Reaction of aqueous catechol solutions with minerals

The effectiveness of catechol, an aromatic vic-diol, in dissolving silicate minerals was studied. A synthetic amorphous magnesium trisilicate, Mg₂Si₃O₈∙5H₂O, as well as the minerals olivine, sepiolite, diopside, augite, and enstatite were used to react with catechol in slightly acidic, basic, and neutral solutions. It was found, depending on the solvent used, that 33-52, 8-17, 14-30, 5-11, 3-6, and 0.5-1 % of the minerals dissolved, respectively. The reaction with Mg₂Si₃0₈·5H₂0 resulted in the formation of crystals of magnesium tris (catecholato) siliconate nonahydrate Mg[Si(Cat)₃]∙9H₂0. Dehydration of the crystals at room temperature resulted in the loss of 6 moles of water to form a trihydrated complex, Mg[Si(Cat)₃]·3H₂0; further dehydration at 100°C gave an anhydrous complex, Mg[Si(Cat)₃]. By adding guanidine hydrochloride, CN₃H₆Cl, to the reaction mixture after filtering, crystals of guanidinium tris (catecholato) siliconate monohydrate, (CN₃H₆)₂[Si(Cat)₃]∙H₂0, were obtained. Infrared and nmr spectra, and analytical and x-ray powder diffraction data are presented. The possible structures of the magnesium salts of tris (catecholato) siliconate are also discussed. The reaction of catechol with the minerals listed above gave a water soluble silicon-catechol complex, Si (Cat)₃⁼, which was isolated as (CN₃H₆)₂[Si(Cat)₃]·H₂0 by adding guanidine hydrochloride to the reaction mixture after filtering. The dissolution of these minerals by catechol to form Si(Cat)₃⁼ leads to the conclusion that aromatic vic-diols in nature may play a role in chemical weathering, in transport of silicon into rivers or seas, in soil development, in interconversion of minerals, and in accumulation of silica in plants

Partial network coding with cooperation : a study over multi-hop communications in wireless networks

The imperfections of the propagation channel due to channel fading and the self-generated noise from the RF front-end of the receiver cause errors in the received signal in electronic communication systems. When network coding is applied, more errors occur because of error propagation due to the inexact decoding process. In this dissertation we present a system called Partial Network Coding with Cooperation (PNC-COOP) for wireless ad hoc networks. It is a system which combines opportunistic network coding with decode-and-forward cooperative diversity, in order to reduce this error propagation by trading off some transmission degrees of freedom. PNC-COOP is a decentralized, energy efficient strategy which provides a substantial benefit over opportunistic network coding when transmission power is a concern. The proposed scheme is compared with both opportunistic network coding and conventional multi-hop transmission analytically and through simulation. Using a 3-hop communication scenario, in a 16-node wireless ad hoc network, it is shown that PNC-COOP improves the BER performance by 5 dB compared to opportunistic network coding. On average, it reduces the energy used by each sender node around 10% and reduces the overall transmitted energy of the network by 3.5%. When retransmission is applied, it is shown analytically that PNC-COOP performs well at relatively low to medium SNR while the throughput is comparable to that of opportunistic network coding. The effectiveness of both opportunistic network coding and PNC-COOP depends not only on the amount of network coding but also on other factors that are analyzed and discussed in this dissertation.Keywords: opportunistic network coding, Telecommunications, cooperative diversity, network coding, user cooperatio

LDPC-VBLAST for wireless communications

Recently, the demand for higher data rates of transmission has increased in many wireless communication applications. Using multi-transmit and multi-receive antennas has been shown to be a solution, since it can increase the channel capacity to accommodate higher transmission rates. Among the popular techniques developed to exploit the use of multiple antennas, VBLAST (Vertical Bell Laboratories Layered Space-Time) architecture can provide a very high spectral efficiency. However, in order to have better performance, an efficient error correction coding scheme with low complexity to implement is needed. In this study, we applied the Low density parity-check (LDPC) codes to the multi-transmit and multi receive antennas system, by combining Euclidean geometry LDPC codes with VBLAST system. Different code rates and different numbers of antennas are evaluated. By Monte-Carlo simulation, it is shown that the combination of both LDPC-VBLAST improves the bit error rate performance of the conventional one. Higher code rates improve further bit error rate performance while maintaining a high transmission data rate. LDPC-VBLAST can achieve nearly the lower bound performance of LDPC coding used with the multiple antennas optimum detector, maximum likelihood (ML) detector, when increasing the number of receive antennas. However, unlike ML detector, LDPC-VBLAST has lower complexity than ML detector when increasing the number of antennas. Thus, LDPC VBLAST can be suitable for using in many wireless applications

On a Different Perspective and Approach to Implement Adaptive Normalized BP-based Decoding for LDPC Codes

In this paper, we propose an improved version of the min-sum algorithm for low density parity check (LDPC) code decoding, which we call “adaptive normalized BP-based” algorithm. Our decoder provides a compromise solution between the belief propagation and the min-sum algorithms by adding an exponent offset to each variable node’s intrinsic information in the check node update equation. The extrinsic information from the min-sum decoder is then adjusted by applying a negative power of two scale factor, which can be easily implemented by right shifting the min-sum extrinsic information. The difference between our approach and other adaptive normalized min-sum decoders is that we select the normalization scale factor using a clear analytical approach based on underlying principles. Simulation results show that the proposed decoder outperforms the min-sum decoder and performs very close to the BP decoder, but with lower complexity.Keywords: modified min-sum, belief propagation, sum product, min-sum, LDPC codes, iterative decodin

Management Capabilities and Policy Capacity Where are the Links?

1-1

International Comparative Analysis of COVID-19 Responses

Chapter 01. Introduction Chapter 02. The Evolution of COVID-19 and Policy Responses of Korea: Adaptation and Learning Perspectives Chapter 03. Japan’s Response to the COVID-19 Pandemic: A Cautious and Self-restraint-based Approach Chapter 04. Thailand’s Response to COVID-19 Chapter 05. Beyond Regime Types: Local Governance, Bureaucratic Coordination, and COVID-19 Responses in Vietnam Chapter 06. Aotearoa New Zealand’s Policy Responses to the COVID-19 Pandemic Chapter 07. COVID-19 Responses in Finland: Uneven, Fairly Effective, and Craving to Return to the Normal Chapter 08. Crisis Governance in a Multilevel System: German Public Administration Coping with the COVID-19 Pandemic Chapter 09. Sweden and the COVID-19 Crisis Chapter 10. Science, Uncertainty, and Partisanship: The United States’ Response to COVID-19 Chapter 11. Summary and Discussions for Policy Implication

Etiology of Diarrhea in Older Children, Adolescents and Adults: A Systematic Review

Diarrhea is an important cause of illness and death around the world and among people of all ages, but unfortunately we often do not know what specific bacterium or virus causes the illness. We conducted a review of the scientific literature with the goal of finding published studies that identified bacteria and viruses among patients with diarrhea in the community and in hospital settings. We initially found nearly 26,000 papers on this topic but narrowed the list to 22 studies that met all of our specific criteria for inclusion in our review. Among patients hospitalized for diarrhea, E coli and Vibrio cholerae were found in more than 49% of people living in middle income and poor countries. Among patients who sought care from their doctor on an outpatient basis, Salmonella spp., Shigella spp., and E. histolytica were most often found. In our review we focused on the differences in the distribution of pathogens between patients in inpatient vs. outpatient settings because these estimates may best approximate what we would expect to see if the distribution were applied to global estimates of diarrhea deaths vs. uncomplicated illnesses

Hot transformations: governing rapid and deep household heating transitions in China, Denmark, Finland and the United Kingdom

The rapid decarbonisation of heat remains a challenging energy and climate policy priority. In this study, after screening 461 global case studies, we examine four national household transitions in heat, and examine their implications for governance. These transitions were both rapid, involving transformations in heat provision in a short timeframe of 18 to 35 years; and deep, involving diffusion that collectively reached more than 100 million households and more than 310 million people. From 1995 to 2015, China stimulated industrial research with strong municipal and national targets and policies to the point where they saw adoption rates for solar thermal systems surpass 95% market penetration in many urban areas. From 1976 to 2011, Denmark blended small-scale decentralized community control with national standards and policies to promote district heating so it reached 80% of household needs. From 2000 to 2018, Finland harnessed user and peer-to-peer learning, and innovation, alongside national and European policies and incentives so that heat pumps reached almost a third of all homes. From 1960 to 1977, The United Kingdom coordinated a nationalized Gas Council and Area Boards with industry groups, appliance manufacturers, installers and marketing campaigns so that gas central heating reached almost half of all homes. These four rapid case studies share commonalities in polycentric governance, rooted in (1) equity, (2) inclusivity, (3) information and innovation, (4) ownership and accountability, (5) organizational multiplicity, and (6) experimentation and flexibility. The study affirms that designing the right sort of political and governance architecture can be just as salient as technical innovation and development

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030