Reproductive biology of two species of Hyalella Smith, 1874 (Crustacea: Amphipoda: Hyalellidae) from southern Brazil

Reproduction is a critical event in the life cycle of animals, and a high amount of energy is allocated to it. The aim of this study was to characterize the reproductive biology of two recently described species of Hyalella from the north-east region of state of Rio Grande do Sul in southern Brazil. The specimens were collected during 12 months from a stream source (Hyalella georginae) and from a water reservoir (H. gauchensis), in Palmeira das Missões municipality, state of Rio Grande do Sul. Upon sampling, ovigerous females and pairs in precopulatory behaviour were separated into microtubes. In the laboratory, the cephalothorax length (CL in mm) of all specimens was measured. Male size at onset of sexual maturity was larger than that of the females, in both species. There was a correlation between the size of paired males and females: larger males carried larger females, in both Hyalella species. Precopulatory pairs were found throughout the year; however, H. georginae had a higher frequency in spring, and H. gauchensis in autumn. There was a positive correlation between the CL of ovigerous females and the number of eggs/juveniles. A reduction in the number of eggs throughout the embryonic development was observed in H. georginae. The average fecundity of H. georginae was significantly higher than H. gauchensis. The differences between the reproductive biology of these species may be related to the physical and environmental conditions at which they are exposed in their habitats.     

Orchid bees (Apidae: Euglossini) in Cerrado remnants in northeast Brazil

There is a general lack of information concerning the diversity of bees belonging to the Euglossini tribe in Cerrado areas closest to the Brazilian Amazon. The state of Maranhão is situated in the northeast Brazilian Cerrado and has become the agricultural frontier of the country due to the advancement of monoculture and cattle farming. These activities have suppressed animal and plant populations in large areas of the Cerrado remnants, for which we have not yet obtained adequate scientific knowledge of local species. The objective of this study was to conduct a survey of Euglossini fauna in the northeast Cerrado. We evaluated the variation in species richness, composition and abundance between two distinct vegetation types: Cerrado sensu stricto (s.s.) and gallery forest. Male bees were captured from 7:00 a.m. to 5:00 p.m. over two consecutive days. Captures were carried out once per month from July 2012 to December 2013, using a combination of passive and active collection techniques, including baited traps, as well as a collector with an entomological net to collect bees near traps. We collected a total of 766 Euglossini males belonging to 24 species and five genera. The most abundant species were Eulaema bombiformis, Eulaema nigrita and Eulaema cingulata for the gallery forest site, whereas Eulaema nigrita, Euglossa melanotricha and Euglossa cordata were more abundant in the Cerrado s.s. The gallery forest yielded a higher number of male Euglossini (n = 503, 21 species) compared with the Cerrado s.s. (n = 263, 16 species). The presence of seven exclusive species in the gallery forest and three in the Cerrado s.s. indicated that both environments are important for the maintenance of Euglossini species in this region and highlight the increasing need for conservation programmes for the protection of Cerrado environments.     

Breeding biology of the Sayaca Tanager (Thraupis sayaca) in southeast Brazil

ABSTRACT

Thraupis is a genus of the American endemic Thraupidae (subfamily Thraupinae), comprising seven species that inhabit tropical forests to urban centres. The Sayaca Tanager (Thraupis sayaca) is a disturbance-tolerant species of high representativeness in plant-frugivore networks, but information on its breeding biology is scarce and often restricted to non-systematic surveys. We studied the breeding biology of the T. sayaca, following 39 active nests in a periurban area of southeast Brazil during two breeding seasons (2017/2018, 2018/2019). The breeding season ranged from early September to middle December, and the nests were placed in native and exotic plants and human buildings (nest height above ground: 3.35 ± 1.73 m, mean ± SD). Only females incubated and brooded, but both adults built the nests, fed the nestlings, and removed their faecal sacs. Clutch size was 2.86 ± 0.38 eggs and nest attentiveness was 71.2%. The incubation and nestling periods were, respectively, 13.4 and 17.4 days. Males and females did not differ on nestling provisioning and nest sanitation rates. Nestling provisioning (13.35 ± 6.25 trips/hour) increased with nestling age, while mean brooding time was 37.2% and decreased with nestling age. Apparent nest success was 38.7%, and nest survival according to the Mayfield method was 27.2%. Five nests (20.8%) were parasitised by the Shiny cowbird (Molothrus bonariensis), and we recorded five events of nest-site reuse. We concluded that the most remarkable breeding traits of T. sayaca in comparison with close-related tanagers are the use of anthropogenic nest sites, the higher clutch size and number of feeding trips, and the longer nestling period.     

Heterospecific mating between distantly related species of stink bugs and its evolutionary implications

The copulatory process in animals is preceded by a series of integrated communication processes which are often under selection to guarantee species-specific courtship and copula. However, individuals of species supposedly in reproductive isolation frequently copulate in nature, which has sparked the attention of evolutionary biologists for decades. While studies on this topic have strongly focused on recently diverged species or populations, few instances of heterospecific copula between distantly related species are known. Here we report an intriguing case of interspecific copula between two distantly related species of stink bugs in nature. We replicated this observation in laboratory conditions and revealed an asymmetric relation: males of Chinavia obstinata copulated with females of C. erythrocnemis but the reverse combination did not occur. We propose a series of hypotheses to explain our observations in the light of the current knowledge on mate recognition and reproductive isolation in stink bugs, considering the potential pre- and postcopulatory barriers involved. Once these two species have probably evolved in allopatry and contacted secondarily, the absence of directional selection against mating signals differentiation is a probable process. We argue that similarities in genital shape and size, most likely a result of convergent evolution, may have played a fundamental role in guaranteeing that these species achieved proper coupling.     

Filamentous bodies in human glomerulonephritis

Filamentous bodies have been identified in the glomerular cells of human kidney biopsies. These structures have a close morphological resemblance to ciliary rootlets, although the cells of the glomerular tuft only occasionally bear cilia. Their significance could be, as for cilia, of a cellular disdifferentiation of a pathological cellular proliferation.     

Identification of Megaselia scalaris (Loew, 1866) (Diptera: Phoridae) in mummified human body from Itacambira (MG), Brazil,using scanning electron microscopy and cuticular hydrocarbons

Insect puparia were found adhered to the ribs and other tissues in the abdominal cavity of a natural male mummy found in Itacambira (State of Minas Gerais, Brazil) dating to the Colonial Period. They were collected for identification by scanning electron microscopy, and for comparison of several morphological features with those described in the literature. The puparia were found open and dorsoventrally flattened, making it difficult to visualize the dorsal projections. The tegument is covered by tapered spines and contains rows of small tubercles on the dorsal and lateral regions of the puparium. The posterior spiracle consists of four parallel openings arranged in pairs. These results are indicative that the specimens belong to the species Megaselia scalaris (Loew, 1866) (Diptera: Phoridae). Additionally, cuticular hydrocarbons of the puparia were analysed by gas chromatography coupled to mass spectrometry and compared with the profile of M. scalaris reared in the laboratory.     

世界各国巨型机发展概况

以全球前500台超级计算机(TOP500)评选结果为依据，简述了世界各国巨型机的发展概况，以及我国在巨型计算机发展方面与发达国家的差距。     

生物电脑的最新进展

评述了半导体芯片计算机的致命弱点，综述了生物电脑的基本工作原理、应用前景以及最新进展。     

Participative Methodology for Local Development: The Contribution of Engineers Without Borders from Italy and Colombia: Towards the Improvement of Water Quality in Vulnerable Communities

This paper presents a systemic methodology by which engineering is put to use in vulnerable communities through applied technological research and the main results of its application. The methodology presented corresponds to one implemented and designed by two groups of Engineers without Borders in Europe and Latin America, to integrate technical know-how with local context in communities with water problems in Colombia and the Democratic Republic of Congo. The main results of this methodology are related to the improvement of the living conditions of vulnerable groups thanks to the integration of the communities?? knowledge with engineering know-how, leading to autonomous communities and engineering professors and students learning from real life problems to enrich applied sciences.