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1.
Int J Biometeorol ; 67(3): 465-473, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36652002

RESUMO

The phenological response to climate change differs among species. We examined the beginning of flowering of the common snowdrop (Galanthus nivalis) in connection with meteorological variables in Czechia in the period 1923-2021. The long-term series were analyzed from phenological and meteorological stations of the Czech Hydrometeorological Institute (CHMI). Temporal and spatial evaluation (using Geographic Information System) in timing of beginning of flowering (BBCH 61) of G. nivalis was investigated under urban and rural settings. Furthermore, the detailed analysis of selected meteorological variables to onset of G. nivalis flowering was performed. Moreover, the trends (using Mann-Kendall test) and Pearson's correlation coefficients between phenological phase and meteorological variable were calculated. The main finding of this study was that the trend of the beginning of flowering of the common snowdrop during the studied period (1923-2021) is negative, and it varies in urban and rural environments. The results showed most significant acceleration of the beginning of flowering of G. nivalis by - 0.20 day year-1 in urban area and by - 0.11 day year-1 in rural area. Above that, a major turning point occurred between 1987 and 1988 (both, in phenological observations and meteorological variables), and the variability of the beginning of flowering is significantly higher in the second period 1988-2021. On top of, the study proved that the beginning of flowering of G. nivalis closely correlated with number of days with snow cover above 1 cm (December-March) at both types of stations (urban and rural), and with mean air temperature in February, maximum air temperature in January, and minimum air temperature in March. The Mann-Kendall test showed a reduction in the number of days with snow cover above 1 cm (December-March) during 99 years period at Klatovy station (a long-term time series) by - 0.06 day year-1, i.e., by - 5.94 days per the whole period. Conversely, air temperatures increase (maximum and minimum air temperature by 0.03 °C year-1 (2.97 °C per the whole period) and average air temperature by 0.02 °C year-1 (1.98 °C per the whole period)). Thus, our results indicate significant changes in the beginning of flowering of G. nivalis in Czechia as a consequence of climate change.


Assuntos
Mudança Climática , Biomarcadores Ambientais , República Tcheca , Galanthus , Estações do Ano , Temperatura , Flores
2.
Environ Manage ; 69(1): 128-139, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34453592

RESUMO

As ongoing research efforts contribute to elucidating the consequences of climate change as well as adaptation and mitigation options, aligning the current research knowledge with stakeholder opinions and perceptions remains critical for adopting effective climate change policies. This paper utilizes an interactive survey to (1) address the aforementioned gap in studies involving three groups of stakeholders and opinion makers and (2) perform a comparative primary study of the climate change assumptions, risk perceptions, policy preferences, observations, and knowledge of Czech farmers, governmental policy-makers and researchers. This study shows that the stakeholder groups agree that the climate is clearly changing, attribute this change mostly to man-made causes and expect the negative effects to either prevail or be unevenly geographically distributed. The large majority of all three groups consider unmitigated climate change a major threat even by 2050 and agree that preparing in advance is the best sectoral strategy. Importantly, while investment in adaptation measures is considered the most efficient tool for accelerating the implementation of adaptation measures, the CAP and EU rules (as valid in 2016) are believed to hinder such measures. The results of this study have ramifications for the wider region of Central Europe.


Assuntos
Mudança Climática , Agricultura Florestal , Agricultura/métodos , Consenso , República Tcheca , Humanos , Políticas
3.
Materials (Basel) ; 13(10)2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32443932

RESUMO

Tool steels are used in stamping, shearing processes, and as cutting tools due to their good mechanical properties. During their working cycle, steels are subject to aggressive conditions such as heat stress, fatigue, and wear. In this paper, three tool steels, namely X153CrMoV12, X37CrMoV5-1, and X45NiCrMo4 were selected against two types of bearing balls, ZrO2 and X46Cr1. All measurements were performed on a UMT TriboLab universal tribometric instrument under dry conditions. The main objective of the experiment was to analyze and compare tool steel wear in contact with two kinds of bearing balls with a diameter of 4.76 mm. This evaluation is focused on the hardness, surface roughness, and microstructure of all samples and on the impact of the input parameters on the resulting wear. All three types of tool steels were measured in the basic annealed state and, subsequently, in the state after hardening and tempering. Experimental results show that tool steels, belonging to high strength steels, can successfully represent wear resistant steels. The content of carbide elements, their size, and shape in the microstructure play an important role in the friction process and subsequent wear. Three types of loads were used and compared in the experiments 30, 60, and 90 N. Increasing the load results in significant degradation of the material on the sample surface. Lastly, the impact of hardness and roughness of materials on wear has also been proven. If abrasive wear occurs in the friction process, there is a greater degree of wear than that of adhesive wear. This is due to less abrasive particles, which behave like a cutting wedge and are subject to subsequent deformation strengthening due to the load increase, which adversely affects the further friction process. Analysis of the results showed that the ZrO2 ceramic ball showed significantly better wear values when compared to the X46Cr13 stainless steel ball. It also improves the values of the coefficient of friction with respect to the type of wear that occurs when the experimental materials and counterparts are in contact.

4.
Int J Biometeorol ; 64(5): 791-801, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32006117

RESUMO

This paper analyzes a long-term (1991-2019) flowering period of birch in the Czech Republic. Temporal and spatial evaluation in timing of beginning and end of flowering (Fbegin and Fend) and flowering period (Fperiod) of Betula pendula were investigated in different zones of the Czech Republic. The field observations were carried out at 44 sites of the Czech Hydrometeorological Institute phenological network; the detailed analysis including growing degree days (GDD) evaluation to Fbegin and Fend onsets and time of flowering were made at 9 sites in different altitudes. The trends and Pearson's correlation coefficients between Fbegin (Fend) and GDDs were calculated as well. The timing of both phenological stages showed a significant advance to earlier onsets (e.g., - 7.0 d per decade at Medenec station) and the time of flowering shortens (e.g., - 3.8 d per decade at Rokytnice station). Nevertheless, the most marked shift was observed for mountain area in the north-western and north-eastern part of the Czech Republic. In contrast, the smallest shift was found in the southern part of the Czech Republic. The shift of the GDD values fluctuates from negative to positive values. Pearson's correlation coefficients calculated for both phenophases and period of flowering of Betula pendula showed the highest values in Fperiod (e.g., 0.846 at Modrava station) and in Fend (e.g., 0.711 at Rokytnice station) as well. Thus, our results indicate due to global warming symptoms that birch pollen allergy may appear earlier in the year but for a shorter period.


Assuntos
Betula , Mudança Climática , República Tcheca , Flores , Pólen , Estações do Ano , Temperatura
5.
Glob Chang Biol ; 24(8): 3780-3790, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29691942

RESUMO

Many organisms adjust their reproductive phenology in response to climate change, but phenological sensitivity to temperature may vary between species. For example, resident and migratory birds have vastly different annual cycles, which can cause differential temperature sensitivity at the breeding grounds, and may affect competitive dynamics. Currently, however, adjustment to climate change in resident and migratory birds have been studied separately or at relatively small geographical scales with varying time series durations and methodologies. Here, we studied differential effects of temperature on resident and migratory birds using the mean egg laying initiation dates from 10 European nest box schemes between 1991 and 2015 that had data on at least one resident tit species and at least one migratory flycatcher species. We found that both tits and flycatchers advanced laying in response to spring warming, but resident tit populations advanced more strongly in relation to temperature increases than migratory flycatchers. These different temperature responses have already led to a divergence in laying dates between tits and flycatchers of on average 0.94 days per decade over the current study period. Interestingly, this divergence was stronger at lower latitudes where the interval between tit and flycatcher phenology is smaller and winter conditions can be considered more favorable for resident birds. This could indicate that phenological adjustment to climate change by flycatchers is increasingly hampered by competition with resident species. Indeed, we found that tit laying date had an additional effect on flycatcher laying date after controlling for temperature, and this effect was strongest in areas with the shortest interval between both species groups. Combined, our results suggest that the differential effect of climate change on species groups with overlapping breeding ecology affects the phenological interval between them, potentially affecting interspecific interactions.


Assuntos
Migração Animal/fisiologia , Mudança Climática , Comportamento de Nidação/fisiologia , Passeriformes/fisiologia , Animais , Europa (Continente) , Passeriformes/classificação , Reprodução , Estações do Ano , Temperatura
6.
Acta Medica (Hradec Kralove) ; 60(1): 27-31, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28467299

RESUMO

Crude coal tar (CCT) contains polycyclic aromatic hydrocarbons (PAHs). Benzo[a]pyrene (BaP) is metabolized into a highly reactive metabolite benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) that is able to bind to DNA and creates BPDE-DNA adducts. Adducted DNA becomes immunogenic and induces immune response by production of antibodies against BPDE-DNA adducts (Ab-BPDE-DNA). Circulating Ab-BPDE-DNA was proposed as potential biomarker of genotoxic exposure to BaP (PAHs). Goeckerman therapy (GT) of psoriasis uses dermal application of CCT ointment (PAHs). In presented study (children with psoriasis treated by GT; n = 19) the therapy significantly increased the level of Ab-BPDE-DNA (EI = 0.29/0.19-0.34 vs. 0.31/0.25-0.40; median/lower-upper quartile; p < 0.01). The results support the idea of Ab-BPDE-DNA level as a possible tentative indicator of exposure, effects and susceptibility of the organism to the exposure of BaP (PAHs).


Assuntos
7,8-Di-Hidro-7,8-Di-Hidroxibenzo(a)pireno 9,10-óxido/análise , Alcatrão/efeitos adversos , Adutos de DNA/sangue , Ceratolíticos/administração & dosagem , Psoríase/tratamento farmacológico , Criança , Pré-Escolar , Alcatrão/uso terapêutico , Adutos de DNA/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Humanos , Ceratolíticos/uso terapêutico
7.
Int J Biometeorol ; 58(5): 809-17, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23640249

RESUMO

The phenological responses to climate of residents and migrants (short- and long-distance) differ. Although few previous studies have focussed on this topic, the agree that changes in phenology are more apparent for residents than for long-distance migrants. We analysed the breeding times of two selected residents (Sitta europaea, Parus major) and one long-distance migrant (Ficedula albicollis) from 1961 to 2007 in central Europe. The timing of the phenophases of all three bird species showed a significant advance to earlier times. Nevertheless, the most marked shift was observed for the long-distance migrant (1.9 days per decade on average in mean laying date with linearity at the 99.9% confidence level). In contrast, the shifts shown by the residents were smaller (1.6 days for S. europaea and 1.5 days for P. major also on average in mean laying date for both, with linearity at the 95% confidence level). Spearman rank correlation coefficients calculated for pairs of phenophases of given bird species in 20-year subsamples (e.g. 1961-1980, 1962-1981) showed higher phenological separation between the residents and the migrant. This separation is most apparent after the 1980s. Thus, our results indicate that the interconnections between the studied phenological stages of the three bird species are becoming weaker.


Assuntos
Passeriformes/fisiologia , Reprodução , Migração Animal , Animais , Europa (Continente) , Estações do Ano , Temperatura
8.
Clin Appl Thromb Hemost ; 19(4): 395-401, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22431856

RESUMO

INTRODUCTION: Sticky platelet syndrome (SPS) is most likely a hereditary thrombophilia characterized by platelet hyperaggregation after low concentrations of platelet inducers--adenosine diphosphate and/or epinephrine. We present 9 kindreds with SPS familial occurrence. MATERIAL AND METHODS: Familial trait of SPS was looked up in the database of the National Center of Hemostasis and Thrombosis. Families with at least 3 SPS-positive members were studied, described, and presented. RESULTS: In the group of 1093 symptomatic patients, SPS was confirmed in 240 cases. Familial occurrence with at least 3 SPS-positive relatives was found in 9 cases. CONCLUSION: The exact pathogenesis of SPS is not sufficiently explained. Our findings seem to support the idea that SPS might have an autosomal dominant hereditary fashion.


Assuntos
Transtornos Plaquetários/genética , Trombofilia/genética , Adolescente , Adulto , Pré-Escolar , Saúde da Família , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Síndrome , Adulto Jovem
9.
Fertil Steril ; 98(5): 1170-4, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22901851

RESUMO

OBJECTIVE: To evaluate the GP6 gene polymorphism in patients with sticky platelet syndrome (SPS) and fetal loss. DESIGN: Genetic association study. SETTING: Perinatal center. PATIENT(S): Twenty-seven patients with SPS, manifested as fetal loss, and 42 control subjects without SPS and no history of fetal loss and thrombosis. INTERVENTION(S): SPS was diagnosed by platelet aggregometry (PACKS-4 aggregometer; Helena Laboratories). Seven single-nucleotide polymorphisms (SNPs) of the GP6 gene were evaluated. MAIN OUTCOME MEASURE(S): Occurrence of SNPs of the GP6 gene in SPS patients versus control subjects. RESULT(S): We found a higher occurrence of three SNPs of the GP6 gene in SPS patients versus control subjects (rs1671153: 0.204 vs. 0.048, odds ratio [OR] 5.116, 95% confidence interval [CI] 1.536-17.03; rs1654419: 0.204 vs. 0.071, OR 3.326, 95% CI 1.149-9.619; rs1613662: 0.204 vs. 0.071, OR 3.326, 95% CI 1.149-9.619). The haplotype analysis showed a significantly higher occurrence of two haplotypes (CTGAG in haplotype 5: 0.185 vs. 0.059, OR 3.568, 95% CI 1.142-11.14; and CGATAG in haplotype 6: 0.204 vs. 0.048, OR 4.961, 95% CI 1.488-16.53). CONCLUSION(S): Our results, especially the higher occurrence of haplotypes CTGAG and CGATAG in SPS patients, support the idea that GP6 gene polymorphism may be associated with platelet hyperaggregability, a possible cause of fetal loss.


Assuntos
Aborto Espontâneo/sangue , Aborto Espontâneo/genética , Transtornos Plaquetários/sangue , Transtornos Plaquetários/genética , Agregação Plaquetária/genética , Glicoproteínas da Membrana de Plaquetas/genética , Polimorfismo de Nucleotídeo Único , Aborto Habitual/sangue , Aborto Habitual/genética , Adulto , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Idade Gestacional , Haplótipos , Humanos , Pessoa de Meia-Idade , Razão de Chances , Fenótipo , Testes de Função Plaquetária , Gravidez , Medição de Risco , Fatores de Risco , Eslováquia , Adulto Jovem
11.
Int J Biometeorol ; 54(1): 99-111, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20099374

RESUMO

This study is based on 47 years of observations (1961-2007) on two common bird species, the Great Tit (Parus major) and the Collared Flycatcher (Ficedula albicollis), and a dominant tree species in their habitat, the English Oak (Quercus robur). The study took place at four research sites in the Czech Republic located in full-grown, multi-aged floodplain forests with no forestry management. An increase in air temperature over the evaluated period clearly influenced the length of phenological phases. The full foliage date of English Oak has advanced by 8.7 days during the past 47 years. Great Tit and Collared Flycatcher populations have reacted to the changing climate in the same way, with first laying date and mean laying date advancing by between 6.0 and 9.0 days. In all cases, the trends are highly significant and consistent over all sites. Despite the ongoing shift in phenological stages toward the beginning of the year, the change does not appear to have led to mistiming in the trophic food chain. Overall, this study shows almost identical rates of change in egg laying dates for both bird species in all the floodplain forests studied, and these trends are coherent with those of English Oak and peak herbivorous caterpillar activity.


Assuntos
Migração Animal/fisiologia , Aves/fisiologia , Mudança Climática/estatística & dados numéricos , Ecossistema , Dinâmica Populacional , Comportamento Sexual Animal/fisiologia , Árvores , Animais , Simulação por Computador , República Tcheca , Modelos Estatísticos , Temperatura
12.
Clin Appl Thromb Hemost ; 16(6): 701-4, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19696043

RESUMO

The aim of this study was to detect the prevalence of the polymorphisms of growth arrest-specific gene 6 (Gas6; Gas6 c. 834 + 7G > A) in patients with sticky platelet syndrome (SPS). Sticky platelet syndrome is a hereditary, autosomal dominant thrombophilia characterized by platelet hyperaggregation after low concentrations of platelet inducers-adenosine diphosphate (ADP) and epinephrine (EPI). The cause of SPS still remains unknown, but in recent years it was suggested that Gas6 protein may have a potential role in the pathogenesis of SPS. To assess the Gas6 polymorphisms (Gas6 c. 834 + 7G > A), 128 patients with SPS were included in the study and examined by polymerase chain reaction (PCR) method. GG genotype was detected in 63 (49.2%) patients, GA genotype in 53 (41.4%) patients, and AA genotype in 12 (9.4%) patients. The results in controls did not differ significantly compared to patients with SPS. Our findings did not prove allele A to be less associated with thrombosis and that ''prothrombotic'' allele G may be associated with higher risk of thrombosis. We cannot support the idea that Gas6 protein and Gas6 polymorphisms may be associated with thrombosis in SPS.


Assuntos
Arteriopatias Oclusivas/genética , Transtornos Plaquetários/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Adulto , Arteriopatias Oclusivas/sangue , Transtornos Plaquetários/sangue , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Variação Genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/genética , Polimorfismo de Nucleotídeo Único , Síndrome
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