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THE MONTHLY RAINFALL IN THE RIO DE JANEIRO STATE, BRAZIL: SEASONALITY AND TREND

ARAUJO, Mirian Fernandes Carvalho; GUIMARAES, Ednaldo Carvalho; CARVALHO, Daniel Fonseca de; ARAUJO, Lucio Borges de
Fonte: UNIV FEDERAL UBERLANDIA Publicador: UNIV FEDERAL UBERLANDIA
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
27.06%
The objective of this work was to carry a descriptive analysis in the monthly precipitation of rainfall stations from Rio de Janeiro State, Brazil, using data of position and dispersion and graphical analyses, and to verify the presence of seasonality and trend in these data, with a study about the application of models of time series. The descriptive statistics was to characterize the general behavior of the series in three stations selected which present consistent historical series. The methodology of analysis of variance in randomized blocks and the determination of models of multiple linear regression, considering years and months as predictors variables, disclosed the presence of seasonality, what allowed to infer on the occurrence of repetitive natural phenomena throughout the time and absence of trend in the data. It was applied the methodology of multiple linear regression to removal the seasonality of these time series. The original data had been deducted from the estimates made by the adjusted model and the analysis of variance in randomized blocks for the residues of regression was preceded again. With the results obtained it was possible to conclude that the monthly rainfall present seasonality and they don`t present trend...

Os impactos da sazonalidade no turismo em empresas familiares : o caso da Ilha Terceira, Açores

Lima, Gustavo Neves
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Dissertação de Mestrado
Publicado em //2011 ENG
Relevância na Pesquisa
27.06%
Tourism services are the fastest growing industry worldwide and a key sector for some destinations, especially for remote areas where they play a central role given the lack of economic alternatives. Tourism seasonality is a complex phenomenon and it´s one of the biggest challenges faced by this industry. It is, as well, a recognized problem for most family businesses that are especially dominant in peripheral regions. The aim of this dissertation is to investigate the seasonality of tourism in family businesses, fundamentally in a supply-side perspective. Their impacts and mitigation responses are of great importance for the survival and growth of businesses, families and destination in general. To carry out this study, firstly tourism seasonality in Terceira Island in Azores was measured and characterized, and then nine semi-structured interviews were prepared and applied to nine managers of family businesses in some sub-sectors of tourism and hospitality. Other data sources were used to triangulate the research. This multiple cross-case-study had a qualitative data analysis and was interpreted by a critical realism perspective. This study serves to support and extend the conceptual framework of tourism seasonality mitigation strategies in family businesses...

Phenological synchrony and seasonality of understory Rubiaceae in the Atlantic Forest, Bahia, Brazil

Liuth,Heitor Scarpati; Talora,Daniela Custódio; Amorim,André Márcio
Fonte: Sociedade Botânica do Brasil Publicador: Sociedade Botânica do Brasil
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2013 EN
Relevância na Pesquisa
27.15%
In tropical forests with low seasonality, climatic variables generally exert a weak influence on the phenology of species. The seasonality of phenophases in closely related taxa can be controlled by phylogenetic constraints in such environments. In this study, our aim was to describe the phenology of Rubiaceae in the understory of the Atlantic Forest in the southern part of Bahia, Brazil, as well as to evaluate the seasonality and phenological synchrony of this family. For two years, we observed 90 individuals belonging to 13 species, in an area of 0.2 ha. Leaf flushing and leaf fall did not demonstrate any seasonality, were continuous for most species and correlated with few of the climatic variables. Flowering was seasonal and correlated positively with all climatic variables. Species exhibited seasonality for this phenophase with high flowering overlap among species of Psychotria, indicating an aggregated pattern for this genus. Fruiting was also seasonal and correlated with all the climatic variables, unripe fruit development peaking at the beginning of the season during which humidity is highest and fruit ripening peaking in the season during which humidity is slightly lower. The vegetative and flowering patterns observed in the study area are commonly seen in other tropical forests. The reproductive seasonality of this family can facilitate the attraction of biotic agents...

Correlation between schizophrenia and seasonality of birth in a tropical region

Mendonça,Fernanda A. S.; Machado,Diogo R.; Lima,Juliane A. F. de; Bortollotti,Gislaine M. F.; Grilo,Roseana C.; Santos,Gláucia M. T. dos
Fonte: Associação Brasileira de Saúde Coletiva Publicador: Associação Brasileira de Saúde Coletiva
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
36.76%
OBJECTIVE: To investigate the statistical relationship between season of birth and schizophrenia in 461 patients hospitalized in three psychiatric facilities in the towns of Araras, Itapira, and Espírito Santo do Pinhal, interior of São Paulo State, southeastern Brazil. METHODS: Date and place of birth of the patients were collected and used to determine the season of birth. Results were analyzed by the chi-square test. Data regarding temperature and rainfall between 1952 and 1986, corresponding to the years of birth of the patients studied, were also obtained. RESULTS: The results showed a higher prevalence of births in the winter months (p = 0.0044), a period characterized in this region by a decline in temperature and rainfall. CONCLUSION: These findings indicate a possible influence of seasonality on the pathogenesis of schizophrenia and suggest that the winter in this region, together with other factors, may contribute to the late development of the disease.

Prey foraging behavior, seasonality and time-budgets in black lion tamarins, Leontopithecus chrysopygus (Mikan 1823) (Mammalia, Callitrichidae)

KEUROGHLIAN,A.; PASSOS,F. C.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2001 EN
Relevância na Pesquisa
36.76%
Foraging behavior, seasonality and time-budgets in the Black Lion Tamarin (L. chrysopygus) was observed in the Caetetus Ecological Station, South-eastern Brazil, during 83 days between November 1988 to October 1990. For the full dry season we found that animal prey represented 11.2% of the black lion tamarin diet, while during the wet season they represented 1.9%. Foraging behavior made up 19.8% of their total activity in the dry season and only 12.8% in the wet season. These results point out that animal prey are relatively more important during the dry season, due to reduced availability of other resources, e.g. fruits, and that a greater foraging effort is required when a larger proportion of the diet is animal prey.

Impact of Birth Seasonality on Dynamics of Acute Immunizing Infections in Sub-Saharan Africa

Dorélien, Audrey M.; Ballesteros, Sebastien; Grenfell, Bryan T.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 18/10/2013 EN
Relevância na Pesquisa
27.06%
We analyze the impact of birth seasonality (seasonal oscillations in the birth rate) on the dynamics of acute, immunizing childhood infectious diseases. Previous research has explored the effect of human birth seasonality on infectious disease dynamics using parameters appropriate for the developed world. We build on this work by including in our analysis an extended range of baseline birth rates and amplitudes, which correspond to developing world settings. Additionally, our analysis accounts for seasonal forcing both in births and contact rates. We focus in particular on the dynamics of measles. In the absence of seasonal transmission rates or stochastic forcing, for typical measles epidemiological parameters, birth seasonality induces either annual or biennial epidemics. Changes in the magnitude of the birth fluctuations (birth amplitude) can induce significant changes in the size of the epidemic peaks, but have little impact on timing of disease epidemics within the year. In contrast, changes to the birth seasonality phase (location of the peak in birth amplitude within the year) significantly influence the timing of the epidemics. In the presence of seasonality in contact rates, at relatively low birth rates (20 per 1000), birth amplitude has little impact on the dynamics but does have an impact on the magnitude and timing of the epidemics. However...

Human birth seasonality: latitudinal gradient and interplay with childhood disease dynamics

Martinez-Bakker, Micaela; Bakker, Kevin M.; King, Aaron A.; Rohani, Pejman
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 22/05/2014 EN
Relevância na Pesquisa
27.06%
More than a century of ecological studies have demonstrated the importance of demography in shaping spatial and temporal variation in population dynamics. Surprisingly, the impact of seasonal recruitment on infectious disease systems has received much less attention. Here, we present data encompassing 78 years of monthly natality in the USA, and reveal pronounced seasonality in birth rates, with geographical and temporal variation in both the peak birth timing and amplitude. The timing of annual birth pulses followed a latitudinal gradient, with northern states exhibiting spring/summer peaks and southern states exhibiting autumn peaks, a pattern we also observed throughout the Northern Hemisphere. Additionally, the amplitude of United States birth seasonality was more than twofold greater in southern states versus those in the north. Next, we examined the dynamical impact of birth seasonality on childhood disease incidence, using a mechanistic model of measles. Birth seasonality was found to have the potential to alter the magnitude and periodicity of epidemics, with the effect dependent on both birth peak timing and amplitude. In a simulation study, we fitted an susceptible-exposed-infected-recovered model to simulated data, and demonstrated that ignoring birth seasonality can bias the estimation of critical epidemiological parameters. Finally...

Does seasonality drive spatial patterns in demography? Variation in survival in African reed warblers Acrocephalus baeticatus across southern Africa does not reflect global patterns

Jansen, Dorine YM; Abadi, Fitsum; Harebottle, Doug; Altwegg, Res
Fonte: John Wiley & Sons Ltd. Publicador: John Wiley & Sons Ltd.
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.06%
Among birds, northern temperate species generally have larger clutches, shorter development periods and lower adult survival than similarly-sized southern and tropical species. Even though this global pattern is well accepted, the driving mechanism is still not fully understood. The main theories are founded on the differing environmental seasonality of these zones (higher seasonality in the North). These patterns arise in cross-species comparisons, but we hypothesized that the same patterns should arise among populations within a species if different types of seasonality select for different life histories. Few studies have examined this. We estimated survival of an azonal habitat specialist, the African reed warbler, across the environmentally diverse African subcontinent, and related survival to latitude and to the seasonality of the different environments of their breeding habitats. Data (1998–2010) collected through a public ringing scheme were analyzed with hierarchical capture-mark-recapture models to determine resident adult survival and its spatial variance across sixteen vegetation units spread across four biomes. The models were defined as state-space multi-state models to account for transience and implemented in a Bayesian framework. We did not find a latitudinal trend in survival or a clear link between seasonality and survival. Spatial variation in survival was substantial across the sixteen sites (spatial standard deviation of the logit mean survival: 0.70...

On the Final Size of Epidemics with Seasonality

Bacäer, N.; Gomes, M.G.M.
Fonte: Fundação Calouste Gulbenkian Publicador: Fundação Calouste Gulbenkian
Tipo: Artigo de Revista Científica
Publicado em //2009 ENG
Relevância na Pesquisa
36.76%
We first study an SIR system of differential equations with periodic coefficients describing an epidemic in a seasonal environment. Unlike in a constant environment, the final epidemic size may not be an increasing function of the basic reproduction number ℛ0 or of the initial fraction of infected people. Moreover, large epidemics can happen even if ℛ0<1. But like in a constant environment, the final epidemic size tends to 0 when ℛ0<1 and the initial fraction of infected people tends to 0. When ℛ0>1, the final epidemic size is bigger than the fraction 1−1/ℛ0 of the initially nonimmune population. In summary, the basic reproduction number ℛ0 keeps its classical threshold property but many other properties are no longer true in a seasonal environment. These theoretical results should be kept in mind when analyzing data for emerging vector-borne diseases (West-Nile, dengue, chikungunya) or air-borne diseases (SARS, pandemic influenza); all these diseases being influenced by seasonality.

Prenatal Seasonality, Child Growth, and Schooling Investments : Evidence from Rural Indonesia

Yamauchi, Futoshi
Fonte: Taylor and Francis Publicador: Taylor and Francis
Tipo: Journal Article; Publications & Research :: Journal Article; Publications & Research
EN_US
Relevância na Pesquisa
36.76%
This article examines the impacts of prenatal conditions on child growth using recent data from Indonesia. There is seasonality in birthweight: this measure is significantly higher immediately after the main rice harvest in the country. The empirical results show that an increase in birthweight improves child growth outcomes as measured by the height and weight z-scores, as well as schooling performance as measured by age at start of schooling and number of grades repeated. The interactions of ecological variations affect early childhood human capital formation and can have long-term impacts on children's outcomes.

What drives the seasonality of photosynthesis across the Amazon basin? A cross-site analysis of eddy flux tower measurements from the Brasil flux network

Restrepo-Coupe, Natalia; Rocha, Humberto Ribeiro da; Hutyra, Lucy R.; Araujo, Alessandro C. da; Borma, Laura de Simone; Christoffersen, Bradley; Cardoso, Fernando L.; Costa, Antonio C. Lola da; Fitzjarrald, David R.; Goulden, Michael L.; Kruijt, Bart; Mai
Fonte: Amsterdam Publicador: Amsterdam
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.76%
We investigated the seasonal patterns of Amazonian forest photosynthetic activity, and the effects thereon of variations in climate and land-use, by integrating data from a network of ground-based eddy flux towers in Brazil established as part of the ‘Large-Scale Biosphere Atmosphere Experiment in Amazonia’ project. We found that degree of water limitation, as indicated by the seasonality of the ratio of sensible to latent heat flux (Bowen ratio) predicts seasonal patterns of photosynthesis. In equatorial Amazonian forests (5◦ N–5◦ S), water limitation is absent, and photosynthetic fluxes (or gross ecosystem productivity, GEP) exhibit high or increasing levels of photosynthetic activity as the dry season progresses, likely a consequence of allocation to growth of new leaves. In contrast, forests along the southern flank of the Amazon, pastures converted from forest, and mixed forest-grass savanna, exhibit dry-season declines in GEP, consistent with increasing degrees of water limitation. Although previous work showed tropical ecosystem evapotranspiration (ET) is driven by incoming radiation, GEP observations reported here surprisingly show no or negative relationships with photosynthetically active radiation (PAR). Instead...

Estacionalidad en las aves del Chaco Paraguayo central; Avian seasonality at a locality in the Central Paraguayan Chaco

Brooks, Daniel M.
Fonte: Aves Argentinas / Asociación Ornitológica del Plata Publicador: Aves Argentinas / Asociación Ornitológica del Plata
Tipo: info:eu-repo/semantics/article; artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em /11/1997 ENG
Relevância na Pesquisa
36.76%
Registré la abundancia de especies de aves en el Chaco Paraguayo central, Agosto de 1989 hasta Agosto de 1990, para investigar la variación estacional al nivel de grupo funcional o gremio (guild). Las características usadas para definir grupos funcionales fueron la dependicia del agua o la dieta primaria. El numero de especies (abundancia: raro) por grupo funcional son: insectívoras (21 :35), granívoras and folívoras (20:6), faunívoras (14:13), especies asociadas al agua (4:28), detritívoras (3: 1), nectarívoras (1: 1), y frugívoras (0:5). El grupo con la variación estacional mayor fue las insectívoras (SD = 1.63), siguiéndoles las especies asociado al agua, (SD = 1.43), las nectarívoras (SD = 1.41), faunívoras (SD = 1.33), granívoras and folívoras (SD = 1.20), y detritívoras (SD = 0.50). Pruebas de chi cuadrado indican que la diferencia entre especies abundantes y raras son muy significativas para las insectívoras (P < 0.01), granívoras (P < 0.005), y especies asociadas al agua (p < 0.005). Los resultados se interpretan en términos de procesos, de ecología y evolución.; Abundances of different species of birds were recorded in the central Paraguayan Chaco from August 1989 to August 1990 to investigate seasonal variation at the guild level. Species were grouped into guilds based upon primary diet or water dependence. The number of species (abundant : rare) in each guild is as follows: insectivores (21 :35)...

Estacionalidad en las aves del Chaco Paraguayo central; Avian seasonality at a locality in the Central Paraguayan Chaco

Brooks, Daniel M.
Fonte: Revista de Ornitología Neotropical; Aves Argentinas; Aves Argentinas / Asociación Ornitológica del Plata Publicador: Revista de Ornitología Neotropical; Aves Argentinas; Aves Argentinas / Asociación Ornitológica del Plata
Tipo: info:eu-repo/semantics/article; artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em /11/1997 ENG
Relevância na Pesquisa
36.76%
Registré la abundancia de especies de aves en el Chaco Paraguayo central, Agosto de 1989 hasta Agosto de 1990, para investigar la variación estacional al nivel de grupo funcional o gremio (guild). Las características usadas para definir grupos funcionales fueron la dependicia del agua o la dieta primaria. El numero de especies (abundancia: raro) por grupo funcional son: insectívoras (21 :35), granívoras and folívoras (20:6), faunívoras (14:13), especies asociadas al agua (4:28), detritívoras (3: 1), nectarívoras (1: 1), y frugívoras (0:5). El grupo con la variación estacional mayor fue las insectívoras (SD = 1.63), siguiéndoles las especies asociado al agua, (SD = 1.43), las nectarívoras (SD = 1.41), faunívoras (SD = 1.33), granívoras and folívoras (SD = 1.20), y detritívoras (SD = 0.50). Pruebas de chi cuadrado indican que la diferencia entre especies abundantes y raras son muy significativas para las insectívoras (P < 0.01), granívoras (P < 0.005), y especies asociadas al agua (p < 0.005). Los resultados se interpretan en términos de procesos, de ecología y evolución.; Abundances of different species of birds were recorded in the central Paraguayan Chaco from August 1989 to August 1990 to investigate seasonal variation at the guild level. Species were grouped into guilds based upon primary diet or water dependence. The number of species (abundant : rare) in each guild is as follows: insectivores (21 :35)...

Analysis of rainfall seasonality from observations and climate models

Pascale, Salvatore; Lucarini, Valerio; Feng, Xue; Porporato, Amilcare; Hasson, Shabeh ul
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
27.06%
Two new indicators of rainfall seasonality based on information entropy, the relative entropy (RE) and the dimensionless seasonality index (DSI), together with the mean annual rainfall, are evaluated on a global scale for recently updated precipitation gridded datasets and for historical simulations from coupled atmosphere-ocean general circulation models. The RE provides a measure of the number of wet months and, for precipitation regimes featuring one maximum in the monthly rain distribution, it is related to the duration of the wet season. The DSI combines the rainfall intensity with its degree of seasonality and it is an indicator of the extent of the global monsoon region. We show that the RE and the DSI are fairly independent of the time resolution of the precipitation data, thereby allowing objective metrics for model intercomparison and ranking. Regions with different precipitation regimes are classified and characterized in terms of RE and DSI. Comparison of different land observational datasets reveals substantial difference in their local representation of seasonality. It is shown that two-dimensional maps of RE provide an easy way to compare rainfall seasonality from various datasets and to determine areas of interest. CMIP5 models consistently overestimate the RE over tropical Latin America and underestimate it in Western Africa and East Asia. It is demonstrated that positive RE biases in a GCM are associated with simulated monthly precipitation fractions which are too large during the wet months and too small in the months preceding the wet season; negative biases are instead due to an excess of rainfall during the dry months.; Comment: 35 pages...

Nonparametric and adaptive modeling of dynamic seasonality and trend with heteroscedastic and dependent errors

Chen, Yu-Chun; Cheng, Ming-Yen; Wu, Hau-tieng
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
27.06%
Seasonality (or periodicity) and trend are features describing an observed sequence, and extracting these features is an important issue in many scientific fields. However, it is not an easy task for existing methods to analyze simultaneously the trend and {\it dynamics} of the seasonality such as time-varying frequency and amplitude, and the {\it adaptivity} of the analysis to such dynamics and robustness to heteroscedastic, dependent errors is not guaranteed. These tasks become even more challenging when there exist multiple seasonal components. We propose a nonparametric model to describe the dynamics of multi-component seasonality, and investigate the recently developed Synchrosqueezing transform (SST) in extracting these features in the presence of a trend and heteroscedastic, dependent errors. The identifiability problem of the nonparametric seasonality model is studied, and the adaptivity and robustness properties of the SST are theoretically justified in both discrete- and continuous-time settings. Consequently we have a new technique for de-coupling the trend, seasonality and heteroscedastic, dependent error process in a general nonparametric setup. Results of a series of simulations are provided, and the incidence time series of varicella and herpes zoster in Taiwan and respiratory signals observed from a sleep study are analyzed.

Climatic seasonality may affect ecological network structure: Food webs and mutualistic networks

Takemoto, Kazuhiro; Kanamaru, Saori; Feng, Wenfeng
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/06/2014
Relevância na Pesquisa
27.15%
Ecological networks exhibit non-random structural patterns, such as modularity and nestedness, which indicate ecosystem stability, species diversity, and connectance. Such structure-stability relationships are well known. However, another important perspective is less well understood: the relationship between the environment and structure. Inspired by theoretical studies that suggest that network structure can change due to environmental variability, we collected data on a number of empirical food webs and mutualistic networks and evaluated the effect of climatic seasonality on ecological network structure. As expected, we found that climatic seasonality affects ecological network structure. In particular, an increase in modularity due to climatic seasonality was observed in food webs; however, it is debatable whether this occurs in mutualistic networks. Interestingly, the type of climatic seasonality that affects network structure differs with ecosystem type. Rainfall and temperature seasonality influence freshwater food webs and mutualistic networks, respectively; food webs are smaller, and more modular, with increasing rainfall seasonality. Mutualistic networks exhibit a higher diversity (particularly of animals) with increasing temperature seasonality. These results confirm the theoretical prediction that stability increases with greater perturbation. Although these results are still debatable because of several limitations in the data analysis...

Seasonality of monoterpene emission potentials in Quercus ilex and Pinus pinea : implications for regional VOC emissions modeling

Keenan, Trevor; Niinemets, Ülo; Sabaté i Jorba, Santi; Gracia, Carles; Peñuelas, Josep
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2009 ENG
Relevância na Pesquisa
27.15%
VOC emissions from terrestrial ecosystems provide one of the principal controls over oxidative photochemistry in the lower atmosphere and the resulting air pollution. Such atmospheric processes have strong seasonal cycles. Although similar seasonal cycles in VOC emissions from terrestrial ecosystems have been reported, regional emissions inventories generally omit the effect of seasonality on emissions. We compiled measurement data on seasonal variations in monoterpene emissions potentials for two evergreen species (Quercus ilex and Pinus pinea) and used these data to construct two contrasting seasonal response functions for the inclusion in monoterpene emission models. We included these responses in the Niinemets et al. model and compared simulation results to those of the MEGAN model, both with and without its predicted seasonality. The effect of seasonality on regional monoterpene emissions inventories for European Mediterranean forests dominated by these species was tested for both models, using the GOTILWA+ biosphere model platform. The consideration of seasonality in the Niinemets et al. model reduced total estimated annual monoterpene emissions by up to 65% in some regions, with largest reductions at lower latitudes. The MEGAN model demonstrated a much weaker seasonal response than that in the Niinemets et al. model...

An examination of seasonality experienced by Australians living in a continental temperate climate zone

Parslow, Ruth; Jorm, Anthony F; Butterworth, Peter; Jacomb, Trish; Rodgers, Bryan
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
27.06%
Background: To date, there has been only limited information on factors associated with seasonal changes in mood and behaviour experienced by a random sample of Australians living in a continental temperate climate region. This paper identifies socio-demographic, psychological and personality factors associated with reporting higher levels of seasonality. Method: Information on seasonal change using the Seasonal Pattern Assessment Questionnaire (SPAQ) was obtained from 7485 persons in three age groups. Age and sex differences in seasonality scores were examined. Those meeting probable caseness for seasonal affective disorder were identified and compared with less-seasonal participants on a range of state and trait measures. Results: Levels of seasonality reported by survey participants were comparable to those reported in northern hemisphere studies of randomly selected community samples. However, these levels were significantly lower than other key studies outside Australia and previous Australian findings. Compared with less-seasonal participants, those reporting seasonal change had more current depressive and anxiety symptoms and higher levels of negative affect, regardless of season of interview. Limitations: This study is likely to over-estimate the number of participants who meet requirements for caseness for seasonal affective disorder. Conclusion: Levels of seasonality experienced by a random sample of Australians living in a temperate climate are comparable to those reported by similar groups in the northern hemisphere. Importantly...

A cross-sectional study of factors affecting seasonality in bipolar disorder

Mittal,P K; Mehta,S; Solanki,R K; Swami,M K; Meena,P S
Fonte: South African Journal of Psychiatry Publicador: South African Journal of Psychiatry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
27.06%
BACKGROUND: Researchers have evinced interest in the effect of seasonal variations on mood and behavioural patterns in affective disorders. OBJECTIVE: To study seasonality in bipolar disorder (BD) patients and also the factors affecting this seasonality. METHOD: Forty-nine patients with BD in euthymic phase were recruited and analysed using the Seasonal Pattern Assessment Questionnaire and Morningness-Eveningness Questionnaire. RESULTS: Most of the patients were morning types but chronotype had no influence on seasonality. Age of patient and number of episodes were the most important factors affecting seasonality in BD. CONCLUSION: Seasonality and its influencing factors must be considered while managing bipolar disorder.

Correlation between schizophrenia and seasonality of birth in a tropical region

Mendonça,Fernanda A. S.; Machado,Diogo R.; Lima,Juliane A. F. de; Bortollotti,Gislaine M. F.; Grilo,Roseana C.; Santos,Gláucia M. T. dos
Fonte: Associação Brasileira de Pós -Graduação em Saúde Coletiva Publicador: Associação Brasileira de Pós -Graduação em Saúde Coletiva
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
36.76%
OBJECTIVE: To investigate the statistical relationship between season of birth and schizophrenia in 461 patients hospitalized in three psychiatric facilities in the towns of Araras, Itapira, and Espírito Santo do Pinhal, interior of São Paulo State, southeastern Brazil. METHODS: Date and place of birth of the patients were collected and used to determine the season of birth. Results were analyzed by the chi-square test. Data regarding temperature and rainfall between 1952 and 1986, corresponding to the years of birth of the patients studied, were also obtained. RESULTS: The results showed a higher prevalence of births in the winter months (p = 0.0044), a period characterized in this region by a decline in temperature and rainfall. CONCLUSION: These findings indicate a possible influence of seasonality on the pathogenesis of schizophrenia and suggest that the winter in this region, together with other factors, may contribute to the late development of the disease.