Opening the GATE : systems thinking from the global assistive technology alliance

Purpose: This paper describes international actions to collaborate in the assistive technology (AT) arena and provides an update of programmes supporting AT globally. Methods: The World Health Organisation (WHO) identifies the severe global uneven distribution of resources, expertise and extensive unmet need for AT, as well the optimistic substantial capability for innovations and developments in appropriate and sustainable AT design, development and delivery. Systems thinking and market shaping are identified as means to address these challenges and leverage the ingenuity and expertise of AT stakeholders. Results: This paper is a ‘call to action’, showcasing emerging AT networks as exemplars of a distributed, but integrated mechanism for addressing AT needs globally, and describing the Global Alliance of Assistive Technology Organisations (GAATO) as a vehicle to facilitate this global networking. Conclusion: Partners in this Global Alliance aim to advance the field of assistive technology by promoting shared research, policy advocacy, educating people and organisations within and outside the field, teaching, training and knowledge transfer by pulling together broad-based membership organisations

Inverse seesaw and dark matter in models with exotic lepton triplets

We show that models with exotic leptons transforming as E ~ (1,3,-1) under the standard model gauge symmetry are well suited for generating neutrino mass via a radiative inverse seesaw. This approach realizes natural neutrino masses and allows multiple new states to appear at the TeV scale. The exotic leptons are therefore good candidates for new physics that can be probed at the LHC. Furthermore, remnant low-energy symmetries ensure a stable dark matter candidate, providing a link between dark matter and the origins of neutrino mass.Comment: 6 pages, 3 figures (revtex4.1, two-columns

Z_3 Quantum Criticality in a spin-1/2 chain model

The stability of the magnetization $m=1/3$ plateau phase of the XXZ spin-1/2 Heisenberg chain with competing interactions is investigated upon switching on a staggered transverse magnetic field. Within a bosonization approach, it is shown that the low-energy properties of the model are described by an effective two-dimensional XY model in a three-fold symmetry-breaking field. A phase transition in the three-state Potts universality class is expected separating the $m=1/3$ plateau phase to a phase where the spins are polarized along the staggered magnetic field. The Z$_3$ critical properties of the transition are determined within the bosonization approach.Comment: 5 pages, revised versio

Renal function in patients with significant tricuspid regurgitation: pathophysiological mechanisms and prognostic implications

Background The pathophysiological mechanisms linking tricuspid regurgitation (TR) and chronic kidney disease (CKD) remain unknown. This study aimed to determine which pathophysiological mechanisms related to TR are independently associated with renal dysfunction and to evaluate the impact of renal impairment on long-term prognosis in patients with significant (>= moderate) secondary TR.Methods A total of 1234 individuals (72 [IQR 63-78] years, 50% male) with significant secondary TR were followed up for the occurrence of all-cause mortality and the presence of significant renal impairment (eGFR of <60 mL min(-1) 1.73 m(-2)) at the time of baseline echocardiography.Results Multivariable analysis demonstrated that severe right ventricular (RV) dysfunction (TAPSE < 14 mm) was independently associated with the presence of significant renal impairment (OR 1.49, 95% CI 1.11 to 1.99, P = 0.008). Worse renal function was associated with a significant reduction in survival at 1 and 5 years (85% vs. 87% vs. 68% vs. 58% at 1 year, and 72% vs. 64% vs. 39% vs. 19% at 5 years, for stage 1, 2, 3 and 4-5 CKD groups, respectively, P < 0.001). The presence of severe RV dysfunction was associated with reduced overall survival in stage 1-3 CKD groups, but not in stage 4-5 CKD groups.Conclusions Of the pathophysiological mechanisms identified by echocardiography that are associated with significant secondary TR, only severe RV dysfunction was independently associated with the presence of significant renal impairment. In addition, worse renal function according to CKD group was associated with a significant reduction in survival.Cardiolog

Brane fluctuation and the electroweak chiral Lagrangian

We use the external field method to study the electroweak chiral Lagrangian of the extra dimension model with brane fluctuation. Under the assumption that the contact terms between the matters of the standard model and KK excitations are heavily suppressed, we use the standard procedure to integrate out the quantum fields of KK excitations and the equation of motion to eliminate the classic fields of KK excitations. At one-loop level, we find that up to the order $O(p^4)$, due to the momentum conservation of the fifth dimension and the gauge symmetry of the zero modes, there is no constraint on the size of extra dimension. This result is consistent with the decoupling theorem. However, meaningful constraints can come from those operators in $O(p^6)$, which can contribute considerably to some anomalous vector couplings and can be accessible in the LC and LHC.Comment: Revised version, 20 pages in ReVTeX, to appear in PR

Association of right atrial strain and long-term outcome in severe secondary tricuspid regurgitation

Objective Severe secondary tricuspid regurgitation (STR) causes significant right atrial (RA) volume overload, resulting in structural and functional RA-remodelling. This study evaluated whether patients with severe STR and reduced RA function, as assessed by RA-reservoir-strain (RASr), show lower long-term prognosis. Methods Consecutive patients, from a single centre, with first diagnosis of severe STR and RASr measure available, were included. Extensive echocardiographic analysis comprised measures of cardiac chamber size and function, assessed also by two-dimensional speckletracking strain analysis. Primary outcome was all-cause mortality, analysed from inclusion until death or last follow-up. The association of RASr with the outcome was evaluated by Cox regression analysis and Akaike information criterion. Results A total of 586 patients with severe STR (age 68±13 years; 52% male) were included. Patients presented with mild right ventricular (RV) dilatation (enddiastolic area 13.8±6.5 cm2 /m2 ) and dysfunction (freewall strain 16.2±7.2%), and with moderate-to-severe RA dilatation (max area 15.0±5.3 cm2 /m2 ); the median value of RASr was 13%. In the overall population, 10-year overall survival was low (40%, 349 deaths), and was significantly lower in patients with lower RASr (defined by the median value): 36% (195 deaths) for RASr ≤13% compared with 45% (154 deaths) for RASr >13% (log-rank p=0.016). With a median follow-up of 6.6 years, RASr was independently associated with allcause mortality (HR per 5% RASr increase:0.928; 95% CI 0.864 to 0.996; p=0.038), providing additional value over relevant clinical and echocardiographic covariates (including RA size and RV function/size). Conclusions Patients with severe STR presented with significant RA remodelling, and lower RA function, as measured by RASr, was independently associated with all-cause mortality, potentially improving risk stratification in these patientsCardiolog

Left atrial dysfunction is an independent predictor of mortality in patients with cirrhosis treated by transjugular intrahepatic portosystemic shunt

The present study aimed to investigate (1) the association between left ventricular diastolic dysfunction (LVDD), graded according to the algorithm proposed by the Cirrhotic Cardiomyopathy Consortium, and long-term survival in patients with cirrhosis undergoing transjugular intrahepatic portosystemic shunt (TIPS) and (2) the additive prognostic value of left atrial (LA) function, as assessed by LA reservoir strain, using two-dimensional speckle-tracking echocardiography (2D-STE). A total of 129 TIPS candidates (mean +/- SD, 61 +/- 12 years; 61% men) underwent a comprehensive preprocedural echocardiography. LA dysfunction was defined by LA reservoir strain <= 35%, based on a previously suggested cut-off value. The outcome was all-cause mortality after TIPS. In the current cohort, 65 (50%) patients had normal diastolic function, 26 (20%) patients had grade 1 LVDD, 21 (16%) patients had grade 2 LVDD, and 17 (13%) patients had indeterminate diastolic function. Additionally, LA dysfunction (based on LA reservoir strain <= 35%) was noted in 67 (52%) patients. After a median follow-up of 36 months (range, 12-80), 65 (50%) patients died. All-cause mortality rates increased along worse grades of LVDD (log-rank p = 0.007) and with LA dysfunction (log-rank p = 0.001). On multivariable Cox regression analysis, Model for End-Stage Liver Disease score (hazard ratio [HR],1.06; p = 0.003), hemoglobin (HR, 0.74; p = 0.022), and LA strain, expressed as a continuous variable (HR, 0.96; p = 0.005) were independently associated with all-cause mortality. Notably, the addition of LA strain to the model provided incremental prognostic value over the established prognostic variables (delta chi(2) = 8.27, p = 0.004). Conclusion: LA dysfunction assessed with 2D-STE is independently associated with all-cause mortality in patients with cirrhosis treated by TIPS.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Experimental Probes of Localized Gravity: On and Off the Wall

The phenomenology of the Randall-Sundrum model of localized gravity is analyzed in detail for the two scenarios where the Standard Model (SM) gauge and matter fields are either confined to a TeV scale 3-brane or may propagate in a slice of five dimensional anti-deSitter space. In the latter instance, we derive the interactions of the graviton, gauge, and fermion Kaluza-Klein (KK) states. The resulting phenomenological signatures are shown to be highly dependent on the value of the 5-dimensional fermion mass and differ substantially from the case where the SM fields lie on the TeV-brane. In both scenarios, we examine the collider signatures for direct production of the graviton and gauge KK towers as well as their induced contributions to precision electroweak observables. These direct and indirect signatures are found to play a complementary role in the exploration of the model parameter space. In the case where the SM field content resides on the TeV-brane, we show that the LHC can probe the full parameter space and hence will either discover or exclude this model if the scale of electroweak physics on the 3-brane is less than 10 TeV. We also show that spontaneous electroweak symmetry breaking of the SM must take place on the TeV-brane.Comment: 62 pages, Latex, 22 figure

Right ventricular myocardial work: proof-of-concept for non-invasive assessment of right ventricular function

Aims Right ventricular myocardial work (RVMW) is a novel method for non-invasive assessment of right ventricular (RV) function utilizing RV pressure-strain loops. This study aimed to explore the relationship between RVMW and invasive indices of right heart catheterization (RHC) in a cohort of patients with heart failure with reduced left ventricular ejection fraction (HFrEF), and to compare values of RVMW with those of a group of patients without cardiovascular disease.Methods and results Non-invasive analysis of RVMW was performed in 22 HFrEF patients [median age 63 (59-67) years] who underwent echocardiography and invasive RHC within 48 h. Conventional RV functional measurements, RV global constructive work (RVGCW), RV global work index (RVGWI), RV global wasted work (RVGWVV), and RV global work efficiency (RVGWE) were analysed and compared with invasively measured stroke volume and stroke volume index. Non-invasive analysis of RVMW was also performed in 22 patients without cardiovascular disease to allow for comparison between groups. None of the conventional echocardiographic parameters of RV systolic function were significantly correlated with stroke volume or stroke volume index. In contrast, one of the novel indices derived non-invasively by pressure-strain Loops, RVGCW, demonstrated a moderate correlation with invasively measured stroke volume and stroke volume index (r = 0.63, P=0.002 and r = 0.59, P= 0.004, respectively). RVGWI, RVGCW, and RVGWE were significantly lower in patients with HFrEF compared to a healthy cohort, while values of RVGWVV were significantly higher.Conclusion RVGCW is a novel parameter that provides an integrative analysis of RV systolic function and correlates more closely with invasively measured stroke volume and stroke volume index than other standard echocardiographic parameters.Cardiolog