Microbiomes Reduce Their Host's Sensitivity to Interspecific Interactions.

Bacteria associated with eukaryotic hosts can affect host fitness and trophic interactions between eukaryotes, but the extent to which bacteria influence the eukaryotic species interactions within trophic levels that modulate biodiversity and species coexistence is mostly unknown. Here, we used phytoplankton, which are a classic model for evaluating interactions between species, grown with and without associated bacteria to test whether the bacteria alter the strength and type of species interactions within a trophic level. We demonstrate that host-associated bacteria alter host growth rates and carrying capacity. This did not change the type but frequently changed the strength of host interspecific interactions by facilitating host growth in the presence of an established species. These findings indicate that microbiomes can regulate their host species' interspecific interactions. As between-species interaction strength impacts their ability to coexist, our findings show that microbiomes have the potential to modulate eukaryotic species diversity and community composition.IMPORTANCE Description of the Earth's microbiota has recently undergone a phenomenal expansion that has challenged basic assumptions in many areas of biology, including hominid evolution, human gastrointestinal and neurodevelopmental disorders, and plant adaptation to climate change. By using the classic model system of freshwater phytoplankton that has been drawn upon for numerous foundational theories in ecology, we show that microbiomes, by facilitating their host population, can also influence between-species interactions among their eukaryotic hosts. Between-species interactions, including competition for resources, has been a central tenet in the field of ecology because of its implications for the diversity and composition of communities and how this in turn shapes ecosystem functioning

The burden of minimal hepatic encephalopathy: from diagnosis to therapeutic strategies

Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE). It affects the performance of psychometric tests focused on attention, working memory, psychomotor speed, and visuospatial ability, as well as electrophysiological and other functional brain measures. MHE is a frequent complication of liver disease, affecting up to 80% of tested patients. By being related to falls, an impairment in fitness to drive and the development of overt HE, MHE severely affects the lives of patients and caregivers by altering their quality of life and their socioeconomic status. MHE is detected in clinically asymptomatic patients using appropriate psychometric tests and neurophysiological methods that highlight neuropsychological alterations, such as video-spatial orientation deficits, attention disorders, memory, reaction times, electroencephalogram slowing, prolongation of latency-evoked cognitive potentials, and reduction in the critical flicker frequency. Several treatments have been proposed for MHE treatment, including non-absorbable disaccharides, poorly absorbable antibiotics such as rifaximin, probiotics and branched-chain amino acids. However, because of the multiple diagnosis methods, the various endpoints of treatment trials and the variety of agents used in trials, the treatment of MHE is not currently recommended as routine, but only on a case-by-case basis

Interactive Video Vignettes (IVVs) to Help Students Learn Genetics Concepts

any video resources exist to teach Mendelian genetics, but most consist of passive delivery of information rather than active construction of knowledge by users. We have created two interactive video vignettes (IVVs) that can be used together or separately to introduce students to core concepts of genetics, using principles of active learning (e.g., elicit-confront-resolve, directed feedback, reflection). These online resources are free and can be assigned as homework for students to complete outside of class. Each IVV features a realistic scenario of undergraduate students investigating genetic phenomena by collecting and analyzing data. During the IVVs, the user is integrated into the process, answers conceptual questions, receives feedback based on their answers, and reflects on the experience by comparing their original ideas to their new understandings. Marfamily is primarily designed to teach pedigree construction and analysis, while A Matter of Taste addresses common misconceptions about dominance. Both also demonstrate the scientific method. Users cannot advance without answering the questions, although they can review past scenes. Resources for both formative and summative assessment are provided. The IVV is easily integrated into any course where an introduction to or review of basic genetics is needed

An Online Interactive Video Vignette that Helps Students Learn Key Concepts of Fermentation and Respiration

Topics related to energy transformation and metabolism are important parts of an undergraduate biology curriculum, but these are also topics that students traditionally struggle with. To address this, we have created a short online Interactive Video Vignette (IVV) called To Ferment or Not to Ferment: That is the Question. This IVV is designed to help students learn important ideas related to cellular respiration and metabolism. Students in various courses across four institutions were assigned the IVV as an out-of-class preinstruction homework assignment. To test the effectiveness of this IVV on student learning, we collected and analyzed data from questions embedded in the IVV, open response reflection questions, and pre- and postassessments from IVV watchers and nonwatchers. Our analysis revealed that students who completed the IVV activity interacted productively with this online tool and made significant learning gains on important topics related to cellular respiration and metabolism. This IVV is freely available via https://www.rit.edu/cos/interactive/MINT for instructors to adopt for class use

Evidence of cytotoxic activity against mammalian red blood cell of Na+ channel neurotoxin (AE1) from sea anemone (actinia equina)

The diversification of anthozoan toxins played an important role in the ability to colonize various ecological niches. In this study we evaluated the hemolytic activity of HPLC separated fraction of tentacle extracts of sea anemone Actinia equina. Toxic components from acid tissue tentacle extracts were investigated by size exclusion and reverse phase HPLC to characterize cytolytic molecules. A novel low molecular weight active fraction was sequenced by MALDI TOF analysis and a protein correspondent to 5.4 kDa Sodium channel neurotoxin (Ae1) from A. equina was identified. Synthetic Ae1 was assayed and it showed an hemolytic activity against mammalian erythrocytes in a dose dependent manner. Cytolytic activity in addition to neuro-inhibitory function could be a further property of Ae1 toxin repertoire

Longitudinal investigation of Salmonella spp. from farm to fork in the pig industry in Reunion Island

Salmonella is, after Campylobacter, the most reported zoonotic pathogen in Europe. Pork meat is frequently incriminated in salmonellosis. However, asymptomatic carrying of Salmonella by pigs makes its detection difficult. Despite its tropical situation, pig industry of Reunion Island is also concerned by this public health burden

Prevalence and risk indicators associated with Salmonella infection in farrow-to-finish farm in Reunion Island

Salmonella is the second cause of foodborne diseases in France and pork products are regularly incriminated. For the implementation of control measures in farms, it is necessary to better understand the risks of infection of pigs by Salmonella at farms. Our epidemiological study aims to determine Salmonella prevalence of fattening pigs in Reunion Island, oversea territory of France, and the main risk indicators for pig infection. Fifty farms (farrow-to finish and multiplier) were randomly selected and visited 4 times: at slaughtered previous batch, after cleaning and disinfection, beginning and end of the fattening period for the studied batch. Pools of fresh faeces, gauze socks and gauze swabs were sampled to assess the bacteriological status of these pig farms. A questionnaire was submitted to farmers and analysed for the further identification of risk indicators

Evolution of Ciona intestinalis Tumor necrosis factor alpha (CiTNFα): Polymorphism, tissues expression, and 3D modeling

Although the Tumor necrosis factor gene superfamily seems to be very conserved in vertebrates, phylogeny, tissue expression, genomic and gene organization, protein domains and polymorphism analyses showed that a strong change has happened mostly in invertebrates in which protochordates were a constraint during the immune-molecules history and evolution. RT PCR was used to investigate differential gene expression in different tissues. The expression shown was greater in the pharynx. Single-nucleotide polymorphism has been investigated in Ciona intestinalis Tumor necrosis factor alpha (CiTNFα) mRNA isolated from the pharynx of 30 ascidians collected from Licata, Sicily (Italy), by denaturing gradient gel electrophoresis (DGGE). For this analysis, CiTNFα nucleotide sequence was separated into two fragments, TNF-1 and -2, respectively, of 630 and 540 bp. We defined 23 individual DGGE patterns (named 1 to 10 for TNF-1 and 1 to 13 for TNF-2). Five patterns for TNF-1 accounted for <10% of the individuals, whereas the pattern 13 of TNF-2 accounted for >20% of the individuals. All the patterns were verified by direct sequencing. Single base-pair mutations were observed mainly within COOH-terminus, leading to 30 nucleotide sequence variants and 30 different coding sequences segregating in two main different clusters. Although most of the base mutations were silent, four propeptide variants were detected and six amino acid replacements occurred within COOH-terminus. Statistical tests for neutrality indicated negative selection pressure on signal and mature peptide domains, but possible positive selection pressure on COOH-terminus domain. Lastly we displayed the in silico 3D structure analysis including the CiTNFα variable region

Computed tomography of solitary fibrous tumor of the pleura abutting the mediastinum: A diagnostic challenge

Background: Solitary fibrous tumor of the pleura (SFTP) arising from the mediastinal pleura may be confused with primary mediastinal tumors. We studied the computerized tomographic (CT) findings of patients with SFTP that could suggest a diagnosis of SFTP. Materials and Methods: At our hospital from January 1995 to June 2012, 39 patients with histologically confirmed SFTP were surgically treated; seven of them abutting the mediastinal pleura. The study group included seven patients aged between 53 and 81 years. Baseline CT scans were retrospectively reviewed to identify radiological findings suggestive of SFTP including: (1) smooth and sharply delineated contours; (2) obtuse, acute, or tapering angles between the lesion and the mediastinum depending on the size; (3) homogeneous soft-tissue attenuation; (4) “geographic pattern” due to the contemporary presence of large vessels, necrosis, and calcifications; (5) displacement of the lung parenchyma; (6) presence of a cleavage plane; and (7) absence of lymphadenopathy or pleural methastasis. Results: All tumors formed acute angles with the pleura. Six out of the seven presented smoothly tapering margins, three had a “geographic pattern” of attenuation and displaced the anterior junction line; one showed an outside junction line development. Four cases had a clear pleural origin. Conclusions: The possibility of SFTP should be taken into account when a mass abuts the mediastinum projecting inside the thoracic cavity in the presence of an intense and “geographical pattern” of enhancement without lymphoadenopathy or pleural metastasis. These findings assume greater significance in the presence of discrepancy between the size of the lesion and the clinical presentation