Successful Supercooled Liver Storage for 4 Days
Berendsen, Tim A.; Bruinsma, Bote G.; Puts, Catheleyne F.; Saeidi, Nima; Usta, O. Berk; Uygun, Basak E.; Izamis, Maria-Louisa; Toner, Mehmet; Yarmush, Martin L.; Uygun, Korkut
2014-01-01
The realization of long–term human organ preservation will have groundbreaking effects on the current practice of transplantation. Herein we present a novel technique based on sub–zero non–freezing tissue preservation and extracorporeal machine perfusion that allows transplantation of rat livers preserved for up to 4 days, thereby tripling the viable preservation duration. PMID:24973919
The 4-Day School Week. The Informed Educator Series
ERIC Educational Resources Information Center
Donis-Keller, Christine
2010-01-01
This "Informed Educator" examines the use of a 4-day school week as a way to reduce expenses while using limited resources most effectively. Discussion focuses on various models of 4-day week schedules, what to do during the fifth day, and how 4-day school weeks affect extracurricular activities. Detailed discussion of financial savings, student…
2009 Summer 4-Day Work Week Evaluation Report
ERIC Educational Resources Information Center
Geneivive, David V.; DeRose, Diego; Ligas, Maria
2011-01-01
This report describes the final evaluation of a condensed work schedule, the Summer 2009 4-Day Work Week (S4-DWW), adopted by The School Board of Broward County, Florida. The goal for the program was to close the entire district for 1 day each week to reduce utility costs. Except for a few cases, district schools and offices were closed on Fridays…
The 78.4 day period of Cygnus XR-1
NASA Technical Reports Server (NTRS)
Dolan, J. F.; Caraveo, P.; Coe, M. J.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.
1979-01-01
A search for a 78.4 day modulation in the high energy X-ray flux observed with OSO-8 and in the U-band optical polarization is reported. It is suggested that if such a modulation does exist, it is more likely to be related to the rotation of the free modes of oscillation of the primary than to the existence of a third body in the system.
An Analysis of Workers' Attitudes Toward the 4-Day, 40-Hour Workweek.
ERIC Educational Resources Information Center
Dickinson, Terry L.; Wijting, Jan P.
Employees' attitudes toward a proposed 4-day, 40-hour workweek were examined relative to job and worker variables, expectations about the new workweek schedule, and job-aspect satisfactions. Employees classified by their sex, work shifts, wage schedules, and sex and work shifts differed significantly in their attitudes toward the 4-day, 40-hour…
The 4-Day Wave as Observed from the Upper Atmosphere Research Satellite Microwave Limb Sounder
NASA Technical Reports Server (NTRS)
Allen, D. R.; Stanford, J. L.; Elson, L. S.; Fishbein, E. F.; Froidevaux, L.; Waters, J. W.
1997-01-01
The "4-day wave" is an eastward moving quasi-nondispersive feature with period near 4 days occurring near the winter polar stratopause. This paper presents evidence of the 4-day feature in Microwave Limb Sounder (MLS) temperature, geopotential height, and ozone data from the late southern winters of 1992 and 1993. Space-time spectral analyses reveal a double-peaked temperature structure consisting of one peak near the stratopause and another in the lower mesosphere, with an out-of-phase relationship between the two peaks. This double- peaked structure is reminiscent of recent three-dimensional barotropic/baroclinic instability model predictions and is observed here for the first time. The height variation of the 4-day ozone signal is shown to compare well with a linear advective-photochemical tracer model. Negative regions of quasigeostrophic potential vorticity (PV) gradient and positive Eliassen-Palm flux divergence are shown to occur, consistent with instability dynamics playing a role in wave forcing. Spectral analyses of PV derived from MLS geopotential height fields reveal a 4-day signal peaking near the polar stratopause. The three-dimensional structure of the 4-day wave resembles the potential vorticity "charge" concept, wherein a PV anomaly in the atmosphere (analogous to an electrical charge in a dielectric material) induces a geopotential field, a vertically oriented temperature dipole, and circulation about the vertical axis.
Dynamics of the 4-day wave in the Southern Hemisphere polar stratosphere
Randel, W.J. ); Lait, L.R. )
1991-12-01
Dynamics of the 4-day wave in the Southern Hemisphere polar stratosphere is investigated using horizontal wind and temperature data. These were derived from synoptic maps of satellite-measured brightness temperatures, which were generated using the fast Fourier synoptic mapping technique of Salby. Circulation statistics from these data are compared to those from the National Meteorological Center (NMC) operational stratospheric analyses, demonstrating improvements afforded by detailed treatment of asynoptic sampling effects. The 4-day wave is isolated using temporally filtered data. Several events of wave growth and decay are observed in the upper stratosphere during August 1980. Derived zonal-mean and eddy statistics suggest that the 4-day wave results from an instability of the zonal-mean flow near 55[degrees]-60[degrees]S, at and above 1 mb. Inspection of climatological data suggests the source of the instability to be the [open quotes]double-jet[close quotes] structure in the upper stratosphere and mesosphere (the subtropical mesospheric jet near 30[degrees]S and the high-latitude extension of the polar night jet near 70[degrees]S). Contribution of the 4-day wave to the general circulation of the stratosphere is discussed: one feature attributable to the 4-day wave is a region of positive EP flux divergence in the upper stratosphere near 50[degrees]-60[degrees]S. 22 refs., 12 figs.
ERIC Educational Resources Information Center
President's Council on Physical Fitness and Sports, Washington, DC.
Regardless of the type of physical activity used, interval training is simply repeated periods of physical stress interspersed with recovery periods during which activity of a reduced intensity is performed. During the recovery periods, the individual usually keeps moving and does not completely recover before the next exercise interval (e.g.,…
The value of the 4-day headdown bedrest model for screening countermeasures
NASA Technical Reports Server (NTRS)
Vernikos, J.; Keil, L.; Ertl, A. C.; Wade, C. E.; Greenleaf, J. E.; Ohara, D.; Ludwig, D.
1992-01-01
In order to evaluate the benefits of periodic exposure to the +G(z) vector as a countermeasure to the physiological responses to minus 6 degree head down bedrest (HDT), we considered a two-tiered approach: (a) to use 4 days HDT as a quick and inexpensive means of screening countermeasures, (b) to use a 60 day HDT to validate the most promising candidates. The approach and results of a 4 day study are described here. Methods: Nine males were admitted to our Human Research Facility for one ambulatory control day followed by 4 days HDT and were released on the next day after completion of a peak oxygen consumption test (VO(sub 2 peak)). A battery of tests was selected and standardized to evaluate the known early effects of HDT on plasma volume, early bone markers, orthostatic tolerance, physical performance, and fluid and electrolytes and their hormone regulation. Fluid sodium (Na) and potassium (K) intake and output in the urine were monitored throughout. Plasma volume was determined with a modified Evans Blue method and orthostatic tolerance with a 60 degree head-up tilt test for 30 minutes - both of which were determined on the ambulatory control day and on day 4 of HDT. Immediately after completion of the tilt test subjects were returned to the minus 6 degree position until the next morning when a VO(sub 2 peak) (horizontal ergometer) was done. This was compared to a similar control test determined on 2 separate occasions before subject admission. Results: Four hours after going HDT produced significant decreases (p less than 0.05) in the circulating concentration of fluid and electrolyte regulating hormones. Plasma volume, orthostatic tolerance and VO(sub 2 peak) changed significantly after 4 days HDT. There was also the expected natriuresis on day 1 of HDT but no significant diuresis. The consistency of the pre-bedrest VO(sub 2 peak) tilt tests and plasma volumes was remarkable. Conclusions: The 4 day HDT model seems highly promising for screening a variety of
A time-efficient reduction of fat mass in 4 days with exercise and caloric restriction.
Calbet, J A L; Ponce-González, J G; Pérez-Suárez, I; de la Calle Herrero, J; Holmberg, H-C
2015-04-01
To determine whether a fast reduction in fat mass can be achieved in 4 days by combining caloric restriction (CR: 3.2 kcal/kg body weight per day) with exercise (8-h walking + 45-min arm cranking per day) to induce an energy deficit of ∼5000 kcal/day, 15 overweight men underwent five experimental phases: pretest, exercise + CR for 4 days (WCR), control diet + reduced exercise for 3 days (DIET), and follow-up 4 weeks (POST1) and 1 year later (POST2). During WCR, the diet consisted solely of whey protein (n = 8) or sucrose (n = 7) (0.8 g/kg body weight per day). After WCR, DIET, POST1, and POST2, fat mass was reduced by a mean of 2.1, 2.8, 3.8, and 1.9 kg (P < 0.05), with two thirds of this loss from the trunk; and lean mass by 2.8, 1.0, 0.5, and 0.4 kg, respectively. After WCR, serum glucose, insulin, homeostatic model assessment, total and low-density lipoprotein cholesterol and triglycerides were reduced, and free fatty acid and cortisol increased. Serum leptin was reduced by 64%, 50%, and 33% following WCR, DIET, and POST1, respectively (P < 0.05). The effects were similar in both groups. In conclusion, a clinically relevant reduction in fat mass can be achieved in overweight men in just 4 days by combining prolonged exercise with CR. PMID:24602091
Haig, David
2014-01-01
Background and objectives: Interbirth intervals (IBIs) mediate a trade-off between child number and child survival. Life history theory predicts that the evolutionarily optimal IBI differs for different individuals whose fitness is affected by how closely a mother spaces her children. The objective of the article is to clarify these conflicts and explore their implications for public health. Methodology: Simple models of inclusive fitness and kin conflict address the evolution of human birth-spacing. Results: Genes of infants generally favor longer intervals than genes of mothers, and infant genes of paternal origin generally favor longer IBIs than genes of maternal origin. Conclusions and implications: The colonization of maternal bodies by offspring cells (fetal microchimerism) raises the possibility that cells of older offspring could extend IBIs by interfering with the implantation of subsequent embryos. PMID:24480612
Absence of a growth hormone effect on rat soleus atrophy during a 4-day spaceflight
NASA Technical Reports Server (NTRS)
Jiang, Bian; Roy, Roland R.; Navarro, Christine; Edgerton, V. R.
1993-01-01
The effect of a 4-day-long spaceflight on the size and the enzyme properties of soleus fibers of rats and the effects of exogenous growth hormone (GH) on the atrophic response of the soleus muscle were investigated in four groups of rats: (1) control, (2) control plus GH treatment, (3) flight, and (4) flight plus GH treatment. Results showed that the fiber size and the type of myosin heavy chain expressed fibers (but not the metabolic properties) of the soleus were affected by four days of weightlessness and that the effects were not ameliorated by the administration of growth hormone.
The effects of three different mouth rinses in a 4-day supragingival plaque regrowth study
Ulkur, Feyza; Arun, Tulin; Ozdemir, Fulya
2013-01-01
Objective: This study compares the effects of three different mouth rinses with respect to reducing Streptococcus mutans (S. mutans) colony counts on the teeth and tongue surfaces. Materials and Methods: In this study, comparison tests using the alcohol-free 0.1% chlorhexidine mouth rinse, alcohol-containing essential oil mouth rinse, and alcohol-free essential oil-containing mouth rinse were conducted. Patients were instructed to avoid mechanical cleaning with either a toothbrush or toothpick for 4 days. The first samples were collected from teeth surfaces and the dorsum of the tongue after a professional cleaning, and the second samples were collected after a 4-day plaque re-growth period. The supragingival plaque from the buccal surfaces of teeth #11, 14, 31, 34 as well as samples from the dorsum of the tongue, were assessed using the Dentocult® strips. Results: The Listerine® and Ondrohexidine® groups did not show any statistically significant differences between the values of the two samples (P = 0.734, P = 0.307). The MC® group and the control group showed significantly higher results than the first sample values. The effectiveness of the mouth rinses on S. mutans colony counts from the teeth surfaces were higher in the Listerine®, Ondrohexidine®, and Mouthwash Concentrate® groups. The difference between the first and second samples of the S. mutans colony counts from the tongue surface was found to be statistically significant, and S. mutans colony counts were higher than the first sample (P = 0.015). Conclusion: Alcohol and essential oil-containing Listerine® mouth rinse, alcohol-free Ondrohexidine®, alcohol-free essential oil-containing MC® mouth rinse had the same effect on S. mutans counts, higher than the 1% alcohol solution on teeth surface. They had the ability to maintain the S. mutans counts at the same level for 4 days in patients who did not perform any mechanical oral hygiene regimen. PMID:24926216
The benefits of liposomes for chilling canine sperm for 4 days at 4°C.
Belala, Redha; Delay, Juliette; Amirat, Lamia; Ropers, Marie-Hélène; Le Guillou, Jocya; Anton, Marc; Schmitt, Eric; Thorin, Chantal; Michaud, Sandrine; Kaidi, Rachid; Tainturier, Daniel; Bencharif, Djemil
2016-05-01
This study comprises 3 experiments exploring the possible benefits and mechanism of action of liposomes for chilling (4°C) canine sperm over a period of 4 days. In the first experiment, 20 ejaculates collected from 5 Beagle dogs were chilled in an extender containing 6% low density lipoproteins (LDL) (Control), or one of 7 extenders containing different concentrations (2, 4, 6, 8, 10, 15, 20%) of liposomes (LIPO). These ejaculates were chilled over 4 days and motility was assessed daily using a Hamilton Thorne analyzer (HTM-IVOS, 14.0). The 2% LIPO obtained the best results (p=0.038) after four days (72.55% motile spermatozoa and 31.4% progressive spermatozoa). In experiment 2, 10 ejaculates were collected from same 5 dogs and chilled in 6% LDL or 2% LIPO-based extenders. Sperm integrity characteristics were assessed prior to refrigeration and every 48h for four days (D0, D2, and D4). Acrosome integrity was assessed using the FITC-PSA test (Fluorescein IsoThiocyanate-Pisum Sativum Agglutinin), plasma membrane (PM) integrity using both the hypo-osmotic swelling test (HOSt) and SYBR14/Propidium Iodide test (SYBR14/PI), and DNA integrity using the Acridine-Orange test (AO). The 2% LIPO extender provided equivalent preservation of sperm integrity parameters to the reference extender (6% LDL). In experiment 3, a Langmuir-Blodgett trough was used to evaluate the mechanistic interactions between LDL, LIPO, prostatic fluid, and the canine spermatozoal membrane during chilling. Results indicate that LDL and LIPO interact differently with the biomimetic membrane. The most likely conclusion of these findings is that LDL and liposomes employ different protective mechanisms during the chilling (4°C) of canine spermatozoa. PMID:26952759
ERIC Educational Resources Information Center
Feldhausen, Thomas
As a partial solution to the energy crisis and to solve the problem of drastically rising operating costs coupled with less state support, in 1980-81 the Liberty School District (Spangle, Washington) implemented a 4-day school week comparable to the program used by Cimarron School District #3 in New Mexico. A survey conducted in 1975 by the…
Fenton, Caroline; Wellington, Keri; Moen, Marit D; Robinson, Dean M
2007-01-01
Drospirenone 3mg with ethinylestradiol 20microg (Yaz) is a low-dose combined oral contraceptive (COC) administered in a regimen of 24 days of active tablets followed by a short hormone-free interval (4 days; 24/4 regimen). Drospirenone, unlike other synthetic progestogens used in COCs, is a 17alpha-spirolactone derivative and a 17alpha-spironolactone analogue with antimineralocorticoid and antiandrogenic properties. Drospirenone/ethinylestradiol 3mg/20microg (24/4) is approved in the US for the prevention of pregnancy in women, for the treatment of the symptoms of premenstrual dysphoric disorder (PMDD) and for the treatment of moderate acne vulgaris in women who wish to use an oral contraceptive for contraception.Drospirenone/ethinylestradiol 3mg/20microg (24/4) provided 99% contraceptive protection over 1 year of treatment in two large studies. The same treatment regimen over three treatment cycles also significantly improved the emotional and physical symptoms associated with PMDD, and improved moderate acne vulgaris over six treatment cycles in double-blind trials. It was generally well tolerated, with adverse events generally typical of those experienced with other COCs and which were most likely to occur in the first few cycles. Clinical trials indicate that drospirenone/ethinylestradiol 3mg/20microg (24/4) is a good long-term contraceptive option, and additionally offers relief of symptoms that characterise PMDD and has a favourable effect on moderate acne vulgaris. PMID:17683173
NASA Astrophysics Data System (ADS)
Matsakis, Nicholas D.; Gross, Thomas R.
Intervals are a new, higher-level primitive for parallel programming with which programmers directly construct the program schedule. Programs using intervals can be statically analyzed to ensure that they do not deadlock or contain data races. In this paper, we demonstrate the flexibility of intervals by showing how to use them to emulate common parallel control-flow constructs like barriers and signals, as well as higher-level patterns such as bounded-buffer producer-consumer. We have implemented intervals as a publicly available library for Java and Scala.
Interval polynomial positivity
NASA Technical Reports Server (NTRS)
Bose, N. K.; Kim, K. D.
1989-01-01
It is shown that a univariate interval polynomial is globally positive if and only if two extreme polynomials are globally positive. It is shown that the global positivity property of a bivariate interval polynomial is completely determined by four extreme bivariate polynomials. The cardinality of the determining set for k-variate interval polynomials is 2k. One of many possible generalizations, where vertex implication for global positivity holds, is made by considering the parameter space to be the set dual of a boxed domain.
Klare, Peter; Neu, Bruno; Schmid, Roland M; von Delius, Stefan
2016-01-01
Background In gastroenterology a sufficient colon cleansing improves adenoma detection rate and prevents the need for preterm repeat colonoscopies due to invalid preparation. It has been shown that patient education is of major importance for improvement of colon cleansing. Objective Objective of this study was to assess the function of an automated text messaging (short message service, SMS)–supported colonoscopy preparation starting 4 days before colonoscopy appointment. Methods After preevaluation to assess mobile phone usage in the patient population for relevance of this approach, a Web-based, automated SMS text messaging system was developed, following which a single-center feasibility study at a tertiary care center was performed. Patients scheduled for outpatient colonoscopy were invited to participate. Patients enrolled in the study group received automated information about dietary recommendations and bowel cleansing during colonoscopy preparation. Data of outpatient colonoscopies with regular preparation procedure were used for pair matching and served as control. Primary end point was feasibility of SMS text messaging support in colonoscopy preparation assessed as stable and satisfactory function of the system. Secondary end points were quality of bowel preparation according to the Boston Bowel Preparation Scale (BBPS) and patient satisfaction with SMS text messaging–provided information assessed by a questionnaire. Results Web-based SMS text messaging–supported colonoscopy preparation was successful and feasible in 19 of 20 patients. Mean (standard error of the mean, SEM) total BBPS score was slightly higher in the SMS group than in the control group (7.3, SEM 0.3 vs 6.4, SEM 0.2) and for each colonic region (left, transverse, and right colon). Patient satisfaction regarding SMS text messaging–based information was high. Conclusions Using SMS for colonoscopy preparation with 4 days’ guidance including dietary recommendation is a new approach
Waltemeyer, Scott D.
2002-01-01
Two regression equations were developed for estimating the 4- day, 3-year (4Q3) low-flow frequency at ungaged sites on unregulated streams in New Mexico. The first, a statewide equation for estimating the 4Q3 low-flow frequency from drainage area and average basin mean winter precipitation, was developed from the data for 50 streamflow-gaging stations that had non-zero 4Q3 low-flow frequency. The 4Q3 low-flow frequency for the 50 gaging stations ranged from 0.08 to 18.7 cubic feet per second. For this statewide equation, the average standard error of estimate was 126 percent and the coefficient of determination was 0.48. The second, an equation for estimating the 4Q3 low-flow frequency in mountainous regions from drainage area, average basin mean winter precipitation, and average basin slope, was developed from the data for 40 gaging stations located above 7,500 feet in elevation. For this regression equation, the average standard error of estimate was 94 percent and the coefficient of determination was 0.66. A U.S. Geological Survey computer-program interface for a geographical information system (GIS), called the GIS Weasel, was used to determine basin and climatic characteristics for 84 gaging stations that were not affected by regulation. Mean monthly precipitation estimates from 1961 to 1990 were used in the GIS Weasel to compute the climatic characteristics of average basin winter precipitation and annual mean precipitation. The U.S. Geological Survey National Elevation Dataset, which currently consists of the 7.5-minute, 30-meter digital elevation model for each State, was used in the GIS Weasel to compute the basin characteristics of drainage area, average basin slope, average basin elevation, and average basin aspect. Basin and climatic characteristics that were statistically significant in the regression equation with the 4Q3 low-flow frequency were drainage area, which ranged from 1.62 to 5,900 square miles; average basin mean winter precipitation, which
Patil, R.B.
1995-05-01
Traditional neural networks like multi-layered perceptrons (MLP) use example patterns, i.e., pairs of real-valued observation vectors, ({rvec x},{rvec y}), to approximate function {cflx f}({rvec x}) = {rvec y}. To determine the parameters of the approximation, a special version of the gradient descent method called back-propagation is widely used. In many situations, observations of the input and output variables are not precise; instead, we usually have intervals of possible values. The imprecision could be due to the limited accuracy of the measuring instrument or could reflect genuine uncertainty in the observed variables. In such situation input and output data consist of mixed data types; intervals and precise numbers. Function approximation in interval domains is considered in this paper. We discuss a modification of the classical backpropagation learning algorithm to interval domains. Results are presented with simple examples demonstrating few properties of nonlinear interval mapping as noise resistance and finding set of solutions to the function approximation problem.
Proper Interval Vertex Deletion
NASA Astrophysics Data System (ADS)
Villanger, Yngve
Deleting a minimum number of vertices from a graph to obtain a proper interval graph is an NP-complete problem. At WG 2010 van Bevern et al. gave an O((14k + 14) k + 1 kn 6) time algorithm by combining iterative compression, branching, and a greedy algorithm. We show that there exists a simple greedy O(n + m) time algorithm that solves the Proper Interval Vertex Deletion problem on \\{claw,net,allowbreak tent,allowbreak C_4,C_5,C_6\\}-free graphs. Combining this with branching on the forbidden structures claw,net,tent,allowbreak C_4,C_5, and C 6 enables us to get an O(kn 6 6 k ) time algorithm for Proper Interval Vertex Deletion, where k is the number of deleted vertices.
NASA Astrophysics Data System (ADS)
Sundararaman, Sathishkumar
Signature of 3-4 day planetary waves in the equatorial ionospheric F layer height and medium frequency radar winds over Tirunelveli (8.7oN) S. Sathishkumar1, R. Dhanya1, K. Emperumal1, D. Tiwari2, S. Gurubaran1 and A. Bhattacharyya2 1. Equatorial Geophysical Research Laboratory, Indian Institute of Geomagnetism, Tirunelveli, India 2. Indian Institute of Geomagnetism, Navi Mumbai, India Email: sathishmaths@gmail.com Abstract The equatorial atmosphere-ionosphere system has been studied theoretically and observationally in the past. In the equatorial atmosphere, oscillations with periods of 3-4 days are often observed in the medium frequency (MF) radar over Tirunelveli (8.7oN, 77.8oE, 1.34oN geomag. lat.). Earlier observations show the clear evidence that these waves can propagate from the stratosphere to ionosphere. A digital ionosonde has been providing useful information on several ionospheric parameters from the same site. Simultaneous observations of mesospheric winds using medium frequency radar and F-layer height (h'F) from ionosonde reveal that the 3-4 day wave was evident in both the component during the 01 June 2007 and 31 July 2007. The 3-4 day wave could have an important role in the day to day variability of the equatorial ionosphere evening uplift. Results from an extensive analysis that is being carried out in the direction of 3-4 day wave present in the ionosphere will be presented.
Interval arithmetic operations for uncertainty analysis with correlated interval variables
NASA Astrophysics Data System (ADS)
Jiang, Chao; Fu, Chun-Ming; Ni, Bing-Yu; Han, Xu
2016-08-01
A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analysis could be significantly alleviated. The correlation between interval parameters is defined by the multidimensional parallelepiped model which is convenient to describe the correlative and independent interval variables in a unified framework. The original interval variables with correlation are transformed into the standard space without correlation, and then the relationship between the original variables and the standard interval variables is obtained. The expressions of four basic interval arithmetic operations, namely addition, subtraction, multiplication, and division, are given in the standard space. Finally, several numerical examples and a two-step bar are used to demonstrate the effectiveness of the proposed method.
Interval-valued random functions and the kriging of intervals
Diamond, P.
1988-04-01
Estimation procedures using data that include some values known to lie within certain intervals are usually regarded as problems of constrained optimization. A different approach is used here. Intervals are treated as elements of a positive cone, obeying the arithmetic of interval analysis, and positive interval-valued random functions are discussed. A kriging formalism for interval-valued data is developed. It provides estimates that are themselves intervals. In this context, the condition that kriging weights be positive is seen to arise in a natural way. A numerical example is given, and the extension to universal kriging is sketched.
Experimenting with musical intervals
NASA Astrophysics Data System (ADS)
Lo Presto, Michael C.
2003-07-01
When two tuning forks of different frequency are sounded simultaneously the result is a complex wave with a repetition frequency that is the fundamental of the harmonic series to which both frequencies belong. The ear perceives this 'musical interval' as a single musical pitch with a sound quality produced by the harmonic spectrum responsible for the waveform. This waveform can be captured and displayed with data collection hardware and software. The fundamental frequency can then be calculated and compared with what would be expected from the frequencies of the tuning forks. Also, graphing software can be used to determine equations for the waveforms and predict their shapes. This experiment could be used in an introductory physics or musical acoustics course as a practical lesson in superposition of waves, basic Fourier series and the relationship between some of the ear's subjective perceptions of sound and the physical properties of the waves that cause them.
Sakata, Shinichiro; Das Gupta, Romi; Leditschke, J Fred; Kimble, Roy M
2009-01-01
Necrotising fasciitis (NF) is a fulminant and life-threatening soft tissue infection, which leads to vascular thrombosis and cutaneous ischemia. We present our experience with extensive necrotising fasciitis in a 4-day-old neonate and stress the importance of early diagnosis, modern dressings including negative pressure therapy, prompt surgical debridement and intensive care to improve the survival and cosmetic outcome of children with NF. PMID:18982332
Fallaize, Rosalind; Forster, Hannah; Macready, Anna L; Walsh, Marianne C; Mathers, John C; Brennan, Lorraine; Gibney, Eileen R; Gibney, Michael J
2014-01-01
Background Advances in nutritional assessment are continuing to embrace developments in computer technology. The online Food4Me food frequency questionnaire (FFQ) was created as an electronic system for the collection of nutrient intake data. To ensure its accuracy in assessing both nutrient and food group intake, further validation against data obtained using a reliable, but independent, instrument and assessment of its reproducibility are required. Objective The aim was to assess the reproducibility and validity of the Food4Me FFQ against a 4-day weighed food record (WFR). Methods Reproducibility of the Food4Me FFQ was assessed using test-retest methodology by asking participants to complete the FFQ on 2 occasions 4 weeks apart. To assess the validity of the Food4Me FFQ against the 4-day WFR, half the participants were also asked to complete a 4-day WFR 1 week after the first administration of the Food4Me FFQ. Level of agreement between nutrient and food group intakes estimated by the repeated Food4Me FFQ and the Food4Me FFQ and 4-day WFR were evaluated using Bland-Altman methodology and classification into quartiles of daily intake. Crude unadjusted correlation coefficients were also calculated for nutrient and food group intakes. Results In total, 100 people participated in the assessment of reproducibility (mean age 32, SD 12 years), and 49 of these (mean age 27, SD 8 years) also took part in the assessment of validity. Crude unadjusted correlations for repeated Food4Me FFQ ranged from .65 (vitamin D) to .90 (alcohol). The mean cross-classification into “exact agreement plus adjacent” was 92% for both nutrient and food group intakes, and Bland-Altman plots showed good agreement for energy-adjusted macronutrient intakes. Agreement between the Food4Me FFQ and 4-day WFR varied, with crude unadjusted correlations ranging from .23 (vitamin D) to .65 (protein, % total energy) for nutrient intakes and .11 (soups, sauces and miscellaneous foods) to .73 (yogurts
[Anaphylactic shock lasting 4 days].
Martínez-Fariñas, P; González-Arévalo, A; Martínez-Hurtado, E D; Chacón, M; García del Valle, S
2014-11-01
We present a case of a 62 year-old male scheduled for radical cystectomy, who, ten minutes into the surgery, presented with severe hypotension, tachycardia and increased airway pressure. There was no response to the administration of vasoactive drugs such as, ephedrine, phenylephrine, dopamine and norepinephrine. After ruling out several causes, we evaluated the possibility of an anaphylactic reaction. Adrenaline was given, and the patient stabilized. An adrenaline infusion and mechanical ventilation was required for four days in the critical care unit. PMID:24246959
ERIC Educational Resources Information Center
Dam, Ai
2006-01-01
Colorado law requires school districts to schedule 1080 hours per year of instructional time for secondary schools and 990 instructional hours for elementary schools. The 1080 hours equate to six hours per day for 180 days. The 990 hours equate to five and one-half hours per day. Up to 24 hours may be counted for parent-teacher conferences, staff…
Fischer-Tenhagen, C; Thiele, G; Heuwieser, W; Tenhagen, B-A
2010-06-01
Content The objective of the study was to investigate whether a treatment with hCG 4 days after AI could reduce pregnancy losses in lactating dairy cows. Cows of a dairy herd presented to the veterinarian in a fixed reproductive management protocol were treated with an Ovsynch protocol if no corpus luteum (CL) could be palpated per rectum (Group OV). Cows with a CL received cloprostenol (0.15 mg). After 2 days, these cows were treated with buserelin (0.01 mg) and received timed AI 16-20 h later (Group PG). In both treatment protocols, cows were assigned to two groups to receive 2500 IU of hCG i.v. 4 days after AI or to serve as untreated controls (Groups OV-hCG, OV-Control, PG-hCG and PG-Control). Pregnancy diagnosis was carried out 27 days after AI via ultrasonography and 39 days after AI by rectal palpation. Pregnancy losses were defined as cows being pregnant on day 27 but not pregnant on day 39 after AI. Pregnancy rate (PR) by day 27 did not differ among the four groups (35.4, 35.0, 37.0 and 38.0% for Groups OV-hCG, OV-Control, PG-hCG and PG-Control, respectively). Pregnancy losses between day 27 and day 39 after AI were smaller in hCG treated animals in summer but not in autumn and spring. Pregnancy rate by day 39 after AI was higher in PG than in OV groups, but independent of hCG-treatment. In conclusion, treatment with hCG 4 days after AI did not significantly increase PR on 39 days after AI. A positive effect of hCG on pregnancy losses during the summer months warrants further investigation. PMID:19090829
An interval model updating strategy using interval response surface models
NASA Astrophysics Data System (ADS)
Fang, Sheng-En; Zhang, Qiu-Hu; Ren, Wei-Xin
2015-08-01
Stochastic model updating provides an effective way of handling uncertainties existing in real-world structures. In general, probabilistic theories, fuzzy mathematics or interval analyses are involved in the solution of inverse problems. However in practice, probability distributions or membership functions of structural parameters are often unavailable due to insufficient information of a structure. At this moment an interval model updating procedure shows its superiority in the aspect of problem simplification since only the upper and lower bounds of parameters and responses are sought. To this end, this study develops a new concept of interval response surface models for the purpose of efficiently implementing the interval model updating procedure. The frequent interval overestimation due to the use of interval arithmetic can be maximally avoided leading to accurate estimation of parameter intervals. Meanwhile, the establishment of an interval inverse problem is highly simplified, accompanied by a saving of computational costs. By this means a relatively simple and cost-efficient interval updating process can be achieved. Lastly, the feasibility and reliability of the developed method have been verified against a numerical mass-spring system and also against a set of experimentally tested steel plates.
Effect Sizes, Confidence Intervals, and Confidence Intervals for Effect Sizes
ERIC Educational Resources Information Center
Thompson, Bruce
2007-01-01
The present article provides a primer on (a) effect sizes, (b) confidence intervals, and (c) confidence intervals for effect sizes. Additionally, various admonitions for reformed statistical practice are presented. For example, a very important implication of the realization that there are dozens of effect size statistics is that "authors must…
[Birth interval differentials in Rwanda].
Ilinigumugabo, A
1992-01-01
Data from the 1983 Rwanda Fertility Survey are the basis for this study of variations in birth intervals. An analysis of the quality of the Rwandan birth data showed it to be relatively good. The life table technique utilized in this study is explained in a section on methodology, which also describes the Rwanda Fertility Survey questionnaires. A comparison of birth intervals in which live born children died before their first birthday or survived the first birthday shows that infant mortality shortens birth intervals by an average of 5 months. The first birth interval was almost 28 months when the oldest child survived, but declined to 23 months when the oldest child died before age 1. The effect of mortality on birth intervals increased with parity, from 5 months for the first birth interval to 5.5 months for the second and third and 6.4 months for subsequent intervals. The differences amounted to 9 or 10 months for women separating at parities under 4 and over 14 months for women separating at parities of 4 or over. Birth intervals generally increased with parity, maternal age, and the duration of the union. But women entering into unions at higher ages had shorter birth intervals. In the absence of infant mortality and dissolution of the union, women attending school beyong the primary level had first birth intervals 6 months shorter on average than other women. Controlling for infant mortality and marital dissolution, women working for wages had average birth intervals of under 2 years for the first 5 births. Father's occupation had a less marked influence on birth intervals. Urban residence was associated with a shortening of the average birth interval by 6 months between the first and second birth and 5 months between the second and third births. In the first 5 births, Tutsi women had birth intervals 1.5 months longer on average than Hutu women. Women in polygamous unions did not have significantly different birth intervals except perhaps among older women
Teaching Confidence Intervals Using Simulation
ERIC Educational Resources Information Center
Hagtvedt, Reidar; Jones, Gregory Todd; Jones, Kari
2008-01-01
Confidence intervals are difficult to teach, in part because most students appear to believe they understand how to interpret them intuitively. They rarely do. To help them abandon their misconception and achieve understanding, we have developed a simulation tool that encourages experimentation with multiple confidence intervals derived from the…
Automatic Error Analysis Using Intervals
ERIC Educational Resources Information Center
Rothwell, E. J.; Cloud, M. J.
2012-01-01
A technique for automatic error analysis using interval mathematics is introduced. A comparison to standard error propagation methods shows that in cases involving complicated formulas, the interval approach gives comparable error estimates with much less effort. Several examples are considered, and numerical errors are computed using the INTLAB…
Explorations in Statistics: Confidence Intervals
ERIC Educational Resources Information Center
Curran-Everett, Douglas
2009-01-01
Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This third installment of "Explorations in Statistics" investigates confidence intervals. A confidence interval is a range that we expect, with some level of confidence, to include the true value of a population parameter…
A Review of Confidence Intervals.
ERIC Educational Resources Information Center
Mauk, Anne-Marie Kimbell
This paper summarizes information leading to the recommendation that statistical significance testing be replaced, or at least accompanied by, the reporting of effect sizes and confidence intervals. It discusses the use of confidence intervals, noting that the recent report of the American Psychological Association Task Force on Statistical…
Children's Discrimination of Melodic Intervals.
ERIC Educational Resources Information Center
Schellenberg, E. Glenn; Trehub, Sandra E.
1996-01-01
Adults and children listened to tone sequences and were required to detect changes either from intervals with simple frequency ratios to intervals with complex ratios or vice versa. Adults performed better on changes from simple to complex ratios than on the reverse changes. Similar performance was observed for 6-year olds who had never taken…
Tay, Yi L; Loong, Ai M; Hiong, Kum C; Lee, Shi J; Tng, Yvonne Y M; Wee, Nicklaus L J; Lee, Serene M L; Wong, Wai P; Chew, Shit F; Wilson, Jonathan M; Ip, Yuen K
2006-11-01
The climbing perch, Anabas testudineus, inhabits large rivers, canals, stagnant water bodies, swamps and estuaries, where it can be confronted with aerial exposure during the dry season. This study aimed to examine nitrogen excretion and metabolism in this fish during 4 days of emersion. Contrary to previous reports, A. testudineus does not possess a functional hepatic ornithineurea cycle because no carbamoyl phosphate synthetase I or III activity was detected in its liver. It was ammonotelic in water, and did not detoxify ammonia through increased urea synthesis during the 4 days of emersion. Unlike many air-breathing fishes reported elsewhere, A. testudineus could uniquely excrete ammonia during emersion at a rate similar to or higher than that of the immersed control. In spite of the fact that emersion had no significant effect on the daily ammonia excretion rate, tissue ammonia content increased significantly in the experimental fish. Thus, it can be concluded that 4 days of emersion caused an increase in ammonia production in A. testudineus, and probably because of this, a transient increase in the glutamine content in the brain occurred. Because there was a significant increase in the total essential free amino acid in the experimental fish after 2 days of emersion, it can be deduced that increased ammonia production during emersion was a result of increased amino acid catabolism and protein degradation. Our results provide evidence for the first time that A. testudineus was able to continually excrete ammonia in water containing 12 mmol l(-1) NH4Cl. During emersion, active ammonia excretion apparently occurred across the branchial and cutaneous surfaces, and ammonia concentrations in water samples collected from these surfaces increased to 20 mmol l(-1). It is probable that the capacities of air-breathing and active ammonia excretion facilitated the utilization of amino acids by A. testudineus as an energy source to support locomotor activity during emersion
Yang, Chang-Bin; Wang, Yong-Chun; Gao, Yuan; Geng, Jie; Wu, Yan-Hong; Zhang, Yu; Shi, Fei; Sun, Xi-Qing
2011-12-01
Cardiovascular and musculoskeletal deconditioning occurring in long-term spaceflight requires new strategies to counteract these adverse effects. We previously reported that a short-arm centrifuge produced artificial gravity (AG), together with ergometer, has an approving effect on promoting cardiovascular function. The current study sought to investigate whether the cardiac and cerebrovascular functions were maintained and improved using a strategy of AG combined with exercise training on cardiovascular function during 4-day head-down bed rest (HDBR). Twelve healthy male subjects were assigned to a control group (CONT, n=6) and an AG combined with ergometric exercise training group (CM, n=6). Simultaneously, cardiac pumping and systolic functions, cerebral blood flow were measured before, during, and after HDBR. The results showed that AG combined with ergometric exercise caused an increase trend of number of tolerance, however, there was no significant difference between the two groups. After 4-day HDBR in the CONT group, heart rate increased significantly (59±6 vs 66±7 beats/min), while stroke volume (98±12 vs 68±13 mL) and cardiac output (6±1 vs 4±1 L/min) decreased significantly (p<0.05). All subjects had similar drops on cerebral vascular function. Volume regulating hormone aldosterone increased in both groups (by 119.9% in CONT group and 112.8% in the CM group), but only in the CONT group there were a significant changes (p<0.05). Angiotensin II was significantly increased by 140.5% after 4-day HDBR in the CONT group (p<0.05), while no significant changes were observed in the CM group. These results indicated that artificial gravity with ergometric exercise successfully eliminated changes induced by simulated weightlessness in heart rate, volume regulating hormones, and cardiac pumping function and partially maintained cardiac systolic function. Hence, a daily 1h alternating +1.0 and +2.0 Gz with 40 W exercise training appear to be an effective
VARIABLE TIME-INTERVAL GENERATOR
Gross, J.E.
1959-10-31
This patent relates to a pulse generator and more particularly to a time interval generator wherein the time interval between pulses is precisely determined. The variable time generator comprises two oscillators with one having a variable frequency output and the other a fixed frequency output. A frequency divider is connected to the variable oscillator for dividing its frequency by a selected factor and a counter is used for counting the periods of the fixed oscillator occurring during a cycle of the divided frequency of the variable oscillator. This defines the period of the variable oscillator in terms of that of the fixed oscillator. A circuit is provided for selecting as a time interval a predetermined number of periods of the variable oscillator. The output of the generator consists of a first pulse produced by a trigger circuit at the start of the time interval and a second pulse marking the end of the time interval produced by the same trigger circuit.
Abernathy, Emily; Cabezas, Cesar; Sun, Hong; Zheng, Qi; Chen, Min-hsin; Castillo-Solorzano, Carlos; Ortiz, Ana Cecilia; Osores, Fernando; Oliveira, Lucia; Whittembury, Alvaro; Andrus, Jon K.; Helfand, Rita F.; Icenogle, Joseph
2009-01-01
Rubella virus infection is typically diagnosed by the identification of rubella virus-specific immunoglobulin M (IgM) antibodies in serum, but approximately 50% of serum samples from rubella cases collected on the day of rash onset are negative for rubella virus-specific IgM. The ability to detect IgM in sera and oral fluids was compared with the ability to detect rubella virus RNA in oral fluids by reverse transcription-PCR (RT-PCR) by using paired samples taken within the first 4 days after rash onset from suspected rubella cases during an outbreak in Perú. Sera were tested for IgM by both indirect and capture enzyme immunoassays (EIAs), and oral fluids were tested for IgM by a capture EIA. Tests for IgM in serum were more sensitive for the confirmation of rubella than the test for IgM in oral fluid during the 4 days after rash onset. RT-PCR confirmed more suspected cases than serum IgM tests on days 1 and 2 after rash onset. The methods confirmed approximately the same number of cases on days 3 and 4 after rash onset. However, a few cases were detected by serum IgM tests but not by RT-PCR even on the day of rash onset. Nine RT-PCR-positive oral fluid specimens were shown to contain rubella virus sequences of genotype 1C. In summary, RT-PCR testing of oral fluid confirmed more rubella cases than IgM testing of either serum or oral fluid samples collected in the first 2 days after rash onset; the maximum number of confirmations of rubella cases was obtained by combining RT-PCR and serology testing. PMID:19005151
Image magnification using interval information.
Jurio, Aranzazu; Pagola, Miguel; Mesiar, Radko; Beliakov, Gleb; Bustince, Humberto
2011-11-01
In this paper, a simple and effective image-magnification algorithm based on intervals is proposed. A low-resolution image is magnified to form a high-resolution image using a block-expanding method. Our proposed method associates each pixel with an interval obtained by a weighted aggregation of the pixels in its neighborhood. From the interval and with a linear K(α) operator, we obtain the magnified image. Experimental results show that our algorithm provides a magnified image with better quality (peak signal-to-noise ratio) than several existing methods. PMID:21632304
TIME-INTERVAL MEASURING DEVICE
Gross, J.E.
1958-04-15
An electronic device for measuring the time interval between two control pulses is presented. The device incorporates part of a previous approach for time measurement, in that pulses from a constant-frequency oscillator are counted during the interval between the control pulses. To reduce the possible error in counting caused by the operation of the counter gating circuit at various points in the pulse cycle, the described device provides means for successively delaying the pulses for a fraction of the pulse period so that a final delay of one period is obtained and means for counting the pulses before and after each stage of delay during the time interval whereby a plurality of totals is obtained which may be averaged and multplied by the pulse period to obtain an accurate time- Interval measurement.
Interval estimates and their precision
NASA Astrophysics Data System (ADS)
Marek, Luboš; Vrabec, Michal
2015-06-01
A task very often met in in practice is computation of confidence interval bounds for the relative frequency within sampling without replacement. A typical situation includes preelection estimates and similar tasks. In other words, we build the confidence interval for the parameter value M in the parent population of size N on the basis of a random sample of size n. There are many ways to build this interval. We can use a normal or binomial approximation. More accurate values can be looked up in tables. We consider one more method, based on MS Excel calculations. In our paper we compare these different methods for specific values of M and we discuss when the considered methods are suitable. The aim of the article is not a publication of new theoretical methods. This article aims to show that there is a very simple way how to compute the confidence interval bounds without approximations, without tables and without other software costs.
Simple Interval Timers for Microcomputers.
ERIC Educational Resources Information Center
McInerney, M.; Burgess, G.
1985-01-01
Discusses simple interval timers for microcomputers, including (1) the Jiffy clock; (2) CPU count timers; (3) screen count timers; (4) light pen timers; and (5) chip timers. Also examines some of the general characteristics of all types of timers. (JN)
QT interval in anorexia nervosa.
Cooke, R A; Chambers, J B; Singh, R; Todd, G J; Smeeton, N C; Treasure, J; Treasure, T
1994-01-01
OBJECTIVES--To determine the incidence of a long QT interval as a marker for sudden death in patients with anorexia nervosa and to assess the effect of refeeding. To define a long QT interval by linear regression analysis and estimation of the upper limit of the confidence interval (95% CI) and to compare this with the commonly used Bazett rate correction formula. DESIGN--Prospective case control study. SETTING--Tertiary referral unit for eating disorders. SUBJECTS--41 consecutive patients with anorexia nervosa admitted over an 18 month period. 28 age and sex matched normal controls. MAIN OUTCOME MEASURES--maximum QT interval measured on 12 lead electrocardiograms. RESULTS--43.6% of the variability in the QT interval was explained by heart rate alone (p < 0.00001) and group analysis contributed a further 5.9% (p = 0.004). In 6 (15%) patients the QT interval was above the upper limit of the 95% CI for the prediction based on the control equation (NS). Two patients died suddenly; both had a QT interval at or above the upper limit of the 95% CI. In patients who reached their target weights the QT interval was significantly shorter (median 9.8 ms; p = 0.04) relative to the upper limit of the 60% CI of the control regression line, which best discriminated between patients and controls. The median Bazett rate corrected QT interval (QTc) in patients and controls was 435 v 405 ms.s-1/2 (p = 0.0004), and before and after refeeding it was 435 v 432 ms.s1/2 (NS). In 14(34%) patients and three (11%) controls the QTc was > 440 ms.s-1/2 (p = 0.053). CONCLUSIONS--The QT interval was longer in patients with anorexia nervosa than in age and sex matched controls, and there was a significant tendency to reversion to normal after refeeding. The Bazett rate correction formula overestimated the number of patients with QT prolongation and also did not show an improvement with refeeding. PMID:8068473
Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures.
Bebu, Ionut; Luta, George; Mathew, Thomas; Agan, Brian K
2016-01-01
For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR) from several studies, the number needed to treat (NNT), and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates. PMID:27322305
Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures
Bebu, Ionut; Luta, George; Mathew, Thomas; Agan, Brian K.
2016-01-01
For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR) from several studies, the number needed to treat (NNT), and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates. PMID:27322305
High resolution time interval meter
Martin, A.D.
1986-05-09
Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.
Updating representations of temporal intervals.
Danckert, James; Anderson, Britt
2015-12-01
Effectively engaging with the world depends on accurate representations of the regularities that make up that world-what we call mental models. The success of any mental model depends on the ability to adapt to changes-to 'update' the model. In prior work, we have shown that damage to the right hemisphere of the brain impairs the ability to update mental models across a range of tasks. Given the disparate nature of the tasks we have employed in this prior work (i.e. statistical learning, language acquisition, position priming, perceptual ambiguity, strategic game play), we propose that a cognitive module important for updating mental representations should be generic, in the sense that it is invoked across multiple cognitive and perceptual domains. To date, the majority of our tasks have been visual in nature. Given the ubiquity and import of temporal information in sensory experience, we examined the ability to build and update mental models of time. We had healthy individuals complete a temporal prediction task in which intervals were initially drawn from one temporal range before an unannounced switch to a different range of intervals. Separate groups had the second range of intervals switch to one that contained either longer or shorter intervals than the first range. Both groups showed significant positive correlations between perceptual and prediction accuracy. While each group updated mental models of temporal intervals, those exposed to shorter intervals did so more efficiently. Our results support the notion of generic capacity to update regularities in the environment-in this instance based on temporal information. The task developed here is well suited to investigations in neurological patients and in neuroimaging settings. PMID:26303026
Parwani, Simran R.; Parwani, Rajkumar N.; Chitnis, P. J.; Dadlani, Himanshu P.; Prasad, Sakur V. Sai
2013-01-01
Background: Chlorhexidine gluconate mouthwash has earned eponym of gold standard to treat and/or prevent periodontal disease. However, it has been reported to have local side-effects on long-term use. To explore a herbal alternative, the present study was carried out with an aim to compare the anti-plaque efficacy of a herbal mouthwash with 0.2% chlorhexidine gluconate mouthwash and normal saline. Materials and Methods: It was an examiner-blinded, parallel designed clinical trial, in which 90 pre-clinical dental students with gingival index (GI) ≤1 were enrolled. To begin with, GI and plaque index (PI) were recorded. Then, baseline plaque scores were brought to zero by professionally cleaning the teeth with scaling and polishing. After that, randomized 3 groups were made (of 30 subjects each - after excluding the drop-outs) who were refrained from regular mechanical oral hygiene measures. Subjects were asked to swish with respective mouthwash (0.2% chlorhexidine gluconate mouthwash, herbal mouthwash, or normal saline) as per therapeutic dose for 4 days. Then, GI and PI scores were re-evaluated on 5th day by the same investigator, and the differences were compared statistically by ANOVA and Student's ‘t’-test. Results and Observations: Least post-rinsing GI and PI scores were demonstrated with 0.2% chlorhexidine gluconate mouthwash, followed by herbal mouthwash and highest scores with normal saline. The difference of post-rinsing PI scores between the chlorhexidine and herbal mouthwash groups was statistically non-significant, whereas this difference was significant between chlorhexidine and saline groups, and the difference between herbal and saline groups was non-significant. It was concluded that 0.2% chlorhexidine gluconate mouthwash remains the best anti-plaque agent. However, when socio-economic factor and/or side-effects of chlorhexidine need consideration, presently tested herbal mouthwash may be considered as a good alternative. PMID:23633777
NASA Astrophysics Data System (ADS)
Camilo, F.; Reynolds, J. E.; Ransom, S. M.; Halpern, J. P.; Bogdanov, S.; Kerr, M.; Ray, P. S.; Cordes, J. M.; Sarkissian, J.; Barr, E. D.; Ferrara, E. C.
2016-03-01
In a search of the unidentified Fermi gamma-ray source 3FGL J1417.5-4402 with the Parkes radio telescope, we discovered PSR J1417-4402, a 2.66 ms pulsar having the same 5.4 day orbital period as the optical and X-ray binary identified by Strader et al. The existence of radio pulsations implies that the neutron star is currently not accreting. Substantial outflows from the companion render the radio pulsar undetectable for more than half of the orbit, and may contribute to the observed Hα emission. Our initial pulsar observations, together with the optically inferred orbit and inclination, imply a mass ratio of 0.171 ± 0.002, a companion mass of {M}2=0.33+/- 0.03 M⊙, and a neutron star mass in the range 1.77≤slant {M}1≤slant 2.13 M⊙. However, there remains a discrepancy between the distance of 4.4 kpc inferred from the optical properties of the companion and the smaller radio dispersion measure distance of 1.6 kpc. The smaller distance would reduce the inferred Roche-lobe filling factor, increase the inferred inclination angle, and decrease the masses. As a wide binary, PSR J1417-4402 differs from the radio-eclipsing black widow and redback pulsars being discovered in large numbers by Fermi. It is probably a system that began mass transfer onto the neutron star after the companion star left the main sequence. The companion should end its evolution as a He white dwarf in a 6-20 day orbit, i.e., as a typical binary millisecond pulsar companion.
Takachi, Ribeka; Ishihara, Junko; Iwasaki, Motoki; Hosoi, Satoko; Ishii, Yuri; Sasazuki, Shizuka; Sawada, Norie; Yamaji, Taiki; Shimazu, Taichi; Inoue, Manami; Tsugane, Shoichiro
2011-01-01
Background The validity of estimates of dietary intake calculated using a food frequency questionnaire (FFQ) depends on the specific population. The 138-item FFQ used in the 5-year follow-up survey for the Japan Public Health Center-based Prospective Study was initially developed for and validated in rural residents. However, the validity of estimates based on this FFQ for urban residents, whose diet and lifestyle differ from those of rural residents, has not been clarified. We examined the validity of ranking individuals according to level of dietary consumption, as estimated by this FFQ, among an urban population in Japan. Methods Among 896 candidates randomly selected from examinees of cancer screening provided by the National Cancer Center, Japan, 144 participated in the study. In 2007–2008, at an average 2.7 years after cancer screening, participants were asked to respond to the questionnaire and to provide 4-day weighed diet records (4d-DRs) for use as the reference intake. Spearman correlation coefficients (CCs) between the FFQ and 4d-DR estimates were calculated, after correction for intraindividual variation of 4d-DRs. Results The median (range) deattenuated CC for men and women was 0.57 (0.23 to 0.89) and 0.47 (0.08 to 0.94), respectively, across 45 nutrients and 0.51 (0.10 to 0.98) and 0.51 (−0.36 to 0.88) for 43 food groups. Conclusions Although the FFQ was developed for a rural population, it provided reasonably valid measures of consumption for many nutrients and food groups in middle-aged screenees living in urban areas in Japan. PMID:21963789
Uniform Continuity on Unbounded Intervals
ERIC Educational Resources Information Center
Pouso, Rodrigo Lopez
2008-01-01
We present a teaching approach to uniform continuity on unbounded intervals which, hopefully, may help to meet the following pedagogical objectives: (i) To provide students with efficient and simple criteria to decide whether a continuous function is also uniformly continuous; and (ii) To provide students with skill to recognize graphically…
Uraizee, A; Reimer, K A; Murry, C E; Jennings, R B
1987-06-01
Reactive oxygen species such as the superoxide anion (.O2-) have recently been implicated as important agents involved in causing cell death in the setting of myocardial ischemia and reperfusion. When superoxide anion is involved in ischemic injury the administration of superoxide dismutase (SOD) may limit infarct size by reducing the level of superoxide anions in the myocardium. The study described herein was done to determine whether SOD could limit myocardial infarct size when infarcts were produced in dogs by a 40 min occlusion of the circumflex coronary artery followed by 4 days of reperfusion. The animals in the SOD treatment group received a 1 hr intra-atrial infusion of SOD, at a rate of 250 U/kg/min starting 15 min after occlusion and ending 35 min after reperfusion; control dogs received a saline infusion over the same time frame. Infarct size was determined histologically and expressed as a percentage of the anatomic area at risk (AAR). Infarct size was similar in the two groups, averaging 26.2 +/- 2.5% in the control group (n = 10) and 21.1 +/- 4.8% in the SOD group (n = 11) (p = .40). Hemodynamic variables were not statistically different in the two groups during the occlusion. The transmural mean collateral blood flow at 10 min into the 40 min occlusion was 0.13 +/- 0.02 ml/min/g in the controls and 0.17 +/- 0.03 ml/min/g in the SOD group (p = NS); moreover, SOD did not alter collateral blood flow. In control dogs, infarct size was inversely related to collateral blood flow; analysis of covariance showed that SOD did not shift this relationship. Thus, SOD did not limit infarct size in this study. The results of the current study are consistent with our previous study in which allopurinol, a xanthine oxidase inhibitor, did not limit infarct size in this same experimental preparation. The results suggest that superoxide anions that are accessible to the infused SOD are not a major cause of myocyte death caused by 40 min of severe ischemia followed by
Fourier Analysis of Musical Intervals
NASA Astrophysics Data System (ADS)
LoPresto, Michael C.
2008-11-01
Use of a microphone attached to a computer to capture musical sounds and software to display their waveforms and harmonic spectra has become somewhat commonplace. A recent article in The Physics Teacher aptly demonstrated the use of MacScope2 in just such a manner as a way to teach Fourier analysis.3 A logical continuation of this project is to use MacScope not just to analyze the Fourier composition of musical tones but also musical intervals.
Acute effects of intense interval training on running mechanics.
Collins, M H; Pearsall, D J; Zavorsky, G S; Bateni, H; Turcotte, R A; Montgomery, D L
2000-02-01
The aims of this study were to determine if there are significant kinematic changes in running pattern after intense interval workouts, whether duration of recovery affects running kinematics, and whether changes in running economy are related to changes in running kinematics. Seven highly trained male endurance runners (VO2max = 72.3+/-3.3 ml x kg(-1) x min(-1); mean +/- s) performed three interval running workouts of 10 x 400 m at a speed of 5.94+/-0.19 m x s(-1) (356+/-11.2 m x min(-1)) with a minimum of 4 days recovery between runs. Recovery of 60, 120 or 180 s between each 400 m repetition was assigned at random. Before and after each workout, running economy and several kinematic variables were measured at speeds of 3.33 and 4.47 m x s(-1) (200 and 268 m x min(-1)). Speed was found to have a significant effect on shank angle, knee velocity and stride length (P < 0.05). Correlations between changes pre- and post-test for VO2 (ml x kg(-1) x min(-1)) and several kinematic variables were not significant (P > 0.05) at both speeds. In general, duration of recovery was not found to adversely affect running economy or the kinematic variables assessed, possibly because of intra-individual adaptations to fatigue. PMID:10718563
An Event Restriction Interval Theory of Tense
ERIC Educational Resources Information Center
Beamer, Brandon Robert
2012-01-01
This dissertation presents a novel theory of tense and tense-like constructions. It is named after a key theoretical component of the theory, the event restriction interval. In Event Restriction Interval (ERI) Theory, sentences are semantically evaluated relative to an index which contains two key intervals, the evaluation interval and the event…
High resolution time interval counter
Condreva, Kenneth J.
1994-01-01
A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.
High resolution time interval counter
Condreva, K.J.
1994-07-26
A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured. 3 figs.
Zapata, Francisco; Kreinovich, Vladik; Joslyn, Cliff A.; Hogan, Emilie A.
2013-08-01
To make a decision, we need to compare the values of quantities. In many practical situations, we know the values with interval uncertainty. In such situations, we need to compare intervals. Allen’s algebra describes all possible relations between intervals on the real line, and ordering relations between such intervals are well studied. In this paper, we extend this description to intervals in an arbitrary partially ordered set (poset). In particular, we explicitly describe ordering relations between intervals that generalize relation between points. As auxiliary results, we provide a logical interpretation of the relation between intervals, and extend the results about interval graphs to intervals over posets.
Pigeons' Choices between Fixed-Interval and Random-Interval Schedules: Utility of Variability?
ERIC Educational Resources Information Center
Andrzejewski, Matthew E.; Cardinal, Claudia D.; Field, Douglas P.; Flannery, Barbara A.; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N.
2005-01-01
Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the…
Min and Max Extreme Interval Values
ERIC Educational Resources Information Center
Jance, Marsha L.; Thomopoulos, Nick T.
2011-01-01
The paper shows how to find the min and max extreme interval values for the exponential and triangular distributions from the min and max uniform extreme interval values. Tables are provided to show the min and max extreme interval values for the uniform, exponential, and triangular distributions for different probabilities and observation sizes.
Familiarity-Frequency Ratings of Melodic Intervals
ERIC Educational Resources Information Center
Jeffries, Thomas B.
1972-01-01
Objective of this study was to determine subjects' reliability in rating randomly played ascending and descending melodic intervals within the octave on the basis of their familiarity with each type of interval and the frequency of their having experienced each type of interval in music. (Author/CB)
Confidence Intervals in Qtl Mapping by Bootstrapping
Visscher, P. M.; Thompson, R.; Haley, C. S.
1996-01-01
The determination of empirical confidence intervals for the location of quantitative trait loci (QTLs) was investigated using simulation. Empirical confidence intervals were calculated using a bootstrap resampling method for a backcross population derived from inbred lines. Sample sizes were either 200 or 500 individuals, and the QTL explained 1, 5, or 10% of the phenotypic variance. The method worked well in that the proportion of empirical confidence intervals that contained the simulated QTL was close to expectation. In general, the confidence intervals were slightly conservatively biased. Correlations between the test statistic and the width of the confidence interval were strongly negative, so that the stronger the evidence for a QTL segregating, the smaller the empirical confidence interval for its location. The size of the average confidence interval depended heavily on the population size and the effect of the QTL. Marker spacing had only a small effect on the average empirical confidence interval. The LOD drop-off method to calculate empirical support intervals gave confidence intervals that generally were too small, in particular if confidence intervals were calculated only for samples above a certain significance threshold. The bootstrap method is easy to implement and is useful in the analysis of experimental data. PMID:8725246
Intervals in evolutionary algorithms for global optimization
Patil, R.B.
1995-05-01
Optimization is of central concern to a number of disciplines. Interval Arithmetic methods for global optimization provide us with (guaranteed) verified results. These methods are mainly restricted to the classes of objective functions that are twice differentiable and use a simple strategy of eliminating a splitting larger regions of search space in the global optimization process. An efficient approach that combines the efficient strategy from Interval Global Optimization Methods and robustness of the Evolutionary Algorithms is proposed. In the proposed approach, search begins with randomly created interval vectors with interval widths equal to the whole domain. Before the beginning of the evolutionary process, fitness of these interval parameter vectors is defined by evaluating the objective function at the center of the initial interval vectors. In the subsequent evolutionary process the local optimization process returns an estimate of the bounds of the objective function over the interval vectors. Though these bounds may not be correct at the beginning due to large interval widths and complicated function properties, the process of reducing interval widths over time and a selection approach similar to simulated annealing helps in estimating reasonably correct bounds as the population evolves. The interval parameter vectors at these estimated bounds (local optima) are then subjected to crossover and mutation operators. This evolutionary process continues for predetermined number of generations in the search of the global optimum.
Interval velocity analysis using wave field continuation
Zhusheng, Z. )
1992-01-01
In this paper, the author proposes a new interval velocity inversion method which, based on wave field continuation theory and fuzzy decision theory, uses CMP seismic gathers to automatically estimate interval velocity and two-way travel time in layered medium. The interval velocity calculated directly from wave field continuation is not well consistent with that derived from VSP data, the former is usually higher than the latter. Three major factors which influence the accuracy of interval velocity from wave field continuation are corrected, so that the two kinds of interval velocity are well consistent. This method brings better interval velocity, adapts weak reflection waves and resists noise well. It is a feasible method.
Capacitated max -Batching with Interval Graph Compatibilities
NASA Astrophysics Data System (ADS)
Nonner, Tim
We consider the problem of partitioning interval graphs into cliques of bounded size. Each interval has a weight, and the weight of a clique is the maximum weight of any interval in the clique. This natural graph problem can be interpreted as a batch scheduling problem. Solving a long-standing open problem, we show NP-hardness, even if the bound on the clique sizes is constant. Moreover, we give a PTAS based on a novel dynamic programming technique for this case.
A note on the path interval distance.
Coons, Jane Ivy; Rusinko, Joseph
2016-06-01
The path interval distance accounts for global congruence between locally incongruent trees. We show that the path interval distance provides a lower bound for the nearest neighbor interchange distance. In contrast to the Robinson-Foulds distance, random pairs of trees are unlikely to be maximally distant from one another under the path interval distance. These features indicate that the path interval distance should play a role in phylogenomics where the comparison of trees on a fixed set of taxa is becoming increasingly important. PMID:27040521
ERIC Educational Resources Information Center
Walker, Kenneth; Timmerman, Linda
1980-01-01
Describes Navarro College's (Corsicana, TX) program to reduce kilowatt hour consumption through alternative energy sources and energy costs through transition to a four-day/40-hour work week. Presents results of studies of employee performance levels, community response, and the cost effectiveness of the program. Lists benefits for the student,…
Interval and Contour Processing in Autism
ERIC Educational Resources Information Center
Heaton, Pamela
2005-01-01
High functioning children with autism and age and intelligence matched controls participated in experiments testing perception of pitch intervals and musical contours. The finding from the interval study showed superior detection of pitch direction over small pitch distances in the autism group. On the test of contour discrimination no group…
Optimal Approximation of Quadratic Interval Functions
NASA Technical Reports Server (NTRS)
Koshelev, Misha; Taillibert, Patrick
1997-01-01
Measurements are never absolutely accurate, as a result, after each measurement, we do not get the exact value of the measured quantity; at best, we get an interval of its possible values, For dynamically changing quantities x, the additional problem is that we cannot measure them continuously; we can only measure them at certain discrete moments of time t(sub 1), t(sub 2), ... If we know that the value x(t(sub j)) at a moment t(sub j) of the last measurement was in the interval [x-(t(sub j)), x + (t(sub j))], and if we know the upper bound D on the rate with which x changes, then, for any given moment of time t, we can conclude that x(t) belongs to the interval [x-(t(sub j)) - D (t - t(sub j)), x + (t(sub j)) + D (t - t(sub j))]. This interval changes linearly with time, an is, therefore, called a linear interval function. When we process these intervals, we get an expression that is quadratic and higher order w.r.t. time t, Such "quadratic" intervals are difficult to process and therefore, it is necessary to approximate them by linear ones. In this paper, we describe an algorithm that gives the optimal approximation of quadratic interval functions by linear ones.
SINGLE-INTERVAL GAS PERMEABILITY ESTIMATION
Single-interval, steady-steady-state gas permeability testing requires estimation of pressure at a screened interval which in turn requires measurement of friction factors as a function of mass flow rate. Friction factors can be obtained by injecting air through a length of pipe...
Interval colorectal carcinoma: An unsolved debate.
Benedict, Mark; Galvao Neto, Antonio; Zhang, Xuchen
2015-12-01
Colorectal carcinoma (CRC), as the third most common new cancer diagnosis, poses a significant health risk to the population. Interval CRCs are those that appear after a negative screening test or examination. The development of interval CRCs has been shown to be multifactorial: location of exam-academic institution versus community hospital, experience of the endoscopist, quality of the procedure, age of the patient, flat versus polypoid neoplasia, genetics, hereditary gastrointestinal neoplasia, and most significantly missed or incompletely excised lesions. The rate of interval CRCs has decreased in the last decade, which has been ascribed to an increased understanding of interval disease and technological advances in the screening of high risk individuals. In this article, we aim to review the literature with regard to the multifactorial nature of interval CRCs and provide the most recent developments regarding this important gastrointestinal entity. PMID:26668498
Constructing Confidence Intervals for Qtl Location
Mangin, B.; Goffinet, B.; Rebai, A.
1994-01-01
We describe a method for constructing the confidence interval of the QTL location parameter. This method is developed in the local asymptotic framework, leading to a linear model at each position of the putative QTL. The idea is to construct a likelihood ratio test, using statistics whose asymptotic distribution does not depend on the nuisance parameters and in particular on the effect of the QTL. We show theoretical properties of the confidence interval built with this test, and compare it with the classical confidence interval using simulations. We show in particular, that our confidence interval has the correct probability of containing the true map location of the QTL, for almost all QTLs, whereas the classical confidence interval can be very biased for QTLs having small effect. PMID:7896108
Interval colorectal carcinoma: An unsolved debate
Benedict, Mark; Neto, Antonio Galvao; Zhang, Xuchen
2015-01-01
Colorectal carcinoma (CRC), as the third most common new cancer diagnosis, poses a significant health risk to the population. Interval CRCs are those that appear after a negative screening test or examination. The development of interval CRCs has been shown to be multifactorial: location of exam-academic institution versus community hospital, experience of the endoscopist, quality of the procedure, age of the patient, flat versus polypoid neoplasia, genetics, hereditary gastrointestinal neoplasia, and most significantly missed or incompletely excised lesions. The rate of interval CRCs has decreased in the last decade, which has been ascribed to an increased understanding of interval disease and technological advances in the screening of high risk individuals. In this article, we aim to review the literature with regard to the multifactorial nature of interval CRCs and provide the most recent developments regarding this important gastrointestinal entity. PMID:26668498
Technology Transfer Automated Retrieval System (TEKTRAN)
We investigate the use of confidence intervals and standard error intervals to draw conclusions regarding tests of hypotheses about normal population means. Mathematical expressions and algebraic manipulations are given, and computer simulations are performed to assess the usefulness of confidence ...
Sánchez-Molinero, F; Arnau, J
2014-10-01
The effects of: a) applications of oil drip (from aged salted pork fat) onto dry-cured ham surface and b) application of a temperature of 35°C for 4days after 234days of processing (HTST treatment) were evaluated. The oil application reduced moisture, proteolysis and white film in semimembranosus, microbial counts in adductor and the intensity of hollow extent, toasted flavour, adhesiveness, pastiness (in semimembranosus) and chewiness (in semimembranosus and biceps femoris) and increased the intensity of nutty flavour (in both muscles), aged flavour, hardness, fibrousness and overall liking (in semimembranosus). The HTST did not affect any ham characteristics. PMID:24906185
Influence of high ovarian hormones on QT interval duration in young African women
Balayssac‐Siransy, Edwige; Ouattara, Soualiho; Adoubi, Anicet; Kouamé, Chantal; Hauhouot‐Attoungbré, Marie‐Laure; Dah, Cyrille; Bogui, Pascal
2014-01-01
Abstract The longer QT interval duration observed in women compared to men is usually attributed to sexual hormones. The aim of our study was to investigate, among black African women, the influence of hormonal variations during the menstrual cycle on the duration of the QT interval. Fourteen young black African women, healthy, sedentary, aged 24 ± 1.7 years, with a regular menstrual cycle (28 ± 1 days) were selected from 59 volunteers. At each phase of their menstrual cycle, menstrual 2.9 ± 0.6 days, follicular 13 ± 1.5 days, and luteal 23.1 ± 1.4 days, an electrocardiogram was performed in supine position after a resting period of 30 min, to measure QT interval duration. QT interval was corrected by Bazett's (QTcb) and Fridericia's (QTcf) formulae. Then, blood samples were obtained to measure estradiol, progesterone, and serum electrolytes (K+, Ca2+, Mg2+). There was no significant difference in uncorrected QT intervals between the three phases of the menstrual cycle. It was the same for QTcb and QTcf. Moreover, during the menstrual cycle, we did not observe any correlation between each QT, QTcb, QTcf, and estradiol levels which raised during the follicular phase (356.61 ± 160.77 pg/mL) and progesterone levels which raised during the luteal phase (16.38 ± 5.88 ng/mL). Finally, the method of Bland and Altman demonstrated that the corrections of QT by Bazett and Fridericia formulae were not interchangeable. The results of this study showed that high levels of estradiol and progesterone in young black African women did not influence the QT, QTcb and QTcf intervals duration during the menstrual cycle. PMID:24760517
Physiology and its Importance for Reference Intervals
Sikaris, Kenneth A
2014-01-01
Reference intervals are ideally defined on apparently healthy individuals and should be distinguished from clinical decision limits that are derived from known diseased patients. Knowledge of physiological changes is a prerequisite for understanding and developing reference intervals. Reference intervals may differ for various subpopulations because of differences in their physiology, most obviously between men and women, but also in childhood, pregnancy and the elderly. Changes in laboratory measurements may be due to various physiological factors starting at birth including weaning, the active toddler, immunological learning, puberty, pregnancy, menopause and ageing. The need to partition reference intervals is required when there are significant physiological changes that need to be recognised. It is important that laboratorians are aware of these changes otherwise reference intervals that attempt to cover a widened inter-individual variability may lose their usefulness. It is virtually impossible for any laboratory to directly develop reference intervals for each of the physiological changes that are currently known, however indirect techniques can be used to develop or validate reference intervals in some difficult situations such as those for children. Physiology describes our life’s journey, and it is only when we are familiar with that journey that we can appreciate a pathological departure. PMID:24659833
ERIC Educational Resources Information Center
Hess, Melinda R.; Hogarty, Kristine Y.; Ferron, John M.; Kromrey, Jeffrey D.
2007-01-01
Monte Carlo methods were used to examine techniques for constructing confidence intervals around multivariate effect sizes. Using interval inversion and bootstrapping methods, confidence intervals were constructed around the standard estimate of Mahalanobis distance (D[superscript 2]), two bias-adjusted estimates of D[superscript 2], and Huberty's…
Importance of QT interval in clinical practice.
Ambhore, Anand; Teo, Swee-Guan; Bin Omar, Abdul Razakjr; Poh, Kian-Keong
2014-12-01
Long QT interval is an important finding that is often missed by electrocardiogram interpreters. Long QT syndrome (inherited and acquired) is a potentially lethal cardiac channelopathy that is frequently mistaken for epilepsy. We present a case of long QT syndrome with multiple cardiac arrests presenting as syncope and seizures. The long QTc interval was aggravated by hypomagnesaemia and drugs, including clarithromycin and levofloxacin. Multiple drugs can cause prolongation of the QT interval, and all physicians should bear this in mind when prescribing these drugs. PMID:25630313
Short Interval Leaf Movements of Cotton 12
Miller, Charles S.
1975-01-01
Gossypium hirsutum L. cv. Lankart plants exhibited three different types of independent short interval leaf movements which were superimposed on the circadian movements. The different types were termed SIRV (short interval rhythmical vertical), SIHM (short interval horizontal movements), and SHAKE (short stroked SIRV). The 36-minute period SIRV movements occurred at higher moisture levels. The 176-minute period SIHM occurred at lower moisture levels and ceased as the stress increased. The SHAKE movements were initiated with further stresses. The SLEEP (circadian, diurnal) movements ceased with further stress. The last to cease just prior to permanent wilting were the SHAKE movements. PMID:16659123
Intact Interval Timing in Circadian CLOCK Mutants
Cordes, Sara; Gallistel, C. R.
2008-01-01
While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/− and −/− mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing. PMID:18602902
Calibration intervals at Bendix Kansas City
James, R.T.
1980-01-01
The calibration interval evaluation methods and control in each calibrating department of the Bendix Corp., Kansas City Division is described, and a more detailed description of those employed in metrology is provided.
Combination of structural reliability and interval analysis
NASA Astrophysics Data System (ADS)
Qiu, Zhiping; Yang, Di; Elishakoff, Isaac
2008-02-01
In engineering applications, probabilistic reliability theory appears to be presently the most important method, however, in many cases precise probabilistic reliability theory cannot be considered as adequate and credible model of the real state of actual affairs. In this paper, we developed a hybrid of probabilistic and non-probabilistic reliability theory, which describes the structural uncertain parameters as interval variables when statistical data are found insufficient. By using the interval analysis, a new method for calculating the interval of the structural reliability as well as the reliability index is introduced in this paper, and the traditional probabilistic theory is incorporated with the interval analysis. Moreover, the new method preserves the useful part of the traditional probabilistic reliability theory, but removes the restriction of its strict requirement on data acquisition. Example is presented to demonstrate the feasibility and validity of the proposed theory.
Almost primes in almost all short intervals
NASA Astrophysics Data System (ADS)
TERÄVÄINEN, JONI
2016-09-01
Let $E_k$ be the set of positive integers having exactly $k$ prime factors. We show that almost all intervals $[x,x+\\log^{1+\\varepsilon} x]$ contain $E_3$ numbers, and almost all intervals $[x,x+\\log^{3.51} x]$ contain $E_2$ numbers. By this we mean that there are only $o(X)$ integers $1\\leq x\\leq X$ for which the mentioned intervals do not contain such numbers. The result for $E_3$ numbers is optimal up to the $\\varepsilon$ in the exponent. The theorem on $E_2$ numbers improves a result of Harman, which had the exponent $7+\\varepsilon$ in place of $3.51$. We will also consider general $E_k$ numbers, and find them on intervals whose lengths approach $\\log x$ as $k\\to \\infty$.
NASA Astrophysics Data System (ADS)
Lu, Dan; Ye, Ming; Hill, Mary C.
2012-09-01
Confidence intervals based on classical regression theories augmented to include prior information and credible intervals based on Bayesian theories are conceptually different ways to quantify parametric and predictive uncertainties. Because both confidence and credible intervals are used in environmental modeling, we seek to understand their differences and similarities. This is of interest in part because calculating confidence intervals typically requires tens to thousands of model runs, while Bayesian credible intervals typically require tens of thousands to millions of model runs. Given multi-Gaussian distributed observation errors, our theoretical analysis shows that, for linear or linearized-nonlinear models, confidence and credible intervals are always numerically identical when consistent prior information is used. For nonlinear models, nonlinear confidence and credible intervals can be numerically identical if parameter confidence regions defined using the approximate likelihood method and parameter credible regions estimated using Markov chain Monte Carlo realizations are numerically identical and predictions are a smooth, monotonic function of the parameters. Both occur if intrinsic model nonlinearity is small. While the conditions of Gaussian errors and small intrinsic model nonlinearity are violated by many environmental models, heuristic tests using analytical and numerical models suggest that linear and nonlinear confidence intervals can be useful approximations of uncertainty even under significantly nonideal conditions. In the context of epistemic model error for a complex synthetic nonlinear groundwater problem, the linear and nonlinear confidence and credible intervals for individual models performed similarly enough to indicate that the computationally frugal confidence intervals can be useful in many circumstances. Experiences with these groundwater models are expected to be broadly applicable to many environmental models. We suggest that for
Probability Distribution for Flowing Interval Spacing
S. Kuzio
2004-09-22
Fracture spacing is a key hydrologic parameter in analyses of matrix diffusion. Although the individual fractures that transmit flow in the saturated zone (SZ) cannot be identified directly, it is possible to determine the fractured zones that transmit flow from flow meter survey observations. The fractured zones that transmit flow as identified through borehole flow meter surveys have been defined in this report as flowing intervals. The flowing interval spacing is measured between the midpoints of each flowing interval. The determination of flowing interval spacing is important because the flowing interval spacing parameter is a key hydrologic parameter in SZ transport modeling, which impacts the extent of matrix diffusion in the SZ volcanic matrix. The output of this report is input to the ''Saturated Zone Flow and Transport Model Abstraction'' (BSC 2004 [DIRS 170042]). Specifically, the analysis of data and development of a data distribution reported herein is used to develop the uncertainty distribution for the flowing interval spacing parameter for the SZ transport abstraction model. Figure 1-1 shows the relationship of this report to other model reports that also pertain to flow and transport in the SZ. Figure 1-1 also shows the flow of key information among the SZ reports. It should be noted that Figure 1-1 does not contain a complete representation of the data and parameter inputs and outputs of all SZ reports, nor does it show inputs external to this suite of SZ reports. Use of the developed flowing interval spacing probability distribution is subject to the limitations of the assumptions discussed in Sections 5 and 6 of this analysis report. The number of fractures in a flowing interval is not known. Therefore, the flowing intervals are assumed to be composed of one flowing zone in the transport simulations. This analysis may overestimate the flowing interval spacing because the number of fractures that contribute to a flowing interval cannot be
Sunspot Time Series: Passive and Active Intervals
NASA Astrophysics Data System (ADS)
Zięba, S.; Nieckarz, Z.
2014-07-01
Solar activity slowly and irregularly decreases from the first spotless day (FSD) in the declining phase of the old sunspot cycle and systematically, but also in an irregular way, increases to the new cycle maximum after the last spotless day (LSD). The time interval between the first and the last spotless day can be called the passive interval (PI), while the time interval from the last spotless day to the first one after the new cycle maximum is the related active interval (AI). Minima of solar cycles are inside PIs, while maxima are inside AIs. In this article, we study the properties of passive and active intervals to determine the relation between them. We have found that some properties of PIs, and related AIs, differ significantly between two group of solar cycles; this has allowed us to classify Cycles 8 - 15 as passive cycles, and Cycles 17 - 23 as active ones. We conclude that the solar activity in the PI declining phase (a descending phase of the previous cycle) determines the strength of the approaching maximum in the case of active cycles, while the activity of the PI rising phase (a phase of the ongoing cycle early growth) determines the strength of passive cycles. This can have implications for solar dynamo models. Our approach indicates the important role of solar activity during the declining and the rising phases of the solar-cycle minimum.
Natural frequencies of structures with interval parameters
NASA Astrophysics Data System (ADS)
Sofi, A.; Muscolino, G.; Elishakoff, I.
2015-07-01
This paper deals with the evaluation of the lower and upper bounds of the natural frequencies of structures with uncertain-but-bounded parameters. The solution of the generalized interval eigenvalue problem is pursued by taking into account the actual variability and dependencies of uncertain structural parameters affecting the mass and stiffness matrices. To this aim, interval uncertainties are handled by applying the improved interval analysis via extra unitary interval (EUI), recently introduced by the first two authors. By associating an EUI to each uncertain-but-bounded parameter, the cases of mass and stiffness matrices affected by fully disjoint, completely or partially coincident uncertainties are considered. Then, based on sensitivity analysis, it is shown that the bounds of the interval eigenvalues can be evaluated as solution of two appropriate deterministic eigenvalue problems without requiring any combinatorial procedure. If the eigenvalues are monotonic functions of the uncertain parameters, then the exact bounds are obtained. The accuracy of the proposed method is demonstrated by numerical results concerning truss and beam structures with material and/or geometrical uncertainties.
Iwasaki, Motoki; Ishihara, Junko; Takachi, Ribeka; Todoriki, Hidemi; Yamamoto, Hiroshi; Miyano, Hiroshi; Yamaji, Taiki; Tsugane, Shoichiro
2016-01-01
Background Interest in the physiological roles of amino acids and their impact on health outcomes is substantial and growing. This interest has prompted assessment of the habitual intake of amino acids for use in epidemiologic studies and in clarifying the association between habitual intake and plasma levels of amino acids. Here, we investigated the validity of ranking individuals according to dietary amino acid intake as estimated using a food frequency questionnaire (FFQ) in comparison with intakes from dietary records (DRs) and plasma levels. Methods A total of 139 men and women selected from examinees of the cancer screening program at the Research Center for Cancer Prevention and Screening, National Cancer Center, Japan, provided 4-day weighed DRs, a semi-quantitative FFQ, and plasma samples. Plasma levels of amino acids were measured using the UF-Amino Station system. Results Spearman rank correlation coefficients of energy-adjusted intake of amino acids from the DR and FFQ ranged from 0.40 to 0.65 for men and from 0.35 to 0.46 for women. Correlation coefficients of energy-adjusted intake from the DR and plasma levels ranged from −0.40 to 0.25 for men and from −0.16 to 0.11 for women. Similarly, no significant positive correlation coefficients were observed between intake from the FFQ and plasma levels for either men or women. Conclusions We confirmed that this FFQ has moderate validity in estimating amino acid intake when 4-day weighed DRs are used as a reference method, suggesting that it is suitable for ranking individuals living in urban areas in Japan by amino acid intake. PMID:26277881
Pigeons' choices between fixed-interval and random-interval schedules: utility of variability?
Andrzejewski, Matthew E; Cardinal, Claudia D; Field, Douglas P; Flannery, Barbara A; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N
2005-03-01
Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the fixed-interval schedule. Thus the programmed delays to reinforcement on the random alternative were never shorter and were often longer than the fixed interval. Despite this feature, the fixed schedule was not strongly preferred. Increases in the probability used to generate the random interval resulted in decreased preferences for the fixed schedule. In addition, the number of consecutive choices on the preferred alternative varied directly with preference, whereas the consecutive number of choices on the nonpreferred alternative was fairly constant. The probability of choosing the random alternative was unaffected by the immediately prior interval encountered on that schedule, even when it was very long relative to the average value. The results loosely support conceptions of a "preference for variability" from foraging theory and the "utility of behavioral variability" from human decision-making literatures. PMID:15828591
Perceptual interference decays over short unfilled intervals.
Schulkind, M D
2000-09-01
The perceptual interference effect refers to the fact that object identification is directly related to the amount of information available at initial exposure. The present article investigated whether perceptual interference would dissipate when a short, unfilled interval was introduced between exposures to a degraded object. Across three experiments using both musical and pictorial stimuli, identification performance increased directly with the length of the unfilled interval. Consequently, significant perceptual interference was obtained only when the interval between exposures was relatively short (< 500 msec for melodies; < 300 msec for pictures). These results are consistent with explanations that attribute perceptual interference to increased perceptual noise created by exposures to highly degraded objects. The data also suggest that perceptual interference is mediated by systems that are not consciously controlled by the subject and that perceptual interference in the visual domain decays more rapidly than perceptual interference in the auditory domain. PMID:11105520
Intervality and coherence in complex networks.
Domínguez-García, Virginia; Johnson, Samuel; Muñoz, Miguel A
2016-06-01
Food webs-networks of predators and prey-have long been known to exhibit "intervality": species can generally be ordered along a single axis in such a way that the prey of any given predator tend to lie on unbroken compact intervals. Although the meaning of this axis-usually identified with a "niche" dimension-has remained a mystery, it is assumed to lie at the basis of the highly non-trivial structure of food webs. With this in mind, most trophic network modelling has for decades been based on assigning species a niche value by hand. However, we argue here that intervality should not be considered the cause but rather a consequence of food-web structure. First, analysing a set of 46 empirical food webs, we find that they also exhibit predator intervality: the predators of any given species are as likely to be contiguous as the prey are, but in a different ordering. Furthermore, this property is not exclusive of trophic networks: several networks of genes, neurons, metabolites, cellular machines, airports, and words are found to be approximately as interval as food webs. We go on to show that a simple model of food-web assembly which does not make use of a niche axis can nevertheless generate significant intervality. Therefore, the niche dimension (in the sense used for food-web modelling) could in fact be the consequence of other, more fundamental structural traits. We conclude that a new approach to food-web modelling is required for a deeper understanding of ecosystem assembly, structure, and function, and propose that certain topological features thought to be specific of food webs are in fact common to many complex networks. PMID:27368797
Intervality and coherence in complex networks
NASA Astrophysics Data System (ADS)
Domínguez-García, Virginia; Johnson, Samuel; Muñoz, Miguel A.
2016-06-01
Food webs—networks of predators and prey—have long been known to exhibit "intervality": species can generally be ordered along a single axis in such a way that the prey of any given predator tend to lie on unbroken compact intervals. Although the meaning of this axis—usually identified with a "niche" dimension—has remained a mystery, it is assumed to lie at the basis of the highly non-trivial structure of food webs. With this in mind, most trophic network modelling has for decades been based on assigning species a niche value by hand. However, we argue here that intervality should not be considered the cause but rather a consequence of food-web structure. First, analysing a set of 46 empirical food webs, we find that they also exhibit predator intervality: the predators of any given species are as likely to be contiguous as the prey are, but in a different ordering. Furthermore, this property is not exclusive of trophic networks: several networks of genes, neurons, metabolites, cellular machines, airports, and words are found to be approximately as interval as food webs. We go on to show that a simple model of food-web assembly which does not make use of a niche axis can nevertheless generate significant intervality. Therefore, the niche dimension (in the sense used for food-web modelling) could in fact be the consequence of other, more fundamental structural traits. We conclude that a new approach to food-web modelling is required for a deeper understanding of ecosystem assembly, structure, and function, and propose that certain topological features thought to be specific of food webs are in fact common to many complex networks.
Children's artistic responses to musical intervals.
Smith, L D; Williams, R N
1999-01-01
In one experiment, White South African boys drew pictures in response to four musical intervals. In the second, the subjects were of both sexes and drawn from White, urban Black, and rural Black populations. Six intervals were used. Drawing content was similar cross-culturally. Consonances were perceived as generally positive; dissonances, generally negative. There was also an activity dimension. Children in a lower grade drew more concrete pictures than did those in a higher grade, regardless of age. Even young listeners were fairly consistent in their responses. This suggests that perception of musical meaning is a universal rather than culturally based phenomenon. PMID:10696271
Optimal Colonoscopy Surveillance Interval after Polypectomy
Kim, Tae Oh
2016-01-01
The detection and removal of adenomatous polyps and postpolypectomy surveillance are considered important for the control of colorectal cancer (CRC). Surveillance using colonoscopy is an effective tool for preventing CRC after colorectal polypectomy, especially if compliance is good. In current practice, the intervals between colonoscopies after polypectomy are variable. Different recommendations for recognizing at risk groups and defining surveillance intervals after an initial finding of colorectal adenomas have been published. However, high-grade dysplasia and the number and size of adenomas are known major cancer predictors. Based on this, a subgroup of patients that may benefit from intensive surveillance colonoscopy can be identified. PMID:27484812
Technology Transfer Automated Retrieval System (TEKTRAN)
Improved genetic resolution and availability of sequenced genomes have made positional cloning of moderate-effect QTL (quantitative trait loci) realistic in several systems, emphasizing the need for precise and accurate derivation of positional confidence intervals (CIs). Support interval (SI) meth...
Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions
ERIC Educational Resources Information Center
Padilla, Miguel A.; Divers, Jasmin
2013-01-01
The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…
Interval scanning photomicrography of microbial cell populations.
NASA Technical Reports Server (NTRS)
Casida, L. E., Jr.
1972-01-01
A single reproducible area of the preparation in a fixed focal plane is photographically scanned at intervals during incubation. The procedure can be used for evaluating the aerobic or anaerobic growth of many microbial cells simultaneously within a population. In addition, the microscope is not restricted to the viewing of any one microculture preparation, since the slide cultures are incubated separately from the microscope.
Duration perception in crossmodally-defined intervals.
Mayer, Katja M; Di Luca, Massimiliano; Ernst, Marc O
2014-03-01
How humans perform duration judgments with multisensory stimuli is an ongoing debate. Here, we investigated how sub-second duration judgments are achieved by asking participants to compare the duration of a continuous sound to the duration of an empty interval in which onset and offset were marked by signals of different modalities using all combinations of visual, auditory and tactile stimuli. The pattern of perceived durations across five stimulus durations (ranging from 100 ms to 900 ms) follows the Vierordt Law. Furthermore, intervals with a sound as onset (audio-visual, audio-tactile) are perceived longer than intervals with a sound as offset. No modality ordering effect is found for visualtactile intervals. To infer whether a single modality-independent or multiple modality-dependent time-keeping mechanisms exist we tested whether perceived duration follows a summative or a multiplicative distortion pattern by fitting a model to all modality combinations and durations. The results confirm that perceived duration depends on sensory latency (summative distortion). Instead, we did not find evidence for multiplicative distortions. The results of the model and the behavioural data support the concept of a single time-keeping mechanism that allows for judgments of durations marked by multisensory stimuli. PMID:23953664
Sensory superstition on multiple interval schedules.
Starr, B C; Staddon, J E
1982-03-01
Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food. PMID:7069361
Sensory superstition on multiple interval schedules.
Starr, B C; Staddon, J E
1982-01-01
Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food. PMID:7069361
MEETING DATA QUALITY OBJECTIVES WITH INTERVAL INFORMATION
Immunoassay test kits are promising technologies for measuring analytes under field conditions. Frequently, these field-test kits report the analyte concentrations as falling in an interval between minimum and maximum values. Many project managers use field-test kits only for scr...
Gauss-Laguerre interval quadrature rule
NASA Astrophysics Data System (ADS)
Milovanovic, Gradimir V.; Cvetkovic, Aleksandar S.
2005-10-01
In this paper we prove the existence and uniqueness of the Gaussian interval quadrature formula with respect to the generalized Laguerre weight function. An algorithm for numerical construction has also investigated and some suitable solutions are proposed. A few numerical examples are included.
Happiness Scale Interval Study. Methodological Considerations
ERIC Educational Resources Information Center
Kalmijn, W. M.; Arends, L. R.; Veenhoven, R.
2011-01-01
The Happiness Scale Interval Study deals with survey questions on happiness, using verbal response options, such as "very happy" and "pretty happy". The aim is to estimate what degrees of happiness are denoted by such terms in different questions and languages. These degrees are expressed in numerical values on a continuous [0,10] scale, which are…
Precise Interval Timer for Software Defined Radio
NASA Technical Reports Server (NTRS)
Pozhidaev, Aleksey (Inventor)
2014-01-01
A precise digital fractional interval timer for software defined radios which vary their waveform on a packet-by-packet basis. The timer allows for variable length in the preamble of the RF packet and allows to adjust boundaries of the TDMA (Time Division Multiple Access) Slots of the receiver of an SDR based on the reception of the RF packet of interest.
Coefficient Alpha Bootstrap Confidence Interval under Nonnormality
ERIC Educational Resources Information Center
Padilla, Miguel A.; Divers, Jasmin; Newton, Matthew
2012-01-01
Three different bootstrap methods for estimating confidence intervals (CIs) for coefficient alpha were investigated. In addition, the bootstrap methods were compared with the most promising coefficient alpha CI estimation methods reported in the literature. The CI methods were assessed through a Monte Carlo simulation utilizing conditions…
Ward, A J; Kumar, M S
2010-04-01
The bio-conversion rate of Moina australiensis fed with Chlorella vulgaris grown on digested piggery effluent at three different feeding rates was determined and a 2, 3 and 4-day harvest interval strategy was investigated. This study indicates that C. vulgaris is a suitable food source for M. australiensis. A significant difference (P < or = 0.001) in the feeding rate against mean total populations was found among treatments. The increase in the amount of algae fed accelerated the production rate, and the population density peaked faster in the high C. vulgaris fed treatment. The BCR calculated from this experiment indicates that for every 1000 mg of C. vulgaris fed there was an increase of 437.9 mg of M. australiensis biomass produced. A significant difference (P < or = 0.001) in biomass production among the different harvest interval treatments was observed. The 2-day harvest interval treatment produced 7.78 g of M. australiensis followed by 6.89 g in the 3 day and 5.01 g in the 4-day harvest interval treatment. This study provides strong evidence that M. australiensis can utilise the bacterial blooms and bio-films associated with digested piggery effluent as a food source. PMID:20006491
The Rotator Interval of the Shoulder
Frank, Rachel M.; Taylor, Dean; Verma, Nikhil N.; Romeo, Anthony A.; Mologne, Timothy S.; Provencher, Matthew T.
2015-01-01
Biomechanical studies have shown that repair or plication of rotator interval (RI) ligamentous and capsular structures decreases glenohumeral joint laxity in various directions. Clinical outcomes studies have reported successful outcomes after repair or plication of these structures in patients undergoing shoulder stabilization procedures. Recent studies describing arthroscopic techniques to address these structures have intensified the debate over the potential benefit of these procedures as well as highlighted the differences between open and arthroscopic RI procedures. The purposes of this study were to review the structures of the RI and their contribution to shoulder instability, to discuss the biomechanical and clinical effects of repair or plication of rotator interval structures, and to describe the various surgical techniques used for these procedures and outcomes. PMID:26779554
Constraint-based Attribute and Interval Planning
NASA Technical Reports Server (NTRS)
Jonsson, Ari; Frank, Jeremy
2013-01-01
In this paper we describe Constraint-based Attribute and Interval Planning (CAIP), a paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm, based on temporal intervals and attributes. We then show how the plans are naturally expressed by networks of constraints, and show that the process of planning maps directly to dynamic constraint reasoning. In addition, we de ne compatibilities, a compact mechanism for describing planning domains. We describe how this framework can incorporate the use of constraint reasoning technology to improve planning. Finally, we describe EUROPA, an implementation of the CAIP framework.
Efficient computation of parameter confidence intervals
NASA Technical Reports Server (NTRS)
Murphy, Patrick C.
1987-01-01
An important step in system identification of aircraft is the estimation of stability and control derivatives from flight data along with an assessment of parameter accuracy. When the maximum likelihood estimation technique is used, parameter accuracy is commonly assessed by the Cramer-Rao lower bound. It is known, however, that in some cases the lower bound can be substantially different from the parameter variance. Under these circumstances the Cramer-Rao bounds may be misleading as an accuracy measure. This paper discusses the confidence interval estimation problem based on likelihood ratios, which offers a more general estimate of the error bounds. Four approaches are considered for computing confidence intervals of maximum likelihood parameter estimates. Each approach is applied to real flight data and compared.
Partitioned-Interval Quantum Optical Communications Receiver
NASA Technical Reports Server (NTRS)
Vilnrotter, Victor A.
2013-01-01
The proposed quantum receiver in this innovation partitions each binary signal interval into two unequal segments: a short "pre-measurement" segment in the beginning of the symbol interval used to make an initial guess with better probability than 50/50 guessing, and a much longer segment used to make the high-sensitivity signal detection via field-cancellation and photon-counting detection. It was found that by assigning as little as 10% of the total signal energy to the pre-measurement segment, the initial 50/50 guess can be improved to about 70/30, using the best available measurements such as classical coherent or "optimized Kennedy" detection.
One-way ANOVA based on interval information
NASA Astrophysics Data System (ADS)
Hesamian, Gholamreza
2016-08-01
This paper deals with extending the one-way analysis of variance (ANOVA) to the case where the observed data are represented by closed intervals rather than real numbers. In this approach, first a notion of interval random variable is introduced. Especially, a normal distribution with interval parameters is introduced to investigate hypotheses about the equality of interval means or test the homogeneity of interval variances assumption. Moreover, the least significant difference (LSD method) for investigating multiple comparison of interval means is developed when the null hypothesis about the equality of means is rejected. Then, at a given interval significance level, an index is applied to compare the interval test statistic and the related interval critical value as a criterion to accept or reject the null interval hypothesis of interest. Finally, the method of decision-making leads to some degrees to accept or reject the interval hypotheses. An applied example will be used to show the performance of this method.
Systolic Time Intervals and New Measurement Methods.
Tavakolian, Kouhyar
2016-06-01
Systolic time intervals have been used to detect and quantify the directional changes of left ventricular function. New methods of recording these cardiac timings, which are less cumbersome, have been recently developed and this has created a renewed interest and novel applications for these cardiac timings. This manuscript reviews these new methods and addresses the potential for the application of these cardiac timings for the diagnosis and prognosis of different cardiac diseases. PMID:27048269
Quantifying chaotic dynamics from interspike intervals
NASA Astrophysics Data System (ADS)
Pavlov, A. N.; Pavlova, O. N.; Mohammad, Y. K.; Shihalov, G. M.
2015-03-01
We address the problem of characterization of chaotic dynamics at the input of a threshold device described by an integrate-and-fire (IF) or a threshold crossing (TC) model from the output sequences of interspike intervals (ISIs). We consider the conditions under which quite short sequences of spiking events provide correct identification of the dynamical regime characterized by the single positive Lyapunov exponent (LE). We discuss features of detecting the second LE for both types of the considered models of events generation.
Fluctuations of healthy and unhealthy heartbeat intervals
NASA Astrophysics Data System (ADS)
Lan, Boon Leong; Toda, Mikito
2013-04-01
We show that the RR-interval fluctuations, defined as the difference between successive natural-logarithm of the RR interval, for healthy, congestive-heart-failure (CHF) and atrial-fibrillation (AF) subjects are well modeled by non-Gaussian stable distributions. Our results suggest that healthy or unhealthy RR-interval fluctuation can generally be modeled as a sum of a large number of independent physiological effects which are identically distributed with infinite variance. Furthermore, we show for the first time that one indicator —the scale parameter of the stable distribution— is sufficient to robustly distinguish the three groups of subjects. The scale parameters for healthy subjects are smaller than those for AF subjects but larger than those for CHF subjects —this ordering suggests that the scale parameter could be used to objectively quantify the severity of CHF and AF over time and also serve as an early warning signal for a healthy person when it approaches either boundary of the healthy range.
New Madrid seismic zone recurrence intervals
Schweig, E.S. Center for Earthquake Research and Information, Memphis, TN ); Ellis, M.A. )
1993-03-01
Frequency-magnitude relations in the New Madrid seismic zone suggest that great earthquakes should occur every 700--1,200 yrs, implying relatively high strain rates. These estimates are supported by some geological and GPS results. Recurrence intervals of this order should have produced about 50 km of strike-slip offset since Miocene time. No subsurface evidence for such large displacements is known within the seismic zone. Moreover, the irregular fault pattern forming a compressive step that one sees today is not compatible with large displacements. There are at least three possible interpretations of the observations of short recurrence intervals and high strain rates, but apparently youthful fault geometry and lack of major post-Miocene deformation. One is that the seismological and geodetic evidence are misleading. A second possibility is that activity in the region is cyclic. That is, the geological and geodetic observations that suggest relatively short recurrence intervals reflect a time of high, but geologically temporary, pore-fluid pressure. Zoback and Zoback have suggested such a model for intraplate seismicity in general. Alternatively, the New Madrid seismic zone is geologically young feature that has been active for only the last few tens of thousands of years. In support of this, observe an irregular fault geometry associated with a unstable compressive step, a series of en echelon and discontinuous lineaments that may define the position of a youthful linking fault, and the general absence of significant post-Eocene faulting or topography.
Easy identification of generalized common and conserved nested intervals.
de Montgolfier, Fabien; Raffinot, Mathieu; Rusu, Irena
2014-07-01
In this article we explain how to easily compute gene clusters, formalized by classical or generalized nested common or conserved intervals, between a set of K genomes represented as K permutations. A b-nested common (resp. conserved) interval I of size |I| is either an interval of size 1 or a common (resp. conserved) interval that contains another b-nested common (resp. conserved) interval of size at least |I|-b. When b=1, this corresponds to the classical notion of nested interval. We exhibit two simple algorithms to output all b-nested common or conserved intervals between K permutations in O(Kn+nocc) time, where nocc is the total number of such intervals. We also explain how to count all b-nested intervals in O(Kn) time. New properties of the family of conserved intervals are proposed to do so. PMID:24650221
Automatic Abstraction for Intervals Using Boolean Formulae
NASA Astrophysics Data System (ADS)
Brauer, Jörg; King, Andy
Traditionally, transfer functions have been manually designed for each operation in a program. Recently, however, there has been growing interest in computing transfer functions, motivated by the desire to reason about sequences of operations that constitute basic blocks. This paper focuses on deriving transfer functions for intervals - possibly the most widely used numeric domain - and shows how they can be computed from Boolean formulae which are derived through bit-blasting. This approach is entirely automatic, avoids complicated elimination algorithms, and provides a systematic way of handling wrap-arounds (integer overflows and underflows) which arise in machine arithmetic.
Symptom Interval and Patient Delay Affect Survival Outcomes in Adolescent Cancer Patients
Jin, Song Lee; Hahn, Seung Min; Kim, Hyo Sun; Shin, Yoon Jung; Kim, Sun Hee; Lee, Yoon Sun; Lyu, Chuhl Joo
2016-01-01
Purpose Unique features of adolescent cancer patients include cancer types, developmental stages, and psychosocial issues. In this study, we evaluated the relationship between diagnostic delay and survival to improve adolescent cancer care. Materials and Methods A total of 592 patients aged 0–18 years with eight common cancers were grouped according to age (adolescents, ≥10 years; children, <10 years). We retrospectively reviewed their symptom intervals (SIs, between first symptom/sign of disease and diagnosis), patient delay (PD, between first symptom/sign of disease and first contact with a physician), patient delay proportion (PDP), and overall survival (OS). Results Mean SI was significantly longer in adolescents than in children (66.4 days vs. 28.4 days; p<0.001), and OS rates were higher in patients with longer SIs (p=0.001). In children with long SIs, OS did not differ according to PDP (p=0.753). In adolescents with long SIs, OS was worse when PDP was ≥0.6 (67.2%) than <0.6 (95.5%, p=0.007). In a multivariate analysis, adolescents in the long SI/PDP ≥0.6 group tended to have a higher hazard ratio (HR, 6.483; p=0.069) than those in the long SI/PDP <0.6 group (HR=1, reference). Conclusion Adolescents with a long SI/PDP ≥0.6 had lower survival rates than those with a short SI/all PDP or a long SI/PDP <0.6. They should be encouraged to seek prompt medical assistance by a physician or oncologist to lessen PDs. PMID:26996554
Optimal ABC inventory classification using interval programming
NASA Astrophysics Data System (ADS)
Rezaei, Jafar; Salimi, Negin
2015-08-01
Inventory classification is one of the most important activities in inventory management, whereby inventories are classified into three or more classes. Several inventory classifications have been proposed in the literature, almost all of which have two main shortcomings in common. That is, the previous methods mainly rely on an expert opinion to derive the importance of the classification criteria which results in subjective classification, and they need precise item parameters before implementing the classification. While the problem has been predominantly considered as a multi-criteria, we examine the problem from a different perspective, proposing a novel optimisation model for ABC inventory classification in the form of an interval programming problem. The proposed interval programming model has two important features compared to the existing methods: it provides optimal results instead of an expert-based classification and it does not require precise values of item parameters, which are not almost always available before classification. Finally, by illustrating the proposed classification model in the form of numerical example, conclusion and suggestions for future works are presented.
Happiness Scale Interval Study. Methodological Considerations.
Kalmijn, W M; Arends, L R; Veenhoven, R
2011-07-01
The Happiness Scale Interval Study deals with survey questions on happiness, using verbal response options, such as 'very happy' and 'pretty happy'. The aim is to estimate what degrees of happiness are denoted by such terms in different questions and languages. These degrees are expressed in numerical values on a continuous [0,10] scale, which are then used to compute 'transformed' means and standard deviations. Transforming scores on different questions to the same scale allows to broadening the World Database of Happiness considerably. The central purpose of the Happiness Scale Interval Study is to identify the happiness values at which respondents change their judgment from e.g. 'very happy' to 'pretty happy' or the reverse. This paper deals with the methodological/statistical aspects of this approach. The central question is always how to convert the frequencies at which the different possible responses to the same question given by a sample into information on the happiness distribution in the relevant population. The primary (cl)aim of this approach is to achieve this in a (more) valid way. To this end, a model is introduced that allows for dealing with happiness as a latent continuous random variable, in spite of the fact that it is measured as a discrete one. The [0,10] scale is partitioned in as many contiguous parts as the number of possible ratings in the primary scale sums up to. Any subject with a (self-perceived) happiness in the same subinterval is assumed to select the same response. For the probability density function of this happiness random variable, two options are discussed. The first one postulates a uniform distribution within each of the different subintervals of the [0,10] scale. On the basis of these results, the mean value and variance of the complete distribution can be estimated. The method is described, including the precision of the estimates obtained in this way. The second option assumes the happiness distribution to be described
Short-interval estimations of trigonometric parallaxes
NASA Technical Reports Server (NTRS)
Gatewood, G.; Stein, J.; Difatta, C.; Kiewiet De Jonge, J.; Prosser, J.; Reiland, T.
1985-01-01
A technique for estimating trigonometric parallaxes in a matter of days or weeks is presented. The technique relies on the discrepancy between the instantaneous proper motion and the proper motion of a star. The main sources of error in the method are the standard error of the individual observations (0.004 arcsec) and the arbitrary limit placed on the observation interval. The parallactic motion of an MO dwarf of known parallax and a blue magnitude of 11.2 is determined. The slope inferred is within 10 percent of the value (0.555 arcsec) derived from a 1.5-year study of Barnard's star. It is concluded that the technique, if used on the same time scale as conventional techniques, would yield results of much higher accuracy.
The effect of instrumental timbre on interval discrimination.
Zarate, Jean Mary; Ritson, Caroline R; Poeppel, David
2013-01-01
We tested non-musicians and musicians in an auditory psychophysical experiment to assess the effects of timbre manipulation on pitch-interval discrimination. Both groups were asked to indicate the larger of two presented intervals, comprised of four sequentially presented pitches; the second or fourth stimulus within a trial was either a sinusoidal (or "pure"), flute, piano, or synthetic voice tone, while the remaining three stimuli were all pure tones. The interval-discrimination tasks were administered parametrically to assess performance across varying pitch distances between intervals ("interval-differences"). Irrespective of timbre, musicians displayed a steady improvement across interval-differences, while non-musicians only demonstrated enhanced interval discrimination at an interval-difference of 100 cents (one semitone in Western music). Surprisingly, the best discrimination performance across both groups was observed with pure-tone intervals, followed by intervals containing a piano tone. More specifically, we observed that: 1) timbre changes within a trial affect interval discrimination; and 2) the broad spectral characteristics of an instrumental timbre may influence perceived pitch or interval magnitude and make interval discrimination more difficult. PMID:24066179
Pigeons' Memory for Number of Events: Effects of Intertrial Interval and Delay Interval Illumination
ERIC Educational Resources Information Center
Hope, Chris; Santi, Angelo
2004-01-01
In Experiment 1, pigeons were trained at a 0-s baseline delay to discriminate sequences of light flashes (illumination of the feeder) that varied in number but not time (2f/4s and 8f/4s). During training, the intertrial interval was illuminated by the houselight for Group Light, but it was dark for Group Dark. Testing conducted with dark delay…
ERIC Educational Resources Information Center
Hoekstra, Rink; Johnson, Addie; Kiers, Henk A. L.
2012-01-01
The use of confidence intervals (CIs) as an addition or as an alternative to null hypothesis significance testing (NHST) has been promoted as a means to make researchers more aware of the uncertainty that is inherent in statistical inference. Little is known, however, about whether presenting results via CIs affects how readers judge the…
Pitch strength of regular-interval click trains with different length “runs” of regular intervals
Yost, William A.; Mapes-Riordan, Dan; Shofner, William; Dye, Raymond; Sheft, Stanley
2009-01-01
Click trains were generated with first- and second-order statistics following Kaernbach and Demany [J. Acoust. Soc. Am. 104, 2298–2306 (1998)]. First-order intervals are between successive clicks, while second-order intervals are those between every other click. Click trains were generated with a repeating alternation of fixed and random intervals which produce a pitch at the reciprocal of the duration of the fixed interval. The intervals were then randomly shuffled and compared to the unshuffled, alternating click trains in pitch-strength comparison experiments. In almost all comparisons for the first-order interval stimuli, the shuffled-interval click trains had a stronger pitch strength than the unshuffled-interval click trains. The shuffled-interval click trains only produced stronger pitches for second-order interval stimuli when the click trains were unfiltered. Several experimental conditions and an analysis of runs of regular and random intervals in these click trains suggest that the auditory system is sensitive to runs of regular intervals in a stimulus that contains a mix of regular and random intervals. These results indicate that fine-structure regularity plays a more important role in pitch perception than randomness, and that the long-term autocorrelation function or spectra of these click trains are not good predictors of pitch strength. PMID:15957774
About Hemispheric Differences in the Processing of Temporal Intervals
ERIC Educational Resources Information Center
Grondin, S.; Girard, C.
2005-01-01
The purpose of the present study was to identify differences between cerebral hemispheres for processing temporal intervals ranging from .9 to 1.4s. The intervals to be judged were marked by series of brief visual signals located in the left or the right visual field. Series of three (two standards and one comparison) or five intervals (four…
46 CFR 176.675 - Extension of examination intervals.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Extension of examination intervals. 176.675 Section 176... 100 GROSS TONS) INSPECTION AND CERTIFICATION Hull and Tailshaft Examinations § 176.675 Extension of examination intervals. The intervals between drydock examinations and internal structural...
Application of Sequential Interval Estimation to Adaptive Mastery Testing
ERIC Educational Resources Information Center
Chang, Yuan-chin Ivan
2005-01-01
In this paper, we apply sequential one-sided confidence interval estimation procedures with beta-protection to adaptive mastery testing. The procedures of fixed-width and fixed proportional accuracy confidence interval estimation can be viewed as extensions of one-sided confidence interval procedures. It can be shown that the adaptive mastery…
Central Difference Interval Method for Solving the Wave Equation
Szyszka, Barbara
2010-09-30
This paper presents path of construction the interval method of second order for solving the wave equation. Taken into consideration is the central difference interval method for one-dimensional partial differential equation. Numerical results, obtained by two presented algorithms, in floating-point interval arithmetic are considered.
High-intensity interval training: Modulating interval duration in overweight/obese men
Smith-Ryan, Abbie E.; Melvin, Malia N.; Wingfield, Hailee L.
2015-01-01
Introduction High-intensity interval training (HIIT) is a time-efficient strategy shown to induce various cardiovascular and metabolic adaptations. Little is known about the optimal tolerable combination of intensity and volume necessary for adaptations, especially in clinical populations. Objectives In a randomized controlled pilot design, we evaluated the effects of two types of interval training protocols, varying in intensity and interval duration, on clinical outcomes in overweight/obese men. Methods Twenty-five men [body mass index (BMI) > 25 kg·m2] completed baseline body composition measures: fat mass (FM), lean mass (LM) and percent body fat (%BF) and fasting blood glucose, lipids and insulin (IN). A graded exercise cycling test was completed for peak oxygen consumption (VO2peak) and power output (PO). Participants were randomly assigned to high-intensity short interval (1MIN-HIIT), high-intensity interval (2MIN-HIIT) or control groups. 1MIN-HIIT and 2MIN-HIIT completed 3 weeks of cycling interval training, 3 days/week, consisting of either 10 × 1 min bouts at 90% PO with 1 min rests (1MIN-HIIT) or 5 × 2 min bouts with 1 min rests at undulating intensities (80%–100%) (2MIN-HIIT). Results There were no significant training effects on FM (Δ1.06 ± 1.25 kg) or %BF (Δ1.13% ± 1.88%), compared to CON. Increases in LM were not significant but increased by 1.7 kg and 2.1 kg for 1MIN and 2MIN-HIIT groups, respectively. Increases in VO2peak were also not significant for 1MIN (3.4 ml·kg−1·min−1) or 2MIN groups (2.7 ml·kg−1·min−1). IN sensitivity (HOMA-IR) improved for both training groups (Δ −2.78 ± 3.48 units; p < 0.05) compared to CON. Conclusion HIIT may be an effective short-term strategy to improve cardiorespiratory fitness and IN sensitivity in overweight males. PMID:25913937
Function approximation using adaptive and overlapping intervals
Patil, R.B.
1995-05-01
A problem common to many disciplines is to approximate a function given only the values of the function at various points in input variable space. A method is proposed for approximating a function of several to one variable. The model takes the form of weighted averaging of overlapping basis functions defined over intervals. The number of such basis functions and their parameters (widths and centers) are automatically determined using given training data and a learning algorithm. The proposed algorithm can be seen as placing a nonuniform multidimensional grid in the input domain with overlapping cells. The non-uniformity and overlap of the cells is achieved by a learning algorithm to optimize a given objective function. This approach is motivated by the fuzzy modeling approach and a learning algorithms used for clustering and classification in pattern recognition. The basics of why and how the approach works are given. Few examples of nonlinear regression and classification are modeled. The relationship between the proposed technique, radial basis neural networks, kernel regression, probabilistic neural networks, and fuzzy modeling is explained. Finally advantages and disadvantages are discussed.
The Interval approach to braneworld gravity
Carena, Marcela; Lykken, Joseph D.; Park, Minjoon; /Chicago U., EFI
2005-06-01
Gravity in five-dimensional braneworld backgrounds may exhibit extra scalar degrees of freedom with problematic features, including kinetic ghosts and strong coupling behavior. Analysis of such effects is hampered by the standard heuristic approaches to braneworld gravity, which use the equations of motion as the starting point, supplemented by orbifold projections and junction conditions. Here we develop the interval approach to braneworld gravity, which begins with an action principle. This shows how to implement general covariance, despite allowing metric fluctuations that do not vanish on the boundaries. We reproduce simple Z{sub 2} orbifolds of gravity, even though in this approach we never perform a Z{sub 2} projection. We introduce a family of ''straight gauges'', which are bulk coordinate systems in which both branes appear as straight slices in a single coordinate patch. Straight gauges are extremely useful for analyzing metric fluctuations in braneworld models. By explicit gauge fixing, we show that a general AdS{sub 5}/AdS{sub 4} setup with two branes has at most a radion, but no physical ''brane-bending'' modes.
Statistical Properties of Extreme Solar Activity Intervals
NASA Astrophysics Data System (ADS)
Lioznova, A. V.; Blinov, A. V.
2014-01-01
A study of long-term solar variability reflected in indirect indices of past solar activity leads to stimulating results. We compare the statistics of intervals of very low and very high solar activity derived from two cosmogenic radionuclide records and look for consistency in their timing and physical interpretation. According to the applied criteria, the numbers of minima and of maxima are 61 and 68, respectively, from the 10Be record, and 42 and 46 from the 14C record. The difference between the enhanced and depressed states of solar activity becomes apparent in the difference in their statistical distributions. We find no correlation between the level or type (minimum or maximum) of an extremum and the level or type of the predecessor. The hypothesis of solar activity as a periodic process on the millennial time scale is not supported by the existing proxies. A new homogeneous series of 10Be measurements in polar ice covering the Holocene would be of great value for eliminating the existing discrepancy in the available solar activity reconstructions.
An Investigation of Interval Management Displays
NASA Technical Reports Server (NTRS)
Swieringa, Kurt A.; Wilson, Sara R.; Shay, Rick
2015-01-01
NASA's first Air Traffic Management (ATM) Technology Demonstration (ATD-1) was created to transition the most mature ATM technologies from the laboratory to the National Airspace System. One selected technology is Interval Management (IM), which uses onboard aircraft automation to compute speeds that help the flight crew achieve and maintain precise spacing behind a preceding aircraft. Since ATD-1 focuses on a near-term environment, the ATD-1 flight demonstration prototype requires radio voice communication to issue an IM clearance. Retrofit IM displays will enable pilots to both enter information into the IM avionics and monitor IM operation. These displays could consist of an interface to enter data from an IM clearance and also an auxiliary display that presents critical information in the primary field-of-view. A human-in-the-loop experiment was conducted to examine usability and acceptability of retrofit IM displays, which flight crews found acceptable. Results also indicate the need for salient alerting when new speeds are generated and the desire to have a primary field of view display available that can display text and graphic trend indicators.
Statistical Coding and Decoding of Heartbeat Intervals
Lucena, Fausto; Barros, Allan Kardec; Príncipe, José C.; Ohnishi, Noboru
2011-01-01
The heart integrates neuroregulatory messages into specific bands of frequency, such that the overall amplitude spectrum of the cardiac output reflects the variations of the autonomic nervous system. This modulatory mechanism seems to be well adjusted to the unpredictability of the cardiac demand, maintaining a proper cardiac regulation. A longstanding theory holds that biological organisms facing an ever-changing environment are likely to evolve adaptive mechanisms to extract essential features in order to adjust their behavior. The key question, however, has been to understand how the neural circuitry self-organizes these feature detectors to select behaviorally relevant information. Previous studies in computational perception suggest that a neural population enhances information that is important for survival by minimizing the statistical redundancy of the stimuli. Herein we investigate whether the cardiac system makes use of a redundancy reduction strategy to regulate the cardiac rhythm. Based on a network of neural filters optimized to code heartbeat intervals, we learn a population code that maximizes the information across the neural ensemble. The emerging population code displays filter tuning proprieties whose characteristics explain diverse aspects of the autonomic cardiac regulation, such as the compromise between fast and slow cardiac responses. We show that the filters yield responses that are quantitatively similar to observed heart rate responses during direct sympathetic or parasympathetic nerve stimulation. Our findings suggest that the heart decodes autonomic stimuli according to information theory principles analogous to how perceptual cues are encoded by sensory systems. PMID:21694763
Wood, Kimberly M; Olive, Brittany; LaValle, Kaylyn; Thompson, Heather; Greer, Kevin; Astorino, Todd A
2016-01-01
High-intensity interval training (HIIT) and sprint interval training (SIT) elicit similar cardiovascular and metabolic adaptations vs. endurance training. No study, however, has investigated acute physiological changes during HIIT vs. SIT. This study compared acute changes in heart rate (HR), blood lactate concentration (BLa), oxygen uptake (VO2), affect, and rating of perceived exertion (RPE) during HIIT and SIT. Active adults (4 women and 8 men, age = 24.2 ± 6.2 years) initially performed a VO2max test to determine workload for both sessions on the cycle ergometer, whose order was randomized. Sprint interval training consisted of 8 bouts of 30 seconds of all-out cycling at 130% of maximum Watts (Wmax). High-intensity interval training consisted of eight 60-second bouts at 85% Wmax. Heart rate, VO2, BLa, affect, and RPE were continuously assessed throughout exercise. Repeated-measures analysis of variance revealed a significant difference between HIIT and SIT for VO2 (p < 0.001), HR (p < 0.001), RPE (p = 0.03), and BLa (p = 0.049). Conversely, there was no significant difference between regimens for affect (p = 0.12). Energy expenditure was significantly higher (p = 0.02) in HIIT (209.3 ± 40.3 kcal) vs. SIT (193.5 ± 39.6 kcal). During HIIT, subjects burned significantly more calories and reported lower perceived exertion than SIT. The higher VO2 and lower BLa in HIIT vs. SIT reflected dissimilar metabolic perturbation between regimens, which may elicit unique long-term adaptations. If an individual is seeking to burn slightly more calories, maintain a higher oxygen uptake, and perceive less exertion during exercise, HIIT is the recommended routine. PMID:26691413
Volatility return intervals analysis of the Japanese market
NASA Astrophysics Data System (ADS)
Jung, W.-S.; Wang, F. Z.; Havlin, S.; Kaizoji, T.; Moon, H.-T.; Stanley, H. E.
2008-03-01
We investigate scaling and memory effects in return intervals between price volatilities above a certain threshold q for the Japanese stock market using daily and intraday data sets. We find that the distribution of return intervals can be approximated by a scaling function that depends only on the ratio between the return interval τ and its mean <τ>. We also find memory effects such that a large (or small) return interval follows a large (or small) interval by investigating the conditional distribution and mean return interval. The results are similar to previous studies of other markets and indicate that similar statistical features appear in different financial markets. We also compare our results between the period before and after the big crash at the end of 1989. We find that scaling and memory effects of the return intervals show similar features although the statistical properties of the returns are different.
Working memory for time intervals in auditory rhythmic sequences
Teki, Sundeep; Griffiths, Timothy D.
2014-01-01
The brain can hold information about multiple objects in working memory. It is not known, however, whether intervals of time can be stored in memory as distinct items. Here, we developed a novel paradigm to examine temporal memory where listeners were required to reproduce the duration of a single probed interval from a sequence of intervals. We demonstrate that memory performance significantly varies as a function of temporal structure (better memory in regular vs. irregular sequences), interval size (better memory for sub- vs. supra-second intervals), and memory load (poor memory for higher load). In contrast memory performance is invariant to attentional cueing. Our data represent the first systematic investigation of temporal memory in sequences that goes beyond previous work based on single intervals. The results support the emerging hypothesis that time intervals are allocated a working memory resource that varies with the amount of other temporal information in a sequence. PMID:25477849
Hemodynamics of distal revascularization-interval ligation.
Illig, Karl A; Surowiec, Scott; Shortell, Cynthia K; Davies, Mark G; Rhodes, Jeffrey M; Green, Richard M
2005-03-01
Distal revascularization-interval ligation (DRIL) empirically corrects steal after arteriovenous fistula (AVF) creation in most cases, but because there is no topologic alteration in anatomy, it is unclear as to why it is effective. To explore this issue, nine symptomatic patients underwent intravascular pressure and flow measurements before and after DRIL following upper arm autologous AVFs. Mean pre-DRIL systolic pressure (mmHg; mean +/- SD) in the proximal brachial artery (PROX) was 102 +/- 17, while that at the AV anastomosis (AV ANAST) was 47 +/- 38 (p < 0.0006). Flow (mL/min) distal to AV ANAST was retrograde with the fistula open (-21 +/- 64) but became antegrade (58 +/- 29; p < 0.03) with occlusion of the fistula. Following DRIL, pressures at both PROX and AV ANAST sites did not change (104 +/- 24 and 51 +/- 43, respectively). However, pressure at the point at which the blood flow split to supply the hand or the fistula, now PROX, increased from 47 +/- 38 (pre-DRIL AV ANAST) to 104 +/- 24 (p < 0.0001). Pressure in the brachial artery distal to the ligature increased to 104 +/- 27 (p < 0.0001), flow at this point (to the hand) became antegrade (51 +/- 39; p < 0.03), and occlusion of the fistula did not significantly change pressure at this site. We hypothesize that improvement in hand perfusion following DRIL is due to a higher pressure at the point at which the blood flow splits to supply both hand and fistula (pre-DRIL: AV ANAST; post-DRIL: PROX), allowing antegrade flow down the new bypass to the lower pressure forearm. This increased pressure must be due to the increased resistance of the fistula created by interposing the arterial segment between the original AV ANAST and new PROX ANAST. As such, DRIL is schematically equivalent to banding, but resistance is increased in a fashion that is physiologically and empirically acceptable. PMID:15770367
NASA Astrophysics Data System (ADS)
Ulizio, T. P.; Bilbrey, C.; Stoyanoff, N.; Dixon, J. L.
2015-12-01
Mass wasting events are geologic hazards that impact human life and property across a variety of landscapes. These movements can be triggered by tectonic activity, anomalous precipitation events, or both; acting to decrease the factor of safety ratio on a hillslope to the point of failure. There exists an active hazard landscape in the West Boulder River drainage of Park Co., MT in which the mechanisms of slope failure are unknown. It is known that region has not seen significant tectonic activity within the last decade, leaving anomalous precipitation events as the likely trigger for slope failures in the landscape. Precipitation can be delivered to a landscape via rainfall or snow; it was the aim of this study to determine the precipitation delivery mechanism most likely responsible for movements in the West Boulder drainage following the Jungle Wildfire of 2006. Data was compiled from four SNOTEL sites in the surrounding area, spanning 33 years, focusing on, but not limited to; maximum snow water equivalent (SWE) values in a water year, median SWE values on the date which maximum SWE was recorded in a water year, the total precipitation accumulated in a water year, etc. Means were computed and 99% confidence intervals were constructed around these means. Recurrence intervals and exceedance probabilities were computed for maximum SWE values and total precipitation accumulated in a water year to determine water years with anomalous precipitation. It was determined that the water year 2010-2011 received an anomalously high amount of SWE, and snow melt in the spring of this water year likely triggered recent mass waste movements. This data is further supported by Google Earth imagery, showing movements between 2009 and 2011. Return intervals for the maximum SWE value in 2010-11 for the Placer Basin SNOTEL site was 34 years, while return intervals for the Box Canyon and Monument Peak SNOTEL sites were 17.5 and 17 years respectively. Max SWE values lie outside the
Detrended fluctuation analysis of non-stationary cardiac beat-to-beat interval of sick infants
NASA Astrophysics Data System (ADS)
Govindan, Rathinaswamy B.; Massaro, An N.; Al-Shargabi, Tareq; Niforatos Andescavage, Nickie; Chang, Taeun; Glass, Penny; du Plessis, Adre J.
2014-11-01
We performed detrended fluctuation analysis (DFA) of cardiac beat-to-beat intervals (RRis) collected from sick newborn infants over 1-4 day periods. We calculated four different metrics from the DFA fluctuation function: the DFA exponents αL (>40 beats up to one-fourth of the record length), αs (15-30 beats), root-mean-square (RMS) fluctuation on a short-time scale (20-50 beats), and RMS fluctuation on a long-time scale (110-150 beats). Except αL , all metrics clearly distinguished two groups of newborn infants (favourable vs. adverse) with well-characterized outcomes. However, the RMS fluctuations distinguished the two groups more consistently over time compared to αS . Furthermore, RMS distinguished the RRi of the two groups earlier compared to the DFA exponent. In all the three measures, the favourable outcome group displayed higher values, indicating a higher magnitude of (auto-)correlation and variability, thus normal physiology, compared to the adverse outcome group.
Alternative Confidence Interval Methods Used in the Diagnostic Accuracy Studies
Gülhan, Orekıcı Temel
2016-01-01
Background/Aim. It is necessary to decide whether the newly improved methods are better than the standard or reference test or not. To decide whether the new diagnostics test is better than the gold standard test/imperfect standard test, the differences of estimated sensitivity/specificity are calculated with the help of information obtained from samples. However, to generalize this value to the population, it should be given with the confidence intervals. The aim of this study is to evaluate the confidence interval methods developed for the differences between the two dependent sensitivity/specificity values on a clinical application. Materials and Methods. In this study, confidence interval methods like Asymptotic Intervals, Conditional Intervals, Unconditional Interval, Score Intervals, and Nonparametric Methods Based on Relative Effects Intervals are used. Besides, as clinical application, data used in diagnostics study by Dickel et al. (2010) has been taken as a sample. Results. The results belonging to the alternative confidence interval methods for Nickel Sulfate, Potassium Dichromate, and Lanolin Alcohol are given as a table. Conclusion. While preferring the confidence interval methods, the researchers have to consider whether the case to be compared is single ratio or dependent binary ratio differences, the correlation coefficient between the rates in two dependent ratios and the sample sizes. PMID:27478491
Tuning for temporal interval in human apparent motion detection.
Bours, Roger J E; Stuur, Sanne; Lankheet, Martin J M
2007-01-01
Detection of apparent motion in random dot patterns requires correlation across time and space. It has been difficult to study the temporal requirements for the correlation step because motion detection also depends on temporal filtering preceding correlation and on integration at the next levels. To specifically study tuning for temporal interval in the correlation step, we performed an experiment in which prefiltering and postintegration were held constant and in which we used a motion stimulus containing coherent motion for a single interval value only. The stimulus consisted of a sparse random dot pattern in which each dot was presented in two frames only, separated by a specified interval. On each frame, half of the dots were refreshed and the other half was a displaced reincarnation of the pattern generated one or several frames earlier. Motion energy statistics in such a stimulus do not vary from frame to frame, and the directional bias in spatiotemporal correlations is similar for different interval settings. We measured coherence thresholds for left-right direction discrimination by varying motion coherence levels in a Quest staircase procedure, as a function of both step size and interval. Results show that highest sensitivity was found for an interval of 17-42 ms, irrespective of viewing distance. The falloff at longer intervals was much sharper than previously described. Tuning for temporal interval was largely, but not completely, independent of step size. The optimal temporal interval slightly decreased with increasing step size. Similarly, the optimal step size decreased with increasing temporal interval. PMID:17461670
Extended flowering intervals of bamboos evolved by discrete multiplication.
Veller, Carl; Nowak, Martin A; Davis, Charles C
2015-07-01
Numerous bamboo species collectively flower and seed at dramatically extended, regular intervals - some as long as 120 years. These collective seed releases, termed 'masts', are thought to be a strategy to overwhelm seed predators or to maximise pollination rates. But why are the intervals so long, and how did they evolve? We propose a simple mathematical model that supports their evolution as a two-step process: First, an initial phase in which a mostly annually flowering population synchronises onto a small multi-year interval. Second, a phase of successive small multiplications of the initial synchronisation interval, resulting in the extraordinary intervals seen today. A prediction of the hypothesis is that mast intervals observed today should factorise into small prime numbers. Using a historical data set of bamboo flowering observations, we find strong evidence in favour of this prediction. Our hypothesis provides the first theoretical explanation for the mechanism underlying this remarkable phenomenon. PMID:25963600
Interval timing in Siamese fighting fish (Betta splendens).
Higa, J J; Simm, L A
2004-11-30
The present study evaluated the temporal performance of Siamese fighting fish (Betta splendens) given short-term exposure to four fixed interval (FI) schedules of reinforcement, FI 30, 60, 120, and 240 s, during which a reinforcer (mirror image) was given for the first response (swimming through a hoop) after the interval requirement had elapsed. Response levels were generally low early in an interval and increased as the interval elapsed; wait times and break points in an interval increased with increases in the FI requirement. The results were similar to that obtained with other species and different types of responses and reinforcers, and demonstrate that the procedure is a feasible method for studying interval timing in fish. PMID:15518999
IBM system/360 assembly language interval arithmetic software
NASA Technical Reports Server (NTRS)
Phillips, E. J.
1972-01-01
Computer software designed to perform interval arithmetic is described. An interval is defined as the set of all real numbers between two given numbers including or excluding one or both endpoints. Interval arithmetic consists of the various elementary arithmetic operations defined on the set of all intervals, such as interval addition, subtraction, union, etc. One of the main applications of interval arithmetic is in the area of error analysis of computer calculations. For example, it has been used sucessfully to compute bounds on sounding errors in the solution of linear algebraic systems, error bounds in numerical solutions of ordinary differential equations, as well as integral equations and boundary value problems. The described software enables users to implement algorithms of the type described in references efficiently on the IBM 360 system.
The fractional transportation problem with interval demand, supply and costs
NASA Astrophysics Data System (ADS)
Kocken, Hale Gonce; Emiroğlu, İbrahim; Güler, Coşkun; Taşçı, Fatih; Sivri, Mustafa
2013-09-01
The data of real world applications generally cannot be expressed strictly. An efficient way of handling this situation is expressing the data as intervals. Thus this paper focuses on the Interval Fractional Transportation Problem (IFTP) in which all the parameters i.e. cost and preference coefficients of the objective function, supply and demand quantities are expressed as intervals. A Taylor series approach is presented for IFTP by means of the expression of intervals with its left and right limits. Also a numerical example is executed for the linear case to illustrate the procedure.
Interval-valued fuzzy hypergraph and fuzzy partition.
Chen, S M
1997-01-01
This paper extends the work of H. Lee-Kwang and L.M. Lee (1995) to present the concept of the interval-valued fuzzy hypergraph. In the interval-valued fuzzy hypergraph, the concepts of the dual interval-valued fuzzy hypergraph, the crisp-valued alpha-cut hypergraph, and the interval-valued [alpha(1),alpha(2 )]-cut at beta level hypergraph are developed, where alphain [0, 1], 0
Hydrologic studies in wells open through large intervals
Not Available
1992-01-01
This report describes and summarizes activities, data, and preliminary data interpretation from the INEL Oversight Program R D-1 project titled Hydrologic Studies In Wells Open Through Large Intervals.'' The project is designed to use a straddle-packer system to isolate, hydraulically test, and sample specific intervals of monitoring wells that are open (uncased, unscreened) over large intervals of the Snake River Plain aquifer. The objectives of the project are to determine and compare vertical variations in water quality and aquifer properties that have previously only been determined in an integrated fashion over the entire thickness of the open interval of the observation wells.
Antemortem vitreous potassium may strengthen postmortem interval estimates.
Kokavec, Jan; Min, San H; Tan, Mei H; Gilhotra, Jagjit S; Newland, Henry S; Durkin, Shane R; Casson, Robert J
2016-06-01
The purpose of this letter is to highlight that postmortem interval estimates using vitreous potassium concentrations may be further optimised by calibration against antemortem vitreous samples. PMID:27080618
NASA Astrophysics Data System (ADS)
Wang, Lin-Jie; Cheng, Tan; Zhi-Li, Li; Hui-juan, Wang; Wen-juan, Chen; Jianfeng, Zhang; Desheng, Wang; Dongbin, Niu; Qi, Zhao; Chengjia, Yang; Yanqing, Wang
High intensity interval training (HIIT) has been demonstrated to improve performance in a relatively short training period. But the difference between high intensity interval training and moderate intensity interval training (MIIT) in simulated weightlessness still has not been well studied. This study sought to characterize the difference between 6 weeks high intensity interval training and moderate intensity interval training under reduced weight (RW) gait training device and zero-gravity locomotion system (ZLS). Twenty-three subjects (14M/4F, 32.5±4.5 years) volunteered to participate. They were divided into three groups, that were MITT (alternating 2 min at 40% VO _{2} peak and 2 min at 60% VO _{2} peak for 30min, five days per week) RW group (n=8), HITT (alternating 2 min at 40% VO _{2} peak and 2 min at 90% VO _{2} peak for 30min, three days per week) RW group (n=8) and HITT ZLS group (n=7). The Z-axis load used in RW group was 80% body weight (BW) and in ZLS was 100% BW. Cardiopulmonary function was measured before, after 4-week training and after 6-week training. Isokinetic knee extension-flexion test at 60(°) deg/s and 180(°) deg/s were performed before and after the 6-week training, and isometric knee extension-flexion test at 180(°) deg/s was also examined at the same time. It was found that the VO _{2} peaks, metabolic equivalent (MET), Speedmax and respiratory exchange ratio (RER) were significantly increased after 4 and 6-week training in all three groups and no significant group difference were detected. The peak torque at 60(°) deg/s for right knee flexion were significantly increased after 6 week-training in all three groups, and only in HITT RW group the total power at 60(°) deg/s for right knee flexion enhanced. The total power and average power at 60(°) deg/s for right knee extension decreased significantly after 6-week training in all three groups. The peak torque at 60(°) deg/s for right knee extension in MIIT RW group was
Effect of intense interval workouts on running economy using three recovery durations.
Zavorsky, G S; Montgomery, D L; Pearsall, D J
1998-02-01
The purposes of this study were to determine whether running economy (RE) is adversely affected following intense interval bouts of 10 x 400-m running, and whether there is an interaction effect between RE and recovery duration during the workouts. Twelve highly trained male endurance athletes [maximal oxygen consumption; VO2max = 72.5 (4.3) ml x kg(-1) x min(-1) mean (SD)] performed three interval running workouts of 10 x 400 m with a minimum of 4 days between runs. Recovery duration between the repetitions was randomly assigned at 60, 120 or 180 s. The velocity for each 400-m run was determined from a treadmill VO2max test. The average running velocity was 357.9 (9.0) m x min(-1). Following the workout, the rating of perceived exertion (RPE) increased significantly (P < 0.01) as recovery duration between the 400-m repetitions decreased (14.4, 16.1, and 17.7 at 180s, 120s, and 60 s recovery, respectively). Prior to and following each workout, RE was measured at speeds of 200 and 268 m x min(-1). Changes in RE from pre- to post-workout, as well as heart rate (HR) and respiratory exchange ratio (R) were similar for the three recovery conditions. When averaged across conditions, oxygen consumption (VO2) increased significantly (P < 0.01) from pre- to post-test [from 38.5 to 40.5 ml x kg(-1) x min(-1) at 200 m x min(-1), and from 53.1 to 54.5 ml x kg(-1) x min(-1) at 268 m x min(-1), respectively]. HR increased (from 124 to 138, and from 151 to 157 beats x min(-1) respectively) and R decreased (from 0.90 to 0.78, and from 0.93 to 0.89, respectively) at 200 and 268 m x min(-1), respectively (P < 0.01). This study showed that RE can be perturbed after a high-intensity interval workout and that the changes in VO2, HR and R were independent of the recovery duration between the repetitions. PMID:9535583
Comparing interval estimates for small sample ordinal CFA models.
Natesan, Prathiba
2015-01-01
Robust maximum likelihood (RML) and asymptotically generalized least squares (AGLS) methods have been recommended for fitting ordinal structural equation models. Studies show that some of these methods underestimate standard errors. However, these studies have not investigated the coverage and bias of interval estimates. An estimate with a reasonable standard error could still be severely biased. This can only be known by systematically investigating the interval estimates. The present study compares Bayesian, RML, and AGLS interval estimates of factor correlations in ordinal confirmatory factor analysis models (CFA) for small sample data. Six sample sizes, 3 factor correlations, and 2 factor score distributions (multivariate normal and multivariate mildly skewed) were studied. Two Bayesian prior specifications, informative and relatively less informative were studied. Undercoverage of confidence intervals and underestimation of standard errors was common in non-Bayesian methods. Underestimated standard errors may lead to inflated Type-I error rates. Non-Bayesian intervals were more positive biased than negatively biased, that is, most intervals that did not contain the true value were greater than the true value. Some non-Bayesian methods had non-converging and inadmissible solutions for small samples and non-normal data. Bayesian empirical standard error estimates for informative and relatively less informative priors were closer to the average standard errors of the estimates. The coverage of Bayesian credibility intervals was closer to what was expected with overcoverage in a few cases. Although some Bayesian credibility intervals were wider, they reflected the nature of statistical uncertainty that comes with the data (e.g., small sample). Bayesian point estimates were also more accurate than non-Bayesian estimates. The results illustrate the importance of analyzing coverage and bias of interval estimates, and how ignoring interval estimates can be misleading
Comparing interval estimates for small sample ordinal CFA models
Natesan, Prathiba
2015-01-01
Robust maximum likelihood (RML) and asymptotically generalized least squares (AGLS) methods have been recommended for fitting ordinal structural equation models. Studies show that some of these methods underestimate standard errors. However, these studies have not investigated the coverage and bias of interval estimates. An estimate with a reasonable standard error could still be severely biased. This can only be known by systematically investigating the interval estimates. The present study compares Bayesian, RML, and AGLS interval estimates of factor correlations in ordinal confirmatory factor analysis models (CFA) for small sample data. Six sample sizes, 3 factor correlations, and 2 factor score distributions (multivariate normal and multivariate mildly skewed) were studied. Two Bayesian prior specifications, informative and relatively less informative were studied. Undercoverage of confidence intervals and underestimation of standard errors was common in non-Bayesian methods. Underestimated standard errors may lead to inflated Type-I error rates. Non-Bayesian intervals were more positive biased than negatively biased, that is, most intervals that did not contain the true value were greater than the true value. Some non-Bayesian methods had non-converging and inadmissible solutions for small samples and non-normal data. Bayesian empirical standard error estimates for informative and relatively less informative priors were closer to the average standard errors of the estimates. The coverage of Bayesian credibility intervals was closer to what was expected with overcoverage in a few cases. Although some Bayesian credibility intervals were wider, they reflected the nature of statistical uncertainty that comes with the data (e.g., small sample). Bayesian point estimates were also more accurate than non-Bayesian estimates. The results illustrate the importance of analyzing coverage and bias of interval estimates, and how ignoring interval estimates can be misleading
Vincent, Grace; Lamon, Séverine; Gant, Nicholas; Vincent, Peter J.; MacDonald, Julia R.; Markworth, James F.; Edge, Johann A.; Hickey, Anthony J. R.
2015-01-01
Purpose: High-intensity short-duration interval training (HIT) stimulates functional and metabolic adaptation in skeletal muscle, but the influence of HIT on mitochondrial function remains poorly studied in humans. Mitochondrial metabolism as well as mitochondrial-associated protein expression were tested in untrained participants performing HIT over a 2-week period. Methods: Eight males performed a single-leg cycling protocol (12 × 1 min intervals at 120% peak power output, 90 s recovery, 4 days/week). Muscle biopsies (vastus lateralis) were taken pre- and post-HIT. Mitochondrial respiration in permeabilized fibers, citrate synthase (CS) activity and protein expression of peroxisome proliferator-activated receptor gamma coactivator (PGC-1α) and respiratory complex components were measured. Results: HIT training improved peak power and time to fatigue. Increases in absolute oxidative phosphorylation (OXPHOS) capacities and CS activity were observed, but not in the ratio of CCO to the electron transport system (CCO/ETS), the respiratory control ratios (RCR-1 and RCR-2) or mitochondrial-associated protein expression. Specific increases in OXPHOS flux were not apparent after normalization to CS, indicating that gross changes mainly resulted from increased mitochondrial mass. Conclusion: Over only 2 weeks HIT significantly increased mitochondrial function in skeletal muscle independently of detectable changes in mitochondrial-associated and mitogenic protein expression. PMID:25759671
A comparison of approximate interval estimators for the Bernoulli parameter
NASA Technical Reports Server (NTRS)
Leemis, Lawrence; Trivedi, Kishor S.
1993-01-01
The goal of this paper is to compare the accuracy of two approximate confidence interval estimators for the Bernoulli parameter p. The approximate confidence intervals are based on the normal and Poisson approximations to the binomial distribution. Charts are given to indicate which approximation is appropriate for certain sample sizes and point estimators.
Reporting Confidence Intervals and Effect Sizes: Collecting the Evidence
ERIC Educational Resources Information Center
Zientek, Linda Reichwein; Ozel, Z. Ebrar Yetkiner; Ozel, Serkan; Allen, Jeff
2012-01-01
Confidence intervals (CIs) and effect sizes are essential to encourage meta-analytic thinking and to accumulate research findings. CIs provide a range of plausible values for population parameters with a degree of confidence that the parameter is in that particular interval. CIs also give information about how precise the estimates are. Comparison…
Sample Size for the "Z" Test and Its Confidence Interval
ERIC Educational Resources Information Center
Liu, Xiaofeng Steven
2012-01-01
The statistical power of a significance test is closely related to the length of the confidence interval (i.e. estimate precision). In the case of a "Z" test, the length of the confidence interval can be expressed as a function of the statistical power. (Contains 1 figure and 1 table.)
Magnitude Estimation Reveals Temporal Binding at Super-Second Intervals
ERIC Educational Resources Information Center
Humphreys, Gruffydd R.; Buehner, Marc J.
2009-01-01
Several recent studies (e.g., Haggard, Aschersleben, Gehrke, & Prinz, 2002; Haggard & Clark, 2003; Haggard, Clark, & Kalogeras, 2002) have demonstrated a "Temporal Binding" effect in which the interval between an intentional action and its consequent outcome is subjectively shorter compared to equivalent intervals that do not involve intentional…
30 CFR 75.360 - Preshift examination at fixed intervals.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Preshift examination at fixed intervals. 75.360 Section 75.360 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.360 Preshift examination at fixed intervals. (a)(1) Except...
Interval Estimation of Gamma for an "RxS" Table
ERIC Educational Resources Information Center
Lui, Kung-Jong; Cumberland, William G.
2004-01-01
When the underlying responses are on an ordinal scale, gamma is one of the most frequently used indices to measure the strength of association between two ordered variables. However, except for a brief mention on the use of the traditional interval estimator based on Wald's statistic, discussion of interval estimation of the gamma is limited.…
Overconfidence in Interval Estimates: What Does Expertise Buy You?
ERIC Educational Resources Information Center
McKenzie, Craig R. M.; Liersch, Michael J.; Yaniv, Ilan
2008-01-01
People's 90% subjective confidence intervals typically contain the true value about 50% of the time, indicating extreme overconfidence. Previous results have been mixed regarding whether experts are as overconfident as novices. Experiment 1 examined interval estimates from information technology (IT) professionals and UC San Diego (UCSD) students…
Bootstrapping Confidence Intervals for Robust Measures of Association.
ERIC Educational Resources Information Center
King, Jason E.
A Monte Carlo simulation study was conducted to determine the bootstrap correction formula yielding the most accurate confidence intervals for robust measures of association. Confidence intervals were generated via the percentile, adjusted, BC, and BC(a) bootstrap procedures and applied to the Winsorized, percentage bend, and Pearson correlation…
Why Aren't They Called Probability Intervals?
ERIC Educational Resources Information Center
Devlin, Thomas F.
2008-01-01
This article offers suggestions for teaching confidence intervals, a fundamental statistical tool often misinterpreted by beginning students. A historical perspective presenting the interpretation given by their inventor is supported with examples and the use of technology. A method for determining confidence intervals for the seldom-discussed…
Confidence Intervals for Effect Sizes: Applying Bootstrap Resampling
ERIC Educational Resources Information Center
Banjanovic, Erin S.; Osborne, Jason W.
2016-01-01
Confidence intervals for effect sizes (CIES) provide readers with an estimate of the strength of a reported statistic as well as the relative precision of the point estimate. These statistics offer more information and context than null hypothesis statistic testing. Although confidence intervals have been recommended by scholars for many years,…
Improved central confidence intervals for the ratio of Poisson means
NASA Astrophysics Data System (ADS)
Cousins, R. D.
The problem of confidence intervals for the ratio of two unknown Poisson means was "solved" decades ago, but a closer examination reveals that the standard solution is far from optimal from the frequentist point of view. We construct a more powerful set of central confidence intervals, each of which is a (typically proper) subinterval of the corresponding standard interval. They also provide upper and lower confidence limits which are more restrictive than the standard limits. The construction follows Neyman's original prescription, though discreteness of the Poisson distribution and the presence of a nuisance parameter (one of the unknown means) lead to slightly conservative intervals. Philosophically, the issue of the appropriateness of the construction method is similar to the issue of conditioning on the margins in 2×2 contingency tables. From a frequentist point of view, the new set maintains (over) coverage of the unknown true value of the ratio of means at each stated confidence level, even though the new intervals are shorter than the old intervals by any measure (except for two cases where they are identical). As an example, when the number 2 is drawn from each Poisson population, the 90% CL central confidence interval on the ratio of means is (0.169, 5.196), rather than (0.108, 9.245). In the cited literature, such confidence intervals have applications in numerous branches of pure and applied science, including agriculture, wildlife studies, manufacturing, medicine, reliability theory, and elementary particle physics.
Overestimation-free Computational Version of Interval Analysis
NASA Astrophysics Data System (ADS)
Elishakoff, Isaac; Miglis, Yohann
2012-08-01
In this study we propose a new version of interval analysis that is free of its main disadvantage, namely the overestimation. Interval variables are transformed into trigonometric functions with attendant analytical or numerical evaluation of extrema. Several examples are evaluated to shed light on the efficacy of the proposed methodology.
A Note on Confidence Interval Estimation and Margin of Error
ERIC Educational Resources Information Center
Gilliland, Dennis; Melfi, Vince
2010-01-01
Confidence interval estimation is a fundamental technique in statistical inference. Margin of error is used to delimit the error in estimation. Dispelling misinterpretations that teachers and students give to these terms is important. In this note, we give examples of the confusion that can arise in regard to confidence interval estimation and…
Plea for routinely presenting prediction intervals in meta-analysis
IntHout, Joanna; Ioannidis, John P A; Rovers, Maroeska M; Goeman, Jelle J
2016-01-01
Objectives Evaluating the variation in the strength of the effect across studies is a key feature of meta-analyses. This variability is reflected by measures like τ2 or I2, but their clinical interpretation is not straightforward. A prediction interval is less complicated: it presents the expected range of true effects in similar studies. We aimed to show the advantages of having the prediction interval routinely reported in meta-analyses. Design We show how the prediction interval can help understand the uncertainty about whether an intervention works or not. To evaluate the implications of using this interval to interpret the results, we selected the first meta-analysis per intervention review of the Cochrane Database of Systematic Reviews Issues 2009–2013 with a dichotomous (n=2009) or continuous (n=1254) outcome, and generated 95% prediction intervals for them. Results In 72.4% of 479 statistically significant (random-effects p<0.05) meta-analyses in the Cochrane Database 2009–2013 with heterogeneity (I2>0), the 95% prediction interval suggested that the intervention effect could be null or even be in the opposite direction. In 20.3% of those 479 meta-analyses, the prediction interval showed that the effect could be completely opposite to the point estimate of the meta-analysis. We demonstrate also how the prediction interval can be used to calculate the probability that a new trial will show a negative effect and to improve the calculations of the power of a new trial. Conclusions The prediction interval reflects the variation in treatment effects over different settings, including what effect is to be expected in future patients, such as the patients that a clinician is interested to treat. Prediction intervals should be routinely reported to allow more informative inferences in meta-analyses. PMID:27406637
Complete Blood Count Reference Intervals for Healthy Han Chinese Adults
Mu, Runqing; Guo, Wei; Qiao, Rui; Chen, Wenxiang; Jiang, Hong; Ma, Yueyun; Shang, Hong
2015-01-01
Background Complete blood count (CBC) reference intervals are important to diagnose diseases, screen blood donors, and assess overall health. However, current reference intervals established by older instruments and technologies and those from American and European populations are not suitable for Chinese samples due to ethnic, dietary, and lifestyle differences. The aim of this multicenter collaborative study was to establish CBC reference intervals for healthy Han Chinese adults. Methods A total of 4,642 healthy individuals (2,136 males and 2,506 females) were recruited from six clinical centers in China (Shenyang, Beijing, Shanghai, Guangzhou, Chengdu, and Xi’an). Blood samples collected in K2EDTA anticoagulant tubes were analyzed. Analysis of variance was performed to determine differences in consensus intervals according to the use of data from the combined sample and selected samples. Results Median and mean platelet counts from the Chengdu center were significantly lower than those from other centers. Red blood cell count (RBC), hemoglobin (HGB), and hematocrit (HCT) values were higher in males than in females at all ages. Other CBC parameters showed no significant instrument-, region-, age-, or sex-dependent difference. Thalassemia carriers were found to affect the lower or upper limit of different RBC profiles. Conclusion We were able to establish consensus intervals for CBC parameters in healthy Han Chinese adults. RBC, HGB, and HCT intervals were established for each sex. The reference interval for platelets for the Chengdu center should be established independently. PMID:25769040
Modelling volatility recurrence intervals in the Chinese commodity futures market
NASA Astrophysics Data System (ADS)
Zhou, Weijie; Wang, Zhengxin; Guo, Haiming
2016-09-01
The law of extreme event occurrence attracts much research. The volatility recurrence intervals of Chinese commodity futures market prices are studied: the results show that the probability distributions of the scaled volatility recurrence intervals have a uniform scaling curve for different thresholds q. So we can deduce the probability distribution of extreme events from normal events. The tail of a scaling curve can be well fitted by a Weibull form, which is significance-tested by KS measures. Both short-term and long-term memories are present in the recurrence intervals with different thresholds q, which denotes that the recurrence intervals can be predicted. In addition, similar to volatility, volatility recurrence intervals also have clustering features. Through Monte Carlo simulation, we artificially synthesise ARMA, GARCH-class sequences similar to the original data, and find out the reason behind the clustering. The larger the parameter d of the FIGARCH model, the stronger the clustering effect is. Finally, we use the Fractionally Integrated Autoregressive Conditional Duration model (FIACD) to analyse the recurrence interval characteristics. The results indicated that the FIACD model may provide a method to analyse volatility recurrence intervals.
Drug discrimination under two concurrent fixed-interval fixed-interval schedules.
McMillan, D E; Li, M
2000-01-01
Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a two-key concurrent fixed-interval (FI) 100-s FI 200-s schedule of food presentation, and later tinder a concurrent FI 40-s FI 80-s schedule, in which the FI component with the shorter time requirement reinforced responding on one key after drug administration (pentobarbital-biased key) and on the other key after saline administration (saline-biased key). After responding stabilized under the concurrent FI 100-s FI 200-s schedule, pigeons earned an average of 66% (after pentobarbital) to 68% (after saline) of their reinforcers for responding under the FI 100-s component of the concurrent schedule. These birds made an average of 70% of their responses on both the pentobarbital-biased key after the training dose of pentobarbital and the saline-biased key after saline. After responding stabilized under the concurrent FI 40-s FI 80-s schedule, pigeons earned an average of 67% of their reinforcers for responding under the FI 40 component after both saline and the training dose of pentobarbital. These birds made an average of 75% of their responses on the pentobarbital-biased key after the training dose of pentobarbital, but only 55% of their responses on the saline-biased key after saline. In test sessions preceded by doses of pentobarbital, chlordiazepoxide, ethanol, phencyclidine, or methamphetamine, the dose-response curves were similar under these two concurrent schedules. Pentobarbital, chlordiazepoxide, and ethanol produced dose-dependent increases in responding on the pentobarbital-biased key as the doses increased. For some birds, at the highest doses of these drugs, the dose-response curve turned over. Increasing doses of phencyclidine produced increased responding on the pentobarbital-biased key in some, but not all, birds. After methamphetamine, responding was largely confined to the saline-biased key. These data show that pigeons can perform drug discriminations under concurrent
Drug discrimination under two concurrent fixed-interval fixed-interval schedules.
McMillan, D E; Li, M
2000-07-01
Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a two-key concurrent fixed-interval (FI) 100-s FI 200-s schedule of food presentation, and later tinder a concurrent FI 40-s FI 80-s schedule, in which the FI component with the shorter time requirement reinforced responding on one key after drug administration (pentobarbital-biased key) and on the other key after saline administration (saline-biased key). After responding stabilized under the concurrent FI 100-s FI 200-s schedule, pigeons earned an average of 66% (after pentobarbital) to 68% (after saline) of their reinforcers for responding under the FI 100-s component of the concurrent schedule. These birds made an average of 70% of their responses on both the pentobarbital-biased key after the training dose of pentobarbital and the saline-biased key after saline. After responding stabilized under the concurrent FI 40-s FI 80-s schedule, pigeons earned an average of 67% of their reinforcers for responding under the FI 40 component after both saline and the training dose of pentobarbital. These birds made an average of 75% of their responses on the pentobarbital-biased key after the training dose of pentobarbital, but only 55% of their responses on the saline-biased key after saline. In test sessions preceded by doses of pentobarbital, chlordiazepoxide, ethanol, phencyclidine, or methamphetamine, the dose-response curves were similar under these two concurrent schedules. Pentobarbital, chlordiazepoxide, and ethanol produced dose-dependent increases in responding on the pentobarbital-biased key as the doses increased. For some birds, at the highest doses of these drugs, the dose-response curve turned over. Increasing doses of phencyclidine produced increased responding on the pentobarbital-biased key in some, but not all, birds. After methamphetamine, responding was largely confined to the saline-biased key. These data show that pigeons can perform drug discriminations under concurrent
The Role of Higher Harmonics In Musical Interval Perception
NASA Astrophysics Data System (ADS)
Krantz, Richard; Douthett, Jack
2011-10-01
Using an alternative parameterization of the roughness curve we make direct use of critical band results to investigate the role of higher harmonics on the perception of tonal consonance. We scale the spectral amplitudes in the complex home tone and complex interval tone to simulate acoustic signals of constant energy. Our analysis reveals that even with a relatively small addition of higher harmonics the perfect fifth emerges as a consonant interval with more, musically important, just intervals emerging as consonant as more and more energy is shifted into higher frequencies.
Detectability of auditory signals presented without defined observation intervals
NASA Technical Reports Server (NTRS)
Watson, C. S.; Nichols, T. L.
1976-01-01
Ability to detect tones in noise was measured without defined observation intervals. Latency density functions were estimated for the first response following a signal and, separately, for the first response following randomly distributed instances of background noise. Detection performance was measured by the maximum separation between the cumulative latency density functions for signal-plus-noise and for noise alone. Values of the index of detectability, estimated by this procedure, were approximately those obtained with a 2-dB weaker signal and defined observation intervals. Simulation of defined- and non-defined-interval tasks with an energy detector showed that this device performs very similarly to the human listener in both cases.
Concept of Operations for Interval Management Arrivals and Approach
NASA Technical Reports Server (NTRS)
Hicok, Daniel S.; Barmore, Bryan E.
2016-01-01
This paper presents the concept of operations for interval management operations to be deployed in the US National Airspace System (NAS) by the Federal Aviation Administration (FAA) after 2020. The use of interval management operations is described that begin in en route airspace and continue to a termination point inside the arrival terminal area, in a terminal environment that includes other arrival management tools such as arrival metering, Ground-based Interval Management - Spacing (GIM-S), and Terminal Sequencing and Spacing (TSAS). The roles of Air Traffic Controllers and Flight Crews and the ground automation tools that are used by Air Traffic Controllers to enable the primary operation and variations are described.
Estimation of confidence intervals for federal waterfowl harvest surveys
Geissler, P.H.
1990-01-01
I developed methods of estimating confidence intervals for the federal waterfowl harvest surveys conducted by the U.S. Fish and Wildlife Service (USFWS). I estimated flyway harvest confidence intervals for mallards (Anas platyrhynchos) (95% CI are .+-. 8% of the estimate). Canada geese (Branta canadensis) (.+-. 11%), black ducks (Anas rubripes) (.+-. 16%), canvasbacks (Aythya valisineria) (.+-. 32%), snow geese (Chen caerulescens) (.+-. 43%), and brant (Branta bernicla) (.+-. 46%). Differences between annual estimate of 10, 13, 22, 42, 43, and 58% could be detected with mallards, Canada geese, black ducks, canvasbacks, snow geese, and brant, respectively. Estimated confidence intervals for state harvests tended to be much larger than those for the flyway estimates.
Drug discrimination under a concurrent fixed-interval fixed-interval schedule.
McMillan, D E; Li, M; Hardwick, W C
1997-01-01
Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a concurrent fixed-interval (FI) FI schedule of food presentation on which, after pentobarbital administration, responses on one key were reinforced with food under an FI 60-s component and responses on the other key were reinforced under an FI 240-s component. After saline administration, the schedule contingencies on the two keys were reversed. After both pentobarbital and saline, pigeons responded more frequently on the key on which responses had been programmed to produce the reinforcer under the FI 60 component of the concurrent schedule. The schedule was changed to concurrent FI 150 FI 150 s for drug-substitution tests. In each bird, increasing doses of pentobarbital, ethanol, and chlordiazepoxide produced increases in the proportion of responses on the key on which responses had been reinforced under the FI 60 component after pentobarbital administration during training sessions. The proportion of responses on that key was slightly lower for ethanol than for chlordiazepoxide and pentobarbital. At a dose of pentobarbital higher than the training dose, responding decreased on the key that had been reinforced under the FI 60 component during training sessions. Phencyclidine produced less responding on the key programmed under the FI 60-s component than did pentobarbital. Methamphetamine produced responding primarily on the key on which responses had been reinforced under the FI 60-s component after saline administration. PMID:9335138
The 32nd CDC: System identification using interval dynamic models
NASA Technical Reports Server (NTRS)
Keel, L. H.; Lew, J. S.; Bhattacharyya, S. P.
1992-01-01
Motivated by the recent explosive development of results in the area of parametric robust control, a new technique to identify a family of uncertain systems is identified. The new technique takes the frequency domain input and output data obtained from experimental test signals and produces an 'interval transfer function' that contains the complete frequency domain behavior with respect to the test signals. This interval transfer function is one of the key concepts in the parametric robust control approach and identification with such an interval model allows one to predict the worst case performance and stability margins using recent results on interval systems. The algorithm is illustrated by applying it to an 18 bay Mini-Mast truss structure.
Concept of Operations for Interval Management Arrivals and Approach
NASA Technical Reports Server (NTRS)
Hicok, Daniel S.; Barmore, Bryan E.
2016-01-01
This paper presents the concept of operations for interval management operations to be deployed in the US National Airspace System (NAS) by the Federal Aviation Administration (FAA) Interval Management Program. The arrivals and approach operations are explored in detail including the primary operation and variations. The use of interval management operations is described that begin in en route airspace and continue to a termination point inside the arrival terminal area in the highly automated terminal environment that includes other arrival management tools such as arrival metering, Ground-based Interval Management - Spacing (GIM-S), and Terminal Sequencing and Spacing (TSAS). The roles of Air Traffic and Pilots and the ground automation tools that are used by Air Traffic Controllers to enable the operations are explored.
Baseline Bone Mineral Density Measurements Key to Future Testing Intervals
... on Research 2012 May 2012 (historical) Baseline Bone Mineral Density Measurements Key to Future Testing Intervals How often a woman should have bone mineral density (BMD) tests to track bone mass is ...
Experimental uncertainty estimation and statistics for data having interval uncertainty.
Kreinovich, Vladik (Applied Biomathematics, Setauket, New York); Oberkampf, William Louis (Applied Biomathematics, Setauket, New York); Ginzburg, Lev (Applied Biomathematics, Setauket, New York); Ferson, Scott (Applied Biomathematics, Setauket, New York); Hajagos, Janos (Applied Biomathematics, Setauket, New York)
2007-05-01
This report addresses the characterization of measurements that include epistemic uncertainties in the form of intervals. It reviews the application of basic descriptive statistics to data sets which contain intervals rather than exclusively point estimates. It describes algorithms to compute various means, the median and other percentiles, variance, interquartile range, moments, confidence limits, and other important statistics and summarizes the computability of these statistics as a function of sample size and characteristics of the intervals in the data (degree of overlap, size and regularity of widths, etc.). It also reviews the prospects for analyzing such data sets with the methods of inferential statistics such as outlier detection and regressions. The report explores the tradeoff between measurement precision and sample size in statistical results that are sensitive to both. It also argues that an approach based on interval statistics could be a reasonable alternative to current standard methods for evaluating, expressing and propagating measurement uncertainties.
A new interval optimization method considering tolerance design
NASA Astrophysics Data System (ADS)
Jiang, C.; Xie, H. C.; Zhang, Z. G.; Han, X.
2015-12-01
This study considers the design variable uncertainty in the actual manufacturing process for a product or structure and proposes a new interval optimization method based on tolerance design, which can provide not only an optimal design but also the allowable maximal manufacturing errors that the design can bear. The design variables' manufacturing errors are depicted using the interval method, and an interval optimization model for the structure is constructed. A dimensionless design tolerance index is defined to describe the overall uncertainty of all design variables, and by combining the nominal objective function, a deterministic two-objective optimization model is built. The possibility degree of interval is used to represent the reliability of the constraints under uncertainty, through which the model is transformed to a deterministic optimization problem. Three numerical examples are investigated to verify the effectiveness of the present method.
Utility of Corrected QT Interval in Orthostatic Intolerance
Kim, Jung Bin; Hong, Soonwoong; Park, Jin-Woo; Cho, Dong-Hyuk; Park, Ki-Jong; Kim, Byung-Jo
2014-01-01
We performed this study to determine whether electrocardiographic corrected QT (QTc) interval predicts alterations in sympathovagal balance during orthostatic intolerance (OI). We reviewed 1,368 patients presenting with symptoms suggestive of OI who underwent electrocardiography and composite autonomic function tests (AFTs). Patients with a positive response to the head-up tilt test were classified into orthostatic hypotension (OH), neurocardiogenic syncope (NCS), or postural orthostatic tachycardia syndrome (POTS) groups. A total of 275 patients (159 OH, 54 NCS, and 62 POTS) were included in the final analysis. Between-group comparisons of OI symptom grade, QTc interval, QTc dispersion, and each AFT measure were performed. QTc interval and dispersion were correlated with AFT measures. OH Patients had the most severe OI symptom grade and NCS patients the mildest. Patients with OH showed the longest QTc interval (448.8±33.6 msec), QTc dispersion (59.5±30.3 msec) and the lowest values in heart rate response to deep breathing (HRDB) (10.3±6.0 beats/min) and Valsalva ratio (1.3±0.2). Patients with POTS showed the shortest QTc interval (421.7±28.6 msec), the highest HRDB values (24.5±9.2 beats/min), Valsalva ratio (1.8±0.3), and proximal and distal leg sweat volumes in the quantitative sudomotor axon reflex test. QTc interval correlated negatively with HRDB (r = −0.443, p<0.001) and Valsalva ratio (r = −0.425, p<0.001). We found negative correlations between QTc interval and AFT values representing cardiovagal function in patients with OI. Our findings suggest that prolonged QTc interval may be considered to be a biomarker for detecting alterations in sympathovagal balance, especially cardiovagal dysfunction in OH. PMID:25180969
Antipsychotic Polypharmacy and Corrected QT Interval: A Systematic Review
Takeuchi, Hiroyoshi; Suzuki, Takefumi; Remington, Gary; Uchida, Hiroyuki
2015-01-01
Objective: It remains unclear whether antipsychotic polypharmacy, a common clinical practice, is related to an increased risk of corrected time between start of Q wave and end of T wave (QTc) interval prolongation. We conducted a systematic review of the literature to address this important issue. Method: A systematic literature search was conducted in October 2014, using MEDLINE, Embase, and PsycINFO. Studies and case reports were included if they reported QTc intervals or QTc interval changes before and after antipsychotic polypharmacy or QTc intervals in both antipsychotic polypharmacy and monotherapy groups. Results: A total of 21 articles (10 clinical trials, 4 observational studies, and 7 case reports) met inclusion criteria. The clinical trials have shown that a combination treatment with risperidone or pimozide is not obviously related to an increase in QTc interval, whereas ziprasidone or sertindole combined with clozapine may prolong QTc interval. Among the 4 observational studies, antipsychotic polypharmacy was not clearly associated with QTc prolongation in 3 studies, each cross-sectional. In contrast, one prospective study showed a significant increase in QTc interval following antipsychotic coadministration. The case reports indicated an increased risk of QTc prolongation in at least some patients receiving antipsychotic polypharmacy. Conclusions: Currently available evidence fails to confirm that antipsychotic polypharmacy worsens QTc prolongation in general, although the evidence is scarce and inconsistent. Clinicians are advised to remain conservative in resorting to antipsychotic polypharmacy, as a combination of some QTc-prolongation liable antipsychotics may further prolong QTc interval, and efficacy supporting the clinical benefits of antipsychotic polypharmacy is equivocal, at best. PMID:26174525
Establishment of reference intervals and transfusion criterion for Sonoclot analysis.
Zhang, Zhen-Lu; Chen, You-Ping; Tao, Cui-Hua; Liu, Xiao-Hui; Li, Meng-Ya; Zhou, Xin
2016-08-01
Sonoclot analyzer has been widely used in many countries. But the reference intervals provided by the manufacturer were derived from only 45 participants, and there was no cut-off value for transfusion for Sonoclot analysis. This study aimed to establish reference intervals and transfusion criterion for Sonoclot analysis. Volunteers were recruited from healthy Chinese adults and patients undergoing cardiac surgery. Blood samples were withdrawn from forearm vein and measured for activated clotting time (ACT), clot rate (CR), platelet function (PF), activated partial thromboplastin time (APTT), fibrinogen concentration (FIB), and platelet count (PLT). The reference intervals were determined by the nonparametric method. Cut-off values were determined by the receiver operating characteristics curve. A total of 135 healthy volunteers and 281 patients were enrolled. The 95% reference intervals were 96-195 s, 22-51 signal U/min, >1.6 for ACT, CR, PF respectively. In the 281 patients, the results of APTT, FIB, PLT, ACT, CR, and PF ranged from 20.5-300.0 s, 0.28-4.11 g/L, (19.0-387.3)×109/L, 80-514 s, 2.9-74 signal U/min, and 0.1-5.1 respectively. The cut-off values for transfusion were >208, ≤14, and ≤1.3 for ACT, CR, PF respectively. The cut-off values of Sonoclot analysis were within the manufacturer's reference intervals, while they were outside the reference intervals established in this study. The results suggested that the manufacturer's reference intervals were not suitable for Chinese. The reference intervals and cut-off values established in this study will be helpful to Chinese patients. PMID:27465342
Military Applicability of Interval Training for Health and Performance.
Gibala, Martin J; Gagnon, Patrick J; Nindl, Bradley C
2015-11-01
Militaries from around the globe have predominantly used endurance training as their primary mode of aerobic physical conditioning, with historical emphasis placed on the long distance run. In contrast to this traditional exercise approach to training, interval training is characterized by brief, intermittent bouts of intense exercise, separated by periods of lower intensity exercise or rest for recovery. Although hardly a novel concept, research over the past decade has shed new light on the potency of interval training to elicit physiological adaptations in a time-efficient manner. This work has largely focused on the benefits of low-volume interval training, which involves a relatively small total amount of exercise, as compared with the traditional high-volume approach to training historically favored by militaries. Studies that have directly compared interval and moderate-intensity continuous training have shown similar improvements in cardiorespiratory fitness and the capacity for aerobic energy metabolism, despite large differences in total exercise and training time commitment. Interval training can also be applied in a calisthenics manner to improve cardiorespiratory fitness and strength, and this approach could easily be incorporated into a military conditioning environment. Although interval training can elicit physiological changes in men and women, the potential for sex-specific adaptations in the adaptive response to interval training warrants further investigation. Additional work is needed to clarify adaptations occurring over the longer term; however, interval training deserves consideration from a military applicability standpoint as a time-efficient training strategy to enhance soldier health and performance. There is value for military leaders in identifying strategies that reduce the time required for exercise, but nonetheless provide an effective training stimulus. PMID:26506197
Measurement and interpretation of electrocardiographic QT intervals in murine hearts.
Zhang, Yanmin; Wu, JingJing; King, James H; Huang, Christopher L-H; Fraser, James A
2014-06-01
Alterations in ECG QT intervals correlate with the risk of potentially fatal arrhythmias, for which transgenic murine hearts are becoming increasingly useful experimental models. However, QT intervals are poorly defined in murine ECGs. As a consequence, several different techniques have been used to measure murine QT intervals. The present work develops a consistent measure of the murine QT interval that correlates with changes in the duration of ventricular myocyte action potentials (APs). Volume-conducted ECGs were compared with simultaneously recorded APs, obtained using floating intracellular microelectrodes in Langendorff-perfused mouse hearts. QT intervals were measured from the onset of the QRS complex. The interval, Q-APR90, measured to the time at 90% AP recovery, was compared with two measures of the QT interval. QT1 was measured to the recovery of the ECG trace to the isoelectric baseline for entirely positive T-waves or to the trough of any negative T-wave undershoot. QT2-used extensively in previous studies-was measured to the return of any ECG trough to the isoelectric baseline. QT1, but not QT2, closely correlated with changes in Q-APR90. These findings were confirmed over a range of pacing rates, in low K(+) concentration solutions, and in Scn5a+/ΔKPQ hearts used to model human long QT syndrome. Application of this method in whole anesthetized mice similarly demonstrated a prolonged corrected QT (QTc) in Scn5a+/ΔKPQ hearts. We therefore describe a robust method for the determination of QT and QTc intervals that correlate with the duration of ventricular myocyte APs in murine hearts. PMID:24705556
Interval estimation for mark-recapture studies of closed populations.
Cormack, R M
1992-06-01
Textbooks continue to recommend the use of an asymptotic normal distribution to provide an interval estimate for the unknown size, N, of a closed population studied by a mark-recapture experiment or multiple-record system. A likelihood interval approach is proposed and its implementation demonstrated for a range of models for such studies, including all main effect and interaction models for incomplete contingency tables. PMID:1637979
Procrastination by pigeons with fixed-interval response requirements.
Mazur, J E
1998-03-01
Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230
Procrastination by pigeons with fixed-interval response requirements.
Mazur, J E
1998-01-01
Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230
Confidence Intervals for Error Rates Observed in Coded Communications Systems
NASA Astrophysics Data System (ADS)
Hamkins, J.
2015-05-01
We present methods to compute confidence intervals for the codeword error rate (CWER) and bit error rate (BER) of a coded communications link. We review several methods to compute exact and approximate confidence intervals for the CWER, and specifically consider the situation in which the true CWER is so low that only a handful, if any, codeword errors are able to be simulated. In doing so, we answer the question of how long an error-free simulation must be run in order to certify that a given CWER requirement is met with a given level of confidence, and discuss the bias introduced by aborting a simulation after observing the first codeword error. Next, we turn to the lesser studied problem of determining confidence intervals for the BER of coded systems. Since bit errors in systems that use coding or higher-order modulation do not occur independently, blind application of a method that assumes independence leads to inappropriately narrow confidence intervals. We present a new method to compute the confidence interval properly, using the first and second sample moments of the number of bit errors per codeword. This is the first method we know of to compute a confidence interval for the BER of a coded or higher-order modulation system.
Scaling and memory in volatility return intervals in financial markets
Yamasaki, Kazuko; Muchnik, Lev; Havlin, Shlomo; Bunde, Armin; Stanley, H. Eugene
2005-01-01
For both stock and currency markets, we study the return intervals τ between the daily volatilities of the price changes that are above a certain threshold q. We find that the distribution function Pq(τ) scales with the mean return interval \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\bar {{\\tau}}}\\end{equation*}\\end{document} as \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}P_{q}({\\tau})={\\bar {{\\tau}}}^{-1}f({\\tau}/{\\bar {{\\tau}}})\\end{equation*}\\end{document}. The scaling function f(x) is similar in form for all seven stocks and for all seven currency databases analyzed, and f(x) is consistent with a power-law form, f(x) ∼ x-γ with γ ≈ 2. We also quantify how the conditional distribution Pq(τ|τ0) depends on the previous return interval τ0 and find that small (or large) return intervals are more likely to be followed by small (or large) return intervals. This “clustering” of the volatility return intervals is a previously unrecognized phenomenon that we relate to the long-term correlations known to be present in the volatility. PMID:15980152
Reducing overconfidence in the interval judgments of experts.
Speirs-Bridge, Andrew; Fidler, Fiona; McBride, Marissa; Flander, Louisa; Cumming, Geoff; Burgman, Mark
2010-03-01
Elicitation of expert opinion is important for risk analysis when only limited data are available. Expert opinion is often elicited in the form of subjective confidence intervals; however, these are prone to substantial overconfidence. We investigated the influence of elicitation question format, in particular the number of steps in the elicitation procedure. In a 3-point elicitation procedure, an expert is asked for a lower limit, upper limit, and best guess, the two limits creating an interval of some assigned confidence level (e.g., 80%). In our 4-step interval elicitation procedure, experts were also asked for a realistic lower limit, upper limit, and best guess, but no confidence level was assigned; the fourth step was to rate their anticipated confidence in the interval produced. In our three studies, experts made interval predictions of rates of infectious diseases (Study 1, n = 21 and Study 2, n = 24: epidemiologists and public health experts), or marine invertebrate populations (Study 3, n = 34: ecologists and biologists). We combined the results from our studies using meta-analysis, which found average overconfidence of 11.9%, 95% CI [3.5, 20.3] (a hit rate of 68.1% for 80% intervals)-a substantial decrease in overconfidence compared with previous studies. Studies 2 and 3 suggest that the 4-step procedure is more likely to reduce overconfidence than the 3-point procedure (Cohen's d = 0.61, [0.04, 1.18]). PMID:20030766
Landslide occurrences and recurrence intervals of heavy rainfalls in Japan
NASA Astrophysics Data System (ADS)
Saito, H.; Uchida, T.; Matsuyama, H.; Korup, O.
2015-12-01
Dealing with predicted increases in extreme weather conditions due to climate change requires robust knowledge about controls on rainfall-triggered landslides. This study developed the probable rainfall database from weather radar data, and analyzed the potential correlation between the landslide magnitude-frequency and the recurrence interval of the heavy rainfall across Japan. We analyzed 4,744 rainfall-induced landslides (Saito et al., 2014, Geology), 1 to 72 h rainfalls, and soil water index (SWI). We then estimated recurrence intervals for these rainfall parameters using a Gumbel distribution with jackknife fitting. Results showed that the recurrence intervals of rainfall events which caused landslides (<10^3 m^3) were less than 10 yr across Japan. The recurrence intervals increased with increases in landslide volumes. With regard to the landslides larger than 10^5 m^3, recurrence intervals of the rainfall events were more than 100 yr. These results suggest that recurrence intervals of heavy rainfalls are important for assessing regional landslide hazard in Japan.
Screening mammography intervals among postmenopausal hormone therapy users and nonusers
Onega, Tracy; MacKenzie, Todd; Weiss, Julia; Goodrich, Martha; Titus-Ernstoff, Linda
2013-01-01
Background The recent decline in US breast cancer incidence rates has been attributed to the marked reduction in use of postmenopausal hormone therapy (HT). An alternative explanation is that women who are not routinely seeking medical care to renew HT prescriptions may be less adherent to recommendations for mammographic screening. To investigate the latter possibility, we compared mammographic intervals according to HT use. Methods Using data (1995–2007) from the New Hampshire Mammography Network (NHMN), a state-based mammography registry, we assessed mammographic intervals corresponding to HT use or nonuse among postmenopausal women. We used linear mixed effects models to assess whether the length of screening mammogram intervals differed according to HT use. Results A total of 310,185 mammograms, representing 76,192 postmenopausal women and 319,353 person-years of screening, were included in the analysis. The median screening interval corresponding to HT use overall was 13.0 months (interquartile range: 12.4–15.1) and for nonuse was 13.1 (interquartile range: 12.4–15.8). Virtually, all screening mammograms occurred within a 2-year interval regardless of HT use or nonuse (98.5 and 98.1%, respectively). Conclusions Our findings indicate that screening mammography intervals are similar whether or not women are using HT. Thus, reduced utilization of screening mammography is unlikely to account for the decrease in breast cancer incidence seen soon after the WHI report. PMID:19844798
Y-STR profiling in extended interval (> or = 3 days) postcoital cervicovaginal samples.
Mayntz-Press, Kathleen A; Sims, Lynn M; Hall, Ashley; Ballantyne, Jack
2008-03-01
Depending upon specific situations, some victims of sexual assault provide vaginal samples more than 36-48 h after the incident. We have tested the ability of commercial and in-house Y-STR systems to provide DNA profiles from extended interval (> or =3 days) postcoital samples. The commercial Y-STR systems tested included the AmpFlSTR Yfiler (Applied Biosystems), PowerPlex Y (Promega) and Y-PLEX 12 (Reliagene) products whereas the in-house systems comprised Multiplex I (MPI) and Multiplex B (MPB). Three donor couples were recruited for the study. Postcoital cervicovaginal swabs (x2) were recovered by each of the three females at specified intervals after sexual intercourse (3-7 days). Each time point sample was collected after a separate act of sexual intercourse and was preceded by a 7-day abstention period. As a negative control, a precoital swab was also recovered prior to coitus for each sampling and only data from postcoital samples that demonstrated a lack of male DNA in the associated precoital sample was used. A number of DNA profile enhancement strategies were employed including sampling by cervical brushing, nondifferential DNA extraction methodology, and post-PCR purification. Full Y-STR profiles from cervicovaginal samples recovered 3-4 days after intercourse were routinely obtained. Profiles were also obtainable 5-6 days postcoitus although by this stage partial profiles rather than full profiles were a more likely outcome. The DNA profiles from the sperm fraction of a differential lysis were superior to that obtained when a nondifferential method was employed in that the allelic signal intensities were generally higher and more balanced and exhibited less baseline noise. The incorporation of a simple post-PCR purification process significantly increased the ability to obtain Y-STR profiles, particularly from 5- to 6-day postcoital samples. Remarkably an 8 locus Y-STR profile was obtained from a 7-day postcoital sample, which is approaching the
Electrocardiographic Abnormalities and QTc Interval in Patients Undergoing Hemodialysis
Nie, Yuxin; Zou, Jianzhou; Liang, Yixiu; Shen, Bo; Liu, Zhonghua; Cao, Xuesen; Chen, Xiaohong; Ding, Xiaoqiang
2016-01-01
Background Sudden cardiac death is one of the primary causes of mortality in chronic hemodialysis (HD) patients. Prolonged QTc interval is associated with increased rate of sudden cardiac death. The aim of this article is to assess the abnormalities found in electrocardiograms (ECGs), and to explore factors that can influence the QTc interval. Methods A total of 141 conventional HD patients were enrolled in this study. ECG tests were conducted on each patient before a single dialysis session and 15 minutes before the end of dialysis session (at peak stress). Echocardiography tests were conducted before dialysis session began. Blood samples were drawn by phlebotomy immediately before and after the dialysis session. Results Before dialysis, 93.62% of the patients were in sinus rhythm, and approximately 65% of the patients showed a prolonged QTc interval (i.e., a QTc interval above 440 ms in males and above 460ms in females). A comparison of ECG parameters before dialysis and at peak stress showed increases in heart rate (77.45±11.92 vs. 80.38±14.65 bpm, p = 0.001) and QTc interval (460.05±24.53 ms vs. 470.93±24.92 ms, p<0.001). After dividing patients into two groups according to the QTc interval, lower pre-dialysis serum concentrations of potassium (K+), calcium (Ca2+), phosphorus, calcium* phosphorus (Ca*P), and higher concentrations of plasma brain natriuretic peptide (BNP) were found in the group with prolonged QTc intervals. Patients in this group also had a larger left atrial diameter (LAD) and a thicker interventricular septum, and they tended to be older than patients in the other group. Then patients were divided into two groups according to ΔQTc (ΔQTc = QTc peak-stress- QTc pre-HD). When analyzing the patients whose QTc intervals were longer at peak stress than before HD, we found that they had higher concentrations of Ca2+ and P5+ and lower concentrations of K+, ferritin, UA, and BNP. They were also more likely to be female. In addition, more cardiac
Drug discrimination in rats under concurrent variable-interval variable-interval schedules.
McMillan, D E; Hardwick, W C
2000-01-01
Eight rats were trained to discriminate pentobarbital from saline under a concurrent variable-interval (VI) VI schedule, on which responses on the pentobarbital-biased lever after pentobarbital were reinforced under VI 20 s and responses on the saline-biased lever were reinforced under VI 80 s. After saline, the reinforcement contingencies programmed on the two levers were reversed. The rats made 62.3% of their responses on the pentobarbital-biased lever after pentobarbital and 72.2% on the saline-biased lever after saline, both of which are lower than predicted by the matching law. When the schedule was changed to concurrent VI 50 s VI 50 s for test sessions with saline and the training dose of pentobarbital, responding on the pentobarbital-biased lever after the training dose of pentobarbital and on the saline-biased lever after saline became nearly equal, even during the first 2 min of the session, suggesting that the presence or absence of the training drug was exerting minimal control over responding and making the determination of dose-effect relations of drugs difficult to interpret. When the pentobarbital dose-response curve was determined under the concurrent VI 50-s VI 50-s schedule, responding was fairly evenly distributed on both levers for most rats. Therefore, 6 additional rats were trained to respond under a concurrent VI 60-s VI 240-s schedule. Under this schedule, the rats made 62.6% of their responses on the pentobarbital-biased lever after pentobarbital and 73.5% of their responses on the saline-biased lever after saline, which also is lower than the percentages predicted by perfect matching. When the schedule was changed to a concurrent VI 150-s VI 150-s schedule for 5-min test sessions with additional drugs, the presence or absence of pentobarbital continued to control responding in most rats, and it was possible to generate graded dose-response curves for pentobarbital and other drugs using the data from these 5-min sessions. The dose
Drug-induced QT interval prolongation and torsades de pointes
Tisdale, James E.
2016-01-01
Torsades de pointes (TdP) is a life-threatening arrhythmia associated with prolongation of the corrected QT (QTc) interval on the electrocardiogram. More than 100 drugs available in Canada, including widely used antibiotics, antidepressants, cardiovascular drugs and many others, may cause QTc interval prolongation and TdP. Risk factors for TdP include QTc interval >500 ms, increase in QTc interval ≥60 ms from the pretreatment value, advanced age, female sex, acute myocardial infarction, heart failure with reduced ejection fraction, hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, treatment with diuretics and elevated plasma concentrations of QTc interval–prolonging drugs due to drug interactions, inadequate dose adjustment of renally eliminated drugs in patients with kidney disease and rapid intravenous administration. Pharmacokinetic drug interactions associated with the highest risk of TdP include antifungal agents, macrolide antibiotics (except azithromycin) and drugs to treat human immunodeficiency virus interacting with amiodarone, disopyramide, dofetilide or pimozide. Other important pharmacokinetic interactions include antidepressants (bupropion, duloxetine, fluoxetine, paroxetine) interacting with flecainide, quinidine or thioridazine. Pharmacists play an important role in minimizing the risk of drug-induced QTc interval prolongation and TdP through knowledge of drugs that are associated with a known or possible risk of TdP, individualized assessment of risk of drug-induced QTc interval prolongation, awareness of drug interactions most likely to result in TdP and attention to dose reduction of renally eliminated QTc interval-prolonging drugs in patients with kidney disease. Treatment of hemodynamically stable TdP consists of discontinuation of the offending drug(s), correction of electrolyte abnormalities and administration of intravenous magnesium sulfate 1 to 2 g. PMID:27212965
Psychoacoustic Factors in Musical Intonation: Beats, Interval Tuning, and Inharmonicity.
NASA Astrophysics Data System (ADS)
Keislar, Douglas Fleming
Three psychoacoustic experiments were conducted using musically experienced subjects. In the first two experiments, the interval tested was the perfect fifth F4-C5; in the final one it was the major third F4-A4. The beat rate was controlled by two different methods: (1) simply retuning the interval, and (2) frequency-shifting one partial of each pair of beating partials without changing the overall interval tuning. The second method introduces inharmonicity. In addition, two levels of beat amplitude were introduced by using either a complete spectrum of 16 equal-amplitude partials per note, or by deleting one partial from each pair of beating partials. The results of all three experiments indicate that, for these stimuli, beating does not contribute significantly to the percept of "out-of-tuneness," because it made no difference statistically whether the beat amplitude was maximal or minimal. By contrast, mistuning the interval was highly significant. For the fifths, frequency-shifting the appropriate partials had about as much effect on the perceived intonation as mistuning the interval. For thirds, this effect was weaker, presumably since there were fewer inharmonic partials and they were higher in the harmonic series. Subjects were less consistent in their judgments of thirds than of fifths, perhaps because the equal-tempered and just thirds differ noticeably, unlike fifths. Since it is unlikely that beats would be more audible in real musical situations than under these laboratory conditions, these results suggest that the perception of intonation in music is dependent on the actual interval tuning rather than the concomitant beat rate. If beating partials are unimportant vis-a-vis interval tuning, this strengthens the argument for a cultural basis for musical intonation and scales, as opposed to the acoustical basis set forth by Helmholtz and others.
Dasenaki, Marilena E; Bletsou, Anna A; Hanafi, Ahmad H; Thomaidis, Nikolaos S
2016-12-15
Two liquid chromatography-tandem mass spectrometric methods were developed and validated to determine spinosyn A and D, thiacloprid and pyridalyl in spring onions cultivated under Egyptian field conditions. The degradation rates, the pre-harvest interval (PHI) values and the half-life values of the three pesticides were estimated. QuEChERS was used for sample preparation and the separation was performed on an X-Bridge C18 column with ACN-formic acid 0.1% as the mobile phase. Linear range, method detection limits (MDLs), precision, recovery and matrix effects were estimated. The multi-residue MDLs ranged from 0.02μg/kg (spinosyn A & D) to 0.05μg/kg for pyridalyl. All the investigated pesticides showed high degradation rates. For spinosad the half-life value was 1.2days, for thiacloprid it reached 2.2days and for pyridalyl 4.4days. Furthermore, the calculated PHI values, according to the maximum residue levels set by the EU, were 0days for spinosad, 9.8days for thiacloprid and 39.4days for pyridalyl. PMID:27451196
Statistical regularities in the return intervals of volatility
NASA Astrophysics Data System (ADS)
Wang, F.; Weber, P.; Yamasaki, K.; Havlin, S.; Stanley, H. E.
2007-01-01
We discuss recent results concerning statistical regularities in the return intervals of volatility in financial markets. In particular, we show how the analysis of volatility return intervals, defined as the time between two volatilities larger than a given threshold, can help to get a better understanding of the behavior of financial time series. We find scaling in the distribution of return intervals for thresholds ranging over a factor of 25, from 0.6 to 15 standard deviations, and also for various time windows from one minute up to 390 min (an entire trading day). Moreover, these results are universal for different stocks, commodities, interest rates as well as currencies. We also analyze the memory in the return intervals which relates to the memory in the volatility and find two scaling regimes, ℓ<ℓ* with α1=0.64±0.02 and ℓ> ℓ* with α2=0.92±0.04; these exponent values are similar to results of Liu et al. for the volatility. As an application, we use the scaling and memory properties of the return intervals to suggest a possibly useful method for estimating risk.
Interval Management: Development and Implementation of an Airborne Spacing Concept
NASA Technical Reports Server (NTRS)
Barmore, Bryan E.; Penhallegon, William J.; Weitz, Lesley A.; Bone, Randall S.; Levitt, Ian; Flores Kriegsfeld, Julia A.; Arbuckle, Doug; Johnson, William C.
2016-01-01
Interval Management is a suite of ADS-B-enabled applications that allows the air traffic controller to instruct a flight crew to achieve and maintain a desired spacing relative to another aircraft. The flight crew, assisted by automation, manages the speed of their aircraft to deliver more precise inter-aircraft spacing than is otherwise possible, which increases traffic throughput at the same or higher levels of safety. Interval Management has evolved from a long history of research and is now seen as a core NextGen capability. With avionics standards recently published, completion of an Investment Analysis Readiness Decision by the FAA, and multiple flight tests planned, Interval Management will soon be part of everyday use in the National Airspace System. Second generation, Advanced Interval Management capabilities are being planned to provide a wider range of operations and improved performance and benefits. This paper briefly reviews the evolution of Interval Management and describes current development and deployment plans. It also reviews concepts under development as the next generation of applications.
Application of Interval Predictor Models to Space Radiation Shielding
NASA Technical Reports Server (NTRS)
Crespo, Luis G.; Kenny, Sean P.; Giesy,Daniel P.; Norman, Ryan B.; Blattnig, Steve R.
2016-01-01
This paper develops techniques for predicting the uncertainty range of an output variable given input-output data. These models are called Interval Predictor Models (IPM) because they yield an interval valued function of the input. This paper develops IPMs having a radial basis structure. This structure enables the formal description of (i) the uncertainty in the models parameters, (ii) the predicted output interval, and (iii) the probability that a future observation would fall in such an interval. In contrast to other metamodeling techniques, this probabilistic certi cate of correctness does not require making any assumptions on the structure of the mechanism from which data are drawn. Optimization-based strategies for calculating IPMs having minimal spread while containing all the data are developed. Constraints for bounding the minimum interval spread over the continuum of inputs, regulating the IPMs variation/oscillation, and centering its spread about a target point, are used to prevent data over tting. Furthermore, we develop an approach for using expert opinion during extrapolation. This metamodeling technique is illustrated using a radiation shielding application for space exploration. In this application, we use IPMs to describe the error incurred in predicting the ux of particles resulting from the interaction between a high-energy incident beam and a target.
Interval process model and non-random vibration analysis
NASA Astrophysics Data System (ADS)
Jiang, C.; Ni, B. Y.; Liu, N. Y.; Han, X.; Liu, J.
2016-07-01
This paper develops an interval process model for time-varying or dynamic uncertainty analysis when information of the uncertain parameter is inadequate. By using the interval process model to describe a time-varying uncertain parameter, only its upper and lower bounds are required at each time point rather than its precise probability distribution, which is quite different from the traditional stochastic process model. A correlation function is defined for quantification of correlation between the uncertain-but-bounded variables at different times, and a matrix-decomposition-based method is presented to transform the original dependent interval process into an independent one for convenience of subsequent uncertainty analysis. More importantly, based on the interval process model, a non-random vibration analysis method is proposed for response computation of structures subjected to time-varying uncertain external excitations or loads. The structural dynamic responses thus can be derived in the form of upper and lower bounds, providing an important guidance for practical safety analysis and reliability design of structures. Finally, two numerical examples and one engineering application are investigated to demonstrate the feasibility of the interval process model and corresponding non-random vibration analysis method.
Recommended Nordic paediatric reference intervals for 21 common biochemical properties.
Hilsted, Linda; Rustad, Pål; Aksglæde, Lise; Sørensen, Kaspar; Juul, Anders
2013-02-01
Paediatric reference intervals based on samples from healthy children are difficult to establish and consequently data are often from hospitalized children. Furthermore, biases may present in published data due to differences in the analytical methods employed. Blood samples from 1429 healthy Danish children were collected for establishing reference intervals for 21 common biochemical properties (Alanine transaminase, Albumin, Alkaline phosphatase, Aspartate transaminase, Bilirubin, Calcium, Cholesterol, Creatinine, Creatine kinase, HDL-Cholesterol, Iron, Lactate dehydrogenase, LDL- Cholesterol, Magnesium, Phosphate, Potassium, Protein, Sodium, Transferrin, Triglycerides and Urate). Samples were analyzed on a Roche-Modular-P/ISE-system. The NORIP reference material (NFKK Reference Serum X) was included in all the analytical runs. Reference values were recalculated according to the target values of X for the properties and statistical calculations carried out as performed in the NORIP study. Thus commutable (regarding analytical method) reference intervals for 20 properties were established and for LDL-Cholesterol reference intervals were reported for the specific analytical method employed. The data were compared to previous studies and to those obtained from the youngest age group in the NORIP study. Marked age differences were observed for most of the properties. Several properties also showed gender-related differences, mainly at the onset of puberty. Data are presented as suggested intervals for combined age groups, but can be accessed via the NORIP home page if more detailed division according to age or gender is desired. PMID:23013046
Mahalakshmi, V.; Gururaj, N.; Sathya, R.; Sabarinath, T. R.; Sivapathasundharam, B.; Kalaiselvan, S.
2016-01-01
Introduction: Conventional methods to estimate the time of death are adequate, but a histological method is yet unavailable to assess postmortem interval (PMI). The autolytic changes that occur in an unfixed antemortem gingival tissue which reflects histologically at an early stage are similar to changes that occur in postmortem tissue. These histological changes can be used and applied in a postmortem tissue as a method to assess PMI. Aims: The aim of the study is to assess the histological changes in a gingival tissue left unfixed for various time intervals and to correlate the findings with duration. Materials and Methods: Sixty gingival tissues obtained from patients following therapeutic extractions, impactions, gingivectomy and crown lengthening procedures were used. Each tissue obtained was divided into two pieces and labeled as “A”, the control group and “ B” the study group. Tissues labeled “A” were fixed in 10% formalin immediately and tissues labeled“B” were placed in closed containers and fixed after 15, 30, 45 min, 1, 2, and 4 h time interval. Of the sixty tissues in the study group “ B”, ten tissues were used for each time interval under investigation. All the fixed tissues were processed, stained, assessed, and analyzed statistically using Pearson correlation and regression analysis. Results: Histological changes appear at 15 min in an unfixed antemortem tissue. At 2 h interval, all layers with few cells in basal cell layer are involved. At 4 h interval, loss of stratification and complete homogenization of cells in the superficial layers with prominent changes in basal layer is evident. There was a positive correlation (<1.0) between the time interval and the appearance of the histological changes. Conclusion: Histological changes such as complete homogenization of cells in superficial layers and loss of epithelial architecture at 4 h in unfixed antemortem tissue may be used as a criterion to estimate PMI, after further studies
Drug-induced QT interval prolongation: mechanisms and clinical management
Nachimuthu, Senthil; Assar, Manish D.
2012-01-01
The prolonged QT interval is both widely seen and associated with the potentially deadly rhythm, Torsades de Pointes (TdP). While it can occur spontaneously in the congenital form, there is a wide array of drugs that have been implicated in the prolongation of the QT interval. Some of these drugs have either been restricted or withdrawn from the market due to the increased incidence of fatal polymorphic ventricular tachycardia. The list of drugs that cause QT prolongation continues to grow, and an updated list of specific drugs that prolong the QT interval can be found at www.qtdrugs.org. This review focuses on the mechanism of drug-induced QT prolongation, risk factors for TdP, culprit drugs, prevention and monitoring of prolonged drug-induced QT prolongation and treatment strategies. PMID:25083239
Atomic temporal interval relations in branching time: calculation and application
NASA Astrophysics Data System (ADS)
Anger, Frank D.; Ladkin, Peter B.; Rodriguez, Rita V.
1991-03-01
A practical method of reasoning about intervals in a branching-time model which is dense, unbounded, future-branching, without rejoining branches is presented. The discussion is based on heuristic constraint- propagation techniques using the relation algebra of binary temporal relations among the intervals over the branching-time model. This technique has been applied with success to models of intervals over linear time by Allen and others, and is of cubic-time complexity. To extend it to branding-time models, it is necessary to calculate compositions of the relations; thus, the table of compositions for the 'atomic' relations is computed, enabling the rapid determination of the composition of arbitrary relations, expressed as disjunctions or unions of the atomic relations.
Monocular viewing prolongs reversal interval of perceptual rival figure
NASA Astrophysics Data System (ADS)
Tanahashi, Shigehito; Segawa, Kaori; Zheng, Meihong; Kuze, Junko; Ukai, Kazuhiko
2012-09-01
The authors examined whether the perceptual reversal rate changes under monocular versus binocular viewing conditions. Our results suggest that the perceptual reversal interval increases during monocular viewing. The ratio of the reversal rate (1/interval) for the two viewing conditions (binocular/monocular) was 1.28 over a wide range of pattern luminance levels. The quoted ratio was 1.40 when the luminance was high. Such a ratio parallels the value of a well-known binocular summation index (sqrt 2 ), which was derived from the signal detection theory. The binocular summation index shows that the strength of an input signal is enhanced by binocular viewing. However, how the binocular summation shortens the perceptual reversal interval is unclear. This issue can be resolved if the perceptual reversal is derived by integrating the strength of an unconscious image signal. Thus, we discussed the mechanism of perceptual switch by associating two classical, well-studied phenomena, binocular summation and perceptual switch.
Unwinding the Molecular Basis of Interval and Circadian Timing
Agostino, Patricia V.; Golombek, Diego A.; Meck, Warren H.
2011-01-01
Neural timing mechanisms range from the millisecond to diurnal, and possibly annual, frequencies. Two of the main processes under study are the interval timer (seconds-to-minute range) and the circadian clock. The molecular basis of these two mechanisms is the subject of intense research, as well as their possible relationship. This article summarizes data from studies investigating a possible interaction between interval and circadian timing and reviews the molecular basis of both mechanisms, including the discussion of the contribution from studies of genetically modified animal models. While there is currently no common neurochemical substrate for timing mechanisms in the brain, circadian modulation of interval timing suggests an interaction of different frequencies in cerebral temporal processes. PMID:22022309
Persistent Fluctuations in Stride Intervals under Fractal Auditory Stimulation
Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J.; Daffertshofer, Andreas
2014-01-01
Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals. PMID:24651455
Reference intervals for serum creatine kinase in athletes
Mougios, Vassilis
2007-01-01
Background The serum concentration of creatine kinase (CK) is used widely as an index of skeletal muscle fibre damage in sport and exercise. Since athletes have higher CK values than non‐athletes, comparing the values of athletes to the normal values established in non‐athletes is pointless. The purpose of this study was to introduce reference intervals for CK in athletes. Method CK was assayed in serum samples from 483 male athletes and 245 female athletes, aged 7–44. Samples had been obtained throughout the training and competition period. For comparison, CK was also assayed in a smaller number of non‐athletes. Reference intervals (2.5th to 97.5th percentile) were calculated by the non‐parametric method. Results The reference intervals were 82–1083 U/L (37°C) in male and 47–513 U/L in female athletes. The upper reference limits were twice the limits reported for moderately active non‐athletes in the literature or calculated in the non‐athletes in this study. The upper limits were up to six times higher than the limits reported for inactive individuals in the literature. When reference intervals were calculated specifically in male football (soccer) players and swimmers, a threefold difference in the upper reference limit was found (1492 vs 523 U/L, respectively), probably resulting from the different training and competition demands of the two sports. Conclusion Sport training and competition have profound effects on the reference intervals for serum CK. Introducing sport‐specific reference intervals may help to avoid misinterpretation of high values and to optimise training. PMID:17526622
Fast and Accurate Construction of Confidence Intervals for Heritability.
Schweiger, Regev; Kaufman, Shachar; Laaksonen, Reijo; Kleber, Marcus E; März, Winfried; Eskin, Eleazar; Rosset, Saharon; Halperin, Eran
2016-06-01
Estimation of heritability is fundamental in genetic studies. Recently, heritability estimation using linear mixed models (LMMs) has gained popularity because these estimates can be obtained from unrelated individuals collected in genome-wide association studies. Typically, heritability estimation under LMMs uses the restricted maximum likelihood (REML) approach. Existing methods for the construction of confidence intervals and estimators of SEs for REML rely on asymptotic properties. However, these assumptions are often violated because of the bounded parameter space, statistical dependencies, and limited sample size, leading to biased estimates and inflated or deflated confidence intervals. Here, we show that the estimation of confidence intervals by state-of-the-art methods is inaccurate, especially when the true heritability is relatively low or relatively high. We further show that these inaccuracies occur in datasets including thousands of individuals. Such biases are present, for example, in estimates of heritability of gene expression in the Genotype-Tissue Expression project and of lipid profiles in the Ludwigshafen Risk and Cardiovascular Health study. We also show that often the probability that the genetic component is estimated as 0 is high even when the true heritability is bounded away from 0, emphasizing the need for accurate confidence intervals. We propose a computationally efficient method, ALBI (accurate LMM-based heritability bootstrap confidence intervals), for estimating the distribution of the heritability estimator and for constructing accurate confidence intervals. Our method can be used as an add-on to existing methods for estimating heritability and variance components, such as GCTA, FaST-LMM, GEMMA, or EMMAX. PMID:27259052
Persistent fluctuations in stride intervals under fractal auditory stimulation.
Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J; Daffertshofer, Andreas
2014-01-01
Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals. PMID:24651455
Multipoint interval mapping of quantitative trait loci, using sib pairs
Fulker, D.W.; Cherny, S.S.; Cardon, L.R.
1995-05-01
The sib-pair interval-mapping procedure of Fulker and Cardon is extended to take account of all available marker information on a chromosome simultaneously. The method provides a computationally fast multipoint analysis of sib-pair data, using a modified Haseman-Elston approach. It gives results very similar to those of the earlier interval-mapping procedure when marker information is relatively uniform and a coarse map is used. However, there is substantial improvement over the original method when markers differ in information content and/or when a dense map is employed. The method is illustrated by using simulated sib-pair data. 14 refs., 4 figs., 2 tabs.
PREDICTION INTERVALS FOR INTEGRALS OF GAUSSIAN RANDOM FIELDS.
De Oliveira, Victor; Kone, Bazoumana
2015-03-01
Methodology is proposed for the construction of prediction intervals for integrals of Gaussian random fields over bounded regions (called block averages in the geostatistical literature) based on observations at a finite set of sampling locations. Two bootstrap calibration algorithms are proposed, termed indirect and direct, aimed at improving upon plug-in prediction intervals in terms of coverage probability. A simulation study is carried out that illustrates the effectiveness of both procedures, and these procedures are applied to estimate block averages of chromium traces in a potentially contaminated region in Switzerland. PMID:25431507
PREDICTION INTERVALS FOR INTEGRALS OF GAUSSIAN RANDOM FIELDS
De Oliveira, Victor; Kone, Bazoumana
2014-01-01
Methodology is proposed for the construction of prediction intervals for integrals of Gaussian random fields over bounded regions (called block averages in the geostatistical literature) based on observations at a finite set of sampling locations. Two bootstrap calibration algorithms are proposed, termed indirect and direct, aimed at improving upon plug-in prediction intervals in terms of coverage probability. A simulation study is carried out that illustrates the effectiveness of both procedures, and these procedures are applied to estimate block averages of chromium traces in a potentially contaminated region in Switzerland. PMID:25431507
Control of Angular Intervals for Angle-Multiplexed Holographic Memory
NASA Astrophysics Data System (ADS)
Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki
2009-03-01
In angle-multiplexed holographic memory, the full width at half maximum of the Bragg selectivity curves is dependent on the angle formed between the medium and incident laser beams. This indicates the possibility of high density and high multiplexing number by varying the angular intervals between adjacent holograms. We propose an angular interval scheduling for closely stacking holograms into medium even when the angle range is limited. We obtained bit error rates of the order of 10-4 under the following conditions: medium thickness of 1 mm, laser beam wavelength of 532 nm, and angular multiplexing number of 300.
Contribution to Modal and Spectral Interval Finite Element Analysis
NASA Astrophysics Data System (ADS)
Sága, Milan; Bednár, R.; Vaško, M.
Our paper deals with a non-probabilistic computational approach for mechanical systems with structural uncertainties. Uncertainties are considered as bounded possible values - intervals. The main goal is to propose algorithms for modal and spectral interval computations on FE models. An application of the chosen approaches is presented, i.e. the first one a simple combination of only inf-values or only sup-values; the second one presents full combination of all inf-sup values; the third one uses the optimization process as a tool for finding out a inf-sup solution and last one is Monte Carlo technique as a comparison tool.
Specifying real-time systems with interval logic
NASA Technical Reports Server (NTRS)
Rushby, John
1988-01-01
Pure temporal logic makes no reference to time. An interval temporal logic and an extension to that logic which includes real time constraints are described. The application of this logic by giving a specification for the well-known lift (elevator) example is demonstrated. It is shown how interval logic can be extended to include a notion of process. How the specification language and verification environment of EHDM could be enhanced to support this logic is described. A specification of the alternating bit protocol in this extended version of the specification language of EHDM is given.
An interval logic for higher-level temporal reasoning
NASA Technical Reports Server (NTRS)
Schwartz, R. L.; Melliar-Smith, P. M.; Vogt, F. H.; Plaisted, D. A.
1983-01-01
Prior work explored temporal logics, based on classical modal logics, as a framework for specifying and reasoning about concurrent programs, distributed systems, and communications protocols, and reported on efforts using temporal reasoning primitives to express very high level abstract requirements that a program or system is to satisfy. Based on experience with those primitives, this report describes an Interval Logic that is more suitable for expressing such higher level temporal properties. The report provides a formal semantics for the Interval Logic, and several examples of its use. A description of decision procedures for the logic is also included.
Systolic time interval data acquisition system. Specialized cardiovascular studies
NASA Technical Reports Server (NTRS)
Baker, J. T.
1976-01-01
The development of a data acquisition system for noninvasive measurement of systolic time intervals is described. R-R interval from the ECG determines instantaneous heart rate prior to the beat to be measured. Total electromechanical systole (Q-S2) is measured from the onset of the ECG Q-wave to the onset of the second heart sound (S2). Ejection time (ET or LVET) is measured from the onset of carotid upstroke to the incisure. Pre-ejection period (PEP) is computed by subtracting ET from Q-S2. PEP/ET ratio is computed directly.
NASA Astrophysics Data System (ADS)
Zamri, Nurnadiah; Abdullah, Lazim
2014-06-01
Flood control project is a complex issue which takes economic, social, environment and technical attributes into account. Selection of the best flood control project requires the consideration of conflicting quantitative and qualitative evaluation criteria. When decision-makers' judgment are under uncertainty, it is relatively difficult for them to provide exact numerical values. The interval type-2 fuzzy set (IT2FS) is a strong tool which can deal with the uncertainty case of subjective, incomplete, and vague information. Besides, it helps to solve for some situations where the information about criteria weights for alternatives is completely unknown. Therefore, this paper is adopted the information interval type-2 entropy concept into the weighting process of interval type-2 fuzzy TOPSIS. This entropy weight is believed can effectively balance the influence of uncertainty factors in evaluating attribute. Then, a modified ranking value is proposed in line with the interval type-2 entropy weight. Quantitative and qualitative factors that normally linked with flood control project are considered for ranking. Data in form of interval type-2 linguistic variables were collected from three authorised personnel of three Malaysian Government agencies. Study is considered for the whole of Malaysia. From the analysis, it shows that diversion scheme yielded the highest closeness coefficient at 0.4807. A ranking can be drawn using the magnitude of closeness coefficient. It was indicated that the diversion scheme recorded the first rank among five causes.
ERIC Educational Resources Information Center
Zhang, Guangjian; Preacher, Kristopher J.; Luo, Shanhong
2010-01-01
This article is concerned with using the bootstrap to assign confidence intervals for rotated factor loadings and factor correlations in ordinary least squares exploratory factor analysis. Coverage performances of "SE"-based intervals, percentile intervals, bias-corrected percentile intervals, bias-corrected accelerated percentile intervals, and…
The lucid interval associated with epidural bleeding: evolving understanding.
Ganz, Jeremy C
2013-04-01
The aim of this paper was to elucidate the evolution of our understanding of the term "lucid interval." A number of texts were reviewed to assess their suitability for analysis. The primary requirement was that the text contain detailed descriptions of a series of patients. Details of the clinical course, the findings and timing of surgery, and, when relevant, the time of death and postmortem findings were required. Books written by Henri-François Le Dran, Percival Pott, and James Hill fulfilled these criteria. Surgical findings included the presence and type of fractures, changes in the bone, separation of periosteum, malodorous or purulent material, tense brain, and hematoma. Postmortem findings supplemented and/or complemented the surgical findings. The courses of the patients were then tabulated, and the correlation between different clinical and operative findings was thereby determined. Our understanding of a lucid interval began in the early 18th century with the work of Henri-François Le Dran and Percival Pott in London. They did not, however, demonstrate an interval without symptoms between trauma and deterioration in patients with epidural hematomas (EDHs). The interval they described was longer than usually expected with EDHs and occurred exclusively in patients who had a posttraumatic infection. In 1751, James Hill, from Dumfries, Scotland, described the first hematoma-related lucid interval in a patient with a subdural hematoma. The first case of a lucid interval associated with an EDH was described by John Abernethy. In the 19th century, Jonathan Hutchinson and Walter Jacobson described the interval as it is known today, in cases of EDH. The most recent work on the topic came from studies in Cincinnati and Oslo, where it was demonstrated that bleeding can separate dura mater and that hemorrhage into the epidural space can be shunted out via the veins. This shunting could delay the accumulation of a hematoma and thus the rise in intracranial pressure
Mnemonic benefits of retrieval practice at short retention intervals.
Rowland, Christopher A; DeLosh, Edward L
2015-01-01
The testing effect refers to the retention benefit conferred by prior retrieval of information from memory. Although the testing effect is a robust phenomenon, a common assumption is that reliable memory benefits only emerge after long retention intervals of days or weeks. The present study focused on potential test-induced retention benefits for brief retention intervals on the order of minutes and tens of seconds. Participants in four experiments studied lists of words. Some of the items were subjected to an initial cued recall test, and others were re-presented for additional study. Free recall tests were administered in each experiment following retention intervals ranging from 30 s to 8 min. When initial retrieval practice was successful (Experiments 1 through 3), or feedback compensated for unsuccessful retrieval (Experiment 4), significant testing effects emerged at all retention intervals. Results are discussed in the context of a bifurcated item-distribution model and highlight the importance of initial test performance and the type of analysis employed when examining testing effect data. PMID:24579674
Researchers Misunderstand Confidence Intervals and Standard Error Bars
ERIC Educational Resources Information Center
Belia, Sarah; Fidler, Fiona; Williams, Jennifer; Cumming, Geoff
2005-01-01
Little is known about researchers' understanding of confidence intervals (CIs) and standard error (SE) bars. Authors of journal articles in psychology, behavioral neuroscience, and medicine were invited to visit a Web site where they adjusted a figure until they judged 2 means, with error bars, to be just statistically significantly different (p…
High-Intensity Interval Training for Improving Postprandial Hyperglycemia
ERIC Educational Resources Information Center
Little, Jonathan P.; Francois, Monique E.
2014-01-01
High-intensity interval training (HIIT) has garnered attention in recent years as a time-efficient exercise option for improving cardiovascular and metabolic health. New research demonstrates that HIIT may be particularly effective for improving postprandial hyperglycemia in individuals with, or at risk for, type 2 diabetes (T2D). These findings…
Precise time and time interval data handling and reduction
NASA Technical Reports Server (NTRS)
Fisher, L. C.
1973-01-01
In the past year, the increase in Precise Time And Time Interval data to be reduced to the U.S. Naval Observatory Master Clock and the requirement for its quick dissemination has necessitated development of more efficient methods of data handling and reduction. An outline of the data involved and of the Time Service computerization of these functions is presented.
A model of interval timing by neural integration
Simen, Patrick; Balci, Fuat; deSouza, Laura; Cohen, Jonathan D.; Holmes, Philip
2011-01-01
We show that simple assumptions about neural processing lead to a model of interval timing as a temporal integration process, in which a noisy firing-rate representation of time rises linearly on average toward a response threshold over the course of an interval. Our assumptions include: that neural spike trains are approximately independent Poisson processes; that correlations among them can be largely cancelled by balancing excitation and inhibition; that neural populations can act as integrators; and that the objective of timed behavior is maximal accuracy and minimal variance. The model accounts for a variety of physiological and behavioral findings in rodents, monkeys and humans, including ramping firing rates between the onset of reward-predicting cues and the receipt of delayed rewards, and universally scale-invariant response time distributions in interval timing tasks. It furthermore makes specific, well-supported predictions about the skewness of these distributions, a feature of timing data that is usually ignored. The model also incorporates a rapid (potentially one-shot) duration-learning procedure. Human behavioral data support the learning rule’s predictions regarding learning speed in sequences of timed responses. These results suggest that simple, integration-based models should play as prominent a role in interval timing theory as they do in theories of perceptual decision making, and that a common neural mechanism may underlie both types of behavior. PMID:21697374
Patterns of interval correlations in neural oscillators with adaptation
Schwalger, Tilo; Lindner, Benjamin
2013-01-01
Neural firing is often subject to negative feedback by adaptation currents. These currents can induce strong correlations among the time intervals between spikes. Here we study analytically the interval correlations of a broad class of noisy neural oscillators with spike-triggered adaptation of arbitrary strength and time scale. Our weak-noise theory provides a general relation between the correlations and the phase-response curve (PRC) of the oscillator, proves anti-correlations between neighboring intervals for adapting neurons with type I PRC and identifies a single order parameter that determines the qualitative pattern of correlations. Monotonically decaying or oscillating correlation structures can be related to qualitatively different voltage traces after spiking, which can be explained by the phase plane geometry. At high firing rates, the long-term variability of the spike train associated with the cumulative interval correlations becomes small, independent of model details. Our results are verified by comparison with stochastic simulations of the exponential, leaky, and generalized integrate-and-fire models with adaptation. PMID:24348372
Confidence Interval Coverage for Cohen's Effect Size Statistic
ERIC Educational Resources Information Center
Algina, James; Keselman, H. J.; Penfield, Randall D.
2006-01-01
Kelley compared three methods for setting a confidence interval (CI) around Cohen's standardized mean difference statistic: the noncentral-"t"-based, percentile (PERC) bootstrap, and biased-corrected and accelerated (BCA) bootstrap methods under three conditions of nonnormality, eight cases of sample size, and six cases of population effect size…
Constructing Approximate Confidence Intervals for Parameters with Structural Equation Models
ERIC Educational Resources Information Center
Cheung, Mike W. -L.
2009-01-01
Confidence intervals (CIs) for parameters are usually constructed based on the estimated standard errors. These are known as Wald CIs. This article argues that likelihood-based CIs (CIs based on likelihood ratio statistics) are often preferred to Wald CIs. It shows how the likelihood-based CIs and the Wald CIs for many statistics and psychometric…
Likelihood-Based Confidence Intervals in Exploratory Factor Analysis
ERIC Educational Resources Information Center
Oort, Frans J.
2011-01-01
In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated factor loadings and factor correlations, by…
Evaluating the Equal-Interval Hypothesis with Test Score Scales
ERIC Educational Resources Information Center
Domingue, Benjamin Webre
2012-01-01
In psychometrics, it is difficult to verify that measurement instruments can be used to produce numeric values with the desirable property that differences between units are equal-interval because the attributes being measured are latent. The theory of additive conjoint measurement (e.g., Krantz, Luce, Suppes, & Tversky, 1971, ACM) guarantees…
Confidence Intervals and Replication: Where Will the Next Mean Fall?
ERIC Educational Resources Information Center
Cumming, Geoff; Maillardet, Robert
2006-01-01
Confidence intervals (CIs) give information about replication, but many researchers have misconceptions about this information. One problem is that the percentage of future replication means captured by a particular CI varies markedly, depending on where in relation to the population mean that CI falls. The authors investigated the distribution of…
Confidence Intervals for Assessing Heterogeneity in Generalized Linear Mixed Models
ERIC Educational Resources Information Center
Wagler, Amy E.
2014-01-01
Generalized linear mixed models are frequently applied to data with clustered categorical outcomes. The effect of clustering on the response is often difficult to practically assess partly because it is reported on a scale on which comparisons with regression parameters are difficult to make. This article proposes confidence intervals for…
Motor and Executive Control in Repetitive Timing of Brief Intervals
ERIC Educational Resources Information Center
Holm, Linus; Ullen, Fredrik; Madison, Guy
2013-01-01
We investigated the causal role of executive control functions in the production of brief time intervals by means of a concurrent task paradigm. To isolate the influence of executive functions on timing from motor coordination effects, we dissociated executive load from the number of effectors used in the dual task situation. In 3 experiments,…
Response Priming Patterns Differ with Interstimulus Interval Duration
ERIC Educational Resources Information Center
Spencer, Kristie A.; Wiley, Erin
2008-01-01
Priming paradigms make it possible to study the nature of response preparation before the onset of movement. One way to examine this process is through manipulation of the interstimulus interval (ISI). The timing of the prime and target presentation has been shown to have distinct effects on reaction time patterns, in both healthy and…
Concurrent activities and instructed human fixed-interval performance.
Barnes, D; Keenan, M
1993-01-01
Two experiments explored the effects of two types of concurrent activity on human fixed-interval performance. Eight adult subjects were given access to either reading material or a working television set across three fixed-interval values (60 s, 300 s, and 600 s). During Experiment 1, 2 subjects produced "scalloped" patterns and reported no verbal regulation (e.g., counting) in the presence of the reading material, but shifted to low-rate patterns and reported verbal regulation when the reading material was withdrawn. The 2 other subjects in Experiment 1 produced consistent low-rate performances and reported verbal regulation during access to reading material. However, when these subjects were given access to a working television set, they produced scalloped patterns and reported no verbal regulation. During Experiment 2, 4 experimentally naive subjects showed consistent scalloped patterning and no verbal regulation across fixed-interval values when they were allowed to watch television. When access to the television was denied, subjects reliably reported verbal regulation, and low-rate patterns emerged. These behavioral effects focus our attention on the contingencies that control human performance on fixed-interval schedules. PMID:8315367
Measurement of Phonated Intervals during Four Fluency-Inducing Conditions
ERIC Educational Resources Information Center
Davidow, Jason H.; Bothe, Anne K.; Andreatta, Richard D.; Ye, Jun
2009-01-01
Purpose: Previous investigations of persons who stutter have demonstrated changes in vocalization variables during fluency-inducing conditions (FICs). A series of studies has also shown that a reduction in short intervals of phonation, those from 30 to 200 ms, is associated with decreased stuttering. The purpose of this study, therefore, was to…
Exercise-induced hypoalgesia - interval versus continuous mode.
Kodesh, Einat; Weissman-Fogel, Irit
2014-07-01
Aerobic exercise at approximately 70% of maximal aerobic capacity moderately reduces pain sensitivity and attenuates pain, even after a single session. If the analgesic effects depend on exercise intensity, then high-intensity interval exercise at 85% of maximal aerobic capacity should further reduce pain. The aim of this study was to explore the exercise-induced analgesic effects of high-intensity interval aerobic exercise and to compare them with the analgesic effects of moderate continuous aerobic exercise. Twenty-nine young untrained healthy males were randomly assigned to aerobic-continuous (70% heart rate reserve (HRR)) and interval (4 × 4 min at 85% HRR and 2 min at 60% HRR between cycles) exercise modes, each lasting 30 min. Psychophysical pain tests, pressure and heat pain thresholds (HPT), and tonic heat pain (THP) were conducted before and after exercise sessions. Repeated measures ANOVA was used for data analysis. HPT increased (p = 0.056) and THP decreased (p = 0.013) following exercise unrelated to exercise type. However, the main time effect (pre-/postexercise) was a trend of increased HPT (45.6 ± 1.9 °C to 46.2 ± 1.8 °C; p = 0.082) and a significant reduction in THP (from 50.7 ± 25 to 45.9 ± 25.4 numeric pain scale; p = 0.043) following interval exercise. No significant change was found for the pressure pain threshold following either exercise type. In conclusion, interval exercise (85% HRR) has analgesic effects on experimental pain perception. This, in addition to its cardiovascular, muscular, and metabolic advantages may promote its inclusion in pain management programs. PMID:24773287