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Understanding the ecological function of developed large rivers remains elusive because these systems have long been altered for multiple uses. In particular, floodplains of large rivers, such as the Mississippi River, have been contained behind extensive levees. A historic flood occurred in the lower Mississippi River system during spring of 2011, prompting the US Army Corps of Engineers to activate the Bird's Point-New Madrid floodway, a 55 000-ha, agriculturally dominated, leveed area. Water entered the floodway at flows >1 m s−1 through two crevasses created in the upper portion of the levee and exited through a crevasse at the lower end. During the month, the floodway was inundated; we quantified discharge, water chemistry, primary production and fish production in the floodway and the adjacent river. Water entering the floodway was retained <1.3 d, and nutrient concentrations were not elevated in the floodway beyond those in the river, despite expected contributions from a legacy of fertilization. Primary production equaled respiration in the floodway, while the adjacent river was heterotrophic. Gizzard shad and freshwater drum were more abundant in the floodway than the river, while channel catfish were more abundant in the river. Growth rates of young native fishes, normalized for temperature, were the same in the floodway and the river, with the exception of gizzard shad, which grew faster in the floodway. Fish community structure, especially in the lower floodway, was temporally and spatially dynamic. Even though it has been heavily modified for agriculture, the floodway provided benefits, albeit limited, to the Mississippi River. With multifunctional management and strategic planning, systems such as these may provide substantial services such as flood abatement, nutrient transformation and fish production in the Mississippi River basin and potentially reduce nutrient loading downstream in areas such as the Gulf of Mexico. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The natural flow regime of rivers has been altered throughout the world in a variety of ways, with many alterations resulting in reduced flows. While restoring impaired systems remains a societal imperative, a fundamental understanding of the effects of reduced flows on river ecosystem structure and function is needed to refine restoration goals and guide implementation. We quantified the effects of chronic low flows on snag-dwelling macroinvertebrate community structure and production in a low-gradient river. Macroinvertebrates commonly associated with flowing water (e.g. passive filter-feeders (PFF)) and higher quality habitats (e.g. Ephemeroptera, Plecoptera and Trichoptera (EPT)) had significantly higher abundance and biomass, and showed trends of higher production, in faster flowing reaches upstream of a hydrologic disconnection created by a drainage ditch. The presence of EPT and PFF groups resulted in a significantly more diverse community composed of larger-sized individuals compared with downstream, low-flow reaches, where smaller-bodied taxa (e.g. small crustaceans), and groups reflective of degraded conditions (e.g. Oligochaeta, Isopoda and Chironomidae) dominated production. Multivariate analyses suggested that differences between these two disparate communities were driven by water velocity and organic matter resources. Mean estimates of total community production did not differ significantly between the two reaches, however, there were areas in low-flow reaches that attained high secondary production because of patchily distributed and highly productive chironomids. Results demonstrate that long-term reductions in flows, even in a low-gradient river, can lead to significant shifts in macroinvertebrate communities, ultimately influencing energy flow pathways in stream food webs. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Analyses of 21 15N stable isotope tracer experiments, designed to examine food web dynamics in streams around the world, indicated that the isotopic composition of food resources assimilated by primary consumers (mostly invertebrates) poorly reflected the presumed food sources. Modeling indicated that consumers assimilated only 33-50% of the N available in sampled food sources such as decomposing leaves, epilithon, and fine particulate detritus over feeding periods of weeks or more. Thus, common methods of sampling food sources consumed by animals in streams do not sufficiently reflect the pool of N they assimilate. Isotope tracer studies, combined with modeling and food separation techniques, can improve estimation of N pools in food sources that are assimilated by consumers. Food web studies that use putative food samples composed of actively cycling (more readily assimilable) and refractory (less assimilable) N fractions may draw erroneous conclusions about diets, N turnover, and trophic linkages of consumers. By extension, food web studies using stoichiometric or natural abundance approaches that rely on an accurate description of food-source composition could result in errors when an actively cycling pool that is only a fraction of the N pool in sampled food resources is not accounted for. [ABSTRACT FROM AUTHOR]

A time-saving and cost-effective polymerase chain reaction (PCR)-based method was developed for species-specific detection of the scab pathogens (Streptomyces scabies and S. turgidiscabies) prevalent in potato (Solanum tuberosum) in northern Scandinavia. Species specificity of primers was verified using a collection of previously characterized Streptomyces strains isolated from potato scab lesions in Finland and Sweden. A total of 1245 scab lesions was tested from potato cvs Matilda and Sabina grown in the field in two geographic regions of Finland in 2000 and 2001. Freshly harvested or stored potato tubers were incubated at room temperature (18–21°C) under humid conditions for a few days. Bacterial growth was collected from scab lesions for DNA isolation and PCR. The two scab pathogens were detected in the same potato fields, tubers and scab lesions. The relative incidence of S. scabies was high in freshly harvested tubers but was much lower than that of S. turgidiscabies following storage. Both pathogens were seed-transmitted in Matilda and Sabina after 24 weeks of storage at 4°C. [ABSTRACT FROM AUTHOR]

Aim: To investigate the usefulness of the National Emergency X-Radiography Utilization Study (NEXUS) II head trauma decision rule in clinical practice for paediatric patients in a tertiary university hospital serving as the only paediatric hospital in the area., Methods: We compared how doctors evaluated and examined patients with head injury during two time periods, before and after the introduction of NEXUS II decision rule. Multiple implementation strategies were used as follows: education, tutoring and written instructions for the use of NEXUS II., Results: Two hundred and forty-four head injury patients visited the hospital before and 385 after the introduction of the NEXUS II decision rule. The number of hospital admissions (56%) and the mean duration of hospitalisation (2.5 days) remained the same during the two periods. In the NEXUS II evaluated group, there was a decrease of 40% in the number of hospital admissions. NEXUS II was applied in only 62 (16%) cases. The number of head imaging procedures remained the same. No patients with a clinically significant head injury were missed with the NEXUS II evaluation., Conclusion: NEXUS II was ineffective as our implementation failed. When used, NEXUS II reduced expenses in our study population by decreasing the number of hospital admissions., (© 2021 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.)

Background: Disappearance of middle ear effusion is one of the most important outcomes in the treatment of acute otitis media (AOM)., Aim: To evaluate the duration of effusion in AOM treated by antimicrobials and to find factors influencing it., Methods: Parents of 90 children with AOM monitored daily the disappearance of effusion with tympanometry. The children were randomly allocated to be treated with either oral amoxicillin or cefuroxime-axetil for 10 d. Daily monitoring lasted for 14 d or until the tympanogram was normal (curve A or C) in both ears. Pneumatic otoscopy was carried out every 2 wk., Results: Normal tympanograms were obtained after a median time of 7.5 d (range 1-58 d) among 75 successfully monitored patients. In two-thirds (69%) of them, effusion resolved in 14 d. The median duration of effusion did not differ significantly between the two treatment groups (8 vs 7 days, p=0.7). The children who had unilateral AOM cured more rapidly than those with bilateral AOM (5 vs 19 d, p<0.001). In logistic regression analysis adjusted for age, bilaterality explained treatment failure at 2 wk with an odds ratio of 28.1 (95% CI 4.6-169.5, p<0.001)., Conclusion: The choice of antimicrobials did not influence the duration of middle ear effusion, which was much shorter than had been thought previously. Children with unilateral AOM were cured much more quickly than those with bilateral AOM.