Distributed leader following of an active leader for linear heterogeneous multi-agent systems

This paper considers a leader-following problem for a group of heterogeneous linear time invariant (LTI) followers that are interacting over a directed acyclic graph. Only a subset of the followers has access to the state of the leader in specific sampling times. The dynamics of the leader that generates its sampled states is unknown to the followers. For interaction topologies in which the leader is a global sink in the graph, we propose a distributed algorithm that allows the followers to arrive at the sampled state of the leader by the time the next sample arrives. Our algorithm is a practical solution for a leader-following problem when there is no information available about the state of the leader except its instantaneous value at the sampling times. Our algorithm also allows the followers to track the sampled state of the leader with a locally chosen offset that can be time-varying. When the followers are mobile agents whose state or part of their state is their position vector, the offset mechanism can be used to enable the followers to form a transnational invariant formation about the sampled state of the leader. We prove that the control input of the followers to take them from one sampled state to the next one is minimum energy. We also show in case of the homogeneous followers, after the first sampling epoch the states and inputs of all the followers are synchronized with each other. Numerical examples demonstrate our results

Teaching abstract concepts in contemporary nursing through spirituality

Author name used in this publication: Loretta Yuet Foon Chung2003-2004 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Patient Empowerment Programme in primary care reduced all-cause mortality and cardiovascular diseases in patients with type 2 diabetes mellitus: a population-based propensity-matched cohort study

Aims: To assess whether a structured diabetes education programme, Patient Empowerment Programme (PEP), was associated with a lower risk of first cardiovascular disease (CVD) event and all-cause mortality in a population-based cohort of type 2 diabetes mellitus (T2DM) patients in primary care. Materials and Methods: A Chinese cohort of 27,278 T2DM patients without prior occurrence of CVD events on or before baseline study recruitment date was linked to the Hong Kong administrative database from 2008 to 2013. PEP was provided to T2DM patients treated at primary care outpatient clinics through community trained professional educators. Non-PEP participants were matched one-to-one with the PEP participants using propensity score method with respect to their baseline covariates. Cox proportional hazard regressions were performed to estimate the associations of PEP with the occurrence of first CVD event, coronary heart disease, stroke, heart failure and death from any cause, controlling for baseline characteristics. Results: During a median of 21.5 months follow-up, 795 (352 PEP participants and 443 non-PEP participants) patients suffered a first CVD event. After adjusting for confounding variables, PEP participants had a lower incidence of all-cause mortality (hazard ratio: 0.564; 95%CI:0.445-0.715; P < 0.001), first CVD (hazard ratio: 0.807; 95%CI:0.696-0.935; P = 0.004) and stroke (hazard ratio: 0.702; 95%CI:0.569-0.867; P = 0.001) events than those without PEP. Conclusions: Enrolment in PEP was associated with reduced all-cause mortality and first CVD events among T2DM patients. The CVD benefit of PEP might be attributable to improving metabolic control through empowerment of self-care and enhancement of quality of diabetes care in primary care.postprin

Effects of Patient Empowerment Programme (PEP) on Clinical Outcomes and Health Service Utilization in Type 2 Diabetes Mellitus in Primary Care: An Observational Matched Cohort Study

Background: To evaluate the effects of a large population-based patient empowerment programme (PEP) on clinical outcomes and health service utilization rates in type 2 diabetes mellitus (T2DM) patients in the primary care setting. Research Design and Subjects: A stratified random sample of 1,141 patients with T2DM enrolled to PEP between March and September 2010 were selected from general outpatient clinics (GOPC) across Hong Kong and compared with an equal number of T2DM patients who had not participated in the PEP (non-PEP group) matched by age, sex and HbA1C level group. Measures: Clinical outcomes of HbA1c, SBP, DBP and LDL-C levels, and health service utilization rates including numbers of visits to GOPC, specialist outpatient clinics (SOPC), emergency department (ED) and inpatient admissions, were measured at baseline and at 12-month post-recruitment. The effects of PEP on clinical outcomes and health service utilization rates were assessed by the difference-in-difference estimation, using the generalized estimating equation models. Results: Compared with non-PEP group, PEP group achieved additional improvements in clinical outcomes over the 12-month period. A significantly greater percentage of patients in the PEP group attained HbA1C≤7% or LDL-C≤2.6 mmol/L at 12-month follow-up compared with the non-PEP group. PEP group had a mean 0.813 fewer GOPC visits in comparison with the non-PEP group. Conclusions: PEP was effective in improving the clinical outcomes and reduced the general outpatient clinic utilization rate over a 12-month period. Empowering T2DM patients on self-management of their disease can enhance the quality of diabetes care in primary care.published_or_final_versio

Community nursing services for postdischarge chronically ill patients

Author name used in this publication: Susan K. Y. ChowAuthor name used in this publication: Frances K. Y. WongAuthor name used in this publication: Loretta Y. F. Chung2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Enhanced mitochondrial superoxide scavenging does not Improve muscle insulin action in the high fat-fed mouse

Improving mitochondrial oxidant scavenging may be a viable strategy for the treatment of insulin resistance and diabetes. Mice overexpressing the mitochondrial matrix isoform of superoxide dismutase (sod2(tg) mice) and/or transgenically expressing catalase within the mitochondrial matrix (mcat(tg) mice) have increased scavenging of O2(˙-) and H2O2, respectively. Furthermore, muscle insulin action is partially preserved in high fat (HF)-fed mcat(tg) mice. The goal of the current study was to test the hypothesis that increased O2(˙-) scavenging alone or in combination with increased H2O2 scavenging (mtAO mice) enhances in vivo muscle insulin action in the HF-fed mouse. Insulin action was examined in conscious, unrestrained and unstressed wild type (WT), sod2(tg), mcat(tg) and mtAO mice using hyperinsulinemic-euglycemic clamps (insulin clamps) combined with radioactive glucose tracers following sixteen weeks of normal chow or HF (60% calories from fat) feeding. Glucose infusion rates, whole body glucose disappearance, and muscle glucose uptake during the insulin clamp were similar in chow- and HF-fed WT and sod2(tg) mice. Consistent with our previous work, HF-fed mcat(tg) mice had improved muscle insulin action, however, an additive effect was not seen in mtAO mice. Insulin-stimulated Akt phosphorylation in muscle from clamped mice was consistent with glucose flux measurements. These results demonstrate that increased O2(˙-) scavenging does not improve muscle insulin action in the HF-fed mouse alone or when coupled to increased H2O2 scavenging

The impact of young age on cancer-specific and non-cancer-related survival after surgery for colorectal cancer: 10-year follow-up

&lt;b&gt;Background&lt;/b&gt;: It has been reported that although young patients present with more advanced disease, when adjusted for stage, cancer-specific survival is not different after surgery for colorectal cancer. However, few studies have examined non-cancer survival in young patients and 10-year survival has rarely been reported. Moreover, the largest study included patients of old age as a comparator. The aim of this study was to compare cancer-specific and non-cancer-related survival at 10 years in a young age cohort and a middle age cohort in patients undergoing surgery for colorectal cancer. &lt;b&gt;Methods&lt;/b&gt;: Two thousand and seventy seven patients who underwent surgery for colorectal cancer between 1991 and 1994 in 11 hospitals in Scotland were included in the study. Ten-year cancer-specific and non-cancer-related survival and the hazard ratios (HR) were calculated according to age groups (&#60;45/45–54/55–64/65–74 years). &lt;b&gt;Results&lt;/b&gt;: On follow-up, 1066 patients died of their cancer and 369 died of non-cancer-related causes. At 10 years, overall survival was 32&#37;, cancer-specific was 45&#37;, and non-cancer-related survival was 72&#37;. On multivariate analysis of all factors, sex (HR 0.77, 95&#37; CI 0.68–0.88, P&#60;0.001), mode of presentation (HR 1.64, 95&#37; CI 1.44–1.87, P&#60;0.01), Dukes' stage (HR 2.69, 95&#37; CI 2.49–2.90, P&#60;0.001), and specialisation (HR 1.24, 95&#37; CI 1.04–1.44, P&#60;0.01) were independently associated with cancer-specific survival. On multivariate analysis of all factors, age (HR 2.46, 2.04–2.97, P&#60;0.001), sex (HR 0.56, 0.45–0.70, P&#60;0.001), and deprivation (HR 1.16, 1.10–1.24, P&#60;0.001) were independently associated with non-cancer-related survival. &lt;b&gt;Conclusion&lt;/b&gt;: The results of this study confirm that young age does not have a negative impact on cancer-specific survival. Moreover, they show that, with 10-year follow-up, young age does not have a negative impact on non-cancer-related survival

A Geometric Approach to CP Violation: Applications to the MCPMFV SUSY Model

We analyze the constraints imposed by experimental upper limits on electric dipole moments (EDMs) within the Maximally CP- and Minimally Flavour-Violating (MCPMFV) version of the MSSM. Since the MCPMFV scenario has 6 non-standard CP-violating phases, in addition to the CP-odd QCD vacuum phase \theta_QCD, cancellations may occur among the CP-violating contributions to the three measured EDMs, those of the Thallium, neutron and Mercury, leaving open the possibility of relatively large values of the other CP-violating observables. We develop a novel geometric method that uses the small-phase approximation as a starting point, takes the existing EDM constraints into account, and enables us to find maximal values of other CP-violating observables, such as the EDMs of the Deuteron and muon, the CP-violating asymmetry in b --> s \gamma decay, and the B_s mixing phase. We apply this geometric method to provide upper limits on these observables within specific benchmark supersymmetric scenarios, including extensions that allow for a non-zero \theta_QCD.Comment: 34 pages, 16 eps figures, to appear in JHE

Management of Sigmoid Volvulus Avoiding Sigmoid Resection

Acute sigmoid volvulus is typically caused by an excessively mobile and redundant segment of colon with a stretched mesenteric pedicle. When this segment twists on its pedicle, the result can be obstruction, ischemia and perforation. A healthy, 18-year-old Caucasian woman presented to the emergency department complaining of cramping abdominal pain, distention, constipation and obstipation for the last 72 h, accompanied by nausea, vomiting and abdominal tenderness. The patient had tympanitic percussion tones and no bowel sounds. She was diagnosed with acute sigmoid volvulus. Although urgent resective surgery seems to be the appropriate treatment for those who present with acute abdominal pain, intestinal perforation or ischemic necrosis of the intestinal mucosa, the first therapeutic choice for clinically stable patients in good general condition is considered, by many institutions, to be endoscopic decompression. Controversy exists on the decision of the time, the type of definitive treatment, the strategy and the most appropriate surgical technique, especially for teenagers for whom sigmoid resection can be avoided