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1.
Glob Chang Biol ; 30(1): e17043, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37988234

RESUMEN

In the northern high latitudes, warmer spring temperatures generally lead to earlier leaf onsets, higher vegetation production, and enhanced spring carbon uptake. Yet, whether this positive linkage has diminished under climate change remains debated. Here, we used atmospheric CO2 measurements at Barrow (Alaska) during 1979-2020 to investigate the strength of temperature dependence of spring carbon uptake reflected by two indicators, spring zero-crossing date (SZC) and CO2 drawdown (SCC). We found a fall and rise in the interannual correlation of temperature with SZC and SCC (RSZC-T and RSCC-T ), showing a recent reversal of the previously reported weakening trend of RSZC-T and RSCC-T . We used a terrestrial biosphere model coupled with an atmospheric transport model to reproduce this fall and rise phenomenon and conducted factorial simulations to explore its potential causes. We found that a strong-weak-strong spatial synchrony of spring temperature anomalies per se has contributed to the fall and rise trend in RSZC-T and RSCC-T , despite an overall unbroken temperature control on net ecosystem CO2 fluxes at local scale. Our results provide an alternative explanation for the apparent drop of RSZC-T and RSCC-T during the late 1990s and 2000s, and suggest a continued positive linkage between spring carbon uptake and temperature during the past four decades. We thus caution the interpretation of apparent climate sensitivities of carbon cycle retrieved from spatially aggregated signals.


Asunto(s)
Carbono , Ecosistema , Temperatura , Dióxido de Carbono , Estaciones del Año , Ciclo del Carbono , Cambio Climático
2.
Glob Chang Biol ; 30(10): e17508, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39377278

RESUMEN

Disentangling the influences of climate change from other stressors affecting the population dynamics of aquatic species is particularly pressing for northern latitude ecosystems, where climate-driven warming is occurring faster than the global average. Chinook salmon (Oncorhynchus tshawytscha) in the Yukon-Kuskokwim (YK) region occupy the northern extent of their species' range and are experiencing prolonged declines in abundance resulting in fisheries closures and impacts to the well-being of Indigenous people and local communities. These declines have been associated with physical (e.g., temperature, streamflow) and biological (e.g., body size, competition) conditions, but uncertainty remains about the relative influence of these drivers on productivity across populations and how salmon-environment relationships vary across watersheds. To fill these knowledge gaps, we estimated the effects of marine and freshwater environmental indicators, body size, and indices of competition, on the productivity (adult returns-per-spawner) of 26 Chinook salmon populations in the YK region using a Bayesian hierarchical stock-recruitment model. Across most populations, productivity declined with smaller spawner body size and sea surface temperatures that were colder in the winter and warmer in the summer during the first year at sea. Decreased productivity was also associated with above average fall maximum daily streamflow, increased sea ice cover prior to juvenile outmigration, and abundance of marine competitors, but the strength of these effects varied among populations. Maximum daily stream temperature during spawning migration had a nonlinear relationship with productivity, with reduced productivity in years when temperatures exceeded thresholds in main stem rivers. These results demonstrate for the first time that well-documented declines in body size of YK Chinook salmon were associated with declining population productivity, while taking climate into account.


Asunto(s)
Tamaño Corporal , Cambio Climático , Ecosistema , Salmón , Animales , Salmón/fisiología , Temperatura , Dinámica Poblacional , Estaciones del Año , Teorema de Bayes , El Yukón
3.
Proc Natl Acad Sci U S A ; 118(16)2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33846246

RESUMEN

The high northern latitudes (>50°) experienced a pronounced surface stilling (i.e., decline in winds) with climate change. As a drying factor, the influences of changes in winds on the date of autumn foliar senescence (DFS) remain largely unknown and are potentially important as a mechanism explaining the interannual variability of autumn phenology. Using 183,448 phenological observations at 2,405 sites, long-term site-scale water vapor and carbon dioxide flux measurements, and 34 y of satellite greenness data, here we show that the decline in winds is significantly associated with extended DFS and could have a relative importance comparable with temperature and precipitation effects in contributing to the DFS trends. We further demonstrate that decline in winds reduces evapotranspiration, which results in less soil water losses and consequently more favorable growth conditions in late autumn. In addition, declining winds also lead to less leaf abscission damage which could delay leaf senescence and to a decreased cooling effect and therefore less frost damage. Our results are potentially useful for carbon flux modeling because an improved algorithm based on these findings projected overall widespread earlier DFS than currently expected by the end of this century, contributing potentially to a positive feedback to climate.


Asunto(s)
Hojas de la Planta/metabolismo , Árboles/metabolismo , Viento , Altitud , Ciclo del Carbono/fisiología , China , Clima , Cambio Climático , Ecosistema , Tecnología de Sensores Remotos/métodos , Estaciones del Año , Temperatura , Tiempo (Meteorología)
4.
Glob Chang Biol ; 29(6): 1530-1544, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36495084

RESUMEN

Climate warming is leading to permafrost thaw in northern peatlands, and current predictions suggest that thawing will drive greater surface wetness and an increase in methane emissions. Hydrology largely drives peatland vegetation composition, which is a key element in peatland functioning and thus in carbon dynamics. These processes are expected to change. Peatland carbon accumulation is determined by the balance between plant production and peat decomposition. But both processes are expected to accelerate in northern peatlands due to warming, leading to uncertainty in future peatland carbon budgets. Here, we compile a dataset of vegetation changes and apparent carbon accumulation data reconstructed from 33 peat cores collected from 16 sub-arctic peatlands in Fennoscandia and European Russia. The data cover the past two millennia that has undergone prominent changes in climate and a notable increase in annual temperatures toward present times. We show a pattern where European sub-Arctic peatland microhabitats have undergone a habitat change where currently drier habitats dominated by Sphagnum mosses replaced wetter sedge-dominated vegetation and these new habitats have remained relatively stable over the recent decades. Our results suggest an alternative future pathway where sub-arctic peatlands may at least partly sustain dry vegetation and enhance the carbon sink capacity of northern peatlands.


Asunto(s)
Secuestro de Carbono , Sphagnopsida , Ecosistema , Suelo , Carbono
5.
J Exp Biol ; 226(21)2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37815465

RESUMEN

Insectivorous bats at northern latitudes need to cope with long periods of no food for large parts of the year. Hence, bats which are resident at northern latitudes throughout the year will need to undergo a long hibernation season and a short reproductive season where foraging time is limited by extended daylight periods. Eptesicus nilssonii is the northernmost occurring bat species worldwide and hibernates locally when ambient temperatures (Ta) limit prey availability. Therefore, we investigated the energy spent maintaining normothermy at different Ta, as well as how much bats limit energy expenditure while in torpor. We found that, despite being exposed to Ta as low as 1.1°C, bats did not increase torpid metabolic rate, thus indicating that E. nilssonii can survive and hibernate at low ambient temperatures. Furthermore, we found a lower critical temperature (Tlc) of 27.8°C, which is lower than in most other vespertilionid bats, and we found no indication of any metabolic response to Ta up to 37.1°C. Interestingly, carbon dioxide production increased with increasing Ta above the Tlc, presumably caused by a release of retained CO2 in bats that remained in torpor for longer and aroused at Ta above the Tlc. Our results indicate that E. nilssonii can thermoconform at near-freezing Ta, and hence maintain longer torpor bouts with limited energy expenditure, yet also cope with high Ta when sun exposed in roosts during long summer days. These physiological traits are likely to enable the species to cope with ongoing and predicted climate change.


Asunto(s)
Quirópteros , Hibernación , Letargo , Animales , Temperatura , Quirópteros/fisiología , Regulación de la Temperatura Corporal/fisiología , Frío , Hibernación/fisiología , Metabolismo Energético/fisiología
6.
Sensors (Basel) ; 23(4)2023 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-36850658

RESUMEN

In this article, a cluster comprised of eight Continuously Operating Reference Station (CORS) receivers surrounding five supplemental test stations located on much shorter baselines is used to form a composite multi-scale network for the purpose of isolating, extracting, and analyzing ionospheric spatial gradient phenomena. The purpose of this investigation is to characterize the levels of spatial decorrelation between the stations in the cluster during the periods with increased ionospheric activity. The location of the selected receiver cluster is at the auroral zone at night-time (cluster centered at about 69.5° N, 19° E) known to frequently have increased ionospheric activity and observe smaller size of high-density irregularities. As typical CORS networks are relatively sparse, there is a possibility that spatially small-scale ionospheric delay gradients might not be observed by the network/closest receiver cluster but might affect the user, resulting in residual errors affecting system accuracy and integrity. The article presents high level statistical observations based on several hundred manually validated ionospheric spatial gradient events along with low level analysis of specific events with notable temporal/spatial characteristics.

7.
Environ Res ; 210: 112938, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35176315

RESUMEN

As the most important contributors to global warming in recent decades, anthropogenic carbon dioxide (CO2) and black carbon (BC) play significant roles in driving the global/regional hydrological cycle. Most of previous studies on the climate effects of CO2 and BC focused on tropics and monsoon regions. The influences and their differences of CO2 and BC on the precipitation in Northern Hemisphere mid-latitudes (NHML) have not been paid enough attention. Here we investigate the NHML precipitation responses to a tenfold increase in BC and a doubling of CO2 by analyzing the multi-model simulation results from the Precipitation Driver Response Model Intercomparison Project (PDRMIP). Our results show that the NHML precipitation changes induced by BC and CO2 distinctly differ in trends and seasons. The increased BC will reduce the NHML precipitation, especially in summer, whereas the doubled CO2 will enhance the regional precipitation, mainly in winter. The differences between the BC and CO2 induced NHML precipitation changes are most distinct in Central Asia and central North America. Further analyses reveal the underlying mechanisms of the distinct responses of precipitation: the decrease in NHML precipitation induced by BC aerosols mainly results from the dynamic effect by reducing the temperature gradient, thereby weakening the zonal wind, while the increased precipitation by CO2 is caused by the increase in atmospheric water vapor through the thermodynamic effect. The results of these simulations are helpful for understanding the mechanism of anthropogenic precipitation changes in mid-latitudes.


Asunto(s)
Dióxido de Carbono , Cambio Climático , Aerosoles , Dióxido de Carbono/análisis , Hollín/análisis , Viento
8.
Int J Mol Sci ; 23(22)2022 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-36430818

RESUMEN

The growing region of herbaceous peony (Paeonia lactiflora) has been severely constrained due to the intensification of global warming and extreme weather events, especially at low latitudes. Assessing and selecting stress-tolerant and high-quality peony germplasm is essential for maintaining the normal growth and application of peonies under adverse conditions. This study proposed a modified multi-criteria decision-making (MCDM) model for assessing peonies adapted to low-latitude climates based on our previous study. This model is low-cost, timesaving and suitable for screening the adapted peony germplasm under hot and humid climates. The evaluation was conducted through the analytic hierarchy process (AHP), three major criteria, including adaptability-related, ornamental feature-related and growth habits-related criteria, and eighteen sub-criteria were proposed and constructed in this study. The model was validated on fifteen herbaceous peonies cultivars from different latitudes. The results showed that 'Meiju', 'Hang Baishao', 'Hongpan Tuojin' and 'Bo Baishao' were assessed as Level I, which have strong growth adaptability and high ornamental values, and were recommended for promotion and application at low latitudes. The reliability and stability of the MCDM model were further confirmed by measuring the chlorophyll fluorescence of the selected adaptive cultivars 'Meiju' and 'Hang Baishao' and one maladaptive cultivar 'Zhuguang'. This study could provide a reference for the introduction, breeding and application of perennials under everchanging unfavorable climatic conditions.


Asunto(s)
Paeonia , Reproducibilidad de los Resultados , Fitomejoramiento , Plantas
9.
Emerg Infect Dis ; 27(1): 271-274, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33350926

RESUMEN

Naegleria fowleri is a free-living ameba that causes primary amebic meningoencephalitis (PAM), a rare but usually fatal disease. We analyzed trends in recreational water exposures associated with PAM cases reported during 1978-2018 in the United States. Although PAM incidence remained stable, the geographic range of exposure locations expanded northward.


Asunto(s)
Amebiasis , Amoeba , Infecciones Protozoarias del Sistema Nervioso Central , Meningoencefalitis , Naegleria fowleri , Infecciones Protozoarias del Sistema Nervioso Central/epidemiología , Infecciones Protozoarias del Sistema Nervioso Central/etiología , Humanos , Meningoencefalitis/epidemiología , Meningoencefalitis/etiología , Naegleria fowleri/genética , Estados Unidos/epidemiología , Agua
10.
J Invertebr Pathol ; 171: 107343, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32057749

RESUMEN

Gynaikothrips uzeli gall thrips are protected from insecticide exposure by their leaf gall habitat. A biocontrol strategy based on entomopathogenic fungi is an alternative approach for the control of G. uzeli. Higher temperatures can promote the reproduction and spread of pests; however, the impact of higher temperatures on biological control is unclear. We studied the immunocompetence of thrips from different latitudes and determined the effect of degree days on thrips immunity. We examined the potential impact of temperature on the biocontrol provided by entomopathogenic fungi. Beauveria bassiana pathogenicity against thrips increased with decreasing latitude, suggesting that immunity of thrips increased as latitude increased. The phenoloxidase activity of G. uzeli increased with increasing latitude but there was no significant change in hemocyte concentration. This indicated that the humoral immunity of thrips was significantly associated with degree days, and this was confirmed by transcriptome data. Transcriptome and RT-PCR results showed that the expression of key genes in eight toll pathways increased with increasing latitude. The relative expression of key genes in the Toll pathway of thrips and the activity of phenoloxidase decreased with increasing degree days that are characteristic of lower latitudes. These changes led to a decrease in humoral immunity. The immunity of G. uzeli against entomopathogenic fungi increased as degree days characteristic of lower latitudes decreased. Increased temperatures associated with lower latitude may therefore increase biocontrol efficacy. This study clarified immune level changes and molecular mechanisms of thrips under different degree days.


Asunto(s)
Beauveria/fisiología , Inmunocompetencia , Thysanoptera/inmunología , Distribución Animal , Animales , Control de Insectos , Control Biológico de Vectores , Thysanoptera/microbiología
11.
Int J Biometeorol ; 63(6): 763-775, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30805728

RESUMEN

Recent climate warming has altered plant phenology at northern European latitudes, but conclusions regarding the spatial patterns of phenological change and relationships with climate are still challenging as quantitative estimates are strongly diverging. To generate consistent estimates of broad-scale spatially continuous spring plant phenology at northern European latitudes (> 50° N) from 2000 to 2016, we used a novel vegetation index, the plant phenology index (PPI), derived from MODerate-resolution Imaging Spectroradiometer (MODIS) data. To obtain realistic and strong estimates, the phenology trends and their relationships with temperature and precipitation over the past 17 years were analyzed using a panel data method. We found that in the studied region the start of the growing season (SOS) has on average advanced by 0.30 day year-1. The SOS showed an overall advancement rate of 2.47 day °C-1 to spring warming, and 0.18 day cm-1 to decreasing precipitation in spring. The previous winter and summer temperature had important effects on the SOS but were spatially heterogeneous. Overall, the onset of SOS was delayed 0.66 day °C-1 by winter warming and 0.56 day °C-1 by preceding summer warming. The precipitation in winter and summer influenced the SOS in a relatively weak and complex manner. The findings indicate rapid recent phenological changes driven by combined seasonal climates in northern Europe. Previously unknown spatial patterns of phenological change and relationships with climate drivers are presented that improve our capacity to understand and foresee future climate effects on vegetation.


Asunto(s)
Cambio Climático , Desarrollo de la Planta , Europa (Continente) , Estaciones del Año , Temperatura
12.
Int J Mol Sci ; 20(1)2019 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-30609821

RESUMEN

Marine picocyanobacteria belonging to Synechococcus are major contributors to the global carbon cycle, however the genomic information of its cold-adapted members has been lacking to date. To fill this void the genome of a cold-adapted planktonic cyanobacterium Synechococcus sp. CS-601 (SynAce01) has been sequenced. The genome of the strain contains a single chromosome of approximately 2.75 MBp and GC content of 63.92%. Gene prediction yielded 2984 protein coding sequences and 44 tRNA genes. The genome contained evidence of horizontal gene transfer events during its evolution. CS-601 appears as a transport generalist with some specific adaptation to an oligotrophic marine environment. It has a broad repertoire of transporters of both inorganic and organic nutrients to survive in inhospitable environments. The cold adaptation of the strain exhibited characteristics of a psychrotroph rather than psychrophile. Its salt adaptation strategy is likely to rely on the uptake and synthesis of osmolytes, like glycerol or glycine betaine. Overall, the genome reveals two distinct patterns of adaptation to the inhospitable environment of Antarctica. Adaptation to an oligotrophic marine environment is likely due to an abundance of genes, probably acquired horizontally, that are associated with increased transport of nutrients, osmolytes, and light harvesting. On the other hand, adaptations to low temperatures are likely due to prolonged evolutionary changes.


Asunto(s)
Genoma Bacteriano , Synechococcus/genética , Adaptación Fisiológica , Regiones Antárticas , Composición de Base , Frío , Hibridación Genómica Comparativa , Ecosistema , Ontología de Genes , Sistemas de Lectura Abierta/genética , Filogenia , ARN Ribosómico 16S/química , ARN Ribosómico 16S/clasificación , ARN Ribosómico 16S/genética , Synechococcus/clasificación
13.
Glob Chang Biol ; 24(2): e577-e591, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29055169

RESUMEN

Caves may offer suitable refugia for troglophilic invertebrates during periods of unfavourable climatic conditions because of their stable microclimates. As a consequence, allopatric divergence from their epigean counterparts may occur, leading to formation of truly hypogean communities (the Climatic Relict Hypothesis). Unlike the well-studied effects of Pleistocene glaciations, we know little about how ancient climate changes drove the development of cave-dwelling organisms living at both middle and lower latitudes. We investigate the evolutionary history of the troglophilic spider genus Nesticella (Araneae, Nesticidae) in relation to Asian Neogene (23-2.6 Ma) climatic changes. Our analyses discern clear differences in the evolution of the two main clades of Nesticella, which occur in temperate/subtropical and tropical latitudes. Eastern Asian Nesticella gradually evolved greater sedentariness and a strict subterranean lifestyle starting from the middle Miocene Epoch (~15-14 Ma) in conjunction with the progressive deterioration of the climate and vegetational shifts. Caves appear to have acted as refugia because of their internally uniform temperature and humidity, which allowed these spiders to survive increasing external seasonality and habitat loss. In contrast, a uniform accumulation of lineages, long-lasting times for dispersals and the lack of a comparable habitat shifting characterized the tropical lineage. This difference in pattern likely owes to the mild effects of climate change at low latitudes and the consequent lack of strong climatic drivers in tropical environments. Thus, the mid-Miocene climatic shift appears to be the major evolutionary force shaping the ecological differences between Asian troglophilic invertebrates and the driver of the permanent hypogean communities in middle latitudes.


Asunto(s)
Cambio Climático , Filogenia , Arañas/genética , Clima Tropical , Animales , Asia , Biodiversidad , Evolución Biológica , Arañas/clasificación
14.
Br J Nutr ; 117(6): 829-838, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28382877

RESUMEN

In a longitudinal study including 642 healthy 8-11-year-old Danish children, we investigated associations between vitamin D dependent SNP and serum 25-hydroxyvitamin D (25(OH)D) concentrations across a school year (August-June). Serum 25(OH)D was measured three times for every child, which approximated measurements in three seasons (autumn, winter, spring). Dietary and supplement intake, physical activity, BMI and parathyroid hormone were likewise measured at each time point. In all, eleven SNP in four vitamin D-related genes: Cytochrome P450 subfamily IIR1 (CYP2R1); 7-dehydrocholesterol reductase/nicotinamide adenine dinucleotide synthetase-1(DHCR7/NADSYN1); group-specific complement (GC); and vitamin D receptor were genotyped. We found minor alleles of CYP2R1 rs10500804, and of GC rs4588 and rs7041 to be associated with lower serum 25(OH)D concentrations across the three seasons (all P<0·01), with estimated 25(OH)D differences of -5·8 to -10·6 nmol/l from major to minor alleles homozygosity. In contrast, minor alleles homozygosity of rs10741657 and rs1562902 in CYP2R1 was associated with higher serum 25(OH)D concentrations compared with major alleles homozygosity (all P<0·001). Interestingly, the association between season and serum 25(OH)D concentrations was modified by GC rs7041 (P interaction=0·044), observed as absence of increase in serum 25(OH)D from winter to spring among children with minor alleles homozygous genotypes compared with the two other genotypes of rs7041 (P<0·001). Our results suggest that common genetic variants are associated with lower serum 25(OH)D concentrations across a school year. Potentially due to modified serum 25(OH)D response to UVB sunlight exposure. Further confirmation and paediatric studies investigating vitamin D-related health outcomes of these genotypic differences are needed.


Asunto(s)
Alelos , Genotipo , Polimorfismo de Nucleótido Simple , Estaciones del Año , Rayos Ultravioleta , Deficiencia de Vitamina D/genética , Vitamina D/análogos & derivados , Niño , Colestanotriol 26-Monooxigenasa/genética , Familia 2 del Citocromo P450/genética , Dinamarca , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/genética , Receptores de Calcitriol/genética , Instituciones Académicas , Vitamina D/sangre , Deficiencia de Vitamina D/sangre , Proteína de Unión a Vitamina D/genética
15.
J Sci Food Agric ; 97(11): 3500-3508, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28026010

RESUMEN

BACKGROUND: Broccoli (Brassica oleracea L. var. italica) is a popular vegetable grown at a wide range of latitudes. Plants were grown in 2009-2011 in pots with standardized soil, irrigation and nutrient supply under natural temperature and light conditions at four locations (42-70° N). A descriptive sensory analysis of broccoli florets was performed by a trained panel to examine any differences along the latitudinal gradient for 30 attributes within appearance, odour, taste/flavour and texture. RESULTS: Average results over three summer seasons in Germany, southern Norway and northern Norway showed that the northernmost location with low temperatures and long days had highest scores for bud coarseness and uniform colour, while broccoli from the German location, with high temperatures and shorter days, had highest intensity of colour hue, whiteness, bitter taste, cabbage flavour, stale flavour and watery flavour. Results from two autumn seasons at the fourth location (42° N, Spain), with low temperatures and short days, tended toward results from the two northernmost locations, with an exception for most texture attributes. CONCLUSION: Results clearly demonstrate that temperature and light conditions related to latitude and season affect the sensory quality of broccoli florets. Results may be used in marketing special quality regional or seasonal products. © 2016 Society of Chemical Industry.


Asunto(s)
Brassica/química , Brassica/efectos de la radiación , Gusto , Altitud , Brassica/crecimiento & desarrollo , Color , Conservación de Alimentos , Alemania , Humanos , Luz , Noruega , Hojas de la Planta/química , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/efectos de la radiación , Temperatura
16.
Br J Nutr ; 115(2): 239-50, 2016 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-26563915

RESUMEN

Sufficient summer/autumn vitamin D status appears important to mitigate winter nadirs at northern latitudes. We conducted a cross-sectional study to evaluate autumn vitamin D status and its determinants in 782 Danish 8-11-year-old children (55°N) using baseline data from the Optimal well-being, development and health for Danish children through a healthy New Nordic Diet (OPUS) School Meal Study, a large randomised controlled trial. Blood samples and demographic and behavioural data, including 7-d dietary recordings, objectively measured physical activity, and time spent outdoors during school hours, were collected during September-November. Mean serum 25-hydroxyvitamin D (25(OH)D) was 60·8 (sd 18·7) nmol/l. Serum 25(OH)D levels ≤50 nmol/l were found in 28·4 % of the children and 2·4 % had concentrations <25 nmol/l. Upon multivariate adjustment, increasing age (per year) (ß -2·9; 95 % CI -5·1, -0·7 nmol/l), female sex (ß -3·3; 95 % CI -5·9, -0·7 nmol/l), sampling in October (ß -5·2; 95 % CI -10·1, -0·4 nmol/l) and November (ß -13·3; 95 % CI -17·7, -9·1), and non-white ethnicity (ß -5·7; 95 % CI -11·1, -0·3 nmol/l) were negatively associated with 25(OH)D (all P<0·05). Likewise, immigrant/descendant background was negatively associated with 25(OH)D, particularly in females (ß -16·3; 95 % CI -21·9, -10·7) (P<0·001) (P interaction=0·003). Moderate-to-vigorous physical activity (MVPA) (min/d) (ß 0·06; 95 % CI 0·01, 0·12), outdoor walking during school hours (min/week) (ß 0·4; 95 % CI 0·1, 0·6) and intake of vitamin D-containing supplements ≥3 d/week (ß 8·7; 95 % CI 6·4, 11·0) were positively associated with 25(OH)D (all P<0·05). The high proportion of children with vitamin D status below the recommended sufficiency level of 50 nmol/l raises concern as levels expectedly drop further during winter months. Frequent intake of vitamin D supplements was strongly associated with status. MVPA and outdoor activity during school hours should be investigated further in interventions to improve autumn vitamin D status in children at northern latitudes.


Asunto(s)
Dieta , Estado de Salud , Instituciones Académicas , Estaciones del Año , Deficiencia de Vitamina D/sangre , Factores de Edad , Animales , Niño , Estudios Transversales , Dinamarca/epidemiología , Suplementos Dietéticos , Etnicidad , Femenino , Peces , Humanos , Masculino , Actividad Motora , Estado Nutricional , Pubertad , Factores Sexuales , Luz Solar , Vitamina D/administración & dosificación , Vitamina D/análogos & derivados , Vitamina D/sangre
17.
Wiad Lek ; 69(3 pt 2): 537-541, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28478422

RESUMEN

INTRODUCTION: cardiovascular impairment remains one of the most current problems of today's life and the definition of the connection between its development and the state of heliogeophysical storminess is currently important. The results of long-term researches of communication between cardiovascular catastrophes (myocardial infarction) and heliogeophysical storminess in the middle and high latitudes are shown in this work. AIM: to study the influence of space weather parameters on human cardio-vascular system in the high and middle latitudes. To define the particular space weather parameters and the mechanisms of their influence on human myocardial infarction progressing. MATERIAL AND METHODS: for the statistical processing of medical records data we use a spectral-time analysis, a correlation method and a method of overlapping of epochs. We have studied about 145 thousand medical records of ambulance medical services for the period of 1992 -2001. In order to define the reasons influencing the development of a myocardial infarction, we have made a comparison of myocardial infarction progress cases with Kp-index characterizing the level of geomagnetic storminess. RESULTS: the coincidence of geomagnetic storminess maximum with the cases of myocardial infarction, as well as the number of heart attacks excess in 1.5 times per a year near the maximum heliogeophysical activity (1992) compared to the year near the minimum of activity (1998) indicate possible influence of geomagnetic storminess on the myocardial infarction development of people living in subauroral latitudes. CONCLUSIONS: it was concluded that the appearance of heliogeophysical storminess in the myocardial infarction development in the mid-latitudes is largely due to the presence of Pc1 geomagnetic pulsations, and in the high latitudes, especially in maximum years of heliogeophysical storminess, it is due to the geomagnetic storminess caused by the parameters of the solar wind and the interplanetary magnetic field.


Asunto(s)
Campos Magnéticos , Infarto del Miocardio/epidemiología , Actividad Solar , Geografía , Corazón , Humanos
18.
Wiad Lek ; 69(3 pt 2): 537-541, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27717941

RESUMEN

INTRODUCTION: cardiovascular impairment remains one of the most current problems of today's life and the definition of the connection between its development and the state of heliogeophysical storminess is currently important. The results of long-term researches of communication between cardiovascular catastrophes (myocardial infarction) and heliogeophysical storminess in the middle and high latitudes are shown in this work. AIM: to study the influence of space weather parameters on human cardio-vascular system in the high and middle latitudes. To define the particular space weather parameters and the mechanisms of their influence on human myocardial infarction progressing. MATERIAL AND METHODS: for the statistical processing of medical records data we use a spectral-time analysis, a correlation method and a method of overlapping of epochs. We have studied about 145 thousand medical records of ambulance medical services for the period of 1992 -2001. In order to define the reasons influencing the development of a myocardial infarction, we have made a comparison of myocardial infarction progress cases with Kp-index characterizing the level of geomagnetic storminess. RESULTS: the coincidence of geomagnetic storminess maximum with the cases of myocardial infarction, as well as the number of heart attacks excess in 1.5 times per a year near the maximum heliogeophysical activity (1992) compared to the year near the minimum of activity (1998) indicate possible influence of geomagnetic storminess on the myocardial infarction development of people living in subauroral latitudes. CONCLUSIONS: it was concluded that the appearance of heliogeophysical storminess in the myocardial infarction development in the mid-latitudes is largely due to the presence of Pc1 geomagnetic pulsations, and in the high latitudes, especially in maximum years of heliogeophysical storminess, it is due to the geomagnetic storminess caused by the parameters of the solar wind and the interplanetary magnetic field.


Asunto(s)
Campos Magnéticos/efectos adversos , Infarto del Miocardio/etiología , Actividad Solar , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
19.
J Hum Evol ; 89: 181-201, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26087650

RESUMEN

When and how humans began to control fire has been a central debate in Paleolithic archaeology for decades. Fire plays an important role in technology, social organization, subsistence, and manipulation of the environment and is widely seen as a necessary adaptation for the colonization of northern latitudes. Many researchers view purported hearths, burnt wooden implements, and heated flints from Schöningen as providing the best evidence for the control of fire in the Lower Paleolithic of Northern Europe. Here we present results of a multianalytical study of the purported hearths along with a critical examination of other possible evidence of human use or control of fire at Schöningen. We conclude that the analyzed features and artifacts present no convincing evidence for human use or control of fire. Our study also shows that a multianalytical, micro-contextual approach is the best methodology for evaluating claims of early evidence of human-controlled fire. We advise caution with macroscopic, qualitative identification of combustion features, burnt flint, and burnt wood without the application of such techniques as micromorphology, Fourier transform infrared (FTIR) spectroscopy, organic petrology, luminescence, and analysis of mineral magnetic parameters. The lack of evidence for the human control of fire at Schöningen raises the possibility that fire control was not a necessary adaptation for the human settlement of northern latitudes in the Lower Paleolithic.


Asunto(s)
Arqueología , Incendios , Sedimentos Geológicos , Alemania , Humanos , Madera
20.
J Hum Evol ; 73: 58-63, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25053189

RESUMEN

The fluvio-lacustrine sequences in the Nihewan Basin, northern China provide an important source of Paleolithic settlements and therefore early human occupation in the eastern Old World. Here we present electron spin resonance (ESR) chronology for the Majuangou (MJG-III, MJG-II and MJG-I) and Banshan (BS) Paleolithic sites in this basin by the quartz Ti-Li center ESR dating. Results show that the ages of MJG-III and MJG-II could be estimated to be ∼1.70 Ma (millions of years ago); of MJG-I, ∼1.40 Ma; and BS, ∼1.35 Ma. This ESR chronology is consistent with the previous magnetochronology, thus providing strong support for the earliest human presence at the high northern latitudes of Northeast Asia.


Asunto(s)
Arqueología , Cronología como Asunto , Hominidae , Animales , China , Espectroscopía de Resonancia por Spin del Electrón
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