Impacts of wastewater treatment plants on benthic macroinvertebrate communities in summer and winter.

Treated effluent from municipal wastewater treatment plants (WWTPs) is a major source of contamination that can impact population size, community structure, and biodiversity of aquatic organisms. However, because the majority of field research occurs during warmer periods of the year, the impacts of wastewater effluent on aquatic communities during winter has largely been neglected. In this study, we assessed the impacts of wastewater effluent on aquatic benthic macroinvertebrate (benthos) communities along the effluent gradients of two WWTPs discharging into Hamilton Harbour, Canada, during summer and winter using artificial substrates incubated for 8 weeks.

Hydrologic flushing rates drive nitrogen cycling and plant invasion in a freshwater coastal wetland model.

Coastal wetlands intercept significant amounts of nitrogen (N) from watersheds, especially when surrounding land cover is dominated by agriculture and urban development. Through plant uptake, soil immobilization, and denitrification, wetlands can remove excess N from flow-through water sources and mitigate eutrophication of connected aquatic ecosystems. Excess N can also change plant community composition in wetlands, including communities threatened by invasive species.

Acute diverticulitis: an ongoing economic burden on the health system.

Background: Acute diverticulitis (AD) is an increasingly common cause of acute hospital admissions. An understanding of its economic burden is necessary to plan resource allocation, and for targeting health research funding. The aim of this study is to obtain an accurate estimate of the cost of AD, accounting not only for the initial episode, but all related costs incurred during long-term follow-up.

Forest structure, diversity, and primary production in relation to disturbance severity.

Differential disturbance severity effects on forest vegetation structure, species diversity, and net primary production (NPP) have been long theorized and observed. Here, we examined these factors concurrently to explore the potential for a mechanistic pathway linking disturbance severity, changes in light environment, leaf functional response, and wood NPP in a temperate hardwood forest.Using a suite of measurements spanning an experimental gradient of tree mortality, we evaluated the direction and magnitude of change in vegetation structural and diversity indexes in relation to wood NPP.

Satellite-based decadal change assessments of pan-Arctic environments.

Remote sensing can advance the work of the Circumpolar Biodiversity Monitoring Program through monitoring of satellite-derived terrestrial and marine physical and ecological variables. Standardized data facilitate an unbiased comparison across variables and environments. Using MODIS standard products of land surface temperature, percent snow covered area, NDVI, EVI, phenology, burned area, marine chlorophyll, CDOM, sea surface temperature, and marine primary productivity, significant trends were observed in almost all variables between 2000 and 2017.

Error Measurement Between Anatomical Porcine Spine, CT Images, and 3D Printing.

Rationale And Objectives: 3D printers are increasingly used in medical applications such as surgical planning, creation of implants and prostheses, and medical education. For the creation of reliable 3D printed models of the vertebral column, processing must be performed on CT images. This processing must be assessed and validated so that any error of the printed model can be recognized and minimized.

Publication rates of, and attitudes toward, summer research projects: 10-year experience from a single institution in New Zealand.

Research is increasingly being emphasized from an early stage in medical students' careers. Medical student involvement in research and authorship of peer-reviewed manuscripts have been shown to enhance their academic performance-both in the short term and long term. The aim of this study was to evaluate outcomes and motivations of the summer studentship research program at our institution, using Vroom's expectancy theory as a conceptual framework.

Plant Size and Competitive Dynamics along Nutrient Gradients.

Resource competition theory in plants has focused largely on resource acquisition traits that are independent of size, such as traits of individual leaves or roots or proportional allocation to different functions. However, plants also differ in maximum potential size, which could outweigh differences in module-level traits. We used a community ecosystem model called mondrian to investigate whether larger size inevitably increases competitive ability and how size interacts with nitrogen supply.

Multi-scale heterogeneity in vegetation and soil carbon in exurban residential land of southeastern Michigan, USA.

Exurban residential land (one housing unit per 0.2-16.2 ha) is growing in importance as a human-dominated land use.

Neurosensory deficit following mandibular sagittal split osteotomy: A comparative study between positional screws and miniplates fixation.

This retrospective study compared the incidence of long-term inferior alveolar nerve injury for positional screws and miniplate fixation of bilateral sagittal split osteotomies carried out in 2 hospitals in Scotland. The study involved a mixture of mandibular setback and advancement surgery. The outcome of neurosensory deficit (NSD) was solely based on subjective assessment by the surgeons and patients' reported alteration in sensation.

A comparison of skin graft success in the head & neck with and without the use of a pressure dressing.

Background: The success of skin grafting is dependent on the interplay between many factors including nutrient uptake and vascular in-growth. To allow this, it is important that the graft is immobile and traditionally a 'pressure dressing' has been placed over the graft to improve outcome and graft 'take'. We present the findings of our comparative study of full-thickness skin grafts performed in the head, neck and face region over a period of 24 months.

Adiponectin deficit during the precarious glucose economy of early lactation in dairy cows.

In rodents and primates, insulin resistance develops during pregnancy and fades after parturition. In contrast, dairy cows and other ruminants maintain insulin resistance in early lactation (EL). This adaptation favors mammary glucose uptake, an insulin-independent process, at a time when the glucose supply is scarce.

Sinks for nitrogen inputs in terrestrial ecosystems: a meta-analysis of 15N tracer field studies.

Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched 15N isotope tracers in order to synthesize information about total ecosystem N retention (i.e.

Units of nature or processes across scales? The ecosystem concept at age 75.

The ecosystem has served as a central organizational concept in ecology for nearly a half century and continues to evolve. As a level in the biotic hierarchy, ecosystems are often viewed as ecological communities integrated with their abiotic environments. This has always been imperfect because of a mismatch of scales between communities and ecosystem processes as they are made operational for field study.

Shoaling preferences and the effects of sex ratio on spawning and aggression in small laboratory populations of zebrafish (Danio rerio).

Owing to a lack of basic information on the biology of zebrafish (Danio rerio), lab managers must often base decisions regarding the care and use of this species on anecdotal information. In an effort to provide researchers with context-specific behavioral information, the authors evaluated shoaling and spawning behaviors in small groups of zebrafish. In each shoaling assay, a fish was given a choice to shoal with either a single fish or a group of three fish.

Shoaling preferences of two common killifish (Fundulus heteroclitus and F. diaphanus) in the laboratory and in the field: a new analysis of heterospecific shoaling.

Heterospecific grouping behavior of mummichogs (Fundulus heteroclitus) and banded killifish (Fundulus diaphanus) was analyzed in the laboratory and in a freshwater tidal marsh in Cremona, Maryland. Several parameters of wild, intact shoals were measured, including species composition, body length, parasite load, gender, and any physical abnormalities. Fish collected were used for laboratory analysis of shoaling preferences.

Forest to reclaimed mine land use change leads to altered ecosystem structure and function.

The United States' use of coal results in many environmental alterations. In the Appalachian coal belt region, one widespread alteration is conversion of forest to reclaimed mineland. The goal of this study was to quantify the changes to ecosystem structure and function associated with a conversion from forest to reclaimed mine grassland by comparing a small watershed containing a 15-year-old reclaimed mine with a forested, reference watershed in western Maryland.

Pregnancy rates in lactating dairy cattle following supplementation of progesterone after artificial insemination.

Poor conception rates in highly productive lactating cattle is especially prevalent in large, intensively-managed commercial herds. One of the causative factors is sub-optimal pre-implantation embryonic development which appears to result from inadequate circulating concentrations of progesterone. In the present study, the efficacy of very modest progesterone supplementation, between Days 3.

Global-scale similarities in nitrogen release patterns during long-term decomposition.

Litter decomposition provides the primary source of mineral nitrogen (N) for biological activity in most terrestrial ecosystems. A 10-year decomposition experiment in 21 sites from seven biomes found that net N release from leaf litter is dominantly driven by the initial tissue N concentration and mass remaining regardless of climate, edaphic conditions, or biota. Arid grasslands exposed to high ultraviolet radiation were an exception, where net N release was insensitive to initial N.

Adenylyl cyclases in oocyte maturation: a characterization of AC isoforms in bovine cumulus cells.

Mammalian oocytes are arrested at the G(2)/M transition in the meiotic cell cycle. It is well known that a decrease in intraoocyte cAMP concentrations accompanies resumption of meiosis, but the precise trigger of this decrease remains a mystery. Follicular somatic cells are intimately coupled to the oocyte and are thought to transmit maturation signals to the oocyte in response to hormonal stimulation.