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Quillen proved that repeated multiplication of the standard sesquilinear form to a positive Hermitian bihomogeneous polynomial eventually results in a sum of Hermitian squares, which was the first Hermitian analogue of Hilbert’s seventeenth problem in the nondegenerate case. Later Catlin-D’Angelo generalized this positivstellensatz of Quillen to the case of Hermitian algebraic functions on holomorphic line bundles over compact complex manifolds by proving the eventual positivity of an associated integral operator. The arguments of Catlin-D’Angelo involve subtle asymptotic estimates of the Bergman kernel. In this article, the authors give an elementary and geometric proof of the eventual positivity of this integral operator, thereby yielding another proof of the corresponding positivstellensatz.

We consider positive Hermitian algebraic functions on holomorphic line bundles over compact complex manifolds. In particular, we consider the tensor product of positive powers of a positive Hermitian algebraic function satisfying the strong global Cauchy–Schwarz condition on a holomorphic line bundle with another fixed positive Hermitian algebraic function on another holomorphic line bundle. Our main result is to give an effective estimate (in terms of certain geometric data) on the smallest power needed to be taken so that the resulting tensor product is a maximal sum of Hermitian squares, or equivalently, the induced Hermitian metric on the resulting line bundle is the pull-back (via some holomorphic map) of the standard Hermitian metric on the universal line bundle over some complex projective space. This result is an effective version of Catlin–D’Angelo’s Hermitian Positivstellensatz.

Background and objectives Melanonychia striata is common in children of darker-skinned Asian races, while subungual melanoma is extremely rare and it is difficult to make a diagnosis clinically. However, performing nail unit biopsies in children is particularly challenging and can result in permanent nail dystrophy. The aim of this study was to review the clinical and histologic characteristics of melanonychia striata in pediatric patients of Asian descent to aid in the clinical decision regarding nail biopsy. Methods Sixty-two pediatric patients presenting with melanonychia striata involving single or multiple nails at two tertiary pediatric dermatology clinics in Singapore between 2005 and 2015 were reviewed. Clinical and histopathological data were analyzed, including age at onset, age at presentation, location, color, width, presence of Hutchinson's sign, pseudo-Hutchinson's sign, nail dystrophy, length of follow-up, and clinical evolution. Histopathological assessment was performed by three senior dermatopathologists independently for cases that underwent a nail biopsy. Results No cases of subungual melanoma were detected in our series. Solitary melanonychia of the thumbnail with a single uniform color was the most common presentation. Pseudo-Hutchinson's sign was commonly observed. Consensus in histological diagnosis emerged amongst all three dermatopathologists in only half of the cases biopsied. Conclusion The occurrence of melanoma in Asian children presenting with melanonychia is extremely rare. We recommend clinical follow-up and anticipatory guidance for these patients and nail unit biopsy only in the presence of high-risk clinical features.

Background Atopic dermatitis (AD) is a common, chronic dermatosis, with onset of disease often manifesting in early infancy. Past studies evaluating the early use of moisturisers in the prevention of AD had mixed results. Objectives To compare the incidence of moderate or severe AD and total incidence of AD in a cohort of 'at-risk' infants treated with moisturisers from the first 2 weeks of life, to a similar group without moisturisers. Methods We performed a single-centre, prospective, parallel-group, randomised study in infants with at least 2 first-degree relatives with atopy. Subjects were randomised into either a treatment group with moisturisers or a control group without moisturisers. Participants were assessed at 2, 6, and 12 months for AD and if present, the severity was assessed using SCORAD index. We also compared the overall incidence of AD, trans-epidermal water loss (TEWL), stratum corneum (SC) hydration, pH, and incidence of food and environmental sensitisation and allergies between both groups. Genotyping for loss-of-functions mutations in the FLG gene was conducted. Results A total of 200 subjects were recruited, with 100 subjects in each arm. There was no significant difference in incidence of moderate or severe AD, and total incidence of AD at 12 months between the treatment and control groups. There was a lower mean SCORAD in the treatment group than in the control group, but no significant difference in TEWL, SC hydration, and skin pH. No significant side-effects were reported. Conclusions The early use of moisturisers in 'at-risk' infants does not reduce the incidence of moderate-to-severe AD and overall incidence of AD in infancy.

This Innovative Practice category Full Paper presents the use of a state-of-the-art research problem for a capstone project for third year computer engineering students. In our university, students were given the opportunity to work on a cutting edge problem - indoor navigation systems for the visually impaired. Indoor navigation is challenging because GPS signals cannot be received indoors. It is an area where a large amount of research is ongoing, and hundreds of scientific papers are published every year. For a successful implementation of the system, students had to draw on their knowledge of all the computer engineering concepts, ranging from digital electronic circuits, microprocessors, real-time systems, data structures and algorithms, software engineering, computer networking etc. In addition, students had to evaluate and adopt techniques from existing literature, and adapt them to meet the problem requirements. Thus, the project reinforced their knowledge of fundamentals, while exposing them to a problem with no obvious solution. The main evaluation was conducted as a competition, where students were blindfolded and were required to navigate between two indoor locations. Their system had to download the maps from a server, compute the optimal route to the destination, and students had to navigate there based only on voice and/or haptic commands provided by their system. Some constraints were imposed to ensure that the problem did not get trivialized and accurately represented a real-world scenario. Quantitative and qualitative results from the module feedback surveys showed significant improvement over the previous capstone project. The surveys indicate that the nature of the project and the evaluation process provided adequate challenge and excitement to students, while facilitating effective learning. Students were able to exercise their creativity, and come up with a number of interesting positioning techniques. Such a project ensured that the learning process cemented their understanding of subject fundamentals while addressing a novel research problem that is current, and has a potentially huge societal and commercial impact.

In 2019, a novel coronavirus (SARS-CoV-2) was found to cause a highly contagious disease characterized by pneumonia. The disease (COVID-19) quickly spread around the globe, escalating to a global pandemic. In this review, we discuss the virological, immunological, and imaging approaches harnessed for COVID-19 diagnosis and research. COVID-19 shares many clinical characteristics with other respiratory illnesses. Accurate and early detection of the infection is pivotal to controlling the outbreak, as this enables case identification, isolation, and contact tracing. We summarize the available literature on current laboratory and point-of-care diagnostics, highlight their strengths and limitations, and describe the emerging diagnostic approaches on the horizon. We also discuss the various research techniques that are being used to evaluate host immunity in laboratory-confirmed patients. Additionally, pathological imaging of tissue samples from affected patients has a critical role in guiding investigations on this disease. Conventional techniques, such as immunohistochemistry and immunofluorescence, have been frequently used to characterize the immune microenvironment in COVID-19. We also outline the emerging imaging techniques, such as the RNAscope, which might also aid in our understanding of the significance of COVID-19-specific biomarkers, such as the angiotensin-converting enzyme 2 (ACE2) cellular receptor. Overall, great progress has been made in COVID-19 research in a short period. Extensive, global collation of our current knowledge of SARS-CoV-2 will provide insights into novel treatment modalities, such as monoclonal antibodies, and support the development of a SARS-CoV-2 vaccine.

Introduction Adrenal venous sampling (AVS) is the reference test for identifying unilateral primary aldosteronism (PA). However, in patients with corticol co-secreting adrenal nodules, elevated cortisol levels may affect the interpretation of aldosterone-cortisol (AC) ratios. ACTH-stimulation may further confound results. In such patients, the use of plasma metanephrines instead of cortisol as a correcting factor may be helpful. Case Summary A 54 year old lady presented with 8 years of hypertension and hypokalaemia (nadir 2.2mmol/L) while on amlodipine 10mg and valsartan 80mg daily. PA was confirmed by a post-saline infusion aldosterone 1075pmol/L. CT identified a 2.4cm right lipid rich adrenal adenoma. Serum cortisol post 1mg overnight dexa-suppression test was unsuppressed at 63mmol/L. First AVS was done sequentially under ACTH stimulation and suggested lateralization to the right, with lateralization ratio (LR) 3.4. However, this was She underwent right adrenalectomy and was cured of hypertension and hypokalaemia at 6 months post surgery. Aldosterone renin ratio has normalized: aldosterone Clinical Lessons While ACTH stimulation helps to improve success rates of cannulation by increasing cortisol gradients, most studies show that it lowers LR. Furthermore, this would be concerning in patients with cortisol co-secreting adenomas. In this case, repeat AVS without ACTH demonstrated improved lateralization to the right. The use of metanephrine as a correcting factor appears to be a better indicator of right sided disease. However, while plasma metanephrines have been shown to be useful to indicate correct catheter placement, it has not been adopted as a correction factor for dilution yet. Finally, in addition to affecting AVS results, cortisol-cosecreting tumors may also affect 11C-Metomidate PET-CT imaging. Conclusion In patients with suspected cortisol co-secreting adenomas, unstimulated AVS and use of plasma metanephrines may help to identify unilateral PA even when conventional AVS and metomidate scans fail to. Further studies on using metanephrines as a correcting factor for lateralisation would be helpful.

The concept of theranostics, where individual patient-level biological information is used to choose the optimal therapy for that individual, has become more popular in the modern era of 'personalised' medicine. With the growth of theranostics, nuclear medicine as a specialty is uniquely poised to grow along with the ever-increasing number of concepts combining imaging and therapy. This special report summarises the status and growth of Theranostic Nuclear Medicine in Singapore. We will cover our experience with the use of radioiodine, radioiodinated metaiodobenzylguanidine, peptide receptor radionuclide therapy, prostate specific membrane antigen radioligand therapy, radium-223 and yttrium-90 selective internal radiation therapy. We also include a section on our radiopharmacy laboratory, crucial to our implementation of theranostic principles. Radionuclide theranostics has seen tremendous growth and we hope to be able to grow alongside to continue to serve the patients in Singapore and in the region.

Introduction. Adrenal vein sampling (AVS) is the current reference test to identify unilateral, surgically-curable primary aldosteronism (PA). However, AVS is invasive and technically difficult. Even in AVS-proven unilateral PA, up to 6% of patients with fail to have biochemical cure after surgery using the PASO criteria. 11C-Metomidate PET-CT offers a non-invasive alternative. We compared the accuracy of both PET-CT and AVS using post-surgery cure (PASO criteria) as the reference. Methods. This multi-centre prospective trial recruited 25 patients with confirmed PA, and all underwent CT, AVS, and PET-CT tests. Sequential AVS under ACTH-stimulation was done by an experienced interventionalist, and cortisol gradient of >5 was taken to be successful cannulation. Lateralization ratio >4 was consistent with unilateral PA. All results were reviewed at a multidisciplinary meeting to decide on the diagnosis (unilateral or bilateral PA) and management (secondary outcome). Primary outcome was biochemical cure using PASO criteria at 6 months post-surgery (ClinicalTrials.gov: NCTxxxxxxxx). Results. Recruitment for the study has been complete with 25 patients, 49.2 ± 9.5 yr, 14 females (56.0%). All 25 patients had successful AVS. 22 of 25 patients (88.0%) had unilateral PA, and 3 patients (12.0%) had bilateral PA. PET-CT identified unilateral PA in 18 of 22 patients (sensitivity 81.8%), while AVS identified unilateral PA in 15 of 22 patients (sensitivity 68.2%). In one patient, repeat AVS done simultaneously without ACTH-stimulation aided to identify unilateral PA, when initial AVS failed to do so. Other cases where AVS failed to identify unilateral PA were due to venous anomalies, and limitation of the lateralization cut-off of 4. 18 of 22 patients have undergone surgery, with 3 patients awaiting surgery, and 1 opting for medical treatment. Post-surgery, all patients had complete normalization of aldosterone-renin ratio, and hypokalemia (if present). 2 patients had bilateral PA on both PET-CT and AVS. 1 patient had discordant AVS and PET-CT results, with AVS lateralizing to right, and PET-CT to left. This patient was classified as bilateral PA and treated medically. Conclusion. This is the first study to demonstrate that 11C-Metomidate PET-CT may identify cases of unilateral PA not detected with AVS, using the stringent PASO criteria for post-operative biochemical cure.

To develop consensus terminology in the setting of polypoidal choroidal vasculopathy (PCV) and to develop and validate a set of diagnostic criteria not requiring indocyanine green angiography (ICGA) for differentiating PCV from typical neovascular age-related macular degeneration (nAMD) based on a combination of OCT and color fundus photography findings.Evaluation of diagnostic test results.Panel of retina specialists.As part of the Asia-Pacific Ocular Imaging Society, an international group of experts surveyed and discussed the published literature regarding the current nomenclature and lesion components for PCV, and proposed an updated consensus nomenclature that reflects our latest understanding based on imaging and histologic reports. The workgroup evaluated a set of diagnostic features based on OCT images and color fundus photographs for PCV that may distinguish it from typical nAMD and assessed the performance of individual and combinations of these non-ICGA features, aiming to propose a new set of diagnostic criteria that does not require the use of ICGA. The final recommendation was validated in 80 eyes from 2 additional cohorts.Consensus nomenclature system for PCV lesion components and non-ICGA-based criteria to differentiate PCV from typical nAMD.The workgroup recommended the terms polypoidal lesion and branching neovascular network for the 2 key lesion components in PCV. For the diagnosis of PCV, the combination of 3 OCT-based major criteria (sub-retinal pigment epithelium [RPE] ring-like lesion, en face OCT complex RPE elevation, and sharp-peaked PED) achieved an area under the receiver operating characteristic curve of 0.90. Validation of this new scheme in a separate subset 80 eyes achieved an accuracy of 82%.We propose updated terminology for PCV lesion components that better reflects the nature of these lesions and is based on international consensus. A set of practical diagnostic criteria applied easily to spectral-domain OCT results can be used for diagnosing PCV with high accuracy in clinical settings in which ICGA is not performed routinely.

Let $p$ be a nonconstant form in $\mathbb{R}[x_1,\dots,x_n]$ with $p(1,\dots,1)>0$. If $p^m$ has strictly positive coefficients for some integer $m\ge1$, we show that $p^m$ has strictly positive coefficients for all sufficiently large $m$. More generally, for any such $p$, and any form $q$ that is strictly positive on $(\mathbb{R}_+)^n\setminus\{0\}$, we show that the form $p^mq$ has strictly positive coefficients for all sufficiently large $m$. This result can be considered as a strict Positivstellensatz for forms relative to $(\mathbb{R}_+)^n\setminus\{0\}$. We give two proofs, one based on results of Handelman, the other on techniques from real algebra., 11 pages

Radiology is a unique medical specialty that focuses on image interpretation and report generation with limited patient contact. Resident read-out sessions with teaching are a quintessential part of reporting workflow practices in teaching institutions. However, most radiologist-educators do not have formal training in teaching and learning experiences vary. The five-step 'microskills' model ('one-minute preceptor' technique) developed by Neher is an easily adopted teaching model that complements the workflow of the typical read-out session, and can be utilised by radiologists of varied teaching experience and seniority. The steps are: (a) get a commitment; (b) probe for supporting evidence; (c) teach general rules; (d) reinforce what was done right; and (e) correct mistakes. Feedback is important to the model and accounts for two out of five microskills. The teaching model emphasises knowledge application and establishing relevance, which is useful in engaging the millennial resident. It is easily assimilated and applied by radiologist-educators.

BackgroundA previously well 15-year-old girl presented with a 2-month history of facial swelling that progressively worsened to involve the neck. There was associated dyspnoea, orthopnoea, headache and throat discomfort. Two weeks before presentation, the patient had an episode of fever for 5 days. On examination, vital signs were within normal limits. Swelling, plethora and venous distension of the face and neck were apparent (figure 1).Figure 1(A) Patient before the onset of symptoms. (B) Patient at presentation.QuestionsWhat is the most likely diagnosis?Superior vena cava syndromeAngioedemaAnasarcaDiphtheriaDescribe the chest X-ray (figure 2).What are the acute concerns?What investigations would you order?Figure 2Chest X-ray of the patient at presentation.Answers can be found on page 02.

Let A be a based subspace of Y. Under the assumptions that Y is path-connected and that the reduced diagonal map of A induces the zero map in all mod 2 reduced homology groups, we compute a formula for the mod 2 reduced Poincare series of the loop space Ω ( ( A ∧ R P ∞ ) ∪ A ∧ R P 1 ( Y ∧ R P 1 ) ) . Here R P ∞ and R P 1 denote the infinite real projective space and the real projective line respectively.

This Innovative Practice Category Full Paper, analyses the effect of a game-based student response system to enhance experiential learning. The introductory engineering course offered for the freshman computer engineering cohort is designed with engineering practice at its core. Each week, the students spend two three-hour studio sessions experiencing engineering through hands-on practical applications followed by a two-hour reflective session. Among the two studios each week, only one is graded. The graded studios are designed with questions that supplement the practical application and spark reflective thinking. Consecutively, it is a good indicator of the effectiveness of the session. The ungraded studio sessions are designed the same as the graded ones but lack indicators of their efficacy for active implementation. To address this, an online game-based response system, Kahoot! is integrated with the ungraded studio sessions. Kahoot! combines game-based learning with the ease of a student response system that is useful in creating a stimulating environment and targets the competitive nature of students to supplement the ungraded studios. Kahoot! stands out from ordinary student response systems as it integrates a response time to the student’s answers. Both qualitative and quantitative assessment results on the effectiveness of Kahoot! to augment experiential learning will be presented.

Pre-hospital triage strategies aim to identify the type and extent of patient injuries and ensure that they are transferred to the most appropriate trauma centres. Despite the importance of appropriate pre-hospital transport, there is little evidence base to assist medical staff on optimal destination policy for emergent pre-hospital transport. This paper explores the spatial relationship of patient transfers prior to the implementation of the Midland Pre-Hospital Trauma Destination Matrix in New Zealand, and is a retrospective view of practice against a destination policy that was applied after the study period.We use data obtained from the Midland Trauma Registry merged with Global Positioning System (GPS) data from St John and Land Information New Zealand Data Service on major trauma occurring in 2014 and 2015. Using ArcGIS, data were analysed for spatial relationships between factors associated with major trauma events and pre-hospital transportation.In the retrospective analysis of 162 major trauma patients, 107 (66%) were transported to a hospital that matched the destination specified in the Matrix, and 55 (34%) were transported to a non-Matrix designated hospital.Approximately one-third of patients were not directly transported to the preferred definitive care hospital subsequently defined in the Midland Pre-Hospital Trauma Destination Matrix. Ongoing monitoring of the pre-hospital transportation system and the implementation of a formal pre-hospital transport policy may improve the efficiency of the Midland Trauma System. Future studies should examine the possible reasons for variations in triage decisions across the Midland Region.

Quillen proved that, if a Hermitian bihomogeneous polynomial is strictly positive on the unit sphere, then repeated multiplication of the standard sesquilinear form to this polynomial eventually results in a sum of Hermitian squares. Catlin-D'Angelo and Varolin deduced this positivstellensatz of Quillen from the eventual positive-definiteness of an associated integral operator. Their arguments involve asymptotic expansions of the Bergman kernel. The goal of this article is to give an elementary proof of the positive-definiteness of this integral operator., Article accepted by Chin. Ann. Math. Ser. B

As the Semantic Web is an open, complex and constantly evolving medium, it is the norm, but not exception that information at different sites is incomplete or inconsistent. This poses challenges for the engineering and development of agent systems on the Semantic Web, since autonomous software agents need to understand, process and aggregate this information. Ontology language OWL provides core language constructs to semantically markup resources on the Semantic Web, on which software agents interact and cooperate to accomplish complex tasks. However, as OWL was designed on top of (a subset of) classic predicate logic, it lacks the ability to reason about inconsistent or incomplete information. Belief-augmented Frames (BAF) is a frame-based logic system that associates with each frame a supporting and a refuting belief value. In this paper, we propose a new ontology language Belief-augmented OWL (BOWL) by integrating OWL DL and BAF to incorporate the notion of confidence. BOWL is paraconsistent, hence it can perform useful reasoning services in the presence of inconsistencies and incompleteness. We define the abstract syntax and semantics of BOWL by extending those of OWL. We have proposed reasoning algorithms for various reasoning tasks in the BOWL framework and we have implemented the algorithms using the constraint logic programming framework. One example in the sensor fusion domain is presented to demonstrate the application of BOWL.

With an aging Singapore population, there is an increasing demand for dementia care. The present study aimed to evaluate the effectiveness and cost-effectiveness of the Primary Care Dementia Clinic (PCDC) in comparison with the Memory Clinic (MC; hospital-based) and other polyclinics.A quasi-experimental design was implemented. Effectiveness of PCDC was assessed through caregiver satisfaction, quality of life (caregiver-rated) and adverse events rates. Quality-of-Life measures using the EuroQol 5 Dimension Questionnaire (EQ-5D) at baseline, 6 months and 12 months was assessed. Costs were calculated from a societal perspective. The incremental cost-effectiveness of the PCDC was compared with MC and other polyclinics.The present study showed that quality of life and the rate of adverse events at 12 months were similar between the three groups. Caregiver satisfaction at 12 months was higher in the PCDC group when compared with other polyclinics. There were no observed differences in societal cost between the three groups. At 6-month follow up, direct medical costs for PCDC were significantly lower that of other polyclinics. At 12-month follow up, PCDC patients had higher Quality Adjusted Life Years (QALYs) compared with the MC group.PCDC provided effective care, similar to care at MC and better than care at other polyclinics. Caregiver satisfaction was higher for the PCDC group, and PCDC patients had lower direct medical costs at 6-month follow up. Given these findings, adopting a PCDC model in other polyclinics in Singapore can be beneficial for optimal right siting of patients. Geriatr Gerontol Int 2018; 18: 479-486.

We give a criterion which characterizes a homogeneous real multi-variate polynomial to have the property that all sufficiently large powers of the polynomial (as well as their products with any given positive homogeneous polynomial) have positive coefficients. Our result generalizes a result of De Angelis, which corresponds to the case of homogeneous bi-variate polynomials, as well as a classical result of P\'olya, which corresponds to the case of a specific linear polynomial. As an application, we also give a characterization of certain polynomial beta functions, which are the spectral radius functions of the defining matrix functions of Markov chains., Comment: 15 pages

The pendant bipyridyl moiety of transition metal σ-acetylide complexes incorporating the 5-ethynyl-2,2′-bipyridine moiety provides a site of chelation for additional metal centers and facile access to multinuclear complexes as model systems for organometallic “molecular wires”. The mononuclear complexes [CpRu(CO)2(C2bpy)] (Cp = C5H5, C5Me5) and [RuCl(P∩P)2(C2bpy)] (P∩P = dppm, dppe) have been synthesized and characterized through spectroscopic means, providing context for the synthesis and spectroscopic characterization of the heterometallic coordination complex [RuCl(dppe)2(C2bpy-κ2-N,N′-PdCl2)]. A number of the complexes were further characterized by solid-state X-ray structural determinations. These studies were extended to other metal ligand systems, and the structures of the tris-bidentate ruthenium(II) complex [Ru(bpy)2(5-ethynyl-2,2′-bipyridine)](PF6)2 and gold(I) σ-alkynyl complexes [(PR3)Au(C2bpy)] (PR3 = PEt3, PPh3) are reported.

Background A recent study by the International Study of Asthma and Allergies in Childhood has shown that asthma symptom prevalence is still increasing in parts of Asia. As such, it is important to know how well asthma is being managed. Practices of physicians in India, China, Sri Lanka, Australia, Singapore, Indonesia, Philippines, and Taiwan in monitoring and treating childhood asthma were examined.Methods A 6-page standardized questionnaire was sent to physicians via post. The questionnaire is made up of 3 parts, including (1) methods of monitoring of childhood asthma, (2) practices in managing acute asthma exacerbations, and (3) choice of therapy in maintenance treatment.Results Our study reflects mostly the practices of physicians who practice in urban regions. Of respondents, 41.4% were general pediatricians, whereas 26.3% were general practitioners. A small fraction of physicians used score cards or diaries to monitor asthma, ranging from 0% (Philippines and Australia) to 15.9% (India). Only 8.1% (Sri Lanka) to 52.0% (Australia) use either a peak flow meter and/or spirometry to monitor asthma. However, for frequency of use, 35% (China) to 94% (Indonesia) never or seldom make use of a peak flow meter, and 33% (China) to 97.6% (Indonesia) never or seldom use spirometry for monitoring. Most physicians treat acute asthma appropriately with short-acting bronchodilators. For maintenance treatment, an inhaled corticosteroid was the most frequently chosen first-choice therapy. However, a significant fraction of physicians chose a long-acting β-agonist monotherapy as a first-choice treatment for asthma maintenance. For infants, the percentage ranged from 1.4% (Australia) to 76.3% (Indonesia); in preschoolers, 1.8% (Australia) to 43.3% (Indonesia); and in older children, 0% (Philippines) to 28.8% (Indonesia). These results may be related to the overall affluence of each nation.Conclusions There is much room for improvement in increasing physicians' awareness to guidelines for more effective management of pediatric asthma in Southeast Asia, especially regarding the high use of long-acting β-agonist monotherapy, even in young children. Keywords: childhood asthma, physicians, questionnaire, Southeast Asia

The Ministry of Health (MOH) has developed the clinical practice guidelines on Anxiety Disorders to provide doctors and patients in Singapore with evidence-based treatment for anxiety disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on anxiety disorders, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

This paper discusses the significance of participation with end users with the other stakeholders and multidisciplinary collaboration in the design process for the creation of applications for societal development. We have applied the participatory design approach in two different scenarios: (1) in the context of designing tablet apps for autistic children and (2) in the context of designing a chat room for math students. In each context, we (a) inform the design process through a background research and (b) incorporate participatory design and collaboration with stakeholders into the design and evaluation process. Presenting both cases, we intend to discuss the problems and opportunities of participatory approaches for designing applications for societal development. In conclusion, the participatory design process allows highly particular responses and reactions of stakeholders which enriches the evolutionary design process.

Wireless sensor networks (WSNs) typically consist of sensor nodes and gateways that operate on devices with limited resources. As a result, WSNs require bandwidth-efficient and energy-efficient application protocols for data transmission. Message Queue Telemetry Transport (MQTT) and Constrained Application Protocol (CoAP) are two such protocols proposed for resource-constrained devices. In this paper, we design and implement a common middleware that supports MQTT and CoAP and provides a common programming interface. We design the middleware to be extensible to support future protocols. Using the common middleware, we conducted experiments to study the performance of MQTT and CoAP in terms of end-to-end delay and bandwidth consumption. Experimental results reveal that MQTT messages have lower delay than CoAP messages at lower packet loss rates and higher delay than CoAP messages at higher loss rates. Moreover, when the message size is small and the loss rate is equal to or less than 25%, CoAP generates lower additional traffic than MQTT to ensure message reliability.

Mobility-on-demand (MoD) systems have recently emerged as a promising paradigm of one-way vehicle sharing for sustainable personal urban mobility in densely populated cities. In this paper, we enhance the capability of a MoD system by deploying robotic shared vehicles that can autonomously cruise the streets to be hailed by users. A key challenge to managing the MoD system effectively is that of real-time, fine-grained mobility demand sensing and prediction. This paper presents a novel decentralized data fusion and active sensing algorithm for real-time, fine-grained mobility demand sensing and prediction with a fleet of autonomous robotic vehicles in a MoD system. Our Gaussian process (GP)-based decentralized data fusion algorithm can achieve a fine balance between predictive power and time efficiency. We theoretically guarantee its predictive performance to be equivalent to that of a sophisticated centralized sparse approximation for the GP model: The computation of such a sparse approximate GP model can thus be distributed among the MoD vehicles, hence achieving efficient and scalable demand prediction. Though our decentralized active sensing strategy is devised to gather the most informative demand data for demand prediction, it can achieve a dual effect of fleet rebalancing to service the mobility demands. Empirical evaluation on real-world mobility demand data shows that our proposed algorithm can achieve a better balance between predictive accuracy and time efficiency than state-of-the-art algorithms., Robotics: Science and Systems (RSS 2013), Extended version with proofs, 10 pages

Background A recent study by the International Study of Asthma and Allergies in Childhood has shown that asthma symptom prevalence is still increasing in parts of Asia. As such, it is important to know how well asthma is being managed. Practices of physicians in India, China, Sri Lanka, Australia, Singapore, Indonesia, Philippines, and Taiwan in monitoring and treating childhood asthma were examined. Methods A 6-page standardized questionnaire was sent to physicians via post. The questionnaire is made up of 3 parts, including (1) methods of monitoring of childhood asthma, (2) practices in managing acute asthma exacerbations, and (3) choice of therapy in maintenance treatment. Results Our study reflects mostly the practices of physicians who practice in urban regions. Of respondents, 41.4% were general pediatricians, whereas 26.3% were general practitioners. A small fraction of physicians used score cards or diaries to monitor asthma, ranging from 0% (Philippines and Australia) to 15.9% (India). Only 8.1% (Sri Lanka) to 52.0% (Australia) use either a peak flow meter and/or spirometry to monitor asthma. However, for frequency of use, 35% (China) to 94% (Indonesia) never or seldom make use of a peak flow meter, and 33% (China) to 97.6% (Indonesia) never or seldom use spirometry for monitoring. Most physicians treat acute asthma appropriately with short-acting bronchodilators. For maintenance treatment, an inhaled corticosteroid was the most frequently chosen first-choice therapy. However, a significant fraction of physicians chose a long-acting β-agonist monotherapy as a first-choice treatment for asthma maintenance. For infants, the percentage ranged from 1.4% (Australia) to 76.3% (Indonesia); in preschoolers, 1.8% (Australia) to 43.3% (Indonesia); and in older children, 0% (Philippines) to 28.8% (Indonesia). These results may be related to the overall affluence of each nation. Conclusions There is much room for improvement in increasing physicians' awareness to guidelines for more effective management of pediatric asthma in Southeast Asia, especially regarding the high use of long-acting β-agonist monotherapy, even in young children.

Mobile data relay agents (or ferries) have the potential to build wireless backbones over which sparsely located, unconnected nodes can communicate in a delay-tolerant fashion. Paths taken by agents determine the quality of such delay tolerant networks (DTNs). We consider the problem of determining agent paths that minimize the maximum pair wise latency in the network. We introduce the concept of Bounded Edge-Count Diametric Latency Minimizing Steiner trees (BECDLMST) where each edge represents an agent path and non-leaf nodes represent rendezvous points. Using ideas from particle swarm optimization, we propose an anytime algorithm to generate a near optimal BECDLMST. Beginning with a simple Minimum Diameter Steiner Tree (MDST), we apply an anytime heuristic and iteratively evolve the tree to produce a network structure that minimizes the maximum latency. Network latency results are presented for varying problem sizes in terms of number of nodes and number of agents.

This paper presents a formation flight controller for lightweight UAVs when flying in windy scenarios under realistic communication limitations. The susceptibility of light aircrafts to even moderate winds necessitates a controller that corrects for its effects. On the other hand, the lightness causes the wingtip vortices, which form an important concern for most works in this area, to be negligible. The parameters used in order to track the separation trajectory are cross track error, XTD, and along track distance, ATD. The lateral controller has a modified Dynamic Cell Structure for the outer loop control and a Non Linear Dynamic Inversion (NLDI) controller for the inner loop control. The aim of the lateral controller is to generate accurate aileron deflections such that precisely sufficient roll is produced to keep the follower UAV on track by maintaining XTD at zero. The longitudinal controller consists of a Proportional Integral Derivative (PID) controller that controls throttle based on desired ground speed. Desired ground speed is computed using ATD and timing information obtained from the leader. Communication mechanisms have been proposed that will enable the controller to work well, despite packet latencies and possible link errors. Simulations are carried out by integrating two simulators: X-Plane 8.64 and Qualnet 4.5. Two separate X-Plane simulators (follower and leader) are interfaced via Qualnet, which simulates realistic wireless link characteristics. Results show that the proposed controller is capable of maintaining the follower within 10ft of the desired position at any point in time even with winds blowing at 30kts. The communication mechanism ensures good performance by the controller even with a 50% packet loss ratio, beyond which the probability of having more than 3 consecutive packet drops becomes high.

This paper presents an approach to failure detection in civil structure using supervised learning of data under normal conditions. For supervised learning to work, we would typically need data of anomalous cases and normal conditions. However, in reality there is abundant of data under normal conditions, and little or none anomalous data. Anomalous data can be generated from simulation using finite element modeling (FEM). However, every structure needs a specific FEM, and simulation may not cover all damage scenarios. Thus, we propose supervised learning of normal strain data using artificial neural networks and make prediction of the strain at future time instances. Large prediction error indicates anomalies in the structure. We also explore learning of both temporal trends and relationship of nearby sensors. Most literature in anomalies detection makes use of either temporal information or relationship between sensors, and we show that it is advantageous to use both.

This paper proposes the use of low-cost unmanned aerial vehicles (UAVs) to enable communication between mutually unreachable ground stations in regions without communication infrastructure. The proposed method involves flying UAVs at communicable altitude in a pre-specified pattern over the ground stations. A fully autonomous control system based on the proportional integral derivative controller and the non-linear dynamic inversion controller has been built for this purpose. A modified Ad-hoc On-Demand Distance Vector (AODV) protocol is used to route data packets between the ground stations over the network formed by the UAVs using a delay tolerant approach. Using simulations, we show the effectiveness of the proposed solution, which consistently achieves a packet delivery ratio of above 90% regardless of number of UAVs. The average end-to-end delay drops steeply with an increase in number of UAVs. For a separation distance of 2 km between ground stations, four low-cost UAVs with commodity WiFi communications equipment can achieve an average end-to-end delay of 15 s and packet delivery ratio of 95%, thus giving a good balance between number of UAVs and average end-to-end delay.

This paper presents a Dynamic Cell Structure (DCS) based flight control system capable of enhancing lateral stability of aircrafts during severe crosswind landings. Two hybrid control systems are proposed. The first control system involves a Proportional Integral Derivative (PID) component and a modified DCS while the second control system involves a Non-linear Dynamic Inversion (NDI) component and a modified DCS. Three important changes have been made to the original DCS learning algorithm to increase the speed and accuracy of offline learning on the DCS. The classic gain controller within the NDI block is replaced with a PID component. Readings from the localizer of an aircraft are used to form a 2-dimensional input space and supplied to the control system in order to generate appropriate control surface deflections. The aim of the control system is to generate accurate control surface deflections such that precisely sufficient roll is produced to keep the aircraft along runway centerline (as required by the maneuver of crab landing). Simulations are carried out using a Piper PA-46 Malibu on the X-Plane simulator with the proposed control systems, and compared against the performance of the lateral stability component of a baseline PID system, dual-PID control system as well as that of a PID-NDI control system. Both the DCS-based hybrid control systems have shown tremendous improvement over the baseline PID system. Of all the systems compared, the DCS-NDI hybrid provides the best performance in terms of convergence time and average deflection from runway centerline. However, the computational complexity involved in the NDI block calls for a high performance system that can perform these complex computations in realtime. Considering the systems without an NDI component, the DCS-PID hybrid provides the best performance. The DCS-PID hybrid involves lesser computation as compared to the DCS-NDI hybrid, and performs better than the dual-PID control system. At high, yet realistic crosswind speeds of 50kts, both the proposed hybrid control systems are capable of converging to and maintaining runway centerline whereas the baseline PID system fails.

A pervasive computing environment consists typically of a large heterogeneous collection of networked devices which can acquire and reason on context information. Embedded devices are used extensively in pervasive environments but they face some key challenges. Common path searching algorithms like A* Search can have exponential number of node expansions. In this paper, we describe a special variant of this problem called Multiple Objective Path Search (MOPS) and propose a memory bounded solution to implement it in a pervasive environment. Experimental results show that an efficient path with 40-60 times less node expansions can be obtained with the proposed solution.