1,453 research outputs found
Recommended from our members
Reactivity to sustainability metrics: A configurational study of motivation and capacity
Previous research on reactivity – defined as changing organisational behaviour to better conform to the criteria of measurement in response to being measured – has found significant variation in company responses towards sustainability metrics. We propose that reactivity is driven by dialogue, motivation and capacity in a configurational way. Empirically, we use fuzzy set Qualitative Comparative Analysis (fsQCA) to analyse company responses to the sustainability index FTSE4Good. We find evidence of complimentary and substitute effects between motivation and capacity. Based on these effects we develop a typology of reactivity to sustainability metrics, which also theorises the use of metrics as tools for performance feedback and the building of calculative capacity. We show that when reactivity is studied configurationally, we can identify previously underacknowledged types of responses. We discuss the theoretical and practical implications for studying and using sustainability metrics as governance tools for responsible behaviour
Dual gauge field theory of quantum liquid crystals in two dimensions
We present a self-contained review of the theory of dislocation-mediated
quantum melting at zero temperature in two spatial dimensions. The theory
describes the liquid-crystalline phases with spatial symmetries in between a
quantum crystalline solid and an isotropic superfluid: quantum nematics and
smectics. It is based on an Abelian-Higgs-type duality mapping of phonons onto
gauge bosons ("stress photons"), which encode for the capacity of the crystal
to propagate stresses. Dislocations and disclinations, the topological defects
of the crystal, are sources for the gauge fields and the melting of the crystal
can be understood as the proliferation (condensation) of these defects, giving
rise to the Anderson-Higgs mechanism on the dual side. For the liquid crystal
phases, the shear sector of the gauge bosons becomes massive signaling that
shear rigidity is lost. Resting on symmetry principles, we derive the
phenomenological imaginary time actions of quantum nematics and smectics and
analyze the full spectrum of collective modes. The quantum nematic is a
superfluid having a true rotational Goldstone mode due to rotational symmetry
breaking, and the origin of this 'deconfined' mode is traced back to the
crystalline phase. The two-dimensional quantum smectic turns out to be a
dizzyingly anisotropic phase with the collective modes interpolating between
the solid and nematic in a non-trivial way. We also consider electrically
charged bosonic crystals and liquid crystals, and carefully analyze the
electromagnetic response of the quantum liquid crystal phases. In particular,
the quantum nematic is a real superconductor and shows the Meissner effect.
Their special properties inherited from spatial symmetry breaking show up
mostly at finite momentum, and should be accessible by momentum-sensitive
spectroscopy.Comment: Review article, 137 pages, 32 figures. Accepted versio
Переяславська рада у сучасній російській навчальній літературі
Topological band-insulators (TBIs) represent a new class of quantum materials that in the presence of time-reversal symmetry (TRS) feature an insulating bulk bandgap together with metallic edge or surface states protected by a Z 2 topological invariant [1,2,3,4]. Recently, an extra layer in this Z 2 classification of TBIs has been uncovered by considering the crystal symmetries [5]. Dislocation lines being the unique topological defects related to the lattice translations play a fundamental role in this endeavor. We here elucidate the general rule governing their response in three-dimensional TBIs and uncover their role in this classification. According to that K-b-t rule, the lattice topology, represented by dislocation lines oriented in the direction t with the Burgers vector b , conspires with the electronic-band topology, characterized by the band-inversion momentum K inv , to produce gapless propagating modes along these line defects, which were discovered in Ref. [6]. For sufficiently symmetric crystals, this conspiracy leads to the topologically-protected metallic states inside the dislocation loops, which could also be important for applications. Finally, these findings are experimentally consequential as dislocation defects are ubiquitous in the real crystals
Efficiency of energy transfer, but not external work, is maximized in stunned myocardium
There is no evidence regarding the effect of stunning on maximization of
regional myocardial external work (EW) or efficiency of energy transfer
(EET) in relation to regional afterload (end-systolic stress, sigma(es)).
To that end, we studied these relationships in both the left anterior
descending coronary artery (LADCA) and left circumflex coronary artery
regions in anesthetized, open-chest pigs before and after LADCA stunning.
In normal myocardium, EET vs. sigma(es) was maximal at 75.4 (69.7-81.0)%,
whereas EW vs. sigma(es) was submaximal at 12.0 (6.61-17.3) x 10(2)
J/m(3). Increasing sigma(es) increased EW by 18 (10-27)%. Regional
myocardial stunning decreased EET (27%) and EW (36%) and caused the
myocardium to operate both at maximal EW (EW(max)) and at maximal EET
(EET(max)). EET and EW became also more sensitive to changes in sigma(es).
In the nonstunned region the situation remained unchanged. Combining the
data from before and after stunning, both EW(max) and EET(max) displayed a
positive relationship with contractility. In conclusion, the normal
regional myocardium operated at maximal EET rather than at maximal EW.
Therefore, additional EW could be recruited by increasing regional
afterload. After myocardial stunning, the myocardium operated at both
maximal EW and maximal EET, at the cost of increased afterload
sensitivity. Contractility was a major determinant of this shift
Validity of the Dutch modified painDETECT questionnaire (MPDQ-NL) for patients with hip or knee osteoarthritis
Comparative validation of quantitative coronary angiography systems. Results and implications from a multicenter study using a standardized approach.
Background Computerized quantitative coronary angiography (QCA) has fundamentally altered our approach to the assessment of coronary interventional techniques and strategies aimed at the prevention of recurrence and progression of stenosis. It is essential, therefore, that the performance of QCA systems, upon which much of our scientific understanding has become integrally dependent, is evaluated in an objective and uniform manner.
Methods and Results We validated 10 QCA systems at core laboratories in North America and Europe. Cine films were made of phantom stenoses of known diameter (0.5 to 1.9 mm)
Fat Mass and Obesity-Associated Gene (FTO) in Eating Disorders: Evidence for Association of the rs9939609 Obesity Risk Allele with Bulimia nervosa and Anorexia nervosa
Objective: The common single nucleotide polymorphism (SNP) rs9939609 in the fat mass and obesity-associated gene (FTO) is associated with obesity. As genetic variants associated with weight regulation might also be implicated in the etiology of eating disorders, we evaluated whether SNP rs9939609 is associated with bulimia nervosa (BN) and anorexia nervosa (AN). Methods: Association of rs9939609 with BN and AN was assessed in 689 patients with AN, 477 patients with BN, 984 healthy non-population-based controls, and 3,951 population-based controls (KORA-S4). Based on the familial and premorbid occurrence of obesity in patients with BN, we hypothesized an association of the obesity risk A-allele with BN. Results: In accordance with our hypothesis, we observed evidence for association of the rs9939609 A-allele with BN when compared to the non-population-based controls (unadjusted odds ratio (OR) = 1.142, one-sided 95% confidence interval (CI) 1.001-infinity; one-sided p = 0.049) and a trend in the population-based controls (OR = 1.124, one-sided 95% CI 0.932-infinity; one-sided p = 0.056). Interestingly, compared to both control groups, we further detected a nominal association of the rs9939609 A-allele to AN (OR = 1.181, 95% CI 1.027-1.359, two-sided p = 0.020 or OR = 1.673, 95% CI 1.101-2.541, two-sided p = 0.015,). Conclusion: Our data suggest that the obesity-predisposing FTO allele might be relevant in both AN and BN. Copyright (C) 2012 S. Karger GmbH, Freibur
- …
