The taste, odor and hedonic quality of polyglycerols

Twenty subjects judged the taste and odor intensity and thetaste and odor pleasantness/unpleasantness of five concentrationsof sucrose, glycerol, a commercial triglycerol, a syntheticlinear diglycerol and a synthetic linear triglycerol. Judgmentsof intensity were made using the method of magnitude estimation;judgments of pleasantness/unpleasantness were made using a graphicline scale. Only the two linear polyglycerols had appreciableodor intensity. Both were described as having an ‘acrid’or ‘burnt caramel’ quality. The odor exponent forthe linear triglycerol was extremely high (1.44) and may beattributed to its intensely unpleasant quality. Sucrose wascharacterized solely by sweet taste, glycerol and the commercialtriglycerol by sweet and bitter tastes, the linear diglycerolby sweet, bitter and sour tastes, and the linear triglycerolby bitter and sour tastes. The relationships between perceivedtaste intensity and concentration were well described by powerfunctions, although the slope of the psychophysical functionfor the linear triglycerol was markedly lower than that forthe other compounds. The relative order of taste intensitieswas: linear triglycerol > sucrose > glycerol = lineardiglycerol > commercial triglycerol. Judgments of taste (andodor) pleasantness/unpleasantness showed only sucrose and glycerolto have positive hedonic qualities. All the polyglycerols werejudged unpleasant at all concentrations. Differences in thetaste and odor characteristics of the commercial and synthetictriglycerols were attributed to the commercial product beinga mixture of over 20 compounds. Although the synthetic lineardi- and triglycerols are effective in lowering water activity,these data suggest that more purified crystalline forms mustbe synthesized before they can be used effectively as humectantsfor intermediate moisture foods.     

Inflammatory Bowel Disease Among College Students

Of 52 student patients with chronic inflammatory bowel disease who were observed at Stanford University over a three-year period, 16 had Crohn disease, 17 had ulcerative colitis and 19 had ulcerative proctitis. Patients with ulcerative colitis had relatively few complications. During the study period, only two students from the entire group of 52 were obliged to interrupt college attendance because of bowel disease or complications. Of the patients, 33 were first observed on remission or attained remission during the three-year observation period. Incidence and prevalence rates for Crohn disease and ulcerative colitis were comparable with age-specific rates from other published studies. At Stanford, the high reported frequency of proctitis, which exceeded that of proximal ulcerative colitis, was possibly a reflection of the diagnostic zeal with which patients with rectal bleeding were evaluated at the student health service.     

T lymphocyte subsets in patients with malignant melanoma

Summary T lymphocyte subset profiles were determined by monoclonal antibodies on cryopreserved peripheral blood lymphocytes from 57 patients with malignant melanoma and 19 healthy controls. Quantitation of percentages of total T cells (OKT3.PAN), helper (OKT4.IND) or suppressor (OKT8.SUP) cells, and the ratio of helper/suppressor subsets revealed no correlation of these markers with stage of disease or clinical outcome. A sequential study of these markers on peripheral blood lymphocytes from three stage I melanoma patients with subsequent recurrent disease showed no fluctuations that could be correlated to tumor progression. This study indicates that there is no systemic imbalance in T cell subsets in malignant melanoma and that quantitation of these subsets cannot predict the clinical course of this disease.     

Susceptibility of California gastropods to an introduced South African sabellid polychaete, Terebrasabella heterouncinata

Abstract. The outer surfaces of the shells of living marine gastropods are often colonized by other organisms. However, only one species, the sabellid worm Terebrasabella heterouncinata , is able to settle in the aperture of living gastropods. Native to South Africa, and introduced to California, this worm is a pest of abalone aquaculture and has been a threat to native gastropods in California. We investigated the intrinsic susceptibility of 15 marine gastropods from California to this apertural fouling organism. Intrinsic susceptibility was significantly different among gastropod species. Overall, caenogastropods tended to be more resistant than were the vetigastropods and patellogastropods. This suggests that variability in susceptibility could be due to characteristics associated with closely related gastropod hosts. However, this only partially explained the variation in susceptibility to individuals of T. heterouncinata . Intrinsic susceptibility was not associated with potential host species from similar habitats. We discuss host susceptibility to T. heterouncinata , including implications for potential control of this pest species, and for understanding factors enabling this polychaete to inhabit the apertural region, an area typically free of all other epibionts.     

Quelques apports à la théorie de l’Évolution,de la « Synthèse orthodoxe » à la « Super synthèse évo-dévo » 1970–2009 : un point de vue

Some contributions to evolutionary theory, from the “orthodox” Synthesis to the “Evo-devo Super synthesis” 1970–2009: A point of view. The “Modern Synthesis” of evolutionary biology coalesced and revitalized evolutionary theory beginning in the 1930s. It stressed the explanatory power of natural selection and gradual change to account for the processes that govern natural populations today, as well as patterns in the history of life. In the past 40 years, the synthesis has been challenged on various fronts ranging from paleontology to developmental biology, systematics, biogeography, and molecular and developmental biology. Several of its central propositions have been modified and expanded as a result. How well the synthesis continues to be effective will depend on its continued ability to test its central propositions and the efficacy of its central mechanisms, particularly on the basis of new evidence from emerging fields of study.