phylogatR: Phylogeographic data aggregation and repurposing.

Patterns of genetic diversity within species contain information the history of that species, including how they have responded to historical climate change and how easily the organism is able to disperse across its habitat. More than 40,000 phylogeographic and population genetic investigations have been published to date, each collecting genetic data from hundreds of samples. Despite these millions of data points, meta-analyses are challenging because the synthesis of results across hundreds of studies, each using different methods and forms of analysis, is a daunting and time-consuming task. It is more efficient to proceed by repurposing existing data and using automated data analysis. To facilitate data repurposing, we created a database (phylogatR) that aggregates data from different sources and conducts automated multiple sequence alignments and data curation to provide users with nearly ready-to-analyse sets of data for thousands of species. Two types of scientific research will be made easier by phylogatR: large meta-analyses of thousands of species that can address classic questions in evolutionary biology and ecology, and student- or citizen- science based investigations that will introduce a broad range of people to the analysis of genetic data. phylogatR enhances the value of existing data via the creation of software and web-based tools that enable these data to be recycled and reanalysed and increase accessibility to big data for research laboratories and classroom instructors with limited computational expertise and resources.

Delayed extubation in spine surgery is associated with increased postoperative complications and hospital episode-based resource utilization.

STUDY OBJECTIVE: To elucidate the association between delayed extubation, postoperative complications, and episode-based resource utilization. DESIGN: Retrospective Propensity-Matched Cohort Study. SETTING: Single Large Academic Medical Center. PATIENTS: The computerized anesthetic records of 17,223 patients undergoing spine surgery from January 2006 through November 2016 were reviewed for this study. The records of 11,421 patients met inclusion criteria for final analysis, with 527 subjects who had delayed extubation following their procedure. INTERVENTIONS: Delayed extubation, defined as patients not extubated prior to leaving the operating room. MEASUREMENTS: Computerized anesthetic records of spine surgery patients were analyzed retrospectively. Corresponding Medicare Severity Diagnosis Related Group numbers (MS-DRGs) were then identified, as well as associated lengths of stay and costs of care. We compared hospital-acquired International Classification of Diseases-9 (ICD-9) and ICD-10 postoperative complication codes linked to each record to assess differences in outcome. MAIN RESULTS: Increasing medical and surgical complexity is associated with delayed extubation. Using propensity score matching, delayed extubation was independently associated with a higher likelihood of any postoperative complication (Odds Ratio [OR]: 1.79; 95% Confidence Interval [CI]: 1.23-2.61); major complications (OR: 2.22; 95% CI: 1.31-3.76); prolonged length of hospital stay (Hazard Ratio [HR]: 0.82 (0.72, 0.95), p = 0.006); prolonged Intensive Care Unit (ICU) stay (HR: 0.68 (0.61, 0.76), p < 0.001); and were less likely to be discharged home (OR: 1.40 (1.02, 1.92), p = 0.036). Propensity score matching demonstrated that anesthesiologist handoff was not independently associated with any of the examined adverse outcomes. CONCLUSIONS: Delayed extubation after spine surgery was associated with a statistically significant increased incidence of postoperative complications as well as increased hospital episode-based resource utilization in the form of increased hospital length of stay, ICU length of stay, post-acute care at a facility, and higher cost of hospitalization. Although anesthesiologist handoff was associated with delayed extubation, it was not independently associated with postoperative complications when propensity score matching was applied.

PseudoFuN: Deriving functional potentials of pseudogenes from integrative relationships with genes and microRNAs across 32 cancers.

BACKGROUND: Long thought "relics" of evolution, not until recently have pseudogenes been of medical interest regarding regulation in cancer. Often, these regulatory roles are a direct by-product of their close sequence homology to protein-coding genes. Novel pseudogene-gene (PGG) functional associations can be identified through the integration of biomedical data, such as sequence homology, functional pathways, gene expression, pseudogene expression, and microRNA expression. However, not all of the information has been integrated, and almost all previous pseudogene studies relied on 1:1 pseudogene-parent gene relationships without leveraging other homologous genes/pseudogenes. RESULTS: We produce PGG families that expand beyond the current 1:1 paradigm. First, we construct expansive PGG databases by (i) CUDAlign graphics processing unit (GPU) accelerated local alignment of all pseudogenes to gene families (totaling 1.6 billion individual local alignments and >40,000 GPU hours) and (ii) BLAST-based assignment of pseudogenes to gene families. Second, we create an open-source web application (PseudoFuN [Pseudogene Functional Networks]) to search for integrative functional relationships of sequence homology, microRNA expression, gene expression, pseudogene expression, and gene ontology. We produce four "flavors" of CUDAlign-based databases (>462,000,000 PGG pairwise alignments and 133,770 PGG families) that can be queried and downloaded using PseudoFuN. These databases are consistent with previous 1:1 PGG annotation and also are much more powerful including millions of de novo PGG associations. For example, we find multiple known (e.g., miR-20a-PTEN-PTENP1) and novel (e.g., miR-375-SOX15-PPP4R1L) microRNA-gene-pseudogene associations in prostate cancer. PseudoFuN provides a "one stop shop" for identifying and visualizing thousands of potential regulatory relationships related to pseudogenes in The Cancer Genome Atlas cancers. CONCLUSIONS: Thousands of new PGG associations can be explored in the context of microRNA-gene-pseudogene co-expression and differential expression with a simple-to-use online tool by bioinformaticians and oncologists alike.

Patient-perceived surgical indication influences patient expectations of surgery for degenerative spinal disease.

OBJECTIVE: Patients frequently have misconceptions regarding diagnosis, surgical indication, and expected outcome following spinal surgery for degenerative spinal disease. In this study, we sought to understand the relationship between patient-perceived surgical indications and patient expectations. We hypothesized that patients reporting appendicular symptoms as a primary surgical indication would report a higher rate of having expectations met by surgery compared to those patients reporting axial symptoms as a primary indication. METHODS: Questionnaires were administered to patients who had undergone surgery for degenerative spinal disease at 2 tertiary care institutions. Questions assessed perception of the primary indication for undergoing surgery (radicular versus axial), whether the primary symptom improved after surgery, and whether patient expectations were met with surgery. Outcomes of interest included patient-reported symptomatic improvement following surgery and expectations met by surgery. Various factors were assessed for their relationship to these outcomes of interest. RESULTS: There were 151 unique survey respondents. Respondents were nearly split between having a patient-perceived indication for surgery as appendicular symptoms (55.6%) and axial symptoms (44.4%). Patient-perceived surgical indication being appendicular symptoms was the only factor predictive of patient-reported symptomatic improvement in our logistic regression model (OR 2.614; 95% CI 1.218-5.611). Patient-perceived surgical indication being appendicular symptoms (OR 3.300; 95% CI 1.575-6.944) and patient-reported symptomatic improvement (OR 33.297; 95% CI 12.186-90.979) were predictive of patients reporting their expectations met with surgery in both univariate and multivariate logistic regression modeling. CONCLUSIONS: We found that patient-reported appendicular symptoms as the primary indication for surgery were associated with a higher rate of both subjective improvement following surgery and having expectations met by surgery. Studies such as ours point to the fact that while performing technically superlative operations is paramount, it may be equally important to address other factors that help determine patient perception of the surgery experience.

Mechanical tension applied to substrate films specifies location of neuritogenesis and promotes major neurite growth at the expense of minor neurite development.

One obstacle in neural repair is facilitating axon growth long enough to reach denervated targets. Recent studies show that axonal growth is accelerated by applying tension to bundles of neurites, and additional studies show that mechanical tension is critical to all neurite growth. However, no studies yet describe how individual neurons respond to tensile forces applied to cell bodies and neurites simultaneously; neither do any test motor neurons, a phenotype critical to neural repair. Here we examine the growth of dissociated motor neurons on stretchable substrates. E15 spinal motor neurons were cultured on poly-lactide-co-glycolide films stretched at 4.8, 9.6, or 14.3 mm day(-1). Morphological analysis revealed that substrate stretching has profound effects on developing motor neurons. Stretching increases major neurite length; it also forces neuritogenesis to occur nearest poles of the cell closest to the sources of tension. Stretching also reduces the number of neurites per neuron. These data show that substrate stretching affects neuronal morphology by specifying locations on the cell where neuritogenesis occurs and favoring major neurite growth at the expense of minor neurites. These results serve as a building block for development of new techniques to control and improve the growth of neurons for nerve repair purposes.

Patient misconceptions concerning lumbar spondylosis diagnosis and treatment.

OBJECT Patient outcome measures are becoming increasingly important in the evaluation of health care quality and physician performance. Of the many novel measures currently being explored, patient satisfaction and other subjective measures of patient experience are among the most heavily weighted. However, these subjective measures are strongly influenced by a number of factors, including patient demographics, level of understanding of the disorder and its treatment, and patient expectations. In the present study, patients referred to a neurosurgery clinic for degenerative spinal disorders were surveyed to determine their understanding of lumbar spondylosis diagnosis and treatment. METHODS A multiple-choice, 6-question survey was distributed to all patients referred to a general neurosurgical spine clinic at a tertiary care center over a period of 11 months as a quality improvement initiative to assist the provider with individualized patient counseling. The survey consisted of questions designed to assess patient understanding of the role of radiological imaging in the diagnosis and treatment of low-back and leg pain, and patient perception of the indications for surgical compared with conservative management. Demographic data were also collected. RESULTS A total of 121 surveys were included in the analysis. More than 50% of the patients indicated that they would undergo spine surgery based on abnormalities found on MRI, even without symptoms; more than 40% of patients indicated the same for plain radiographs. Similarly, a large proportion of patients (33%) believed that back surgery was more effective than physical therapy in the treatment of back pain without leg pain. Nearly one-fifth of the survey group (17%) also believed that back injections were riskier than back surgery. There were no significant differences in survey responses among patients with a previous history of spine surgery compared with those without previous spine surgery. CONCLUSIONS These results show that a surprisingly high percentage of patients have misconceptions regarding the diagnosis and treatment of lumbar spondylosis, and that these misconceptions persist in patients with a history of spine surgery. Specifically, patients overemphasize the value of radiological studies and have mixed perceptions of the relative risk and effectiveness of surgical intervention compared with more conservative management. These misconceptions have the potential to alter patient expectations and decrease satisfaction, which could negatively impact patient outcomes and subjective valuations of physician performance. While these results are preliminary, they highlight a need for improved communication and patient education during surgical consultation for lumbar spondylosis.

Treatment of molluscum contagiosum in adult, pediatric, and immunodeficient populations.

BACKGROUND: Molluscum contagiosum is a viral infection of the skin that is widely considered to be a self-resolving disease that can be treated with benign neglect. However, the clinical reality is that the disease can vary widely by anatomic site and by recalcitrance to treatment and remains a significant cause of morbidity worldwide. OBJECTIVE: The purpose of this review was to compile an updated resource for clinicians that addresses the management of the broad spectrum of molluscum cases that may be encountered. METHODS: A comprehensive PubMed search was performed to identify publications on the treatment of molluscum infection, including presentations that may be rare or difficult. RESULTS: The specific clinical scenario of molluscum must be considered when selecting the optimal therapy because certain treatments can be more effective for specific patient subpopulations. CONCLUSION: Further attention must be directed toward standardizing treatment for molluscum infection based on patient age and immune status.

Futebol e a construção da imagem de treinadores pela mídia: um estudo a partir das notícias de um site de grande visitação na web / Soccer and the image construction of soccer coaches by the media: a study based on the news from a site of great visitation on the web / Lo fútbol y la construcción de la imagen de los entrenadores de fútbol por los medios de comunicación: un estudio a partir de las noticias de un sitio web de grande visitación

A relação entre esporte e mídia é indissociável nos dias de hoje. Assim, o presente estudo teve como objetivo quantificar o número de notícias sobre o futebol profissional masculino e analisar a construção da imagem do treinador. Para isso, foram coletadas todas as notícias esportivas de um site de grande visitação durante trinta dias. Concluiu-se que há, nesse site, um direcionamento das notícias para o futebol masculino profissional e seus treinadores, sendo que as ideias transmitidas sobre eles são principalmente ligadas a sua competência e à articulação tática/técnica da equipe.

The relationship between sport and media is inseparable today. Therefore, this study aimed to quantify the number of news reports about male professional soccer, and analyze the construction of the image associated with soccer coaches. To this end, every sports news from a largely accessed website was collected for 30 days. It was concluded that, in Brazil, these news are directed to male professional soccer and its coaches, with the ideas concerning the latter being mainly related to their competence and the tactical/technical articulation of the team.

La relación entre el deporte y los medios de comunicación es indivisible. Así siendo, el estudio presente tuvo como objetivos cuantificar el número de noticias sobre fútbol profesional masculino analizando la construcción de la imagen del entrenador. Para eso fueron recopiladas todas las noticias deportivas de una página web de grande visitación durante 30 días. Se concluyó que existe, en Brasil un direccionamiento de las noticias para el fútbol masculino profesional y sus entrenadores, siendo que las ideas transmitidas sobre estos son principalmente vinculadas a su competencia y a la articulación táctica/técnica del equipo.

Integrative assessment of selenium speciation, biogeochemistry, and distribution in a northern coldwater ecosystem.

For the past decade, considerable research has been conducted at a series of small lakes receiving treated liquid effluent containing elevated selenium (Se) from the Key Lake uranium (U) milling operation in northern Saskatchewan, Canada. Several studies related to this site, including field collections of water, sediment, and biota (biofilm and/or periphyton, invertebrates, fish, and birds), semicontrolled mesocosm and in situ caging studies, and controlled laboratory experiments have recently been published. The aim of the present investigation was to compile the site-specific information obtained from this multidisciplinary research into an integrative perspective regarding the influence of Se speciation on biogeochemical cycling and food web transfer of Se in coldwater ecosystems. Within lakes, approximately 50% of sediment Se was in the form of elemental Se, although this ranged from 0% to 81% among samples. This spatial variation in elemental Se was positively correlated with finer particles (less sand) and percent total organic C content in sediments. Other Se species detected in sediments included selenosulfides, selenite, and inorganic metal selenides. In contrast, the major Se form in sediment-associated biofilm and/or periphyton was an organoselenium species modeled as selenomethionine (SeMet), illustrating the critical importance of this matrix in biotransformation of inorganic Se to organoselenium compounds and subsequent trophic transfer to benthic invertebrates at the base of the food web. Detritus displayed a Se speciation profile intermediate between sediment and biofilm, with both elemental Se and SeMet present. In benthic detritivore (chironomid) larvae and emergent adults, and in foraging and predatory fishes, SeMet was the dominant Se species. The proportion of total Se present as a SeMet-like species displayed a direct nonlinear relationship with increasing whole-body Se in invertebrates and fishes, plateauing at approximately 70% to 80% of total Se as a SeMet-like species. In fish collected from reference lakes, a selenocystine-like species was the major Se species detected. Similar Se speciation profiles were observed using 21-day mesocosm and in situ caging studies with native small-bodied fishes, illustrating the efficient bioaccumulation of Se and use of these semicontrolled approaches for future research. A simplified conceptual model illustrating changes in Se speciation through abiotic and biotic components of lakes was developed, which is likely applicable to a wide range of northern industrial sites receiving elevated Se loading into aquatic ecosystems.

An in situ assessment of selenium bioaccumulation from water-, sediment-, and dietary-exposure pathways using caged Chironomus dilutus larvae.

An in situ caging study was conducted downstream of a metal mine in northern Canada to determine the significance of surface water versus sediment exposure on selenium (Se) bioaccumulation in the benthic invertebrate Chironomus dilutus. Laboratory-reared C. dilutus larvae were exposed to either site-specific whole-sediment and surface water or surface water only for 10 d at sites with differing sediment and Se characteristics. Results showed elevated whole-body Se concentrations in C. dilutus larvae when exposed to sediment and water, compared with larvae exposed to Se in the surface water only at concentrations ranging from <1 µg Se/L to 12 µg Se/L. In response to these findings, a second in situ experiment was conducted to investigate the importance of dietary Se (biofilm and detritus) versus whole-sediment-exposure pathways. Larvae exposed to sediment detritus had the highest Se concentrations after 10 d of exposure (15.6 ± 1.9 µg/g dry wt) compared with larvae exposed to whole-sediment (12.9 ± 1.7 µg/g dry wt) or biofilm (9.9 ± 1.6 µg/g dry wt). Detritus and biofilm appear to be enriched sources of organic Se, which are more bioaccumulative than inorganic Se. Midge larvae from the reference treatment contained elevated concentrations of diselenides (i.e., selenocystine), while larvae from the biofilm treatment had the highest concentrations of selenomethionine-like compounds, which may be a biomarker of elevated Se exposures derived from anthropogenic sources. Whenever possible, Se concentrations in the organic fraction of sediment should be measured separately from whole-sediment Se and used for more accurate ecological risk assessments of potential Se impacts on aquatic ecosystems.

Selective biodegradation of naphthenic acids and a probable link between mixture profiles and aquatic toxicity.

The toxicity of oil sands process-affected waters (OSPW) from the Athabasca Oil Sands (AOS) in northern Alberta, Canada, is related to a relatively persistent group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a complex mixture of carboxylic acids, with a general formula C(n)H(2n+Z)O2, where n indicates the carbon number and Z specifies the number of rings in the molecule. The present study is the first to evaluate the potential for the selective biodegradation of NAs and the associated reduction in aquatic toxicity of 2 OSPWs, maintained under 2 different hydraulic retention times and increased nutrient availability (nitrate and phosphate), using flow-through laboratory wetland microcosms over a 52-wk test period. High-performance liquid chromatography/quadrupole time of flight-mass spectrometry analysis was used to track the changes in NA mixture profiles, or "fingerprints," in each treatment over time. Based on first-order degradation kinetics, more rapid degradation was observed for NAs that had lower carbon numbers and fewer degrees of cyclization (NA congeners with carbon numbers 11-16 and Z series -2 to -4; half-lives between 19 and 28 wk). Within the NA mixture fingerprints, the 2 most persistent groups of homologues were also identified (NAs with carbon numbers 17-20 and Z series -6 to -12; half-lives between 37 and 52 wk). The persistence of this group of NAs may aid in explaining the residual chronic toxicological response as measured by the Microtox bioassay (effective concentration for 20%), after the degradation of the more labile fractions of NA mixtures in OSPW.

Degradation and aquatic toxicity of naphthenic acids in oil sands process-affected waters using simulated wetlands.

Oil sands process-affected waters (OSPWs) produced during the extraction of bitumen at the Athabasca Oil Sands (AOS) located in northeastern Alberta, Canada, are toxic to many aquatic organisms. Much of this toxicity is related to a group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a natural component of bitumen and are released into process water during the separation of bitumen from the oil sand ore by a caustic hot water extraction process. Using laboratory microcosms as an analogue of a proposed constructed wetland reclamation strategy for OSPW, we evaluated the effectiveness of these microcosms in degrading NAs and reducing the aquatic toxicity of OSPW over a 52-week test period. Experimental manipulations included two sources of OSPW (one from Syncrude Canada Ltd. and one from Suncor Energy Inc.), two different hydraulic retention times (HRTs; 40 and 400 d), and increased nutrient availability (added nitrate and phosphate). Microcosms with a longer HRT (for both OSPWs) showed higher reductions in total NAs concentrations (64-74% NAs reduction, p<0.05) over the test period, while nutrient enrichment appeared to have little effect. A 96 h static acute rainbow trout (Oncorhynchus mykiss) bioassay showed that the initial acute toxicity of Syncrude OSPW (LC50=67% v/v) was reduced (LC50>100% v/v) independent of HRT. However, EC20s from separate Microtox® bioassays were relatively unchanged when comparing the input and microcosm waters at both HRTs over the 52-week study period (p>0.05), indicating that some sub-lethal toxicity persisted under these experimental conditions. The present study demonstrated that given sufficiently long HRTs, simulated wetland microcosms containing OSPW significantly reduced total NAs concentrations and acute toxicity, but left behind a persistent component of the NAs mixture that appeared to be associated with residual chronic toxicity.

Highly Aligned Poly(3,4-ethylene dioxythiophene) (PEDOT) Nano- and Microscale Fibers and Tubes.

This study reports a facile method for the fabrication of aligned Poly(3,4-ethylene dioxythiophene) (PEDOT) fibers and tubes based on electrospinning and oxidative chemical polymerization. Discrete PEDOT nano- and microfibers and nano- and microtubes are difficult to fabricate quickly and reproducibly. We employed poly(lactide-co-glycolide) (PLGA) polymers that were loaded with polymerizable 3,4-ethylene dioxythiophene (EDOT) monomer to create aligned nanofiber assemblies using a rotating glass mandrel during electrospinning. The EDOT monomer/PLGA polymer blends were then polymerized by exposure to an oxidative catalyst (FeCl3). PEDOT was polymerized by continuously dripping a FeCl3 solution onto the glass rod during electrospinning. The resulting PEDOT fibers were conductive, aligned and discrete. Fiber bundles could be easily produced in lengths of several centimeters. The PEDOT sheath/PLGA core fibers were immersed in chloroform to remove the PLGA and any residual EDOT resulting in hollow PEDOT tubes. This approach made it possible to easily generate large areas of aligned PEDOT fibers/tubes. The structure and properties of the aligned assemblies were measured using optical microscopy, electron microscopy, Raman spectroscopy, thermal gravimetric analysis, and DC conductivity measurements. We also demonstrated that the aligned PEDOT sheath/PLGA core fiber assemblies could be used in supporting and directing the extension of dorsal root ganglia (DRG) neurons in vitro.

O técnico de judô: um estudo comparativo após 10 anos da regulamentação da Educação Física / The judo coach: a comparative study after 10 years of the Physical Education regulation

A regulamentação da profissão Educação Física, por meio da Lei 9.696 de 1o de setembro de 1998, deu origem a importantes reflexões a respeito do processo de formação dos instrutores/técnicos das modalidades de lutas/artes marciais e sua relação com a Educação Física. Neste contexto, Tavares Junior (2003) desenvolveu um estudo com o objetivo de investigar o estado da arte dos técnicos de judô do Estado de São Paulo durante o inicio do relacionamento entre os conselhos profissionais e as federações esportivas de lutas, incluindo os cursos de adequação profissional para provisionados que se encontravam em fase de finalização. Dessa maneira, nove anos após a realização do estudo de Tavares Junior (2003), a presente pesquisa objetivou investigar as mudanças decorrentes dos dez anos da formação do Conselho Regional de Educação Física do Estado de São Paulo (CREF 4 – SP), em relação aos dados iniciais da pesquisa realizada por Tavares Junior (2003), na perspectiva da observação longitudinal dos acontecimentos relacionados ao conhecimento e cultura dos técnicos da modalidade de judô no estado de São Paulo. Para tal finalidade, o questionário desenvolvido por Tavares Junior (2003) foi reaplicado em 22 técnicos de judô do interior do estado de São Paulo no ano em que o CREF 4 – SP completou 10 anos. Os resultados demostraram que houve um aumento no número de técnicos de judô graduados em Educação Física em comparação aos resultados apresentados por Tavares Junior (2003). Contudo, os conhecimentos práticos ou artesanais continuam se configurando como os mais importantes para a atuação destes técnicos. Não partimos do pressuposto que um conhecimento seja mais importante do que outro, porém, esperávamos que as mudanças de perfil, de empíricos para graduados em Educação Física, fizessem emergir uma fundamentação pedagógica e teórica diferenciada do que foi visto anteriormente por Tavares Junior (2003), fato que não ocorreu.

The Physical Education Regulation, achieved through the 9.969 Law of September the 1st of 1998, raised important reflections about the process of professional education of the instructors/coaches of martial arts modalities and their relation with the field of Physical Education. In this context, Tavares Junior (2003) developed a study with the objective of investigating the state of the art of judo coaches from the São Paulo State during the beginning of the relationship between professional councils and sports federations, including the courses of professional adequation for the provisioned, which were in the final phase. Thus, nine years after the development of Tavares Junior’s (2003) research, the present study had the objective of investigating the changes occurred as a result of ten years of the formation of the São Paulo State Physical Education Regional Council (PERC 4 – SP), in relation with the initial data from Tavares Junior’s (2003) research, in the perspective of the longitudinal observation of the events related with the knowledge and the culture of judo coaches in the São Paulo State. For this purpose, the questionnaire developed by Tavares Junior (2003) was reapplied to 22 judo coaches of the São Paulo State countryside in the year that PERC 4 – SP completed 10 years. The results showed that there was an increase in the number of judo coaches that are graduated in Physical Education in comparison with theresults presented by Tavares Junior (2003). However, the practical or artisanal kind of knowledge remains the most important to work as a judo coach. We were not assuming that one kind of knowledge is more important than another, but hoped that the profile changes, from empirical to graduated in Physical Education, could result in a pedagogical and theoretical grounding differentiated from that which was previously shown by Tavares Junior (2003), a fact that didn’t happen.

Selenium speciation and localization in chironomids from lakes receiving treated metal mine effluent.

A lake system in northern Saskatchewan receiving treated metal mine and mill effluent contains elevated levels of selenium (Se). An important step in the trophic transfer of Se is the bioaccumulation of Se by benthic invertebrates, especially primary consumers serving as a food source for higher trophic level organisms. Chironomids, ubiquitous components of many northern aquatic ecosystems, were sampled at lakes downstream of the milling operation and were found to contain Se concentrations ranging from 7 to 80 mgkg(-1)dry weight. For comparison, laboratory-reared Chironomus dilutus were exposed to waterborne selenate, selenite, or seleno-DL-methionine under laboratory conditions at the average total Se concentrations found in lakes near the operation. Similarities in Se localization and speciation in laboratory and field chironomids were observed using synchrotron-based X-ray fluorescence (XRF) imaging and X-ray absorption spectroscopy (XAS). Selenium localized primarily in the head capsule, brain, salivary glands and gut lining, with organic Se species modeled as selenocystine and selenomethionine being the most abundant. Similarities between field chironomids and C. dilutus exposed in the laboratory to waterborne selenomethionine suggest that selenomethionine-like species are most readily accumulated, whether from diet or water.

Thiel embalming technique: a valuable method for teaching oral surgery and implantology.

BACKGROUND: Because of its high requirements on surgical experience and the need of complete understanding of the anatomy, oral surgery and especially implantology belong to the most demanding procedures in dentistry. Therefore, hands-on courses for oral surgery and implantology are considered a prerequisite to prepare for clinical practice. To achieve teaching conditions as realistic as possible, we used a novel human cadaver embalming method enabling tissue dissection comparable with the living body. METHODS: Thirty cadavers which were offered by the Institute of Anatomy for the purpose of running oral surgery and implantology courses were embalmed in the technique described by Thiel. On each cadaver, dissection of soft and hard tissue and implantological procedures were performed according to a structured protocol by each course participant. The conservation of fine anatomical structures and the suitability of the embalmed tissue for dissecting, drilling, and suturing were observed and photographically documented. RESULTS: By means of the Thiel embalming technique, oral surgery and implantological procedures could be performed under realistic conditions similar to the living body. Due to the conservation procedure, preparations could be carried out without any time limit, always maintaining the same high quality of the tissue. The maxillary sinus membrane, mucosa, bone, and nerves could be exposed and allowed dissecting, drilling, and suturing even after weeks like fresh specimens. CONCLUSION: The Thiel embalming method is a unique technique which is ideally suited to practice and teach oral surgery and implantology on human material.

Selenium bioaccumulation and speciation in Chironomus dilutus exposed to water-borne selenate, selenite, or seleno-DL-methionine.

The objective of the present study was to describe the uptake and elimination kinetics of selenium (Se) administered in the forms of selenate, selenite, and selenomethionine (seleno-DL-methionine) in different life stages of the midge Chironomus dilutus, and to determine the relationship between Se bioavailability and Se speciation using X-ray absorption spectroscopy (XAS). Midge larvae exposed to 4.3 µg/L as dissolved selenate for 10 d of had negligible accumulation of Se (indistinguishable from control organisms). However, larvae rapidly accumulated Se over 10 d of exposure to 3.8 and 1.8 µg/L selenite and seleno-DL-methionine (Se-met), respectively. Most Se accumulated by larvae exposed to selenite or Se-met was retained after 10 d of elimination in clean water. When additional midge larvae were exposed to Se until emergence, Se accumulated during the larval stage was largely retained in the adults. Although a strong correlation was found between the adult whole-body Se concentration and the Se concentration in the exuvia after emergence, only a minor loss of Se occurred in the shed exuvia compared with larvae and adult whole-body concentrations. X-ray absorption spectroscopy analysis showed that organic selenides and diselenides, modeled as Se-met and selenocystine, respectively, were the dominant forms of Se in both the larval and adult insect stages. The proportion and concentration of organic selenides (selenomethionine) increased in larvae and adults exposed to Se-met and selenite compared with larvae exposed to selenate, whereas the concentration of diselenides (selenocystine) remained relatively constant for all treatments.

Evaluating the trophic transfer of selenium in aquatic ecosystems using caged fish, X-ray absorption spectroscopy and stable isotope analysis.

This research evaluated the dominant exposure pathways with regard to the bioaccumulation and trophic transfer of selenium (Se) in caged small-bodied fish inhabiting the receiving waters of a uranium-processing mill in northern Saskatchewan, Canada. A 21-day cage study was conducted using wild naïve lake chub (Couesius plumbeus) collected from a reference lake and caged in a reference and an exposure lake downstream of the mill discharge. Caged fish were fed commercially produced Chironomus spp. diets of 1.5 (basal - commercial food) and 5.5 (lab reared in Se-spiked water) µgSe/g (dry weight) at a feeding ration of 10 percent percent body weight/day. Lake chub fed the Se-spiked diet and caged in the reference lake showed increased whole-body Se concentrations compared to chub fed the basal diet after 21 days. Lake chub caged in the exposure lake from both the elevated Se and basal diet groups had significantly greater whole-body Se concentrations compared to the reference lake, and were not significantly different from each other. The use of stable carbon (C), nitrogen (N), and sulphur (S) isotope analyses indicated that alternate benthic food sources native to the exposure lake were likely consumed in conjunction with the controlled diets. Stable isotope analysis of both wild and caged lake chub indicated that the N and S isotopic signatures decreased with increasing Se exposure, which was reflective of the differences in isotopic signatures of the food sources. Dose-dependent substitution of Se for S in methionine as a consequence of dietary Se exposure was illustrated by a decreasing whole-body S isotope signature and an increasing proportion of selenomethionine-like compounds (as measured by synchrotron-based X-ray absorption spectroscopy) with increasing Se exposure. Speciation results from caged lake chub indicated that Se substituted for S in methionine was the dominant Se species found in caged lake chub exposed to dietary sources of Se.