bluuebunny/crossref_metadata_2025 huggingface dataset:
The Concept of an Imperial City in The Modern Global World
Authors: Maltseva Yulia
Published: January 2021

Research background: The author analyzes the phenomenon of cultural identity of the city and its cultural and economic aspects which allows us to create the concept of the Imperial city, and analyze its relationship with its own historical background and ideas about the global city. Structural analysis of modern ideas about the Imperial city allows us to ensure a strong urban brand and influences its global competitiveness.

Purpose of the article: The article is devoted to the problem of forming strong brands of certain territories, in particular, Imperial cities, and their impact on the competitiveness of the region.

Methods: The multidisciplinary approach to the analysis of a chosen phenomenon combining economic-statistical and cultural-philosophical methods to assess the mutual influence of the city’s globality and its Imperia concept on the formation of its distinctive ecnomically strong brand.

Findings & Value added: The analysis showed that a new understanding of the phenomenon of the Imperial city, strengthening its brand, increasing recognition in the world and close ties with cultural dominants allows the Imperial cities to attract significant financial investments and improve their competitive position at the global market. As a scientific growth, the author can consider the influence of the Imperial city concept on the structure of the formation of a successful urban brand of a territory. The author proposes the new methodology for assessing the brand value of the Imperial City.
Influence of communication tools on customer behaviour within a food product after declared consumption date in global
Authors: Mráček Pavel , Milichovský František
Published: January 2021

Research background: Marketing communication should catch the attention of target customers, who pay attention to advertisements to make an interest in product, service, brand, or company. Marketing communication can impact customers behaviour in food choice due to association with personal identity, which is important interpersonal communication to others.

Purpose of the article: Customers purchase a lot of food with no matter the possibility of consumption. Therefore, a lot of foods are wasted or degraded for consumption, because of health risks. It is necessary to influence target customers and change their mind setup and their purchasing behaviour in global retail chains.

Methods: As primary research, a questionnaire survey was used. For the survey was asked 1042 persons to participate. From asked persons, we receive 451 questionnaires, which mean 43,28 %. In the amount of returned questionnaires, we had to remove 23 lists as incomplete. The total complete forms were 428 (41,08 % of asked). For the evaluation of gained data, there was applied Pearson’s chi-square test for independence of variables.

Findings & Value added: Customers behave according to the presented message in communication tools, which they believe. Therefore, it is possible to use communication tools on the way of recipient behaviour cultivation. The main objective of the paper is to find a connection between marketing communication tools and customer behaviour within food products after the declared consumption date. For evaluation, there were used five variables of customer behaviour with food, and seven chosen marketing communication tools. From 35 possible connections, we found out dependencies for ten relations.
Dumping – Unfair Trade Practice
Authors: Serences Roman , Kozelova Dagmar
Published: January 2021

Research background:The Globalisation gradually has removed the protection that has existed to protect producers against unfair trade practices. Existence of imperfect competition within an international trade is presented by descending curve of average costs while increasing economies of scale; it often leads some producers not to adjust the price in relation to the marker. In this case, we speak about dumping.

Purpose of the article:The article deals with dumping issue – an unfair trade practice analysing EU trade policy including antidumping, related Slovak legislation, price discrimination and dumping model.

Methods:From a methodological point of view, the article is divided into four parts; description of trade policy, antidumping and its legislation, price discrimination and dumping model. Methods of synthesis, critical thinking and graphical analysis were used.

Findings & Value added:In practice, accounting of different prices to the various consumers is called a price discrimination. The most common type of price discrimination in foreign trade is a dumping. It is a price practice when a company accounts lower price for exported goods compared to the same goods sale at home. World Trade Organization (WTO) allow counter such injury via trade defence instruments (TDIs). The EU TDIs are appropriate to tackle new challenges to international trade, because the Commission had done to modernise the EU’s basic Anti-Dumping (AD) Regulations.
The Importance of Irrational Purchasing Behaviour in Applying the Marketing Strategy of Selected Global Brands
Authors: Vrtana David
Published: January 2021

Research background:The progress of business activity depends on current trends in customer shopping behavior in a global environment. The current trend is also becoming a factor of irrationality, which enters the process of purchasing behavior. It is supported by the emotions and desires of consumers. In this sense, it is important to understand the irrational behavior of customers and respect the individual behavioral characteristics in the sales process. By respecting these characteristics, a company can strengthen its brand and marketing strategy with a view to gaining a global competitive advantage. Research will highlight the importance of irrational customer behaviour between the global Lindt and Hershey brands. We will find out whether the pricing policy and the discount are important for influencing shopping behaviour.

Purpose of the article:In the article, we pointed out the importance of behavioral characteristics of irrational shopping behaviour in the above-mentioned global brands. We will confirm whether the research of Dr. Ariely and despite the current trends, irrationality prevails in shopping behaviour in the environment of Slovak customers.

Methods:In order to assess the theoretical assumptions of behavioral economics and irrational shopping behavior, we used methods of analysis, synthesis. In the analytical part of the article, we also used the method of sociological questioning in order to ensure the credibility of the entire research. In the discussion part of the article, we used the method of induction.

Findings & Value added:Pointing out the importance and connection of irrational purchasing behavior in the application of the company’s marketing strategy in a global market environment.
Municipalities’ own revenue as an instrument for financial independence
Authors: Aleksandrova Valentina , Krasteva Nadezhda , Kresnaliyska Gergana , Petrova Yoana , Baldzhiev Petar
Published: January 2021

Research background: The article presents an analysis of the trends relating to the relation of the own income of municipalities and the received from the state budget financial resources compared with other countries which are chosen according to their form of state organization, as well as the financial relations of the municipal budget and the state budget, the budgetary relations and the applied fiscal rules.

Purpose of the article: The topicality of the issues connected with the financial decentralization of municipalities and the existing problems is indisputable, as the analysis and the assessment of the financial independence of municipalities are made according to a basic index – their own income. The main problem that is connected with the independence of municipalities - lack of enough own income requires the exertion of serious efforts so that the financially weaker and local communities are protected. The globalization and the free movement of people have an adverse effect on the own income of the municipalities in the country because of their depopulation and to a large extent, they depend on the state subsidies and transfers which seriously limits their independence.

Methods: The methods of analysis include a comparative one and an analysis of the constitutional and legal organization of municipal budgets in Bulgaria as well as an analysis of the structure of their own income.

Findings & Value added: The analysis allows us to make suggestions about legal changes and recommendations for more useful budgetary relations between the municipal budgets and the state budget.
Vine growing and production in global context
Authors: Navrátilová Miroslava , Brož David , Beranová Markéta
Published: January 2021

Research background: The global agri-food complex changed in last years. From global scale point of view agri-food complex must face new challenges in the field of changes of natural conditions and in the field of social and trade relations. Vine growing is due to the specific demands on its production is a suitable representative of these global changes.

Purpose of the article: The aim of this paper is to investigate relationship between area of vineyards and its production in context of globalization.

Methods: Secondary data were obtained from official information sources. From the point of view of the methodological apparatus, the analysis of time series were used. Based on the selection of a suitable trend function were forecasted following two period. Furthermore, modifications to the data matrix were made. For individual variables, which were compared using appropriate statistical methods. The growth coefficient was determined. The relationship between the variables was investigated.

Findings & Value added: Based on the data, there is an obvious degressive trend in vineyards, which could be caused by the European Union standard for maximum planting up to 2 % per year. Wine production fluctuates significantly during monitoring and it is very difficult to determine its trend. In the last decade, there is possible to see an increasing of wine consumption. In future research, the relationship between consumption and production, or the production and overall performance of agriculture as a sector, may be examined.
Community tourism – Development of rural areas in developing countries
Authors: Nova Monika
Published: January 2021

Research background: Community-based tourism has become a very popular form of sustainable tourism in the world. Tourism is supposed to be developmental in nature benefiting the local community by improving the Quality-of-Life and the standard of living for locals and local commerce. It is therefore imperative to understand that the community around tourism development is important and has to be involved in the development from the initial planning of the development as the sole beneficiaries of the development.

Purpose of the article: The aim of this work was to evaluate the prerequisites for the development of community-based tourism and Bridging the technology gap for community-based tourism projects in Cambodia.

Methods: The theoretical part is focused especially on community-based tourism, its origin, history and possibilities of development. The practical part of the thesis consists of a descriptive part which characterizes the studied area from the point of view of living conditions and tourism, and, also, contains the results of analysis of interviews conducted conditions and tourism, and, also, contains the results of analysis of interviews conducted with the local people and person by the implementer during the stay in the Cambodia were analysed using the Grounded theory method.

Findings & Value added: The result of the paper is to set the prerequisites for the development of community-based tourism and recommendations for a subsequent research.
Migration Challenges of the Current Stage of Globalization
Authors: Privara Andrej , Rievajova Eva
Published: January 2021

Research background: International labor migration is much less globalized than the other components of this process, mainly due to the various restrictions it continually encounters. Usually, the globalization of international migration results in complex migration systems. The migration challenges of the current stage of globalization include, among other things, changes in the categories of present migrants. The profile of migrants is becoming more and more diversified. It comprises women, minors, skilled people, entrepreneurs, and a low-skilled workforce or one who accepts a strong degree of disqualification.

Purpose of the article: The purpose of the paper is to identify processes of labor migration in the conditions of globalization, to analyze changes in the characteristics of migrants, as well as the paradox of complementarity between migration and globalization.

Methods: The authors used the methods of theoretical and empirical analysis. In addition to standard methods of theoretical analysis, they also used content analysis of text documents, mostly of an official nature. These were mainly national and European papers dealing with the issue of international labor migration in the context of globalization. Empirical research is based on the analysis of official data obtained from databases of international institutions (Eurostat, OECD, IOM, etc.).

Findings & Value added: As a result of the analysis, the authors concluded about adequate European immigration policy and greater labor mobility would contribute to addressing labor market imbalances. At the end of the article, the authors also formulated specific measures to support mobility within the EU.
Globalization, fiscal policy and free competition: The impact in EU
Authors: Anjos Maria do Rosário
Published: January 2021

Research background:Globalization has profoundly changed the rules of play in the international economy. A new world order, new challenges and new difficulties have arisen as well new strategies to avoid the consequences of global free competition. Fiscal policy is a crucial tool in new global competition model, in special for regions with a high level of economic integration, as EU. In this context tax harmonization is extremely important to prevent distortions of competition in European market.

Purpose of the article:Study the political and institutional constraints of the tax harmonization and disclosure a small part of the initial results of a investigation project about “tax competition in EU”. Understand if and how lack of tax harmonization between the member states is one of the causes of inequity between them, in special the Euro zone countries.

Methods:Comparative study about income tax’s in Euro zone countries and the relation to PIB, as well the deductive method to analyse the results we find and some reference studies on the subject.

Findings & Value added:The goal is answer to the follow questions: what are the political and institutional limitations to tax harmonization in EU? Why there are no further progress in the field of tax harmonization? Can EU and Euro zone survive face a globalization challenge with the present fiscal disloyal competition between member states? What future for EU in a globalization era? Findings show that tax harmonization never was considered as a priority in EU, and maybe never will, what is a weakness in a globalization world.
Are the Industry Cycles the Global Trend in Investment Activity?
Authors: Ivanov Viktor , Lvova Nadezhda , Abramishvili Neli , Pokrovskaia Natalia
Published: January 2021

Research background:According to the concept of sector rotation, industry cycles affect the investment attractiveness of companies. Industry cycles relate to business ones, and specific industries are preferred for investors depending on the phase of the latter. The scope of this concept application is portfolio investment management. However, we use it in a new way, assuming that the unfavourable phase leads to a decrease in the investment activity of companies in the corresponding industry.

Purpose of the article:Since the concept of sector rotation claims universality, we reveal if the industry cycles are the global trend in investment activity. The research purpose is to test the hypothesis of an industry cycles’ impact on the dynamics of the investment activity in companies obtaining external financing.

Methods:Using the concept of sector rotation, we suggest several industry groups and tested whether the peak of investment activity in each group falls on the expected favourable phase of the business cycle. In the context of global investment trends, this hypothesis should be confirmed at public companies of any sufficiently large financial market. For testing, Russian companies were selected. The growth rate of capital investments was used as an indicator of investment activity.

Findings & Value added:It was revealed that the hypothesis about the impact of industry cycles on the investment activity of a business has the potential for further research. However, there is no sufficient evidence to consider the orientation of the investment behaviour of companies on industry cycles as a global trend.
Czech Automotive Exports in the Context of the Global Economic Downturn from the Perspective of Statistics
Authors: Hašková Simona
Published: January 2021

Research background:The global outbreak of the COVID-19 and, as a result, the measures taken fundamentally disrupted the lives of people and economies. Private and public demand, industrial production, supply chains, etc. were affected. Given the severity of these shock changes, it is clear that the European Union will have experienced a severe economic recession.

Purpose of the article:Economists have long pointed to the Czech economy’s strong dependence on the automotive industry. Carmakers and a number of companies connected to them have been chained into existential difficulties after COVID-19 outbreak. However, the scenario of redirecting the industry is not real.

Methods:The article maps the declines in the forecast of GDP development in 2020 and 2021 in selected EU countries and statistically evaluates the historical dependence of Czech exports on German car production.

Findings & Value added:According to predictions, the Czech Republic expects the highest negative deviations in comparison with other EU countries. Reality will show what role a strong dependence on the automotive industry plays in this. The results of the statistics of the previous decade do not confirm the fundamental dependence of Czech exports on German automobile production. As the results indicate, Czech exporters are already diversifying at least in the sense of the target markets. The author raises the question whether the concept of public belief in the importance of supporting Czech carmakers as important producers of GDP on the export side can be the result of a strong lobbying by carmakers.
An Analysis of Correlation and Forecast of CZK to EUR in the Unstable Global World
Authors: Kalinová Eva , Rowland Zuzana
Published: January 2021

Research background: In the Czech Republic, the CZK/EUR currency pair is the most observed one not only by Czech consumers but also by Czech and foreign companies. Not only the political situation in the world and the foreign investors but also other variables have a significant influence on the CZK.

Purpose of the article: The aim of this paper is to analyse the development of the CZK/EUR exchange rate, to perform a correlation analysis of the CZK/EUR currency pair and to forecast its future development in today’s unstable global world affected by the Coronavirus pandemics.

Methods: In order to fulfil the aim of the paper, the data of the CZK/EUR currency pair from the beginning of the year 1999 to mid-June 2020 was used. The correlation analysis and the forecast of the future development of the exchange rate are performed by means of the, in today’s globalized world very promising, technology of artificial neural networks.

Findings & Value added: The analysis and the forecast of the exchange rate development is based on the time series model taking the previous value of the exchange rate and its previous volatility into consideration. The strongest propulsion power for the development of the CZK/EUR exchange rate will be the market atmosphere on the world’s markets and the associated capital transfer between risk assets and safe havens. Provided, that the current situation settled down definitively and the economy returned back to its normal state, it is probable that the Czech koruna would gain some part of its significant loss back within a medium-term period.
Global Position of the US Economy and Its Impact on the Economy of the Czech Republic
Authors: Pudilová Linda , Veselá Kamila
Published: January 2021

Research background: The economy with the strongest influence on world affairs, international politics and world economy is undoubtedly the economy of the United States of America. In the Czech Republic, after the revolution, the USA quickly came to the forefront of interest and mutual foreign trade grew significantly. However, their global influence was significantly reflected not only in economic aspects, but also in sociological aspects. In recent years, the so-called “Americanization” has been taking place in the Czech Republic. American terms were often adopted in the commonly used Czech language, and the demand for American goods increased significantly.

Purpose of the article: The objective of the presented text is to evaluate development of the influence of the USA on the economy of the Czech Republic by analysing the development of key macroeconomic quantities, in particular gross domestic product, gross national product, balance of payments and foreign trade. Based on the results of this analysis, the future development of the Czech economy, more precisely opportunities and impacts arising from mutual trade relations between the American and Czech economies, is predicated.

Methods: Descriptive statistic.

Findings & Value added: The results of the research showed a gradual expansion of the influence of the American economy in the Czech Republic, which began after 1989 and continues to this day. This influence manifested itself in several aspects. It was reflected in the structure of mutual foreign trade, and also in the Czech culture and the Czech language (adoption of English terms into the Czech language).
The further potential of mutual trade is highlighted out by comparing the structure of export and import from the USA in total and export and import from the USA to the Czech Republic.
Impact of Export Trade Promotion Organizations on Export Development in Latvia in the Context of Globalization
Authors: Veinbergs Vilnis , Skadina Helena
Published: January 2021

Research background:The impact of globalization in the 21st century is increasingly bringing change in the world’s political, economic, social and technological processes. It has become much easier to get information about relevant events across the borders, which lead to the visibility and accessibility of international business environment. International organizations promote and encourage small countries in the same manner as large ones in order to integrate them into the world’s economic development. As a result, most countries become partners and benefit through this globalization process which can be seen as a triggering factor for a successful cross-border trade.

Purpose of the article:This paper aims to analyse the impact of Trade Promotion Organizations (TPO) on business in Latvia and its usefulness for export activities as well as contribution of TPO program to GDP growth in Latvia in the period from 2004 to 2019.

Methods:In this research authors have used a case study method and analysed the experience of TPO in the global trade environment. Secondary data were obtained from statistical databases and research literature; regulations of international organizations in relevant countries - from publicly available sources.

Findings & Value added: Results of this research indicate that organizations which promote and support Latvian export positively influence activities and high-quality cooperation with exporting companies and entrepreneurs who want to trade abroad. At the end of the research, the authors summarize their findings about TPO’s support activities to exporters in Latvia and other countries.
Sildenafilo: Prevalencia y factores asociados a su consumo en estudiantes universitarios
Authors: Vargas Rodríguez Ledmar Jovanny , Niño Avendaño Carlos Alberto , Tristancho Pedro Felipe
Published: January 2021

Objetivo Determinar la prevalencia y los factores asociados al consumo de sildenafilo en estudiantes universitarios.

Métodos Se realizó un estudio observacional analítico, en estudiantes de la Facultad de Ciencias de la Salud de Instituciones de Educación Superior del municipio de Tunja. La variable dependiente fue el consumo de sildenafilo, las variables independientes fueron: edad, semestre, universidad, estrato, procedencia, pareja estable, actividad sexual actual, actividad física, inicio de las relaciones sexuales, uso de métodos de barrera, asesoría en planificación y disfunción eréctil.

Resultados La prevalencia de consumo de sildenafilo en universitarios fue del 19,25%. Los factores que aumentan el riesgo de consumo son: tener pareja estable, actividad sexual actual, inicio de relaciones sexuales antes de los 14 años y la presencia de disfunción eréctil; mientras se disminuye dicha probabilidad en: los primeros estratos socioeconómicos, no haber escuchado sobre el medicamento, asesoría del personal de salud, conocer las indicaciones, contraindicaciones, efectividad y reacciones adversas del medicamento.

Conclusiones Una quinta parte de los universitarios usan o han usado el sildenafilo. Casi el 80% de ellos han presentado efectos adversos. El consumo frecuente de ese fármaco amerita seguir estudiando esa población universitaria, puesto que no es usual que a esa edad se presente disfunción eréctil, para conllevar a la automedicación del sildenafil por lo tanto, esa conducta debe desencadenar intervenciones desde el área de bienestar universitario, específicamente médica para que se creen estrategias de intervención que apunten a una orientación de sexualidad responsable, y prevenir su uso indiscriminado que puede llevar a riesgos demasiado graves para la salud tanto física como mental.
A Clinical Prognostic Scoring System for Neurocysticercosis
Authors: Marquez-Romero Juan Manuel , Huerta-Franco María Raquel , Soto-Cabrera Elizabeth , Espinoza-López Dulce Anabel , Orrego Héctor , Martínez-Jurado Elizabeth , Zermeño-Pöhls Fernando , Guerrero-Juárez Vicente
Published: January 2021

Objectives In patients with neurocysticercosis (NCC), an accurate risk prediction would allow a better therapeutic approach; however, there are currently no tools that can enhance the accuracy of risk prediction. We designed a prognostic scoring system to be used by neurologists and other physicians managing patients with NCC.

Materials and Methods Using data from clinical records of patients from a third-level national reference center for neurological diseases, we assessed demographic, clinical, and tomographic variables among 293 patients diagnosed with NCC. Multivariable logistic regression analyses were used to develop a clinical prognostic scoring instrument. Patients with NCC were assessed for neurological impairment at 3 months after diagnosis.

Statistical Analysis Score accuracy was assessed by receiver operating characteristic (ROC) curve analysis. The primary outcome was the presence of neurological impairment, resulting in disability according to self-report or caregiver reports; this outcome was assessed during follow-up visits at 3 ± 1 months after discharge.

Results The most common symptoms at presentation were headache (67%) and seizure (63%). A six-item (total score from –4 to + 2) prognostic instrument was constructed on the basis of the presence of seizures/headache at presentation, a leukocyte count above 12x 109/dL, the presence of six to ten parasites, subarachnoid localization, and the use of anthelmintic drugs. Among 113 patients with negative scores, 79.6% developed neurological deficits. Among patients with scores of 1 to 2, 64.6% recovered completely, with an overall accuracy of prediction of 74.7% and area under the ROC curve = 0.722 (95% CI, 0.664–0.780, p < 0.0001).

Conclusions The clinical prognostic scoring system for NCC described in this study is a new instrument for use in daily clinical practice. It is simple to administer, and it has a prognostic accuracy of 75%. Its use has the potential to improve the quality of care by guiding appropriate decision-making and early management of patients with NCC.
Use of Hausdorff Distance and Computer Modelling to Evaluate Virtual Surgical Plans with Three-Dimensional Printed Guides against Freehand Techniques for Navicular Bone Repair in Equine Orthopaedics
Authors: Biedrzycki Adam H. , Kistler Hannah C. , Perez-Jimenez Erik E. , Morton Alison J.
Published: January 2021

Objective The aim of this study was to evaluate the surgical execution of a virtual surgical plan (VSP) with three-dimensional (3D) guides against a freehand approach in the equine navicular bone using an automated in silico computer analysis technique.

Study Design Eight pairs of cadaveric forelimb specimens of adult horses were used in an ex vivo experimental study design with in silico modelling. Limbs received either a 3.5 mm cortical screw according to a VSP or using an aiming device. Using computed tomography and computer segmentation, a comparison was made between the executed screw and the planned screw using the Hausdorff distance (HD).

Results Navicular bone mean HD registration error was –0.06 ± 0.29 mm. The VSP with 3D printing demonstrated significantly superior accuracy with a mean deviation of 1.19 ± 0.42 mm compared with aiming device group (3.53 ± 1.24 mm, p = 0.0018). The VSP group was 5.0 times more likely to result in a mean aberration of less than 1.0 mm (95% confidence interval, 0.62–33.4). A 3.5 mm screw with an optimal entry point can have a maximum deviation angle of 3.23 ± 0.07, 2.70 ± 0.06 and 2.37 ± 0.10 degrees in a proximal, dorsal and palmar direction respectively, prior to violating one of the cortical surfaces.

Conclusion Procedures performed using the 3D guides have a high degree of accuracy, with minimal mean deviations (<1 mm and <1 degree) of a VSP compared with those using the conventional aiming device. The use of VSP and the HD for evaluation of orthopaedic surgeries and outcome measures shows promise for simplifying and improving surgical accuracy.
Laser-induced electron diffraction of the ultrafast umbrella motion in ammonia
Authors: Belsa B. , Amini K. , Liu X. , Sanchez A. , Steinle T. , Steinmetzer J. , Le A. T. , Moshammer R. , Pfeifer T. , Ullrich J. , Moszynski R. , Lin C. D. , Gräfe S. , Biegert J.
Published: January 2021

Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table-top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH3) following its strong-field ionization. Upon ionization of a neutral ammonia molecule, the ammonia cation (NH3+) undergoes an ultrafast geometrical transformation from a pyramidal (ΦHNH=107°) to planar (ΦHNH=120°) structure in approximately 8 femtoseconds. Using LIED, we retrieve a near-planar (ΦHNH=117 ± 5°) field-dressed NH3+ molecular structure 7.8−9.8 femtoseconds after ionization. Our measured field-dressed NH3+ structure is in excellent agreement with our calculated equilibrium field-dressed structure using quantum chemical ab initio calculations.
Carrier-specific dynamics in 2H-MoTe2 observed by femtosecond soft x-ray absorption spectroscopy using an x-ray free-electron laser
Authors: Britz Alexander , Attar Andrew R. , Zhang Xiang , Chang Hung-Tzu , Nyby Clara , Krishnamoorthy Aravind , Park Sang Han , Kwon Soonnam , Kim Minseok , Nordlund Dennis , Sainio Sami , Heinz Tony F. , Leone Stephen R. , Lindenberg Aaron M. , Nakano Aiichiro , Ajayan Pulickel , Vashishta Priya , Fritz David , Lin Ming-Fu , Bergmann Uwe
Published: January 2021

Femtosecond carrier dynamics in layered 2H-MoTe2 semiconductor crystals have been investigated using soft x-ray transient absorption spectroscopy at the x-ray free-electron laser (XFEL) of the Pohang Accelerator Laboratory. Following above-bandgap optical excitation of 2H-MoTe2, the photoexcited hole distribution is directly probed via short-lived transitions from the Te 3d5/2 core level (M5-edge, 572–577 eV) to transiently unoccupied states in the valence band. The optically excited electrons are separately probed via the reduced absorption probability at the Te M5-edge involving partially occupied states of the conduction band. A 400 ± 110 fs delay is observed between this transient electron signal near the conduction band minimum compared to higher-lying states within the conduction band, which we assign to hot electron relaxation. Additionally, the transient absorption signals below and above the Te M5 edge, assigned to photoexcited holes and electrons, respectively, are observed to decay concomitantly on a 1–2 ps timescale, which is interpreted as electron–hole recombination. The present work provides a benchmark for applications of XFELs for soft x-ray absorption studies of carrier-specific dynamics in semiconductors, and future opportunities enabled by this method are discussed.
Experimental investigation on tip-vortex flow characteristics of novel bionic multi-tip winglet configurations
Authors: Hui Zhe , Cheng Gui , Chen Gang
Published: January 2021

Five bionic multi-tip winglet configurations, inspired by basic feather shapes and wingtip postures of birds, were designed to suppress the tip-vortex structures around their wingtips. Each of the bionic multi-tip winglet configurations consists of multiple novel feather-shaped winglets and looks like a dihedral (or non-planar) wingtip shape. The influence of the distribution density and chord-directional gap for the feather-shaped winglets on the tip-vortex flow characteristics was investigated experimentally at Re = 83 166. The results reveal that the vorticity levels of the tip-vortex structures in the near-wake region can achieve effective suppression by improving the feather-shaped winglets’ distribution density at the wingtip of the bionic wing configuration. The maximum proportions of the induced drag relative to the total drag for the bionic wing configurations I, II, and III are 25.54%, 21.05%, and 19.47%, respectively. The variation of the feather-shaped winglets’ distribution density significantly affects the lift–drag efficiency of the bionic wing configuration. However, the increase in the feather-shaped winglets’ mounting gap weakens the tip-vortex suppression effect for the bionic wing configuration (equipped with the three feather-shaped winglets) to some degree. The maximum proportions of the induced drag relative to the total drag for the bionic wing configurations IV and V are 27.28% and 28.32%, respectively. Compared with the bionic wing configuration I, the slightly worse aerodynamic performance for the bionic wing configurations IV or V (with the larger feather-shaped winglets’ mounting gap) is closely related to its weaker tip-vortex suppression ability.
Dietary chromium-methionine supplementation and broiler (22–43 days) responses during heat stress. 1. Growth performance and carcass yield, metabolisable energy and serum biochemistry
Authors: Santos Dalólio Felipe , Teixeira Albino Luiz Fernando , Nogueira da Silva Jadir , Kyonara Alves Tenório Fireman Alba , Burin Junior Álvaro Mário , Busanello Marcos , Ribeiro Júnior Valdir
Published: January 2021

Context Chromium (Cr) is considered a beneficial trace element. It has been reported that supplementation with Cr in the diet promotes improvements in the productive variables of broilers reared under heat stress (HS). Aim The study aimed to evaluate dose response of Cr as chromium-methionine (CrMet) supplementation on metabolisable energy, serum biochemistry, growth performance and carcass yield of broilers. Methods Three hundred and thirty-six 22-day-old male broiler chickens were randomly assigned to four blocks, six treatments (0, 0.10, 0.20, 0.40, 0.80 and 1.20 mg/kg dry matter (DM) Cr as CrMet), eight repetitions with seven birds per experimental unit, subjected to HS (33°C for 12h/day) from 22 to 43 days. The supplemented CrMet level for each variable studied was estimated using linear and quadratic regressions. Key results The bodyweight was quadratically affected at 35 and 43 days (P < 0.01), as well as bodyweight gain (P = 0.02) and feed conversion ratio (P = 0.01) from 22 to 43 days. A linear improvement (P = 0.03) was observed in the feed conversion ratio from 22 to 28 days and bodyweight gain for 22 to 35 days (P = 0.02). The nitrogen-corrected apparent metabolisable energy and the coefficient of metabolisation of energy were quadratically affected (P < 0.01 and P < 0.01, respectively) by CrMet levels in the diet. A quadratic response was observed on total serum cholesterol (P < 0.01), serum glucose (P = 0.07) and triacylglycerol (P < 0.01). The abdominal fat deposition was quadratically affected (P < 0.01) by CrMet levels in the diet. Conclusions The supplementation of 0.77 mg/kg DM Cr as CrMet improves performance, carcass characteristics and serum biochemistry parameters of broiler chickens reared under heat stress. Implications The results indicate that CrMet can be supplemented in the diet for broilers reared under heat stress to improve productivity of broiler chickens.
Thermal modulation of epicardial Ca2+ dynamics uncovers molecular mechanisms of Ca2+ alternans
Authors: Millet Jose , Aguilar-Sanchez Yuriana , Kornyeyev Dmytro , Bazmi Maedeh , Fainstein Diego , Copello Julio A. , Escobar Ariel L.
Published: January 2021

Ca2+ alternans (Ca-Alts) are alternating beat-to-beat changes in the amplitude of Ca2+ transients that frequently occur during tachycardia, ischemia, or hypothermia that can lead to sudden cardiac death. Ca-Alts appear to result from a variation in the amount of Ca2+ released from the sarcoplasmic reticulum (SR) between two consecutive heartbeats. This variable Ca2+ release has been attributed to the alternation of the action potential duration, delay in the recovery from inactivation of RYR Ca2+ release channel (RYR2), or an incomplete Ca2+ refilling of the SR. In all three cases, the RYR2 mobilizes less Ca2+ from the SR in an alternating manner, thereby generating an alternating profile of the Ca2+ transients. We used a new experimental approach, fluorescence local field optical mapping (FLOM), to record at the epicardial layer of an intact heart with subcellular resolution. In conjunction with a local cold finger, a series of images were recorded within an area where the local cooling induced a temperature gradient. Ca-Alts were larger in colder regions and occurred without changes in action potential duration. Analysis of the change in the enthalpy and Q10 of several kinetic processes defining intracellular Ca2+ dynamics indicated that the effects of temperature change on the relaxation of intracellular Ca2+ transients involved both passive and active mechanisms. The steep temperature dependency of Ca-Alts during tachycardia suggests Ca-Alts are generated by insufficient SERCA-mediated Ca2+ uptake into the SR. We found that Ca-Alts are heavily dependent on intra-SR Ca2+ and can be promoted through partial pharmacologic inhibition of SERCA2a. Finally, the FLOM experimental approach has the potential to help us understand how arrhythmogenesis correlates with the spatial distribution of metabolically impaired myocytes along the myocardium.
Key comparison BIPM.RI(I)-K3 of the air-kerma standards of the VNIIM, Russian Federation, and the BIPM in medium-energy x-rays
Authors: Burns D T , Kessler C , Villevalde A Y , Grishin D , Oborin A V
Published: January 2021

Main text

A key comparison has been made between the air-kerma standards of the VNIIM and the BIPM in the medium-energy x-ray range. The results show the standards to be in agreement at the level of the standard uncertainty of the comparison of 1.9 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Signal-recycled weak measurement for ultrasensitive velocity estimation*
Authors: Fang Sen-Zhi , Dai Yang , Jiang Qian-Wen , Tan Hua-Tang , Li Gao-Xiang , Wu Qing-Lin
Published: January 2021

Weak value amplification has shown its superiority in measurement of small physical effects. Here we introduce a signal-recycled weak-value-based velocity measurement strategy to decrease the attenuation of detected photons during the post-selection. Like the power-recycled scheme, we can improve the number of detected photons and signal-to-noise ratio of velocity by forming a cavity. However, optimal improvements of number of detected photons and signal-to-noise ratio cannot be obtained simultaneously in our signal-recycled scheme owing to the walk-off effect. Furthermore, we find that the reflected light is relatively strong compared with the power-recycled scheme, which may increase the collection-detection efficiency in prospective relevant experiment.
A rational design of bimetallic PdAu nanoflowers as efficient catalysts for methanol oxidation reaction*
Authors: Liu Jinyang , Wu Min , Yang Xinyi , Ding Juan , Lei Weiwei , Sui Yongming
Published: January 2021

Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants. Here, we developed a simple aqueous synthetic method to prepare bimetallic PdAu nanoflowers catalysts for methanol oxidation reaction (MOR) in alkaline environment. Their composition can be directly tuned by changing the ratio between Pd and Au precursors. Compared with commercial Pd/C catalyst, all of the PdAu nanoflowers catalysts show the enhanced catalytic activity and durability. In particular, the PdAu nanoflowers specific activity reached 0.72 mA/cm2, which is 14 times that of commercial Pd/C catalyst. The superior MOR activity could be attributed to the unique porous structure and the shift of the d-band center of Pd.
Practical decoy-state BB84 quantum key distribution with quantum memory*
Authors: Li Xian-Ke , Song Xiao-Qian , Guo Qi-Wei , Zhou Xing-Yu , Wang Qin
Published: January 2021

We generalize BB84 quantum key distribution (QKD) to the scenario where the receiver adopts a heralded quantum memory (QM). With the heralded QM, the valid dark count rate of the receiver’s single photon detectors can be mitigated obviously, which will lower the quantum bit error rate, and thus improve the performance of decoy-state BB84 QKD systems in long distance range. Simulation results show that, with practical experimental system parameters, decoy-state BB84 QKD with QM can exhibit performance comparable to that of without QM in short distance range, and exhibit performance better than that without QM in long distance range.
How quality improvement collaboratives work to improve healthcare in care homes: a realist evaluation
Authors: Devi Reena , Chadborn Neil H , Meyer Julienne , Banerjee Jay , Goodman Claire , Dening Tom , Gladman John R F , Hinsliff-Smith Kathryn , Long Annabelle , Usman Adeela , Housley Gemma , Lewis Sarah , Glover Matthew , Gage Heather , Logan Philippa A , Martin Finbarr C , Gordon Adam L
Published: January 2021

Background

Quality improvement collaboratives (QICs) bring together multidisciplinary teams in a structured process to improve care quality. How QICs can be used to support healthcare improvement in care homes is not fully understood.

Methods

A realist evaluation to develop and test a programme theory of how QICs work to improve healthcare in care homes. A multiple case study design considered implementation across 4 sites and 29 care homes. Observations, interviews and focus groups captured contexts and mechanisms operating within QICs. Data analysis classified emerging themes using context-mechanism-outcome configurations to explain how NHS and care home staff work together to design and implement improvement.

Results

QICs will be able to implement and iterate improvements in care homes where they have a broad and easily understandable remit; recruit staff with established partnership working between the NHS and care homes; use strategies to build relationships and minimise hierarchy; protect and pay for staff time; enable staff to implement improvements aligned with existing work; help members develop plans in manageable chunks through QI coaching; encourage QIC members to recruit multidisciplinary support through existing networks; facilitate meetings in care homes and use shared learning events to build multidisciplinary interventions stepwise. Teams did not use measurement for change, citing difficulties integrating this into pre-existing and QI-related workload.

Conclusions

These findings outline what needs to be in place for health and social care staff to work together to effect change. Further research needs to consider ways to work alongside staff to incorporate measurement for change into QI.
Blue flower coloration of Corydalis ambigua requires ferric ion and kaempferol glycoside
Authors: Yoshida Kumi , Oniduka Takeya , Oyama Kin-ichi , Kondo Tadao
Published: January 2021

Corydalis ambigua (Japanese name, Ezoengosaku) flowers bloom with blue to purplish petals in early spring in Hokkaido prefecture. In this study, a mechanism for blue petal coloration by ferric ions and keampferol glycoside was elucidated. Blue petals and cell sap exhibited similar visible (Vis) spectra, with λmax at approximately 600 nm and circular dichroism (CD) with positive exciton-type Cotton effects in the Vis region. Analysis of the organic components of the petals confirmed cyanidin 3-O-sambubioside and kaempferol 3-O-sambubioside as the major flavonoids. Mg, Al, and Fe were detected in petals using atomic emission spectroscopy. Color, Vis absorption, and CD consistent with those of blue petals were reproduced by mixing cyanidin 3-O-sambubioside, kaempferol 3-O-sambubioside, and Fe3+ in a buffered aqueous solution at pH 6.5. Both Fe3+ and flavonol were essential for blue coloration.
Biosynthetic pathways and enzymes involved in the production of phosphonic acid natural products
Authors: Shiraishi Taro , Kuzuyama Tomohisa
Published: January 2021

Phosphonates are organophosphorus compounds possessing a characteristic C−P bond in which phosphorus is directly bonded to carbon. As phosphonates mimic the phosphates and carboxylates of biological molecules to potentially inhibit metabolic enzymes, they could be lead compounds for the development of a variety of drugs. Fosfomycin (FM) is a representative phosphonate natural product that is widely used as an antibacterial drug. Here, we review the biosynthesis of FM, which includes a recent breakthrough to find a missing link in the biosynthetic pathway that had been a mystery for a quarter-century. In addition, we describe the genome mining of phosphonate natural products using the biosynthetic gene encoding an enzyme that catalyzes C–P bond formation. We also introduce the chemoenzymatic synthesis of phosphonate derivatives. These studies expand the repertoires of phosphonates and the related biosynthetic machinery. This review mainly covers the years 2012-2020.