bluuebunny/crossref_metadata_2025 huggingface dataset:
The Validity of the Lorge Thorndike Nonverbal Battery as a Predictor of the Academic Achievement of International Students
Authors: Saigh Philip A.
Published: January 2017

Twenty-seven elementary school students from 12 countries sat for the Nonverbal Battery of the Lorge Thorndike Intelligence Test during their first semester at a private American overseas school. Their final grades in English, mathematics, science, and social science, as well as their GPAs were correlated with the Nonverbal IQ. Moderate correlations were observed in each instance. Although the sample was small, these results were considered useful because of the present dearth of empirical data that may be used in forming placement decisions involving international students. It was also indicated that the teacher's daily exposure to the overseas milieu may have led to the use of more effective instructional strategies. A call for additional research in the United States and the Middle East was made.
A Comparison of Rasch Person Analysis and Robust Estimators
Authors: Smith Richard M.
Published: January 2017

Measurement disturbances, e.g., guessing, startup, plodding, etc., often result in an examinee's ability being either over- or underestimated by the maximum likelihood estimation employed in latent trait psychometric models. Several authors have suggested methods to lessen the impact of unexpected responses on the ability estimation process. This study uses simulated data to compare the standard maximum likelihood estimation with two forms of robust estimation, BIWEIGHT and AMJACK, and person analysis within the Rasch model. The results indicate that, although the two robust estimation procedures recover the generating parameters under certain conditions, in the presence of many forms of measurement disturbances they mask important information. Rasch person analysis has the advantage of not only providing a method of modifying the ability estimation procedure but also of providing a means of identifying the nature of the disturbance.
The Random Response Technique as an Indicator of Questionnaire Item Social Desirability/Personal Sensitivity
Authors: Crino Michael D. , Rubenfeld Stephen A. , Willoughby Frederick W.
Published: January 2017

Begin, Boivin, and Bellerose (1979) presented an hypothesis relating the random response technique to the sensitivity of questionnaire items. This hypothesis states that if one assumes the random response technique assures subjects a greater degree of anonymity than the traditional direct questionnaire method, then a comparison between these two methods would be a direct and useful index of the social disirability of a particular trait, behavior, or attitude. It is proposed that if the proportion of “yes” responses to a particular item was higher for the direct questionnaire group than the random response group, then the item was socially desirable. If the converse resulted, the item was socially undesirable. The Marlow-Crowne Social Desirability Scale (Crowne and Marlowe, 1960; Crowne and Marlowe, 1964) was used to test this hypothesis. The results suggest a potential new use for the random response technique. The implications of this procedure for scale construction are also discussed.
Constructing Short Forms from Composite Tests: Reliability and Validity
Authors: Willson Victor L. , Reynolds Cecil R.
Published: January 2017

Short forms of individual assessment instruments are often used as screening devices which are economical of time and money. Their construction is usually based on empirical maximization of reliability through item selection, but construction is possible utilizing technical manual normative data. Reliability equations are presented here based .on classical true score theory. Validity estimation equations are presented which are especially useful when short forms of revised instruments are created. They can utilize information from the old form validities.
Student Perceptions as Predictors of Academic Performance in College Developmental Studies
Authors: Hogrebe Mark C. , Dwinell Patricia L. , Ervin Leroy
Published: January 2017

The investigation examined (a) perceptions held by students of their preparation to do college-level work, (b) attitudes towards the Developmental Studies program and the university, and (c) knowledge of Developmental Studies as predictors of academic performance. In addition, the high school grade point average (GPA) and the College Board Scholastic Aptitude Test scores were employed as predictors in order to provide a standard by which to compare the predictive efficiency of the student-perception variables. The academic variables, in comparison with those associated with student perceptions, accounted for more variance in first-quarter GPA. Of the student-perception variables, those related to a student's estimation of preparation for college-level courses appeared to have the most direct relationships to first-quarter GPA.
The Factorial Validity of the Study Attitudes and Methods Scale (SAMS)
Authors: Michael William B. , Denny Barbara , Ireland-Galman Michelle , Michael Joan J.
Published: January 2017

For a sample of 181 community college students, five subtests each of five items were assembled for each of the six 25-item scales of the Study Attitudes and Methods Survey (SAMS): Academic Interest—Love of Learning, Academic Drive—Conformity, Study Methods, Study Anxiety, Manipulation, and Alienation Toward Authority. A principal factors solution of the intercorrelations of the 30 assembled subtests resulted in five interpretable factors identified as Facilitative Study Behaviors (portraying a fusion of the first three factor scales into a general dimension), Study Anxiety, Manipulation, Alienation Toward Authority, and Academic Interest—Love of Learning (the subtests of this last factor not only defining a separate dimension but also sharing modest variance with the general trait indicative of a positive orientation to study effort). It is anticipated that the use of data from the extensive item analyses and factor analytic outcomes can lead to the development of shorter scales demonstrating a higher degree of discriminant validity.
The Concurrent Validity of the Peabody Picture Vocabulary Test-Revised Relative to the Comprehensive Tests of Basic Skills
Authors: Beck Frances W. , Black Frederick Lee , Doles Jeanette
Published: January 2017

In this investigation the relationship was explored between the Peabody Picture Vocabulary Test-Revised (PPVT-R) and the Comprehensive Tests of Basic Skills (CTBS). The sample consisted of 61 randomly selected elementary school students. The PPVT-R was correlated positively and significantly with all CTBS tests with the exception of Mathematics Computations. Obtained correlations ranged from .09 to .57. Highest correlations fell within the moderate range (.40 to .60). The levels of obtained correlations were sufficient to recommend the use of the PPVT-R as a screening instrument for identification of pupils with academic problems.
An Analysis of the Competitive Dimensions of Indian Cotton Textile Industry
Authors: Singh Narendra , S. Kundu Surinder
Published: January 2017

Globalization has opened vast market opportunities for Indian cotton textile industry; but at the same time the industry is exposed to the threats of fierce competition. Survival and growth in such an environment require achieving global competitiveness. This paper endeavours to identify the nations posing challenge to it in post-MFA regime, besides, it also explores and analyzes the intra sector competitiveness of the industry. The study is based on empirical investigation of senior and middle level executives from 81 cotton textiles manufacturing and exporting firms in India. The analysis brings out that China, Vietnam, Bangladesh and Malaysia are emerging as major competitors in international textile market. Furthermore, the industry is found to be competitive in terms of input factors - labour, transportation and raw material; but not in terms of finance, power and technology.
Dynamic Competitive Position between the Foreign Joint Venture and NICs’ Indigenous Firms
Authors: Kwon Yung Chul , Ryans John K.
Published: January 2017

Three years ago, South Korea exported hardly any cars. In 1987, it will probably send more than 450,000 cars abroad; most will go to the United States. It is a prospect that thrills the South Koreans, worries protectionist Americans, and frightens the Japanese carmakers, whose dominance of the small-car market the South Koreans are challenging.

("South Korea's Carmakers Count Their Blessings," The Economist, 3 January 1987, p. 45)
A Test of the Reciprocal-Effects Model of Academic Achievement and Academic Self-Concept in Regular Classes and Special Classes for the Gifted
Authors: Preckel Franzis , Schmidt Isabelle , Stumpf Eva , Motschenbacher Monika , Vogl Katharina , Schneider Wolfgang
Published: January 2017

According to the reciprocal-effects model (REM), prior academic self-concept (ASC) has a positive effect on subsequent achievement beyond what can be explained in terms of prior achievement and vice versa. The present study investigated the REM for students studying in special classes for the gifted compared to students studying in regular classes. The sample included 283 students from 14 special classes for the gifted and 639 students from 26 regular classes from seven high-track schools of the German secondary school system (“Gymnasium”). Students’ math achievement (grades and standardized achievement tests) and their ASC in math were assessed four times from the beginning of Grade 5 to the middle of Grade 7. Reciprocal relationships between ASC and academic achievement were positive and comparable across class types, confirming the validity of the REM.
Evaluation of a Psychomotor Vigilance Task for Touch Screen Devices
Authors: Arsintescu Lucia , Mulligan Jeffrey B. , Flynn-Evans Erin E.
Published: January 2017

Objective:

Our goals were to compare three techniques for performing a psychomotor vigilance task (PVT) on a touch screen device (fifth-generation iPod) and to determine the device latency.

Background:

The PVT is a reaction-time test that is sensitive to sleep loss and circadian misalignment. Several PVT tests have been developed for touch screen devices, but unlike the standard PVT developed for laboratory use, these tests allow for touch responses to be recorded at any location on the device, with contact from any finger. In addition, touch screen devices exhibit latency in processing time between the touch response and the time registered by the device.

Method:

Thirteen participants completed a 5-min PVT on a touch screen device held in three positions (on a table with index finger, handheld portrait with index finger, handheld landscape with thumb). We compared reaction-time outcomes in each orientation condition using paired t tests. We recorded the first session using a high-speed video camera to determine the latency between the touch response and the documented response time.

Results:

The participants had significantly faster reaction times in the landscape-oriented position using the thumb, compared with the portrait-oriented position using the index ( M = 224.13 and M = 244.26, p = .045). Using data from 1,241 unique touch events, we found a mean device latency of 68.53 ms that varied highly between individuals.

Conclusion:

Device orientation and device latency should be considered when using a touch screen version of a PVT.

Application:

Our findings apply to researchers administering touch screen versions of the PVT.
Performance Effects of Long Term Random Vertical Vibration
Authors: Holland Clarence L.
Published: January 2017

Compensatory tracking performance was assessed during six hours of continuous exposure to random vertical vibration conditions. The results indicate that performance is significantly affected by the location of peak vibration acceleration power. Longitudinal assessment of tracking performance revealed that subjects can track and perform other tasks without serious decrement for as long as six hours while experiencing vibration acceleration intensities of 0.16g RMS.
Tracking Performance with Advanced and Delayed Visual Displays
Authors: Gifford Robert N. , Lyman John
Published: January 2017

Human operator performance in continuous pursuit tracking when the stimulus either disappeared prior to the appropriate response time or appeared subsequently to that time was investigated. Tracking was one-dimensional, the stimulus appeared to vary randomly, and feedback of results wasn't provided. The stimulus, consisting of the sum of three low-frequency sine waves, appeared on recording paper tape, moving at 1.0 cm/sec. Masks hid the display in steps up to 1.0 secs, before or 0.5 secs. after the position of a manually-controlled pointer. Timing performance was measured by the peaks of cross-correlations of stimulus/response data pairs which had been successively shifted in time. Tracking performance was measured by RMS error. Timing was increasingly too early for advanced displays but followed closely the actual appearance time of delayed displays. RMS tracking error increased with increasingly advanced and delayed displays. Practice effects were negligible.
The Effects of Differential Value on the Recall of Realistic Targets
Authors: Christ Richard E. , Teichner Warren H.
Published: January 2017

The effects of differential value upon detection and recall were investigated using a multisymbol visual display. Three groups of 14 subjects each viewed slides containing experimentally varied numbers of different realistic targets drawn from a population of nine possible targets. All subjects were instructed to maximize the value of their reports. One group was told that all targets were of equal value; for another group a different value was assigned to each of the nine targets; and for a third group, three different values were assigned to three sets of three targets each. The results suggested that performance may depend less on the differences in values assigned to targets than on the number and range of different values.
The Effects of Ambient Noise upon Signal Detection
Authors: Mirabella Angelo , Goldstein Donald A.
Published: January 2017

One aspect of the sensory interaction phenomenon was reviewed, the effect of ambient noise upon signal detection performance. An objective of this review was to arrive at possible generalizations about the effects of noise through an examination of variables affecting both similarities and divergencies of results. A second objective was to discuss some of the limitations of noise research for theory and practice, using sonar surveillance in undersea warfare as a reference operation. The conclusions from the review were organized under two major headings:(I) effects of noise for the alerted operator case involving threshold sensitivity, and (2) effects of noise for the unalerted operator case involving vigilance behavior. The limitations of the literature for theory and practice were also discussed under these major headings.
Man-Computer Communication Techniques: Two Experiments
Authors: Root Robert T. , Sadacca Robert
Published: January 2017

Two experimental studies are reported that were intended to evaluate alternative man-computer communication techniques within the context of a computer-based image interpretation facility. The first experiment, comparing five different data entry procedures, indicated that, although a procedure requiring the interpreter to enter report data directly using a teletype keyboard resulted in the shortest overall throughput time, a procedure involving message composition by the image interpreter with subsequent transcription by a communicator minimizes the time spent by the interpreter in report generation and maximizes the time available for the detection and identification of targets on aerial imagery. The second experiment evaluating alternative word form-data entry format combinations, showed no differences among the six combinations studied.
Estimation of Values of Energy Expenditure Rate from Observed Values of Heart Rate
Authors: Andrews Robert B.
Published: January 2017

Different bases upon which linear regression equations can be constructed for estimating values of energy expenditure rate from observed values of heart rate are examined. Approximately 100 different regression equations corresponding to different bases were developed from 510 observations made of 11 different tasks. The regression equations constructed on the various bases are compared with one another and with respiratory calorimetry in terms of the experimental error which each introduces into the estimation of energy expenditure. The results suggest that for certain kinds of investigations the regression method can be substituted fruitfully for respiratory calorimetry.
Coupling Effects and Performance in Viligance Tasks
Authors: Hatfield Jimmy L. , Soderquist David R.
Published: January 2017

The performance of 32 subjects on 90-min. auditory and visual vigilance tasks were measured in conventional and theory of signal detection indices as a function of “coupling,” sense mode, and time on task. Order effects, correlations between sense modes, and possible effects of observing responses were also examined. Regardless of the coupling condition or sense mode involved, β increased while hits and false alarms decreased as time on task increased. There was no significant decline in d' over time on task for either sense mode or coupling conditions. In general, conventional measures of performance were similar for the auditory and visual tasks. Significant cross-modality correlations were obtained for false alarms, latency, and β values. No order effects were observed. The results are discussed in terms of expectancy theory and an observing response model.
Multimedia Strategies for Improving the Effectiveness of Managerial Staff Meetings
Authors: Griver Jeanette A. , Robinson Margot B.
Published: January 2017

The application of a communication training program designed to reduce nonproductive time and to increase the level of individual participation during managerial staff meetings is described. The program was applied to a group of 20 staff members of a 152-bed hospital and was evaluated over a two-year period. After a preliminary communication anlaysis, multimedia feedback techniques were employed to reduce individual communication errors. Performance analyses, audio- and video-tape recordings and playback were techniques employed. Results showing a 46% average time decrease in staff meetings and a 100% increase in individual participation during meetings are being maintained in the third year of study.
Two Explanations of Temporal Changes in Ability-Skill Relationships: A Literature Review and Theoretical Analysis
Authors: Alvares Kenneth M. , Hulin Charles L.
Published: January 2017

Two models which explain both temporal changes in behavior during training and temporal decreases in correlations between ability measures and performance measures are presented. It is argued that both phenomena are dependent on the same process and that each of the models presented adequately accounts for the experimental data. The changing task model originally proposed by Woodrow and later elaborated by Fleishman assumes that the abilities which contribute to task performance change systematically over time. A second model, the changing subject model, assumes that practice on the criterion task systematically and significantly affects the ability levels of the subjects. A discussion of the changed conception of the ability-skill distribution necessitated by the second model is presented. The psychological and organizational implications of the two models are discussed, and the well nigh impossibility of an empirical evaluation is pointed out.
Body Orientation Under Vertical Sinusoidal Vibration
Authors: Johnston Waymon L. , Ayoub M. M.
Published: January 2017

Human performance during a low-frequency vibratory environment was investigated. The performance measures of interest were the accuracy and total time of a whole-body orientation task. A zero vibration condition as well as frequencies of 2, 5, and 8 Hz. were studied. Amplitude was held constant at 0.09 in., resulting in acceleration intensities from 0.04 to 0.58 g. Performance was studied before, during, and after exposure to the vibration environment. Twenty male subjects participated in the investigation in both sitting and standing body positions. Vibration exposure times were 20 min. for all sessions. The task used in this investigation was a body orientation task that required subjects to orient their bodies as quickly and as accurately as possible toward one of a series of colored lights located at angles of 15, 30, and 60° on either side of a zero reference plane. The results indicated that the shortest travel time was obtained under zero vibration conditions but that most accurate performance was obtained under vibrations of 2 Hz. Differences in performance were also found between the two body positions and direction of orientation.
The Measurement of Orthostatic Tolerance
Authors: Shvartz Esar
Published: January 2017

The problem of orthostatic tolerance is discussed with respect to the factors affecting it, methods of assessment, and the analysis of orthostatic data. Orthostatic heart rate and blood pressure and responses of fainters and nonfainters measured by different methods are illustrated. It is shown that different tilt tables result in similar orthostatic responses, that results obtained in standing are not necessarily related to tilt-table responses, that qualitative and quantitative orthostatic responses are closely related, and that reclining heart rate alone can indicate tilt tolerance.
Comparative dynamics of public health spending: Re-conceptualizing delta-convergence to examine OECD and Latin America
Authors: Noy Shiri , Sprague-Jones Jessica
Published: January 2017

Theoretical interest in the effects of globalization and regionalization on national outcomes, coupled with the unprecedented availability of comparable, cross-national data, creates an expanded opportunity for social scientists to test propositions of convergence over time. In this article, we investigate trends and convergence in public health spending in Latin America and the Caribbean (LAC) compared with Organisation for Economic Co-operation and Development (OECD) countries. Public health expenditures represent an important indicator of social protections, especially for the most vulnerable and the poor. In order to assess patterns in public health convergence in the region, we introduce an innovative conceptualization of delta-convergence. While this term has referred to countries’ convergence toward an exemplar or an abstract ideal, we retool delta-convergence to examine how countries move toward or away from a regional mean, which is itself allowed to vary over time. We find an upwards trend in public health spending as a percentage of gross domestic product (GDP) in both Latin America and the OECD, and while in OECD there is little evidence of convergence or divergence, our results indicate a period of convergence followed by divergence in Latin America. Our analysis further reveals important regional dynamics at play, and engages with world polity and world systems theory and the literatures on regionalization versus globalization. We conclude by discussing the utility of using delta-convergence analysis to identify group trends, outliers, and country-specific trajectories.
Predicting performance of electrical engineering students using cognitive and non-cognitive features for identification of potential dropouts
Authors: Sultana Sara , Khan Sharifullah , Abbas Muhammad A
Published: January 2017

The student dropout rate in universities is fascinating, especially among the students of Electrical Engineering. Even the most developed European countries face 40% to 50% dropout rate of engineering students during their first year, and the rate can be as high as 80% for some engineering disciplines. This problem calls attention of educators and university administration to take measures which can help in the reduction of the dropout rate and assist students in successfully completing their degree. Among many other solutions to control the student dropout rate, one is the adoption of a prediction mechanism whereby students can be warned about their potentially poor performance so that they can improve their performance resulting in better grades. Most of the existing prediction mechanisms apply various machine learning techniques on student cognitive features. In addition, non-cognitive features also have significant impact on students’ performance; however, they have been sparsely applied for prediction. This research aims at improving the existing prediction mechanism by exploiting both cognitive and non-cognitive features of students for predicting their results. It has been found in the result analysis that addition of cognitive features increases prediction accuracies of decision tree; however, the addition does not play a significant role in other techniques. The study also identified the individual cognitive features that should be considered by students and universities to cater for drop outs.
Nonisothermal Melting and Crystallization of Foamed Crosslinked Polyethylene
Authors: Kotzev G. , Touleshkov N. , Christova D. , Nedkov E.
Published: January 2017

Foamed crosslinked specimens of low density polyethylene are produced by hot mould injection moulding. Dicumylperoxide, as crosslinking agent and azodicarbonamide as blowing agent, were used. The three components are blended and granulated in advance in an extruder-granulator at temperatures of 100-125°C. The contents of blowing and crosslinking agents in the composites studied are 5-15 and 0.08-0.6, respectively, in percents by weight. The ability for maximum foaming was studied by determining the overall density of the specimens. The crosslinking degree was calculated from the equilibrium strain value defined at temperature 140°C and pressure stress 0.045 MPa. The same parameter was estimated also by the melt flow index. The LDPE morphological parameters were determined on the basis of DSC-graphics obtained by a Perkin-Elmer DSC-7 differential scanning calorimeter at heating and cooling rates of 10°C/min. The activation energy for transport through phase boundary crystal melt, the surface energy of the crystal, the long period and the degree of the crystallinity were calculated by computer programs using formulae of non-isothermal melting and crystallization kinetics theory.

It is found that the overall density of the specimens increases with the increase of the crosslinking agent concentration in the range of 0.08-0.6% by wt. At low concentrations of dicumylperoxide, the increase of the blowing agent concentration results in a decrease of the density, while at high crosslinking agent concentration the opposite trend is observed. The crosslinking degree of the foamed polyethylene increases with the increase of the concentrations of dicumylperoxide and azodicarbonamide, and the flowability of the foamed polyethylene melt decreases correspondingly. The crosslinking of the foamed LDPE affects the non-isothermal phase transitions. With the increase of the crosslinking degree, the phase transition temperatures and the degree of crystallinity decrease. The values obtained for the energies of activation for transport through the phase boundary, the surface energy of the crystal and the long period are comparable with the values obtained by other authors.
Experimental Determination of the Vapor Phase Thermal Conductivity of Blowing Agents for Polyurethane Rigid Foam
Authors: Heinemann T. , Klaen W. , Yourd R. , Dohrn R.
Published: January 2017

Blowing agents are mainly responsible for the insulation properties of polyurethane rigid foams. Detailed knowledge about the vapor conductivity of blowing agents and their mixtures is essential for their basic understanding. In addition to their insulation properties, blowing agents to a large extent determine the mechanical properties of the foam. Today, blowing agent mixtures are often used in an attempt to combine both worlds, low thermal conductivity and high vapor pressure at low temperatures. Our investigations aim at a better understanding of the relevant practical properties of blowing agents and their mixtures and to focus on their meaning for actual and potential foam systems of interest to the rigid foam insulation market.

A newly developed transient hot wire method was used to determine the vapor phase thermal conductivity of various blowing agents used in rigid polyurethane foam. Data for CFC-11, HCFC-141b, HFC-365mfc, HFC-356mffm, HFC-245fa, HFC-245ca, cyclopentane, isopentane, n-pentane, isobutane, n-butane, and carbon dioxide have been generated. In addition to measurements of the pure compounds, current market mixtures of cyclopentane with low boiling hydrocarbons have been investigated. Experiments have been performed at pressures between 0.2 MPa and 1.5 MPa and temperatures between 298 K and 421 K.
Comparison of Technology and New Developments with Hydrocarbon Blown Rigid Foams Shows a Clear Tendency to Cyclopentane/Hydrocarbon Blends
Authors: Altoe P. , Dean G. H. , Parenti V. , Clavel P.
Published: January 2017

Rigid foams blown with hydrocarbons have shown a great progress since this technology was implemented in 1992 in Europe, and culminated, last year, in the introduction of blends of hydrocarbons and more particularly cyclopentane/isobutane. Also recently, other blends have found favor where the more complicated handling of butane may present some difficulties.

In the hydrocarbon family, cyclopentane is the best option in terms of gas k-factor, but its high boiling point requires higher density and shot weights in cabinets to guarantee long term dimensional stability. The best cost option is provided by the iso-/n-pentane blend. However, the foams produced show inferior k-factor, although final energy consumption is not affected to the same degree.

In general, the addition of another co-blowing hydrocarbon such as isobutane, isopentane or c-pentane negatively affects the insulation performance of the foam, but recent polyurethane system developments have allowed the retention of the same k-factor values as those of pure cyclopentane blown foams.

This paper aims to compare the different hydrocarbon blowing agent alternatives introduced during the past period and includes theoretical cell gas modeling, creep performance and compressive strength ageing tests. These methods have been used to evaluate and predict, during the foam development phase, the short and long term dimensional stability of the foam. An attempt will be made to understand if the combination of all of them is necessary for getting reliable information.

Results from cabinets foamed with these cyclopentane based hydrocarbon blends have confirmed the initial findings and are discussed.

It is a further objective of this paper to give the OEMs the data that they require to select the optimum technology to answer their needs in terms of cost, processing performance and insulation value.
On the Linear Elastic Properties of Regular and Random Open-Cell Foam Models
Authors: Van Der Burg M. W. D. , Shulmeister V. , Van Der Geissen E. , Marissen R.
Published: January 2017

Foams can be created from coagulation of gas bubbles in liquid. After removal of cell faces, an open-cell foam remains consisting of a strut framework. In the past, mechanical properties were estimated by a small unit cell consisting of only a few struts. However, the random geometry of the foam can be of importance for the linear elastic properties. Here, large foam unit cells are created using Voronoi techniques. A smooth transition from regular to random geometries is made, showing the strong sensitivity of the mechanical properties from the geometry of the microstructure. Uniaxial global loads are transmitted through chains of highly loaded struts. The deformation of the struts in the foam is a mixture of bending and normal deformation, the ratio of which shown here to be dependent on the magnitude of the density.
GelMA-Encapsulated hDPSCs and HUVECs for Dental Pulp Regeneration
Authors: Khayat A. , Monteiro N. , Smith E.E. , Pagni S. , Zhang W. , Khademhosseini A. , Yelick P.C.
Published: January 2017

Pulpal revascularization is commonly used in the dental clinic to obtain apical closure of immature permanent teeth with thin dentinal walls. Although sometimes successful, stimulating bleeding from the periapical area of the tooth can be challenging and in turn may deleteriously affect tooth root maturation. Our objective here was to define reliable methods to regenerate pulp-like tissues in tooth root segments (RSs). G1 RSs were injected with human dental pulp stem cells (hDPSCs) and human umbilical vein endothelial cells (HUVECs) encapsulated in 5% gelatin methacrylate (GelMA) hydrogel. G2 RSs injected with acellular GelMA alone, and G3 empty RSs were used as controls. White mineral trioxide aggregate was used to seal one end of the tooth root segment, while the other was left open. Samples were cultured in vitro in osteogenic media (OM) for 13 d and then implanted subcutaneously in nude rats for 4 and 8 wk. At least 5 sample replicates were used for each experimental group. Analyses of harvested samples found that robust pulp-like tissues formed in G1, GelMA encapsulated hDPSC/HUVEC-filled RSs, and less cellularized host cell–derived pulp-like tissue was observed in the G2 acellular GelMA and G3 empty RS groups. Of importance, only the G1, hDPSC/HUVEC-encapsulated GelMA constructs formed pulp cells that attached to the inner dentin surface of the RS and infiltrated into the dentin tubules. Immunofluorescent (IF) histochemical analysis showed that GelMA supported hDPSC/HUVEC cell attachment and proliferation and also provided attachment for infiltrating host cells. Human cell-seeded GelMA hydrogels promoted the establishment of well-organized neovasculature formation. In contrast, acellular GelMA and empty RS constructs supported the formation of less organized host-derived vasculature formation. Together, these results identify GelMA hydrogel combined with hDPSC/HUVECs as a promising new clinically relevant pulpal revascularization treatment to regenerate human dental pulp tissues.
Dental Prophylaxis and Osteoradionecrosis: A Population-Based Study
Authors: Chang C.T. , Liu S.P. , Muo C.H. , Tsai C.H. , Huang Y.F.
Published: January 2017

The aim of this study was to investigate the association of different dental prophylactic modalities and osteoradionecrosis (ORN) and determine the risk of ORN under different timing periods of scaling, with the use chlorhexidine mouth rinse after surgery and with different strategies of fluoride gel application in head and neck cancer (HNC) participants. A cohort of 18,231 HNC participants, including 941 ORN patients and 17,290 matched control cases, were enrolled from a Longitudinal Health Insurance Database for Catastrophic Illness Patients (LHID-CIP) in Taiwan. Based on different dental prophylactic modalities before radiotherapy, including chlorhexidine mouth rinse, scaling, and fluoride gel, all HNC subjects were stratified into different groups. The Cox proportional hazard regression was used to compare ORN incidences under different dental prophylactic modalities. The results revealed that scaling and chlorhexidine mouth rinse were significantly related to ORN risk ( P = 0.004 and P < 0.0001). Chlorhexidine mouth rinse was highly correlated to ORN occurrence (hazard ratio [HR], 1.83–2.66), as exposure increased the risk by 2.43-fold among oral cancer patients, regardless of whether they had received major oral surgery or not. Oral cancer patients receiving scaling within 2 wk before radiotherapy increased their incidence of ORN by 1.28-fold compared with patients who had not undergone scaling within 6 mo. There is no significance of fluoride application for dental prophylaxis in increasing ORN occurrence. In conclusion, dental prophylaxis before radiotherapy is strongly correlated to ORN in HNC patients. Chlorhexidine exposure and dental scaling within 2 wk before radiotherapy is significantly related to ORN risk, especially in oral cancer patients. The use of 1.1% NaF topical application did not significantly increase the risk of ORN in HNC patients. An optimal dental prophylaxis protocol to reduce ORN should concern cancer location, cautious prescription of chlorhexidine mouth rinse, and proper timing of scaling.
Survival Predictions of Ceramic Crowns Using Statistical Fracture Mechanics
Authors: Nasrin S. , Katsube N. , Seghi R.R. , Rokhlin S.I.
Published: January 2017

This work establishes a survival probability methodology for interface-initiated fatigue failures of monolithic ceramic crowns under simulated masticatory loading. A complete 3-dimensional (3D) finite element analysis model of a minimally reduced molar crown was developed using commercially available hardware and software. Estimates of material surface flaw distributions and fatigue parameters for 3 reinforced glass-ceramics (fluormica [FM], leucite [LR], and lithium disilicate [LD]) and a dense sintered yttrium-stabilized zirconia (YZ) were obtained from the literature and incorporated into the model. Utilizing the proposed fracture mechanics–based model, crown survival probability as a function of loading cycles was obtained from simulations performed on the 4 ceramic materials utilizing identical crown geometries and loading conditions. The weaker ceramic materials (FM and LR) resulted in lower survival rates than the more recently developed higher-strength ceramic materials (LD and YZ). The simulated 10-y survival rate of crowns fabricated from YZ was only slightly better than those fabricated from LD. In addition, 2 of the model crown systems (FM and LD) were expanded to determine regional-dependent failure probabilities. This analysis predicted that the LD-based crowns were more likely to fail from fractures initiating from margin areas, whereas the FM-based crowns showed a slightly higher probability of failure from fractures initiating from the occlusal table below the contact areas. These 2 predicted fracture initiation locations have some agreement with reported fractographic analyses of failed crowns. In this model, we considered the maximum tensile stress tangential to the interfacial surface, as opposed to the more universally reported maximum principal stress, because it more directly impacts crack propagation. While the accuracy of these predictions needs to be experimentally verified, the model can provide a fundamental understanding of the importance that pre-existing flaws at the intaglio surface have on fatigue failures.
The Identification and Treatment of Opiate Users in Police Custody
Authors: Pearson Richard , Robertson Graham , Gibb Robert
Published: January 2017

All detainees admitted to seven London police stations were observed over a six-month period (n=2,947). Four per cent were identified as opiate users, although the actual percentage is likely to be much higher. Compared to the general population of detainees there were significantly more women among known opiate users and this group also contained a higher percentage of white detainees and people born in the British Isles. People born in continental European countries were also over-represented. A little more than half of known users did not reveal their use on arrival at the police station. At least 60% of known opiate users remained well throughout their detention, 30% were intoxicated through drugs at the time of their arrest, but only 13% displayed signs or symptoms of withdrawal during their detention. Overall, 65% of the known opiate users were seen by a police surgeon and of these 52% were given medication. All of those withdrawing were given drug treatment, but most of those who were intoxicated by opiates, or who remained well throughout their detention, received no medication. Of those given medication 86% received an opiate, dihydrocodeine being the commonest preparation, usually in association with a benzodiazepine. Despite the adoption of differing management paradigms among police surgeons, the actual medical treatment of opiate-using detainees was pragmatic and determined by individual need.
Section 5(2) of the Mental Health Act 1983 in Practice: An Audit and a Review
Authors: Ebrahim Irshaad , Botha Claude
Published: January 2017

All applications of s.5(2) of the Mental Health Act 1983 (MHA) between January 1997 and December 1998 were examined to assess variables likely to affect outcome and to compare these findings to other similar published studies. Of the 154 applications (7% of all admissions), 56 were converted to s.3 and 39 to s.2 of the MHA. We found that the time of application, grade of doctor making the application and the day of application were the best predictors of outcome of s.5(2). Apart from a few exceptions, our findings were generally in keeping with previous published results. These findings suggest a national trend in the clinical use of s.5(2) and may provide a useful guide for those considering reform of this part of the MHA.
What Happens to Special Hospital Patients Admitted to Medium Security?
Authors: Quinn Patrick , Ward Mark
Published: January 2017

This article describes the outcome of all the Special Hospital patients admitted to and discharged from the Norvic Clinic over a period of ten years since its opening in 1984. This study identified 23 patients. Of those transferred, 56% had a legal classification of mental illness.

A much higher percentage (91%) were restricted under the powers of s.41 of the Mental Health Act 1983, compared to 69% in the West Midlands study (Cope and Ward, 1993). There appears to be a significant difference between the mental disorder groups for age on admission to Special Hospital when considering all patients (males and females). This difference is not maintained when males and females are looked at separately, although the result for males is nearly significant (p=0.0606). The number of female patients is small (five) and so the tests will hardly be reliable for the female sample. No significant differences were demonstrated for any of the other variables considered.

Like the West Midlands study, minor reconvictions were completely absent. This was an unusual finding within the West Midlands study and not replicated from any of the previous Special Hospital studies. In this study, failure constituted an unsuccessful transfer with return to Special Hospital and reconviction. The percentage of those returned to Special Hospital without reaching the community was slightly lower than the West Midlands study, for both the mentally ill and those classified as suffering from psychopathic disorder.
Full-Fat Cream
Authors: Goodman Jonathan
Published: January 2017

The thing inside the little Jiffy envelope, airmailed from New York, was cryptic: a slim, square-shaped bit of black plastic (which I, though I had never seen one before, assumed was a computer disk) with a label saying simply ‘CREAMANIA’ (which, not that I am good at guesswork but because I am a crime historian, I assumed meant that the disk had something to do with Thomas Neill Cream, the boss-eyed American doctor who, having come to London in the early 1890s, fatally poisoned a bevy of local prostitutes - two of whom, Matilda Clover and Emma Shrivell, come high on the roster of victims with fictive-sounding names). Wait a moment: I tell a lie - there was another word on the label: ‘complimentary’ (which didn't please me but at least prevented anger arising from the assumption that I would soon be getting an invoice for this thing that I hadn't ordered).
The Sexual Profile of Rapists in Singapore
Authors: Gwee K P , Lim L E C , Woo M
Published: January 2017

To our knowledge, this is the first paper that examines the sexual profile of rapists in Singapore.

A semi-structured interview based on a questionnaire about sexual habits was conducted on 62 convicted rapists and a control group of 63 prisoners comprising 32 convicted for violent non-sexual offences and 31 for non-violent non-sexual offences.

Significantly more rapists masturbated at least once a month and were exposed to pornography within six months before the offence when compared to non-violent controls. Violent controls did not differ significantly from rapists in any aspect of the sexual history. The greater similarity between rapists and violent controls lends support to the concept of rape as a violent rather than sexual offence.

A subgroup of 17 ‘hypersexual’ rapists were identified who were either having sex or masturbating very frequently but had still resorted to rape. Compared to the other 46 rapists, the ‘hypersexual’ rapists were more likely to have fantasised predominantly about rape or bondage and to cite domination, aggression or hostility as reasons for committing rape, suggesting an even stronger element of power and aggression than in their less sexually active counterparts.
Medico-Legal Reports and Gatekeeping: One Year of Referrals to a Forensic Service
Authors: Gethins E , Larkin E , Davies S , Milton J
Published: January 2017

Forensic psychiatrists and the services they provide have been subject to recent scrutiny and high public profile. This study examined part of the work of a regional and district forensic service by looking at a one-year cohort of referrals, and the factors contributing to patient admission, including requests for medico-legal reports. The sample consisted of all referrals to the East Midlands Centre for Forensic Mental Health, Leicester from 1 January 1998 to 31 December 1998. Information on referrals was collected retrospectively using a proforma to collate data from referral letters and the reports prepared by assessing clinicians.

Two hundred and eighty referrals relating to 260 individuals were received. The sample characteristics were broadly similar to those reported in previous studies. The finding that 70% of those assessed were referred for medico-legal reports by courts or solicitors, and the fact that only 20% of this group finally entered the forensic service, led us to consider whether this work was legitimate use of National Health Service time. We examined this group more closely, and found that referral for a medico-legal report could be considered as a screening test for entry into the forensic services and there are good arguments for this work continuing.
Temperature Methods of Estimating the Time of Death
Authors: Marshall Thomas K.
Published: January 2017

Summary

Methods of estimating the time of death from the body temperature are reviewed and an assessment made of the inaccuracy of those based on a formula containing a single exponential term.
Fatal Acute Poisoning by Intradermal Absorption of Phenol
Authors: Griffiths G. J.
Published: January 2017

The history, post-mortem findings, and the qualitative chemical screening at autopsy are described in a case of acute intradermal phenol poisoning. The forensic estimate of phenol in the blood is described. A discussion of the immediate and later treatment of such a case is given.

Reading through the literature on acute phenol poisoning, little has been written on the subject of intradermal absorption of phenol. Standard forensic reference books (Camps, 1968; Simpson, 1966) have drawn attention to this mode of poisoning with reference to past and present literature. Recently a paper on the toxicity of phenol absorption in animals and an effective first-aid measure in treatment have been published (British Chemical Industries Safety Council of Chemical Industries Association, 1970; Conning and Hayes, 1970).