The microbial ferrous wheel in a neutral pH groundwater seep

Evidence for microbial Fe redox cycling was documented in a circumneutral pH ground-water seep near Bloomington, Indiana. Geochemical and microbiological analyses were conducted at two sites, a semi-consolidated microbial mat and a floating puffball structure. In situ voltammetric microelectrode measurements revealed steep opposing gradients of o2 and Fe(I I) at both sites, similar to other groundwater seep and sedimentary environments known to support microbial Fe redox cycling. The puffball structure showed an abrupt increase in dissolved Fed I) just at its surface (~5cm depth), suggesting an internal Fe(I I) source coupled to active Fed 1I) reduction. Most probable number enumerations detected microaerophilic Fe(II)-oxidizing bacteria (FeoB) and dissimilatory Fe(III)-reducing bacteria (FeRB) at densities of 102 to 105 cells ml_~1 in samples from both sites. In vitro Fed 1I) reduction experiments revealed the potential for immediate reduction (no lag period) of native Fe(III) oxides. Conventional full-length 16S rRNA gene clone libraries were compared with high throughput barcode sequencing of theV1, V4, orV6 variable regions of 16S rRNA genes in order to evaluate the extent to which new sequencing approaches could provide enhanced insight into the composition of Fe redox cycling microbial community structure. The composition of the clone libraries suggested a lithotroph-dominated microbial community centered around taxa related to known FeoB (e.g., Gallionella, Sideroxydans, Aquabacterium). Sequences related to recognized FeRB (e.g., Rhodoferax, Aeromonas, Geobacter, Desulfovibrio) were also well-represented. overall, sequences related to known FeoB and FeRB accounted for 88 and 59% of total clone sequences in the mat and puffball libraries, respectively. Taxa identified in the barcode libraries showed partial overlap with the clone libraries, but were not always consistent across different variable regions and sequencing platforms. However, the barcode libraries provided confirmation of key clone library results (e.g., the predominance of Betaproteobacteria) and an expanded view of lithotrophic microbial community composition

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Unexplained orofacial pain - is an early diagnosis possible?

Aim: to identify distinct characteristics of unexplained orofacial pain that could be used by dental practitioners in making an early diagnosis.Methods: subjects reporting orofacial pain in a postal questionnaire-based cross-sectional survey were invited for clinical examination. The interviewer was blinded to the questionnaire responses of the subjects. A diagnosis was made following the examination and subjects were assigned into two groups: unexplained pain and dental pain. The questionnaire responses of subjects who had consulted a healthcare professional within these two groups were then compared with particular attention to demographics, orofacial pain characteristics, consultation behaviour and relationship with other unexplained syndromes.Results: subjects who had consulted for their pain and were assigned to the unexplained orofacial pain group were significantly (p <0.05) more likely to report the following characteristics: pain descriptors (nagging, aching, tingling), pain pattern (worse with stress), site (poorly localised), duration (persistent/chronic), high disability, multiple consultations and co-morbidities (teeth grinding, reporting of other unexplained syndromes).Conclusion: this study has shown that unexplained orofacial pain has distinct characteristics that differentiate it from other common dental conditions. This provides a good evidence base which can reduce uncertainty among dental practitioners, allowing them to make an early diagnosis

Labour Standards in the Generalized Systems of Preferences of the European Union and the United States

This article introduces an analytical framework for the study of labour standards in trade and compares and contrasts the approaches of the United States and the European Union in introducing a social clause in their Generalized Systems of Preferences. It explores the distinctive characteristics of the two approaches, assesses their industrial relations outcomes and proposes a set of policy guidelines