In the last few decades, the frequency and intensity of water-related disasters, also called clim... more In the last few decades, the frequency and intensity of water-related disasters, also called climate-related disasters, e.g. floods, storms, heat waves and droughts, has gone up considerably at both global and regional scales, causing significant damage to many societies and ecosystems. Understanding the behavior and frequency of these disasters is extremely important, not only for reducing their damages but also for the management of water resources. These disasters can often be characterized by multiple dependent variables and therefore require a flexible multivariate approach for studying such phenomena. In this study, we focus on copulas, which are multivariate functions that describe the dependence structure between stochastic variables, independently of their marginal behaviors. The study aimed at different potential applications of copulas in hydrology, such as a multivariate frequency analysis and a copula-based approach for assessing a rainfall model. And further, a stochas...
Background Treatment of HIV with antiretroviral therapy (ART) can improve the health of people li... more Background Treatment of HIV with antiretroviral therapy (ART) can improve the health of people living with HIV (PLHIV), stop onward transmission of HIV and effectively prevent the spread of the virus. In 2016, we conducted a systematic review to assess the feasibility of treatment monitoring for PLHIV on ART in low and middle-income countries (LMICs), in line with the 90-90-90 treatment target. By 2020, global estimates suggest the 90-90-90 target remains unattainable in many LMICs. This study aims to review the progress and identify needs for public health interventions to improve viral load monitoring and viral suppression for PLHIV in LMICs. Methods A literature search was conducted using an update of the initial search strategy developed for the 2016 review with key search terms relevant to HIV treatment and care, decentralization and viral load monitoring. Electronic databases (Medline and PubMed) were searched to identify relevant literature published in English between Dec 20...
In this paper, we present our methods for unrealiable information identification task at ReINTEL ... more In this paper, we present our methods for unrealiable information identification task at ReINTEL Challenge 2020. The task is to classify a piece of information into reliable or unreliable category. We propose a novel multimodal ensemble model which combines two multimodal models to solve the task. In each multimodal model, we combined feature representations acquired from three different data types: texts, images, and metadata. Multimodal features are derived from three neural networks and fused for classification. Experimental results showed that our proposed ensemble model improved against single models in term of AUC score. We obtained 0.9445 AUC score on the private test of the challenge.
The advent of telerobotic systems has revolutionized various aspects of the industry and human li... more The advent of telerobotic systems has revolutionized various aspects of the industry and human life. This technology is designed to augment human sensorimotor capabilities to extend them beyond natural competence. Classic examples are space and underwater applications when distance and access are the two major physical barriers to be combated with this technology. In modern examples, telerobotic systems have been used in several clinical applications, including teleoperated surgery and telerehabilitation. In this regard, there has been a significant amount of research and development due to the major benefits in terms of medical outcomes. Recently telerobotic systems are combined with advanced artificial intelligence modules to better share the agency with the operator and open new doors of medical automation. In this review paper, we have provided a comprehensive analysis of the literature considering various topologies of telerobotic systems in the medical domain while shedding li...
In this paper, we evaluate end-to-end outage probability of a multi-hop decode-and-forward relayi... more In this paper, we evaluate end-to-end outage probability of a multi-hop decode-and-forward relaying protocol in underlay cognitive radio network. In the proposed protocol, named COOP, secondary nodes including source and relays have to harvest radio-frequency energy from multiple secondary power beacons, and adjust their transmit power, follows a pre-determined interference threshold given by multiple primary users. To enhance the outage performance for the secondary network under an joint constraint of the interference threshold, Rayleigh fading channel and hardware noises caused by imperfect transceiver hardware, the secondary relays on the source-destination path cooperate to forward the source data to the destination. Particularly, they attempt to receive the source data from their previous nodes, and forward it to the secondary destination if requested. Moreover, whenever the destination cannot receive the source data successfully, a successful relay that has the shortest dista...
Parkinson's disease (PD) is a neurodegenerative movement disorder associated with gait and ba... more Parkinson's disease (PD) is a neurodegenerative movement disorder associated with gait and balance problems and a substantially increased risk of falling. Falls occur often during complex movements, such as turns. Both fear of falling (FOF) and previous falls are relevant risk factors for future falls. Based on recent studies indicating that lab-based and home assessment of similar movements show different results, we hypothesized that FOF and a positive fall history would influence the quantitative turning parameters differently in the laboratory and home. Fifty-five PD patients (43 underwent a standardized lab assessment; 40 were assessed over a mean of 12 days at home with approximately 10,000 turns per participant; and 28 contributed to both assessments) were classified regarding FOF and previous falls as "vigorous" (no FOF, negative fall history), "anxious" (FOF, negative fall history), "stoic" (no FOF, positive fall history) and "aware&qu...
Undernutrition remains a significant cause of childhood illness, poor growth, development, and de... more Undernutrition remains a significant cause of childhood illness, poor growth, development, and death in Papua New Guinea (PNG). Studies on child nutritional outcomes in PNG vary by design, measurement protocols and quality. We conducted a systematic review to assess the evidence for the prevalence of child undernutrition across different study populations, geographical locations and time periods. Six electronic databases and additional grey literature were searched for articles describing the nutritional status by wasting, stunting and underweight, of PNG children under five years of age, published between 1990 and April 2015. Prevalence data using different scales of measurement and reference populations were standardized according to WHO protocols. The search yielded 566 articles, of which, 31 studies met the inclusion criteria. The prevalence of child undernutrition varied from 1% to 76% for wasting (median 11%), 5% to 92% for stunting (median 51%), and 14% to 59% for underweight...
The continuing spread of the newly emerged H7N9 virus among poultry in China, as well as the poss... more The continuing spread of the newly emerged H7N9 virus among poultry in China, as well as the possibility of human-to-human transmission, has attracted numerous efforts to develop an effective vaccine against H7N9. The use of nanoparticles in vaccinology is inspired by the fact that most pathogens have a dimension within the nano-size range and therefore can be processed efficiently by the immune system, which leads to a potent immune response. Herein, we report a facile approach to increase antigen size to achieve not only fast but also effective responses against the recombinant HA/H7N9 protein via a simple conjugation of the protein onto the surface of nanodiamond particles. In this study, trimeric Haemagglutinin (H7) that is transiently expressed in N. benthamiana was purified using affinity chromatography, and its trimeric state was revealed successfully by the cross-linking reaction. The trimeric H7 solution was subsequently mixed with a nanodiamond suspension in different rati...
Hydrology and Earth System Sciences Discussions, 2017
A hydrological impact analysis concerns the study of the consequences of certain scenarios on one... more A hydrological impact analysis concerns the study of the consequences of certain scenarios on one or more variables or fluxes in the hydrological cycle. In such exercise, discharge is often considered, as especially extreme high discharges often cause damage due to the coinciding floods. Investigating extreme discharges generally requires long time series of precipitation and evapotranspiration that are used to force a rainfall-runoff model. However, such kind of data may not be available and one should resort to stochastically-generated time series, even though the impact of using such data on the overall discharge, and especially on the extreme discharge events is not well studied. In this paper, stochastically-generated rainfall and coinciding evapotranspiration time series are used to force a simple conceptual hydrological model. The results obtained are comparable to the modelled discharge using observed forcing data. Yet, uncertainties in the modelled discharge increase with a...
PD patients/older adults, respectively, reached 99/99% accuracy. Similar results were obtained fo... more PD patients/older adults, respectively, reached 99/99% accuracy. Similar results were obtained for TO (99/100%). In HS detection, Bland-Altman plots showed a mean difference of 0.002 s [95% confidence interval (CI) −0.09 to 0.10] between the algorithm and the optoelectronic system. The Bland-Altman plot for TO detection showed mean differences of 0.00 s (95% CI −0.12 to 0.12). In the home-like assessment, the algorithm for detection of occurrence of steps during turning reached 90% (PD patients)/90% (older adults) sensitivity, 83/88% specificity, and 88/89% accuracy. The detection of steps during non-turning phases reached 91/91% sensitivity, 90/90% specificity, and 91/91% accuracy. Conclusion: This cwt-based algorithm for step detection measured at the lower back is in high agreement with the optoelectronic system in both PD patients and older adults. This approach and algorithm thus could provide a valuable tool for future research on home-based gait analysis in these vulnerable cohorts.
The re-emergence of community-based health workers such as the auxiliary midwives (AMWs) in Myanm... more The re-emergence of community-based health workers such as the auxiliary midwives (AMWs) in Myanmar, who are local female volunteers, has been an important strategy to address global health workforce shortages. The Myanmar government recommends one AMW for every village. The aim of this study is to investigate the current knowledge of critical danger signs and practices for safe childbirth and immediate newborn care of AMWs to inform potential task shifting of additional healthcare responsibilities. A cross-sectional survey was conducted from July 2015 to June 2016 in three hard-to-reach areas in Myanmar. Face-to-face interviews were conducted using a pretested questionnaire. Among 262 AMWs participating in the study, only 8% of AMWs were able to identify at least 80% of 20 critical danger signs. Factors associated with greater knowledge of critical danger signs included older age over 35 years (adjusted OR (AOR) 2.19, 95% CI 0.99 to 4.83), having received refresher training within ...
Regular monitoring of HIV patients who are receiving antiretroviral therapy (ART) is required to ... more Regular monitoring of HIV patients who are receiving antiretroviral therapy (ART) is required to ensure patient benefits and the long-term effectiveness and sustainability of ART programs. Prompted by WHO recommendations for expansion and decentralization of HIV treatment and care in low and middle income countries, we conducted a systematic review to assess the feasibility of treatment monitoring in these settings. A comprehensive search strategy was developed using a combination of MeSH and free text terms relevant to HIV treatment and care, health service delivery, health service accessibility, decentralization and other relevant terms. Five electronic databases and two conference websites were searched to identify relevant studies conducted in LMICs, published in English between Jan 2006 and Dec 2015. Outcomes of interest included the proportion of patients who received treatment monitoring and health system factors related to monitoring of patients on ART under decentralized HI...
Point-of-care (POC) CD4 testing increases patient accessibility to assessment of antiretroviral t... more Point-of-care (POC) CD4 testing increases patient accessibility to assessment of antiretroviral therapy eligibility. This review evaluates field performance in low and middle-income countries (LMICs) of currently available POC CD4 technologies. Eight electronic databases were searched for field studies published between January 2005 and January 2015 of six POC CD4 platforms: PointCare NOW™, Alere Pima™ CD4, Daktari™ CD4 Counter, CyFlow® CD4 miniPOC, BD FACSPresto™, and MyT4™ CD4. Due to limited data availability, meta-analysis was conducted only for diagnostic performance of Pima at a threshold of 350 cells/μl, applying a bivariate multi-level random-effects modelling approach. A covariate extended model was also explored to test for difference in diagnostic performance between capillary and venous blood. Twenty seven studies were included. Published field study results were found for three of the six POC CD4 tests, 24 of which used Pima. For Pima, test failure rates varied from 2 t...
Progress in achieving maternal health goals and the rates of reductions in deaths from individual... more Progress in achieving maternal health goals and the rates of reductions in deaths from individual conditions have varied over time and across countries. Assessing whether research priorities in maternal health align with the main causes of mortality, and those factors responsible for inequitable health outcomes, such as health system performance, may help direct future research. The study thus investigated whether the research done in low- and middle-income countries (LMICs) matched the principal causes of maternal deaths in these settings. Systematic mapping was done of maternal health interventional research in LMICs from 2000 to 2012. Articles were included on health systems strengthening, health promotion; and on five tracer conditions (haemorrhage, hypertension, malaria, HIV and other sexually transmitted infections (STIs)). Following review of 35,078 titles and abstracts in duplicate, data were extracted from 2292 full-text publications. Over time, the number of publications ...
Most cancer-associated deaths result from metastasis. However, it remains unknown whether the siz... more Most cancer-associated deaths result from metastasis. However, it remains unknown whether the size, microenvironment or other features of a metastatic lesion dictate its behaviour or determine the efficacy of chemotherapy in the adjuvant (micrometastatic) setting. Here we delineate the natural history of metastasis in an autochthonous model of pancreatic ductal adenocarcinoma (PDAC), using lineage tracing to examine the evolution of disseminated cancer cells and their associated microenvironment. With increasing size, lesions shift from mesenchymal to epithelial histology, become hypovascular and accumulate a desmoplastic stroma, ultimately recapitulating the primary tumours from which they arose. Moreover, treatment with gemcitabine and nab-paclitaxel significantly reduces the overall number of metastases by inducing cell death in lesions of all sizes, challenging the paradigm that PDAC stroma imposes a critical barrier to drug delivery. These results illuminate the cellular dynami...
CD4 testing is, and will remain an important part of HIV treatment and care in low and middle inc... more CD4 testing is, and will remain an important part of HIV treatment and care in low and middle income countries (LMICs). We report the findings of a systematic review assessing acceptability and feasibility of POC CD4 testing in field settings. Electronic databases were searched for studies published in English between 2005 and 2015 that describe POC CD4 platforms. Studies conducted in LMICs and under field conditions outside a laboratory environment were eligible. Qualitative and descriptive data analysis was used to present the findings. Twelve studies were included, 11 of which were conducted in sub-Saharan countries and used one POC CD4 test (The Alere Pima CD4). Patients reported positively regarding the implementation of POC CD4 testing at primary health care and community level with ≥90 % of patients accepting the test across various study settings. Health service providers expressed preference toward POC CD4 testing as it is easy-to-use, efficient and satisfied patients' ...
Stochastic Environmental Research and Risk Assessment, 2015
Evapotranspiration is an important process in the water cycle that represents a considerable amou... more Evapotranspiration is an important process in the water cycle that represents a considerable amount of moisture lost to the atmosphere through evaporation from the soil and wet surfaces, and transpiration from plants. Therefore, several water management methods, such as irrigation scheduling and hydrological impact analysis, rely on an accurate estimation of evapotranspiration rates. Often, daily reference evapotranspiration is modelled based on the Penman, Priestley-Taylor or Hargraeves equation. However, each of these models requires extensive input data, such as daily mean temperature, wind speed, relative humidity and solar radiation. Yet, in design studies, such data may be unavailable and therefore, another approach may be needed that is based on stochastically generated time series. More specifically, when rainfall-runoff models are used, these evapotranspiration data need to be consistent with the accompanying (stochastically generated) precipitation time series data. In this paper, such an approach is presented in which the statistical dependence between evapotranspiration, precipitation and temperature is described by three-and four-dimensional vine copulas. Based on a case study of 72 years of evapotranspiration, temperature and precipitation data, observed in Uccle, Belgium, it is shown that canonical vine copulas (C-vines) perform very well in preserving the dependences between variables.
2014 IEEE International Conference on Robotics and Automation (ICRA), 2014
A pneumatic actuator with solenoid valves is a discontinuous-input system because each valve can ... more A pneumatic actuator with solenoid valves is a discontinuous-input system because each valve can be either in on or off state. For such an actuator, this paper proposes a sliding-mode control scheme based on an averaged continuousinput equivalent model for the open-loop system. The averaged model is obtained from the nonlinear dynamics of the open-loop discontinuous-input system undergoing pulse-width-modulation (PWM) at the input (i.e., valve open/close action). The PWM duty cycle will be regarded as a continuous input to the proposed averaged model, and thus generated by the proposed sliding-mode controller. By adjusting the PWM duty cycle, the controller switches between seven modes of operation of the open-loop system in order to select the ones with necessary and sufficient amounts of drive energy to achieve position tracking. We will show that this results in reduced position error and valve switching activity for the actuator. The proposed control scheme is experimentally used in the position control of a pneumatic actuator and the results are presented.
2009 IEEE International Conference on Systems, Man and Cybernetics, 2009
Most conventional methods of feature extraction for pattern recognition do not pay sufficient att... more Most conventional methods of feature extraction for pattern recognition do not pay sufficient attention to inherent geometric properties of data, even in the case where the data have spatial features. This paper introduces geometric algebra to extract invariant geometric features from spatial data given in a vector space. Geometric algebra is a multidimensional generalization of complex numbers and of quaternions, and it ables to accurately describe oriented spatial objects and relations between them. This paper proposes to combine several geometric features using Gaussian mixture models. It applies the proposed method to the classification of handwritten digits.
In the last few decades, the frequency and intensity of water-related disasters, also called clim... more In the last few decades, the frequency and intensity of water-related disasters, also called climate-related disasters, e.g. floods, storms, heat waves and droughts, has gone up considerably at both global and regional scales, causing significant damage to many societies and ecosystems. Understanding the behavior and frequency of these disasters is extremely important, not only for reducing their damages but also for the management of water resources. These disasters can often be characterized by multiple dependent variables and therefore require a flexible multivariate approach for studying such phenomena. In this study, we focus on copulas, which are multivariate functions that describe the dependence structure between stochastic variables, independently of their marginal behaviors. The study aimed at different potential applications of copulas in hydrology, such as a multivariate frequency analysis and a copula-based approach for assessing a rainfall model. And further, a stochas...
Background Treatment of HIV with antiretroviral therapy (ART) can improve the health of people li... more Background Treatment of HIV with antiretroviral therapy (ART) can improve the health of people living with HIV (PLHIV), stop onward transmission of HIV and effectively prevent the spread of the virus. In 2016, we conducted a systematic review to assess the feasibility of treatment monitoring for PLHIV on ART in low and middle-income countries (LMICs), in line with the 90-90-90 treatment target. By 2020, global estimates suggest the 90-90-90 target remains unattainable in many LMICs. This study aims to review the progress and identify needs for public health interventions to improve viral load monitoring and viral suppression for PLHIV in LMICs. Methods A literature search was conducted using an update of the initial search strategy developed for the 2016 review with key search terms relevant to HIV treatment and care, decentralization and viral load monitoring. Electronic databases (Medline and PubMed) were searched to identify relevant literature published in English between Dec 20...
In this paper, we present our methods for unrealiable information identification task at ReINTEL ... more In this paper, we present our methods for unrealiable information identification task at ReINTEL Challenge 2020. The task is to classify a piece of information into reliable or unreliable category. We propose a novel multimodal ensemble model which combines two multimodal models to solve the task. In each multimodal model, we combined feature representations acquired from three different data types: texts, images, and metadata. Multimodal features are derived from three neural networks and fused for classification. Experimental results showed that our proposed ensemble model improved against single models in term of AUC score. We obtained 0.9445 AUC score on the private test of the challenge.
The advent of telerobotic systems has revolutionized various aspects of the industry and human li... more The advent of telerobotic systems has revolutionized various aspects of the industry and human life. This technology is designed to augment human sensorimotor capabilities to extend them beyond natural competence. Classic examples are space and underwater applications when distance and access are the two major physical barriers to be combated with this technology. In modern examples, telerobotic systems have been used in several clinical applications, including teleoperated surgery and telerehabilitation. In this regard, there has been a significant amount of research and development due to the major benefits in terms of medical outcomes. Recently telerobotic systems are combined with advanced artificial intelligence modules to better share the agency with the operator and open new doors of medical automation. In this review paper, we have provided a comprehensive analysis of the literature considering various topologies of telerobotic systems in the medical domain while shedding li...
In this paper, we evaluate end-to-end outage probability of a multi-hop decode-and-forward relayi... more In this paper, we evaluate end-to-end outage probability of a multi-hop decode-and-forward relaying protocol in underlay cognitive radio network. In the proposed protocol, named COOP, secondary nodes including source and relays have to harvest radio-frequency energy from multiple secondary power beacons, and adjust their transmit power, follows a pre-determined interference threshold given by multiple primary users. To enhance the outage performance for the secondary network under an joint constraint of the interference threshold, Rayleigh fading channel and hardware noises caused by imperfect transceiver hardware, the secondary relays on the source-destination path cooperate to forward the source data to the destination. Particularly, they attempt to receive the source data from their previous nodes, and forward it to the secondary destination if requested. Moreover, whenever the destination cannot receive the source data successfully, a successful relay that has the shortest dista...
Parkinson's disease (PD) is a neurodegenerative movement disorder associated with gait and ba... more Parkinson's disease (PD) is a neurodegenerative movement disorder associated with gait and balance problems and a substantially increased risk of falling. Falls occur often during complex movements, such as turns. Both fear of falling (FOF) and previous falls are relevant risk factors for future falls. Based on recent studies indicating that lab-based and home assessment of similar movements show different results, we hypothesized that FOF and a positive fall history would influence the quantitative turning parameters differently in the laboratory and home. Fifty-five PD patients (43 underwent a standardized lab assessment; 40 were assessed over a mean of 12 days at home with approximately 10,000 turns per participant; and 28 contributed to both assessments) were classified regarding FOF and previous falls as "vigorous" (no FOF, negative fall history), "anxious" (FOF, negative fall history), "stoic" (no FOF, positive fall history) and "aware&qu...
Undernutrition remains a significant cause of childhood illness, poor growth, development, and de... more Undernutrition remains a significant cause of childhood illness, poor growth, development, and death in Papua New Guinea (PNG). Studies on child nutritional outcomes in PNG vary by design, measurement protocols and quality. We conducted a systematic review to assess the evidence for the prevalence of child undernutrition across different study populations, geographical locations and time periods. Six electronic databases and additional grey literature were searched for articles describing the nutritional status by wasting, stunting and underweight, of PNG children under five years of age, published between 1990 and April 2015. Prevalence data using different scales of measurement and reference populations were standardized according to WHO protocols. The search yielded 566 articles, of which, 31 studies met the inclusion criteria. The prevalence of child undernutrition varied from 1% to 76% for wasting (median 11%), 5% to 92% for stunting (median 51%), and 14% to 59% for underweight...
The continuing spread of the newly emerged H7N9 virus among poultry in China, as well as the poss... more The continuing spread of the newly emerged H7N9 virus among poultry in China, as well as the possibility of human-to-human transmission, has attracted numerous efforts to develop an effective vaccine against H7N9. The use of nanoparticles in vaccinology is inspired by the fact that most pathogens have a dimension within the nano-size range and therefore can be processed efficiently by the immune system, which leads to a potent immune response. Herein, we report a facile approach to increase antigen size to achieve not only fast but also effective responses against the recombinant HA/H7N9 protein via a simple conjugation of the protein onto the surface of nanodiamond particles. In this study, trimeric Haemagglutinin (H7) that is transiently expressed in N. benthamiana was purified using affinity chromatography, and its trimeric state was revealed successfully by the cross-linking reaction. The trimeric H7 solution was subsequently mixed with a nanodiamond suspension in different rati...
Hydrology and Earth System Sciences Discussions, 2017
A hydrological impact analysis concerns the study of the consequences of certain scenarios on one... more A hydrological impact analysis concerns the study of the consequences of certain scenarios on one or more variables or fluxes in the hydrological cycle. In such exercise, discharge is often considered, as especially extreme high discharges often cause damage due to the coinciding floods. Investigating extreme discharges generally requires long time series of precipitation and evapotranspiration that are used to force a rainfall-runoff model. However, such kind of data may not be available and one should resort to stochastically-generated time series, even though the impact of using such data on the overall discharge, and especially on the extreme discharge events is not well studied. In this paper, stochastically-generated rainfall and coinciding evapotranspiration time series are used to force a simple conceptual hydrological model. The results obtained are comparable to the modelled discharge using observed forcing data. Yet, uncertainties in the modelled discharge increase with a...
PD patients/older adults, respectively, reached 99/99% accuracy. Similar results were obtained fo... more PD patients/older adults, respectively, reached 99/99% accuracy. Similar results were obtained for TO (99/100%). In HS detection, Bland-Altman plots showed a mean difference of 0.002 s [95% confidence interval (CI) −0.09 to 0.10] between the algorithm and the optoelectronic system. The Bland-Altman plot for TO detection showed mean differences of 0.00 s (95% CI −0.12 to 0.12). In the home-like assessment, the algorithm for detection of occurrence of steps during turning reached 90% (PD patients)/90% (older adults) sensitivity, 83/88% specificity, and 88/89% accuracy. The detection of steps during non-turning phases reached 91/91% sensitivity, 90/90% specificity, and 91/91% accuracy. Conclusion: This cwt-based algorithm for step detection measured at the lower back is in high agreement with the optoelectronic system in both PD patients and older adults. This approach and algorithm thus could provide a valuable tool for future research on home-based gait analysis in these vulnerable cohorts.
The re-emergence of community-based health workers such as the auxiliary midwives (AMWs) in Myanm... more The re-emergence of community-based health workers such as the auxiliary midwives (AMWs) in Myanmar, who are local female volunteers, has been an important strategy to address global health workforce shortages. The Myanmar government recommends one AMW for every village. The aim of this study is to investigate the current knowledge of critical danger signs and practices for safe childbirth and immediate newborn care of AMWs to inform potential task shifting of additional healthcare responsibilities. A cross-sectional survey was conducted from July 2015 to June 2016 in three hard-to-reach areas in Myanmar. Face-to-face interviews were conducted using a pretested questionnaire. Among 262 AMWs participating in the study, only 8% of AMWs were able to identify at least 80% of 20 critical danger signs. Factors associated with greater knowledge of critical danger signs included older age over 35 years (adjusted OR (AOR) 2.19, 95% CI 0.99 to 4.83), having received refresher training within ...
Regular monitoring of HIV patients who are receiving antiretroviral therapy (ART) is required to ... more Regular monitoring of HIV patients who are receiving antiretroviral therapy (ART) is required to ensure patient benefits and the long-term effectiveness and sustainability of ART programs. Prompted by WHO recommendations for expansion and decentralization of HIV treatment and care in low and middle income countries, we conducted a systematic review to assess the feasibility of treatment monitoring in these settings. A comprehensive search strategy was developed using a combination of MeSH and free text terms relevant to HIV treatment and care, health service delivery, health service accessibility, decentralization and other relevant terms. Five electronic databases and two conference websites were searched to identify relevant studies conducted in LMICs, published in English between Jan 2006 and Dec 2015. Outcomes of interest included the proportion of patients who received treatment monitoring and health system factors related to monitoring of patients on ART under decentralized HI...
Point-of-care (POC) CD4 testing increases patient accessibility to assessment of antiretroviral t... more Point-of-care (POC) CD4 testing increases patient accessibility to assessment of antiretroviral therapy eligibility. This review evaluates field performance in low and middle-income countries (LMICs) of currently available POC CD4 technologies. Eight electronic databases were searched for field studies published between January 2005 and January 2015 of six POC CD4 platforms: PointCare NOW™, Alere Pima™ CD4, Daktari™ CD4 Counter, CyFlow® CD4 miniPOC, BD FACSPresto™, and MyT4™ CD4. Due to limited data availability, meta-analysis was conducted only for diagnostic performance of Pima at a threshold of 350 cells/μl, applying a bivariate multi-level random-effects modelling approach. A covariate extended model was also explored to test for difference in diagnostic performance between capillary and venous blood. Twenty seven studies were included. Published field study results were found for three of the six POC CD4 tests, 24 of which used Pima. For Pima, test failure rates varied from 2 t...
Progress in achieving maternal health goals and the rates of reductions in deaths from individual... more Progress in achieving maternal health goals and the rates of reductions in deaths from individual conditions have varied over time and across countries. Assessing whether research priorities in maternal health align with the main causes of mortality, and those factors responsible for inequitable health outcomes, such as health system performance, may help direct future research. The study thus investigated whether the research done in low- and middle-income countries (LMICs) matched the principal causes of maternal deaths in these settings. Systematic mapping was done of maternal health interventional research in LMICs from 2000 to 2012. Articles were included on health systems strengthening, health promotion; and on five tracer conditions (haemorrhage, hypertension, malaria, HIV and other sexually transmitted infections (STIs)). Following review of 35,078 titles and abstracts in duplicate, data were extracted from 2292 full-text publications. Over time, the number of publications ...
Most cancer-associated deaths result from metastasis. However, it remains unknown whether the siz... more Most cancer-associated deaths result from metastasis. However, it remains unknown whether the size, microenvironment or other features of a metastatic lesion dictate its behaviour or determine the efficacy of chemotherapy in the adjuvant (micrometastatic) setting. Here we delineate the natural history of metastasis in an autochthonous model of pancreatic ductal adenocarcinoma (PDAC), using lineage tracing to examine the evolution of disseminated cancer cells and their associated microenvironment. With increasing size, lesions shift from mesenchymal to epithelial histology, become hypovascular and accumulate a desmoplastic stroma, ultimately recapitulating the primary tumours from which they arose. Moreover, treatment with gemcitabine and nab-paclitaxel significantly reduces the overall number of metastases by inducing cell death in lesions of all sizes, challenging the paradigm that PDAC stroma imposes a critical barrier to drug delivery. These results illuminate the cellular dynami...
CD4 testing is, and will remain an important part of HIV treatment and care in low and middle inc... more CD4 testing is, and will remain an important part of HIV treatment and care in low and middle income countries (LMICs). We report the findings of a systematic review assessing acceptability and feasibility of POC CD4 testing in field settings. Electronic databases were searched for studies published in English between 2005 and 2015 that describe POC CD4 platforms. Studies conducted in LMICs and under field conditions outside a laboratory environment were eligible. Qualitative and descriptive data analysis was used to present the findings. Twelve studies were included, 11 of which were conducted in sub-Saharan countries and used one POC CD4 test (The Alere Pima CD4). Patients reported positively regarding the implementation of POC CD4 testing at primary health care and community level with ≥90 % of patients accepting the test across various study settings. Health service providers expressed preference toward POC CD4 testing as it is easy-to-use, efficient and satisfied patients' ...
Stochastic Environmental Research and Risk Assessment, 2015
Evapotranspiration is an important process in the water cycle that represents a considerable amou... more Evapotranspiration is an important process in the water cycle that represents a considerable amount of moisture lost to the atmosphere through evaporation from the soil and wet surfaces, and transpiration from plants. Therefore, several water management methods, such as irrigation scheduling and hydrological impact analysis, rely on an accurate estimation of evapotranspiration rates. Often, daily reference evapotranspiration is modelled based on the Penman, Priestley-Taylor or Hargraeves equation. However, each of these models requires extensive input data, such as daily mean temperature, wind speed, relative humidity and solar radiation. Yet, in design studies, such data may be unavailable and therefore, another approach may be needed that is based on stochastically generated time series. More specifically, when rainfall-runoff models are used, these evapotranspiration data need to be consistent with the accompanying (stochastically generated) precipitation time series data. In this paper, such an approach is presented in which the statistical dependence between evapotranspiration, precipitation and temperature is described by three-and four-dimensional vine copulas. Based on a case study of 72 years of evapotranspiration, temperature and precipitation data, observed in Uccle, Belgium, it is shown that canonical vine copulas (C-vines) perform very well in preserving the dependences between variables.
2014 IEEE International Conference on Robotics and Automation (ICRA), 2014
A pneumatic actuator with solenoid valves is a discontinuous-input system because each valve can ... more A pneumatic actuator with solenoid valves is a discontinuous-input system because each valve can be either in on or off state. For such an actuator, this paper proposes a sliding-mode control scheme based on an averaged continuousinput equivalent model for the open-loop system. The averaged model is obtained from the nonlinear dynamics of the open-loop discontinuous-input system undergoing pulse-width-modulation (PWM) at the input (i.e., valve open/close action). The PWM duty cycle will be regarded as a continuous input to the proposed averaged model, and thus generated by the proposed sliding-mode controller. By adjusting the PWM duty cycle, the controller switches between seven modes of operation of the open-loop system in order to select the ones with necessary and sufficient amounts of drive energy to achieve position tracking. We will show that this results in reduced position error and valve switching activity for the actuator. The proposed control scheme is experimentally used in the position control of a pneumatic actuator and the results are presented.
2009 IEEE International Conference on Systems, Man and Cybernetics, 2009
Most conventional methods of feature extraction for pattern recognition do not pay sufficient att... more Most conventional methods of feature extraction for pattern recognition do not pay sufficient attention to inherent geometric properties of data, even in the case where the data have spatial features. This paper introduces geometric algebra to extract invariant geometric features from spatial data given in a vector space. Geometric algebra is a multidimensional generalization of complex numbers and of quaternions, and it ables to accurately describe oriented spatial objects and relations between them. This paper proposes to combine several geometric features using Gaussian mixture models. It applies the proposed method to the classification of handwritten digits.
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Papers by Minh Phạm