Prevalence, codetection and seasonal distribution of upper airway viruses and bacteria in children with acute respiratory illnesses with cough as a symptom

Most studies exploring the role of upper airway viruses and bacteria in paediatric acute respiratory infections (ARI) focus on specific clinicaldiagnoses and/or do not account for virus–bacteria interactions. We aimed to describe the frequency and predictors of virus and bacteria codetection in children with ARI and cough, irrespective of clinical diagnosis. Bilateral nasal swabs, demographic, clinical and risk factor data were collected at enrollment in children aged <15 years presenting to an emergency department with an ARI and where cough was a symptom. Swabs were tested by polymerase chain reaction for 17 respiratory viruses and seven respiratory bacteria. Logistic regression was used to investigate associations between child characteristics and codetection of the organisms of interest. Between December 2011 and August 2014, swabs were collected from 817 (93.3%) of 876 enrolled children, median age 27.7 months (interquartile range13.9–60.3 months). Overall, 740 (90.6%) of 817 specimens were positive for any organism. Both viruses and bacteria were detected in 423 specimens (51.8%). Factors associated with codetection were age (adjusted odds ratio (aOR) for age <12 months = 4.9, 95% confidence interval (CI) 3.0, 7.9; age 12 to <24 months = 6.0, 95% CI 3.7, 9.8; age 24 to <60 months = 2.4, 95% CI 1.5, 3.9), male gender (aOR 1.46; 95% CI 1.1, 2.0), child care attendance (aOR 2.0; 95% CI 1.4, 2.8) and winter enrollment (aOR 2.0; 95% CI 1.3, 3.0). Haemophilus influenzae dominated the virus–bacteria pairs. Virus–H. influenzae interactions in ARI should be investigated further, especially as the contribution of nontypeable H. influenzae to acute and chronic respiratory diseases is being increasingly recognized.

Vertical and seasonal distribution of phytoplankton in the Shen Reservoir Plateau State, Nigeria

The phytoplankton distribution of the Shen Reservoir, Bukuru in the Jos Plateau, Nigeria was monitored at 6 depths. Higher floral abundance occurred within the upper 00-03 meters with highest values at the first 1 meter. Bacillariophyceae and Dinophyceae recorded higher values in March-April with lower values in July and January respectively. Phytoplankton were most abundant in the rainy season. Secchi disc transparency was lowest in the peak of the rainy season (July) due to higher levels of suspended matter resulting from the increased run-off from surrounding farmlands of allochthonous materials as well as higher levels of phytoplankton population arising from the former factor. The low water temperature of December/January 15 degree C plus or minus 2 degree C might have depressed growth among the major groups of plankters but enhanced rapid multiplication of the Chlorophyta, Trachelomonas which showed a bloom at this season

An ecological study of seasonal distribution of Ostracoda, Solomons Island, Maryland, region

The determination of the distribution and seasonal fluctuations of ostracodes living in the littoral zone directly in front of the Chesapeake Biological Laboratory has been attempted in the present study. Samples taken in other parts of the Chesapeake Bay and around Solomons harbor, show that other species of ostracodes exist but these forms have not been considered in the two-year study here reported. The seasonal distribution of the species was compared with hydrographical records furnished for the same period by the Chesapeake Biological Laboratory in order to determine the correlation between ecological factors and seasonal fluctuations in numbers and species of Ostracoda.

Seasonal distribution, abundance, and growth of young-of-the-year Atlantic croaker (Micropogonias undulatus) in Delaware Bay and adjacent marshes

We examined the spatial and temporal distribution, abundance, and growth of young-of-the-year (YOY) Atlantic croaker (Micropogonias undulatus) in Delaware Bay, one of the northernmost estuaries in which they consistently occur along the east coast of the United States. Sampling in Delaware Bay and in tidal creeks in salt marshes adjacent to the bay with otter trawls, plankton nets and weirs, between April and November 1996–99, collected approximately 85,000 YOY. Ingress of each year class into the bay and tidal creeks consistently occurred in the fall, and the first few YOY appeared in August. Larvae as small as 2–3 mm TL were collected in September and October 1996. Epibenthic individuals <25 mm TL were present each fall and again during spring of each year, but not in 1996 when low water temperatures in January and February apparently caused widespread mortality, resulting in their absence the following spring and summer. In 1998 and 1999, a second size class of smaller YOY entered the bay and tidal creeks in June. When YOY survived the winter, there was no evidence of growth until after April. Then the YOY grew rapidly through the summer in all habitats (0.8–1.4 mm/d from May through August). In the bay, they were most abundant from June to August over mud sediments in oligohaline waters. They were present in both subtidal and intertidal creeks in the marshes where they were most abundant from April to June in the mesohaline portion of the lower bay. The larger YOY began egressing out of the marshes in late summer, and the entire year class left the tidal creeks at lengths of 100–200 mm TL by October or November when the next year class was ingressing. These patterns of seasonal distribution and abundance in Delaware Bay and the adjacent marshes are similar to those observed in more southern estuaries along the east coast; however, growth is faster—in keeping with that in other northern estuaries.

Effects of environmental conditions on the seasonal distribution of phytoplankton biomass in the North Sea

We study the spatial and seasonal variability of phytoplankton biomass (as phytoplankton color) in relation to the environmental conditions in the North Sea using data from the Continuous Plankton Recorder survey. By using only environmental fields and location as predictor variables we developed a nonparametric model (generalized additive model) to empirically explore how key environmental factors modulate the spatio-temporal patterns of the seasonal cycle of algal biomass as well as how these relate to the ,1988 North Sea regime shift. Solar radiation, as manifest through changes of sea surface temperature (SST), was a key factor not only in the seasonal cycle but also as a driver of the shift. The pronounced increase in SST and in wind speed after the 1980s resulted in an extension of the season favorable for phytoplankton growth. Nutrients appeared to be unimportant as explanatory variables for the observed spatio-temporal pattern, implying that they were not generally limiting factors. Under the new climatic regime the carrying capacity of the whole system has been increased and the southern North Sea, where the environmental changes have been more pronounced, reached a new maximum.

Radioautographic study of the seasonal distribution of leukocytes in turtles Phrynops hilarii (Chelonia Chelidae)

The aim of this study was to present a morphological description of the leukocytes of Phrynops hilarii turtles according to the seasonal distribution of these cells and to show their replacement in the blood circulation using a radioautographic method. Five animals of both sexes weighing 600-1200 g were used. The animal's blood was aspirated, smeared on glass slides, and stained with the Romanowsky stain, and 500 cells of each animal were counted during each season. The results obtained were analyzed statistically by analysis of variance followed by the Bonferrom test (NCSS), with the level of significance set at p < 0.05. The radioautographic analysis of turtle blood exposed to 1000 mu Ci of H-3-thymidine and developed after 30 days showed a large number of silver grains incorporated into the cells, except for basophils, with cell renewal occurring every seven days. Quantitative data demonstrated a seasonal influence on the distribution of some leukocyte types, with the following p values: heterophils (p = 0.0007), basophils (p = 0.0002), monocytes (p = 0.0016), eosinophils (p = 0.0073). However, using this statistical method, it was not possible to detect a significant difference related to seasonal influence on lymphocytes (p = 0. 16295) or thrombocytes (p = 0. 1046). Using this experimental animal model, a seasonal influence on the distribution of some leukocyte types was observed, and the radioautographic method revealed a cell renewal system occurring every seven days, except for basophils. (C) 2008 Elsevier Ltd. All rights reserved.

Reproductive biology and seasonal distribution of Mustelus schmitti (Elasmobranchii : Triakidae) in the Rio de la Plata oceanic front, south-western Atlantic

The population structure and reproductive biology of Mustelus schmitti was analysed during autumn (1994, 1995) and spring (1994) in the Rio dc la Plata occanic front. The samples consisted mainly of a adult males and immature females, indicating that nursery areas are Situated elsewhere. In autumn, the highest female densities occurred between 36 degrees S and 35 degrees S, with densities decreasing further south, and high male densities occurred over all latitudes of the study area. In Spring, both Sexes occurred north of latitude 36 degrees 30 degrees S. Males attained Maturity at. 59 cm total length (TL), and females at 72 cmTL Litter size varied From one to ten in spring and two to nine in autumn, With embryos ranging from 9 to 26 cm and 7 to 26 cm TL respcctivcly the mean TL of embryos was significantly higher in spring (22 cm), suggesting that parturition Occurs ill late spring and summer. Litter size was found to Increase with female TL..