Experimental demonstration of flexible information rate PON beyond 100 Gb/s with rate-compatible LDPC codes.

The applications of rate-compatible low-density parity-check (RC-LDPC) codes are investigated for a 16 quadrature amplitude modulation (16QAM) signal and coherent detection system. With rate-compatible signals, we can provide the flexible net data rate between 135.5 Gb/s and 169.7 Gb/s in a passive optical network (PON) link. Based on the LDPC codes defined in the IEEE 802.3ca standard, we construct two sets of RC-LDPC codes with a fixed and variable information bit length. Since the puncturing operation may degrade the performance of LDPC codes, we apply the protograph-based extrinsic information transfer (PEXIT) technique to optimize the puncturing positions to mitigate the degradation. Additionally, we explore four low-complexity LDPC decoding algorithms (min sum, offset min sum, variable weight min sum, and relaxed min sum with 2nd min emulation) to investigate the relationship between the computational complexity and decoding performance. Simulation results indicate that the constructed codewords exhibit good performance in the waterfall region across a range of code rates. Finally, we conduct an experimental setup in a dual-polarization 25 GBaud 16QAM coherent PON to verify the effectiveness of the constructed LDPC codes with four decoding algorithms. The experimental results show maximal 4.8 dB receiver sensitivity differences, which demonstrate the feasibility of the method for constructing RC-LDPC codes in future high-speed flexible coherent PON.

Estimating staffing requirements using workload indicators of staffing need at Braun District Hospital in Morobe Province, Papua New Guinea.

BACKGROUND: Papua New Guinea has seen some improvements in health indicators over the past years, but the pace of improvements is not as robust as expected. The Health Services Plan for Braun District Hospital redevelopment identified the importance of reflecting the hospital's role in the broader health system, particularly in upgrading the services to service a bigger population. In August 2020, the hospital was upgraded from a health centre-level 3 to a district hospital level 4. The need for assessing human resources for health requirements for this level of care was thus necessary. METHODS: The National Department of Health approved the use of the workload indicators of staffing need as the best tool to support in estimating staff requirements for the newly upgraded hospital. The focus was on clinical and non-clinical staff. Using already developed workload components and activity standards by the expert working groups for level 4 facilities, we visited the facility and collected data through interviews with the Lutheran Health Services representative, hospital management and staff. The technical task force reviewed daily registers, monthly reports and the data in the electronic national health information systems. The information collected was analysed using the workload indicators of staffing need software and interpreted. RESULTS: There were staffing shortages among the clinical staff like the medical officers, nursing officers, health extension officers, pharmacists, radiology staff unit and in the laboratory staff. Shortages among the non-clinical staff were recorded by the cashiers, security officers, drivers and boat skippers. The results showed that the facility lacks a medical laboratory technologist, pharmacists and a medical imaging technologist. The community health workers in this facility are utilized in all the areas where shortages are registered to multitask. CONCLUSION: The results from this WISN study provide evidence for basing staffing decisions on. The WISN results from Braun District Hospital show that the facility requires a total of 33 inpatient nurses against the existing 21 inpatient nurses thus giving a staff gap of - 12 and a WISN ratio of 0.67. It is thus recommended that the hospital management prioritizes recruitment of nurses or if no resources, reassign one of the outpatient nurses to alleviate the pressure among the inpatient nurses or the extra theatre nurses to offer some services in the inpatient wards. WISN results can help managers make decisions such as change of health facility status from a health centre to a district hospital.

Single-axis soliton molecule and multiple solitons generation from a vector fiber laser.

We investigate various patterns of vector solitons arising in a passively mode-locked fiber laser based on semiconductor saturable absorber mirror (SESAM). By properly adjusting the cavity parameters including the pump power and intra-cavity birefringence, the fundamental vector solitons, vector soliton molecules, and macroscopic vector solitons can be separately observed. In particular, both vector soliton molecule and macroscopic vector solitons exhibit multi-pulse structure along one polarization axis while there occurs single pulse profile at its orthogonal polarization component. Thus, they can be treated as "1 + 2" and "1+n" vector solitons. Moreover, the size of the macroscopic solitons can be manipulated from half of the cavity to even the whole cavity. The generation mechanisms of these vector soliton patterns are also investigated.

High-Sensitivity Goos-Hänchen Shifts Sensor Based on BlueP-TMDCs-Graphene Heterostructure.

Surface plasmon resonance (SPR) with two-dimensional (2D) materials is proposed to enhance the sensitivity of sensors. A novel Goos-Hänchen (GH) shift sensing scheme based on blue phosphorene (BlueP)/transition metal dichalogenides (TMDCs) and graphene structure is proposed. The significantly enhanced GH shift is obtained by optimizing the layers of BlueP/TMDCs and graphene. The maximum GH shift of the hybrid structure of Ag-Indium tin oxide (ITO)-BlueP/WS2-graphene is -2361λ with BlueP/WS2 four layers and a graphene monolayer. Furthermore, the GH shift can be positive or negative depending on the layer number of BlueP/TMDCs and graphene. For sensing performance, the highest sensitivity of 2.767 × 107λ/RIU is realized, which is 5152.7 times higher than the traditional Ag-SPR structure, 2470.5 times of Ag-ITO, 2159.2 times of Ag-ITO-BlueP/WS2, and 688.9 times of Ag-ITO-graphene. Therefore, such configuration with GH shift can be used in various chemical, biomedical and optical sensing fields.

Aquatic debris detection using embedded camera sensors.

Aquatic debris monitoring is of great importance to human health, aquatic habitats and water transport. In this paper, we first introduce the prototype of an aquatic sensor node equipped with an embedded camera sensor. Based on this sensing platform, we propose a fast and accurate debris detection algorithm. Our method is specifically designed based on compressive sensing theory to give full consideration to the unique challenges in aquatic environments, such as waves, swaying reflections, and tight energy budget. To upload debris images, we use an efficient sparse recovery algorithm in which only a few linear measurements need to be transmitted for image reconstruction. Besides, we implement the host software and test the debris detection algorithm on realistically deployed aquatic sensor nodes. The experimental results demonstrate that our approach is reliable and feasible for debris detection using camera sensors in aquatic environments.

Use of a catch-up programme to improve routine immunization in 13 provinces of Papua New Guinea, 2020-2022.

Objective: Routine immunization coverage in Papua New Guinea has decreased in the past 5 years. This persistently low routine immunization coverage has resulted in low population immunity and frequent outbreaks of vaccine-preventable disease across the country. We describe the use of a catch-up programme to improve routine immunization during the coronavirus disease pandemic in Papua New Guinea during 2020-2022. Methods: In June 2020, 13 provinces of Papua New Guinea were selected to undergo a vaccination catch-up programme, with technical support from the World Health Organization (WHO) and the United Nations Children's Fund. Twelve provinces received financial and logistic support through the Accelerated Immunization and Health Systems Strengthening programme, and one received support from WHO. All stakeholders were involved in planning and implementing the catch-up programme. Results: Between July 2020 and June 2022, about 340 health facilities conducted catch-up activities. The highest number of children aged under 1 year were vaccinated in 2022 (n = 33 652 for third dose of pentavalent vaccine). The national coverage of routine immunization (including the catch-up vaccinations) increased between 2019 and 2020 - by 5% for the third dose of pentavalent vaccine, 11% for the measles-rubella vaccine and 16% for the inactivated poliovirus vaccine. The coverage declined slightly in 2021 before increasing again in 2022. Discussion: The catch-up programme was an instrumental tool to improve routine immunization coverage between 2020 and 2022 and during the pandemic in Papua New Guinea. With appropriate technical and logistic support, including financial and human resources, catch-up programmes can strengthen routine immunization coverage across the country.

Evaluation on production trend, compositions, and impact of plastic waste in Chengdu, southwestern China.

Based on statistical data from 2005 to 2019, we used the back propagation (BP) neural network model to predict the production amount of plastic waste in Chengdu. In addition to the amount of waste produced we wanted to achieve an understanding of its composition and environmental impacts. Compositions of plastic waste were analyzed by sampling. Particulate matter in the air and greenhouse gas emissions (GHGs) from plastic waste incineration, bisphenol A (BPA) from plastic waste landfills, were also evaluated. Results indicated that (a) economic development, urban construction level, and residents' consumption were pusitively correlated to different degrees to plastic waste production; (b) the production of plastic waste in Chengdu in 2025 and 2030 will reach 865.3 and 931 kilotons (Kt), respectively; (c) high density polyethylene (HDPE) and polypropylene (PP) are the two main components of plastic waste in Chengdu and accounted for 40.17% and 24.96%, respectively; (d) different degrees of environmental impacts occurred during plastic waste incineration and landfill (taking 2019 as an example, the incineration of plastic waste in Chengdu produced between 2874.82 and 4711.73 tons of inhalable particulate matter (PM) and emitted between 725.4 and 867.4 Kt of CO2, and between 65.02 and 910.27 kg of bisphenol A (BPA) leached from sanitary landfills); (e) positive policies and measures from the beginning to the end-of-life of plastics should be carried out in the future, which would improve the level of plastic waste management in Chengdu and mitigate the side-impacts from plastic waste treatment and disposal.Implications: The implications of this article are Generation trends of plastic waste were revealed by a BP neural network model, which provided essential data for authorities to make decisions on waste management.Influencing factors affecting plastic waste generation were analyzed, which will strongly support policy considerations regarding plastic waste control.This investigation first explored and reported the compositions of plastic waste mixed with municipal solid waste (MSW), which yielded valuable information concerning plastic waste and details concerning the impacts of plastic waste disposal processes.Those results of this investigation, being published here for the first time, will guide plastic waste management in Chengdu and could also provide useful information to other cities regarding that issue.

Hidden varicella outbreak, Luang Prabang Province, the Lao People's Democratic Republic, December 2014 to January 2015.

BACKGROUND: In January 2015, the Lao People's Democratic Republic Ministry of Health received a report of 34 cases of fever and rash with one laboratory-confirmed measles case in Houitone village, Pakseng District of Luang Prabang Province. Between 21 and 27 January, we conducted a field investigation to determine the etiology, magnitude and severity of this outbreak. METHODS: We conducted active case findings in Houitone and neighbouring villages and collected information on age, location, date of rash onset, symptoms and measles vaccination status. We collected serum samples from cases with rash onset of less than 28 days and tested for measles and rubella IgM using enzyme-linked immunosorbent assay. RESULTS: Between 22 December 2014 and 23 January 2015, 190 fever and rash cases were identified in seven villages in Pakseng District with the majority of the cases in Houitone village. The most affected age group was between 1 and 9 years. The majority of the rashes were vesicular. Of the additional 43 serum samples collected, no samples tested positive for measles or rubella IgM. The clinical manifestation and epidemiology of the disease suggested a varicella outbreak. CONCLUSION: The rapid response to a single laboratory-confirmed measles case did not identify a measles outbreak but suggested a varicella outbreak. Low measles vaccination coverage led us to recommend a routine catch-up vaccination campaign. We also recommend collecting information of rash types and photos of rashes in future fever and rash outbreaks to better differentiate potential etiologies.

Trends in the incidence of acute watery diarrhoea in the Lao People's Democratic Republic, 2009-2013.

Diarrhoeal disease is the second leading cause of death in children under age 5 worldwide, with rotavirus being the main etiology. In the Lao People's Democratic Republic, acute watery diarrhoea (AWD) was introduced as one of the national notifiable diseases in 2004. We retrospectively reviewed the aggregate (n = 117 277) and case-based (n = 67 755) AWD surveillance data from 2009 to 2013 reported weekly from 1115 health facilities nationwide. Rotavirus rapid test data from all eight sentinel sites in Vientiane Capital in 2013 were also collected for analysis. The incidence of AWD ranged between 215 and 476 cases per 100 000 population and increased from 2009 to 2012 when it levelled off. The most affected age group was children under 5 who were about seven to nine times more likely to have AWD than the rest of the population (P < 0.0001). In children under 5, 74.8% of the cases were aged 0-24 months and AWD was 1.28 times more common in males (P < 0.0001). Among the 230 stool specimens tested in children under 5 in 2013, 109 (47.4%) tested positive for rotavirus. The increased AWD incidence over the study period may reflect a true increase in AWD or an improved sensitivity of the system. We recommend new mothers breastfeed up to two years after birth, which is known to reduce AWD morbidity and mortality in young children. We also recommend conducting rotavirus disease burden and cost-effectiveness studies to explore the benefits of introduction of rotavirus vaccine.

Glucose oxidase adsorption performance of carbonaceous mesocellular foams prepared with different carbon sources.

Several carbonaceous mesocellular foams (C-MCFs) were prepared with MCF-silica as template using the carbon precursors of sucrose, furfuryl alcohol and lab-made phenolic resin, and the corresponding C-MCFs were named as C-MCF-Suc, C-MCF-FA and C-MCF-PR, respectively. The results of SEM, transmission electron microscopy, N2 adsorption-desorption and energy-dispersive X-ray measurements indicated that the C-MCFs prepared from different carbon source appeared morphologically with different degree of order and different pore distribution. The C-MCF-FA exhibited the highest ordered structure and the smallest pore distribution among the foams. The optimum conditions for adsorption of C-MCFs on glucose oxidase (GOD) were also studied, and the maximum adsorbance was determined. The adsorption of GOD on C-MCF-FA was performed at different pH with different GOD concentrations. The maximum adsorption (423.3 mg g(-1)) was observed near the isoelectric point of the GOD (pI ≈ 5.0) with a GOD concentration of 6.0 mg mL(-1), suggesting that the GOD adsorption on C-MCFs might be affected strongly by the electric repulsion between the GOD molecules. Moreover, GOD adsorption performances on different C-MCFs revealed that both the pore size and the pore volume played important roles in the adsorption process, and the window size of C-MCFs dominated the residual immobilized amounts of GOD. Compared to the other two C-MCFs, the C-MCF-FA with a smaller window pore (10 nm) and higher volume (1.40 cm(3) g(-1)) exhibited the highest GOD adsorption and catalytic activity. Furthermore, the immobilized GOD exhibited improved thermal and storable stabilities. Thus the C-MCF-FA could be served as the prospective GOD carrier material used in enzymatic fuel cells.

Two-dimensional supramolecular spring: coordination driven reversible extension and contraction of bridged half rings.

A tetraethylene glycol ether bridged derivative 9 has been designed and synthesized, and its two-dimensional (2D) self-assembled behavior has been investigated at the single-molecule level. Our results revealed that 9 generally adopted the fully extended state but changed to the contracted state when triggered by K2CO3, and recovered the original fully extended conformation after subsequent addition of 18-crown-6. Such a coordination-controlled reversible assembly reveals supramolecular springs in response to chemical stimuli, which is of great interest in bionics and materials science.

Investigation of a mumps outbreak in Mongolia, January to April 2011.

INTRODUCTION: The Gurvantes district in Omnogovi Province reported a suspected mumps outbreak to the Mongolia Ministry of Health in March 2011. An outbreak investigation team was established to verify the diagnosis and to determine the magnitude of the outbreak. METHODS: The descriptive study comprised retrospective investigation of local hospital medical records and surveillance data, and interviews with school teachers, doctors, probable cases and their close contacts. The World Health Organization standard case definition was used to define mumps cases. Clinical specimens were collected for laboratory confirmation. RESULTS: There were 153 cases, none under two years of age, with the five- to 14-years-old age group having the highest rates. There was no difference by sex (P = 0.12). A single index case appeared to be the source of the outbreak, and there were four outbreak waves. Of the 129 cases with information on epidemiological links, 94 (72.3%) were linked to other cases at a kindergarten or school, 17 (13%) were from secondary spread of family members, two (1.5%) were from secondary spread of other relatives, and 16 had no established links. Eight cases (5.2%) were confirmed through laboratory investigation. CONCLUSION: This was the first high-magnitude mumps outbreak since the introduction of the measles-mumps-rubella vaccine in Mongolia in September 2009. There were no cases among vaccinated children; cases were seen among older children and adults not eligible for the vaccine. This suggests that immunity to mumps is still low in Mongolia. Future outbreaks may occur among this unvaccinated population.