bluuebunny/crossref_metadata_2025 huggingface dataset:
Lowering Communication Barriers in Operating Room Technology
Authors: Webster Jessica L. , Cao Caroline G. L.
Published: December 2006

Objectives: This paper examines the effects of new technology on team communication and information flow in a complex work environment, and offers design suggestions for improved team performance. Background: Case study of a robot-assisted cholecystectomy procedure revealed teamwork disruption and an increase in the complexity of information flow and communication in the operating room as a result of the novel technology. A controlled experiment using a between-subjects design was conducted to test the hypothesis that providing critical information in a timely and accessible manner would increase communication efficiency and reduce errors in task performance. Methods: Eighteen pairs of participants took part in a simulated tool-changing task in surgery under one of three communication conditions: (a) no rules, (b) scripted, or (c) automated. Results: Teams in the scripted and automated conditions performed significantly faster than the no-rules teams ( p < .05). Teams in the automated condition made significantly more errors than those in the scripted condition ( p < .05). Conclusion: Scripted speech can facilitate team communication and adaptation to new technology; automatic information display interfaces are not useful if the modality is incompatible with operator expectations. Application: Information displays and communication protocols can be designed to ease adaptation to complex operating room technology.
Change in Dynamic Visual Acuity (DVA) by Pupil Dilation
Authors: Ueda Tetsuo , Nawa Yoshiaki , Yukawa Eiichi , Taketani Futoshi , Hara Yoshiaki
Published: December 2006

Objective: This study was conducted to assess dynamic visual acuity (DVA) under pupil dilation. Background: Pupil dilation may negatively affect driving performance. Methods: Thirty healthy young adults (mean age 29.4 years) with pupil dilation participated in this study as the Mydrin P group. In addition to them, 15 healthy young adults (mean age 28.5 years) without pupil dilation were enrolled as the control group. DVA was measured binocularly with free-head viewing at 0, 30, 60, 120, and 360 min after mydriatic drop instillation in both eyes. Pupil size was measured at each time. Results: In the Mydrin P group, DVA significantly improved at 30, 60, and 120 min (ANOVA; p < .01) but returned to the predilation level at 360 min (ANOVA; p = .61). Pupil size changed from 4.1 to 7.8 mm (ANOVA; p < .01) at 30 min after the instillation, and this level was maintained up to 120 min but returned to normal within 360 min. In the control group, DVA did not significantly change at all measured times (ANOVA; p > .9). DVA was significantly ( p < .05) correlated with the pupil size at all measured times. Conclusion: The improvement in DVA was related to the enlargement of the pupil. This study suggests that the pupil size is one factor that may affect DVA. Application: Potential applications of this study include useful information to assess the effect of pupil dilation on driving performance.
Identification of Real-Time Diagnostic Measures of Visual Distraction With an Automatic Eye-Tracking System
Authors: Zhang Harry , Smith Matthew R. H. , Witt Gerald J.
Published: December 2006

Objective: This study was conducted to identify eye glance measures that are diagnostic of visual distraction. Background: Visual distraction degrades performance, but real-time diagnostic measures have not been identified. Method: In a driving simulator, 14 participants responded to a lead vehicle braking at -2 or -2.7 m/s2 periodically while reading a varying number of words (6-15 words every 13 s) on peripheral displays (with diagonal eccentricities of 24°, 43°, and 75°). Results: As the number of words and display eccentricity increased, total glance duration and reaction time increased and driving performance suffered. Conclusion: Correlation coefficients between several glance measures and reaction time or performance variables were reliably high, indicating that these glance measures are diagnostic of visual distraction. It is predicted that for every 25% increase in total glance duration, reaction time is increased by 0.39 s and standard deviation of lane position is increased by 0.06 m. Application: Potential applications of this research include assessing visual distraction in real time, delivering advisories to distracted drivers to reorient their attention to driving, and using distraction information to adapt forward collision and lane departure warning systems to enhance system effectiveness.
Does Situation Awareness Add to the Validity of Cognitive Tests?
Authors: Durso Francis T. , Bleckley M. Kathryn , Dattel Andrew R.
Published: December 2006

Objective: Does adding situation awareness (SA) to a battery of cognitive tests improve prediction? Background: Identifying variables that predict skilled performance in a complex task aids in understanding the nature of skill and also aids in the selection of operators to perform that task. SA is thought to be an important predictor of performance. SA is often thought to be based on underlying cognitive mechanisms. Method: Three performance measures taken from the Federal Aviation Administration's (FAA's) Air Traffic Scenarios Test, the low-fidelity simulation component of the FAA's controller selection battery, were used as criterion variables in a hierarchical regression. After predicting performance based on a battery of cognitive (e.g., intelligence, working memory, spatial memory) and noncognitive tests (e.g., cognitive style, personality, demographics), we added measures of SA. Results: SA did provide increases in prediction, but only when measured with the Situation Present Assessment Method, an on-line query method. When the same questions were asked off line, SA did not enter the model in two cases and improved prediction by only 2% in the third. Conclusion: Thus, some measures of SA do show incremental validity, even against a backdrop of a large number of cognitive variables. Application: On-line measures of SA can be a worthwhile addition to standard batteries of tests used to predict performance in cognitively oriented industrial tasks.
Heuristic-Based Information Acquisition and Decision Making Among Pilots
Authors: Wiggins Mark W. , Bollwerk Sandra
Published: December 2006

Objective: This research was designed to examine the impact of heuristic-based approaches to the acquisition of task-related information on the selection of an optimal alternative during simulated in-flight decision making. Background: The work integrated features of naturalistic and normative decision making and strategies of information acquisition within a computer-based, decision support framework. Method: The study comprised two phases, the first of which involved familiarizing pilots with three different heuristic-based strategies of information acquisition: frequency, elimination by aspects, and majority of confirming decisions. The second stage enabled participants to choose one of the three strategies of information acquisition to resolve a fourth (choice) scenario. Results: The results indicated that task-oriented experience, rather than the information acquisition strategies, predicted the selection of the optimal alternative. It was also evident that of the three strategies available, the elimination by aspects information acquisition strategy was preferred by most participants. Conclusion: It was concluded that task-oriented experience, rather than the process of information acquisition, predicted task accuracy during the decision-making task. It was also concluded that pilots have a preference for one particular approach to information acquisition. Application: Applications of outcomes of this research include the development of decision support systems that adapt to the information-processing capabilities and preferences of users.
Supporting Trust Calibration and the Effective Use of Decision Aids by Presenting Dynamic System Confidence Information
Authors: McGuirl John M. , Sarter Nadine B.
Published: December 2006

Objective: To examine whether continually updated information about a system's confidence in its ability to perform assigned tasks improves operators' trust calibration in, and use of, an automated decision support system (DSS). Background: The introduction of decision aids often leads to performance breakdowns that are related to automation bias and trust miscalibration. This can be explained, in part, by the fact that operators are informed about overall system reliability only, which makes it impossible for them to decide on a case-by-case basis whether to follow the system's advice. Method: The application for this research was a neural net-based decision aid that assists pilots with detecting and handling in-flight icing encounters. A multifactorial experiment was carried out with two groups of 15 instructor pilots each flying a series of 28 approaches in a motion-base simulator. One group was informed about the system's overall reliability only, whereas the other group received updated system confidence information. Results: Pilots in the updated group experienced significantly fewer icing-related stalls and were more likely to reverse their initial response to an icing condition when it did not produce desired results. Their estimate of the system's accuracy was more accurate than that of the fixed group. Conclusion: The presentation of continually updated system confidence information can improve trust calibration and thus lead to better performance of the human-machine team. Application: The findings from this research can inform the design of decision support systems in a variety of event-driven high-tempo domains.
Training for Vigilance: Using Predictive Power to Evaluate Feedback Effectiveness
Authors: Szalma James L. , Hancock Peter A. , Warm Joel S. , Dember William N. , Parsons Kelley S.
Published: December 2006

Objective: We examined the effects of knowledge of results (KR) on vigilance accuracy and report the first use of positive and negative predictive power (PPP and NPP) to assess vigilance training effectiveness. Background: Training individuals to detect infrequent signals among a plethora of nonsignals is critical to success in many failure-intolerant monitoring technologies. KR has been widely used for vigilance training, but the effect of the schedule of KR presentation on accuracy has been neglected. Previous research on training for vigilance has used signal detection metrics or hits and false alarms. In this study diagnosticity measures were applied to augment traditional analytic methods. Method: We examined the effects of continuous KR and a partial-KR regimen versus a no-KR control on decision diagnosticity. Results: Signal detection theory (SDT) analysis indicated that KR induced conservatism in responding but did not enhance sensitivity. However, KR in both forms equally enhanced PPP while selectively impairing NPP. Conclusion: There is a trade-off in the effectiveness of KR in reducing false alarms and misses. Together, SDT and PPP/NPP measures provide a more complete portrait of performance effects. Application: PPP and NPP together provide another assessment technique for vigilance performance, and as additional diagnostic tools, these measures are potentially useful to the human factors community.
Motion Extrapolation of Car-Following Scenes in Younger and Older Drivers
Authors: DeLucia Patricia R. , Mather Robert D.
Published: December 2006

Objective: The objective was to determine whether distortions occur in motion extrapolation of car-following scenes in younger and older drivers. Background: Drivers cannot see an entire traffic scene clearly with one glance. They must extrapolate the motion of surrounding vehicles while scanning other parts of the scene. Further, abilities relevant to motion extrapolation decline with age. Thus, it is important to evaluate age differences in motion extrapolation. Method: Displays simulated car-following scenes. After an interruption, the scene reappeared at the correct position in its trajectory or at a position that was more advanced or less advanced than the correct position. Drivers reported whether the scene reappeared at the correct position. Results: When the virtual self moved faster than the lead car, older drivers' judgments were biased toward less advanced reappearance positions. Younger drivers' judgments were biased toward more advanced positions. The implication is that older drivers extrapolated the motion slower than did younger drivers. Conclusion: Distortions occurred in motion extrapolation of car-following scenes, and age differences occurred in such distortions. Application: Potential applications of this research include traffic safety. Age differences in motion extrapolation are useful to consider in differential accident patterns of younger and older drivers. Future research should investigate the relationship between accidents and the ability to extrapolate motion, particularly during driver distractions.
An Accurate Method for Determining the Conspicuity Area Associated With Visual Targets
Authors: Pretorius Linda L. , Hanekom Johan J.
Published: December 2006

Objective: The objective was to develop a time-efficient method, based on an adaptive psychophysical technique, to reliably determine the boundary of the conspicuity area. Because full-field mapping is time consuming, estimating the boundary from only a limited amount of target presentations is attractive. Background: Detectability of visual targets can be evaluated by measuring their associated conspicuity areas. Earlier literature reported elliptical conspicuity areas, but later research that found shape irregularities brought into question the validity of using techniques based on this assumption to approach the area's boundary. Method: Eight participants were required to view briefly presented target-background combinations, with successive target positions depending on preceding observer responses. Results: Nonlinear least squares curve fitting showed conspicuity areas to be elliptical. Results from response time (RT) studies supported the finding, showing that slopes of RT versus eccentricity functions were markedly steeper at positions outside the conspicuity area than at those within. Conclusion: It is proposed that the developed method provides a time-efficient and accurate means to measure the conspicuity area. Application: The findings are applicable to industries in which target detectability needs to be assessed in order to either reduce (e.g., for camouflage) or enhance detectability (e.g., road safety).
Muscular Fatigue and Endurance During Intermittent Static Efforts: Effects of Contraction Level, Duty Cycle, and Cycle Time
Authors: Iridiastadi Hardianto , Nussbaum Maury A.
Published: December 2006

Objective: To determine the effects of intermittent task parameters on muscle fatigue and endurance time during static shoulder abductions, with a long-term goal of establishing relationships between intermittent task parameters and short-term performance. Background: Effects of intermittent work on endurance and fatigue development have been reported, and certain combinations of contraction levels and duty cycles have been proposed as design guidelines. These findings, however, were not derived from systematic manipulations of the task parameters. Method: Prolonged (1-hr maximum) intermittent shoulder abductions were performed at different combinations of contraction level (12% or 28% of muscle strength), duty cycle (.25 or .75), and cycle time (34 or 166 s). Fatigue was measured based on reductions in muscle strength and indirectly by changes in ratings of discomfort, electro-myographic (EMG) amplitude, and EMG spectral distribution. Results: Contraction level and duty cycle significantly affected endurance time and muscle fatigue, and interactive effects between these parameters were observed for some of the measures. Significant effects of cycle time were found only for EMG spectral measures. Conclusion: Endurance time and local fatigue were dependent on the comprehensive effects of the different task parameters. Application: Design changes to reduce the occurrence of localized fatigue during intermittent work need to take into account all the task parameters simultaneously.
Task Structure and Postcompletion Error in the Execution of a Routine Procedure
Authors: Byrne Michael D. , Davis Elizabeth M.
Published: December 2006

Objective: To replicate a successful laboratory slip-class error paradigm and, more importantly, to further understand the underlying causes of errors made in that paradigm. Background: Routine procedural errors are facts of everyday life but have received limited controlled empirical study, despite the sometimes severe consequences associated with such errors. This research concerns one such error, postcompletion error (M. D. Byrne & S. Bovair, 1997), which is a lapse that occurs after the main goal of a task has been satisfied. Method: In the two experiments conducted, participants were trained to criterion on a routine procedural task and were then brought back to the lab for a later session or sessions in which performance on task execution was measured. In the second experiment, a variety of motivational manipulations, retraining, and task redesign were compared. Results: Experiment 1 demonstrated a substantial reduction of error rate generated by a simple design change (alteration of when feedback about goal completion occurred). Furthermore, the reduction in error rate came with no penalty in terms of overall speed of performance. Experiment 2 showed that this more appropriate design is superior to motivationally oriented interventions, retraining, and even midtask redesign. As in Experiment 1, Experiment 2 revealed no speed-accuracy tradeoff. Conclusion: These experiments provide evidence that controlled laboratory studies of slip-class errors can be meaningful and highlight the centrality of cognitive factors (particularly goal structure) in such errors. Application: Potential applications include design of interfaces and their related procedures as well as error-mitigation techniques.
Age-Related Identification of Emotions at Different Image Sizes
Authors: Roring Roy W. , Hines Franklin G. , Charness Neil
Published: December 2006

Objectives: The goal of this study was to determine whether older adults are placed at a unique disadvantage in identifying emotions at small image sizes. Background: Technologies relevant to older adults often display small images, though no studies have examined whether these systems are usable for this population. Given the importance of successful emotional processing, we draw on research showing age-related difficulties in processing negative emotions to examine older adults' performance on images with reduced sizes. Methods: Sixty participants, 20 in each age group, were shown the names of emotions, followed by a facial expression, and were asked to indicate as rapidly as possible if they matched. Results: For response time we found an interaction of age and window size, showing that older adults, unlike younger adults, are slower with small sizes than with large sizes. For accuracy, we found an interaction of age and emotion, indicating that older adults are less accurate in the perception of fearful, sad, and surprised stimuli. Conclusions: Only older adults are disadvantaged by smaller images. Also, interactions of age and emotion reflect older adults' difficulty processing negative emotions. Applications: Our results have implications for the design of videoconferencing technology and mobile systems and extend previous research on aging and emotion.
Nuchal cystic hygroma in five fetuses from 1819 to 1826 in the Meckel‐anatomical collections at the University of Halle, Germany
Authors: Göbbel Luminita , Schultka Rüdiger , Klunker Rudyard , Stock Karsten , Helm Jürgen , Olsson Lennart , Opitz John M. , Gerlach Antje , Tönnies Holger
Published: December 2006

The Anatomical collection of the Department of Anatomy and Cell Biology, Medical School of the University of Halle, Germany, comprises more than 8,000 specimens. Around 600 of them show congenital anomalies. The collection of abnormal human and animal fetuses began as the private collection of Johann Friedrich Meckel the Elder (1724–1774), his son Philipp Friedrich Theodor Meckel (1755–1803) and his grandson Johann Friedrich Meckel the Younger (1781–1833). Meckel the Younger founded the systematic science of developmental pathology. Radiographical techniques, computer tomographic (CT) methods, magnetic resonance imaging (MRI), and comparative genomic hybridization (CGH) were used to diagnose abnormal human fetuses in the Meckel‐anatomical collections. Cystic hygroma colli was found in five of the human fetuses originally described by JF Meckel the Younger in 1826 and one of his students in 1819 [Hencke, 1819]. CGH analyses were used to test whether the observed cystic hygroma colli could be caused by chromosomal aneuploidies. CGH‐ratio profiles of all chromosomes were apparently normal. PCR‐based sex determination tests on ancient DNA were used to determine the fetal gonosomal constitution. It is likely that the Meckel specimens are among the oldest fetuses in which Ullrich–Turner “phenotype” has been diagnosed. © 2006 Wiley‐Liss, Inc.
Autosomal‐recessive syndrome with alopecia, hypogonadism, progressive extra‐pyramidal disorder, white matter disease, sensory neural deafness, diabetes mellitus, and low IGF1
Authors: Al‐Semari Abdulaziz , Bohlega Saeed
Published: December 2006

We explored the manifestations of an autosomal‐recessive multisystemic disorder in several Saudi families. Recognized causes of progressive extra‐pyramidal disorder and white matter disease were excluded and the neurological, imaging, endocrine, and skin manifestations of this syndrome described. The onset of these symptoms in these patients began in early adolescence and progressed more rapidly in males. All affected patients had total or partial alopecia, clinical and chemical evidence of hypogonadism (low levels of estradiol and testosterone); females had clear evidence of hypogonadism (streak or absent ovaries), and some patients had diabetes mellitus and/or sensorineural deafness. The constant biochemical abnormality was the low IGF‐1. The neurological manifestations included moderate to severe intellectual decline and abnormality of muscle tone and posture with choreo‐athetoid and dystonic movements resulting in gait difficulty, dysarthria, difficulty swallowing, and scoliosis. The MRI of brain demonstrated white matter involving cerebellum, brain stem, and cerebral structures, as well as abnormal decreased signal intensity in the basal ganglia with involvement of the substantia nigra. We conclude that the association of hypogonadism, alopecia, and persistent low IGF‐1 is a significant autosomal recessive syndrome; it is prevalent in Saudi Arabia. We also demonstrate that the progressive extra‐pyramidal disorder, white matter disease, and abnormal signals of the basal ganglia are common features of this syndrome. Sensorineural deafness and diabetes mellitus were recognized features. © 2006 Wiley‐Liss, Inc.
Linkage of schizophrenia with chromosome 1q32 in Korean multiplex families'
Authors: Jang Yong Lee , Kim Jong Won , Lee Yu‐Sang , Park Dong Yeon , Cho Eun‐Young , Jeun Hyun Ok , Lee Dongsoo , Hong Kyung Sue
Published: December 2006

Chromosome 1q contains a few loci for which modest evidence of linkage with schizophrenia has been reported in several independent studies. However, markers showing the peak linkage signal are dispersed over a large chromosomal region. In addition, inconsistent findings have been generated from different populations or different subgroups of the same populations. The purpose of the current study is to determine whether those loci are linked to schizophrenia in the Korean population. We investigated 46 Korean multiplex schizophrenia families, initially using 11 microsatellite markers spanning around 91 cM region of 1p22∼42. In a non‐parametric linkage analysis, D1S249 located on 1q32.1 showed statistical evidence suggestive of linkage. At the second stage analysis for narrowing down the region, four additional nearby markers were genotyped. In the single point analysis, we found another suggestive linkage signal at D1S2891. The highest NPL score of 2.67 (P = 0.0039) was obtained in the multi‐point analysis. This study provides supportive evidence for linkage of chromosome 1q32 with schizophrenia. © 2006 Wiley‐Liss, Inc.
Association analysis of the protein phosphatase 1 regulatory subunit 1B (PPP1R1B) gene with nicotine dependence in European‐ and African‐American smokers
Authors: Beuten Joke , Ma Jennie Z. , Lou Xiang‐Yang , Payne Thomas J. , Li Ming D.
Published: December 2006

The protein phosphatase 1 regulatory subunit 1B gene (PPP1R1B; also known as dopamine and cAMP‐regulated phosphoprotein; DARPP32) is a target for the actions of dopamine. Because the mesolimbic dopaminergic system is implicated in the reinforcing effects of many drugs, including nicotine,PPP1R1Bis considered a plausible candidate for involvement in the development of vulnerability to nicotine dependence (ND). Further, this gene is located within a region on chromosome 17 that demonstrated “suggestive linkage” to ND in our previous genome‐wide scan. In the present study, we analyzed six single nucleotide polymorphisms (SNPs) withinPPP1R1Bfor association with three ND measures: smoking quantity (SQ), the heaviness of smoking index (HSI), and the Fagerström Test for ND (FTND) score. Our sample consisted of 602 nuclear families of African‐American (AA) or European‐American (EA) origin. No significant associations were found for single SNPs after correction for multiple testing. However, haplotype analysis indicated that in the EA sample, the C‐T‐G‐C haplotype formed by rs2271309‐rs907094‐rs3764352‐rs3817160 with a frequency of 32.0% was significantly associated with SQ (Z = 2.50;P = 0.01), even after Bonferroni correction. No significant associations with haplotypes were found in the AA sample. In summary, our findings provide the first evidence for the potential involvement ofPPP1R1Bin the etiology of ND and further investigation is thus warranted. © 2006 Wiley‐Liss, Inc.
Sequence variants within exon 1 of MECP2 occur in females with mental retardation
Authors: Harvey Chris G. , Menon Sailesh D. , Stachowiak Beata , Noor Abdul , Proctor Adam , Mensah Albert K. , Mnatzakanian Gevork N. , Alfred Simon E. , Guo Ray , Scherer Stephen W. , Kennedy James L. , Roberts Wendy , Srivistava Anand K. , Minassian Berge A. , Vincent John B.
Published: December 2006

A new splice variant of the Rett syndrome gene, MECP2, was recently identified, that includes coding sequence from exon 1, and is the predominant transcript in the central nervous system. This sequence encodes polyalanine and polyglycine stretches within the N‐terminal portion of MeCP2, and may confer novel functional properties to the protein. We screened autism, mental retardation (MR), and control populations for sequence variation within this region, and identified variation in ∼1% of MR cases screened (N = 1,410). No variants were identified in the autism sample (N = 401). Most of these variants occur within a trinucleotide repeat region and result in change in number of alanine or glycine residues within the repeat stretches. We suggest some of these variants may be a relatively frequent cause of non‐specific MR or developmental delay. © 2006 Wiley‐Liss, Inc.
Oligodendroglial transcription factor (OLIG1 and OLIG2) mutations are not associated with Pelizaeus–Merzbacher‐like leukodystrophy
Authors: Ruf Nico , Martelli Mara , Weschke Bernhard , Uhlenberg Birgit
Published: December 2006

The human phenotype with primarily impaired myelination is represented by hypomyelinating leukodystrophies. The most frequent form is Pelizaeus–Merzbacher disease, which is due to alterations in the PLP1 gene encoding the major myelin protein. Another form, Pelizaeus–Merzbacher‐like disease, is partly associated with mutations in the GJA12 gene encoding gap junction protein alpha 12, but seems to be heterogeneous. Olig1 and Olig2 are transcription factors in oligodendrocyte development. We postulated that disturbed oligodendroglial maturation could be associated with primary hypomyelination in humans and analyzed the coding sequence of OLIG1 and OLIG2 in 13 patients from 12 unrelated families which were thoroughly characterized with regard to phenotype and magnetic resonance imaging results. From our findings we conclude that mutations in OLIG1 and OLIG2 are not likely to be associated with this subgroup of hypomyelinating disorders. © 2006 Wiley‐Liss, Inc.
Cyclooxygenase‐2 polymorphisms in Parkinson's disease
Authors: Håkansson Anna , Bergman Olle , Chrapkowska Cecilia , Westberg Lars , Belin Andrea Carmine , Sydow Olof , Johnels Bo , Olson Lars , Holmberg Björn , Nissbrandt Hans
Published: December 2006

Accumulating evidence indicate that cyclooxygenase‐2 (COX‐2) is of pathophysiological importance for the neurodegeneration in Parkinson's disease (PD). For example, in a large epidemiological study, use of NSAIDs was associated with a lower risk of PD. Genetic variants of the COX‐2 gene might therefore influence the risk of developing the disease. The genotype distribution of four common single nucleotide polymorphisms (SNPs) in the COX‐2 gene (rs689466:A496G, rs20417:G926C, rs5277:G3050C, rs5275:C8473T) was analyzed in PD patients and control subjects in a Swedish population. No differences could be seen between the PD‐patient and controls regarding the A496G, G926C, and G3050C SNPs, but the allele frequency of the C8473T SNP was found to differ when male patients were compared to controls (P = 0.007). In females no difference could be seen between PD‐patients and controls. In conclusion, the results suggest a possible influence of the COX‐2 C8473T SNP in PD, although it only seems to be of importance in men. © 2006 Wiley‐Liss, Inc.
Association of the dopamine receptor D4 (DRD4) gene 7‐repeat allele with children with attention‐deficit/hyperactivity disorder (ADHD): An update
Authors: Gornick M.C. , Addington Anjene , Shaw P. , Bobb A.J. , Sharp W. , Greenstein D. , Arepalli S. , Castellanos F.X. , Rapoport J.L.
Published: December 2006

Polymorphisms of the dopamine receptor D4 gene DRD4, 11p15.5, have previously been associated with attention‐deficit/hyperactivity disorder (ADHD) [Bobb et al., 2005; Am J Med Genet B Neuropsychiatr Genet 132:109–125; Faraone et al., 2005; Biol Psychiatry 57:1313–1323; Thapar et al., 2005; Hum Mol Genet 14 Spec No. 2:R275‐R282]. As a follow up to a pilot study [see Castellanos et al., 1998; Mol Psychiatry 3:431–434] consisting of 41 probands and 56 controls which found no significant association between the DRD4 7‐repeat allele in exon 3 and ADHD, a greatly expanded study sample (cases n = 166 and controls n = 282) and long term follow‐up (n = 107, baseline mean age n = 9, follow‐up mean age of n = 15) prompted reexamination of this gene. The DRD4 7‐repeat allele was significantly more frequent in ADHD cases than controls (OR = 1.2; P = 0.028). Further, within the ADHD group, the 7‐repeat allele was associated with better cognitive performance (measured by the WISC‐III) (P = 0.013–0.07) as well as a trend for association with better long‐term outcome. This provides further evidence of the role of the DRD4 7‐repeat allele in the etiology of ADHD and suggests that this allele may be associated with a more benign form of the disorder. © 2006 Wiley‐Liss, Inc.
Preliminary evidence for linkage to chromosome 1q31‐32, 10q23.3, and 16p13.3 in a South African cohort with bipolar disorder
Authors: Savitz Jonathan , Cupido Cinda‐Lee , Ramesar Raj Kumar
Published: December 2006

Although the genetic variants predisposing to the development of bipolar disorder (BPD) have yet to be conclusively identified, replicated reports of linkage to particular chromosomal regions have been encouraging. Here we carried out a non‐parametric linkage analysis of nine of these candidate loci in a unique South African sample of 47 BPD pedigrees (N = 350). Three polymorphic markers per region of interest (3 × 9) were typed in a Caucasian cohort of Afrikaner and British origin. Statistically significant evidence for linkage was obtained at 1q31‐32, 10q23.3, and 16p13.3 with maximum NPL scores of 2.52, 2.01, and 1.84, respectively. Our results add to the growing evidence that these chromosomal regions harbor genetic variants that play a role in the development of bipolar spectrum illness. Negative results were obtained for the remaining six candidate loci, possibly due to limited statistical power. © 2006 Wiley‐Liss, Inc.
Dopaminergic polymorphisms in Tourette syndrome: Association with the DAT gene (SLC6A3)
Authors: Yoon Dustin Y. , Rippel Christopher A. , Kobets Andrew J. , Morris Christina M. , Lee Jennifer E. , Williams Phillip N. , Bridges Dana D. , Vandenbergh David J. , Shugart Yin Y. , Singer Harvey S.
Published: December 2006

Tourette syndrome (TS) is a chronic neuropsychiatric disorder characterized by involuntary motor and phonic tics. The pattern of inheritance and associated genetic abnormality has yet to be fully characterized. A dopaminergic abnormality in this disorder is supported by response to specific therapies, nuclear imaging, and postmortem studies. In this protocol, dopaminergic polymorphisms were examined for associations with TS and attention‐deficit hyperactivity disorder (ADHD). Polymorphisms investigated included the dopamine transporter (DAT1DdeI and DAT1 VNTR), dopamine receptor (D4 Upstream Repeat and D4 VNTR), dopamine converting enzyme (dopamine β‐hydroxylase), and the acid phosphatase locus 1 (ACP1) gene. DNA was obtained from 266 TS individuals ± ADHD and 236 controls that were ethnicity‐matched. A significant association, using a genotype‐based association analysis, was identified for the TS‐total and TS‐only versus control groups for the DAT1DdeI polymorphism (AG vs. AA,P = 0.004 andP = 0.01, respectively). Population structure, estimated by the genotyping of 27 informative SNP markers, identified 3 subgroups. A statistical re‐evaluation of the DAT1DdeI polymorphism following population stratification confirmed the association for the TS‐total and TS‐only groups, but the degree of significance was reduced (P = 0.017 andP = 0.016, respectively). This study has identified a significant association between the presence of TS and a DAT polymorphism. Since abnormalities of the dopamine transporter have been hypothesized in the pathophysiology of TS, it is possible that this could be a functional allele associated with clinical expression. © 2006 Wiley‐Liss, Inc.
HOXA1 gene variants influence head growth rates in humans
Authors: Muscarella Lucia Anna , Guarnieri Vito , Sacco Roberto , Militerni Roberto , Bravaccio Carmela , Trillo Simona , Schneider Cindy , Melmed Raun , Elia Maurizio , Mascia Maria Lucia , Rucci Emanuela , Piemontese Maria Rosaria , D'Agruma Leonardo , Persico Antonio M.
Published: December 2006

We previously described a significant association between the HOXA1 G218 allele and increased head circumference in autism [Conciatori et al. (2004); Biol Psychiatry 55:413–419]. The present study reveals identical effects also in normal children. HOXA1 A218G alleles and sex explain as much as 10.9 and 6.8% of the variance in head circumference in 142 pediatric controls and in 191 autistic children, aged 3–16 years (F = 6.777, 3 and 141 df, P < 0.001 and F = 5.588, 3 and 190 df, P < 0.01, respectively). Instead, no association is found in 183 adult controls and in 35 pediatric fragile‐X patients. Therefore HOXA1 A218G alleles significantly influence head growth rates, but not final head size, in normal human development. This influence does not differ between normal and autistic children, whereas the lack of FMRP seemingly overwhelms HOXA1 effects in fragile‐X patients. © 2006 Wiley‐Liss, Inc.
No significant association between response to methylphenidate and genes of the dopaminergic and serotonergic systems in a sample of Brazilian children with attention‐deficit/hyperactivity disorder
Authors: Zeni Cristian Patrick , Guimarães Ana Paula , Polanczyk Guilherme V. , Genro Julia P. , Roman Tatiana , Hutz Mara H. , Rohde Luis Augusto
Published: December 2006

Few studies on pharmacogenetics of Attention‐Deficit/Hyperactivity Disorder (ADHD) have been conducted. Most of them evaluated dopaminergic genes resulting in positive and negative findings. We assessed effects of polymorphisms in candidate dopaminergic (DRD4, DAT1) and serotonergic genes (HTR1B, HTR2A, and 5‐HTT) on the response to treatment in 111 patients for whom methylphenidate (MPH) was prescribed. Outcome measures (Swanson, Nolan, and Pelham scale—version IV, Children Global Assessment Scale, Barkley's Stimulants Side Effects Rating Scale) were assessed at baseline and 1 month after the intervention. No significant association was detected between polymorphisms assessed and both response and side effects to MPH. Prospective multi‐site controlled studies with larger sample sizes are needed in order to disentangle the role of candidate genes in response to ADHD treatment. © 2006 Wiley‐Liss, Inc.
Phylogenetic relationships among the Lorisoidea as indicated by craniodental morphology and mitochondrial sequence data
Authors: Masters Judith C. , Boniotto Michele , Crovella Sergio , Roos Christian , Pozzi Luca , Delpero Massimiliano
Published: December 2006

The phylogeny of the Afro‐Asian Lorisoidea is controversial. While postcranial data attest strongly to the monophyly of the Lorisidae, most molecular analyses portray them as paraphyletic and group the Galagidae alternately with the Asian or African lorisids. One of the problems that has bedevilled phylogenetic analysis of the group in the past is the limited number of taxa sampled for both ingroup families. We present the results of a series of phylogenetic analyses based on 635 base pairs (bp) from two mitochondrial genes (12S and 16S rRNA) with and without 36 craniodental characters, for 11 galagid and five lorisid taxa. The outgroup was the gray mouse lemur (Microcebus murinus). Analyses of the molecular data included maximum parsimony (MP), neighbor joining (NJ), maximum likelihood (ML), and Bayesian methods. The model‐based analyses and the combined “molecules+morphology” analyses supported monophyly of the Lorisidae and Galagidae. The lorisids form two geographically defined clades. We find no support for the taxonomy of Galagidae as proposed recently by Groves [Primate Taxonomy, Washington, DC: Smithsonian Institution Press. 350 p, 2001]. The taxonomy of Nash et al. [International Journal of Primatology 10:57–80, 1989] is supported by the combined “molecules+morphology” analysis; however, the model‐based analyses suggest that Galagoides may be an assemblage of species united by plesiomorphic craniodental characters. Am. J. Primatol. 69:6–15, 2007. © 2006 Wiley‐Liss, Inc.
Comparative penile morphology of East African galagos of the genus Galagoides (family Galagidae): implications for taxonomy
Authors: Perkin Andrew
Published: December 2006

Recent studies on the comparative penile morphology of galagos have revealed complex patterns that vary among both genera and species, and help with species identification. So far the penile morphologies of 14 galago species have been described and an identification key has been proposed. The present study extends and revises previous work. Wild Galagoides cocos, G. granti, G. zanzibaricus and G. rondoensis from the Eastern Arc Mountains and coastal forests of Tanzania and Kenya were live‐trapped, and one species (G. orinus) was examined using a museum specimen. Penile morphology was photographed, traced, and described qualitatively. All of the mature males had penile spines. Spines were absent or indistinct in immature males of all of the species. The penile morphologies of G. cocos, G. granti, and G. zanzibaricus are similar in their overall distribution and type of spines, but differ in the shape of the glans penis. Both G. orinus and G. rondoensis have divergent penile morphologies compared to all other galagos, and are probably phylogenetically distinct. The results support other recent morphological and behavioral studies that consider these five galagos to be distinct species. The evolution of the baculum and spines is thought to be linked to sexual selection in multimale mating systems, but the mechanisms involved are not entirely understood. Adult male G. rondoensis appear to display the penile spines by exposing the distal section of the penis. Am. J. Primatol. 68:16–26, 2007. © 2006 Wiley‐Liss, Inc.
Early evolution and biogeography of lorisiform strepsirrhines
Authors: Seiffert Erik R.
Published: December 2006

This brief review summarizes new paleontological and molecular data that together support a late middle Eocene Afro‐Arabian origin for crown Lorisiformes. Phylogenetic analysis indicates that late Eocene Karanisia is a possible stem lorisiform, late Eocene Saharagalago and Wadilemur and Miocene Komba are stem galagids, and early Miocene Mioeuoticus and Progalago may be crown lorisids. Character evolution along the lorisid and galagid stem lineages is reconstructed as having occurred primarily in postcranial and dental morphology, respectively. These patterns have important implications for interpreting an early lorisiform fossil record that is still composed primarily of jaws and isolated teeth. Am. J. Primatol. 69:27–35, 2007. © 2006 Wiley‐Liss, Inc.
Histomorphology of the mandibular condylar cartilage in greater galagos (Otolemur spp.)
Authors: Burrows Anne M. , Smith Timothy D.
Published: December 2006

The functional morphology of the primate craniomandibular complex and temporomandibular joint (TMJ) components is frequently discussed in terms of gross skeletal structure. At the histomorphologic level, however, the TMJ has only been studied in Old World anthropoids. The present study is designed to describe the microanatomy of the condylar cartilage of the TMJ in two closely related species of greater galago: the exudativorous Otolemur crassicaudatus and the frugivorous O. garnettii. TMJs with intact joint capsules were harvested from adult, cadaveric specimens of these species (four O. crassicaudatus and five O. garnettii). The samples were decalcified, processed for paraffin sectioning, and sectioned at 10–18 µm in the coronal plane. The samples were then stained with hematoxylin/eosin, Gomori trichrome, and Alcian blue, and examined with a photomicroscope. Generally, condylar cartilage in O. crassicaudatus was thickest both laterally and centrally, while O. garnettii had the relatively thickest cartilage laterally. Both species displayed a superficial articular zone, a middle proliferative zone, and a deeply located hypertrophic zone in the condylar cartilage. O. crassicaudatus typically had the greatest cell density in each of these zones. In addition, O. crassicaudatus had focal concentrations of Alcian blue laterally and centrally, while O. garnettii had the greatest reactivity in the central portion only. These results suggest that O. crassicaudatus may be specialized to resist greater compressive force at the TMJ condylar cartilage in specific regions of the mandibular condyle. Am. J. Primatol. 69:36–45, 2007. © 2006 Wiley‐Liss, Inc.
Interspecific analysis of covariance structure in the masticatory apparatus of galagos
Authors: Vinyard Christopher J.
Published: December 2006

The primate masticatory apparatus (MA) is a functionally integrated set of features, each of which performs important functions in biting, ingestive, and chewing behaviors. A comparison of morphological covariance structure among species for these MA features will help us to further understand the evolutionary history of this region. In this exploratory analysis, the covariance structure of the MA is compared across seven galago species to investigate 1) whether there are differences in covariance structure in this region, and 2) if so, how has this covariation changed with respect to size, MA form, diet, and/or phylogeny? Ten measurements of the MA functionally related to bite force production and load resistance were obtained from 218 adults of seven galago species. Correlation matrices were generated for these 10 dimensions and compared among species via matrix correlations and Mantel tests. Subsequently, pairwise covariance disparity in the MA was estimated as a measure of difference in covariance structure between species. Covariance disparity estimates were correlated with pairwise distances related to differences in body size, MA size and shape, genetic distance (based on cytochrome‐b sequences) and percentage of dietary foods to determine whether one or more of these factors is linked to differences in covariance structure. Galagos differ in MA covariance structure. Body size appears to be a major factor correlated with differences in covariance structure among galagos. The largest galago species, Otolemur crassicaudatus, exhibits large differences in body mass and covariance structure relative to other galagos, and thus plays a primary role in creating this association. MA size and shape do not correlate with covariance structure when body mass is held constant. Diet also shows no association. Genetic distance is significantly negatively correlated with covariance disparity when body mass is held constant, but this correlation appears to be a function of the small body size and large genetic distance for Galagoides demidoff. These exploratory results indicate that changing body size may have been a key factor in the evolution of the galago MA. Am. J. Primatol. 69:46–58, 2007. © 2006 Wiley‐Liss, Inc.
Cranial ontogeny, diet, and ecogeographic variation in African lorises
Authors: Ravosa Matthew J.
Published: December 2006

A series of 22 craniodental measurements were obtained for the three subspecies of potto (Perodicticus) and angwantibos (Arctocebus). To describe patterns of variation in Perodicticus, a discriminant function analysis (DFA) was performed with adult data. To investigate the ecogeographic correlates of size variation in Perodicticus, adult cranial dimensions were compared with field data on latitudinal and longitudinal coordinates for available specimens as well as altitudinal data for a more limited sample. Ontogenetic series for larger‐bodied Perodicticus and smaller‐bodied Arctocebus were compared to test the hypothesis that inter‐ and intrageneric variation in skull form results from the differential extension/truncation of shared patterns of relative growth, and to assess morphological variation in the masticatory complex of sister taxa with differing dietary habits. Analyses of relative growth indicate that skull proportions in Perodicticus subspecies are largely ontogenetically scaled. In comparisons between Perodicticus and Arctocebus, most facial dimensions also are ontogenetically scaled, with all but one of the seven divergent comparisons (interorbital breadth) representing a feature of the masticatory apparatus. The DFA provided independent support for prior classifications of Perodicticus into three taxa. Size differentiation in African lorises appears to be correlated with altitudinal variation (Bergmann's Rule) as well as character displacement. The smallest pottos, P. p. potto, occupy low‐lying coastal habitats in western Africa, whereas the larger, eastern forms inhabit higher, presumably colder elevations. The largest potto, P. p. edwardsi, is sympatric throughout most of its range with the smallest and most insectivorous African lorises (Arctocebus). A basis for intrageneric taxonomic variation in Perodicticus is supported by such nonclinal size variation, as well as divergences in the ontogeny of masticatory proportions corresponding to interspecific variation in dietary proclivities. Am. J. Primatol. 69:59–73, 2007. © 2006 Wiley‐Liss, Inc.