A note on Yersinia enterocolitica in a swine farm watershed

Swine faeces from three pig farms in the La Crosse River watershed near La Crosse, Wisconsin, were sampled for Yersinia enterocolitica ; 19 presumptive isolates were recovered and biochemically confirmed as Y. enterocolitica. Simultaneously, during a 2mD2 cm rainfall, the confluences of runoff water flowing from the swine holding pens and of nearby streams also were sampled; a single isolate was obtained from one holding pen runoff-stream confluence. Biochemical analysis showed that the water isolate was a biotype identical with that of a swine isolate from the adjacent farm. These results demonstrate one possible mechanism for the introduction of Y. enterocolitica into water supplies; faecal material from swine, a suspected natural reservoir of the bacterium, is transported via runoff water to streams.     

A new Indo-Australian genus of Braconinae (Insecta, Hymenoptera, Braconidae)

Bicarinibracon gen.n. (type species Atanyco1us tricolor . Szépligeti from Papua New Guinea and Irian Jaya). Bicarinibracon luteus gen. et. 3p.n. from India and Malaya and B. lepicius gen. et. sp.n. from Thailand and the Philippines are described and illustrated. A key to the specics of Bicarinibracon is provided and its systematic placement is discussed.     

NUTRITIONAL REQUIREMENTS OF ACETOBACTER SPECIES: INORGANIC AMMONIUM SALTS AS SOURCES OF NITROGEN

SUMMARY: Forty-six strains of Acetobacter , representing twenty species, have been compared on the basis of their respective abilities to proliferate in two defined inorganic media, in which either glucose or ethanol was the sole source of carbon and energy. Twenty-three strains, representing eleven species, grew in either inorganic medium when glucose was present and nine of these strains, representing five species, could grow also in either inorganic medium when ethanol was present. The remaining twenty-three strains, representing eleven species, failed to grow in either medium with either glucose or ethanol. Three organisms grew better with ethanol than with glucose and three were inhibited by ethanol in the presence of glucose.     

Character Displacement and Acoustic Insects

Crickets, katydids, grasshoppers, and cicadas should be idealfor illustrating character displacement. Their species-specificcalling songs are of direct importance to reproductive success,and species with similar songs and overlapping ranges shoulddevelop greater differences in their songs in areas of sympatry.Although many pairs of species have suitably similar songs andoverlapping ranges and the data concerning songs are extensivefor crickets and katydids, no convincing example of characterdisplacement has been found in acoustic insects. Lack of suchexamples can be attributed to false premises, to divergencecompleted in allopatry. to elimination of geographical variationin song by gene flow between the zone of sympatry and the zonesof allopatry, and to the scanty sample that has been intensivelystudied.     

Optimization of the dilute maleic acid pretreatment of wheat straw

Background  

In this study, the dilute maleic acid pretreatment of wheat straw is optimized, using pretreatment time, temperature and maleic acid concentration as design variables. A central composite design was applied to the experimental set up. The response factors used in this study are: (1) glucose benefits from improved enzymatic digestibility of wheat straw solids; (2) xylose benefits from the solubilization of xylan to the liquid phase during the pretreatment; (3) maleic acid replenishment costs; (4) neutralization costs of pretreated material; (5) costs due to furfural production; and (6) heating costs of the input materials. For each response factor, experimental data were fitted mathematically. After data translation to €/Mg dry straw, determining the relative contribution of each response factor, an economic optimization was calculated within the limits of the design variables.