A Concept for Solving the Sustainability of Cities Worldwide

Considering that more than half of the world’s population today lives in cities and consumes about 80% of the world’s energy and that there is a problem with drinking water supply, this paper presents a way to solve the problem of the sustainability of cities by enabling their complete independence from external sources of energy and drinking water. The proposed solution entails the use of Seawater Steam Engine (SSE) technology to supply cities with electricity, thermal energy and drinking water. The system would involve the seasonal storage of electricity and thermal energy, supported by geothermal heat pumps. The strategy of the distribution network would be based on the original concept of the “loop”. In cities that do not have enough space, SSE collectors would be placed above the lower parts of the city like “canopies”. The city of Zagreb (Croatia) was selected as a case study due to its size, climate and vulnerability to natural disasters. The results show that Zagreb could become sustainable in 30 years with the allocation of less than 2% of GDP and could become a paradigm of sustainability for cities worldwide. This paper encourages the development of the “Philosophy of Sustainability” because the stated goals cannot be achieved without a change in consciousness.

Increasing antioxidant activity of soursop (Annona muricata L.) and noni (Morinda citrifolia L.) leaves fermented by Lactobacillus plantarum BP102

Free radicals are constantly produced by either cell metabolism or from external sources. At high concentration, they induced a tissue damage called oxidative stress. Soursop leaf (Annona muricata L.) and noni leaf (Morinda citrifolia L.) are medicinal plants with potency as antioxidants. This study aimed to evaluate the capacity of Lactobacillus plantarum BP102 in elevating the antioxidant activity of soursop and noni leaves. Dried-powder and methanol extract of soursop and noni leaves were diluted with sterile distilled water 3 g/30 mL and 0.3 g/30 mL, respectively, inoculated with 1% (v/v) of L. plantarum BP102 inoculum. The antioxidant activity was carried out using the 2.2-diphenyl-1-picrylhydrazyl (DPPH) method. The antioxidant activity increased in dried-powder and methanol extract of soursop and noni leaves with different activity levels after being fermented using L. plantarum BP102 based on IC50. The increasing antioxidant activity in dried-powder of soursop leaves IC50 6.41±0.06 to 0.034±0.01 mg/mL (99.5%) was higher than of the methanol extract IC50 2.78±0.00 to 0.11±0.01 mg/mL (96%). Unfortunately, the effect of fermentation towards noni leaves could only be observed in the form of methanol extract IC50 12.8±0.01 to 0.33±0.02 mg/mL (increased by 97.4%), the dried-powder of noni leaves was suspended and produced a dark color. The probiotic L. plantarum BP102 was used as a fermented agent in increasing the bioactive compounds especially related to antioxidant activity.

Blockchain networks as constitutional and competitive polycentric orders

Institutional economists have analyzed permissionless blockchains as a novel institutional building block for voluntary economic exchange and distributed governance, with their unique protocol features such as automated contract execution, high levels of network and process transparency, and uniquely distributed governance. But such institutional analysis needs to be complemented by polycentric analysis of how blockchains change. We characterize such change as resulting from internal sources and external sources. Internal sources include constitutional (protocol) design and collective-choice processes for updating protocols, which help coordinate network participants and users. External sources include competitive pressure from other cryptocurrency networks. By studying two leading networks, Bitcoin and Ethereum, we illustrate how conceptualizing blockchains as competing and constitutional polycentric enterprises clarifies their processes of change.

Pregnant Women’s Exposure to Household Air Pollution in Rural Bangladesh: A Feasibility Study for Poriborton: The CHANge Trial

The use of liquefied petroleum gas (LPG) for cooking is a strategy to reduce household air pollution (HAP) exposure and improve health. We conducted this feasibility study to evaluate personal exposure measurement methods to representatively assess reductions in HAP exposure. We enrolled 30 pregnant women to wear a MicroPEM for 24 h to assess their HAP exposure when cooking with a traditional stove (baseline) and with an LPG stove (intervention). The women wore the MicroPEM an average of 77% and 69% of the time during the baseline and intervention phases, respectively. Mean gravimetric PM2.5 mass and black carbon concentrations were comparable during baseline and intervention. Temporal analysis of the MicroPEM nephelometer data identified high PM2.5 concentrations in the afternoon, late evening, and overnight during the intervention phase. Likely seasonal sources present during the intervention phase were emissions from brick kiln and rice parboiling facilities, and evening kerosene lamp and mosquito coil use. Mean background adjusted PM2.5 concentrations during cooking were lower during intervention at 71 μg/m3, versus 105 μg/m3 during baseline. Representative real-time personal PM2.5 concentration measurements supplemented with ambient PM2.5 measures and surveys will be a valuable tool to disentangle external sources of PM2.5, other indoor HAP sources, and fuel-sparing behaviors when assessing the HAP reduction due to intervention with LPG stoves.

Energy planning with renewable energy sources

The urban energy model is based on imports from external sources. The continuous increase in energy demand due to population growth and development implies increasing resource requirements. The alternative is to use renewable energies that take advantage of urban resources. The diversity of typologies of cities in terms of resources, demands, architectural conditions, infrastructure, or density, makes a specific analysis necessary. This work identifies fourteen factors concerning the planning process that would allow choosing the most appropriate technology for a given city. Through consultation of experts, the existence of the resource is defined as the most prevalent factor, followed by economic conditions; On the other hand, it is detected that environmental aspects such as global warming, eutrophication, or acidification, are the least incidents when selecting technologies.

What are possible Sources of Common and Persistent Student Errors in Algebra and Calculus?

Research shows that college students make numerous algebra and other prerequisite content-related errors in Calculus courses. Most of these errors are common, persistent, and often observed in simple mathematical tasks. This qualitative study is an attempt to identify the potential sources of such errors. Based on our observations of student errors, we wrote a Precalculus and a Calculus test and administered them in twelve sections of four different undergraduate mathematics courses for which either Precalculus, Calculus I or both were a prerequisite. The tests were announced on the first day of the class and administered the following week. All the questions on the test were True or False questions. Based on our experience as college mathematics instructors, we assumed that many students would perceive the True answers as False and the False as True. Therefore, if students’ selected a given answer, mathematical statement, process or solution as True, they were asked to justify why that was not False and vice-versa. They were instructed to provide logical explanations and avoid plugging in numbers to check for correctness. Analysis of data using grounded theory approach resulted in the following three possible external sources of common and persistent student errors: a) Difficulty with symbols and/or lack of attendance to the meaning of those symbols, b) Instructional practices, and c) Lack of knowledge. We will provide examples to illustrate how such errors could have originated from these sources.

Между фактом и фантазией: ранние источники по ойратской исторической диалектологии

The article presents the results of a linguistic analysis of three early sources on Oirat historical dialectology, Rashīd al-Dīn’s Jāmiʿ al-Tawārīkh (Compendium of Chronicles, completed between 1306 and 1311) and the Mongol chronicles Sir-a tuγuǰi (Yellow History, between 1651 and 1662) and Erdeni tunumal neretü sudur (The Jewel Translucent Sūtra, c. 1607). The author concludes that these sources substantially differ in terms of their linguistic value and reliability. The early historical accounts of Oirat lexical differences, provided by Rashīd al-Dīn and the unknown author of the Sir-a tuγuǰi, are most likely to have been obtained from unreliable external sources and based on hearsay evidence, orally transmitted by non-Oirats, at best, only passingly familiar with the Oirat language and its actual features. Both authors probably heard something about distinctive lexical features of the Oirat dialects of their time, but they hardly had a clear idea of what these features were and how to explain them in an adequate manner. On the contrary, the ‘Oirat fragment’ contained in the Erdeni tunumal neretü sudur seems to be much closer to fact than to fantasy. It presents a deliberate and quite reliable attempt to introduce some features of the Oirat dialects spoken at the turn of the seventeenth century. In the absence of earlier internal evidence of the linguistic differences between the Mongolic languages, this may be the oldest known representation of dialectal data in the Mongolian literary tradition. The evidence is of special importance because it includes morphophonological (an innovative colloquial shape of the clitics ni ~ n̠i < *inu and la ~ =la < *ele) and morphosyntactic (the progressive/durative in ‑nA(y)i), rather than lexical, features, which seem to have been considered Oirat by the early seventeenth-century author(s) of the chronicle. These features look more genuinely Oirat, at least for the early 17th century, although their modern distribution is certainly rather wide and non-specific. It may be assumed that the information on Oirat dialects that the Erdeni tunumal neretü sudur contains may have been obtained from an Oirat, or, at least, from an individual well-versed in the language of the time. Thus, one cannot overestimate the importance of the chronicle as a highly valuable source on historical dialectology of Mongolic languages.

Big Data between Quality and Security: Dynamic Access Control for Collaborative Platforms

Big Data often refers to a set of technologies dedicated to deal with large volumes of data. Data Quality and Data Security are two essential aspects for any Big Data project. While Data Quality Management Systems are about putting in place a set of processes to assess and improve certain characteristics of data such as Accuracy, Consistency, Completeness, Timeliness, etc., Security Systems are designed to protect the Confidentiality, Integrity and Availability of data. In a Big Data environment, data quality processes can be blocked by data security mechanisms. Indeed, data is often collected from external sources that could impose their own security policies. In many research works, it has been recognized that merging and integrating access control policies are real challenges for Big Data projects. To address this issue, we suggest in this paper a framework to secure data collection in collaborative platforms. Our framework extends and combines two existing frameworks namely: PolyOrBAC and SLA- Framework. PolyOrBAC is a framework intended for the protection of collaborative environments. SLA-Framework, for its part, is an implementation of the WS-Agreement Specification, the standard for managing bilaterally negotiable SLAs (Service Level Agreements) in distributed systems; its integration into PolyOrBAC will automate the implementation and application of security rules. The resulting framework will then be incorporated into a data quality assessment system to create a secure and dynamic collaborative activity in the Big Data context.

Does the COVID-19 Vaccine Still Work That “Most of the Confirmed Cases Had Been Vaccinated”? A Content Analysis of Vaccine Effectiveness Discussion on Sina Weibo during the Outbreak of COVID-19 in Nanjing

In July 2021, breakthrough cases were reported in the outbreak of COVID-19 in Nanjing, sparking concern and discussion about the vaccine’s effectiveness and becoming a trending topic on Sina Weibo. In order to explore public attitudes towards the COVID-19 vaccine and their emotional orientations, we collected 1542 posts under the trending topic through data mining. We set up four categories of attitudes towards COVID-19 vaccines, and used a big data analysis tool to code and manually checked the coding results to complete the content analysis. The results showed that 45.14% of the Weibo posts (n = 1542) supported the COVID-19 vaccine, 12.97% were neutral, and 7.26% were doubtful, which indicated that the public did not question the vaccine’s effectiveness due to the breakthrough cases in Nanjing. There were 66.47% posts that reflected significant negative emotions. Among these, 50.44% of posts with negative emotions were directed towards the media, 25.07% towards the posting users, and 11.51% towards the public, which indicated that the negative emotions were not directed towards the COVID-19 vaccine. External sources outside the vaccine might cause vaccine hesitancy. Public opinions expressed in online media reflect the public’s cognition and attitude towards vaccines and their core needs in terms of information. Therefore, online public opinion monitoring could be an essential way to understand the opinions and attitudes towards public health issues.