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Time-series Analysis (time-sery + analysis)
Selected AbstractsTHE SHORT-TERM EFFECTS OF EXECUTIONS ON HOMICIDES: DETERRENCE, DISPLACEMENT, OR BOTH?,CRIMINOLOGY, Issue 4 2009KENNETH C. LAND Does the death penalty save lives? In recent years, a new round of research has been using annual time-series panel data from the 50 U.S. states for 25 or so years from the 1970s to the late 1990s that claims to find many lives saved through reductions in subsequent homicide rates after executions. This research, in turn, has produced a round of critiques, which concludes that these findings are not robust enough to model even small changes in specifications that yield dramatically different results. A principal reason for this sensitivity of the findings is that few state-years exist (about 1 percent of all state-years) in which six or more executions have occurred. To provide a different perspective, we focus on Texas, a state that has used the death penalty with sufficient frequency to make possible relatively stable estimates of the homicide response to executions. In addition, we narrow the observation intervals for recording executions and homicides from the annual calendar year to monthly intervals. Based on time-series analyses and independent-validation tests, our best-fitting model shows that, from January 1994 through December 2005, evidence exists of modest, short-term reductions in homicides in Texas in the first and fourth months that follow an execution,about 2.5 fewer homicides total. Another model suggests, however, that in addition to homicide reductions, some displacement of homicides may be possible from one month to another in the months after an execution, which reduces the total reduction in homicides after an execution to about .5 during a 12-month period. Implications for additional research and the need for future analysis and replication are discussed. [source] Repaglinide treatment amplifies first-phase insulin secretion and high-frequency pulsatile insulin release in Type 2 diabetesDIABETIC MEDICINE, Issue 10 2005M. Hollingdal Abstract Aims/hypothesis First-phase insulin release and coordinated insulin pulsatility are disturbed in Type 2 diabetes. The present study was undertaken to explore a possible influence of the oral prandial glucose regulator, repaglinide, on first-phase insulin secretion and high-frequency insulin pulsatility in Type 2 diabetes. Methods We examined 10 patients with Type 2 diabetes in a double-blind placebo-controlled, cross-over design. The participants were treated for 6 weeks with either repaglinide [2,9 mg/day (average 5.9 mg)] or placebo in random order. At the end of each treatment period, first-phase insulin secretion was measured. Entrainment of insulin secretion was assessed utilizing 1-min glucose bolus exposure (6 mg/kg body weight every 10 min) for 60 min during (A) baseline conditions, i.e. 12 h after the last repaglinide/placebo administration, and (B) 30 min after an oral dose of 0.5 mg repaglinide/placebo with subsequent application of time-series analyses. Results Postprandial (2-h) blood glucose was significantly reduced by repaglinide after 5 weeks of treatment (P < 0.001). The fall in HbA1c did not reach statistical significance (P = 0.07). AUCins,0,12 min during the first-phase insulin secretion test was enhanced (P < 0.05). In addition, glucose entrained insulin secretory burst mass and amplitude increased markedly (burst mass: repaglinide, 44.4 ± 6.0 pmol/l/pulse vs. placebo, 31.4 ± 3.3 pmol/l/pulse, P < 0.05; burst amplitude: repaglinide, 17.7 ± 2.4 pmol/l/min vs. placebo, 12.6 ± 1.3 pmol/l/min, P < 0.05) while basal insulin (non-pulsatile) secretion was unaltered. After acute repaglinide exposure (0.5 mg) basal insulin secretion increased significantly (P < 0.05). Neither acute nor chronic repaglinide administration influenced frequency or regularity of insulin pulses during entrainment. Conclusion/interpretation Repaglinide augments first-phase insulin secretion as well as high-frequency insulin secretory burst mass and amplitude during glucose entrainment in patients with Type 2 diabetes, while regularity of the insulin release process was unaltered. Diabet. Med. (2005) [source] Auditory temporal processing deficits in children with reading disabilitiesDYSLEXIA, Issue 3 2007Ravit Cohen-Mimran Abstract The role of central auditory processing in reading skill development and reading disorders is unclear. The purpose of this study was to examine whether individuals with specific reading disabilities (SRD) have deficits in processing rapidly presented, serially ordered non-speech auditory signals. To this end, we compared 12 children with SRD and 12 children without SRD on their ability to detect differences and similarities in pure tones of 1000 and 2000 Hz when these signals were presented in pairs (same or different tones, randomly ordered) with short (50 ms) versus long (500 ms) inter stimulous intervals (ISI). Results showed that the children with SRD had significant difficulty in discriminating between pure tones with short, but not long ISI, whereas the controls performed well with both short and long ISI. The two groups did not differ significantly on measures of attention (d2) and performance IQ, and there were no significant correlations between these measures and ISI performance. There were significant correlations between the short ISI performance and phonologic awareness test results when the two groups were combined. These findings support the specific rapid auditory processing deficit hypothesis of SRD. Examination of intra-subject variability in performance indicated that children from the SRD group showed both decrement in performance with time on task and high overall variability in performance as compared to the controls. These findings underpin the importance of using time-series analyses of performance. Copyright © 2006 John Wiley & Sons, Ltd. [source] Allowing for redundancy and environmental effects in estimates of home range utilization distributionsENVIRONMETRICS, Issue 1 2005W. G. S. Hines Abstract Real location data for radio tagged animals can be challenging to analyze. They can be somewhat redundant, since successive observations of an animal slowly wandering through its environment may well show very similar locations. The data set can possess trends over time or be irregularly timed, and they can report locations in environments with features that should be incorporated to some degree. Also, the periods of observation may be too short to provide reliable estimates of characteristics such as inter-observation correlation levels that can be used in conventional time-series analyses. Moreover, stationarity (in the sense of the data being generated by a source that provides observations of constant mean, variance and correlation structure) may not be present. This article considers an adaptation of the kernel density estimator for estimating home ranges, an adaptation which allows for these various complications and which works well in the absence of exact (or precise) information about correlation structure and parameters. Modifications to allow for irregularly timed observations, non-stationarity and heterogeneous environments are discussed and illustrated. Copyright © 2004 John Wiley & Sons, Ltd. [source] Alcohol consumption and liver cirrhosis mortality with and without mention of alcohol,the case of CanadaADDICTION, Issue 9 2003Mats Ramstedt ABSTRACT Aims, To analyse post-war variations in per capita alcohol consumption in relation to gender-specific liver cirrhosis mortality in Canadian provinces and to assess the extent to which alcohol bears a different relation to cirrhosis deaths with mention of alcohol (alcoholic cirrhosis) compared to cirrhosis deaths without mention of alcohol (non-alcoholic cirrhosis). Data and method, Annual liver cirrhosis mortality rates by 5-year age groups were converted into gender-specific and age-adjusted mortality rates. Outcome measures included total cirrhosis,the conventional measure of liver cirrhosis,alcoholic cirrhosis and non-alcoholic cirrhosis. Per capita alcohol consumption was measured by alcohol sales and weighted with a 10-year distributed lag model. A graphical analysis was used to examine the regional relationship and the Box,Jenkins technique for time-series analysis was used to estimate the temporal relationship. Findings, Geographical variations in alcohol consumption corresponded to variations in total liver cirrhosis and particularly alcoholic cirrhosis, whereas non-alcoholic cirrhosis rates were not associated geographically with alcohol consumption. In general, for all provinces, time-series analyses revealed positive and statistically significant effects of changes in alcohol consumption on cirrhosis mortality. In Canada at large, a 1-litre increase in per capita consumption was associated with a 17% increase in male total cirrhosis rates and a 13% increase in female total cirrhosis rates. Alcohol consumption had a stronger impact on alcoholic cirrhosis, which increased by fully 30% per litre increase in alcohol per capita for men and women. Although the effect on the non-alcoholic cirrhosis rate was weaker (12% for men and 7% for women) it was nevertheless statistically significant and suggests that a large proportion of these deaths may actually be alcohol-related. Conclusions, Some well-established findings in alcohol research were confirmed by the Canadian experience: per capita alcohol consumption is related closely to death rates from liver cirrhosis and alcohol-related deaths tend to be under-reported in mortality statistics. [source] Marital Research in the 20th Century and a Research Agenda for the 21st CenturyFAMILY PROCESS, Issue 2 2002John M. Gottman Ph.D. In this article we review the advances made in the 20th century in studying marriages. Progress moved from a self-report, personality-based approach to the study of interaction in the 1950s, following the advent of general systems theory. This shift led, beginning in the 1970s, to the rapid development of marital research using a multimethod approach. The development of more sophisticated observational measures in the 1970s followed theorizing about family process that was begun in the decade of the 1950s. New techniques for observation, particularly the study of affect and the merging of synchronized data streams using observational and self-report perceptual data, and the use of sequential and time-series analyses produced new understandings of process and power. Research in the decades of the 1980s and 1990s witnessed the realization of many secular changes in the American family, including the changing role of women, social science's discovery of violence and incest in the family, the beginning of the study of cultural variation in marriages, the expansion of the measurement of marital outcomes to include longevity, health, and physiology (including the immune system), and the study of co-morbidities that accompany marital distress. A research agenda for the 21st century is then described. [source] Nutritional factors affecting serum phenylalanine concentration during pregnancy for identical twin mothers with phenylketonuriaACTA PAEDIATRICA, Issue 8 2000C Fox The effect of energy, protein, fat, and phenylalanine on serum phenylalanine concentrations during pregnancy for a set of identical twins with phenylketonuria (PKU) was examined. Blood samples were collected one to two times per week. The subjects completed a 3-d food record prior to each blood collection. The effect of the factors on serum phenylalanine levels was evaluated statistically using time-series analysis. Dietary intakes of the nutrients evaluated were similar for the subjects. For one subject, there were highly significant effects of energy, protein, and fat on serum phenylalanine levels. In contrast, these nutrients had no significant effect on serum phenylalanine for the other subject. Dietary phenylalanine had no significant effect on serum phenylalanine for either twin. Conclusions: There was no effect of phenylalanine intake and no consistent effect of energy, protein, or fat on serum phenylalanine. Other dietary or environmental factors or a combination of factors may impact serum phenylalanine levels of pregnant women with PKU. [source] Potential impacts on the incidence of fatal heroin-related overdose in Western Australia: a time-series analysisDRUG AND ALCOHOL REVIEW, Issue 4 2002KIM HARGREAVES Abstract In response to the rising concerns about the rate of heroin-related fatalities, overdose prevention campaigns, run by both users' organizations and government agencies, have been implemented in a number of states across Australia. In Western Australia (WA) in mid-1997, various overdose prevention initiatives were implemented. These included the implementation of a protocol limiting police presence at overdose events; the commencement of naloxone administration by ambulance staff; and the establishment of the Opiate Overdose Prevention Strategy (OOPS) which provided follow-up for individuals treated for overdose in emergency departments. This paper reports the results of a multiple linear regression analysis of 60 months of time-series data, both prior to and following the implementation of these interventions, to determine their impact on the number of fatal heroin overdoses in WA. The model employed in the analysis controlled for changes over time in proxy indicators of use and community concerns about heroin, as well as market indicators. The results suggest that, although the interventions implemented have managed to reduce the expected number of fatalities, they have become less successful in doing so as time passes. This has implications for both existing and potential interventions to reduce fatal heroin-related overdose. [source] Impacts of federal precursor chemical regulations on methamphetamine arrestsADDICTION, Issue 4 2005James K. Cunningham ABSTRACT Aims The US government regulated precursor chemicals, ephedrine and pseudoephedrine, multiple times to limit methamphetamine production/availability and thus methamphetamine problems. Research has found that the regulations reduced methamphetamine hospital admissions, but authors have argued that other problems were unaffected. This study examines whether the regulations impacted methamphetamine arrests. Design ARIMA-intervention time-series analysis with control series. Setting California (1982,2001). Measurements Dependent variable series: monthly methamphetamine arrests. Control series: monthly marijuana arrests and cocaine/heroin arrests. Interventions Bulk powder ephedrine and pseudoephedrine: regulated November 1989. Products containing ephedrine as the single active medicinal ingredient: regulated August 1995. Pseudoephedrine products: regulated October 1997. Large-scale producers used ephedrine and pseudoephedrine in these forms. Ephedrine combined with other active medicinal ingredients (e.g. various cold medicines),used mainly by small-scale producers: regulated October 1996. Findings The regulation targeting small-scale producers (1996) had no significant impact. In contrast, methamphetamine arrests stopped rising and dropped 31% to 45% each of the three times precursor chemicals used by large-scale producers were regulated. Within 3 years of the bulk powder regulation (1989) and again within 2 years of the ephedrine single ingredient regulation (1995), arrests fully rebounded. During the 4 years following the last regulation (pseudoephedrine products, 1997) arrests only partially rebounded. These effects parallel those reported on hospital admissions. The control series were generally unaffected. Conclusions Precursor regulations targeting large-scale producers impacted methamphetamine arrests, a criminal justice problem, much as they impacted the public health problem of methamphetamine hospital admissions. Ongoing research is needed to determine whether these problems eventually fully rebound from the last regulation. [source] Alcohol consumption and liver cirrhosis mortality with and without mention of alcohol,the case of CanadaADDICTION, Issue 9 2003Mats Ramstedt ABSTRACT Aims, To analyse post-war variations in per capita alcohol consumption in relation to gender-specific liver cirrhosis mortality in Canadian provinces and to assess the extent to which alcohol bears a different relation to cirrhosis deaths with mention of alcohol (alcoholic cirrhosis) compared to cirrhosis deaths without mention of alcohol (non-alcoholic cirrhosis). Data and method, Annual liver cirrhosis mortality rates by 5-year age groups were converted into gender-specific and age-adjusted mortality rates. Outcome measures included total cirrhosis,the conventional measure of liver cirrhosis,alcoholic cirrhosis and non-alcoholic cirrhosis. Per capita alcohol consumption was measured by alcohol sales and weighted with a 10-year distributed lag model. A graphical analysis was used to examine the regional relationship and the Box,Jenkins technique for time-series analysis was used to estimate the temporal relationship. Findings, Geographical variations in alcohol consumption corresponded to variations in total liver cirrhosis and particularly alcoholic cirrhosis, whereas non-alcoholic cirrhosis rates were not associated geographically with alcohol consumption. In general, for all provinces, time-series analyses revealed positive and statistically significant effects of changes in alcohol consumption on cirrhosis mortality. In Canada at large, a 1-litre increase in per capita consumption was associated with a 17% increase in male total cirrhosis rates and a 13% increase in female total cirrhosis rates. Alcohol consumption had a stronger impact on alcoholic cirrhosis, which increased by fully 30% per litre increase in alcohol per capita for men and women. Although the effect on the non-alcoholic cirrhosis rate was weaker (12% for men and 7% for women) it was nevertheless statistically significant and suggests that a large proportion of these deaths may actually be alcohol-related. Conclusions, Some well-established findings in alcohol research were confirmed by the Canadian experience: per capita alcohol consumption is related closely to death rates from liver cirrhosis and alcohol-related deaths tend to be under-reported in mortality statistics. [source] SEASONAL CYCLES OF ALLOZYME-BY-CHROMOSOMAL-INVERSION GAMETIC DISEQUILIBRIUM IN DROSOPHILA SUBOBSCURAEVOLUTION, Issue 4 2003Francisco Rodríguez-Trelles Abstract Allozyme loci are frequently found non randomly associated to the chromosomal inversions in which they are included in Drosophila. Two opposite views compete to explain strong allozyme-by-inversion gametic disequilibria: they result from natural selection or, conversely, merely represent remnants of associations accidentally established at the origin of inversions. Empirical efforts aimed at deciding between adaptive and historical scenarios have focused on the spatial distribution of disequilibria. Yet, the evolutionary significance of these associations remains uncertain. I report here the results of a time-series analysis of the seasonal variation of alleles at six allozyme loci (Acph, Lap, Pept-1, Ao, Mpi, and Xdh) in connection with the O chromosomal polymorphisms of D. subobscura. The findings were: (1) in the segment I of the O chromosome, Lap and Pept-1 allozymes changed seasonally in a cyclical fashion within the ST gene arrangement, but they changed erratically within the 3+4 gene configuration; (2) the frequencies of Lap111 and Pept-10,40 within ST dropped to their lowest values in early and late summer, respectively, when the seasonal level of the ST arrangement is lowest. Furthermore, Lap1,11 and Pept-10,40 covary with ST only within these seasons, yet in a fashion inconsistent with these alleles having a major influence on the dynamics of the inversion; (3) seasonal cycling of alleles within inversions were not detected at Acph, Ao, Mpi, and Xdh, yet these loci are nearly monomorphic at the study population, and/or their sampled series were shorter than those for Lap and Pept-1; and (4) simply monitoring allozyme frequencies separately for each inversion proved to be superior, for evidencing the seasonal cycles of the disequilibria, to the use of the D' coefficient of association. Observed seasonal cycles of allozymes within inversions likely reflect natural selection. [source] 24-Hour Distribution of Migraine AttacksHEADACHE, Issue 1 2008Karl Alstadhaug MD Background., It is a widespread opinion that migraine attacks arise more frequently in the morning and that circadian rhythms may be responsible for the temporal pattern in migraine. However, only one small prospective study has previously been published on this topic. Objective., To investigate circadian variation in migraine. Method., Eighty-nine females in fertile age who had participated in a previous questionnaire-based study volunteered to prospectively record in detail every migraine attack for 12 consecutive months. We reviewed all diary entries covering the period from March 2004 through April 2005, and did time-series analysis. Results., Fifty-eight patients had complete recordings over the 12 months and 26 completed the diaries for 1,11 months. Three patients were excluded due to missing data and 2 patients were excluded due to chronic migraine or medication-overuse headache. A total of 2314 attacks were experienced, in average 27.5 per patient (range 1,75). By fitting a sine curve to the data there was a harmonic trend with a peak around 13.40 and the peak/low ratio was 25.6 (95% CI: 8.3,78.6). Conclusion., The main finding in our study is that migraine attacks tend to recur in a harmonic 24-hour cyclic manner with a peak around the middle of the day and that there is no difference between migraine with aura and migraine without aura regarding this. [source] Changes in Regional Variation of Medicare Home Health Care Utilization and Service Mix for Patients Undergoing Major Orthopedic Procedures in Response to Changes in Reimbursement PolicyHEALTH SERVICES RESEARCH, Issue 4 2009John D. FitzGerald Background. Significant variation in regional utilization of home health (HH) services has been documented. Under Medicare's Home Health Interim and Prospective Payment Systems, reimbursement policies designed to curb expenditure growth and reduce regional variation were instituted. Objective. To examine the impact of Medicare reimbursement policy on regional variation in HH care utilization and type of HH services delivered. Research Design. We postulated that the reimbursement changes would reduce regional variation in HH services and that HH agencies would respond by reducing less skilled HH aide visits disproportionately compared with physical therapy or nursing visits. An interrupted time-series analysis was conducted to examine regional variation in the month-to-month probability of HH selection, and the number of and type of visits among HH users. Subjects. A 100 percent sample of all Medicare recipients undergoing either elective joint replacement (1.6 million hospital discharges) or surgical management of hip fracture (1.2 million hospital discharges) between January 1996 and December 2001 was selected. Results. Before the reimbursement changes, there was great variability in the probability of HH selection and the number of HH visits provided across regions. In response to the reimbursement changes, though there was little change in the variation of probability of HH utilization, there were marked reductions in the number and variation of HH visits, with greatest reductions in regions with highest baseline utilization. HH aide visits were the source of the baseline variation and accounted for the majority of the reductions in utilization after implementation. Conclusions. The HH interim and prospective payment policies were effective in reducing regional variation in HH utilization. [source] Six-week postpartum maternal depressive symptoms and 4-month mother,infant self- and interactive contingency,INFANT MENTAL HEALTH JOURNAL, Issue 5 2008Beatrice Beebe Associations of 6-week maternal depressive symptoms [Center for Epidemiological Studies Depression Scale (CES-D)] with 4-month mother,infant self- and interactive contingency patterns during face-to-face play were investigated in 132 dyads. Self- and interactive contingency (auto- and lagged cross-correlation, respectively) were assessed by multilevel time-series analysis. Infant and mother gaze, facial and vocal affect, touch, and spatial orientation behaviors were coded second-by-second from split-screen videotape, and a multimodal measure of facial,visual "engagement" was constructed, generating nine modality pairings. With higher CES-D, the self-contingency of both partners was lowered in most modalities. With higher CES-D, interactive contingency values were both heightened (in some modalities) and lowered (in others), varying by partner. These results are consistent with an optimal midrange model. With higher CES-D, interactive contingency showed the following patterns: (a) Mothers and their infants had a reciprocal orientational sensitivity; (b) mothers and infants manifested a reciprocal intermodal discordance in attention versus affect coordination, lowering gaze coordination, but heightening affective coordination; (c) infants heightened, but mothers lowered, touch coordination with partner touch,an "infant approach,mother withdraw" touch pattern. Nonlinear analyses indicated that altered self- and interactive contingency were similar at both the low ("denial") as well as the high ("endorsement") poles of depressive symptoms, in half the findings. These complex, multimodal findings define different aspects of communication disturbance, with relevance for therapeutic intervention. [source] Nonlinear multiple regression methods: a survey and extensionsINTELLIGENT SYSTEMS IN ACCOUNTING, FINANCE & MANAGEMENT, Issue 1 2010Kenneth O. Cogger Abstract This paper reviews some nonlinear statistical procedures useful in function approximation, classification, regression and time-series analysis. Primary emphasis is on piecewise linear models such as multivariate adaptive regression splines, adaptive logic networks, hinging hyperplanes and their conceptual differences. Potential and actual applications of these methods are cited. Software for implementation is discussed, and practical suggestions are given for improvement. Examples show the relative capabilities of the various methods, including their ability for universal approximation. Copyright © 2010 John Wiley & Sons, Ltd. [source] Effectiveness of a Media Campaign to ReduceJOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 3 2006Traffic Crashes Involving Young Drivers This article describes the evaluation of a 4-1/2-month multimedia traffic-safety campaign that targeted young drivers in northeastern Tennessee. Discussion groups with teenagers provided the basis for public-service announcements (TV, radio, and billboard), which were developed specifically for this intervention. To determine the impact on crash frequencies among drivers 16,19 years old, baseline, intervention, and follow-up crash data were obtained from statistics maintained by the state. A time-series analysis of these data indicated that during the intervention period, there was a 21.6% decrease in crashes for which 16,19-year-old drivers were at fault, whereas a control location in southeastern Tennessee exhibited no significant change. [source] Population Trends in BMD Testing, Treatment, and Hip and Wrist Fracture Rates: Are the Hip Fracture Projections Wrong?JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2005Susan B Jaglal PhD Abstract A worldwide epidemic of hip fractures has been predicted. Time trends in BMD testing, bone-sparing medications and hip and wrist fractures in the province of Ontario, Canada, were examined. From 1996 to 2001, BMD testing and use of bone-sparing medications increased each year, whereas despite the aging of the population, wrist and hip fracture rates decreased. Introduction: If patients with osteoporosis are being diagnosed and effective treatments used with increasing frequency in the population, rates of hip and wrist fractures will remain stable or possibly decrease. We report here time trends in BMD testing, prescriptions for bone-sparing medications, hip and wrist fracture rates, and population projections of fracture rates to 2005 in the province of Ontario, Canada. Materials and Methods: Ontario residents have universal access to Medicare. To examine time trends in BMD testing, all physician claims for DXA from 1992 to 2001 were selected from the Ontario Health Insurance Plan (OHIP) database. Trends in prescribing were examined from 1996 to 2003 using data from the Ontario Drug Benefit plan, which provides coverage to persons ,65 years of age. Actual numbers of hip and wrist fractures were determined for 1992-2000 and population projections for 2001-2005 using time-series analysis. Wrist fractures were identified in the OHIP database and hip fractures through hospital discharge abstracts. Results: From 1992 to 2001, the number of BMD tests increased 10-fold. There has been a steady increase in the number of persons filling prescriptions for antiresorptives (12,298 in 1996 to 225,580 in 2003) and the majority were for etidronate. For women, the rate of decline for wrist fractures is greater than that for hip fractures. The rate of hip fracture was fairly constant around 41 per 10,000 women ,50 years between 1992 and 1996. In 1997, the hip fracture rate began to decrease, and the population projections suggest that this downward trend will continue to a rate of 33.1 per 10,000 in 2005. Conclusions: Our findings suggest that fracture rates may be on the decline, despite the aging of the population, because of increased patterns of diagnosis and treatment for osteoporosis. [source] Oral quinolones in hospitalized patients: an evaluation of a computerized decision support intervention,JOURNAL OF INTERNAL MEDICINE, Issue 4 2004T. Hulgan Abstract. Objective., To determine whether a computerized decision support system could increase the proportion of oral quinolone antibiotic orders placed for hospitalized patients. Design., Prospective, interrupted time-series analysis. Setting., University hospital in the south-eastern United States. Subjects., Inpatient quinolone orders placed from 1 February 2001 to 31 January 2003. Intervention., A web-based intervention was deployed as part of an existing order entry system at a university hospital on 5 February 2002. Based on an automated query of active medication and diet orders, some users ordering intravenous quinolones were presented with a suggestion to consider choosing an oral formulation. Main outcome measure., The proportion of inpatient quinolone orders placed for oral formulations before and after deployment of the intervention. Results., There were a total of 15 194 quinolone orders during the study period, of which 8962 (59%) were for oral forms. Orders for oral quinolones increased from 4202 (56%) before the intervention to 4760 (62%) after, without a change in total orders. In the time-series analysis, there was an overall 5.6% increase (95% CI 2.8,8.4%; P < 0.001) in weekly oral quinolone orders due to the intervention, with the greatest effect on nonintensive care medical units. Conclusions., A web-based intervention was able to increase oral quinolone orders in hospitalized patients. This is one of the first studies to demonstrate a significant effect of a computerized intervention on dosing route within an antibiotic class. This model could be applied to other antibiotics or other drug classes with good oral bioavailability. [source] Air pollution and hospitalization for venous thromboembolic disease in ChileJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2010R. E. DALES See also Mannucci PM. Fine particulate: it matters. This issue, pp 659,61; Bonzini M, Tripodi A, Artoni A, Tarantini L, Marinelli B, Bertazzi PA, Apostoli P, Baccarelli A. Effects of inhalable particulate matter on blood coagulation. This issue, pp 662,8. Summary.,Background:,Ambient air pollution is a risk factor for stroke and myocardial infarction, possibly because of alterations in coagulation that influence the arterial circulation. Whether air pollution influences diseases associated with peripheral venous thrombogenesis remains largely unknown. Objectives: To determine the association between air pollution and venous thromboembolic disease (VTE) in a sample of the general population. Methods: A time-series analysis was used to test the association between daily air pollution and VTE hospitalizations in Santiago between 2001 and 2005. Results were adjusted for long-term trends, day of the week and average daily humidex. Results: From a population of 5.4 million, there were, on average, 2.3 admissions for VTE per day. Pooled estimates of relative risk (RR) [95% confidence interval (CI)] of hospitalization for venous disease were: 1.07 (1.05, 1.09) for a 58.4 p.p.b. increase in ozone (O3); 1.06 (1.02, 1.09) for a 5.85 p.p.b. increase in sulphur dioxide (SO2); 1.08 (1.03, 1.12) for a 29.25 ,g/m3 increase in nitrogen dioxide (NO2); and 1.05 (1.03, 1.06) for a 20.02 ,g/m3 increase in particulate matter , 2.5 ,m in mean aerodynamic diameter (PM2.5). For pulmonary embolism (PE) results were: 1.10 (1.07, 1.13) for O3; 1.05 (1.02, 1.08) for SO2; 1.07 (1.04, 1.09) for NO2; and 1.05(1.03, 1.06) for PM2.5, respectively. Conclusion: Air pollution appears to be a risk factor for venous thrombosis and PE, a disease with a significant fatality rate. [source] Automatic identification of seasonal transfer function models by means of iterative stepwise and genetic algorithmsJOURNAL OF TIME SERIES ANALYSIS, Issue 1 2008Monica Chiogna Abstract., In this article, we introduce an automatic identification procedure for transfer function models. These models are commonplace in time-series analysis, but their identification can be complex. To tackle this problem, we propose to couple a nonlinear conditional least-squares algorithm with a genetic search over the model space. We illustrate the performances of our proposal by examples on simulated and real data. [source] Efficient use of higher-lag autocorrelations for estimating autoregressive processesJOURNAL OF TIME SERIES ANALYSIS, Issue 3 2002LAURENCE BROZE The Yule,Walker estimator is commonly used in time-series analysis, as a simple way to estimate the coefficients of an autoregressive process. Under strong assumptions on the noise process, this estimator possesses the same asymptotic properties as the Gaussian maximum likelihood estimator. However, when the noise is a weak one, other estimators based on higher-order empirical autocorrelations can provide substantial efficiency gains. This is illustrated by means of a first-order autoregressive process with a Markov-switching white noise. We show how to optimally choose a linear combination of a set of estimators based on empirical autocorrelations. The asymptotic variance of the optimal estimator is derived. Empirical experiments based on simulations show that the new estimator performs well on the illustrative model. [source] BIG CITY, BIG TURNOUT?JOURNAL OF URBAN AFFAIRS, Issue 1 2007ELECTORAL PARTICIPATION IN AMERICAN CITIES ABSTRACT:,This article seeks to describe and explain variation in voter turnout in American big city municipal elections using data from 332 mayoral elections in 38 large U.S. cities over 25 years. In my cross-sectional time-series analysis of turnout in mayoral elections, I find that city-level demographic factors are only weakly correlated with turnout. By contrast, institutional and campaign factors explain much of the variation. The effect of Progressive era reforms on depressing turnout is greatest in the most competitive elections. I conclude by discussing the implication of the overall downward trend in turnout and changes cities can make to increase participation. [source] Negotiating Globalization: Global Scripts and Intermediation in the Construction of Asian Insolvency RegimesLAW & SOCIAL INQUIRY, Issue 3 2006Bruce G. Carruthers This article draws from a larger research project on the globalization of bankruptcy law that includes (1) a time-series analysis of all bankruptcy reforms worldwide from 1973 to 1998; (2) participation observation, several hundred interviews and documentary analysis of international financial institutions (IMF, World Bank, Asian Development Bank, European Bank for Reconstruction and Development), international professional associations (International Bar Association, International Federation of Insolvency Practitioners), and world governance organizations (OECD, U.N. Commission on International Trade Law); and (3) case studies of Indonesia, Korea, and China. The globalization of law is a negotiated process. Our research on international organizations and case studies of China, Indonesia, and South Korea indicates that negotiation of the global/local relationship varies by the vulnerability of a country to global forces. Nation-states vary (1) in their balance of power vis-à-vis global actors; and (2) in their social and cultural distance from the global. Yet even where the global/local gap is wide and the asymmetry of power is pronounced, local responses to global pressures are negotiated as much as imposed. Negotiating globalization relies on direct and mediated interactions by several types of intermediaries who translate global scripts into four kinds of outcomes. The impact of intermediaries in this process varies by the phase of the reform in which they participate. Finally, globalizing law proceeds through recursive cycles of lawmaking and law implementation. [source] A network analysis of the single nucleotide polymorphisms in acute allergic diseasesALLERGY, Issue 1 2010J. Renkonen Abstract Background:, Genetics of acute allergies has focused on identifying single nucleotide polymorphisms (SNPs) within genes relevant in the pathogenesis. In this study, we begin a systems biology analysis of the interconnectivity and biological functions of these genes, their transcripts and their corresponding proteins. Methods:, The literature (Pubmed) was searched for SNPs within genes relevant in acute allergic diseases. The SNP-modified genes were converted to corresponding proteins and their protein,protein interactions were searched from six different databases. This interaction network was analysed with annotated vocabularies (ontologies), such as Gene Ontology, Reactome and Nature pathway interaction database. Time-series transcriptomics was performed with nasal epithelial cells obtained from allergic patients and their healthy control subjects. Results:, A total of 39 genes with SNPs related to acute allergic diseases were found from a literature search. The corresponding proteins were then hooked into a large protein,protein interaction network with the help of various databases. Twenty-five SNP-related proteins had more than one interacting protein and a network contained 95 proteins, and 182 connections could be generated. This network was 10-fold enriched with protein kinases and proteins involved in the host,virus interaction compared with background human proteome. Finally, eight of the 95 nodes on our network displayed nasal epithelial transcriptomal regulation in a time-series analysis collected from birch allergic patients during the spring pollen season. Conclusions:, Signal transduction with special reference to host,virus interactions dominated in the allergy-related protein interaction network. Systems level analysis of allergy-related mutation can provide new insights into pathogenetic mechanisms of the diseases. [source] Identifying environmental signals from population abundance data using multivariate time-series analysisOIKOS, Issue 11 2009Masami Fujiwara Individual organisms are affected by various natural and anthropogenic environmental factors throughout their life history. This is reflected in the way population abundance fluctuates. Consequently, observed population dynamics are often produced by the superimposition of multiple environmental signals. This complicates the analysis of population time-series. Here, a multivariate time-series method called maximum autocorrelation factor analysis (MAFA) was used to extract underlying signals from multiple population time series data. The extracted signals were compared with environmental variables that were suspected to affect the populations. Finally, a simple multiple regression analysis was applied to the same data set, and the results from the regression analysis were compared with those from MAFA. The extracted signals with MAFA were strongly associated with the environmental variables, suggesting that they represent environmental factors. On the other hand, with the multiple regression analysis, one of the important signals was not identifiable, revealing the shortcoming of the conventional approach. MAFA summarizes data based on their lag-one autocorrelation. This allows the identification of underlying signals with a small effect size on population abundance during the observation. It also uses multiple time series collected in parallel; this enables us to effectively analyze short time series. In this study, annual spawning adult counts of Chinook salmon at various locations within the Klamath Basin, California, were analyzed. [source] Does Earmarked Revenue Provide Property Tax Relief?PUBLIC BUDGETING AND FINANCE, Issue 4 2008Long-Term Budgetary Effects of Georgia's Local Option Sales Tax This study examines the long-term effects of the 1% General-purpose Local Option Sales Tax (LOST) on the level of property tax in Georgia counties with a pooled interrupted time-series analysis. The LOST has been earmarked for property tax relief in Georgia counties since 1976, but debates remain on whether the proceeds have been used as additional revenues. We find that the adoption of LOST brought short-term property tax relief but not long-term property tax reduction. The result suggests that long-term property tax relief would not be realized by earmarked revenue without careful policy design to safeguard fungibility. [source] The crime drop in comparative perspective: the impact of the economy and imprisonment on American and European burglary ratesTHE BRITISH JOURNAL OF SOCIOLOGY, Issue 3 2009Richard Rosenfeld Abstract Influential statements on recent American crime reductions maintain that the crime drop was confined to the USA. Yet other research has revealed comparable crime decreases in Europe. We suggest that the USA and European crime declines occurred in tandem because they were both brought about by upturns in the economy. In light of US research showing crime reductions resulting from growth in imprisonment, we also examine the possibility that rising imprisonment rates reduced European crime rates. We test these hypotheses in a pooled cross-sectional time-series analysis of burglary rates in the USA and nine European nations between 1993 and 2006. The results indicate that burglary declines in the US and Europe were associated with rising consumer confidence. By contrast, imprisonment appears to be significantly related to burglary rates only after unusual policy interventions, such as Italy's 2006 clemency measure that dramatically reduced the size of its prison population. We interpret these findings as reflecting the structural similarity and economic integration of the world's developed nations and the uneven convergence in US and European punishment policies. [source] An Empirical Analysis of the Efficiency of the Osaka Rice Market During Japan's Tokugawa EraTHE JOURNAL OF FUTURES MARKETS, Issue 9 2001Shigeyuki Hamori The Dojima Rice Market in Osaka was the first futures market in the world, and an influential role model for modern futures markets. This study examines the efficiency of the original futures market by applying time-series analysis to data on futures prices from Japan's Tokugawa era (1603,1867). The results of cointegration tests indicate that the futures market functioned efficiently during the first sample period (1763,1780), but its efficiency declined during the second sample period (1851,1864). © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:861,874, 2001 [source] Time-series photometric spot modelling , VI.ASTRONOMISCHE NACHRICHTEN, Issue 3 2003A new computer code, its application to 23 years of photometry of the active giant IM Pegasi Abstract We present and apply a new computer program named SpotModeL to analyze single and multiple bandpass photometric data of spotted stars. It is based on the standard analytical formulae from Budding and Dorren. The program determines the position, size, and temperature of up to three spots by minimizing the fit residuals with the help of the Marquardt-Levenberg non-linear least-squares algorithm. We also expand this procedure to full time-series analysis of differential data, just as real observations would deliver. If multi-bandpass data are available, all bandpasses can be treated simultaneously and thus the spot temperature is solved for implicitly. The program may be downloaded and used by anyone. In this paper, we apply our code to an ,23 year long photometric dataset of the spotted RS CVn giant IM Peg. We extracted and modelled 33 individual light curves, additionally, we fitted the entire V dataset in one run. The resulting spot parameters reflect the long term light variability and reveal two active longitudes on the substellar point and on the antipode. The radius and longitude of the dominant spot show variations with 29.8 and 10.4 years period, respectively. Our multicolour data suggests that the spot temperature is increasing with the brightening of the star. The average spot temperature from V, IC is 3550 ± 150 K or approximately 900 K below the effective temperature of the star. [source] THE RELATIONSHIP BETWEEN CAPITAL STOCK, UNEMPLOYMENT AND WAGES IN NINE EMU COUNTRIESBULLETIN OF ECONOMIC RESEARCH, Issue 2 2007Philip Arestis E00; E22; E24 ABSTRACT The focus of this paper is to investigate the importance of the capital stock in the determination of wages and unemployment in a range of EMU countries and to compare the results across countries. A time-series analysis is conducted in the case of nine euro area countries, which were selected solely on the basis of data availability and consistency: Austria, Belgium, Finland, France, Germany, Italy, Ireland, the Netherlands and Spain. The paper begins with a short review of the literature on capital stock and unemployment, before it deals with the theoretical model. This is followed by estimation and testing of the theoretical model put forward, using both time-series and panel data. The results are supportive of the main hypothesis of the paper: capital stock is an important determinant of unemployment and wages in the countries considered for the purposes of the paper. [source] | ||||||||||||||||||||||||||||