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181.
Julien Benoit El Mabrouk Essid Wissem Marzougui Hayet Khayati Ammar Renaud Lebrun Rodolphe Tabuce Laurent Marivaux 《Journal of human evolution》2013
We report the discovery of three isolated primate petrosal fragments from the fossiliferous locality of Chambi (Tunisia), a primate-bearing locality dating from the late early to the early middle Eocene. These fossils display a suite of anatomical characteristics otherwise found only in strepsirhines, and as such might be attributed either to Djebelemur or/and cf. Algeripithecus, the two diminutive stem strepsirhine primates recorded from this locality. Although damaged, the petrosals provide substantial information regarding the ear anatomy of these advanced stem strepsirhines (or pre-tooth-combed primates), notably the patterns of the pathway of the arterial blood supply. Using μCT-scanning techniques and digital segmentation of the structures, we show that the transpromontorial and stapedial branches of the internal carotid artery (ICA) were present (presence of bony tubes), but seemingly too small to supply enough blood to the cranium alone. This suggests that the ICA was not the main cranial blood supply in stem strepsirhines, but that the pharyngeal or vertebral artery primitively ensured a great part of this role instead, an arterial pattern that is reminiscent of modern cheirogaleid, lepilemurid lemuriforms and lorisiforms. This could explain parallel loss of the ICA functionality among these families. Specific measurements made on the cochlea indicate that the small strepsirhine primate(s) from Chambi was (were) highly sensitive to high frequencies and poorly sensitive to low frequencies. Finally, variance from orthogonality of the plane of the semicircular canals (SCs) calculated on one petrosal (CBI-1-569) suggests that Djebelemur or cf. Algeripithecus likely moved (at least its head) in a way similar to that of modern mouse lemurs. 相似文献
182.
Jean-Paul Comet Mathilde Noual Adrien Richard Julio Aracena Laurence Calzone Jacques Demongeot Marcelle Kaufman Aurélien Naldi El Houssine Snoussi Denis Thieffry 《Bulletin of mathematical biology》2013,75(6):906-919
It has been proved, for several classes of continuous and discrete dynamical systems, that the presence of a positive (resp. negative) circuit in the interaction graph of a system is a necessary condition for the presence of multiple stable states (resp. a cyclic attractor). A positive (resp. negative) circuit is said to be functional when it “generates” several stable states (resp. a cyclic attractor). However, there are no definite mathematical frameworks translating the underlying meaning of “generates.” Focusing on Boolean networks, we recall and propose some definitions concerning the notion of functionality along with associated mathematical results. 相似文献
183.
Aurora M. Pat-Espadas Elías Razo-Flores J. Rene Rangel-Mendez Francisco J. Cervantes 《Applied microbiology and biotechnology》2013,97(21):9553-9560
The present study is the first report on the ability of Geobacter sulfurreducens PCA to reduce Pd(II) and produce Pd(0) nano-catalyst, using acetate as electron donor at neutral pH (7.0?±?0.1) and 30 °C. The microbial production of Pd(0) nanoparticles (NPs) was greatly enhanced by the presence of the redox mediator, anthraquinone-2,6-disulfonate (AQDS) when compared with controls lacking AQDS and cell-free controls. A cell dry weight (CDW) concentration of 800 mg/L provided a larger surface area for Pd(0) NPs deposition than a CDW concentration of 400 mg/L. Sample analysis by transmission electron microscopy revealed the formation of extracellular Pd(0) NPs ranging from 5 to 15 nm and X-ray diffraction confirmed the Pd(0) nature of the nano-catalyst produced. The present findings open the possibility for a new alternative to synthesize Pd(0) nano-catalyst and the potential application for microbial metal recovery from metal-containing waste streams. 相似文献
184.
Ahmed Abdelmoniem Mousa Shinuo Cao Gabriel Oluga Aboge Mohamad Alaa Terkawi Ahmed El Kirdasy Akram Salama Mabrouk Attia Mahmoud Aboulaila Mo Zhou Ketsarin Kamyingkird Paul Franck Adjou Moumouni Tatsunori Masatani Sami Ahmed Abd El Aziz Waheed Mohammed Moussa Bayin Chahan Shinya Fukumoto Yoshifumi Nishikawa Salah Sayed El Ballal Xuenan Xuan 《Experimental parasitology》2013
Identification and molecular characterization of Babesia gibsoni proteins with potential antigenic properties are crucial for the development and validation of the serodiagnostic method. In this study, we isolated a cDNA clone encoding a novel B. gibsoni 76-kDa protein by immunoscreening of the parasite cDNA library. Computer analysis revealed that the protein presents a glutamic acid-rich region in the C-terminal. Therefore, the protein was designated as B. gibsoni glutamic acid-rich protein (BgGARP). A BLASTp analysis of a translated BgGARP polypeptide demonstrated that the peptide shared a significant homology with a 200-kDa protein of Babesia bigemina and Babesia bovis. A truncated BgGARP cDNA (BgGARPt) encoding a predicted 13-kDa peptide was expressed in Escherichia coli (E. coli), and mouse antisera against the recombinant protein were used to characterize a corresponding native protein. The antiserum against recombinant BgGARPt (rBgGARPt) recognized a 140-kDa protein in the lysate of infected erythrocytes, which was detectable in the cytoplasm of the parasites by confocal microscopic observation. In addition, the specificity and sensitivity of enzyme-linked immunosorbent assay (ELISA) with rBgGARPt were evaluated using B. gibsoni-infected dog sera and specific pathogen-free (SPF) dog sera. Moreover, 107 serum samples from dogs clinically diagnosed with babesiosis were examined using ELISA with rBgGARPt. The results showed that 86 (80.4%) samples were positive by rBgGARPt-ELISA, which was comparable to IFAT and PCR as reference test. Taken together, these results demonstrate that BgGARP is a suitable serodiagnostic antigen for detecting antibodies against B. gibsoni in dogs. 相似文献
185.
Kamal Guerrouj Eduardo Pérez-Valera Rajaa Chahboune Hanaa Abdelmoumen Eulogio J. Bedmar Mustapha Missbah El Idrissi 《Antonie van Leeuwenhoek》2013,104(2):187-198
Astragalus gombiformis is a desert symbiotic nitrogen-fixing legume of great nutritional value as fodder for camels and goats. However, there are no data published on the rhizobial bacteria that nodulate this wild legume in northern Africa. Thirty-four rhizobial bacteria were isolated from root nodules of A. gombifomis grown in sandy soils of the South-Eastern of Morocco. Twenty-five isolates were able to renodulate their original host and possessed a nodC gene copy. The phenotypic and genotypic characterizations carried out illustrated the diversity of the isolates. Phenotypic analysis showed that isolates used a great number of carbohydrates as sole carbon source. However, although they were isolated from arid sandy soils, the isolates do not tolerate drought stress applied in vitro. The phenotypic diversity corresponded mainly to the diversity in the use of some carbohydrates. The genetic analysis as assessed by repetitive extragenic palindromic (REP)-polymerase chain reaction (PCR) showed that the isolates clustered into 3 groups at a similarity coefficient of 81 %. The nearly-complete 16S rRNA gene sequence from a representative strain of each PCR-group showed they were closely related to members of the genus Mesorhizobium of the family Phyllobactericeae within the Alphaproteobacteria. Sequencing of the housekeeping genes atpD, glnII and recA, and their concatenated phylogenetic analysis, showed they are closely related to Mesorhizobium camelthorni. Sequencing of the symbiotic nodC gene from each strain revealed they had 83.53 % identity with the nodC sequence of the type strain M. camelthorni CCNWXJ 40-4T. 相似文献
186.
Erick Francisco Rakotoniriana Mamy Rafamantanana Denis Randriamampionona Christian Rabemanantsoa Suzanne Urveg-Ratsimamanga Mondher El Jaziri Françoise Munaut Anne-Marie Corbisier Joëlle Quetin-Leclercq Stéphane Declerck 《Antonie van Leeuwenhoek》2013,103(1):121-133
Thirty-one endophytic bacteria isolated from healthy leaves of Centella asiatica were screened in vitro for their ability to reduce the growth rate and disease incidence of Colletotrichum higginsianum, a causal agent of anthracnose. Isolates of Cohnella sp., Paenibacillus sp. and Pantoea sp. significantly stimulated the growth rate of C. higginsianum MUCL 44942, while isolates of Achromobacter sp., Acinetobacter sp., Microbacterium sp., Klebsiella sp. and Pseudomonas putida had no influence on this plant pathogen. By contrast, Bacillus subtilis BCA31 and Pseudomonas fluorescens BCA08 caused a marked inhibition of C. higginsianum MUCL 44942 growth by 46 and 82 %, respectively. Cell-free culture filtrates of B. subtilis BCA31 and P. fluorescens BCA08 were found to contain antifungal compounds against C. higginsianum MUCL 44942. Inoculation assays on in vitro-cultured plants of C. asiatica showed that foliar application of B. subtilis BCA31, three days before inoculation with C. higginsianum MUCL 44942, significantly reduced incidence and severity of the disease. The role of endophytic bacteria in maintaining the apparent inactivity of C. higginsianum MUCL 44942 in C. asiatica grown in the wild is discussed. 相似文献
187.
Magali Deleu Joseph Lorent Laurence Lins Robert Brasseur Nathalie Braun Karim El Kirat Tommy Nylander Yves F. Dufrêne Marie- Paule Mingeot-Leclercq 《生物化学与生物物理学报:生物膜》2013,1828(2):801-815
Surfactin, a bacterial amphiphilic lipopeptide is attracting more and more attention in view of its bioactive properties which are in relation with its ability to interact with lipids of biological membranes. In this work, we investigated the effect of surfactin on membrane structure using model of membranes, vesicles as well as supported bilayers, presenting coexistence of fluid-disordered (DOPC) and gel (DPPC) phases. A range of complementary methods was used including AFM, ellipsometry, dynamic light scattering, fluorescence measurements of Laurdan, DPH, calcein release, and octadecylrhodamine B dequenching. Our findings demonstrated that surfactin concentration is critical for its effect on the membrane. The results suggest that the presence of rigid domains can play an essential role in the first step of surfactin insertion and that surfactin interacts both with the membrane polar heads and the acyl chain region. A mechanism for the surfactin lipid membrane interaction, consisting of three sequential structural and morphological changes, is proposed. At concentrations below the CMC, surfactin inserted at the boundary between gel and fluid lipid domains, inhibited phase separation and stiffened the bilayer without global morphological change of liposomes. At concentrations close to CMC, surfactin solubilized the fluid phospholipid phase and increased order in the remainder of the lipid bilayer. At higher surfactin concentrations, both the fluid and the rigid bilayer structures were dissolved into mixed micelles and other structures presenting a wide size distribution. 相似文献
188.
Małgorzata Proćków Magda Drvotová Lucie Juřičková Elżbieta Kuźnik-Kowalska 《Biologia》2013,68(1):131-141
For the first time the life cycle of the common land snail Trochulus hispidus was completely described in Central Europe (Poland). This is a semelparous species predominantly with an annual life cycle and the reproductive period lasting from April till October. The first young snails hatch in spring, grow rapidly in summer and reach ca. 4 whorls until winter. In spring of the next year they mature and reproduce. After that they die. There is hardly any growth from late autumn till early spring. The average proportional growth rate is ca. 0.3 whorl/month in the wild. The fastest growth is present in the youngest snails and then gradually decreases over the course of their age. Laboratory and field observations allowed for establishing the following life cycle parameters: eggs calcified, almost spherical, ca. 1.5 mm, laid in spring and summer in batches of between 1 and 47. Time to hatching is 6–24 days, hatching is asynchronous; newly-hatched snails have approximately 1.5 whorls. Analysis of food preferences revealed, that T. hispidus tends to restrict its diet during the life. Generally the youngest snails equally consumed leaves of all four tree species offered (Fraxinus excelsior, Acer pseudoplatanus, Tilia cordata and A. platanoides) whereas adults preferred F. excelsior over A. pseudoplatanus and A. platanoides. 相似文献
189.
Elżbieta Dumnicka Joanna Galas Igor Jatulewicz Joanna Karlikowska Bartłomiej Rzonca 《Biologia》2013,68(1):142-149
Spatial patterns in macroinvertebrate communities and some abiotic factors were examined in three rheocrene springs and their springbrooks (Kraków-Cz?stochowa Upland, southern Poland). The mean discharge of particular springs ranged from 5 to 11 L s?1, and its annual fluctuations were small. Water temperature was very stable at all sampling sites. In the eucrenon the number of benthic taxa was the smallest (9–14 determined to the family level), but the densities were the highest (approx. 14000 ind. m?2). The biggest changes in macroinvertebrate composition were observed in the modified hypocrenon, which is an artificial pond. The lowest number of taxa were found in a natural, short springbrook with a nondiversified bottom substrate. The density of crenophilic taxa (Drusus trifidus, Dugesia gonocephala, Elmidae) diminished along the springbrooks, while the opposite trend was observed for ubiquitous taxa (some Oligochaeta, Asellus aquaticus and Chironomidae). Even in a very short natural springbrook (30 m), Drusus trifidus, the only species of Trichoptera found in the springs discussed here, goes through the entire development cycle. The strongest influence of a big river was observed at the outflow of one of the natural springbrooks, where the highest number of riverine oligochaete species were found. The benthic fauna of the springs studied here differed from that found in other springs in this area — the absence of the typical crenophilic species Bithynella austriaca (Gastropoda) and the presence of Gianus aquedulcis (Oligochaeta) may indicate the autonomy of the spring fauna in the Mstów area, possibly resulting from the postglacial geomorphological formation of this region or differences in habitat conditions. 相似文献
190.
Small algae are the trophic basis in both marine and freshwater ecosystems. The identification of tiny microorganisms and place of their origin is laborious but necessary. This paper consists of a literature review of 17 species of planktonic algae, with a discussion of taxonomic problems. We also clarify whether these 17 species are non-native, invasive or cryptogenic species, with an indication whether they had been recognised as ‘alien’ in Europe. According to our observations, areas colonized by small and alien algal species, were anthropogenically altered. There were: systems with heated waters (‘heated islands’), which imitated tropical conditions; highly eutrophic to hypereutrophic water ecosystems, easily colonized by alien species, fishponds with intense fish cultivation, where alien species of fish are/had been introduced, which carried also other alien organisms; and inland water ecosystems with high salinity or high conductivity e.g. pits inundated by mine waters, imitating sea or brackish conditions acting as hubs of migration of alien species adapted to brackish or saline waters. We have prepared a map showing areas inhabited by alien species, both of documented places and hypothetical ones, where we would expect alien species to occur. 相似文献