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91.
Daniela Russo Maria Grazia Ortore Francesco Spinozzi Paolo Mariani Camille Loupiac Burkhard Annighofer Alessandro Paciaroni 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Methods
Combining small-angle X-ray and neutron scattering measurements with inelastic neutron scattering experiments, we investigated the impact of high hydrostatic pressure on the structure and dynamics of β-lactoglobulin (βLG) in aqueous solution.Background
βLG is a relatively small protein, which is predominantly dimeric in physiological conditions, but dissociates to monomer below about pH 3.Results
High-pressure structural results show that the dimer–monomer equilibrium, as well as the protein–protein interactions, are only slightly perturbed by pressure, and βLG unfolding is observed above a threshold value of 3000 bar. In the same range of pressure, dynamical results put in evidence a slowing down of the protein dynamics in the picosecond timescale and a loss of rigidity of the βLG structure. This dynamical behavior can be related to the onset of unfolding processes, probably promoted from water penetration in the hydrophobic cavity.General significance
Results suggest that density and compressibility of water molecules in contact with the protein are key parameters to regulate the protein flexibility. 相似文献92.
93.
Evidence can provide support for or against a particular biogeographical hypothesis. Treating a hypothesis as if it were evidence or an empirical observation confounds many biogeographical analyses. We focus on two recent publications that address, in part, the evolution of the biota of Sulawesi, the large Indonesian island in the centre of the Indo‐Australian Archipelago. Many biogeographical explanations are hampered by invoking simple notions of mechanism or process – dispersal and vicariance – or constraints, such as dispersal from a centre of origin, and, in so doing, dismiss more complex geological phenomena such as emergent volcanoes within island chains or composite areas as irrelevant. Moreover, they do not search for, therefore never discover, biogeographical patterns that may better explain the distribution of biota through time. 相似文献
94.
Olga De Castro Antonietta Di Maio José Armando Lozada García Danilo Piacenti Mario Vázquez-Torres Paolo De Luca 《Annals of botany》2013,112(3):589-602
Background and Aims
Recent research on the history of Platanus reveals that hybridization phenomena occurred in the central American species. This study has two goals: to help resolve the evolutive puzzle of central American Platanus, and to test the potential of real-time polymerase chain reaction (PCR) for detecting ancient hybridization.Methods
Sequencing of a uniparental plastid DNA marker [psbA-trnH(GUG) intergenic spacer] and qualitative and quantitative single nucleotide polymorphism (SNP) genotyping of biparental nuclear ribosomal DNA (nrDNA) markers [LEAFY intron 2 (LFY-i2) and internal transcribed spacer 2 (ITS2)] were used.Key Results
Based on the SNP genotyping results, several Platanus accessions show the presence of hybridization/introgression, including some accessions of P. rzedowskii and of P. mexicana var. interior and one of P. mexicana var. mexicana from Oaxaca (= P. oaxacana). Based on haplotype analyses of the psbA-trnH spacer, five haplotypes were detected. The most common of these is present in taxa belonging to P. orientalis, P. racemosa sensu lato, some accessions of P. occidentalis sensu stricto (s.s.) from Texas, P. occidentalis var. palmeri, P. mexicana s.s. and P. rzedowskii. This is highly relevant to genetic relationships with the haplotypes present in P. occidentalis s.s. and P. mexicana var. interior.Conclusions
Hybridization and introgression events between lineages ancestral to modern central and eastern North American Platanus species occurred. Plastid haplotypes and qualitative and quantitative SNP genotyping provide information critical for understanding the complex history of Mexican Platanus. Compared with the usual molecular techniques of sub-cloning, sequencing and genotyping, real-time PCR assay is a quick and sensitive technique for analysing complex evolutionary patterns. 相似文献95.
Paolo Bianco Roger Barker Oliver Brüstle Elena Cattaneo Hans Clevers George Q Daley Michele De Luca Lawrence Goldstein Olle Lindvall Christine Mummery Clara Sattler de Sousa e Brito Austin Smith 《The EMBO journal》2013,32(11):1489-1495
At the time of writing, the Italian Parliament is debating a new law that would make it legal to practice an unproven stem cell treatment in public hospitals. The treatment, offered by a private non‐medical organization, may not be safe, lacks a rationale, and violates current national laws and European regulations. This case raises multiple concerns, most prominently the urgent need to protect patients who are severely ill, exposed to significant risks, and vulnerable to exploitation. The scientific community must consider the context—social, financial, medical, legal—in which stem cell science is currently situated and the need for stringent regulation. Additional concerns are emerging. These emanate from the novel climate, created within science itself, and stem cell science in particular, by the currently prevailing model of ‘translational medicine’. Only rigorous science and rigorous regulation can ensure translation of science into effective therapies rather than into ineffective market products, and mark, at the same time, the sharp distinction between the striving for new therapies and the deceit of patients. 相似文献
96.
Xiaojing Cong Salvatore Bongarzone Gabriele Giachin Paolo Carloni 《Journal of biomolecular structure & dynamics》2013,31(8):829-840
Mutations in the prion protein (PrP) can cause spontaneous prion diseases in humans (Hu) and animals. In transgenic mice, mutations can determine the susceptibility to the infection of different prion strains. Some of these mutations also show a dominant-negative effect, thus halting the replication process by which wild type mouse (Mo) PrP is converted into Mo scrapie. Using all-atom molecular dynamics (MD) simulations, here we studied the structure of HuPrP, MoPrP, 10?Hu/MoPrP chimeras, and 1 Mo/sheepPrP chimera in explicit solvent. Overall, ~2?μs of MD were collected. Our findings suggest that the interactions between α1 helix and N-terminal of α3 helix are critical in prion propagation, whereas the β2–α2 loop conformation plays a role in the dominant-negative effect. An animated Interactive 3D Complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:4. 相似文献
97.
Donatella Camerino Paul Maurice Conway Samantha Sartori Paolo Campanini Madeleine Estryn‐Béhar Beatrice Isabella Johanna Maria van der Heijden 《Chronobiology international》2013,30(2-3):425-442
Satisfactory work ability is sustained and promoted by good physical and mental health and by favorable working conditions. This study examined whether favorable and rewarding work‐related factors increased the work ability among European nurses. The study sample was drawn from the Nurses' Early Exit Study and consisted of 7,516 nursing staff from seven European countries working in state‐owned and private hospitals. In all, 10.8% were day, 4.2% were permanent night, 20.9% were shift without night shift, and 64.1% were shift workers with night shifts. Participants were administered a composite questionnaire at baseline (Time 0) and 1 yr later (Time 1). The Work Ability Index (WAI) at Time 1 was used as the outcome measure, while work schedule, sleep, rewards (esteem and career), satisfaction with pay, work involvement and motivation, and satisfaction with working hours at Time 0 were included as potential determinants of work ability. Univariate and multivariate analyses were conducted after adjusting for a number of confounders (i.e., country, age, sex, type of employment, family status, and other job opportunities in the same area). Work schedule was not related to Time 1 changes in WAI. Higher sleep quality and quantity and more favorable psychosocial factors significantly increased work ability levels. Higher sleep quality and quantity did not mediate the effect of work schedule on work ability. No relevant interaction effects on work ability were observed between work schedule and the other factors considered at Time 0. As a whole, sleep and satisfaction with working time were gradually reduced from day work to permanent night work. However, scores on work involvement, motivation, and satisfaction with pay and rewards were the highest in permanent night workers and the lowest in rotating shift workers that included night shifts. 相似文献
98.
Paolo Barghini Deborah Moscatelli Anna Maria Vittoria Garzillo Silvia Crognale Massimiliano Fenice 《Enzyme and microbial technology》2013
The Antarctic fungus Lecanicillium muscarium CCFEE-5003 was preliminary cultivated in shaken flasks to check its chitinase production on rough shrimp and crab wastes. Production on shrimp shells was much higher than that on crab shells (104.6 ± 9.3 and 48.6 ± 3.1 U/L, respectively). For possible industrial applications, bioprocess optimization was studied on shrimp shells in bioreactor using RSM to state best conditions of pH and substrate concentration. Optimization improved the production by 137% (243.6 ± 17.3). Two chitinolytic enzymes (CHI1 and CHI2) were purified and characterized. CHI1 (MW ca. 61 kDa) showed optima at pH 5.5 and 45 °C while CHI2 (MW ca. 25 kDa) optima were at pH 4.5 and 40 °C. Both enzymes maintained high activity levels at 5 °C and were inhibited by Fe++, Hg++ and Cu++. CHI2 was strongly allosamidin-sensitive. Both proteins were N-acetyl-hexosaminidases (E.C. 3.2.1.52) but showed different roles in chitin hydrolysis: CHI1 could be defined as “chitobiase” while CHI2 revealed a main “eso-chitinase” activity. 相似文献
99.
Filipe Dantas-Torres Riccardo Paolo Lia Gioia Capelli Domenico Otranto 《Experimental & applied acarology》2013,61(1):119-127
It is acknowledged that data from field studies on tick ecology might be biased by collection methods, but actually comparative studies are still limited. Herein we assessed whether the efficiency of flagging and dragging varies according to tick developmental stage, species, season and habitat. Ticks were collected in three sites bordered by an oak forest. The abundance of ticks collected by each collection method varied according to tick species, developmental stage, season, and habitat. Flagging was in general more efficient in collecting adult ticks, especially in spring and winter. Females were more frequently collected by flagging in the meadow and grassland habitats and males in the man-made trail. Flagging collected significantly more adults of Dermacentor marginatus, Hyalomma marginatum, Haemaphysalis inermis and Ixodes ricinus. Flagging was more efficient in collecting D. marginatus and I. ricinus in spring, and H. inermis and I. ricinus females in both spring and winter. In summer and autumn tick abundances were generally similar, with the exception of D. marginatus female in autumn. Flagging was more efficient in collecting D. marginatus adults in the meadow habitat and in the man-made trail, and I. ricinus adults in the meadow and grassland habitats. Dragging was more efficient in grassland for R. turanicus. Our results suggest that variations in terms of collection method performance are associated to factors linked to tick behaviour, habitat characteristics, and climate. Field studies employing these collection methods should take this into account to avoid misleading conclusions about tick population dynamics and tick-borne pathogen transmission risk. 相似文献
100.