Modeling the dynamics of a dual input-single output closed-circuit hydraulic drive.

This work presents a scheme of a dual input-singleoutput closed-circuit hydraulic drive consisting of a pump and a hydraulic motor both variable displacement axial-piston type. It analyzes the dynamics of the hydraulic drive system through modeling and simulation. The model considers state-dependent non-linear losses and the temporal behaviors of the rotary actuators identified from the test data and these models are also considered in the simulation studies. The work also discusses the effects of nominal changes in the values of the decisive parameters on the drive's predicted performance to justify its practical range of application. Without dismantling the system components, comparing the test data with the simulation results verifies the system model for the drive's various working conditions. This aspect is essential for a priori analysis of a system and lends itself to be helpful for application engineers for the initial selection and development of a similar drive used in the mobile equipment.

Undiagnosed depression, persistent depressive symptoms and seeking mental health care: analysis of immigrant and non-immigrant participants of the Canadian Longitudinal Study of Aging.

AIMS: Early diagnosis and treatment of depression are associated with better prognosis. We used baseline data of the Canadian Longitudinal Study on Aging (2012-2015; ages 45-85 years) to examine differences in prevalence and predictors of undiagnosed depression (UD) between immigrants and non-immigrants at baseline and persistent and/or emerging depressive symptoms (DS) 18 months later. At this second time point, we also examined if a mental health care professional (MHCP) had been consulted. METHODS: We excluded individuals with any prior mood disorder and/or current anti-depressive medication use at baseline. UD was defined as the Center for Epidemiological Studies Depression 10 score ⩾10. DS at 18 months were defined as Kessler 10 score ⩾19. The associations of interest were examined in multivariate logistic regression models. RESULTS: Our study included 4382 immigrants and 18 620 non-immigrants. The mean age (standard deviation) in immigrants was 63 (10.3) years v. 65 (10.7) years in non-immigrants and 52.1% v. 57.1% were male. Among immigrants, 12.2% had UD at baseline of whom 34.2% had persistent DS 18 months later v. 10.6% and 31.4%, respectively, among non-immigrants. Female immigrants were more likely to have UD than female non-immigrants (odds ratio 1.50, 95% confidence interval 1.25-1.80) but no difference observed for men. The risk of persistent DS and consulting an MHCP at 18 months did not differ between immigrants and non-immigrants. CONCLUSIONS: Female immigrants may particularly benefit from depression screening. Seeking mental health care in the context of DS should be encouraged.

Achieving constant speed of a hydrostatic drive using controlled operation of the pump and enhancing its energy efficiency.

Novel ways of regulating the speed of a hydraulic drive through controlled operation of the pump either by loading/unloading the UPRV (unloading pressure relief valve) or by switching on/off of the prime mover driving the pump have been presented in this paper. The UPRV is used to operate the pump with a minimum load by diverting the pump delivery to the tank at low pressure. The energy efficiency of the said two methods adopted for controlling the hydro-motor speed is also compared. In this respect, the MATLAB®/Simulink model of the system is made and validated experimentally. The static and dynamic performances of the system are investigated using the validated model. The results show that the UPRV controlled system demonstrates better dynamic performance and controllability in terms of decreased fluctuations in hydro-motor speed for the small load torque demand. However, by comparing the energy efficiency of the hydraulic system for the two control strategies, it is found that with the increase in the machine torque demand, the intermittent operation of the pump unit may be more preferable with respect to the amount of energy saved for the complete duty cycle of the system.

Adult care providers' perspectives on the transition to adult care for emerging adults with Type 1 diabetes: a cross-sectional survey.

AIMS: To assess adult diabetes care providers' current transition practices, knowledge about transition care, and perceived barriers to implementation of best practices in transition care for emerging adults with Type 1 diabetes mellitus. METHODS: We administered a 38-item web-based survey to adult diabetes care providers identified through the Québec Endocrinologist Medical Association and Diabetes Québec. RESULTS: Fifty-three physicians responded (35%). Fewer than half of all respondents (46%) were familiar with the American Diabetes Association's transition care position statement. Approximately one-third of respondents reported a gap of >6 months between paediatric and adult diabetes care. Most (83%) believed communication with the paediatric team was adequate; however, only 56% reported receiving a medical summary and 2% a psychosocial summary from the paediatric provider. Respondents believed that the paediatric team should improve emerging adults' preparation for transition care by developing their self-management skills and improve teaching about the differences between paediatric and adult-oriented care. Only 31% had a system for identifying emerging adults lost to follow-up in adult care. Perceived barriers included difficulty accessing psychosocial services, emerging adults' lack of motivation, and inadequate transition preparation. Most (87%) were interested in having additional resources, including a self-care management tool and a registry to track those lost to follow-up. CONCLUSIONS: Our findings highlight the need to better engage adult care providers into transition care practices. Despite adult physicians' interest in transition care, implementation of transition care recommendations and resources in clinical care remains limited. Enhanced efforts are needed to improve access to mental health services within the adult healthcare setting.

Carbon nano tubes functionalized with novel functional group- amido-amine for sorption of actinides.

The manuscript presents the results on the sorption of U(VI), Am(III) & Eu(III) from pH medium by a novel amido-amine functionalized multiwalled carbon nanotube (MWCNT). The novel functional group was introduced in the MWCNT by two step processes and characterized by various instrumental techniques like Scanning Electron Microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS). The sorption process was found to be highly dependent on the pH of the solution with maximum sorption for both 233U, 241Am & 152+154Eu at pH 7.0. Kinetics of sorption was found to be fast with equilibrium reached in ∼15min and the sorption was found to be following pseudo 2nd order kinetics for the radionuclides. The sorption for both 233U and 152+154Eu followed Langmuir sorption model with maximum sorption capacity of 20.66mg/g and 16.1mg/g respectively. This has been explained by DFT calculations which shows that more negative solvation energy of U(VI) compared to Am(III) and Eu(III) and stronger U-MWCNT-AA complex is responsible for higher sorption capacity of U(VI) compared to Am(III) and Eu(III).The synthesized amido-amine functionalized MWCNT is a very promising candidate for removal of actinides and lanthanides from waste water solution with high efficiency.

Diabetes risk in women with gestational diabetes mellitus and a history of polycystic ovary syndrome: a retrospective cohort study.

AIMS: To investigate whether polycystic ovary syndrome further increases postpartum diabetes risk in women with gestational diabetes mellitus and to explore relationships between polycystic ovary syndrome and incident diabetes in women who do not develop gestational diabetes. METHODS: This retrospective cohort study (Quebec Physician Services Claims; Hospitalization Discharge Databases; Birth and Death registries) included 34 686 women with gestational diabetes during pregnancy (live birth), matched 1:1 to women without gestational diabetes by age group, year of delivery and health region. Diagnostic codes were used to define polycystic ovary syndrome and incident diabetes. Cox regression models were used to examine associations between polycystic ovary syndrome and incident diabetes. RESULTS: Polycystic ovary syndrome was present in 1.5% of women with gestational diabetes and 1.2% of women without gestational diabetes. There were more younger mothers and mothers who were not of white European ancestry among those with polycystic ovary syndrome. Those with polycystic ovary syndrome more often had a comorbidity and a lower proportion had a previous pregnancy. Polycystic ovary syndrome was associated with incident diabetes (hazard ratio 1.52; 95% CI 1.27, 1.82) among women with gestational diabetes. No conclusive associations between polycystic ovary syndrome and diabetes were identified (hazard ratio 0.94; 95% CI 0.39, 2.27) in women without gestational diabetes. CONCLUSION: In women with gestational diabetes, polycystic ovary syndrome confers additional risk for incident diabetes postpartum. In women without gestational diabetes, an association between PCOS and incident diabetes was not observed. Given the already elevated risk of diabetes in women with a history of gestational diabetes, a history of both polycystic ovary syndrome and gestational diabetes signal a critical need for diabetes surveillance and prevention.

An atomic magnetometer with autonomous frequency stabilization and large dynamic range.

The operation of a highly sensitive atomic magnetometer using elliptically polarized resonant light is demonstrated. It is based on measurement of zero magnetic field resonance in degenerate two level systems using polarimetric detection. The transmitted light through the polarimeter is used for laser frequency stabilization, whereas reflected light is used for magnetic field measurement. Thus, the experimental geometry allows autonomous frequency stabilization of the laser frequency leading to compact operation of the overall device and has a preliminary sensitivity of <10 pT/Hz(1/2) @ 1 Hz. Additionally, the dynamic range of the device is improved by feedback controlling the bias magnetic field without compromising on its sensitivity.

Phase-sharing using a Mach-Zehnder interferometer.

A phase-sharing scheme using the Mach-Zehnder interferometric setup is demonstrated. Two coherent light fields of the same wavelength which have orthogonal polarizations are used as sources at the two ends of a Mach-Zehnder interferometer. They are made to interfere independently at the opposing ends of the interferometer so that the phase estimated by two observers at the two opposing ends of the interferometer is nearly identical. The scheme could in principle be used by two observers to simultaneously monitor and study a phase object inserted in one of the arms of the interferometer. A pseudorandom phase plate which mimics atmospheric turbulence is inserted in one of the arms of the interferometer to demonstrate that such a phase-sharing scheme could be converted to a secret-key sharing scheme. Shared secret-key generation is demonstrated through evaluation of the phase correlates of the shared phase samples available at their respective ends. The shared random phases could also be used in a more direct manner by the respective observers for random phase encryption of images.

Note: design and development of improved indirectly heated cathode based strip electron gun.

An improved design of indirectly heated solid cathode based electron gun (200 kW, 45 kV, 270° bent strip type electron gun) has been presented. The solid cathode is made of thoriated tungsten, which acts as an improved source of electron at lower temperature. So, high power operation is possible without affecting structural integrity of the electron gun. The design issues are addressed based on the uniformity of temperature on the solid cathode and the single long filament based design. The design approach consists of simulation followed by extensive experimentation. In the design, the effort has been put to tailor the non-uniformity of the heat flux from the filament to the solid cathode to obtain better uniformity of temperature on the solid cathode. Trial beam experiments have been carried out and it is seen that the modified design achieves one to one correspondence of the solid cathode length and the electron beam length.

The association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes.

AIMS: We examined the association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes in a multi-ethnic and socio-economically diverse patient group. METHODS: Medical charts at a Toronto gestational diabetes clinic were reviewed for women with a recorded pregnancy between 1 March 2006 and 26 April 2011. One-hour 50-g glucose challenge test values and postal code data were abstracted. Postal codes were merged with 2006 Canadian census data to compute neighbourhood-level ethnic concentration (% recent immigrants, % visible minorities) and material deprivation (% low education, % low income, single-parent households). We compared women in the highest neighbourhood quintiles for both ethnic concentration and material deprivation with all other women to explore an association between marginalization and diagnostic glucose levels. Multivariate regression models of glucose challenge test values and insulin prescription were adjusted for age, prior gestational diabetes, parity and diabetes family history. RESULTS: Among 531 patients with complete glucose challenge test data (mean 11.94 mmol/l, sd 1.83), those in the most marginalized neighbourhoods had 0.43 mmol/l higher glucose challenge test values (95% CI 0.08-0.78) compared with the rest of the study population. Other factors associated with higher glucose challenge test values were prior gestational diabetes (0.59 mmol/l increment, 95% CI 0.19-0.99) and diabetes family history (0.32 mmol/l increment, 95% CI -0.01 to 0.66). Each additional 1 mmol/l glucose challenge test result was associated with an increased likelihood of being prescribed insulin (odds ratio 1.33, 95% CI 1.17-1.51). CONCLUSIONS: Women living in the most materially deprived and ethnically concentrated neighbourhoods have higher glucose levels at diagnosis of gestational diabetes. They may need close monitoring for timely initiation of insulin.

Towards sensitive label-free immunosensing by means of turn-around point long period fiber gratings.

Long period fiber gratings have been effectively used in the field of biochemical sensing since a few years. Compared to other well-known label-free optical approaches, long period gratings (LPGs) take advantage of the typical peculiarity of optical fibers. Coupling the propagating core mode with a high-order cladding mode near its turn-around point (TAP) was the strategy adopted to achieve good performances without additional coatings, except for the sensing and selective biolayer deposited on the fiber. Both the modeling and manufacturing of TAP LPGs were discussed. After the functionalization of the fiber surface with the deposition of a Eudragit L100 copolymer layer followed by immunoglobulin G (IgG) covalent immobilization, an IgG/anti-IgG bioassay was implemented along the grating region and the kinetics of antibody/antigen interaction was analyzed. A quantitative comparison between a TAP LPG and a non-TAP LPG was carried out to highlight the improvement of the proposed immunosensor. The real effectiveness and feasibility of an LPG-based biosensor were demonstrated by using a complex matrix consisting of human serum, which also confirmed the specificity of the assay, and a limit of detection of 70 µg L(-1) (460 pM) was achieved.

Differential association of insulin resistance with cognitive and somatic symptoms of depression.

AIM: To examine the associations of depressive symptoms with insulin resistance, evaluating somatic and cognitive depressive symptoms separately. METHODS: A total of 328 individuals (mean age 60 years) referred for exercise stress testing, taking part in the Mechanisms and Outcomes of Silent Myocardial Ischemia study, completed the Beck Depression Inventory II. A fasting venous blood sample was collected for assessments of insulin and glucose level; the HOMA-IR (homeostatic model assessment of insulin resistance) was calculated. In principal component analysis, Beck Depression Inventory II items were forced to load onto two components (somatic and cognitive depressive symptoms). Adjusting for age, sex, BMI, medication use, smoking, physical activity, diabetes and cardiovascular disease, general linear model analyses were conducted to examine the associations between the components and log HOMA-IR . RESULTS: Principal component analysis showed that nine items loaded onto a cognitive depressive symptoms component and 10 items loaded onto a somatic depressive symptoms component. When examined separately, both components were significantly associated with log HOMA-IR however, when including both components simultaneously in the model, only somatic depressive symptoms remained significantly associated with log HOMA-IR. Back-transformed, a one-unit change in somatic depressive symptoms was associated with a 1.07 (95% CI 1.002, 1.14) change in HOMA-IR and a one-unit change in cognitive depressive symptoms was associated with a 1.03 (95% CI 0.97, 1.14) change in HOMA-IR. CONCLUSION: Somatic depressive symptoms seem to be more strongly associated with insulin resistance than do cognitive depressive symptoms. Monitoring somatic depressive symptoms may be more appropriate than monitoring cognitive depressive symptoms among depressed individuals with high insulin resistance.

Abdominal adiposity and daily step counts as determinants of glycemic control in a cohort of patients with type 2 diabetes mellitus.

OBJECTIVE: Favorable effects of walking levels on glycemic control have been hypothesized to be mediated through reductions in abdominal adiposity, but this has not been well studied. We addressed this issue in patients treated for type 2 diabetes. DESIGN: Cross-sectional analysis. SUBJECTS: A total of 201 subjects with type 2 diabetes underwent assessments of pedometer-measured daily step counts, blood pressure, A1C and anthropometric measures (2006-2010). Associations of anthropometric indicators of abdominal adiposity (that is, waist circumference; waist-to-hip ratio (WHR)) with A1C were evaluated through linear regression models adjusting for age, ethnicity, sex and the use of insulin and oral hypoglycemic agents. Models including waist circumference were additionally adjusted for body mass index (BMI). A similar approach was used to examine A1C and daily step associations. RESULTS: Among the 190 subjects (mean age 60 years; mean BMI 30.4 kg m(-2)), mean values (s.d.) for waist circumference and WHR were respectively, 99.1 cm (13.3) and 0.88 (0.07) in women, and 104.5 cm (13.1) and 0.97 (0.06) in men. Mean A1C and daily step count were respectively, 7.6% (1.4) and 5 338 steps per day (2609), and were similar for both sexes.There was a 0.51% (95% confidence interval (CI): 0.10, 0.93) A1C increment per s.d. increase in waist circumference and a 0.32% (95% CI: 0.08, 0.56) A1C increment per s.d. increase in WHR in fully adjusted models. Each s.d. increase in daily step count was associated with clinically significant reductions in waist circumference and BMI. Each s.d. increase in daily steps was associated with a 0.21% (95% CI: 0.02, 0.41) A1C decrement that declined to 0.16% (95% CI: -0.35, 0.04) with further adjustment for anthropometric indicators of abdominal adiposity. CONCLUSION: Higher daily steps may be associated with lower A1C values both directly and via changes in abdominal adiposity.

Mortality in diabetes compared with previous cardiovascular disease: a gender-specific meta-analysis.

AIMS: Diabetes has been described as a cardiovascular disease (CVD) risk equivalent. There is evidence, however, that its impact may differ between women and men. For this reason, our study aimed to obtain gender-specific hazard ratios (HRs) comparing diabetes and CVD patients in terms of all-cause, CVD and coronary heart disease (CHD) mortality. METHODS: Individuals with diabetes (without CVD) and those with CVD (without diabetes) were examined through a systematic review of articles that provided gender-specific HRs for mortality. Searches included Medline, Embase and the Cochrane Library database (from January 1998 to December 2009) and exploded MeSH headings [cardiovascular diseases, risk, epidemiologic studies, case-control studies, cohort studies, mortality, outcome assessment (health care), sex factors, survival analysis and diabetes mellitus, type 2]. Two observers selected and reviewed the studies and hierarchical Bayesian random-effects models were used to combine HRs, thereby accommodating any between-study differences through inclusion of a between-study variance in HRs. RESULTS: Out of 5425 studies, nine were relevant (0.17%). CVD and CHD mortality in men was lower for diabetes alone (CVD mortality HR: 0.82, 95% CrI: 0.69-0.98; CHD mortality HR: 0.73, 95% CrI: 0.65-0.83). In contrast, rates appeared to be higher in women with diabetes alone (CVD mortality HR: 1.29, 95% CrI: 0.79-2.26; CHD mortality HR: 1.28, 95% CrI: 0.75-2.22), although wide credible intervals precluded any definitive conclusions. All-cause mortality in men was similar for diabetes and previous CVD (HR: 1.02, 95% CrI: 0.93-1.12) whereas, among women, it was at least as high and possibly higher for diabetes alone (HR: 1.25, 95% CrI: 0.89-1.76). CONCLUSION: Compared with previous CVD, diabetes alone leads to lower CVD and CHD mortality risk in men, and similar all-cause mortality. In contrast, although further studies are needed, it is possible that diabetes leads to higher CVD, CHD and all-cause mortality in women.

Vitamin supplementation and blood pressure in Type 2 diabetes.

AIMS: Vitamin D levels are inversely related to blood pressure. Given that low sun exposure can create a greater reliance on dietary sources of vitamin D, we aimed to determine whether dietary vitamin D and blood pressure associations differ between periods of low and high sun exposure. METHODS: Dietary intake, vitamin supplementation, blood pressure, and anthropometric parameters were assessed each season for 1 year (174 adults with Type 2 diabetes). Separate linear regression models were constructed for high and low sun exposure periods to examine associations of systolic blood pressure with dietary vitamin D intake and vitamin supplement use (adjusted for age, gender, BMI, ethnicity, smoking, alcohol, physical activity, antihypertensive medication and nutrient intake). Robustness of findings was confirmed with within-subject repeated measures analysis, including an interaction term for sun exposure period. RESULTS: Vitamin D intake from food sources was low year-round and no conclusive association with blood pressure was identified during either period. Systolic blood pressure was 5.1 mmHg lower during the low sun exposure period (95% CI 0.5-9.7) in daily supplement users compared with non-users. The interaction term between supplement use and sun exposure period was significant (low sun exposure* no supplement, P = 0.02). Systolic blood pressure was relatively stable in users (low and high sun exposure periods, respectively, mean ± SE: 135.2 ± 2.6 mmHg and 134.2 ± 2.5 mmHg), but not in non-users (140.2 ± 2.7 mmHg and 130.5 ± 2.5 mmHg). CONCLUSIONS: Vitamin supplementation may stabilize systolic blood pressure in adults with Type 2 diabetes across seasons.

A study of regenerated gratings produced in germanosilicate fibers by high temperature annealing.

In light of recent proposals linking structural change and stresses within regenerated gratings, the details of regeneration of a seed Type-I Bragg grating written in H2 loaded germanosilicate fiber annealed at high temperatures (~900°C) are systematically explored. In particular, the influence of the strength of the grating, the effect of GeO2 doping concentration and the annealing conditions on regeneration are studied. We show that the role of dopants such as Ge and F contribute nothing to the regeneration, consistent with previous results. Rather, they may potentially be detrimental. Strongest regenerated gratings with R ~35% from a 5mm seed grating could be obtained in fibres with the lowest GeO2 concentrations such as standard telecommunications-compatible grade fibre.

Type 2 diabetes in Canada: concentration of risk among most disadvantaged men but inverse social gradient across groups in women.

AIMS: To assess sex-specific associations of educational and income levels with Type 2 diabetes mellitus. METHODS: Logistic regression analyses (Canadian Community Health Survey, cross-sectional) adjusted for ethnicity, immigration, urban/rural, overweight/obesity, physical inactivity, smoking, chronic conditions and regular physician. RESULTS: Compared to women with some post-secondary education, Type 2 diabetes was more likely in both high school graduates without post-secondary education [odds ratio (OR) 1.27, 95% confidence interval (CI) 1.07-1.51] and high school non-completers (OR 1.73, 95% CI 1.47-2.04); among men, definitive conclusions in high school graduates without post-secondary education could not be drawn (OR 0.93, 95% CI 0.78-1.12), but Type 2 diabetes was more likely in high school non-completers (OR 1.26, 95% CI 1.08-1.48). Compared to women with the highest income, Type 2 diabetes was three times more likely in the lowest income group (OR 2.90, 95% CI 2.25-3.73), 2.53 times more likely in the low middle income group (OR 2.53, 95% CI 1.98-3.24) and 55% more likely in the high middle income group (OR 1.55, 95% CI 1.20-2.01). Among men, Type 2 diabetes was approximately 40% more likely in both the lowest (OR 1.41, 95% CI 1.10-1.80) and low middle income groups (OR 1.39, 95% CI 1.12-1.71); definitive conclusions in the high middle income group could not be drawn (OR 1.05, 95% CI 0.87-1.28). CONCLUSIONS: In women, Type 2 diabetes increased monotonically with lower educational and income levels; in men, Type 2 diabetes was concentrated in the least educated and least affluent. Our findings support the need for policies and practices that lower diabetes risk among the most disadvantaged women and men and moderately disadvantaged women.

Optimization of parameters by Taguchi method for controlling purity of carbon nanotubes in chemical vapour deposition technique.

The process parameters (viz. temperature of synthesis, type of catalyst, concentration of catalyst and type of catalyst-support material) for controlling purity of carbon nanotubes synthesized by catalytic chemical vapour deposition of acetylene have been optimized by analyzing the experimental results using Taguchi method. It has been observed that the catalyst-support material has the maximum (59.4%) and the temperature of synthesis has the minimum effect (2.1%) on purity of the nanotubes. At optimum condition (15% ferrocene supported on carbon black at the synthesis temperature of 700 degrees C) the purity of nanotubes was found out to be 96.2% with yield of 1900%. Thermogravimetry has been used to assess purity of nanotubes. These nantubes have been further characterized by scanning electron microscopy, transmission electron microscopy and Raman Spectroscopy. Small angle neutron scattering has been used to find out their average inner and outer diameter using an appropriate model. The nanotubes are well crystallized but with wide range of diameter varying between 20-150 nm.

Understanding physical activity facilitators and barriers during and following a supervised exercise programme in Type 2 diabetes: a qualitative study.

AIMS: To assess barriers and facilitators of participation in a supervised exercise programme, and adherence to exercise after programme completion. METHODS: Focus group discussions addressed factors which could facilitate attendance, current engagement in exercise, reasons for continuing or discontinuing regular exercise and ways to integrate exercise into daily life. Three focus groups, with a total of 16 participants, were led by a trained moderator; audiotapes were transcribed verbatim; transcripts were coded and themes were identified. Themes that recurred across all three focus groups were considered to have achieved saturation. RESULTS: Motivation was the most critical factor in exercising both during and following the programme. Participants appreciated the monitoring, encouragement and accountability provided by programme staff. They voiced a need for better transition to post-programme realities of less support and supervision. Co-morbid conditions were apt to derail them from a regular exercise routine. They viewed the optimal programme as having even greater scheduling flexibility and being closer to them geographically. Post-programme, walking emerged as the most frequent form of physical activity. CONCLUSIONS: Adults with Type 2 diabetes require long-term monitoring and support for physical activity and exercise.