bluuebunny/crossref_metadata_2025 huggingface dataset:
Exact Branch-Price-and-Cut for a Hospital Therapist Scheduling Problem with Flexible Service Locations and Time-Dependent Location Capacity
Authors: Jungwirth Alexander , Desaulniers Guy , Frey Markus , Kolisch Rainer
Published: November 2021

We study a new variant of the vehicle routing problem, which arises in hospital-wide scheduling of physical therapists. Multiple service locations exist for patients, and resource synchronization for the location capacities is required as only a limited number of patients can be treated at one location at a time. Additionally, operations synchronization between treatments is required as precedence relations exist. We develop an innovative exact branch-price-and-cut algorithm including two approaches targeting the synchronization constraints (1) based on branching on time windows and (2) based on adding combinatorial Benders cuts. We optimally solve realistic hospital instances with up to 120 treatments and find that branching on time windows performs better than adding cutting planes.

Summary of Contribution: We present an exact branch-price-and-cut (BPC) algorithm for the therapist scheduling and routing problem (ThSRP), a daily planning problem arising at almost every hospital. The difficulty of this problem stems from its inherent structure that features routing and scheduling while considering multiple possible service locations with time-dependent location capacities. We model the ThSRP as a vehicle routing problem with time windows and flexible delivery locations and synchronization constraints, which are properties relevant to other vehicle routing problem variants as well. In our computational study, we show that the proposed exact BPC algorithm is capable of solving realistic hospital instances and can, thus, be used by hospital planners to derive better schedules with less manual work. Moreover, we show that time window branching can be a valid alternative to cutting planes when addressing synchronization constraints in a BPC algorithm.
Prescriptive Analytics in Urban Policing Operations
Authors: Brandt Tobias , Dlugosch Oliver , Abdelwahed Ayman , van den Berg Pieter L. , Neumann Dirk
Published: November 2021

Problem definition: We consider the case of prescriptive policing, that is, the data-driven assignment of police cars to different areas of a city. We analyze key problems with respect to prediction, optimization, and evaluation as well as trade-offs between different quality measures and crime types. Academic/practical relevance: Data-driven prescriptive analytics is gaining substantial attention in operations management research, and effective policing is at the core of the operations of almost every city in the world. Given the vast amounts of data increasingly collected within smart city initiatives and the growing safety challenges faced by urban centers worldwide, our work provides novel insights on the development and evaluation of prescriptive analytics applications in an urban context. Methodology: We conduct a computational study using crime and auxiliary data on the city of San Francisco. We analyze both strong and weak prediction methods along with two optimization formulations representing the deterrence and response time impact of police vehicle allocations. We analyze trade-offs between these effects and between different crime types. Results: We find that even weaker prediction methods can produce Pareto-efficient outcomes with respect to deterrence and response time. We identify three different archetypes of combinations of prediction methods and optimization objectives that constitute the Pareto frontier among the configurations we analyze. Furthermore, optimizing for multiple crime types biases allocations in a way that generally decreases single-type performance along one outcome metric but can improve it along the other. Managerial implications: Although optimization integrating all relevant crime types is theoretically possible, it is practically challenging because each crime type requires a collectively consistent weight. We present a framework combining prediction and optimization for a subset of key crime types with exploring the impact on the remaining types to support implementation of operations-focused smart city solutions in practice.
1.79-Approximation Algorithms for Continuous Review Single-Sourcing Lost-Sales and Dual-Sourcing Inventory Models
Authors: Xin Linwei
Published: November 2021

Stochastic inventory systems with lead times are often challenging to optimize, including single-sourcing lost-sales and dual-sourcing systems. Recent numerical results suggest that capped policies demonstrate superior performance over existing heuristics. However, the superior performance lacks a theoretical foundation. In “1.79-Approximation Algorithms for Continuous Review Single-Sourcing Lost-Sales and Dual-Sourcing Inventory Models,” the author provides a theoretical foundation for this phenomenon in two classical inventory models. First, in a continuous review lost-sales model with lead times and Poisson demand, he proves that a capped base-stock policy has a worst-case performance guarantee of 1.79 by conducting an asymptotic analysis under a large penalty cost and lead time. Second, in a more complex continuous review dual-sourcing model with general lead times and Poisson demand, he proves that a similar capped dual-index policy has a worst-case performance guarantee of 1.79 under large lead time and ordering cost differences. The results provide a deeper understanding of the superior numerical performance of capped policies and present a new approach to proving worst-case performance guarantees of simple policies in hard inventory problems.
SECURITY AND SAFETY OF TOURISTS AS A FACTOR FOR SUSTAINABLE TOURISM, BASED ON THE EXAMPLE OF BULGARIAN BLACK SEA RESORTS
Authors: Georgieva Daniela V. , Bankova Diyana
Published: November 2021

Different types of crimes are factors negatively affecting tourism worldwide. However, managers and even tourists themselves are refraining from submitting crime reports and whistleblows. The main goal of the study is to analyze the attitude of the hotels’ managers on the Bulgarian Black Sea coast, regarding the submission of whistleblows to the competent authorities. In particular, managers of hotels in Albena, Golden Sands, Dunes, St. Constantine and Helena, and Sunny Beach are studied. The main research hypothesis is that hotel managers should ensure the safety of guests by reducing gaps in the control environment, preventing financial frauds, helping for environmental protection, and supporting the process of reporting crimes and suspicious behavior in the hotels. However, the current management policy relies mainly on the installed security devices and the Security Department staff. This results in applying no specific internal rules, procedures, and training for non-security department employees, regarding crime identification and timely reporting. The adopted research methods are based on the logical, deductive, and comparative methods, as well as on the methods of analysis and synthesis. For the empirical study, the method of in-depth interviews is used. The results of the study support the literature by presenting more in-depth data regarding the used security devices and assets by Bulgarian Black Sea resort hotels. Also, more data on the attitude of hotel managers on the safety and security of tourists and the submission of whistleblows, as a factor for sustainable development of tourism on the Bulgarian Black Sea coast, is presented.
OBSTACLES OF ORGANIZATIONAL DEVELOPMENT - ANALYSIS OF OBSTACLES AND NECESSARY COMPETENCIES AND METHODS FOR SUCCESSFUL IMPLEMENTATION
Authors: Weigold Andrea
Published: November 2021

In order to keep up with the new requirements of a market or a business environment, organizational developments are a necessary change to align the company with the future. Every change in the company is associated with various obstacles, ranging from the difference between the current and the new business model to the employees' acceptance of the organizational development. In order to follow the new vision of the company, structured and extensive communication and structured planning of the implementation is required, in which every stakeholder has to be involved. The change that the organization implements must be accompanied by methods and models and thus learn in the development phase how to avoid obstacles and rejection to arouse motivation and interest so that uncertainties are prevented. Different methods are listed and evaluated in their implementation and content for a possibility for the change. The main focus is on the employees because without the acceptance of the most important stakeholders in a company, no further development is possible. If the employees do not support the vision, the change will fail. In order to accompany a successful development of the company, some necessary competencies and skills are listed, which are to be imparted by the company management and which the employee must acquire. This structured and modeled procedure is intended to accompany and enable change in a company.
OPTIMIZING MOLECULAR DOCKING PROTOCOLS OF PYRROLE CONTAINING MAO-B INHIBITORS THROUGH CORRELATION COEFFICIENTS
Authors: Mateev Emilio , Valkova Iva , Tzankova Diana , Georgieva Maya , Zlatkov Alexander
Published: November 2021

Virtual screening is emerging as a highly applied technique for the search of hits since it significantly reduces the time required for the establishment of novel, effective compounds compared to high-throughput screening. Implementing correlation coefficients to determine if a molecular docking study is robust and reliable has been established as common practice in recent years. The aim of this work was to determine if a relevant pairwise correlation between the scoring functions (ChemPLP, GoldScore, Chemscore and ASP) of the docking software GOLD 5.2 and previously determined experimental data of pyrrole derivatives with MAO-B inhibitory activity could be achieved. In order to optimize the correlation coefficient, we calculated the Pearson’s and Spearman’s coefficients after each docking simulation with all four GOLD 5.2 scoring functions. Thereafter, we varied three changeable parameters – the size of the grid space, the side-chain flexibility and the presence of water molecules in the active site, to perceive if we could obtain better correlation values. The highest R2=0.79 was attained with the following docking settings: scoring function ChemPLP, grid size 12Å and no rotatable side chain residues. This work provides an applicable GOLD 5.2 docking protocol for a future virtual screening of novel MAO-B inhibitors with pyrrole moiety.
BIG DATA AND DECISION-MAKING SUPPORT
Authors: Procházka Peter
Published: November 2021

INTRODUCTION: Nowadays, Big Data is created in previously unimaginable quantities. Newly generated data from various Internet of Things (IoT) sensors and their use have never reached their current dimensions. Along with this trend, the availability of devices capable of collecting this data increases, the time for their evaluation is reduced and the volume of data collected at the same time increases. The most important task of research and development in this area is to bring solutions suitable for processing large amounts of data because our current storage and processing capabilities are limited and unable to compete with the storage, processing and publication of the resulting data.

OBJECTIVES: Point out the importance of implementing Big Data technology.

METHODS: To achieve the goal, the following methodological approach was chosen: study and processing of foreign and domestic literature, acquaintance with similar solutions for data processing, definition of Big Data and IoT, proposal for using Big Data solution to support decision-making, risk definition and evaluation.

RESULTS: With the growing amount of disparate and incoherent data and the further growth of the Internet of Things, it is now almost impossible to evaluate all available information correctly and in a timely manner. Without this knowledge, the company loses its competitive advantage and is unable to respond in a timely manner to client requests.

CONCLUSION: Implementing a solution for processing Big Data to support decision-making in the company is a complex process. As part of the implementation and use of the Big Data solution to support decision-making, the company must be prepared for the emergence of various problems. We can assume that Big Data technology will constantly be evolving in terms of streamlining analytical tools for obtaining information from large volumes of generated data. Therefore, it is appropriate to create space for the implementation of Big Data technology.
LEGAL REGULATION OF SUPPORT TOOLS IN SOCIAL ECONOMY AND ITS INNOVATIONS IN THE PERIOD OF COVID-19 IN SLOVAK REPUBLIC
Authors: Gálisová Zuzana , Plavčan Peter
Published: November 2021

The 20ties of the 21st century are characterized by the pandemic period of COVID-19. The fall of national economies, the fears of inhabitants regarding their health, and the unfavorable economic situation of big groups of inhabitants require functional measures. Implementing social economy principles in national economies is a tool to improve the economic situation of the marginalized groups of inhabitants without using social networks. The knowledge on the social economy system and legal regulation of support tools in social economy in Slovak Republic enable the dissemination of this knowledge and potentially implement in the current pandemic COVID-19 period even in the international environment. The legal regulation of the social economy offers more support tools to solve current economic problems during the COVID-19 pandemic period. Here we present a structured overview and generalization of the knowledge of legal regulations on the social economy as well as a detailed description of the content of the support tools of the social economy during the COVID-19 period.
COMPETENCIES OF PHYSICAL EDUCATION TEACHERS IN CONDUCTING ONLINE EDUCATION
Authors: Ivanova Veselina , Mileva Eleonora
Published: November 2021

The state of emergency, as a result of the COVID-19 pandemic, has completely changed the education system in Bulgaria, including the training of physical education and sports in Bulgarian schools. Physical education and sports training have been transformed into distance and online education and training. The aim of the research was to study the competencies of PE teachers in the country for the implementation of online teaching. The subject of the study was a total of 138 teachers, of whom 100 (72.5%) were female and 38 (27.5%) were male. The teachers were aged from 24 to 68 years old, with different pedagogical experience and were representatives of all regions of the country. A specially developed international questionnaire with closed questions was applied. Alternative analysis and chi-square Pearson's test (×²) were used to analyze the results. The results show that the sampled teachers evaluated the current use of online education in physical education and sport as relatively good (47.1%). At the same time, the acquired results show that the educational activity of sports pedagogues during the pandemic has reduced their motivation for professional activity (43.5%). Teachers have rated as very good (29.7%) and good (45.7%) their competencies for using online technologies to conduct physical education and sports classes. The majority of them – 79%, actively applied the new technologies in the training process. No differences were found in the answers of the respondents to any of the questions on the criteria of gender, age and pedagogical experience.
CULTURAL-SOCIOLOGICAL CHANGE OF PARADIGMS IN SOCIAL WORK
Authors: Mareková Hermína
Published: November 2021

There is a lot of discussion about social work, its forms, and whether social work is needed. If so, then in its existing or a different form? Often, only subjective thoughts or practical experiences are presented. They are subjective because, by pointing out the unfavorable situation, they describe a certain unidentifiable barrier, a shortcoming in building this profession, which social work has not been able to overcome in the past long period. As if we were wasting our chances of change. The performance of social work still has a socialist flavor, and therefore the Western models adopted in our country since the end of 1980's have not met with legislative support. This situation was partly caused by the fact that we took over "a little of each corner", without complexity, as if the richer competencies remained somewhere at the border crossing between Kittsee and Bratislava. It is not possible to compare the beginnings of social care in our country, which began elsewhere in the world in the '30-'40s, because, for ideological reasons, there was a certain effort to discredit some issues, together with other deviant problems. These ideological motivations have already disappeared but were replaced by economic reasons, which continued to prevent social care from undergoing a change of opinion and structure. Evidence of these shortcomings is also the fact that no government has so far embarked on the creation of family social policy, as if this situation suited all actors. Within the EU, considerable financial support comes to the social area, but it disappears in the wallets of non-profit organizations, often without control, and that is why there is no such systematic change. Even very beneficial projects in various "non-profit" organizations work only until the allocated funds are spent, and after the expiration of the time required for the existence of the project by the EU, the project falls into oblivion, and those organizations often apply for a completely different project. Research data is missing for a systemic change. Without the available research data, we cannot even expect a change in paradigms, so we continue to lag behind the more developed part of the world in this area.
INTRODUCTION OF ELEMENTS FROM PROBABILITY THEORY IN THE EDUCATION IN MATHEMATICS FOR PRIMARY SCHOOL
Authors: Temnikova Maria
Published: November 2021

The article considers the prerequisites for the inclusion of problems with elements of probability theory in mathematics education in grades 1-4. This type of task is generally not present in the compulsory curriculum in mathematics in primary school, but they could be used in classes for compulsory, extended, and additional training, thus creating conditions for implementing developmental learning.

Some theoretical statements about the theory of probabilities are systematized, related to the tasks included in the constructed and approbated methodological system of work. Some of its characteristics are presented. This article offers some of the tasks for grades 1-4.

A longitudinal empirical study was conducted with students of the 1-4th grade in the period 2015 to 2020. The results of the outgoing diagnostics in 4th grade are processed by mathematical and statistical methods and are presented graphically. They show that fourth-graders successfully solve problems with elements of probability theory, and a primary school teacher could use them in the systematic work in mathematics at the initial stage of the basic educational degree.

Solving non-standard mathematical problems is an element of probability theory that helps arouse interest, motivate students, and place them in an active cognitive position by solving problem situations in the pedagogical interaction in mathematics in primary school.
The Attenuation Characteristics of the Body Tissue on Frequency Function in WBAN Channel
Authors: Mauludiyanto Achmad , Hendrantoro Gamantyo , Nova Muhammad Fachry
Published: November 2021

The Wireless Body Area Network (WBAN) refers to a communication network between sensors placed on the inside, on the surface, or around the body wirelessly. WBAN system cannot be separated from body tissues. Body tissues also have electrical properties depending on frequency. Therefore, body tissue can affect the phenomena occurring in radio wave propagation in the WBAN channel. One of the phenomena is attenuation. This study investigates the impacts of body tissue on the WBAN channel and the effects of frequency on the attenuation of body tissue in the WBAN channel. The measurement of magnitude response was carried out with the human body as the measurement object by utilizing the S21 parameter measurement with a vector network analyzer. In NLOS conditions, a human body was located between two coplanar Vivaldi antenna. Measurements were conducted on the head, chest, and abdomen. The frequency used was in the range of 2 GHz to 6 GHz. The body tissue attenuation was obtained by finding the difference between the magnitude measurement response on the LOS and NLOS conditions. The attenuation data were analyzed using statistical and numerical analysis to determine the effect of frequency on the attenuation of the human body tissues. Based on the analysis results, it was identified that the frequency affected the human body tissue attenuation. The enhancement attenuation of the human body tissues occurred when the frequency was higher. Moreover, there was a significant difference in the body tissue attenuation in different parts of the body.Keywords: attenuation, body tissues, s-parameters, wireless body area network.
CC-CV Controlled Fast Charging Using Fuzzy Type-2 for Battery Lithium-Ion
Authors: Falih Ahmad Zidan , Efendi Mohammad Zaenal , Murdianto Farid Dwi
Published: November 2021

Energy dependency is increasing along with the increase in population growth rate, while the fossil energy is decreasing. Alternative energy such as solar energy is one solution to provide renewable energy, but solar energy cannot provide an intense supply of energy. Therefore, the equipment needs an energy storage. The battery has important role in energy storage with the performance of the battery that need an attention. The method and type of battery used  must be considered to maintain battery lifetime and  reduce overcharging. The purpose of this research is to understand the process of fast charging the CC-CV (Constant Current Constant Voltage) method on Lithium-Ion battery which is expected to reduce battery overcharging. In this method, the current is maintained constant until certain conditions then followed by constant voltage to prevent overcharging. The voltage from the solar panel is very high, voltage reduction is needed as the charging voltage for the battery. The DC-DC Converter used is Buck Converter which is given Fuzzy Type-2 algorithm to maintain a current of 10 Ampere during CC conditions and  a voltage of 14.4 Volt during CV conditions with switch of CC conditions to CV conditions on SoC 99.25%.Keywords: battery charging, buck converter, CC-CV, lithium-ion, type-2 fuzzy.
Applying organisational behaviour theory to aid emergency staff retention
Authors: Montminy Nathaniel , Russell Eric J , Holley Steve
Published: November 2021

The purpose of this theoretical concept article is to spark a dialogue on the use of organisational behaviour theory to address emergency responder retention. In the United States, emergency medical services (EMS) appear to be burdened with continuing problems of retaining staff. Poor responder retention affects the ability of EMS to deliver high-quality services; without trained, educated and experienced first responders, the EMS system struggles, and what suffers is the ability to provide medical care. The authors set out to construct a pathway for addressing the underlying issues leading to the exodus of professionals using organisational behaviour theory. To develop the idea, an inductive logic approach was used to address underlying negative factors influencing poor retention and discuss the promise of organisational behaviour theory in improving the retention of responders.
Hip decompression combined with bone marrow concentrate and platelet-rich plasma for corticosteroid-induced osteonecrosis of the femoral head
Authors: Houdek Matthew T. , Wyles Cody C. , Smith John-Rudolph H. , Terzic Andre , Behfar Atta , Sierra Rafael J.
Published: November 2021

Aims

Bone marrow-derived mesenchymal stem cells obtained from bone marrow aspirate concentrate (BMAC) with platelet-rich plasma (PRP), has been used as an adjuvant to hip decompression. Early results have shown promise for hip preservation in patients with osteonecrosis (ON) of the femoral head. The purpose of the current study is to examine the mid-term outcome of this treatment in patients with precollapse corticosteroid-induced ON of the femoral head.

Methods

In all, 22 patients (35 hips; 11 males and 11 females) with precollapse corticosteroid-induced ON of the femoral head underwent hip decompression combined with BMAC and PRP. Mean age and BMI were 43 years (SD 12) and 31 kg/m² (SD 6), respectively, at the time of surgery. Survivorship free from femoral head collapse and total hip arthroplasty (THA) and risk factors for progression were evaluated at minimum five-years of clinical follow-up with a mean follow-up of seven years (5 to 8).

Results

Survivorship free from femoral head collapse and THA for any reason was 84% and 67% at seven years postoperatively, respectively. Risk factors for conversion to THA included a high preoperative modified Kerboul angle (grade 3 or 4) based on preoperative MRI (hazard ratio (HR) 3.96; p = 0.047) and corticosteroid use at the time of decompression (HR 4.15; p = 0.039). The seven-year survivorship for patients with grade 1 or 2 Kerboul angles for conversion to THA for articular collapse, and THA for any reason, were 96% and 72%, respectively, versus THA for articular collapse and THA for any reason in patients with grade 3 or 4 Kerboul angles of 40% (p = 0.003) and 40% (p = 0.032).

Conclusion

At seven years, hip decompression augmented with BMAC and PRP provided a 67% survivorship free from THA in patients with corticosteroid-induced ON. Ideal candidates for this procedure are patients with low preoperative Kerboul angles and can stop corticosteroid treatment prior to decompression. Cite this article: Bone Jt Open 2021;2(11):926–931.
Towards a portable-noninvasive blood pressure monitoring system utilizing the photoplethysmogram signal
Authors: Dagamseh Ahmad , Qananwah Qasem , Al Quran Hiam , Shaker Ibrahim Khalid
Published: November 2021

Blood pressure (BP) responds instantly to the body's conditions, such as movements, diseases or infections, and sudden excitation. Therefore, BP monitoring is a standard clinical measurement and is considered one of the fundamental health signs that assist in predicting and diagnosing several cardiovascular diseases. The traditional BP techniques (i.e. the cuff-based methods) only provide intermittent measurements over a certain period. Additionally, they cause turbulence in the blood flow, impeding the continuous BP monitoring, especially in emergency cases. In this study, an instrumentation system is designed to estimate BP noninvasively by measuring the PPG signal utilizing the optical technique. The photoplethysmogram (PPG) signals were measured and processed for ≈ 450 cases with different clinical conditions and irrespective of their health condition. A total of 13 features of the PPG signal were used to estimate the systolic and diastolic blood pressure (SBP and DBP), utilizing several machine learning techniques. The experimental results showed that the designed system is able to effectively describe the complex-embedded relationship between the features of the PPG signal and BP (SBP and DBP) with high accuracy. The mean absolute error (MAE) ± standard deviation (SD) was 4.82 ± 3.49 mmHg for the SBP and 1.37 ± 1.65 mmHg for the DBP, with a mean error (ME) of ≈ 0 mmHg. The estimation results are consistent with the Association for the American National Standards of the Association for the Advancement of Medical Instrumentation (AAMI) and achieved Grade A in the British Hypertension Society (BHS) standards for the DBP and Grade B for the SBP. Such a study effectively contributes to the scientific efforts targeting the promotion of the practical application for providing a portable-noninvasive instrumentation system for BP monitoring purposes. Once the BP is determined with sufficient accuracy, it can be utilized further in the early prediction and classification of various arrhythmias such as hypertension, tachycardia, bradycardia, and atrial fibrillation (as the early detection can be a critical issue).
Describing discontinuous finite 3D scattering objects in Gabor coefficients: fast and accurate methods
Authors: Eijsvogel S. , Sun L. , Sepehripour F. , Dilz R. J. , van Beurden M. C.
Published: November 2021

In relation to the computation of electromagnetic scattering in layered media by the Gabor-frame-based spatial spectral Maxwell solver, we present two methods to compute the Gabor coefficients of the transverse cross section of three-dimensional scattering objects with high accuracy and efficiency. The first method employs the analytically obtained two-dimensional Fourier transform of the cross section of a scattering object, which we describe by two-dimensional characteristic functions, in combination with the traditional discrete Gabor transform method for computing the Gabor coefficients. The second method concerns the expansion of the so-called dual window function to compute the Gabor coefficients by employing the divergence theorem. Both methods utilize (semi)-analytical approaches to overcome the heavy oversampling requirement of the traditional discrete Gabor transform method in the case of discontinuous functions. Numerical results show significant improvement in terms of accuracy and computation time for these two methods against the traditional discrete Gabor transform method.
Extended axial irradiances: Barker rings
Authors: Gómez-Sarabia Cristina M. , Sauceda-Carvajal Angel , Ledesma-Carrillo Luis M. , Torres-Cisneros Miguel , Ojeda-Castañeda Jorge
Published: November 2021

For extending focal depth we employ a set of transparent concentric rings, which are coded with the Barker sequences of length L. At the neighborhood of the paraxial focal plane, these transparent masks generate an axial uniform distribution, which is modulated with sinusoidal variations. For imaging applications, one can extend focal depth if the Barker length is congruent to unity modulo 4. And, for optical trapping, a bottle neck irradiance distribution is generated if the Barker length is congruent to three modulo 4.
Shockley-Queisser analysis of the temperature-efficiency correlation of solar cells in the presence of non-radiative heat transfer: erratum
Authors: Zhang Zheng , Chen Kaifeng , Fan Shanhui , Chen Zhen
Published: November 2021

This erratum corrects a typographical error in Fig. 2 of our published paper [Opt. Express 29, 27554 (2021)10.1364/OE.434751].
Direct modulation of electrically pumped coupled microring lasers
Authors: Xu Chi , Hayenga William E. , Christodoulides Demetrios N. , Khajavikhan Mercedeh , LiKamWa Patrick
Published: November 2021

We demonstrate how the presence of gain-loss contrast between two coupled identical resonators can be used as a new degree of freedom to enhance the modulation frequency response of laser diodes. An electrically pumped microring laser system with a bending radius of 50 μm is fabricated on an InAlGaAs/InP MQW p-i-n structure. The room temperature continuous wave (CW) laser threshold current of the device is 27 mA. By adjusting the ratio between the injection current levels in the two coupled microrings, our experimental results clearly show a bandwidth improvement by up to 1.63 times the fundamental resonant frequency of the individual device. This matches well with our rate equation simulation model.
Flame emission tomography based on finite element basis and adjustable mask
Authors: Liu Hecong , Wang Qian , Peng Fan , Qin Zhao , Cai Weiwei
Published: November 2021

Flame emission tomography is a promising tool for combustion diagnostics. Up to now, this technique relies on the assumption that the distribution within a voxel is uniform. Such an assumption suffers from a large gradient between adjacent voxels and the loss of information within the voxel. Hence, this work aims to develop a method based on the finite element basis to address the above shortcomings. From the reconstruction side, an adjustable mask is developed to suppress the artifacts and speed up reconstruction. Both simulative and experimental studies have been designed and conducted. The simulative results show that the finite element basis can decrease the reconstruction errors (defined as normalized 2-norm difference) from 0.616 to 0.241 and 0.386 to 0.203 by the algebraic reconstruction technique for two representative flame phantoms. The adjustable mask can decrease the reconstruction error for both bases, especially under low voxel resolution. The experimental results show that the predicted projection error of the finite element basis with the adjustable mask is decreased by 57% compared with that of the uniform voxel basis with the fixed mask when the voxel resolution is 16 × 16 × 20. Furthermore, the finite element basis can generate better reconstructions with fewer voxels. Both simulative and experimental studies suggested the superiority of the finite element basis with the adjustable mask.
Light-patterned fluorescent gold nanoclusters in polycarbonate films
Authors: Bitarafan Mohammad H. , Zhou Shaochen , Hänninen Jussi , Duan Yanyan , Leino Martti , Ras Robin H. A. , Toivonen Juha
Published: November 2021

Fluorescent metal nanoclusters embedded in rigid matrices are attractive for many applications, such as for use as light-emitting diodes and for optical data storage. Given the advantages of polycarbonate films, like high transparency and excellent toughness, the development of metal nanoclusters in these films could further enhance various applications. Herein, we fabricated fluorescent gold nanoclusters in a polycarbonate film using a photochemical process. The polymer film is doped with gold chloride and a photoinitiator and then irradiated by a light-emitting diode (365 nm), leading to the photoreduction of gold ions and the formation of bright fluorescent nanoclusters with a quantum yield of 15%. The as-formed nanoclusters display good photostability and retain their emission spectral shape over an extended period of time. These highly fluorescent structures have potential applications in the fabrication of authenticity markings and optoelectronic devices.
Diversity, taxonomy, and evolution of archaeal viruses of the class Caudoviricetes
Authors: Liu Ying , Demina Tatiana A. , Roux Simon , Aiewsakun Pakorn , Kazlauskas Darius , Simmonds Peter , Prangishvili David , Oksanen Hanna M. , Krupovic Mart
Published: November 2021

The archaeal tailed viruses (arTV), evolutionarily related to tailed double-stranded DNA (dsDNA) bacteriophages of the class Caudoviricetes, represent the most common isolates infecting halophilic archaea. Only a handful of these viruses have been genomically characterized, limiting our appreciation of their ecological impacts and evolution. Here, we present 37 new genomes of haloarchaeal tailed virus isolates, more than doubling the current number of sequenced arTVs. Analysis of all 63 available complete genomes of arTVs, which we propose to classify into 14 new families and 3 orders, suggests ancient divergence of archaeal and bacterial tailed viruses and points to an extensive sharing of genes involved in DNA metabolism and counterdefense mechanisms, illuminating common strategies of virus–host interactions with tailed bacteriophages. Coupling of the comparative genomics with the host range analysis on a broad panel of haloarchaeal species uncovered 4 distinct groups of viral tail fiber adhesins controlling the host range expansion. The survey of metagenomes using viral hallmark genes suggests that the global architecture of the arTV community is shaped through recurrent transfers between different biomes, including hypersaline, marine, and anoxic environments.
Identifying prognostic pairwise relationships among bacterial species in microbiome studies
Authors: Devlin Sean M. , Martin Axel , Ostrovnaya Irina
Published: November 2021

In recent literature, the human microbiome has been shown to have a major influence on human health. To investigate this impact, scientists study the composition and abundance of bacterial species, commonly using 16S rRNA gene sequencing, among patients with and without a disease or condition. Methods for such investigations to date have focused on the association between individual bacterium and an outcome, and higher-order pairwise relationships or interactions among bacteria are often avoided due to the substantial increase in dimension and the potential for spurious correlations. However, overlooking such relationships ignores the environment of the microbiome, where there is dynamic cooperation and competition among bacteria. We present a method for identifying and ranking pairs of bacteria that have a differential dichotomized relationship across outcomes. Our approach, implemented in an R package PairSeek, uses the stability selection framework with data-driven dichotomized forms of the pairwise relationships. We illustrate the properties of the proposed method using a published oral cancer data set and a simulation study.
Deciphering the molecular mechanism of the cancer formation by chromosome structural dynamics
Authors: Chu Xiakun , Wang Jin
Published: November 2021

Cancer reflects the dysregulation of the underlying gene network, which is strongly related to the 3D genome organization. Numerous efforts have been spent on experimental characterizations of the structural alterations in cancer genomes. However, there is still a lack of genomic structural-level understanding of the temporal dynamics for cancer initiation and progression. Here, we use a landscape-switching model to investigate the chromosome structural transition during the cancerization and reversion processes. We find that the chromosome undergoes a non-monotonic structural shape-changing pathway with initial expansion followed by compaction during both of these processes. Furthermore, our analysis reveals that the chromosome with a more expanding structure than those at both the normal and cancer cell during cancerization exhibits a sparse contact pattern, which shows significant structural similarity to the one at the embryonic stem cell in many aspects, including the trend of contact probability declining with the genomic distance, the global structural shape geometry and the spatial distribution of loci on the chromosome. In light of the intimate structure-function relationship at the chromosomal level, we further describe the cell state transition processes by the chromosome structural changes, suggesting an elevated cell stemness during the formation of the cancer cells. We show that cell cancerization and reversion are highly irreversible processes in terms of the chromosome structural transition pathways, spatial repositioning of chromosomal loci and hysteresis loop of contact evolution analysis. Our model draws a molecular-scale picture of cell cancerization from the chromosome structural perspective. The process contains initial reprogramming towards the stem cell followed by the differentiation towards the cancer cell, accompanied by an initial increase and subsequent decrease of the cell stemness.
Can core competence help reduce stock price synchronicity? - Empirical evidence based on text analysis
Authors: Sun Changling , Sun Hetao , Li Nian , Khan Muhammad Asif , Zhang Zixi
Published: November 2021

This paper constructs the measurement index of core competence by text analysis method and empirically tests the impact of core competence on stock price synchronicity. We find that the stronger the core competence, the lower the stock price synchronicity, and mechanism test shows that core competence reduces the stock price synchronicity by enhancing the transparency of corporate information, which is still valid under a series of robustness tests. Further research shows that:(1) when the corporate governance environment is poor (higher level of internal earnings management, lower quality of accounting information, greater separation of ownership and control, lower shareholding ratio of external institutional investors, weaker product market competition, less media attention), the core competence has a more significant effect on the decline of stock price synchronization; (2)vertically, the dynamic improvement of core competence in the time dimension can play a role in stabilizing stock price synchronization; (3)after distinguishing the types of core competence, we find that the core competence related to information disclosure is more helpful to reduce the stock price synchronization; (4)after the CSRC forces listed companies to disclose the core competence information in the annual report, the core competence plays a stronger role in reducing the stock price synchronization. This study reveals the important role of core competence in reducing stock price synchronization. It not only enriches the relevant literature of core competence and stock price synchronization, but also has important practical significance for the government and regulatory departments to improve the efficiency of capital market allocation.
Study of aerobic and anaerobic bacterial profile of nosocomial infections and their antibiotic resistance in a referral center, Southwest Iran: A three year cross-sectional study
Authors: Ahmadkhosravi Nazanin , Khosravi Azar Dokht , Asareh Zadegan Dezfuli Aram , Hashemzadeh Mohammad , Saki Morteza , Mehr Fatemeh Jahangiri , Izadpour Farokh
Published: November 2021

Background

The drug resistance is expected to be the most important challenge in infection control in Iran, where there is no local report or standard drug resistance monitoring system. Therefore, this study aimed to investigate the aerobic and anaerobic bacterial profile of nosocomial infections and their antibiotic resistance in Ahvaz, southwest Iran.

Methodology

The gram-positive and gram-negative bacteria were identified on the basis of conventional culture and biochemical tests. The antibiotic resistance of the bacterial isolates against antibiotics was determined by the disk diffusion method.

Results

Among total 1156 collected positive samples,E.coliand coagulase-negative staphylococci (CoNS) were the most frequent pathogenic gram negative bacteria (GNB) and gram positive bacteria (GPB) respectively. Drug susceptibility testing revealed that among GNB,P.aeruginosawas 100% resistant to amikacin, cefepime, ciprofloxacin and tetracycline. In the case ofE.coli, the resistance rate was (98%) for trimethoprim sulfamethoxazole and cefepime. For GPB,S.aureusshowed the highest resistance rates to amikacin (100%) and clindamycin (100%). In addition, CoNS strains showed a high level of resistance to doxycycline (100%), erythromycin (100%) and cefoxitin (97%). InBacteroeides fragilisisolates, the highest resistance rate belonged to clindamycin (72%), andClostridium perfringensstrains showed high level of resistance to penicillin (46%).

Conclusion

The results highlighted that there are distinct factors leading to antimicrobial resistance in Ahvaz, southwest Iran. The primary contributors to the resistance development, include poor surveillance of drug-resistant infections, poor quality of available antibiotics, clinical misuse, and the ease of access to antibiotics. Moreover, similar factors such as self-medication and the lack of regulation on medication imports play a role in antibiotic resistance in the region.
Gut microbiome affects the metabolism of metronidazole in mice through regulation of hepatic cytochromes P450 expression
Authors: Zemanová Nina , Lněničková Kateřina , Vavrečková Markéta , Anzenbacherová Eva , Anzenbacher Pavel , Zapletalová Iveta , Hermanová Petra , Hudcovic Tomáš , Kozáková Hana , Jourová Lenka
Published: November 2021

Microbiome is now considered as a significant metabolic organ with an immense potential to influence overall human health. A number of diseases that are associated with pharmacotherapy interventions was linked with altered gut microbiota. Moreover, it has been reported earlier that gut microbiome modulates the fate of more than 30 commonly used drugs and, vice versa, drugs have been shown to affect the composition of the gut microbiome. The molecular mechanisms of this mutual relationship, however, remain mostly elusive. Recent studies indicate an indirect effect of the gut microbiome through its metabolites on the expression of biotransformation enzymes in the liver. The aim of this study was to analyse the effect of gut microbiome on the fate of metronidazole in the mice through modulation of system of drug metabolizing enzymes, namely by alteration of the expression and activity of selected cytochromes P450 (CYPs). To assess the influence of gut microbiome, germ-free mice (GF) in comparison to control specific-pathogen-free (SPF) mice were used. First, it has been found that the absence of microbiota significantly affected plasma concentration of metronidazole, resulting in higher levels (by 30%) of the parent drug in murine plasma of GF mice. Further, the significant interaction between presence/absence of the gut microbiome and effect of metronidazole application, which together influence mRNA expression of CAR, PPARα, Cyp2b10 and Cyp2c38 was determined. Administration of metronidazole itself influenced significantly mRNA expression of Cyp1a2, Cyp2b10, Cyp2c38 and Cyp2d22. Finally, GF mice have shown lower level of enzyme activity of CYP2A and CYP3A than their SPF counterparts. The results hence have shown that, beside direct bacterial metabolism, different expression and enzyme activity of hepatic CYPs in the presence/absence of gut microbiota may be responsible for the altered metronidazole metabolism.
Revealing spatiotemporal travel demand and community structure characteristics with taxi trip data: A case study of New York City
Authors: Xie Chen , Yu Dexin , Zheng Xiaoyu , Wang Zhuorui , Jiang Zhongtai
Published: November 2021

Urban traffic demand distribution is dynamic in both space and time. A thorough analysis of individuals’ travel patterns can effectively reflect the dynamics of a city. This study aims to develop an analytical framework to explore the spatiotemporal traffic demand and the characteristics of the community structure shaped by travel, which is analyzed empirically in New York City. It uses spatial statistics and graph-based approaches to quantify travel behaviors and generate previously unobtainable insights. Specifically, people primarily travel for commuting on weekdays and entertainment on weekends. On weekdays, people tend to arrive in the financial and commercial areas in the morning, and the functions of zones arrived in the evening are more diversified. While on weekends, people are more likely to arrive at parks and department stores during the daytime and theaters at night. These hotspots show positive spatial autocorrelation at a significance level of p = 0.001. In addition, the travel flow at different peak times form relatively stable community structures, we find interesting phenomena through the complex network theory: 1) Every community has a very small number of taxi zones (TZs) with a large number of passengers, and the weighted degree of TZs in the community follows power-law distribution; 2) As the importance of TZs increases, their interaction intensity within the community gradually increases, or increases and then decreases. In other words, the formation of a community is determined by the key TZs with numerous traffic demands, but these TZs may have limited connection with the community in which they are located. The proposed analytical framework and results provide practical insights for urban and transportation planning.