The Rockefeller Institute Review 1964, vol. 2, no. 4

The Review is issued bimonthly. The cover photograph by Richard Carter: the north end of Abby Hall.https://digitalcommons.rockefeller.edu/rockefeller_institute_review/1007/thumbnail.jp

Maintaining Curriculum Consistency of Technical and Vocational Educational Programs through Teacher Design Teams

Maintaining the quality and relevance of Technical Vocational Education and Training (TVET) curricula is a great challenge for TVET institutions in developing countries. One major challenge lies in the lack of curriculum design expertise of TVET academics. The purpose of this multiplecase study is to explore the potential of professionally supported Teacher Design Teams (TDTs), a group of department teachers working collaboratively on a curriculum (re)design task, as an institution-based strategy for improving the relevance of TVET programs to the needs of the concerned stakeholders, namely industry. The study describes how four TDTs from different TVET college departments redesigned their programs systematically and relationally to improve their internal and external consistency. The findings indicated that although the teams found the re-design task a challenge, they felt positive about the TDT experience and its outcomes. The teams also perceived the consistency of their programs to have improved. The criticality of the support offered to the teams and the variety of the teams’ design work were salient themes captured during the design process. It is concluded that professionally supported TDTs can be an efficient strategy for maintaining the consistency of the TVET curriculu

Persistence of perfluoroalkylated substances in closed bottle tests with municipal sewage sludge

Background, aim, and scope Perfluoroalkylated substances (PFAS) are chemicals with completely fluorinated alkyl chains. The specific properties of the F-C bond give PFAS a high stability and make them very useful in a wide range of applications. PFAS also pose a potential risk to the environment and humans because they have been recently characterized as persistent, bioaccumulative, and toxic. The objective of this work is to study the bacterial degradation of PFAS under aerobic and anaerobic conditions in municipal sewage sludge as a contribution toward understanding their environmental fate and behavior. Materials and methods Bacterial communities from sewage sludge were exposed to a mixture of PFAS under aerobic or anaerobic conditions. Individual PFAS concentrations were determined in the experiment media at different exposure times using liquid chromatography-mass spectrometry analysis after extraction with solid-phase extraction. Results The PFAS analyses of samples of sludge showed repeatable replicate results, allowing a reliable quantification of the different groups of PFAS analyzed. No conclusive evidence for PFAS degradation was observed under the experimental conditions tested in this work. Reduction in concentrations, however, was observed for some PFAS in sludge under aerobic conditions. Discussion The largest concentration decrease occurred for the fluorotelomer alcohols (FTOHs), especially for the 8:2 FTOH, which have been described as biodegradable in the literature. However, this concentration decrease could be due to different causes: sorption to glass, septa, or matrix components, as well as bacterial activity. Therefore, it is not certain that biodegradation occurred. Conclusions PFAS are very recalcitrant chemicals, especially when fully fluorinated. Although some decreases in concentration have been observed for some PFAS, such as the FTOHs, there is no conclusive evidence for biodegradation. It can be concluded that the PFAS tested in these experiments are non-biodegradable under these experimental conditions. Recommendations and perspectives Since the presence of PFAS is ubiquitous in the environment and they can be toxic, more research is needed in this field to elucidate which PFAS are susceptible to biodegradation, the conditions required for biodegradation, and the possible routes followed. A possible inhibitory effect of PFAS on bacteria, the threshold concentrations, and conditions of inhibition should also be investigated

Strategies for optimal fertiliser management of vegetable crops in Europe

In Europe a number of procedures are used to assist growers and advisors to determine optimal N fertiliser recommendations. The implementation of European Union (EU) legislation is encouraging the adoption of fertiliser recommendation schemes. The most widely used schemes are those based on soil testing or on the use of indices that estimate the soil nitrogen supply. Soil testing approaches that are in use, particularly in NW Europe are the Nmin, KNS and N-Expert systems; the latter is operated as a computer-based decision support system (DSS). The comprehensive RB209 Fertiliser Manual of England and Wales uses soil N supply indices, but soil analysis can also be used. Nitrogen balance calculations are widely used throughout Europe and form part of the KNS and N-Expert systems, and a number of other DSSs. The N balance considers the various soil N sources and treats mineral N fertiliser as a supplemental N source. The EU-Rotate_N simulation model is a comprehensive and versatile tool, developed for diverse European conditions, that is useful for scenario analysis simulations to stakeholders. Various DSS have been developed in different European countries, with different levels of complexity. There are a number of different DSS that calculate N fertiliser recommendations for particular cropping systems; some DSS calculate the requirements for other nutrients, and some also do so for irrigation which is particularly useful where fertigation is used. Sap analysis has been shown to be sensitive to crop nutrient status, for N and some other nutrients; currently, there is renewed interest in sap analysis. Proximal optical sensors are a promising approach for N management

A novel sample preparation procedure for effect-directed analysis of micro-contaminants of emerging concern in surface waters

A novel sample preparation procedure relying on Solid Phase Extraction (SPE) combining different sorbent materials on a sequential-based cartridge was optimized and validated for the enrichment of 117 widely diverse contaminants of emerging concern (CECs) from surface waters (SW) and further combined chemical and biological analysis on subsequent extracts. A liquid chromatography coupled to high resolution tandem mass spectrometry LC-(HR)MS/MS protocol was optimized and validated for the quantitative analysis of organic CECs in SW extracts. A battery of in vitro CALUX bioassays for the assessment of endocrine, metabolic and genotoxic interference and oxidative stress were performed on the same SW extracts. Satisfactory recoveries ([70–130]%) and precision ( 0.99) over three orders of magnitude. Instrumental limits of detection and method limits of quantification were of [1–96] pg injected and [0.1–58] ng/L, respectively; while corresponding intra-day and inter-day precision did not exceed 11% and 20%. The developed procedure was successfully applied for the combined chemical and toxicological assessment of SW intended for drinking water supply. Levels of compounds varied from < 10 ng/L to < 500 ng/L. Endocrine (i.e. estrogenic and anti-androgenic) and metabolic interference responses were observed. Given the demonstrated reliability of the validated sample preparation method, the authors propose its integration in an effect-directed analysis procedure for a proper evaluation of SW quality and hazard assessment of CECs