The feeding ecologies of leaf pack-associated systellognathan stoneflies were examined from 6 June 1980 21 May 1981. Species composition, seasonal abundance, nymphal growth, feeding habits and mouthpart morphology were determined for the eight dominant stonefly species. Prey preferences and predator-prey size relationships were also examined for omnivorous and carnivorous species. Foregut analysis from 2860 individuals indicated opportunistic feeding on the most abundant prey insects, usually in proportion to prey frequency. Feeding preference studies generally indicated random feeding on major prey groups. Prey and predator sizes were usually highly correlated (p<0.01), with predators expanding their prey size thresholds with growth. The potential for competition between sympatric stoneflies for prey is discussed.
Drumming is first described for five North American stonefly species, Acroneuria evoluta, Doroneuria baumanni, Isoperla namata, Chernokrilus misnomus, and Pictetiella expansa. Signals of Acroneuria lycorias, Phasganophora capitata and Isoperla signata are further described. Drumming was not recorded from Amhinemura delosa. Signals of A. evoluta are the most complex yet recorded in Plecoptera. Doroneuria baumanni, P. expanse, C. misnomus and P. capitata have 2-way exchanges. Male D. baumanni produce two prolonged beats by rubbing the hammer on the substratum; male-female signals are non-overlapping in the first two species and overlapping in the latter two. Female P. capitata answered with an unusually long sequence of beats. Two male Isoperla species produced monophasic calls without female answers. Female A. lycorias answered taped male signals with monophasic signals like all observed females.
LA31-NRK and B77-NRK are established cell lines that were normal rat kidney cells transformed with temperature-sensitive mutant (LA31) and wild-type Bratislava 77 (B77) of Rous sarcoma virus. It is recognized that many transformation-induced changes differentiate between normal and transformed cells. Morphology and four parameters of transformed cells such as saturation density, anchorage independence, plasminogen activator, and colony stimulating factor were used as indicators to observe the effect of human alpha interferon on the growth of NRK, LA31-NRK and B77-NRK. The results show that interferon could neither reverse the transformed cells to normal fashion nor change their behaviors or cause release of protease.
The high susceptibility to infection in persons with Down Syndrome (DS) has led some investigators to explore the possibility of a defect in the immune system. Studies to date indicate no defect in humoral immunity suggesting that the defect might be in the cellular immune functions, but no specific defect has been found. Our investigation of the cellular immune system of adult DS patients was conducted by examining (1) the number and function of T-lymphocytes, (2) the phagocytic function of granulocytes, (3) the level of superoxide dismutase-1 (SOD-1) in leukocytes, and (4) the effects of SOD-1 on lymphocyte and granulocyte functions.
The present study sought to falsify three distinct hypotheses about how the interactions of freshet clay turbidity with Flathead Lake may be affecting its trophic state: 1) that freshet-derived turbidity causes precipitation of organic detritus from the water column by flocculation and/or coagulation of dissolved and colloidal organic carbon and seston; 2) that flocculated clay-organic detritus complexes become increasingly infested with microbial biomass as they sink through the water column; and 3) that primary productivity is reduced and subsequently maintained at low levels throughout the summer and fall because of the phosphorus stripping action of sedimenting clay particles. In addition, this study attempted to firmly document mass balances for some ecologically important elements, nutrient loading rates, steady state nutrient concentrations and annual lake primary productivity. It was also necessary to assess the trophic status of the lake in light of any new findings from this research, especially related to the ecological role of freshet turbidity.
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