Dark matter axion search using a Josephson Traveling wave parametric amplifier.

We describe the first implementation of a Josephson Traveling Wave Parametric Amplifier (JTWPA) in an axion dark matter search. The operation of the JTWPA for a period of about two weeks achieved sensitivity to axion-like particle dark matter with axion-photon couplings above 10-13 Ge V-1 over a narrow range of axion masses centered around 19.84 µeV by tuning the resonant frequency of the cavity over the frequency range of 4796.7-4799.5 MHz. The JTWPA was operated in the insert of the axion dark matter experiment as part of an independent receiver chain that was attached to a 0.56-l cavity. The ability of the JTWPA to deliver high gain over a wide (3 GHz) bandwidth has engendered interest from those aiming to perform broadband axion searches, a longstanding goal in this field.

Search for a Dark-Matter-Induced Cosmic Axion Background with ADMX.

We report the first result of a direct search for a cosmic axion background (CaB)-a relativistic background of axions that is not dark matter-performed with the axion haloscope, the Axion Dark Matter eXperiment (ADMX). Conventional haloscope analyses search for a signal with a narrow bandwidth, as predicted for dark matter, whereas the CaB will be broad. We introduce a novel analysis strategy, which searches for a CaB induced daily modulation in the power measured by the haloscope. Using this, we repurpose data collected to search for dark matter to set a limit on the axion photon coupling of a CaB originating from dark matter cascade decay via a mediator in the 800-995 MHz frequency range. We find that the present sensitivity is limited by fluctuations in the cavity readout as the instrument scans across dark matter masses. Nevertheless, we suggest that these challenges can be surmounted using superconducting qubits as single photon counters, and allow ADMX to operate as a telescope searching for axions emerging from the decay of dark matter. The daily modulation analysis technique we introduce can be deployed for various broadband rf signals, such as other forms of a CaB or even high-frequency gravitational waves.

The APPLE Tree programme: Active Prevention in People at risk of dementia through Lifestyle, bEhaviour change and Technology to build REsiliEnce-randomised controlled trial.

BACKGROUND: Large-scale trials of multidomain interventions show that modifying lifestyle and psychological risk factors can slow cognitive decline. We aim to determine if a lower intensity, personally tailored secondary dementia prevention programme for older people with subjective or mild objective memory decline, informed by behaviour change theory, reduces cognitive decline over 2 years. METHODS: A multi-site, single-blind randomised controlled trial recruiting 704 older adults at high dementia risk due to mild cognitive impairment (MCI) or subjective cognitive decline (SCD). Participants are randomised using 1:1 allocation ratio to the APPLE Tree intervention versus control arm (dementia prevention information), stratified by site. The intervention explores and implements strategies to promote healthy lifestyle, increase pleasurable activities and social connections and improve long-term condition self-management. Two facilitators trained and supervised by a clinical psychologist deliver ten, 1-h group video call sessions over 6 months (approximately every fortnight), video-call 'tea breaks' (less structured, facilitated social sessions) in intervening weeks and individual goal-setting phone calls every 2 weeks. From 6 to 12 months, participants meet monthly for 'tea breaks', with those not attending receiving monthly goal-setting phone calls. Participants receive a food delivery, pedometer and website access to cognitive training and information about lifestyle modification. Follow-ups for all outcome measures are at 12 and 24 months. The primary outcome is cognition (Neuropsychological Test Battery (NTB) score) at 24 months. Secondary outcomes are quality of life, cost per quality-adjusted life year (QALY) and wellbeing and lifestyle factors the intervention targets (diet, vascular risk, body weight, activity, sleep, anxiety, depression, social networks and loneliness, alcohol intake and smoking). Participants from purposively selected sites participate in qualitative process evaluation interviews, which will be analysed using thematic analytic methods. DISCUSSION: If effective, the intervention design, involving remote delivery and non-clinical facilitators, would facilitate intervention roll-out to older people with memory concerns. TRIAL REGISTRATION: ISRCTN17325135 . Registration date 27 November 2019.

Axion Dark Matter Experiment: Detailed design and operations.

Axion dark matter experiment ultra-low noise haloscope technology has enabled the successful completion of two science runs (1A and 1B) that looked for dark matter axions in the 2.66-3.1 µeV mass range with Dine-Fischler-Srednicki-Zhitnisky sensitivity [Du et al., Phys. Rev. Lett. 120, 151301 (2018) and Braine et al., Phys. Rev. Lett. 124, 101303 (2020)]. Therefore, it is the most sensitive axion search experiment to date in this mass range. We discuss the technological advances made in the last several years to achieve this sensitivity, which includes the implementation of components, such as the state-of-the-art quantum-noise-limited amplifiers and a dilution refrigerator. Furthermore, we demonstrate the use of a frequency tunable microstrip superconducting quantum interference device amplifier in run 1A, and a Josephson parametric amplifier in run 1B, along with novel analysis tools that characterize the system noise temperature.

Search for Invisible Axion Dark Matter in the 3.3-4.2 µeV Mass Range.

We report the results from a haloscope search for axion dark matter in the 3.3-4.2 µeV mass range. This search excludes the axion-photon coupling predicted by one of the benchmark models of "invisible" axion dark matter, the Kim-Shifman-Vainshtein-Zakharov model. This sensitivity is achieved using a large-volume cavity, a superconducting magnet, an ultra low noise Josephson parametric amplifier, and sub-Kelvin temperatures. The validity of our detection procedure is ensured by injecting and detecting blind synthetic axion signals.

Molecular Characterization of Mycoplasma pneumoniae Isolates in the United States from 2012 to 2018.

Mycoplasma pneumoniae is a major cause of community-acquired pneumonia. There are limited data in the United States on the molecular epidemiological characteristics of M. pneumoniae We collected 446 M. pneumoniae-positive specimens from 9 states between August 2012 and October 2018. Culture, antimicrobial susceptibility testing, P1 subtyping, and multilocus VNTR (variable-number tandem repeats) analysis (MLVA) were performed to characterize the isolates. Macrolide-resistant M. pneumoniae (MRMp) was detected in 37 (8.3%) specimens. P1 subtype 2 (P1-2) was the predominant P1 subtype (59.8%). P1 subtype distribution did not change significantly chronologically or geographically. The macrolide resistance rate in P1 subtype 1 (P1-1) samples was significantly higher than that in P1-2 (12.9% versus 5.5%). Six P1-2 variants were identified, including two novel types, and variant 2c was predominant (64.6%). P1-2 variants were distributed significantly differently among geographic regions. Classical P1-2 was more frequent in lower respiratory tract specimens and had longer p1 trinucleotide repeats. Classical P1-2 was most common in MRMp (35.7%), while variant 2c was most common in macrolide-susceptible M. pneumoniae (67.5%). Fifteen MLVA types were identified; 3-5-6-2 (41.7%), 4-5-7-2 (35.3%), and 3-6-6-2 (16.6%) were the major types, and four MLVA clusters were delineated. The distribution of MLVA types varied significantly over time and geographic location. The predominant MLVA type switched from 4-5-7-2 to 3-5-6-2 in 2015. MLVA type was associated with P1 subtypes and P1-2 variant types but not with macrolide resistance. To investigate the M. pneumoniae genotype shift and its impact on clinical presentations, additional surveillance programs targeting more diverse populations and prolonged sampling times are required.

Extended Search for the Invisible Axion with the Axion Dark Matter Experiment.

This Letter reports on a cavity haloscope search for dark matter axions in the Galactic halo in the mass range 2.81-3.31 µeV. This search utilizes the combination of a low-noise Josephson parametric amplifier and a large-cavity haloscope to achieve unprecedented sensitivity across this mass range. This search excludes the full range of axion-photon coupling values predicted in benchmark models of the invisible axion that solve the strong CP problem of quantum chromodynamics.

Macrolide-Resistant Mycoplasma pneumoniae in the United States as Determined from a National Surveillance Program.

There are sparse data to indicate the extent that macrolide-resistant Mycoplasma pneumoniae (MRMp) occurs in the United States or its clinical significance. Between 2015 and 2018, hospitals in 8 states collected and stored respiratory specimens that tested positive for M. pneumoniae and sent them to the University of Alabama at Birmingham, where real-time PCR was performed for detection of 23S rRNA mutations known to confer macrolide resistance. MRMp was detected in 27 of 360 specimens (7.5%). MRMp prevalence was significantly higher in the South and East (18.3%) than in the West (2.1%). A2063G was the predominant 23S rRNA mutation detected. MICs for macrolide-susceptible M. pneumoniae (MSMp) were ≤0.008 µg/ml, whereas MICs for MRMp were 16 to 32 µg/ml. Patients with MRMp infection were more likely to have a history of immunodeficiency or malignancy. Otherwise, there were no other significant differences in the clinical features between patients infected with MRMp and those infected with MSMp, nor were there any differences in radiographic findings, hospitalization rates, viral coinfections, the mean duration of antimicrobial treatment, or clinical outcomes. There was no significant change in MRMp incidence over time or according to age, sex, race/ethnicity, or status as an inpatient or an outpatient. Patients with MRMp were more likely to have received a macrolide prior to presentation, and their treatment was more likely to have been changed to a fluoroquinolone after presentation. This is the first national surveillance program for M. pneumoniae in the United States. Additional surveillance is needed to assess the clinical significance of MRMp and to monitor changes in MRMp prevalence.

Cr2Te3 Thin Films for Integration in Magnetic Topological Insulator Heterostructures.

Chromium telluride compounds are promising ferromagnets for proximity coupling to magnetic topological insulators (MTIs) of the Cr-doped (Bi,Sb)2(Se,Te)3 class of materials as they share the same elements, thus simplifying thin film growth, as well as due to their compatible crystal structure. Recently, it has been demonstrated that high quality (001)-oriented Cr2Te3 thin films with perpendicular magnetic anisotropy can be grown on c-plane sapphire substrate. Here, we present a magnetic and soft x-ray absorption spectroscopy study of the chemical and magnetic properties of Cr2Te3 thin films. X-ray magnetic circular dichroism (XMCD) measured at the Cr L2,3 edges gives information about the local electronic and magnetic structure of the Cr ions. We further demonstrate the overgrowth of Cr2Te3 (001) thin films by high-quality Cr-doped Sb2Te3 films. The magnetic properties of the layers have been characterized and our results provide a starting point for refining the physical models of the complex magnetic ordering in Cr2Te3 thin films, and their integration into advanced MTI heterostructures for quantum device applications.

Resonance Enhanced Multiphoton Ionization Detected Millimeter-Wave Absorption: The 115 GHz Line of CO.

We investigate the potential for sensitively detecting millimeter-wave absorption through multiphoton ionization using the lowest rotational transition in CO (X1Σ, J = 1 ← J = 0) at 115 GHz as a diagnostic tool. This transition represents an almost perfect realization of a quantum mechanical two-level system. In the experiment, the output of a powerful continuous millimeter-wave source with sub-kilohertz resolution propagates counter to a pulsed molecular beam, causing Doppler shifted resonances. Absorption is detected by monitoring the involved rotational levels through resonance enhanced multiphoton ionization (REMPI). Observed polarization, saturation and Doppler effects demonstrate that the interaction with the millimeter-wave field is coherent and can be simulated well using the results for the two-level system. The combination of these results indicates that the millimeter-wave field is approximated well by a Gaussian beam with beam waist around 15 mm and constant effective electric field amplitude on the molecular beam axis. Time-correlated frequency modulation in the form of a short rectangular pulse is used to follow the molecular trajectory from the source to the laser interaction region. The experiments clearly demonstrate a great potential of extending high-resolution molecular beam spectroscopy with mass specific REMPI detection into the sub-terahertz or terahertz regimes.

Crossover from lattice to plasmonic polarons of a spin-polarised electron gas in ferromagnetic EuO.

Strong many-body interactions in solids yield a host of fascinating and potentially useful physical properties. Here, from angle-resolved photoemission experiments and ab initio many-body calculations, we demonstrate how a strong coupling of conduction electrons with collective plasmon excitations of their own Fermi sea leads to the formation of plasmonic polarons in the doped ferromagnetic semiconductor EuO. We observe how these exhibit a significant tunability with charge carrier doping, leading to a polaronic liquid that is qualitatively distinct from its more conventional lattice-dominated analogue. Our study thus suggests powerful opportunities for tailoring quantum many-body interactions in solids via dilute charge carrier doping.

Defining sepsis on the wards: results of a multi-centre point-prevalence study comparing two sepsis definitions.

Our aim was to prospectively determine the predictive capabilities of SEPSIS-1 and SEPSIS-3 definitions in the emergency departments and general wards. Patients with National Early Warning Score (NEWS) of 3 or above and suspected or proven infection were enrolled over a 24-h period in 13 Welsh hospitals. The primary outcome measure was mortality within 30 days. Out of the 5422 patients screened, 431 fulfilled inclusion criteria and 380 (88%) were recruited. Using the SEPSIS-1 definition, 212 patients had sepsis. When using the SEPSIS-3 definitions with Sequential Organ Failure Assessment (SOFA) score ≥ 2, there were 272 septic patients, whereas with quickSOFA score ≥ 2, 50 patients were identified. For the prediction of primary outcome, SEPSIS-1 criteria had a sensitivity (95%CI) of 65% (54-75%) and specificity of 47% (41-53%); SEPSIS-3 criteria had a sensitivity of 86% (76-92%) and specificity of 32% (27-38%). SEPSIS-3 and SEPSIS-1 definitions were associated with a hazard ratio (95%CI) 2.7 (1.5-5.6) and 1.6 (1.3-2.5), respectively. Scoring system discrimination evaluated by receiver operating characteristic curves was highest for Sequential Organ Failure Assessment score (0.69 (95%CI 0.63-0.76)), followed by NEWS (0.58 (0.51-0.66)) (p < 0.001). Systemic inflammatory response syndrome criteria (0.55 (0.49-0.61)) and quickSOFA score (0.56 (0.49-0.64)) could not predict outcome. The SEPSIS-3 definition identified patients with the highest risk. Sequential Organ Failure Assessment score and NEWS were better predictors of poor outcome. The Sequential Organ Failure Assessment score appeared to be the best tool for identifying patients with high risk of death and sepsis-induced organ dysfunction.

Variation in the recall of socially rewarding information and depressive symptom severity: a prospective cohort study.

OBJECTIVE: To test the association between recall for socially rewarding (positive) and/or socially critical (negative) information and depressive symptoms. METHOD: Cohort study of people who had visited UK primary care in the past year reporting depressive symptoms (N = 558, 69% female). Positive and negative recall was assessed at three time-points, 2 weeks apart, using a computerised task. Depressive symptoms were assessed at four time-points using the Beck Depression Inventory (BDI). Analyses were conducted using multilevel models. RESULTS: Concurrently we found evidence that, for every increase in two positive words recalled, depressive symptoms reduced by 0.6 (95% CI -1.0 to -0.2) BDI points. This association was not affected by adjustment for confounders. There was no evidence of an association between negative recall and depressive symptoms (-0.1, 95% CI -0.5 to 0.3). Longitudinally, we found more evidence that positive recall was associated with reduced depressive symptoms than vice versa. CONCLUSION: People with more severe depressive symptoms recall less positive information, even if their recall of negative information is unaltered. Clinicians could put more emphasis on encouraging patients to recall positive, socially rewarding information, rather than trying to change negative interpretations of events that have already occurred.

Comparison of epidemiologically linked Campylobacter jejuni isolated from human and poultry sources.

Campylobacter jejuni is responsible for most foodborne bacterial infections worldwide including Australia. The aim of this study was to investigate a combination of typing methods in the characterization of C. jejuni isolated from clinical diarrhoeal samples (n = 20) and chicken meat (n = 26) in order to identify the source of infection and rank isolates based on their relative risk to humans. Sequencing of the flaA short variable region demonstrated that 86% of clinical isolates had genotypes that were also found in chicken meat. A polymerase chain reaction binary typing system identified 27 different codes based on the presence or absence of genes that have been reported to be associated with various aspects of C. jejuni pathogenicity, indicating that not all isolates may be of equal risk to human health. The lipooligosaccharide (LOS) of the C. jejuni isolates was classified into six classes (A, B, C, E, F, H) with 10·4% remaining unclassified. The majority (72·7%) of clinical isolates possessed sialylated LOS classes. Sialylated LOS classes were also detected in chicken isolates (80·7%). Antimicrobial tests indicated a low level of resistance, with no phenotypic resistance found to most antibiotics tested. A combination of typing approaches was useful to assign isolates to a source of infection and assess their risk to humans.

Hair and bone as predictors of tissular mercury concentration in the western Alaska red fox, Vulpes vulpes.

We evaluated if total mercury (THg) concentrations of keratin-based and bone-based tissues can predict THg concentrations in skeletal muscle, renal medulla, renal cortex, and liver. The THg concentration in matched tissues of 65 red foxes, Vulpes vulpes, from western Alaska was determined. Hair THg concentration had a significant positive correlation with liver, renal medulla, renal cortex, and muscle. The THg concentration for males and females is moderately predictive of THg concentration in the renal cortex and liver for these foxes based on R(2) values (R(2)=0.61 and 0.63, respectively). Bone is weakly predictive of THg concentration in muscle (R(2)=0.40), but not a reliable tissue to predict THg concentration in liver (R(2)=0.24), renal cortex (R(2)=0.35), or renal medulla (R(2)=0.25). These results confirm the potential use of trapped animals, specifically foxes, as useful Arctic sentinel species to inform researchers about patterns in THg levels over time as industrialization of the Arctic continues.

A reporter system for replication-competent gammaretroviruses: the inGluc-MLV-DERSE assay.

Although novel retroviral vectors for use in gene-therapy products are reducing the potential for formation of replication-competent retrovirus (RCR), it remains crucial to screen products for RCR for both research and clinical purposes. For clinical-grade gammaretrovirus-based vectors, RCR screening is achieved by an extended S(+)L(-) or marker-rescue assay, whereas standard methods for replication-competent lentivirus detection are still in development. In this report, we describe a rapid and sensitive method for replication-competent gammaretrovirus detection. We used this assay to detect three members of the gammaretrovirus family and compared the sensitivity of our assay with well-established methods for retrovirus detection, including the extended S(+)L(-) assay. Results presented here demonstrate that this assay should be useful for gene-therapy product testing.

Review: The role of mitochondria in the pathogenesis of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by loss of upper and lower motor neurones leading to muscle weakness and paralysis. Despite recent advances in the genetics of ALS, the mechanisms underlying motor neurone degeneration are not fully understood. Mitochondria are known to be involved in the pathogenesis of ALS, principally through mitochondrial dysfunction, the generation of free radicals, and impaired calcium handling in ALS patients and models of disease. However, recent studies have highlighted the potential importance of altered mitochondrial morphology and defective axonal transport of mitochondria in ALS. Here, we review the evidence for mitochondrial involvement in ALS and discuss potential therapeutic strategies targeting mitochondria.

Concentration and prevalence of Escherichia coli O157 and Salmonella serotypes in sheep during slaughter at two Australian abattoirs.

OBJECTIVE: This study aimed to determine the presence and concentration of Escherichia coli O157 and Salmonella spp. on fleece, faeces and carcases of sheep during slaughter. PROCEDURE: Faeces, fleece and pre-chill carcase samples were collected from 164 sheep slaughtered at two Australian abattoirs. The presence of E. coli O157 and Salmonella spp. were determined by use of automated immunomagnetic separation (AIMS) with enumeration by use of the 'most probable number' (MPN) method. RESULTS: Escherichia coli O157 was isolated from 5% of faeces, 3% of fleeces and 0.6% of pre-chill carcases. The mean log(10) count of E. coli O157 positive faecal samples was 2.32 MPN/g, but counts on fleeces and carcases were below the countable limit (-1 log(10) MPN/cm(2) ). Salmonella spp. were isolated from 20% of faeces, 13% of fleeces and 1.3% of pre-chill carcases. The mean log(10) count of Salmonella spp. in faeces was 1.43 MPN/g and on fleece was -0.24 MPN/cm(2) , but counts on carcases were below the countable limit (-1 log(10) MPN/cm(2) ). CONCLUSION: The prevalence and concentration of pathogens were low in the sheep tested in this study, indicating a low risk of human infection from products derived from these animals.