Resuspension and settling of helminth eggs in water: Interactions with cohesive sediments

Helminth parasite eggs in low quality water represent main food safety and health hazards and are therefore important indicators used to determine whether such water can be used for irrigation. Through sedimentation helminth eggs accumulate in the sediment, however resuspension of deposited helminth eggs will lead to increased concentration of suspended eggs in the water. Our study aimed to determine the erodibility (erosion rate and erosion threshold) and settling velocity of Ascaris and Trichuris eggs as well as cohesive sediment at different time points after incorporation into the sediment. Cohesive sediment collected from a freshwater stream was used to prepare a sediment bed onto which helminth eggs were allowed to settle. The erodibility of both sediment and helminth eggs was found to decrease over time indicating that the eggs were incorporated into the surface material of the bed and that this material was stabilized through time. This interaction between eggs and bulk sediment was further manifested in an increased settling velocity of suspended eggs when sediment was present in the suspension as compared to a situation with settling in clean water. The incorporation into the sediment bed and the aggregation with sediment particles decrease the mobility of both helminth egg types. Our findings document that helminth eggs should not be viewed as single entities in water systems when modelling the distribution of eggs since both erodibility and settling velocity of eggs are determined by mobility of the sediment present in the water stream. Recalculation of the erosion threshold for helminth eggs and sediment showed that even at relatively low current velocities i.e. 0.07-0.12 m s⁻¹ newly deposited eggs will be mobile in open irrigation channels. These environmental factors affecting resuspension must be taken into account when developing models for sedimentation of helminth eggs in different water systems.     

Surface modification using self‐assembled layers of amphiphilic cyclodextrins

In this study six amphiphilic cyclodextrin derivatives were prepared by esterification and used to coat five industrial products made from polypropylene, polyethylene, polyvinyl chloride, or polyurethane using a new, patented coating technology. This simple approach, which consists merely of dipping the material to be coated into a suspension of a given cyclodextrin derivative in an ethanol/water solution, was used to functionalize support materials with a coat that is stable in aqueous solutions and which renders the coated materials hydrophilic. The functionalization proved to be controllable in terms of amount of cyclodextrin on the surface and can be implemented in existing production lines without investment in advanced production equipment. It is hypothesized that the cyclodextrins order themselves in structured layers forming channel‐like structures preserving the very large potential for uptake and release of active compounds that is known to cyclodextrins. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41047.     

Method for retrospective collection of work-related psychosocial risk factors for musculoskeletal disorders: Reliability and aggregation.

Information on psychosocial work conditions during a 24-year period for 484 participants was collected retrospectively. Analyses were made of the interrater reliability, stability, specificity, and aggregation of data. The main finding was that it is possible to collect reliable information about psychosocial work conditions retrospectively for a long period of years when using a time ruler in a structured interview when earlier conditions are compared with the present. Interrater agreement was satisfactory for the larger part of the studied retrospective psychosocial risk factors and excellent for some of them. For most of the studied risk factors, the risk of overreporting exposure was low. The aggregation of data resulted in 2 indexes: poor social relations at work and low influence over work conditions. In conclusion, an individual time ruler works satisfactorily as a method of collecting retrospective information about psychosocial risk factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting Air Permeability in Undisturbed, Subsurface Sandy Soils from Air-Filled Porosity

A model for predicting air permeability (ka) as function of air-filled porosity (ε) in undisturbed subsurface sandy soils, relevant for vapor extraction system design and operation, was developed using data from eight undisturbed soils (approximately 240 samples). The model requires only one measurement of corresponding values of ka and ε as input to estimate ka at any desired value of ε. The soils used represent both urban, agricultural and forest locations. The model is based on the fact that the relationships between log(ka) and log(ε) in sandy soils are approximately linear and on average pass through a common interception point, although with very different slopes. An expression for predicting ka at ?100?cm?H2O soil water potential (ka100) from ε at the same potential (ε100) for sandy soils was also developed. Using this expression together with the new ka(ε) predictive model enables prediction of the entire ka(ε) relation without any ka measurements using only a measurement of ε100. This approach results in only a slightly higher prediction uncertainty. The model was tested against an independent set of data from five undisturbed sandy soils (22 samples) and close agreement between measured and predicted air permeability values was found.     

Intention to respond to local wind turbines: the role of attitudes and visual perception

Wind power projects frequently face public opposition during the siting process. A deeper understanding of social factors has therefore been called for. Based on psychological theories, the present research was initiated in order to study the relative importance of individual aspects related to visual perception and attitudinal factors in public intention to oppose local wind turbines. In an empirical study, 80 people assessed the visual characteristics of wind turbines on site and rated their emotional state. They also completed a questionnaire covering attitudes towards the turbines, perception of significant others' opinions of local wind turbines, and perceived possibilities to oppose as well as intention to oppose local turbines. Moreover, socio‐demographics, factors related to the place of residence and general attitude towards wind power, were investigated. In a multiple regression analysis explaining 50% of the variance, it was found that intention to oppose was related to only a few perceptual and attitudinal factors, i.e. the perceived unity of the environment, the personal attitude towards the effects of wind turbines on landscape aesthetics and recreation, and the general attitude towards wind power. Of minor importance was the attitude towards the effects of wind turbines on people's daily quality of life. It seems important to involve the public in the discussion of how wind power installations can be integrated into the landscape without threatening the visual beauty and the recreational value of the natural and cultural environment. Moreover, social intervention is required to promote positive attitudes towards wind turbines. Copyright © 2007 John Wiley & Sons, Ltd.     

Cartilage Turnover Reflected by Metabolic Processing of Type II Collagen: A Novel Marker of Anabolic Function in Chondrocytes

The aim of this study was to enable measurement of cartilage formation by a novel biomarker of type II collagen formation. The competitive enzyme-linked immunosorbent assay (ELISA) Pro-C2 was developed and characterized for assessment of the beta splice variant of type II procollagen (PIIBNP). This is expected to originate primarily from remodeling of hyaline cartilage. A mouse monoclonal antibody (Mab) was raised in mouse, targeting specifically PIIBNP (QDVRQPG) and used in development of the assay. The specificity, sensitivity, 4-parameter fit and stability of the assay were tested. Levels of PIIBNP were quantified in human serum (0.6–2.2 nM), human amniotic fluid (163–188 nM) and sera from different animal species, e.g., fetal bovine serum (851–901 nM) with general good linearity (100% (SD 7.6) recovery) and good intra- and inter-assay variation (CV% < 10). Dose (0.1 to 100 ng/mL) and time (7, 14 and 21 days) dependent release of PIIBNP were evaluated in the conditioned medium from bovine cartilage explants (BEX) and human cartilage explants (HEX) upon stimulation with insulin-like growth factor (IGF-1), transforming growth factor (TGF)-β1 and fibroblastic growth factor-2 (FGF-2). TGF-β1 and IGF-1 in concentrations of 10–100 ng/mL significantly (p < 0.05) induced release of PIIBNP in BEX compared to conditions without treatment (WO). In HEX, IGF-1 100 ng/mL was able to induce a significant increase of PIIBNP after one week compared to WO. FGF-2 did not induce a PIIBNP release in our models. To our knowledge this is the first assay, which is able to specifically evaluate PIIBNP excretion. The Pro-C2 assay seems to provide a promising and novel marker of type II collagen formation.     

The impact of light and colour on psychological mood: a cross-cultural study of indoor work environments

The aim of the study was to determine whether indoor lighting and colour would have any systematic impact on the mood of people working indoors. Earlier studies have mostly focused either on light, colour or windows in laboratory settings. The present study was carried out in real work environments at different seasons and in countries with different latitudes. A total of 988 persons completed all parts of the study. In the countries situated far north of the equator there was a significant variation in psychological mood over the year that did not occur in the countries closer to the equator. When all four countries were considered together, it became evident that the light and colour of the workplace itself also had an influence on the mood of persons working there. The workers' mood was at its lowest when the lighting was experienced as much too dark. The mood then improved and reached its highest level when the lighting was experienced as just right, but when it became too bright the mood declined again. On the other hand, the illuminance as measured in objective terms, showed no significant impact on mood at any time of the year. The relationship between mood and the distance to the nearest window was bimodal. The results also indicate that the use of good colour design might contribute to a more positive mood. It is suggested that in future research light and colour should be studied as parts of the more complex system making up a healthy building.     

Preparation of stimuli-responsive nano-sized capsules based on cyclodextrin polymers with redox or light switching properties

We report the preparation and encapsulation properties of stimuli-responsive nanocapsules, self-assembled by the noncovalent interactions of cyclodextrinappended polymers (host) and complementary ferrocene or azobenzene carriers (guest). The encapsulation process was significantly accelerated by applying (electro) chemical or light stimulus, enabling the easier and faster diffusion of guest molecules through the polymer layers. The nanocapsules were characterized by dynamic light scattering, confocal microscopy, ESEM, AFM, UV–visible and fluorescence spectroscopy, and electrochemical techniques. The encapsulation and release properties of the nanocapsules were reversible and could be repeated several times, indicating that the prepared nanoassemblies are very stable.

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瑞典隆德理工学院校园公园

正隆德理工学院(Lund Institute of Technology,LTH)拥有一个朝向东侧的巨大缓坡绿地景观。这片土地曾经被用于耕作。自1961年成立以来,该大学便致力于在瑞典南部建设为一所涵盖建筑学在内的高等工科院校。如今,隆德理工学院已经为10 000名学生提供了高等教育。该学校的建筑师是兰卡斯特·安塞姆(Klas Anselm)。他在这块坡地上设计了十几座简单的红砖建筑,如今它们各自孤立地散布在斜