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1.
Climate variability greatly affects animals through direct and indirect effects. Animals with slow reproductive adaptation to ecological changes such as large mammals are likely to have evolved mechanisms to anticipate early such impacts of climate variability on the environment. One of the adaptive mechanisms between reproductive costs and benefits in mammals affects parental investment through biases in sex ratio. Deer might be likely to show an early detection of climate variability because conception takes place in early autumn, but the main raising cost in deer concerns lactation, which takes place at the end of the following spring. The aim of this paper is to assess whether there is a relationship between global indices of climate variability such as El Niño-Southern Oscillation (ENSO) and sex ratio of a captive population of deer. Results showed that there was a negative correlation (r=?0.65) between sex ratio and ENSO indices between 1996 and 2008. El Niño enhances drier conditions during the summer in the Iberia Peninsula, which in turn favours a female bias. Results also suggest that the mechanism of early detection of climate variability exerts a strong effect on female reproductive physiology because the long-term stability of food resources in our setting has not markedly reduced it.  相似文献   

2.
BackgroundAnnually 125 million pregnancies are at risk of malaria infection. However, the impact of exposure to malaria in pregnancy on neurodevelopment in children is not well understood. We hypothesized that malaria in pregnancy and associated maternal immune activation result in neurodevelopmental delay in exposed offspring.Methods and findingsBetween April 2014 and April 2015, we followed 421 Malawian mother–baby dyads (median [IQR] maternal age: 21 [19, 28] years) who were previously enrolled (median [IQR] gestational age at enrollment: 19.7 [17.9, 22.1] weeks) in a randomized controlled malaria prevention trial with 5 or 6 scheduled assessments of antenatal malaria infection by PCR. Children were evaluated at 12, 18, and/or 24 months of age with cognitive tests previously validated in Malawi: the Malawi Developmental Assessment Tool (MDAT) and the MacArthur–Bates Communicative Development Inventories (MCAB-CDI). We assessed the impact of antenatal malaria (n [%] positive: 240 [57.3]), placental malaria (n [%] positive: 112 [29.6]), and maternal immune activation on neurocognitive development in children. Linear mixed-effects analysis showed that children exposed to antenatal malaria between 33 and 37 weeks gestation had delayed language development across the 2-year follow-up, as measured by MCAB-CDI (adjusted beta estimate [95% CI], −7.53 [−13.04, −2.02], p = 0.008). Maternal immune activation, characterized by increased maternal sTNFRII concentration, between 33 and 37 weeks was associated with lower MCAB-CDI language score (adjusted beta estimate [95% CI], −8.57 [−13.09, −4.06], p < 0.001). Main limitations of this study include a relatively short length of follow-up and a potential for residual confounding that is characteristic of observational studies.ConclusionsThis mother–baby cohort presents evidence of a relationship between malaria in pregnancy and neurodevelopmental delay in offspring. Malaria in pregnancy may be a modifiable risk factor for neurodevelopmental injury independent of birth weight or prematurity. Successful interventions to prevent malaria during pregnancy may reduce the risk of neurocognitive delay in children.

Andrea Weckman and co-workers study associations between children’s neurodevelopmental outcomes and malaria in pregnancy.  相似文献   

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4.

Key message

Clim ate is the main driver of Aleppo pine radial growth variability irrespective of site pro ductivity, with the climate effects on tree growth more limiting from 1970 onwards.

Abstract

Forest management adaptation to climate change requires identifying the previously most vulnerable stands and the possible climate impacts on forests. This study evaluates whether site index, as an indicator of forest productivity, is related to climate–growth responses and assesses the way in which local site factors modulate climate–tree growth relationships. Tree-ring width series and soil characteristics were obtained from six Pinus halepensis stands with different site indices and similar climate. Dendrochronological methods were used to compare tree climate–growth responses among sites and to study temporal trends in inter-annual growth variability and climate–growth relationships (before and after 1970). The influence of topographic and soil features on tree growth was assessed by means of partial least squares. Stands with low site indices tended to present higher mean sensitivities and greater percentages of missing rings, this relation being modulated mainly by clay percentage and nutrient status in soil. Climate is the major Aleppo pine radial growth driver in the study area with similar growth–climate relationship among sites. Radial growth was mainly influenced by spring temperature and precipitation and previous autumn–winter precipitation. This relationship was stronger after 1970 than before this year, showing also a 2-month advancement of the most influential climate variables after 1970, from May to March. These results and the increasing temporal trend found in mean sensitivity after 1970 highlight the vulnerability of these stands to climate change. Site index was not found to be directly related to stand vulnerability, although local site factors modulate in part the tree-growth response.  相似文献   

5.

Background

Infants of mothers with placental Plasmodium falciparum infections at delivery are themselves more susceptible to malaria attacks or to infection in early life.

Methodology/ Principal Findings

To assess the impact of either the timing or the number of pregnancy-associated malaria (PAM) infections on the incidence of parasitemia or malaria attacks in infancy, we followed 218 mothers through pregnancy (monthly visits) up to delivery and their infants from birth to 12 months of age (fortnightly visits), collecting detailed clinical and parasitological data. After adjustment on location, mother’s age, birth season, bed net use, and placental malaria, infants born to a mother with PAM during the third trimester of pregnancy had a significantly increased risk of infection (OR [95% CI]: 4.2 [1.6; 10.5], p = 0.003) or of malaria attack (4.6 [1.7; 12.5], p = 0.003). PAM during the first and second trimesters had no such impact. Similarly significant results were found for the effect of the overall number of PAM episodes on the time to first parasitemia and first malaria attack (HR [95% CI]: 2.95 [1.58; 5.50], p = 0.001 and 3.19 [1.59; 6.38], p = 0.001) respectively.

Conclusions/ Significance

This study highlights the importance of protecting newborns by preventing repeated episodes of PAM in their mothers.  相似文献   

6.
Severe malaria and viral infections cause life-threatening diseases in millions of people worldwide every year. In search for effective bioactive hybrid molecules, which may possess improved properties compared to their parent compounds, a series of betulinic acid/betulin based dimer and hybrid compounds carrying ferrocene and/or artesunic acid moieties, was designed and, synthesized de novo. Furthermore, they were analyzed in vitro against malaria parasites (growth inhibition of 3D7-strain P. falciparum-infected erythrocytes) and human cytomegalovirus (HCMV). From this series of hybrids/dimers, the betulinic acid/betulin and artesunic acid hybrids 11 and 12 showed the most potent activities against P. falciparum and HCMV. On the strength of results, additive and/or synergistic effects between the natural or semisynthetic products, such as betulinic acid-/betulin- and artesunic acid-derived compounds, are suggested on the basis of putatively complex modes of antimicrobial action. This advantage may be taken into account in future drug development.  相似文献   

7.
Methyl 2-O-benzoyl-3-bromo-3,6-dideoxy-α-l-altropyranoside (4) and methyl 2-O-benzoy]-3-bromo-3,6-dideoxy-4-O-methyl-α-l-altropyranoside (5) have been prepared from methyl-α-l-rhamnopyranoside, respectively, in 2 and 3 steps. Reduction of 4 with lithium aluminium hydride followed by acid hydrolysis afforded the 3,6-dideoxy-l-arabino-bexose (l-ascarylose). The anhydro sugars 8 and 9 have been used as intermediates in the stereoselective synthesis of 6-deoxy-3-O-methyl-l-altropyranose (l-vallarose) and of 3-amino-3-degxy-l-altro sugars. Under azidolysis conditions, and according to the temperature, 5 gave unsaturated sugars such as 20 and the derived 26, or azido compounds such as 21 and 24, and the derived sugar methyl 2-amino-2,3,6-trideoxy-α-l-threo-hexopyranosid-4-ulose (25).  相似文献   

8.
By further optimizing compound A [2′-fluoro-N-methyl-[1,1′-biphenyl]-2-sulfonamide], we identified DSP-0565 [2-(2′-fluoro-[1,1′-biphenyl]-2-yl)acetamide, 17a] as a strong, broad-spectrum anti-epileptic drug (AED) candidate. Our efforts mainly focused on finding an alternative polar group for the sulfonamide in order to improve ADME profile of compound A including good metabolic stability and no reactive metabolic production. This led to the identification of biphenyl acetamide as a new scaffold for development of broad-spectrum AED candidates. DSP-0565 showed anti-convulsant activity in various models (scPTZ, MES, 6?Hz and amygdala kindling) with good safety margin, and was therefore selected as a clinical candidate.  相似文献   

9.
《Endocrine practice》2016,22(10):1177-1186
Objective: Intravenous (iv) glucocorticoids (GC) (ivGC) are used for active Graves orbitopathy (GO), but factors affecting GO outcome are poorly understood. We performed a retrospective study to investigate the variables affecting GO after ivGC.Methods: We evaluated 83 consecutive GO patients treated with ivGC but not orbital radiotherapy (ORT) and re-examined them after a median of 47 months. The endpoints were the relationships between GO outcome or additional treatments with age, sex, smoking habits, thyroid volume, thyroid treatment, time since thyroid treatment, antithyroid-stimulating hormone receptor antibodies (TRAb), GO duration, GO features, and follow-up time.Results: GO features improved after treatment, resulting in moderate and marked amelioration in ~75% and ~41% of patients respectively. By multivariate analysis, a moderate GO improvement correlated with diplopia at first observation, which was more severe in responders. A marked GO improvement correlated with time between first and last observation and time after thyroid treatment, which were longer in responders. This likely reflected the combination of an early effect of GC and a late, spontaneous improvement of GO, as shown by analyses of GO outcome at various time points. Additional treatments after ivGC correlated by multivariate analysis with eyelid aperture, diplopia and NOSPECS score (NOSPECS stands for no GO signs [N], only eyelid sign [O], soft tissue involvement [S], proptosis [P], extraocular motility restriction [E], corneal involvement [C], and sight loss [S]) at first observation, which were more severe in responders.Conclusion: Our study shows that response to ivGC increases with time, likely reflecting the known tendency of GO to improve spontaneously, and is more pronounced when GO is more severe to begin with, which is associated with more additional treatments.Abbreviations:ANOVA = analysis of varianceCAS = clinical activity scoreGC = glucocorticoidsGO = Graves orbitopathy131I = radioactive iodineiv = intravenousivGC = high-dose intravenous glucocorticoid pulse therapyMMI = methimazoleOD = orbital decompressionORT = orbital radiotherapyTRAb = antithyroid-stimulating hormone receptor antibodies  相似文献   

10.
Based on the structure of YO-2 [N-(trans-4-aminomethylcyclohexanecarbonyl)-l-Tyr(O-picolyl)-NH-octyl], active site-directed plasmin (Plm) inhibitors were explored. The picolyl moiety in the Tyr(O-picolyl) residue (namely, the P2 residue) was replaced with smaller or larger groups, such as hydrogen, tert-butyl, benzyl, (2-naphthyl)methyl, and (quinolin-2-yl)methyl. Those efforts produced compound 17 {N-(trans-4-aminomethylcyclohexanecarbonyl)-l-Tyr[O-(quinolin-2-yl)methyl]-NH-octyl} [IC50 = 0.22 and 77 μM for Plm and urokinase (UK), respectively], which showed not only 2.4-fold greater Plm inhibition than YO-2, but also an improvement in selectivity (Plm/UK) by 35-fold. The docking experiments of the Plm-17 complexes disclosed that the amino group of the tranexamyl moiety interacted with the side-chain of Asp753 which formed S1 site.  相似文献   

11.
《Endocrine practice》2016,22(7):842-884
Objective: Development of these guidelines is mandated by the American Association of Clinical Endocrinologists (AACE) Board of Directors and the American College of Endocrinology (ACE) Board of Trustees and adheres to published AACE protocols for the standardized production of clinical practice guidelines (CPGs).Methods: Recommendations are based on diligent review of clinical evidence with transparent incorporation of subjective factors.Results: There are 9 broad clinical questions with 123 recommendation numbers that include 160 specific statements (85 [53.1%] strong [Grade A], 48 [30.0%] intermediate [Grade B], and 11 [6.9%] weak [Grade C], with 16 [10.0%] based on expert opinion [Grade D]) that build a comprehensive medical care plan for obesity. There were 133 (83.1%) statements based on strong (best evidence level [BEL] 1 = 79 [49.4%]) or intermediate (BEL 2 = 54 [33.7%]) levels of scientific substantiation. There were 34 (23.6%) evidence-based recommendation grades (Grades A-C = 144) that were adjusted based on subjective factors. Among the 1,788 reference citations used in this CPG, 524 (29.3%) were based on strong (evidence level [EL] 1), 605 (33.8%) were based on intermediate (EL 2), and 308 (17.2%) were based on weak (EL 3) scientific studies, with 351 (19.6%) based on reviews and opinions (EL 4).Conclusion: The final recommendations recognize that obesity is a complex, adiposity-based chronic disease, where management targets both weight-related complications and adiposity to improve overall health and quality of life. The detailed evidence-based recommendations allow for nuanced clinical decision-making that addresses real-world medical care of patients with obesity, including screening, diagnosis, evaluation, selection of therapy, treatment goals, and individualization of care. The goal is to facilitate high-quality care of patients with obesity and provide a rational, scientific approach to management that optimizes health outcomes and safety.Abbreviations:A1C = hemoglobin A1cAACE = American Association of Clinical EndocrinologistsACE = American College of EndocrinologyAMA = American Medical AssociationBEL = best evidence levelBMI = body mass indexCCO = Consensus Conference on ObesityCPG = clinical practice guidelineCSS = cross-sectional studyCVD = cardiovascular diseaseEL = evidence levelFDA = Food and Drug AdministrationGERD = gastroesophageal reflux diseaseHDL-c = high-density lipoprotein cholesterolIFG = impaired fasting glucoseIGT = impaired glucose toleranceLDL-c = low-density lipoprotein cholesterolMNRCT = meta-analysis of non-randomized prospective or case-controlled trialsNE = no evidencePCOS = polycystic ovary syndromeRCT = randomized controlled trialSS = surveillance studyU.S = United States  相似文献   

12.
13.
Climate change will lead to changes in both the mean and variability of a number of different climatic variables. Temperature is one of these. Poikilotherms are organisms whose development rate at each life stage is dictated by temperature, and so we anticipate that climate change will have strong effects on the dynamics of these organisms. In this paper, we use a mathematical model for development that explicitly includes temperature dependence to investigate the effect of four different types of thermal perturbations: (1) increased mean annual temperature, increased swings in (2) annual and (3) daily temperatures, and (4) extreme temperature events. We investigate these effects in the context of three different poikilotherms, two biocontrol agents (Neoseiulus californicus and Mecinus janthiniformis) and a native forest pest (the mountain pine beetle, Dendroctonus ponderosae). We find that the three organisms respond very differently to the thermal perturbations, indicating that the impact of climate change on poikilotherms is not straightforward and potentially highly complex.  相似文献   

14.
A major challenge in the fight to effectively control malaria is the emergence of resistant parasite to drugs used in therapy as well as for chemoprevention. In this study, single nucleotide polymorphisms (SNPs) associated with Plasmodium falciparum resistance to sulfadoxine-pyrimethamine (SP), one of the partner drugs in artemisinin-based therapies (ACTs) were studied in asymptomatic P. falciparum isolates from Cameroon. Dried Blood spots were collected from children with asymptomatic malaria enrolled during a household survey. The P. falciparum dihydrofolate reductase (Pfdhfr), dihydropteroate synthase (Pfdhps) and Kelch 13 genes were amplified and point mutations in these gene sequences were analyzed by sequencing. Among a total of 234 samples collected, 51 showed parasitaemia after microscopic examination of which 47 were P. falciparum mono-infections. Molecular analysis revealed 97.3% of mutant alleles at codons 51I, 59R and 108 N in Pfdhfr gene. In Pfdhps gene the most common mutation was 437G (83.3%); followed by 436A (47.6%) and 436F (28.6%). The association of mutations in the two genes (dhfr + dhps) showed 11 different haplotypes including three sextuple mutants (IRNI + AGKGA, IRNI + AAKGS, IRNI + AGKAS) and one septuple mutant (IRNI + AGKGS). For K13 gene no SNPs were seen in the studied asymptomatic malaria samples. The findings revealed presence of SP-resistant alleles in asymptomatic infected individuals with presence of sextuples and septuple SNPs. This emphasizes that regular profiling of antimalarial drugs resistance markers in such population is essential for malaria control and elimination programmes.  相似文献   

15.
《Insect Biochemistry》1990,20(6):567-572
Males of the cucujid grain beetles, Cryptolestes ferrugineus (Stephens), C. pusillus (Schönhen), C. turcicus (Grouvelle), Oryzaephilus mercator (Fauval) and O. surinamensis (L.), produce seven structurally related macrolides (“cucujolides”). Species-specific combinations of these macrocyclic lactones function as aggregation pheromones. To study the biosynthesis of these cucujolides, mixed sex cultures of the rusty grain beetle, C. ferrugineus, were fed oats impregnated with radiolabelled substrates. Culture volatiles were trapped on Porapak Q, eluted by back-flushing with solvent, concentrated and purified to constant specific activity by high performance liquid chromatography and preparative gas chromatography. The incorporation of radiolabelled acetate and mevalonate into cucujolide I [4(E),8(E)4,8-dimethyldecadien-10-olide] provided evidence that this pheromone is of terpenoid origin. The efficient incorporation of radiolabelled fatty acid substrates into cucujolides II 3(Z)dodecen-11-olide], III 5(Z)tetradecen-13-olide], IV [3(Z),6(Z)dodecadien-11-olide] and V [5(Z),8(Z)tetradecadien-13-olide] provided evidence that these cucujolides are of fatty acid origin. Radiolabelled palmitic acid was incorporated into cucujolides II, III, IV and V; radiolabelled oleic acid was incorporated into II and III; and radiolabelled linoleic acid was incorporated into IV. Radiolabelled acetate was incorporated into cucujolides II, III and V, indicating that C. ferrugineus can produce these cucujolides de novo.  相似文献   

16.
Background: Lungs are exposed to high levels of oxygen, air pollutants, and smoke, all of which stimulate the production of reactive oxygen species (ROS). In addition, inflammatory cells produce ROS, and thus there may be increased demand for antioxidants, including antioxidant enzymes, in inflammatory lung diseases such as asthma. Sex-specific differences have been noted for asthma, which in postpubertal subjects is predominantly found in females. These sex-specific differences may be associated with differences on the molecular level as well.Objective: The aim of this cross-sectional study was to examine associations between markers of antioxidative defense and asthma, and to investigate whether these associations were different between women and men.Methods: Based on the European Community Respiratory Health Survey protocol, subjects were enrolled in a study of asthma risk factors. The multicenter study was conducted in 5 west Danish counties between 2003 and 2006, and the subjects were recruited as a case-enriched random sample of 10,000 Danish inhabitants aged 20 to 44 years selected by their civil registration number. Participants were identified by positive answers to asthma questions on a screening questionnaire, random sampling, or both. Serum selenium concentrations and antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase [GPX], glutathione reductase [GR], and glucose-6-phosphate dehydrogenase [G6PD]) in erythrocytes were measured. Asthma was defined as either current asthma symptoms with bronchial hyperresponsiveness (BHR) or a continuous asthma score based on 8 questions.Results: A total of 1191 mostly white women and men (mean [SD] age, 34.0 [7.1] and 35.1 [7.1] years, respectively) were enrolled in the study. Current asthma symptoms were present in 29.9% (200/670) of women and 22.5% (117/521) of men, with women reporting more positive answers (51.1% vs 40.9%, respectively; P < 0.01) to asthma questions. Serum selenium concentrations were measured in 1151 subjects (640 women, 511 men), and antioxidant enzyme activities were measured in 295 subjects (161 women, 134 men). Women had higher enzyme activities of most antioxidant enzymes (GPX, P = 0.006; GR, P < 0.001; and G6PD, P = 0.009) than did men. Although the serum selenium concentration was inversely associated with asthma in both sexes, there was a female preponderance, with 3.5% lower serum selenium in subjects with current asthma symptoms with BHR (n = 77) compared with controls (n = 287). GR activity was associated with asthma in men, with 5.7% higher enzyme activity in subjects with current asthma symptoms with BHR (n = 14) compared with controls (n = 77). However, a significant interaction with gender was observed for analyses of GR (P = 0.02), but not for analyses of selenium.Conclusions: In this study of asthma risk factors, women had higher levels of enzyme activities than did men in a randomly selected Danish population, and sex-specific differences were found in the associations between markers of antioxidative defense and asthma.  相似文献   

17.
Chevalierinosides B (1) and C (2), two new isoflavonoid glycosides, characterized as biochanin A 7-O-[β-d-apiofuranosyl-(1→2)-β-d-glucopyranoside] and genistein 7-O-[β-d-apiofuranosyl-(1→2)-β-d-glucopyranoside], together with the known isoflavonoids, chevalierinoside A (3) and genistein 7-O-β-d-glucopyranoside (4), kaempferol 3-O-β-d-glucopyranoside (5) and triterpenes, friedelin (6), betulinic acid (7), 30-oxobetulinic acid (8), 30-hydroxybetulinic acid (9), were isolated from the stem bark of Antidesma laciniatum Muell. Arg. (syn. Antidesma chevalieri Beille). Their structures were established by direct interpretation of their spectral data, mainly HR-TOFESIMS, 1D-NMR (1H, 13C and DEPT) and 2D-NMR (COSY, NOESY, TOCSY, HSQC and HMBC), and by comparison with the literature.  相似文献   

18.
A series of thymol based substituted pyrazolines and chalcones was synthesized and evaluated for antimalarial activity, using in-vitro and in-vivo malaria models. All the target compounds (5a-k and 6a-j) were found to be active against human malaria parasite strain Plasmodium falciparum NF54. Among all, compounds 5e and 5f of chalcone series and 6c and 6f of pyrazoline series exhibited prominent antimalarial activity with IC50 less than 3 and 2 μM respectively, while other pyrazolines also significantly inhibited the P. falciparum with IC50 less than 10 μM. The designed pharmacophores were found to be effective against P. falciparum. Compound 6f was found to be able to retard malaria progression in mice. This was evident through decreased parasitemia, increased mean survival time and hemoglobin content in the treated animals. Moreover, 6f was observed as an inhibitor of heme polymerization pathway of the malaria parasite. It also inhibited free heme degradation, which could be possibly responsible for higher reactive oxygen species (ROS) in parasite, thus inhibiting the rapid proliferation of the parasite. In addition to this, compound 6f was found to be non-toxic with a good selectivity index. Based on these observations, the compound 6f could be taken up for further antimalarial lead optimization studies.  相似文献   

19.
《Gender Medicine》2007,4(3):205-213
Background: In a range of chronic conditions including diabetes, it has been observed that depressive symptoms may be associated with nonadherence to medications.Objective: The objective of the study was to determine the main effects, and interactive effect, of depression and gender on patients adherence to oral diabetes medications.Methods: A cross-sectional design was employed, in which persons with type 2 diabetes mellitus completed a questionnaire regarding medication use behaviors, depressive symptoms (measured by the 8-item Patient Health Questionnaire [PHQ-8]), health beliefs, and demographics. A 2 x 2 factorial analysis of variance was used to determine the effects of gender and depression on medication adherence after adjusting for age, education, self efficacy, social support, and number of doses of diabetes medications.Results: Of the 391 respondents who completed the questionnaire, 73 (18.7%) were categorized as having depression (ie, PHQ-8 score >10). Overall, women (n = 196) had a mean (SD) score of 6.10 (6.19) on the PHQ-8, and men (n = 195) had a lower score of 4.62 (5.28) (t = 2.75; P < 0.01). There was a significant main effect of depression, but not gender, on patients' adherence to diabetes medications in that those who were categorized as depressed had significantly worse adherence to diabetes medications (F = 4.82; P = 0.03).Additionally, there was a significant “gender x depression” interaction effect on adherence (F = 5.93; P = 0.01). Men with depression had mean adherence scores that indicated more nonadherence than did men without depression (9.44 [3.45] vs 7.47 [2.50], respectively), but adherence varied little between women with depression and women without depression (7.83 [2.69] vs 7.55 [2.58], respectively).Conclusions: The association between depression and medication adherence appears to be stronger in men than in women. Clinicians should be cognizant of the potential effect of depression on self-care for diabetes, particularly in men with depressive symptoms.  相似文献   

20.
Understanding relations between climate and pollen production is important for several societal and ecological challenges, importantly pollen forecasting for pollinosis treatment, forensic studies, global change biology, and high-resolution palaeoecological studies of past vegetation and climate fluctuations. For these purposes, we investigate the role of climate variables on annual-scale variations in pollen influx, test the regional consistency of observed patterns, and evaluate the potential to reconstruct high-frequency signals from sediment archives. A 43-year pollen-trap record from the Netherlands is used to investigate relations between annual pollen influx, climate variables (monthly and seasonal temperature and precipitation values), and the North Atlantic Oscillation climate index. Spearman rank correlation analysis shows that specifically in Alnus, Betula, Corylus, Fraxinus, Quercus and Plantago both temperature in the year prior to (T-1), as well as in the growing season (T), are highly significant factors (TApril rs between 0.30 [P<0.05[ and 0.58 [P<0.0001]; TJuli-1 rs between 0.32 [P<0.05[ and 0.56 [P<0.0001]) in the annual pollen influx of wind-pollinated plants. Total annual pollen prediction models based on multiple climate variables yield R2 between 0.38 and 0.62 (P<0.0001). The effect of precipitation is minimal. A second trapping station in the SE Netherlands, shows consistent trends and annual variability, suggesting the climate factors are regionally relevant. Summer temperature is thought to influence the formation of reproductive structures, while temperature during the flowering season influences pollen release. This study provides a first predictive model for seasonal pollen forecasting, and also aides forensic studies. Furthermore, variations in pollen accumulation rates from a sub-fossil peat deposit are comparable with the pollen trap data. This suggests that high frequency variability pollen records from natural archives reflect annual past climate variability, and can be used in palaeoecological and -climatological studies to bridge between population- and species-scale responses to climate forcing.  相似文献   

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