The effect of oil sands process-affected water and model naphthenic acids on photosynthesis and growth in Emiliania huxleyi and Chlorella vulgaris

Naphthenic acids (NAs) are among the most toxic organic pollutants present in oil sands process waters (OSPW) and enter marine and freshwater environments through natural and anthropogenic sources. We investigated the effects of the acid extractable organic (AEO) fraction of OSPW and individual surrogate NAs, on maximum photosynthetic efficiency of photosystem II (PSII) (FV/FM) and cell growth in Emiliania huxleyi and Chlorella vulgaris as representative marine and freshwater phytoplankton. Whilst FV/FM in E. huxleyi and C. vulgaris was not inhibited by AEO, exposure to two surrogate NAs: (4'-n-butylphenyl)-4-butanoic acid (n-BPBA) and (4'-tert-butylphenyl)-4-butanoic acid (tert-BPBA), caused complete inhibition of FV/FM in E. huxleyi (≥10 mg L-1 n-BPBA; ≥50 mg L-1 tert-BPBA) but not in C. vulgaris. Growth rates and cell abundances in E. huxleyi were also reduced when exposed to ≥10 mg L-1 n- and tert-BPBA; however, higher concentrations of n- and tert-BPBA (100 mg L-1) were required to reduce cell growth in C. vulgaris. AEO at ≥10 mg L-1 stimulated E. huxleyi growth rate (p ≤ 0.002), yet had no apparent effect on C. vulgaris. In conclusion, E. huxleyi was generally more sensitive to NAs than C. vulgaris. This report provides a better understanding of the physiological responses of phytoplankton to NAs which will enable improved monitoring of NA pollution in aquatic ecosystems in the future

Biodegradation of alkyl branched aromatic alkanoic naphthenic acids by Pseudomonas putida KT2440

The majority of the world's crude oil reserves consist of highly biodegraded heavy and super heavy crude oils and oil sands that have not yet been fully exploited. These vast resources contain complex mixtures of carboxylic acids known as naphthenic acids (NAs). NAs cause major environmental and economic problems, as they are recalcitrant, corrosive and toxic. Although aromatic acids make up a small proportion of most NA mixtures, they have demonstrable toxicities to some organisms (e.g. some bacteria and algae) and ideally need to be removed or reduced by remediation. The present study analysed the ability of Pseudomonas putida KT2440 to degrade highly recalcitrant aromatic acids, as exemplified by the alkyl phenylalkanoic acid (4'-t-butylphenyl)-4-butanoic acid (t-BPBA) and the more degradable (4'-n-butylphenyl)-4-butanoic acid (n-BPBA). n-BPBA was completely metabolized after 14 days, with the production of a persistent metabolite identified as (4'-n-butylphenyl)ethanoic acid (BPEA) which resulted from removal of two carbon atoms from the carboxyl side chain (beta-oxidation) as observed previously with a mixed consortium. However, when n-BPBA concentration was increased two-fold, degradation decreased by 56% with a concomitant six-fold decrease in cell numbers, suggesting that at greater concentrations, n-BPBA may be toxic to P. putida KT2440. In contrast, P. putida KT2440 was unable to degrade the highly recalcitrant t-BPBA even after 49 days. These findings have implications for NA bioremediation in the environment. © 2011

Hidradenitis suppurativa associated with systemic lupus erythematosus: A case report

Rationale: Hidradenitis suppurativa (HS) is a chronic inflammatory condition characterized by recurrent swollen, deep, and painful abscesses. Several autoimmune conditions have been shown to be associated with HS including inflammatory bowel disease and spondyloarthropathies. Patient concerns: 40-year-old female with systemic lupus erythematous (SLE) presented with recurrent abscesses and nodules on her extremities. Diagnosis: Early considerations related the described dermatologic findings to the dermatologic manifestations of SLE, however findings from lesion biopsy were suggestive of HS. Interventions: Prednisone and antibiotic therapy with clindamycin were started. Subsequently upon discharge, the patient was also treated with rifampicin and azathioprine. Outcome: In this communication, we demonstrate a case of HS in a patient with SLE that significantly improved under antibiotic and immunosuppressant therapy. Lessons: HS can coexist in patients with SLE. Evidence pertinent to the etiology of HS and its association with other autoimmune conditions implies a possible denominator in the disease etiopathogenesis. Increased awareness of the co-occurrence of the two conditions calls for increased efforts to devise better treatment modalities

Electrical Components for Marine Renewable Energy Arrays: A Techno-Economic Review

This paper presents a review of the main electrical components that are expected to be present in marine renewable energy arrays. The review is put in context by appraising the current needs of the industry and identifying the key components required in both device and array-scale developments. For each component, electrical, mechanical and cost considerations are discussed; with quantitative data collected during the review made freely available for use by the community via an open access online repository. This data collection updates previous research and addresses gaps specific to emerging offshore technologies, such as marine and floating wind, and provides a comprehensive resource for the techno-economic assessment of offshore energy arrays

Instrumental delivery and ultrasound: a multicentre randomised controlled trial of ultrasound assessment of the fetal head position versus standard care as an approach to prevent morbidity at instrumental delivery

Objectives: To determine whether the use of ultrasound can reduce the incidence of incorrect diagnosis of the fetal head position at instrumental delivery and subsequent morbidity. Design: Two-arm, parallel, randomised trial, conducted from June 2011 to December 2012. Setting: Two maternity hospitals in the Republic of Ireland. Sample: 514 nulliparous women at term (≥37 weeks' gestation) with singleton cephalic pregnancies, aiming to deliver vaginally were recruited prior to induction of labour or in early labour. Methods: If instrumental delivery was required, women who had provided written consent were randomised to receive clinical assessment (standard care) or ultrasound scan and ultrasound assessment (ultrasound). Main outcome: Incorrect diagnosis of the fetal head position. Results: The incidence of incorrect diagnosis was significantly lower in the ultrasound group than the standard care group (4/257, 1.6% versus 52/257, 20.2%, odds ratio 0.06, 95% confidence interval (CI) 0.02 to 0.19, p value <0.001). The decision to delivery interval was similar in both groups (ultrasound mean 13.8 minutes, SD 8.7, versus standard care mean 14.6 minutes, SD 10.1, p value 0.35). The incidence of maternal and neonatal complications,4 failed instrumental delivery and caesarean section was not significantly different between the two groups. Conclusions: An ultrasound assessment prior to instrumental delivery reduced the incidence of incorrect diagnosis of the fetal head position without delaying delivery but did not prevent morbidity. A more integrated clinical skills-based approach is likely to be required to prevent adverse outcomes at instrumental delivery

The role of tenascin-C in tissue injury and tumorigenesis

The extracellular matrix molecule tenascin-C is highly expressed during embryonic development, tissue repair and in pathological situations such as chronic inflammation and cancer. Tenascin-C interacts with several other extracellular matrix molecules and cell-surface receptors, thus affecting tissue architecture, tissue resilience and cell responses. Tenascin-C modulates cell migration, proliferation and cellular signaling through induction of pro-inflammatory cytokines and oncogenic signaling molecules amongst other mechanisms. Given the causal role of inflammation in cancer progression, common mechanisms might be controlled by tenascin-C during both events. Drugs targeting the expression or function of tenascin-C or the tenascin-C protein itself are currently being developed and some drugs have already reached advanced clinical trials. This generates hope that increased knowledge about tenascin-C will further improve management of diseases with high tenascin-C expression such as chronic inflammation, heart failure, artheriosclerosis and cancer

Microbial biodegradation of aromatic alkanoic naphthenic acids is affected by the degree of alkyl side chain branching

Naphthenic acids (NAs) occur naturally in oil sands and enter the environment through natural and anthropogenic processes. NAs comprise toxic carboxylic acids that are difficult to degrade. Information on NA biodegradation mechanisms is limited, and there are no studies on alkyl branched aromatic alkanoic acid biodegradation, despite their contribution to NA toxicity and recalcitrance. Increased alkyl side chain branching has been proposed to explain NA recalcitrance. Using soil enrichments, we examined the biodegradation of four aromatic alkanoic acid isomers that differed in alkyl side chain branching: (4′-n-butylphenyl)-4-butanoic acid (n-BPBA, least branched); (4′-iso-butylphenyl)-4-butanoic acid (iso-BPBA); (4′-sec-butylphenyl)-4-butanoic acid (sec-BPBA) and (4′-tert-butylphenyl)-4-butanoic acid (tert-BPBA, most branched). n-BPBA was completely metabolized within 49 days. Mass spectral analysis confirmed that the more branched isomers iso-, sec- and tert-BPBA were transformed to their butylphenylethanoic acid (BPEA) counterparts at 14 days. The BPEA metabolites were generally less toxic than BPBAs as determined by Microtox assay. n-BPEA was further transformed to a diacid, showing that carboxylation of the alkyl side chain occurred. In each case, biodegradation of the carboxyl side chain proceeded through beta-oxidation, which depended on the degree of alkyl side chain branching, and a BPBA degradation pathway is proposed. Comparison of 16S rRNA gene sequences at days 0 and 49 showed an increase and high abundance at day 49 of Pseudomonas (sec-BPBA), Burkholderia (n-, iso-, tert-BPBA) and Sphingomonas (n-, sec-BPBA)

Oligomeric structure of the Bacillus subtilis cell division protein DivIVA determined by transmission electron microscopy

DivIVA from Bacillus subtilis is a bifunctional protein with distinct roles in cell division and sporulation. During vegetative growth, DivIVA regulates the activity of the MinCD complex, thus helping to direct cell division to the correct mid-cell position. DivIVA fulfils a quite different role during sporulation in B. subtilis when it directs the oriC region of the chromosome to the cell pole before asymmetric cell division. DivIVA is a 19.5 kDa protein with a large part of its structure predicted to form a tropomyosin-like alpha-helical coiled-coil. Here, we present a model for the quaternary structure of DivIVA, based on cryonegative stain transmission electron microscopy images. The purified protein appears as an elongated particle with lateral expansions at both ends producing a form that resembles a 'doggy-bone'. The particle mass estimated from these images agrees with the value of 145 kDa measured by analytical ultracentrifugation suggesting 6- to 8-mers. These DivIVA oligomers serve as building blocks in the formation of higher order assemblies giving rise to strings, wires and, finally, two-dimensional lattices in a time-dependent manner