Biology and defensive secretion of myrmecophilous Thiasophila spp. (Coleoptera: Staphylinidae: Aleocharinae) associated with the Formica rufa species group

Various aspects of the biology of the myrmecophilous Thiasophila angulata and T. szujeckii (Staphylinidae; Aleocharinae), mainly associated with the Formica rufa species group, are studied. The composition of defensive gland secretions from adults of T. angulata has been analysed. The complete development (egg-L_1-3-pupa-adult form), including adult overwintering, of both species takes place solely in ant nests. Under laboratory conditions, this lasts for about 22 days in T. angulata, and the period elapsing between the old and new generations of insects is approximately two months. The mean fecundity of adults of this species (28 eggs) was determined, as well as the duration of its reproductive period (mean 28.5 days), and lifespan (mean 67 days). In natural conditions T. angulata, found within nests of Formica polyctena and F. rufa, produces three generations, and the sibling species T. szujeckii one generation per year. These two species differ in their phenologies and abundance dynamics of adults and larvae, which is linked to the size and temperature regime of the host nest. The results of this study uphold the recent separation of T. angulata and T. szujeckii based on morphological features of adults and selected molecular markers. Adults and larvae of T. angulata forage on both live and dead food items accumulated by the host, as well as on the host’s eggs and larvae. Both the beetle larvae and adults remain unmolested among the host workers. The adults use their defensive gland secretions, which contains substantial quantities of toxic quinones, when necessary. According to the current categories of myrmecophiles, T. angulata (and by analogy, T. szujeckii as well) should be classified as a species wholly integrated with the host.     

APJ acts as a dual receptor in cardiac hypertrophy

Cardiac hypertrophy is initiated as an adaptive response to sustained overload but progresses pathologically as heart failure ensues. Here we report that genetic loss of APJ, a G-protein-coupled receptor, confers resistance to chronic pressure overload by markedly reducing myocardial hypertrophy and heart failure. In contrast, mice lacking apelin (the endogenous APJ ligand) remain sensitive, suggesting an apelin-independent function of APJ. Freshly isolated APJ-null cardiomyocytes exhibit an attenuated response to stretch, indicating that APJ is a mechanosensor. Activation of APJ by stretch increases cardiomyocyte cell size and induces molecular markers of hypertrophy. Whereas apelin stimulates APJ to activate Gαi and elicits a protective response, stretch signals in an APJ-dependent, G-protein-independent fashion to induce hypertrophy. Stretch-mediated hypertrophy is prevented by knockdown of β-arrestins or by pharmacological doses of apelin acting through Gαi. Taken together, our data indicate that APJ is a bifunctional receptor for both mechanical stretch and the endogenous peptide apelin. By sensing the balance between these stimuli, APJ occupies a pivotal point linking sustained overload to cardiomyocyte hypertrophy.     

BENEFITS AND COSTS IN SELECTING FUEL FOR MUNICIPALITY HEATING SYSTEMS WITH THE ANALYTIC HIERARCHY PROCESS

1. Introduction Real technical systems are complex in nature. Their complexity arises not only from technology, but also from their multidisciplinary nature. Therefore, to make an effective choice out of a limited, but very different set of available alternatives, a multi-criteria approach is required. To assess the value of existing alternatives there are different methodologies that could be applied e.g. Multi-Attribute Utility Technique (MAUT) (Keeney and Raiffa, 1976), Data Envelopmen…     

兰州盆地第三系磁性地层年代与古环境记录

对兰州盆地永登剖面第三系沉积物进行了磁性地层学研究,建立了古新世～中新世磁性地层序列,并对比ＢＫＳＡ９５古地磁年表为相应地层及所含哺乳动物群建立了时间标尺,讨论了盆地古环境及与青藏高原隆升关系。结果表明：西柳沟组顶界年龄约５１Ｍａ。时代为始新世。野狐城组顶界年龄大约为３１．５Ｍａ底界年龄为５１Ｍａ,时代为早始新世晚期～早渐新世早期。咸水河组顶界年龄大约为１５Ｍａ,底界年龄约为３１．５Ｍａ,时代为早     

Pre-ovipositional and ovipositional behaviour of Lasioseius ometes (Oudemans) and Hypoaspis kargi Costa (Acari: Dermanyssiae: Ascidae,Laelapidae) with notes on egg protection strategies in Mesostigmata

Egg deposition by the soil mites Lasioseius ometes (Oudemans, 1903) and Hypoaspis kargi Costa, 1968 was observed using continuous video-monitoring. The process in both species was found to consist of four distinct phases. In Phase 1, both species engage in pre-ovipositional activity prior to the egg being extruded from the genital opening. In L. ometes, the female often selects a substrate depression for egg laying and examines the depression carefully with the gnathosoma and legs I before oviposition. In H. kargi, egg deposition sites are chosen without regard for substrate depressions. Phase 1 lasted approximately 3 minutes for both species. Phase 2 involved egg extrusion and holding of the egg beneath the gnathosoma. Phase 2 lasted approximately 20 times longer in L. ometes (5 minutes) than in H. kargi. Alteration of the egg surface in the form of thorn-like outgrowths was recorded in L. ometes. Egg deposition occurs in Phase 3, and in L. ometes the egg is generally placed at the deposition site using the chelicerae. Hypoaspis kargi also uses the chelicerae for egg manipulation, but also adjusts orientation of the egg with legs I. The sticky nature of egg surface in H. kargi may provide a means for the female to effectively cover the exposed egg with a protective layer of soil particles. Egg deposition in both species occurred in less than 90 seconds. Phase 4 involves egg covering, but behaviour of the female during this last phase differs markedly between the two species. In L. ometes, the female tends to remain close to the egg, whereas in H. kargi the female moves away from the egg to search for substrate particles appropriate for its covering. The average time for Phase 4 in H. kargi was approximately four times longer (80+ minutes) than in L. ometes.     

De novo mutations in the actin genes ACTB and ACTG1 cause Baraitser-Winter syndrome

Brain malformations are individually rare but collectively common causes of developmental disabilities. Many forms of malformation occur sporadically and are associated with reduced reproductive fitness, pointing to a causative role for de novo mutations. Here, we report a study of Baraitser-Winter syndrome, a well-defined disorder characterized by distinct craniofacial features, ocular colobomata and neuronal migration defect. Using whole-exome sequencing of three proband-parent trios, we identified de novo missense changes in the cytoplasmic actin-encoding genes ACTB and ACTG1 in one and two probands, respectively. Sequencing of both genes in 15 additional affected individuals identified disease-causing mutations in all probands, including two recurrent de novo alterations (ACTB, encoding p.Arg196His, and ACTG1, encoding p.Ser155Phe). Our results confirm that trio-based exome sequencing is a powerful approach to discover genes causing sporadic developmental disorders, emphasize the overlapping roles of cytoplasmic actin proteins in development and suggest that Baraitser-Winter syndrome is the predominant phenotype associated with mutation of these two genes.     

Mitochondrial quality control in AMD: does mitophagy play a pivotal role?

Age-related macular degeneration (AMD) is the predominant cause of visual loss in old people in the developed world, whose incidence is increasing. This disease is caused by the decrease in macular function, due to the degeneration of retinal pigment epithelium (RPE) cells. The aged retina is characterised by increased levels of reactive oxygen species (ROS), impaired autophagy, and DNA damage that are linked to AMD pathogenesis. Mitophagy, a mitochondria-specific type of autophagy, is an essential part of mitochondrial quality control, the collective mechanism responsible for this organelle’s homeostasis. The abundance of ROS, DNA damage, and the excessive energy consumption in the ageing retina all contribute to the degeneration of RPE cells and their mitochondria. We discuss the role of mitophagy in the cell and argue that its impairment may play a role in AMD pathogenesis. Thus, mitophagy as a potential therapeutic target in AMD and other degenerative diseases is as well explored.     

Influence of adrenergic blocking agents upon morphine and catecholamine analgesic effect

Resumen Las catecolaminas adrenalina (0,25 y 0,5 mg/kg) noradrenalina (0,5 y 1 mg/kg) e isoproterenol (4 y 8 mg/kg) producen efecto analgésico significativo en lauchas. También aumentan (adrenalina 0,25 mg/kg, noradrenalina 0,5 mg/kg e isoproterenol 4 mg/kg) el efecto analgésico de pequeñas dosis de morfina (1 mg/kg). El bloqueador -adrenérgico dihidroergotamina (4 mg/kg) no influencia substancialmente estas acciones, pero el bloquente-adrenérgico propranolol (1 mg/kg) bloquea los efectos analgésicos de la morfina, adrenalina e isoproterenol, no siendo tan efectivo contra la noradrenalina. Se deduce que debe existir un compromiso de receptores-adrenérgicos en el mecanismo de los efectos analgésicos de las catecolaminas y también de la morfina.

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Fellow of the Consejo de Investigaciones Cientificas y Técnicas.