Dissipation of acetochlor and its distribution in surface and sub-surface soil fractions during laboratory incubations

Pesticides in soil are subject to a number of processes that result in transformation and biodegradation, sorption to and desorption from soil components, and diffusion and leaching. Pesticides leaching through a soil profile will be exposed to changing environmental conditions as different horizons with distinct physical, chemical and biological properties are encountered. The many ways in which soil properties influence pesticide retention and degradation need to be addressed to allow accurate predictions of environmental fate and the potential for groundwater pollution. Degradation and sorption processes were investigated in a long-term (100 days) study of the chloroacetanilide herbicide, acetochlor. Soil cores were collected from a clay soil profile and samples taken from 0-30cm (surface), 1.0-1.3m (mid) and 2.7-3.0m (deep) and treated with acetochlor (2.5, 1.25, 0.67 mu g acetochlor g(-1) dry wt soil, respectively). In sterile and non-sterile conditions, acetochlor concentration in the aqueous phase declined rapidly from the surface and subsoil layers, predominantly through nonextractable residue (NER) formation on soil surfaces, but also through biodegradation and biotic transformation. Abiotic transformation was also evident in the sterile soils. Several metabolites were produced, including acetochlor-ethane sulphonic acid and acetochlor-oxanilic acid. Transformation was principally microbial in origin, as shown by the differences between non-sterile and sterile soils. NER formation increased rapidly over the first 21 days in all soils and was mainly associated with the macroaggregate (> 2000 mu m diameter) size fractions. It is likely that acetochlor is incorporated into the macroaggregates through oxidative coupling, as humification of particulate organic matter progresses. The dissipation (ie total loss of acetochlor) half-life values were 9.3 (surface), 12.3 (mid) and 12.6 days (deep) in the non-sterile soils, compared with 20.9 [surface], 23.5 [mid], and 24 days [deep] in the sterile soils, demonstrating the importance of microbially driven processes in the rapid dissipation of acetochlor in soil.

The need for continued monitoring of antibiotic resistance patterns in clinical isolates of Staphylococcus aureus from London and Malta

Antibiotic resistance is an increasing problem in isolates of Staphylococcus aureus (S. aureus) worldwide. In 2001 The National Health Service in the UK introduced a mandatory bacteraemia surveillance scheme for the reporting of S. aureus and methicillin-resistant S. aureus (MRSA). This surveillance initiative reports on the percentage of isolates that are methicillin resistant. However, resistance to other antibiotics is not currently reported and therefore the scale of emerging resistance is currently unclear in the UK. In this study, multiple antibiotic resistance (MAR) profiles against fourteen antimicrobial drugs were investigated for 705 isolates of S. aureus collected from two European study sites in the UK (London) and Malta.

Molecular characterization of Cladium peat from the Florida Everglades: biomarker associations with humic fractions

The accumulation and preservation of peat soils in Everglades freshwater marshes and mangrove swamps is an essential process in the ecological functioning of these ecosystems. Human intervention and climate change have modified nutrient dynamics and hydroperiod in the Everglades and peat loss due to such anthropogenic activities is evident. However, not much is known on the molecular level regarding the biogeochemical characteristics, which allow peat to be preserved in the Everglades. Lipid biomarkers trapped within or bound to humic-type structures can provide important geochemical information regarding the origin and microbial transformation of OM in peat. Four lipid fractions obtained from a Cladium peat, namely the freely extractable fraction and those associated with humin, humic acid, and fulvic acid fractions, showed clear differences in their molecular distribution suggesting different OM sources and structural and diagenetic states of the source material. Both, higher plant derived and microbial lipids were found in association with these humic-type substances. Most biomarker distributions suggest an increment in the microbial/terrestrial lipid ratio from the free to humin to humic to fulvic fractions. Microbial reworking of lipids, and the incorporation of microbial biomarkers into the humic-type fractions was evident, as well as the preservation of diagenetic byproducts. The lipid distribution associated with the fulvic acids suggests a high degree of microbial reworking for this fraction. Evidence for this 3D structure was obtained through the presence of the relatively high abundance of α,ω-dicarboxylic acids and phenolic and benzenecarboxylic compounds. The increment in structural complexity of the phenolic and benzencarboxylic compounds in combination with the reduction in the carbon chain length of the dicarboxylic acids from the free to fulvic fraction suggests the latter to be structurally the most stable, compacted and diagenetically altered substrate. This analytical approach can now be applied to peat samples from other areas within the Everglades ecosystem, affected differently by human intervention with the aim to assess changes in organic matter preservation.

What Teaching Strategies Can I Employ to Improve Student Achievement in the Addition of Fractions with Different Denominators?

The purpose of this action research was to determine what instructional strategies could be used to improve student achievement in fraction addition. An eighth grade intensive math class practiced multiplication facts and hands-on applications of fractions concepts for 2 months. Pretests/posttests were used to measure improvement in computation and understanding.

E=MC3 Energy Equals Management's Continued Cost Concerns

E=MC³ Energy Equals Management's Continued Cost Concern, is an essay written by Fritz G. Hagenmeyer, Associate Professor, School of Hospitality Management at Florida International University. In the writing, Hagenmeyer initially tenders: “Energy problems in the hospitality industry can be contained or reduced, yielding elevated profits as a result of applied, quality management principles. The concepts, processes and procedures presented in this article are intended to aid present and future managers to become more effective with a sharpened focus on profitability.” This article is an overview of energy efficiency and the management of such. In an expanding energy consumption market with its escalating costs, energy management has become an ever increasing concern and component of responsible hospitality management, Hagenmeyer will have you know. “In endeavoring to "manage" on a day-to-day basis a functioning hospitality building's energy system, the person in charge must take on the role of Justice with her scales, attempting to balance the often varying comfort needs of guests and occupants with the invariable rising costs of energy utilized to generate and maintain such comfort conditions, since comfort is seen as an integral part of the "service," "product," or "price/value” perception of patrons,” says Hagenmeyer. In contrast to what was thought in the mid point of this century - that energy would be abundant and cheap - the reality has set-in that this is not the case; not by a long shot. The author wants you to be aware that energy costs in buildings are a force to be reckoned with; a major expense to be sure. “Since 1973, "energy-conscious design" has begun to become part of the repertoire of architects, design engineers, and construction companies,” Hagenmeyer states. “For instance, whereas office buildings of the early 1970s might have used 400,000 British Thermal Units (BTUs) per square foot year, new buildings are going up that use 55,000 to 65,000 BTUs per square foot year,” Hagenmeyer, like an incandescent bulb, illuminates you. Hagenmeyer references Robert E. Aulbach’s article - Energy Management – when informing you that the hospitality manager should not become complacent in addressing the energy cost issue, but should and must maintain a diligent focus on the problem. Hagenmeyer also makes reference to the Middle East War and to OPEC, and their influence on energy prices. In closing, Hagenmeyer suggests an - Energy Management Action Plan – which he outlines for you.

Analysis of Students’ Misconceptions and Error Patterns in Mathematics: The Case of Fractions

This study analyzed three fifth grade students’ misconceptions and error patterns when working with equivalence, addition and subtraction of fractions. The findings revealed that students used both conceptual and procedural knowledge to solve the problems. They used pictures, gave examples, and made connections to other mathematical concepts and to daily life topics. Error patterns found include using addition and subtraction of numerators and denominators, and finding the greatest common factor.

Geochemical data and radiocarbon ages of organic matter fractions and bacteriohopanepolyol data of sediment core GeoB6518-1 from the Congo River basin

The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. While elevated ages in fluvially-transported organic matter are usually explained by erosion of soils and sediments, it is commonly assumed that mainly young organic material is discharged from flat tropical watersheds due to their extensive plant cover and high carbon turnover. Here we present compound-specific radiocarbon data of terrigenous organic fractions from a sedimentary archive offshore the Congo River in conjunction with molecular markers for methane-producing land cover reflecting wetland extent in the watershed. We find that the Congo River has been discharging aged organic matter for several thousand years with increasing ages from the mid- to the Late Holocene. This suggests that aged organic matter in modern samples is concealed by radiocarbon from nuclear weapons testing. By comparison to indicators for past rainfall changes we detect a systematic control of organic matter sequestration and release by continental hydrology mediating temporary carbon storage in wetlands. As aridification also leads to exposure and rapid remineralization of large amounts of previously stored labile organic matter we infer that this process may cause a profound direct climate feedback currently underestimated in carbon cycle assessments.

(Table 5, page 626), Tin and main metal elements composition of ferromanganese concretions (acid-soluble fractions)

Concentrations of tin in sea water decreased from estuarine and shelf (0.02-0.04 µg/kg) to surface Atlantic waters (0.009 µg/kg). Mean contents (ppm) in other materials included: ultramafic rocks, 0.8; basalts, 1.7; silicic rocks, 2.5; red clays, 3.4; amphibolites, 1.2. Oceanic ferromanganese deposits contained from 0.2 to 5.8 ppm; tin and cobalt contents were correlated.

CAUTI prevention bundles: improving best practices within Western Health for continued success

Background: Persons in acute care settings who have indwelling urethral catheters are at higher risk of acquiring a urinary tract infection (UTI). Other complications related to prolonged indwelling urinary catheters include decreased mobility, damage to the meatus and/or urethra, increase use of antibiotics, increased length of stay, and pain. UTIs in acute care settings account for 30 to 40% of all health care associated infections (HAIs). Of these, 80% are catheter associated UTIs (CAUTIs). Purpose: To utilized the CDC (2009) bundle approach for CAUTI prevention and create a program which supports a multimodal method to improving urinary catheter use, maintenance, and removal, including a continuing competency program where role expansion is anticipated. Methods: A comprehensive review of the literature was conducted. Physicians were consulted through a power point presentation followed by a letter explaining the project, a questionnaire, and two selections of relevant literature. Nursing staff and allied health professionals from the target units of 3A and 3B medicine attended one of two lunch and learns. They were presented the project via a power point presentation and the same questionnaire as distributed to physicians. Results: Five e-learning modules, a revised policy, and clinical pathway have been developed to support staff with best practice knowledge transfer. Conclusion: Behaviour changes need to be approached with a framework, extensive consultation, and education. Sustainability of any practice change cannot occur without having completed the background work to ensure staff have access to tools to support the change.