To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Weed management is a major challenge in organic crop production, and organic farms generally harbor larger weed populations and more diverse communities compared with conventional farms. However, little research has been conducted on the effects of different organic management practices on weed communities and crop yields. In 2014 and 2015, we measured weed community structure and soybean [Glycine max (L.) Merr.] yield in a long-term experiment that compared four organic cropping systems that differed in nutrient inputs, tillage, and weed management intensity: (i) High Fertility (HF), (ii) Low Fertility (LF), (iii) Enhanced Weed Management (EWM), and (iv) Reduced Tillage (RT). In addition, we created Weed Free sub-plots within each system in order to assess the impact of weeds on soybean yield. Weed density was greater in the LF and RT systems compared with the EWM system, but weed biomass did not differ among systems. Weed species richness was greater in the RT system compared with the EWM system, and weed community composition differed between RT and other systems. Our results show that differences in weed community structure were primarily related to differences in tillage intensity, rather than nutrient inputs. Soybean yield was lower in the EWM system compared with the HF and RT systems. When averaged across all four cropping systems and both years, soybean yield in Weed Free sub-plots was 10% greater than soybean yield in the Ambient Weed sub-plots that received standard management practices of the system in which they were located. Although weed competition limited soybean yield across all systems, the EWM system which had the lowest weed density also had the lowest soybean yield. Future research should aim to overcome such tradeoffs between weed control and yield potential, while conserving weed species richness and the ecosystem services associated with increased weed diversity.
There is a long history of exploitation of the South American river turtle Podocnemis expansa. Conservation efforts for this species started in the 1960s but best practices were not established, and population trends and the number of nesting females protected remained unknown. In 2014 we formed a working group to discuss conservation strategies and to compile population data across the species’ range. We analysed the spatial pattern of its abundance in relation to human and natural factors using multiple regression analyses. We found that > 85 conservation programmes are protecting 147,000 nesting females, primarily in Brazil. The top six sites harbour > 100,000 females and should be prioritized for conservation action. Abundance declines with latitude and we found no evidence of human pressure on current turtle abundance patterns. It is presently not possible to estimate the global population trend because the species is not monitored continuously across the Amazon basin. The number of females is increasing at some localities and decreasing at others. However, the current size of the protected population is well below the historical population size estimated from past levels of human consumption, which demonstrates the need for concerted global conservation action. The data and management recommendations compiled here provide the basis for a regional monitoring programme among South American countries.
Determining infectious cross-transmission events in healthcare settings involves manual surveillance of case clusters by infection control personnel, followed by strain typing of clinical/environmental isolates suspected in said clusters. Recent advances in genomic sequencing and cloud computing now allow for the rapid molecular typing of infecting isolates.
To facilitate rapid recognition of transmission clusters, we aimed to assess infection control surveillance using whole-genome sequencing (WGS) of microbial pathogens to identify cross-transmission events for epidemiologic review.
Clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, and Klebsiella pneumoniae were obtained prospectively at an academic medical center, from September 1, 2016, to September 30, 2017. Isolate genomes were sequenced, followed by single-nucleotide variant analysis; a cloud-computing platform was used for whole-genome sequence analysis and cluster identification.
Most strains of the 4 studied pathogens were unrelated, and 34 potential transmission clusters were present. The characteristics of the potential clusters were complex and likely not identifiable by traditional surveillance alone. Notably, only 1 cluster had been suspected by routine manual surveillance.
Our work supports the assertion that integration of genomic and clinical epidemiologic data can augment infection control surveillance for both the identification of cross-transmission events and the inclusion of missed and exclusion of misidentified outbreaks (ie, false alarms). The integration of clinical data is essential to prioritize suspect clusters for investigation, and for existing infections, a timely review of both the clinical and WGS results can hold promise to reduce HAIs. A richer understanding of cross-transmission events within healthcare settings will require the expansion of current surveillance approaches.
X-ray Microfluorescence (XRMF) analysis uses a finely collimated beam of X-rays to excite fluorescent radiation in a sample (Nichols & Ryon 1986). Characteristic fluorescent radiation emanating from the small interaction volume element is acquired using an energy dispersive detector placed in close proximity to the sample. The signal from the detector is processed using a computer-based multi-channel analyzer.
XRMF imaging is accomplished by translating the sample through the small X-ray beam in a step or continuous raster mode. As the sample is translated, a pixel by pixel X-ray intensity image is formed for each chemical element in the sample. The resulting digitized image information for each element is stored for subsequent processing and/or display. The images, in the form of elemental maps representing identical areas, may be displayed and color coded by element and/or intensity and then overlayed for spatial correlation.
The present study of parameters affecting the performance of an X-ray microfluorescence system has shown how such systems use X-ray beams with effective spot sizes less than 100 micrometers to bridge the gap in analytical capabilities between predominately surface micro analytical techniques such as SEM/EDX and bulk analytical methods such as standard XRF analysis. The combination of XRMF spectroscopy with digital imaging allows chemical information to be obtained and mapped from surface layers as well as from layers or structures beneath the sample surface. Simultaneously, it provides valuable high resolution chemical information in a readily interpreted visual form which displays the homogeneity within a given layer or structure. XRMF systems retain the advantages of minimal sample preparation, non-destructive analysis and high sensitivity inherent to XRF methods.
In the last decade, the Fundamental Parameter (FT) method has been increasingly used in quantitative XRF analysis as an effective means for interelement effect corrections. Many authors have contributed to its continuous development both in theory and practice [1 - 26]. Among various implementations, the FP-alpha method has been used widely in bulk-sample analysis because of its unique advantage of speed [1 - 6]. In recent years, however, with the advent of faster computers, a rigorous full FP approach has become feasible and practical. This is especially true in the field of multilayer thin-film, analysis, where the FP-alpha approach has not yet been applied.
Syndromic surveillance is a form of surveillance that generates information for public health action by collecting, analysing and interpreting routine health-related data on symptoms and clinical signs reported by patients and clinicians rather than being based on microbiologically or clinically confirmed cases. In England, a suite of national real-time syndromic surveillance systems (SSS) have been developed over the last 20 years, utilising data from a variety of health care settings (a telehealth triage system, general practice and emergency departments). The real-time systems in England have been used for early detection (e.g. seasonal influenza), for situational awareness (e.g. describing the size and demographics of the impact of a heatwave) and for reassurance of lack of impact on population health of mass gatherings (e.g. the London 2012 Olympic and Paralympic Games).We highlight the lessons learnt from running SSS, for nearly two decades, and propose questions and issues still to be addressed. We feel that syndromic surveillance is an example of the use of ‘big data’, but contend that the focus for sustainable and useful systems should be on the added value of such systems and the importance of people working together to maximise the value for the public health of syndromic surveillance services.
Informal (unpaid) care-givers of older people with dementia experience stress and isolation, causing physical and psychiatric morbidity. Comprehensive geriatric assessment clinics represent an important geriatrician-led model of dementia care. Our qualitative study examined the educational and support needs of care-givers of people diagnosed with dementia at a geriatric assessment clinic, resources used to address those needs and challenges experienced in doing so. We conducted structured thematic analysis of interviews with 18 informal care-givers. Participants’ narratives reflected four themes. First, care-givers sought information from varied sources, including the Alzheimer Society, the internet and clinic staff. Responsive behaviours, the expected progression of dementia and system navigation were topics of particular interest. Second, care-givers obtained assistance from public, for-profit and voluntary sources. Third, care-givers received little assistance. Two-thirds received fewer than four hours of help weekly from all sources combined, and none more than 15. Several received no assistance whatsoever. Publicly funded support workers’ tasks, and their timing, were often unhelpful. Finally, while numerous care-givers felt physical and emotional strain, and worried about how poor health impaired their care-giving, many hesitated to seek help. The needs of this unique population of informal care-givers can be met by improved home-care service flexibility, and access to trustworthy information about the expected progression of dementia and skills for managing behavioural and psychological symptoms.
OBJECTIVES/SPECIFIC AIMS: (1) To evaluate clinical outcomes in mechanically ventilated patients with and without fever. We hypothesize that, after adjusting for confounding factors such as age and severity of illness: (a) In septic patients, fever will be associated with improved clinical outcomes. (b) In nonseptic patients, fever will be associated with worse clinical outcomes. (2) To examine the relationship between antipyretics and mortality in mechanically ventilated patients at risk for an acute lung injury. We hypothesize that antipyretics will have no effect on clinical outcomes in mechanically ventilated patients with and without sepsis. METHODS/STUDY POPULATION: This is a retrospective study of a “before and after” observational cohort of 1705 patients with acute initiation of mechanical ventilation in the Emergency Department from September 2009 to March 2016. Data were collected retrospectively on the first 72 hours of temperature and antipyretic medication from the EHR. Temperatures measurements were adjusted based on route of measurement. Patients intubated for cardiac arrest or brain injury were excluded from our primary analysis due to the known damage of hyperthermia in these subsets. Cox proportional hazard models and multivariable linear regression analyzed time-to-event and continuous outcomes, respectively. Predetermined patient demographics were entered into each multivariable model using backward and forward stepwise regression. Models were assessed for collinearity and residual plots were used to assure each model met assumptions. RESULTS/ANTICIPATED RESULTS: Antipyretic administration is currently undergoing analysis. Initial temperature results are reported here. In the overall group, presence of hypothermia or fever within 72 hours of intubation compared with normothermia conferred a hazard ratio (HR) of 1.95 (95% CI: 1.48–2.56) and 1.31 (95% CI: 0.97–1.78), respectively. Presence of hypothermia and fever reduced hospital free days by 3.29 (95% CI: 2.15–4.42) and 2.34 (95% CI: 1.21–3.46), respectively. In our subgroup analysis of patients with sepsis, HR for 28-day mortality 2.57 (95% CI: 1.68–3.93) for hypothermia. Fever had no effect on mortality (HR 1.11, 95% CI: 0.694–1.76). Both hypothermia and fever reduced hospital free days by 5.39 (95% CI: 4.33–7.54) and 3.98 (95% CI: 2.46–5.32) days, respectively. DISCUSSION/SIGNIFICANCE OF IMPACT: As expected, both hypothermia and fever increased 28-day mortality and decreased hospital free days. In our sepsis subgroup, hypothermia again resulted in higher mortality and fewer hospital free days, while fever did not have a survival benefit or cost, but reduced hospital free days. Antipyretic administration complicates these findings, as medication may mask fever or exert an effect on survival. Fever may also affect mechanically ventilated septic patients differently than septic patients not on mechanical ventilation. Continued analysis of this data including antipyretic administration, ventilator free days and progression to ARDS will address these questions.
OBJECTIVES/SPECIFIC AIMS: A brain-machine interface (BMI) is a device implanted into the brain of a paralyzed or injured patient to control an external assistive device, such as a cursor on a computer screen, a motorized wheelchair, or a robotic limb. We hypothesize we can utilize electrical stimulation of subdural electrocorticography (ECoG) electrodes as a method of generating the percepts of somatosensation such as vibration, temperature, or proprioception. METHODS/STUDY POPULATION: There will be 10 subjects, who are informed, willing, and consented epilepsy patients undergoing initial surgery for placement of subdural ECoG electrodes in the brain for seizure monitoring. ECoG will be used as a platform for recording high-resolution local field potentials during real-touch behavioral tasks. In addition, ECoG will also be used to electrically stimulate the human cerebral cortex in order to map and understand how varying stimulation parameters produce percepts of sensation. RESULTS/ANTICIPATED RESULTS: To determine how tactile and proprioceptive signals are integrated in S1, we will perform spectral analysis of the broadband local field potentials to look for increased power in specific frequency bands in the ECoG recordings while touching or moving the hand. To explore generating artificial sensation, the subject will be asked to perform a variety of tasks with and without the aid of stimulation. We anticipate the subject’s performance will be enhanced with the addition of artificial sensation. DISCUSSION/SIGNIFICANCE OF IMPACT: Many patients might benefit from a BMI, such as those with stroke, amputation, spinal cord injury, or brain trauma. The current generation of BMI devices are guided by visual feedback alone. However, without somatosensory feedback, even the most basic limb movements are difficult to perform in a fluid and natural manner. The results from this project will be crucial to developing a closed loop motor/sensory BMI.
To explore the prevalence and drivers of hospital-level variability in antibiotic utilization among hematopoietic cell transplant (HCT) recipients to inform antimicrobial stewardship initiatives.
Retrospective cohort study using data merged from the Pediatric Health Information System and the Center for International Blood and Marrow Transplant Research.
The study included 27 transplant centers in freestanding children’s hospitals.
The primary outcome was days of broad-spectrum antibiotic use in the interval from day of HCT through neutrophil engraftment. Hospital antibiotic utilization rates were reported as days of therapy (DOTs) per 1,000 neutropenic days. Negative binomial regression was used to estimate hospital utilization rates, adjusting for patient covariates including demographics, transplant characteristics, and severity of illness. To better quantify the magnitude of hospital variation and to explore hospital-level drivers in addition to patient-level drivers of variation, mixed-effects negative binomial models were also constructed.
Adjusted hospital rates of antipseudomonal antibiotic use varied from 436 to 1121 DOTs per 1,000 neutropenic days, and rates of broad-spectrum, gram-positive antibiotic use varied from 153 to 728 DOTs per 1,000 neutropenic days. We detected variability by hospital in choice of antipseudomonal agent (ie, cephalosporins, penicillins, and carbapenems), but gram-positive coverage was primarily driven by vancomycin use. Considerable center-level variability remained even after controlling for additional hospital-level factors. Antibiotic use was not strongly associated with days of significant illness or mortality.
Among a homogenous population of children undergoing HCT for acute leukemia, both the quantity and spectrum of antibiotic exposure in the immediate posttransplant period varied widely. Antimicrobial stewardship initiatives can apply these data to optimize the use of antibiotics in transplant patients.
We present the first data release of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia. Here, we present the survey strategy, data processing, catalogue construction, and database schema. The first data release dataset includes over 66 000 images from the Shallow Survey component, covering an area of 17 200 deg2 in all six SkyMapper passbands uvgriz, while the full area covered by any passband exceeds 20 000 deg2. The catalogues contain over 285 million unique astrophysical objects, complete to roughly 18 mag in all bands. We compare our griz point-source photometry with Pan-STARRS1 first data release and note an RMS scatter of 2%. The internal reproducibility of SkyMapper photometry is on the order of 1%. Astrometric precision is better than 0.2 arcsec based on comparison with Gaia first data release. We describe the end-user database, through which data are presented to the world community, and provide some illustrative science queries.
This study proposed to test the postulate that the anxiety and insomnia symptom cluster (A/I) is a predictor of dementia.
A retrospective data analysis was conducted on the Aging, Demographics, and Memory Study (ADAMS) dataset in order to determine whether A/I symptoms or treatment were associated with subsequent dementia or cognitive impairment (DOCI). The study used logistic regression analysis and comparison of incidence rates on a sample of 249 participants.
There was a significant relationship between A/I symptoms and subsequent DOCI in the male gender that was not found in the total sample or in females. No association with subsequent DOCI was found for benzodiazepine usage or non-benzodiazepine A/I medication usage.
The gender differences identified suggest prodromal dementia phenotypes that are differentially expressed in males and females. By triangulating the approaches from multiple disciplines—such as neuroimaging and genetics—with prodromalsymptoms, it is possible that reliable early prediction may be accomplished.
East Africa is a global hot spot for the diversity of ixodid ticks. As ectoparasites and as vectors of pathogens, ticks negatively affect the well-being of humans, livestock and wildlife. To prevent tick infestations, livestock owners and managers typically treat livestock with acaricides that kill ticks when they attempt to feed on livestock hosts. Because of the costs of preventing and mitigating tick parasitism, predicting where and when ticks will be abundant is an important challenge in this region. We used a 7-year monthly record of tick abundance on large experimental plots to assess the effects of rainfall, wildlife and cattle on larvae, nymphs and adults of two common tick species, Rhipicephalus pulchellus and Rhipicephalus praetextatus. Nymphal and adult ticks were more abundant when there had been high cumulative rainfall in the prior months. They were less abundant when cattle were present than when only large wild mammals were. Larval abundance was not affected by the presence of cattle, and larvae did not appear to be sensitive to rainfall in prior months, though they were less abundant in our surveys when rainfall was high in the sampling month. The challenges of managing ticks in this region are being exacerbated rapidly by changes in rainfall patterns wrought by climate change, and by overall increases in livestock, making efforts to predict the impacts of these drivers all the more pressing.
OBJECTIVES/SPECIFIC AIMS: Cervical fusion is commonly performed for the management of degenerative disc disease, which can cause spinal stenosis and radiculopathy. Adjacent segment disease (ASD) is an adverse postsurgical outcome experienced by some patients as new radiculopathy, stenosis, or other symptomatic sequelae. We sought to assess whether fusion extension past the cervicothoracic junction reduces the risk of distal ASD after multilevel fusions ending at C7-T3. METHODS/STUDY POPULATION: We retrospectively reviewed all first-time patients undergoing instrumented cervical fusion of at least 2 spinal levels and whose distal level of fusion ranged from C7-T3, at the Johns Hopkins Medical Institutions, from 1999 to 2013. The primary outcome was reoperation for distal ASD. Using multiple logistic regression, ANOVA, and χ2 analysis, we determined the odds of ASD due to age, gender, distal level of fusion, surgical approach (anterior, posterior, or combined), smoking status, and race. RESULTS/ANTICIPATED RESULTS: Of the 158 patients who met the selection criteria, the mean age was 58.7±13.8 years, and 95 (60.1%) were female. Ten patients (6.3%) underwent reoperation for ASD. Patients whose fusions ended at C7 were significantly more likely to develop ASD and undergo reoperation (70%, p=0.007) than those whose fusions ended at T1. There were no differences in age, proximal fusion level, smoking status, BMI, gender, and patient-reported race between the reoperation and non-reoperation groups. Following a multivariable analysis, extending the distal fusion to T1 was again found to be protective against reoperation (OR=0.07, p=0.020). DISCUSSION/SIGNIFICANCE OF IMPACT: Our study shows that for multilevel instrumented cervical fusions that terminate within the cervicothoracic junction, fusion distal to the C7 vertebra is associated with decreased odds of reoperation for symptomatic ASD. Therefore, this study provides clinical evidence that may help surgeons determine the optimal distal fusion segment for multilevel fusions ending at C7-T3.
Regulatory impact analyses (RIAs) weigh the benefits of regulations against the burdens they impose and are invaluable tools for informing decision makers. We offer 10 tips for nonspecialist policymakers and interested stakeholders who will be reading RIAs as consumers.
1.Core problem: Determine whether the RIA identifies the core problem (compelling public need) the regulation is intended to address.
2.Alternatives: Look for an objective, policy-neutral evaluation of the relative merits of reasonable alternatives.
3.Baseline: Check whether the RIA presents a reasonable “counterfactual” against which benefits and costs are measured.
4.Increments: Evaluate whether totals and averages obscure relevant distinctions and trade-offs.
5.Uncertainty: Recognize that all estimates involve uncertainty, and ask what effect key assumptions, data, and models have on those estimates.
6.Transparency: Look for transparency and objectivity of analytical inputs.
7.Benefits: Examine how projected benefits relate to stated objectives.
8.Costs: Understand what costs are included.
9.Distribution: Consider how benefits and costs are distributed.
10.Symmetrical treatment: Ensure that benefits and costs are presented symmetrically.
On 1 December 2011 the West Antarctic Ice Sheet (WAIS) Divide ice-core project reached its final depth of 3405 m. The WAIS Divide ice core is not only the longest US ice core to date, but is also the highest-quality deep ice core, including ice from the brittle ice zone, that the US has ever recovered. The methods used at WAIS Divide to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the US National Ice Core Laboratory (NICL) and the methods used to process and sample the ice at the NICL are described and discussed.
The diagnosis of dementia remains inadequate, even within clinical settings. Data on rates and degree of impairment among inpatients are vital for service planning and the provision of appropriate patient care as Ireland's population ages.
Every patient aged 65 years and over admitted over a two-week period was invited to participate. Those who met inclusion criteria were screened for delirium then underwent cognitive screening. Demographic, functional, and outcome data were obtained from medical records, participants, and family.
Consent to participate was obtained from 68.6% of the eligible population. Data for 143 patients were obtained. Mean age 78.1 years. 27.3% met criteria for dementia and 21% had mild cognitive impairment (MCI). Only 41% of those with dementia and 10% of those with MCI had a previously documented impairment. Between-group analysis showed differences in length of stay (p = 0.003), number of readmissions in 12 months (p = 0.036), and likelihood of returning home (p = 0.039) between the dementia and normal groups. MCI outcomes were similar to the normal group. No difference was seen for one-year mortality. Effects were less pronounced on multivariate analysis but continued to show a significant effect on length of stay even after controlling for demographics, personal and family history, and anxiety and depression screening scores. Patients with dementia remained in hospital 15.3 days longer (p = 0.047). A diagnosis is the single biggest contributing factor to length of stay in our regression model.
Cognitive impairment is pervasive and under-recognized in the acute hospital and impacts negatively on patient outcomes.
Anomalous aortic origin of the coronary arteries is associated with exercise-induced ischaemia, leading some physicians to restrict exercise in patients with this condition. We sought to determine whether exercise restriction was associated with increasing body mass index over time. From 1998 to 2015, 440 patients ⩽30 years old were enrolled into an inception cohort. Exercise-restriction status was documented in 143 patients. Using linear mixed model repeated-measures regression, factors associated with increasing body mass index z-score over time, including exercise restriction and surgical intervention as time-varying covariates, were investigated. The 143 patients attended 558 clinic visits for which exercise-restriction status was recorded. The mean number of clinic visits per patient was 4, and the median duration of follow-up was 1.7 years (interquartile range (IQR) 0.5–4.4). The median age at first clinic visit was 10.3 years (IQR 7.1–13.9), and 71% (101/143) were males. All patients were alive at their most recent follow-up. At the first clinic visit, 54% (78/143) were exercise restricted, and restriction status changed in 34% (48/143) during follow-up. The median baseline body mass index z-score was 0.2 (IQR 0.3–0.9). In repeated-measures analysis, neither time-related exercise restriction nor its interaction with time was associated with increasing body mass index z-score. Surgical intervention and its interaction with time were associated with decreasing body mass index z-score. Although exercise restriction was not associated with increasing body mass index over time, surgical intervention was associated with decreasing body mass index z-score over time in patients with anomalous aortic origin of the coronary arteries.