There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Journal of Scientific Instruments Editor: Dr H R Lang Vol 28 and Supplement No 1, 1951 Pp xvi + 388 + iii + 80 (London: Institute of Physics, 1951) Bound, £3 12s; unbound, £3

/pdf/a-review-of-scientific-instruments-50cfd4j98s.pdf

A Review of Scientific Instruments

All aspects of microbiology, including virology, are covered. Areas of special interest include: physiology, biochemistry and genetics (including molecular biology and 'omic' studies); biotechnology and synthetic biology; pathogenicity (including medical, veterinary and plant pathogens particularly those relating to food security); environmental microbiology (including ecophysiology, ecogenomics and meta-omic studies); virology; food microbiology (from food production and spoilage to food-borne pathogens); taxonomy and systematics (including publication of novel species and taxonomic reclassifications), and professional development (including education, training, CPD, research assessment frameworks, research metrics, best-practice and history of microbiology).

FEMS microbiology letters

1. Introduction: From Physiology to DNA and Back.- 2. RNA Chain Initiation and Promoter Escape by RNA Polymerase.- Promoter Function is Regulated at Two Distinct Phases of Transcription: Promoter Binding and RNA Chain Initiation.- The Biochemistry of the RNA Chain Initiation Phase of Transcription.- Parameters That Describe the RNA Chain Initiation Reaction at Different Promoters.- Factors That Affect the Initiation Reaction: Intrinsic Factors.- Factors That Affect the Initiation Reaction: Extrinsic Factors.- Models for the Mechanism of RNA Chain Initiation: Some Simple Models Do Not Account for What Is Known.- Models for the Mechanism of RNA Chain Initiation-Models Based on Recent Models for RNA Chain Elongation.- 3. Transcription Termination and Its Control.- Termination.- Antitermination.- 4. Codon Context, Translational Step-Times and Attenuation.- Overview.- Attenuation.- Codon Context and Translational Efficiency.- Effects of Codon Pair Bias on Translational Step-Times.- Discussion.- 5. Control by Antisense RNA.- Antisense RNAs Control Diverse Biological Functions.- Antisense RNAs Control Gene Expression at Many Different Post-Transcriptional Levels.- Antisense RNAs Pair to Their Target RNAs by Defined Mechanisms.- Overview.- 6. Translational Control of Gene Expression in E. Coli and Bacteriophage.- Translation Initiation.- Translational Operators.- Translational Repressors.- Mechanisms of Control.- Translational Control and mRNA Processing and/or Degradation.- The Role of Translational Control in Growth Rate Regulation.- Conclusions and Perspectives.- 7. Effects of DNA Supercoiling on Gene Expression.- Synopsis.- The Dependence of Transcription on the Cellular Level of DNA Gyrase and DNA Topoisomerase I.- Mechanistic Considerations.- Supercoiling of the DNA Template by Transcription.- Concluding Remarks.- 8. The HU and IHF Proteins: Accessory Factors for Complex Protein-DNA Assemblies.- Perspective.- Structure.- Interaction with Nucleic Acids.- Control of Intracellular Concentration and Activity.- Participation of IHF and HU in Well-Characterized Biochemical Processes.- Unfinished Business.- 9. The lac and gal Operons Today.- The lac and gal Operons Encode Enzymes of a Continuous Biochemical Pathway.- The Regulatory Circuits and Their Components.- Modulation of Promoters by cAMP*CRP.- Control of P2 by UTP in gal.- Natural Polarity.- Negative Control by Repressor-Operator Interactions.- Epilogue.- 10. The Maltose System.- and Scope.- The Positive Transcriptional Activator MalT.- The Maltose/Maltodextrin Transport System.- The Enzymes of the Maltose System.- Nonclassical Regulatory Phenomena.- Perspectives.- 11. The Phosphoenolpyruvate-Dependent Carbohydrate: Phosphotransferase System (PTS) and Control of Carbon Source Utilization.- Regulatory Phenomena Related to Carbon Source Utilization.- Bacterial Transport Systems and Global Regulatory Networks Form a Unit.- The Bacterial PTS Is a Transport and Signal Transduction System.- IIAGlc of the PTS Is Central to Carbon Catabolite Repression.- IIAGlc, the Regulation of Adenylate Cyclase Activity and of Intracellular cAMP Levels.- Not Only cAMP Levels, but Also CRP Levels Are Essential in Catabolite Repression.- IIAGlc and Inducer Exclusion.- Catabolite Repression and Inducer Exclusion Act in Concert.- Carbon Catabolite Repression through PTS-Control Is Part of a Stimulon.- Concluding Remarks.- 12. The Cap Modulon.- The Long History of CAP.- Cyclic AMP and Gene Expression.- CAP as a Global Regulator: The CAP Modulon.- CAP Binding at Target Promoters and Structural Studies.- Activation by CAP at "Simple"CRP.- Control of P2 by UTP in gal.- Natural Polarity.- Negative Control by Repressor-Operator Interactions.- Epilogue.- 10. The Maltose System.- and Scope.- The Positive Transcriptional Activator MalT.- The Maltose/Maltodextrin Transport System.- The Enzymes of the Maltose System.- Nonclassical Regulatory Phenomena.- Perspectives.- 11. The Phosphoenolpyruvate-Dependent Carbohydrate: Phosphotransferase System (PTS) and Control of Carbon Source Utilization.- Regulatory Phenomena Related to Carbon Source Utilization.- Bacterial Transport Systems and Global Regulatory Networks Form a Unit.- The Bacterial PTS Is a Transport and Signal Transduction System.- IIAGlc of the PTS Is Central to Carbon Catabolite Repression.- IIAGlc, the Regulation of Adenylate Cyclase Activity and of Intracellular cAMP Levels.- Not Only cAMP Levels, but Also CRP Levels Are Essential in Catabolite Repression.- IIAGlc and Inducer Exclusion.- Catabolite Repression and Inducer Exclusion Act in Concert.- Carbon Catabolite Repression through PTS-Control Is Part of a Stimulon.- Concluding Remarks.- 12. The Cap Modulon.- The Long History of CAP.- Cyclic AMP and Gene Expression.- CAP as a Global Regulator: The CAP Modulon.- CAP Binding at Target Promoters and Structural Studies.- Activation by CAP at "Simple" Promoters.- Activation by CAP at Complex Promoters.- CAP as a Repressor and a Co-Repressor.- CAP: Paradigm or Artifact?.- 13. Regulation of Nitrogen Assimilation.- The glnALG(glnA ntrBC) Operon.- The ?54-Dependent Promoter.- Transcriptional Enhancers.- Phosphorylation of NRI.- NRI/NRII as Two-Component Paradigm.- Activation of Transcription.- Response to Nitrogen Availability.- 14. History of the Pho System.- 15. Are the Multiple Signal Transduction Pathways of the Pho Regulon Due to Cross Talk or Cross Regulation?.- Genes for Pi Control of the Pho Regulon.- Transmembrane Signaling by Environmental Pi.- Genes for Pi Independent Controls of the Pho Regulon.- Activation by CreC and Acetyl Phosphate.- Cross Talk, Cross Regulation and a Hypothesis.- Is There Evidence for Cross Regulation?.- Overview and Prospects for Future Studies.- 16. The FNR Modulon and FNR-Regulated Gene Expression.- The Metabolic Arena.- The FNR Modulon.- The FNR Protein and Relationships with CAP.- The DNA-Binding Specificity of FNR.- In Vitro Transcription Activation and Repression.- Transcriptional Organization of Representative Promoters.- Potential FNR Contacts with RNA Polymerase and DNA-Bending.- The Mystery of Redox-Sensing.- Structural and Functional Homologs of FNR.- Concluding Remarks.- 17. The NAR Modulon Systems: Nitrate and Nitrite Regulation of Anaerobic Gene Expression.- Anaerobic Respiration.- The Characterization of the Nar Regulatory System.- Dual Two-Component Regulatory Systems.- The Role of Nitrite in the Nar Regulatory System.- The Sensor Proteins.- The Response Regulators.- Indirect Nitrate Regulation of Gene Expression.- Concluding Remarks.- 18. Regulation of Aerobic and Anaerobic Metabolism by the Arc System.- Identification of the arc Genes.- In Vivo Studies of arc Mutants.- In Vitro Phosphorylation Studies.- The Arc Modulon.- ArcA DNA Binding.- The Arc Stimulus.- Future Studies.- 19. The Porin Regulon: A Paradigm for the Two-Component Regulatory Systems.- Background.- The History of Porin Regulation.- The Structure of the ompB Locus.- The Structure of the ompF and ompC Genes.- The Roles of OmpR and EnvZ.- Phosphorylation and Signal Transduction.- Summary and Conclusions.- 20. The Leucine\Lrp Regulon.- The Leucine-Responsive Regulatory Protein.- Regulation of Lrp Synthesis.- Target Operons of Lrp and Mutant Phenotypes.- Lrp as a Chromosome Organizer.- Molecular Aspects of Lrp Interactions at Individual Promoters.- 21. Adaptive responses to Oxidative Stress: The soxRS and oxyR Regulons.- Reactive Oxygen Species.- Antioxidant Defenses.- Oxidative Stress.- Global Responses to Oxidative Stress.- The soxRS Regulon.- The oxyR Regulon.- Control of Antibiotic Resistance Genes.- 22. The SOS Regulatory System.- and Current Regulatory Model.- Development of the SOS Model.- Recent Developments.- Behavior of the SOS Gene Regulatory Circuitry.- Future Prospects.- 23. Heat Shock Regulation.- Properties of Important Heat Shock Proteins.- Regulation of the ?32-Promoted Heat Shock Response.- A Second Heat Shock Regulon.- The ?54-Promoted Stress Response.- Heat Shock or Stress Responses in Other Eubacteria.- 24. Roles for Energy-Dependent Proteases in Regulatory Cascades.- The Proteases and Their Targets.- Summary and General Conclusions.- 25. Control of rRNA and Ribosome Synthesis.- rRNA Gene Organization.- High Activity of rRNA Synthesis Rates.- Stringent Control.- Growth Rate Dependent Control.- Additional Considerations.- Conclusion and Future Prospects.- 26. Cell Division.- The Cell Division Process.- Essential Cell Division Genes.- Transcriptional Regulation of Cell Division Genes.- Translational Control.- Division Inhibitors.- Cell Division Inhibition by Mutations in Genes That Do Not Code for Cell Division Proteins.- Past, Present and Future.- 27. Regulation of Gene Expression in Stationary Phase.- The ?s Regulon.- RpoS Regulation.

Regulation of Gene Expression in Escherichia Coli

Influence of Mg2+ and Temperature on Formation of the Transcription Bubble

Nucleation of RNA chain formation by Escherichia coli DNA-dependent RNA polymerase.

A new pathway to nuclear magnetic resonance (NMR) spectroscopy for picoliter-sized samples (including those kept in harsh and extreme environments, particularly in diamond anvil cells) is introduced, using inductively coupled broadband passive electromagnetic lenses, to locally amplify the magnetic field at the isolated sample, leading to an increase in sensitivity. The lenses are adopted for the geometrical restrictions imposed by a toroidal diamond indenter cell and yield signal-to-noise ratios at pressures as high as 72 GPa at initial sample volumes of only 230 pl. The corresponding levels of detection are found to be up to four orders of magnitude lower compared to formerly used solenoidal microcoils. Two-dimensional nutation experiments on long-chained alkanes, CnH2n+2 (n = 16 to 24), as well as homonuclear correlation spectroscopy on thymine, C5H6N2O2, were used to demonstrate the feasibility of this approach for higher-dimensional NMR experiments, with a spectral resolution of at least 2 parts per million. This approach opens up the field of ultrahigh-pressure sciences to one of the most versatile spectroscopic methods available in a pressure range unprecedented up to now.

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Magnetic flux tailoring through Lenz lenses for ultrasmall samples: A new pathway to high-pressure nuclear magnetic resonance

Hydrogen bond symmetrisations in H-bonded systems triggered by pressure-induced nuclear quantum effects (NQEs) is a long-known concept but experimental evidence in high-pressure ices has remained elusive with conventional methods. Theoretical works predicted quantum-mechanical tunneling of protons within water ices to occur at pressures above 30 GPa, and the H-bond symmetrisation transition to occur above 60 GPa. Here we used 1H-NMR on high-pressure ice up to 97 GPa, and demonstrate that NQEs govern the behavior of the hydrogen bonded protons in ice VII already at significantly lower pressures than previously expected. A pronounced tunneling mode was found to be present up to the highest pressures of 97 GPa, well into the stability field of ice X, where NQEs are not anticipated in a fully symmetrised H-bond network. We found two distinct transitions in the NMR shift data at about 20 GPa and 75 GPa attributed to the step-wise symmetrisation of the H-bond.

/pdf/observation-of-nuclear-quantum-effects-and-hydrogen-bond-4ap1ue0pxf.pdf

Observation of nuclear quantum effects and hydrogen bond symmetrisation in high pressure ice

Implementation of nuclear magnetic resonance in high pressure vessels is among the most demanding technological endeavours of the field, owing to inherently low signal amplitudes, low sensitivities of the resonator set-ups, and samples which are both difficult to handle and to access in the finished experimental set-up. The following chapter presents a review of the basic principles of generating pressures in excess of 1 GPa (= 10.000 atm), followed by a summary of suitable NMR resonators. Additionally, recent high pressure experiments on correlated and uncorrelated electronic system at pressures as high as 30 GPa will be covered.

Thomas Meier

Papers

Influence of Mg2+ and Temperature on Formation of the Transcription Bubble

Nucleation of RNA chain formation by Escherichia coli DNA-dependent RNA polymerase.

Magnetic flux tailoring through Lenz lenses for ultrasmall samples: A new pathway to high-pressure nuclear magnetic resonance

Observation of nuclear quantum effects and hydrogen bond symmetrisation in high pressure ice

At Its Extremes : NMR at Giga-Pascal Pressures