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 email@example.com
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.
Additional crystallographic data are given for the recently reported mineral middlebackite, which has been described for discoveries at Iron Knob in South Australia and Passo di San Lugano near Trento, Italy. The material examined in the present study was from a third finding of the mineral, viz. from a quartz outcrop at Mooloo Downs Station in Western Australia within which it was co-located with the chemically- and structurally-related mineral moolooite, CuIIC2O4·nH2O, reported by Clarke and Williams (1986). In this study, the crystal structure was elucidated independently of the other studies using a combination of the a priori charge flipping and simulated annealing methods with synchrotron radiation diffraction (SRD) powder data. The principal crystal data for the Mooloo Downs material are: space group P21/c with lattice parameters a = 7.2659(18) Å, b = 5.7460(11) Å, c = 5.6806(11) Å, β = 104.588(3)°; Vc = 229.46(18) Å3; empirical formula CuII2C2O4(OH)2 with 2 formula units per unit cell; and calculated density = 3.605 g cm−3. The lattice parameters agree approximately with values given for the other studies, but not within the reported error estimates. The atom coordinates, interatomic distances, and angles for the Mooloo Downs material are compared with those from the other studies using single crystal data, with the values from all three studies agreeing approximately, but again not within the reported uncertainties. The crystal chemistry found for middlebackite received strong confirmation through the synthesis for the first time of di-copper oxalate di-hydroxide. Laboratory X-ray diffraction powder data for the synthetic form of the mineral from this study agree closely with the SRD data for the natural mineral.
Overweight and obesity may increase risk of disease progression in men with prostate cancer, but there have been few studies of weight loss interventions in this patient group. In this study overweight or obese men treated for prostate cancer were randomised to a self-help diet and activity intervention with telephone-based dietitian support or a wait-list mini-intervention group. The intervention group had an initial group meeting, a supporting letter from their urological consultant, three telephone dietitian consultations at 4-week intervals, a pedometer and access to web-based diet and physical activity resources. At 12 weeks, men in both groups were given digital scales for providing follow-up weight measurements, and the wait-list group received a mini-intervention of the supporting letter, a pedometer and access to the web-based resources. Sixty-two men were randomised; fifty-four completed baseline and 12-week measurements, and fifty-one and twenty-seven provided measurements at 6 and 12 months, respectively. In a repeated-measures model, mean difference in weight change between groups (wait-list mini-intervention minus intervention) at 12 weeks was −2·13 (95 % CI −3·44, −0·82) kg (P = 0·002). At 12 months the corresponding value was −2·43 (95 % CI −4·50, −0·37) kg (P = 0·022). Mean difference in global quality of life score change between groups at 12 weeks was 12·3 (95 % CI 4·93, 19·7) (P = 0·002); at 12 months there were no significant differences between groups. Results suggest the potential of self-help diet and physical activity intervention with trained support for modest but sustained weight loss in this patient group.
Schizophrenia is a highly heritable disorder, linked to several structural abnormalities of the brain. More specifically, previous findings have suggested that increased gyrification in frontal and temporal regions are implicated in the pathogenesis of schizophrenia.
The current study included participants at high familial risk of schizophrenia who remained well (n = 31), who developed sub-diagnostic symptoms (n = 28) and who developed schizophrenia (n = 9) as well as healthy controls (HC) (n = 16). We first tested whether individuals at high familial risk of schizophrenia carried an increased burden of trait-associated alleles using polygenic risk score analysis. We then assessed the extent to which polygenic risk was associated with gyral folding in the frontal and temporal lobes.
We found that individuals at high familial risk of schizophrenia who developed schizophrenia carried a significantly greater burden of risk-conferring variants for the disorder compared to those at high risk (HR) who developed sub-diagnostic symptoms or remained well and HC. Furthermore, within the HR cohort, there was a significant and positive association between schizophrenia polygenic risk score and bilateral frontal gyrification.
These results suggest that polygenic risk for schizophrenia impacts upon early neurodevelopment to confer greater gyral folding in adulthood and an increased risk of developing the disorder.
The ability of the aorta to buffer blood flow and provide diastolic perfusion (Windkessel function) is a determinant of cardiovascular health. We have reported cardiac dysfunction indicating downstream vascular abnormalities in young adult baboons who were intrauterine growth restricted (IUGR) at birth as a result of moderate maternal nutrient reduction. Using 3 T MRI, we examined IUGR offspring (eight male, eight female; 5.7 years; human equivalent 25 years) and age-matched controls (eight male, eight female; 5.6 years) to quantify distal descending aortic cross-section (AC) and distensibility (AD). ANOVA showed decreased IUGR AC/body surface area (0.9±0.05 cm2/m2v. 1.2±0.06 cm2/m2, M±s.e.m., P<0.005) and AD (1.7±0.2 v. 4.0±0.5×10−3/mmHg, P<0.005) without sex difference or group-sex interaction, suggesting intrinsic vascular pathology and impaired development persisting in adulthood. Future studies should evaluate potential consequences of these changes on coronary perfusion, afterload and blood pressure.
Measurements of the electrical conductivity of subglacial water provide a useful complement to measurements of pressure and turbidity. In the summer season, fluctuations of conductivity can be attributed to changes in water transport, water provenance and subglacial residence time. These explanations are unlikely to apply during the winter season because surface melt sources are not active and the subglacial water system is predominantly unconnected. Thus, fluctuations in water conductivity during the winter months seem paradoxical. To introduce a quantitative basis for comprehending such phenomena, we develop an interpretative model of the hydrochemical interaction between a water-filled borehole and a subglacial aquifer. The electrical conductivity of water near the borehole–aquifer contact is affected not only by diffusion but also by advective transport of solute between the two reservoirs in response to pressure forcing of the system. Using records of ice strain, water pressure and electrical conductivity from unconnected boreholes in Trapridge Glacier, we demonstrate that changes in borehole geometry caused by ice-strain events provide a plausible mechanism for at least some of the observed fluctuations of electrical conductivity. Conductivity records provide information regarding advective coupling of the borehole–aquifer system that is not available from pressure records alone.
A 141m ice core was recovered from Combatant Col (51.385° N, 125.258° W; 3000ma.s.l.), Mount Waddington, Coast Mountains, British Columbia, Canada. Records of black carbon, dust, lead and water stable isotopes demonstrate that unambiguous seasonality is preserved throughout the core, despite summer surface snowmelt and temperate ice. High accumulation rates at the site (>4 m ice eq. a-1) limit modification of annual stratigraphy by percolation of surface meltwater. The ice-core record spans the period 1973–2010. An annually averaged time series of lead concentrations from the core correlates well with historical records of lead emission from North America, and with ice-core records of lead from the Greenland ice sheet. The depth-age scale for the ice core provides sufficient constraint on the vertical strain to allow estimation of the age of the ice at bedrock. Total ice thickness at Combatant Col is ~250 m; an ice core to bedrock would likely contain ice in excess of 200 years in age. Accumulation at Combatant Col is significantly correlated with both regional precipitation and large-scale geopotential height anomalies.
The upper 20—30 m of ice-rich permafrost at three sites overridden by the northwest margin of the Laurentide ice sheet in the Tuktoyaktuk Coastlands, western Arctic Canada, comprise massive ice beneath ice-rich diamicton or sandy silt. The diamicton and silt contain (1) truncated ice blocks up to 15 m long, (2) sand lenses and layers, (3) ice veins dipping at 20—30°, (4) ice lenses adjacent and parallel to sedimentary contacts, and (5) ice wedges. The massive ice is interpreted as intrasedimental or buried basal glacier ice, and the diamicton and silt as glacitectonite that has never thawed. Deformation of frozen ground was mainly ductile in character. Deformation was accompanied by sub-marginal erosion of permafrost, which formed an angular unconformity along the top of the massive ice and supplied ice clasts and sand bodies to the overlying glacitectonite. After deformation and erosion ceased, postglacial segregated ice and ice- wedge ice developed within the deformed permafrost.
A high resolution X-ray image from the Einstein Observatory of the young supernova remnant G292.0+1.8 (MSH11–54), previously noted as peculiar in terms of its spectral and morphological properties at optical and radio wavelengths, also shows an unusual X-ray morphology. Instead of a limb-brightened X-ray shell characteristic of most SNRs, the remnant consists of a central bar-like feature superposed on an ellipsoidal disc of approximately uniform surface brightness. We attribute the bar emission to a ring of oxygen-rich material ejected in the equatorial plane of a massive rotating progenitor, and the uniform disc component to emission from material with roughly cosmic composition heated by the accompanying blast wave. This interpretation provides observational support for the rotating precursor model of a Type II supernova discussed by Bodenheimer and Woosley.
More than 3000 radial velocity observations across the face of the Crab Nebula are used to investigate its 3-dimensional properties. In the standard model it consists of a thick hollow shell with synchrotron emission from within. We show that the thick shell is composed of bright inner and faint outer components
The Protoplanetary Discussions conference—held in Edinburgh, UK, from 2016 March 7th–11th—included several open sessions led by participants. This paper reports on the discussions collectively concerned with the multi-physics modelling of protoplanetary discs, including the self-consistent calculation of gas and dust dynamics, radiative transfer, and chemistry. After a short introduction to each of these disciplines in isolation, we identify a series of burning questions and grand challenges associated with their continuing development and integration. We then discuss potential pathways towards solving these challenges, grouped by strategical, technical, and collaborative developments. This paper is not intended to be a review, but rather to motivate and direct future research and collaboration across typically distinct fields based on community-driven input, to encourage further progress in our understanding of circumstellar and protoplanetary discs.
Although the use of donor sperm as a treatment modality for male infertility has become common place, the health outcomes for those conceived has been poorly studied. A structured search of the literature using PubMed, EMBASE and Cochrane Reviews was performed to investigate the health outcomes of offspring conceived from donor sperm. Eight studies were eligible and included in the review, and of these, three were included in a meta-analysis. Meta-analysis of clinical outcomes showed that donor sperm neonates are not at increased risk of being born of low birth weight (<2500 g), preterm (<37 weeks) or with increased incidences of birth defects, than spontaneously conceived neonates.
Background: Autistic regression (AR) accounts for 20-40% of patients with Autism Spectrum Disorder (ASD) .1 Literature demonstrates specific immune changes in AR patients,2 as well as association between AR and autoimmune thyroiditis.3 Our study explores the clinical association between AR and autoimmunity, focusing on possible precipitants and familial autoimmunity, in comparison with patients with infantile autism (IA). Methods: charts of children diagnosed with ASD in 2014 were reviewed, and patients were classified as either AR or IA based on Autism Diagnostic Interview (ADI-R) criteria.4 Information regarding pregnancy, perinatal complications, febrile illness preceding the diagnosis, and family history of autoimmune conditions was collected. Results: 206 children had IA and 33 had AR. No difference was found in prevalence of pregnancy or perinatal complications. The incidence of febrile illness in the 6 months prior to diagnosis and the prevalence of familial autoimmunity, were significantly higher in the AR group (p<0.001). Diabetes type I, celiac disease, autoimmune thyroiditis, and inflammatory bowel disease were more common in families of AR patients (p<0.05). Conclusions: the association between AR and preceding febrile illness, as well as familial autoimmunity, supports the notion of AR as a separate entity within ASD, possibly mediated by autoimmune changes.
Donated oocytes are a treatment modality for female infertility which is also associated with increased risks of preeclampsia. Subsequently it is important to evaluate if there is concomitant increased risks for adverse neonatal events in donated oocyte neonates. A structured search of the literature using PubMed, EMBASE and Cochrane Reviews was performed to investigate the perinatal health outcomes of offspring conceived from donor oocytes compared with autologous oocytes. Meta-analysis was performed on comparable outcomes data. Twenty-eight studies were eligible and included in the review, and of these, 23 were included in a meta-analysis. Donor oocyte neonates are at increased risk of being born with low birth weight (<2500 g) [risk ratio (RR): 1.18, 95% confidence interval (CI): 1.14–1.22, P-value (P)<0.00001], very low birth weight (<1500 g) (RR: 1.24, CI: 1.15–1.35, P<0.00001), preterm (<37 weeks) (RR: 1.26, CI: 1.23–1.30, P<0.00001), of lower gestational age (mean difference −0.3 weeks, CI: −0.35 weeks to −0.25 weeks, P<0.00001), and preterm with low birth weight (RR: 1.24, CI: 1.19–1.29, P<0.00001), when compared with autologous oocyte neonates. Conversely, low birth weight outcomes were improved in term donor oocyte neonates (RR: 0.86, CI: 0.8–0.93, P=0.0003). These negative outcomes remained significant when controlling for multiple deliveries. The donor oocyte risk rates are higher than those found in general ART outcomes, are important considerations for the counselling of infertile patients and may also influence the long term health of the offspring.
Radio interferometric observations of extragalactic radio sources have been made with antennas at the Haystack Observatory in Massachusetts and the Owens Valley Radio Observatory in California during fourteen separate experiments distributed between September 1976 and May 1978. The components of the baseline vector and the coordinates of the sources were estimated from the data from each experiment separately. The root-weighted-mean-square scatter about the weighted mean (“repeatability”) of the estimates of the length of the 3900 km baseline was approximately 7 cm, and of the source coordinates, approximately or less, except for the declinations of low-declination sources. With the source coordinates all held fixed at the best available, a posteriori, values, and the analyses repeated for each experiment, the repeatability obtained for the estimate of baseline length was 4 cm. From analyses of the data from several experiments simultaneously, estimates were obtained of changes in the x component of pole position and in the Earth's rotation (UT1). Comparison with the corresponding results obtained by the Bureau International de l'Heure (BIH) discloses systematic differences. In particular, the trends in the radio interferometric determinations of the changes in pole position agree more closely with those from the International Polar Motion Service (IPMS) and from the Doppler observations of satellites than with those from the BIH.
Linearly polarized SiO emission spread over 12 km/s has been detected from the star R Leo. The position angle of polarized emission varies systematically with respect to the spectral line center. Interpreted in terms of radiative transfer theory, this change in position angle may be due to magnetorotation, which allows the determination of the magnetic field (9×10−3/cos θ Gauss), and the SiO systemic velocity (−1 ± 2 km/s).
The Wisconsin Plasma Astrophysics Laboratory (WiPAL) is a flexible user facility designed to study a range of astrophysically relevant plasma processes as well as novel geometries that mimic astrophysical systems. A multi-cusp magnetic bucket constructed from strong samarium cobalt permanent magnets now confines a
, fully ionized, magnetic-field-free plasma in a spherical geometry. Plasma parameters of
provide an ideal testbed for a range of astrophysical experiments, including self-exciting dynamos, collisionless magnetic reconnection, jet stability, stellar winds and more. This article describes the capabilities of WiPAL, along with several experiments, in both operating and planning stages, that illustrate the range of possibilities for future users.
We conducted infrared spectroscopic observations of bright stars in the direction of the molecular clouds W33 and GMC G23.3 − 0.3. We compared stellar spectro-photometric distances with parallactic distances to these regions, and we were able to assess the association of the detected massive stars with these molecular complexes. The spatial and temporal distributions of the detected stars enabled us to locate sources of ionizing radiation and to gather precise information on the star formation history of these clouds. The studied clouds present different distributions of massive stars.