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We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (
), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.
This study integrated an experimental medicine approach and a randomized cross-over clinical trial design following CONSORT recommendations to evaluate a cognitive training (CT) intervention for attention deficit hyperactivity disorder (ADHD). The experimental medicine approach was adopted because of documented pathophysiological heterogeneity within the diagnosis of ADHD. The cross-over design was adopted to provide the intervention for all participants and make maximum use of data.
Children (n = 93, mean age 7.3 +/− 1.1 years) with or sub-threshold for ADHD were randomly assigned to CT exercises over 15 weeks, before or after 15 weeks of treatment-as-usual (TAU). Fifteen dropped out of the CT/TAU group and 12 out of the TAU/CT group, leaving 66 for cross-over analysis. Seven in the CT/TAU group completed CT before dropping out making 73 available for experimental medicine analyses. Attention, response inhibition, and working memory were assessed before and after CT and TAU.
Children were more likely to improve with CT than TAU (27/66 v. 13/66, McNemar p = 0.02). Consistent with the experimental medicine hypotheses, responders improved on all tests of executive function (p = 0.009–0.01) while non-responders improved on none (p = 0.27–0.81). The degree of clinical improvement was predicted by baseline and change scores in focused attention and working memory (p = 0.008). The response rate was higher in inattentive and combined subtypes than hyperactive-impulsive subtype (p = 0.003).
Targeting cognitive dysfunction decreases clinical symptoms in proportion to improvement in cognition. Inattentive and combined subtypes were more likely to respond, consistent with targeted pathology and clinically relevant heterogeneity within ADHD.
Wind-driven snow redistribution can increase the spatial heterogeneity of snow accumulation on ice caps and ice sheets, and may prove crucial for the initiation and survival of glaciers in areas of marginal glaciation. We present a snowdrift model (Snow_Blow), which extends and improves the model of Purves, Mackaness and Sugden (1999, Journal of Quaternary Science 14, 313–321). The model calculates spatial variations in relative snow accumulation that result from variations in topography, using a digital elevation model (DEM) and wind direction as inputs. Improvements include snow redistribution using a flux routing algorithm, DEM resolution independence and the addition of a slope curvature component. This paper tests Snow_Blow in Antarctica (a modern environment) and reveals its potential for application in palaeoenvironmental settings, where input meteorological data are unavailable and difficult to estimate. Specifically, Snow_Blow is applied to the Ellsworth Mountains in West Antarctica where ablation is considered to be predominantly related to wind erosion processes. We find that Snow_Blow is able to replicate well the existing distribution of accumulating snow and snow erosion as recorded in and around Blue Ice Areas. Lastly, a variety of model parameters are tested, including depositional distance and erosion vs wind speed, to provide the most likely input parameters for palaeoenvironmental reconstructions.
Scholars have recently investigated the efficacy of applying globalisation models to ancient cultures such as the fourth-millennium BC Mesopotamian Uruk system. Embedded within globalisation models is the ‘complex connectivity‘ that brings disparate regions together into a singular world. In the fourth millennium BC, the site of Çadır Höyük on the north-central Anatolian plateau experienced dramatic changes in its material culture and architectural assemblages, which in turn reflect new socio-economic, sociopolitical and ritual patterns at this rural agro-pastoral settlement. This study examines the complex connectivities of the ancient Uruk system, encompassing settlements in more consistent contact with the Uruk system such as Arslantepe in southeastern Anatolia, and how these may have fostered exchange networks that reached far beyond the Uruk ‘global world‘ and onto the Anatolian plateau.
This study investigated the characteristics of subjective memory complaints (SMCs) and their association with current and future cognitive functions.
A cohort of 209 community-dwelling individuals without dementia aged 47–90 years old was recruited for this 3-year study. Participants underwent neuropsychological and clinical assessments annually. Participants were divided into SMCs and non-memory complainers (NMCs) using a single question at baseline and a memory complaints questionnaire following baseline, to evaluate differential patterns of complaints. In addition, comprehensive assessment of memory complaints was undertaken to evaluate whether severity and consistency of complaints differentially predicted cognitive function.
SMC and NMC individuals were significantly different on various features of SMCs. Greater overall severity (but not consistency) of complaints was significantly associated with current and future cognitive functioning.
SMC individuals present distinctive features of memory complaints as compared to NMCs. Further, the severity of complaints was a significant predictor of future cognition. However, SMC did not significantly predict change over time in this sample. These findings warrant further research into the specific features of SMCs that may portend subsequent neuropathological and cognitive changes when screening individuals at increased future risk of dementia.
The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.
Nearly 800,000 primary hip and knee arthroplasty procedures are performed annually in North America. Approximately 1% of these are complicated by a complex surgical site infection (SSI), leading to very high healthcare costs. However, population-based studies to properly estimate the economic burden are lacking. We aimed to address this knowledge gap.
Economic burden study.
Using administrative health and clinical databases, we created a cohort of all patients in Alberta, Canada, who received a primary hip or knee arthroplasty between April 1, 2012, and March 31, 2015. All patients who developed a complex SSI postoperatively were identified through a provincial infection prevention and control database. A combination of corporate microcosting data and gross costing methods were used to determine total mean 12- and 24-month costs, enabling comparison of costs between the infected and noninfected patients.
Mean 12-month total costs were significantly greater in patients who developed a complex SSI compared to those who did not (CAD$95,321 [US$68,150] vs CAD$19,893 [US$14,223]; P < .001). The magnitude of the cost difference persisted even after controlling for underlying patient factors. The most commonly identified causative pathogen (38%) was Staphylococcus aureus (95% MSSA).
Complex SSIs following hip and knee arthroplasty lead to high healthcare costs, which are expected to rise as the yearly number of surgeries increases. Using our costing estimates, the cost-effectiveness of different strategies to prevent SSIs should be investigated.
Canadian hospitals were made aware of the risk of Mycobacterium chimaera infection associated with heater-cooler units (HCUs) through alerts issued by the US food and Drug Administration (FDA) and the US Centers for Disease Control and Prevention (CDC). In response, most hospitals conducted retrospective reviews for infections, informed exposed patients, and initiated a requirement for informed consent with HCU use.
In this paper we review the design and development of a 100 J, 10 Hz nanosecond pulsed laser, codenamed DiPOLE100X, being built at the Central Laser Facility (CLF). This 1 kW average power diode-pumped solid-state laser (DPSSL) is based on a master oscillator power amplifier (MOPA) design, which includes two cryogenic gas cooled amplifier stages based on DiPOLE multi-slab ceramic Yb:YAG amplifier technology developed at the CLF. The laser will produce pulses between 2 and 15 ns in duration with precise, arbitrarily selectable shapes, at pulse repetition rates up to 10 Hz, allowing real-time shape optimization for compression experiments. Once completed, the laser will be delivered to the European X-ray Free Electron Laser (XFEL) facility in Germany as a UK-funded contribution in kind, where it will be used to study extreme states of matter at the High Energy Density (HED) instrument.
The availability of lidar datasets has led to several advances in archaeology, notably in the process of site prospection. Some remote sensing practitioners have aimed to create automated feature extraction (AFE) techniques that increase the efficiency and efficacy of identification and analysis. While these advances have been successful, many archaeological professionals who might have an interest in lidar-derived products do not have the technical experience to modify or create AFE techniques for particular regions or environments. Additionally, some features are not appropriate for AFE. Instead, the most widely used technique is still likely to be visually based manual feature identification. Using authors of different experience levels, we seek to evaluate the use of manual techniques for feature identification and subsequent analysis by implementing a publicly available lidar-derived digital elevation model (DEM). We demonstrate that manual feature extraction (MFE) can be accurate when more than one researcher is involved in a sort of “checks and balances” process. We also show that the use of confidence ratings can be an important part of this process if those ratings have some systematic and clearly defined underpinning. Finally, we argue, using a case study from American Samoa, that manually identified features can be analytically important as part of larger landscape studies.
The brain-derived neurotrophic factor (BDNF) Val66Met polymorphism Met allele exacerbates amyloid (Aβ) related decline in episodic memory (EM) and hippocampal volume (HV) over 36–54 months in preclinical Alzheimer's disease (AD). However, the extent to which Aβ+ and BDNF Val66Met is related to circulating markers of BDNF (e.g. serum) is unknown. We aimed to determine the effect of Aβ and the BDNF Val66Met polymorphism on levels of serum mBDNF, EM, and HV at baseline and over 18-months.
Non-demented older adults (n = 446) underwent Aβ neuroimaging and BDNF Val66Met genotyping. EM and HV were assessed at baseline and 18 months later. Fasted blood samples were obtained from each participant at baseline and at 18-month follow-up. Aβ PET neuroimaging was used to classify participants as Aβ– or Aβ+.
At baseline, Aβ+ adults showed worse EM impairment and lower serum mBDNF levels relative to Aβ- adults. BDNF Val66Met polymorphism did not affect serum mBDNF, EM, or HV at baseline. When considered over 18-months, compared to Aβ– Val homozygotes, Aβ+ Val homozygotes showed significant decline in EM and HV but not serum mBDNF. Similarly, compared to Aβ+ Val homozygotes, Aβ+ Met carriers showed significant decline in EM and HV over 18-months but showed no change in serum mBDNF.
While allelic variation in BDNF Val66Met may influence Aβ+ related neurodegeneration and memory loss over the short term, this is not related to serum mBDNF. Longer follow-up intervals may be required to further determine any relationships between serum mBDNF, EM, and HV in preclinical AD.
Complex developmental trauma impacts on neurobiological development through the creation of a frightening and unpredictable environment in which the brain develops. This early experience results in an under-developed limbic system and pre-frontal cortex. For some children and young people, their experiences of early trauma lead them into the residential Out-of-Home Care (OOHC) system. Neurodevelopmental delays that occur as a result of early trauma and abuse often become particularly pronounced during adolescence, including limited impulse control, poor emotional regulation and attachment impairments. These same delays contribute to offending behaviour and subsequent contact with the justice system. Complex developmental trauma has serious repercussions both for the individual and the society in which he or she lives. These repercussions may take the form of offending behaviour and contact with the justice system, drug and alcohol abuse, and continuing cycles of abuse and violence within families or victimisation.
Hip and knee arthroplasty infections are associated with considerable healthcare costs. The merits of reducing the postoperative surveillance period from 1 year to 90 days have been debated.
To report the first pan-Canadian hip and knee periprosthetic joint infection (PJI) rates and to describe the implications of a shorter (90-day) postoperative surveillance period.
Prospective surveillance for infection following hip and knee arthroplasty was conducted by hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) using standard surveillance definitions.
Overall hip and knee PJI rates were 1.64 and 1.52 per 100 procedures, respectively. Deep incisional and organ-space hip and knee PJI rates were 0.96 and 0.71, respectively. In total, 93% of hip PJIs and 92% of knee PJIs were identified within 90 days, with a median time to detection of 21 days. However, 11%–16% of deep incisional and organ-space infections were not detected within 90 days. This rate was reduced to 3%–4% at 180 days post procedure. Anaerobic and polymicrobial infections had the shortest median time from procedure to detection (17 and 18 days, respectively) compared with infections due to other microorganisms, including Staphylococcus aureus.
PJI rates were similar to those reported elsewhere, although differences in national surveillance systems limit direct comparisons. Our results suggest that a postoperative surveillance period of 90 days will detect the majority of PJIs; however, up to 16% of deep incisional and organ-space infections may be missed. Extending the surveillance period to 180 days could allow for a better estimate of disease burden.
The glycaemic and insulin indices assess postprandial glycaemic and insulin response to foods, respectively, which may not reflect the long-term effects of diet on insulin response. We developed and evaluated the validity of four empirical indices to assess the insulinaemic potential of usual diets and lifestyles, using dietary, lifestyle and biomarker data from the Nurses’ Health Study (NHS, n 5812 for hyperinsulinaemia, n 3929 for insulin resistance). The four indices were as follows: the empirical dietary index for hyperinsulinaemia (EDIH) and the empirical lifestyle index for hyperinsulinaemia (ELIH); the empirical dietary index for insulin resistance (EDIR) and the empirical lifestyle index for insulin resistance (ELIR). We entered thirty-nine FFQ-derived food groups in stepwise linear regression models, and defined indices as patterns most predictive of fasting plasma C-peptide, for the hyperinsulinaemia pathway (EDIH and ELIH), and of theTAG:HDL-cholesterol ratio, for the insulin-resistance pathway (EDIR and ELIR). We evaluated the validity of indices in two independent samples from NHS-II and Health Professionals Follow-up Study (HPFS) using multivariable-adjusted linear regression analyses to calculate relative concentrations of biomarkers. The EDIH is comprised of eighteen food groups; thirteen were positively associated with C-peptide and five were inversely associated. The EDIR is comprised of eighteen food groups; ten were positively associated with TAG:HDL-cholesterol and eight were inversely associated. Lifestyle indices had fewer dietary components, and included BMI and physical activity as components. In the validation samples, all indices significantly predicted biomarker concentrations – for example, the relative concentrations of the corresponding biomarkers comparing extreme index quintiles in the HPFS were EDIH, 1·29 (95 % CI 1·22, 1·37); ELIH, 1·78 (95 % CI 1·68, 1·88); EDIR, 1·44 (95 % CI 1·34, 1·55); and ELIR, 2·03 (95 % CI 1·89, 2·19); all Ptrend<0·0001. The robust associations of these novel hypothesis-driven indices with insulin response biomarker concentrations suggest their usefulness in assessing the ability of whole diets and lifestyles to stimulate and/or sustain insulin secretion.
Curcumin therapy in animals has produced positive cognitive and behavioural outcomes; results of human trials, however, have been inconsistent. In this study, we report the results of a 12-month, randomised, placebo-controlled, double-blind study that investigated the ability of a curcumin formulation to prevent cognitive decline in a population of community-dwelling older adults. Individuals (n 96) ingested either placebo or 1500 mg/d BiocurcumaxTM for 12 months. A battery of clinical and cognitive measures was administered at baseline and at the 6-month and 12-month follow-up assessments. A significant time×treatment group interaction was observed for the Montreal Cognitive Assessment (repeated-measures analysis; time×treatment; F=3·85, P<0·05). Subsequent analysis revealed that this association was driven by a decline in function of the placebo group at 6 months that was not observed in the curcumin treatment group. No differences were observed between the groups for all other clinical and cognitive measures. Our findings suggest that further longitudinal assessment is required to investigate changes in cognitive outcome measures, ideally in conjunction with biological markers of neurodegeneration.
Individuals have various kinds of obligations: keep promises, don’t cause harm, return benefits received from injustices, be partial to loved ones, help the needy and so on. How does this work for group agents? There are two questions here. The first is whether groups can bear the same kinds of obligations as individuals. The second is whether groups’ pro tanto obligations plug into what they all-things-considered ought to do to the same degree that individuals’ pro tanto obligations plug into what they all-things-considered ought to do. We argue for parity on both counts.
Based on a cohort of 966 patients, routine surveillance data were not sufficiently accurate for use in clinical trials investigating surgical site infections. Surveillance data can only be used if adequate 90-day follow-up is provided and if cases identified by surveillance are independently reviewed by a blinded outcome adjudication committee.
Bloodstream infection (BSI) due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with considerable morbidity and mortality.
To determine the incidence of MRSA BSI in Canadian hospitals and to identify variables associated with increased mortality.
Prospective surveillance for MRSA BSI conducted in 53 Canadian hospitals from January 1, 2008, through December 31, 2012. Thirty-day all-cause mortality was determined, and logistic regression analysis was used to identify variables associated with mortality.
A total of 1,753 patients with MRSA BSI were identified (incidence, 0.45 per 1,000 admissions). The most common sites presumed to be the source of infection were skin/soft tissue (26.6%) and an intravascular catheter (22.0%). The most common spa types causing MRSA BSI were t002 (USA100/800; 55%) and t008 (USA300; 29%). Thirty-day all-cause mortality was 23.8%. Mortality was associated with increasing age (odds ratio, 1.03 per year [95% CI, 1.02–1.04]), the presence of pleuropulmonary infection (2.3 [1.4–3.7]), transfer to an intensive care unit (3.2 [2.1–5.0]), and failure to receive appropriate antimicrobial therapy within 24 hours of MRSA identification (3.2 [2.1–5.0]); a skin/soft-tissue source of BSI was associated with decreased mortality (0.5 [0.3–0.9]). MRSA genotype and reduced susceptibility to vancomycin were not associated with risk of death.
This study provides additional insight into the relative impact of various host and microbial factors associated with mortality in patients with MRSA BSI. The results emphasize the importance of ensuring timely receipt of appropriate antimicrobial agents to reduce the risk of an adverse outcome.
Infect. Control Hosp. Epidemiol. 2016;37(4):390–397