bluuebunny/crossref_metadata_2025 huggingface dataset:
Espaço de formação docente centrada na escola: um estudo sobre a hora-atividade
Authors: Prade Conte Camila Aparecida , Bridi Jamile Cristina Ajub
Published: October 2022

Considerando a importância do desenvolvimento docente e da necessidade de troca de experiências com outros professores, desenvolvemos uma pesquisa sobre os resultados que a hora-atividade de estudo, mediada pelo pedagogo, proporciona no trabalho do professor. Fundamentados nos conceitos de Tardif (2005), Pimenta (1999), Sacristán (1991), Nóvoa (1997) e Libâneo (2004), partimos do pressuposto de que esta pode representar um importante instrumento de emancipação do trabalho docente, bem como do trabalho do pedagogo, por meio da leitura, estudo e discussões coletivas diante dos problemas encontrados no processo pedagógico. Com isso, o trabalho analisa a hora-atividade realizada em uma escola estadual localizada no Município de Campo Largo, Paraná. Para responder à tal problema, realizou-se uma pesquisa de cunho qualitativo a partir de observação participante nos momentos de hora-atividade organizados pela equipe pedagógica da escola pesquisada, momentos esses denominados na escola como “hora-de-estudo”. Os resultados evidenciaram que a hora-atividade representa um importante espaço de formação em exercício do professor, proporcionando significativa mudança no processo ensino-aprendizagem, na medida em que favorece que os professores se utilizem de metodologias diferenciadas a fim de alcançar a diversidade dos alunos. Além disso, o momento de estudo torna-se espaço de troca de experiências entre os professores e vem contribuindo para a superação da visão do pedagogo como fiscalizador, passando a compreendê-lo como um aliado.
A importância do estudo da variação linguística dentro da disciplina da Libras no ensino superior
Authors: Andreis-Witkoski Silvia , Maestri Rita De Cássia , Oliveira Giovana Maria de
Published: October 2022

A disciplina da Libras no Ensino Superior passou a ser introduzida nas grades curriculares dos cursos de formação de professores e fonoaudiologia exclusivamente a partir da determinação do Decreto nº 5.626/2005. Vale ressaltar que o próprio reconhecimento oficial da Libras, como meio legal de comunicação e expressão das pessoas surdas, ocorreu somente com a promulgação da Lei nº 10.436/2002. Deste modo, vê-se que até mesmo na legislação brasileira o status linguístico desta como língua deu-se apenas a partir deste período, sendo que ainda permanecem inúmeros mitos em relação às Línguas de Sinais. Diante desse quadro, considera-se fundamental desconstruir os preconceitos linguísticos em relação às Línguas de Sinais, discutindo as concepções subjacentes a elas e aos sujeitos surdos. Nesta perspectiva, entende-se ser fulcral que a variação linguística seja contemplada no currículo da disciplina da Libras, a fim de promover a compreensão de que, tal qual as línguas orais, as sinalizadas também se constituem legitimamente como uma língua, incorrendo nos mesmos processos de variações linguísticas, na medida em que este é um fenômeno intrínseco a todas as línguas. Por isso, no presente artigo, além de problematizar, a partir de uma abordagem histórica, alguns preconceitos remanescentes em relação às Línguas de Sinais e aos seus usuários, exemplifica-se o fenômeno da variação linguística com diferentes sinais que apresentam esta característica, com vistas a ampliar.
Polygonatum praecox (Asparagaceae), a new species from mid-eastern China revealed by morphological and molecular evidence
Authors: Hu Yingfeng , Liu Yujun , Ali Maroof , Wu Wei , Li Xiaohong , Chen Longsheng , Shao Jianwen
Published: October 2022

A new species, Polygonatum praecox Y.F.Hu & J.W.Shao (Asparagaceae), is described and illustrated. This species is similar to P. cyrtonema, P. odoratum and P. caulialatum, but can be distinguished from P. cyrtonema by its racemose inflorescence, cylindrical hairless filaments and apex without a retrorse spur; from P. odoratum by its stout moniliform rhizome, straight stem and longer (1.7–2.2 cm long) floral tube; and from P. caulialatum by its upper part straight stem, yellowish-green corolla, lobes excurved and earlier flowering. The complete chloroplast genome of this new species is 155,115–155,256 bp in length. Phylogenetic analysis revealed that P. praecox is not genetically related to the above three morphological similar species, but is closely related to the two European species (P. multiforum and P. latifolium). This species is relatively common in mid-eastern China and has previously been confused with P. cyrtonema. As its wild resources have decreased in recent years due to over-exploitation for medicinal or edible purposes, we classify it as Near Threatened (NT) according to the IUCN Red List Criteria.
Effects of chicken waste meal and vegetable substrate fed black soldier fly prepupae meal on rainbow trout (Oncorhynchus mykiss)
Authors: Yandi I. , Ozturk R.C. , Terzi Y. , Kayis S. , Altinok I.
Published: October 2022

A feeding trial was conducted to evaluate the effects of the dietary inclusion of black soldier fly (BSF),Hermetia illucens, prepupae in rainbow trout (Oncorhynchus mykiss) fingerling diets on growth performance, fillet quality, and gut and liver histology. Chicken waste meal and fruit & vegetable waste (1:9, v:v) were used as feeding substrates of BSF prepupae. Five diets were prepared: a basal diet (B0) based on fish meal (FM) and four additional diets in which BSF meal (BSFM) was used to replace 25, 50, 75, and 100% of the FM (B25, B50, B75, and B100, respectively). Orthogonal polynomial contrast was used to determine the trend between BSFM inclusion levels and growth parameters, fatty acids, and amino acids. Quadric relationships between the BSFM levels and growth parameters, including length and weight gain rate, specific growth rate (SGRW), and feed conversion rate, were determined. The optimum BSFM inclusion rate for the best SGRW was estimated at 11.9%. With the exception of the B100 group, increasing the BSFM level in the diet generally increases the fatty acid composition of whole fish. Dietary BSFM inclusion resulted in a significant increase in goblet cells in the proximal and distal intestines, as well as muscle layer thickness in the proximal intestine. A histological study showed that substituting fishmeal with BSFM had no effect on liver lipid accumulation. This study showed that replacing FM with BSFM in rainbow trout fingerling diets by 50% had no adverse effects on the growth performance, liver characteristics, feed utilisation, or fillet quality. Therefore, the BSFM described here can safely be used on rainbow trout fingerling diets. As a result, rainbow trout fingerlings can be fed 50% FM/BSFM replacement without adding additional essential amino acids to the diet or eliminating chitin from BSFM using the methods we used to culture BSF.
Experimental investigation of improving the solar desalination system for domestic buildings: Iraq as a case of study
Authors: Al-Rubaye Layth Abed Hasnawi , Al-Samari Ahmed , Faris Saad Theeyab , Hafedh Saadoon Abdul
Published: October 2022

Iraq encounters climatic challenges that lead to severe rainfall shortages and compound the regional challenges that lead to reduced rates of supplying rivers. In this research, the proposed design helps obtain pure water from polluted or saline water t lower, more competitive costs that can supply nearly 80% of the Iraqi markets.

The system harvests 2 L/day of pure water by adding 5 liters of saline water, a 209% daily improvement. The system consists of 1.125 m2 of double slope single basin solar still with a tilt angle of 30°, pipes, and measurement instrumentation.

Maximum inside temperature, humidity, valuable energy, and efficiency have 77 ℃, 35%, 4.02 W/m2, and 76%, respectively. System analysis results demonstrated that the average water condensation rate per square meter is about 0.4 L/hr. Finally, the rate of pure water harvesting from this desalination system, per square meter, is about 0.282 L/m2 per day when the average intensity of solar radiation reaches 165 W/m2. Two scenarios have been suggested for the experiment. The first scenario tests the system by limiting two water levels, the first at 0.75 cm and the second at 3 cm. The second scenario includes the same design with a black cloth set in the basin demonstrates the most promising data. A wet pad regularly cools down one side of the glass to increase the water vapor condensation and production quantity by 173% to enhancing water production significantly.
Flip bifurcation and Neimark-Sacker bifurcation in a discrete predator-prey model with Michaelis-Menten functional response
Authors: Li Xianyi , Shao Xingming
Published: October 2022

In this paper, we use a semi-discretization method to explore a predator-prey model with Michaelis-Menten functional response. Firstly, we investigate the local stability of fixed points. Then, by using the center manifold theorem and bifurcation theory, we demonstrate that the system experiences a flip bifurcation and a Neimark-Sacker bifurcation at a fixed point when one of the parameters goes through its critical value. To illustrate our results, numerical simulations, which include maximum Lyapunov exponents, fractal dimensions and phase portraits, are also presented.
Clientélisme politique et recommandations
Authors: Bour Julie
Published: October 2022

« Cli-en-té-lis-me », le mot est ancien, dure et perdure. Mais de quoi parle-t-on au juste? « Je connais tel élu et il a le bras long, il pourra me trouver une place à la mairie! » Si la phrase est courante, quelles réalités et quels fantasmes recouvre-t-elle précisément ?
Alors que le phénomène du clientélisme a déjà fait l’objet de plusieurs études en sociologie et sciences politiques, cette pratique originale a moins retenu l’attention des historiens du politique. Spécialiste de l’histoire politique française contemporaine, Julie Bour entend étudier les acteurs, causes, modalités et limites du clientélisme via une approche quantitative originale et inédite, reposant sur l’exploitation statistique de corpus importants de courriers de recommandation, dépassant parfois les milliers de lettres entre les élus et leurs administrés et portant sur des dossiers sensibles, symboliques ou plus prosaïques (emplois, décorations, service militaire, aide sociale, affaires communales, etc.). Elle concentre son analyse sur un espace test particulier qui est celui de la Lorraine et l’appréhende sur le temps long qui va de la IIIe République aux années 2000. Au travers d’études de cas portant sur des élus célèbres (Louis Jacquinot, Pierre Messmer, François Guillaume, Christian Pierret) ou plus anonymes (Jean Bernard, Jules Develle, André Savard) qui représentent l’ensemble des courants politiques, le clientélisme apparaît pour ce qu’il est réellement : une pratique très répandue (et non limité à un Sud méditerranéen arriéré), qui structure la vie politique locale, mobilise tout un réseau d’intercesseurs relais, crée des solidarités fines entre l’élu et les électeurs, et joue un rôle parfois déterminant dans l’élection et la longévité politique de certains parlementaires. Cette pratique, ancrée sur la durée, institutionnalisée au point d’être déculpabilisée, interroge la démocratie dans ses limites en termes de corruption et de clientélisme.
Finistère du Front populaire
Authors: Sénéchal Jean-Paul
Published: October 2022

Cet ouvrage se propose d’analyser l’impact du Front populaire sur le Finistère, département rural fortement marqué par la question religieuse. Évitant une approche surplombante, le cadre choisi permet d’appréhender au plus près les fractures de la société finistérienne, entre villes et campagnes, entre blancs et bleus, entre dominants et dominés. La pénétration des idées sociales est faible dans les campagnes. Un puissant syndicalisme agricole s’y développe en s’arrogeant le rôle d’un contre-État. En face, la société urbaine vit ses propres antagonismes. L’Église catholique, présente dans les deux mondes, tente de conforter son emprise sur l’ensemble de la société et se retrouve de fait en concurrence avec les élites agrariennes. L’arrivée des gauches au pouvoir radicalise les positions. L’irruption d’une séquence gréviste inédite oblige les uns et les autres à s’adapter. Les forces adverses mettent en place des stratégies mimétiques qui cherchent à accompagner plutôt qu’à affronter le réveil ouvrier. Les changements d’échelle permettent d’étudier tous les moyens utilisés, du consentement jusqu’à la coercition. Loin d’une histoire fractale, nous avons privilégié une histoire mosaïque. Pour autant, le Finistère du Front populaire, avec ses particularités, s’inscrit dans le cadre national. Cet ouvrage est une contribution à l’histoire de cet événement majeur dans un département catholique et rural.
Theoretical Analysis of the Thermodynamic, Structural, Surface and Transport Properties of PbSn Liquid Alloys at 1050 K
Authors: Chaudhary Rajendra Prasad , Kumari Nitu , Mandal Jagdhar , Jha Indu Sekhar
Published: October 2022

The thermodynamic, structural, surface and transport properties of PbSn eutectic alloys at 1050 K have been analyzed employing self association model. The model parameters have been evaluated on utilizing the experimental data of free energy of mixing of PbSn liquid alloys at 1050 K. For the validation of the model parameters, the calculated values of the excess free energy of mixing and activity of the components of PbSn liquid alloys have been compared with the experimentally measured data. Further, the estimated model parameters have been used to determine the thermodynamic functions i.e. the free energy of mixing, thermodynamic activity, entropy of mixing and heat (or enthalpy) of mixing, and the structural properties such as the concentration fluctuations and shortrange order parameter. The theoretical and experimental values are compared. A good agreement is observed. Again, the surface properties of PbSn liquid alloys at 1050 K have been investigated using the Butler model in the framework of self association model. The calculated values of surface tension of PbSn liquid alloys at 1050 K are in reasonable agreement with the data available in the literature. The transport properties like the diffusivity and viscosity of PbSn liquid alloys at 1050 K have been theoretically analyzed. For the computation of viscosity, the simple formula developed by Moelwin- Hughes has been used in conjunction with self association model. The present study reveals that PbSn eutectic liquid alloys at 1050 K are segregating in nature. Further, the model parameters are found to depend on temperature.Keywords: Gibbsfree energy; concentration fluctuations; short-range order parameter; surface tension; diffusivity; viscosity
High Temperature Stability of K-Pb Liquid Alloy
Authors: Panthi Narayan , Bhandari Indra Bahadur , Koirala Ishwar
Published: October 2022

The study explores the thermo-physical properties of complex binary liquid potassium-lead alloy at temperature 848 K as a function of concentration by considering complex using different model equations. The Quasi Chemical approximation and the R-K equation are used to investigate features such as free energy, heat of mixing, chemical activity, and concentration fluctuation in the long wave limit at temperature of 848 K. However, at 900 K and 1000 K, these are exclusively examined using the R-K equation. The temperature dependent exponential interaction parameters proposed by Kaptay are taken into account in the RK equation. The study goes on to look at the alloy's viscosity and surface tension using the Budai-Benko-Kaptay model and the Kaptay's improved derivation of Butler equation. The mixing nature of the system is investigated in depth, with a focus on the interaction energy parameters between the alloy's surrounding atoms. The work investigates the fact that the liquid alloy has a moderately interacting as well as ordering character throughout a whole concentration range, and the computed theoretical thermodynamic facts are in reasonable agreement with the corresponding experimental data at 848 K. At greater temperatures, the alloy's tendency goes from ordering to segregating. The alloy's viscosity and surface tension decrease as the temperature rises.
Temperature Effect on Deformation Response in Austenitic Stainless Steel
Authors: Barannikova Svetlana A. , Iskhakova Polina V.
Published: October 2022

Stress-strain behavior of austenitic stainless steel grade AISI 304 was investigated by means of uniaxial tensile tests and magneto-phase analysis. The test materials were strained in tension within the temperature range of-100 ≤ T ≤ +100 °C. According to the results, intensive strain hardening occurs in austenitic stainless steel when strain-induced α’- martensite is present in the material, and stress-strain behavior is associated with the increase yield strength and tensile strength with decreasing temperature. The analysis of the hardening kinetics reveals that kinetics are affected by the temperature and by the amount of α’- martensite content.
Obstacles for the Growth and Development of Small and Medium Enterprises in Sri Lanka: Case of North Western Province
Authors: Kuluppuarachchi M. K. , Athauda A. M. T. P. , Wijeyewardena H. M. S. L.
Published: October 2022

The backbone of the Sri Lankan economy is formed by Small and Medium Enterprises (SMEs) which is an essential component in a competitive and efficient market. New SMEs’ role in the economy is vital as it addresses the issues of sustainable development; job creation, economic growth, competitive market pressure and the overall stimulation of the country’s economy. SME failure rate in Sri Lanka is quite as high as 45%. Therefore, the primary objective of this study was to examine both internal and external organizational factors which are acting as obstacles for the growth of new SMEs in Sri Lanka. Thirty four major variables were identified as obstacles through Focus Group Discussions and literature review. Principal Component analysis (PCA) with Varimax Rotation was used to reduce the identified variables into five components. The most perceived obstacle was termed as Finance which is largely internal to the firm with an Eigen value of 8.17 and a percentage variance of 24%, while the other obstacles determined by PCA were Management (internal), Market (external), Infrastructure (external) and Economic (external) in descending order. The PCA has emphasized the stringency of providing collaterals/guarantees to obtain bank loans as the most impeding obstacle for the growth of new SMEs in Sri Lanka. Therefore, the study suggests that it is needed to revisit the micro finance accessibility of SMEs in the North Western Province (NWP) and to support them in formulating effective financial management plans within their early years from the inception to avoid failures.
Economic Valuation of Urban Coastal Ecosystem Services and Scenic Beauty
Authors: Ranjan K. R. H. M. , Guruge T. P. S. R. , Jayasinghe-Mudalige U. K.
Published: October 2022

A lagoon ecosystem provides a variety of ecological functions that directly or indirectly translate to economic services and values. The impact of the loss of cultural services is scarce in literature and particularly difficult to measure. This study generates monetary value for urban ecosystem services specifically the aesthetic value of a natural asset according to the perception of the adjacent community. The data were gathered by using a pre-structured, questionnaire-based personal interview carried out with 300 households representing 15 ‘Thotupola’ areas adjacent to the estuary. Choice Experiment (CE) was used to determine the preferences and the willingness to pay for conservation of urban ecosystem services and natural view. Highest value (530.75) was recorded for provisioning services. Marginal willingness to pay (MWTP) for prawns (272.25) was higher than the value of (258.50) crabs. Second highest MWTP (309.50) was acquired by recreation attribute, scenic beauty of the lagoon. Moreover, local fishing community does not willing to pay for regulatory services such as reduction of flood damage by mangrove and cleaning of polluted lagoon water. Understanding the degree and order of importance of ecosystem non-use values for its direct users is critical for planning for optimum and sustainable management, as properly managed ecosystem can provide continued returns to future generation without diminishing its productivity. The study generates information for decision makers with regard the monetary values for conservation of different ecosystem services and estuary view, to protect the estuary ecosystem through implementing policies and management plans, on urban estuaries and mangrove environment protection.
Vegetable Buying Behavior in Kurunegala District
Authors: Debarawatta R. D. N. , Azardeen O.
Published: October 2022

Dietary patterns rich in high vegetable intake are associated with a myriad of health benefits. The objective of this study was to explore the vegetable consumption behavior of consumers within the Kurunegala District. The specific objectives were to identify vegetable consumption rate among the cohort, to identify the barriers over vegetable consumption and to establish a relationship between factors affecting vegetable consumption. The results of descriptive analysis showed that females were making purchasing decisions in urban and semi urban areas except rural areas. Fair is the most popular place where rural (52%), semi urban (50%) and urban (42%) respondents purchased vegetables. The highest percentage of semi urban respondents (28%) used to purchase vegetables from groceries, while most of the respondents of rural area cultivated their own vegetables. Daily vegetable intake of majority of the respondents from rural and semi urban areas were below the World Health Organization (WHO) recommended amount of 260 grams of vegetables per day. However, low income level households consume vegetables below the standard rate while, the high income level households intake vegetables above (336.2 g/day) the recommended rate. The results of the Binary Logistic Regression indicated that consumers in the urban sector have higher probability of consuming required rate of vegetables.
Environmental Challenges and the Sustainable Development Goals: A Study about the Emerging Environmental Issues in Sri Lanka
Authors: Athukorala W. , Karunarathna M.
Published: October 2022

Poverty, inequality, economic as well as social instability and environmental degradation are common features of unsustainable development. In general, the need for sustainable development is rarely at the top of priority lists of the people in developing countries because their livelihoods are mainly depended on available economic opportunities and environment variables. As a developing country, Sri Lanka has shown a progress of many aspects in sustainable development goals. However, irresponsible planning, unplanned development activities, absence of a proper monitoring as well as evaluation system and lack of knowledge on sustainable development has resulted in damaging the ecosystems over the last few decades. In this context, this study attempts to investigate the direction of some of the key environmental variables in the country. It also analyses the knowledge and attitudes of people in Sri Lanka towards the sustainable development, climate changes, forest as well as biodiversity conservation and government policies. Results show that performances of most environmental indicators are not consistent with achieving main targets set up under the sustainable development goals. It is found that people as well as policy makers have given low priority on sustainable development and environment which may be one of the main reasons for environmental degradation in the country.
Restructuring Extension on Herbicide Usage of Paddy Farmers in Anuradhapura District
Authors: Kuruppu I. V.
Published: October 2022

Among various novel technologies which have been adopted in agriculture, agro-chemical usage is very wide. Herbicide is one such agro-chemical used extensively by farmers around the globe. It is believed that herbicides are a must for commercial level cultivation in order to eliminate unnecessary competition of weeds. However, in recent past, there have been many incidences of excess usage of herbicides, causing direct health and environmental issues around the world, including in Sri Lanka. In light of this, objective of the study is to explore how paddy farmers in Anuradhapura District utilize herbicides, factors affecting herbicide usage and to explore the most effective extension point related to herbicides usage. Four district secretaries namely: Nochchiyagama (n=68) and Thabuththegama (n=62) representing major irrigation scheme; Galenbidunuwewa (n=60) and Kahatagasdigiliya (n=60) representing minor irrigation scheme were proportionately selected according to farmer number. A multiple linear regression model was deployed to elicit the relationship between selected factors with usage of chemicals. Primary data were collected randomly from a sample of 250 farmers, targeting 2014/15 maha season. Results highlighted, frequency of extension received by the farmer (p<0.01), degree of understanding the label (p<0.05), education level (p<0.1), age of the farmer (p<0.05) and farming know-how (p<0.01) were significant on herbicide usage. Most frequently overused herbicide was Glyphosate (93%) and the exact amount would be 26.64g per acre. The overall average exposed time to chemicals for an individual was 3.5 hours per acre and average land extent was 5.5 acres. Only a very few (2%) used safety mix (gloves, masks, caps and boots) during handling and spraying of herbicides. Interestingly, the study revealed that the highest number of farmers (36%) preferred primary extension source on herbicide as agro-chemical retailers. Most effective extension point was identified as the agro-chemical retailer. Therefore, formal extension services should augment both agro-chemical retailer and distributors. As a regulatory body government should conduct regular monitoring process of the overall extension services.
Factors Affecting the Consumption of Inland Fish: An application of the Theory of Planned Behaviour
Authors: Jayasinghe J. M. J. K. , Sasikaran S. , Jayasinghe C. V. L.
Published: October 2022

The aim of this study was to investigate the factors influencing inland fish consumption of consumers in Sri Lanka using the conceptual framework of the theory of planned behaviour. The data were collected from 219 consumers through a well-structured questionnaire administered in two districts. The study analysed the relationships between inland fish consumption, purchase behaviour, intention, attitudes, subjective norms and perceived behavioural control. Pearson correlation coefficient was used to identify the variables having significant impact. The results indicated that buying inland fish was significantly (p<0.01) influenced by intention of consumers. Attitudes, subjective norms and perceived behavioural control were positively and significantly (p<0.01) correlated with the intention of the respondents. The consumption of inland fish was highly associated with the intention and perceived behavioural control of consumers. The study highlighted the importance of designing and implementing appropriate policies to educate people and enhance the consumption of inland fish with a view to improve their protein intake.
Human CD99L2 Regulates a Unique Step in Leukocyte Transmigration
Authors: Rutledge Nakisha S , Ogungbe Faith T , Watson Richard L , Sullivan David P , Muller William A
Published: October 2022

CD99-like 2 (CD99L2 [L2]) is a highly glycosylated 52-kDa type 1 membrane protein that is important for leukocyte transendothelial migration (TEM) in mice. Inhibiting L2 using function-blocking Ab significantly reduces the recruitment of leukocytes to sites of inflammation in vivo. Similarly, L2 knockout mice have an inherent defect in leukocyte transmigration into sites of inflammation. However, the role of L2 in inflammation has only been studied in mice. Furthermore, the mechanism by which it regulates TEM is not known. To study the relevance to human inflammation, we studied the role of L2 on primary human cells in vitro. Our data show that like PECAM and CD99, human L2 is constitutively expressed at the borders of endothelial cells and on the surface of leukocytes. Inhibiting L2 using Ab blockade or genetic knockdown significantly reduces transmigration of human neutrophils and monocytes across endothelial cells. Furthermore, our data also show that L2 regulates a specific, sequential step of TEM between PECAM and CD99, rather than operating in parallel or redundantly with these molecules. Similar to PECAM and CD99, L2 promotes transmigration by recruiting the lateral border recycling compartment to sites of TEM, specifically downstream of PECAM initiation. Collectively, our data identify a novel functional role for human L2 in TEM and elucidate a mechanism that is distinct from PECAM and CD99.
Synthetic Oligodeoxynucleotide CpG Motifs Activate Human Complement through Their Backbone Structure and Induce Complement-Dependent Cytokine Release
Authors: de Boer Eline , Sokolova Marina , Quach Huy Q , McAdam Karin E , Götz Maximilian P , Chaban Viktoriia , Vaage Jarle , Fageräng Beatrice , Woodruff Trent M , Garred Peter , Nilsson Per H , Mollnes Tom E , Pischke Søren E
Published: October 2022

Bacterial and mitochondrial DNA, sharing an evolutionary origin, act as danger-associated molecular patterns in infectious and sterile inflammation. They both contain immunomodulatory CpG motifs. Interactions between CpG motifs and the complement system are sparsely described, and mechanisms of complement activation by CpG remain unclear. Lepirudin-anticoagulated human whole blood and plasma were incubated with increasing concentrations of three classes of synthetic CpGs: CpG-A, -B, and -C oligodeoxynucleotides and their GpC sequence controls. Complement activation products were analyzed by immunoassays. Cytokine levels were determined via 27-plex beads-based immunoassay, and CpG interactions with individual complement proteins were evaluated using magnetic beads coated with CpG-B. In whole blood and plasma, CpG-B and CpG-C (p < 0.05 for both), but not CpG-A (p > 0.8 for all), led to time- and dose-dependent increase of soluble C5b-9, the alternative complement convertase C3bBbP, and the C3 cleavage product C3bc. GpC-A, -B, and -C changed soluble fluid-phase C5b-9, C3bBbP, and C3bc to the same extent as CpG-A, -B, and -C, indicating a DNA backbone–dependent effect. Dose-dependent CpG-B binding was found to C1q (r = 0.83; p = 0.006) and factor H (r = 0.93; p < 0.001). The stimulatory complement effect was partly preserved in C2-deficient plasma and completely preserved in MASP-2–deficient serum. CpG-B increased levels of IL-1β, IL-2, IL-6, IL-8, MCP-1, and TNF in whole blood, which were completely abolished by inhibition of C5 and C5aR1 (p < 0.05 for all). In conclusion, synthetic analogs of bacterial and mitochondrial DNA activate the complement system via the DNA backbone. We suggest that CpG-B interacts directly with classical and alternative pathway components, resulting in complement-C5aR1–dependent cytokine release.
Cytokine Receptor Diversity in the Lamprey Predicts the Minimal Essential Cytokine Networks of Vertebrates
Authors: Boulay Jean-Louis , Du Pasquier Louis , Cooper Max D
Published: October 2022

The vertebrate adaptive immune systems (Agnatha and Gnathostomata) use sets of T and B lymphocyte lineages that somatically generate highly diverse repertoires of Ag-specific receptors and Abs. In Gnathostomata, cytokine networks regulate the activation of lymphoid and myeloid cells, whereas little is known about these components in Agnathans. Most gnathostome cytokines are four-helix bundle cytokines with poorly conserved primary sequences. In contrast, sequence conservation across bilaterians has been observed for cognate cytokine receptor chains, allowing their structural classification into two classes, and for downstream JAK/STAT signaling mediators. With conserved numbers among Gnathostomata, human cytokine receptor chains (comprising 34 class I and 12 class II) are able to interact with 28 class I helical cytokines (including most ILs) and 16 class II cytokines (including all IFNs), respectively. Hypothesizing that the arsenal of cytokine receptors and transducers may reflect homologous cytokine networks, we analyzed the lamprey genome and transcriptome to identify genes and transcripts for 23 class I and five class II cytokine receptors alongside one JAK signal mediator and four STAT transcription factors. On the basis of deduction of their respective orthologs, we predict that these receptors may interact with 16 class I and 3 class II helical cytokines (including IL-4, IL-6, IL-7, IL-12, IL-10, IFN-γ, and thymic stromal lymphoprotein homologs). On the basis of their respective activities in mammals, this analysis suggests the existence of lamprey cytokine networks that may regulate myeloid and lymphoid cell differentiation, including potential Th1/Th2 polarization. The predicted networks thus appear remarkably homologous to those of Gnathostomata, albeit reduced to essential functions.
Panel-Method-Based Path Planning for eVTOL in Urban Environment
Authors:   Middle East Technical University, Unal Zeynep , Yavrucuk Ilkay
Published: October 2022

In this study the panel method used in fluid dynamics, is applied to the path planning problem of electric vertical take-off and landing (eVTOL) vehicles in urban environment. For an urban air mobility scenario the path planning problem of these vehicles includes the simultaneous operation of large number of vehicles around complex shaped buildings and architectural structures. Using the panel method, flow around complex shaped obstacles is modeled and calculated stream-lines of the fluid flow are used as trajectories for the eVTOL traffic. Since, streamlines do not cross each other or obstacles, using streamlines as vehicle trajectories guarantees collision free paths for vehicles. Moreover, source and sink elements are used to avoid collision of vehicles with each other in case of emergency, and attract the vehicles to target points. The application of panel method provides a solution to the whole path planning problem for multiple vehicles in a single step. Assuming complete knowledge of the city map, the path of each eVTOL vehicle in an air taxi fleet can be determined simultaneously.
Development of "Aria," a Compact, Ultra-Quiet Personal Electric Helicopter
Authors:   Texas A&M University, Coleman David ,   Crystal Instruments, Subramanian Vishaal ,   Pennsylvania State University, Greenwood Eric ,   Science and Technology Corporation, Lakshminarayan Vinod , Benedict Moble , Denton Hunter , Halder Atanu , Lee Bochan , Runco Carl , Saemi Farid
Published: October 2022

This paper describes the development and flight testing of a personal air vehicle by team Harmony for the Boeing GoFly X-prize challenge. For the $1mil grand prize, aircraft were scored by compact size, speed, low noise, and endurance. The team chose a coaxial electric helicopter configuration to maximize rotor area and reduce disk loading for efficiency and acoustic benefits. The rotors were designed through an extensive parametric study using an in-house performance code. Air loads were modeled in HPCMP CREATE™-AV Helios for validation, then used in an inhouse acoustics solver to estimate sound pressure levels. A quiet electric power train was developed, as well as a custom 11kWh, 200lb (90.7kg) battery pack. The flight dynamics of the configuration were modeled and the stability analyzed. Structural analysis was utilized in designing key load-bearing parts. Flight control was implemented with dual, independent, electronically coupled swashplates. First, a 1/3rd scale prototype aircraft was developed to validate the design and acoustic predictions. Then a full-scale, 520lb (235.4kg) prototype with an 8.5ft (2.59m) rotor diameter was developed and accumulated 19.5hrs of testing time. During hovering, the sound pressure levels at 50ft (15.24m) were 73dBA, remarkably low for a rotorcraft. The results of this study underscored the endurance limitation of electric flight due to poor battery performance, as well as the need for reliable, lightweight hardware for such applications.
Analysis of Bus Voltage Sag during High Battery Power Operations on Hybrid Electric Urban Air Mobility Vehicles
Authors:   Embry-Riddle Aeronautical University, Collins Kyle , Anderson Richard , Currier Patrick , Fernandes Roydon , Lahaji Sohail , Shivakumar Jayaprakash
Published: October 2022

This paper analyzes test results performed on a hybrid-electric power generator where the effects of voltage sag caused the inverter to lose the ability to control the generator. The prototype generation system consisted of a four-cylinder Rotax 915iS turbocharged gasoline aviation engine driving a YASA P400RHC high performance generator controlled by a Cascadia PM150DZ inverter. The system was designed to be incorporated into an eVTOL type of vehicle to provide power to distributed electric rotor systems. The prototype power generation system was connected to an active DC electronic resistive load that pulled current from the prototype based on an arbitrary power versus time profile. When driven by the Rotax at 5,500 RPM and 100% throttle, the YASA generator is capable of producing about 85-90 kW. As more power is demanded from the system, the battery pack – which has a starting voltage of approximately 420 V – has to provide the remaining power. When this power demand from the battery is high, the battery pack voltage begins to drop. The Permanent Magnet Synchronous Machine (PMSM) generator has both voltage and current limits that limit the amount of torque the generator can produce to balance the torque input from the Rotax. The voltage limit is partially a function of the bus voltage, which is dictated primarily from the battery pack voltage. When these limits are reached, the system can no longer keep the speed controlled and the Rotax torque, being unbalanced by the YASA, causes the engine to over-speed. This paper analyzes test results where the system is intentionally loaded to produce this behavior and cause the over-speed. A simplified model of the PMSM current and voltage limits are developed to notionally simulate the phenomenon.
Post-Motor-Failure Performance of a Robust Feedback Controller for a UAM-Scale Hexacopter
Authors:   Rensselaer Polytechnic Institute, Bahr Matthew , Gandhi Farhan , McKay Michael , Niemiec Robert
Published: October 2022

The performance of two flight controllers is compared for a 1200 lb hexacopter following single rotor failure. A nominal flight controller is tuned to meet handling qualities specifications for the healthy aircraft in forward flight, and a robust two-plant controller is tuned to also satisfy the same set of handling qualities specifications following front rotor failure. This two-plant controller is tuned to simultaneously meet the handling qualities for the healthy and failed aircraft. In both cases, the flight controllers do not utilize knowledge of the rotor failure. The performance of the controllers is compared for single rotor failures of the front and side rotors. For front rotor failures, the two plant controller decreases the peak pitch deviation by 3.5◦ and provides a more well damped response, but does not provide significant benefit during side rotor failure. Various maneuvers are also performed for each controller to evaluate the cost for using the robust controller in normal operation. The largest torque difference, a pitch doublet, requires 8 ft-lb additional torque for the two-plant controller, while the peak torque requirement for maneuvers occurs during a yaw rate step, where about 140 ft-lb of torque is required for the nominal controller (143 ft-lb for the two-plant). For both controllers, recovery following rotor failure requires substantially more torque (280 ft-lb) than the different maneuvers considered. Therefore, motor sizing is limited by rotor failure cases, not normal operation.
Modelling of a Hybrid-Electric System and Design of Load-Following Control Law on Hybrid-Electric Urban Air Mobility Power Plants
Authors:   Eagle Flight Research Center, Lahaji Sohail ,   Embry-Riddle Aeronautical University, Currier Patrick , Anderson Richard , Collins Kyle
Published: October 2022

This paper describes the developed control strategies for the hybrid-electric engine system for Urban Air Mobility (UAM) applications by the Eagle Flight Research Center (EFRC) at Embry-Riddle Aeronautical University (ERAU). It will also provide details of the hybrid-electric engine simulation developed in MATLAB with Simulink and Simscape to test the control logic. Simulation models of the internal combustion engine, generator, invertermotor controller, battery pack, load generator (UAM vehicle) along with a supervisory controller are detailed in the paper. These control strategies were then implemented on a 100kW hybrid power plant to test and validate the effectiveness of the control system. The power plant consists of a 4-cylinder turbocharged Rotax 915iS gasoline engine powering YASA P400RHC. The system also consists of a Cascadia PM 150 DZ to control the generator along with Lithium-ion battery packs connected in parallel. This paper explains the supervisory controller that manages all the components within the hybrid-electric power plant to achieve the required power. The principal concepts in controlling the system are meeting the powertrain load requirement from the generator, regulating the battery current to zero, and maintaining the state of charge (SOC) of the battery pack.
A CFD Based Method to Model Aerodynamic Interactions in Complex eVTOL Configurations for Realtime and Medium Fidelity Simulation
Authors:   Joby Aviation, Mikic Gregor , Bain Jeremy , Bevirt JoeBen , Stoll Alex
Published: October 2022

A method is presented that captures complex interactional aerodynamics between various aerodynamic components of eVTOL or other aircraft configurations. The fluid around the aircraft is modeled as a free Euler flow, where various aircraft components are acting as distributed force density sources within that flow. The method supports reconfigurable aircraft configurations without changes to the underlying mesh. The formulation allows for realtime simulation that can be used directly in conceptual design to evaluate controllability, accelerate controls development, and support system simulations. In non realtime simulations it can be used as a medium fidelity tool to capture interactional aerodynamic effects in more comprehensive aircraft simulations.
Impact of Handling Qualities on Motor Sizing for Multirotor Aircraft with Urban Air Mobility Missions
Authors:   NASA Ames Research Center, Withrow-Maser Shannah , Malpica Carlos , Nagami Keiko
Published: October 2022

Control models of three NASA Urban Air Mobility (UAM) reference vehicles (the quadrotor, octocopter, and Lift+Cruise (LPC)) were created and compared to determine the effect of rotor number and disk loading on control margin and design. The heave and yaw axes demand more actuator usage than the roll and pitch axes. Between heave and yaw, heave was the more demanding of the two because of the dependence of heave on the engine speed controller (ESC). When the feedback gains for all three vehicles were optimized to Level 1 handling qualities (HQs) specifications using CONDUIT, the ESC for the octocopter was the most stable and had the highest rise time (time for the rotor to respond to an input), while the LPC ESC was the least stable and had the smallest rise time. Rise time corresponds to the time required for rotor response. When actuator usage was translated to current margin, torque margin, and power margin, heave was the most demanding axis, followed by yaw, roll, and then pitch for all three vehicles. The results emphasize the importance of an accurate motor model within the control system architecture.
Evaluation of the Phase-Aggression Criterion for PIO Detection in Real-time
Authors:   University of Liverpool, Fasiello Simone ,   Politecnico di Milano, Masarati Pierangelo , Jump Mike
Published: October 2022

This paper presents the results of a pilot-in-the-loop experiment performed to investigate the efficacy of a pilot induced oscillation (PIO) or adverse rotorcraft-pilot coupling (RPC) real-time detection method, to be implemented as an in-cockpit warning system. A test pilot performed a number of simulated flights inside the Heliflight-R simulator at the University of Liverpool. Two handling qualities (HQ) mission task element (MTE) maneuvers were chosen, namely Precision Hover and Lateral Reposition. The baseline dynamics were those of a FLIGHTLAB BO105-like helicopter model, as used in previous tests; changes in rate limits were introduced to induce the pilot-vehicle system (PVS) to be more RPC/PIO prone, and to observe pilot’s adaptation to these variations causing system instabilities during the chosen MTEs. To objectively measure the severity of the PIO encountered during the tests, the PhaseAggression Criterion (PAC) has been used. This method has been developed to allow for real-time PIO detection in order to provide the information inside the cockpit. In addition, pilot subjective ratings were collected, by using the HQs, PIO and Pilot Workload rating scales. Overall, the results show a good correlation between objective and subjective evaluations, and that it is possible to detect PIOs in real-time. The information can be provided to the pilot by means of visual, aural or haptic cues, which is the work the authors are currently carrying out.
Probabilistic Techniques for Pilot-Vehicle Interaction and Handling Qualities Analysis
Authors:   Barron Associates Inc., Cooper Jared ,   Systems Technology Inc., Klyde David , DeVore Michael , Reed Adam , Schulze Chase
Published: October 2022

This article demonstrates application of the probabilistic analysis facility AURA to rotary-wing handling-qualities and pilot-vehicle interaction analysis. Modeling and analyzing rotorcraft flight dynamics, handling-qualities, and pilot interaction requires sophisticated tools to capture the complex physical phenomena germane to their operation. Present and future rotorcraft operational requirements demand the vehicles perform in new and increasingly austere environments. Initiatives such as the Urban Air Mobility (UAM) envision an expansion of pilot training to allow non-expertly trained pilots to safely operate UAM vehicles, aided by sophisticated autonomous systems. Pilot-vehicle interaction studies in the past have largely focused on assessing the control system design, including robustness of the controller to modeling uncertainties and external disturbances, and the handling qualities of the pilot-vehicle system. In this analysis the pilot model is generally formulated to reflect a well-trained pilot; however, programs such as the UAM advocate for pilots of varying skill levels and proficiency. As such, this article investigates pilot-vehicle interactions across a range of uncertainties present in both the plant and pilot models to reflect this spectrum of pilot variability. This technique is also applicable to fleets with more qualified pilots as there is still a range of pilot tendencies and preferences. This article outlines the approach and demonstrates applications to rotorcraft handling-qualities and pilot-vehicle interaction analysis.