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.
The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
The use of statistical/machine learning (ML) approaches to materials science is experiencing explosive growth. Here, we review recent work focusing on the generation and application of libraries from both experiment and theoretical tools. The library data enables classical correlative ML and also opens the pathway for exploration of underlying causative physical behaviors. We highlight key advances facilitated by this approach and illustrate how modeling, macroscopic experiments, and imaging can be combined to accelerate the understanding and development of new materials systems. These developments point toward a data-driven future wherein knowledge can be aggregated and synthesized, accelerating the advancement of materials science.
In lifecourse studies that encompass the adolescent period, the assessment of pubertal status is important, but can be challenging. We aimed to identify current methods for pubertal assessment and assess their appropriateness for population-based research by combining a review of the literature with the views of experts in the field. We searched bibliographic databases, extracted data and assessed study quality to inform a workshop with 21 experts. Acceptability of different approaches was explored with a panel of ten adolescents. We screened 11,935 abstracts, assessed 157 articles and summarised results from 38 articles. Combining these with the opinions of experts, self-assessment was found to be a practical method for use in studies where agreement with the gold standard of clinical assessment by physical examination to within one Tanner stage was acceptable. Serial measures of height and foot size accurately indicated timing of the pubertal growth spurt and age at peak height velocity, and were seen as feasible within longitudinal studies. Hormonal and radiological methods did not offer a practical means of assessing pubertal status. Assessment of voice maturation was promising, but needed validation. Young people thought that self-assessment, foot size and voice assessments were acceptable, and preferred an assessor of the same sex for clinical assessment. This review thus informs researchers working in lifecourse and adolescent health, and identifies future directions in order to improve validity of the methods.
Background: Observational studies have reported an association between childhood obesity and a higher risk of multiple sclerosis (MS). However, the difficulties to fully account for confounding and long recall periods make causal inference from these studies challenging. The objective of this study was to assess the contribution of childhood obesity to the development of MS through Mendelian randomization, which uses genetic associations to minimize the risk of confounding. Methods: We selected 23 independent genetic variants strongly associated with childhood body mass index (BMI) in a genome-wide association study (GWAS) which included 47,541 children. The corresponding effects of these variants on risk of MS were obtained from a GWAS of 14,802 MS cases and 26,703 controls. Standard two-sample Mendelian randomization methods were performed, with additional sensitivity analyses to assess the likelihood of bias from genetic pleiotropy. Results: The inverse-variance weighted MR analysis revealed that one standard deviation increase in childhood BMI increased odds of MS by 26% (odds ratio=1.26, 95% confidence interval 1.10-1.45, p=0.001). There was no significant heterogeneity across the individual estimates. Sensitivity analyses were consistent with the main findings and provided no evidence of pleiotropy. Conclusions: This study provides genetic support of a role for increased childhood BMI in the development of MS.
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.
Qualitative inorganic analysis is required for the identification of unknowns, the classification of type, and sometimes to decide what subsequent quantitative analysis is needed. The traditional way of performing qualitative XRF analysis on unknown materials is by subjecting the sample to a full spectral scan. This takes time and an experienced operator to interpret the spectra. Classifying the elements detected as major, minor or trace can also be person dependent. Round robin tests have confirmed this by showing considerable variation in results between laboratories.
Microsupercapacitors (MSCs) are miniaturized energy storage devices that can be integrated in an on-chip platform as a component of a power supply for Internet of things’ sensors. Integration of these on-chip MSCs require them to be fabricated through CMOS compatible fabrication techniques such as spin coating. One of the biggest challenges in spin coated MSCs is the poor surface adhesion. In this work, we present a CMOS compatible electrode deposition process with enhanced adhesion and retention for reduced graphene oxide (rGO) using spin coating. In order to improve the adhesion and surface uniformity of the deposited electrode material, the surface of Si/SiO2 wafers was subjected to roughening through Fe nanoparticle formation. A 4 nm thick Fe layer deposition substantially magnified the average mean surface roughness of the substrates. In comparison with substrates without the Fe deposition, the treated ones have more than 300% improvement in surface coverage and rGO mass retention after sonication testing. These results suggest that the surface roughening has a positive influence on electrode deposition via a spin-coating method.
Landraces (including heritage varieties) are an important agrobiodiversity resource offering considerable value as a buffer against crop failures, as a crop for niche markets, and as a source of diversity for crop genetic improvement activities underpinning future food security. Home gardens are reservoirs of landrace diversity, but some of the accessions held in them are vulnerable or threatened with extinction. Those associated with seed saving networks have added security, for example, ca. 800 varieties are stored in the Heritage Seed Library (HSL) of Garden Organic, UK. In this study, Amplified Fragment Length Polymorphisms-based genetic analysis of accessions held in the HSL was used to (a) demonstrate the range of diversity in the collection, (b) characterize accessions to aid collection management and (c) promote broader use of the collection. In total, 171 accessions were included from six crops: Vicia faba L., Pisum sativum L., Daucus carota L., Cucumis sativus L., Lactuca sativa L. and Brassica oleracea L. var. acephala (DC.) Metzq. Average expected heterozygosity ranged from 0.18 to 0.28 in D. carota; 0.02–0.18 in P. sativum; 0.05–0.18 in L. sativa; 0.15–0.26 in B. oleracea var. acephala; 0.15–0.37 in C. sativus and 0.07–0.36 in V. faba. Genetic diversity and Fst values generally reflected the breeding system and cultivation history of the different crops. Comparisons of the diversity found in heritage varieties with that found in commercial varieties did not show a consistent pattern. Principal coordinates analysis and Unweighted Pair Group Method with Arithmetic Mean cluster analysis were used to identify four potential duplicate accession pairs.
Breakthrough Listen is a 10-yr initiative to search for signatures of technologies created by extraterrestrial civilisations at radio and optical wavelengths. Here, we detail the digital data recording system deployed for Breakthrough Listen observations at the 64-m aperture CSIRO Parkes Telescope in New South Wales, Australia. The recording system currently implements two modes: a dual-polarisation, 1.125-GHz bandwidth mode for single-beam observations, and a 26-input, 308-MHz bandwidth mode for the 21-cm multibeam receiver. The system is also designed to support a 3-GHz single-beam mode for the forthcoming Parkes ultra-wideband feed. In this paper, we present details of the system architecture, provide an overview of hardware and software, and present initial performance results.
The surprise outcome of the 2016 presidential election continues to raise more questions as experts grapple with the evidence for why most prognosticators considered a Hillary Clinton victory almost certain. This article uses the 2016 Cooperative Congressional Election Study data to show that a primary explanation for why the election of Donald Trump was difficult to predict is that the bulk of his support did not materialize until Election Day, in the battleground states that he had to carry to win the Electoral College.
We observed pediatric S. aureus hospitalizations decreased 36% from 26.3 to 16.8 infections per 1,000 admissions from 2009 to 2016, with methicillin-resistant S. aureus (MRSA) decreasing by 52% and methicillin-susceptible S. aureus decreasing by 17%, among 39 pediatric hospitals. Similar decreases were observed for days of therapy of anti-MRSA antibiotics.
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.
Salmonella prevalence in UK pigs is amongst the highest in Europe, highlighting the need to investigate pig farms which have managed to maintain a low Salmonella seroprevalence. A total of 19 pig farms that had a consistently low (<10%) seroprevalence over 4 years (named Platinum farms) were compared against 38 randomly selected Control farms, chosen to match the same distribution of production types and geographical distribution of the Platinum farms. Each farm was visited and floor faeces and environmental samples were collected. It was shown that Control farms had a significantly higher median percentage of pooled faecal samples positive for Salmonella compared with the Platinum farms (12.1% and 0.4% for pooled faecal samples, respectively) and were more likely to have serovars of public health importance detected (S. Typhimurium/ monophasic variants or S. Enteritidis). Considering the comprehensive on-farm sampling, the identification of farms negative for Salmonella, along with the identification of those that had maintained low prevalence over a long period is important. The risk factor analyses identified pelleted feed, feed deliveries crossing farm perimeter and regular antibiotic use as associated with being a Control farm. Performance data indicated that Platinum farms were performing better for slaughter live weight than Controls. Limited assessments of available pig movement records suggested that the source of pigs was not key to Platinum status, but further study would be needed to confirm this finding. These results emphasise that maintaining very low prevalence on UK farms is achievable.
Textural and chemical data are reviewed for amphiboles occurring in Cr-diopside series and Al-augite series xenoliths; as megacrysts in a variety of igneous environments; and also as minor phases in tectonic slices of upper-mantle peridotite. New data are given for pargasite and associated phases in a lherzolite from Tanzania and in kelyphite replacing garnet in a S. African kimberlite xenolith. It is concluded that only pargasites and titaniferous pargasites occurring in Cr-diopside series blocks have formed under upper-mantle conditions. Although amphibole is present in the upper mantle, as suggested by Oxburgh (1964), its relative paucity suggests it is not a major alkali and water storage site; phlogopite is a more likely candidate, particularly in the deeper parts of the upper mantle.
Peridotite xenoliths 73–106 and 73–109 have coarse textures. All minerals in 73–106 are very Ti-rich, and include olivine (Fo 87.6), orthopyroxene (En 90.0), garnet (core TiO2 0.8, Cr2O3 7; rim 1.4, 4 wt. %), spinel (TiO2 5, Cr2O3 38), clinopyroxene (A12O3 1–8) secondary mica (TiO2 6, Cr2O3 2.5 near garnet 0.5 away from garnet), and serpentine (FeO 5–12) enclosing perovskite-rimmed ilmenite and minute apatites. All minerals in peridotite 73–109 are Ti-poor, and include olivine (Fo 92.6), orthopyroxene (En 93.6), garnet (Cr2O3 3.1–3.8), spinel (55), ureyitic diopside, primary mica (TiO2 0.06, Cr2O3 1.0, BaO 0.5, Cl 0.04), and serpentine (FeO 2–23). Various thermometers indicate ∼ 1350K (73–106) and 1100K (73–109). The low Al2O3 in the orthopyroxenes gives 39–47 kb for 73–109 from the Wood-Banno barometer. In 73–106, the spinel lies in secondary mica next to the garnet rim, whereas the spinel of 73–109 occurs in grains enclosed by garnet. The former assemblage indicates diffusion-dependent disequilibrium, whereas the latter is attributed to simultaneous growth of spinel and garnet, perhaps consequent upon exsolution from orthopyroxene. Complex behaviour was found for the Cr/Al distribution in published analyses of garnet and spinel. The 73–109 pair lies near the Thaba Putsoa trend, and the 73–106 assemblages are displaced towards the kelyphite region in which garnet and spinel have similar Cr/Al. Spinel and garnet may coexist over a 30 kb pressure interval ranging from ∼ 16 kb for low bulk Cr to ∼ 40 kb for high Cr.
Svetlozarite, previously described as a new member of the mordenite group of zeolites, is reinterpreted as a multiply twinned and highly faulted dachiardite. X-ray diffraction study and transmission electron microscopy revealed (001) twins and (100) stacking faults. The former are attributed at least mainly to the insertion of a b glide plane between dachiardite sheets at each twin interface, which preserves the 5-ring linkages between the sheets. The latter are associated with loss of the C face-centring relation, and are attributed to replacement of shared 5-rings by linked 4-rings in the dachiardite sheets. Further study is needed to determine whether the structural faults in the dachiardite structures are chemically controlled.
Thirty-one natural olivines, of which 25 had been previously analysed by wet chemical methods, have been analysed for Mg, Fe, Mn, Ca, Ni, and Co by electron-microprobe techniques. The totals of the olivine molecules Fo, Fa, etc., calculated from the above metals vary from 97·6 to 101·5 with a mean of 99·6%. Twenty-one of the specimens had been used previously by Yoder and Sahama to prepare a determinative curve between mole per cent. Fo and the lattice spacing d130. Yoder and Sahama had found that the data for natural olivines showed large random displacements from a straight line, and that the best straight line deviated for low Fo values from that for synthetic olivines. A plot of Fo determined from the microprobe vs. d130 corrected for lattice expansion caused by Ca and Mn shows no systematic deviation between natural and synthetic specimens, and only small deviations from the best continuous curve (maximum 4% in Fo assuming no error in d130). The maximum contents found for Mn, Ca, Ni, and Co were 3·2, 0·54, 0·33, and 0·03%, respectively. For these minor constituents, some of the wet chemical analyses agreed very well with the microprobe results while others showed large deviations. Although the substitution of Ca is small, it can affect considerably the determination of mole per cent. Fo from d130.
After specimen preparation and calibration have been carried out, microprobe analyses for most major and minor (but not trace) elements in common silicates can be made with an accuracy of about 0·5 to 5% of the amount present in about one minute for each group of three elements. Although standard chemical methods applied to large homogeneous samples will retain their fundamental reference value, microprobe techniques with their high spatial resolution, relative freedom from contamination problems, high speed, and moderate to good accuracy promise to revolutionize analytical programmes in mineralogy and petrology.
Thoroughbred mares (Equus caballus) are usually first teased 6 days post foaling and during this brief (often 3-6 minutes) process the mare's foal will be left alone in its stable. This will be repeated daily until the mare goes out of season. During this part of her cycle she may later be sent for covering by the resident stallion. On some farms the foal is alone in its stable during covering and this period can last for anything from 20 minutes to an hour, during which the foal typically exhibits signs of considerable distress. Though the foal can be heard whinnying for the mare, it has not previously been noted what behaviours the distressed foal exhibits during this separation. Though a recent study by Houpt (2002) looked at responses of 10 pony mares and their foals to brief weekly periods of separation at up to nine weeks of age, most research on separation distress in foals has previously been done with respect to the artificial weaning process, an event that most Thoroughbred foals experience by 6-7 months of age.
The in situ dry matter disappearance technique (Ørskov and McDonald, 1979) evaluates forages for their rate and extent of degradation in the rumen. However, this method does not allow the evaluation of a large number of samples at one and the same time and therefore which limits screening of treatments applied to forages. The in vitro gas production method is faster and allows handling of many samples per batch; therefore, gas production could be an alternative to the use of nylon bags if the response to treatments between the two methods is similar among treated forages. The objective of this experiment was to compare results obtained with both the gas production and the nylon bag techniques for forages treated with four levels of maceration and conserved as hay or silage.
We examined risk factors associated with the intestinal acquisition of antimicrobial-resistant extraintestinal pathogenic Escherichia coli (ExPEC) and development of community-acquired urinary tract infection (UTI) in a case-control study of young women across Canada. A total of 399 women were recruited; 164 women had a UTI caused by E. coli resistant to ⩾1 antimicrobial classes and 98 had a UTI caused by E. coli resistant to ⩾3 antimicrobial classes. After adjustment for age, student health service (region of Canada) and either prior antibiotic use or UTI history, consumption of processed or ground chicken, cooked or raw shellfish, street foods and any organic fruit; as well as, contact with chickens, dogs and pet treats; and travel to Asia, were associated with an increased risk of UTI caused by antimicrobial resistant E. coli. A decreased risk of antimicrobial resistant UTI was associated with consumption of apples, nectarines, peppers, fresh herbs, peanuts and cooked beef. Drug-resistant UTI linked to foodborne and environmental exposures may be a significant public health concern and understanding the risk factors for intestinal acquisition of existing or newly emerging lineages of drug-resistant ExPEC is important for epidemiology, antimicrobial stewardship and prevention efforts.