Accuracy Verification of a Smartphone-Based PPK GNSS Surveying Technique and Earth Volume Determinations

Raw global navigation satellite system (GNSS) measurements from a smartphone are used for position determinations as they can be extracted from the Android operating systems together with Thailand Department of Lands (DOL) provide network real-time kinematic GNSS correction services; hence, enabling cheaper and more compact for high precision solutions.  This study applies the GNSS raw observations obtained from a smartphone in order to determine positions and later compute an Earth volume based on obtained positioning results as Thailand constructions are increasing in different scales and earthworks is one of the primary works.  The experimental area is 11,145 square meters with 21 ground markers.  GNSS signals are measured every 1 second at 1-hour observation period.  Computed observations from a smartphone provide relatively optimal horizontal and vertical positioning accuracies of 4 and 8 centimetres with the longest convergence time of 40 minutes.  Differences between the determined Earth volumes using the smartphone-based and traditional surveying technique do not exceed 10%.  The estimated manhour and equipment cost are efficient can lead to 90% reduction.  Performances are demonstrated and assessed on actual earthwork computations.  Future work may apply estimated smartphone-based network real-time kinematic (NRTK) and post-processed kinematic (PPK) positioning solutions as ground control points for other earthwork determinations through aerial photography

Sleep quality and associated factors among the elderly living in rural Chiang Rai, northern Thailand

OBJECTIVES This study aimed to characterize the prevalence of poor sleep quality and to identify associated factors among community-dwelling elderly individuals in northern Thailand. METHODS A cross-sectional study was conducted among 266 randomly selected elderly people in a sub-district in rural Chiang Rai Province, northern Thailand. The participants were interviewed using the Thai version of the Pittsburgh Sleep Quality Index (PSQI). RESULTS Roughly 44.0% of the participants had poor sleep quality (PSQI score, >5), 9.4% used sleep medication, 27.1% had poor family relationships, and 12.0% had mild depression. Multiple logistic regression analysis indicated that being female (odds ratio [OR], 1.74; 95% confidence interval [CI], 1.10 to 3.02), a higher education level (OR, 3.03; 95% CI, 1.34 to 6.86 for primary school; OR, 2.48; 95% CI, 1.31 to 5.44 for higher than primary school), mild depression (OR, 2.65; 95% CI, 1.11 to 6.36), and poor family relationships (OR, 3.65; 95% CI, 1.98 to 6.75) were significantly associated with poor sleep quality. CONCLUSIONS The prevalence of poor sleep quality among the elderly was moderately high. Healthcare providers should regularly conduct screenings for sleep quality and depression; provide sleep health education; and conduct interventions to encourage participating in family activities, resolving conflicts, sharing ideas, and making compromises within the family

Screening methods for obstructive sleep apnoea in severely obese pregnant women

Obstructive sleep apnoea (OSA) is an often-overlooked diagnosis, more prevalent in the obese population. Screening method accuracy, uptake and hence diagnosis is variable. There is limited data available regarding the obese pregnant population; however, many studies highlight potential risks of apnoeic episodes to mother and foetus, including hypertension, diabetes and preeclampsia. A total of 162 women with a body mass index (BMI) ≥ 35 were recruited from a tertiary referral hospital in the northwest of England. They were invited to attend three research antenatal clinics, completing an Epworth Sleepiness Scale (ESS) questionnaire at each visit. A monitor measuring the apnoea hypopnoea index (AHI) was offered at the second visit. Data taken from consent forms, hospital notes and hospital computer records were collated and anonymized prior to statistical analysis. A total of 12.1% of women had an ESS score of >10, suggesting possible OSA. Rates increased throughout pregnancy, although unfortunately, the attrition rate was high; 29.0% of women used the RUSleeping (RUS) meter, and only one (2.1%) met pre-specified criteria for OSA (AHI ≥ 15). This individual had OSA categorized as severe and underwent investigations for preeclampsia, eventually delivering by emergency caesarean section due to foetal distress. The accuracy of the ESS questionnaire, particularly the RUS monitor, to screen for OSA in the pregnant population remains unclear. Further research on a larger sample size using more user-friendly technology to confidently measure AHI would be beneficial. There are currently no guidelines regarding screening for OSA in the obese pregnant population, yet risks to both mother and foetus are well researched

Condensation heat transfer inside rotating heat pipes

An analytical study was undertaken to determine twodimensional wall conduction effects during film condensation on an internally finned, rotating heat pipe. An earlier Finite Element method was modified to solve the problem by using different numbers of axial increments and different numbers of elements. Resulting heat transfer rates were shown to be similar to those obtained earlier.http://archive.org/details/condensationheat00tantNALieutenant, Royal Thai NavyApproved for public release; distribution is unlimited

The effects of CPAP treatment on task positive and default mode networks in obstructive sleep apnea patients: an fMRI study.

INTRODUCTION: Functional magnetic resonance imaging studies enable the investigation of neural correlates underlying behavioral performance. We investigate the effect of active and sham Continuous Positive Airway Pressure (CPAP) treatment on working memory function of patients with Obstructive Sleep Apnea Syndrome (OSAS) considering Task Positive and Default Mode networks (TPN and DMN). METHODS: An experiment with 4 levels of visuospatial n-back task was used to investigate the pattern of cortical activation in 17 men with moderate or severe OSAS before and after 2 months of therapeutic (active) or sub-therapeutic (sham) CPAP treatment. RESULTS: Patients with untreated OSAS had significantly less deactivation in the temporal regions of the DMN as compared to healthy controls, but activation within TPN regions was comparatively relatively preserved. After 2 months of treatment, active and sham CPAP groups exhibited opposite trends of cerebral activation and deactivation. After treatment, the active CPAP group demonstrated an increase of cerebral activation in the TPN at all task levels and of task-related cerebral deactivation in the anterior midline and medial temporal regions of the DMN at the 3-back level, associated with a significant improvement of behavioral performance, whereas the sham CPAP group exhibited less deactivation in the temporal regions of Default Mode Network and less Task Positive Network activation associated to longer response times at the 3-back. CONCLUSION: OSAS has a significant negative impact primarily on task-related DMN deactivation, particularly in the medial temporal regions, possibly due to nocturnal hypoxemia, as well as TPN activation, particularly in the right ventral fronto-parietal network. After 2 months of active nasal CPAP treatment a positive response was noted in both TPN and DMN but without compete recovery of existing behavioral and neuronal deficits. Initiation of CPAP treatment early in the course of the disease may prevent or slow down the occurrence of irreversible impairment

Calcium and Vitamin D Supplementation for Prevention of Preeclampsia: A Systematic Review and Network Meta-Analysis

Vitamin D supplementation effects with or without calcium in pregnancy for reducing risk of preeclampsia and gestational or pregnancy induced hypertension are controversial. Literature was systematically searched in Medline, Scopus and Cochrane databases from inception to July 2017. Only randomized controlled trials (RCTs) in English were selected if they had any pair of interventions (calcium, vitamin D, both, or placebo). Systematic review with two-step network-meta-analysis was used to indirectly estimate supplementary effects. Twenty-seven RCTs with 28,000 women were eligible. A direct meta-analysis suggested that calcium, vitamin D, and calcium plus vitamin D could lower risk of preeclampsia when compared to placebo with the pooled risk ratios (RRs) of 0.54 (0.41, 0.70), 0.47 (0.24, 0.89) and 0.50 (0.32, 0.78), respectively. Results of network meta-analysis were similar with the corresponding RRs of 0.49 (0.35, 0.69), 0.43 (0.17, 1.11), and 0.57 (0.30, 1.10), respectively. None of the controls were significant. Efficacy of supplementation, which was ranked by surface under cumulative ranking probabilities, were: vitamin D (47.4%), calcium (31.6%) and calcium plus vitamin D (19.6%), respectively. Calcium supplementation may be used for prevention for preeclampsia. Vitamin D might also worked well but further large scale RCTs are warranted to confirm our findings