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Sample records for menstruation disturbances

  1. Menstruation disturbances: prevalence, characteristics, and effects on the activities of daily living among adolescent girls from Brazil.

    Science.gov (United States)

    Pitangui, Ana Carolina R; Gomes, Mayra Ruana de A; Lima, Alaine Souza; Schwingel, Paulo Adriano; Albuquerque, Ana Paula dos S; de Araújo, Rodrigo Cappato

    2013-06-01

    To determine the prevalence, characteristics and effects on the activities of daily living of menstruation disturbances among adolescent girls. Descriptive, cross-sectional study. A public school in the city of Petrolina, Brazil. 218 female adolescents of ages between 12 and 17 years. We used a structured questionnaire addressing the socio-demographic and menstrual characteristics of the adolescents. The intensity of menstrual pain and its effect on the activities of daily living were measured using an 11-point numeric rating scale. The mean age of adolescent girls was 13.7 ± 1.5 years. The menstrual cycles of 67% were regular, while 33% were irregular. Dysmenorrhea had a prevalence of 73%, and school absenteeism was observed among 31% of the adolescents. In addition, 66% of the participants considered that dysmenorrhea affected their activities of daily living. Associations were found between the intensity of pain and the variables: school absenteeism; affected activities of daily living; need to use medications; and between affected activities of daily living and school absenteeism (P < .05). Among the menstrual disturbances observed dysmenorrhea stood out due to its high prevalence among adolescents with a negative effect on adolescents' activities of daily living. Early diagnosis and knowledge about menstrual disturbances are essential because in addition to reiterating the importance of implementing health education actions, they also help to choose appropriate treatments, thus minimizing the negative effects of these disturbances on the lives of adolescents. Copyright © 2013 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  2. Menstruation in Ulysses.

    Science.gov (United States)

    Mullin, Katherine

    2008-01-01

    This article investigates James Joyce's fascination with a wide variety of medical texts, sexual folklores, religious beliefs, and persistent superstitions about menstruation. That fascination finds its way into Ulysses, which draws upon a number of intertexts to inform a curiosity about the female body most strikingly articulated by Bloom, Molly, and Gerty MacDowell. These intertexts are not simply imported into the novel but are dismantled and interrogated, as Joyce exposes, rather than endorses, clichés of essential femininity.

  3. Adolescent Experience of Menstruation in Rural Kenya.

    Science.gov (United States)

    Secor-Turner, Molly; Schmitz, Kaitlin; Benson, Kristen

    2016-01-01

    Although menstruation is a universal experience, girls in resource-poor areas face unique challenges related to menstruation management. In Kenya, girls miss nearly 3.5 million learning days per month because of limited access to sanitary products and lack of adequate sanitation. Global priorities to address gender inequality-especially related to education-often do not consider the impact of poverty on gendered experiences, such as menstruation. The aim of the study was to describe the experiences of menstruation from the perspective of adolescent girls living in rural Kenya. Data for this qualitative study were collected through 29 individual interviews with adolescent girls and separate field observations. Descriptive content analysis was used to identify themes reflective of the data from the individual interviews and field notes. Four themes were developed to summarize the data: (a) receiving information about menstruation, (b) experiences of menstruation, (c) menstrual hygiene practices, and (d) social norms and the meaning of menstruation. Findings from this study describe the impact of menstruation on the lives of adolescent girls in rural Kenya. Menstrual hygiene management and its associated challenges may impact girls' academic continuity. Experiences of menstruation also reinforce gender inequality and further marginalize girls in low-income, rural areas of Kenya. Consideration of menstruation is critical to promote health and academic continuity for girls in rural Kenya.

  4. Menstruation.

    Science.gov (United States)

    Henderson, Paula

    This autoinstructional program deals with the study of human develpment with emphasis on the female reproductive system. It is considered as part of a secondary school human anatomy and physiology course. Students should have a previous knowledge of the parts of the female reproductive organs or system. Behavioral objectives are suggested. The…

  5. Menstruation: Symptoms, Management and Attitude of Female ...

    African Journals Online (AJOL)

    and Attitude of Female Nursing Students in Ibadan, Nigeria. Momnéola 0A, and U znqgbn VU. ABSTRACT. This study surveyed 120 student nurses from two schools of nursing in Ibadan, Nigeria to assess the symptoms experienced during menstruation, attitude towards and management of menstruation. The student ...

  6. Menstruation: Symptoms, Management and Attitude of Female ...

    African Journals Online (AJOL)

    This study surveyed 120 student nurses from two schools of nursing in Ibadan, Nigeria to assess the symptoms experienced during menstruation, attitude towards and management of menstruation. The student nurses overall mean age at menarche was 14 years, average duration of menstrual period was five days and ...

  7. Perceptions and Practices on Menstruation Amongst Nigerian ...

    African Journals Online (AJOL)

    ... education; and effectively using the Mass Media as reproductive health education channels are recommended towards improving adolescents\\' perceptions and practices on menstruation. Keywords: Perception and practice, menstruation, Nigerian school-girls. African Journal of Reproductive Health Vol. 12 (1) 2008: pp.

  8. Body appreciation and attitudes toward menstruation.

    Science.gov (United States)

    Chrisler, Joan C; Marván, Maria Luisa; Gorman, Jennifer A; Rossini, Meghan

    2015-01-01

    Menstruation is an important function of the female body, yet it has rarely been included in research on body image. As women's attitudes toward menstruation are so often negative, this study was designed to examine whether women with positive body image would have more positive attitudes toward menstruation. Seventy-two American women, ages 18-45 years, were recruited online to complete the Body Appreciation Scale (Avalos et al., 2005) and the Beliefs about and Attitudes toward Menstruation Scale (Marván et al., 2006) and to answer some questions about their interest in menstrual suppression. Linear regressions showed that higher scores on body appreciation predicted more positive attitudes toward and beliefs about menstruation, but were not related to interest in menstrual suppression. Our findings may be useful in designing interventions to increase women's comfort with their bodies and bodily functions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Talking to Your Child about Menstruation

    Science.gov (United States)

    ... Period at School Do Periods Ever End? What's Vaginal Discharge? Five Things Girls Want to Know About Periods ... My Period? All About Menstruation Pads and Tampons Vaginal Discharge: What's Normal, What's Not Tampons, Pads, and Other ...

  10. The portrayal of the menstruating woman in menstrual product advertisements.

    Science.gov (United States)

    Coutts, L B; Berg, D H

    1993-01-01

    Because menstrual product advertisements act as mediators of a subset of meanings of femininity linked to menstruation, we performed a comparative conceptual analysis of these advertisements to explicate media-constructed realities of contemporary women. We sought to understand the portrayed women's definition of menstruation and their status as menstruating women. Textual and conceptual analyses led us to conclude that the portrayed women, in an attempt to avoid others' discovery of their menstruation, employed a complex menstrual management system, which often includes feminized menstrual products, to act as an antidote to a tainted state of femininity.

  11. Evaluation of Relative Blood Viscosity During Menstruation in ...

    African Journals Online (AJOL)

    Relative blood viscosity, relative plasma viscosity and hematocrit were significantly reduced (P<0.001) during menstruation compared to the values before menstruation. The mean values of relative blood viscosity, relative plasma viscosity and hematocrit were 2.52±0.07, 1.15±0.01 and 0.37±0.004L/L respectively for ...

  12. Cultural aspects and mythologies surrounding menstruation and abnormal uterine bleeding.

    Science.gov (United States)

    Tan, Delfin A; Haththotuwa, Rohana; Fraser, Ian S

    2017-04-01

    The objective of this chapter is to present an overview of how menstruation, a normal bodily function, was and is perceived in various ethnic groups and cultures in the world, from ancient mythology, historical, or traditional practices to contemporary belief systems. Mythical tales about menstruation abound in the legends and prehistory of ancient cultures. These tales characterize menstrual blood variously as sacred, a gift from the gods, or a punishment for sin, but it is almost always magical and powerful. In contrast, most world religions view menstruation, with varying degrees of severity, as a major problem, a sign of impurity and uncleanliness, and therefore, menstruating women are isolated, prohibited from polluting the holy places, and shunned. Many of these myths and cultural misperceptions persist to the present day, reflected in a wide range of negative attitudes toward menstruation, which can have serious and direct implications for reproductive health. In view of the increasingly globalized nature of current clinical practice, it is crucial that health care providers are familiar with existing cultural and social views and attitudes toward the menstrual function. The ultimate goal is to be able to provide women culturally sensitive and medically appropriate therapies for their menstrual disorders. This biocultural approach to menstruation management is desirable in contemporary medical practice. Copyright © 2016. Published by Elsevier Ltd.

  13. Recurrent episcleritis in relation to menstruation: a case report.

    Science.gov (United States)

    Rajoo, Sangeetha Govinda; Gandhewar, Jaishree

    2011-09-01

    To describe a case of recurrent episcleritis associated with a patient's menstrual cycle. A retrospective case review of a 39-year-old woman who presented with a 12-year history of recurrent episcleritis in relation to her menstruation. She was seen during an acute attack and started on a reducing regime of topical steroids for 5 weeks. She was then advised to use it a week before and after menstruation. Examination and investigations revealed episcleritis with a negative systems review. After starting the treatment, she was symptom free when reviewed at 4, 8, 14, and 33 weeks. Now, the patient uses topical steroids only 1 week before menstruation. Literature review revealed no recent case reports and provided insufficient evidence to understand this relationship. We recommend increased awareness and reporting because there is a need for more studies to understand this relationship and to provide evidence for management.

  14. Does Menstruation Explain Gender Gaps in Work Absenteeism?

    Science.gov (United States)

    Herrmann, Mariesa A.; Rockoff, Jonah E.

    2012-01-01

    Ichino and Moretti (2009) find that menstruation may contribute to gender gaps in absenteeism and earnings, based on evidence that absences of young female Italian bank employees follow a 28-day cycle. We find this evidence is not robust to the correction of coding errors or small changes in specification, and we find no evidence of increased…

  15. Cultural interpretation of menstruation in relation to adolescent girls ...

    African Journals Online (AJOL)

    Information derived from researching cultural information on menstruation and other forms of blood flow in adolescent girls in Nigeria can contribute extensively to existing knowledge about the female world in general and on adolescent girls in particular. This will further encourage ongoing advocacy programmes in ...

  16. Menstruation in Rural Igbo Women of South East Nigeria: Attitudes ...

    African Journals Online (AJOL)

    Many cultures hold on to different beliefs and retain community-defined restrictions for menstruating women. The Igbo society of southeast Nigeria is rich in culture, myths and superstitions but, surprisingly no documentation exists on menstrual beliefs and practices among the population. This questionnaire-based cross ...

  17. Menstruation in an unusual place: A case of thoracic endometriosis ...

    African Journals Online (AJOL)

    While pelvic endometriosis is relatively common, thoracic menstruation is rare. A report of what is believed to be the first case of thoracic endometriosis in Uganda is given. A 34 year old female was complaining of on and off chest pain mainly on the right side. Clinically she had signs of pleural effusion and 500 mls of altered ...

  18. Evaluation of Relative Blood Viscosity During Menstruation in ...

    African Journals Online (AJOL)

    USER

    statistical analysis (paired t-Test; correlation and regression). Blood samples were collected during two phases of the menstrual cycle – the premenstrual and the mid menstrual phase. Results show variations in the studied parameters before and during menstruation. Relative blood viscosity, relative plasma viscosity.

  19. Teaching Taboo Topics: Menstruation, Menopause, and the Psychology of Women

    Science.gov (United States)

    Chrisler, Joan C.

    2013-01-01

    The purpose of this article is (a) to consider reasons why women's reproductive processes receive so little attention in psychology courses and (b) to make an argument for why more attention is needed. Menstruation, menopause, and other reproductive events are important to the psychology of women. Reproductive processes make possible a social role…

  20. Menstruation: Experiences of Adolescent Slum Dwelling Girls of ...

    African Journals Online (AJOL)

    Background: Adolescence is defi ned as the teenage period of life, involving major biological changes and psycho-social development. In adolescence, the girls fi rst experience menstruation and good hygiene is essential during this period. Menstrual hygiene is an issue that is insuffi ciently acknowledged and has not ...

  1. Menstruation: Experiences of Adolescent Slum Dwelling Girls of ...

    African Journals Online (AJOL)

    Mubeen

    Background: Adolescence is defined as the teenage period of life, involving major biological changes and psycho-social development. In adolescence, the girls first experience menstruation and good hygiene is essential during this period. Menstrual hygiene is an issue that is insuffi ciently acknowledged and has not ...

  2. [Menstruation disorders more frequent in women with a history of sexual abuse

    NARCIS (Netherlands)

    Vink, C.W.; Labots-Vogelesang, S.M.; Lagro-Janssen, A.L.M.

    2006-01-01

    OBJECTIVE: To determine the relationship between menstruation disorders and prior sexual abuse. DESIGN: Questionnaire investigation. METHOD: A questionnaire was developed consisting of 50 questions about menstruation disorders, premenstrual syndrome and sexual abuse. The questionnaire was mailed to

  3. A Case for Critical Literacy Analysis of the Advertising Texts of Menstruation: Responding to Missed Opportunities

    Science.gov (United States)

    Agnew, Shire; Sandretto, Susan

    2016-01-01

    When Agnew found the same, largely negative, dominant discourses of menstruation present in classroom lessons that researchers have been identifying for over 30 years, she sought different approaches to menstruation education. In this article the authors highlight the power of the media to (re)construct dominant discourses of menstruation and the…

  4. The increase in leucocyte count during menstruation is a function of ...

    African Journals Online (AJOL)

    Menstruation is an endocrine mediated physiologic cyclical bleeding per vagina in a non-pregnant woman of the reproductive age group. Blood is a good culture medium for bacteria and as such, menstruation can affect leucocytes count. This study is aimed at evaluating leucocytes count during menstruation. Fifty-eight ...

  5. Mechanism of normal menstruation and abnormality associated with menorrhagia

    Directory of Open Access Journals (Sweden)

    Jeanne A. Pawitan

    2001-06-01

    Full Text Available Normal menstruation involves endometrial tissue breakdown and bleeding, followed by hemostasis and repair. Abnormality of this process at any stage may result in changes in the quantity of menstrual blood loss. When menstrual blood loss is greater than 80 ml, it is called menorrhagia. This review discuss the mechanism of normal menstruation, and factors associated with menorrhagia. Those factors are the endometrial bleeding associated factor (ebaf, the role of various cells (migratory leucocytes, macrophages, and mast cells, the role of various substances (lysosomal enzymes, prostaglandins, endothelins, growth factors and its receptors, impairment of fibrinolysis and hemostatic proces, and changes in endometrial blood flow. (Med J Indones 2001; 10: 121-6Keywords : ebaf, prostaglandin, endothelin, fibrinolysis

  6. Queer periods: attitudes toward and experiences with menstruation in the masculine of centre and transgender community.

    Science.gov (United States)

    Chrisler, Joan C; Gorman, Jennifer A; Manion, Jen; Murgo, Michael; Barney, Angela; Adams-Clark, Alexis; Newton, Jessica R; McGrath, Meaghan

    2016-11-01

    Menstruation has long been viewed as an important aspect of women's health. However, scholars and healthcare providers have only recently begun to recognise that transgender men and people with masculine gender identities also menstruate, thus little is known about their attitudes toward and experiences with menstruation. A sample of masculine of centre and transgender individuals with a mean age of 30 years was recruited online to complete measures of attitudes toward menstruation and menstrual suppression and to answer exploratory questions about their experiences managing menstruation. Participants reported mixed attitudes toward menstruation, but generally positive attitudes toward menstrual suppression. Many participants said that they try to avoid public restrooms during menstruation because of practical and psychological concerns. Implications of our findings for the transgender health are discussed.

  7. Feasibility and effectiveness of unintended pregnancy prevention with low-dose mifepristone combined with misoprostol before expected menstruation.

    Science.gov (United States)

    Li, Cui-Lan; Chen, Dun-Jin; Deng, Yi-Fan; Song, Li-Ping; Mo, Xue-Tang; Liu, Kai-Jie

    2015-12-01

    What is the efficacy of maintaining or restoring non-pregnant status with low-dose mifepristone combined with misoprostol administered before expected menstruation? Low-dose mifepristone and misoprostol administered at the time of expected menstruation was effective and safe in maintaining or restoring non-pregnant status, with no obvious menstrual disturbance. Menstrual regulation involves the medical or mechanical stimulation of uterine sloughing in women with up to 2-3 weeks of menstrual delay. Low-dose mifepristone plus misoprostol is efficacious for termination of ultra-early pregnancy (≤ 35 days of amenorrhoea) with no obvious menstrual disturbance. A total of 678 women fulfilled all criteria and were recruited. Seventeen women dropped out after deciding to remain pregnant and 11 others were lost to follow-up. Thus, data from 650 women who completed the procedure were included in analyses. Participants were enrolled at any time during their menstrual cycle and administered medication 1 day before expected menstruation. The end of the study was defined on a per-patient basis as the date of completion of the post-treatment menstrual cycle. The primary outcome was the efficacy of abortion induction (for pregnant women) or menstrual regulation (for non-pregnant women). Women with regular menstrual cycles (25-35 days) were voluntarily recruited for this study between February 2012 and December 2014. Serum β-hCG was measured before mifepristone intake. Mifepristone (50 mg) was administered orally 1 day before expected menstruation and 200 µg misoprostol was administered orally on the day of expected menstruation. Efficacy, disturbance in bleeding patterns in the treatment and post-treatment cycles, satisfaction with the treatment, and subsequent contraception preference were analysed. Retrospective analysis of serum β-hCG levels at admission indicated that 23.3% (158/678) of the women were pregnant. The success rate for pregnancy termination was 98.6% (136

  8. Quantity and quality of retrograde menstruation: a case control study

    Directory of Open Access Journals (Sweden)

    Drijkoningen Maria

    2009-01-01

    Full Text Available Abstract Background The purpose of this study was to test the hypothesis that menstruation is associated with a higher concentration of endometrial cells in peritoneal fluid(PF and with increased white and red blood cell concentration in PF when compared to nonmenstrual phases of the cycle. Methods PF was obtained at laparoscopy from 107 women with endometriosis (n = 59 and controls with a normal pelvis (n = 48 during the luteal (n = 46, follicular (n = 38 or menstrual (n = 23 phase of the cycle. Endometriosis was classified according to the classification of the American Society for Reproductive Medicine (rAFS into minimal (n = 25, mild(n = 20, moderate(n = 6 and severe(n = 8 disease. Cell counts (leucocytes, erythrocytes, thrombocytes were determined on a cell counter. In a subset of 32 patients (13 controls and 19 women with endometriosis, PF was fixed, processed and thinlayers were prepared and stained with Papanicolaou method and with immunocytochemistry using monoclonal antibodies against cytokeratin 7(CK 7, CK 8/18, Ber-Ep4, vimentin, calretinin and CD68. Ber-Ep4 is a marker for cells with epithelial origin (in some cases for mesothelial cells as well. CD68 is specific for cells from monocyte/macrophage lineage; CK7 and CK8/18 are markers for both endometrial epithelial and mesothelial cells, whereas calretinin and vimentin are markers for both endometrial stromal and mesothelial cells. Results In comparison with the nonmenstrual phase of the cycle, analysis of PF during menstruation showed an increased concentration of leucocytes (3.3 × 109/L vs 0.8 × 109/L, P = 0.03, erythrocytes (0.3 × 1012/L vs 0.02 × 1012/L, P = 0.006, hematocrit (0.03 L/L vs 0.003 L/L, P = 0.01 and hemoglobin (0.8 g/dL vs 0.1 g/dL, P = 0.01. Mesothelial cells stained positively with CK7, CK8/18, vimentin, and calretinin. Cells positive for Ber-Ep4 were not observed, except in 2 patients with endometriosis investigated during menses. In all patients 50-98% of

  9. Ambivalent sexism, attitudes towards menstruation and menstrual cycle-related symptoms.

    Science.gov (United States)

    Marván, Ma Luisa; Vázquez-Toboada, Rocío; Chrisler, Joan C

    2014-08-01

    The objective of the present study was to investigate the relationship between ambivalent sexism and beliefs and attitudes towards menstruation, and, in turn, to study the influence of these variables on menstrual cycle-related symptoms. One hundred and six Mexican women completed the Ambivalent Sexism Inventory, the Beliefs about and Attitudes toward Menstruation Questionnaire and the Menstrual Distress Questionnaire. The higher scores on benevolent sexism were associated with the most positive attitudes towards menstruation and also with the belief that a menstruating woman should or should not do some activities and that menstruation keeps women from their daily activities. The higher scores on hostile sexism were associated with rejection of menstruation as well as with feelings of embarrassment about it. Beliefs about and attitudes towards menstruation predicted menstrual cycle-related symptoms related to negative affect, impaired concentration and behavioural changes, but did not predict somatic symptoms. These results will be useful to health professionals and advocates who want to change the negative expectations and stereotypes of premenstrual and menstrual women and reduce the sexism and negative attitudes towards women that are evident in Mexican culture. © 2013 International Union of Psychological Science.

  10. Menstruation experiences of South African women belonging to the ama-Xhosa ethnic group.

    Science.gov (United States)

    Padmanabhanunni, Anita; Jaffer, Labeeqah; Steenkamp, Jeanette

    2017-09-15

    A growing body of research has emphasised the salience of cultural beliefs and traditional practices to women's experiences of menstruation. Relatively less research has, however, been undertaken in South Africa. This study explored the experience of menstruation among women from the ama-Xhosa ethnic group, one of the largest ethnic groups in the country. Among the ama-Xhosa, there are distinct cultural practices associated with menstruation, including the female rite of passage (intonjane) and virginity testing (inkciyo). However, few studies have explored the experience of menstruation for women from this cultural group. This study involved the synthesis of data from individual interviews and focus group discussions conducted among a sample of ama-Xhosa women. The data were analysed using thematic analysis. Distinctive findings included women's participation in traditional cultural practices of intonjane and inkciyo and the presence of cultural taboos associated with menstruation. Women's narratives revealed strong ambivalence regarding these practices. On the one hand, they wanted to adhere to traditional practices but experienced these customs as evoking discomfort and shame. The study confirmed the prevalence of negative constructions of menstruation. Positive appraisals of menstruation as evoking joy and happiness were also encountered.

  11. 'We do not know': a qualitative study exploring boys perceptions of menstruation in India.

    Science.gov (United States)

    Mason, Linda; Sivakami, Muthusamy; Thakur, Harshad; Kakade, Narendra; Beauman, Ashley; Alexander, Kelly T; van Eijke, Anna Maria; Laserson, Kayla F; Thakkar, Mamita B; Phillips-Howard, Penelope A

    2017-12-08

    In low-middle income countries and other areas of poverty, menstrual hygiene management (MHM) can be problematic for women and girls. Issues include lack of knowledge about menstruation and MHM, and stigma around menstruation, also access to affordable and absorbent materials; privacy to change; adequate washing, cleaning and drying facilities; as well as appropriate and accessible disposal facilities. In order to effect change and tackle these issues, particularly in patriarchal societies, males may need to become advocates for MHM alongside women. However, little is known about their knowledge and attitudes towards menstruation, which may need addressing before they can assist in acting as advocates for change. The present study was undertaken to explore knowledge and attitudes about menstruation among adolescent boys across India, in order to gauge their potential to support their 'sisters'. The study was undertaken across three states in India, chosen a priori to represent the cultural and socio-economic diversity. Qualitative data using focus group discussions with 85 boys aged 13-17 years, from 8 schools, was gathered. Data were analysed using thematic analysis. The results were organised into three main themes, reflecting the key research questions: boys' knowledge of menstruation, source of knowledge, and attitudes towards menstruation and menstruating girls. Knowledge comprised three aspects; biological function which were generally poorly understood; cultural rites which were recognized by all; and girls' behaviour and demeanour, which were noted to be withdrawn. Some boys learnt about puberty and menstruation as part of the curriculum but had concerns this was not in-depth, or was missed out altogether. Most gathered knowledge from informal sources, from overhearing conversations or observing cultural rituals. Few boys openly displayed a negative attitude, although a minority voiced the idea that menstruation is a 'disease'. Boys were mostly sympathetic

  12. Living donor hepatectomy in female donors with ongoing menstruation: Safety and ethical issues

    Directory of Open Access Journals (Sweden)

    Horng-Ren Yang

    2017-01-01

    Conclusions: Our study shows safety of right lobe living donation in female donors with ongoing menstruation with no increased risk of intraoperative excessive bleeding and postoperative physiological impact on their general health.

  13. Disturbing forest disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Volney, W.J.A.; Hirsch, K.G. [Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB (Canada)

    2005-10-01

    This paper described the role that disturbances play in maintaining the ecological integrity of Canadian boreal forests. Potential adaptation options to address the challenges that these disturbances present were also examined. Many forest ecosystems need fire for regeneration, while other forests rely on a cool, wet disintegration process driven by insects and commensal fungi feeding on trees to effect renewal. While there are characteristic natural, temporal and spatial patterns to these disturbances, recent work has demonstrated that the disturbances are being perturbed by climatic change that has been compounded by anthropogenic disturbances in forests. Fire influences species composition and age structure, regulates forest insects and diseases, affects nutrient cycling and energy fluxes, and maintains the productivity of different habitats. Longer fire seasons as a result of climatic change will lead to higher intensity fires that may more easily evade initial attacks and become problematic. Fire regimes elevated beyond the range of natural variation will have a dramatic effect on the regional distribution and functioning of forest ecosystems and pose a threat to the safety and prosperity of people. While it was acknowledged that if insect outbreaks were to be controlled on the entire forest estate, the productivity represented by dead wood would be lost, it was suggested that insects such as the forest tent caterpillar and the spruce bud worm may also pose a greater threat as the climate gets warmer and drier. Together with fungal associates, saproxylic arthropods are active in nutrient cycling and ultimately determine the fertility of forest sites. It was suggested that the production of an age class structure and forest mosaic would render the forest landscape less vulnerable to the more negative aspects of climate change on vegetation response. It was concluded that novel management design paradigms are needed to successfully reduce the risk from threats

  14. Menstrual-Cycle and Menstruation Disorders in Episodic vs Chronic Migraine: An Exploratory Study.

    Science.gov (United States)

    Spierings, Egilius L H; Padamsee, Aliya

    2015-07-01

    Migraine is a chronic condition of recurring moderate-to-severe headaches that affects an estimated 6% of men and 18% of women. The highest prevalence is in those 18-49 years of age, generally when women menstruate. It is divided into episodic and chronic migraine depending on the total number of headache days per month being 14 or less or 15 or more, respectively. Migraine has been associated with menorrhagia, dysmenorrhea, and endometriosis, the latter particularly in chronic migraine. We conducted a questionnaire survey of 96 women with migraine, 18-45 years old, to determine the occurrence of the menstrual-cycle disorders, oligomenorrhea, polymenorrhea, and irregular cycle, and the menstruation disorders, dysmenorrhea and menorrhagia, in episodic vs chronic migraine. The prevalence of menstrual-cycle disorders in general (41.2 vs 22.2%) and dysmenorrhea (51.0 vs 28.9%) was statistically significantly higher in the women with chronic migraine than in those with episodic migraine (P ≤ 0.05) (not corrected for multiple comparisons). Whether the migraine was menstruation sensitive, that is, the headaches consistently occurred or worsened with menstruation, did not impact the prevalence of menstrual disorders. We conclude that chronic migraine is possibly more often than episodic migraine associated with menstrual-cycle disorders in general and dysmenorrhea, without impact on menstruation sensitivity of the headaches. Wiley Periodicals, Inc.

  15. Relationship between Female University Students’ Knowledge on Menstruation and Their Menstrual Hygiene Practices: A Study in Tamale, Ghana

    Directory of Open Access Journals (Sweden)

    Evans Paul Kwame Ameade

    2016-01-01

    Full Text Available Positive perception about menstruation and good menstrual hygiene practice safeguards the health of postpubescent females by reducing their vulnerability to reproductive and urinary tract infections. Using a questionnaire, a cross-sectional study involving 293 randomly selected female undergraduate students in northern Ghana assessed the relationship between knowledge on menstruation and the practice of safe menstrual hygiene. Data collected was analyzed using GraphPad 5.01. This study found that although majority of respondents (73.4% were aware of menstruation before menarche, most of them experienced fear and panic when it occurred. Mothers were the first to be informed when menstruation occurred, although teachers first provided them knowledge on menstruation. Respondents’ knowledge on menstruation was average (57.3% but their menstrual hygiene practice was good (80.2%. Age (p=0.005 and course of study (p=0.0008 significantly influenced respondents’ knowledge on menstruation with older students as well as the medical and midwifery students being most knowledgeable. Muslim rather than Christian female students practiced better menstrual hygiene (p=0.0001. Average knowledge score on menstruation indicated a deficit of knowledge on the anatomy and physiology of the female reproductive system. Increasing knowledge on menstruation had a positive and significant effect on practice of good menstrual hygiene.

  16. A study on the status of and factors in irregular menstruation in university students

    Directory of Open Access Journals (Sweden)

    Tuba Ucar

    2015-06-01

    Methods: The present descriptive study was conducted at Health College of Inonu University between November 15 and December 01, 2012. The population was comprised of a total of 678 female students who studied Midwifery (n=212 and Nursing (n=466. No specific sample was chosen; therefore, all the participants were included within the scope of the study. However, the sample was comprised of a total of 365 students who volunteered to participate in the study. The data were obtained through the and ldquo;Personal Information Form and rdquo; and analyzed via such statistics as Pearson's Chi-Squared test, Fisher's exact test and t-test for independent groups. Results: The mean age of the participants was 20.28+/-1.99. While 46% of them studied midwifery, the remaining 54% studied nursing. The mean menarche age was 13.45+/-1.55 whereas the mean menstruation length was 5.61+/-1.88. The prevalence of irregular menstruation in the students was 23.8%. The study could not yield a correlation between irregular menstruation and age, presence of chronic disease and average daily sleep time with irregular menstruation (p>0.05. Those students who do not exercise regularly, had psychiatric disorders, regular drug users, in users of oral contraceptives, smoked and had higher Body-Mass Indices were more likely to suffer from irregular menstruation (p<0.05. Conclusions: The study concluded that nearly one-fourth of the students had irregular menstruation. The finding is promising inthat all these risk factors (obesity, smoking, sedentary living, medication and oral contraceptive use are avoidablewith changes in behaviors, for which healthcare professionals are significantly responsible [TAF Prev Med Bull 2015; 14(3.000: 215-221

  17. [Vaginal bacteriology in women with use of sanitary towels and tampons during menstruation].

    Science.gov (United States)

    Unzeitig, V; Bucek, R; Al Awad, H

    2007-12-01

    Clinical study of peri-menstrual changes of vaginal environment in healthy fertile women after long-term use of sanitary towels (group A) or vaginal tampons (group B). Prospective study. SEAT OF SITE: Centre of Outpatient Gynaecology Brno, Dept. of Obstetrics and Gynaecology, Masaryk Univesrity Brno. The group consisted of 100 females with regular menstrual cycle without clinical and microbiological signs of vaginal inflammation or dysmicrobia for three months. In the perimenstrual period samples were taken three times from the ventral vaginal arch and sent for culture examination. A selected group of the females was also subject to culture examination of samples taken from the vulva 0.5 cm under the posterior comisure. Occurrence of ten most common bacteria and yeasts before beginning of menstruation was comparable in both groups. In the course of menstrual bleeding reproduction of bacteria in group B was lower and the vaginal environment return to normal after menstruation end was quicker in the same group. Significant differences between the two groups also included a higher occurrence of peptostreptococci, E. coli and enterococci during and after menstruation in group A women. Regular use of vaginal tampons during menstruation does not represent increased risk of disruption of the vaginal environment, effusions or recurring sexually transmitted infections.

  18. Premenarcheal Mexican Girls' and Their Teachers' Perceptions of Preparation Students Receive about Menstruation at School.

    Science.gov (United States)

    Marvan, Luisa; Bejarano, Janett

    2005-01-01

    This survey explored how fifth-grade Mexican premenarcheal girls (N = 80) and their teachers (N = 16) view the preparation students receive about menstruation at school. The most discussed topics in class included hygiene and body functions. The main discrepancies between girls and teachers were as follows: (a) more teachers than girls reported…

  19. Knowledge and awareness regarding menstruation and HIV/AIDS among schoolgoing adolescent girls.

    Science.gov (United States)

    Jain, Rakhi; Anand, Puneet; Dhyani, Anuj; Bansal, Deshant

    2017-01-01

    Menstruation in our country is associated with various myths and restrictions leading to lack of awareness among adolescent girls. Insufficient menstrual hygiene practices are the cause of stress associated with menstruation and reproductive tract infections. Sexually transmitted infections and HIV/AIDS are not openly discussed in our society making adolescents vulnerable to them. To assess the knowledge of school going adolescent girls regarding menstrual hygiene and HIV/AIDS. Girls studying in class 8 th -12 th standard and who have attained menarche were included in the study. A predesigned questionnaire, which consisted of questions related to menstrual awareness and knowledge about HIV/AIDS was used for data collection. Data was analysed using SPSS software and results were interpreted into percentages. 282 girls took part in the study. Mean age of girls was 14.70 ± 1.5 years. Median age of girls was 15 years. Knowledge regarding menstrual hygiene and HIV/AIDS was found to be only satisfactory leaving a scope of improvement. Mother was the main source of information regarding both menstruation and HIV/AIDS. A comprehensive health education programme involving mothers is required to remove various misconceptions and taboos associated with menstruation and make it a pleasant experience for adolescent girls. Information, education and awareness programmes need to be strengthened to spread awareness regarding HIV/AIDS.

  20. How Menstruation Is Shaping Girls' Education in Rural Nepal

    Science.gov (United States)

    Basyal, Samrat

    2016-01-01

    With voices for women's education coming from around the globe, it is a real setback when girls are unable to attend schools during their menstruation or periods, a process they encounter every month. The absence of Nepalese rural female students from schools during their periods does not only have the biological aspect to it but incorporates a…

  1. Granulocytes and vascularization regulate uterine bleeding and tissue remodeling in a mouse menstruation model.

    Directory of Open Access Journals (Sweden)

    Astrid Menning

    Full Text Available Menstruation-associated disorders negatively interfere with the quality of life of many women. However, mechanisms underlying pathogenesis of menstrual disorders remain poorly investigated up to date. Among others, this is based on a lack of appropriate pre-clinical animal models. We here employ a mouse menstruation model induced by priming mice with gonadal hormones and application of a physical stimulus into the uterus followed by progesterone removal. As in women, these events are accompanied by menstrual-like bleeding and tissue remodeling processes, i.e. disintegration of decidualized endometrium, as well as subsequent repair. We demonstrate that the onset of bleeding coincides with strong upregulation of inflammatory mediators and massive granulocyte influx into the uterus. Uterine granulocytes play a central role in regulating local tissue remodeling since depletion of these cells results in dysregulated expression of matrix modifying enzymes. As described here for the first time, uterine blood loss can be quantified by help of tampon-like cotton pads. Using this novel technique, we reveal that blood loss is strongly reduced upon inhibition of endometrial vascularization and thus, is a key regulator of menstrual bleeding. Taken together, we here identify angiogenesis and infiltrating granulocytes as critical determinants of uterine bleeding and tissue remodeling in a mouse menstruation model. Importantly, our study provides a technical and scientific basis allowing quantification of uterine blood loss in mice and thus, assessment of therapeutic intervention, proving great potential for future use in basic research and drug discovery.

  2. 'Gushing Out Blood': Defloration and Menstruation in Memoirs of a Woman of Pleasure.

    Science.gov (United States)

    Read, Sara

    2016-12-26

    John Cleland's 1740s pornographic novel, Memoirs of a Woman of Pleasure repeatedly depicts and eroticises the act of defloration. As such it is a revealing illustration of what Ivan Bloch termed the 'defloration mania' of the eighteenth century. This article maps narrative events on to contemporary medical depictions of first intercourse to show the ways that the theories and ideas presented in medical and pseudo-medical texts transferred into erotic fiction and demonstrates how in some instances the bloody defloration scenes can be read as being sex during menstruation, an act which was culturally forbidden at this time.

  3. Menstruation in girls and adolescents: using the menstrual cycle as a vital sign.

    Science.gov (United States)

    Diaz, Angela; Laufer, Marc R; Breech, Lesley L

    2006-11-01

    Young patients and their parents often are unsure about what represents normal menstrual patterns, and clinicians also may be unsure about normal ranges for menstrual cycle length and amount and duration of flow through adolescence. It is important to be able to educate young patients and their parents regarding what to expect of a first period and about the range for normal cycle length of subsequent menses. It is equally important for clinicians to have an understanding of bleeding patterns in girls and adolescents, the ability to differentiate between normal and abnormal menstruation, and the skill to know how to evaluate young patients' conditions appropriately. Using the menstrual cycle as an additional vital sign adds a powerful tool to the assessment of normal development and the exclusion of pathological conditions.

  4. [Experimental testing of Pflüger's reflex hypothesis of menstruation in late 19th century].

    Science.gov (United States)

    Simmer, H H

    1980-07-01

    Pflüger's hypothesis of a nerve reflex as the cause of menstruation published in 1865 and accepted by many, nonetheless did not lead to experimental investigations for 25 years. According to this hypothesis the nerve reflex starts in the ovary by an increase of the intraovarian pressure by the growing follicles. In 1884 Adolph Kehrer proposed a program to test the nerve reflex, but only in 1890, Cohnstein artificially increased the intraovarian pressure in women by bimanual compression from the outside and the vagina. His results were not convincing. Six years later, Strassmann injected fluids into ovaries of animals and obtained changes in the uterus resembling those of oestrus. His results seemed to verify a prognosis derived from Pflüger's hypothesis. Thus, after a long interval, that hypothesis had become a paradigma. Though reasons can be given for the delay, it is little understood, why experimental testing started so late.

  5. The forecasting of menstruation based on a state-space modeling of basal body temperature time series.

    Science.gov (United States)

    Fukaya, Keiichi; Kawamori, Ai; Osada, Yutaka; Kitazawa, Masumi; Ishiguro, Makio

    2017-09-20

    Women's basal body temperature (BBT) shows a periodic pattern that associates with menstrual cycle. Although this fact suggests a possibility that daily BBT time series can be useful for estimating the underlying phase state as well as for predicting the length of current menstrual cycle, little attention has been paid to model BBT time series. In this study, we propose a state-space model that involves the menstrual phase as a latent state variable to explain the daily fluctuation of BBT and the menstruation cycle length. Conditional distributions of the phase are obtained by using sequential Bayesian filtering techniques. A predictive distribution of the next menstruation day can be derived based on this conditional distribution and the model, leading to a novel statistical framework that provides a sequentially updated prediction for upcoming menstruation day. We applied this framework to a real data set of women's BBT and menstruation days and compared prediction accuracy of the proposed method with that of previous methods, showing that the proposed method generally provides a better prediction. Because BBT can be obtained with relatively small cost and effort, the proposed method can be useful for women's health management. Potential extensions of this framework as the basis of modeling and predicting events that are associated with the menstrual cycles are discussed. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  6. A cross-sectional study of the beliefs and attitudes towards menstruation of Chinese undergraduate males and females in Hong Kong.

    Science.gov (United States)

    Wong, Wing Chi; Li, Mei Kuen; Chan, Wai Ying Veronica; Choi, Yuen Yu; Fong, Chi Hung Sandra; Lam, Ka Wah Kara; Sham, Wun Chi; So, Ping Ping; Wong, Kit; Yeung, Kuen Ha; Yeung, Tsz Yan

    2013-12-01

    To explore the beliefs and attitudes towards menstruation of Chinese undergraduates in Hong Kong and to compare those of (1) male and female undergraduates with those of (2) undergraduates studying health-related vs. nonhealth-related programmes. Menstruation is typically viewed as a forbidden topic or a troublesome experience. These negative beliefs and attitudes result from existing myths and taboos associated with cultural factors and health education levels. A cross-sectional survey was conducted in all universities in Hong Kong. Undergraduates were invited through convenience sampling to complete a questionnaire assessing their attitudes and beliefs towards menstruation. A questionnaire on 'beliefs about and attitudes towards menstruation' was adopted. Questionnaires were self-administered by the respondents. A total of 450 questionnaires were distributed, and a response rate of 96.6% was obtained; 416 completed questionnaires were collected and analysed. Many Chinese undergraduates agreed that menstruation is annoying, causes disability, involves prescription and proscription and is not pleasant. When comparing the beliefs and attitudes towards menstruation of Chinese male undergraduates with those of female undergraduates, females tended to disagree that menstruation should be maintained secret, but tended to agree that it was annoying. When comparing the beliefs and attitudes towards menstruation of Chinese undergraduates studying health-related programmes with those under nonhealth-related programmes, the latter group exhibited a higher level of belief in prescription and proscription for menstruation than the former group. Chinese undergraduates in Hong Kong were influenced by the traditional Chinese culture and social environment, resulting in negative attitudes towards menstruation. This study recommends that sex education, especially reproductive health education, be extended to tertiary education. This study provides relevant information on planning

  7. Ovarian and uterine maturity assessed by pelvic ultrasound scanning in adolescent girls with anorexia nervosa at the start of treatment – correlation with the history of menstruation

    Directory of Open Access Journals (Sweden)

    Gabriela Jagielska

    2010-12-01

    Full Text Available In females, absence of at least three consecutive menstrual cycles when otherwise expected to occur or cessation of pubescence (primary and secondary amenorrhea are the symptoms of anorexia nervosa, secondary to hypogonadotropic hypogonadism. Disturbances in sexual organs are seen in inappropriate for age pelvic ultrasound scanning. The aim of the study was to determine the ovarian and uterine maturity at the onset of anorexia nervosa (AN in adolescence, using pelvic ultrasound scanning, and their relations to clinical factors describing the course of AN. Material and method: The group consisted of 38 adolescent girls with anorexia nervosa diagnosed acc. to ICD-10 criteria – mean age 14.3±2.1 years, mean age at the beginning of AN symptoms 13±2.3 years, mean BMI 14±1.6 kg/m2. On initial assessment, all girls underwent physical examination, clinical interview concerning AN symptoms and pelvic ultrasound scanning. Results: Sixteen patients (42% had primary amenorrhea. In 32% of patients cessation of menses occurred before a significant decrease in weight. Ovarian and uterine volumes significantly below the expected were found in 11 and 15 patients with secondary amenorrhea, respectively. The varian and uterine maturity was related to shorter duration of amenorrhea and longer duration of adequate menstruation before the onset of AN. There were no BMI differences between the groups with more and less mature ultrasound picture.

  8. Treatment of menorrhagia during menstruation: randomised controlled trial of ethamsylate, mefenamic acid, and tranexamic acid.

    Science.gov (United States)

    Bonnar, J.; Sheppard, B. L.

    1996-01-01

    OBJECTIVE: To compare the efficacy and acceptability of ethamsylate, mefenamic acid, and tranexamic acid for treating menorrhagia. DESIGN: Randomised controlled trial. SETTING: A university department of obstetrics and gynaecology. SUBJECTS: 76 women with dysfunctional uterine bleeding. INTERVENTIONS: Treatment for five days from day 1 of menses during three consecutive menstrual periods. 27 patients were randomised to take ethamsylate 500 mg six hourly, 23 patients to take mefenamic acid 500 mg eight hourly, and 26 patients to take tranexamic acid 1 g six hourly. MAIN OUTCOMES MEASURES: Menstrual loss measured by the alkaline haematin method in three control menstrual periods and three menstrual periods during treatment; duration of bleeding; patient's estimation of blood loss; sanitary towel usage; the occurrence of dysmenorrhoea; and unwanted events. RESULTS: Ethamsylate did not reduce mean menstrual blood loss whereas mefenamic acid reduced blood loss by 20% (mean blood loss 186 ml before treatment, 148 ml during treatment) and tranexamic acid reduced blood loss by 54% (mean blood loss 164 ml before treatment, 75 ml during treatment). Sanitary towel usage was significantly reduced in patients treated with mefenamic acid and tranexamic acid. CONCLUSIONS: Tranexamic acid given during menstruation is a safe and highly effective treatment for excessive bleeding. Patients with dysfunctional uterine bleeding should be offered medical treatment with tranexamic acid before a decision is made about surgery. PMID:8806245

  9. Water, Sanitation and Hygiene Conditions in Kenyan Rural Schools: Are Schools Meeting the Needs of Menstruating Girls?

    Directory of Open Access Journals (Sweden)

    Kelly T. Alexander

    2014-05-01

    Full Text Available Water, sanitation and hygiene (WASH programs in African schools have received increased attention, particularly around the potential impact of poor menstrual hygiene management (MHM on equity for girls’ education. This study was conducted prior to a menstrual feasibility study in rural Kenya, to examine current WASH in primary schools and the resources available for menstruating schoolgirls. Cross-sectional surveys were performed in 62 primary schools during unannounced visits. Of these, 60% had handwashing water, 13% had washing water in latrines for menstruating girls, and 2% had soap. Latrines were structurally sound and 16% were clean. Most schools (84% had separate latrines for girls, but the majority (77% had no lock. Non-governmental organizations (NGOs supported WASH in 76% of schools. Schools receiving WASH interventions were more likely to have: cleaner latrines (Risk Ratio (RR 1.5; 95% Confidence Intervals [CI] 1.0, 2.1, handwashing facilities (RR 1.6, CI 1.1, 2.5, handwashing water (RR 2.7; CI 1.4, 5.2, and water in girls’ latrines (RR 4.0; CI 1.4, 11.6. Schools continue to lack essential WASH facilities for menstruating girls. While external support for school WASH interventions improved MHM quality, the impact of these contributions remains insufficient. Further support is required to meet international recommendations for healthy, gender-equitable schools.

  10. Evidence about extending the duration of oral contraceptive use to suppress menstruation.

    Science.gov (United States)

    Hitchcock, Christine L; Prior, Jerilynn C

    2004-01-01

    For many years, individual women and doctors have experimented with extending the duration of active oral contraceptive (OC) pills between pill-free intervals (long OC) to control menstruation. The U.S. approval of an OC with 84 active days and 7 pill-free days in 2003 has attracted considerable media attention. In this review we consider the published evidence on the effectiveness, side effects, and risks of menstrual suppression with long OC. We performed a systematic review of published literature on long OC, up to April 2003. Ten papers were located; two were randomized trials comparing long OC to standard OC; the remaining studies were single-group observational studies. Women on long OC schedules had fewer days of scheduled bleeding during days without pills but more days of unscheduled bleeding and spotting than those on standard OC. These problems were worse for women new to OC and diminished over time. Women on long OC were more likely to discontinue due to poor control of bleeding; women on standard OC were more likely to stop because of problems with headaches. Women on long OC and standard OC both showed increases in physiological factors related to clotting, with a nonsignificant tendency for those on long OC to be more affected. No studies considered the effects of long OC on breast tissue, breast density, endometrial safety, or adolescent maturation and reproductive development. No systematic data were available on the return to reproductive function and fertility after taking long OC. There were no placebo-controlled trials and no information on how long OC compares to normal, unmedicated menstrual cycles. Therefore we believe scientific evidence for safety of long OC use is presently lacking.

  11. Knowledge, Practices, and Restrictions Related to Menstruation among Young Women from Low Socioeconomic Community in Mumbai, India.

    Science.gov (United States)

    Thakur, Harshad; Aronsson, Annette; Bansode, Seema; Stalsby Lundborg, Cecilia; Dalvie, Suchitra; Faxelid, Elisabeth

    2014-01-01

    The main objective was to assess knowledge, practices, and restrictions faced by young women regarding their menstrual hygiene. The views of adult women having young daughters were also included and both views were compared. In addition, the factors influencing the menstrual hygiene practices were also studied. The study was carried out during 2008 in Mumbai, India. The mixed methods approach was followed for the data collection. Both qualitative and quantitative methods were used to collect the data. For quantitative survey, totally 192 respondents (96 adult and 96 younger women) were selected. While young women were asked about questions related to their menstruation, adult women were asked questions to find out how much they know about menstrual history of their daughters. The qualitative data helped to supplement the findings from the quantitative survey and to study the factors affecting menstrual practices in young women. The mean age at menarche reported was 13.4 years and 30-40% of young girls did not receive any information about menstruation before menarche. It is thus seen that very few young girls between the age group 15 and 24 years did receive any information before the onset of menstruation. Among those who received some information, it was not adequate enough. The source of information was also not authentic. Both young and adult women agreed on this. Due to the inadequate knowledge, there were certain unhygienic practices followed by the young girls resulting in poor menstrual hygiene. It also leads to many unnecessary restrictions on young girls and they faced many health problems and complaints, which were either ignored or managed inappropriately. The role of health sector was almost negligible from giving information to the management of health problems of these young girls. This paper reemphasizes the important, urgent, and neglected need of providing correct knowledge to the community including adolescent girls.

  12. The Association between Endometriomas and Ovarian Cancer: Preventive Effect of Inhibiting Ovulation and Menstruation during Reproductive Life

    Directory of Open Access Journals (Sweden)

    Giovanni Grandi

    2015-01-01

    Full Text Available Although endometriosis frequently involves multiple sites in the pelvis, malignancies associated with this disease are mostly confined to the ovaries, evolving from an endometrioma. Endometriomas present a 2-3-fold increased risk of transformation in clear-cell, endometrioid, and possibly low-grade serous ovarian cancers, but not in mucinous ovarian cancers. These last cancers are, in some aspects, different from the other epithelial ovarian cancers, as they do not appear to be decreased by the inhibition of ovulation and menstruation. The step by step process of transformation from typical endometrioma, through atypical endometrioma, finally to ovarian cancer seems mainly related to oxidative stress, inflammation, hyperestrogenism, and specific molecular alterations. Particularly, activation of oncogenic KRAS and PI3K pathways and inactivation of tumor suppressor genes PTEN and ARID1A are suggested as major pathogenic mechanisms for endometriosis associated clear-cell and endometrioid ovarian cancer. Both the risk for endometriomas and their associated ovarian cancers seems to be highly and similarly decreased by the inhibition of ovulation and retrograde menstruation, suggesting a common pathogenetic mechanism and common possible preventive strategies during reproductive life.

  13. Basal concentrations of oestradiol may predict the outcome of in-vitro maturation in regularly menstruating women

    DEFF Research Database (Denmark)

    Mikkelsen, A L; Andersson, A M; Skakkebaek, N E

    2001-01-01

    and the number of oocytes respectively. The group with a low concentration of oestradiol on cycle day 3 (threshold or =10 pg/ml, n = 19). The pregnancy rate in group 1a (14/84, 17%) differed significantly from group 1b (0/19, 0%) (P = 0.03). It is concluded that a low basal concentration of oestradiol (......Retrospectively it was examined whether the number of retrieved oocytes, the maturation rate and cleavage rate can be predicted in regularly menstruating women by the use of the following predictive variables on cycle day 3-4: the concentration of FSH, oestradiol, inhibin B and inhibin A in serum......%) per aspiration and 15/83 (18%) per transfer. The concentration of FSH and the number of follicles on day 3 predicted the number of oocytes retrieved, whereas these parameters did not predict the subsequent development of oocytes. No correlation was found between the inhibin B, inhibin A, oestradiol...

  14. The effect of menstruation on chosen physiological and biochemical reactions caused by the physical effort with the submaximal intensity

    Directory of Open Access Journals (Sweden)

    P Zieliński

    2003-03-01

    Full Text Available The aim of this work was to determine the influence of the menstruation phase on changes of respective indicators of the gas exchange and on biochemical parameters of blood during physical efforts with the sub-maximal intensity. Fifteen female students of the Academy of Physical Education took part in the study. Girls were aged from 19 to 22 years old and did not practice sports. The effort tests were conducted in the follicular and luteal phase of two succeeding menstrual cycles. As far the aerobic capacity determination is concerned, one cyclo-ergometric test with graded effort was conducted and it was performed till the “refusal”. It allowed to mark a threshold (TDMA and a maximal level of physiological and biochemical indicators. Basing on the results of the graded test individual loads were determined for every next effort trial (repeated 4 times in every phase of the two succeeding menstrual cycles. The aim of this trial was to evaluate the reaction of women’s constitution on work with the sub-maximal intensity. The above trial consisted on two 10 min efforts divided with the 2 min pause (the first effort with the intensity of 80% of the TDMA threshold, second with the intensity bigger about 30-40% of difference between TDMA and a maximal load established by the graded test. The research did not reveal statistically significant differentiation as considering effort changes of basic physiological and biochemical indicators, determining reaction of women’s organisms on work with the sub- and over- threshold intensity (TDMA. It showed that menstruation has not significant effect on the level of changes of analysed parameters caused by the physical effort with the sub-maximal intensity.

  15. Prognostic Effects of Adjuvant Chemotherapy-Induced Amenorrhea and Subsequent Resumption of Menstruation for Premenopausal Breast Cancer Patients

    Science.gov (United States)

    Jeon, Se Jeong; Lee, Jae Il; Jeon, Myung Jae; Lee, Maria

    2016-01-01

    Abstract Chemotherapy-induced amenorrhea (CIA) is a side effect that occurs in patients with breast cancer (BC) as a result of chemotherapy. These patients require special treatments to avoid infertility and menopause. However, the factors controlling CIA, resumption of menstruation (RM), and persistence of menstruation after chemotherapy are unknown. The long-term prognosis for premenopausal patients with BC and the prognostic factors associated with CIA and RM are subject to debate. We performed a retrospective study by reviewing the medical records of 249 patients with BC (stage I to stage III) who were treated with cytotoxic chemotherapy. The median patient age was 43 (range, 26–55 years) and the median duration of follow-up was 64 months (range, 28–100 months). The medical records indicated that 219 patients (88.0%) scored as positive for the hormone receptor (HR); the majority of these patients completed chemotherapy and then received additional therapy of tamoxifen. Our analyses revealed that 88.0% (n = 219) of patients experienced CIA, and the percentage of RM during follow-up was 48.6% (n = 121). A total of 30 patients (12.0%) did not experience CIA. Disease-free survival (DFS) was affected by several factors, including tumour size ≥2 cm, node positivity, HR negative status, and body mass index ≥23 kg/m2. Multivariate analysis indicated that tumour size ≥2 cm remained as a significant factor for DFS (hazard ratio = 3.3, P = 0.034). In summary, this study finds that the majority of premenopausal patients with BC (stage I to stage III) who receive chemotherapy experience CIA and subsequent RM. Although tumour size ≥2 cm is negatively associated with DFS, RM after CIA is not associated with poor prognosis. PMID:27057900

  16. Sudden Ionospheric Disturbances (SID)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sudden ionospheric disturbances (SID) are caused by solar flare enhanced X-rays in the 1 to 10 angstrom range. Solar flares can produce large increases of ionization...

  17. Menstruation disorders in adolescents with eating disorders – target body mass index percentiles for their resolution

    Science.gov (United States)

    Vale, Beatriz; Brito, Sara; Paulos, Lígia; Moleiro, Pascoal

    2014-01-01

    ABSTRACT Objective: To analyse the progression of body mass index in eating disorders and to determine the percentile for establishment and resolution of the disease. Methods: A retrospective descriptive cross-sectional study. Review of clinical files of adolescents with eating disorders. Results: Of the 62 female adolescents studied with eating disorders, 51 presented with eating disorder not otherwise specified, 10 anorexia nervosa, and 1 bulimia nervosa. Twenty-one of these adolescents had menstrual disorders; in that, 14 secondary amenorrhea and 7 menstrual irregularities (6 eating disorder not otherwise specified, and 1 bulimia nervosa). In average, in anorectic adolescents, the initial body mass index was in 75th percentile; secondary amenorrhea was established 1 month after onset of the disease; minimum weight was 76.6% of ideal body mass index (at 4th percentile) at 10.2 months of disease; and resolution of amenorrhea occurred at 24 months, with average weight recovery of 93.4% of the ideal. In eating disorder not otherwise specified with menstrual disorder (n=10), the mean initial body mass index was at 85th percentile; minimal weight was in average 97.7% of the ideal value (minimum body mass index was in 52nd percentile) at 14.9 months of disease; body mass index stabilization occured at 1.6 year of disease; and mean body mass index was in 73rd percentile. Considering eating disorder not otherwise specified with secondary amenorrhea (n=4); secondary amenorrhea occurred at 4 months, with resolution at 12 months of disease (mean 65th percentile body mass index). Conclusion: One-third of the eating disorder group had menstrual disorder – two-thirds presented with amenorrhea. This study indicated that for the resolution of their menstrual disturbance the body mass index percentiles to be achieved by female adolescents with eating disorders was 25–50 in anorexia nervosa, and 50–75, in eating disorder not otherwise specified. PMID:25003922

  18. Migraine: is it related to hormonal disturbances or stress?

    Directory of Open Access Journals (Sweden)

    Parashar R

    2014-10-01

    Full Text Available Rachna Parashar,1 Payal Bhalla,2 Nirendra K Rai,3 Abhijit Pakhare,4 Rashmi Babbar5 1Department of Physiology, All India Institute of Medical Sciences, Bhopal, 2Department of Physiology, Vardhaman Mahavir Medical College, New Delhi, 3Department of Neurology, 4Department of Community and Family Medicine, All India Institute of Medical Sciences, Bhopal, 5Department of Physiology, Maulana Azad Medical College, New Delhi, India Background: Common neurological syndrome (migraine without aura is more common among women than men. Migraine is among the top 20 causes of disability. Menstruation is known to be a powerful trigger for migraine, and so is stress, but the presentation of headache is similar in both. Also, women are more vulnerable to stress as well as migraine, and this makes a complex relationship of menstruation, stress, and migraine. Objective: This study was done to understand the association of hormonal fluctuation in menstruation and stress with common migraine. Materials and methods: A cross-sectional comparative study was conducted in 40 young adult females, of whom 20 participants were cases of migraine without aura (18–35 years old, and the remaining 20 participants were age-matched controls. The study was done in Maulana Azad Medical College, New Delhi. Study participants were selected on the basis of International Headache Society (ICHD-IIA1.1 (2004 classification. Study participants with neurological disorders, chronic diseases, and disease suggestive of any hormonal disturbances were excluded. Clinically diagnosed migraine cases were asked to maintain a headache diary and to fill in the Depression Anxiety Stress Scales questionnaire. Biochemical assessment of hormonal status for thyroid-stimulating hormone, triiodothyronine, thyroxine, estrogen, follicle-stimulating hormone, luteinizing hormone, and prolactin was also done on the second day of their menstrual cycle. We used the Mann–Whitney U test to compare hormonal levels

  19. Disturbance recording system

    International Nuclear Information System (INIS)

    Chandra, A.K.; Deshpande, S.V.; Mayya, A.; Vaidya, U.W.; Premraj, M.K.; Patil, N.B.

    1994-01-01

    A computerized system for disturbance monitoring, recording and display has been developed for use in nuclear power plants and is versatile enough to be used where ever a large number of parameters need to be recorded, e.g. conventional power plants, chemical industry etc. The Disturbance Recording System (DRS) has been designed to continuously monitor a process plant and record crucial parameters. The DRS provides a centralized facility to monitor and continuously record 64 process parameters scanned every 1 sec for 5 days. The system also provides facility for storage of 64 parameters scanned every 200 msec during 2 minutes prior to and 3 minutes after a disturbance. In addition the system can initiate, on demand, the recording of 8 parameters at a fast rate of every 5 msec for a period of 5 sec. and thus act as a visicorder. All this data is recorded in non-volatile memory and can be displayed, printed/plotted and used for subsequent analysis. Since data can be stored densely on floppy disks, the volume of space required for archival storage is also low. As a disturbance recorder, the DRS allows the operator to view the state of the plant prior to occurrence of the disturbance and helps in identifying the root cause. (author). 10 refs., 7 figs

  20. Forest development leading to disturbances

    Science.gov (United States)

    Clinton E. Carlson; Stephen F. Arno; Jimmie Chew; Catherine A. Stewart

    1995-01-01

    Natural disturbance in western U.S.A. forest ecosystems is related to forest succession, growth, and structural development. Natural disturbance may be biotic (insects and diseases) or abiotic (fire, wind, avalanche, etc.). Natural disturbances are more appropriately thought of as natural processes; disturbance is a social connotation implicating economic loss. Forest...

  1. Postoperative circadian disturbances

    DEFF Research Database (Denmark)

    Gögenur, Ismail

    2010-01-01

    parameters, and if pharmacological administration of chronobiotics could improve postoperative recovery. Circadian rhythm disturbances were found in all the examined endogenous rhythms. A delay was found in the endogenous rhythm of plasma melatonin and excretion of the metabolite of melatonin (AMT6s...... in patients with lower than median pain levels for a three days period after laparoscopic cholecystectomy. In the series of studies included in this thesis we have systematically shown that circadian disturbances are found in the secretion of hormones, the sleep-wake cycle, core body temperature rhythm...

  2. Sleep disturbances in Parkinsonism.

    Science.gov (United States)

    Askenasy, J J M

    2003-02-01

    The present article is meant to suggest an approach to the guidelines for the therapy of sleep disturbances in Parkinson's Disease (PD) patients.The factors affecting the quality of life in PD patients are depression, sleep disturbances and dependence. A large review of the literature on sleep disturbances in PD patients, provided the basis for the following classification of the sleep-arousal disturbances in PD patients. We suggest a model based on 3 steps in the treatment of sleep disturbances in PD patients. This model allowing the patient, the spouse or the caregiver a quiet sleep at night, may postpone the retirement and the institutionalization of the PD patient. I. Correct diagnosis of sleep disorders based on detailed anamnesis of the patient and of the spouse or of the caregiver. One week recording on a symptom diary (log) by the patient or the caregiver. Correct diagnosis of sleep disorders co morbidities. Selection of the most appropriate sleep test among: polysomnography (PSG), multiple sleep latency test (MSLT), multiple wake latency test (MWLT), Epworth Sleepiness Scale, actigraphy or video-PSG. II. The nonspecific therapeutic approach consists in: a) Checking the sleep effect on motor performance, is it beneficial, worse or neutral. b) Psycho-physical assistance. c) Dopaminergic adjustment is necessary owing to the progression of the nigrostriatal degeneration and the increased sensitivity of the terminals, which alter the normal modulator mechanisms of the motor centers in PD patients. Among the many neurotransmitters of the nigro-striatal pathway one can distinguish two with a major influence on REM and NonREM sleep. REM sleep corresponds to an increased cholinergic receptor activity and a decreased dopaminergic activity. This is the reason why REM sleep deprivation by suppressing cholinergic receptor activity ameliorates PD motor symptoms. L-Dopa and its agonists by suppressing cholinergic receptors suppress REM sleep. The permanent adjustment

  3. Therapeutic and Ethical Dilemma of Puberty and Menstruation Problems in an Intellectually Disabled (Autistic) Female: a Case Report.

    Science.gov (United States)

    Memarian, Azadeh; Mehrpisheh, Shahrokh

    2015-10-01

    Intellectual disability is a term used when a person has certain limitations in mental functioning and skills. Autism is a group of developmental brain disorders, collectively called autism spectrum disorder (ASD). Teenagers with learning and physical disabilities are more likely to have menstrual problems compared to the general populations. The parents of a 12-year-old girl with autism spectrum disorder and intellectual disability referred to the coroner due to her numerous problems of puberty (menstruation) including: poor hygiene and polluting herself and the environment, not allowing to put or change the pads and changes in mood and physical health prior period, requested for the surgery (hysterectomy). In legal medicine organization after reviewing the medical records, physical exams and medical consultations with a gynecologist and psychiatric, surgery was not accepted. Hysterectomy (surgery) due to the age of the child, either physically or morally is not recommended. The use of hormone replacement therapy has side effects such as osteoporosis. In these cases, it seems noninvasive methods (behavioral therapy and learning care skills) under the welfare experts is also more effective and morally.

  4. ACOG Committee Opinion No. 651: Menstruation in Girls and Adolescents: Using the Menstrual Cycle as a Vital Sign.

    Science.gov (United States)

    2015-12-01

    Despite variations worldwide and within the U.S. population, median age at menarche has remained relatively stable-between 12 years and 13 years-across well-nourished populations in developed countries. Environmental factors, including socioeconomic conditions, nutrition, and access to preventive health care, may influence the timing and progression of puberty. A number of medical conditions can cause abnormal uterine bleeding, characterized by unpredictable timing and variable amount of flow. Clinicians should educate girls and their caretakers (eg, parents or guardians) about what to expect of a first menstrual period and the range for normal cycle length of subsequent menses. Identification of abnormal menstrual patterns in adolescence may improve early identification of potential health concerns for adulthood. It is important for clinicians to have an understanding of the menstrual patterns of adolescent girls, the ability to differentiate between normal and abnormal menstruation, and the skill to know how to evaluate the adolescent girl patient. By including an evaluation of the menstrual cycle as an additional vital sign, clinicians reinforce its importance in assessing overall health status for patients and caretakers.

  5. Committee Opinion No. 651 Summary: Menstruation in Girls and Adolescents: Using the Menstrual Cycle as a Vital Sign.

    Science.gov (United States)

    2015-12-01

    Despite variations worldwide and within the U.S. population, median age at menarche has remained relatively stable-between 12 years and 13 years-across well-nourished populations in developed countries. Environmental factors, including socioeconomic conditions, nutrition, and access to preventive health care, may influence the timing and progression of puberty. A number of medical conditions can cause abnormal uterine bleeding, characterized by unpredictable timing and variable amount of flow. Clinicians should educate girls and their caretakers (eg, parents or guardians) about what to expect of a first menstrual period and the range for normal cycle length of subsequent menses. Identification of abnormal menstrual patterns in adolescence may improve early identification of potential health concerns for adulthood. It is important for clinicians to have an understanding of the menstrual patterns of adolescent girls, the ability to differentiate between normal and abnormal menstruation, and the skill to know how to evaluate the adolescent girl patient. By including an evaluation of the menstrual cycle as an additional vital sign, clinicians reinforce its importance in assessing overall health status for patients and caretakers.

  6. The mind-tranquilizing and menstruation-regulating method for acupuncture treatment of delayed menstrual cycle--a clinical controlled study.

    Science.gov (United States)

    Cai, Xue-mei; Wu, Jie

    2009-03-01

    To compare the therapeutic effects of the mind-tranquilizing and menstruation-regulating acupuncture method with the routine acupuncture method in treating delayed menstrual cycle. 40 patients with delayed menstrual cycle were randomly divided into a treatment group of 23 cases (treated by the mind-tranquilizing and menstruation-regulating acupuncture method), and a control group of 17 cases (treated by the routine acupuncture method for delayed menstrual cycle due to stagnation of the liver-qi). The treatment involved three menstrual cycles. The evaluations were done by scoring the symptoms before treatment and at the end of each menstrual cycle. After treatment, significant differences were found between the two groups in the therapeutic effects (Pmenstrual cycle.

  7. DISTURBANCES OF LIPID METABOLISM

    Directory of Open Access Journals (Sweden)

    P. F. Litvitskii

    2012-01-01

    Full Text Available The article contains modern data on etiology, pathogenesis, manifestations and mechanisms of development of the most common forms of lipid metabolism disturbances in humans, such as obesity, emaciation, lipodystrophy, lipidosis, dyslipoproteinemia and atherosclerosis. The authors give the informative materials for self-testing and correction of the knowledge level.

  8. Nutritional disturbances by adolescent

    OpenAIRE

    Stassart, Martine

    2011-01-01

    The nutritional disturbances are frequent by adolescents. That is a psychological defense against dependance toward the mother but also a middle to remain in a childish position i.e. either as a fat baby - in the fall of obesity- or as the ideal pre- or bisexual great child - in the case of anorexia.

  9. Forest disturbances under climate change

    Science.gov (United States)

    Seidl, Rupert; Thom, Dominik; Kautz, Markus; Martin-Benito, Dario; Peltoniemi, Mikko; Vacchiano, Giorgio; Wild, Jan; Ascoli, Davide; Petr, Michal; Honkaniemi, Juha; Lexer, Manfred J.; Trotsiuk, Volodymyr; Mairota, Paola; Svoboda, Miroslav; Fabrika, Marek; Nagel, Thomas A.; Reyer, Christopher P. O.

    2017-06-01

    Forest disturbances are sensitive to climate. However, our understanding of disturbance dynamics in response to climatic changes remains incomplete, particularly regarding large-scale patterns, interaction effects and dampening feedbacks. Here we provide a global synthesis of climate change effects on important abiotic (fire, drought, wind, snow and ice) and biotic (insects and pathogens) disturbance agents. Warmer and drier conditions particularly facilitate fire, drought and insect disturbances, while warmer and wetter conditions increase disturbances from wind and pathogens. Widespread interactions between agents are likely to amplify disturbances, while indirect climate effects such as vegetation changes can dampen long-term disturbance sensitivities to climate. Future changes in disturbance are likely to be most pronounced in coniferous forests and the boreal biome. We conclude that both ecosystems and society should be prepared for an increasingly disturbed future of forests.

  10. 300 Area Disturbance Report

    Energy Technology Data Exchange (ETDEWEB)

    LL Hale; MK Wright; NA Cadoret

    1999-01-07

    The objective of this study was to define areas of previous disturbance in the 300 Area of the U.S. Department of Energy (DOE) Hanford Site to eliminate these areas from the cultural resource review process, reduce cultural resource monitoring costs, and allow cultural resource specialists to focus on areas where subsurface disturbance is minimal or nonexistent. Research into available sources suggests that impacts from excavations have been significant wherever the following construction activities have occurred: building basements and pits, waste ponds, burial grounds, trenches, installation of subsurface pipelines, power poles, water hydrants, and well construction. Beyond the areas just mentioned, substrates in the' 300 Area consist of a complex, multidimen- sional mosaic composed of undisturbed stratigraphy, backfill, and disturbed sediments; Four Geographic Information System (GIS) maps were created to display known areas of disturbance in the 300 Area. These maps contain information gleaned from a variety of sources, but the primary sources include the Hanford GIS database system, engineer drawings, and historic maps. In addition to these maps, several assumptions can be made about areas of disturbance in the 300 Area as a result of this study: o o Buried pipelines are not always located where they are mapped. As a result, cultural resource monitors or specialists should not depend on maps depicting subsurface pipelines for accurate locations of previous disturbance. Temporary roads built in the early 1940s were placed on layers of sand and gravel 8 to 12 in. thick. Given this information, it is likely that substrates beneath these early roads are only minimally disturbed. Building foundations ranged from concrete slabs no more than 6 to 8 in. thick to deeply excavated pits and basements. Buildings constructed with slab foundations are more numerous than may be expected, and minimally disturbed substrates may be expected in these locations. Historic

  11. Waveguide disturbance detection method

    Science.gov (United States)

    Korneev, Valeri A.; Nihei, Kurt T.; Myer, Larry R.

    2000-01-01

    A method for detection of a disturbance in a waveguide comprising transmitting a wavefield having symmetric and antisymmetric components from a horizontally and/or vertically polarized source and/or pressure source disposed symmetrically with respect to the longitudinal central axis of the waveguide at one end of the waveguide, recording the horizontal and/or vertical component or a pressure of the wavefield with a vertical array of receivers disposed at the opposite end of the waveguide, separating the wavenumber transform of the wavefield into the symmetric and antisymmetric components, integrating the symmetric and antisymmetric components over a broad frequency range, and comparing the magnitude of the symmetric components and the antisymmetric components to an expected magnitude for the symmetric components and the antisymmetric components for a waveguide of uniform thickness and properties thereby determining whether or not a disturbance is present inside the waveguide.

  12. The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding.

    Science.gov (United States)

    Schatz, Frederick; Guzeloglu-Kayisli, Ozlem; Arlier, Sefa; Kayisli, Umit A; Lockwood, Charles J

    2016-06-01

    Human pregnancy requires robust hemostasis to prevent hemorrhage during extravillous trophoblast (EVT) invasion of the decidualized endometrium, modification of spiral arteries and post-partum processes. However, decidual hemorrhage (abruption) can occur throughout pregnancy from poorly transformed spiral arteries, causing fetal death or spontaneous preterm birth (PTB), or it can promote the aberrant placentation observed in intrauterine growth restriction (IUGR) and pre-eclampsia; all leading causes of perinatal or maternal morbidity and mortality. In non-fertile cycles, the decidua undergoes controlled menstrual bleeding. Abnormal uterine bleeding (AUB) accompanying progestin-only, long-acting, reversible contraception (pLARC) accounts for most discontinuations of these safe and highly effective agents, thereby contributing to unwanted pregnancies and abortion. The aim of this study was to investigate the role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding. We conducted a critical review of the literature arising from PubMed searches up to December 2015, regarding in situ and in vitro expression and regulation of several specific proteins involved in uterine hemostasis in decidua and cycling endometrium. In addition, we discussed clinical and molecular mechanisms associated with pLARC-induced AUB and pregnancy complications with abruptions, chorioamnionitis or pre-eclampsia. Progestin-induced decidualization of estradiol-primed human endometrial stromal cells (HESCs) increases in vivo and in vitro expression of tissue factor (TF) and type-1 plasminogen activator inhibitor (PAI-1) while inhibiting plasminogen activators (PAs), matrix metalloproteinases (MMPs), and the vasoconstrictor, endothelin-1 (ET-1). These changes in decidual cell-derived regulators of hemostasis, fibrinolysis, extracellular matrix (ECM) turnover, and vascular tone prevent hemorrhage during EVT invasion and

  13. Atmospheric Disturbance Environment Definition

    Science.gov (United States)

    Tank, William G.

    1994-01-01

    Traditionally, the application of atmospheric disturbance data to airplane design problems has been the domain of the structures engineer. The primary concern in this case is the design of structural components sufficient to handle transient loads induced by the most severe atmospheric "gusts" that might be encountered. The concern has resulted in a considerable body of high altitude gust acceleration data obtained with VGH recorders (airplane velocity, V, vertical acceleration, G, altitude, H) on high-flying airplanes like the U-2 (Ehernberger and Love, 1975). However, the propulsion system designer is less concerned with the accelerations of the airplane than he is with the airflow entering the system's inlet. When the airplane encounters atmospheric turbulence it responds with transient fluctuations in pitch, yaw, and roll angles. These transients, together with fluctuations in the free-stream temperature and pressure will disrupt the total pressure, temperature, Mach number and angularity of the inlet flow. For the mixed compression inlet, the result is a disturbed throat Mach number and/or shock position, and in extreme cases an inlet unstart can occur (cf. Section 2.1). Interest in the effects of inlet unstart on the vehicle dynamics of large, supersonic airplanes is not new. Results published by NASA in 1962 of wind tunnel studies of the problem were used in support of the United States Supersonic Transport program (SST) (White, at aI, 1963). Such studies continued into the late 1970's. However, in spite of such interest, there never was developed an atmospheric disturbance database for inlet unstart analysis to compare with that available for the structures load analysis. Missing were data for the free-stream temperature and pressure disturbances that also contribute to the unStart problem.

  14. Disturbance dynamics of forested ecosystems

    Science.gov (United States)

    John A. Stanturf

    2004-01-01

    Forested ecosystems are dynamic, subject to natural developmental processes as well as natural and anthropogenic stresses and disturbances. Degradation is a related term. for lowered productive capacity from changes to forest structure of function (FAO. 2001). Degradation is not synonymous with disturbance, however; disturbance becomes degradation when natural...

  15. Disturbance by optimal discrimination

    Science.gov (United States)

    Kawakubo, Ryûitirô; Koike, Tatsuhiko

    2018-03-01

    We discuss the disturbance by measurements which unambiguously discriminate between given candidate states. We prove that such an optimal measurement necessarily changes distinguishable states indistinguishable when the inconclusive outcome is obtained. The result was previously shown by Chefles [Phys. Lett. A 239, 339 (1998), 10.1016/S0375-9601(98)00064-4] under restrictions on the class of quantum measurements and on the definition of optimality. Our theorems remove these restrictions and are also applicable to infinitely many candidate states. Combining with our previous results, one can obtain concrete mathematical conditions for the resulting states. The method may have a wide variety of applications in contexts other than state discrimination.

  16. Sleep Disturbances in Newborns

    Directory of Open Access Journals (Sweden)

    Daphna Yasova Barbeau

    2017-10-01

    Full Text Available The purpose of this review is to serve as an introduction to understanding sleep in the fetus, the preterm neonate and the term neonate. Sleep appears to have numerous important roles, particularly in the consolidation of new information. The sleep cycle changes over time, neonates spend the most time in active sleep and have a progressive shortening of active sleep and lengthening of quiet sleep. Additionally, the sleep cycle is disrupted by many things including disease state and environment, and the amplitude integrated EEG can be a useful tool in evaluating sleep, and sleep disturbances, in neonates. Finally, there are protective factors for infant sleep that are still being studied.

  17. Menstruation and Menstrual Problems

    Science.gov (United States)

    ... a Program Officer Forms Clinical Research Newsroom News Digital Media Join NICHD Listservs About NICHD Organization History Accomplishments Leadership & Other Staff Profiles Budget & Appropriations Advisory Groups Jobs ...

  18. Sleep disturbance in menopause.

    Science.gov (United States)

    Ameratunga, D; Goldin, J; Hickey, M

    2012-07-01

    Sleep disturbance during menopause is a common and important complaint faced by many women. There are many factors that may play a role in this problem, including vasomotor symptoms and changing hormone levels, circadian rhythm abnormalities, exacerbation of primary insomnia, mood disorders, coexistent medical conditions as well as lifestyle factors. Sleep can be measured both objectively and subjectively; however, correlation between the two measures is not high. Most of the menopause-related sleep disturbances have been reported as qualitative in nature; however, there have also been studies showing changes in objective measures. This discrepancy has implications with regard to evaluation of research in sleep and menopause, as well as application in the clinical setting. Investigations of inadequate sleep and sleep problems during the menopausal period and obtaining a thorough understanding of the factors contributing to these problems are essential in formulating treatment strategies. Such strategies can vary from hormonal treatment and medications to lifestyle and behavioural modification. © 2012 The Authors. Internal Medicine Journal © 2012 Royal Australasian College of Physicians.

  19. 'We keep it secret so no one should know'--a qualitative study to explore young schoolgirls attitudes and experiences with menstruation in rural western Kenya.

    Directory of Open Access Journals (Sweden)

    Linda Mason

    Full Text Available BACKGROUND: Keeping girls in school offers them protection against early marriage, teen pregnancy, and sexual harms, and enhances social and economic equity. Studies report menstruation exacerbates school-drop out and poor attendance, although evidence is sparse. This study qualitatively examines the menstrual experiences of young adolescent schoolgirls. METHODS AND FINDINGS: The study was conducted in Siaya County in rural western Kenya. A sample of 120 girls aged 14-16 years took part in 11 focus group discussions, which were analysed thematically. The data gathered were supplemented by information from six FGDs with parents and community members. Emergent themes were: lack of preparation for menarche; maturation and sexual vulnerability; menstruation as an illness; secrecy, fear and shame of leaking; coping with inadequate alternatives; paying for pads with sex; and problems with menstrual hygiene. Girls were unprepared and demonstrated poor reproductive knowledge, but devised practical methods to cope with menstrual difficulties, often alone. Parental and school support of menstrual needs is limited, and information sparse or inaccurate. Girls' physical changes prompt boys and adults to target and brand girls as ripe for sexual activity including coercion and marriage. Girls admitted 'others' rather than themselves were absent from school during menstruation, due to physical symptoms or inadequate sanitary protection. They described difficulties engaging in class, due to fear of smelling and leakage, and subsequent teasing. Sanitary pads were valued but resource and time constraints result in prolonged use causing chafing. Improvised alternatives, including rags and grass, were prone to leak, caused soreness, and were perceived as harmful. Girls reported 'other girls' but not themselves participated in transactional sex to buy pads, and received pads from boyfriends. CONCLUSIONS: In the absence of parental and school support, girls cope

  20. Comparison of the Effect of Stretching Exercises and Mefenamic Acid on the Reduction of Pain and Menstruation Characteristics in Primary Dysmenorrhea: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Narges Motahari-Tabari

    2017-01-01

    Full Text Available Objectives: Dysmenorrhea is a common gynecologic disorder. Although non-steroidal anti-inflammatory drugs are commonly used, due to their side effects and lack of response in some individuals, other approaches such as exercise have been considered. This study compared the effect of stretching exercises and mefenamic acid on the reduction of pain and menstruation characteristics in primary dysmenorrhea. Methods: In this randomized clinical trial, 122 female students with moderate to severe dysmenorrhea were assessed and were placed in either the exercise or mefenamic acid group. The exercise program was performed for 15 minutes, three times a week and included a five-minute warm up and six belly and pelvic stretching exercises for 10 minutes. The mefenamic acid group received 250 mg capsules every eight hours from the onset of menstruation until pain relief. Both interventions were performed during two consecutive menstrual cycles. Pain intensity was measured using a 10 cm visual analog scale. Results: The mean pain intensity was significantly higher in the exercise group only in the first cycle (p = 0.058. In the second cycle, the mean difference in pain reduction in the exercise group was higher than the mefenamic group compared to the start of the study (p = 0.056 and the first cycle (p = 0.007. There was no significant difference in the severity and duration of pain between the groups (p > 0.050. Conclusions: Stretching exercises were as effective as mefenamic acid in the treatment of primary dysmenorrhea. Our results suggest that the effect of exercise on relieving menstruation pain increases over time.

  1. 'We keep it secret so no one should know'--a qualitative study to explore young schoolgirls attitudes and experiences with menstruation in rural western Kenya.

    Science.gov (United States)

    Mason, Linda; Nyothach, Elizabeth; Alexander, Kelly; Odhiambo, Frank O; Eleveld, Alie; Vulule, John; Rheingans, Richard; Laserson, Kayla F; Mohammed, Aisha; Phillips-Howard, Penelope A

    2013-01-01

    Keeping girls in school offers them protection against early marriage, teen pregnancy, and sexual harms, and enhances social and economic equity. Studies report menstruation exacerbates school-drop out and poor attendance, although evidence is sparse. This study qualitatively examines the menstrual experiences of young adolescent schoolgirls. The study was conducted in Siaya County in rural western Kenya. A sample of 120 girls aged 14-16 years took part in 11 focus group discussions, which were analysed thematically. The data gathered were supplemented by information from six FGDs with parents and community members. Emergent themes were: lack of preparation for menarche; maturation and sexual vulnerability; menstruation as an illness; secrecy, fear and shame of leaking; coping with inadequate alternatives; paying for pads with sex; and problems with menstrual hygiene. Girls were unprepared and demonstrated poor reproductive knowledge, but devised practical methods to cope with menstrual difficulties, often alone. Parental and school support of menstrual needs is limited, and information sparse or inaccurate. Girls' physical changes prompt boys and adults to target and brand girls as ripe for sexual activity including coercion and marriage. Girls admitted 'others' rather than themselves were absent from school during menstruation, due to physical symptoms or inadequate sanitary protection. They described difficulties engaging in class, due to fear of smelling and leakage, and subsequent teasing. Sanitary pads were valued but resource and time constraints result in prolonged use causing chafing. Improvised alternatives, including rags and grass, were prone to leak, caused soreness, and were perceived as harmful. Girls reported 'other girls' but not themselves participated in transactional sex to buy pads, and received pads from boyfriends. In the absence of parental and school support, girls cope, sometimes alone, with menarche in practical and sometimes hazardous

  2. Disturbance hydrology: Preparing for an increasingly disturbed future

    Science.gov (United States)

    Mirus, Benjamin B.; Ebel, Brian A.; Mohr, Christian H.; Zegre, Nicolas

    2017-01-01

    This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre- and post-disturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

  3. Postischaemic circulation disturbances.

    Science.gov (United States)

    Fuchs, U; Bodendieck, P

    1975-01-01

    Restoration of blood supply after ischaemic conditions in extremities and testes is inhibited by reversible intravasal aggregation of erythrocytes. This process is promoted by the increased permeability of the capillaries associated with the formation of oedema and the entailing increase of the haematocrit. For overcoming the stasis the increased structural viscosity caused by the aggregation of erythrocytes requires an increase in pressure as a starter effect which is not achieved by the flow pressure at once everywhere. Intravenously administered particles of Indian ink mark the formation and dissolution of aggregates. Even areas with originally normal blood supply may be obstructed by the later formation of aggregates. Thrombi on the walls of arterial and venous vessels and other lesions of the intima do not sufficiently explain the disturbance of perfusion. Oedema and extravasating leucocytes are found in the microcirculation. The parenchyma to be supplied shows formation of necrosis.

  4. Sleep Disturbances in Mood Disorders.

    Science.gov (United States)

    Rumble, Meredith E; White, Kaitlin Hanley; Benca, Ruth M

    2015-12-01

    The article provides an overview of common and differentiating self-reported and objective sleep disturbances seen in mood-disordered populations. The importance of considering sleep disturbances in the context of mood disorders is emphasized, because a large body of evidence supports the notion that sleep disturbances are a risk factor for onset, exacerbation, and relapse of mood disorders. In addition, potential mechanisms for sleep disturbance in depression, other primary sleep disorders that often occur with mood disorders, effects of antidepressant and mood-stabilizing drugs on sleep, and the adjunctive effect of treating sleep in patients with mood disorders are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Influence of Diet, Menstruation and Genetic Factors on Iron Status: A Cross-Sectional Study in Spanish Women of Childbearing Age

    Directory of Open Access Journals (Sweden)

    Ruth Blanco-Rojo

    2014-03-01

    Full Text Available The aim of this study was to investigate the combined influence of diet, menstruation and genetic factors on iron status in Spanish menstruating women (n = 142. Dietary intake was assessed by a 72-h detailed dietary report and menstrual blood loss by a questionnaire, to determine a Menstrual Blood Loss Coefficient (MBLC. Five selected SNPs were genotyped: rs3811647, rs1799852 (Tf gene; rs1375515 (CACNA2D3 gene; and rs1800562 and rs1799945 (HFE gene, mutations C282Y and H63D, respectively. Iron biomarkers were determined and cluster analysis was performed. Differences among clusters in dietary intake, menstrual blood loss parameters and genotype frequencies distribution were studied. A categorical regression was performed to identify factors associated with cluster belonging. Three clusters were identified: women with poor iron status close to developing iron deficiency anemia (Cluster 1, n = 26; women with mild iron deficiency (Cluster 2, n = 59 and women with normal iron status (Cluster 3, n = 57. Three independent factors, red meat consumption, MBLC and mutation C282Y, were included in the model that better explained cluster belonging (R2 = 0.142, p < 0.001. In conclusion, the combination of high red meat consumption, low menstrual blood loss and the HFE C282Y mutation may protect from iron deficiency in women of childbearing age. These findings could be useful to implement adequate strategies to prevent iron deficiency anemia.

  6. Disturbance Hydrology: Preparing for an Increasingly Disturbed Future

    Science.gov (United States)

    Mirus, Benjamin B.; Ebel, Brian A.; Mohr, Christian H.; Zegre, Nicolas

    2017-12-01

    This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre and postdisturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

  7. Menstruation in history La menstruación en la historia A menstruação na história

    Directory of Open Access Journals (Sweden)

    Pio Iván Gómez-Sánchez

    2012-08-01

    Full Text Available Objective. To review historical constructs on menstruation. Methodology. Non-systematic review of the literature complemented with consultations with national academic authorities. Results. Menstruation is an experience that involves women and their social group, becoming a relevant event. Treatment of menstrual symptoms is linked to the cultural context in which it is developed. The menstruation experience varies according to popular beliefs, cultural characteristics, and information received to this respect within the social group where the woman is. Menstruation exceeds the imaginary that places it only within the feminine setting; It is a process that involves the social group, inasmuch as it has psycho-social and cultural implications. Conclusion. A relationship exists between menstruation, as a biological event, and the social processes per se, influenced by the historical beliefs that have been transmitted generation after generation.Objetivo. Revisar los constructos históricos sobre la menstruación. Metodología. Revisión no sistemática de la literatura complementada con consultas a autoridades académicas nacionales. Resultados. La menstruación es una experiencia que involucra tanto a la mujer como a su grupo social, convirtiéndose en un suceso relevante. El tratamiento de sus síntomas se encuentra ligado al contexto cultural en el cual se desarrolla. La experiencia de la menstruación varía de acuerdo con las creencias populares, las características culturales y la información que se reciba al respecto en el grupo social. La menstruación excede el imaginario que la sitúa únicamente en el ámbito de lo femenino; es un proceso que involucra al grupo social, en tanto que tiene implicaciones sicosociales y culturales. Conclusión. Hay relación entre la menstruación, como hecho biológico, y los procesos sociales en sí, influenciados por las creencias históricas que se han transmitido generación tras generaci

  8. Sleep disturbances and glucose homeostasis

    NARCIS (Netherlands)

    Barf, R. Paulien; Scheurink, Anton J.W.

    2011-01-01

    Sleep disturbances, induced by either lifestyle, shift work or sleeping disorders, have become more prevalent in our 24/7 Western society. Sleep disturbances are associated with impaired health including metabolic diseases such as obesity and type 2 diabetes. The question remains whether there is a

  9. Disturbance Decoupling in Dynamic Games

    NARCIS (Netherlands)

    van den Broek, W.A.; Schumacher, J.M.

    1999-01-01

    A theory for disturbance decoupling problems has been well developed in the area of geometric control theory. The aim of the present study is to introduce disturbance decoupling problems in a dynamic game context. For this purpose, techniques from geometric control theory are applied. Necessary and

  10. Computer aided analysis of disturbances

    International Nuclear Information System (INIS)

    Baldeweg, F.; Lindner, A.

    1986-01-01

    Computer aided analysis of disturbances and the prevention of failures (diagnosis and therapy control) in technological plants belong to the most important tasks of process control. Research in this field is very intensive due to increasing requirements to security and economy of process control and due to a remarkable increase of the efficiency of digital electronics. This publication concerns with analysis of disturbances in complex technological plants, especially in so called high risk processes. The presentation emphasizes theoretical concept of diagnosis and therapy control, modelling of the disturbance behaviour of the technological process and the man-machine-communication integrating artificial intelligence methods, e.g., expert system approach. Application is given for nuclear power plants. (author)

  11. Managing Sleep Disturbances in Cirrhosis

    Directory of Open Access Journals (Sweden)

    Xun Zhao

    2016-01-01

    Full Text Available Sleep disturbances, particularly daytime sleepiness and insomnia, are common problems reported by patients suffering from liver cirrhosis. Poor sleep negatively impacts patients’ quality of life and cognitive functions and increases mortality. Although sleep disturbances can be an early sign of hepatic encephalopathy (HE, many patients without HE still complain of poor quality sleep. The pathophysiology of these disturbances is not fully understood but is believed to be linked to impaired hepatic melatonin metabolism. This paper provides an overview for the clinician of common comorbidities contributing to poor sleep in patients with liver disease, mainly restless leg syndrome and obstructive sleep apnea. It discusses nondrug and pharmacologic treatment options in these patients, such as the use of light therapy and histamine (H1 blockers.

  12. Family constellation and psychosexual disturbances.

    Science.gov (United States)

    Lidberg, L

    1976-08-01

    In patients with psychosexual disturbances (impotence and ejaculatio praecox) the family constellation during childhood and the patients' occupations were compared with the Swedish population census. The parents of the patients were older, and the patients were more often the only son or the only child. A greater percentage of the patients had technical or office administrative professions than the inhabitants in Stockholm. The findings are discussed with references to a supposed focus on achievement in the upbringing of the oldest or only son. Focus on achievement may cause emotional restraint and subsequently psychosexual disturbances.

  13. Plasma lipid peroxidation, blood GSH concentration and erythrocyte antioxidant enzymes in menstruating females with ovulatory and anovulatory cycles compared with males

    Directory of Open Access Journals (Sweden)

    G Lutosławska

    2003-12-01

    Full Text Available This study was undertaken to evaluate plasma TBARS and blood GSH concentration and erythrocyte antioxidant enzymes (glutathione peroxidase, catalase and superoxide dismutase in active, regularly menstruating female physical education students with ovulatory and anovulatory menstrual cycles and in their male counterparts. A total of 27 subjects (12 males and 15 females volunteered to participate in the study. All females were regularly menstruating with cycle length between 26-31 days. Plasma progesterone and 17-β-estradiol concentrations were assayed during the 7th-9th and 22nd-25th day of the menstrual cycle. Women with plasma progesterone concentration exceeding 19 nmol•l-1 during the 22nd-25th day were referred to as ovulatory (Group OV; n=7. Women without a peak plasma progesterone concentration were referred to as anovulatory (Group AN; n=8. Blood from male subjects was withdrawn twice - two weeks apart, at their convenience. It was found that the menstrual cycle phases did not affect plasma TBARS and blood glutathione concentration and erythrocyte GPX, CAT and SOD activity. However, erythrocyte GPX activity either in ovulatory or anovulatory women was by about 30% higher than in male subjects. Erythrocyte SOD activity in ovulatory women both in follicular and luteal phase of the menstrual cycle (1557 U/g Hb and 1394.6 U/g Hb, respectively was markedly lower than in men (1951.8 and 1937.7 U/g Hb for blood sampling I and II, respectively. In contrast, erythrocyte SOD activity in anovulatory women (1855.5 U/g Hb and 1745.7 U/g Hb in the follicular and luteal phases, respectively was similar to that found in men. The above data indicated that erythrocyte GPX and SOD activities are sensitive to plasma ovarian hormone concentration. In addition, they suggested that due to higher erythrocyte GPX activity females even with anovulatory menstrual cycles are protected better than males against hydrogen peroxide action. However, lower superoxide

  14. Adaptive stochastic disturbance accommodating control

    Science.gov (United States)

    George, Jemin; Singla, Puneet; Crassidis, John L.

    2011-02-01

    This article presents a Kalman filter based adaptive disturbance accommodating stochastic control scheme for linear uncertain systems to minimise the adverse effects of both model uncertainties and external disturbances. Instead of dealing with system uncertainties and external disturbances separately, the disturbance accommodating control scheme lumps the overall effects of these errors in a to-be-determined model-error vector and then utilises a Kalman filter in the feedback loop for simultaneously estimating the system states and the model-error vector from noisy measurements. Since the model-error dynamics is unknown, the process noise covariance associated with the model-error dynamics is used to empirically tune the Kalman filter to yield accurate estimates. A rigorous stochastic stability analysis reveals a lower bound requirement on the assumed system process noise covariance to ensure the stability of the controlled system when the nominal control action on the true plant is unstable. An adaptive law is synthesised for the selection of stabilising system process noise covariance. Simulation results are presented where the proposed control scheme is implemented on a two degree-of-freedom helicopter.

  15. [Tooth eruption disturbances and syndromes

    NARCIS (Netherlands)

    Oosterkamp, B.A.M. van; Ockeloen, C.W.; Carels, C.E.L.; Kuijpers-Jagtman, A.M.

    2014-01-01

    In the tooth eruption mechanism, various disturbances can appear as a result of gene mutations, a consequence of which can be that tooth eruption does not occur. There are 5 syndromes which involve the complete failure of several or even all teeth to erupt, specifically: cleidocranial dysplasia,

  16. Forest disturbances under climate change

    Czech Academy of Sciences Publication Activity Database

    Seidl, R.; Thom, D.; Kautz, M.; Martin-Benito, D.; Peltoniemi, M.; Vacchiano, G.; Wild, Jan; Ascoli, D.; Petr, M.; Honkaniemi, J.; Lexer, M. J.; Trotsiuk, V.; Mairota, P.; Svoboda, M.; Fabrika, M.; Nagel, T.A.; Reyer, C. P. O.

    2017-01-01

    Roč. 7, č. 6 (2017), s. 395-402 ISSN 1758-678X R&D Projects: GA MŠk(CZ) LD15158 Institutional support: RVO:67985939 Keywords : climate change * disturbance * forest Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 19.304, year: 2016

  17. Therapeutic and Ethical Dilemma of Puberty and Menstruation Problems in an Intellectually Disabled (Autistic Female: a Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Azadeh Memarian

    2015-10-01

    Full Text Available Intellectual disability is a term used when a person has certain limitations in mental functioning and skills. Autism is a group of developmental brain disorders, collectively called autism spectrum disorder (ASD. Teenagers with learning and physical disabilities are more likely to have menstrual problems compared to the general populations. The parents of a 12-year-old girl with autism spectrum disorder and intellectual disability referred to the coroner due to her numerous problems of puberty (menstruation including: poor hygiene and polluting herself and the environment, not allowing to put or change the pads and changes in mood and physical health prior period, requested for the surgery (hysterectomy. In legal medicine organization after reviewing the medical records, physical exams and medical consultations with a gynecologist and psychiatric, surgery was not accepted. Hysterectomy (surgery due to the age of the child, either physically or morally is not recommended. The use of hormone replacement therapy has side effects such as osteoporosis. In these cases, it seems noninvasive methods (behavioral therapy and learning care skills under the welfare experts is also more effective and morally.

  18. Natural disturbances and Kyoto protocol

    Directory of Open Access Journals (Sweden)

    Teobaldelli M

    2008-06-01

    Full Text Available A recent letter published in Nature (Kurz et al. 2008a reports an outbreak of mountain pine beetles in British Columbia, destroying millions of trees; according to the authors, by 2020, the beetles will have done so much damage that the forest is expected to release more carbon dioxide than it absorbs. All those natural disturbances could overwhelmed all the efforts made by Canada to influence the carbon balance through forest management. Considering that Canada decided not to elect forest management within the Kyoto Protocol, it is clear that future climate mitigation agreements, aimed to encourage changes in forest management, should account for and protect against the impacts of natural disturbances.

  19. Disturbances in small bowel motility.

    LENUS (Irish Health Repository)

    Quigley, E M

    2012-02-03

    Recently, the small intestine has become the focus of investigation as a potential site of dysmotility in the irritable bowel syndrome (IBS). A number of motor abnormalities have been defined in some studies, and include \\'clustered\\' contractions, exaggerated post-prandial motor response and disturbances in intestinal transit. The significance of these findings remains unclear. The interpretation of available studies is complicated by differences in subject selection, the direct influence of certain symptoms, such as diarrhoea and constipation, and the interference of compounding factors, such as stress and psychopathology. Dysmotility could also reflect autonomic dysfunction, disturbed CNS control and the response to heightened visceral sensation or central perception. While motor abnormalities may not explain all symptoms in IBS, sensorimotor interactions may be important in symptom pathogenesis and deserve further study.

  20. Extended Active Disturbance Rejection Controller

    Science.gov (United States)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2016-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  1. Postradiation disturbances of neuroendocrinal interaction

    International Nuclear Information System (INIS)

    Dedov, V.I.

    1980-01-01

    Analysis of data on the disturbances induced by ionizing irradiation in endocrine organs is given on the basis of experimental material. Mechanism and dynamics of the radiation pathology of such organs of endocrine system as hypothalamus, hypophysis, adrenal glands, thyroid, gonads are considered. Necessity of the determination of criteria of injury significance and study of delayed effects of ionizing radiation in perspective investigation of the problems of endocrine radiation pathology is pointed out

  2. Sleep Disturbance and Anatomic Shoulder Arthroplasty.

    Science.gov (United States)

    Morris, Brent J; Sciascia, Aaron D; Jacobs, Cale A; Edwards, T Bradley

    2017-05-01

    Sleep disturbance is commonly encountered in patients with glenohumeral joint arthritis and can be a factor that drives patients to consider surgery. The prevalence of sleep disturbance before or after anatomic total shoulder arthroplasty has not been reported. The authors identified 232 eligible patients in a prospective shoulder arthroplasty registry following total shoulder arthroplasty for primary glenohumeral joint arthritis with 2- to 5-year follow-up. Sleep disturbance secondary to the affected shoulder was characterized preoperatively and postoperatively as no sleep disturbance, frequent sleep disturbance, or nightly sleep disturbance. A total of 211 patients (91%) reported sleep disturbance prior to surgery. Patients with nightly sleep disturbance had significantly worse (Psleep disturbance, with 186 patients (80%) reporting no sleep disturbance (Psleep disturbance group had significantly greater patient-reported outcome scores and range of motion following surgery compared with the other sleep disturbance groups for nearly all outcome measures (P≤.01). Patients have significant improvements in sleep after anatomic shoulder arthroplasty. There was a high prevalence of sleep disturbance preoperatively (211 patients, 91%) compared with postoperatively (46 patients, 20%). [Orthopedics. 2017; 40(3):e450-e454.]. Copyright 2017, SLACK Incorporated.

  3. Neurobiological basis of parenting disturbance.

    Science.gov (United States)

    Newman, Louise K; Harris, Melissa; Allen, Joanne

    2011-02-01

    It has been proposed that early attachment relationships shape the structure and reactivity of social brain structures that underlie later social capacities. We provide a review of the literature surrounding the development of neurological regulatory systems during infancy and outline recent research suggesting these systems go on to underlie adaptive parental responses. We review evidence in the peer-reviewed psychiatric literature including (i) observational human literature on the neurobiological and social sequelae of early parenting experiences, (ii) experimental animal literature on the effects of early maternal care on neurological development, (iii) experimental animal literature on the neurobiological underpinnings of parenting behaviours, (iv) observational and fMRI evidence on the neurobiological correlates of parenting behaviours, (v) functional and volumetric imaging studies on adults affected by borderline personality disorder. The development of infant regulatory systems is influenced by early parenting experiences. These frontolimbic regulatory systems are also heavily implicated in normal parental responses to infant cues. These frontolimbic disturbances are also observed in studies of borderline personality disorder; a disorder associated with poor emotional regulation, early trauma and disturbed parenting. While the current literature is limited to animal models of abnormal care giving, existing disorders associated with deficits in regulatory capacity and abnormal frontolimbic functioning may yet provide a human model of the neurobiology of parenting disturbance.

  4. Wind Power Prediction Considering Nonlinear Atmospheric Disturbances

    OpenAIRE

    Yagang Zhang; Jingyun Yang; Kangcheng Wang; Zengping Wang

    2015-01-01

    This paper considers the effect of nonlinear atmospheric disturbances on wind power prediction. A Lorenz system is introduced as an atmospheric disturbance model. Three new improved wind forecasting models combined with a Lorenz comprehensive disturbance are put forward in this study. Firstly, we define the form of the Lorenz disturbance variable and the wind speed perturbation formula. Then, different artificial neural network models are used to verify the new idea and obtain better wind spe...

  5. Disturbance Decoupling of Switched Linear Systems

    NARCIS (Netherlands)

    Yurtseven, E.; Heemels, W.P.M.H.; Camlibel, M.K.

    2010-01-01

    In this paper we consider disturbance decoupling problems for switched linear systems. We will provide necessary and sufficient conditions for three different versions of disturbance decoupling, which differ based on which signals are considered to be the disturbance. In the first version the

  6. Model of traveling ionospheric disturbances

    Directory of Open Access Journals (Sweden)

    Fedorenko Yury P.

    2013-10-01

    Full Text Available A multiscale semi-empirical model of traveling ionospheric disturbances (TIDs is developed. The model is based on the following assumptions: (1 TIDs are generated by acoustic-gravity waves (AGWs and propagate as pressure waves; (2 time intervals between adjacent extrema of atmospheric pressure oscillations in a disturbance source are constant; (3 the pressure extrema propagate from the source up to ~14 000 km at a constant horizontal velocity; (4 the velocity of each extremum is determined only by its number in a TID train. The model was validated using literature data on disturbances generated by about 20 surface and high-altitude nuclear explosions, two volcano explosions, one earthquake and by energetic proton precipitation events in the magnetospheric cusp of the northern hemisphere. Model tests using literature data show that the spatial and temporal TID periods may be predicted with an accuracy of 12%. Adequacy of the model was also confirmed by our observations collected using transionospheric sounding. The following TID parameters: amplitudes, horizontal spatial periods, and a TID front inclination angle in a vertical plane are increasing as the distance between an AGW and the excitation source is increasing. Diurnal and seasonal variability of the TID occurrence, defined as ratio of TID events to the total number of observations for the corresponding period, is not observed. However, the TID occurrence was growing from ~50% in 1987 to ~98% in 2010. The results of other studies asserting that the TID occurrence does not depend on the number of sunspots and magnetic activity are confirmed. The TID occurrence has doubled over the period from 1987 to 2010 indicating increasing solar activity which is not associated with sunspot numbers. The dynamics of spatial horizontal periods was studied in a range of 150–35 000 km.

  7. [Tooth eruption disturbances and syndromes].

    Science.gov (United States)

    Oosterkamp, B C M; Ockeloen, C W; Carels, C E L; Kuijpers-Jagtman, A M

    2014-04-01

    In the tooth eruption mechanism, various disturbances can appear as a result of gene mutations, a consequence of which can be that tooth eruption does not occur. There are 5 syndromes which involve the complete failure of several or even all teeth to erupt, specifically: cleidocranial dysplasia, Gardner's syndrome, osteopetrosis, mucopolysaccharidosis and GAPO syndrome. Some are very rare and will seldom be encountered in a dental practice, but they show how vulnerable the tooth eruption mechanism is. Dentists are generally the ones who identify a tooth eruption problem in a patient. Since syndromes can be associated with other disorders, additional investigation by a clinical geneticist is always important when a syndrome is suspected.

  8. Implications of recurrent disturbance for genetic diversity.

    Science.gov (United States)

    Davies, Ian D; Cary, Geoffrey J; Landguth, Erin L; Lindenmayer, David B; Banks, Sam C

    2016-02-01

    Exploring interactions between ecological disturbance, species' abundances and community composition provides critical insights for ecological dynamics. While disturbance is also potentially an important driver of landscape genetic patterns, the mechanisms by which these patterns may arise by selective and neutral processes are not well-understood. We used simulation to evaluate the relative importance of disturbance regime components, and their interaction with demographic and dispersal processes, on the distribution of genetic diversity across landscapes. We investigated genetic impacts of variation in key components of disturbance regimes and spatial patterns that are likely to respond to climate change and land management, including disturbance size, frequency, and severity. The influence of disturbance was mediated by dispersal distance and, to a limited extent, by birth rate. Nevertheless, all three disturbance regime components strongly influenced spatial and temporal patterns of genetic diversity within subpopulations, and were associated with changes in genetic structure. Furthermore, disturbance-induced changes in temporal population dynamics and the spatial distribution of populations across the landscape resulted in disrupted isolation by distance patterns among populations. Our results show that forecast changes in disturbance regimes have the potential to cause major changes to the distribution of genetic diversity within and among populations. We highlight likely scenarios under which future changes to disturbance size, severity, or frequency will have the strongest impacts on population genetic patterns. In addition, our results have implications for the inference of biological processes from genetic data, because the effects of dispersal on genetic patterns were strongly mediated by disturbance regimes.

  9. All about Menstruation (For Children)

    Science.gov (United States)

    ... Things That Help Feelings Expert Answers Q&A Movies & More for Teens Teens site Sitio para adolescentes ... in a carton at the store! Girls and women have two ovaries. Each of these ovaries holds ...

  10. All about Menstruation (For Teens)

    Science.gov (United States)

    ... girl might notice an increased amount of clear vaginal discharge. This discharge is common. There's no need for ... topic for: Teens Why Are My Breasts Sore? Vaginal Discharge: What's Normal, What's Not Tampons, Pads, and Other ...

  11. Menstruation and Education in Nepal

    OpenAIRE

    Emily Oster; Rebecca Thornton

    2009-01-01

    This paper presents the results from a randomized evaluation that distributed menstrual cups (menstrual sanitary products) to adolescent girls in rural Nepal. Girls in the study were randomly allocated a menstrual cup for use during their monthly period and were followed for fifteen months to measure the effects of having modern sanitary products on schooling. While girls were 3 percentage points less likely to attend school on days of their period, we find no significant effect of being allo...

  12. Disturbance maintains alternative biome states.

    Science.gov (United States)

    Dantas, Vinícius de L; Hirota, Marina; Oliveira, Rafael S; Pausas, Juli G

    2016-01-01

    Understanding the mechanisms controlling the distribution of biomes remains a challenge. Although tropical biome distribution has traditionally been explained by climate and soil, contrasting vegetation types often occur as mosaics with sharp boundaries under very similar environmental conditions. While evidence suggests that these biomes are alternative states, empirical broad-scale support to this hypothesis is still lacking. Using community-level field data and a novel resource-niche overlap approach, we show that, for a wide range of environmental conditions, fire feedbacks maintain savannas and forests as alternative biome states in both the Neotropics and the Afrotropics. In addition, wooded grasslands and savannas occurred as alternative grassy states in the Afrotropics, depending on the relative importance of fire and herbivory feedbacks. These results are consistent with landscape scale evidence and suggest that disturbance is a general factor driving and maintaining alternative biome states and vegetation mosaics in the tropics. © 2015 John Wiley & Sons Ltd/CNRS.

  13. Neuroendocrine Disturbances in Huntington's Disease

    Science.gov (United States)

    Saleh, Nadine; Moutereau, Stéphane; Durr, Alexandra; Krystkowiak, Pierre; Azulay, Jean-Philippe; Tranchant, Christine; Broussolle, Emmanuel; Morin, Françoise; Bachoud-Lévi, Anne-Catherine; Maison, Patrick

    2009-01-01

    Background Huntington's disease (HD) is a severe inherited neurodegenerative disorder characterized, in addition to neurological impairment, by weight loss suggesting endocrine disturbances. The aims of this study were to look for neuroendocrine disturbances in patients with Huntington's disease (HD) and to determine the relationship with weight loss seen in HD Methods and Finding We compared plasma levels of hormones from the five pituitary axes in 219 patients with genetically documented HD and in 71 sex- and age-matched controls. Relationships between hormone levels and disease severity, including weight-loss severity, were evaluated. Growth hormone (GH) and standard deviation score of insulin-like growth factor 1 (SDS IGF-1) were significantly higher in patients than in controls (0.25 (0.01–5.89) vs. 0.15 (0.005–4.89) ng/ml, p = 0.013 and 0.16±1.02 vs. 0.06±0.91, p = 0.039; respectively). Cortisol was higher (p = 0.002) in patients (399.14±160.5 nmol/L vs. 279.8±130.1 nmol/L), whereas no differences were found for other hormone axes. In patients, elevations in GH and IGF-1 and decreases in thyroid-stimulating hormone, free triiodothyronine and testosterone (in men) were associated with severity of impairments (Independence scale, Functional score, Total Functional Capacity, Total Motor score, Behavioral score). Only GH was independently associated with body mass index (β = −0.26, p = 0.001). Conclusion Our data suggest that the thyrotropic and in men gonadotropic axes are altered in HD according to the severity of the disease. The somatotropic axis is overactive even in patients with early disease, and could be related to the weight loss seen in HD patients. PMID:19319184

  14. Menstruation and the Cycle of Poverty: A Cluster Quasi-Randomised Control Trial of Sanitary Pad and Puberty Education Provision in Uganda

    Science.gov (United States)

    Montgomery, Paul; Hennegan, Julie; Dolan, Catherine; Wu, Maryalice; Steinfield, Laurel; Scott, Linda

    2016-01-01

    Background Poor menstrual knowledge and access to sanitary products have been proposed as barriers to menstrual health and school attendance. In response, interventions targeting these needs have seen increasing implementation in public and private sectors. However, there has been limited assessment of their effectiveness. Objectives Assess the impact of providing reusable sanitary pads and puberty education on girls’ school attendance and psychosocial wellbeing outcomes. Methods A cluster quasi-randomised controlled trial was conducted across 8 schools, including 1124 girls, in rural Uganda. Schools were allocated to one of four conditions: the provision of puberty education alone; reusable sanitary pads alone; puberty education and reusable sanitary pads; and a control (no intervention). The primary outcome was school attendance. Secondary outcomes reflected psychosocial wellbeing. Results At follow-up, school attendance had worsened for girls across all conditions. Per-protocol analysis revealed that this decline was significantly greater for those in the control condition d = 0.52 (95%CI 0.26–0.77), with those in control schools having a 17.1% (95%CI: 8.7–25.5) greater drop in attendance than those in any intervention school. There were no differences between the intervention conditions. High rates of school drop-out and transfer meant the trial suffered from substantial participant drop-out. Intention-to-treat analyses using two different imputation strategies were consistent with the main results, with mean differences of 5.2% attendance in best-case and 24.5% in worst-case imputations. Results were robust to adjustments for clustering. There was no impact of the interventions on girls’ self-reported shame or insecurity during menstruation. Conclusion Results of the trial support the hypothesised positive impact of providing sanitary pads or puberty education for girls’ school attendance in a developing country context. Findings must be interpreted

  15. Disturbance size and severity covary in small and mid-size wind disturbances in Pennsylvania northern hardwoods forests

    Science.gov (United States)

    Chris J. Peterson; Lisa M. Krueger; Alejandro A. Royo; Scott Stark; Walter P. Carson

    2013-01-01

    Do large disturbances differ from small ones in characteristics other than size? The importance of disturbances in forest dynamics is unquestioned, and the size of the disturbed area (size of gap) is the most common way of differentiating disturbances. But few studies have examined other disturbance characteristics to see if small and large disturbances are different....

  16. Identity disturbance in distant patients.

    Science.gov (United States)

    Hoffman, Irwin

    2013-04-01

    Chronically distant, emotionally isolated patients often present with identity disturbance. Identity, it is argued, develops as a thematic pattern of narcissism, shaped by the nature of the mother's early libidinal influences on the child's sense of self. Identity provides a form of self-definition that addresses the question, Who am I? In the treatment of these patients, resistances to narcissistic vulnerabilities (narcissistic resistances) provide an illusory sense of security and induce the analyst to avoid attention to a central pathological problem: primitive and frightening needs for, and unconscious fantasies of, dependence on, and functionality for, another. Patients' avoidance of material and therapeutic interactions that deal with their dependencies are aspects of a tacit contract with the analyst to foreclose examination of their considerable problems with inner stability. Among these problems are anxieties regarding intrusion and loss of separateness. As analysis proceeds, elements of such a patient's identity become clarified and are used to understand and organize the material for both analyst and patient. This can allow the patient to articulate a more embodied and vital experience of individuality. A case is presented to illustrate the analysis of a patient using this approach.

  17. Visual Disturbances in (Pre)eclampsia

    NARCIS (Netherlands)

    Roos, Nina M.; Wiegman, Marjon J.; Jansonius, Nomdo M.; Zeeman, Gerda G.

    This review aims to summarize existing information concerning visual disturbances in (pre) eclampsia that have been described in the literature. Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortality worldwide. Visual disturbances in (pre) eclampsia seem to be

  18. Physiology of respiratory disturbances in muscular dystrophies

    Directory of Open Access Journals (Sweden)

    Antonella Lo Mauro

    2016-12-01

    To understand the mechanisms leading to respiratory disturbances in patients with muscular dystrophy. To understand the impact of respiratory disturbances in patients with muscular dystrophy. To provide a brief description of the main forms of muscular dystrophy with their respiratory implications.

  19. 36 CFR 2.12 - Audio disturbances.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Audio disturbances. 2.12... RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.12 Audio disturbances. (a) The following are prohibited..., motorized toy, or an audio device, such as a radio, television set, tape deck or musical instrument, in a...

  20. Instrumentation for Power System Disturbance Monitoring, Data ...

    African Journals Online (AJOL)

    In this paper, the level of instrumentation for power system disturbance monitoring, data acquisition and control in Nigerian Electric Power System; National Electric Power Authority (NEPA) is presented. The need for accurate power system disturbance monitoring is highlighted. A feature of an adequate monitoring, data ...

  1. Anthropogenic disturbance on the vegetation in makurunge

    African Journals Online (AJOL)

    Mgina

    ABSTRACT. Makurunge woodland is part of the major vegetation component covering coastal forest landscape in Tanzania that has been severely affected by anthropogenic disturbance. The present study determined the effects of anthropogenic disturbance on biomass, diversity, plant communities and plant species ...

  2. Anthropogenic Disturbance on the Vegetation in Makurunge ...

    African Journals Online (AJOL)

    Makurunge woodland is part of the major vegetation component covering coastal forest landscape in Tanzania that has been severely affected by anthropogenic disturbance. The present study determined the effects of anthropogenic disturbance on biomass, diversity, plant communities and plant species distribution pattern ...

  3. Sleep disturbance and kynurenine metabolism in depression.

    Science.gov (United States)

    Cho, Hyong Jin; Savitz, Jonathan; Dantzer, Robert; Teague, T Kent; Drevets, Wayne C; Irwin, Michael R

    2017-08-01

    Although the interrelationships between sleep disturbance, inflammation, and depression have been found, molecular mechanisms that link these conditions are largely unknown. Kynurenine metabolism is hypothesized to be a key mechanism that links inflammation and depression. Inflammation activates the kynurenine pathway, leading to increases in 3-hydroxykynurenine (3HK) and quinolinic acid (QA), potentially neurotoxic metabolites, and decreases in kynurenic acid (KynA), a potentially neuroprotective compound. This relative neurotoxic shift in the balance of kynurenine metabolites has been associated with depression, but never been examined regarding sleep disturbance. We tested the association between sleep disturbance and this relative neurotoxic shift in 68 currently depressed, 26 previously depressed, and 66 never depressed subjects. Sleep disturbance was assessed using the Pittsburgh Sleep Quality Index. Serum concentrations of kynurenine metabolites were measured using high performance liquid chromatography. Putative neuroprotective indices reflecting the relative activity of neuroprotective and neurotoxic kynurenine metabolites were calculated as KynA/QA and KynA/3HK (primary outcomes). Sleep disturbance was associated with reduced KynA/QA in the currently depressed group only (unadjusted beta -0.43, psleep disturbance and KynA/3HK in any of the groups. Sleep disturbance was associated with increased C-reactive protein in currently depressed subjects only (unadjusted beta 0.38, p=0.007; adjusted beta 0.33, p=0.02). These data support the hypothesis that altered kynurenine metabolism may molecularly link sleep disturbance and depression. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. WHEN THE DISTURBANCES ARE SPATIALLY CORRELATED

    African Journals Online (AJOL)

    variance, in the linear regression model with correlated disturbances, is biased and not consistent in general (see Dhrymes 1978, Chapter 3). This means that when the disturbances are correlated, the standard procedures for testing hypothesis and constructing confidence intervals with respect to the regression. coefficients ...

  5. Disturbing, Disordered or Disturbed? Perspectives on the Definition of Problem Behavior in Educational Settings.

    Science.gov (United States)

    Wood, Frank H., Ed.; Lakin, K. Charlie, Ed.

    The book contains five papers presented at a 1979 topical conference on the definition of emotional disturbance and behavioral disorders in educational settings. The first paper, by F. Wood, is titled "Defining Disturbing, Disordered, and Disturbed Behavior." Topics covered include ambivalence about defining deviant behavior by special educators,…

  6. Hydrological disturbance diminishes predator control in wetlands.

    Science.gov (United States)

    Dorn, Nathan J; Cook, Mark I

    2015-11-01

    Effects of predators on prey populations can be especially strong in aquatic ecosystems, but disturbances may mediate the strength of predator limitation and even allow outbreaks of some prey populations. In a two-year study we investigated the numerical responses of crayfish (Procambarus fallax) and small fishes (Poeciliidae and Fundulidae) to a brief hydrological disturbance in replicated freshwater wetlands with an experimental drying and large predatory fish reduction. The experiment and an in situ predation assay tested the component of the consumer stress model positing that disturbances release prey from predator limitation. In the disturbed wetlands, abundances of large predatory fish were seasonally reduced, similar to dynamics in the Everglades (southern Florida). Densities of small fish were unaffected by the disturbance, but crayfish densities, which were similar across all wetlands before drying, increased almost threefold in the year after the disturbance. Upon re-flooding, juvenile crayfish survival was inversely related to the abundance of large fish across wetlands, but we found no evidence for enhanced algal food quality. At a larger landscape scale (500 km2 of the Everglades), crayfish densities over eight years were positively correlated with the severity of local dry disturbances (up to 99 days dry) during the preceding dry season. In contrast, densities of small-bodied fishes in the same wetlands were seasonally depressed by dry disturbances. The results from our experimental wetland drought and the observations of crayfish densities in the Everglades represent a large-scale example of prey population release following a hydrological disturbance in a freshwater ecosystem. The conditions producing crayfish pulses in the Everglades appear consistent with the mechanics of the consumer stress model, and we suggest crayfish pulses may influence the number of nesting wading birds in the Everglades.

  7. Speech and Language Disturbances in Neurology Practice

    Directory of Open Access Journals (Sweden)

    Oğuz Tanrıdağ

    2009-12-01

    Full Text Available Despite the well-known facts discerned from interesting cases of speech and language disturbances over thousands of years, the scientific background and the limitless discussions for nearly 150 years, this field has been considered one of the least important subjects in neurological sciences. In this review, we first analyze the possible causes for this “stepchild” attitude towards this subject and we then summarize the practical aspects concerning speech and language disturbances. Our underlying expectation with this review is to explain the facts concerning those disturbances that might offer us opportunities to better understand the nervous system and the affected patients

  8. Nocturnal Sleep Disturbances: Risk Factors for Suicide

    Science.gov (United States)

    ... among the elderly (Bernert, 2007) and, mediated by depression, are associated with suicide ideation among the elderly (Nadorff et al., 2013). ... suicidal behavior in the National Longitudinal Study of Adolescent ... (2013) 5 Nocturnal Sleep Disturbances: Risk Factors for ...

  9. Sleep disturbances after non-cardiac surgery

    DEFF Research Database (Denmark)

    Rosenberg, Jacob

    2001-01-01

    After major non-cardiac surgery sleep pattern is usually disturbed with initial suppression of rapid eye movement sleep with a subsequent rebound during the first post-operative week. Deep sleep is also suppressed for several days after the operation and subjective sleep quality is impaired....... The sleep disturbances seem to be related to the magnitude of trauma and thereby to the surgical stress response and/or post-operative opioid administration. Post-operative sleep disturbances may contribute to the development of early post-operative fatigue, episodic hypoxaemia, haemodynamic instability...... and altered mental status, all with a potential negative effect on post-operative outcome. Minimizing surgical trauma and avoiding or minimizing use of opioids for pain relief may prevent or reduce post-operative sleep disturbances. Post-operative sleep pattern represents an important research field, since...

  10. Propagation of a small disturbance in Aorta

    International Nuclear Information System (INIS)

    Gaur, M.; Prakash, R.

    1988-01-01

    The object of the present communication is to provide a mathematical model for the propagation of a small disturbance in the aorta. A differential equation governing the growth and decay of the small disturbance has been obtained. It is observed that the compressive pulses may grow into a shock wave. A mathematical model which is based on geometrical and mechanical properties of aorta admits disturbances in the propagating pulses which are not observed in human beings under normal physiological conditions. It is also observed that friction effects are to resist the tendency of shock formation in the model. The application of the results to the human arterial system shows that strong disturbances or shock waves are not expected under normal physiological conditions, while, in the case of a pathologically increased pressure rise at the root of aorta, shocklike transition may develop in the periphery. Some special cases of interest have also been discussed

  11. Disturbed Fossil Group Galaxy NGC 1132

    Science.gov (United States)

    Kim, Dong-Woo; Anderson, Craig; Burke, Doug; Fabbiano, Giuseppina; Fruscione, Antonella; Lauer, Jen; McCollough, Michael; Morgan, Doug; Mossman, Amy; O’Sullivan, Ewan; Paggi, Alessandro; Vrtilek, Saeqa; Trinchieri, Ginevra

    2018-02-01

    We have analyzed the Chandra archival data of NGC 1132, a well-known fossil group, i.e., a system expected to be old and relaxed long after the giant elliptical galaxy assembly. Instead, the Chandra data reveal that the hot gas morphology is disturbed and asymmetrical, with a cold front following a possible bow shock. We discuss possible origins of the disturbed hot halo, including sloshing by a nearby object, merger, ram pressure by external hotter gas, and nuclear outburst. We consider that the first two mechanisms are likely explanations for the disturbed hot halo, with a slight preference for a minor merger with a low impact parameter because of the match with simulations and previous optical observations. In this case, NGC 1132 may be a rare example of unusual late mergers seen in recent simulations. Regardless of the origin of the disturbed hot halo, the paradigm of the fossil system needs to be reconsidered.

  12. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel mechanical noise is one of the largest sources of disturbance forcing on space-based observatories. Such noise arises from mass imbalance, bearing...

  13. [Recognizing and preventing disturbances in eruption].

    Science.gov (United States)

    van der Linden, F P G M

    2014-04-01

    Disturbances in eruption and related problems are quite common in permanent dentition but rare in deciduous dentition. For the timely recognition of disturbances in eruption, knowledge of the normal development of dentition is essential. Disturbances in eruption comprise disturbances in which eruption does not occur at all, in which it is delayed or incomplete, or in which the normal direction of eruption is influenced. If identified early enough, many undesirable dental conditions can be avoided or their seriousness can be limited. A possible impacting of permanent cuspids, for example, can be avoided by extracting the deciduous cuspids at the right moment; in cases of a large overjet or the threat of a cover-bite, lip interference can be prevented.

  14. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel disturbances are some of the largest sources of noise on sensitive telescopes. Such wheel-induced mechanical noises are not well characterized....

  15. Wind Power Prediction Considering Nonlinear Atmospheric Disturbances

    Directory of Open Access Journals (Sweden)

    Yagang Zhang

    2015-01-01

    Full Text Available This paper considers the effect of nonlinear atmospheric disturbances on wind power prediction. A Lorenz system is introduced as an atmospheric disturbance model. Three new improved wind forecasting models combined with a Lorenz comprehensive disturbance are put forward in this study. Firstly, we define the form of the Lorenz disturbance variable and the wind speed perturbation formula. Then, different artificial neural network models are used to verify the new idea and obtain better wind speed predictions. Finally we separately use the original and improved wind speed series to predict the related wind power. This proves that the corrected wind speed provides higher precision wind power predictions. This research presents a totally new direction in the wind prediction field and has profound theoretical research value and practical guiding significance.

  16. Soil disturbance as a grassland restoration measure

    DEFF Research Database (Denmark)

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success...... target. Species richness and functional diversity both increased in response to soil disturbance, and rotavation, but not ploughing, had a persistent positive effect on the occurrence of specialist species of calcareous sandy grassland. However, no type of soil disturbance caused the plant species...... successful in promoting specialist species in calcareous sandy grassland, but that further treatments are needed to reduce nutrient availability. We conclude that a functional trait based analysis provides additional information of the vegetation response and the abiotic conditions created, complementing...

  17. Sleep, sleep disturbance, and fertility in women.

    Science.gov (United States)

    Kloss, Jacqueline D; Perlis, Michael L; Zamzow, Jessica A; Culnan, Elizabeth J; Gracia, Clarisa R

    2015-08-01

    Sleep and sleep disturbances are increasingly recognized as determinants of women's health and well-being, particularly in the context of the menstrual cycle, pregnancy, and menopause. At present, however, little is known about whether fertility is affected by sleep quantity and quality. That is, to what degree, and by what mechanisms, do sleep and/or its disturbances affect fertility? The purpose of this review is to synthesize what is known about sleep disturbances in relation to reproductive capacity. A model is provided, whereby stress, sleep dysregulation, and circadian misalignment are delineated for their potential relevance to infertility. Ultimately, if it is the case that sleep disturbance is associated with infertility, new avenues for clinical intervention may be possible. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Sleep disturbances and exposure to organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Lindelof, B.; Almkvist, O.; Goethe, C. (Huddinge Hospital (Sweden))

    An inquiry about sleep habits and sleep disturbances revealed a significantly higher prevalence of insomnia in a solvent-exposed group than in a comparable group that had no occupational exposure to organic solvents. The solvent-exposed group has also registered an increased consumption of hypnotics, and a significant increase occurred in the number of individuals who had consulted physicians because of sleep disorders. The results indicate that solvent exposure could induce sleep disturbances.

  19. Eruption disturbances in Japanese children and adolescents

    OpenAIRE

    Noda, Tadashi; Takagi, Masamichi; Hayashi-Sakai, Sachiko; Taguchi, Yo

    2006-01-01

    The aims of this report were to determine the nature of eruption disturbances and to establish the pattern of managment tor these teeth in a group of Japanese children and adolescents. Data were collected trom the clinical records of patients in the Pediatric Dental Clinic of Niigata University Medical and Dental Hospital. There were 700 patients (364 males and 336 femalse) and 748 teeth (26 primary teeth and 722 permanent teeth) who were treated for eruption disturbances between 1979 and 200...

  20. [Sleep disturbances: frequent diagnosis in inpatients].

    Science.gov (United States)

    Bergamasco, Ellen Cristina; da Cruz, Diná de Almeida Lopes Monteiro

    2006-09-01

    Sleep disturbances and deprivation are common stressors in inpatients. Nurses must be able to notice undesirable effects of sleep disturbances on the patient's responses to health problems, and to implement interventions to help them achieve the best possible quality of sleep. This article discusses the relevance of sleep-related nursing diagnoses for inpatients of medical-surgical wards, and presents a synthesis of the tools available in literature to assess sleep.

  1. Sleep disturbance associated factors in menopausal women

    Directory of Open Access Journals (Sweden)

    Hamid Haghani

    2011-09-01

    Full Text Available Background: Sleep is necessary in life and approximately 1/3 of human life is devoted to sleep. One of the most common problems in menopausal women is sleep disturbance. The aim of this study was to determine frequency of sleep disorders and its related factors in 50 – 60 years old women Methods: A cross-sectional, descriptive study was conducted on 200 eligible women who referred to selected health centers of Tehran University of Medical Sciences (TUMS. Demographic form, ten-point slide to review sexual satisfaction and Pittsburg Sleep Quality Index Questioner (PSQI were used for data collection. Data was analyzed using ANOVA, t-test, and Pearson correlation tests.Results: The mean age of women was 53.6±3.6 year, menopause age 47.8±4, number of children 4.76±2 and partner age was 57.99±6.6. 34.5% of women were satisfied from their sexual relationship and their score was 8-10. Rate of sleep disturbances in this group was about 70%. The results showed that between four variables: economical status, occupation, partner occupation and educational status were significantly associated with sleep disturbance (P=0.002. There was not significant difference between other demographic information and sleep disturbance.Conclusion: The results show high prevalence of sleep disturbance symptoms among menopausal women. According to the relationship between some personal characters and sleep disturbance, health care providers need to consider these variables.

  2. Concepts and Challenges in Disturbance Hydrology

    Science.gov (United States)

    Ebel, B. A.; Mirus, B. B.

    2016-12-01

    Landscape disturbances are increasing, often promoted and enhanced by climate shifts and human activities. Insect infestations, wildfires, earthquakes, urban development, forest harvest, mineral and petroleum resource extraction, and hurricanes are common landscape disturbances that can have profound hydrologic consequences. These cause relatively abrupt changes in the landscape, which alter local processes on plots and hillslopes in addition to coarser-scale processes across watersheds through cross-scale interactions. Shifts in soil properties and cover of vegetation and leaf litter change the water storage or buffering capacity as well as the hydrologic functional connectivity across multiple scales. These changes increase the risk of catastrophic flooding, erosion, and mass movements that degrade water resources, ecosystem services, and protection from hydrologically driven natural hazards. Although it is imperative that we understand the hydrologic effects of these disturbances, several major barriers exist. Four challenges are: (i) overlapping disturbances in space and time with unknown recovery trajectories, (ii) a paucity of long-term recovery records (>5 years duration), (iii) inefficacy of traditional modeling and parameterization approaches, and (iv) lack of pre-disturbance characterization. Examples of these challenges will be presented along with proposed opportunities for improved mechanistic understanding of processes and thresholds in disturbance hydrology.

  3. Structural Decoupling and Disturbance Rejection in a Distillation Column

    DEFF Research Database (Denmark)

    Bahar, Mehrdad; Jantzen, Jan; Commault, C.

    1996-01-01

    Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references.......Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references....

  4. Active disturbance rejection controller for chemical reactor

    International Nuclear Information System (INIS)

    Both, Roxana; Dulf, Eva H.; Muresan, Cristina I.

    2015-01-01

    In the petrochemical industry, the synthesis of 2 ethyl-hexanol-oxo-alcohols (plasticizers alcohol) is of high importance, being achieved through hydrogenation of 2 ethyl-hexenal inside catalytic trickle bed three-phase reactors. For this type of processes the use of advanced control strategies is suitable due to their nonlinear behavior and extreme sensitivity to load changes and other disturbances. Due to the complexity of the mathematical model an approach was to use a simple linear model of the process in combination with an advanced control algorithm which takes into account the model uncertainties, the disturbances and command signal limitations like robust control. However the resulting controller is complex, involving cost effective hardware. This paper proposes a simple integer-order control scheme using a linear model of the process, based on active disturbance rejection method. By treating the model dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. Simulation results are provided to demonstrate the effectiveness of the proposed method

  5. Presleep arousal and sleep disturbances in children.

    Science.gov (United States)

    Gregory, Alice M; Willis, Thomas A; Wiggs, Luci; Harvey, Allison G

    2008-12-01

    To determine if associations between presleep arousal and sleep disturbance reported in adults are also characteristic of children. Linear regression analyses examined whether somatic and cognitive presleep arousal predicted sleep disturbances. Two inner city schools, London, U.K. One hundred twenty-three children aged 8 to 10 years, 49% boys, from ethnically diverse backgrounds. N/A. Children completed the Sleep Self-Report and the Pre-sleep Arousal Scale (comprising somatic and cognitive subscales). Parents completed the Child Sleep Habits Questionnaire. In separate models, both somatic (beta = 0.44, P Sleep Self-Report total score. Somatic (beta = 0.28, P Sleep Self-Report insomnia items in separate models. These results were partially replicated when using the parent report of the Child Sleep Habits Questionnaire. When somatic and cognitive items were included in the same models, cognitive but not somatic arousal significantly predicted (most definitions of) sleep disturbance. Cognitive, and to a lesser extent somatic, presleep arousal appears to be associated with sleep disturbances in children. This suggests that further research into cognitive aspects of sleep disturbance in children is warranted-as incorporating this information into treatments may eventually prove fruitful.

  6. Language disturbances from mesencephalo-thalamic infarcts

    International Nuclear Information System (INIS)

    Lazzarino, L.G.; Nicolai, A.; Valassi, F.; Biasizzo, E.

    1991-01-01

    The authors report the cases of two patients with CT-documented paramedian mesencephalo-thalamic infarcts, showing language disturbances. The first patient showed a non fluent, transcortical motor-like aphasia, the other had a fluent but severely paraphasic language disorder. The CT study disclosed that it was the dorso-median thalamic nucleus that was mostly involved in both cases. These findings agree with a few previous pathological studies suggesting that the paramedian thalamic nuclei, particlularly the dorso-median nucleus may play some role in language disturbances. However the anatomical basis for thalamic aphasia remains speculative, taking into account the importantce of cortical connections in the origin of subcortical neuropsychological disturbances. (orig.)

  7. Psychopathology and hormonal disturbances in eating disorders

    Directory of Open Access Journals (Sweden)

    Pierpaola D’Arista

    2008-09-01

    Full Text Available

    Background: Our aim was to study the relationship between hormonal disturbances and psychopathology in Eating Disorders (ED.

    Methods: Forty-nine women diagnosed as Eating Disorders according to DSM-IV were subjected to control plasma levels of TSH, FT3, FT4, LH, FSH, 17beta-estradiol, prolactin, cortisol, DHEAS, GH and IGF-1. They were also administered by SCL-90R, BAT, DES II questionnaires. We applied multivariate regression models.

    Results: Our results highlight a statistically significant relation between LH, FSH and prolactin decreased levels, mood and thought disturbances (subscales 3, 5, 7, 8 and 9 of SCL-90r which are associated to Body Attitude ( BAT total scale and Dissociative Experiences (DES II total scale.

    Conclusions: Decreased sexual hormones levels could have a role in ED psychological disturbances, not inquired yet

  8. Work Time Control and Sleep Disturbances

    DEFF Research Database (Denmark)

    Salo, Paula; Ala-Mursula, Leena; Rod, Naja Hulvej

    2014-01-01

    OBJECTIVES: Employee control over work times has been associated with favorable psychosocial and health-related outcomes, but the evidence regarding sleep quality remains inconclusive. We examined cross-sectional and prospective associations between work time control and sleep disturbances...... in a large working population, taking into account total hours worked. METHODS: The data were from a full-panel longitudinal cohort study of Finnish public sector employees who responded to questions on work time control and sleep disturbances in years 2000-2001, 2004-2005, 2008-2009, and 2012. The analysis....... RESULTS: Consistently in both cross-sectional and longitudinal models, less control over work time was associated with greater sleep disturbances in the total population and among those working normal 40-hour weeks. Among participants working more than 40 hours a week, work time that was both very high...

  9. Diagnostic orientation in control of disturbance situations

    International Nuclear Information System (INIS)

    Hukki, K.; Norros, L.

    1993-01-01

    The object of the study is diagnostic judgement in the control of dynamic processes. The starting point was the known difficulty process operators have in utilizing knowledge of process dynamics in disturbance situations that require both diagnostic and prognostic actions. A model of the diagnostic judgement process as a construction of coherent interpretation of the situation is outlined, and comprehensive data from simulated disturbance handling by 6 crews of a PWR type nuclear power plant was analysed. The phase of analysis included evaluation of the adequacy of task performance, utilization of available process information, and evaluation of the interpretation of disturbance situations. The results suggest that a functional orientation towards task performance allows a more coherent and comprehensive interpretation of the situation and more adequate task performance. Coherence of interpretation seems to be reflected in a higher subjective certainty compared with crews with an incoherent interpretation. (author). 15 refs, 2 figs, 2 tabs

  10. Robust fuzzy logic stabilization with disturbance elimination.

    Science.gov (United States)

    Danapalasingam, Kumeresan A

    2014-01-01

    A robust fuzzy logic controller is proposed for stabilization and disturbance rejection in nonlinear control systems of a particular type. The dynamic feedback controller is designed as a combination of a control law that compensates for nonlinear terms in a control system and a dynamic fuzzy logic controller that addresses unknown model uncertainties and an unmeasured disturbance. Since it is challenging to derive a highly accurate mathematical model, the proposed controller requires only nominal functions of a control system. In this paper, a mathematical derivation is carried out to prove that the controller is able to achieve asymptotic stability by processing state measurements. Robustness here refers to the ability of the controller to asymptotically steer the state vector towards the origin in the presence of model uncertainties and a disturbance input. Simulation results of the robust fuzzy logic controller application in a magnetic levitation system demonstrate the feasibility of the control design.

  11. Ionospheric irregularities in periods of meteorological disturbances

    Science.gov (United States)

    Borchevkina, O. P.; Karpov, I. V.

    2017-09-01

    The results of observations of the total electron content (TEC) in periods of storm disturbances of meteorological situation are presented in the paper. The observational results have shown that a passage of a meteorological storm is accompanied by a substantial decrease in values of TEC and critical frequencies of the ionospheric F2 region. The decreases in values of these ionospheric parameters reach 50% and up to 30% in TEC and critical frequency of the F2 layer, respectively, as compared to meteorologically quiet days. Based on qualitative analysis, it is found that the processes related to formation of local regions of thermospheric heating due to a dissipation of AGW coming into the upper atmosphere from the region of the meteorological disturbance in the lower atmosphere are a possible cause of these ionospheric disturbances.

  12. Propagation of solar disturbances - Theories and models

    Science.gov (United States)

    Wu, S. T.

    1983-01-01

    Recent theoretical developments and construction of several models for the propagation of solar disturbances from the sun and their continuation throughout heliospheric space are discussed. Emphasis centers on physical mechanisms as well as mathematical techniques (i.e., analytical and numerical methods). This outline will lead to a discussion of the state-of-the-art of theoretically based modeling efforts in this area. It is shown that the fundamental theory for the study of propagation of disturbances in heliospheric space is centered around the self-consistent analysis of wave and mass motion within the context of magnetohydrodynamics in which the small scale structures will be modified by kinetic effects. Finally, brief mention is made of some interesting problems for which attention is needed for advancement of the understanding of the physics of large scale propagation of solar disturbances in heliospheric space.

  13. Geomagnetic Disturbances Caused by Internal Atmospheric Dynamics

    Science.gov (United States)

    Sonneman, G.

    1984-01-01

    It is commonly believed that geomagnetic disturbances are caused by external influences connected with the solar wind. The 27-day recurrence of perturbations seems to be a strong hint for this interaction. But frequently geomagnetic disturbances occur without any relation to sunspot numbers or radiowave fluxes. This was one of the reasons for introducing hypothetical M-regions on the Sun and their relation to solar wind activities. Only one half of the variance of the geomagnetic AL-index could be related to the solar wind. Therefore it is concluded that internal processes of the magnetosphere were responsible for additional geomagnetic activity. Arguments, which might lead to the suggestion of geomagnetic disturbances as being caused by internal atmospheric dynamics are discussed and a rather preliminary scenario of those processes is proposed.

  14. Atopic dermatitis, melatonin, and sleep disturbance.

    Science.gov (United States)

    Chang, Yung-Sen; Chou, Yen-Ting; Lee, Jyh-Hong; Lee, Pei-Lin; Dai, Yang-Shia; Sun, Chi; Lin, Yu-Tsan; Wang, Li-Chieh; Yu, Hsin-Hui; Yang, Yao-Hsu; Chen, Chun-An; Wan, Kong-Sang; Chiang, Bor-Luen

    2014-08-01

    Sleep disturbance is common in patients with atopic dermatitis (AD). However, studies have largely been questionnaire-based, and the pathophysiology remains unclear. The aims of this study were to determine objective characteristics of sleep disturbance in children with AD and explore contributing factors and clinical predictors. Sleep parameters were measured by actigraphy and polysomnography in 72 patients with AD and 32 controls ages 1 to 18 years. Urinary 6-sulfatoxymelatonin levels, serum cytokines, and total and allergen-specific immunoglobulin E (IgE) levels were also measured. The patients with AD had significantly reduced sleep efficiency, longer sleep onset latency, more sleep fragmentation, and less nonrapid eye movement sleep. Results from actigraphy correlated well with those from polysomnography. The AD disease severity was associated with sleep disturbance (r = 0.55-0.7), and a Scoring Atopic Dermatitis index of ≥48.7 predicted poor sleep efficiency with a sensitivity of 83.3% and a specificity of 75% (area under the curve = 0.81, P = .001). Lower nocturnal melatonin secretion was significantly associated with sleep disturbance in the patients with AD. Other correlates of sleep disturbance included pruritus, scratching movements, higher total serum IgE levels, and allergic sensitization to dust mite and staphylococcal enterotoxins. Poor sleep efficiency is common in children with AD and can be predicted by the Scoring Atopic Dermatitis index. Melatonin and IgE might play a role in the sleep disturbance. Further studies are required to explore the mechanisms and clinical implications, and actigraphy could serve as a useful evaluating tool. Copyright © 2014 by the American Academy of Pediatrics.

  15. Changing Forest Disturbance Regimes and Risk Perceptions in Homer, Alaska

    Science.gov (United States)

    Courtney G. F1int

    2007-01-01

    Forest disturbances caused by insects can lead to other disturbances, risks, and changes across landscapes. Evaluating the human dimensions of such disturbances furthers understanding of integrated changes in natural and social systems. This article examines the effects of changing forest disturbance regimes on local risk perceptions and attitudes in Homer, Alaska....

  16. Disturbance ecology and forest management: A review of the literature

    Science.gov (United States)

    Paul Rogers

    1996-01-01

    This review of the disturbance ecology literature, and how it pertains to forest management, is a resource for forest managers and researchers interested in disturbance theory, specific disturbance agents, their interactions, and appropriate methods of inquiry for specific geographic regions. Implications for the future of disturbance ecology-based management are...

  17. North American forest disturbance mapped from a decadal Landsat record

    Science.gov (United States)

    Jeffrey G. Masek; Chengquan Huang; Robert Wolfe; Warren Cohen; Forrest Hall; Jonathan Kutler; Peder. Nelson

    2008-01-01

    Forest disturbance and recovery are critical ecosystem processes, but the spatial pattern of disturbance has never been mapped across North America. The LEDAPS (Landsat Ecosystem Disturbance Adaptive Processing System) project has assembled a wall-to-wall record of stand-clearing disturbance (clearcut harvest, fire) for the United States and Canada for the period 1990-...

  18. Disturbances in reaction wheels; from measurement to modelling

    NARCIS (Netherlands)

    Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

    2014-01-01

    Disturbances in reaction wheels have been long a crucial aspect for many scientific observation missions. An accurate and reliable disturbance model to understand and evaluate the influence of reaction wheel disturbances to the spacecraft is critically needed. Several reaction wheel disturbance

  19. Age structure and disturbance legacy of North American forests

    Science.gov (United States)

    Y. Pan; J.M. Chen; R. Birdsey; K. McCullough; L. He; F. Deng

    2011-01-01

    Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stocks and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a...

  20. Sudden ionospheric disturbances in solar cycle 24

    Science.gov (United States)

    Bothmer, Volker; Bernert, Barbara

    2014-05-01

    Sudden ionospheric disturbances in solar cycle 24 Within the framework of the UN International Space Weather Initiative, and building upon the achievements of the International Heliophysical Year, the German project SIMONE (Sun Ionosphere MOnitoring NEtwork) operates several SID monitors provided by the University of Stanford. Here we present an overview of sudden ionospheric disturbances recorded since 2006 at the high school Gymnasium Walsrode until to date. The continous measurements allow a detailed comparison of locally measured SIDs with the general trend of solar activity during the current solar maximum. We further show that the measurements reveal specific information on the variable response of the dayside ionosphere to solar flares.

  1. Voriconazole-associated visual disturbances and hallucinations.

    Science.gov (United States)

    Bayhan, Gulsum Iclal; Garipardic, Mesut; Karaman, Kamuran; Akbayram, Sinan

    2016-03-01

    Voriconazole is a second-generation azole widely used for the prevention and treatment of fungal infection in leukemia patients. Voriconazole is considered the primary antifungal agent for invasive aspergillosis. We report a case of 16-year-old girl who developed visual disturbance and visual and auditory hallucinations after intravenous voriconazole treatment for invasive pulmonary aspergillosis. Due to the visual hallucinations and visual disturbance began acutely and shortly after the initiation of voriconazole, and no other cause could be determined, the symptoms were considered to be the side effects of voriconazole. Simultaneous development of visual side effects and hallucinations rarely have been reported before.

  2. PID control with robust disturbance feedback control

    DEFF Research Database (Denmark)

    Kawai, Fukiko; Vinther, Kasper; Andersen, Palle

    2015-01-01

    Disturbance Feedback Control (DFC) is a technique, originally proposed by Fuji Electric, for augmenting existing control systems with an extra feedback for attenuation of disturbances and model errors. In this work, we analyze the robustness and performance of a PID-based control system with DFC...... and performance (if such gains exist). Finally, two different simulation case studies are evaluated and compared. Our numerical studies indicate that better performance can be achieved with the proposed method compared with a conservatively tuned PID controller and comparable performance can be achieved when...... compared with an H-infinity controller....

  3. Nonunity gain minimal-disturbance measurement

    DEFF Research Database (Denmark)

    Sabuncu, Metin; Mišta, L.; Fiurášek, J.

    2007-01-01

    We propose and experimentally demonstrate an optimal nonunity gain Gaussian scheme for partial measurement of an unknown coherent state that causes minimal disturbance of the state. The information gain and the state disturbance are quantified by the noise added to the measurement outcomes and to...... and to the output state, respectively. We derive the optimal trade-off relation between the two noises and we show that the tradeoff is saturated by nonunity gain teleportation. Optimal partial measurement is demonstrated experimentally using a linear optics scheme with feedforward....

  4. Sleep Disturbance in Posttraumatic Stress Disorder: Epiphenomenon or Causal Factor?

    Science.gov (United States)

    Cox, Rebecca C; Tuck, Breanna M; Olatunji, Bunmi O

    2017-04-01

    The goal of this review is to integrate recent findings on sleep disturbance and PTSD, examine sleep disturbance as a causal factor in the development of PTSD, and identify future directions for research, treatment, and prevention. Recent research highlights a relationship between both objective and subjective sleep disturbance and PTSD across diverse samples. Sleep disturbance also predicts PTSD over time. Finally, treatments targeting sleep disturbance lead to decreased PTSD symptoms, while standard PTSD treatments conclude with residual sleep disturbance. Sleep disturbance may be more than a mere epiphenomenon of PTSD. Future research examining the causal role of sleep disturbance in the development of PTSD, as well as the utility of targeting sleep disturbance in prevention and treatment, is necessary to fully understand the likely bidirectional relationship between sleep disturbance and PTSD.

  5. Does acute TBI-related sleep disturbance predict subsequent neuropsychiatric disturbances?

    Science.gov (United States)

    Rao, Vani; McCann, Una; Han, Dingfen; Bergey, Alyssa; Smith, Michael T

    2014-01-01

    To determine whether sleep disturbance in the acute post-traumatic brain injury (TBI) period predicts symptoms of depression, anxiety or apathy measured 6 and 12 months after TBI. Longitudinal, observational study. First time closed-head injury patients (n = 101) were recruited and evaluated within 3 months of injury and followed longitudinally, with psychiatric evaluations at 6 and 12 months post-injury. Pre- and post-injury sleep disturbances were measured via the Medical Outcome Scale (MOS) for Sleep. Subjects were also assessed for anxiety, depression, apathy, medical comorbidity and severity of TBI. Sleep disturbance in the acute TBI period was associated with increased symptoms of depression, anxiety and apathy 12 months post-injury. Sleep disturbances experienced soon after trauma (i.e. <3 months after injury) predicted neuropsychiatric symptoms 1 year after injury, raising two important clinical questions: (1) Is sleep disturbance soon after trauma a prognostic marker of subsequent neuropsychiatric symptoms? and (2) Can early treatment of sleep disturbance during the post-TBI period reduce subsequent development of neuropsychiatric symptoms? Future studies with larger sample sizes and appropriate control groups could help to answer these questions, using evidence-based methods for evaluating and treating sleep disturbances.

  6. Personality Disturbances Associated with Traumatic Brain Injury.

    Science.gov (United States)

    Prigatano, George P.

    1992-01-01

    Reviews personality disturbances associated with traumatic brain injury. Attempts to clarify terms and review empirical findings. Notes that longitudinal prospective studies that use appropriate control groups are needed. Suggests future research may benefit by considering long-term effects of early agitation following traumatic brain injury and…

  7. Solar Development on Contaminated and Disturbed Lands

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lee, Courtney [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mosey, Gail [National Renewable Energy Lab. (NREL), Golden, CO (United States); Melius, Jenny [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-12-01

    Land classified as contaminated and disturbed across the United States has the potential to host developments of utility-scale solar power. This report examines the prospect of developing utility- and commercial-scale concentrated solar power (CSP) and solar photovoltaics (PV) technologies on degraded and environmentally contaminated lands. The potential for solar development on contaminated anddisturbed lands was assessed, and for the largest and highest solar resource sites, the economic impacts and feasibility were evaluated. Developing solar power on contaminated and disturbed lands can help create jobs and revitalize local and state economies, and selecting these sites over greenfield sites can potentially have permitting and environmental mitigation advantages. The U.S.Department of Energy (DOE) SunShot goals call for 632 GW of PV and 83 GW of CSP to be deployed by 2050. Conservative land-use estimates of this study (10 acres per megawatt) show that there are disturbed and environmentally contaminated lands throughout the country that could be suitable for utility-scale solar power, and, that there is sufficient land area to meet SunShot solar deployment goals. The purpose of this assessment is to improve the understanding of these sites and facilitate solar developers' selection of contaminated and disturbed sites for development.

  8. Emotional Disturbance. NICHCY Disability Fact Sheet #5

    Science.gov (United States)

    National Dissemination Center for Children with Disabilities, 2010

    2010-01-01

    The mental health of our children is a natural and important concern for us all. The fact is, many mental disorders have their beginnings in childhood or adolescence, yet may go undiagnosed and untreated for years. "Umbrella" terms such as emotional disturbance, behavioral disorders, or mental illness are used to refer to mental…

  9. Types and Treatment of Pediatric Sleep Disturbances

    Science.gov (United States)

    Hamilton, Gloria J.

    2009-01-01

    This article provides an overview of pediatric sleep disturbances with emphases on types and treatments. Relationships between sleep disorders and comorbid conditions function to exacerbate and maintain both disorders. An estimated 20% of teenagers experience chronic partial sleep deprivation, resulting in problems with memory, attention, and…

  10. Disturbing Practices: Training Workers to Be Lean

    Science.gov (United States)

    Yasukawa, Keiko; Brown, Tony; Black, Stephen

    2014-01-01

    Purpose: The purpose of this paper is to explore the possibilities for expansive learning during organisational change. It considers the introduction of "lean production" as a disturbance to the existing work practices. Design/methodology/approach: The paper considers two case studies of "lean production" training with…

  11. Effectiveness of carnosine on disturbed electrolytes homeostasis ...

    African Journals Online (AJOL)

    We aimed to assess the effect of well known antioxidant carnosine on disturbed plasma and intraerythrocytes electrolytes and Na+-K+-ATPase activity by cisplatin. 24 male albino Wistar rats were selected and divided into 4 groups: Group I = untreated control; Group II = cisplatin control (received cisplatin at a dose of 3 mg/ ...

  12. Alerts of forest disturbance from MODIS imagery

    Science.gov (United States)

    Hammer, Dan; Kraft, Robin; Wheeler, David

    2014-12-01

    This paper reports the methodology and computational strategy for a forest cover disturbance alerting system. Analytical techniques from time series econometrics are applied to imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to detect temporal instability in vegetation indices. The characteristics from each MODIS pixel's spectral history are extracted and compared against historical data on forest cover loss to develop a geographically localized classification rule that can be applied across the humid tropical biome. The final output is a probability of forest disturbance for each 500 m pixel that is updated every 16 days. The primary objective is to provide high-confidence alerts of forest disturbance, while minimizing false positives. We find that the alerts serve this purpose exceedingly well in Pará, Brazil, with high probability alerts garnering a user accuracy of 98 percent over the training period and 93 percent after the training period (2000-2005) when compared against the PRODES deforestation data set, which is used to assess spatial accuracy. Implemented in Clojure and Java on the Hadoop distributed data processing platform, the algorithm is a fast, automated, and open source system for detecting forest disturbance. It is intended to be used in conjunction with higher-resolution imagery and data products that cannot be updated as quickly as MODIS-based data products. By highlighting hotspots of change, the algorithm and associated output can focus high-resolution data acquisition and aid in efforts to enforce local forest conservation efforts.

  13. Body representation disturbances in anorexia nervosa

    NARCIS (Netherlands)

    Keizer, A.

    2014-01-01

    One of the main symptoms of anorexia nervosa (AN) is a disturbed experience of body size and shape. Although patients are underweight, they experience their body as bigger than it in reality is. Previous studies were mainly conducted by (clinical) psychologists and psychiatrists, and almost

  14. Prevalence Of Sleep Disturbances Among Primary Informal ...

    African Journals Online (AJOL)

    Conclusion: Caregivers are at almost thrice the risk of sleep disturbances than the noncaregivers (OR = 2.7, CI= 1.26-1.74). Periodic screening of caregivers should be done with specific sleep instruments especially for those of them who operate dangerous machinery and commercial vehicles. Keywords: Prevalence, Sleep ...

  15. Visuospatial Attention Disturbance in Duchenne Muscular Dystrophy

    Science.gov (United States)

    De Moura, Maria Clara Drummond Soares; do Valle, Luiz Eduardo Ribeiro; Resende, Maria Bernadete Dutra; Pinto, Katia Osternack

    2010-01-01

    Aim: The cognitive deficits present in the Duchenne muscular dystrophy (DMD) are not yet well characterized. Attention, considered to be the brain mechanism responsible for the selection of sensory stimuli, could be disturbed in DMD, contributing, at least partially, to the observed global cognitive deficit. The aim of this study was to…

  16. Monitoring of environmental disturbance using abundance and ...

    African Journals Online (AJOL)

    ... most disturbed site. The pattern of distribution of this species revealed that Akure Forest Reserve is degenerating, a situation that could lead to loss of biodiversity if urgent conservative measures were not put in place. Keywords: Odonata; Trithemis spp; Akure Forest Reserve; diversity indices; Dragonfly; Biotic Index (DBD) ...

  17. Solar and Interplanetary Disturbances causing Moderate ...

    Indian Academy of Sciences (India)

    Abstract. The effect of solar and interplanetary disturbances on geo- magnetospheric conditions leading to 121 moderate geomagnetic storms. (MGS) have been investigated using the neutron monitor, solar geophysical and interplanetary data during the period 1978–99. Further, the duration of recovery phase has been ...

  18. Update on endocrine disturbances in anorexia nervosa

    DEFF Research Database (Denmark)

    Støving, R K; Hangaard, J; Hagen, C

    2001-01-01

    The marked endocrine changes that occur in anorexia nervosa have aroused a great deal of interest, and over the last decade much research has been conducted in this field. The endocrine disturbances are not specific to this disorder, as they also occur in starvation states secondary to other causes...

  19. Evaluation of benthic macroinvertebrate assemblage for disturbance ...

    Indian Academy of Sciences (India)

    different disturbance zones and identifying environmental variables and stressors that deteriorate the river ecosystem. In total, 20 sites in 36-km ... of surface water, various assessment programmes have been launched throughout these ... the United States and Great Britain, biological data are a worthwhile addition to ...

  20. Evaluation of benthic macroinvertebrate assemblage for disturbance ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 122; Issue 4. Evaluation of benthic macroinvertebrate assemblage for disturbance zonation in urban rivers using multivariate analysis: Implications for river management. Ram Devi Tachamo Shah Deep Narayan Shah. Volume 122 Issue 4 August 2013 pp 1125- ...

  1. Solar and Interplanetary Disturbances causing Moderate ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Keywords. Solar flares; active prominences and disappearing filaments; sunspot numbers; geomagnetic storms. Abstract. The effect of solar and interplanetary disturbances on geomagnetospheric conditions leading to 121 moderate geomagnetic storms (MGS) have been investigated using the neutron ...

  2. Conical shell edge disturbance : An engineer's derivation

    NARCIS (Netherlands)

    Blaauwendraad, J.; Hoefakker, JH

    2016-01-01

    Because a rigorous bending theory for thin shells of revolution is complicated, attempts have been made for reliable approximations of the edge disturbance problem under axisymmetric loading. A well-known one was published by Geckeler [1, 2], who obtained his approximation by mathematical

  3. Combine material against electromagnetic pulse disturbance

    International Nuclear Information System (INIS)

    Liu Yan

    2004-01-01

    A novel combined material is introduced, which is hard against electromagnetic pulse disturbance, The attenuation characteristics and the penetration probability of the combine material is discussed in detail. The penetration probability of electromagnetic wave is calculated approximately and the characteristic curve is measured for this material. (authors)

  4. Role of Sleep Disturbance in the Trajectory of Alzheimer's Disease.

    Science.gov (United States)

    Kang, Dong Woo; Lee, Chang Uk; Lim, Hyun Kook

    2017-05-31

    Sleep disturbances such as insomnia, hypersomnia, and circadian rhythm disturbance are common in normal elderly and Alzheimer's disease (AD) patients. To date, special attention has been paid to sleep disturbance in the clinical course of AD insofar as the interaction of sleep disturbance with the pathogenesis of AD may impact the clinical course and cognitive function of AD patients. This review covers the bidirectional relationship between sleep disturbance and AD pathogenesis; the associations between sleep disturbance and AD-specific neurotransmitters, brain structure, and aspects of sleep disturbance in each phase of AD; and the effects of sleep disturbance on the cognitive functions of patients in each phase of AD. We consider several factors required to exactly interpret the results and suggest a direction for future studies on the role of sleep disturbance in AD.

  5. An artificial intelligence approach towards disturbance analysis

    International Nuclear Information System (INIS)

    Fiedler, U.; Lindner, A.; Baldeweg, F.; Klebau, J.

    1986-01-01

    Scale and degree of sophistication of technological plants, e.g. nuclear power plants, have been essentially increased during the last decades. Conventional disturbance analysis systems have proved to work successfully in well-known situations. But in cases of emergencies, the operator needs more advanced assistance in realizing diagnosis and therapy control. The significance of introducing artificial intelligence (AI) methods in nuclear power technology is emphasized. Main features of the on-line disturbance analysis system SAAP-2 are reported about. It is being developed for application to nuclear power plants. Problems related to man-machine communication will be gone into more detail, because their solution will influence end-user acceptance considerably. (author)

  6. Reaction Wheel Disturbance Model Extraction Software - RWDMES

    Science.gov (United States)

    Blaurock, Carl

    2009-01-01

    The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral

  7. Memory and learning disturbances in multiple sclerosis

    International Nuclear Information System (INIS)

    Izquierdo, Guillermo; Mir, Jordi; Gonzalez, Manuel; Martinez-Parra, Carlos; Campoy, Francisco Jr

    1991-01-01

    Thirty-five patients with definite multiple sclerosis (MS) were studied. They underwent neuropsychological testing and magnetic resonance imaging (MRI). The MRI findings at different brain areas levels were compared with the neuropsychological findings. A quantitative system was used to measure MRI-MS lesions. In this series, a positive correlation was established between memory and learning disturbances measured by Battery 144, and the lesions measured by MRI (total, hemispheric and , particularly, periventricular lesions). MRI can detect MS lesions, and this study shows that a correlation between MRI and neuropsychological findings is possible if quantitative methods are used to distinguish different MS involvement areas in relation to neuropsychological tasks. These findings suggest that hemispheric lesions in MS produce cognitive disturbances and MRI could be a useful tool in predicting memory and learning impairment. (author). 20 refs.; 1 fig.; 2 tabs

  8. Parkinson's Disease and Sleep/Wake Disturbances

    Directory of Open Access Journals (Sweden)

    Todd J. Swick

    2012-01-01

    Full Text Available Parkinson's disease (PD has traditionally been characterized by its cardinal motor symptoms of bradykinesia, rigidity, resting tremor, and postural instability. However, PD is increasingly being recognized as a multidimensional disease associated with myriad nonmotor symptoms including autonomic dysfunction, mood disorders, cognitive impairment, pain, gastrointestinal disturbance, impaired olfaction, psychosis, and sleep disorders. Sleep disturbances, which include sleep fragmentation, daytime somnolence, sleep-disordered breathing, restless legs syndrome (RLS, nightmares, and rapid eye movement (REM sleep behavior disorder (RBD, are estimated to occur in 60% to 98% of patients with PD. For years nonmotor symptoms received little attention from clinicians and researchers, but now these symptoms are known to be significant predictors of morbidity in determining quality of life, costs of disease, and rates of institutionalization. A discussion of the clinical aspects, pathophysiology, evaluation techniques, and treatment options for the sleep disorders that are encountered with PD is presented.

  9. Modeling of atmospheric disturbances in meteorological pictures.

    Science.gov (United States)

    Bouthemy, P; Benveniste, A

    1984-05-01

    This paper describes a model-based approach to perform tracking of extratropical atmospheric disturbances from a sequence of satellite cloud-cover images. More precisely, it deals with the estimation of motion of these spiral-shaped cloud systems (both translational and rotational motion), and the measurement of the evolution of their shape. Tracking is achieved by recording from one image to the next the changes of the model parameter values. A maximum likelihood criterion is used in the process of fitting model to sensed data. The defined model takes into account geometric and intensity aspects. Such an approach readily yields global information on the disturbance cloud system of interest. As a requirement in such an application is robustness to noise, to this end two versions of the modeling have been considered.

  10. [Neuroendocrine disturbances after acquired brain damage].

    Science.gov (United States)

    Kreitschmann-Andermahr, I; Brabant, G

    2011-04-01

    Hypopituitarism is not a rare disease and its clinical signs and symptoms deserve the attention of the clinically practising neurologist. Next to the classical cause of hypopituitarism mediated by tumours of the hypothalamo-pituitary region, a number of recent articles have highlighted the high frequency of central endocrine disturbances in patients with brain damage, i. e. not only after traumatic brain injury and subarachnoid haemorrhage but also as a consequence of the treatment of childhood brain tumours. This article provides an overview of the clinical symptomatology and pathophysiology of hypopituitarism as well as the current knowledge about neuroendocrine disturbances in the adult patient suffering from the above-mentioned disorders. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Sleep disturbances in restless legs syndrome

    Directory of Open Access Journals (Sweden)

    Jović Jasmina

    2018-01-01

    Full Text Available Background/Aim. Resteless legs syndrome (RLS is chronical neurological disorder characterized by urge to move legs that is usually accompanied by unpleasant sensations in the lower extremities. Sleep disturbance is one of the main accompanying symptoms of RLS which exists in approximatelly 90% of patients. Impairment of sleep is related to daily sleepiness, depressive and anxiety disorders. The aim of this study was to detect frequency and characterisitics of sleep-related symptoms in patients with RLS, and its impairrment to daily sleepiness, fatique, anxiety and depression. Methods. We have examinated 94 patients with RLS. The diagnose of RLS was based on questionnaire with 4 specific questions according to the International Restless Legs Syndrome Study Group (IRLSSG criteria updated in 2003. Severity of symptoms was astimated with IRLSSG Rating Scale, depression and anxiety with Hamilton Depression Rating Scale (HDRS and Hamilton Anxiety Rating Scale (HARS and sleepiness with Epworth Sleepiness scale (ESS. We astimated sleep characteristics and disturbances with specific questionnaire. Results. In our study 79.9% of patients had sleep-related symptoms. Average sleep duration was 6.50 ± 1.42 hours, with average frequency of awakening 2.34 ± 1.69 times per night. Average ESS score was 5.12 ± 4.08 (0–17. Patients with more severe symptoms had higher degree of sleepiness (p = 0.005. Patients with higher symptoms frequency, significantly more often had sleep disturbance (p = 0.016, tiredness and daily sleepiness (p = 0.001. Daily sleepiness (ESS also significantly correlates with depression (p < 0.05 and anxiety (p = 0.012. Conclusion. Our results confirm that sleep disturbances are one of the key accompanying symptoms of RLS which cause daily sleepiness, tiredness, depression and anxiety. Therefore, their early recognition and appropriate treatment must be a priority in RLS patients.

  12. Electric Utility Industry Experience with Geomagnetic Disturbances

    Science.gov (United States)

    1991-09-01

    calculate the GICs for a large network consisting of 385 nodes on the Minnesota Power System." T’,e Electromagnetic Transients Program ( EMTP ) has also...accelerate the transformer saturation process in the EMTP program without modifying the steady-state results, making digital simulation of GIC effects...possible with EMTP . T’., computer program was used to simulate the power system disturbance that occurred on the James Bay Network during the geomagnetic

  13. Sleep disturbances in myotonic dystrophy type 2

    OpenAIRE

    Shepard, Paul; Lam, Erek M.; St. Louis, Erik K.; Dominik, Jacob

    2012-01-01

    Sleep disorders in myotonic dystrophy type 1 (DM1) are common and include sleep disordered breathing (SDB), hypersomnia, and fatigue. Little is known regarding the occurrence of sleep disturbance in myotonic dystrophy type 2 (DM2). We hypothesized that DM2 patients may frequently harbor sleep disorders. We reviewed medical records of all genetically confirmed cases of DM2 seen at our sleep center between 1997 and 2010 for demographic, laboratory, overnight oximetry, and polysomnography (PSG) ...

  14. Update on endocrine disturbances in anorexia nervosa

    DEFF Research Database (Denmark)

    Støving, R K; Hangaard, J; Hagen, C

    2001-01-01

    The marked endocrine changes that occur in anorexia nervosa have aroused a great deal of interest, and over the last decade much research has been conducted in this field. The endocrine disturbances are not specific to this disorder, as they also occur in starvation states secondary to other causes...... of the large body of literature concerning endocrine aspects of anorexia nervosa with the main focus on the latest results, which provide leads for potential etiological theories....

  15. Influence of geomagnetic disturbance on atmospheric circulation

    Science.gov (United States)

    Kodera, K.

    1985-01-01

    The influence of geomagnetic disturbance or passage of the solar sector boundary on the atmospheric circulation was reported. Unfortunately little is known about the general morphology of Sun weather relationships. In order to know the general characteristics, pressure height variations on an isobaric surface over the Northern Hemisphere were analyzed. Although it may be suitable to use some index, or some integrated value for statistical purposes, weather prediction data were used to verify whether the obtained tropospheric response is caused externally or not.

  16. Earthworms – good indicators for forest disturbance

    OpenAIRE

    YAHYA KOOCH; KATAYOUN HAGHVERDI

    2014-01-01

    In temperate forests, formation of canopy gaps by windthrow is a characteristic natural disturbance event. Little work has been done on the effects of canopy gaps on soil properties and fauna, especially earthworms as ecosystem engineers. We conducted a study to examine the reaction of earthworms (density/biomass) and different soil properties (i.e., soil moisture, pH, organic matter, total N, and available Ca) to different canopy gap areas in 25-ha areas of Liresar district beech forest loca...

  17. Sleep disturbance in older ICU patients.

    Science.gov (United States)

    Sterniczuk, Roxanne; Rusak, Benjamin; Rockwood, Kenneth

    2014-01-01

    Maintaining a stable and adequate sleeping pattern is associated with good health and disease prevention. As a restorative process, sleep is important for supporting immune function and aiding the body in healing and recovery. Aging is associated with characteristic changes to sleep quantity and quality, which make it more difficult to adjust sleep-wake rhythms to changing environmental conditions. Sleep disturbance and abnormal sleep-wake cycles are commonly reported in seriously ill older patients in the intensive care unit (ICU). A combination of intrinsic and extrinsic factors appears to contribute to these disruptions. Little is known regarding the effect that sleep disturbance has on health status in the oldest of old (80+), a group, who with diminishing physiological reserve and increasing prevalence of frailty, is at a greater risk of adverse health outcomes, such as cognitive decline and mortality. Here we review how sleep is altered in the ICU, with particular attention to older patients, especially those aged ≥80 years. Further work is required to understand what impact sleep disturbance has on frailty levels and poor outcomes in older critically ill patients.

  18. Preserving geomorphic data records of flood disturbances

    Science.gov (United States)

    Moody, John A.; Martin, Deborah; Meade, Robert H.

    2015-01-01

    No central database or repository is currently available in the USA to preserve long-term, spatially extensive records of fluvial geomorphic data or to provide future accessibility. Yet, because of their length and continuity these data are valuable for future research. Therefore, we built a public accessible website to preserve data records of two examples of long-term monitoring (40 and 18 years) of the fluvial geomorphic response to natural disturbances. One disturbance was ∼50-year flood on Powder River in Montana in 1978, and the second disturbance was a catastrophic flood on Spring Creek following a ∼100-year rainstorm after a wildfire in Colorado in 1996.Two critical issues arise relative to preserving fluvial geomorphic data. The first is preserving the data themselves, but the second, and just as important, is preserving information about the location of the field research sites where the data were collected so the sites can be re-located and re-surveyed in the future. The latter allows long-term datasets to be extended into the future and to provide critical background data for interpreting future landscape changes. Data were preserved on a website to allow world-wide accessibility and to upload new data to the website as they become available. We describe the architecture of the website, lessons learned in developing the website, future improvements, and recommendations on how also to preserve information about the location of field research sites.

  19. Sleep disturbance in older ICU patients

    Directory of Open Access Journals (Sweden)

    Sterniczuk R

    2014-06-01

    Full Text Available Roxanne Sterniczuk,1–3 Benjamin Rusak,1,2 Kenneth Rockwood31Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, 2Department of Psychiatry, Dalhousie University, Queen Elizabeth II Health Sciences Centre, Halifax, NS, 3Division of Geriatric Medicine, Department of Medicine, Queen Elizabeth II Health Sciences Centre, Halifax, NS, CanadaAbstract: Maintaining a stable and adequate sleeping pattern is associated with good health and disease prevention. As a restorative process, sleep is important for supporting immune function and aiding the body in healing and recovery. Aging is associated with characteristic changes to sleep quantity and quality, which make it more difficult to adjust sleep–wake rhythms to changing environmental conditions. Sleep disturbance and abnormal sleep–wake cycles are commonly reported in seriously ill older patients in the intensive care unit (ICU. A combination of intrinsic and extrinsic factors appears to contribute to these disruptions. Little is known regarding the effect that sleep disturbance has on health status in the oldest of old (80+, a group, who with diminishing physiological reserve and increasing prevalence of frailty, is at a greater risk of adverse health outcomes, such as cognitive decline and mortality. Here we review how sleep is altered in the ICU, with particular attention to older patients, especially those aged ≥80 years. Further work is required to understand what impact sleep disturbance has on frailty levels and poor outcomes in older critically ill patients.Keywords: intensive care unit, sleep–wake rhythm, aging, frailty

  20. Sleep disturbances in myotonic dystrophy type 2.

    Science.gov (United States)

    Shepard, Paul; Lam, Erek M; St Louis, Erik K; Dominik, Jacob

    2012-01-01

    Sleep disorders in myotonic dystrophy type 1 (DM1) are common and include sleep-disordered breathing, hypersomnia, and fatigue. Little is known regarding the occurrence of sleep disturbance in myotonic dystrophy type 2 (DM2). We hypothesized that DM2 patients may frequently harbor sleep disorders. We reviewed medical records of all genetically confirmed cases of DM2 seen at our sleep center between 1997 and 2010 for demographic, laboratory, overnight oximetry, and polysomnography (PSG) data. Eight patients (5 women, 3 men) with DM2 were identified. Excessive daytime sleepiness was seen in 6 patients (75%), insomnia in 5 (62.5%), and excessive fatigue in 4 (50%). Obstructive sleep apnea was diagnosed in 3 of 5 patients (60%) studied with PSG. Respiratory muscle weakness was present in all 6 patients (100%) who received pulmonary function testing. Four of 8 (50%) met criteria for diagnosis of restless legs syndrome. The clinical spectrum of DM2 may include a wide range of sleep disturbances. Although respiratory muscle weakness was frequent, sustained sleep-related hypoxia suggestive of hypoventilation was not seen in our patients. Further prospective studies are needed to examine the frequency and scope of sleep disturbances in DM2. Copyright © 2012 S. Karger AG, Basel.

  1. Earthworms – good indicators for forest disturbance

    Directory of Open Access Journals (Sweden)

    YAHYA KOOCH

    2014-08-01

    Full Text Available In temperate forests, formation of canopy gaps by windthrow is a characteristic natural disturbance event. Little work has been done on the effects of canopy gaps on soil properties and fauna, especially earthworms as ecosystem engineers. We conducted a study to examine the reaction of earthworms (density/biomass and different soil properties (i.e., soil moisture, pH, organic matter, total N, and available Ca to different canopy gap areas in 25-ha areas of Liresar district beech forest located in a temperate forest of Mazandaran province in the north of Iran. Soil samples were taken at 0-15, 15-30 and 30-45 cm depths from gap center, gap edge and closed canopy using core soil sampler with 81 cm2 cross section. The earthworms were collected simultaneously with the soil sampling by hand sorting method. Our study supports that the canopy gap will create a mosaic of environmental conditions. Earthworm's density and biomass tended to be higher in small canopy gaps compared with the other canopy gap areas. Earthworm's population showed decreasing trend from closed canopy to disturbed sites (gap edge and gap center. The top soil was more appropriate to presence of earthworms although ecological groups have occupied different soil layers. As a conclusion, earthworms can be introduced as good bio-indicator of environmental changes that occur by disturbance.

  2. Kristian Birkeland's pioneering investigations of geomagnetic disturbances

    Directory of Open Access Journals (Sweden)

    W. J. Burke

    2010-04-01

    Full Text Available More than 100 years ago Kristian Birkeland (1967–1917 addressed questions that had vexed scientists for centuries. Why do auroras appear overhead while the Earth's magnetic field is disturbed? Are magnetic storms on Earth related to disturbances on the Sun? To answer these questions Birkeland devised terrella simulations, led coordinated campaigns in the Arctic wilderness, and then interpreted his results in the light of Maxwell's synthesis of laws governing electricity and magnetism. After analyzing thousands of magnetograms, he divided disturbances into 3 categories:

    1. Polar elementary storms are auroral-latitude disturbances now called substorms.
    2. Equatorial perturbations correspond to initial and main phases of magnetic storms.
    3. Cyclo-median perturbations reflect enhanced solar-quiet currents on the dayside.

    He published the first two-cell pattern of electric currents in Earth's upper atmosphere, nearly 30 years before the ionosphere was identified as a separate entity. Birkeland's most enduring contribution toward understanding geomagnetic disturbances flowed from his recognition that field-aligned currents must connect the upper atmosphere with generators in distant space. The existence of field-aligned currents was vigorously debated among scientists for more than 50 years. Birkeland's conjecture profoundly affects present-day understanding of auroral phenomena and global electrodynamics. In 1896, four years after Lord Kelvin rejected suggestions that matter passes between the Sun and Earth, and two years before the electron was discovered, Birkeland proposed current carriers are "electric corpuscles from the Sun" and "the auroras are formed by corpuscular rays drawn in from space, and coming from the Sun". It can be reasonably argued that the year 1896 marks the founding of space plasma physics. Many of Birkeland's insights were rooted in observations made during his terrella

  3. Rapid disturbances in Arctic permafrost regions (Invited)

    Science.gov (United States)

    Grosse, G.; Romanovsky, V. E.; Arp, C. D.; Jones, B. M.

    2013-12-01

    Permafrost thaw is often perceived as a slow process dominated by press disturbances such as gradual active layer thickening. However, various pulse disturbances such as thermokarst formation can substantially increase the rate of permafrost thaw and result in rapid landscape change on sub-decadal to decadal time scales. Other disturbances associated with permafrost thaw are even more dynamic and unfold on sub-annual timescales, such as catastrophic thermokarst lake drainage. The diversity of processes results in complex feedbacks with soil carbon pools, biogeochemical cycles, hydrology, and flora and fauna, and requires a differentiated approach when quantifying how these ecosystem componentsare affected,how vulnerablethey are to rapid change, and what regional to global scale impacts result. Here we show quantitative measurements for three examples of rapid pulse disturbances in permafrost regions as observed with remote sensing data time series: The formation of a mega thaw slump (>50 ha) in syngenetic permafrost in Siberia, the formation of new thermokarst ponds in ice-rich permafrost regions in Alaska and Siberia, and the drainage of thermokarst lakes along a gradient of permafrost extent in Western Alaska. The surprising setting and unabated growth of the mega thaw slump during the last 40 years indicates that limited information on panarctic ground ice distribution, abundance, and vulnerability remains a key gap for reliable projections of thermokarst and thermo-erosion impacts, and that the natural limits on the growth and size of thaw slumps are still poorly understood. Observed thermokarst pond formation and expansion in our study regions was closely tied to ice-rich permafrost terrain, such as syngenetic Yedoma uplands, but was also found in old drained thermokarst lake basins with epigenetic permafrost and shallow drained thermokarst lake basins whose ground ice had not been depleted by the prior lake phase. The very different substrates in which new

  4. Disturbance and California riparian tree establishment

    Science.gov (United States)

    Bendix, J.; Cowell, C. M.

    2010-12-01

    As is the case in many ecosystems, tree establishment in riparian corridors is often episodic, following disturbance events that clear colonization sites. In many riparian settings, flooding is the most obvious, and relevant disturbance agent. However, in Mediterranean-climate regions, fire is an equally important disturbance agent. In California, the frequency and severity of both floods and fire are expected to change with projected climate change, making an understanding of their roles key to understanding future ecological processes in California riparian environments. In this paper, we use tree-ring data from the Transverse Ranges of Southern California to explore the relative importance of fire and flood in the establishment of riparian gallery forest. We examined 42 cores of Alnus rhombifolia, Populus fremontii and Quercus agrifolia from the riparian zone adjacent to Piedra Blanca and Potrero John Creeks in California’s Transverse Ranges, and compared their establishment dates with records of fire and floods, to see how establishment related to disturbance history. Our results show some evidence for major fire having an impact, as all of the largest stems dated to the few years following the 1932 Matilija fire, which had burned all of the sites in our sample. The remainder of the record is less straightforward, although there is an establishment peak in the 1970s, which may be related to a 1975 fire that burned part of the Potrero John watershed. Of note, the establishment chronology shows no relationship to the flood record, as years of major floods do not relate to either prolific or sparse years in the tree-ring record. This record suggests that large fires may serve as a trigger for tree establishment in California riparian settings, but that they are hardly a prerequisite, as many stems germinated between fires. Indeed, ongoing regeneration is apparently independent of disturbance, given the apparent irrelevance of flooding in this regard. The result

  5. Disturbance and the dynamics of fynbos biome communities

    CSIR Research Space (South Africa)

    Cowling, RM

    1987-01-01

    Full Text Available This volume comprises invited review and research papers dealing with the effects of disturbance on the dynamics of fynbos biome communities. Since fire is the most important disturbance factor in the biome, most contributions concentrate...

  6. Impulsive Flocking of Dynamical Multiagent Systems with External Disturbances

    Directory of Open Access Journals (Sweden)

    Fujun Han

    2017-01-01

    Full Text Available Flocking motion of multiagent systems is influenced by various external disturbances in complex environment. By applying disturbance observer, flocking of multiagent systems with exogenous disturbances is studied. Based on the robust features of impulsive control, a distributed impulsive control protocol is presented with disturbance observer, and flocking motion of multiagent systems is analyzed. Moreover, a sufficient condition is obtained to ensure the flocking motion of multiagent systems following a leader. Finally, simulation results show the validity of the theoretical conclusion.

  7. Changes in Soil Fungal Community Structure with Increasing Disturbance Frequency.

    Science.gov (United States)

    Cho, Hyunjun; Kim, Mincheol; Tripathi, Binu; Adams, Jonathan

    2017-07-01

    Although disturbance is thought to be important in many ecological processes, responses of fungal communities to soil disturbance have been little studied experimentally. We subjected a soil microcosm to physical disturbance, at a range of frequencies designed to simulate ecological disturbance events. We analyzed the fungal community structure using Illumina HiSeq sequencing of the ITS1 region. Fungal diversity was found to decline with the increasing disturbance frequencies, with no sign of the "humpback" pattern found in many studies of larger sedentary organisms. There is thus no evidence of an effect of release from competition resulting from moderate disturbance-which suggests that competition and niche overlap may not be important in limiting soil fungal diversity. Changing disturbance frequency also led to consistent differences in community composition. There were clear differences in OTU-level composition, with different disturbance treatments each having distinct fungal communities. The functional profile of fungal groups (guilds) was changed by the level of disturbance frequency. These predictable differences in community composition suggest that soil fungi can possess different niches in relation to disturbance frequency, or time since last disturbance. Fungi appear to be most abundant relative to bacteria at intermediate disturbance frequencies, on the time scale we studied here.

  8. Development of a Scale To Assess Emotional Disturbance.

    Science.gov (United States)

    Epstein, Michael H.; Cullinan, Douglas; Ryser, Gail; Pearson, Nils

    2002-01-01

    This study reports on the standardization of the Scale for Assessing Emotional Disturbance. Data collected on 2,266 typical students (ages 5- 18) and 1,371 students with emotional disturbances led to the identification of six behavioral problem factors that correspond to the federal definition of emotional disturbance and were highly internally…

  9. Mapping forest canopy disturbance in the Upper Great Lakes, USA

    Science.gov (United States)

    James D. Garner; Mark D. Nelson; Brian G. Tavernia; Charles H. (Hobie) Perry; Ian W. Housman

    2015-01-01

    A map of forest canopy disturbance was generated for Michigan, Wisconsin, and most of Minnesota using 42 Landsat time series stacks (LTSS) and a vegetation change tracker (VCTw) algorithm. Corresponding winter imagery was used to reduce commission errors of forest disturbance by identifying areas of persistent snow cover. The resulting disturbance age map was classed...

  10. Post-disturbance sediment recovery: Implications for watershed resilience

    Science.gov (United States)

    Sara L. Rathburn; Scott M. Shahverdian; Sandra E. Ryan

    2017-01-01

    Sediment recovery following disturbances is a measure of the time required to attain pre-disturbance sediment fluxes. Insight into the controls on recovery processes and pathways builds understanding of geomorphic resilience.We assess post-disturbance sediment recovery in three small (1.5-100 km2), largely unaltered watersheds within the northern Colorado...

  11. DisturbED: A Generalized Framework for Modeling Forest Insects and Pathogens in the Earth System

    Science.gov (United States)

    Matthes, J. H.

    2016-12-01

    Forest insects and pathogens (FIPs) are ubiquitous agents of disturbance that cause major alterations to ecosystem function and billions of dollars in damage annually. Future feedbacks between FIPs, forests, and climate change are not well understood at continental scales, due in part to the absence of the processes modulated by FIPs within Earth System Models (ESMs). To address this challenge, we developed a generalized, globally-scalable framework — DisturbED — in which mechanistic impacts of FIPs on plant physiology are scaled up to ecosystem-level processes so they can be integrated into ESMs. This framework can be used to test a suite of hypotheses concerning the effects of FIPs on forest biogeochemistry, demography, and structure in response to FIPs that vary in their host specificity, timescale and intensity of attack, and sensitivity to climatic change. Both native and invasive FIPs initiate a vast range of ecophysiological responses within individual trees, from slight stress and recovery to rapid mortality. Rather than modeling FIPs as direct agents of mortality, DisturbED couples FIP functional types with changes in individual host plant physiology to simulate resulting changes in ecosystem processes within the Ecosystem Demography (ED) model. This bottom-up modeling framework will allow for investigation of interactions among tree and FIPs physiology; demography and ecosystem dynamics; and their contingency on climatic change.

  12. Methodology to assess quality of estimated disturbances in active disturbance rejection control structure for mechanical system.

    Science.gov (United States)

    Rosas, A David; Velazquez, V Karla; Olivares, F Luz; Camacho, T Adrian; Williams, Ivan

    2017-09-01

    A methodology to assess the quality of estimation of disturbances in mechanical systems, by state observers, in the control structure with active compensation of disturbances (ADRC) is presented. Evaluation is carried out by four performance indices that depend on the steady-state error between reference signals and output of the plant. These indices are related with the accuracy and precision of the closed loop system in the sense of norms L 2 and L ∞ , for a set of reference signals representing the typical operating conditions of the mechanism. The effectiveness of the methodology is illustrated with the quality assessment of the estimated disturbance of five state observers to control of a simple pendulum and validated on a SCARA robot arm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Physiology of respiratory disturbances in muscular dystrophies.

    Science.gov (United States)

    Lo Mauro, Antonella; Aliverti, Andrea

    2016-12-01

    Muscular dystrophy is a group of inherited myopathies characterised by progressive skeletal muscle wasting, including of the respiratory muscles. Respiratory failure, i.e . when the respiratory system fails in its gas exchange functions, is a common feature in muscular dystrophy, being the main cause of death, and it is a consequence of lung failure, pump failure or a combination of the two. The former is due to recurrent aspiration, the latter to progressive weakness of respiratory muscles and an increase in the load against which they must contract. In fact, both the resistive and elastic components of the work of breathing increase due to airway obstruction and chest wall and lung stiffening, respectively. The respiratory disturbances in muscular dystrophy are restrictive pulmonary function, hypoventilation, altered thoracoabdominal pattern, hypercapnia, dyspnoea, impaired regulation of breathing, inefficient cough and sleep disordered breathing. They can be present at different rates according to the type of muscular dystrophy and its progression, leading to different onset of each symptom, prognosis and degree of respiratory involvement. A common feature of muscular dystrophy is respiratory failure, i.e. the inability of the respiratory system to provide proper oxygenation and carbon dioxide elimination.In the lung, respiratory failure is caused by recurrent aspiration, and leads to hypoxaemia and hypercarbia.Ventilatory failure in muscular dystrophy is caused by increased respiratory load and respiratory muscles weakness.Respiratory load increases in muscular dystrophy because scoliosis makes chest wall compliance decrease, atelectasis and fibrosis make lung compliance decrease, and airway obstruction makes airway resistance increase.The consequences of respiratory pump failure are restrictive pulmonary function, hypoventilation, altered thoracoabdominal pattern, hypercapnia, dyspnoea, impaired regulation of breathing, inefficient cough and sleep disordered

  14. Basic self-disturbance, neurocognition and metacognition

    DEFF Research Database (Denmark)

    Koren, Dan; Scheyer, Ravit; Reznik, Noa

    2017-01-01

    -seeking adolescents (age 13-18) were assessed with the examination of anomalous self-experience, the structured interview for prodromal syndromes and a new metacognitive approach to neurocognitive assessment applied to two non-social (executive functions and verbal memory) and two social (theory of mind and emotion......AIM: The goal of this pilot study was to assess the association between basic self-disturbance (SD) and deficits in neurocognitive and metacognitive functioning among help-seeking adolescents with and without attenuated psychosis syndrome (APS). METHODS: Sixty-one non-psychotic, help...

  15. [Primary antiphospholipid syndrome and cerebrovascular disturbances].

    Science.gov (United States)

    Kalashnikova, L A

    2005-01-01

    Neurological, including cecbrovascular, disorders frequently emerge in primary antiphospholipid syndrome (PAS). Clinical peculiarities of PAS were studied in 113 patients with cerebrovascular disturbances. Its had mainly ischemic patogenesis. Structure of cerebrovascular disorders was as follows: stroke (33% cases), transient ischemic lesions (10%), its combination (57%), thrombosis of brain venous sinuses (3%), vascular dementia (27%). Besides it were found epileptic seizures, peripheral neuropathy, headache, chorea and some symptoms of myasthenia, parkinsonism, multiple sclerosis and psychotic disorders. In all cases antibodies to phospholipids have been detected. Secondary prophylaxis includes regular use of anticoagulants and small doses of aspiriny.

  16. Neurological and Sleep Disturbances in Bronchiectasis

    Directory of Open Access Journals (Sweden)

    Chun Seng Phua

    2017-11-01

    Full Text Available Bronchiectasis unrelated to cystic fibrosis is a chronic lung disease that is increasingly recognised worldwide. While other common chronic lung conditions such as chronic obstructive lung disease have been associated with cardiovascular disease, there is a paucity of data on the relationship between bronchiectasis and cardiovascular risks such as stroke and sleep disturbance. Furthermore, it is unclear whether other neuropsychological aspects are affected, such as cognition, cerebral infection, anxiety and depression. In this review, we aim to highlight neurological and sleep issues in relation to bronchiectasis and their importance to patient care.

  17. Disturbance alters local-regional richness relationships in appalachian forests

    Science.gov (United States)

    Belote, R.T.; Sanders, N.J.; Jones, R.H.

    2009-01-01

    Whether biological diversity within communities is limited by local interactions or regional species pools remains an important question in ecology. In this paper, we investigate how an experimentally applied tree-harvesting disturbance gradient influenced local-regional richness relationships. Plant species richness was measured at three spatial scales (2 ha = regional; 576 m2 and 1 m2 = local) on three occasions (one year pre-disturbance, one year post-disturbance, and 10 years post-disturbance) across five disturbance treatments (uncut control through clearcut) replicated throughout the southern Appalachian Mountains, USA. We investigated whether species richness in 576-m2 plots and 1-m2 subplots depended on species richness in 2-ha experimental units and whether this relationship changed through time before and after canopy disturbance. We found that, before disturbance, the relationship between local and regional richness was weak or nonexistent. One year after disturbance local richness was a positive function of regional richness, because local sites were colonized from the regional species pool. Ten years after disturbance, the positive relationship persisted, but the slope had decreased by half. These results suggest that disturbance can set the stage for strong influences of regional species pools on local community assembly in temperate forests. However, as time since disturbance increases, local controls on community assembly decouple the relationships between regional and local diversity. ?? 2009 by the Ecological Society of America.

  18. Changing disturbance regimes, ecological memory, and forest resilience

    Science.gov (United States)

    Johnstone, Jill F.; Allen, Craig D.; Franklin, Jerry F.; Frelich, Lee E.; Harvey, Brian J.; Higuera, Philip E.; Mack, Michelle C.; Meentemeyer, Ross K.; Metz, Margaret R.; Perry, George LW; Schoennagel, Tania; Turner, Monica G.

    2016-01-01

    Ecological memory is central to how ecosystems respond to disturbance and is maintained by two types of legacies – information and material. Species life-history traits represent an adaptive response to disturbance and are an information legacy; in contrast, the abiotic and biotic structures (such as seeds or nutrients) produced by single disturbance events are material legacies. Disturbance characteristics that support or maintain these legacies enhance ecological resilience and maintain a “safe operating space” for ecosystem recovery. However, legacies can be lost or diminished as disturbance regimes and environmental conditions change, generating a “resilience debt” that manifests only after the system is disturbed. Strong effects of ecological memory on post-disturbance dynamics imply that contingencies (effects that cannot be predicted with certainty) of individual disturbances, interactions among disturbances, and climate variability combine to affect ecosystem resilience. We illustrate these concepts and introduce a novel ecosystem resilience framework with examples of forest disturbances, primarily from North America. Identifying legacies that support resilience in a particular ecosystem can help scientists and resource managers anticipate when disturbances may trigger abrupt shifts in forest ecosystems, and when forests are likely to be resilient.

  19. Disturbance History,Spatial Variability, and Patterns of Biodiversity

    Science.gov (United States)

    Bendix, J.; Wiley, J. J.; Commons, M.

    2012-12-01

    The intermediate disturbance hypothesis predicts that species diversity will be maximized in environments experiencing intermediate intensity disturbance, after an intermediate timespan. Because many landscapes comprise mosaics with complex disturbance histories, the theory implies that each patch in those mosaics should have a distinct level of diversity reflecting combined impact of the magnitude of disturbance and the time since it occurred. We modeled the changing patterns of species richness across a landscape experiencing varied scenarios of simulated disturbance. Model outputs show that individual landscape patches have highly variable species richness through time, with the details reflecting the timing, intensity and sequence of their disturbance history. When the results are mapped across the landscape, the resulting temporal and spatial complexity illustrates both the contingent nature of diversity and the danger of generalizing about the impacts of disturbance.

  20. Turned trochoidal disturbance on a liquid jet surface

    Science.gov (United States)

    Sadik, Shalom; Kirzhner, Felix; Kramarenko, Denis

    2014-07-01

    This paper shows that a turned trochoidal function disturbance may lead to peripheral drops production. The resulting model is used to describe that a turned trochoidal disturbance leads to peripheral drops production on the liquid jet surface without the necessity for superimposed disturbances. The trochoid is a non-unique parametric function. Only non-unique parametric functions disturbances may lead to peripheral drops production. The trochoidal function disturbance is decomposed to Fourier series. Every Fourier element receives an amplification factor in accordance to the Rayleigh inviscid jet model. Peripheral drops are received on the jet surface. The paper shows that all trochoidal disturbance functions, prolate cycloid, cycloid and curtate cycloid have a capability of peripheral drops producing. A limited capability of peripheral drops production is introduced for the trochoidal curtate cycloid. Produced drops size are reduced for increasing the jet velocity and wave number. Smaller drops are also received by transition from the prolate cycloid to curtate cycloid disturbance.

  1. Early Menarche and Menstrual Problems Are Associated with Sleep Disturbance in a Large Sample of Chinese Adolescent Girls.

    Science.gov (United States)

    Liu, Xianchen; Chen, Hua; Liu, Zhen-Zhen; Fan, Fang; Jia, Cun-Xian

    2017-09-01

    Little is known about the association between menstruation and sleep disturbance in adolescent girls. This study examined sleep duration, insomnia symptoms, and sleep quality in relation to age at menarche and menstrual problems in a large sample of Chinese adolescent girls. This report represents the baseline data of an ongoing longitudinal study of the Shandong Adolescent Behavior & Health Cohort in Shandong, China. A total of 5800 girls aged 12-18 years (mean age = 15.0, standard deviation = 1.4) participated in the baseline survey. A structured questionnaire was used to assess participants' age at menarche, menstrual cycle interval, menstrual flow length, period irregularity, period pain, body weight and height, and demographics. Internalizing and externalizing problems were measured by the Youth-Self Report of Child Behavioral Checklist. Sleep duration, insomnia symptoms, and sleep quality were assessed by the items adapted from the Pittsburgh Sleep Quality Index. After adjusting for age, school, body mass index, internalizing and externalizing problems, and family covariates, irregular periods (odds ratio [OR] = 1.46, 95% confidence interval [CI] = 1.06-2.02), period pain (OR = 1.99, 95% CI = 1.44-2.76), and menstrual flow length ≥7 days (OR = 1.21, 95% CI = 1.00-1.48) were significantly associated with insomnia symptoms. Irregular periods (OR = 1.72, 95% CI = 1.30-2.27) and period pain (OR = 1.78, 95% CI = 1.34-2.37) were significantly associated with poor sleep quality. Age at menarche ≤11 years (OR = 1.62, 95% CI = 1.05-2.50) was significantly associated with insomnia symptoms in 12- to 14-year-old girls. Our results suggest that irregular periods and period pain appear to be associated with sleep disturbance and that early menarche may have short-term impact on sleep in adolescent girls. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e

  2. Ionospheric climatology and weather disturbances: A tutorial

    Science.gov (United States)

    Schunk, R. W.

    The ionosphere can have a detrimental effect on both civilian and military systems, including OTH radars, HF communications, surveillance, and navigation systems that use GPS satellites. In an attempt to mitigate the adverse effects, specification and forecast models are being developed that are based on sophisticated data assimilation techniques. However, the model development represents a significant challenge because the ionosphere is known to display a marked variation with altitude, latitude, longitude, universal time, season, solar cycle, and geomagnetic activity. This variation results from the couplings, time delays, and feedback mechanisms that are inherent in the system as well as from the effects of solar, interplanetary, magnetospheric, and mesospheric processes. The various processes act in concert to define both a background state (climatology) and a disturbed state (weather), which are described in this tutorial. First, a brief description of the background ionospheric state and the physical processes that are responsible for establishing this state is given. The tutorial then focuses on a discussion of weather disturbances and features, the causes of weather, and the status of weather modeling.

  3. Global Telecommunications Security: Effects of Geomagnetic Disturbances

    Directory of Open Access Journals (Sweden)

    D.J. McManus

    2011-07-01

    Full Text Available Global information and communication technologies permeate organizational structures, while questions of security pervade strategic plans of corporations worldwide. From the spectacular to the sublime, the effects of geomagnetic disturbances (i.e., electrical current produced by solar storms can be as devastating to an organization’s telecommunications systems as a hacker breaching a firewall. Using a dataset spanning 31 years (1978-2009 with 580,000 solar activity records, we investigate the effects and relationships of natural anomalies, specifically solar storms, on the security of corporate telecommunications. The ionosphere is a natural barrier around the earth to protect it from the sun and serve as a shield, but some electrical currents break this barrier causing significant telecommunications outages and security breaches within corporations. In this exploratory empirical study, we present the initial evidence that tracking geomagnetic disturbances can provide vital cautions for business continuity planning. The results of the study should help organizations with strategic planning efforts with respect to their overall security, especially as it relates to telecommunications.

  4. Cortical activation following a balance disturbance.

    Science.gov (United States)

    Quant, S; Adkin, A L; Staines, W R; McIlroy, W E

    2004-04-01

    Although recent work suggests that cortical processing can be involved in the control of balance responses, the central mechanisms involved in these reactions remain unclear. We presently investigated the characteristics of scalp-recorded perturbation-evoked responses (PERs) following a balance disturbance. Eight young adults stabilized an inverted pendulum using their ankle musculature while seated. When perturbations were applied to the pendulum, subjects were instructed to return (active condition) or not return (passive condition) the pendulum to its original stable position. Primary measures included peak latency and amplitude of early PERs (the first negative peak between 100 and 150 ms, N1), amplitude of late PERs (between 200 and 400 ms) and onset and initial amplitude of ankle muscle responses. Based on the timing of PERs, we hypothesized that N1 would represent sensory processing of the balance disturbance and that late PERs would be linked to the sensorimotor processing of balance corrections. Our results revealed that N1 was maximal over frontal-central electrode sites (FCz and Cz). Average N1 measures at FCz, Cz, and CPz were comparable between active and passive tasks ( p>0.05). In contrast, the amplitude of late PERs at Cz was less positive for the active condition than for the passive ( psensory representation of early PERs. Differences in late PERs may represent sensorimotor processing related to the execution of balance responses.

  5. Orographic Disturbances of Upper Atmosphere Emissions

    Science.gov (United States)

    Shefov, N. N.; Pertsev, N. N.

    1984-01-01

    There are some increases of the temperature of the hydroxyl emission (delta T approximately 20 K, z approximately 90 km) and of the intensity of the 63000 oxygen emission (delta I/I approximately 20 per cent, z approximately 250 km) for the lee of the mountains at distances about 150 km in the case of the latitudinal direction of the wind (U approximately 10 m/s) at the 3000 m level. Airflow motions over mountains may be one of the possible processes of generation of wave disturbances penetrating into the upper atmospheres (HINES, 1974; LINDZEN, 1971). The purpose here is to study the penetration of orographic disturbances into upper atmosphere. Airplane measurements of emission variations of hydroxyl and atomic oxygen 6300 A near the Northern Ural mountains were made. Several nocturnal flights were carried out in March, 1980 and January to February, 1981 at heights about 3000 m along 64 deg northern latitude in the Ural region. Spectrographs SP-48 with electronic image converters registration for OH ((9,4) and (5,1) bands - 7700 to 8100 A) and OI (6300 A) emissions were used. The zenith region was observed, and exposure time was 2 minutes. This corresponds to averaging of the emission intensities along the airplane trace over a distance of 10 km. Simultaneous measurements of atmospheric temperature variations at the flight altitude were made.

  6. Wavelet Transform for Processing Power Quality Disturbances

    Directory of Open Access Journals (Sweden)

    H. Y. Zhu

    2007-01-01

    Full Text Available The emergence of power quality as a topical issue in power systems in the 1990s largely coincides with the huge advancements achieved in the computing technology and information theory. This unsurprisingly has spurred the development of more sophisticated instruments for measuring power quality disturbances and the use of new methods in processing and analyzing the measurements. Fourier theory was the core of many traditional techniques and it is still widely used today. However, it is increasingly being replaced by newer approaches notably wavelet transform and especially in the post-event processing of the time-varying phenomena. This paper reviews the use of wavelet transform approach in processing power quality data. The strengths, limitations, and challenges in employing the methods are discussed with consideration of the needs and expectations when analyzing power quality disturbances. Several examples are given and discussions are made on the various design issues and considerations, which would be useful to those contemplating adopting wavelet transform in power quality applications. A new approach of combining wavelet transform and rank correlation is introduced as an alternative method for identifying capacitor-switching transients.

  7. Disturbance observer-based L1 robust tracking control for hypersonic vehicles with T-S disturbance modeling

    Directory of Open Access Journals (Sweden)

    Yang Yi

    2016-11-01

    Full Text Available This article concerns a disturbance observer-based L1 robust anti-disturbance tracking algorithm for the longitudinal models of hypersonic flight vehicles with different kinds of unknown disturbances. On one hand, by applying T-S fuzzy models to represent those modeled disturbances, a disturbance observer relying on T-S disturbance models can be constructed to track the dynamics of exogenous disturbances. On the other hand, L1 index is introduced to analyze the attenuation performance of disturbance for those unmodeled disturbances. By utilizing the existing convex optimization algorithm, a disturbance observer-based proportional-integral-controlled input is proposed such that the stability of hypersonic flight vehicles can be ensured and the tracking error for velocity and altitude in hypersonic flight vehicle models can converge to equilibrium point. Furthermore, the satisfactory disturbance rejection and attenuation with L1 index can be obtained simultaneously. Simulation results on hypersonic flight vehicle models can reflect the feasibility and effectiveness of the proposed control algorithm.

  8. Disturbing pasts: Memories, controversies and creativity

    Directory of Open Access Journals (Sweden)

    Leon Wainwright

    2014-10-01

    Full Text Available This themed issue of the Open Arts Journal, ‘Disturbing pasts: Memories, controversies and creativity’, brings together a range of artists, curators, policy-makers and academics from around the world, who explore creative engagements with controversial and traumatic pasts in art practice, curating and museums. The material is presented in three parts: ‘Difficult Pasts and Public Space’ (writings on historical issues and museums, ‘Visual Investigations’ (artists’ statements and criticism, and ‘Collaborations’ (visual analysis and artist-scholar pairings of writings and original artworks. This collection was developed through a two-year international research project led by Leon Wainwright, which involved three consortia of researchers from universities throughout Europe, and focused on a major public event at the Museum of Ethnology Vienna/ Weltmuseum, Wien (November 2011. The project is funded by HERA (Humanities in the European Research Area, the European Science Foundation.

  9. SOME NEUROCHEMICAL DISTURBANCES IN MULTIPLE SCLEROSIS

    Directory of Open Access Journals (Sweden)

    Vladimir V. Markelov

    2006-04-01

    Full Text Available ABSTRACTThe data presented in this manuscript suggest a pivotal role of the central nervous system (CNS in the regulation of immune status. We describe here that some neurochemical disturbances may provoke development of various diseases including multiple sclerosis. Some theoretic and practical backgrounds, how to improve the multiple sclerosis sufferers and patients with other autoimmune disorders, are also given.RESUMENLos datos que presentamos en este manuscrito, sugieren un papel guia del sistema nervioso central (SNC en la regulación del estado inmune. Describimos aquí que varias alteraciones neuroquímicas pueden provocar el desarrollo de varias enfermedades, incluyendo esclerosis múltiple. También se comenta acerca del trasfondo teórico y práctico, y cómo mejorar a víctimas y pacientes con esclerosis múltiple y otras alteraciones autoinmunes.

  10. Estimation of Wave Disturbance in Harbours

    DEFF Research Database (Denmark)

    Helm-Petersen, Jacob

    seen for small changes in reflection coefficients. This points in the direction of a need for improvements of wave reflection prediction formulae. Finally comparisons between results from the numerical model and physical scale measurements from earlier experiments with the same harbour show......The motivation for the present study has been to improve the reliability in using numerical wave propagation models as a tool for estimating wave disturbance in harbours. Attention has been directed towards the importance of the modelling of reflection in the applied mild-slope model. Methods have...... been presented for the analysis of reflected wave fields in 2D and 3D. The Bayesian Directional Wave Spectrum Estimation Method has been applied throughout the study. Reflection characteristics have been investigated by use of physical models for three types of coastal structures with vertical fronts...

  11. Geophysical field disturbances and quantum mechanics

    Science.gov (United States)

    Kuznetsov, Vladimir

    2017-10-01

    Quantum processes impact into physics of geophysical field disturbances is discussed here in examples of phenomena such as an earthquake with processes preceding and accompanying it, volcanoes eruptions and diamond exploding pipes. Physics of shock waves generation in ionosphere and atmosphere, mechanism of atmosphere phenomena in supercooled clouds recorded by a stormglass is considered. The report treats of physics of ball and dark lightning, of generating in atmosphere the high-energy particles involved in sprites occurrence, and so on. Geophysical phenomena considered here have no clear and consistent interpretation in the context of classical physics. We attempt to involve the recent achievements of quantum physics namely the quantum entanglement between elementary particles implicated in considered phenomena.

  12. Associations of sleep disturbance with ADHD

    DEFF Research Database (Denmark)

    Hvolby, A.

    2015-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is commonly associated with disordered or disturbed sleep. The relationships of ADHD with sleep problems, psychiatric comorbidities and medications are complex and multidirectional. Evidence from published studies comparing sleep in individuals...... with ADHD with typically developing controls is most concordant for associations of ADHD with: hypopnea/apnea and peripheral limb movements in sleep or nocturnal motricity in polysomnographic studies; increased sleep onset latency and shorter sleep time in actigraphic studies; and bedtime resistance......, difficulty with morning awakenings, sleep onset difficulties, sleep-disordered breathing, night awakenings and daytime sleepiness in subjective studies. ADHD is also frequently coincident with sleep disorders (obstructive sleep apnea, peripheral limb movement disorder, restless legs syndrome and circadian...

  13. Monogamy Relations of Measurement-Induced Disturbance

    Science.gov (United States)

    Liu, Feng; Li, Fei; Wei, Yun-Xia; Ma, Hong-Yang

    2017-06-01

    The standard monogamy imposes severe limitations to sharing quantum correlations in multipartite quantum systems, which is a star topology and is established by Coffman, Kundu and Wootters. In this work, we discuss some monogamy relations beyond it, and focus on the measurement-induced disturbance (MID) which quantifies the multipartite quantum correlation. We prove exactly that MID obeys the property of discarding quantum systems never increases in an arbitrary quantum state. Moreover, we define a new kind of sharper monogamy relation which shows that the sum of all bipartite MID can not exceed the amount of total MID. This restriction is similarly called a mesh monogamy. We numerically study how MID is distributed in a 4-qubit mixed state, and which relation exists between the mesh monogamy of MID and the level of obeying the standard monogamy.

  14. Piston core properties and disturbance effects.

    Science.gov (United States)

    Olsen, H.W.; Rice, T.L.; Mayne, P.W.; Singh, R.D.

    1986-01-01

    Laboratory geotechnical data on piston cores for 31 sites on the mid-Atlantic Upper Continental Slope show the near-surface sediments vary from normally consolidated to somewhat overconsolidated clayey silts and silty clays of low to high plasticity. They also exhibit normalized behavior and their index property correlations with the effective-stress friction angle, the undrained strength ratio, and the compression index are reasonably consistent with existing knowledge. Because existing knowledge concerning disturbance effect suggests that in-situ preconsolidation stress values should lie between those derived from the triaxial and laboratory vane data, the preconsolidation stress values obtained from the consolidation data appear to be appreciably smaller than in-situ values. -from ASCE Publications Information

  15. [Ecotourism disturbances to non-human primates].

    Science.gov (United States)

    Fan, Peng-Lai; Xiang, Zuo-Fu

    2013-02-01

    In tandem with economic growth and rising living conditions, ecotourism has increasingly gained popularity among the Chinese public. Non-human primates, as charismatic animals and the closest relatives of human beings, have shown a strong affinity in attracting the general public and raising money, and for that reason a variety of monkey parks, valleys, and islands are becoming increasingly popular in China. Though successful in raising a substantial sum of money for the managing agency of a nature reserve, there may be negative impacts on monkey groups used in ecotourism. Here, to establish effective guards for non-human primates involved in ecotourism, we present a review on tourism disturbance and summarize the negative impacts on behavioral patterns, reproduction, and health condition of animals.

  16. Metabolic disturbances connecting obesity and depression

    Directory of Open Access Journals (Sweden)

    Cecile eHryhorczuk

    2013-10-01

    Full Text Available Obesity markedly increases the odds of developing depression. Depressed mood not only impairs motivation, quality of life and overall functioning but also increases the risks of obesity complications. Abdominal obesity is a better predictor of depression and anxiety risk than overall adipose mass. A growing amount of research suggests that metabolic abnormalities stemming from central obesity that lead to metabolic disease may also responsible for the increased incidence of depression in obesity. As reviewed here, a higher mass of dysfunctional adipose tissue is associated with several metabolic disturbances that are either directly or indirectly implicated in the control of emotions and mood. To better comprehend the development of depression in obesity, this review pulls together select findings addressing the link between adiposity, diet and negative emotional states and discusses the evidence that alterations in glucocorticoids, adipose-derived hormones and inflammatory signalling that are characteristic of central obesity may be involved.

  17. Disturbances of bone growth and development

    International Nuclear Information System (INIS)

    Ledesma-Medina, J.; Newman, B.; Oh, K.S.

    1988-01-01

    ''What is growth anyway? Can one talk about positive growth in childhood, neutral growth in maturity, and negative growth in old age? Our goal is to help promote normal positive growth in infants and children. To achieve this, we must be cognizant of the morphologic changes of both normal and abnormal bone formation as they are reflected in the radiographic image of the skeleton. The knowledge of the various causes and the pathophysiologic mechanisms of the disturbances of bone growth and development allows us to recognize the early radiographic manifestations. Endocrine and metabolic disorders affect the whole skeleton, but the early changes are best seen in the distal ends of the femurs, where growth rate is most rapid. In skeletal infections and in some vascular injuries two-or three-phase bone scintigraphy supercedes radiography early in the course of the disease. MRI has proved to be very helpful in the early detection of avascular bone necrosis, osteomyelitis, and tumor. Some benign bone tumors and many bone dysplasias have distinct and diagnostic radiographic findings that may preclude further studies. In constitutional diseases of bone, including chromosomal aberrations, skeletal surveys of the patient and all family members together with biochemical and cytogenetic studies are essential for both diagnosis and genetic counseling. Our role is to perform the least invasive and most informative diagnostic imaging modalities that corroborate the biochemical and histologic findings to establish the definitive diagnosis. Unrecognized, misdiagnosed, or improperly treated disturbance of bone growth can result in permanent deformity usually associated with disability. 116 references

  18. Probabilistic Assessment of Grid Disturbance Initiating Events

    International Nuclear Information System (INIS)

    Guptan, R.; Bajaj, S. S.

    2000-01-01

    Level-1 PSA of Kakrapar Atomic Power Station, an Indian PHWR, covering the internal initiating events is in progress. As part of this study, event tree analysis is taken up for the initiating event involving offsite power supply failure resulting due to grid disturbance, to analyze the various event sequences. Station Blackout is one of the scenarios analysed in this event tree. A recovery possibility of Class-III Power Supply is also postulated, failure of which is assumed to lead to an extended Station Blackout situation. The performance required of each function event/frontline system depends on both the initiators and the additional system failures or successes in a particular accident sequence. Hence, different definitions of success criteria and boundary conditions are identified accordingly for the various frontline system fault tree modelling. The concept of small evet tree and large fault tree is adopted. To identify the dominant Common Cause Failure (CCF) vulnerabilities, a detailed CCF analysis is carried out. Appropriate human error probabilities are used after giving due credit to performance shaping factors, emergency operating procedures and O and M checklists. Plant specific failure parameters are computed and Bayesian technique is used to calculate the posterior values. Subsequent to accident sequence quantification, importance analysis is carried out to determine the important accident sequences, system failures, component failures and human errors. It was observed that in spite of high frequency of grid disturbances, the onsite power supply (we have three Diesel Generators and one Diesel Generator is sufficient to cater to safety loads) is highly reliable and the frequency of core damage / Station Blackout is very low. (author)

  19. Trade-off between information and disturbance in qubit thermometry

    Science.gov (United States)

    Seveso, Luigi; Paris, Matteo G. A.

    2018-03-01

    We address the trade-off between information and disturbance in qubit thermometry from the perspective of quantum estimation theory. Given a quantum measurement, we quantify information via the Fisher information of the measurement and disturbance via four different figures of merit, which capture different aspects (statistical, thermodynamical, geometrical) of the trade-off. For each disturbance measure, the efficient measurements, i.e., the measurements that introduce a disturbance not greater than any other measurement extracting the same amount of information, are determined explicitly. The family of efficient measurements varies with the choice of the disturbance measure. On the other hand, commutativity between the elements of the probability operator-valued measure (POVM) and the equilibrium state of the thermometer is a necessary condition for efficiency with respect to any figure of disturbance.

  20. Reconstructing disturbances and their biogeochemical consequences over multiple timescales

    Science.gov (United States)

    McLauchlan, Kendra K.; Higuera, Philip E.; Gavin, Daniel G.; Perakis, Steven S.; Mack, Michelle C.; Alexander, Heather; Battles, John; Biondi, Franco; Buma, Brian; Colombaroli, Daniele; Enders, Sara K.; Engstrom, Daniel R.; Hu, Feng Sheng; Marlon, Jennifer R.; Marshall, John; McGlone, Matt; Morris, Jesse L.; Nave, Lucas E.; Shuman, Bryan; Smithwick, Erica A.H.; Urrego, Dunia H.; Wardle, David A.; Williams, Christopher J.; Williams, Joseph J.

    2014-01-01

    Ongoing changes in disturbance regimes are predicted to cause acute changes in ecosystem structure and function in the coming decades, but many aspects of these predictions are uncertain. A key challenge is to improve the predictability of postdisturbance biogeochemical trajectories at the ecosystem level. Ecosystem ecologists and paleoecologists have generated complementary data sets about disturbance (type, severity, frequency) and ecosystem response (net primary productivity, nutrient cycling) spanning decadal to millennial timescales. Here, we take the first steps toward a full integration of these data sets by reviewing how disturbances are reconstructed using dendrochronological and sedimentary archives and by summarizing the conceptual frameworks for carbon, nitrogen, and hydrologic responses to disturbances. Key research priorities include further development of paleoecological techniques that reconstruct both disturbances and terrestrial ecosystem dynamics. In addition, mechanistic detail from disturbance experiments, long-term observations, and chronosequences can help increase the understanding of ecosystem resilience.

  1. A theory of the Krakatoa tide gauge disturbances

    OpenAIRE

    Garrett, J. R.

    2011-01-01

    Tide gauge disturbances detected at many places around the world after the explosive eruption of Krakatoa in 1883 cannot be explained as free ocean waves travelling by the shortest sea route from Krakatoa, but were clearly correlated with the air wave. Previous explanations of the way in which the air wave caused the tide gauge disturbances are shown to be unsatisfactory from the point of view of both theory and observation. It is suggested that these disturbances were in fact free waves gene...

  2. Quantum Kolmogorov Complexity and Information-Disturbance Theorem

    Science.gov (United States)

    Miyadera, Takayuki

    2011-03-01

    In this paper, a representation of the information-disturbance theorem based on the quantum Kolmogorov complexity that was defined by P. Vitanyi has been examined. In the quantum information theory, the information-disturbance relationship, which treats the trade-off relationship between information gain and its caused disturbance, is a fundamental result that is related to Heisenberg's uncertainty principle. The problem was formulated in a cryptographic setting and quantitative relationships between complexities have been derived.

  3. Secondary plant succession on disturbed sites at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Angerer, J.P.; Ostler, W.K.; Gabbert, W.D.; Schultz, B.W.

    1994-12-01

    This report presents the results of a study of secondary plant succession on disturbed sites created during initial site investigations in the late 1970s and early 1980s at Yucca Mountain, NV. Specific study objectives were to determine the rate and success of secondary plant succession, identify plant species found in disturbances that may be suitable for site-specific reclamation, and to identify environmental variables that influence succession on disturbed sites. During 1991 and 1992, fifty seven disturbed sites were located. Vegetation parameters, disturbance characteristics and environmental variables were measured at each site. Disturbed site vegetation parameters were compared to that of undisturbed sites to determine the status of disturbed site plant succession. Vegetation on disturbed sites, after an average of ten years, was different from undisturbed areas. Ambrosia dumosa, Chrysothamnus teretifolius, Hymenoclea salsola, Gutierrezia sarothrae, Atriplex confertifolia, Atriplex canescens, and Stephanomeria pauciflora were the most dominant species across all disturbed sites. With the exception of A. dumosa, these species were generally minor components of the undisturbed vegetation. Elevation, soil compaction, soil potassium, and amounts of sand and gravel in the soil were found to be significant environmental variables influencing the species composition and abundance of perennial plants on disturbed sites. The recovery rate for disturbed site secondary succession was estimated. Using a linear function (which would represent optimal conditions), the recovery rate for perennial plant cover, regardless of which species comprised the cover, was estimated to be 20 years. However, when a logarithmic function (which would represent probable conditions) was used, the recovery rate was estimated to be 845 years. Recommendations for future studies and site-specific reclamation of disturbances are presented

  4. United States Forest Disturbance Trends Observed Using Landsat Time Series

    Science.gov (United States)

    Masek, Jeffrey G.; Goward, Samuel N.; Kennedy, Robert E.; Cohen, Warren B.; Moisen, Gretchen G.; Schleeweis, Karen; Huang, Chengquan

    2013-01-01

    Disturbance events strongly affect the composition, structure, and function of forest ecosystems; however, existing U.S. land management inventories were not designed to monitor disturbance. To begin addressing this gap, the North American Forest Dynamics (NAFD) project has examined a geographic sample of 50 Landsat satellite image time series to assess trends in forest disturbance across the conterminous United States for 1985-2005. The geographic sample design used a probability-based scheme to encompass major forest types and maximize geographic dispersion. For each sample location disturbance was identified in the Landsat series using the Vegetation Change Tracker (VCT) algorithm. The NAFD analysis indicates that, on average, 2.77 Mha/yr of forests were disturbed annually, representing 1.09%/yr of US forestland. These satellite-based national disturbance rates estimates tend to be lower than those derived from land management inventories, reflecting both methodological and definitional differences. In particular the VCT approach used with a biennial time step has limited sensitivity to low-intensity disturbances. Unlike prior satellite studies, our biennial forest disturbance rates vary by nearly a factor of two between high and low years. High western US disturbance rates were associated with active fire years and insect activity, while variability in the east is more strongly related to harvest rates in managed forests. We note that generating a geographic sample based on representing forest type and variability may be problematic since the spatial pattern of disturbance does not necessarily correlate with forest type. We also find that the prevalence of diffuse, non-stand clearing disturbance in US forests makes the application of a biennial geographic sample problematic. Future satellite-based studies of disturbance at regional and national scales should focus on wall-to-wall analyses with annual time step for improved accuracy.

  5. Secondary plant succession on disturbed sites at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Angerer, J.P.; Ostler, W.K.; Gabbert, W.D.; Schultz, B.W.

    1994-12-01

    This report presents the results of a study of secondary plant succession on disturbed sites created during initial site investigations in the late 1970s and early 1980s at Yucca Mountain, NV. Specific study objectives were to determine the rate and success of secondary plant succession, identify plant species found in disturbances that may be suitable for site-specific reclamation, and to identify environmental variables that influence succession on disturbed sites. During 1991 and 1992, fifty seven disturbed sites were located. Vegetation parameters, disturbance characteristics and environmental variables were measured at each site. Disturbed site vegetation parameters were compared to that of undisturbed sites to determine the status of disturbed site plant succession. Vegetation on disturbed sites, after an average of ten years, was different from undisturbed areas. Ambrosia dumosa, Chrysothamnus teretifolius, Hymenoclea salsola, Gutierrezia sarothrae, Atriplex confertifolia, Atriplex canescens, and Stephanomeria pauciflora were the most dominant species across all disturbed sites. With the exception of A. dumosa, these species were generally minor components of the undisturbed vegetation. Elevation, soil compaction, soil potassium, and amounts of sand and gravel in the soil were found to be significant environmental variables influencing the species composition and abundance of perennial plants on disturbed sites. The recovery rate for disturbed site secondary succession was estimated. Using a linear function (which would represent optimal conditions), the recovery rate for perennial plant cover, regardless of which species comprised the cover, was estimated to be 20 years. However, when a logarithmic function (which would represent probable conditions) was used, the recovery rate was estimated to be 845 years. Recommendations for future studies and site-specific reclamation of disturbances are presented.

  6. Distributed Coordination of Fractional Dynamical Systems with Exogenous Disturbances

    Directory of Open Access Journals (Sweden)

    Hongyong Yang

    2014-01-01

    Full Text Available Distributed coordination of fractional multiagent systems with external disturbances is studied. The state observer of fractional dynamical system is presented, and an adaptive pinning controller is designed for a little part of agents in multiagent systems without disturbances. This adaptive pinning controller with the state observer can ensure multiple agents' states reaching an expected reference tracking. Based on disturbance observers, the controllers are composited with the pinning controller and the state observer. By applying the stability theory of fractional order dynamical systems, the distributed coordination of fractional multiagent systems with external disturbances can be reached asymptotically.

  7. An Industrial Model Based Disturbance Feedback Control Scheme

    DEFF Research Database (Denmark)

    Kawai, Fukiko; Nakazawa, Chikashi; Vinther, Kasper

    2014-01-01

    This paper presents a model based disturbance feedback control scheme. Industrial process systems have been traditionally controlled by using relay and PID controller. However these controllers are affected by disturbances and model errors and these effects degrade control performance. The authors...... propose a new control method that can decrease the negative impact of disturbance and model errors. The control method is motivated by industrial practice by Fuji Electric. Simulation tests are examined with a conventional PID controller and the disturbance feedback control. The simulation results...... demonstrate the effectiveness of the proposed method comparing with the conventional PID controller...

  8. Homicides of law enforcement officers responding to domestic disturbance calls.

    Science.gov (United States)

    Kercher, Cassandra; Swedler, David I; Pollack, Keshia M; Webster, Daniel W

    2013-10-01

    To describe the law enforcement officer (LEO), encounter, perpetrator and victim characteristics of domestic disturbance-related LEO homicides in the USA from 1996 to 2010. Narrative text analysis was conducted on the Federal Bureau of Investigation's annual report 'Law Enforcement Officers Killed and Assaulted'. Potential cases were confirmed if the narrative included the term 'domestic disturbance' or a domestic disturbance situation was described. 116 LEOs were killed while responding to domestic disturbance calls. Ninety-five per cent of these homicides were committed with a firearm. Sixty-seven per cent of LEOs were wearing body armour when killed; however, 52% received the fatal wound to the head/neck. Sixty-one per cent of suspects had a criminal history mentioned within the narratives and perpetrators of intimate partner violence (IPV) were more likely to be killed by LEOs than suspects involved in other forms of domestic violence. Victims of the domestic disturbance were killed in 21% of the IPV-related LEO homicide cases as opposed to only 5% of other domestic disturbance calls. A firearm was the most common weapon used in the murder of a domestic disturbance victim (86%). This study describes domestic disturbance-related LEO homicides. Future research in this area should further examine the dangers unique to domestic disturbance calls. A longitudinal analysis could provide greater understanding of the injury and mortality risks faced by LEOs, in order to inform homicide prevention among law enforcement.

  9. Design of disturbances control model at automotive company

    Science.gov (United States)

    Marie, I. A.; Sari, D. K.; Astuti, P.; Teorema, M.

    2017-12-01

    The discussion was conducted at PT. XYZ which produces automotive components and motorcycle products. The company produced X123 type cylinder head which is a motor vehicle forming component. The disturbances in the production system has affected the company performance in achieving the target of Key Performance Indicator (KPI). Currently, the determination of the percentage of safety stock of cylinder head products is not in accordance to the control limits set by the company (60% - 80%), and tends to exceed the control limits that cause increasing the inventory wastage in the company. This study aims to identify the production system disturbances that occurs in the production process of manufacturing components of X123 type cylinder head products and design the control model of disturbance to obtain control action and determine the safety stock policy in accordance with the needs of the company. The design stage has been done based on the Disturbance Control Model which already existing and customized with the company need in controlling the production system disturbances at the company. The design of the disturbances control model consists of sub-model of the risk level of the disturbance, sub-model of action status, sub-model action control of the disturbance, and sub-model of determining the safety stock. The model can assist the automotive company in taking the decision to perform the disturbances control action in production system cylinder head while controlling the percentage of the safety stock.

  10. Menstruation and Menstrual Hygiene amongst Adolescent School ...

    African Journals Online (AJOL)

    Institutionalizing sexuality education in Nigerian schools; developing and disseminating sensitive adolescent reproductive health massages targeted at both parents and their adolescent children; and improving access of the adolescents to youth friendly services are veritable means of meeting the adolescent reproductive ...

  11. Quantification of disturbed coronary flow by disturbed vorticity index and relation with fractional flow reserve.

    Science.gov (United States)

    Chu, Miao; von Birgelen, Clemens; Li, Yingguang; Westra, Jelmer; Yang, Junqing; Holm, Niels R; Reiber, Johan H C; Wijns, William; Tu, Shengxian

    2018-02-16

    The relation between FFR and local coronary flow patterns is incompletely understood. We aimed at developing a novel hemodynamic index to quantify disturbed coronary flow, and to investigate its relationship with lesion-associated pressure-drop, and fractional flow reserve (FFR). Three-dimensional angiographic reconstruction and computational fluid dynamics were applied to simulate pulsatile coronary flow. Disturbed vorticity index (DVI) was derived to quantify the stenosis-induced flow disturbance. The relation between DVI and pressure-drop was assessed in 9 virtual obstruction models. Furthermore, we evaluated the correlation between DVI, FFR, hyperemic flow velocity, and anatomic parameters in 84 intermediate lesions from 73 patients. In virtual models, DVI increased with increasing flow rate, stenosis severity, and lesion complexity. The correlation between DVI and pressure-drop across all models was excellent (determination coefficient R 2  = 0.85, p flow velocity (ρ = -0.27, p=0.015), lesion length (ρ = -0.36, p=0.001) and percent diameter stenosis (ρ = -0.40, p flow, was related to pressure-drop in virtual obstruction models and showed a strong inverse relation with FFR in intermediate lesions in vivo. It supports the prognostic value of FFR and may provide additional information about sources of energy loss when measuring FFR. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Modeling aircraft noise induced sleep disturbance

    Science.gov (United States)

    McGuire, Sarah M.

    One of the primary impacts of aircraft noise on a community is its disruption of sleep. Aircraft noise increases the time to fall asleep, the number of awakenings, and decreases the amount of rapid eye movement and slow wave sleep. Understanding these changes in sleep may be important as they could increase the risk for developing next-day effects such as sleepiness and reduced performance and long-term health effects such as cardiovascular disease. There are models that have been developed to predict the effect of aircraft noise on sleep. However, most of these models only predict the percentage of the population that is awakened. Markov and nonlinear dynamic models have been developed to predict an individual's sleep structure during the night. However, both of these models have limitations. The Markov model only accounts for whether an aircraft event occurred not the noise level or other sound characteristics of the event that may affect the degree of disturbance. The nonlinear dynamic models were developed to describe normal sleep regulation and do not have a noise effects component. In addition, the nonlinear dynamic models have slow dynamics which make it difficult to predict short duration awakenings which occur both spontaneously and as a result of nighttime noise exposure. The purpose of this research was to examine these sleep structure models to determine how they could be altered to predict the effect of aircraft noise on sleep. Different approaches for adding a noise level dependence to the Markov Model was explored and the modified model was validated by comparing predictions to behavioral awakening data. In order to determine how to add faster dynamics to the nonlinear dynamic sleep models it was necessary to have a more detailed sleep stage classification than was available from visual scoring of sleep data. An automatic sleep stage classification algorithm was developed which extracts different features of polysomnography data including the

  13. Evolution of ionospheric disturbances excited by earthquakes

    Science.gov (United States)

    Astafyeva, Elvira; Heki, Kosuke; Afraimovich, Edward; Kiryushkin, Vladislav; Shalimov, Sergei

    Earthquakes are known to produce infrasonic pressure waves in the atmosphere. Because of the coupling between neutral particles and electrons at ionospheric altitudes, these acoustic and gravity waves induce variations of the ionospheric electron density. Using GPS total electron content (TEC) measurements we studied ionosphere response to the Kuril Islands Earthquakes of 04 October 1994 (M8.1) and 15 November 2006 (M7.9). High spatial resolution of the Japanese dense GPS array (GEONET) allowed us to analyze the dynamical characteristics of the observed traveling ionospheric disturbances (TIDs) in detail. This provided us more information about the processes of an atmospheric wave propagation and transformation from the ground to the ionosphere (i.e. transformation of acoustic waves to shock-acoustic waves, SAW) and then to TIDs propagating for more than 1800 km. Such observations of the evolution of disturbances in the ionosphere have been performed for the first time. The observed TIDs appeared in TEC records of the closest to the epicenter GPS receivers 10 min after the quake in the form of N-type wave as a response to propagation of SAW. The amplitude of the signal is about 0.6 TEC units for the records in the near-field ( 100-200 km) of the suspected TIDs source, and about 1 TEC units at a distance of 200-350 km. Within first 600 km the propagation velocity was about 1.3 km/s. Our results coincide with previous results of SAW investigations. We managed to track the subsequent evolution of the propagating TIDs: starting from 400- 500 km out of the source the wave seems to divide into two separate waves, which henceforth propagate with different velocities - about 1.7 km/s and 600 m/s. We suggest that the TEC response in the far field of the TIDs source is a mixture of the damping SAW (the "fast" wave) and TIDs propagating in the atmospheric waveguide (the "slow" wave). Other possibility is that the record shows a separation of the positive (the "fast" wave) and

  14. Intertidal soft-sediment community does not respond to disturbance as postulated by the intermediate disturbance hypothesis

    Science.gov (United States)

    Gerwing, Travis G.; Allen Gerwing, Alyssa M.; Macdonald, Tara; Cox, Kieran; Juanes, Francis; Dudas, Sarah E.

    2017-11-01

    The Intermediate Disturbance Hypothesis (IDH) predicts that disturbances of an intermediate frequency or intensity will maximize community biodiversity/richness. Once almost universally accepted, controversy now surrounds this hypothesis, and there have even been calls for its abandonment. Therefore, we experimentally evaluated if an infaunal community along the north coast of British Columbia, Canada, would respond to disturbances as predicted by the IDH. The characteristics of this soft-sediment intertidal mudflat (productivity, species pool, population growth rate) maximized our chances of finding evidence to support the IDH. More specifically, we tested if intermediate severities and frequencies of disturbance maximized infaunal community richness by mechanically disturbing sediment, and varying the intensity (0%, 25%, 50%, 75%, and 100% of the surface area of a plot disturbed) and frequency of sediment disturbance (never, once, twice, and every week during a four week period). No effect of frequency or intensity of sediment disturbance on community richness was observed. Further, none of our experimental treatments were statistically different than the controls. This is likely due to the subtle difference between successional stages in this soft-sediment habitat (difference of less than one taxa between treatments). Therefore, in habitats whose productivity, regional species pool, and population growth rates would otherwise suggest a response to disturbances as predicted by the IDH, minor differences between successional stages may result in richness patterns that deviate from those predicted by the IDH.

  15. Characterization of Forest Disturbance in California using Landsat Spectral Trajectories

    Science.gov (United States)

    Reents, C.; Greenberg, J. A.

    2015-12-01

    Natural and anthropogenic forest disturbances are a major contributor to global carbon fluxes, and can act as both a natural component of healthy ecosystem function and a threat to fragile ecosystems as well as human lives and property. The local and global impacts of a disturbance event depend in large part on the timing, intensity, and cause of the disturbance. With some disturbance types expected to increase in frequency and severity under the influence of climate change and increasing anthropogenic land use, knowledge of disturbance events and trends has become particularly crucial for a variety of scientific, political and management needs. Many studies have made use of time series analyses of multitemporal satellite imagery to study forest disturbance events at a variety of scales, but few have endeavored to attribute specific causal information to the disturbances detected, particularly at broad spatial and temporal scales. The purpose of this research is to investigate the suitability of a Landsat time series approach for detecting and describing causes of disturbance events across the heterogeneous, forested landscapes of California. Using existing GIS datasets detailing the locations of logging, fire, pest damage and land use conversion events statewide, we extracted the full Landsat time series (1984-2015) for six Landsat spectral bands at the location of each disturbance event. The characteristics of each time series vary depending on the nature of the disturbance occurring at that location. These differences can be harnessed as a way of differentiating disturbance types based on observed values before, during, and after the time of the event, which together comprise the disturbance's temporal signature. We applied a machine learning algorithm to these temporal signatures in order to construct a classification model linking disturbance type with the associated signature. We then applied this model to all forested areas in California using all Landsat 4

  16. Sleep disturbance in people with diabetes: A concept analysis.

    Science.gov (United States)

    Zhu, Bingqian; Vincent, Catherine; Kapella, Mary C; Quinn, Laurie; Collins, Eileen G; Ruggiero, Laurie; Park, Chang; Fritschi, Cynthia

    2018-01-01

    To clarify the meaning of sleep disturbance in people with diabetes and examine its antecedents, attributes and consequences through concept analysis. Sleep is crucial for health, and people with diabetes are frequently beset with disturbances in their sleep. The concept of sleep disturbance in people with diabetes has not been clearly defined. The inconsistent use of sleep disturbance has created confusion and impeded our understanding of the sleep in people with diabetes. This analysis will provide a conceptual foundation of sleep disturbance in diabetes, thereby facilitating more effective means for assessment and treatment. Concept analysis. A systematic search without time restriction on the publication year was carried out using PubMed, CINAHL, PsycINFO, Web of Science and ProQuest Dissertations and Theses. Rodgers's method of evolutionary concept analysis guided the analysis. Inductive thematic analysis was conducted to identify the attributes, antecedents and consequences. Based on the 26 eligible studies, two major attributes are that sleep disturbance is a symptom and is characterised by impaired sleep quality and/or abnormal sleep duration. Two antecedents are diabetes-related physiological change and psychological well-being. Sleep disturbance can result in impaired daytime functioning, glucose regulation and quality of life. Defining the concept of sleep disturbance in people with diabetes facilitates consistent use and effective communication in both practice and research. Sleep disturbance in people with diabetes is a complex symptom that includes impaired sleep quality and/or abnormal sleep duration. This paper contributes to the current knowledge of sleep in people with diabetes. Future research on antecedents and consequences of sleep disturbance is necessary for further clarifications. Findings from this paper underscore the need for nursing education, clinical assessment and effective management of sleep disturbance in people with diabetes.

  17. The French Sleep Disturbance Scale for Children.

    Science.gov (United States)

    Putois, Benjamin; Leslie, Wendy; Gustin, Marie Paule; Challamel, Marie-Josèphe; Raoux, Aude; Guignard-Perret, Anne; Weick, Diane; Sauzeau, Jean-Baptiste; Herbillon, Vania; Zourou, Filio; Spruyt, Karen; Franco, Patricia

    2017-04-01

    The psychometric properties of the Sleep Disturbance Scale for Children (SDSC) have been shown to be accurate, even when translated into several languages. The aim of the present study was to translate, adapt, and validate the SDSC for a French-speaking population. After forward- and back-translation, the tool was further translated and adapted into the French language. It was then pretested in terms of clarity on 33 French-speaking parents. Pretesting demonstrated that the questionnaire was well understood, indicating good clarity. During the validation phase, a total of 447 French-speaking parents of children aged between 4 and 16  years completed the SDSC. Among these, 66 children were diagnosed with sleep disorders by a pediatric specialist after a sleep consultation and polysomnographic recordings. The factor analysis revealed five factors: difficulty in initiating and maintaining sleep (DIMS), sleep breathing disorders (SBD), disorders of excessive somnolence (DOES), parasomnias (PARA) and non-restorative sleep (NRS). This psychometric structure is reliable and logical in comparison with the experts' diagnoses. Convergent validity, divergent and internal reliability are very good. Inter-parental concordance in scoring the child's sleep problem does show differences in the ways in which parents report their children's sleep patterns. Cut-off was calculated for the total score (45). This study validated a 25-item French version of the questionnaire. The French SDSC could therefore be used to aid screening of sleep disorders in the general population. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Late Holocene rainforest disturbance in French Guiana.

    Science.gov (United States)

    Ledru, M -P.

    2001-06-01

    Palm swamp forest sediments collected in French Guiana provide new data about late Holocene rainforest. Two cores were collected in 'Les Nouragues' ecological station (4 degrees 05'N, 52 degrees 40'W). The lithology shows two different types of sediment, organic peat in the upper part and oxidized clay with low organic content and lacking pollen in the lower part, both separated by a gravel horizon. Radiocarbon dates show that this gravel horizon could have been deposited between 4500 and 3000yrBP. Pollen analysis carried out on the organic sediments record rainforest disturbances between ca 1520-1380 and 1060-860cal yrBP suggested by the presence of the pioneer tree species Cecropia together with other shade intolerant genera. Cecropia is recorded for a period that lasts between 660 and 320 years. This abnormal duration for presence of a pioneer species in rainforest is explained by brief and repeated changes in the composition of the canopy asssociated to perturbations of the palm swamp.

  19. Eating disturbances among adolescent schoolgirls in Jordan.

    Science.gov (United States)

    Mousa, Tamara Yousef; Al-Domi, Hayder Abdullah; Mashal, Rima Hussein; Jibril, Musa Abdel-Khaleq

    2010-02-01

    Several studies indicated that the prevalence of eating disorders has increased among adolescent girls. The aim of the present study, therefore, is to investigate the occurrence and correlates of eating disorders among adolescent girls in Amman, Jordan. A sample of 432 adolescent girls aged 10-16 years were recruited from public and private schools in Amman. Information was collected from adolescent schoolgirls through a socio-demographic data sheet, eating attitude test, body shape and eating habits questionnaires. One third of participants had eating disorders, including bulimia nervosa (0.6%), binge eating disorder (1.8%) and eating disorder not otherwise specified (31%), however no anorexic cases were found. Findings also suggested that pubertal, familial and social variables were associated with eating disorders occurrence. Eating disturbances were prevalent among the present population sample. Participants have been more preoccupied with their body weight due to socio-cultural norms that are reinforced by media messages. Further research is needed to develop intervention programs to control eating disorders occurrence in Jordan. 2009 Elsevier Ltd. All rights reserved.

  20. The Shape of Strongly Disturbed Dayside Magnetopause

    Directory of Open Access Journals (Sweden)

    Alexei V. Dmitriev Alla V. Suvorova

    2013-01-01

    Full Text Available During strong geomagnetic disturbances, the Earth¡¦s magnetosphere exhibits unusual and nonlinear interaction with the incident flow of magnetized solar wind plasma. Global Magneto-hydro-dynamic (MHD modeling of the magnetosphere predicts that the storm-time effects at the magnetopause result from the abnormal plasma transport and/or extremely strong field aligned currents. In-situ observations of the magnetospheric boundary, magnetopause, by Geosynchronous Operational Environmental Satellite (GOES allowed us to find experimentally such effects as a saturation of the dayside reconnection, unusual bluntness and prominent duskward skewing of the nose magnetopause. The saturation and duskward skewing were attributed to the storm-time magnetopause formation under strong southward interplanetary magnetic field (IMF. The unusual bluntness was observed during both high solar wind pressure and strong southward IMF. We suggest that these phenomena are caused by a substantial contribution of the cross-tail current magnetic field and the hot magnetospheric plasma from the asymmetrical ring current into the pressure balance at the dayside magnetopause.

  1. Population Consequences of Acoustic Disturbance of Marine Mammals

    Science.gov (United States)

    2013-09-30

    and motivational interactions of coastal bottlenose dolphins (Tursiops truncatus) in the Moray Firth, Scotland, to assess the biological effects of...potential responses of species to disturbance and diverse human activities. OBJECTIVES 1. Explore how the U.S. National Research Council (NRC... dolphins (Tursiops spp.). The third meeting focused on how disturbance might affect northern right whales (Eubalaena glacialis). During the fourth

  2. Republication of "Toward an Acceptable Definition of Emotional Disturbance"

    Science.gov (United States)

    Algozzine, Bob; Schmid, Rex; Conners, Bob

    2017-01-01

    Most definitions of emotionally disturbed youngsters suggest that disturbances in the child's behavior patterns cause academic and social problems which affect the child and his peers. While the process of identification may be facilitated by operational criteria within a definition, these factors are noticeably absent from definitions of…

  3. Evaluating the Differential Treatment of Emotional Disturbance and Social Maladjustment

    Science.gov (United States)

    Theodore, Lea A.; Akin-Little, Angeleque; Little, Steven G.

    2004-01-01

    The vague and incomplete federal definition of emotional disturbance has caused a great deal of controversy and debate since the inception of Public Law 94-142. The lack of resolution among professionals attempting to elucidate the distinction between emotional disturbance and social maladjustment has resulted in continued conflict. Included in…

  4. Landscape level analysis of disturbance regimes in protected areas ...

    Indian Academy of Sciences (India)

    sensing and GIS techniques. Geospatial analysis of disturbance regimes indicates 61.75% of the total PAs are under moderate disturbance index followed by 28.64% and 9.61% under low and high, respectively. Among the 28 protected areas – National Chambal WLS, Jaisamand WLS, Kumbhalgarh WLS, Sawai.

  5. Clinical and biochemical characteristics of women with menstrual disturbance

    Directory of Open Access Journals (Sweden)

    Szu-Yu Shen

    2014-06-01

    Conclusion: The degree of menstrual disturbances does not correlate with the severity of insulin resistance and metabolic disturbances in women without excess levels of androgen. For women with normal prolactin levels, amenorrheic patients had significantly lower serum prolactin levels than oligomenorrheic patients.

  6. Plant hybridization: the role of human disturbance and biological invasion

    Science.gov (United States)

    Qinfeng Guo

    2014-01-01

    Aim Anderson & Stebbins (1954, Evolution, 8, 378–388) posited that human activities promote species hybridizations by creating opportunities for hybridization and new habitats for hybrids to persist through disturbances (i.e. the ‘disturbance hypothesis’). While the first part of this hypothesis appears to be well supported, the second part has...

  7. Children's Understanding of Their Emotionally Disturbed Peers: A Replication

    Science.gov (United States)

    Hoffman, Edward; And Others

    1977-01-01

    Despite increasing recognition of the early importance of peer relations, virtually no systematic information exists on the way in which normal children view their emotionally disturbed peers. This research reports a replication of recent findings on children's use of the concept of emotional disturbance. (Editor/RK)

  8. Agreeing in networks : Unmatched disturbances, algebraic constraints and optimality

    NARCIS (Netherlands)

    Monshizadeh, Nima; De Persis, Claudio

    This paper considers a problem of output agreement in heterogeneous networks with dynamics on the nodes as well as on the edges. The control and disturbance signals entering the nodal dynamics are "unmatched" meaning that some nodes are only subject to disturbances and not to the actuating signals.

  9. Output agreement in networks with unmatched disturbances and algebraic constraints

    NARCIS (Netherlands)

    Monshizadeh Naini, Nima; Persis, Claudio De

    2015-01-01

    This paper considers a problem of output agreement in heterogeneous networks with dynamics on the nodes as well as on the edges. The control and disturbance signals entering the nodal dynamics are "unmatched" meaning that some nodes are only subject to disturbances, and are deprived of actuating

  10. Review Personality disturbance in adolescents living with HIV/AIDS ...

    African Journals Online (AJOL)

    This paper presents a review of theoretical and empirical research on personality disturbance in adolescents living with HIV/AIDS. First we discuss the relationship between mental health in adolescents and HIV/AIDS, and second we provide an overview of personality disturbance in adolescence with particular attention ...

  11. Interactions between predation and disturbances shape prey communities.

    Science.gov (United States)

    Karakoç, Canan; Radchuk, Viktoriia; Harms, Hauke; Chatzinotas, Antonis

    2018-02-14

    Ecological disturbances are important drivers of biodiversity patterns. Many biodiversity studies rely on endpoint measurements instead of following the dynamics that lead to those outcomes and testing ecological drivers individually, often considering only a single trophic level. Manipulating multiple factors (biotic and abiotic) in controlled settings and measuring multiple descriptors of multi-trophic communities could enlighten our understanding of the context dependency of ecological disturbances. Using model microbial communities, we experimentally tested the effects of imposed disturbances (i.e. increased dilution simulating density-independent mortality as press or pulse disturbances coupled with resource deprivation) on bacterial abundance, diversity and community structure in the absence or presence of a protist predator. We monitored the communities immediately before and after imposing the disturbance and four days after resuming the pre-disturbance dilution regime to infer resistance and recovery properties. The results highlight that bacterial abundance, diversity and community composition were more affected by predation than by disturbance type, resource loss or the interaction of these factors. Predator abundance was strongly affected by the type of disturbance imposed, causing temporary relief of predation pressure. Importantly, prey community composition differed significantly at different phases, emphasizing that endpoint measurements are insufficient for understanding the recovery of communities.

  12. Characterizing sleeping habits and disturbances among Saudi adults.

    Science.gov (United States)

    Al-Tannir, Mohamad; Kobrosly, Samer Y; Al-Badr, Ahmad H; Salloum, Nourhan A; Altannir, Youssef M

    2016-12-01

    To characterize sleeping habits, assess sleep disturbance prevalence, and identify associated factors among Saudi adults.  Methods: A total of 1720 adults were approached for this observational cross-sectional study between October 2014 and March 2015. The study took place in Riyadh, the capital of Saudi Arabia. We used a questionnaire to describe sleeping characteristics in relation to existing chronic diseases, smoking status, obesity, daily performance and sociodemographic variables. Results: The response rate was 79.6% (1369 participants), 61.6% have or may have sleeping disturbances of which 18.6% claimed either slowed or stopped breathing during sleep. Women reported a higher prevalence of sleep disturbances (65.2%). Feeling tired was significantly associated with sleep disturbance (49% versus 19.7%) (p greater than 0.001). Approximately 78.4% of those with sleep disturbance significantly believed that their ability to perform daily tasks is affected (p=0.005). Moreover, smoking and obesity were significantly associated with sleep disturbances (p less than 0.01). Participants with asthma, hypertension, chronic heart disease, and diabetes mellitus reported significantly more sleeping disturbance (p=0.016 to p=0.001). Conclusions: Sleep disturbances are associated with obesity, smoking, chronic health conditions, and lower performance among  Saudi adults.

  13. Disturbance and Forest Health in Oregon and Washington.

    Science.gov (United States)

    Sally Campbell; Leon Liegel

    1996-01-01

    The scope and intensity of disturbance by such agents as fire, insects, diseases, air pollution, and weather in Pacific Northwest forests suggests that forest health has declined in recent years in many areas. The most significant disturbances and causes of tree mortality or decline in Oregon and Washington are presented and illustrated. We discuss the interrelations...

  14. Tracking and disturbance rejection for fully actuated mechanical systems

    NARCIS (Netherlands)

    Jayawardhana, Bayu; Weiss, George

    2008-01-01

    In this paper, we solve the tracking and disturbance rejection problem for fully actuated passive mechanical systems. We assume that the reference signal r and its first two derivatives r, r are available to the controller and the disturbance signal d can be decomposed into a finite superposition of

  15. Effect of supplemental Ascorbic acid and disturbance stress on the ...

    African Journals Online (AJOL)

    The study was conducted with four hundred day-old Anak broilers to determine the effects of dietary Ascorbic acid (AA) and disturbance (D) dress on the performance of broiler chickens in a tropical environment. There were four treatments consisting of two levels of disturbance (ID) and (4D) and two levels of dietary AA (0 ...

  16. Disturbance in forest ecosystems caused by pathogens and insects

    Science.gov (United States)

    Philip M. Wargo; Philip M. Wargo

    1995-01-01

    Pathogens and insects are major driving forces of processes in forested ecosystems. Disturbances caused by them are as intimately involved in ecosystem dynamics as the more sudden and obvious abiotic disturbances, for example, those caused by wind or fire. However, because pathogens and insects are selective and may affect only one or several related species of...

  17. Impact of global warming on cyclonic disturbances over south Asian ...

    Indian Academy of Sciences (India)

    Climate change; regional climate model; global warming; cyclonic disturbances; projections. ... Studies) developed by the Hadley Centre for Climate Prediction and Research, UK is applied over the Indian domain to investigate the impact of global warming on the cyclonic disturbances such as depressions and storms.

  18. Landscape level analysis of disturbance regimes in protected areas ...

    Indian Academy of Sciences (India)

    There is an urgent need to identify the human influence on landscape as disturbance regimes was realized for prioritization of the protected areas. The present study has attempted to describe the landscape level assessment of fragmentation and disturbance index in protected areas of Rajasthan using remote sensing and ...

  19. Natural disturbance impacts on Canada's forest carbon budget

    International Nuclear Information System (INIS)

    Kurz, W.

    2004-01-01

    Wildfire and insect outbreaks are major determinants of forest dynamics in Canada, transferring carbon within the ecosystem, releasing carbon into the atmosphere and influencing post-disturbance carbon dynamics. This paper discusses the impacts of global climate change on natural disturbances. Higher temperatures and drier conditions are likely to increase burned areas in Canada and will also increase the impacts of insects, allowing for an expanded range and stressing their host species. Long-term changes in disturbance regimes have already affected Canada's forest age-class structure. Statistics of lower disturbance periods and carbon production were compared with periods of higher disturbance. Scenario analyses were conducted for the period of 1996 to 2032, assuming that annual insect and fire disturbance rates in timber-productive forests were 20 per cent higher and carbon production 20 per cent lower than base scenarios using average disturbance rates. It was concluded that these conditions could cause carbon stocks in Canada's forests to decline. The future carbon balance of Canada's forests will be affected by the rate of natural and human-induced disturbances. 4 refs

  20. Development and Initial Validation of the Iowa Sleep Disturbances Inventory

    Science.gov (United States)

    Koffel, Erin; Watson, David

    2010-01-01

    The Iowa Sleep Disturbances Inventory (ISDI) is a new measure of self-reported sleep difficulties, which was designed to help facilitate research on the overlap of sleep disturbances and psychopathology. This instrument was developed in two large student samples using principal factor analyses; the psychometric properties of the scales were then…

  1. Sleep disturbance induces neuroinflammation and impairment of learning and memory.

    Science.gov (United States)

    Zhu, Biao; Dong, Yuanlin; Xu, Zhipeng; Gompf, Heinrich S; Ward, Sarah A P; Xue, Zhanggang; Miao, Changhong; Zhang, Yiying; Chamberlin, Nancy L; Xie, Zhongcong

    2012-12-01

    Hospitalized patients can develop cognitive function decline, the mechanisms of which remain largely to be determined. Sleep disturbance often occurs in hospitalized patients, and neuroinflammation can induce learning and memory impairment. We therefore set out to determine whether sleep disturbance can induce neuroinflammation and impairment of learning and memory in rodents. Five to 6-month-old wild-type C57BL/6J male mice were used in the studies. The mice were placed in rocking cages for 24 h, and two rolling balls were present in each cage. The mice were tested for learning and memory function using the Fear Conditioning Test one and 7 days post-sleep disturbance. Neuroinflammation in the mouse brain tissues was also determined. Of the Fear Conditioning studies at one day and 7 days after sleep disturbance, twenty-four hour sleep disturbance decreased freezing time in the context test, which assesses hippocampus-dependent learning and memory; but not the tone test, which assesses hippocampus-independent learning and memory. Sleep disturbance increased pro-inflammatory cytokine IL-6 levels and induced microglia activation in the mouse hippocampus, but not the cortex. These results suggest that sleep disturbance induces neuroinflammation in the mouse hippocampus, and impairs hippocampus-dependent learning and memory in mice. Pending further studies, these findings suggest that sleep disturbance-induced neuroinflammation and impairment of learning and memory may contribute to the development of cognitive function decline in hospitalized patients. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Thermally-Induced Structural Disturbances of Rigid Panel Solar Arrays

    Science.gov (United States)

    Johnston, John D.; Thornton, Earl A.

    1997-01-01

    The performance of a significant number of spacecraft has been impacted negatively by attitude disturbances resulting from thermally-induced motions of flexible structures. Recent examples of spacecraft affected by these disturbances include the Hubble Space Telescope (HST) and the Upper Atmosphere Research Satellite (UARS). Thermally-induced structural disturbances occur as the result of rapid changes in thermal loading typically initiated as a satellite exits or enters the Earth's shadow. Temperature differences in flexible appendages give rise to structural deformations, which in turn result in disturbance torques reacting back on the spacecraft. Structures which have proven susceptible to these disturbances include deployable booms and solar arrays. This paper investigates disturbances resulting from thermally-induced deformations of rigid panel solar arrays. An analytical model for the thermal-structural response of the solar array and the corresponding disturbance torque are presented. The effect of these disturbances on the attitude dynamics of a simple spacecraft is then investigated using a coupled system of governing equations which includes the effects of thermally-induced deformations. Numerical results demonstrate the effect of varying solar array geometry on the dynamic response of the system.

  3. Forest economics, natural disturbances and the new ecology

    Science.gov (United States)

    Thomas P. Holmes; Robert J. Huggett; John M. Pye

    2008-01-01

    The major thesis of this chapter is that the economic analysis of forest disturbances will be enhanced by linking economic and ecologic models. Although we only review a limited number of concepts drawn generally from mathematical and empirical ecology, the overarching theme we present is that ecological models of forest disturbance processes are complex and not...

  4. Characterizing sleeping habits and disturbances among Saudi adults

    Science.gov (United States)

    Al-Tannir, Mohamad A.; Kobrosly, Samer Y.; Al-Badr, Ahmad H.; Salloum, Nourhan A.; Altannir, Youssef M.; Sakkijha, Husam M.

    2016-01-01

    Objectives To characterize sleeping habits, assess sleep disturbance prevalence, and identify associated factors among Saudi adults. Methods A total of 1720 adults were approached for this observational cross-sectional study between October 2014 and March 2015. The study took place in Riyadh, the capital of Saudi Arabia. We used a questionnaire to describe sleeping characteristics in relation to existing chronic diseases, smoking status, obesity, daily performance and sociodemographic variables. Results The response rate was 79.6% (1369 participants), 61.6% have or may have sleeping disturbances of which 18.6% claimed either slowed or stopped breathing during sleep. Women reported a higher prevalence of sleep disturbances (65.2%). Feeling tired was significantly associated with sleep disturbance (49% versus 19.7%) (psleep disturbance significantly believed that their ability to perform daily tasks is affected (p=0.005). Moreover, smoking and obesity were significantly associated with sleep disturbances (psleeping disturbance (p=0.016 to p=0.001). Conclusions Sleep disturbances are associated with obesity, smoking, chronic health conditions, and lower performance among Saudi adults. PMID:27874154

  5. Sleep disturbance in patients with an implantable cardioverter defibrillator

    DEFF Research Database (Denmark)

    Habibović, M; Mudde, L; Pedersen, S S

    2018-01-01

    BACKGROUND: Sleep disturbances are highly prevalent in patients with cardiac diseases and associated with poor health outcomes. However, little is known about sleep disturbance in patients with an implantable cardioverter defibrillator. AIMS: We examined the prevalence and predictors of sleep...... disturbance and the impact on perceived health status in a Dutch cohort of implantable cardioverter defibrillator patients. METHODS: Patients ( n=195) enrolled in the Web-based distress program for implantable cardioverter defibrillator patients (WEBCARE) trial completed questionnaires at the time...... of implantable cardioverter defibrillator implantation, three, six and 12 months afterwards. Sleep disturbance was assessed with the corresponding item #3 of the Patient Health Questionnaire 9. RESULTS: At baseline, 67% ( n=130) reported sleep disturbance (cut off ≥1). One year later, the prevalence was 57% ( n...

  6. Model reduction of nonlinear systems subject to input disturbances

    KAUST Repository

    Ndoye, Ibrahima

    2017-07-10

    The method of convex optimization is used as a tool for model reduction of a class of nonlinear systems in the presence of disturbances. It is shown that under some conditions the nonlinear disturbed system can be approximated by a reduced order nonlinear system with similar disturbance-output properties to the original plant. The proposed model reduction strategy preserves the nonlinearity and the input disturbance nature of the model. It guarantees a sufficiently small error between the outputs of the original and the reduced-order systems, and also maintains the properties of input-to-state stability. The matrices of the reduced order system are given in terms of a set of linear matrix inequalities (LMIs). The paper concludes with a demonstration of the proposed approach on model reduction of a nonlinear electronic circuit with additive disturbances.

  7. Chronic stress, catecholamines, and sleep disturbance at Three Mile Island.

    Science.gov (United States)

    Davidson, L M; Fleming, R; Baum, A

    1987-01-01

    The present study was concerned with the relationship between chronic stress and sleep disturbance. Previous research has provided evidence of chronic stress responding among people living near the Three Mile Island nuclear generating facility. Compared to control subjects, the TMI group has exhibited greater symptom reporting, poorer performance on behavioral measures of concentration, and elevated levels of urinary norepinephrine and epinephrine. Other research has suggested a relationship between arousal and insomnia. The extent to which stress and sleep disturbances were experienced by residents at TMI was examined and compared to levels of stress and sleep disturbance among a group of control subjects. The relationship between stress and sleep disturbances was also examined. Results indicated that TMI area residents exhibited more stress than the controls and reported greater disturbance of sleep. Modest relationships among stress and sleep measures suggested that the symptoms of stress measured in this study were not primary determinants of sleep problems.

  8. Treatment of sleep disturbances in trauma-affected refugees

    DEFF Research Database (Denmark)

    Sandahl, Hinuga; Jennum, Poul; Baandrup, Lone

    2017-01-01

    Background: Sleep disturbances are often referred to as a hallmark and as core symptoms of post-traumatic stress disorder (PTSD). Untreated sleep disturbances can contribute to the maintenance and exacerbation of PTSD symptoms, which may diminish treatment response and constitute a risk factor...... for poor treatment outcome. Controlled trials on treatment of sleep disturbances in refugees suffering from PTSD are scarce. The present study aims to examine sleep-enhancing treatment in refugees with PTSD. We aim to assess if add-on treatment with mianserin and/or Imagery Rehearsal Therapy (IRT......) to treatment as usual (TAU) for PTSD improves sleep disturbances. We will study the relation between sleep disturbances, PTSD symptoms, psychosocial functioning and quality of life. Methods: The study is a randomised controlled superiority trial with a 2 × 2 factorial design. The study will include 230 trauma...

  9. Active disturbance rejection control for fractional-order system.

    Science.gov (United States)

    Li, Mingda; Li, Donghai; Wang, Jing; Zhao, Chunzhe

    2013-05-01

    Fractional-order proportional-integral (PI) and proportional-integral-derivative (PID) controllers are the most commonly used controllers in fractional-order systems. However, this paper proposes a simple integer-order control scheme for fractional-order system based on active disturbance rejection method. By treating the fractional-order dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. External disturbance, sensor noise, and parameter disturbance are also estimated using extended state observer. The ADRC stability of rational-order model is analyzed. Simulation results on three typical fractional-order systems are provided to demonstrate the effectiveness of the proposed method. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Chronic stress, catecholamines, and sleep disturbance at Three Mile Island

    International Nuclear Information System (INIS)

    Davidson, L.M.; Fleming, R.; Baum, A.

    1987-01-01

    The present study was concerned with the relationship between chronic stress and sleep disturbance. Previous research has provided evidence of chronic stress responding among people living near the Three Mile Island nuclear generating facility. Compared to control subjects, the TMI group has exhibited greater symptom reporting, poorer performance on behavioral measures of concentration, and elevated levels of urinary norepinephrine and epinephrine. Other research has suggested a relationship between arousal and insomnia. The extent to which stress and sleep disturbances were experienced by residents at TMI was examined and compared to levels of stress and sleep disturbance among a group of control subjects. The relationship between stress and sleep disturbances was also examined. Results indicated that TMI area residents exhibited more stress than the controls and reported greater disturbance of sleep. Modest relationships among stress and sleep measures suggested that the symptoms of stress measured in this study were not primary determinants of sleep problems

  11. Lichen Persistence and Recovery in Response to Varied Volcanic Disturbances

    Science.gov (United States)

    Nelson, P.; Wheeler, T. B.

    2015-12-01

    Volcanic eruptions produce many ecological disturbances that structure vegetation. While lichens are sensitive to disturbances, little is known about their responses to volcanic disturbances, except for colonization of lava. We examined lichen community responses through time to different disturbances produced by the May 1, 2008 eruption of Volcan Chaiten in south-central Chile. Pre-eruption vegetation near the volcano was old-growth Valdivian temperate rainforest dominated by closed-canopy Nothofagus sp... In 2012, we installed thirteen 1-acre plots across volcanic disturbance zones on which a time-constrained search was done for all macrolichen species, each of which was assigned an approximate log10 categorical abundance. We also installed a 0.2 m2 quadrat on two representative trees per plot for repeat photography of lichen cover. We remeasured at least one plot per disturbance zone in 2014 and re-photographed tree quadrats in 2013 and 2014. We then analyzed species composition and abundance differences among disturbance zones. In 2012, the blast (pyroclastic density flow), scorch (standing scorched forest at the edge of the blast) and deep tephra (>10 cm) zones had the lowest lichen species richness (5-13 species), followed by reference (unimpacted) and shallow (lichen species since 2012 while the light tephra and reference were essentially unchanged. Gravel rain, gravel rain + pumice and flooded forest plots all had about the same number of species in 2014 as 2012. Lichen colonization and growth in tree quadrats varied widely, from very little colonization in the blast to prolific colonization in the gravel rain + pumice zone. Lichen's varied responses to different volcanic disturbances were attributable to varying degrees of mortality and subsequent availability of substrate, quantity of light and removal of competitors. While sensitive to disturbance, lichens are apparently resilient to and can quickly recolonize after a variety of large, violent volcanic

  12. Age structure and disturbance legacy of North American forests

    Directory of Open Access Journals (Sweden)

    Y. Pan

    2011-03-01

    Full Text Available Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stocks and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a predictable pattern with forest recovery. Forest age, which is related to time since disturbance, is a useful surrogate variable for analyses of the impact of disturbance on forest carbon. In this study, we compiled the first continental forest age map of North America by combining forest inventory data, historical fire data, optical satellite data and the dataset from NASA's Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS project. A companion map of the standard deviations for age estimates was developed for quantifying uncertainty. We discuss the significance of the disturbance legacy from the past, as represented by current forest age structure in different regions of the US and Canada, by analyzing the causes of disturbances from land management and nature over centuries and at various scales. We also show how such information can be used with inventory data for analyzing carbon management opportunities. By combining geographic information about forest age with estimated C dynamics by forest type, it is possible to conduct a simple but powerful analysis of the net CO2 uptake by forests, and the potential for increasing (or decreasing this rate as a result of direct human intervention in the disturbance/age status. Finally, we describe how the forest age data can be used in large-scale carbon modeling, both for land-based biogeochemistry models and atmosphere-based inversion models, in order to improve the spatial accuracy of carbon cycle simulations.

  13. Solar Wind Disturbances Related to Geomagnetic Storms

    Science.gov (United States)

    Tan, A.; Lyatsky, W. B.

    2001-12-01

    We used the superposed epoch method to reconstruct a typical behavior of solar wind parameters before and during strong isolated geomagnetic storms. For this analysis we used 130 such geomagnetic storms during the period of 1966-2000. The results obtained show that a typical disturbance in the solar wind responsible for geomagnetic storm generation is associated with the propagation of high-speed plasma flow compressing ambient solar wind plasma and interplanetary magnetic field (IMF) ahead of this high-speed flow. This gives rise to enhanced magnetic field, plasma density, plasma turbulence and temperature, which start to increase several hours before geomagnetic storm onset. However, the IMF Bz (responsible for geomagnetic storm onset) starts to increase significantly later (approximately 6-7 hours after maximal variations in plasma density and IMF By). The time delay between peaks in IMF Bz and plasma density (and IMF By) may be a result of draping of high-speed plasma streams with ambient magnetic field in the (z-y) plane as discussed by some authors. This leads to an increase first in plasma density and IMF By ahead of a high-speed flow, which is followed by an increase in IMF Bz. This simple model allows us to predict that the probability for geomagnetic storm generation should depend on which edge of a high-speed flow encounters the Earth's magnetosphere. The probability for geomagnetic storm generation is expected to be maximal when the flow encounters the magnetosphere by its north-west edge for negative IMF By and south-west edge for positive IMF By.

  14. Hemorheological disturbances in the overtraining syndrome.

    Science.gov (United States)

    Varlet-Marie, Emanuelle; Maso, Freddy; Lac, Gérard; Brun, Jean-Frédéric

    2004-01-01

    Contemporary sports imply huge training volumes, with thus an increasing danger of overloading. The timely detection of the state of overloading in the organism as a whole or in skeletal muscles presents a difficult and complicated problem. A standardized questionnaire has been proposed by the French consensus group on overtraining of the Société Française de Médecine du Sport (SFMS) and allows the calculation of a "score" that may help to quantify the early clinical symptoms of the overtraining syndrome in sportsmen submitted to a heavy training program. We previously reported that this overtraining score is correlated with blood viscosity due to a correlation of this score with plasma viscosity and hematocrit. When subjects with a high score were compared to subjects with a lower score they appeared to have a higher blood viscosity at native (but not corrected) hematocrit, explained by higher values in both plasma viscosity and hematocrit. By contrast, there was no difference in RBC deformability and aggregation. Therefore, the early signs of overtraining in elite sportsmen are associated with a hemorheologic pattern that suggests some degree of reversal of the "autohemodilution" which characterizes fitness. In a further study we reported that the feeling of heavy legs in overtrained athletes is related to impaired hemorheology. Although well matched with controls for age and body composition, subjects with a complaint of heavy legs had higher plasma viscosity and a higher red cell aggregation as measured with laser backscattering. These findings suggest that the feeling of heavy legs in overtrained athletes are related to hemorheologic disturbances. In the light of the recent concept explaining this syndrome by a mild chronic inflammatory reaction, the investigation of hemorheology in overtraining can be a promising area for hemorheologists, providing both markers and likely pathophysiological explanations for some symptoms of this situation. Copyright 2004

  15. [Pain and sensory disturbance in Parkinson disease].

    Science.gov (United States)

    Yoshii, Fumihito

    2012-04-01

    Pain or sensory symptoms are a frequent complaint in Parkinson disease (PD), which reduce health-related quality of life (QOL) and interfere with patient's ability to participate in activities of daily living, thus contributing to sleep disturbance or major depression. The frequency of pain is thought to have a bimodal distribution. The initial peak seems to occur before, or at the onset of PD and a second peak occurs later in the disease course in conjunction with the development of motor fluctuations or dyskinesia. The spectrum of sensory symptoms is wide, and the most common sites that experience pain are the back, legs, and shoulders. In cases, pain occurs on the side that is more affected by parkinsonism; however unusual distributions, such as oral or genital pain syndrome, chest pain, and upper or lower abdominal discomfort may be observed. The etiological basis of PD-related pain is multifactorial, with varying degrees of contribution from peripheral and central sources. Central mechanisms include derangement of the intrinsic pain-modulating monoaminergic mechanism in addition to plastic central nervous system changes induced by chronic anti-parkinsonian medication. The importance of dopaminergic deficits as a causal factor in PD-related pain is supported by the normalization of these abnormalities after L-dopa administration, which suggests that the human striatum plays a central role in processing nociceptive information. Nevertheless, the lack of response to dopaminergic agents in some patients suggests the involvement of non-dopaminergic structures in PD. Abnormalities of noradrenergic and serotonergic pathways descending to the spinal cord are assumed to play a role in pain perception in PD. Some reports have highlighted the problem of delayed diagnosis in PD patients with an initial presentation of pain. Greater awareness of this possibility among physicians is important. Physicians also should bear in mind that psychological factors are major

  16. Travelling ionospheric disturbance over California mid 2000

    Directory of Open Access Journals (Sweden)

    M. Hawarey

    2006-01-01

    Full Text Available In this paper, the GPS data collected by more than 130 permanent GPS stations that belong to the Southern California Integrated GPS Network (SCIGN around the launch of a Minuteman-II missile on 8 July 2000 (UTC is processed to reveal traveling ionospheric disturbance (TID all over the network on average 15 min after the launch. This TID was initially perceived to be excited by the launch itself, but this conclusion is challenged by the propagation direction. This is because this TID seems to travel towards the air force base from where the launch took place, not far away from it. This challenge is based on the assumption that TID is occurring at one single ionospheric altitude. While the nature of ionosphere supports such horizontally-guided propagation, multi-altitude ionospheric pierce points are hypothesized, which would support the suggestion that detected TID is excited by the missile launch itself, despite the apparent reverse direction of propagation. The overall analysis rules out any extra-terrestrial sources like solar flares, or seismic sources like earthquakes, which confirms the conclusion of TID excitation by the launch. There is apparent coherence of the TID for about 45 min and the propagation speed of TID within the layer of ionosphere is calculated to be approximately equal to 1230 m/s. While the usual assumption for TID is that they occur around an altitude of 350 km, such sound speed can only occur at much higher altitudes. Further research is recommended to accurately pinpoint the ionospheric pierce points and develop an algorithm to locate the source of TID in case it is totally unknown.

  17. Disturbances observed near Ganymede by Voyager 2

    International Nuclear Information System (INIS)

    Burlaga, L.F.; Belcher, J.W.; Ness, N.F.

    1980-01-01

    We investigated disturbances in the field and particle environment observed by Voyager 2 as it passed near the Jovian moon Ganymede in Jupiter's magnetosphere. The plasma analyzer observed at least a dozen sharply bounded depressions in density (cavities). We estimated that they probably extended at least 20 RGAMMA along the ambient magnetic field lines (R/sub G/=2635 km is the radius of Ganymede) and between 2--50 R/sub G/ in the directions transverse to B. Depressions in the magnetic field strength of the order of 5% of the ambient field strength (60nT to 135nT) were observed at the boundaries of the cavities in more than half of the cases; they were probably produced by currents flowing transverse to B on the boundaries. In some cases, the magnetic field strength inside the cavities was a few percent higher than the ambient value. This gives an upper limit on β=nkT/(B 2 /8π) outside the cavities, viz. Beta 2.5 MeV protons was strongly anti-correlated with the plasma density, the flux being higher inside the cavities than outside. One possible mechanism for the production of these flux enhancements and the cavities themselves is a local, magnetic field-aligned electric field, E. It is possible that Ganymede is responsible for the energetic protons in the cavities, in which case vertical-bar E vertical-barapprox.50 mV/m. Such a localized source implies radial motions of the magnetospheric plasma with speeds of the order of a few hundred km/s. Such motions could be produced by long-wavelength, small-amplitude Alfven waves in Jupiter's magnetosphere

  18. Continuous uniformly finite time exact disturbance observer based control for fixed-time stabilization of nonlinear systems with mismatched disturbances.

    Science.gov (United States)

    Ni, Junkang; Liu, Chongxin; Liu, Hang

    2017-01-01

    This paper presents a continuous composite control scheme to achieve fixed-time stabilization for nonlinear systems with mismatched disturbances. The composite controller is constructed in two steps: First, uniformly finite time exact disturbance observers are proposed to estimate and compensate the disturbances. Then, based on adding a power integrator technique and fixed-time stability theory, continuous fixed-time stable state feedback controller and Lyapunov functions are constructed to achieve global fixed-time system stabilization. The proposed control method extends the existing fixed-time stable control results to high order nonlinear systems with mismatched disturbances and achieves global fixed-time system stabilization. Besides, the proposed control scheme improves the disturbance rejection performance and achieves performance recovery of nominal system. Simulation results are provided to show the effectiveness, the superiority and the applicability of the proposed control scheme.

  19. Disturbance and distributions: avoiding exclusion in a warming world

    Directory of Open Access Journals (Sweden)

    Douglas Sheil

    2016-03-01

    Full Text Available I highlight how disturbance determines species distributions and the implications for conservation practice. In particular, I describe opportunities to mitigate some of the threats to species resulting from climate change. Ecological theory shows that disturbance processes can often slow or prevent the exclusion of species by competitors and that different disturbance regimes result in different realized niches. There is much evidence of disturbance influencing where species occur. For example, disturbance can lower the high elevation treeline, thus expanding the area for high elevation vegetation that cannot otherwise persist under tree cover. The role of disturbance in influencing interspecific competition and resulting species persistence and distributions appears unjustly neglected. I identify various implications, including opportunities to achieve in situ conservation by expanding plant species ranges and reducing species vulnerability to competitive exclusion. Suitable frequencies, scales, intensities, spatial configurations, and timings of the right forms of disturbance can improve the persistence of targeted species in a wide range of contexts. Such options could reduce the extinctions likely to be associated with climate change. More generally, these mechanisms and the resulting realizable niche also offer novel insights to understanding and manipulating species distributions.

  20. Climate mediates the effects of disturbance on ant assemblage structure

    Science.gov (United States)

    Gibb, Heloise; Sanders, Nathan J.; Dunn, Robert R.; Watson, Simon; Photakis, Manoli; Abril, Silvia; Andersen, Alan N.; Angulo, Elena; Armbrecht, Inge; Arnan, Xavier; Baccaro, Fabricio B.; Bishop, Tom R.; Boulay, Raphael; Castracani, Cristina; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A.; Enríquez, Martha L.; Fayle, Tom M.; Feener, Donald H.; Fitzpatrick, Matthew C.; Gómez, Crisanto; Grasso, Donato A.; Groc, Sarah; Heterick, Brian; Hoffmann, Benjamin D.; Lach, Lori; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Majer, Jonathan; Menke, Sean B.; Mezger, Dirk; Mori, Alessandra; Munyai, Thinandavha C.; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M.; de Souza, Jorge L. P.; Tista, Melanie; Vasconcelos, Heraldo L.; Vonshak, Merav; Parr, Catherine L.

    2015-01-01

    Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 9°C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk. PMID:25994675

  1. Anthropogenic disturbance equalizes diversity levels in arbuscular mycorrhizal fungal communities.

    Science.gov (United States)

    García de León, David; Davison, John; Moora, Mari; Öpik, Maarja; Feng, Huyuan; Hiiesalu, Inga; Jairus, Teele; Koorem, Kadri; Liu, Yongjun; Phosri, Cherdchai; Sepp, Siim-Kaarel; Vasar, Martti; Zobel, Martin

    2018-03-24

    The arbuscular mycorrhizal (AM) symbiosis is a key plant-microbe interaction in sustainable functioning ecosystems. Increasing anthropogenic disturbance poses a threat to AM fungal communities worldwide, but there is little empirical evidence about its potential negative consequences. In this global study we sequenced AM fungal DNA in soil samples collected from pairs of natural (undisturbed) and anthropogenic (disturbed) plots in two ecosystem types (ten naturally wooded and six naturally unwooded ecosystems). We found that ecosystem type had stronger directional effects than anthropogenic disturbance on AM fungal alpha and beta diversity. However, disturbance increased alpha and beta diversity at sites where natural diversity was low, and decreased diversity at sites where natural diversity was high. Cultured AM fungal taxa were more prevalent in anthropogenic than natural plots, probably due to their efficient colonization strategies and ability to recover from disturbance. We conclude that anthropogenic disturbance does not have a consistent directional effect on AM fungal diversity; rather, disturbance equalizes levels of diversity at large scales and causes changes in community functional structure. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Purpose in life and incidence of sleep disturbances.

    Science.gov (United States)

    Kim, Eric S; Hershner, Shelley D; Strecher, Victor J

    2015-06-01

    Purpose in life has been linked with better mental health, physical health, and health behaviors, but the association between purpose and sleep is understudied. Sleep disturbances increase with age and as the number of older adults rapidly increases, it is ever more important to identify modifiable factors that are associated with reduced incidence of sleep disturbances. We used multiple logistic regression models and data from the Health and Retirement Study, a nationally representative panel study of American adults over the age of 50, to examine whether higher purpose was linked with a reduced incidence of sleep disturbances. Among 4144 respondents reporting minimal or no sleep disturbances at baseline, higher purpose was associated with a lower incidence of sleep disturbances over the 4-year follow-up. After adjusting for sociodemographic factors, each unit increase in purpose (on a six-point scale) was associated with a 16 % reduced odds of developing sleep disturbances (OR 0.84, 95 % CI 0.77-0.92). The association between purpose and sleep disturbances remained after adjusting for sociodemographic, behavioral, psychological, and health covariates. Should future research replicate our findings, this area of research may lead to innovative efforts that improve the quality of sleep in older adults.

  3. Wildfire disturbance impacts on streamflow from western USA watersheds

    Science.gov (United States)

    Cadol, D.; Wine, M.; Makhnin, O.

    2017-12-01

    Worldwide rapid changes in climate overlaid on changing land management paradigms have dramatically altered ecological disturbance regimes worldwide including in western North America. Ecological disturbances impacted include woody encroachment, pest pathogen complexes, riparian forest changes, and wildfire. These disturbances impact the hydrologic cycle, though the nature of these impacts has been difficult to quantify. Perhaps the greatest challenge is that most basins worldwide are ungauged. Taking wildfire as a globally relevant example of a key ecological disturbance, even within gauged basins, post-wildfire hydrologic response is spatially and temporally variable, affected by a host of variables including fire frequency, area burned, and recovery trajectory. Hydrologic response to wildfire is further understood to be a non-linear function of watershed characteristics and climate. Here we provide a framework that utilizes remote sensing, statistical modeling, field measurements, and geospatial methods to provide first-order estimates of ecological disturbance hydrologic impacts. We apply this framework to compare ecological disturbance hydrologic impacts amongst selected watersheds in the western USA. Here we show that ecological disturbance impacts on hydrology are highly variable, and in many cases have an effect magnitude similar to that modeled for temperature and precipitation changes.

  4. Sleep disturbance at simulated altitude indicated by stratified respiratory disturbance index but not hypoxic ventilatory response.

    Science.gov (United States)

    Kinsman, Tahnee A; Townsend, Nathan E; Gore, Christopher J; Hahn, Allan G; Clark, Sally A; Aughey, Robert J; McKenna, Michael J; Hawley, John A; Chow, Chin-Moi

    2005-08-01

    At high altitudes, the clinically defined respiratory disturbance index (RDI) and high hypoxic ventilatory response (HVR) have been associated with diminished sleep quality. Increased RDI has also been observed in some athletes sleeping at simulated moderate altitude. In this study, we investigated relationships between the HVR of 14 trained male endurance cyclists with variable RDI and sleep quality responses to simulated moderate altitude. Blood oxygen saturation (SpO2%), heart rate, RDI, arousal rate, awakenings, sleep efficiency, rapid eye movement (REM) sleep, non-REM sleep stages 1, 2 and slow wave sleep as percentages of total sleep time (%TST) were measured for two nights at normoxia of 600 m and one night at a simulated altitude of 2,650 m. HVR and RDI were not significantly correlated with sleep stage, arousal rate or awakening response to nocturnal simulated altitude. SpO2 was inversely correlated with total RDI (r = -0.69, P = 0.004) at simulated altitude and with the change in arousal rate from normoxia (r = -0.65, P = 0.02). REM sleep response to simulated altitude correlated with the change, relative to normoxia, in arousal (r = -0.63, P = 0.04) and heart rate (r = -0.61, P = 0.04). When stratified, those athletes at altitude with RDI >20 h(-1) (n = 4) and those with sleep or arousal increase. However, the stratified RDI provides a basis for determining potential sleep disturbance in athletes at simulated moderate altitude.

  5. Geomagnetic response to solar and interplanetary disturbances

    Directory of Open Access Journals (Sweden)

    Maris Georgeta

    2013-07-01

    Full Text Available The space weather discipline involves different physical scenarios, which are characterised by very different physical conditions, ranging from the Sun to the terrestrial magnetosphere and ionosphere. Thanks to the great modelling effort made during the last years, a few Sun-to-ionosphere/thermosphere physics-based numerical codes have been developed. However, the success of the prediction is still far from achieving the desirable results and much more progress is needed. Some aspects involved in this progress concern both the technical progress (developing and validating tools to forecast, selecting the optimal parameters as inputs for the tools, improving accuracy in prediction with short lead time, etc. and the scientific development, i.e., deeper understanding of the energy transfer process from the solar wind to the coupled magnetosphere-ionosphere-thermosphere system. The purpose of this paper is to collect the most relevant results related to these topics obtained during the COST Action ES0803. In an end-to-end forecasting scheme that uses an artificial neural network, we show that the forecasting results improve when gathering certain parameters, such as X-ray solar flares, Type II and/or Type IV radio emission and solar energetic particles enhancements as inputs for the algorithm. Regarding the solar wind-magnetosphere-ionosphere interaction topic, the geomagnetic responses at high and low latitudes are considered separately. At low latitudes, we present new insights into temporal evolution of the ring current, as seen by Burton’s equation, in both main and recovery phases of the storm. At high latitudes, the PCC index appears as an achievement in modelling the coupling between the upper atmosphere and the solar wind, with a great potential for forecasting purposes. We also address the important role of small-scale field-aligned currents in Joule heating of the ionosphere even under non-disturbed conditions. Our scientific results in

  6. Prevalence of sleep disturbance in chronic pain.

    Science.gov (United States)

    Karaman, S; Karaman, T; Dogru, S; Onder, Y; Citil, R; Bulut, Y E; Tapar, H; Sahin, A; Arici, S; Kaya, Z; Suren, M

    2014-01-01

    Sleep is a vital function for human beings, which can be affected by several factors. Chronic pain is one of these factors where it is the most frequent cause for seeking medical care in combination with insomnia. The aim of this study is to examine the prevalence and relationship between sleep disturbance and chronic pain. After approval, a total of 85 Family Medicine Units from over 170 in Tokat were randomly selected using a 50% sampling. A sample of 2635 subjects, over the age of 19 years, who were registered with the selected Family Medicine Units, were assessed due to gender, age group, and the urban/rural population size of Tokat using the stratified sampling method. The sample size distribution was calculated as 1515 urban subjects, 1120 rural subjects; 1345 female subjects, 1290 male subjects; 1123 subjects between 20-39 years of age, 1103 subjects between the ages of 40-64, and 409 subjects over 64 years of age. After sampling, subjects were invited to participate in the study via an invitation letter, and agreeing individuals were taken to the Family Medicine Unit for face-to-face meetings. Written, informed consent was obtained, along with demographic data. The presence of chronic pain was recorded. According to the presence of chronic pain, all subjects were separated into two groups as Group Chronic Pain and Group Non-Chronic Pain. The visual analog scale for pain intensity, and Pittsburgh Sleep Quality Index for sleep quality, were performed with all subjects. A multiple linear regression model was used to assess the predictors of sleep quality. Analyses were conducted using the Statistical Package for Social Sciences program (SPSS Inc., Chicago, IL, USA), version 20.0. The statistical significance for all analyses was set at p 5. A moderate positive correlation was found between the global Pittsburgh Sleep Quality Index and Visual Analog Scale scores (r = 0.310, p < 0.01). A multiple linear regression analysis showed that age, gender, income, Visual

  7. Flow disturbances generated by feeding and swimming zooplankton

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, Haisong; Goncalves, R. J.

    2014-01-01

    to minimize the fluid disturbance that they produce. By means of particle image velocimetry, we describe the fluid disturbances produced by feeding and swimming in zooplankton with diverse propulsion mechanisms and ranging from 10-µm flagellates to greater than millimeter-sized copepods. We show...... that zooplankton, in which feeding and swimming are separate processes, produce flow disturbances during swimming with a much faster spatial attenuation (velocity u varies with distance r as u ∝ r−3 to r−4) than that produced by zooplankton for which feeding and propulsion are the same process (u ∝ r−1 to r−2...

  8. Quantum Kolmogorov Complexity and Information-Disturbance Theorem

    Directory of Open Access Journals (Sweden)

    Takayuki Miyadera

    2011-03-01

    Full Text Available In this paper, a representation of the information-disturbance theorem based on the quantum Kolmogorov complexity that was defined by P. Vit´anyi has been examined. In the quantum information theory, the information-disturbance relationship, which treats the trade-off relationship between information gain and its caused disturbance, is a fundamental result that is related to Heisenberg’s uncertainty principle. The problem was formulated in a cryptographic setting and the quantitative relationships between complexities have been derived.

  9. ALSAN - A system for disturbance analysis by process computers

    International Nuclear Information System (INIS)

    Felkel, L.; Grumbach, R.

    1977-05-01

    The program system ALSAN has been developed to process the large number of signals due to a disturbance in a complex technical process, to recognize the important (in order to settle the disturbance within a minimum amount of time) information, and to display it to the operators. By means of the results, clear decisions can be made on what counteractions have to be taken. The system works in on-line-open-loop mode, and analyses disturbances autonomously as well as in dialog with the operators. (orig.) [de

  10. Active Disturbance Rejection Control of a Heat Integrated Distillation Column

    DEFF Research Database (Denmark)

    Al-Kalbani, Fahad; Zhang, Jie; Bisgaard, Thomas

    2016-01-01

    -toluene mixture. The efficiency of the ADRC technique is demonstrated by comparing with the conventional PI controller in terms of set-point trackingand external disturbance rejection capability. The results show that the ADRC gives much improved control performance than the PID control....... pressure. However, the control of some HiDC processesis generally difficult due to the strong control loop interaction, high purity of the components and undesired disturbances. Active disturbance rejection control (ADRC) is used in this paperto control a simulated HiDC for separating benzene...

  11. A succession of theories: purging redundancy from disturbance theory.

    Science.gov (United States)

    Pulsford, Stephanie A; Lindenmayer, David B; Driscoll, Don A

    2016-02-01

    The topics of succession and post-disturbance ecosystem recovery have a long and convoluted history. There is extensive redundancy within this body of theory, which has resulted in confusion, and the links among theories have not been adequately drawn. This review aims to distil the unique ideas from the array of theory related to ecosystem change in response to disturbance. This will help to reduce redundancy, and improve communication and understanding between researchers. We first outline the broad range of concepts that have developed over the past century to describe community change in response to disturbance. The body of work spans overlapping succession concepts presented by Clements in 1916, Egler in 1954, and Connell and Slatyer in 1977. Other theories describing community change include state and transition models, biological legacy theory, and the application of functional traits to predict responses to disturbance. Second, we identify areas of overlap of these theories, in addition to highlighting the conceptual and taxonomic limitations of each. In aligning each of these theories with one another, the limited scope and relative inflexibility of some theories becomes apparent, and redundancy becomes explicit. We identify a set of unique concepts to describe the range of mechanisms driving ecosystem responses to disturbance. We present a schematic model of our proposed synthesis which brings together the range of unique mechanisms that were identified in our review. The model describes five main mechanisms of transition away from a post-disturbance community: (i) pulse events with rapid state shifts; (ii) stochastic community drift; (iii) facilitation; (iv) competition; and (v) the influence of the initial composition of a post-disturbance community. In addition, stabilising processes such as biological legacies, inhibition or continuing disturbance may prevent a transition between community types. Integrating these six mechanisms with the functional

  12. Finite-state transition system analysis of disturbed foundation stiffness

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2018-01-01

    Foundations erected in sand can become disturbed during dynamic loading, as sand stiffness can both increase and decrease episodically. Paradigms outside geotechnics analyze similar problems as finite-state transition systems. Therefore, patterns governing disturbed foundation stiffness change......, the unconventional analysis technique delivers substantial descriptive and predictive power. To demonstrate the utility, stiffness of a foundation prototype is manipulated: during real-life, real-time testing, the initial stiffness path is disturbed and recovered 5 times in one loading sequence. Thus, the "memory...

  13. Nonlinear Disturbance Observer Based Robust Tracking Control of Pneumatic Muscle

    Directory of Open Access Journals (Sweden)

    Youssif Mohamed Toum Elobaid

    2014-01-01

    Full Text Available Presently pneumatic muscles (PMs are used in various applications due to their simple construction, lightweight, and high force-to-weight ratio. However, pneumatic muscles are facing various problems due to their nonlinear characteristics and various uncertainties in real applications. To cope with the uncertainties and strong nonlinearity of a PM model, a nonlinear disturbance observer (NDO is designed to estimate the lumped disturbance. Based on the disturbance observer, the tracking control of PM is studied. Stability analysis based on Lyapunov method with respect to our proposed control law is discussed. The simulation results show the validity, effectiveness, and enhancing robustness of the proposed methods.

  14. Temporal and spatial evolution characteristics of disturbance wave in a hypersonic boundary layer due to single-frequency entropy disturbance.

    Science.gov (United States)

    Wang, Zhenqing; Tang, Xiaojun; Lv, Hongqing; Shi, Jianqiang

    2014-01-01

    By using a high-order accurate finite difference scheme, direct numerical simulation of hypersonic flow over an 8° half-wedge-angle blunt wedge under freestream single-frequency entropy disturbance is conducted; the generation and the temporal and spatial nonlinear evolution of boundary layer disturbance waves are investigated. Results show that, under the freestream single-frequency entropy disturbance, the entropy state of boundary layer is changed sharply and the disturbance waves within a certain frequency range are induced in the boundary layer. Furthermore, the amplitudes of disturbance waves in the period phase are larger than that in the response phase and ablation phase and the frequency range in the boundary layer in the period phase is narrower than that in these two phases. In addition, the mode competition, dominant mode transformation, and disturbance energy transfer exist among different modes both in temporal and in spatial evolution. The mode competition changes the characteristics of nonlinear evolution of the unstable waves in the boundary layer. The development of the most unstable mode along streamwise relies more on the motivation of disturbance waves in the upstream than that of other modes on this motivation.

  15. Automated attribution of remotely-sensed ecological disturbances using spatial and temporal characteristics of common disturbance classes.

    Science.gov (United States)

    Cooper, L. A.; Ballantyne, A.

    2017-12-01

    Forest disturbances are critical components of ecosystems. Knowledge of their prevalence and impacts is necessary to accurately describe forest health and ecosystem services through time. While there are currently several methods available to identify and describe forest disturbances, especially those which occur in North America, the process remains inefficient and inaccessible in many parts of the world. Here, we introduce a preliminary approach to streamline and automate both the detection and attribution of forest disturbances. We use a combination of the Breaks for Additive Season and Trend (BFAST) detection algorithm to detect disturbances in combination with supervised and unsupervised classification algorithms to attribute the detections to disturbance classes. Both spatial and temporal disturbance characteristics are derived and utilized for the goal of automating the disturbance attribution process. The resulting preliminary algorithm is applied to up-scaled (100m) Landsat data for several different ecosystems in North America, with varying success. Our results indicate that supervised classification is more reliable than unsupervised classification, but that limited training data are required for a region. Future work will improve the algorithm through refining and validating at sites within North America before applying this approach globally.

  16. Reaction Wheel Disturbance Model Extraction Software, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel disturbances are some of the largest sources of noise on sensitive telescopes. Such wheel-induced mechanical noises are not well characterized....

  17. Disturbed sleep and diabetes: A potential nexus of dementia risk.

    Science.gov (United States)

    Holingue, Calliope; Wennberg, Alexandra; Berger, Slava; Polotsky, Vsevolod Y; Spira, Adam P

    2018-02-01

    Type 2 diabetes (T2D) and sleep disturbance (e.g., insomnia, sleep-disordered breathing) are prevalent conditions among older adults that are associated with cognitive decline and dementia, including Alzheimer's disease (AD). Importantly, disturbed sleep is associated with alterations in insulin sensitivity and glucose metabolism, and may increase the risk of T2D, and T2D-related complications (e.g., pain, nocturia) can negatively affect sleep. Despite these associations, little is known about how interactions between T2D and sleep disturbance might alter cognitive trajectories or the pathological changes that underlie dementia. Here, we review links among T2D, sleep disturbance, cognitive decline and dementia-including preclinical and clinical AD-and identify gaps in the literature, that if addressed, could have significant implications for the prevention of poor cognitive outcomes. Copyright © 2018. Published by Elsevier Inc.

  18. Analytical Assessment for Transient Stability Under Stochastic Continuous Disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Ping [Hohai Univ., Nanjing (China); Li, Hongyu [Hohai Univ., Nanjing (China); Gan, Chun [The Univ. of Tennessee, Knoxville, TN (United States); Liu, Yong [The Univ. of Tennessee, Knoxville, TN (United States); Yu, Yiping [Hohai Univ., Nanjing (China); Liu, Yilu [Univ. of Tennessee, Knoxville, TN (United States)

    2017-06-28

    Here, with the growing integration of renewable power generation, plug-in electric vehicles, and other sources of uncertainty, increasing stochastic continuous disturbances are brought to power systems. The impact of stochastic continuous disturbances on power system transient stability attracts significant attention. To address this problem, this paper proposes an analytical assessment method for transient stability of multi-machine power systems under stochastic continuous disturbances. In the proposed method, a probability measure of transient stability is presented and analytically solved by stochastic averaging. Compared with the conventional method (Monte Carlo simulation), the proposed method is many orders of magnitude faster, which makes it very attractive in practice when many plans for transient stability must be compared or when transient stability must be analyzed quickly. Also, it is found that the evolution of system energy over time is almost a simple diffusion process by the proposed method, which explains the impact mechanism of stochastic continuous disturbances on transient stability in theory.

  19. Impact of global warming on cyclonic disturbances over south Asian ...

    Indian Academy of Sciences (India)

    Providing REgional Climates for Impacts Studies) developed by the Hadley Centre for Climate Prediction and Research, UK is applied over the Indian domain to investigate the impact of global warming on the cyclonic disturbances such as ...

  20. Impact of global warming on cyclonic disturbances over south Asian ...

    Indian Academy of Sciences (India)

    Providing REgional Climates for Impacts Studies) developed by the Hadley Centre for Climate Prediction and Research, UK is applied over the Indian domain to investigate the impact of global warming on the cyclonic disturbances such.

  1. [Urodynamic disturbances among children with vesico-ureteral reflux (VUR)].

    Science.gov (United States)

    Piechuta, Leszek; Bieniaś, Beata; Wieczorkiewicz-Płaza, Anna; Borzecka, Halina; Zajaczkowska, Małgorzata

    2008-01-01

    Lower urinary tract dysfunction plays significant role in patogenesis of vesicoureteral reflux (VUR). Thus, urodynamic assessment is very useful in diagnosis and treatment of VUR. Assessment of the incidence of urodynamic disturbances among children with VUR. Retrospective assessment of 125 children with VUR including 93 assessed urodymically. Urodynamic disturbances were found in 58 patients (70.9% of examined children), of which--detrussor hyperactivity in 25 (43.1% of children with urodynamic disturbances), detrussor hyperactivity with subvesical obstruction or dysfunctional voiding in 6 (10.3%), dysfunctional voiding in 17 (29.3%), anatomical subvesical obstruction in 9 (15.5%), detrussor hypotony in 1 (1.7%). No disturbances were found in 27 (29.1% of examined children). Children with detrussor overactivity were the prevalent group among all children with lower urinary tract dysfunction. Children with lower urinary tract dysfunction constitute a significant part of children with VUR.

  2. Robust Helicopter Stabilization in the Face of Wind Disturbance

    DEFF Research Database (Denmark)

    A. Danapalasingam, Kumeresan; Leth, John-Josef; la Cour-Harbo, Anders

    2010-01-01

    When a helicopter is required to hover with minimum deviations from a desired position without measurements of an affecting persistent wind disturbance, a robustly stabilizing control action is vital. In this paper, the stabilization of the position and translational velocity of a nonlinear...... helicopter model affected by a wind disturbance is addressed. The wind disturbance is assumed to be a sum of a fixed number of sinusoids with unknown amplitudes, frequencies and phases. An estimate of the disturbance is introduced to be adapted using state measurements for control purposes. A nonlinear...... controller is then designed based on nonlinear adaptive output regulations and robust stabilization of a chain of integrators by a saturated feedback. Simulation results show the effectiveness of the control design in the stabilization of helicopter motion and the built-in robustness of the controller...

  3. Self-regulation strategies of children with emotional disturbance.

    Science.gov (United States)

    Barnes, Karin J; Vogel, Kimberly A; Beck, Alison J; Schoenfeld, Heidi B; Owen, Steven V

    2008-01-01

    Children with emotional disturbance frequently have difficulty regulating their classroom behaviors. Many have co-occurrence of other disabilities, such as sensory processing problems, which compound difficulties in school participation. This exploratory project evaluated the 8-week-long use of the Alert Program within the classroom setting for seven children with emotional disturbance. Five children with emotional disturbance served as a control group. Self-regulation, behavioral adjustments, and sensory processing skills as reported by the children and teachers were evaluated. Changes from pretest to posttest indicated that children who received the Alert Program demonstrated a small improvement on all measures while performance of the control group remained relatively constant or decreased. These preliminary results indicate programs that target self-regulation skills may be useful in helping to improve self-regulation of children with emotional disturbance.

  4. Neural Network Based Indexing and Recognition of Power Quality Disturbances

    Directory of Open Access Journals (Sweden)

    Ram Awtar Gupta

    2011-08-01

    Full Text Available Power quality (PQ analysis has become imperative for utilities as well as for consumers due to huge cost burden of poor power quality. Accurate recognition of PQ disturbances is still a challenging task, whereas methods for its indexing are not much investigated yet. This paper expounds a system, which includes generation of unique patterns called signatures of various PQ disturbances using continuous wavelet transform (CWT and recognition of these signatures using feed-forward neural network. It is also corroborated that the size of signatures of PQ disturbances are proportional to its magnitude, so this feature of the signature is used for indexing the level of PQ disturbance in three sub-classes viz. high, medium, and low. Further, the effect of number of neurons used by neural network on the performance of recognition is also analyzed. Almost 100% accuracy of recognition substantiates the effectiveness of the proposed system.

  5. BIM and GIS for low-disturbance construction

    NARCIS (Netherlands)

    Sebastian, R.; Böhms, H.M.; Helm, P.W. van den

    2013-01-01

    Construction and maintenance activities of bridges often bring negative impacts to the urban environment in terms of disturbance, traffic jams and disruptions, noise, dust, and air pollution. Lack of coordination between the stakeholders in strategic, tactical and operational construction planning

  6. Combining Radar and Optical Data for Forest Disturbance Studies

    Science.gov (United States)

    Ranson, K. Jon; Smith, David E. (Technical Monitor)

    2002-01-01

    Disturbance is an important factor in determining the carbon balance and succession of forests. Until the early 1990's researchers have focused on using optical or thermal sensors to detect and map forest disturbances from wild fires, logging or insect outbreaks. As part of a NASA Siberian mapping project, a study evaluated the capability of three different radar sensors (ERS, JERS and Radarsat) and an optical sensor (Landsat 7) to detect fire scars, logging and insect damage in the boreal forest. This paper describes the data sets and techniques used to evaluate the use of remote sensing to detect disturbance in central Siberian forests. Using images from each sensor individually and combined an assessment of the utility of using these sensors was developed. Transformed Divergence analysis and maximum likelihood classification revealed that Landsat data was the single best data type for this purpose. However, the combined use of the three radar and optical sensors did improve the results of discriminating these disturbances.

  7. Statistical Control Paradigm for Aerospace Structures Under Impulsive Disturbances

    National Research Council Canada - National Science Library

    Pham, Khanh D; Robertson, Lawrence M

    2006-01-01

    In this paper, the newly developed statistical control theory is revisited to autonomously control the satellite attitude as well as to provide a means of actively attenuating impulsive disturbances...

  8. Association of Sleep Disturbances With Reduced Semen Quality

    DEFF Research Database (Denmark)

    Jensen, Tina Kold; Andersson, Anna-Maria; Skakkebæk, Niels Erik

    2013-01-01

    Several studies have found an association between sleep duration and morbidity and mortality, but no previous studies have examined the association between sleep disturbances and semen quality. We conducted a cross-sectional study among 953 young Danish men from the general population who were...... recruited in Copenhagen at the time of determination of fitness for military service between January 2008 and June 2011. All of the men delivered a semen sample, had a blood sample drawn, underwent a physical examination, and answered a questionnaire including information about sleep disturbances. Sleep...... disturbances were assessed on the basis of a modified 4-item version of the Karolinska Sleep Questionnaire, which includes questions on sleep patterns during the past 4 weeks. Sleep disturbances showed an inverse U-shaped association with sperm concentration, total sperm count, percent motile and percent...

  9. Disturbance observer based hierarchical control of coaxial-rotor UAV.

    Science.gov (United States)

    Mokhtari, M Rida; Cherki, Brahim; Braham, Amal Choukchou

    2017-03-01

    This paper propose an hierarchical controller based on a new disturbance observer with finite time convergence (FTDO) to solve the path tracking of a small coaxial-rotor-typs Unmanned Aerial Vehicles (UAVs) despite of unknown aerodynamic efforts. The hierarchical control technique is used to separate the flight control problem into an inner loop that controls attitude and an outer loop that controls the thrust force acting on the vehicle. The new disturbance observer with finite time convergence is intergated to online estimate the unknown uncertainties and disturbances and to actively compensate them in finite time.The analysis further extends to the design of a control law that takes the disturbance estimation procedure into account. Numerical simulations are carried out to demonstrate the efficiency of the proposed control strategy. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Social Maladjustment and Emotional Disturbance: Problems and Positions I.

    Science.gov (United States)

    Clarizio, Harvey F.

    1992-01-01

    Several controversies surround differentiation between socially maladjusted and seriously emotionally disturbed. Central to controversy is interpretation of social maladjustment as restricted to include socialized aggressive and adjudicated delinquents or broadened to include Conduct Disorders, Oppositional Defiant Disorder, and antisocial…

  11. The ecological disturbance caused by fishing in the North Sea

    NARCIS (Netherlands)

    Greenstreet, S.P.R.; Robinson, L.; Piet, G.J.; Craeymeersch, J.A.M.; Callaway, R.

    2007-01-01

    Current knowledge of the ecological disturbance caused by fishing to marine fish and benthic invertebrate communities is reviewed. This review considers the various components of mortality caused by fishing (eg landings, discards, trawl escapees, etc) and examines the information currently

  12. Reaction Wheel Disturbance Model Extraction Software, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel mechanical noise is one of the largest sources of disturbance forcing on space-based observatories. Such noise arises from mass imbalance, bearing...

  13. PLANTWIDE PERIODICAL DISTURBANCES ISOLATION AND ELIMINATION IN A PETROCHEMICAL UNIT

    Directory of Open Access Journals (Sweden)

    M. Farenzena

    2015-12-01

    Full Text Available Abstract Reducing process variability is crucial to reach a more profitable operating point. Periodical disturbances, however, impose barriers to achieve this goal. Their effect can be strong since one disturbance that appears in a specific loop of a highly coupled plant can be seen in several loops. Thus, isolating their source and diagnosing their cause are essential. In this work, we describe the application of spectral independent component analysis to isolate a periodical disturbance that has a strong impact on the final variability in a polyethylene plant located in Southern Brazil. After the first analysis, the source was detected and the cause identified: valve stiction. To identify the cause (valve, bad tuning, or periodic disturbance, we used the methodology based on higher-order statistics. Once the valve problem had been overcome, the product variance was reduced by 93%.

  14. Stress, coping, and disturbed eating attitudes in teenage girls.

    Science.gov (United States)

    Fryer, S; Waller, G; Kroese, B S

    1997-12-01

    This study explored the relationship between stressors and disturbed eating attitudes among adolescent females, assessing the moderating role of coping and the mediating influence of poor self-esteem. Two hundred eighty-six teenage girls were recruited from local schools, and completed standardized measures of stressors, coping, self-esteem, perfectionism, and disturbed eating attitudes. Regression analyses were used to test for moderating and mediating effects. Stressors and emotion-focused coping were found to be associated with low self-esteem, which in turn was strongly associated with disturbed eating attitudes. Stressors were also directly related to disturbed eating attitudes. The findings provide partial support for existing models of the etiology and maintenance of eating psychopathology, but have wider implications for our understanding of the eating disorders and their treatment.

  15. Minimum disturbance rewards with maximum possible classical correlations

    Energy Technology Data Exchange (ETDEWEB)

    Pande, Varad R., E-mail: varad_pande@yahoo.in [Department of Physics, Indian Institute of Science Education and Research Pune, 411008 (India); Shaji, Anil [School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, 695016 (India)

    2017-07-12

    Weak measurements done on a subsystem of a bipartite system having both classical and nonClassical correlations between its components can potentially reveal information about the other subsystem with minimal disturbance to the overall state. We use weak quantum discord and the fidelity between the initial bipartite state and the state after measurement to construct a cost function that accounts for both the amount of information revealed about the other system as well as the disturbance to the overall state. We investigate the behaviour of the cost function for families of two qubit states and show that there is an optimal choice that can be made for the strength of the weak measurement. - Highlights: • Weak measurements done on one part of a bipartite system with controlled strength. • Weak quantum discord & fidelity used to quantify all correlations and disturbance. • Cost function to probe the tradeoff between extracted correlations and disturbance. • Optimal measurement strength for maximum extraction of classical correlations.

  16. Disturbed Children Under Reduced Auditory Input: A Pilot Study

    Science.gov (United States)

    Fassler, Joan; Bryant, N. Dale

    1971-01-01

    Investigated were attention and performance on simple tasks as well as classroom attention of seriously disturbed, communication impaired, autistic children under conditions of reduced auditory input (using ear protectors). (Author)

  17. Thermal structure and dynamics of Saturn's northern springtime disturbance

    Science.gov (United States)

    Fletcher, L.N.; Hesman, B.E.; Irwin, P.G.J.; Baines, K.H.; Momary, T.W.; Sanchez-Lavega, A.; Flasar, F.M.; Read, P.L.; Orton, G.S.; Simon-Miller, A.; Hueso, R.; Bjoraker, G.L.; Mamoutkine, A.; Del, Rio-Gaztelurrutia; Gomez, J.M.; Buratti, B.; Clark, R.N.; Nicholson, P.D.; Sotin, Christophe

    2011-01-01

    Saturn’s slow seasonal evolution was disrupted in 2010–2011 by the eruption of a bright storm in its northern spring hemisphere. Thermal infrared spectroscopy showed that within a month, the resulting planetary-scale disturbance had generated intense perturbations of atmospheric temperatures, winds, and composition between 20° and 50°N over an entire hemisphere (140,000 kilometers). The tropospheric storm cell produced effects that penetrated hundreds of kilometers into Saturn’s stratosphere (to the 1-millibar region). Stratospheric subsidence at the edges of the disturbance produced “beacons” of infrared emission and longitudinal temperature contrasts of 16 kelvin. The disturbance substantially altered atmospheric circulation, transporting material vertically over great distances, modifying stratospheric zonal jets, exciting wave activity and turbulence, and generating a new cold anticyclonic oval in the center of the disturbance at 41°N.

  18. Sleep Disturbance after Hospitalization and Critical Illness: A Systematic Review.

    Science.gov (United States)

    Altman, Marcus T; Knauert, Melissa P; Pisani, Margaret A

    2017-09-01

    Sleep disturbance during intensive care unit (ICU) admission is common and severe. Sleep disturbance has been observed in survivors of critical illness even after transfer out of the ICU. Not only is sleep important to overall health and well being, but patients after critical illness are also in a physiologically vulnerable state. Understanding how sleep disturbance impacts recovery from critical illness after hospital discharge is therefore clinically meaningful. This Systematic Review aimed to summarize studies that identify the prevalence of and risk factors for sleep disturbance after hospital discharge for critical illness survivors. PubMed (January 4, 2017), MEDLINE (January 4, 2017), and EMBASE (February 1, 2017). Databases were searched for studies of critically ill adult patients after hospital discharge, with sleep disturbance measured as a primary outcome by standardized questionnaire or objective measurement tools. From each relevant study, we extracted prevalence and severity of sleep disturbance at each time point, objective sleep parameters (such as total sleep time, sleep efficiency, and arousal index), and risk factors for sleep disturbance. A total of 22 studies were identified, with assessment tools including subjective questionnaires, polysomnography, and actigraphy. Subjective questionnaire studies reveal a 50-66.7% (within 1 mo), 34-64.3% (>1-3 mo), 22-57% (>3-6 mo), and 10-61% (>6 mo) prevalence of abnormal sleep after hospital discharge after critical illness. Of the studies assessing multiple time points, four of five questionnaire studies and five of five polysomnography studies show improved aspects of sleep over time. Risk factors for poor sleep varied, but prehospital factors (chronic comorbidity, pre-existing sleep abnormality) and in-hospital factors (severity of acute illness, in-hospital sleep disturbance, pain medication use, and ICU acute stress symptoms) may play a role. Sleep disturbance was frequently associated with

  19. Disturbed tryptophan metabolism in cardiovascular disease.

    Science.gov (United States)

    Mangge, H; Stelzer, I; Reininghaus, E Z; Weghuber, D; Postolache, T T; Fuchs, D

    2014-06-01

    cardiovascular morbidity and mortality. Accelerated catabolism of TRP is further involved in the pathogenesis of the anemia of scLGI. The pro-inflammatory cytokine IFN-γ suppresses growth and differentiation of erythroid progenitor cells, and the depletion of TRP limits protein synthesis and thus hemoglobin production, and, through reduction in oxygen supply, may contribute to ischemic vascular disease. In this review we discuss the impact of TRP breakdown and the related complex mechanisms on the prognosis and individual course of CVD. Measurement of TRP, KYN concentrations, and calculation of the KYN/TRYP ratio will contribute to a better understanding of the interplay between inflammation, metabolic syndrome, mood disturbance, and anemia, all previously described as significant predictors of an unfavorable outcome in patients with CVD. The review leads to a novel framework for successful therapeutic modification of several cardinal pathophysiological processes leading to adverse cardiovascular outcome.

  20. Rovers minimize human disturbance in research on wild animals.

    Science.gov (United States)

    Le Maho, Yvon; Whittington, Jason D; Hanuise, Nicolas; Pereira, Louise; Boureau, Matthieu; Brucker, Mathieu; Chatelain, Nicolas; Courtecuisse, Julien; Crenner, Francis; Friess, Benjamin; Grosbellet, Edith; Kernaléguen, Laëtitia; Olivier, Frédérique; Saraux, Claire; Vetter, Nathanaël; Viblanc, Vincent A; Thierry, Bernard; Tremblay, Pascale; Groscolas, René; Le Bohec, Céline

    2014-12-01

    Investigating wild animals while minimizing human disturbance remains an important methodological challenge. When approached by a remote-operated vehicle (rover) which can be equipped to make radio-frequency identifications, wild penguins had significantly lower and shorter stress responses (determined by heart rate and behavior) than when approached by humans. Upon immobilization, the rover-unlike humans-did not disorganize colony structure, and stress rapidly ceased. Thus, rovers can reduce human disturbance of wild animals and the resulting scientific bias.

  1. Sleep disturbances among Swedish soldiers after military service abroad

    OpenAIRE

    Pettersson, Karolina; Saers, Johannes; Lindberg, Eva; Janson, Christer

    2016-01-01

    Aims Since 1956, more than 100,000 Swedish soldiers have served abroad on various international missions. The aim of this paper was to determine whether there was a connection between military service abroad and sleep disorders among Swedish soldiers. Methods The prevalence of sleep disturbances among 1,080 veterans from Kosovo and Afghanistan was compared with almost 27,000 Swedes from a general population sample, using propensity score matching and logistic regression. The sleep disturbance...

  2. Vulnerability of semi-enclosed marine systems to environmental disturbances

    Digital Repository Service at National Institute of Oceanography (India)

    MacCracken, M.; Escobar-Briones, E.; Gilbert, D.; Korotaev, G.; Naqvi, S.W.A.; Perillo, G.M.E.; Rixen, T.; Stanev, E.; Sundby, B.; Thomas, H.; Unger, D.; Urban

    Semi-Enclosed Marine Systems to Environmental Disturbances Michael MacCracken t Elva Escobar-Briones t Denis Gilbert, Gennady Korotaev, Wajih Naqvi, Gerardo M.E. Perillo, Tim Rixen, Emil Stanev, Bj0rn Sundby, Helmuth Thomas t Daniela Unger, and Edward R. Urban, Jr... to land-based disturbances. Locally, SEMSs arc affected by agricultural runoff, urbanization, and pol lution. Changes in freshwater runoffand precipitation, cloudiness, winds, and upwelling can modify sedimentation and erosion patterns...

  3. Prediction of boundary-layer transition caused by crossflow disturbances

    OpenAIRE

    Nomura, Toshiyuki; 野村 聡幸

    1999-01-01

    A prediction system for boundary layer transition is developed which consists of the Navier-Stokes code computing a compressible boundary layer, the linear PSE (Parabolized Stability Equations) code computing the spatial growth of a disturbance, and the N-factor code integrating the growth rate. The system is applied to the case that the transition of the compressible boundary layer on a swept cylinder is caused by cross flow disturbances which have the same spanwise wavelength as observed in...

  4. Optimization of Steady Wall Temperature for Disturbance Control

    OpenAIRE

    Pralits, Jan; Ardeshir, Hanifi

    2003-01-01

    We present a theory for computing the optimal steady wall temperature distribution to suppress the growth of convectively unstable disturbances in compressible boundary layer flows on flat plates. A gradient based iterative procedure is used to minimize an objective function measuring the disturbance kinetic energy. The gradient of interest is obtained from the solution of the adjoint of the boundary layer and parabolized stability equations, which are derived using a Lagrange multiplier tech...

  5. Simulation of Vegetation Recovery from Military Disturbances on Fort Bliss

    Science.gov (United States)

    2005-11-01

    Herbivory 4. Granivory 5. Digging 6. Extreme events 7. Erosion 8. Dust 9. Restoration IV.1. Generic disturbance IV.1.1. General... Herbivory Clipping Insects Rodents kangaroo rats Lagomorphs Simulation of Vegetation Recovery from Military Disturbances on Fort Bliss 51 IV.4...Naturalist, 131: 459–490. 59. McAuliffe, J.R. (1994) Landscape evolution , soil formation, and ecological patterns and processes in Sonoran desert bajadas

  6. A deformation (strain) envelope for cyclic disturbed sand

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2018-01-01

    Recent advances in triaxial testing procedures revealed new properties governing disturbed sand stiffness. This paper summarizes the new observations into an original, proof of concept. The novel concept interpolates effective stress within a strain (deformation) envelope. Coulomb stress limits...... - the fitting is remarkably good even during tests of extreme complexity. The novelty has substantial interdisciplinary potential: offshore anchors and foundations, earthquakes and industrial processes - wherever dynamic loads and disturbed sand are encountered. It opens the door to a new branch of numerical...

  7. Satellite observations of ionosphere disturbance prior to large earthquake

    OpenAIRE

    小山, 孝一郎; 児玉, 哲哉; Oyama, Koichiro; Kodama, Tetsuya

    2017-01-01

    This paper reports ionosphere disturbance which is observed by satellite before large earthquakes. Ionosphere disturbance caused by large earthquakes shows different features, depending on local time, height, epicenter location, and distance from the epicenter. When satellite altitude is high, the effect of large earthquakes does not appear right over the epicenter, but appears over geomagnetic equator and in higher latitude. While the identification of the epicenter location and day of earth...

  8. Respiratory Disturbances in Rett Syndrome: Don't Forget to Evaluate Upper Airway Obstruction

    NARCIS (Netherlands)

    Hagebeuk, Eveline E. O.; Bijlmer, Rob P. G. M.; Koelman, Johannes H. T. M.; Poll-The, Bwee Tien

    2012-01-01

    Rett syndrome is characterized by loss of motor and social functions, development of stereotypic hand movements, seizures, and breathing disturbances. This study evaluates the presence of overnight respiratory disturbances. Polysomnography in combination with a questionnaire (the Sleep Disturbance

  9. Sleep disturbance and neuropsychological function in young children with ADHD.

    Science.gov (United States)

    Schneider, Heather E; Lam, Janet C; Mahone, E Mark

    2016-01-01

    Sleep disturbance, common among children with ADHD, can contribute to cognitive and behavioral dysfunction. It is therefore challenging to determine whether neurobehavioral dysfunction should be attributed to ADHD symptoms, sleep disturbance, or both. The present study examined parent-reported sleep problems (Children's Sleep Habits Questionnaire) and their relationship to neuropsychological function in 64 children, aged 4-7 years, with and without ADHD. Compared to typically developing controls, children with ADHD were reported by parents to have significantly greater sleep disturbance--including sleep onset delay, sleep anxiety, night awakenings, and daytime sleepiness--(all p ≤ .01), and significantly poorer performance on tasks of attention, executive control, processing speed, and working memory (all p sleep disturbance was significantly associated with deficits in attention and executive control skills (all p ≤ .01); however, significant group differences (relative to controls) on these measures remained (p sleep disturbance. While sleep problems are common among young children with ADHD, these findings suggest that inattention and executive dysfunction appear to be attributable to symptoms of ADHD rather than to sleep disturbance. The relationships among sleep, ADHD symptoms, and neurobehavioral function in older children may show different patterns as a function of the chronicity of disordered sleep.

  10. Impact of Alzheimer disease patients' sleep disturbances on their caregivers.

    Science.gov (United States)

    Gehrman, Philip; Gooneratne, Nalaka S; Brewster, Glenna S; Richards, Kathy C; Karlawish, Jason

    Sleep disturbance symptoms are common in persons living with Alzheimer disease (AD). However little is known about the impact of sleep disturbance symptoms in patients living with AD on caregiver burden and quality of life (QOL). The aims of this study were to determine the prevalence of symptoms of disturbed sleep in patients with AD, identify the care-recipient sleep disturbance symptoms that predict caregiver burden and QoL, and determine how care-recipient sleep disturbance symptoms compare to other caregiver and patient characteristics when predicting caregiver QoL. Caregiver burden was assessed using the Screen for Caregiver Burden. Sixty percent of the care-recipients had at least one sleep symptom. In 130 caregiver/patient dyads, nocturnal awakenings, nocturnal wandering, and snoring predicted caregiver burden. Multivariate modeling demonstrated that caregiver burden, caregiver physical and mental health, and caregiver depression were predictors of overall caregiver QoL. Treating disturbed sleep in care-recipients and caregiver mental health symptoms could have important public health impact by improving the lives of the caregiving dyad. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Scaling disturbance instead of richness to better understand anthropogenic impacts on biodiversity.

    Science.gov (United States)

    Mayor, Stephen J; Cahill, James F; He, Fangliang; Boutin, Stan

    2015-01-01

    A primary impediment to understanding how species diversity and anthropogenic disturbance are related is that both diversity and disturbance can depend on the scales at which they are sampled. While the scale dependence of diversity estimation has received substantial attention, the scale dependence of disturbance estimation has been essentially overlooked. Here, we break from conventional examination of the diversity-disturbance relationship by holding the area over which species richness is estimated constant and instead manipulating the area over which human disturbance is measured. In the boreal forest ecoregion of Alberta, Canada, we test the dependence of species richness on disturbance scale, the scale-dependence of the intermediate disturbance hypothesis, and the consistency of these patterns in native versus exotic species and among human disturbance types. We related field observed species richness in 1 ha surveys of 372 boreal vascular plant communities to remotely sensed measures of human disturbance extent at two survey scales: local (1 ha) and landscape (18 km2). Supporting the intermediate disturbance hypothesis, species richness-disturbance relationships were quadratic at both local and landscape scales of disturbance measurement. This suggests the shape of richness-disturbance relationships is independent of the scale at which disturbance is assessed, despite that local diversity is influenced by disturbance at different scales by different mechanisms, such as direct removal of individuals (local) or indirect alteration of propagule supply (landscape). By contrast, predictions of species richness did depend on scale of disturbance measurement: with high local disturbance richness was double that under high landscape disturbance.

  12. Calculated disturbances for evaluation of dynamical properties of freight cars

    Directory of Open Access Journals (Sweden)

    I.A. Mashchenko

    2013-08-01

    Full Text Available Purpose. To form realizations of the calculated disturbances for studying the dynamic properties of railway vehicles. Methodology. Records of the track-test car for one of the typical track sections of the Pridneprovsk railroad are the basic data for building the disturbance components. To derive the true geometric parameters of the railway gauge the records of the track-test car using a double-point metering circuit are transformed considering the transfer function of the measuring system. A model of the calculated disturbances is presented as the four components: a symmetric vertical irregularity determined as a semi-sum of vertical irregularities of the right and left rails; an oblique-symmetric vertical irregularity of the track determined as a semi-difference of vertical irregularities of the right and left rails; horizontal irregularities of the right and left rails. Acceptability criterion of the constructed disturbances is a relationship between the values of the dynamical properties factors of cars and the corresponding experimental data. Findings. The three techniques for the calculated disturbances forming are proposed. The first technique uses records of the track-test car for the track with a sufficiently high amount for given track conditions as components of the calculated disturbances. In so doing symmetrical vertical components of disturbances resulting from records of settling are corrected with the mass and stiffness parameters of the car under consideration. The second technique uses building and applying the theoretical realizations of irregularities corresponding to a real track according to a spectral analysis. The third technique ensures a polyharmonic model of disturbances, the parameters of which are the values of the basic frequencies and amplitudes that are typical for irregularities of a railway track. A possibility of practical applying of the constructed models of disturbances are presented using an example for

  13. [Response of Sediment Micro Environment and Micro Interface to Physical Disturbance Intensity Under the Disturbance of Chironomus plumosus].

    Science.gov (United States)

    Shi, Xiao-dan; Li, Yong; Li, Da-peng; Wang, Ren; Deng, Meng; Huang, Yong

    2015-05-01

    The response of sediment micro environment and micro intertace to physical disturbance intensity under the physical and Chironomus plumosus disturbance was investigated by means of sediment Rhizon samplers and Unisense micro sensor system. The sediment and overlying water were taken from Meiliang bay of Taihu Lake. The results showed that the OPD reached up to 12.1 mm under the high intensity (240 r · min(-1)), while it was higher than 3. 8. mm under low intensity (60 r · min(-1)). The TOE, the difference of TOE and DOE, OPD, ORP and the difference of DO spatial distribution were all positively correlated with the physical disturbance intensity. The increasing magnitude and range of pH as well as the decreasing magnitude and range of ferrous followed the same response tendency. Within the 0-6 cm sediment, the water content and porosity as well as the microbial activity at the same depth increased with the increase of physical disturbance intensity. In addition, the degree of response of the above parameters to the physical disturbance intensity was weakened with the increase of sediment depth. It was suggested that Chironomus plumosus dug more and deeper galleries under high intensity physical disturbance. Therefore, the sediment micro environment and micro interface were transformed in the vertical direction of the sediment.

  14. Basic disturbances of information processing in psychosis prediction.

    Science.gov (United States)

    Bodatsch, Mitja; Klosterkötter, Joachim; Müller, Ralf; Ruhrmann, Stephan

    2013-01-01

    The basic symptoms (BS) approach provides a valid instrument in predicting psychosis onset and represents moreover a significant heuristic framework for research. The term "basic symptoms" denotes subtle changes of cognition and perception in the earliest and prodromal stages of psychosis development. BS are thought to correspond to disturbances of neural information processing. Following the heuristic implications of the BS approach, the present paper aims at exploring disturbances of information processing, revealed by functional magnetic resonance imaging (fMRI) and electro-encephalographic as characteristics of the at-risk state of psychosis. Furthermore, since high-risk studies employing ultra-high-risk criteria revealed non-conversion rates commonly exceeding 50%, thus warranting approaches that increase specificity, the potential contribution of neural information processing disturbances to psychosis prediction is reviewed. In summary, the at-risk state seems to be associated with information processing disturbances. Moreover, fMRI investigations suggested that disturbances of language processing domains might be a characteristic of the prodromal state. Neurophysiological studies revealed that disturbances of sensory processing may assist psychosis prediction in allowing for a quantification of risk in terms of magnitude and time. The latter finding represents a significant advancement since an estimation of the time to event has not yet been achieved by clinical approaches. Some evidence suggests a close relationship between self-experienced BS and neural information processing. With regard to future research, the relationship between neural information processing disturbances and different clinical risk concepts warrants further investigations. Thereby, a possible time sequence in the prodromal phase might be of particular interest.

  15. Road traffic noise: annoyance, sleep disturbance, and public health implications.

    Science.gov (United States)

    Kim, Minho; Chang, Seo I; Seong, Jeong C; Holt, James B; Park, Tae H; Ko, Joon H; Croft, Janet B

    2012-10-01

    The WHO has recognized environmental noise as harmful pollution that causes adverse psychosocial and physiologic effects (i.e., annoyance and sleep disturbance) on human health. In Europe, noise-related health studies have been actively conducted, but the U.S. has lagged behind in this research field. This research predicted ambient levels of road traffic noise for a highly urbanized area: Fulton County GA. Assessment was made of noise impacts on the population, focusing on annoyance and sleep disturbance. All the data sets were collected during 2009-2011, and data analysis was performed in 2010-2011. The study used a sound-propagation model for noise-level prediction and derived noise-impact indicators for annoyance and sleep disturbance from exposure-response models. Then, annoyed and sleep-disturbed populations were predicted with the use of each noise-impact indicator. It was predicted that 109,967 people would be at risk of being highly annoyed, with 19,621 people at risk for high sleep disturbance for Fulton County GA. Noise-impact indicators such as the percentage of those who were highly annoyed and who had high levels of sleep disturbance were expected to be valuable metrics to compare noise equity among urban communities. Many residents of the greater Atlanta area may be exposed to noise levels that put them at risk of being highly annoyed or having high levels of sleep disturbance. These results, if generalized to other urban areas with high levels of road traffic, indicate that it may be important for the public's health to update existing noise-related policies or develop new ones to control and abate noise concerns in urban communities. Published by Elsevier Inc.

  16. Post-disturbance sediment recovery: Implications for watershed resilience

    Science.gov (United States)

    Rathburn, Sara L.; Shahverdian, Scott M.; Ryan, Sandra E.

    2018-03-01

    Sediment recovery following disturbances is a measure of the time required to attain pre-disturbance sediment fluxes. Insight into the controls on recovery processes and pathways builds understanding of geomorphic resilience. We assess post-disturbance sediment recovery in three small (1.5-100 km2), largely unaltered watersheds within the northern Colorado Rocky Mountains affected by wildfires, floods, and debris flows. Disturbance regimes span 102 (floods, debris flows) to 103 years (wildfires). For all case studies, event sediment recovery followed a nonlinear pattern: initial high sediment flux during single precipitation events or high annual snowmelt runoff followed by decreasing sediment fluxes over time. Disturbance interactions were evaluated after a high-severity fire within the South Fork Cache la Poudre basin was followed by an extreme flood one year post-fire. This compound disturbance hastened suspended sediment recovery to pre-fire concentrations 3 years after the fire. Wildfires over the last 1900 YBP in the South Fork basin indicate fire recurrence intervals of 600 years. Debris flows within the upper Colorado River basin over the last two centuries have shifted the baseline of sediment recovery caused by anthropogenic activities that increased debris flow frequency. An extreme flood on North St. Vrain Creek with an impounding reservoir resulted in extreme sedimentation that led to a physical state change. We introduce an index of resilience as sediment recovery/disturbance recurrence interval, providing a relative comparison between sites. Sediment recovery and channel form resilience may be inversely related because of high or low physical complexity in streams. We propose management guidelines to enhance geomorphic resilience by promoting natural processes that maintain physical complexity. Finally, sediment connectivity within watersheds is an additional factor to consider when establishing restoration treatment priorities.

  17. Pediatric Headache and Sleep Disturbance: A Comparison of Diagnostic Groups.

    Science.gov (United States)

    Rabner, Jonathan; Kaczynski, Karen J; Simons, Laura E; LeBel, Alyssa

    2018-02-01

    To examine whether sleep disturbance differs by headache diagnosis in a pediatric sample, and whether this effect remains when other factors affecting sleep are included. Primary headache disorders can be severe and disabling, impacting a child's functioning and quality of life. Many children and adolescents with chronic headaches also experience sleep difficulties, and there is likely a bidirectional relationship between headaches and sleep difficulties. Sleep problems may intensify functional and developmental difficulties in youth with chronic headaches. Despite this, research on sleep has largely been conducted only on those with migraines, with a dearth of studies including samples with tension-type headache (TTH) or new daily persistent-headache (NDPH). This retrospective chart review included 527 patients, ages 7-17 years, with a primary headache diagnosis of migraine (n = 278), TTH (n = 157), and NDPH (n = 92). Patients completed measures of disability, anxiety, and depression and their parents completed measures of sleep disturbance. Sleep disturbance was greater in patients with TTH (10.34 ± 5.94, P = .002) and NDPH (11.52 ± 6.40, P sleep disturbance was significantly associated with higher levels of functional disability (rs ≥ .16), anxiety (rs ≥ .30), and depression (rs ≥ .32). Additionally, higher pain levels were significantly associated with greater sleep disturbance among TTH patients (r = .23), with this association non-significant among the other headache groups. When simultaneously examining demographic, pain-related, and emotional distress factors, older age, higher levels of disability and depression, and NDPH diagnosis were all significant predictors of greater sleep disturbance (r 2  = .25). Assessment and treatment of sleep problems in pediatric patients with chronic headache is important with several contextual and headache diagnostic factors influencing the severity of sleep disturbance

  18. Ionosphere TEC disturbances before strong earthquakes: observations, physics, modeling (Invited)

    Science.gov (United States)

    Namgaladze, A. A.

    2013-12-01

    The phenomenon of the pre-earthquake ionospheric disturbances is discussed. A number of typical TEC (Total Electron Content) relative disturbances is presented for several recent strong earthquakes occurred in different ionospheric conditions. Stable typical TEC deviations from quiet background state are observed few days before the strong seismic events in the vicinity of the earthquake epicenter and treated as ionospheric earthquake precursors. They don't move away from the source in contrast to the disturbances related with geomagnetic activity. Sunlit ionosphere approach leads to reduction of the disturbances up to their full disappearance, and effects regenerate at night. The TEC disturbances often observed in the magnetically conjugated areas as well. At low latitudes they accompany with equatorial anomaly modifications. The hypothesis about the electromagnetic channel of the pre-earthquake ionospheric disturbances' creation is discussed. The lithosphere and ionosphere are coupled by the vertical external electric currents as a result of ionization of the near-Earth air layer and vertical transport of the charged particles through the atmosphere over the fault. The external electric current densities exceeding the regular fair-weather electric currents by several orders are required to produce stable long-living seismogenic electric fields such as observed by onboard measurements of the 'Intercosmos-Bulgaria 1300' satellite over the seismic active zones. The numerical calculation results using the Upper Atmosphere Model demonstrate the ability of the external electric currents with the densities of 10-8-10-9 A/m2 to produce such electric fields. The sumulations reproduce the basic features of typical pre-earthquake TEC relative disturbances. It is shown that the plasma ExB drift under the action of the seismogenic electric field leads to the changes of the F2 region electron number density and TEC. The upward drift velocity component enhances NmF2 and TEC and

  19. Sleep disturbances in tension-type headache and migraine

    Science.gov (United States)

    Fernández-de-las-Peñas, César; Fernández-Muñoz, Juan J.; Palacios-Ceña, María; Parás-Bravo, Paula; Cigarán-Méndez, Margarita; Navarro-Pardo, Esperanza

    2017-01-01

    Current research into the pathogenesis of tension-type headache (TTH) and migraine is focused on altered nociceptive pain processing. Among the potential factors that influence sensitization mechanisms, emotional stress, depression, or sleep disorders all have an essential role: they increase the excitability of nociceptive firing and trigger hyperalgesic responses. Sleep disturbances and headache disorders share common brain structures and pathogenic mechanisms and TTH, migraine, and sleep disturbances often occur together; for example, 50% of individuals who have either TTH or migraine have insomnia. Moreover, insomnia and poor sleep quality have been associated with a higher frequency and intensity of headache attacks, supporting the notion that severity and prevalence of sleep problems correlate with headache burden. It should be noted that the association between headaches and sleep problems is bidirectional: headache can promote sleep disturbances, and sleep disturbances can also precede or trigger a headache attack. Therefore, a better understanding of the factors that affect sleep quality in TTH and migraine can assist clinicians in determining better and adequate therapeutic programs. In this review, the role of sleep disturbances in headaches, and the association with depression, emotional stress, and pain sensitivity in individuals with TTH or migraine are discussed. PMID:29399051

  20. Simulation of landscape disturbances and the effect of climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W.L.

    1993-01-29

    The purpose of this research is to understand how changes in climate may affect the structure of landscapes that are subject to periodic disturbances. A general model useful for examining the linkage between climatic change and landscape change has been developed. The model makes use of synoptic climatic data, a geographical information system (GRASS), field data on the location of disturbance patches, simulation code written in the SIMSCRIPT language, and a set of landscape structure analysis programs written specifically for this research project. A simplified version of the model, lacking the climatic driver, has been used to analyze how changes in disturbance regimes (in this case settlement and fire suppression) affect landscape change. Landscape change lagged in its response to changes in the disturbance regime, but the lags differed depending upon the character of the change and the particular measure considered. The model will now be modified for use in a specific setting to analyze the effects of changes in climate on the structure of flood-disturbed patches along the Animas River, Colorado.

  1. A method to identify aperiodic disturbances in the ionosphere

    Directory of Open Access Journals (Sweden)

    J.-S. Wang

    2014-05-01

    Full Text Available In this paper, variations in the ionospheric F2 layer's critical frequency are decomposed into their periodic and aperiodic components. The latter include disturbances caused both by geophysical impacts on the ionosphere and random noise. The spectral whitening method (SWM, a signal-processing technique used in statistical estimation and/or detection, was used to identify aperiodic components in the ionosphere. The whitening algorithm adopted herein is used to divide the Fourier transform of the observed data series by a real envelope function. As a result, periodic components are suppressed and aperiodic components emerge as the dominant contributors. Application to a synthetic data set based on significant simulated periodic features of ionospheric observations containing artificial (and, hence, controllable disturbances was used to validate the SWM for identification of aperiodic components. Although the random noise was somewhat enhanced by post-processing, the artificial disturbances could still be clearly identified. The SWM was then applied to real ionospheric observations. It was found to be more sensitive than the often-used monthly median method to identify geomagnetic effects. In addition, disturbances detected by the SWM were characterized by a Gaussian-type probability density function over all timescales, which further simplifies statistical analysis and suggests that the disturbances thus identified can be compared regardless of timescale.

  2. Predictive Feedback and Feedforward Control for Systems with Unknown Disturbances

    Science.gov (United States)

    Juang, Jer-Nan; Eure, Kenneth W.

    1998-01-01

    Predictive feedback control has been successfully used in the regulation of plate vibrations when no reference signal is available for feedforward control. However, if a reference signal is available it may be used to enhance regulation by incorporating a feedforward path in the feedback controller. Such a controller is known as a hybrid controller. This paper presents the theory and implementation of the hybrid controller for general linear systems, in particular for structural vibration induced by acoustic noise. The generalized predictive control is extended to include a feedforward path in the multi-input multi-output case and implemented on a single-input single-output test plant to achieve plate vibration regulation. There are cases in acoustic-induce vibration where the disturbance signal is not available to be used by the hybrid controller, but a disturbance model is available. In this case the disturbance model may be used in the feedback controller to enhance performance. In practice, however, neither the disturbance signal nor the disturbance model is available. This paper presents the theory of identifying and incorporating the noise model into the feedback controller. Implementations are performed on a test plant and regulation improvements over the case where no noise model is used are demonstrated.

  3. Simulation of landscape disturbances and the effect of climatic change

    International Nuclear Information System (INIS)

    Baker, W.L.

    1993-01-01

    The purpose of this research is to understand how changes in climate may affect the structure of landscapes that are subject to periodic disturbances. A general model useful for examining the linkage between climatic change and landscape change has been developed. The model makes use of synoptic climatic data, a geographical information system (GRASS), field data on the location of disturbance patches, simulation code written in the SIMSCRIPT language, and a set of landscape structure analysis programs written specifically for this research project. A simplified version of the model, lacking the climatic driver, has been used to analyze how changes in disturbance regimes (in this case settlement and fire suppression) affect landscape change. Landscape change lagged in its response to changes in the disturbance regime, but the lags differed depending upon the character of the change and the particular measure considered. The model will now be modified for use in a specific setting to analyze the effects of changes in climate on the structure of flood-disturbed patches along the Animas River, Colorado

  4. Medium term ecohydrological response of peatland bryophytes to canopy disturbance

    Science.gov (United States)

    Leonard, Rhoswen; Kettridge, Nick; Krause, Stefan; Devito, Kevin; Granath, Gustaf; Petrone, Richard; Mandoza, Carl; Waddington, James Micheal

    2016-04-01

    Canopy disturbance in northern forested peatlands is widespread. Canopy changes impact the ecohydrological function of moss and peat, which provide the principal carbon store within these carbon rich ecosystems. Different mosses have contrasting contributions to carbon and water fluxes (e.g. Sphagnum fuscum and Pleurozium schreberi) and are strongly influenced by canopy cover. As a result, changes in canopy cover lead to long-term shifts in species composition and associated ecohydrological function. Despite this, the medium-term response to such disturbance, the associated lag in this transition to a new ecohydrological and biogeochemical regime, is not understood. Here we investigate this medium term ecohydrological response to canopy removal using a randomised plot design within a north Albertan peatland. We show no significant ecohydrological change in treatment plots four years after canopy removal. Notably, Pleurozium schreberi and Sphagnum fuscum remained within respective plots post treatment and there was no significant difference in plot resistance to evapotranspiration or carbon exchange. Our results show that canopy removal alone has little impact on bryophyte ecohydrology in the short/medium term. This resistance to disturbance contrasts strongly with dramatic short-term changes observed within mineral soils suggesting that concurrent shifts in the large scale hydrology induced within such disturbances are necessary to cause rapid ecohydrological transitions. Understanding this lagged response is critical to determine the decadal response of carbon and water fluxes in response to disturbance and the rate at which important medium term ecohydrological feedbacks are invoked.

  5. Dynamic positioning system based on active disturbance rejection technology

    Science.gov (United States)

    Lei, Zhengling; Guo, Chen; Fan, Yunsheng

    2015-08-01

    A dynamically positioned vessel, by the International Maritime Organization (IMO) and the certifying class societies (DNV, ABS, LR, etc.), is defined as a vessel that maintains its position and heading (fixed location or pre-determined track) exclusively by means of active thrusters. The development of control technology promotes the upgrading of dynamic positioning (DP) systems. Today there are two different DP systems solutions available on the market: DP system based on PID regulator and that based on model-based control. Both systems have limited disturbance rejection capability due to their design principle. In this paper, a new DP system solution is proposed based on Active Disturbance Rejection Control (ADRC) technology. This technology is composed of Tracking-Differentiator (TD), Extended State Observer (ESO) and Nonlinear Feedback Combination. On one hand, both TD and ESO can act as filters and can be used in place of conventional filters; on the other hand, the total disturbance of the system can be estimated and compensated by ESO, which therefore enhances the system's disturbance rejection capability. This technology's advantages over other methods lie in two aspects: 1) This method itself can not only achieve control objectives but also filter noisy measurements without other specialized filters; 2) This method offers a new useful approach to suppress the ocean disturbance. The simulation results demonstrate the effectiveness of the proposed method.

  6. Addressing sleep disturbances: An opportunity to prevent cardiometabolic disease?

    Science.gov (United States)

    GRANDNER, MICHAEL A.

    2014-01-01

    There is increasing awareness of the role of sleep disturbance as an important factor in health and disease. Although subclinical sleep disturbances (insufficient sleep duration or inadequate sleep quality) may be difficult to assess with conceptual and/or methodological clarity, this review attempts to summarize and synthesize these findings. First, the concept of sleep disturbance in a public health context is introduced, to provide context and rationale. Second, operational definitions of ‘cardiometabolic disease’ and ‘sleep disturbance’ are offered, to address many unclear operationalizations. Third, the extant literature is summarized regarding short or long sleep duration and/or insufficient sleep, insomnia and insomnia symptoms, general (non-specific sleep disturbances), circadian rhythm abnormalities that result in sleep disturbances, and, briefly, sleep-disordered breathing. Fourth, the review highlights the social/behavioural context of sleep, including discussions of sleep and race/ethnicity, socio-economic position, and other social/environmental factors, in order to place these findings in a social-environmental context relevant to public health. Fifth, the review highlights the issue of sleep as a domain of health behaviour and addresses issues regarding development of healthy sleep interventions. Finally, a research agenda of future directions is proposed. PMID:24892892

  7. Reclamation of lands disturbed by mining activities in Bulgaria

    Directory of Open Access Journals (Sweden)

    I. Kirilov

    2016-12-01

    Full Text Available Abstract. Disturbed by the mining industry area in Bulgaria is about 24.113 ha of which only 8.253 ha are reclaimed. Reclamation of disturbed areas covers a complex of engineering, technical, ameliorative, agricultural, forestry and other activities, which aim at restoration of the disturbed terrains and their re-entry into economic turnover in accordance with environmental conditions and area landscape. All disturbed lands as well as their adjacent areas that have completely or partially lost productivity as a result of the negative impact of mining activities and land damage are subject to reclamation. Land reclamation is a two-step process which includes: technical reclamation and biological reclamation. Technical reclamation is performed by the land owner and covers cleaning and preparation of the terrain, leveling, final formation and laying a humus soil layer on site by adding appropriate “improvers” (e.g. fertilizers, texture enhancers, etc.. Biological reclamation covers restoration of the productivity of the disturbed areas. Reclamation technologies applied in Bulgaria as a whole have led to a state of these territories that requires both maintenance and search for new ways of integration of the reclaimed landscapes with modern economic activities. The aim of the study is analysis and applying reliable modern practices that ensure good results in visual qualities of landscape and more options for future use of the reclaimed land.

  8. Increased sensitivity to climate change in disturbed ecosystems.

    Science.gov (United States)

    Kröel-Dulay, György; Ransijn, Johannes; Schmidt, Inger Kappel; Beier, Claus; De Angelis, Paolo; de Dato, Giovanbattista; Dukes, Jeffrey S; Emmett, Bridget; Estiarte, Marc; Garadnai, János; Kongstad, Jane; Kovács-Láng, Edit; Larsen, Klaus Steenberg; Liberati, Dario; Ogaya, Romà; Riis-Nielsen, Torben; Smith, Andrew R; Sowerby, Alwyn; Tietema, Albert; Penuelas, Josep

    2015-03-24

    Human domination of the biosphere includes changes to disturbance regimes, which push many ecosystems towards early-successional states. Ecological theory predicts that early-successional ecosystems are more sensitive to perturbations than mature systems, but little evidence supports this relationship for the perturbation of climate change. Here we show that vegetation (abundance, species richness and species composition) across seven European shrublands is quite resistant to moderate experimental warming and drought, and responsiveness is associated with the dynamic state of the ecosystem, with recently disturbed sites responding to treatments. Furthermore, most of these responses are not rapid (2-5 years) but emerge over a longer term (7-14 years). These results suggest that successional state influences the sensitivity of ecosystems to climate change, and that ecosystems recovering from disturbances may be sensitive to even modest climatic changes. A research bias towards undisturbed ecosystems might thus lead to an underestimation of the impacts of climate change.

  9. Management of functional disturbances of the stomatognathic system

    International Nuclear Information System (INIS)

    Piehslinger, E.

    2001-01-01

    In the management of functional disturbances of the stomatognathic system symptomatic and causal therapeutic methods can be distinguished. Symptomatic therapy encompasses medication, physical methods (heat, cold, radiation, TENS) in combination with physiotherapy and emergency splint. After one or two weeks of symptomatic therapy the patient should be free of pain allowing precise diagnostic procedures followed by causal therapy managing muscular problems, joint pathology and occlusal disturbances. Splint therapy is used to establish a therapeutic joint position according to articulator mounting. After splint therapy prosthodontic and/or orthodontic treatment is needed to restore occlusion. Interdisciplinary management in the therapy of functional disturbances of the stomatognathic system is of utmost importance due to the relationship between chewing muscles, neck muscles and body posture. In addition to splint therapy, physiotherapy, logopedic therapy, myofunctional therapy, psychologic and psychiatric intervention is performed. (orig.) [de

  10. Sleep disturbances in Parkinson's disease patients and management options

    Directory of Open Access Journals (Sweden)

    Claassen DO

    2011-12-01

    Full Text Available Daniel O Claassen, Scott J KutscherDepartment of Neurology, Vanderbilt University, Nashville, TN, USAAbstract: Sleep disturbances are among the most common nonmotor complaints of patients with Parkinson's disease (PD, and can have a great impact on quality of life. These disturbances manifest in a variety of ways; for instance, insomnia, sleep fragmentation, and excessive daytime sleepiness. Sleep-related movement disorders such as restless legs syndrome and periodic leg movements may share a common pathophysiology, and occurrence of rapid eye movement behavior disorder may predate the onset of PD or other synucleinopathies by several years. Medications for PD can have a significant impact on sleep, representing a great challenge to the treating physician. Awareness of the complex relationship between PD and sleep disorders, as well as the varied way in which sleep disturbances appear, is imperative for successful long-term management.Keywords: sleep disorders, insomnia, restless legs syndrome, Parkinson disease, fatigue, REM behavior disorder

  11. Stress and sleep disturbances in female college students.

    Science.gov (United States)

    Lee, Shih-Yu; Wuertz, Caroline; Rogers, Rebecca; Chen, Yu-Ping

    2013-11-01

    To describe the sleep characteristics and examine the associations among perceived stress, sleep disturbances, depressive symptoms, and physical symptoms among female college students. A total of 103 students completed a battery of questionnaires. The students experienced high stress during the school year. The majority of them slept less than 6 hours during weekdays and experienced moderate fatigue. High stress levels are associated with sleep disturbances, less nocturnal total sleep time, higher fatigue severity, and more depressive symptoms. Perceived stress and sleep disturbances are significant predictors for depressive symptoms and physical symptoms. Compared to the good sleepers, the poor sleepers reported more daytime sleepiness, depressive symptoms, and physical symptoms. Interventions to reduce stress and improve sleep are critically needed in college education.

  12. Self-reported sleep disturbance and survival in myelodysplastic syndromes.

    Science.gov (United States)

    Luskin, Marlise R; Cronin, Angel M; Owens, Robert L; DeAngelo, Daniel J; Stone, Richard M; Wadleigh, Martha; Steensma, David P; Abel, Gregory A

    2017-05-01

    Neither the prevalence of sleep disturbance nor its association with fatigue and overall survival (OS) are well understood for patients with myelodysplastic syndromes (MDS). New patients at our institution (n = 251; 2006-2014) completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, which includes questions about sleep and fatigue. Fifty-three per cent reported at least 'a little' trouble sleeping. In multivariable models, anaemia and sleep disturbance were associated with fatigue (both P < 0·001). Additionally, in separate models, sleep disturbance (P = 0·002) and fatigue (P = 0·04) both predicted OS. Our data suggest that improving sleep quality may impact MDS-related fatigue and OS. © 2017 John Wiley & Sons Ltd.

  13. GMD Coupling to Power Systems and Disturbance Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, Michael Kelly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bent, Russell Whitford [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-24

    Presentation includes slides on Geomagnetic Disturbance: Ground Fields; Geomagnetic Disturbance: Coupling to Bulk Electric System; Geomagnetic Disturbance: Transformers; GMD Assessment Workflow (TPL-007-1); FERC order 830; Goals; SuperMag (1 min data) Nov. 20-21, 2003 Storm (DST = -422); Spherical Harmonics; Spherical Harmonics Nov. 20-21, 2003 Storm (DST = -422); DST vs HN0,0; Fluctuations vs. DST; Fluctuations; Conclusions and Next Steps; GMD Assessment Workflow (TPL-007-1); EMP E3 Coupling to Texas 2000 Bus Model; E3 Coupling Comparison (total GIC) Varying Ground Zero; E3 Coupling Comparison (total MVAR) Varying Ground Zero; E3 Coupling Comparison (GIC) at Peak Ground Zero; E3 Coupling Comparison (GIC) at Peak Ground Zero; and Conclusion.

  14. Global and local disturbances interact to modify seagrass palatability

    Science.gov (United States)

    Egea, Luis G.; Ortega, María J.; Hernández, Ignacio; Vergara, Juan J.; Brun, Fernando G.

    2017-01-01

    Global change, such as warming and ocean acidification, and local anthropogenic disturbances, such as eutrophication, can have profound impacts on marine organisms. However, we are far from being able to predict the outcome of multiple interacting disturbances on seagrass communities. Herbivores are key in determining plant community structure and the transfer of energy up the food web. Global and local disturbances may alter the ecological role of herbivory by modifying leaf palatability (i.e. leaf traits) and consequently, the feeding patterns of herbivores. This study evaluates the main and interactive effects of factors related to global change (i.e. elevated temperature, lower pH levels and associated ocean acidification) and local disturbance (i.e. eutrophication through ammonium enrichment) on a broad spectrum of leaf traits using the temperate seagrass Cymodocea nodosa, including structural, nutritional, biomechanical and chemical traits. The effect of these traits on the consumption rates of the generalist herbivore Paracentrotus lividus (purple sea urchin) is evaluated. The three disturbances of warming, low pH level and eutrophication, alone and in combination, increased the consumption rate of seagrass by modifying all leaf traits. Leaf nutritional quality, measured as nitrogen content, was positively correlated to consumption rate. In contrast, a negative correlation was found between feeding decisions by sea urchins and structural, biomechanical and chemical leaf traits. In addition, a notable accomplishment of this work is the identification of phenolic compounds not previously reported for C. nodosa. Our results suggest that global and local disturbances may trigger a major shift in the herbivory of seagrass communities, with important implications for the resilience of seagrass ecosystems. PMID:28813506

  15. Landscape-scale forest disturbance regimes in southern Peruvian Amazonia.

    Science.gov (United States)

    Boyd, Doreen S; Hill, Ross A; Hopkinson, Chris; Baker, Timothy R

    2013-10-01

    Landscape-scale gap-size frequency distributions in tropical forests are a poorly studied but key ecological variable. Currently, a scale gap currently exists between local-scale field-based studies and those employing regional-scale medium-resolution satellite data. Data at landscape scales but of fine resolution would, however, facilitate investigation into a range of ecological questions relating to gap dynamics. These include whether canopy disturbances captured in permanent sample plots (PSPs) are representative of those in their surrounding landscape, and whether disturbance regimes vary with forest type. Here, therefore, we employ airborne LiDAR data captured over 142.5 km2 of mature, swamp, and regenerating forests in southeast Peru to assess the landscape-scale disturbance at a sampling resolution of up to 2 m. We find that this landscape is characterized by large numbers of small gaps; large disturbance events are insignificant and infrequent. Of the total number of gaps that are 2 m2 or larger in area, just 0.45% were larger than 100 m2, with a power-law exponent (alpha) value of the gap-size frequency distribution of 2.22. However, differences in disturbance regimes are seen among different forest types, with a significant difference in the alpha value of the gap-size frequency distribution observed for the swamp/regenerating forests compared with the mature forests at higher elevations. Although a relatively small area of the total forest of this region was investigated here, this study presents an unprecedented assessment of this landscape with respect to its gap dynamics. This is particularly pertinent given the range of forest types present in the landscape and the differences observed. The coupling of detailed insights into forest properties and growth provided by PSPs with the broader statistics of disturbance events using remote sensing is recommended as a strong basis for scaling-up estimates of landscape and regional-scale carbon balance.

  16. Pervasive growth reduction in Norway spruce forests following wind disturbance.

    Directory of Open Access Journals (Sweden)

    Rupert Seidl

    Full Text Available BACKGROUND: In recent decades the frequency and severity of natural disturbances by e.g., strong winds and insect outbreaks has increased considerably in many forest ecosystems around the world. Future climate change is expected to further intensify disturbance regimes, which makes addressing disturbances in ecosystem management a top priority. As a prerequisite a broader understanding of disturbance impacts and ecosystem responses is needed. With regard to the effects of strong winds--the most detrimental disturbance agent in Europe--monitoring and management has focused on structural damage, i.e., tree mortality from uprooting and stem breakage. Effects on the functioning of trees surviving the storm (e.g., their productivity and allocation have been rarely accounted for to date. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that growth reduction was significant and pervasive in a 6.79 million hectare forest landscape in southern Sweden following the storm Gudrun (January 2005. Wind-related growth reduction in Norway spruce (Picea abies (L. Karst. forests surviving the storm exceeded 10% in the worst hit regions, and was closely related to maximum gust wind speed (R(2 = 0.849 and structural wind damage (R(2 = 0.782. At the landscape scale, wind-related growth reduction amounted to 3.0 million m(3 in the three years following Gudrun. It thus exceeds secondary damage from bark beetles after Gudrun as well as the long-term average storm damage from uprooting and stem breakage in Sweden. CONCLUSIONS/SIGNIFICANCE: We conclude that the impact of strong winds on forest ecosystems is not limited to the immediately visible area of structural damage, and call for a broader consideration of disturbance effects on ecosystem structure and functioning in the context of forest management and climate change mitigation.

  17. Disturbances of sleep continuity in women during the menopausal transition.

    Science.gov (United States)

    Słopień, Radosław; Wichniak, Adam; Pawlak, Michał; Słopień, Agnieszka; Warenik-Szymankiewicz, Alina; Sajdak, Stefan

    2015-01-01

    The objective of the study was to evaluate the prevalence of sleep continuity disorders in women during menopausal transition, to evaluate the relationship between disturbances of sleep continuity and the severity of menopausal syndrome and the occurrence of various symptoms of this syndrome, as well as to evaluate the association between the presence of sleep disturbances and serum concentrations of gonadotropins, prolactin and sex hormones. Consecutive 140 women (mean age 54.4 ± 4.7 years) searching for the treatment in the Clinic for Gynaecological Endocrinology who reported symptoms of menopausal syndrome were investigated. The type and severity of disturbances of sleep continuity were evaluated using a survey based on the sleep related questions from Hamilton Depression Rating Scale. The severity of symptoms of menopausal syndrome was assessed using the Kupperman Index. The concentration of the following hormones in blood serum was tested: FSH, LH, 17β-estradiol, PRL, total testosterone, DHEAS and SHBG. Disturbances of sleep continuity were a prevalent complaint in the studied group of women. Difficulties in falling asleep were found in 57.8% of women, difficulties in maintaining sleep in 70%, waking up too early in 60.7%. The severity of all three types of sleep continuity disturbances was related to the severity of menopausal syndrome as measured with Kupperman Index (Spearman correlation coefficient r = 0.63, r = 0.61, r = 0.52, respectively; p sleep were negatively correlated with the concentration of FSH (r = - 0.19; p Sleep continuity disturbances are frequently reported by women during the menopausal transition. Interventions aimed at reducing the symptoms of menopausal syndrome should be considered as important action to improve sleep quality in this population of patients.

  18. Microbial Mat Compositional and Functional Sensitivity to Environmental Disturbance

    Directory of Open Access Journals (Sweden)

    Eva Christine Preisner

    2016-10-01

    Full Text Available The ability of ecosystems to adapt to environmental perturbations depends on the duration and intensity of change and the overall biological diversity of the system. While studies have indicated that rare microbial taxa may provide a biological reservoir that supports long-term ecosystem stability, how this dynamic population is influenced by environmental parameters remains unclear. In this study, a microbial mat ecosystem located on San Salvador Island, The Bahamas was used as a model to examine how environmental disturbance affects the protein synthesis potential (PSP of rare and abundant archaeal and bacterial communities and how these changes impact potential biogeochemical processes. This ecosystem experienced a large shift in salinity (230 to 65 g kg-1 during 2011-2012 following the landfall of Hurricane Irene on San Salvador Island. High throughput sequencing and analysis of 16S rRNA and rRNA genes from samples before and after the pulse disturbance showed significant changes in the diversity and PSP of abundant and rare taxa, suggesting overall compositional and functional sensitivity to environmental change. In both archaeal and bacterial communities, while the majority of taxa showed low PSP across conditions, the overall community PSP increased post-disturbance, with significant shifts occurring among abundant and rare taxa across and within phyla. Broadly, following the post-disturbance reduction in salinity, taxa within Halobacteria decreased while those within Crenarchaeota, Thaumarchaeota, Thermoplasmata, Cyanobacteria, and Proteobacteria, increased in abundance and PSP. Quantitative PCR of genes and transcripts involved in nitrogen and sulfur cycling showed concomitant shifts in biogeochemical cycling potential. Post-disturbance conditions increased the expression of genes involved in N-fixation, nitrification, denitrification, and sulfate reduction. Together, our findings show complex community adaptation to environmental

  19. Disturbed eating behaviours and associated psychographic characteristics of college students.

    Science.gov (United States)

    Quick, V M; Byrd-Bredbenner, C

    2013-07-01

    Young adulthood is a stressful transition period that may increase the risk for disturbed eating, especially for college students. The present study aimed to explore disturbed eating behaviours and a broad array of associated psychographic characteristics in a large, diverse sample of college students. College students (n = 2604; 58% white; 63% female) enrolled at three large, public US universities in 2009 and 2010 were recruited to take an online survey. The survey included reliable and valid disturbed eating behaviour and associated psychographic characteristic measures. Many participants engaged in disturbed eating practices. For example, one-quarter of women and one-fifth of men engaged in dietary restraint. One in seven reported regularly binge eating. One-third used inappropriate compensatory behaviours (self-induced vomiting, medicine misuse and excessive exercise) as a means for controlling weight and/or shape, with the rate of these behaviours reaching clinically significant levels for 4%, 3% and 5% of participants, respectively. Examination of psychographic characteristics revealed that one-fifth had moderate levels of depression and anxiety severity and almost half engaged in at least one obsessive-compulsive disorder type behaviour. Females felt under more pressure to attain the media physical appearance standard than males. The findings of the present study suggest that nutrition education interventions for college students may be needed to address disturbed eating behaviours and to provide guidance on how to seek professional help. The findings also suggest that it may be prudent for healthcare professionals to routinely screen college students for disturbed eating behaviours and offer interventions early when treatment is likely to be most effective. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  20. Stress-related sleep disturbance and polysomnographic response to caffeine

    Science.gov (United States)

    Drake, Christopher L.; Jefferson, Catherine; Roehrs, Timothy; Roth, Thomas

    2008-01-01

    Background and purpose To determine the sleep response to caffeine in individuals vulnerable to stress-related sleep disturbance as measured by polysomnography. Patients and methods Eleven healthy individuals without insomnia scoring low (4 women, mean age=32.64 ± 15.46 years) and 10 healthy individuals also without insomnia scoring high (6 women, mean age=34.20 ± 13.73 years) on a measure of vulnerability to stress-related sleep disturbance were studied in a laboratory protocol. A moderate-low dose of caffeine (3 mg/kg) was administered 1 h prior to lights-out and compared to a counterbalanced control night with each condition separated by 1 week. Standard polysomnographic measures were assessed (i.e. total sleep time, sleep efficiency, latency to persistent sleep, and sleep stage percentages) for both control and caffeine nights. Results There were no between-group differences in sleep on the control night. Importantly, individuals reporting vulnerability to stress-related sleep disturbance had significantly prolonged latency to persistent sleep in response to the caffeine challenge (interaction; P sleep disturbance exhibited greater objectively verifiable sleep-reactivity in response to a caffeine challenge compared to non-vulnerable individuals. These results suggest that the construct of individual differences in vulnerability to sleep disturbance applies to a pharmacological ‘stressor’ (i.e. caffeine) as well as to previously assessed stressors such as a first-night effect. This finding provides further support for generalized trait vulnerability by demonstrating a sleep disturbance to a wake-promoting pharmacological challenge in specific a priori identified individuals. PMID:16996309

  1. The influence of experimental wind disturbance on forest fuels and fire characteristics

    Science.gov (United States)

    Jeffery B. Cannon; Joseph J. O' Brien; Louise Loudermilk; Matthew Dickinson; Chris J. Peterson

    2014-01-01

    Current theory in disturbance ecology predicts that extreme disturbances in rapid succession can lead to dramatic changes in species composition or ecosystem processes due to interactions among disturbances. However, the extent to which less catastrophic, yet chronic, disturbances such as wind damage and fire interact is not well studied. In this study, we simulated...

  2. Ensemble modeling to predict habitat suitability for a large-scale disturbance specialist

    Science.gov (United States)

    Quresh S. Latif; Victoria A. Saab; Jonathan G. Dudley; Jeff P. Hollenbeck

    2013-01-01

    To conserve habitat for disturbance specialist species, ecologists must identify where individuals will likely settle in newly disturbed areas. Habitat suitability models can predict which sites at new disturbances will most likely attract specialists. Without validation data from newly disturbed areas, however, the best approach for maximizing predictive accuracy can...

  3. Disturbance and canopy gaps as indicators of forest health in the Blue Mountains of Oregon.

    Science.gov (United States)

    Jerome S. Beatty; Brian W. Geils; John E. Lundquist

    1995-01-01

    Disturbance profiles, indices based on both spatial and non-spatial statistics, are used to examine how small-scale disturbances and the resulting canopy gaps disrupt ecosystem patterns and processes in selected stands in the Blue Mountains of Oregon. The biological meaning of many indices remains undefined for small scale disturbance phenomena, but their disturbance...

  4. Soil strength response of select soil disturbance classes on a wet pine flat in South Carolina

    Science.gov (United States)

    Emily A. Carter; W. Michael Aust; James A. Burger

    2007-01-01

    Harvest operations conducted under conditions of high soil moisture on a et pine flat in South Carolina resulted in a high degree of soil surface disturbance. Less soil surface disturbance occurred when soil moisture content was lower. Soil strength varied by soil disturbance class in wet harvested locations and highly disturbed areas were associated with low soil...

  5. Restoration of heterogeneous disturbance regimes for the preservation of endangered species

    Science.gov (United States)

    Steven D. Warren; Reiner Buttner

    2014-01-01

    Disturbance is a natural component of ecosystems. All species, including threatened and endangered species, evolved in the presence of, and are adapted to natural disturbance regimes that vary in the kind, frequency, severity, and duration of disturbance. We investigated the relationship between the level of visible soil disturbance and the density of four endangered...

  6. Model tracking controller design of robot manipulator system with disturbances

    Directory of Open Access Journals (Sweden)

    Dazhong Wang

    2015-06-01

    Full Text Available In the model tracking control of robot manipulator system, the treatment of nonlinear uncertainty in the system has always been an active research field. This article establishes a kinetic equation for robot manipulator system based on Lagrange equation and proposes a model tracking control system based on differential divisor. On this basis, this article proposes a model tracking control scheme for robot manipulator systems with disturbances. The proposed scheme is robust stable under the external disturbances. At last, the system simulation approach is employed to verify the effectiveness of this scheme on robot manipulator control.

  7. Nonlinear Feedforward Control for Wind Disturbance Rejection on Autonomous Helicopter

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; A. Danapalasingam, Kumeresan

    2010-01-01

    This paper presents the design and verification of a model based nonlinear feedforward controller for wind disturbance rejection on autonomous helicopters. The feedforward control is based on a helicopter model that is derived using a number of carefully chosen simplifications to make it suitable...... for the purpose. The model is inverted for the calculation of rotor collective and cyclic pitch angles given the wind disturbance. The control strategy is then applied on a small helicopter in a controlled wind environment and flight tests demonstrates the effectiveness and advantage of the feedforward controller....

  8. Characterising power quality disturbances resulting from current limiting fuse operation

    Directory of Open Access Journals (Sweden)

    N. Ortiz S.

    2011-06-01

    Full Text Available This article presents novel and easily implemented tools for characterising electrical disturbances originated by fuse operations. A methodology is described that (with the use of some descriptors led to identifying electrical disturbances of this kind. The algorithm’s decision thresholds were estimated using machine learning techniques. This work was aimed at providing new tools for assessing power quality, characterising and extracting information from voltage and current records obtained from monitoring distribution systems. MATLAB was used for validating this methodology, receiving voltage and current records of simulated events in ATP-EMTP and also real events as input.

  9. Active rejection of persistent disturbances in flexible space structures

    Science.gov (United States)

    Hwang, Cheng-Neng; Jayasuriya, Suhada; Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    A dynamic compensator for active rejection of persistent disturbances in flexible space structures is designed on the principle of the H(infinity)-optimization of the sensitivity transfer function matrix. A general state space solution is formulated to the multiinput multioutput H(infinity)-optimal control problem, allowing the use of the H(infinity)-optimal synthesis algorithm for the state-space models of space structures that result from model order reduction. Disturbances encountered in flexible space structures, such as shuttle docking, are investigated using the high-mode and the reduced-order models of a cantilevered two-bay truss, demonstrating the applicability of the H(infinity)-optimal approach.

  10. Revegetation studies on oil shale related disturbances in Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Redente, E.F.; Cook, C.W.

    1982-06-01

    An interdisciplinary research project was initiated in 1976 to provide both basic and applied information that would aid in the reestablishment of natural functioning ecosystems on land disturbances associated with energy development. The approach included field, laboratory, and greenhouse experiments designed to provide both structural and functional information about disturbed ecological systems in the semiarid west. This report presents results from the sixth year of the study. Separate abstracts have been prepared for each of the 4 studies reported for inclusion in the Energy Data Base. (DMC)

  11. Circles Disturbed The Interplay of Mathematics and Narrative

    CERN Document Server

    Doxiadis, Apostolos

    2012-01-01

    Circles Disturbed brings together important thinkers in mathematics, history, and philosophy to explore the relationship between mathematics and narrative. The book's title recalls the last words of the great Greek mathematician Archimedes before he was slain by a Roman soldier--"Don't disturb my circles"--words that seem to refer to two radically different concerns: that of the practical person living in the concrete world of reality, and that of the theoretician lost in a world of abstraction. Stories and theorems are, in a sense, the natural languages of these two worlds--stories represent

  12. Wake behind circular cylinder excited by spanwise periodic disturbances

    Science.gov (United States)

    Sasaki, Yudai; Uchida, Iwami; Sakakibara, Jun

    2017-11-01

    We experimentally investigated the influence of flow control of the wake behind a circular cylinder excited by temporal periodic disturbances with spanwise phase variations using plasma actuators, motivated by reducing drag forces by suppressing development of large scale vortices. Plasma actuators were segmented in the spanwise direction, phase differences were given to adjacent electrodes. This experiment was conducted at Re =8000 and the wake was visualized by PIV. Compared to without forcing, when the phase difference is 180° and non-dimensional forcing frequency is higher than approximately 1.0, small vortices induced by periodic disturbance emerged in the free shear layer and the drag forces decreased.

  13. Acid-base disturbance in patients with cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens H; Bendtsen, Flemming; Møller, Søren

    2015-01-01

    PURPOSE: Acid-base disturbances were investigated in patients with cirrhosis in relation to hemodynamic derangement to analyze the hyperventilatory effects and the metabolic compensation. METHODS: A total of 66 patients with cirrhosis and 44 controls were investigated during a hemodynamic study......, and effects of unidentified ions (all Pacid-base disturbances could not be identified. CONCLUSION: Hypocapnic alkalosis is related to disease severity and hyperdynamic systemic circulation in patients with cirrhosis. The metabolic compensation includes...... alterations in serum albumin and water retention that may result in a delicate acid-base balance in these patients....

  14. Assessing anthropogenic and natural disturbances: forest response to similarly aged clearcut and tornado disturbances in an east Tennessee oak-hickory forest

    Science.gov (United States)

    Jonathan C. McGrath; Wayne K. Clatterbuck

    2013-01-01

    In February of 1993, an F3 tornado caused a large-scale disturbance in an east Tennessee oak-hickory (Quercus spp.-Carya spp.) forest. Vegetation response to anthropogenic and natural disturbances was compared by examining two tornado-disturbed areas and five adjacent 1-acre silvicultural clearcut areas unaffected by the tornado...

  15. Forest Disturbance Mapping Using Dense Synthetic Landsat/MODIS Time-Series and Permutation-Based Disturbance Index Detection

    Directory of Open Access Journals (Sweden)

    David Frantz

    2016-03-01

    Full Text Available Spatio-temporal information on process-based forest loss is essential for a wide range of applications. Despite remote sensing being the only feasible means of monitoring forest change at regional or greater scales, there is no retrospectively available remote sensor that meets the demand of monitoring forests with the required spatial detail and guaranteed high temporal frequency. As an alternative, we employed the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM to produce a dense synthetic time series by fusing Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS nadir Bidirectional Reflectance Distribution Function (BRDF adjusted reflectance. Forest loss was detected by applying a multi-temporal disturbance detection approach implementing a Disturbance Index-based detection strategy. The detection thresholds were permutated with random numbers for the normal distribution in order to generate a multi-dimensional threshold confidence area. As a result, a more robust parameterization and a spatially more coherent detection could be achieved. (i The original Landsat time series; (ii synthetic time series; and a (iii combined hybrid approach were used to identify the timing and extent of disturbances. The identified clearings in the Landsat detection were verified using an annual woodland clearing dataset from Queensland’s Statewide Landcover and Trees Study. Disturbances caused by stand-replacing events were successfully identified. The increased temporal resolution of the synthetic time series indicated promising additional information on disturbance timing. The results of the hybrid detection unified the benefits of both approaches, i.e., the spatial quality and general accuracy of the Landsat detection and the increased temporal information of synthetic time series. Results indicated that a temporal improvement in the detection of the disturbance date could be achieved relative to the irregularly spaced Landsat

  16. Childhood Abuse, Body Image Disturbance, and Eating Disorders.

    Science.gov (United States)

    Schaaf, Kristin K.; McCanne, Thomas R.

    1994-01-01

    This study examined the relationships among childhood sexual and physical abuse, body image disturbance, and eating disorder symptomatology in college students, of whom 29 had been sexually abused, 32 physically abused, and 29 nonabused. There was no evidence that child sexual or physical abuse was associated with the development of body image…

  17. Book Review Overcoming Body Image Disturbance: A Programme ...

    African Journals Online (AJOL)

    Book Review Overcoming Body Image Disturbance: A Programme for People with Eating Disorders By Lorraine Bell and Jenny Rushforth (2008). Carla Dukas. Abstract. Routledge, London Paperback, ISBN 978-0-415-42330-4, ZAR 393 160 pages40. Journal of Child and Adolescent Mental Health 2008, 20(2): 133–134.

  18. Disturbance and the frequency of root suckering in an invasive ...

    African Journals Online (AJOL)

    The ecology of clonal species has rarely been studied in savannas. Dichrostachys cinerea, a common invasive shrub in southern African savannas, forms root suckers. This paper examines the effect of disturbance type and frequency on this form of clonal spread. Small plants were excavated (n = 370) at 11 sites exposed ...

  19. Development of Transition Programs for Adolescents with Serious Emotional Disturbances.

    Science.gov (United States)

    Bulen, Julia; Bullis, Michael

    This paper reports on an ongoing 3-year project which has worked with three school sites to identify program and staff needs and then develop a tailored intervention to improve program services for adolescent students with severe emotional disturbances (SED). Necessary characteristics of effective transition programs for this population are…

  20. Emotional Disturbance. Fact Sheet = Problemas Emocionales. Hojas Informativas Sobre Discapacidades.

    Science.gov (United States)

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet, written in both English and Spanish, provides a definition, information on incidence, typical characteristics, and educational implications of emotional disturbance. The definition is from the Individuals with Disabilities Education Act (IDEA) and incidence in 1999-2000 is reported as about 470,000 children and youth. Educational…

  1. Dynamics of a railway vehicle on a laterally disturbed track

    DEFF Research Database (Denmark)

    Christiansen, Lasse Engbo; True, Hans

    2017-01-01

    In this article a theoretical investigation of the dynamics of a railway bogie running on a tangent track with a periodic disturbance of the lateral track geometry is presented. The dynamics is computed for two values of the speed of the vehicle in combination with different values...

  2. Treating Emotionally Disturbed Youth: Home-Based Family Focused Intervention.

    Science.gov (United States)

    Anders-Cibik, Pamela; And Others

    Home-based intervention services for emotionally disturbed youth are also commonly known as in-home services, family-centered services, family-based services, intensive family services, or family preservation services. They have developed as a way to deal with serious family problems that often result in the removal of a child or adolescent from…

  3. Chronic Sleep Disturbance Impairs Glucose Homeostasis in Rats

    NARCIS (Netherlands)

    Barf, R. Paulien; Meerlo, Peter; Scheurink, Anton J. W.

    2010-01-01

    Epidemiological studies have shown an association between short or disrupted sleep and an increased risk for metabolic disorders. To assess a possible causal relationship, we examined the effects of experimental sleep disturbance on glucose regulation in Wistar rats under controlled laboratory

  4. Riparian vegetation response to altered disturbance and stress regimes

    Science.gov (United States)

    Shafroth, P.B.; Stromberg, J.C.; Patten, D.T.

    2002-01-01

    Management of terrestrial carbon fluxes is being proposed as a means of increasing the amount of carbon sequestered in the terrestrial biosphere. This approach is generally viewed only as an interim strategy for the coming decades while other longer-term strategies are developed and implemented — the most important being the direct reduction of carbon emissions. We are concerned that the potential for rapid, disturbance-induced losses may be much greater than is currently appreciated, especially by the decision-making community. Here we wish to: (1) highlight the complex and threshold-like nature of disturbances — such as fire and drought, as well as the erosion associated with each — that could lead to carbon losses; (2) note the global extent of ecosystems that are at risk of such disturbance-induced carbon losses; and (3) call for increased consideration of and research on the mechanisms by which large, rapid disturbance-induced losses of terrestrial carbon could occur. Our lack of ability as a scientific community to predict such ecosystem dynamics is precluding the effective consideration of these processes into strategies and policies related to carbon management and sequestration. Consequently, scientists need to do more to improve quantification of these potential losses and to integrate them into sound, sustainable policy options.

  5. A quest for species-level indicator values for disturbance

    Czech Academy of Sciences Publication Activity Database

    Herben, Tomáš; Chytrý, M.; Klimešová, Jitka

    2016-01-01

    Roč. 27, č. 3 (2016), s. 628-636 ISSN 1100-9233 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : disturbance * severity * frequency Subject RIV: EF - Botanics Impact factor: 2.924, year: 2016

  6. Studies on circadian rhythm disturbances and melatonin in delirium

    NARCIS (Netherlands)

    de Jonghe, A.-M.

    2014-01-01

    The circadian sleep/wake rhythm disturbances that are seen in delirium and the role of melatonin supplementation provide a new angle in delirium research. More research is needed to determine the role of melatonin in the pathophysiological mechanisms of delirium and to determine whether the

  7. Landscape level analysis of disturbance regimes in protected areas ...

    Indian Academy of Sciences (India)

    The present study has emphasized the moderate to low disturbance regimes in protected areas, which infer low biotic pressure and conservation effectiveness of PA network in Rajasthan. The spatial information generated on PAs is of valuable use for forest management and developing conservation strategies.

  8. Spatially Estimating Disturbance of Harbor Seals (Phoca vitulina.

    Directory of Open Access Journals (Sweden)

    John K Jansen

    Full Text Available Tidewater glacial fjords in Alaska provide habitat for some of the largest aggregations of harbor seals (Phoca vitulina, with calved ice serving as platforms for birthing and nursing pups, molting, and resting. These fjords have also been popular destinations for tour ships for more than a century, with dramatic increases in vessel traffic since the 1980s. Seals on ice are known to flush into the water when approached by tour ships, but estimating the exposure to disturbance across populations is difficult. Using aerial transect sampling while simultaneously tracking vessel movements, we estimated the spatial overlap between seals on ice and cruise ships in Disenchantment Bay, Alaska, USA. By integrating previously estimated rates of disturbance as a function of distance with an 'intensity surface' modeled spatially from seal locations in the surveys, we calculated probabilities of seals flushing during three separate ship visits. By combining our estimate of seals flushed with a modeled estimate of the total fjord population, we predict that up to 14% of the seals (up to 11% of pups hauled out would have flushed into the water, depending on the route taken by ships relative to seal aggregations. Such high potential for broad-scale disturbance by single vessels (when up to 4 ships visit per day was unexpected and underscores the need to 1 better understand long-term effects of disturbance; 2 regularly monitor populations exposed to high vessel traffic; and 3 develop conservation measures to reduce seal-ship overlap.

  9. Incorporating effects of natural disturbances in managed ecosystems

    Science.gov (United States)

    John T. Rotenberry; Robert J. Cooper; Joseph M. Wunderle; Kimberley G. Smith

    1993-01-01

    We briefly review the effects of climate (particularly drought and hurricanes), insect outbreaks, and fire on populations of migrant birds. An important feature of all of these natural disturbances is that they occur over a variety of spatial and temporal scales, thus precluding any simple generalization of their effects or of methods for mitigating those effects. We...

  10. Simulation of landscape disturbances and the effect of climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W.L.

    1993-04-01

    Altering the natural disturbance regime of a landscape produces changes in the structure of that landscape as the landscape adjusts to the new disturbance regime. A computer simulation model was designed to enable analyses of the longterm changes to be expected in landscapes as their disturbance regime changes. The model, DISPATCH, is the first dynamic spatial simulation model built around a geographical information system (GIS). The model also includes a new set of programs, the r.le programs, that is the first set of programs designed for calculating landscape structure measures within a GIS. The DISPATCH model was used, to analyze the effects of human alterations of disturbance regimes and global change on landscape structure. Landscapes do not adjust quickly to these alterations based on available data. Landscapes subjected to warming or to longterm fire suppression experience a decline in patch richness, Shannon diversity, the amount of edge and contrast, but an increase in distance between patches, angular second moment (texture measure) and patch size. In contrast, landscapes subjected to cooling, the short-term effects of fire suppression, fragmentation, or traditional prescribed burning tend to respond with increasing richness, Shannon diversity, edge, and contrast, but declining distance, angular second moment, and size. The pattern of response is different at different scales, with important implications for species.

  11. Erosion over time on severely disturbed granitic soils: a model

    Science.gov (United States)

    W. F. Megahan

    1974-01-01

    A negative exponential equation containing three parameters was derived to describe time trends in surface erosion on severely disturbed soils. Data from four different studies of surface erosion on roads constructed from the granitic materials found in the Idaho Batholith were used to develop equation parameters. The evidence suggests that surface "armoring...

  12. Advances in modeling soil erosion after disturbance on rangelands

    Science.gov (United States)

    Research has been undertaken to develop process based models that predict soil erosion rate after disturbance on rangelands. In these models soil detachment is predicted as a combination of multiple erosion processes, rain splash and thin sheet flow (splash and sheet) detachment and concentrated flo...

  13. Aspects of habitat disturbance by Cape porcupines in a savanna ...

    African Journals Online (AJOL)

    Habitat disturbances by Cape porcupines (Hystrix africaeaustralis)in a savanna ecosystem were investigated at Nylsvley Nature Reserve by using transect line surveys for signs of porcupine foraging activities. The density of foraging diggings was significantly higher in Burkea savanna than in Acacia savanna. A significantly ...

  14. Do not neglect surroundings in restoration of disturbed sites

    Czech Academy of Sciences Publication Activity Database

    Prach, Karel; Karešová, P.; Jírová, Alena; Dvořáková, H.; Konvalinková, P.; Řehounková, Klára

    2015-01-01

    Roč. 23, č. 3 (2015), s. 310-314 ISSN 1061-2971 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional support: RVO:67985939 Keywords : disturbed sites * succession * restoration Subject RIV: EH - Ecology, Behaviour Impact factor: 1.891, year: 2015

  15. Behaviour of organised disturbances in fully developed turbulent ...

    Indian Academy of Sciences (India)

    In our earlier work we have shown the relevance of stability theory in understanding the sustenance of turbulence in turbulent boundary layers. Here we adopt the same model to study the evolution of organised disturbances in turbulent channel flow. Since the dominant modes are wall modes we find that the stability ...

  16. Biomarker responses of mussels exposed to earthquake disturbances

    Science.gov (United States)

    Chandurvelan, Rathishri; Marsden, Islay D.; Glover, Chris N.; Gaw, Sally

    2016-12-01

    The green-lipped mussel, Perna canaliculus is recognised as a bioindicator of coastal contamination in New Zealand (NZ). Mussels (shell length 60-80 mm) were collected from three intertidal areas of Canterbury in the South Island of NZ prior to extreme earthquake disturbances on 22nd February 2011, and 9 months later in October 2011. Trace elements, including arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), were measured in the gills, digestive gland, foot and mantle. Metal levels in tissues were site specific, and mostly unaffected by earthquake disturbances. Physiological biomarkers were negatively affected by earthquake disturbances and mussels from the Port of Lyttelton had higher negative scope for growth post-earthquake. Metallothionein-like protein in the digestive gland correlated with metal content of tissues, as did catalase activity in the gill and lipid peroxidation values for the digestive gland. This research demonstrates that physiological and other biomarkers are effective at detecting the effects of multiple stressors following seismic disturbances.

  17. Television Images and Adolescent Girls' Body Image Disturbance.

    Science.gov (United States)

    Botta, Renee A.

    1999-01-01

    Contributes to scholarship on the effects of media images on adolescents, using social-comparison theory and critical-viewing theory. Finds that media do have an impact on body-image disturbance. Suggests that body-image processing is the key to understanding how television images affect adolescent girls' body-image attitudes and behaviors. (SR)

  18. Hypothesis: patient with possible disturbance in programmed cell death

    NARCIS (Netherlands)

    Hennekam, R. C.; Cohen, M. M.

    1995-01-01

    Programmed cell death is a physiological process in mammalian development by which specific types of cells are eliminated, and, hence, is of fundamental importance in normal human embryogenesis. A patient is described with multiple congenital anomalies that may be explained by a disturbance of

  19. Sleep Disturbances in Patients with Rheumatoid Arthritis | Abbasi ...

    African Journals Online (AJOL)

    BACKGROUND: Sleep problems are frequent in chronic diseases like rheumatoid arthritis (RA). The present study was conducted to determine frequency of sleep disturbances and their relations with disease severity. METHODS: The present case-control study was performed on 100 rheumatoid patients who were referred ...

  20. Fluent Persuasive Writing with Counterarguments for Students with Emotional Disturbance

    Science.gov (United States)

    Mastropieri, Margo A.; Scruggs, Thomas E.; Cerar, Nancy Irby; Allen-Bronaugh, Dannette; Thompson, Catherine; Guckert, Mary; Leins, Pat; Hauth, Clara; Cuenca-Sanchez, Yojanna

    2014-01-01

    Twelve seventh- and eighth-grade students with emotional disturbance participated in a multiple probe, multiple baseline design two-phase intervention study to improve persuasive writing skills. The first phase after baseline taught students to plan and write persuasive essays including counterarguments. In the second phase, students were taught…

  1. Child Abuse and Aggression among Seriously Emotionally Disturbed Children

    Science.gov (United States)

    Ford, Julian D.; Fraleigh, Lisa A.; Connor, Daniel F.

    2010-01-01

    Abused children may be at risk for problems with aggression. In a sample of 397 seriously emotionally disturbed children, reactive aggression was associated with documented history of physical abuse but not sexual abuse. Girls were equally likely to be classified as reactively aggressive regardless of physical abuse history, but boys with physical…

  2. Modeling dynamic behavior of superconducting maglev systems under external disturbances

    Science.gov (United States)

    Huang, Chen-Guang; Xue, Cun; Yong, Hua-Dong; Zhou, You-He

    2017-08-01

    For a maglev system, vertical and lateral displacements of the levitation body may simultaneously occur under external disturbances, which often results in changes in the levitation and guidance forces and even causes some serious malfunctions. To fully understand the effect of external disturbances on the levitation performance, in this work, we build a two-dimensional numerical model on the basis of Newton's second law of motion and a mathematical formulation derived from magnetoquasistatic Maxwell's equations together with a nonlinear constitutive relation between the electric field and the current density. By using this model, we present an analysis of dynamic behavior for two typical maglev systems consisting of an infinitely long superconductor and a guideway of different arrangements of infinitely long parallel permanent magnets. The results show that during the vertical movement, the levitation force is closely associated with the flux motion and the moving velocity of the superconductor. After being disturbed at the working position, the superconductor has a disturbance-induced initial velocity and then starts to periodically vibrate in both lateral and vertical directions. Meanwhile, the lateral and vertical vibration centers gradually drift along their vibration directions. The larger the initial velocity, the faster their vibration centers drift. However, the vertical drift of the vertical vibration center seems to be independent of the direction of the initial velocity. In addition, due to the lateral and vertical drifts, the equilibrium position of the superconductor in the maglev systems is not a space point but a continuous range.

  3. Landslide disturbance: implications for chemical weathering, vegetation and carbon cycling

    Science.gov (United States)

    Milledge, D.; Hilton, R. G.

    2011-12-01

    Landslides disturb physical and ecological systems by periodically stripping away soil and vegetation. This turnover influences the makeup and productivity of vegetation as well as the chemical weathering rate for the soil. Recent research has highlighted these links focusing on landslide magnitude and frequency and calculating turnover on a catchment wide basis. However, landslide probability and therefore turnover is not uniform in space. We investigate the influence of this spatial variability on the frequency distribution of landslide turnover and its implications for: vegetation disturbance, carbon cycling and chemical weathering. We use first synthetic landslide risk distributions then real distributions from the Western Southern Alps and Oregon Coast Range. We use these to generate turnover distributions then compare these with the turnover rate predicted assuming spatially uniform landslide probability. We use published relations to work through the implications for: vegetation disturbance, carbon cycling and chemical weathering. We find that: 1) landslide turnover rates are too slow even in the most active parts of the landscape to chronically disturb the vegetation; 2) the changes to productivity are generally subtle leading to only minor changes in the carbon flux; and 3) landslide related chemical weathering rates are reduced in areas with strongly non-uniform landslide risk distributions.

  4. Forest disturbance type differentially affects seasonal moose forage

    Science.gov (United States)

    R.A. Lautenschlager; Hewlette S. Crawford; Martin R. Stokes; Timothy L. Stone

    1997-01-01

    We examined the effects of forest disturbance on forage availability, moose (Alces alces) seasonal forage selection, and predicted in vivo digestibility in eastern Maine. Wet-mass estimates and dry-mass conversions of species consumed by 3 tamed moose were made throughout the year (late winter, early spring, late spring, summer, fall, early winter)...

  5. Comparison Of Power Quality Disturbances Classification Based On Neural Network

    Directory of Open Access Journals (Sweden)

    Nway Nway Kyaw Win

    2015-07-01

    Full Text Available Abstract Power quality disturbances PQDs result serious problems in the reliability safety and economy of power system network. In order to improve electric power quality events the detection and classification of PQDs must be made type of transient fault. Software analysis of wavelet transform with multiresolution analysis MRA algorithm and feed forward neural network probabilistic and multilayer feed forward neural network based methodology for automatic classification of eight types of PQ signals flicker harmonics sag swell impulse fluctuation notch and oscillatory will be presented. The wavelet family Db4 is chosen in this system to calculate the values of detailed energy distributions as input features for classification because it can perform well in detecting and localizing various types of PQ disturbances. This technique classifies the types of PQDs problem sevents.The classifiers classify and identify the disturbance type according to the energy distribution. The results show that the PNN can analyze different power disturbance types efficiently. Therefore it can be seen that PNN has better classification accuracy than MLFF.

  6. Impact of global warming on cyclonic disturbances over south Asian ...

    Indian Academy of Sciences (India)

    This change is within the lim- its of natural variability (the frequency of cyclonic disturbances in baseline has mean 8 and standard deviation 2.1). The decrease in monsoon CDs is mainly due to reduction in July and August sys- tems as can be seen from table 1. The intensity of the synoptic system is the maximum intensity.

  7. Stochastic disturbance rejection in model predictive control by randomized algorithms

    NARCIS (Netherlands)

    Batina, Ivo; Stoorvogel, Antonie Arij; Weiland, Siep

    2001-01-01

    In this paper we consider model predictive control with stochastic disturbances and input constraints. We present an algorithm which can solve this problem approximately but with arbitrary high accuracy. The optimization at each time step is a closed loop optimization and therefore takes into

  8. Sleep disturbances in a clinical forensic psychiatric population

    NARCIS (Netherlands)

    Kamphuis, Jeanine; Karsten, Julie; de Weerd, Al; Lancel, Marike

    2013-01-01

    Objective: Poor sleep is known to cause detrimental effects on the course of diverse psychiatric disorders and is a putative risk factor for hostility and aggression. Thus, sleep may be crucial in forensic psychiatric practice. However, little is known about the prevalence of sleep disturbances in

  9. Sleep-related respiratory disturbance and dementia in elderly females.

    Science.gov (United States)

    Mant, A; Saunders, N A; Eyland, A E; Pond, C D; Chancellor, A H; Webster, I W

    1988-09-01

    Sleep-related respiratory disturbance was studied with a microprocessor-based portable monitoring system in female residents of a retirement village aged greater than or equal to 75 years. Comparisons were made between 29 demented subjects Mini-Mental State Examination Score (MMSE) less than 21 and 48 controls (MMSE greater than 25). Respiratory disturbance index (RDI, the number of episodes of apnea and hypopnea/hour of total sleep time) was higher in the demented subjects: mean RDI (+/- SD) 18.5 +/- 18.6 vs 7.3 +/- 10.8, p = .004. The number of minutes per hour of sleep spent with disturbed breathing was greater in demented subjects than in controls (p = .01). These differences between demented subjects and controls persisted after adjustment for age and relevant medical history. Other possible confounders, namely body mass index and use of sedatives, were not significant. We conclude that respiratory disturbance during sleep is more prevalent in elderly demented females than in controls.

  10. Intestinal mast cells in gut inflammation and motility disturbances

    NARCIS (Netherlands)

    de Winter, Benedicte Y.; van den Wijngaard, Rene M.; de Jonge, Wouter J.

    2012-01-01

    Mast cells may be regarded as prototypes of innate immune cells that can be controlled by neuronal mediators. Their activation has been implicated in many types of neuro-inflammatory responses, and related disturbances of gut motility, via direct or indirect mechanisms that involve several

  11. Disturbance metrics predict a wetland Vegetation Index of Biotic Integrity

    Science.gov (United States)

    Stapanian, Martin A.; Mack, John; Adams, Jean V.; Gara, Brian; Micacchion, Mick

    2013-01-01

    Indices of biological integrity of wetlands based on vascular plants (VIBIs) have been developed in many areas in the USA. Knowledge of the best predictors of VIBIs would enable management agencies to make better decisions regarding mitigation site selection and performance monitoring criteria. We use a novel statistical technique to develop predictive models for an established index of wetland vegetation integrity (Ohio VIBI), using as independent variables 20 indices and metrics of habitat quality, wetland disturbance, and buffer area land use from 149 wetlands in Ohio, USA. For emergent and forest wetlands, predictive models explained 61% and 54% of the variability, respectively, in Ohio VIBI scores. In both cases the most important predictor of Ohio VIBI score was a metric that assessed habitat alteration and development in the wetland. Of secondary importance as a predictor was a metric that assessed microtopography, interspersion, and quality of vegetation communities in the wetland. Metrics and indices assessing disturbance and land use of the buffer area were generally poor predictors of Ohio VIBI scores. Our results suggest that vegetation integrity of emergent and forest wetlands could be most directly enhanced by minimizing substrate and habitat disturbance within the wetland. Such efforts could include reducing or eliminating any practices that disturb the soil profile, such as nutrient enrichment from adjacent farm land, mowing, grazing, or cutting or removing woody plants.

  12. Differential reactions to anthropogenic disturbance by two ground ...

    African Journals Online (AJOL)

    Both ABO and KG significantly altered their behavioural responses to disturbance from pre-breeding to breeding. These results emphasise the need to have a buffer zone surrounding breeding areas excluding human presence to allow for the successful breeding of ABO. Keywords: African Black Oystercatcher, buffer zone, ...

  13. Are sleep disturbances preclinical markers of Parkinson’s disease?

    DEFF Research Database (Denmark)

    Brito dos Santos, Altair; Kohlmeier, Kristi Anne; Barreto, George

    2015-01-01

    Parkinson’s disease (PD) is a neurobehavioral disorder characterized by motor symptoms and signs, and non-motor abnormalities such as olfactory dysfunction, pain, sleep disorders and cognitive impairment. Amongst these alterations, sleep disturbances play an important role in the pathology...

  14. Disturbance, diversity and distributions in Central African rain forest

    NARCIS (Netherlands)

    Gemerden, van B.S.

    2004-01-01

    The aim of this study is to gain insight in the impact of human land use on plant community composition, diversity and levels of endemism in Central African rain forest. Human disturbance in this region is causing large-scale habitat degradation. The two most widespread forms of land use are

  15. Operational behaviour of a reactor normal operation and disturbances

    International Nuclear Information System (INIS)

    Geyer, K.H.

    1982-01-01

    During normal operation, the following topics are dealt with: primary and secondary coolant circuits - full load operation - start-up and shutdown - steady state part load diagramm. During disturbances and incidents, the following procedures are discussed: identification and detection of the events - automatic actions - manual actions of the operator - provided indications - explanation of actuated systems - basic information of reactor protection system. (RW)

  16. Disturbance rejection in formation keeping control of nonholonomic wheeled robots

    NARCIS (Netherlands)

    Jafarian, Matin; Vos, Ewoud; De Persis, Claudio; Scherpen, Jacquelien; Schaft, van der Arjan

    2016-01-01

    This paper presents the results of formation keeping control of a group of nonholonomic wheeled robots within the port-Hamiltonian framework and in the presence of matched input disturbances. Two scenarios on the internal damping of the dynamics of the robots are considered: strictly output passive

  17. Extinction risk in successional landscapes subject to catastrophic disturbances.

    Science.gov (United States)

    David Boughton; Urmila. Malvadkar

    2002-01-01

    We explore the thesis that stochasticity in successional-disturbance systems can be an agent of species extinction. The analysis uses a simple model of patch dynamics for seral stages in an idealized landscape; each seral stage is assumed to support a specialist biota. The landscape as a whole is characterized by a mean patch birth rate, mean patch size, and mean...

  18. Severe psychological disturbance resulting from abuse of nasal decongestants.

    Science.gov (United States)

    Blackwood, G W

    1982-04-01

    A case is reported in which a lady suffered long-term personality change, a paranoid psychosis of several months duration, and an acute delirium, secondary to abuse of Vicks Sinex Nasal Spray and Vicks Vaporub. The problems were reversible on withdrawal of these well used products which have not previously been reported to cause psychological disturbance.

  19. Comprehensive Assessment of Emotional Disturbance: A Cross-Validation Approach

    Science.gov (United States)

    Fisher, Emily S.; Doyon, Katie E.; Saldana, Enrique; Allen, Megan Redding

    2007-01-01

    Assessing a student for emotional disturbance is a serious and complex task given the stigma of the label and the ambiguities of the federal definition. One way that school psychologists can be more confident in their assessment results is to cross validate data from different sources using the RIOT approach (Review, Interview, Observe, Test).…

  20. Plant response strategies to stress and disturbance: the case of ...

    Indian Academy of Sciences (India)

    Unknown

    Plant response strategies to stress and disturbance: the case of aquatic plants. MICHÈLE TRÉMOLIÈRES. Center of Vegetal Ecology and Hydrology, CEVH UMR MA 101 ULP/ENGEES,. 28 rue Goethe F-67083 Strasbourg, France. (Email, michele.tremolieres@bota-ulp.u-strasbg.fr). The environmental factors controlling the ...

  1. Use of Videotape Feedback with Severely Disturbed Adolescents.

    Science.gov (United States)

    Michel, Jane; Blitstein, Sheldon

    1979-01-01

    Summarizes the design and effects of a group therapy project using videotape feedback with seriously disturbed adolescents. Offers anecdotal evidence that the feedback facilitated the correction of the participants' distorted body images, low self-esteem, lack of capacity for self-observation, and poor peer relationships. (SS)

  2. Using landscape disturbance and succession models to support forest management

    Science.gov (United States)

    Eric J. Gustafson; Brian R. Sturtevant; Anatoly S. Shvidenko; Robert M. Scheller

    2010-01-01

    Managers of forested landscapes must account for multiple, interacting ecological processes operating at broad spatial and temporal scales. These interactions can be of such complexity that predictions of future forest ecosystem states are beyond the analytical capability of the human mind. Landscape disturbance and succession models (LDSM) are predictive and...

  3. Impacts of geo-physical factors and human disturbance on ...

    African Journals Online (AJOL)

    ... in the Xiaomengyang Section of Xishuangbanna Nature Reserve (XNR) using multivariate analysis to understand the impacts of geo-physical factors and human disturbance on vegetation along the highway corridor. We found that native forests were the best habitat for protected/endangered species and native species.

  4. Diversity of mesofauna and macrofauna in protected and disturbed ...

    African Journals Online (AJOL)

    High biodiversity of the soil fauna can be an indicator of soil fertility and its ability to sustain complex food chain, but fauna diversity alone is rarely used as a measure of these attributes. In this study we ... These results demonstrate the need for proper soil management practices to restore biodiversity loss in disturbed soils.

  5. Propagation of disturbances as voltage fluctuations in transmission networks

    Directory of Open Access Journals (Sweden)

    Albert Hermina

    2016-08-01

    Full Text Available Significant changes occurred in the power system in Romania in recent years by reducing the power used in the system, the number of classic power sources in operation as well as by implementing renewable energy sources, have determined short circuit power reduction (node rigidity in the points where disturbing users are connected, that in the absence of adequate measures, result in disturbances above acceptable levels. The paper analyzes two power systems areas in which are connected users that cause voltage fluctuation. Disturbances as voltage fluctuations resulting in these nodes may exceed the acceptable values and can spread in the transmission network affecting power quality over large system areas. The analysis conducted reveals the influence of short circuit power in nodes where these users are connected and highlights the fact that in some cases (e.g. lines out of operation for maintenance, shutdown of classic units in the area the disturbances in the transmission network sent to the users at lower voltages may have values above those allowed. Technical Code of existing power transmission network makes no reference to voltage fluctuations, as a rule, in the electricity transmission network was considered that this phenomenon should not exist.

  6. Pseudologia fantastica and gender identity disturbance in a Chinese male.

    Science.gov (United States)

    Leung, C M; Lai, K; Shum, K; Lee, G

    1995-06-01

    A Chinese patient with pathological lying (pseudologia fantastica) and gender identity disturbance is described. The stories "save face" and lack a truly self-aggrandising quality. The importance of keeping "face" and maintaining modest behaviour in the Chinese culture is central to the psychopathology.

  7. Inter-specific variation in avian responses to human disturbance

    Science.gov (United States)

    Daniel T. Blumstein; Esteban Fernandez-Juricic; Patrick A. Zollner; Susan C. Garity

    2005-01-01

    1. Increasing urbanization and recreational activities around and within biodiversity hotspots require an understanding of how to reduce the impacts of human disturbance on more than a single species; however, we lack a general framework to study multiple species. One approach is to expand on knowledge about the theory of anti-predator behaviour to understand and...

  8. Further Validation of the Iowa Sleep Disturbances Inventory

    Science.gov (United States)

    Koffel, Erin

    2011-01-01

    This study examined the reliability and validity of an expanded version of the Iowa Sleep Disturbances Inventory (ISDI; Koffel & Watson, 2010) in 2 samples (219 college students and 200 psychiatric patients). The expanded ISDI includes the scales Sleep Paralysis and Sleep Hallucinations. These scales, along with the Nightmares scale, help define a…

  9. Behaviour of organised disturbances in fully developed turbulent ...

    Indian Academy of Sciences (India)

    Abstract. In our earlier work we have shown the relevance of stability theory in understanding the sustenance of turbulence in turbulent boundary layers. Here we adopt the same model to study the evolution of organised disturbances in turbulent channel flow. Since the dominant modes are wall modes we find that the ...

  10. Maintenance of fish diversity on disturbed coral reefs

    Science.gov (United States)

    Wilson, S. K.; Dolman, A. M.; Cheal, A. J.; Emslie, M. J.; Pratchett, M. S.; Sweatman, H. P. A.

    2009-03-01

    Habitat perturbations play a major role in shaping community structure; however, the elements of disturbance-related habitat change that affect diversity are not always apparent. This study examined the effects of habitat disturbances on species richness of coral reef fish assemblages using annual surveys of habitat and 210 fish species from 10 reefs on the Great Barrier Reef (GBR). Over a period of 11 years, major disturbances, including localised outbreaks of crown-of-thorns sea star ( Acanthaster planci), severe storms or coral bleaching, resulted in coral decline of 46-96% in all the 10 reefs. Despite declines in coral cover, structural complexity of the reef framework was retained on five and species richness of coral reef fishes maintained on nine of the disturbed reefs. Extensive loss of coral resulted in localised declines of highly specialised coral-dependent species, but this loss of diversity was more than compensated for by increases in the number of species that feed on the epilithic algal matrix (EAM). A unimodal relationship between areal coral cover and species richness indicated species richness was greatest at approximately 20% coral cover declining by 3-4 species (6-8% of average richness) at higher and lower coral cover. Results revealed that declines in coral cover on reefs may have limited short-term impact on the diversity of coral reef fishes, though there may be fundamental changes in the community structure of fishes.

  11. Variation of surface electric field during geomagnetic disturbed ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 124; Issue 8. Variation of surface electric field ... Diurnal variation of surface electric field measured at Maitri shows a similar variation with worldwide thunderstorm activity, whereas the departure of the field is observed during disturbed periods. This part of the field ...

  12. Rill erosion in natural and disturbed forests: 1. Measurements

    Science.gov (United States)

    P. R. Robichaud; J. W. Wagenbrenner; R. E. Brown

    2010-01-01

    Rill erosion can be a large portion of the total erosion in disturbed forests, but measurements of the runoff and erosion at the rill scale are uncommon. Simulated rill erosion experiments were conducted in two forested areas in the northwestern United States on slopes ranging from 18 to 79%. We compared runoff rates, runoff velocities, and sediment flux rates from...

  13. The reaction of the atmosphere to solar disturbances

    Science.gov (United States)

    Mikhnevich, V. V.

    1979-01-01

    The effect of solar flares on the thermosphere and the troposphere is investigated. It is found that during periods of geoeffect solar disturbances, there is a connection between phenomena in the upper and lower atmospheres and that variations in atmospheric parameters correlate with changes in the geomagnetic index.

  14. Multi-taxa trait and functional responses to physical disturbance.

    Science.gov (United States)

    Pedley, Scott M; Dolman, Paul M

    2014-11-01

    Examining assemblage trait responses to environmental stressors extends our understanding beyond patterns of taxonomic diversity and composition, with results potentially transferable among bioregions. But the degree to which trait responses may be generalized across taxonomic groups remains incompletely understood. We compared trait responses among carabids, spiders and plants to an experimentally manipulated gradient of physical disturbance, replicated in open habitats within a forested landscape. Recolonization of recently disturbed habitats is expected to favour species with traits that promote greater dispersal ability, independent of taxa. We specifically predicted that physical disturbance would increase the representation of carabids with smaller body size, wings or wing dimorphism, spiders able to disperse aerially, and plants with therophyte life-history and wind-dispersed seed. We sampled 197 arthropod species (14,738 individuals) and 164 species of plant. The strength of association between each trait and the disturbance intensity was quantified by correlating matrices of species by traits, species abundance by sites and sites by environment, with significance assessed by comparison with a null model. Responses of biological traits varied among taxa but could be consistently interpreted in terms of dispersal ability. Trait shifts for carabid and plant assemblages were as predicted and correspond to those observed in other disturbance regimes. Assemblages after disturbance comprised smaller and winged carabids, and smaller plants with wind-dispersed seed, consistent with selection for species with better dispersal ability. In contrast, aerial dispersal did not appear important in spider recolonization, instead terrestrial dispersal ability was suggested by the increased abundance of larger-bodied and cursorial species. However, larger spider body size was also associated with an active-hunting strategy, also favoured in the post-disturbance environment

  15. Inverting Coseismic TEC Disturbances for Neutral Atmosphere Pressure Wave

    Science.gov (United States)

    Lee, R. F.; Mikesell, D.; Rolland, L.

    2017-12-01

    Research from the past 20 years has shown that we can detect coseismic disturbances in the total electron content (TEC) using global navigation space systems (GNSS). In the near field, TEC disturbances are created by the direct wave from rupture on the surface. This pressure wave travels through the neutral atmosphere to the ionosphere within about 10 minutes. This provides the opportunity to almost immediately characterize the source of the acoustic disturbance on the surface using methods from seismology. In populated areas, this could provide valuable information to first responders. To retrieve the surface motion amplitude information we must account for changes in the waveform caused by the geomagnetic field, motion of the satellites and the geometry of the satellites and receivers. One method is to use a transfer function to invert for the neutral atmosphere pressure wave. Gómez et al (2015) first employed an analytical model to invert for acoustic waves produced by Rayleigh waves propagating along the Earth's surface. Here, we examine the same model in the near field using the TEC disturbances from the direct wave produced by rupture at the surface. We compare results from the forward model against a numerical model that has been shown to be in good agreement with observations from the 2011 Van (Turkey) earthquake. We show the forward model predictions using both methods for the Van earthquake. We then analyze results for hypothetical events at different latitudes and discuss the reliability of the analytical model in each scenario. Gómez, D., R. Jr. Smalley, C. A. Langston, T. J. Wilson, M. Bevis, I. W. D. Dalziel, E. C. Kendrick, S. A. Konfal, M. J. Willis, D. A. Piñón, et al. (2015), Virtual array beamforming of GPS TEC observations of coseismic ionospheric disturbances near the Geomagnetic South Pole triggered by teleseismic megathrusts, J. Geophys. Res. Space Physics, 120, 9087-9101, doi:10.1002/2015JA021725.

  16. Effects of tropical montane forest disturbance on epiphytic macrolichens

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, Angel [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Prieto, Maria, E-mail: maria.prieto@urjc.es [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain); Gonzalez, Yadira [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Aragon, Gregorio [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain)

    2012-12-15

    The high diversity of epiphytes typical of undisturbed montane tropical forests has been negatively affected by continuous deforestation and forest conversion to secondary vegetation. Macrolichens are an important component of these epiphytes. Because their physiology is strongly coupled to humidity and solar radiation, we hypothesized that microclimatic changes derived from forest clearing and logging can affect the diversity of these poikilohydric organisms. In southern Ecuador, we examined three types of forests according to a disturbance gradient (primary forests, secondary forests, and monospecific forests of Alnus acuminata) for the presence/absence and coverage of epiphytic macrolichens that we identified on 240 trees. We found that total richness tended to decrease when the range of the disturbance increased. The impoverishment was particularly drastic for 'shade-adapted lichens', while the richness of 'heliophytic lichens' increased in the drier conditions of secondary growth. Epiphytic composition also differed significantly among the three types of forests, and the similarity decreased when the range of the disturbance was greater. We concluded that a span of 40 years of recovery by secondary vegetation was not enough to regenerate the diversity of epiphytic macrolichens that was lost due to forest disturbances. -- Highlights: Black-Right-Pointing-Pointer Tropical montane forest disturbance drastically reduced macrolichen diversity. Black-Right-Pointing-Pointer Species loss was most severe for the 'shade-adapted lichens' because high radiation is harmful to them. Black-Right-Pointing-Pointer In secondary forests lichen diversity of native forests was not regenerated. Black-Right-Pointing-Pointer The protection of remnants of primary tropical forest might help to preserve a diverse community of epiphytic macrolichens.

  17. Animal responses to natural disturbance and climate extremes: a review

    Science.gov (United States)

    Sergio, Fabrizio; Blas, Julio; Hiraldo, Fernando

    2018-02-01

    Natural disturbances, such as droughts, fires or hurricanes, are key drivers of ecological heterogeneity and ecosystem function. The frequency and severity of these episodes is unequivocally expected to increase in the coming decades, through the concerted action of climate change and anthropogenic pressures. This will impose severe challenges for many biota through exposure to rapidly changing conditions never experienced in the preceding millennia. Thus, it is urgently needed to gain a thorough understanding of animal responses and adaptations to disturbances in order to better estimate potential future impacts. Here, we review such adjustments and find that animals may respond to disturbances through changes in: (1) behaviour, such as altered mobility, emigration, resource-switching, refuge use, suspended animation, or biotic interactions; (2) life history traits, such as survival, aging, longevity, recruitment, reproductive restraint, breeding output, phenology and bet-hedging tactics; (3) morphology, such as rapid evolution through size-dependent mortality or facultative metamorphosis; (4) physiology, such as altered body condition, pathogen prevalence and transmission, or adrenocortical modulation of stress responses to emergency conditions; (5) genetic structure, such as changes in frequency of polymorphic variants or diversity-modulation through mortality bottlenecks. Individual-level responses scale up to population and community responses, such as altered density, population dynamics, distribution, local extinction and colonization, or assemblage structure and diversity. Overall, disturbances have pervasive effects on individuals, populations and communities of vertebrates and invertebrates of all realms, biomes, continents and ecosystems. Their rapidly increasing incidence and severity will bring unique study opportunities for researchers and novel, unpredictable challenges for managers, while demanding tougher choices and more proactive crisis

  18. Extinction Risk in Successional Landscapes Subject to Catastrophic Disturbances

    Directory of Open Access Journals (Sweden)

    David Boughton

    2002-12-01

    Full Text Available We explore the thesis that stochasticity in successional-disturbance systems can be an agent of species extinction. The analysis uses a simple model of patch dynamics for seral stages in an idealized landscape; each seral stage is assumed to support a specialist biota. The landscape as a whole is characterized by a mean patch birth rate, mean patch size, and mean lifetime for each patch type. Stochasticity takes three forms: (1 patch stochasticity is randomness in the birth times and sizes of individual patches, (2 landscape stochasticity is variation in the annual means of birth rate and size, and (3 turnover mode is whether a patch is eliminated by disturbance or by successional change. Analytical and numerical analyses of the model suggest that landscape stochasticity is the most important agent. Landscape stochasticity increases the extinction risk to species by increasing the risk that the habitat will fluctuate to zero, by reducing the mean abundance of species, and by increasing the variance in species abundance. The highest risk was found to occur in species that inhabit patches with short lifetimes. The results of this general model suggest an important mechanism by which climate change threatens biodiversity: an increase in the frequency of extreme climate events will probably cause pulses of disturbance during some time periods; these in turn would cause wider fluctuations in annual disturbance rates and thus increase the overall level of landscape stochasticity. However, the model also suggests that humans can manipulate landscape stochasticity to reduce risk. In particular, if managed disturbances were more evenly distributed in time, attrition of the regional biota might be prevented. Other work on the connection between patch dynamics and extinction risk assumes the absence of landscape stochasticity and thus overlooks an important component of risk to biodiversity.

  19. Role of Sleep Disturbance in the Trajectory of Alzheimer’s Disease

    Science.gov (United States)

    Kang, Dong Woo; Lee, Chang Uk; Lim, Hyun Kook

    2017-01-01

    Sleep disturbances such as insomnia, hypersomnia, and circadian rhythm disturbance are common in normal elderly and Alzheimer’s disease (AD) patients. To date, special attention has been paid to sleep disturbance in the clinical course of AD insofar as the interaction of sleep disturbance with the pathogenesis of AD may impact the clinical course and cognitive function of AD patients. This review covers the bidirectional relationship between sleep disturbance and AD pathogenesis; the associations between sleep disturbance and AD-specific neurotransmitters, brain structure, and aspects of sleep disturbance in each phase of AD; and the effects of sleep disturbance on the cognitive functions of patients in each phase of AD. We consider several factors required to exactly interpret the results and suggest a direction for future studies on the role of sleep disturbance in AD. PMID:28449556

  20. Net primary production of a temperate deciduous forest exhibits a threshold response to increasing disturbance severity.

    Science.gov (United States)

    Stuart-Haëntjens, Ellen J; Curtis, Peter S; Fahey, Robert T; Vogel, Christoph S; Gough, Christopher M

    2015-09-01

    The global carbon (C) balance is vulnerable to disturbances that alter terrestrial C storage. Disturbances to forests occur along a continuum of severity, from low-intensity disturbance causing the mortality or defoliation of only a subset of trees to severe stand- replacing disturbance that kills all trees; yet considerable uncertainty remains in how forest production changes across gradients of disturbance intensity. We used a gradient of tree mortality in an upper Great Lakes forest ecosystem to: (1) quantify how aboveground wood net primary production (ANPP,) responds to a range of disturbance severities; and (2) identify mechanisms supporting ANPPw resistance or resilience following moderate disturbance. We found that ANPPw declined nonlinearly with rising disturbance severity, remaining stable until >60% of the total tree basal area senesced. As upper canopy openness increased from disturbance, greater light availability to the subcanopy enhanced the leaf-level photosynthesis and growth of this formerly light-limited canopy stratum, compensating for upper canopy production losses and a reduction in total leaf area index (LAI). As a result, whole-ecosystem production efficiency (ANPPw/LAI) increased with rising disturbance severity, except in plots beyond the disturbance threshold. These findings provide a mechanistic explanation for a nonlinear relationship between ANPPw, and disturbance severity, in which the physiological and growth enhancement of undisturbed vegetation is proportional to the level of disturbance until a threshold is exceeded. Our results have important ecological and management implications, demonstrating that in some ecosystems moderate levels of disturbance minimally alter forest production.

  1. Scaling disturbance instead of richness to better understand anthropogenic impacts on biodiversity.

    Directory of Open Access Journals (Sweden)

    Stephen J Mayor

    Full Text Available A primary impediment to understanding how species diversity and anthropogenic disturbance are related is that both diversity and disturbance can depend on the scales at which they are sampled. While the scale dependence of diversity estimation has received substantial attention, the scale dependence of disturbance estimation has been essentially overlooked. Here, we break from conventional examination of the diversity-disturbance relationship by holding the area over which species richness is estimated constant and instead manipulating the area over which human disturbance is measured. In the boreal forest ecoregion of Alberta, Canada, we test the dependence of species richness on disturbance scale, the scale-dependence of the intermediate disturbance hypothesis, and the consistency of these patterns in native versus exotic species and among human disturbance types. We related field observed species richness in 1 ha surveys of 372 boreal vascular plant communities to remotely sensed measures of human disturbance extent at two survey scales: local (1 ha and landscape (18 km2. Supporting the intermediate disturbance hypothesis, species richness-disturbance relationships were quadratic at both local and landscape scales of disturbance measurement. This suggests the shape of richness-disturbance relationships is independent of the scale at which disturbance is assessed, despite that local diversity is influenced by disturbance at different scales by different mechanisms, such as direct removal of individuals (local or indirect alteration of propagule supply (landscape. By contrast, predictions of species richness did depend on scale of disturbance measurement: with high local disturbance richness was double that under high landscape disturbance.

  2. Quadrotor Proportional-Derivative Regulation for Nonzero Set Point on SO(3) with Disturbance Compensation

    Science.gov (United States)

    Herdjunanto, S.; Sandiwan, A. P.; Cahyadi, A. I.

    2017-04-01

    Disturbance compensation is a challenging problem in quadrotor control, especially in nonzero set point regulation. This paper presents proportional-derivative regulation for nonzero set point on SO(3) with disturbance compensation for quadrotor UAV. Quadrotor nonlinear kinematics and dynamics model in SO(3) are used to design the control law. Disturbance compensation is added to the control law by using the upper bound of the disturbance. The numerical simulation shows that the disturbance compensation is able to counter the disturbance effect and improve the bound of the state variables.

  3. Sediment redistribution during simulated benthic disturbance and its implications on deep seabed mining

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.; Nath, B.N.; Parthiban, G.; Sankar, S.J.

    organism. Sediment piled up on the sides of the disturber tracks due to its motion could be observed in areas adjacent to the tracks. The camera profiles parallel to the disturber tracks showed lumps of sediment that had been redeposited from the discharge... disturbance features noted in photographs were plotted with respect to the distance from the center of the disturbance track (Fig. 4). Most of the tracks of the disturber (87%) as well as sediment piles (91%) generated due to the disturber movement...

  4. Assessment of ecosystem resilience to hydroclimatic disturbances in India.

    Science.gov (United States)

    Sharma, Ashutosh; Goyal, Manish Kumar

    2018-02-01

    Recent studies have shown an increasing trend in hydroclimatic disturbances like droughts, which are anticipated to become more frequent and intense under global warming and climate change. Droughts adversely affect the vegetation growth and crop yield, which enhances the risks to food security for a country like India with over 1.2 billion people to feed. Here, we compared the response of terrestrial net primary productivity (NPP) to hydroclimatic disturbances in India at different scales (i.e., at river basins, land covers, and climate types) to examine the ecosystems' resilience to such adverse conditions. The ecosystem water use efficiency (WUE e : NPP/Evapotranspiration) is an effective indicator of ecosystem productivity, linking carbon (C) and water cycles. We found a significant difference (p climate policy making, and highlight the need for taking sufficient adaptation measures to ensure sustainability of ecosystems. © 2017 John Wiley & Sons Ltd.

  5. Quantum Errors and Disturbances: Response to Busch, Lahti and Werner

    Directory of Open Access Journals (Sweden)

    David Marcus Appleby

    2016-05-01

    Full Text Available Busch, Lahti and Werner (BLW have recently criticized the operator approach to the description of quantum errors and disturbances. Their criticisms are justified to the extent that the physical meaning of the operator definitions has not hitherto been adequately explained. We rectify that omission. We then examine BLW’s criticisms in the light of our analysis. We argue that, although the BLW approach favour (based on the Wasserstein two-deviation has its uses, there are important physical situations where an operator approach is preferable. We also discuss the reason why the error-disturbance relation is still giving rise to controversies almost a century after Heisenberg first stated his microscope argument. We argue that the source of the difficulties is the problem of interpretation, which is not so wholly disconnected from experimental practicalities as is sometimes supposed.

  6. Disturbance Accommodating Adaptive Control with Application to Wind Turbines

    Science.gov (United States)

    Frost, Susan

    2012-01-01

    Adaptive control techniques are well suited to applications that have unknown modeling parameters and poorly known operating conditions. Many physical systems experience external disturbances that are persistent or continually recurring. Flexible structures and systems with compliance between components often form a class of systems that fail to meet standard requirements for adaptive control. For these classes of systems, a residual mode filter can restore the ability of the adaptive controller to perform in a stable manner. New theory will be presented that enables adaptive control with accommodation of persistent disturbances using residual mode filters. After a short introduction to some of the control challenges of large utility-scale wind turbines, this theory will be applied to a high-fidelity simulation of a wind turbine.

  7. Sleep disturbances after fast-track hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Krenk, L; Jennum, P; Kehlet, H

    2012-01-01

    on the fourth postoperative night. There was no association between opioid use, pain scores, and inflammatory response with a disturbed sleep pattern. CONCLUSIONS: /st>Despite ultra-short LOS and provision of spinal anaesthesia with multimodal opioid-sparing analgesia, REM sleep was almost eliminated......BACKGROUND: /st>Major surgery is followed by pronounced sleep disturbances after traditional perioperative care potentially leading to prolonged recovery. The aim was to evaluate the rapid eye movement (REM) sleep duration and sleep architecture before and after fast-track hip and knee replacement......, and on the fourth postoperative night at home. Sleep staging was performed according to the American Academy of Sleep Medicine manual. Opioid use, pain, and inflammatory response (C-reactive protein) were also evaluated. RESULTS: /st>The mean LOS was 1.5 (1-2) days. The mean REM sleep time decreased from a mean...

  8. [Marshmallow for investigating functional disturbances of the esophageal body].

    Science.gov (United States)

    Keren, S; Argaman, E

    1992-09-01

    Manometric studies using water boluses do not always demonstrate disturbances in esophageal motility. We tested the use of a marshmallow bolus to induce abnormal manometric patterns in patients with dysphagia in whom manometric studies using water boluses were normal or nearly so. The study group included 12 normal volunteers and 22 patients with dysphagia and nearly normal manometric studies. Pressure was recorded along the esophageal body using 10 "wet" swallows followed by 10 "solid" swallows of marshmallow. In normal subjects there were fewer abnormal contractions after solid swallows than after wet swallows. In 15 patients solid swallows induced abnormal motility patterns which were not observed after wet swallows. The probability of inducing abnormal contractions in patients after solid swallows is significantly greater than after wet swallows (p < 0.0001). Solid swallowing is therefore useful in evaluating functional disturbances of the esophagus in patients with dysphagia.

  9. Increased sensitivity to climate change in disturbed ecosystems

    DEFF Research Database (Denmark)

    Kroël-Dulay, György; Ransijn, Johannes; Schmidt, Inger Kappel

    2015-01-01

    this relationship for the perturbation of climate change. Here we show that vegetation (abundance, species richness and species composition) across seven European shrublands is quite resistant to moderate experimental warming and drought, and responsiveness is associated with the dynamic state of the ecosystem......Human domination of the biosphere includes changes to disturbance regimes, which push many ecosystems towards early-successional states. Ecological theory predicts that early-successional ecosystems are more sensitive to perturbations than mature systems, but little evidence supports......, with recently disturbed sites responding to treatments. Furthermore, most of these responses are not rapid (2-5 years) but emerge over a longer term (7-14 years). These results suggest that successional state influences the sensitivity of ecosystems to climate change, and that ecosystems recovering from...

  10. A test method for analysing disturbed ethernet data streams

    Science.gov (United States)

    Kreitlow, M.; Sabath, F.; Garbe, H.

    2015-11-01

    Ethernet connections, which are widely used in many computer networks, can suffer from electromagnetic interference. Typically, a degradation of the data transmission rate can be perceived as electromagnetic disturbances lead to corruption of data frames on the network media. In this paper a software-based measuring method is presented, which allows a direct assessment of the effects on the link layer. The results can directly be linked to the physical interaction without the influence of software related effects on higher protocol layers. This gives a simple tool for a quantitative analysis of the disturbance of an Ethernet connection based on time domain data. An example is shown, how the data can be used for further investigation of mechanisms and detection of intentional electromagnetic attacks.

  11. Disturbance observer based current controller for vector controlled IM drives

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Dal, Mehmet

    2008-01-01

    In order to increase the accuracy of the current control loop, usually, well known parameter compensation and/or cross decoupling techniques are employed for advanced ac drives. In this paper, instead of using these techniques an observer-based current controller is proposed for vector controlled...... induction motor (IM) drives. The control design, based on synchronously rotating d-q frame model of the machine, has a simple structure that combines the proportional portion of a conventional PI control and output of the observer. The observer is predicted to estimate the disturbances caused by parameters...... change in current control loop and, also to remove undesired cross coupling existing between components of the stator current. The observer uses the measured stator currents and estimated PWM voltages, and produces a disturbance signal with a low pass filter. The proposed control scheme reduces cross...

  12. Stability and disturbance of large dc superconducting magnets

    International Nuclear Information System (INIS)

    Wang, S.T.

    1981-01-01

    This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet performance and the observed coil disturbances

  13. Nonlinear underwater robot controller design with adaptive disturbance prediction

    Directory of Open Access Journals (Sweden)

    Xin Songa

    2011-08-01

    Full Text Available A new hybrid adaptive control algorithm is proposed for the nonlinear system controller design of underwater robot. Compared with the previous works in the controller design of underwater robot, the main advantages of this work are: (1 A new disturbance prediction and compensation model is proposed; (2 A new adaptive fuzzy smoother is proposed for the control input; (3 A time-varying flow disturbance is considered for the control design which is always neglected in many previous works and several practical experiments under different environment were implemented to verify the control performance. The Lyapunov stability theory proves the stability and convergence of this new control system. Simulation and experiment results demonstrate the performance and the effectiveness of this new algorithm.

  14. Unique Migraine Subtypes, Rare Headache Disorders, and Other Disturbances.

    Science.gov (United States)

    Goadsby, Peter J

    2015-08-01

    The medical aphorism that common things happen commonly makes unique (and less common) migraine subtypes especially appropriate to review for the general neurologist. This article also identifies some rare headache disorders and other disturbances, and offers strategies to manage them. This article discusses migraine with brainstem aura, which is troublesome clinically and has had a change in terminology in the International Classification of Headache Disorders, Third Edition, beta version (ICHD-3 beta), and hemiplegic migraine, which is also troublesome in practice. The rare headache disorder hypnic headache and the exploding head syndrome are also discussed. When hypnic headache is recognized, it is eminently treatable, while exploding head syndrome is a benign condition with no reported consequences. Unique migraine subtypes, rare headache disorders, and other disturbances present to neurologists. When recognized, they can often be managed very well, which offers significant benefits to patients and practice satisfaction to neurologists.

  15. Body volume in ground beetles (Carabidae reflects biotope disturbance

    Directory of Open Access Journals (Sweden)

    Langraf Vladimír

    2017-12-01

    Full Text Available Changes in body size of living organisms can indicate changes in environmental quality. The family Carabidae is frequently used as an indicator of environmental status. We collected ground beetles in 9 Slovakian localities (in the Veporské vrchy Mts and the Juhoslovenská kotlina Basin of various levels of disturbance, and evaluated the volume of individuals. The lowest average body volumes of individual were found for an intensively grazed pasture (locality 5 and a nitrophilous waterside vegetation (locality 6 (1,298 mm3–4,648 mm3 with predominantly macropterous species. We have confirmed the significantly higher average biovolume value of individual Carabidae in less disturbed habitats: a Picea abies plantation (locality 1, a Carpathian oak-hornbeam forest (locality 4 and a Carpathian turkey oak forest (locality 7 (from 9,837 mm3 to 13,038 mm3, where apterous and brachypterous species dominated.

  16. Predicting Chronic Climate-Driven Disturbances and Their Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, Nate G.; Michaletz, Sean T.; Bennett, Katrina E.; Solander, Kurt C.; Xu, Chonggang; Maxwell, Reed M.; Middleton, Richard S.

    2018-01-01

    Society increasingly demands the stable provision of ecosystem resources to support our population. Resource risks from climate-driven disturbances--including drought, heat, insect outbreaks, and wildfire--are rising as a chronic state of disequilibrium results from increasing temperatures and a greater frequency of extreme events. This confluence of increased demand and risk may soon reach critical thresholds. We explain here why extreme chronic disequilibrium of ecosystem function is likely to increase dramatically across the globe, creating no-analog conditions that challenge adaptation. We also present novel mechanistic theory that combines models for disturbance mortality and metabolic scaling to link size-dependent plant mortality to changes in ecosystem stocks and fluxes. Efforts must anticipate and model chronic ecosystem disequilibrium to properly prepare for resilience planning.

  17. Disturbed sense of identity in borderline personality disorder.

    Science.gov (United States)

    Jørgensen, Carsten René

    2006-12-01

    Traditionally, personal identity is considered to be important for psychological health and adaptive functioning. Identity diffusion and other more severe forms of disturbance associated with personal identity are regarded as being essential parts of the borderline personality disorder. Moreover, disturbances in identity are seen as being part of the dynamic background for many of the symptoms and maladaptive behaviors found in borderline patients. It is argued, that the development of personal identity is intimately related to, and indeed dependent on, elements of modern culture, with significant cultural changes having affected the conditions under which human identity develops. Therefore, the identity diffusion seen in patients with borderline disorders must be understood in relation to not only the individual patient's personal history and inner structures but also contemporary late modern culture and social organization.

  18. Enhancement factors for resuspended aerosol radioactivity: Effects of topsoil disturbance

    International Nuclear Information System (INIS)

    Shinn, J.H.

    1991-11-01

    The enhancement factor for airborne radionuclides resuspended by wind is defined as the ratio of the activity density (Bq g -1 ) in the aerosol to the activity density in the underlying surface of contaminated soil. Enhancement factors are useful for assessment of worst-case exposure scenarios and transport conditions, and are one of the criteria for setting environmental standards for radioactivity in soil. This paper presents results of experimental studies where resuspension of 239 Pu was measured when air concentrations were equilibrated to the soil surface. Enhancement factors were observed for several types of man-made disturbances (bulldozer-blading, soil raking, vacuum-cleaning) and natural disturbances (springtime thaw, soil-drying, wildfire). For some cases, enhancement factors are compared over range of geographical locations (Bikini Atoll, California, Nevada, and South Carolina). The particle-size distributions of aerosol activity are compared to particle-size distributions of the underlying soil

  19. Disturbance-mediated accelerated succession in two Michigan forest types

    Science.gov (United States)

    Abrams, Marc D.; Scott, Michael L.

    1989-01-01

    In northern lower Michigan, logging accelerated sugar maple (Acer saccharum) dominance in a northern white cedar (Thuja occidentals) community, and clear-cutting and burning quickly converted certain sites dominated by mature jack pine (Pinus banksiana) to early-succesional hardwoods, including Prunus, Populus, and Quercus. In both forest types the succeeding hardwoods should continue to increase in the future at the expense of the pioneer conifer species. In the cedar example, sugar maple was also increasing a an undisturbed, old-growth stand, but at a much reduced rate than in the logged stand. Traditionally, disturbance was through to set back succession to some earlier stage. However, out study sites and at least several other North American forest communities exhibited accelerated succession following a wide range of disturbances, including logging fire, ice storms, wind-throw, disease, insect attack, and herbicide spraying.

  20. Atmospheric disturbance model for aircraft and space capable vehicles

    Science.gov (United States)

    Chimene, Beau C.; Park, Young W.; Bielski, W. P.; Shaughnessy, John D.; Mcminn, John D.

    1992-01-01

    An atmospheric disturbance model (ADM) is developed that considers the requirements of advanced aerospace vehicles and balances algorithmic assumptions with computational constraints. The requirements for an ADM include a realistic power spectrum, inhomogeneity, and the cross-correlation of atmospheric effects. The baseline models examined include the Global Reference Atmospheric Model Perturbation-Modeling Technique, the Dryden Small-Scale Turbulence Description, and the Patchiness Model. The Program to Enhance Random Turbulence (PERT) is developed based on the previous models but includes a revised formulation of large-scale atmospheric disturbance, an inhomogeneous Dryden filter, turbulence statistics, and the cross-correlation between Dryden Turbulence Filters and small-scale thermodynamics. Verification with the Monte Carlo approach demonstrates that the PERT software provides effective simulations of inhomogeneous atmospheric parameters.

  1. Effects of Disturbance on Populations of Marine Mammals

    Science.gov (United States)

    2015-09-30

    interactions between bottlenose dolphins and boats in the Moray Firth. In this case, data were collected during scan-samples of focal groups of...potential responses of species to environmental changes and diverse human activities. OBJECTIVES Translate conceptual models of effects of disturbance...expenses for the greatest proportion of participants and maximized opportunities to interact with other parties interested in the work and its

  2. Active disturbance rejection control: methodology and theoretical analysis.

    Science.gov (United States)

    Huang, Yi; Xue, Wenchao

    2014-07-01

    The methodology of ADRC and the progress of its theoretical analysis are reviewed in the paper. Several breakthroughs for control of nonlinear uncertain systems, made possible by ADRC, are discussed. The key in employing ADRC, which is to accurately determine the "total disturbance" that affects the output of the system, is illuminated. The latest results in theoretical analysis of the ADRC-based control systems are introduced. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Disturbance-mediated facilitation by an intertidal ecosystem engineer.

    Science.gov (United States)

    Wright, Jeffrey T; Gribben, Paul E

    2017-09-01

    Ecosystem engineers facilitate communities by providing a structural habitat that reduces abiotic stress or predation pressure for associated species. However, disturbance may damage or move the engineer to a more stressful environment, possibly increasing the importance of facilitation for associated communities. In this study, we determined how disturbance to intertidal boulders (i.e., flipping) and the subsequent movement of a structural ecosystem engineer, the tube-forming serpulid worm Galeolaria caespitosa, from the bottom (natural state, low abiotic stress) to the top (disturbed state, high abiotic stress) surface of boulders influenced the importance of facilitation for intertidal communities across two intertidal zones. Theory predicts stronger relative facilitation should occur in the harsher environments of the top of boulders and the high intertidal zone. To test this prediction, we experimentally positioned boulders with the serpulids either face up or face down for 12 months in low and high zones in an intertidal boulder field. There were very different communities associated with the different boulders and serpulids had the strongest facilitative effects on the more stressful top surface of boulders with approximately double the species richness compared to boulders lacking serpulids. Moreover, within the serpulid matrix itself there was also approximately double the species richness (both zones) and abundance (high zone only) of small invertebrates on the top of boulders compared to the bottom. The high relative facilitation on the top of boulders reflected a large reduction in temperature by the serpulid matrix on that surface (up to 10°C) highlighting a key role for modification of the abiotic environment in determining the community-wide facilitation. This study has demonstrated that disturbance and subsequent movement of an ecosystem engineer to a more stressful environment increased the importance of facilitation and allowed species to

  4. Soil and biomass carbon re-accumulation after landslide disturbances

    Science.gov (United States)

    Schomakers, Jasmin; Jien, Shih-Hao; Lee, Tsung-Yu; Huang-Chuan, Jr.; Hseu, Zeng-Yei; Lin, Zan Liang; Lee, Li-Chin; Hein, Thomas; Mentler, Axel; Zehetner, Franz

    2017-07-01

    In high-standing islands of the Western Pacific, typhoon-triggered landslides occasionally strip parts of the landscape of its vegetative cover and soil layer and export large amounts of biomass and soil organic carbon (OC) from land to the ocean. After such disturbances, new vegetation colonizes the landslide scars and OC starts to re-accumulate. In the subtropical mountains of Taiwan and in other parts of the world, bamboo (Bambusoideae) species may invade at a certain point in the succession of recovering landslide scars. Bamboo has a high potential for carbon sequestration because of its fast growth and dense rooting system. However, it is still largely unknown how these properties translate into soil OC re-accumulation rates after landslide disturbance. In this study, a chronosequence was established on four former landslide scars in the Central Mountain Range of Taiwan, ranging in age from 6 to 41 years post disturbance as determined by landslide mapping from remote sensing. The younger landslide scars were colonized by Miscanthus floridulus, while after approx. 15 to 20 years of succession, bamboo species (Phyllostachys) were dominating. Biomass and soil OC stocks were measured on the recovering landslide scars and compared to an undisturbed Cryptomeria japonica forest stand in the area. After initially slow re-vegetation, biomass carbon accumulated in Miscanthus stands with mean annual accretion rates of 2 ± 0.5 Mg C ha- 1 yr- 1. Biomass carbon continued to increase after bamboo invasion and reached 40% of that in the reference forest site after 41 years of landslide recovery. Soil OC accumulation rates were 2.0 Mg C ha- 1 yr- 1, 6 to 41 years post disturbance reaching 64% of the level in the reference forest. Our results from this in-situ study suggest that recovering landslide scars are strong carbon sinks once an initial lag period of vegetation re-establishment is overcome.

  5. Regenerative role of seed banks following an intense soil disturbance

    Science.gov (United States)

    Luzuriaga, Arantzazu L.; Escudero, Adrián; Olano, José Miguel; Loidi, Javier

    2005-02-01

    Our main aim was to determine the contribution of the seed bank to vegetation regeneration following a disturbance consisting in a deep ploughing and a thorough homogenisation of a perennial grassland. In the seed bank prior to disturbance, seed distribution through the vertical soil profile was evaluated to determine the initial seed species structure. Then, several characteristics of the shallow seed bank and the extant vegetation were evaluated prior and following field disturbance: seed species composition and abundance, and species composition of the aboveground vegetation. The contribution of seed rain versus seed bank was evaluated by means of the comparison of the vegetation developed in plots filled with sterilised soil (seed bank removal) and the vegetation developed in non-sterilised plots in the field. The distribution of seeds through the profile indicated a sharp decline in abundance with depth, and it was probably linked to propagule morphology, with small and rounded seeds proner to being buried deeper than larger seeds. In the grassland prior to disturbance, the aboveground vegetation and seed bank species composition showed very low similarity index, most likely because during the 5 years following field abandonment, sheep pressure had caused a faster change in aboveground vegetation species composition than in seed bank species composition. Ploughing and homogenisation of the grassland led to low seed abundance in the shallow soil layer caused by dilution of the seed bank. Regardless of impoverishment in seed abundance and species richness, comparison between sterilised and non-sterilised plots showed that the seed bank acted as an effective source of colonising species and determined the aboveground species composition. To summarise, this study outlines the importance of considering several characteristics of the seed bank, such as species composition and seed abundance, in the understanding of the function of seed bank and dynamics of the

  6. Restless Legs Syndrome and Sleep-Wake Disturbances in Pregnancy

    Science.gov (United States)

    Dunietz, Galit Levi; Lisabeth, Lynda D.; Shedden, Kerby; Shamim-Uzzaman, Q. Afifa; Bullough, Alexandra S.; Chames, Mark C.; Bowden, Marc F.; O'Brien, Louise M.

    2017-01-01

    Study Objectives: To estimate the association of restless legs syndrome (RLS) and its frequency with sleep-wake disturbances in pregnancy. Methods: A cohort of 1,563 women in their third trimester of pregnancy were recruited from prenatal clinics between March 2007 and December 2010. Demographic, pregnancy, and delivery data were extracted from medical records and sleep information was collected with questionnaires. To diagnose RLS, we used standardized criteria of RLS symptoms and frequency that were developed by the International Restless Legs Study Group. Logistic regression models were constructed to investigate the association of RLS and its frequency with sleep-wake disturbances (poor sleep quality, daytime sleepiness, poor daytime function) and delivery outcomes. Results: Overall 36% of the pregnant women had RLS, and half had moderate to severe symptoms. Compared to women without RLS, those with RLS were more likely to have poor sleep quality (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.7–2.9), poor daytime function (OR 1.9, 95% CI 1.4–2.4), and excessive daytime sleepiness (OR 1.6, 95% CI 1.3–2.0). A dose-response relationship also was evident between RLS frequency and each of the sleep-wake disturbances. There was no evidence for any association between RLS and delivery outcomes. Conclusions: RLS is a significant contributor to poor sleep quality, daytime sleepiness, and poor daytime function, all common and often debilitating conditions in pregnancy. Obstetric health care providers should be aware of these associations and screen women for RLS. Commentary: A commentary on this article appears in this issue on page 857. Citation: Dunietz GL, Lisabeth LD, Shedden K, Shamim-Uzzaman A, Bullough AS, Chames MC, Bowden MF, O'Brien LM. Restless legs syndrome and sleep-wake disturbances in pregnancy. J Clin Sleep Med. 2017;13(7):863–870. PMID:28633715

  7. After the Fall: The Tapestry of Disturbance and Recovery.

    Science.gov (United States)

    Nadkarni, Nalini M

    2017-02-01

    On July 3, 2015, Nalini Nadkarni, a world-renowned ecologist who had been studying the biologic processes of ecosystem disturbance and recovery, sustained a catastrophic 50-foot free-fall from the top of the rainforest canopy to the forest floor at her remote field research site. She lost consciousness in shock and sustained life-threatening injuries. Her accompanying students hiked out, radio-called 911, and the Harborview Medical Center (Seattle) Medivac team arrived 4 hours later to rescue her. Her prognosis was extremely grim; her family gathered in anticipation of her death as she underwent four operations during her 10 days in the ICU. As she emerged from coma, she spent weeks of hospital recovery and months of progressive mobility and physical therapy during medical leave from work. She experienced ICU psychosis and postintensive care syndrome, but slowly recovered nearly totally, to the point where she can solo hike up to 18 miles in a day, and has fully resumed her professional responsibilities as professor of biology, including climbing tall trees for her canopy research. She attributes her survival and remarkable recovery to both exquisite medical critical care and support she received, and also to incorporating lessons learned from her interdisciplinary study of how diverse natural systems commonly experience and recover from catastrophic disturbances (e.g., forest fires, traffic jams, orphaned children, and refugee survivors of war). Insights from her own encounter with critical illness and study of disturbance and recovery led her to reflect on the tapestry of disturbance and recovery that permeate all ecosystems, and with relevance to the evolving Society of Critical Care Medicine, postintensive care syndrome, and THRIVE initiatives.

  8. Characterizing sleeping habits and disturbances among Saudi adults

    OpenAIRE

    Al-Tannir, Mohamad A.; Kobrosly, Samer Y.; Al-Badr, Ahmad H.; Salloum, Nourhan A.; Altannir, Youssef M.; Sakkijha, Husam M.

    2016-01-01

    Objectives To characterize sleeping habits, assess sleep disturbance prevalence, and identify associated factors among Saudi adults. Methods A total of 1720 adults were approached for this observational cross-sectional study between October 2014 and March 2015. The study took place in Riyadh, the capital of Saudi Arabia. We used a questionnaire to describe sleeping characteristics in relation to existing chronic diseases, smoking status, obesity, daily performance and sociodemographic variabl...

  9. Sandhill crane roost selection, human disturbance, and forage resources

    Science.gov (United States)

    Pearse, Aaron T.; Krapu, Gary; Brandt, David

    2017-01-01

    Sites used for roosting represent a key habitat requirement for many species of birds because availability and quality of roost sites can influence individual fitness. Birds select roost sites based on numerous factors, requirements, and motivations, and selection of roosts can be dynamic in time and space because of various ecological and environmental influences. For sandhill cranes (Antigone canadensis) at their main spring-staging area along the Platte River in south-central Nebraska, USA, past investigations of roosting cranes focused on physical channel characteristics related to perceived security as motivating roost distribution. We used 6,310 roost sites selected by 313 sandhill cranes over 5 spring migration seasons (2003–2007) to quantify resource selection functions of roost sites on the central Platte River using a discrete choice analysis. Sandhill cranes generally showed stronger selection for wider channels with shorter bank vegetation situated farther from potential human disturbance features such as roads, bridges, and dwellings. Furthermore, selection for roost sites with preferable physical characteristics (wide channels with short bank vegetation) was more resilient to nearby disturbance features than more narrow channels with taller bank vegetation. The amount of cornfields surrounding sandhill crane roost sites positively influenced relative probability of use but only for more narrow channels resource features that sandhill cranes selected at river channels along the Platte River, and after incorporating spatial variation due to human disturbance, our understanding of roost site selection was more robust, providing insights on how disturbance may interact with physical habitat features. Managers can use information on roost-site selection when developing plans to increase probability of crane use at existing roost sites and to identify new areas for potential use if existing sites become limited.

  10. Fluid and Electrolyte Disturbances in Critically Ill Patients

    OpenAIRE

    Lee, Jay Wook

    2010-01-01

    Disturbances in fluid and electrolytes are among the most common clinical problems encountered in the intensive care unit (ICU). Recent studies have reported that fluid and electrolyte imbalances are associated with increased morbidity and mortality among critically ill patients. To provide optimal care, health care providers should be familiar with the principles and practice of fluid and electrolyte physiology and pathophysiology. Fluid resuscitation should be aimed at restoration of normal...

  11. Disturbance decouples biogeochemical cycles across forests of the southeastern US

    Science.gov (United States)

    Ashley D. Keiser; Jennifer D. Knoepp; Mark A. Bradford

    2016-01-01

    Biogeochemical cycles are inherently linked through the stoichiometric demands of the organisms that cycle the elements. Landscape disturbance can alter element availability and thus the rates of biogeochemical cycling. Nitrification is a fundamental biogeochemical process positively related to plant productivity and nitrogen loss from soils to aquatic systems, and the...

  12. The functional anatomy of psychomotor disturbances in major depressive disorder

    Directory of Open Access Journals (Sweden)

    Benny eLiberg

    2015-03-01

    Full Text Available Psychomotor disturbances (PMD are a classic feature of depressive disorder that provide rich clinical information. The aim our narrative review was to characterize the functional anatomy of PMD by summarizing findings from neuroimaging studies. We found evidence across several neuroimaging modalities that suggest involvement of fronto-striatal neurocircuitry, and monoaminergic pathways and metabolism. We suggest that PMD in major depressive disorder emerge from an alteration of limbic signals, which influence emotion, volition, higher-order cognitive functions, and movement.

  13. Dissipative Control Systems and Disturbance Attenuation for Nonlinear H∞ Problems

    International Nuclear Information System (INIS)

    Frankowska, H.; Quincampoix, M.

    1999-01-01

    We characterize functions satisfying a dissipative inequality associated with a control problem. Such a characterization is provided in terms of an epicontingent solution, or a viscosity supersolution to a partial differential equation called Isaacs' equation. Links between supersolutions and epicontingent solutions to Isaacs' equation are studied. Finally, we derive (possibly discontinuous) disturbance attenuation feedback of the H ∞ problem from contingent formulation of Isaacs' equation

  14. Speckle perception and disturbance limit in laser based projectors

    Science.gov (United States)

    Verschaffelt, Guy; Roelandt, Stijn; Meuret, Youri; Van den Broeck, Wendy; Kilpi, Katriina; Lievens, Bram; Jacobs, An; Janssens, Peter; Thienpont, Hugo

    2016-04-01

    We investigate the level of speckle that can be tolerated in a laser cinema projector. For this purpose, we equipped a movie theatre room with a prototype laser projector. A group of 186 participants was gathered to evaluate the speckle perception of several, short movie trailers in a subjective `Quality of Experience' experiment. This study is important as the introduction of lasers in projection systems has been hampered by the presence of speckle in projected images. We identify a speckle disturbance threshold by statistically analyzing the observers' responses for different values of the amount of speckle, which was monitored using a well-defined speckle measurement method. The analysis shows that the speckle perception of a human observer is not only dependent on the objectively measured amount of speckle, but it is also strongly influenced by the image content. As is also discussed in [Verschaffelt et al., Scientific Reports 5, art. nr. 14105, 2015] we find that, for moving images, the speckle becomes disturbing if the speckle contrast becomes larger than 6.9% for the red, 6.0% for the green, and 4.8% for the blue primary colors of the projector, whereas for still images the speckle detection threshold is about 3%. As we could not independently tune the speckle contrast of each of the primary colors, this speckle disturbance limit seems to be determined by the 6.9% speckle contrast of the red color as this primary color contains the largest amount of speckle. The speckle disturbance limit for movies thus turns out to be substantially larger than that for still images, and hence is easier to attain.

  15. Anthropogenic disturbances jeopardize biodiversity conservation within tropical rainforest reserves.

    Science.gov (United States)

    Martínez-Ramos, Miguel; Ortiz-Rodríguez, Iván A; Piñero, Daniel; Dirzo, Rodolfo; Sarukhán, José

    2016-05-10

    Anthropogenic disturbances affecting tropical forest reserves have been documented, but their ecological long-term cumulative effects are poorly understood. Habitat fragmentation and defaunation are two major anthropogenic threats to the integrity of tropical reserves. Based on a long-term (four decades) study, we document how these disturbances synergistically disrupt ecological processes and imperil biodiversity conservation and ecosystem functioning at Los Tuxtlas, the northernmost tropical rainforest reserve in the Americas. Deforestation around this reserve has reduced the reserve to a medium-sized fragment (640 ha), leading to an increased frequency of canopy-gap formation. In addition, hunting and habitat loss have caused the decline or local extinction of medium and large herbivores. Combining empirical, experimental, and modeling approaches, we support the hypothesis that such disturbances produced a demographic explosion of the long-lived (≈120 y old, maximum height of 7 m) understory palm Astrocaryum mexicanum, whose population has increased from 1,243-4,058 adult individuals per hectare in only 39 y (annual growth rate of ca 3%). Faster gap formation increased understory light availability, enhancing seed production and the growth of immature palms, whereas release from mammalian herbivory and trampling increased survival of seedlings and juveniles. In turn, the palm's demographic explosion was followed by a reduction of tree species diversity, changing forest composition, altering the relative contribution of trees to forest biomass, and disrupting litterfall dynamics. We highlight how indirect anthropogenic disturbances (e.g., palm proliferation) on otherwise protected areas threaten tropical conservation, a phenomenon that is currently eroding the planet's richest repositories of biodiversity.

  16. Far-field coseismic ionospheric disturbances of Tohoku earthquake

    Czech Academy of Sciences Publication Activity Database

    Krasnov, V. M.; Drobzheva, Ya. V.; Chum, Jaroslav

    2015-01-01

    Roč. 135, December (2015), s. 12-21 ISSN 1364-6826 R&D Projects: GA ČR(CZ) GC15-07281J Institutional support: RVO:68378289 Keywords : earthquake * infrasonic waves * ionospheric disturbances * infrasound triggered by the earthquake * co-seismic ionospheric perturbations * modeling * remote sensing Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.463, year: 2015 http://www.sciencedirect.com/science/article/pii/S1364682615300584

  17. Impact of sleep disturbances in inflammatory bowel disease.

    Science.gov (United States)

    Ranjbaran, Ziba; Keefer, Laurie; Farhadi, Ashkan; Stepanski, Edward; Sedghi, Shahriar; Keshavarzian, Ali

    2007-11-01

    Normal sleep is paramount for a healthy lifestyle and high quality of life. Sleep modulates the immune system and thus affects the course of several chronic inflammatory conditions. There are no reported studies that address the role of sleep disturbance in the course of inflammatory bowel disease (IBD). The aim of this study was to characterize sleep disturbance in IBD using validated measures of sleep and quality of life. A self-administered, mail-in questionnaire package was sent to 205 subjects after a brief instruction. The questionnaire package was composed of the Pittsburgh Sleep Quality Index (PSQI), a measure of disease severity and the IBD-Quality of Life Questionnaire. A total of 119 subjects were recruited (58% response rate): 80 with inactive IBD, 24 with irritable bowel syndrome (IBS) and 15 healthy controls. The IBD subjects reported significantly prolonged sleep latency, frequent sleep fragmentation, higher rate of using sleeping pills, decreased day-time energy, increased tiredness and poor overall sleep quality compared to healthy controls. The abnormal sleep patterns in IBD subjects were similar to IBS subjects. The reported sleep quality was correlated with IBD disease severity score (r(2) = 0.55, P = 0.02). Both IBD and IBS subjects thought that sleep and their disease status were correlated. The results show that IBD patients have significant sleep disturbance even when their disease is not active. This problem might affect quality of life, gastrointestinal symptoms and coping ability, and might potentially modify disease severity or increase risk of flare-up. Regardless of the primary or secondary origin of this problem, sleep disturbance should be addressed in the clinical management of patients with IBD.

  18. ADAPTIVE CONTROL ALGORITHM WITH GIVEN ACCURACY UNDER UNKNOWN EXTERNAL DISTURBANCES

    OpenAIRE

    Збруцкий, Александр Васильевич; Мищук, Анастасия С.

    2014-01-01

    Typical tasks that UAVs deal with are aerial patrols, monitoring, landscape photos and others, and flight parameters are required to be kept guaranteed with the desired accuracy. At the same time UAVs are flying on low altitudes in the turbulent atmosphere. The external disturbance perceived on UAV cannot be determined with sufficient accuracy. Therefore, the creation of Automatic Control System (ACS) to provide the desired accuracy keeping flight parameters in the face of uncertain external ...

  19. Sleep Disturbances and their Relationship to Cardiovascular Disease

    OpenAIRE

    Quan, Stuart F.

    2009-01-01

    Sleep disturbances are a common problem with chronic insomnia occurring in 10% of the general adult population and obstructive sleep apnea present in 4% and 2% of middle-aged men and women respectively. In addition, Americans are sleeping fewer hours per night than they did 20 years ago. There is now increasing evidence that reductions and increases in sleep duration, and various sleep disorders including obstructive sleep apnea and insomnia may be causal factors in the development of cardiov...

  20. Alexia for arithmetical signs. A cause of disturbed calculation.

    Science.gov (United States)

    Ferro, J M; Silveira Botelho, M A

    1980-03-01

    Asymbolic acalculia is a variety of acalculia characterized by a failure to differentiate the arithmetical symbols. Two patients presenting this disturbance as the only source of their calculating errors are reported. Neither aphasia nor visuo-verbal disconnection could explain the failure to identify the arithmetical signs. This defect is interpreted as an alexia for this particular semiotic system, the arithmetical signs being stripped of their names and of the corresponding computational rules.