WorldWideScience

Sample records for delayed clutch initiation

  1. Melatonin delays clutch initiation in a wild songbird

    Science.gov (United States)

    Greives, Timothy J.; Kingma, Sjouke A.; Beltrami, Giulia; Hau, Michaela

    2012-01-01

    The hormone melatonin is known to play an important role in regulating many seasonal changes in physiology, morphology and behaviour. In birds, unlike in mammals, melatonin has thus far been thought to play little role in timing seasonal reproductive processes. This view is mainly derived from laboratory experiments on male birds. This study tests whether melatonin is capable of influencing the timing of clutch initiation in wild female songbirds. Free-living female great tits (Parus major) treated with melatonin-filled implants prior to the breeding season initiated their first clutch of the season significantly later than females carrying an empty implant. Melatonin treatment did not affect clutch size. Further, melatonin treatment did not delay the onset of daily activity in the wild nor adversely affect body mass in captivity compared with controls. These data suggest a previously unknown role for this hormone in regulating the timing of clutch initiation in the wild. PMID:22171024

  2. Circulating carotenoid concentrations are positively correlated with later clutch initiation in Florida Scrub-Jays (Aphelocoma coerulescens).

    Science.gov (United States)

    Heiss, Rebecca S; Cohen, Alan A; Bowman, Reed; Boughton, Raoul K; Bridge, Eli; McGraw, Kevin J; Schoech, Stephan J

    2011-02-01

    Antioxidants play key roles in preventing free radical damage to various molecules, cells, and tissues, but it is not well understood how variation in antioxidant levels may relate to the reproductive success or health of wild animals. We explored the relationship between circulating antioxidant concentrations and both body condition and timing of reproduction in male and female Florida Scrub-Jays (Aphelocoma coerulescens), a cooperatively breeding passerine bird. We examined whether levels of uric acid, vitamin E, and carotenoids (all potentially important antioxidants) were linked to body condition and timing of reproduction, two measures that are directly related to reproductive success. Antioxidant concentrations were not correlated with body condition, but they were related to timing of first clutch initiation, though not always in the predicted direction. Elevated circulating levels of carotenoids were associated with delayed clutch initiation in female breeders. Relatively higher vitamin E levels in control birds were associated with earlier clutch initiation, whereas male breeders that received long-term food supplementation had elevated levels of vitamin E and delayed reproduction. Several potential explanations for the link between elevated levels of antioxidants and delayed clutch initiation are discussed. Separate explanations for each sex include, but are not limited to, oxidative stress as a result of territory defense efforts in males, different dietary regimes due to supplementation, and mobilized plasma antioxidants in females that were coping with a stressor. © 2010 Wiley-Liss, Inc.

  3. Unidirectional clutches

    International Nuclear Information System (INIS)

    1981-01-01

    Unidirectional clutches are used in nuclear power plants to protect coolant pumps and associated drive motors against reverse rotation, and as a standby system for coolant pumps. As long life is important the sprag elements should be of a high carbon alloy steel with chromium diffused into the surface for high resistance to corrosion and abrasion. The invention described is of a unidirectional clutch including inner and outer races which can be mechanically coupled together by the action of a plurality of tiltable sprag elements which increases in overall efficiency as they are tilted or rocked in a given direction. To absorb momentary excessive torque the sprag elements have camming surfaces at opposite ends, at least one of which includes an arcuate portion centred on a point lying outside the profile of the sprag element. The extreme limit of the radius of this arcuate portion is the radius of the inner surface of the outer race. The clutch can absorb high torque yet is compact. If an excessive torque is applied it will momentarily release to allow relative movement of the two races so avoiding permanent damage to the clutch. (U.K.)

  4. FEATURES OF CONTROLLING ELECTROPNEUMATIC VALVES OF ACTUATOR TO CONTROL ITS CLUTCH WITH ACCELERATION VALVE

    Directory of Open Access Journals (Sweden)

    O. A. Yaryta

    2018-01-01

    Full Text Available The article deals with one of the ways to control an actuator of the automated clutch control system. The aim is to design control of the electropneumatic actuator, to control its coupling with the acceleration valve on the basis of experimental research as well as to provide rational parameters of the automated clutch control system for the robotic transmission. The feature of the system is an acceleration valve in the design of the electropneumatic actuator to control the clutch. New links demand to adjust the way to control the actuator. The connection of Pulse-Width Modulation (PWM with single power supply pulses to control electropneumatic valves is substantiated. The quantitative characteristics of single control pulses and PWM ones are determined. The error of operation accuracy for various ways of the control of the electropneumatic actuator to control the clutch of the robotic transmission is determined. Obtained separate PWM area is designed to suppress the initial hysteresis when the rod of the clutch actuator is moved. An algorithm for the operation of a clutch control system is proposed, taking into account the use of two modes of operation of solenoid valves. A graphical interpretation of the clutch control algorithm is presented, which gives an idea of the location of the constant signal feeding zones to the solenoid valve, as well as the operation areas of the solenoid valve in PWM mode. The control algorithm of the clutch booster provides a mode of guaranteed absence of excess pressure in the pneumatic cylinder after releasing the clutch pedal, provided that two normally closed solenoid valves are used. This configuration of the electro-pneumatic clutch control system allows the use of an emergency clutch release system in case of voltage absence. The reference algorithm for filtering the array of data coming from the feedback sensor, as well as the numerical values of the delay caused by the presence of a filter, are given.

  5. Carry-over effects of winter location contribute to variation in timing of nest initiation and clutch size in black brant (Branta bernicla nigricans)

    Science.gov (United States)

    Schamber, Jason L.; Sedinger, James S.; Ward, David H.

    2012-01-01

    We assessed carry-over effects from winter location on timing of nest initiation and clutch size of Black Brant (Branta bernicla nigricans) using observations of individually marked brant breeding at the Tutakoke River colony in Alaska, and wintering along a latitudinal gradient at three areas on the Pacific coast of Baja California: northernmost Bahia San Quintin (BSQ), Laguna Ojo de Liebre (LOL), and southernmost Laguna San Ignacio (LSI). Black Brant initiated nests according to a north—south trend in winter location, although year was a stronger predictor of initiation date than was wintering site. Female Black Brant that wintered at BSQ initiated nests 2.2 days earlier than females from LSI. Conversely, Black Brant showed only a weak south—north trend in clutch size; individuals from LSI laid slightly larger clutches than individuals from BSQ, probably because a smaller proportion of only high-quality females from the southernmost wintering area in Baja California were able to attain the nutritional condition necessary to breed. These results indicate that winter location can influence individual reproductive performance and, potentially, limit population growth of southern segments of the wintering Black Brant population.

  6. Method and apparatus for executing an asynchronous clutch-to-clutch shift in a hybrid transmission

    Science.gov (United States)

    Demirovic, Besim; Gupta, Pinaki; Kaminsky, Lawrence A.; Naqvi, Ali K.; Heap, Anthony H.; Sah, Jy-Jen F.

    2014-08-12

    A hybrid transmission includes first and second electric machines. A method for operating the hybrid transmission in response to a command to execute a shift from an initial continuously variable mode to a target continuously variable mode includes increasing torque of an oncoming clutch associated with operating in the target continuously variable mode and correspondingly decreasing a torque of an off-going clutch associated with operating in the initial continuously variable mode. Upon deactivation of the off-going clutch, torque outputs of the first and second electric machines and the torque of the oncoming clutch are controlled to synchronize the oncoming clutch. Upon synchronization of the oncoming clutch, the torque for the oncoming clutch is increased and the transmission is operated in the target continuously variable mode.

  7. Electromagnetic clutches and couplings

    CERN Document Server

    Vorob'Yeva, T M; Fry, D W; Higinbotham, W

    2013-01-01

    Electromagnetic Clutches and Couplings contains a detailed description of U.S.S.R. electromagnetic friction clutches, magnetic couplings, and magnetic particle couplings. This book is divided into four chapters. The first chapter discusses the design and construction of magnetic (solenoid-operated) couplings, which are very quick-acting devices and used in low power high-speed servo-systems. Chapter 2 describes the possible fields of application, design, construction, and utilization of magnetic particle couplings. The aspects of construction, design, and utilization of induction clutches (sli

  8. Virtual Clutch Controller for Clutch-to-Clutch Shifts in Planetary-Type Automatic Transmission

    Directory of Open Access Journals (Sweden)

    Yunjiang Cheng

    2015-01-01

    Full Text Available It is known that the shift processes of the four types of clutch-to-clutch shifts can theoretically be divided into two phases which are torque phase and inertia phase, but the execution orders are different. Two virtual clutch controllers are designed with the same eight states which include all control processes for these shifts. An equivalent method is proposed so that AT can be controlled just like DCT by adopting the torque ratios of oncoming clutch and offgoing clutch of each gear. The powertrain system model and the shift controller are established on Matlab/Simulink platform. The clutch-to-clutch shift processes have been studied based on the virtual clutch controller by software-in-the-loop simulations. Some typical problems in the clutch-to-clutch shift control are discussed and several control methods are compared to solve these problems.

  9. Elevational gradient in clutch size of Red-faced Warblers

    Science.gov (United States)

    Dillon, Kristen G.; Conway, Courtney J.

    2015-01-01

    Our understanding of life history evolution has benefited from debates regarding the underlying causes, and geographic ubiquity, of spatial patterns in avian clutch sizes. Past studies have revealed that birds lay smaller clutch sizes at higher elevation. However, in most previous studies, investigators have failed to adequately control for elevational differences in breeding phenology. To better understand the elevational gradient in avian clutch size, we need to know how clutch size changes across the entire elevational breeding range of a species (i.e., the shape of the relationship between elevation and clutch size), and whether the elevational gradient in clutch size is merely an artifact of elevational gradients in breeding phenology or breeding season length. We examined the relationship between breeding elevation and clutch size of Red-faced Warblers (Cardellina rubrifrons) along a 1000-m elevational gradient in Arizona. Our objectives were to determine how clutch size changed with elevation, and if the relationship between clutch size and elevation merely reflected elevational changes in breeding season length or phenology. The proportion of 5-egg clutches decreased and the proportion of 3- and 4-egg clutches increased non-linearly with increasing elevation, even after controlling for the elevational gradient in nest initiation date. Thus, average clutch size declined across the elevational breeding range of Red-faced Warblers, but this decline was not due to elevational variation in breeding phenology. Timing of breeding changed, but the duration of the breeding season did not change appreciably across the elevational gradient. Hence, elevational differences in breeding season length or breeding phenology cannot explain why Red-faced Warblers (and perhaps other birds) breeding at higher elevations have smaller clutches.

  10. Magnitude and factors associated with delayed initiation of ...

    African Journals Online (AJOL)

    Results: In this study, 31.4% mothers delayed initiation of breastfeeding. This was associated with .... occupation, lack of prenatal guidance on advantages of breast feeding, failure to .... shown earlier in increasing uptake of exclusive breast-.

  11. Delays in initiation of acyclovir therapy in herpes simplex encephalitis.

    Science.gov (United States)

    Hughes, Peter S; Jackson, Alan C

    2012-09-01

    Diagnosis of herpes simplex encephalitis (HSE) is based on clinical findings, MRI, and detection of herpes simplex virus (HSV) DNA in cerebrospinal fluid (CSF) using polymerase chain reaction amplification. Delays in starting treatment are associated with poorer clinical outcomes. We assessed the timing of initiation of acyclovir therapy in HSE. Inpatient databases from seven hospitals in Winnipeg, Manitoba were used to identify individuals diagnosed with encephalitis and HSE from 2004 to 2009. The time taken to initiate therapy with acyclovir and the reasons for delays were determined. Seventy-seven patients were identified; 69 (90%) received acyclovir; in the others a non-HSV infection was strongly suspected. Thirteen patients were subsequently confirmed to have HSE. Acyclovir was initiated a median of 21 hours (3-407) after presentation in encephalitis cases, and a median of 11 hours (3-118) in HSE. The most common reason for delay was a failure to consider HSE in the differential diagnosis, despite suggestive clinical features. Where therapy was delayed in HSE patients, the decision to begin acyclovir was prompted by transfer of the patient to a different service (55%), recommendations by consultants (18%), imaging results (18%), and CSF pleocytosis (9%). Delays in initiating acyclovir for HSE are common, and are most often due to a failure to consider HSE in a timely fashion on presentation. In order to improve patient outcomes, physicians should be more vigilant for HSE, and begin acyclovir therapy expeditiously on the basis of clinical suspicion rather than waiting for confirmatory tests.

  12. Road deicing salt irreversibly disrupts osmoregulation of salamander egg clutches

    International Nuclear Information System (INIS)

    Karraker, Nancy E.; Gibbs, James P.

    2011-01-01

    It has been postulated that road deicing salts are sufficiently diluted by spring rains to ameliorate any physiological impacts to amphibians breeding in wetlands near roads. We tested this conjecture by exposing clutches of the spotted salamander (Ambystoma maculatum) to three chloride concentrations (1 mg/L, 145 mg/L, 945 mg/L) for nine days, then transferred clutches to control water for nine days, and measured change in mass at three-day intervals. We measured mass change because water uptake by clutches reduces risks to embryos associated with freezing, predation, and disease. Clutches in controls sequestered water asymptotically. Those in the moderate concentrations lost 18% mass initially and regained 14% after transfer to control water. Clutches in high concentration lost 33% mass and then lost an additional 8% after transfer. Our results suggest that spring rains do not ameliorate the effects of deicing salts in wetlands with extremely high chloride concentrations. - Road deicing salts irreversibly disrupts osmoregulation of salamander egg clutches.

  13. Road deicing salt irreversibly disrupts osmoregulation of salamander egg clutches

    Energy Technology Data Exchange (ETDEWEB)

    Karraker, Nancy E., E-mail: karraker@hku.hk [Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210 (United States); Gibbs, James P [Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210 (United States)

    2011-03-15

    It has been postulated that road deicing salts are sufficiently diluted by spring rains to ameliorate any physiological impacts to amphibians breeding in wetlands near roads. We tested this conjecture by exposing clutches of the spotted salamander (Ambystoma maculatum) to three chloride concentrations (1 mg/L, 145 mg/L, 945 mg/L) for nine days, then transferred clutches to control water for nine days, and measured change in mass at three-day intervals. We measured mass change because water uptake by clutches reduces risks to embryos associated with freezing, predation, and disease. Clutches in controls sequestered water asymptotically. Those in the moderate concentrations lost 18% mass initially and regained 14% after transfer to control water. Clutches in high concentration lost 33% mass and then lost an additional 8% after transfer. Our results suggest that spring rains do not ameliorate the effects of deicing salts in wetlands with extremely high chloride concentrations. - Road deicing salts irreversibly disrupts osmoregulation of salamander egg clutches.

  14. Immediate newborn care practices delay thermoregulation and breastfeeding initiation

    Science.gov (United States)

    Sobel, Howard L; Silvestre, Maria Asuncion A; Mantaring, Jacinto Blas V; Oliveros, Yolanda E; Nyunt-U, Soe

    2011-01-01

    Aim A deadly nosocomial outbreak in a Philippine hospital drew nationwide attention to neonatal sepsis. Together with specific infection control measures, interventions that protect newborns against infection-related mortality include drying, skin-to-skin contact, delayed cord clamping, breastfeeding initiation and delayed bathing. This evaluation characterized hospital care in the first hours of life with the intent to drive policy change, strategic planning and hospital reform. Methods Trained physicians observed 481 consecutive deliveries in 51 hospitals using a standardized tool to record practices and timing of immediate newborn care procedures. Results Drying, weighing, eye care and vitamin K injections were performed in more than 90% of newborns. Only 9.6% were allowed skin-to-skin contact. Interventions were inappropriately sequenced, e.g. immediate cord clamping (median 12 sec), delayed drying (96.5%) and early bathing (90.0%). While 68.2% were put to the breast, they were separated two minutes later. Unnecessary suctioning was performed in 94.9%. Doctors trained in neonatal resuscitation were 2.5 (1.1–5.7) times more likely to unnecessarily suction vigorous newborns. Two per cent died and 5.7% developed sepsis/pneumonia. Conclusions This minute-by-minute observational assessment revealed that performance and timing of immediate newborn care interventions are below WHO standards and deprive newborns of basic protections against infection and death. PMID:21375583

  15. Magnetic particle clutch controls servo system

    Science.gov (United States)

    Fow, P. B.

    1973-01-01

    Magnetic clutches provide alternative means of driving low-power rate or positioning servo systems. They may be used over wide variety of input speed ranges and weigh comparatively little. Power drain is good with overall motor/clutch efficiency greater than 50 percent, and gain of clutch is close to linear, following hysteresis curve of core and rotor material.

  16. Road deicing salt irreversibly disrupts osmoregulation of salamander egg clutches.

    Science.gov (United States)

    Karraker, Nancy E; Gibbs, James P

    2011-03-01

    It has been postulated that road deicing salts are sufficiently diluted by spring rains to ameliorate any physiological impacts to amphibians breeding in wetlands near roads. We tested this conjecture by exposing clutches of the spotted salamander (Ambystoma maculatum) to three chloride concentrations (1 mg/L, 145 mg/L, 945 mg/L) for nine days, then transferred clutches to control water for nine days, and measured change in mass at three-day intervals. We measured mass change because water uptake by clutches reduces risks to embryos associated with freezing, predation, and disease. Clutches in controls sequestered water asymptotically. Those in the moderate concentrations lost 18% mass initially and regained 14% after transfer to control water. Clutches in high concentration lost 33% mass and then lost an additional 8% after transfer. Our results suggest that spring rains do not ameliorate the effects of deicing salts in wetlands with extremely high chloride concentrations. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. High renesting rates in arctic-breeding Dunlin (Calidris alpina): A clutch-removal experiment

    Science.gov (United States)

    Gates, H. River; Lanctot, Richard B.; Powell, Abby N.

    2013-01-01

    The propensity to replace a clutch is a complex component of avian reproduction and poorly understood. We experimentally removed clutches from an Arctic-breeding shorebird, the Dunlin (Calidris alpina arcticola), during early and late stages of incubation to investigate replacement clutch rates, renesting interval, and mate and site fidelity between nesting attempts. In contrast to other Arctic studies, we documented renesting by radiotracking individuals to find replacement clutches. We also examined clutch size and mean egg volume to document changes in individual females’ investment in initial and replacement clutches. Finally, we examined the influence of adult body mass, clutch volume, dates of clutch initiation and nest loss, and year on the propensity to renest. We found high (82–95%) and moderate (35–50%) rates of renesting for early and late incubation treatments. Renesting intervals averaged 4.7–6.8 days and were not different for clutches removed early or late in incubation. Most pairs remained together for renesting attempts. Larger females were more likely to replace a clutch; female body mass was the most important parameter predicting propensity to renest. Clutches lost later in the season were less likely to be replaced. We present evidence that renesting is more common in Arctic-breeding shorebirds than was previously thought, and suggest that renesting is constrained by energetic and temporal factors as well as mate availability. Obtaining rates of renesting in species breeding at different latitudes will help determine when this behavior is likely to occur; such information is necessary for demographic models that include individual and population-level fecundity estimates.

  18. Clutches and brakes design and selection

    CERN Document Server

    Orthwein, William C

    2004-01-01

    Conveniently gathering formulas, analytical methods, and graphs for the design and selection of a wide variety of brakes and clutches in the automotive, aircraft, farming, and manufacturing industries, Clutches and Brakes: Design and Selection, Second Edition simplifies calculations, acquaints engineers with an expansive range of application, and assists in the selection of parameters for specific design challenges. Contains an abundance of examples, 550 display equations, and more than 200 figures for clear presentation of various design strategies Thoroughly revised throughout, the second edition offers… Additional chapters on friction drives and fluid clutches and retarders An extended discussion on cone brakes and clutches A simpler formulation of the torque from a centrifugal clutch Updated sections on automatic braking systems An analysis of variable-speed friction drives with clutch capability Analytical and computer-assisted design techniques.

  19. Study of a magnetorheological grease clutch

    International Nuclear Information System (INIS)

    Kavlicoglu, Barkan M; Gordaninejad, Faramarz; Wang, Xiaojie

    2013-01-01

    In high-speed viscous clutch applications that require low drag (viscous) torque, magnetorheological (MR) fluids are problematic due to their plastic viscosity. As the clutch speed increases the drag torque might exceed the allowable drag torque limit, because the viscous torque is proportional to the speed. To eliminate this problem, various MR greases are utilized in a clutch and their performance is examined. In the experimental study, the torque transfer capacity of a double-plate clutch for operating speeds up to 1200 rpm is conducted. Six different MR greases with various particle loadings and particle sizes are evaluated in the clutch. The rheological properties of MR grease with 90% particle loading in weight are compared with a commercially available MR fluid. The torque performance of the MR grease clutch is also compared with that of the clutch using MR fluid. It is demonstrated that the off-state (no applied magnetic field) torque output of the MR grease clutch is constant in the tested range of the operating speed. In contrast, the torque capacity of the clutch with MR fluid shows a strong dependence on the operating speed. Moreover, it is shown that the iron particle size of the MR grease does not affect the torque output. The MR greases demonstrated an up to 75% increase in the torque capacity compared to the commercial MR fluid. (paper)

  20. Myocardial delayed-enhancement CT: initial experience in children and young adults

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2017-10-15

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  1. Myocardial delayed-enhancement CT: initial experience in children and young adults

    International Nuclear Information System (INIS)

    Goo, Hyun Woo

    2017-01-01

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  2. Variation formulae for the solutions of delay differential equations with discontinuous initial conditions

    International Nuclear Information System (INIS)

    Kharatishvili, G L; Tadumadze, T A

    2005-01-01

    Variation formulae are proved for solutions of non-linear differential equations with variable delays and discontinuous initial conditions. The discontinuity of the initial condition means that at the initial moment of time the values of the initial function and the trajectory, generally speaking, do not coincide. The formulae obtained contain a new summand connected with the discontinuity of the initial condition and the variation of the initial moment.

  3. Electromagnetic brake/clutch device

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1994-01-01

    An electromagnetic brake/clutch device includes a drive shaft supported by at least one bearing for transmitting torque, a housing, affixed to prevent its rotation, surrounding the drive shaft, and an electromagnetically activated device within the housing to selectively prevent and allow rotation of the drive shaft. The electromagnetically activated device includes a plurality of cammed rollers to prevent counter-clockwise rotation of the drive shaft. The drive shaft includes a circumferential disk and the housing includes a reaction ring for engagement with the plurality of cammed rollers. The plurality of cammed rollers are released from engagement with the circumferential disk and the reaction ring by a plurality of tripping mechanisms within the housing. The tripping action uses the locking force to act as a release force merely by changing the boundary conditions of the roller interface angles. The tripping mechanisms include trippers for disengaging the plurality of cammed rollers and an anvil shaped portion for providing lateral movement of the trippers. The plurality of cammed rollers is preloaded to engagement with the circumferential disk and reaction ring by a spring, and is located with respect to an adjacent tripping mechanism with another spring.

  4. Gamma-ray induced delay of fruiting body initiation in a basidiomycete, Hebeloma vinosophyllum

    International Nuclear Information System (INIS)

    Takimoto, K.

    1980-01-01

    The effect of gamma-radiation on fruiting body initiation in a basidiomycete, Hebeloma vinosophyllum, was investigated. Fruiting of this fungus is induced by visible light, but irradiation of the mycelium before or after light treatment delayed fruiting body initiation. The time required for fruiting body initiation increased with the radiation dose. The induction of fruiting bodies had two gamma-radiation sensitive stages, one immediately before fruiting body initiation and the other 15 to 20 h after the start of photoinduction. (author)

  5. Factors associated with delays in treatment initiation after tuberculosis diagnosis in two districts of India.

    Directory of Open Access Journals (Sweden)

    Durba Paul

    Full Text Available BACKGROUND: Excessive time between diagnosis and initiation of tuberculosis (TB treatment contributes to ongoing TB transmission and should be minimized. In India, Revised National TB Control Programme (RNTCP focuses on indicator start of treatment within 7 days of diagnosis for patients with sputum smear-positive PTB for monitoring DOTS implementation. OBJECTIVES: To determine length of time between diagnosis and initiation of treatment and factors associated with delays of more than 7 days in smear-positive pulmonary TB. METHODS: Using existing programme records such as the TB Register, treatment cards, and the laboratory register, we conducted a retrospective cohort study of all patients with smear-positive pulmonary TB registered from July-September 2010 in two districts in India. A random sample of patients with pulmonary TB who experienced treatment delay of more than 7 days was interviewed using structured questionnaire. RESULTS: 2027 of 3411 patients registered with pulmonary TB were smear-positive. 711(35% patients had >7 days between diagnosis and treatment and 262(13% had delays >15 days. Mean duration between TB diagnosis and treatment initiation was 8 days (range = 0-128 days. Odds of treatment delay >7 days was 1.8 times more likely among those who had been previously treated (95% confidence interval [CI] 1.5-2.3 and 1.6 (95% CI 1.3-1.8 times more likely among those diagnosed in health facilities without microscopy centers. The main factors associated with a delay >7 days were: patient reluctance to start a re-treatment regimen, patients seeking second opinions, delay in transportation of drugs to the DOT centers and delay in initial home visits. To conclude, treatment delay >7 days was associated with a number of factors that included history of previous treatment and absence of TB diagnostic services in the local health facility. Decentralized diagnostic facilities and improved referral procedures may reduce such treatment

  6. Offspring fitness and individual optimization of clutch size

    Science.gov (United States)

    Both, C.; Tinbergen, J. M.; Noordwijk, A. J. van

    1998-01-01

    Within-year variation in clutch size has been claimed to be an adaptation to variation in the individual capacity to raise offspring. We tested this hypothesis by manipulating brood size to one common size, and predicted that if clutch size is individually optimized, then birds with originally large clutches have a higher fitness than birds with originally small clutches. No evidence was found that fitness was related to the original clutch size, and in this population clutch size is thus not related to the parental capacity to raise offspring. However, offspring from larger original clutches recruited better than their nest mates that came from smaller original clutches. This suggests that early maternal or genetic variation in viability is related to clutch size.

  7. The Haiti Breast Cancer Initiative: Initial Findings and Analysis of Barriers-to-Care Delaying Patient Presentation

    Directory of Open Access Journals (Sweden)

    Ketan Sharma

    2013-01-01

    Full Text Available Background. In Haiti, breast cancer patients present at such advanced stages that even modern therapies offer modest survival benefit. Identifying the personal, sociocultural, and economic barriers-to-care delaying patient presentation is crucial to controlling disease. Methods. Patients presenting to the Hôpital Bon Sauveur in Cange were prospectively accrued. Delay was defined as 12 weeks or longer from initial sign/symptom discovery to presentation, as durations greater than this cutoff correlate with reduced survival. A matched case-control analysis with multivariate logistic regression was used to identify factors predicting delay. Results. Of N=123 patients accrued, 90 (73% reported symptom-presentation duration and formed the basis of this study: 52 patients presented within 12 weeks of symptoms, while 38 patients waited longer than 12 weeks. On logistic regression, lower education status (OR = 5.6, P=0.03, failure to initially recognize mass as important (OR = 13.0, P<0.01, and fear of treatment cost (OR = 8.3, P=0.03 were shown to independently predict delayed patient presentation. Conclusion. To reduce stage at presentation, future interventions must educate patients on the recognition of initial breast cancer signs and symptoms and address cost concerns by providing care free of charge and/or advertising that existing care is already free.

  8. Initiation of delayed hydride cracking in zirconium-2.5 wt% niobium

    International Nuclear Information System (INIS)

    Shalabi, A.F.; Meneley, D.A.

    1990-01-01

    Delayed hydride cracking in zirconium alloys is caused by the repeated precipitation and cracking of brittle hydrides. The growth kinetic of the hydrides have been measured to evaluate the critical hydride length for crack initiation. Hydride growth leading to crack initiation follows an approximate (time) 1/3 law on the average; crack propagation proceeds in a stepwise fashion. The critical length of hydride for crack initiation increases with stress and temperature. The fracture criterion for crack initiation predicts the critical hydride length at a give stress level and temperature. The fracture initiation mechanism of the hydride confirms the temperature effects for heating and cooling cycles under services loads. (orig.)

  9. Delay of Treatment Initiation Does Not Adversely Affect Survival Outcome in Breast Cancer.

    Science.gov (United States)

    Yoo, Tae-Kyung; Han, Wonshik; Moon, Hyeong-Gon; Kim, Jisun; Lee, Jun Woo; Kim, Min Kyoon; Lee, Eunshin; Kim, Jongjin; Noh, Dong-Young

    2016-07-01

    Previous studies examining the relationship between time to treatment and survival outcome in breast cancer have shown inconsistent results. The aim of this study was to analyze the overall impact of delay of treatment initiation on patient survival and to determine whether certain subgroups require more prompt initiation of treatment. This study is a retrospective analysis of stage I-III patients who were treated in a single tertiary institution between 2005 and 2008. Kaplan-Meier survival analysis and Cox proportional hazards regression model were used to evaluate the impact of interval between diagnosis and treatment initiation in breast cancer and various subgroups. A total of 1,702 patients were included. Factors associated with longer delay of treatment initiation were diagnosis at another hospital, medical comorbidities, and procedures performed before admission for surgery. An interval between diagnosis and treatment initiation as a continuous variable or with a cutoff value of 15, 30, 45, and 60 days had no impact on disease-free survival (DFS). Subgroup analyses for hormone-responsiveness, triple-negative breast cancer, young age, clinical stage, and type of initial treatment showed no significant association between longer delay of treatment initiation and DFS. Our results show that an interval between diagnosis and treatment initiation of 60 days or shorter does not appear to adversely affect DFS in breast cancer.

  10. Stability with respect to initial time difference for generalized delay differential equations

    Directory of Open Access Journals (Sweden)

    Ravi Agarwal

    2015-02-01

    Full Text Available Stability with initial data difference for nonlinear delay differential equations is introduced. This type of stability generalizes the known concept of stability in the literature. It gives us the opportunity to compare the behavior of two nonzero solutions when both initial values and initial intervals are different. Several sufficient conditions for stability and for asymptotic stability with initial time difference are obtained. Lyapunov functions as well as comparison results for scalar ordinary differential equations are employed. Several examples are given to illustrate the theory.

  11. Initiation of nutritional support is delayed in critically ill obese patients: a multicenter cohort study.

    Science.gov (United States)

    Borel, Anne-Laure; Schwebel, Carole; Planquette, Benjamin; Vésin, Aurélien; Garrouste-Orgeas, Maité; Adrie, Christophe; Clec'h, Christophe; Azoulay, Elie; Souweine, Bertrand; Allaouchiche, Bernard; Goldgran-Toledano, Dany; Jamali, Samir; Darmon, Michael; Timsit, Jean-François

    2014-09-01

    A high catabolic rate characterizes the acute phase of critical illness. Guidelines recommend an early nutritional support, regardless of the previous nutritional status. We aimed to assess whether the nutritional status of patients, which was defined by the body mass index (BMI) at admission in an intensive care unit (ICU), affected the time of nutritional support initiation. We conducted a cohort study that reported a retrospective analysis of a multicenter ICU database (OUTCOMEREA) by using data prospectively entered from January 1997 to October 2012. Patients who needed orotracheal intubation within the first 72 h and >3 d were included. Data from 3257 ICU stays were analyzed. The delay before feeding was different according to BMI groups (P = 0.035). The delay was longer in obese patients [BMI (in kg/m²) ≥30; n = 663] than in other patients with either low weight (BMI nutritional status and a delay in nutrition initiation was independent of potential confounding factors such as age, sex, and diabetes or other chronic diseases. In comparison with normal weight, the adjusted RR (95% CI) associated with a delayed nutrition initiation was 0.92 (0.86, 0.98) for patients with low weight, 1.00 (0.94, 1.05) for overweight patients, and 1.06 (1.00, 1.12) for obese patients (P = 0.004). The initiation of nutritional support was delayed in obese ICU patients. Randomized controlled trials that address consequences of early compared with delayed beginnings of nutritional support in critically ill obese patients are needed. © 2014 American Society for Nutrition.

  12. Application of the variational iteration method for system of initial value problems delay differential equations

    Science.gov (United States)

    Yousef, Hamood. M.; Ismail, A. I. B. MD.

    2017-08-01

    Many attempts have been presented to solve the system of Delay Differential Equations (DDE) with Initial Value Problem. As a result, it has shown difficulties when getting the solution or cannot be solved. In this paper, a Variational Iteration Method is employed to find out an approximate solution for the system of DDE with initial value problems. The example illustrates convenient and an efficiency comparison with the exact solution.

  13. Time Delay for the Initiation of an Emergency Shutdown at the Peruvian Nuclear Reactor RP-10

    International Nuclear Information System (INIS)

    Ramon, A.; Ovalle, E.; Canaza, D.; Salazar, A.; Zapata, A.; Felix, J.; Arrieta, R.; Vela, M.

    2008-01-01

    In this paper we show the measurement of the time delay for the initiation of an emergency shutdown state at the RP-10 Reactor. This time delay is the one corresponding to the delay between the detection of a signal of any fixed limit and the start of a protective action to get the reactor in a safety state. The experimental method used is based on monitoring two signals in an oscilloscope, one signal is the elected initiate event and the other is the de-energizing of electromagnets of the security bars. The time delay for each safety and control rods, was measured for seven energizing current values in a range of 36 - 52 mA. The results showed that the minimum value is (84 ± 1.26) ms and the maximum is (108 ± 1.60) ms. In all cases it is noted that, the delay time is less than the limit values prefixed down in the reactor safety report. (authors)

  14. A Novel Approach for Enhancement of Automobile Clutch Engagement Quality Using Mechatronics Based Automated Clutch System

    Science.gov (United States)

    Tripathi, K.

    2013-01-01

    In automated manual clutch (AMC) a mechatronic system controls clutch force trajectory through an actuator governed by a control system. The present study identifies relevant characteristics of this trajectory and their effects on driveline dynamics and engagement quality. A new type of force trajectory is identified which gives the good engagement quality. However this trajectory is not achievable through conventional clutch control mechanism. But in AMC a mechatronic system based on electro-hydraulic or electro-mechanical elements can make it feasible. A mechatronic system is presented in which a mechatronic add-on system can be used to implement the novel force trajectory, without the requirement of replacing the traditional diaphragm spring based clutch in a vehicle with manual transmission.

  15. Longitudinal Associations Among Religiousness, Delay Discounting, and Substance Use Initiation in Early Adolescence.

    Science.gov (United States)

    Kim-Spoon, Jungmeen; McCullough, Michael E; Bickel, W K; Farley, Julee P; Longo, Gregory S

    2015-03-01

    Prior research indicates that religiousness is related negatively to adolescent health risk behaviors, yet how such protective effects operate is not well understood. This study examined the longitudinal associations among organizational and personal religiousness, delay discounting, and substance use initiation (alcohol, cigarette, and marijuana use). The sample comprised 106 early adolescents (10-13 years of age, 52% female) who were not using substances at Time 1. Path analyses suggested that high levels of personal religiousness at Time 1 were related to low levels of substance use at Time 2 (2.4 years later), mediated by low levels of delay discounting. Delay discounting appears to be an important contributor to the protective effect of religiousness on the development of substance use among adolescents.

  16. [Impact of care pathway on the delay for initiation of antituberculosis treatment in Conakry, Guinea].

    Science.gov (United States)

    Camara, A; Bah-Sow, O Y; Baldé, N M; Camara, L M; Barry, I S; Bah, B; Diallo, M; Chaperon, J; Riou, F

    2009-06-01

    Complex care pathways can result in detrimental treatment delay particularly in tuberculosis patients. The purpose of this retrospective study was to assess the care pathways followed by tuberculosis patients prior to diagnosis and to assess impact on the delay for initiation of treatment in Conakry, Guinea. A total of 112 patients were interviewed at the time of first admission for pulmonary tuberculosis with positive bacilloscopy. Based on interview data, pathways were classified as conventional (use of health care facilities only) and mixed (use of health care facilities, self-medication, and traditional medicine). The correlation between patient characteristics and type of pathway was assessed by univariate and multivariate analysis and the two groups, i.e., conventional vs. mixed, were compared with regard to delay for initiation of treatment. The care pathway was classified as mixed in two out of three patients. Multivariate analysis showed that this type of pathway was only correlated with schooling (p=0.02). The mean delay for treatment was similar, i.e., 13.4 and 12.8 weeks for conventional and mixed pathways respectively (p<0.68). The percentage of pathways including three consultations at health care facilities was significantly higher in the conventional than mixed group (72% vs. 30%, p<0.001). The main reasons given for delayed use of health care facilities were poor knowledge of tuberculosis symptoms (26%) and high cost of care (12%). The findings of this study indicate that tuberculosis patients follow a variety of care pathways that can lead to delayed treatment. An information campaign is needed to increase awareness among the population and care providers.

  17. Beyond size–number trade-offs: clutch size as a maternal effect

    Science.gov (United States)

    Brown, Gregory P.; Shine, Richard

    2009-01-01

    Traditionally, research on life-history traits has viewed the link between clutch size and offspring size as a straightforward linear trade-off; the product of these two components is taken as a measure of maternal reproductive output. Investing more per egg results in fewer but larger eggs and, hence, offspring. This simple size–number trade-off has proved attractive to modellers, but our experimental studies on keelback snakes (Tropidonophis mairii, Colubridae) reveal a more complex relationship between clutch size and offspring size. At constant water availability, the amount of water taken up by a snake egg depends upon the number of adjacent eggs. In turn, water uptake affects hatchling size, and therefore an increase in clutch size directly increases offspring size (and thus fitness under field conditions). This allometric advantage may influence the evolution of reproductive traits such as growth versus reproductive effort, optimal age at female maturation, the body-reserve threshold required to initiate reproduction and nest-site selection (e.g. communal oviposition). The published literature suggests that similar kinds of complex effects of clutch size on offspring viability are widespread in both vertebrates and invertebrates. Our results also challenge conventional experimental methodologies such as split-clutch designs for laboratory incubation studies: by separating an egg from its siblings, we may directly affect offspring size and thus viability. PMID:19324614

  18. Clutch size declines with elevation in tropical birds

    Science.gov (United States)

    Boyce, A.J.; Freeman, Benjamin G.; Mitchell, Adam E.; Martin, Thomas E.

    2015-01-01

    Clutch size commonly decreases with increasing elevation among temperate-zone and subtropical songbird species. Tropical songbirds typically lay small clutches, thus the ability to evolve even smaller clutch sizes at higher elevations is unclear and untested. We conducted a comparative phylogenetic analysis using data gathered from the literature to test whether clutch size varied with elevation among forest passerines from three tropical biogeographic regions—the Venezuelan Andes and adjacent lowlands, Malaysian Borneo, and New Guinea. We found a significant negative effect of elevation on variation in clutch size among species. We found the same pattern using field data sampled across elevational gradients in Venezuela and Malaysian Borneo. Field data were not available for New Guinea. Both sets of results demonstrate that tropical montane species across disparate biogeographic realms lay smaller clutches than closely related low-elevation species. The environmental sources of selection underlying this pattern remain uncertain and merit further investigation.

  19. Studies on centrifugal clutch judder behavior and the design of frictional lining materials

    Science.gov (United States)

    Li, Tse-Chang; Huang, Yu-Wen; Lin, Jen-Fin

    2016-01-01

    This study examines the judder behavior of a centrifugal clutch from the start of hot spots in the conformal contact, then the repeated developments of thermoelastic instability, and finally the formation of cyclic undulations in the vibrations, friction coefficient and torque. This behavior is proved to be consistent with the testing results. Using the Taguchi method, 18 kinds of frictional lining specimens were prepared in order to investigate their performance in judder resistance and establish a relationship between judder behavior and the Ts/Td (Ts: static torque; Td: dynamic torque) and dμ/dVx (μ: friction coefficient; Vx: relative sliding velocity of frictional lining and clutch drum) parameters. These specimens are also provided to examine the effects and profitability with regard to the centrifugal clutch, and find the relative importance of the various control factors. Theoretical models for the friction coefficient (μ), the critical sliding velocity (Vc) with clutch judder, and the contact pressure ratio p* /pbar (p*: pressure undulation w.r.t. pbar; pbar: mean contact pressure) and temperature corresponding to judder behavior are developed. The parameters of the contact pressure ratio and temperature are shown to be helpful to explain the occurrence of judder. The frictional torque and the rotational speeds of the driveline, clutch, and clutch drum as functions of engagement time for 100 clutch cycles are obtained experimentally to evaluate dμ/dVx and Ts/Td. A sharp rise in the maximum p* /pbar occurred when the relative sliding velocity reached the critical velocity, Vc. An increase in the maximum p* /pbar generally led to an increase of the (initially negative) dμ/dVx value, and thus the severity of judder. The fluctuation intensity of dμ/dVx becomes a governing factor of the growth of dμ/dVx itself in the engagement process. The mean values of dμ/dVx and Ts/Td for the clutching tests with 100 cycles can be roughly divided into three groups

  20. Camouflage and Clutch Survival in Plovers and Terns

    Science.gov (United States)

    Stoddard, Mary Caswell; Kupán, Krisztina; Eyster, Harold N.; Rojas-Abreu, Wendoly; Cruz-López, Medardo; Serrano-Meneses, Martín Alejandro; Küpper, Clemens

    2016-09-01

    Animals achieve camouflage through a variety of mechanisms, of which background matching and disruptive coloration are likely the most common. Although many studies have investigated camouflage mechanisms using artificial stimuli and in lab experiments, less work has addressed camouflage in the wild. Here we examine egg camouflage in clutches laid by ground-nesting Snowy Plovers Charadrius nivosus and Least Terns Sternula antillarum breeding in mixed aggregations at Bahía de Ceuta, Sinaloa, Mexico. We obtained digital images of clutches laid by both species. We then calibrated the images and used custom computer software and edge detection algorithms to quantify measures related to three potential camouflage mechanisms: pattern complexity matching, disruptive effects and background color matching. Based on our image analyses, Snowy Plover clutches, in general, appeared to be more camouflaged than Least Tern clutches. Snowy Plover clutches also survived better than Least Tern clutches. Unexpectedly, variation in clutch survival was not explained by any measure of egg camouflage in either species. We conclude that measures of egg camouflage are poor predictors of clutch survival in this population. The behavior of the incubating parents may also affect clutch predation. Determining the significance of egg camouflage requires further testing using visual models and behavioral experiments.

  1. Reasons for delaying or engaging in early sexual initiation among adolescents in Nigeria

    Directory of Open Access Journals (Sweden)

    Ankomah A

    2011-09-01

    Full Text Available Augustine Ankomah1, Fatima Mamman-Daura2, Godpower Omoregie1, Jennifer Anyanti11Society for Family Health, Abuja; 2Pathfinder International/Nigeria, Kaduna Field Office, Kaduna, NigeriaBackground: Annually, over 1 million births in Nigeria are to teenage mothers. Many of these pregnancies are unwanted and these mothers are also exposed to the risk of human immunodeficiency virus (HIV infection. Sexual abstinence is a critical preventative health strategy. Several quantitative studies in Nigeria have identified the correlates and determinants of early sex, yet few have explored in depth the underlying reasons for early sex. This paper explores both the key factors that motivate some unmarried young people to engage in early sex and reasons why some delay.Methods: This qualitative study was based on data from 30 focus group discussions held with unmarried 14- to 19-year-olds in four geographically and culturally dispersed Nigerian states. Focus groups were stratified by sexual experience to capture variations among different subgroups.Results: Several reasons for early premarital sex were identified. The “push” factors included situations where parents exposed young female adolescents to street trading. “Pull” factors, particularly for males, included the pervasive viewing of locally produced movies, peer pressure and, for females, transactional sex (where adolescent girls exchange sex for gifts, cash, or other favors. Also noted were overtly coercive factors, including rape. There were also myths and misconceptions that “justified” early sexual initiation. Reasons cited for delay included religious injunction against premarital sex; disease prevention (especially HIV/acquired immunodeficiency syndrome; fear of pregnancy, and linked to this, the fear of dropping out of school; and, for females, the fear of bringing shame to the family, which could lead to their inability to get a "good" husband in the future.Conclusion: The differences

  2. Clutches using engineering ceramics as friction material

    Energy Technology Data Exchange (ETDEWEB)

    Albers, A.; Arslan, A.; Mitariu, M. [Universitaet Karlsruhe (T.H.), IPEK - Institut fuer Produktentwicklung, Kaiserstr. 10, 76131 Karlsruhe (Germany)

    2005-03-01

    The experimental and constructive results illustrate that engineering ceramic materials have a high potential in the field of dry running friction systems. According to first estimations, it is possible to build the vehicle clutch 53 % smaller or to transmit up to 180 % higher torque with the same size by an appropriate selection of the system friction pairing and an adequate ceramic design [1, 2]. The friction coefficient characteristic (decreasing friction coefficient above sliding speed) is unfavourable with regard to comfort (self-induced grab oscillations [3]) of the vehicle clutch. Furthermore, it is important to select the test procedure of the experimental analyses to be as close to the system as possible in order to obtain exact information concerning the target system. (Abstract Copyright [2005], Wiley Periodicals, Inc.) [German] Die experimentellen und konstruktiven Ergebnisse haben gezeigt, dass ingenieurkeramische Werkstoffe ein hohes Potenzial im Bereich der trockenlaufenden Friktionssysteme haben. Durch geeignete Wahl der Systemreibpaarung und eine keramikgerechte Konstruktion ist es nach ersten Abschaetzungen moeglich, die Kfz-Kupplung um 53 % kleiner zu bauen bzw. bei gleicher Groesse bis zu 180 % hoehere Drehmomente zu uebertragen [1, 2]. Die Reibungszahlcharakteristik (fallende Reibungszahl ueber Gleitgeschwindigkeit) ist im Hinblick auf Komfort (selbsterregte Rupfschwingungen [3]) fuer die Kraftfahrzeugkupplung unguenstig. Des Weiteren ist es wichtig, die Versuchsfuehrung der experimentellen Untersuchungen so systemnah wie moeglich zu waehlen, um genauere Aussagen auf das Zielsystem zu erhalten. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  3. Factors influencing offspring traits in the oviparous multi-clutched ...

    Indian Academy of Sciences (India)

    Unknown

    Calotes versicolor, a multi-clutched oviparous lizard. (Shanbhag and Prasad ... composes correlation between two variables in to: (i) the direct effect of the first ... color breeding time is the prime factor that influences the clutch mass and egg ...

  4. Simulation and control of an automotive dry clutch

    NARCIS (Netherlands)

    Serrarens, A.F.A.; Dassen, M.; Steinbuch, M.

    2004-01-01

    In this paper the dynamic behavior and control of an automotive dry clutch is analyzed. Thereto, a straight-forward model of the clutch is embedded within a dynamic model of an automotive powertrain comprising an internal combustion engine, drivetrain and wheels moving a vehicle through tire-road

  5. A magnetorheological clutch for efficient automotive auxiliary device actuation

    Directory of Open Access Journals (Sweden)

    F. Bucchi

    2013-01-01

    Full Text Available In this paper the results of a project funded by Regione Toscana aimed at reducing the power absorption of auxiliary devices in vehicles are presented. In particular the design, testing and application of a magnetorheological clutch (MR is proposed, aimed at disengaging the vacuum pump, which draws in air from the power-brake booster chamber, in order to reduce the device power absorption. Several clutch preliminary studies done to choose the clutch geometry and the magnetic field supply are illustrated. The final choice consisted in an MR clutch with permanent magnet, which satisfied size, torque and fail-safe specifications. The clutch characteristics, in terms of torque versus slip, were obtained experimentally for three different clutch prototypes on an ad-hoc developed test bench.As result of a preliminary simulation, a comparison between the power absorption of a current production vacuum pump, an innovative vacuum pump and both vacuum pumps coupled with the MR clutch is presented. The New European Driving Cycle is considered for simulating the vacuum pump operation both in urban and highway driving. Results show that the use of the innovative vacuum pump reduces the device consumption of about 35%, whereas the use of MR clutch coupled with the innovative vacuum pump reduces it up to about 44% in urban driving and 50% in highway driving.

  6. Effect of ATF on frictional property of wet-type clutch; Shisshiki crutch (hasshin clutch) no masatsu tokusei ni oyobosu ATF no eikyosei

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, J; Nagashima, T; Yamane, T; Kawauchi, s; Hirao, Y [Honda R and D Co. Ltd., Tokyo (Japan)

    1997-10-01

    As a starting device for continuously variable transmission, wet-type multiple disc clutch installed to the driven side (Starting clutch system) is suitable system. Starting clutch system is feared to occur the judder phenomenon, because it is used at low slipping velocity like a lock up clutch. In this report, we studied to prevent the judder phenomenon about the effect of automatic transmission fluid on frictional property of the wet-type clutch. 6 refs., 7 figs., 2 tabs.

  7. Delays before Diagnosis and Initiation of Treatment in Patients Presenting to Mental Health Services with Bipolar Disorder.

    Science.gov (United States)

    Patel, Rashmi; Shetty, Hitesh; Jackson, Richard; Broadbent, Matthew; Stewart, Robert; Boydell, Jane; McGuire, Philip; Taylor, Matthew

    2015-01-01

    Bipolar disorder is a significant cause of morbidity and mortality. Although existing treatments are effective, there is often a substantial delay before diagnosis and treatment initiation. We sought to investigate factors associated with the delay before diagnosis of bipolar disorder and the onset of treatment in secondary mental healthcare. Retrospective cohort study using anonymised electronic mental health record data from the South London and Maudsley NHS Foundation Trust (SLaM) Biomedical Research Centre (BRC) Case Register on 1364 adults diagnosed with bipolar disorder between 2007 and 2012. The following predictor variables were analysed in a multivariable Cox regression analysis: age, gender, ethnicity, compulsory admission to hospital under the UK Mental Health Act, marital status and other diagnoses prior to bipolar disorder. The outcomes were time to recorded diagnosis from first presentation to specialist mental health services (the diagnostic delay), and time to the start of appropriate therapy (treatment delay). The median diagnostic delay was 62 days (interquartile range: 17-243) and median treatment delay was 31 days (4-122). Compulsory hospital admission was associated with a significant reduction in both diagnostic delay (hazard ratio 2.58, 95% CI 2.18-3.06) and treatment delay (4.40, 3.63-5.62). Prior diagnoses of other psychiatric disorders were associated with increased diagnostic delay, particularly alcohol (0.48, 0.33-0.41) and substance misuse disorders (0.44, 0.31-0.61). Prior diagnosis of schizophrenia and psychotic depression were associated with reduced treatment delay. Some individuals experience a significant delay in diagnosis and treatment of bipolar disorder after initiation of specialist mental healthcare, particularly those who have prior diagnoses of alcohol and substance misuse disorders. These findings highlight a need for further study on strategies to better identify underlying symptoms and offer appropriate treatment sooner

  8. Delays before Diagnosis and Initiation of Treatment in Patients Presenting to Mental Health Services with Bipolar Disorder.

    Directory of Open Access Journals (Sweden)

    Rashmi Patel

    Full Text Available Bipolar disorder is a significant cause of morbidity and mortality. Although existing treatments are effective, there is often a substantial delay before diagnosis and treatment initiation. We sought to investigate factors associated with the delay before diagnosis of bipolar disorder and the onset of treatment in secondary mental healthcare.Retrospective cohort study using anonymised electronic mental health record data from the South London and Maudsley NHS Foundation Trust (SLaM Biomedical Research Centre (BRC Case Register on 1364 adults diagnosed with bipolar disorder between 2007 and 2012. The following predictor variables were analysed in a multivariable Cox regression analysis: age, gender, ethnicity, compulsory admission to hospital under the UK Mental Health Act, marital status and other diagnoses prior to bipolar disorder. The outcomes were time to recorded diagnosis from first presentation to specialist mental health services (the diagnostic delay, and time to the start of appropriate therapy (treatment delay.The median diagnostic delay was 62 days (interquartile range: 17-243 and median treatment delay was 31 days (4-122. Compulsory hospital admission was associated with a significant reduction in both diagnostic delay (hazard ratio 2.58, 95% CI 2.18-3.06 and treatment delay (4.40, 3.63-5.62. Prior diagnoses of other psychiatric disorders were associated with increased diagnostic delay, particularly alcohol (0.48, 0.33-0.41 and substance misuse disorders (0.44, 0.31-0.61. Prior diagnosis of schizophrenia and psychotic depression were associated with reduced treatment delay.Some individuals experience a significant delay in diagnosis and treatment of bipolar disorder after initiation of specialist mental healthcare, particularly those who have prior diagnoses of alcohol and substance misuse disorders. These findings highlight a need for further study on strategies to better identify underlying symptoms and offer appropriate treatment

  9. Predictors on delay of initial health-seeking in new pulmonary tuberculosis cases among migrants population in East China.

    Directory of Open Access Journals (Sweden)

    Xinxu Li

    Full Text Available OBJECTIVES: To determine the length of delay in initial health-seeking in new pulmonary tuberculosis (PTB cases among migrant population in the eastern part of China, and factors associated with it. METHODS: A cross-sectional study was conducted using a structured questionnaire in six counties in Shanghai, Guangdong and Jiangsu from May to October, 2008, to estimate the extent and factors responsible for delayed initial health-seeking of the new PTB cases. The interval between self-reported onset of TB symptoms and date of first attendance at any medical institution was determined. More than the median duration was defined as delayed health-seeking. RESULTS: A total of 323 new migrant PTB patients participated in the study. Only 6.5% had medical insurance. The median and mean durations to initial health-seeking were respectively 10 and 31 days. There was no significant association between socio-demographic factors and delayed initial health-seeking. Average monthly working days >24 (AOR, 1.61; 95% CI, 1.03-2.51, and hemoptysis or bloody sputum (AOR, 0.48; 95% CI, 0.28-0.85 were significantly associated with delayed initial health-seeking. CONCLUSIONS: Interventions to improve health seeking behavior among the migrant population in China must focus on strengthening their labor, medical security and health education.

  10. Origin of evolutionary change in avian clutch size.

    Science.gov (United States)

    Haywood, Sacha

    2013-11-01

    Why different bird species lay different numbers of eggs is a question that has long been associated with factors external to the organism, that is, factors which operate on inherited variation in clutch size through the action of natural selection. Yet, while external factors are important, the extent of what is evolutionarily possible rests with the mechanisms developed by birds for clutch-size control. Hitherto neglected, these mechanisms generate factors internal to the organism that are central to the origin of evolutionary change. They are related to the fact that a species-specific range of clutch size arises from the differential survival of pre-ovulatory follicles undergoing growth when the signal causing egg laying to end reaches the ovary. Herein, I examine three internal factors that, together with external factors, could impact the evolution of avian clutch size. Each factor acts by changing either the number of pre-ovulatory follicles present in the ovary at the time of follicular disruption or the timing of this event. These changes to clutch size can be explained by the concept of heterochrony. In light of this, the role of phenotypic plasticity and genes determining clutch size is discussed. Finally, to account for the origin of evolutionary change in clutch size, I detail an hypothesis involving a process similar to Waddington's theory of genetic assimilation. © 2013 The Author. Biological Reviews © 2013 Cambridge Philosophical Society.

  11. Delayed Presentation of Ureteropelvic Junction Obstruction and Loss of Renal Function After Initially Mild (SFU Grade 1-2) Hydronephrosis.

    Science.gov (United States)

    Bowen, Diana K; Yerkes, Elizabeth B; Lindgren, Bruce W; Gong, Edward M; Faasse, Mark A

    2015-07-01

    We report 4 pediatric cases of ureteropelvic junction obstruction involving delayed progression of initially mild postnatal hydronephrosis. All 4 children became symptomatic; however, 3 already had a substantial decrement of ipsilateral kidney function by the time of diagnosis. Two of these 3 patients had previous renal scintigraphy demonstrating normal differential function. We caution that counseling regarding hydronephrosis should emphasize the importance of prompt re-evaluation for any symptoms potentially referable to delayed presentation of ureteropelvic junction obstruction, irrespective of initial hydronephrosis grade. Future studies are needed to determine the optimal follow-up regimen for conservative management of hydronephrosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Loss-to-follow-up and delay to treatment initiation in Pakistan's national tuberculosis control programme.

    Science.gov (United States)

    Ali, Syed Mustafa; Naureen, Farah; Noor, Arif; Fatima, Irum; Viney, Kerri; Ishaq, Muhammad; Anjum, Naveed; Rashid, Aamna; Haider, Ghulam Rasool; Khan, Muhammad Aamir; Aamir, Javariya

    2018-03-09

    Researchers and policy-makers have identified loss to follow-up as a major programmatic problem. Therefore, the objective of this study is to quantify TB related pre-treatment loss to follow up and treatment delay in private sector health care facilities in Pakistan. This was a retrospective, descriptive cohort study using routinely collected programmatic data from TB referral, diagnosis and treatment registers. Data from 48 private healthcare facilities were collected using an online questionnaire prepared in ODK Collect, for the period October 2015 to March 2016. Data were analysed using SPSS. We calculated the: (1) number and proportion of patients who were lost to follow-up during the diagnostic period, (2) number and proportion of patients with pre-treatment loss to follow-up, and (3) the number of days between diagnosis and initiation of treatment. One thousand five hundred ninety-six persons with presumptive TB were referred to the laboratory. Of these, 96% (n = 1538) submitted an on-the-spot sputum sample. Of the 1538 people, 1462 (95%) people subsequently visited the laboratory to submit the early morning (i.e. the second) sample. Hence, loss to follow-up during the diagnostic process was 8% overall (n = 134). Of the 1462 people who submitted both sputum samples, 243 (17%) were diagnosed with sputum smear-positive pulmonary TB and 231 were registered for anti-TB treatment, hence, loss in the pre-treatment phase was 4.9% (n = 12). 152 persons with TB (66%) initiated TB treatment either on the day of TB diagnosis or the next day. A further 79 persons with TB (34%) commenced TB treatment within a mean time of 7 days (range 2 to 64 days). Concentrated efforts should be made by the National TB Control Programme to retain TB patients and innovative methods such as text reminders and behavior change communication may need to be used and tested.

  13. Durations and Delays in Care Seeking, Diagnosis and Treatment Initiation in Uncomplicated Pulmonary Tuberculosis Patients in Mumbai, India.

    Directory of Open Access Journals (Sweden)

    Nerges Mistry

    Full Text Available Timely diagnosis and treatment initiation are critical to reduce the chain of transmission of Tuberculosis (TB in places like Mumbai, where almost 60% of the inhabitants reside in overcrowded slums. This study documents the pathway from the onset of symptoms suggestive of TB to initiation of TB treatment and examines factors responsible for delay among uncomplicated pulmonary TB patients in Mumbai.A population-based retrospective survey was conducted in the slums of 15 high TB burden administrative wards to identify 153 self-reported TB patients. Subsequently in-depth interviews of 76 consenting patients that fit the inclusion criteria were undertaken using an open-ended interview schedule. Mean total, first care seeking, diagnosis and treatment initiation duration and delays were computed for new and retreatment patients. Patients showing defined delays were divided into outliers and non-outliers for all three delays using the median values.The mean duration for the total pathway was 65 days with 29% of patients being outliers. Importantly the mean duration of first care seeking was similar in new (24 days and retreatment patients (25 days. Diagnostic duration contributed to 55% of the total pathway largely in new patients. Treatment initiation was noted to be the least among the three durations with mean duration in retreatment patients twice that of new patients. Significantly more female patients experienced diagnostic delay. Major shift of patients from the private to public sector and non-allopaths to allopaths was observed, particularly for treatment initiation.Achieving positive behavioural changes in providers (especially non-allopaths and patients needs to be considered in TB control strategies. Specific attention is required in counselling of TB patients so that timely care seeking is effected at the time of relapse. Prioritizing improvement of environmental health in vulnerable locations and provision of point of care diagnostics

  14. Durations and Delays in Care Seeking, Diagnosis and Treatment Initiation in Uncomplicated Pulmonary Tuberculosis Patients in Mumbai, India.

    Science.gov (United States)

    Mistry, Nerges; Rangan, Sheela; Dholakia, Yatin; Lobo, Eunice; Shah, Shimoni; Patil, Akshaya

    2016-01-01

    Timely diagnosis and treatment initiation are critical to reduce the chain of transmission of Tuberculosis (TB) in places like Mumbai, where almost 60% of the inhabitants reside in overcrowded slums. This study documents the pathway from the onset of symptoms suggestive of TB to initiation of TB treatment and examines factors responsible for delay among uncomplicated pulmonary TB patients in Mumbai. A population-based retrospective survey was conducted in the slums of 15 high TB burden administrative wards to identify 153 self-reported TB patients. Subsequently in-depth interviews of 76 consenting patients that fit the inclusion criteria were undertaken using an open-ended interview schedule. Mean total, first care seeking, diagnosis and treatment initiation duration and delays were computed for new and retreatment patients. Patients showing defined delays were divided into outliers and non-outliers for all three delays using the median values. The mean duration for the total pathway was 65 days with 29% of patients being outliers. Importantly the mean duration of first care seeking was similar in new (24 days) and retreatment patients (25 days). Diagnostic duration contributed to 55% of the total pathway largely in new patients. Treatment initiation was noted to be the least among the three durations with mean duration in retreatment patients twice that of new patients. Significantly more female patients experienced diagnostic delay. Major shift of patients from the private to public sector and non-allopaths to allopaths was observed, particularly for treatment initiation. Achieving positive behavioural changes in providers (especially non-allopaths) and patients needs to be considered in TB control strategies. Specific attention is required in counselling of TB patients so that timely care seeking is effected at the time of relapse. Prioritizing improvement of environmental health in vulnerable locations and provision of point of care diagnostics would be

  15. Modeling and Stability Analysis of Wedge Clutch System

    Directory of Open Access Journals (Sweden)

    Jian Yao

    2014-01-01

    Full Text Available A wedge clutch with unique features of self-reinforcement and small actuation force was designed. Its self-reinforcement feature, associated with different factors such as the wedge angle and friction coefficient, brings different dynamics and unstable problem with improper parameters. To analyze this system, a complete mathematical model of the actuation system is built, which includes the DC motor, the wedge mechanism, and the actuated clutch pack. By considering several nonlinear factors, such as the slip-stick friction and the contact or not of the clutch plates, the system is piecewise linear. Through the stability analysis of the linearized system in clutch slipping phase, the stable condition of the designed parameters is obtained as α>arctan⁡(μc. The mathematical model of the actuation system is validated by prototype testing. And with the validated model, the system dynamics in both stable and unstable conditions is investigated and discussed in engineering side.

  16. Peculiar Designing Features of Control Electromagnet Clutch Drives

    Directory of Open Access Journals (Sweden)

    Yu. M. Zakharik

    2005-01-01

    Full Text Available The paper considers fundamentals of control electromagnet clutch drives. Mathematics dependence of electromagnet armature position is proposed and condition of stable drive operation is determined. Recommendations for selection of drive element characteristics are given in the paper.

  17. Advertisement call and tadpole morphology of the clutch-guarding ...

    African Journals Online (AJOL)

    Advertisement call and tadpole morphology of the clutch-guarding frog Mantidactylus argenteus from eastern ... We provide the first descriptions of the tadpole and advertisement call of Mantidactylus argenteus. ... AJOL African Journals Online.

  18. Asbestos exposures of mechanics performing clutch service on motor vehicles.

    Science.gov (United States)

    Cohen, Howard J; Van Orden, Drew R

    2008-03-01

    A study was conducted to assess historical asbestos exposures of mechanics performing clutch service on motor vehicles. For most of the 20th century, friction components used in brakes and manual transmission clutches contained approximately 25-60% chrysotile asbestos. Since the late 1960s, asbestos exposure assessment studies conducted on mechanics performing brake service have frequently reported levels below the current OSHA permissible exposure limit (PEL) of 0.1 fiber/cc (flcc). Although there is a robust asbestos exposure data set for mechanics performing brake service, there are almost no data for mechanics removing and replacing clutches in manual transmission vehicles. Personal and area airborne asbestos samples were collected during the removal of asbestos-containing clutches from 15 manual transmissions obtained from salvage facilities by an experienced mechanic. Clutch plates and debris were analyzed for asbestos using EPA and ISO published analytical methods. More than 100 personal and area air samples were collected and analyzed for asbestos fibers using NIOSH methods 7400 and 7402. A separate study involved a telephone survey of 16 automotive mechanics who began work prior to 1975. The mechanics were asked about the duration, frequency, and methods used to perform clutch service. Wear debris in the bell housing surrounding clutches had an average of 0.1% chrysotile asbestos by weight, a value consistent with similar reports of brake debris. Asbestos air sampling data collected averaged 0.047 flcc. Mechanics participating in the telephone survey indicated that clutch service was performed infrequently, the entire clutch assembly was normally replaced, and there was no need to otherwise handle the asbestos-containing clutch plates. These mechanics also confirmed that wet methods were most frequently used to clean debris from the bell housing. Combining the asbestos exposure that occurred when mechanics performed clutch service, along with the duration

  19. Thermo-mechanical analysis of the pressure plate of clutch

    Directory of Open Access Journals (Sweden)

    P.V.N. Venkata Mallikarjuna

    2017-09-01

    Full Text Available High Temperature appears in the contact surfaces of a clutch system (friction surface and pressure plate due to the relative motion between these parts during the sliding period. These high temperatures are responsible for several failures such as pressure plate crack, pressure plate warpage etc. With the help of Finite element analysis, the sliding friction process of the pressure plate and friction during clutch engagement is simulated to get temperature field characteristics and contact pressure of pressure plate.

  20. Research and Implementation of Tractor Power Shift Clutch Control System

    OpenAIRE

    Li Chengjun; Ke Meicong; Wu Youyu

    2018-01-01

    Applying power shift control technology on tractor can improve the power, economy and driving comfort of tractor. The separation and engagement control of clutch in tractor power shift transmission system is the key factor to optimize the quality of shift. Through many experiments and tests, an electronic control unit based on MC9S12 was developed, and an effective clutch control strategy was put forward, which improved the jerk of power shift and shortened the gear shift time.

  1. Method and apparatus for operating a powertrain system upon detecting a stuck-closed clutch

    Science.gov (United States)

    Hansen, R. Anthony

    2014-02-18

    A powertrain system includes a multi-mode transmission having a plurality of torque machines. A method for controlling the powertrain system includes identifying all presently applied clutches including commanded applied clutches and the stuck-closed clutch upon detecting one of the torque-transfer clutches is in a stuck-closed condition. A closed-loop control system is employed to control operation of the multi-mode transmission accounting for all the presently applied clutches.

  2. Shift concept for starting clutch in powershift transmission; Schaltkonzept fuer Anfahrkupplungen in Lastschaltgetrieben

    Energy Technology Data Exchange (ETDEWEB)

    Grad, Karl; Cappellaro, Thomas [ZF Friedrichshafen AG, Passau (Germany); Oberbuchner, Thomas

    2013-07-15

    In powershift transmissions for tractors the starting clutch represents a core assembly, which is subjected to the highest stresses in use. ZF Friedrichshafen introduces a design in which the thermal stress on the starting clutches can be significantly reduced by changing the clutch actuation. This enables the starting clutches to be dimensioned substantially lighter or to save more space or their function can even be integrated into the powershift clutches.

  3. Simulation model of an electrohydraulic-actuated double-clutch transmission vehicle: modelling and system design

    Science.gov (United States)

    Schoeftner, J.; Ebner, W.

    2017-12-01

    Automated and manual transmissions are the main link between engine and powertrain. The technical term when the transmission provides the desired torque during all possible driving conditions is denoted as powertrain matching. Recent developments in the last years show that double-clutch-transmissions (DCTs) are a reasonable compromise in terms of production costs, shifting quality, drivability and fuel efficiency. They have several advantages compared to other automatic transmissions (AT). Most DCTs nowadays consist of a hydraulic actuation control unit, which controls the clutches of the gearbox in order to induce a desired drivetrain torque into the driveline. The main functions of hydraulic systems are manifold: they initiate gear shifts, they provide sufficient oil for lubrication and they control the shift quality by suitably providing a desired oil flow or pressure for the clutch actuation. In this paper, a mathematical model of a passenger car equipped with a DCT is presented. The objective of this contribution is to get an increased understanding for the dynamics of the hydraulic circuit and its coupling to the vehicle drivetrain. The simulation model consists of a hydraulic and a mechanical domain: the hydraulic actuation circuit is described by nonlinear differential equations and includes the dynamics of the line pressure and the proportional valve, as well as the influence of the pressure reducing valve, pipe resistances and accumulator dynamics. The drivetrain with its gear ratios, moments of inertia, torsional stiffness of the rotating shafts and a simple longitudinal vehicle model represent the mechanical domain. The link between hydraulic and mechanical domain is given by the clutch, which combines hydraulic equations and Newton's laws. The presented mathematical model may not only be used as a simulation model for developing the transmission control software, it may also serve as a virtual layout for the design process phase. At the end of this

  4. Remifentanil maintains lower initial delayed nonmatching-to-sample accuracy compared to food pellets in male rhesus monkeys.

    Science.gov (United States)

    Hutsell, Blake A; Banks, Matthew L

    2017-12-01

    Emerging human laboratory and preclinical drug self-administration data suggest that a history of contingent abused drug exposure impairs performance in operant discrimination procedures, such as delayed nonmatching-to-sample (DNMTS), that are hypothesized to assess components of executive function. However, these preclinical discrimination studies have exclusively used food as the reinforcer and the effects of drugs as reinforcers in these operant procedures are unknown. The present study determined effects of contingent intravenous remifentanil injections on DNMTS performance hypothesized to assess 1 aspect of executive function, working memory. Daily behavioral sessions consisted of 2 components with sequential intravenous remifentanil (0, 0.01-1.0 μg/kg/injection) or food (0, 1-10 pellets) availability in nonopioid dependent male rhesus monkeys (n = 3). Remifentanil functioned as a reinforcer in the DNMTS procedure. Similar delay-dependent DNMTS accuracy was observed under both remifentanil- and food-maintained components, such that higher accuracies were maintained at shorter (0.1-1.0 s) delays and lower accuracies approaching chance performance were maintained at longer (10-32 s) delays. Remifentanil maintained significantly lower initial DNMTS accuracy compared to food. Reinforcer magnitude was not an important determinant of DNMTS accuracy for either remifentanil or food. These results extend the range of experimental procedures under which drugs function as reinforcers. Furthermore, the selective remifentanil-induced decrease in initial DNMTS accuracy is consistent with a selective impairment of attentional, but not memorial, processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Nest predation risk explains variation in avian clutch size

    Science.gov (United States)

    Dillon, Kristen G.; Conway, Courtney J.

    2018-01-01

    Questions about the ecological drivers of, and mechanistic constraints on, productivity have driven research on life-history evolution for decades. Resource availability and offspring mortality are considered among the 2 most important influences on the number of offspring per reproductive attempt. We used a factorial experimental design to manipulate food abundance and perceived offspring predation risk in a wild avian population (red-faced warblers; Cardellina rubrifrons) to identify the mechanistic cause of variation in avian clutch size. Additionally, we tested whether female quality helped explain the extant variation in clutch size. We found no support for the Food Limitation or Female Quality Hypotheses, but we did find support for both predictions of the Nest Predation Risk Hypothesis. Females that experienced an experimentally heightened perception of offspring predation risk responded by laying a smaller clutch than females in the control group. Additionally, predation rates at artificial nests were highest where red-faced warbler clutch size was smallest (at high elevations). Life-history theory predicts that an individual should invest less in reproduction when high nest predation risk reduces the likely benefit from that nesting attempt and, indeed, we found that birds exhibit phenotypic plasticity in clutch size by laying fewer eggs in response to increasing nest predation risk.

  6. Outcomes of Neonatal Candidiasis: The Impact of Delayed Initiation of Antifungal Therapy

    Directory of Open Access Journals (Sweden)

    Heather Cahan

    2011-01-01

    Results. Sixty-three newborns with invasive neonatal candidiasis were identified. Overall mortality rate was 35%. Virtually every infant had a central venous catheter (CVC, required mechanical ventilation and previous administration of antibacterial agents. Delayed institution of antifungal therapy was associated with increased mortality. In addition, length of hospitalization, duration of prior antibacterial therapy, mechanical ventilation, and CVC use, as well as evidence of end-organ disease, were associated with an adverse outcome. Conclusions. Reliance on available laboratory tools in cases of invasive neonatal candidiasis can result in delayed diagnosis and increased mortality. A risk-factor-based approach to empirical treatment could be justified in this setting.

  7. A novel ultrasonic clutch using near-field acoustic levitation.

    Science.gov (United States)

    Chang, Kuo-Tsi

    2004-10-01

    This paper investigates design, fabrication and drive of an ultrasonic clutch with two transducers. For the two transducers, one serving as a driving element of the clutch is connected to a driving shaft via a coupling, and the other serving as a slave element of the clutch is connected to a slave shaft via another coupling. The principle of ultrasonic levitation is first expressed. Then, a series-resonant inverter is used to generate AC voltages at input terminals of each transducer, and a speed measuring system with optic sensors is used to find the relationship between rotational speed of the slave shaft and applied voltage of each transducer. Moreover, contact surfaces of the two transducers are coupled by the frictional force when both the two transducers are not energized, and separated using the ultrasonic levitation when at least one of the two transducers is energized at high voltages at resonance.

  8. Ergonomic assessment of drivers in MF285 and MF399 tractors during clutching using algometer

    Directory of Open Access Journals (Sweden)

    Hossein Fallahi

    2016-03-01

    The results showed that the clutching forces for MF285 and MF399 tractors were 340 N and 290 N, respectively. The knee angle of the drivers of the two tractors was statistically different at the one percent level of significance. The reduction of pain threshold after 30 and 60 s clutching and also 60 s rest after clutching in MF285 tractor, for all three muscles, were more than those of MF399 tractor. The impact of clutching on the average decreases of pain threshold, for all drivers and all clutching periods, during and after clutching, in the Quadratus lumborum muscle was more than the other two muscles, in both tractors. In order to reduce the clutching force for MF285 tractor some modifications is suggested. In this regard the force transfer joint between the pedal and the clutch release linkage may be replaced with one made of cast iron.

  9. Switched causual modeling of transmission with clutch in hybrid electric vehicles

    OpenAIRE

    LHOMME, W; TRIGUI, R; DELARU, P; JEANNERET, B; BOUSCAUROL, A; BADIN, F

    2008-01-01

    Certain difficulties arise when attempting to model a clutch in a power train transmission due to its nonlinear behavior. Two different states have to be taken into account-the first being when the clutch is locked and the second being when the clutch is slipping. In this paper, a clutch model is developed using the Energetic Macroscopic Representation, which is, in turn, used in the modeling of complete hybrid electric vehicles (HEVs). Two different models are used, and a specific condition ...

  10. Early versus delayed initiation of antiretroviral therapy for Indian HIV-Infected individuals with tuberculosis on antituberculosis treatment.

    Science.gov (United States)

    Sinha, Sanjeev; Shekhar, Rahul C; Singh, Gurjeet; Shah, Nipam; Ahmad, Hafiz; Kumar, Narendra; Sharma, Surendra K; Samantaray, J C; Ranjan, Sanjai; Ekka, Meera; Sreenivas, Vishnu; Mitsuyasu, Ronald T

    2012-07-31

    For antiretroviral therapy (ART) naive human immunodeficiency virus (HIV) infected adults suffering from tuberculosis (TB), there is uncertainty about the optimal time to initiate highly active antiretroviral therapy (HAART) after starting antituberculosis treatment (ATT), in order to minimize mortality, HIV disease progression, and adverse events. In a randomized, open label trial at All India Institute of Medical Sciences, New Delhi, India, eligible HIV positive individuals with a diagnosis of TB were randomly assigned to receive HAART after 2-4 or 8-12 weeks of starting ATT, and were followed for 12 months after HAART initiation. Participants received directly observed therapy short course (DOTS) for TB, and an antiretroviral regimen comprising stavudine or zidovudine, lamivudine, and efavirenz. Primary end points were death from any cause, and progression of HIV disease marked by failure of ART. A total of 150 patients with HIV and TB were initiated on HAART: 88 received it after 2-4 weeks (early ART) and 62 after 8-12 weeks (delayed ART) of starting ATT. There was no significant difference in mortality between the groups after the introduction of HAART. However, incidence of ART failure was 31% in delayed versus 16% in early ART arm (p = 0.045). Kaplan Meier disease progression free survival at 12 months was 79% for early versus 64% for the delayed ART arm (p = 0.05). Rates of adverse events were similar. Early initiation of HAART for patients with HIV and TB significantly decreases incidence of HIV disease progression and has good tolerability. CTRI/2011/12/002260.

  11. Early versus delayed initiation of antiretroviral therapy for Indian HIV-Infected individuals with tuberculosis on antituberculosis treatment

    Directory of Open Access Journals (Sweden)

    Sinha Sanjeev

    2012-07-01

    Full Text Available Abstract Background For antiretroviral therapy (ART naive human immunodeficiency virus (HIV infected adults suffering from tuberculosis (TB, there is uncertainty about the optimal time to initiate highly active antiretroviral therapy (HAART after starting antituberculosis treatment (ATT, in order to minimize mortality, HIV disease progression, and adverse events. Methods In a randomized, open label trial at All India Institute of Medical Sciences, New Delhi, India, eligible HIV positive individuals with a diagnosis of TB were randomly assigned to receive HAART after 2-4 or 8-12 weeks of starting ATT, and were followed for 12 months after HAART initiation. Participants received directly observed therapy short course (DOTS for TB, and an antiretroviral regimen comprising stavudine or zidovudine, lamivudine, and efavirenz. Primary end points were death from any cause, and progression of HIV disease marked by failure of ART. Findings A total of 150 patients with HIV and TB were initiated on HAART: 88 received it after 2-4 weeks (early ART and 62 after 8-12 weeks (delayed ART of starting ATT. There was no significant difference in mortality between the groups after the introduction of HAART. However, incidence of ART failure was 31% in delayed versus 16% in early ART arm (p = 0.045. Kaplan Meier disease progression free survival at 12 months was 79% for early versus 64% for the delayed ART arm (p = 0.05. Rates of adverse events were similar. Interpretation Early initiation of HAART for patients with HIV and TB significantly decreases incidence of HIV disease progression and has good tolerability. Trial registration CTRI/2011/12/002260

  12. Strong but variable associations between social dominance and clutch sex ratio in a colonial corvid

    NARCIS (Netherlands)

    Salomons, H. M.; Dijkstra, C.; Verhulst, S.

    2008-01-01

    We studied primary sex ratio of clutches in relation to social dominance for 6 years in a colony of free-living jackdaws, a small corvid. Social dominance was strongly associated with clutch sex ratio, with the difference in clutch sex ratio between the most and least dominant pairs being 30-40%. To

  13. Fitness cost of incubation in great tits (Parus major) is related to clutch size

    Science.gov (United States)

    de Heij, Maaike E; van den Hout, Piet J; Tinbergen, Joost M

    2006-01-01

    Life-history theory predicts that parents produce the number of offspring that maximizes their fitness. In birds, natural selection on parental decisions regarding clutch size may act during egg laying, incubation or nestling phase. To study the fitness consequences of clutch size during the incubation phase, we manipulated the clutch sizes during this phase only in three breeding seasons and measured the fitness consequences on the short and the long term. Clutch enlargement did not affect the offspring fitness of the manipulated first clutches, but fledging probability of the subsequent clutch in the same season was reduced. Parents incubating enlarged first clutches provided adequate care for the offspring of their first clutches during the nestling phase, but paid the price when caring for the offspring of their second clutch. Parents that incubated enlarged first clutches had lower local survival in the 2 years when the population had a relatively high production of second clutches, but not in the third year when there was a very low production of second clutches. During these 2 years, the costs of incubation were strong enough to change positive selection, as established by brood size manipulations in this study population, into stabilizing selection through the negative effect of incubation on parental fitness. PMID:16928638

  14. note on variable incubation period within a clutch of eggs

    African Journals Online (AJOL)

    Compo Biochem. Physiol. 53A: 1-6. MENDELSOHN, 1. M., BIGOS, H. C. & LEDGER, 1. A. In press. The biology of the black-shouldered. NOTE ON VARIABLE. INCUBATION PERIOD WITHIN A. CLUTCH OF EGGS OF THE. LEOPARD TORTOISE. (GEOCHELONE P ARDALIS). (CHELONIA: CRYPTODIRA: TESTUDINIDAE).

  15. A conceptual framework for clutch size evolution in songbirds

    Science.gov (United States)

    Martin, Thomas E.

    2014-01-01

    Causes of evolved differences in clutch size among songbird species remain debated. I propose a new conceptual framework that integrates aspects of traditional life history theory, while including novel elements, to explain evolution of clutch size among songbirds. I review evidence that selection by nest predation on length of time that offspring develop in the nest creates a gradient in offspring characteristics at nest-leaving (fledging), including flight mobility, spatial dispersion, and self-feeding rate. I postulate that this gradient has consequences for offspring mortality rates and parental energy expenditure per offspring. These consequences then determine how reproductive effort is partitioned among offspring, while reproductive effort evolves from age-specific mortality effects. Using data from a long-term site in Arizona, as well as from the literature, I provide support for hypothesized relationships. Nestling development period consistently explains fledgling mortality, energy expenditure per offspring, and clutch size while accounting for reproductive effort (i.e., total energy expenditure) to thereby support the framework. Tests in this paper are not definitive, but they document previously unrecognized relationships and address diverse traits (developmental strategies, parental care strategies, energy requirements per offspring, evolution of reproductive effort, clutch size) that justify further investigations of hypotheses proposed here.

  16. Diapause in Calanoid Copepods: within-clutch hatching patterns

    Directory of Open Access Journals (Sweden)

    Bart T. DE STASIO

    2004-09-01

    Full Text Available Diapause is a major life history feature of many invertebrate organisms. Determining the phenology of diapause is critical for understanding survival and reproductive success of individuals as well as the long-term viability of many populations. The time spent in dormancy by individuals and variability among offspring in the duration of dormancy are two important aspects of invertebrate life histories. Some data are available, especially on duration of diapause, for plants and insects, but little information is available concerning variability among offspring in diapause traits. This is especially true for crustacean zooplankton, where essentially no information has been published on duration of diapause or variability among offspring in diapause timing or dynamics. Here I present data on the duration of diapause, and variability among offspring for diapause characteristics. The freshwater calanoid copepod Onychodiaptomus sanguineus, an obligately sexual species, was collected from Bullhead Pond, Rhode Island, U.S.A., and raised under conditions in the laboratory to induce production of diapausing eggs. One hundred clutches of these diapausing eggs (920 total eggs were incubated for over two years in a full-factorial experiment testing the effects of temperature and photoperiod cycles on the hatching dynamics and duration of diapause. Overall hatching success was highest (approximately 86% for eggs exposed to simultaneous temperature and photoperiod cycles mimicking natural changes, and was lowest (approximately 20% when eggs were incubated at constant temperature (4 °C and in constant dark conditions. The highest fraction of eggs hatched at approximately 550 days of age, but the age of eggs at hatching was highly variable among clutches. There was also large variability within clutches for hatching patterns, with some clutches containing eggs that all hatched synchronously and others in which eggs hatched more continuously throughout the

  17. AMPK agonist AICAR delays the initial decline in lifetime-apex V̇o2 peak, while voluntary wheel running fails to delay its initial decline in female rats.

    Science.gov (United States)

    Toedebusch, Ryan G; Ruegsegger, Gregory N; Braselton, Joshua F; Heese, Alexander J; Hofheins, John C; Childs, Tom E; Thyfault, John P; Booth, Frank W

    2016-02-01

    There has never been an outcome measure for human health more important than peak oxygen consumption (V̇o2 peak), yet little is known regarding the molecular triggers for its lifetime decline with aging. We examined the ability of physical activity or 5 wk of 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) administration to delay the initial aging-induced decline in lifetime-apex V̇o2 peak and potential underlying molecular mechanisms. Experiment 1 consisted of female rats with (RUN) and without (NO RUN) running wheels, while experiment 2 consisted of female nonrunning rats getting the AMPK agonist AICAR (0.5 mg/g/day) subcutaneously for 5 wk beginning at 17 wk of age. All rats underwent frequent, weekly or biweekly V̇o2 peak tests beginning at 10 wk of age. In experiment 1, lifetime-apex V̇o2 peak occurred at 19 wk of age in both RUN and NO RUN and decreased thereafter. V̇o2 peak measured across experiment 1 was ∼25% higher in RUN than in NO RUN. In experiment 2, AICAR delayed the chronological age observed in experiment 1 by 1 wk, from 19 wk to 20 wk of age. RUN and NO RUN showed different skeletal muscle transcriptomic profiles both pre- and postapex. Additionally, growth and development pathways are differentially regulated between RUN and NO RUN. Angiomotin mRNA was downregulated postapex in RUN and NO RUN. Furthermore, strong significant correlations to V̇o2 peak and trends for decreased protein concentration supports angiomotin's potential importance in our model. Contrary to our primary hypothesis, wheel running was not sufficient to delay the chronological age of lifetime-apex V̇o2 peak decline, whereas AICAR delayed it 1 wk. Copyright © 2016 the American Physiological Society.

  18. Larval development of hoplias cf. Lacerdae (Pisces: Erythrinidae and delayed initial feeding effects

    Directory of Open Access Journals (Sweden)

    Rodolfo N. Sirol

    1998-06-01

    Full Text Available Larval development of Hoplias cf. lacerdae was studied under laboratory conditions. After hatching, ontogenetic changes were recorded on food-deprived larvae in 12-hour intervals. Mouth opening occurred after 2.5 days and notochord terminated flexure in 6.5 days. Notochord length increased at a constant rate until complete yolk absorption (13,5 days. Larval dry weight and body height diminished gradually up to 21 days after hatching, when all starved larvae died. Every 12 hours after yolk absorption, groups of larvae (n=15, were separeted, and fed with Artemia nauplii for 10 days. The point-of-no-return (when 50% of larvae were unable to feed or to assimilate ingested food after delayed feeding, was not apparent in this species.

  19. Myocardial delayed contrast enhancement in patients with arterial hypertension: Initial results of cardiac MRI

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Kjel [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: kjel_andersen@web.de; Hennersdorf, Marcus [Department of Cardiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: hennersdorf@med.uni-duesseldorf.de; Cohnen, Mathias [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: cohnen@med.uni-duesseldorf.de; Blondin, Dirk [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: blondin@med.uni-duesseldorf.de; Moedder, Ulrich [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: moedder@uni-duesseldorf.de; Poll, Ludger W. [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: poll@gmx.de

    2009-07-15

    Purpose: In arterial hypertension left ventricular hypertrophy comprises myocyte hypertrophy, interstitial fibrosis and structural alterations of the coronary microcirculation. MRI enables the detection of myocardial fibrosis, infarction and scar tissue by delayed enhancement (DE) after contrast media application. Aim of this study was to investigate patients with arterial hypertension but without known coronary disease or previous myocardial infarction to detect areas of DE. Methods and material: Twenty patients with arterial hypertension with clinical symptoms of myocardial ischemia, but without history of myocardial infarction and normal coronary arteries during coronary angiography were investigated on a 1.0 T superconducting magnet (Gyroscan T10-NT, Intera Release 8.0, Philips). Fast gradient-echo cine sequences and T2-weighted STIR-sequences were acquired. Fifteen minutes after injection of Gadobenate dimeglumine inversion recovery gradient-echo sequences were performed for detection of myocardial DE. Presence or absence of DE on MRI was correlated with clinical data and the results of echocardiography and electrocardiography, respectively. Results: Nine of 20 patients showed DE in the interventricular septum and the anteroseptal left ventricular wall. In 6 patients, DE was localized intramurally and in 3 patients subendocardially. There was a significant correlation between myocardial DE and ST-segment depressions during exercise and between DE and left-ventricular enddiastolic pressure. Patients with intermittent atrial fibrillation showed a myocardial DE more often than patients without atrial fibrillation. Conclusion: In our series, 45% of patients with arterial hypertension showed DE on cardiac MRI. In this clinical setting, delayed enhancement may be due to coronary microangiopathy. The more intramurally localization of DE, however, rather indicates myocardial interstitial fibrosis.

  20. Myocardial delayed contrast enhancement in patients with arterial hypertension: Initial results of cardiac MRI

    International Nuclear Information System (INIS)

    Andersen, Kjel; Hennersdorf, Marcus; Cohnen, Mathias; Blondin, Dirk; Moedder, Ulrich; Poll, Ludger W.

    2009-01-01

    Purpose: In arterial hypertension left ventricular hypertrophy comprises myocyte hypertrophy, interstitial fibrosis and structural alterations of the coronary microcirculation. MRI enables the detection of myocardial fibrosis, infarction and scar tissue by delayed enhancement (DE) after contrast media application. Aim of this study was to investigate patients with arterial hypertension but without known coronary disease or previous myocardial infarction to detect areas of DE. Methods and material: Twenty patients with arterial hypertension with clinical symptoms of myocardial ischemia, but without history of myocardial infarction and normal coronary arteries during coronary angiography were investigated on a 1.0 T superconducting magnet (Gyroscan T10-NT, Intera Release 8.0, Philips). Fast gradient-echo cine sequences and T2-weighted STIR-sequences were acquired. Fifteen minutes after injection of Gadobenate dimeglumine inversion recovery gradient-echo sequences were performed for detection of myocardial DE. Presence or absence of DE on MRI was correlated with clinical data and the results of echocardiography and electrocardiography, respectively. Results: Nine of 20 patients showed DE in the interventricular septum and the anteroseptal left ventricular wall. In 6 patients, DE was localized intramurally and in 3 patients subendocardially. There was a significant correlation between myocardial DE and ST-segment depressions during exercise and between DE and left-ventricular enddiastolic pressure. Patients with intermittent atrial fibrillation showed a myocardial DE more often than patients without atrial fibrillation. Conclusion: In our series, 45% of patients with arterial hypertension showed DE on cardiac MRI. In this clinical setting, delayed enhancement may be due to coronary microangiopathy. The more intramurally localization of DE, however, rather indicates myocardial interstitial fibrosis.

  1. Differences in size between first and replacement clutches match the seasonal decline in single clutches in Tree Swallows

    NARCIS (Netherlands)

    Karagicheva, J.; Liebers, M.; Rakhimberdiev, E.; Hallinger, K.; Saveliev, A.; Winkler, D.W.

    2016-01-01

    The seasonal decline in clutch size in birds can be a response to the environmentallyconditioned decrease in prospects for offspring or a consequence of a lower physical abilityof late-breeding females. To find out which of the explanations apply in Tree SwallowsTachycineta bicolor, we assessed

  2. Learning From Tests: Facilitation of Delayed Recall by Initial Recognition Alternatives.

    Science.gov (United States)

    Whitten, William B., II; Leonard, Janet Mauriello

    1980-01-01

    Two experiments were designed to determine the effects of multiple-choice recognition test alternatives on subsequent memory for the correct answers. Results of both experiments are interpreted as demonstrations of the principle that long-term retention is facilitated such that memory evaluation occurs during initial recognition tests. (Author/RD)

  3. The differences in delay times for air showers initiated by 100 TeV gamma rays and protons

    International Nuclear Information System (INIS)

    Mikocki, S.; Poirier, J.; Linsley, J.; Consiglio Nazionale delle Ricerche, Palermo; Wrotniak, A.; Maryland Univ., College Park

    1987-01-01

    The purpose of this study is to investigate whether there are any differences in the time delay distributions between showers initiated by gamma rays and by protons. The results of Monte Carlo calculations of atmospheric showers initiated by gamma rays and protons at an energy of 100 TeV show systematic differences. These differences are negligible at small distances from the core of the showers; at larger distances the effects become large. However, at large distances the particle densities are small at an energy of 100 TeV and the subsequent statistical fluctuations would make an identification of gamma-ray showers unreliable. However, these large effects should be included in corrections for the curvature of gamma-ray and proton shower fronts. (author)

  4. The Evolution of Clutch Size in Hosts of Avian Brood Parasites.

    Science.gov (United States)

    Medina, Iliana; Langmore, Naomi E; Lanfear, Robert; Kokko, Hanna

    2017-11-01

    Coevolution with avian brood parasites shapes a range of traits in their hosts, including morphology, behavior, and breeding systems. Here we explore whether brood parasitism is also associated with the evolution of host clutch size. Several studies have proposed that hosts of highly virulent parasites could decrease the costs of parasitism by evolving a smaller clutch size, because hosts with smaller clutches will lose fewer progeny when their clutch is parasitized. We describe a model of the evolution of clutch size, which challenges this logic and shows instead that an increase in clutch size (or no change) should evolve in hosts. We test this prediction using a broad-scale comparative analysis to ask whether there are differences in clutch size within hosts and between hosts and nonhosts. Consistent with our model, this analysis revealed that host species do not have smaller clutches and that hosts that incur larger costs from raising a parasite lay larger clutches. We suggest that brood parasitism might be an influential factor in clutch-size evolution and could potentially select for the evolution of larger clutches in host species.

  5. Is there an association between suicide attempt and delay of initiation of mood stabilizers in bipolar I disorder?

    Science.gov (United States)

    Nery-Fernandes, Fabiana; Quarantini, Lucas C; Guimarães, José L; de Oliveira, Irismar R; Koenen, Karestan C; Kapczinski, Flavio; Miranda-Scippa, Ângela

    2012-02-01

    Little is known about the extent to which delay of initiation of mood-stabilizing treatment may influence outcomes in bipolar patients (BP). In this study, our aim was to investigate the association between delay of mood stabilizer treatment in bipolar patients and lifetime history of suicide attempts. A consecutive sample of 268 bipolar I outpatients from two teaching hospitals in Brazil was recruited. The assessment included a socio-demographic history form, a clinical interview regarding clinical variables and the Structured Clinical Interview for DSM-IV. Participants were divided into three groups: BP that initiated the first mood stabilizer in the same year of the first episode of the disease (FMS≤1), between 1 and 5 years after the first episode of the disease (15). The mean time from the first episode until the first mood stabilizer medication was 8.6 years (SD 9.8 years). The FMS>5 group, showed a higher lifetime prevalence of suicide attempts than the other two groups (PR=1.75, 95% CI: 1.24-2.47), p=0.001. These results remained significant after adjusting for potential confounders, (PR=1.82, 95% CI: 1.29-2.60), p=0.001. This study evaluated patients retrospectively and does not permit a cause-effect relationship. The present study supports the importance of early diagnosis and early intervention for BP in order to limit the potentially lethal impact of the disease. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. A new method for speed control of a DC motor using magnetorheological clutch

    Science.gov (United States)

    Nguyen, Quoc Hung; Choi, Seung-Bok

    2014-03-01

    In this research, a new method to control speed of DC motor using magnetorheological (MR) clutch is proposed and realized. Firstly, the strategy of a DC motor speed control using MR clutch is proposed. The MR clutch configuration is then proposed and analyzed based on Bingham-plastic rheological model of MR fluid. An optimal designed of the MR clutch is then studied to find out the optimal geometric dimensions of the clutch that can transform a required torque with minimum mass. A prototype of the optimized MR clutch is then manufactured and its performance characteristics are experimentally investigated. A DC motor speed control system featuring the optimized MR clutch is designed and manufactured. A PID controller is then designed to control the output speed of the system. In order to evaluate the effectiveness of the proposed DC motor speed control system, experimental results of the system such as speed tracking performance are obtained and presented with discussions.

  7. Experimental warming delays autumn senescence in a boreal spruce bog: Initial results from the SPRUCE experiment

    Science.gov (United States)

    Richardson, Andrew; Furze, Morgan; Aubrecht, Donald; Milliman, Thomas; Nettles, Robert; Krassovski, Misha; Hanson, Paul

    2016-04-01

    Phenology is considered one of the most robust indicators of the biological impacts of global change. In temperate and boreal regions, long-term data show that rising temperatures are advancing spring onset (e.g. budburst and flowering) and delaying autumn senescence (e.g. leaf coloration and leaf fall) in a wide range of ecosystems. While warm and cold temperatures, day length and insolation, precipitation and water availability, and other factors, have all been shown to influence plant phenology, the future response of phenology to rising temperatures and elevated CO2 still remains highly uncertain because of the challenges associated with conducting realistic manipulative experiments to simulate future environmental conditions. At the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) experiment in the north-central United States, experimental temperature (0 to +9° C above ambient) and CO2 (ambient and elevated) treatments are being applied to mature, and intact, Picea mariana-Sphagnum spp. bog communities in their native habitat through the use of ten large (approximately 12 m wide, 10 m high) open-topped enclosures. We are tracking vegetation green-up and senescence in these chambers, at both the individual and whole-community level, using repeat digital photography. Within each chamber, digital camera images are recorded every 30 minutes and uploaded to the PhenoCam (http://phenocam.sr.unh.edu) project web page, where they are displayed in near-real-time. Image processing is conducted nightly to extract quantitative measures of canopy color, which we characterize using Gcc, the green chromatic coordinate. Data from a camera mounted outside the chambers (since November 2014) indicate strong seasonal variation in Gcc for both evergreen shrubs and trees. Shrub Gcc rises steeply in May and June, and declines steeply in September and October. By comparison, tree Gcc rises gradually from March through June, and declines gradually from

  8. Initial Misdiagnosis of Proximal Pancreatic Adenocarcinoma Is Associated with Delay in Diagnosis and Advanced Stage at Presentation.

    Science.gov (United States)

    Swords, Douglas S; Mone, Mary C; Zhang, Chong; Presson, Angela P; Mulvihill, Sean J; Scaife, Courtney L

    2015-10-01

    Delay in diagnosis of pancreatic ductal adenocarcinoma (PDAC) is associated with decreased survival. The effect of an initial misdiagnosis on delay in diagnosis and stage of PDAC is unknown. This study is a retrospective review (2000-2010) from a University-based cancer center of new diagnoses of proximal PDAC. Of 313 patients, 98 (31.3 %) had an initial misdiagnosis. Misdiagnosed patients were younger, 62.8 ± 12.6 vs. 68.0 ± 10.1 (p < 0.001). The most common initial misdiagnoses were: gallbladder disease, gastroesophageal reflux disease, and peptic ulcer disease. After excluding patients with prior cholecystectomy, 14.2 % were misdiagnosed with gallbladder disease and underwent cholecystectomy before PDAC diagnosis. Misdiagnosed patients had higher rates of abdominal pain (p < 0.001), weight loss (p = 0.04), and acute pancreatitis (p < 0.001) and lower rate of jaundice (p < 0.001). Median time between symptoms to PDAC diagnosis was longer in misdiagnosed: 4.2 months vs. 1.4 (p < 0.001). Median time from contact with medical provider to axial imaging was longer in misdiagnosed (p < 0.001). Rate of stages III-IV disease at diagnosis was higher in misdiagnosed: 61.2 vs. 43.7 % (p = 0.004), with a 1.4 (95 % confidence interval (CI), 1.12-1.74) higher risk of stages III-IV disease at diagnosis; however, there was no difference in median overall survival in misdiagnosed patients (9.6 months in misdiagnosed vs. 10.3 months in correctly diagnosed, p = 0.69). Initial misdiagnosis of patients with proximal PDAC is associated with delay in diagnosis and higher risk of locally advanced or advanced disease at time of PDAC diagnosis.

  9. Extending the molecular clutch beyond actin-based cell motility

    International Nuclear Information System (INIS)

    Havrylenko, Svitlana; Mezanges, Xavier; Batchelder, Ellen; Plastino, Julie

    2014-01-01

    Many cell movements occur via polymerization of the actin cytoskeleton beneath the plasma membrane at the front of the cell, forming a protrusion called a lamellipodium, while myosin contraction squeezes forward the back of the cell. In what is known as the ‘molecular clutch’ description of cell motility, forward movement results from the engagement of the acto-myosin motor with cell-matrix adhesions, thus transmitting force to the substrate and producing movement. However during cell translocation, clutch engagement is not perfect, and as a result, the cytoskeleton slips with respect to the substrate, undergoing backward (retrograde) flow in the direction of the cell body. Retrograde flow is therefore inversely proportional to cell speed and depends on adhesion and acto-myosin dynamics. Here we asked whether the molecular clutch was a general mechanism by measuring motility and retrograde flow for the Caenorhabditis elegans sperm cell in different adhesive conditions. These cells move by adhering to the substrate and emitting a dynamic lamellipodium, but the sperm cell does not contain an acto-myosin cytoskeleton. Instead the lamellipodium is formed by the assembly of major sperm protein, which has no biochemical or structural similarity to actin. We find that these cells display the same molecular clutch characteristics as acto-myosin containing cells. We further show that retrograde flow is produced both by cytoskeletal assembly and contractility in these cells. Overall this study shows that the molecular clutch hypothesis of how polymerization is transduced into motility via adhesions is a general description of cell movement regardless of the composition of the cytoskeleton. (paper)

  10. Delayed initiation of antenatal care and associated factors in Ethiopia: a systematic review and meta-analysis.

    Science.gov (United States)

    Tesfaye, Gezahegn; Loxton, Deborah; Chojenta, Catherine; Semahegn, Agumasie; Smith, Roger

    2017-11-15

    Antenatal care uptake is among the key indicators for monitoring the progress of maternal outcomes. Early initiation of antenatal care facilitates the timely management and treatment of pregnancy complications to reduce maternal deaths. In Ethiopia, antenatal care utilization is generally low, and delayed initiation of care is very common. We aimed to systematically identify and synthesize available evidence on delayed initiation of antenatal care and the associated factors in Ethiopia. Studies published in English from 1 January 2002 to 30 April 2017 were systematically searched from PubMed, Medline, EMBASE, CINAHL and other relevant sources. Two authors independently reviewed the identified studies against the eligibility criteria. The included studies were critically appraised using the Joanna Briggs-MAStARI instrument for observational studies. Meta-analysis was conducted in RevMan v5.3 for Windows using a Mantel-Haenszel random effects model. The presence of statistical heterogeneity was checked using the Cochran Q test, and its level was quantified using the I 2 statistics. Pooled estimate of the proportion of the outcome variable was calculated. Pooled Odd Ratios with 95% CI were calculated to measure the effect sizes. The pooled magnitude of delayed antenatal care in Ethiopia was 64% (95% CI: 57%, 70%). Maternal age (OR = 0.70; 95% CI: 0.53, 0.93), place of residence (OR = 0.29, 95% CI: 0.16, 0.50), maternal education (OR = 0.49; 95% CI: 0.38, 0.63), husband's education (OR = 0.44; 95% CI: 0.23, 0.85), maternal occupation (OR = 0.75; 95% CI: 0.61, 0.93), monthly income (OR = 2.06; 95% CI: 1.23, 3.45), pregnancy intention (OR = 0.49; 95% CI: 0.40, 0.60), parity (OR = 0.46; 95% CI: 0.36, 0.58), knowledge of antenatal care (OR = 0.40; 95% CI: 0.32, 0.51), women's autonomy (OR = 0.38; 95% CI: 0.15, 0.94), partner involvement (OR = 0.24; 95% CI: 0.07, 0.75), pregnancy complications (OR = 0.23; 95% CI: 0.06, 0

  11. Clutch frequency affects the offspring size-number trade-off in lizards.

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2011-01-01

    Full Text Available Studies of lizards have shown that offspring size cannot be altered by manipulating clutch size in species with a high clutch frequency. This raises a question of whether clutch frequency has a key role in influencing the offspring size-number trade-off in lizards.To test the hypothesis that females reproducing more frequently are less likely to tradeoff offspring size against offspring number, we applied the follicle ablation technique to female Eremias argus (Lacertidae from Handan (HD and Gonghe (GH, the two populations that differ in clutch frequency. Follicle ablation resulted in enlargement of egg size in GH females, but not in HD females. GH females switched from producing a larger number of smaller eggs in the first clutch to a smaller number of larger eggs in the second clutch; HD females showed a similar pattern of seasonal shifts in egg size, but kept clutch size constant between the first two clutches. Thus, the egg size-number trade-off was evident in GH females, but not in HD females.As HD females (mean  = 3.1 clutches per year reproduce more frequently than do GH females (mean  = 1.6 clutches per year, our data therefore validate the hypothesis tested. Our data also provide an inference that maximization of maternal fitness could be achieved in females by diverting a large enough, rather than a higher-than-usual, fraction of the available energy to individual offspring in a given reproductive episode.

  12. Random start ovarian stimulation for fertility preservation appears unlikely to delay initiation of neoadjuvant chemotherapy for breast cancer.

    Science.gov (United States)

    Letourneau, Joseph M; Sinha, Nikita; Wald, Kaitlyn; Harris, Eve; Quinn, Molly; Imbar, Tal; Mok-Lin, Evelyn; Chien, A Jo; Rosen, Mitchell

    2017-10-01

    Is random start ovarian stimulation associated with delays in initiation of neoadjuvant chemotherapy for breast cancer? Among women who complete fertility preservation (FP) consultation, random start ovarian stimulation is unlikely to delay time to initiation of neoadjuvant chemotherapy start. Neoadjuvant chemotherapy is now a widely accepted treatment modality for operable breast cancer and random start ovarian stimulation is an increasingly-utilized modality for FP. While conventional ovarian stimulation does not appear to delay starting adjuvant chemotherapy, the relationship between random start ovarian stimulation and neoadjuvant chemotherapy start is not well-understood. Cross-sectional study of all women seen between from January 2011 to April 2017 for FP consultation prior to starting neoadjuvant chemotherapy for breast cancer. A chart-review was performed. Study inclusion criteria were female sex; age 18-45; non-metastatic breast cancer diagnosis; underwent FP consultation; underwent neoadjuvant chemotherapy. Referrals for FP evaluation came from a regional referral base of oncology clinics. Various time-points related to cancer diagnosis, FP or chemotherapy were obtained from medical record review. We compared time-points between those who underwent ovarian stimulation for FP versus those who did not using T-tests and linear modeling. A total of 89 women who had FP consultation prior to neoadjuvant chemotherapy were identified. Sixty-seven percent underwent ovarian stimulation prior to cancer treatment and 33% did not. Women who underwent ovarian stimulation were similar in parity and clinical cancer stage to those who did not. Overall, the average time from cancer diagnosis to chemotherapy start was similar between the group that did undergo ovarian stimulation and those who did not (38.1 ± 11.3 versus 39.4 ± 18.5 days, P = 0.672). Those that underwent ovarian stimulation were referred 9.4 ± 6.8 days after diagnosis versus 17.9 ± 15.3 days for those

  13. Mortality associated with delays between clinic entry and ART initiation in resource-limited-settings: results of a transition-state model

    Science.gov (United States)

    HOFFMANN, Christopher J; LEWIS, James J; DOWDY, David W; FIELDING, Katherine L; GRANT, Alison D; MARTINSON, Neil A; CHURCHYARD, Gavin J; CHAISSON, Richard E

    2013-01-01

    Objective Estimate the mortality impact of delay in antiretroviral therapy (ART) initiation from the time of entry-into-care. Design A state-transition Markov process model. This technique allows for assessing mortality before and after ART initiation associated with delays in ART initiation among a general population of ART eligible patients without conducting a randomized trial. Methods We used patient-level data from three South African cohorts to determine transition probabilities for pre-ART CD4 count changes and pre-ART and on-ART mortality. For each parameter we generated probabilities and distributions for Monte Carlo simulations with one week cycles to estimate mortality 52 weeks from clinic entry. Results We estimated an increase in mortality from 11.0% to 14.7% (relative increase of 34%) with a 10 week delay in ART for patients entering care with our pre-ART cohort CD4 distribution. When we examined low CD4 ranges, the relative increase in mortality delays remained similar; however, the absolute increase in mortality rose. For example, among patients entering with CD4 count 50–99 cells/mm3, 12 month mortality increased from 13.3% with no delay compared to 17.0% with a 10 week delay and 22.9% with a 6 month delay. Conclusions Delays in ART initiation, common in routine HIV programs, can lead to important increases in mortality. Prompt ART initiation for patients entering clinical care and eligible for ART, especially those with lower CD4 counts, could be a relatively low cost approach with a potential marked impact on mortality. PMID:23392457

  14. Mortality associated with delays between clinic entry and ART initiation in resource-limited settings: results of a transition-state model.

    Science.gov (United States)

    Hoffmann, Christopher J; Lewis, James J; Dowdy, David W; Fielding, Katherine L; Grant, Alison D; Martinson, Neil A; Churchyard, Gavin J; Chaisson, Richard E

    2013-05-01

    To estimate the mortality impact of delay in antiretroviral therapy (ART) initiation from the time of entry into care. A state-transition Markov process model. This technique allows for assessing mortality before and after ART initiation associated with delays in ART initiation among a general population of ART-eligible patients without conducting a randomized trial. We used patient-level data from 3 South African cohorts to determine transition probabilities for pre-ART CD4 count changes and pre-ART and on-ART mortality. For each parameter, we generated probabilities and distributions for Monte Carlo simulations with 1-week cycles to estimate mortality 52 weeks from clinic entry. We estimated an increase in mortality from 11.0% to 14.7% (relative increase of 34%) with a 10-week delay in ART for patients entering care with our pre-ART cohort CD4 distribution. When we examined low CD4 ranges, the relative increase in mortality delays remained similar; however, the absolute increase in mortality rose. For example, among patients entering with CD4 count 50-99 cells per cubic millimeter, 12-month mortality increased from 13.3% with no delay compared with 17.0% with a 10-week delay and 22.9% with a 6-month delay. Delays in ART initiation, common in routine HIV programs, can lead to important increases in mortality. Prompt ART initiation for patients entering clinical care and eligible for ART, especially those with lower CD4 counts, could be a relatively low-cost approach with a potential marked impact on mortality.

  15. Is the evolution of clutch size limited by incubation ability in shorebirds?

    OpenAIRE

    Beatty, Jessica Lynne

    2015-01-01

    Incubation is a crucial aspect of avian life history where differences in incubation techniques and investments can have long lasting effects on offspring and parental well- being and reproductive success. The factors limiting why some birds, such as shorebirds, have fixed clutch sizes has intrigued life history theorist to propose different hypotheses about the evolution of clutch size. Lack's "incubation limitation hypothesis," suggesting that clutch size is limited by the amount of eggs a ...

  16. Evolution of parental incubation behaviour in dinosaurs cannot be inferred from clutch mass in birds

    OpenAIRE

    Birchard, Geoffrey F.; Ruta, Marcello; Deeming, D. Charles

    2013-01-01

    A recent study proposed that incubation behaviour (i.e. type of parental care) in theropod dinosaurs can be inferred from an allometric analysis of clutch volume in extant birds. However, the study in question failed to account for factors known to affect egg and clutch size in living bird species. A new scaling analysis of avian clutch mass demonstrates that type of parental care cannot be distinguished by conventional allometry because of the confounding effects of phylogeny and hatchling m...

  17. Nest predation, clutch size, and physiological costs of egg production in the song sparrow (Melospiza melodia)

    OpenAIRE

    Travers, Marc Simon

    2009-01-01

    We examined the effects of nest predation on both clutch size and the physiological cost of egg production using a clutch removal experiment in free-living song sparrows (Melospiza melodia), inducing “high nest predation” (HNP) females to produce many replacement clutches compared to “low nest predation” (LNP) females. In a preliminary analysis we investigated the utility of multiple measures to assess “physiological condition”, including inter-correlations between physiological traits, sex d...

  18. Temperature control of an automotive engine cooling system utilizing a magneto-rheological fan clutch

    International Nuclear Information System (INIS)

    Kim, Eun-Seok; Choi, Seung-Bok; Park, Young-Gee; Lee, Soojin

    2010-01-01

    In this note, the temperature control of an automotive engine cooling system is undertaken using a magneto-rheological (MR) fluid-based fan clutch (MR fan clutch in short). In order to achieve this goal, an appropriate size of controllable fan clutch using an MR fluid is firstly devised by considering the design parameters of a conventional fan clutch to reflect the practical application. Then, the principal design parameters of the MR fan clutch such as the length of the disc are optimally determined through finite element analysis. The drum-type MR fan clutch is manufactured and its time response to input current is experimentally evaluated. A robust sliding mode controller is then formulated by treating the time constant of the fan clutch system as an uncertain parameter. After identifying the relationship between angular velocity of the MR fan clutch and the temperature of the cooling system, the sliding mode controller is experimentally realized for the cooling system. It has been clearly demonstrated that the proposed sliding mode controller follows well the desired temperature with a small regulating error. It is expected from this feasibility work that the proposed control system associated with an MR fan clutch can be effectively utilized for the automotive cooling system to improve the fuel efficiency. (technical note)

  19. Delayed initiation but not gradual advancement of enteral formula feeding reduces the incidence of necrotizing enterocolitis (NEC in preterm pigs.

    Directory of Open Access Journals (Sweden)

    Nada Ghoneim

    Full Text Available Enteral formula feeding is a risk factor for necrotizing enterocolitis (NEC in premature infants, yet studies are conflicting regarding the safest timing for introduction and advancement of feeds. Our aim was to test the effects of early vs. late initiation and abrupt vs. gradual advancement of enteral feeding of an intact vs. hydrolyzed protein formula on NEC incidence and severity in preterm pigs. In Experiment 1, preterm pigs received total parenteral nutrition (TPN at birth with abrupt initiation of enteral formula feeds (50% full intake on d of life (DOL 2 (EA or 5 (LA while PN continued. Pigs were also fed formula containing either intact or hydrolyzed protein. In Experiment 2, preterm pigs received TPN at birth with enteral, hydrolyzed-protein formula feeds introduced on DOL 2 either abruptly (EA; 50% full feeds or gradually (EG; 10-50% full feeds over 5 d while PN continued. NEC incidence and severity were assessed based on macroscopic and histological scoring. In Experiment 1, NEC incidence (41% vs. 70%, P<0.05 and severity were reduced in LA vs. EA groups and LA was associated with a higher survival rate, daily weight gain and jejunum villus height. Piglets fed hydrolyzed vs. intact protein formula had lower stomach content weights and similar NEC incidence. In Experiment 2, NEC incidence and severity were not different between pigs the EG vs. EA group. Proinflammatory gene expression (IL-1β, IL-6 and S100A9 in the ileum was lower in both LA and EG vs. EA groups. In conclusion, delayed initiation but not gradual advancement of enteral feeding is protective against NEC in preterm pigs. Feeding hydrolyzed vs. intact protein formula improved gastric transit without affecting the NEC incidence.

  20. Adaptive Tracking Control of an Electro-Pneumatic Clutch Actuator

    Directory of Open Access Journals (Sweden)

    Glenn-Ole Kaasa

    2003-10-01

    Full Text Available This paper deals with the application of a simple adaptive algorithm for robust tracking control of an electro-pneumatic clutch actuator with output feedback. We present a mathematical model of the strongly nonlinear system, and implement an adaptive algorithm, based on a parallel feedforward compensator (PFC to remove the relative-degree-1 restriction. We propose a practical method of constructing the PFC, and introduce a simple modification that removes an inherent restriction on bandwidth of the nonlinear system. We show that the adaptive algorithm deals well with nonlinearities, and we achieve tracking corresponding to a settling-time of 150 ms.

  1. Systemic delays in the initiation of antiretroviral therapy during pregnancy do not improve outcomes of HIV-positive mothers: a cohort study

    Directory of Open Access Journals (Sweden)

    Myer Landon

    2012-09-01

    Full Text Available Abstract Background Antiretroviral therapy (ART initiation in eligible HIV-infected pregnant women is an important intervention to promote maternal and child health. Increasing the duration of ART received before delivery plays a major role in preventing vertical HIV transmission, but pregnant women across Africa experience significant delays in starting ART, partly due the perceived need to deliver ART counseling and patient education before ART initiation. We examined whether delaying ART to provide pre-ART counseling was associated with improved outcomes among HIV-infected women in Cape Town, South Africa. Methods We undertook a retrospective cohort study of 490 HIV-infected pregnant women referred to initiate treatment at an urban ART clinic. At this clinic all patients including pregnant women are screened by a clinician and then undergo three sessions of counseling and patient education prior to starting treatment, commonly introducing delays of 2–4 weeks before ART initiation. Data on viral suppression and retention in care after ART initiation were taken from routine clinic records. Results A total of 382 women initiated ART before delivery (78%; ART initiation before delivery was associated with earlier gestational age at presentation to the ART service (p  Conclusions A substantial proportion of eligible pregnant women referred for ART do not begin treatment before delivery in this setting. Among women who do initiate ART, delaying initiation for patient preparation is not associated with improved maternal outcomes. Given the need to maximize the duration of ART before delivery for prevention of mother-to-child HIV transmission, there is an urgent need for new strategies to help expedite ART initiation in eligible pregnant women.

  2. The geometric clutch at 20: stripping gears or gaining traction?

    Science.gov (United States)

    Lindemann, Charles B; Lesich, Kathleen A

    2015-08-01

    It has been 20 years since the geometric clutch (GC) hypothesis was first proposed. The core principle of the GC mechanism is fairly simple. When the axoneme of a eukaryotic flagellum is bent, mechanical stress generates forces transverse to the outer doublets (t-forces). These t-forces can push doublets closer together or pry them apart. The GC hypothesis asserts that changes in the inter-doublet spacing caused by t-forces are responsible for the activation and deactivation of the dynein motors, that creates the beat cycle. A series of computer models utilizing the clutch mechanism has shown that it can simulate ciliary and flagellar beating. The objective of the present review is to assess where things stand with the GC hypothesis in the clarifying light of new information. There is considerable new evidence to support the hypothesis. However, it is also clear that it is necessary to modify some of the original conceptions of the hypothesis so that it can be consistent with the results of recent experimental and ultrastructural studies. In particular, dynein deactivation by t-forces must be able to occur with dyneins that remain attached to the B-subtubule of the adjacent doublet. © 2015 Society for Reproduction and Fertility.

  3. Fitness cost of incubation in great tits (Parus major) is related to clutch size

    NARCIS (Netherlands)

    de Heij, Maaike E.; van den Hout, Piet J.; Tinbergen, Joost M.

    2006-01-01

    Life-history theory predicts that parents produce the number of offspring that maximizes their fitness. In birds, natural selection on parental decisions regarding clutch size may act during egg laying, incubation or nestling phase. To study the fitness consequences of clutch size during the

  4. Females paired with new and heavy mates reduce intra-clutch differences in resource allocation.

    Directory of Open Access Journals (Sweden)

    Maud Poisbleau

    Full Text Available Reproductive investment affects both offspring and parental fitness and influences the evolution of life histories. Females may vary their overall primary reproductive effort in relation to the phenotypic characteristics of their mate. However, the effects of male quality on differential resource allocation within clutches have been largely neglected despite the potential implications for mate choice and population dynamics, especially in species exhibiting biparental care and brood reduction. Female southern rockhopper penguins Eudyptes chrysocome paired with heavy mates reduced intra-clutch variation in egg and albumen masses. Females paired with new mates also reduced intra-clutch variation in yolk androgen levels. Since both an increased mass and increased androgen concentrations positively influence chick survival under sibling competition, the chances of fledging the whole clutch are likely to be higher for newly formed pairs with heavy males than for previously formed pairs with light males. Interestingly, total clutch provisioning did not vary with male quality. We show for the first time that females vary intra-clutch variation in resource allocation according to male quality. In species with brood reduction, it may be more adaptive for females to modulate the distribution of resources within the clutch according to breeding conditions, than to change their total clutch provisioning.

  5. Development of magneto-rheologial fluid (MRF) based clutch for output torque control of AC motors

    Science.gov (United States)

    Nguyen, Q. Hung; Do, H. M. Hieu; Nguyen, V. Quoc; Nguyen, N. Diep; Le, D. Thang

    2018-03-01

    In industry, the AC motor is widely used because of low price, power availability, low cost maintenance. The main disadvantages of AC motors compared to DC motors are difficulty in speed and torque control, requiring expensive controllers with complex control algorithms. This is the basic limitations in the widespread adoption of AC motor systems for industrial automation. One feasible solution for AC motor control is using MRF (magneto-rheological fluid) based clutches (shortly called MR clutches) Although there have been many studies on MR clutches, most of these clutches used traditional configuration with coils wound on the middle cylindrical part and a compotator is used to supply power to the coils. Therefore, this type of MR clutches possesses many disadvantages such as high friction and unstable applied current due to commutator, complex structure which causes difficulty in manufacture, assembly, and maintenance. In addition, the bottleneck problem of magnetic field is also a challenging issue. In this research, we will develop a new type of MR clutches that overcomes the abovementioned disadvantages of traditional MR clutches and more suitable for application in controlling of AC motor. Besides, in this study, speed and torque control system for AC motors using developed MR clutches is designed and experimental validated.

  6. Organochlorine contaminants in complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs from Belize

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ted H. [Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775-6160 (United States); Canas, Jaclyn E. [Institute of Environmental and Human Health, Texas Tech University, Box 41163, Lubbock, TX 79409 (United States); Rainwater, Thomas R. [Institute of Environmental and Human Health, PO Box 764, Jefferson, TX 75657 (United States); Platt, Steven G. [Department of Math and Science, Oglala Lakota College, 490 Piya Wiconi Road, Kyle, SD, 57752 (United States); McMurry, Scott T. [Institute of Environmental and Human Health, Texas Tech University, Box 41163, Lubbock, TX 79409 (United States); Anderson, Todd A. [Institute of Environmental and Human Health, Texas Tech University, Box 41163, Lubbock, TX 79409 (United States)]. E-mail: todd.anderson@ttu.edu

    2006-11-15

    Seven complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs were collected in northern Belize and examined for organochlorine (OC) pesticide residues. The primary OC detected, p,p-DDE, was found in every egg analyzed (n = 175). Other OCs detected included p,p-DDT, p,p-DDD, methoxychlor, aldrin, and endosulfan I. Concentrations of individual OCs ranged from 4 ppb (ng chemical/g egg wet weight) to greater than 500 ppb. A statistical evaluation of p,p-DDE levels in three complete clutches was used to derive the minimum number of eggs needed from a clutch to precisely determine the mean p,p-DDE concentration representative of that clutch. Sample sizes of 8 (80% confidence level) and 11 (90% confidence level) were determined to yield an accurate estimate of contaminant levels in a full clutch of eggs. The statistically recommended sample size of 11 eggs (at 90% confidence level) was successfully tested on the four additional clutches. -- Sampling the non-viable eggs of a clutch can provide a statistically reasonable estimation of both the organochlorine contaminant distribution and concentrations in that clutch.

  7. Effects of early versus delayed initiation of antiretroviral treatment on clinical outcomes of HIV-1 infection: results from the phase 3 HPTN 052 randomised controlled trial

    Science.gov (United States)

    Grinsztejn, Beatriz; Hosseinipour, Mina C; Ribaudo, Heather J; Swindells, Susan; Eron, Joseph; Chen, Ying Q; Wang, Lei; Ou, San-San; Anderson, Maija; McCauley, Marybeth; Gamble, Theresa; Kumarasamy, Nagalingeshwaran; Hakim, James G; Kumwenda, Johnstone; Pilotto, Jose H S; Godbole, Sheela V; Chariyalertsak, Suwat; de Melo, Marineide Gonçalves; Mayer, Kenneth H; Eshleman, Susan H; Piwowar-Manning, Estelle; Makhema, Joseph; Mills, Lisa A; Panchia, Ravindre; Sanne, Ian; Gallant, Joel; Hoffman, Irving; Taha, Taha E; Nielsen-Saines, Karin; Celentano, David; Essex, Max; Havlir, Diane; Cohen, Myron S

    2014-01-01

    Summary Background Use of antiretroviral treatment for HIV-1 infection has decreased AIDS-related morbidity and mortality and prevents sexual transmission of HIV-1. However, the best time to initiate antiretroviral treatment to reduce progression of HIV-1 infection or non-AIDS clinical events is unknown. We reported previously that early antiretroviral treatment reduced HIV-1 transmission by 96%. We aimed to compare the effects of early and delayed initiation of antiretroviral treatment on clinical outcomes. Methods The HPTN 052 trial is a randomised controlled trial done at 13 sites in nine countries. We enrolled HIV-1-serodiscordant couples to the study and randomly allocated them to either early or delayed antiretroviral treatment by use of permuted block randomisation, stratified by site. Random assignment was unblinded. The HIV-1-infected member of every couple initiated antiretroviral treatment either on entry into the study (early treatment group) or after a decline in CD4 count or with onset of an AIDS-related illness (delayed treatment group). Primary events were AIDS clinical events (WHO stage 4 HIV-1 disease, tuberculosis, and severe bacterial infections) and the following serious medical conditions unrelated to AIDS: serious cardiovascular or vascular disease, serious liver disease, end-stage renal disease, new-onset diabetes mellitus, and non-AIDS malignant disease. Analysis was by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT00074581. Findings 1763 people with HIV-1 infection and a serodiscordant partner were enrolled in the study; 886 were assigned early antiretroviral treatment and 877 to the delayed treatment group (two individuals were excluded from this group after randomisation). Median CD4 counts at randomisation were 442 (IQR 373–522) cells per μL in patients assigned to the early treatment group and 428 (357–522) cells per μL in those allocated delayed antiretroviral treatment. In the delayed group

  8. Modeling and analysis of friction clutch at a driveline for suppressing car starting judder

    Science.gov (United States)

    Li, Liping; Lu, Zhaijun; Liu, Xue-Lai; Sun, Tao; Jing, Xingjian; Shangguan, Wen-Bin

    2018-06-01

    Car judder is a kind of back-forth vibration during vehicle starting which caused by the torsional oscillation of the driveline. This paper presents a systematic study on the dynamic response characteristics of the clutch driven disc for suppression of the judder during vehicle starting. Self-excited vibration behavior of the clutch driven disc is analyzed based on the developed 4DOF non-linear multi-body dynamic model of the clutch driving process considering stick-slip characteristics and using Karnopp friction models. Physical parameters of a clutch determining the generations of the judder behaviors are discussed and the revised designs of the driven disc of a clutch for suppression of the judder are consequently investigated and validated with experiments for two real cars.

  9. Finite element fatigue analysis of rectangular clutch spring of automatic slack adjuster

    Science.gov (United States)

    Xu, Chen-jie; Luo, Zai; Hu, Xiao-feng; Jiang, Wen-song

    2015-02-01

    The failure of rectangular clutch spring of automatic slack adjuster directly affects the work of automatic slack adjuster. We establish the structural mechanics model of automatic slack adjuster rectangular clutch spring based on its working principle and mechanical structure. In addition, we upload such structural mechanics model to ANSYS Workbench FEA system to predict the fatigue life of rectangular clutch spring. FEA results show that the fatigue life of rectangular clutch spring is 2.0403×105 cycle under the effect of braking loads. In the meantime, fatigue tests of 20 automatic slack adjusters are carried out on the fatigue test bench to verify the conclusion of the structural mechanics model. The experimental results show that the mean fatigue life of rectangular clutch spring is 1.9101×105, which meets the results based on the finite element analysis using ANSYS Workbench FEA system.

  10. Study on the Control Strategy of Shifting Time Involving Multigroup Clutches

    Directory of Open Access Journals (Sweden)

    Zhen Zhu

    2016-01-01

    Full Text Available This paper focuses on the control strategy of shifting time involving multigroup clutches for a hydromechanical continuously variable transmission (HMCVT. The dynamic analyses of mathematical models are presented in this paper, and the simulation models are used to study the control strategy of HMCVT. Simulations are performed in Simulation X platform to investigate the shifting time of clutches under different operating conditions. On this basis, simulation analysis and test verification of two typical conditions, which play the decisive roles for the shifting quality, are carried out. The results show that there are differences in the shifting time of the two typical conditions. In the shifting process from the negative transmission of hydromechanical ranges to the positive transmission of hydromechanical ranges, the control strategy based on the shifting time is switching the clutches of shifting mechanism firstly and then disengaging a group of clutches of planetary gear mechanism and engaging another group of the clutches of planetary gear mechanism lastly. In the shifting process from the hydraulic range to the hydromechanical range, the control strategy based on the shifting time is switching the clutches of hydraulic shifting mechanism and planetary gear mechanism at first and then engaging the clutch of shifting mechanism.

  11. Clutch size in populations and species of cnemidophorines (Squamata: Teiidae on the eastern coast of Brazil

    Directory of Open Access Journals (Sweden)

    VANDERLAINE A. MENEZES

    2014-06-01

    Full Text Available We analyzed some reproductive aspects of 16 coastal populations, belonging to five lizard species (A. ocellifera, A. abaetensis, A. nativo, A. littoralis and C. lacertoides from different restinga habitats along the eastern coast of Brazil. This study aimed to evaluate to what extent the reproductive aspects vary geographically and among species. For each female, we recorded the number of vitellogenic follicles, size and color of the largest follicle, presence and size of corpora lutea, and number and size of oviductal eggs. Clutch size of almost all coastal populations/species of Ameivula had little variation and most clutches were composed of two eggs. There was a significant relationship between female size and the mean clutch size when females from different species were pooled. Mean egg volume, among species, varied from 420 to 655 mm3. Relative clutch mass varied from 0.129 to 0.159 and did not differ significantly among species. We concluded that the five coastal species studied (four bisexuals and one parthenogenetic had similar reproductive characteristics. Most of them presented multiple clutches, low clutch size and low relative clutch mass, similar to other species in the genus and to unisexual and bisexual species of the Teiidae family.

  12. On the Energy Efficiency of Dual Clutch Transmissions and Automated Manual Transmissions

    Directory of Open Access Journals (Sweden)

    Fabio Vacca

    2017-10-01

    Full Text Available The main benefits of dual clutch transmissions (DCTs are: (i a higher energy efficiency than automatic transmission systems with torque converters; and (ii the capability to fill the torque gap during gear shifts to allow seamless longitudinal acceleration profiles. Therefore, DCTs are viable alternatives to automated manual transmissions (AMTs. For vehicles equipped with engines that can generate considerable torque, large clutch-slip energy losses occur during power-on gear shifts and, as a result, DCTs need wet clutches for effective heat dissipation. This requirement substantially reduces DCT efficiency because of the churning and ancillary power dissipations associated with the wet clutch pack. To the knowledge of the authors, this study is the first to analyse the detailed power loss contributions of a DCT with wet clutches, and their relative significance along a set of driving cycles. Based on these results, a novel hybridised AMT (HAMT with a single dry clutch and an electric motor is proposed for the same vehicle. The HAMT architecture combines the high mechanical efficiency typical of AMTs with a single dry clutch, with the torque-fill capability and operational flexibility allowed by the electric motor. The measured efficiency maps of a case study DCT and HAMT are compared. This is then complemented by the analysis of the respective fuel consumption along the driving cycles, which is simulated with an experimentally validated vehicle model. In its internal combustion engine mode, the HAMT reduces fuel consumption by >9% with respect to the DCT.

  13. Egg clutch dehydration induces early hatching in red-eyed treefrogs, Agalychnis callidryas

    Directory of Open Access Journals (Sweden)

    María José Salica

    2017-07-01

    Full Text Available Terrestrial eggs have evolved repeatedly in tropical anurans exposing embryos to the new threat of dehydration. Red-eyed treefrogs, Agalychnis callidryas, lay eggs on plants over water. Maternally provided water allows shaded eggs in humid sites to develop to hatching without rainfall, but unshaded eggs and those in less humid sites can die from dehydration. Hatching responses of amphibian eggs to dry conditions are known from two lineages with independent origins of terrestrial eggs. Here, we experimentally tested for dehydration-induced early hatching in another lineage (Agalychnis callidryas, Phyllomedusidae, representing a third independent origin of terrestrial eggs. We also investigated how dehydration affected egg and clutch structure, and egg mortality. We collected clutches from a pond in Gamboa, Panama, and randomly allocated them to wet or dry treatments at age 1 day. Embryos hatched earlier from dry clutches than from wet clutches, accelerating hatching by ∼11%. Clutch thickness and egg diameter were affected by dehydration, diverging between treatments over time. Meanwhile, mortality in dry clutches was six-fold higher than in control clutches. With this study, early hatching responses to escape mortality from egg dehydration are now known from three anuran lineages with independent origins of terrestrial eggs, suggesting they may be widespread. Further studies are needed to understand how terrestrial amphibian eggs can respond to, or will be affected by, rapid changes in climate over the next decades.

  14. Computing eigenvalue sensitivity coefficients to nuclear data based on the CLUTCH method with RMC code

    International Nuclear Information System (INIS)

    Qiu, Yishu; She, Ding; Tang, Xiao; Wang, Kan; Liang, Jingang

    2016-01-01

    Highlights: • A new algorithm is proposed to reduce memory consumption for sensitivity analysis. • The fission matrix method is used to generate adjoint fission source distributions. • Sensitivity analysis is performed on a detailed 3D full-core benchmark with RMC. - Abstract: Recently, there is a need to develop advanced methods of computing eigenvalue sensitivity coefficients to nuclear data in the continuous-energy Monte Carlo codes. One of these methods is the iterated fission probability (IFP) method, which is adopted by most of Monte Carlo codes of having the capabilities of computing sensitivity coefficients, including the Reactor Monte Carlo code RMC. Though it is accurate theoretically, the IFP method faces the challenge of huge memory consumption. Therefore, it may sometimes produce poor sensitivity coefficients since the number of particles in each active cycle is not sufficient enough due to the limitation of computer memory capacity. In this work, two algorithms of the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via Tracklength importance CHaracterization (CLUTCH) method, namely, the collision-event-based algorithm (C-CLUTCH) which is also implemented in SCALE and the fission-event-based algorithm (F-CLUTCH) which is put forward in this work, are investigated and implemented in RMC to reduce memory requirements for computing eigenvalue sensitivity coefficients. While the C-CLUTCH algorithm requires to store concerning reaction rates of every collision, the F-CLUTCH algorithm only stores concerning reaction rates of every fission point. In addition, the fission matrix method is put forward to generate the adjoint fission source distribution for the CLUTCH method to compute sensitivity coefficients. These newly proposed approaches implemented in RMC code are verified by a SF96 lattice model and the MIT BEAVRS benchmark problem. The numerical results indicate the accuracy of the F-CLUTCH algorithm is the same as the C-CLUTCH

  15. Evolution of parental incubation behaviour in dinosaurs cannot be inferred from clutch mass in birds.

    Science.gov (United States)

    Birchard, Geoffrey F; Ruta, Marcello; Deeming, D Charles

    2013-08-23

    A recent study proposed that incubation behaviour (i.e. type of parental care) in theropod dinosaurs can be inferred from an allometric analysis of clutch volume in extant birds. However, the study in question failed to account for factors known to affect egg and clutch size in living bird species. A new scaling analysis of avian clutch mass demonstrates that type of parental care cannot be distinguished by conventional allometry because of the confounding effects of phylogeny and hatchling maturity. Precociality of young but not paternal care in the theropod ancestors of birds is consistent with the available data.

  16. Adding Recognition Discriminability Index to the Delayed Recall Is Useful to Predict Conversion from Mild Cognitive Impairment to Alzheimer's Disease in the Alzheimer's Disease Neuroimaging Initiative.

    Science.gov (United States)

    Russo, María J; Campos, Jorge; Vázquez, Silvia; Sevlever, Gustavo; Allegri, Ricardo F

    2017-01-01

    Background: Ongoing research is focusing on the identification of those individuals with mild cognitive impairment (MCI) who are most likely to convert to Alzheimer's disease (AD). We investigated whether recognition memory tasks in combination with delayed recall measure of episodic memory and CSF biomarkers can predict MCI to AD conversion at 24-month follow-up. Methods: A total of 397 amnestic-MCI subjects from Alzheimer's disease Neuroimaging Initiative were included. Logistic regression modeling was done to assess the predictive value of all RAVLT measures, risk factors such as age, sex, education, APOE genotype, and CSF biomarkers for progression to AD. Estimating adjusted odds ratios was used to determine which variables would produce an optimal predictive model, and whether adding tests of interaction between the RAVLT Delayed Recall and recognition measures (traditional score and d-prime) would improve prediction of the conversion from a-MCI to AD. Results: 112 (28.2%) subjects developed dementia and 285 (71.8%) subjects did not. Of the all included variables, CSF Aβ1-42 levels, RAVLT Delayed Recall, and the combination of RAVLT Delayed Recall and d-prime were predictive of progression to AD (χ 2 = 38.23, df = 14, p < 0.001). Conclusions: The combination of RAVLT Delayed Recall and d-prime measures may be predictor of conversion from MCI to AD in the ADNI cohort, especially in combination with amyloid biomarkers. A predictive model to help identify individuals at-risk for dementia should include not only traditional episodic memory measures (delayed recall or recognition), but also additional variables (d-prime) that allow the homogenization of the assessment procedures in the diagnosis of MCI.

  17. Current Best Practices for Preventing Asbestos Exposure Among Brake and Clutch Repair Workers

    Science.gov (United States)

    Covers concerns about asbestos exposure for mechanics, how to tell if asbestos brake or clutch components contain asbestos, work practices to follow, protecting yourself for home mechanics, disposal of waste that contains asbestos.

  18. Detection technology research on the one-way clutch of automatic brake adjuster

    Science.gov (United States)

    Jiang, Wensong; Luo, Zai; Lu, Yi

    2013-10-01

    In this article, we provide a new testing method to evaluate the acceptable quality of the one-way clutch of automatic brake adjuster. To analysis the suitable adjusting brake moment which keeps the automatic brake adjuster out of failure, we build a mechanical model of one-way clutch according to the structure and the working principle of one-way clutch. The ranges of adjusting brake moment both clockwise and anti-clockwise can be calculated through the mechanical model of one-way clutch. Its critical moment, as well, are picked up as the ideal values of adjusting brake moment to evaluate the acceptable quality of one-way clutch of automatic brake adjuster. we calculate the ideal values of critical moment depending on the different structure of one-way clutch based on its mechanical model before the adjusting brake moment test begin. In addition, an experimental apparatus, which the uncertainty of measurement is ±0.1Nm, is specially designed to test the adjusting brake moment both clockwise and anti-clockwise. Than we can judge the acceptable quality of one-way clutch of automatic brake adjuster by comparing the test results and the ideal values instead of the EXP. In fact, the evaluation standard of adjusting brake moment applied on the project are still using the EXP provided by manufacturer currently in China, but it would be unavailable when the material of one-way clutch changed. Five kinds of automatic brake adjusters are used in the verification experiment to verify the accuracy of the test method. The experimental results show that the experimental values of adjusting brake moment both clockwise and anti-clockwise are within the ranges of theoretical results. The testing method provided by this article vividly meet the requirements of manufacturer's standard.

  19. Ergonomic assessment of drivers in MF285 and MF399 tractors during clutching using algometer

    OpenAIRE

    Hossein Fallahi; Mohammad Hossein Abbaspour-Fard; Amin Azhari; Mehdi Khojastehpour; Amin Nikkhah

    2016-01-01

    Tractor as one of the most widely used agricultural machinery should be considered from different aspects. The frequent application of clutch and brake pedals and also the steering wheel within farms, along with the unfavorable working conditions, cause negative effects on the occupational health of the tractor drivers. Thus, in this research, the imposed forces on three engaged muscles including: Gastrocnemius, Trapezius and Quadrate’s lumborum of the tractor drivers during clutching have be...

  20. Peculiarities of Clutch Forming Rails and Wheel Block Construction

    Science.gov (United States)

    Shiler, V. V.; Galiev, I. I.; Shiler, A. V.

    2018-03-01

    The clutch of the wheel and rail is significantly influenced by the design features of the standard wheel pair, which are manifested in the presence of "parasitic" slipping of the wheels along the rails during its movement. The purpose of the presented work is to evaluate new design solutions for wheel sets. The research was carried out using methods of comparative simulation modelling and physical prototyping. A new design of the wheel pair (block wheel pair) is proposed, which features an independent rotation of all surfaces of the wheels in contact with the rails. The block construction of the wheel pair forms open mechanical contours with the track gauge, which completely eliminates the "parasitic" slippage. As a result, in the process of implementing traction or braking forces, the coupling coefficient of the block construction of the wheel pair is significantly higher than that of existing structures. In addition, in the run-out mode, the resistance to movement of the block wheel pair is half as much. All this will allow one to significantly reduce the energy consumption for traction of trains, wear of track elements and crew, and to increase the speed and safety of train traffic.

  1. Development of a novel two-layer multiplate magnetorheological clutch for high-power applications

    International Nuclear Information System (INIS)

    Wang, Daoming; Tian, Zuzhi; Meng, Qingrui; Hou, Youfu

    2013-01-01

    A novel magnetorheological (MR) clutch for high-power applications is designed, simulated and tested. The clutch is implemented in a two-layer multiplate transmission form and adopts a two-way liquid cooling method to improve the heat dissipation capability. In this paper, a brief introduction to the transmission form of the proposed MR clutch is given first. Then, theoretical analyses of the output torque, magnetic circuit and temperature characteristic are conducted and further design details are presented and discussed, followed by a magnetostatic simulation of the designed circuit. A prototype of the clutch was fabricated and several tests were carried out to evaluate the torque transmission, time response and steady slip power of the prototype. The results show that the proposed MR clutch can produce a maximum output torque of 1545 N m and possesses a high steady slip power of up to 35 kW. Therefore, the developed two-layer multiplate MR clutch is promising for applications in many high-power situations. (paper)

  2. Environmental influences on egg and clutch sizes in lentic- and lotic-breeding salamanders

    Directory of Open Access Journals (Sweden)

    Jon M. Davenport

    2010-12-01

    Full Text Available Recent research indicates that social and environmental factors influence egg and clutch sizes in amphibians. However, most of this work is based on the reproductively diverse order Anura (frogs and toads, whereas less research has been conducted on Caudata (salamanders and Gymnophiona (caecilians. Researchers have suggested that a relationship exists between social and environmental factors and egg and clutch sizes in salamanders, but studies controlling for phylogenetic context are lacking. We could not identify a sufficient number of comparisons for social influences on egg and clutch sizes; therefore, we focused on environmental influences for this study. Data on egg size, clutch size, environmental factors, and phylogenies for salamanders were assembled from the scientific literature. We used independent, pair-wise comparisons to investigate the association of larval salamander habitat and egg size and the association of larval salamander habitat with clutch sizes within a phylogenetic framework. There is a significant association between larval habitat and egg size; specifically, stream-breeding species produce larger eggs. There is no significant association between larval habitat and clutchsize. Our study confirms earlier reports that salamander egg size is associated with larval environments, but is the first to use phylogenetically independent contrasts to account for the lack of phylogenetic independence of the traits measured (egg size and clutch size associated with many of the diverse lineages. Our study shows that environmental selection pressure can be quite strong on one aspect of salamander reproduction—egg size.

  3. Performing under pressure: Exploring the psychological state underlying clutch performance in sport.

    Science.gov (United States)

    Swann, Christian; Crust, Lee; Jackman, Patricia; Vella, Stewart A; Allen, Mark S; Keegan, Richard

    2017-12-01

    Clutch performance is improved performance under pressure. However, little research has examined the psychological state experienced by athletes in these situations. Therefore, this study qualitatively examined the subjective experience underlying clutch performance across a range of sports (e.g., team, individual) and standards (Olympic to recreational athletes). Sixteen athletes (M age  = 27.08 years; SD = 6.48) took part in in-depth, semi-structured interviews primarily after an exceptional performance (M = 4.38 days later; SD = 3.14). Data were analysed inductively and thematically. Clutch states involved 12 characteristics, including heightened and deliberate concentration, intense effort, and heightened awareness, which distinguished the experience of clutch from other optimal psychological states such as flow. Other characteristics, such as perceptions of control, were also reported and supported previous experimental research on clutch. These findings present in-depth qualitative insights into the psychological state underlying clutch performance, and are discussed in relation to the existing literature on optimal psychological states in sport.

  4. Predictive Reliability Assessment of the Automatic Clutch on a Primary Sodium Pump Drive

    International Nuclear Information System (INIS)

    Westwell, P.

    1975-01-01

    This paper examines the reliability of a group of three clutch couplings each mounted between a pony motor and the main drive for the primary sodium pumps. The sodium pumps specification requires that continuously running AC pony motors be fitted to give a guaranteed 10% drive to the pumps in the event of a main supply failure. The drive to the main shaft is via 3 : 1 reduction gearing such that a six pole pony motor running at 300 rpm would drive the main shaft at 100 rpm i.e., 10% of its rated speed. In order that the pony motor drive could be permanently energised during normal operation a free wheeling clutch is fitted between the motor and the reduction gearing. The type of clutch chosen is. the Synchro-Self Shifting (SSS) clutch, shown in Figure 1. This type of clutch has proved itself under fairly onerous operating conditions, but is normally mounted on a horizontal driving shaft whereas in this case because of space limitations, it is necessary to mount it vertically. The reliability target set is that the chance of losing all three independent back-up pony motor drives on loss of main supplies should fall within the 10 -5 - 10 -6 band. Since the electrical supplies and other parts of the pony motor drives have been assessed within this target and some doubts expressed about the clutch it was now necessary to look at this in some detail

  5. Comparison of initial and delayed myocardial imaging with beta-methyl-p-[123I]-iodophenylpentadecanoic acid in acute myocardial infarction

    International Nuclear Information System (INIS)

    Naruse, Hitoshi; Yoshimura, Noriko; Yamamoto, Juro; Morita, Masato; Fukutake, Naoshige; Ohyanagi, Mitsumasa; Iwasaki, Tadaaki; Fukuchi, Minoru

    1994-01-01

    Myocardial imaging using β-methyl-p-[ 123 I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess 'fill-in' and 'washout' defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed 'fill-in' defects, and 24/180 segments (13%) showed 'washout' defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with 'fill-in' defects was 9.0±16.6%, and that of 'washout' defects was 24.9±18.1% which was significantly higher than in controls (8.7±15.4%, p<0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion. (author)

  6. Comparison of initial and delayed myocardial imaging with beta-methyl-p-[[sup 123]I]-iodophenylpentadecanoic acid in acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, Hitoshi; Yoshimura, Noriko; Yamamoto, Juro; Morita, Masato; Fukutake, Naoshige; Ohyanagi, Mitsumasa; Iwasaki, Tadaaki; Fukuchi, Minoru (Hyogo Coll. of Medicine, Nishinomiya (Japan))

    Myocardial imaging using [beta]-methyl-p-[[sup 123]I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess 'fill-in' and 'washout' defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed 'fill-in' defects, and 24/180 segments (13%) showed 'washout' defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with 'fill-in' defects was 9.0[+-]16.6%, and that of 'washout' defects was 24.9[+-]18.1% which was significantly higher than in controls (8.7[+-]15.4%, p<0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion. (author).

  7. [Comparison of initial and delayed myocardial imaging with beta-methyl-p-[123I]-iodophenylpentadecanoic acid in acute myocardial infarction].

    Science.gov (United States)

    Naruse, H; Yoshimura, N; Yamamoto, J; Morita, M; Fukutake, N; Ohyanagi, M; Iwasaki, T; Fukuchi, M

    1994-01-01

    Myocardial imaging using beta-methyl-p-[123I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess "fill-in" and "washout" defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed "fill-in" defects, and 24/180 segments (13%) showed "washout" defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with "fill-in" defects was 9.0 +/- 16.6%, and that of "washout" defects was 24.9 +/- 18.1% which was significantly higher than in controls (8.7 +/- 15.4%, p < 0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion.

  8. Routine delayed voiding cystourethography after initial successful endoscopic treatment with Dextranomer/Hialuronic Acid Copolimer (Dx/HA) of vesicoureteral reflux (VUR). Is it necessary?

    Science.gov (United States)

    García-Aparicio, L; Blázquez-Gómez, E; Vila Santandreu, A; Camacho Diaz, J A; Vila-Cots, J; Ramos Cebrian, M; de Haro, I; Martin, O; Tarrado, X

    2016-12-01

    Some guidelines recommend an early voiding cystourethrography (VCUG) after endoscopic treatment of vesicoureteral reflux (VUR), but there's no consensus if it's necessary a long-term follow-up in these patients. The aim of our study is analyze if it's necessary a delayed VCUG after initial successful treatment with Dx/HA. We have reviewed all medical charts of patients that underwent Dx/HA treatment from 2006 to 2010. We have selected patients with initial successful treatment and more than 3 years of radiological and clinical follow-up. We have analyzed late clinical and radiological outcomes. One hundred and sixty children with 228 refluxing ureters underwent Dx/HA endoscopic treatment with a mean follow-up of 52.13 months. Early VCUG was performed in 215 ureters with an initial successful rate of 84.1%. The group of study was 94/215 ureters with more than 3 years of follow-up with a delayed VCUG. VUR was still resolved in 79,8% of the ureters. Clinical success rate was 91.7%. The incidence of febrile urinary tract infection in those patients with cured VUR and those with a relapsed VUR was 8 and 15%, respectively; but there were no significant differences. We have not found any variable related with relapsed VUR except those ureters that initially received 2 injections (P<.05). If our objective in the treatment of VUR is to reduce the incidence of febrile urinary tract infection it is not necessary to perform a delayed VCUG even though the long-term radiological outcomes is worse than clinical outcome. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Estimating the state of a geophysical system with sparse observations: time delay methods to achieve accurate initial states for prediction

    Science.gov (United States)

    An, Zhe; Rey, Daniel; Ye, Jingxin; Abarbanel, Henry D. I.

    2017-01-01

    The problem of forecasting the behavior of a complex dynamical system through analysis of observational time-series data becomes difficult when the system expresses chaotic behavior and the measurements are sparse, in both space and/or time. Despite the fact that this situation is quite typical across many fields, including numerical weather prediction, the issue of whether the available observations are "sufficient" for generating successful forecasts is still not well understood. An analysis by Whartenby et al. (2013) found that in the context of the nonlinear shallow water equations on a β plane, standard nudging techniques require observing approximately 70 % of the full set of state variables. Here we examine the same system using a method introduced by Rey et al. (2014a), which generalizes standard nudging methods to utilize time delayed measurements. We show that in certain circumstances, it provides a sizable reduction in the number of observations required to construct accurate estimates and high-quality predictions. In particular, we find that this estimate of 70 % can be reduced to about 33 % using time delays, and even further if Lagrangian drifter locations are also used as measurements.

  10. Assessment of circumferential cracks in hypereutectic Al-Si clutch housings

    Directory of Open Access Journals (Sweden)

    M. Haghshenas

    2017-04-01

    Full Text Available As in situ natural composites with silicon phase acting as the reinforcing phase, Al-Si alloys are among most commonly used aluminum alloys in automotive applications (i.e. engine component. Silicon contributes to the strength of Al-Si alloys through load transfer from the Al matrix to the hard (rigid Si phase in the microstructure (load-carrying capacity. Casting parameters (i.e. solidification rate, elemental segregation, secondary dendrite spacing… as well as the size and distribution of the microstructural constituents in Al-Si alloys (i.e. morphology of Si particles, intermetallic compounds, secondary dendrite spacing contribute directly to the mechanical response and failure (or fracture behavior of the alloy within the service. In hyper-eutectic Al-Si alloys (i.e. B390.0, distribution of coarse pre-eutectic Si particle mainly contribute to stress concentration, crack initiation and propagation during the actual service condition. In the present paper, the parameters contribution to the formation of the circumferential cracks in clutch housings made of die cast hyper-eutectics B390.0 Al-Si alloys are assessed through optical microscopy and scanning electron microscopy. Casting variable, cooling rate, their effect on the cracks as well some of the possible causes are also discussed in detail.

  11. A novel design procedure for tractor clutch fingers by using optimization and response surface methods

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, Oguz; Karpat, Fatih; Yuce, Celalettin; Kaya, Necmettin; Yavuz, Nurettin [Uludag University, Gorukle (Turkmenistan); Sen, Hasan [Valeo A. S., Bursa (Turkmenistan)

    2016-06-15

    This paper presents a methodology for re-designing a failed tractor transmission component subjected to cyclic loading. Unlike other vehicles, tractors cope with tough working conditions. Thus, it is necessary to re-design components by using modern optimization techniques. To extend their service life, we present a design methodology for a failed tractor clutch power take-off finger. The finger was completely re-designed using topology and shape optimization approach. Stress-life based fatigue analyses were performed. Shape optimization and response surface methodology were conducted to obtain optimum dimensions of the finger. Two design parameters were selected for the design of experiment method and 15 cases were analyzed. By using design of the experiment method, three responses were obtained: Maximum stresses, mass, and displacement depending on the selected the design parameters. After solving the optimization problem, we achieved a maximum stress and mass reduction of 14% and 6%, respectively. The stiffness was improved up to 31.6% compared to the initial design.

  12. Variation in clutch size in relation to nest size in birds.

    Science.gov (United States)

    Møller, Anders P; Adriaensen, Frank; Artemyev, Alexandr; Bańbura, Jerzy; Barba, Emilio; Biard, Clotilde; Blondel, Jacques; Bouslama, Zihad; Bouvier, Jean-Charles; Camprodon, Jordi; Cecere, Francesco; Charmantier, Anne; Charter, Motti; Cichoń, Mariusz; Cusimano, Camillo; Czeszczewik, Dorota; Demeyrier, Virginie; Doligez, Blandine; Doutrelant, Claire; Dubiec, Anna; Eens, Marcel; Eeva, Tapio; Faivre, Bruno; Ferns, Peter N; Forsman, Jukka T; García-Del-Rey, Eduardo; Goldshtein, Aya; Goodenough, Anne E; Gosler, Andrew G; Góźdź, Iga; Grégoire, Arnaud; Gustafsson, Lars; Hartley, Ian R; Heeb, Philipp; Hinsley, Shelley A; Isenmann, Paul; Jacob, Staffan; Järvinen, Antero; Juškaitis, Rimvydas; Korpimäki, Erkki; Krams, Indrikis; Laaksonen, Toni; Leclercq, Bernard; Lehikoinen, Esa; Loukola, Olli; Lundberg, Arne; Mainwaring, Mark C; Mänd, Raivo; Massa, Bruno; Mazgajski, Tomasz D; Merino, Santiago; Mitrus, Cezary; Mönkkönen, Mikko; Morales-Fernaz, Judith; Morin, Xavier; Nager, Ruedi G; Nilsson, Jan-Åke; Nilsson, Sven G; Norte, Ana C; Orell, Markku; Perret, Philippe; Pimentel, Carla S; Pinxten, Rianne; Priedniece, Ilze; Quidoz, Marie-Claude; Remeš, Vladimir; Richner, Heinz; Robles, Hugo; Rytkönen, Seppo; Senar, Juan Carlos; Seppänen, Janne T; da Silva, Luís P; Slagsvold, Tore; Solonen, Tapio; Sorace, Alberto; Stenning, Martyn J; Török, János; Tryjanowski, Piotr; van Noordwijk, Arie J; von Numers, Mikael; Walankiewicz, Wiesław; Lambrechts, Marcel M

    2014-09-01

    Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited to small-scale studies performed over short time periods. Here, we quantified the relationship between clutch size and nest size, using an exhaustive database of 116 slope estimates based on 17,472 nests of 21 species of hole and non-hole-nesting birds. There was a significant, positive relationship between clutch size and the base area of the nest box or the nest, and this relationship did not differ significantly between open nesting and hole-nesting species. The slope of the relationship showed significant intraspecific and interspecific heterogeneity among four species of secondary hole-nesting species, but also among all 116 slope estimates. The estimated relationship between clutch size and nest box base area in study sites with more than a single size of nest box was not significantly different from the relationship using studies with only a single size of nest box. The slope of the relationship between clutch size and nest base area in different species of birds was significantly negatively related to minimum base area, and less so to maximum base area in a given study. These findings are consistent with the hypothesis that bird species have a general reaction norm reflecting the relationship between nest size and clutch size. Further, they suggest that scientists may influence the clutch size decisions of hole-nesting birds through the provisioning of nest boxes of varying sizes.

  13. Clutch morphology and the timing of exposure impact the susceptibility of aquatic insect eggs to esfenvalerate.

    Science.gov (United States)

    Palmquist, Katherine R; Jenkins, Jeffrey J; Jepson, Paul C

    2008-08-01

    We investigated Baetis spp. (mayfly), Hesperoperla pacifica (stonefly), and Brachycentrus americanus (caddisfly) susceptibility at the egg stage to esfenvalerate, a synthetic pyrethroid insecticide. Eggs were obtained from the field or from field-collected gravid females at sites near Corvallis (OR, USA) and the Metolius River at Camp Sherman (OR, USA) for static exposures under controlled conditions for temperature and light. Eggs were exposed to esfenvalerate for 48 h at concentrations ranging from 0.025 to 4.0 microg/L. No effect on mortality or posthatch growth was detected in H. pacifica eggs exposed to esfenvalerate concentrations up to 1.0 microg/L. Exposure to 0.07 microg/L of esfenvalerate, however, caused a significant increase in Baetis spp. egg mortality, and exposure of near-eclosion eggs to lower concentrations (0.025 and 0.05 microg/L) resulted in behavioral effects and reduced survivorship in newly hatched Baetis nymphs. Early stage B. americanus eggs were 10-fold more sensitive to esfenvalerate when removed from the gelatinous clutch before exposure, an indication that the gelatin affords protection from toxicant exposure. Exposures of near-hatch B. americanus clutches to esfenvalerate concentrations ranging between 0.035 and 0.2 microg/L, however, resulted in significant clutch death within clutches resulting from behavioral aberrations of first-instar larvae. The results of the present study suggest that aquatic insect egg clutch morphology can be a strong influence on susceptibility of embryos to esfenvalerate exposure.

  14. Can exercise ameliorate treatment toxicity during the initial phase of testosterone deprivation in prostate cancer patients? Is this more effective than delayed rehabilitation?

    Directory of Open Access Journals (Sweden)

    Newton Robert U

    2012-09-01

    Full Text Available Abstract Background There has been substantial increase in use of androgen deprivation therapy as adjuvant management of prostate cancer. However, this leads to a range of musculoskeletal toxicities including reduced bone mass and increased skeletal fractures compounded with rapid metabolic alterations, including increased body fat, reduced lean mass, insulin resistance and negative lipoprotein profile, increased incidence of cardiovascular and metabolic morbidity, greater distress and reduced quality of life. Numerous research studies have demonstrated certain exercise prescriptions to be effective at preventing or even reversing these treatment toxicities. However, all interventions to date have been of rehabilitative intent being implemented after a minimum of 3 months since initiation of androgen deprivation, by which time considerable physical and psychological health problems have manifested. The pressing question is whether it is more efficacious to commence exercise therapy at the same time as initiating androgen deprivation, so treatment induced adverse effects can be immediately attenuated or indeed prevented. Methods/design We are proposing a multi-site randomized controlled trial with partial crossover to examine the effects of timing of exercise implementation (immediate or delayed on preserving long-term skeletal health, reversing short- and long-term metabolic and cardiovascular risk factors, and supporting mental health in men receiving androgen deprivation therapy. 124 men who are about to initiate androgen deprivation for prostate cancer will be randomized to immediate or delayed groups. Immediate will commence a 6-month exercise program within 7–10 days of their first dose. Delayed will receive usual care for 6 months and then commence the exercise program for 6 months (partial cross-over. Immediate will be free to adopt the lifestyle of their choosing following the initial 6-month intervention. Measurements for primary and

  15. Can exercise ameliorate treatment toxicity during the initial phase of testosterone deprivation in prostate cancer patients? Is this more effective than delayed rehabilitation?

    International Nuclear Information System (INIS)

    Newton, Robert U; Taaffe, Dennis R; Spry, Nigel; Cormie, Prue; Chambers, Suzanne K; Gardiner, Robert A; Shum, David HK; Joseph, David; Galvão, Daniel A

    2012-01-01

    There has been substantial increase in use of androgen deprivation therapy as adjuvant management of prostate cancer. However, this leads to a range of musculoskeletal toxicities including reduced bone mass and increased skeletal fractures compounded with rapid metabolic alterations, including increased body fat, reduced lean mass, insulin resistance and negative lipoprotein profile, increased incidence of cardiovascular and metabolic morbidity, greater distress and reduced quality of life. Numerous research studies have demonstrated certain exercise prescriptions to be effective at preventing or even reversing these treatment toxicities. However, all interventions to date have been of rehabilitative intent being implemented after a minimum of 3 months since initiation of androgen deprivation, by which time considerable physical and psychological health problems have manifested. The pressing question is whether it is more efficacious to commence exercise therapy at the same time as initiating androgen deprivation, so treatment induced adverse effects can be immediately attenuated or indeed prevented. We are proposing a multi-site randomized controlled trial with partial crossover to examine the effects of timing of exercise implementation (immediate or delayed) on preserving long-term skeletal health, reversing short- and long-term metabolic and cardiovascular risk factors, and supporting mental health in men receiving androgen deprivation therapy. 124 men who are about to initiate androgen deprivation for prostate cancer will be randomized to immediate or delayed groups. Immediate will commence a 6-month exercise program within 7–10 days of their first dose. Delayed will receive usual care for 6 months and then commence the exercise program for 6 months (partial cross-over). Immediate will be free to adopt the lifestyle of their choosing following the initial 6-month intervention. Measurements for primary and secondary endpoints will take place at baseline, 6

  16. Count your eggs before they invade: identifying and quantifying egg clutches of two invasive apple snail species (Pomacea.

    Directory of Open Access Journals (Sweden)

    Colin H Kyle

    Full Text Available Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and

  17. A tale of two pregnancies: A Critical Interpretive Synthesis of women's perceptions about delayed initiation of antenatal care.

    Science.gov (United States)

    Haddrill, Rosalind; Jones, Georgina L; Anumba, Dilly; Mitchell, Caroline

    2017-10-14

    Delayed access to antenatal care in high income countries is associated with poor maternal, fetal and neonatal outcomes. The aim was to synthesise the diverse body of evidence around women's views of early antenatal care and barriers to attendance in such countries. Critical Interpretive Synthesis integrates the process of systematic review with the qualitative methods of meta-ethnography and grounded theory, with a focus on theory generation to inform policy, practice and future research. Database searches were conducted, supplemented with reference and citation tracking and website searching between February 2014 and April 2016. Qualitative data analysis methods were used to extract and summarise the key themes from each study. A taxonomy of constructs was created, with the synthesis developed to thread these together. Fifty-four papers were synthesised, including qualitative, quantitative, mixed method and systematic review, published between 1987 and 2016. Seventeen constructs around the core concept of 'acceptance of personal and public pregnancies' were produced. Acceptance of the 'personal' pregnancy considers the contribution of mindset in the recognition and acceptance of pregnancy, influenced by knowledge of pregnancy symptoms, pregnancy planning and desire. Acceptance of the 'public' pregnancy considers women's assessment of the social consequences of pregnancy, and the relevance and priority of antenatal care. Critical Interpretive Synthesis offers a systematic yet creative approach to the synthesis of diverse evidence. The findings offer new perspectives on women's perceptions of early pregnancy and attendance for care, which may be used to facilitate timely antenatal provision for all pregnant women. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  18. Clutch pressure estimation for a power-split hybrid transmission using nonlinear robust observer

    Science.gov (United States)

    Zhou, Bin; Zhang, Jianwu; Gao, Ji; Yu, Haisheng; Liu, Dong

    2018-06-01

    For a power-split hybrid transmission, using the brake clutch to realize the transition from electric drive mode to hybrid drive mode is an available strategy. Since the pressure information of the brake clutch is essential for the mode transition control, this research designs a nonlinear robust reduced-order observer to estimate the brake clutch pressure. Model uncertainties or disturbances are considered as additional inputs, thus the observer is designed in order that the error dynamics is input-to-state stable. The nonlinear characteristics of the system are expressed as the lookup tables in the observer. Moreover, the gain matrix of the observer is solved by two optimization procedures under the constraints of the linear matrix inequalities. The proposed observer is validated by offline simulation and online test, the results have shown that the observer achieves significant performance during the mode transition, as the estimation error is within a reasonable range, more importantly, it is asymptotically stable.

  19. Lubricant flow analysis for effective lubrication of tractor forward/reverse clutch

    Directory of Open Access Journals (Sweden)

    Daekyung Noh

    2017-04-01

    Full Text Available Owing to the high power requirements of tractors, their low-power transmission gears often experience durability problems such as burning of the clutch. The operation of tractors under high load conditions also causes clutch slip, with the consequent longer operation duration exacerbating the burning of the friction plate. Solving this problem requires effective lubricant distribution. This was achieved in the present study by the development of an analysis model for predicting the lubricant flow rate. The reliability of the model was verified by comparing its predictions for various operation conditions with experimental measurements. Using the model, it was determined that effective distribution of the lubricant could be achieved without significant modification of the system, by only adjusting the gaps between the clutch piston and the housing, and between the separation plates and the case. Keywords: Mechanical engineering

  20. Identification of Flaws Responsible for Crack Initiation and Micromechanisms of Slow Crack Growth in the Delayed Fracture of Alumina.

    Science.gov (United States)

    1982-02-01

    A-"AIS012 CALIFORNIA UNdIV LOS ANSELES DEPT OF MATERIALS SCIEN--ETC F/S 11/6 IDENTIFICATION OF FLAWS RESPONSIBLE FOR CRACK INITIATION AM %I--ETC(U...Sines and Adams . 71 It might be thought that other compressive loading devices could serve the same purpoee. For example, a spherical joint instead of the...compressive strength can be 18 times the tensile strength as reported by Adams . 92 This is because the established criteria are damage criter- ia, not

  1. Regional drivers of clutch loss reveal important trade-offs for beach-nesting birds.

    Science.gov (United States)

    Maslo, Brooke; Schlacher, Thomas A; Weston, Michael A; Huijbers, Chantal M; Anderson, Chris; Gilby, Ben L; Olds, Andrew D; Connolly, Rod M; Schoeman, David S

    2016-01-01

    Coastal birds are critical ecosystem constituents on sandy shores, yet are threatened by depressed reproductive success resulting from direct and indirect anthropogenic and natural pressures. Few studies examine clutch fate across the wide range of environments experienced by birds; instead, most focus at the small site scale. We examine survival of model shorebird clutches as an index of true clutch survival at a regional scale (∼200 km), encompassing a variety of geomorphologies, predator communities, and human use regimes in southeast Queensland, Australia. Of the 132 model nests deployed and monitored with cameras, 45 (34%) survived the experimental exposure period. Thirty-five (27%) were lost to flooding, 32 (24%) were depredated, nine (7%) buried by sand, seven (5%) destroyed by people, three (2%) failed by unknown causes, and one (1%) was destroyed by a dog. Clutch fate differed substantially among regions, particularly with respect to losses from flooding and predation. 'Topographic' exposure was the main driver of mortality of nests placed close to the drift line near the base of dunes, which were lost to waves (particularly during storms) and to a lesser extent depredation. Predators determined the fate of clutches not lost to waves, with the depredation probability largely influenced by region. Depredation probability declined as nests were backed by higher dunes and were placed closer to vegetation. This study emphasizes the scale at which clutch fate and survival varies within a regional context, the prominence of corvids as egg predators, the significant role of flooding as a source of nest loss, and the multiple trade-offs faced by beach-nesting birds and those that manage them.

  2. Regional drivers of clutch loss reveal important trade-offs for beach-nesting birds

    Directory of Open Access Journals (Sweden)

    Brooke Maslo

    2016-09-01

    Full Text Available Coastal birds are critical ecosystem constituents on sandy shores, yet are threatened by depressed reproductive success resulting from direct and indirect anthropogenic and natural pressures. Few studies examine clutch fate across the wide range of environments experienced by birds; instead, most focus at the small site scale. We examine survival of model shorebird clutches as an index of true clutch survival at a regional scale (∼200 km, encompassing a variety of geomorphologies, predator communities, and human use regimes in southeast Queensland, Australia. Of the 132 model nests deployed and monitored with cameras, 45 (34% survived the experimental exposure period. Thirty-five (27% were lost to flooding, 32 (24% were depredated, nine (7% buried by sand, seven (5% destroyed by people, three (2% failed by unknown causes, and one (1% was destroyed by a dog. Clutch fate differed substantially among regions, particularly with respect to losses from flooding and predation. ‘Topographic’ exposure was the main driver of mortality of nests placed close to the drift line near the base of dunes, which were lost to waves (particularly during storms and to a lesser extent depredation. Predators determined the fate of clutches not lost to waves, with the depredation probability largely influenced by region. Depredation probability declined as nests were backed by higher dunes and were placed closer to vegetation. This study emphasizes the scale at which clutch fate and survival varies within a regional context, the prominence of corvids as egg predators, the significant role of flooding as a source of nest loss, and the multiple trade-offs faced by beach-nesting birds and those that manage them.

  3. Predictors of Delayed Antiretroviral Therapy Initiation, Mortality, and Loss to Followup in HIV Infected Patients Eligible for HIV Treatment: Data from an HIV Cohort Study in India

    Directory of Open Access Journals (Sweden)

    Gerardo Alvarez-Uria

    2013-01-01

    Full Text Available Studies from Sub-Saharan Africa have shown that a substantial number of HIV patients eligible for antiretroviral therapy (ART do not start treatment. However, data from other low- or middle-income countries are scarce. In this study, we describe the outcomes of 4105 HIV patients who became ART eligible from January 2007 to November 2011 in an HIV cohort study in India. After three years of ART eligibility, 78.4% started ART, 9.3% died before ART initiation, and 10.3% were lost to followup. Diagnosis of tuberculosis, being homeless, lower CD4 count, longer duration of pre-ART care, belonging to a disadvantaged community, being widowed, and not living near a town were associated with delayed ART initiation. Diagnosis of tuberculosis, being homeless, lower CD4 count, shorter duration of pre-ART care, belonging to a disadvantaged community, illiteracy, and age >45 years were associated with mortality. Being homeless, being single, not living near a town, having a CD4 count <150 cells/μL, and shorter duration of pre-ART care were associated with loss to followup. These results highlight the need to improve the timely initiation of ART in HIV programmes in India, especially in ART eligible patients with tuberculosis, low CD4 counts, living in rural areas, or having a low socioeconomic status.

  4. A comparison of the smeared-dislocation and super-dislocation description of a hydrided region in the context of modelling delayed hydride cracking initiation

    International Nuclear Information System (INIS)

    Smith, E.

    1994-01-01

    In quantifying the stress distribution within a hydrided region in the context of modelling delayed hydride cracking (DHC) initiation in zirconium alloys, this paper highlights the desirability of accounting for image effects, i.e. the interaction between the hydrided region and any free surface, for example a sharp crack, blunt notch or planar surface. The super-dislocation representation of a finite thickness hydrided region is ideal for accounting for image effects. It also adequately accounts for the finite thickness, t, of a hydrided region provided, as is the case in practice, we are concerned with the stress value within the hydride at distances ≥ 0.25 t from an end of the region. (Author)

  5. Overexpression of eIF5 or its protein mimic 5MP perturbs eIF2 function and induces ATF4 translation through delayed re-initiation.

    Science.gov (United States)

    Kozel, Caitlin; Thompson, Brytteny; Hustak, Samantha; Moore, Chelsea; Nakashima, Akio; Singh, Chingakham Ranjit; Reid, Megan; Cox, Christian; Papadopoulos, Evangelos; Luna, Rafael E; Anderson, Abbey; Tagami, Hideaki; Hiraishi, Hiroyuki; Slone, Emily Archer; Yoshino, Ken-Ichi; Asano, Masayo; Gillaspie, Sarah; Nietfeld, Jerome; Perchellet, Jean-Pierre; Rothenburg, Stefan; Masai, Hisao; Wagner, Gerhard; Beeser, Alexander; Kikkawa, Ushio; Fleming, Sherry D; Asano, Katsura

    2016-10-14

    ATF4 is a pro-oncogenic transcription factor whose translation is activated by eIF2 phosphorylation through delayed re-initiation involving two uORFs in the mRNA leader. However, in yeast, the effect of eIF2 phosphorylation can be mimicked by eIF5 overexpression, which turns eIF5 into translational inhibitor, thereby promoting translation of GCN4, the yeast ATF4 equivalent. Furthermore, regulatory protein termed eIF5-mimic protein (5MP) can bind eIF2 and inhibit general translation. Here, we show that 5MP1 overexpression in human cells leads to strong formation of 5MP1:eIF2 complex, nearly comparable to that of eIF5:eIF2 complex produced by eIF5 overexpression. Overexpression of eIF5, 5MP1 and 5MP2, the second human paralog, promotes ATF4 expression in certain types of human cells including fibrosarcoma. 5MP overexpression also induces ATF4 expression in Drosophila The knockdown of 5MP1 in fibrosarcoma attenuates ATF4 expression and its tumor formation on nude mice. Since 5MP2 is overproduced in salivary mucoepidermoid carcinoma, we propose that overexpression of eIF5 and 5MP induces translation of ATF4 and potentially other genes with uORFs in their mRNA leaders through delayed re-initiation, thereby enhancing the survival of normal and cancer cells under stress conditions. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Delayed reproduction of translocated red-cockaded woodpeckers

    Science.gov (United States)

    James R. McCormick; Richard N. Conner; Daniel Saenz; Brent Burt

    2001-01-01

    Twelve pairs of Red-cockaded Woodpeckers were translocated to the Angelina National Forest from 21 October 1998 to 17 December 1998. Five breeding pairs (consisting of at least one trnnslocated bird) produced eggs/nestlings within the first breeding season after translocation. Clutch initiation dates for all five pairs were later than those of resident breeders. The...

  7. Wheeled Vehicle Clutches, Transmissions, and Transfers. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle clutches, transmissions, and transfer cases. It provides the basic…

  8. Clutch size and parental effort in the Great Tit Parus major

    NARCIS (Netherlands)

    Verhulst, S.; Tinbergen, J.M.

    1997-01-01

    We experimentally reduced clutch size of Great Tits Parus major to investigate the effects on parental care (including Daily Energy Expenditure, DEE, measured with doubly labelled water), and the relationship between DEE and the residual reproductive value. The length of a working day was not

  9. Multiple breeding in the Great Tit, II. The costs of rearing a second clutch

    NARCIS (Netherlands)

    Verhulst, S.

    1998-01-01

    1. Multiple breeding (raising more than one batch of young per breeding season) is a common life-history tactic, but little is known as yet of the accompanying costs and benefits. Second clutches of Great Tits, a facultative multiple breeder, were removed over three years to investigate the costs of

  10. Multiple breeding in the Great Tit, II. The costs of rearing a second clutch

    NARCIS (Netherlands)

    Verhulst, S

    1. Multiple breeding (raising more than one batch of young per breeding season) is a common life-history tactic, but little is known as yet of the accompanying costs and benefits. Second clutches of Great Tits, a facultative multiple breeder, were removed over three years to investigate the costs of

  11. Life-history and ecological correlates of geographic variation in egg and clutch mass among passerine species

    Science.gov (United States)

    Martin, T.E.; Bassar, R.D.; Bassar, S.K.; Fontaine, J.J.; Lloyd, P.; Mathewson, Heather A.; Niklison, Alina M.; Chalfoun, A.

    2006-01-01

    Broad geographic patterns in egg and clutch mass are poorly described, and potential causes of variation remain largely unexamined. We describe interspecific variation in avian egg and clutch mass within and among diverse geographic regions and explore hypotheses related to allometry, clutch size, nest predation, adult mortality, and parental care as correlates and possible explanations of variation. We studied 74 species of Passeriformes at four latitudes on three continents: the north temperate United States, tropical Venezuela, subtropical Argentina, and south temperate South Africa. Egg and clutch mass increased with adult body mass in all locations, but differed among locations for the same body mass, demonstrating that egg and clutch mass have evolved to some extent independent of body mass among regions. A major portion of egg mass variation was explained by an inverse relationship with clutch size within and among regions, as predicted by life-history theory. However, clutch size did not explain all geographic differences in egg mass; eggs were smallest in South Africa despite small clutch sizes. These small eggs might be explained by high nest predation rates in South Africa; life-history theory predicts reduced reproductive effort under high risk of offspring mortality. This prediction was supported for clutch mass, which was inversely related to nest predation but not for egg mass. Nevertheless, clutch mass variation was not fully explained by nest predation, possibly reflecting interacting effects of adult mortality. Tests of the possible effects of nest predation on egg mass were compromised by limited power and by counterposing direct and indirect effects. Finally, components of parental investment, defined as effort per offspring, might be expected to positively coevolve. Indeed, egg mass, but not clutch mass, was greater in species that shared incubation by males and females compared with species in which only females incubate eggs. However, egg and

  12. Dry Friction Clutch Disc of an Automobile under Transient Thermal Load: A Comparison of Friction Lining Materials

    Directory of Open Access Journals (Sweden)

    Ali Anosh

    2017-01-01

    Full Text Available This paper shows the comparison of temperatures produced in a dry friction clutch disc with different materials during a single engagement to assist in clutch plate design and analysis. A study of usage of different materials for friction lining of clutch disc is required, which will provide improved performance and enhanced life. This investigation is modelled mathematically and solved numerically using finite element method. ANSYS® 15.0 is a dedicated finite element package used for determining the temperature distribution across a clutch disc. In the present work, an investigation of a conventionally used harmful friction lining material asbestos is compared with carbon-carbon composite, S2-glass fibre and aluminium metal matrix composite. The transient thermal analysis of a clutch disc with different materials is performed and the temperature distribution on the clutch system is compared. Simulation results indicate that all the values of the temperature obtained from the analysis of aluminium metal matrix are less than those of asbestos based lining material, therefore clutch disc made up of aluminium metal matrix composite will assure the extended service life and the longer stability due to the fact that the temperature responsible for the wear and tear has been reduced. Furthermore, the slipping time is also considered in this investigation.

  13. Paternal care and male mate-attraction effort in the European starling is adjusted to clutch size.

    Science.gov (United States)

    Komdeur, Jan; Wiersma, Popko; Magrath, Michael

    2002-06-22

    In facultative polygynous birds with biparental care, a trade-off may occur between male parental care and attraction of additional mates. If there is a cost associated with reduced male parental care, the relative benefit of mate attraction may be predicted to decrease as the size of a male's clutch or brood increases. We tested this prediction in monogamous pairs of facultatively polygynous European starlings (Sturnus vulgaris). The larger the clutch, the more time the male spent incubating and the less time he spent attracting an additional female (i.e. singing near and carrying green nesting material into adjacent empty nest-boxes). Reduced paternal incubation resulted in lower overall incubation (the female did not compensate) and lower hatching success. Immediately after experimental reduction of clutches, males spent significantly less time incubating and more time singing and carrying greenery, and vice versa for experimentally enlarged clutches. Males with experimentally reduced clutches attracted a second female more often than males with experimentally enlarged clutches. This is the first study, to our knowledge, to provide experimental evidence for an adjustment of paternal care and male mate-attraction effort to clutch size. However, a trade-off between paternal nestling provisioning and mate attraction was not revealed, probably due to the absence of unpaired females by that time in the breeding season. Experiments showed that the relative contribution of the male and female to nestling provisioning was unrelated to brood size.

  14. Natural selection and inheritance of breeding time and clutch size in the collared flycatcher.

    Science.gov (United States)

    Sheldon, B C; Kruuk, L E B; Merilä, J

    2003-02-01

    Many characteristics of organisms in free-living populations appear to be under directional selection, possess additive genetic variance, and yet show no evolutionary response to selection. Avian breeding time and clutch size are often-cited examples of such characters. We report analyses of inheritance of, and selection on, these traits in a long-term study of a wild population of the collared flycatcher Ficedula albicollis. We used mixed model analysis with REML estimation ("animal models") to make full use of the information in complex multigenerational pedigrees. Heritability of laying date, but not clutch size, was lower than that estimated previously using parent-offspring regressions, although for both traits there was evidence of substantial additive genetic variance (h2 = 0.19 and 0.29, respectively). Laying date and clutch size were negatively genetically correlated (rA = -0.41 +/- 0.09), implying that selection on one of the traits would cause a correlated response in the other, but there was little evidence to suggest that evolution of either trait would be constrained by correlations with other phenotypic characters. Analysis of selection on these traits in females revealed consistent strong directional fecundity selection for earlier breeding at the level of the phenotype (beta = -0.28 +/- 0.03), but little evidence for stabilising selection on breeding time. We found no evidence that clutch size was independently under selection. Analysis of fecundity selection on breeding values for laying date, estimated from an animal model, indicated that selection acts directly on additive genetic variance underlying breeding time (beta = -0.20 +/- 0.04), but not on clutch size (beta = 0.03 +/- 0.05). In contrast, selection on laying date via adult female survival fluctuated in sign between years, and was opposite in sign for selection on phenotypes (negative) and breeding values (positive). Our data thus suggest that any evolutionary response to selection on

  15. Induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway delays the initiation but fails to eradicate established murine acute myeloid leukemia.

    Science.gov (United States)

    Jaako, P; Ugale, A; Wahlestedt, M; Velasco-Hernandez, T; Cammenga, J; Lindström, M S; Bryder, D

    2017-01-01

    Mutations resulting in constitutive activation of signaling pathways that regulate ribosome biogenesis are among the most common genetic events in acute myeloid leukemia (AML). However, whether ribosome biogenesis presents as a therapeutic target to treat AML remains unexplored. Perturbations in ribosome biogenesis trigger the 5S ribonucleoprotein particle (RNP)-Mdm2-p53 ribosomal stress pathway, and induction of this pathway has been shown to have therapeutic efficacy in Myc-driven lymphoma. In the current study we address the physiological and therapeutic role of the 5S RNP-Mdm2-p53 pathway in AML. By utilizing mice that have defective ribosome biogenesis due to downregulation of ribosomal protein S19 (Rps19), we demonstrate that induction of the 5S RNP-Mdm2-p53 pathway significantly delays the initiation of AML. However, even a severe Rps19 deficiency that normally results in acute bone marrow failure has no consistent efficacy on already established disease. Finally, by using mice that harbor a mutation in the Mdm2 gene disrupting its binding to 5S RNP, we show that loss of the 5S RNP-Mdm2-p53 pathway is dispensable for development of AML. Our study suggests that induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway holds limited potential as a single-agent therapy in the treatment of AML.

  16. A quasi-experimental evaluation of parents as sexual health educators resulting in delayed sexual initiation and increased access to condoms.

    Science.gov (United States)

    Campero, Lourdes; Walker, Dilys; Atienzo, Erika E; Gutierrez, Juan Pablo

    2011-04-01

    To evaluate the effectiveness of an educational intervention for parents of first year high school students in the State of Morelos, Mexico, whose aim was to impact adolescents' sexual behavior, knowledge and access to contraception. Quasi-experimental prospective study with eleven control and eleven intervention schools using self-administered questionnaires for parents and adolescents pre- and post-intervention. Parent-child dyads in the control and intervention schools were matched according to parents' propensity score; the average treatment effect (ATE) was estimated for adolescent's outcome variables. At follow-up, we found significant differences for adolescents in the intervention schools: 6.8% delayed initiation of sexual intercourse, 14.4% had correct knowledge about emergency contraception (EC), and 164% reported having received condoms from their parents, when comparing with students in control schools. Our results suggest that parent-focused interventions could be an innovative and effective strategy to promote adolescents sexual health. Copyright © 2010 The Association for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  17. Use of statistical models based on radiographic measurements to predict oviposition date and clutch size in rock iguanas (Cyclura nubila)

    International Nuclear Information System (INIS)

    Alberts, A.C.

    1995-01-01

    The ability to noninvasively estimate clutch size and predict oviposition date in reptiles can be useful not only to veterinary clinicians but also to managers of captive collections and field researchers. Measurements of egg size and shape, as well as position of the clutch within the coelomic cavity, were taken from diagnostic radiographs of 20 female Cuban rock iguanas, Cyclura nubila, 81 to 18 days prior to laying. Combined with data on maternal body size, these variables were entered into multiple regression models to predict clutch size and timing of egg laying. The model for clutch size was accurate to 0.53 ± 0.08 eggs, while the model for oviposition date was accurate to 6.22 ± 0.81 days. Equations were generated that should be applicable to this and other large Cyclura species. © 1995 Wiley-Liss, Inc

  18. Temperature and shear rate characteristics of electrorheological gel applied to a clutch

    International Nuclear Information System (INIS)

    Koyanagi, K; Takata, Y; Motoyoshi, T; Oshima, T; Kakinuma, Y; Anzai, H; Sakurai, K

    2013-01-01

    This investigation reports the physical characteristics of electrorheological (ER) gels, which are a type of functional material having controlled surface friction. We previously developed slip clutches using ER gels sandwiched between electrodes, and verified their responses and controllability. We newly report the temperature and shear rate characteristics of ER gel in this study because the input and output electrodes of the clutch continuously slip past each other. While the temperature of ER gels increased when energized, the shear stress hardly changed. Instead, wearing and adaptation to the electrode affect the property. The shear rate hardly affected the shear stress in the high-shear-rate region. Conversely, the shear stress depended on the shear rate in the lower region.

  19. DETERMINATION ANALYSIS OF TEMPERATURE REGIMES, FUNCTIONAL CHARACTERISTICS AND SLIDING CURVES OF A HYDRODYNAMIC CLUTCH

    Directory of Open Access Journals (Sweden)

    Božidar V Krstić

    2010-01-01

    Full Text Available Analysis of output quality of power transmitters is possible in position when characteristics are determined earlier. This is the reason why we focused on determination of these characteristics for a concrete power hydro-transmitter. This means that the investigation task primarily consisted of determination of functional characteristics, defining of the sliding curves and temperature regimes of a concrete hydrodynamic clutch. Results of velocity and pressure field investigations in the working space of this clutch, obtained by use of the same test setup, are the basis for determination and analysis of the functional characteristics, sliding curves and temperature regimes. In this work we also analyzed function of the hydrodynamic transmitter in assembly with an internal combustion engine, as well as a process of acceleration and deceleration of a vehicle with this assembly in it.

  20. Design and control of electromagnetic clutch actuation system for automated manual transmission

    Science.gov (United States)

    Ranjan, Ashish; Prasanth, S.; Cherian, Fenin; Baskar, P.

    2017-11-01

    There is a growing interest towards Automatic Transmission in India as it provides better comfort and drivability. But the high cost of this system is limiting itself to be successful in the Indian markets. Due to this, Automated Manual Transmission (AMT) is considered which provides a better solution towards automation as it enhances the drivability and fuel consumption characteristics of a manual transmission at lower costs. However, torque lag and comfort are major issues with AMT which can be addressed by reducing the shift time. In this paper we describe an Electromagnetic Linear Clutch Actuator as a replacement to current electrohydraulic and electromechanical actuator. A control system for the actuator is presented and a clutch engagement strategy is also implemented which reduces the engagement time to 0.78 seconds while reducing jerk and torque lag. The actuator and control system is simulated on a MATLAB Simulink and agreeable results have been obtained.

  1. Torque Control of a Rehabilitation Teaching Robot Using Magneto-Rheological Fluid Clutches

    Science.gov (United States)

    Hakogi, Hokuto; Ohaba, Motoyoshi; Kuramochi, Naimu; Yano, Hidenori

    A new robot that makes use of MR-fluid clutches for simulating torque is proposed to provide an appropriate device for training physical therapy students in knee-joint rehabilitation. The feeling of torque provided by the robot is expected to correspond to the torque performance obtained by physical therapy experts in a clinical setting. The torque required for knee-joint rehabilitation, which is a function of the rotational angle and the rotational angular velocity of a knee movement, is modeled using a mechanical system composed of typical spring-mass-damper elements. The robot consists of two MR-fluid clutches, two induction motors, and a feedback control system. In the torque experiments, output torque is controlled using the spring and damper coefficients separately. The values of these coefficients are determined experimentally. The experimental results show that the robot would be suitable for training physical therapy students to experience similar torque feelings as needed in a clinical situation.

  2. Variation in clutch size in relation to nest size in birds

    OpenAIRE

    Moller Anders P.; Adriaensen Frank; Artemyev Alexandr; Banbura Jerzy; Barba Emilio; Biard Clotilde; Blondel Jacques; Bouslama Zihad; Bouvier Jean-Charles; Camprodon Jordi; Cecere Francesco; Charmantier Anne; Charter Motti; Cichon Mariusz; Cusimano Camillo

    2014-01-01

    © 2014 The Authors. Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited...

  3. Condition-dependent clutch desertion in Great Tit (Parus major) females subjected to human disturbance

    OpenAIRE

    2011-01-01

    Abstract Nest desertion behaviour in relation to body condition and timing of breeding was studied in Great Tit (Parus major) females during two breeding seasons. Desertion, most likely unintentionally provoked by catching females during the incubation period, occurred at a very high rate with 41.2 and 25.6% of deserted first clutches in the two study years. The association between desertion probability, body condition (index calculated as residuals from the regression of body mass...

  4. Volume of eggs in the clutches of Grass snake Natrix natrix and Dice snake N. tessellata: error correction

    Directory of Open Access Journals (Sweden)

    Klenina Anastasiya Aleksandrovna

    2015-12-01

    Full Text Available The authors have made a mistake in calculating the volume of eggs in the clutches of snake family Natrix. In this article we correct the error. As a result, it was revealed, that the volume of eggs positively correlates with a female length and its mass, as well as with the quantity of eggs in the clutches. There is a positive correlation between the characteristics of newborn snakes (length and mass and the volume of eggs, from which they hatched.

  5. Infanticide and within-clutch competition select for reproductive synchrony in a cooperative bird.

    Science.gov (United States)

    Riehl, Christina

    2016-08-01

    Reproduction among members of social animal groups is often highly synchronized, but neither the selective advantages nor the proximate causes of synchrony are fully understood. Here I investigate the evolution of hatching synchrony in the Greater Ani (Crotophaga major), a communally nesting bird in which several unrelated females contribute eggs to a large, shared clutch. Hatching synchrony is variable, ranging from complete synchrony to moderate asynchrony, and is determined by the onset of incubation of the communal clutch. Data from a 10-year field study indicate that individual reproductive success is highest in synchronous groups, and that nestlings that hatch in the middle of the hatching sequence are most likely to survive. Nestling mortality is high in asynchronous clutches because early-hatching nestlings are more likely to be killed by adult group members, whereas late-hatching nestlings are more likely to starve due competition with their older nest-mates. Therefore, the timing of hatching appears to be under stabilizing selection from infanticide and resource competition acting in concert. These results provide empirical support for models predicting that synchrony may evolve as an adaptive counter-strategy to infanticide, and they highlight the importance of competition in shaping the timing of reproduction in social groups. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  6. Dynamic Temperature Rise Mechanism and Some Controlling Factors of Wet Clutch Engagement

    Directory of Open Access Journals (Sweden)

    Zhang Zhigang

    2016-01-01

    Full Text Available The friction transmission model of wet clutch is established to analyze the friction transmission mechanism of its engagement. The model is developed by applying both the average flow model and the elastic contact model between the friction disk and separator plate. The key components during wet clutch engagement are the separator plate, friction disk, and lubricant. The one-dimension transient models of heat transfer in radial direction for the three components are built on the basis of the heat transfer theory and the conservation law of energy. The friction transmission model and transient heat transfer models are coupled and solved by using the Runge-Kutta numerical method, and the radial temperature distribution and their detailed parametric study for the three components are conducted separately. The simulation results show that the radial temperature for the three components rises with the increase of radius in engagement. The changes in engagement pressure, lubricant viscosity, friction lining permeability, combined surface roughness RMS, equivalent elasticity modulus, difference between dynamic and static friction coefficients, and lubricant flow have important influence on the temperature rise characteristics. The proposed models can get better understanding of the dynamic temperature rise characteristics of wet clutch engagement.

  7. Optimal control of the gear shifting process for shift smoothness in dual-clutch transmissions

    Science.gov (United States)

    Li, Guoqiang; Görges, Daniel

    2018-03-01

    The control of the transmission system in vehicles is significant for the driving comfort. In order to design a controller for smooth shifting and comfortable driving, a dynamic model of a dual-clutch transmission is presented in this paper. A finite-time linear quadratic regulator is proposed for the optimal control of the two friction clutches in the torque phase for the upshift process. An integral linear quadratic regulator is introduced to regulate the relative speed difference between the engine and the slipping clutch under the optimization of the input torque during the inertia phase. The control objective focuses on smoothing the upshift process so as to improve the driving comfort. Considering the available sensors in vehicles for feedback control, an observer design is presented to track the immeasurable variables. Simulation results show that the jerk can be reduced both in the torque phase and inertia phase, indicating good shift performance. Furthermore, compared with conventional controllers for the upshift process, the proposed control method can reduce shift jerk and improve shift quality.

  8. The Role of Counter-Face Roughness on the Tribological Performance of a Clutch System Tested with a Pin-On-Disc Tribometer

    Directory of Open Access Journals (Sweden)

    Graciliano Fernandes

    2016-05-01

    Full Text Available This study was a continuous investigation of the roles played by the tribofilm on dry automotive clutch system performance. Tribological experiments were performed by the addition of wear debris at the beginning of tribometer tests and by reducing the surface roughness of a cast iron counter-face. The initial surface conditions of cast discs were 0.2 and 1.2 µm. The pin-on-disc tests were carried out at three different PV levels: 3.08, 7.88, and 10.09 MPa·ms−1, and the current results were correlated to those previously obtained in the standard tribometer procedure. When the wear debris was added into the tribosystem, the friction coefficient level dropped drastically while the assembly wear rate rose. In contrast, the modified cast discs provided a reduced wear rate of assembly and a higher and more stable friction coefficient level. These improvements were obtained in a severe condition where higher temperature levels were reached. For the tests with added debris, SEM observations revealed a more intense tribofilm development over the worn surfaces of the clutch friction material. The smoothest cast disc did not damage the developed tribofilms and maintained them more stably due to a reduction in contact area stresses at the highest tribometer test.

  9. Evolution of avian clutch size along latitudinal gradients: do seasonality, nest predation or breeding season length matter?

    Science.gov (United States)

    Griebeler, E M; Caprano, T; Böhning-Gaese, K

    2010-05-01

    Birds display a latitudinal gradient in clutch size with smaller clutches in the tropics and larger in the temperate region. Three factors have been proposed to affect this pattern: seasonality of resources (SR), nest predation and length of the breeding season (LBS). Here, we test the importance of these factors by modelling clutch size evolution within bird populations under different environmental settings. We use an individual-based ecogenetic simulation model that combines principles from population ecology and life history theory. Results suggest that increasing SR from the tropics to the poles by itself or in combination with a decreasing predation rate and LBS can generate the latitudinal gradient in clutch size. Annual fecundity increases and annual adult survival rate decreases from the tropics to the poles. We further show that the annual number of breeding attempts that (together with clutch size) determines total annual egg production is an important trait to understand latitudinal patterns in these life history characteristics. Field experiments that manipulate environmental factors have to record effects not only on clutch size, but also on annual number of breeding attempts. We use our model to predict the outcome of such experiments under different environmental settings.

  10. Delay of insulin initiation in patients with type 2 diabetes mellitus inadequately controlled with oral hypoglycemic agents (analysis of patient- and physician-related factors): A prospective observational DIPP-FACTOR study in Korea.

    Science.gov (United States)

    Kim, Sin Gon; Kim, Nam Hoon; Ku, Bon Jeong; Shon, Ho Sang; Kim, Doo Man; Park, Tae Sun; Kim, Yong-Seong; Kim, In Joo; Choi, Dong Seop

    2017-05-01

    To assess the time to initiation of insulin therapy, and concurrently investigate both patient- and physician-related factors associated with delaying insulin therapy in Korean patients with type 2 diabetes uncontrolled by oral hypoglycemic agents (OHAs). This prospective, observational disease registry study was carried out across 69 centers in Korea. Type 2 diabetes patients who had received two or more OHAs within the past 5 years, had a glycated hemoglobin ≥8% in the past 6 months and had not received insulin were included. Data recorded on data collection forms during a 12-month period were analyzed. Of 2168 patients enrolled, 1959 were evaluated and classified as the insulin-initiated or insulin-delayed group. Insulin was prescribed for just 20% of the patients during a 1-year follow-up period, and less than half (44.5%) of the patients who were taking two OHAs started insulin after 6 years. Patient-related factors for delay in insulin initiation included older age, shorter duration of diabetes and lower glycated hemoglobin. Physician-related factors included age (~50 to 1000) of patients consulted per month. Patient refusal (33.6%) and physicians' concerns of patient non-compliance (26.5%) were the major physician-reported reasons for delaying insulin therapy. Inconvenience of insulin therapy (51.6%) and fear of injection (48.2%) were the major reasons for patient refusal. Insulin initiation is delayed in patients with type 2 diabetes uncontrolled by two or more OHAs in Korea. Patient- and physician-related factors associated with this delay need to be addressed for better diabetes management. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  11. Different temperature and cooling patterns at the blunt and sharp egg poles reflect the arrangement of eggs in an avian clutch.

    Science.gov (United States)

    Šálek, Miroslav E; Zárybnická, Markéta

    2015-01-01

    Incubation is an energetically demanding process during which birds apply heat to their eggs to ensure embryonic development. Parent behaviours such as egg turning and exchanging the outer and central eggs in the nest cup affect the amount of heat lost to the environment from individual eggs. Little is known, however, about whether and how egg surface temperature and cooling rates vary among the different areas of an egg and how the arrangement of eggs within the clutch influences heat loss. We performed laboratory (using Japanese quail eggs) and field (with northern lapwing eggs) experiments using infrared imaging to assess the temperature and cooling patterns of heated eggs and clutches. We found that (i) the sharp poles of individual quail eggs warmed to a higher egg surface temperature than did the blunt poles, resulting in faster cooling at the sharp poles compared to the blunt poles; (ii) both quail and lapwing clutches with the sharp poles oriented towards the clutch centre (arranged clutches) maintained higher temperatures over the central part of the clutch than occurred in those clutches where most of the sharp egg poles were oriented towards the exterior (scattered clutches); and (iii) the arranged clutches of both quail and lapwing showed slower cooling rates at both the inner and outer clutch positions than did the respective parts of scattered clutches. Our results demonstrate that egg surface temperature and cooling rates differ between the sharp and blunt poles of the egg and that the orientation of individual eggs within the nest cup can significantly affect cooling of the clutch as a whole. We suggest that birds can arrange their eggs within the nest cup to optimise thermoregulation of the clutch.

  12. Acute poisoning following ingestion of medicines: initial management. How to treat life-threatening complications and to evaluate the risk of delayed effects and psychological distress.

    Science.gov (United States)

    2010-12-01

    activated charcoal, provided the patient is fully conscious and capable of swallowing safely. Gastric lavage carries a risk of serious adverse effects. It is only justified in the rare cases in which the patient's life is at risk following ingestion of a drug that is not adsorbed by activated charcoal. Ipecac syrup should not be used under any circumstances. Purging and gastric lavage are not part of initial management. Few antidotes are suitable for use in the early stages of poisoning. Acetylcysteine can be used for some cases of paracetamol poisoning, and naloxone for some types of opioid poisoning. Paracetamol poisoning can cause life-threatening hepatocellular necrosis. Activated charcoal should be administered as soon as possible. Acetylcysteine protects the liver when administered within 24 hours after paracetamol ingestion. Paracetamol serum assay can be useful for guiding patient management. In practice, acetylcysteine should be given when access to emergency medical intervention is not feasible within 8 to 10 hours after paracetamol ingestion. Intravenous naloxone is useful for respiratory depression due to opioid poisoning, but its duration of action is often shorter than that of opioids, making continuous monitoring necessary. Hospital monitoring is warranted in case of potentially severe poisoning; this includes patients at increased risk, patients having taken a potentially lethal substance at a toxic or unknown dose. Some pharmacological substances and formulations can have delayed effects. In case of self-poisoning, the risk of short-term relapse should be evaluated, even when the patient's condition is not life-threatening. Hospital admission should be proposed, or sometimes imposed, until the acute risk of suicide has subsided. In practice, when faced with acute drug poisoning, the first step is to implement life-support measures, to gather and communicate prognostic information and details of any treatments to the ambulance crew or hospital team.

  13. Performance Investigation of A Mix Wind Turbine Using A Clutch Mechanism At Low Wind Speed Condition

    Science.gov (United States)

    Jamanun, M. J.; Misaran, M. S.; Rahman, M.; Muzammil, W. K.

    2017-07-01

    Wind energy is one of the methods that generates energy from sustainable resources. This technology has gained prominence in this era because it produces no harmful product to the society. There is two fundamental type of wind turbine are generally used this day which is Horizontal axis wind turbine (HAWT) and Vertical axis wind turbine (VAWT). The VAWT technology is more preferable compare to HAWT because it gives better efficiency and cost effectiveness as a whole. However, VAWT is known to have distinct disadvantage compared to HAWT; self-start ability and efficiency at low wind speed condition. Different solution has been proposed to solve these issues which includes custom design blades, variable angle of attack mechanism and mix wind turbine. A new type of clutch device was successfully developed in UMS to be used in a mix Savonius-Darrieus wind turbine configuration. The clutch system which barely audible when in operation compared to a ratchet clutch system interconnects the Savonius and Darrieus rotor; allowing the turbine to self-start at low wind speed condition as opposed to a standalone Darrieus turbine. The Savonius height were varied at three different size in order to understand the effect of the Savonius rotor to the mix wind turbine performance. The experimental result shows that the fabricated Savonius rotor show that the height of the Savonius rotor affecting the RPM for the turbine. The swept area (SA), aspect ratio (AR) and tip speed ratio (TSR) also calculated in this paper. The highest RPM recorded in this study is 90 RPM for Savonius rotor 0.22-meter height at 2.75 m/s. The Savonius rotor 0.22-meter also give the highest TSR for each range of speed from 0.75 m/s, 1.75 m/s and 2.75 m/s where it gives 1.03 TSR, 0.76 TSR, and 0.55 TSR.

  14. Drought-caused delay in nesting of Sonoran Desert birds and its facilitation of parasite- and predator-mediated variation in reproductive success

    Science.gov (United States)

    McCreedy, Chris; van Riper, Charles

    2015-01-01

    As our understanding of climate change has increased, so has our awareness of the impacts of these changes on biotic systems. Climate models are nearly unanimous in their predictions for increased drought frequency in southwestern North America, and delays in nest initiation due to drought may influence nesting success and productivity for many Sonoran Desert bird species. In southeastern California and western Arizona in 2004–2009, we found negative correlations for 13 of 13 species between nest initiation date and rainfall accumulation during the preceding 4-month winter rainy season. Nesting was delayed more than 3 weeks for some species during extreme droughts in 2006 and 2007. During 2004–2009, we found a significant negative effect of nest initiation date on nest survival probability (β̂ = −0.031 ± 0.005 SE, P nesting delay in nesting success and productivity, in 2010 we conducted a manipulative experiment with Black-tailed Gnatcatchers (Polioptila melanura; BTGN) and Verdins (Auriparus flaviceps; VERD). Following a wet winter, we delayed clutch initiation dates for treatment pairs to match first-egg dates that we observed during droughts in 2006 and 2007. Nest initiation date had a significant negative effect on nest survival of both species (BTGN: β̂ = −1.18 ± 0.27 SE, P nest predation and Brown-headed Cowbird (Molothrus ater) parasitism were the most common causes of nest failure, we conclude that the impacts of climate change–caused drought on annual reproductive output in the Sonoran Desert will be further compounded by parasitism and predation for Black-tailed Gnatcatchers and by predation for Verdins.

  15. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  16. Fuzzy Determination of Target Shifting Time and Torque Control of Shifting Phase for Dry Dual Clutch Transmission

    Directory of Open Access Journals (Sweden)

    Zhiguo Zhao

    2014-01-01

    Full Text Available Based on the independently developed five-speed dry dual clutch transmission (DDCT, the paper proposes the torque coordinating control strategy between engine and two clutches, which obtains engine speed and clutch transferred torque in the shifting process, adequately reflecting the driver intention and improving the shifting quality. Five-degree-of-freedom (DOF shifting dynamics model of DDCT with single intermediate shaft is firstly established according to its physical characteristics. Then the quantitative control objectives of the shifting process are presented. The fuzzy decision of shifting time and the model-based torque coordinating control strategy are proposed and also verified by simulating under different driving intentions in up-/downshifting processes with the DCT model established on the MATLAB/Simulink. Simulation results validate that the shifting control algorithm proposed in this paper can not only meet the shifting quality requirements, but also adapt to the various shifting intentions, having a strong robustness.

  17. Design optimization of clutch housing mold by fluid flow and solidification simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, Seyedeh Maryam; Utlu, Zafer [Istanbul Aydin Univ., Istanbul (Turkmenistan)

    2016-06-15

    Aluminum die casting is so complex where flow momentum is critical matter in the mould filling process due the high velocity of the liquid metal. Actually, in complex parts the exact calculation of mould filling performance with using experimental knowledge is almost impossible. Aluminum die castings play a definitive role in the manufacturing of lightweight automobile bodies. Hence it is more essential today that these castings be produced with the high quality methods. In this condition the simulation is becoming more important in the designing procedure. This saves time and reduces the cost of the casting system design, which is an advantage of using simulation programs. Also, economical utilization of materials can be obtained when the quantity of test castings is decreased. This paper describes the advantages of the clutch housing die casting mold simulations to achieve better casting system design in High pressure die castings (HPDC). Filling analysis is used to determine the size and location of the gate as well as proper runner system design for ensuring a complete and balanced filling of the clutch housing part.

  18. Study on Oil Pressure Characteristics and Trajectory Tracking Control in Shift Process of Wet-Clutch for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Junqiu Li

    2016-01-01

    Full Text Available Accurate control of oil pressure of wet-clutch is of great importance for improving shift quality. Based on dynamic models of two-gear planetary transmission and hydraulic control system, a trajectory tracking model of oil pressure was built by sliding mode control method. An experiment was designed to verify the validity of hydraulic control system, through which the relationship between duty cycle of on-off valve and oil pressure of clutch was determined. The tracking effect was analyzed by simulation. Results showed that oil pressure could follow well the optimal trajectory and the shift quality was effectively improved.

  19. Metabolic rate of nocturnal incubation in female great tits, Parus major, in relation to clutch size measured in a natural environment

    NARCIS (Netherlands)

    de Heij, Maaike E.; van der Graaf, Alexandra J.; Hafner, Dennis; Tinbergen, Joost M.

    2007-01-01

    To study the energetic costs of incubation in relation to clutch size, clutch sizes were manipulated and the metabolic rate of female great tits, Parus major (Linnaeus), during nocturnal incubation (MRinc) was measured using mobile oxygen analysers. Individuals were measured on consecutive nights

  20. Density dependence of avian clutch size in resident and migrant species: is there a constraint on the predictability of competitor density?

    NARCIS (Netherlands)

    Both, C.

    2000-01-01

    The presence of density dependence of clutch size is tested in 57 long-term population studies of 10 passerine bird species. In about half of the studies of tit species Parus spp. density dependence of clutch size was found, while none was found in studies of two flycatcher species Ficedula spp. One

  1. Delayed initiation of radiotherapy for glioblastoma: how important is it to push to the front (or the back) of the line?

    Science.gov (United States)

    Lawrence, Yaacov Richard; Blumenthal, Deborah T; Matceyevsky, Diana; Kanner, Andrew A; Bokstein, Felix; Corn, Benjamin W

    2011-10-01

    Glioblastoma is a malignant tumor characterized by a rapid proliferation rate. Contemporary multi-modality treatment consists of maximal surgical resection followed by radiation therapy (RT) combined with cytotoxic chemotherapy. The optimal timing of these different steps is not known. Four studies from the pre-temozolomide era, encompassing a total of 4,584 subjects, have examined the consequences of a delay between resection and starting RT. Whereas the two small single-institution studies found this delay to be detrimental, two large multi-institutional studies found delay to be either slightly beneficial or at least not harmful. Here, we critically compare the methodologies and results presented in these studies, and include a novel analysis of the combined datasets. We conclude that moderate wait periods (up to 4-6 weeks post-operatively) are safe and may be modestly beneficial. Conversely, there is no evidence to justify waiting longer than 6 weeks. Underlying radiobiological principles are discussed.

  2. A study of airborne chrysotile concentrations associated with handling, unpacking, and repacking boxes of automobile clutch discs.

    Science.gov (United States)

    Jiang, George C T; Madl, Amy K; Ingmundson, Kelsey J; Murbach, Dana M; Fehling, Kurt A; Paustenbach, Dennis J; Finley, Brent L

    2008-06-01

    Although automotive friction products (brakes and manual clutches) historically contained chrysotile asbestos, industrial hygiene surveys and epidemiologic studies of auto mechanics have consistently shown that these workers are not at an increased risk of developing asbestos-related diseases. Airborne asbestos levels during brake repair and brake parts handling have been well-characterized, but the potential exposure to airborne asbestos fibers during the handling of clutch parts has not been examined. In this study, breathing zone samples on the lapel of a volunteer worker (n=100) and area samples at bystander (n=50), remote area (n=25), and ambient (n=9) locations collected during the stacking, unpacking, and repacking of boxes of asbestos-containing clutches, and the subsequent cleanup and clothes handling, were analyzed by phase contrast microscopy (PCM) and transmission electron microscopy (TEM). In addition, fiber morphology and size distribution was evaluated using X-ray diffraction, polarized light microscopy, and ISO analytical methods. It was observed that the (1) airborne asbestos concentrations increased with the number of boxes unpacked and repacked, (2) repetitive stacking of unopened boxes of clutches resulted in higher asbestos concentrations than unpacking and repacking the boxes of clutches, (3) cleanup and clothes handling tasks yielded very low asbestos concentrations. Fiber size and morphology analyses showed that amphibole fibers were not detected in the clutches and that the vast majority (>95%) of the airborne chrysotile fibers were less than 20 microm in length. Applying the ratio of asbestos fibers:total fibers (including non-asbestos) as determined by TEM to the PCM results, it was found that 30-min average airborne chrysotile concentrations (PCM adjusted) were 0.026+/-0.004 f/cc or 0.100+/-0.017 f/cc for a worker unpacking and repacking 1 or 2 boxes of clutches, respectively. The 30-min PCM adjusted average airborne asbestos

  3. Delayed power analysis

    International Nuclear Information System (INIS)

    Adamovich, L.A.; Azarov, V.V.

    1999-01-01

    Time dependent core power behavior in a nuclear reactor is described with well-known neutron kinetics equations. At the same time, two portions are distinguished in energy released from uranium nuclei fission; one released directly at fission and another delayed (residual) portion produced during radioactive decay of fission products. While prompt power is definitely described with kinetics equations, the delayed power presentation still remains outstanding. Since in operation the delayed power part is relatively small (about 6%) operation, it can be neglected for small reactivity disturbances assuming that entire power obeys neutron kinetics equations. In case of a high negative reactivity rapidly inserted in core (e.g. reactor scram initiation) the prompt and delayed components can be calculated separately with practically no impact on each other, employing kinetics equations for prompt power and known approximation formulas for delayed portion, named residual in this specific case. Under substantial disturbances the prompt component in the dynamic process becomes commensurable with delayed portion, thus making necessary to take into account their cross impact. A system of differential equations to describe time-dependent behavior of delayed power is presented. Specific NPP analysis shows a way to significantly simplify the task formulation. (author)

  4. Optimal control of mode transition for four-wheel-drive hybrid electric vehicle with dry dual-clutch transmission

    Science.gov (United States)

    Zhao, Zhiguo; Lei, Dan; Chen, Jiayi; Li, Hangyu

    2018-05-01

    When the four-wheel-drive hybrid electric vehicle (HEV) equipped with a dry dual clutch transmission (DCT) is in the mode transition process from pure electrical rear wheel drive to front wheel drive with engine or hybrid drive, the problem of vehicle longitudinal jerk is prominent. A mode transition robust control algorithm which resists external disturbance and model parameter fluctuation has been developed, by taking full advantage of fast and accurate torque (or speed) response of three electrical power sources and getting the clutch of DCT fully involved in the mode transition process. Firstly, models of key components of driveline system have been established, and the model of five-degrees-of-freedom vehicle longitudinal dynamics has been built by using a Uni-Tire model. Next, a multistage optimal control method has been produced to realize the decision of engine torque and clutch-transmitted torque. The sliding-mode control strategy for measurable disturbance has been proposed at the stage of engine speed dragged up. Meanwhile, the double tracking control architecture that integrates the model calculating feedforward control with H∞ robust feedback control has been presented at the stage of speed synchronization. Finally, the results from Matlab/Simulink software and hardware-in-the-loop test both demonstrate that the proposed control strategy for mode transition can not only coordinate the torque among different power sources and clutch while minimizing vehicle longitudinal jerk, but also provide strong robustness to model uncertainties and external disturbance.

  5. Delayed Ejaculation

    Science.gov (United States)

    ... cases, it is due to a combination of physical and psychological concerns. Psychological causes of delayed ejaculation include: Depression, anxiety or other mental health conditions Relationship problems due to stress, poor communication ...

  6. Delayed growth

    Science.gov (United States)

    ... Slow rate of growth; Retarded growth and development; Growth delay Images Toddler development References Cooke DW, Divall SA, Radovick S. Normal and aberrant growth in children. In: Melmed S, Polonsky KS, Larsen PR, ...

  7. Choking vs. clutch performance: a study of sport performance under pressure.

    Science.gov (United States)

    Otten, Mark

    2009-10-01

    Choking research in sport has suggested that an athlete's tendency to choke, versus give a better than usual (i.e., "clutch") performance depends on his or her personality, as well as on situational influences, such as a reliance on explicit (versus implicit) knowledge when pressured. The current study integrated these hypotheses and tested a structural equation model (SEM) to predict sport performance under pressure. Two hundred and one participants attempted two sets of 15 basketball free throws, and were videotaped during their second set of shots as a manipulation of pressure. Results of the model suggest that "reinvesting" attention in the task leads to greater anxiety (cognitive and somatic), which then predicts a higher level of self-focus; self-focus, then, did not lead to improved performance under pressure, whereas feelings of self-reported "perceived control" did help performance. Implications for measurement of these constructs, and their relationships with performance, are discussed.

  8. Nonlinear gearshifts control of dual-clutch transmissions during inertia phase.

    Science.gov (United States)

    Hu, Yunfeng; Tian, Lu; Gao, Bingzhao; Chen, Hong

    2014-07-01

    In this paper, a model-based nonlinear gearshift controller is designed by the backstepping method to improve the shift quality of vehicles with a dual-clutch transmission (DCT). Considering easy-implementation, the controller is rearranged into a concise structure which contains a feedforward control and a feedback control. Then, robustness of the closed-loop error system is discussed in the framework of the input to state stability (ISS) theory, where model uncertainties are considered as the additive disturbance inputs. Furthermore, due to the application of the backstepping method, the closed-loop error system is ordered as a linear system. Using the linear system theory, a guideline for selecting the controller parameters is deduced which could reduce the workload of parameters tuning. Finally, simulation results and Hardware in the Loop (HiL) simulation are presented to validate the effectiveness of the designed controller. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Electronic control of a 4-speed automatic transmission with lock-up clutch

    Energy Technology Data Exchange (ETDEWEB)

    Schwab, M.

    1984-01-01

    The paper describes the electronic control of an automatic 4-speed transmission with lock-up clutch. As compared to purely hydraulically controlled transmissions, this control offers a clearly improved quality of shifting and the possibility of achieving improvements in fuel consumption thanks to a special economy program. The electronic control unit is a Bosch MOTRONIC which has been expanded to include the functions of transmission control. A special feature is the engine torque control which is implemented by way of retarding the ignition when shifting. This opens up an additional degree of freedom for optimizing a transmission in terms of shift comfort, life of the friction elements and the power which can be transmitted.

  10. A force transmission system based on a tulip-shaped electrostatic clutch for haptic display devices

    Science.gov (United States)

    Sasaki, Hikaru; Shikida, Mitsuhiro; Sato, Kazuo

    2006-12-01

    This paper describes a novel type of force transmission system for haptic display devices. The system consists of an array of end-effecter elements, a force/displacement transmitter and a single actuator producing a large force/displacement. It has tulip-shaped electrostatic clutch devices to distribute the force/displacement from the actuator among the individual end effecters. The specifications of three components were determined to stimulate touched human fingers. The components were fabricated by using micro-electromechanical systems and conventional machining technologies, and finally they were assembled by hand. The performance of the assembled transmission system was experimentally examined and it was confirmed that each projection in the arrayed end effecters could be moved individually. The actuator in a system whose total size was only 3.0 cm × 3.0 cm × 4.0 cm produced a 600 mN force and displaced individual array elements by 18 µm.

  11. The Use of Video Modeling with the Picture Exchange Communication System to Increase Independent Communicative Initiations in Preschoolers with Autism and Developmental Delays

    Science.gov (United States)

    Cihak, David F.; Smith, Catherine C.; Cornett, Ashlee; Coleman, Mari Beth

    2012-01-01

    The use of video modeling (VM) procedures in conjunction with the picture exchange communication system (PECS) to increase independent communicative initiations in preschool-age students was evaluated in this study. The four participants were 3-year-old children with limited communication skills prior to the intervention. Two of the students had…

  12. Developmental delay

    Science.gov (United States)

    Nutrition support is essential for the care of the child with developmental delay. After a thorough evaluation, an individualized intervention plan that accounts for the child’s nutrition status, feeding ability, and medical condition may be determined. Nutrition assessments may be performed at leas...

  13. Whittling Down the Wait Time: Exploring Models to Minimize the Delay from Initial Concern to Diagnosis and Treatment of Autism Spectrum Disorder.

    Science.gov (United States)

    Gordon-Lipkin, Eliza; Foster, Jessica; Peacock, Georgina

    2016-10-01

    The process from initial concerns to diagnosis of autism spectrum disorder (ASD) can be a long and complicated process. The traditional model for evaluation and diagnosis of ASD often consists of long wait-lists and evaluations that result in a 2-year difference between the earliest signs of ASD and mean age of diagnosis. Multiple factors contribute to this diagnostic bottleneck, including time-consuming evaluations, cost of care, lack of providers, and lack of comfort of primary care providers to diagnose autism. This article explores innovative clinical models that have been implemented to address this as well as future directions and opportunities. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. On the correlation between the shape of eggs and their quantity in the clutches of Grass snake Natrix natrix (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Klenina Anastasia Alexandrovna

    2014-12-01

    Full Text Available Positive correlation between the quantity of eggs in clutch of the grass snake and their diameter as well as negative correlation between quantity of eggs and their length and between the diameter of eggs and their length was revealed. It was determined that the more the quantity of eggs in the clutch, the more they are rounded, that was explained by their deformation in accumulating in the oviduct.

  15. A Study of Structural Stress Technique for Fracture Prediction of an Auto-Mobile Clutch Snap-Ring

    International Nuclear Information System (INIS)

    Kim, Ju Hee; Myeong, Man Sik; Oh, Chang Sik; Kim, Yun Jae

    2016-01-01

    The endurance reliability assessment of a highly complex mechanism is generally predicted by the fatigue life based on simple stress analysis. This study discusses various fatigue life assessment techniques for an automobile clutch snap ring. Finite element analyses were conducted to determine the structural stress on the snap ring. Structural stress that is insensitive in regards to the mesh size and type definition is presented in this study. The structural stress definition is consistent with elementary structural mechanics theory and provides an effective measure of a stress state that pertains to fatigue behavior of welded joints in the form of both membrane and bending components. Numerical procedures for both solid models and shell or plate element models are presented to demonstrate the mesh-size insensitivity when extracting the structural stress parameters. Conventional finite element models can be used with the structural stress calculations as a post-processing procedure. The two major implications from this research were: (a) structural stresses pertaining to fatigue behavior can be consistently calculated in a mesh-insensitive manner regardless of the types of finite element models; and (b) by comparing with the clutch snap-ring fatigue test data, we should predict the fatigue fractures of an automobile clutch snap ring using this method

  16. Applying Low-Frequency Vibration for the Experimental Investigation of Clutch Hub Forming

    Directory of Open Access Journals (Sweden)

    De’an Meng

    2018-05-01

    Full Text Available A vibration-assisted plastic-forming method was proposed, and its influence on clutch hub forming process was investigated. The experiments were conducted on a vibration-assisted hydraulic extrusion press with adjustable frequency and amplitude. Vibration frequency and amplitude were considered in investigating the effect of vibration on forming load and surface quality. Results showed that applying vibration can effectively reduce forming force and improve surface quality. The drop in forming load was proportional to the vibration frequency and amplitude, and the load decreased by up to 25%. Such reduction in forming load raised with amplitude increase because the increase in amplitude would accelerate punch relative speed, which then weakened the adhesion between workpiece and dies. By increasing the vibration frequency, the punch movement was enhanced, and the number of attempts to drag the lubricant out of the pits was increased. In this manner, the lubrication condition was improved greatly. The 3D surface topography testing confirmed the assumption. Moreover, vibration frequency exerted a more significant effect on the forming load reduction than vibration amplitude.

  17. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    . The underlying reasons for the large variation in the age at pubertal onset are not fully established; however, nutritional status and socioeconomic and environmental factors are known to be influencing, and a significant amount of influencing genetic factors have also been identified. The challenges...... optimal in discriminating especially CDGP from HH. Management of the delayed puberty depends on the etiology. For boys with CDGP an observational period will often reveal imminent puberty. If puberty is not progressing spontaneously, sex steroid replacement is effective in stimulating the development...

  18. Design and analysis of the Gemini chain system in dual clutch transmission of automobile

    Science.gov (United States)

    Cheng, Yabing; Guo, Haitao; Fu, Zhenming; Wan, Nen; Li, Lei; Wang, Yang

    2015-01-01

    Chain drive system is widely used in the conditions of high-speed, overload, variable speed and load. Many studies are focused on the meshing theory and wear characteristics of chain drive system, but system design, analysis, and noise characteristics of the chain drive system are weak. System design and noise characteristic are studied for a new type Gemini chain of dual-clutch automatic transmission. Based on the meshing theory of silent chain, the design parameters of the Gemini chain system are calculated and the mathematical models and dynamic analysis models of the Gemini chain system are established. Dynamic characteristics of the Gemini chain system is simulated and the contact force of plate and pin, plate and sprockets, the chain tension forces, the transmission error and the stress of plates and pins are analyzed. According to the simulation results of the Gemini chain system, the noise experiment about system is carried out. The noise values are tested at different speed and load and spectral characteristics are analyzed. The results of simulation and experimental show that the contact forces of plate and pin, plate and sprockets are smaller than the allowable stress values, the chain tension force is less than ultimate tension and transmission error is limited in 1.2%. The noise values can meet the requirements of industrial design, and it is proved that the design and analysis method of the Gemini chain system is scientific and feasible. The design and test system is built from analysis to test of Gemini chain system. This research presented will provide a corresponding theoretical guidance for the design and dynamic characteristics and noise characteristics of chain drive system.

  19. Ciprofloxacin prophylaxis delays initiation of broad-spectrum antibiotic therapy and reduces the overall use of antimicrobial agents during induction therapy for acute leukaemia: A single-centre study.

    Science.gov (United States)

    Hallböök, Helene; Lidström, Anna-Karin; Pauksens, Karlis

    2016-01-01

    Due to an outbreak of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, the routine use of fluoroquinolone prophylaxis was questioned. As a result, this study was conducted with the aim to evaluate the impact of ciprofloxacin-prophylaxis on the use of broad-spectrum antibioctics and anti-mycotics. A cohort of 139 consecutive patients with acute leukaemia treated with remission-inducing induction chemotherapy between 2004-2012 at the Department of Haematology in Uppsala University Hospital was analysed. Fifty-three patients (38%) received broad-spectrum antibiotics at the initiation of chemotherapy and were not eligible for prophylaxis. Of the remaining patients, the initiation of broad-spectrum antibiotics was delayed by 3 days in those receiving ciprofloxacin prophylaxis (n = 47) compared with those receiving no prophylaxis (n = 39). The median duration of systemic antibiotic treatment was 6 days shorter in patients receiving ciprofloxacin prophylaxis (12 vs 18 days; p = 0.0005) and the cumulative (total) median days on systemic antibiotic treatment was shortened by 8 days (15 vs 23 days, p = 0.0008). Piperacillin/tazobactam (p = 0.02), carbapenems (p = 0.05) and empiric broad-spectrum antifungals (p antibiotic use in this study. These benefits must be evaluated vs the risks of development of resistant bacterial strains, making fluoroquinolone prophylaxis an open question for debate.

  20. The multivariate egg: quantifying within- and among-clutch correlations between maternally derived yolk immunoglobulins and yolk androgens using multivariate mixed models.

    Science.gov (United States)

    Postma, Erik; Siitari, Heli; Schwabl, Hubert; Richner, Heinz; Tschirren, Barbara

    2014-03-01

    Egg components are important mediators of prenatal maternal effects in birds and other oviparous species. Because different egg components can have opposite effects on offspring phenotype, selection is expected to favour their mutual adjustment, resulting in a significant covariation between egg components within and/or among clutches. Here we tested for such correlations between maternally derived yolk immunoglobulins and yolk androgens in great tit (Parus major) eggs using a multivariate mixed-model approach. We found no association between yolk immunoglobulins and yolk androgens within clutches, indicating that within clutches the two egg components are deposited independently. Across clutches, however, there was a significant negative relationship between yolk immunoglobulins and yolk androgens, suggesting that selection has co-adjusted their deposition. Furthermore, an experimental manipulation of ectoparasite load affected patterns of covariance among egg components. Yolk immunoglobulins are known to play an important role in nestling immune defence shortly after hatching, whereas yolk androgens, although having growth-enhancing effects under many environmental conditions, can be immunosuppressive. We therefore speculate that variation in the risk of parasitism may play an important role in shaping optimal egg composition and may lead to the observed pattern of yolk immunoglobulin and yolk androgen deposition across clutches. More generally, our case study exemplifies how multivariate mixed-model methodology presents a flexible tool to not only quantify, but also test patterns of (co)variation across different organisational levels and environments, allowing for powerful hypothesis testing in ecophysiology.

  1. Timing of initial arrival at the breeding site predicts age at first reproduction in a long-lived migratory bird

    Science.gov (United States)

    Becker, Peter H.; Dittmann, Tobias; Ludwigs, Jan-Dieter; Limmer, Bente; Ludwig, Sonja C.; Bauch, Christina; Braasch, Alexander; Wendeln, Helmut

    2008-01-01

    In long-lived vertebrates, individuals generally visit potential breeding areas or populations during one or more seasons before reproducing for the first time. During these years of prospecting, they select a future breeding site, colony, or mate and improve various skills and their physical condition to meet the requirements of reproduction. One precondition of successful reproduction is arrival in time on the breeding grounds. Here, we study the intricate links among the date of initial spring arrival, body mass, sex, and the age of first breeding in the common tern Sterna hirundo, a long-lived migratory colonial seabird. The study is based on a unique, individual-based, long-term dataset of sexed birds, marked with transponders, which allow recording their individual arrival, overall attendance, and clutch initiation remotely and automatically year by year over the entire lifetime at the natal colony site. We show that the seasonal date of initial arrival at the breeding grounds predicts the individual age at first reproduction, which mostly occurs years later. Late first-time arrivals remain delayed birds throughout subsequent years. Our findings reveal that timing of arrival at the site of reproduction and timing of reproduction itself are coherent parameters of individual quality, which are linked with the prospects of the breeding career and may have consequences for fitness. PMID:18711134

  2. Simulacioni model višelamelastih frikcionih sklopova / Simulation model of multiple plate friction clutches and brakes

    Directory of Open Access Journals (Sweden)

    Aleksandar Grkić

    2009-01-01

    Full Text Available Višelamelasti frikcioni sklopovi koriste se za promenu stepena prenosa u planetarnim menjačkim prenosnicima motornih vozila. Razvijeni simulacioni model frikcione spojnice i kočnice omogućava simulaciju rada menjačkog prenosnika pri promeni stepena prenosa. Primenom razvijenog modela moguće je na bazi simulacije analizirati prelazni proces pri promeni stepena prenosa i obezbediti identifikaciju relevantnih parametara bez izrade većeg broja fizičkih prototipova. Na taj način obezbeđuje se smanjenje troškova i skraćenje procesa razvoja novih prenosnika snage, uz poboljšanje upotrebnog kvaliteta. Simulacioni model može da se koristi i pri razvoju upravljačkog sistema menjačkog prenosnika za definisanje potrebnih karakteristika njegovih komponenata. / Multiple plate friction clutches and brakes are used for gear shifting within planetary gear trains of motor vehicles. The developed simulation model of the friction clutch and brake enables the simulation and the analysis of the planetary gear train transitional processes during gear shifting and provides identification of relevant parameters without making numerous physical prototypes. Costs are thus reduced and time for developing new gear trains shortened, while the product quality is increased. The simulation model can be use additionally in developing steering systems of planetary gear trains for defining characteristics of their components.

  3. A Polynomial Estimate of Railway Line Delay

    DEFF Research Database (Denmark)

    Cerreto, Fabrizio; Harrod, Steven; Nielsen, Otto Anker

    2017-01-01

    Railway service may be measured by the aggregate delay over a time horizon or due to an event. Timetables for railway service may dampen aggregate delay by addition of additional process time, either supplement time or buffer time. The evaluation of these variables has previously been performed...... by numerical analysis with simulation. This paper proposes an analytical estimate of aggregate delay with a polynomial form. The function returns the aggregate delay of a railway line resulting from an initial, primary, delay. Analysis of the function demonstrates that there should be a balance between the two...

  4. Delayed puberty in girls

    Science.gov (United States)

    ... sexual development - girls; Pubertal delay - girls; Constitutional delayed puberty ... In most cases of delayed puberty, growth changes just begin later than usual, sometimes called a late bloomer. Once puberty begins, it progresses normally. This pattern runs ...

  5. Delayed Puberty (For Teens)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Delayed Puberty KidsHealth / For Teens / Delayed Puberty What's in this ... wonder if there's anything wrong. What Is Delayed Puberty? Puberty is the time when your body grows ...

  6. Diagnostic Delay in Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Mølbaek, Karen; Hørslev-Petersen, Kim; Primdahl, Jette

    2016-01-01

    BACKGROUND: To prevent joint damage among patients with rheumatoid arthritis (RA), there is a need to minimize delays from the onset of symptoms until the initiation of appropriate therapy. The present study explored the factors that have an impact on the time it takes for Danish patients with RA...

  7. Clutch and egg allometry of the turtle Mauremys leprosa (Chelonia: Geoemydidae) from a polluted peri-urban river in west-central Morocco

    Science.gov (United States)

    Naimi, Mohamed; Znari, Mohammed; Lovich, Jeffrey E.; Feddadi, Youssef; Baamrane, Moulay Abdeljalil Ait

    2012-01-01

    We examined the relationships of clutch size (CS) and egg size to female body size (straight-line carapace length, CL) in a population of the turtle Mauremys leprosa from a polluted segment of oued (river) Tensift in arid west-central Morocco. Twenty-eight adult females were collected in May–July, 2009 and all were gravid. Each was weighed, measured, humanely euthanized and then dissected. Oviductal shelled eggs were removed, weighed (egg mass, EM) and measured for length (EL) and width (EW). Clutch mass (CM) was the sum of EM for a clutch. Pelvic aperture width (PAW) was measured at the widest point between the ilia bones through which eggs must pass at oviposition. The smallest gravid female had a CL of 124.0 mm. Mean CS was relatively large (9.7±2.0 eggs, range: 3–13) and may reflect high productivity associated with polluted (eutrophic) waters. Regression analyses were conducted using log-transformed data. CM increased isometrically with maternal body size. CS, EW and EM were all significantly hypoallometric in their relationship with CL. EL did not change significantly with increases in CL. EW increased at a hypoallometric rate with increasing CL but was unconstrained by PAW since the widest egg was smaller than the narrowest PAW measurement when excluding the three smallest females. Smaller females may have EW constrained by PAW. As females increase in size they increase both clutch size and egg width in contradiction to predictions of optimal egg size theory.

  8. Within-Clutch Variation in Yolk Testosterone as an Adaptive Maternal Effect to Modulate Avian Sibling Competition : Evidence from a Comparative Study

    NARCIS (Netherlands)

    Muller, Martina; Groothuis, Ton G. G.; Bronstein, Judith L.; Demas, Greg

    In many species, embryos are exposed to maternal hormones in utero, in the egg, or in the seed. In birds, mothers deposit substantial testosterone into their eggs, which enhances competitive ability of offspring. These maternal testosterone concentrations vary systematically within clutches in

  9. Clutch size variation in Tawny Owls (Strix aluco) from adjacent valley systems: can this be used as a surrogate to investigate temporal and spatial variations in vole density?

    Science.gov (United States)

    Steve J. Petty; Billy L. Fawkes

    1997-01-01

    Research on Tawny Owls (Strix aluco) in Kielder Forest, northern England, since 1981 demonstrated that field voles (Microtus agrestis) were their most important food. Here, field voles exhibited a 3-4 year cycle of abundance, and mean clutch size in Tawny Owls was significantly related to vole abundance in March. In this analysis...

  10. Evaluation of asbestos exposure within the automotive repair industry: a study involving removal of asbestos-containing body sealants and drive clutch replacement.

    Science.gov (United States)

    Blake, Charles L; Dotson, G Scott; Harbison, Raymond D

    2008-12-01

    Two independent assessments were performed of airborne asbestos concentrations generated during automotive repair work on vintage vehicles . The first involved removal of asbestos-containing seam sealant, and the second involved servicing of a drive clutch. Despite the relatively high concentrations (5.6-28%) of chrysotile fibers detected within bulk samples of seam sealant, the average asbestos concentration for personal breathing zone (PBZ) samples during seam sealant removal was 0.006 f/cc (fibers/cubic centimeter of air). Many other air samples contained asbestos at or below the analytical limit of detection (LOD). Pneumatic chiseling of the sealant material during removal resulted in 69% of area air samples containing asbestos. Use of this impact tool liberated more asbestos than hand scraping. Asbestos fibers were only detected in air samples collected during the installation of a replacement clutch. The highest asbestos corrected airborne fiber concentration observed during clutch installation was 0.0028 f/cc. This value is approximately 100 times lower than Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) of 0.1f/cc. The airborne asbestos concentrations observed during the servicing of vintage vehicles with asbestos-containing seam sealant and clutches are comparable to levels reported for repair work involving brake components and gaskets.

  11. Research on Gear Shifting Process without Disengaging Clutch for a Parallel Hybrid Electric Vehicle Equipped with AMT

    Directory of Open Access Journals (Sweden)

    Hui-Long Yu

    2014-01-01

    Full Text Available Dynamic models of a single-shaft parallel hybrid electric vehicle (HEV equipped with automated mechanical transmission (AMT were described in different working stages during a gear shifting process without disengaging clutch. Parameters affecting the gear shifting time, components life, and gear shifting jerk in different transient states during a gear shifting process were deeply analyzed. The mathematical models considering the detailed synchronizer working process which can explain the gear shifting failure, long time gear shifting, and frequent synchronizer failure phenomenon in HEV were derived. Dynamic coordinated control strategy of the engine, motor, and actuators in different transient states considering the detailed working stages of synchronizer in a gear shifting process of a HEV is for the first time innovatively proposed according to the state of art references. Bench test and real road test results show that the proposed control strategy can improve the gear shifting quality in all its evaluation indexes significantly.

  12. Two-stage actuation system using DC motors and piezoelectric actuators for controllable industrial and automotive brakes and clutches

    Science.gov (United States)

    Neelakantan, Vijay A.; Washington, Gregory N.; Bucknor, Norman K.

    2005-05-01

    High bandwidth actuation systems that are capable of simultaneously producing relatively large forces and displacements are required for use in automobiles and other industrial applications. Conventional hydraulic actuation mechanisms used in automotive brakes and clutches are complex, inefficient and have poor control robustness. These lead to reduced fuel economy, controllability issues and other disadvantages. This paper involves the design, development, testing and control of a two-stage hybrid actuation mechanism by combining classical actuators like DC motors and advanced smart material actuators like piezoelectric actuators. The paper also discusses the development of a robust control methodology using the Internal Model Control (IMC) principle and emphasizes the robustness property of this control methodology by comparing and studying simulation and experimental results.

  13. Dynamic Coordinated Shifting Control of Automated Mechanical Transmissions without a Clutch in a Plug-In Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Xinlei Liu

    2012-08-01

    Full Text Available On the basis of the shifting process of automated mechanical transmissions (AMTs for traditional hybrid electric vehicles (HEVs, and by combining the features of electric machines with fast response speed, the dynamic model of the hybrid electric AMT vehicle powertrain is built up, the dynamic characteristics of each phase of shifting process are analyzed, and a control strategy in which torque and speed of the engine and electric machine are coordinatively controlled to achieve AMT shifting control for a plug-in hybrid electric vehicle (PHEV without clutch is proposed. In the shifting process, the engine and electric machine are well controlled, and the shift jerk and power interruption and restoration time are reduced. Simulation and real car test results show that the proposed control strategy can more efficiently improve the shift quality for PHEVs equipped with AMTs.

  14. Record length, mass, and clutch size in the nonindigenous Burmese Python, Python bivittatus Kuhl 1820 (Squamata: Pythonidae), in Florida

    Science.gov (United States)

    Krysko, Kenneth L.; Hart, Kristen M.; Smith, Brian J.; Selby, Thomas H.; Cherkiss, Michael S.; Coutu, Nicholas T.; Reichart, Rebecca M.; Nuñez, Leroy P.; Mazzotti, Frank J.; Snow, Ray W.

    2012-01-01

    The Burmese Python, Python bivittatus Kuhl 1820 (Squamata: Pythonidae), is indigenous to northern India,east to southern China, and south to Vietnam and a few islands in Indonesia (Barker and Barker 2008, Reed and Rodda 2009). This species has been introduced since at least 1979 in southern Florida, USA, where it likely began reproducing and became established during the 1980s (Meshaka et al. 2000, Snowet al. 2007b,Kraus 2009, Krysko et al. 2011, Willson et al. 2011). Python bivittatus has been documented in Florida consuming a variety of mammals and birds, and the American Alligator(Alligator mississippiensis) (Snowet al. 2007a, 2007b; Harvey et al. 2008; Rochford et al. 2010b; Holbrook and Chesnes 2011), many of which are protected species. Herein, we provide details on two of the largest known wild P. bivittatus in Florida to date, including current records on length,mass,clutch size, and diet.

  15. Speech and Language Delay

    Science.gov (United States)

    ... OTC Relief for Diarrhea Home Diseases and Conditions Speech and Language Delay Condition Speech and Language Delay Share Print Table of Contents1. ... Treatment6. Everyday Life7. Questions8. Resources What is a speech and language delay? A speech and language delay ...

  16. Experimental Investigation on The Electromagnetic Clutch Water pump and Pneumatic Compressor for Improving the Efficiency of an Engine

    Science.gov (United States)

    Kumarasubramanian, R.; Xavier, Goldwin; Nishanthi, W. Mary; Rajasekar, R.

    2017-05-01

    Considering the fuel crises today many work and research were conducted to reduce the fuel consumption of the internal combustion engine. The fuel consumption of an internal combustion engine can be relatively reduced by use of the electromagnetic clutch water pump and pneumatic compressor. Normally in an engine, the water pump is driven by the crankshaft, with an aid of belt, for the circulation of the water for the cooling process. The circulation of coolant is resisted by the thermostat valve, while the temperature inside the coolant jacket of the engine is below 375K the thermostat is closed only above 375K it tends to open. But water pump run continuously even when thermostat is closed. In pneumatic braking system, pneumatic or air compressor purpose is to compress the air and stored into the storage tank for the brake operation. When the air pressure of the storage tanks gets increases above its storage capacity pressure is regulated by governor, by passing them to atmosphere. Such unnecessary work of this water pump and air compressor can be minimized by use of the electromagnetic clutch water pump and air compressor. The European Driving Cycle is used to evaluate the performance of this water pump and air compressor when used in an engine. The result shows that the fuel economy of the engine while using electromagnetic water pump and pneumatic compressor were improved by 8.0% compared with conventional types which already exist. The application of these electromagnetic water pump and pneumatic compressor are expected to contribute for the improvement of engine performance because of their effect in reduction of the rate of fuel consumption.

  17. ATFM airborne delays without extra fuel consumption in wind conditions

    OpenAIRE

    Delgado, L.; Prats, X.

    2012-01-01

    Air Traffic Flow Management (ATFM) regulations, such as ground holdings, are often canceled before their initially planned ending time. The ground delays impact on the cost of recovering part of the delay if the regulation is canceled, as aircraft are still at the origin airport. In previous publications, the authors have suggested a speed reduction strategy to split the assigned ATFM delay between ground delay and airborne delay. By flying at the the minimum speed that g...

  18. Estimation of genetic variability and selection response for clutch length in dwarf brown-egg layers carrying or not the naked neck gene

    Directory of Open Access Journals (Sweden)

    Tixier-Boichard Michèle

    2003-03-01

    Full Text Available Abstract In order to investigate the possibility of using the dwarf gene for egg production, two dwarf brown-egg laying lines were selected for 16 generations on average clutch length; one line (L1 was normally feathered and the other (L2 was homozygous for the naked neck gene NA. A control line from the same base population, dwarf and segregating for the NA gene, was maintained during the selection experiment under random mating. The average clutch length was normalized using a Box-Cox transformation. Genetic variability and selection response were estimated either with the mixed model methodology, or with the classical methods for calculating genetic gain, as the deviation from the control line, and the realized heritability, as the ratio of the selection response on cumulative selection differentials. Heritability of average clutch length was estimated to be 0.42 ± 0.02, with a multiple trait animal model, whereas the estimates of the realized heritability were lower, being 0.28 and 0.22 in lines L1 and L2, respectively. REML estimates of heritability were found to decline with generations of selection, suggesting a departure from the infinitesimal model, either because a limited number of genes was involved, or their frequencies were changed. The yearly genetic gains in average clutch length, after normalization, were estimated to be 0.37 ± 0.02 and 0.33 ± 0.04 with the classical methods, 0.46 ± 0.02 and 0.43 ± 0.01 with animal model methodology, for lines L1 and L2 respectively, which represented about 30% of the genetic standard deviation on the transformed scale. Selection response appeared to be faster in line L2, homozygous for the NA gene, but the final cumulated selection response for clutch length was not different between the L1 and L2 lines at generation 16.

  19. Delayed child-bearing.

    Science.gov (United States)

    Johnson, Jo-Ann; Tough, Suzanne

    2012-01-01

    compensate for age-related decline in fertility. (II-2A) 2. A fertility evaluation should be initiated after 6 months of unprotected intercourse without conception in women 35 to 37 years of age, and earlier in women > 37 years of age. (II-2A) 3. Prospective parents should be informed that semen quality and male fertility deteriorate with advancing age and that the risk of genetic disorders in offspring increases. (II-2A) 4. Women ≥ 35 years of age should be offered screening for fetal aneuploidy and undergo a detailed second trimester ultrasound examination to look for significant fetal birth defects (particularly cardiac defects). (II-1A) 5. Delayed child-bearing is associated with increased obstetrical and perinatal complications. Care providers need to be aware of these complications and adjust obstetrical management protocols to ensure optimal maternal and perinatal outcomes. (II-2A) 6. All adults of reproductive age should be aware of the obstetrical and perinatal risks of advanced maternal age so they can make informed decisions about the timing of child-bearing. (II-2A) 7. Strategies to improve informed decision-making by prospective parents should be designed, implemented, and evaluated. These strategies should provide opportunity for adults to understand the potential medical, social, and economic consequences of child-bearing throughout the reproductive years. (III-B) 8. Barriers to healthy reproduction, including workplace policies, should be reviewed to optimize the likelihood of healthy pregnancies. (III-C).

  20. UAVs and Control Delays

    National Research Council Canada - National Science Library

    de Vries, S. C

    2005-01-01

    .... Delays of about 250-300 ms often lead to unacceptable airplane handling qualities. Techniques such as filtering and predictive displays may extend the range of acceptable delays up to about 400 ms...

  1. Delayed puberty in boys

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007695.htm Delayed puberty in boys To use the sharing features on this page, please enable JavaScript. Delayed puberty in boys is when puberty does not begin ...

  2. Delayed Orgasm and Anorgasmia

    OpenAIRE

    Jenkins, Lawrence C.; Mulhall, John P.

    2015-01-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies; which include: medications, penile sensation loss, endocrinopathies, penile hyperstimulation and psychological etiologies, amongst others. Unfortunately, ...

  3. Analysis and Design of a Permanent Magnet Bi-Stable Electro-Magnetic Clutch Unit for In-Wheel Electric Vehicle Drives

    Directory of Open Access Journals (Sweden)

    Wanli Cai

    2015-06-01

    Full Text Available Clutches have been used in internal combustion vehicles and concentrated electric vehicles (EVs to smoothen impulsion while starting and shifting. This paper proposes a permanent magnet bi-stable electromagnetic clutch unit (PMBECU which is specially introduced into in-wheel EVs to make the rigid connection between hub and wheel more flexible. Firstly, the operation principle of the PMBECU is illustrated. Then, the basic magnetic circuit model is presented and analyzed, followed by optimal design of the main structural parameters by investigating the PM leakage flux coefficient. Further, according to the basic electromagnetic characteristics of the PMBECU, the current pulse supply is put forward, and the minimum pulse width which enables the operation of the PMBECU and its dynamic characteristics are analyzed by an improved finite element method. Finally, a prototype machine is manufactured and tested to validate all the analysis results.

  4. Effects of sea ice on breeding numbers and clutch size of a high arctic population of the common eider Somateria mollissima

    Science.gov (United States)

    Mehlum, Fridtjof

    2012-04-01

    The breeding performance of high-arctic bird populations shows large inter-annual variation that may be attributed to environmental variability, such as the timing of snow melt and break-up of the landfast sea ice that surrounds breeding colonies on islands and along coasts. In the Kongsfjorden area (79°N) on Svalbard, the number of breeding pairs and the average egg clutch size vary considerably among years. In this study, data on breeding performance are presented from 15 years in the period 1981-2000. The results showed that early break-up of sea ice in Kongsfjorden resulted in larger numbers of nests and larger average clutch sizes than late break-up. Also, individual islands with early break-up of sea ice in a particular year had more nests and larger clutch sizes compared to other islands surrounded by sea ice during a longer period in spring. Thus, the inter-annual variation in the break-up of sea ice in the fjord has considerable implications for the inter-annual variability of recruitment to the population. The results indicate that the effects of global warming on changes in the sea ice melting regime in coastal regions are important for the reproductive output of island-nesting eiders.

  5. Genomic dissection of variation in clutch size and egg mass in a wild great tit (Parus major) population.

    Science.gov (United States)

    Santure, Anna W; De Cauwer, Isabelle; Robinson, Matthew R; Poissant, Jocelyn; Sheldon, Ben C; Slate, Jon

    2013-08-01

    Clutch size and egg mass are life history traits that have been extensively studied in wild bird populations, as life history theory predicts a negative trade-off between them, either at the phenotypic or at the genetic level. Here, we analyse the genomic architecture of these heritable traits in a wild great tit (Parus major) population, using three marker-based approaches - chromosome partitioning, quantitative trait locus (QTL) mapping and a genome-wide association study (GWAS). The variance explained by each great tit chromosome scales with predicted chromosome size, no location in the genome contains genome-wide significant QTL, and no individual SNPs are associated with a large proportion of phenotypic variation, all of which may suggest that variation in both traits is due to many loci of small effect, located across the genome. There is no evidence that any regions of the genome contribute significantly to both traits, which combined with a small, nonsignificant negative genetic covariance between the traits, suggests the absence of genetic constraints on the independent evolution of these traits. Our findings support the hypothesis that variation in life history traits in natural populations is likely to be determined by many loci of small effect spread throughout the genome, which are subject to continued input of variation by mutation and migration, although we cannot exclude the possibility of an additional input of major effect genes influencing either trait. © 2013 John Wiley & Sons Ltd.

  6. Model for adhesion clutch explains biphasic relationship between actin flow and traction at the cell leading edge

    Science.gov (United States)

    Craig, Erin M.; Stricker, Jonathan; Gardel, Margaret L.; Mogilner, Alex

    2015-01-01

    Cell motility relies on the continuous reorganization of a dynamic actin-myosin-adhesion network at the leading edge of the cell, in order to generate protrusion at the leading edge and traction between the cell and its external environment. We analyze experimentally measured spatial distributions of actin flow, traction force, myosin density, and adhesion density in control and pharmacologically perturbed epithelial cells in order to develop a mechanical model of the actin-adhesion-myosin self-organization at the leading edge. A model in which the F-actin network is treated as a viscous gel, and adhesion clutch engagement is strengthened by myosin but weakened by actin flow, can explain the measured molecular distributions and correctly predict the spatial distributions of the actin flow and traction stress. We test the model by comparing its predictions with measurements of the actin flow and traction stress in cells with fast and slow actin polymerization rates. The model predicts how the location of the lamellipodium-lamellum boundary depends on the actin viscosity and adhesion strength. The model further predicts that the location of the lamellipodium-lamellum boundary is not very sensitive to the level of myosin contraction. PMID:25969948

  7. Radionuclide scan findings in delayed splenic rupture

    International Nuclear Information System (INIS)

    Flickinger, F.W.; Jackson, G.L.

    1978-01-01

    An initial liver/spleen scan performed on a patient with blunt abdominal trauma was negative 3 days following the accident. A follow-up scan 7 days later showed definite evidence of splenic rupture, proved surgically. The authors conclude that, in such cases, spleen scans may be negative initially because of delayed splenic ruptures

  8. Development of delayed radiation necrosis

    International Nuclear Information System (INIS)

    Ohara, ShigFeki; Takagi, Terumasa; Shibata, Taichiro; Nagai, Hajime.

    1983-01-01

    The authors discussed the developing process of delayed radiation necrosis of the brain from the case of a 42-year-old female who developed intracranial hypertension and left hemiparesis 5 and a half years after radiotherapy for pituitary adenoma. The initial sign of radiation necrosis was from a CT scan taken 3 and a half years after radiotherapy showing an irregular low density lesion in the right temporal lobe. CT scan 2 years later demonstrated displacement of the midline structures to the left and a larger low density lesion with partially high density in the right MCA territory that was enhanced with intravenous contrast medium. Recovery after a right temporal lobectomy and administration of steroid hormone were uneventful. Eight months later there were no signs of raised intracranial pressure nor of neurological deficits. Tissues obtained from the right temporal lobe at lobectomy revealed the characteristic changes of delayed radiation necrosis; a mixture of fresh, recent, and old vascular lesions in the same specimen. From these findings, it was speculated that delayed radiation necrosis might initially occur within several years after radiotherapy and might gradually take a progressive and extended course, even in cases whose clinical symptoms develop much later. (author)

  9. Representing delayed force feedback as a combination of current and delayed states.

    Science.gov (United States)

    Avraham, Guy; Mawase, Firas; Karniel, Amir; Shmuelof, Lior; Donchin, Opher; Mussa-Ivaldi, Ferdinando A; Nisky, Ilana

    2017-10-01

    To adapt to deterministic force perturbations that depend on the current state of the hand, internal representations are formed to capture the relationships between forces experienced and motion. However, information from multiple modalities travels at different rates, resulting in intermodal delays that require compensation for these internal representations to develop. To understand how these delays are represented by the brain, we presented participants with delayed velocity-dependent force fields, i.e., forces that depend on hand velocity either 70 or 100 ms beforehand. We probed the internal representation of these delayed forces by examining the forces the participants applied to cope with the perturbations. The findings showed that for both delayed forces, the best model of internal representation consisted of a delayed velocity and current position and velocity. We show that participants relied initially on the current state, but with adaptation, the contribution of the delayed representation to adaptation increased. After adaptation, when the participants were asked to make movements with a higher velocity for which they had not previously experienced with the delayed force field, they applied forces that were consistent with current position and velocity as well as delayed velocity representations. This suggests that the sensorimotor system represents delayed force feedback using current and delayed state information and that it uses this representation when generalizing to faster movements. NEW & NOTEWORTHY The brain compensates for forces in the body and the environment to control movements, but it is unclear how it does so given the inherent delays in information transmission and processing. We examined how participants cope with delayed forces that depend on their arm velocity 70 or 100 ms beforehand. After adaptation, participants applied opposing forces that revealed a partially correct representation of the perturbation using the current and the

  10. Delayed orgasm and anorgasmia.

    Science.gov (United States)

    Jenkins, Lawrence C; Mulhall, John P

    2015-11-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies, which include medications, penile sensation loss, endocrinopathies, penile hyperstimulation, and psychological etiologies. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  11. Delayed encephalopathy after acute carbon monoxide poisoning

    Directory of Open Access Journals (Sweden)

    Mehmet İbrahim Turan

    2014-03-01

    Full Text Available Carbon monoxide poisoning is a major cause of death following attempted suicide and accidental exposures. Although clinical presentation depends on the duration and the intensity of exposure, the assessment of the severity of intoxication is difficult. A small percentage of patients who show complete initial recovery may develop delayed neurological deficits. Delayed encephalopathy after acute carbon monoxide poisoning is a rare and poor prognosis neurologic disorders and there is no specific treatment. We present a case with early onset of delayed encephalopathy after acute carbon monoxide poisoning with typical cranial imaging findings in a child with atypical history and clinical presentation.

  12. "Clutching a knifeblade": human rights and development from Asian women's perspective.

    Science.gov (United States)

    Sancho-liao, N

    1993-06-01

    A brief, vivid portrait of the human rights conditions for women in Asia was presented: "kapit sa patalim" or utter despair, urban migration, export processing zones, tourism and prostitution, political repression, and military sexual slavery. Advocates of women's human rights for Asian women must contend with patriarchal and male-dominated systems that oppress and exploit women to a much greater extent than men. Liberation from these systems and the domination and exploitation by wealthier nations must be a goal of a new economic world order. Unjust and repressive structures must be destroyed, and equitable distribution of wealth and democracy and popular initiatives promoted. The status of women must be raised to coequal status with men. The most important objective of human rights advocates should be the empowerment of women at the individual, community, national, regional, and international level. The Asian Women's Human Rights Council was established as an addition to 3 already operating regional commissions of women's organizations. The aim was not just to describe women as victims, but to pressure development activity to account for women's human rights. Sex tribunals have been scheduled between 1993 and 1994 to address the following issues: 1) sex trafficking (Japan, May 1993); 2) violence against women (Pakistan, December 1993); 3) militarism, environment, and violence against women (Korea, March 1994); 4) crimes of development against women in Asia (India); 5) religion and violence against women (Malaysia, 1994); and 6) indigenous women (December 1994). Women were victims when Filipino domestic workers were stranded and raped in Iraq during the chaos of war, when girls from landless peasant families migrated near Clark Air Force Base to earn a living as prostitutes for US servicemen, when women were forced to work 36-hour shifts in foreign-owned garment factories in Bataan, when women migrated for work, and when women were abused and battered in

  13. American Dream Delayed

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia; Miller, Robert A.

    This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female hou...

  14. Delayed Partial Nephrectomy for Hydronephrosis After Renal Trauma.

    Science.gov (United States)

    Setia, Shaan; Jackson, Jessica Nicole; Herndon, C D Anthony; Corbett, Sean T

    2017-03-01

    Delayed sequelae following conservative management of renal trauma in the pediatric population are uncommon. Reports of delayed operations to manage these sequelae are even less common. Here we present the case of a 16-year-old male patient who had delayed development of upper urinary tract obstruction with recurrent infections following high-grade renal trauma managed conservatively. Ultimately, he required a robotic-assisted partial nephrectomy 2 years after initial nonoperative management. This is unique as no prior studies to our knowledge have described delayed hydronephrosis and delayed partial nephrectomy over a year following renal trauma. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Interspecific variation in the relationship between clutch size, laying date and intensity of urbanization in four species of hole-nesting birds.

    Science.gov (United States)

    Vaugoyeau, Marie; Adriaensen, Frank; Artemyev, Alexandr; Bańbura, Jerzy; Barba, Emilio; Biard, Clotilde; Blondel, Jacques; Bouslama, Zihad; Bouvier, Jean-Charles; Camprodon, Jordi; Cecere, Francesco; Charmantier, Anne; Charter, Motti; Cichoń, Mariusz; Cusimano, Camillo; Czeszczewik, Dorota; Demeyrier, Virginie; Doligez, Blandine; Doutrelant, Claire; Dubiec, Anna; Eens, Marcel; Eeva, Tapio; Faivre, Bruno; Ferns, Peter N; Forsman, Jukka T; García-Del-Rey, Eduardo; Goldshtein, Aya; Goodenough, Anne E; Gosler, Andrew G; Grégoire, Arnaud; Gustafsson, Lars; Harnist, Iga; Hartley, Ian R; Heeb, Philipp; Hinsley, Shelley A; Isenmann, Paul; Jacob, Staffan; Juškaitis, Rimvydas; Korpimäki, Erkki; Krams, Indrikis; Laaksonen, Toni; Lambrechts, Marcel M; Leclercq, Bernard; Lehikoinen, Esa; Loukola, Olli; Lundberg, Arne; Mainwaring, Mark C; Mänd, Raivo; Massa, Bruno; Mazgajski, Tomasz D; Merino, Santiago; Mitrus, Cezary; Mönkkönen, Mikko; Morin, Xavier; Nager, Ruedi G; Nilsson, Jan-Åke; Nilsson, Sven G; Norte, Ana C; Orell, Markku; Perret, Philippe; Perrins, Christopher M; Pimentel, Carla S; Pinxten, Rianne; Richner, Heinz; Robles, Hugo; Rytkönen, Seppo; Senar, Juan Carlos; Seppänen, Janne T; Pascoal da Silva, Luis; Slagsvold, Tore; Solonen, Tapio; Sorace, Alberto; Stenning, Martyn J; Tryjanowski, Piotr; von Numers, Mikael; Walankiewicz, Wieslaw; Møller, Anders Pape

    2016-08-01

    The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban compared to nearby natural areas. In some birds, breeding success is determined by synchrony between timing of breeding and peak food abundance. Pertinently, caterpillars are an important food source for the nestlings of many bird species, and their abundance is influenced by environmental factors such as temperature and date of bud burst. Higher temperatures and advanced date of bud burst in urban areas could advance peak caterpillar abundance and thus affect breeding phenology of birds. In order to test whether laying date advance and clutch sizes decrease with the intensity of urbanization, we analyzed the timing of breeding and clutch size in relation to intensity of urbanization as a measure of human impact in 199 nest box plots across Europe, North Africa, and the Middle East (i.e., the Western Palearctic) for four species of hole-nesters: blue tits (Cyanistes caeruleus), great tits (Parus major), collared flycatchers (Ficedula albicollis), and pied flycatchers (Ficedula hypoleuca). Meanwhile, we estimated the intensity of urbanization as the density of buildings surrounding study plots measured on orthophotographs. For the four study species, the intensity of urbanization was not correlated with laying date. Clutch size in blue and great tits does not seem affected by the intensity of urbanization, while in collared and pied flycatchers it decreased with increasing intensity of urbanization. This is the first large-scale study showing a species-specific major correlation between intensity of urbanization and the ecology of breeding. The underlying mechanisms for the relationships between life history and

  16. Dynamics and stability of rigid rotors levitated by passive cylinder-magnet bearings and driven/supported axially by pointwise contact clutch

    DEFF Research Database (Denmark)

    Andersen, Søren Bøgh; Enemark, Søren; Santos, Ilmar

    2013-01-01

    A stable rotor—supported laterally by passive magnetic bearings and longitudinally by magnetic forces and a clutch—loses suddenly its contact to the clutch and executes abruptly longitudinal movements away from its original equilibrium position as a result of small increases in angular velocity...... by MCMB using several configurations of magnet distribution are described based on an accurate nonlinear model able to reliably reproduce the rotor-bearing dynamic behaviour. Such investigations lead to: (a) clear physical explanation about the reasons for the rotor's unstable behaviour, losing its...

  17. Compensating for telecommunication delays during robotic telerehabilitation.

    Science.gov (United States)

    Consoni, Leonardo J; Siqueira, Adriano A G; Krebs, Hermano I

    2017-07-01

    Rehabilitation robotic systems may afford better care and telerehabilitation may extend the use and benefits of robotic therapy to the home. Data transmissions over distance are bound by intrinsic communication delays which can be significant enough to deem the activity unfeasible. Here we describe an approach that combines unilateral robotic telerehabilitation and serious games. This approach has a modular and distributed design that permits different types of robots to interact without substantial code changes. We demonstrate the approach through an online multiplayer game. Two users can remotely interact with each other with no force exchanges, while a smoothing and prediction algorithm compensates motions for the delay in the Internet connection. We demonstrate that this approach can successfully compensate for data transmission delays, even when testing between the United States and Brazil. This paper presents the initial experimental results, which highlight the performance degradation with increasing delays as well as improvements provided by the proposed algorithm, and discusses planned future developments.

  18. Diagnosis delay in tuberculosis and its consequences

    International Nuclear Information System (INIS)

    Habibullah, S.; Sheikh, M.A.; Sadiq, A.; Anwar, T.

    2004-01-01

    Objective: To find out the average duration from onset of symptoms to the diagnosis and treatment of tuberculosis, reasons for diagnostic delay, its consequences, association of variables and formulation of recommendations. Results: In this study it was found that average time from onset of initial symptoms to diagnosis and treatment of tuberculosis was 120 days. In 64% of the patients medical practitioners were responsible for delaying the diagnosis of tuberculosis. Loss of weight in 40% and haemoptysis is 21% were the consequences of diagnostic delay of tuberculosis. Delay in the diagnosis of tuberculosis was statistically significant in those patients who consulted private practitioners, and consequences of tuberculosis were severe in those patients who consulted late. (author)

  19. Neutron delayed choice experiments

    International Nuclear Information System (INIS)

    Bernstein, H.J.

    1986-01-01

    Delayed choice experiments for neutrons can help extend the interpretation of quantum mechanical phenomena. They may also rule out alternative explanations which static interference experiments allow. A simple example of a feasible neutron test is presented and discussed. (orig.)

  20. Quad nanosecond delay module

    International Nuclear Information System (INIS)

    McDonald, R.J.; Hunter, J.B.; Wozniak, G.J.

    1986-04-01

    Four nanosecond (ns) delay units have been designed to fit in a single-width NIM module. This module is particularly suited for use in conjunction with quad constant fraction timing discriminators (CFTDs) since it has four delay units that can be placed adjacent to the four units of the CFTD. A series of different length cables connected via DIP toggle switches provide delays of 0.60 ns in 4 ns increments. Thus, the CFTD delay can be optimized for pulses of different rise times from approx.10-100 ns. Design work for the PC board and silkscreening of the front panel were done with the MacDraw program on the Apple Mackintosh computer and printed with the Lasewriter printer. 6 refs

  1. Delayed rule following

    OpenAIRE

    Schmitt, David R.

    2001-01-01

    Although the elements of a fully stated rule (discriminative stimulus [SD], some behavior, and a consequence) can occur nearly contemporaneously with the statement of the rule, there is often a delay between the rule statement and the SD. The effects of this delay on rule following have not been studied in behavior analysis, but they have been investigated in rule-like settings in the areas of prospective memory (remembering to do something in the future) and goal pursuit. Discriminative even...

  2. Vernier Delay Unit

    International Nuclear Information System (INIS)

    Pierce, W.B.

    1984-10-01

    This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns

  3. Quad precision delay generator

    International Nuclear Information System (INIS)

    Krishnan, Shanti; Gopalakrishnan, K.R.; Marballi, K.R.

    1997-01-01

    A Quad Precision Delay Generator delays a digital edge by a programmed amount of time, varying from nanoseconds to microseconds. The output of this generator has an amplitude of the order of tens of volts and rise time of the order of nanoseconds. This was specifically designed and developed to meet the stringent requirements of the plasma focus experiments. Plasma focus is a laboratory device for producing and studying nuclear fusion reactions in hot deuterium plasma. 3 figs

  4. Modelling delays in pharmacokinetics

    International Nuclear Information System (INIS)

    Farooqi, Z.H.; Lambrecht, R.M.

    1990-01-01

    Linear system analysis has come to form the backbone of pharmacokinetics. Natural systems usually involve time delays, thus models incorporating them would be an order closer approximation to the real world compared to those that do not. Delays may be modelled in several ways. The approach considered in this study is to have a discrete-time delay dependent rate with the delay respresenting the duration between the entry of a drug into a compartment and its release in some form (may be as a metabolite) from the compartment. Such a delay may be because of one or more of several physiological reasons, like, formation of a reservoir, slow metabolism, or receptor binding. The mathematical structure this gives rise to is a system of delay-differential equations. Examples are given of simple one and two compartment systems with drugs like bumetanide, carbamazepine, and quinolone-caffeine interaction. In these examples generally a good fit is obtained and the suggested models form a good approximation. 21 refs., 6 figs

  5. [Delayed rupture of the spleen in a multiply injured patient].

    Science.gov (United States)

    Lică, I; Venter, M D; Mehic, R; Marian, R; Ionescu, G

    1997-01-01

    The authors present a case of delayed rupture of the spleen in a polytraumatised patient. This entity was defined as a late occurrence of signs and symptoms attributed to splenic injury not detected by diagnostic computed tomographic scanning during the initial examination. The mechanisms in which the delayed rupture of the spleen occurs are discussed and the conclusion is that the delayed rupture of the spleen represent a real clinical entity.

  6. The reasons for delay lumbar puncture

    Directory of Open Access Journals (Sweden)

    MH. Lotfi

    2017-04-01

    Full Text Available Early diagnosis of meningitis and encephalitis and prompt initiation of appropriate therapy is vital and any delay will lead to high mortality and serious and permanent morbidity. The main purpose of this study was to evaluate the management of 220 patients with suspected central nervous system (CNS infections (meningitis and encephalitis to determine the percentage of patients’ suspected CNS infection undergo lumbar puncture in acceptable time (in accordance with conventional algorithms. In this descriptive study, patients with suspected CNS infections admitted to Bu-Ali and Qods hospitals, in the period July 2013 to December 2015 were studied. Information of 220 patients was collected. Continuous variables were summarized as means ± standard deviation and categorical variables as frequencies and percentages. Lumbar puncture (LP in patients was delayed in 200 cases (91%. Most common causes of delay in performing LP were prolongation of the process of determining patient needs to puncture, satisfying patients, CT scan delay and the delay in allowing LP by neurologist. In this study, delaying LP rate was higher than other studies. It seems certain pattern in assistants’ visits for counseling. CT requests and neurologic consultation before LP performed for all adult patients.

  7. Nuclear size and cell division delay

    International Nuclear Information System (INIS)

    Bird, R.P.

    1986-01-01

    Radiation-induced division delay has been linked to damage at the nuclear envelope. Further, cells in G 2 phase are drastically arrested by high LET radiation such that single particles traversing cell nuclei may produce measurable division delay. A modest effort was initiated using two related cell lines of different size, near-diploid cells and near-tetraploid cells of Chinese hamster origin, to compare their sensitivity for radiation-induced division delay. If the nuclear surface is the critical target, then a larger nuclear cross-section presented to an alpha-particle beam should exhibit delay induced by a lesser particle fluence. Preliminary estimates of the extent of delay in asynchronous cultures following low doses of gamma-irradiation or of alpha-irradiation were made by in-situ observation of the time of onset of mitosis and by fixation and staining of cultures to determine the mitotic index as a function of time after irradiation. The basic approach to evaluating division delay will be to use Colecemid to accumulate mitotic cells over a period of time

  8. Optimal Joint Expected Delay Forwarding in Delay Tolerant Networks

    OpenAIRE

    Jia Xu; Xin Feng; Wen Jun Yang; Ru Chuan Wang; Bing Qing Han

    2013-01-01

    Multicopy forwarding schemes have been employed in delay tolerant network (DTN) to improve the delivery delay and delivery rate. Much effort has been focused on reducing the routing cost while retaining high performance. This paper aims to provide an optimal joint expected delay forwarding (OJEDF) protocol which minimizes the expected delay while satisfying a certain constant on the number of forwardings per message. We propose a comprehensive forwarding metric called joint expected delay (JE...

  9. Observations on early and delayed colostomy closure.

    Science.gov (United States)

    Tade, A O; Salami, B A; Ayoade, B A

    2011-06-01

    Traditional treatment of a variety of colorectal pathologies had included a diverting colostomy that was closed eight or more weeks later during a readmission. The aim of this retrospective study was to determine the outcomes of early colostomy closure and delayed colostomy closure in patients with temporary colostomies following traumatic and non-traumatic colorectal pathologies. In this study early colostomy closure was the closure of a colostomy within three weeks of its construction, while delayed colostomy closure referred to closure after 3 weeks. Complete records of the 37 adult patients who had temporary colostomy constructed and closed between Jan. 1997 December 2003 for various colorectal pathologies were studied. Fourteen patients had early colostomy closure while 23 had delayed closure. In the early colostomy closure group there were 10 men and 4 women. The mean age of the patients was 28yr with a range of 18-65yr. Colostomies were closed 9-18 days after initial colostomy construction. There was no mortality. Morbidity rate 28.6% (4 out of 14). There were two faecal fistulas (14.3%). Twenty-three patients had delayed colostomy closure 8 weeks to 18 months after initial colostomy construction. These were patients unfit for early surgery after initial colostomy construction because of carcinoma, significant weight loss, or sepsis. There was no mortality. Morbidity rate was 26.1%. There were 3 faecal fistulas (13.2%). Outcomes following early colostomy closure and delayed closure were comparable. Patients fit for surgery should have early closure whilst patients who may have compromised health should have delayed closure.

  10. Diagnosis delay in Libyan female breast cancer

    Directory of Open Access Journals (Sweden)

    Ermiah Eramah

    2012-08-01

    Full Text Available Abstract Aims To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. Methods 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008–2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay. Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire during an interview with each patient and from medical records. Results The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3–6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s that did not include a lump (p  Diagnosis delay was associated with bigger tumour size (p Conclusions Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast cancer. Especially, guidelines for good practices in managing

  11. Delayed splenic rupture presenting 70 days following blunt abdominal trauma.

    Science.gov (United States)

    Resteghini, Nancy; Nielsen, Jonpaul; Hoimes, Matthew L; Karam, Adib R

    2014-01-01

    Delayed splenic rupture following conservative management of splenic injury is an extremely rare complication. We report a case of an adult patient who presented with delayed splenic rupture necessitating splenectomy, 2 months following blunt abdominal trauma. Imaging at the initial presentation demonstrated only minimal splenic contusion and the patient was discharge following 24 hours of observation. © 2014.

  12. Assessing delay discounting in mice

    OpenAIRE

    Mitchell, Suzanne H.

    2014-01-01

    Delay discounting (also intertemporal choice or impulsive choice) is the process by which delayed outcomes, such as delayed food delivery, are valued less than the same outcomes delivered immediately or with a shorter delay. This process is of interest because many psychopathologies, including substance dependence, pathological gambling, attention deficit hyperactivity disorder and conduct disorder, are characterized by heightened levels of delay discounting. Some of these disorders are herit...

  13. Goodwin accelerator model revisited with fixed time delays

    Science.gov (United States)

    Matsumoto, Akio; Merlone, Ugo; Szidarovszky, Ferenc

    2018-05-01

    Dynamics of Goodwin's accelerator business cycle model is reconsidered. The model is characterized by a nonlinear accelerator and an investment time delay. The role of the nonlinearity for the birth of persistent oscillations is fully discussed in the existing literature. On the other hand, not much of the role of the delay has yet been revealed. The purpose of this paper is to show that the delay really matters. In the original framework of Goodwin [6], it is first demonstrated that there is a threshold value of the delay: limit cycles arise for smaller values than the threshold and so do sawtooth oscillations for larger values. In the extended framework in which a consumption or saving delay, in addition to the investment delay, is introduced, three main results are demonstrated under assumption of the identical length of investment and consumption delays. The dynamics with consumption delay is basically the same as that of the single delay model. Second, in the case of saving delay, the steady state can coexist with the stable and unstable limit cycles in the stable case. Third, in the unstable case, there is an interval of delay in which the limit cycle or the sawtooth oscillation emerges depending on the choice of the constant initial function.

  14. Estimating Delays In ASIC's

    Science.gov (United States)

    Burke, Gary; Nesheiwat, Jeffrey; Su, Ling

    1994-01-01

    Verification is important aspect of process of designing application-specific integrated circuit (ASIC). Design must not only be functionally accurate, but must also maintain correct timing. IFA, Intelligent Front Annotation program, assists in verifying timing of ASIC early in design process. This program speeds design-and-verification cycle by estimating delays before layouts completed. Written in C language.

  15. Permissible Delay in Payments

    Directory of Open Access Journals (Sweden)

    Yung-Fu Huang

    2007-01-01

    Full Text Available The main purpose of this paper wants to investigate the optimal retailer's lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must make a partial payment to the supplier when the order is received. Then the retailer must pay off the remaining balance at the end of the permissible delay period. In addition, we want to add the assumption that the retailer's storage space is limited. That is, the retailer will rent the warehouse to store these exceeding items when the order quantity is larger than retailer's storage space. Under these conditions, we model the retailer's inventory system as a cost minimization problem to determine the retailer's optimal cycle time and optimal order quantity. Three theorems are developed to efficiently determine the optimal replenishment policy for the retailer. Finally, numerical examples are given to illustrate these theorems and obtained a lot of managerial insights.

  16. Delayed neutrons in ANSTO

    International Nuclear Information System (INIS)

    Wall, T.

    1988-01-01

    Delayed neutron analysis carried out at the Australian Nuclear Scientific and Technology Organization facilities, provides a fast, high sensitivity, low cost, reliable method, particularly suitable for large batches of samples, and for non destructive analysis of a range of materials. While its main use has been in uranium exploration, other applications include archeological investigations, agriculture, oceanography and biology

  17. Delayed cerebral thrombosis complicating pneumococcal meningitis: an autopsy study

    NARCIS (Netherlands)

    Engelen-Lee, Joo-Yeon; Brouwer, Matthijs C.; Aronica, Eleonora; van de Beek, Diederik

    2018-01-01

    Background: Delayed cerebral thrombosis (DCT) is a devastating cerebrovascular complication in patients with excellent initial recovery of pneumococcal meningitis. The aetiology is unknown, but direct bacterial invasion, activation of coagulation or post-infectious immunoglobulin deposition has been

  18. Patient Delay, Diagnosis Delay and Treatment Delay for Breast Cancer: Comparison of the Pattern between Patients in Public and Private Health Sectors

    Directory of Open Access Journals (Sweden)

    Iraj Harirchi

    2015-05-01

    Full Text Available Background: The purpose of this study was to compare patient delay, diagnosis delay and treatment delay in breast cancer patients of selected public and private health centers in Tehran, Iran.Methods: In this cross-sectional study, female patients with newly diagnosed breast cancer in a public medical complex and a private breast clinic within one year were included. Patient delay was considered positive, if the interval between the detection of the first symptom by the patient and the first visit to a health care provider took longer than one month. Delay in diagnosis was defined as the period of more than one week between the first medical visit for the symptoms and the diagnosis of breast cancer. Following the confirmed diagnosis of breast malignancy, if the medical treatment was initiated later than one week, treatment delay had occurred. The potential reasons for patient, diagnosis and treatment delay according to the patients’ reports were also recorded.Results: Overall, 385 patients were included of whom 52.7% were recruited from the public hospitals and 47.3% from a private clinic. The prevalence of patient delay, diagnosis delay and treatment delay were 31.7%, 17.9% and 28.3%, respectively. Patient delay was significantly more common among patients with lower socio-economic status and those recruited from the public hospitals. All the patients with diagnosis delay were in the group recruited from the public hospitals.Conclusions: Gaps between women of different socio-economic levels of the society need to be addressed in order to decrease patient, diagnosis and treatment delay.

  19. Delay time and tunneling transient phenomena

    International Nuclear Information System (INIS)

    Garcia-Calderon, Gaston; Villavicencio, Jorge

    2002-01-01

    Analytic solutions to the time-dependent Schroedinger equation for cutoff wave initial conditions are used to investigate the time evolution of the transmitted probability density for tunneling. For a broad range of values of the potential barrier opacity α, we find that the probability density exhibits two evolving structures. One refers to the propagation of a forerunner related to a time domain resonance [Phys. Rev. A 64, 0121907 (2001)], while the other consists of a semiclassical propagating wave front. We find a regime where the forerunners are absent, corresponding to positive time delays, and show that this regime is characterized by opacities α c . The critical opacity α c is derived from the analytical expression for the delay time, which reflects a link between transient effects in tunneling and the delay time

  20. Experimentally reducing clutch size reveals a fixed upper limit to egg size in snakes, evidence from the king ratsnake, Elaphe carinata.

    Science.gov (United States)

    Ji, Xiang; Du, Wei-Guo; Li, Hong; Lin, Long-Hui

    2006-08-01

    Snakes are free of the pelvic girdle's constraint on maximum offspring size, and therefore present an opportunity to investigate the upper limit to offspring size without the limit imposed by the pelvic girdle dimension. We used the king ratsnake (Elaphe carinata) as a model animal to examine whether follicle ablation may result in enlargement of egg size in snakes and, if so, whether there is a fixed upper limit to egg size. Females with small sized yolking follicles were assigned to three manipulated, one sham-manipulated and one control treatments in mid-May, and two, four or six yolking follicles in the manipulated females were then ablated. Females undergoing follicle ablation produced fewer, but larger as well as more elongated, eggs than control females primarily by increasing egg length. This finding suggests that follicle ablation may result in enlargement of egg size in E. carinata. Mean values for egg width remained almost unchanged across the five treatments, suggesting that egg width is more likely to be shaped by the morphological feature of the oviduct. Clutch mass dropped dramatically in four- and six-follicle ablated females. The function describing the relationship between size and number of eggs reveals that egg size increases with decreasing clutch size at an ever-decreasing rate, with the tangent slope of the function for the six-follicle ablation treatment being -0.04. According to the function describing instantaneous variation in tangent slope, the maximum value of tangent slope should converge towards zero. This result provides evidence that there is a fixed upper limit to egg size in E. carinata.

  1. Best matching Barenblatt profiles are delayed

    International Nuclear Information System (INIS)

    Dolbeault, Jean; Toscani, Giuseppe

    2015-01-01

    The growth of the second moments of the solutions of fast diffusion equations is asymptotically governed by the behavior of self-similar solutions. However, at next order, there is a correction term which amounts to a delay depending on the nonlinearity and on a distance of the initial data to the set of self-similar Barenblatt solutions. This distance can be measured in terms of a relative entropy to the best matching Barenblatt profile. This best matching Barenblatt function determines a scale. In new variables based on this scale, which are given by a self-similar change of variables if and only if the initial datum is one of the Barenblatt profiles, the typical scale is monotone and has a limit. Coming back to original variables, the best matching Barenblatt profile is delayed compared to the self-similar solution with same initial second moment as the initial datum. Such a delay is a new phenomenon, which has to be taken into account for instance when fitting experimental data. (paper)

  2. Topological Acoustic Delay Line

    Science.gov (United States)

    Zhang, Zhiwang; Tian, Ye; Cheng, Ying; Wei, Qi; Liu, Xiaojun; Christensen, Johan

    2018-03-01

    Topological protected wave engineering in artificially structured media is at the frontier of ongoing metamaterials research that is inspired by quantum mechanics. Acoustic analogues of electronic topological insulators have recently led to a wealth of new opportunities in manipulating sound propagation with strikingly unconventional acoustic edge modes immune to backscattering. Earlier fabrications of topological insulators are characterized by an unreconfigurable geometry and a very narrow frequency response, which severely hinders the exploration and design of useful devices. Here we establish topologically protected sound in reconfigurable phononic crystals that can be switched on and off simply by rotating its three-legged "atoms" without altering the lattice structure. In particular, we engineer robust phase delay defects that take advantage of the ultrabroadband reflection-free sound propagation. Such topological delay lines serve as a paradigm in compact acoustic devices, interconnects, and electroacoustic integrated circuits.

  3. Delayed traumatic intracranial hematoma

    International Nuclear Information System (INIS)

    Tomita, Hiroki

    1984-01-01

    CT was performed serially within 24 hours after head injury in 64 patients having Glasgow Coma Scale of 14 or less or cranial fracture shown on roentgenogram. Delayed traumatic extradural hematoma was observed within 7-12 hours after head injury in 6 cases (9.4%). This was prominent in the frontal and occipital regions (67%). Good recovery was seen in 83.3%. Delayed traumatic intracerebral hematoma was observed within 6-24 hours after head injury in 17 cases (26.6%). This higher incidence was related to contre coup injury. Conservative treatment was possible in 14 of the 17 patients (82.4%), showing good recovery in 70%. (Namekawa, K.)

  4. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  5. REASONS FOR PATIENT DELAYS & HEALTH SYSTEM DELAYS FOR TUBERCULOSIS IN SOUTH INDIA

    Directory of Open Access Journals (Sweden)

    Kapil Goel

    2011-12-01

    Full Text Available Background: Globally, the burden of Tuberculosis is escalating. Early diagnosis and prompt initiation of tuberculosis treatment is essential for an effective tuberculosis control programme. Objectives: To study the self reported reasons for patient and health system (diagnosis & treatment delays in Tuberculosis patients. Methods: A community based cross sectional study was conducted among 98 new sputum positive TB cases aged > 15 years registered under RNTCP from Oct 2006 to June 2007 & receiving treatment under DOTS in Udupi taluk by interviewing them. Results: Total 98 patients were recruited and 68% were males. Out of 17 patients with patient delays, 82% felt that their symptoms were not severe, 71% felt that patient delay was due to lack of awareness and 71% did not take it seriously. Out of 86 patients with health system delays, 82.6% of patients mentioned that doctor has not advised for sputum examination, 76.7% of patients told that they first consulted a private doctor, 21% of them mentioned that doctor was unaware to diagnose TB. Conclusion: Symptoms not severe is the main reason for the patient delay and doctor didn’t advise for sputum examination is the main reason for health system delays.

  6. Delayed HIV diagnosis and initiation of antiretroviral therapy

    DEFF Research Database (Denmark)

    Lodi, Sara; Dray-Spira, Rosemary; Touloumi, Giota

    2014-01-01

    nine HIV cohorts within COHERE in Austria, France, Greece, Italy, Spain and Switzerland, collecting data on level of education in categories of the UNESCO/International Standard Classification of Education standard classification: non-completed basic, basic, secondary and tertiary education. We...

  7. Delaying information search

    Directory of Open Access Journals (Sweden)

    Yaniv Shani

    2012-11-01

    Full Text Available In three studies, we examined factors that may temporarily attenuate information search. People are generally curious and dislike uncertainty, which typically encourages them to look for relevant information. Despite these strong forces that promote information search, people sometimes deliberately delay obtaining valuable information. We find they may do so when they are concerned that the information might interfere with future pleasurable activities. Interestingly, the decision to search or to postpone searching for information is influenced not only by the value and importance of the information itself but also by well-being maintenance goals related to possible detrimental effects that negative knowledge may have on unrelated future plans.

  8. Vehicle barrier with access delay

    Science.gov (United States)

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  9. Genetic algorithm based on optimization of neural network structure for fault diagnosis of the clutch retainer mechanism of MF 285 tractor

    Directory of Open Access Journals (Sweden)

    S. F Mousavi

    2016-09-01

    Full Text Available Introduction The diagnosis of agricultural machinery faults must be performed at an opportune time, in order to fulfill the agricultural operations in a timely manner and to optimize the accuracy and the integrity of a system, proper monitoring and fault diagnosis of the rotating parts is required. With development of fault diagnosis methods of rotating equipment, especially bearing failure, the security, performance and availability of machines has been increasing. In general, fault detection is conducted through a specific procedure which starts with data acquisition and continues with features extraction, and subsequently failure of the machine would be detected. Several practical methods have been introduced for fault detection in rotating parts of machineries. The review of the literature shows that both Artificial Neural Networks (ANN and Support Vector Machines (SVM have been used for this purpose. However, the results show that SVM is more effective than Artificial Neural Networks in fault detection of such machineries. In some smart detection systems, incorporating an optimized method such as Genetic Algorithm in the Neural Network model, could improve the fault detection procedure. Consequently, the fault detection performance of neural networks may also be improved by combining with the Genetic Algorithm and hence will be comparable with the performance of the Support Vector Machine. In this study, the so called Genetic Algorithm (GA method was used to optimize the structure of the Artificial Neural Networks (ANN for fault detection of the clutch retainer mechanism of Massey Ferguson 285 tractor. Materials and Methods The test rig consists of some electro mechanical parts including the clutch retainer mechanism of Massey Ferguson 285 tractor, a supporting shaft, a single-phase electric motor, a loading mechanism to model the load of the tractor clutch and the corresponding power train gears. The data acquisition section consists of a

  10. The Strong Lensing Time Delay Challenge (2014)

    Science.gov (United States)

    Liao, Kai; Dobler, G.; Fassnacht, C. D.; Treu, T.; Marshall, P. J.; Rumbaugh, N.; Linder, E.; Hojjati, A.

    2014-01-01

    Time delays between multiple images in strong lensing systems are a powerful probe of cosmology. At the moment the application of this technique is limited by the number of lensed quasars with measured time delays. However, the number of such systems is expected to increase dramatically in the next few years. Hundred such systems are expected within this decade, while the Large Synoptic Survey Telescope (LSST) is expected to deliver of order 1000 time delays in the 2020 decade. In order to exploit this bounty of lenses we needed to make sure the time delay determination algorithms have sufficiently high precision and accuracy. As a first step to test current algorithms and identify potential areas for improvement we have started a "Time Delay Challenge" (TDC). An "evil" team has created realistic simulated light curves, to be analyzed blindly by "good" teams. The challenge is open to all interested parties. The initial challenge consists of two steps (TDC0 and TDC1). TDC0 consists of a small number of datasets to be used as a training template. The non-mandatory deadline is December 1 2013. The "good" teams that complete TDC0 will be given access to TDC1. TDC1 consists of thousands of lightcurves, a number sufficient to test precision and accuracy at the subpercent level, necessary for time-delay cosmography. The deadline for responding to TDC1 is July 1 2014. Submissions will be analyzed and compared in terms of predefined metrics to establish the goodness-of-fit, efficiency, precision and accuracy of current algorithms. This poster describes the challenge in detail and gives instructions for participation.

  11. Delayed rule following.

    Science.gov (United States)

    Schmitt, D R

    2001-01-01

    Although the elements of a fully stated rule (discriminative stimulus [S(D)], some behavior, and a consequence) can occur nearly contemporaneously with the statement of the rule, there is often a delay between the rule statement and the S(D). The effects of this delay on rule following have not been studied in behavior analysis, but they have been investigated in rule-like settings in the areas of prospective memory (remembering to do something in the future) and goal pursuit. Discriminative events for some behavior can be event based (a specific setting stimulus) or time based. The latter are more demanding with respect to intention following and show age-related deficits. Studies suggest that the specificity with which the components of a rule (termed intention) are stated has a substantial effect on intention following, with more detailed specifications increasing following. Reminders of an intention, too, are most effective when they refer specifically to both the behavior and its occasion. Covert review and written notes are two effective strategies for remembering everyday intentions, but people who use notes appear not to be able to switch quickly to covert review. By focusing on aspects of the setting and rule structure, research on prospective memory and goal pursuit expands the agenda for a more complete explanation of rule effects.

  12. Pseudotumoral delayed cerebral radionecrosis

    International Nuclear Information System (INIS)

    Ciaudo-Lacroix, C.; Lapresle, J.

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. γEG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed [fr

  13. Pseudotumoral delayed cerebral radionecrosis

    Energy Technology Data Exchange (ETDEWEB)

    Ciaudo-Lacroix, C; Lapresle, J [Centre Hospitalier de Bicetre, 94 - Le Kremlin-Bicetre (France)

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. ..gamma..EG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed.

  14. Stability and delay sensitivity of neutral fractional-delay systems.

    Science.gov (United States)

    Xu, Qi; Shi, Min; Wang, Zaihua

    2016-08-01

    This paper generalizes the stability test method via integral estimation for integer-order neutral time-delay systems to neutral fractional-delay systems. The key step in stability test is the calculation of the number of unstable characteristic roots that is described by a definite integral over an interval from zero to a sufficient large upper limit. Algorithms for correctly estimating the upper limits of the integral are given in two concise ways, parameter dependent or independent. A special feature of the proposed method is that it judges the stability of fractional-delay systems simply by using rough integral estimation. Meanwhile, the paper shows that for some neutral fractional-delay systems, the stability is extremely sensitive to the change of time delays. Examples are given for demonstrating the proposed method as well as the delay sensitivity.

  15. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy. Breast...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

  16. Delay tolerant networks

    CERN Document Server

    Gao, Longxiang; Luan, Tom H

    2015-01-01

    This brief presents emerging and promising communication methods for network reliability via delay tolerant networks (DTNs). Different from traditional networks, DTNs possess unique features, such as long latency and unstable network topology. As a result, DTNs can be widely applied to critical applications, such as space communications, disaster rescue, and battlefield communications. The brief provides a complete investigation of DTNs and their current applications, from an overview to the latest development in the area. The core issue of data forward in DTNs is tackled, including the importance of social characteristics, which is an essential feature if the mobile devices are used for human communication. Security and privacy issues in DTNs are discussed, and future work is also discussed.

  17. Diagnosis delay in Libyan female breast cancer.

    Science.gov (United States)

    Ermiah, Eramah; Abdalla, Fathi; Buhmeida, Abdelbaset; Larbesh, Entesar; Pyrhönen, Seppo; Collan, Yrjö

    2012-08-21

    To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008-2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time) was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay). Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire) during an interview with each patient and from medical records. The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3-6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer) was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s) that did not include a lump (p diagnosis, the clinical stage distribution was as follows: 9.0% stage I, 25.5% stage II, 54.0% stage III and 11.5% stage IV.Diagnosis delay was associated with bigger tumour size (p Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast

  18. Reperfusion delay in patients treated with primary percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Schoos, Mikkel M; Sejersten, Maria; Hvelplund, Anders

    2012-01-01

    identification number to emergency medical services (EMS) and National Board of Health databases in the period of 2005-2008. Patients were stratified according to transfer distances to PPCI into zone 1 (0-25 km), zone 2 (65-100 km) and zone 3 (101-185 km) and according to referral by pre-hospital triage. System...... the local hospital (219 (171-250)). System delay was an independent predictor of mortality (ppatients. PCI-related delay exceeded European Society of Cardiology (ESC) guidelines for patients living >100 km away and for non-directly referred......BACKGROUND: Reperfusion delay in ST-segment elevation myocardial infarction (STEMI) predicts adverse outcome. We evaluated time from alarm call (system delay) and time from first medical contact (PCI-related delay), where fibrinolysis could be initiated, to balloon inflation in a pre...

  19. Development of delayed radiation necrosis. Case report

    Energy Technology Data Exchange (ETDEWEB)

    Ohara, ShigFeki; Takagi, Terumasa [Meitetsu Hospital, Nagoya (Japan); Shibata, Taichiro; Nagai, Hajime

    1983-04-01

    The authors discussed the developing process of delayed radiation necrosis of the brain from the case of a 42-year-old female who developed intracranial hypertension and left hemiparesis 5 and a half years after radiotherapy for pituitary adenoma. The initial sign of radiation necrosis was from a CT scan taken 3 and a half years after radiotherapy showing an irregular low density lesion in the right temporal lobe. CT scan 2 years later demonstrated displacement of the midline structures to the left and a larger low density lesion with partially high density in the right MCA territory that was enhanced with intravenous contrast medium. Recovery after a right temporal lobectomy and administration of steroid hormone were uneventful. Eight months later there were no signs of raised intracranial pressure nor of neurological deficits. Tissues obtained from the right temporal lobe at lobectomy revealed the characteristic changes of delayed radiation necrosis; a mixture of fresh, recent, and old vascular lesions in the same specimen. From these findings, it was speculated that delayed radiation necrosis might initially occur within several years after radiotherapy and might gradually take a progressive and extended course, even in cases whose clinical symptoms develop much later.

  20. Development of free running differential. Development of differential with an actuator and a clutch which disconnects the traction; Free running defu no kaihatsu. Kirippanashi kiko oyobi actuator wo naizoshita differential sochi no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, N; Teraoka, M; Ishikawa, O; Nagaoka, T; Ugajin, K [Tochigi Fuji Sangyo Co. Ltd., Tochigi (Japan)

    1997-10-01

    Free Running Differential has an effect on fuel economy and noise reduction from drive line for four wheel drive vehicle. It has an actuator and a clutch which disconnects the traction from no driving side tire when two wheel drive is selected. this unit can be installed in conventional differential carrier with no design change. It is compact in design and low in cost. We evaluate it as having a dominant position among any other Free running system. 7 figs.

  1. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported...

  2. Modeling delay in genetic networks: from delay birth-death processes to delay stochastic differential equations.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Bennett, Matthew R; Josić, Krešimir; Ott, William

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  3. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Bennett, Matthew R. [Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77204, USA and Institute of Biosciences and Bioengineering, Rice University, Houston, Texas 77005 (United States); Josić, Krešimir [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204 (United States)

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  4. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    International Nuclear Information System (INIS)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William; Bennett, Matthew R.; Josić, Krešimir

    2014-01-01

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay

  5. Systematic of delayed neutron parameters

    International Nuclear Information System (INIS)

    Isaev, S.G.; Piksaikin, V.M.

    2000-01-01

    The experimental studies of the energy dependence of the delayed neutron (DN) parameters for various fission systems has shown that the behaviour of a some combination of delayed neutron parameters has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. It was presented the preliminary results which were obtained during study the physics interpretation of the results [ru

  6. Time Delay of CGM Sensors

    Science.gov (United States)

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  7. Solving the Linear 1D Thermoelasticity Equations with Pure Delay

    Directory of Open Access Journals (Sweden)

    Denys Ya. Khusainov

    2015-01-01

    Full Text Available We propose a system of partial differential equations with a single constant delay τ>0 describing the behavior of a one-dimensional thermoelastic solid occupying a bounded interval of R1. For an initial-boundary value problem associated with this system, we prove a well-posedness result in a certain topology under appropriate regularity conditions on the data. Further, we show the solution of our delayed model to converge to the solution of the classical equations of thermoelasticity as τ→0. Finally, we deduce an explicit solution representation for the delay problem.

  8. Asymptotic Behaviour and Extinction of Delay Lotka-Volterra Model with Jump-Diffusion

    OpenAIRE

    Dan Li; Jing’an Cui; Guohua Song

    2014-01-01

    This paper studies the effect of jump-diffusion random environmental perturbations on the asymptotic behaviour and extinction of Lotka-Volterra population dynamics with delays. The contributions of this paper lie in the following: (a) to consider delay stochastic differential equation with jumps, we introduce a proper initial data space, in which the initial data may be discontinuous function with downward jumps; (b) we show that the delay stochastic differential equation with jumps associate...

  9. Within-clutch variation in yolk testosterone as an adaptive maternal effect to modulate avian sibling competition: evidence from a comparative study.

    Science.gov (United States)

    Muller, Martina; Groothuis, Ton G G

    2013-01-01

    In many species, embryos are exposed to maternal hormones in utero, in the egg, or in the seed. In birds, mothers deposit substantial testosterone into their eggs, which enhances competitive ability of offspring. These maternal testosterone concentrations vary systematically within clutches in different patterns and may enable mothers to adaptively fine-tune competitive hierarchies within broods. We performed a comparative analysis to investigate this hypothesis using a broad set of avian species. We expected species with small size differences among siblings (arising from small hatching asynchrony or slow growth rates) to aim for survival of the whole brood in good years and therefore compensate last-hatching eggs with relatively more testosterone. We expected species with large size differences among siblings (large hatching asynchrony or fast growth rates) to produce surplus young as insurance against failed offspring and to facilitate elimination of redundant surplus young by bestowing last-hatching eggs with relatively less testosterone. As predicted, we found that maternal testosterone compensation to last-hatching eggs is stronger when size differences among siblings become smaller. Maternal testosterone compensation to last-hatching eggs also correlated negatively with hatching asynchrony and growth rates. These findings provide evidence for correlated evolution of several maternal effects that together support different maternal reproductive strategies.

  10. Variation in levels of reactive oxygen species is explained by maternal identity, sex and body-size-corrected clutch size in a lizard

    Science.gov (United States)

    Olsson, Mats; Wilson, Mark; Uller, Tobias; Mott, Beth; Isaksson, Caroline

    2009-01-01

    Many organisms show differences between males and females in growth rate and crucial life history parameters, such as longevity. Considering this, we may expect levels of toxic metabolic by-products of the respiratory chain, such as reactive oxygen species (ROS), to vary with age and sex. Here, we analyse ROS levels in female Australian painted dragon lizards ( Ctenophorus pictus) and their offspring using fluorescent probes and flow cytometry. Basal level of four ROS species (singlet oxygen, peroxynitrite, superoxide and H2O2) measured with a combined marker, and superoxide measured specifically, varied significantly among families but not between the sexes. When blood cells from offspring were chemically encouraged to accelerate the electron transport chain by mitochondrial uncoupling, net superoxide levels were three times higher in daughters than sons (resulting in levels outside of the normal ROS range) and varied among mothers depending on offspring sex (significant interaction between maternal identity and offspring sex). In offspring, there were depressive effects on ROS of size-controlled relative clutch size, which relies directly on circulating levels of vitellogenin, a confirmed antioxidant in some species. Thus, levels of reactive oxygen species varies among females, offspring and in relation to reproductive investment in a manner that makes its regulatory processes likely targets of selection.

  11. What ecological factors can affect albumen corticosterone levels in the clutches of seabirds? Timing of breeding, disturbance and laying order in rockhopper penguins (Eudyptes chrysocome chrysocome).

    Science.gov (United States)

    Poisbleau, M; Demongin, L; Angelier, F; Dano, S; Lacroix, A; Quillfeldt, P

    2009-06-01

    Female birds deposit corticosterone into their eggs. Elevated concentrations of this hormone may interfere with the development of their offspring, and mothers should thus regulate corticosterone levels deposited into the eggs adaptively. However, if females are unable to regulate deposition, then the corticosterone concentration in eggs should reflect that in female plasma and should be influenced by stressors to the females. We measured corticosterone levels in the albumen of rockhopper penguins, and assessed their relationship with hatching order, human disturbance and laying date. Rockhopper penguins (Eudyptes chrysocome chrysocome) lay two eggs, of which the second egg (B-egg) is larger and hatches faster than the first egg (A-egg). The chick hatching from the B-egg is also much more likely to survive than its sibling. Albumen corticosterone concentrations were lower in B-eggs. However, as B-eggs contained more albumen than A-eggs, the total corticosterone deposited in the albumen was not significantly different between the two eggs. Daily disturbance by human observers during albumen production did not influence albumen corticosterone levels. Laying date had an effect on total albumen corticosterone through a higher albumen mass. However, we observed a high individual component in the composition of eggs from the same clutch. Thus, more work is required to explore the hypotheses of passive versus active transfer to eggs and to understand the adaptive value of contrary effects on the amount and concentration of corticosterone.

  12. Energy management - The delayed flap approach

    Science.gov (United States)

    Bull, J. S.

    1976-01-01

    Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

  13. Relaxation periodic solutions of one singular perturbed system with delay

    Science.gov (United States)

    Kashchenko, A. A.

    2017-12-01

    In this paper, we consider a singularly perturbed system of two differential equations with delay, simulating two coupled oscillators with a nonlinear compactly supported feedback. We reduce studying nonlocal dynamics of initial system to studying dynamics of special finite-dimensional mappings: rough stable (unstable) cycles of these mappings correspond to exponentially orbitally stable (unstable) relaxation solutions of initial problem. We show that dynamics of initial model depends on coupling coefficient crucially. Multistability is proved.

  14. Delayed epidural hematoma after mild head injury

    Directory of Open Access Journals (Sweden)

    Radulović Danilo

    2005-01-01

    Full Text Available Background. Traumatic delayed epidural hematoma (DEH can be defined as insignificant or not seen on the initial CT scan performed after a trauma but seen on the subsequent CT scan as a “massive” epidural bleeding. Case report. We presented two cases of traumatic DEH after mild head injury. Both patients were conscious and without neurological deficit on the admission. Initial CT scan did not reveal intracranial hematoma. Repeated CT scan, that was performed after neurological deterioration, revealed epidural hematoma in both cases. The patients were operated with a favorable surgical outcome. Conclusion. Traumatic DEH could occur in the patients with head injuries who were conscious on the admission with a normal initial CT scan finding. Early detection of DEH and an urgent surgical evacuation were essential for a good outcome.

  15. Delayed Auditory Feedback and Movement

    Science.gov (United States)

    Pfordresher, Peter Q.; Dalla Bella, Simone

    2011-01-01

    It is well known that timing of rhythm production is disrupted by delayed auditory feedback (DAF), and that disruption varies with delay length. We tested the hypothesis that disruption depends on the state of the movement trajectory at the onset of DAF. Participants tapped isochronous rhythms at a rate specified by a metronome while hearing DAF…

  16. #FakeNobelDelayReasons

    CERN Multimedia

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  17. Picosecond resolution programmable delay line

    International Nuclear Information System (INIS)

    Suchenek, Mariusz

    2009-01-01

    The note presents implementation of a programmable delay line for digital signals. The tested circuit has a subnanosecond delay range programmable with a resolution of picoseconds. Implementation of the circuit was based on low-cost components, easily available on the market. (technical design note)

  18. Project delay analysis of HRSG

    Science.gov (United States)

    Silvianita; Novega, A. S.; Rosyid, D. M.; Suntoyo

    2017-08-01

    Completion of HRSG (Heat Recovery Steam Generator) fabrication project sometimes is not sufficient with the targeted time written on the contract. The delay on fabrication process can cause some disadvantages for fabricator, including forfeit payment, delay on HRSG construction process up until HRSG trials delay. In this paper, the author is using semi quantitative on HRSG pressure part fabrication delay with configuration plant 1 GT (Gas Turbine) + 1 HRSG + 1 STG (Steam Turbine Generator) using bow-tie analysis method. Bow-tie analysis method is a combination from FTA (Fault tree analysis) and ETA (Event tree analysis) to develop the risk matrix of HRSG. The result from FTA analysis is use as a threat for preventive measure. The result from ETA analysis is use as impact from fabrication delay.

  19. Delay and refusal of human papillomavirus vaccine for girls, national immunization survey-teen, 2010.

    Science.gov (United States)

    Dorell, Christina; Yankey, David; Jeyarajah, Jenny; Stokley, Shannon; Fisher, Allison; Markowitz, Lauri; Smith, Philip J

    2014-03-01

    Human papillomavirus (HPV) vaccine coverage among girls is low. We used data reported by parents of 4103 girls, 13 to 17 years old, to assess associations with, and reasons for, delaying or refusing HPV vaccination. Sixty-nine percent of parents neither delayed nor refused vaccination, 11% delayed only, 17% refused only, and 3% both delayed and refused. Eighty-three percent of girls who delayed only, 19% who refused only, and 46% who both delayed and refused went on to initiate the vaccine series or intended to initiate it within the next 12 months. A significantly higher proportion of parents of girls who were non-Hispanic white, lived in households with higher incomes, and had mothers with higher education levels, delayed and/or refused vaccination. The most common reasons for nonvaccination were concerns about lasting health problems from the vaccine, wondering about the vaccine's effectiveness, and believing the vaccine is not needed.

  20. Slow, slow, quick, quick, slow: Saudi Arabia's 'Gas Initiative'

    International Nuclear Information System (INIS)

    Robins, Philip

    2004-01-01

    This article sets out to analyse the Saudi gas initiative in the context of the decision-making process in Saudi Arabia between 1998 and 2002. It describes the overall context in which the initiative was made. It focuses on the personalities and institutions that were important in its birth and its evolution. The article argues that a mixture of personalities (especially that of Crown Prince Abdullah and foreign minister Saud al-Faisal) and institutions (especially a clutch of new bodies formed in 1999 and 2000) were pivotal in the emergence of the initiative. It also looks at the obstacles that were placed in the way of the initiative, arguing that Saudi Aramco and the minister of oil, Ali Naimi, were key blocking players. Over time, the Saudi gas initiative has come to be seen as a benchmark of the wider cause of economic liberalization in the Kingdom. The lack of progress in the initiative since the initial indicative contract awards in June 2001 has reflected the lack of movement in the general reformist strategy

  1. Delayed radiation neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, T.; Miyamoto, K.; Beppu, H.; Hirose, K.; Yamada, K. (Tokyo Metropolitan Neurological Hospital (Japan))

    1981-07-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author).

  2. Delayed radiation neuropathy

    International Nuclear Information System (INIS)

    Nagashima, Toshiko; Miyamoto, Kazuto; Beppu, Hirokuni; Hirose, Kazuhiko; Yamada, Katsuhiro

    1981-01-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author)

  3. Manufacturing Initiative

    Data.gov (United States)

    National Aeronautics and Space Administration — The Advanced Manufacturing Technologies (AMT) Project supports multiple activities within the Administration's National Manufacturing Initiative. A key component of...

  4. Attosecond Delays in Molecular Photoionization.

    Science.gov (United States)

    Huppert, Martin; Jordan, Inga; Baykusheva, Denitsa; von Conta, Aaron; Wörner, Hans Jakob

    2016-08-26

    We report measurements of energy-dependent photoionization delays between the two outermost valence shells of N_{2}O and H_{2}O. The combination of single-shot signal referencing with the use of different metal foils to filter the attosecond pulse train enables us to extract delays from congested spectra. Remarkably large delays up to 160 as are observed in N_{2}O, whereas the delays in H_{2}O are all smaller than 50 as in the photon-energy range of 20-40 eV. These results are interpreted by developing a theory of molecular photoionization delays. The long delays measured in N_{2}O are shown to reflect the population of molecular shape resonances that trap the photoelectron for a duration of up to ∼110 as. The unstructured continua of H_{2}O result in much smaller delays at the same photon energies. Our experimental and theoretical methods make the study of molecular attosecond photoionization dynamics accessible.

  5. Delayed somatic effects following extended radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Slanina, J

    1977-10-27

    A group of 135 patients was investigated, who suffered from Hodgkin's disease with long-term remission following radiotherapy. By restricting the investigations to the patient group with long-term remission and correlative examinations, differentiation was made between exclusive or principal delayed radiation effects and delayed effects due to other factors. The study reports the most significant results obtained in the fields of catamnesis, laboratory diagnostics, hematology, pulmology, cardiology, thyroid function tests, neurology, andrology and dermatology. Due to the numerous detectable delayed effects the group of patients with long-term remission receives a special status. Although those effects are in no proportion to the deletary risks of an untreated Hodgkin's disease and though they are consequently tolerable in the present state of the therapeutic development, they must initiate the completion of the therapeutic concept including performance of radiotherapy and aftercare, because only then the risk for the patient provoked by these effects, which ranges beyond the malignity of this disease can be reduced or prevented.

  6. Hopf Bifurcation and Delay-Induced Turing Instability in a Diffusive lac Operon Model

    Science.gov (United States)

    Cao, Xin; Song, Yongli; Zhang, Tonghua

    In this paper, we investigate the dynamics of a lac operon model with delayed feedback and diffusion effect. If the system is without delay or the delay is small, the positive equilibrium is stable so that there are no spatial patterns formed; while the time delay is large enough the equilibrium becomes unstable so that rich spatiotemporal dynamics may occur. We have found that time delay can not only incur temporal oscillations but also induce imbalance in space. With different initial values, the system may have different spatial patterns, for instance, spirals with one head, four heads, nine heads, and even microspirals.

  7. [Factors linked to delayed diagnosis of tuberculosis in Conakry (Guinea)].

    Science.gov (United States)

    Camara, A; Diallo, A; Camara, L M; Fielding, K; Sow, O Y; Chaperon, J

    2006-03-01

    Untreated smear-positive pulmonary tuberculosis constitutes a reservoir of infection which is highly contagious. The present study was conducted in Conakry, Guinea, to determine the different options which are available when seeking treatment or care, and to ascertain the average delay in diagnosis of pulmonary tuberculosis and the main factors linked to the delay in diagnosis after the initial onset of symptoms. Through a cross-sectional study, 113 consecutive patients with smear-positive pulmonary tuberculosis were interviewed through the use of a questionnaire. The median total delay from the onset of symptoms of pulmonary tuberculosis until the diagnosis was 11 weeks. This delay period exceeded 4 weeks for 90 of the patients (80%). The average delay linked to the conventional health care system was double that of the one at the fault of the patient (6 weeks versus 3 weeks, respectively). 54% of the patients had initially resorted to non-conventional care. To shorten this mean delay period, it is necessary to both strengthen the professional abilities and skills which train for one to better to detect tuberculosis and to sensitize the population to the subject matter and information on the illness and its symptoms.

  8. Initial management of breastfeeding.

    Science.gov (United States)

    Sinusas, K; Gagliardi, A

    2001-09-15

    Breast milk is widely accepted as the ideal source of nutrition for infants. In order to ensure success in breastfeeding, it is important that it be initiated as early as possible during the neonatal period. This is facilitated by skin-to-skin contact between the mother and infant immediately following birth. When possible, the infant should be allowed to root and latch on spontaneously within the first hour of life. Many common nursery routines such as weighing the infant, administration of vitamin K and application of ocular antibiotics can be safely delayed until after the initial breastfeeding. Postpartum care practices that improve breastfeeding rates include rooming-in, anticipatory guidance about breastfeeding problems and the avoidance of formula supplementation and pacifiers.

  9. Intra-clutch and inter-colony variability in element concentrations in eggshells of the black-headed gull, Chroicocephalus ridibundus, in northern Poland.

    Science.gov (United States)

    Kitowski, Ignacy; Indykiewicz, Piotr; Wiącek, Dariusz; Jakubas, Dariusz

    2017-04-01

    Eggshells are good bioindicators of environmental contamination, and therefore, the concentrations of 17 trace elements in 87 eggshells of black-headed gulls, Chroicocephalus ridibundus, were determined in five breeding colonies in an area dominated by farmland in northern Poland. The intra-clutch variability in the eggshell concentrations of heavy metals and other elements was also investigated, and the concentrations of the elements showed the following pattern: Ca > Mg > Sr > Fe > Zn > Al > Cr > Se > Mn > Cu > Pb > As > Ni > Mo = V > Sc > Cd. The concentrations of Fe, Al, and Mn decreased with the order in which the eggs were laid, but Sr concentrations increased. In contrast, the concentration of Cu significantly increased with the laying date. The concentrations of all elements significantly differed among the studied colonies; the highest concentration of eight elements was found in the eggshells from the Kusowo colony, which may have resulted from the intensive use of fertilizers, manure, and slurry in the surrounding agricultural region. The concentrations of Mg, Sr, and Zn in the eggshells from Skoki Duże were higher than those of the other studied colonies, which may have occurred because the gulls were nesting in a functioning gravel pit; soil and the parent rock are natural reservoirs of these elements. The observed element levels indicate that the environment where the black-headed gull eggs were formed, i.e., primarily near the breeding colonies, remains in a relatively unpolluted state, which was reflected by the low levels of Cd, Ni, and Pb and the lack of measurable levels of Hg.

  10. Delays and networked control systems

    CERN Document Server

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  11. Linear rotary optical delay lines

    Science.gov (United States)

    Guerboukha, Hichem; Qu, Hang; Skorobogatiy, Maksim

    2016-03-01

    We present a semi-analytical solution for the design of a high-speed rotary optical delay line that use a combination of two rotating curvilinear reflectors. We demonstrate that it is possible to design an infinite variety of the optical delay lines featuring linear dependence of the optical delay on the rotation angle. This is achieved via shape optimization of the rotating reflector surfaces. Moreover, a convenient spatial separation of the incoming and outgoing beams is possible. For the sake of example, we present blades that fit into a circle of 10cm diameter. Finally, a prototype of a rotary delay line is fabricated using CNC machining, and its optical properties are characterized.

  12. Systematics in delayed neutron yields

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Takaaki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.

    1998-03-01

    An attempt was made to reproduce the systematic trend observed in the delayed neutron yields for actinides on the basis of the five-Gaussian representation of the fission yield together with available data sets for delayed neutron emission probability. It was found that systematic decrease in DNY for heavier actinides is mainly due to decrease of fission yields of precursors in the lighter side of the light fragment region. (author)

  13. Analytical applications for delayed neutrons

    International Nuclear Information System (INIS)

    Eccleston, G.W.

    1983-01-01

    Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes

  14. Unilateral initiatives

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This paper reports on arms control which is generally thought of in terms of formal negotiations with an opponent, with the resulting agreements embodied in a treaty. This is not surprising, since arms control discussions between opponents are both important and politically visible. There are, however, strong reasons for countries to consider and frequently take unilateral initiatives. To do so is entirely consistent with the established major precepts of arms control which state that arms control is designed to reduce the risk of war, the costs of preparing for war, and the death and destruction if war should come. Unilateral initiatives on what weapons are purchased, which ones are eliminated and how forces are deployed can all relate to these objectives. There are two main categories of motives for unilateral initiatives in arms control. In one category, internal national objectives are the dominant, often sole, driving force; the initiative is undertaken for our own good

  15. Ports Initiative

    Science.gov (United States)

    EPA's Ports Initiative works in collaboration with the port industry, communities, and government to improve environmental performance and increase economic prosperity. This effort helps people near ports breath cleaner air and live better lives.

  16. Two-actor conflict with time delay: A dynamical model

    Science.gov (United States)

    Qubbaj, Murad R.; Muneepeerakul, Rachata

    2012-11-01

    Recent mathematical dynamical models of the conflict between two different actors, be they nations, groups, or individuals, have been developed that are capable of predicting various outcomes depending on the chosen feedback strategies, initial conditions, and the previous states of the actors. In addition to these factors, this paper examines the effect of time delayed feedback on the conflict dynamics. Our analysis shows that under certain initial and feedback conditions, a stable neutral equilibrium of conflict may destabilize for some critical values of time delay, and the two actors may evolve to new emotional states. We investigate the results by constructing critical delay surfaces for different sets of parameters and analyzing results from numerical simulations. These results provide new insights regarding conflict and conflict resolution and may help planners in adjusting and assessing their strategic decisions.

  17. Delay in the Diagnosis of Stable Slipped Capital Femoral Epiphysis.

    Science.gov (United States)

    Hosseinzadeh, Pooya; Iwinski, Henry J; Salava, Jonathon; Oeffinger, Donna

    2017-01-01

    Delays in the diagnosis of stable slipped capital femoral epiphysis (SCFE) is common due to the vague symptomatology and the lack of awareness of this entity by healthcare providers. Delays in the diagnosis of this condition can lead to poor outcomes for the patients. This study was designed to identify factors that contributed to delays in the diagnosis or the treatment of patients with SCFE seen at our institution. A retrospective chart review of patients with the diagnosis of a stable SCFE who had undergone screw stabilization between 1989 and 2010 at our hospital was performed. For each patient, demographic data, the date of initial onset of symptoms, the date of the first visit to the medical provider, the type of provider seen initially (orthopaedic surgeon or not), the date of diagnosis of SCFE, the type of physician who made the diagnosis (orthopaedic surgeon or not), and the date of surgery were recorded. For each patient, the presenting symptom was recorded as hip, thigh, or knee pain. The effect of demographic data, presenting symptoms, and the type of initial provider seen on the delay to diagnosis was studied using 2 Cox models. A total of 149 patients with 196 stable SCFE were included. The average time from the first physician visit to diagnosis was 94 days in the group seen by a nonorthopaedic provider compared with an average of 2.9 days in the group seen by an orthopaedist (Pprovider versus 97% in the group seen by orthopaedic surgeons. It took significantly longer to be diagnosed with SCFE in patients who presented with initial knee pain (P=0.0097) compared with those who presented with hip pain at the initial visit. This study shows a significant delay in the diagnosis of SCFE in the United States, particularly in patients seen by nonorthopaedic providers initially. Level III-prognostic.

  18. Considerable delay in diagnosis and acute management of subarachnoid haemorrhage

    DEFF Research Database (Denmark)

    Larsen, Carl Christian; Eskesen, Vagn; Hauerberg, John

    2010-01-01

    Rebleeding from subarachnoid haemorrhage (SAH) usually occurs within the first six hours after the initial bleeding. Rebleeding can be prevented effectively with tranexamic acid (TXA). Although a broad consensus has evolved that SAH should be treated as an emergency, it is likely that delays do...

  19. Semigroups on Frechet Spaces and Equations with Infinite Delays

    Indian Academy of Sciences (India)

    In this paper, we show existence and uniqueness of a solution to a functional differential equation with infinite delay. We choose an appropriate Frechet space so as to cover a large class of functions to be used as initial functions to obtain existence and uniqueness of solutions.

  20. Criteria for stability of linear dynamical systems with multiple delays ...

    African Journals Online (AJOL)

    In this study we considered a linear Dynamical system with multiple delays and find suitable conditions on the systems parameters such that for a given initial function, we can define a mapping in a carefully chosen complete metric space on which the mapping has a unique fixed point. An asymptotic stability theory for the ...

  1. The solutions of second-order linear differential systems with constant delays

    Science.gov (United States)

    Diblík, Josef; Svoboda, Zdeněk

    2017-07-01

    The representations of solutions to initial problems for non-homogenous n-dimensional second-order differential equations with delays x″(t )-2 A x'(t -τ )+(A2+B2)x (t -2 τ )=f (t ) by means of special matrix delayed functions are derived. Square matrices A and B are commuting and τ > 0. Derived representations use what is called a delayed exponential of a matrix and results generalize some of known results previously derived for homogenous systems.

  2. Hydrogen effect on tendency to delayed brittle fracture in titanium alloys

    International Nuclear Information System (INIS)

    Nazimov, O.P.; Bunin, L.A.; Il'in, A.A.; Ponomareva, N.A.

    1979-01-01

    The results of investigating hydrogen effetc on the tendency to delayed fracture of the titanium alloys of VT1-0, VT5, VT5-1, OT4, VT6S and VT14 are given. The delayed fracture test data have been compared with the results of fractographic investigations. The notion of structural instability in the initial condition during the tests was suggested as a criterion for evaluating the tendency of metal to delayed fracture

  3. Numerical study on the matching law between charge caliber and delay time of the rod-shaped explosively formed projectile

    Science.gov (United States)

    Shen, H. M.; Li, W. B.; Wang, X. M.; Li, W. B.

    2017-09-01

    To study the application of multi-point initiation technology on shaped charge warhead, numerically simulated the influence of initiating delay time of different charge caliber on detonation wave and performance forming of penetrator. The study found that as charge caliber increased, the allowable initiating delay time also increased. For the commonly used small and medium-charge caliber shaped charge warhead, the charge caliber(Dk ) and the delay time (σ) presented a linear relationship σ = -12.79+1.25Dk . As charge caliber continue increasing, the initiating allowable delay time started to increase exponentially. The study reveals the matching law between charge caliber, initiating delay time and performance forming of penetrator, and it offers guidance for the design of multi-point initiation network for shaped charge.

  4. UWB delay and multiply receiver

    Energy Technology Data Exchange (ETDEWEB)

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  5. Analysis and optimization of RC delay in vertical nanoplate FET

    Science.gov (United States)

    Woo, Changbeom; Ko, Kyul; Kim, Jongsu; Kim, Minsoo; Kang, Myounggon; Shin, Hyungcheol

    2017-10-01

    In this paper, we have analyzed short channel effects (SCEs) and RC delay with Vertical nanoplate FET (VNFET) using 3-D Technology computer-aided design (TCAD) simulation. The device is based on International Technology Road-map for Semiconductor (ITRS) 2013 recommendations, and it has initially gate length (LG) of 12.2 nm, channel thickness (Tch) of 4 nm, and spacer length (LSD) of 6 nm. To obtain improved performance by reducing RC delay, each dimension is adjusted (LG = 12.2 nm, Tch = 6 nm, LSD = 11.9 nm). It has each characteristic in this dimension (Ion/Ioff = 1.64 × 105, Subthreshold swing (S.S.) = 73 mV/dec, Drain-induced barrier lowering (DIBL) = 60 mV/V, and RC delay = 0.214 ps). Furthermore, with long shallow trench isolation (STI) length and thick insulator thickness (Ti), we can reduce RC delay from 0.214 ps to 0.163 ps. It is about a 23.8% reduction. Without decreasing drain current, there is a reduction of RC delay as reducing outer fringing capacitance (Cof). Finally, when source/drain spacer length is set to be different, we have verified RC delay to be optimum.

  6. Initial Study

    DEFF Research Database (Denmark)

    Torp, Kristian

    2009-01-01

    increased. In the initial study presented here, the time it takes to pass an intersection is studied in details. Two major signal-controlled four-way intersections in the center of the city Aalborg are studied in details to estimate the congestion levels in these intersections, based on the time it takes...

  7. Chaos in the delay logistic equation with discontinuous delays

    International Nuclear Information System (INIS)

    Sen, Ayan; Mukherjee, Debasis

    2009-01-01

    This paper analyzes a delay logistic equation which models a feedback control problem. Interval map associated to the system is derived. By calculating Lyapunov exponent, we indicate stable orbit and chaotic phenomenon respectively. The results are verified through computer simulation. We identify the parameter which controls the dynamics.

  8. Postraumatic delayed loss of vision

    International Nuclear Information System (INIS)

    Partington, C.R.; Graves, V.B.; Ruetenacht, D.A.; Weinstein, J.M.; Strother, C.M.

    1989-01-01

    The imaging studies and clinical findings in 10 patients who suffered delayed vision loss beginning 1 day to 13 years after head trauma have been reviewed. Two different primary lesions could be identified: pseudoaneurysm of the internal carotid artery and carotid cavernous fistula. The pathologic changes associated with pseudoaneurysm included compression of the optic nerves and/or chiasm by arterial aneurysm and intracranial hematoma. Carotid cavernous fistula caused delayed vision loss by compression of the optic nerves and chiasm by saccular dilatation of the cavernous sinus and by abnormal orbital venous drainage with retinal venous stasis, retinal edema, and glaucoma

  9. Time delayed Ensemble Nudging Method

    Science.gov (United States)

    An, Zhe; Abarbanel, Henry

    Optimal nudging method based on time delayed embedding theory has shows potentials on analyzing and data assimilation in previous literatures. To extend the application and promote the practical implementation, new nudging assimilation method based on the time delayed embedding space is presented and the connection with other standard assimilation methods are studied. Results shows the incorporating information from the time series of data can reduce the sufficient observation needed to preserve the quality of numerical prediction, making it a potential alternative in the field of data assimilation of large geophysical models.

  10. 49 CFR 236.563 - Delay time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  11. The Role of Covert Retrieval in Working Memory Span Tasks: Evidence from Delayed Recall Tests

    Science.gov (United States)

    McCabe, David P.

    2008-01-01

    The current study examined delayed recall of items that had been processed during simple and complex span tasks. Three experiments were reported showing that despite more items being recalled initially from a simple span task (i.e., word span) than a complex span task (i.e., operation span), on a delayed recall test more items were recalled that…

  12. Treatment delay of bone tumours, compilation of a sociodemographic risk profile: A retrospective study

    International Nuclear Information System (INIS)

    Schnurr, Christoph; Pippan, Mathias; Stuetzer, Hartmut; Delank, Karl S; Michael, Joern WP; Eysel, Peer

    2008-01-01

    Bone tumours are comparatively rare tumours and delays in diagnosis and treatment are common. The purpose of this study was to analyse sociodemographic risk factors for bone tumour patients in order to identify those at risk of prolonged patients delay (time span from first symptoms to consultation), professional delay (from consultation to treatment) or symptom interval (from first symptoms to treatment). Understanding these relationships might enable us to shorten time to diagnosis and therapy. We carried out a retrospective analysis of 265 patients with bone tumours documenting sociodemographic factors, patient delay, professional delay and symptom interval. A multivariate explorative Cox model was performed for each delay. Female gender was associated with a prolonged patient delay. Age under 30 years and rural living predisposes to a prolonged professional delay and symptom interval. Early diagnosis and prompt treatment are required for successful management of most bone tumour patients. We succeeded in identifying the histology independent risk factors of age under 30 years and rural habitation for treatment delay in bone tumour patients. Knowing about the existence of these risk groups age under 30 years and female gender could help the physician to diagnose bone tumours earlier. The causes for the treatment delays of patients living in a rural area have to be investigated further. If the delay initiates in the lower education of rural general physicians, further training about bone tumours might advance early detection. Hence the outcome of patients with bone tumours could be improved

  13. Early-delayed radiation rhombencephalopathy

    International Nuclear Information System (INIS)

    Nightingale, S.; Dawes, P.J.D.K.; Cartlidge, N.E.F.; Newcastle upon Tyne Univ.

    1982-01-01

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome. (author)

  14. Another definition for time delay

    International Nuclear Information System (INIS)

    Narnhofer, H.

    1980-01-01

    Time delay is defined by geometrical considerations which work in classical as well as in quantum mechanics, and its connection with the S-matrix and the virial is proven for potentials with V(x vector) and x vector V(x vector) vanishing as rsup(-1-epsilon) for r -> infinity. (Author)

  15. Weather delay costs to trucking.

    Science.gov (United States)

    2012-11-01

    Estimates of the nations freight sector of transportation range to upwards of $600 billion of total gross domestic product with 70 percent of total value and 60 percent of total weight moving by truck. Weather-related delays can add significantly ...

  16. Design flaw could delay collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "A magnet for the Large Hadron Collider (LHC) failed during a key test at the European particle physics laboratory CERN last week. Physicists and engineers will have to repair the damaged magnet and retrofit others to correct the underlynig design flaw, which could delay the start-up of the mammouth subterranean machine." (1,5 page)

  17. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    the delay is contractually defined as a contractor's risk, the contractor is liable to pay liquidated damages to the employer; if it is not, the contractor can under certain circumstances claim an extension of time and in some cases also economic compensation from the employer. The situation where a given...

  18. Deconstructing delayed posttraumatic stress disorder

    NARCIS (Netherlands)

    Smid, G

    2011-01-01

    According to the Diagnostic and Statistical Manual of Mental Disorders, delayed posttraumatic stress disorder (PTSD) must be diagnosed in individuals fulfilling criteria for PTSD if the onset of symptoms is at least six months after the trauma. The purpose of this thesis was to establish the

  19. Livermore blasted for project delay

    CERN Multimedia

    1999-01-01

    In a 12 page report issued last week, a review committee set up by the University of California has concluded that mismanagement and poor planning are to blame for significant cost overruns and delays in the construction of NIF, the worlds largest laser (1 page).

  20. Providing delay guarantees in Bluetooth

    NARCIS (Netherlands)

    Ait Yaiz, R.; Heijenk, Geert; Titsworth, F.

    2003-01-01

    Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network.

  1. Delayed Single Stage Perineal Posterior Urethroplasty

    International Nuclear Information System (INIS)

    Ali, S.; Shahnawaz; Shahzad, I.; Baloch, M. U.

    2015-01-01

    Objective: To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Study Design: Descriptive case series. Place and Duration of Study: Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Methodology: Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Results: Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patients age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3 percentage) experienced recurrent stricture during first 10 months. Five (16.6 percentage) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6 percentage) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3 percentage with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Conclusion: Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures. (author)

  2. Delayed Single Stage Perineal Posterior Urethroplasty.

    Science.gov (United States)

    Ali, Shahzad; Shahnawaz; Shahzad, Iqbal; Baloch, Muhammad Umar

    2015-06-01

    To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Descriptive case series. Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patient's age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3%) experienced recurrent stricture during first 10 months. Five (16.6%) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6%) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3% with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures.

  3. Theoretical foundations for traditional and generalized sensitivity functions for nonlinear delay differential equations.

    Science.gov (United States)

    Banks, H Thomas; Robbins, Danielle; Sutton, Karyn L

    2013-01-01

    In this paper we present new results for differentiability of delay systems with respect to initial conditions and delays. After motivating our results with a wide range of delay examples arising in biology applications, we further note the need for sensitivity functions (both traditional and generalized sensitivity functions), especially in control and estimation problems. We summarize general existence and uniqueness results before turning to our main results on differentiation with respect to delays, etc. Finally we discuss use of our results in the context of estimation problems.

  4. Analysis of a first-order delay differential-delay equation containing two delays

    Science.gov (United States)

    Marriott, C.; Vallée, R.; Delisle, C.

    1989-09-01

    An experimental and numerical analysis of the behavior of a two-delay differential equation is presented. It is shown that much of the system's behavior can be related to the stability behavior of the underlying linearized modes. A new phenomenon, mode crossing, is explored.

  5. Transcatheter Embolization for Delayed Hemorrhage Caused by Blunt Splenic Trauma

    International Nuclear Information System (INIS)

    Krohmer, Steven J.; Hoffer, Eric K.; Burchard, Kenneth W.

    2010-01-01

    Although the exact benefit of adjunctive splenic artery embolization (SAE) in the nonoperative management (NOM) of patients with blunt splenic trauma has been debated, the role of transcatheter embolization in delayed splenic hemorrhage is rarely addressed. The purpose of this study was to evaluate the effectiveness of SAE in the management of patients who presented at least 3 days after initial splenic trauma with delayed hemorrhage. During a 24-month period 4 patients (all male; ages 19-49 years) presented with acute onset of pain 5-70 days after blunt trauma to the left upper quadrant. Two had known splenic injuries that had been managed nonoperatively. All had computed axial tomography evidence of active splenic hemorrhage or false aneurysm on representation. All underwent successful SAE. Follow-up ranged from 28 to 370 days. These cases and a review of the literature indicate that SAE is safe and effective for NOM failure caused by delayed manifestations of splenic arterial injury.

  6. Deterministic Brownian motion generated from differential delay equations.

    Science.gov (United States)

    Lei, Jinzhi; Mackey, Michael C

    2011-10-01

    This paper addresses the question of how Brownian-like motion can arise from the solution of a deterministic differential delay equation. To study this we analytically study the bifurcation properties of an apparently simple differential delay equation and then numerically investigate the probabilistic properties of chaotic solutions of the same equation. Our results show that solutions of the deterministic equation with randomly selected initial conditions display a Gaussian-like density for long time, but the densities are supported on an interval of finite measure. Using these chaotic solutions as velocities, we are able to produce Brownian-like motions, which show statistical properties akin to those of a classical Brownian motion over both short and long time scales. Several conjectures are formulated for the probabilistic properties of the solution of the differential delay equation. Numerical studies suggest that these conjectures could be "universal" for similar types of "chaotic" dynamics, but we have been unable to prove this.

  7. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-11-09

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  8. Depressive illness delayed Hamlet's revenge.

    Science.gov (United States)

    Shaw, A B; Pickering, Neil

    2002-12-01

    If Hamlet had not delayed his revenge there would have been no play. Many explanations of the delay have been offered in the last four centuries. None is convincing. The interpretation which best fits the evidence best is that Hamlet was suffering from an acute depressive illness, with some obsessional features. He could not make a firm resolve to act. In Shakespeare's time there was no concept of acute depressive illness, although melancholy was well known. Melancholy, however, would have been seen as a character defect. In the tragic model the hero brings himself and others to ruin because of a character defect. Thus, at the time, the play conformed to the tragic model. With today's knowledge, it does not. This analysis adds to, but does not replace, other insights into the play.

  9. Air congestion delay: a review

    Directory of Open Access Journals (Sweden)

    Daniel Alberto Pamplona

    2016-04-01

    Full Text Available This article is a literature review of the air congestion delay and its costs. Air congestion is a worldwide problem. Its existence brings costs for airlines and discomfort for passengers. With the increasing demand for air transport, the study of air congestion has attracted the attention of many researchers around the world. The cause for the delays is erroneously attributed only to the lack of infrastructure investments. The literature review shows that other factors such as population growth, increasing standards of living, lack of operational planning and environmental issues exercise decisive influence. Several studies have been conducted in order to analyze and propose solutions to this problem that affects society as a whole.

  10. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-08

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  11. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong; Sundaramoorthi, Ganesh

    2017-01-01

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  12. Stabilizing embedology: Geometry-preserving delay-coordinate maps

    Science.gov (United States)

    Eftekhari, Armin; Yap, Han Lun; Wakin, Michael B.; Rozell, Christopher J.

    2018-02-01

    Delay-coordinate mapping is an effective and widely used technique for reconstructing and analyzing the dynamics of a nonlinear system based on time-series outputs. The efficacy of delay-coordinate mapping has long been supported by Takens' embedding theorem, which guarantees that delay-coordinate maps use the time-series output to provide a reconstruction of the hidden state space that is a one-to-one embedding of the system's attractor. While this topological guarantee ensures that distinct points in the reconstruction correspond to distinct points in the original state space, it does not characterize the quality of this embedding or illuminate how the specific parameters affect the reconstruction. In this paper, we extend Takens' result by establishing conditions under which delay-coordinate mapping is guaranteed to provide a stable embedding of a system's attractor. Beyond only preserving the attractor topology, a stable embedding preserves the attractor geometry by ensuring that distances between points in the state space are approximately preserved. In particular, we find that delay-coordinate mapping stably embeds an attractor of a dynamical system if the stable rank of the system is large enough to be proportional to the dimension of the attractor. The stable rank reflects the relation between the sampling interval and the number of delays in delay-coordinate mapping. Our theoretical findings give guidance to choosing system parameters, echoing the tradeoff between irrelevancy and redundancy that has been heuristically investigated in the literature. Our initial result is stated for attractors that are smooth submanifolds of Euclidean space, with extensions provided for the case of strange attractors.

  13. Estimation of time- and state-dependent delays and other parameters in functional differential equations

    Science.gov (United States)

    Murphy, K. A.

    1990-01-01

    A parameter estimation algorithm is developed which can be used to estimate unknown time- or state-dependent delays and other parameters (e.g., initial condition) appearing within a nonlinear nonautonomous functional differential equation. The original infinite dimensional differential equation is approximated using linear splines, which are allowed to move with the variable delay. The variable delays are approximated using linear splines as well. The approximation scheme produces a system of ordinary differential equations with nice computational properties. The unknown parameters are estimated within the approximating systems by minimizing a least-squares fit-to-data criterion. Convergence theorems are proved for time-dependent delays and state-dependent delays within two classes, which say essentially that fitting the data by using approximations will, in the limit, provide a fit to the data using the original system. Numerical test examples are presented which illustrate the method for all types of delay.

  14. Does delayed pushing in the second stage of labor impact perinatal outcomes?

    Science.gov (United States)

    Frey, Heather A; Tuuli, Methodius G; Cortez, Sarah; Odibo, Anthony O; Roehl, Kimberly A; Shanks, Anthony L; Macones, George A; Cahill, Alison G

    2012-11-01

    To estimate maternal, neonatal, and labor outcomes associated with delayed pushing. A retrospective cohort study of all consecutive women admitted to a single institution in labor at term who reached the second stage of labor. Pregnancies with multiple fetuses or major anomalies were excluded. Delayed pushing was defined as initiation of pushing ≥60 minutes after complete dilatation. Primary outcome was mode of delivery. Multivariable logistic regression was used to control for confounding. Of the 5290 women who met inclusion criteria, 471 (8.9%) employed delayed pushing, and 4819 (91.1%) pushed immediately. Delayed pushing was associated with increased rates of cesarean, operative vaginal delivery, maternal fever, and lower arterial cord pH. Duration of the second stage and length of time spent pushing were significantly longer with delayed pushing. Delayed pushing is associated with lower rates of spontaneous vaginal delivery and increased adverse maternal and neonatal outcomes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  15. Teriparatide Induced Delayed Persistent Hypercalcemia

    Directory of Open Access Journals (Sweden)

    Nirosshan Thiruchelvam

    2014-01-01

    Full Text Available Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  16. Assembly delay line pulse generators

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  17. Inter-electrode delay estimators for electrohysterographic propagation analysis

    International Nuclear Information System (INIS)

    Rabotti, Chiara; Mischi, Massimo; Bergmans, Jan W M; Van Laar, Judith O E H; Oei, Guid S

    2009-01-01

    Premature birth is a major cause of mortality and permanent dysfunctions. Several parameters derived from single channel electrohysterographic (EHG) signals have been considered to determine contractions leading to preterm delivery. The results are promising, but improvements are needed. As effective uterine contractions result from a proper action potential propagation, in this paper we focus on the propagation properties of EHG signals, which can be predictive of preterm delivery. Two standard delay estimators, namely maximization of the cross-correlation function and spectral matching, are adapted and implemented for the assessment of inter-electrode delays of propagating EHG signals. The accuracy of the considered standard estimators might be hampered by a poor inter-channel correlation. An improved dedicated approach is therefore proposed. By simultaneous adaptive estimation of the volume conductor transfer function and the delay, a dedicated method is conceived for improving the inter-channel signal similarity during delay calculation. Furthermore, it provides delay estimates without resolution limits and it is suitable for low sampling rates, which are appropriate for EHG recording. The three estimators were evaluated on EHG signals recorded on seven women. The dedicated approach provided more accurate estimates due to a 22% improvement of the initial average inter-channel correlation

  18. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  19. Synchronization in networks with heterogeneous coupling delays

    Science.gov (United States)

    Otto, Andreas; Radons, Günter; Bachrathy, Dániel; Orosz, Gábor

    2018-01-01

    Synchronization in networks of identical oscillators with heterogeneous coupling delays is studied. A decomposition of the network dynamics is obtained by block diagonalizing a newly introduced adjacency lag operator which contains the topology of the network as well as the corresponding coupling delays. This generalizes the master stability function approach, which was developed for homogenous delays. As a result the network dynamics can be analyzed by delay differential equations with distributed delay, where different delay distributions emerge for different network modes. Frequency domain methods are used for the stability analysis of synchronized equilibria and synchronized periodic orbits. As an example, the synchronization behavior in a system of delay-coupled Hodgkin-Huxley neurons is investigated. It is shown that the parameter regions where synchronized periodic spiking is unstable expand when increasing the delay heterogeneity.

  20. Openness initiative

    International Nuclear Information System (INIS)

    Duncan, S.S.

    1995-01-01

    Although antinuclear campaigns seem to be effective, public communication and education efforts on low-level radioactive waste have mixed results. Attempts at public information programs on low-level radioactive waste still focus on influencing public opinion. A question then is: open-quotes Is it preferable to have a program focus on public education that will empower individuals to make informed decisions rather than trying to influence them in their decisions?close quotes To address this question, a case study with both quantitative and qualitative data will be used. The Ohio Low-Level Radioactive Waste Education Program has a goal to provide people with information they want/need to make their own decisions. The program initiated its efforts by conducting a statewide survey to determine information needed by people and where they turned for that information. This presentation reports data from the survey and then explores the program development process in which programs were designed and presented using the information. Pre and post data from the programs reveal attitude and knowledge shifts

  1. Openness initiative

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, S.S. [Los Alamos National Lab., NM (United States)

    1995-12-31

    Although antinuclear campaigns seem to be effective, public communication and education efforts on low-level radioactive waste have mixed results. Attempts at public information programs on low-level radioactive waste still focus on influencing public opinion. A question then is: {open_quotes}Is it preferable to have a program focus on public education that will empower individuals to make informed decisions rather than trying to influence them in their decisions?{close_quotes} To address this question, a case study with both quantitative and qualitative data will be used. The Ohio Low-Level Radioactive Waste Education Program has a goal to provide people with information they want/need to make their own decisions. The program initiated its efforts by conducting a statewide survey to determine information needed by people and where they turned for that information. This presentation reports data from the survey and then explores the program development process in which programs were designed and presented using the information. Pre and post data from the programs reveal attitude and knowledge shifts.

  2. Initiative hard coal; Initiative Steinkohle

    Energy Technology Data Exchange (ETDEWEB)

    Leonhardt, J.

    2007-08-02

    In order to decrease the import dependence of hard coal in the European Union, the author has submitted suggestions to the director of conventional sources of energy (directorate general for energy and transport) of the European community, which found a positive resonance. These suggestions are summarized in an elaboration 'Initiative Hard Coal'. After clarifying the starting situation and defining the target the presupposition for a better use of hard coal deposits as raw material in the European Union are pointed out. On that basis concrete suggestions for measures are made. Apart from the conditions of the deposits it concerns thereby also new mining techniques and mining-economical developments, connected with tasks for the mining-machine industry. (orig.)

  3. Maximal monotone model with delay term of convolution

    Directory of Open Access Journals (Sweden)

    Claude-Henri Lamarque

    2005-01-01

    Full Text Available Mechanical models are governed either by partial differential equations with boundary conditions and initial conditions (e.g., in the frame of continuum mechanics or by ordinary differential equations (e.g., after discretization via Galerkin procedure or directly from the model description with the initial conditions. In order to study dynamical behavior of mechanical systems with a finite number of degrees of freedom including nonsmooth terms (e.g., friction, we consider here problems governed by differential inclusions. To describe effects of particular constitutive laws, we add a delay term. In contrast to previous papers, we introduce delay via a Volterra kernel. We provide existence and uniqueness results by using an Euler implicit numerical scheme; then convergence with its order is established. A few numerical examples are given.

  4. Synchronization analysis of coloured delayed networks under ...

    Indian Academy of Sciences (India)

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that ...

  5. Management Strategies to Facilitate Optimal Outcomes for Patients Treated with Delayed-release Dimethyl Fumarate.

    Science.gov (United States)

    Mayer, Lori; Fink, Mary Kay; Sammarco, Carrie; Laing, Lisa

    2018-04-01

    Delayed-release dimethyl fumarate is an oral disease-modifying therapy that has demonstrated significant efficacy in adults with relapsing-remitting multiple sclerosis. Incidences of flushing and gastrointestinal adverse events are common in the first month after delayed-release dimethyl fumarate initiation. Our objective was to propose mitigation strategies for adverse events related to initiation of delayed-release dimethyl fumarate in the treatment of patients with multiple sclerosis. Studies of individually developed mitigation strategies and chart reviews were evaluated. Those results, as well as mitigation protocols developed at multiple sclerosis care centers, are summarized. Key steps to optimize the effectiveness of delayed-release dimethyl fumarate treatment include education prior to and at the time of delayed-release dimethyl fumarate initiation, initiation dose protocol gradually increasing to maintenance dose, dietary suggestions for co-administration with food, gastrointestinal symptom management with over-the-counter medications, flushing symptom management with aspirin, and temporary dose reduction. Using the available evidence from clinical trials and evaluations of post-marketing studies, these strategies to manage gastrointestinal and flushing symptoms can be effective and helpful to the patient when initiating delayed-release dimethyl fumarate.

  6. A Parameter Robust Method for Singularly Perturbed Delay Differential Equations

    Directory of Open Access Journals (Sweden)

    Erdogan Fevzi

    2010-01-01

    Full Text Available Uniform finite difference methods are constructed via nonstandard finite difference methods for the numerical solution of singularly perturbed quasilinear initial value problem for delay differential equations. A numerical method is constructed for this problem which involves the appropriate Bakhvalov meshes on each time subinterval. The method is shown to be uniformly convergent with respect to the perturbation parameter. A numerical example is solved using the presented method, and the computed result is compared with exact solution of the problem.

  7. Delayed radiographic diagnosis of osteoid osteoma in the lumbar spine

    International Nuclear Information System (INIS)

    Louis-Ugbo, J.; Reddy, A.S.; Heller, J.G.

    1998-01-01

    Study design: Case report and literature review. Objectives: Describe a case of delayed diagnosis of osteoid osteoma of the spine due to misinterpretation of initial imaging studies within two months of onset of pain, and discuss the relevant imaging characteristics and their pitfalls. Summary of background data. Several cases of delayed diagnosis have been previously reported. Only one false negative bone scan has been reported; however other imaging modalities established the diagnosis. In our patient, all of the imaging modalities were initially interpreted as negative hence the delay in diagnosis. Methods: History, physical examination and imaging studies (x-rays, bone scan, MRI) of the patient were employed to evaluate the differential diagnosis of low back pain and sciatica in a 16 yr old. Repeat bone scan and CT scan were done six months after onset of symptoms because of persistent clinical suspicion of osteoid osteoma. Results: The repeat bone scan and CT scan confirmed-the diagnosis missed, during the first round of imaging. An osteoid osteoma of the L5 pedicle was removed without incident. Conclusion: Technetium bone scans remain the main stay of early diagnosis of osteoid osteoma when plain films and other imaging modalities are normal. However, when faced with persistent unexplained musculoskeletal pain in an adolescent, further follow-up and diagnostic efforts are indicated; possibly repeating a bone scan if initially interpreted as negative. (author)

  8. Delayed traumatic hematomas of the brain: the early manifestations of CT

    International Nuclear Information System (INIS)

    Liu Shuyan; Tang Guangjian; Fu Jiazhen; Xu Bing; Yin Yanyu

    2002-01-01

    Objective: To study the CT manifestations of delayed traumatic hematomas of the brain and evaluate their diagnostic significance in predicting the delayed traumatic brain hematoma. Methods: The manifestations of initial CT studies and follow-up CT examinations of 31 delayed traumatic brain hematomas were analyzed. Another 50 CT studies of head trauma without delayed brain hematomas were included randomly as control. Results: The abnormal findings of CT studies of the 31 delayed traumatic brain hematomas included: (1) Decreased density of the local brain parenchyma and disappeared difference between gray and white matter of the same area in 18 cases; (2) Local subarachnoid space hemorrhage in 24 cases; (3) Slight mass effect of local brain parenchyma in 16 cases. (4) Subdural hematoma in 9 cases. The locations of the abnormalities were roughly the same with the delayed hematoma except one local subarachnoid space hemorrhage, which was in the opposite of the delayed hematoma. The appearing rate of those abnormal findings in the control group was low and the difference was statistically significant. Conclusion: The decrease of density of local brain parenchyma, the disappeared difference between the gray and white matter, local subarachnoid space hemorrhage, and local swollen of brain presented in the initial CT study of the patient with heat trauma should be taken as indicators of delayed hemorrhage of the same area of brain, and it is necessary to do follow-up CT studies to exclude it

  9. Delay Variation Model with Two Service Queues

    Directory of Open Access Journals (Sweden)

    Filip Rezac

    2010-01-01

    Full Text Available Delay in VoIP technology is very unpleasant issue and therefore a voice packets prioritization must be ensured. To maintain the high call quality a maximum information delivery time from the sender to the recipient is set to 150 ms. This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, their generation, facilities and mathematical formulations. A new approach to the delay variation model is presented and its validation has been done by experimention.

  10. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design trends move towards nanometer technologies, more number of new parameters affects the delay of the component. Fuzzy delay models are ideal for modelling the uncertainty found in the design and manufacturing steps.

  11. Delayed speech development in children: Introduction to terminology

    Directory of Open Access Journals (Sweden)

    M. Yu. Bobylova

    2017-01-01

    Full Text Available There has been recently an increase in the number of children diagnosed with delayed speech development. There is delay compensation with age, but mild deficiency often remains for life. Delayed speech development is more common in boys than in girls. Its etiology is unknown in most cases, so a child should be followed up to make an accurate diagnosis. Genetic predisposition or environmental factors frequently influence speech development. The course of its delays is various. In the history of a number of disorders (childhood disintegrative disorder, Landau–Kleffner syndrome, there is evidence for the normal development of speech to a certain period and then stops or even regresses. By way of comparison, there are generally speech developmental changes in autism even during the preverbal stage (a complex of revival fails to form; babbling is poor, low emotional, gibberish; at the same time, the baby recipes whole phrases without using them to communicate. These speech disorders are considered not only as a delay, but also as a developmental abnormality. Speech disorders in children should be diagnosed as early as possible in order to initiative corrective measures in time. In this case, a physician makes a diagnosis and a special education teacher does corrective work. The successful collaboration and mutual understanding of the specialists in these areas will determine quality of life for a child in the future. This paper focusses on the terminology and classification of delays, which are necessary for physicians and teachers to speak the same language.

  12. Tunable Optical True-Time Delay Devices Would Exploit EIT

    Science.gov (United States)

    Kulikov, Igor; DiDomenico, Leo; Lee, Hwang

    2004-01-01

    Tunable optical true-time delay devices that would exploit electromagnetically induced transparency (EIT) have been proposed. Relative to prior true-time delay devices (for example, devices based on ferroelectric and ferromagnetic materials) and electronically controlled phase shifters, the proposed devices would offer much greater bandwidths. In a typical envisioned application, an optical pulse would be modulated with an ultra-wideband radio-frequency (RF) signal that would convey the information that one seeks to communicate, and it would be required to couple differently delayed replicas of the RF signal to the radiating elements of a phased-array antenna. One or more of the proposed devices would be used to impose the delays and/or generate the delayed replicas of the RF-modulated optical pulse. The beam radiated or received by the antenna would be steered by use of a microprocessor-based control system that would adjust operational parameters of the devices to tune the delays to the required values. EIT is a nonlinear quantum optical interference effect that enables the propagation of light through an initially opaque medium. A suitable medium must have, among other properties, three quantum states (see Figure 1): an excited state (state 3), an upper ground state (state 2), and a lower ground state (state 1). These three states must form a closed system that exhibits no decays to other states in the presence of either or both of two laser beams: (1) a probe beam having the wavelength corresponding to the photon energy equal to the energy difference between states 3 and 1; and (2) a coupling beam having the wavelength corresponding to the photon energy equal to the energy difference between states 3 and 2. The probe beam is the one that is pulsed and modulated with an RF signal.

  13. Precise delay measurement through combinatorial logic

    Science.gov (United States)

    Burke, Gary R. (Inventor); Chen, Yuan (Inventor); Sheldon, Douglas J. (Inventor)

    2010-01-01

    A high resolution circuit and method for facilitating precise measurement of on-chip delays for FPGAs for reliability studies. The circuit embeds a pulse generator on an FPGA chip having one or more groups of LUTS (the "LUT delay chain"), also on-chip. The circuit also embeds a pulse width measurement circuit on-chip, and measures the duration of the generated pulse through the delay chain. The pulse width of the output pulse represents the delay through the delay chain without any I/O delay. The pulse width measurement circuit uses an additional asynchronous clock autonomous from the main clock and the FPGA propagation delay can be displayed on a hex display continuously for testing purposes.

  14. Reasons for diagnostic delay in gynecological malignancies

    DEFF Research Database (Denmark)

    Vandborg, Mai Partridge; Christensen, René dePont Christensen; Kragstrup, Jakob

    2011-01-01

    (≤ or > 60 years), performance of gynecological examination by the GP and notification of cancer suspicion on first referral from GP’s on the diagnostic delay (short delay ≤90 days and long delay >90 days). Results Across cancer type a median total delay of 101 days was observed. The 10% of women......Aim The primary aim of this study was to identify and describe different delay types in women with gynecologic cancer, and to analyze the relationship between diagnostic delay and a number of characteristics for patients, cancers and the health care system. Setting A cohort study of women newly......) and The Danish Gynecological Cancer Database (DGCD). 161 women were included; ovarian cancer: 63, endometrial cancer: 50, cervical cancer: 34 and vulvar cancer: 14. Outcome measures were different delay types counted in days and the influence of four clinical important variables: Presence of alarm symptoms, age...

  15. Temperature Dependent Wire Delay Estimation in Floorplanning

    DEFF Research Database (Denmark)

    Winther, Andreas Thor; Liu, Wei; Nannarelli, Alberto

    2011-01-01

    Due to large variations in temperature in VLSI circuits and the linear relationship between metal resistance and temperature, the delay through wires of the same length can be different. Traditional thermal aware floorplanning algorithms use wirelength to estimate delay and routability. In this w......Due to large variations in temperature in VLSI circuits and the linear relationship between metal resistance and temperature, the delay through wires of the same length can be different. Traditional thermal aware floorplanning algorithms use wirelength to estimate delay and routability....... In this work, we show that using wirelength as the evaluation metric does not always produce a floorplan with the shortest delay. We propose a temperature dependent wire delay estimation method for thermal aware floorplanning algorithms, which takes into account the thermal effect on wire delay. The experiment...

  16. Elite athletes and pubertal delay.

    Science.gov (United States)

    Kapczuk, Karina

    2017-10-01

    Intensive physical training and participation in competitive sports during childhood and early adolescence may affect athletes' pubertal development. On the other hand, pubertal timing, early or late, may impact on an athlete selection for a particular sport. Genetic predisposition, training load, nutritional status and psychological stress determine athletes' pubertal timing. Athletes that practice esthetic sports, especially gymnasts, are predisposed to a delay in pubertal development. The growing evidence indicates that energy deficiency, not a systemic training per se, plays a crucial role in the pathogenesis of functional hypothalamic hypogonadism in female athletes. Metabolic and psychologic stress activate hypothalamic-pituitary-adrenal axis and suppress hypothalamic-pituitary-ovarian axis. Female athletes who do not begin secondary sexual development by the age of 14 or menstruation by the age of 16 warrant a comprehensive evaluation and a targeted treatment. Somatic growth and sexual maturation of elite female athletes are largely sport-specific since each sport favors a particular somatotype and requires a specific training. Chronic negative energy balance resulting from a systemic physical training and inadequate energy intake may delay pubertal development in elite athletes. Youth athletes, especially those engaged in competitive sports that emphasize prepubertal or lean appearance, are at risk of developing relative energy deficiency in sport associated with disordered eating or eating disorders. Management strategies should address the complex conditions underlying functional hypothalamic hypogonadism.

  17. Delayed recombination and cosmic parameters

    International Nuclear Information System (INIS)

    Galli, Silvia; Melchiorri, Alessandro; Bean, Rachel; Silk, Joseph

    2008-01-01

    Current cosmological constraints from cosmic microwave background anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination, altering the cosmic ionization history and the cosmological inferences drawn from the cosmic microwave background data. We show that for recent observations of the cosmic microwave background anisotropy, from the Wilkinson microwave anisotropy probe satellite mission (WMAP) 5-year survey and from the arcminute cosmology bolometer array receiver experiment, additional resonance radiation is nearly degenerate with variations in the spectral index, n s , and has a marked effect on uncertainties in constraints on the Hubble constant, age of the universe, curvature and the upper bound on the neutrino mass. When a modified recombination scheme is considered, the redshift of recombination is constrained to z * =1078±11, with uncertainties in the measurement weaker by 1 order of magnitude than those obtained under the assumption of standard recombination while constraints on the shift parameter are shifted by 1σ to R=1.734±0.028. From the WMAP5 data we obtain the following constraints on the resonance and ionization sources parameters: ε α i <0.058 at 95% c.l.. Although delayed recombination limits the precision of parameter estimation from the WMAP satellite, we demonstrate that this should not be the case for future, smaller angular scales measurements, such as those by the Planck satellite mission.

  18. Asymptotic Delay Analysis for Cross-Layer Delay-Based Routing in Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Philippe Jacquet

    2007-01-01

    Full Text Available This paper addresses the problem of the evaluation of the delay distribution via analytical means in IEEE 802.11 wireless ad hoc networks. We show that the asymptotic delay distribution can be expressed as a power law. Based on the latter result, we present a cross-layer delay estimation protocol and we derive new delay-distribution-based routing algorithms, which are well adapted to the QoS requirements of real-time multimedia applications. In fact, multimedia services are not sensitive to average delays, but rather to the asymptotic delay distributions. Indeed, video streaming applications drop frames when they are received beyond a delay threshold, determined by the buffer size. Although delay-distribution-based routing is an NP-hard problem, we show that it can be solved in polynomial time when the delay threshold is large, because of the asymptotic power law distribution of the link delays.

  19. Temporal-contextual processing in working memory: evidence from delayed cued recall and delayed free recall tests.

    Science.gov (United States)

    Loaiza, Vanessa M; McCabe, David P

    2012-02-01

    Three experiments are reported that addressed the nature of processing in working memory by investigating patterns of delayed cued recall and free recall of items initially studied during complex and simple span tasks. In Experiment 1, items initially studied during a complex span task (i.e., operation span) were more likely to be recalled after a delay in response to temporal-contextual cues, relative to items from subspan and supraspan list lengths in a simple span task (i.e., word span). In Experiment 2, items initially studied during operation span were more likely to be recalled from neighboring serial positions during delayed free recall than were items studied during word span trials. Experiment 3 demonstrated that the number of attentional refreshing opportunities strongly predicts episodic memory performance, regardless of whether the information is presented in a spaced or massed format in a modified operation span task. The results indicate that the content-context bindings created during complex span trials reflect attentional refreshing opportunities that are used to maintain items in working memory.

  20. Differing influence on delays in the case-finding process for tuberculosis between general physicians and specialists in Mongolia.

    Science.gov (United States)

    Enkhbat, S; Toyota, M; Yasuda, N; Ohara, H

    1997-06-01

    The objective of this study is to compare the influence on delays in the tuberculosis case-finding process according to the types of medical facilities initially visited. The subjects include 107 patients 16 years and older who were diagnosed with bacteriologically confirmed pulmonary tuberculosis at nine tuberculosis specialized facilities in Ulaanbaatar, Mongolia from May 1995 to March 1996. Patients were interviewed about their demographic and socioeconomic factors and their medical records were reviewed for measuring delays. Fifty-five patients initially consulted general physicians and the remaining 52 patients initially visited other types of facilities including tuberculosis specialized facilities. Patients who initially consulted general physicians had shorter patient's delays and longer doctor's delays than those who had visited other facilities first. Since the reduction of patient's delay outweighs the extension of doctor's delay among patients who initially consulted general physicians, their total delay was shorter than that of patients who visited other facilities first. The beneficial influence of consulting general physicians first on the total delay was observed after adjusting for patient's age, sex, residence area, family income and family history of tuberculosis. This finding indicates that general physicians play an important role in improving the passive case-finding process in Mongolia.

  1. Cell cycle related /sup 125/IUDR-induced-division delay

    International Nuclear Information System (INIS)

    Scheniderman, M.H.; Hofer, K.G.

    1987-01-01

    A series of experiments were run to determine if /sup 125/I-decays, in /sup 125/IUdR labeled DNA, specifically accumulated at 1, 3, 5, 7 and 9 hours after plating labeled mitotic cells caused a change in the rate or time of cell entry into mitosis. To accomplish this, a pool of labeled mitotic cells was selected in mitosis and plated in replicate flasks. /sup 125/I decays were accumulated in groups of cells by cooling (4 0 C) for 2 hours starting at the designated times. After rewarding, colcemid was added to arrest cells in mitosis. The rate of cell progression into mitosis for each cell cycle time of accumulation was determined by scoring the mitotic index of cells sampled as a function of time after addition of the colcemid. The results are summarized: (1) Decays from /sup 125/I in /sup 125/I(UdR) labeled DNA reduced the rate of cell progression into mitosis and delayed the time of initiation of mitosis. (2) The reduced rate of progression and the delayed time of initiation of mitosis were independent of the cell cycle time that /sup 125/I-decays were accumulated. (3) The reduced rate of progression after cell cycle accumulation of /sup 125/I decay was statistically indistinguishable from the corresponding controls. (4) The delayed initiation of mitosis after specific cell cycle accumulation of /sup 125/I- decays was greater than the corresponding control. The relationship of these data to DNA and non-DNA division delay target(s) is emphasized

  2. High mortality during tuberculosis treatment does not indicate long diagnostic delays in Vietnam: a cohort study

    Directory of Open Access Journals (Sweden)

    Sy Dinh N

    2007-08-01

    Full Text Available Abstract Background Delay in tuberculosis diagnosis and treatment initiation may increase disease severity and mortality. In evaluations of tuberculosis control programmes high fatality rates during tuberculosis treatment, are used as an indicator of long delays in low HIV-prevalence settings. However, data for this presumed association between delay and fatality are lacking. We assessed the association between diagnostic delay and mortality of new smear-positive pulmonary tuberculosis patients in Vietnam. Methods Follow-up of a patient cohort included in a survey of diagnostic delay in 70 randomly selected districts. Data on diagnosis and treatment were extracted from routine registers. Patients who had died during the course of treatment were compared to those with reported cure, completed treatment or failure (survivors. Results Complete data were available for 1881/2093 (89.9% patients, of whom 82 (4.4% had died. Fatality was 4.5% for patients with ≤ 4 weeks delay, 5.0% for 5- ≤ 8 weeks delay (aOR 1.11, 95%CI 0.67–1.84 and 3.2% for > 9 weeks delay (aOR 0.69, 95%CI 0.37–1.30. Fatality tended to decline with increasing delay but this was not significant. Fatality was not associated with median diagnostic delay at district level (Spearman's rho = -0.08, P = 0.5. Conclusion Diagnostic delay is not associated with treatment mortality in Vietnam at individual nor district level, suggesting that high case fatality should not be used as an indicator of long diagnostic delay in national tuberculosis programmes.

  3. Construction delays: a case study in the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Luiz Mauricio Furtado Maués

    Full Text Available Abstract he construction industry is one of the industrial sectors with the lowest rates of fulfilment of contract deadlines, especially in developing countries. This fact has been the focus of considerable discussions seeking to identify the causes of the delays. The main purpose of this paper is to use factor analysis to identify the factors that are correlated with delay, contemplating exclusively residential real estate projects and using a city in the Brazilian Amazon as a case study. Based on the database from the government agency that authorises constructions in the city of Belém (City Planning Department - Secretaria Municipal de Urbanismo, SEURB and data from construction companies, the study investigated 274 construction projects from the past 11 years. Factor analysis and work with the variables that can be identified and measured in the initial phase of the project, i.e., during the feasibility study, demonstrate that the physical characteristics of the apartments and the construction project are the primary causes for variations in construction delays; these causes have not yet been reported in the literature. We hope that the results of this study will contribute to more consistent forecasting of construction time, minimising the risk of delays.

  4. Blood Transfusion Delay and Outcome in County Hospitals in Kenya.

    Science.gov (United States)

    Thomas, Julius; Ayieko, Philip; Ogero, Morris; Gachau, Susan; Makone, Boniface; Nyachiro, Wycliffe; Mbevi, George; Chepkirui, Mercy; Malla, Lucas; Oliwa, Jacquie; Irimu, Grace; English, Mike

    2017-02-08

    Severe anemia is a leading indication for blood transfusion and a major cause of hospital admission and mortality in African children. Failure to initiate blood transfusion rapidly enough contributes to anemia deaths in sub-Saharan Africa. This article examines delays in accessing blood and outcomes in transfused children in Kenyan hospitals. Children admitted with nonsurgical conditions in 10 Kenyan county hospitals participating in the Clinical Information Network who had blood transfusion ordered from September 2013 to March 2016 were studied. The delay in blood transfusion was calculated from the date when blood transfusion was prescribed to date of actual transfusion. Five percent (2,875/53,174) of admissions had blood transfusion ordered. Approximately half (45%, 1,295/2,875) of children who had blood transfusion ordered at admission had a documented hemoglobin transfusions, 82% were administered and documented in clinical records, and three-quarters of these (75%, 1,760/2,352) were given on the same day as ordered but these proportions varied from 71% to 100% across the 10 hospitals. Children who had a transfusion ordered but did not receive the prescribed transfusion had a mortality of 20%, compared with 12% among those transfused. Malaria-associated anemia remains the leading indication for blood transfusion in acute childhood illness admissions. Delays in transfusion are common and associated with poor outcomes. Variance in delay across hospitals may be a useful indicator of health system performance. © The American Society of Tropical Medicine and Hygiene.

  5. Humans Optimize Decision-Making by Delaying Decision Onset

    Science.gov (United States)

    Teichert, Tobias; Ferrera, Vincent P.; Grinband, Jack

    2014-01-01

    Why do humans make errors on seemingly trivial perceptual decisions? It has been shown that such errors occur in part because the decision process (evidence accumulation) is initiated before selective attention has isolated the relevant sensory information from salient distractors. Nevertheless, it is typically assumed that subjects increase accuracy by prolonging the decision process rather than delaying decision onset. To date it has not been tested whether humans can strategically delay decision onset to increase response accuracy. To address this question we measured the time course of selective attention in a motion interference task using a novel variant of the response signal paradigm. Based on these measurements we estimated time-dependent drift rate and showed that subjects should in principle be able trade speed for accuracy very effectively by delaying decision onset. Using the time-dependent estimate of drift rate we show that subjects indeed delay decision onset in addition to raising response threshold when asked to stress accuracy over speed in a free reaction version of the same motion-interference task. These findings show that decision onset is a critical aspect of the decision process that can be adjusted to effectively improve decision accuracy. PMID:24599295

  6. Delayed Development of Pneumothorax After Pulmonary Radiofrequency Ablation

    International Nuclear Information System (INIS)

    Clasen, Stephan; Kettenbach, Joachim; Kosan, Bora; Aebert, Hermann; Schernthaner, Melanie; Kroeber, Stefan-Martin; Boemches, Andrea; Claussen, Claus D.; Pereira, Philippe L.

    2009-01-01

    Acute pneumothorax is a frequent complication after percutaneous pulmonary radiofrequency (RF) ablation. In this study we present three cases showing delayed development of pneumothorax after pulmonary RF ablation in 34 patients. Our purpose is to draw attention to this delayed complication and to propose a possible approach to avoid this major complication. These three cases occurred subsequent to 44 CT-guided pulmonary RF ablation procedures (6.8%) using either internally cooled or multitined expandable RF electrodes. In two patients, the pneumothorax, being initially absent at the end of the intervention, developed without symptoms. One of these patients required chest drain placement 32 h after RF ablation, and in the second patient therapy remained conservative. In the third patient, a slight pneumothorax at the end of the intervention gradually increased and led into tension pneumothorax 5 days after ablation procedure. Underlying bronchopleural fistula along the coagulated former electrode track was diagnosed in two patients. In conclusion, delayed development of pneumothorax after pulmonary RF ablation can occur and is probably due to underlying bronchopleural fistula, potentially leading to tension pneumothorax. Patients and interventionalists should be prepared for delayed onset of this complication, and extensive track ablation following pulmonary RF ablation should be avoided.

  7. Operating Room Delays: Meaningful Use in Electronic Health Record.

    Science.gov (United States)

    Van Winkle, Rachelle A; Champagne, Mary T; Gilman-Mays, Meri; Aucoin, Julia

    2016-06-01

    Perioperative areas are the most costly to operate and account for more than 40% of expenses. The high costs prompted one organization to analyze surgical delays through a retrospective review of their new electronic health record. Electronic health records have made it easier to access and aggregate clinical data; 2123 operating room cases were analyzed. Implementing a new electronic health record system is complex; inaccurate data and poor implementation can introduce new problems. Validating the electronic health record development processes determines the ease of use and the user interface, specifically related to user compliance with the intent of the electronic health record development. The revalidation process after implementation determines if the intent of the design was fulfilled and data can be meaningfully used. In this organization, the data fields completed through automation provided quantifiable, meaningful data. However, data fields completed by staff that required subjective decision making resulted in incomplete data nearly 24% of the time. The ease of use was further complicated by 490 permutations (combinations of delay types and reasons) that were built into the electronic health record. Operating room delay themes emerged notwithstanding the significant complexity of the electronic health record build; however, improved accuracy could improve meaningful data collection and a more accurate root cause analysis of operating room delays. Accurate and meaningful use of data affords a more reliable approach in quality, safety, and cost-effective initiatives.

  8. On SIP Session setup delay for VoIP services over correlated fading channels

    DEFF Research Database (Denmark)

    Fathi, Hanane; Chakraborty, Shyam S.; Prasad, Ramjee

    2006-01-01

    In this paper, the session setup delay of the session initiation protocol (SIP) is studied. The transmissions on both the forward and reverse channel are assumed to experience Markovian errors. The session setup delay is evaluated for different transport protocols, and with the use of the radio...... link protocol (RLP). An adaptive retransmission timer is used to optimize SIP performances. Using numerical results, we find that SIP over user datagram protocol (UDP) instead of transport control protocol (TCP) can make the session setup up to 30% shorter. Also, RLP drastically reduces the session...... setup delay down to 4 to 5 s, even in environments with high frame error rates (10%) and significant correlation in the fading process (fDT=0.02). SIP is compared with its competitor H.323. SIP session setup delay with compressed messages outperforms H.323 session setup delay....

  9. Delayed chest wall hematoma caused by progressive displacement of rib fractures after blunt trauma

    Directory of Open Access Journals (Sweden)

    Nobuhiro Sato

    2016-06-01

    Full Text Available Rib fracture is a common injury resulting from blunt thoracic trauma. Although hemothorax and pneumothorax are known delayed complications of rib fracture, delayed chest wall hematoma has rarely been reported. We discuss the case of an 81-year-old woman who was not undergoing antiplatelet or anticoagulant therapy who presented to our emergency department after a traffic injury. This patient had a nondisplaced rib fracture that went undetected on the initial computed tomography scan; the development of progressive displacement led to hemorrhagic shock due to delayed chest wall hematoma. The chest wall hematoma was effectively diagnosed and treated via contrast-enhanced computed tomography and angiographic embolization. This case highlights the possibility of this potential delayed complication from a common injury such as a rib fracture. Keywords: Angiography, Chest wall, Delayed complication, Rib fracture, Thoracic injury

  10. New distributions of the statistical time delay of electrical breakdown in nitrogen

    International Nuclear Information System (INIS)

    Markovic, V Lj; Gocic, S R; Stamenkovic, S N

    2006-01-01

    Two new distributions of the statistical time delay of electrical breakdown in nitrogen are reported in this paper. The Gaussian and Gauss-exponential distributions of statistical time delay have been obtained on the basis of thousands of time delay measurements on a gas tube with a plane-parallel electrode system. Distributions of the statistical time delay are theoretically founded on binomial distribution for the occurrence of initiating electrons and described by using simple analytical and numerical models. The shapes of distributions depend on the electron yields in the interelectrode space originating from residual states. It is shown that a distribution of the statistical time delay changes from exponential and Gauss-exponential to Gaussian distribution due to the influence of residual ionization

  11. Dynamics of Nonlinear Time-Delay Systems

    CERN Document Server

    Lakshmanan, Muthusamy

    2010-01-01

    Synchronization of chaotic systems, a patently nonlinear phenomenon, has emerged as a highly active interdisciplinary research topic at the interface of physics, biology, applied mathematics and engineering sciences. In this connection, time-delay systems described by delay differential equations have developed as particularly suitable tools for modeling specific dynamical systems. Indeed, time-delay is ubiquitous in many physical systems, for example due to finite switching speeds of amplifiers in electronic circuits, finite lengths of vehicles in traffic flows, finite signal propagation times in biological networks and circuits, and quite generally whenever memory effects are relevant. This monograph presents the basics of chaotic time-delay systems and their synchronization with an emphasis on the effects of time-delay feedback which give rise to new collective dynamics. Special attention is devoted to scalar chaotic/hyperchaotic time-delay systems, and some higher order models, occurring in different bran...

  12. Group Delay of High Q Antennas

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert Frølund

    2013-01-01

    Group Delay variations versus frequency is an essential factor which can cause distortion and degradation in the signals. Usually this is an issue in wideband communication systems, such as satellite communication systems, which are used for transmitting wideband data. However, group delay can also...... become an issue, when working with high Q antennas, because of the steep phase shift over the frequency. In this paper, it is measured how large group delay variations can become, when going from a low Q antenna to a high Q antenna. The group delay of a low Q antenna is shown to be around 1.3 ns, whereas...... a high Q antenna has group delay of around 22 ns. It is due to this huge group delay variation characteristics of high Q antennas, that signal distortion might occur in the radio system with high Q antennas....

  13. Permutation entropy with vector embedding delays

    Science.gov (United States)

    Little, Douglas J.; Kane, Deb M.

    2017-12-01

    Permutation entropy (PE) is a statistic used widely for the detection of structure within a time series. Embedding delay times at which the PE is reduced are characteristic timescales for which such structure exists. Here, a generalized scheme is investigated where embedding delays are represented by vectors rather than scalars, permitting PE to be calculated over a (D -1 ) -dimensional space, where D is the embedding dimension. This scheme is applied to numerically generated noise, sine wave and logistic map series, and experimental data sets taken from a vertical-cavity surface emitting laser exhibiting temporally localized pulse structures within the round-trip time of the laser cavity. Results are visualized as PE maps as a function of embedding delay, with low PE values indicating combinations of embedding delays where correlation structure is present. It is demonstrated that vector embedding delays enable identification of structure that is ambiguous or masked, when the embedding delay is constrained to scalar form.

  14. Delays in the management of retroperitoneal sarcomas

    DEFF Research Database (Denmark)

    Seinen, Jojanneke; Almquist, Martin; Styring, Emelie

    2010-01-01

    Retroperitoneal sarcomas are rare and treatment should optimally be centralized. Despite successful centralization with 90% of the patients referred prior to surgery, delays occur, which led us to assess lead times in a population-based series. Method. Patients diagnosed with retroperitoneal...... sarcoma in the southern Sweden health care region 2003-2009 were eligible for the study. Data on referrals and diagnostic investigations were collected from clinical files from primary health care, local hospitals, and from the sarcoma centre. Lead times were divided into patient delays and health care...... delays caused by primary health care, local hospitals, or procedures at the sarcoma centre. Results. Complete data were available from 33 patients and demonstrated a median patient delay of 23¿days (0-17¿months) and median health care delay of 94¿days (1-40¿months) with delays of median 15¿days...

  15. Time Delay Estimation Algoritms for Echo Cancellation

    Directory of Open Access Journals (Sweden)

    Kirill Sakhnov

    2011-01-01

    Full Text Available The following case study describes how to eliminate echo in a VoIP network using delay estimation algorithms. It is known that echo with long transmission delays becomes more noticeable to users. Thus, time delay estimation, as a part of echo cancellation, is an important topic during transmission of voice signals over packetswitching telecommunication systems. An echo delay problem associated with IP-based transport networks is discussed in the following text. The paper introduces the comparative study of time delay estimation algorithm, used for estimation of the true time delay between two speech signals. Experimental results of MATLab simulations that describe the performance of several methods based on cross-correlation, normalized crosscorrelation and generalized cross-correlation are also presented in the paper.

  16. CGI delay compensation. [Computer Generated Image

    Science.gov (United States)

    Mcfarland, R. E.

    1986-01-01

    Computer-generated graphics in real-time helicopter simulation produces objectionable scene-presentation time delays. In the flight simulation laboratory at Ames Research Center, it has been determined that these delays have an adverse influence on pilot performance during agressive tasks such as nap of the earth (NOE) maneuvers. Using contemporary equipment, computer generated image (CGI) time delays are an unavoidable consequence of the operations required for scene generation. However, providing that magnitude distortions at higher frequencies are tolerable, delay compensation is possible over a restricted frequency range. This range, assumed to have an upper limit of perhaps 10 or 15 rad/sec, conforms approximately to the bandwidth associated with helicopter handling qualities research. A compensation algorithm is introduced here and evaluated in terms of tradeoffs in frequency responses. The algorithm has a discrete basis and accommodates both a large, constant transport delay interval and a periodic delay interval, as associated with asynchronous operations.

  17. Memorized discrete systems and time-delay

    CERN Document Server

    Luo, Albert C J

    2017-01-01

    This book examines discrete dynamical systems with memory—nonlinear systems that exist extensively in biological organisms and financial and economic organizations, and time-delay systems that can be discretized into the memorized, discrete dynamical systems. It book further discusses stability and bifurcations of time-delay dynamical systems that can be investigated through memorized dynamical systems as well as bifurcations of memorized nonlinear dynamical systems, discretization methods of time-delay systems, and periodic motions to chaos in nonlinear time-delay systems. The book helps readers find analytical solutions of MDS, change traditional perturbation analysis in time-delay systems, detect motion complexity and singularity in MDS; and determine stability, bifurcation, and chaos in any time-delay system.

  18. Delayed Posthypoxic Leukoencephalopathy: Improvement with Antioxidant Therapy

    Directory of Open Access Journals (Sweden)

    Franklin King

    2015-12-01

    Full Text Available Introduction: Delayed posthypoxic leukoencephalopathy (DPHL may result from a variety of hypoxic insults, including respiratory depression from an opiate overdose. The underlying pathophysiological mechanism of DPHL remains uncertain. We describe a patient with a typical case of DPHL who responded clinically to antioxidant treatment. Methods: Clinical, serological, and radiographic investigations were undertaken in the evaluation of the patient. Results: A 63-year-old man developed altered mental status 10 days following recovery from an opiate overdose and aspiration pneumonia that required intubation. The clinical course and brain imaging were consistent with DPHL. Initiation of antioxidant therapy with vitamin E, vitamin C, B-complex vitamins, and coenzyme Q10 coincided with the prompt reversal of clinical deterioration. Conclusions: The potential therapeutic effect of antioxidants on DPHL needs to be explored in future cases. If this relationship indeed holds true, it would be consistent with the hypothesis that formation of reactive oxygen species during reperfusion plays a role in the pathophysiology of this disorder.

  19. Magnetic pulse sharpener and delay-line

    International Nuclear Information System (INIS)

    Li Jin; Dai Guangsen; Xia Liansheng

    2002-01-01

    This paper describes a method to achieve short rise time pulse which has been delayed with a delay-line and magnetic pulse sharpener. A delay-line and two shock-lines are designed to carry pulsed signal with a maximum voltage magnitude up to 80 kV. A pulse of High voltage with arise time of 48 ns at a level of 0.1%-0.9% were achieved, and the attenuation in the line is very small

  20. Does Bilingualism Delay the Development of Dementia?

    OpenAIRE

    Amy L Atkinson

    2016-01-01

    It has been suggested that bilingualism (where individuals speak two languages) may delay the development of dementia. However, much of the research is inconclusive. Some researchers have reported that bilingualism delays the onset and diagnosis of dementia, whilst other studies have found weak or even detrimental effects. This paper reviews a series of nine empirical studies, published up until March 2016, which investigated whether bilingualism significantly delays the onset of dementia. Th...

  1. Delayed enhanced MRI in intraparenchymal tumors

    International Nuclear Information System (INIS)

    Eguchi, Takahiko; Morimoto, Tetsuya; Takeshima, Toshikazu

    1991-01-01

    Delayed enhanced MRI was performed on 20 intraparenchymal tumors, and these findings were compared with those of early enhanced MRI. Using the spin-echo technique (SE: 400-500/20 msec), early scans were obtained 5 minutes, and delayed scans were obtained 60 minutes, after the intravenous injection of 0.1 nmol of gadolinium-DTPA/Kg. We discussed the changes in the delayed scan with regard to the change in the pattern of enhancement and the boundary of enhancement. In these twenty intraparenchymal tumors, there were three low-grade astrocytomas, two anaplastic astrocytomas, seven glioblastomas, and eight metastatic tumors. The changes in the enhanced pattern showed three types as follows: Type I: heterogeneous enhancement in both early and delayed scans; Type II: heterogeneous enhancement in early scan and homogeneous enhancement in delayed scan; Type III: homogeneous enhancement in both early and delayed scans. Most malignant tumors, such as glioblastomas (6/8), anaplastic astrocytomas (2/2), and metastatic tumors (7/8), revealed Type I, although low-grade astrocytomas showed Type II (3/2) and Type III (1/3). The heterogeneous enhancement in delayed scan was found in malignant tumors and in low-grade astrocytoma; even if the early scan revealed heterogeneous enhancement, the delayed scan showed homogeneous enhancement. In the delayed scan, most enhanced boundaries spread out of the boundaries in the early scan. Glioblastomas spread markedly in the delayed scan, although none of the low-grade astrocytomas, anaplastic astrocytomas, or metastases revealed marked spreading. We called these marked increases in the delayed scan a 'spreading sign' and thought that this sign was specific to glioblastomas. Recently some authors have emphasized the usefulness of serial scans. Delayed enhanced MRI 60 minutes after the administration of a contrast medium was here found also to be useful for the accurate diagnosis for brain tumors. (author)

  2. A Job with a Future? Delay Discounting, Magnitude Effects, and Domain Independence of Utility for Career Decisions.

    Science.gov (United States)

    Schoenfelder, Thomas E.; Hantula, Donald A.

    2003-01-01

    Seniors (n=20) assessed two job offers with differences in domain (salary/tasks), delay (career-long earnings), and magnitude (initial salary offer). Contrary to discounted utility theory, choices reflected nonconstant discount rates for future salary/tasks (delay effect), lower discount rates for salary/preferred tasks (magnitude effect), and a…

  3. Lyapunov matrices approach to the parametric optimization of time-delay systems

    Directory of Open Access Journals (Sweden)

    Duda Józef

    2015-09-01

    Full Text Available In the paper a Lyapunov matrices approach to the parametric optimization problem of time-delay systems with a P-controller is presented. The value of integral quadratic performance index of quality is equal to the value of Lyapunov functional for the initial function of the time-delay system. The Lyapunov functional is determined by means of the Lyapunov matrix

  4. Estimation of delays and other parameters in nonlinear functional differential equations

    Science.gov (United States)

    Banks, H. T.; Lamm, P. K. D.

    1983-01-01

    A spline-based approximation scheme for nonlinear nonautonomous delay differential equations is discussed. Convergence results (using dissipative type estimates on the underlying nonlinear operators) are given in the context of parameter estimation problems which include estimation of multiple delays and initial data as well as the usual coefficient-type parameters. A brief summary of some of the related numerical findings is also given.

  5. A semi-analytical approach for solving of nonlinear systems of functional differential equations with delay

    Science.gov (United States)

    Rebenda, Josef; Šmarda, Zdeněk

    2017-07-01

    In the paper, we propose a correct and efficient semi-analytical approach to solve initial value problem for systems of functional differential equations with delay. The idea is to combine the method of steps and differential transformation method (DTM). In the latter, formulas for proportional arguments and nonlinear terms are used. An example of using this technique for a system with constant and proportional delays is presented.

  6. A note on Burgers' equation with time delay: Instability via finite-time blow-up

    International Nuclear Information System (INIS)

    Jordan, P.M.

    2008-01-01

    Burgers' equation with time delay is considered. Using the Cole-Hopf transformation, the exact solution of this nonlinear partial differential equation (PDE) is determined in the context of a (seemingly) well-posed initial-boundary value problem (IBVP) involving homogeneous Dirichlet data. The solution obtained, however, is shown to exhibit a delay-induced instability, suffering blow-up in finite-time

  7. Diagnostic and treatment delay among pulmonary tuberculosis patients in Ethiopia: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Yimer Solomon

    2005-12-01

    Full Text Available Abstract Background Delayed diagnosis and treatment of tuberculosis (TB results in severe disease and a higher mortality. It also leads to an increased period of infectivity in the community. The objective of this study was to determine the length of delays, and analyze the factors affecting the delay from onset of symptoms of pulmonary tuberculosis (PTB until the commencement of treatment. Methods In randomly selected TB management units (TBMUs, i.e. government health institutions which have diagnosing and treatment facilities for TB in Amhara Region, we conducted a cross sectional study from September 1-December 31/2003. Delay was analyzed from two perspectives, 1. Period between onset of TB symptoms to first visit to any health provider (health seeking period, and from the first health provider visit to initiation of treatment (health providers' delay, and 2. Period between onset of TB symptoms to first visit to a medical provider (patients' delay, and from this visit to commencement of anti-TB treatment (health systems' delay. Patients were interviewed on the same date of diagnosis using a semi-structured questionnaire. Logistics regression analysis was applied to analyze the risk factors of delays. Results A total of 384 new smear positive PTB patients participated in the study. The median total delay was 80 days. The median health-seeking period and health providers' delays were 15 and 61 days, respectively. Conversely, the median patients' and health systems' delays were 30 and 21 days, respectively. Taking medical providers as a reference point, we found that forty eight percent of the subjects delayed for more than one month. Patients' delays were strongly associated with first visit to non-formal health providers and self treatment (P Conclusion Delay in the diagnosis and treatment of PTB is unacceptably high in Amhara region. Health providers' and health systems' delays represent the major portion of the total delay. Accessing a

  8. Neutron stochastic transport theory with delayed neutrons

    International Nuclear Information System (INIS)

    Munoz-Cobo, J.L.; Verdu, G.

    1987-01-01

    From the stochastic transport theory with delayed neutrons, the Boltzmann transport equation with delayed neutrons for the average flux emerges in a natural way without recourse to any approximation. From this theory a general expression is obtained for the Feynman Y-function when delayed neutrons are included. The single mode approximation for the particular case of a subcritical assembly is developed, and it is shown that Y-function reduces to the familiar expression quoted in many books, when delayed neutrons are not considered, and spatial and source effects are not included. (author)

  9. Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting.

    Science.gov (United States)

    Negash, Sesen; Sheppard, Nicole Van Ness; Lambert, Nathaniel M; Fincham, Frank D

    2016-01-01

    Internet pornography is a multi-billion-dollar industry that has grown increasingly accessible. Delay discounting involves devaluing larger, later rewards in favor of smaller, more immediate rewards. The constant novelty and primacy of sexual stimuli as particularly strong natural rewards make Internet pornography a unique activator of the brain's reward system, thereby having implications for decision-making processes. Based on theoretical studies of evolutionary psychology and neuroeconomics, two studies tested the hypothesis that consuming Internet pornography would relate to higher rates of delay discounting. Study 1 used a longitudinal design. Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2 tested for causality with an experimental design. Participants were randomly assigned to abstain from either their favorite food or pornography for three weeks. Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards. Theoretical and clinical implications of these studies are highlighted.

  10. Stability analysis of impulsive fuzzy cellular neural networks with distributed delays and reaction-diffusion terms

    International Nuclear Information System (INIS)

    Li Zuoan; Li Kelin

    2009-01-01

    In this paper, we investigate a class of impulsive fuzzy cellular neural networks with distributed delays and reaction-diffusion terms. By employing the delay differential inequality with impulsive initial conditions and M-matrix theory, we find some sufficient conditions ensuring the existence, uniqueness and global exponential stability of equilibrium point for impulsive fuzzy cellular neural networks with distributed delays and reaction-diffusion terms. In particular, the estimate of the exponential converging index is also provided, which depends on the system parameters. An example is given to show the effectiveness of the results obtained here.

  11. System delay and mortality among patients with STEMI treated with primary percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Terkelsen, Christian Juhl; Sørensen, Jacob Thorsted; Maeng, Michael

    2010-01-01

    Timely reperfusion therapy is recommended for patients with ST-segment elevation myocardial infarction (STEMI), and door-to-balloon delay has been proposed as a performance measure in triaging patients for primary percutaneous coronary intervention (PCI). However, focusing on the time from first...... contact with the health care system to the initiation of reperfusion therapy (system delay) may be more relevant, because it constitutes the total time to reperfusion modifiable by the health care system. No previous studies have focused on the association between system delay and outcome in patients...

  12. Moving source localization with a single hydrophone using multipath time delays in the deep ocean.

    Science.gov (United States)

    Duan, Rui; Yang, Kunde; Ma, Yuanliang; Yang, Qiulong; Li, Hui

    2014-08-01

    Localizing a source of radial movement at moderate range using a single hydrophone can be achieved in the reliable acoustic path by tracking the time delays between the direct and surface-reflected arrivals (D-SR time delays). The problem is defined as a joint estimation of the depth, initial range, and speed of the source, which are the state parameters for the extended Kalman filter (EKF). The D-SR time delays extracted from the autocorrelation functions are the measurements for the EKF. Experimental results using pseudorandom signals show that accurate localization results are achieved by offline iteration of the EKF.

  13. Optimal control for parabolic-hyperbolic system with time delay

    International Nuclear Information System (INIS)

    Kowalewski, A.

    1985-07-01

    In this paper we consider an optimal control problem for a system described by a linear partial differential equation of the parabolic-hyperbolic type with time delay in the state. The right-hand side of this equation and the initial conditions are not continuous functions usually, but they are measurable functions belonging to L 2 or Lsup(infinity) spaces. Therefore, the solution of this equation is given by a certain Sobolev space. The time delay in the state is constant, but it can be also a function of time. The control time T is fixed in our problem. Making use of the Milutin-Dubovicki theorem, necessary and sufficient conditions of optimality with the quadratic performance functional and constrained control are derived for the Dirichlet problem. The flow chart of the algorithm which can be used in the numerical solving of certain optimization problems for distributed systems is also presented. (author)

  14. Factors Associated with Delayed Cancer Diagnosis in Egyptian Children

    Directory of Open Access Journals (Sweden)

    E.R. Abdelkhalek

    2014-01-01

    Full Text Available Background Despite tremendous importance of early cancer diagnosis in children, few studies on this topic have been conducted in Egypt. Early stage diagnosis can have a positive effect on prognoses and the quality of life of children with cancer. We investigated delays in the diagnosis of childhood cancers in Egypt and determined the factors associated with these delays. Methods This retrospective study included 172 children with cancer from two pediatric oncology units. The interval between symptoms onset and final diagnosis for each child was estimated and examined by univariate and multivariate analyses to determine correlations with the child's sex, age at diagnosis, type and site of malignancy, family residence, socioeconomic status, and parental educational level. Findings The median total diagnosis delay period was 47 days caused by patients and/or parents (8 days and diagnosis (28 days. Statistically significant patient factors associated with delayed diagnosis were age (<5 years, lower parental education, and socioeconomic status. Sex residence and family size were not significant. Malignancy type and tumor site significantly affected the time for diagnosis. The lowest median value was associated with germ cell tumors (GCTs and leukemia, and the highest value was in children with brain tumor. Missed diagnoses were initially recorded in 39.5% of the patients and were associated with patient and tumor factors. Interpretation Delayed diagnosis of childhood cancer is related to age, family, socioeconomic status and parental education, and cancer type and site. Efforts should be made to promote awareness, develop effective steps to eliminate possible contributing factors, and determine the best intervention method.

  15. Delays in the diagnosis and treatment of tuberculosis patients in Vietnam: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Khanh Vu T

    2007-06-01

    Full Text Available Abstract Background Treatment delay is an important indicator of access to tuberculosis diagnosis and treatment. Analyses of patient delay (i.e. time interval between onset of symptoms and first consultation of a health care provider and health care delay (i.e. time interval between first consultation and start of treatment can inform policies to improve access. This study assesses the patient, health care provider and total delay in diagnosis and treatment of new smear-positive pulmonary tuberculosis patients, and the risk factors for long delay, in Vietnam. Methods A cross-sectional survey of new patients treated by the National Tuberculosis Control Programme was conducted in 70 randomly selected districts in Vietnam. All consecutively registered patients in one quarter of 2002 were interviewed using a pre-coded structured questionnaire. Results Median (range delay was 4 weeks (1–48 for total, 3 (1–48 weeks for patient and 1 (0–25 week for health care delay. Patients with long total delay (≥ 12 weeks, 15% accounted for 49% of the cumulative number of delay-weeks. Independent risk factors (p 5 km distance from a health facility or in the northern area. For long health care delay (≥ 6 weeks this was urban setting, residence in the central area and initial visit to a communal health post, TB hospital or the private sector. Conclusion Analyses of patient and treatment delays can indicate target groups and areas for health education and strengthening of the referral system, in particular between the private sector and the NTP.

  16. Initiation devices, initiation systems including initiation devices and related methods

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Michael A.; Condit, Reston A.; Rasmussen, Nikki; Wallace, Ronald S.

    2018-04-10

    Initiation devices may include at least one substrate, an initiation element positioned on a first side of the at least one substrate, and a spark gap electrically coupled to the initiation element and positioned on a second side of the at least one substrate. Initiation devices may include a plurality of substrates where at least one substrate of the plurality of substrates is electrically connected to at least one adjacent substrate of the plurality of substrates with at least one via extending through the at least one substrate. Initiation systems may include such initiation devices. Methods of igniting energetic materials include passing a current through a spark gap formed on at least one substrate of the initiation device, passing the current through at least one via formed through the at least one substrate, and passing the current through an explosive bridge wire of the initiation device.

  17. Effects of intrinsic stochasticity on delayed reaction-diffusion patterning systems

    KAUST Repository

    Woolley, Thomas E.; Baker, Ruth E.; Gaffney, Eamonn A.; Maini, Philip K.; Seirin-Lee, Sungrim

    2012-01-01

    Cellular gene expression is a complex process involving many steps, including the transcription of DNA and translation of mRNA; hence the synthesis of proteins requires a considerable amount of time, from ten minutes to several hours. Since diffusion-driven instability has been observed to be sensitive to perturbations in kinetic delays, the application of Turing patterning mechanisms to the problem of producing spatially heterogeneous differential gene expression has been questioned. In deterministic systems a small delay in the reactions can cause a large increase in the time it takes a system to pattern. Recently, it has been observed that in undelayed systems intrinsic stochasticity can cause pattern initiation to occur earlier than in the analogous deterministic simulations. Here we are interested in adding both stochasticity and delays to Turing systems in order to assess whether stochasticity can reduce the patterning time scale in delayed Turing systems. As analytical insights to this problem are difficult to attain and often limited in their use, we focus on stochastically simulating delayed systems. We consider four different Turing systems and two different forms of delay. Our results are mixed and lead to the conclusion that, although the sensitivity to delays in the Turing mechanism is not completely removed by the addition of intrinsic noise, the effects of the delays are clearly ameliorated in certain specific cases. © 2012 American Physical Society.

  18. Effects of intrinsic stochasticity on delayed reaction-diffusion patterning systems

    KAUST Repository

    Woolley, Thomas E.

    2012-05-22

    Cellular gene expression is a complex process involving many steps, including the transcription of DNA and translation of mRNA; hence the synthesis of proteins requires a considerable amount of time, from ten minutes to several hours. Since diffusion-driven instability has been observed to be sensitive to perturbations in kinetic delays, the application of Turing patterning mechanisms to the problem of producing spatially heterogeneous differential gene expression has been questioned. In deterministic systems a small delay in the reactions can cause a large increase in the time it takes a system to pattern. Recently, it has been observed that in undelayed systems intrinsic stochasticity can cause pattern initiation to occur earlier than in the analogous deterministic simulations. Here we are interested in adding both stochasticity and delays to Turing systems in order to assess whether stochasticity can reduce the patterning time scale in delayed Turing systems. As analytical insights to this problem are difficult to attain and often limited in their use, we focus on stochastically simulating delayed systems. We consider four different Turing systems and two different forms of delay. Our results are mixed and lead to the conclusion that, although the sensitivity to delays in the Turing mechanism is not completely removed by the addition of intrinsic noise, the effects of the delays are clearly ameliorated in certain specific cases. © 2012 American Physical Society.

  19. Reconfiguration of the NRAD delay loop for proposed 1 MW operations

    International Nuclear Information System (INIS)

    Heidel, C.C.; Richards, W.J.; Pruett, D.P.

    1984-01-01

    Neutron radiography is provided by the NRAD reactor facility, which is located beneath the HFEF hot cell. The NRAD reactor is a TRIGA reactor and is operated at a steady-state power level of 250 kw solely for neutron radiography and the development of radiography techniques. When the NRAD facility was designed and constructed, an operating power level of 250 kw was considered to be adequate for obtaining radiographs of the type of specimens envisaged at that time. Since that time a second radiography station was installed and the thickness of the specimens being radiographed is greater than was initially envisaged. In order to decrease exposure times, the reactor power level is to be increased to 1 Mw. The present delay loop can not to be used at 1 Mw operation, because the passage way where the primary piping exits the reactor room must be maintained less than 1 MR/hr. To obtain the needed delay before the primary water exits the reactor room using the present internal delay loop system would require two more delay loops of the same size to be placed in series with the present delay loop. Because the NRAD reactor tank is small this is not possible; therefore, the delay must take place external to the reactor tank. The delay loop will have to be located in a shielded area to allow the decay of N 16 . The best location for the delay tank will be in the east radiography

  20. Delayed habituation in Behcet's disease.

    Science.gov (United States)

    Gulturk, Sefa; Akyol, Melih; Kececi, Hulusi; Ozcelik, Sedat; Cinar, Ziynet; Demirkazik, Ayse

    2008-01-01

    The autonomic nervous system in Behcet's patients may be affected due to various reasons. This entity may be detected with the measurement of the electrodermal activities, heart rate variability and pupillometric methods. Habituation is one of the implicit forms of learning and memory and the loss of habituation can reveal pathological changes in the synaptic regions. To determine whether there is a functional decrease in the synaptic effectiveness (habituation) of the pathways to sympathetic neurons that had been repeatedly activated in Behcet's. Twelve patients with Behcet's disease and 12 healthy controls were included in the study. Sympathetic skin potential (SSP) records were taken at normal room temperature in a quiet place within a Faraday cage. Sixteen square wave single shock impulses (duration: 1200 ms, strength: 5 mA) were applied on each case. After the 1st stimulus, the SSP amplitudes were lower in the patients compared to the controls (P0.05). Whereas there was no significant differences among the SSP amplitudes after the 9th impulse in the controls (P>0.05). The habituation rate of the SSP after consecutive impulses was slowest in the patients compared to controls (P<0.001, t value=12.39). There is a delayed habituation in Behcet's disease and that may due to pathologic changes with vasculitis through their peripheral nerves.

  1. Examining the psychosocial determinants of women's decisions to delay childbearing.

    Science.gov (United States)

    Kearney, Allison L; White, Katherine M

    2016-08-01

    What are the psychosocial determinants of women's intentions to delay childbearing until after 35 years? Attitudes, pressure from important others, perceived self-confidence and anticipated regret all influence the decision-making process of women aged 18-30 years to defer their attempts to conceive their first child until 35+ years. Research has consistently demonstrated that, for many women, the decision to delay childbearing can lead to 'unintentional childlessness' due to a failure to consider the impact of age-related fertility decline. A large body of literature has also found strong links between age-related involuntary infertility and negative psychological impacts, including an increased prevalence of anxiety, depression, guilt, stigma and poor mental health. The study initially conducted focus groups designed to ascertain important beliefs informing participants' intentions to delay childbearing. A subsequent larger-scale quantitative questionnaire followed. Participants (n = 358) were female, aged between 18 and 30 years, lived in Australia, identified as being open to the idea of having children, were heterosexual, had not already had children, were not already pregnant, and had not received a diagnosis of medical infertility prior to participating. Hierarchical multiple regression analyses showed strong support for psychosocial predictors of attitude, pressure from others and perceived self-confidence as predictors of women's intentions to delay childbearing, accounting for 59% of total variance. The extended model that included anticipated regret, accounted for a significant additional 4.4% variance in intention to delay childbearing past the age of 35 years. Proportionally more participants were younger, Caucasian, and were university students, thus limiting the generalizability of results to the wider Australian community. Future research in this domain is recommended to adopt a prospective design and incorporate a measure of behaviour to

  2. Delayed hepatobiliary imaging in the diagnosis of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Chen, S.; Ma, Z.; Tang, Z.

    2000-01-01

    In recent years, the use of ultrasonography (US), X-CT and MRI has reduced the employment of isotopic explorations in the detection of hepatocellular carcinoma (HCC). But sometime the results of US, X-CT or MRI were different and diagnosis was very difficult. This present investigation was aimed to assess the usefulness of delayed hepatobiliary imaging in the diagnosis of HCC in these patients. Forty-eight patients consisting of 33 males and 15 females were entered into the research protocol. The mean age was 46 yr old (range 12-71 yr old). All of the patients were performed by surgery and verified histologically after nuclear examination. The subject was in a supine position under a gamma camera (Elscint, Apex Ap-6) and 555 MBq of Tc-99m-PMT were injected intravenously. The initial scinphotos obtained within 1 min after injection were used to image the blood pool phase. Subsequently, hepatic scans were obtained at 5 min, 1,2 and 5 hr. Anterior, right lateral and posterior hepatic images were recorded. According to the radioactive uptake by the lesion in delayed phase, the negative (no or minor uptake), positive (equal or greater uptake) or very strong positive (almost equal to the activity, of gallbladder) were judged. The positive were considered as diagnostic of HCC. And the very strong positive, were considered as diagnostic of benign hepatoma, such as adenoma or FNH. Thirty-seven of the forty-eight patients were HCC based on histology. Delayed imaging revealed increased or equilibrated uptake of radioactivity by the tumors in 22 of 37 patients with hepatocellular carcinoma. The sensitivity was 59.5%. One patient final diagnosis based on histology was focal nodular regenerative hyperplasia, and only the diagnosis with delayed hepatobiliary imaging before surgery was correct. Compared with US, X-CT and MRI, delayed hepatobiliary imaging had the highest specificity for diagnosis of hepatocellular carcinoma. In recent group, the specificity of Tc-99m-PMT delayed

  3. Time delays, population, and economic development

    Science.gov (United States)

    Gori, Luca; Guerrini, Luca; Sodini, Mauro

    2018-05-01

    This research develops an augmented Solow model with population dynamics and time delays. The model produces either a single stationary state or multiple stationary states (able to characterise different development regimes). The existence of time delays may cause persistent fluctuations in both economic and demographic variables. In addition, the work identifies in a simple way the reasons why economics affects demographics and vice versa.

  4. On Delay and Security in Network Coding

    Science.gov (United States)

    Dikaliotis, Theodoros K.

    2013-01-01

    In this thesis, delay and security issues in network coding are considered. First, we study the delay incurred in the transmission of a fixed number of packets through acyclic networks comprised of erasure links. The two transmission schemes studied are routing with hop-by-hop retransmissions, where every node in the network simply stores and…

  5. Delaying Developmental Mathematics: The Characteristics and Costs

    Science.gov (United States)

    Johnson, Marianne; Kuennen, Eric

    2004-01-01

    This paper investigates which students delay taking a required developmental mathematics course and the impact of delay on student performance in introductory microeconomics. Analysis of a sample of 1462 students at a large Midwestern university revealed that, although developmental-level mathematics students did not reach the same level of…

  6. ANALYSING SURFACE MOVEMENT DELAYS IN AN AIRPORT

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2014-07-01

    Full Text Available Queuing effect can be in the different components of ground operations. Causes of surface – movement delays are long taxi – in and taxi – out operations during departure and arrival of aircraft. Surface movement delays in an airport are analyzed

  7. Analyzing delay causes in Egyptian construction projects

    Directory of Open Access Journals (Sweden)

    Mohamed M. Marzouk

    2014-01-01

    Full Text Available Construction delays are common problems in civil engineering projects in Egypt. These problems occur frequently during project life-time leading to disputes and litigation. Therefore, it is essential to study and analyze causes of construction delays. This research presents a list of construction delay causes retrieved from literature. The feedback of construction experts was obtained through interviews. Subsequently, a questionnaire survey was prepared. The questionnaire survey was distributed to thirty-three construction experts who represent owners, consultants, and contractor’s organizations. Frequency Index, Severity Index, and Importance Index are calculated and according to the highest values of them the top ten delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the research. Statistical analysis is carried out using analysis of variance ANOVA method to test delay causes, obtained from the survey. The test results reveal good correlation between groups while there is significant difference between them for some delay causes and finally roadmap for prioritizing delay causes groups is presented.

  8. Algebraic entropy for differential-delay equations

    OpenAIRE

    Viallet, Claude M.

    2014-01-01

    We extend the definition of algebraic entropy to a class of differential-delay equations. The vanishing of the entropy, as a structural property of an equation, signals its integrability. We suggest a simple way to produce differential-delay equations with vanishing entropy from known integrable differential-difference equations.

  9. A Polynomial Estimate of Railway Line Delay

    DEFF Research Database (Denmark)

    Cerreto, Fabrizio; Harrod, Steven; Nielsen, Otto Anker

    2017-01-01

    Railway service may be measured by the aggregate delay over a time horizon or due to an event. Timetables for railway service may dampen aggregate delay by addition of additional process time, either supplement time or buffer time. The evaluation of these variables has previously been performed...

  10. Test Anxiety and Academic Delay of Gratification

    Science.gov (United States)

    Bembenutty, Hefer

    2009-01-01

    The present study examined the relationship between college students' willingness to delay gratification, motivation, self-regulation of learning, and their level of test anxiety (N = 364). Academic delay of gratification refers to students' postponement of immediately available opportunities to satisfy impulses in favor of pursuing academic…

  11. Delaying gratification depends on social trust

    Science.gov (United States)

    Michaelson, Laura; de la Vega, Alejandro; Chatham, Christopher H.; Munakata, Yuko

    2013-01-01

    Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then choose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity. PMID:23801977

  12. Delaying gratification depends on social trust

    Directory of Open Access Journals (Sweden)

    Laura eMichaelson

    2013-06-01

    Full Text Available Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then chose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity.

  13. Beta delayed particle emission in light nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Gabelmann, H.

    1991-01-01

    A short discussion of theoretical treatments of beta delayed particle emission is followed by a presentation of data on the newly found beta delayed deuteron decay of 6 He. This decay cannot be described properly with existing theories. (author) 8 refs.; 3 figs

  14. Allee effects on population dynamics with delay

    International Nuclear Information System (INIS)

    Celik, C.; Merdan, H.; Duman, O.; Akin, O.

    2008-01-01

    In this paper, we study the stability analysis of equilibrium points of population dynamics with delay when the Allee effect occurs at low population density. Mainly, our mathematical results and numerical simulations point to the stabilizing effect of the Allee effects on population dynamics with delay

  15. Nonlinear delay monopoly with bounded rationality

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2012-01-01

    The purpose of this paper is to study the dynamics of a monopolistic firm in a continuous-time framework. The firm is assumed to be boundedly rational and to experience time delays in obtaining and implementing information on output. The dynamic adjustment process is based on the gradient of the expected profit. The paper is divided into three parts: we examine delay effects on dynamics caused by one-time delay and two-time delays in the first two parts. Global dynamics and analytical results on local dynamics are numerically confirmed in the third part. Four main results are demonstrated. First, the stability switch from stability to instability occurs only once in the case of a single delay. Second, the alternation of stability and instability can continue if two time delays are involved. Third, the occurence of Hopf bifurcation is analytically shown if stability is lost. Finally, in a bifurcation process, there are a period-doubling cascade to chaos and a period-halving cascade to the equilibrium point in the case of two time delays if the difference between the two delays is large.

  16. Decrease in the ability to detect elevated lung thallium due to delay in commencing imaging after exercise

    International Nuclear Information System (INIS)

    Rothendler, J.A.; Boucher, C.A.; Strauss, H.W.; Pohost, G.M.; Okada, R.D.

    1985-01-01

    Post-exercise elevation of the lung/myocardial thallium ratio and a high lung clearance rate between initial and delayed images have been reported to be markers for exercise-induced left ventricular (LV) dysfunction associated with coronary artery disease (CAD). The authors performed thallium exercise tests on 60 patients, 42 with CAD, in order to determine the effect of delaying initial imaging on detection of elevated lung thallium. In addition to images obtained at 2 minutes and at 2 hours after exercise, 18-minute images were also obtained to simulate such a delay. Because of rapid isotope clearance in those with initially elevated lung activity, there was decreased sensitivity of both the initial lung/myocardial ratio and lung thallium clearance for detecting CAD, using the 18-minute image as the initial post exercise study. They conclude that initial imaging should be done in the anterior view early after exercise to optimize detection of elevated lung thallium

  17. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design .... To find the quality of non-robust tests, a fuzzy delay ..... Dubois D and Prade H 1989 Processing Fuzzy temporal knowledge. IEEE Transactions ...

  18. Delay-dependent exponential stability of cellular neural networks with time-varying delays

    International Nuclear Information System (INIS)

    Zhang Qiang; Wei Xiaopeng; Xu Jin

    2005-01-01

    The global exponential stability of cellular neural networks (CNNs) with time-varying delays is analyzed. Two new sufficient conditions ensuring global exponential stability for delayed CNNs are obtained. The conditions presented here are related to the size of delay. The stability results improve the earlier publications. Two examples are given to demonstrate the effectiveness of the obtained results

  19. Synchronization of delayed systems in the presence of delay time modulation

    International Nuclear Information System (INIS)

    Kye, Won-Ho; Choi, Muhan; Kim, Myung-Woon; Lee, Soo-Young; Rim, Sunghwan; Kim, Chil-Min; Park, Young-Jai

    2004-01-01

    We investigate synchronization in the presence of delay time modulation for application to communication. We have observed that the robust synchronization is established by a common delay signal and its threshold is presented using Lyapunov exponents analysis. The influence of the delay time modulation in chaotic oscillators is also discussed

  20. Initial Cladding Condition

    International Nuclear Information System (INIS)

    Siegmann, E.

    2000-01-01

    The purpose of this analysis is to describe the condition of commercial Zircaloy clad fuel as it is received at the Yucca Mountain Project (YMP) site. Most commercial nuclear fuel is encased in Zircaloy cladding. This analysis is developed to describe cladding degradation from the expected failure modes. This includes reactor operation impacts including incipient failures, potential degradation after reactor operation during spent fuel storage in pool and dry storage and impacts due to transportation. Degradation modes include cladding creep, and delayed hydride cracking during dry storage and transportation. Mechanical stresses from fuel handling and transportation vibrations are also included. This Analysis and Model Report (AMR) does not address any potential damage to assemblies that might occur at the YMP surface facilities. Ranges and uncertainties have been defined. This analysis will be the initial boundary condition for the analysis of cladding degradation inside the repository. In accordance with AP-2.13Q, ''Technical Product Development Planning'', a work plan (CRWMS M andO 2000c) was developed, issued, and utilized in the preparation of this document. There are constraints, caveats and limitations to this analysis. This cladding degradation analysis is based on commercial Pressurized Water Reactor (PWR) fuel with Zircaloy cladding but is applicable to Boiling Water Reactor (BWR) fuel. Reactor operating experience for both PWRs and BWRs is used to establish fuel reliability from reactor operation. It is limited to fuel exposed to normal operation and anticipated operational occurrences (i.e. events which are anticipated to occur within a reactor lifetime), and not to fuel that has been exposed to severe accidents. Fuel burnup projections have been limited to the current commercial reactor licensing environment with restrictions on fuel enrichment, oxide coating thickness and rod plenum pressures. The information provided in this analysis will be used in

  1. Nuclear materials facility safety initiative

    International Nuclear Information System (INIS)

    Peddicord, K.L.; Nelson, P.; Roundhill, M.; Jardine, L.J.; Lazarev, L.; Moshkov, M.; Khromov, V.V.; Kruchkov, E.; Bolyatko, V.; Kazanskij, Yu.; Vorobeva, I.; Lash, T.R.; Newton, D.; Harris, B.

    2000-01-01

    Safety in any facility in the nuclear fuel cycle is a fundamental goal. However, it is recognized that, for example, should an accident occur in either the U.S. or Russia, the results could seriously delay joint activities to store and disposition weapons fissile materials in both countries. To address this, plans are underway jointly to develop a nuclear materials facility safety initiative. The focus of the initiative would be to share expertise which would lead in improvements in safety and safe practices in the nuclear fuel cycle.The program has two components. The first is a lab-to-lab initiative. The second involves university-to-university collaboration.The lab-to-lab and university-to-university programs will contribute to increased safety in facilities dealing with nuclear materials and related processes. These programs will support important bilateral initiatives, develop the next generation of scientists and engineers which will deal with these challenges, and foster the development of a safety culture

  2. Gravitational Lens Time Delays Using Polarization Monitoring

    Directory of Open Access Journals (Sweden)

    Andrew Biggs

    2017-11-01

    Full Text Available Gravitational lens time delays provide a means of measuring the expansion of the Universe at high redshift (and therefore in the ‘Hubble flow’ that is independent of local calibrations. It was hoped that many of the radio lenses found in the JVAS/CLASS survey would yield time delays as these were selected to have flat spectra and are dominated by multiple compact components. However, despite extensive monitoring with the Very Large Array (VLA, time delays have only been measured for three of these systems (out of 22. We have begun a programme to reanalyse the existing VLA monitoring data with the goal of producing light curves in polarized flux and polarization position angle, either to improve delay measurements or to find delays for new sources. Here, we present preliminary results on the lens system B1600+434 which demonstrate the presence of correlated and substantial polarization variability in each image.

  3. Controllability of nonlinear delay oscillating systems

    Directory of Open Access Journals (Sweden)

    Chengbin Liang

    2017-05-01

    Full Text Available In this paper, we study the controllability of a system governed by second order delay differential equations. We introduce a delay Gramian matrix involving the delayed matrix sine, which is used to establish sufficient and necessary conditions of controllability for the linear problem. In addition, we also construct a specific control function for controllability. For the nonlinear problem, we construct a control function and transfer the controllability problem to a fixed point problem for a suitable operator. We give a sufficient condition to guarantee the nonlinear delay system is controllable. Two examples are given to illustrate our theoretical results by calculating a specific control function and inverse of a delay Gramian matrix.

  4. Dynamics of microbubble oscillators with delay coupling

    Science.gov (United States)

    Heckman, C. R.; Sah, S. M.; Rand, R. H.

    2010-10-01

    We investigate the stability of the in-phase mode in a system of two delay-coupled bubble oscillators. The bubble oscillator model is based on a 1956 paper by Keller and Kolodner. Delay coupling is due to the time it takes for a signal to travel from one bubble to another through the liquid medium that surrounds them. Using techniques from the theory of differential-delay equations as well as perturbation theory, we show that the equilibrium of the in-phase mode can be made unstable if the delay is long enough and if the coupling strength is large enough, resulting in a Hopf bifurcation. We then employ Lindstedt's method to compute the amplitude of the limit cycle as a function of the time delay. This work is motivated by medical applications involving noninvasive localized drug delivery via microbubbles.

  5. Treatment seeking behaviour and prevalence of treatment delay among malaria patients along Thailand-Myanmar border in Tak province

    Directory of Open Access Journals (Sweden)

    Krit Sonkong

    2015-04-01

    Full Text Available Objective: To investigate treatment seeking behaviour and the prevalence of treatment delay of malaria patients. Methods: A cross-sectional study was conducted with malaria patients along the ThailandMyanmar border in Tak province, Thailand. Results: Most of patients (70.0% were treated for fever before receiving treatment at a malaria clinic or public hospital. The sources of initial treatments were self-treatment (64.0%, malaria clinics (20.0%, public hospital (11.0%, sub-district health promotion hospital (3.3%, and malaria posts (1.1%. Prevalence of patients delayed more than one day after onset of symptoms was 79.4%, but doctor delay of more than one day occurred in only 1.3%. The prevalence of treatment delay (total delay of more than one day was 79.6%. Patient delay and treatment delay were found to be significantly higher among hill tribe than Thai subjects (P=0.004 and 0.003, respectively but, there was no significant association between ethnicity and doctor delay (P=0.669. Conclusion: Patient delay in seeking treatment is a major problem along the ThailandMyanmar border in Tak province, especially in hill tribe people. Self-treatment accounted for most of initial treatment sought by patients.

  6. Delayed cell death, giant cell formation and chromosome instability induced by X-irradiation in human embryo cells

    International Nuclear Information System (INIS)

    Roy, K.; Kodama, Seiji; Suzuki, Keiji; Watanabe, Masami

    1999-01-01

    We studied X-ray-induced delayed cell death, delayed giant cell formation and delayed chromosome aberrations in normal human embryo cells to explore the relationship between initial radiation damage and delayed effect appeared at 14 to 55 population doubling numbers (PDNs) after X-irradiation. The delayed effect was induced in the progeny of X-ray survivors in a dose-dependent manner and recovered with increasing PDNs after X-irradiation. Delayed plating for 24 h post-irradiation reduced both acute and delayed lethal damage, suggesting that potentially lethal damage repair (PLDR) can be effective for relieving the delayed cell death. The chromosome analysis revealed that most of the dicentrics (more than 90%) observed in the progeny of X-ray survivors were not accompanied with fragments, in contrast with those observed in the first mitosis after X-irradiation. The present results indicate that the potentiality of genetic instability is determined during the repair process of initial radiation damage and suggest that the mechanism for formation of delayed chromosome aberrations by radiation might be different from that of direct radiation-induced chromosome aberrations. (author)

  7. Microscopic Control Delay Modeling at Signalized Arterials Using Bluetooth Technology

    OpenAIRE

    Rajasekhar, Lakshmi

    2011-01-01

    Real-time control delay estimation is an important performance measure for any intersection to improve the signal timing plans dynamically in real-time and hence improve the overall system performance. Control delay estimates helps to determine the level-of-service (LOS) characteristics of various approaches at an intersection and takes into account deceleration delay, stopped delay and acceleration delay. All kinds of traffic delay calculation especially control delay calculation has always ...

  8. On the cost/delay tradeoff of wireless delay tolerant geographic routing

    OpenAIRE

    Tasiopoulos, Argyrios; Tsiaras, Christos; Toumpis, Stavros

    2012-01-01

    In Delay Tolerant Networks (DTNs), there is a fundamental tradeoff between the aggregate transport cost of a packet and the delay in its delivery. We study this tradeoff in the context of geographical routing in wireless DTNs.We ?rst specify the optimal cost/delay tradeoff, i.e., the tradeoff under optimal network operation, using a dynamic network construction termed the Cost/Delay Evolving Graph (C/DEG) and the Optimal Cost/Delay Curve (OC/DC), a function that gives the minimum possible agg...

  9. Mechanical design of a free-wheel clutch for the thermal engine of a parallel hybrid vehicle with thermal and electrical power-train; Conception mecanique d'un accouplement a roue libre pour le moteur thermique d'un vehicule hybride parallele thermique et electrique

    Energy Technology Data Exchange (ETDEWEB)

    Santin, J.J.

    2001-07-01

    This thesis deals with the design of a free-wheel clutch. This unit is intended to replace the automated dry single-plate clutch of a parallel hybrid car with thermal and electric power-train. Furthermore, the car is a single shaft zero emission vehicle fitted with a controlled gearbox. Chapter one focuses on the type of hybrid vehicle studied. It shows the need to isolate the engine from the rest of the drive train, depending on the driving conditions. Chapter two presents and compares the two alternatives: automated clutch and free-wheel. In order to develop the free-wheel option, the torsional vibrations in the automotive drive line had to be closely studied. It required the design of a specific modular tool, as presented in chapter three, with the help of MATLAB SIMULINK. Lastly, chapter four shows how this tool was used during the design stage and specifies the way to build it. The free-wheel is then to be fitted to a prototype hybrid vehicle, constructed by both the LAMIH and PSA. (author)

  10. Unexpected Coexisting Myocardial Infarction Detected by Delayed Enhancement MRI

    Directory of Open Access Journals (Sweden)

    Edouard Gerbaud

    2009-01-01

    Full Text Available We report a case of an unexpected coexisting anterior myocardial infarction detected by delayed enhancement MRI in a 41-year-old man following a presentation with a first episode of chest pain during inferior acute myocardial infarction. This second necrotic area was not initially suspected because there were no ECG changes in the anterior leads and the left descending coronary artery did not present any significant stenoses on emergency coronary angiography. Unrecognised myocardial infarction may carry important prognostic implications. CMR is currently the best imaging technique to detect unexpected infarcts.

  11. Prevention of delayed hydride cracking in zirconium alloys

    International Nuclear Information System (INIS)

    Cheadle, B.A.; Coleman, C.E.; Ambler, J.F.R.

    1987-01-01

    Zirconium alloys are susceptible to a mechanism for crack initiation and propagation called delayed hydride cracking. From a review of component failures and experimental results, we have developed the requirements for preventing this cracking. The important parameters for cracking are hydrogen concentration, flaws, and stress; each should be minimized. At the design and construction stages hydrogen pickup has to be controlled, quality assurance needs to be at a high enough level to ensure the absence of flaws, and residual stresses must be eliminated by careful fabrication and heat treatment

  12. Explicit Finite Difference Methods for the Delay Pseudoparabolic Equations

    Directory of Open Access Journals (Sweden)

    I. Amirali

    2014-01-01

    Full Text Available Finite difference technique is applied to numerical solution of the initial-boundary value problem for the semilinear delay Sobolev or pseudoparabolic equation. By the method of integral identities two-level difference scheme is constructed. For the time integration the implicit rule is being used. Based on the method of energy estimates the fully discrete scheme is shown to be absolutely stable and convergent of order two in space and of order one in time. The error estimates are obtained in the discrete norm. Some numerical results confirming the expected behavior of the method are shown.

  13. A fly-wheel drive with controlled-torque clutch for a reactors cooling circuit pumps; Entrainement des pompes du circuit de refrigeration d'un reacteur par volant a embrayage sous couple controle

    Energy Technology Data Exchange (ETDEWEB)

    Riettini, A [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-10-15

    After a theoretical study on the slowing down of a centrifugal pump, the motion equations have been checked by means of experimental tests. In order to have important slowing down times (which is the case of the cooling pumps of a research reactor) it is necessary to add a fly-wheel. To prevent troubles when starting, a block pump-fly-wheel with clutch under controlled torque was developed. It is so possible to start the fly-wheel progressively without increasing too much power of the driving motor. (author) [French] Apres une etude theorique sur le mouvement de ralentissement d'une pompe centrifuge, les equations du mouvement ont ete verifiees par des essais pratiques. Pour obtenir des temps de ralentissement importants (cas des pompes de refrigeration d'un reacteur de recherche) il est necessaire d'y adjoindre un volant d'inertie. Pour eviter les inconvenients au demarrage, on a etudie un ensemble pompe-volant avec embrayage sous couple controle. Cette solution permet de lancer progressivement le volant sans augmentation appreciable de la puissance du moteur d'entrainement. (auteur)

  14. Reward acts as a signal to control delay-period activity in delayed-response tasks.

    Science.gov (United States)

    Ichihara-Takeda, Satoe; Takeda, Kazuyoshi; Funahashi, Shintaro

    2010-03-31

    Prefrontal delay-period activity represents a neural mechanism for the active maintenance of information and needs to be controlled by some signal to appropriately operate working memory. To examine whether reward-delivery acts as this signal, the effects of delay-period activity in response to unexpected reward-delivery were examined by analyzing single-neuron activity recorded in the primate dorsolateral prefrontal cortex. Among neurons that showed delay-period activity, 34% showed inhibition of this activity in response to unexpected reward-delivery. The delay-period activity of these neurons was affected by the expectation of reward-delivery. The strength of the reward signal in controlling the delay-period activity is related to the strength of the effect of reward information on the delay-period activity. These results indicate that reward-delivery acts as a signal to control delay-period activity.

  15. Chaos synchronization in time-delayed systems with parameter mismatches and variable delay times

    International Nuclear Information System (INIS)

    Shahverdiev, E.M.; Nuriev, R.A.; Hashimov, R.H.; Shore, K.A.

    2004-06-01

    We investigate synchronization between two undirectionally linearly coupled chaotic nonidentical time-delayed systems and show that parameter mismatches are of crucial importance to achieve synchronization. We establish that independent of the relation between the delay time in the coupled systems and the coupling delay time, only retarded synchronization with the coupling delay time is obtained. We show that with parameter mismatch or without it neither complete nor anticipating synchronization occurs. We derive existence and stability conditions for the retarded synchronization manifold. We demonstrate our approach using examples of the Ikeda and Mackey Glass models. Also for the first time we investigate chaos synchronization in time-delayed systems with variable delay time and find both existence and sufficient stability conditions for the retarded synchronization manifold with the coupling-delay lag time. (author)

  16. Delays in Building Construction Projects in Ghana

    Directory of Open Access Journals (Sweden)

    Adwoa B Agyakwah-Baah

    2010-07-01

    Full Text Available This study investigates the causes of delay of building construction projects in Ghana to determine the most important according to the key project participants; clients, consultants, and contractors. Thirty-two possible causes of delay were identified from the literature and semi-structured interviews of 15 key players in the implementation process. These delay factors were further categorised into nine major groups. The list of delay causes was subjected to a questionnaire survey for the identification of the most important causes of delay. The field survey included 130 respondents made up of 39 contractors, 37 clients and 54 consultants. The relative importance of the individual causes and the groups were calculated and ranked by their relative importance index. The overall results of the study indicate that the respondents generally agree that financial group factors ranked highest among the major factors causing delay in construction projects in Ghana. The financial group factors were delay in honouring payment certificates, difficulty in accessing credit and fluctuation in prices. Materials group factors are second followed by scheduling and controlling factors.

  17. Behavioral effects of delayed timeouts from reinforcement.

    Science.gov (United States)

    Byrne, Tom; Poling, Alan

    2017-03-01

    Timeouts are sometimes used in applied settings to reduce target responses, and in some circumstances delays are unavoidably imposed between the onset of a timeout and the offset of the response that produces it. The present study examined the effects of signaled and unsignaled timeouts in rats exposed to concurrent fixed-ratio 1 fixed-ratio 1 schedules of food delivery, where each response on one lever, the location of which changed across conditions, produced both food and a delayed 10-s timeout. Delays of 0 to 38 s were examined. Delayed timeouts often, but not always, substantially reduced the number of responses emitted on the lever that produced timeouts relative to the number emitted on the lever that did not produce timeouts. In general, greater sensitivity was observed to delayed timeouts when they were signaled. These results demonstrate that delayed timeouts, like other delayed consequences, can affect behavior, albeit less strongly than immediate consequences. © 2017 Society for the Experimental Analysis of Behavior.

  18. Effects of drugs of abuse and cholinergic agents on delayed matching-to-sample responding in the squirrel monkey.

    Science.gov (United States)

    Hudzik, T J; Wenger, G R

    1993-04-01

    To study how drugs may disrupt short-term memory function, squirrel monkeys were trained to respond under a titrating delayed matching-to-sample schedule of reinforcement. Monkeys could respond on each of three keys in an operant chamber. At the start of each trial, the 30th response on the center key illuminated each of the side keys, one of which matched the stimulus presented on the center key (simultaneous matching). A response to the correct (matching) side key turned off all stimuli and initiated a delay, the length of which varied as a function of ongoing performance. After the delay, stimuli were randomly presented on two of the three keys. A response to the key which matched the color on the center key before the delay resulted in delivery of a food pellet (delayed matching). Incorrect simultaneous or delayed matching responses initiated a timeout. Under this procedure, diazepam and scopolamine decreased delayed matching accuracy at one or more doses that did not significantly decrease mean delay values, but only scopolamine decreased matching accuracy at a dose that did not significantly decrease response rates. Cocaine decreased mean delay values after the highest dose without affecting matching accuracy. Pentobarbital and methylscopolamine decreased matching accuracy and mean and maximum delay values after the highest doses. Nicotine and phencyclidine produced small decreases in delayed matching accuracy without affecting mean and maximum delay values. Caffeine, morphine, physostigmine and neostigmine did not alter matching performance even after doses that markedly decreased rates of responding.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Models of the delayed nonlinear Raman response in diatomic gases

    International Nuclear Information System (INIS)

    Palastro, J. P.; Antonsen, T. M. Jr.; Pearson, A.

    2011-01-01

    We examine the delayed response of a diatomic gas to a polarizing laser field with the goal of obtaining computationally efficient methods for use with laser pulse propagation simulations. We demonstrate that for broadband pulses, heavy molecules such as O 2 and N 2 , and typical atmospheric temperatures, the initial delayed response requires only classical physics. The linear kinetic Green's function is derived from the Boltzmann equation and shown to be in excellent agreement with full density-matrix calculations. A straightforward perturbation approach for the fully nonlinear, kinetic impulse response is also presented. With the kinetic theory a reduced fluid model of the diatomic gas' orientation is derived. Transport coefficients are introduced to model the kinetic phase mixing of the delayed response. In addition to computational rapidity, the fluid model provides intuition through the use of familiar macroscopic quantities. Both the kinetic and the fluid descriptions predict a nonlinear steady-state alignment after passage of the laser pulse, which in the fluid model is interpreted as an anisotropic temperature of the diatomic fluid with respect to motion about the polarization axis.

  20. Why do total-body decay curves of iodine-labeled proteins begin with a delay

    International Nuclear Information System (INIS)

    Regoeczi, E.

    1987-01-01

    The initial delay that occurs in total-body radiation curves reaching their single-exponential slopes was analyzed from 106 experiments involving several mammalian species (guinea pig, mouse, rabbit, and rat) and plasma proteins (alpha 1-acid glycoprotein, antithrombin III, fibrinogen, immunoglobulin G, and transferrin) in 14 different combinations. The time interval (Td) between injection and the intercept of the slope with the full-dose value was adopted as a measure of curve nonideality. The overall mean Td was 6.6 h, but individual values showed a significant correlation to protein half-lives, whereby proteins of unequal metabolic properties exhibited different mean Td values. Targeting protein to the liver abolished delay. Choice of the isotope ( 125 I or 131 I) and size of the labeled protein had no influence on the magnitude of delay. Whole-body radiation curves of animals that received [ 125 I]iodotyrosines, Na 131 I, or 131 I-polyvinylpyrrolidone exhibited no initial delays. These results do not support the earlier notion that delay is caused by a redistribution of the labeled protein in the body to radiometrically more favorable sites. However, they are compatible with the assumption that delayed passage of a protein dose through the extracellular matrix and/or retarded transfer of proteolytic products from extravascular catabolic sites to plasma may be responsible for the phenomenon

  1. Transmission delays in hardware clock synchronization

    Science.gov (United States)

    Shin, Kang G.; Ramanathan, P.

    1988-01-01

    Various methods, both with software and hardware, have been proposed to synchronize a set of physical clocks in a system. Software methods are very flexible and economical but suffer an excessive time overhead, whereas hardware methods require no time overhead but are unable to handle transmission delays in clock signals. The effects of nonzero transmission delays in synchronization have been studied extensively in the communication area in the absence of malicious or Byzantine faults. The authors show that it is easy to incorporate the ideas from the communication area into the existing hardware clock synchronization algorithms to take into account the presence of both malicious faults and nonzero transmission delays.

  2. A continuous time Cournot duopoly with delays

    International Nuclear Information System (INIS)

    Gori, Luca; Guerrini, Luca; Sodini, Mauro

    2015-01-01

    This paper extends the classical repeated duopoly model with quantity-setting firms of Bischi et al. (1998) by assuming that production of goods is subject to some gestation lags but exchanges take place continuously in the market. The model is expressed in the form of differential equations with discrete delays. By using some recent mathematical techniques and numerical experiments, results show some dynamic phenomena that cannot be observed when delays are absent. In addition, depending on the extent of time delays and inertia, synchronisation failure can arise even in the event of homogeneous firms.

  3. Bubbling in delay-coupled lasers.

    Science.gov (United States)

    Flunkert, V; D'Huys, O; Danckaert, J; Fischer, I; Schöll, E

    2009-06-01

    We theoretically study chaos synchronization of two lasers which are delay coupled via an active or a passive relay. While the lasers are synchronized, their dynamics is identical to a single laser with delayed feedback for a passive relay and identical to two delay-coupled lasers for an active relay. Depending on the coupling parameters the system exhibits bubbling, i.e., noise-induced desynchronization, or on-off intermittency. We associate the desynchronization dynamics in the coherence collapse and low-frequency fluctuation regimes with the transverse instability of some of the compound cavity's antimodes. Finally, we demonstrate how, by using an active relay, bubbling can be suppressed.

  4. Travelling wave solutions in delayed cooperative systems

    International Nuclear Information System (INIS)

    Li, Bingtuan; Zhang, Liang

    2011-01-01

    We establish the existence of travelling wave solutions for delayed cooperative recursions that are allowed to have more than two equilibria. We define an important extended real number that is used to determine the speeds of travelling wave solutions. The results can be applied to a large class of delayed cooperative reaction–diffusion models. We show that for a delayed Lotka–Volterra reaction–diffusion competition model, there exists a finite positive number c * + that can be characterized as the slowest speed of travelling wave solutions connecting two mono-culture equilibria or connecting a mono-culture with the coexistence equilibrium

  5. Transcriptional delay stabilizes bistable gene networks.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Ott, William; Josić, Krešimir; Bennett, Matthew R

    2013-08-02

    Transcriptional delay can significantly impact the dynamics of gene networks. Here we examine how such delay affects bistable systems. We investigate several stochastic models of bistable gene networks and find that increasing delay dramatically increases the mean residence times near stable states. To explain this, we introduce a non-Markovian, analytically tractable reduced model. The model shows that stabilization is the consequence of an increased number of failed transitions between stable states. Each of the bistable systems that we simulate behaves in this manner.

  6. Construction delays causing risks on time and cost - a critical review

    Directory of Open Access Journals (Sweden)

    Chidambaram Ramanathan

    2012-02-01

    Full Text Available There is an increase in the number of construction projects experiencing extensive delays leading to exceeding initial time and cost budget.  This paper reviews 41 studies around the world which surveyed the delay factors and classified them into Groups.  The main purpose of this paper is to review literature, each of which have categorized the causes that are responsible for time delays and cost overrun in projects. The collected list has 113 causes for delays categorized in to 18 different groups.  Most of the researches have analysed the responses from the Questionnaire survey.    The collected data are used to rank the problem.  The data are further used to investigate and analyse Important Index, Frequency Index, Severity Index, Relative Important Index, Relative Importance Weight, Weighted Average, Mean, Standard Deviation and Variance.  The collective comparison has revealed that the ranking given by all the researchers is not the same.  Further each and every study has different rank ratings for the different group of the delays.  This review paper attempts to provide an updated compilation of the earlier studies on ranking of the delay causers, which are never similar and constant for universal projects.  It is concluded that a separate study is required for identifying the factors causing delay for projects operated in Sabah, East Malaysia.

  7. Steady states and outbreaks of two-phase nonlinear age-structured model of population dynamics with discrete time delay.

    Science.gov (United States)

    Akimenko, Vitalii; Anguelov, Roumen

    2017-12-01

    In this paper we study the nonlinear age-structured model of a polycyclic two-phase population dynamics including delayed effect of population density growth on the mortality. Both phases are modelled as a system of initial boundary values problem for semi-linear transport equation with delay and initial problem for nonlinear delay ODE. The obtained system is studied both theoretically and numerically. Three different regimes of population dynamics for asymptotically stable states of autonomous systems are obtained in numerical experiments for the different initial values of population density. The quasi-periodical travelling wave solutions are studied numerically for the autonomous system with the different values of time delays and for the system with oscillating death rate and birth modulus. In both cases it is observed three types of travelling wave solutions: harmonic oscillations, pulse sequence and single pulse.

  8. Dynamics of a delay differential equation model of hepatitis B virus infection.

    Science.gov (United States)

    Gourley, Stephen A; Kuang, Yang; Nagy, John D

    2008-04-01

    We formulate and systematically study the global dynamics of a simple model of hepatitis B virus in terms of delay differential equations. This model has two important and novel features compared to the well-known basic virus model in the literature. Specifically, it makes use of the more realistic standard incidence function and explicitly incorporates a time delay in virus production. As a result, the infection reproduction number is no longer dependent on the patient liver size (number of initial healthy liver cells). For this model, the existence and the component values of the endemic steady state are explicitly dependent on the time delay. In certain biologically interesting limiting scenarios, a globally attractive endemic equilibrium can exist regardless of the time delay length.

  9. STRONG LENS TIME DELAY CHALLENGE. I. EXPERIMENTAL DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    Dobler, Gregory [Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, CA 93106 (United States); Fassnacht, Christopher D.; Rumbaugh, Nicholas [Department of Physics, University of California, 1 Shields Avenue, Davis, CA 95616 (United States); Treu, Tommaso; Liao, Kai [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Marshall, Phil [Kavli Institute for Particle Astrophysics and Cosmology, P.O. Box 20450, MS29, Stanford, CA 94309 (United States); Hojjati, Alireza [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1 (Canada); Linder, Eric, E-mail: tt@astro.ucla.edu [Lawrence Berkeley National Laboratory and University of California, Berkeley, CA 94720 (United States)

    2015-02-01

    The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ∼10{sup 3} strongly lensed quasars. In an effort to assess the present capabilities of the community, to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a ''Time Delay Challenge'' (TDC). The challenge is organized as a set of ''ladders'', each containing a group of simulated data sets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' data sets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of data sets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, 2013 December 1. The TDC1 deadline was 2014 July 1. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper.

  10. Expectancy of an open-book test decreases performance on a delayed closed-book test.

    Science.gov (United States)

    Agarwal, Pooja K; Roediger, Henry L

    2011-11-01

    Two experiments examined the influence of practice with, and the expectancy of, open-book tests (students viewed studied material while taking the test) versus closed-book tests (students completed the test without viewing the studied material) on delayed retention and transfer. Using GRE materials specifically designed for open-book testing, participants studied passages and then took initial open- or closed-book tests. Open-book testing led to better initial performance than closed-book testing, but on a delayed criterial (closed-book) test both types of testing produced similar retention after a two-day delay in Experiment 1. In Experiment 2 participants were informed in advance about the type of delayed criterial test to expect (open- or closed-book). Expecting an open-book test (relative to a closed-book test) decreased participants' time spent studying and their delayed test performance on closed-book comprehension and transfer tests, demonstrating that test expectancy can influence long-term learning. Expectancy of open-book tests may impair long-term retention and transfer compared to closed-book tests, despite superior initial performance on open-book tests and students' preference for open-book tests.

  11. OSCILLATION OF NONLINEAR DELAY DIFFERENCE EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper deals with the oscillatory properties of a class of nonlinear difference equations with several delays. Sufficient criteria in the form of infinite sum for the equations to be oscillatory are obtained.

  12. Isolation Effect in Immediate and Delayed Recall

    Science.gov (United States)

    Bellezza, Francis S.; Cheney, Terry L.

    1973-01-01

    If the hypothesis of selective rehearsal is used to account for the isolation effect, then the recall of isolated items will depend both on the serial position of the isolated item and on whether recall is immediate or delayed. (Author)

  13. A simple chaotic delay differential equation

    International Nuclear Information System (INIS)

    Sprott, J.C.

    2007-01-01

    The simplest chaotic delay differential equation with a sinusoidal nonlinearity is described, including the route to chaos, Lyapunov exponent spectrum, and chaotic diffusion. It is prototypical of many other high-dimensional chaotic systems

  14. Time delay of quantum scattering processes

    International Nuclear Information System (INIS)

    Martin, P.A.

    1981-01-01

    The author presents various aspects of the theory of the time delay of scattering processes. The author mainly studies non-relativistic two-body scattering processes, first summarizing briefly the theory of simple scattering systems. (Auth.)

  15. Does Bilingualism Delay the Development of Dementia?

    Directory of Open Access Journals (Sweden)

    Amy L Atkinson

    2016-08-01

    Full Text Available It has been suggested that bilingualism (where individuals speak two languages may delay the development of dementia. However, much of the research is inconclusive. Some researchers have reported that bilingualism delays the onset and diagnosis of dementia, whilst other studies have found weak or even detrimental effects. This paper reviews a series of nine empirical studies, published up until March 2016, which investigated whether bilingualism significantly delays the onset of dementia. The article also explores whether the inconsistent findings can be attributed to differences in study designs or the definitions of bilingualism used between studies. Based on current evidence, it appears that lifelong bilingualism, where individuals frequently use both languages, may be protective against dementia. However, becoming bilingual in adulthood or using the second language infrequently is unlikely to substantially delay onset of the disease.

  16. Rich dynamics of discrete delay ecological models

    International Nuclear Information System (INIS)

    Peng Mingshu

    2005-01-01

    We study multiple bifurcations and chaotic behavior of a discrete delay ecological model. New form of chaos for the 2-D map is observed: the combination of potential period doubling and reverse period-doubling leads to cascading bubbles

  17. Four-channel delay generator model 5740

    International Nuclear Information System (INIS)

    Baumatz, D.; Milner, M.

    1978-01-01

    The 4-channel delay generator model 5740 generates 4-pulse groups in independent channels. The device offers the possibility of controlling both the time intervals between the pulses of a group and the rate of generation of groups

  18. Lauch of CERN particle accelerator delayed

    CERN Multimedia

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inSwitzerland yesterday confirmed a delay in tests of its massive new particle accelerator." (1 page)

  19. Variable Delay in port-Hamiltonian Telemanipulation

    NARCIS (Netherlands)

    Secchi, C; Stramigioli, Stefano; Fantuzzi, C.

    2006-01-01

    In several applications involving bilateral telemanipulation, master and slave act at different power scales. In this paper a strategy for passively dealing with variable communication delay in scaled port-Hamiltonian based telemanipulation over packet switched networks is proposed.

  20. Nonlinear Cournot duopoly with implementation delays

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2015-01-01

    We study the effects of two delays on the local as well as on global stability of nonlinear Cournot duopoly dynamics. The two major findings are an analytical construction of the stability switching curve on which stability is lost and the numerical confirmation of the birth of aperiodic global dynamics when the stationary state is locally unstable. The delays matters and can generate various dynamics ranging from simple to complicated dynamics.

  1. Delay in polling systems in heavy traffic

    Science.gov (United States)

    van der Mei, Robert D.

    1998-10-01

    We study the delay in asymmetric cyclic polling systems with general mixtures of gated and exhaustive service, with generally distributed service times and switch-over times, in heavy traffic. We obtain closed-form expressions for all moments of the delay incurred at each of the queues. The expressions are strikingly simple and can even be expressed as finite products of known factors. The results provide new insights into the heavy-traffic behavior of polling systems.

  2. Acceptable Channel Switching Delays for Mobile TV

    DEFF Research Database (Denmark)

    Fleury, Alexandre; Pedersen, Jakob Schou; Larsen, Lars Bo

    2011-01-01

    as well as three potential effect factors: the transition type, the test environment and the audiovisual content. The results show that delays longer than 5.7 seconds annoyed test participants, and that the transition type had a significant impact on the rating of channel switching delays. However......, neither the test environment nor the audiovisual content influenced the ratings significantly. Finally, a discussion of these results and directions for future research are proposed....

  3. Inverse Problems for Nonlinear Delay Systems

    Science.gov (United States)

    2011-03-15

    population dynamics. We consider the delay between birth and adulthood for neonate pea aphids and present a mathematical model that treats this delay as...which there is currently no known cure. For HIV, the core of the virus is composed of single-stranded viral RNA and protein components. As depicted in...at a CD4 receptor site and the viral core is injected into the cell. Once inside, the protein components enable transcription and integration of the

  4. The Strategic Perils of Delayed Differentiation

    OpenAIRE

    Krishnan S. Anand; Karan Girotra

    2007-01-01

    The value of delayed differentiation (also known as postponement) for a monopolist has been extensively studied in the operations literature. We analyze the case of (imperfectly) competitive markets with demand uncertainty, wherein the choice of supply chain configuration (i.e., early or delayed differentiation) is endogenous to the competing firms. We characterize firms' choices in equilibrium and analyze the effects of these choices on quantities sold, profits, consumer surplus, and welfare...

  5. Time delay in a multichannel formalism

    International Nuclear Information System (INIS)

    Haberzettl, Helmut; Workman, Ron

    2007-01-01

    We reexamine the time-delay formalism of Wigner, Eisenbud, and Smith, which was developed to analyze both elastic and inelastic resonances. An error in the paper of Smith has propagated through the literature. We correct this error and show how the results of Eisenbud and Smith are related. We also comment on some recent time-delay studies, based on Smith's erroneous interpretation of the Eisenbud result

  6. Comparison of delayed hydride cracking behavior of two zirconium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ponzoni, L.M.E. [CNEA – Centro Atómico Constituyentes, Hidrógeno en Materiales, Av. Gral. Paz 1499, San Martín (B1650KNA), Bs. As. (Argentina); Mieza, J.I. [CNEA – Centro Atómico Constituyentes, Hidrógeno en Materiales, Av. Gral. Paz 1499, San Martín (B1650KNA), Bs. As. (Argentina); Instituto Sabato, UNSAM–CNEA, Av. Gral. Paz 1499, San Martín (B1650KNA), Bs. As. (Argentina); De Las Heras, E. [CNEA – Centro Atómico Constituyentes, Hidrógeno en Materiales, Av. Gral. Paz 1499, San Martín (B1650KNA), Bs. As. (Argentina); Domizzi, G., E-mail: domizzi@cnea.gov.ar [CNEA – Centro Atómico Constituyentes, Hidrógeno en Materiales, Av. Gral. Paz 1499, San Martín (B1650KNA), Bs. As. (Argentina); Instituto Sabato, UNSAM–CNEA, Av. Gral. Paz 1499, San Martín (B1650KNA), Bs. As. (Argentina)

    2013-08-15

    Delayed hydride cracking (DHC) is an important failure mechanism that may occur in Zr alloys during service in water-cooled reactors. Two conditions must be attained to initiate DHC from a crack: the stress intensity factor must be higher than a threshold value called K{sub IH} and, hydrogen concentration must exceed a critical value. Currently the pressure tubes for CANDU reactor are fabricated from Zr–2.5Nb. In this paper the critical hydrogen concentration for DHC and the crack velocity of a developmental pressure tube, Excel, was evaluated and compared with that of Zr–2.5Nb. The DHC velocity values measured in Excel were higher than usually reported in Zr–2.5Nb. Due to the higher hydrogen solubility limits in Excel, its critical hydrogen concentration for DHC initiation is 10–50 wppm over that of Zr–2.5Nb in the range of 150–300 °C.

  7. Delay in the diagnosis and treatment of pulmonary tuberculosis in Uzbekistan: a cross-sectional study.

    Science.gov (United States)

    Belkina, Tatiana V; Khojiev, Doniyor S; Tillyashaykhov, Mirzagaleb N; Tigay, Zinaida N; Kudenov, Marat U; Tebbens, Jurjen Duintjer; Vlcek, Jiri

    2014-11-25

    Early diagnosis and prompt effective therapy are crucial for the prevention of tuberculosis (TB) transmission, particularly in regions with high levels of multi-drug resistant TB. This study aimed to evaluate the extent of delay in diagnosis and treatment of TB in Uzbekistan and identify associated risk factors. A cross-sectional study was performed on hospital patients with newly diagnosed TB. The time between the onset of respiratory symptoms and initiation of anti-TB treatment was assessed and delays were divided into patient, health system and total delays. Univariable and multivariable logistic regression analysis was used to evaluate determinants of diagnostic and treatment delay. Among 538 patients enrolled, the median delay from onset of symptoms until treatment with anti-TB drugs was 50 days. Analysis of the factors affecting health-seeking behaviour and timely treatment showed the presence of the patient factor. Self-medication was the first health-seeking action for 231 (43%) patients and proved to be a significant predictor of delay (p = 0.005), as well as coughing (p = 0.009), loss of weight (p = 0.001), and visiting private and primary healthcare facilities (p = 0.03 and p = 0.02, respectively). TB diagnostic and treatment delay was mainly contributed to by patient delay and should be reduced through increasing public awareness of TB symptoms and improving public health-seeking behaviour for timely initiation of anti-TB treatment. Efforts should be made to minimise irrational use of antibiotics and support interventions to restrict over-the-counter availability of antibiotics.

  8. The Limitations to Delay-Insensitivity in Asynchronous Circuits

    National Research Council Canada - National Science Library

    Martin, Alain J

    1990-01-01

    ... produced are delay-insensitive (DI). A digital circuit is DI when its correct operation is independent of the delays in operators and in the wires connecting the operators, except that the delays are finite and positive...

  9. Lag synchronization of chaotic systems with time-delayed linear ...

    Indian Academy of Sciences (India)

    delayed linear terms via impulsive control is investigated. Based on the stability theory of impulsive delayed differen- tial equations, some sufficient conditions are obtained guaranteeing the synchronized behaviours between two delayed chaotic ...

  10. Towards sensor array materials: can failure be delayed?

    Science.gov (United States)

    Mekid, Samir; Saheb, Nouari; Khan, Shafique M. A.; Qureshi, Khurram K.

    2015-06-01

    Further to prior development in enhancing structural health using smart materials, an innovative class of materials characterized by the ability to feel senses like humans, i.e. ‘nervous materials’, is discussed. Designed at all scales, these materials will enhance personnel and public safety, and secure greater reliability of products. Materials may fail suddenly, but any system wishes that failure is known in good time and delayed until safe conditions are reached. Nervous materials are expected to be the solution to this statement. This new class of materials is based on the novel concept of materials capable of feeling multiple structural and external stimuli, e.g. stress, force, pressure and temperature, while feeding information back to a controller for appropriate real-time action. The strain-stress state is developed in real time with the identified and characterized source of stimulus, with optimized time response to retrieve initial specified conditions, e.g. shape and strength. Sensors are volumetrically embedded and distributed, emulating the human nervous system. Immediate applications are in aircraft, cars, nuclear energy and robotics. Such materials will reduce maintenance costs, detect initial failures and delay them with self-healing. This article reviews the common aspects and challenges surrounding this new class of materials with types of sensors to be embedded seamlessly or inherently, including appropriate embedding manufacturing techniques with modeling and simulation methods.

  11. Delay and Denial of Shipment

    International Nuclear Information System (INIS)

    Wright, T. de; Gray, P.; Sobriera, A.C.F.; Xavier, C.C.; Schwela, U.

    2016-01-01

    Despite the strong safety and security record for shipments of Radioactive Material (RAM), Class 7 goods, transportation often continues to provide challenges as many carriers and ports (air and sea) choose not to engage in RAM product transportation. This paper discusses factors impacting the availability of regular air and sea transport routes for RAM, including: negative perception about radiation due to a lack of awareness and information about the industry; concerns about the cost and extent of training required of those who handle radioactive materials; multiplicity and diversity of regulations governing the handling, use and transport of these products; lack of harmonisation between governments in applying international regulations; and, a lack of outreach and public awareness about the needs and applications of radioactive materials. The particular issues involved in sea transport of: relatively small trade volumes; additional requirements or bans on port access, both for transit and trans-shipment; and scheduling difficulties due to commercial carrier routing decisions are also discussed. Initiatives being taken internationally, regionally and nationally to overcome these issues and examples of success are described. (author)

  12. Virtual unit delay for digital frequency adaptive T/4 delay phase-locked loop system

    DEFF Research Database (Denmark)

    Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

    2016-01-01

    /processor with a fixed sampling rate considering the cost and complexity, where the number of unit delays that have been adopted should be an integer. For instance, in conventional digital control systems, a single-phase T/4 Delay Phase-Locked Loop (PLL) system takes 50 unit delays (i.e., in a 50-Hz system...... Delay PLL system should be done in its implementation. This process will result in performance degradation in the digital control system, as the exactly required number of delays is not realized. Hence, in this paper, a Virtual Unit Delay (VUD) has been proposed to address such challenges to the digital......Digital micro-controllers/processors enable the cost-effective control of grid-connected power converter systems in terms of system monitoring, signal processing (e.g., grid synchronization), control (e.g., grid current and voltage control), etc. Normally, the control is implemented in a micro-controller...

  13. Asymptotic Behaviour and Extinction of Delay Lotka-Volterra Model with Jump-Diffusion

    Directory of Open Access Journals (Sweden)

    Dan Li

    2014-01-01

    Full Text Available This paper studies the effect of jump-diffusion random environmental perturbations on the asymptotic behaviour and extinction of Lotka-Volterra population dynamics with delays. The contributions of this paper lie in the following: (a to consider delay stochastic differential equation with jumps, we introduce a proper initial data space, in which the initial data may be discontinuous function with downward jumps; (b we show that the delay stochastic differential equation with jumps associated with our model has a unique global positive solution and give sufficient conditions that ensure stochastically ultimate boundedness, moment average boundedness in time, and asymptotic polynomial growth of our model; (c the sufficient conditions for the extinction of the system are obtained, which generalized the former results and showed that the sufficiently large random jump magnitudes and intensity (average rate of jump events arrival may lead to extinction of the population.

  14. Factors contributing to delay in parasite clearance in uncomplicated falciparum malaria in children

    Directory of Open Access Journals (Sweden)

    Sijuade Abayomi

    2010-02-01

    Full Text Available Abstract Background Drug resistance in Plasmodium falciparum is common in many endemic and other settings but there is no clear recommendation on when to change therapy when there is delay in parasite clearance after initiation of therapy in African children. Methods The factors contributing to delay in parasite clearance, defined as a clearance time > 2 d, in falciparum malaria were characterized in 2,752 prospectively studied children treated with anti-malarial drugs between 1996 and 2008. Results 1,237 of 2,752 children (45% had delay in parasite clearance. Overall 211 children (17% with delay in clearance subsequently failed therapy and they constituted 72% of those who had drug failure, i.e., 211 of 291 children. The following were independent risk factors for delay in parasite clearance at enrolment: age less than or equal to 2 years (Adjusted odds ratio [AOR] = 2.13, 95% confidence interval [CI]1.44-3.15, P 50,000/ul (AOR = 2.21, 95% CI = 1.77-2.75, P 20000/μl a day after treatment began, were independent risk factors for delay in clearance. Non-artemisinin monotherapies were associated with delay in clearance and treatment failures, and in those treated with chloroquine or amodiaquine, with pfmdr 1/pfcrt mutants. Delay in clearance significantly increased gametocyte carriage (P Conclusion Delay in parasite clearance is multifactorial, is related to drug resistance and treatment failure in uncomplicated malaria and has implications for malaria control efforts in sub-Saharan Africa.

  15. Improving Delay-Range-Dependent Stability Condition for Systems with Interval Time-Varying Delay

    Directory of Open Access Journals (Sweden)

    Wei Qian

    2013-01-01

    Full Text Available This paper discusses the delay-range-dependent stability for systems with interval time-varying delay. Through defining the new Lyapunov-Krasovskii functional and estimating the derivative of the LKF by introducing new vectors, using free matrices and reciprocally convex approach, the new delay-range-dependent stability conditions are obtained. Two well-known examples are given to illustrate the less conservatism of the proposed theoretical results.

  16. Leveraging delay discounting for health: Can time delays influence food choice?

    Science.gov (United States)

    Appelhans, Bradley M; French, Simone A; Olinger, Tamara; Bogucki, Michael; Janssen, Imke; Avery-Mamer, Elizabeth F; Powell, Lisa M

    2018-03-15

    Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines. ClinicalTrials.gov, NCT02359916. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Derivation and computation of discrete-delay and continuous-delay SDEs in mathematical biology.

    Science.gov (United States)

    Allen, Edward J

    2014-06-01

    Stochastic versions of several discrete-delay and continuous-delay differential equations, useful in mathematical biology, are derived from basic principles carefully taking into account the demographic, environmental, or physiological randomness in the dynamic processes. In particular, stochastic delay differential equation (SDDE) models are derived and studied for Nicholson's blowflies equation, Hutchinson's equation, an SIS epidemic model with delay, bacteria/phage dynamics, and glucose/insulin levels. Computational methods for approximating the SDDE models are described. Comparisons between computational solutions of the SDDEs and independently formulated Monte Carlo calculations support the accuracy of the derivations and of the computational methods.

  18. Global synchronization criteria with channel time-delay for chaotic time-delay system

    International Nuclear Information System (INIS)

    Sun Jitao

    2004-01-01

    Based on the Lyapunov stabilization theory, matrix measure, and linear matrix inequality (LMIs), this paper studies the chaos synchronization of time-delay system using the unidirectional linear error feedback coupling with time-delay. Some generic conditions of chaos synchronization with time-delay in the transmission channel is established. The chaotic Chua's circuit is used for illustration, where the coupling parameters are determined according to the criteria under which the global chaos synchronization of the time-delay coupled systems is achieved

  19. Prehospital delay in acute coronary syndrome--an analysis of the components of delay

    DEFF Research Database (Denmark)

    Ottesen, Michael Mundt; Dixen, Ulrik; Torp-Pedersen, Christian

    2004-01-01

    BACKGROUND: Prompt hospital admission is essential when treating acute coronary syndrome. Delay prior to admission is unnecessarily long. Therefore, a thorough scrutiny of the influence of characteristics, circumstantial and subjective variables on elements of prehospital delay among patients...... admitted with acute coronary syndrome is warranted. METHODS: A structured interview was conducted on 250 consecutive patients admitted alive with acute coronary syndrome. RESULTS: Median prehospital, decision, physician and transportation delays were 107, 74, 25 and 22 min, respectively. Women (n=77) had...... of acute coronary syndrome among women, and thereby contributes to unnecessary long delay to treatment. The patient's prior experience and interpretation has a significant influence on behaviour....

  20. Independence of Movement Preparation and Movement Initiation.

    Science.gov (United States)

    Haith, Adrian M; Pakpoor, Jina; Krakauer, John W

    2016-03-09

    Initiating a movement in response to a visual stimulus takes significantly longer than might be expected on the basis of neural transmission delays, but it is unclear why. In a visually guided reaching task, we forced human participants to move at lower-than-normal reaction times to test whether normal reaction times are strictly necessary for accurate movement. We found that participants were, in fact, capable of moving accurately ∼80 ms earlier than their reaction times would suggest. Reaction times thus include a seemingly unnecessary delay that accounts for approximately one-third of their duration. Close examination of participants' behavior in conventional reaction-time conditions revealed that they generated occasional, spontaneous errors in trials in which their reaction time was unusually short. The pattern of these errors could be well accounted for by a simple model in which the timing of movement initiation is independent of the timing of movement preparation. This independence provides an explanation for why reaction times are usually so sluggish: delaying the mean time of movement initiation relative to preparation reduces the risk that a movement will be initiated before it has been appropriately prepared. Our results suggest that preparation and initiation of movement are mechanistically independent and may have a distinct neural basis. The results also demonstrate that, even in strongly stimulus-driven tasks, presentation of a stimulus does not directly trigger a movement. Rather, the stimulus appears to trigger an internal decision whether to make a movement, reflecting a volitional rather than reactive mode of control. Copyright © 2016 the authors 0270-6474/16/363007-10$15.00/0.