The Use of Polyvalent Sera for the Serotyping of Mycobacteria within the Mycobacterium avium– M. intracellulare-M. scrofulaceum Complex

A modification to Schaefer's agglutination method for serotyping mycobacteria within the Mycobacterium avium-M. intracellulare-M. scrofulaceum complex is described. The antigens are screened against polyvalent sera and subsequently a reduced range of absorbed antisera. This expedites the serotyping procedure and conserves expensive antiserum stocks.     

Critical Inuit Studies: An Anthology of Contemporary Arctic Ethnography

Critical Inuit Studies: An Anthology of Contemporary Arctic Ethnography . Pamela Stern and Lisa Stevenson, eds. Lincoln: Nebraska University Press, 2006. 302 pp.     

Lignin degradeation by white rot fungi

Abstract. The wood-degrading white-rot fungus Phanerochaete chrysosporium , has been the subject of intensive research in recent years and, based upon isolation of the extracellular enzyme ligninase, major advances have now been made toward elucidating the mechanism by which this fungus degrades lignin. From these developments, a model emerges which could explain the process by which wood-degrading fungi in general, attack lignin.     

Microgeographic distribution of immature Ixodes dammini ticks correlated with that of deer

In order to determine whether the small-scale distribution of immature Ixodes dammini Spielman et al. corresponds closely to the activity patterns of white-tailed deer, Odocoileus virginianus (Zimmerman), these relationships were examined in a site on Long Island, New York, U.S.A. We first determined the extent and temporal pattern of adult ticks feeding on deer by examining twenty-three resident deer tranquilized during September-December 1985. I. dammini adults infested deer throughout this fall period, most abundantly during October and November. With radio-telemetry collars attached to deer we determined the relative frequency that they occupied 0.25 ha quadrats of the study site. During the following summer, we examined white-footed mice, Peromyscus leucopus (Rafinesque), that inhabited these quadrats and removed immature ticks from each. 8975 larval and 163 nymphal I. dammini were removed from 208 mice trapped in forty-three such quadrats. The frequency of deer using these quadrats was positively correlated with both the number of larval and of nymphal ticks per mouse. These results suggest that risk of I. damminiborne zoonotic disease may be decreased by locally reducing deer density in sites that experience intense human activity.     

The Influence of Carbon Dioxide and Daily Photon-flux Density on Optimal Leaf Nitrogen Concentration and Root: Shoot Ratio

Using a cost-benefit model, the leaf nitrogen concentrationand root : shoot ratio that maximize whole-plant relative growthrate are determined as a function of the above-ground environment(integrated daily photon flux density and the concentrationof carbon dioxide at the site of fixation within the leaf).The major advantage of this approach is that it determines theadaptive significance of leaf physiology by considering thefunctional integration of leaves and roots. The predicted responseto increasing daily photon flux densities is an increase inoptimal leaf N concentration (N_opt) and a concomitant increasein root: shoot ratio. Increased carbon dioxide concentrations,on the other hand, reduce N_opt and only slightly change root:shoot ratio. The observed increase in leaf nitrogen concentrationfound in plants growing at high altitudes (low CO₂ partial pressure)is also predicted. Since these responses to light and CO₂ maximizethe whole-plant relative growth rate, the observed adjustmentsthat plants make to light and carbon dioxide concentration appearto be adaptive. We show that the relationship between photosynthesis and leafnitrogen concentration is complex and depends on the light andCO₂ levels at which photosynthesis is measured. The shape ofthis function is important in determining N_opt and the oppositeresponse of leaf nitrogen to light and carbon dioxide is shownto be the result of the different effects of light and CO₂ onthe photosynthesis-leaf nitrogen curve. Plant growth, photosynthesis, leaf nitrogen, biomass allocation, optimization, carbon dioxide light     

Fluorescein-Conjugated Folate as an Indicator of Specific Folate Binding to Paramecium1

Normal Paramecium tetraurelia cells stained with fluorescein-conjugated folate show intense fluorescence that can be reduced to near background autofluorescence with excess K₂-folate, but not with excess KCl. Mutant d4–534, which is not attracted to folate and does not specifically bind ³H-folate, shows reduced fluorescence when stained. This method of monitoring specific folate binding to cells can be adapted to a microscale for rapid screening of clones since cells are routinely fixed and stained in microtiter wells.     

Permeability to Water of the Fibre Cell Wall Material of Two Hardwoods

The permeability to water of the fibre cell wall of birch (Betulapubescens Ehrh.) and lime (Tilia x vulgaris Hayne) wood, wasmeasured in wood slices in which most of the void space wasfilled with paraffin wax or a polymerizing silicone elastomer.An osmotic technique was used with solutes of molecular weightgreat enough to prevent their molecules from penetrating thepores in the water-swollen cell wall. The solutes used weredextran and polyethylene glycol with molecular weights of 40000 and 6000 respectively. Values for permeability k x 10²¹, as defined by the Darcy equation,ranged between 3.6 m² for the tangential direction in birch,to 27 m² for the longitudinal direction in birch. These resultsare in good agreement with previously measured values but areat least ten times less than theoretical values. It is calculatedthat total emptying or filling of a wood cell through the wallmight be possible in as little as 5 min under a pressure differenceof 0.1 MPa if other flow pathways were blocked. Key words: Betula pubescens, Tilia x vulgaris, Water permeability, Fibre cell wall     

Experimental Histomoniasis in the Guinea Fowl,Numida meleagris*

Guinea fowl were inoculated rectally with Histomonas meleagridis to produce histomoniasis. The birds were infected readily by this unnatural route. Severe cecal involvement was frequent and long-lasting but liver lesions and death were rare. Turkeys given the same inoculum had high levels of liver involvement and mortality. Guinea fowl responded much less severely to infection with H. meleagridis when infected by a natural route (ingestion of a vector) rather than by rectal inoculation. Thus, naturally acquired infections with H. meleagridis appear to be of small consequence in the guinea fowl.