Moisture migration in idealized bilayer systems: relationships among water-associated properties, structure, and texture

The effects of composition and thermal treatment on the water sorption and diffusional properties of idealized protein gels arranged in bilayer configurations were determined; these water binding/migration properties were related to the mechanical characteristics of the gels. Samples were prepared from whey protein concentrate (WPC), they consisted of water:WPC ratios of 1.5 to 5.67, and were thermally set for 20–60 min. Moisture migration rates from samples interfaced with filters were determined, as were moisture sorption capacities of samples immersed in water. The physical properties of the gels were assessed by uniaxial compression and microscopy. Results showed that gel strength and consequent extent of protein interaction—as affected by thermal treatment—controlled the ability of the gel structure to absorb water. Sorption was exponentially correlated with gel modulus and linearly correlated with a function of protein content, heating time, and immersion time. Rates of diffusion from interfaced gels were dependent solely on water content. It was concluded that the degree of protein interaction, whether influenced by concentration or thermal treatment, affected network extensibility and thus the capacity of the gels to act as receptors of moisture. Results have implications for the functionality of shelf-stable sandwiches and other multicomponent foods.     

Multifocal primary neuroblastoma

The purpose of this study is to present three patients with multifocal primary neuroblastoma, to review the literature, and describe the radiographic findings. SUBJECTS AND METHODS: Three children with multifocal neuroblastoma have been identified. The case histories and imaging findings in these patients are reviewed. RESULTS: Two children had synchronous and one child had metachronous multifocal primary neuroblastoma. The primary tumors were both in the abdomen in one patient, both in the chest in another patient, and in the chest and abdomen in the third patient. Evidence for multifocal origin of these tumors, rather than metastatic spread, is presented. CONCLUSION: Multifocal primary neuroblastomas can occur. The tumors maybe synchronous or metachronous. Awareness of this disorder may prevent errors in diagnosis and staging. Although not identified in our patients there is a strong familial incidence of neuroblastomas in those patients with multifocal tumors.     

Factors limiting the domestic density of Triatoma infestans in north-west Argentina: a longitudinal study

Reported are the environmental and demographic risk factors associated with the domestic infestation and density of Triatoma infestans in three heavily infested rural villages in Santiago del Estero Province, Argentina. In a one-factor unadjusted analysis, the number of T. infestans captured per person-hour was associated significantly and negatively with the use of domestic insecticides by householders, type of thatch used in the roofs and the age of the house; and positively with the following: degree of cracking of the indoor walls and presence of hens nesting indoors. In one model, using multiple linear regression and a backward stepwise elimination procedure, most of the variation in the overall abundance of T. infestans was explained by insecticide use and the presence of hens nesting indoors; in another model using the same procedure it was explained by insecticide use, bug density in 1988 and previous spraying with deltamethrin in 1985. Variations in bug density per capture stratum (household goods, beds, walls and roof) were explained by the bug density in other strata and by one or two of the following risk factors: hens nesting indoors, type of roof, presence of cracks in the walls and number of people living in the house. Bug density might be locally controlled by the availability of refuges in the roofs and walls, by the presence of hens nesting indoors and by the use of domestic insecticides. Certain local materials, such as a grass known as simbol, could be successfully used in rural housing improvement programmes aimed at reducing the availability of refuges for insects in the roof.     

Simultaneous measurement of opiate-induced histamine release in the periaqueductal gray and opiate antinociception: an in vivo microdialysis study

Histamine release and the subsequent activation of H2 receptors in the periaqueductal gray (PAG) are thought to be important components of morphine antinociception. In vivo microdialysis and antinociceptive testing were simultaneously applied in rats to characterize the effects of morphine on PAG histamine release and determine the relationship between histamine release and antinociception. In the absence of nociceptive (tail pinch) testing, morphine (12.8 mg/kg) induced a delayed, long-lasting release of histamine in the PAG. This effect of morphine was abolished by the opiate antagonist naltrexone (1 mg/kg) but was not mimicked by the mu-preferring agonist fentanyl (0.3 mg/kg), suggesting that activation of an opiate receptor other than, or in addition to, the mu receptor is necessary. In contrast to the findings with fentanyl in untested animals, fentanyl combined with nociceptive testing increased histamine release, even though testing alone had no such effect. Unexpectedly, tail pinch testing inhibited morphine-induced histamine release. These results show that the test procedure alters the action of opiates on histamine release, an effect likely to be the result of the stress of repeated tail pinch testing. Therefore, although histamine release may not be obligatory for all types of opiate antinociception, histamine in the PAG may function as a mediator of stress-induced potentiation of opiate antinociception. Even though the microdialysis technique has been acclaimed for its ability to assess neurochemical and behavioral characteristics simultaneously, the introduction of nociceptive testing clearly can alter the neurochemical systems under study.     

Mass transfer across wind-sheared interfaces

A predictive analogy of turbulent mass transfer across wavy, sheared air-water interface, in deep water bodies is proposed. The theory is based on the formulation of a theoretical eddy diffusivity profile in the surface region, and it applies to the non-breaking wave regime. The predictions for a water-side friction velocity range of 0.5–6 cm/s are in excellent agreement with laboratory data from wind-wave facilities with an average error of 15.4%.     

Stability of formal thought disorder and referential communication disturbances in schizophrenia.

This study examined the degree to which different types of communication disturbances in the speech of 48 schizophrenia patients and 28 controls were variable and state related versus stable and traitlike. Clinically rated formal thought disorder and 5 types of referential disturbance showed substantial stability within participants over time. The sixth type of referential disturbance, the vague reference, was not stable over time. Formal thought disorder was associated with the severity of core psychotic symptoms in patients, whereas referential disturbances showed little or no association with positive or negative symptom severity. Furthermore, changes in psychotic symptoms over time were accompanied by corresponding changes in formal thought disorder but not referential disturbances. These results support the idea that some types of referential disturbances are traitlike and may be reflective of vulnerability as well as manifest illness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New Tractable Classes From Old

The constraint satisfaction problem is known to be NP-hard in general, but a number of restrictions of the problem have been identified over the years which ensure tractability. This paper introduces two simple methods of combining two or more tractable classes over disjoint domains, in order to synthesise larger, more expressive tractable classes. We demonstrate that the classes so obtained are genuinely novel, and have not been previously identified. In addition, we use algebraic techniques to extend the tractable classes which we identify, and to show that the algorithms for solving these extended classes can be less than obvious.     

How infants perceive a simple causal event.

Four experiments examined 10-mo-old infants' causal event perception. Exp 1 replicated previous studies except that the specific objects used as agent and recipient varied from trial to trial. Under these conditions infants did not process the causality. Instead they keyed on specific temporal and spatial differences among the events. Exp 2 showed that infants notice a change in the particular agent performing either a causal or noncausal action. Exp 3 showed that infants do not notice a change in the type of action done to a particular recipient. Exp 4 demonstrated that infants do not pay attention to the object used as a recipient. As a whole, the results indicate that 10-mo-old infants perceive the causality of simple events by associating a specific agent with the causal action. These results provide more support for an information-processing view than for the view that infants have a causal module. (PsycINFO Database Record (c) 2010 APA, all rights reserved)