiopia is a major producer and exporter of khat in east Africa and the majority of the khat comes from the eastern part of the country, however, no studies have been conducted to investigate the habit in this area. This study was conducted to assess the prevalence and predictors of khat chewing among high school students in Harar, eastern Ethiopia. METHODOLOGY: The study was conducted among 1,890 secondary school students in Harar town in April 2010. A structured self-administered questionnaire was used for data collection. Descriptive statistics and logistic regression were performed to examine the prevalence and predictors of khat chewing. RESULT: The overall prevalence of khat chewing among the sample was 24.2% (95% CI 22.2%-26.2%. About 28.5% of females and 71.5% of males had chewed khat. Older age (OR 1.31; 95% CI 1.16-1.49, male gender (OR 2.10; 95% CI 1.50-2.93, Muslim religion (OR 1.88; 95% CI 1.17-3.04, having friends who chewed khat (OR 7.93; 95% CI 5.40-11.64, and availability of someone with a similar habit in the family (OR 1.50; 95% CI 1.07-2.11 were found to be independent predictors of chewing. CONCLUSION: A significant proportion of students chew khat. The use of khat is significantly associated with age, gender, Muslim religion, peer influence and habit of family and other relatives among students. Measures such as educational campaigns need to be instituted to create awareness among school adolescents and their parents in order to reduce the prevalence of the habit and its adverse social and health consequences.

  19. Prevalence and determinants of khat (Catha edulis) chewing among high school students in eastern Ethiopia: a cross-sectional study.

    Science.gov (United States)

    Reda, Ayalu A; Moges, Asmamaw; Biadgilign, Sibhatu; Wondmagegn, Berhanu Y

    2012-01-01

    Use of psychoactive drugs such as khat leaves (Catha edulis) alter moods and emotional state and lead to adverse effects on the health and social life of users. Ethiopia is a major producer and exporter of khat in east Africa and the majority of the khat comes from the eastern part of the country, however, no studies have been conducted to investigate the habit in this area. This study was conducted to assess the prevalence and predictors of khat chewing among high school students in Harar, eastern Ethiopia. The study was conducted among 1,890 secondary school students in Harar town in April 2010. A structured self-administered questionnaire was used for data collection. Descriptive statistics and logistic regression were performed to examine the prevalence and predictors of khat chewing. The overall prevalence of khat chewing among the sample was 24.2% (95% CI 22.2%-26.2%). About 28.5% of females and 71.5% of males had chewed khat. Older age (OR 1.31; 95% CI 1.16-1.49), male gender (OR 2.10; 95% CI 1.50-2.93), Muslim religion (OR 1.88; 95% CI 1.17-3.04), having friends who chewed khat (OR 7.93; 95% CI 5.40-11.64), and availability of someone with a similar habit in the family (OR 1.50; 95% CI 1.07-2.11) were found to be independent predictors of chewing. A significant proportion of students chew khat. The use of khat is significantly associated with age, gender, Muslim religion, peer influence and habit of family and other relatives among students. Measures such as educational campaigns need to be instituted to create awareness among school adolescents and their parents in order to reduce the prevalence of the habit and its adverse social and health consequences.

  20. Determinants of alcohol use and khat chewing among Hawassa University students, Ethiopia: a cross sectional study.

    Science.gov (United States)

    Kassa, Andargachew; Wakgari, Negash; Taddesse, Fiker

    2016-09-01

    Students' alcohol and khat use have been associated with various health related problems. However, its magnitude and associated factors among Ethiopian students are not yet well documented. The study aimed to assess the prevalence of alcohol use, khat chewing and its associated factors among Hawassa University students. A cross-sectional study was conducted from June to July 2011. Multistage stratified sampling technique was employed to select 590 students. Self administered questionnaires were used to collect data. Data was entered and analysed by SPSS version 20.0. Logistic regression analyses were used to identify the association of different variables. The current prevalence of student's alcohol and khat use were 29.5% (95% CI: 25.8-33.3) and 16.3% (95% CI: 13.7-20.0) respectively. Being male (AOR 1.8; 95% CI 1.1-3.0) and living alone (AOR 20.1; 95% CI 2.5-166.7) had a higher odds of alcohol use. Similarly, family substance use history (AOR 4.8; 95% CI 2.5-9.3) and peer influence (AOR 4.6; 95% CI 2.3-9.0) had also higher odds of khat use. The proportion of student's khat chewing and alcohol use was significant. Hence, higher education in collaboration with other stakeholders should work on convincing students about the ill effects of these substances.

  1. Ischemic Cardiomyopathy and Cerebral Infarction in a Young Patient Associated with Khat Chewing

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    T. J. Meulman

    2015-01-01

    Full Text Available Khat is a stimulating agent used by many people in the Horn of Africa and the Arabian peninsula. Khat chewing is a known cardiovascular risk factor and is thought to cause vasoconstriction, systemic hypertension, and thrombogenicity. A 33-year-old Somalian man initially presented with loss of neurological function of the left arm, hazy vision, and headache. He smokes tobacco and chews two bundles of khat a week for more than 10 years. His ECG on admission showed a Q wave in V1 and V2 and 2 mm ST-elevations in V1, V2, and V3 and a terminal negative T wave in I, aVL, V2, V3, and V4, consistent with a recent, evolving anterior infarction. A noncontrast enhanced CT of the brain showed ischemia in the right middle cerebral artery vascular territory. An MRI showed recent ischemia in the vascular territory of the posterior division of the right middle cerebral artery. Coronary angiography showed a 70% stenosis with haziness of the proximal left anterior descending artery. Diagnostic tests and imaging are consistent with recent myocardial infarction in the LAD vascular territory because of coronary spasm and cerebral infarction in the middle cerebral artery vascular territory probably related to khat chewing.

  2. Determinants of alcohol use and khat chewing among Hawassa ...

    African Journals Online (AJOL)

    Similarly, family substance use history (AOR 4.8; 95% CI 2.5-9.3) and peer influence (AOR 4.6; ... been associated with risky sexual behavior, predisposi- ... control confounding variables. ..... which might be helpful in buying alcohol and khat.

  3. Determinants of alcohol use and khat chewing among Hawassa ...

    African Journals Online (AJOL)

    School of Nursing and Midwifery, College of Medicine and Health Sciences, Hawassa University, ... Results: The current prevalence of student's alcohol and khat use were 29.5% (95% CI: 25.8-33.3) and 16.3% (95% CI: 13.7- .... Elementary to Grade 12 228 (38.9%) ..... tion among youths visiting HIV testing and counseling.

  4. Khat Chewing and Mental Distress: A Community Based Study, in ...

    African Journals Online (AJOL)

    BACKGROUND: Khat (Catha edulis) contains a psychoactive substance, cathinone, which produces central nervous system stimulation analogous to amphetamine. It is believed that ... Using cut-off point 7 out of 20 on the Self Reporting Questionnaire-20, 25.8% of the study population was found to have mental distress.

  5. Khat Chewing among Students of Higher Education in Jazan Region, Saudi Arabia: Prevalence, Pattern, and Related Factors

    Directory of Open Access Journals (Sweden)

    Rashad Mohammed Alsanosy

    2013-01-01

    Full Text Available Objectives. (1 To estimate the prevalence and behavioral patterns of Khat chewing and (2 to investigate factors that influenced the pattern of Khat use among undergraduate students in different higher education institutions in Jazan region, Saudi Arabia. Materials and Methods. A cross-sectional study using a pretested structured self-administered quantitative questionnaire was used to collect data. SPSS version 17 software program was used for data analysis. Results. The overall current Khat chewing prevalence among higher education students was found to be 23.1%, significantly higher among males at 38.5% than among females at 2.1% . Lifetime Khat chewer students were 24.8% for males at 40.5%, significantly higher compared with females at 3.7% . Univariate analysis revealed that the gender of student, smoking status of student, a friend’s smoking, and Khat chewing were associated with a significant high risk of Khat chewing (   for all. Conclusions. The use of Khat trend is increasing among higher education students in Jazan region. A multilevel, value based, comprehensive, and strategic long-term intervention plan is needed. The comprehensive plan may include social interventions geared by creating recreations alternatives and opportunities for youth and a critical review for current authorities’ interventions and services.

  6. Khat Chewing Practice and Associated Factors among Adults in Ethiopia: Further Analysis Using the 2011 Demographic and Health Survey.

    Directory of Open Access Journals (Sweden)

    Demewoz Haile

    Full Text Available Khat chewing has become a highly prevalent practice and a growing public health concern in Ethiopia. Although there have been many small scale studies, very limited national information has been available in the general population. This study aimed to identify factors associated with khat chewing practice among Ethiopian adults.The study used the 2011 Ethiopian demographic and health survey data. The survey was cross-sectional by design and used a multistage cluster sampling procedure. Bivariate and multivariable logistic regression models with adjusted odds ratio (AOR and their 95% confidence intervals (CI were used to quantify the predictors.The overall khat chewing prevalence was 15.3% (95% CI: 14.90-15.71. Regional variation was observed with the highest in Harari [(53.2% (95% CI: 43.04-63.28] and lowest in Tigray regional state [(1.1% (95% CI: 0.72-1.66]. Multivariable analysis showed that Islam followers were 23.8 times more likely to chew khat as compared to Orthodox followers. Being a resident in Oromiya, South Nation, Nationalities and People (SNNP, Gambella, Harari and Dire Dawa regions had 1.9, 1.6, 3.1, 5.2 and 3.5 times higher odds of chewing khat as compared to Addis Ababa residents, respectively. Adults in the age group 45-49 years were 3.6 times more likely to chew khat as compared to 15-19 years. The middle and richest wealth quintiles were 1.3 and 1.5 times more likely to chew khat, respectively, as compared to the poorest category. Rural residents had 1.3 odds of chewing khat than urban residents. Those individuals who had occupation in sales, agriculture, service sector, skilled and unskilled manual workers were 1.6, 1.3, 2.4, 1.7 and 2.3 times more likely to chew khat, respectively, as compared to those who have no occupation. Females were 77% less likely to chew khat as compared to males. Formerly married and those experienced in child death had 1.4 and 1.2 times higher odds to chew khat as compared with those never married

  7. Khat Chewing among Students of Higher Education in Jazan Region, Saudi Arabia: Prevalence, Pattern, and Related Factors

    OpenAIRE

    Alsanosy, Rashad Mohammed; Mahfouz, Mohamed Salih; Gaffar, Abdelrahim Mutwakel

    2013-01-01

    Objectives. (1) To estimate the prevalence and behavioral patterns of Khat chewing and (2) to investigate factors that influenced the pattern of Khat use among undergraduate students in different higher education institutions in Jazan region, Saudi Arabia. Materials and Methods. A cross-sectional study using a pretested structured self-administered quantitative questionnaire was used to collect data. SPSS version 17 software program was used for data analysis. Results. The overall current Kha...

  8. Khat chewing among students of higher education in Jazan region, Saudi Arabia: prevalence, pattern, and related factors.

    Science.gov (United States)

    Alsanosy, Rashad Mohammed; Mahfouz, Mohamed Salih; Gaffar, Abdelrahim Mutwakel

    2013-01-01

    (1) To estimate the prevalence and behavioral patterns of Khat chewing and (2) to investigate factors that influenced the pattern of Khat use among undergraduate students in different higher education institutions in Jazan region, Saudi Arabia. A cross-sectional study using a pretested structured self-administered quantitative questionnaire was used to collect data. SPSS version 17 software program was used for data analysis. The overall current Khat chewing prevalence among higher education students was found to be 23.1%, significantly higher among males at 38.5% than among females at 2.1% (P higher compared with females at 3.7% (P higher education students in Jazan region. A multilevel, value based, comprehensive, and strategic long-term intervention plan is needed. The comprehensive plan may include social interventions geared by creating recreations alternatives and opportunities for youth and a critical review for current authorities' interventions and services.

  9. Association between khat chewing and intestinal parasitic infestations: a community based, cross-sectional study done in Jimma Town, Southwest Ethiopia.

    Science.gov (United States)

    Mossie, Andualem; Kebedez, Seleshi; Gobena, Teshome

    2013-07-01

    Khat (Catha edulis Forsk), is the psychostimulant herb cultivated in East Africa. Khat chewing could have health damaging effect. The aim of the present study was to determine the association between khat chewing and intestinal parasitic infestation. A cross sectional study was conducted in Jimma Town in July 2010. Structured questionnaire was administered to 991 individuals selected by a systematic sampling method. Stool samples were collected for the diagnosis of intestinal parasitic infestation. Data analysis was done using SPSS Version 16.0 for Windows. Among 991 respondents, 638 (64.4%) were females, 502 (50.7%) were Oromos, 486 (49%) were Orthodox and 475 (47.9%) of them were in the age group of 18-24 years old. The current prevalence of khat chewing was found to be 52.7%. The prevalence of single to multiple parasitic infestations was 33.4%. Negative association (p = 0.000) was recorded between the habit of khat chewing and intestinal parasitosis. Non-chewers were more affected than chewers. Higher proportion of non chewers was infested with parasites than chewers, suggesting that khat chewing might have a protective role against parasitic infestation. Further investigation on the effect of khat extract in in vitro and in vivo is recommended to disclose detail mechanisms.

  10. Prevalence of cigarette smoking and khat chewing among Aden university medical students and their relationship to BP and body mass index

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    Laswar Al Khader

    2009-01-01

    Full Text Available To evaluate the smoking and khat chewing habits in male Aden University medical students and correlate them with blood pressure (BP, body mass index (BMI, and year of training, we randomly selected 100 students of different levels of training and measured their BP, height, and weight, and evaluated their cigarette smoking and khat chewing habits. The mean age of the whole group was 31.8 years. The mean BMI was 23.24 with a range from 22.6 in the in first year medical students to 24.7 (4.4 in 5 th year medical students (P= 0.127. The mean SBP, DBP, and MBP were 120.35, 70.47 and 87.1 mmHg, respectively, and did not change over the years of training. Preva-lence of smoking increased from 20% to 40% and khat chewing from 35% to 90% over the 5 years of training (P= 0.0003. There was a tendency for positive correlation between age and weight, BMI and frequency of khat chewing, and BMI and MBP. We found high prevalence of smoking and khat chewing among the medical students at Aden University and their prevalence increases with student seniority with no significant changes in BMI, SBP, DBP or MBP. There was a weak positive correlation between BMI with SBP, MBP and frequency of Khat chewing.

  11. Prevalence, Reasons, and Perceived Effects of Khat Chewing Among Students of a College in Gondar Town, Northwestern Ethiopia: A Cross-Sectional Study.

    Science.gov (United States)

    Teni, F S; Surur, A S; Hailemariam, A; Aye, A; Mitiku, G; Gurmu, A E; Tessema, B

    2015-01-01

    The estimate of the number of people chewing Khat globally ranges from 5 to 10 million people. Its use may result in a variety of effects due to the different compounds in it with effects on the gastro-intestinal system and nervous system being the principal ones. To assess the prevalence, factors, and effects of Khat chewing among students of a college in Gondar town, northwestern Ethiopia. An institution-based cross-sectional study was conducted from 15(th) to 20(th) of April 2009 on a total sample of 424 students who were selected using stratified random sampling technique. Data were collected by three of the principal investigators using a structured pretested data collection instrument and analyzed by Epi Info version 3.5.2. The lifetime and current prevalence of Khat chewing among the respondents were 42% (168/400) and 32.5% (130/400), respectively. Sex (P sleep disturbance, 82.3% (107/130) loss of appetite, and 80.8% (105/130) constipation. The prevalence of Khat chewing was fairly high among the students and the majority among them used other substances together with Khat. Spending of a significant amount of money and facing health problems were reported to be consequences of the habit. The college should take steps to make students aware of the ills of Khat chewing and associated habits.

  12. Khat Use: History and Heart Failure

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    Ayman El-Menyar

    2015-03-01

    Full Text Available Recent reports suggest that 20 million people worldwide are regularly using khat as a stimulant, even though the habit of chewing khat is known to cause serious health issues. Historical evidence suggests khat use has existed since the 13th century in Ethiopia and the southwestern Arabian regions even before the cultivation and use of coffee. In the past three decades, its availability and use spread all over the world including the United States and Europe. Most of the consumers in the Western world are immigrant groups from Eastern Africa or the Middle East. The global transport and availability of khat has been enhanced by the development of synthetic forms of its active component. The World Health Organization considers khat a drug of abuse since it causes a range of health problems. However, it remains lawful in some countries. Khat use has long been a part of Yemeni culture and is used in virtually every social occasion. The main component of khat is cathinone, which is structurally and functionally similar to amphetamine and cocaine. Several studies have demonstrated that khat chewing has unfavorable cardiovascular effects. The effect on the myocardium could be explained by its effect on the heart rate, blood pressure, its vasomotor effect on the coronary vessels, and its amphetamine–like effects. However, its direct effect on the myocardium needs further elaboration. To date, there are few articles that contribute death among khat chewers to khat-induced heart failure. Further studies are needed to address the risk factors in khat chewers that may explain khat-induced cardiotoxicity, cardiomyopathy, and heart failure.

  13. Comparison of Smoking and Khat Chewing Habits between Medical and Non-Medical Female Students at UST, Sana'a, Yemen.

    Science.gov (United States)

    Kubas, Mohammed Abdullah; Wadi, Majed

    2015-01-01

    Smoking is a worldwide problem that kills millions of people. Women smoke much lower than males but the numbers of smoker women are growing up. The objectives of this study were to assess the prevalence of smoking and khat chewing in medical and non-medical female students at University of Science and Technology (UST), Sana'a, Yemen. We used self-administrated questionnaire to collect cross-sectional data from a randomly selected sample of medical and non-medical female students of UST in 2012-2013. Overall, 480 students completed and returned the questionnaire, of them medical students represented 50% of them. The prevalence of smoking was significantly low among female medical students (P=0.045), however, not significantly difference was found between medical and non-medical female students in khat chewing habits (P=0.083). Non-smoker medical female students who tried smoking (45.6%) were significantly lower than non-medical students (54.4%), and curiosity was the main reason for trying smoking. Water pipe was the most common type of smoking among smoker students (78.6%). Out of 26 female students who smoke and chew khat, 18 students reported that they smoke more while they chew khat. Our study highlights the need for increased health education, awareness, and knowledge of the risks of smoking and particularly khat chewing to reduce these habits among female university students especially in non-medical female students.

  14. Is khat-chewing associated with HIV risk behaviour? A community ...

    African Journals Online (AJOL)

    We suggest that HIV/AIDS programmes in certain regions should address the habitual use of khat and other substances of potential abuse as part of their intervention efforts to curb the epidemic. Keywords: alcohol, amphetamine, cathinone, drug use, khat, psychotropic drugs. African Journal of AIDS Research 2006, 5(1): ...

  15. Pesticide Application and Khat Chewing as Predictors of the Neurological Health Outcomes among Pesticide Applicators in a Vector Control Unit, Saudi Arabia

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    Ahmed A Ismail

    2018-01-01

    Full Text Available Background: Pesticide applicators are at risk of developing neurological symptoms and neurobehavioral deficits. This risk may increase if the applicator chews stimulant plants like khat. Objective: To examine the sociodemographic and exposure determinants of neurological symptoms presentation, neurobehavioral performance, and cholinesterase activity among pesticide applicators in a vector control unit, Saudi Arabia. Methods: In a cross-sectional study, 30 pesticide applicators and 32 non-applicators from a vector control unit in Jazan region, Saudi Arabia, were studied. The study participants completed an exposure and medical questionnaire, and a neurobehavioral test battery. Their blood samples were also tested for the measurement of butyryl cholinesterase (BChE. Results: The mean blood BChE level was no significantly different between the applicators and non-applicators. Working in pesticide application and chewing khat were significant predictors of the neurological symptoms presentation and neurobehavioral deficits among the study participants. Each factor was associated with about 40% of the symptoms included in the questionnaire. Exposure to pyrethroids was significantly associated with a decrement in symbol digit test latency, tapping (TAP non-preferred hand, and TAP alternating hands measures, representing the executive and motor speed/coordination functions. Khat chewing was associated with TAP preferred and non-preferred hands and serial digit learning measures, representing the memory and motor speed/coordination functions. Conclusions: It seems that being exposed to pyrethroids and chewing khat are associated with neurological and neurobehavioral drawbacks among pesticide applicators.

  16. Khat chewing habit as a possible risk behaviour for HIV infection: a ...

    African Journals Online (AJOL)

    Background: The use/abuse of psychoactive drugs such as khat leaves (Catha edulis) are believed to alter one's moods or emotional state either through the sustained release or inhibition of neurotransmitters, thereby enhancing or dampening the response of the individual. Most people whose thinking are warped by ...

  17. Exposure to DDT and its metabolites from khat (Catha edulis) chewing: Consumers risk assessment from southwestern Ethiopia.

    Science.gov (United States)

    Mekonen, Seblework; Ambelu, Argaw; Negassa, Belay; Spanoghe, Pieter

    2017-07-01

    Khat (Catha edulis) is one of the most consumed plant in the horn of African countries. However, it is a stimulant plant that has several side effects on the health of consumers. On top of that, the khat leaves used for human consumption are often contain contaminants such as pesticide residues. The present study aims to investigate the level of DDT residue and its metabolites (p'p-DDE, p'p-DDD, o'p-DDT and p'p-DDT) in khat samples and to undertake exposure assessment to consumers. The khat samples were collected from local markets in southwestern Ethiopia. Consumption survey was undertaken using 24 h recall method for both male and female khat consumers. The finding showed that 80% of the khat samples contained DDT and its metabolites. Some of the residues were above the maximum residue limit (MRL) set by Food and Agricultural Organization (FAO). The concentration of p'p-DDE and p'p-DDT in khat were in the range of 0.033-0.113 and 0.010-0.026 mg/kg, respectively. High concentration of the metabolite (p'p-DDE) compared to the parent compound (p'p-DDT) revealed the historical use of DDT in the study area. Probabilistic exposure analysis indicated that the mean and 97.5 percentile (P97.5), of the estimated daily intake of total DDT were 0.002 and 0.006 mg/kg bw/day, respectively. The study concluded that khat consumers are exposed to the stimulant effect of the plant as well as DDT and its metabolites in Jimma zone. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Khat-induced hypnagogic hallucinations.

    Science.gov (United States)

    Granek, M; Shalev, A; Weingarten, A M

    1988-10-01

    Khat is a plant whose leaves are chewed for their stimulating effect. This effect is attributed to cathinone, an alkaloid identical to dextroamphetamine. Khat chewing is widespread among eastern African and Yemenite populations and is believed to be innocuous. Our experience shows, however, that a substantial number of chronic khat chewers experience persistent hypnagogic hallucinations - a symptom that has not yet been described. Three vignettes illustrates this phenomena, which often interferes with psychiatric diagnosis. Different explanatory models are discussed, among them chronic suppression of REM sleep.

  19. Khat and stroke

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    Sanjay V Kulkarni

    2012-01-01

    Full Text Available Khat chewing, though a tradition followed majorly in African countries, has of late spread widely across the globe due to faster transport systems and advanced preservation techniques. Many complications such as psychosis, arterial hypertension, angina pectoris, and myocardial infarction have been reported in connection to khat abuse. We present a case of a young man who presented with acute onset left-sided weakness. He was a known khat addict for over three decades. A diagnosis of left hemiplegia due to right middle cerebral artery infarction was established. Detailed evaluation revealed no significant underlying cause for stroke. Since the main central nervous system effects of khat are comparable with those of amphetamines and there are established reports of stroke in amphetamine abuse, the former was assumed to be the etiological factor. The patient was discontinued from taking khat and was managed conservatively. The subject showed significant recovery with no further complications or similar episodes during follow-up. To the best of our knowledge, this is the second case of stroke associated with khat. Since the management is essentially conservative, a vigilant history eliciting of khat abuse in prevalent countries would cut down unnecessary healthcare costs.

  20. Prevalence of Khat, Cigarette and Alcohol Use Among Students of ...

    African Journals Online (AJOL)

    Prevalence of Khat, Cigarette and Alcohol Use Among Students of Technology and Pharmacy, Addis Ababa University. E Eshetu, T Gedif ... devise mechanisms to develop the awareness of students on the health and social impacts of khat chewing, cigarette smoking and alcohol drinking. Keywords: khat, cigarette, alcohol, ...

  1. Use and perception of the psychostimulant, khat ( catha edulis ...

    African Journals Online (AJOL)

    Subjects: Three categories of respondents prone to khat chewing habit were selected; One hundred and thirty students, thirty five law enforcement officials and sixteen transporters. Main outcome ... As at the time of this study, 37(20.4%) still chewed khat. ... This calls for attention considering the public health implications.

  2. Khat use and appetite: an overview and comparison of amphetamine, khat and cathinone.

    Science.gov (United States)

    Lemieux, Andrine M; Li, Bingshuo; al'Absi, Mustafa

    2015-02-03

    To understand the role of khat (Catha edulis) use on the aberrations in appetite and weight which are common comorbidities for khat and other amphetamine users. We provide a comprehensive overview and conceptual summary of the historical cultural use of khat as a natural stimulant and describe the similarities and differences between cathinone (the main psychoactive constituent of khat) and amphetamine highlighting the limited literature on the neurophysiology of appetite and subsequent weight effects of khat. Animal and some human studies indicate that khat produces appetite suppression, although little is known about mechanisms of this effect. Both direct and indirect effects of khat stem from multiple factors including behavioral, chemical and neurophysiological effects on appetite and metabolism. Classic and newly identified appetite hormones have not been explored sufficiently in the study of appetite and khat use. Unique methodological challenges and opportunities are encountered when examining effects of khat and cathinone including khat-specific medical comorbidities, unique route of administration, differential patterns of behavioral effects relative to amphetamines and the nascent state of our understanding of the neurobiology of this drug. A considerable amount of work remains in the study of the appetite effects of khat chewing and outline a program of research that could inform our understanding of this natural amphetamine׳s appetite effects and help prepare health care workers for the unique health effects of this drug. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Khat use and appetite: An overview and comparison of amphetamine, khat and cathinone

    Science.gov (United States)

    Lemieux, Andrine M.; Li, Bingshuo; al’Absi, Mustafa

    2014-01-01

    Ethnopharmacological relevance To understand the role of khat (Catha edulis) use on the aberrations in appetite and weight which are common comorbidities for khat and other amphetamine users. Materials and methods We provide a comprehensive overview and conceptual summary of the historical cultural use of khat as a natural stimulant and describe the similarities and differences between cathinone (the main psychoactive constituent of khat) and amphetamine highlighting the limited literature on the neurophysiology of appetite and subsequent weight effects of khat. Results Animal and some human studies indicate that khat produces appetite suppression, although little is known about mechanisms of this effect. Both direct and indirect effects of khat stem from multiple factors including behavioral, chemical and neurophysiological effects on appetite and metabolism. Classic and newly identified appetite hormones have not been explored sufficiently in the study of appetite and khat use. Unique methodological challenges and opportunities are encountered when examining effects of khat and cathinone including khat-specific medical comorbidities, unique route of administration, differential patterns of behavioral effects relative to amphetamines and the nascent state of our understanding of the neurobiology of this drug. Conclusion A considerable amount of work remains in the study of the appetite effects of khat chewing and outline a program of research that could inform our understanding of this natural amphetamine’s appetite effects and help prepare health care workers for the unique health effects of this drug. PMID:25435289

  4. East African discourses on khat and sex.

    Science.gov (United States)

    Beckerleg, Susan

    2010-12-01

    The study aims to review and analyse the varied East African discourses on the effects of khat use on libido, fertility, transmission of HIV, prostitution and rape. The data were gathered between 2004 and 2009 in Kenya and Uganda. Between 2004 and 2005 across Kenya and Uganda a broad survey approach was adopted, involving identification of and travel to production areas, interviews with producers and consumers in rural and urban settings. In addition, a survey of 300 Ugandan consumers was carried out in late 2004. Between 2007 and 2009, an in-depth study of khat production, trade and consumption was conducted in Uganda. This study also employed a mixture of methods, including key informant interviews participant-observation and a questionnaire survey administered to 210 khat consumers. Khat is associated, by consumers and its detractors alike, with changes in libido and sexual performance. Although there is no evidence to support their claims, detractors of khat use argue that khat causes sexual violence, causes women to enter sex work, and that chewing causes the spread of sexually transmitted diseases, including the HIV virus. In East Africa the discourse on khat and sex has led to consumption of the substances being associated by many people with uncontrolled sexual behaviour. There is no evidence that khat use fuels promiscuity, commercial sex, sexually transmitted diseases or rape. The current discourse on khat and sex touches on all these topics. Local religious and political leaders invoke khat use as a cause of what they argue is a breakdown of morals and social order. In Kenya and Uganda it is women khat consumers who are seen as sexually uncontrolled. In Uganda, the argument is extended even to men: with male khat chewers labelled as prone to commit rape. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  5. Determinants of Alcohol, Khat, and Bhang Use in Rural Kenya ...

    African Journals Online (AJOL)

    The participants completed a survey measuring possible psychosocial determinants of alcohol, khat and bhang (i.e., marijuana) use patterns. The sample evidenced high levels of substance use particularly involving the locally available substances (i.e., bottled beer, local brews, chewing khat, smoking bhang). Males in ...

  6. Subchronic Crude Khat ( Catha edulis F.) Extract Administration ...

    African Journals Online (AJOL)

    People chew khat (Catha edulis F.), believing that it improves memory, ... Morphometric analysis revealed a significant reduction in weight of brain as well as ... properties of the dentate granule cells, including volume of the granular layer of ...

  7. Health and socio-economic hazards associated with khat consumption

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    Hussein M. A. Ageely

    2008-01-01

    The purpose of this review is to describe briefly the adverse consequences of habitual chewing of Khat on health, and help educate the general public. The study is based on literature review that includes internet search and journals.

  8. Salivary caries parameters: Comparative study among Yemeni khat chewers and nonchewers

    OpenAIRE

    Khaled Rashad Al-Alimi; Abdul Aziz Abdul Razak; Roslan Saub

    2014-01-01

    Background/purpose: Millions of people in Yemen and East African countries chew khat for more than 5 hours daily for its amphetamine-like effects. Previous studies have associated khat chewing with salivary glands enlargement, inflammation, and xerostomia. However, no information is available on the possible effects of this habit on salivary parameters. This comparative study aims to evaluate salivary parameters, such as salivary flow rate, pH, and viscosity among Yemeni khat chewers and nonc...

  9. Khat Dependency and Psychophysical Symptoms among Chewers in Jazan Region, Kingdom of Saudi Arabia

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    Maged El-Setouhy

    2016-01-01

    Full Text Available Background. Khat chewing is highly prevalent in Africa, Yemen and Jazan region, southwest of Saudi Arabia. Most of Jazani Khat chewers consider khat session as a social activity and do not consider khat dependency. The aim of this study was to explore khat dependency and its relationship with the psychophysical symptoms among chewers. Methods. Cross-sectional study on seventy Saudi male khat chewers living in Jazan area. Psychological dependence to khat chewing was evaluated using the Severity of Dependency Scale (SDS. The participants filled in a self-administrated assisted structured questionnaire designed to collect data about their medical history, neurological symptoms, and their chewing behavior. Results. Half (52.2% of khat chewers showed psychological dependency. Those having longer khat sessions (≥6 hours were more liable for dependency. Physical and psychological symptoms were more prevalent among khat dependent chewers. Conclusions. khat has a psychological dependence effect that can be measured by the SDS, even in low doses and with irregular use. SDS scale is a useful tool to expect the burden of either physical or psychological symptoms on khat chewers.

  10. Evaluation of the effect of various drying techniques on the composition of the psychoactive phenylpropylamino alkaloids of khat (Catha edulis Forsk chewing leaves

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    S. Chigome

    2013-09-01

    Full Text Available The study demonstrated that by freezing or drying under different conditions, cathinone could be detected in the khat (Catha edulis Forsk samples that have been harvested for more than four months. Freeze drying or freezing in the refrigerator (-20 oC yielded more than 73% of cathinone. Air drying, sun drying or oven drying at 60 oC resulted in a cathinone composition of 57%, 42% and 36%, respectively. The study confirmed that, freshly harvested tender leaves of khat contained exclusively of cathinone but upon sun drying, part of it decomposes to cathine and norephedrine leaving cathinone as a major component. Thus it is wrong to assume that sun drying the leaves can result complete conversion of cathinone to cathine and norephedrine. Furthermore, the results of the study confirmed that it was possible to preserve khat samples for longer periods after freeze drying or deep freezing without significant loss of cathinone.DOI: http://dx.doi.org/10.4314/bcse.v27i3.3

  11. Khat (Catha edulis: The herb with officio-legal, socio-cultural and economic uncertainty

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    Sikiru Lamina

    2010-04-01

    Full Text Available Khat (Catha edulis is a plant of uncertain and highly controversial status grown in the countries around the Red Sea and on the eastern coast of Africa. The chewing of khat leaves has a deep-rooted religious and socio-cultural tradition. Khat is considered a cash crop and its cultivation is a source of economic value to the societies and nations involved. There have, however, been reports of negative economic effects on the individuals engaging in the habit of khat chewing.

    The increasing use of khat worldwide, along with the negative international attention that this has garnered, has led to the present status of uncertainty of the once indigenous practice of khat chewing. Scientists, mostly western Europeans, have tended to focus on problems related to khat with little attention to the positive role of khat chewing in society and the world at large. In addition, no report has directly associated khat with any organised crime, violence or antisocial activity, particularly in countries where khat is legalised.

    This paper reviewed the various areas of uncertainty and controversy relating to khat. Based on the findings of the review, further qualitative and quantitative research is required and a positive international approach to khat use at economic, religious and socio-cultural levels is advocated.

  12. Khat (Catha edulis Forsk. Dependence Potential and Pattern of Use in Saudi Arabia

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    Siddig Ibrahim Abdelwahab

    2015-01-01

    Full Text Available Background. Catha edulis Forsk. (Khat is used for its psychoactive effects among people in Africa and the Arabian Peninsula, although its utilization is illegal in some countries such as Saudi Arabia. This study examined the pattern of Khat use and assessed the applicability of the Drug Abuse Screening Test-10 (DAST-10 to measure Khat dependence. Methods. A pretested questionnaire was used to gather data from 603 respondents. Variables included demographic characteristics, pattern of use, reasons for Khat chewing, and DAST-10. Stepwise-logistic regression was used to explore predictors of Khat dependence. Results. The majority of the respondents were married, had a secondary school level of education, were employed, were younger than 35 years old, and were living in rural areas. Many chewers gave more than one reason for using Khat. It was mainly used to increase mental capacity, physical strength, and social entertainment, as well as enhance cheerfulness and orgasms. Statistical modeling of Khat dependence suggested that the most significant predictors were residence (OR = 1.67, P<0.02, frequency of Khat chewing (OR = 4.8, P<0.01, age of starting Khat chewing (OR = 1.15, P<0.01, and time of Khat effect (OR = 1.15, P<0.04. Conclusion. Our study provides important information on the pattern of Khat use and its potential to cause dependence.

  13. Use and perception of the psychostimulant, khat (catha edulis) among three occupational groups in south western Uganda.

    Science.gov (United States)

    Ihunwo, A O; Kayanja, F I B; Amadi-Ihunwo, U B

    2004-09-01

    To examine the use of and perception of the psychostimulant, khat (catha edulis) in three towns in south-western Uganda. Cross-sectional survey. Mbarara, Kabale and Fort Portal. Three categories of respondents prone to khat chewing habit were selected; One hundred and thirty students, thirty five law enforcement officials and sixteen transporters. Khat chewers existed within the sampled population. The relationship between tobacco smoking, drinking alcoholic beverages and the khat chewing habit was established. Out of 181 respondents, 164(90.6%) had heard of khat, 126(69.6%) had seen it and 57(31.5%) had chewed khat before. As at the time of this study, 37(20.4%) still chewed khat. Within the three categories of subjects, the use of khat was highest among law enforcement officials (97.1%), followed by transporters (68.8%) and students (9.2%). The majority of khat chewers were in the age range of 16-25 years. There was a clear correlation between khat chewing and the use of stimulants such as alcoholic beverages and tobacco smoking. Those who smoked cigarettes were twenty-eight times more likely to chew khat (OR=28.95% CI=9.6,83.7). Euphoria, suppressed sleep and increased sexual desire were the most predominant effects experienced by khat chewers. The knowledge of khat is widespread and its consumption is on the increase among students, law enforcement officials and transporters in south-western Uganda. This calls for attention considering the public health implications.

  14. Oral Lesions Induced by Chronic Khat Use Consist Essentially of Thickened Hyperkeratinized Epithelium

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    Ochiba Mohammed Lukandu

    2015-01-01

    Full Text Available Objectives. The habit of khat chewing is prevalent in many Middle Eastern and African cultures and has been associated with various adverse conditions in humans. This study aimed to describe histological changes induced by chronic khat chewing on the buccal mucosa. Methods. Biopsies of the buccal mucosa from 14 chronic khat chewers, 20 chronic khat chewers who also smoked tobacco, and 8 nonchewers were compared for epithelial thickness, degree and type of keratinization, and connective tissue changes. Results. Tissues from khat chewers depicted abnormal keratinization of the superficial cell layer and showed increased epithelial thickness affecting all layers. Epithelial thickness in control samples was 205 ± 26 μm whereas thickness in khat chewers and khat chewers who smoked tobacco was significantly higher measuring 330 ± 35 μm and 335 ± 19 μm, respectively. Tissues from khat chewers also showed increased intracellular edema, increased melanin pigment deposits, and increased number of rete pegs most of which were thin and deep. Conclusions. These results show that oral lesions induced by chronic chewing of khat in the buccal mucosa present with white and brown discoloration due to increased epithelial thickness, increased keratinization, and melanin deposition.

  15. Khat use, PTSD and psychotic symptoms among Somali refugees in Nairobi - a pilot study

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    Marina eWidmann

    2014-06-01

    Full Text Available In East-African and Arab countries, khat leaves are traditionally chewed in social settings. They contain the amphetamine-like alkaloid cathinone. Especially among Somali refugees khat use has been associated with psychiatric symptoms. We assessed khat use patterns and psychiatric symptoms among male Somali refugees living in a disadvantaged urban settlement area in Kenya, a large group that has not yet received scientific attention. We wanted to explore consume patterns and study the associations between khat use, traumatic experiences and psychotic symptoms.Using privileged access sampling we recruited 33 healthy male khat chewers and 15 comparable non-chewers. Based on extensive preparatory work, we assessed khat use, khat dependence according to DSM-IV, traumatic experiences, Posttraumatic Stress Disorder and psychotic symptoms using standardized diagnostic instruments that had been adapted to the Somali language and culture.Hazardous use patterns like chewing for more than 24 hours without interruption were frequently reported. All khat users fulfilled the DSM-IV-criteria for dependence and eighty-five percent reported functional khat-use, i.e. that khat helps them to forget painful experiences. We found that the studied group was heavily burdened by traumatic events and posttraumatic symptoms. Khat users had experienced more traumatic events and had more often PTSD than non-users. Most khat users experience khat-related psychotic symptoms and in a quarter of them we found true psychotic symptoms. In contrast, among control group members no psychotic symptoms could be detected.We found first evidence for the existence and high prevalence of severely hazardous use patterns, comorbid psychiatric symptoms and khat use as a self-medication of trauma-consequences among male Somali refugees in urban Kenyan refugee settlements. There is a high burden by psychopathology and adequate community-based interventions urgently need to be developed.

  16. E-Cigarette as a Harm Reduction Approach among Tobacco Smoking Khat Chewers: A Promising Bullet of Multiple Gains

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    Saba Kassim

    2016-02-01

    Full Text Available Khat chewing/use, a green leaf with amphetamine-like effects is socially integrated in the Middle East and Africa. Khat chewing is often associated with tobacco smoking and occurs in closed places, such as a family home setting where the smoke-free laws cannot be implemented. Tobacco cigarette smoking among khat chewers is a significant concern, but there is also second-hand exposure to smoke at home or in places where khat users gather. Evidence suggests that e-cigarettes represent a significantly less harmful form of nicotine intake. Evaluating the effects of e-cigarettes among khat chewers could be important in understanding the impact of e-cigarettes as a harm reduction approach, with the potential to reduce the health risk associated with smoking.

  17. E-Cigarette as a Harm Reduction Approach among Tobacco Smoking Khat Chewers: A Promising Bullet of Multiple Gains.

    Science.gov (United States)

    Kassim, Saba; Farsalinos, Konstantinos E

    2016-02-19

    Khat chewing/use, a green leaf with amphetamine-like effects is socially integrated in the Middle East and Africa. Khat chewing is often associated with tobacco smoking and occurs in closed places, such as a family home setting where the smoke-free laws cannot be implemented. Tobacco cigarette smoking among khat chewers is a significant concern, but there is also second-hand exposure to smoke at home or in places where khat users gather. Evidence suggests that e-cigarettes represent a significantly less harmful form of nicotine intake. Evaluating the effects of e-cigarettes among khat chewers could be important in understanding the impact of e-cigarettes as a harm reduction approach, with the potential to reduce the health risk associated with smoking.

  18. Correlation between Resistin, Tuberculosis and Khat Addiction: A Study from South Western Province of Saudi Arabia.

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    Ayesha Alvi

    Full Text Available Tuberculosis(TB is a disease of global significance, which accounts for a death in every 15 seconds. Recent studies shows TB is rising in certain parts of the world, and Saudi Arabia is one of them. Several factor contribute in predisposing the subjects for infection including but not limited to addiction to various compounds which have immune modulation properties, such as amphetamines and Heroin etc. Khat a plant whose leaves are chewed for its euphoric effect in east Africa and Arabian Peninsula including Saudi Arabia, is considered as mildly addictive, and its principle compound, Cathinone shares structural and functional similarity with amphetamine a known immunomodulator. Tuberculosis being a disease of immune modulation has a varied spectrum of complex interplay of proinflammatory molecules, resistin is one of them. In the present study, we try to explore the trinity of khat addiction, serum resistin level and tuberculosis by correlating the serum resistin level in non khat addicted healthy subjects, khat addicted healthy subjects, and in patients, both khat addicted and non khat addicted, with active tuberculosis. We observed significantly higher resistin level among the apparently healthy khat addicted subjects as compared to non addicted healthy controls. Thereafter, when we compare the resistin levels between khat addicted and non khat addicted TB patients we did not found significant difference between the two groups. However bacillary load was observe to be significantly higher among the khat addicted TB patient as compare to non addicted one. Validation of above results in animal model revealed dose dependant increase in bacillary growth in the Wistar rats treated with khat. Taken together these results suggest the role of khat in immune modulation albeit in the limited frame of resistin level.

  19. Association of Awake Bruxism with Khat, Coffee, Tobacco, and Stress among Jazan University Students

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    Mir Faeq Ali Quadri

    2015-01-01

    Full Text Available Objective. The objective is to assess the prevalence of bruxism among the university students and to check its association with their khat chewing habit. Materials and Methods. A cross-sectional descriptive study is designed using cluster random sampling. Pretested questionnaire was administered by a trained interviewer to assess awake bruxism and the use of variables like khat, coffee, tobacco, and stress. Chi-square test at 5% significance was used for assessing the association. Logistic regression was also performed after adjusting for covariates. Results. A high response rate (95% was obtained as the distribution and collection of questionnaire was within an hour interval. 85% (63%, males; 22%, females experienced an episode of bruxism at least one time in the past six months. Regression analysis revealed an association of stress (P=0.00; OR = 5.902, 95% CI 2.614–13.325 and khat use (P=0.05; OR = 1.629, 95% CI 0.360–7.368 with bruxism. Interestingly, it is observed that the one who chew khat experienced 3.56 times (95% CI; 2.62–11.22 less pain when compared to the nonusers. Conclusion. This study is the first of its kind to assess the association of bruxism with khat chewing. High amount of stress and khat use can be considered as important risk indicators for awake bruxism.

  20. Catha edulis chewing effects on treatment of paranoid schizophrenic patients

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    Kotb El-Sayed MI

    2015-04-01

    Full Text Available Mohamed-I Kotb El-Sayed, Hatem-K Amin Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Helwan University, Ain Helwan, Helwan, Cairo, Egypt Background: The current study’s aim is to evaluate the possible interaction effects of khat chewing on treatment of paranoid schizophrenic patients.Patients and methods: In the study group, 42 male subjects suffered from paranoid schizophrenia and were classified according to their khat chewing habits into two subgroups: either khat-chewer subgroup (SKc; n=21; r=11, h=10 or non-khat-chewer subgroup (SNKc; n=21, r=11, h=10. Each subgroup was further subdivided according to type of treatment into r (risperidone and h (haloperidol. Healthy male subjects (37 were subdivided into healthy khat-chewer as positive controls (HKc, n=17 and healthy non-khat-chewer as negative controls (HNKc, n=20. Plasma dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC, homovanillic acid, 5-hydroxytryptamine (serotonin, 5-hydroxyindoleacetic acid, epinephrine, and norepinephrine were estimated.Results: ANOVA and post hoc analysis showed that dopamine was illustrating significant elevation in all khat chewing groups. DOPAC was illustrating significant decrease in all khat chewing groups with an interesting outcome showing significant increase in DOPAC in SNKcr group due to risperidone effect. Homovanillic acid, serotonin, hydroxyindoleacetic acid, and norepinephrine were illustrating significant elevations in all khat chewing groups. Epinephrine was illustrating significant elevation in all chewers than non-chewers groups. Unexpected significant decrease in epinephrine in the SNKcr group indicated that risperidone drug is decreasing epinephrine through indirect mechanism involving calcium.Conclusion: Khat chewing in schizophrenic patients is contraindicated because it aggravates the disease symptoms, attenuates all used treatment medications, and deteriorates all biochemical markers of the patients. Keywords

  1. Legal harvest and illegal trade: Trends, challenges, and options in khat production in Ethiopia.

    Science.gov (United States)

    Cochrane, Logan; O'Regan, Davin

    2016-04-01

    The production of khat in Ethiopia has boomed over the last two decades, making the country the world's leading source. Khat is now one of Ethiopia's largest crops by area of cultivation, the country's second largest export earner, and an essential source of income for millions of Ethiopian farmers. Consumption has also spread from the traditional khat heartlands in the eastern and southern regions of Ethiopia to most major cities. This steady growth in production and use has unfolded under negligible government support or regulation. Meanwhile, khat, which releases a stimulant when chewed, is considered an illicit drug in an increasing number of countries. Drawing on government data on khat production, trade, and seizures as well as research on the political, socioeconomic, and development effects of plant-based illicit narcotics industries, this commentary identifies possible considerations and scenarios for Ethiopia as the country begins to manage rising khat production, domestic consumption, and criminalization abroad. Deeply embedded in social and cultural practices and a major source of government and agricultural revenue, Ethiopian policymakers have few enviable choices. Criminalization abroad raises a small but not insignificant possibility that previously nonexistent linkages between khat and transnational organized crime and trafficking networks will emerge. Likewise, more stringent regulation of khat in Ethiopia could merge with lingering political cleavages and anti-government sentiments, exacerbating low-level domestic conflicts. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Is khat a social ill? Ethical argument about a stimulant among the learned Ethiopians

    NARCIS (Netherlands)

    Dessie, G.

    2013-01-01

    This study focuses on the khat phenomenon by analyzing experiences and the thinking of learned Ethiopians towards this substance using a phenomenographic method. The educated bracket of Ethiopian society is exposed to chewing during the high school and university years. A significant number of them

  3. Molecular imaging of alkaloids in khat (Catha edulis) leaves with MeV-SIMS

    Science.gov (United States)

    Jenčič, Boštjan; Jeromel, Luka; Ogrinc Potočnik, Nina; Vogel-Mikuš, Katarina; Vavpetič, Primož; Rupnik, Zdravko; Bučar, Klemen; Vencelj, Matjaž; Kelemen, Mitja; Matsuo, Jiro; Kusakari, Masakazu; Siketić, Zdravko; Al-Jalali, Muhammad A.; Shaltout, Abdallah; Pelicon, Primož

    2017-08-01

    Imaging Mass Spectroscopy (IMS) is a unique research tool providing localization and identification of a wide range of biomolecules as essential data to understand biochemical processes in living organisms. Secondary Ion Mass Spectrometry with high-energy heavy ions (MeV-SIMS) is emerging as a promising IMS technique for chemical imaging of biological tissue. We measured the molecular mass spatial distributions in leaves of khat (Catha edulis). Khat is a natural drug plant, native to eastern Africa and the Arabian Peninsula. In these countries, fresh leaves are being chewed by significant part of population. It was reported that 80% of the adult population in Yemen chew the khat leaves. The main stimulating effects of khat are induced by a monoamine alkaloid called cathinone. During leaf ageing, cathinone is further metabolised to cathine and norephedrine. Earlier studies identified the alkaloids in khat, however little is known on their spatial distribution, reflecting the biosynthesis and accumulation in the tissue. Chemical mapping of alkaloids on cross-sections of khat leaves by MeV-SIMS was done at JSI by a pulsed 5.8 MeV 35Cl6+ beam, focused to a diameter of 15 μm, using a linear time-of-flight (TOF) spectrometer with a mass resolution of 500. In addition, measurements of MeV-SIMS mass spectra were performed at Kyoto University by a continuous broad beam of 6 MeV 63Cu4+ ions at an orthogonal TOF spectrometer with a high mass resolution of 11,000. Sections of leaves were analysed and mass spectra obtained at both MeV-SIMS setups were compared. Tissue-level distributions of detected alkaloids are presented and discussed.

  4. Pattern of khat abuse and academic performance among secondary school and college students in Jazan region, kingdom of Saudi Arabia (KSA

    Directory of Open Access Journals (Sweden)

    Rashad M Al-Sanosy

    2009-01-01

    Seventy-eight percent of those who chewed Khat were also smokers. The academic performance of those who chewed Khat was low: 39.40% had poor grades, 41% were frequently absent from classes and 39.60% were on probation as a result of poor grades. Conclusion: Most chewing sessions took place at weekends usually in social gatherings after 8 p.m. with an average duration of about 6 hours. Smoking and educational problems were more prevalent among Khat chewers. Strong preventive and control measures including early interventions and increase of awareness need to be implemented. Recreational alternatives for young people and families especially at weekends and holidays have to be found.

  5. Khat use as risk factor for psychotic disorders: A cross-sectional and case-control study in Somalia

    Directory of Open Access Journals (Sweden)

    Elbert Thomas

    2005-02-01

    Full Text Available Abstract Background Little is known about the prevalence of khat-induced psychotic disorders in East African countries, where the chewing of khat leaves is common. Its main psycho-active component cathinone produces effects similar to those of amphetamine. We aimed to explore the prevalence of psychotic disorders among the general population and the association between khat use and psychotic symptoms. Methods In an epidemiological household assessment in the city of Hargeisa, North-West Somalia, trained local interviewers screened 4,854 randomly selected persons from among the general population for disability due to severe mental problems. The identified cases were interviewed based on a structured interview and compared to healthy matched controls. Psychotic symptoms were assessed using the items of the WHO Composite International Diagnostic Interview and quantified with the Positive and Negative Symptoms Scale. Statistical testing included Student's t-test and ANOVA. Results Local interviewers found that rates of severe disability due to mental disorders were 8.4% among males (above the age of 12 and differed according to war experiences (no war experience: 3.2%; civilian war survivors: 8.0%; ex-combatants: 15.9%. The clinical interview verified that in 83% of positive screening cases psychotic symptoms were the most prominent manifestations of psychiatric illness. On average, cases with psychotic symptoms had started to use khat earlier in life than matched controls and had been using khat 8.6 years before positive symptoms emerged. In most cases with psychotic symptoms, a pattern of binge use (> two 'bundles' per day preceded the onset of psychotic symptoms, in contrast to controls of the same age. We found significant correlations between variables of khat consumption and clinical scales (0.35 to 0.50; p Conclusion Evidence indicates a relationship between the consumption of khat and the onset of psychotic symptoms among the male

  6. Disparities in risky sexual behavior among khat chewer and non- chewer college students in Southern Ethiopia: a comparative cross-sectional study.

    Science.gov (United States)

    Ware, Eyasu; Tura, Gurmesa; Alemu, Tsedach; Andarge, Eshetu

    2018-04-27

    Risky sexual behavior (RSB) and its consequence among school adolescents and youths have been well understood. It is still a common practice among college and university students living away from their controlling families compounded with the ever-worsening khat chewing habits. However, the relation between khat chewing and RSB is not well studied particularly among college students in Ethiopia. Hence, this study contributes to the literature by examining disparities of RSB among khat chewer and non-chewer students in Southern Ethiopia with the purpose of improving adolescent and youth health. An institution-based comparative cross-sectional study was conducted among 1211 college students at Arba Minch town in March 2015. Respondents were selected by employing a simple random sampling technique. Data was collected by using a pre-tested, structured, self- administered questionnaire. The data was entered into Epidata version 3.1 and analyzed using IBM SPSS statistics version 21. Level of statistical significance was declared at a p- value of pornographic movies (AOR = 2.51, 95% CI = 1.79,3.51), khat chewing (AOR = 3.02, 95% CI:=1.91,4.76) and alcohol drinking (AOR = 2.26, 95% CI = 1.54,3.35) were factors associated with RSB. Considerable proportions of students were engaged in khat chewing and RSB. RSB was significantly higher among khat chewers as compared to non- chewers. Comprehensive sexuality education was recommended to college communities and by extension to the ministry of health and education to address the identified factors so that RSB can be reshaped.

  7. Driving under the influence of khat--alkaloid concentrations and observations in forensic cases.

    Science.gov (United States)

    Toennes, Stefan W; Kauert, Gerold F

    2004-02-10

    The use of the herbal stimulant khat (Catha edulis FORSK) is maintained by immigrants from countries where it is part of their cultural life (Arabian Peninsula and eastern Africa). In western countries the drug and its effects are largely unknown and no experience in evaluating impairment symptoms due to the khat-alkaloids, e.g. cathinone, cathine and norephedrine exists. Blood and urine samples from khat users involved in 19 cases of suspected driving under the influence of drugs were analysed and correlated with the results of medical examination and police officer reports. In 3 cases impaired driving and in 10 cases marked impairment of psychophysical functions was observed such as effects on the nervous system (slow pupil reaction to light, dry mouth, increased heart-rate), trembling, restlessness/nervousness, daze/apathy/dullness, impairment of attention, walking and standing on one leg. However, the alkaloid concentrations assayed in blood did not correlate with the impairment symptoms. Apart from an acute phase of indirect sympathomimetic action the development of habituation and withdrawal symptoms must also be considered in explaining the diversity of effects observed. From these results it can be concluded that chewing khat may severely impair driving ability, but may also be without noticeable effects.

  8. Incidence of Severe Malaria Syndromes and Status of Immune Responses among Khat Chewer Malaria Patients in Ethiopia.

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    Tsige Ketema

    Full Text Available Although more emphasis has been given to the genetic and environmental factors that determine host vulnerability to malaria, other factors that might have a crucial role in burdening the disease have not been evaluated yet. Therefore, this study was designed to assess the effect of khat chewing on the incidence of severe malaria syndromes and immune responses during malaria infection in an area where the two problems co-exist. Clinical, physical, demographic, hematological, biochemical and immunological data were collected from Plasmodium falciparum mono-infected malaria patients (age ≥ 10 years seeking medication in Halaba Kulito and Jimma Health Centers. In addition, incidences of severe malaria symptoms were assessed. The data were analyzed using SPSS (version 20 software. Prevalence of current khat chewer malaria patients was 57.38% (95%CI =53-61.56%. Malaria symptoms such as hyperpyrexia, prostration and hyperparasitemia were significantly lower (P0.05, IgG3 antibody was significantly higher (P<0.001 among khat chewer malaria patients. Moreover, IgM, IgG, IgG1and IgG3 antibodies had significant negative association (P<0.001 with parasite burden and clinical manifestations of severe malaria symptoms, but not with severe anemia and hypoglycemia. Additionally, a significant increment (P<0.05 in CD4+ T-lymphocyte population was observed among khat users. Khat might be an important risk factor for incidence of some severe malaria complications. Nevertheless, it can enhance induction of humoral immune response and CD4+ T-lymphocyte population during malaria infection. This calls for further investigation on the effect of khat on parasite or antigen-specifc protective malaria immunity and analysis of cytokines released upon malaria infection among khat chewers.

  9. The consumption of khat and other drugs in Somali combatants: a cross-sectional study.

    Science.gov (United States)

    Odenwald, Michael; Hinkel, Harald; Schauer, Elisabeth; Neuner, Frank; Schauer, Maggie; Elbert, Thomas R; Rockstroh, Brigitte

    2007-12-01

    For more than a decade, most parts of Somalia have not been under the control of any type of government. This "failure of state" is complete in the central and southern regions and most apparent in Mogadishu, which had been for a long period in the hands of warlords deploying their private militias in a battle for resources. In contrast, the northern part of Somalia has had relatively stable control under regional administrations, which are, however, not internationally recognized. The present study provides information about drug abuse among active security personnel and militia with an emphasis on regional differences in relation to the lack of central governmental control-to our knowledge the first account on this topic. Trained local interviewers conducted a total of 8,723 interviews of armed personnel in seven convenience samples in different regions of Somalia; 587 (6.3%) respondents discontinued the interview and 12 (0.001%) were excluded for other reasons. We assessed basic sociodemographic information, self-reported khat use, and how respondents perceived the use of khat, cannabis (which includes both hashish and marijuana), psychoactive tablets (e.g., benzodiazepines), alcohol, solvents, and hemp seeds in their units. The cautious interpretation of our data suggest that sociodemographic characteristics and drug use among military personnel differ substantially between northern and southern/central Somalia. In total, 36.4% (99% confidence interval [CI] 19.3%-57.7%) of respondents reported khat use in the week before the interview, whereas in some regions of southern/central Somalia khat use, especially excessive use, was reported more frequently. Self-reported khat use differed substantially from the perceived use in units. According to the perception of respondents, the most frequent form of drug use is khat chewing (on average, 70.1% in previous week, 99% CI 63.6%-76.5%), followed by smoking cannabis (10.7%, 99% CI 0%-30.4%), ingesting psychoactive

  10. The consumption of khat and other drugs in Somali combatants: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Michael Odenwald

    2007-12-01

    Full Text Available BACKGROUND: For more than a decade, most parts of Somalia have not been under the control of any type of government. This "failure of state" is complete in the central and southern regions and most apparent in Mogadishu, which had been for a long period in the hands of warlords deploying their private militias in a battle for resources. In contrast, the northern part of Somalia has had relatively stable control under regional administrations, which are, however, not internationally recognized. The present study provides information about drug abuse among active security personnel and militia with an emphasis on regional differences in relation to the lack of central governmental control-to our knowledge the first account on this topic. METHODS AND FINDINGS: Trained local interviewers conducted a total of 8,723 interviews of armed personnel in seven convenience samples in different regions of Somalia; 587 (6.3% respondents discontinued the interview and 12 (0.001% were excluded for other reasons. We assessed basic sociodemographic information, self-reported khat use, and how respondents perceived the use of khat, cannabis (which includes both hashish and marijuana, psychoactive tablets (e.g., benzodiazepines, alcohol, solvents, and hemp seeds in their units. The cautious interpretation of our data suggest that sociodemographic characteristics and drug use among military personnel differ substantially between northern and southern/central Somalia. In total, 36.4% (99% confidence interval [CI] 19.3%-57.7% of respondents reported khat use in the week before the interview, whereas in some regions of southern/central Somalia khat use, especially excessive use, was reported more frequently. Self-reported khat use differed substantially from the perceived use in units. According to the perception of respondents, the most frequent form of drug use is khat chewing (on average, 70.1% in previous week, 99% CI 63.6%-76.5%, followed by smoking cannabis (10

  11. Targeting khat or targeting Somalis? A discourse analysis of project evaluations on khat abuse among Somali immigrants in Scandinavia

    Directory of Open Access Journals (Sweden)

    Nordgren Johan

    2015-09-01

    Full Text Available BACKGROUND – In Denmark, Norway and Sweden, the use of the psychoactive plant khat is widely seen as a social and health problem exclusively affecting the Somali immigrant population. Several projects by governmental and municipal bodies and agencies have been initiated to reduce khat use and abuse within this target population.

  12. Khat: ¿Una nueva droga?/Khat: A new drug?

    Directory of Open Access Journals (Sweden)

    Aitor Curiel López de Arcaute (España

    2008-08-01

    Full Text Available Una nueve droga surgió el Barcelona procedente de África subsahariana interceptada en un vuelo con destino a Nueva York. La droga conocida como Khat no es una droga nueva, es una planta de la antigüedad que surge entre los arbustos de café y se cultiva en Etiopia y Yemen y en menos escala en Kenia, Tanzania, Madagascar y Uganda. En la actualidad muchas personas consumen Khat. El costo de esta raíz varía desde 1 euro hasta 600 euros por Kg. Los efectos de esta planta son similares a los de anfetamina que producen los ingredientes activos de esta raíz los cuales están prohibidos por la ONU y la OMS. A new drug emerged in Barcelona, coming from sub-Saharan Africa, intercepted on a flight bound for New York. The drug known as Khat is not a new drug, is a plant of antiquity that emerges in the coffee bushes and cultivated in Ethiopia and Yemen and less scale in Kenya, Tanzania, Madagascar and Uganda. Nowadays many people consume Khat. The cost of this root varies from 1 euro up to 600 euros per Kg. The effects of this plant are similar to amphetamine that produce the active ingredients of this root which are prohibited by the UN and the WHO.

  13. Level of khat dependence, use patterns, and psychosocial correlates in Yemen: a cross-sectional investigation.

    Science.gov (United States)

    Nakajima, Motohiro; Hoffman, Richard; al'Absi, Mustafa

    2017-05-01

    Chronic khat use is associated with negative health consequences. However, no study has fully characterized individuals who are khat dependent. This paper examines socio-demographic and psychosocial correlates of adult khat dependence. A total of 270 khat users (129 women) in Yemen completed face-to-face interviews and provided demographic information and data on patterns of khat use, subjective mood, and sleep quality. The Severity of Dependence Scale-Khat (SDS-khat) was used to assess level of khat dependence. A series of analysis of variance was conducted. Khat users, on average, used khat for 5.2 hours a day (SD = 2.3) for 5.7 days a week (SD = 2.0). Individuals who screened positive for khat dependence reported longer duration of khat sessions per day, higher frequency of khat use per week, greater levels of negative mood and sleep disturbances, and were more likely to endorse physical symptoms after khat use (P < 0.05). Future research should elucidate mechanisms responsible for khat dependence symptomatology.

  14. Teratogenic effects of Khat (Catha edulis in New Zealand rabbit

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    Aref Saleh Abdul-Mughni

    2018-03-01

    Conclusion: Prenatal exposure of Khat in rabbit induces harmful effects in defferent visceral organs including liver, kidney, brain, spinal cord, spleen, intestine, heart and lung. [J Adv Vet Anim Res 2018; 5(1.000: 25-36

  15. Long-term effects of chronic khat use: impaired inhibitory control

    NARCIS (Netherlands)

    Colzato, L.S.; Ruiz, M.J.; van den Wildenberg, W.P.M.; Bajo, M.T.; Hommel, B.

    2011-01-01

    So far no studies have systematically looked into the cognitive consequences of khat use. This study compared the ability to inhibit and execute behavioral responses in adult khat users and khat-free controls, matched in terms of age, race, gender distribution, level of intelligence, alcohol and

  16. [Chewing and cognitive function].

    Science.gov (United States)

    Hirano, Yoshiyuki; Onozuka, Minoru

    2014-01-01

    Chewing does not only crush food to aid swallowing and digestion; it also helps to relieve stress and regulate cognitive functions, including alertness and executive function. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving. In addition, it has been shown in the elderly that a decrease in the number of residual teeth is related to dementia onset. These findings suggest a link between chewing and maintaining memory and attention. Recently, many studies regarding the effects of chewing on memory and attention were conducted using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). When a working memory task was used, the middle frontal gyrus in the dorsolateral prefrontal cortex showed greater activation in addition to producing higher alertness after chewing. Furthermore, using an attentional network test, reaction time shortened, and the anterior cingulate cortex and left frontal gyrus were both activated for the executive network. From these results, it is suggested that chewing elevates alertness, consequently leading to improvements in cognitive performance. In this review, we introduce findings concerning the effects of chewing on cognitive performance, and discuss the neuronal mechanisms underlying these effects.

  17. Influence of chewing behaviour on memory and spatial learning in albino BALB/c mice.

    Science.gov (United States)

    Aguirre Siancas, E E

    2017-05-01

    Since the relationship between chewing and cognitive functions has not been fully elucidated, this study aimed to determine the impact of chewing behaviour on spatial learning and memory in albino male BALB/c mice. Twenty mice aged 8 weeks were divided into 2 equal groups. The regular chewing group was fed with uncrushed grains (the same diet given to all 20 mice since they were weaned) and the limited chewing group was fed with crushed grains. At 16 weeks of age, the mice were evaluated over 5 days, including a 4-day acquisition phase prior to a probe test of spatial learning and memory in the Morris water maze on the fifth day. A comparison of the regular chewing group and the limited chewing group found no significant differences in either the acquisition phase or the probe test. However, there were significant differences in the acquisition phase for just the regular chewing group when comparing results from the first day to those from the other 3 days. The results suggest that regular chewing affects spatial learning and memory since mice in the regular chewing group decreased their times to find the hidden platform during the acquisition phase. Copyright © 2015 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Influence of Khat on seminal fluid among presumed infertile couples ...

    African Journals Online (AJOL)

    Results: Abnormal values were obtained for relatively older patients who also showed a higher frequency of marriage, prolonged duration of infertility and greater number of children ever fathered (p<0.05). The normal and abnormal results for khat and other drug consumers accounted for 97 (53%) and 86 (47%) in contrast ...

  19. Khat distorts the prefrontal cortex histology and function of adult ...

    African Journals Online (AJOL)

    Khat is a psychoactive herbal drug of pronounced ethno-pharmacological significance often abused due to its unregulated use. It affects many brain centers including the prefrontal cortex which is the anterior most part of the frontal lobe. The prefrontal cortex modulates working memory, planning complex cognitive ...

  20. Sleep disturbances and memory impairment among pregnant women consuming khat: An under-recognized problem

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    Md. Dilshad Manzar

    2017-01-01

    Full Text Available Khat (Catha edulis is a evergreen flowering shrub that is cultivated at high altitudes, especially in East Africa and the southwest of the Arabian Peninsula. The plant contains alkaloids, of which cathinone and cathine have structural similarity and pharmacological action similar to amphetamines. The leaves are, therefore, consumed in some regions as a psychoactive stimulant due to cultural beliefs and misperceptions on the health benefits of khat consumption. This resulted in a growing prevalence of khat consumption among pregnant women. The myriad of physiological changes associated with pregnancy impairs sleep and memory. Moreover, khat has also been shown to have adverse effects on memory and sleep. Therefore, its use during pregnancy may further aggravate those impairments. The purpose of this mini-review is to summarize the changes in sleep and memory during pregnancy and the evidence supporting a relationship between khat consumption and neurocognitive deficits and sleep dysfunctions. The misperceptions of beneficial effects of khat, the high prevalence of consumption among pregnant women, and the possibility of under-reporting of khat abuse do necessitate the development of alternative methodologies to identify cases of unreported khat abuse in pregnant women. It is proposed that screening for sleep problems and memory deficits may help identify under-reported cases of khat abuse in pregnant women.

  1. Chewing behavior and salivary secretion

    NARCIS (Netherlands)

    Gaviao, MBD; Engelen, L

    We determined the salivary flow rate in 16 healthy subjects in rest and while chewing artificial and natural foods (Parafilm, Melba toast with and without margarine, and three different volumes of breakfast cake and cheese). We also determined the duration of a chewing cycle, the number of chewing

  2. Before the ban--an exploratory study of a local khat market in East London, U.K.

    Science.gov (United States)

    Kassim, Saba; Dalsania, Asha; Nordgren, Johan; Klein, Axel; Hulbert, Josh

    2015-06-12

    Khat is a green leaf with amphetamine-like effects. It is primarily used among people in Africa, the Middle East and in the diaspora communities from these countries. Prior to the prohibition of khat in the UK on 24 June 2014, there was almost no information available on key aspects of the local khat market. A cross-sectional study was conducted in 2012 using snowball sampling, Privileged Access Interviewing and area mapping in order to identify khat sale establishments. Data was collected via face-to-face interviews using mixed methods for data collection. This included information about the establishments selling khat, khat pricing and its use among different ethnic minority groups, in addition to the potential sale of khat to children and risk assessment (e.g., use of pesticides on khat). Five out of seven sellers identified agreed to participate. Sellers described their khat sale establishments as 'community centres' which included, for example, a restaurant basement. The sellers' history of selling khat ranged between 1-15 years and khat's sale took place between 2pm-10pm. Miraa (e.g., Lara) from Kenya was the most popularly used khat variety, sold in pre-wrapped bundles of approximately 250 g costing £3 each and delivered four days a week. Harari (e.g., Owdi) from Ethiopia was sold in 200 g, 400 g and 1 kg bundles, priced between £5 and £20 and delivered two days a week. The primary benefit of khat use was reported to be social interaction. The customers were predominantly adult males of Somali origin. Most sellers claimed a self-imposed ban on sales to children under 18 years old. Khat bundles had no labelling describing variety or weight and sellers had no knowledge of the use of pesticides on khat and did not advertise the risks associated with khat use. Khat selling establishments were businesses that did not adhere to trade standards regulations (e.g., labelling khat bundles). They claimed to provide a community service (facilitating social

  3. (Catha edulis) chewing and orodental health

    African Journals Online (AJOL)

    tooth, tooth loss, gingivitis and periodontal pocketing were used as key words in various ... Case reports and studies that included only khat chewers, those that did not report ..... chronic adverse health outcomes, implying that pesticides ...

  4. Regulating khat--dilemmas and opportunities for the international drug control system.

    Science.gov (United States)

    Klein, Axel; Beckerleg, Susan; Hailu, Degol

    2009-11-01

    The regulation of khat, one of the most recent psychoactive drugs to become a globally traded commodity, remains hotly contested within different producer and consumer countries. As regimes vary, it has been possible to compare khat policies in Africa, Europe and North America from different disciplinary perspectives. Field research was conducted in East Africa and Europe, using a combination of semistructured interviews, participant observation and the analysis of trade statistics. The research established the significance of khat for rural producers, regional economies, as a tax base and source of foreign exchange. At the same time, khat as a psychoactive substance is associated with health and public safety problems that in turn are met with often ill-informed legislative responses. Bans have in turn lead to the criminalisation of users and sellers and illegal drug markets. The empirical work from Africa provides a strong argument for promoting evidence-based approaches to khat regulation, harnessing the positive aspects of the khat economy to develop a control model that incorporates the voices and respects the needs of rural producers. Ultimately, the framework for khat may provide both a model and an opportunity for revising the international treaties governing the control of other plant psychoactive-based substances.

  5. Long-term Effects of Chronic Khat Use:Impaired Inhibitory Control

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    Lorenza S Colzato

    2011-01-01

    Full Text Available So far no studies have systematically looked into the cognitive consequences of khat use. This study compared the ability to inhibit and execute behavioral responses in adult khat users and khat-free controls, matched in terms of age, race, gender distribution, level of intelligence, and alcohol, and cannabis consumption. Response inhibition and response execution were measured by a stop-signal paradigm. Results show that users and non-users are comparable in terms of response execution but users need significantly more time to inhibit responses to stop signals than non-users.

  6. Toxic effect of khat (Catha edulis on memory: Systematic review and meta-analysis

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    Birhane Alem Berihu

    2017-01-01

    Full Text Available Background: People use khat (Catha edulis for its pleasant stimulant effect of physical activity, consciousness, motor, and mental functions. Although there are reports assessing the effect of khat on memory, there was no study based on formal systematic review and meta-analysis. Objective: We have therefore conducted this meta-analysis to determine the level of evidence for the effect of khat (C. edulis Forsk on memory discrepancy. Methods: MEDLINE, Cochrane Library, PubMed, Academic Search Complete, SPORTDiscus, ScienceDirect, Scopus, Web of Science, and Google Scholar were searched to retrieve the papers for this review. Keywords utilized across database search were khat, cat, chat, long-term memory, short-term memory, memory deficit, randomized control trial, and cross-sectional survey. The search was limited to studies in humans and rodents; published in English language. Result: Finding of various studies included in our meta-analysis showed that the effect of acute, and subchronic exposure to khat showed that short-term memory appears to be affected depending on the duration of exposure. However, does not have any effect on long-term memory. Conclusion: Although a number of studies regarding the current topic are limited, the evidenced showed that khat (C. edulis induced memory discrepancy.

  7. The SPLENDID chewing detection challenge.

    Science.gov (United States)

    Papapanagiotou, Vasileios; Diou, Christos; Lingchuan Zhou; van den Boer, Janet; Mars, Monica; Delopoulos, Anastasios

    2017-07-01

    Monitoring of eating behavior using wearable technology is receiving increased attention, driven by the recent advances in wearable devices and mobile phones. One particularly interesting aspect of eating behavior is the monitoring of chewing activity and eating occurrences. There are several chewing sensor types and chewing detection algorithms proposed in the bibliography, however no datasets are publicly available to facilitate evaluation and further research. In this paper, we present a multi-modal dataset of over 60 hours of recordings from 14 participants in semi-free living conditions, collected in the context of the SPLENDID project. The dataset includes raw signals from a photoplethysmography (PPG) sensor and a 3D accelerometer, and a set of extracted features from audio recordings; detailed annotations and ground truth are also provided both at eating event level and at individual chew level. We also provide a baseline evaluation method, and introduce the "challenge" of improving the baseline chewing detection algorithms. The dataset can be downloaded from http: //dx.doi.org/10.17026/dans-zxw-v8gy, and supplementary code can be downloaded from https://github. com/mug-auth/chewing-detection-challenge.git.

  8. Imaging characteristics of meningiomas in Yemen - impact of Khat abuse

    International Nuclear Information System (INIS)

    Alansi, M.

    2011-01-01

    Intracranial meningiomas are the most common tumor derived from non-neural epithelial tissues, accounting for 13% to 26% of all intracranial tumors. In Yemen, several epidemiological studies have showed an increasing rate of meningiomas during the last 15-20 years. This can be explained by the influence of specific epidemiological factors (racial, genetic, toxic, etc) as well as, noticeably improved diagnostic imaging. A specific risk factor for Yemeni sub-population groups is chronic use of Khat (Catha Edulis Forskal, CE ) - an amphetamine-like product, associated with a variety of serious health, social and economic problems. The present study analyzed the imaging characteristics of meningiomas in Yemeni patients, who systematically use CE, compared to those who never consume it.

  9. Effects of Chewing on Cognitive Processing Speed

    Science.gov (United States)

    Hirano, Yoshiyuki; Obata, Takayuki; Takahashi, Hidehiko; Tachibana, Atsumichi; Kuroiwa, Daigo; Takahashi, Toru; Ikehira, Hiroo; Onozuka, Minoru

    2013-01-01

    In recent years, chewing has been discussed as producing effects of maintaining and sustaining cognitive performance. We have reported that chewing may improve or recover the process of working memory; however, the mechanisms underlying these phenomena are still to be elucidated. We investigated the effect of chewing on aspects of attention and…

  10. Oral health benefits of chewing gum

    NARCIS (Netherlands)

    Wessel, Stefan

    2016-01-01

    In the last decades sugar-free chewing gum has developed in an oral healthcare product, next to the conventional products such as the toothbrush and mouthrinses. In this thesis we investigate the oral health benefits of chewing gum and the effects of additives to chewing gum, such as antimicrobials.

  11. The SPLENDID chewing detection challenge

    NARCIS (Netherlands)

    Papapanagiotou, Vasileios; Diou, Christos; Zhou, Lingchuan; Boer, van den Janet; Mars, Monica; Delopoulos, Anastasios

    2017-01-01

    Monitoring of eating behavior using wearable technology is receiving increased attention, driven by the recent advances in wearable devices and mobile phones. One particularly interesting aspect of eating behavior is the monitoring of chewing activity and eating occurrences. There are several

  12. Brain Activity and Human Unilateral Chewing

    Science.gov (United States)

    Quintero, A.; Ichesco, E.; Myers, C.; Schutt, R.; Gerstner, G.E.

    2012-01-01

    Brain mechanisms underlying mastication have been studied in non-human mammals but less so in humans. We used functional magnetic resonance imaging (fMRI) to evaluate brain activity in humans during gum chewing. Chewing was associated with activations in the cerebellum, motor cortex and caudate, cingulate, and brainstem. We also divided the 25-second chew-blocks into 5 segments of equal 5-second durations and evaluated activations within and between each of the 5 segments. This analysis revealed activation clusters unique to the initial segment, which may indicate brain regions involved with initiating chewing. Several clusters were uniquely activated during the last segment as well, which may represent brain regions involved with anticipatory or motor events associated with the end of the chew-block. In conclusion, this study provided evidence for specific brain areas associated with chewing in humans and demonstrated that brain activation patterns may dynamically change over the course of chewing sequences. PMID:23103631

  13. Chewing gum differentially affects aspects of attention in healthy subjects.

    Science.gov (United States)

    Tucha, Oliver; Mecklinger, Lara; Maier, Kerstin; Hammerl, Marianne; Lange, Klaus W

    2004-06-01

    In a study published previously in this journal (Wilkinson et al., 2002), the effect of chewing gum on cognitive functioning was examined. The results of this study indicated that chewing a piece of gum results in an improvement of working memory and of both immediate and delayed recall of words but not of attention. In the present study, memory and a variety of attentional functions of healthy adult participants were examined under four different conditions: no chewing, mimicking chewing movements, chewing a piece of tasteless chewing gum and chewing a piece of spearmint flavoured chewing gum. The sequence of conditions was randomised across participants. The results showed that the chewing of gum did not improve participants' memory functions. Furthermore, chewing may differentially affect specific aspects of attention. While sustained attention was improved by the chewing of gum, alertness and flexibility were adversely affected by chewing. In conclusion, claims that the chewing a gum improves cognition should be viewed with caution.

  14. Functional Connectivity of Human Chewing

    Science.gov (United States)

    Quintero, A.; Ichesco, E.; Schutt, R.; Myers, C.; Peltier, S.; Gerstner, G.E.

    2013-01-01

    Mastication is one of the most important orofacial functions. The neurobiological mechanisms of masticatory control have been investigated in animal models, but less so in humans. This project used functional connectivity magnetic resonance imaging (fcMRI) to assess the positive temporal correlations among activated brain areas during a gum-chewing task. Twenty-nine healthy young-adults underwent an fcMRI scanning protocol while they chewed gum. Seed-based fcMRI analyses were performed with the motor cortex and cerebellum as regions of interest. Both left and right motor cortices were reciprocally functionally connected and functionally connected with the post-central gyrus, cerebellum, cingulate cortex, and precuneus. The cerebellar seeds showed functional connections with the contralateral cerebellar hemispheres, bilateral sensorimotor cortices, left superior temporal gyrus, and left cingulate cortex. These results are the first to identify functional central networks engaged during mastication. PMID:23355525

  15. 21 CFR 172.615 - Chewing gum base.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Chewing gum base. 172.615 Section 172.615 Food and..., Chewing Gum Bases and Related Substances § 172.615 Chewing gum base. The food additive chewing gum base... substances listed in paragraph (a) of this section, chewing gum base may also include substances generally...

  16. Physics of chewing in terrestrial mammals

    Science.gov (United States)

    Virot, Emmanuel; Ma, Grace; Clanet, Christophe; Jung, Sunghwan

    2017-03-01

    Previous studies on chewing frequency across animal species have focused on finding a single universal scaling law. Controversy between the different models has been aroused without elucidating the variations in chewing frequency. In the present study we show that vigorous chewing is limited by the maximum force of muscle, so that the upper chewing frequency scales as the -1/3 power of body mass for large animals and as a constant frequency for small animals. On the other hand, gentle chewing to mix food uniformly without excess of saliva describes the lower limit of chewing frequency, scaling approximately as the -1/6 power of body mass. These physical constraints frame the -1/4 power law classically inferred from allometry of animal metabolic rates. All of our experimental data stay within these physical boundaries over six orders of magnitude of body mass regardless of food types.

  17. Effects of chewing rate and reactive hyperemia on blood flow in denture-supporting mucosa during simulated chewing.

    Science.gov (United States)

    Ogino, Takamichi; Ueda, Takayuki; Ogami, Koichiro; Koike, Takashi; Sakurai, Kaoru

    2017-01-01

    We examined how chewing rate and the extent of reactive hyperemia affect the blood flow in denture-supporting mucosa during chewing. The left palatal mucosa was loaded under conditions of simulated chewing or simulated clenching for 30s, and the blood flow during loading was recorded. We compared the relative blood flow during loading under conditions that recreated different chewing rates by combining duration of chewing cycle (DCC) and occlusal time (OT): fast chewing group, typical chewing group, slow chewing group and clenching group. The relationship between relative blood flow during simulated chewing and the extent of reactive hyperemia was also analyzed. When comparing the different chewing rate, the relative blood flow was highest in fast chewing rate, followed by typical chewing rate and slow chewing rate. Accordingly, we suggest that fast chewing increases the blood flow more than typical chewing or slow chewing. There was a significant correlation between the amount of blood flow during simulated chewing and the extent of reactive hyperemia. Within the limitations of this study, we concluded that slow chewing induced less blood flow than typical or fast chewing in denture-supporting mucosa and that people with less reactive hyperemia had less blood flow in denture-supporting mucosa during chewing. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  18. Effects of chewing in working memory processing.

    Science.gov (United States)

    Hirano, Yoshiyuki; Obata, Takayuki; Kashikura, Kenichi; Nonaka, Hiroi; Tachibana, Atsumichi; Ikehira, Hiroo; Onozuka, Minoru

    2008-05-09

    It has been generally suggested that chewing produces an enhancing effect on cognitive performance-related aspects of memory by the test battery. Furthermore, recent studies have shown that chewing is associated with activation of various brain regions, including the prefrontal cortex. However, little is known about the relation between cognitive performances affected by chewing and the neuronal activity in specified regions in the brain. We therefore examined the effects of chewing on neuronal activities in the brain during a working memory task using fMRI. The subjects chewed gum, without odor and taste components, between continuously performed two- or three-back (n-back) working memory tasks. Chewing increased the BOLD signals in the middle frontal gyrus (Brodmann's areas 9 and 46) in the dorsolateral prefrontal cortex during the n-back tasks. Furthermore, there were more prominent activations in the right premotor cortex, precuneus, thalamus, hippocampus and inferior parietal lobe during the n-back tasks after the chewing trial. These results suggest that chewing may accelerate or recover the process of working memory besides inducing improvement in the arousal level by the chewing motion.

  19. Predictors of chewing ability among community-residing older adults in Korea.

    Science.gov (United States)

    Park, Kyongok; Hong, Gwi-Ryung Son

    2017-01-01

    Decreased chewing ability in older adults can lead to poor nutritional and physical conditions, and eventually death. The present study examined the relationships between chewing ability and related characteristics (e.g. health promotion habits, health status and functional status), and identified predictors of chewing ability in community-residing older adults. Among the total of 11 542 participants in the 2011 National Survey on Older Adults in Korea, data from 10 543 participants were used for analysis. Chewing ability was evaluated using a self-report of chewing ability. Exercise ability was assessed by objective exercise ability and perceived exercise ability in both the upper and lower extremities. Depression and cognitive functions were measured using the Geriatric Depression Scale-Short Form and the Mini-Mental State Examination, respectively. A total of 56.9% of participants had poor chewing abilities. After adjusting for age and sex, logistic regression analysis showed that depression (OR 1.76, 95% CI 1.60-1.92), cognitive impairment (OR 1.28, 95% CI 1.17-1.40), objective exercise ability (OR 1.24, 95% CI 1.11-1.41), regular exercise habits (OR 1.23, 95% CI 1.13-1.34), medical check-up history (OR 1.17, 95% CI 1.05-1.32), number of chronic diseases (OR 1.12, 95% CI 1.09-1.15) and perceived exercise ability in the lower extremities (OR 1.08, 95% CI 1.05-1.10) were significant predictors of chewing ability. Chewing ability in older adults should be improved in consideration of mental and general health condition. Geriatr Gerontol Int 2017; 17: 78-84. © 2015 Japan Geriatrics Society.

  20. Anger, anxiety, and depressive affect as predictors of stress-induced cortisol production in khat and tobacco users.

    Science.gov (United States)

    Lemieux, Andrine M; Nakajima, Motohiro; Saif-Ali, Riyadh; Al-Habori, Molham; Dokam, Anisa; al'Absi, Mustafa

    2018-07-01

    Glucocorticoid activity is disrupted in substance users including khat chewers who also use tobacco. Anger, dysphoria, and anxiety can mediate this relationship. The aim of this study was to contrast emotion dysregulation and substance use variables as predictors of post-stress cortisol output. Comparable numbers of males (n = 90) and females (n = 85) including controls, khat only, and concurrent khat and tobacco users participated in a stress study. Depressive affect, anxiety, anger, substance use patterns, and saliva samples were collected following a standardized laboratory stress manipulation. Regression analysis showed that high depression and low anxiety was associated with high post-stress cortisol, but only in co-users of tobacco and khat. Males, but not females, showed a significant association between co-use of khat and tobacco and cortisol, which appears to be mediated by frequency of use. The link between anxiety and post-stress cortisol in the co-users remained significant after controlling for nicotine dependence and substance use frequency. Anxiety predicted the neuroendocrine consequences of concurrent use of tobacco and khat above and beyond sex, nicotine dependence, anger, and substance use frequency. Sex differences, however, are related to differences in nicotine dependence. Copyright © 2018. Published by Elsevier Ltd.

  1. Gum chewing and cognition : an overview

    NARCIS (Netherlands)

    Tucha, L.I.; Koerts, J.

    In recent years, there was a debate about the effects of gum chewing on various aspects of cognitive functioning. In this review, the results of previous studies are presented and summarized. There is a clear indication that gum chewing can improve various aspects of cognitive functioning including

  2. Gum chewing affects academic performance in adolescents

    Science.gov (United States)

    Chewing gum may have an impact on improved memory during specific tasks of recognition and sustained attention. Research objective was to determine the effect of gum chewing on standardized test scores and math class grades of eighth grade students. Four math classes, 108 students, were randomized i...

  3. Formulation and characterization of caffeine biodegradable chewing ...

    African Journals Online (AJOL)

    chewing gum delivery system for alertness using ... texture profile analysis (TPA), and also evaluated for biodegradation, microstructure`, in vitro .... human chewing. .... Data are presented as mean ± standard error mean (n=6) .... No conflict of interest associated with this work. ... d), which permit unrestricted use, distribution,.

  4. Effect of gum hardness on chewing pattern.

    Science.gov (United States)

    Plesh, O; Bishop, B; McCall, W

    1986-06-01

    Chewing rhythms are set by a putative central pattern generator whose output is influenced by sensory feedback. In this study we assessed how an altered feedback imposed by changing the hardness of a gum bolus modifies the timing of chewing, the maximal gape, and the activity in the masseter muscle on the chewing side. Ten adult subjects with no orofacial dysfunction chewed a standard piece of soft or hard gum for at least 3 min in random order. Vertical jaw movements were recorded with a kinesiograph and activity of the masseter muscle was recorded and integrated from surface EMG electrodes. The subjects sat in a dental chair and viewed a video lecture to distract their attention from chewing; they were instructed to chew on the right molars. Cycle-by-cycle analysis showed that 9 of the 10 subjects chewed the hard gum more slowly than the soft with no significant change in gape. The increases in cycle duration were due to changes in the duration of the opening and occlusal phases. The duration of closing was not significantly changed even though the duration and level of masseter activity were both significantly increased. We conclude that gum hardness by altering proprioceptive feedback modifies the output of the masticatory central pattern generator in such a way that the temporal aspects of chewing and the output of the masseteric motor pool are affected.

  5. Association Between Chewing Difficulty and Symptoms of Depression in Adults: Results from the Korea National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Shin, Hye-Sun; Ahn, Yong-Soon; Lim, Do-Seon

    2016-12-01

    To assess the association between chewing difficulty and symptoms of depression in a representative sample of the Korean population. Cross-sectional. Korea National Health and Nutrition Examination Survey (KNHANES). KNHANES participants (N = 5,158). Chewing difficulty was assessed according to the self-reported presence of chewing problems using a structured questionnaire. Symptoms of depression were defined as having feelings of sadness or depression consecutively over 2 weeks during the last 12 months. Multivariable logistic regression analysis was used to determine the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) of the associations between chewing difficulty and symptoms of depression, adjusted for age; sex; monthly household income; education; number of teeth; number of decayed, missing, or filled permanent teeth; periodontitis; state of dentition; tooth brushing frequency; regular dental visits; smoking status; alcohol consumption; hypertension; diabetes mellitus; and obesity. The interaction effects between chewing difficulty and confounders were evaluated, and age- and sex-stratified analyses were performed. There was a significant positive association between chewing difficulty and symptoms of depression in the fully adjusted model (AOR = 1.86, 95% CI = 1.48-2.33). The strength of the association was highest in men aged 60 and older (AOR = 3.28, 95% CI = 1.54-7.00). Chewing difficulty was independently associated with symptoms of depression in a representative sample of Korean adults. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  6. Women's rights, a tourist boom, and the power of khat in Yemen.

    Science.gov (United States)

    Kandela, P

    2000-04-22

    This article discusses the issues of women's rights, the tourism and the prevalent use of khat in Yemen, based on the author's experience. Widespread social and legal discrimination against women has resulted from the changes occurring in Yemen. This situation is exacerbated by the lack of action from the government, which has alarmed the women's organization. Despite exerted efforts by nongovernmental organizations in controlling this situation, programs continue to fail due to obstructions from government officials. In addition, the changes encountered by the country had resulted to a high profile of kidnapping tourists for the past years. The income from the tourism is too important to be jeopardized; thus the government provided an impetus for the development of the country's infrastructure. The intent of the government towards modernization, however, tends to be sapped by the extensive use of khat. The author states that unless substantial medical evidence is forthcoming about ill effects of the substance, significant impact on the widespread use of khat is unlikely.

  7. Chewing gum moderates the vigilance decrement.

    Science.gov (United States)

    Morgan, Kate; Johnson, Andrew J; Miles, Christopher

    2014-05-01

    We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in post-task self-rated alertness scores. The declines in both performance and subjective alertness were attenuated in the chewing-gum group. In particular, correct RTs were significantly shorter following the chewing of gum in the latter stages of the task. Additionally, the gradients of decline for target detection and incline for correct RTs were both attenuated for the chewing-gum group. These findings are consistent with the data of Tucha and Simpson (2011), Appetite, 56, 299-301, who showed beneficial effects of chewing gum in the latter stages of a 30 min visual attention task, and extend their data to a task that necessitates the continuous updating of order memory. It is noteworthy that our data contradict the claim (Kozlov, Hughes, & Jones, 2012, Q. J. Exp. Psychology, 65, 501-513) that chewing gum negatively impacts short-term memory task performance. © 2013 The British Psychological Society.

  8. Brief Report: Gum Chewing Affects Standardized Math Scores in Adolescents

    Science.gov (United States)

    Johnston, Craig A.; Tyler, Chermaine; Stansberry, Sandra A.; Moreno, Jennette P.; Foreyt, John P.

    2012-01-01

    Gum chewing has been shown to improve cognitive performance in adults; however, gum chewing has not been evaluated in children. This study examined the effects of gum chewing on standardized test scores and class grades of eighth grade math students. Math classes were randomized to a gum chewing (GC) condition that provided students with gum…

  9. The CT appearance of intraoral chewing gum

    International Nuclear Information System (INIS)

    Towbin, Alexander J.

    2008-01-01

    When imaged, intraoral chewing gum has the potential to be misdiagnosed. Chewing gum has a characteristic appearance on CT: it is ovoid in shape, hyperdense, and has small internal locules of air. Reports have described the appearance of gum on radiographs and abdominal CT images; however, no reports could be found detailing its appearance within the mouth. This report describes the appearance of intraoral chewing gum as well as the properties of the gum that lead to this appearance. Because of the potential for misdiagnosis, screening for intraoral foreign bodies should be considered prior to imaging. (orig.)

  10. The CT appearance of intraoral chewing gum

    Energy Technology Data Exchange (ETDEWEB)

    Towbin, Alexander J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2008-12-15

    When imaged, intraoral chewing gum has the potential to be misdiagnosed. Chewing gum has a characteristic appearance on CT: it is ovoid in shape, hyperdense, and has small internal locules of air. Reports have described the appearance of gum on radiographs and abdominal CT images; however, no reports could be found detailing its appearance within the mouth. This report describes the appearance of intraoral chewing gum as well as the properties of the gum that lead to this appearance. Because of the potential for misdiagnosis, screening for intraoral foreign bodies should be considered prior to imaging. (orig.)

  11. Effects of chewing on cognitive processing speed.

    Science.gov (United States)

    Hirano, Yoshiyuki; Obata, Takayuki; Takahashi, Hidehiko; Tachibana, Atsumichi; Kuroiwa, Daigo; Takahashi, Toru; Ikehira, Hiroo; Onozuka, Minoru

    2013-04-01

    In recent years, chewing has been discussed as producing effects of maintaining and sustaining cognitive performance. We have reported that chewing may improve or recover the process of working memory; however, the mechanisms underlying these phenomena are still to be elucidated. We investigated the effect of chewing on aspects of attention and cognitive processing speed, testing the hypothesis that this effect induces higher cognitive performance. Seventeen healthy adults (20-34 years old) were studied during attention task with blood oxygenation level-dependent functional (fMRI) at 3.0 T MRI. The attentional network test (ANT) within a single task fMRI containing two cue conditions (no cue and center cue) and two target conditions (congruent and incongruent) was conducted to examine the efficiency of alerting and executive control. Participants were instructed to press a button with the right or left thumb according to the direction of a centrally presented arrow. Each participant underwent two back-to-back ANT sessions with or without chewing gum, odorless and tasteless to remove any effect other than chewing. Behavioral results showed that mean reaction time was significantly decreased during chewing condition, regardless of speed-accuracy trade-off, although there were no significant changes in behavioral effects (both alerting and conflict effects). On the other hand, fMRI analysis revealed higher activations in the anterior cingulate cortex and left frontal gyrus for the executive network and motor-related regions for both attentional networks during chewing condition. These results suggested that chewing induced an increase in the arousal level and alertness in addition to an effect on motor control and, as a consequence, these effects could lead to improvements in cognitive performance. Published by Elsevier Inc.

  12. The effect of mouth breathing on chewing efficiency.

    Science.gov (United States)

    Nagaiwa, Miho; Gunjigake, Kaori; Yamaguchi, Kazunori

    2016-03-01

    To examine the effect of mouth breathing on chewing efficiency by evaluating masticatory variables. Ten adult nasal breathers with normal occlusion and no temporomandibular dysfunction were selected. Subjects were instructed to bite the chewing gum on the habitual side. While breathing through the mouth and nose, the glucide elution from the chewing gum, number of chewing strokes, duration of chewing, and electromyography (EMG) activity of the masseter muscle were evaluated as variables of masticatory efficiency. The durations required for the chewing of 30, 60, 90, 120, 180, and 250 strokes were significantly (P chewing stroke between nose and mouth breathings. The glucide elution rates for 1- and 3-minute chewing were significantly (P chewing between nose and mouth breathings. While chewing for 1, 3, and 5 minutes, the chewing stroke and EMG activity of the masseter muscle were significantly (P chewing to obtain higher masticatory efficiency when breathing through the mouth. Therefore, mouth breathing will decrease the masticatory efficiency if the duration of chewing is restricted in everyday life.

  13. Adaptive regularization

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Rasmussen, Carl Edward; Svarer, C.

    1994-01-01

    Regularization, e.g., in the form of weight decay, is important for training and optimization of neural network architectures. In this work the authors provide a tool based on asymptotic sampling theory, for iterative estimation of weight decay parameters. The basic idea is to do a gradient desce...

  14. Chewing Tobacco: Not a Safe Alternative to Cigarettes

    Science.gov (United States)

    Healthy Lifestyle Quit smoking Get the facts about chewing tobacco and other forms of smokeless tobacco. They' ... than you might think. By Mayo Clinic Staff Chewing tobacco and other smokeless tobacco products may be ...

  15. Camptothecin and khat (Catha edulis Forsk. induced distinct cell death phenotypes involving modulation of c-FLIPL, Mcl-1, procaspase-8 and mitochondrial function in acute myeloid leukemia cell lines

    Directory of Open Access Journals (Sweden)

    Fossan Kjell O

    2009-11-01

    Full Text Available Abstract Background An organic extract of the recreational herb khat (Catha edulis Forsk. triggers cell death in various leukemia cell lines in vitro. The chemotherapeutics camptothecin, a plant alkaloid topoisomerase I inhibitor, was tested side-by-side with khat in a panel of acute myeloid leukemia cell lines to elucidate mechanisms of toxicity. Results Khat had a profound effect on MOLM-13 cells inducing mitochondrial damage, chromatin margination and morphological features of autophagy. The effects of khat on mitochondrial ultrastructure in MOLM-13 correlated with strongly impaired routine respiration, an effect neither found in the khat-resistant MV-4-11 cells nor in camptothecin treated cells. Enforced expression of anti-apoptotic Bcl-2 protein provided protection against camptothecin-induced cell death and partly against khat toxicity. Khat-induced cell death in MOLM-13 cells included reduced levels of anti-apoptotic Mcl-1 protein, while both khat and camptothecin induced c-FLIPL cleavage and procaspase-8 activation. Conclusion Khat activated a distinct cell death pathway in sensitive leukemic cells as compared to camptothecin, involving mitochondrial damage and morphological features of autophagy. This suggests that khat should be further explored in the search for novel experimental therapeutics.

  16. Chewing and Attention: A Positive Effect on Sustained Attention

    OpenAIRE

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

    Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We ...

  17. Temporomandibular Disorders: The Habitual Chewing Side Syndrome

    Science.gov (United States)

    Santana-Mora, Urbano; López-Cedrún, José; Mora, María J.; Otero, Xosé L.; Santana-Penín, Urbano

    2013-01-01

    Background Temporomandibular disorders are the most common cause of chronic orofacial pain, but, except where they occur subsequent to trauma, their cause remains unknown. This cross-sectional study assessed chewing function (habitual chewing side) and the differences of the chewing side and condylar path and lateral anterior guidance angles in participants with chronic unilateral temporomandibular disorder. This is the preliminary report of a randomized trial that aimed to test the effect of a new occlusal adjustment therapy. Methods The masticatory function of 21 randomly selected completely dentate participants with chronic temporomandibular disorders (all but one with unilateral symptoms) was assessed by observing them eat almonds, inspecting the lateral horizontal movement of the jaw, with kinesiography, and by means of interview. The condylar path in the sagittal plane and the lateral anterior guidance angles with respect to the Frankfort horizontal plane in the frontal plane were measured on both sides in each individual. Results Sixteen of 20 participants with unilateral symptoms chewed on the affected side; the concordance (Fisher’s exact test, P = .003) and the concordance-symmetry level (Kappa coefficient κ = 0.689; 95% confidence interval [CI], 0.38 to 0.99; P = .002) were significant. The mean condylar path angle was steeper (53.47(10.88) degrees versus 46.16(7.25) degrees; P = .001), and the mean lateral anterior guidance angle was flatter (41.63(13.35) degrees versus 48.32(9.53) degrees P = .036) on the symptomatic side. Discussion The results of this study support the use of a new term based on etiology, “habitual chewing side syndrome”, instead of the nonspecific symptom-based “temporomandibular joint disorders”; this denomination is characterized in adults by a steeper condylar path, flatter lateral anterior guidance, and habitual chewing on the symptomatic side. PMID:23593156

  18. Temporomandibular disorders: the habitual chewing side syndrome.

    Directory of Open Access Journals (Sweden)

    Urbano Santana-Mora

    Full Text Available BACKGROUND: Temporomandibular disorders are the most common cause of chronic orofacial pain, but, except where they occur subsequent to trauma, their cause remains unknown. This cross-sectional study assessed chewing function (habitual chewing side and the differences of the chewing side and condylar path and lateral anterior guidance angles in participants with chronic unilateral temporomandibular disorder. This is the preliminary report of a randomized trial that aimed to test the effect of a new occlusal adjustment therapy. METHODS: The masticatory function of 21 randomly selected completely dentate participants with chronic temporomandibular disorders (all but one with unilateral symptoms was assessed by observing them eat almonds, inspecting the lateral horizontal movement of the jaw, with kinesiography, and by means of interview. The condylar path in the sagittal plane and the lateral anterior guidance angles with respect to the Frankfort horizontal plane in the frontal plane were measured on both sides in each individual. RESULTS: Sixteen of 20 participants with unilateral symptoms chewed on the affected side; the concordance (Fisher's exact test, P = .003 and the concordance-symmetry level (Kappa coefficient κ = 0.689; 95% confidence interval [CI], 0.38 to 0.99; P = .002 were significant. The mean condylar path angle was steeper (53.47(10.88 degrees versus 46.16(7.25 degrees; P = .001, and the mean lateral anterior guidance angle was flatter (41.63(13.35 degrees versus 48.32(9.53 degrees P = .036 on the symptomatic side. DISCUSSION: The results of this study support the use of a new term based on etiology, "habitual chewing side syndrome", instead of the nonspecific symptom-based "temporomandibular joint disorders"; this denomination is characterized in adults by a steeper condylar path, flatter lateral anterior guidance, and habitual chewing on the symptomatic side.

  19. Chewing gum moderates the vigilance decrement.

    OpenAIRE

    Morgan, K.; Johnson, A.J.; Miles, C..

    2014-01-01

    We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in p...

  20. The effect of grain type and processing on chewing activity in horses

    DEFF Research Database (Denmark)

    Brøkner, Christine; Nørgaard, Peder; Eriksen, Lis

    2005-01-01

    The aims of the present experiment were to study the effect of grain type and processing on chewing activity in horses. Three adult trotters (Exp.I) and 3 adult Icelandic horses (Exp.II) were fed 3 daily meals during 3 consecutive days in two 3 x 3 completely randomized block design experiments....... Meals of (Exp.I: 1.0 kg) and (Exp.II: 0.5 kg) oats, barley and wheat were fed whole, rolled and ground at 10 am, 12 pm, 2 pm. Jaw movements (JM) were identified from pressure oscillations in a tube around the mouth. The efficient chewing time (EPTIME, min/kg DM), corrected for pauses, the basic chewing...... rate (PBCR, JM/s) and the standard deviation of time interval between JM (SPDDT), which indicate chewing regularity, were estimated. The mean EPTIME was 24 and 15 min for the Icelandic and trotter horses, respectively. The EPTIME for whole grain was 20 min and shorter than for ground grain (P = 0...

  1. Relationship between betel quid chewing and radiographic alveolar bone loss among Taiwanese aboriginals: a retrospective study.

    Science.gov (United States)

    Hsiao, Chun-Nan; Ting, Chun-Chan; Shieh, Tien-Yu; Ko, Edward Chengchuan

    2014-11-04

    Betel quid chewing is associated with the periodontal status; however, results of epidemiological studies are inconsistent. To the best of our knowledge, no study has reported radiographic alveolar bone loss (RABL) associated with betel quid chewing. This survey was conducted in an aboriginal community in Taiwan because almost all betel quid chewers were city-dwelling cigarette smokers. In total, 114 subjects, aged 30-60 years, were included. Full-mouth intraoral RABL was retrospectively measured and adjusted for age, gender, and plaque index (PI). Multiple regression analysis was used to assess the relationship between RABL and potential risk factors. Age-, gender-, and PI-adjusted mean RABL was significantly higher in chewers with or without cigarette smoking than in controls. Multiple regression analysis showed that the RABL for consumption of 100,000 pieces betel quid for the chewer group was 0.40 mm. Full-mouth plotted curves for adjusted mean RABL in the maxilla were similar between the chewer and control groups, suggesting that chemical effects were not the main factors affecting the association between betel quid chewing and the periodontal status. Betel quid chewing significantly increases RABL. The main contributory factors are age and oral hygiene; however, the major mechanism underlying this process may not be a chemical mechanism. Regular dental visits, maintenance of good oral hygiene, and reduction in the consumption of betel quid, additives, and cigarettes are highly recommended to improve the periodontal status.

  2. [Epidemiological investigation of chewing fresh or dried betel nut and oral mucosal disease].

    Science.gov (United States)

    Yongxiu, Du; Dongye, Sun; Xinchun, Jian; Qiuhua, Mao; Yanan, Cheng; Pu, Xu

    2016-08-01

    This study was conducted to investigate the effect of chewing fresh or dried betel nut on the inci-dence and canceration of oral mucosa disease in Haikou City in Hainan Province. Through a survey questionnaire, clinical examination, and regular follow-up, we collected clinical data from 1 722 cases and divided them into two groups, among which 704 of the afflicted people chew dried betel nut, whereas the other 1 018 chew fresh betel nut. The data were 
statistically analyzed using different variables which included age, number, time of onset of the disease, and the cancerous condition associated with common oral mucosa disease, including oral submucous fibrosis (OSF), oral leukoplakia (OLK), and oral Lichen planus (OLP). 1) The study found no significant difference in the prevalence of oral mucosa diseases between the dried betel nut group (n=704) and fresh betel nut group (n=1 018) among the 1 722 cases (P>0.05), but the peak age of oral mucosal disease was more advanced in the dried betel nut group (Pbetel nut group was significantly higher than that in the fresh betel nut group (Pbetel nut group was significantly higher than that in the fresh betel nut group (Pbetel nut is more pathogenic and carcinogenic than chewing fresh betel nut. The extremely harmful components of the dried betel nut synergistically play a vital role in the occurrence and carcinogenesis of oral mucosal diseases.

  3. Effect of chewing speed on energy expenditure in healthy subjects.

    Science.gov (United States)

    Paphangkorakit, Jarin; Leelayuwat, Naruemon; Boonyawat, Nattawat; Parniangtong, Auddamar; Sripratoom, Jindamanee

    2014-08-01

    The aim of the study was to investigate the effect of rate of chewing on energy expenditure in human subjects. Fourteen healthy subjects (aged 18-24 years) within the normal range of BMI participated in a cross-over experiment consisting of two 6-min sessions of gum chewing, slow (∼60 cycles/min) and fast (∼120 cycles/min) chewing. The resting energy expenditure (REE) and during gum chewing was measured using a ventilated hood connected to a gas analyzer system. The normality of data was explored using the Shapiro-Wilk test. The energy expenditure rate during chewing and the energy expenditure per chewing cycle were compared between the two chewing speeds using Wilcoxon signed ranks tests. The energy expenditure per chewing cycle during slow chewing (median 1.4, range 5.2 cal; mean 2.1±1.6 cal) was significantly higher than that during fast chewing (median 0.9, range 2.2 cal; mean 1.0±0.7 cal) (p chewing speeds (p > 0.05). The results of this study suggest that chewing at a slower speed could increase the energy expenditure per cycle and might affect the total daily energy expenditure.

  4. Quantification and Qualification of Bacteria Trapped in Chewed Gum

    NARCIS (Netherlands)

    Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.

    2015-01-01

    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and

  5. Differences between the chewing and non-chewing sides of the mandibular first molars and condyles in the closing phase during chewing in normal subjects.

    Science.gov (United States)

    Tomonari, Hiroshi; Kwon, Sangho; Kuninori, Takaharu; Miyawaki, Shouichi

    2017-09-01

    This study aimed to assess differences between the closing paths of the chewing and non-chewing sides of mandibular first molars and condyles during natural mastication, using standardized model food in healthy subjects. Thirty-two healthy young adults (age: 19-25 years; 22 men, 10 women) with normal occlusion and function chewed on standardized gummy jelly. Using an optoelectric jaw-tracking system with six degrees of freedom, we recorded the path of the mandibular first molars and condyles on both sides for 10 strokes during unilateral chewing. Variables were compared between the chewing side and the non-chewing side of first molars and condyles on frontal, sagittal, and horizontal views during the early-, middle- and late-closing phases. On superior/inferior displacements, the chewing side first molar and condyle were positioned superior to those on the non-chewing side during the early- and middle-closing phases. Conversely, the first molar and condyle on the non-chewing side were positioned significantly superior to those on the chewing side during the late-closing phase. On anterior/posterior displacements, the chewing side mandibular first molar and condyle were positioned significantly posterior to those on the non-chewing side throughout all closing phases. Our results showed the differences between the mandibular first molars and condyles on both sides with respect to masticatory path during natural chewing of a model food. These differences can be useful for informing initial diagnostic tests for impaired masticatory function in the clinical environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Chewing gum and context-dependent memory: The independent roles of chewing gum and mint flavour

    OpenAIRE

    Johnson, A.J.; Miles, C.

    2008-01-01

    Two experiments independently investigated the basis of the chewing-gum induced context-dependent memory effect (Baker et al, 2004). At learning and/or recall participants either chewed flavourless gum (Experiment 1) or received mint-flavoured strips (Experiment 2). No context dependent memory effect was found with either flavourless gum or mint-flavoured strips, indicating that independently the contexts were insufficiently salient to induce the effect. This is found despite participants’ su...

  7. Chewing gum can produce context-dependent effects upon memory.

    Science.gov (United States)

    Baker, Jess R; Bezance, Jessica B; Zellaby, Ella; Aggleton, John P

    2004-10-01

    Two experiments examined whether chewing spearmint gum can affect the initial learning or subsequent recall of a word list. Comparing those participants in Experiment 1 who chewed gum at the learning or the recall phases showed that chewing gum at initial learning was associated with superior recall. In addition, chewing gum led to context-dependent effects as a switch between gum and no gum (or no gum and gum) between learning and recall led to poorer performance. Experiment 2 provided evidence that sucking gum was sufficient to induce some of the same effects as chewing.

  8. Phytase application in chewing gum - A technical assessment

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Meyer, Anne S.

    2016-01-01

    either prior to ingestion, i.e. in the food, or post ingestion, i.e. in the human gastrointestinal tract. We have assessed the technical aspects of formulation and release of phytase added to chewing gum as a delivery vehicle. Phytases from Aspergillus niger and Escherichia coli incorporated into chewing...... gum were released quantitatively upon chewing and retained phytase activity (50-80% of the enzyme activity added was released within 10 minutes). Initial evaluations of phytase chewing gum shelf life showed good stability after 48 days of storage of the chewing gum at ambient conditions....

  9. Regular use of alcohol and tobacco in India and its association with age, gender, and poverty.

    Science.gov (United States)

    Neufeld, K J; Peters, D H; Rani, M; Bonu, S; Brooner, R K

    2005-03-07

    This study provides national estimates of regular tobacco and alcohol use in India and their associations with gender, age, and economic group obtained from a representative survey of 471,143 people over the age of 10 years in 1995-96, the National Sample Survey. The national prevalence of regular use of smoking tobacco is estimated to be 16.2%, chewing tobacco 14.0%, and alcohol 4.5%. Men were 25.5 times more likely than women to report regular smoking, 3.7 times more likely to regularly chew tobacco, and 9.7 times more likely to regularly use alcohol. Respondents belonging to scheduled castes and tribes (recognized disadvantaged groups) were significantly more likely to report regular use of alcohol as well as smoking and chewing tobacco. People from rural areas had higher rates compared to urban dwellers, as did those with no formal education. Individuals with incomes below the poverty line had higher relative odds of use of chewing tobacco and alcohol compared to those above the poverty line. The regular use of both tobacco and alcohol also increased significantly with each diminishing income quintile. Comparisons are made between these results and those found in the United States and elsewhere, highlighting the need to address control of these substances on the public health agenda.

  10. Efficacy of baking soda-containing chewing gum in removing natural tooth stain.

    Science.gov (United States)

    Mankodi, S M; Conforti, N; Berkowitz, H

    2001-07-01

    A 14-week, double-blind, randomized clinical trial was conducted with 126 healthy volunteers to compare the efficacy of twice-daily use of 3 baking soda-containing chewing gums in removing natural tooth stain when used in conjunction with a program of regular oral hygiene. All 3 chewing gums significantly reduced extrinsic stain (P Baking Soda Gum (AHDC) reduced dental stain by 70.8%, compared to reductions of 71.9% and 65.3%, after use of 2 experimental gum formulations. Whitened appearance improved by 1.73 shade tabs using AHDC gum, and up to 2.49 shade tabs with the experimental formulations. These results suggest that the use of baking soda-containing gum after meals, in conjunction with good oral hygiene, can improve both extrinsic dental staining and the whitened appearance of teeth.

  11. Determinants of CD4 counts among HIV-Negative ethiopians: Role of body mass index, gender, cigarette smoking, khat (Catha edulis) chewing, and possibly altitude?

    NARCIS (Netherlands)

    Abuye, C.; Tsegaye, A.; West, C. E.; Versloot, P.; Sanders, E. J.; Wolday, D.; Hamann, D.; Rinke de Wit, T. F.; Fontanet, A. L.

    2005-01-01

    To study the determinants of CD4% and CD4 counts among HIV-negative Ethiopians, and to identify factors susceptible to explain the low CD4 counts observed among Ethiopian subjects. Cohort studies among factory workers in Akaki and Wonji, Ethiopia. Clinical and laboratory examinations, including

  12. What Type of Food Can Older Adults Masticate?: Evaluation of Mastication Performance Using Color-Changeable Chewing Gum.

    Science.gov (United States)

    Wada, Shinichi; Kawate, Nobuyuki; Mizuma, Masazumi

    2017-10-01

    This study determines if older adults can masticate regular foods via a simple test conducted using a color-changeable chewing gum. Seventy-nine consecutive inpatients of our clinic receiving rehabilitation and general medicine were assessed for eligibility. The inclusion criterion was >65 years. Thirty patients consented to participate. The main outcome variable was the food bolus texture at the swallowing threshold for five regular foods. The main explanatory variable was the a* value of the color-changeable chewing gum after 120 s of chewing (a* represents the degree of color between red and green, and a positive a* value indicates red). The mean age ± standard deviation of the participants was 81.6 ± 8.6 years, and 40% were men. Participants being able to prepare the food with suitable texture for swallowing was positively associated with the a* values in boiled rice, ginger-fried pork loin, boiled fish-paste, and rice cracker (Crude OR 1.18, 1.15, 1.17, and 1.50; P chewing gum is not only useful but also extremely practical, even for older adults in a wide range of settings, including an individual's home. This approach would lead to a reduction in unnecessary mechanically altered or pureed food for older adults who can eat pureed food and safely provide palatable food.

  13. Chew-Low equations as Cremoma transformations

    International Nuclear Information System (INIS)

    Rerikh, K.V.

    1982-01-01

    The Chew-Low equations for the p-wave pion-nucleon scattering with the crossing-symmetry matrix (3x3) are investigated in their well-known formulation as a system of nonlinear difference equations. These equations interpreted as geometrical transformations are shown to be a special case of the Cremona transformaions. Using the properties of the Cremona transformations we obtain the general 3-parametric functional equation on invariant algebraic and nonalgebraic curves in the space solutions of the Chew- Low equations. It is proved that there exists only one invariant algebraic curve, the parabola corresponding to the well-known solution. Analysis of the general functional equation on invariant nonalgebraic curves makes it possible to select in addition to this parabola 3 invariant forms defining implicitly 3 nonalgebraic curves and to concretize for them the general equation by means of fixing the parameters. From the transformational properties of the invariant forms with respect to the Cremona transformations, there follows an important result that the ration of these forms in proper powers is the general integral of the nonlinear system of the Chew-Low equations, which is an even antiperiodic function. The structure of the second general integral is given and the functional equations which determinne this integral are presented [ru

  14. The Epidemiology of Sleep Quality, Sleep Patterns, Consumption of Caffeinated Beverages, and Khat Use among Ethiopian College Students

    OpenAIRE

    Lemma, Seblewengel; Patel, Sheila V.; Tarekegn, Yared A.; Tadesse, Mahlet G.; Berhane, Yemane; Gelaye, Bizu; Williams, Michelle A.

    2012-01-01

    Objective:. To evaluate sleep habits, sleep patterns, and sleep quality among Ethiopian college students; and to examine associations of poor sleep quality with consumption of caffeinated beverages and other stimulants. Methods:. A total of 2,230 undergraduate students completed a self-administered comprehensive questionnaire which gathered information about sleep complaints, sociodemographic and lifestyle characteristics,and theuse of caffeinated beverages and khat. We used multivariable log...

  15. Chewing gum and context-dependent memory: the independent roles of chewing gum and mint flavour.

    Science.gov (United States)

    Johnson, Andrew J; Miles, Christopher

    2008-05-01

    Two experiments independently investigated the basis of the chewing gum induced context-dependent memory effect. At learning and/or recall, participants either chewed flavourless gum (Experiment 1) or received mint-flavoured strips (Experiment 2). No context-dependent memory effect was found with either flavourless gum or mint-flavoured strips, indicating that independently the contexts were insufficiently salient to induce the effect. This is found despite participants' subjective ratings indicating a perceived change in state following administration of flavourless gum or mint-flavoured strips. Additionally, some preliminary evidence for a non-additive facilitative effect of receiving gum or flavour at either learning and/or recall is reported. The findings raise further concerns regarding the robustness of the previously reported context-dependent memory effect with chewing gum.

  16. The Epidemiology of Sleep Quality, Sleep Patterns, Consumption of Caffeinated Beverages, and Khat Use among Ethiopian College Students.

    Science.gov (United States)

    Lemma, Seblewengel; Patel, Sheila V; Tarekegn, Yared A; Tadesse, Mahlet G; Berhane, Yemane; Gelaye, Bizu; Williams, Michelle A

    2012-01-01

    Objective. To evaluate sleep habits, sleep patterns, and sleep quality among Ethiopian college students; and to examine associations of poor sleep quality with consumption of caffeinated beverages and other stimulants. Methods. A total of 2,230 undergraduate students completed a self-administered comprehensive questionnaire which gathered information about sleep complaints, sociodemographic and lifestyle characteristics,and theuse of caffeinated beverages and khat. We used multivariable logistic regression procedures to estimate odds ratios for the associations of poor sleep quality with sociodemographic and behavioral factors. Results. Overall 52.7% of students were classified as having poor sleep quality (51.8% among males and 56.9% among females). In adjusted multivariate analyses, caffeine consumption (OR = 1.55; 95% CI: 1.25-1.92), cigarette smoking (OR = 1.68; 95% CI: 1.06-2.63), and khat use (OR = 1.72, 95% CI: 1.09-2.71) were all associated with increased odds of long-sleep latency (>30 minutes). Cigarette smoking (OR = 1.74; 95% CI: 1.11-2.73) and khat consumption (OR = 1.91; 95% CI: 1.22-3.00) were also significantly associated with poor sleep efficiency (sleep medicine. Conclusion. Findings from the present study demonstrate the high prevalence of poor sleep quality and its association with stimulant use among college students. Preventive and educational programs for students should include modules that emphasize the importance of sleep and associated risk factors.

  17. Oral health benefits of a daily dental chew in dogs.

    Science.gov (United States)

    Quest, Bradley W

    2013-01-01

    An independent study was conducted to determine and quantify the oral care benefits of a daily edible dental chew in dogs as measured by plaque and calculus control, gingival indices, and oral malodor. A "clean mouth" test model was used comparing a commercial dry diet and a commercial dry diet plus one dental chew per day. The dental chew tested was representative of a retail canine dental chew. The test dental chew was a green-colored dental dog chew with a flexible texture that can be readily chewed by dogs. They are made with a knuckle bone shape on one end and a toothbrush shape on the other end. Sixty adult dogs were allocated in either control or test groups based on plaque stratification and studied for 28-days. The test group (30 dogs) received a dry diet and 1 dental chew each day. The control group (30 dogs) received the same dry diet only. At the end of the study, measurements of plaque and calculus accumulation and evaluations of oral malodor and gingival heath were performed. Adding a dental chew to the diet resulted in statistically significant reductions in plaque and calculus accumulation, and oral malodor while improving gingival indices.

  18. KHAT METAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is a routine scheduled observation and is the primary observation code used in the United States to satisfy requirements for reporting surface meteorological...

  19. UNFOLDED REGULAR AND SEMI-REGULAR POLYHEDRA

    Directory of Open Access Journals (Sweden)

    IONIŢĂ Elena

    2015-06-01

    Full Text Available This paper proposes a presentation unfolding regular and semi-regular polyhedra. Regular polyhedra are convex polyhedra whose faces are regular and equal polygons, with the same number of sides, and whose polyhedral angles are also regular and equal. Semi-regular polyhedra are convex polyhedra with regular polygon faces, several types and equal solid angles of the same type. A net of a polyhedron is a collection of edges in the plane which are the unfolded edges of the solid. Modeling and unfolding Platonic and Arhimediene polyhedra will be using 3dsMAX program. This paper is intended as an example of descriptive geometry applications.

  20. Comparison of physical chewing measures to consumer typed Mouth Behavior.

    Science.gov (United States)

    Wilson, Arran; Jeltema, Melissa; Morgenstern, Marco P; Motoi, Lidia; Kim, Esther; Hedderley, Duncan

    2018-02-15

    The purpose of this study was to investigate the hypotheses that when presented with foods that could be chewed in different ways, (1) are participants jaw movements and chewing sequence measures correlated with Mouth Behavior (MB) group, as measured by the JBMB typing tool? (2) can MB group membership can be predicted from jaw movement and chewing sequence measures? One hundred subjects (69 female and 31 male, mean age 27 ± 7.7 years) were given four different foods (Mentos, Walkers, Cheetos Puffs, Twix) and video recordings of their jaw movements made. Twenty-nine parameters were calculated on each chewing sequence with 27 also calculated for the first half and second half of chewing sequence. Subjects were assigned to a MB group using the JBMB typing tool which gives four MB groups ("Chewers," "Crunchers," "Smooshers," and "Suckers"). The differences between individual chewing parameters and MB group were assessed with analysis of variance which showed only small differences in average chewing parameters between the MB groups. By using discriminant analysis, it was possible to partially discriminate between MB groups based on changes in their chewing parameters between foods with different material properties and stages of the chewing. A 19-variable model correctly predicted 68% of the subjects' membership of a MB group. This partially confirms our first hypothesis that when presented with foods that could be chewed in different ways participants will use a chewing sequence and jaw movements that correlate with their MB as measured by the JBMB typing tool. The way consumers chew their food has an impact on their texture perception of that food. While there is a wide range of chewing behaviors between consumers, they can be grouped into broad categories to better target both product design and product testing by sensory panel. In this study, consumers who were grouped on their texture preference (MB group) had jaw movements, when chewing a range of foods, which

  1. Chewing rates among domestic dog breeds

    Science.gov (United States)

    Gerstner, Geoffrey E.; Cooper, Meghan; Helvie, Peter

    2010-01-01

    The mammalian masticatory rhythm is produced by a brainstem timing network. The rhythm is relatively fixed within individual animals but scales allometrically with body mass (Mb) across species. It has been hypothesized that sensory feedback and feed-forward adjust the rhythm to match the jaw's natural resonance frequency, with allometric scaling being an observable consequence. However, studies performed with adult animals show that the rhythm is not affected by jaw mass manipulations, indicating that either developmental or evolutionary mechanisms are required for allometry to become manifest. The present study was performed to tease out the relative effects of development versus natural selection on chewing rate allometry. Thirty-one dog breeds and 31 mass-matched non-domestic mammalian species with a range in Mb from ∼2 kg to 50 kg were studied. Results demonstrated that the chewing rhythm did not scale with Mb among dog breeds (R=0.299, P>0.10) or with jaw length (Lj) (R=0.328, P>0.05). However, there was a significant relationship between the chewing rhythm and Mb among the non-domestic mammals (R=0.634, Pgeneration but they do not explain the 1/3rd to 1/4th allometric scaling observed among adult mammals. The rhythm of the timing network is either adjusted to the physical parameters of the jaw system during early development only, is genetically determined independently of the jaw system or is uniquely hard-wired among dogs and laboratory rodents. PMID:20543125

  2. The sweet lung: Chewing gummi bear aspiration.

    Science.gov (United States)

    Tavladaki, Theonimfi; Fitrolaki, Michaela-Diana; Spanaki, Anna-Maria; Ilia, Staurula; Geromarkaki, Elissabet; Briassoulis, George

    2012-07-01

    Inhalation of foreign bodies, a leading cause of accidental death, is most common in preschool children. In this article we report our experience with a 5-year-old Greek girl who presented with a 24-hour history of sore throat, chest pain, and shortness of breath. Emergency bronchoscopy was performed and multiple small chewing gummi bear (HARIBO) particles impacted in the orifices of the right main bronchus and right lobar and segmentalinic bronchi were successfully removed and aspirated. Aspiration of gummi bears, which is for the first time reported, may cause a silent choking episode leading to life-threatening bronchi obstruction at multiple sites, even in children older than 4 years.

  3. Betel Quid Chewing, Personality and Mood: Betel Quid Chewing Associated with Low Extraversion and Negative Mood.

    Science.gov (United States)

    Yen, Hsin-Yi; Chen, Ping-Ho; Ko, Ying-Chin; Chiang, Shih-Kuang; Chang, Yevvon Yi-Chi; Shiah, Yung-Jong

    2018-02-08

    Betel quid (BQ), chewed by about 600 million people worldwide, is one of the most widely used addictive substances. Little is known about psychological factors in BQ chewers. The present study was the first attempt to explore the relationships between BQ chewing, personality, and mood. A survey was conducted with a purposive sample to assess BQ chewing habits in four subgroups: BQ-only users, BQ users who smoke and/or drink, smokers and/or drinkers only, and substance nonusers. A total of 494 participants were recruited from the civilian, non-institutionalized population in Taiwan. Habitual consumption of BQ, smoking and drinking; socio-demographic variables; extraversion; and mood (tension, depression, anger, vigor, fatigue, confusion, and self-esteem). All BQ chewers were evaluated on BQ dependence domains using DSM IV and ICD-10 criteria. The 6-month BQ dependency rate among BQ chewers, defined by either DSM-IV or ICD-10 criteria, ranged from 42.9 to 45.6%. BQ-only users had significantly lower scores on extraversion than substance nonusers. BQ-only users had statistically significant higher scores on confusion and total mood than substance nonusers. BQ-only users had significantly higher scores on fatigue, anger, tension, and depression, than substance nonusers, BQ users who smoke and/or drink, and smokers and/or drinkers only. The number of BQ dependence domains correlated significantly negatively with total mood scores. Conclusions/Importance: The results supported the two hypotheses: (a) BQ chewing is associated with low extraversion; and (b) BQ chewing is related to negative mood.

  4. Automatic identification of temporal sequences in chewing sounds

    NARCIS (Netherlands)

    Amft, O.D.; Kusserow, M.; Tröster, G.

    2007-01-01

    Chewing is an essential part of food intake. The analysis and detection of food patterns is an important component of an automatic dietary monitoring system. However chewing is a time-variable process depending on food properties. We present an automated methodology to extract sub-sequences of

  5. Average chewing pattern improvements following Disclusion Time reduction.

    Science.gov (United States)

    Kerstein, Robert B; Radke, John

    2017-05-01

    Studies involving electrognathographic (EGN) recordings of chewing improvements obtained following occlusal adjustment therapy are rare, as most studies lack 'chewing' within the research. The objectives of this study were to determine if reducing long Disclusion Time to short Disclusion Time with the immediate complete anterior guidance development (ICAGD) coronoplasty in symptomatic subjects altered their average chewing pattern (ACP) and their muscle function. Twenty-nine muscularly symptomatic subjects underwent simultaneous EMG and EGN recordings of right and left gum chewing, before and after the ICAGD coronoplasty. Statistical differences in the mean Disclusion Time, the mean muscle contraction cycle, and the mean ACP resultant from ICAGD underwent the Student's paired t-test (α = 0.05). Disclusion Time reductions from ICAGD were significant (2.11-0.45 s. p = 0.0000). Post-ICAGD muscle changes were significant in the mean area (p = 0.000001), the peak amplitude (p = 0.00005), the time to peak contraction (p chewing position became closer to centric occlusion (p chewing velocities increased (p chewing pattern (ACP) shape, speed, consistency, muscular coordination, and vertical opening improvements can be significantly improved in muscularly dysfunctional TMD patients within one week's time of undergoing the ICAGD enameloplasty. Computer-measured and guided occlusal adjustments quickly and physiologically improved chewing, without requiring the patients to wear pre- or post-treatment appliances.

  6. Crossing symmetric solution of the Chew-Low equation

    International Nuclear Information System (INIS)

    McLeod, R.J.; Ernst, D.J.

    1982-01-01

    An N/D dispersion theory is developed which solves crossing symmetric Low equations. The method is used to generate crossing symmetric solutions to the Chew-Low model. We show why the technique originally proposed by Chew and Low was incapable of producing solutions. (orig.)

  7. Cetirizine release from cyclodextrin formulated compressed chewing gum

    DEFF Research Database (Denmark)

    Stojanov, Mladen; Larsen, Kim Lambertsen

    2012-01-01

    release patterns, but with variations in the total amount released. Chewing gum formulated with cetirizine alone, demonstrated a release of 75% after 8 min of chewing. The presence of CDs resulted in increased cetirizine release. The analysis of variance (ANOVA) demonstrated that parameters with the most...... the statistical analysis (ANOVA) demonstrated significance in the release (P

  8. Design, formulation, and evaluation of ginger medicated chewing gum

    Directory of Open Access Journals (Sweden)

    Abolfazl Aslani

    2016-01-01

    Conclusion: Ginger chewing gum comprises admissible properties to be used as a modern drug delivery system due to its advantageous results in motion sickness. It passed all the specified tests for an acceptable chewing gum. Thus, it may be successfully produced to help GI problems.

  9. Effect of betel nut chewing on the otolithic reflex system.

    Science.gov (United States)

    Lin, Chuan-Yi; Young, Yi-Ho

    2017-01-01

    This study investigated the effect of betel nut chewing on the otolithic reflex system. Seventeen healthy volunteers without any experience of chewing betel nut (fresh chewers) and 17 habitual chewers underwent vital sign measurements, ocular vestibular-evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests prior to the study. Each subject then chewed two pieces of betel nut for 2min (dosing). The same paradigm was repeated immediately, 10min, and 20min after chewing. On a different day, 10 fresh chewers masticated chewing gum as control. Fresh chewers exhibited significantly decreased response rates of oVEMP (53%) and cVEMP (71%) after dosing compared with those from the predosing period. These abnormal VEMPs returned to normal 20min after dosing. In contrast, 100% response rates of oVEMP and cVEMP were observed before and after masticating chewing gum. In habitual chewers, the response rates of oVEMP and cVEMP were 32% and 29%, respectively, 20min after dosing. Chewing betel nuts induced a transient loss of the otolithic reflexes in fresh chewers but may cause permanent loss in habitual chewers. Chewing betel nuts can cause a loss of otholitic reflex function. This creates a risk for disturbed balance and malfunction, for instance, during driving. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Relationship between chewing behavior and body weight status in fully dentate healthy adults.

    Science.gov (United States)

    Zhu, Yong; Hollis, James H

    2015-03-01

    Recent research indicates that chewing behavior may influence energy intake and energy expenditure. However, little is known about the relationship between chewing behavior and body weight status. In the present study, 64 fully dentate normal-weight or overweight/obese adults were asked to consume five portions of a test food and the number of chewing cycles, chewing duration before swallowing and chewing rate were measured. Adjusting for age and gender, normal-weight participants used a higher number of chewing cycles (p = 0.003) and a longer chewing duration (p chewing rate (p = 0.597). A statistically significant negative correlation between body mass index and the number of chewing cycles (r = -0.296, p = 0.020) and chewing duration (r = -0.354, p = 0.005) was observed. In conclusion, these results suggest that chewing behavior is associated with body weight status in fully dentate healthy adults.

  11. Effects and after-effects of chewing gum on vigilance, heart rate, EEG and mood.

    Science.gov (United States)

    Allen, Andrew P; Jacob, Tim J C; Smith, Andrew P

    2014-06-22

    Research has shown that chewing gum improves attention, although the mechanism for this effect remains unclear. This study investigated the effects and after-effects of chewing gum on vigilance, mood, heart rate and EEG. Participants completed a vigilance task four times; at baseline, with or without chewing gum, and twice post-chewing. EEG alpha and beta power at left frontal and temporal lobes, subjective mood and heart rate were assessed. Chewing gum shortened reaction time and increased the rate of hits, although hits fell during the second post-chewing task. Chewing gum heightened heart rate, but only during chewing. Gum also increased beta power at F7 and T3 immediately post-chewing, but not following the post-chewing tasks. The findings show that chewing gum affects several different indicators of alertness. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Coordinate-invariant regularization

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1987-01-01

    A general phase-space framework for coordinate-invariant regularization is given. The development is geometric, with all regularization contained in regularized DeWitt Superstructures on field deformations. Parallel development of invariant coordinate-space regularization is obtained by regularized functional integration of the momenta. As representative examples of the general formulation, the regularized general non-linear sigma model and regularized quantum gravity are discussed. copyright 1987 Academic Press, Inc

  13. Chewing Maintains Hippocampus-Dependent Cognitive Function.

    Science.gov (United States)

    Chen, Huayue; Iinuma, Mitsuo; Onozuka, Minoru; Kubo, Kin-Ya

    2015-01-01

    Mastication (chewing) is important not only for food intake, but also for preserving and promoting the general health. Recent studies have showed that mastication helps to maintain cognitive functions in the hippocampus, a central nervous system region vital for spatial memory and learning. The purpose of this paper is to review the recent progress of the association between mastication and the hippocampus-dependent cognitive function. There are multiple neural circuits connecting the masticatory organs and the hippocampus. Both animal and human studies indicated that cognitive functioning is influenced by mastication. Masticatory dysfunction is associated with the hippocampal morphological impairments and the hippocampus-dependent spatial memory deficits, especially in elderly. Mastication is an effective behavior for maintaining the hippocampus-dependent cognitive performance, which deteriorates with aging. Therefore, chewing may represent a useful approach in preserving and promoting the hippocampus-dependent cognitive function in older people. We also discussed several possible mechanisms involved in the interaction between mastication and the hippocampal neurogenesis and the future directions for this unique fascinating research.

  14. Chew and Spit (CHSP): a systematic review.

    Science.gov (United States)

    Aouad, Phillip; Hay, Phillipa; Soh, Nerissa; Touyz, Stephen

    2016-01-01

    This systematic review is an evaluation of the empirical literature relating to the disordered eating behaviour Chew and Spit (CHSP). Current theories postulate that CHSP is a symptom exhibited by individuals with recurrent binge eating and Bulimia Nervosa. The review aimed to identify and critically assess studies that have examined the distribution of CHSP behaviour, its relationship to eating disorders, its physical and psychosocial consequences and treatment. A systematic database search with broad inclusion criteria, dated to January 2016 was conducted. Data were extracted by two authors and papers appraised for quality using a modified Downs and Black Quality Index. Nine studies met the inclusion criteria. All were of clinical samples and majority (n = 7) were of low quality. The pathological action of chewing food but not swallowing was reported more often in those with restrictive type eating disorders, such as Anorexia Nervosa, than binge eating type disorders. CHSP also was reported to be an indicator of overall severity of an eating disorder and to appear more often in younger individuals. No studies of treatment were found. Conclusions were limited due to the low quality and small numbers of studies based on clinical samples only. Further research is needed to address gaps in knowledge regarding the physiological, psychological, social, socioeconomic impact and treatment for those engaging in CHSP.

  15. Effect of body posture on chewing behaviours in healthy volunteers.

    Science.gov (United States)

    Iizumi, T; Magara, J; Tsujimura, T; Inoue, M

    2017-11-01

    Mastication is essential to the eating process and forms an important part of feeding behaviour. Many factors related to the food bolus, such as bolus texture and size, are known to influence mastication. The aim of this study was to determine the effects of body posture on (i) chewing duration prior to the first swallow and (ii) patterns of mastication-related EMG activity. We asked 10 healthy adults to chew 8 g of steamed rice with barium sulphate while we recorded masseter, suprahyoid and infrahyoid muscle activity and simultaneously collected videofluorographic images. Participants chewed in either an upright or reclining position. Chewing duration, which was defined as the time from the start of mastication to the first swallow, was not different between the positions. However, the variability of chewing duration was larger in the upright versus reclining position, and the chewing duration in the reclining position was distributed around 15 s. Masseter activity gradually decreased in a time-dependent manner and was significantly larger at the early versus late stage of mastication. Suprahyoid activity was significantly larger at the early versus middle stage of mastication in the upright position only. Finally, masseter activity per second was negatively correlated with changes in chewing duration, that is, the larger the increase in chewing duration in the reclining position, the more the decrease in masseter activity per second. These results suggest that position-dependent changes in chewing behaviours, as described by chewing duration and EMG activity, may vary among participants. © 2017 John Wiley & Sons Ltd.

  16. The Epidemiology of Sleep Quality, Sleep Patterns, Consumption of Caffeinated Beverages, and Khat Use among Ethiopian College Students

    Directory of Open Access Journals (Sweden)

    Seblewengel Lemma

    2012-01-01

    Full Text Available Objective. To evaluate sleep habits, sleep patterns, and sleep quality among Ethiopian college students; and to examine associations of poor sleep quality with consumption of caffeinated beverages and other stimulants. Methods. A total of 2,230 undergraduate students completed a self-administered comprehensive questionnaire which gathered information about sleep complaints, sociodemographic and lifestyle characteristics,and theuse of caffeinated beverages and khat. We used multivariable logistic regression procedures to estimate odds ratios for the associations of poor sleep quality with sociodemographic and behavioral factors. Results. Overall 52.7% of students were classified as having poor sleep quality (51.8% among males and 56.9% among females. In adjusted multivariate analyses, caffeine consumption (OR=1.55; 95% CI: 1.25–1.92, cigarette smoking (OR=1.68; 95% CI: 1.06–2.63, and khat use (OR=1.72, 95% CI: 1.09–2.71 were all associated with increased odds of long-sleep latency (>30 minutes. Cigarette smoking (OR=1.74; 95% CI: 1.11–2.73 and khat consumption (OR=1.91; 95% CI: 1.22–3.00 were also significantly associated with poor sleep efficiency (<85%, as well as with increased use of sleep medicine. Conclusion. Findings from the present study demonstrate the high prevalence of poor sleep quality and its association with stimulant use among college students. Preventive and educational programs for students should include modules that emphasize the importance of sleep and associated risk factors.

  17. Chewing and Attention: A Positive Effect on Sustained Attention

    Science.gov (United States)

    Onozuka, Minoru

    2015-01-01

    Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We inspected the attributes of effects on attention in studies investigating the effects of chewing on attention or alertness conducted with pre-post design in healthy subjects, except elderly. We identified 151 references, 22 of which were included: 14 (64%) showed positive attributes of effects on attention, 1 (5%) showed negative attributes of effects on attention, 5 (23%) showed both positive and negative attributes of effects on attention, and 2 (9%) showed no significant attributes of effects on attention. Thus, positive attributes of effects of chewing on attention, especially on sustained attention, were shown in over half of the reports. These effects also appeared with improvement in mood and stress relief and were influenced by time-on-task effect. Further studies are needed, but chewing could be useful for modifying cognitive function. PMID:26075234

  18. Effect of complete and partial removable dentures on chewing movements.

    Science.gov (United States)

    Gonçalves, T M S V; Vilanova, L S R; Gonçalves, L M; Rodrigues Garcia, R C M

    2014-03-01

    Partial or complete edentulism impairs mastication. However, it is unclear how the chewing cycle is affected by prosthetics. We evaluated the chewing movements of patients fitted with complete (CD) or removable partial denture (RPD). A total of 29 subjects were kinesiographically evaluated during chewing of peanuts and Optocal portions in a random sequence. The subjects were divided into two groups according to prosthesis type. Group RPD was composed of 14 partially edentulous patients using a lower distal extension RPD (mean age 61 ± 8 years), and group CD contained 15 completely edentulous patients using CD (mean age 65·9 ± 7·9 years) in both jaws. Opening, closing, occlusal and masticatory cycle times, movement angle (opening and closing), maximum velocity (opening and closing), total area and chewing cycle amplitudes were evaluated. The results were subjected to anova and Tukey's HSD test at a significance level of 5%. The RPD group exhibited shorter opening and closing phases and masticatory cycle time (P chewing envelope was smaller in the CD group (P chewing cycles in any of the parameters evaluated (P > 0·05). RPD wearers use a faster chewing sequence with greater vertical and lateral jaw excursions compared with CD wearers. © 2013 John Wiley & Sons Ltd.

  19. Masticatory performance alters stress relief effect of gum chewing.

    Science.gov (United States)

    Nishigawa, Keisuke; Suzuki, Yoshitaka; Matsuka, Yoshizo

    2015-10-01

    We evaluated the effects of gum chewing on the response to psychological stress induced by a calculation task and investigated the relationship between this response and masticatory performance. Nineteen healthy adult volunteers without dental problems undertook the Uchida-Kraepelin (UK) test (30 min of reiterating additions of one-digit numbers). Before and immediately after the test, saliva samples were collected from the sublingual area of the participants. Three min after the UK test, the participants were made to chew flavorless gum for 3 min, and the final saliva samples were collected 10 min after the UK test. The experiment was performed without gum chewing on a different day. Masticatory performance was evaluated using color-changing chewing gum. Salivary CgA levels at immediately and 10 min after the UK test were compared with and without gum chewing condition. Two-way repeated measures analysis of variance revealed significant interaction between gum chewing condition and changes in CgA levels during post 10 min UK test period. A significant correlation was found between changes in CgA levels and masticatory performance in all participants. Our results indicate that gum chewing may relieve stress responses; however, high masticatory performance is required to achieve this effect. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  20. Gender differences in chewing discomfort in older South Koreans.

    Science.gov (United States)

    Kim, Y-J; Kim, C-B; Ahn, Y-H; Chung, W-G; Kim, N-H

    2015-11-01

    The purpose of this study was to identify gender differences in chewing discomfort among elderly Koreans. This study used data from 56 616 (weighted sample: 5 638 394) subjects aged over 65 years who participated in the 2011 Community Health Survey in Korea. Of them, 23 059 (weighted sample: 2 368 200, 42.0%) were men and 33 357 (weighted sample: 3 270 194, 58.0%) were women. Data were analysed using chi-square tests and hierarchical logistic regression analyses, with SPSS 20.0. Chewing discomfort was set as the dependent variable, and independent variables were divided into socio-economic factors (place of residence, age, education, monthly household income, basic living security stipend, private insurance, economic activity, living arrangements), general health factors (hypertension, diabetes) and oral health factors (tooth defects, denture use, subjective periodontal health status). A greater proportion of women (50.2%) than men (42.6%) exhibited chewing discomfort (P chewing discomfort (P chewing discomfort (P chewing discomfort than their male counterparts. The factors associated with chewing also differ by gender. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. The impact of chewing gum resistance on immediate free recall.

    Science.gov (United States)

    Rickman, Sarah; Johnson, Andrew; Miles, Christopher

    2013-08-01

    Although the facilitative effects of chewing gum on free recall have proved contentious (e.g., Tucha, Mecklinger, Maier, Hammerl, & Lange, 2004; Wilkinson, Scholey, & Wesnes, 2002), there are strong physiological grounds, for example, increased cerebral activity and blood flow following the act of mastication, to suppose facilitation. The present study manipulated resistance to mastication, that is, chewing four pellets versus one pellet of gum, with the assumption that increased resistance will accentuate cerebral activity and blood flow. Additionally, chewing rate was recorded for all participants. In a within-participants design, participants performed a series of immediate free recall tasks while chewing gum at learning (one or four pellets) and recall (one or four pellets). Increased chewing resistance was not associated with increased memory performance, despite consistent chewing rates for both the one and four pellet conditions at both learning and recall. However, a pattern of recall consistent with context-dependent memory was observed. Here, participants who chewed the equivalent number of gum pellets at both learning and recall experienced significantly superior word recall compared to those conditions where the number of gum pellets differed. ©2012 The British Psychological Society.

  2. Chewing and Attention: A Positive Effect on Sustained Attention

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Hirano

    2015-01-01

    Full Text Available Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We inspected the attributes of effects on attention in studies investigating the effects of chewing on attention or alertness conducted with pre-post design in healthy subjects, except elderly. We identified 151 references, 22 of which were included: 14 (64% showed positive attributes of effects on attention, 1 (5% showed negative attributes of effects on attention, 5 (23% showed both positive and negative attributes of effects on attention, and 2 (9% showed no significant attributes of effects on attention. Thus, positive attributes of effects of chewing on attention, especially on sustained attention, were shown in over half of the reports. These effects also appeared with improvement in mood and stress relief and were influenced by time-on-task effect. Further studies are needed, but chewing could be useful for modifying cognitive function.

  3. Chewing and attention: a positive effect on sustained attention.

    Science.gov (United States)

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

    Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We inspected the attributes of effects on attention in studies investigating the effects of chewing on attention or alertness conducted with pre-post design in healthy subjects, except elderly. We identified 151 references, 22 of which were included: 14 (64%) showed positive attributes of effects on attention, 1 (5%) showed negative attributes of effects on attention, 5 (23%) showed both positive and negative attributes of effects on attention, and 2 (9%) showed no significant attributes of effects on attention. Thus, positive attributes of effects of chewing on attention, especially on sustained attention, were shown in over half of the reports. These effects also appeared with improvement in mood and stress relief and were influenced by time-on-task effect. Further studies are needed, but chewing could be useful for modifying cognitive function.

  4. Areca (betel) nut chewing practices of adults and health behaviors of their children in the Freely Associated States, Micronesia: Findings from the Children's Healthy Living (CHL) Program.

    Science.gov (United States)

    Paulino, Yvette C; Ettienne, Reynolette; Novotny, Rachel; Wilkens, Lynne R; Shomour, Moria; Sigrah, Cecilia; Remengesau, Shelley D; Johnson, Emihner L; Alfred, Julia M; Gilmatam, Daisy F

    2017-10-01

    Chewing areca (betel) nut has been deemed carcinogenic. The practice has become a public health concern in Micronesia. The Children's Healthy Living (CHL) Program included an areca (betel) nut questionnaire in a survey of household characteristics in the Freely Associated States (FAS). This paper describes areca (betel) nut chewing practices of adults and the health behaviors of their children. A cross-section of 1200 children (2-8 year-olds) and their caregivers in Chuuk, Kosrae, Pohnpei, Republic of Palau, Republic of the Marshall Islands (RMI), and Yap were recruited. Socio-demographics, adult areca (betel) nut chewing practices, and other health behaviors of children and adults were assessed. Child anthropometric measurements were collected to estimate weight status. The FAS areca (betel) nut chewing prevalence was 42%, ranging from 3% (RMI) to 94% (Yap). Among chewers, 84% added tobacco, 97% added slaked lime, 85% added betel leaf, and 24% mixed the components with alcohol. Among FAS children, 95% practiced daily teeth-brushing and 53% visited the dentist annually. Compared to non-chewing households, areca (betel) nut chewing households were more likely to have very young children enrolled, more highly educated adults, and members that used tobacco and alcohol. The FAS areca (betel) nut chewing prevalence (42%) is above the world prevalence of 10-20%, with wide variability across the islands. The oral health findings in this study may inform future oral cancer prevention programs or policies. Regular monitoring of areca (betel) nut use is needed to measure the impact of such programs or policies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Xylitol chewing gum and dental caries.

    Science.gov (United States)

    Tanzer, J M

    1995-02-01

    There is an extensive peer-reviewed literature on xylitol chewing gum as it pertains to effects on tooth decay in human subjects, on human dental plaque reduction, on inhibition of dental plaque acid production, on inhibition of the growth and metabolism of the mutans group of streptococci which are the prime causative agents of tooth decay, on reduction of tooth decay in experimental animals, and on xylitol's reported contribution to the remineralisation of teeth. The literature not only supports the conclusion that xylitol is non-cariogenic but it is now strongly suggestive that xylitol is caries inhibitory, that is, anti-cariogenic in human subjects, and it supplies reasonable mechanistic explanation(s).

  6. Chewing lice (Insecta: Phthiraptera) associated with vertebrates in Mexico.

    Science.gov (United States)

    SÁnchez-Montes, Sokani; Colunga-Salas, Pablo; Álvarez-Castillo, LucÍa; GuzmÁn-Cornejo, Carmen; Montiel-Parra, Griselda

    2018-01-15

    The chewing lice (Insecta: Phthiraptera: Amblycera and Ischnocera) of Mexico have been little studied and many publications include isolated records. This paper summarizes current knowledge of chewing lice recorded from Mexico resulting from an exhaustive search of the literature published from 1866 to 2017. We found 342 louse species associated with 206 bird and 28 mammal species. As a result, we provide a checklist of the chewing lice recorded from Mexico, including a host-parasite list and their geographical distribution within the country.

  7. Gummed-up memory: Chewing gum impairs short-term recall

    OpenAIRE

    Kozlov, Michail D; Hughes, Robert W; Jones, Dylan M

    2012-01-01

    Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity...

  8. Induction of micronuclei in buccal mucosa on chewing a mixture of betel leaf, areca nut and tobacco.

    Science.gov (United States)

    Sellappa, Sudha; Balakrishnan, Mythili; Raman, Sangeetha; Palanisamy, Subashini

    2009-06-01

    Betel quid containing areca nut and chewing tobacco is used in many parts of India. In this study we evaluated the micronuclei (MN) in buccal mucosa of healthy individuals from southern India, who were regularly chewing a mixture of betel leaf, areca nut and tobacco. A total of 44 subjects were examined. The study population included 15 chewers, 14 chewers with smoking habit and 15 controls with the mean age of 38.57 +/- 0.54, 34.50 +/- 0.95, and 33.28 +/- 0.89 years, respectively. The mean percentage of MN was 1.90 +/- 1.03 in chewers, 2.00 +/-1.12 in chewers with smoking habits and 0.81 +/- 0.66 in controls. There was no significant difference between the mean percentages of the two experimental groups. It can be concluded that a mixture of betel leaf, areca nut, and tobacco is unsafe for oral health.

  9. Pressure production in oral vestibule during gum chewing.

    Science.gov (United States)

    Nishiura, M; Ono, T; Yoshinaka, M; Fujiwara, S; Yoshinaka, M; Maeda, Y

    2015-12-01

    The aim of this study was to record oral vestibule pressure (OVP) by the lip and cheek contraction during gum chewing, to examine the characteristics of these pressures and coordination between the OVP and jaw movement. The subjects were eight healthy adult men (mean age of 29·3 ± 3·3 years). An experimental plate that incorporated four pressure sensors on the midline of the upper jaw (Ch. 1), upper right canine (Ch. 2), upper right first molar (Ch. 3) and upper left first molar (Ch. 4) was used for measuring OVP. The right masseter electromyogram (EMG) was recorded simultaneously. Subjects chewed gum on the right side 20 times, and eight consecutive strokes were used for the analysis of the sequential order, maximal magnitude and duration of each OVP. Onset of OVP was observed at the molar on the non-chewing side (Ch. 4) before chewing side (Ch. 3), and offset was largely simultaneous at each site. On the chewing side (Chs. 1-3), OVP onset during the interval of EMG activity reached to the peak around the end of interval and offset in the duration of EMG activity. The maximal pressure was significantly larger at Chs. 1-3 than at Ch. 4, but no significant differences were observed in duration of pressure among each site. These results suggest that OVP is coordinated with jaw movement during gum chewing, and larger pressure is produced on the chewing side than on the non-chewing side. Our findings are quantitative indices for the evaluation of lip and cheek function during mastication. © 2015 John Wiley & Sons Ltd.

  10. Design, formulation and evaluation of nicotine chewing gum

    OpenAIRE

    Abolfazl Aslani; Sahar Rafiei

    2012-01-01

    Background: Nicotine replacement therapy (NRT) can help smokers to quit smoking. Nicotine chewing gum has attracted the attention from pharmaceutical industries to offer it to consumers as an easily accessible NRT product. However, the bitter taste of such gums may compromise their acceptability by patients. This study was, therefore, designed to develop 2 and 4 mg nicotine chewing gums of pleasant taste, which satisfy the consumers the most. Materials and Methods: Nicotine, sugar, liquid...

  11. Attention Inhibition Training Can Reduce Betel-Nut Chewing Time

    Directory of Open Access Journals (Sweden)

    Ming-Chou Ho

    2011-05-01

    Full Text Available Betel nut (or areca is the fourth most commonly used drug worldwide after tobacco, alcohol, and caffeine. Many chemical ingredients of betel nut are carcinogenic. We examined whether the manipulation of attentional inhibition toward the areca-related stimuli could affect betel-nut chewing time. Three matched groups of habitual chewers were recruited: inhibit-areca, inhibit-non-areca, and control. This study consisted of a Go/No-Go task for inhibition training, followed by a taste test for observing chewing behavior. The Go/No-Go task constituted three phases (pretest, training and posttest. In the taste test, the habitual chewers were asked to rate the flavors of one betel nut and one gum. The purpose (blind to the chewers of this taste test was to observe whether their picking order and chewing time were affected by experimental manipulation. Results from the Go/No-Go task showed successful training. Further, the training groups (the inhibit-areca and inhibit-non-areca groups showed a significant reduction in betel nut chewing time, in comparison to the control group. Since both training groups showed reduced chewing time, the inhibition training may affect general control ability, in regardless of the stimulus (areca or not to be inhibited. Reduced chewing time is important for reducing areca-related diseases.

  12. Gummed-up memory: chewing gum impairs short-term recall.

    Science.gov (United States)

    Kozlov, Michail D; Hughes, Robert W; Jones, Dylan M

    2012-01-01

    Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity. Experiment 3 demonstrated that manual tapping produces a similar pattern of impairment to that of chewing gum. These results clearly qualify the assertion that chewing gum improves short-term memory. They also pose a problem for short-term memory theories asserting that forgetting is based on domain-specific interference given that chewing does not interfere with verbal memory any more than tapping. It is suggested that tapping and chewing reduce the general capacity to process sequences.

  13. Chew on this: No support for facilitating effects of gum on spatial task performance.

    Science.gov (United States)

    Nader, Ingo W; Gittler, Georg; Waldherr, Karin; Pietschnig, Jakob

    2010-09-01

    To determine whether chewing of gum facilitates spatial task performance in healthy participants, two behavioral experiments were performed. In the first experiment, spatial task performance of 349 men and women preceding and after treatment administration (saccharated chewing gum, sugar-free chewing gum, no chewing gum) was assessed using effect modeling by means of Item Response Theory. In the second experiment, another 100 participants were either administered sugar-free chewing gum or no chewing gum during spatial task performance. Effects of gum in the second study were assessed by standard means of data analysis. Results indicated no significant effects of either chewing gum or sugar on spatial task performance in either experiment. Our findings are consistent with recent studies investigating the influences of chewing gum on various memory functions, extending them by another measure of cognitive ability. Thus, further doubt is cast on enhancing effects of chewing gum on cognitive task performance. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Effect of chewing speed on the detection of a foreign object in food.

    Science.gov (United States)

    Paphangkorakit, J; Ladsena, V; Rukyuttithamkul, T; Khamtad, T

    2016-03-01

    Accidentally biting hard on a piece of hard foreign object in food is among the causes of tooth fracturing and could be associated with oral sensibility. This study has investigated the effect of chewing speed on the ability to detect a foreign object in food in human. Fourteen healthy subjects were asked to randomly chew one of 10 cooked rice balls, five of which containing a foreign object made from a tiny uncooked rice grain, until they detected the rice grain. Each subject chewed the test foods both at 50 (slow) and 100 (fast) chews min(-1). The accuracy of detection and the number of chews before detection (CBD) were recorded and compared between the two chewing speeds using paired t-tests. The results showed that almost all subjects detected the foreign object by biting. The accuracy of detection was more than 90% and not significantly different between slow and fast chewing but the mean CBD in slow chewing (11·7 ± 1·3 chews) was significantly different from that in fast chewing (20·7 ± 1·9 chews; P chews before a foreign object in food could be detected and was, presumably, more effective in detecting the object compared to fast chewers. If each chew bears equal probability of teeth encountering the foreign object, slow chewing might also reduce the chance of accidentally biting hard on the foreign object and fracturing the tooth. © 2015 John Wiley & Sons Ltd.

  15. Near-infrared spectroscopic study on the effects of chewing on short-term memory.

    Science.gov (United States)

    Wada, Mayumi; Hoshi, Yoko; Iguchi, Yoshinobu; Kida, Ikuhiro

    2011-12-01

    Using near-infrared spectroscopy, we examined whether chewing gum improves performance in a short-term memory task - immediate recall of random eight-digit numbers - by assessing cerebral hemodynamic response in the prefrontal cortex. We found that the oxyhemoglobin concentration during and after chewing gum was higher than that before chewing; further, the concentration increased during the task, and this increase was reduced with chewing, although non-significantly. Chewing did not improve task performance. Therefore, chewing-induced hemodynamic responses were unrelated to the performance in short-term memory tasks. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. The role of time on task performance in modifying the effects of gum chewing on attention.

    Science.gov (United States)

    Tucha, Lara; Simpson, William

    2011-04-01

    Recent research examined the effects of chewing gum on attention and reported a significant interaction of gum chewing with time. Using a crossover within-subject design, the present study examined the effect of gum chewing on sustained attention in healthy adults over a period of 30 min. The results revealed a significant main effect of time and a significant interaction between gum chewing and time. The findings suggest that gum chewing differentially affects attention performance. While gum chewing has detrimental effects on sustained attention in earlier stages of the task, beneficial effects on sustained attention were observed at later stages. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Palauans who chew betel nut: social impact of oral disease.

    Science.gov (United States)

    Quinn Griffin, M T; Mott, M; Burrell, P M; Fitzpatrick, J J

    2014-03-01

    Chewing betel nut is a tradition extending from Southeast Asia to the Pacific. Globally, betel nut is the fourth main psychotropic substance containing a stimulant, arecoline, that has a similar effect to nicotine. In Palau, there is broad acceptance of betel nut chewing. One of the largest immigrant groups in Hawaii is the Palauans. Chewing betel nut has significant social implications that make it difficult for those who engage in this practice to separate potential oral disease from the social importance. However, little is known about the social impact of oral disease from chewing betel nut on Palauans in Hawaii. The study aimed to describe the perceptions of betel-chewing Palauans in Hawaii regarding betel nut and to determine the social impact of oral disease among these individuals. Descriptive study conducted on the island of Oahu, Hawaii with 30 adult Palauans. Data were collected using the Oral Health Impact Profile-14 to measure perceptions of social impact of oral disease on well-being. Demographic and general health information was collected. Participants perceived little negative social impact of oral disease on well-being. Families, peers and society exert a strong influence on the decision to chew betel nut, a known carcinogen. Participants in this study showed little concern on the impact of betel nut chewing on their oral health. They continue the habit in spite of the awareness of potential for oral disease. Nurses face challenges in educating Palauans about the negative aspects of betel nut, particularly those related to oral health especially when they do not perceive problems. Nurses must be involved in the development of health policies to design and implement strategies to promote behavioural change, and to ensure clinical services that are culturally sensitive to betel nut chewers. © 2014 International Council of Nurses.

  18. Distance-regular graphs

    NARCIS (Netherlands)

    van Dam, Edwin R.; Koolen, Jack H.; Tanaka, Hajime

    2016-01-01

    This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN'[Brouwer, A.E., Cohen, A.M., Neumaier,

  19. LL-regular grammars

    NARCIS (Netherlands)

    Nijholt, Antinus

    1980-01-01

    Culik II and Cogen introduced the class of LR-regular grammars, an extension of the LR(k) grammars. In this paper we consider an analogous extension of the LL(k) grammars called the LL-regular grammars. The relation of this class of grammars to other classes of grammars will be shown. Any LL-regular

  20. Chewing betel quid and the risk of metabolic disease, cardiovascular disease, and all-cause mortality: a meta-analysis.

    Science.gov (United States)

    Yamada, Tomohide; Hara, Kazuo; Kadowaki, Takashi

    2013-01-01

    Betel nut (Areca nut) is the fruit of the Areca catechu tree. Approximately 700 million individuals regularly chew betel nut (or betel quid) worldwide and it is a known risk factor for oral cancer and esophageal cancer. We performed a meta-analysis to assess the influence of chewing betel quid on metabolic diseases, cardiovascular disease, and all-cause mortality. We searched Medline, Cochrane Library, Web of Science, and Science Direct for pertinent articles (including the references) published between 1951 and 2013. The adjusted relative risk (RR) and 95% confidence interval were calculated using the random effect model. Sex was used as an independent category for comparison. Of 580 potentially relevant studies, 17 studies from Asia (5 cohort studies and 12 case-control studies) covering 388,134 subjects (range: 94 to 97,244) were selected. Seven studies (N = 121,585) showed significant dose-response relationships between betel quid consumption and the risk of events. According to pooled analysis, the adjusted RR of betel quid chewers vs. non-chewers was 1.47 (PBetel quid chewing is associated with an increased risk of metabolic disease, cardiovascular disease, and all-cause mortality. Thus, in addition to preventing oral cancer, stopping betel quid use could be a valuable public health measure for metabolic diseases that are showing a rapid increase in South-East Asia and the Western Pacific.

  1. The influence of food consistency on chewing rate and muscular work.

    Science.gov (United States)

    van der Bilt, A; Abbink, J H

    2017-11-01

    Food properties influence the parameters of the masticatory process, such as jaw movement, muscle activity and chewing rate. Firm foods will require more muscle activity than softer foods. However, the influence of food hardness on chewing rate is ambiguous as both slower and higher chewing rates have been reported for harder foods. Rheological characteristics of the food, such as plasticity and elasticity, may help to explain differences in chewing rate. The aim of our study was to determine the influence of food properties on chewing rate and muscular work in five phases of a chewing sequence. Eighty-four participants chewed on five foods, which strongly differed in consistency. Chewing gum was used as a reference food. The phase in the chewing sequence had a large significant effect on cycle duration for the five foods. A significant decrease in cycle duration at the beginning of chewing was followed by an increase in later phases, leading to U-shaped curves. Food type had a small effect on the average cycle duration. However, large significant differences in cycle duration were observed between the foods at the beginning of a chewing sequence. In that phase, the firm foods were chewed much slower than the soft foods. Muscular work was significantly influenced by both chewing phase and food type. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Regular Expression Pocket Reference

    CERN Document Server

    Stubblebine, Tony

    2007-01-01

    This handy little book offers programmers a complete overview of the syntax and semantics of regular expressions that are at the heart of every text-processing application. Ideal as a quick reference, Regular Expression Pocket Reference covers the regular expression APIs for Perl 5.8, Ruby (including some upcoming 1.9 features), Java, PHP, .NET and C#, Python, vi, JavaScript, and the PCRE regular expression libraries. This concise and easy-to-use reference puts a very powerful tool for manipulating text and data right at your fingertips. Composed of a mixture of symbols and text, regular exp

  3. Chewing Duration Time Of Various Food Textures In Young Adults

    Directory of Open Access Journals (Sweden)

    Raísa Coutinho Vitcel

    2017-02-01

    Full Text Available OBJECTIVE: To obtain reference values of chewing time of several food textures in young adults. METHOD: descriptive study with a quantitative approach that was developed in a clinical reference, being the population composed of 40 young adults between 18-30 years of age, of both genres. As exclusion criteria: those with neuromuscular and / or degenerative diseases or consequences thereof, as well as subjects who were making use of any orthodontic / orthopedic resource. We conducted a dental evaluation, followed by a clinical assessment. One at a time, the following foods were offered: French bread, wafer biscuit, roasted cashews, for voluntary chewing.  To measure the food chewing time, we used a stopwatch, and this collection procedure was filmed. Data analysis was performed by means of the SPSS statistics 20.0 (IBM® program. RESULTS: There was a statistically significant difference (p < 0.05 between the medians of chewing time of French bread, wafer biscuit and cashew nuts, which were 33.0s (interquartile amplitude 29.0 - 40.0, 10.0s (interquartile amplitude 8.25-12.0 and 18.5s (interquartile amplitude 15.0-23.75, respectively. CONCLUSION: The texture of foods influences the length of mastication. The more rigid is the food, the more cycles and mandibular movements, and therefore the longer the duration of chewing.

  4. Impact of removable partial denture prosthesis on chewing efficiency

    Science.gov (United States)

    BESSADET, Marion; NICOLAS, Emmanuel; SOCHAT, Marine; HENNEQUIN, Martine; VEYRUNE, Jean-Luc

    2013-01-01

    Removable partial denture prostheses are still being used for anatomic, medical and economic reasons. However, the impact on chewing parameters is poorly described. Objectives The objective of this study was to estimate the impact of removable partial denture prosthesis on masticatory parameters. Material and Methods Nineteen removable partial denture prosthesis (RPDP) wearers participated in the study. Among them, 10 subjects were Kennedy Class III partially edentulous and 9 with posterior edentulism (Class I). All presented a complete and full dentate opposing arch. The subjects chewed samples of carrots and peanuts with and without their prosthesis. The granulometry of the expectorated boluses from carrot and peanuts was characterized by median particle size (D50), determined at the natural point of swallowing. Number of chewing cycles (CC), chewing time (CT) and chewing frequency (CF=CC/CT) were video recorded. Results With RPDP, the mean D50 values for carrot and peanuts were lower [Repeated Model Procedures (RMP), F=15, p<0.001] regardless of the type of Kennedy Class. For each food, mean CC, CT and CF values recorded decreased (RMP, F=18, F=9, and F=20 respectively, p<0.01). With or without RPD, the boluses' granulometry values were above the masticatory normative index (MNI) determined as 4,000 µm. Conclusion RPDP rehabilitation improves the ability to reduce the bolus particle size, but does not reestablish fully the masticatory function. Clinical relevance This study encourages the clinical improvement of oral rehabilitation procedure. PMID:24212983

  5. The effect of chewing on oral glucoraphanin hydrolysis in raw and steamed broccoli

    NARCIS (Netherlands)

    Sarvan, Irmela; Klauw, van der Michelle; Oliviero, Teresa; Dekker, Matthijs; Verkerk, Ruud

    2018-01-01

    Chewing disrupts broccoli cells, and myrosinase can effectively hydrolyze the glucosinolate glucoraphanin into the biological active sulforaphane. The influence of chewing time and steaming time on glucoraphanin hydrolysis as well as sulforaphane and sulforaphane nitrile formation in broccoli was

  6. Evidence against memorial facilitation and context-dependent memory effects through the chewing of gum

    OpenAIRE

    Johnson, A.J.; Miles, C.

    2007-01-01

    The experiment examined the prediction that chewing gum at learning and/or recall facilitated subsequent word recall. Chewing gum at learning significantly impaired recall, indicating that the chewing of gum has a detrimental impact upon initial word encoding. In addition, a context-dependent memory effect was reported for those participants who both learned and recalled in the absence of gum, however a context dependent effect was not found with chewing gum. The findings contradict previous ...

  7. Evidence against memorial facilitation and context-dependent memory effects through the chewing of gum.

    Science.gov (United States)

    Johnson, Andrew J; Miles, Christopher

    2007-05-01

    The experiment examined the prediction that chewing gum at learning and/or recall facilitated subsequent word recall. Chewing gum at learning significantly impaired recall, indicating that the chewing of gum has a detrimental impact upon initial word encoding. In addition, a context-dependent memory effect was reported for those participants who both learned and recalled in the absence of gum; however, a context-dependent effect was not found with chewing gum. The findings contradict previous research.

  8. Betel nut chewing associated with increased risk of arterial stiffness.

    Science.gov (United States)

    Wei, Yu-Ting; Chou, Yu-Tsung; Yang, Yi-Ching; Chou, Chieh-Ying; Lu, Feng-Hwa; Chang, Chih-Jen; Wu, Jin-Shang

    2017-11-01

    Betel nut chewing is associated with certain cardiovascular outcomes. Subclinical atherosclerosis may be one link between betel nut chewing and cardiovascular risk. Few studies have examined the association between chewing betel nut and arterial stiffness. The aim of this study was thus to determine the relationship between betel nut chewing and arterial stiffness in a Taiwanese population. We enrolled 7540 eligible subjects in National Cheng Kung University Hospital from October 2006 to August 2009. The exclusion criteria included history of cerebrovascular events, coronary artery disease, and taking lipid-lowering drugs, antihypertensives, and hypoglycemic agents. Increased arterial stiffness was defined as brachial-ankle pulse wave velocity (baPWV) ≥1400cm/s. According to their habit of betel nut use, the subjects were categorized into non-, ex-, and current chewers. The prevalence of increased arterial stiffness was 32.7, 43.3, and 43.2% in non-, ex- and current chewers, respectively (p=0.011). Multiple logistic regression analysis revealed that ex-chewers (odds ratio [OR] 1.69, 95% confidence interval (CI)=1.08-2.65) and current chewers (OR 2.29, 95% CI=1.05-4.99) had elevated risks of increased arterial stiffness after adjustment for co-variables. Both ex- and current betel nut chewing were associated with a higher risk of increased arterial stiffness. Stopping betel nut chewing may thus potentially be beneficial to reduce cardiovascular risk, based on the principals of preventive medicine. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Effects of caffeine in chewing gum on mood and attention.

    Science.gov (United States)

    Smith, Andrew

    2009-04-01

    Recent research has shown that even small doses (attention tasks. Previous studies have given the caffeine in a variety of beverages or in capsules and it was of interest to see whether similar effects could be observed when the caffeine was given in gum. In addition, chewing gum has been shown to have behavioural effects and the present study extended our knowledge of this topic. To compare the effects of caffeinated gum (40 mg), placebo gum and no gum conditions on mood and attention. A double blind placebo controlled study was conducted with volunteers being randomly assigned to one of the three conditions. Baseline measures of mood and attention were taken prior to chewing and a test session was then conducted. One hundred and eighteen young adults participated in the study. Caffeinated gum was associated with a more positive mood and better performance on tasks requiring sustained attention. The caffeine improved the speed of encoding of new information which is consistent with previous findings. Chewing placebo gum was also found to be associated with more positive mood, both shortly after chewing and at the end of the study. The implications of the present study are that chewing caffeinated gum has been shown to improve performance efficiency and mood by its alerting and energising effects. The profile of caffeine effects is what one would predict from the existing caffeine literature and such effects may be extremely beneficial in real-life situations. Prior chewing of placebo gum was associated with a more positive mood and this also confirms previous findings.

  10. Association between chewing-stimulated salivary flow under the effects of atropine and mixing ability assessed using a color-changeable chewing gum.

    Science.gov (United States)

    Kubota, Chieko; Kanazawa, Manabu; Hama, Yohei; Komagamine, Yuriko; Minakuchi, Shunsuke

    2017-10-01

    To assess the time course of chewing-stimulated salivary flow after oral atropine administration, and determine the association between chewing-stimulated salivary flow and mixing ability using color-changeable chewing gum in dentate adults. Ten healthy dentate adults were administered 1mg oral atropine to induce mouth dryness. The subjects' chewing-stimulated salivary flow was assessed using the Saxon test. They were then asked to rinse their mouth with tap water for 15s, and to chew on color-changeable chewing gum for 60s at a constant rate of 60 cycles per min. This procedure was performed before, and at 10-min intervals for up to 120min after the atropine administration. The experiment was repeated after 1 week. Steel's test was used to compare the chewing-stimulated salivary flow rates at each time point after atropine administration with the baseline value. The effect of the stimulated salivary flow rates on the degree of color change was analyzed using linear mixed effects models, with the stimulated salivary flow rates as fixed factors and subjects as the random factor. Chewing-stimulated salivary flow showed a significant decrease from 50 to 120min after oral atropine administration (Pchewing-stimulated salivary flow had a significant effect on the color change of the color-changeable chewing gum (Pchewing gum and chewing-stimulated salivary flow in dentate subjects. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  11. Taking actions to quit chewing betel nuts and starting a new life: taxi drivers' successful experiences of quitting betel nut chewing.

    Science.gov (United States)

    Yang, Tsui-Yun; Lin, Hung-Ru

    2017-04-01

    To understand taxi drivers' successful experiences of quitting betel nut chewing. Previous studies verified that betel nut chewing significantly increases the risk of oral cancer. In Taiwan, taxi drivers work for approximately 10-13 hours per day, and 31·7-80% of them choose to chew betel nuts for their invigorating qualities, which enable them to work more hours and receive more income. A qualitative research design was used. This study used the grounded theory method with purposive sampling to perform in-depth interviews with male taxi drivers who had successfully quit betel nut chewing for more than six months. The interviewed participants were 25 taxi drivers aged 45-67 who had chewed betel nuts for an average of 30·9 years. A constant comparative analysis of the 25 interviews revealed six categories, namely the first experience of chewing betel nuts, a part of work and life, perceiving the impact of betel nuts, trying to change, acting to quit betel nut chewing and starting a new life. During the cessation process, taxi drivers tended to be affected by their addiction to chewing betel nuts and the temptation of friends' invitations to chew betel nuts. However, their recognition of the physical effects of betel nut chewing and their sense of responsibility and commitment to family were the critical factors affecting their determination to quit betel nut chewing. Their willpower to not to chew betel nuts and the source of their motivation to exercise self-control also contributed to their success. Healthcare personnel should understand the experiences and perceptions of betel nut chewers, strengthen their understanding of the effects of betel nut chewing on physical health during the cessation period and support their self-efficacy and quitting behaviours with the assistance of significant others. © 2016 John Wiley & Sons Ltd.

  12. Chewing gum and lozenges as delivery systems for noscapine

    DEFF Research Database (Denmark)

    Norgaard Jensen, L.; Christrup, Lona Louring; Menger, N.

    1991-01-01

    Chewing gum and lozenges were evaluated as delivery systems for noscapine with the aim of developing improved antitussive preparations. The formulations studied were prepared with both the water-soluble hydrochloride salt of noscapine and with the poorly soluble embonate salt and noscapine free...... base. The release characteristics of the preparations were evaluated both in vitro and in vivo, and their taste properties examined. Only the formulations containing noscapine base were without any appreciable taste. Chewing gum containing this compound showed, however, a low level of drug release both...

  13. Areca nut chewing and systemic inflammation : evidence of a common pathway for systemic diseases

    NARCIS (Netherlands)

    Shafique, Kashif; Mirza, Saira Saeed; Vart, Priya; Memon, Abdul Rauf; Arain, Moin Islam; Tareen, Muhammad Farooq; Haq, Zia Ul

    2012-01-01

    Background: Areca nut, the seed of fruit of an oriental palm, known as Areca catechu, is commonly chewed in many countries. Diabetes, hypertension, cardiovascular diseases, oropharyngeal and oesophageal cancers have been associated with areca nut chewing and the mechanism by which areca nut chewing

  14. The influence of food consistency on chewing rate and muscular work

    NARCIS (Netherlands)

    van der Bilt, A.; Abbink, J. H.

    2017-01-01

    Food properties influence the parameters of the masticatory process, such as jaw movement, muscle activity and chewing rate. Firm foods will require more muscle activity than softer foods. However, the influence of food hardness on chewing rate is ambiguous as both slower and higher chewing rates

  15. The role of time on task performance in modifying the effects of gum chewing on attention

    NARCIS (Netherlands)

    Tucha, Lara; Simpson, William

    Recent research examined the effects of chewing gum on attention and reported a significant interaction of gum chewing with time. Using a crossover within-subject design, the present study examined the effect of gum chewing on sustained attention in healthy adults over a period of 30 min. The

  16. Regularization by External Variables

    DEFF Research Database (Denmark)

    Bossolini, Elena; Edwards, R.; Glendinning, P. A.

    2016-01-01

    Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind of regula......Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind...

  17. Regular expressions cookbook

    CERN Document Server

    Goyvaerts, Jan

    2009-01-01

    This cookbook provides more than 100 recipes to help you crunch data and manipulate text with regular expressions. Every programmer can find uses for regular expressions, but their power doesn't come worry-free. Even seasoned users often suffer from poor performance, false positives, false negatives, or perplexing bugs. Regular Expressions Cookbook offers step-by-step instructions for some of the most common tasks involving this tool, with recipes for C#, Java, JavaScript, Perl, PHP, Python, Ruby, and VB.NET. With this book, you will: Understand the basics of regular expressions through a

  18. Regularities of Multifractal Measures

    Indian Academy of Sciences (India)

    First, we prove the decomposition theorem for the regularities of multifractal Hausdorff measure and packing measure in R R d . This decomposition theorem enables us to split a set into regular and irregular parts, so that we can analyze each separately, and recombine them without affecting density properties. Next, we ...

  19. Stochastic analytic regularization

    International Nuclear Information System (INIS)

    Alfaro, J.

    1984-07-01

    Stochastic regularization is reexamined, pointing out a restriction on its use due to a new type of divergence which is not present in the unregulated theory. Furthermore, we introduce a new form of stochastic regularization which permits the use of a minimal subtraction scheme to define the renormalized Green functions. (author)

  20. Agave Chewing and Dental Wear: Evidence from Quids.

    Directory of Open Access Journals (Sweden)

    Emily E Hammerl

    Full Text Available Agave quid chewing is examined as a potential contributing behavior to hunter-gatherer dental wear. It has previously been hypothesized that the contribution of Agave quid chewing to dental wear would be observed in communities wherever phytolith-rich desert succulents were part of subsistence. Previous analysis of coprolites from a prehistoric agricultural site, La Cueva de los Muertos Chiquitos in Durango, Mexico, showed that Agave was a consistent part of a diverse diet. Therefore, quids recovered at this site ought to be useful materials to test the hypothesis that dental wear was related to desert succulent consumption. The quids recovered from the site were found to be largely derived from chewing Agave. In this study, the quids were found to be especially rich in phytoliths, and analysis of dental casts made from impressions left in the quids revealed flat wear and dental attrition similar to that of Agave-reliant hunter-gatherers. Based on evidence obtained from the analysis of quids, taken in combination with results from previous studies, it is determined that Agave quid chewing was a likely contributing factor to dental wear in this population. As such, our method provides an additional avenue of dental research in areas where quids are present.

  1. Anaphe venata larva extract-induced purposeless chewing in rats ...

    African Journals Online (AJOL)

    In this study we investigated the effect of the crude aqueous and Phosphate Buffer Saline (PBS) extracts of this larva on altered spontaneous rat behavior in a novel environment particularly chewing behaviour, with a view to determine the mechanism(s) involved in these behavioural alteration. Animals were randomly ...

  2. Effect of experimental chewing on masticatory muscle pain onset

    Directory of Open Access Journals (Sweden)

    Paulo César Rodrigues Conti

    2011-02-01

    Full Text Available OBJECTIVES: To evaluate the effect of a chewing exercise on pain intensity and pressure-pain threshold in patients with myofascial pain. METHODS: Twenty-nine consecutive women diagnosed with myofascial pain (MFP according to the Research Diagnostic Criteria comprised the experimental group and 15 healthy age-matched female were used as controls. Subjects were asked to chew a gum stick for 9 min and to stay at rest for another 9 min afterwards. Pain intensity was rated on a visual analog scale (VAS every 3 min. At 0, 9 and 18 min, the pressure-pain threshold (PPT was measured bilaterally on the masseter and the anterior, medium, and posterior temporalis muscles. RESULTS: Patients with myofascial pain reported increase (76% and no change (24% on the pain intensity measured with the VAS. A reduction of the PPT at all muscular sites after the exercise and a non-significant recovery after rest were also observed. CONCLUSION: The following conclusions can be drawn: 1. there are at least two subtypes of patients with myofascial pain that respond differently to experimental chewing; 2. the chewing protocol had an adequate discriminative ability in distinguishing patients with myofascial pain from healthy controls.

  3. Elemental composition of betel nut and associated chewing materials

    International Nuclear Information System (INIS)

    Ridge, C.; Akanle, O.; Spyrou, N.M.

    2001-01-01

    Betel nut chewing (Area catechu), Whether plain or wrapped inside a betel leaf 'quid' together with other substances including tobacco, has been reported as a cause of the high incidence of oral and oesophageal cancers in Asian communities worldwide. Chewing of such substances results in the formation of nitrosamines, some of which may be diabetogenic to man. The incidence of Type 2 diabetes is particularly prevalent amongst Asian immigrants living in the UK and as part of a larger study we have analysed a number of popular betel nut based chewing materials to determine their elemental composition. Instrumental neutron activation analysis was used for determination of elemental concentrations of short-lived radionuclides. Ag, Al. Br, Ca, Cl, Cu, Dy, K, Mg, Mn, Na, Ti, and V were detected, some of which are implicated in diabetes. Concentrations of these, expect for Ag, Dy and Ti, are reported and compared with values found in betel-nut and chewing materials from Taiwan. It is indicated that for certain elements the amount ingested by betel-nut chewers may be a significant fraction of their daily dietary intake. (author)

  4. Bite weight prediction from acoustic recognition of chewing

    NARCIS (Netherlands)

    Amft, O.D.; Kusserow, M.; Tröster, G.

    2009-01-01

    Automatic dietary monitoring (ADM) offers new perspectives to reduce the self-reporting burden for participants in diet coaching programs. This paper presents an approach to predict weight of individual bites taken. We utilize a pattern recognition procedure to spot chewing cycles and food type in

  5. Effect of chewing upon disc reduction in the temporomandibular joint

    NARCIS (Netherlands)

    Kalaykova, S.; Lobbezoo, F.; Naeije, M.

    2011-01-01

    Aims: To test whether an intensive chewing exercise influences the moment of disc reduction in subjects with or without reports of intermittent locking of the jaw. Methods: This experimental study included 15 subjects with a reducing anteriorly displaced disc (ADD) and with symptoms of intermittent

  6. Relationship between meat juiciness intensity scores during chewing

    Science.gov (United States)

    The objectives were to establish relationships between sensory juiciness intensity scores during chewing. Chicken breast meat was ground, made into 90g patties, and cooked to 78C. Sensory assessment for juiciness was made by a 7-member, trained descriptive panel using a time-intensity method followe...

  7. Phytochemical screening and mineral composition of chewing sticks ...

    African Journals Online (AJOL)

    Phytochemical screening of the stems of Garcinia kola, Dennettia tripetala, Acioa barteri, Dialium guineense, Maesobotrya barteri, Mallotus oppositifolius and Psidium guajava which are commonly used as chewing sticks in southern Nigeria revealed the presence of bioactive compounds comprising saponins, tannins, ...

  8. Craving and Chewing Ice: A Sign of Anemia?

    Science.gov (United States)

    ... constantly craving and chewing ice a sign of anemia? Answers from Rajiv K. Pruthi, M.B.B.S. Possibly. Doctors use the term " ... often associated with iron deficiency, with or without anemia, although the reason is unclear. At least one ...

  9. Chewing ability of the long-term hospitalized elderly.

    Science.gov (United States)

    Peltola, Petteri; Vehkalahti, Miira M

    2005-01-01

    We investigated the chewing ability of 260 (25 percent men) long-term hospitalized elderly patients 60 years of age and older in Laakso hospital, Helsinki, Finland, in relation to their mastication capacity, sore mouth and degree of dependence. The subjects' (mean age 83.3 years, SD = 8.1 years) mastication capacity was determined by a specialist dentist by means of: (a) number of functioning teeth and dentures; (b) modified Eichner Index; and (c) the Eichner Score, based on the index. Based on the information given by the nursing staff, an indicator of chewing ability was created. The chewing ability was poor for 55 percent, limited for 17 percent, moderate for 14 percent and excellent for 14 percent. Excellent or moderate ability to chew was related to a subject's lesser degree of dependence (OR = 1.5; p = 0.02) and higher Eichner Score (OR = 1.3; p = 0.000). More attention should be focused on mastication capacity of the hospitalized elderly.

  10. Herbal-caffeinated chewing gum, but not bubble gum, improves aspects of memory.

    Science.gov (United States)

    Davidson, Matthew G

    2011-08-01

    Research has shown that standard chewing gum can affect aspects of both attention and memory. The present study examined the effects of Think Gum®, a caffeinated-herbal chewing gum, on both concentration and memory using a series of paper-based and online testing. Compared to standard chewing gum and a no-gum control, chewing caffeinated-herbal gum during testing improved aspects of memory, but did not affect concentration. The findings suggest that caffeinated-herbal chewing gum is an effective memory aid. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. A pilot study on community-based outpatient treatment for patients with chronic psychotic disorders in Somalia: Change in symptoms, functioning and co-morbid khat use

    Directory of Open Access Journals (Sweden)

    Odenwald Michael

    2012-07-01

    Full Text Available Abstract Background In Low and Middle Income Countries, mental health services are often poorly developed due to the lack of resources and trained personnel. In order to overcome these challenges, new ways of care have been suggested such as a focus on community-based services. In Somalia, the consumption of the natural stimulant khat is highly prevalent, aggravating mental illness. At the same time, mental health care is largely unavailable to the vast majority of the population. In a pilot project, we tested possibilities for effective measures in community-based out-patient mental health care. Methods Thirty-five male patients with chronic psychotic disorders and their carers were involved in a 10-months follow-up study. All of them abused khat. Seventeen outpatients experiencing acute psychotic episodes were recruited from the community and received an intensive six week home-based treatment package. Additionally eighteen patients with chronic psychotic disorders in remission were recruited either following hospital discharge or from the community. In a second phase of the study, both groups received community-based relapse prevention that differed in the degree of the family’s responsibility for the treatment. The treatment package was comprised of psycho-education, low-dose neuroleptic treatment, monthly home visits and counseling. The Brief Psychiatric Rating Scale (BPRS was applied three times. Additionally, we assessed functioning, khat use and other outcomes. Results Of the 35 patients enrolled in the study, 33 participated in the 10-month follow-up. Outpatients improved significantly in the first six weeks of treatment and did not differ from remitted patients at the start of the second treatment phase. In the preventive treatment phase, we find heterogeneous outcomes that diverge between symptom and functioning domains. With the exception of depressive symptoms, symptoms in all patients tended to worsen. The outpatient group had

  12. Xylitol Chewing Gums on the Market: Do They Prevent Caries?

    Science.gov (United States)

    Alanzi, Abrar; Soderling, Eva; Varghese, Anisha; Honkala, Eino

    To measure the xylitol content in sugar-free chewing gums available on the market in Gulf Cooperation Council (GCC) countries in the Middle East, in order to identify those products that can provide the recommended daily dose of xylitol for caries prevention (6-7 g). Acid production from chewing gums was also measured in vitro and in vivo. Twenty-one chewing gums containing xylitol were identified and collected from the GCC market (Kuwait, Bahrain, Qatar, Saudi Arabia, UAE and Oman). Xylitol was extracted and its concentration was analysed using a special enzymatic kit. The pH of extracts was measured during 30-min incubation with Streptococcus mutans. Changes in saliva and plaque pH were noted in four subjects after the consumption of highly concentrated xylitol gums. The xylitol content in grams was clearly mentioned only on one product's label. Twelve products stated the percentage of xylitol (3.5% to 35%). The rest did not specify the amount. The mean measured weight of one piece of gum was 1.67 ± 0.38 g. The mean measured xylitol content/piece was 0.33 ± 0.21 g. Xylitol content was 0.5 g in 5 products. None of the highly concentrated xylitol gums showed a pH drop in vitro or in vivo. One chewing gum, containing xylitol and glucose, resulted in a low pH level (xylitol chewing gums sold on the GCC market do not provide the consumers with the recommended daily dose of xylitol for caries prevention. Clear, accurate labeling is recommended.

  13. Chewing gum and context-dependent memory effects: a re-examination.

    Science.gov (United States)

    Miles, Christopher; Johnson, Andrew J

    2007-03-01

    Two experiments re-examined whether chewing spearmint gum affects initial word learning and/or immediate recall for a word list. Both experiments failed to show effects of chewing gum at learning or recall, nor did they suggest that chewing gum produces a context-dependent memory effect. This was true when extraneous contextual cues at learning and recall were minimised (Experiment 2). Together, the data are inconsistent with [Wilkinson, L., Scholey, A. & Wesnes, K. (2002). Chewing gum selectively improves aspects of memory in healthy volunteers. Appetite, 38, 235-236.] claim that chewing gum aids immediate recall of visually presented words. Our results are consistent with [Baker, J. R., Bezance, J. B., Zellaby, E. & Aggleton, J. P. (2004). Chewing gum can produce context-dependent effects upon memory. Appetite, 43, 207-210.] finding that chewing gum of itself is not a sufficient condition to provoke context-dependent learning with immediate testing.

  14. Effects of sugar-free chewing gum sweetened with xylitol or maltitol on the development of gingivitis and plaque: a randomized clinical trial.

    Science.gov (United States)

    Keukenmeester, R S; Slot, D E; Rosema, N A M; Van Loveren, C; Van der Weijden, G A

    2014-11-01

    The objective of this study was to test the effect of sugar-free chewing gum sweetened with xylitol or maltitol compared to the use of a gum base or no gum on gingivitis and plaque scores under both brushing and non-brushing circumstances. The design of the study was a four-group, double-blinded, randomized controlled study with a 3-week duration. In each group, the participants did not brush the teeth in the lower jaw designated to develop experimental gingivitis, while maintaining normal oral hygiene procedures in the upper jaw. After professional dental prophylaxis, the participants were allocated into one of four groups (xylitol, maltitol, gum base or no gum). Chewing gum was used five times a day for 10 min. 220 participants completed the study and provided evaluable data. The increase in bleeding on marginal probing (BOMP) and plaque scores (PS) in the non-brushed (lower) jaw with experimental gingivitis was significant in all groups (P xylitol and maltitol group was significantly lower. In the brushed upper jaw, no significant changes for BOMP were observed from the baseline to the end point of the study, and there were no significant differences in BOMP and PS between the groups. In circumstances where regular brushing is performed, no effect of chewing gum was observed on bleeding and plaque scores. In the absence of brushing, chewing xylitol or maltitol gum provided a significant inhibitory effect on gingivitis scores compared to chewing gum base. The difference when compared to the group not using gum was not significant. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Sparse structure regularized ranking

    KAUST Repository

    Wang, Jim Jing-Yan; Sun, Yijun; Gao, Xin

    2014-01-01

    Learning ranking scores is critical for the multimedia database retrieval problem. In this paper, we propose a novel ranking score learning algorithm by exploring the sparse structure and using it to regularize ranking scores. To explore the sparse

  16. Regular expression containment

    DEFF Research Database (Denmark)

    Henglein, Fritz; Nielsen, Lasse

    2011-01-01

    We present a new sound and complete axiomatization of regular expression containment. It consists of the conventional axiomatiza- tion of concatenation, alternation, empty set and (the singleton set containing) the empty string as an idempotent semiring, the fixed- point rule E* = 1 + E × E......* for Kleene-star, and a general coin- duction rule as the only additional rule. Our axiomatization gives rise to a natural computational inter- pretation of regular expressions as simple types that represent parse trees, and of containment proofs as coercions. This gives the axiom- atization a Curry......-Howard-style constructive interpretation: Con- tainment proofs do not only certify a language-theoretic contain- ment, but, under our computational interpretation, constructively transform a membership proof of a string in one regular expres- sion into a membership proof of the same string in another regular expression. We...

  17. Supersymmetric dimensional regularization

    International Nuclear Information System (INIS)

    Siegel, W.; Townsend, P.K.; van Nieuwenhuizen, P.

    1980-01-01

    There is a simple modification of dimension regularization which preserves supersymmetry: dimensional reduction to real D < 4, followed by analytic continuation to complex D. In terms of component fields, this means fixing the ranges of all indices on the fields (and therefore the numbers of Fermi and Bose components). For superfields, it means continuing in the dimensionality of x-space while fixing the dimensionality of theta-space. This regularization procedure allows the simple manipulation of spinor derivatives in supergraph calculations. The resulting rules are: (1) First do all algebra exactly as in D = 4; (2) Then do the momentum integrals as in ordinary dimensional regularization. This regularization procedure needs extra rules before one can say that it is consistent. Such extra rules needed for superconformal anomalies are discussed. Problems associated with renormalizability and higher order loops are also discussed

  18. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  19. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  20. Mandibular corpus bone strains during mastication in goats (Capra hircus): a comparison of ingestive and rumination chewing.

    Science.gov (United States)

    Williams, Susan H; Stover, Kristin K; Davis, Jillian S; Montuelle, Stephane J

    2011-10-01

    To compare the mechanical loading environment of the jaw in goats during ingestive and rumination chewing. Rosette strain gauges were attached to the external surface of the mandibular corpus in five goats to record bone strains during the mastication of hay and rumination. Strain magnitudes and maximum physiological strain rates during the mastication of hay are significantly higher than during rumination chewing on the working and balancing sides. Principal strain ratios and orientations are similar between the two chewing behaviours. Loading and chewing cycle duration are all longer during rumination chewing, whereas chew duty factor and variances in load and chewing cycle durations are higher during ingestive chewing. For most of the variables, differences in strain magnitudes or durations are similar at all three gauge sites, suggesting that rumination and ingestive chewing do not differentially influence bone at the three gauge sites. Despite lower strain magnitudes, the repetitive nature of rumination chewing makes it an important component of the mechanical loading environment of the selenodont artiodactyl jaw. However, similarities in principal strain orientations and ratios indicate that rumination chewing need not be considered as a unique loading behaviour influencing the biomechanics of the selenodont artiodactyl jaw. Differences in loading and chewing cycle durations during rumination and ingestion demonstrate flexibility in adult chewing frequencies. Finally, although the low within-sequence variability in chewing cycle durations supports the hypothesis that mammalian mastication is energetically efficient, chewing during rumination may not be more efficient than during ingestion. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Association of Areca Nut Chewing With Risk of Erectile Dysfunction.

    Science.gov (United States)

    Huang, Yung-Jui; Jiann, Bang-Ping

    2017-09-01

    Areca nut chewing has been shown to increase the risk of cardiovascular disease, but its association with erectile dysfunction (ED) has not been investigated. To investigate the association between areca nut chewing and risk of ED. Consecutive men at public health centers for oral malignancy screening or health checkup were invited to complete a questionnaire. The Sexual Health Inventory for Men (SHIM). Of the 2,652 respondents, 1,038 (mean age = 43.8 ± 11.1 years) were eligible for the areca nut chewing group and 1,090 non-areca nut chewers were selected as the age-matched control group. In the areca nut group, the mean duration of chewing was 13.2 ± 9.6 years, 61.7% consumed more than 10 portions per day, and 76.2% used it with betel leaf, 16.7% used it with betel inflorescence, and 7.1% used it with betel leaf and inflorescence. Smoking, alcohol drinking, obesity, hypertension, and diabetes were more predominant in areca nut chewers compared with controls. ED defined by self-report and by SHIM score was more prevalent in areca nut chewers than in controls (13.7% vs 9.8% and 48.7% vs 43.3%, respectively; P betel inflorescence was associated with a higher risk of ED (odds ratio = 2.25, 95% confidence interval = 1.55-3.28) with a dose-dependent effect, whereas using it with betel leaf was not (odds ratio = 1.00, 95% confidence interval = 0.79-1.26) after adjustment of possible confounders. Areca nut chewing with betel inflorescence was associated with an increased risk of ED. These findings warrant further studies. Huang Y-J, Jiann B-P. Association of Areca Nut Chewing With Risk of Erectile Dysfunction. Sex Med 2017;5:e163-e168. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Effectiveness of a Nutrition Education Program to Improve Children's Chewing Habits.

    Science.gov (United States)

    Sato, Nanae; Hayashi, Fumi; Yoshiike, Nobuo

    2016-01-01

    This quasi-experimental study determined whether the nutrition education program we developed to promote chewing food properly influenced children's chewing habits successfully. Four kindergarten classes in Japan (150 children, aged 5-6 years) were studied; one class received the educational program in the classroom and at home (Group A) and three classes received the program in the classroom only (Group B). The educational program was integrated into the classes' daily curriculum for five weeks. It included storytelling with large picture books, chewing consciously while eating lunch, singing a song with gestures, and greetings before and after meals (both groups). Group A also used a paper textbook and was provided information by the leaflet to encourage guardians to implement the program at home. Chewing habits before and after intervention were evaluated: (1) guardians completed seven questionnaire items related to chewing habits and chewing movement and (2) the number of chews and time spent eating the test meal were measured by a portable chewing sensor. Both approaches improved the children's chewing habits; however, no difference was found between the two groups. We concluded that this intervention could be used to improve chewing habits in young children even without active involvement of their guardians.

  3. Analysis of temporal variation in human masticatory cycles during gum chewing.

    Science.gov (United States)

    Crane, Elizabeth A; Rothman, Edward D; Childers, David; Gerstner, Geoffrey E

    2013-10-01

    The study investigated modulation of fast and slow opening (FO, SO) and closing (FC, SC) chewing cycle phases using gum-chewing sequences in humans. Twenty-two healthy adult subjects participated by chewing gum for at least 20s on the right side and at least 20s on the left side while jaw movements were tracked with a 3D motion analysis system. Jaw movement data were digitized, and chewing cycle phases were identified and analysed for all chewing cycles in a complete sequence. All four chewing cycle phase durations were more variant than total cycle durations, a result found in other non-human primates. Significant negative correlations existed between the opening phases, SO and FO, and between the closing phases, SC and FC; however, there was less consistency in terms of which phases were negatively correlated both between subjects, and between chewing sides within subjects, compared with results reported in other species. The coordination of intra-cycle phases appears to be flexible and to follow complex rules during gum-chewing in humans. Alternatively, the observed intra-cycle phase relationships could simply reflect: (1) variation in jaw kinematics due to variation in how gum was handled by the tongue on a chew-by-chew basis in our experimental design or (2) by variation due to data sampling noise and/or how phases were defined and identified. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. A comparison of chewing rate between overweight and normal BMI individuals.

    Science.gov (United States)

    White, Amy Kristin; Venn, Bernard; Lu, Louise Weiwei; Rush, Elaine; Gallo, Luigi Maria; Yong, Janet Lee Ching; Farella, Mauro

    2015-06-01

    Previous attempts to identify an 'obese eating style' have led to conflicting findings. This observational study compared the chewing features of overweight or obese young adults with those of normal range BMI. We hypothesised that chewing features are individual-specific and differ between participants of a normal BMI and high BMI. Fourteen overweight to obese participants (BMI≥25.0) were pairwise matched with 14 normal range BMI participants (18.5chewing episodes, including rate, duration, and power. Masticatory performance was assessed by a sieve test and was expressed as the percentage of particles ≤2mm after a standardised chewing test. Regardless of the meal, chewing rate was remarkably consistent among participants (ICC=0.89; 95% CI=0.79-0.94). Chewing rate did not differ between high and normal BMI participants (p>0.05), whereas chewing power was significantly higher in high BMI participants (pchewing characteristics were found between BMI groups. Participants chewed at similar rate in the natural environment (pizza) and in the laboratory (rice) setting (p>0.05). Masticatory performance did not differ significantly (p>0.05) between the high (55.9%) and normal (52.4%) BMI groups. Within the limitations of the present study, chewing characteristics appear to be individual-specific with wide variability. Overweight participants chew at a similar rate to control participants, albeit slightly stronger. Our preliminary findings need to be replicated in larger samples. Copyright © 2015. Published by Elsevier Inc.

  5. PREVALENCE AND FACTORS INFLUENCING BETEL NUT CHEWING AMONG ADULTS IN WEST INSEIN TOWNSHIP, YANGON, MYANMAR.

    Science.gov (United States)

    Myint, Su Kyaw; Narksawat, Kulaya; Sillabutra, Jutatip

    2016-09-01

    Betel nut chewing can cause precancerous oral lesions and is common in Myanmar. We conducted a cross sectional study aimed to estimate prevalence and factors influencing betel nut chewing among 420 subjects aged ≥18 years in West Insein Township, Yangon, Myanmar in order to inform preventive health programs. The mean age of the study subjects was 45(±15) years. The overall prevalence of current betel nut chewing among study subjects was 55.2%. The mean age starting betel nut chewing was 29(±13) years, and the mean duration of chewing was 15(±13) years. The reasons given by study subjects for chewing betel nut included the addictive effect to betel nut, to release tension, to get rid of boredom and to stop smoking. Sixty-two point three percent of current betel nut chewers also chewed tobacco and 24.2% also smoked cigarettes. Factors significantly associated with betel nut chewing were male gender, current alcohol consumer, having no education or finishing primary or secondary school, having a low score regarding their attitude about the health effects of betel nut chewing, and having high score on interpersonal factors by family and peer pressure. Our results show a need to better educate the public about the health effects of betel nut chewing among the study population.

  6. Effects of Betel chewing on the central and autonomic nervous systems.

    Science.gov (United States)

    Chu, N S

    2001-01-01

    Betel chewing has been claimed to produce a sense of well-being, euphoria, heightened alertness, sweating, salivation, a hot sensation in the body and increased capacity to work. Betel chewing also leads to habituation, addiction and withdrawal. However, the mechanisms underlying these effects remain poorly understood. Arecoline, the major alkaloid of Areca nut, has been extensively studied, and several effects of betel chewing are thought to be related to the actions of this parasympathomimetic constituent. However, betel chewing may produce complex reactions and interactions. In the presence of lime, arecoline and guvacoline in Areca nut are hydrolyzed into arecaidine and guvacine, respectively, which are strong inhibitors of GABA uptake. Piper betle flower or leaf contains aromatic phenolic compounds which have been found to stimulate the release of catecholamines in vitro. Thus, betel chewing may affect parasympathetic, GABAnergic and sympathetic functions. Betel chewing produces an increase in heart rate, blood pressure, sweating and body temperature. In addition, EEG shows widespread cortical desynchronization indicating a state of arousal. In autonomic function tests, both the sympathetic skin response and RR interval variation are affected. Betel chewing also increases plasma concentrations of norepinephrine and epinephrine. These results suggest that betel chewing mainly affects the central and autonomic nervous systems. Future studies should investigate both the acute and chronic effects of betel chewing. Such studies may further elucidate the psychoactive mechanisms responsible for the undiminished popularity of betel chewing since antiquity. Copyright 2001 National Science Council, ROC and S. Karger AG, Basel.

  7. The influence of excessive chewing gum use on headache frequency and severity among adolescents.

    Science.gov (United States)

    Watemberg, Nathan; Matar, Manar; Har-Gil, Miki; Mahajnah, Muhammad

    2014-01-01

    Excessive gum-chewing is underreported as a headache precipitant in children and adolescents. We evaluated the influence of daily excessive gum-chewing in older children and teenagers with chronic headache, emphasizing the impact of habit discontinuation and its reintroduction. Patients with chronic headache and excessive gum-chewing were consecutively recruited and asked to fill questionnaire pertaining headache characteristics, potential triggers, family history of headaches, and gum-chewing habits. These individuals were classified into four groups depending on the number of daily hours of gum-chewing. All children discontinued chewing for 1 month, reintroduced the habit, and were reinterviewed after 2 to 4 weeks. Thirty patients (25 girls) were recruited. Median age was 16 years. Most had migraine-like headaches. Following gum-chewing discontinuation, 26 reported significant improvement, including headache resolution in 19. All 20 patients reinstituting the habit reported symptom relapse within days. Duration of headache before discontinuation and the number of daily hours of chewing had no influence on the response to habit discontinuation. Excessive daily gum-chewing may be associated with chronic headache and should get more attention in the medical literature. Physician and patient awareness of this association could have a meaningful impact on the quality of life of children and adolescents with chronic headache who chew gum excessively. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Effects of chewing gum and time-on-task on alertness and attention.

    Science.gov (United States)

    Allen, A P; Smith, A P

    2012-07-01

    Chewing gum has been shown to reliably increase subjective alertness whereas the effects on attention are more variable. It has been suggested that chewing gum only enhances attention when the person has been performing a task for some time. The current research aimed to investigate if time-on-task trends enhancing effects of chewing gum could be observed in alertness and attention during and following chewing. Study 1 used tests of reported mood, including reported mood, and tests of attention (categoric search, focussed attention, simple reaction time, and vigilance). These tasks were performed shortly after the start of chewing. Study 2 examined effects of previous and current chewing on reported alertness and the attention tests. Study 1 showed that chewing gum increased reported alertness and hedonic tone and improved performance on the categoric search task. Chewing gum maintained reported alertness across sessions in study 2. In the first experimental session of study 2 gum improved categoric search performance, and during the second session gum broadened focus of attention and quickened vigilance reaction time. This effect on vigilance reaction time was moderated by time-on-task, with an initial negative effect being replaced by a positive effect. The results confirm the robust effect of chewing gum on reported alertness and show that changes in the effects of chewing gum on attention require further investigation. Future research may also determine underlying mechanisms for an alerting effect.

  9. [Effects of coca chewing on the glucose tolerance test].

    Science.gov (United States)

    Galarza Guzmán, M; Peñaloza Imaña, R; Echalar Afcha, L; Aguilar Valerio, M; Spielvogel, H; Sauvain, M

    1997-01-01

    The effects of coca chewing on the glucose tolerance test were measured. The subjects were 14 habitual coca chewers and 14 non-chewers. All were of Aymara ancestry and came from a rural community from the "Altiplano" close to the city of La Paz. The coca users chewed coca leaves during 3 1/2 hours of the test. The non-chewers showed a significant hypoglycemia at 120 minutes of the test. This effect was not observed in the coca chewers. The hormonal counter-regulation response to hypoglycemia worked perfectly in non-chewers, since glucose levels reached normal values at 180 minutes of the test. These results suggest that coca chewers, at high altitude do not present hypoglycemia, due to an antagonic action of coca metabolites on insulin; allowing a greater availability of glucose in the organism. This would have a positive effect on metabolism in an environment of hypobaric hypoxia, known to lead to situations of hypoglycemia.

  10. Antioxidant capacity of chewing stick miswak Salvadora persica

    OpenAIRE

    Mohamed, Saleh A; Khan, Jalaluddin A

    2013-01-01

    Background Chewing stick (miswak Salvadora persica L.) is an effective tool for oral hygiene. It possessed various biological properties including significant antibacterial and anti-fungal effects. In the present study, we evaluated the antioxidant compounds in miswak. Method Miswak root was extracted with 80% methanol. Methanol extract as antioxidant was evaluated by using DPPH, ABTS and phosphomolybdenum complex assays and analysis by GC-MS. Peroxidase, catalase and polyphenoloxidase assays...

  11. Areca (Betel) Nut Chewing Practices in Micronesian Populations

    Science.gov (United States)

    Paulino, Yvette C.; Novotny, Rachel; Miller, Mary Jane; Murphy, Suzanne P.

    2014-01-01

    Objective To describe the areca nut/betel quid chewing practices of Micronesian chewers living in Guam. Design Two studies were conducted using qualitative data from focus groups and quantitative cross-sectional data from the 2007 Guam Behavioral Risk Factor Surveillance System (BRFSS). Ten focus groups included 49 men and women aged 18–60 years living in Guam in 2007. Participants were areca nut/betel quid chewers selected to reflect Guam's age and ethnic group (Chamorro, Chuukese, Palauan, and Yapese) distributions. Salient themes were extracted from transcripts of the sessions by three expert reviewers. A second method, latent class analysis, was used to identify unique groups of chewers. The groups were then compared on demographics and chewing-related behaviors. Results Areca nut and betel quid recipes collected from the focus groups showed that Chamorros had a preference for the ripe nut and swallowed the nut, whereas, the Chuukese, Palauan, and Yapese groups preferred the unripe nut and did not swallow it. Similarly, latent class analysis resulted in the identification of two groups of areca nut/betel quid chewers. Group 1 was all Chamorros. Compared to Group 2, the chewers in Group 1 preferred red and ripe nuts, did not add slake lime (calcium hydroxide) or tobacco, and swallowed the masticated areca nut (with or without Piper betle leaf). Conclusion The quantitative analysis confirmed the qualitative exploration of areca nut/betel quid chewers in Guam, thus providing evidence that chewing practices vary among Micronesian populations. Implication If future research should include an intervention, the differences in chewing practices among Micronesian populations should be taken into consideration to ensure programmatic success. PMID:25678943

  12. Areca (Betel) Nut Chewing Practices in Micronesian Populations.

    Science.gov (United States)

    Paulino, Yvette C; Novotny, Rachel; Miller, Mary Jane; Murphy, Suzanne P

    2011-03-01

    To describe the areca nut/betel quid chewing practices of Micronesian chewers living in Guam. Two studies were conducted using qualitative data from focus groups and quantitative cross-sectional data from the 2007 Guam Behavioral Risk Factor Surveillance System (BRFSS). Ten focus groups included 49 men and women aged 18-60 years living in Guam in 2007. Participants were areca nut/betel quid chewers selected to reflect Guam's age and ethnic group (Chamorro, Chuukese, Palauan, and Yapese) distributions. Salient themes were extracted from transcripts of the sessions by three expert reviewers. A second method, latent class analysis, was used to identify unique groups of chewers. The groups were then compared on demographics and chewing-related behaviors. Areca nut and betel quid recipes collected from the focus groups showed that Chamorros had a preference for the ripe nut and swallowed the nut, whereas, the Chuukese, Palauan, and Yapese groups preferred the unripe nut and did not swallow it. Similarly, latent class analysis resulted in the identification of two groups of areca nut/betel quid chewers. Group 1 was all Chamorros. Compared to Group 2, the chewers in Group 1 preferred red and ripe nuts, did not add slake lime (calcium hydroxide) or tobacco, and swallowed the masticated areca nut (with or without Piper betle leaf). The quantitative analysis confirmed the qualitative exploration of areca nut/betel quid chewers in Guam, thus providing evidence that chewing practices vary among Micronesian populations. If future research should include an intervention, the differences in chewing practices among Micronesian populations should be taken into consideration to ensure programmatic success.

  13. Design, formulation and evaluation of Aloe vera chewing gum

    Science.gov (United States)

    Aslani, Abolfazl; Ghannadi, Alireza; Raddanipour, Razieh

    2015-01-01

    Background: Aloe vera has antioxidant, antiinflammatory, healing, antiseptic, anticancer and antidiabetic effects. The aim of the present study was to design and evaluate the formulation of Aloe vera chewing gum with an appropriate taste and quality with the indications for healing oral wounds, such as lichen planus, mouth sores caused by cancer chemotherapy and mouth abscesses as well as reducing mouth dryness caused by chemotherapy. Materials and Methods: In Aloe vera powder, the carbohydrate content was determined according to mannose and phenolic compounds in terms of gallic acid. Aloe vera powder, sugar, liquid glucose, glycerin, sweeteners and different flavors were added to the soft gum bases. In Aloe vera chewing gum formulation, 10% of dried Aloe vera extract entered the gum base. Then the chewing gum was cut into pieces of suitable sizes. Weight uniformity, content uniformity, the organoleptic properties evaluation, releasing the active ingredient in the phosphate buffer (pH, 6.8) and taste evaluation were examined by Latin square method. Results: One gram of Aloe vera powder contained 5.16 ± 0.25 mg/g of phenolic compounds and 104.63 ± 4.72 mg/g of carbohydrates. After making 16 Aloe vera chewing gum formulations, the F16 formulation was selected as the best formulation according to its physicochemical and organoleptic properties. In fact F16 formulation has suitable hardness, lack of adhesion to the tooth and appropriate size and taste; and after 30 min, it released more than 90% of its drug content. Conclusion: After assessments made, the F16 formulation with maltitol, aspartame and sugar sweeteners was selected as the best formulation. Among various flavors used, peppermint flavor which had the most acceptance between consumers was selected. PMID:26605214

  14. Design, formulation and evaluation of nicotine chewing gum.

    Science.gov (United States)

    Aslani, Abolfazl; Rafiei, Sahar

    2012-01-01

    Nicotine replacement therapy (NRT) can help smokers to quit smoking. Nicotine chewing gum has attracted the attention from pharmaceutical industries to offer it to consumers as an easily accessible NRT product. However, the bitter taste of such gums may compromise their acceptability by patients. This study was, therefore, designed to develop 2 and 4 mg nicotine chewing gums of pleasant taste, which satisfy the consumers the most. Nicotine, sugar, liquid glucose, glycerin, different sweetening and taste-masking agents, and a flavoring agent were added to the gum bases at appropriate temperature. The medicated gums were cut into pieces of suitable size and coated by acacia aqueous solution (2% w/v), sugar dusting, followed by acacia-sugar-calcium carbonate until a smooth surface was produced. The gums' weight variation and content uniformity were determined. The release of nicotine was studied in pH 6.8 phosphate buffer using a mastication device which simulated the mastication of chewing gum in human. The Latin Square design was used for the evaluation of organoleptic characteristics of the formulations at different stages of development. Most formulations released 79-83% of their nicotine content within 20 min. Nicotine-containing sugar-coated gums in which aspartame as sweetener and cherry and eucalyptus as flavoring agents were incorporated (i.e. formulations F(19-SC) and F(20-SC), respectively) had optimal chewing hardness, adhering to teeth, and plumpness characteristics, as well as the most pleasant taste and highest acceptability to smokers. Taste enhancement of nicotine gums was achieved where formulations comprised aspartame as the sweetener and cherry and eucalyptus as the flavoring agents. Nicotine gums of pleasant taste may, therefore, be used as NRT to assist smokers quit smoking.

  15. Attention Inhibition Training Can Reduce Betel-Nut Chewing Time

    OpenAIRE

    Ho, Ming-Chou; Li, Ren-Hau; Tang, Tze-Chun

    2011-01-01

    Betel nut (or areca) is the fourth most commonly used drug worldwide after tobacco, alcohol, and caffeine. Many chemical ingredients of betel nut are carcinogenic. We examined whether the manipulation of attentional inhibition toward the areca-related stimuli could affect betel-nut chewing time. Three matched groups of habitual chewers were recruited: inhibit-areca, inhibit-non-areca, and control. This study consisted of a Go/No-Go task for inhibition training, followed by a taste test for ob...

  16. Reasons for betel quid chewing amongst dependent and non-dependent betel quid chewing adolescents: a school-based cross-sectional survey.

    Science.gov (United States)

    Hussain, Azmina; Zaheer, Sidra; Shafique, Kashif

    2018-05-09

    Betel quid (BQ) chewing in children is initiated in their adolescence. It is pivotal to understand adolescents' reasons behind chewing BQ. In this study, we aimed to evaluate the reasons for BQ chewing amongst adolescents using reasons for betel quid chewing scale (RBCS) and their associated dependency on it. This is a cross-sectional school based survey. Out of 2200 adolescents from 26 schools of Karachi, 874 BQ chewers were assessed for their reasons of BQ chewing and dependency on it. Regression analyses were employed to report crude and adjusted (after adjusting for all reasons of BQ chewing) effect sizes with 95% confidence interval and P-value was set significant at < 0.05. Students who believed that BQ chewing relaxes them (stimulation construct) were twice as likely to be dependent on BQ (OR = 2.36, 95% CI (1.20-4.65) as compared with others. Participants who thought it eases their decision making (stimulation construct), were sizably more likely to be dependent on BQ (OR = 9.65, 95% CI (4.15-22.43) than those who did not consider ease in decision making important. Adolescents who considered not chewing as rude (social/cultural construct), were thrice more likely to be dependent on BQ (OR = 2.50, 95% CI (1.11-5.63) than others. Stimulation remained fundamental chewing reason followed by social/cultural trigger amongst adolescents. Any future intervention may get favorable results if it addresses ways to overcome stimulation and social/cultural barriers that are strongly associated with BQ chewing and dependency.

  17. Manifold Regularized Reinforcement Learning.

    Science.gov (United States)

    Li, Hongliang; Liu, Derong; Wang, Ding

    2018-04-01

    This paper introduces a novel manifold regularized reinforcement learning scheme for continuous Markov decision processes. Smooth feature representations for value function approximation can be automatically learned using the unsupervised manifold regularization method. The learned features are data-driven, and can be adapted to the geometry of the state space. Furthermore, the scheme provides a direct basis representation extension for novel samples during policy learning and control. The performance of the proposed scheme is evaluated on two benchmark control tasks, i.e., the inverted pendulum and the energy storage problem. Simulation results illustrate the concepts of the proposed scheme and show that it can obtain excellent performance.

  18. PIGE-PIXE analysis of chewing sticks of pharmacological importance

    Energy Technology Data Exchange (ETDEWEB)

    Olabanji, S.O. [Istituto Nazionale di Fisica Nucleare (INFN), Padua (Italy). Lab. Nazionali di Legnaro; Makanju, O.V. [Drug Research and Production Unit, Faculty of Pharmacy, Obafemi Awolowo University (O.A.U.), Ile-Ife (Nigeria); Haque, A.M.I. [Istituto Nazionale di Fisica Nucleare (INFN), Padua (Italy). Lab. Nazionali di Legnaro; Buoso, M.C. [Istituto Nazionale di Fisica Nucleare (INFN), Padua (Italy). Lab. Nazionali di Legnaro; Ceccato, D. [Istituto Nazionale di Fisica Nucleare (INFN), Padua (Italy). Lab. Nazionali di Legnaro]|[Dipartimento di Fisica, Universita di Padova, I-35131 Padova (Italy); Cherubini, R. [Istituto Nazionale di Fisica Nucleare (INFN), Padua (Italy). Lab. Nazionali di Legnaro; Moschini, G. [Istituto Nazionale di Fisica Nucleare (INFN), Padua (Italy). Lab. Nazionali di Legnaro]|[Dipartimento di Fisica, Universita di Padova, I-35131 Padova (Italy)

    1996-06-01

    PIGE and PIXE techniques were employed for the determination of the major, minor and trace elemental concentrations in chewing sticks of pharmacological importance namely: Butyrospermum paradoxum, Garcinia kola, Distemonanthus benthamianus, Bridelia ferruginea, Anogeissus leiocarpus, Terminalia glaucescens and Fagara rubescens, respectively. The concentration of fluorine which is very important for human dental enamel was specially determined using the {sup 19}F(p,p`{gamma}){sup 19}F reaction. For decades these chewing sticks when used alone without toothpastes have proven to be very efficient, effective and reliable in cleaning the teeth of many people particularly in Nigeria and some other countries in Africa. The teeth of users are usually very strong, clean, fresh and devoid of germs and caries. Even with the advent of modern toothpastes with special additions of fluorine, the use of these popular and efficient chewing sticks is still unabated. Many people including the elite use them solely, a few others combine their use with modern toothpastes and brush. Proton beams produced by the 7 MV CN and 2.5 MV AN 2000 Van de Graaff accelerators at INFN, Laboratori Nazionali di Legnaro (LNL), Padova, Italy were used for the PIGE and PIXE analysis, respectively. Results of this novel study are presented and discussed. (orig.).

  19. PIGE-PIXE analysis of chewing sticks of pharmacological importance

    International Nuclear Information System (INIS)

    Olabanji, S.O.; Haque, A.M.I.; Cherubini, R.

    1996-01-01

    PIGE and PIXE techniques were employed for the determination of the major, minor and trace elemental concentrations in chewing sticks of pharmacological importance namely: Butyrospermum paradoxum, Garcinia kola, Distemonanthus benthamianus, Bridelia ferruginea, Anogeissus leiocarpus, Terminalia glaucescens and Fagara rubescens, respectively. The concentration of fluorine which is very important for human dental enamel was specially determined using the 19 F(p,p'γ) 19 F reaction. For decades these chewing sticks when used alone without toothpastes have proven to be very efficient, effective and reliable in cleaning the teeth of many people particularly in Nigeria and some other countries in Africa. The teeth of users are usually very strong, clean, fresh and devoid of germs and caries. Even with the advent of modern toothpastes with special additions of fluorine, the use of these popular and efficient chewing sticks is still unabated. Many people including the elite use them solely, a few others combine their use with modern toothpastes and brush. Proton beams produced by the 7 MV CN and 2.5 MV AN 2000 Van de Graaff accelerators at INFN, Laboratori Nazionali di Legnaro (LNL), Padova, Italy were used for the PIGE and PIXE analysis, respectively. Results of this novel study are presented and discussed. (orig.)

  20. Coca leaf chewing as therapy for cocaine maintenance.

    Science.gov (United States)

    Hurtado-Gumucio, J

    2000-10-01

    Major ethnic groups in Bolivia (Aymaras and Quechuas) have chewed the coca leaf for generations upon generations without health problems. The effects of coca leaf chewing produce a level of social and economic adaptation that is beyond what is normally possible. This was a major factor during the Spanish colonization of Bolivia, when forced native labor was used extensively. The cocaine base, or "pasta", may be seen as a type of South American crack. Its obligatory method of administration is smoking. A primary condition of the "pasta" smoker is compulsive drug-search behavior and addiction to cocaine base destroys emotional and mental balance. Socio-economic maladjustment is the norm amongst "pasta" addicts. Since 1984 I have recommended the chewing of the coca leaf, between 100 to 200 grams of coca leaf per week for the treatment of cocaine dependence. Since this treatment was dispensed on an ad hoc basis, it was not possible to measure the relapses. However, an assessment was conducted on the basis of mental condition and level of social and economic adaptation before and after treatment. The patent's level of social acceptance, before treatment, only reached 60% at most, and after treatment, 26% improved their level of adaptation. Four patients among 50 reached an adaptation level of 100%. Upon final assessment, the level of social adaptation prior to treatment was only 28%, after treatment as many as 48.8% of the patients were socially adapted.

  1. Betel nut chewing and its deleterious effects on oral cavity

    Directory of Open Access Journals (Sweden)

    Richa Anand

    2014-01-01

    Full Text Available The habit of chewing betel nut has a long history of use. Betel nut and products derived from it are widely used as a masticatory product among various communities and in several countries across the world. Over a long period, several additives have been added to a simple betel nut preparation; thus, creating the betel quid (BQ and encompassing chewing tobacco in the preparation. Betel nut has deleterious effects on oral soft tissues. Its effects on dental caries and periodontal diseases, two major oral diseases are less well-documented. Betel-induced lichenoid lesions mainly on buccal mucosa have been reported at quid retained sites. In chronic chewers, a condition called betel chewers mucosa is often found where the quid is placed. Betel nut chewing is implicated in oral submucous fibrosis (OSF and its use along with tobacco can cause leukoplakia, both of which are potentially malignant in the oral cavity. Oral cancer often arises from such precancerous changes. Thus, public health measures to quit betel use are recommended to control disabling conditions such as OSF and oral cancer.

  2. Betel nut chewing and its deleterious effects on oral cavity.

    Science.gov (United States)

    Anand, Richa; Dhingra, Chandan; Prasad, Sumanth; Menon, Ipseeta

    2014-01-01

    The habit of chewing betel nut has a long history of use. Betel nut and products derived from it are widely used as a masticatory product among various communities and in several countries across the world. Over a long period, several additives have been added to a simple betel nut preparation; thus, creating the betel quid (BQ) and encompassing chewing tobacco in the preparation. Betel nut has deleterious effects on oral soft tissues. Its effects on dental caries and periodontal diseases, two major oral diseases are less well-documented. Betel-induced lichenoid lesions mainly on buccal mucosa have been reported at quid retained sites. In chronic chewers, a condition called betel chewers mucosa is often found where the quid is placed. Betel nut chewing is implicated in oral submucous fibrosis (OSF) and its use along with tobacco can cause leukoplakia, both of which are potentially malignant in the oral cavity. Oral cancer often arises from such precancerous changes. Thus, public health measures to quit betel use are recommended to control disabling conditions such as OSF and oral cancer.

  3. Factors associated with quitting areca (betel) quid chewing.

    Science.gov (United States)

    Lai, Ching-Shiun; Shieh, Tien-Yu; Yang, Yi-Hsin Connie; Chong, Mian-Yoon; Hung, Hsin-Chia; Tsai, Chi-Cheng

    2006-12-01

    The purpose of this study was to provide useful data for a future abstinence project by identifying the factors related to quitting areca (betel) quid chewing. The study was cross-sectional. Data on demographic variables, psychological factors and substance-use behaviors were collected via questionnaires from 326 participants. Multiple logistic regression analysis indicated that the areca/betel quid chewers who were less educated (OR = 0.58, 95% CI = 0.34-0.98) were least likely to try to give up. Among the chewers who tried to quit, those employed as full-time drivers (OR = 2.24, 95% CI = 1.14-4.39), who had drinking habits (OR = 2.41, 95% CI = 1.24-4.66), and who preferred to chew only betel quid wrapped with leaf (OR = 4.44, 95% CI = 1.99-9.90) were more likely to fail. Chewers who successfully quit had a higher internal health locus of control compared with those who failed to quit (one-point increments, OR = 0.94, 95% CI = 0.90-0.98). The results suggest that health educators and researchers can better influence people's chewing behavior if the importance of chewers' education level, job type, substance use (i.e. drinking habits, type of betel quid), and level of health locus of control are all taken into consideration when devising interventions.

  4. PIGE-PIXE analysis of chewing sticks of pharmacological importance

    Science.gov (United States)

    Olabanji, S. O.; Makanju, O. V.; Haque, A. M. I.; Buoso, M. C.; Ceccato, D.; Cherubini, R.; Moschini, G.

    1996-06-01

    PIGE and PIXE techniques were employed for the determination of the major, minor and trace elemental concentrations in chewing sticks of pharmacological importance namely: Butyrospermum paradoxum, Garcinia kola, Distemonanthus benthamianus, Bridelia ferruginea, Anogeissus leiocarpus, Terminalia glaucescens and Fagara rubescens, respectively. The concentration of fluorine which is very important for human dental enamel was specially determined using the 19F(p, p'γ) 19F reaction. For decades these chewing sticks when used alone without toothpastes have proven to be very efficient, effective and reliable in cleaning the teeth of many people particularly in Nigeria and some other countries in Africa. The teeth of users are usually very strong, clean, fresh and devoid of germs and caries. Even with the advent of modern toothpastes with special additions of fluorine, the use of these popular and efficient chewing sticks is still unabated. Many people including the elite use them solely, a few others combine their use with modern toothpastes and brush. Proton beams produced by the 7 MV CN and 2.5 MV AN 2000 Van de Graaff accelerators at INFN, Laboratori Nazionali di Legnaro (LNL), Padova, Italy were used for the PIGE and PIXE analysis, respectively. Results of this novel study are presented and discussed.

  5. Evaluation of Chewing and Swallowing Sensors for Monitoring Ingestive Behavior.

    Science.gov (United States)

    Fontana, Juan M; Sazonov, Edward S

    2013-03-01

    Monitoring Ingestive Behavior (MIB) of individuals is of special importance to identify and treat eating patterns associated with obesity and eating disorders. Current methods for MIB require subjects reporting every meal consumed, which is burdensome and tend to increase the reporting bias over time. This study presents an evaluation of the burden imposed by two wearable sensors for MIB during unrestricted food intake: a strain sensor to detect chewing events and a throat microphone to detect swallowing sounds. A total of 30 healthy subjects with various levels of adiposity participated in experiments involving the consumption of four meals in four different visits. A questionnaire was handled to subjects at the end of the last visit to evaluate the sensors burden in terms of the comfort levels experienced. Results showed that sensors presented high comfort levels as subjects indicated that the way they ate their meal was not considerably affected by the presence of the sensors. A statistical analysis showed that chewing sensor presented significantly higher comfort levels than the swallowing sensor. The outcomes of this study confirmed the suitability of the chewing and swallowing sensors for MIB and highlighted important aspects of comfort that should be addressed to obtain acceptable and less burdensome wearable sensors for MIB.

  6. Rhythm and amplitude of rhythmic masticatory muscle activity during sleep in bruxers - comparison with gum chewing.

    Science.gov (United States)

    Matsuda, Shinpei; Yamaguchi, Taihiko; Mikami, Saki; Okada, Kazuki; Gotouda, Akihito; Sano, Kazuo

    2016-07-01

    The aim of this study was to elucidate characteristics of rhythmic masticatory muscle activity (RMMA) during sleep by comparing masseteric EMG (electromyogram) activities of RMMA with gum chewing. The parts of five or more consecutive phasic bursts in RMMA of 23 bruxers were analyzed. Wilcoxon signed-rank test for matched pairs and Spearman's correlation coefficient by the rank test were used for statistical analysis. Root mean square value of RMMA phasic burst was smaller than that during gum chewing, but correlates to that of gum chewing. The cycle of RMMA was longer than that of gum chewing due to the longer burst duration of RMMA, and variation in the cycles of RMMA was wider. These findings suggest that the longer but smaller EMG burst in comparison with gum chewing is one of the characteristics of RMMA. The relation between size of RMMA phasic bursts and gum chewing is also suggested.

  7. Ex vivo determination of chewing patterns using FBG and artificial neural networks

    Science.gov (United States)

    Karam, L. Z.; Pegorini, V.; Pitta, C. S. R.; Assmann, T. S.; Cardoso, R.; Kalinowski, H. J.; Silva, J. C. C.

    2014-05-01

    This paper reports the experimental procedures performed in a bovine head for the determination of chewing patterns during the mastication process. Mandible movements during the chewing have been simulated either by using two plasticine materials with different textures or without material. Fibre Bragg grating sensors were fixed in the jaw to monitor the biomechanical forces involved in the chewing process. The acquired signals from the sensors fed the input of an artificial neural network aiming at the classification of the measured chewing patterns for each material used in the experiment. The results obtained from the simulation of the chewing process presented different patterns for the different textures of plasticine, resulting on the determination of three chewing patterns with a classification error of 5%.

  8. Betel nut chewing, oral premalignant lesions, and the oral microbiome.

    Science.gov (United States)

    Hernandez, Brenda Y; Zhu, Xuemei; Goodman, Marc T; Gatewood, Robert; Mendiola, Paul; Quinata, Katrina; Paulino, Yvette C

    2017-01-01

    Oral cancers are attributed to a number of causal agents including tobacco, alcohol, human papillomavirus (HPV), and areca (betel) nut. Although betel nut chewing has been established as an independent cause of oral cancer, the mechanisms of carcinogenesis are poorly understood. An investigation was undertaken to evaluate the influence of betel nut chewing on the oral microbiome and oral premalignant lesions. Study participants were recruited from a dental clinic in Guam. Structured interviews and oral examinations were performed. Oral swabbing and saliva samples were evaluated by 454 pyrosequencing of the V3- V5 region of the 16S rRNA bacterial gene and genotyped for HPV. One hundred twenty-two adults were enrolled including 64 current betel nut chewers, 37 former chewers, and 21 with no history of betel nut use. Oral premalignant lesions, including leukoplakia and submucous fibrosis, were observed in 10 chewers. Within-sample bacterial diversity was significantly lower in long-term (≥10 years) chewers vs. never chewers and in current chewers with oral lesions vs. individuals without lesions. Between-sample bacterial diversity based on Unifrac distances significantly differed by chewing status and oral lesion status. Current chewers had significantly elevated levels of Streptococcus infantis and higher and lower levels of distinct taxa of the Actinomyces and Streptococcus genera. Long-term chewers had reduced levels of Parascardovia and Streptococcus. Chewers with oral lesions had significantly elevated levels of Oribacterium, Actinomyces, and Streptococcus, including Streptococcus anginosus. In multivariate analyses, controlling for smoking, oral HPV, S.anginosus, and S. infantis levels, current betel nut chewing remained the only predictor of oral premalignant lesions. Our study provides evidence that betel nut chewing alters the oral bacterial microbiome including that of chewers who develop oral premalignant lesions. Nonetheless, whether microbial changes

  9. Chewing gum, occupational stress, work performance and wellbeing. An intervention study.

    Science.gov (United States)

    Smith, Andrew P; Chaplin, Katherine; Wadsworth, Emma

    2012-06-01

    An intervention study was carried out to examine the effects of chewing gum on occupational stress and related outcomes. 101 volunteers from Cardiff University completed the study. The results showed that chewing gum reduced stress (both at work and outside work), reduced fatigue, reduced anxiety and depression and led to a more positive mood. Chewing gum was also associated with perceptions of better performance (both at work and outside). Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Betel quid chewing in rural Bangladesh: prevalence, predictors and relationship to blood pressure.

    Science.gov (United States)

    Heck, Julia E; Marcotte, Erin L; Argos, Maria; Parvez, Faruque; Ahmed, Alauddin; Islam, Tariqul; Sarwar, Golam; Hasan, Rabiul; Ahsan, Habibul; Chen, Yu

    2012-04-01

    Betel quid is chewed by 600 million people worldwide and it has been linked to obesity and cardiovascular disease. The purpose of our study was to examine the prevalence and predictors of betel quid chewing in a rural area of Bangladesh, and determine its effects on body mass index (BMI) and blood pressure. In this population-based prospective study, we analysed data on 19 934 Bangladeshi adults. Linear and multivariate logistic regression was used to determine the socio-demographic predictors of betel quid chewing and the effect of betel quid on change in BMI and on systolic and diastolic blood pressure, pulse pressure, arterial pressure, overweight or obesity, and hypertension. At baseline, betel quid was chewed by 33.2% of the cohort (35.5% of men, 31.6% of women). In a subsample in which we collected methods of use, 17.5% chewed it without tobacco and 82.5% chewed it with tobacco. In multivariate analysis, betel quid chewing was associated with female sex, older age, tobacco smoking and lower socio-economic status, as measured by fewer years of formal education and not owning land. Betel quid was chewed more times per day among women and older persons. At follow-up, persons who chewed betel quid without tobacco had higher systolic blood pressure, diastolic blood pressure and arterial pressure in comparison with never users. After controlling for other explanatory variables, chewing betel quid without tobacco was associated with general hypertension [odds ratio (OR) 1.48, 95% confidence interval (CI) 1.04-2.10] and systolic hypertension (OR 1.55, 95% CI 1.01-2.37). We did not observe associations of betel quid chewing with BMI or overweight. Betel quid chewing is likely contributing to high blood pressure in Bangladesh, particularly among women.

  11. Chewing Gum: Cognitive Performance, Mood, Well-Being, and Associated Physiology

    OpenAIRE

    Allen, Andrew P.; Smith, Andrew P.

    2015-01-01

    Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies) examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on w...

  12. Chewing gum benefits sustained attention in the absence of task degradation.

    OpenAIRE

    Johnson, A.J.; Muneem, M.; Miles, C.

    2013-01-01

    OBJECTIVES: The present study examined the effect of chewing gum on sustained attention and associated changes in subjective alertness. METHODS: In a within-participants design, 20 participants completed an extended version of the sustained attention response task (SART: Robertson et al., 1997), both with and without chewing gum. Self-rated measures of alertness, contentedness, and calmness were taken before and after the SART. RESULTS: Chewing gum was associated with improved attentional tas...

  13. Cardiovascular responses in humans to experimental chewing of gums of different consistencies.

    Science.gov (United States)

    Farella, M; Bakke, M; Michelotti, A; Marotta, G; Martina, R

    1999-10-01

    Although the cardiovascular effects of exercise have been extensively investigated in man, little attention has been paid to such responses to jaw muscle activity. The aim here was to investigate the general cardiovascular effects of chewing activity in a single-blind, cross-over design. Ten healthy individuals performed one of the following chewing tasks in four separate sessions: chewing a very hard gum, chewing a moderately hard gum, chewing a soft gum, and "empty chewing" without a bolus. Unilateral chewing of gum or empty chewing was performed for 20 min on the participant's most convenient chewing side at a constant rate of 80 cycles/min. In each session, heart rate and arterial blood pressure were recorded together with electromyographic activity in the masseter and anterior temporalis muscles on the chewing side. Ratings of perceived masticatory fatigue were recorded with visual analogue scales. The heart rate and blood pressure were significantly increased (ANOVA; p chewing tasks and the increases were, in parallel with the muscle activity, more pronounced the harder the gum. With the very hard gum, heart rate increased by up to 11 beats/min, the systolic blood pressure was 14 mmHg (1.9kPa) higher, and the diastolic blood pressure was 11 mmHg (1.5kPa) higher. The perceived fatigue was proportional to the level of muscle activity. After 10 min of recovery from exercise, heart rate and arterial blood pressures were slightly but still significantly elevated. The results demonstrate that chewing is associated with general circulatory effects proportional to the bolus resistance.

  14. Effects of chewing gum on mood, learning, memory and performance of an intelligence test.

    Science.gov (United States)

    Smith, Andrew

    2009-04-01

    Recent research suggests that chewing gum may increase alertness and lead to changes in cognitive performance. The present study examined effects of chewing gum on these functions within the context of a single study. This study had four main aims. The first was to examine whether chewing gum improved learning and memory of information in a story. The second aim was to determine whether chewing gum improved test performance on a validated intellectual task (the Alice Heim task). A third aim was to determine whether chewing gum improved performance on short memory tasks (immediate and delayed recall of a list of words, delayed recognition memory, retrieval from semantic memory, and a working memory task). The final aim was to determine whether chewing gum improved mood (alertness, calm and hedonic tone). A cross-over design was used with gum and no-gum sessions being on consecutive weeks. In each week, volunteers attended for two sessions, two days apart. The first session assessed mood, immediate recall of information from a story and performance on short memory tasks. The second session assessed mood, delayed recall of information from a story and performance of an intelligence test (the Alice Heim test). There were no significant effects of chewing gum on any aspect of recall of the story. Chewing gum improved the accuracy of performing the Alice Heim test which confirms the benefits of gum on test performance seen in an earlier study. Chewing gum had no significant effect on the short memory tasks. Chewing gum increased alertness at the end of the test session in both parts of the study. This effect was in the region of a 10% increase and was highly significant (P increases alertness. In contrast, no significant effects of chewing gum were observed in the memory tasks. Intellectual performance was improved in the gum condition. Overall, the results suggest further research on the alerting effects of chewing gum and possible improved test performance in these

  15. Pion-nucleon vertex function and the Chew-Low model

    International Nuclear Information System (INIS)

    Nutt, W.T.

    1977-01-01

    We provide an interpretation of the cutoff function used in the Chew-Low theory of pion-nucleon scattering. It is shown that this function may be related to the pion-pion interaction which is not explicitly considered in the Chew-Low approach. Using a previously developed model for the pion-nucleon vertex function, we then perform a ''parameter-free'' Chew-Low calculation which predicts the P 33 resonance quite well

  16. In situ effect of CPP-ACP chewing gum upon erosive enamel loss

    Directory of Open Access Journals (Sweden)

    Catarina Ribeiro Barros de ALENCAR

    Full Text Available Abstract Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP is able to increase salivary calcium and phosphate levels at an acidic pH. Previous studies demonstrated that a CPP-ACP chewing gum was able to enhance the re-hardening of erosion lesions, but could not diminish enamel hardness loss. Therefore, there is no consensus regarding the effectiveness of CPP-ACP on dental erosion. Objective This in situ study investigated the ability of a CPP-ACP chewing gum in preventing erosive enamel loss. Material and Methods: During three experimental crossover phases (one phase per group of seven days each, eight volunteers wore palatal devices with human enamel blocks. The groups were: GI – Sugar free chewing gum with CPP-ACP; GII – Conventional sugar free chewing gum; and GIII – No chewing gum (control. Erosive challenge was extraorally performed by immersion of the enamel blocks in cola drink (5 min, 4x/day. After each challenge, in groups CPP and No CPP, volunteers chewed one unit of the corresponding chewing gum for 30 minutes. Quantitative analysis of enamel loss was performed by profilometry (µm. Data were analyzed by Repeated-Measures ANOVA and Tukey’s test (p0.05. Conclusion The CPP-ACP chewing gum was not able to enhance the anti-erosive effect of conventional chewing gum against enamel loss.

  17. Differences in chewing behaviors between healthy fully dentate young and older adults assessed by electromyographic recordings.

    Science.gov (United States)

    Zhu, Yong; Hollis, James H

    2015-01-01

    To characterize changes in chewing behaviors associated with healthy aging, 10 young and 10 older fully dentate healthy participants were enrolled in this study. They chewed carrot samples that differed in hardness until their normal swallowing threshold. Their chewing behaviors were assessed using an electromyographic recording device. Adjusting for gender and body mass index, older adults had a higher number of chewing cycles (p = 0.020), a longer chewing duration (p chewing rate (p = 0.002), a greater maximal electromyographic voltage (p = 0.003) and a greater muscle activity (p = 0.002) before they could comfortably swallow the food bolus. A statistically significant main effect of food hardness on the number of chewing cycles, chewing duration, chewing rate and muscle activity was also observed (p < 0.001 for all). These results suggest that reduced mastication efficiency is associated with healthy aging in fully dentate adults. This ingestive behavior may contribute to aging-related reduction in appetite in older adults.

  18. A clinical protocol to increase chewing and assess mastication in children with feeding disorders.

    Science.gov (United States)

    Volkert, Valerie M; Peterson, Kathryn M; Zeleny, Jason R; Piazza, Cathleen C

    2014-09-01

    Children with feeding disorders often cannot or do not chew when presented with table food. Children with chewing deficits also often swallow the bite before masticating it appropriately, which we will refer to as early swallowing. In the current study, we evaluated a clinical protocol to increase chews per bite, assess mastication, and eliminate early swallowing with three children with feeding disorders. The current study adds to a small body of literature on chewing and mastication of children with feeding disorders. Suggestions for future research are also discussed. © The Author(s) 2014.

  19. Diverse Regular Employees and Non-regular Employment (Japanese)

    OpenAIRE

    MORISHIMA Motohiro

    2011-01-01

    Currently there are high expectations for the introduction of policies related to diverse regular employees. These policies are a response to the problem of disparities between regular and non-regular employees (part-time, temporary, contract and other non-regular employees) and will make it more likely that workers can balance work and their private lives while companies benefit from the advantages of regular employment. In this paper, I look at two issues that underlie this discussion. The ...

  20. Sparse structure regularized ranking

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-04-17

    Learning ranking scores is critical for the multimedia database retrieval problem. In this paper, we propose a novel ranking score learning algorithm by exploring the sparse structure and using it to regularize ranking scores. To explore the sparse structure, we assume that each multimedia object could be represented as a sparse linear combination of all other objects, and combination coefficients are regarded as a similarity measure between objects and used to regularize their ranking scores. Moreover, we propose to learn the sparse combination coefficients and the ranking scores simultaneously. A unified objective function is constructed with regard to both the combination coefficients and the ranking scores, and is optimized by an iterative algorithm. Experiments on two multimedia database retrieval data sets demonstrate the significant improvements of the propose algorithm over state-of-the-art ranking score learning algorithms.

  1. 'Regular' and 'emergency' repair

    International Nuclear Information System (INIS)

    Luchnik, N.V.

    1975-01-01

    Experiments on the combined action of radiation and a DNA inhibitor using Crepis roots and on split-dose irradiation of human lymphocytes lead to the conclusion that there are two types of repair. The 'regular' repair takes place twice in each mitotic cycle and ensures the maintenance of genetic stability. The 'emergency' repair is induced at all stages of the mitotic cycle by high levels of injury. (author)

  2. Regularization of divergent integrals

    OpenAIRE

    Felder, Giovanni; Kazhdan, David

    2016-01-01

    We study the Hadamard finite part of divergent integrals of differential forms with singularities on submanifolds. We give formulae for the dependence of the finite part on the choice of regularization and express them in terms of a suitable local residue map. The cases where the submanifold is a complex hypersurface in a complex manifold and where it is a boundary component of a manifold with boundary, arising in string perturbation theory, are treated in more detail.

  3. Regularizing portfolio optimization

    International Nuclear Information System (INIS)

    Still, Susanne; Kondor, Imre

    2010-01-01

    The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

  4. Regularizing portfolio optimization

    Science.gov (United States)

    Still, Susanne; Kondor, Imre

    2010-07-01

    The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

  5. Regular Single Valued Neutrosophic Hypergraphs

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Malik

    2016-12-01

    Full Text Available In this paper, we define the regular and totally regular single valued neutrosophic hypergraphs, and discuss the order and size along with properties of regular and totally regular single valued neutrosophic hypergraphs. We also extend work on completeness of single valued neutrosophic hypergraphs.

  6. The geometry of continuum regularization

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1987-03-01

    This lecture is primarily an introduction to coordinate-invariant regularization, a recent advance in the continuum regularization program. In this context, the program is seen as fundamentally geometric, with all regularization contained in regularized DeWitt superstructures on field deformations

  7. Chewing ability in an urban and rural population over 40 years in Shandong Province, China.

    Science.gov (United States)

    Zhang, Qian; Witter, Dick J; Bronkhorst, Ewald M; Creugers, Nico H J

    2013-06-01

    This study aimed to assess chewing ability related to dental status. One thousand four hundred sixty-two Chinese subjects over 40 years, dentate in both jaws, were categorized in a hierarchical functional classification system with and without tooth replacements. Chewing ability was analyzed using multivariable logistic regression including five dental conditions ( "≥10 teeth in each jaw"; "complete anterior regions"; "sufficient premolar regions" (≥3 posterior occluding pairs (POPs)); "sufficient molar regions" (bilaterally ≥1 POP); and tooth replacement), adjusted for six background variables. Likelihood ratios for chewing problems were assessed at each level of the hierarchical classification system based on these dental conditions. Seventy-eight to 91 % of subjects reported no or minor chewing problems. The conditions "≥10 teeth in each jaw", and "complete anterior regions" were not associated, whereas "sufficient premolar regions" and "sufficient molar regions" were associated with chewing problems (Ors, 0.33–0.58). If classified hierarchically, the condition "≥10 teeth in each jaw" was relevant for chewing problems (likelihood ratios 3.3–3.7). "Sufficient premolar region" and "sufficient molar region" were relevant to reduce the likelihood ratios for having chewing problems (both approximately with a factor 2), both for soft and for hard foods. Subjects with artificial teeth added had similar chance for chewing problems compared to counterparts with natural teeth only. However, if comparing replaced teeth with natural teeth, subjects with tooth replacement showed higher chance for chewing problems. Chewing ability was strongly associated with dental conditions. The presence of at least 10 teeth in each jaw had highest impact on chewing ability.

  8. Evaluation of accelerated stability test conditions for medicated chewing gums.

    Science.gov (United States)

    Maggi, Lauretta; Conte, Ubaldo; Nhamias, Alain; Grenier, Pascal; Vergnault, Guy

    2013-10-01

    The overall stability of medicated chewing gums is investigated under different storage conditions. Active substances with different chemical stabilities in solid state are chosen as model drugs. The dosage form is a three layer tablet obtained by direct compression. The gum core contains the active ingredient while the external layers are formulated to prevent gum adhesion to the punches of the tableting machine. Two accelerated test conditions (40°C/75% RH and 30°C/65% RH) are performed for 6 months. Furthermore, a long-term stability test at room conditions is conducted to verify the predictability of the results obtained from the stress tests. Some drugs are stable in all the conditions tested, but other drugs, generally considered stable in solid dosage forms, have shown relevant stability problems particularly when stress test conditions are applied to this particular semi-solid dosage forms. For less stable drugs, the stress conditions of 40°C/75% RH are not always predictable of chewing gum stability at room temperature and may produce false negative; intermediate conditions, 30°C/65% RH, are more predictive for this purpose, the results of drug content found after 6 months at intermediate stress conditions and 12 months at room conditions are generally comparable. But the results obtained show that only long-term conditions stability tests gave consistent results. During aging, the semi solid nature of the gum base itself, may also influence the drug delivery rate during chewing and great attention should be given also to the dissolution stability.

  9. Inverse scattering solution of the Chew-Low equation

    International Nuclear Information System (INIS)

    Nakano, K.

    1985-01-01

    Techniques for solving the inverse scattering problem are applied to the Chew-Low equation to obtain the nucleon form factor directly from the experimental phase shifts. A new dispersion relation is derived for the P 11 wave because of its sign-changing phase shift. A self-consistent solution for each channel is obtained, but the universality of form factor is not confirmed. Also, an iterative procedure based on Omnes' method is developed in order to solve coupled-channel, singular integral equations. (orig.)

  10. Annotation of Regular Polysemy

    DEFF Research Database (Denmark)

    Martinez Alonso, Hector

    Regular polysemy has received a lot of attention from the theory of lexical semantics and from computational linguistics. However, there is no consensus on how to represent the sense of underspecified examples at the token level, namely when annotating or disambiguating senses of metonymic words...... and metonymic. We have conducted an analysis in English, Danish and Spanish. Later on, we have tried to replicate the human judgments by means of unsupervised and semi-supervised sense prediction. The automatic sense-prediction systems have been unable to find empiric evidence for the underspecified sense, even...

  11. Regularity of Minimal Surfaces

    CERN Document Server

    Dierkes, Ulrich; Tromba, Anthony J; Kuster, Albrecht

    2010-01-01

    "Regularity of Minimal Surfaces" begins with a survey of minimal surfaces with free boundaries. Following this, the basic results concerning the boundary behaviour of minimal surfaces and H-surfaces with fixed or free boundaries are studied. In particular, the asymptotic expansions at interior and boundary branch points are derived, leading to general Gauss-Bonnet formulas. Furthermore, gradient estimates and asymptotic expansions for minimal surfaces with only piecewise smooth boundaries are obtained. One of the main features of free boundary value problems for minimal surfaces is t

  12. Regularities of radiation heredity

    International Nuclear Information System (INIS)

    Skakov, M.K.; Melikhov, V.D.

    2001-01-01

    One analyzed regularities of radiation heredity in metals and alloys. One made conclusion about thermodynamically irreversible changes in structure of materials under irradiation. One offers possible ways of heredity transmittance of radiation effects at high-temperature transformations in the materials. Phenomenon of radiation heredity may be turned to practical use to control structure of liquid metal and, respectively, structure of ingot via preliminary radiation treatment of charge. Concentration microheterogeneities in material defect structure induced by preliminary irradiation represent the genetic factor of radiation heredity [ru

  13. Chewing and spitting out food as a compensatory behavior in patients with eating disorders.

    Science.gov (United States)

    Song, Youn Joo; Lee, Jung-Hyun; Jung, Young-Chul

    2015-10-01

    Recent studies suggest that chewing and spitting out food may be associated with severe eating-related pathology. The purpose of this study was to investigate the relationship between chewing and spitting, and other symptoms of eating disorders. We hypothesized that patients who chew and spit as a compensatory behavior have more severe eating-related pathology than patients who have never engaged in chewing and spitting behavior. We divided 359 patients with eating disorders into two groups according to whether they engaged in chewing and spitting as a compensatory behavior to lose weight or not. After comparing eating-related pathology between the two groups, we examined factors associated with pathologic eating behaviors using logistic regression analysis. Among our 359 participants, 24.5% reported having engaged in chewing and spitting as a compensatory behavior. The chewing and spitting (CHSP+) group showed more severe eating disorder symptoms and suicidal behaviors. This group also had significantly higher scores on subscales that measured drive for thinness, bulimia, and impulse regulation on the EDI-2, Food Craving Questionnaire, Body Shape Questionnaire, Beck Depression Inventory, Beck Anxiety Inventory, and Maudsley Obsessive Compulsive Inventory. Chewing and spitting is a common compensatory behavior among patients with eating disorders and is associated with more-pathologic eating behaviors and higher scores on psychometric tests. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. A Pilot Study to Increase Chewing in Children with Feeding Disorders

    Science.gov (United States)

    Volkert, Valerie M.; Piazza, Cathleen C.; Vaz, Petula C. M.; Frese, Jana

    2013-01-01

    Children with feeding disorders often display chewing deficits. Unfortunately, there is a paucity of research examining procedures to increase or teach chewing to children with feeding disorders. The few studies on this topic have utilized multicomponent treatments typically involving a shaping procedure. In addition, to our knowledge, studies on…

  15. Simultaneous multielement determination of chewing and snuff tobaccos used in India by INAA

    International Nuclear Information System (INIS)

    Mishra, U.C.; Shaikh, G.N.

    1986-01-01

    Trace elements present in Indian cigarette tobacco and cigarette smoke were reported earlier. This paper presents trace element concentrations in chewing and snuff tobaccos determined by INAA. The levels of Br, Co, Cr, Fe, Mn, Zn, etc., present in different brands of chewing and snuff tobaccos are compared in two types of tobacco as well as with similar data from other countires. (author)

  16. Algorithms for the detection of chewing behavior in dietary monitoring applications

    Science.gov (United States)

    Schmalz, Mark S.; Helal, Abdelsalam; Mendez-Vasquez, Andres

    2009-08-01

    The detection of food consumption is key to the implementation of successful behavior modification in support of dietary monitoring and therapy, for example, during the course of controlling obesity, diabetes, or cardiovascular disease. Since the vast majority of humans consume food via mastication (chewing), we have designed an algorithm that automatically detects chewing behaviors in surveillance video of a person eating. Our algorithm first detects the mouth region, then computes the spatiotemporal frequency spectrum of a small perioral region (including the mouth). Spectral data are analyzed to determine the presence of periodic motion that characterizes chewing. A classifier is then applied to discriminate different types of chewing behaviors. Our algorithm was tested on seven volunteers, whose behaviors included chewing with mouth open, chewing with mouth closed, talking, static face presentation (control case), and moving face presentation. Early test results show that the chewing behaviors induce a temporal frequency peak at 0.5Hz to 2.5Hz, which is readily detected using a distance-based classifier. Computational cost is analyzed for implementation on embedded processing nodes, for example, in a healthcare sensor network. Complexity analysis emphasizes the relationship between the work and space estimates of the algorithm, and its estimated error. It is shown that chewing detection is possible within a computationally efficient, accurate, and subject-independent framework.

  17. Betel Nut Chewing Behavior among Adolescents in Eastern Taiwan: A Cluster Analysis

    Science.gov (United States)

    Chen, Han-Ying; Waigandt, Alex C.

    2009-01-01

    The prevalence of betel nut chewing among junior high school students is highest in the eastern region of Taiwan (Lin, 1990). Although there is some research on the prevalence rate, little effort has been paid to developing a classification of betel nut chewing behavior applicable to adolescents. Eight-hundred and forty-three students, including…

  18. Properties of a color-changeable chewing gum used to evaluate masticatory performance.

    Science.gov (United States)

    Hama, Yohei; Kanazawa, Manabu; Minakuchi, Shunsuke; Uchida, Tatsuro; Sasaki, Yoshiyuki

    2014-04-01

    To clarify the basic properties of a color-changeable chewing gum to determine its applicability to evaluations of masticatory performance under different types of dental status. Ten participants with natural dentition aged 26-30 years chewed gum that changes color during several chewing strokes over five repetitions. Changes in color were assessed using a colorimeter, and then L*, a*, and b* values in the CIELAB color system were quantified. Relationships between chewing progression and color changes were assessed using regression analysis and the reliability of color changes was assessed using intraclass correlation coefficients. We then measured 42 dentate participants (age, 22-31 years) and 47 complete denture wearers (age, 44-90 years) to determine the detectability of masticatory performance under two types of dental status. Regression between the number of chewing strokes and the difference between two colors was non-linear. The intraclass correlation coefficients were highest between 60 and 160 chewing strokes. Dentate and edentulous groups significantly differed (Wilcoxon rank sum test) and values were widely distributed within each group. The color of the chewing gum changed over a wide range, which was sufficient to evaluate the masticatory performance of individuals with natural dentition and those with complete dentures. Changes in the color values of the gum reliably reflected masticatory performance. These findings indicate that the color-changeable chewing gum will be useful for evaluating masticatory performance under any dental status. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  19. Fluoride and urea chewing gums in an intra-oral experimental caries model

    NARCIS (Netherlands)

    Sjogren, K; Ruben, J; Lingstrom, P; Lundberg, AB; Birkhed, D

    2002-01-01

    The aim of the present investigation was to evaluate the effect of sugar-free chewing gums containing fluoride (F) and urea in an intra-oral experimental caries model. Placebo chewing gums (without any active ingredient) and no gum served as controls. Fifteen subjects participated in a cross-over,

  20. Chewing side preference - Impact on facial symmetry, dentition and temporomandibular joint and its correlation with handedness

    Directory of Open Access Journals (Sweden)

    Shreyasi Tiwari

    2017-01-01

    Full Text Available Introduction: Habitual unilateral chewing develops subconsciously and serves as an example for lateral preference. This study aims to assess the possible impact of chewing side preference to facial asymmetry, temporomandibular joint (TMJ and oral hygiene and existence of any link between the preferred chewing side (PCS and handedness. Materials and Methods: A 2-month cross-sectional (observational study was performed on 76 healthy dentate subjects [24 males (31.6% and 52 females (68.4%] with a mean age of 20.8 ± 1.5 years who participated in this study according to the selection criteria. Results: A total of 75 subjects out of 76 (98.6% were observed to have a PCS. Out of them, 38 chewed on their right and 37 on the left side. Of the 74 right-handed subjects, 48.6% chewed on the right, 50% on the left and 1.4% chewed equally on both the sides. Conclusion: Chewing side preference has a detrimental effect on the TMJ of the corresponding side and is also related to lateral facial asymmetry, which suggests that examination and recording of chewing side preference merit consideration in routine dental examination and treatment planning.

  1. Combined Effects of Chewing Ability and Dietary Diversity on Medical Service Use and Expenditures.

    Science.gov (United States)

    Lo, Yuan-Ting C; Wahlqvist, Mark L; Chang, Yu-Hung; Lee, Meei-Shyuan

    2016-06-01

    To examine whether chewing ability affects healthcare use and expenditure and whether improving dietary quality alleviates any such effects. Prospective cohort. The Elderly Nutrition and Health Survey in Taiwan (1999-2000), a nationwide community-based survey of people aged 65 and older. Individuals aged 65 and older (N = 1,793; 903 men, 890 women). Chewing ability (satisfactory or unsatisfactory) was assessed using a questionnaire, and dietary quality was assessed using a 24-hour dietary recall as a dietary diversity score. Data on annual medical use and expenditures from the interview date until December 31, 2006, were collected from National Health Insurance claims. Generalized linear models were used to assess the associations between chewing ability, dietary quality, and annual medical usage or expenditure. After 8 years of follow-up, older adults with unsatisfactory chewing ability had considerably higher emergency, hospitalization, and total medical expenditures. Older adults with unsatisfactory chewing ability and a poor diet used fewer annual preventive care and dental services than those with satisfactory chewing ability but had longer hospital stays and higher expenditures. After adjusting for covariates, unsatisfactory chewing ability resulted in significantly longer hospital stays in participants with a poor diet (β = 2.34, 95% confidence interval = 2.02-2.71, P chewing ability and a less-diverse diet together are associated with longer hospital stays and higher medical expenditures. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  2. Gum chewing improves adolescents’ math performance in an SAT preparatory course

    Science.gov (United States)

    The purpose of the current study was to determine the effect of gum chewing on students’ performance in a preparatory course for the Scholastic Aptitude Test (SAT). A total of 182 adolescents enrolled in an SAT preparatory class were randomized into one of two treatments: 1) gum chewing condition (G...

  3. Chewing Gum: Cognitive Performance, Mood, Well-Being, and Associated Physiology

    Science.gov (United States)

    Allen, Andrew P.; Smith, Andrew P.

    2015-01-01

    Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies) examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on well-being and performance, as well as postwork mood and cognitive performance. In Study 4, performance and well-being were reported throughout the workday and at the end of the day, and heart rate and cortisol were measured. Under experimental conditions, gum was associated with higher alertness regardless of whether performance tasks were completed and altered sustained attention. Rate of chewing and subjective force of chewing did not alter mood but had some limited effects on attention. Chewing gum during the workday was associated with higher productivity and fewer cognitive problems, raised cortisol levels in the morning, and did not affect heart rate. The results emphasise that chewing gum can attenuate reductions in alertness, suggesting that chewing gum enhances worker performance. PMID:26075253

  4. A generating function for a class of effective Chew-Mandelstam functions

    International Nuclear Information System (INIS)

    Reid, J.H.

    1982-12-01

    We have obtained the generating function for a class of effective Chew-Mandelstam functions for arbitrary integral angular momentum. From this a closed formula for the Chew-Mandelstam functions themselves is derived in both the simple equal mass case and in the more complicated case of unequal masses

  5. The Effects of Preventive Intervention for Betel Nut Chewing in School

    Science.gov (United States)

    Wang, Su-Chen; Tsai, Chi-Cheng; Huang, Shun-Te; Hong, Yu-Jue

    2007-01-01

    Purpose: This study was to explore the effect of preventive health education intervention in the knowledge, attitude, practice of betel nut chewing, and self-efficacy of anti-betel nut chewing for adolescent students. Methods: One hundred eighty-six indigenous samples were recruited, and divided into experimental and control groups. The…

  6. Release of peppermint flavour compounds from chewing gum: effect of oral functions

    DEFF Research Database (Denmark)

    Haahr, Anne-Mette; Bardow, A.; Thomsen, C.E.

    2004-01-01

    comprised three separate series of a 4-min chewing period. These series differed only with respect to CF, i.e., habitual frequency, and 60 and 88 strokes/min. Results showed that more than 50% of the released menthol and menthone could be retrieved in the expired air and saliva. After 2-min of chewing...

  7. Chewing Gum: Cognitive Performance, Mood, Well-Being, and Associated Physiology

    Directory of Open Access Journals (Sweden)

    Andrew P. Allen

    2015-01-01

    Full Text Available Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on well-being and performance, as well as postwork mood and cognitive performance. In Study 4, performance and well-being were reported throughout the workday and at the end of the day, and heart rate and cortisol were measured. Under experimental conditions, gum was associated with higher alertness regardless of whether performance tasks were completed and altered sustained attention. Rate of chewing and subjective force of chewing did not alter mood but had some limited effects on attention. Chewing gum during the workday was associated with higher productivity and fewer cognitive problems, raised cortisol levels in the morning, and did not affect heart rate. The results emphasise that chewing gum can attenuate reductions in alertness, suggesting that chewing gum enhances worker performance.

  8. Chewing gum: cognitive performance, mood, well-being, and associated physiology.

    Science.gov (United States)

    Allen, Andrew P; Smith, Andrew P

    2015-01-01

    Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies) examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on well-being and performance, as well as postwork mood and cognitive performance. In Study 4, performance and well-being were reported throughout the workday and at the end of the day, and heart rate and cortisol were measured. Under experimental conditions, gum was associated with higher alertness regardless of whether performance tasks were completed and altered sustained attention. Rate of chewing and subjective force of chewing did not alter mood but had some limited effects on attention. Chewing gum during the workday was associated with higher productivity and fewer cognitive problems, raised cortisol levels in the morning, and did not affect heart rate. The results emphasise that chewing gum can attenuate reductions in alertness, suggesting that chewing gum enhances worker performance.

  9. High α - radioactivity level in betel leaf (Piper Betel) and chewing tobacco

    International Nuclear Information System (INIS)

    Ghosh, Dipak; Deb, Argha; Maiti, Sunil; Harh, Sadananda

    2011-01-01

    Studies on alpha emitting radionuclides in tobacco samples is of significant importance as the interaction of alpha particles with cells chromosomes in different organs of tobacco eaters causes to carcinogenic changes in those organs. Apart from smoking, the tobacco products that are smokeless, like ghutka, chewing tobacco, etc., that are directly consumed through orally also contribute to carcinogenic health hazards. They can increase the internal radiation dose and thereby enhance the case of cancer in human population. Another important sample is betel leaf which is largely consumed by people. Since betel leaf is cultivated in lands using fertilizers having high alpha activity. Regular use of betel leaf may cause health hazards if alpha radioactivity is present in harmful quantities. In view of this the present work betel leafs and different type of tobacco products have been collected from the local market in and around Kolkata and alpha activity of those samples have been measured using CR-39 (SSNTD) detectors and dose has been estimated. (author)

  10. Health risk perception and betel chewing behavior--the evidence from Taiwan.

    Science.gov (United States)

    Chen, Chiang-Ming; Chang, Kuo-Liang; Lin, Lin; Lee, Jwo-Leun

    2013-11-01

    In this study, we provided an empirical examination of the interaction between people's health risk perception and betel chewing. We hypothesized that a better knowledge of possible health risks would reduce both the number of individuals who currently chew betel and the likelihood of those who do not yet chew betel to begin the habit. We constructed a simultaneous equation model with Bayesian two-stage approach to control the endogeneity between betel chewing and risk perception. Using a national survey of 26,684 observations in Taiwan, our study results indicated that better health knowledge reduced the possibility that people would become betel chewers. We also found that, in general, betel chewers have a poorer health risk perception than other population. Overall, the empirical evidence suggested that health authorities could reduce the odds of people becoming betel chewers by improving their knowledge of betel-chewing's harmful effects. © 2013 Elsevier Ltd. All rights reserved.

  11. Radioactivity and trace element contents of commercial chewing tobacco

    International Nuclear Information System (INIS)

    Dafauti, S.; Pulhani, V.; Dahiya, S.; Hegde, A.G.

    2007-01-01

    Radioactive elements uranium, thorium and their daughters are present ubiquitously in the environment and are transferred to man through various pathways. Both, U and Th can cause radiological and toxic hazards. The ingestion dose pathway calculations involve analysis of all kinds of food or edible materials. A large population in India and Asian subcontinent are addicted to commercially available chewing tobacco. This practice is reported to have lead to increased consequences of cancer. Trace elements (Fe, Co, Mn, Zn etc.) are essential but may also prove to be toxic if present in excess. Besides these the hazards of heavy elements like Pb and Cd have also increased in the current polluted environment. In this study most of the commercially available brands of gutkha and chewing tobacco were collected. The radioactive elements U and Th were analyzed in them by Radiochemical Neutron Activation Analysis technique. Trace elements Fe, Co, Mn, Zn, and toxic heavy elements Pb, Cd, Ni etc. were analyzed by Atomic Absorption Spectrophotometry. The levels of Th and U were in the range 0.02-0.11 mg/g and 0.02-0.08 mg/g respectively. The cancer risk due to U, Th, Pb and Cd were calculated and are found to be low. (author)

  12. Delineating miRNA profile induced by chewing tobacco in oral keratinocytes

    Directory of Open Access Journals (Sweden)

    Mohd Younis Bhat

    2017-10-01

    Full Text Available The major established etiologic risk factor for oral cancer is tobacco (chewed, smoked and snuffed forms. Chewing form of tobacco is predominantly used in India making it the leading cause of oral cancer. Despite being one of the leading causes of oral cancer, the molecular alterations induced by chewing tobacco remains largely unclear. Carcinogenic effect of chewing tobacco is through chronic and not acute exposure. To understand the molecular alterations induced by chewing tobacco, we developed a cell line model where non-neoplastic oral keratinocytes were chronically exposed to chewing tobacco for a period of 6 months. This resulted in increased cellular proliferation and invasive ability of normal oral keratinocytes. Using this cellular model we studied the differential expression of miRNAs associated with chewing tobacco and the altered signaling pathways through which the aberrantly expressed miRNAs affect tumorigenesis. miRNA sequencing  was carried out using Illumina HiSeq 2500 platform  which resulted in the identification of 427 annotated miRNAs of which 10 were significantly dysregulated (≥ 4 fold; p-value ≤ 0.05 in tobacco exposed cells compared to untreated parental cells. To study the altered signaling in oral keratinocytes chronically exposed to chewing tobacco, we employed quantitative proteomics to characterize the dysregulated proteins. Integration of miRNA sequencing data with proteomic data resulted in identification of 36 proven protein targets which (≥1.5 fold; p-value ≤ 0.05 showed expression correlation with the 10 significantly dysregulated miRNAs. Pathway analysis of the dysregulated targets revealed enrichment of interferon signaling and mRNA processing related pathways in the chewing tobacco exposed cells. In addition, we also identified 6 novel miRNA in oral keratinocytes chronically exposed to chewing tobacco extract. Our study provides a framework to understand the oncogenic transformation induced by

  13. Description of chewing and food intake over the course of a meal.

    Science.gov (United States)

    Ioakimidis, Ioannis; Zandian, Modjtaba; Eriksson-Marklund, Lisa; Bergh, Cecilia; Grigoriadis, Anastasios; Södersten, Per

    2011-10-24

    While the average frequency of chewing and food intake have been reported before, a detailed description of the pattern of chewing and the cumulative intake of food over the course of a meal have not. In order to achieve this goal, video recording of the maxillary-mandibular region of women eating food from a plate was synchronized with video recording of the plate and computer recording of the weight-loss of the plate. Video recording of chewing correlated strongly with chewing identified by magnetic tracking of jaw displacement in a test with chewing gum at three different frequencies, thus ensuring the validity of video recording of chewing. Weight-loss data were corrected by convolution algorithms, validated against human correction, using sliding window filtering to correct errors with video events as reference points. By use of this method, women ate on average 264 g of food over 114 min, they took an average of 51 mouthfuls during the meal and displayed on average 794 chews with 15 chews per chewing sequence. The number of mouthfuls decreased and the duration of the pauses after each mouthful increased in the middle of the meal and these measures were then restored. The ratio between chewing sequences and subsequent pauses remained stable although the weight of each mouthful decreased by the end of the meal, a measure that is hypothesized to be reflected in a decelerated speed of eating. The method allows this hypothesis to be tested and its implication for clinical intervention to be examined. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Effective field theory dimensional regularization

    International Nuclear Information System (INIS)

    Lehmann, Dirk; Prezeau, Gary

    2002-01-01

    A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed

  15. Effective field theory dimensional regularization

    Science.gov (United States)

    Lehmann, Dirk; Prézeau, Gary

    2002-01-01

    A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed.

  16. Chewing of betel quid: why do health careproviders in Thimphu, Bhutan, do it?

    Science.gov (United States)

    Dorji, Nidup; Pacheun, Oranut; Boonshuyar, Chaweewon

    2012-06-01

    This cross-sectional study aimed to determine the prevalence of betel quid chewing and related factors including general characteristics, behavioral pattern, perception and social influences among health care providers in Thimphu, Bhutan. A self-administered questionnaire was handed to 478 health care providers working in different units of health care centers in Thimphu during June-July 2010. A total of 391 (81.8%) questionnaires were returned. Chi-square test and multiple logistic regression were applied. The prevalence of current betel quid chewers among this group was 26.6%. Males chewed betel quid more than females (29.5%, 23.9% respectively). Forty-two percent of current chewers had no specific reasons for chewing betel quid, although 18.2% declared that they were addicted. Both friends and family members were key persons involved in influencing betel quid chewing. Marital status was significantly associated with betel quid chewing, married health care providers being 2 times more likely to chew betel quid (OR = 2.09, 95% CI = 1.02-4.28) than those of single marital status. Similarly, those coming from West Bhutan, were 2 times more likely to be currently using betel quid (OR = 2.71, 95% CI = 1.32-5.55) than other regions. Health care providers from families with more than half of their members chewing betel quid were 14 times more likely to be currently chewing it (OR = 14.52, 95% CI = 6.02-35.04) than families having none of their members chewing it. Health care smokers were more likely to chew betel quid than non-smoking ones (p-value = 0.012). Also occasional drinkers were 3 times more likely to be currently using betel quid (OR = 3.52, 95% CI = 1.78-6.96). Those who perceived a high barrier to quit chewing were about 2.6 times more likely to be current chewers of betel quid, than those who perceived less of a barrier to quit (OR = 2.62, 95% CI = 1.21-5.67). The present study revealed betel quid chewing prevalence rate of 26.6%. Of the various factors

  17. 75 FR 76006 - Regular Meeting

    Science.gov (United States)

    2010-12-07

    ... FARM CREDIT SYSTEM INSURANCE CORPORATION Regular Meeting AGENCY: Farm Credit System Insurance Corporation Board. ACTION: Regular meeting. SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). Date and Time: The meeting of the Board will be held...

  18. Composition of betel specific chemicals in saliva during betel chewing for the identification of biomarkers

    Science.gov (United States)

    Franke, Adrian A.; Mendez, Ana Joy; Lai, Jennifer F.; Arat-Cabading, Celine; Li, Xingnan; Custer, Laurie J.

    2015-01-01

    Betel nut chewing causes cancer in humans including strong associations with head and neck cancer in Guam. In the search for biomarkers of betel chewing we sought to identify chemicals specific for the 3 most commonly consumed betel preparations in Guam: nut (‘BN’), nut + Piper betle leaf (‘BL’), and betel quid (‘BQ’) consisting of nut+lime+tobacco+Piper betle leaf. Chemicals were extracted from the chewing material and saliva of subjects chewing these betel preparations. Saliva analysis involved protein precipitation with acetonitrile, dilution with formic acid followed by LCMS analysis. Baseline and chewing saliva levels were compared using t-tests and differences between groups were compared by ANOVA; p<0.05 indicated significance. Predominant compounds in chewing material were guvacine, arecoline, guvacoline, arecaidine, chavibetol, and nicotine. In chewing saliva we found significant increases from baseline for guvacine (BN, BQ), arecoline (all groups), guvacoline (BN), arecaidine (all groups), nicotine (BQ), and chavibetol (BL, BQ) and significant differences between all groups for total areca- specific alkaloids, total tobacco-specific alkaloids and chavibetol. From this pilot study, we propose the following chemical patterns as biomarkers: areca alkaloids for BN use, areca alkaloids and chavibetol for BL use, and areca alkaloids plus chavibetol and tobacco-specific alkaloids for BQ use. PMID:25797484

  19. Increased sternocleidomastoid, but not trapezius, muscle activity in response to increased chewing load.

    Science.gov (United States)

    Häggman-Henrikson, Birgitta; Nordh, Erik; Eriksson, Per-Olof

    2013-10-01

    Previous findings, during chewing, that boluses of larger size and harder texture result in larger amplitudes of both mandibular and head-neck movements suggest a relationship between increased chewing load and incremental recruitment of jaw and neck muscles. The present report evaluated jaw (masseter and digastric) and neck [sternocleidomastoid (SCM) and trapezius] muscle activity during the chewing of test foods of different sizes and textures by 10 healthy subjects. Muscle activity was recorded by surface electromyography and simultaneous mandibular and head movements were recorded using an optoelectronic technique. Each subject performed continuous jaw-opening/jaw-closing movements whilst chewing small and large boluses of chewing gum and rubber silicone (Optosil). For jaw opening/jaw closing without a bolus, SCM activity was recorded for jaw opening concomitantly with digastric activity. During chewing, SCM activity was recorded for jaw closing concomitantly with masseter activity. Trapezius activity was present in some, but not all, cycles. For the masseter and SCM muscles, higher activity was seen with larger test foods, suggesting increased demand and recruitment of these muscles in response to an increased chewing load. This result reinforces the previous notion of a close functional connection between the jaw and the neck motor systems in jaw actions and has scientific and clinical significance for studying jaw function and dysfunction. © 2013 Eur J Oral Sci.

  20. Volitional chewing with a conscious effort alters and facilitates swallowing during feeding sequence.

    Science.gov (United States)

    Furuya, J; Hara, A; Nomura, T; Kondo, H

    2014-03-01

    The key objective of mastication is to form a food bolus suitable for smooth swallowing. However, chewing is usually performed without a conscious effort. Poor bolus formation can cause pharyngeal residue and suffocation in elderly individuals with reduced swallowing function. Therefore, chewing with a conscious effort may help the bolus to more easily pass the pharynx. This study aimed to clarify the impact of mastication with a conscious effort on the feeding sequence. Subjects included 25 dentulous volunteers who were informed and provided written consent. Lateral videofluoroscopy was performed during the feeding of solid agar jelly under two conditions: chewing naturally in their usual manner (without volition) and chewing with a conscious effort (with volition). Temporal evaluation was performed for mastication, stage II transport (STII), swallow onset and oropharyngeal transit time. Moreover, bolus volume at swallow onset and subjective evaluation of swallowing easiness were measured. Volitional chewing with a conscious effort lengthened the duration of the chewing sequence before and after STII and delayed the swallow onset despite the fact that the bolus volume in the vallecula and hypopharynx (HYP) had significantly increased. Furthermore, with volition, the bolus transit time from swallow onset in the oral cavity, upper oropharynx and HYP was reduced, and subjective evaluation of swallowing easiness demonstrated significant improvement. These results suggest that volitional chewing with a conscious effort can alter bolus transport and swallowing, resulting in easier swallowing. © 2014 John Wiley & Sons Ltd.

  1. Objective assessment of actual chewing side by measurement of bilateral masseter muscle electromyography.

    Science.gov (United States)

    Yamasaki, Yo; Kuwatsuru, Rika; Tsukiyama, Yoshihiro; Matsumoto, Hiroshi; Oki, Kyosuke; Koyano, Kiyoshi

    2015-12-01

    The aim of this study was to examine the validity of objective assessment of actual chewing side by measurement of electromyographic (EMG) activity of the bilateral masseter muscles upon chewing test foods. The sample consisted of 19 healthy, dentate individuals. The subjects were asked to chew three types of test foods (peanuts, beef jerky, and chewing gum) for 10 strokes on the right side and then on the left side, and instructed to perform maximum voluntary clenching for 3s, three times. EMG activity from the bilateral masseter muscles was recorded. The data were collected in three different days. The root mean square EMG amplitude obtained from the maximum clenching task was used as the maximum voluntary contraction (MVC). Then, the level of amplitude against the MVC (%MVC) was calculated for the right and left sides on each stroke. The side with the larger %MVC value was judged as the chewing side, and the concordance rates (CRs) for the instructed chewing side (ICS) and the judged chewing side (JCS) were calculated. Intraclass correlation coefficients (ICCs) of the CRs were calculated to evaluate the reproducibility of the method. High CRs between the ICS and JCS for each test food were recognized. There were significant ICCs for beef jerky (R=0.761, Pchewing gum (R=0.785, Pchewing side during mastication. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Segmentation and Characterization of Chewing Bouts by Monitoring Temporalis Muscle Using Smart Glasses With Piezoelectric Sensor.

    Science.gov (United States)

    Farooq, Muhammad; Sazonov, Edward

    2017-11-01

    Several methods have been proposed for automatic and objective monitoring of food intake, but their performance suffers in the presence of speech and motion artifacts. This paper presents a novel sensor system and algorithms for detection and characterization of chewing bouts from a piezoelectric strain sensor placed on the temporalis muscle. The proposed data acquisition device was incorporated into the temple of eyeglasses. The system was tested by ten participants in two part experiments, one under controlled laboratory conditions and the other in unrestricted free-living. The proposed food intake recognition method first performed an energy-based segmentation to isolate candidate chewing segments (instead of using epochs of fixed duration commonly reported in research literature), with the subsequent classification of the segments by linear support vector machine models. On participant level (combining data from both laboratory and free-living experiments), with ten-fold leave-one-out cross-validation, chewing were recognized with average F-score of 96.28% and the resultant area under the curve was 0.97, which are higher than any of the previously reported results. A multivariate regression model was used to estimate chew counts from segments classified as chewing with an average mean absolute error of 3.83% on participant level. These results suggest that the proposed system is able to identify chewing segments in the presence of speech and motion artifacts, as well as automatically and accurately quantify chewing behavior, both under controlled laboratory conditions and unrestricted free-living.

  3. Chewing side preference in first and all mastication cycles for hard and soft morsels

    Science.gov (United States)

    Zamanlu, Masumeh; Khamnei, Saeed; SalariLak, Shaker; Oskoee, Siavash Savadi; Shakouri, Seyed Kazem; Houshyar, Yousef; Salekzamani, Yaghoub

    2012-01-01

    Preferred chewing side is a still controversial matter and various methods used have yielded some inconsistencies. The aim of this study is to compare the preference determined in different conditions. Nineteen healthy subjects were offered hard (walnut) and soft (cake) foods, while the electromyography was recorded from their masseter muscles, in 2009 in the Research Center of Physical Medicine and Rehabilitation, Tabriz University of Medical Sciences, Tabriz, Iran. Four occurrences were determined as the side of the first chews/all chews in the two food types, and then analyzed for correlations and agreements. For hard food 73.68% and for soft food 57.89% of the subjects showed preference. The comparison of all chews showed a highly significant preference towards the right side in both food types (p=0.000 & 0.003). There was both correlation and agreement between the first chew preferences in both food types, and an agreement between the first and all chew preferences in the hard food. Therefore, there seems to exist some laterality in mastication, which is more explicit when using hard food and assessing all chews. PMID:22993653

  4. Relationship between chewing ability and cognitive impairment in the rural elderly.

    Science.gov (United States)

    Kim, Eun-Kyong; Lee, Sung Kook; Choi, Youn-Hee; Tanaka, Makiko; Hirotsu, Kimiko; Kim, Hyeon Chang; Lee, Hee-Kyung; Jung, Yun-Sook; Amano, Atsuo

    Relationship between masticatory function and cognitive impairment had been suggested but still understudied. We investigated the association between chewing ability and cognitive impairment among the elderly living in a rural region. A total of 295 elderly individuals aged ≥70 years in a rural city of Korea participated in a cross-sectional study. Trained nurses conducted interviews and assessed chewing ability using gum that changed color based on chewing performance. Cognitive impairment was assessed using the Mini-Mental State Examination for Dementia Screening (MMSE-DS) of Korean vesrsion. Socio-demographic characteristics, activities of daily living (ADL), Mini-Nutritional Assessment (MNA) were also assessed using questionnaires as potential confounders. The mean age of the participants was 81.4 (ranged 70-102) years and 67.8% of them were female. Participants with low chewing ability were significantly older, dependent, and had lower MNA and MMSE-DS scores. The elderly with middle or low chewing ability had significantly higher risk for having cognitive impairment than those with higher chewing ability. Our findings suggest that poor chewing ability is associated with cognitive impairment or dementia in the elderly living in rural area. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Association between masticatory performance using a colour-changeable chewing gum and jaw movement.

    Science.gov (United States)

    Komagamine, Y; Kanazawa, M; Minakuchi, S; Uchida, T; Sasaki, Y

    2011-08-01

    The purpose of this study was to investigate the relationship between masticatory performance as determined using a colour-changeable chewing gum and mandibular movements. Subjects comprised 45 fully dentate adults (23 men, 22 women; mean age, 28·1 years). The gum was chewed for a specified number of chewing strokes (20, 40, 60, 80, 120 or 160 strokes) without any instructions as to chewing side. A colourimeter was used to measure L*, a* and b* values (CIE-L*a*b* colour system) for the chewed gum, then the difference between two colours in the CIE-L*a*b* colour space (ΔE) for each number of chewing strokes was calculated according to a formula. Index of masticatory performance (ΔE60) for each subject was obtained using ΔE for 20, 40, 60, 80, 120 and 160 strokes. Mandibular movements were recorded using an opto-electric system with six degrees of freedom. Twelve parameters of mandibular movements relating to amplitude, duration, velocity and angle were computed for each cycle, and mean values for 10 cycles (from cycle 11 to 20) were calculated separately. Stepwise multiple regression analysis identified maximum closing velocity and closing angle as predictors accounting for 18% of the variation in ΔE60. These results suggest that lower angles of approach to intercuspation and faster speed during closing duration are associated with colour changes in the colour-changeable chewing gum. © 2011 Blackwell Publishing Ltd.

  6. The reasons for betel-quid chewing scale: assessment of factor structure, reliability, and validity.

    Science.gov (United States)

    Little, Melissa A; Pokhrel, Pallav; Murphy, Kelle L; Kawamoto, Crissy T; Suguitan, Gil S; Herzog, Thaddeus A

    2014-06-03

    Despite the fact that betel-quid is one of the most commonly used psychoactive substances worldwide and a major risk-factor for head-and-neck cancer incidence and mortality globally, currently no standardized instrument is available to assess the reasons why individuals chew betel-quid. A measure to assess reasons for chewing betel-quid could help researchers and clinicians develop prevention and treatment strategies. In the current study, we sought to develop and evaluate a self-report instrument for assessing the reasons for chewing betel quid which contributes toward the goal of developing effective interventions to reduce betel quid chewing in vulnerable populations. The current study assessed the factor structure, reliability and convergent validity of the Reasons for Betel-quid Chewing Scale (RBCS), a newly developed 10 item measure adapted from several existing "reasons for smoking" scales. The measure was administered to 351 adult betel-quid chewers in Guam. Confirmatory factor analysis of this measure revealed a three factor structure: reinforcement, social/cultural, and stimulation. Further tests revealed strong support for the internal consistency and convergent validity of this three factor measure. The goal of designing an intervention to reduce betel-quid chewing necessitates an understanding of why chewers chew; the current study makes considerable contributions towards that objective.

  7. Composition of betel specific chemicals in saliva during betel chewing for the identification of biomarkers.

    Science.gov (United States)

    Franke, Adrian A; Mendez, Ana Joy; Lai, Jennifer F; Arat-Cabading, Celine; Li, Xingnan; Custer, Laurie J

    2015-06-01

    Betel nut chewing causes cancer in humans, including strong associations with head and neck cancer in Guam. In the search for biomarkers of betel chewing we sought to identify chemicals specific for the 3 most commonly consumed betel preparations in Guam: nut ('BN'), nut + Piper betle leaf ('BL'), and betel quid ('BQ') consisting of nut + lime + tobacco + Piper betle leaf. Chemicals were extracted from the chewing material and saliva of subjects chewing these betel preparations. Saliva analysis involved protein precipitation with acetonitrile, dilution with formic acid followed by LCMS analysis. Baseline and chewing saliva levels were compared using t-tests and differences between groups were compared by ANOVA; p < 0.05 indicated significance. Predominant compounds in chewing material were guvacine, arecoline, guvacoline, arecaidine, chavibetol, and nicotine. In chewing saliva we found significant increases from baseline for guvacine (BN, BQ), arecoline (all groups), guvacoline (BN), arecaidine (all groups), nicotine (BQ), and chavibetol (BL, BQ), and significant differences between all groups for total areca-specific alkaloids, total tobacco-specific alkaloids and chavibetol. From this pilot study, we propose the following chemical patterns as biomarkers: areca alkaloids for BN use, areca alkaloids and chavibetol for BL use, and areca alkaloids plus chavibetol and tobacco-specific alkaloids for BQ use. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Constituents of areca chewing related to esophageal cancer risk in Taiwanese men.

    Science.gov (United States)

    Wu, M-T; Wu, D-C; Hsu, H-K; Kao, E-L; Lee, J-M

    2004-01-01

    Two most common types of areca chewing are noted in Taiwan: raw betel fruit with Piper betle inflorescence or folded in betel leaf. Piper betle inflorescence contains carcinogens, whereas betel leaf includes anticarcinogenic agents. One hundred and twenty-six esophageal squamous-cell-carcinoma patients and 279 healthy controls, all men, were analyzed. Areca chewers were 4.4 times (95% CI, 2.2-8.8) more likely to develop esophageal cancer than non-chewers. Sixty-five of the patients were areca chewers, of which, 61 (93.9%) chewed areca with Piper betle inflorescence, none chewed it with betel leaf and four (6.1%) chewed both. Of the 24 controls who were chewers, 10 (41.7%), three (12.5%) and 11 (45.8%) chewed areca with Piper betle inflorescence, betel leaf, and both, respectively. Multivariate analysis showed that subjects who chewed areca with Piper betle inflorescence were 24.4 times (95% CI 3.9-154.4) more likely to develop esophageal cancer than those who chewed areca with betel leaf or with both leaf and inflorescence. Our epidemiologic findings suggest parts of the same Piper plant contains carcinogenic and anticarcinogenic substances.

  9. Prevalence of areca nut chewing in the middle school-going children of Indore, India

    Directory of Open Access Journals (Sweden)

    Ashok Khandelwal

    2012-01-01

    Full Text Available Objectives: To assess areca nut chewing habit among middle school-aged children in Indore, India. Areca nut is chewed by itself, and in various scented preparations. It is associated with carcinogenesis, foreign body aspiration in children, and oral submucous fibrosis and may aggravate asthma. Materials and Methods: A retrospective collection of data to evaluate the prevalence of areca nut chewing among 3896 children was done. A simple random sampling was done. Children of both sexes were included in this study. Results: 27.06% of the school-going children (1054/3896 had areca nut chewing habit. More boys chewed areca nut than girls (2:1. 45.42% of school going children of rural area pander to areca nut chewing habit, whereas in urban area 20.09% children are indulged. Government school children are more involved in areca nut chewing habit. 81.02% of the children used sweetened and flavoured form of areca nut. The majority of the users were not aware of harmful effects that the use of areca nut might be harmful for health Conclusion: To diminish the use of areca nut, the Indian Government should consider limiting trade, advertising, and actively communicating its health risks to the public and should deem heavy taxes on it.

  10. Detrimental effects of gum chewing on vigilance in children with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Tucha, Lara; Simpson, William; Evans, Lynsay; Birrel, Laura; Sontag, Thomas A; Lange, Klaus W; Tucha, Oliver

    2010-12-01

    Impairments of attention are cardinal features of attention deficit hyperactivity disorder (ADHD) and can seriously affect the daily life of children with ADHD. Despite effective treatment strategies, there is a need of further treatment options that can be added to available and well established treatments. Further treatment options are needed since available treatments are often time consuming, expensive and limited regarding their external validity. Recent research demonstrated that gum chewing has beneficial effects on cognition including certain aspects of attention. Therefore, gum chewing may benefit children with ADHD in situations requiring particular cognitive efforts. In a crossover study, attentional functioning of 32 children with ADHD and 32 children without the condition was examined. All participants were assessed with chewing gum and without chewing gum. A computerized test was used for the assessment of vigilance and sustained attention. The findings of the present study suggest that gum chewing during task execution has detrimental effects on vigilance of both healthy children and children with ADHD. Sustained attention was not affected by gum chewing. Chewing gum, therefore, appears not to improve attentional performance in children with ADHD. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Regularities in hadron systematics, Regge trajectories and a string quark model

    International Nuclear Information System (INIS)

    Chekanov, S.V.; Levchenko, B.B.

    2006-08-01

    An empirical principle for the construction of a linear relationship between the total angular momentum and squared-mass of baryons is proposed. In order to examine linearity of the trajectories, a rigorous least-squares regression analysis was performed. Unlike the standard Regge-Chew-Frautschi approach, the constructed trajectories do not have non-linear behaviour. A similar regularity may exist for lowest-mass mesons. The linear baryonic trajectories are well described by a semi-classical picture based on a spinning relativistic string with tension. The obtained numerical solution of this model was used to extract the (di)quark masses. (orig.)

  12. Selection of regularization parameter for l1-regularized damage detection

    Science.gov (United States)

    Hou, Rongrong; Xia, Yong; Bao, Yuequan; Zhou, Xiaoqing

    2018-06-01

    The l1 regularization technique has been developed for structural health monitoring and damage detection through employing the sparsity condition of structural damage. The regularization parameter, which controls the trade-off between data fidelity and solution size of the regularization problem, exerts a crucial effect on the solution. However, the l1 regularization problem has no closed-form solution, and the regularization parameter is usually selected by experience. This study proposes two strategies of selecting the regularization parameter for the l1-regularized damage detection problem. The first method utilizes the residual and solution norms of the optimization problem and ensures that they are both small. The other method is based on the discrepancy principle, which requires that the variance of the discrepancy between the calculated and measured responses is close to the variance of the measurement noise. The two methods are applied to a cantilever beam and a three-story frame. A range of the regularization parameter, rather than one single value, can be determined. When the regularization parameter in this range is selected, the damage can be accurately identified even for multiple damage scenarios. This range also indicates the sensitivity degree of the damage identification problem to the regularization parameter.

  13. Ensemble manifold regularization.

    Science.gov (United States)

    Geng, Bo; Tao, Dacheng; Xu, Chao; Yang, Linjun; Hua, Xian-Sheng

    2012-06-01

    We propose an automatic approximation of the intrinsic manifold for general semi-supervised learning (SSL) problems. Unfortunately, it is not trivial to define an optimization function to obtain optimal hyperparameters. Usually, cross validation is applied, but it does not necessarily scale up. Other problems derive from the suboptimality incurred by discrete grid search and the overfitting. Therefore, we develop an ensemble manifold regularization (EMR) framework to approximate the intrinsic manifold by combining several initial guesses. Algorithmically, we designed EMR carefully so it 1) learns both the composite manifold and the semi-supervised learner jointly, 2) is fully automatic for learning the intrinsic manifold hyperparameters implicitly, 3) is conditionally optimal for intrinsic manifold approximation under a mild and reasonable assumption, and 4) is scalable for a large number of candidate manifold hyperparameters, from both time and space perspectives. Furthermore, we prove the convergence property of EMR to the deterministic matrix at rate root-n. Extensive experiments over both synthetic and real data sets demonstrate the effectiveness of the proposed framework.

  14. Peripheral, functional and postural asymmetries related to the preferred chewing side in adults with natural dentition.

    Science.gov (United States)

    Rovira-Lastra, B; Flores-Orozco, E I; Ayuso-Montero, R; Peraire, M; Martinez-Gomis, J

    2016-04-01

    The aim of this cross-sectional study was to determine the preferred chewing side and whether chewing side preference is related to peripheral, functional or postural lateral preferences. One hundred and forty-six adults with natural dentition performed three masticatory assays, each consisting of five trials of chewing three pieces of silicon placed into a latex bag for 20 cycles, either freestyle or unilaterally on the right- or left-hand side. Occlusal contact area in the intercuspal position, maximum bite force, masticatory performance and cycle duration were measured and the lateral asymmetry of these variables was calculated. Laterality tests were performed to determine handedness, footedness, earedness and eyedness as functional preferences, and hand-clasping, arm-folding and leg-crossing as postural lateral preferences. The preferred chewing side was determined using three different methods: assessment of the first chewing cycle for each trial, calculation of the asymmetry index from all cycles and application of a visual analogue scale. Bivariate relationship and multiple linear regression analyses were performed. Among unilateral chewers, 77% of them preferred the right side for chewing. The factors most closely related to the preferred chewing side were asymmetry of bite force, asymmetry of masticatory performance and earedness, which explained up to 16% of the variance. Although several functional or postural lateral preferences seem to be related to the preferred chewing side, peripheral factors such as asymmetry of bite force and of masticatory performance are the most closely related to the preferred chewing side in adults with natural dentition. © 2015 John Wiley & Sons Ltd.

  15. On a new solution of Chew-Low type equations

    International Nuclear Information System (INIS)

    Rerikh, K.V.

    1985-01-01

    The system is investigated of Chew-Low type equations, defined by the crossing symmetry matrix A(1, 1) for S-matrix elements as dfunctions of the uniformmizing variable w, in terms of which this system is a system of nonlinear difference equations. The quadratic Cremona transformation for unknown functions reducing the initial equations to a vey simple form is found. New particular solutions are obtained as functions of variable exp(cw). Existence of the new first integral γ(w) that is an even periodical function of w is estalished. The structure of the general solution depending on γ(w) and the relation of the found particular solutions with the first integral are discussed

  16. Chewing gum does not induce context-dependent memory when flavor is held constant.

    Science.gov (United States)

    Overman, Amy A; Sun, Justin; Golding, Abbe C; Prevost, Darius

    2009-10-01

    This study examined the effect of chewing gum on memory when flavor is held constant. Four separate groups of participants (total n=101) completed a word recall task. At learning and recall, participants either chewed a piece of gum or sucked a sweet. Each participant completed the memory task twice, once with abstract words and once with concrete words. A significant effect of word type (concrete vs. abstract) was found, however recall performance was not improved by matched oral activity at learning and recall. The results cast further doubt on the ability of chewing gum to induce context-dependent memory effects.

  17. Description and evaluation of a net energy intake model as a function of dietary chewing index

    DEFF Research Database (Denmark)

    Jensen, Laura Mie; Markussen, Bo; Nielsen, N. I.

    2016-01-01

    Previously, a linear relationship has been found between net energy intake (NEI) and dietary chewing index (CI) of the diet for different types of cattle. Therefore, we propose to generalize and calibrate this relationship into a new model for direct prediction of NEI by dairy cows from CI values...... a value of 2, implying a constant maximum daily chewing time. The intercept NEI0 in the regression of NEI on CINE may be interpreted as metabolic net energy intake capacity of the cows fed without physical constraints on intake. Based on experimental data, the maximum chewing time was estimated as 1...

  18. Effect of chewing gums containing the probiotic bacterium Lactobacillus reuteri on oral malodour

    DEFF Research Database (Denmark)

    Keller, Mette K; Bardow, Allan; Jensdottir, Thorbjörg

    2012-01-01

    OBJECTIVE: To evaluate the effect of chewing gums containing probiotic bacteria on oral malodour. The null hypothesis was that no difference would be displayed compared with placebo gums. MATERIALS AND METHODS: Twenty-five healthy young adults with self-reported malodorous morning breath completed...... this randomized double-blind placebo-controlled cross-over trial. The design included run-in and wash-out periods interspersed by two intervention periods of 14 days each. The subjects were instructed to chew one gum in the morning and one in the evening containing either two strains of probiotic lactobacilli (L...... lower in the probiotic group compared with the placebo group (p chewing...

  19. Relative bioavailability of methadone hydrochloride administered in chewing gum and tablets

    DEFF Research Database (Denmark)

    Christrup, Lona Louring; Angelo, H.R.; Bonde, J.

    1990-01-01

    Methadone administered in chewing gum in doses of 16.7-22.6 mg to seven patients in a study using an open balanced cross-over design, was compared with 20 mg of methadone given perorally as tablets. There was no significant difference in the AUC/D obtained after administration of chewing gum...... and tablets (p>0.05). It is concluded that the chewing gum formulation should be considered for further testing with respect to suppression of abstinence syndrome in narcotic addicts....

  20. A novel colourimetric technique to assess chewing function using two-coloured specimens: Validation and application.

    Science.gov (United States)

    Schimmel, Martin; Christou, Panagiotis; Miyazaki, Hideo; Halazonetis, Demetrios; Herrmann, François R; Müller, Frauke

    2015-08-01

    Chewing efficiency may be evaluated using cohesive specimen, especially in elderly or dysphagic patients. The aim of this study was to evaluate three two-coloured chewing gums for a colour-mixing ability test and to validate a new purpose built software (ViewGum©). Dentate participants (dentate-group) and edentulous patients with mandibular two-implant overdentures (IOD-group) were recruited. First, the dentate-group chewed three different types of two-coloured gum (gum1-gum3) for 5, 10, 20, 30 and 50 chewing cycles. Subsequently the number of chewing cycles with the highest intra- and inter-rater agreement was determined visually by applying a scale (SA) and opto-electronically (ViewGum©, Bland-Altman analysis). The ViewGum© software determines semi-automatically the variance of hue (VOH); inadequate mixing presents with larger VOH than complete mixing. Secondly, the dentate-group and the IOD-group were compared. The dentate-group comprised 20 participants (10 female, 30.3±6.7 years); the IOD-group 15 participants (10 female, 74.6±8.3 years). Intra-rater and inter-rater agreement (SA) was very high at 20 chewing cycles (95.00-98.75%). Gums 1-3 showed different colour-mixing characteristics as a function of chewing cycles, gum1 showed a logarithmic association; gum2 and gum3 demonstrated more linear behaviours. However, the number of chewing cycles could be predicted in all specimens from VOH (all pchewing efficiency, given an elastic specimen is chewed for 20 cycles and could be recommended for the evaluation of chewing efficiency in a clinical and research setting. Chewing is a complex function of the oro-facial structures and the central nervous system. The application of the proposed assessments of the chewing function in geriatrics or special care dentistry could help visualising oro-functional or dental comorbidities in dysphagic patients or those suffering from protein-energy malnutrition. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All

  1. Trace element evaluation of different varieties of chewing gum by radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Zaidi, J.H.; Arif, M.; Fatima, I.; Ahmad, S.; Qureshi, I.H.

    2000-01-01

    Extensive use of chewing gums, by children in particular, entails the evaluation of trace element contents in them. Radiochemical neutron activation analysis (RNAA) was successfully employed to determine the concentration of 35 trace elements (essential, toxic and nonessential) in eight different brands of chewing gum generally consumed in Rawalpindi/Islamabad area. Comparison of trace element data of our work with literature has been presented. None of the elements detected in the brands of chewing gum examined was found to be present at a level representing a substantial contribution to the total dietary intake of the element. (author)

  2. Relative bioavailability of methadone hydrochloride administered in chewing gum and tablets.

    Science.gov (United States)

    Christrup, L L; Angelo, H R; Bonde, J; Kristensen, F; Rasmussen, S N

    1990-01-01

    Methadone administered in chewing gum in doses of 16.7-22.6 mg to seven patients in a study using an open balanced cross-over design, was compared with 20 mg of methadone given perorally as tablets. There was no significant difference in the AUC/D obtained after administration of chewing gum and tablets (p greater than 0.05). It is concluded that the chewing gum formulation should be considered for further testing with respect to suppression of abstinence syndrome in narcotic addicts.

  3. The influence of religious affiliation on heavy drinking, heavy smoking and heavy betel nut chewing.

    Science.gov (United States)

    Chen, Chiang-Ming

    2014-01-01

    The results of a national survey of determinants of drinking, smoking and betel-nut chewing behaviors are analyzed. The purpose of this paper is to empirically investigate whether drinking, smoking and betel-nut chewing are influenced by a variety of religions based on Taiwan data. Our results suggest that Buddhism, Taoism and practitioners of Chinese folk region are positively associated with heavy betel nut chewing while the religion effects on heavy smoking and drinking are statistically insignificant. Our findings on religion effects in Taiwan can be a valuable reference for comparison in Christian and western countries. © 2013 Elsevier Ltd. All rights reserved.

  4. Antioxidant capacity of chewing stick miswak Salvadora persica.

    Science.gov (United States)

    Mohamed, Saleh A; Khan, Jalaluddin A

    2013-02-21

    Chewing stick (miswak Salvadora persica L.) is an effective tool for oral hygiene. It possessed various biological properties including significant antibacterial and anti-fungal effects. In the present study, we evaluated the antioxidant compounds in miswak. Miswak root was extracted with 80% methanol. Methanol extract as antioxidant was evaluated by using DPPH, ABTS and phosphomolybdenum complex assays and analysis by GC-MS. Peroxidase, catalase and polyphenoloxidase assays were performed for crude extract of miswak root. The methanol extract of miswak contained the highest amount of crude extract among the various solvent extracts. The methanol extract showed a concentration dependent scavenging of DPPH and ABTS radicals with IC50 values 4.8 and 1.6 μg crude extract, respectively. The total antioxidant activities, based on the reduction of molybdenum (VI) to molybdenum (V), increased with increasing crude extract content. The correlation coefficients (R2) between total crude extract and DPPH, ABTS scavenging activities and the formation of phosphomolybdenum complex were 0.97, 0.99 and 0.95, respectively. The GC-MS analysis showed that the methanol extract doesn't contain phenolic and flavonoid compounds or under detected limit. After silylation of methanol extract, three compounds namely 2-furancarboxaldehyde-5-(hydroxymethyl), furan-2-carboxylic acid-3-methyl- trimethylsilyl ester and D-erythro-pentofuranose-2-deoxy-1,3,5-tris-O-(trimethylsilyl) were identified by GC-MS analysis. These furan derivatives as they contain hydroxyl groups could be possessed antioxidant activities. The antioxidant enzymes were also detected in the miswak extract with high level of peroxidase and low level of catalase and polyphenoloxidase. The synergistic actions of antioxidant compounds and antioxidant enzymes make miswak is a good chewing stick for oral hygiene and food purposes.

  5. Dental state and subjective chewing ability of institutionalized elderly people.

    Science.gov (United States)

    Ekelund, R

    1989-02-01

    The purpose of the present study was to investigate the dental state of the elderly, to provide a subjective appraisal of their chewing ability and their inability to eat certain foods because of their poor dental state. The subjects were 480 residents of 24 municipal old people's homes in different parts of Finland. Of the subjects, 153 were men and 327 women, and their ages ranged from 65 to 100 years. The methods used were clinical examination and interview. The clinical examination revealed that 68% of the subjects had no natural teeth, and 22% had neither natural nor artificial teeth. The number of teeth in dentate subjects was small (average 7.6), and the condition mostly poor. Only 2% had any serviceable counterparts. 51% of the subjects wore dentures: 57 subjects in the maxilla alone, three in the mandible alone and 186 in both maxilla and mandible. 41% said that because of their teeth they were unable to eat some foods they would have liked to eat, crisp bread being mentioned most often as such a food (85% of those with chewing difficulties). Edentulous subjects and dentate subjects wearing both maxillary and mandibular dentures said more often than those without dentures that they could eat everything; those without any teeth had most often (59%) to avoid some foods. More attention should be given to the dental condition and the masticatory function of the elderly, especially of those living in institutions, to ensure that they are comfortable physically, psychologically, and socially for the rest of their lives.

  6. Adaptive Regularization of Neural Classifiers

    DEFF Research Database (Denmark)

    Andersen, Lars Nonboe; Larsen, Jan; Hansen, Lars Kai

    1997-01-01

    We present a regularization scheme which iteratively adapts the regularization parameters by minimizing the validation error. It is suggested to use the adaptive regularization scheme in conjunction with optimal brain damage pruning to optimize the architecture and to avoid overfitting. Furthermo......, we propose an improved neural classification architecture eliminating an inherent redundancy in the widely used SoftMax classification network. Numerical results demonstrate the viability of the method...

  7. Changes in jaw muscle activity and the physical properties of foods with different textures during chewing behaviors.

    Science.gov (United States)

    Iguchi, Hiroko; Magara, Jin; Nakamura, Yuki; Tsujimura, Takanori; Ito, Kayoko; Inoue, Makoto

    2015-12-01

    This study aimed to investigate how the activity of the masseter (Mas) and suprahyoid (Hyoid) muscles is influenced by the physical properties of food, how changes in the rheological properties of food differ between different foods during the process of food reduction, and how different salivary flow rates affect bolus-making capability during masticatory behavior in healthy humans. Ten healthy adults participated in this study. Electromyographic (EMG) recordings were obtained from the Mas and Hyoid muscles, and 15 g of steamed rice and rice cake was prepared as test foods. In the ingestion test, the subjects were asked to eat each food in their usual manner. The chewing duration, number of chewing cycles before the first swallow, Mas and Hyoid EMG activity, and chewing cycle time were compared between the foods. Total chewing duration was divided into three substages: early, middle, and late; chewing cycle time and EMG activity per chewing cycle of each substage were compared between the foods and among the substages. In the spitting test, the rheological properties of the bolus at the end of each substage were compared between the foods and among the substages. Finally, stimulated salivary flow rates were measured and the relationships between salivary flow rate and chewing duration, EMG activity, and changes in physical food characteristics were investigated. There were significant differences in total chewing duration and the number of chewing cycles, but not in chewing cycle time, between the foods, which had similar hardness values. The EMG activity levels of the Mas and Hyoid per chewing cycle for the rice cake were significantly greater than for the steamed rice throughout the recording periods. While Mas activity did not change among the substages during chewing, Hyoid EMG activity decreased as chewing progressed. Chewing cycle time also gradually decreased as chewing progressed. The hardness of both foods initially increased, then gradually decreased

  8. Masticatory performance and chewing experience with implant-retained mandibular overdentures

    NARCIS (Netherlands)

    Geertman, ME; Slagter, AP; van't Hof, MA; van Waas, MAJ; Kalk, W

    The relationship between masticatory performance and chewing experience has not yet been explored for patients with implant-retained overdentures. Although many relationships have been found between parameters of objective and subjective oral function, the structure of these relationships remain

  9. The relative bioavailability of loratadine administered as a chewing gum formulation in healthy volunteers

    DEFF Research Database (Denmark)

    Nøhr-Jensen, Lene; Damkier, Per; Bidstrup, Tanja Busk

    2006-01-01

    OBJECTIVE: The aim of this study was to investigate the pharmacokinetics of loratadine and its active metabolite desloratadine after single-dose administration of loratadine as a conventional tablet, orally disintegrating tablet (smelt tablet) and a chewing gum formulation with and without...... of medicated chewing gum without collection of saliva and a 30-mg portion of medicated chewing gum with collection of saliva. Blood samples were taken at predefined sampling points 0-24 h after medication, and the plasma concentrations of loratadine and desloratadine were determined by high-performance liquid...... chromatography. Each study period was separated by a wash-out period of at least 7 days. RESULTS: The mean dose-corrected area under the plasma concentration-time curve extrapolated to infinity AUC(0-infinity) for the chewing gum formulation was statistically significantly increased compared to the tablet...

  10. The management of xerostomia in patients on haemodialysis: comparison of artificial saliva and chewing gum.

    Science.gov (United States)

    Bots, Casper P; Brand, Henk S; Veerman, Enno C I; Valentijn-Benz, Marianne; Van Amerongen, Barbara M; Nieuw Amerongen, Arie V; Valentijn, Robert M; Vos, Pieter F; Bijlsma, Joost A; Bezemer, Pieter D; ter Wee, Piet M

    2005-04-01

    Many patients on haemodialysis (HD) therapy suffer from a dry mouth and xerostomia. This can be relieved by mechanical and gustatory stimulation or palliative care. The aim of this crossover study was to investigate the effect and preferences of a sugar-free chewing gum (Freedent White) and a xanthan gum-based artificial saliva (Xialine) in the management of xerostomia in chronic HD patients. Sixty-five HD patients participated in a 6-week crossover trial. The artificial saliva was rated significantly lower than the chewing gum for effectiveness, taste and a global assessment. No preference differences were found for gender and age, although older subjects rated the artificial saliva with a higher mark. Thirty-nine subjects (60%) preferred chewing gum, 15% (n=10) preferred the artificial saliva. Therefore, both chewing gum and artificial saliva could play an important role in the palliative care of xerostomia in HD patients.

  11. Symmetry of fMRI activation in the primary sensorimotor cortex during unilateral chewing.

    Science.gov (United States)

    Lotze, M; Domin, M; Kordass, B

    2017-05-01

    Functional magnetic resonance imaging (fMRI) is one of the most advanced techniques to analyze the cerebral effects on many behavior aspects of the oral system such as chewing and mastication. Studies on imaging of the cerebral representation of chewing demonstrated differential results with respect to cortical lateralization during unilateral chewing. The aim of our study is to clarify the effects of cerebral responses during unilateral chewing. We used fMRI to compare brain activities during occlusal function in centric occlusion on natural teeth and chewing on a gum located on the right or the left teeth in 15 healthy subjects. Group data were performed by Talairach normalization and in addition by an assignment of activation maxima to individual anatomical landmarks in order to avoid possible loss of spatial preciseness of activation sites by normalization procedures. Evaluation of group data by Talairach normalization revealed representation sites for occlusal movements in bilateral primary (S1) and secondary (S2) somatosensory cortices, primary motor (M1) and premotor cortices, supplementary motor area (SMA) and medial cingulate gyrus, bilateral anterior cerebellar hemispheres and vermis, insula, orbitofrontal cortex, thalamus, and left pallidum. Right-sided chewing showed no differential activation to left-sided chewing, and both showed activation in areas also involved in bilateral occlusion. Both techniques, the one based on group normalization and the one based on an individual evaluation method, revealed remarkable low differences in activation maximum location in the primary motor, the primary and secondary somatosensory cortices, and the anterior cerebellar lobe. All chewing movements tested involved bilateral sensorimotor activation without a significant lateralization of activation intensities. Overall, a general lateralization of occlusion movements to the dominant side could not be verified in the present study. Chewing on the left or on the right

  12. Correlation between the median particle size of chewed frankfurter sausage and almonds during masticatory performance test.

    Science.gov (United States)

    Sumonsiri, P; Thongudomporn, U; Paphangkorakit, J

    2018-04-27

    The correlation between chewing and gastric function is best reflected when the same food type is used during both tests. We proposed frankfurter sausage as test food for masticatory performance as it can also be used in gastric emptying test. The suitability of frankfurter sausage to determine masticatory performance, however, has never been examined. To examine the correlations between the median particle size of frankfurter sausage and almonds (as standard test food) after different numbers of chewing cycles. Twenty-seven subjects performed masticatory performance tests by chewing 2 types of test foods, that is, a piece of almond or 5-g frankfurter sausage cubes placed in a sealed latex bag, for 5 and 15 chewing cycles. For each individual, right and left sides were tested separately. Chewed samples obtained from both sides were pooled. Median particle sizes were determined using a multiple sieving method. Spearman's rank correlation was used to examine any correlation between median particle sizes of the 2 test foods after 5 and 15 cycles. Median particle sizes after 5 and 15 cycles were 2.04 ± 0.87 and 0.95 ± 0.58 mm for almonds and 4.16 ± 0.19 and 3.73 ± 0.25 mm for frankfurter sausage, respectively. Significant correlations were observed between the median particle size of chewed frankfurter sausage after 15 cycles and that of chewed almonds after 5 and 15 cycles (r = .76, P < .01 and r = .52, P = .01, respectively). Frankfurter sausage chewed for 15 cycles may be suitable for the determination of masticatory performance in conjunction with gastric emptying test. © 2018 John Wiley & Sons Ltd.

  13. Caries prevalence and DMF-T index of Papuan’s students with Betel chewing habit

    Directory of Open Access Journals (Sweden)

    Yohanes Tebai

    2009-03-01

    Full Text Available The purpose of the research is to find the extent of caries prevalence and DMF-T index in Papuan’s students with betel chewing habit in Cilaki Dormitory Bandung, 2007. Betel chewing habit is a chewing action of Areca nut (Areca Catechu Linn, Betel leaves (Piper Betel Folia, Betel fruit (Piper Betle Linn, lime talk (Calcium Hydroxide, and after chew to spent out of the mouth. The research is a descriptive research using the survey technique. Research samples are determined by purposive sampling, and a number of 80 samples are collected, consisting of Papuan’s student with betel chewing habit in Bandung between 18-to-30 years of age. Research results indicated that caries prevalence is 98.75% with a DMF-T index of 5.46. The conclusion of the reseach is that the caries prevalence and the DMF-T in Papuan’s student with betel chewing habit in Cilaki Papuan’s Student Dormitory Bandung, 2007, is in the high category.

  14. Effect of Teucrium Polium-Containing Chewing Gum on Reducing Salivary Streptococcus Mutans Counts

    Directory of Open Access Journals (Sweden)

    Somayeh Khoramian Tusi

    2018-06-01

    Full Text Available Introduction: Several studies have reported the antibacterial effect of Teucrium polium extract. In this study, we sought to determine the effect of a chewing gum containing the aqueous extract of Teucrium polium on the level of salivary Streptococcus mutans. Materials and Methods: In this double-blind clinical trial, 20 dental students were randomly assigned to two groups of intervention and control. The intervention group received a chewing gum containing the aqueous extract of Teucrium polium, and the control group received a chewing gum without any plant extract. Each person chewed the gum for 20 minutes three times a day (after each meal for three weeks. Unstimulated saliva samples were collected at the beginning of the experiment before the use of the gums and one day after the final gum consumption. The quantitative polymerase chain reaction (qPCR technique was employed to determine the bacterial level. The colonization rate of Streptococcus mutans was compared between the two groups by using t-test in SPSS, version 21. Results: There was no significant difference between the two groups in terms of Streptococcus mutans counts before the intervention (P>0.05. The consumption of Teucrium polium extract-containing chewing gum in comparison with the placebo gum significantly diminished the number of Streptococcus mutans colonies (P=0.002. Conclusion: The results of this study showed that the chewing gum containing the aqueous extract of Teucrium polium significantly lowered the colonization rate of Streptococcus mutans in human saliva.

  15. Evolution of Muscle Activity Patterns Driving Motions of the Jaw and Hyoid during Chewing in Gnathostomes

    Science.gov (United States)

    Konow, Nicolai; Herrel, Anthony; Ross, Callum F.; Williams, Susan H.; German, Rebecca Z.; Sanford, Christopher P. J.; Gintof, Chris

    2011-01-01

    Although chewing has been suggested to be a basal gnathostome trait retained in most major vertebrate lineages, it has not been studied broadly and comparatively across vertebrates. To redress this imbalance, we recorded EMG from muscles powering anteroposterior movement of the hyoid, and dorsoventral movement of the mandibular jaw during chewing. We compared muscle activity patterns (MAP) during chewing in jawed vertebrate taxa belonging to unrelated groups of basal bony fishes and artiodactyl mammals. Our aim was to outline the evolution of coordination in MAP. Comparisons of activity in muscles of the jaw and hyoid that power chewing in closely related artiodactyls using cross-correlation analyses identified reorganizations of jaw and hyoid MAP between herbivores and omnivores. EMG data from basal bony fishes revealed a tighter coordination of jaw and hyoid MAP during chewing than seen in artiodactyls. Across this broad phylogenetic range, there have been major structural reorganizations, including a reduction of the bony hyoid suspension, which is robust in fishes, to the acquisition in a mammalian ancestor of a muscle sling suspending the hyoid. These changes appear to be reflected in a shift in chewing MAP that occurred in an unidentified anamniote stem-lineage. This shift matches observations that, when compared with fishes, the pattern of hyoid motion in tetrapods is reversed and also time-shifted relative to the pattern of jaw movement. PMID:21705368

  16. The potential of dental-protective chewing gum in oral health interventions.

    Science.gov (United States)

    Ly, Kiet A; Milgrom, Peter; Rothen, Marilynn

    2008-05-01

    The authors provide an overview of chewing gum as a delivery vehicle for dental-protective agents, highlighting xylitol and its potential application in caries-prevention programs for children. The authors reviewed selected clinical investigations and previous reviews associated with chewing gum containing substances such as calcium, bicarbonate, carbamide, chlorhexidine, fluoride and xylitol and their effects on reducing caries. They searched the MEDLINE database by using the key words "dental caries," "oral health," "calcium," "bicarbonate," "carbamide," "chlorhexidine," "fluoride" and "xylitol." Chewing gum is being used as a delivery vehicle for substances such as calcium, bicarbonate, carbamide, chlorhexidine, fluoride and xylitol to improve oral health and reduce caries. These substances exhibit properties that are protective of the oral environment and mediate common oral diseases. The debate for advocating xylitol use in caries prevention is advancing; however, chewing gum use by young schoolchildren in the United States is hindered by choking hazard concerns and lack of specific xylitol dosing recommendations. The use of chewing gum containing dental-protective substances, particularly xylitol, in caries-prevention programs can reduce the tooth decay epidemic. Chewing gum use by children in the school setting should be reconsidered.

  17. Sociocultural Factors that Affect Chewing Behaviors among Betel Nut Chewers and Ex-Chewers on Guam.

    Science.gov (United States)

    Murphy, Kelle L; Herzog, Thaddeus A

    2015-12-01

    Areca nut (betel nut) is chewed by an estimated 10% of the world's population which is equivalent to about 600 million people. It is classified as a Group 1 carcinogen by the World Health Organization (WHO) and has been linked to various types of oral cancer. Chewing areca predominates in South and South East Asia, East Africa, and the Western Pacific and has important social and cultural implications. The purpose of the pilot study was twofold: (1) to examine sociocultural factors that affect why people on Guam chew betel nut, their chewing behaviors, perceptions of risks, probability of changing behaviors, and methods that could be used to reduce use or quit; and (2) to pilot two surveys (one for chewers and one for ex-chewers) to be used in a larger study in the future. A mixed methods design was employed that included surveys pertaining to their status (chewer or ex-chewer) and in-depth interviews. A total of 30 adults participated in this pilot study: adult betel nut chewers (n = 15) and ex-chewers (n = 15). Chewing betel nut is a learned behavior, embedded within the culture, and is viewed as an important cultural identifier. Socially, chewing is viewed as positive. Chewers stated that they were not as aware of health issues; however, ex-chewers stated health reasons for quitting.

  18. Flavor-Enhanced Modulation of Cerebral Blood Flow during Gum Chewing.

    Directory of Open Access Journals (Sweden)

    Yoko Hasegawa

    Full Text Available Flavor perception, the integration of taste and odor, is a critical factor in eating behavior. It remains unclear how such sensory signals influence the human brain systems that execute the eating behavior.WE TESTED CEREBRAL BLOOD FLOW (CBF IN THE FRONTAL LOBES BILATERALLY WHILE SUBJECTS CHEWED THREE TYPES OF GUM WITH DIFFERENT COMBINATIONS OF TASTE AND ODOR: no taste/no odor gum (C-gum, sweet taste/no odor gum (T-gum, and sweet taste/lemon odor gum (TO-gum. Simultaneous recordings of transcranial Doppler ultrasound (TCD and near infrared spectrometer (NIRS were used to measure CBF during gum chewing in 25 healthy volunteers. Bilateral masseter muscle activity was also monitored.We found that subjects could discriminate the type of gum without prior information. Subjects rated the TO-gum as the most flavorful gum and the C-gum as the least flavorful. Analysis of masseter muscle activity indicated that masticatory motor output during gum chewing was not affected by taste and odor. The TCD/NIRS measurements revealed significantly higher hemodynamic signals when subjects chewed the TO-gum compared to when they chewed the C-gum and T-gum.These data suggest that taste and odor can influence brain activation during chewing in sensory, cognitive, and motivational processes rather than in motor control.

  19. Chewing gum benefits sustained attention in the absence of task degradation.

    Science.gov (United States)

    Johnson, Andrew J; Muneem, Mohammed; Miles, Christopher

    2013-07-01

    The present study examined the effect of chewing gum on sustained attention and associated changes in subjective alertness. In a within-participants design, 20 participants completed an extended version of the sustained attention response task (SART: Robertson et al., 1997), both with and without chewing gum. Self-rated measures of alertness, contentedness, and calmness were taken before and after the SART. Chewing gum was associated with improved attentional task performance. This finding was not contingent upon a general decrease in attentional performance and was apparent at all stages of the task. Subjective measures of alertness, contentedness, and calmness were higher following the chewing of gum. Changes in sustained attention co-varied with subjective alertness. The effects of chewing gum on attention and alertness are consistent with past literature and were not contingent on declines in attention. Additionally, we found evidence that gum-induced changes in self-rated alertness and attention are related. We found no support for the proposition that chewing gum can impair attention due to the division of resources.

  20. Chewing ability as a parameter for evaluating the disability of patients with temporomandibular disorders.

    Science.gov (United States)

    Kurita, H; Ohtsuka, A; Kurashina, K; Kopp, S

    2001-05-01

    Restoration of chewing ability is an important aspect of the treatment for temporomandibular disorders (TMDs). However, too little attention has been paid to it. We have used a questionnaire to evaluate and score the chewing ability of TMD patients. The questionnaire includes 19 kinds of food and a chewing task. The patient was asked if she/he experiences difficulty in enjoying eating. The aim of this study was to evaluate correlations between score of chewing ability (SCA) and other symptoms/signs of TMD. Four hundred and seventy-three consecutive TMD patients were evaluated for SCA and other symptoms/signs including temporomandibular joint (TMJ) pain, TMJ and muscle tenderness, TMJ noise (clicking and crepitus), and maximum mouth opening. The relationship between SCA and other symptoms/signs were analysed by multiple regression analysis. Score of chewing ability correlated significantly with TMJ pain and mouth opening capacity but not with TMJ noise and muscle tenderness. Age was a background factor but sex was not. The result of this study suggests that SCA correlated with dysfunction of the TMD patients. This method could be used to evaluate the ability of chewing in assessment of TMD.

  1. The effect of betel nut chewing on contour and object masking.

    Science.gov (United States)

    Ho, Ming-Chou; Wang, Chin-Kun

    2011-11-01

    The betel nut is a common stimulant in many Asian countries. We employed the masking task developed by Enns and Di Lollo (Trends in Cognitive Sciences, 4, 345-352, 1997) to investigate the effects of betel nuts on sensory and attentional processing. In the masking task, participants needed to identify a target that was masked by either a contour mask or an object mask. Sensory processing was assessed by examining target identification in the contour mask condition when the target was presented only centrally, whereas attentional processing was assessed by examining target identification in the object mask condition when the target was presented randomly in either a central or a parafoveal location. The results showed that chewing betel nut and chewing gum produced significant contour masking with a large effect size, similar to the pure control condition, in which participants chewed nothing, and the placebo control condition, in which what participants chewed was disguised. This suggests that neither betel nut nor gum affects sensory processing. Alternatively, betel nut chewing could produce a reduction in object masking for the habitual chewers and the nonchewers, suggesting an effect of betel nut on attentional processing. This concentrated attention was also observed in the placebo control condition; thus, it cannot be exclusively driven by the expectation effect. Also, chewing per se reduced the attentional distribution foveally.

  2. 75 FR 53966 - Regular Meeting

    Science.gov (United States)

    2010-09-02

    ... FARM CREDIT SYSTEM INSURANCE CORPORATION Regular Meeting AGENCY: Farm Credit System Insurance Corporation Board. SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). DATE AND TIME: The meeting of the Board will be held at the offices of the Farm...

  3. Online co-regularized algorithms

    NARCIS (Netherlands)

    Ruijter, T. de; Tsivtsivadze, E.; Heskes, T.

    2012-01-01

    We propose an online co-regularized learning algorithm for classification and regression tasks. We demonstrate that by sequentially co-regularizing prediction functions on unlabeled data points, our algorithm provides improved performance in comparison to supervised methods on several UCI benchmarks

  4. AND KHAT (Catha edulis)

    African Journals Online (AJOL)

    Osondu

    2013-02-21

    Feb 21, 2013 ... Therefore drinking tea in areas with high fluoride levels from water sources should be cautioned to avoid the ... Kingdom has a much higher per capita intake at about 3.5–4.0 ... Ethiopian Journal of Environmental Studies and Management Vol. 6 No.2 ... Ethiopia had already become net self- sufficient in tea ...

  5. AND KHAT (Catha edulis)

    African Journals Online (AJOL)

    Osondu

    2013-02-21

    Feb 21, 2013 ... countries were China, India, Kenya, Srilanka and. Turkey (CTA ... production and processing of tea for both export and domestic ... terms of local consumption and export. It is the ... US$187.215 million (3426.037 million birr.

  6. Determining chewing efficiency using a solid test food and considering all phases of mastication.

    Science.gov (United States)

    Liu, Ting; Wang, Xinmiao; Chen, Jianshe; van der Glas, Hilbert W

    2018-07-01

    Following chewing a solid food, the median particle size, X 50 , is determined after N chewing cycles, by curve-fitting of the particle size distribution. Reduction of X 50 with N is traditionally followed from N ≥ 15-20 cycles when using the artificial test food Optosil ® , because of initially unreliable values of X 50 . The aims of the study were (i) to enable testing at small N-values by using initial particles of appropriate size, shape and amount, and (ii) to compare measures of chewing ability, i.e. chewing efficiency (N needed to halve the initial particle size, N(1/2-Xo)) and chewing performance (X 50 at a particular N-value, X 50,N ). 8 subjects with a natural dentition chewed 4 types of samples of Optosil particles: (1) 8 cubes of 8 mm, border size relative to bin size (traditional test), (2) 9 half-cubes of 9.6 mm, mid-size; similar sample volume, (3) 4 half-cubes of 9.6 mm, and 2 half-cubes of 9.6 mm; reduced particle number and sample volume. All samples were tested with 4 N-values. Curve-fitting with a 2nd order polynomial function yielded log(X 50 )-log(N) relationships, after which N(1/2-Xo) and X 50,N were obtained. Reliable X 50 -values are obtained for all N-values when using half-cubes with a mid-size relative to bin sizes. By using 2 or 4 half-cubes, determination of N(1/2-Xo) or X 50,N needs less chewing cycles than traditionally. Chewing efficiency is preferable over chewing performance because of a comparison of inter-subject chewing ability at the same stage of food comminution and constant intra-subject and inter-subject ratios between and within samples respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Collation of chewing efficiency and dentures with diverse occlusal schemes

    Directory of Open Access Journals (Sweden)

    Vijay Kumar Peddinti

    2017-01-01

    Full Text Available Background: Rehabilitation of an edentulous patient nurtures satisfaction and this lies in the chewing ability provided by the prosthesis. Aim: To evaluate and compare the masticatory efficiencies of complete dentures with different occlusal schemes. Materials and Methods: Fourteen completely edentulous patients from the age group of 50-70 years were selected according to the inclusion criteria followed in this study. The dentures were made with three different occlusal schemes, i.e., anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion and stored in water till the date of denture insertion. Post-insertion instructions were given to the patients at the time of delivery of the dentures. Patients were recalled after seven days and then masticatory efficiency was performed. The test was performed using boiled peanuts and Sieve system. Statistical Analysis: One-way analysis of variance (ANOVA test and unpaired t-test were carried out. Results: The obtained masticatory efficiency values with anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion LO were analyzed using one-way ANOVA test and unpaired “t” test. The tests showed that lingualized scheme had highest masticatory efficiency. Conclusion: Within the scope of this study, it can be concluded that the masticatory efficiency will be generally higher in patients provided with complete dentures fabricated using the lingualized occlusal scheme.

  8. Design, formulation and evaluation of caffeine chewing gum.

    Science.gov (United States)

    Aslani, Abolfazl; Jalilian, Fatemeh

    2013-01-01

    Caffeine which exists in drinks such as coffee as well as in drug dosage forms in the global market is among the materials that increase alertness and decrease fatigue. Compared to other forms of caffeine, caffeine gum can create faster and more prominent effects. In this study, the main goal is to design a new formulation of caffeine gum with desirable taste and assess its physicochemical properties. Caffeine gum was prepared by softening of gum bases and then mixing with other formulation ingredients. To decrease the bitterness of caffeine, sugar, aspartame, liquid glucose, sorbitol, manitol, xylitol, and various flavors were used. Caffeine release from gum base was investigated by mechanical chewing set. Content uniformity test was also performed on the gums. The gums were evaluated in terms of organoleptic properties by the Latin-Square design at different stages. After making 22 formulations of caffeine gums, F11 from 20 mg caffeine gums and F22 from 50 mg caffeine gums were chosen as the best formulation in organoleptic properties. Both types of gum released about 90% of their own drug content after 30 min. Drug content of 20 and 50 mg caffeine gum was about 18.2-21.3 mg and 45.7-53.6 mg respectively. In this study, 20 and 50 mg caffeine gums with suitable and desirable properties (i.e., good taste and satisfactory release) were formulated. The best flavor for caffeine gum was cinnamon. Both kinds of 20 and 50 mg gums succeeded in content uniformity test.

  9. New records and a new species of chewing lice (Phthiraptera, Amblycera, Ischnocera found on Columbidae (Columbiformes in Pakistan

    Directory of Open Access Journals (Sweden)

    Saima Naz

    2012-03-01

    Full Text Available The chewing lice (Phthiraptera of Columbidae (Columbiformes from Pakistan are studied. Six species of chewing lice with new host records are recorded and one new species of the genus Colpocephalum is described from Columba livia in the Karachi region. All the columbid chewing lice from Pakistan are keyed out and the new species is illustrated and compared with the closest allied species.

  10. Continuum-regularized quantum gravity

    International Nuclear Information System (INIS)

    Chan Huesum; Halpern, M.B.

    1987-01-01

    The recent continuum regularization of d-dimensional Euclidean gravity is generalized to arbitrary power-law measure and studied in some detail as a representative example of coordinate-invariant regularization. The weak-coupling expansion of the theory illustrates a generic geometrization of regularized Schwinger-Dyson rules, generalizing previous rules in flat space and flat superspace. The rules are applied in a non-trivial explicit check of Einstein invariance at one loop: the cosmological counterterm is computed and its contribution is included in a verification that the graviton mass is zero. (orig.)

  11. Chewing Prevents Stress-Induced Hippocampal LTD Formation and Anxiety-Related Behaviors: A Possible Role of the Dopaminergic System

    Science.gov (United States)

    Koizumi, So; Onozuka, Minoru

    2015-01-01

    The present study examined the effects of chewing on stress-induced long-term depression (LTD) and anxiogenic behavior. Experiments were performed in adult male rats under three conditions: restraint stress condition, voluntary chewing condition during stress, and control condition without any treatments except handling. Chewing ameliorated LTD development in the hippocampal CA1 region. It also counteracted the stress-suppressed number of entries to the center region of the open field when they were tested immediately, 30 min, or 60 min after restraint. At the latter two poststress time periods, chewing during restraint significantly increased the number of times of open arm entries in the elevated plus maze, when compared with those without chewing. The in vivo microdialysis further revealed that extracellular dopamine concentration in the ventral hippocampus, which is involved in anxiety-related behavior, was significantly greater in chewing rats than in those without chewing from 30 to 105 min after stress exposure. Development of LTD and anxiolytic effects ameliorated by chewing were counteracted by administering the D1 dopamine receptor antagonist SCH23390, which suggested that chewing may activate the dopaminergic system in the ventral hippocampus to suppress stress-induced anxiogenic behavior. PMID:26075223

  12. Chewing prevents stress-induced hippocampal LTD formation and anxiety-related behaviors: a possible role of the dopaminergic system.

    Science.gov (United States)

    Ono, Yumie; Koizumi, So; Onozuka, Minoru

    2015-01-01

    The present study examined the effects of chewing on stress-induced long-term depression (LTD) and anxiogenic behavior. Experiments were performed in adult male rats under three conditions: restraint stress condition, voluntary chewing condition during stress, and control condition without any treatments except handling. Chewing ameliorated LTD development in the hippocampal CA1 region. It also counteracted the stress-suppressed number of entries to the center region of the open field when they were tested immediately, 30 min, or 60 min after restraint. At the latter two poststress time periods, chewing during restraint significantly increased the number of times of open arm entries in the elevated plus maze, when compared with those without chewing. The in vivo microdialysis further revealed that extracellular dopamine concentration in the ventral hippocampus, which is involved in anxiety-related behavior, was significantly greater in chewing rats than in those without chewing from 30 to 105 min after stress exposure. Development of LTD and anxiolytic effects ameliorated by chewing were counteracted by administering the D1 dopamine receptor antagonist SCH23390, which suggested that chewing may activate the dopaminergic system in the ventral hippocampus to suppress stress-induced anxiogenic behavior.

  13. Chewing Prevents Stress-Induced Hippocampal LTD Formation and Anxiety-Related Behaviors: A Possible Role of the Dopaminergic System

    Directory of Open Access Journals (Sweden)

    Yumie Ono

    2015-01-01

    Full Text Available The present study examined the effects of chewing on stress-induced long-term depression (LTD and anxiogenic behavior. Experiments were performed in adult male rats under three conditions: restraint stress condition, voluntary chewing condition during stress, and control condition without any treatments except handling. Chewing ameliorated LTD development in the hippocampal CA1 region. It also counteracted the stress-suppressed number of entries to the center region of the open field when they were tested immediately, 30 min, or 60 min after restraint. At the latter two poststress time periods, chewing during restraint significantly increased the number of times of open arm entries in the elevated plus maze, when compared with those without chewing. The in vivo microdialysis further revealed that extracellular dopamine concentration in the ventral hippocampus, which is involved in anxiety-related behavior, was significantly greater in chewing rats than in those without chewing from 30 to 105 min after stress exposure. Development of LTD and anxiolytic effects ameliorated by chewing were counteracted by administering the D1 dopamine receptor antagonist SCH23390, which suggested that chewing may activate the dopaminergic system in the ventral hippocampus to suppress stress-induced anxiogenic behavior.

  14. Is the side with the best masticatory performance selected for chewing?

    Science.gov (United States)

    Rovira-Lastra, Bernat; Flores-Orozco, Elan Ignacio; Salsench, Juan; Peraire, Maria; Martinez-Gomis, Jordi

    2014-12-01

    This study assessed the degree of relationship between masticatory laterality and lateral asymmetry of masticatory performance using silicon pieces enclosed in a latex bag. Forty-two young adults with natural dentition participated in this cross-sectional, observational study. They performed four different masticatory assays, each consisting of five trials of chewing three pieces of silicon for 20 cycles. In one assay, they were asked to masticate unbagged silicon free-style, whilst in the three other assays they were asked to masticate bagged silicon free-style, unilaterally on the right-hand side and unilaterally on the left-hand side. The preferred chewing side was determined by calculating the asymmetry index for both the free-style assays. Masticatory performance was determined by sieving the silicon particles and the cycle duration was also recorded. Data were analysed using independent samples or paired t-test and linear regression. Masticatory function using the bagged silicon was similar to that using the unbagged silicon. A significant and positive relationship was observed between the preferred chewing side expressed as the asymmetry index and the side with better masticatory performance. Alternate unilateral chewers demonstrated better masticatory performance than unilateral chewers. However, when free-style and unilateral chewing were compared for each subject, unilateral chewing was found to be as efficient as - or even more efficient than - free-style chewing. There is a positive association between the preferred chewing side and the more efficient side. Alternate unilateral mastication per se does not promote better masticatory performance than consistently unilateral mastication. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Endoscopic evaluation of food bolus formation and its relationship with the number of chewing cycles.

    Science.gov (United States)

    Fukatsu, H; Nohara, K; Kotani, Y; Tanaka, N; Matsuno, K; Sakai, T

    2015-08-01

    It is known that solid food is transported to the pharynx actively in parallel to it being crushed by chewing and mixed with saliva in the oral cavity. Therefore, food bolus formation should be considered to take place from the oral cavity to the pharynx. In previous studies, the chewed food was evaluated after the food had been removed from the oral cavity. However, it has been pointed out that spitting food out of the oral cavity interferes with natural food bolus formation. Therefore, we observed food boluses immediately before swallowing using an endoscope to establish a method to evaluate the food bolus-forming function, and simultaneously performed endoscopic evaluation of food bolus formation and its relationship with the number of chewing cycles. The subject was inserted the endoscope nasally and instructed to eat two coloured samples of boiled rice simultaneously in two ingestion conditions ('as usual' and 'chewing well'). The condition of the food bolus was graded into three categories for each item of grinding, mixing and aggregation and scored 2, 1 and 0. The score of aggregation was high under both ingestion conditions. The scores of grinding and mixing tended to be higher in subjects with a high number of chewing cycles, and the score of aggregation was high regardless of the number of chewing cycles. It was suggested that food has to be aggregated, even though the number of chewing cycles is low and the food is not ground or mixed for a food bolus to reach the swallowing threshold. © 2015 John Wiley & Sons Ltd.

  16. Chewing reduces sympathetic nervous response to stress and prevents poststress arrhythmias in rats.

    Science.gov (United States)

    Koizumi, So; Minamisawa, Susumu; Sasaguri, Kenichi; Onozuka, Minoru; Sato, Sadao; Ono, Yumie

    2011-10-01

    Reducing stress is important in preventing sudden death in patients with cardiovascular disease, as stressful events may cause autonomic imbalance and trigger fatal arrhythmias. Since chewing has been shown to inhibit stress-induced neuronal responses in the hypothalamus, we hypothesized that chewing could ameliorate stress-induced autonomic imbalance and prevent arrhythmias. To test this hypothesis, we analyzed changes in radiotelemetered electrocardiograms in rats that were allowed to chew a wooden stick during a 1-h period of immobilization stress. Chewing significantly reduced the occurrence of ventricular premature beats (VPBs) and complex ventricular ectopy after immobilization and prevented stress-induced prolongation of the QT interval of VPBs throughout the 10-h experimental period. It also prevented prolongation of the QRS complex and fluctuations in the QT interval in normal sinus rhythm beats preceding VPBs during both immobilization and in the poststress period. Fast Fourier transform-based spectral analysis of heart-rate variability further showed that chewing significantly inhibited the stress-induced increase in the power ratio of low-to-high frequency activity (LF/HF: a marker of sympathetic activity) during immobilization and in addition was associated with blunting of the stress-induced increase in plasma noradrenaline observed at the termination of immobilization. Similar suppressive effects on the occurrence of VPBs and the LF/HF were observed in rats that were administered the β-adrenergic blocker propranolol before immobilization. These results indicate that chewing can ameliorate sympathetic hyperactivity during stress and prevent poststress arrhythmias and suggest that chewing may provide a nonpharmacological and cost-effective treatment option for patients with a high risk of stress-induced fatal arrhythmia.

  17. Remineralization of enamel subsurface lesions by chewing gum with added calcium.

    Science.gov (United States)

    Cai, Fan; Shen, Peiyan; Walker, Glenn D; Reynolds, Coralie; Yuan, Yi; Reynolds, Eric C

    2009-10-01

    Chewing sugar-free gum has been shown to promote enamel remineralization. Manufacturers are now adding calcium to the gum in an approach to further promote enamel remineralization. The aim of this study was to compare the remineralization efficacy of four sugar-free chewing gums, two containing added calcium, utilizing a double-blind, randomized, crossover in situ model. The sugar-free gums were: Trident Xtra Care, Orbit Professional, Orbit and Extra. Ten subjects wore removable palatal appliances with four human-enamel half-slab insets containing subsurface demineralized lesions. For four times a day for 14 consecutive days subjects chewed one of the chewing gums for 20min. After each treatment the enamel slabs were removed, paired with their respective demineralized control slabs, embedded, sectioned and mineral level determined by microradiography. After 1-week rest the subjects chewed another of the four gums and this was repeated until each subject had used the four gum products. Chewing with Trident Xtra Care resulted in significantly higher remineralization (20.67+/-1.05%) than chewing with Orbit Professional (12.43+/-0.64%), Orbit (9.27+/-0.59%) or Extra (9.32+/-0.35%). The form of added calcium in Trident Xtra Care was CPP-ACP and that in Orbit Professional calcium carbonate with added citric acid/citrate for increased calcium solubility. Although saliva analysis confirmed release of the citrate and calcium from the Orbit Professional gum the released calcium did not result in increased enamel remineralization over the normal sugar-free gums. These results highlight the importance of calcium ion bioavailability in the remineralization of enamel subsurface lesions in situ.

  18. Monitoring and assessment of ingestive chewing sounds for prediction of herbage intake rate in grazing cattle.

    Science.gov (United States)

    Galli, J R; Cangiano, C A; Pece, M A; Larripa, M J; Milone, D H; Utsumi, S A; Laca, E A

    2018-05-01

    Accurate measurement of herbage intake rate is critical to advance knowledge of the ecology of grazing ruminants. This experiment tested the integration of behavioral and acoustic measurements of chewing and biting to estimate herbage dry matter intake (DMI) in dairy cows offered micro-swards of contrasting plant structure. Micro-swards constructed with plastic pots were offered to three lactating Holstein cows (608±24.9 kg of BW) in individual grazing sessions (n=48). Treatments were a factorial combination of two forage species (alfalfa and fescue) and two plant heights (tall=25±3.8 cm and short=12±1.9 cm) and were offered on a gradient of increasing herbage mass (10 to 30 pots) and number of bites (~10 to 40 bites). During each grazing session, sounds of biting and chewing were recorded with a wireless microphone placed on the cows' foreheads and a digital video camera to allow synchronized audio and video recordings. Dry matter intake rate was higher in tall alfalfa than in the other three treatments (32±1.6 v. 19±1.2 g/min). A high proportion of jaw movements in every grazing session (23 to 36%) were compound jaw movements (chew-bites) that appeared to be a key component of chewing and biting efficiency and of the ability of cows to regulate intake rate. Dry matter intake was accurately predicted based on easily observable behavioral and acoustic variables. Chewing sound energy measured as energy flux density (EFD) was linearly related to DMI, with 74% of EFD variation explained by DMI. Total chewing EFD, number of chew-bites and plant height (tall v. short) were the most important predictors of DMI. The best model explained 91% of the variation in DMI with a coefficient of variation of 17%. Ingestive sounds integrate valuable information to remotely monitor feeding behavior and predict DMI in grazing cows.

  19. New regular black hole solutions

    International Nuclear Information System (INIS)

    Lemos, Jose P. S.; Zanchin, Vilson T.

    2011-01-01

    In the present work we consider general relativity coupled to Maxwell's electromagnetism and charged matter. Under the assumption of spherical symmetry, there is a particular class of solutions that correspond to regular charged black holes whose interior region is de Sitter, the exterior region is Reissner-Nordstroem and there is a charged thin-layer in-between the two. The main physical and geometrical properties of such charged regular black holes are analyzed.

  20. Regular variation on measure chains

    Czech Academy of Sciences Publication Activity Database

    Řehák, Pavel; Vitovec, J.

    2010-01-01

    Roč. 72, č. 1 (2010), s. 439-448 ISSN 0362-546X R&D Projects: GA AV ČR KJB100190701 Institutional research plan: CEZ:AV0Z10190503 Keywords : regularly varying function * regularly varying sequence * measure chain * time scale * embedding theorem * representation theorem * second order dynamic equation * asymptotic properties Subject RIV: BA - General Mathematics Impact factor: 1.279, year: 2010 http://www.sciencedirect.com/science/article/pii/S0362546X09008475

  1. Manifold Regularized Correlation Object Tracking

    OpenAIRE

    Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling

    2017-01-01

    In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped fr...

  2. On geodesics in low regularity

    Science.gov (United States)

    Sämann, Clemens; Steinbauer, Roland

    2018-02-01

    We consider geodesics in both Riemannian and Lorentzian manifolds with metrics of low regularity. We discuss existence of extremal curves for continuous metrics and present several old and new examples that highlight their subtle interrelation with solutions of the geodesic equations. Then we turn to the initial value problem for geodesics for locally Lipschitz continuous metrics and generalize recent results on existence, regularity and uniqueness of solutions in the sense of Filippov.

  3. Condition Number Regularized Covariance Estimation.

    Science.gov (United States)

    Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

    2013-06-01

    Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the "large p small n " setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required.

  4. Condition Number Regularized Covariance Estimation*

    Science.gov (United States)

    Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

    2012-01-01

    Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the “large p small n” setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required. PMID:23730197

  5. Effects of Chewing Different Flavored Gums on Salivary Flow Rate and pH.

    Science.gov (United States)

    Karami Nogourani, Maryam; Janghorbani, Mohsen; Kowsari Isfahan, Raha; Hosseini Beheshti, Mozhgan

    2012-01-01

    Chewing gum increases salivary flow rate (SFR) and pH, but differences in preferences of gum flavor may influence SFR and pH. The aim of this paper was to assess the effect of five different flavors of sucrose-free chewing gum on the salivary flow rate and pH in healthy dental students in Isfahan, Iran. Fifteen (7 men and 8 women) healthy dental student volunteers collected unstimulated saliva and then chewed one of five flavored gums for 6 min. The whole saliva was collected and assessed for 6 consecutive days. After unstimulated saliva was collected, stimulated saliva was collected at interval of 0-1, 1-3, and 3-6 minutes after the start of different flavored chewing gums. The SFR and salivary pH were measured. The SFR increased in all five flavored gums at 1, 3, and 6 minutes after start of chewing gums (P salivary pH. Gum flavored can affect the SFR and pH and special flavors can be advised for different individuals according to their oral conditions.

  6. Role of glucose in chewing gum-related facilitation of cognitive function.

    Science.gov (United States)

    Stephens, Richard; Tunney, Richard J

    2004-10-01

    This study tests the hypothesis that chewing gum leads to cognitive benefits through improved delivery of glucose to the brain, by comparing the cognitive performance effects of gum and glucose administered separately and together. Participants completed a battery of cognitive tests in a fully related 2 x 2 design, where one factor was Chewing Gum (gum vs. mint sweet) and the other factor was Glucose Co-administration (consuming a 25 g glucose drink vs. consuming water). For four tests (AVLT Immediate Recall, Digit Span, Spatial Span and Grammatical Transformation), beneficial effects of chewing and glucose were found, supporting the study hypothesis. However, on AVLT Delayed Recall, enhancement due to chewing gum was not paralleled by glucose enhancement, suggesting an alternative mechanism. The glucose delivery model is supported with respect to the cognitive domains: working memory, immediate episodic long-term memory and language-based attention and processing speed. However, some other mechanism is more likely to underlie the facilitatory effect of chewing gum on delayed episodic long-term memory.

  7. Gum chewing improves swallow frequency and latency in Parkinson patients: a preliminary study.

    Science.gov (United States)

    South, Angela R; Somers, Stephanie M; Jog, Mandar S

    2010-04-13

    Reduced swallowing frequency affects secretion management in Parkinson disease (PD). Gum chewing increases saliva flow and swallow frequency. This study uses chewing gum to modify swallow frequency and latency between swallows in patients with PD. 1) Assess the frequency and latency of swallow at baseline (BL), during gum chewing (GC), and post gum chewing (PGC) for participants with PD (stage 2-4) nonsymptomatic for prandial dysphagia; and 2) assess carryover after gum is expectorated. Twenty participants were studied across 3 tasks, each of 5 minutes in duration: BL, GC, and PGC. Respiratory and laryngeal signals were continuously recorded using PowerLab (version 5.5.5; ADI Instruments, Castle Hill, Australia). Frequency and latency of swallow events were calculated. Differences (analysis of variance) are reported for frequency (p Parkinson disease. This study provides Class III evidence that chewing gum increases swallow frequency and decreases latency of swallowing in an experiment in patients with stage 2 to 4 Parkinson disease who are nonsymptomatic for significant prandial dysphagia.

  8. Effects of caffeinated chewing gum on muscle pain during submaximal isometric exercise in individuals with fibromyalgia.

    Science.gov (United States)

    Umeda, Masataka; Kempka, Laura; Weatherby, Amy; Greenlee, Brennan; Mansion, Kimberly

    2016-04-01

    Physical activity is important to manage symptom of fibromyalgia (FM); however, individuals with FM typically experience augmented muscle pain during exercise. This study examined the effects of caffeinated chewing gum on exercise-induced muscle pain in individuals with FM. This study was conducted with a double-blind, placebo-controlled, cross-over design. Twenty-three patients with FM completed a caffeine condition where they consumed a caffeinated chewing gum that contains 100mg of caffeine, and a placebo condition where they consumed a non-caffeinated chewing gum. They completed isometric handgrip exercise at 25% of their maximal strength for 3 min, and muscle pain rating (MPR) was recorded every 30s during exercise. Clinical pain severity was assessed in each condition using a pain questionnaire. The order of the two conditions was randomly determined. MPR increased during exercise, but caffeinated chewing gum did not attenuate the increase in MPR compared to placebo gum. Clinical pain severity was generally associated with the average MPR and the caffeine effects on MPR, calculated as difference in the average MPR between the two conditions. The results suggest that more symptomatic individuals with FM may experience greater exercise-induced muscle pain, but benefit more from caffeinated chewing gum to reduce exercise-induced muscle pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Relationship between stage II transport and number of chewing strokes as mastication progresses.

    Science.gov (United States)

    Yamashita, Shuichiro; Sugita, Daisuke; Matsuo, Koichiro

    2013-10-02

    As mastication progresses, little is known about the occurrence of the stage II transport (oro-pharyngeal bolus transport). This study aimed to investigate the relationship between stage II transport and bolus aggregation in the pharynx and the number of chewing strokes. Twenty-five clinical residents with natural dentitions were recruited. The subjects were asked to chew gummy jelly with their preferred rhythm and to swallow the bolus at their preferred timing. To investigate stage II transport and bolus aggregation in the pharynx, a transnasal endoscope was used. The number of chewing strokes was measured by electromyographic activity from the masseter muscle. The mean numbers of chewing strokes of pre-stage II transport and post-stage II transport were 29.8 and 8.1, respectively; the difference was significant (pchewing strokes of pre-stage II transport to that of post-stage II transport was 4.0 to 1.0. This study showed that stage II transport started at four-fifths of the way along the progress of mastication, and that stage II transport and bolus aggregation in the pharynx are related to the number of chewing strokes. © 2013. Published by Elsevier Inc. All rights reserved.

  10. Reproductive performance and weaning success in fur-chewing chinchillas (Chinchilla lanigera).

    Science.gov (United States)

    Galeano, María G; Cantarelli, Verónica I; Ruiz, Rubén D; Fiol de Cuneo, Marta; Ponzio, Marina F

    2014-09-01

    In captive chinchillas, one of the most challenging behavioral problems is the development of a stress-related abnormal repetitive behavior (ARB) known as "fur-chewing". We investigated whether there is a relationship between the severity of fur-chewing behavior and reproductive function in male and female chinchillas. Regardless of the severity of abnormal behavior, fur-chewing males did not show significant differences in seminal quality (sperm concentration, motility and viability; integrity of sperm membrane and acrosome) and the response to the process of semen collection (the number of stimuli needed to achieve ejaculation) when compared to those with normal behavior. Also, females showing normal or fur-chewing behavior presented similar reproductive performance in terms of number of litters per female per year and litter size. However, pup survival rate was lower (p=0.05) in fur-chewing females than in normal females. These results seem to be consistent with data suggesting non-significant effects of ARBs on reproductive performance. Copyright © 2014 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  11. Effects of therapy on masseter activity and chewing kinematics in patients with unilateral posterior crossbite.

    Science.gov (United States)

    Piancino, Maria Grazia; Falla, Deborah; Merlo, Andrea; Vallelonga, Teresa; de Biase, Corrado; Dalessandri, Domenico; Debernardi, Cesare

    2016-07-01

    To describe the effects of therapy on masseter activity and chewing kinematic in patients with unilateral posterior crossbite (UPC). Fifty children (age: mean ± SD: 9.1 ± 2.3 years) with UPC (34 on the right side, 16 on the left side) and twenty children (age: 9.5 ± 2.6 years) with normal occlusion were selected for the study. The mandibular motion and the muscular activity during chewing soft and hard boli were simultaneously recorded, before and after correction with function generating bite, after a mean treatment time of 7.3 ± 2.4 months plus the retention time of 5-6 months. The percentage of reverse cycles and the percent difference between ipsilateral and contralateral peaks of the masseter electromyography envelopes were computed. Before therapy, the percentage of reverse cycles during chewing on the crossbite side was greater in patients than in controls (Preverse chewing patterns. The previous altered muscular activation corresponded to the altered kinematics of reverse chewing cycles that might be considered a useful indicator of the severity of the masticatory function involvement. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Chewing cycles in 4- and 5-year-old normal children: an index of eating efficacy.

    Science.gov (United States)

    Schwartz, J L; Niman, C W; Gisel, E G

    1984-03-01

    Eating movements in the preschool child undergo change between the ages of 2 and 5 years. There is a lack of objective clinical data from normal children against which eating movements of feeding-impaired children can be compared. In this study, chewing movements were measured to complement tongue movements described in an earlier study. The movements were monitored in 40 children: 20 were four years old and 20 were five years old. Each group had ten boys and ten girls. Chewing movements were measured by time (sec), number of cycles, and a time/cycle ratio. A chewing cycle was defined as an upward and downward movement of the chin. Total time from the moment food was placed in the mouth until the final swallow occurred was divided by the number of cycles counted for the same period. Age and sex did not affect time, cycles, or the time/cycle ratio. However, the measures were strongly affected by the type of food eaten. These findings suggest that the texture of food strongly influences both the number of chewing cycles performed and the time used for chewing. The occupational therapist administering eating evaluations to children should carefully choose the foods offered for initial evaluations and use the same food consistently during re-evaluations.

  13. Brief communication: effect of coca-leaf chewing on salivary progesterone assays.

    Science.gov (United States)

    Vitzthum, V J; von Dornum, M; Ellison, P T

    1993-12-01

    Although there is evidence for reduced fertility in Andean and Himalayan populations at higher altitudes, factors other than hypoxia may be primarily responsible. A valuable approach in the investigation of these fertility determinants is the use of salivary steroid assays. However, coca-leaf chewing--a ubiquitous practice among high altitude Andean populations--has negative consequences for the accurate measurement of ovarian steroids. This report evaluates the effects of coca-leaf chewing on assays of salivary progesterone. Study participants include naive and habitual users of coca leaf from La Paz and El Alto, Bolivia. Approximately 300 saliva samples were collected immediately before, during, and after coca-leaf chewing. The series includes samples with and without the alkaloid enhancer typically used by coca-leaf chewers. Coca chewing produces false salivary progesterone values that mimic luteal phase values. On the basis of this study, an appropriate protocol is developed for the collection of salivary samples in coca-leaf chewing populations. These results verify the feasibility of salivary assays, even for very difficult field conditions, and highlight the necessity of establishing suitable collection procedures before full field implementation of saliva sampling.

  14. Tobacco (kretek) smoking, betel quid chewing and risk of oral cancer in a selected Jakarta population.

    Science.gov (United States)

    Amtha, Rahmi; Razak, Ishak Abduk; Basuki, Bastaman; Roeslan, Boedi Oetomo; Gautama, Walta; Puwanto, Denny Joko; Ghani, Wan Maria Nabillah; Zain, Rosnah Binti

    2014-01-01

    This study aimed to determine the association between tobacco consumption (kretek) and betel quid chewing with oral cancer risk. A total of 81 cases of oral cancers were matched with 162 controls in this hospital-based study. Information on sociodemographic characteristics and details of risk habits (duration, frequency and type of tobacco consumption and betel quid chewing) were collected. Association between smoking and betel quid chewing with oral cancer were analysed using conditional logistic regression. Slightly more than half of the cases (55.6%) were smokers where 88.9% of them smoked kretek. After adjusting for confounders, smokers have two fold increased risk, while the risk for kretek consumers and those smoking for more than 10 years was increased to almost three-fold. Prevalence of betel quid chewing among cases and controls was low (7.4% and 1.9% respectively). Chewing of at least one quid per day, and quid combination of betel leaf, areca nut, lime and tobacco conferred a 5-6 fold increased risk. Smoking is positively associated with oral cancer risk. A similar direct association was also seen among betel quid chewers.

  15. Betel nut chewing and the risk of chronic kidney disease: evidence from a meta-analysis.

    Science.gov (United States)

    Wang, Meng; Yu, Si-Yi; Lv, Zheng-Tao; Yao, Ying

    2018-06-01

    To investigate and quantify the potential association between betel nut chewing and the risk of chronic kidney disease (CKD). We searched five online databases including PubMed, EMBASE, ISI Web of Science, Wanfang and CNKI to identify observational studies that published prior to May, 1, 2017. The primary outcome was the association between betel nut chewing and CKD expressed as odds ratio (OR) and the corresponding 95% confidence interval (95%CI) after adjustment for other covariates. Meta-analysis was performed using RevMan 5.3 software; the leave-one-out sensitivity analysis was used to confirm the stability of drawn conclusion. Five studies comprising a total of 10,562 CKD patients and 34,038 subjects without CKD that analyzed the relationship between betel nut chewing and CKD were included in our study; all the included studies were performed in Taiwan. After the adjustment for covariates, the combined adjusted ORs showed that betel nut used had 1.44 times higher risk to develop CKD compared with non-chewers (OR 1.44, 95%CI 1.08-1.92). Betel nut chewing could significantly increase the risk of CKD, indicating that betel nut chewing may exist as an independent risk factor for CKD. Further investigation should be warranted.

  16. Chewing lice from wild birds in northern Greece.

    Science.gov (United States)

    Diakou, Anastasia; Pedroso Couto Soares, José Bernardo; Alivizatos, Haralambos; Panagiotopoulou, Maria; Kazantzidis, Savas; Literák, Ivan; Sychra, Oldřich

    2017-10-01

    Greece represents an important area for wild birds due to its geographical position and habitat diversity. Although the bird species in Greece are well recorded, the information about the chewing lice that infest them is practically non-existent. Thus, the aim of the present study was to record the species of lice infesting wild birds in northern Greece and furthermore, to associate the infestation prevalence with factors such as the age, sex, migration and social behaviour of the host as well as the time of the year. In total 729 birds, (belonging to 9 orders, 32 families and 68 species) were examined in 7 localities of northern Greece, during 9 ringing sessions from June 2013 until October 2015. Eighty (11%) of the birds were found to be infested with lice. In 31 different bird species, 560 specimens of lice, belonging to 33 species were recorded. Mixed infestations were recorded in 11 cases where birds were infested with 2-3 different lice species. Four new host-parasite associations were recorded i.e. Menacanthus curuccae from Acrocephalus melanopogon, Menacanthus agilis from Cettia cetti, Myrsidea sp. from Acrocephalus schoenobaenus, and Philopretus citrinellae from Spinus spinus. Moreover, Menacanthus sinuatus was detected on Poecile lugubris, rendering this report the first record of louse infestation in this bird species. The statistical analysis of the data collected showed no association between parasitological parameters (prevalence, mean and median intensity and mean abundance) in two different periods of the year (breeding vs post-breeding season). However, there was a statistically significant difference in the prevalence of infestation between a) migrating and sedentary passerine birds (7.4% vs 13.2%), b) colonial and territorial birds (54.5% vs 9.6%), and c) female and male birds in breeding period (2.6% vs 15.6%). Copyright © 2017. Published by Elsevier B.V.

  17. Anatomy and adaptations of the chewing muscles in Daubentonia (Lemuriformes).

    Science.gov (United States)

    Perry, Jonathan M G; Macneill, Kristen E; Heckler, Amanda L; Rakotoarisoa, Gilbert; Hartstone-Rose, Adam

    2014-02-01

    The extractive foraging behavior in aye-ayes (Daubentonia madagascariensis) is unique among primates and likely has led to selection for a specialized jaw adductor musculature. Although this musculature has previously been examined in a subadult, until now, no one has reported the fascicle length, weight, and physiological cross-sectional area (PCSA) for these muscles in an adult aye-aye specimen. For the present study, we dissected an adult wild-born aye-aye from the Tsimbazaza Botanical and Zoological Park, Antananarivo, Madagascar. The aye-aye follows the general strepsirrhine pattern in its overall jaw adductor muscle anatomy, but has very large muscles and PCSA relative to body size. Fascicle length is also relatively great, but not nearly as much as in the juvenile aye-aye previously dissected. Perhaps chewing muscle fascicles begin relatively long, but shorten through use and growth as connective tissue sheets expand and allow for pinnation and increased PCSA. Alternately, it may be that aye-ayes develop fascicular adaptation to wide gapes early in ontogeny, only to increase PCSA through later development into adulthood. The functional demands related to their distinctive manner of extractive foraging are likely responsible for the great PCSA in the jaw adductor muscles of the adult aye-aye. It may be that great jaw adductor PCSA in the adult, as compared to the juvenile, is a means of increasing foraging efficiency in the absence of parental assistance. Anat Rec, 297:308-316, 2014. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc.

  18. Effects of chewing gum on cognitive function, mood and physiology in stressed and non-stressed volunteers.

    Science.gov (United States)

    Smith, Andrew

    2010-02-01

    Recent research suggests that chewing gum may improve aspects of cognitive function and mood. There is also evidence suggesting that chewing gum reduces stress. It is important, therefore, to examine these two areas and to determine whether contextual factors (chewing habit, type of gum, and personality) modify such effects. The aims of the present study were: (i) to determine whether chewing gum improved mood and mental performance; (ii) to determine whether chewing gum had benefits in stressed individuals; and (iii) to determine whether chewing habit, type of gum and level of anxiety modified the effects of gum. A cross-over study involving 133 volunteers was carried out. Each volunteer carried out a test session when they were chewing gum and without gum, with order of gum conditions counterbalanced across subjects. Baseline sessions were conducted prior to each test session. Approximately half of the volunteers were tested in 75 dBA noise (the stress condition) and the rest in quiet. Volunteers were stratified on chewing habit and anxiety level. Approximately, half of the volunteers were given mint gum and half fruit gum. The volunteers rated their mood at the start and end of each session and had their heart rate monitored over the session. Saliva samples were taken to allow cortisol levels (good indicator of alertness and stress) to be assayed. During the session, volunteers carried out tasks measuring a range of cognitive functions (aspects of memory, selective and sustained attention, psychomotor speed and accuracy). Chewing gum was associated with greater alertness and a more positive mood. Reaction times were quicker in the gum condition, and this effect became bigger as the task became more difficult. Chewing gum also improved selective and sustained attention. Heart rate and cortisol levels were higher when chewing which confirms the alerting effect of chewing gum. Overall, the results suggest that chewing gum produces a number of benefits that are

  19. Geometric continuum regularization of quantum field theory

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1989-01-01

    An overview of the continuum regularization program is given. The program is traced from its roots in stochastic quantization, with emphasis on the examples of regularized gauge theory, the regularized general nonlinear sigma model and regularized quantum gravity. In its coordinate-invariant form, the regularization is seen as entirely geometric: only the supermetric on field deformations is regularized, and the prescription provides universal nonperturbative invariant continuum regularization across all quantum field theory. 54 refs

  20. Prevalence of substance abuse among regular degree health science students in Sheba University College in Mekelle Town, Tigray - Ethiopia.

    Science.gov (United States)

    Hagos, Esietu Gebregazabher; Asfeha, Gebrekidan Gebregzabher; Berihu, Birhane Alem

    2016-01-01

    Substance abuse (SA) refers to the harmful or hazardous use of psychoactive substances, including alcohol and illicit drugs. The most common substances which are usually abused are alcohol and tobacco. Herein, we assessed the prevalence of SA among regular degree health science students of the Sheba University College (SUC). A cross-sectional survey was carried out among 1076 SUC students using self-administered structured questionnaire. The simple sampling technique was used to select students. Descriptive statistics, bivariate, and multivariate analysis were done. The overall prevalence of "ever used substance" for at least one was 45.5%. The most commonly used drugs in descending order were alcohol (25.1%), cigarette (11.4%), and khat (9.2%). Male participants, urban setting, peer pressure, personal pleasure, and academic dissatisfaction and pocket money were highly associated with SA. This study showed a lower magnitude (45.6% ever use and 21% still using) of SA among students' compared to other studies. Even if a considerable decrease in SA among study subjects, the creation of awareness and health education should be continued to fully combat the problem of abuse.

  1. Prevalence of substance abuse among regular degree health science students in Sheba University College in Mekelle Town, Tigray - Ethiopia

    Directory of Open Access Journals (Sweden)

    Esietu Gebregazabher Hagos

    2016-01-01

    Full Text Available Background: Substance abuse (SA refers to the harmful or hazardous use of psychoactive substances, including alcohol and illicit drugs. The most common substances which are usually abused are alcohol and tobacco. Herein, we assessed the prevalence of SA among regular degree health science students of the Sheba University College (SUC. Materials and Methods: A cross-sectional survey was carried out among 1076 SUC students using self-administered structured questionnaire. The simple sampling technique was used to select students. Descriptive statistics, bivariate, and multivariate analysis were done. Results: The overall prevalence of “ever used substance” for at least one was 45.5%. The most commonly used drugs in descending order were alcohol (25.1%, cigarette (11.4%, and khat (9.2%. Male participants, urban setting, peer pressure, personal pleasure, and academic dissatisfaction and pocket money were highly associated with SA. Conclusion: This study showed a lower magnitude (45.6% ever use and 21% still using of SA among students' compared to other studies. Even if a considerable decrease in SA among study subjects, the creation of awareness and health education should be continued to fully combat the problem of abuse.

  2. Effect of probiotic chewing tablets on early childhood caries--a randomized controlled trial

    DEFF Research Database (Denmark)

    Hedayati-Hajikand, Trifa; Lundberg, Ulrika; Eldh, Catarina

    2015-01-01

    BACKGROUND: To evaluate the effect of probiotic chewing tablets on early childhood caries development in preschool children living in a low socioeconomic multicultural area. METHODS: The investigation employed a randomized double-blind placebo-controlled design. The study group consisted of 138...... healthy 2-3-year-old children that were consecutively recruited after informed parental consent. After enrollment, they were randomized to a test or a placebo group. The parents of the test group were instructed to give their child one chewing tablet per day containing three strains of live probiotic...... childhood caries development could be reduced through administration of these probiotic chewing tablets as adjunct to daily use of fluoride toothpaste in preschool children. Further studies on a possible dose-response relationship seem justified TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01720771...

  3. In-vivo determination of chewing patterns using FBG and artificial neural networks

    Science.gov (United States)

    Pegorini, Vinicius; Zen Karam, Leandro; Rocha Pitta, Christiano S.; Ribeiro, Richardson; Simioni Assmann, Tangriani; Cardozo da Silva, Jean Carlos; Bertotti, Fábio L.; Kalinowski, Hypolito J.; Cardoso, Rafael

    2015-09-01

    This paper reports the process of pattern classification of the chewing process of ruminants. We propose a simplified signal processing scheme for optical fiber Bragg grating (FBG) sensors based on machine learning techniques. The FBG sensors measure the biomechanical forces during jaw movements and an artificial neural network is responsible for the classification of the associated chewing pattern. In this study, three patterns associated to dietary supplement, hay and ryegrass were considered. Additionally, two other important events for ingestive behavior studies were monitored, rumination and idle period. Experimental results show that the proposed approach for pattern classification has been capable of differentiating the materials involved in the chewing process with a small classification error.

  4. Analytical calculation of an invariant curve for Chew-Low equations

    International Nuclear Information System (INIS)

    Gerdt, V.P.

    1978-01-01

    The local structure of the one-parameter set of invariant curves for Chew-Low equations having the form of the convergent series is considered. Coefficients of this series βsub(i)(C) are polynomials in set parameter C. The transition to the general solution of Chew-Low equations is carried out by replacing the parameter C by arbitrary even, real, meromorphic function C(w) with the property C(w+1)=-C(w). The procedure for calculation of coefficients βsub(i)(C), which is based on the solution of nonlinear functional eqtions, following from Chew-Low equations, is developed. First twelve coefficients βsub(i)(C) are calculated analytically by computer, using program system SCHOONSCHIP

  5. Dose response of xylitol and sorbitol for epr retrospective dosimetry with applications to chewing gum

    International Nuclear Information System (INIS)

    Israelsson, A.; Gustafsson, H.; Lund, E.

    2013-01-01

    The purpose of this investigation was to study the radiation-induced electron paramagnetic resonance signal in sweeteners xylitol and sorbitol for use in retrospective dosimetry. For both sweeteners and chewing gum, the signal changed at an interval of 1-84 d after irradiation with minimal changes after 4-8 d. A dependence on storage conditions was noticed and the exposure of the samples to light and humidity was therefore minimised. Both the xylitol and sorbitol signals showed linearity with dose in the measured dose interval, 0-20 Gy. The dose-response measurements for the chewing gum resulted in a decision threshold of 0.38 Gy and a detection limit of 0.78 Gy. A blind test illustrated the possibility of using chewing gums as a retrospective dosemeter with an uncertainty in the dose determination of 0.17 Gy (1 SD). (authors)

  6. Mutanase-containing chewing gum: A new potential approach for prevention of dental caries

    Directory of Open Access Journals (Sweden)

    Jafar Kolahi

    2013-01-01

    Full Text Available Introduction: Study on the effect of topically applied mutanase on plaque formation and caries in rats showed strong inhibition of dental caries. Furthermore, it has been shown that the presence of mutanase in dental plaque may affect the synthesis and structure of sticky, extracellular glucans. The Hypothesis: Mutanase can be easily added to gum base. After chewing of mutanase-containing chewing gum, the enzyme will be released into the oral cavity. Mutanase will hydrolyze sticky, extracellular glucans, e.g., mutan inhibiting cariogenic bacteria to cohere/adhere and form plaque. Evaluation of the Hypothesis: The main challenge with this hypothesis is the source of mutanase. It can be obtained from Paenibacillus sp. MP-1 or Trichoderma harzianum F-340. Directly compressible medicated chewing gum bases can be used to avoid inactivation of mutanase during the manufacturing process.

  7. Effectiveness of a vegetable dental chew on periodontal disease parameters in toy breed dogs.

    Science.gov (United States)

    Clarke, D E; Kelman, M; Perkins, N

    2011-01-01

    Sixteen toy breed dogs completed a parallel, 70-day two-period, cross-over design clinical study to determine the effect of a vegetable dental chew on gingivitis, halitosis, plaque, and calculus accumulations. The dogs were randomly assigned into two groups. During one study period the dogs were fed a non-dental dry diet only and during the second study period were fed the same dry diet supplemented by the daily addition of a vegetable dental chew. Daily administration of the dental chew was shown to reduce halitosis, as well as, significantly reduce gingivitis, plaque and calculus accumulation and therefore may play a significant role in the improvement of canine oral health over the long-term.

  8. Metric regularity and subdifferential calculus

    International Nuclear Information System (INIS)

    Ioffe, A D

    2000-01-01

    The theory of metric regularity is an extension of two classical results: the Lyusternik tangent space theorem and the Graves surjection theorem. Developments in non-smooth analysis in the 1980s and 1990s paved the way for a number of far-reaching extensions of these results. It was also well understood that the phenomena behind the results are of metric origin, not connected with any linear structure. At the same time it became clear that some basic hypotheses of the subdifferential calculus are closely connected with the metric regularity of certain set-valued maps. The survey is devoted to the metric theory of metric regularity and its connection with subdifferential calculus in Banach spaces

  9. Manifold Regularized Correlation Object Tracking.

    Science.gov (United States)

    Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling

    2018-05-01

    In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped from both target and nontarget regions. Thus, the final classifier in our method is trained with positive, negative, and unlabeled base samples, which is a semisupervised learning framework. A block optimization strategy is further introduced to learn a manifold regularization-based correlation filter for efficient online tracking. Experiments on two public tracking data sets demonstrate the superior performance of our tracker compared with the state-of-the-art tracking approaches.

  10. Psychological stress-relieving effects of chewing - Relationship between masticatory function-related factors and stress-relieving effects.

    Science.gov (United States)

    Tasaka, Akinori; Kikuchi, Manaki; Nakanishi, Kousuke; Ueda, Takayuki; Yamashita, Shuichiro; Sakurai, Kaoru

    2018-01-01

    The objective of the present study was to investigate the relationship between masticatory function-related factors (masticatory performance, occlusal contact area, maximum bite force, number of chewing strokes, and muscle activity) and the stress-relieving effects of chewing. A total of 28 healthy male subjects were instructed to rest or chew for 10min after 30min of stress loading with arithmetic calculations. Their stress state was assessed by measuring salivary cortisol levels. Saliva was collected at three time points: before stress loading, immediately after stress loading, and 10min after stress loading. Compared to resting, chewing produced a significantly greater reduction in the rate of change in salivary cortisol levels 10min after stress loading. A negative correlation was observed between the rate of decrease in salivary cortisol levels and the number of chewing strokes. No significant correlation was observed between the rate of decrease in salivary cortisol levels and other measurement items. In healthy dentulous people, the number of chewing strokes has been shown to be a masticatory function-related factor that affects stress relief from chewing, suggesting the possibility that more appropriate chewing would produce a greater effect psychological stress relief. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  11. On the Chew-Low plot as a limiting case of the distorted wave theory of break-up reactions

    International Nuclear Information System (INIS)

    Baur, G.

    1976-01-01

    A recently developed formulation of break-up reactions in the frame of the DW approximation is compared to a theory of Chew and Low given in 1958. By suitably rewriting the DWBA matrix element, one can pick out a term, dominant for certain kinematical conditions, which is identical to the expression given by Chew and Low. (orig.) [de

  12. Potential benefits of chewing gum for the delivery of oral therapeutics and its possible role in oral healthcare

    NARCIS (Netherlands)

    Wessel, Stefan W.; van der Mei, Henny C.; Maitra, Amarnath; Dodds, Michael W. J.; Busscher, Henk J.

    2016-01-01

    Introduction: Over the years, chewing gum has developed from a candy towards an oral health-promoting nutraceutical. This review summarizes evidence for the oral health benefits of chewing gum, emphasizing identification of active ingredients in gum that facilitate prevention and removal of oral

  13. Betel quid, chewing habits and difficult intubation: A case report and critical appraisal of evidence for practice.

    Science.gov (United States)

    Narendra, P L; Hegde, Harihar V; Vijaykumar, T K; Nallamilli, Samson

    2015-01-01

    Betel quid is used by 10-20% of world of population. Oral submucus fibrosis (OSF) is a chronic premalignant disease common in South Asian countries where betel quid is chewed. It is characterized by juxtaepithelial fibrosis of oral cavity and limited mouth opening, which can cause difficult intubation. A recent study in Taiwan has revealed long-term betel nut chewing is not predictor of difficult intubation. We describe two cases of OSF and critically analyze this study and its implications for clinical practice. OSF is now seen in Saudi Arabia and western countries with use of commercial betel quid substitutes. Although betel quid without tobacco is used in Taiwan, available evidence suggests rapid and early development of OSF where commercial chewing products like Pan Masala are used in India. Effects of betel quid may vary depending on the composition of quid and chewing habits. Studies where personal habits are involved must be analyzed carefully for external validity. Even though, Taiwan study is controlled, its validity outside Taiwan is highly questionable. Since OSF can cause unanticipated difficult intubation, thus during preanesthetic assessment, history of betel quid chewing, more importantly use of commercial chewing products is more likely to give clues to severity of OSF and possible difficult intubation. Further controlled trails in populations where commercial chewing products are used is necessary to detect association of chewing habits and difficult intubation.

  14. Chewing bread: impact on alpha-amylase secretion and oral digestion.

    Science.gov (United States)

    Joubert, Marianne; Septier, Chantal; Brignot, Hélène; Salles, Christian; Panouillé, Maud; Feron, Gilles; Tournier, Carole

    2017-02-22

    During chewing, saliva helps in preparing the food bolus by agglomerating the formed particles, and it initiates enzymatic food breakdown. However, limited information is actually available on the adaptation of saliva composition during the oral processing of complex foods, especially for foods that are sensitive to salivary enzymes. We addressed this question in the context of starch-based products and salivary alpha-amylase. The objectives were two-fold: (1) to determine if salivary alpha-amylase secretion can be modulated by the bread type and (2) to evaluate the contribution of the oral phase in bread enzymatic breakdown. Mouthfuls of three different wheat breads (industrial, artisan and whole-meal breads) were chewed by twelve subjects. Saliva samples were collected at rest and at different times corresponding to 33, 66 and 100% of the individual's chewing sequence. Alpha-amylase activity and total protein content were determined for all saliva samples that were collected. Additionally, the salivary maltose concentration was measured as a marker of bread enzymatic digestion. Boluses were collected at the swallowing time to evaluate the saliva uptake. Chewing industrial bread induced higher saliva uptake than the other breads despite a similar chewing duration. The evolution of salivary amylase activity tended to depend on the type of bread and was highly influenced by a large degree of inter- and intra-subject variability. The protein and maltose concentration steadily increased during chewing as a result of bread breakdown. The salivary protein concentration was mainly affected by the release of the water-soluble proteins of the bread. The salivary maltose concentration was found to be significantly lower for the whole-meal bread. When considering the weight of the mouthful, enzymatic breakdown was found to be most efficient for the breads ranking from industrial > artisan > whole-meal.

  15. Dental status, oral prosthesis and chewing ability in an adult and elderly population in southern Brazil.

    Science.gov (United States)

    Baumgarten, Alexandre; Schmidt, Jeanne Gabriele; Rech, Rafaela Soares; Hilgert, Juliana Balbinot; Goulart, Bárbara Niegia Garcia de

    2017-11-01

    The objective of this study was to explore the factors associated with inadequate chewing in an adult and elderly population of a city in the southern region of Brazil. This was a cross-sectional study based on a population home-based inquiry (DCH-POP) in southern Brazil. Individuals were interviewed by trained interviewers to create a standardized procedure. In a pilot study, the Questionnaire of Human Communication Disorders (DCH-POP) was created and validated to identify self-reported speech and language, swallowing and hearing disorders. The outcome was dichotomized into either having adequate chewing or not, as assessed by a series of questions about chewing ability. Analyses of absolute and relative frequencies were measured according to the studied variables. A Poisson regression was applied at a significance level of 5%. A total of 1,246 people were interviewed. Inadequate chewing was found in 52 (5.6%) individuals, with a higher prevalence in the elderly (11.8%) than in adults (5.2%). In the final model, the following factors were associated with inadequate chewing: being 61 years of age or older (prevalence ratio or PR=9.03; 95% CI: 1.20-67.91), loss of teeth and use of unadjusted prosthesis (PR=3.50; 95% CI: 1.54-7.95), preference for foods of soft consistency (PR=9.34; 95% CI:4.66-8.70) and difficulty in nasal breathing (PR=2.82; 95% CI: 1.31-6.06). Age, oral health status through dental prosthesis, preference for foods of soft consistency and difficulty breathing through the nose were factors associated with chewing inability in adults and the elderly.

  16. Development of Chewing in Children From 12 to 48 Months: Longitudinal Study of EMG Patterns

    Science.gov (United States)

    GREEN, JORDAN R.; MOORE, CHRISTOPHER A.; RUARK, JACKI L.; RODDA, PAULA R.; MORVÉE, WENDY T.; VanWITZENBURG, MARCUS J.

    2014-01-01

    Developmental changes in the coordinative organization of masticatory muscles were examined longitudinally in four children over 49 experimental sessions spanning the age range of 12–48 mo. Electromyographic (EMG) records were obtained for right and left masseter muscles, right and left temporalis muscles, and the anterior belly of the digastric. Two independent analytic processes were employed, one that relied on identification of onset and offset of muscle activation and a second that used pairwise cross-correlational techniques. The results of these two analyses, which were found to be consistent with each other, demonstrated that the basic chewing pattern of reciprocally activated antagonistic muscle groups is established by 12 mo of age. Nevertheless, chewing efficiency appears to be improved through a variety of changes in the chewing pattern throughout early development. Coupling of activity among the jaw elevator muscles was shown to strengthen with maturation, and the synchrony of onset and offset of these muscles also increased. Coactivation of antagonistic muscles decreased significantly with development. This decrease in antagonistic coactivation and increase in synchrony among jaw elevators, and a parallel decrease in EMG burst duration, were taken as evidence of increased chewing efficiency. No significant differences in the frequency of chewing were found across the ages studied. Additional considerations include the appropriateness of this coordinative infrastructure for other developing oromotor skills, such as speech production. It is suggested that the relatively fixed coordinative framework for chewing exhibited by these children would not be suitable for adaptation to speech movements, which have been shown to rely on a much more variable and adjustable coordinative organization. PMID:9163386

  17. Non-invasive monitoring of chewing and swallowing for objective quantification of ingestive behavior

    International Nuclear Information System (INIS)

    Sazonov, Edward; Schuckers, Stephanie; Lopez-Meyer, Paulo; Makeyev, Oleksandr; Sazonova, Nadezhda; Melanson, Edward L; Neuman, Michael

    2008-01-01

    A methodology of studying of ingestive behavior by non-invasive monitoring of swallowing (deglutition) and chewing (mastication) has been developed. The target application for the developed methodology is to study the behavioral patterns of food consumption and producing volumetric and weight estimates of energy intake. Monitoring is non-invasive based on detecting swallowing by a sound sensor located over laryngopharynx or by a bone-conduction microphone and detecting chewing through a below-the-ear strain sensor. Proposed sensors may be implemented in a wearable monitoring device, thus enabling monitoring of ingestive behavior in free-living individuals. In this paper, the goals in the development of this methodology are two-fold. First, a system comprising sensors, related hardware and software for multi-modal data capture is designed for data collection in a controlled environment. Second, a protocol is developed for manual scoring of chewing and swallowing for use as a gold standard. The multi-modal data capture was tested by measuring chewing and swallowing in 21 volunteers during periods of food intake and quiet sitting (no food intake). Video footage and sensor signals were manually scored by trained raters. Inter-rater reliability study for three raters conducted on the sample set of five subjects resulted in high average intra-class correlation coefficients of 0.996 for bites, 0.988 for chews and 0.98 for swallows. The collected sensor signals and the resulting manual scores will be used in future research as a gold standard for further assessment of sensor design, development of automatic pattern recognition routines and study of the relationship between swallowing/chewing and ingestive behavior

  18. Nonlinear association between betel quid chewing and oral cancer: Implications for prevention.

    Science.gov (United States)

    Madathil, Sreenath Arekunnath; Rousseau, Marie-Claude; Wynant, Willy; Schlecht, Nicolas F; Netuveli, Gopalakrishnan; Franco, Eduardo L; Nicolau, Belinda

    2016-09-01

    Betel quid chewing is a major oral cancer risk factor and the human papillomaviruses (HPV) may play an aetiological role in these cancers. However, little is known about the shape of the dose-response relationship between the betel quid chewing habit and oral cancer risk in populations without HPV. We estimate the shape of this dose-response relationship, and discuss implications for prevention. Cases with oral squamous cell carcinoma (350) and non-cancer controls (371) were recruited from two major teaching hospitals in South India. Information on socio-demographic and behavioral factors was collected using a questionnaire and the life grid technique. The effect of daily amount of use and duration of the habit were estimated jointly as risk associated with cumulative exposure (chew-years). The shape of the dose-response curve was estimated using restricted cubic spline transformation of chew-years in a conditional logistic regression model. Risk estimates for low dose combinations of daily amount and duration of the habit were computed from flexible regression. Most (72%) oral cancer cases were betel quid chewers in contrast to only 18% of controls. A nonlinear dose-response relationship was observed; the risk increased steeply at low doses and plateaued at high exposures to betel quid (>425 chew-years). A threefold increase in risk (OR=3.92, 95%CI: 1.87-8.21) was observed for the lowest dose; equivalent to the use of one quid per day for one year. Our findings may be used to counsel people to refrain from even low betel quid chewing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Non-invasive monitoring of chewing and swallowing for objective quantification of ingestive behavior.

    Science.gov (United States)

    Sazonov, Edward; Schuckers, Stephanie; Lopez-Meyer, Paulo; Makeyev, Oleksandr; Sazonova, Nadezhda; Melanson, Edward L; Neuman, Michael

    2008-05-01

    A methodology of studying of ingestive behavior by non-invasive monitoring of swallowing (deglutition) and chewing (mastication) has been developed. The target application for the developed methodology is to study the behavioral patterns of food consumption and producing volumetric and weight estimates of energy intake. Monitoring is non-invasive based on detecting swallowing by a sound sensor located over laryngopharynx or by a bone-conduction microphone and detecting chewing through a below-the-ear strain sensor. Proposed sensors may be implemented in a wearable monitoring device, thus enabling monitoring of ingestive behavior in free-living individuals. In this paper, the goals in the development of this methodology are two-fold. First, a system comprising sensors, related hardware and software for multi-modal data capture is designed for data collection in a controlled environment. Second, a protocol is developed for manual scoring of chewing and swallowing for use as a gold standard. The multi-modal data capture was tested by measuring chewing and swallowing in 21 volunteers during periods of food intake and quiet sitting (no food intake). Video footage and sensor signals were manually scored by trained raters. Inter-rater reliability study for three raters conducted on the sample set of five subjects resulted in high average intra-class correlation coefficients of 0.996 for bites, 0.988 for chews and 0.98 for swallows. The collected sensor signals and the resulting manual scores will be used in future research as a gold standard for further assessment of sensor design, development of automatic pattern recognition routines and study of the relationship between swallowing/chewing and ingestive behavior.

  20. Differences in chewing sounds of dry-crisp snacks by multivariate data analysis

    Science.gov (United States)

    De Belie, N.; Sivertsvik, M.; De Baerdemaeker, J.

    2003-09-01

    Chewing sounds of different types of dry-crisp snacks (two types of potato chips, prawn crackers, cornflakes and low calorie snacks from extruded starch) were analysed to assess differences in sound emission patterns. The emitted sounds were recorded by a microphone placed over the ear canal. The first bite and the first subsequent chew were selected from the time signal and a fast Fourier transformation provided the power spectra. Different multivariate analysis techniques were used for classification of the snack groups. This included principal component analysis (PCA) and unfold partial least-squares (PLS) algorithms, as well as multi-way techniques such as three-way PLS, three-way PCA (Tucker3), and parallel factor analysis (PARAFAC) on the first bite and subsequent chew. The models were evaluated by calculating the classification errors and the root mean square error of prediction (RMSEP) for independent validation sets. It appeared that the logarithm of the power spectra obtained from the chewing sounds could be used successfully to distinguish the different snack groups. When different chewers were used, recalibration of the models was necessary. Multi-way models distinguished better between chewing sounds of different snack groups than PCA on bite or chew separately and than unfold PLS. From all three-way models applied, N-PLS with three components showed the best classification capabilities, resulting in classification errors of 14-18%. The major amount of incorrect classifications was due to one type of potato chips that had a very irregular shape, resulting in a wide variation of the emitted sounds.

  1. Dimensional regularization in configuration space

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1995-09-01

    Dimensional regularization is introduced in configuration space by Fourier transforming in D-dimensions the perturbative momentum space Green functions. For this transformation, Bochner theorem is used, no extra parameters, such as those of Feynman or Bogoliubov-Shirkov are needed for convolutions. The regularized causal functions in x-space have ν-dependent moderated singularities at the origin. They can be multiplied together and Fourier transformed (Bochner) without divergence problems. The usual ultraviolet divergences appear as poles of the resultant functions of ν. Several example are discussed. (author). 9 refs

  2. Regular algebra and finite machines

    CERN Document Server

    Conway, John Horton

    2012-01-01

    World-famous mathematician John H. Conway based this classic text on a 1966 course he taught at Cambridge University. Geared toward graduate students of mathematics, it will also prove a valuable guide to researchers and professional mathematicians.His topics cover Moore's theory of experiments, Kleene's theory of regular events and expressions, Kleene algebras, the differential calculus of events, factors and the factor matrix, and the theory of operators. Additional subjects include event classes and operator classes, some regulator algebras, context-free languages, communicative regular alg

  3. Matrix regularization of 4-manifolds

    OpenAIRE

    Trzetrzelewski, M.

    2012-01-01

    We consider products of two 2-manifolds such as S^2 x S^2, embedded in Euclidean space and show that the corresponding 4-volume preserving diffeomorphism algebra can be approximated by a tensor product SU(N)xSU(N) i.e. functions on a manifold are approximated by the Kronecker product of two SU(N) matrices. A regularization of the 4-sphere is also performed by constructing N^2 x N^2 matrix representations of the 4-algebra (and as a byproduct of the 3-algebra which makes the regularization of S...

  4. Laportea aestuans (L. Chew (Urticaceae, a Newly Recorded Plant in Taiwan

    Directory of Open Access Journals (Sweden)

    Tsai-Wen Hsu

    2003-03-01

    Full Text Available Laportea, comprising ca. 22 species, is a genus of the Urticaceae. Two species were previously recorded in the 2nd edition of Flora of Taiwan. In the course of our botanical inventory, one additional weedy species, namely Laportea aestuans (L. Chew, was found in the central Taiwan. Morphologically, L. aestuans is closely related to L. interrupta (L. Chew by sharing ovate leaves. Branched racemes of L. aestuans are distinct from the unbranched racemes of L. interrupta. Laportea aestuans is a species mainly distributed at low elevations in central Taiwan.

  5. Chew the Pain Away: Oral Habits to Cope with Pain and Stress and to Stimulate Cognition

    Directory of Open Access Journals (Sweden)

    Roxane Anthea Francesca Weijenberg

    2015-01-01

    Full Text Available The acute effects of chewing gum on cognitive performance, stress, and pain have been intensively studied in the last decade. The results have been contradicting, and replication studies proved challenging. Here, we review some of the recent findings of this topic and explore possible explanations for these discrepancies by incorporating knowledge derived from studies into oral habits and bruxism. Both stress and cerebral functional specialization (i.e., the involvement of specific brain structures in distinctive cognitive processes are hypothesized to play a major role in the underlying physiological mechanisms of the diverse effects of chewing gum on cognition, stress, and pain.

  6. How well can the Chew-Low theory reproduce pion-nucleon scattering

    International Nuclear Information System (INIS)

    Bajaj, K.K.; Nogami, Y.

    1975-01-01

    When the Chew-Low theory for the πN interaction is used as a basis for studying the π-nucleus interaction, it is required to fit the free πN scattering data well. In this respect many calculations so far done are unsatisfactory. We show that an excellent fit is obtained within the existing Chew-Low framework if the inelasticity together with recoil and the crossing term are taken into account, and we comment on a recent work by Dover et al

  7. Chewing-induced hypertension in afferent baroreflex failure: a sympathetic response?

    Science.gov (United States)

    Fuente Mora, Cristina; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto; Kaufmann, Horacio

    2015-11-01

    What is the central question of this study? Our goal was to understand the autonomic responses to eating in patients with congenital afferent baroreflex failure, by documenting changes in blood pressure and heart rate with chewing, swallowing and stomach distension. What is the main finding and its importance? Patients born with lesions in the afferent baroreceptor pathways have an exaggerated pressor response to food intake. This appears to be a sympathetically mediated response, triggered by chewing, that occurs independently of swallowing or distension of the stomach. The chewing-induced pressor response may be useful as a counter-manoeuvre to prevent orthostatic hypotension in these patients. Familial dysautonomia (FD) is a rare genetic disease with extremely labile blood pressure resulting from baroreflex deafferentation. Patients have marked surges in sympathetic activity, frequently surrounding meals. We conducted an observational study to document the autonomic responses to eating in patients with FD and to determine whether sympathetic activation was caused by chewing, swallowing or stomach distension. Blood pressure and R-R intervals were measured continuously while chewing gum (n = 15), eating (n = 20) and distending the stomach by percutaneous endoscopic gastrostomy tube feeding (n = 9). Responses were compared with those of normal control subjects (n = 10) and of patients with efferent autonomic failure (n = 10) who have chronically impaired sympathetic outflow. In patients with FD, eating was associated with a marked but transient pressor response (P Chewing gum evoked a similar increase in blood pressure that was higher in patients with FD than in control subjects (P = 0.0001), but was absent in patients with autonomic failure. In patients with FD, distending the stomach by percutaneous endoscopic gastrostomy tube feeding failed to elicit a pressor response. The results provide indirect evidence that chewing triggers sympathetic

  8. Chewing Lice of Swan Geese (Anser cygnoides): New Host-Parasite Associations

    DEFF Research Database (Denmark)

    Choi, Chang-Yong; Takekawa, John Y.; Prosser, Diann J.

    2016-01-01

    Chewing lice (Phthiraptera) that parasitize the globally threatened swan goose Anser cygnoides have been long recognized since the early 19th century, but those records were probably biased towards sampling of captive or domestic geese due to the small population size and limited distribution...... of its wild hosts. To better understand the lice species parasitizing swan geese that are endemic to East Asia, we collected chewing lice from 14 wild geese caught at 3 lakes in northeastern Mongolia. The lice were morphologically identified as 16 Trinoton anserinum (Fabricius, 1805), 11 Ornithobius...

  9. Relationship between energy intake and chewing index of diets fed to pregnant ewes

    DEFF Research Database (Denmark)

    Nielsen, Mette Vestergaard; Nadeau, E.; Markussen, Bo

    2015-01-01

    The objective was to determine whether a linear relationship exists between the metabolizable energy (ME) intake of pregnant ewes and a dietary chewing index (CI). The relationship was studied using five feeding trials with intake data from 108 pregnant ewes, 4 to 1 weeks before lambing, giving...... includes random variation of week within experiment on the intercept and linear fixed effect of week before lambing on parameter k. The maximum daily chewing time, CTmax, for the pregnant ewes was predicted to be 1/(4 × k). The MEI declined linearly with increasing dietary CI (P

  10. Multielement analysis of Nigerian chewing sticks by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Asubiojo, O.I.; Guinn, V.P.

    1982-01-01

    In Nigeria, various parts of various species of native plants have long been used for dental hygiene, with reportedly considerable effectiveness. These materials are known as 'chewing sticks'. This study was an effort to ascertain whether any unusual trace element concentrations might be present in Nigerian chewing sticks. Results are presented for 17 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Mn, Fe, Co, Zn, Br, Cs, La, Sm, Au) detected and measured in 12 species of such plants, via instrumental thermal-neutron activation analysis. (author)

  11. Multielement analysis of Nigerian chewing sticks by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Asubiojo, O.I.; Guinn, V.P. (California Univ., Irvine (USA). Dept. of Chemistry); Okunuga, A. (California Polytechnic Univ., Pomona, CA (USA))

    1982-01-01

    In Nigeria, various parts of various species of native plants have long been used for dental hygiene, with reportedly considerable effectiveness. These materials are known as 'chewing sticks'. This study was an effort to ascertain whether any unusual trace element concentrations might be present in Nigerian chewing sticks. Results are presented for 17 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Mn, Fe, Co, Zn, Br, Cs, La, Sm, Au) detected and measured in 12 species of such plants, via instrumental thermal-neutron activation analysis.

  12. Computer local construction of a general solution for the Chew-Low equations

    International Nuclear Information System (INIS)

    Gerdt, V.P.

    1980-01-01

    General solution of the dynamic form of the Chew-Low equations in the vicinity of the restpoint is considered. A method for calculating coefficients of series being members of such solution is suggested. The results of calculations, coefficients of power series and expansions carried out by means of the SCHOONSCHIP and SYMBAL systems are given. It is noted that the suggested procedure of the Chew-Low equation solutions basing on using an electronic computer as an instrument for analytical calculations permits to obtain detail information on the local structure of general solution

  13. The role of betel-quid chewing in smoking cessation among workers in Taiwan.

    Science.gov (United States)

    Chen, Fu-Li; Chen, Peter Y; Tung, Tao-Hsin; Huang, Yu-Ching; Tsai, Min-Chien

    2014-07-28

    Current smokers exhibit a higher rate of betel-quid chewing than non-smokers. However, little is known regarding the extent to which betel-quid chewing may affect attempts to quit smoking and smoking cessation. The aim of the present study is to examine the association between betel-quid chewing and patterns of quitting smoking. Specifically, we explore whether betel-quid chewing is associated with (1) current smokers who have never attempted to quit versus those who have attempted to quit and have failed, those who are in the process of quitting, and successful cessation smokers, and (2) current smokers who have attempted to quit and have failed versus those who have successfully quit smoking. A telephone survey of 7,215 workers was conducted and obtained an 88.6% response rate. In the survey, the respondents' smoking and betel-quid chewing statuses were recorded and a list of covariates was assessed. After controlling for the effect of the covariates, betel-quid chewing was found to be more highly associated with current smokers who have never attempted to quit, compared to current smokers who are in the process of quitting (OR = 12.72; 95% CI = 1.05-154.26), successful cessation smokers (OR = 3.62; 95% CI = 2.32-5.65), and smokers who have attempted to quit and have failed (OR = 1.37; 95% CI = 1.06-1.77), respectively. In addition, betel-quid chewing is more highly associated with a failure to quit smoking than with successfully quitting smoking (OR = 3.46; 95% CI = 2.17-5.51). The findings support four plausible reasons why betel-quid chewing may dissuade smokers from quitting. These reasons highlight additional avenues for potentially reducing the smoking population in workplaces, such as considering work contexts and social norms, and product sales in smoking-cessation campaigns.

  14. QUALITATIVE EVALUATION OF SUBGINGIVAL MICROFLORA AFTER THE CHEWING OF BETEL LEAF

    OpenAIRE

    K Vani; Jose Maji; Rao Srinivasa

    2011-01-01

    Betel a branching vine, scientifically called as Piper betel, is used in a number of traditional remedies and known to have immune boosting as well as antibacterial properties. This study was conducted to assess the qualitative changes in the sub-gingival micro flora, after the chewing of betel leaves, in order to evaluate the antimicrobial effect of this medicinal plant on oral pathogens.Forty volunteers were made to chew betel leaves daily for 5-10 minutes for a period of two weeks and the ...

  15. Regularization of Nonmonotone Variational Inequalities

    International Nuclear Information System (INIS)

    Konnov, Igor V.; Ali, M.S.S.; Mazurkevich, E.O.

    2006-01-01

    In this paper we extend the Tikhonov-Browder regularization scheme from monotone to rather a general class of nonmonotone multivalued variational inequalities. We show that their convergence conditions hold for some classes of perfectly and nonperfectly competitive economic equilibrium problems

  16. Lattice regularized chiral perturbation theory

    International Nuclear Information System (INIS)

    Borasoy, Bugra; Lewis, Randy; Ouimet, Pierre-Philippe A.

    2004-01-01

    Chiral perturbation theory can be defined and regularized on a spacetime lattice. A few motivations are discussed here, and an explicit lattice Lagrangian is reviewed. A particular aspect of the connection between lattice chiral perturbation theory and lattice QCD is explored through a study of the Wess-Zumino-Witten term

  17. 76 FR 3629 - Regular Meeting

    Science.gov (United States)

    2011-01-20

    ... Meeting SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). Date and Time: The meeting of the Board will be held at the offices of the Farm... meeting of the Board will be open to the [[Page 3630

  18. Forcing absoluteness and regularity properties

    NARCIS (Netherlands)

    Ikegami, D.

    2010-01-01

    For a large natural class of forcing notions, we prove general equivalence theorems between forcing absoluteness statements, regularity properties, and transcendence properties over L and the core model K. We use our results to answer open questions from set theory of the reals.

  19. Globals of Completely Regular Monoids

    Institute of Scientific and Technical Information of China (English)

    Wu Qian-qian; Gan Ai-ping; Du Xian-kun

    2015-01-01

    An element of a semigroup S is called irreducible if it cannot be expressed as a product of two elements in S both distinct from itself. In this paper we show that the class C of all completely regular monoids with irreducible identity elements satisfies the strong isomorphism property and so it is globally determined.

  20. Fluid queues and regular variation

    NARCIS (Netherlands)

    Boxma, O.J.

    1996-01-01

    This paper considers a fluid queueing system, fed by N independent sources that alternate between silence and activity periods. We assume that the distribution of the activity periods of one or more sources is a regularly varying function of index ¿. We show that its fat tail gives rise to an even

  1. Fluid queues and regular variation

    NARCIS (Netherlands)

    O.J. Boxma (Onno)

    1996-01-01

    textabstractThis paper considers a fluid queueing system, fed by $N$ independent sources that alternate between silence and activity periods. We assume that the distribution of the activity periods of one or more sources is a regularly varying function of index $zeta$. We show that its fat tail

  2. Empirical laws, regularity and necessity

    NARCIS (Netherlands)

    Koningsveld, H.

    1973-01-01

    In this book I have tried to develop an analysis of the concept of an empirical law, an analysis that differs in many ways from the alternative analyse's found in contemporary literature dealing with the subject.

    1 am referring especially to two well-known views, viz. the regularity and

  3. Interval matrices: Regularity generates singularity

    Czech Academy of Sciences Publication Activity Database

    Rohn, Jiří; Shary, S.P.

    2018-01-01

    Roč. 540, 1 March (2018), s. 149-159 ISSN 0024-3795 Institutional support: RVO:67985807 Keywords : interval matrix * regularity * singularity * P-matrix * absolute value equation * diagonally singilarizable matrix Subject RIV: BA - General Mathematics Impact factor: 0.973, year: 2016

  4. Regularization in Matrix Relevance Learning

    NARCIS (Netherlands)

    Schneider, Petra; Bunte, Kerstin; Stiekema, Han; Hammer, Barbara; Villmann, Thomas; Biehl, Michael

    A In this paper, we present a regularization technique to extend recently proposed matrix learning schemes in learning vector quantization (LVQ). These learning algorithms extend the concept of adaptive distance measures in LVQ to the use of relevance matrices. In general, metric learning can

  5. Regular and conformal regular cores for static and rotating solutions

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Aïnou, Mustapha

    2014-03-07

    Using a new metric for generating rotating solutions, we derive in a general fashion the solution of an imperfect fluid and that of its conformal homolog. We discuss the conditions that the stress–energy tensors and invariant scalars be regular. On classical physical grounds, it is stressed that conformal fluids used as cores for static or rotating solutions are exempt from any malicious behavior in that they are finite and defined everywhere.

  6. Regular and conformal regular cores for static and rotating solutions

    International Nuclear Information System (INIS)

    Azreg-Aïnou, Mustapha

    2014-01-01

    Using a new metric for generating rotating solutions, we derive in a general fashion the solution of an imperfect fluid and that of its conformal homolog. We discuss the conditions that the stress–energy tensors and invariant scalars be regular. On classical physical grounds, it is stressed that conformal fluids used as cores for static or rotating solutions are exempt from any malicious behavior in that they are finite and defined everywhere.

  7. Bridging the gap between chewing and sucking in the hemipteroid insects: new insights from Cretaceous amber.

    Science.gov (United States)

    Yoshizawa, Kazunori; Lienhard, Charles

    2016-02-11

    The diversity of feeding apparatuses in insects far exceeds that observed in any other animal group. Consequently, tracking mouthpart innovation in insects is one of the keys toward understanding their diversification. In hemipteroid insects (clade Paraneoptera or Acercaria: lice, thrips, aphids, cicadas, bugs, etc.), the transition from chewing to piercing-and-sucking mouthparts is widely regarded as the turning point that enabled hyperdiversification of the Hemiptera, the fifth largest insect order. However, the transitional process from chewing to piercing-and-sucking in the Paraneoptera was hitherto completely unknown. In this paper, we report a well preserved mid Cretaceous amber fossil of the paraneopteran insect family Archipsyllidae and describe it as Mydiognathus eviohlhoffae gen. et sp. n. This species has elongate mandibles and styliform laciniae similar to Hemiptera but retains functional chewing mouthparts. A number of morphological characters place the Archipsyllidae as the sister group of the thrips plus hemipterans, which strongly suggests that the mouthparts of M. eviohlhoffae represent a transitional condition from primitive chewing to derived piercing-and-sucking mouthparts. The clade composed of Archipsyllidae, thrips, and hemipterans is here named Pancondylognatha, a new supra-ordinal taxon. Based on newly obtained information, we also assess the monophyly of the Paraneoptera, which was called into question by recent phylogenomic analyses. A phylogenetic analysis that includes Mydiognathus strongly supports the monophyly of the Paraneoptera.

  8. Continuous analysis of parotid saliva during resting and short-duration simulated chewing

    NARCIS (Netherlands)

    Neyraud, E.; Bult, J.H.F.; Dransfield, E.

    2009-01-01

    Objective: Parotid saliva flow is increased by mastication and its composition is also modified. The aim of this work was to clarify the relationships between flow rate, pH and protein concentration, during resting and short-duration simulated chewing, using continuous and fractional saliva

  9. Always chew your food: freshwater stingrays use mastication to process tough insect prey.

    Science.gov (United States)

    Kolmann, Matthew A; Welch, Kenneth C; Summers, Adam P; Lovejoy, Nathan R

    2016-09-14

    Chewing, characterized by shearing jaw motions and high-crowned molar teeth, is considered an evolutionary innovation that spurred dietary diversification and evolutionary radiation of mammals. Complex prey-processing behaviours have been thought to be lacking in fishes and other vertebrates, despite the fact that many of these animals feed on tough prey, like insects or even grasses. We investigated prey capture and processing in the insect-feeding freshwater stingray Potamotrygon motoro using high-speed videography. We find that Potamotrygon motoro uses asymmetrical motion of the jaws, effectively chewing, to dismantle insect prey. However, CT scanning suggests that this species has simple teeth. These findings suggest that in contrast to mammalian chewing, asymmetrical jaw action is sufficient for mastication in other vertebrates. We also determined that prey capture in these rays occurs through rapid uplift of the pectoral fins, sucking prey beneath the ray's body, thereby dissociating the jaws from a prey capture role. We suggest that the decoupling of prey capture and processing facilitated the evolution of a highly kinetic feeding apparatus in batoid fishes, giving these animals an ability to consume a wide variety of prey, including molluscs, fishes, aquatic insect larvae and crustaceans. We propose Potamotrygon as a model system for understanding evolutionary convergence of prey processing and chewing in vertebrates. © 2016 The Author(s).

  10. Two-colour chewing gum mixing ability: digitalisation and spatial heterogeneity analysis

    NARCIS (Netherlands)

    Weijenberg, R.A.F.; Scherder, E.J.A.; Visscher, C.M.; Gorissen, T.; Yoshida, E.; Lobbezoo, F.

    2013-01-01

    Many techniques are available to assess masticatory performance, but not all are appropriate for every population. A proxy suitable for elderly persons suffering from dementia was lacking, and a two-colour chewing gum mixing ability test was investigated for this purpose. A fully automated digital

  11. Radiative pion-proton scattering in the static Chew-Low model

    International Nuclear Information System (INIS)

    Ho-Kim, Q.; Lavine, J.P.

    1976-01-01

    The results of a non-relativistic calculation of π +- -proton bremsstrahlung cross-sections at the pion laboratory kinetic energy of 298 MeV for backward photon angles are presented. The πp interaction is described by the static Chew-Low model. (Auth.)

  12. Real and imaginary parts of hadronic amplitudes, diffractive contributions and the Chew-Rosenzweig pomeron

    International Nuclear Information System (INIS)

    Chiu, C.B.; Tow, D.M.

    1978-01-01

    It is shown that when the f' and the diffractive elastic (and quasi-elastic) contributions are included within the Chew-Rosenzweig type solution for the pomeron, one can explain reasonably well the π and 2K - π total cross sections as well as the ratios of the real over imaginary parts of the forward π and K amplitudes. (Auth.)

  13. Radiative pion-proton scattering in the static Chew--Low model

    International Nuclear Information System (INIS)

    Ho-Kim, Q.; Lavine, J.P.

    1975-01-01

    The results of a nonrelativistic calculation of π/sup +-/-proton bremsstrahlung cross sections at the pion laboratory kinetic energy of 298 MeV for backward photon angles is presented. The πp interaction is described by the static Chew-Low model

  14. The Effects of Chewing Cinnamon Flavored Gum on Mood, Feeling and Spelling Acquisition

    Science.gov (United States)

    Wilson, Andrew; Kim, Wonsun; Raudenbush, Bryan

    2016-01-01

    The purpose of the study is to investigate if the effects of chewing cinnamon flavored gum can increase mood, feeling and spelling acquisition. 5th grade students (n = 22) at Ilshin elementary school in South Korea served as participants. The same students were required to take 4 spelling tests with 1 given every day over the course of 4 days. For…

  15. The πHe3H3 coupling constant estimation using the Chew-Low equation

    International Nuclear Information System (INIS)

    Mach, R.; Nichitiu, F.

    1976-01-01

    A semi-phenomenological analysis of the π +- He 3 elastic scattering at 98, 120, 135 and 156 Mev is presented. An information of the πHe 3 H 3 coupling constant using the Chew-Low plot for the P 33 partial wave is obtained. (author)

  16. Chewing movements altered in the presence of temporomandibular joint internal derangements.

    Science.gov (United States)

    Radke, John C; Kull, Robert S; Sethi, Manminder S

    2014-07-01

    The objectives were to find specific factors that are mathematically distinct between the chewing timings, movement pattern shapes, variability, and movement velocities of: (1) normal asymptomatic subjects and (2) a group of subjects with verified temporomandibular joint (TMJ) internal derangements. Left- and right-sided chewing movement recordings of 28 subjects (34.5 ± 14.0 years) were randomly selected from a large database of patients exhibiting verified unilateral or bilateral TMJ internal derangements. The chewing movements of an age- and gender-matched control group of 20 asymptomatic subjects (32.5 ± 11.6 years, P>0.60) with verified normal TMJ function were also recorded. Means and standard deviations of the opening, closing, turning point, terminal chewing position, and velocity patterns were calculated. A two-tailed Student's t-test with unequal variances was used to compare the parameters between the two groups (alpha = 0.05). The dysfunctional group functioned significantly slower and with greater variability than the control group. The vertical dimension was consistently smaller in the dysfunctional group (Pchewing position was significantly less precise in the dysfunctional group (vertical: Pchewing patterns than the control group. The functional pattern of mastication appears to be significantly altered in the presence of an internal derangement of the TMJ.

  17. Chewing insect predation on artificial caterpillars is related to activity density of ground beetles (Coleoptera: Carabidae)

    DEFF Research Database (Denmark)

    Ferrante, M.; Lövei, G. L.

    2015-01-01

    traps in winter wheat (Triticum aestivum). Forty-six percent (n=756/1637) of the artificial sentinel prey were attacked after 24 h, mostly by chewing insects (88%, n=665/756), and 1102 carabids with a size of ≥15mm were collected. Ground beetles were also the most common predatory group, followed...

  18. A Kinematic Description of the Temporal Characteristics of Jaw Motion for Early Chewing: Preliminary Findings

    Science.gov (United States)

    Wilson, Erin M.; Green, Jordan R.; Weismer, Gary

    2012-01-01

    Purpose: The purpose of this investigation was to describe age- and consistency-related changes in the temporal characteristics of chewing in typically developing children between the ages of 4 and 35 months and adults using high-resolution optically based motion capture technology. Method: Data were collected from 60 participants (48 children, 12…

  19. Genetic diversity analysis of nine chewing cane varieties (lines) and construction of their DNA fingerprints

    Science.gov (United States)

    In order to provide theoretical basis for variety identification and parental selection during sugarcane breeding process, the present study was conducted to analyze genetic diversity of nine chewing cane varieties (lines) and construct their DNA fingerprints. Combining twenty-one SSR molecular mark...

  20. The πHe3H3 coupling constant estimation using the Chew-Low equation

    International Nuclear Information System (INIS)

    Mach, R.; Nichitiu, F.

    1975-01-01

    In this paper it is presented an estimation of the πHe 3 H 3 coupling constant using the Chew-Low equation and a semi-phenomenological analysis of the π -+ He 3 elastic differential cross sections at 98, 120, 135 and 156 MeV

  1. "JCE" Classroom Activity #105. A Sticky Situation: Chewing Gum and Solubility

    Science.gov (United States)

    Montes-Gonzalez, Ingrid; Cintron-Maldonado, Jose A.; Perez-Medina, Ilia E.; Montes-Berrios, Veronica; Roman-Lopez, Saurie N.

    2010-01-01

    In this Activity, students perform several solubility tests using common food items such as chocolate, chewing gum, water, sugar, and oil. From their observations during the Activity, students will initially classify the substances tested as soluble or insoluble. They will then use their understanding of the chemistry of solubility to classify the…

  2. Myrsidea povedai (Phthiraptera: Menoponidae), a new species of chewing louse from Phainoptila melanoxantha (Passeriformes: Bombycillidae)

    Czech Academy of Sciences Publication Activity Database

    Sychra, O.; Kounek, F.; Čapek, Miroslav; Literák, I.

    2011-01-01

    Roč. 97, č. 4 (2011), s. 593-595 ISSN 0022-3395 Institutional research plan: CEZ:AV0Z60930519 Keywords : chewing louse * Phthiraptera * Black- and -yellow Silky-flycatcher * Costa Rica * Myrsidea * Phainoptila melanoxantha Subject RIV: EG - Zoology Impact factor: 1.405, year: 2011

  3. The management of xerostomia in patients on haemodialysis : Comparison of artificial saliva and chewing gum

    NARCIS (Netherlands)

    Bots, CP; Brand, HS; Veerman, ECI; Valentijn-Benz, M; Van Amerongen, BM; Amerongen, AVN; Valentijn, RM; Vos, PI; Bijlsma, JA; ter Wee, PM

    2005-01-01

    Many patients on haemodialysis (HD) therapy suffer from a dry mouth and xerostomia. This can be relieved by mechanical and gustatory stimulation or palliative care. The aim of this crossover study was to investigate the effect and preferences of a sugar-free chewing gum (Freedent White(TM)) and a

  4. The management of xerostomia in patients on haemodialysis: comparison of artificial saliva and chewing gum

    NARCIS (Netherlands)

    Bots, Casper P.; Brand, Henk S.; Veerman, Enno C. I.; Valentijn-Benz, Marianne; van Amerongen, Barbara M.; Nieuw Amerongen, Arie V.; Valentijn, Robert M.; Vos, Pieter F.; Bijlsma, Joost A.; Bezemer, Pieter D.; ter Wee, Piet M.

    2005-01-01

    Many patients on haemodialysis (HD) therapy suffer from a dry mouth and xerostomia. This can be relieved by mechanical and gustatory stimulation or palliative care. The aim of this crossover study was to investigate the effect and preferences of a sugar-free chewing gum (Freedent White) and a

  5. The efficacy of two prototype chewing gums for the removal of extrinsic tooth stain

    NARCIS (Netherlands)

    Ozcan, M; Kulak, Y; Kazazoglu, E

    Aim: To compare the potential efficacy of two prototype chewing gums in extrinsic stain removal on natural teeth. Setting: Dental school clinics. Design: Double-blind, two groups, parallel design. Participants: 76 adult volunteers (32m, 44f, mean age: 20.6 years old). Methods: Oral hard and soft

  6. Effects of short-term xylitol gum chewing on the oral microbiome.

    Science.gov (United States)

    Söderling, Eva; ElSalhy, Mohamed; Honkala, Eino; Fontana, Margherita; Flannagan, Susan; Eckert, George; Kokaras, Alexis; Paster, Bruce; Tolvanen, Mimmi; Honkala, Sisko

    2015-03-01

    The aim of this study was to determine the effects of short-term xylitol gum chewing on the salivary microbiota of children. The study was a randomised, controlled, double-blind trial. Healthy children used xylitol chewing gum (xylitol group, n = 35) or sorbitol chewing gum (control group, n = 38) for 5 weeks. The daily dose of xylitol/sorbitol was approximately 6 g/day. At baseline and at the end of the test period, unstimulated and paraffin-stimulated saliva were collected. The microbial composition of the saliva was assessed using human oral microbe identification microarray (HOMIM). Mutans streptococci (MS) were plate cultured. As judged by HOMIM results, no xylitol-induced changes in the salivary microbiota took place in the xylitol group. In the control group, Veillonella atypica showed a significant decrease (p = 0.0001). The xylitol gum chewing decreased viable counts of MS in both stimulated (p = 0.006) and unstimulated (p = 0.002) saliva, but similar effects were also seen in the control group. The use of xylitol gum decreased MS, in general, but did not change the salivary microbial composition. Short-term consumption of xylitol had no impact on the composition of the salivary microbiota, but resulted in a decrease in the levels of MS.

  7. Effects of Catha edulis on kidney and liver function among chewing ...

    African Journals Online (AJOL)

    Effects of Catha edulis on kidney and liver function among chewing adults in Meru ... socio-cultural tradition in Kenya and as such poses a public health problem. ... Objective: To investigate the possible effects of Catha edulis on the levels of ...

  8. Chewing gum and cognitive performance: a case of a functional food with function but no food?

    Science.gov (United States)

    Scholey, Andrew

    2004-10-01

    Recent reports suggest that enhancement of memory performance while chewing gum is a fairly robust phenomenon. The processes underlying the effect are not known, but may involve glucose delivery, context-dependent effects and arousal mechanisms amongst others. This brief commentary outlines the main findings from these studies and raises some issues regarding interpretation, methodology and future research directions.

  9. Chew the pain away: oral habits to cope with pain and stress and to stimulate cognition

    NARCIS (Netherlands)

    Weijenberg, R.A.F.; Lobbezoo, F.

    2015-01-01

    The acute effects of chewing gum on cognitive performance, stress, and pain have been intensively studied in the last decade. The results have been contradicting, and replication studies proved challenging. Here, we review some of the recent findings of this topic and explore possible explanations

  10. Chew the pain away - Oral habits to cope with pain and stress, and to stimulate cognition?

    NARCIS (Netherlands)

    Weijenberg, R.A.F.; Lobbezoo, F.

    2015-01-01

    The acute effects of chewing gum on cognitive performance, stress, and pain have been intensively studied in the last decade. The results have been contradicting, and replication studies proved challenging. Here, we review some of the recent findings of this topic and explore possible explanations

  11. Effects of chewing gum on driving performance as evaluated by the STISIM driving simulator.

    Science.gov (United States)

    Yoo, Ingyu; Kim, Eun-Joo; Lee, Joo-Hyun

    2015-06-01

    [Purpose] The purpose of this study was to determine the effects of chewing gum on driving performance in a driving simulator. [Subjects] In total, 26 young licensed drivers participated. [Methods] The driving scenario was typical of an urban environment: a single-carriageway, two-way road consisting of a mix of curved and straight sections, with considerable levels of traffic, pedestrians, and parked cars. Mean distance driven above the speed limit, lane position, mean distance driven across the center line, and mean distance driven off the road were used as estimates of brake, accelerator, and steering control. The results were compared with those of a non-chewing gum control condition. [Results] The driving performance while chewing gum was significantly better: the mean distance driven above the speed limit was 26.61% shorter, and the mean distance driven off the road was 31.99% shorter. Lane position and mean distance driven across the center line did not differ significantly between the two conditions. [Conclusion] Chewing gum appears to enhance driving performance during a sustained attention driving task.

  12. Effects of gum chewing on memory and attention: reply to Scholey (2004).

    Science.gov (United States)

    Tucha, Oliver; Mecklinger, Lara; Hammerl, Marianne; Lange, Klaus W

    2004-10-01

    Recent studies have reported varying results regarding cognitive performance while chewing gum. The differences between the results of these studies may be explained by methodological and statistical factors. Future studies are needed to assess various aspects of cognitive functioning using extensive standardised neuropsychological test batteries, adequate experimental designs and appropriate statistical methods.

  13. The areca nut chewing habit and oral squamous cell carcinoma in ...

    African Journals Online (AJOL)

    catechu. The areca nut-chewing habir involves the. Oral and Dental Research Unit, University ofStellenbosch. C. W. VAN WYK, PH.D., F.D.S. R.e.s., B.CH.D. A. PADAYACHEE, M.CH.D, B.D.S.. Institute for Biostatistics and Centre for Molecular and Cellular. Biology, South African Medical Research Council, Parowvallei,. CP.

  14. Energy functions for regularization algorithms

    Science.gov (United States)

    Delingette, H.; Hebert, M.; Ikeuchi, K.

    1991-01-01

    Regularization techniques are widely used for inverse problem solving in computer vision such as surface reconstruction, edge detection, or optical flow estimation. Energy functions used for regularization algorithms measure how smooth a curve or surface is, and to render acceptable solutions these energies must verify certain properties such as invariance with Euclidean transformations or invariance with parameterization. The notion of smoothness energy is extended here to the notion of a differential stabilizer, and it is shown that to void the systematic underestimation of undercurvature for planar curve fitting, it is necessary that circles be the curves of maximum smoothness. A set of stabilizers is proposed that meet this condition as well as invariance with rotation and parameterization.

  15. Physical model of dimensional regularization

    Energy Technology Data Exchange (ETDEWEB)

    Schonfeld, Jonathan F.

    2016-12-15

    We explicitly construct fractals of dimension 4-ε on which dimensional regularization approximates scalar-field-only quantum-field theory amplitudes. The construction does not require fractals to be Lorentz-invariant in any sense, and we argue that there probably is no Lorentz-invariant fractal of dimension greater than 2. We derive dimensional regularization's power-law screening first for fractals obtained by removing voids from 3-dimensional Euclidean space. The derivation applies techniques from elementary dielectric theory. Surprisingly, fractal geometry by itself does not guarantee the appropriate power-law behavior; boundary conditions at fractal voids also play an important role. We then extend the derivation to 4-dimensional Minkowski space. We comment on generalization to non-scalar fields, and speculate about implications for quantum gravity. (orig.)

  16. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  17. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  18. Regularized strings with extrinsic curvature

    International Nuclear Information System (INIS)

    Ambjoern, J.; Durhuus, B.

    1987-07-01

    We analyze models of discretized string theories, where the path integral over world sheet variables is regularized by summing over triangulated surfaces. The inclusion of curvature in the action is a necessity for the scaling of the string tension. We discuss the physical properties of models with extrinsic curvature terms in the action and show that the string tension vanishes at the critical point where the bare extrinsic curvature coupling tends to infinity. Similar results are derived for models with intrinsic curvature. (orig.)

  19. Circuit complexity of regular languages

    Czech Academy of Sciences Publication Activity Database

    Koucký, Michal

    2009-01-01

    Roč. 45, č. 4 (2009), s. 865-879 ISSN 1432-4350 R&D Projects: GA ČR GP201/07/P276; GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10190503 Keywords : regular languages * circuit complexity * upper and lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.726, year: 2009

  20. Evaluation of the content of TiO2 nanoparticles in the coatings of chewing gums.

    Science.gov (United States)

    Dudefoi, William; Terrisse, Hélène; Popa, Aurelian Florin; Gautron, Eric; Humbert, Bernard; Ropers, Marie-Hélène

    2018-02-01

    Titanium dioxide is a metal oxide used as a white pigment in many food categories, including confectionery. Due to differences in the mass fraction of nanoparticles contained in TiO 2 , the estimated intakes of TiO 2 nanoparticles differ by a factor of 10 in the literature. To resolve this problem, a better estimation of the mass of nanoparticles present in food products is needed. In this study, we focused our efforts on chewing gum, which is one of the food products contributing most to the intake of TiO 2 . The coatings of four kinds of chewing gum, where the presence of TiO 2 was confirmed by Raman spectroscopy, were extracted in aqueous phases. The extracts were analysed by transmission electron microscopy (TEM), X-ray diffraction, Fourier Transform Raman spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-AES) to establish their chemical composition, crystallinity and size distribution. The coatings of the four chewing gums differ chemically from each other, and more specifically the amount of TiO 2 varies from one coating to another. TiO 2 particles constitute the entire coating of some chewing gums, whereas for others, TiO 2 particles are embedded in an organic matrix and/or mixed with minerals like calcium carbonate, talc, or magnesium silicate. We found 1.1 ± 0.3 to 17.3 ± 0.9 mg TiO 2 particles per piece of chewing gum, with a mean diameter of 135 ± 42 nm. TiO 2 nanoparticles account for 19 ± 4% of all particles, which represents a mass fraction of 4.2 ± 0.1% on average. The intake of nanoparticles is thus highly dependent on the kind of chewing gum, with an estimated range extending from 0.04 ± 0.01 to 0.81 ± 0.04 mg of nano-TiO 2 per piece of chewing gum. These data should serve to refine the exposure scenario.

  1. EFFECT OF GUM CHEWING ON AIR SWALLOWING, SALIVA SWALLOWING AND BELCHING

    Directory of Open Access Journals (Sweden)

    Ana Cristina Viana da SILVA

    2015-09-01

    Full Text Available BackgroundEructation is a physiologic event which allows gastric venting of swallowed air and most of the time is not perceived as a symptom. This is called gastric belching. Supragastric belching occurs when swallowed air does not reach the stomach and returns by mouth a short time after swallowing. This situation may cause discomfort, life limitations and problems in daily life.ObjectiveOur objective in this investigation was to evaluate if gum chewing increases the frequency of gastric and/or supragastric belches.MethodsEsophageal transit of liquid and gas was evaluated by impedance measurement in 16 patients with complaint of troublesome belching and in 15 controls. The Rome III criteria were used in the diagnosis of troublesome belching. The esophageal transit of liquid and gas was measured at 5 cm, 10 cm, 15 cm and 20 cm from the lower esophageal sphincter. The subjects were evaluated for 1 hour which was divided into three 20-minute periods: (1 while sitting for a 20-minute base period; (2 after the ingestion of yogurt (200 mL, 190 kcal, in which the subjects were evaluated while chewing or not chewing gum; (3 final 20-minute period in which the subjects then inverted the task of chewing or not chewing gum. In gastric belch, the air flowed from the stomach through the esophagus in oral direction and in supragastric belch the air entered the esophagus rapidly from proximal and was expulsed almost immediately in oral direction. Air swallows were characterized by an increase of at least 50% of basal impedance and saliva swallow by a decrease of at least 50% of basal impedance, that progress from proximal to distal esophagus.ResultsIn base period, air swallowing was more frequent in patients than in controls and saliva swallowing was more frequent in controls than in patients. There was no difference between the medians of controls and patients in the number of gastric belches and supragastric belches. In six patients, supragastric belches

  2. Changes in plasma steroids and cytokines levels in betel chewing patients in Taiwan.

    Science.gov (United States)

    Hu, Sindy; Chen, Wen-Chyuan; Hwang, Guey-Shyang; Chen, Szu-Tah; Kuo, Song-Bor; Chen, Yifen; Idova, Galina; Wang, Shyi-Wu

    2016-07-01

    Betel nut is the second largest economic food product in Taiwan. In Southeast Asia, the habit of chewing betel nut seems to be highly correlated with oral submucous fibrosis and oral squamous cell carcinoma. Oral submucous fibrosis is characterized by abnormal accumulation of oral submucous collagen fibers and limitation of mouth opening. Although the mechanism responsible for tissue damage is still unknown, prolonged irritation caused by betel nut and tobacco is considered to be a major factor contributing to the pathogenesis of oral submucous fibrosis. The effect of betel nut chewing on immune system remains unknown. Present study aims to investigate the change of plasma hormones including cortisol, testosterone, and inflammatory cytokine concentrations in male chewing betel nut compared with normal subjects. Heparinized blood was obtained from control group (normal young+mid-aged individuals), betel nut-chewing, and oral cancer male subjects. The study was approved by the Ethics Committee of the Chang-Gung Memorial Hospital. Written informed consent was granted by the patients. Plasma cortisol and testosterone concentrations were detected by commercial enzyme-linked immunosorbent assay (ELISA). The inflammatory cytokines, including interleukin-1β (IL-1β), IL-15, tumor necrosis factor-α (TNF-α), were analyzed by ELISA with commercial monoclonal capture antibodies and polyclonal detection antibodies. The median concentrations of plasma IL-1β, IL-15, and TNF-α were 3.14pg/ml, 3.14pg/ml, and 6.85pg/ml, respectively, in patients with oral cancer, compared with median plasma IL-1β, IL-15, and TNF-α concentration of 2.64pg/ml, 5.86pg/ml, and 5.38pg/ml, respectively, in patients with betel nut-chewing habit. In contrast, the median concentrations of plasma IL-1β, IL-15, and TNF-α in mid-aged males (aged 30-50) were 7.00pg/ml, 10.64pg/ml, and 31.73pg/ml, respectively, compared with median plasma concentration of IL-1β, IL-15, and TNF-α of 4.48pg/ml, 33.36pg

  3. Yauk gyar mann yin (Be a man!): masculinity and betel quid chewing among men in Mandalay, Myanmar.

    Science.gov (United States)

    Moe, Thida; Boonmongkon, Pimpawun; Lin, Chu Fu; Guadamuz, Thomas E

    2016-01-01

    Betel quid chewing is associated with various oral cancers and other health concerns, including reproductive health issues. Nevertheless, the practice is widespread in Myanmar, especially among men. This qualitative study elucidates the gendered aspects of betel quid chewing by examining how it links with masculine ideology among male betel quid chewers in Mandalay, Myanmar. Data were collected through in-depth interviews, focus-group discussions, key-informant interviews and participant observation. The thematic content analysis was guided by Connell's concept of hegemonic masculinity and Butler's notion of gender performativity. The findings indicated that young Mandalay men were drawn to betel quid chewing by the value they gave to satisfying their curiosity, power competition, risk-taking and a display of manliness. Thus, the practice of betel quid chewing, as defined by our participants, was perceived as manly, trendy, stylish and sexually attractive. For adult men, betel quid chewing was a social lubricant that assisted them in talking with clients and co-workers, thus enhancing their economic opportunities with other men. It also helped working-class men to work harder. Betel quid chewing harm-reduction programmes therefore need to be mindful of masculinity issues as well as the economic aspects of betel quid chewing.

  4. Chewing efficiency and maximum bite force with different attachment systems of implant overdentures: a crossover study.

    Science.gov (United States)

    Elsyad, Moustafa Abdou; Khairallah, Ahmed Samir

    2017-06-01

    This crossover study aimed to evaluate and compare chewing efficiency and maximum bite force (MBF) with resilient telescopic and bar attachment systems of implant overdentures in patients with atrophied mandibles. Ten participants with severely resorbed mandibles and persistent denture problems received new maxillary and mandibular conventional dentures (control, CD). After 3 months of adaptation, two implants were inserted in canine region of the mandible. In a quasi-random method, overdentures were connected to the implants with either bar overdentures (BOD) or resilient telescopic overdentures (TOD) attachment systems. Chewing efficiency in terms of unmixed fraction (UF) was measured using chewing gum (after 5, 10, 20, 30 and 50 strokes), and MBF was measured using a bite force transducer. Measurements were performed 3 months after using each of the following prostheses: CD, BOD and TOD. Chewing efficiency and MBF increased significantly with BOD and TOD compared to CD. As the number of chewing cycles increased, the UF decreased. TOD recorded significant higher chewing efficiency and MBF than BOD. Resilient telescopic attachments are associated with increased chewing efficiency and MBF compared bar attachments when used to retain overdentures to the implants in patients with atrophied mandibles. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva

    Directory of Open Access Journals (Sweden)

    Saroea Geoffrey

    2008-08-01

    Full Text Available Abstract Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B on stain removal in an in vitro experiment, when compared with a confectionary whitening chewing gum (C and human saliva (D. Methods Bovine incisors were stained by alternating air exposure and immersion in a broth containing natural pigments such as coffee, tea and oral microorganisms for 10 days. Stained enamel samples were exposed to saliva alone or to the test chewing gums under conditions simulating human mastication. The coloration change of the enamel samples was measured using a spectrophotometer. Measurements were obtained for each specimen (average of three absorbances using the L*a*b scale: lightness (L*, red-green (a and yellow-blue (b. Results Medicated chewing gums (A and B removed a greater amount of visible extrinsic stain, while the confectionary chewing gum with a whitening claim (C had a milder whitening effect as evaluated by quantitative and qualitative assessment. Conclusion The tested Nicotine Replacement Therapy (NRT chewing gums were more effective in the removal of the extrinsic tooth stain. This visible improvement in tooth whitening appearance could strengthen the smokers' motivation to quit smoking.

  6. General inverse problems for regular variation

    DEFF Research Database (Denmark)

    Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan

    2014-01-01

    Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...

  7. Texture-dependent effects of pseudo-chewing sound on perceived food texture and evoked feelings in response to nursing care foods.

    Science.gov (United States)

    Endo, Hiroshi; Ino, Shuichi; Fujisaki, Waka

    2017-09-01

    Because chewing sounds influence perceived food textures, unpleasant textures of texture-modified diets might be improved by chewing sound modulation. Additionally, since inhomogeneous food properties increase perceived sensory intensity, the effects of chewing sound modulation might depend on inhomogeneity. This study examined the influences of texture inhomogeneity on the effects of chewing sound modulation. Three kinds of nursing care foods in two food process types (minced-/puréed-like foods for inhomogeneous/homogeneous texture respectively) were used as sample foods. A pseudo-chewing sound presentation system, using electromyogram signals, was used to modulate chewing sounds. Thirty healthy elderly participants participated in the experiment. In two conditions with and without the pseudo-chewing sound, participants rated the taste, texture, and evoked feelings in response to sample foods. The results showed that inhomogeneity strongly influenced the perception of food texture. Regarding the effects of the pseudo-chewing sound, taste was less influenced, the perceived food texture tended to change in the minced-like foods, and evoked feelings changed in both food process types. Though there were some food-dependent differences in the effects of the pseudo-chewing sound, the presentation of the pseudo-chewing sounds was more effective in foods with an inhomogeneous texture. In addition, it was shown that the pseudo-chewing sound might have positively influenced feelings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The effect of chewing gum's flavor on salivary flow rate and pH.

    Science.gov (United States)

    Karami-Nogourani, Maryam; Kowsari-Isfahan, Raha; Hosseini-Beheshti, Mozhgan

    2011-12-01

    Chewing sugar-free gums is a convenient way to increase salivary flow. Salivary flow increases in response to both gustatory (taste) and mechanical (chewing) stimuli, and chewing gum can provide both of these stimuli. The aim of this study was to compare the effect of five different flavors of sugar-free chewing gum on the salivary flow rate (SFR) and pH. Fifteen dental students volunteered at the same time on six consecutive days, to collect one minute unstimulated saliva. After five minutes, while some volunteers continued to collect only unstimulated saliva, the others asked to start chewing one of the five flavored gums randomly. The flavors were spearmint, cinnamon, watermelon, strawberry, and apple. The whole saliva was collected over time periods of 0 - 1, 1 - 3, and 3 - 6 minutes, and the SFR and pH were also measured. The data were subjected to pair t-test, repeated-measures analysis of variance, and Duncan tests. Compared to the unstimulated rate, all five different flavored gums significantly increased the SFR within six minutes. Although the flow rate peaked during the first minute of stimulation with all five products, it reduced gradually, but still remained above the unstimulated saliva, after six minutes. In the first minute, the strawberry-flavored gums showed the highest weight, yet, it only induced a significantly higher SFR compared to the cinnamon-flavored gums. During one to three minutes, strawberry and apple-flavored gums showed significantly higher SFR, respectively, compared to cinnamon-flavored gums. There were no significant differences in the flow rates elicited by each flavored gum through the three-to-six minute interval, although the spearmint-flavored gums induced slightly higher SFR. Only the spearmint and cinnamon-flavored gum significantly increased the salivary pH. Gum flavor can affect the SFR and special flavors may be advised for different individuals according to their oral conditions.

  9. The release of vitamin C from chewing gum and its effects on supragingival calculus formation.

    Science.gov (United States)

    Lingström, Peter; Fure, Solveig; Dinitzen, Bettina; Fritzne, Christina; Klefbom, Carin; Birkhed, Dowen

    2005-02-01

    The aims of this study were to evaluate (i): whether vitamin C in chewing gum, alone or in combination with carbamide, influences calculus formation, and (ii) whether carbamide affects the release, stability and uptake of vitamin C in a chewing gum. In two test series (Series I and II), 30 subjects, all calculus formers, participated. They were instructed to chew on five (Series I) or 10 (Series II) pieces of gum per day for a period of 3 months. The chewing gums were: vitamin C (60 mg, Series I), non-vitamin C (Series I) and vitamin C + carbamide (30 mg + 30 mg, Series II). In both series, no gum was used as a negative control. Calculus formation was scored on three lingual sites on the six anterior mandibular teeth according to the Volpe-Manhold index. The effect on plaque and gingivitis was also determined. A significant reduction in the total calculus score was observed after the use of vitamin C (33%) and vitamin C + carbamide (12%) gums compared with no gum use; this reduction was most pronounced in the heavy calculus formers. A reduced amount of visible plaque was also observed after use of vitamin C and non-vitamin C gum, but only the vitamin C gum reduced the number of bleeding sites (37%). In a separate study, the release, stability and uptake of vitamin C were evaluated using the iodine titration method in both saliva and urine after exposure to the following gums: vitamin C + carbamide (30 mg + 30 mg) and vitamin C (30 mg). There was no indication that carbamide affected the release, stability or uptake of vitamin C when used in a chewing gum.

  10. Chewing in adolescents with overweight and obesity: An exploratory study with behavioral approach.

    Science.gov (United States)

    Pedroni-Pereira, Aline; Araujo, Darlle Santos; Scudine, Kelly Guedes de Oliveira; Prado, Daniela Galvão de Almeida; Lima, Débora Alves Nunes Leite; Castelo, Paula Midori

    2016-12-01

    Physiological and behavioral aspects of masticatory function may have an impact on nutritional status, which has been little studied. The aim was to perform a comprehensive evaluation of objective, subjective and behavioral aspects of masticatory function in 231 adolescents, aged 14-17 years and compare these parameters between normal-weight (n = 115) and adolescents with overweight/obesity (n = 116). Objective aspects were examined by the Oro-facial Myofunctional Evaluation-expanded protocol (OMES-e), determining the masticatory type, chewing time/frequency, abnormal movements, and other; masticatory performance (color changeable chewing gum) and bite force were also explored. The subjective and behavioral evaluations were assessed using the Quality of Mastication Function Questionnaire, which explores the masticatory behavior and frequency/intensity of difficulty in chewing different types of foods. Results were submitted to normality tests, Chi-square, unpaired t-test and Mann-Whitney. A multiple linear regression model was used to evaluate which of the variables under study contributed to the variation in Percent Body Fat (α = 0.05). The results showed that OMES-e total score differed significantly between groups, that is, individuals with overweight showed more changes in oro-facial myofunctional aspects than normal-weight ones. Unilateral mastication was more frequent among females with overweight/obesity. They also showed greater difficulty on Habits and Fruit domains, reporting the need of adding sauce to the meal to facilitate swallowing and peeling and cutting fruit (apples) in small pieces in order to better chew them. OMES-e total score also showed a significant relationship with Percent Body Fat. Masticatory performance evaluated by chewing gum and bite force did not differ between groups. This study showed that adolescents with excess weight presented changes in masticatory behavior and greater difficulty in performing the masticatory function

  11. Effects of Chewing Different Flavored Gums on Salivary Flow Rate and pH

    Directory of Open Access Journals (Sweden)

    Maryam Karami Nogourani

    2012-01-01

    Full Text Available Chewing gum increases salivary flow rate (SFR and pH, but differences in preferences of gum flavor may influence SFR and pH. The aim of this paper was to assess the effect of five different flavors of sucrose-free chewing gum on the salivary flow rate and pH in healthy dental students in Isfahan, Iran. Fifteen (7 men and 8 women healthy dental student volunteers collected unstimulated saliva and then chewed one of five flavored gums for 6 min. The whole saliva was collected and assessed for 6 consecutive days. After unstimulated saliva was collected, stimulated saliva was collected at interval of 0-1, 1–3, and 3–6 minutes after the start of different flavored chewing gums. The SFR and salivary pH were measured. The SFR increased in all five flavored gums at 1, 3, and 6 minutes after start of chewing gums (<0.001. The flow rate of all products reached peak in the 1st minute of stimulation, except spearmint-flavored gums which reached peak in the 6th minute. In the 1st minute, the strawberry-flavored gums showed the highest SFR. During 1–3 minutes, strawberry- and apple-flavored gums showed higher SFR, respectively. Only the spearmint- and cinnamon-flavored gum significantly increased salivary pH. Gum flavored can affect the SFR and pH and special flavors can be advised for different individuals according to their oral conditions.

  12. Sugar-free chewing gum and dental caries: a systematic review

    Directory of Open Access Journals (Sweden)

    Steffen Mickenautsch

    2007-04-01

    Full Text Available OBJECTIVE: To appraise existing evidence for a therapeutic / anti-cariogenic effect of sugar-free chewing gum for patients. METHOD: 9 English and 2 Portuguese databases were searched using English and Portuguese keywords. Relevant articles in English, German, Portuguese and Spanish were included for review. Trials were excluded on lack of randomisation, control group, blinding and baseline data, drop out rate >33%, no statistical adjustment of baseline differences and no assessment of clinically important outcomes. Reviews were excluded on lack of information, article selection criteria, search strategy followed, search keywords, searched databases or lack of study-by-study critique tables. In cases of multiple reports from the same study, the report covering the longest period was included. Two reviewers independently reviewed and assessed the quality of accepted articles. RESULTS: Thirty-nine articles were included for review. Thirty were excluded and 9 accepted. Of the 9 accepted, 2 trials of reasonable and good evidence value did not demonstrate any anti-cariogenic effect of sugar-free chewing gum. However, 7 articles, with 1 of strong, and 6 of good evidence value, demonstrated anti-cariogenic effects of chewing Sorbitol, Xylitol or Sorbitol/Xylitol gum. This effect can be ascribed to saliva stimulation through the chewing process, particularly when gum is used immediately after meals; the lack of sucrose and the inability of bacteria to metabolize polyols into acids. Conclusion: The evidence suggests that sugar-free chewing gum has a caries-reducing effect. Further well-designed randomised trials are needed to confirm these findings.

  13. Probiotic capsules and xylitol chewing gum to manage symptoms of pharyngitis: a randomized controlled factorial trial.

    Science.gov (United States)

    Little, Paul; Stuart, Beth; Wingrove, Zoe; Mullee, Mark; Thomas, Tammy; Johnson, Sophie; Leydon, Gerry; Richards-Hall, Samantha; Williamson, Ian; Yao, Lily; Zhu, Shihua; Moore, Michael

    2017-12-18

    Reducing the use of antibiotics for upper respiratory tract infections is needed to limit the global threat of antibiotic resistance. We estimated the effectiveness of probiotics and xylitol for the management of pharyngitis. In this parallel-group factorial randomized controlled trial, participants in primary care (aged 3 years or older) with pharyngitis underwent randomization by nurses who provided sequential intervention packs. Pack contents for 3 kinds of material and advice were previously determined by computer-generated random numbers: no chewing gum, xylitol-based chewing gum (15% xylitol; 5 pieces daily) and sorbitol gum (5 pieces daily). Half of each group were also randomly assigned to receive either probiotic capsules (containing 24 × 10 9 colony-forming units of lactobacilli and bifidobacteria) or placebo. The primary outcome was mean self-reported severity of sore throat and difficulty swallowing (scale 0-6) in the first 3 days. We used multiple imputation to avoid the assumption that data were missing completely at random. A total of 1009 individuals consented, 934 completed the baseline assessment, and 689 provided complete data for the primary outcome. Probiotics were not effective in reducing the severity of symptoms: mean severity scores 2.75 with no probiotic and 2.78 with probiotic (adjusted difference -0.001, 95% confidence interval [CI] -0.24 to 0.24). Chewing gum was also ineffective: mean severity scores 2.73 without gum, 2.72 with sorbitol gum (adjusted difference 0.07, 95% CI -0.23 to 0.37) and 2.73 with xylitol gum (adjusted difference 0.01, 95% CI -0.29 to 0.30). None of the secondary outcomes differed significantly between groups, and no harms were reported. Neither probiotics nor advice to chew xylitol-based chewing gum was effective for managing pharyngitis. Trial registration: ISRCTN, no. ISRCTN51472596. © 2017 Joule Inc. or its licensors.

  14. The association between hyperuricemia and betel nut chewing in Taiwanese men: a cross-sectional study.

    Science.gov (United States)

    Tai, Tsai-Sung; Hsu, Chih-Cheng; Pai, Hsiang-Chu; Liu, Wen-Hsin; Hsu, Yueh-Han

    2013-12-05

    Studies have associated betel nut chewing with cancers, metabolic syndrome, cardiovascular disorders, chronic kidney disease, and proteinuria. This study investigated whether hyperuricemia is associated with betel nut chewing in men who participated in a health check-up program. From hospital records, we identified a total of 11,991 men who participated in the health check-up program from 2003 to 2009. They were divided into hyperuricemic group and non-hyperuricemic group. Laboratory tests, medical history, and status of cigarette smoking, alcohol consumption, and betel nut chewing were compared between the 2 groups. We calculated odds ratio (OR) and 95% confidence interval (CI) of hyperuricemia in association with betel nut consumption and other factors. Compared with the non-hyperuricemic group, the hyperuricemic group was slightly older (59.4 vs. 58.6 years) but less prevalent with betel nut use (11.8 vs. 13.6%, p = 0.003). Multivariable logistic regression analysis showed that hyperuricemia was negatively associated with betel nut chewing (OR 0.75, 95% CI 0.66-0.84), older age (OR 0.84, 95% CI 0.77-0.93), and diabetes mellitus (OR 0.57, 95% CI 0.50-0.64). On the other hand, hyperuricemia was positively associated with body mass index (OR 1.75, 95% CI 1.62-1.90), drinking (OR 1.36, 95% CI 1.25-1.49), hypertension (OR 1.41, 95% CI 1.30-1.52), mixed hyperlipidemia (OR 1.84, 95% CI 1.33-2.54), chronic kidney disease (OR 3.28, 95% CI 2.94-3.65), and proteinuria (OR 1.22, 95% CI 1.08-1.38). Smoking, hypercholesterolemia, and hypertriglyceridemia had no significant association with hyperuricemia. Our data suggest that betel nut chewing is negatively associated with hyperuricemia.

  15. Factors affecting commencement and cessation of betel quid chewing behaviour in Malaysian adults

    Directory of Open Access Journals (Sweden)

    Handa Yujiro

    2011-02-01

    Full Text Available Abstract Background Betel quid chewing is a common habit widely practiced in Southern Asian populations. However, variations are seen in the content of a betel quid across the different countries. Factors associated with commencement and cessation of this habit has been numerously studied. Unfortunately, data on Malaysian population is non-existent. This study aims to determine the factors associated with the inception and also cessation of betel quid chewing behaviour among Malaysian adults. Method This study is part of a nationwide survey on oral mucosal lesions carried out among 11,697 adults in all fourteen states in Malaysia. The questionnaire included sociodemographic information and details on betel quid chewing habit such as duration, type and frequency. The Kaplan-Meier estimates were calculated and plotted to compare the rates for the commencement and cessation of betel quid chewing behaviour. Cox proportional hazard regression models were used to calculate the hazard rate ratios for factors related to commencement or cessation of this habit. Results Of the total subjects, 8.2% were found to be betel quid chewers. This habit was more prevalent among females and, in terms of ethnicity, among the Indians and the Indigenous people of Sabah and Sarawak. Cessation of this habit was more commonly seen among males and the Chinese. Females were found to be significantly more likely to start (p Conclusion Factors that influence the development and cessation of this behaviour are gender, age, ethnicity, and also history of smoking habit while frequency and type of quid chewed are important factors for cessation of this habit.

  16. Acute effects of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers

    Directory of Open Access Journals (Sweden)

    Vikas Thakran

    2015-01-01

    Full Text Available Background: Long-term adverse cardiovascular effects of smokeless tobacco are well established, however, the effect of chewing tobacco on coronary microcirculation and hemodynamic have not been studied. We intended to analyze the acute effect of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers with stable coronary artery disease undergoing elective percutaneous coronary intervention (PCI. Materials and Methods: We prospectively enrolled seven habitual tobacco chewers with stable coronary artery disease with single vessel disease or double vessel disease satisfying the criteria for elective PCI. Patients were instructed to keep 1 g of crushed dried tobacco leaves in the mouth after a successful PCI. Lesion in last stented vessels was evaluated for fractional flow reserve (FFR, coronary flow reserve (CFR, and index of microcirculatory resistance (IMR post-PCI, after 15 min and 30 min of tobacco chewing along with the measurement of serum cotinine levels. Results: Oral tobacco led to high levels of cotinine in the majority of patients. There was an insignificant rise in heart rate, systolic and diastolic blood pressure following tobacco consumption. Baseline CFR (median 1.6, range 1.1–5.5 was low in tobacco chewers after PCI even after optimum FFR (0.9 ± 0.05 in the majority of patients suggesting abnormal microvascular hemodynamics (high IMR in 3 patients, overall median 14.2, range 7–36.2. However, there was no significant change in the estimated CFR or IMR values following tobacco chewing. One patient had bradycardia and hypotension which may be related to vagal reaction or acute nicotine poisoning. Conclusion: Tobacco chewers have abnormal coronary microcirculation hemodynamics even following a successful PCI. However, the coronary micocirculation and hemodynamics do not change acutely following tobacco chewing despite high serum cotinine concentrations.

  17. Regularized Statistical Analysis of Anatomy

    DEFF Research Database (Denmark)

    Sjöstrand, Karl

    2007-01-01

    This thesis presents the application and development of regularized methods for the statistical analysis of anatomical structures. Focus is on structure-function relationships in the human brain, such as the connection between early onset of Alzheimer’s disease and shape changes of the corpus...... and mind. Statistics represents a quintessential part of such investigations as they are preluded by a clinical hypothesis that must be verified based on observed data. The massive amounts of image data produced in each examination pose an important and interesting statistical challenge...... efficient algorithms which make the analysis of large data sets feasible, and gives examples of applications....

  18. Regularization methods in Banach spaces

    CERN Document Server

    Schuster, Thomas; Hofmann, Bernd; Kazimierski, Kamil S

    2012-01-01

    Regularization methods aimed at finding stable approximate solutions are a necessary tool to tackle inverse and ill-posed problems. Usually the mathematical model of an inverse problem consists of an operator equation of the first kind and often the associated forward operator acts between Hilbert spaces. However, for numerous problems the reasons for using a Hilbert space setting seem to be based rather on conventions than on an approprimate and realistic model choice, so often a Banach space setting would be closer to reality. Furthermore, sparsity constraints using general Lp-norms or the B

  19. Academic Training Lecture - Regular Programme

    CERN Multimedia

    PH Department

    2011-01-01

    Regular Lecture Programme 9 May 2011 ACT Lectures on Detectors - Inner Tracking Detectors by Pippa Wells (CERN) 10 May 2011 ACT Lectures on Detectors - Calorimeters (2/5) by Philippe Bloch (CERN) 11 May 2011 ACT Lectures on Detectors - Muon systems (3/5) by Kerstin Hoepfner (RWTH Aachen) 12 May 2011 ACT Lectures on Detectors - Particle Identification and Forward Detectors by Peter Krizan (University of Ljubljana and J. Stefan Institute, Ljubljana, Slovenia) 13 May 2011 ACT Lectures on Detectors - Trigger and Data Acquisition (5/5) by Dr. Brian Petersen (CERN) from 11:00 to 12:00 at CERN ( Bldg. 222-R-001 - Filtration Plant )

  20. RES: Regularized Stochastic BFGS Algorithm

    Science.gov (United States)

    Mokhtari, Aryan; Ribeiro, Alejandro

    2014-12-01

    RES, a regularized stochastic version of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton method is proposed to solve convex optimization problems with stochastic objectives. The use of stochastic gradient descent algorithms is widespread, but the number of iterations required to approximate optimal arguments can be prohibitive in high dimensional problems. Application of second order methods, on the other hand, is impracticable because computation of objective function Hessian inverses incurs excessive computational cost. BFGS modifies gradient descent by introducing a Hessian approximation matrix computed from finite gradient differences. RES utilizes stochastic gradients in lieu of deterministic gradients for both, the determination of descent directions and the approximation of the objective function's curvature. Since stochastic gradients can be computed at manageable computational cost RES is realizable and retains the convergence rate advantages of its deterministic counterparts. Convergence results show that lower and upper bounds on the Hessian egeinvalues of the sample functions are sufficient to guarantee convergence to optimal arguments. Numerical experiments showcase reductions in convergence time relative to stochastic gradient descent algorithms and non-regularized stochastic versions of BFGS. An application of RES to the implementation of support vector machines is developed.

  1. Regularized Label Relaxation Linear Regression.

    Science.gov (United States)

    Fang, Xiaozhao; Xu, Yong; Li, Xuelong; Lai, Zhihui; Wong, Wai Keung; Fang, Bingwu

    2018-04-01

    Linear regression (LR) and some of its variants have been widely used for classification problems. Most of these methods assume that during the learning phase, the training samples can be exactly transformed into a strict binary label matrix, which has too little freedom to fit the labels adequately. To address this problem, in this paper, we propose a novel regularized label relaxation LR method, which has the following notable characteristics. First, the proposed method relaxes the strict binary label matrix into a slack variable matrix by introducing a nonnegative label relaxation matrix into LR, which provides more freedom to fit the labels and simultaneously enlarges the margins between different classes as much as possible. Second, the proposed method constructs the class compactness graph based on manifold learning and uses it as the regularization item to avoid the problem of overfitting. The class compactness graph is used to ensure that the samples sharing the same labels can be kept close after they are transformed. Two different algorithms, which are, respectively, based on -norm and -norm loss functions are devised. These two algorithms have compact closed-form solutions in each iteration so that they are easily implemented. Extensive experiments show that these two algorithms outperform the state-of-the-art algorithms in terms of the classification accuracy and running time.

  2. Evaluation of trace elements in chewing tobacco and snuff using instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS)

    International Nuclear Information System (INIS)

    Waheed, S.; Siddique, N.; Rahman, S.

    2009-01-01

    Nine samples of chewing tobacco, snuff, tobacco leaf and ash were analyzed using Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS). Almost all samples of chewing tobacco and snuff studied in this work contain substantial amounts of Mg, Mn, Na, K. V. Sc, Rb and Fe. Furthermore, varying amounts of Al, Ba, Ca, Ce, Co and Zn were also detected in all tobacco samples. Of the toxic elements which were determined using INAA. As, Sb and Hg were quantified in only few tobacco samples. However, other toxic elements, which were determined using AAS, such as Cu, Pb and Cd were detected in almost all samples of chewing tobacco and snuff. The concentration of majority of the detected elements is high in ash samples which imply that most elements in chewing tobacco and snuff may originate from the addition of ash. (orig.)

  3. Evaluation of trace elements in chewing tobacco and snuff using instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Waheed, S.; Siddique, N.; Rahman, S. [Chemistry Div., Directorate of Science, Pakistan Inst. of Nuclear Science and Tech., Islamabad (Pakistan)

    2009-07-01

    Nine samples of chewing tobacco, snuff, tobacco leaf and ash were analyzed using Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS). Almost all samples of chewing tobacco and snuff studied in this work contain substantial amounts of Mg, Mn, Na, K. V. Sc, Rb and Fe. Furthermore, varying amounts of Al, Ba, Ca, Ce, Co and Zn were also detected in all tobacco samples. Of the toxic elements which were determined using INAA. As, Sb and Hg were quantified in only few tobacco samples. However, other toxic elements, which were determined using AAS, such as Cu, Pb and Cd were detected in almost all samples of chewing tobacco and snuff. The concentration of majority of the detected elements is high in ash samples which imply that most elements in chewing tobacco and snuff may originate from the addition of ash. (orig.)

  4. Additional foraging elements reduce abnormal behaviour – fur-chewing and stereotypic behaviour – in farmed mink (Neovison vison)

    DEFF Research Database (Denmark)

    Malmkvist, Jens; Palme, Rupert; Svendsen, Pernille Maj

    2013-01-01

    We investigated whether provision of additional appetitive and consummatory elements of foraging reduces baseline stress and abnormal behaviour – in terms of fur-chewing and stereotypic behaviour – in farmed mink. We studied 200 juveniles (n = 100 females and 100 males) during the 5-month growth......; (iii) CONS, chunky feed (parts up to 42 mm), replacing conventional feed; (iv) BOTH, access to both biting ropes and chunky feed. In growing mink, biting ropes reduced fur-chewing (P = 0.044) and chunky feed reduced stereotypic behaviour (P = 0.038) and fur-chewing in female mink (P = 0.019). During......, stereotypic behaviour was reduced by provision of chunky feed, increasing the consummatory element in daily foraging. Fur-chewing was reduced upon access to either biting ropes or chunky feed in female mink throughout the study. Our findings support frustrated foraging, mainly consummatory, behind abnormal...

  5. Chewing suppresses the stress-induced increase in the number of pERK-immunoreactive cells in the periaqueductal grey.

    Science.gov (United States)

    Yamada, Kentaro; Narimatsu, Yuri; Ono, Yumie; Sasaguri, Ken-Ichi; Onozuka, Minoru; Kawata, Toshitsugu; Yamamoto, Toshiharu

    2015-07-10

    We investigated the effects of chewing under immobilization stress on the periaqueductal gray (PAG) matter using phosphorylated extracellular signal-regulated kinase (pERK) as a marker of responding cells. Immobilization stress increased pERK-immunoreactive cells in the PAG. Among four subdivisions of the PAG, the increase of immunoreactive cells was remarkable in the dorsolateral and ventrolateral subdivisions. However, increase of pERK-immunoreactive cells by the immobilization stress was not so evident in the dorsomedial and lateral subdivisions. The chewing under immobilization stress prevented the stress-induced increase of pERK-immunoreactive cells in the dorsolateral and ventrolateral subdivisions with statistical significances (p<0.05). Again, chewing effects on pERK-immunoreactive cells were not visible in the dorsomedial and lateral subdivisions. These results suggest that the chewing alleviates the PAG (dorsolateral and ventrolateral subdivisions) responses to stress. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Site-specific and synergistic stimulation of methylation on the bacterial chemotaxis receptor Tsr by serine and CheW

    Directory of Open Access Journals (Sweden)

    Weis Robert M

    2005-03-01

    Full Text Available Abstract Background Specific glutamates in the methyl-accepting chemotaxis proteins (MCPs of Escherichia coli are modified during sensory adaptation. Attractants that bind to MCPs are known to increase the rate of receptor modification, as with serine and the serine receptor (Tsr, which contributes to an increase in the steady-state (adapted methylation level. However, MCPs form ternary complexes with two cytoplasmic signaling proteins, the kinase (CheA and an adaptor protein (CheW, but their influences on receptor methylation are unknown. Here, the influence of CheW on the rate of Tsr methylation has been studied to identify contributions to the process of adaptation. Results Methyl group incorporation was measured in a series of membrane samples in which the Tsr molecules were engineered to have one available methyl-accepting glutamate residue (297, 304, 311 or 493. The relative rates at these sites (0.14, 0.05, 0.05 and 1, respectively differed from those found previously for the aspartate receptor (Tar, which was in part due to sequence differences between Tar and Tsr near site four. The addition of CheW generated unexpectedly large and site-specific rate increases, equal to or larger than the increases produced by serine. The increases produced by serine and CheW (added separately were the largest at site one, ~3 and 6-fold, respectively, and the least at site four, no change and ~2-fold, respectively. The rate increases were even larger when serine and CheW were added together, larger than the sums of the increases produced by serine and CheW added separately (except site four. This resulted in substantially larger serine-stimulated increases when CheW was present. Also, CheW enhanced methylation rates when either two or all four sites were available. Conclusion The increase in the rate of receptor methylation upon CheW binding contributes significantly to the ligand specificity and kinetics of sensory adaptation. The synergistic effect of

  7. Evaluation of chewing ability and its relationship with activities of daily living, depression, cognitive status and food intake in the community-dwelling elderly.

    Science.gov (United States)

    Kimura, Yumi; Ogawa, Hiroshi; Yoshihara, Akihiro; Yamaga, Takayuki; Takiguchi, Tomoya; Wada, Taizo; Sakamoto, Ryota; Ishimoto, Yasuko; Fukutomi, Eriko; Chen, Wenling; Fujisawa, Michiko; Okumiya, Kiyohito; Otsuka, Kuniaki; Miyazaki, Hideo; Matsubayashi, Kozo

    2013-07-01

    The aim of this study was to assess chewing ability using color-changeable chewing gum and to show the association between chewing ability and geriatric functions, as well as dietary status in the community-dwelling elderly. The study population consisted of 269 community-dwelling elderly aged ≥ 75 living in Tosa, Japan. Assessment of chewing ability was carried out by a dentist using color-changeable chewing gum. Activities of daily living (ADL), depression and subjective quality of life (QOL) were assessed by questionnaire. Cognitive status was assessed by; Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale-Revised (HDS-R) and Frontal Assessment Battery (FAB) during the check-up. Food diversity was assessed using the 11-item Food Diversity Score Kyoto (FDSK-11). Number of teeth was significantly related to chewing ability (Pchewing ability had significantly lower ADL scores in the items of self-maintenance (P=0.029) and intellectual activity (P=0.021). There was a significant association between low chewing ability and depression (Pchewing ability; MMSE (P=0.022), HDSR (P=0.017) and FAB (P=0.002). The participants with low chewing ability had lower food variety (Pchewing ability. Low chewing ability evaluated by color-changeable gum was associated with lower ADL, lower cognitive functioning, depression and food insufficiency in the community-dwelling elderly. More attention should be paid to assessing chewing ability of elderly persons in community settings. © 2012 Japan Geriatrics Society.

  8. Can school-based oral health education and a sugar-free chewing gum program improve oral health?

    DEFF Research Database (Denmark)

    Peng, Bin; Petersen, Poul Erik; Bian, Zhuan

    2004-01-01

    The purpose of the study was to assess the outcome of school-based oral health education (OHE) and a sugar-free chewing gum program on the oral health status of children in terms of reduced caries increment and gingival bleeding over a period of 2 years. Nine primary schools randomly chosen from......'s oral hygiene; in certain circumstances children may benefit from using polyol-containing chewing gum in terms of reduced dental caries....

  9. Effects of gum chewing on postoperative bowel motility after caesarean section: a meta-analysis of randomised controlled trials.

    Science.gov (United States)

    Zhu, Y-P; Wang, W-J; Zhang, S-L; Dai, B; Ye, D-W

    2014-06-01

    Gum chewing has been reported to enhance bowel motility and reduce postoperative ileus (POI). However, the efficacy remains imprecise for women following caesarean section. To summarise and evaluate the current evidence for postoperative gum chewing on the recovery of bowel function following caesarean section. We searched studies from the following electronic databases: PubMed, EMBASE, SCOPUS and Cochrane Library from inception to 30 May 2013. We included randomised controlled trials (RCTs) of women after caesarean section; these RCTs should compared gum chewing with no gum chewing and reported on at least one of the outcomes: time to flatus, time to bowel sound, time to passing stool and length of hospital stay (LOS). Study outcomes were presented as mean differences (for continuous data) with 95% confidence interval (95% CI). The risk of bias in the study results was assessed using the assessment tool from the Cochrane Handbook. Six RCTs including 939 women were included in our meta-analysis. The pooled results demonstrated that gum chewing is superior to no gum chewing with a reduction of 6.42 hours (95% CI -7.55 to -5.29) for time to first flatus, 3.62 hours (95% CI -6.41 to -0.83) for time to first bowel sound, 6.58 hours (95% CI -10.10 to -3.07) for time to first stool and 5.94 hours (95% CI -9.39 to -2.49) for LOS. In addition, no evidence emerged for any side effects caused by gum chewing. The current evidence suggests that gum chewing is associated with early recovery of bowel motility and shorter LOS for women after caesarean section. This safe and inexpensive intervention should be included in routine postoperative care following a caesarean section. © 2014 Royal College of Obstetricians and Gynaecologists.

  10. Comparative study of essential and toxic trace elements in chewing tobacco and pan masalas by INAA and AAS

    International Nuclear Information System (INIS)

    Paul Choudhury, R.; Garg, A.N.; Nair, A.G.C.; Reddy, A.V.R.

    2005-01-01

    Concentrations of about 25 elements were measured in 10 samples of chewing tobacco and 5 of pan masalas by INAA and AAS. Reference Materials (RMs) were analysed for quality assurance and data validation. It is observed that besides many essential elements (Fe, Cu, Zn, P, Ca, Mg), several toxic elements such as As, Sb, Hg, Ni and Pb are also present in significant amounts and are likely to be swallowed along with saliva while chewing. (author)

  11. Process development for spray drying of sticky pharmaceuticals; case study of bioadhesive nicotine microparticles for compressed medicated chewing gum

    DEFF Research Database (Denmark)

    Sander, Camilla; Nielsen, Henrik Stillhof; Søgaard, Susanne Roslev

    2013-01-01

    Spray drying of pharmaceutical compounds with sticky properties is a challenging task and may require substantial time and resources. By including small-scale studies of single droplet drying kinetics a relatively high number of experiments with less material is allowed. This means one can constr...... chewing gum. By illustration of initial studies on single droplet drying kinetics, subsequent characterization of microparticles, and final characterization of compressed chewing gum this paper summarizes the entire development process....

  12. Dental status and self-assessed chewing ability in 70- and 80-year-old subjects in Sweden.

    Science.gov (United States)

    Unell, L; Johansson, A; Ekbäck, G; Ordell, S; Carlsson, G E

    2015-09-01

    The objective was to compare two cohorts of elderly people, 70 and 80 years old, with respect to dental status and self-assessed chewing ability. The hypotheses were as follows: (i) dental status is associated with self-assessed chewing ability; (ii) chewing ability is poorer among the 80- than the 70-year-old subjects. Identical questionnaires were in 2012 sent to all subjects born in 1942 and 1932, living in two Swedish counties. The response rate was 70.1% resulting in samples of 5697 70- and 2922 80-year-old subjects. Answers to questions on self-assessed chewing ability, dental status and some other factors have been analysed. Dental status varied but was in general good; 72% of the 70- and 60% of the 80-year-old subjects reported that they had all or only few missing teeth. Rate of edentulism was 3% and 7%, respectively. Removable partial dentures were reported by 6% and 10%, respectively, implant treatment by 13% in both cohorts. Self-assessed chewing ability was mostly good and correlated with the number of teeth (Spearman rho = 0.46). A majority of the edentulous subjects assessed their chewing ability as very or fairly good. Logistic regression showed that self-assessed chewing ability was significantly associated with a number of dental variables but also with general health. In conclusion, dental status was relatively good at both ages but somewhat poorer in the older cohort. Dental status, some other dental variables and being healthy were in both age groups significantly associated with self-assessed chewing ability. © 2015 John Wiley & Sons Ltd.

  13. In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva

    OpenAIRE

    Moore, Michael; Hasler-Nguyen, Nathalie; Saroea, Geoffrey

    2008-01-01

    Abstract Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B) on stain removal in an in vitro experiment, when compared with a confectionary whi...

  14. Effects of gum chewing exercises on saliva secretion and occlusal force in community-dwelling elderly individuals: A pilot study.

    Science.gov (United States)

    Nakagawa, Kazuharu; Matsuo, Koichiro; Takagi, Daisuke; Morita, Yu; Ooka, Takafumi; Hironaka, Shouji; Mukai, Yoshiharu

    2017-01-01

    Elderly individuals face the risk of reductions in saliva secretion and occlusal force caused by systemic diseases or medications that can eventually result in malnutrition and systemic complications. We tested the hypothesis that regular gum chewing exercises (GCE) would enhance saliva secretion and occlusal force in an elderly population. A total of 12 community-dwelling elderly individuals (3 men and 9 women) participated in this study after providing informed consent. Participants carried out GCE regimens using a soft gum (GCE-S) or hard gum (GCE-H) for 2 weeks each, with a 2-week rest period between trials. Mucosal moisture on the tongue surface, resting saliva, and occlusal force were measured before and after each test gum, and changes in parameters at relevant time-points were statistically analyzed. Differences in each measurement item were assessed using the Friedman test for before and after the GCE. We used the Holm's correction for multiple comparisons if the Friedman test results were significant. The critical value for rejecting the null hypothesis was set at P GCE-S, returned to baseline levels during the rest period and significantly increased again after GCE-H. Mucosal moisture and occlusal force followed a similar trend, with a significant rise after GCE-H. The results of the present study suggest that GCE can increase resting saliva secretion and occlusal force in elderly individuals. Further investigations are required on the appropriate use of soft and hard gums to address oral frailty in elderly individuals. Geriatr Gerontol Int 2017; 17: 48-53. © 2015 The Authors. Geriatrics & Gerontology International published by Wiley Publishing Asia Pty Ltd on behalf of Japan Geriatrics Society.

  15. From inactive to regular jogger

    DEFF Research Database (Denmark)

    Lund-Cramer, Pernille; Brinkmann Løite, Vibeke; Bredahl, Thomas Viskum Gjelstrup

    study was conducted using individual semi-structured interviews on how a successful long-term behavior change had been achieved. Ten informants were purposely selected from participants in the DANO-RUN research project (7 men, 3 women, average age 41.5). Interviews were performed on the basis of Theory...... of Planned Behavior (TPB) and The Transtheoretical Model (TTM). Coding and analysis of interviews were performed using NVivo 10 software. Results TPB: During the behavior change process, the intention to jogging shifted from a focus on weight loss and improved fitness to both physical health, psychological......Title From inactive to regular jogger - a qualitative study of achieved behavioral change among recreational joggers Authors Pernille Lund-Cramer & Vibeke Brinkmann Løite Purpose Despite extensive knowledge of barriers to physical activity, most interventions promoting physical activity have proven...

  16. Influence of posterior dental arch length on brain activity during chewing in patients with mandibular distal extension removable partial dentures.

    Science.gov (United States)

    Shoi, K; Fueki, K; Usui, N; Taira, M; Wakabayashi, N

    2014-07-01

    It is well known that shortened dental arch decreases masticatory function. However, its potential to change brain activity during mastication is unknown. The present study investigates the effect of a shortened posterior dental arch with mandibular removable partial dentures (RPDs) on brain activity during gum chewing. Eleven subjects with missing mandibular molars (mean age, 66.1 years) on both sides received experimental RPDs with interchangeable artificial molars in a crossover trial design. Brain activity during gum chewing with RPDs containing (full dental arch) and lacking artificial molars (shortened dental arch) was measured using functional magnetic resonance imaging. Additionally, masticatory function was evaluated for each dental arch type. Food comminuting and mixing ability and the perceived chewing ability were significantly lower in subjects with a shortened dental arch than those with a full dental arch (P chewing with the full dental arch occurred in the middle frontal gyrus, primary sensorimotor cortex extending to the pre-central gyrus, supplementary motor area, putamen, insula and cerebellum. However, middle frontal gyrus activation was not observed during gum chewing with the shortened dental arch. These results suggest that shortened dental arch affects human brain activity in the middle frontal gyrus during gum chewing, and the decreased middle frontal gyrus activation may be associated with decreased masticatory function. © 2014 John Wiley & Sons Ltd.

  17. Chewing ameliorates stress-induced suppression of spatial memory by increasing glucocorticoid receptor expression in the hippocampus.

    Science.gov (United States)

    Miyake, Shinjiro; Yoshikawa, Gota; Yamada, Kentaro; Sasaguri, Ken-Ichi; Yamamoto, Toshiharu; Onozuka, Minoru; Sato, Sadao

    2012-03-29

    Chewing alters hypothalamic-pituitary-adrenal axis function and improves the ability to cope with stress in rodents. Given that stress negatively influences hippocampus-dependent learning and memory, we aimed to elucidate whether masticatory movements, namely chewing, improve the stress-induced impairment of spatial memory in conjunction with increased hippocampal glucocorticoid receptor expression. Male Sprague-Dawley rats were subjected to restraint stress by immobilization for 2h: the stress with chewing (SC) group were allowed to chew on a wooden stick during the latter half of the immobilization period, whereas the stress without chewing (ST) group were not allowed to do so. Performance in the Morris water maze test was significantly impaired in the ST group compared with the SC group. Further, the numbers of glucocorticoid receptor immunopositive neurons in the hippocampal cornu ammonis 1 region were significantly lower in the ST group than in the control and SC groups. The control and SC rats showed no significant differences in both the water maze performance and the numbers of glucocorticoid receptor-immunopositive neurons. The immunohistochemical finding correlated with the performance in the water maze test. These results suggest that chewing is a behavioral mechanism to cope with stress by increasing hippocampal glucocorticoid receptor expression. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Clinical evidence of field cancerization in patients with oral cavity cancer in a betel quid chewing area.

    Science.gov (United States)

    Liao, Chun-Ta; Wallace, Christopher G; Lee, Li-Yu; Hsueh, Chuen; Lin, Chien-Yu; Fan, Kang-Hsing; Wang, Hung-Ming; Ng, Shu-Hang; Lin, Chih-Hung; Tsao, Chung-Kan; Chen, I-How; Huang, Shiang-Fu; Kang, Chung-Jan; Yen, Tzu-Chen

    2014-08-01

    We sought to investigate whether there is evidence of field cancerization in patients with oral cavity squamous cell carcinoma (OSCC) enrolled in a betel quid chewing area. We also assessed whether betel quid chewing is an independent risk factor for field cancerization in OSCC patients. We retrospectively examined the records of 1570 OSCC patients who underwent radical tumor resection between 1996 and 2011. A total of 1243 study participants (79%) had a positive history of betel quid chewing before surgery. Of the 767 patients treated with surgery alone, 599 (78%) were preoperative chewers, whereas a history of preoperative betel quid chewing was identified in 644 (80%) of the 803 patients who received adjuvant therapy. The 5-year control, survival, and second primary tumors (SPTs) rates served as the main outcome measures. Regardless of the treatment modality, more than 70% of the SPTs were located in the oral cavity or soft palate. Despite a similar risk profile in terms of tumor depth, lymph node metastasis, and pathological margin status, preoperative chewers showed a significantly higher incidence of 5-year SPTs and local recurrences compared with non-chewers. Moreover, multivariate analysis demonstrated that preoperative betel quid chewing was an independent prognostic factor for 5-year local control and SPTs occurrence rates. Our results demonstrate that preoperative betel quid chewers had a higher incidence of local recurrence and SPTs than non-chewers, suggesting that field cancerization may occur in OSCC patients with a history of betel quid chewing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Tessellating the Sphere with Regular Polygons

    Science.gov (United States)

    Soto-Johnson, Hortensia; Bechthold, Dawn

    2004-01-01

    Tessellations in the Euclidean plane and regular polygons that tessellate the sphere are reviewed. The regular polygons that can possibly tesellate the sphere are spherical triangles, squares and pentagons.

  20. On the equivalence of different regularization methods

    International Nuclear Information System (INIS)

    Brzezowski, S.

    1985-01-01

    The R-circunflex-operation preceded by the regularization procedure is discussed. Some arguments are given, according to which the results may depend on the method of regularization, introduced in order to avoid divergences in perturbation calculations. 10 refs. (author)