Variation of the rfb gene clusters in Salmonella enterica

In order to explore the genetic variation of O antigens of Salmonella enterica, we surveyed 164 strains (132 serovars) belonging to 45 serogroups, using 25 mostly single-gene rfb DNA probes for colony hybridization. The results revealed that strains within a serogroup have very similar or identical rfb genes. At least three of the four rhamnose genes were detected in all 17 serogroups reported to contain rhamnose, and one or more were detected in three others. The likelihood of being detected decreased in the order rfbB, rfbC, rfbA, and rfbD, which is the map order, suggesting a gradient of divergence. Mannose pathway genes were much less conserved, and of 27 groups reported to contain mannose or mannose derivatives colitose or fucose, only 9 hybridized to the rfbM and rfbK probes. Dideoxyhexose genes were found only in groups reported to contain dideoxyhexoses. Group D2, which had not been studied previously, appears to resemble group D1, with the substitution of one gene from group E1 to give a change in one linkage. In contrast to sugar pathway genes, sugar transferase genes did not in general hybridize to strains of other groups outside the closely related groups A, B, and D, with the exception of the galactose transferase gene also shared by groups C2, C3, and all E groups.     

Asymmetry in bicycle ergometer pedalling

The effects of changes in speed and resistance setting on the bilateral symmetry of work output on the bicycle ergometer were studied. The cranks of a Monarch bicycle ergometer were instrumented with foil strain gauges and the bridge outputs were integrated on-line and analyzed by a program running in a Hewlett Packard 2115A computer. Twenty male subjects performed three thirty-second trials at each of nine speed and resistance combinations. Indices of asymmetry from 66-178 were found using kicking dominance (n = 20) and 56-135 using a strength dominance classification (n = 13). Day to day reliability of the index of asymmetry was found to be only 0.47; within day reliability was 0.87 for day one and 0.79 for day two. No significant effects for speed or resistance changes were shown on either day for the strength dominant subjects. When kicking dominance was considered main effects were encountered on both days for speed although there was no clear directional trend. The findings of these experiments have important implications for studies where measurements are made on the lower extremity during cycle ergometer exercise, and for competitive cyclists engaged in endurance competition.     

Plant trash in linters and willowed picker: materials used in the cotton garnetting industry

First cut linters and willowed picker, used in cotton garnetting, were examined for content of cotton bract an other plant trash. Bract was found to be a minimal contaminant of the trash of first cut linters. A significant amount of bract (about 9% of the trash) was present in willowed picker. Cotton seed hulls, a valuable oil mill by product, contained an insignificant amount of bract trash.     

The menstrual cycle and response to erotic literature

133 undergraduate females responded to a pre-experimental questionnaire assessing their contraceptive use (28% on contraceptive pills), sexual experience (71% had had sexual intercourse), and present phase of menstrual cycle. Ss then read an erotic story intended to induce sexual arousal. Results of a self-report postexperimental questionnaire assessing sexual arousal and genital stimulation show no significant response differences based on menstrual cycle phases for Ss not using contraceptive pills. Greatest degree of arousal and sensation was experienced by Ss on contraceptive pills who were in the menstrual phase of the cycle; least arousal and sensation was experienced by Ss on contraceptive pills who were in the premenstrual phase of the cycle. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ultrastructure of the spermatozoa and spermiogenesis in New Zealand freshwater eels (Anguillidae)

The spermiogenesis and sperm ultrastructure of Anguilla australis schmidtii and A. dieffenbachii is described. During spermiogenesis the chromatin material condenses into the crescent-shaped head of the mature sperm. By elongation of the sperm head the mitochondrion is displaced to the anterior of the head remote from the posterior centriolar apparatus. A ciliary rootlet becomes segregated during spermiogenesis to form a membrane covered, striated, rod-like appendage. From the proximal centriole arise two sets of filaments, each containing three subfibrils. One group of five filaments extends anteriorly along the inner concave side of the head. A group of four modified filaments pass along the outer, convex, side. The middle subfibril B of each triplet in the group of four filaments is flattened and joins the two subfibrils A and B, forming a binocular shaped structure. The motile flagellum has a 9+0 axonemal pattern.     

Acute poststreptococcal glomerulonephritis mimicking Henoch-Sch?nlein purpura

Two children with acute glomerulonephritis, cutaneous vasculitis, and abdominal pain are reported. One child also had transient arthralgia and gastrointestinal hemorrhage. Although the clinical presentation mimicked many of the features of Henoch-Sch?nlein purpura, both patients had unusual variants of poststreptococcal glomerulonephritis.