An approximation delay between consecutive requests for congestion control in unicast CoAP-based group communication

This research presents a way to avoid network congestion during unicast CoAP-based group communication using increased delays between consecutive requests (DCR) in LoWPAN border routers to limit request send rates. It also provides a way to determine DCR values that are suitable for various network group sizes with differing node counts. The optimal DCR is obtained using the least squares approximation method and the relative minimum. Results from experimentation shows a positive relation, that is, an increase in group size necessitates an increase in DCR value. Experiments in various group sizes show favorable network performance and support the proposed congestion control method using DCR

Detection of odor perception in Asiatic honeybee (Apis cerana Fabricius, 1793) workers by changing membrane potential of the antennal sensilla

The role of honeybee mandibular gland compounds is poorly understood, although they may act as alarm pheromones. We measured forager and guard bee antennal responses evoked by two major components of mandibular gland secretions of the Asiatic honeybee, Apis cerana. Membrane potentials of antennal sensilla were measured after exposure to three concentrations of the synthetic alarm pheromones 2-heptanone and (Z)-11-eicosen-1-ol using a potentiostat (EA161) connected to an e-corder (ED401) with microelectrodes. The resting membrane potential of A. cerana foragers and guards was -55.23 ± 1.44 and -56.41 ± 1.21. mV, respectively. The membrane potential of foragers after exposure to 1.0, 5.0 and 10.0 2-heptanone was -5.32 ± 0.46, -8.41 ± 1.33 and -11.53 ± 2.16. mV, respectively. The membrane potential of guards was -5.49 ± 1.66, -8.46 ± 1.32 and -7.31 ± 3.46. mV, respectively. Exposure of foragers to 1.0, 5.0 and 10.0 (Z)-11-eicosen-1-ol induced membrane potentials of -24.00 ± 6.56, -36.36 ± 5.18 and -14.60 ± 8.20. mV, respectively; for guards they were -47.62 ± 1.46, -46.08 ± 0.87 and -9.35 ± 1.96. mV, respectively. The highest membrane potential was found in foragers exposed to 1.0 2-heptanone. The membrane potentials of foragers were higher than that of guards except at the highest concentration (10.0) of both pheromones. These findings suggest that antennal sensory receptors of foragers may have higher specific thresholds than those of guards. © 2010 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society

Factors Relating to Acceptance of Hepatitis B Virus Vaccination by Nursing Students in a Tertiary Hospital, Pakistan

This cross-sectional study aimed at assessing the prevalence of, and factors relating to, the acceptance of hepatitis B virus (HBV) vaccination by nursing students in a tertiary hospital in Pakistan. In total, 210 nursing students of Year 2 to Year 4 were invited to participate in the study; of them, 196 (93.3%) returned completed questionnaires. Overall, the prevalence of acceptance of HBV vaccination among them was 75.0%. Of these, 37.2% (73/196) were completely vaccinated, and 25.0% (49/196) had not been vaccinated at all. More than half (27/49, 55.1%) of the unvaccinated nursing students stated that they would accept vaccination if offered. Multiple logistic regression analysis indicated three variables significantly related to acceptance of HBV vaccination: history of accidental exposure to blood or blood products, acceptable knowledge about HBV infection, and adequate budget for HBV vaccination. Health institutions should allocate adequate budgets to vaccinate their nursing students. Effective intervention programmes designed to increase knowledge about HBV infection and adhering to universally-accepted precautions are needed

Performance Evaluation of Triangular Number Sequence Backoff Algorithm for Constrained Application Protocol

In the of the Internet of Things (IoT) realm, congestion is considered a serious issue affecting network throughput due to the requirement of multiple nodes for message exchange. With free-space optical communications, which can help send a message wirelessly, congestion control mechanisms nowadays depend upon the carrier sense of multiple access with collision avoidance (CSMA/CA), using the so-called Backoff Algorithm (BA).  These algorithms, including Binary Exponential Backoff (BEB), Enhanced Fibonacci Backoff (EFB), Estimation-Based Backoff (EBA), and Backoff Interval Isolation (BII), have been introduced to facilitate congestion control mechanisms. Implementing such algorithms, however, might not deliver the greatest performance for Constrained Application Protocol (CoAP) which typically operates under limited resources. Therefore, the present study aims to introduce a new backoff algorithm, Triangular Number Sequence Backoff (TNSB), and to compare its performance with that of the aforementioned algorithms under the Transmission Control Protocol (TCP) and the Cooja network simulator. Statistical analysis involves ANOVA (F-test) and post hoc multiple comparison tests. The study shows that its performance is not significantly different from the others at the low congestion level. At the middle and the high congestion levels, it yields the highest throughput with the shortest settling time, while the packet loss rate and the response time are satisfactory

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

Quality of Sleep and Associating Factors among the Elderly with Urinary Incontinence

Objective: This study aimed to assess the prevalence of poor quality of sleep, and its associating factors among Thai elderly with urinary incontinence (UI), in Chiang Rai province.  Material and Methods: Study samples from 419 individuals with UI, aged ≥60 years and living in Chiang Rai province were taken. Multi-stage random sampling was used to recruit study participants. Thai versions of the International Consultation on Incontinence Questionnaire-Short Form (TICIQ-UI SF) and the Pittsburg Sleep Quality Index (TPSQI) were used as data collection instruments.  Results: Overall, 84.2% of participants had poor quality of sleep (TPSQI >5); with the mean TPSQI score being 8.4±3.16. Approximately 21.5%, 69.2%, and 9.3% had severe, moderate, and mild UI, respectively. Multiple logistic regression analysis revealed that being female (OR=2.77; 95% confidence interval (CI), 1.47-5.24); having a moderate severity of UI (OR=3.63; 95% CI, 1.10-11.96); being a current smoker (OR=6.84; 95% CI, 2.09-22.33); monthly income of <5,000 Baht (<167 USD) (OR=4.27; 95% CI, 1.33-13.73); being a current alcohol consumer (OR=3.04; 95% CI, 1.47-6.28) and being depressed (OR=3.91; 95% CI, 1.44-10.56) were significantly associated with poor quality of sleep.  Conclusion: The prevalence of poor quality of sleep among the elderly with UI was rather high. The combined effects of several risk factors caused the elderly with moderate UI to have a poor quality of sleep. Healthcare personnel should regularly conduct screening for quality of sleep, UI, and depression and provide sleep health education to the elderly with UI, especially the elderly with depression, smokers, and alcohol consumers

Factors Relating to Acceptance of Hepatitis B Virus Vaccination by Nursing Students in a Tertiary Hospital, Pakistan

This cross-sectional study aimed at assessing the prevalence of, and factors relating to, the acceptance of hepatitis B virus (HBV) vaccination by nursing students in a tertiary hospital in Pakistan. In total, 210 nursing students of Year 2 to Year 4 were invited to participate in the study; of them, 196 (93.3%) returned completed questionnaires. Overall, the prevalence of acceptance of HBV vaccination among them was 75.0%. Of these, 37.2% (73/196) were completely vaccinated, and 25.0% (49/196) had not been vaccinated at all. More than half (27/49, 55.1%) of the unvaccinated nursing students stated that they would accept vaccination if offered. Multiple logistic regression analysis indicated three variables significantly related to acceptance of HBV vaccination: history of accidental exposure to blood or blood products, acceptable knowledge about HBV infection, and adequate budget for HBV vaccination. Health institutions should allocate adequate budgets to vaccinate their nursing students. Effective intervention programmes designed to increase knowledge about HBV infection and adhering to universally-accepted precautions are needed