Laboratory observations of slow earthquakes and the spectrum of tectonic fault slip modes

Slow earthquakes represent an important conundrum in earthquake physics. While regular earthquakes are catastrophic events with rupture velocities governed by elastic wave speed, the processes that underlie slow fault slip phenomena, including recent discoveries of tremor, slow-slip and low-frequency earthquakes, are less understood. Theoretical models and sparse laboratory observations have provided insights, but the physics of slow fault rupture remain enigmatic. Here we report on laboratory observations that illuminate the mechanics of slow-slip phenomena. We show that a spectrum of slow-slip behaviours arises near the threshold between stable and unstable failure, and is governed by frictional dynamics via the interplay of fault frictional properties, effective normal stress and the elastic stiffness of the surrounding material. This generalizable frictional mechanism may act in concert with other hypothesized processes that damp dynamic ruptures, and is consistent with the broad range of geologic environments where slow earthquakes are observed

Bone Marrow-Derived Multipotent Stromal Cells Attenuate Inflammation in Obliterative Airway Disease in Mouse Tracheal Allografts

Obliterative bronchiolitis (OB) remains the most significant cause of death in long-term survival of lung transplantation. Using an established murine heterotopic tracheal allograft model, the effects of different routes of administration of bone marrow-derived multipotent stromal cells (MSCs) on the development of OB were evaluated. Tracheas from BALB/c mice were implanted into the subcutaneous tissue of major histocompatibility complex- (MHC-) disparate C57BL/6 mice. At the time of transplant, bone marrow-derived MSCs were administered either systemically or locally or via a combination of the two routes. The allografts were explanted at various time points after transplantation and were evaluated for epithelial integrity, inflammatory cell infiltration, fibrosis, and luminal obliteration. We found that the most effective route of bone marrow-derived MSC administration is the combination of systemic and local delivery. Treatment of recipient mice with MSCs suppressed neutrophil, macrophage, and T-cell infiltration and reduced fibrosis. These beneficial effects were observed despite lack of significant MSC epithelial engraftment or new epithelial cell generation. Our study suggests that optimal combination of systemic and local delivery of MSCs may ameliorate the development of obliterative airway disease through modulation of immune response

Transverse phase-locking in fully frustrated Josephson junction arrays: a new type of fractional giant steps

We study, analytically and numerically, phase locking of driven vortex lattices in fully-frustrated Josephson junction arrays at zero temperature. We consider the case when an ac current is applied {\it perpendicular} to a dc current. We observe phase locking, steps in the current-voltage characteristics, with a dependence on external ac-drive amplitude and frequency qualitatively different from the Shapiro steps, observed when the ac and dc currents are applied in parallel. Further, the critical current increases with increasing transverse ac-drive amplitude, while it decreases for longitudinal ac-drive. The critical current and the phase-locked current step width, increase quadratically with (small) amplitudes of the ac-drive. For larger amplitudes of the transverse ac-signal, we find windows where the critical current is hysteretic, and windows where phase locking is suppressed due to dynamical instabilities. We characterize the dynamical states around the phase-locking interference condition in the $IV$ curve with voltage noise, Lyapunov exponents and Poincar\'e sections. We find that zero temperature phase-locking behavior in large fully frustrated arrays is well described by an effective four plaquette model.Comment: 12 pages, 11 figure

Capacity building for evidence-based decision making in local health departments: Scaling up an effective training approach

Abstract Background There are few studies describing how to scale up effective capacity-building approaches for public health practitioners. This study tested local-level evidence-based decision making (EBDM) capacity-building efforts in four U.S. states (Michigan, North Carolina, Ohio, and Washington) with a quasi-experimental design. Methods Partners within the four states delivered a previously established Evidence-Based Public Health (EBPH) training curriculum to local health department (LHD) staff. They worked with the research team to modify the curriculum with local data and examples while remaining attentive to course fidelity. Pre- and post-assessments of course participants (n = 82) and an external control group (n = 214) measured importance, availability (i.e., how available a skill is when needed, either within the skillset of the respondent or among others in the agency), and gaps in ten EBDM competencies. Simple and multiple linear regression models assessed the differences between pre- and post-assessment scores. Course participants also assessed the impact of the course on their work. Results Course participants reported greater increases in the availability, and decreases in the gaps, in EBDM competencies at post-test, relative to the control group. In adjusted models, significant differences (p < 0.05) were found in ‘action planning,’ ‘evaluation design,’ ‘communicating research to policymakers,’ ‘quantifying issues (using descriptive epidemiology),’ and ‘economic evaluation.’ Nearly 45% of participants indicated that EBDM increased within their agency since the training. Course benefits included becoming better leaders and making scientifically informed decisions. Conclusions This study demonstrates the potential for improving EBDM capacity among LHD practitioners using a train-the-trainer approach involving diverse partners. This approach allowed for local tailoring of strategies and extended the reach of the EBPH course.http://deepblue.lib.umich.edu/bitstream/2027.42/109528/1/13012_2014_Article_124.pd

Single-vortex-induced voltage steps in Josephson-junction arrays

We have numerically and analytically studied ac+dc driven Josephson-junction arrays with a single vortex or with a single vortex-antivortex pair present. We find single-vortex steps in the voltage versus current characteristics (I-V) of the array. They correspond microscopically to a single vortex phase-locked to move a fixed number of plaquettes per period of the ac driving current. In underdamped arrays we find vortex motion period doubling on the steps. We observe subharmonic steps in both underdamped and overdamped arrays. We successfully compare these results with a phenomenological model of vortex motion with a nonlinear viscosity. The I-V of an array with a vortex-antivortex pair displays fractional voltage steps. A possible connection of these results to present day experiments is also discussed.Comment: 10 pages double sided with figures included in the text. To appear in Journal of Physics, Condensed Matte

Critical Exponents of the Fully Frustrated 2-D Xy Model

We present a detailed study of the critical properties of the 2-D XY model with maximal frustration in a square lattice. We use extensive Monte Carlo simulations to study the thermodynamics of the spin and chiral degrees of freedom, concentrating on their correlation functions. The gauge invariant spin-spin correlation functions are calculated close to the critical point for lattice sizes up to $240\times 240$; the chiral correlation functions are studied on lattices up to $96\times 96$. We find that the critical exponents of the spin phase transition are $\nu=0.3069$, and $\eta=0.1915$, which are to be compared with the unfrustrated XY model exponents $\nu=1/2$ and $\eta=0.25$. We also find that the critical exponents of the chiral transition are $\nu_{\chi}=0.875$, $2\beta=0.1936$, $2\gamma= 1.82$, and $2\gamma\>\prime=1.025$, which are different from the expected 2-D Ising critical exponents. The spin-phase transition occurs at $T_{U(1)}=0.446$ which is about 7\% above the estimated chiral critical temperature $T_{Z_{2}}= 0.4206$. However, because of the size of the statistical errors, it is difficult to decide with certainty whether the transitions occur at the same or at slightly different temperatures. Finally, the jump in the helicity modulus in the fully frustrated system is found to be about 23\% below the unfrustrated universal value. The most important consequence of these results is that the fully frustrated XY model appears to be in a novel universality class. Recent successful comparisons of some of these results with experimental data are also briefly discussed. (TO APPEAR IN PRB)Comment: 47 pages (PHYZZX

AIMD - A validated, simplified framework of interventions to promote and integrate evidence into health practices, systems, and policies

Background: Proliferation of terms describing the science of effectively promoting and supporting the use of research evidence in healthcare policy and practice has hampered understanding and development of the field. To address this, an international Terminology Working Group developed and published a simplified framework of interventions to promote and integrate evidence into health practices, systems, and policies. This paper presents results of validation work and a second international workgroup meeting, culminating in the updated AIMD framework [Aims, Ingredients, Mechanism, Delivery]. Methods: Framework validity was evaluated against terminology schemas (n = 51); primary studies (n = 37); and reporting guidelines (n = 10). Framework components were independently categorized as fully represented, partly represented, or absent by two researchers. Opportunities to refine the framework were systematically recorded. A meeting of the expanded international Terminology Working Group updated the framework by reviewing and deliberating upon validation findings and refinement proposals. Results: There was variation in representativeness of the components across the three types of literature, in particular for the component 'causal mechanisms'. Analysis of primary studies revealed that representativeness of this concept lowered from 92 to 68% if only explicit, rather than explicit and non-explicit references to causal mechanisms were included. All components were very well represented in reporting guidelines, however the level of description of these was lower than in other types of literature. Twelve opportunities were identified to improve the framework, 9 of which were operationalized at the meeting. The updated AIMD framework comprises four components: (1) Aims: what do you want your intervention to achieve and for whom? (2) Ingredients: what comprises the intervention? (3) Mechanisms: how do you propose the intervention will work? and (4) Delivery: how will you deliver the intervention? Conclusions: The draft simplified framework was validated with reference to a wide range of relevant literature and improvements have enhanced useability. The AIMD framework could aid in the promotion of evidence into practice, remove barriers to understanding how interventions work, enhance communication of interventions and support knowledge synthesis. Future work needs to focus on developing and testing resources and educational initiatives to optimize use of the AIMD framework in collaboration with relevant end-user groups

Study on COgnition and Prognosis in the Elderly (SCOPE)

Blood Press. 1999;8(3):177-83. Study on COgnition and Prognosis in the Elderly (SCOPE). Hansson L, Lithell H, Skoog I, Baro F, Bánki CM, Breteler M, Carbonin PU, Castaigne A, Correia M, Degaute JP, Elmfeldt D, Engedal K, Farsang C, Ferro J, Hachinski V, Hofman A, James OF, Krisin E, Leeman M, de Leeuw PW, Leys D, Lobo A, Nordby G, Olofsson B, Zanchetti A, et al. University of Uppsala, Department of Public Health, Sweden. Abstract The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multicentre, prospective, randomized, double-blind, parallel-group study designed to compare the effects of candesartan cilexetil and placebo in elderly patients with mild hypertension. The primary objective of the study is to assess the effect of candesartan cilexetil on major cardiovascular events. The secondary objectives of the study are to assess the effect of candesartan cilexetil on cognitive function and on total mortality, cardiovascular mortality, myocardial infarction, stroke, renal function, hospitalization, quality of life and health economics. Male and female patients aged between 70 and 89 years, with a sitting systolic blood pressure (SBP) of 160-179 mmHg and/or diastolic blood pressure (DBP) of 90-99 mmHg, and a Mini-Mental State Examination (MMSE) score of 24 or above, are eligible for the study. The overall target study population is 4000 patients, at least 1000 of whom are also to be assessed for quality of life and health economics data. After an open run-in period lasting 1-3 months, during which patients are assessed for eligibility and those who are already on antihypertensive therapy at enrolment are switched to hydrochlorothiazide 12.5 mg o.d., patients are randomized to receive either candesartan cilexetil 8 mg once daily (o.d.) or matching placebo o.d. At subsequent study visits, if SBP remains >160 mmHg, or has decreased by 85 mmHg, study treatment is doubled to candesartan cilexetil 16 mg o.d. or two placebo tablets o.d. Recruitment was completed in January 1999. At that time 4964 patients had been randomized. All randomized patients will be followed for an additional 2 years. If the event rate is lower than anticipated, the follow-up will be prolonged. PMID: 10595696 [PubMed - indexed for MEDLINE

Quantum Interference in Superconducting Wire Networks and Josephson Junction Arrays: Analytical Approach based on Multiple-Loop Aharonov-Bohm Feynman Path-Integrals

We investigate analytically and numerically the mean-field superconducting-normal phase boundaries of two-dimensional superconducting wire networks and Josephson junction arrays immersed in a transverse magnetic field. The geometries we consider include square, honeycomb, triangular, and kagome' lattices. Our approach is based on an analytical study of multiple-loop Aharonov-Bohm effects: the quantum interference between different electron closed paths where each one of them encloses a net magnetic flux. Specifically, we compute exactly the sums of magnetic phase factors, i.e., the lattice path integrals, on all closed lattice paths of different lengths. A very large number, e.g., up to $10^{81}$ for the square lattice, exact lattice path integrals are obtained. Analytic results of these lattice path integrals then enable us to obtain the resistive transition temperature as a continuous function of the field. In particular, we can analyze measurable effects on the superconducting transition temperature, $T_c(B)$, as a function of the magnetic filed $B$, originating from electron trajectories over loops of various lengths. In addition to systematically deriving previously observed features, and understanding the physical origin of the dips in $T_c(B)$ as a result of multiple-loop quantum interference effects, we also find novel results. In particular, we explicitly derive the self-similarity in the phase diagram of square networks. Our approach allows us to analyze the complex structure present in the phase boundaries from the viewpoint of quantum interference effects due to the electron motion on the underlying lattices.Comment: 18 PRB-type pages, plus 8 large figure

Study on COgnition and Prognosis in the Elderly (SCOPE): baseline characteristics

Blood Press. 2000;9(2-3):146-51. Study on COgnition and Prognosis in the Elderly (SCOPE): baseline characteristics. Hansson L, Lithell H, Skoog I, Baro F, Bánki CM, Breteler M, Castaigne A, Correia M, Degaute JP, Elmfeldt D, Engedal K, Farsang C, Ferro J, Hachinski V, Hofman A, James OF, Krisin E, Leeman M, de Leeuw PW, Leys D, Lobo A, Nordby G, Olofsson B, Opolski G, Prince M, Reischies FM. University of Uppsala, Department of Public Health, Clinical Hypertension Research, Sweden. Abstract The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multi-centre, prospective, randomized, double-blind, parallel-group study. The primary objective of SCOPE is to assess the effect of the angiotensin II type 1 (AT1) receptor blocker, candesartan cilexetil 8-16 mg once daily, on major cardiovascular events in elderly patients (70-89 years of age) with mild hypertension (DBP 90-99 and/or SBP 160-179 mmHg). The secondary objectives of the study are to test the hypothesis that antihypertensive therapy can prevent cognitive decline (as measured by the Mini Mental State Examination, MMSE) and dementia, and to assess the effect of therapy on total mortality, myocardial infarction (MI), stroke, renal function, and hospitalization. A total of 4964 patients from 15 participating countries were recruited during the randomization phase of SCOPE, exceeding the target population of 4000. The mean age of the patients at enrolment was 76 years, the ratio of male to female patients was approximately 1:2, and 52% of patients were already being treated with an antihypertensive agent at enrolment. The majority of patients (88%) were educated to at least primary school level. At randomization, mean sitting blood pressure values were SBP 166 mmHg and DBP 90 mmHg, and the mean MMSE score was 28. Previous cardiovascular disease in the study population included myocardial infarction (4%), stroke (4%) and atrial fibrillation (4%). Men, more often than women, had a history of previous MI, stroke and atrial fibrillation. A greater percentage of men were smokers (13% vs 6% in women) and had attended university (11% vs 3% of women). Of the randomized patients, 21% were 80 years of age. In this age group smoking was less common (4% vs 10% for 70-79-year-olds) and fewer had attended university (4% vs 7% for 70-79-year-olds). The incidence of MI was similar in both age groups. However, stroke and atrial fibrillation had occurred approximately twice as frequently in the older patients. The patients' mean age at baseline was similar in the participating countries, and most countries showed the approximate 1:2 ratio for male to female patients. There was also little inter-country variation in terms of mean SBP, DBP or MMSE score. However, there was considerable regional variation in the percentage of patients on therapy prior to enrolment. PMID: 10855739 [PubMed - indexed for MEDLINE