To save 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 saving content to .
To save 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 saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved 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.
Technological opportunities are explored to enhance detection schemes in transmission electron microscopy (TEM) that build on the detection of single-electron scattering events across the typical spectrum of interdisciplinary applications. They range from imaging with high spatiotemporal resolution to diffraction experiments at the window to quantum mechanics, where the wave-particle dualism of single electrons is evident. At the ultimate detection limit, where isolated electrons are delivered to interact with solids, we find that the beam current dominates damage processes instead of the deposited electron charge, which can be exploited to modify electron beam-induced sample alterations. The results are explained by assuming that all electron scattering are inelastic and include phonon excitation that can hardly be distinguished from elastic electron scattering. Consequently, a coherence length and a related coherence time exist that reflect the interaction of the electron with the sample and change linearly with energy loss. Phonon excitations are of small energy (<100 meV), but they occur frequently and scale with beam current in the irradiated area, which is why we can detect their contribution to beam-induced sample alterations and damage.
Barriers to research participation by racial and ethnic minority group members are multi-factorial, stem from historical social injustices and occur at participant, research team, and research process levels. The informed consent procedure is a key component of the research process and represents an opportunity to address these barriers. This manuscript describes the development of the Strengthening Translational Research in Diverse Enrollment (STRIDE) intervention, which aims to improve research participation by individuals from underrepresented groups.
We used a community-engaged approach to develop an integrated, culturally, and literacy-sensitive, multi-component intervention that addresses barriers to research participation during the informed consent process. This approach involved having Community Investigators participate in intervention development activities and using community engagement studios and other methods to get feedback from community members on intervention components.
The STRIDE intervention has three components: a simulation-based training program directed toward clinical study research assistants that emphasizes cultural competency and communication skills for assisting in the informed consent process, an electronic consent (eConsent) framework designed to improve health-related research material comprehension and relevance, and a “storytelling” intervention in which prior research participants from diverse backgrounds share their experiences delivered via video vignettes during the consent process.
The community engaged development approach resulted in a multi-component intervention that addresses known barriers to research participation and can be integrated into the consent process of research studies. Results of an ongoing study will determine its effectiveness at increasing diversity among research participants.
To examine genetic influences the anatomy of the Corpus Callosum (CC) in Bipolar Disorder (BD) by examining first-degree relatives in addition to BD patients.
We compared CCl size and shape in 180 individuals: 70 with BD, 45 of their unaffected first-degree relatives, and 75 healthy controls. The CC was extracted from a mid-sagittal slice from T1-weighted magnetic resonance images; its total area, length and curvature were compared across groups. A non-parametric permutation method was used to examine for alterations in width of the callosum along 39 points.
Validating our previous findings, a significant global reduction in CC thickness was seen in BD patients, with a disproportionate thinning in the anterior body. First-degree relatives did not differ in CC size or shape from controls. Duration of illness was associated with thinning in the anterior body, whereas Lithium treatment associated with thicker anterior CC midbody.
Global and regional CC thinning is a disease related feature of BD and may not represent a marker of familial disposition.
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.
Both maternal 25-hydroxyvitamin D (25(OH)D) concentrations during pregnancy and
placental amino acid transporter gene expression have been associated with
development of the offspring in terms of body composition and bone structure.
Several amino acid transporter genes have vitamin D response elements in their
promoters suggesting the possible linkage of these two mechanisms. We aimed to
establish whether maternal 25(OH)D and vitamin D-binding protein (VDBP) levels
relate to expression of placental amino acid transporters. RNA was extracted
from 102 placental samples collected in the Southampton Women's Survey,
and gene expression was analysed using quantitative real-time PCR. Gene
expression data were normalised to the geometric mean of three housekeeping
genes, and related to maternal factors and childhood body composition. Maternal
serum 25(OH)D and VDBP levels were measured by radioimmunoassay. Maternal
25(OH)D and VDBP levels were positively associated with placental expression of
specific genes involved in amino acid transport. Maternal 25(OH)D and VDBP
concentrations were correlated with the expression of specific placental amino
acid transporters, and thus may be involved in the regulation of amino acid
transfer to the fetus. The positive correlation of VDBP levels and placental
transporter expression suggests that delivery of vitamin D to the placenta may
be important. This exploratory study identifies placental amino acid
transporters which may be altered in response to modifiable maternal factors and
provides a basis for further studies.
On 23 May 2011, CDC identified a multistate cluster of Salmonella Heidelberg infections and two multidrug-resistant (MDR) isolates from ground turkey retail samples with indistinguishable pulsed-field gel electrophoresis patterns. We defined cases as isolation of outbreak strains in persons with illness onset between 27 February 2011 and 10 November 2011. Investigators collected hypothesis-generating questionnaires and shopper-card information. Food samples from homes and retail outlets were collected and cultured. We identified 136 cases of S. Heidelberg infection in 34 states. Shopper-card information, leftover ground turkey from a patient's home containing the outbreak strain and identical antimicrobial resistance profiles of clinical and retail samples pointed to plant A as the source. On 3 August, plant A recalled 36 million pounds of ground turkey. This outbreak increased consumer interest in MDR Salmonella infections acquired through United States-produced poultry and played a vital role in strengthening food safety policies related to Salmonella and raw ground poultry.
Human salmonellosis linked to contact with live poultry is an increasing public health concern. In 2012, eight unrelated outbreaks of human salmonellosis linked to live poultry contact resulted in 517 illnesses. In July 2012, PulseNet, a national molecular surveillance network, reported a multistate cluster of a rare strain of Salmonella Braenderup infections which we investigated. We defined a case as infection with the outbreak strain, determined by pulsed-field gel electrophoresis, with illness onset from 25 July 2012–27 February 2013. Ill persons and mail-order hatchery (MOH) owners were interviewed using standardized questionnaires. Traceback and environmental investigations were conducted. We identified 48 cases in 24 states. Twenty-six (81%) of 32 ill persons reported live poultry contact in the week before illness; case-patients named 12 different MOHs from eight states. The investigation identified hatchery D as the ultimate poultry source. Sampling at hatchery D yielded the outbreak strain. Hatchery D improved sanitation procedures and pest control; subsequent sampling failed to yield Salmonella. This outbreak highlights the interconnectedness of humans, animals, and the environment and the importance of industry knowledge and involvement in solving complex outbreaks. Preventing these infections requires a ‘One Health’ approach that leverages expertise in human, animal, and environmental health.
Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives.
In November 2009, we initiated a multistate investigation of Salmonella Montevideo infections with pulsed-field gel electrophoresis pattern JIXX01.0011. We identified 272 cases in 44 states with illness onset dates ranging from 1 July 2009 to 14 April 2010. To help generate hypotheses, warehouse store membership card information was collected to identify products consumed by cases. These records identified 19 ill persons who purchased company A salami products before onset of illness. A case-control study was conducted. Ready-to-eat salami consumption was significantly associated with illness (matched odds ratio 8·5, 95% confidence interval 2·1–75·9). The outbreak strain was isolated from company A salami products from an environmental sample from one manufacturing plant, and sealed containers of black and red pepper at the facility. This outbreak illustrates the importance of using membership card information to assist in identifying suspect vehicles, the potential for spices to contaminate ready-to-eat products, and preventing raw ingredient contamination of these products.
A number of methods have been developed to assist subjects in providing an estimate of portion size but their application in improving portion size estimation by children has not been investigated systematically. The aim was to develop portion size assessment tools for use with children and to assess the accuracy of children's estimates of portion size using the tools. The tools were food photographs, food models and an interactive portion size assessment system (IPSAS). Children (n 201), aged 4–16 years, were supplied with known quantities of food to eat, in school. Food leftovers were weighed. Children estimated the amount of each food using each tool, 24 h after consuming the food. The age-specific portion sizes represented were based on portion sizes consumed by children in a national survey. Significant differences were found between the accuracy of estimates using the three tools. Children of all ages performed well using the IPSAS and food photographs. The accuracy and precision of estimates made using the food models were poor. For all tools, estimates of the amount of food served were more accurate than estimates of the amount consumed. Issues relating to reporting of foods left over which impact on estimates of the amounts of foods actually consumed require further study. The IPSAS has shown potential for assessment of dietary intake with children. Before practical application in assessment of dietary intake of children the tool would need to be expanded to cover a wider range of foods and to be validated in a ‘real-life’ situation.