This study assessed the intrapersonal and interpersonal functioning of a three-couple expedition group that included a 2 1/2-year-old child which was ice-locked on a boat in the High Arctic during a major portion of the expedition. Personality assessment indicated that team members were generally well adjusted, scoring relatively higher on well-being and achievement and relatively lower on stress reactivity. Weekly mood ratings showed that the group exhibited significantly higher positive than negative affect. Reported negative events were relatively most frequent at the beginning of the Arctic stay and toward the end of the darkness period and were lowest during the initial darkness interval. The period of darkness had both a salutary and negative impact. A highly important means of coping with stress was seeking emotional support from one's partner. Selection of couples with strong bonds with their partner appears to be one viable approach for crew selection for long-duration missions.
In the present study we have investigated the activity concentrations of (210)Pb, (210)Po as well as (7)Be in surface air of the North and South Atlantic (1988-1989), the Arctic Ocean (1991), and along the coastline of Siberia (1994) during succeeding expeditions in the Swedish Polar Research program. During the cruises in the Arctic Ocean during 1991-07-28 to 1991-10-04 the average air concentrations of (7)Be was 0.6 ± 0.4 mBq/m(3), (210)Pb 40 ± 4 µBq/m(3) and (210)Po-38 ± 10 µBq/m(3). During the Swedish-Russian Tundra Ecology-94 expedition along the Siberian coastline the average air concentrations of (7)Be and (210)Pb measured during May-July were 11 ± 3, and 2.4 ± 0.4 mBq/m(3), and during July-September they were 7.2 ± 2 and 2.7 ± 1.1 mBq/m(3) respectively. The results from measurements of the activity concentration of (210)Pb in the air over the Arctic Ocean vary between 75 and 176 µBq/m(3). In the air close to land masses, however, the activity concentration of (210)Pb in the air increases to 269-2712 µBq/m(3). The activity concentration of (7)Be in the South Atlantic during the cruise down to Antarctica varied between 1.3 and 1.7 with an average of 1.5 ± 0.8 mBq/m(3). The activity concentration of (210)Pb in the South Atlantic down to Antarctica varied between 6 and 14 µBq/m(3). At the Equator the activity concentration recorded in November 1988 was 630 µBq/m(3) and in April 1989 it was 260 µBq/m(3). The average activity concentration of (210)Pb during the route Gothenburg-Montevideo in 1988 was 290 and on the return Montevideo-Gothenburg it was 230 µBq/m(3). The activity concentration of (210)Po in the South Atlantic down to Antarctica varied between 15 and 58 µBq/m(3). At the Equator the activity concentration in November 1988 was 170 and in April 1989 it was 70 µBq/m(3). The average activity concentration of (210)Po during the route Gothenburg-Montevideo in 1988 was 63 and on the return Montevideo-Gothenburg it was 60 µBq/m(3). The average of the activity concentrations in the Antarctic air of (210)Pb was 27 ± 10 µBq/m(3) and of (210)Po it was 12 ± 7 µBq/m(3). All our results were compiled together with other published data, and the global latitudinal distribution of (210)Pb was converted to total annual deposition (Bq/m(2)/a) and fitted to a 4th degree polynomial. By using the global latitudinal distribution of (210)Po/(210)Pb-activity ratio from our own results the global latitudinal distribution of (210)Po annual deposition was derived.
When soil nitrogen is in short supply, most terrestrial plants form symbioses with fungi (mycorrhizae): hyphae take up soil nitrogen, transport it into plant roots, and receive plant sugars in return. In ecosystems, the transfers within the pathway fractionate nitrogen isotopes so that the natural abundance of 15N in fungi differs from that in their host plants by as much as 12% per hundred. Here we present a new method to quantify carbon and nitrogen fluxes in the symbiosis based on the fractionation against 15N during transfer of nitrogen from fungi to plant roots. We tested this method, which is based on the mass balance of 15N, with data from arctic Alaska where the nitrogen cycle is well studied. Mycorrhizal fungi provided 61-86% of the nitrogen in plants; plants provided 8-17% of their photosynthetic carbon to the fungi for growth and respiration. This method of analysis avoids the disturbance of the soil-microbe-root relationship caused by collecting samples, mixing the soil, or changing substrate concentrations. This analytical technique also can be applied to other nitrogen-limited ecosystems, such as many temperate and boreal forests, to quantify the importance for terrestrial carbon and nitrogen cycling of nutrient transfers mediated by mycorrhizae at the plant-soil interface.
AIM: To specify a 24-h profile of arterial pressure (AP) in hypertensive patients working in duty regime in the Far North (Tyumen Region). MATERIAL AND METHODS: AP parameters were studied in 155 males aged 25-59 with hypertension of stage I, II who were employed for duty work in the Far North areas and 38 control patients with hypertension stage I, II living in a moderate climatic zone (Tyumen). The groups were comparable by gender, age, duration of hypertension, office systolic and diastolic AP (SAP and DAP). All the patients have undergone 24-h monitoring of AP with assessment of basic mean parameters. RESULTS: The study group patients had scare symptoms and lower mean 24-h SAP, but high AP variability, high DAD as reflection of more significant structural changes of vessels and special functioning of the autonomic nervous system in the North. Mean 24-h AP showed more unfavourable changes in hypertensive subjects who had flight from Yamburg-Moscow-Yamburg. CONCLUSION: The data of the study dictate the necessity to develop a differentiated risk strategy for health promotion, prevention and treatment of hypertension in those who work in the North of Tyumen Region in duty regime.
To study peculiar features of daily AP rhythm and profile in men with cardiovascular risk factors residing in the Far North.
The study included 115 servicemen divided into 3 groups (hypertensive disease (HD), hypertonic type neurocirculatory asthenia (NCA) and risk factor of cardiovascular diseases other than AH). HD was diagnosed based on multiple AP measurements and 24-hr monitoring.
HD was associated with elevated mean AP, load indices and AP variability All patients had pathological type of morning dynamics. Normal daily rhythm of systolic AP (SAP) was documented in 66.1% of the patients with HD and in 68% with cardiovascular risk factors without AH. Normal daily rhythm ofdiastolic AP (DAP) was recorded in 63.5% of the patients with HD and in 72% with cardiovascular risk factors without AH. In group 2, normal daily rhythms of SAP and DAP were found in 44 and 56% of the cases respectively.
Men residing in the Far North under conditions of anomalous photoperiod need medicamentous correction of AP regardless of AH type. Ambulatory BP monitoring should be preferred for the assessment of the efficacy of antihypertensive therapy.
25-hydroxyvitamin D (25[OH]D) deficiency is associated with compromised bone mineralisation, fatigue, suppressed immune function and unsatisfactory skeletal muscle recovery. We investigated the risk of 25(OH)D insufficiency or deficiency in endurance athletes compared to sedentary non-athletes living at 64° north.
University student-athletes (TS) and sedentary students (SS) volunteered to participate in this study. TS engaged in regular exercise while SS exercised no more than 20 minutes/week. Metabolic Equivalent of Task (MET) scores for participants were determined. Vitamin D intake was assessed using the National Cancer Institute's 24-hour food recall (ASA24). Fasting plasma 25(OH)D levels were quantified via enzyme-linked immunosorbent assay.
TS reported higher activity levels than SS as assessed with MET-minutes/week and ranking of physical activity levels (p
Cites: Chem Biol. 2014 Mar 20;21(3):319-29 PMID 24529992