Chi-square Calculations Research Articles

From psychoanalysis to epidemiology: autobiographical notes

From psychoanalysis to epidemiology: autobiographical notes

Influenza Vaccination among Emergency Medical Services and Emergency Department Personnel

Objectives. Influenza vaccination has long been recommended for health care workers, but vaccination rates among this group have been low. Data on emergency medical services (EMS) personnel's vaccination status have not been published. This study compared self-reported vaccination rates and barriers among EMS and emergency department (ED) personnel. Methods. We conducted a cross-sectional survey of full-time EMS providers servicing metropolitan Rochester, New York, and a convenience sample of ED personnel in an academic medical center in Rochester, New York. Surveys, completed during July and August 2006, focused on influenza vaccination status for the 2005–2006 season and opinions regarding the vaccination. Immunization rates of EMS providers and ED personnel were compared using the chi-square calculation. Results. Surveys were completed by 128 EMS providers (100% of eligible) and 128 ED personnel (100% of approached). Among EMS providers, 27 of 128 (21%; 95% confidence interval [CI] 14%–29%), and among ED personnel, 83 of 128 (65%; 95% CI 56%–73%) reported receiving an influenza vaccination in the preceding year (p < 0.001). Among interventions that could lead to an increase in influenza vaccination, the most commonly chosen by EMS providers and ED personnel alike were “no waiting” vaccination at work (71% and 62%, respectively) and free vaccination (59% and 50%, respectively). When asked about important factors in the decision whether to get an influenza vaccination the following season, the most common responses were frequency of exposure (71%, 69%) and concern about secondarily exposing family members (62%, 60%). Conclusion. EMS providers reported low influenza vaccination levels in 2005–2006, even as compared with ED personnel. This failure to receive vaccination poses potential risk to the workers themselves and their patients. Resolution of reported barriers could lead to higher vaccination rates.

Generation of pornographic blacklist and its incremental update using an inverse chi-square based method

This study presented an inverse chi-square based web content classification system that works along with an incremental update mechanism for incremental generation of pornographic blacklist. The proposed system, as indicated from the experimental results, can classify bilingual (English and Chinese) web pages at an average precision rate of 97.11%; while maintaining a favorably low false positive rate. Such satisfactory performance was obtained under a cost-effective parameter configuration used in inverse chi-square calculations. The proposed incremental update mechanism operates on the linking structure of pornographic hubs to locate newly added pornographic sites. The resulting blacklist has been empirically verified to be comparatively responsive to the growth dynamics of pornography sites than three public domain blacklists.

The Rosenzweig Picture-Frustration Study “Extra-Aggression” Score as an Indicator in Cognitive Restructuring Therapy for Male Perpetrators of Domestic Violence

It was hypothesized that male perpetrators of domestic violence in the early stages of a 1-year process of cognitive restructuring therapy would manifest on the Rosenzweig Picture-Frustration Study higher levels of extra-aggressiveness than in later stages of the therapy process. A sample of male batterers in the process of treatment took the Rosenzweig instrument. The resulting responses were rated by trained scorers. Chi-square calculations revealed that batterers in the first quarter of treatment manifested Rosenzweig responses indicative of extra-aggressiveness, whereas in the fourth quarter, batterers manifested Rosenzweig responses indicative of im-aggression. The data are discussed relative to implications for domestic violence treatment and the use of the Rosenzweig instrument as an index of treatment progress.

255 PREIMPLANTATION DEVELOPMENT AND EXPRESSION OF Bax AND Hsp-70 GENES IN BOVINE EMBRYOS PRODUCED FROM OOCYTES MATURED IN CHEMICALLY DEFINED IVM MEDIUM WITHOUT GONADOTROPHINS

The culture environment affects both the maternal and the embryonic expression of genes, and is likely to alter both oocyte and embryo developmental competence. Search for better and less variable culture conditions simulating the in vivo environment has led to the development of defined culture media, with lower negative impact on the molecular reprogramming of oocytes and embryos. This study aimed to evaluate the embryo development and relative expression of Hsp-70 and Bax transcripts in bovine blastocysts produced from oocytes matured in chemically defined IVM medium supplemented with insulin-like growth factor (IGF)-I, insulin, and polyvinyl alcohol (PVA) or polyvinylpyrrolidone 40 (PVP) without FSH and LH. Immature cumulus–oocyte complexes (COCs) from slaughtered cows were matured for 24 h in α-MEM plus IGF-1 and insulin and supplemented with 0.1% PVA (treatment 1; n = 410) or 0.1% PVP (treatment 2; n = 350). Neither FSH nor LH was used in both treatments. The control group consisted of COCs matured in TCM plus FSH and 10% estrous cow serum (n = 400). In vitro fertilization took place in Fert-Talp droplets for 22 h. Presumptive zygotes were co-cultured with cumulus cells in CR2aa supplemented with 10% fetal calf serum under mineral oil in a humidified atmosphere of 5% CO2 at 38.5�C. Preimplantation embryo development was determined by cleavage, blastocyst, and hatching rates. For RNA extraction, blastocysts at Day 8 post-fertilization were frozen in liquid nitrogen and subsequently thawed. Total RNA extraction was performed using Rneasy Micro kit (Qiagen, Valencia, CA, USA) and first strand synthesized using Superscript III First Strand Synthesis kit (Invitrogen, Chicago, IL, USA). Relative quantification was performed in duplicate using real-time PCR (ABI Prism 7000 Applied Biosystem, Foster City, CA, USA); reactions consisted of a mixture of iTaq SYBR Green Supermix with ROX (Bio-Rad, Waltham, MA, USA) with cDNA equivalent to 0.8 embryos and specific primers for Hsp-70 and Bax genes, using as endogenous reference the expression of H2a gene. Data of embryo development were analyzed by chi-square test and calculations of relative quantification were performed by REST� (Relative Expression Software Tool; Pfaffl et al. 2002 Nucl. Acids Res. 30, e36), using the value found in the control group as calibrator. Cleavage rate was higher (P &lt; 0.05) for the control group (67%) than for treatments 1 (54%) and 2 (59%). Nevertheless, there was no difference (P &gt; 0.05) in blastocyst (40.2%, 45.0%, and 43.5%) and hatching (78%, 77%, and 75%) rates among treatments 1 and 2 and the control group, respectively. Similarly, no difference (P &gt; 0.05) in relative expression of Hsp-70 and Bax transcripts (0.69 � 0.69 and 0.53 � 0.32 for treatment 1, and 1.08 � 0.75 and 0.70 � 0.47 for treatment 2) in comparison to the calibrator group was detected. These results show that bovine oocytes can be matured in serum-free and gonadotrophin-free medium supplemented with PVA or PVP without altering post-cleavage development and relative expression of some genes associated with stress and apoptosis.

Current practice patterns in tonsillectomy and perioperative care

Objectives: Tonsillectomy is one of the most commonly performed otolaryngologic procedures in the United States. Many options and controversies exist regarding techniques and peri-operative management. The purpose of the study was to examine current practice patterns among otolaryngologists regarding tonsillectomy. Methods: A 13 question survey regarding tonsillectomy techniques and peri-operative management was mailed to 10% of randomly selected board certified otolaryngologists of the AAO-HNS in the spring of 2002. Four hundred and eighteen anonymously completed questionnaires were returned, for a response rate of 58.5%. Statistical analysis of survey data was performed by means of cross tabulation and Pearson Chi-Square Calculation. Results: Monopolar electrocautery was the most common technique used among those surveyed (53.5%). There was a significant correlation between choice of monopolar electrocautery and the cited reason for choice of technique being decreased blood loss ( P<0.001). There was no relationship between pediatric fellowship training and choice of technique. 97.7% routinely admitted sleep apnea patients for post-operative observation. There was no significant correlation between practice setting (tertiary versus community) and type of post-operative monitoring for sleep apnea patients, with patients most commonly admitted to an intermediate care setting. Conclusion: In our survey, the most common surgical technique for tonsillectomy was monopolar electrocautery, chosen for the reason of decreased blood loss.

UNSTEADINESS IN EFFERVESCENT SPRAYS

The ideal spray theory of Edwards and Marx was used to investigate the dependence of effervescent spray unsteadiness on operating conditions, spatial location, and fluid physical properties. Droplet size, velocity, and arrival time at a particular spray location were measured using a Phase/Doppler Particle Analyzer. The droplet arrival times were used in calculations of interparticle arrival time gaps and interparticle time distribution functions. The spray was determined to be steady (interparticle time distribution function obeying inhomogeneous Poisson statistics) or unsteady (interparticle time distribution function not obeying inhomogeneous Poisson statistics) by comparing experimental and theoretical (steady) interparticle time distribution functions with results reported in terms of the number of deviations between the two. Since the spray was assumed to be a Poisson process, the expected deviation is the inverse of the square root of the number of interparticle events. A chi-square analysis was performed on the discrepancy. Results demonstrate that all droplet size classes, which range from diameters of 3.2 to 60.4 μm, exhibit unsteady behavior. Stokes number calculations show that the largest droplets are incapable of following the turbulent flow field motions. Gas-phase turbulence can therefore be eliminated as a cause of unsteadiness for those drops. Chi-square calculations demonstrate that the probability for obtaining such results from random fluctuations is less than 0.001. Hence, it is concluded that effervescent atomization is an inherently unsteady process. Results also indicate that spray unsteadiness is influenced by the air-to-liquid ratio by mass (ALR) and the liquid mass flow rate, depending on the properties of the liquid used in the spray, and that fluid viscosity and surface tension can affect the level of spray unsteadiness only when the spray is operating in the bubbly or intermittent slug regime. For such conditions, the spray is more unsteady when a lower-viscosity or higher-surface-tension fluid is utilized. When using a liquid that has a low viscosity (0.03 kg/m-s) and high surface tension (0.065 kg/s2), a decrease in ALR or liquid mass flow rate causes the spray to be more unsteady. The use of a high-viscosity (0.124 kg/m-s) liquid lessens the effect of operating conditions on spray unsteadiness. Finally, it was found that the spray is more unsteady at its edge, as well as at greater downstream distances.

Changes in job aspirations during physician training in Australia.

There is uncertainty regarding the effects of physician training on planned practice features of Australian physician trainees, for example plans for urban or rural, full-time or part-time and academic/research or purely clinical practice. These plans may differ between male and female trainees and between generalists and sub-specialists. To examine the changes in anticipated practice patterns over the course of advanced physician training. Longitudinal study of doctors in Australia who passed the Part I clinical examination of the Royal Australasian College of Physicians in 1991, 1992 and 1993, followed annually up until 1995. Changes in future practice plans regarding full- or part-time work, rural or urban practice and pure clinical work or a mixture with research were examined among generalist and specialist trainees and among men and women. Statistical analysis included the calculation of chi square for trend statistics and intraclass correlation coefficients. At least one follow-up questionnaire was received form 80% of the 334 original respondents. The majority had been able to obtain their training job of choice. By the time of last follow-up, around 80% planned to practise in a capital city, indicating a shift during training from those who initially stated no preference. There was also a shift towards combining research with clinical practice and among women wishing to practise part-time only. Generalists were more likely to wish to practise outside a capital city than specialists. The training programme should be revised so that careers in rural and provincial centres are encouraged and so that it is sensitive to the needs for physicians to develop research capacity. Training and career opportunities should allow all candidates (particularly women) wishing part-time employment to achieve their full career potential.

Near-infrared spectroscopic characterization of pharmaceutical powder blends

Near-infrared (near-IR) spectroscopy was used to qualitatively assess the homogeneity of a typical direct compression pharmaceutical powder blend consisting of hydrochlorothiazide, fast-flo lactose, croscarmellose sodium, and magnesium stearate. Near-IR diffuse reflectance spectra were collected from thieved powder samples using a grating-based spectrometer. A second-derivative calculation and principal component analysis were performed on the spectra prior to qualitative evaluation. Blend homogeneity was determined using single- and multiple-sample bootstrap algorithms and traditional chi-square analysis. The results suggested that bootstrap techniques provided greater sensitivity for assessing blend homogeneity than chi-square calculations and that near-IR has great potential as an analytical tool in powder blend analysis.

Ergometry as a Predictor of Basic Military Training Success

One hundred U.S. Air Force recruits were administered the cycle ergometry test to determine their aerobic fitness and timed on a 2-mile run before beginning the physical conditioning phase of training. The estimated oxygen consumption (vO2) was calculated for all trainees completing the ergometry test. The mean estimated vO2 for those successfully completing basic military training (BMT) on schedule was 27.95 +/- 1.74 ml/kg/minute, whereas the mean estimated vO2 for those not completing the program on schedule was 32.94 +/- 3.55 ml/kg/minute (not statistically different). For the 2-mile run, the times ranged from 14 minutes 17 seconds to 29 minutes 11 seconds. The mean run time for those completing BMT on schedule was 22 minutes 28.15 seconds +/- 25.79 seconds, compared to 21 minutes 19.46 seconds +/- 1 minute 26.30 seconds for those not completing the program on schedule (not statistically different). Neither relative risk nor chi-square calculations were statistically significant. No significant associations between run times or a passing cycle ergometry score at the beginning of BMT and successful completion of BMT were found.

The Contribution of Art Therapy to the Dissociative Disorders

AbstractResearch has shown that childhood trauma is a critical component in dissociative disorders (Putnam, 1989). Traumatic imagery and frightening emotions are right brain functions (Brende, 1984). In order to explore concepts of brain hemispheric lateralization and distinct right brain functioning in extensive dissociation, the Dissociative Experiences Scale (DES) scores of 114 engineering students were compared to the DES scores of 92 drawing students on a university campus. The DES measures the level of dissociative experiences. The engineering curriculum was presumed to require more analytical, left brain skills while the drawing class tasks were assumed to utilize more visual, right brain skills. The data were separated into three levels of scoring. A chi-square calculation found differences in dissociative scoring levels between the groups that approached significance at the .05 level. This suggests that brain lateralization may play a role in dissociative processes. Since art therapy may employ t...

Electrographic Seizures in Preterm and Full-Term Neonates: Clinical Correlates, Associated Brain Lesions, and Risk for Neurologic Sequelae

Electrographically confirmed seizures in preterm and term neonates were compared with respect to clinical correlates, incidence, associated brain lesions, and risk for neurologic sequelae. Over a 4-year period, 92 neonates from a neonatal intensive care unit population of 4020 admissions at a large obstetric hospital with 40,845 livebirths had electrographically confirmed seizures. Sixty-two neonates were preterm and 30 were full-term for gestational age. Chi-square calculations were used to compare the two groups. While the incidence of seizures for all neonates admitted to a neonatal intensive care unit was 2.3%, outborn neonates were more likely to have seizures than inborn neonates. Preterm neonates of < or = 30 weeks gestational age had a seizure frequency of 3.9%, which was significantly higher than that of older preterm neonates and full-term neonates. Clinical criteria contemporaneous with electrographic seizures were noted in only 28 (45%) of 62 preterm, and 16 (53%) of 30 full-term neonates. Subtle seizures coincident with electrographically confirmed seizures were the most predominant clinical type for both term and preterm neonates (71% and 68%, respectively). The distribution of clonic, myoclonic, and tonic seizures was also similar for both groups. Autonomic signs coincident with electrographically confirmed seizures (ie, blood pressure, heart rate, oxygenation, respiration changes) were more frequently observed in preterm than full-term neonates with subtle seizures; 7 (37%) of 19 compared with 1 (6%) of 16. Electrical seizures without clinical correlates were noted more frequently than electroclinical seizures for both populations.(ABSTRACT TRUNCATED AT 250 WORDS)

The Aural Perception of Nontxaditional Chords in Selected Theoretical Relationships: A Computer-Generated Experiment

The nontraditional chords in this study represent relationships defined by Allen Forte and Charles Lord. These relationships may be viewed as various degrees of similarity in pitch and interval structure between two chords. This experiment attempted to determine any correlation that may exist between theoretical and aural relatedness. The PLATO computer system presented subjects ( N = 198) a randomly ordered series of 39 experimental items. In each item, two pairs of chords were presented with one pair theoretically more similar. Listeners were asked to choose “which pair sounds more alike.” Chi-square calculations demonstrated nonsignificant differences in responses by subjects with varied backgrounds and levels of education. Confidence intervals, calculated for each item, demonstrated five significant levels of response, three of which were in accord with the theories. The results suggest that intervallic characteristics, a principal basis for the pedagogy of atonal music, are not a primary attribute in our perception of atonal music.

Gaps in Doctor-Patient Communication: Doctor-Patient Interaction Analysis

Extract: As one of several approaches to scientific analysis of doctor-patient communication 285 visits to a pediatric walk-in clinic were scrutinized using an expanded version of Bales' Interaction Process Analysis Data analysis consisted of individual case studies and computer programs for descriptive summaries of cases and index scores. Factor analysis and chi-square calculations were among the methods used to test significant relations between attributes of the doctor-patient interaction and the dependent variables, patient satisfaction, compliance, and demography. As hypothesized, a distinctive behavior pattern emerged for doctor, parent, and child. Doctors were found to talk more but show less emotion than mothers. Almost two-thirds of the mother's communication related to medical history, while the doctor discussed history and treatment but gave little reassurance or friendlines to the mother, almost half of his conversation with the child consisited of friendly statements. In general, outcome of the medical consultation was found to be favourably influenced by having physician who was friendly, expressed solidarity, took some time to discuss nonmedical, social subjects, and gave the impression of offering information freely without the patients having to request it or feeling excessively questioned. Speculation: Because of the complicated nature and limited methods available for study, the doctor-patient relation has rarely been subjected to scientific inquiry or attempts at quantification. It is hoped that the present effort as well as other ongoing studies will contribute to a body of scientific information which in itself may have application for pediatric education and practice and which ultimately might contribute one approach in urgently needed studies of the quality of medical care.

Chi-Square Significances

To the Editor.— The paper by Drs. Geller et al ( 210 :1421-1427, 1969), contains a rather gross statistical error, affecting the interpretation of the entire study. On page 1424, the authors state that chi-square test was highly significant ( P P for chi-square of 3.33 is >0.05 and for 1.875 is >0.10. The reason I checked the chisquare calculation was that instinct tells one that ten cases in each group is simply not enough to

Oriented Fossils as Paleocurrent Indicators in Paleozoic Lutites of Southern Appalachians

ABSTRACT Orientation measurements of 13,000 fossils in Paleozoic shales and fine siltstones at nine sites in the southern Appalachians demonstrate tire feasibility of using fossils as paleocurrent indicators in fine lutites. Preferred orientation was detected by vector mean and Rayleigh test procedures described by Curray (1956) and Pincus (1956), supplemented by chi-square calculations. Prior stratigraphic knowledge was used in this trial study to infer paleoslope directions so that a particular extinct fossil could be oriented relative to paleocurrents. Measurement of hundreds of individuals per sample yielded highly significant orientations which could be related to inferred paleoslope directions. Fossil groups studied include graptolites, brachiopods, criccoconarids, ostracods, gastropods, and the spore-like Tasmanites. A single section of Ordovician Athens Shale was studied in detail at Calera, Alabama, to evaluate vertical consistency of paleocurrent information from graptolites (transport direction averaged due west). On a regional pattern, this agreed with a westerly transport direction for Athens muds at Centerville and Kingsport, Tennessee. Regional consistency of a single stratigraphic horizon was demonstrated for the basal portion of the Chattanooga Shale at Clinch Mountain eastern Tennessee. Biota measured include Ambocoelia, Leiorhynchus, Styliolina, Tentaculites, and Tasmanites. These gave remarkably uniform results at four localities with an average current movement toward N75°W.

Collaborative Study of a New Alkaline Phosphatase Assay System for Milk

Abstract A new method in which phenolphthalein monophosphate is used as substrate has been developed for determining residual alkaline phosphatase: Upon hydrolysis, phenolphthalein is released and yields a red solution that is compared visually with a standard prepared from the same milk. Seven collaborators made 168 observations that were used in a statistical study of the results. Chi-square calculations and tests of independence indicated that the described method yields results on skim milk, whole milk, and light cream that are as precise and either as accurate or more accurate than those obtained with the Scharer I method. Based on these results, it is recommended that the method be adopted as official, first action.

A Double-Blind Study of Antiemetic Therapy

To Editor:— It is to be hoped human drug trials, present and future, will be viewed with a more critical eye than has been case in past. I am writing regarding A Controlled Double-Blind Study of Trimethobenzamide, Prochlorperazine and Pacebo ( 196 :796, 1966), by Dr. Philip Bardfeld. The author found no significant differences between saline and trimethobenzamide, but made a strong statistical point about the difference between prochlorperazine and placebo. I feel that any impression given by author that prochlorperazine was almost significantly better than placebo should be corrected. The author's calculation of chi-square is in error, leading as it does to a P value between 0.07 and 0.08. This error arises from a failure to make a continuity correction which is necessary in 2 × 2 chi-square tables. Rather than author's 3.25, correct chi-square value is 2.37 which corresponds to

A Collation of Chi Square Formulae

A series of formulae for chi square are presented for use with one- and two-classification tables. The formulae, written with a constant statistical notation, represent an overview of the literature in the area and are designed to provide the investigator with a series of short-cuts in the calculation of chi square. Formulae are presented and discussed within the framework of the tables to which they best apply; a worked example is provided with each major formula.

Calculation of Chi-Square to Test the No Three-Factor Interaction Hypothesis

A technique is demonstrated which is particularly well suited for modern high-speed computers. The technique involves the superimposition of Newton's method of functional interaction onto the procedure suggested by Horton. (W.D.M.)