568 research outputs found

    Current status and perspectives on anaerobic co-digestion and associated downstream processes

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    © The Royal Society of Chemistry. Anaerobic co-digestion (AcoD) has the potential to utilise spare digestion capacity at existing wastewater treatment plants to simultaneously enhance biogas production by digesting organic rich industrial waste and achieve sustainable organic waste management. While the benefits of AcoD regarding biogas production and waste management are well established, the introduction of a new organic waste (i.e. co-substrate) with different chemical composition compared to residential sewage sludge is expected to impact on not only the anaerobic digestion process itself but also downstream processing of biogas and digestate. This work critically evaluates the potential impact (both positive and negative) of co-digestion on key downstream processes in the context of AcoD of sewage sludge and organic waste. AcoD can potentially lead to significant changes in biogas quality, digestate dewaterability, biosolids odour and the nutrient balance within the overall wastewater treatment process. The literature reviewed here suggests that effective management of these impacts can enhance the economic and environmental benefits of AcoD. Potential techniques to manage the impact of AcoD on downstream processing include co-substrate selection to minimise sulphur content, co-substrate pretreatment to improve dewaterability, process optimisation to minimize downstream impacts, biological desulphurisation of biogas, and side stream nutrient recovery. These techniques have been investigated and in some cases successfully applied for conventional anaerobic digestion. Nevertheless, further research is needed to adapt them for AcoD. In particular, the issue of nutrient accumulation due to AcoD can be seen as an opportunity to utilise recently commercialised technologies (e.g. Phosnix and Ostara) and currently emerging processes (e.g. forward osmosis and electrodialysis) for phosphorus recovery from food waste and wastewater

    UK survey of occupational therapist’s and physiotherapist’s experiences and attitudes towards hip replacement precautions and equipment

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    Background: Total hip replacement (THR) is one of the most common orthopaedic procedures in the United Kingdom (UK). Historically, people following THR have been provided with hip precautions and equipment such as: raised toilet seats and furniture rises, in order to reduce the risks of dislocation post-operation. The purpose of this study was to determine current practices in the provision of these interventions in the UK for people following primary THR. Methods: A 27-question, self-administered online survey was developed and distributed to UK physiotherapists and occupational therapists involved in the management of people following primary THR (target respondents). The survey included questions regarding the current practices in the provision of equipment and hip precautions for THR patients, and physiotherapist’s and occupational therapist’s attitudes towards these practices. The survey was disseminated through print and web-based/social media channels. Results: 170 health professionals (87 physiotherapists and 83 occupational therapists), responded to the survey. Commonly prescribed equipment in respondent’s health trusts were raised toilet seats (95%), toilet frames and rails (88%), furniture raises (79%), helping hands/grabbers (77%), perching stools (75%) and long-handled shoe horns (75%). Hip precautions were routinely prescribed by 97% of respondents. Hip precautions were most frequently taught in a pre-operative group (52% of respondents). Similarly equipment was most frequently provided pre-operatively (61% respondents), and most commonly by occupational therapists (74% respondents). There was variability in the advice provided on the duration of hip precautions and equipment from up to six weeks post-operatively to life-time usage. Conclusions: Current practice on hip precautions and provision of equipment is not full representative of clinician’s perceptions of best care after THR. Future research is warranted to determine whether and to whom hip precautions and equipment should be prescribed post-THR as opposed to the current ‘blanket’ provision of equipment and movement restriction provided in UK practice

    Fair trade learning: ethical standards for community-engaged international volunteer tourism

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    The purpose of this paper is to articulate a set of ethical standards for international volunteer tourism. The standards are focused on promoting fair trade learning principles in the management and operation of volunteer programmes. Because of the unique social mission, research, and evaluation capacities of higher education, we propose first applying these principles specifically to international volunteer programmes operating at the university-community nexus. These standards have emerged through a collaborative, in-person and online process during the last two years with input by numerous concerned global citizens, international education practitioners and researchers, nongovernmental organization representatives, and community members. The document shared below represents current ‘best practice’ for maximizing the benefits and minimizing the negative impacts of volunteer tourism programmes for both host communities and volunteers

    Early replication in pulmonary B cells after infection with marek's disease herpesvirus by the respiratory route

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    Natural infection with Marek's disease virus occurs through the respiratory mucosa after chickens inhale dander shed from infected chickens. The early events in the lung following exposure to the feather and squamous epithelial cell debris containing the viral particles remain unclear. In order to elucidate the virological and immunological consequences of MDV infection for the respiratory tract, chickens were infected by intratracheal administration of infective dander. Differences between susceptible and resistant chickens were immediately apparent, with delayed viral replication and earlier onset of interferon (IFN)-γ production in the latter. CD4+ and CD8 + T cells surrounded infected cells in the lung. Although viral replication was evident in macrophages, pulmonary B cells were the main target cell type in susceptible chickens following intratracheal infection with MDV. In accordance, depletion of B cells curtailed viremia and substantially affected pathogenesis in susceptible chickens. Together the data described here demonstrate the role of pulmonary B cells as the primary and predominant target cells and their importance for MDV pathogenesis. © 2009, Mary Ann Liebert, Inc.

    Selection at a single locus leads to widespread expansion of toxoplasma gondii lineages that are virulent in mice

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    The determinants of virulence are rarely defined for eukaryotic parasites such as T. gondii, a widespread parasite of mammals that also infects humans, sometimes with serious consequences. Recent laboratory studies have established that variation in a single secreted protein, a serine/threonine kinase known as ROPO18, controls whether or not mice survive infection. Here, we establish the extent and nature of variation in ROP18among a collection of parasite strains from geographically diverse regions. Compared to other genes, ROP18 showed extremely high levels of diversification and changes in expression level, which correlated with severity of infection in mice. Comparison with an out-group demonstrated that changes in the upstream region that regulates expression of ROP18 led to an historical increase in the expression and exposed the protein to diversifying selective pressure. Surprisingly, only three atypically distinct protein variants exist despite marked genetic divergence elsewhere in the genome. These three forms of ROP18 are likely adaptations for different niches in nature, and they confer markedly different virulence to mice. The widespread distribution of a single mouse-virulent allele among geographically and genetically disparate parasites may have consequences for transmission and disease in other hosts, including humans

    Biopsy confirmation of metastatic sites in breast cancer patients:clinical impact and future perspectives

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    Determination of hormone receptor (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor 2 status in the primary tumor is clinically relevant to define breast cancer subtypes, clinical outcome,and the choice of therapy. Retrospective and prospective studies suggest that there is substantial discordance in receptor status between primary and recurrent breast cancer. Despite this evidence and current recommendations,the acquisition of tissue from metastatic deposits is not routine practice. As a consequence, therapeutic decisions for treatment in the metastatic setting are based on the features of the primary tumor. Reasons for this attitude include the invasiveness of the procedure and the unreliable outcome of biopsy, in particular for biopsies of lesions at complex visceral sites. Improvements in interventional radiology techniques mean that most metastatic sites are now accessible by minimally invasive methods, including surgery. In our opinion, since biopsies are diagnostic and changes in biological features between the primary and secondary tumors can occur, the routine biopsy of metastatic disease needs to be performed. In this review, we discuss the rationale for biopsy of suspected breast cancer metastases, review issues and caveats surrounding discordance of biomarker status between primary and metastatic tumors, and provide insights for deciding when to perform biopsy of suspected metastases and which one (s) to biopsy. We also speculate on the future translational implications for biopsy of suspected metastatic lesions in the context of clinical trials and the establishment of bio-banks of biopsy material taken from metastatic sites. We believe that such bio-banks will be important for exploring mechanisms of metastasis. In the future,advances in targeted therapy will depend on the availability of metastatic tissue

    Minimally Invasive Surgical Approaches and Traditional Total Hip Arthroplasty: A Meta-Analysis of Radiological and Complications Outcomes

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    BACKGROUND: Minimally invasive total hip arthroplasty (MITHA) remains considerably controversial. Limited visibility and prosthesis malposition increase the risk of post-surgical complications compared to those of the traditional method. METHODS: A meta-analysis was undertaken of all published databases up to May 2011. The studies were divided into four subgroups according to the surgical approach taken. The radiological outcomes and complications of minimally invasive surgery were compared to traditional total hip arthroplasty (TTHA) using risk ratio, mean difference, and standardized mean difference statistics. RESULTS: In five studies involving the posterolateral approach, no significant differences were found between the MITHA groups and the TTHA groups in the acetabular cup abduction angle (p = 0.41), acetabular anteversion (p = 0.96), and femoral prosthesis position (p = 0.83). However, the femoral offset was significantly increased (WMD = 3.00; 95% CI, 0.40-5.60; p = 0.02). Additionally, there were no significant differences among the complications in both the groups (dislocations, nerve injury, infection, deep vein thrombosis, proximal femoral fracture) and revision rate (p>0.05). In three studies involving the posterior approach, there were no significant differences in radiological outcomes or all other complications between MITHA or TTHA groups (p>0.05). Three studies involved anterolateral approach, while 2 studies used the lateral approach. However, the information from imaging and complications was not adequate for statistical analysis. CONCLUSIONS: Posterior MITHA seems to be a safe surgical procedure, without the increased risk of post-operative complication rates and component malposition rates. The posterolateral approach THA may lead to increased femoral offset. The current data are not enough to reach a positive conclusion that lateral and anterolateral approaches will result in increased risks of adverse effects and complications at the prosthesis site

    Structure and evolution of the gorilla and orangutan growth hormone loci

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    In primates, the unigenic growth hormone (GH) locus of prosimians, expressed primarily in the anterior pituitary, evolved by gene duplications, independently in New World Monkeys (NWM) and Old World Monkeys (OWMs)/apes, to give complex clusters of genes expressed in the pituitary and placenta. In human and chimpanzee, the GH locus comprises five genes, GH-N being expressed as pituitary GH, whereas GH-V (placental GH) and CSHs (chorionic somatomammotropins) are expressed (in human and probably chimpanzee) in the placenta; the CSHs comprise CSH-A, CSH-B and the aberrant CSH-L (possibly a pseudogene) in human, and CSH-A1, CSH-A2 and CSH-B in chimpanzee. Here the GH locus in two additional great apes, gorilla (Gorilla gorilla gorilla) and orangutan (Pongo abelii), is shown to contain six and four GH-like genes respectively. The gorilla locus possesses six potentially expressed genes, gGH-N, gGH-V and four gCSHs, whereas the orangutan locus has just three functional genes, oGH-N, oGH-V and oCSH-B, plus a pseudogene, oCSH-L. Analysis of regulatory sequences, including promoter, enhancer and P-elements, shows significant variation; in particular the proximal Pit-1 element of GH-V genes differs markedly from that of other genes in the cluster. Phylogenetic analysis shows that the initial gene duplication led to distinct GH-like and CSH-like genes, and that a second duplication provided separate GH-N and GH-V. However, evolution of the CSH-like genes remains unclear. Rapid adaptive evolution gave rise to the distinct CSHs, after the first duplication, and to GH-V after the second duplication. Analysis of transcriptomic databases derived from gorilla tissues establishes that the gGH-N, gGH-V and several gCSH genes are expressed, but the significance of the many CSH genes in gorilla remains unclear
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