Cortical arousal from sleep is associated with autonomic activation and acute increases in heart rate. Arousals vary considerably in their frequency, intensity/duration, and physiological effects. ...Sleep and arousability impact health acutely (daytime cognitive function) and long-term (cardiovascular outcomes). Yet factors that modify the arousal intensity and autonomic activity remain enigmatic. In this study of healthy human adults, we examined whether reflex airway defense mechanisms, specifically swallowing or glottic adduction, influenced cardiac autonomic activity and cortical arousal from sleep. We found, in all subjects, that swallows trigger rapid, robust, and patterned tachycardia conserved across wake, sleep, and arousal states. Tachycardia onset was temporally matched to glottic adduction—the first phase of swallow motor program. Multiple swallows increase the magnitude of tachycardia via temporal summation, and blood pressure increases as a function of the degree of tachycardia. During sleep, swallows were overwhelmingly associated with arousal. Critically, swallows were causally linked to the intense, prolonged cortical arousals and marked tachycardia. Arousal duration and tachycardia increased in parallel as a function of swallow incidence. Our findings suggest that cortical feedback and tachycardia are integrated responses of the swallowmotor program. Our work highlights the functional influence of episodic, involuntary airway defense reflexes on sleep and vigilance and cardiovascular function in healthy individuals.
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Few studies have examined the influence of a low level of schooling on age-related cognitive decline in countries with wide social and economic inequalities by using the Cambridge Automated ...Neuropsychological Test Battery (CANTAB). The aim of the present study was to assess the influence of schooling on age-related cognitive decline using unbiased cognitive tests. CANTAB allows cognitive assessment across cultures and education levels with reduced interference of the examiner during data acquisition. Using two-way ANOVA, we assessed the influences of age and education on test scores of old adults (61-84 years of age). CANTAB tests included: Visual Sustained Attention, Reaction Time, Spatial Working Memory, Learning and Episodic Memory. All subjects had a minimum visual acuity of 20/30 (Snellen Test), no previous or current history of traumatic brain/head trauma, stroke, language impairment, chronic alcoholism, neurological diseases, memory problems or depressive symptoms, and normal scores on the Mini Mental State Examination (MMSE). Subjects were grouped according to education level (1 to 7 and ≥8 years of schooling) and age (60-69 and ≥70 years). Low schooling level was associated with significantly lower performance on visual sustained attention, learning and episodic memory, reaction time, and spatial working memory. Although reaction time was influenced by age, no significant results on post hoc analysis were detected. Our findings showed a significantly worse cognitive performance in volunteers with lower levels of schooling and suggested that formal education in early life must be included in the preventive public health agenda. In addition, we suggest that CANTAB may be useful to detect subtle cognitive changes in healthy aging.
The Romanian Population by Gender and Age Groups in 2011. Following the previous studies on the demographic characteristics of the Romanian population, ethnicity and religion, this study covers the ...geodemographic issues of gender and age groups. As compared to the previous studies, our analysis covers these major population features in strong connection with the numerical evolution of the population, strongly determined by the socioeconomic background before 1990 and afterwards. We used the official data of the census in 2011 provided by the National Institute of Statistics. In order to create a representative picture of the Romanian population by gender and age groups, we employed the data illustrating the state of these two indicators in tables and maps. As compared to the values registered in 1992, the Romanian population in 2011 registered a decrease of 11.79%, relatively balanced in terms of gender structure, the male population holding a share of 48.65% and the female population, a share of 51.35%. The age structure also reveals a relative balance between active adult population (56.32%) and the young and old population, together holding a share of 43.68%. Spatially, the structure of the Romanian population by gender and age structure, show differences at county level and also at a larger scale.
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The Romanian Population by Gender and Age Groups in 2011. Following the previous studies on the demographic characteristics of the Romanian population, ethnicity and religion, this study covers the ...geodemographic issues of gender and age groups. As compared to the previous studies, our analysis covers these major population features in strong connection with the numerical evolution of the population, strongly determined by the socioeconomic background before 1990 and afterwards. We used the official data of the census in 2011 provided by the National Institute of Statistics. In order to create a representative picture of the Romanian population by gender and age groups, we employed the data illustrating the state of these two indicators in tables and maps. As compared to the values registered in 1992, the Romanian population in 2011 registered a decrease of 11.79%, relatively balanced in terms of gender structure, the male population holding a share of 48.65% and the female population, a share of 51.35%. The age structure also reveals a relative balance between active adult population (56.32%) and the young and old population, together holding a share of 43.68%. Spatially, the structure of the Romanian population by gender and age structure, show differences at county level and also at a larger scale.
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During supramaximal exercise, exacerbated at exhaustion and in hypoxia, the circulatory system is challenged to facilitate oxygen delivery to working tissues through cerebral autoregulation which ...influences fatigue development and muscle performance. The aim of the study was to evaluate the effects of different levels of normobaric hypoxia on the changes in peripheral and cerebral oxygenation and performance during repeated sprints to exhaustion. Eleven recreationally active participants (six men and five women; 26.7 ± 4.2 years, 68.0 ± 14.0 kg, 172 ± 12 cm, 14.1 ± 4.7% body fat) completed three randomized testing visits in conditions of simulated altitude near sea-level (~380 m, F
O
20.9%), ~2000 m (F
O
16.5 ± 0.4%), and ~3800 m (F
O
13.3 ± 0.4%). Each session began with a 12-min warm-up followed by two 10-s sprints and the repeated cycling sprint (10-s sprint: 20-s recovery) test to exhaustion. Measurements included power output, vastus lateralis, and prefrontal deoxygenation near-infrared spectroscopy, delta (Δ) corresponds to the difference between maximal and minimal values, oxygen uptake, femoral artery blood flow (Doppler ultrasound), hemodynamic variables (transthoracic impedance), blood lactate concentration, and rating of perceived exertion. Performance (total work, kJ; -27.1 ± 25.8% at 2000 m,
< 0.01 and -49.4 ± 19.3% at 3800 m,
< 0.001) and pulse oxygen saturation (-7.5 ± 6.0%,
< 0.05 and -18.4 ± 5.3%,
< 0.001, respectively) decreased with hypoxia, when compared to 400 m. Muscle Δ hemoglobin difference (Hbdiff) and Δ tissue saturation index (TSI) were lower (
< 0.01) at 3800 m than at 2000 and 400 m, and lower Δ deoxyhemoglobin resulted at 3800 m compared with 2000 m. There were reduced changes in peripheral ΔHbdiff, ΔTSI, Δ total hemoglobin (tHb) and greater changes in cerebral (ΔHbdiff, ΔtHb) oxygenation throughout the test to exhaustion (
< 0.05). Changes in cerebral deoxygenation were greater at 3800 m than at 2000 and 400 m (
< 0.01). This study confirms that performance in hypoxia is limited by continually decreasing oxygen saturation, even though exercise can be sustained despite maximal peripheral deoxygenation. There may be a cerebral autoregulation of increased perfusion accounting for the decreased arterial oxygen content and allowing for task continuation, as shown by the continued cerebral deoxygenation.
Effects of hypoxic interval training on cycling performance ROELS, Belle; MILLET, Grégoire P; MARCOUX, Christophe J. L ...
Medicine and science in sports and exercise,
2005, 2005-Jan, 2005-01-00, 20050101, Volume:
37, Issue:
1
Journal Article
Peer reviewed
The aim of this study was to test the hypothesis that intermittent hypoxic interval training improves sea level cycling performance more than equivalent training in hypoxia or normoxia.
Thirty-three ...well-trained cyclists and triathletes (25.9 +/- 2.7 yr, VO(2max) 66.1 +/- 6.1 mL.min(-1).kg(-1)) were divided into three groups: intermittent hypoxic (IHT, N = 11, P(I)O(2) of 100 mm Hg), intermittent hypoxic interval training (IHIT, N = 11) and normoxia (Nor, N = 11, P(I)O(2) of 160 mm Hg) and completed a 7-wk training program, consisting of two high-intensity (100 or 90% relative peak power output) interval training sessions each week. Each interval training session was performed in a laboratory on the subject's own bicycle, in normoxic or hypoxic conditions for the Nor and the IHT group, respectively. The IHIT group performed warm-up and cool-down plus recovery from each interval in hypoxic conditions. In contrast to IHT, interval exercise bouts were performed in normoxic conditions.
Mean power output during a 10-min cycle time trial improved after the first 4 wk of training by 5.2 +/- 3.9, 3.7 +/- 5.9, and 5.0 +/- 3.4% for IHIT, IHT, and Nor, respectively, without significant differences between groups. Moreover, mean power output did not show any significant improvement in the following 3 wk in any group. VO(2max) (L.min(-1)) increased only in IHIT during the training period (8.7 +/- 9.1%; P < 0.05). No changes in cycling efficiency or in hematological variables (P > 0.05) were observed.
Four weeks of interval training induced an improvement in endurance performance. However, short-term exposure to hypoxia (approximately 114 min.wk(-1)) did not elicit a greater increase in performance or any hematological modifications.
Archaeological excavations of historical fishing sites across the North Atlantic have recovered high quantities of Atlantic cod (Gadus morhua) bones. In the current study we use Atlantic cod otoliths ...from archaeological excavations of a historical fishing sites in north-west Iceland, dated to AD 970 -AD 1910 to examine historical growth trajectories of cod. No large scale growth variations or shifts in growth patterns were observed in the current chronologies, supporting the stability of historical Atlantic cod growth trajectories. The most significant variation in growth patterns was consistent with those that have been observed in recent times, for example, reduced early juvenile growth during periods of colder ocean temperature. The current results represent a high resolution chronological record of north-east Atlantic cod growth, greatly increasing the prior temporal range of such data, thereby providing a valuable baseline for a broad range of studies on Atlantic cod growth.
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Triathlon competitions are performed over markedly different distances and under a variety of technical constraints. In 'standard-distance' triathlons involving 1.5km swim, 40km cycling and 10km ...running, a World Cup series as well as a World Championship race is available for 'elite' competitors. In contrast, 'age-group' triathletes may compete in 5-year age categories at a World Championship level, but not against the elite competitors. The difference between elite and age-group races is that during the cycle stage elite competitors may 'draft' or cycle in a sheltered position; age-group athletes complete the cycle stage as an individual time trial. Within triathlons there are a number of specific aspects that make the physiological demands different from the individual sports of swimming, cycling and running. The physiological demands of the cycle stage in elite races may also differ compared with the age-group format. This in turn may influence performance during the cycle leg and subsequent running stage. Wetsuit use and drafting during swimming (in both elite and age-group races) result in improved buoyancy and a reduction in frontal resistance, respectively. Both of these factors will result in improved performance and efficiency relative to normal pool-based swimming efforts. Overall cycling performance after swimming in a triathlon is not typically affected. However, it is possible that during the initial stages of the cycle leg the ability of an athlete to generate the high power outputs necessary for tactical position changes may be impeded. Drafting during cycling results in a reduction in frontal resistance and reduced energy cost at a given submaximal intensity. The reduced energy expenditure during the cycle stage results in an improvement in running, so an athlete may exercise at a higher percentage of maximal oxygen uptake. In elite triathlon races, the cycle courses offer specific physiological demands that may result in different fatigue responses when compared with standard time-trial courses. Furthermore, it is possible that different physical and physiological characteristics may make some athletes more suited to races where the cycle course is either flat or has undulating sections. An athlete's ability to perform running activity after cycling, during a triathlon, may be influenced by the pedalling frequency and also the physiological demands of the cycle stage. The technical features of elite and age-group triathlons together with the physiological demands of longer distance events should be considered in experimental design, training practice and also performance diagnosis of triathletes.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The Szeklers and Hungarians from Romania. This study regards, as its main topic, the possibility of establishing at present, a geodemographical entity on Romania’s territory, since certain ...representatives of the Hungarian ethnical minority in our country, and with a particular insistence of those in the vicinity of the western border, always remember to bring into view the problem of establishing an autonomy, common to a Székely Land, located in the central area of our country, which would include Mureş, Harghita and Covasna counties. Without carrying out a detailed account of this situation, it needs to be mentioned, just as it will emerge of the following presentation, that such an approach has neither the most reduced geodemographical support, since the Szeklers, after being assimilated by the Hungarian ethnic group, are no longer present at the census of 20 October 2011. By taking into account the above mentioned aspects, in order to be able to respond to the insistent requests for autonomy in Transylvania, we proceeded to highlight, through a fairly detailed approach of the Hungarian ethnical minority, obviously in point of the number of inhabitants and of their distribution on Romania’s territory, resulting of this the fact that the number of Hungarians is of 1,227,623 people, value which related to those 20,121,641 inhabitants of Romania, means 6.10%. The total number of mentioned Hungarians is characterized by a pronounced concentration on Romania’s territory, standing out by creating a corridor with a diagonal aspect, on the northwestsoutheast direction, consisting of seven counties, the first four (Satu Mare, Bihor, Sălaj and Cluj) being registered with 2.01% (404,561 inhabitants) of those 6.10% Hungarians, the following three (Mureş, Harghita and Covasna) accounting for 3.03% (609,033 inhabitants), and hence in the corridor are present 5.04% (1,013,594 Hungarians) of 6.10% at the level of the entire country. The above mentioned corridor is surrounded by a ring of 11 counties (Maramureş, Bistriţa-Năsăud, Suceava, Neamţ, Bacău, Vrancea, Buzău, Braşov, Sibiu, Alba and Arad), in which there are only 0.76% (153,397 people) of the Hungarians living in Romania, while in the other 18 counties and Bucharest municipality, the Hungarian ethnic group enrolls only with 0.30% (60,632 people) at national level (Table 7).
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