Cyanobacterial blooms in stratified and destratified eutrophic reservoirs in semi-arid region of Brazil

This study investigated the dynamics of cyanobacteria in two deep, eutrophic reservoirs in a semi-arid region of Brazil during periods of stratification and destratification. Four collections were carried out at each reservoir at two depths at three-month intervals. The following abiotic variables were analyzed: water temperature, dissolved oxygen, pH, turbidity, water transparency, total phosphorus, total dissolved phosphorus, orthophosphate and total nitrogen. Phytoplankton density was quantified for the determination of the biomass of cyanobacteria. The data were analyzed using CCA. Higher mean phytoplankton biomass values (29.8 mm(3).L(-1)) occurred in the period of thermal stratification. A greater similarity in the phytoplankton communities also occurred in this period and was related to the development of cyanobacteria, mainly Cylindrospermopsis raciborskii (>3.9 mm(3).L(-1)). During the period of thermal destratification, this species co-dominated the environment with Planktothrix agardhii, Geitlerinema amphibium, Microcystis aeruginosa and Merismopedia tenuissima, as well as with diatoms and phytoflagellates. Environmental instability and competition among algae hindered the establishment of blooms more during the mixture period than during the stratification period. Thermal changes in the water column caused by climatologic events altered other physiochemical conditions of the water, leading to changes in the composition and biomass of the cyanobacterial community in tropical reservoirs.     

The Effect of Body Condition on Ovarian Activity of Free Ranging Tropical Jennies (Equus asinus)

Serial ultrasonography was performed on seven jennies to study the effect of seasonally fluctuating body condition on ovarian activity during the dry, short rainy and long rainy seasons. Kendall Tau correlations and differences of least square mean values were compared. A distinct seasonal pattern was observed both in body condition and ovarian activity. The mean (±SD) Body Condition Score (BCS) was lowest during the dry season 2.6 ± 0.45 when compared with 3.5 ± 0.52 and 3.9 ± 0.58 during the short and long rainy seasons, respectively. The mean (±SD) number of total follicles was also proportionally low 7.3 ± 1.6 during the dry season compared with 9.6 ± 2.4 and 11.3 ± 3.3 found during the short and the long rainy seasons, respectively. The BCS was positively correlated to the total number of follicles and the diameter of the largest follicle during all seasons. Periods of increasing BCS and transition between seasons with both increasing and decreasing body conditions were strongly correlated to the number and size of ovarian follicles. Seasonal fluctuation in the body condition was found to be the result of variation in feed resource and ovarian activity was also closely following this seasonal pattern. The improvement in body condition has generally, a positive impact on emergence of small growing follicles there by having influence on the total count of ovarian follicles.     

Plankton diversity and limnological characterization in two shallow tropical urban reservoirs of Pernambuco State, Brazil

Plankton diversity, physical and chemical variables and chlorophyll a were analyzed in two shallow urban reservoirs with different trophic degrees on Pernambuco State, northeastern Brazil. High eutrophication levels were observed in Apipucos reservoir, while Prata reservoir was considered oligotrophic. Values reported for physical and chemical variables and chlorophyll a differed among the studied ecosystems. Richness and plankton diversity were higher in Apipucos reservoir especially for phytoplankton. The presence of potential toxic Cyanophyceae in both reservoirs reflects a problem mainly to Prata reservoir, which is used for public water supply. Differences were observed for some variables among sites of study in Apipucos reservoir, while the differences among strata were negligible in both reservoirs, reflecting the water column mixing by wind action. Rainfall regulated the temporal dynamics for the analyzed variables, with significant seasonal differences, mainly for the major of limnological variables in Apipucos reservoir. Plankton diversity was higher in Apipucos reservoir, especially to phytoplankton, showing that eutrophication and pollution can favor plankton diversity in tropical urban shallow reservoirs.     

Relationships between Biochemical Bone Turnover Markers, Season, and Inflammatory Status Indices in Prepubertal Gambian Boys

Seasonal and interindividual differences in food availability and illnesses cause variations in growth, including bone growth, in children in developing countries. We investigated seasonal differences in biochemical (serum) markers of bone metabolism and relationships between these markers (procollagen type I N propeptide [P1NP], serum C-terminal telopeptide of type 1 collagen [S-CTX]) and serum markers of inflammation (α₁- antichymotrypsin [ACT], C-reactive protein [CRP], sialic acid) in prepubertal Gambian boys. Three seasonal time points were chosen: August, mid-rainy season; October, late rainy season (both are associated with decreased food supply, increased prevalence of infection, reduced weight gain, and stunting); and April, late dry season, when environmental conditions are better and rates of weight gain are higher. The prevalence of raised inflammatory markers was high: 29% of ACT values >0.40 g/L in August, 42% >0.40 g/L in October, and 18% >0.40 g/L in April. Of CRP values, 92–96% were >0.47 mg/L and 30%, 46%, and 18% were >3.95 mg/L in August, October, and April, respectively. Also, 42–52% of sialic acid values were >648 mg/L. Of the bone markers, S-CTX exhibited the highest values in August; P1NP did not vary with season. Inverse relationships between each bone marker and the acute phase markers occurred, with the strongest relationships between P1NP and ACT or sialic acid. We conclude that bone collagen synthesis and turnover are reduced during inflammation in rural Gambian boys. Biochemical indices can provide powerful, single-time point evidence of infection and growth-faltering episodes.     

Flowering phenology and pollination of ornithophilous species in two habitats of Serra da Bodoquena, Mato Grosso do Sul, Brazil

The aim of this study is to describe interactions between hummingbirds and ornithophilous species at Serra da Bodoquena in midwest Brazil, with focus on flowering phenology and pollination of these plant species. In two habitats, gallery forest and semi-deciduous forest, data on flowering phenology of ornithophilous species were collected monthly over 14 months. In addition, data on morphology and floral biology, as well as visitor frequency and hummingbird behavior, were recorded. The studied community contained eight ornithophilous plant species and six hummingbird species. The ornithophilous species flowered throughout the year, and the greatest abundance of flowers was at the end of the rainy season and the beginning of the dry one. The herit huingbird Phaethornis pretrei and feales of Thalurania furcata, were the most similar in floral resource use. Acanthaceae is the most representative family of ornithophilous plant species in Serra da Bodoquena and, thus, represents the main food source for hummingbirds. Ruellia angustiflora is especially important because it flowers continuously throughout the year and is a significant food resource for P. pretrei, which is the main visitor for this plant guild.     

Effects of Seasonal and Physiological Variations on the Serum Chemistry,Vitamins and Thyroid Hormone Concentrations in Sheep

The aim of this study was to investigate the possible effects of the reproductive status and seasonal variations on the serum chemistry and vitamin status and their relationships with the thyroid hormones in Sakiz‐Awassi crossbreed sheep. The sheep (n = 34) were divided into two groups. The first group (n = 22) was mated; the second group (n = 12) was not mated. Their serum samples were collected four times a year at the each season and under reproductive status. The periods are 1, early pregnancy (October); 2, late pregnancy (January); 3, lactation (April); and 4, dry season (July). The results of this study indicated that (1) total protein (TP), globulin, cholesterol, creatinine, uric acid and T4/T3 vary with reproductive status but not seasonal variations; (2) alanine aminotransferase, T4, fT4 concentrations in serum vary only with reproductive status; (3) the urea, creatine kinase, lactate dehydrogenase, alkaline phosphatase, aspartate aminotransferase, amylase, albumin, triglyceride, VLDL, Vit A–E, T3 and fT3 concentration could vary with both reproductive status and seasonal variations; (4) the glucose, γ‐glutamyl transpeptidase, folate concentrations were altered neither season of the year nor the reproductive status; (5) a single reference interval for folate, γ‐glutamyl transpeptidase (GGT), glucose, TP, globulin, cholesterol, creatinine, uric acid and T4/T3 can be used for both mated and non‐mated sheep because of no differences were found due to the reproductive status. Taking the results together suggests that reproductive status and seasonal variations have to be taken into consideration for a correct interpretation of the serum chemistry values of sheep. Nutritional supplements are required for sheep during certain periods to avoid a decline of their performance, which would then represent consequent economic, loses.     

Seasonal variation of Buerger's disease in Northern part of Thailand.

OBJECTIVES: Buerger's disease is a common peripheral arterial occlusive disease in Asia, Middle East, and eastern European countries. This study was undertaken to investigate the seasonal variation in admission pattern of with patients Buerger's disease at our institution which is a referral hospital in the Northern Thailand. MATERIAL AND METHODS: Patients with Buerger's disease admitted to Chiang Mai University Hospital between January 1987 and December 2002 were studied retrospectively. Data are reported as mean+/-SD. Statistical significance was analyzed by Chi-square test. RESULTS: Eighty-four patients (82 men and two women) with Buerger's disease were evaluated on 121 admissions. Forty-five were newly diagnosed cases, who were admitted for initial treatment, and 39 were known cases who experienced worsening of the disease. Sixty-three admissions (52%) took place during winter (November to February), 44 admissions (34.6%) during the rainy season (June-October) and only 14 admissions (11.6%) occurred during the summer (March-May). There was a significant difference in the monthly admission rates during the three seasons (p<0.05). CONCLUSION: Admission for Buerger's disease showed a significant seasonal variation, with a peak in the winter followed by the rainy and summer season, respectively. Further research is needed to confirm our findings and evaluate the underlying mechanisms.     

Reproduction and structure of the population of the Chaetognath Parasagitta friderici in Guanabara Bay (Brazil) based on short term sampling

The aim of this study was to describe the total density, densities of developmental stages and the reproduction period of Parasagitta friderici. Weekly samples were collected at one station in the channel of Guanabara Bay, Rio de Janeiro, during one year. Three vertical hauls were made for each sample, and P. friderici was separated, the developmental stages were identified, and body length (BL), ovary length (OL) and seminal vesicle width (SVW) were measured. Throughout the year P. friderici was the most abundant chaetognath species occurring in all four developmental stages, the densities of which varied from week to week. Higher densities of adults occurred in the spring, followed by peaks of juveniles in the summer. Although P. friderici seems to reproduce continuously in Guanabara Bay, a reproductive peak was apparent during the spring. The intensification of reproduction during the spring, with juveniles occurring in the summer, seems to be related to the period of higher food supply during the rainy season and intrusions of the South Atlantic Central Water.     

Nutrient budgets (C, N and P) and trophic dynamics of a Brazilian tropical estuary: Barra das Jangadas

This paper focuses on the nutrient dynamics of a tropical estuary on the northeastern Brazilian coast, studied using the LOICZ biogeochemical budgeting protocol. We describe the methodology and assumptions underlying this model. Input data (monthly for rainfall, evaporation, river discharge, and concentrations of salt, phosphorus and nitrogen) were obtained during field campaigns in the Barra das Jangadas Estuary (BJE) over a 5 years period (1999 to 2003). Mass balance results indicate large inputs of nutrients to the system. The model shows that the seasonal variation of the Net Ecosystem Metabolism (NEM) indicates that the system passes from a stage of organic matter liquid production and mineralization during the dry season (-0.5 mmoles C m(-2) d(-1)) to liquid mineralization during the rainy season (-19 mmoles C m(-2) d(-1)). We suggest that the system varies slightly between autotrophy and heterotrophy during the year due to the rainfall regime, human activities in the basin (density population and sugarcane plantations), and associated DIP riverine loads. High per capita loads of N and P indicate a high population density and high runoff. The application of flux balance modeling was useful to understand the nutrient dynamics of this typical small tropical estuary.     

Seasonal variation in the essential oil of Pilocarpus microphyllus Stapf

The essential oils of the leaves and fine stems of Pilocarpus microphyllus, collected on iron mineralized soil of the Serra de Caraj s, Southeast of Par State, Brazil, during the rainy and dry seasons, were obtained by hydrodistillation and analyzed by GC-MS. The main identified compounds were 2-tridecanone, beta-caryophyllene, 2-pentadecanone, caryophyllene oxide and germacrene D. Their percentage contents varied with the season, the greater values having been detected mainly in the rainy season. For 2-tridecanone and beta-caryophyllene the higher values were observed in the fine stem oils for the former, and in the leaf oils for the latter. For 2-pentadecanone, caryophyllene oxide and germacrene D they were also in the leaf oils. In general, the leaf oils were very distinguishable from those of fine stem oils, even in the same specimen.     

Scenario of hand fractures in a tertiary hospital: a prospective study

Hand injuries contribute a considerable workload for any individual accident and emergency department. Not many studies are found in the Indian literature as far as the epidemiology of hand fractures is concerned. A prospective survey of the medical charts of all 10,977 patients attending the accident and emergency department of the Kasturba Medical College, Manipal, from August 1, 2004, to July 31, 2006 was performed. Of these, 2,836 sustained one or more fractures, and hand fractures accounted for 5.4 % of all fractures. This study compared the prevalence of hand fractures with that of all fractures and investigated whether there was a seasonal variation in their prevalence. The incidence of all the fractures (of upper and lower limbs) increased during the rainy season (from May to August), but the distribution of hand fractures remained relatively constant throughout the year. Among carpal bones, scaphoid was the most common injured carpal bone. Only 6 % of patients with hand fractures required admission. Hand fractures are common and have a substantial impact on national health care, and it is essential to estimate the frequency and describe the demographics of patients with this condition.     

Efficiency of playback for assessing the occurrence of five bird species in Brazilian Atlantic Forest fragments

Playback of bird songs is a useful technique for species detection; however, this method is usually not standardized. We tested playback efficiency for five Atlantic Forest birds (White-browed Warbler Basileuterus leucoblepharus, Giant Antshrike Batara cinerea, Swallow-tailed Manakin Chiroxiphia caudata, Whiteshouldered Fire-eye Pyriglena leucoptera and Surucua Trogon Trogon surrucura) for different time of the day, season of the year and species abundance at the Morro Grande Forest Reserve (South-eastern Brazil) and at thirteen forest fragments in a nearby landscape. Vocalizations were broadcasted monthly at sunrise, noon and sunset, during one year. For B. leucoblepharus, C. caudata and T. surrucura, sunrise and noon were more efficient than sunset. Batara cinerea presented higher efficiency from July to October. Playback expanded the favourable period for avifaunal surveys in tropical forest, usually restricted to early morning in the breeding season. The playback was efficient in detecting the presence of all species when the abundance was not too low. But only B. leucoblepharus and T. surrucura showed abundance values significantly related to this efficiency. The present study provided a precise indication of the best daily and seasonal periods and a confidence interval to maximize the efficiency of playback to detect the occurrence of these forest species.     

The Effect of Latitude on the Risk and Seasonal Variation in Hip Fracture in Sweden

Although the optimal requirement of vitamin D for skeletal health in the general community is controversial, vitamin D deficiency impairs bone mineralization and increases bone turnover via secondary hyperparathyroidism, thus accelerating bone loss and increasing fracture risk. Support for a role of vitamin D deficiency in the epidemiology of hip fracture is found in the seasonal variation of hip fracture incidence that is reported in several studies. If the association were causal, then the incidence and amplitude of the seasonal variation in hip fracture risk should vary by latitude. We addressed this hypothesis by examining the incidence of hip fracture in men and women aged 50 years or more from Sweden (latitudes 55 to 69°) between 1987 and 2009. In order to reduce double counting, only one fracture in a period of a year was counted per individual. Men contributed 104,888 fractures in 33,313,065 person years and women 264,362 fractures in 38,387,660 person years. The effects of season and latitude were examined by Poisson regression. As expected, hip fracture rates were higher in women than in men. After adjustment for age, season and population density, hip fracture incidence increased by 3.0% (95% CI: 2.7–3.2%) per degree increase in latitude for men and by 1.9% (95% CI: 1.8–2.1%) for women. There was a marked seasonal variation of hip fracture with the highest risk in February and lower by 37.5% in men and by 23.5% women during the summer. There were significant interactions of amplitude of the seasonal variation with latitude (p < 0.001 for both men and women), indicating that seasonal variation during the year was more pronounced in the north of Sweden than in the south. The associations found with latitude and season is consistent with a role of vitamin D in hip fracture causation. © 2014 American Society for Bone and Mineral Research.     

Relation of fractional 47Ca retention to season and rates of bone loss in healthy postmenopausal women.

Fractional whole-body retention of 47Ca (retention fraction) in 58 healthy postmenopausal women participating in a calcium supplementation trial was examined for seasonal variation and for relationships to rates of bone loss and plasma vitamin D levels. Retention fraction was measured after 18 months in the trial. Bone mineral densities of the radius, femoral neck, and lumbar spine were measured at baseline, 12 months, and 24 months in the trial, and plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] and 25-hydroxyvitamin D (25-OHD) at 12, 18, and 24 months. The adjusted retention (retention fraction adjusted for total calcium intake, smoking status, and log years since menopause) was significantly higher in women evaluated in the months of August through October (mean +/- SD, 19.8 +/- 4.1%, n = 13) than in March through May (mean +/- SD, 17.0 +/- 4.7%, n = 18, p = 0.05). Plasma 25-OHD was associated with retention fraction only in women with low calcium intakes (partial r = 0.69 controlling for total calcium intake and log body mass index, n = 14, p = 0.01). Plasma 1,25-(OH)2D was not related to retention fraction. Adjusted retention, independent of total calcium intake, log years since menopause, smoking status, and season, explained 8% of the variability in the annual change in radius density (partial r = 0.29, p less than 0.05). No significant associations were seen at the spine and femur.(ABSTRACT TRUNCATED AT 250 WORDS)     

Daily, monthly and seasonal variation in PSA levels and the association with weather parameters

PSA levels have shown daily and seasonal variation, although data are conflicting regarding the season with higher PSA levels and the clinical relevance of this. We assessed the correlation of total PSA levels with meteorological data on a daily, weekly, monthly and seasonal basis. Data from 53,224 men aged 45-74 years, with an initial PSA <10.0 ng ml(-1) were correlated with temperature (°C), duration of bright sunshine (hours) and rainfall (mm). There was seasonal variation in PSA levels, with median PSA being higher in spring compared with other seasons (1.18 vs 1.10 ng ml(-1), P = 0.004). Seasonal variation was not apparent when PSA levels were age-adjusted (P = 0.112). Total PSA was not correlated with daily, weekly or monthly hours of sunshine, rainfall or mean temperature. In contrast, age-adjusted PSA varied with weekday, with higher PSA levels on Thursday and Friday compared with other days (1.16 vs 1.10 ng ml(-1), respectively). On multivariate analysis, only age predicted for PSA levels >3.0 ng ml(-1). In conclusion, PSA levels did show seasonal variation, although there was no direct correlation between PSA and any meteorological parameter. The degree of seasonal variation is small and the decision to proceed to prostate biopsy should be independent of season or weather parameters.     

Seasonal changes in symptom score and uroflowmetry in patients with lower urinary tract symptoms

OBJECTIVE: To determine whether subjective or objective seasonal changes occur in patients with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). MATERIAL AND METHODS: A total of 31 patients with LUTS were observed for >5 years. Their International Prostate Symptom Score (IPSS), quality of life (QOL) score, maximum flow rate (Qmax), voided volume (VV) a nd post-void residual (PVR) we re measured every month. RESULTS: Total IPSS, QOL, VV or PVR did not show any seasonal changes between the three seasons: summer (hot season: June to September); winter (cold season: December to March); and spring and fall (comfortable season: April, May, October and November). Furthermore, when the IPSS was examined by dividing it into storage symptoms (frequency, urgency and nocturia) and voiding symptoms (incomplete emptying, intermittency, weak stream and straining), no significant seasonal changes were detected. Only Qmax showed a significant seasonal change, being higher in both the cold season (median 10.4 ml/s) and the comfortable season (median 10.1 ml/s) than in the hot season (median 9.4 ml/s). CONCLUSIONS: It has generally been thought that LUTS worsen in winter. Our results indicate that the IPSS and the QOL score remain nearly constant if they are determined regularly over an extended period of time. Qmax may however be influenced by seasonal changes in temperature.     

Growth ring analysis of fossil coniferous woods from early cretaceous of Araripe Basin

Growth ring analysis on silicified coniferous woods from the Miss?o Velha Formation (Araripe Basin - Brazil) has yielded important information about periodicity of wood production during the Early Cretaceous in the equatorial belt. Despite warm temperatures, dendrological data indicate that the climate was characterized by cyclical alternation of dry and rainy periods influenced by cyclical precipitations, typical of tropical wet and dry or savanna climate. The abundance of false growth rings can be attributed to both occasional droughts and arthropod damage. The present climate data agree with palaeoclimatic models that inferred summer-wet biomes for the Late Jurassic/Early Cretaceous boundary in the southern equatorial belt.     

Effect of thunderstorms and airborne grass pollen on the incidence of acute asthma in England, 1990-94

BACKGROUND: Thunderstorms and prior grass pollen counts were investigated as predictors of daily hospital admissions for asthma in England. This study was motivated by reports in the literature of spectacular asthma epidemics associated with thunderstorms, particularly in the grass pollen season. METHODS: Asthma admissions for two age groups (0-14 years and 15 and over) were measured using the Hospital Episodes System (HES) in the 14 regional health authorities (RHAs) in England. Thunderstorms were measured daily in each RHA using densities of sferics (lightning flashes). Relative asthma excesses for moderate positive and exceptionally high sferic densities, with or without previous high grass pollen counts, were measured using log linear autoregression--allowing for weekly, seasonal, and longer term background variation--and pooled over RHAs by calculating geometric means. RESULTS: Relative risks from all RHAs were pooled to form geometric means. Exceptional sferic densities were associated with a relative excess risk of around 25% in both age groups. Moderate sferic densities were associated with a smaller excess, statistically significant in the two age groups taken together. In five RHAs in which grass pollen counts were available, high pollen counts for the previous five days were associated with an amplification of the excess associated with thunderstorms. CONCLUSION: Very large sferic densities are associated with moderate rises in hospital admissions for acute asthma. However, typical thunderstorm days are not associated with spectacular asthma epidemics of the scale previously reported in the literature. Thunderstorm-associated excesses are amplified after a run of high pollen counts.


     

Seasonal variation in semen quality of swamp buffalo bulls （Bubalus bubalis） in Thailand

Aim： To test the hypothesis that season affects the semen quality of swamp buffalo （Bubalus bubalis） bulls used for artificial insemination （AI） under tropical conditions in Thailand, as it does in Bos taurus and Bos indicus. Methods： Clinical and andrological examinations, and monitoring of semen production and quality were carried out on five mature, healthy swamp buffalo AI bulls in Thailand from July 2004 to the end of June 2005. Sperm output, motility, morphology and plasma membrane integrity （PMI） were compared between three seasons of the year （rainy, i.e. July-October; winter, i.e. November-February; and summer, i.e. March-June） with distinct ambient temperature and humidity. Results： All bulls were diagnosed as clinically healthy and with good libido throughout the study. Ejaculate volume, pH, sperm concentration, total sperm number and initial sperm motility did not differ between seasons, whereas PMI and the relative proportion of morphologically normal spermatozoa were highest in summer and lowest in winter （P 〈 0.05）. Buffalo age, week of collection and season influenced sperm morphology （P 〈 0.05-0.001）. Among morphological abnormalities, only proportions of tail defects were affected by season, being highest in the rainy season and lowest in summer （P 〈 0.001）. In conclusion, climatic changes did not seem to largely affect semen sperm output or viability. Although the proportions of PMI and tail abnormalities were affected by season, they were always below what is considered unacceptable for AI bull sires. Conclusion： Seasonal changes did not appear to cause deleterious changes in sperm quality in swamp buffalo AI-sires in tropical Thailand.