Using phytoplankton diversity to determine wetland resilience, one year after a vegetable oil spill

A 250 t sunflower oil spill in the Con Joubert Bird Sanctuary Wetland, South Africa, was the largest global sunflower oil spill in a freshwater wetland to date. Since there was insufficient historical data for the Con Joubert Bird Sanctuary Wetland prior to the spill, variations in phytoplankton assemblages were used to indicate wetland resilience in relationship with water quality variables. From this study, it was evident that the phytoplankton biodiversity was a more reliable indicator of wetland resilience than vegetable oil concentrations measured in the water column. Vegetable oil concentrations measured in the water column varied both spatially and temporally and can possibly be linked to the passive movement of drifting oil in the water column caused by wind action and temperature changes. While we were unable to pinpoint the exact mechanisms behind the increase in phytoplankton biodiversity, the response was probably driven by the degradation of the oil by natural microbial consortiums in the wetland or a possible increase in phytoplankton grazers. Certain phytoplankton genera were found to be tolerant to the adverse effects of the oil spill. These genera include Oedogonium, Cyclotella, Spirogyra, a n d Planktothrix. In general, the univariate and multivariate statistical analysis showed a low diversity and richness at sites 1, 2 and 3 during the initial sampling surveys when compared to the remaining sites. However, the phytoplankton diversity and richness subsequently increased at all sampling sites from the second sampling survey, implying that there was a shift in phytoplankton biodiversity to a more stable state.National Research Foundation of South Africahttp://link.springer.com/journal/112702015-07-31hb201

An assessment of mercury contamination and the relationship between environmental variables and mercury concentrations in a seasonal wetland

A study was undertaken to assess the extent of mercury contamination in the water and sediment in a seasonal wetland, as well as to determine the relationship between environmental parameters and the distribution of the mercury contamination. Water and sediment samples were collected and analysed for methylmercury, inorganic mercury and other physical and chemical variables. One-way analysis of variance and homogeneity of variance were performed, and linear regression analysis was used to determine correlations between mercury and other environmental variables. The highest mercury concentrations were recorded at the sites located closest to the industrial complex. Methylmercury concentrations in the water and sediment were mostly higher during the low flow season, while inorganic mercury concentrations in the water and sediment were higher during the high flow and low flow seasons, respectively. Chromium, manganese, organic carbon and fine sediment particles were found to have significantly positive correlations with mercury concentrations in water and sediment. It was also found that the mercury concentrations decreased within a relatively short distance from the sites closer to the industrial complex to the sites further downstreamSouth African Synthetic Oil Limited (SASOL)http://link.springer.com/journal/11270#AboutSectionhttp://link.springer.com/article/10.1007%2Fs11270-013-1547-8DOI 10.1007/s11270-013-1547-

The development of a Wetland Classification and Risk Assessment Index (WCRAI) for non-wetland specialists for the management of natural freshwater wetland ecosystems

The Wetland Classification and Risk Assessment Index (WCRAI) is based on manifestations of ecological processes in natural wetland ecosystems. The index is hierarchical in structure and is designed to allow identification and rapid assessment at the broadest levels by non wetland experts in different disciplines to manage natural wetlands. From previous studies, landscape ecology has demonstrated the importance of considering landscape context in addition to local site attributes when explaining wetland ecological processes and ecological integrity. The pressures that land uses and activities exert on wetlands generate impacts that affect both the biotic and abiotic characteristics of the surface water column and the surrounding riparian zone. Therefore, human-altered land in a catchment and spatial patterns of surrounding wetlands provide a direct way to measure human impacts and can be correlated with indicators such as water chemistry and biotic variables. The objective of this study was to develop and test the WCRAI so that the index can be used to classify different types of wetlands and to assess their ecological condition (also known as “Eco-status”) under different ecological conditions. The results obtained from the WCRAI were indicative of the integrity of these wetlands when compared to the status of the abiotic and biotic variables measured at each sampling site. From an economical perspective, the WCRAI can play a crucial role in preventing unnecessary degradation of wetlands, hence reducing financial loss through management, restoration, or rehabilitation efforts. The methodology can be applied very easily (due to its simplistic nature) by industry stakeholders to continually monitor these wetlands.http://link.springer.com/journal/11270hb2014mn201

Traumatic thoracic and lumbar spinal fractures: Operative or nonoperative treatment - Comparison of two treatment strategies by means of surgeon equipoise

Abstract: Study Design. A center parallel cohort study with blinded inclusion based on clinical equipoise. Objective. To compare outcomes of nonoperative and operative treatment strategies in terms of quality of life and neurologic and functional status. Summary of Background Data. Despite a considerable body of literature, sound evidence regarding the optimal treatment for traumatic thoracic and lumbar spine fractures is lacking. Methods. Medical records of patients hospitalized for traumatic spinal fractures between 1991 and 2002 were identified in 2 trauma centers in the same country with established and different treatment strategies. Eligibility was retrospectively assessed for each case by a panel of orthopaedic surgeons who were representative of the 2 medical centers, and who were blinded to the treatment actually administered. Patients were included in the study when there was disagreement on the suggested treatment method. Thus, 2 comparable groups were identified undergoing nonoperative or operative treatment. Outcome assessment and comparison across groups focused on quality of life, residual pain, neurologic recovery, and employment in the middle-long-term follow-up. Results. Discordance in regards to choice of treatment was identified in 190 ( 95 treated nonoperative, 95 operative) of 636 potentially eligible patients. Patients were comparable regarding baseline characteristics, except for a somewhat higher proportion of males and neurologic impairment in the operative group. Seventeen percent of the nonoperative and 21% of the operative group developed complications and 3 patients displayed neurologic deterioration for which a treatment change was considered necessary. Follow-up was complete in 79%; mean follow-up time was 6.2 years with a minimum of 2 years. Pain scores, disability indexes, and general health outcome were comparable at follow-up. Compared with matched population norms, outcomes were poorer regardless of treatment method. Neurologic recovery was better in the operative group, but this difference did not reach statistical significance. Multivariate regression analyses revealed that female gender and neurologic impairment were independent predictors of poor functional outcome. Eighty-eight and 83% of the nonoperatively and operatively treated patients were employed at some point after a rehabilitation period. Conclusion. Overall outcome of nonoperative and operative treatment in middle-long-term follow up is comparable, although there seems to be a difference in neurologic recovery patterns. Studies on the cost-effectiveness of treatment options and the patterns of recovery within 2 years after injury would assist in guideline development and stimulate interest for future research.

Molecular profiles of response to neoadjuvant chemoradiotherapy in oesophageal cancers to develop personalized treatment strategies

Identification of molecular predictive markers of response to neoadjuvant chemoradiation could aid clinical decision-making in patients with localized oesophageal cancer. Therefore, we subjected pretreatment biopsies of 75 adenocarcinoma (OAC) and 16 squamous cell carcinoma (OSCC) patients to targeted next-generation DNA sequencing, as well as biopsies of 85 OAC and 20 OSCC patients to promoter methylation analysis of eight GI-specific genes, and subsequently searched for associations with histopathological response and disease-free (DFS) and overall survival (OS). Thereby, we found that in OAC, CSMD1 deletion (8%) and ETV4 amplification (5%) were associated with a favourable histopathological response, whereas SMURF1 amplification (5%) and SMARCA4 mutation (7%) were associated with an unfavourable histopathological response. KRAS (15%) and GATA4 (7%) amplification were associated with shorter OS. In OSCC, TP63 amplification (25%) and TFPI2 (10%) gene promoter methylation were associated with an unfavourable histopathological response and shorter DFS (TP63) and OS (TFPI2), whereas CDKN2A deletion (38%) was associated with prolonged OS. In conclusion, this study identified candidate genetic biomarkers associated with response to neoadjuvant chemoradiotherapy in patients with localized oesophageal cancer