Studies on active and passive tobacco smoking and breast cancer have found inconsistent results. A meta-analysis of observational studies on tobacco smoking and breast cancer occurrence was conducted ...based on systematic searches for studies with retrospective (case–control) and prospective (cohort) designs. Eligible studies were identified, and relative risk measurements were extracted for active and passive tobacco exposures. Random-effects meta-analyses were used to compute summary relative risks (SRR). Heterogeneity of results between studies was evaluated using the (
I
2
) statistics. For ever active smoking, in 27 prospective studies, the SRR for breast cancer was 1.10 (95 % CI 1.09–1.12) with no heterogeneity (
I
2
= 0 %). In 44 retrospective studies, the SRR was 1.08 (95 % CI 1.02–1.14) with high heterogeneity (
I
2
= 59 %). SRRs for current active smoking were 1.13 (95 % CI 1.09–1.17) in 27 prospective studies and 1.08 (95 % CI 0.97–1.20) in 22 retrospective studies. The results were stable across different subgroup analyses, notably pre/post-menopause, alcohol consumption adjustments, including/excluding passive smokers from the referent group. For ever passive smoking, in 11 prospective studies, the SRR for breast cancer was 1.07 (95 % CI 1.02–1.13) with no heterogeneity (
I
2
= 1 %). In 20 retrospective studies, the SRR was 1.30 (95 % CI 1.10–1.54) with high heterogeneity (
I
2
= 74 %). Too few prospective studies were available for meaningful subgroup analyses. There is consistent evidence for a moderate increase in the risk of breast cancer in women who smoke tobacco. The evidence for a moderate increase in risk with passive smoking is more substantial than a few years ago.
This research investigated how an intangible component of consumer welfare can derive from the presence of store brands in durable-product categories. The objective was to explore the degree to which ...consumers can more reliably depend on price as an accurate indicator of quality in those product categories in which store brands are present. When a strong price-quality relationship exists, consumers may confidently choose a given level of quality chiefly on the basis of price. The focal measure was the correlation between price and quality, computed separately for those categories in which only national brands were present and for those categories in which both store brands and national brands were present. Examination of the price and quality of 14,234 individual brands from the U.S. and other countries tested by Consumer Reports revealed that when store brands were present the strength of the relationship between price and quality exceeded the strength of the respective relationship when store brands were absent. Counterfactual simulations confirmed the relationship.
Context
Every diagnosis involves an act of decision making, which requires proper evaluation of information. However, even seemingly objective information can require interpretation, often without ...our conscious awareness. In this cross‐cutting edge article we describe the phenomenon of leader‐driven information distortion (ID) and its implications for medical education.
Information distortion
Recent research indicates that one threat to good decisions is a biased interpretation of information to favour one alternative course of action over another. Once an alternative emerges as a leader during a decision there is a strong tendency to evaluate subsequent information as supporting that option. This can occur when deciding between two competing diagnoses. It is particularly a concern if diagnostic tests provide potentially ambiguous results. This leader‐driven ID is pre‐decisional in nature, in that it develops during a decision and involves the interpretation of information available prior to the final decision or diagnosis, with different interpretations possible depending on whichever alternative is the leader. Studies reveal that the distortion bias is pervasive in decisions, and that awareness of the act of distortion is low in decision makers.
Application to medical education
Empirical research has confirmed the presence of leader‐driven ID in hypothetical diagnoses made by physicians. ID creates two threats to medical decisions: First, it can make a diagnosis sticky in that it is resistant to being overturned by contradictory information. Second, it can promote unwarranted certainty in a diagnosis. The outcome may be premature closure, unnecessary testing or incorrect treatment, resulting in delayed or missed diagnoses.
Methods
This paper summarises research related to leader‐driven ID in medical and professional decisions and discusses various approaches directed towards reducing ID. A framework and language are provided for thinking about and discussing ID in medical decisions and medical education. Courses of action for mitigating the effects of ID are suggested.
Boyle and Purdon review what is known about leader‐driven information distortion, a decision‐bias that can lead physicans to premature closure, unnecessary testing, incorrect treatment, or overconfidence resulting in delayed or missed diagnoses.
Summary The burden of cancer is growing, and the disease is becoming a major economic expenditure for all developed countries. In 2008, the worldwide cost of cancer due to premature death and ...disability (not including direct medical costs) was estimated to be US$895 billion. This is not simply due to an increase in absolute numbers, but also the rate of increase of expenditure on cancer. What are the drivers and solutions to the so-called cancer-cost curve in developed countries? How are we going to afford to deliver high quality and equitable care? Here, expert opinion from health-care professionals, policy makers, and cancer survivors has been gathered to address the barriers and solutions to delivering affordable cancer care. Although many of the drivers and themes are specific to a particular field—eg, the huge development costs for cancer medicines—there is strong concordance running through each contribution. Several drivers of cost, such as over-use, rapid expansion, and shortening life cycles of cancer technologies (such as medicines and imaging modalities), and the lack of suitable clinical research and integrated health economic studies, have converged with more defensive medical practice, a less informed regulatory system, a lack of evidence-based sociopolitical debate, and a declining degree of fairness for all patients with cancer. Urgent solutions range from re-engineering of the macroeconomic basis of cancer costs (eg, value-based approaches to bend the cost curve and allow cost-saving technologies), greater education of policy makers, and an informed and transparent regulatory system. A radical shift in cancer policy is also required. Political toleration of unfairness in access to affordable cancer treatment is unacceptable. The cancer profession and industry should take responsibility and not accept a substandard evidence base and an ethos of very small benefit at whatever cost; rather, we need delivery of fair prices and real value from new technologies.
A
bstract
We present a direct lattice QCD calculation of the
x
-dependence of the pion distribution amplitude (DA), which is performed using the quasi-DA in large momentum effective theory on a ...domain-wall fermion ensemble at physical quark masses and spacing
a
≈ 0.084 fm. The bare quais-DA matrix elements are renormalized in the hybrid scheme and matched to
MS
¯
with a subtraction of the leading renormalon in the Wilson-line mass. For the first time, we include threshold resummation in the perturbative matching onto the light-cone DA, which resums the large logarithms in the soft gluon limit at next-to-next-to-leading log. The resummed results show controlled scale-variation uncertainty within the range of momentum fraction
x
∈ 0.25, 0.75 at the largest pion momentum
P
z
≈ 1
.
85 GeV. In addition, we apply the same analysis to quasi-DAs from a highly-improved-staggered-quark ensemble at physical pion mass and
a
= 0
.
076 fm. By comparison we find with 2
σ
confidence level that the DA obtained from chiral fermions is flatter and lower near
x
= 0
.
5.
Mucosal human papillomaviruses (HPV) are the cause of cervical cancer and likely a subset of head and neck squamous cell carcinomas
(HNSCC), yet the global prevalence and type distribution of HPV in ...HNSCC remains unclear. We systematically reviewed published
studies of HNSCC biopsies that employed PCR-based methods to detect and genotype HPV to describe the prevalence and type distribution
of HPV by anatomic cancer site. Geographic location and study size were investigated as possible sources of variability. In
the 5,046 HNSCC cancer specimens from 60 studies, the overall HPV prevalence was 25.9% 95% confidence interval (95% CI),
24.7-27.2. HPV prevalence was significantly higher in oropharyngeal SCCs (35.6% of 969; 95% CI, 32.6-38.7) than oral SCCs
(23.5% of 2,642; 95% CI, 21.9-25.1) or laryngeal SCCs (24.0% of 1,435; 95% CI, 21.8-26.3). HPV16 accounted for a larger majority
of HPV-positive oropharyngeal SCCs (86.7%; 95% CI, 82.6-90.1) compared with HPV-positive oral SCCs (68.2%; 95% CI, 64.4-71.9)
and laryngeal SCCs (69.2%; 95% CI, 64.0-74.0). Conversely, HPV18 was rare in HPV-positive oropharyngeal SCCs (2.8%; 95% CI,
1.3-5.3) compared with other head and neck sites 34.1% (95% CI, 30.4-38.0) of oral SCCs and 17.0% (95% CI, 13.0-21.6) of
laryngeal SCCs. Aside from HPV16 and HPV18, other oncogenic HPVs were rarely detected in HNSCC. Tumor site–specific HPV prevalence
was higher among studies from North America compared with Europe and Asia. The high HPV16 prevalence and the lack of HPV18
in oropharyngeal compared with other HNSCCs may point to specific virus-tissue interactions. Small sample size and publication
bias complicate the assessment of the prevalence of HPV in head and neck sites beyond the oropharynx.
The IBM Blue Gene/Q Compute Chip Haring, Ruud A.; Ohmacht, Martin; Fox, Thomas W. ...
IEEE MICRO,
2012-March-April, 2012-03-00, 20120301, Letnik:
32, Številka:
2
Journal Article
Recenzirano
Blue Gene/Q aims to build a massively parallel high-performance computing system out of power-efficient processor chips, resulting in power-efficient, cost-efficient, and floor-space- efficient ...systems. Focusing on reliability during design helps with scaling to large systems and lowers the total cost of ownership. This article examines the architecture and design of the Compute chip, which combines processors, memory, and communication functions on a single chip.
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