New Global Referencing Approach in a Camera-LCD Micro Positioning System.

In any precision manufacturing process, positioning systems play a very important role in achieving a quality product. As a new approach to current systems, camera-LCD positioning systems are a new technology that can provide substantial improvements enabling better accuracy and repeatability. However, in order to provide stability to the system a global positioning system is required. This paper presents an improvement of a positioning system based on the treatment of images on an LCD in which a new algorithm with absolute reference has been implemented. The method is based on basic geometry and linear algebra applied to computer vision. The algorithm determines the spiral center using an image taken at any point. Consequently, the system constantly knows its position and does not lose its reference. Several modifications of the algorithm are proposed and compared. The simulation and test of the algorithm provide an important improvement in the reliability and stability of the positioning system providing errors of microns for the calculation of the global position used by the algorithm.

Description of frail older people profiles according to four screening tools applied in primary care settings: a cross sectional analysis.

BACKGROUND: Regarding the health care of older populations, WHO recommends shifting from disease-driven attention models towards a personalized, integrated and continuous care aimed to the maintenance and enhancement of functional capacities. Impairments in the construct of functional intrinsic capacity have been understood as the condition of frailty or vulnerability. No consensus has been yet reached regarding which tools are the most suitable for screening this kind of patients in primary care settings. Tools based on the measurement of functional performance such as Timed up and go test (TUG), Short Physical Performance battery (SPPB), self-completed questionnaires like Tilburg Frailty Indicator (TFI) and clinical judgement, as the Gerontopole Frailty Scale (GFS) may be adequate. The objective of this work is to describe and compare characteristics of community-dwelling individuals identified as vulnerable or frail by four tools applied in primary care settings. METHODS: Cross sectional analysis developed in primary care services in two regions of Spain. Community-dwelling independent individuals aged 70 or more willing to participate were recruited and data was collected via face-to-face interviews. Frailty was assessed by TUG, SPPB, TFI and GFST. Also socio-demographic characteristics, lifestyle habits and health status data (comorbidities, polypharmacy, self-perceived health), were collected. Multiple correspondence analysis (MCA) and cluster analysis were used to identify groups of individuals with similar characteristics. RESULTS: Eight hundred sixty-five individuals were recruited, 53% women, with a mean age of 78 years. Four clusters of participants emerge. Cluster 1 (N = 263) contained patients categorized as robust by most of the studied tools, whereas clusters 2 (N = 199), 3 (N = 183) and 4 (N = 220) grouped patients classified as frail or vulnerable by at least one of the tools. Significant differences were found between clusters. CONCLUSIONS: The assessed tools identify different profiles of patients according to their theoretical construct of frailty. There is a group of patients that are identified by TUG and SPPB but not by GFS or TFI. These tools may be useful in primary care settings for the implementation of a function- driven clinical care of older patients.

Reversible NO2 Optical Fiber Chemical Sensor Based on LuPc2 Using Simultaneous Transmission of UV and Visible Light.

In this paper, an NO2 optical fiber sensor is presented for pollution monitoring in road traffic applications. This sensor exploits the simultaneous transmission of visible light, as a measurement signal, and UV light, for the recovery of the NO2 sensitive materials. The sensor is based on a multimode fiber tip coated with a thin film of lutetium bisphthalocyanine (LuPc2). The simultaneous injection of UV light through the fiber is an improvement on the previously developed NO2 sensors and allows the simplification of the sensor head, rendering the external UV illumination of the film unnecessary. Coatings of different thicknesses were deposited on the optical fiber tips and the best performance was obtained for a 15 nm deposited thickness, with a sensitivity of 5.02 mV/ppm and a resolution of 0.2 ppb in the range 0-5 ppm. The response and recovery times are not dependent on thickness, meaning that NO2 does not diffuse completely in the films.

[The social catholic doctrine in the industrializing process of Francoist Spain: the case of the Alter pharmaceutical group]. / La doctrina social católica en el proceso industrializador de la España franquista: el caso del grupo farmacéutico Alter.

Alter Laboratories and the group of companies developed by Juan José Alonso Grijalba (1894-1962) under Franco's regime held the Catholic social doctrine as the foundation of his business. This pharmacist was a strong advocate and propagandist of these ideas. In this paper, we outline the biography of this entrepreneur, describe his ideological principles, and analyze how these theories were implemented in the Alter Laboratories in their economic, cultural-recreational, and moral-religious dimensions. The business approach revealed by the writings of Juan José Alonso is a "patriarchal patronage"; his goal appears to have been the conversion of Alter into a "factory convent" with the programmatic foundations of Catholic humanism, in which the employer assumes a clearly despotic role and the intervention of workers is reduced to accepting the standards and perks offered by the employer.

Cognitive-emotional hyperarousal in the offspring of parents vulnerable to insomnia: a nuclear family study.

Cognitive-emotional hyperarousal is believed to be a predisposing factor for insomnia; however, there is limited information on the association of familial vulnerability to insomnia and cognitive-emotional hyperarousal. The aim of this study was to estimate the heritability of stress-related insomnia and examine whether parental vulnerability to stress-related insomnia is associated with cognitive-emotional hyperarousal in their offspring. We studied a volunteer sample of 135 nuclear families comprised of 270 middle-aged (51.5 ± 5.4 years) fathers and mothers and one of their biological offspring (n = 135, 20.2 ± 1.1 years). We measured vulnerability to stress-related insomnia (i.e. Ford Insomnia Response to Stress Test: FIRST), perceived stress, depression and anxiety in all participants, and arousability, presleep cognitive and somatic arousal, coping and personality in the offspring. We found a heritability estimate of 29% for FIRST scores. High FIRST parents had three to seven times the odds of having offspring highly vulnerable to stress-related insomnia. Offspring of high FIRST parents showed higher arousability, presleep cognitive arousal and emotion-oriented coping. Furthermore, high FIRST mothers contributed to offspring's higher anxiety and lower task-oriented coping, while high FIRST fathers contributed to offspring's higher presleep somatic arousal and conscientiousness. Vulnerability to stress-related insomnia is significantly heritable. Parents vulnerable to stress-related insomnia have offspring with cognitive-emotional hyperarousal who rely upon emotion-oriented coping. These data give support to the notion that arousability and maladaptive coping are key factors in the aetiology of insomnia.

Fast thermal regeneration of fiber Bragg gratings.

In this Letter we report a fast thermal regeneration of Type I fiber Bragg gratings inscribed with a UV laser in up to four different optical fibers: hydrogenated standard fiber, hydrogenated highly Ge-doped fiber, hydrogenated photosensitive fiber, and nonhydrogenated fiber. The thermal treatment consists in directly introducing the optical fiber into a preheated oven. The preheat temperature depends on the type of fiber used and is high enough to erase the grating and regenerate it afterward. The best results are obtained with hydrogenated photosensitive fiber and highly Ge-doped fiber, whereas no satisfactory results were obtained with hydrogenated standard fiber and nonhydrogenated photosensitive fiber. A regenerated grating with only 1.6 dB of loss was obtained in 10 min, reducing the time needed by a factor of 5.7. By adjusting the temperature of the oven, regenerated gratings of 13.7 dB of loss in 31 s and 5.8 dB of loss in 3 min were obtained. The factors of improvement in time are 110.3 and 19, respectively.

Sleep quality and sleep deprivation: relationship with academic performance in university students during examination period.

The beginning of the university brings together maturational, psychosocial and academic changes that make university students more prone to suffer from insufficient or poor quality sleep, which can negatively influence their academic performance. The period of taking exams is a key part of the academic year. However, there are few studies that analyze sleep during this period of time. Our aim is to study the association of sleep quality and sleep deprivation with academic performance during the examination period. A descriptive, cross-sectional and correlational study was carried out with the participation of 640 subjects in the first three years of five faculties belonging to the Universidad Autónoma de Madrid. The instrument used consisted of a questionnaire that included sociodemographic and academic data, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and information about the academic performance. During the examination period, a positive association was found between sleep quality and academic performance. University students slept less than desired, both on weekdays and weekends, and the sleep debt during the week was associated with a worse students' perception of their academic performance. In total, 61.3% of the students believed that their performance would improve by getting more sleep. In addition, low drowsiness and napping were also found. In conclusion, during periods of greater academic demand, an insufficient sleep and poor quality is commonly observed, affecting negatively to their academic performance. Actually, about 2/3 of our subjects believed that their performance would improve by getting more sleep.

Effects of an Optimized Aged Garlic Extract on Cardiovascular Disease Risk Factors in Moderate Hypercholesterolemic Subjects: A Randomized, Crossover, Double-Blind, Sustainedand Controlled Study.

The consumption of aged black garlic (ABG) has been related to improvements in several cardiovascular disease (CVD) risk factors. However, the extent of the beneficial effects depends on the garlic aging process and the amount and type of chemical compounds accumulated. The main objective of this study was to assess the effect of daily intake of a well-characterized ABG extract with a standardized S-allyl-L-cysteine (SAC) yield in combination with dietary recommendations regarding CVD risk factors in individuals with moderate hypercholesterolemia. Sixty-seven hypercholesterolemic individuals with low-density lipoprotein cholesterol levels ≥115 mg/dL were randomized in a crossover, double-blind, sustained, and controlled intervention study. The participants consumed 250 mg (1.25 mg SAC)/tablet/day ABG or a placebo for 6 weeks, with 3 weeks of washout. Blood and pulse pressure and other CVD risk biomarkers were determined at the beginning and end of each intervention. At 6 weeks, ABG extract reduced diastolic blood pressure (DBP) (mean (95% CI) −5.85 (−10.5; −1.3) mm Hg) compared to the placebo, particularly in men with a DBP > 75 mm Hg. The consumption of an improved ABG extract with 1.25 mg of SAC decreased DBP, particularly in men with moderate hypercholesterolemia. The potential beneficial effects of ABG may contribute to obtaining an optimal DBP.

Sleep misperception and chronic insomnia in the general population: role of objective sleep duration and psychological profiles.

OBJECTIVE: To examine the role of objective sleep duration, a novel marker in phenotyping insomnia, and psychological profiles on sleep misperception in a large, general population sample. Sleep misperception is considered by some investigators a common characteristic of chronic insomnia, whereas others propose it as a separate diagnosis. The frequency and the determinants of sleep misperception in general population samples are unknown. METHODS: A total of 142 insomniacs and 724 controls selected from a general random sample of 1,741 individuals (aged ≥20 years) underwent a polysomnographic evaluation, completed the Minnesota Multiphasic Personality Inventory-2, and were split into two groups based on their objective sleep duration: "normal sleep duration" (≥6 hours) and "short sleep duration" (<6 hours). RESULTS: The discrepancy between subjective and objective sleep duration was determined by two independent factors. Short sleepers reported more sleep than they objectively had, and insomniacs reported less sleep than controls with similar objective sleep duration. The additive effect of these two factors resulted in underestimation only in insomniacs with normal sleep duration. Insomniacs with normal sleep duration showed a Minnesota Multiphasic Personality Inventory-2 profile of high depression and anxiety and low ego strength, whereas insomniacs with short sleep duration showed a profile of a medical disorder. CONCLUSIONS: Underestimation of sleep duration is prevalent among insomniacs with objective normal sleep duration. Anxious-ruminative traits and poor resources for coping with stress seem to mediate the underestimation of sleep duration. These data further support the validity and clinical utility of objective sleep measures in phenotyping insomnia.

Effects of Obligate Heterofermentative Lactic Acid Bacteria Alone or in Combination on the Conservation of Sugarcane Silage.

Our objective was to determine the effects of two strains of obligate heterofermentative bacteria, alone or in combination, on the fermentation profile, gas production kinetics, chemical composition, and aerobic stability of sugarcane silage. A plot of sugarcane was manually harvested, mechanically chopped and treated with: distilled water (5 mL kg-1; Control), Lentilactobacillus hilgardii CNCM I-4785 [3 × 105 colony-forming units (cfu) g-1; LH], Lentilactobacillus buchneri NCIMB 40788 (3 × 105 cfu g-1; LB), and LH+LB (1.5 × 105 cfu g-1 of each strain). Treated forages were packed into 1.96-L gas-tight silos (0.40 porosity) and stored at 25 ± 1.5°C for 70 days (4 replicates per treatment). All heterolactic inoculants were effective to increase acetic acid concentration and inhibit yeast metabolism, as treated silages had lower formation of ethanol, ethyl esters and gas during fermentation. Lower fungal development spared soluble carbohydrates, consequently resulting in silages with higher in vitro digestibility. Nevertheless, L. buchneri was the most effective strain to extend the aerobic stability of sugarcane silage (based on both temperature and pH rise). The use of L. buchneri alone or in combination with L. hilgardii, applied at 3 × 105 cfu g-1, is a feasible strategy to inhibit yeast metabolism and increase the nutritional quality of sugarcane silage.

Effects of protein source and lipid supplementation on conservation and feed value of total mixed ration silages for finishing beef cattle.

The objective of this study was to examine the conservation process and feed value of total mixed ration (TMR) silages. In exp. 1, we evaluated the fermentation pattern and aerobic stability of TMR silages containing different protein and lipid supplementations. In exp. 2, we compared the performance of finishing beef heifers fed those TMR silages. In both experiments, treatments were as follows: ensiled TMR with urea (U); ensiled TMR without a protein supplement at ensiling, but soybean meal supplemented at feeding to balance diet crude protein (CP) in exp. 2 (SMnf; where the acronym nf indicates nonfermented); ensiled TMR with soybean meal (SM); and ensiled TMR with rolled soybean grain (SG). Thirty-two Nellore heifers (313 ± 8.8 kg shrunk body weight [SBW]) were blocked by initial SBW, housed in individual pens, and enrolled in exp. 2 for 82 d. In exp. 1, treatment without a protein supplement (SMnf) had a lower content of CP, soluble CP, NH3-N, pH, and Clostridium count compared with U (P ≤ 0.03). Lactic acid concentrations tended to be reduced for SMnf compared with U (P = 0.09). Ethanol concentration was reduced in SG compared with SM (P < 0.01). 1,2-Propanediol concentration was increased in SMnf compared with U (P < 0.01), reduced in SM compared with SMnf (P = 0.02), and increased in SG compared with SM (P = 0.02). Dry matter (DM) loss during fermentation was low and similar among treatments (~3.7%). All silages remained stable during 10 d of aerobic exposure after feed out. Considering fermentation traits, such as pH (≤4.72), NH3-N (<10% of N, except for U treatment), butyric acid (<0.05 % DM), and DM losses (<3.70% DM), all silages can be considered well conserved. In exp. 2, diets were isonitrogenous because soybean meal was added to SMnf before feeding. Compared with SM, cattle fed SG made more meals per day (P = 0.04) and tended to have a decreased intermeal interval (P = 0.09). DM intake, average daily gain, final SBW, hot carcass weight, Biceps femoris fat thickness, and serum levels of triglycerides and cholesterol were increased for SG compared with SM (P ≤ 0.05). In brief, TMR silages exhibited an adequate fermentation pattern and high aerobic stability. The supplementation of true protein did not improve animal performance, whereas the addition of soybean grain as a lipid source improved the performance of finishing cattle fed TMR silages.

Insomnia with objective short sleep duration is associated with deficits in neuropsychological performance: a general population study.

STUDY OBJECTIVES: To examine the joint effect of insomnia and objective short sleep duration on neuropsychological performance. DESIGN: Representative cross-sectional study. SETTING: Sleep laboratory. PARTICIPANTS: 1,741 men and women randomly selected from central Pennsylvania. INTERVENTIONS: None. MEASUREMENTS: Insomnia (n = 116) was defined by a complaint of insomnia with a duration > or = 1 year and the absence of sleep disordered breathing (SDB), while normal sleep (n = 562) was defined as the absence of insomnia, excessive daytime sleepiness, and SDB. Both groups were split according to polysomnographic sleep duration into 2 categories: > or = 6 h of sleep ("normal sleep duration") and < 6 h of sleep ("short sleep duration"). We compared the groups' performance on a comprehensive neuropsychological battery that measured processing speed, attention, visual memory, and verbal fluency, while controlling for age, race, gender, education, body mass index, and physical and mental health. RESULTS: No significant differences were detected between insomniacs and controls. However, the insomnia with short sleep duration group compared to the control with normal or short sleep duration groups showed poorer neuropsychological performance in variables such as processing speed, set-switching attention, and number of visual memory errors and omissions. In contrast, the insomnia with normal sleep duration group showed no significant deficits. CONCLUSIONS: Insomnia with objective short sleep duration is associated with deficits in set-switching attentional abilities, a key component of the "executive control of attention." These findings suggest that objective sleep duration may predict the severity of chronic insomnia, including its effect on neurocognitive function.

Cognitive-emotional hyperarousal as a premorbid characteristic of individuals vulnerable to insomnia.

OBJECTIVE: To examine whether cognitive-emotional hyperarousal is a premorbid characteristic of middle-aged and young good sleepers vulnerable to stress-related insomnia. METHODS: Self-reported information was collected from two samples of 305 middle-aged and 196 young adults. From those adults, 149 middle-aged (50.34 +/- 4.47 years) and 85 young (20.19 +/- 1.31 years) good sleepers were selected for the present study. The Ford Insomnia Response to Stress Test (FIRST) was used to measure vulnerability to stress-related insomnia. Trait measures of personality, arousability, rumination, presleep arousal, and coping skills were entered as predictors in the linear regression models, at the same time controlling for gender, depression, and anxiety. RESULTS: The regression models showed that arousability (beta = 0.546), neuroticism (beta = 0.413), perceived stress (beta = 0.375), and rumination (beta = 0.214) were associated with FIRST scores in middle-aged adults. Among young adults, the regression models revealed that presleep cognitive arousal (beta = 0.448), arousability (beta = 0.426), neuroticism (beta = 0.320), presleep somatic arousal (beta = 0.290), emotion-oriented coping (beta = 0.220), and rumination (beta = 0.212) were associated with FIRST scores. Finally, individuals with high FIRST scores did not show lower scores in measures of cognitive-emotional hyperarousal compared with chronic insomniacs. CONCLUSIONS: These data suggest that cognitive-emotional hyperarousal may be a premorbid characteristic of subjects vulnerable to insomnia. It seems that maladaptive coping stress strategies and cognitive-emotional hyperarousal predispose to the development of insomnia and that interventions targeting these characteristics may be important in the prevention and treatment of chronic insomnia.

Effects of processing, moisture, and storage length on the fermentation profile, particle size, and ruminal disappearance of reconstituted corn grain.

Our objective was to examine the effects of processing, moisture, and anaerobic storage length of reconstituted corn grain (RCG) on the fermentation profile, geometric mean particle size (GMPS), and ruminal dry matter disappearance (DMD). Dry corn kernels were ground (hammer mill, 5-mm screen) or rolled, then rehydrated to 30%, 35%, or 40% moisture, and stored for 0, 14, 30, 60, 90, 120, or 180 d in laboratory silos. Rolled corn had an increased GMPS compared with ground corn (2.24 and 1.13 mm, respectively, at ensiling). However, there was a trend for an interaction between processing and moisture concentration to affect particle size, with GMPS increasing with increased moisture concentration, especially in ground corn. Longer storage periods also slightly increased GMPS. Processing, moisture, and storage length interacted to affect the fermentation pattern (two- or three-way interactions). Overall, pH decreased, whereas lactic acid, acetic acid, ethanol, and NH3-N increased with storage length. RCG with 30% moisture had less lactic acid than corn with 35% and 40% moisture, indicating that fermentation might have been curtailed and also due to the clostridial fermentation that converts lactic acid to butyric acid. Ensiling reconstituted ground corn with 30% of moisture led to greater concentrations of ethanol and butyric acid, resulting in greater DM loss than grain rehydrated to 35% or 40% of moisture. Ammonia-N and in situ ruminal DMD were highest for reconstituted ground corn with 35% or 40% of moisture, mainly after 60 d of storage. Therefore, longer storage periods and greater moisture contents did not offset the negative effect of greater particle size on the in situ ruminal DMD of rolled RCG. Nonetheless, RCG should be ensiled with more than 30% moisture and stored for at least 2 mo to improve the ruminal DMD and reduce the formation of ethanol and butyric acid.

Antibacterial and antifungal activity of crude and freeze-dried bacteriocin-like inhibitory substance produced by Pediococcus pentosaceus.

Pediococcus pentosaceus LBM 18 has shown potential as producer of an antibacterial and antifungal bacteriocin-like inhibitory substance (BLIS). BLIS inhibited the growth of spoilage bacteria belonging to Lactobacillus, Enterococcus and Listeria genera with higher activity than Nisaplin used as control. It gave rise to inhibition halos with diameters from 9.70 to 20.00 mm, with Lactobacillus sakei being the most sensitive strain (13.50-20.00 mm). It also effectively suppressed the growth of fungi isolated from corn grain silage for up to 25 days and impaired morphology of colonies by likely affecting fungal membranes. These results point out that P. pentosaceus BLIS may be used as a new promising alternative to conventional antibacterial and antifungal substances, with potential applications in agriculture and food industry as a natural bio-controlling agent. Moreover, cytotoxicity and cell death induction tests demonstrated cytotoxicity and toxicity of BLIS to human colon adenocarcinoma Caco-2cells but not to peripheral blood mononuclear cells, with suggests possible applications of BLIS also in medical-pharmaceutical applications.

Insomnia with objective short sleep duration is associated with a high risk for hypertension.

STUDY OBJECTIVES: To examine the joint effect of insomnia and objective short sleep duration on hypertension risk. DESIGN: Representative cross-sectional study. SETTING: Sleep laboratory. PARTICIPANTS: 1,741 men and women randomly selected from central Pennsylvania. INTERVENTIONS: None. MEASUREMENTS: Insomnia was defined by a complaint of insomnia with a duration > or = 1 year, while poor sleep was defined as a complaint of difficulty falling asleep, staying asleep, or early final awakening. Polysomnographic sleep duration was classified into 3 categories: > or = 6 h sleep (top 50% of the sample); 5-6 h (approximately the third quartile of the sample); and < or = 5 h (approximately the bottom quartile of the sample). Hypertension was defined based either on blood pressure measures or treatment. We controlled for age, race, sex, body mass index, diabetes, smoking, alcohol use, depression, sleep disordered breathing (SDB), and sampling weight. RESULTS: Compared to the normal sleeping and > 6 h sleep duration group, the highest risk of hypertension was in insomnia with < 5 h sleep duration group (OR [95% CI] 5.1 [2.2, 11.8]), and the second highest in insomnia who slept 5-6 hours (OR 3.5 [1.6, 7.9] P < 0.01). The risk for hypertension was significantly higher, but of lesser magnitude, in poor sleepers with short sleep duration. CONCLUSIONS: Insomnia with short sleep duration is associated with increased risk of hypertension, to a degree comparable to that of other common sleep disorders, e.g., SDB. Objective sleep duration may predict the severity of chronic insomnia a prevalent condition whose medical impact has been apparently underestimated.

Evidence of subthalamic PGO-like waves during REM sleep in humans: a deep brain polysomnographic study.

STUDY OBJECTIVES: The aim of this study was to examine whether the subthalamic nucleus (STN) plays a role in the transmission of PGO-like waves during REM sleep in humans. DESIGN: Simultaneous recordings from deep brain electrodes to record local field potentials (LFPs), and standard polysomnography to ascertain sleep/wake states. SETTING: Main Hospital, department of clinical neurophysiology sleep laboratory. PARTICIPANTS: 12 individuals with Parkinson's disease, with electrodes implanted in the STN; and, as a control for localization purposes, 4 cluster headache patients with electrodes implanted in the posterior hypothalamus. INTERVENTIONS: All subjects underwent functional neurosurgery for implantation of deep brain stimulation electrodes. RESULTS: Sharp, polarity-reversed LFPs were recorded within the STN during REM sleep in humans. These subthalamic PGO-like waves (2-3 Hz, 80-200 pV, and 300-500 msec) appeared during REM epochs as singlets or in clusters of 3-13 waves. During the pre-REM period, subthalamic PGO-like waves were temporally related to drops in the submental electromyogram and/or onset of muscular atonia. Clusters of PGO-like waves occurred typically before and during the bursts of rapid eye movements and were associated with an enhancement in fast (15-35 Hz) subthalamic oscillatory activity. CONCLUSION: Subthalamic PGO-like waves can be recorded during pre-REM and REM sleep in humans. Our data suggest that the STN may play an active role in an ascending activating network implicated in the transmission of PGO waves during REM sleep in humans.

Sleep disordered breathing in children in a general population sample: prevalence and risk factors.

STUDY OBJECTIVES: Assess the prevalence based on clinically meaningful criteria (i.e., blood pressure) and identify risk factors of sleep disordered breathing (SDB) in a representative sample of elementary school children. DESIGN: A random sample of the local elementary school children (K-5) were assessed using a two-phased strategy. In phase I a brief questionnaire was completed by a parent of each child in local elementary schools (N = 5,740), with a response rate of 78.5%. In phase II, randomly selected children and their parent spent a night in our sleep laboratory (N = 700) with a response rate of 70.0%. SETTING: University sleep laboratory. PARTICIPANTS: Children enrolled in local elementary schools. INTERVENTION: None. MEASUREMENT & RESULTS: Each child was assessed with a full polysomnogram and completed a history/physical examination including an electrocardiogram, otolaryngology examination, and pulmonary evaluation. The prevalence of moderate SDB (apnea-hypopnea index > or = 5) was 1.2%. The independent risk factors included nasal abnormalities and minority associated only with mild (1 < AHI < 5) SDB and snoring and waist circumference associated with all levels of SDB. Tonsil size, based on visual inspection, was not an independent risk factor. CONCLUSION: The prevalence of AHI > or = 5 was 1.2% in a representative sample of elementary school children. Risk factors for SDB included waist circumference, nasal abnormalities (e.g., chronic sinusitis/rhinitis), and minority. The strong linear relationship between waist circumference and BMI across all degrees of severity of SDB suggests that, as in adults, metabolic factors may be among the most important risk factors for SDB in children.

Women sleep objectively better than men and the sleep of young women is more resilient to external stressors: effects of age and menopause.

The aims of this study were to: (i) assess gender differences of objective sleep patterns in a general population sample; (ii) evaluate the effects of menopause and hormone treatment (HT) on the sleep of the same cohort; and (iii) examine gender differences in sleep resilience towards external stressors. The participants were (i) 1324 subjects without sleep complaints, recruited from the general population of Central Pennsylvania that spent one night in the sleep laboratory and (ii) 66 young, healthy volunteers whose sleep was disturbed during night four by an external stressor, i.e. 24-h blood drawing (average of nights 2 and 3 versus night 4). Women compared with men in the general population sample had significantly higher percentage of sleep time, lower percentage of stage 1, and higher percentage of slow wave sleep. Also, menopause, in the absence of HT, was associated with prolonged sleep latency and decreased deep sleep. Finally, young, healthy women compared with men experienced less sleep disturbance because of blood draws as indicated by a significantly smaller change in per cent sleep time, and percentage of stage 1 sleep. These findings suggest that women without sleep complaints sleep objectively better across age than men and the sleep of young women is more resistant to external stressors. Also, gonadal hormones exert a beneficial effect on women's sleep. This gender dimorphism in sleep regulation may have been to protect women from the demands of infant and child care, and in part, might contribute to women's lower cardiovascular risks and greater longevity.