484 research outputs found

    The cultivation of Castanea sativa (Mill.) in Europe, from its origin to its diffusion on a continental scale

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    The history of Castanea sativa (sweet chestnut) cultivation since medieval times has been well described on the basis of the very rich documentation available. Far fewer attempts have been made to give a historical synthesis of the events that led to the cultivation of sweet chestnut in much earlier times. In this article we attempt to reconstruct this part of the European history of chestnut cultivation and its early diffusion by use of different sources of information, such as pollen studies, archaeology, history and literature. Using this multidisciplinary approach, we have tried to identify the roles of the Greek and Roman civilizations in the dissemination of chestnut cultivation on a European scale. In particular, we show that use of the chestnut for food was not the primary driving force behind the introduction of the tree into Europe by the Romans. Apart from the Insubrian Region in the north of the Italian peninsula, no other centre of chestnut cultivation existed in Europe during the Roman period. The Romans may have introduced the idea of systematically cultivating and using chestnut. In certain cases they introduced the species itself; however no evidence of systematic planting of chestnut exists. The greatest interest in the management of chestnut for fruit production most probably developed after the Roman period and can be associated with the socio-economic structures of medieval times. It was then that self-sufficient cultures based on the cultivation of chestnut as a source of subsistence were forme

    Electron-spin-resonance And Lattice-parameter Study Of Cerium Cubic Laves-phase Compounds: Evidence For Intermediate-valence State

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    A lattice-constant study of the cubic C 15 Ce(IrxOs1-x)2 and Ce(PtxIr1-x)2 mixtures at room temperature reveals anomalous lattice constant versus x behavior. Also the electron-spin-resonance thermal broadening and g shift of Nd3+ in these compounds are anomalous but could be correlated with the lattice parameters. This is taken as evidence for intermediate-valence state in some of the mixtures. © 1980 The American Physical Society.45241966197

    Differences in the Volatile Profile of Apple Cider Fermented with Schizosaccharomyces pombe and Schizosaccharomyces japonicus

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    In this study, two strains of Schizosaccharomyces pombe (NCAIM Y01474(T) and SBPS) and two strains of Schizosaccharomyces japonicus (DBVPG 6274(T), M23B) were investigated for their capacity to ferment apple juice and influence the volatile compounds of cider compared to Saccharomyces cerevisiae EC1118. The ethanol tolerance and deacidification capacity of Schizosaccharomyces yeasts could make them potential substitutes for the commonly used S. cerevisiae starter cultures. Despite different time courses (10-30 d), all strains could complete the fermentation process, and Schizosaccharomyces strains reduced the concentration of malic acid in the apple juice. Results indicated that each yeast exerted a distinctive impact on the volatile profile of the apple cider, giving final products separated using a principal component analysis. The volatile composition of the cider exhibited significant differences in the concentration of alcohols, esters, and fatty acids. Particularly, the flocculant strain S. japonicus M23B increased the levels of ethyl acetate (315.44 +/- 73.07 mg/L), isoamyl acetate (5.99 +/- 0.13 mg/L), and isoamyl alcohol (24.77 +/- 15.19 mg/L), while DBVPG 6274(T) incremented the levels of phenyl ethyl alcohol and methionol up to 6.19 +/- 0.51 mg/L and 3.72 +/- 0.71 mg/L, respectively. A large production of terpenes and ethyl esters (e.g., ethyl octanoate) was detected in the cider fermented by S. cerevisiae EC1118. This study demonstrates, for the first time, the possible application of S. japonicus in cider-making to provide products with distinctive aromatic notes"

    Design of ideal vibrational signals for stinkbug male attraction through vibrotaxis experiments

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    Many groups of insects utilize substrate-borne vibrations for intraspecific communication. This characteristic makes them a suitable model for exploring the vibrations as a tool for pest control in alternative to chemicals. The detailed knowledge of the species communication is a prerequisite to select the best signals to use. In this sense, this study aimed at exploring the use of substrate-borne vibrations for pest control of the brown marmorated stink bug (BMSB), Halyomorpha halys StĂĄl (Heteroptera: Pentatomidae). To this purpose, in a first set of experiments, we identified the spectral and temporal characteristics that best elicit male responsiveness. Bioassays were conducted with artificial signals that mimicked the natural female calling signal. In a second part, we used the acquired knowledge to synthesize new signals endowed with different degrees of attractiveness in single and two choice bioassays using a wooden custom-made T stand

    Combined pangenomics and transcriptomics reveals core and redundant virulence processes in a rapidly evolving fungal plant pathogen

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    Background Studying genomic variation in rapidly evolving pathogens potentially enables identification of genes supporting their “core biology”, being present, functional and expressed by all strains or “flexible biology”, varying between strains. Genes supporting flexible biology may be considered to be “accessory”, whilst the “core” gene set is likely to be important for common features of a pathogen species biology, including virulence on all host genotypes. The wheat-pathogenic fungus Zymoseptoria tritici represents one of the most rapidly evolving threats to global food security and was the focus of this study. Results We constructed a pangenome of 18 European field isolates, with 12 also subjected to RNAseq transcription profiling during infection. Combining this data, we predicted a “core” gene set comprising 9807 sequences which were; (1) present in all isolates; (2) lacking inactivating polymorphisms; and (3) expressed by all isolates. A large accessory genome, consisting of 45% of the total genes was also defined. We classified genetic and genomic polymorphism at both chromosomal and individual gene scales. Proteins required for essential functions including virulence, had lower-than average sequence variability amongst core genes. Both core and accessory genomes encoded many small, secreted candidate effector proteins that likely interact with plant immunity. Viral vector-mediated transient in planta overexpression of 88 candidates failed to identify any which induced leaf necrosis characteristic of disease. However, functional complementation of a non-pathogenic deletion mutant lacking five core genes, demonstrated that full virulence was restored by re-introduction of the single gene exhibiting least sequence polymorphism and highest expression. Conclusions These data support the combined use of pangenomics and transcriptomics for defining genes which represent core, and potentially exploitable, weaknesses in rapidly evolving pathogens

    Do red deer stags (Cervus elaphus) use roar fundamental frequency (F0) to assess rivals?

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    It is well established that in humans, male voices are disproportionately lower pitched than female voices, and recent studies suggest that this dimorphism in fundamental frequency (F0) results from both intrasexual (male competition) and intersexual (female mate choice) selection for lower pitched voices in men. However, comparative investigations indicate that sexual dimorphism in F0 is not universal in terrestrial mammals. In the highly polygynous and sexually dimorphic Scottish red deer Cervus elaphus scoticus, more successful males give sexually-selected calls (roars) with higher minimum F0s, suggesting that high, rather than low F0s advertise quality in this subspecies. While playback experiments demonstrated that oestrous females prefer higher pitched roars, the potential role of roar F0 in male competition remains untested. Here we examined the response of rutting red deer stags to playbacks of re-synthesized male roars with different median F0s. Our results show that stags’ responses (latencies and durations of attention, vocal and approach responses) were not affected by the F0 of the roar. This suggests that intrasexual selection is unlikely to strongly influence the evolution of roar F0 in Scottish red deer stags, and illustrates how the F0 of terrestrial mammal vocal sexual signals may be subject to different selection pressures across species. Further investigations on species characterized by different F0 profiles are needed to provide a comparative background for evolutionary interpretations of sex differences in mammalian vocalizations

    Comparative transcriptomic analyses of Zymoseptoria tritici strains show complex lifestyle transitions and intraspecific variability in transcription profiles

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    Zymoseptoria tritici causes Septoria tritici blotch (STB) on wheat. The disease interaction is characterized by clearly defined temporal phases of infection, ultimately resulting in the death of host tissue. Zymoseptoria tritici is a highly polymorphic species with significant intraspecific variation in virulence profiles. We generated a deep transcriptomic sequencing dataset spanning the entire time course of an infection using a previously uncharacterized, highly virulent Z. tritici strain isolated from a Swiss wheat field. We found that seven clusters of gene transcription profiles explained the progression of the infection. The earliest highly up-regulated genes included chloroperoxidases, which may help the fungus cope with plant defences. The onset of necrotrophy was characterized by a concerted up-regulation of proteases, plant cell wall-degrading enzymes and lipases. Functions related to nutrition and growth characterized late necrotrophy and the transition to saprotrophic growth on dead plant tissue. We found that the peak up-regulation of genes essential for mating coincided with the necrotrophic phase. We performed an intraspecies comparative transcriptomics analysis using a comparable time course infection experiment of the genome reference isolate IPO323. Major components of the fungal infection transcriptome were conserved between the two strains. However, individual small, secreted proteins, proteases and cell wall-degrading enzymes showed strongly differentiated transcriptional profiles between isolates. Our analyses illustrate that successful STB infections involve complex transcriptomic remodelling to up-regulate distinct gene functions. Heterogeneity in transcriptomes among isolates may explain some of the considerable variation in virulence and host specialization found within the species

    Raman-scattering and weak-ferromagnetism studies in Eu2CuO4

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    We show that there is a subtle instability of the T' structure for the R(2)CuO(4) (R = rare earth) compounds at the center of the R series with the boundary at Eu2CuO4. Crystals grown in Pt crucibles and PbQ flux show weak ferromagnetism (WF) and two strongly temperature-dependent forbidden Raman peaks. However crystals grown in alumina crucibles and CuO flux do not show WF and the forbidden Raman peaks are much less intense. The observation of WF and forbidden Raman peaks for Eu2CuO4 compounds suggests that the instability of the T' structure may be associated with O(1) displacement in the CuO2 planes.53283784

    Mortality in Hepatitis C Virus–Infected Patients With a Diagnosis of AIDS in the Era of Combination Antiretroviral Therapy

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    Chronic hepatitis C increased mortality by approximately 50% in patients with Centers for Disease Control and Prevention–defined AIDS, despite the competing mortality risks in these patients. About 20% of the deaths were liver-related, suggesting that greater hepatitis C virus awareness and treatment could increase survival

    Draft Genome Sequence of Bacillus coagulans GBI-30, 6086, a Widely Used Spore-Forming Probiotic Strain.

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    Bacillus coagulans GBI-30, 6086 is a safe strain, already available on the market, and characterized by certified beneficial effects.The draft genome sequence presented here constitutes the first pillar toward the identification of the molecular mechanisms responsiblefor its positive features and safety
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