Populations of ants in a Missouri Woodland

Summary Populations of ants were studied in a mixed oak-hickory woods in St. Charles County, Missouri. Forty plots of soil, each measuring a yard square, were dug during the fall, winter, and spring, and records were kept of the species of ants, number of colonies, types of nests and hibernating conditions.Sixteen species of ants, making up 204 colonies, were found in the plots. The common species wereAphaenogaster rudis (62 colonies),Ponera eorctata pennsylvanica (40 colonies), andAmblypone pallipes (39 colonies). Rare, underground species found by this method includedSysphincta pergandei, Proceratium silaceum, and a new species ofStenamma (S. meridionale).

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Zusammenfassung Bevölkerungen der Ameisen eines Mischwaldes von Eichen und nordamerikanischer Wallnuszbäumen in St. Charles County, Missouri wurden untersucht. Vierzig Grundstücke, je ein Meter quadrat wurden während des Herbstes, des Winters, und des Frühlings ausgegraben, und schriftliche Berichte über die Spezies des Ameisen, Zahl der Kolonien, Grundform der Neste, und Zustände für Winterschlaf aufgezeichnet.Es gab in diesen Grundstücken sechzehn Spezies in 204 Kolonien der Ameisen. Die gewöhnlichen Spezies warenAphaenogaster rudis (62 Kolonien),Ponera coarctata pennsylvanica (40 Kolonien), undAmblypone pallipes (39 Kolonien). Seltene Untergrundspezies durch diese Methode gefunden schlieszenSysphincta pergandei, Proceratium silaceum, und eine Spezies derStenamma (S. meridionale) ein.

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Résumé L'auteur étudie de nombreuses populations de fourmis, habitant un bois composé de chênes et de hickorys dans le comté de St. Charles, État du Missouri. Au cours de l'automne, de l'hiver et du printemps, on pratiqua des fouilles dans quarante parcelles de terre, d'un mètre carré chacune, en notant les observations suivantes: espèces de fourmis, nombre de colonies, genres de nids et conditions d'hibernation.Parmi les 204 colonies découvertes dans les parcelles, on trouva seize espèces de fourmis. Les espèces communes étaient:Aphaenogaster rudis (62 colonies),Ponera coarctata pennsylvanica (40 colonies) etAmblypone pallipes (39 colonies). Parmi les espèces rares et souterraines trouvées par ce procédé, il y avaitSysphincta pergandei, Proceratium silaceum et une nouvelle espèce deStenamma (S. meridionale).

     

Culture and long-distance shipment of swine embryos 1

Embryo culture techniques were used to maintain the viability of swine embryos during shipment from the United States to England. Embryos recovered surgically from Chester White and Hampshire sows and gilts were shipped to England, then transferred to Large White gilts. Estrus was synchronized between donors and recipients by including allyl trenbolone in the daily feed for 18 and 17 consecutive days, respectively. Daily dose of allyl trenbolone was 15 mg for recipients and either 15 or 20 mg for donors. Donors were mated or artifically inseminated one to three times during estrus. During shipment, embryos were cultured in groups of six to ten in polystyrene tubes (12 × 75 mm) containing 2 ml of a modified Krebs-Ringer bicarbonate medium. The gas phase was 90% nitrogen, 5% oxygen, and 5% carbon dioxide. Culture temperature was maintained at 35 C with a temperature-controlled box, and shipment was by commerical airline. Embryos were inserted into recipient uteri 20.5 to 27 hr after recovery. In total, 227 eggs were transferred to 12 recipients, resulting in the birth of seven litters totaling 58 pigs.     

Biosynthesis of hopanoids by sulfate-reducing bacteria (genus Desulfovibrio)

Sulfate reduction accounts for about a half of the remineralization of organic carbon in anoxic marine shelf regions. Moreover, it was already a major microbial process in the very early ocean at least 2.4 billion years before the present. Here we demonstrate for the first time the capability of sulfate-reducing bacteria (SRB) to biosynthesize hopanoids, compounds that are quantitatively important and widely distributed biomarkers in recent and fossil sediments dating back to the late Archean. We found high concentrations (9.8-12.3 mg per gram of dry cells) of non-extended and extended bacteriohopanoids (bacteriohopanetetrol, aminobacteriohopanetriol, aminobacteriohopanetetrol) in pure cultures of SRB belonging to the widely distributed genus Desulfovibrio. Biohopanoids were found--considered as membrane rigidifiers--in more than 50% of bacterial species analysed so far. However, their biosynthesis appeared to be restricted to aerobes or facultative anaerobes with a very few recently described exceptions. Consequently, findings of sedimentary hopanoids are often used as indication for oxygenated settings. Nevertheless, our findings shed new light on the presence of hopanoids in specific anoxic settings and suggests that SRB are substantial sources of this quantitatively important lipid class in recent but also past anoxic environments.     

Isolation and characterization of microsatellite loci in the intertidal sponge Halichondria panicea

GA‐ and CA‐enriched genomic libraries were constructed for the intertidal sponge Halichondria panicea. Unique repeat motifs identified varied from the expected simple dinucleotide repeats to more complex repeat units. All sequences tended to be highly repetitive but did not necessarily contain the targeted motifs. Seven microsatellite loci were evaluated on sponges from the clone source population. All seven were polymorphic with 5.43 ± 0.92 mean number of alleles. Six of the seven loci that could be resolved had mean heterozygosities of 0.14–0.68. The loci identified here will be useful for population studies.     

Effect of fluid mechanical stresses and plasma constituents on aggregation of LDL

LDL aggregates when exposed to even moderate fluid mechanical stresses in the laboratory, yet its half-life in the circulation is 2-3 days, implying that little aggregation occurs. LDL may be protected from aggregation in vivo by components of plasma, or by a qualitative difference in flows. Previous studies have shown that HDL and albumin inhibit the aggregation induced by vortexing. Using a more reproducible method of inducing aggregation and assessing aggregation both spectrophotometrically and by sedimentation techniques, we showed that at physiological concentrations, albumin is the more effective inhibitor, and that aggregation is substantially but not completely inhibited in plasma. Heat denatured and fatty-acid-stripped albumin were more effective inhibitors than normal albumin, supporting the idea that hydrophobic interactions are involved. Aggregation of LDL in a model reproducing several aspects of flow in the circulation was 200-fold slower, but was still inhibited by HDL and albumin, suggesting similar mechanisms are involved. Within the sensitivity of our technique, LDL aggregation did not occur in plasma exposed to these flows. Thus, as a result of the characteristics of blood flow and the inhibitory effects of plasma components, particularly albumin, LDL aggregation is unlikely to occur within the circulation.