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This textbook offers a detailed and uniquely self-contained presentation of quantum and gauge field theories. Writing from a modern perspective, the author begins with a discussion of advanced dynamics and special relativity before guiding students steadily through the fundamental principles of relativistic quantum mechanics and classical field theory. This foundation is then used to develop the full theoretical framework of quantum and gauge field theories. The introductory, opening half of the book allows it to be used for a variety of courses, from advanced undergraduate to graduate level, and students lacking a formal background in more elementary topics will benefit greatly from this approach. Williams provides full derivations wherever possible and adopts a pedagogical tone without sacrificing rigour. Worked examples are included throughout the text and end-of-chapter problems help students to reinforce key concepts. A fully worked solutions manual is available online for instructors.
Morningglories (Ipomoea spp.) are among the most troublesome weeds in cucurbits in the United States; however, little is known about Ipomoea spp. interference with horticultural crops. Two additive design field studies were conducted in 2020 at two locations in Indiana to investigate the interference of ivyleaf morningglory (Ipomoea hederacea L.) and pitted morningglory (Ipomoea lacunose L.) with triploid watermelon Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]. Immediately after transplanting watermelon, Ipomoea spp. seedlings were transplanted into the watermelon planting holes at densities of 0 (weed-free control), 3, 6, 12, 18, and 24 per 27 m2. Fruit was harvested once a week for four weeks, and each fruit was classified as marketable (≥ 4 kg) or non-marketable (<4 kg). One week after the final harvest, aboveground biomass samples were collected from 1 m2 per plot and oven-dried to obtain watermelon and Ipomoea spp. dry weight. Seed capsules and the number of seeds in 15 capsules were counted from the biomass sample to estimate seed production. Ipomoea spp. densities increasing from 3 to 24 per 27 m2 increased marketable watermelon yield loss from 58 to 99%, reduced marketable watermelon fruit number 49 to 98%, reduced individual watermelon fruit weight 17 to 45%, and reduced watermelon aboveground biomass 83 to 94%. Ipomoea spp. seed production ranged from 549 to 7,746 seeds m-2, greatly increasing the weed seed bank. Ipomoea spp. hindered harvest due to their vines wrapping around watermelon fruits. The most likely reason for watermelon yield loss was interference with light and consequently less dry matter being partitioned into fruit development due to less photosynthesis. Yield loss was attributed to fewer fruit and the weight of each fruit.
In a randomized trial, adjunctive ultraviolet-C light treatment with a room decontamination device and sodium hypochlorite delivered via an electrostatic sprayer were similarly effective in significantly reducing residual healthcare-associated pathogen contamination on floors and high-touch surfaces after manual cleaning and disinfection. Less time until the room was ready to be occupied by another patient was required for electrostatic spraying.
We describe COVID-19 cases among nonphysician healthcare personnel (HCP) by work location. The proportion of HCP with coronavirus disease 2019 (COVID-19) was highest in the emergency department and lowest among those working remotely. COVID-19 and non–COVID-19 units had similar proportions of HCP with COVID-19 (13%). Cases decreased across all work locations following COVID-19 vaccination.
Background: Idiopathic Normal Pressure Hydrocephalus (iNPH) is a disorder of the elderly with progressive worsening of gait and balance, cognition, and urinary control which requires assessment using criteria recommended by International iNPH guidelines. Methods: Adult Hydrocephalus Clinical Research Network (AHCRN) prospective registry data from 5-centers over a 50-month interval included entry criteria; demographics; comorbidities; examination findings using standard AHCRN gait and neuropsychology assessments; shunt procedures, complications of CSF drainage, complications within 30 days of surgery, and 1-year postoperative follow-up. Results: 547 patients were referred for assessment of suspected-iNPH. 123 patients(21.6%) did not meet clinical criteria to proceed with further testing. 424 patients(74.4%;mean age 76.7 ± 6.0 years;males=269) underwent an LP or lumbar drain, and 193(45.6%) underwent insertion of a ventriculoperitoneal shunt. By 8-12 months after shunt surgery, gait velocity was 0.96±0.35m/s (54% faster than pre-CSF-drainage). Mean MoCA scores increased from 21.0 ± 5.0(median=22.0) at baseline to 22.6±5.5(median=24) 12-months post-surgery. Gait and cognitive improvements were clinically significant. No deaths occurred. 8% of shunt-surgery patients experienced minor complications. The 30-day reoperation rate was 4.1%. Conclusions: This AHCRN study demonstrated that CSF-drainage testing of patients with suspected-iNPH successfully identified those who could undergo CSF-shunt surgery with a high rate of improvement and a low rate of complications.
Over the last 25 years, radiowave detection of neutrino-generated signals, using cold polar ice as the neutrino target, has emerged as perhaps the most promising technique for detection of extragalactic ultra-high energy neutrinos (corresponding to neutrino energies in excess of 0.01 Joules, or 1017 electron volts). During the summer of 2021 and in tandem with the initial deployment of the Radio Neutrino Observatory in Greenland (RNO-G), we conducted radioglaciological measurements at Summit Station, Greenland to refine our understanding of the ice target. We report the result of one such measurement, the radio-frequency electric field attenuation length $L_\alpha$. We find an approximately linear dependence of $L_\alpha$ on frequency with the best fit of the average field attenuation for the upper 1500 m of ice: $\langle L_\alpha \rangle = ( ( 1154 \pm 121) - ( 0.81 \pm 0.14) \, ( \nu /{\rm MHz}) ) \,{\rm m}$ for frequencies ν ∈ [145 − 350] MHz.
How can researchers study magic without destroying its mystery? Drawing on a collaborative project between the playwright Poppy Corbett, the poet Anna Kisby Compton, and the historian William G. Pooley, this Element presents thirteen tools for creative-academic research into magic, illustrated through case studies from France (1790–1940) and examples from creative outputs: write to discover; borrow forms; use the whole page; play with footnotes; erase the sources; write short; accumulate fragments; re-enact; improvise; use dialogue; change perspective; make methods of metaphors; use props. These tools are ways to 'untell' the dominant narratives that shape stereotypes of the 'witch' which frame belief in witchcraft as ignorant and outdated. Writing differently suggests ways to think and feel differently, to stay with the magic, rather than explaining it away. The Element includes practical creative exercises to try as well as research materials from French newspaper and trial sources from the period.
Although reductionistic studies of mechanisms of learning in a broad range of model species have advanced our understanding of neural mechanisms, our integrated understanding of mechanisms, behavior, ecology, and evolution of learning remains patchy. A more wholistic research approach in a model lineage of species related to the sea hare, Aplysia californica, has revealed a complete loss of mechanisms of sensitization in one sea-hare genus, Dolabrifera, with concomitant changes in its behavior and ecology. A partial loss of sensitization via different mechanisms in a sister genus, Phyllaplysia, provides further information for our evolving understanding of the evolution of learning and memory. Does a relatively specific “change in diet” hypothesis, or a more universal “generalist versus specialist” hypothesis better predict the patterns? Further analyses of sensitization in a half-dozen additional sea-hare genera will distinguish the predictive powers of these and other synthetic evolutionary theories.
Nearly one in five children with CHD is born with white matter injury that can be recognised on postnatal MRI by the presence of T1 hyperintense lesions. This pattern of white matter injury is known to portend poor neurodevelopmental outcomes, but the exact aetiology and histologic characterisation of these lesions have never been described. A fetal sheep was cannulated at gestational age 110 days onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid environment for 14.5 days. The fetus was supported under hypoxic conditions (mean oxygen delivery 16 ml/kg/day) to simulate the in utero conditions of CHD. At necropsy, the brain was fixed, imaged with MRI, and then stained to histologically identify areas of injury. Under hypoxemic in utero conditions, the fetus developed a T1 hyperintense lesion in its right frontal lobe. Histologically, this lesion was characterised by microvascular proliferation and astrocytosis without gliosis. These findings may provide valuable insight into the aetiology of white matter injury in neonates with CHD.
OBJECTIVES/GOALS: To test whether implementing DASH-aligned meals in a congregate meal program, combined with Self-Measured Blood Pressure (SMBP) monitoring, lowers systolic blood pressure in community-living seniors at two senior centers. Secondary Aims included cognitive and behavioral change, and attention to client preferences. METHODS/STUDY POPULATION: The Carter Burden Network (CBN) provides services and congregate meals to older adults in NYC, many with low income, and unmet health needs. Eligible participants at two CBN sites, aged 60 or older and consuming >4 congregate meals/week, were recruited. After baseline assessments, participants received DASH-aligned meals onsite, education on nutrition and BP management, and personal devices and support for self-measured blood pressure (SMBP) monitoring. Primary outcome data (BP measured by health professional) was collected at Month 1, with secondary assessments at Months 3 and 6. Staff downloaded SMBP data regularly. Study surveys tracked cognitive and behavioral changes. Qualitative feedback from a project Advisory Committee, participants and study partners was collected throughout implementation. RESULTS/ANTICIPATED RESULTS: 97 Participants enrolled (49% White, 32% Black, 19% Other races; mean age 73). At Baseline, 67% were overweight/obese; 80% were hypertensive (32% Stage I; 48% Stage 2). Primary outcome: Mean change in systolic BP at Month 1 compared to Baseline, was -4.41 mmHg (n= 61; p=0.07). By multiple regression analysis, change in BP at Month 1 was associated with BMI, age, and baseline blood pressure (p= .02, .04, .00, respectively). SMBP: Mean change in systolic SMBP by End-of-Study was -6.9 mmHg (p=.003). 56% participants completed SMBP through Month 1 and 30% to End-of-Study. Mean frequency of > 1 SMBP measure/day was 3 days/week. Women (n= 22, 88%) and Black participants (n= 15, 60%) were more likely to continue taking their home blood pressure measurements to End-of-Study (p=.002, p=.037, respectively). DISCUSSION/SIGNIFICANCE: This study provides the first data to support the potential of DASH as part of an effective community-implemented program for seniors and demonstrates the feasibility of implementing a multi-component intervention using existing congregate meal programs at senior centers that can reach minority and low-income communities.
Recent efforts to improve attitudes toward outgroups and reduce support for extremists in violent settings report mixed results. Donors and aid organizations have spent millions of dollars to amplify the voices of moderate religious figures to counter violent extremism in West Africa, the Middle East, and South Asia. Despite this investment, we know little about whether such messaging persuades the primary recruits of violent extremist organizations: at-risk youth in fragile settings. In this paper, we consider whether pro-peace religious messaging can promote social cohesion among school-age respondents in Burkina Faso. Using a survey experiment, we find little evidence that such messages affect reported attitudes or behaviors toward religious extremism and find instead that it can have the unintended effect of increasing intolerance toward ethnic others. Our findings carry lessons about the inadvertent priming of ethnic identities that can result in a backlash effect among certain societal segments.
Advocates of the Green Revolution for Africa (GR4A) argue that the best way to address malnutrition is to incorporate smallholders into the global food economy via value chains involving the use of improved inputs, production technologies, and access to markets. Moseley and Ouedraogo critically assess these tactics using a feminist political ecology lens to analyze GR4A efforts in southwestern Burkina Faso which target female rice farmers. They examine the nature of the GR4A rice value chain, the degree to which a GR4A project is impacting the nutrition of participating women, and the influence of gender roles on GR4A rice project outcomes.
To describe the association between duration of antimicrobial prophylaxis (AMP) and 30-day surgical site infection (SSI), 7-day acute kidney injury (AKI), 90-day Clostridioides difficile infection (CDI), prolonged hospitalization, and 30-day reoperation after lumbar spine surgery for noninfectious indications, and to report adherence to current guidelines.
Design:
Survey.
Participants and setting:
The study cohort comprised 6,198 patients who underwent lumbar spine surgery for noninfectious indications across 137 Veterans’ Health Administration surgery centers between 2016 and 2020.
Methods:
Used univariate and multivariate logistic regression to determine the association between type and duration of AMP with 30-day SSI, 7-day AKI, 90-day CDI, prolonged hospitalization, and 30-day reoperation.
Results:
Only 1,160 participants (18.7%) received the recommended duration of AMP. On multivariate analysis, the use of multiple prophylactic antimicrobials was associated with increased odds of 90-day CDI (adjusted odds ratio [aOR], 5.5; 95% confidence interval [CI], 1.1–28.2) and 30-day reoperation (aOR, 2.3; 95% CI, 1.2–4.4). Courses of antimicrobials ≥3 days were associated with increased odds of prolonged hospitalization (aOR,1.8; 95% CI, 1.4–2.3) and 30-day reoperation (aOR, 3.5; 95% CI, 2.2–5.7). In univariate analysis, increasing days of AMP was associated with a trend toward increasing odds of 90-day CDI (cOR, 1.4; 95% CI, 1.0–1.8 per additional day; P = .056).
Conclusions:
Longer courses of AMP after lumbar spine surgery were associated with higher odds of CDI, prolonged hospitalization, and reoperation, but not with lower odds of SSI. However, adherence to the recommended duration of AMP is very low, hinting at a wide evidence-to-practice gap that needs to be addressed by spine surgeons and antimicrobial stewardship programs.
Contrasting the well-described effects of early intervention (EI) services for youth-onset psychosis, the potential benefits of the intervention for adult-onset psychosis are uncertain. This paper aims to examine the effectiveness of EI on functioning and symptomatic improvement in adult-onset psychosis, and the optimal duration of the intervention.
Methods
360 psychosis patients aged 26–55 years were randomized to receive either standard care (SC, n = 120), or case management for two (2-year EI, n = 120) or 4 years (4-year EI, n = 120) in a 4-year rater-masked, parallel-group, superiority, randomized controlled trial of treatment effectiveness (Clinicaltrials.gov: NCT00919620). Primary (i.e. social and occupational functioning) and secondary outcomes (i.e. positive and negative symptoms, and quality of life) were assessed at baseline, 6-month, and yearly for 4 years.
Results
Compared with SC, patients with 4-year EI had better Role Functioning Scale (RFS) immediate [interaction estimate = 0.008, 95% confidence interval (CI) = 0.001–0.014, p = 0.02] and extended social network (interaction estimate = 0.011, 95% CI = 0.004–0.018, p = 0.003) scores. Specifically, these improvements were observed in the first 2 years. Compared with the 2-year EI group, the 4-year EI group had better RFS total (p = 0.01), immediate (p = 0.01), and extended social network (p = 0.05) scores at the fourth year. Meanwhile, the 4-year (p = 0.02) and 2-year EI (p = 0.004) group had less severe symptoms than the SC group at the first year.
Conclusions
Specialized EI treatment for psychosis patients aged 26–55 should be provided for at least the initial 2 years of illness. Further treatment up to 4 years confers little benefits in this age range over the course of the study.
Gatherings where people are eating and drinking can increase the risk of getting and spreading SARS-CoV-2 among people who are not fully vaccinated; prevention strategies like wearing masks and physical distancing continue to be important for some groups. We conducted an online survey to characterise fall/winter 2020–2021 holiday gatherings, decisions to attend and prevention strategies employed during and before gatherings. We determined associations between practicing prevention strategies, demographics and COVID-19 experience. Among 502 respondents, one-third attended in person holiday gatherings; 73% wore masks and 84% practiced physical distancing, but less did so always (29% and 23%, respectively). Younger adults were 44% more likely to attend gatherings than adults ≥35 years. Younger adults (adjusted prevalence ratio (aPR) 1.53, 95% CI 1.19–1.97), persons who did not experience COVID-19 themselves or have relatives/close friends experience severe COVID-19 (aPR 1.56, 95% CI 1.18–2.07), and non-Hispanic White persons (aPR 1.57, 95% CI 1.13–2.18) were more likely to not always wear masks in public during the 2 weeks before gatherings. Public health messaging emphasizing consistent application of COVID-19 prevention strategies is important to slow the spread of COVID-19.
Many short gamma-ray bursts (GRBs) originate from binary neutron star mergers, and there are several theories that predict the production of coherent, prompt radio signals either prior, during, or shortly following the merger, as well as persistent pulsar-like emission from the spin-down of a magnetar remnant. Here we present a low frequency (170–200 MHz) search for coherent radio emission associated with nine short GRBs detected by the Swift and/or Fermi satellites using the Murchison Widefield Array (MWA) rapid-response observing mode. The MWA began observing these events within 30–60 s of their high-energy detection, enabling us to capture any dispersion delayed signals emitted by short GRBs for a typical range of redshifts. We conducted transient searches at the GRB positions on timescales of 5 s, 30 s, and 2 min, resulting in the most constraining flux density limits on any associated transient of 0.42, 0.29, and 0.084 Jy, respectively. We also searched for dispersed signals at a temporal and spectral resolution of 0.5 s and 1.28 MHz, but none were detected. However, the fluence limit of 80–100 Jy ms derived for GRB 190627A is the most stringent to date for a short GRB. Assuming the formation of a stable magnetar for this GRB, we compared the fluence and persistent emission limits to short GRB coherent emission models, placing constraints on key parameters including the radio emission efficiency of the nearly merged neutron stars (
$\epsilon_r\lesssim10^{-4}$
), the fraction of magnetic energy in the GRB jet (
$\epsilon_B\lesssim2\times10^{-4}$
), and the radio emission efficiency of the magnetar remnant (
$\epsilon_r\lesssim10^{-3}$
). Comparing the limits derived for our full GRB sample (along with those in the literature) to the same emission models, we demonstrate that our fluence limits only place weak constraints on the prompt emission predicted from the interaction between the relativistic GRB jet and the interstellar medium for a subset of magnetar parameters. However, the 30-min flux density limits were sensitive enough to theoretically detect the persistent radio emission from magnetar remnants up to a redshift of
$z\sim0.6$
. Our non-detection of this emission could imply that some GRBs in the sample were not genuinely short or did not result from a binary neutron star merger, the GRBs were at high redshifts, these mergers formed atypical magnetars, the radiation beams of the magnetar remnants were pointing away from Earth, or the majority did not form magnetars but rather collapse directly into black holes.
This study presents computational simulations of multicomponent and multiphase flows to reproduce the physical phenomena in the secondary atomization of a droplet induced by a hot temperature environment. The computational fluid dynamics model is based on the geometric volume of fluid method, with piecewise linear interface calculation reconstruction for accurate determination of the curvature and evaporation fluxes at the interface. The purpose of the model was to faithfully reproduce complex physical processes, such as internal gas cavity formation, liquid–vapour interface instability, cavity collapse and liquid jet ejection, and the pinch-off of a secondary droplet, leading to the microexplosion phenomenon that greatly enhances the evaporation rate of non-volatile liquid droplets. The solver was validated against the analytical solution in benchmark cases, and experimental data with bicomponent droplets reported in the literature. The developed model was used to predict the atomization of heavy fuel oil exposed at high temperatures under microgravity conditions. Different atomization regimes were identified, depending on the initial size of the internal bubbles. While small bubbles led to simple gas ejections, cavity collapse caused the larger bubbles to produce a jet formation. When the ratio between the bubble and droplet volumes was bigger than 0.7, microexplosions occurred. The results were found to be consistent with cases of bubble burst on flat surfaces, showing a strong dependence on the Ohnesorge number ($Oh$). Key observable quantities, particularly jet velocity and bubble cap drainage velocity, were found to agree with correlations reported in other studies. The similarities were also supported by studies extending over a wide range of simulations (4000 cases) at different $Oh$. An inversion in the dependence of the jet velocity on $Oh$ (above a critical value $Oh_c$) was observed.
Sweet corn (Zea mays L.) tolerance to dicamba and several other herbicides is due to cytochrome P450 (CYP)-mediated metabolism and is conferred by a single gene (Nsf1). Tolerance varies by CYP genotypic class, with hybrids homozygous for functional CYP (Nsf1Nsf1) being the most tolerant and hybrids homozygous for mutant CYP alleles (nsf1nsf1) being the least tolerant. The herbicide safener cyprosulfamide (CSA) increases tolerance to dicamba by stimulating the expression of several CYPs. However, the extent to which CSA improves the tolerance of different sweet corn CYP genotypic classes to dicamba is poorly understood. Additionally, the effect of growth stage on sweet corn sensitivity to dicamba is inadequately described. The objective of this work was to quantify the significance of application timing, formulation, and CYP genotypic class on sweet corn response to dicamba. Hybrids representing each of the three CYP genotypes (Nsf1Nsf1, Nsf1nsf1, nsf1nsf1), were treated with dicamba or dicamba + CSA at one of three growth stages: V3, V6, or V9. Across all timings, the nsf1nsf1 hybrid was the least tolerant to dicamba, displaying 16% higher crop injury levels 2 wk after treatment and 2,130 kg ha−1 lower ear mass yields compared with the Nsf1Nsf1 hybrid. The V9 growth stage was the most susceptible time for dicamba injury regardless of genotypic class, with 1.89 and 1,750 kg ha−1 lower ear mass yields compared with the V3 and V6 application timings, respectively. The addition of CSA to dicamba V9 applications reduced the injury from dicamba for all three genotypic classes; however, it did not eliminate the injury. The use of Nsf1Nsf1 or Nsf1nsf1 sweet corn hybrids along with herbicide safeners will reduce the frequency and severity of injury from dicamba and other CYP-metabolized herbicides.