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R-MAT (for Recursive MATrix) is a simple, widely used model for generating graphs with a power law degree distribution, a small diameter, and communitys structure. It is particularly attractive for generating very large graphs because edges can be generated independently by an arbitrary number of processors. However, current R-MAT generators need time logarithmic in the number of nodes for generating an edge— constant time for generating one bit at a time for node IDs of the connected nodes. We achieve constant time per edge by precomputing pieces of node IDs of logarithmic length. Using an alias table data structure, these pieces can then be sampled in constant time. This simple technique leads to practical improvements by an order of magnitude. This further pushes the limits of attainable graph size and makes generation overhead negligible in most situations.
Post-operative severe vascular stenosis and proliferating endothelial tissue lead to severe circulatory disorders and impair organ perfusion. Bioabsorbable magnesium scaffolds may help to overcome these obstructions without leaving obstructing stent material. We analyse their role in the treatment of vascular stenosis in infants.
Since 2016, 15 magnesium scaffolds with a diameter of 3.5 mm were implanted in 9 patients aged 15 days to 7.6 years. Eight scaffolds were implanted in pulmonary venous restenoses, five in pulmonary arterial stenosis including one in-stent stenosis, one into a stenotic brachiocephalic artery, and one in a recurrent innominate vein thrombosis.
All patients clinically improved after the implantation of a scaffold. The magnesium scaffolds lost integrity after 30–48 days (mean 42 days). The innominate vein thrombosed early, while all other vessels remained open. Two patients died after 1.3 and 14 weeks not related to the scaffolds. Five patients needed further balloon dilations or stent implantations after the scaffold had fractured. At first recatheterisation after in mean 2.5 months, the mean minimum/maximum diameter in relation to the scaffold’s original diameter was 89%/99% in the arterial implantations (n = 6) and 66%/77% in the pulmonary venous implantations.
The magnesium scaffolds can be used as a bridging solution to treat severe vascular stenosis in different locations. Restenosis can occur after degradation and make further interventions necessary, but neither vessel growth nor further interventions are hindered by stent material. Larger diameters may improve therapeutic options.
This research communication addresses the hypothesis that Southeast dairy producers' self-reported bulk tank somatic cell count (BTSCC) was associated with producers' response to three statements (1) ‘a troublesome thing about mastitis is the worries it causes me,’ (2) ‘a troublesome thing about mastitis is that cows suffer,’ and (3) ‘my broad goals include taking good care of my cows and heifers.’ Surveys were mailed to producers in Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia (29% response rate, N = 596; final analysis N = 574), as part of a larger survey to assess Southeastern dairy producers' opinions related to BTSCC. Surveys contained 34 binomial (n = 9), Likert scale (n = 7), and descriptive (n = 18) statements targeted at producer self-assessment of herd records, management practices, and BTSCC. Statements 1 and 2 were assessed on a 5-point Likert scale from ‘strongly disagree’ to ‘strongly agree.’ Statement 3 was assessed on a 5-point Likert scale from ‘very unimportant’ to ‘very important.’ Reported mean BTSCC for all participants was 254 500 cells/ml. Separate univariable logistic regressions using generalized linear mixed models (SAS 9.4, Cary, NC, USA) with a random effect of farm, were performed to determine if BTSCC was associated with probability for a producer's response to statements. If BTSCC was significant, forward manual addition was performed until no additional variables were significant (P ≤ 0.05), but included BTSCC, regardless of significance. Bulk tank somatic cell count was associated with ‘a troublesome thing about mastitis is the worries it causes me,’ but not with Statements 2 or 3. This demonstrates that >75% of Southeastern dairy producers are concerned with animal care and cow suffering, regardless of BTSCC. Understanding Southeast producers' emphasis on cow care is necessary to create targeted management tools for herds with elevated BTSCC.
The Upper Cretaceous Kanguk Formation of the Sverdrup Basin, Canadian Arctic Islands, contains numerous diagenetically altered volcanic ash layers (bentonites). Eleven bentonites were sampled from an outcrop section on Ellesmere Island for U–Pb zircon secondary ion mass spectrometry dating and whole-rock geochemical analysis. Two distinct types of bentonite are identified from the geochemical data. Relatively thick (0.1 to 5 m) peralkaline rhyolitic to trachytic bentonites erupted in an intraplate tectonic setting. These occur throughout the upper Turonian to lower Campanian (c. 92–83 Ma) outcrop section and are likely associated with the alkaline phase of the High Arctic Large Igneous Province. Two thinner (<5 cm) subalkaline dacitic to rhyolitic bentonites of late Turonian to early Coniacian age (c. 90–88 Ma) are also identified. The geochemistry of these bentonites is consistent with derivation from volcanoes within an active continental margin tectonic setting. The lack of nearby potential sources of subalkaline magmatism, together with the thinner bed thickness of the subalkaline bentonites and the small size of zircon phenocrysts therein (typically 50–80 μm in length) are consistent with a more distal source area. The zircon U–Pb age and whole-rock geochemistry of these two subalkaline bentonites correlate with an interval of intense volcanism in the Okhotsk–Chukotka Volcanic Belt, Russia. It is proposed that during late Turonian to early Coniacian times intense volcanism within the Okhotsk–Chukotka Volcanic Belt resulted in widespread volcanic ash dispersal across Arctic Alaska and Canada, reaching as far east as the Sverdrup Basin, more than 3000 km away.
There is no established methodology to assess the feasibility of medicine price data sources. Against this backdrop, a framework to guide the selection of most appropriate price data sources for pharmacoeconomic research has been developed.
A targeted literature review was carried out. Dimensions discussed in literature as relevant for medicine price comparisons and practical experience of the authors in medicine price studies informed the conceptional work of the framework development. A draft version of the framework was reviewed by peer pricing experts. The feasibility of the framework was tested in case studies.
According to the developed framework (called Re-ADAPT), a medicine price data source should meet the following criteria: reliability and sustainability; accessibility at a cost that users can afford; provision of medicine price information at the date(s) required; information for the defined geographic area, or at least in a representative way; coverage of the pharmaceuticals and at the price type(s) required. Easy handling and provision of additional information were defined as supportive assets of candidate data sources (secondary criteria). The case studies confirmed the feasibility of the Re-ADAPT framework. In some cases, however, it can be difficult to disentangle assessment criteria (particularly geographic area, scope of pharmaceuticals and price types) for separate consideration, given their interlinkage.
While selection of the most appropriate data sources will remain a challenge, the Re-ADAPT framework aims to provide practical guidance and thus contribute to a more careful, balanced, and evidence-based selection of data sources for medicine price studies.
Physical activity (PA) may be therapeutic for people with severe mental illness (SMI) who generally have low PA and experience numerous life style-related medical complications. We conducted a meta-review of PA interventions and their impact on health outcomes for people with SMI, including schizophrenia-spectrum disorders, major depressive disorder (MDD) and bipolar disorder. We searched major electronic databases until January 2018 for systematic reviews with/without meta-analysis that investigated PA for any SMI. We rated the quality of studies with the AMSTAR tool, grading the quality of evidence, and identifying gaps, future research needs and clinical practice recommendations. For MDD, consistent evidence indicated that PA can improve depressive symptoms versus control conditions, with effects comparable to those of antidepressants and psychotherapy. PA can also improve cardiorespiratory fitness and quality of life in people with MDD, although the impact on physical health outcomes was limited. There were no differences in adverse events versus control conditions. For MDD, larger effect sizes were seen when PA was delivered at moderate-vigorous intensity and supervised by an exercise specialist. For schizophrenia-spectrum disorders, evidence indicates that aerobic PA can reduce psychiatric symptoms, improves cognition and various subdomains, cardiorespiratory fitness, whilst evidence for the impact on anthropometric measures was inconsistent. There was a paucity of studies investigating PA in bipolar disorder, precluding any definitive recommendations. No cost effectiveness analyses in any SMI condition were identified. We make multiple recommendations to fill existing research gaps and increase the use of PA in routine clinical care aimed at improving psychiatric and medical outcomes.
Chip-package interaction (CPI) and the related thermomechanical stress in microchips increase the risk of failure in on-chip interconnect stacks, caused by delamination along Cu/dielectrics interfaces (adhesive failure) and fracture in dielectrics (cohesive failure). High-resolution transmission X-ray microscopy (TXM) is a unique technique to image crack propagation in on-chip interconnect stacks. The visualization of crack evolution in Cu/low-k Backend-of-Line (BEoL) structures is demonstrated using an experimental setup which combines high-resolution X-ray imaging with mechanical loading. The application of an indenter manipulator at the TXM beamline of the synchrotron radiation source BESSY II provides an unprecedented level of details on the fracture behavior of microchips. This in-situ experiment allows to identify the weakest layers and interfaces and to evaluate the robustness of the BEoL stack against CPI.