The influence of social support and active coping on depression among African Americans and Latinos with disabilities.

Examined relationships among depression, active coping, and social support in a sample of 109 African Americans and 57 Latinos with a variety of disabling conditions, including physical, chronic illness, neurological, sensory, emotional, substance abuse, and cognitive disabilities. Ss' ages ranged from 18 to over 61 yrs old. Measures included a short version of the Beck Depression Inventory, the Personal Resources Questionnaire and the condensed version of the Behavioral Attributes of Psychosocial Competence Scale. Findings indicate that active coping, satisfaction with social support, and type of disability were significant predictors of depression for African Americans, whereas active coping, perception of severity of disability, and social support were significant predictors of depression for Latinos. These findings underscore the importance of testing separate models for African Americans and Latinos. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Urinary 1-hydroxypyrene in children living in city and rural residences in Denmark

AIMS: The present study aims to assess the biological uptake in children of polycyclic aromatic hydrocarbons measured as 1-hydroxypyrene in urine from children living in city and rural residences. METHODS: 103 children living in Copenhagen and 101 children living in rural residences of Denmark collected urine samples Monday to Friday morning. Each day, the family filled in a printed diary that included questions about the time and activity patterns of the child. Multiple regression analyses were used to identify predictors of the excreted 1-hydroxypyrene level. RESULTS: During the week, the children excreted on average 0.07 [95% CI: 0.01-0.41] mumol urinary 1-hydroxypyrene per mol creatinine. Children living in urban residences excreted 0.02 [95% CI: 0.01-0.05] mumol more 1-hydroxypyrene than children living in rural residences. This was confirmed in the multiple regression analysis showing a 29% (95% CI: 2-64%) higher excretion among urban children than rural children. Moreover, the regression analysis showed that for each hour per day spent outside the children excreted 58% (1.58 [1.22-2.03]) more 1-hydroxypyrene in urine. CONCLUSION: The present study indicates that children living in urban residences are more exposed to PAH than children living in rural residences. Time spent outdoors increased the excretion of 1-hydroxypyrene, which was most evident among urban children. Higher concentrations of ambient air pollution in urban areas may explain this finding. No influence of environmental tobacco smoke, cooking habits, and heating facilities was detected.     

Intelligent speed adaptation as an assistive device for drivers with acquired brain injury: A single-case field experiment

Intelligent speed adaptation (ISA) was tested as an assistive device for drivers with an acquired brain injury (ABI). The study was part of the “Pay as You Speed” project (PAYS) and used the same equipment and technology as the main study (0030 and 0035). Two drivers with ABI were recruited as subjects and had ISA equipment installed in their private vehicle. Their speed was logged with ISA equipment for a total of 30 weeks of which 12 weeks were with an active ISA user interface (6 weeks = Baseline 1; 12 weeks = ISA period; 12 weeks = Baseline 2). The subjects participated in two semi-structured interviews concerning their strategies for driving with ABI and for driving with ISA. Furthermore, they gave consent to have data from their clinical journals and be a part of the study. The two subjects did not report any instances of being distracted or confused by ISA, and in general they described driving with ISA as relaxed. ISA reduced the percentage of the total distance that was driven with a speed above the speed limit (PDA), but the subjects relapsed to their previous PDA level in Baseline 2. This suggests that ISA is more suited as a permanent assistive device (i.e. cognitive prosthesis) than as a temporary training device. As ABI is associated with a multitude of cognitive deficits, we developed a conceptual framework, which focused on the cognitive parameters that have been shown to relate to speeding behaviour, namely “intention to speed” and “inattention to speeding”. The subjects’ combined status on the two independent parameters made up their “speeding profile”. A comparison of the speeding profiles and the speed logs indicated that ISA in the present study was more efficient in reducing inattention to speeding than affecting intention to speed. This finding suggests that ISA might be more suited for some neuropsychological profiles than for others, and that customisation of ISA for different neuropsychological profiles may be required. However, further studies with more subjects are needed in order to be conclusive on these issues.     

Dynamic capacitated lot-sizing problems: a classification and review of solution approaches

This paper presents a review of four decades of research on dynamic lot-sizing with capacity constraints. We discuss both different modeling approaches to the optimization problems and different algorithmic solution approaches. The focus is on research that separates the lot-sizing problem from the detailed sequencing and scheduling problem. Our conceptional point of reference is the multi-level capacitated lot-sizing problem (MLCLSP). We show how different streams of research emerged over time. One result is that many practically important problems are still far from being solved in the sense that they could routinely be solved close to optimality in industrial practice. Our review also shows that currently mathematical programing and the use of metaheuristics are particularly popular among researchers in a vivid and flourishing field of research.     

Quantification of dislocations in hemp fibers using acid hydrolysis and fiber segment length distributions

Natural fibers such as flax or hemp may be used in composite materials. However, their use for this purpose is hampered by the large natural variation in tensile strength and other quality parameters. The first step in managing these variations is to develop methods for fast and reliable determination of relevant parameters. One quality parameter of the fibers is the amount of structural distortions known as dislocations or kink bands. Here, a method developed for the quantification of dislocations in pulp fibers was adapted and tested successfully for hemp yarn segments. The method is based on acid hydrolysis and subsequent determination of the fiber segment length distribution. The premise of the method is that acid hydrolysis causes fibers to break in the dislocations rather than in other places. By use of polarized light microscopy and image analysis it was found that the premise was correct, and furthermore results showed that fibers broke more often in large dislocations than in small ones. However, it was also found that the hemp fiber segments did not break in all dislocations, and strict standardization of the procedure for acid hydrolysis is therefore necessary if results from different batches of fibers are to be compared.     

The effects of growth and storage conditions on dislocations in hemp fibres

Natural fibres contain structural distortions known as dislocations. Dislocations have been found to negatively affect the properties of plant fibre-based materials. The present study concerned the effect of the growth conditions of hemp plants (Cannabis sativa L.) on the amount of dislocations within the fibres retrieved from the stems. Dislocations were found in fibres from plants grown under absolutely wind-free conditions, but both windy and dry conditions introduced significantly more dislocations. Furthermore their maximum size was larger and they were situated closer together within the fibres. The average ultimate tensile stress of fibre bundles from the windy and the dry growth regimes was lower than that of fibre bundles from plants grown under wind-free conditions. In a separate study it was found that plant stems that were dried after harvest and remoistened prior to analysis contained a lower amount of dislocations than plants analysed directly after harvest.     

Diagnostic analysis of electrodialysis in mine tailing materials

Removal of heavy metals from mine tailings and soil contaminated by copper mining activities was studied under batch electrodialytic conditions. Two types of mine tailings were treated: (i) freshly produced tailings coming directly from the flotation process, and (ii) tailings deposited in a tailings pond, for approximately 20 years. The main contaminant was copper—found in concentration around 800-1800 ppm. The fractionation of copper and other characteristics of the tailings differ for the two tailings, indicating natural oxidation reactions in the old deposited ones. Electrodialytical removal results of a soil sampled close to an abandoned cupric pyrite mine—mainly polluted with lead (around 3800 ppm) are also presented. The results show that the heavy metals could be mobilized in all three contaminated solid materials using the electrodialytic process.The effect of adding different types of extracting solutions, such as distilled water, or H₂SO₄ at pH 0, H₂SO₄ + HNO₃ at pH 1.9 and 4.2 or NH₄Cl, in the electrodialytic cell, was investigated. From all the experiments, H₂O presented the best performance for the electro-removal of Cu from the old deposited mine tailings, achieving 63%. However, water removed only 15% of Pb from the soil, and no Cu from the fresh tailings. The soil fractionation of the metals before and after the experiments was evaluated by sequential chemical extractions, in order to work further on the optimization of the remediation conditions.     

Zearalenone contamination in corn for human consumption in the state of Tlaxcala,Mexico

Corn from various regions of the state of Tlaxcala, Mexico was sampled to determine whether or not corn which is consumed by humans is contaminated with the estrogenic mycotoxin zearalenone (ZEA). In order to quantify this mycotoxin, a method with adequate sensitivity using solid–liquid extraction and high-performance liquid chromatography (HPLC) with UV diode array detection was optimized. ZEA and zearalanol, used as an internal standard, were extracted from 5 g of a finely ground corn sample with an 85:15 v/v methanol:water solution, cleaned by way of a Florisil column, defatted with n-hexane, and subsequently re-extracted with chloroform. The separation was performed on a reverse phase analytical column. Detection was confirmed by on-line simultaneous UV spectral scanning during the chromatographic run. The method’s limit of detection was 0.7 ng/g and the recovery average was 90%. Analysis of 24 samples indicates that approximately 70% of the monitored samples were contaminated with zearalenone, with levels ranging from 3 to 83 μg/kg of corn kernels.     

Filtration properties of activated sludge in municipal MBR wastewater treatment plants are related to microbial community structure

In the conventional activated sludge process, a number of important parameters determining the efficiency of settling and dewatering are often linked to specific groups of bacteria in the sludge – namely floc size, residual turbidity, shear sensitivity and composition of extracellular polymeric substances (EPS). In membrane bioreactors (MBRs) the nature of solids separation at the membrane has much in common with sludge dewaterability but less is known about the effect of specific microbial groups on the sludge characteristics that affect this process.