The permeability of artificial windbreaks and the distribution of flying insects in the leeward sheltered zone

The number of flying insects in the sheltered zone to leeward of artificial windbreaks of 0, 25, 45 and 70% permeability was greater than in unsheltered areas. Insects accumulated in the air nearer to dense windbreaks than to more permeable ones, and the position of maximum aerial density of insects coincided with that of maximum shelter. The more dense the windbreak the greater the numbers in the air to leeward. Absolute wind speed slightly affected the position of maximum aerial density behind a 45% permeable fence.     

Analyses of periodicity in macrobenthos using constructed and real data

Various approaches to the elucidation of periodicities in biological data sets are reviewed and evaluated. The major periodicity in a data set can be revealed by the correlogram obtained from autocorrelation analyses; knowing the main wavelength from autocorrelation, the proportion of the total variation due to a sinusoidal curve is readily obtained by multiple regression.     

Long term cycles caused by patchy predation

Simple models were developed empirically to account for possible effects of patchy annual predation upon populations of benthic species. Long-term population cycles were generated and, provided there was limited interaction among three prey species, three different cycles were obtained. With exponential or power increments in populations, the prey showed spatial aggregations, but these were less marked than those observed in nature. The failure of the models to explain certain other natural phenomena is commented upon.     

Diagnostic associations of p53 immunostaining in fine needle aspiration cytology of the breast

Duplicate cytospin preparations were made from 46 symptomatic breast fine needle aspirates. One of each pair was assigned to benign or malignant categories by one experienced observer as part of the 'triple approach'patient assessment. the other was immunostained with DO7, a monoclonal antibody to recombinant p53 protein, and rated by another observer as positive or negative for nuclear staining, unaware of the cytodiagnosis. Positive controls included carcinomas known to have mutant p53, while negative controls were of the reagent substitution type. of the 26 aspirates with a benign cytodiagnosis (verified by the triple approach), 23 were p53 protein-negative and three positive. of the 20 with a malignant cytodiagnosis (histologically confirmed), six were p53 protein-negative and 14 positive (exact P <0.0001). As a diagnostic test this would give 70% sensitivity and 88% specificity.     

The Effects of Seed Number and Prior Fruit Dominance on the Pattern of Fruit Production in Cucurbits pepo (Zucchini Squash)

Many plants, especially of species with indeterminate reproduction,show first-fruit dominance, in which the presence of developingfruit reduces future fruit maturation by increasing the abortionof later (younger) fruit and by inhibiting subsequent flowerproduction. We examined the effects of seed number on first-fruitdominance by experimentally manipulating the number of pollengrains that were deposited onto stigmas of zucchini squash andthen monitoring flower production, fruit growth, and fruit maturation.Our findings show (1) that fruits containing more seeds growfaster and achieve greater size; (2) that the presence of 6–15-d-oldfruit significantly decreases the probability of female flowerproduction while significantly increasing the probability offruit abortion; (3) that the number of seeds in the prior developingfruit has a significant effect on the probability of flowerproduction and fruit abortion, and (4) that when seed numbervaries among the fruits on a vine the fruit with the fewestseeds are the most likely to abort. It is concluded that thestrength of dominance by a developing fruit depends on the numberof seeds it contains and that this also influences the resultof fruit to fruit competition. Fruit abortion, fruit growth, Cucurbita pepo, size of pollen load, seed number, zucchini, squash     

First Records and Microhabitat Assessment of Protostelids in the Aberdare Region, Central Kenya

ABSTRACT. A rapid assessment survey on the occurrence and distribution of protosteloid amoebae was carried out in central Kenya. Samples of dead plant materials were collected from 46 study sites (each 20 × 20 m) situated along an elevation gradient (1,785–3,396 m) that encompassed five major land use/cover types. Twenty-four species and subspecific taxa were recovered and included 23 protostelids and one minute myxomycete, often included in surveys for protostelids. All of these were the first records for Kenya, and six were new for Africa. Numbers of taxa were highest in ground litter and aerial litter microhabitats (20 taxa each) and lowest on aerial bark (10) and ground bark (7). Relative species abundance was greatest in aerial litter, moderate in ground litter, and low on aerial and ground bark microhabitats. The most frequently occurring species on ground litter were Schizoplasmodiopsis pseudoendospora, Schizoplasmodiopsis amoeboidea , and Protostelium mycophaga var. mycophaga , whereas the most common species on aerial litter were P. mycophaga var. mycophaga and Soliformovum irregularis . Species richness and abundance decreased with increasing elevation.