Nascently generated microplastics in freshwater stream are colonized by bacterial communities from stream and riparian sources.

The purpose of this study was to examine bacterial colonization of different types of microplastics through time in a freshwater ecosystem. Microplastics are persistent pollutants in aquatic ecosystems. Bacteria readily colonize microplastic surfaces and may contribute to their degradation, but the taxa involved, and their degradative abilities, differ based on factors such as microplastic chemistry, plastic age, and specific ecosystem types.

Measurement of protein concentration in bacteria and small organelles under a light transmission microscope.

Protein concentration (PC) is an essential characteristic of cells and organelles; it determines the extent of macromolecular crowding effects and serves as a sensitive indicator of cellular health. A simple and direct way to quantify PC is provided by brightfield-based transport-of-intensity equation (TIE) imaging combined with volume measurements. However, since TIE is based on geometric optics, its applicability to micrometer-sized particles is not clear.

Calculated Medicine: Seven Decades of Accelerating Growth.

The field of Calculated Medicine has grown substantially over the last 7 decades. Comprised of objective, evidence-based medical decision tools, Calculated Medicine has broad application in medical practice, medical research, and health care management. This article reviews the history and varied methodologies of Calculated Medicine, starting with the 1953 Apgar score and concluding with a look into modern computational tools of the field: machine learning, natural language processing, artificial intelligence, and in silico research techniques.

Detecting antibiotic resistance genes in anthropogenically impacted streams and rivers.

Streams and rivers are widely impacted by human activities ranging from hydrological modifications to point and nonpoint pollution. Among the pollutants that enter lotic ecosystems are pharmaceuticals and personal care products, including antibiotics, that may play a role in the occurrence of antibiotic resistance genes (ARGs). Oftentimes, ARGs are detected based on culturing of bacteria or by using quantitative polymerase chain reaction; the limitations of these methods create barriers to our understanding.

Fighting Prejudice and Absorbing Refugees From Nazism: The National Committee for the Resettlement of Foreign Physicians, 1939-1945.

In the 1930s and 1940s, the medical profession reacted with hostility and erected formidable barriers to refugee physicians from Nazi-dominated Europe who sought to practice medicine in the United States. Yet, refugee physicians ultimately succeeded, with 77% of them working as doctors by 1945 and 98.6% by 1947.

Distribution and co-occurrence of antibiotic and metal resistance genes in biofilms of an anthropogenically impacted stream.

Urban stream biofilms are potential hotspots for resistomes and antibiotic resistance genes (ARGs). Biofilm communities that harbor resistance genes may be influenced by contaminant input (e.g.

Microplastic surface properties affect bacterial colonization in freshwater.

Microplastics are a global concern in aquatic ecology and are readily colonized by bacteria in the environment. There is a lack of information on bacterial colonization of eroded and un-eroded microplastics in freshwater. In this study, six types of microplastics were incubated for 8 weeks in microcosms with water from Lake Erie.

Sediment bacteria in an urban stream: Spatiotemporal patterns in community composition.

Sediment bacterial communities play a critical role in biogeochemical cycling in lotic ecosystems. Despite their ecological significance, the effects of urban discharge on spatiotemporal distribution of bacterial communities are understudied. In this study, we examined the effect of urban discharge on the spatiotemporal distribution of stream sediment bacteria in a northeast Ohio stream.

Initial nitrogen enrichment conditions determines variations in nitrogen substrate utilization by heterotrophic bacterial isolates.

Background: The nitrogen (N) cycle consists of complex microbe-mediated transformations driven by a variety of factors, including diversity and concentrations of N compounds. In this study, we examined taxonomic diversity and N substrate utilization by heterotrophic bacteria isolated from streams under complex and simple N-enrichment conditions.

Results: Diversity estimates differed among isolates from the enrichments, but no significant composition were detected.

Denitrification in agriculturally impacted streams: seasonal changes in structure and function of the bacterial community.

Denitrifiers remove fixed nitrogen from aquatic environments and hydrologic conditions are one potential driver of denitrification rate and denitrifier community composition. In this study, two agriculturally impacted streams in the Sugar Creek watershed in Indiana, USA with different hydrologic regimes were examined; one stream is seasonally ephemeral because of its source (tile drainage), whereas the other stream has permanent flow. Additionally, a simulated flooding experiment was performed on the riparian benches of the ephemeral stream during a dry period.

Anticonvulsant medication use for the management of pain following spinal cord injury: systematic review and effectiveness analysis.

Study Design: Systematic review and effectiveness analysis.

Objectives: Assess the effectiveness of anticonvulsants for the management of post spinal cord injury (SCI) neuropathic pain.

Setting: Studies from multiple countries were included.

Impacts of labile organic carbon concentration on organic and inorganic nitrogen utilization by a stream biofilm bacterial community.

In aquatic ecosystems, carbon (C) availability strongly influences nitrogen (N) dynamics. One manifestation of this linkage is the importance in the dissolved organic matter (DOM) pool of dissolved organic nitrogen (DON), which can serve as both a C and an N source, yet our knowledge of how specific properties of DOM influence N dynamics are limited. To empirically examine the impact of labile DOM on the responses of bacteria to DON and dissolved inorganic nitrogen (DIN), bacterial abundance and community composition were examined in controlled laboratory microcosms subjected to various combinations of dissolved organic carbon (DOC), DON, and DIN treatments.

Effects of remediation on the bacterial community of an acid mine drainage impacted stream.

Acid mine drainage (AMD) represents a global threat to water resources, and as such, remediation of AMD-impacted streams is a common practice. During this study, we examined bacterial community structure and environmental conditions in a low-order AMD-impacted stream before, during, and after remediation. Bacterial community structure was examined via polymerase chain reaction amplification of 16S rRNA genes followed by denaturing gradient gel electrophoresis.

Effect of modeled reduced gravity conditions on bacterial morphology and physiology.

Background: Bacterial phenotypes result from responses to environmental conditions under which these organisms grow; reduced gravity has been demonstrated in many studies as an environmental condition that profoundly influences microorganisms. In this study, we focused on low-shear stress, modeled reduced gravity (MRG) conditions and examined, for Escherichia coli and Staphlyococcus aureus, a suite of bacterial responses (including total protein concentrations, biovolume, membrane potential and membrane integrity) in rich and dilute media and at exponential and stationary phases for growth. The parameters selected have not been studied in E.

Cultivable bacteria from ancient algal mats from the McMurdo Dry Valleys, Antarctica.

The McMurdo Dry Valleys in Antarctica are a favorable location for preservation of dormant microbes due to their persistent cold and dry climate. In this study, we examined cultivable bacteria in a series of algal mat samples ranging from 8 to 26539 years old. Cultivable bacteria were found in all samples except one (12303 years old), but abundance and diversity of cultivable bacteria decreased with increasing sample age.

Measurement of bacterial volume by transmission-through-dye imaging.

Transmission-through-dye (TTD) microscopy makes possible direct measurement of bacterial volume, irrespective of cell shape. The technique can be realized on any brightfield microscope and is applicable to bacteria of all shapes. TTD imaging requires that intact bacteria be immobilized on a flat transparent surface, such as a glass coverslip.

Placing the effects of leaf litter diversity on saprotrophic microorganisms in the context of leaf type and habitat.

Because of conflicting results in previous studies, it is unclear whether litter diversity has a predictable impact on microbial communities or ecosystem processes. We examined whether effects of litter diversity depend on factors that could confound comparisons among previous studies, including leaf type, habitat type, identity of other leaves in the mixture, and spatial covariance at two scales within habitats. We also examined how litter diversity affects the saprotrophic microbial community using terminal restriction fragment length polymorphism to profile bacterial and fungal community composition, direct microscopy to quantify bacterial biomass, and ergosterol extraction to quantify fungal biomass.

The effects of N:P ratio and nitrogen form on four major freshwater bacterial taxa in biofilms.

Bacteria in freshwater systems play an important role in nutrient cycling through both assimilatory and dissimilatory processes. Biotic and abiotic components of the environment affect these transformations as does the stoichiometry of the nutrients. We examined responses of four major taxa of bacteria in biofilms subjected to various N:P molar ratios using either nitrate or ammonium as a nitrogen source.

Bacterial communities of tyre monofill sites: growth on tyre shreds and leachate.

Aims: To investigate bacterial communities of tyre monofill sites, colonization of tyre material by bacteria and the effect of tyre leachate on bacteria.

Methods And Results: Culturable bacteria were isolated from buried tyre shreds and identified using fatty acid methyl ester analysis. Isolates belonged to taxonomic groups such as Bacilli, Actinobacteria, Clostridia, Flavobacteria, beta and gamma-proteobacteria.

Infliximab treatment shifts the balance between stimulatory and inhibitory Fcgamma receptor type II isoforms on neutrophils in patients with rheumatoid arthritis.

Objective: Human neutrophils express both activating and inhibitory Fcgamma receptors (FcgammaR), and their relative expression determines the inflammatory response to immune complexes. Tumor necrosis factor alpha (TNFalpha) up-regulates the expression of stimulatory FcgammaRIIa on neutrophils in vitro, and amplifies immune complex-induced activation of neutrophils in vivo. This study was undertaken to determine whether TNFalpha blockade in patients with rheumatoid arthritis (RA) alters the balance of activating FcgammaR and inhibitory FcgammaR and thereby decreases inflammation.

Bacterial communities of leachate from tire monofill disposal sites.

The disposal of used automobile tires is problematic due to the large number generated each year. Newer methods of tire disposal have been developed in which tires are shredded and used for construction materials or buried in dedicated tire monofill sites. In this study, the bacterial assemblage associated with aqueous leachate collected from tire monofill sites was examined and compared to the bacterial assemblage of reference streams.

Nutrients and other abiotic factors affecting bacterial communities in an Ohio River (USA).

Nitrogen and phosphorus additions from anthropogenic sources can alter the nutrient pool of aquatic systems, both through increased nutrient concentrations and changes in stoichiometry. Because bacteria are important in nutrient cycling and aquatic food webs, information about how nutrients affect bacterial communities enhances our understanding of how changes in nutrient concentrations and stoichiometry potentially affect aquatic ecosystems as a whole. In this study, bacterial communities were examined in biofilms from cobbles collected across seasons at three sites along the Mahoning River (Ohio) with differing levels of inorganic nutrient inputs.

Diversity of fungi, bacteria, and actinomycetes on leaves decomposing in a stream.

Although fungi, bacteria, and specific bacterial taxa, such as the actinomycetes, have been studied extensively in various habitats, few studies have examined them simultaneously, especially on decomposing leaves in streams. In this study, sugar maple and white oak leaves were incubated in a stream in northeastern Ohio for 181 days during which samples were collected at regular intervals. Following DNA extraction, PCR-denaturing gradient gel electrophoresis (DGGE) was performed using fungus-, bacterium-, and actinomycete-specific primers.