General Motors Research Articles

Cross-replicating findings on unique motor impairments of children with ASD using confirmatory factor analysis and a novel SPARK study sample.

A series of recent reports have shed light on the pervasive nature of motor impairments in children with ASD (Bhat, 2020, 2021, Bhat et al., 2022), underscoring the importance of providing ASD clinicians efficient and accurate tools for motor screening. The Developmental Coordination Disorder-Questionnaire (DCD-Q) is a widely used motor screening tool, yet scant evidence exists regarding its psychometric properties in children with ASD. In a recent Exploratory Factor Analysis (EFA) of the 15-item DCD-Q in a large sample of children with ASD (SPARK study), we found a 5-factor latent structure that identified unique motor impairments in a large sample of children with ASD (Bhat et al., 2022). In the current study, we extend this work by cross-replicating the EFA findings of unique ASD-related motor issues using Confirmatory Factor Analysis (CFA) in a new, more recent wave of children with ASD from the SPARK study (N=9721). The fits and interpretability of 11 hypothesis-driven CFA models, including 8 correlated-factors, 1second-order, and 2 bifactor models were compared. Our findings supported the previous 5-factor model with 2 gross motor subdomains, 1 fine motor domain (similar to the original DCD-Q) and 2 general coordination subdomains. This model demonstrated acceptable fit in the new sample as well as superior fit compared to several other parsimonious correlated-factors models. However, the second-order and bifactor models fit slightly better and supported the presence of a general motor skills factor, although 38% of the common variance in the DCD-Q items remained attributable to the 5 subdomains. Using one of the bifactor models, measurement invariance was also supported for DCD-Q across sex, race, and co-occurring conditions of language disorder and intellectual disability. Only partial invariance was supported when testing DCD-Q scores across different age groups. These findings reveal a more complex dimensional picture of the DCD-Q in children with ASD. Results suggest that the DCD-Q can be used in two ways, total scores adequately assess general motor skills for brief screening and subdomain scores offer unique information on the multidimensional motor problems of children with ASD. If subdomain data are of interest, our findings call into question the practice of relying on 3 original subscales of the DCD-Q when screening for ASD-related motor difficulties, whereas 4 out of 5 subscale scores may better highlight domain-specific motor problems. Future studies should continue to further validate DCD-Q's ability to screen for multidimensional motor problems.

The effect of peptide bioregulators on the resistance of rats to cold-stress factor

BACKGROUND: Biologically active regulatory peptides are the drugs of new type that act selectively on targets, with having no significant side effects.
 AIM: The aim of the study was to study the potential effect of peptide preparations Cortexin and Semax on the resistance of the rat organism to the cold stress factor in the model of cold stress maladaptation.
 MATERIALS AND METHODS: White outbred male rats were injected intraperitoneally twice daily with placebo (n = 30), Cortexin 5 mg/kg (n = 30) or Semax 0.3 mg/kg (n = 30). Three days after the start of the injection course, the cold-stress effect was simulated in the climate chamber (Feutron, Germany) by cooling the air to 5C at a relative humidity of 7580%.
 RESULTS: The use of RP significantly increased the duration of the rectal temperature plateau-period within 35C (moderate hypothermia): in animals of the Cortexin group from 10 days to 12 days, and in animals of the Semax group, from 10 to 14 days. Cortexin demonstrated moderate immunomodulatory properties, and Semax had a more pronounced immunomodulatory effect. Both preparations showed a stress-protective effect. The use of regulatory peptides provided to delay the decrease in the rat general motor activity and exploratory behavior which develops under the influence of a simulated cold-stress factor. A slower rate of decrease in the swimming time of rats under the influence of regulatory peptides was registrated.
 CONCLUSIONS: The meteoadaptogenic, stress-protective and nootropic effects of the regulatory peptides Cortexin and Semax were confirmed in rats on the model of cold-stress maladaptation.

Special issue on all‐electric and hybrid‐electric flight

Special issue on all‐electric and hybrid‐electric flight

Behavioral and transcriptomic effects of the cancer treatment tamoxifen in mice.

Tamoxifen is a common treatment for estrogen receptor-positive breast cancer. While tamoxifen treatment is generally accepted as safe, there are concerns about adverse effects on cognition. We used a mouse model of chronic tamoxifen exposure to examine the effects of tamoxifen on the brain. Female C57/BL6 mice were exposed to tamoxifen or vehicle control for six weeks; brains of 15 mice were analyzed for tamoxifen levels and transcriptomic changes, and an additional 32 mice were analyzed through a battery of behavioral tests. Tamoxifen and its metabolite 4-OH-tamoxifen were found at higher levels in the brain than in the plasma, demonstrating the facile entry of tamoxifen into the CNS. Behaviorally, tamoxifen-exposed mice showed no impairment in assays related to general health, exploration, motor function, sensorimotor gating, and spatial learning. Tamoxifen-treated mice showed a significantly increased freezing response in a fear conditioning paradigm, but no effects on anxiety measures in the absence of stressors. RNA sequencing analysis of whole hippocampi showed tamoxifen-induced reductions in gene pathways related to microtubule function, synapse regulation, and neurogenesis. These findings of the effects of tamoxifen exposure on fear conditioning and on gene expression related to neuronal connectivity suggest that there may be CNS side effects of this common breast cancer treatment.

Review: Tainted Tap: Flint’s Journey from Crisis to Recovery, by Katrinell M. Davis

Review: <i>Tainted Tap: Flint’s Journey from Crisis to Recovery</i>, by Katrinell M. Davis

Prevalence and Risk Factors for Intensive Care Unit Delirium After Traumatic Brain Injury: A Retrospective Cohort Study.

Delirium remains understudied after traumatic brain injury (TBI). We sought to identify independent predictors of delirium among intensive care unit (ICU) patients with TBI. This single-center retrospective cohort study evaluated adult patients with TBI requiring ICU admission. Outcomes included delirium days within the first 14days, as assessed by the Confusion Assessment Method-ICU (CAM-ICU). Models were adjusted for age, sex, insurance, Marshall head computed tomography classification, presence of subarachnoid hemorrhage (SAH), Injury Severity Score (ISS), need for cardiopulmonary resuscitation, maximum admission Glasgow Coma motor score, glucose level, hemoglobin level, and pupil reactivity. Delirium prevalence was 60%, with a median duration of 4days (interquartile range: 2-8) among ICU patients with TBI (n = 2,664). Older age, higher ISS, maximum motor score < 6, Marshall class II-IV, and SAH were associated with risk of increased delirium duration (all p < 0.001). In this large cohort, ICU delirium after TBI affected three of five patients for a median duration of 4days. Age, general injury severity, motor score, and features of intracranial hemorrhage were predictive of more TBI-associated delirium days. Given the high prevalence of ICU delirium after TBIand itsimpact on hospitalization, further work is needed to understand the impact of delirium and TBI on outcomes and to determine whether delirium risk can be minimized.

Similar Cognitive Skill Impairment in Children with Upper Limb Motor Disorders Due to Arthrogryposis Multiplex Congenita and Obstetrical Brachial Plexus Palsy.

Arthrogryposis multiplex congenita (AMC) and obstetrical brachial plexus palsy (OBPP) are motor disorders with similar symptoms (contractures and the disturbance of upper limb function). Both conditions present as flaccid paresis but differ from each other in the pathogenesis: AMC is a congenital condition, while OBPP results from trauma during childbirth. Despite this difference, these diseases are identical in terms of their manifestations and treatment programmes. We compared the cognitive skills of children with AMC and OBPP diagnoses with those of healthy children; we also compared the motor skills of impaired children with those of healthy ones. The patients in both groups significantly differed from the healthy children with regard to psychological parameters, such as 'visual memory capacity' and 'thinking'. Moreover, the two groups with children with AMC and OBPP significantly differed from each other in motor skill parameters, such as 'delayed motor development', 'general motor development', and the 'level of paresis'. Upper limb motor function in the OBPP children was less impaired compared to that of the AMC children. However, we did not find any significant differences in cognitive deficits between the AMC children and the OBPP children. This may indicate that motor impairment is more significant than the underlying cause for the development of cognitive impairment; however, the factors causing this phenomenon require further study (e.g., social environment, treatment, and rehabilitation programme).

Griscelli syndrome type 1: a novel pathogenic variant, and review of literature.

Griscelli syndrome type 1 (GS1) is a rare inherited autosomal recessive disease caused by a deleterious variant in the MYO5A gene and characterized by general hypopigmentation, neurological symptoms, motor disability, hypotonia, and vision abnormality. Only nine pathogenic variants in the MYO5A gene have been confirmed in association with the GS1. All of the reported pathogenic variants are truncating. Herein, two siblings from a consanguineous Iranian family with abnormal pigmentation and neurological symptoms were referred for genetic counseling. Whole-exome sequencing (WES) revealed a novel homozygous truncating variant c.1633_1634delAA (p.Asn545Glnfs*10) in the MYO5A gene, which was completely co-segregated with the phenotype in all affected and unaffected family members. Computational analysis and protein modeling demonstrated the deleterious effects of this variant on the structure and function of the protein. The variant, according to ACMG guidelines, was classified as pathogenic. Besides the novelty of the identified variant, our patients manifested more severe clinical symptoms and presented distal hyperlaxity in all four limbs, which was a new finding. In conclusion, we expanded the mutational and phenotypic spectrum of the GS1. Moreover, by studying clinical manifestations in all molecularly confirmed reported cases, provided a comprehensive overview of clinical presentation, and attempted to find a genotype-phenotype correlation.

EVALUATION OF MITOCHONDRIAL AND NEUROBEHAVIORAL DISORDERS IN BRAIN REGIONS OF OFFSPRING (F1, F2) AFTER GESTATING AND LACTATING FEMALE RATS EXPOSURE TO LOW-DOSE OF IMIDACLOPRID AND CYPERMETHRIN

The imidacloprid (IMID) and cypermethrin (CYP) pesticides are known to have neurotoxic effects and negative brain developmental consequences when used separately, but little is known about the consequences of using them as a mixture. That could be passed down from one generation to the next. In this context, we were interested in studying the effect of oral exposure of female rats during gestation and throughout the lactational period to real doses of IMID (1.2 mg/kg) and CYP (6.7 mg/kg) either alone or in a mixture on behavior and mitochondrial redox status. The first and second generation pups were followed from birth to juvenile age using a series of tests to assess reflex, coordination and general motor function, including surface righting, cliff aversion, negative geotaxis and the muscle strength test. At PND 21, cholinergic function, oxidative stress and mitochondrial integrity were assessed in the striatum and hippocampus. Our results showed that IMID and CYP, alone or in combination, induced decreased body weight gain, impaired neurobehavioral performance, and AchE inhibition. Oxidative stress markers including GSH level and SOD, CAT, GST and GPx activities showed a significant decrease. While, lipid peroxidation which was assessed by MDA assay, cytosolic calcium level, swelling and mitochondrial permeability recorded a significant increase. In conclusion, the disruption of mitochondrial redox homeostasis and the presence of neurobehavioral disorders even in the offspring of the F2 generation suggests that independent and combined exposure to IMID and CYP during a critical period of development has irreversible effects; long-lasting and persistent.

Bandura's Observational Learning Model and General Motoric Ability About Learning Outcomes in Athletic Skills

&lt;p style="text-align: justify;"&gt;This study aims to analyze the impact of Bandura’s observational learning model based on performance assessment learning models and general motor skills on athletic skills learning outcomes. This study used an experimental design treatment by level 2x2. A simple random sampling technique was used with a total of 88 people. The data collection method used consisted of tests and documentation. A two-way analysis of variance was used to analyze the data. The results showed that the students’ athletic skills learning outcomes that followed the Bandura observational learning model based on performance assessment were higher than students’ conventional learning model. There was an interaction effect between the learning model and general motor skills on the student's athletic skills learning outcomes. The students’ athletic skills learning outcomes who follow the Bandura observational learning model based on performance assessment were higher than the conventional learning model. The students with low general motor skills and the students’ athletic skills learning outcomes that followed the Bandura observational learning model based on performance assessment were lower than the conventional learning model. Based on the research findings, it is recommended to improve the athletic skills learning outcomes with Bandura's observational learning model based on performance assessments appropriately and correctly.&lt;/p&gt;

A Study on the Control Method of 6-DOF Magnetic Levitation System Using Non-Contact Position Sensors

Recently, due to the development of semiconductor technology, high-performance memory and digital convergence technology that integrates and implements various functions into one semiconductor chip has been regarded as the next-generation core technology. In the semiconductor manufacturing process, various motors are being applied for automated processes and high product reliability. However, dust and shaft loss due to mechanical friction of a general motor system composed of motor-bearing are problematic for semiconductor wafer processing. In addition, in the edge bread remove (EBR) process after the photoresist application process, a nozzle position control system for removing unnecessary portions of the wafer edge is absolutely necessary. Therefore, in this paper, in order to solve the problems occurring in the semiconductor process, a six-degrees-of-freedom (6-DOF) magnetic levitation system without shaft and bearing was designed for application to the semiconductor process system; and an integrated driving control algorithm for 6-DOF control (levitation, rotation, tilt (Roll-Pitch), X-Y axis movement) using the force of each current component derived through current vector control was proposed. Finally, the 6-DOF magnetic levitation system with the non-contact position sensors was fabricated and the validity of the 6-DOF magnetic levitation control method proposed in this paper was verified through a performance test using a prototype.

The influence of share buybacks on ill-health and health inequity: an exploratory analysis using a socio-ecological determinants of health lens

IntroductionShare buybacks, when a corporation buys back its own shares, are recognised as having potentially harmful impacts on society. This includes by contributing to economic inequalities, and by impeding investments with the potential to protect and promote the welfare of various stakeholders. Share buybacks, however, have received minimal analytical attention in the public health literature. This paper aimed to explore the potential influence of share buybacks on population health and health inequity using a socio-ecological determinants of health lens.MethodsWe conducted a descriptive analysis of share buybacks made by corporations listed on United States (US) stock exchanges between 1982 and 2021, using quantitative data sourced from Compustat. We examined annual trends in share buyback expenditure, including comparisons to dividend, net income, capital expenditure, and research and development expenditure data. We then purposively sampled a set of corporations to provide illustrative examples of how share buybacks potentially influence key socio-ecological determinants of health. The examples were: i) three COVID-19 vaccine manufacturers; ii) five of the world’s largest fossil fuel corporations; and iii) US car manufacturer General Motors. For these, we conducted an analysis of data from Compustat, company reports and grey literature materials, focusing on key sources of profits and their allocation to share buybacks and particular investments.ResultsUS-listed corporations spent an estimated US$9.2 trillion in real terms on share buybacks between 2012 and 2021 (nearly 12 times more than from 1982 to 1991). The contribution of share buybacks to total shareholder ‘returns’ increased from 11% in 1982 to 55% in 2021, with expenditure on shareholder returns increasing considerably relative to capital, research and development expenditure over this period. The three examples illustrated how some corporations have prioritised the short-term financial interests of their shareholders, including via implementing large share buyback programs, over investments with considerable potential to protect and promote the public’s health.ConclusionThe potentially substantial impacts of share buybacks on health warrant increased research and policy attention. Arguably, more must be done to regulate share buybacks as part of efforts to address the corporate drivers of ill-health and inequity.

Speech and Nonspeech Parameters in the Clinical Assessment of Dysarthria: A Dimensional Analysis.

Nonspeech (or paraspeech) parameters are widely used in clinical assessment of speech impairment in persons with dysarthria (PWD). Virtually every standard clinical instrument used in dysarthria diagnostics includes nonspeech parameters, often in considerable numbers. While theoretical considerations have challenged the validity of these measures as markers of speech impairment, only a few studies have directly examined their relationship to speech parameters on a broader scale. This study was designed to investigate how nonspeech parameters commonly used in clinical dysarthria assessment relate to speech characteristics of dysarthria in individuals with movement disorders. Maximum syllable repetition rates, accuracies, and rates of isolated and repetitive nonspeech oral-facial movements and maximum phonation times were compared with auditory-perceptual and acoustic speech parameters. Overall, 23 diagnostic parameters were assessed in a sample of 130 patients with movement disorders of six etiologies. Each variable was standardized for its distribution and for age and sex effects in 130 neurotypical speakers. Exploratory Graph Analysis (EGA) and Confirmatory Factor Analysis (CFA) were used to examine the factor structure underlying the diagnostic parameters. In the first analysis, we tested the hypothesis that nonspeech parameters combine with speech parameters within diagnostic dimensions representing domain-general motor control principles. In a second analysis, we tested the more specific hypotheses that diagnostic parameters split along effector (lip vs. tongue) or functional (speed vs. accuracy) rather than task boundaries. Our findings contradict the view that nonspeech parameters currently used in dysarthria diagnostics are congruent with diagnostic measures of speech characteristics in PWD.

General Motors Optimizes Vehicle Content for Customer Value and Profitability

General Motors (GM) vehicles have more than 100 customer-facing features, known as vehicle content. Decisions about how to package and price these features have a significant impact on our customers’ experiences and on GM’s business results. Vehicle features are assigned as standard, optional, or unavailable on different trim levels, resulting in an enormous combinatorial solution space. Vehicle content optimization (VCO) combines customer market research, discrete choice models, and custom multiobjective nonlinear optimization algorithms to optimize vehicle contenting and pricing decisions. VCO comprehends complex dynamics and tradeoffs and allows GM to optimally balance customer preferences and profitability. After six years of development and multiple proof-of-concept and pilot studies, VCO was officially integrated into GM’s Global Vehicle Development Process in 2014. As of 2021, VCO has been used on more than 85 vehicle programs globally. It has enabled customer-centric product development and more efficient engineering, sourcing, and manufacturing. GM Finance verified that VCO enabled $4.4 billion of incremental profit over the average product life cycle (i.e., six years on average) since 2018, making it a vastly impactful example of operations research and applied analytics.

Cerebellar fastigial nucleus histamine and its H2 but not H1 receptors might inhibit acetic acid-induced visceral nociception and improve motor coordination in rats: role of opioid system.

The cerebellum and its deep nuclei contribute to the regulation of important functions including motor coordination and pain. Histamine modulates some functions of the fastigial nucleus (FN) such as motor coordination. In this study, by application of histamine and activation of its H1 and H2 receptors, the FN processing of visceral pain, general locomotor activity and motor coordination were targeted. The possible mechanism of action was followed by the inhibition of opioid receptors. The right and left sides of the FN were surgically implanted with guide cannulas. Immediately after an intraperitoneal injection of acetic acid (1.00 mL, 1.00%), the first writhing onset latency and the writhing number over 60 min were recorded. Open-field and rotarod tests were applied for general locomotor and motor coordination assessment, respectively. Histamine and dimaprit (H2 receptor agonist) increased first writhing onset latency, decreased the writhing number and increased falling time from the rod. These effects were prevented by ranitidine (H2 receptor antagonist) pre-treatment. Significant alterations were not observed by histamine H1 receptor agonist (2-pyridylethylamine) and antagonist (mepyramine). Naloxone, with no effect on falling time from the rod, inhibited the antinociceptive effects of histamine and dimaprit. Beam break number was not affected by the above-mentioned treatments. Based on the results, it can be suggested that histamine H2, but not H1 receptors at the FN might have had an inhibitory role on acetic acid-induced visceral pain and improved motor coordination. The antinociception, but not motor coordination might be mediated by FN opioid receptors.

Interpretation of the electric vehicle operating point in real time

Abstract In this article, the performance parameters of the electric vehicle were investigated, and its operating point was defined using the core components (Battery, Inverter, and Motor). The test vehicle 2023 Cadillac Lyriq, provided by General Motors Inc., was driven on specified road segments, and the real-time data were retrieved using the integrated controller area network architecture. The neoVI–Fire 2 tool was connected to the vehicle system, which records the dynamic data, and Vehicle Spy software was used to convert the data into a readable format. Finally, the vector electric vehicle operating point was proposed, and the corresponding behavior was interpreted. This methodology could assist researchers in understanding the dynamic behavior of electric vehicle parameters to develop integrated techniques which augment the performance in real time.

Showtime for American Business: General Motors and American Look (1958)

The Chevrolet-General Motors–sponsored film American Look (1958) harnessed technologies of Hollywood spectacle to make their production bigger and bolder than many previous sponsored films. Beyond merely selling a car, the film engaged its viewers with an exhibition of General Motors' corporate persona, aligning its products with the prestige of good design on a grand scale in a Technicolor, widescreen, sponsored epic. Locating my analysis within the cultural and geopolitical context of the Cold War era, this paper argues that American Look expands current rubrics for understanding sponsored and industrial films.

On Improved Commutation for Moving-Magnet Planar Actuators

The demand for high-precision and high-throughput motion control systems has increased significantly in recent years. The use of moving-magnet planar actuators (MMPAs) is gaining popularity due to their advantageous characteristics, such as complete environmental decoupling and reduction of stage mass. Nonetheless, model-based commutation techniques for MMPAs are compromised by misalignment between the mover and coil array and mismatch between the ideal electromagnetic model and the physical system, often leading to decreased system performance. To address this issue, a novel improved commutation approach is proposed in this paper, which is applicable for general planar motor applications, by means of dynamic regulation of the position dependence of the ideal model-based commutation algorithm, which allows for attenuation of magnetic misalignment, manufacturing inaccuracies and other unmodelled phenomena. The effectiveness of the proposed approach is validated through experiments using a state-of-the-art moving-magnet planar actuator prototype.

Underwater and surface tethered swimming, lower limb strength, and somatic traits as the basic indices of young swimmers' sprint performance.

Purpose: The ability to swim fast underwater is believed to be connected to lower limb strength and some somatic traits. The main purpose of the study was to evaluate strength and speed parameters based on the relationship between the strength of underwater dolphin kicks and the countermovement jump test (CMJ) among adolescent swimmers. Methods: 48 adolescent male swimmers (13.47 ± 0.84 years) were examined for muscle mass of arms (m m arms), trunk (m m trunk), and legs (m m legs), body height (BH), and biological age (BA). An underwater tethered dolphin kicking test was conducted in a pool; average force (5F ave) and impulse per single cycle (5I ave) in the 5-second period were measured. Force indices (20F ave - average force from 20 seconds and 20I ave - average impulse per single cycle from 20 seconds) were also measured in 20-second tethered front crawl swimming. During CMJ testing, general lower body muscle motor capabilities were evaluated by extracting the work (CMJw [J]) and height (CMJh [m]) of the jump. Results: The strongest correlations were observed between: (a) 5F ave and BH, m m arms and CMJw; (b) CMJw, m m arms, and 20F ave; (c) indices of swimming speed and 5I ave (BA control); (d) total swimming velocity and average tethered swimming force (BA control). Moderate partial correlations (BA control) were noted between speed indices of swimming race and CMJ. Conclusions: The underwater tethered dolphin kick test is a useful predictor test of 50-m front crawl performance in young male swimmers, with better specificity for swimmers than CMJ results themselves.

The Association of Acute Motor Axonal Neuropathy (Guillain-Barre' Syndrome Variant) with Coronavirus (SARS-Cov-2) in a Child: A Case Report.

Various reports of neurological manifestations of SARS-COV-2 infection after the virus outbreak are available, including anosmia, seizures, acute flaccid myelitis, Guillain-Barré syndrome (GBS), and encephalitis. Most of the literature has focused on the respiratory manifestation of SARS-CoV-2 infection in adults, but recent evidence showed that it is not confined to the respiratory tract. This report is about a rare variant of GBS acute motor axonal neuropathy (AMAN) in a child due to COVID-19 infection An 11 years old boy was referred to the hospital with a history of three-day lasting mild fever, and gastroenteritis, two weeks before starting symptoms. He was presented with progressive ascending weakness, paresthesia, and areflexia in four limbs four days ago. Nasopharyngeal swab polymerase chain reaction (PCR) was positive for SARS-CoV-2. The electrodiagnostic finding was compatible with acute generalized axonal motor neuropathy, and imaging revealed thoracolumbar syrinx and nerve root enhancement in lumbosacral MRI. Other lab tests were normal. GBS and its variant are one of the manifestations of SARS-CoV-2 in children. Children with an unexplained neurological process should be tested for SARS-CoV-2.