Polychlorinated biphenyl,DDT and dieldrin residues in grey seal (Halichoerus grypus) males,females and mother-foetus pairs sampled at the Farne Islands,England, during the breeding season

PCB, DDT, DDE, dieldrin and total non-polar organohalogen residues have been determined in the blubber-lipid of grey seals (Halichoerus grypus) sampled during the 1972 breeding season (November) at the Farne Islands off the north eastern coast of England. PCBs were analysed by gas-liquid chromatography linked to a chlorine- and carbon-selective microwave plasma detector and total organohalogen residues were determined by microcoulometry.Total organohalogen residues were negatively correlated with blubber thickness and positively correlated with age in males (aged 1 to 24 y) and females (aged 5 to 38 y). However, the correlation of blubber-lipid residue with age in males depended upon the inclusion of immature (aged < 6 y) animals, and in females reflected only a small residue increment. The mean blubber organohalogen concentration of the males was significantly greater than that of the females. PCB and DDT group residue concentrations were significantly correlated.PCB, DDT, DDE and dieldrin were detected in the liver of mother/foetus pairs demonstrating transplacental movement of these residues.The possibility of the condition of the seals at breeding time influencing residue levels and of these residues influencing the health of the population is discussed.     

The internal consistency of measures of cognitive structure.

The distribution of judgments between alternative poles of a construct, derived from the grid form of the Role Construct Repertory Test, influences the interpretation of measures of cognitive structure. Investigations of the reliability of these measures have excluded the possibility that differentiation on the basis of similarity is distinct from differentiation on the basis of contrast. In the present study with 107 business school students, judgments of similarity were assumed to be different from those of contrast. The present evaluation of internal consistency, temporal stability, and construct validity for 10 measures of cognitive structure indicates that only 1 measure satisfies criteria on these 3 attributes. (French abstract) (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contribution to the study of the surface groups on carbons—II: Spectroscopic methods

Electron spectroscopy was applied to the study of a colour black (Carbolac 1) and of graphitic oxide, modified by esterification of the acidic surface groups. The deconvolution of the O_ls spectra indicates that in the case of carbon black irreversible transformations of the surface structure occur. On the contrary, for the methylated graphite oxide, a subsequent hydrolysis of the ester groups restores the original structure. IR Spectroscopy (transmission and internal reflection spectroscopies) confirms this observation: the irreversible transformation intervenes during the hydrolysis step of the methylated black.Use of a tracer technique gives direct support to the hypothesis of an enol structure which appears to become partially blocked. Possibly, the labile hydrogen involved in the keto-enol equilibrium is substituted by an alkyl group. The differences in behaviour of the surface groups of carbon black and graphite oxide can be explained on the basis of their location on solid supports having different electronic properties.     

NEIGHBORHOOD EMPOWERMENT AND URBAN MANAGEMENT IN THE 1980s

A variety of forms of neighborhood empowerment have continued to evolve during the 1970s and 1980s. At the most basic level, neighborhood organizations have shown the capability to articulate successfully community interests to both the private and public sectors. Furthermore, these organizations have also shown the capacity to administer neighborhood services and have begun to take on more comprehensive policy making functions. Recent experiences indicate that these efforts have enhanced neighborhood participation, improved the delivery of neighborhood services, and helped resolve conflicts. While the current urban fiscal crisis provides some political opportunities for extending these neighborhood efforts, neighborhood groups will have to avoid vigilantly the economic and political entrapments present in the current situation.     

Transverse properties of three-phase composites comprising continuous glass fibre,glass microspheres,and epoxy resin

Some transverse mechanical properties of composites comprising uniaxially aligned continuous glass fibres embedded in a glass microsphere-reinforced expoxy resin matrix have been determined from three-point bending experiments. For a constant fibre volume fraction, the transverse modulus, strength, fracture surface energy for crack initiation and work of fracture are investigated as a function of microsphere content and compared with the equivalent two-phase composites without beads. Modification of composite transverse properties are attributed to corresponding changes in matrix properties and comparisons are made with boundary expressions established for two-phase particulate systems. The effects of voids, microsphere size and surface treatment on the properties are also examined.     

Ultrahigh molecular weight polyethylene as used in articular prostheses (a molecular weight distribution study)

Currently there is widespread use of ultrahigh molecular weight polyethylene (UHMWPE) acetabular components in total joint replacement prostheses. What has been most surprising about the wear of UHMWPE under such circumstances is the occurrence of brittle fracture. Such fracture had not been observed in the usual engineering tests done in the laboratory on UHMWPE. It was only when prosthese which had been removed from patients were examined or run in hip joint simulators with serum or synovial fluid as the lubricant, that brittle fracture was encountered. The problem of environment-enhanced brittle fracture in plastics dates back to 1946. Interestingly, the phenomenon was first described in polyethylene. The prime variables involved are polymer molecular weight, sensitizing environment, stress filed, and temperature. Other things being equal, brittle behavior in polyethylene is extremely sensitive to the amount of low molecular weight polymer present. In the light of the foregoing we have studied the molecular weight distribution in six commercially available UHMWPE components. These were obtained from six different manufacturers. The specimens were characterized both on their bearing (wear) surfaces and in their interior bulk. The results obtained indicate that:

• 1 The UHMWPE components contain substantial amounts of low molecular weight polymer.
• 2 The UHMWPE components differ significantly in molecular weight distribution.
• 3 The UHMWPE components contain substantial amounts of crosslinked polymer.

     

A proposal of significance.

Comments that the definitiveness of significance testing is a myth. Also discussed is the doubt some investigators have cast on the objectivity of experimentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical judgment under varied informational conditions: Rorschach, personal data, and best guess.

Requested 105 psychological clinicians to make clinical judgments derived from Rorschach information and personal history data (RPD), personal history data alone (PD), or best guesses (BG) on diagnosis, anxiety, and intelligence. Compared with the BG group, the RPD group was significantly more accurate on anxiety and the PD group on diagnosis (p     

Effects of chronic alcohol ingestion on the fatty acid composition of the heart

The effects of alcohol on the total fatty acid composition of the heart have been measured, and two highly significant differences were noted between the alcohol-treated animals and the two control groups. Linoleic acid was elevated, and arachidonic acid was decreased. The increase in linoleate appeared to be a generalized increase within the various lipids analyzed, whereas the decrease in arachidonate was accounted for largely in the phosphatidyl cholines. The ratios of 20∶4ω6/18∶2 were calculated and compared to data from other researchers. The decrease in this ratio in the hearts from the alcohol-treated animals was similar to the data from the liver of animals treated with various agents which produce a fatty liver. Various mechanisms that could cause such changes in these two essential fatty acids are discussed, and it was concluded that a combination of effects could cause these changes in linoleate and arachidonate. These effects include: (a) increased mobilization of linoleate from adipose tissue; (b) decreased β-oxidation of linoleate; and (c) inhibition of the elongation-desaturation system which converts linoleate to arachidonate.