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Nádia Caldato Luiz Carlos Forti Ana Paula Protti de Andrade Juliane Floriano Santos Lopes 《Journal of Natural History》2016,50(25-26):1561-1581
Acromyrmex balzani is a grass-cutting ant species frequently found in Cerrado areas. However, little is known about the architecture of the polydomous nests of this ant. Fifteen A. balzani nests located in a cerrado region in Botucatu, São Paulo, Brazil, were studied. The polydomous nests were studied in three ways. First, we investigated the architecture in nests moulded with cement and without moulding. Second, we performed an aggressiveness test among workers in different subnests and nests. Third, we excavated the nest and collected the colony to measure the population, verifying the existence or not of a queen in all nests. A cement mould was made of seven nests to permit better visualization of internal structures such as chambers and tunnels. Eight nests were excavated without moulding and white neutral talc was used to highlight the parts of the nests. After excavation, the depth and dimensions (length, width and height) of the chambers were measured. The results showed that the nests had a single entrance hole whose structure consisted of straw and other plant residues in winter. Mounds of loose soil, if present, were found 6–48 cm from the hole. The number of chambers containing fungus ranged from one to five, with the first being found a few centimetres beneath the ground surface (4 cm) and the last up to a maximum depth of 160 cm. The length of the tunnels ranged from 12 to 28 cm. These tunnels were built in a vertical or inclined position, leading to the chambers. No waste chambers were found, with the waste being deposited externally. Additionally, the polydomous nests contained one to eight subnests. In the aggressiveness test, when concolonial workers were confronted, no aggressiveness was observed. In contrast, when allocolonial workers were confronted, there was a high incidence of aggression among them. Excavation of polydomous nests showed only one queen for each polydomous nest, i.e. subnests with a single queen. Our study contributes to a better understanding of the so far unknown nest architecture of the polydomous grass-cutting ant A. balzani. 相似文献
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Dalila de Fátima Ferreira Leonardo Esteves Lopes 《Journal of Natural History》2017,51(23-24):1425-1435
The Lined Seedeater (Sporophila lineola) is a migratory species that inhabits a variety of open habitats in South America. We studied the breeding biology and territorial behaviour of a colour-banded population of the species in the Universidade Federal de Viçosa, Campus Florestal (1–19,8808ºS, –44,4136ºW), during two breeding seasons (2014/2015 and 2015/2016), which spans from December to April. We monitored 74 nests of this species. The nest is a low cup supported between a fork. Nests are mainly built with grass stems and rootlets, with spider-web used to hold the material together and to bind the nest to its supporting plant. Females are solely responsible for nest building and incubation, which is synchronic, and also for feeding nestlings to a large extent. Males are responsible for defending the territory, which corresponds to a small portion of the home range restricted to the nest environs, and also feed the nestlings. Mean clutch size is two eggs (78% of nests monitored), with clutches of three (20.3%) and four (1.7%) eggs also observed. Eggs are whitish, covered with dark brown blotches and spots to a variable extent. Mean incubation period, considered as the period between the onset of incubation and hatching of the first egg, is 11 days. Nestling period, considered as the period between hatching of the first egg and fledging of the last young, is 10 days. During the first breeding season, the simple percentage of successful nests was 34.1%, while the Mayfield success was 29.8%, with slightly higher values observed during the second breeding season, with 39.4% and 35.7%, respectively. We recorded, for the first time, three cases of polygamy in the species. We also recorded breeding site fidelity for the first time in the species, with males returning to the same territory owned in a previous breeding season. 相似文献
3.
Glaucia N. M. Hajj Camila P. Arantes Marcos Vinicios Salles Dias Martín Roffé Bruno Costa-Silva Marilene H. Lopes Isabel Porto-Carreiro Tatiana Rabachini Flávia R. Lima Flávio H. Beraldo Marco M. A. Prado Rafael Linden Vilma R. Martins 《Cellular and molecular life sciences : CMLS》2013,70(17):3211-3227
The co-chaperone stress-inducible protein 1 (STI1) is released by astrocytes, and has important neurotrophic properties upon binding to prion protein (PrPC). However, STI1 lacks a signal peptide and pharmacological approaches pointed that it does not follow a classical secretion mechanism. Ultracentrifugation, size exclusion chromatography, electron microscopy, vesicle labeling, and particle tracking analysis were used to identify three major types of extracellular vesicles (EVs) released from astrocytes with sizes ranging from 20–50, 100–200, and 300–400 nm. These EVs carry STI1 and present many exosomal markers, even though only a subpopulation had the typical exosomal morphology. The only protein, from those evaluated here, present exclusively in vesicles that have exosomal morphology was PrPC. STI1 partially co-localized with Rab5 and Rab7 in endosomal compartments, and a dominant-negative for vacuolar protein sorting 4A (VPS4A), required for formation of multivesicular bodies (MVBs), impaired EV and STI1 release. Flow cytometry and PK digestion demonstrated that STI1 localized to the outer leaflet of EVs, and its association with EVs greatly increased STI1 activity upon PrPC-dependent neuronal signaling. These results indicate that astrocytes secrete a diverse population of EVs derived from MVBs that contain STI1 and suggest that the interaction between EVs and neuronal surface components enhances STI1–PrPC signaling. 相似文献
4.
TGF-beta-induced Foxp3 inhibits T(H)17 cell differentiation by antagonizing RORgammat function 总被引:2,自引:0,他引:2
Zhou L Lopes JE Chong MM Ivanov II Min R Victora GD Shen Y Du J Rubtsov YP Rudensky AY Ziegler SF Littman DR 《Nature》2008,453(7192):236-240
5.
The distillation and volatility of ionic liquids 总被引:2,自引:0,他引:2
Earle MJ Esperança JM Gilea MA Lopes JN Rebelo LP Magee JW Seddon KR Widegren JA 《Nature》2006,439(7078):831-834
It is widely believed that a defining characteristic of ionic liquids (or low-temperature molten salts) is that they exert no measurable vapour pressure, and hence cannot be distilled. Here we demonstrate that this is unfounded, and that many ionic liquids can be distilled at low pressure without decomposition. Ionic liquids represent matter solely composed of ions, and so are perceived as non-volatile substances. During the last decade, interest in the field of ionic liquids has burgeoned, producing a wealth of intellectual and technological challenges and opportunities for the production of new chemical and extractive processes, fuel cells and batteries, and new composite materials. Much of this potential is underpinned by their presumed involatility. This characteristic, however, can severely restrict the attainability of high purity levels for ionic liquids (when they contain poorly volatile components) in recycling schemes, as well as excluding their use in gas-phase processes. We anticipate that our demonstration that some selected families of commonly used aprotic ionic liquids can be distilled at 200-300 degrees C and low pressure, with concomitant recovery of significant amounts of pure substance, will permit these currently excluded applications to be realized. 相似文献
6.
S. A. Catanzaro-Guimarães N. Alle E. S. Lopes 《Cellular and molecular life sciences : CMLS》1971,27(12):1400-1401
Résumé Utilisant la méthode cytophotométrique on a observé l'accroissement du glycogène et la réduction de ARN dans le foie de souris soumises au traitement toxique par l'uréthane. 相似文献
7.
The lakes of Titan 总被引:1,自引:0,他引:1
Stofan ER Elachi C Lunine JI Lorenz RD Stiles B Mitchell KL Ostro S Soderblom L Wood C Zebker H Wall S Janssen M Kirk R Lopes R Paganelli F Radebaugh J Wye L Anderson Y Allison M Boehmer R Callahan P Encrenaz P Flamini E Francescetti G Gim Y Hamilton G Hensley S Johnson WT Kelleher K Muhleman D Paillou P Picardi G Posa F Roth L Seu R Shaffer S Vetrella S West R 《Nature》2007,445(7123):61-64
The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table. 相似文献
8.
Tatiane Archanjo de Sales Erik Daemon Juliane Floriano Santos Lopes 《Journal of Natural History》2016,50(15-16):971-974
This study aimed to identify the feeding habit of Pheidole radoszkowskii Mayr on Rattus norvegicus (Berkenhout) carcasses, as well as whether its presence limits the occurrence of flies. Pheidole radoszkowskii exhibited more necrophagous than predatory behaviour. Its abundance was inversely proportional to that of flies, confirming that this ant species may cause lesions in carcasses and its presence limits the occurrence of flies. This work clarifies the behaviour of an ant species often encountered on carcasses. 相似文献
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