Effect of host species,host nest density and nest size on the occurrence of the shining guest ant <Emphasis Type="Italic">Formicoxenus nitidulus</Emphasis> (Hymenoptera: Formicidae)

Understanding habitat requirements of species is important in conservation. As an obligate ant nest associate, the survival of the globally vulnerable shining guest ant, Formicoxenus nitidulus, is strictly tied to that of its hosts (mound building Formica ants). We investigated how host species, nest density, inter-nest distance and nest mound size relate to the occurrence of F. nitidulus. In total, 166 red wood ant nests were surveyed in SW Finland (120 Formica polyctena, 25 F. rufa, 14 F. aquilonia, 5 F. pratensis, and 2 F. lugubris). Overall, F. nitidulus was found in 60% of the nests. For the actual analysis, only F. polyctena and F. rufa nests were included due to the small number of other nests. F. nitidulus was more likely to be found among F. polyctena than F. rufa. Also, while inter-nest distance was not important, a high nest density, commonly found in polydomous (multi-nest) wood ant colonies, was beneficial for F. nitidulus. The guest ant was also more likely to be found in large host nests than small nests. Thus, our results show that the best habitat for the guest ant is a dense population of host nest mounds with a high proportion of large mounds. Conservation efforts should be directed at keeping the quality of the red wood ant habitats high to preserve their current populations and to increase colonization. This will not only benefit the guest ant, but also a plethora of other species, and help in maintaining the biodiversity of forests.     

Investigation of the Stabilizing Effects of Antioxidants and Benzophenone-3 on Desonide Photostability

Desonide is a topical corticoid used in the treatment of skin diseases and is marketed in different pharmaceutical dosage forms. Recently, the poor photostability of a commercially available hair solution after direct exposure to UVA light was verified. In this study, we investigated the ability of the antioxidants ascorbic acid, butylhydroxyanisole (BHA), butylhydroxytoluene (BHT), α-tocopherol, and the UV filter benzophenone-3 (BP-3) to prevent the photodegradation of desonide in hair solution (desonide 0.1%) and the stability of the proposed formulation under environmental conditions. The tested antioxidants were not able to prevent the photolysis of desonide, whereas the addition of 0.3% BP-3 enhanced the photostability of the drug. After 15 h of direct exposure to UVA radiation, the desonide remaining content in the hair solution with BP-3 was approximately 98%. Higher photostability was also verified under UVC radiation. Additionally, the results indicated that the formulation was stable under accelerated and room temperature conditions for 70 days, corresponding to the total period of the study.KEY WORDS: antioxidants, benzophenone-3, desonide, photostability, stability     

Halophilic Archaea Cultivated from Surface Sterilized Middle-Late Eocene Rock Salt Are Polyploid

Live bacteria and archaea have been isolated from several rock salt deposits of up to hundreds of millions of years of age from all around the world. A key factor affecting their longevity is the ability to keep their genomic DNA intact, for which efficient repair mechanisms are needed. Polyploid microbes are known to have an increased resistance towards mutations and DNA damage, and it has been suggested that microbes from deeply buried rock salt would carry several copies of their genomes. Here, cultivable halophilic microbes were isolated from a surface sterilized middle-late Eocene (38–41 million years ago) rock salt sample, drilled from the depth of 800 m at Yunying salt mine, China. Eight unique isolates were obtained, which represented two haloarchaeal genera, Halobacterium and Halolamina. We used real-time PCR to show that our isolates are polyploid, with genome copy numbers of 11–14 genomes per cell in exponential growth phase. The ploidy level was slightly downregulated in stationary growth phase, but the cells still had an average genome copy number of 6–8. The polyploidy of halophilic archaea living in ancient rock salt might be a factor explaining how these organisms are able to overcome the challenge of prolonged survival during their entombment.     

Glutamine synthetase isozymes in germinating barley seeds

Glutamine synthetase (GS; EC 6.3.1.2) is a key enzyme of ammonia assimilation in higher plants. In the present study the subunit composition and localization of GS in germinating barley ( Hordeum vulgare ) seed have been clarified. Analysis of the GS polypeptide composition by immunoblotting revealed two different polypeptides. A and B, with a molecular mass of 42 and 40 kDa, respectively. In the scutellum subunit A was already present in the ungerminated seed and remained unchanged, whereas subunit B appeared on day 2 and increased about 5-fold during germination. Polypeptide B also appeared later during germination in the aleurone layer, roots and weakly in the etiolated shoots. By immunogold microscopy, GS was detected in the scutellum and the aleurone layer of barley seeds during germination. Subcellular localization of GS on ultrathin cryosections showed that a cytosolic isozyme was present in the scutellum. Our study confirms that only a cytosolic GS is expressed in barley seed, and its subunit composition changes during germination.     

Plasticity of leaf traits and insect herbivory in Solanum incanum L. (Solanaceae) in Nguruman, SW Kenya

Plasticity of leaf traits of Solanum incanum was evaluated by comparing its expression in three sites differing in soil moisture (dry, intermediate, humid) in Nguruman, SW Kenya. Leaf size and shape, and leaf traits related to defence against herbivores, varied significantly among sites. The relationship between leaf traits showing among-site variation and insect herbivory was evaluated at a within-site scale. Leaf thickness was correlated with the level of foliar herbivory by a flea beetle ( Epitrix sp.). This correlation was negative at the dry site and positive at the humid site. No relationship was found at the intermediate site. Interestingly, leaf thickness and toughness were positively and significantly correlated at the dry site, but not elsewhere. Finally, overall patterns of herbivory by the flea beetle and unidentified defoliators differed among sites. The importance of scale when evaluating plant plasticity is discussed.     

Subcutaneous Pseudallescheriasis in a renal transplant recipient

This paper reports a case of a single subcutaneous nodule caused byPseudallescheria boydii in a renal transplant recipient, possibly of nontraumatic origin. The patient was treated surgically and with itraconazole.