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High-intensity laser–plasma interactions produce a wide array of energetic particles and beams with promising applications. Unfortunately, the high repetition rate and high average power requirements for many applications are not satisfied by the lasers, optics, targets, and diagnostics currently employed. Here, we aim to address the need for high-repetition-rate targets and optics through the use of liquids. A novel nozzle assembly is used to generate high-velocity, laminar-flowing liquid microjets which are compatible with a low-vacuum environment, generate little to no debris, and exhibit precise positional and dimensional tolerances. Jets, droplets, submicron-thick sheets, and other exotic configurations are characterized with pump–probe shadowgraphy to evaluate their use as targets. To demonstrate a high-repetition-rate, consumable, liquid optical element, we present a plasma mirror created by a submicron-thick liquid sheet. This plasma mirror provides etalon-like anti-reflection properties in the low field of 0.1% and high reflectivity as a plasma, 69%, at a repetition rate of 1 kHz. Practical considerations of fluid compatibility, in-vacuum operation, and estimates of maximum repetition rate are addressed. The targets and optics presented here demonstrate a potential technique for enabling the operation of laser–plasma interactions at high repetition rates.
Habitat loss and fragmentation are major threats to biodiversity worldwide, and little is known about their effects on bats in Africa. We investigated effects of forest fragmentation on bat assemblages at Kakamega Forest, western Kenya, examining captures at edge and interior locations in three forest fragments (Buyangu, 3950 ha; Kisere, 400 ha; and Malava, 100 ha) varying in forest area and human-use regimes. Basal area, canopy cover, tree density and intensity of human use were used as predictors of bat abundance and species richness. A total of 3456 mist-net hours and 3168 harp-trap hours resulted in the capture of 4983 bats representing 26 species, eight families and four foraging ensembles (frugivores, forest-interior insectivores, forest-edge insectivores and open-space insectivores). Frugivores were frequently captured at the edges of the larger, better-protected forests, but also in the interior of the smaller, more open fragment. Forest-interior insectivores and narrow-space foragers predominated in the interiors of larger fragments but avoided the smallest one. Forest specialists showed positive associations with forest variables (canopy cover, basal area and tree density), whereas frugivores responded positively to the human-use indicators. On these bases, specialist species appear to be especially vulnerable to forest fragmentation.
Clostridioides difficile infection (CDI) remains a significant public health concern, resulting in excess morbidity, mortality, and costs. Additional insight into the burden of CDI in adults aged <65 years is needed.
A 6-year retrospective cohort study was conducted using data extracted from United States Veterans Health Administration electronic medical records.
Patients aged 18–64 years on January 1, 2011, were followed until incident CDI, death, loss-to-follow-up, or December 31, 2016. CDI was identified by a diagnosis code accompanied by metronidazole, vancomycin, or fidaxomicin therapy, or positive laboratory test. The clinical setting of CDI onset was defined according to 2017 SHEA-IDSA guidelines.
Of 1,073,900 patients, 10,534 had a CDI during follow-up. The overall incidence rate was 177 CDIs per 100,000 person years, rising steadily from 164 per 100,000 person years in 2011 to 189 per 100,000 person years in 2016. Those with a CDI were slightly older (55 vs 51 years) and sicker, with a higher baseline Charlson comorbidity index score (1.4 vs 0.5) than those without an infection. Nearly half (48%) of all incident CDIs were community associated, and this proportion rose from 41% in 2011 to 56% in 2016.
The findings from this large retrospective study indicate that CDI incidence, driven primarily by increasing community-associated infection, is rising among young and middle-aged adult Veterans with high service-related disability. The increasing burden of community associated CDI in this vulnerable population warrants attention. Future studies quantifying the economic and societal burden of CDI will inform decisions surrounding prevention strategies.
Polymer additives can substantially reduce the drag of turbulent flows and the upper limit, the so-called state of ‘maximum drag reduction’ (MDR), is to a good approximation independent of the type of polymer and solvent used. Until recently, the consensus was that, in this limit, flows are in a marginal state where only a minimal level of turbulence activity persists. Observations in direct numerical simulations at low Reynolds numbers (
) using minimal sized channels appeared to support this view and reported long ‘hibernation’ periods where turbulence is marginalized. In simulations of pipe flow at
near transition we find that, indeed, with increasing Weissenberg number (
), turbulence expresses long periods of hibernation if the domain size is small. However, with increasing pipe length, the temporal hibernation continuously alters to spatio-temporal intermittency and here the flow consists of turbulent puffs surrounded by laminar flow. Moreover, upon an increase in
, the flow fully relaminarizes, in agreement with recent experiments. At even larger
, a different instability is encountered causing a drag increase towards MDR. Our findings hence link earlier minimal flow unit simulations with recent experiments and confirm that the addition of polymers initially suppresses Newtonian turbulence and leads to a reverse transition. The MDR state on the other hand results at these low
from a separate instability and the underlying dynamics corresponds to the recently proposed state of elasto-inertial turbulence.
Maier and Fadel pioneered Affordance-Based Design (ABD) based on Gibson's revolutionary theory of affordances and Norman's deployment of the concept in his book, “The Design of Everyday Things”. Gibson (1979) introduced the affordance concept into the discipline of Ecological Psychology to address the interactions between an object and an agent. The Ecological approach includes the direct perception of affordances for the user along with a consideration of the users’ biomechanics. However, as the concept of affordance was imported and utilized in different disciplines, including engineering design, some important aspects of Ecological theory were omitted.
This paper is an attempt to review the definitions and different utilizations of the affordance concept focusing on the design of usable products to identify the different views and the missing elements. After addressing the divergent viewpoints of affordances, we provide recommendations to improve the usability aspects in ABD by considering direct perception and ergonomics. We claim that a design (based on affordances) that fails to address both criteria may result in a product that is less usable.
The proper functioning of central lines is imperative for the management of patients with cancer or on hemodialysis. However, these lifelines can become infected and can malfunction.
Chelators such as citrate and EDTA have been widely studied alone or in combination with other antimicrobial agents in catheter lock solutions to prevent catheter-related bloodstream infections and to maintain catheter patency. Given their anticoagulation, antiplatelet aggregation, antibiofilm, antimicrobial activity, safety profile, as well as their low cost, chelators have long been considered alternatives to heparin and a vital component of catheter lock solutions. In this review, we present a detailed summary of the properties of chelators and in vitro and in vivo studies of chelator-containing lock solutions.
A national need is to prepare for and respond to accidental or intentional disasters categorized as chemical, biological, radiological, nuclear, or explosive (CBRNE). These incidents require specific subject-matter expertise, yet have commonalities. We identify 7 core elements comprising CBRNE science that require integration for effective preparedness planning and public health and medical response and recovery. These core elements are (1) basic and clinical sciences, (2) modeling and systems management, (3) planning, (4) response and incident management, (5) recovery and resilience, (6) lessons learned, and (7) continuous improvement. A key feature is the ability of relevant subject matter experts to integrate information into response operations. We propose the CBRNE medical operations science support expert as a professional who (1) understands that CBRNE incidents require an integrated systems approach, (2) understands the key functions and contributions of CBRNE science practitioners, (3) helps direct strategic and tactical CBRNE planning and responses through first-hand experience, and (4) provides advice to senior decision-makers managing response activities. Recognition of both CBRNE science as a distinct competency and the establishment of the CBRNE medical operations science support expert informs the public of the enormous progress made, broadcasts opportunities for new talent, and enhances the sophistication and analytic expertise of senior managers planning for and responding to CBRNE incidents.
Lipid-based nutrient supplements (LNS) may be beneficial for malnourished HIV-infected patients starting antiretroviral therapy (ART). We assessed the effect of adding vitamins and minerals to LNS on body composition and handgrip strength during ART initiation. ART-eligible HIV-infected patients with BMI <18·5 kg/m2 were randomised to LNS or LNS with added high-dose vitamins and minerals (LNS-VM) from referral for ART to 6 weeks post-ART and followed up until 12 weeks. Body composition by bioelectrical impedance analysis (BIA), deuterium (2H) diluted water (D2O) and air displacement plethysmography (ADP), and handgrip strength were determined at baseline and at 6 and 12 weeks post-ART, and effects of LNS-VM v. LNS at 6 and 12 weeks investigated. BIA data were available for 1461, D2O data for 479, ADP data for 498 and handgrip strength data for 1752 patients. Fat mass tended to be lower, and fat-free mass correspondingly higher, by BIA than by ADP or D2O. At 6 weeks post-ART, LNS-VM led to a higher regain of BIA-assessed fat mass (0·4 (95 % CI 0·05, 0·8) kg), but not fat-free mass, and a borderline significant increase in handgrip strength (0·72 (95 % CI −0·03, 1·5) kg). These effects were not sustained at 12 weeks. Similar effects as for BIA were seen using ADP or D2O but no differences reached statistical significance. In conclusion, LNS-VM led to a higher regain of fat mass at 6 weeks and to a borderline significant beneficial effect on handgrip strength. Further research is needed to determine appropriate timing and supplement composition to optimise nutritional interventions in malnourished HIV patients.
Maternal mental health during pregnancy and postpartum predicts later emotional and behavioural problems in children. Even though most perinatal mental health problems begin before pregnancy, the consequences of preconception maternal mental health for children's early emotional development have not been prospectively studied.
We used data from two prospective Australian intergenerational cohorts, with 756 women assessed repeatedly for mental health problems before pregnancy between age 13 and 29 years, and during pregnancy and at 1 year postpartum for 1231 subsequent pregnancies. Offspring infant emotional reactivity, an early indicator of differential sensitivity denoting increased risk of emotional problems under adversity, was assessed at 1 year postpartum.
Thirty-seven percent of infants born to mothers with persistent preconception mental health problems were categorised as high in emotional reactivity, compared to 23% born to mothers without preconception history (adjusted OR 2.1, 95% CI 1.4–3.1). Ante- and postnatal maternal depressive symptoms were similarly associated with infant emotional reactivity, but these perinatal associations reduced somewhat after adjustment for prior exposure. Causal mediation analysis further showed that 88% of the preconception risk was a direct effect, not mediated by perinatal exposure.
Maternal preconception mental health problems predict infant emotional reactivity, independently of maternal perinatal mental health; while associations between perinatal depressive symptoms and infant reactivity are partially explained by prior exposure. Findings suggest that processes shaping early vulnerability for later mental disorders arise well before conception. There is an emerging case for expanding developmental theories and trialling preventive interventions in the years before pregnancy.
Our pilot study evaluated the feasibility, effectiveness, and implementation of a group-based lifestyle-integrated functional exercise (Mi-LiFE) program for older adults in an interprofessional primary care practice. A physical therapist taught participants how to integrate strength and balance activities into daily routines during one individual and four group sessions, and two follow-up phone calls. Feasibility outcomes were recruitment, adherence, and retention over 6 months. Physical activity (PA) (accelerometer, International Physical Activity Questionnaire [IPAQ]), Short Physical Performance Battery (SPPB), and health-related quality of life (EuroQol Five-Dimensional Questionnaire with 3 Levels [EQ5D-3L]) were evaluated at baseline and 6 months. Of the 123 eligible individuals, 39 per cent participated and 61 per cent were not interested or unreachable. Forty-eight participants (mean ± standard deviation [SD] age = 81 ± 5 years; body mass index [BMI] = 28 ± 5 kg/m2; 60% women; moderate-to-vigorous PA = 49 ± 87 minutes/week) enrolled. Four participants withdrew prior to intervention. Thirty-two participants (67%) were retained at follow-up. Daily diary-documented adherence was 50 per cent at 6 months, and 77 per cent attended more than four sessions. No statistically significant changes in moderate-to-vigorous PA and SPPB outcomes were observed; yet self-reported strength and balance PA and quality of life significantly improved at follow-up. The Mi-LiFE program is feasible with acceptable recruitment and attendance rates alongside modifications to address retention and adherence challenges. These findings inform the feasibility of future pragmatic exercise programs in primary care for older adults.
In this study, we explored the effects of mentor and mentee insecure attachment dispositions (ambivalence and avoidance) on mentoring relationship quality while considering the specific nature of the interactive mentoring context. Participants (N = 252 matches) were enrolled in the MIRES program, a one-year college-based mentoring program that matches late adolescent mentees (17-year-olds) with young adult mentors (23-year-olds), designed to facilitate the transition to college. Using data drawn from mentors’ logbooks (at nine time points), two interactive contexts were addressed: (1) situations involving mentee academic issues and mentor proactive academic support (academically oriented), and (2) situations involving mentee personal issues and mentor emotional support, and caring (emotionally oriented). Linear regression results showed that both mentors’ and mentees’ avoidance uniquely predicted lower reports of mentoring relationship quality, but especially in emotionally oriented matches and when their partners’ attachment ambivalence was high. In matches less focused on emotional support, mentors’ attachment avoidance interacted with mentees’ ambivalence to predict positive mentoring relationship quality. Theoretical, practical, and mentor training issues are discussed.
Manganese nodules obtained from the ocean bottom are a vast potential source of minerals. These nodules, whose composition depend on their source, have an average composition of about 20% manganese, 14% iron, and 0.5% each of cobalt, nickel, and copper.
X-ray spectroscopy was investigated as a method for the analysis of the nodules, and analytical control during the process of extracting and recovering the minerals.
The basic borax fusion technique of Fernand Claisse (R. P, No. 327, Department of Mines, Quebec) was used. The influence of matrix elements was determined and corrections applied. The binary systems in borax were compared with the curves calculated from pure metals using the methods and calculations of Beattie and Brissey.
The results indicate that the fusion method is sufficiently rapid and accurate for use in the control analysis of manganese nodules.
Tools applied at the point of care can provide valuable prognostic information for practitioners. In this one-year, prospective observational study, we examined the association of the short performance physical battery (SPPB) and one-year emergency department (ED) visits and hospitalizations. Overall, 191 new referrals attending an outpatient geriatric clinic in Hamilton, Ontario, were approached, and 120 were enrolled. SPPB and other assessments were completed during the routine clinical visit. ED visits and hospitalizations within one year of the baseline assessment were abstracted from electronic medical records. Logistic regression analyses were used to determine ED visits and hospitalization predictors. The mean SPPB score in the study cohort (mean age 80.6, SD 6.3 years; 53% female) was 6.3 (SD 3.2). SPPB score was associated with a one-year ED visit (OR = 0.90 [0.78–1.03]) and hospitalization (OR = 0.84 [0.72–0.97]) after adjusting for age, sex, and co-morbidities.
Rare copy number variants (CNVs) are associated with risk of neurodevelopmental disorders characterised by varying degrees of cognitive impairment, including schizophrenia, autism spectrum disorder and intellectual disability. However, the effects of many individual CNVs in carriers without neurodevelopmental disorders are not yet fully understood, and little is known about the effects of reciprocal copy number changes of known pathogenic loci.
We aimed to analyse the effect of CNV carrier status on cognitive performance and measures of occupational and social outcomes in unaffected individuals from the UK Biobank.
We called CNVs in the full UK Biobank sample and analysed data from 420 247 individuals who passed CNV quality control, reported White British or Irish ancestry and were not diagnosed with neurodevelopmental disorders. We analysed 33 pathogenic CNVs, including their reciprocal deletions/duplications, for association with seven cognitive tests and four general measures of functioning: academic qualifications, occupation, household income and Townsend Deprivation Index.
Most CNVs (24 out of 33) were associated with reduced performance on at least one cognitive test or measure of functioning. The changes on the cognitive tests were modest (average reduction of 0.13 s.d.) but varied markedly between CNVs. All 12 schizophrenia-associated CNVs were associated with significant impairments on measures of functioning.
CNVs implicated in neurodevelopmental disorders, including schizophrenia, are associated with cognitive deficits, even among unaffected individuals. These deficits may be subtle but CNV carriers have significant disadvantages in educational attainment and ability to earn income in adult life.
Objective: To summarize the findings of randomized controlled trials (RCTs) on the efficacy and safety of vitamins and minerals for migraine prophylaxis. Methods: We systematically searched bibliographic databases and relevant websites for parallel and crossover RCTs reporting efficacy and/or safety of vitamins and/or minerals for migraine prophylaxis. Our primary outcomes were migraine frequency (number of attacks) and duration (hours). Secondary outcomes were severity (intensity), days with migraine, and adverse events. Meta-analysis was conducted when analyzable data were available from at least two trials. Results: Eighteen placebo-controlled trials met our eligibility criteria. Only coenzyme Q10 and magnesium contributed to meta-analyses. In adults, compared with placebo, coenzyme Q10 did not significantly decrease migraine frequency (mean difference (MD) −0.44 (−2.14 to 1.26); I2 53%; 2 trials; 97 participants; moderate strength of the evidence), duration (MD −1.97 (−4.82 to 0.87); I2 0%; 2 trials; 97 participants; moderate strength of the evidence), or severity (ratio of means (RoM) −0.05 (−0.20 to 0.11); I2 0%; 2 trials; 97 participants). In adults, compared with placebo, magnesium did not significantly decrease migraine severity (RoM −0.17 (−0.36 to 0.02); I2 48%; 3 trials; 226 participants; low strength of the evidence). Meta-analysis of other vitamins and minerals, and other outcomes were not feasible due to a lack of sufficiently reported data. Conclusions: Based on insufficient evidence, it is unknown if coenzyme Q10 and magnesium are effective for migraine prophylaxis in adults. High-quality, adequately powered RCTs are needed to fully evaluate the efficacy and safety of vitamins and minerals for migraine prophylaxis.