Demonstration of the trapped-ion quantum CCD computer architecture.

The trapped-ion quantum charge-coupled device (QCCD) proposal1,2 lays out a blueprint for a universal quantum computer that uses mobile ions as qubits. Analogous to a charge-coupled device (CCD) camera, which stores and processes imaging information as movable electrical charges in coupled pixels, a QCCD computer stores quantum information in the internal state of electrically charged ions that are transported between different processing zones using dynamic electric fields. The promise of the QCCD architecture is to maintain the low error rates demonstrated in small trapped-ion experiments3-5 by limiting the quantum interactions to multiple small ion crystals, then physically splitting and rearranging the constituent ions of these crystals into new crystals, where further interactions occur. This approach leverages transport timescales that are fast relative to the coherence times of the qubits, the insensitivity of the qubit states of the ion to the electric fields used for transport, and the low crosstalk afforded by spatially separated crystals. However, engineering a machine capable of executing these operations across multiple interaction zones with low error introduces many difficulties, which have slowed progress in scaling this architecture to larger qubit numbers. Here we use a cryogenic surface trap to integrate all necessary elements of the QCCD architecture-a scalable trap design, parallel interaction zones and fast ion transport-into a programmable trapped-ion quantum computer that has a system performance consistent with the low error rates achieved in the individual ion crystals. We apply this approach to realize a teleported CNOT gate using mid-circuit measurement6, negligible crosstalk error and a quantum volume7 of 26 = 64. These results demonstrate that the QCCD architecture provides a viable path towards high-performance quantum computers.

Eliminating Leakage Errors in Hyperfine Qubits.

Population leakage outside the qubit subspace presents a particularly harmful source of error that cannot be handled by standard error correction methods. Using a trapped ^{171}Yb^{+} ion, we demonstrate an optical pumping scheme to suppress leakage errors in atomic hyperfine qubits. The selection rules and narrow linewidth of a quadrupole transition are used to selectively pump population out of leakage states and back into the qubit subspace. Each pumping cycle reduces the leakage population by a factor of ∼3, allowing for an exponential suppression in the number of cycles. We use interleaved randomized benchmarking on the qubit subspace to show that this pumping procedure has negligible side effects on the qubit subspace, bounding the induced qubit memory error by ≤2.0(8)×10^{-5} per cycle, and qubit population decay to ≤1.4(3)×10^{-7} per cycle. These results clear a major obstacle for implementations of quantum error correction and error mitigation protocols.

Communication skills teaching for student dietitians using experiential learning and simulated patients.

BACKGROUND: Dietitians require communication competencies for effective dietetic practice. There is little evidence on how student dietitians experience and value communication skills teaching. The present study aimed to measure attitudes of student dietitians with respect to communication skills teaching and how experiential learning using simulated patients impacts confidence in their communication skills. METHODS: Communication skills teaching adopting an experiential skills-based approach including practice with simulated patients, feedback and reflection were developed. A 67-item questionnaire with three sections: (i) views regarding the importance of communication skills to dietetic practice; (ii) attitudes to learning communication skills using a modified Communication Skills Attitude Scale; and (iii) confidence in their own communication skills, was completed by students before and after the course, with responses recorded on a five-point Likert scale and analysed pairwise using McNemar's test. RESULTS: Over three academic years, 112 students (91.8% response rate) completed the evaluation. After training, students rated communication skills as important for patient satisfaction (100%) and relationships with patients (99.1%). Student dietitians had positive attitudes to learning communication skills with positive attitudes scale score before teaching of mean (SD) 53.6 (5.3) and after of 54.0 (5.8) (P = 0.162). Following experiential teaching, the proportion of students feeling 'very or extremely confident' in understanding a patient's perspective increased from 27.7% to 41.1% (P = 0.008) and for reaching agreement with a patient from 4.5% to 17.9% (P = 0.001). CONCLUSIONS: Student dietitians consider communication skills important for dietetic practice. They receive teaching positively and an experiential skills-based approach can improve self-rated confidence.

Priority setting for adult malnutrition and nutritional screening in healthcare: a James Lind Alliance.

BACKGROUND: Malnutrition is one the greatest global health challenges of our generation, leading to the increased utilisation of healthcare resources, as well as morbidity and mortality. Research has primarily been driven by industry, academia and clinical working groups and has had little involvement from patients and carers. The project described in the present study aimed to establish a priority setting partnership allowing patients, carers and healthcare professionals an opportunity to influence the research agenda. METHODS: A national survey was conducted to gather malnutrition uncertainties and identify key issues (i.e. areas within scope where an evidence-base is lacking) from those with experience of malnutrition. Uncertainties were analysed according to themes. Similar questions were grouped and summary questions were developed. A second survey was conducted and respondents were asked to choose their 10 most important summary questions. A workshop was conducted to finalise the top 10 research priorities from the most frequently indicated uncertainties on the interim survey. RESULTS: Overall, 1128 uncertainty questions were submitted from 268 people. The interim survey had 71 responses and a list of the top 26 questions was generated for the workshop. There were 26 questions discussed, ranked and agreed by healthcare professionals, carers and patients at the workshop. The top 10 research priorities were then chosen. These included questions on oral nutritional supplements, vulnerable groups, screening, community care, use of body mass index and technology. CONCLUSIONS: The top 10 research priorities in malnutrition and nutritional screening have been identified from a robust process involving patients, carers and healthcare professionals.

Photochemical Etching of Carbonyl Groups from a Carbon Matrix: The (001) Diamond Surface.

The surface of diamond is reported to undergo nonablative photochemical etching when exposed to ultraviolet (UV) radiation which allows controlled single and partial layer removal of lattice layers. Oxygen termination of surface dangling bonds is known to be crucial for the etching process; however, the exact mechanism of carbon ejection remains unclear. We investigate the interaction of UV laser pulses with oxygen-terminated diamond surfaces using atomic-scale surface characterization combined with first-principles time-dependent density functional theory calculations. We present evidence for laser-induced desorption (LID) from carbonyl functional groups at the diamond {001} surface. The doubly bonded carbonyl group is photoexcited into a triply bonded CO-like state, including scission of the underlying C─C bonds. The carbon removal process in LID is atom by atom; therefore, this mechanism provides a novel "top-down" approach for creating nanostructures on the surface of diamond and other carbon-containing semiconductors.

Oral nutrition support interventions for patients who are malnourished or at risk of malnutrition: a survey of clinical practice amongst UK dietitians.

BACKGROUND: Guidance on choosing oral nutritional support strategies varies and the evidence for different approaches is discordant. The present study aimed to examine opinion and practice in the use of oral nutritional support amongst UK dietitians and to assess the factors that influence these clinical decisions. METHODS: The study comprised a cross-sectional, anonymous, national survey of UK dietitians. RESULTS: There were 207 completed responses (3% response rate). More dietitians reported using combined approaches (COMB) [n = 129 (62%)] over food-based (FB) strategies [n = 70 (34%)] or oral nutritional supplements (ONS) alone [n = 8 (4%)] (N = 207, P < 0.001). Intervention choice was associated with clinical setting and clinical speciality; community dietitians reported more frequent use of FB or ONS alone [n = 48 (59%)] versus COMB [n = 34 (41%)] compared to acute dietitians [COMB: n = 83 (78%) COMB versus FB or ONS alone: n = 24 (22%)] (N = 207, P < 0.0001). Specialist nutrition support dietitians reported more frequent use of FB or ONS alone [n = 22 (54%)] versus COMB [n = 19 (46%)] compared to nonspecialists [FB or ONS alone: n = 17 (45%) versus COMB: n = 21 (55%)] and other specialist dietitians [FB or ONS: n = 39 (30%) alone versus COMB: n = 89 (70%)] (P = 0.017). The greatest influences on choice were ease of implementation [n = 192 (93%)], departmental protocols [n = 184 (89%)], professional management pathways [n = 179 (87%)] and published research [n = 165 (80%)]. Patient circumstances [n = 117 (57%) and n = 99 (48%)] and ease of implementation [n = 35 (17%) and n = 48 (24%)] were reported as most influential in the first and second case scenarios, respectively. CONCLUSIONS: There is a need for further research on approaches to the dietetic management of adult malnutrition.

Clustering of Nonergodic Eigenstates in Quantum Spin Glasses.

The two primary categories for eigenstate phases of matter at a finite temperature are many-body localization (MBL) and the eigenstate thermalization hypothesis (ETH). We show that, in the paradigmatic quantum p-spin models of the spin-glass theory, eigenstates violate the ETH yet are not MBL either. A mobility edge, which we locate using the forward-scattering approximation and replica techniques, separates the nonergodic phase at a small transverse field from an ergodic phase at a large transverse field. The nonergodic phase is also bounded from above in temperature, by a transition in configuration-space statistics reminiscent of the clustering transition in the spin-glass theory. We show that the nonergodic eigenstates are organized in clusters which exhibit distinct magnetization patterns, as characterized by an eigenstate variant of the Edwards-Anderson order parameter.

Experimental Study of Optimal Measurements for Quantum State Tomography.

Quantum tomography is a critically important tool to evaluate quantum hardware, making it essential to develop optimized measurement strategies that are both accurate and efficient. We compare a variety of strategies using nearly pure test states. Those that are informationally complete for all states are found to be accurate and reliable even in the presence of errors in the measurements themselves, while those designed to be complete only for pure states are far more efficient but highly sensitive to such errors. Our results highlight the unavoidable trade-offs inherent in quantum tomography.

Nutritional intervention as part of functional rehabilitation in older people with reduced functional ability: a systematic review and meta-analysis of randomised controlled studies.

BACKGROUND: Nutritional intervention is increasingly recognised as having an important role in functional rehabilitation for older people. Nonetheless, a greater understanding of the functional benefit of nutritional interventions is needed. METHODS: A systematic review and meta-analysis examined randomised controlled trials (RCTs) published between 2007 and 2014 with the aim of determining whether nutritional intervention combined with rehabilitation benefited older people with reduced functional ability. Six electronic databases were searched. RCTs including people aged 65 years and older with reduced physical, social and/or cognitive function were included. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed, and gradepro computer software (http://gradepro.org) was used for the quality assessment of critical and important outcomes. Included studies considered to be clinical homogenous were combined in a meta-analysis. RESULTS: Of the 788 studies screened, five were identified for inclusion. Nutritional intervention given with functional rehabilitation improved energy and protein intake, although it failed to provide any improvement in final body weight, hand-grip strength or muscle strength. There was no difference between groups in the critical outcomes; balance, cognition, activities of daily living and mortality at long-term follow-up. Nutritional intervention given with functional rehabilitation was associated with an increased likelihood of both mortality (odds ratio = 1.77; 95% confidence interval = 1.13-2.76) and hospitalisation (odds ratio = 2.29; 95% confidence interval = 1.10-4.79) during the intervention. Meta-analysis of the baseline data showed that, overall, the intervention cohort had a lower body weight and cognition. CONCLUSIONS: This meta-analysis highlights concerns regarding the quality of the randomisation of participants at baseline. Future high-quality research is essential to establish whether older people with loss of functional abilities can benefit from nutritional intervention.

BCL11A enhancer haplotypes and fetal hemoglobin in sickle cell anemia.

BACKGROUND: Fetal hemoglobin (HbF) levels in sickle cell anemia patients vary. We genotyped polymorphisms in the erythroid-specific enhancer of BCL11A to see if they might account for the very high HbF associated with the Arab-Indian (AI) haplotype and Benin haplotype of sickle cell anemia. METHODS AND RESULTS: Six BCL112A enhancer SNPs and their haplotypes were studied in Saudi Arabs from the Eastern Province and Indian patients with AI haplotype (HbF ~20%), African Americans (HbF ~7%), and Saudi Arabs from the Southwestern Province (HbF ~12%). Four SNPs (rs1427407, rs6706648, rs6738440, and rs7606173) and their haplotypes were consistently associated with HbF levels. The distributions of haplotypes differ in the 3 cohorts but not their genetic effects: the haplotype TCAG was associated with the lowest HbF level and the haplotype GTAC was associated with the highest HbF level and differences in HbF levels between carriers of these haplotypes in all cohorts were approximately 6%. CONCLUSIONS: Common HbF BCL11A enhancer haplotypes in patients with African origin and AI sickle cell anemia have similar effects on HbF but they do not explain their differences in HbF.

Supportive interventions for enhancing dietary intake in malnourished or nutritionally at-risk adults: a systematic review of nonrandomised studies.

BACKGROUND: Supportive interventions for enhancing dietary intake in malnourished or nutritionally at risk adults are frequently recommended. A recent systematic review of randomised controlled trials identified limited and poor quality evidence to support their use. Observational studies have been shown to compliment and extend their evidence. This review aimed to synthesise evidence from nonrandomised studies aiming to improve nutritional intake in nutritionally vulnerable individuals and to describe their effects on cost, nutritional, clinical and patient centred outcomes. METHODS: Systematic searches of 10 electronic databases were undertaken to May 2013. Reference lists of identified studies and systematic reviews were scrutinised and hand searching of relevant meeting abstracts was undertaken. Titles and abstracts were reviewed, data extracted by two research-ers working independently and summarised using a structured narrative format. RESULTS: Forty-one studies (n = 3751 participants) were identified for inclusion. Interventions identified included changes to the organisation of nutritional care (n = 15), changes to the feeding environment (n = 11), modification to meals (n = 6), supplementation of meals (n = 7) and recipients of home delivered meals (n = 2). Eighteen of 23 studies reported improvements in nutritional intake; however, effects on nutritional status, clinical outcomes and costs were reported in few studies and findings were inconsistent. Eighteen studies reported patient experience, highlighting benefits to nutritional status most commonly as judged by the carers but the methods used lacked rigour. CONCLUSIONS: This systematic review describes a range of interventions that may be implemented in clinical practice. A limited range of outcomes are reported and it is difficult to draw any meaningful conclusions on the effect of the different methods.

Trophic behaviour of juvenile reef fishes inhabiting interlinked mangrove-seagrass habitats in offshore mangrove islets.

Stable isotope (δ(13)C and δ(15)N) and gut content analyses were used to investigate size-related feeding habits of four reef fishes (the beaugregory Stegastes leucostictus, the french grunt Haemulon flavolineatum, the schoolmaster snapper Lutjanus apodus and the yellowtail snapper Ocyurus chrysurus) inhabiting an offshore (non-estuarine) mangrove islet off Belize, Central America. Comparisons of isotopic niche space and Schoener diet similarity index suggested a low to moderate degree of niche overlap between fish size groups. The δ(13)C gradient between mangrove and seagrass prey as well as results of Bayesian mixing models revealed that sampled fishes relied mostly on seagrass prey items. Only small and large juveniles of the carnivorous species L. apodus derived a part of their diet from mangroves by targeting mangrove-associated Grapsidae crabs and fish prey, respectively. Isotopic niche shifts were particularly obvious for carnivorous fishes that ingested larger prey items (Xanthidae crabs and fishes) during their ontogeny. The utilization of mangrove food resources is less than expected and depends on the ecology and life history of the fish species considered. This research highlights that mangrove-derived carbon contributed relatively little to the diets of four fish taxa from an offshore mangrove islet.

A genome-wide association study of post-traumatic stress disorder identifies the retinoid-related orphan receptor alpha (RORA) gene as a significant risk locus.

We describe the results of the first genome-wide association study (GWAS) of post-traumatic stress disorder (PTSD) performed using trauma-exposed white non-Hispanic participants from a cohort of veterans and their intimate partners (295 cases and 196 controls). Several single-nucleotide polymorphisms (SNPs) yielded evidence of association. One SNP (rs8042149), located in the retinoid-related orphan receptor alpha gene (RORA), reached genome-wide significance. Nominally significant associations were observed for other RORA SNPs in two African-American replication samples-one from the veteran cohort (43 cases and 41 controls) and another independent cohort (100 cases and 421 controls). However, only the associated SNP from the veteran African-American replication sample survived gene-level multiple-testing correction. RORA has been implicated in prior GWAS studies of psychiatric disorders and is known to have an important role in neuroprotection and other behaviorally relevant processes. This study represents an important step toward identifying the genetic underpinnings of PTSD.

Whole-exome sequencing and imaging genetics identify functional variants for rate of change in hippocampal volume in mild cognitive impairment.

Whole-exome sequencing of individuals with mild cognitive impairment, combined with genotype imputation, was used to identify coding variants other than the apolipoprotein E (APOE) ε4 allele associated with rate of hippocampal volume loss using an extreme trait design. Matched unrelated APOE ε3 homozygous male Caucasian participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) were selected at the extremes of the 2-year longitudinal change distribution of hippocampal volume (eight subjects with rapid rates of atrophy and eight with slow/stable rates of atrophy). We identified 57 non-synonymous single nucleotide variants (SNVs) which were found exclusively in at least 4 of 8 subjects in the rapid atrophy group, but not in any of the 8 subjects in the slow atrophy group. Among these SNVs, the variants that accounted for the greatest group difference and were predicted in silico as 'probably damaging' missense variants were rs9610775 (CARD10) and rs1136410 (PARP1). To further investigate and extend the exome findings in a larger sample, we conducted quantitative trait analysis including whole-brain search in the remaining ADNI APOE ε3/ε3 group (N=315). Genetic variation within PARP1 and CARD10 was associated with rate of hippocampal neurodegeneration in APOE ε3/ε3. Meta-analysis across five independent cross sectional cohorts indicated that rs1136410 is also significantly associated with hippocampal volume in APOE ε3/ε3 individuals (N=923). Larger sequencing studies and longitudinal follow-up are needed for confirmation. The combination of next-generation sequencing and quantitative imaging phenotypes holds significant promise for discovery of variants involved in neurodegeneration.

The quest for a true One Health perspective of brucellosis.

One Health is an interdisciplinary collaboration that aims at mitigating risks to human health arising from microorganisms present in non-human animal species, which have the potential to be transmitted and cause disease in humans. Different degrees of scientific collaboration and sectoral integration are needed for different types of zoonotic diseases, depending on the health and associated economic gains that can be expected from a One Health approach. Indeed, mitigating zoonotic risks related to emerging diseases with pandemic potential is different from mitigating risks related to endemic zoonotic diseases like brucellosis. Likewise, management of brucellosis at the wildlife-livestock interface in wildlife conservation areas is in essence different from mitigating transmission of a given Brucella species within its preferential host species, which in turn is different from mitigating the spillover of a given Brucella species to non-preferential host species, humans included. Brucellosis economic models often oversimplify and/or wrongly assess transmission between reservoir hosts and spillover hosts. Moreover,they may not properly value non-market outcomes, such as avoidance of human disease, consumer confidence and conservation biology issues. As a result, uncertainty is such that the economic predictions of these models can be questionable. Therefore, understanding the infection biology of Brucella species is a prerequisite. This paper reviews and highlights important features of the infection biology of Brucella species and the changing epidemiology of brucellosis that need to be integrated into a true One Health perspective of brucellosis.

Dietary counselling with or without oral nutritional supplements in the management of malnourished patients: a systematic review and meta-analysis of randomised controlled trials.

Dietary counselling and oral nutritional supplements (ONS) are recommended for managing malnutrition. A recent systematic review demonstrated (in separate analyses) that dietary counselling and dietary counselling with ONS improved energy intake, weight and some indices of body composition, although there was considerable heterogeneity. The present analysis aimed to examine the effects on mortality and nutritional indices of dietary counselling given with or without ONS and to explore the heterogeneity in the meta-analyses aiming to characterise the groups most likely to benefit from these interventions. A systematic review and meta-analysis was performed using Cochrane methodology. Twenty-six studies were included in the analysis: 12 comparing dietary counselling with usual care and 14 comparing dietary counselling and ONS if required with usual care (2123 participants). Quality of studies varied. Dietary counselling given with or without ONS had no effect on mortality [relative risk (fixed) = 1.12; 95% confidence interval = 0.86-1.46] but was associated with significant but heterogeneous benefits to weight [mean difference (random) = 1.7 kg; 95% confidence interval = 0.86-2.55], energy intake and some aspects of body composition. Subgroup analyses taking into account clinical background, age, nutritional status, type and length of intervention failed to reveal any differences in mortality, weight change and energy intake between groups. There were insufficient data on functional outcomes to explore these findings. Dietary counselling given with or without ONS is effective at increasing nutritional intake and weight but adequately-powered studies in similar patient populations and standardised for factors that might account for variations in response are required.

Outbreak of gastroenteritis caused by Yersinia pestis in Afghanistan.

Plague, which is most often caused by the bite of Yersinia pestis-infected fleas, is a rapidly progressing, serious disease that can be fatal without prompt antibiotic treatment. In late December 2007, an outbreak of acute gastroenteritis occurred in Nimroz Province of southern Afghanistan. Of the 83 probable cases of illness, 17 died (case fatality 20·5%). Being a case was associated with consumption or handling of camel meat (adjusted odds ratio 4·4, 95% confidence interval 2·2-8·8, P<0·001). Molecular testing of patient clinical samples and of tissue from the camel using PCR/electrospray ionization-mass spectrometry revealed DNA signatures consistent with Yersinia pestis. Confirmatory testing using real-time PCR and immunological seroconversion of one of the patients confirmed that the outbreak was caused by plague, with a rare gastrointestinal presentation. The study highlights the challenges of identifying infectious agents in low-resource settings; it is the first reported occurrence of plague in Afghanistan.

Simple nutritional intervention in patients with advanced cancers of the gastrointestinal tract, non-small cell lung cancers or mesothelioma and weight loss receiving chemotherapy: a randomised controlled trial.

BACKGROUND: Weight loss in patients with cancer is common and associated with a poorer survival and quality of life. Benefits from nutritional interventions are unclear. The present study assessed the effect of dietary advice and/or oral nutritional supplements on survival, nutritional endpoints and quality of life in patients with weight loss receiving palliative chemotherapy for gastrointestinal and non-small cell lung cancers or mesothelioma. METHODS: Participants were randomly assigned to receive no intervention, dietary advice, a nutritional supplement or dietary advice plus supplement before the start of chemotherapy. Patients were followed for 1 year. Survival, nutritional status and quality of life were assessed. RESULTS: In total, 256 men and 102 women (median age, 66 years; range 24-88 years) with gastrointestinal (n = 277) and lung (n = 81) cancers were recruited. Median (range) follow-up was 6 (0-49) months. One-year survival was 38.6% (95% confidence interval 33.3-43.9). No differences in survival, weight or quality of life between groups were seen. Patients surviving beyond 26 weeks experienced significant weight gain from baseline to 12 weeks, although this was independent of nutritional intervention. CONCLUSIONS: Simple nutritional interventions did not improve clinical or nutritional outcomes or quality of life. Weight gain predicted a longer survival but occurred independently of nutritional intervention.

Stable-isotope analyses reveal the importance of seagrass beds as feeding areas for juveniles of the speckled worm eel Myrophis punctatus (Teleostei: Ophichthidae) in Florida.

The feeding habits and habitats of the speckled worm eel Myrophis punctatus were studied on the mangrove edge of the Indian River Lagoon (IRL, Florida) using gut-content and stable-isotope analyses of carbon (δ(13) C) and nitrogen (δ(15) N). Four taxa were identified through analyses of gut contents, and the index of relative importance suggested that amphipods, microphytobenthos and annelids are the most important food sources in the fish's diet. To assess the feeding habits of the fish after their recruitment to the IRL, these food sources were collected from mangroves and nearby seagrass beds for isotope analyses. Stable isotopes constituted a powerful tool for discriminating fish prey items from mangroves (mean ± s.d.δ(13) C = -20·5 ± 0·6‰) and those from seagrass beds (mean ± s.d.δ(13) C = -16·9 ± 0·6‰), thus providing good evidence of food source origins. The 56 M. punctatus collected [10·0 < total length (L(T) ) < 16·2 cm] had average isotopic signatures of δ(13) C = -16·7 ± 0·2‰ and δ(15) N = 8·2 ± 0·1‰. A significant depletion in (13) C was observed for larger juveniles (15·0 < L(T) < 16·2 cm), suggesting that they found a portion of their food in mangroves. Estimation of the trophic level from stable isotopes (T(Liso)) was similar among different size groups of juvenile fish (T(Liso) = 3·2-3·5); therefore, M. punctatus was considered a secondary consumer, which is consistent with its zoobenthic diet. The concentration-dependent mixing Stable Isotope Analysis in R (SIAR) model revealed the importance of food sources from seagrass beds as carbon sources for all the fish collected, with a significant increase in mangrove prey contributions, such as annelids, in the diet of larger juveniles. This study highlights the importance of seagrass beds as feeding habitats for juveniles of M. punctatus after their recruitment to coastal waters.