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A model devised by Thorpe & Li (J. Fluid Mech., vol. 758, 2014, pp. 94–120) that predicts the conditions in which stationary turbulent hydraulic jumps can occur in the flow of a continuously stratified layer over a horizontal rigid bottom is applied to, and its results compared with, observations made at several locations in the ocean. The model identifies two positions in the Samoan Passage at which hydraulic jumps should occur and where changes in the structure of the flow are indeed observed. The model predicts the amplitude of changes and the observed mode 2 form of the transitions. The predicted dissipation of turbulent kinetic energy is also consistent with observations. One location provides a particularly well-defined example of a persistent hydraulic jump. It takes the form of a 390 m thick and 3.7 km long mixing layer with frequent density inversions separated from the seabed by some 200 m of relatively rapidly moving dense water, thus revealing the previously unknown structure of an internal hydraulic jump in the deep ocean. Predictions in the Red Sea Outflow in the Gulf of Aden are relatively uncertain. Available data, and the model predictions, do not provide strong support for the existence of hydraulic jumps. In the Mediterranean Outflow, however, both model and data indicate the presence of a hydraulic jump.
Race, psychiatric history, and adverse life events have all been independently associated with postpartum depression (PPD). However, the role these play together in Black and Latina women remains inadequately studied. Therefore, we performed a case–control study of PPD, including comprehensive assessments of symptoms and biomarkers, while examining the effects of genetic ancestry.
We recruited our sample (549 cases, 968 controls) at 6 weeks postpartum from obstetrical clinics in North Carolina. PPD status was determined using the MINI-plus. Psychiatric history was extracted from medical records. Participants were administered self-report instruments to assess depression (Edinburgh Postnatal Depression Scale) and adverse life events. Levels of estradiol, progesterone, brain-derived neurotrophic factor, oxytocin, and allopregnanalone were assayed. Principal components from genotype data were used to estimate genetic ancestry and logistic regression was used to identify predictors of PPD.
This population was racially diverse (68% Black, 13% Latina, 18% European). Genetic ancestry was not a predictor of PPD. Case status was predicted by a history of major depression (p = 4.01E-14), lifetime anxiety disorder diagnosis (p = 1.25E-34), and adverse life events (p = 6.06E-06). There were no significant differences between groups in any hormones or neurosteroids.
Psychiatric history and multiple exposures to adverse life events were significant predictors of PPD in a population of minority and low-income women. Genetic ancestry and hormone levels were not predictive of case status. Increased genetic vulnerability in conjunction with risk factors may predict the onset of PPD, whereas genetic ancestry does not appear predictive.
Reliable radiocarbon dating depends upon well-defined samples. We have been investigating whether or not reliable 14C dates can be obtained directly from sub-fossil insect cuticle or biochemical fractions derived from it. Initial carbon and nitrogen stable isotope measurements on sub-fossil insect chitin from species with known feeding behaviors found within a single site (St Bees, Cumbria) clustered in a manner reminiscent of trophic level effects seen in terrestrial ecosystems. Although this finding implied some chemical stability, the measurement of CN ratios from the same samples indicated compositional variability. In addition, 14C dates obtained from these same samples were different from dates obtained from plant macrofossils found at the same depth. We have experimented with protocols designed to biochemically reduce chitin to its principle carbohydrate component glucosamine with the aim of using this compound to generate reliable 14C dates. Solvent extractions of sub-fossil chitin were carried out to remove both endogenous and exogenous lipid-soluble materials. Base hydrolysis reactions designed to extract polypeptides retained surprisingly high levels of contaminating amino acids. Proteinase K enzyme treatment had little affect on the level of amino acid contamination. Strong acid hydrolysis reactions designed to depolymerize chitin to glucosamine yielded only 5% glucosamine. Clearly alternative methods of chitin depolymerization must be identified before the purification and 14C dating of glucosamine from sub-fossil chitin becomes practical.
Health is an important aspect of individuals’ lives as they age. The aim of this study was to examine the relationship of sociodemographic factors, diagnosed chronic health conditions, and current depression with attitudes to aging in midlife.
A cross-sectional baseline analysis was conducted on the first 300 participants from the Canterbury Health, Ageing and Life Course study in New Zealand, a stratified randomized community longitudinal study of adults recruited between 49 and 51 years. Attitudes were measured using the Attitudes to Aging Questionnaire (AAQ) and analyzed with a range of prevalent diagnosed chronic conditions, current depression, and sociodemographic variables.
Individuals perceived their physical aging more negatively after a diagnosis of hypertension, arthritis or asthma. Diagnosed lifetime depression and anxiety, and current depression, showed strong relationships with attitudes to aging across domains. After controlling for sociodemographic factors and current depression, individuals with diagnosed hypertension, arthritis, asthma, lifetime depression or anxiety continued to report significantly more negative attitudes to aging. Current depression showed the strongest associations with attitudes to aging and mediated relationships of health on attitudes to aging.
Physical and mental health are related to attitudes to aging. Most chronic conditions examined are significantly associated with attitudes toward aging in the physical change domain. Diagnosed lifetime depression and anxiety, and current depression, are negatively related across attitudinal domains. Individuals can feel positive about aging while experiencing poorer health, but this is more difficult in the presence of low mood.
A progress report of the MASTER project is presented here. MASTER is a system of three heterodyne receivers based on SIS (superconductor–insulator–superconductor) tunnel junction mixers. In our instrument these mixers will allow direct down-conversion from 94, 225, and 345 to 1.5 GHz, the IF where the signal will be detected. This instrument, coupled to a 2–4 m telescope like the one proposed for the DOME C base in Antarctica and in conjunction with an Acusto Optical Spectrometer, can be used to detect emission lines associated with molecular clouds in the interstellar medium. The current status of a 94 GHz receiver, the prototype of MASTER, will be presented too. The study of the optical coupling between the receiver and MITO telescope in the Italian Alps will also be described.
The X-linked telomeric P elements (TPs) TP5 and TP6 regulate the activity of the entire P element family because they are inserted in a major locus for the production of Piwi-interacting RNAs (piRNAs). The potential for this cytotype regulation is significantly strengthened when either TP5 or TP6 is combined with a non-telomeric X-linked or autosomal transgene that contains a P element. By themselves, none of the transgenic P elements have any regulatory ability. Synergism between the telomeric and transgenic P elements is much greater when the TP is derived from a female. Once an enhanced regulatory state is established in a female, it is transmitted to her offspring independently of either the telomeric or transgenic P elements – that is, it works through a strictly maternal effect. Synergistic regulation collapses when either the telomeric or the transgenic P element is removed from the maternal genotype, and it is significantly impaired when the TPs come from stocks heterozygous for mutations in the genes aubergine, piwi or Su(var)205. The synergism between telomeric and transgenic P elements is consistent with a model in which P piRNAs are amplified by alternating, or ping-pong, targeting of primary piRNAs to sense and antisense P transcripts, with the sense transcripts being derived from the transgenic P element and the antisense transcripts being derived from the TP.
Gas-filled Time Projection Chambers (TPCs) with Gas Electron Multipliers (GEMs) and pixels appear suitable for direction-sensitive WIMP dark matter searches. We present the background and motivation for our work on this technology, past and ongoing prototype work, and a development path towards an affordable, 1-m3-scale directional dark matter detector, D3. Such a detector may be particularly suitable for low-mass WIMP searches, and perhaps sufficiently sensitive to clearly determine whether the signals seen by DAMA, CoGeNT, and CRESST-II are due to low-mass WIMPs or background.
Our previous work suggests that stressors that impact placental vascular growth result in a deformed chorionic surface shape, which reflects an abnormal placental three-dimensional shape. We propose to use variability of placental disk thickness as a reflector of deviations in placental vascular growth at the finer level of the fetal stems. We hypothesize that increased variability of thickness is associated with abnormal chorionic surface shape, but will be a predictor of reduced placental functional efficiency (smaller baby for a given placental weight) independent of shape. These measures may shed light on the mechanisms linking placental growth to risk of adult disease. The sample was drawn from the Pregnancy, Infection and Nutrition Study. In all, 94.6% of the cohort consented to placental examination. Of the 1023 delivered at term, those previously sectioned by the Pathology Department were excluded, leaving 587 (57%) cases with intact placentas that were sliced and photographed. The chorionic surface shape and the shape of a central randomly oriented placental slice were analyzed and measures were compared using correlation. Lower mean placental disk thickness and more variable disk thickness were each strongly and significantly correlated with deformed chorionic plate shapes. More variable disk thickness was strongly correlated with reduced placental efficiency independent of abnormal chorionic surface shape. Variability of placental disk thickness, simple to measure in a single randomly oriented central slice, may be an easily acquired measure that is an independent indicator of lowered placental efficiency, which may in turn program the infant and result in increased risk for development of adult diseases.
Using a digital-image-based representation of a continuum composite, we apply computer simulation techniques to obtain the elastic moduli of a matrix containing randomly-centered circular voids. As the area fraction of the voids increases, the elastic moduli of the composite decrease until they eventually vanish at the percolation threshold. We compare our results with an effective medium theory, which predicts that Poisson ratio tends to a fixed value as the percolation threshold is approached, independent of the values of the elastic moduli in the pure system. Our results are also compared with recent experimental results.
Since the middle of the 90's, GaN epitaxy techniques have been developed, using either MOCVD or MBE growth methods. A low cost approach is presented aiming at satisfying thermal issues encountered on conventional substrates such as SiC, Sapphire and more recently Silicon. Domain of application are being covered with their associated challenges: RF and High Power applications. Stress engineering is one of the key parameters.
Maternal malaria and under-nutrition are established risk factors for small-for-gestational-age (SGA) births; however, whether malaria is associated with intrauterine growth restriction (IUGR) is unknown. We investigated IUGR risk among 177 HIV-negative pregnant women enrolled in a longitudinal ultrasound study conducted in Democratic Republic of Congo from May 2005 to May 2006. Malaria infection, maternal anthropometrics, and ultrasound estimated fetal weight were measured monthly. All positive malaria cases were treated and intermittent presumptive therapy (IPTp) provided. Log-binomial regression models for IUGR were fitted using generalized estimating equations to account for statistical clustering of repeat IUGR measurements. Twenty-nine percent of fetuses experienced an episode of IUGR with the majority occurring in the third trimester. The risk of IUGR associated with malaria was greatest after three or more cumulative infections (RR 3·3, 95% CI 1·3–8·2) and was two- to eight-fold higher among women with evidence of under-nutrition. Receiving antimalarial treatment in the previous month (for IPTp or treatment) was significantly protective against IUGR (RR 0·5, 95% CI 0·3–0·7). The interaction observed between malaria and under-nutrition suggests that antenatal programmes in malaria endemic areas should incorporate nutritional screening and supplementation in addition to IPTp.
Red Maasai and Dorper sheep were evaluated for their resistance to gastro-intestinal (GI) nematode parasites (predominantly Haemonchus contortus), productivity and productive efficiency (assessed on a metabolizable energy basis) in experiments undertaken at the Kenyan coast (sub-humid environment) and the Kenya highlands (semi-arid environment). In both ewes and lambs there were few significant genotype by environment (G X E) interactions for either resistance (assessed by faecal egg counts-FEC) or resilience (assessed by blood packed red cell volume-PCV) to GI nematodes. Red Maasai sheep were consistently more resistant (low FEC) and more resilient (high PCV) than Dorper sheep. However, there were significant G X £ interactions for ewe reproductive performance and for ewe and lamb mortality rates and live weights. These interactions were due to very poor performance of the Dorper compared to the Red Maasai in the sub-humid coastal environment and to the much improved performance of the Dorper in the semi-arid environment. When these component traits were combined into estimates of flock productivity and productive efficiency there were highly significant GXE interactions with the Red Maasai sheep being considerably more efficient than Dorper sheep in the sub-humid environment, while in the semi-arid environment there was a negligible breed difference in productive efficiency. The results are discussed in terms of breeding strategies for smallholder farmers and pastoralists managing sheep in low-input systems in sub-humid and semi-arid environments.
Magnetization measurements, transmission electron microscopy (TEM), and high-resolution micro-x-ray fluorescence (μ-XRF) using a synchrotron radiation source (Advanced Photon Source) were used to examine Fe3O4 particle agglomerates of nominally 10-nm particles at low concentrations (down to 0.03%) in thick epoxy resin samples. The magnetization measurements showed that at low concentrations (<0.5%) the magnetite particles, although closely packed in the agglomerates, did not interact magnetically. Predicated on a 2-μm sample step scan, the μ-XRF results were compatible with the presence of spherical agglomerates due to magnetostatic attraction, and these ranged in size from 100 to several thousand nanometers, as observed in TEM measurements. At smaller step scans the resolution could be significantly improved. Thus, the synchroton μ-XRF method was very useful in detecting very small concentrations of particles in thick samples and could probably be used to detect particles in amounts as low as 10−16 g.
Burow’s solution (13 per cent aluminium acetate) has been found to inhibit in vitro the growth of most commonly occurring bacteria found in the discharging ear. An in vitro study has shown that the minimum inhibitory concentration of Burow’s solution for these organisms lies between a 1:80 and a 1:160 dilution. This paper reports on a clinical trial that incorporated 67 discharging ears to establish the most effective strength of aluminium acetate solution. There was no statistical difference in the effectiveness of full strength Burow’s solution compared to 3.25 per cent aluminium acetate solution (a quarter strength Burow’s solution). Response rates of 80.8 per cent and 75 per cent respectively following a two-week treatment period were achieved using these two solutions. A 1.3 per cent aluminium acetate solution (1/10 strength Burow’s solution) was found to be markedly inferior. Bacteriological and audiological profiles were recorded for each patient.
The psychometric properties of a new scale, the Obsessive Compulsive
Inventory (OCI; Foa, Kozak, Salkovskis, Coles, & Amir, 1998), were examined
in a nonclinical student sample. The study was a partial replication of the
original validation study by Foa et al. Test-retest reliability, internal
consistency, and convergent validity were examined using a sample of 126
undergraduate psychology students. Statistical analyses (Pearson's r
and Cronbach's alpha) indicated adequate test-retest reliability for
the full scales and subscales (coefficients ranging from 0.69 to 0.88) and
high internal consistency (all coefficients exceeding 0.7). Convergent
validity with the Maudsley Obsessional Compulsive Inventory (MOCI; Hodgson
& Rachman, 1977) was adequate for the full scales and for the Washing and
Checking subscales (coefficients ranging from 0.61 to 0.75). The OCI is a
useful supplement to existing self-report measures of obsessive-compulsive
The object of these experiments was to study the pathogenesis and
kinetics of Theileria annulata infection in the efferent
lymph of the draining lymph nodes of calves. Efferent lymphatics of calves
were cannulated prior to infection with T.
annulata sporozoite or an allogeneic schizont cell line. Potentially
lethal sporozoite challenge induced cell shut-down from
days 4–6 and then a massive increase in output of blasting cells
(both infected and non-infected) in the efferent lymph.
The rate of lymph flow and total cell output increased to 5 to 10-fold
from day 6 onwards. Sporozoites were never isolated
from the efferent lymph. However, large numbers of parasite-infected cells
were seen in efferent lymph from the sixth day
of infection. The animals inoculated with an allogeneic T. annulata-infected
cell line exhibited only a small increase in flow
rate and cell output. Parasite-infected cells of recipient origin were
seen in efferent lymph from day 11 onwards. However,
cells of donor origin were never isolated either from efferent lymph or
peripheral blood. Thus the parasite transferred from
the inoculated donor cell line to the cells of the recipient before schizonts
appeared in efferent lymph.
At present there are no topical otological preparations on the World Health Organisation's essential drug list, largely due to the ototoxic potential of preparations containing aminoglycoside antibiotics. Acetic acid and Burow's solution have long been used in the treatment of the discharging ear. The aim of this study was to ascertain the antibacterial activity of these two preparations against the most commonly occurring bacteria isolated from discharging ears in our department. Twenty fresh isolates of each of the following organisms – Pseudomonas aeruginosa, Staphylococcus aureus, Proteus mirabilis and Streptococcus pyogenes – were plated onto blood agar and tested against one per cent, two per cent and three per cent acetic acid and Burow's solution (13 per cent aluminium acetate). The activity of each agent was ascertained by the size of the zone of inhibition of bacterial growth. Burow's solution showed significantly larger average zones of inhibition than acetic acid (p < 0.001). The two per cent and three per cent acetic acid as well as the Burow's solution were active against all the organisms tested.