Development of an in-line rheometer suitable for reactive extrusion processes

This paper presents the development of a novel in-line extrusion rheometer based on the flow of polymer through a wedge (vertically tapered slit). This rheometer is suitable for measuring changes in rheological properties on-line during reactive extrusion, because it can be used to estimate the viscosity for a range of shear rates without the need to change the polymer flow rate (i.e., extruder throughput). Equations have been developed to estimate the parameters of the power-law equation, used to describe the viscosity-shear rate relationship, from measurements of pressure drops along the wedge. An experimental in-line wedge rheometer has been built and used to measure the viscosity for a series of polypropylenes prepared via reactive extrusion. Viscosity measurements from the experimental in-line wedge rheometer are compared with measurements from a capillary rheometer. Good agreement is found between the capillary and wedge rheometer measurements.     

Children's reasons for nominating their peers as withdrawn: Passive withdrawal versus active isolation.

Examined children's reasons for choosing peers for the withdrawal items on the Revised Class Play (RCP). 88 elementary-school children nominated peers they felt were best described by each RCP item. Reasons for their nominations were classified into 2 categories: passive withdrawal from and active isolation by the peer group. For 3 of the items ("Someone who would rather play alone than with others," "Someone who is very shy," and "Someone whose feelings get hurt easily"), the children's reasons were predominantly based on passive withdrawal, whereas for 3 other items ("Someone who is often left out," "Someone who has trouble making friends," and "A person who can't get others to listen"), they were predominantly based on active isolation. Reasons for the remaining item ("Someone who is usually sad") were split equally between both alternatives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effective parent consultation in play therapy.

Effective communication with caregivers can contribute to successful play therapy outcomes. This article examines the structure of parent consultation in play therapy. The components of effective parent consultation are outlined, from the initial phone interview through termination, to provide guidance to play therapists for communicating with caregivers throughout the therapy process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social and social-cognitive correlates of sociometric status in preschool and kindergarten children.

Sociometric popularity was determined for 123 preschoolers and 111 kindergartners. Each S was then observed during free play for 6 10-sec time samples, each day, over 30 days for preschoolers and 25 days for kindergartners. The level of social and cognitive play observed was recorded, as well as the S's conversational partners, the initiator of the activity, and the affective quality of each social interchange. Social competence (as rated by teachers) and social problem-solving ability were also assessed. Analyses revealed peer rejection to be consistently related to agonistic behavior. Second, unpopular Ss were observed to engage in less mature forms of play and to interact less with others than were their more popular agemates. (French abstract) (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantification of cytokines involved in wound healing using surface plasmon resonance

Sensing of three cytokines related to chronic wound healing, interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha), with detection limits at or below 1 ng/mL in buffered saline solution and spiked cell culture medium (CCM) has been achieved. Fiber-optic surface plasmon resonance (SPR) sensors are coated with an antibody binding layer and antibodies specific to the cytokine of interest are covalently attached to this layer. To achieve such detection limits in a complex medium such as CCM, total protein content of 4 mg/mL, the use of a novel N-hydroxysuccinimide ester of 16-mercaptohexadecanoic acid (NHS-MHA) is necessary. A comparison of the detection limits for IL-6 using currently widely used CM-dextran and NHS-MHA shows an improvement by a factor of 3 using NHS-MHA. The detection limits for the monitoring of cytokines in spiked saline solutions and CCM were similar for TNF-alpha and slightly higher for IL-1 and IL-6. The detection of each cytokine in the presence of interfering agents resulted in concentration prediction well within the error of calibration. The SPR sensors are stable in CCM after 20 min of pretreatment in CCM, minimizing the reliance on a reference sensor to quantify the cytokines in complex media. This technique enables a major advancement in the field of real-time monitoring of biologically relevant molecules in complex biological fluids.     

Eelgrass as a Bioindicator Under the European Water Framework Directive

Eelgrass is the most widespread plant in temperate coastal waters. It is regarded as a useful indicator of water quality because water clarity regulates its extension towards deeper waters, i.e. the depth limit. This study analyses the use of eelgrass depth limits as a bioindicator under the Water Framework Directive (WFD). The WFD demands that ecological status is classified by relating the actual level of bioindicators to a so-called reference level, reflecting a situation of limited anthropogenic influence. The directive further demands that reference levels are defined for water body types with similar hydromorphological characteristics, and that the classification thereby becomes type-specific.A large historic data set on depth limits of eelgrass around 1900 was used to characterise reference levels, and a large data set from the Danish National Monitoring and Assessment Programme to characterise actual depth limits. Data represented a wide range of Danish coastal water bodies that were grouped into 10 water body types based on differences in salinity and water depth.The analyses clearly illustrate that the definition of ecological status classes markedly influence the assessment of ecological status according to the WFD. Moreover, the study demonstrates that the use of type-specific classification implies a risk of misinterpreting ecological status. Classification problems were pronounced in spite of a unique data material on reference conditions, and the problems are likely to be even greater in cases where reference conditions are less well defined. A more robust classification was obtained by using reference levels for individual sites in a site-specific classification.In conclusion, when classifying water quality on the basis of eelgrass depth limits, site-specific reference levels are recommended if such data are available. If more general information on reference levels is used, local conditions known to affect depth limits must be taken into account.     

Long-term sequelae of childhood sexual abuse: Perceived family environment, psychopathology, and dissociation.

105 abused and nonabused women were examined for patterns of adult psychopathology associated with childhood sexual abuse and to test the extent to which these patterns are independent of other pathogenic properties of the family environment. Clinical and nonclinical Ss completed the Family Environment Scale, the MMPI, the Rorschach, and the Stanford Hypnotic Susceptibility Scale. Greater nonspecific impairment among abused women may be a consequence, at least in part, of pathogenic family structure rather than sexual abuse per se. However, MMPI and Rorschach responses suggest sexual abuse may render victims especially vulnerable to specific disturbances involving soma and self. Abuse was associated with greater use of dissociation, but covariance analysis revealed this effect to be accounted for by family pathology. There was no evidence that sexual trauma is associated with hypnotizability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermochemistry and Aqueous Durability of Ternary Glass Forming Ba-Titanosilicates: Fresnoite (Ba2TiSi2O8) and Ba-Titanite (BaTiSiO5)

Barium titanosilicates are possible oxide forms for the immobilization of short-lived fission products in radioactive waste. Ba₂TiSi₂O₈ (fresnoite) and BaTiSiO₅ (Ba-titanite) samples were prepared by a solid-state synthesis. The enthalpies of formation of Ba₂TiSi₂O₈ crystal and glass at 25°C and of BaTiSiO₅ glass were obtained from drop solution calorimetry in a molten lead borate (2PbO–B₂O₃) solvent at 701°C. The enthalpy of formation for fresnoite composition samples from constituent oxides was exothermic and became more exothermic with increasing crystallinity. Differential scanning calorimetry revealed that the crystallization rate of the fresnoite glasses increased with increasing devitrification. A modified Product Consistency Test-Procedure B (PCT-B) was used to collect solubility data on the fresnoite and titanate phases. The tests suggest that both glassy and crystalline fresnoite exhibit favorable aqueous stability and should be explored further as radioactive waste forms for long-term storage.     

Maternal dietary habits and mycotoxin occurrence in human mature milk

During 2006, 82 samples of human mature milk were collected at Italian hospitals and checked for aflatoxin M1 (AFM1) and ochratoxin A (OTA) by immunoaffinity column extraction and HPLC. AFM1 was detected in four (5%) of milk samples (ranging from < 7 ng/L to 140 ng/L; mean level: 55.35 ng/L); OTA was detected in 61 (74%) of milk samples (ranging from < 5 ng/L to 405 ng/L; mean level: 30.43 ng/L. OTA levels were significantly higher (p less, not double equals 0.05) in milk of habitual consumers of bread, bakery products and cured pork meat. No other statistically significant differences were observed although habitual consumers of pasta (p = 0.059), cookies (p = 0.061) and juices (p = 0.063) had mean contamination values of OTA higher than the moderate consumer. The very few AFB1 positive samples did not allow statistical comparisons. The present study confirms that the occurrence of OTA in human milk is related to maternal dietary habits. The findings support the possibility of dietary recommendations to woman, during pregnancy and lactation, aimed to tentatively reduce the OTA contamination of human milk.