A Validation Study of a Rapid Field-Based Rating System for Discriminating Among Flow Permanence Classes of Headwater Streams in South Carolina

Rapid field-based protocols for classifying flow permanence of headwater streams are needed to inform timely regulatory decisions. Such an existing method was developed for and has been used in North Carolina since 1998. The method uses ordinal scoring of 26 geomorphology, hydrology, and biology attributes of streams. The attribute scores are summed and compared to threshold scores to assign a flow permanence class. Our study objective was to evaluate the method’s ability to classify the flow permanence of forested stream reaches from Piedmont and Southeastern Plains ecoregions in South Carolina. Ephemeral reaches scored significantly lower than intermittent and perennial reaches, but scores from intermittent and perennial reaches did not differ. Scores collected in the dry and wet seasons were strongly correlated, indicating that the method was seasonally stable. Scores had positive nonlinear relationships with the maximum recorded wet duration and the proportion of the record that reaches were wet, but were not related to drying frequency. Scores of the presence of baseflow in the dry season were more important in flow permanence classification than those from the wet season. Other important attributes and parameters in discriminating flow classes were macrobenthos, rooted upland plants, bankfull width, drainage area, and ecoregion. Although the North Carolina method did not consistently differentiate intermittent from perennial reaches, the indicator-based approach is a strong foundation from which to build a protocol for South Carolina. Adding measures like bankfull width and drainage area, weighting by ecoregion, or shifting thresholds may be warranted modifications for South Carolina.     

Development of an Ecologic Marine Classification in the New Zealand Region

We describe here the development of an ecosystem classification designed to underpin the conservation management of marine environments in the New Zealand region. The classification was defined using multivariate classification using explicit environmental layers chosen for their role in driving spatial variation in biologic patterns: depth, mean annual solar radiation, winter sea surface temperature, annual amplitude of sea surface temperature, spatial gradient of sea surface temperature, summer sea surface temperature anomaly, mean wave-induced orbital velocity at the seabed, tidal current velocity, and seabed slope. All variables were derived as gridded data layers at a resolution of 1 km. Variables were selected by assessing their degree of correlation with biologic distributions using separate data sets for demersal fish, benthic invertebrates, and chlorophyll-a. We developed a tuning procedure based on the Mantel test to refine the classification's discrimination of variation in biologic character. This was achieved by increasing the weighting of variables that play a dominant role and/or by transforming variables where this increased their correlation with biologic differences. We assessed the classification's ability to discriminate biologic variation using analysis of similarity. This indicated that the discrimination of biologic differences generally increased with increasing classification detail and varied for different taxonomic groups. Advantages of using a numeric approach compared with geographic-based (regionalisation) approaches include better representation of spatial patterns of variation and the ability to apply the classification at widely varying levels of detail. We expect this classification to provide a useful framework for a range of management applications, including providing frameworks for environmental monitoring and reporting and identifying representative areas for conservation.     

The leaching characteristics of selenium from coal fly ashes

The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results for different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbituminous coal ashes at any pH. However, Se(IV) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbituminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO3* and SeO3 2* were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.     

Shortened fetal long bones: a possible in utero manifestation of placental function

Shortened fetal long bones (SFLB) are usually indicative of a skeletal dysplasia. Our aim in this observational retrospective study was to describe a new association between SFLB, small for gestational age (SGA) fetuses and placental abnormalities, and to suggest an aetiologic explanation. During the last decade we have evaluated nine cases in which SFLB (more than 2SD below the mean) was associated with SGA, abnormal maternal serum placental hormones and abnormal placental sonography. Six cases had significantly increased second trimester maternal serum βhCG and four developed toxaemia of pregnancy or had chronic hypertension. On histology, mature placentas with vascular abnormalities, including chorangiosis, large infarcts and slightly increased syncytial knots were noted. The combination of SFLB, SGA fetuses and placental abnormalities (sonographic, as well as histological) suggested a possible common pathway in the aetiology of this association. Copyright © 2002 John Wiley & Sons, Ltd.     

Disseminating near-real-time hazards information and flood maps in the Philippines through Web-GIS

The Philippines being a locus of tropical cyclones, tsunamis, earthquakes and volcanic eruptions, is a hotbed of disasters. These natural hazards inflict loss of lives and costly damage to property. Situated in a region where climate and geophysical tempest is common, the Philippines will inevitably suffer from calamities similar to those experienced recently. With continued development and population growth in hazard prone areas, it is expected that damage to infrastructure and human losses would persist and even rise unless appropriate measures are immediately implemented by government. In 2012, the Philippines launched a responsive program for disaster prevention and mitigation called the Nationwide Operational Assessment of Hazards (Project NOAH), specifically for government warning agencies to be able to provide a 6 hr lead-time warning to vulnerable communities against impending floods and to use advanced technology to enhance current geo-hazard vulnerability maps. To disseminate such critical information to as wide an audience as possible, a Web-GIS using mashups of freely available source codes and application program interface (APIs) was developed and can be found in the URLs http:// noah.dost.gov.ph and http://noah.up.edu.ph/. This Web-GIS tool is now heavily used by local government units in the Philippines in their disaster prevention and mitigation efforts and can be replicated in countries that have a proactive approach to address the impacts of natural hazards but lack sufficient funds.     

Implementing the evidence for preventing falls among community-dwelling older people: a systematic review

Problem and objective

The translation of the evidence-base for preventing falls among community-dwelling older people into practice has been limited. This study systematically reviewed and synthesised the effectiveness of methods to implement falls prevention programmes with this population.

Methods

Articles published between 1980 and May 2010 that evaluated the effects of an implementation strategy. No design restrictions were imposed. A narrative synthesis was undertaken.

Results

15 studies were identified. Interventions that involved the active training of healthcare professionals improved implementation. The evidence around changing the way people who fall are managed within primary care practices, and, layperson, peer or community delivered models was mixed.

Impact on industry

Translating the evidence-base into practice involves changing the attitudes and behaviours of older people, healthcare professionals and organisations. However, there is a need for further evaluation on how this can be best achieved.     

Diphenylmethane diisocyanate self-polymerization: Thermal hazard evaluation and proof of runaway reaction in gram scale

Thermal analysis by differential scanning calorimetry and thermogravimetric/differential thermal analysis mass spectrometry, adiabatic calorimetry, a gram-scale heating test, and infrared spectroscopy were performed to evaluate the thermal hazards of diphenylmethane diisocyanate (MDI) and prove the occurrence of a runaway reaction. The self-polymerization of MDI was found to occur at about 340 °C under rapid heating conditions. Carbon dioxide was eliminated and heat was generated to allow polymerization. Under adiabatic and closed conditions, the runaway reaction of MDI can begin at least from 220 °C. Besides it is highly probable that the runaway reaction of MDI can begin from a lower temperature in an actual process scale. More heat was generated than in the previous case and the pressure rose rapidly. A closed 2-mm-thick glass vessel exploded because of the runaway reaction of MDI even if the temperature was lower than 300 °C. Therefore, MDI could cause fatal runaway reactions below 300 °C, where MDI had been assumed to self-polymerize by eliminating carbon dioxide previously.     

Coupled cycles of dissolved oxygen and nitrous oxide in rivers along a trophic gradient in southern Ontario, Canada

Diel (24-h) cycling of dissolved O2 (DO) in rivers is well documented, but evidence for coupled diel changes in DO and nitrogen cycling has only been demonstrated in hypereutrophic systems where DO approaches zero at night. Here, we show diel changes in N2O and DO concentration at several sites across a trophic gradient. Nitrous oxide concentration increased at night at all but one site in spring and summer, even when gas exchange was rapid and minimum water column DO was well above hypoxic conditions. Diel N2O curves were not mirror images of DO curves and were not symmetrical about the mean. Although inter- and intrasite variation was high, N2O peaked around the time of lowest DO at most of the sites. These results suggest that N2O must be measured several times per diel period to characterize curve shape and timing. Nitrous oxide concentration was not significantly correlated with NO3- concentration, contrary to studies in agricultural streams and to the current United Nations Intergovernmental Panel for Climate Change protocols for N2O emission estimation. The strong negative correlation between N2O concentration and daily minimum DO concentration suggested that N2O production was limited by DO. This is consistent with N2O produced by nitrite reduction. The ubiquity of diel N2O cycling suggests that most DO and N2O sampling strategies used in rivers are insufficient to capture natural variability. Ecosystem-level effects of microbial processes, such as denitrification, are sensitive to small changes in redox conditions in the water column even in low-nutrient oxic rivers, suggesting diel cycling of redox-sensitive compounds may exist in many aquatic systems.