Проблемы технического нормирования шумовых характеристик текстильных машин

Для целей оценки соответствия шумовых характеристик машин требованиям санитарных норм предложено использовать обобщенные предельно допустимые шумовые характеристики, которые задают предельно допустимые характеристики для близких по типу машин, объединенных в группы с учетом характерной плотности их установки и условий эксплуатации. Для уточненного определения этих характеристик целесообразно использовать методику, учитывающую звукопоглощение и рассеяние шума поверхностью машин, плотность тел рассеяния в поперечном сечении производственного помещения и его акустические и геометрические характеристики.For the purposes of assessing the compliance of noise characteristics of machines with the requirements of sanitary standards, it is suggested to use generalized maximum permissible noise characteristics that set the maximum permissible characteristics for similar machines, grouped together, taking into account the characteristic density of their installation and operating conditions. For an accurate definition of these characteristics, it is advisable to use a technique that takes into account the sound absorption and noise scattering by the machine surface, the density of scattering bodies in the cross section of the production room and its acoustic and geometric characteristics

Deficits in visuo-spatial working memory, inhibition and oculomotor control in boys with ADHD and their non-affected brothers.

Few studies have assessed visuo-spatial working memory and inhibition in attention-deficit/hyperactivity disorder (ADHD) by recording saccades and consequently little additional knowledge has been gathered on oculomotor functioning in ADHD. Moreover, this is the first study to report the performance of non-affected siblings of children with ADHD, which may shed light on the familiality of deficits. A total of 14 boys with ADHD, 18 non-affected brothers, and 15 control boys aged 7-14 years, were administered a memory-guided saccade task with delays of three and seven seconds. Familial deficits were found in accuracy of visuo-spatial working memory, percentage of anticipatory saccades, and tendency to overshoot saccades relative to controls. These findings suggest memory-guided saccade deficits may relate to a familial predisposition for ADHD

Overweight status and psychological well-being in adolescent boys and girls: a multilevel analysis*

Background: Psychological distress and high body mass index (BMI) are linked in adults, especially in females. Effects of social position and behaviour, and whether obesogenic environments affect adolescents and adults equally are unresolved. The aim was to examine associations between psychological distress and being overweight in adolescents, by sex, accounting for social, lifestyle and contextual factors. Correlation of area-level variation in overweight status in adolescents and adults was investigated. Methods: Height, weight, General Health Questionnaire 12 (GHQ12) of psychological distress, physical activity, smoking, alcohol consumption, area deprivation and social class were available on 635 male and 618 female adolescents (13–15 years) from two cross-sectional population health surveys conducted in Scotland in 1998–99/2003–04. Multilevel logistic regression modelled overweight (including obese) status accounting for intraclass correlation of adolescents in households within postcode sector areas in health board regions. Univariable analysis examined effects of high (4 or more) GHQ12 score; multivariable analysis further allowed for covariates. Adult data were used to assess the importance of correlation between adolescent and adult area-level variation. Results: Univariably, there was significantly increased risk of being overweight associated with high GHQ12 score for girls but not boys; adolescent and adult area-level variation correlation did not impact. Results remained significant for girls in multivariable analyses (OR = 2.44, 95% confidence interval (CI): 1.33–4.50) and non-significant for boys (OR = 1.31, 95% CI: 0.56–3.05). Conclusions: Findings indicate being overweight is associated with psychological distress in adolescent girls, but not boys. Effects are not mediated by social, lifestyle or contextual factors

Effect of dioxins on regulation of tyrosine hydroxylase gene expression by aryl hydrocarbon receptor: a neurotoxicology study

<p>Abstract</p> <p>Background</p> <p>Dioxins and related compounds are suspected of causing neurological disruption. Epidemiological studies indicated that exposure to these compounds caused neurodevelopmental disturbances such as learning disability and attention deficit hyperactivity disorder, which are thought to be closely related to dopaminergic dysfunction. Although the molecular mechanism of their actions has not been fully investigated, a major participant in the process is aryl hydrocarbon receptor (AhR). This study focused on the effect of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) exposure on the regulation of TH, a rate-limiting enzyme of dopamine synthesis, gene expression by AhR.</p> <p>Methods</p> <p>N2a-Rβ cells were established by transfecting murine neuroblastoma Neuro2a with the rat AhR cDNA. TH expression induced by TCDD was assessed by RT-PCR and Western blotting. Participation of AhR in TCDD-induced TH gene expression was confirmed by suppressing AhR expression using the siRNA method. Catecholamines including dopamine were measured by high-performance liquid chromatography. A reporter gene assay was used to identify regulatory motifs in the promoter region of TH gene. Binding of AhR with the regulatory motif was confirmed by an electrophoretic mobility shift assay (EMSA).</p> <p>Results</p> <p>Induction of TH by TCDD through AhR activation was detected at mRNA and protein levels. Induced TH protein was functional and its expression increased dopamine synthesis. The reporter gene assay and EMSA indicated that AhR directly regulated TH gene expression. Regulatory sequence called aryl hydrocarbon receptor responsive element III (AHRE-III) was identified upstream of the TH gene from -285 bp to -167 bp. Under TCDD exposure, an AhR complex was bound to AHRE-III as well as the xenobiotic response element (XRE), though AHRE-III was not identical to XRE, the conventional AhR-binding motif.</p> <p>Conclusion</p> <p>Our results suggest TCDD directly regulate the dopamine system by TH gene transactivation via an AhR-AHRE-III-mediated pathway. The AhR- mediated pathway could have a particular AhR-mediated genomic control pathway transmitting the effects of TCDD action to target cells in the development of dopaminergic disabilities.</p

The influence of methylphenidate on the power spectrum of ADHD children – an MEG study

BACKGROUND: The present study was dedicated to investigate the influence of Methylphenidate (MPH) on cortical processing of children who were diagnosed with different subtypes of Attention Deficit Hyperactivity Disorder (ADHD). As all of the previous studies investigating power differences in different frequency bands have been using EEG, mostly with a relatively small number of electrodes our aim was to obtain new aspects using high density magnetoencephalography (MEG). METHODS: 35 children (6 female, 29 male) participated in this study. Mean age was 11.7 years (± 1.92 years). 17 children were diagnosed of having an Attention-Deficit/Hyperactivity Disorder of the combined type (ADHDcom, DSM IV code 314.01); the other 18 were diagnosed for ADHD of the predominantly inattentive type (ADHDin, DSM IV code 314.0). We measured the MEG during a 5 minute resting period with a 148-channel magnetometer system (MAGNES™ 2500 WH, 4D Neuroimaging, San Diego, USA). Power values were averaged for 5 bands: Delta (D, 1.5–3.5 Hz), Theta (T, 3.5–7.5 Hz), Alpha (A, 7.5–12.5 Hz), Beta (B, 12.5–25 Hz) and Global (GL, 1.5–25 Hz).). Additionally, attention was measured behaviourally using the D2 test of attention with and without medication. RESULTS: The global power of the frequency band from 1.5 to 25 Hz increased with MPH. Relative Theta was found to be higher in the left hemisphere after administration of MPH than before. A positive correlation was found between D2 test improvement and MPH-induced power changes in the Theta band over the left frontal region. A linear regression was computed and confirmed that the larger the improvement in D2 test performance, the larger the increase in Theta after MPH application. CONCLUSION: Main effects induced by medication were found in frontal regions. Theta band activity increased over the left hemisphere after MPH application. This finding contradicts EEG results of several groups who found lower levels of Theta power after MPH application. As relative Theta correlates with D2 test improvement we conclude that MEG provide complementary and therefore important new insights to ADHD

Childhood obesity, prevalence and prevention

Childhood obesity has reached epidemic levels in developed countries. Twenty five percent of children in the US are overweight and 11% are obese. Overweight and obesity in childhood are known to have significant impact on both physical and psychological health. The mechanism of obesity development is not fully understood and it is believed to be a disorder with multiple causes. Environmental factors, lifestyle preferences, and cultural environment play pivotal roles in the rising prevalence of obesity worldwide. In general, overweight and obesity are assumed to be the results of an increase in caloric and fat intake. On the other hand, there are supporting evidence that excessive sugar intake by soft drink, increased portion size, and steady decline in physical activity have been playing major roles in the rising rates of obesity all around the world. Consequently, both over-consumption of calories and reduced physical activity are involved in childhood obesity. Almost all researchers agree that prevention could be the key strategy for controlling the current epidemic of obesity. Prevention may include primary prevention of overweight or obesity, secondary prevention or prevention of weight regains following weight loss, and avoidance of more weight increase in obese persons unable to lose weight. Until now, most approaches have focused on changing the behaviour of individuals in diet and exercise. It seems, however, that these strategies have had little impact on the growing increase of the obesity epidemic. While about 50% of the adults are overweight and obese in many countries, it is difficult to reduce excessive weight once it becomes established. Children should therefore be considered the priority population for intervention strategies. Prevention may be achieved through a variety of interventions targeting built environment, physical activity, and diet. Some of these potential strategies for intervention in children can be implemented by targeting preschool institutions, schools or after-school care services as natural setting for influencing the diet and physical activity. All in all, there is an urgent need to initiate prevention and treatment of obesity in children

PET and SPECT imaging in ADHD

ADHD is a clinically heterogeneous neuropsychiatric disorder with a childhood onset and is often accompanied by comorbidities. Symptoms consisting of inattention with or without hyperactivity or impulsivity may result from disturbances of higher cognitive control, involving multiple regions of the brain which are functionally connected. Although the value of PET and SPECT in establishing diagnosis is limited, it has added to understanding the neurobiological basis of ADHD. Investigations of cerebral perfusion and glucose metabolism during resting conditions and specific tasks have led ADHD to be associated with reduced functionality of the prefrontal cortex and the anterior cingulate cortex, as well as the basal ganglia, cerebellum and parietal lobe. In addition, there is a growing body of literature assessing the dopamine transporter, endogenous levels of dopamine, response to treatment with methylphenidate and the relationship with genotypes in ADHD with few studies having assessed serotonergic and noradrenergic functioning.</p