scholarly journals The role of pH in Tuber aestivum syn. uncinatum mycorrhiza development within commercial orchards

2013 ◽  
Vol 47 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Paul W. Thomas
Keyword(s):  
Soil Ph ◽  
Calcareous Soils ◽  
Low Ph ◽  
Tuber Aestivum ◽  
Truffle Cultivation ◽  
Data Points ◽  
Ph Level ◽  
A Site ◽  
Optimal Ph

The accepted advice when establishing a plantation of <em>Tuber aestivum</em> syn. <em>uncinatum</em> is that young inoculated trees should be planted on calcareous soils with a naturally high pH level. When a site is employed that has a naturally low pH level, lime is often applied to raise the pH to a considered ideal level of c.7.5. However, this may not be the correct approach. Here we present data from 33 data points taken from commercial truffle orchards in England, UK. Soil pH is correlated to <em>Tuber aestivum</em> syn. <em>uncinatum</em> mycorrhiza survivorship and development. The optimal observed pH was 7.51 but the actual optimal pH for cultivation may be higher. Sub optimal pH levels lead to a reduction of <em>Tuber aestivum</em> syn. <em>uncinatum</em> mycorrhiza. This reduction is not permanent and mycorrhization levels may be improved within a 12 month period by amending the soil pH. The importance of understanding the interaction of pH with other variables and the results in relation truffle cultivation are discussed.

pH-dependent modulation of Kv1.3 inactivation: role of His399

2004 ◽  
Vol 287 (4) ◽  
pp. C1067-C1076 ◽  
Author(s):  
Sándor Somodi ◽  
Zoltán Varga ◽  
Péter Hajdu ◽  
John G. Starkus ◽  
Daniel I. Levy ◽  
...  
Keyword(s):  
Ionic Strength ◽  
External Solution ◽  
Dissociation Rate ◽  
Low Ph ◽  
Slow Inactivation ◽  
Wild Type ◽  
External Application ◽  
Kv Channels ◽  
A Site

The Kv1.3 K+ channel lacks N-type inactivation, but during prolonged depolarized periods it inactivates via the slow (P/C type) mechanism. It bears a titratable histidine residue in position 399 (equivalent of Shaker 449), a site known to influence the rate of slow inactivation. As opposed to several other voltage-gated K+ channels, slow inactivation of Kv1.3 is slowed when extracellular pH (pHo) is lowered under physiological conditions. Our findings are as follows. First, when His399 was mutated to a lysine, arginine, leucine, valine or tyrosine, extracellular acidification (pH 5.5) accelerated inactivation reminiscent of other Kv channels. Second, inactivation of the wild-type channel was accelerated by low pHo when the ionic strength of the external solution was raised. Inactivation of the H399K mutant was also accelerated by high ionic strength at pH 7.35 but not the inactivation of H399L. Third, after the external application of blocking barium ions, recovery of the wild-type current during washout was slower in low pHo. Fourth, the dissociation rate of Ba2+ was pH insensitive for both H399K and H399L. Furthermore, Ba2+ dissociation rates were equal for H399K and the wild type at pH 5.5 and were equal for H399L and the wild type at pH 7.35. These observations support a model in which the electric field of the protonated histidines creates a potential barrier for potassium ions just outside the external mouth of the pore that hinders their exit from the binding site controlling inactivation. In Kv1.3, this effect overrides the generally observed speeding of slow inactivation when pHo is reduced.

The Return of Alsace to France, 1918-1939

2018 ◽  
Author(s):  
Alison Carrol
Keyword(s):  
National Policy ◽  
Third Republic ◽  
French Society ◽  
German Empire ◽  
Cross Border ◽  
The First World War ◽  
German Speaking ◽  
A Site ◽  
First World

In 1918 the end of the First World War triggered the return of Alsace to France after almost fifty years of annexation into the German Empire. Enthusiastic crowds in Paris and Alsace celebrated the homecoming of the so-called lost province, but return proved far less straightforward than anticipated. The region’s German-speaking population demonstrated strong commitment to local cultures and institutions, as well as their own visions of return to France. As a result, the following two decades saw politicians, administrators, industrialists, cultural elites, and others grapple with the question of how to make Alsace French again. The answer did not prove straightforward; differences of opinion emerged both inside and outside the region, and reintegration became a fiercely contested process that remained incomplete when war broke out in 1939. The Return of Alsace to France examines this story. Drawing upon national, regional, and local archives, it follows the difficult process of Alsace’s reintegration into French society, culture, political and economic systems, and legislative and administrative institutions. It connects the microhistory of the region with the macro levels of national policy, international relations, and transnational networks, and with the cross-border flows of ideas, goods, people, and cultural products that shaped daily life in Alsace. Revealing Alsace to be a site of exchange between a range of interest groups with different visions of the region’s future, this book underlines the role of regional populations and cross-border interactions in forging the French Third Republic.

scholarly journals Characteristics of Phomopsis juglandina (Sacc.) Hohn. Associated with Dieback of Walnut in the Climatic Conditions of Southern Romania

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 46
Author(s):  
Cristina Mihaescu ◽  
Daniel Dunea ◽  
Adrian Gheorghe Bășa ◽  
Loredana Neagu Frasin
Keyword(s):  
Growth Temperature ◽  
Potential Evapotranspiration ◽  
Optimal Growth ◽  
Climatic Conditions ◽  
Cultural Characteristics ◽  
Optimal Growth Temperature ◽  
Conidial State ◽  
Optimal Ph

Phomopsis juglandina (Sacc.) Höhn., which is the conidial state of Diaporthe juglandina (Fuckel) Nitschke, and the main pathogen causing the dieback of branches and twigs of walnut was recently detected in many orchards from Romania. The symptomatological, morphological, ultrastructural, and cultural characteristics, as well as the pathogenicity of an isolate of this lignicolous fungus, were described and illustrated. The optimum periods for infection, under the conditions prevailing in Southern Romania, mainly occur in the spring (April) and autumn months (late September-beginning of October). Strong inverse correlations (p < 0.001) were found between potential evapotranspiration and lesion lengths on walnut branches in 2019. The pathogen forms two types of phialospores: alpha and beta; the role of beta phialospores is not well known in pathogenesis. In Vitro, the optimal growth temperature of mycelial hyphae was in the range of 22–26 °C, and the optimal pH is 4.4–7. This pathogen should be monitored continuously due to its potential for damaging infestations of intensive plantations.

RNA secondary structure dependence in METTL3–METTL14 mRNA methylation is modulated by the N-terminal domain of METTL3

2020 ◽  
Vol 402 (1) ◽  
pp. 89-98
Author(s):  
Nathalie Meiser ◽  
Nicole Mench ◽  
Martin Hengesbach
Keyword(s):  
Secondary Structure ◽  
Rna Binding ◽  
Specific Protein ◽  
Structure Dependence ◽  
Terminal Domain ◽  
Methylation Assay ◽  
A Site ◽  
Methylation Activity

AbstractN6-methyladenosine (m6A) is the most abundant modification in mRNA. The core of the human N6-methyltransferase complex (MTC) is formed by a heterodimer consisting of METTL3 and METTL14, which specifically catalyzes m6A formation within an RRACH sequence context. Using recombinant proteins in a site-specific methylation assay that allows determination of quantitative methylation yields, our results show that this complex methylates its target RNAs not only sequence but also secondary structure dependent. Furthermore, we demonstrate the role of specific protein domains on both RNA binding and substrate turnover, focusing on postulated RNA binding elements. Our results show that one zinc finger motif within the complex is sufficient to bind RNA, however, both zinc fingers are required for methylation activity. We show that the N-terminal domain of METTL3 alters the secondary structure dependence of methylation yields. Our results demonstrate that a cooperative effect of all RNA-binding elements in the METTL3–METTL14 complex is required for efficient catalysis, and that binding of further proteins affecting the NTD of METTL3 may regulate substrate specificity.

scholarly journals The RelA hydrolase domain acts as a molecular switch for (p)ppGpp synthesis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Anurag Kumar Sinha ◽  
Kristoffer Skovbo Winther
Keyword(s):  
Active Sites ◽  
Molecular Switch ◽  
Cell Physiology ◽  
Synthetase Activity ◽  
Wild Type ◽  
Functional Studies ◽  
Loop Region ◽  
A Site ◽  
Trna Binding

AbstractBacteria synthesize guanosine tetra- and penta phosphate (commonly referred to as (p)ppGpp) in response to environmental stresses. (p)ppGpp reprograms cell physiology and is essential for stress survival, virulence and antibiotic tolerance. Proteins of the RSH superfamily (RelA/SpoT Homologues) are ubiquitously distributed and hydrolyze or synthesize (p)ppGpp. Structural studies have suggested that the shift between hydrolysis and synthesis is governed by conformational antagonism between the two active sites in RSHs. RelA proteins of γ-proteobacteria exclusively synthesize (p)ppGpp and encode an inactive pseudo-hydrolase domain. Escherichia coli RelA synthesizes (p)ppGpp in response to amino acid starvation with cognate uncharged tRNA at the ribosomal A-site, however, mechanistic details to the regulation of the enzymatic activity remain elusive. Here, we show a role of the enzymatically inactive hydrolase domain in modulating the activity of the synthetase domain of RelA. Using mutagenesis screening and functional studies, we identify a loop region (residues 114–130) in the hydrolase domain, which controls the synthetase activity. We show that a synthetase-inactive loop mutant of RelA is not affected for tRNA binding, but binds the ribosome less efficiently than wild type RelA. Our data support the model that the hydrolase domain acts as a molecular switch to regulate the synthetase activity.

scholarly journals Role of Anions in Low pH-induced Translocation of Diphtheria Toxin

1989 ◽  
Vol 264 (19) ◽  
pp. 11367-11372 ◽  
Author(s):  
J Ø Moskaug ◽  
K Sandvig ◽  
S Olsnes
Keyword(s):  
Diphtheria Toxin ◽  
Low Ph

scholarly journals A MODEL OF CREATIVE HERITAGE FOR INDUSTRY: DESIGNING NEW RULES WHILE PRESERVING THE PRESENT SYSTEM OF RULES

2021 ◽  
Vol 1 ◽  
pp. 141-150
Author(s):  
Honorine Harlé ◽  
Pascal Le Masson ◽  
Benoit Weil
Keyword(s):  
Case Studies ◽  
Design Process ◽  
Industry 4.0 ◽  
Innovation Management ◽  
Present System ◽  
Innovative Capability ◽  
Current Change ◽  
A Site ◽  
Do So

AbstractIn industry, there is at once a strong need for innovation and a need to preserve the existing system of production. Thus, although the literature insists on the necessity of the current change toward Industry 4.0, how to implement it remains problematic because the preservation of the factory is at stake. Moreover, the question of the evolution of the system depends on its innovative capability, but it is difficult to understand how a new rule can be designed and implemented in a factory. This tension between preservation and innovation is often explained in the literature as a process of creative destruction. Looking at the problem from another perspective, this article models the factory as a site of creative heritage, enabling creation within tradition, i.e., creating new rules while preserving the system of rules. Two case studies are presented to illustrate the model. The paper shows that design in the factory relies on the ability to validate solutions. To do so, the design process can explore and give new meaning to the existing rules. The role of innovation management is to choose the degree of revision of the rules and to make it possible.

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