Human Physiological Adaptations to the Arctic Climate

This review deals with thermal, metabolic and hormonal responses of various human populations to natural or experimental acclimation. Modern people react to cold with shivering, increased metabolism and cutaneous vasoconstriction (metabolic response). Native people, such as Australian aborigines, Eskimos, arctic Indians and Lapps, who were regularly exposed to cold in their natural habitat, have been reported to exhibit less pronounced shivering during experimental cold exposure and experience a greater fall in body temperature (hypometabolic and hypothermic type of adaptation). Australian aborigines and traditional Korean divers have been shown to have low body heat conductivity (insulative type of adaptation). Modern Caucasians intensively exposed to prolonged cold may also develop hypothermic and insulative types of adaptation. Exposure to cold climate increases blood pressure, which may be a factor contributing to the greater mortality due to cardiovascular diseases and stroke observed in the winter. The secretion of the pineal hormone melatonin, which is believed to inhibit the secretion of a pituitary luteinizing hormone, is elevated during winter and decreased in summer. This leads to the higher conception rate observed during spring and summer.Key words: acclimatization, birth rate, blood pressure, body temperature, cold exposure, conceptions, hormones, light, metabolic rate, mortality, native people, seasonMots clés: acclimatation, taux de natalité, pression sanguine, température du corps, exposition au froid, conception, hormones, lumière, taux de métabolisme, mortalité, autochtones, saiso

Traffic deaths of reindeer in Finland during 1974 — 83

During 1974 — 83 a total of 23.298 reindeer died in traffic accidents in Finland. Vehicles killed 19.962 reindeer (85,7% of traffic deaths) and trains 3.336 reindeer (14,3%). During 1978 — 82 the majority of reindeer killed by vehicles were hinds (52,2%) and calves (24,6%). Reindeer road deaths were concentrated in the southern and central, heavily trafficked herding areas. Most reindeer were killed by vehicles in the marked herding areas of Pudasjårvi, Kuusamo, Raudanjoki and Sodankyiå. The most destructive section of road was highway number 20 between Pudasjårvi and Taivalkoski where 559 reindeer died during 1978 — 82 on a 36 km stretch. The worst railway stretch was between Ii and Kemi where an average of 115 reindeer/10 km died during 1976 — 82. Most reindeer died in traffic in November, December and January during the soft snow period when the movement of reindeer is most difficult. In summer, most reindeer died in traffic in July — August. The number of reindeer deaths on the roads in May — September depended slightly on the temperature in the different months (r=0,398). Throughout the whole reindeer herding area the amount of reindeer deaths also depended on the average 24-hour traffic (r=0,445).Porojen liikennekuolemat Suomessa 1974 — 83.Abstract in Finnish / Yhteenveto: Vuosina 1974—83 kuoli liikenteesså Suomessa yhteenså 23.298 poroa. Auton alle jåi 19.962 poroa (85,7% liikennekuolemista) ja junan alle 3.336 poroa (14,3%). Vuosina 1978—82 oli autojen alle jååneistå poroista suurin osa vaatimia (52,2%) ja vasoja (24,6%). Porojen maantiekuolemat keskittyivåt etelå- ja keskiosan pieniin ja runsaasti liikennoityihin paliskuntiin. Eniten poroja jåi auton alle Pudasjårven, Kuusamon, Raudanjoen ja Sodankylån merkkipiirien paliskunnissa. Tuhoisin tieosuus oli valtatie n:o 20 vålillå Pudasjårvi—Taivalkoski, jossa kuoli vuosina 1978—82 yhteenså 559 poroa 36 km:n matkalla. Pahin rataosuus olivålillå li—Kemi, jossa kuoli vuosina 1976—82 keskimaårin yli 115 poroa/10 km. Eniten poroja kuoli liikenteesså marras-, joulu- ja tammikuussa pehmeån lumen aikaan, jolloin porojen liikkuminen vaikeutui eniten. Kesållå kuoli liikentesså eniten poroja heinå—elokuussa. Touko—syyskuussa porokuolemien måårå maanteillå riippui eri kuukausina hieman ilman låmpotilasta (r=0,398). Koko poronhoitoalueella porokuolemien måårå riippui myos keskimååråisestå vuorokautisesta liikenteestå (r=0,445).Renarnas trafikdödlighet i Finland under åren 1974-1983Abstract in Swedish / Sammandrag: Under åren 1974—83 dog i trafiken i Finland sammanlagt 23.298 renar. Av dessa blev 19.692 påkorda (85,7%) av bilar och 3.336 av tåg (14,3%). Under åren 1978—82 var merparten av de av bilar påkorda renarna vajor (52,2%) och kalvar (24,6%). Renarnas landsvågsdodlighet koncentrerade sig till de små hårt trafikerade renbeteslagen i de mellersta och de sydliga delarna av renskotselområdet. Flest renar blev overkorda av bilar i Pudasjårvi, Kuusamo, Raudanjoki och Sodankyiå mårkesdistrikts renbeteslag. Den vårsta vågstråckan var riksvåg nr. 20 mellan Pudasjårvi och Taivalkoski, dår under åren 1978—82 sammanlagt 559 renar dog på en stråcka av 36 km. Den varsta jårnvågsstråckan var mellan li och Kemi, dår under åren 1976—82 i genomsnitt over 115 renar/10 km dog. Flest renar dog i trafiken i november, december och januari då snon var som mjukast och renarnas rorlighet forsvårades som mest. Under sommaren dog flest renar i juli—augusti. Under maj—september fanns det en korrelation mellan renarnas trafikdodlighet på landsvågarna och luftens temperatur (r=0,398). I hela renskotselområdet fanns det också en korrelation mellan rendodligheten och den genomsnittliga dygnstrafiken (r=0,445)

Predation in the reindeer husbandry area in Finland during 1976-86

During the years 1976-86 predators killed a total of 11 295 reindeer in the Finnish reindeer husbandry area. Predators killed mostly calves and hinds. With the exception of the Kåsivarsi and Muotkatun-turi reindeer herding cooperatives, kills of predators were concentrated in the reindeer herding areas on the eastern border. During 1976-86 predators killed most reindeer in April - June, and the majority of preys were calves. Most reindeer were killed by wolves (26.9%), bears (24.7%), wolverines (22.6%) and eagles (15.9%). Wolves, bears, wolverines and lynxes killed mainly adult reindeer, eagles killed mainly calves. Wolves killed reindeer mainly during October - January, lynxes during January - April, wolverines during February - April, eagles during May - July and bears during May - October. During the last years the number of reindeer killed by lynxes has increased in Finland.Petovahingot Suomen poronhoitoalueella vuosina 1976-86.Abstract in Finnish / Yhteenveto: Viimeisen kymmenen vuoden aikana porojen måårå on lisååntynyt suuresti Suomessa. Vuosina 1976-86 pedot tappoivat Suomen poronhoitoalueella yhteenså 11 295 poroa. Pedot tappoivat pååasiassa vasoja ja vaatimia. Käsivarren ja Muotkatunturin paliskuntia lukuunottamatta petovahingot kohdistuivat lhinn poronhoitoalueen itrajalla oleviin paliskuntiin. Vuosina 1976-86 pedot tappoivat poroja eniten huhti-kesåkuun aikana. Eniten pedot tappoivat tuolloin vasoja. Eniten poroja tappoivat sudet (26.9%), karhut (24.7%), ahmat (22.6%) ja kotkat (15.9%). Sudet, karhut, ahmat ja ilvekset tappoivat pååasiassa aikuisia poroja, kotkat vasoja. Sudet tappoivat poroja låhinnå loka-tammikuussa, ilvekset tammi-huhtikuussa, ahmat helmi-heinåkuussa ja karhut touko-lokakuussa. Viime vuosina ilvesten tappamien porojen måårå on kas vanut Suomessa.Rovdjursskador inom det finska renskotselsområdet under åren 1976-86.Abstract in Swedish / Sammandrag: Under de senaste tio åren har antalet tamrenar ökat betydligt i Finland. Under åren 1976-86 dodade rovdjur totalt 11 295 renar i finska renskotselområdet. Kalvar och vajor utgjorde huvuddelen av dessa. Med undantag av Kåsivarsi och Muotkatunturi renbeteslag, var rovdjursrivningarna konsentrerade i renbeteslagen nårmast ostra grånsen. Under åren 1976-86 blev de fiesta renar rivna i april-juni. Av dessa var det flest kalvar. Varg tog flest renar (26,9%), bjorn 24,7%, jårv 22,6%, och orn 15,9%. Varg, bjorn, jårv och lo dodade mestadels vuxna renar, medan orn i huvudsak tog kalvar. Varg dodade ren våsentligen i månaderna oktober-januari, lo i januari-april, jårv i februari-april, orn i mai-juli och bjorn genom må-naderna mai-oktober. De senaste åren har antalet renar rivna av lodjur okat i Finland

Damage from predation on the reindeer husbandry area in Finland during the years 1976-83

During the years 1976-1983 predators killed a total of 8900 reindeer in Finland. The highest numbers of reindeer killed by predators were found in the marked areas of Inari, Kuusamo and Sodankyla and in the reindeer herding areas of Kasivarsi (a total of 873 reindeer), Kemi-Sompio (731), Lappi (658) and northern Salla (632). With the exception of the Kasivarsi reindeer herding area, predator damage was more or less concentrated on the reindeer herding areas on the eastern border. During 1977- 1982 the majority of reindeer killed by predators were hinds (49,6%) and calves (41,0%). Predators killed most reindeer in April-June. In May and June the majority of reindeer killed by predators were calves. During 1977-83 most reindeer were killed by wolves (27,6%). wolverine (25,4%), bear (24,8%) and eagles (14,5%). Wolves killed reindeer mainly in the autumn and early winter during the soft snow period. Wolverine and lynx killed reindeer in February-April in crusted snow conditions. Bears killed most reindeer during the calving period in May-June and reindeer killed by eagles were found in plenty in spring and summer.Petovahingot Suomen poronhoitoalueella vuosina 1976-83.Abstract in Finnish / Yhteenveto: Vuosina 1976-83 pedot tappoivat Suomessa yhteenså 8 900 poroa. Eniten petojen tappamia poroja lôytyin Inarin, Kuusamon ja Sodankylån merkkipiireisså sekå Kåsivarren (yhteenså 873 poroa), Kemin-Sompion (731), Lapin (685), ja Sallan pohjoisen (632) paliskunnissa. Kåsivarren paliskuntaa lukuunottamatta petovahingot keskittyivåt låhinnå itårajan paliskuntiin. Vuosina 1977-82 petojen tappamista poroista suurin osa oli vaatimia (49,6%) ja vasoja (41,0%). Eniten pedot tappoivat poroja huhti - kesåkuun aikana. Tuoko - ja kesåkuussa suurin osa petojen tappamista poroista oli vasoja. Vuosina 1977-83 eniten poroja tappoivat susi (27,6%), ahma (25,4%), karhu (24,8%) ja kokta (14,5%). Sudet tappoivat poroja pååasiassa syksyllå ja alkutalvella pehmeån lumen aikana. Ahma ja ilves tappoivat poroja helmi - huhtikuun hankikeleillå. Karhu tappoi eniten poroja vasonta-aikana touko - kesåkuussa, ja kotkan tappamia poroja lôytyi runsaasti kevåållå ja kesållå.Rovdjurskadorna inom Finlands renskötselområde under åren 1976-83.Abstract in Swedish / Sammandrag: Under åren 1976-83 dôdades i Finland 8900 renar av rovdjur. Flest rovdjursrivna renar påtråffades inom Enares, Kuusamos och Sodankylås màrkesdistrikt samt inom Kàsivarsis (sammanlagt 873 renar), Kemin-Sompios (731), Lappis (685) och Salla pohjoinens (632) renbeteslag. Fôrutom til Kàsivarsis renbeteslag koncentrerades rovdjursskadorna, framst till renbeteslagen vid ostgrånsen. Under åren 1977-82 var stôrsta delen av de rovdjursrivna renarna vajor (49,6%) och kalvar (41,0%). Flest renar dôdades av rovdjur under april-juni. Under maj-juni var stôrsta delen av de rovdjursrivna renar kalvar. Under åren 1977-83 dôdades flest renar av varg (27,6%), jarv (25,4%) bjôrn (24,8%) och orn (14,5%). Vargar dôdade renar huvudsakligen på hosten och i bôrjan av vintern, då snôn var som losast. Skadorna vållade av jarv och lo koncentrade sig framst till skarfôret i februari-april. Bjôrnen dôdade flest renar under kalvningstiden i maj-juni, medan ganska stort antal av ôrn dôdade renar påtråffades under våren och sommaren

(Neuro) Peptides, Physical Activity, and Cognition

Regular physical activity (PA) improves cognitive functions, prevents brain atrophy, and delays the onset of cognitive decline, dementia, and Alzheimer's disease. Presently, there are no specific recommendations for PA producing positive effects on brain health and little is known on its mediators. PA affects production and release of several peptides secreted from peripheral and central tissues, targeting receptors located in the central nervous system (CNS). This review will provide a summary of the current knowledge on the association between PA and cognition with a focus on the role of (neuro)peptides. For the review we define peptides as molecules with less than 100 amino acids and exclude myokines. Tachykinins, somatostatin, and opioid peptides were excluded from this review since they were not affected by PA. There is evidence suggesting that PA increases peripheral insulin growth factor 1 (IGF-1) levels and elevated serum IGF-1 levels are associated with improved cognitive performance. It is therefore likely that IGF-1 plays a role in PA induced improvement of cognition. Other neuropeptides such as neuropeptide Y (NPY), ghrelin, galanin, and vasoactive intestinal peptide (VIP) could mediate the beneficial effects of PA on cognition, but the current literature regarding these (neuro)peptides is limited.Peer reviewe

(Neuro) Peptides, Physical Activity, and Cognition

Regular physical activity (PA) improves cognitive functions, prevents brain atrophy, and delays the onset of cognitive decline, dementia, and Alzheimer's disease. Presently, there are no specific recommendations for PA producing positive effects on brain health and little is known on its mediators. PA affects production and release of several peptides secreted from peripheral and central tissues, targeting receptors located in the central nervous system (CNS). This review will provide a summary of the current knowledge on the association between PA and cognition with a focus on the role of (neuro)peptides. For the review we define peptides as molecules with less than 100 amino acids and exclude myokines. Tachykinins, somatostatin, and opioid peptides were excluded from this review since they were not affected by PA. There is evidence suggesting that PA increases peripheral insulin growth factor 1 (IGF-1) levels and elevated serum IGF-1 levels are associated with improved cognitive performance. It is therefore likely that IGF-1 plays a role in PA induced improvement of cognition. Other neuropeptides such as neuropeptide Y (NPY), ghrelin, galanin, and vasoactive intestinal peptide (VIP) could mediate the beneficial effects of PA on cognition, but the current literature regarding these (neuro)peptides is limited.Peer reviewe

Step Detection Accuracy and Energy Expenditure Estimation at Different Speeds by Three Accelerometers in a Controlled Environment in Overweight/Obese Subjects

Our aim was to compare three research-grade accelerometers for their accuracy in step detection and energy expenditure (EE) estimation in a laboratory setting, at different speeds, especially in overweight/obese participants. Forty-eight overweight/obese subjects participated. Participants performed an exercise routine on a treadmill with six different speeds (1.5, 3, 4.5, 6, 7.5, and 9 km/h) for 4 min each. The exercise was recorded on video and subjects wore three accelerometers during the exercise: Sartorio Xelometer (SX, hip), activPAL (AP, thigh), and ActiGraph GT3X (AG, hip), and energy expenditure (EE) was estimated using indirect calorimetry for comparisons. For step detection, speed-wise mean absolute percentage errors for the SX ranged between 9.73-2.26, 6.39-0.95 for the AP, and 88.69-2.63 for the AG. The activPALs step detection was the most accurate. For EE estimation, the ranges were 21.41-15.15 for the SX, 57.38-12.36 for the AP, and 59.45-28.92 for the AG. All EE estimation errors were due to underestimation. All three devices were accurate in detecting steps when speed exceeded 4 km/h and inaccurate in EE estimation regardless of speed. Our results will guide users to recognize the differences, weaknesses, and strengths of the accelerometer devices and their algorithms.Peer reviewe