Quantum Control of Interacting Bosons in Periodic Optical Lattice

We study the avoided crossings in the dynamics of quantum controlled excitations for an interacting two-boson system in an optical lattice. Specifically, we perform numerical simulations of quantum control in this system where driving pulses connect the undriven stationary states in a manner characteristic of Stimulated Raman Adiabatic Passage (STIRAP). We demonstrate that the dynamics of such a transition is affected by chaos induced avoided crossings, resulting in a loss in coherence of the final outcome in the adiabatic limit.Comment: Accepted for publication in Physica E. Typo corrections to final versio

Role of the geosphere in deep nuclear waste disposal – An England and Wales perspective

To dispose permanently of its higher activity nuclear waste England and Wales have chosen deep geological disposal as the most appropriate solution currently available. The purpose of this paper is to describe the main geological features, events and processes relevant to England and Wales that will need to be considered to demonstrate that a site is suitable for a geological disposal facility (GDF). England and Wales are in the early stages of a GDF siting process in which areas of interest are being evaluated using mainly existing data from surface mapping and hydrocarbon exploration and production. Sites are evaluated consistently under six overarching headings, three of which are impacted by their geological setting – safety, engineering feasibility and value for money. “Suitable” geology is that which is safe during the operational and long-term post-closure period, which could have a GDF and its accessways constructed within it, and which delivers value for money. A GDF needs to fulfil dual safety functions wherever it is located: long-term containment of radionuclides, and isolation of the waste from human actions and from natural processes such as glaciations and earthquakes. The role of the geosphere in delivering these safety functions is to provide a low-flux groundwater environment with geochemical conditions that minimise degradation of the engineered components of the GDF, to promote retention of mobilised radionuclides, and to protect the waste from the impacts of humans and natural processes. The containment function of a GDF is provided by a combination of rock and engineering generally referred to as the multibarrier system. It comprises the engineered barriers – solid wasteforms, canisters, buffers, backfill materials, plugs and seals – that work together with the rock to ensure long-term containment. The GDF Programme in England and Wales seeks to identify suitable geological environments for which bespoke engineered barriers can be tailored to optimize the performance of the multibarrier system. The post-closure period over which independent regulators will require a safety case to demonstrate the long-term containment and isolation capabilities of a GDF is up to 1 million years. The long timescales make post-closure safety assessments a unique feature of deep geological disposal programmes. A comprehensive site characterization programme will use information mostly from seismic surveying and deep investigation boreholes to establish adequate rock availability (host rock depth, thickness, areal extent and compartmentalisation), suitable properties and behaviour of the deep geological environment, and the constructability and operability of a potential GDF site including its surface to subsurface access ways. Nuclear Waste Services, the organisation tasked with developing a GDF in England and Wales, is currently engaged with four Community Partnerships through a volunteer siting process: three in west Cumbria, and one on the English east coast in Theddlethorpe, Lincolnshire. In all of these areas Mesozoic claystones have been provisionally identified as potentially suitable GDF host rocks and are being investigated further, with a dedicated 3D seismic survey acquired off the coast of Cumbria in 2022. The main conclusion to be drawn from this paper is that a GDF could be sited in a large number of geological settings in England and Wales, and that the success of the current siting process will largely depend on engaging effectively with willing communities and building enduring relationships with them

Formation of octapod MnO nanoparticles with enhanced magnetic properties through kinetically-controlled thermal decomposition of polynuclear manganese complexes

Polynuclear manganese complexes are used as precursors for the synthesis of manganese oxide nanoparticles (MnO NPs). Altering the thermal decomposition conditions can shift the nanoparticle product from spherical, thermodynamically-driven NPs to unusual, kinetically-controlled octapod structures. The resulting increased surface area profoundly alters the NP's surface-dependent magnetism and may have applications in nanomedicine

Geometric quantum computation with NMR

The experimental realisation of the basic constituents of quantum information processing devices, namely fault-tolerant quantum logic gates, requires conditional quantum dynamics, in which one subsystem undergoes a coherent evolution that depends on the quantum state of another subsystem. In particular, the subsystem may acquire a conditional phase shift. Here we consider a novel scenario in which this phase is of geometric rather than dynamical origin. As the conditional geometric (Berry) phase depends only on the geometry of the path executed it is resilient to certain types of errors, and offers the potential of an intrinsically fault-tolerant way of performing quantum gates. Nuclear Magnetic Resonance (NMR) has already been used to demonstrate both simple quantum information processing and Berry's phase. Here we report an NMR experiment which implements a conditional Berry phase, and thus a controlled phase shift gate. This constitutes the first elementary geometric quantum computation.Comment: Minor additions at request of referees. 4 pages revtex including 2 figures (1 eps). Nature in pres

The Impact of NOD2 Variants on Fecal Microbiota in Crohn's Disease and Controls Without Gastrointestinal Disease.

BACKGROUND/AIMS: Current models of Crohn's disease (CD) describe an inappropriate immune response to gut microbiota in genetically susceptible individuals. NOD2 variants are strongly associated with development of CD, and NOD2 is part of the innate immune response to bacteria. This study aimed to identify differences in fecal microbiota in CD patients and non-IBD controls stratified by NOD2 genotype. METHODS: Patients with CD and non-IBD controls of known NOD2 genotype were identified from patients in previous UK IBD genetics studies and the Cambridge bioresource (genotyped/phenotyped volunteers). Individuals with known CD-associated NOD2 mutations were matched to those with wild-type genotype. We obtained fecal samples from patients in clinical remission with low fecal calprotectin (<250 µg/g) and controls without gastrointestinal disease. After extracting DNA, the V1-2 region of 16S rRNA genes were polymerase chain reaction (PCR)-amplified and sequenced. Analysis was undertaken using the mothur package. Volatile organic compounds (VOC) were also measured. RESULTS: Ninety-one individuals were in the primary analysis (37 CD, 30 bioresource controls, and 24 household controls). Comparing CD with nonIBD controls, there were reductions in bacterial diversity, Ruminococcaceae, Rikenellaceae, and Christensenellaceae and an increase in Enterobacteriaceae. No significant differences could be identified in microbiota by NOD2 genotype, but fecal butanoic acid was higher in Crohn's patients carrying NOD2 mutations. CONCLUSIONS: In this well-controlled study of NOD2 genotype and fecal microbiota, we identified no significant genotype-microbiota associations. This suggests that the changes associated with NOD2 genotype might only be seen at the mucosal level, or that environmental factors and prior inflammation are the predominant determinant of the observed dysbiosis in gut microbiota.Funding was supported by CORE, the Digestive Diseases Foundation and the Wellcome Trust [grant number 097943 to NAK, 093885 to CAL and 098051 to Alan W Walker and Julian Parkhill . Dr. Walker receives core funding support from the Scottish Government Rural and Environmental Science and Analysis Service (RESAS). We also acknowledge the NIHR Biomedical Research Centre awards to Addenbrooke’s Hospital/University of Cambridge School of Clinical Medicine and acknowledge the NIHR Newcastle Biomedical Research Centre

Dynamic changes in the epigenomic landscape regulate human organogenesis and link to developmental disorders

How the genome activates or silences transcriptional programmes governs organ formation. Little is known in human embryos undermining our ability to benchmark the fidelity of stem cell differentiation or cell programming, or interpret the pathogenicity of noncoding variation. Here, we study histone modifications across thirteen tissues during human organogenesis. We integrate the data with transcription to build an overview of how the human genome differentially regulates alternative organ fates including by repression. Promoters from nearly 20,000 genes partition into discrete states. Key developmental gene sets are actively repressed outside of the appropriate organ without obvious bivalency. Candidate enhancers, functional in zebrafish, allow imputation of tissue-specific and shared patterns of transcription factor binding. Overlaying more than 700 noncoding mutations from patients with developmental disorders allows correlation to unanticipated target genes. Taken together, the data provide a comprehensive genomic framework for investigating normal and abnormal human development

A preliminary study of the effect of closed incision management with negative pressure wound therapy over high-risk incisions

Background Certain postoperative wounds are recognised to be associated with more complications than others and may be termed high-risk. Wound healing can be particularly challenging following high-energy trauma where wound necrosis and infection rates are high. Surgical incision for joint arthrodesis can also be considered high-risk as it requires extensive and invasive surgery and postoperative distal limb swelling and wound dehiscence are common. Recent human literature has investigated the use of negative pressure wound therapy (NPWT) over high-risk closed surgical incisions and beneficial effects have been noted including decreased drainage, decreased dehiscence and decreased infection rates. In a randomised, controlled study twenty cases undergoing distal limb high-energy fracture stabilisation or arthrodesis were randomised to NPWT or control groups. All cases had a modified Robert-Jones dressing applied for 72 h postoperatively and NPWT was applied for 24 h in the NPWT group. Morphometric assessment of limb circumference was performed at six sites preoperatively, 24 and 72 h postoperatively. Wound discharge was assessed at 24 and 72 h. Postoperative analgesia protocol was standardised and a Glasgow Composite Measure Pain Score (GCPS) carried out at 24, 48 and 72 h. Complications were noted and differences between groups were assessed. Results Percentage change in limb circumference between preoperative and 24 and 72 h postoperative measurements was significantly less at all sites for the NPWT group with exception of the joint proximal to the surgical site and the centre of the operated bone at 72 h. Median discharge score was lower in the NPWT group than the control group at 24 h. No significant differences in GCPS or complication rates were noted. Conclusions Digital swelling and wound discharge were reduced when NPWT was employed for closed incision management. Larger studies are required to evaluate whether this will result in reduced discomfort and complication rates postoperatively

Interferon regulatory factor 8-deficiency determines massive neutrophil recruitment but T cell defect in fast growing granulomas during tuberculosis

Following Mycobacterium tuberculosis (Mtb) infection, immune cell recruitment in lungs is pivotal in establishing protective immunity through granuloma formation and neogenesis of lymphoid structures (LS). Interferon regulatory factor-8 (IRF-8) plays an important role in host defense against Mtb, although the mechanisms driving anti-mycobacterial immunity remain unclear. In this study, IRF-8 deficient mice (IRF-8−/−) were aerogenously infected with a low-dose Mtb Erdman virulent strain and the course of infection was compared with that induced in wild-type (WT-B6) counterparts. Tuberculosis (TB) progression was examined in both groups using pathological, microbiological and immunological parameters. Following Mtb exposure, the bacterial load in lungs and spleens progressed comparably in the two groups for two weeks, after which IRF-8−/− mice developed a fatal acute TB whereas in WT-B6 the disease reached a chronic stage. In lungs of IRF-8−/−, uncontrolled growth of pulmonary granulomas and impaired development of LS were observed, associated with unbalanced homeostatic chemokines, progressive loss of infiltrating T lymphocytes and massive prevalence of neutrophils at late infection stages. Our data define IRF-8 as an essential factor for the maintenance of proper immune cell recruitment in granulomas and LS required to restrain Mtb infection. Moreover, IRF-8−/− mice, relying on a common human and mouse genetic mutation linked to susceptibility/severity of mycobacterial diseases, represent a valuable model of acute TB for comparative studies with chronically-infected congenic WT-B6 for dissecting protective and pathological immune reactions