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In the "problem-solving environments" that will one day free scientists and engineers from many algorithmic and computing details, computational intelligence techniques such as neural networks and fuzzy logic can help automate the choice of the best solution methods. Classifying the problems, illustrated in this article by using partial differential equations (PDEs) as an example, is a first step.
By tailoring capillary interactions at a fluid–fluid interface, a hierarchical two-dimensional self-assembly of hexagonal millimeter-sized poly(dimethylsiloxane) plates has been demonstrated (see picture). The strength and direction of capillary forces between plates was controlled by patterning of the surfaces of the plates to be hydophobic or hydrophilic. The thick lines indicate hydrophobic faces whose mutual attraction forms the basis of capillarity.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPseudorotation in arylbis(4,4'-dimethyl-2,2'-biphenylylene)phosphoranesGeorge M. Whitesides, Michael Eisenhut, and William M. BuntingCite this: J. Am. Chem. Soc. 1974, 96, 17, 5398–5407Publication Date (Print):August 1, 1974Publication History Published online1 May 2002Published inissue 1 August 1974https://pubs.acs.org/doi/10.1021/ja00824a014https://doi.org/10.1021/ja00824a014research-articleACS PublicationsRequest reuse permissionsArticle Views1020Altmetric-Citations45LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
OBJECTIVE— To examine the associations between common variations in the IL6R gene and circulating interleukin (IL)-6 levels and diabetes risk. RESEARCH DESIGN AND METHODS— We determined 10 linkage disequilibrium (LD)-tagging single nucleotide polymorphisms (SNPs) (SNP1 to SNP10) for the IL6R gene in a nested case-control study of 672 diabetic and 1,058 healthy European Caucasian women (IL-6 levels were measured in a subgroup of 1,348 women). RESULTS— In both control and diabetic patients, polymorphisms within an LD block spanning ∼42 kb were significantly associated with plasma IL-6 levels. A missense variant SNP7 in exon 9 (rs8192284, Asp358Ala) showed the strongest association (P = 0.0005 in control and P = 0.004 in case subjects). The corresponding false-discovery rates, which accounts for multiple testing, were 0.008 and 0.02, respectively. We inferred five common haplotypes to capture 94% allele variance of the LD block using SNP5, -7, -8, -9, and -10. Compared with the most common haplotype 12111 (one codes the common and two codes the minor alleles), haplotypes 11211 [difference in log(IL-6) = −0.11 (95% CI −0.23 to −0.01); P = 0.01] and 21122 (−0.15 [−0.27 to −0.03]; P = 0.01) were associated with significantly lower IL-6 levels (global test, P = 0.01). However, IL6R genotypes were not significantly associated with the risk of type 2 diabetes. CONCLUSIONS— IL6R genetic variations, especially SNP7 (rs8192284, Asp358Ala), were significantly associated with plasma IL-6 levels but not with diabetes risk in women. The strong associations between IL6R genetic variability and IL-6 concentrations deserve further investigation.
The origin of unsteady glacier motions, an area to which Robert M. McMeeking contributed significantly [1,2], is of interest for assessing stability of major ice sheets (Greenland, Antarctica). Meltwater and its pressure p at the bed of glaciers are known to have major influence on flow. Our work [3,4] focuses on outburst under-flooding of an ice sheet, as a means of delivering highly pressurized water to its bed, transiently with p > o (= ice overburden pressure). The process is viewed as a turbulently driven hydraulic fracture along the ice/bed interface. Such can result [5] when the glacier dams a rising lake, or from geothermal heating of a sub-glacial lake. The particular scenario we address is, instead, rapid drainage into the ice of a large surficial meltwater lake, like recently documented in Greenland [6] during mid-summer. This first involves Weertman gravitationally driven hydraulic cracking from the lake to the bed, and then rapid spreading of water along the bed, initially as a high-p sheet flow. We compare modeling to results of the Greenland study [6], for which a 0.043 km 3 lake disappeared into the ice, mostly within 1.5 hr. The lake drainage rate in that case, and the ~3 km length, parallel to the glacier surface, of a crevasse/moulin system along which drainage apparently occurred, suggest that in the rapid early phases of the underflooding the Reynolds number (based on basal fracture opening h and thickness-averaged flow speed U along it) was of order 10 6 . Accordingly, we adopted a Manning-Strickler-Nikuradse description of wall shear stress in the rough turbulent range to relate U(x,t), h(x,t), p(x,t), and the wall roughness scale k, where x is the coordinate in the direction of fracture propagation. We further assumed linear elastic response of ice and bed, and (for the large fracture propagation lengths of interest) negligible KIc . By extending studies like in [7,8] to that rough turbulent flow range, we have thus solved approximately the plane strain version of the hydraulic fracture problem when the basal crack length 2L is modest compared to ice sheet thickness H (i.e., for a crack in an unbounded body, subject to crack face pressure p o ). We outline those results here and will, in the presentation, report some preliminary improvements on them in current work to account for the range L/H of order 1 and larger, often a practically interesting one [4-6], by explicitly accounting for a nearby free surface. That adopts the approach of [9] to numerically relate the h(x,t) and p(x, t ) o distributions. To fully solve the problem for the rate of fracture propagation, and volume storage of meltwater within the fracture, the distributions must also be constrained to satisfy the governing fluid equations (analogously to [10], but for turbulent rather than laminar flow). Those fluid equations, to be solved on – L(t) 0) (hU )
Sugar-sweetened beverages (SSBs) have little nutritional value and a robust body of evidence has linked the intake of SSBs to weight gain and risk of type 2 diabetes (T2D), cardiovascular disease (CVD), and some cancers. Metabolic Syndrome (MetSyn) is a clustering of risk factors that precedes the development of T2D and CVD; however, evidence linking SSBs to MetSyn is not clear. To make informed recommendations about SSBs, new evidence needs to be considered against existing literature. This review provides an update on the evidence linking SSBs and cardiometabolic outcomes including MetSyn. Findings from prospective cohort studies support a strong positive association between SSBs and weight gain and risk of T2D and coronary heart disease (CHD), independent of adiposity. Associations with MetSyn are less consistent, and there appears to be a sex difference with stroke with greater risk in women. Findings from short-term trials on metabolic risk factors provide mechanistic support for associations with T2D and CHD. Conclusive evidence from cohort studies and trials on risk factors support an etiologic role of SSB in relation to weight gain and risk of T2D and CHD. Continued efforts to reduce intake of SSB should be encouraged to improve the cardiometabolic health of individuals and populations.
