bluuebunny/crossref_metadata_2025 huggingface dataset:
Men’s Experiences in Feminized Occupations on the Example of Selected Professions
Authors: Dudak Anna
Published: December 2021

The issues raised in this article concern the functioning of men in feminized professions. The aim of the study was to gather experiences of men working in jobs dominated by women. The research included twenty men and was conducted between February and April 2020 in Poland, using a narrative interview. Research problems were focused on men’s attitudes toward their jobs, the assessment of career advancement opportunities, advantages and disadvantages resulting from working in a feminine environment, relations with colleagues and employers, and reactions of their environment. The interviews revealed a relatively positive image of men’s experiences relating to working with women. The respondents did not notice any specific difficulties in their professions caused by gender stereotypes. They expressed a view that working among women was like any other job. Few difficulties mentioned by the respondents were related mostly to the issue of assistance in activities requiring strength or technical knowledge rather than competences related to a specific profession. Moreover, the interviewees treated their professions as an opportunity for self-development and for gaining experience that they would not have been able to gain in a typically male environment.
Student Well-Being in the Context of Erik Allardt’s Theory of Welfare and Urie Bronfenbrenner’s Ecological Systems Theory of Development
Authors: Łukasik Izabella Maria
Published: December 2021

Samopoczucie ucznia w szkole decyduje o jego sukcesie edukacyjnym oraz funkcjonowaniu w grupie rówieśników w przestrzeni szkoły.  Celem niniejszego artykułu stało się wskazanie na  możliwość wykorzystania  koncepcji dobrobytu Erika Allardta dla określenia wymiarów samopoczucia ucznia w szkole przy uwzględnieniu kontekstów środowiskowych. Wyodrębniono wskaźniki samopoczucia ucznia, umocowane w systemie ekologicznym Bronfenbrennera, które pozwolą na określenie interesującego badawczo przedmiotu.            Nie można pominąć osobistej oceny sytuacji szkolnej w kontekście indywidualnych preferencji, skoro samopoczucie rzutuje na realizację wyzwań związanych z różnorodnymi zadaniami edukacyjnymi. Właściwe rozpoznanie trudności pozwala na wkroczenie z działaniem interwencyjnym w te miejsca, które wymagają naprawy.            Zaproponowane wskaźniki samopoczucia mogą służyć jako itemy zastosowane w badaniach kwestionariuszowych. Pozwalają na wielopłaszczyznowy ogląd uwarunkowań, wpływających na odczucie dobrostanu ucznia. Właściwe rozpoznanie problemu daje szansę podjęcia działań korekcyjnych.
Questioning the Phenomenological Foundations of Marton’s Research Approach
Authors: Moroz Jacek
Published: December 2021

The purpose of this article is to try to answer the question: is phenomenographic research underlying (in a broad sense) phenomenological assumptions? It is an important question because opinions on this topic are divided. Some researchers argue that phenomenography derive from philosophical phenomenology. Phenomenology is even treated as a philosophical foundation of phenomenographic research. In this article I argue that the statement on similarities and connections between the two approaches and especially the claim that phenomenography has phenomenological roots are based on mistaken interpretation of the method created by Ference Marton.
Dotowanie instytucji kultury ze środków krajowych w świetle niekomercyjnego charakteru tych jednostek
Authors: Kołaczkowski Bartosz , Ratajczak Małgorzata
Published: December 2021

W opracowaniu podjęto problematykę prawnych rozwiązań dotyczących dotowania instytucji kultury ze środków krajowych. Analizie i ocenie poddano m.in. przepisy dotyczące dotacji podmiotowej, dotacji celowych budżetowych czy wreszcie dotacji z państwowych funduszy celowych. W podsumowaniu podkreślono, że dotacje są najważniejszym źródłem finansowania instytucji kultury (stanowiących podstawową formę prawną organizowania działalności kulturalnej przez podmioty publiczne), przy czym szczególne znaczenie ma przyznawana obligatoryjnie przez organizatora instytucji dotacja podmiotowa. W artykule wykazano ponadto, że zaletą systemu dotowania polskiej kultury jest duże zróżnicowanie dotacji celowych, co zdecydowanie zwiększa możliwości pozyskiwania środków finansowych przez instytucje kultury.
Oddziaływanie pandemii COVID-19 na finanse jednostek samorządu terytorialnego
Authors: Łubina Joanna
Published: December 2021

Recesja spowodowana pandemią COVID-19 oraz wprowadzonym lockdownem była ważnym czynnikiem oddziałującym na stan finansów samorządu terytorialnego w latach 2020–2021. Pandemia wymusiła konieczność dynamicznych zmian i dostosowania się jednostek samorządu terytorialnego do nowej rzeczywistości. W artykule podjęto próbę oceny wpływu pandemii COVID-19 na sposób wydatkowania środków publicznych przez jednostki samorządu terytorialnego. Zaprezentowano szanse i zagrożenia wywołane pandemią COVID-19 na funkcjonowanie jednostek samorządu terytorialnego podyktowane zmieniającym się ustawodawstwem w zakresie dochodów i wydatków, na szczeblu gmin, powiatów i województw.
Nature in Progress – Tocqueville and the Transformation of Natural Law
Authors: Smrcz Ádám
Published: December 2021

Hayden White famously claimed that Tocqueville’s emplotment of history was „tragic” by genre, and his ideological implications were „radical”. The aim of this paper is to argue that this interpretation is correct, but that our arguments will be based on a subject entirely ignored by White: Tocqueville’s  meagre scarce remarks on nature and natural law. According to their commonsensical definition, natural laws must „stem from God, nature, or reason”, but this relationship in Tocqueville is highly problematic. As I intend to prove, Tocqueville probably did acknowledge the existence of natural laws, and even intended to describe their resulting obligations (as in the case of what virtuous deeds are, or what humanity is etc.), but the way he defined nature herself suggests that the precise content of such obligations cannot be settled easily. Hence, according to our claim, a disturbing tension can be observed between the way Tocqueville attempted to describe certain natural laws, and the way he defined natural laws in general. Furthermore, this tension is analogous with the aforementioned friction between the author’s personal convictions and his scientific conclusions.
Virtual Reality? Investment Consultants’ Claims About Their Own Performance
Authors: Cookson Gordon , Jenkinson Tim , Jones Howard , Martinez Jose Vicente
Published: December 2021

Investment consultants market their services by claiming their fund manager recommendations add significant value. Using nonpublic data sourced from investment consultants and the UK regulator, we find no such evidence, but identify several practices that explain their exaggerated claims: comparisons to benchmarks instead of peers, inclusion of simulated and backfilled returns, use of investment horizons that allow losers to be forgotten, and unexplained exclusions of products from the analysis. Consultants do not fully disclose their methodology to investors, who therefore cannot verify or reliably compare their performance.

This paper was accepted by Haoxiang Zhu, finance.

Supplemental Material: Data and the internet appendix are available at https://doi.org/10.1287/mnsc.2021.4218 .
On the Price of Anarchy for Flows over Time
Authors: Correa José , Cristi Andrés , Oosterwijk Tim
Published: December 2021

Dynamic network flows, or network flows over time, constitute an important model for real-world situations in which steady states are unusual, such as urban traffic and the internet. These applications immediately raise the issue of analyzing dynamic network flows from a game-theoretic perspective. In this paper, we study dynamic equilibria in the deterministic fluid queuing model in single-source, single-sink networks—arguably the most basic model for flows over time. In the last decade, we have witnessed significant developments in the theoretical understanding of the model. However, several fundamental questions remain open. One of the most prominent ones concerns the price of anarchy, measured as the worst-case ratio between the minimum time required to route a given amount of flow from the source to the sink and the time a dynamic equilibrium takes to perform the same task. Our main result states that, if we could reduce the inflow of the network in a dynamic equilibrium, then the price of anarchy is bounded by a factor, parameterized by the longest path length that converges to [Formula: see text], and this is tight. This significantly extends a result by Bhaskar et al. (SODA 2011). Furthermore, our methods allow us to determine that the price of anarchy in parallel-link and parallel-path networks is exactly 4/3. Finally, we argue that, if a certain, very natural, monotonicity conjecture holds, the price of anarchy in the general case is exactly [Formula: see text].
On Designing a Socially Optimal Expedited Service and Its Impact on Individual Welfare
Authors: Roet-Green Ricky , Shetty Aditya
Published: December 2021

Problem definition: We consider the problem faced by a welfare-maximizing service provider who must make a decision on how to split a fixed quantity of resources between two variants of the service: a standard variant and an expedited variant. The service is mandatory, but customers can choose between the two variants. Choosing the expedited variant requires enrollment that incurs a fixed cost per period. Customers are strategic and have the same cost of waiting but are heterogeneous in the rate at which they use the service. Academic/practical relevance: The option of expedited security at U.S. airports (TSA PreCheck) is an instance where this problem arises. As has been the case with the PreCheck program, providers that offer expedited service may face criticism from customers, with the main concern being that the diversion of resources to expedited services increases wait time for regular customers. This has important policy implications for the provider, especially a government organization such as the TSA. Existing literature has focused on service differentiation as a means to maximize profit or overall social welfare, but its effect on individual customers has received little attention. Methodology: We find customer’s equilibrium decisions for any allocation choice made by the provider. Using the equilibrium result, we solve for the allocation choice that maximizes social welfare. Results: Even when customers behave strategically, an expedited service offered in parallel to a standard service cannot only increase overall welfare, but also do so for each customer individually. We also find that in a scenario where some customers lose out because of the expedited service, improving the efficiency of the expedited service is more effective than decreasing the enrollment cost to help those who are worse off. Managerial implications: The gains from offering expedited service do not have to come at the expense of regular customers. When they do, we provide recommendations for which decision levers are most effective at making the system fair.
Queues with Redundancy: Is Waiting in Multiple Lines Fair?
Authors: Nageswaran Leela , Scheller-Wolf Alan
Published: December 2021

Problem definition: We study service systems where some (so-called “redundant”) customers join multiple queues simultaneously, enabling them to receive service in any one of the queues, while other customers join a single queue. Academic/practical relevance: The improvement in overall system performance due to redundant customers has been established in prior work. We address the question of fairness—whether the benefit experienced by redundant customers adversely affects others who can only join a single line. This question is particularly relevant to organ transplantation, as critics have contended that multiple listing provides unfair access to organs for patients based on wealth. Methodology: We analyze two queues serving two classes of customers; the redundant class joins both queues, whereas the nonredundant class joins a single queue randomly. We compare this system against a benchmark wherein the redundant class resorts to joining the shortest queue (JSQ) if multiple queue joining were not allowed, capturing the most likely case if multilisting was prohibited: Affluent patients could still afford to list in the region with the shorter wait list. Results: We prove that when the arrival rate of nonredundant customers is balanced across both queues, they actually benefit under redundancy of the other class—that is, redundancy is fair. We also establish that redundancy may be unfair under some circumstances: Nonredundant customers are worse off if their arrival rate is strongly skewed toward one of the queues. We illustrate how these findings apply in the organ-transplantation setting through a numerical study using publicly available data. Managerial implications: Our analysis helps identify when, and by how much, multiple listing may be unfair and, as such, could be a useful tool for policy makers who may be concerned with trying to ensure equitable access to resources, such as organs, across patients with differing wealth levels.
The Instructions of Melanesian Cargo Cults for the Asia-Pacific Future
Authors: Winston Trompf Garry
Published: December 2021

So-called cargo cults are new religious movements best known among the indigenous population of Oceania, especially Melanesia. Their focus of attention is the mystery surrounding the new goods brought by light-skinned strangers in awe-striking ocean-going vessels and (later) in great flying ‘bird-like’ containers. Various socio-religious movements arose in response to these European-style wares (later internationally-marketed commodities), or “the Cargo” (pidgin: Kago), often in agitated collective expectation of an extraordinary arrival of new riches. The Melanesian outbursts have been typically inspired by prophet-type leaders, with their messages reflecting a transition between indigenous traditions and more settled islander Christianities. This paper moves on from describing and explaining southwest Pacific cargo-type movements to the issue of the ethos out of which they arose, and addresses the sociology of hope for Cargo (or modern commodities in plenty) as a global issue, best described as “Cargoism.” Sets of beliefs in the coming bounty and changing power of Cargo have much more than ‘provincial’ or local-indigenous implications. They point to a worldwide plethora of expectations wherein material items define the essential comforts of life and capture the individual, family and collective imaginations about the preferred human future. Exploring some of the ‘universally human’ implications within the logic of cargo-cult thinking in its Pacific context, this paper introduces Cargoism as a transoceanic and intercontinental issue that has enormous environmental and politico-economic ramifications. Presages of environmental stress lie with globalizing cargoist dreams and pressures, including hopes for progress and technological solutions offered by trade and commercial expansions (proffered by powerful nations, including China, for the Asia-Pacific future).
Burnout Among Healthcare Professionals in Bosnia and Herzegovina
Authors: Jusic Mersiha
Published: December 2021

Burnout, a state of stress-induced emotional, physical, and mental exhaustion, continues to be a topic of interest across a broad array of sciences. It is because burnout not only causes psychosomatic problems, but also has an effect on job performance, which is vital in high-stake professions. Therefore, exploring the level of healthcare professionals’ burnout, and understanding which work-place factors are correlated with it, is of outmost importance. For this purpose, the present correlational study explored this issue in a convenience sample of 209 MDs and nurses from primary healthcare institutions in Bosnia and Herzegovina, including, for the first time, a comprehensive number of psychosocial factors at work. Interestingly, the majority of healthcare professionals scored low on burnout measures of MBI. Nevertheless, one fifth of participants had potential early warning signs of burnout. Compared to their colleagues in other European countries, Bosnian-Herzegovinian doctors experience lower yet comparable levels of emotional exhaustion, lower depersonalization, and higher sense of personal achievement. Furthermore, nurses show an even more beneficial trend on all three burnout dimensions. In addition, the study established some significant positive predictors of burnout dimensions pertaining to the work environment. More precisely, quantitative workload and decision-making demands were found to be positive predictors of emotional exhaustion, while the strongest predictors of depersonalization were work-place support (from colleagues and superiors) and self-esteem. Significant predictors of personal accomplishment were perception of mastery and work centrality. This suggests that burnout among healthcare professionals arises both from the immediate workplace factors and individual ones, therefore implicating institutions in its prevention and reduction.
World War I and Gendering of the Army in Colonial Punjab
Authors: Deswal Anisha
Published: December 2021

This paper seeks to investigate the impulses that encouraged a ‘gendering’ process and its crystallization in colonial Punjab in relation to the masculine culture propagated by the institution of a military-martial structure by the British Raj. The imperial/colonial gender perceptions led to the creation of gendered spaces in a manner conforming to the masculine ideology of the army. This is highlighted through different aspects of the lives of both men and women – their struggles, works, contributions, dreams and politics – before, during and after the First World War (1914-18). As a result, there emerged amongst the soldiers’ new high-class martial castes, middle-class patriarchal structures, and ideological pillars keen on constructing and upholding ‘ideal masculinity’ and ‘safe femininity’. The paper argues that the process of ‘gendering’ took place at two levels. On the one hand, the army structure of the colonial state paved the way for military-martial culture to exist on extreme masculine lines and, on the other hand, this ‘high’ masculine ideology percolated in the society and presented itself in contrast to the women of the region by further relegating them to the feminine spaces. Thus, the society in colonial Punjab presented a layered martial structure, which, in turn, dichotomized the gender binary. The paper attempts to reveal such ‘gender’ realities and experiences witnessed by the region of Punjab. In this context, the operation of imperial power and the resistance of the colonized to it; the space that was denied to the disadvantaged gender – women – and; the changes they imbibed along with the history of the mutual roles of women and soldiers become crucial to understand the ‘gendering’ process.
Factors influencing women's knowledge at scheduled postnatal visits: a multi-centre study in Kakamega, Kenya
Authors: Kiragu Charles , Osero Justus SO , Wanyoro Anthony K
Published: December 2021

Background/aims

Postnatal care is offered to mothers and their babies from birth and across the postnatal period. Visits are spread over the postnatal period, and a minimum of four visits is recommended. In many studies, postnatal visits in Africa have been reported to be low compared to antenatal visits. As a result of low postnatal visits, mothers are not able to utilise postnatal care services, resulting in delayed detection of and interventions for maternal and neonatal health problems, leading to high rates of maternal and neonatal morbidity and mortality. In Kenya, only 53% of mothers attend postnatal clinics; in Kakamega county, only 34% of mothers attend. This study aimed to establish factors influencing postnatal knowledge among mothers in selected hospitals in Kakamega, Kenya.

Methods

The study was a descriptive cross-sectional study involving 320 postnatal mothers recruited from four sub-counties. Systematic sampling was used to select eligible study participants. Data were collected using questionnaires that assessed the participants' knowledge of postnatal care in terms of what postnatal care is, recommended postnatal care, when to attend a clinic and the services offered at postnatal care clinics. The data were entered into a database and analysed using the Chi-squared test to assess how sociodemographic and socioeconomic characteristics were associated with knowledge of postnatal care.

Results

The majority of participants (73.1%) had poor or no knowledge of postnatal care and 89.7% had poor or no knowledge on when postnatal visits should be carried out. Most postnatal mothers (71.9%) received postnatal health information from health workers. Occupation (P<0.000), income (P<0.000), transport (P<0.000) and time taken to travel to hospital (P=0.034) were significantly associated with postnatal knowledge.

Conclusions

Knowledge on postnatal care is poor among postnatal mothers in Kakamega. The majority of participants obtained postnatal care information from health workers, and so it is recommended that Kakamega establishes other strategies for giving information on postnatal care, such as pamphlets to mothers.
Versions of Phenomena
Authors: Sauzet Sofie
Published: December 2021

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Slime
Authors: Leslie Esther
Published: December 2021

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inclusión de adolescentes latinoamericanos en L’Hospitalet de Llobregat
Authors: Gil-Azorín Pau
Published: December 2021

El presente artículo pretende contextualizar y hacer una aproximación teórica de conceptos para pensar en clave de inclusión socioeducativa, más específicamente, cuando nos encontramos con adolescentes migrantes procedentes de países latinoamericanos. Principalmente, se relata cuáles son las estrategias que se articulan desde los entes locales en Cataluña y más concretamente en ciudades como L’Hospitalet de Llobregat. En este estudio teórico, hay una breve introducción sobre qué es emigrar en la etapa de la adolescencia y, posteriormente, se exponen discursos centrados en la inclusión social de adolescentes migrantes y sobre la inclusión en los centros educativos de secundaria obligatoria, además de la importancia de la educación intercultural. Finalmente, se exponen las estrategias para el aprendizaje de la lengua catalana, principal problemática de los chicos y chicas en los institutos, y los programas de inclusión que se llevan a cabo en L’Hospitalet de Llobregat para fomentar la relación con la ciudad y la sociedad.
Bienes y elementos digitales: ¿dos mundos aparte?
Authors: Arnau Raventós Lídia
Published: December 2021

Los bienes con elementos digitales sirven de hilo conductor para detectar las diferencias entre la Directiva (UE) 2019/770 y la Directiva (UE) 2019/771. Las diferencias entre una y otra norma sugieren si es posible integrar el régimen de los elementos digitales (Directiva (UE) 2019/770) con las reglas contenidas en la Directiva (UE) sobre compraventa.
Derechos Humanos y Trabajo Social en México: nociones, compromisos y vocación en el estudiantado
Authors: Rodríguez Otero Luis M. , Cerros Rodríguez Elisa
Published: December 2021

Los Derechos Humanos representan uno de los principios fundamentales en la definición internacional del Trabajo Social. Se plantea una investigación cuantitativa mediante un diseño descriptivo-correlacional con el objetivo de analizar las actitudes del alumnado de la licenciatura de Trabajo Social mexicano hacia los derechos humanos. Se aplicó un cuestionario autoadministrado a 610 alumnos/as de la Universidad Autónoma de Nuevo León (UANL) y la Universidad de Guadalajara (UdeG), seleccionados a través de un muestreo aleatorio estratificado. En el instrumento se incluyeron: (1) un cuestionario sociodemográfico, (2) la escala de componente vocacional, (3) la escala de ámbitos de intervención de Trabajadores/as Sociales, (4) la escala Likert de resiliencia y (5) la Escala de Nociones sobre Derechos Humanos en Trabajo Social (NDHTS) y de Compromiso con los Derechos Humanos en Trabajo Social (CDHTS). Los resultados advierten la inferencia de la dimensión ventaja/utilidad en el componente vocacional del alumnado, así como un mayor peso de la dimensión aceptación de uno mismo y vida en cuanto a la resiliencia. Los conocimientos adquiridos en la formación profesional son superiores a los alcanzados en la vida cotidiana y el nivel de compromiso hacia los derechos humanos es medio-alto. Se observaron correlaciones directamente proporcionales entre las diferentes escalas y diferencias en función a las características sociodemográficas. Se considera necesario promover la inclusión de los DDHH en el currículum mediante una unidad de competencia específica.
Three-dimensional light-field microendoscopy with a GRIN lens array
Authors: Urner Tara M. , Inman Andrew , Lapid Benjamin , Jia Shu
Published: December 2021

Optical endoscopy has emerged as an indispensable clinical tool for modern minimally invasive surgery. Most systems primarily capture a 2D projection of the 3D surgical field. Currently available 3D endoscopes can restore stereoscopic vision directly by projecting laterally shifted views of the operating field to each eye through 3D glasses. These tools provide surgeons with informative 3D visualizations, but they do not enable quantitative volumetric rendering of tissue. Therefore, advanced tools are desired to quantify tissue tomography for high precision microsurgery or medical robotics. Light-field imaging suggests itself as a promising solution to the challenge. The approach can capture both the spatial and angular information of optical signals, permitting the computational synthesis of the 3D volume of an object. In this work, we present GRIN lens array microendoscopy (GLAM), a single-shot, full-color, and quantitative 3D microendoscopy system. GLAM contains integrated fiber optics for illumination and a GRIN lens array to capture the reflected light field. The system exhibits a 3D resolution of ∼100 µm over an imaging depth of ∼22 mm and field of view up to 1 cm2. GLAM maintains a small form factor consistent with the clinically desirable design, making the system readily translatable to a clinical prototype.
Frequency tuning for broadband terahertz emission from two-color laser-induced air plasma
Authors: Wang Linzheng , Zhang Zhelin , Xia Tianhao , Chen Yanping , Sheng Zhengming
Published: December 2021

Effective manipulation of broadband terahertz emission, especially on spectrum tuning, is of great importance for many applications. We demonstrate a method to realize frequency tuning of terahertz emissions from two-color laser-induced air plasmas. The terahertz central frequency is switched from 0.56 to 0.82 THz by changing the polarization state of the fundamental wave with a quarter-wave plate. Based on numerical simulation, it is found that this frequency tuning is due to the birefringence effect induced by the fundamental wave on the second harmonic inside the filament, which leads to a discrepancy on the polarization chirality of the two-color laser components. Two-color lasers with opposite chirality will emit terahertz radiation with higher central frequency compared to two-color lasers with the same chirality at moderate laser intensity.
Optical characterization of inhomogeneous thin films with randomly rough boundaries
Authors: Vohánka Jiří , Ohlídal Ivan , Buršíková Vilma , Klapetek Petr , Kaur Nupinder Jeet
Published: December 2021

An inhomogeneous polymer-like thin film was deposited by the plasma enhanced chemical vapor deposition onto silicon single-crystal substrate whose surface was roughened by anodic oxidation. The inhomogeneous thin film with randomly rough boundaries was created as a result. This sample was studied using the variable-angle spectroscopic ellipsometry and spectroscopic reflectometry. The structural model including the inhomogeneous thin film, transition layer, and identically rough boundaries was used to process the experimental data. The scalar diffraction theory was used to describe the influence of roughness. The influence of the scattered light registered by the spectrophotometer due to its finite acceptance angle was also taken into account. The thicknesses and optical constants of the inhomogeneous thin film and the transition layer were determined in the optical characterization together with the roughness parameters. The determined rms value of the heights of roughness was found to be in good agreement with values obtained using AFM. The results of the optical characterization of the studied inhomogeneous thin film with rough boundaries were also verified by comparing them with the results of the optical characterization of the inhomogeneous thin film prepared using the same deposition conditions but onto the substrate with a smooth surface.
Single-layered phase-change metasurfaces achieving efficient wavefront manipulation and reversible chiral transmission
Authors: Huang Yijia , Xiao Tianxiao , Xie Zhengwei , Zheng Jie , Su Yarong , Chen Weidong , Liu Ke , Tang Mingjun , Zhu Jianqi , Li Ling
Published: December 2021

Efficient control of the phase and polarization of light is of significant importance in modern optics and photonics. However, traditional methods are often accompanied with cascaded and bulky designs that cannot fulfill the ongoing demand for further integrations. Here, a single-layered metasurface composed of nonvolatile phase-change material Ge2Sb2Se4Te1 (GSST) is proposed with tunable spin-orbit interactions in subwavelength scale. According to the spin-dependent destructive or constructive interference, asymmetric transmission for circularly polarized incidence (extinction ratio > 8:1) can be achieved when GSST is in an amorphous state. Moreover, when GSST changes to crystalline state, reversed chiral transmission (extinction ratio > 12:1) can be observed due to the existence of intrinsic chirality. In addition, as the average cross-polarized transmitted amplitude is larger than 85%, arbitrary wavefront manipulations can be achieved in both states simultaneously based on the theory of Pancharatnam-Berry phase. As a proof of concept, several functional metasurface devices are designed and characterized to further demonstrate the validation of our design methodology. It is believed that these multifunctional devices with ultrahigh compactness are promising for various applications including chiroptical spectroscopy, EM communication, chiral imaging, and information encryption.
Optimizing DC restoration in Kramers-Kronig optical single-sideband receivers
Authors: Wang Tianyu , Corcoran Bill , Lowery Arthur
Published: December 2021

Kramers-Kronig optical single-sideband receivers remove the signal-signal beat interference (SSBI) that occurs when detecting a signal that has electrical signals mapped onto its optical field at the transmitter; such signals support electronic dispersion compensation without the need for a coherent receiver. To use the full range of the analog-to-digital converter’s (ADC) range, it is best to a.c.-couple the photocurrent, to remove its DC content; however, the DC must be restored digitally before the KK algorithm is applied. Recent publications have concentrated on perfectly determining the restored DC’s required level from the signal, with a view this is optimal for lowering error rates. In this paper, we investigate signal-signal beat interference (SSBI) cancellation in a single photodiode receiver using Kramers-Kronig receiver algorithm, with large variations in optical carrier-to-signal power ratio (CSPR) and DC offset level. Through simulations and experiments, we find a strategy to optimize the signal quality without the need of an extensive search for the DC offset value. We also find that a theoretically perfect determination of the original DC level does not provide best signal quality especially for low CSPRs; in order to achieve maximum cancellation of signal-signal beat interference, the level of the restored DC has an optimum value that depends on the optical CSPR. We define a digital CSPR, which is the value of the CSPR in the digital domain after DC restoration. Our measurements show that we simply need to bias the signal upwards and make the minimum signal above zero by 0.1% of the r.m.s. signal amplitude when the optical CSPR is low. For higher values of optical CSPR, the optimal digital CSPR is about 2-dB lower than the optical CSPR, and the optimal DC offset can be calculated from this digital CSPR. We find that the boundary between our low optical CSPR region and high optical CSPR region depends on the noise level in the system.
Development of gradient index microlenses for the broadband infrared range
Authors: Kasztelanic Rafal , Filipkowski Adam , Pysz Dariusz , Nguyen Hue Thi , Stepien Ryszard , Liang Sheng , Troles Johann , Karioja Pentti , Buczynski Ryszard
Published: December 2021

The development of gradient index free-form micro-optic components dedicated to the mid-infrared range is challenging due to the lack of appropriate technology. We propose a method for developing gradient index components for broadband infrared range beyond the transmission window of silicate glass based on nanostructurization using a stack-and-draw fiber drawing technique. A proof-of-concept microlens is developed and verified experimentally in the wavelength range 1.5–4.3 µm. The microlenses are composed of a set of nanorods with a diameter of 940 nm made of a pair of SiO2-PbO-Bi2O3-Ga2O3 based glasses ordered into the preliminary calculated binary pattern. The pattern forms effectively continuous parabolic refractive index distribution for infrared range according to Maxwell-Garnett effective medium model. The development of individual microlenses with a diameter of 118 µm and focal length of 278 µm at the wavelength of 3.75 µm are reported. A large array of 737 microlenses with an individual diameter of 125 µm and focal length of 375 µm is also presented and analyzed.
Acceleration of electrons by tightly focused azimuthally polarized ultrashort pulses in a vacuum
Authors: Zheng Yali , Cai Xunming , Zhao Xin , Wang Wei
Published: December 2021

Using the complex sink-source model (CSSM) and the Hertz potential method (HPM), the electromagnetic field expressions of tightly focused ultrashort azimuthally polarized pulses can be obtained. By numerically solving the relativistic Newton-Lorentz equation, the acceleration and confinement of electrons by the sub-cycle and few-cycle azimuthally polarized ultrashort pulses in vacuum are studied. Considering the radiation reaction force, it is found that electrons with an initial kinetic energy of less than 1MeV can be accelerated to hundreds of MeV and can be confined in the range of less than 1 micron for hundreds of femtoseconds in the direction perpendicular to the pulse propagation (transverse direction) by the pulses. With the increase of the beam waist and the intensity of the pulse, the electrons can obtain the exit kinetic energy exceeding 1GeV. When electrons are accelerated by the few-cycle pulses, the confined time of the electrons in the transverse direction is three times longer than that of the sub-cycle pulse. When the initial velocity of the electron points to a point in front of the focus, the electron can obtain the maximum exit kinetic energy. The change of the angular frequency corresponding to the spectral peak of the electromagnetic radiation from the electron acceleration with the electric field amplitude parameter E0 of the pulse is studied. The phenomena of redshift and blueshift of the spectrum peak frequency of the electron radiation with the E0 are found. These studies provide the methods to confine the movement of electrons in certain directions and accelerate electrons in the same time.
Composite laser beam separation technology for brittle transparent materials
Authors: Chen Tianting , Duan Jun , Xiong Wei , Deng Leimin
Published: December 2021

By combining a picosecond Bessel laser and a continuous-wave (CW) fiber Gaussian laser with the same optical axis, a composite laser beam separation (CLBS) technology that allows the fast, high-quality separation of brittle transparent materials was developed for the first time, to the best of our knowledge. In this experiment, 1-mm-thick soda lime glass was separated using this CLBS technology, and the CLBS separation mechanism was analyzed. The experimental results show that a separated surface similar to frosted polishing can be obtained by CLBS, and the edge chipping of the separated upper surface was no more than 0.5 µm. The separated sidewall was flat and smooth without separation defects such as cracks or broken edges, and the surface roughness (Ra) was 0.12 µm. The separation speed reached 12 mm/s and can be further improved by increasing the CW laser power density. This research provides a new way for lasers to separate brittle transparent materials.
Far-UV reflectance and stress of narrowband AlF3/LaF3 multilayers
Authors: López-Reyes Paloma , Honrado-Benítez Carlos , Gutiérrez-Luna Nuria , Ríos-Fernández Álvaro , Rodríguez-de Marcos Luis V. , Larruquert Juan I.
Published: December 2021

Upcoming space instrumentation, such as LUMOS (LUVOIR Ultraviolet Multi-Object Spectrograph) in LUVOIR (Large Ultraviolet Optical Infrared Surveyor) mission, demands efficient narrowband coatings centered in the far UV (FUV). Narrowband FUV coatings can be prepared with all-dielectric multilayers (MLs) based on two fluorides. This research evaluates the performance of AlF3/LaF3 FUV MLs prepared by thermal evaporation and compares this performance with MgF2/LaF3 MLs, which were previously investigated. FUV reflectance, stress, and the influence of substrate materials have been investigated, along with ML stability over time when stored in a desiccator. Coatings were deposited both on fused silica and on CaF2 crystals, two common optical substrates. AlF3/LaF3 MLs exhibited reduced stress compared with MgF2/LaF3 MLs, resulting in a larger thickness threshold before crack generation. This enables preparing MLs with more layers and hence with higher performance. AlF3/LaF3 MLs underwent lower reflectance decay over time compared with MgF2/LaF3 MLs. Fresh MLs centered at ∼160 nm displayed a peak reflectance close to 100%, and most of the AlF3/LaF3 MLs kept a reflectance of 99% after several months of storage. The bandwidth of AlF3/LaF3 MLs for a given number of layers was found to be somewhat larger than for MgF2/LaF3 MLs.
Einstellung gegenüber Online-Beratung: Eine Umfrage unter Berater:innen, Coaches und Therapeut:innen
Authors: Römer Cindy , Mundelsee Lukas
Published: December 2021

Spätestens seit der Corona-Pandemie ist das Thema „Digitalisierung“ auch in der Beratungswelt angekommen. Online-Beratung wird von vielen Praktizierenden jedoch mit großer Skepsis begegnet. Was genau diese negative Einstellung verursacht, wurde bislang nur wenig untersucht. Bisherige Studien bezogen sich entweder auf Video-Therapien oder auf die Einführung evidenzbasierter Praktiken. Ziel der vorliegenden Querschnittsstudie war es deshalb, mögliche Merkmale zu ermitteln, die die Einstellung gegenüber Online-Beratung im Vergleich zur Präsenz-Beratung positiv oder negativ beeinflussen. Zur Erfassung der Einstellung wurde ein neues Instrument entwickelt, das verschiedene Merkmale von Beratung beschreibt, und mittels Online-Fragebogen bei 66 Personen aus den Bereichen Beratung, Therapie und Coaching eingesetzt. Faktorenanalytisch ergaben sich bei dem Instrument zwei unterschiedliche Einstellungsdimensionen, die in den anschließenden Regressionsanalysen von jeweils unterschiedlichen Personenmerkmalen prädiziert wurden. In Bezug auf die Dimension „Kernmerkmale von Beratungen“ wird eine negativere Einstellung nur durch eine höhere Berufserfahrung vorhergesagt. Hinsichtlich der Dimension „Rahmenbedingungen von Beratungen“ zeigt sich eine positivere Einstellung gegenüber dem Online-Setting, wenn die Beratenden sich als Frau identifizieren, eine geringere Berufserfahrung vorweisen, im Bereich Coaching tätig sind oder an urbanen Orten praktizieren. Interessanterweise hatten weder die technische Affinität noch die subjektive Wichtigkeit des Datenschutzes Einfluss auf die Einstellung. Die Studie liefert damit wichtige Erkenntnisse für die weitere Erforschung und auch Praxis von Online-Beratung und vermag bisher widersprüchliche Befunde in dem Bereich zu erklären.
Haploinsufficiency by minute MutL homolog 1 promoter DNA methylation may represent unique phenotypes of microsatellite instability-gastric carcinogenesis
Authors: Harada Hiroki , Nie Yusuke , Araki Ippeita , Soeno Takafumi , Chuman Motohiro , Washio Marie , Sakuraya Mikiko , Ushiku Hideki , Niihara Masahiro , Hosoda Kei , Kumamoto Yusuke , Naitoh Takeshi , Sangai Takafumi , Hiki Naoki , Yamashita Keishi
Published: December 2021

Promoter DNA methylation ofMutL homolog 1 (MLH1)is considered to play a causative role in microsatellite instability (MSI) carcinogenesis in primary gastric cancer, and a high MSI status is associated with treatment sensitivity to human cancers. Nevertheless, clinicopathological analysis is defective forMLH1methylation status in a quantitative manner. We newly developed quantitative methylation specific PCR using a TaqMan probe and applied it to 138 patients with primary gastric cancer who underwent gastrectomy in addition to basic molecular features such as MSI, Epstein Barr virus, and other DNA methylation status. (1) In primary gastric cancer, median methylation value was 0.055, ranging from 0 to 124.3. First,MLH1hypermethylation was strongly correlated with MSI-High/MSI-Low status and suppressed immunostaining (P< 0.0001). (2) TheMLH1hypermethylation was associated with advanced age (P= 0.0048), antral location (P= 0.0486), synchronous multiple gastric cancer (P= 0.0001), and differentiated histology (P= 0.028). (3) Log-rank plot analysis identified the most relevant cut-off value (0.23) to reflect gentle phenotypes inMLH1hypermethylation cases (P= 0.0019), especially in advanced gastric cancer (P= 0.0132), which are designated as haploinsufficiency of MSI (MSI-haplo) phenotype in this study. (4) In synchronous multiple gastric cancer,MLH1hypermethylation was not necessarily confirmed as field cancerization. (5) MSI-haplo defined byMLH1methylation status represented distinct prognostic phenotype even after molecular classifications.MLH1hypermethylation designated as MSI-haplo may represent unique prognostic phenotype during gastric carcinogenesis.
Tracheostomy in COVID-19 acute respiratory distress syndrome patients and follow-up: A parisian bicentric retrospective cohort
Authors: Evrard Diane , Jurcisin Igor , Assadi Maksud , Patrier Juliette , Tafani Victor , Ullmann Nicolas , Timsit Jean-François , Montravers Philippe , Barry Béatrix , Weiss Emmanuel , Rozencwajg Sacha
Published: December 2021

Background

Tracheostomy has been proposed as an option to help organize the healthcare system to face the unprecedented number of patients hospitalized for a COVID-19-related acute respiratory distress syndrome (ARDS) in intensive care units (ICU). It is, however, considered a particularly high-risk procedure for contamination. This paper aims to provide our experience in performing tracheostomies on COVID-19 critically ill patients during the pandemic and its long-term local complications.

Methods

We performed a retrospective analysis of prospectively collected data of patients tracheostomized for a COVID-19-related ARDS in two university hospitals in the Paris region between January 27th (date of first COVID-19 admission) and May 18th, 2020 (date of last tracheostomy performed). We focused on tracheostomy technique (percutaneous versus surgical), timing (early versus late) and late complications.

Results

Forty-eight tracheostomies were performed with an equal division between surgical and percutaneous techniques. There was no difference in patients’ characteristics between surgical and percutaneous groups. Tracheostomy was performed after a median of 17 [12–22] days of mechanical ventilation (MV), with 10 patients in the “early” group (≤ day 10) and 38 patients in the “late” group (> day 10). Survivors required MV for a median of 32 [22–41] days and were ultimately decannulated with a median of 21 [15–34] days spent on cannula. Patients in the early group had shorter ICU and hospital stays (respectively 15 [12–19] versus 35 [25–47] days; p = 0.002, and 21 [16–28] versus 54 [35–72] days; p = 0.002) and spent less time on MV (respectively 17 [14–20] and 35 [27–43] days; p<0.001). Interestingly, patients in the percutaneous group had shorter hospital and rehabilitation center stays (respectively 44 [34–81] versus 92 [61–118] days; p = 0.012, and 24 [11–38] versus 45 [22–71] days; p = 0.045). Of the 30 (67%) patients examined by a head and neck surgeon, 17 (57%) had complications with unilateral laryngeal palsy (n = 5) being the most prevalent.

Conclusions

Tracheostomy seems to be a safe procedure that could help ICU organization by delegating work to a separate team and favoring patient turnover by allowing faster transfer to step-down units. Following guidelines alone was found sufficient to prevent the risk of aerosolization and contamination of healthcare professionals.
On predicting particle capture rates in aquatic ecosystems
Authors: Espinosa-Gayosso Alexis , Ghisalberti Marco , Shimeta Jeff , Ivey Gregory N.
Published: December 2021

Recent advances in understanding the capture of moving suspended particles in aquatic ecosystems have opened up new possibilities for predicting rates of suspension feeding, larval settlement, seagrass pollination and sediment removal. Drawing on results from both highly-resolved computational fluid dynamics (CFD) simulations and existing experimental data, we quantify the controlling influence of flow velocity, particle size and collector size on rates of contact between suspended particles and biological collectors over the parameter space characterising a diverse range of aquatic ecosystems. As distinct from assumptions in previous modeling studies, the functional relationships describing capture are highly variable. Contact rates can vary in opposing directions in response to changes in collector size, an organism’s size, the size of particles being intercepted (related to diet in the case of suspension feeders), and the flow strength. Contact rates shift from decreasing to increasing with collector diameter when particles become relatively large and there is vortex shedding in the collector wake. And in some ranges of the ecologically relevant parameter space, contact rates do not increase strongly with velocity or particle size. The understanding of these complex dependencies allows us to reformulate some hypotheses of selection pressure on the physiology and ecology of aquatic organisms. We discuss the benefits and limitations of CFD tools in predicting rates of particle capture in aquatic ecosystems. Finally, across the complete parameter space relevant to real aquatic ecosystems, all quantitative estimates of particle capture from our model are provided here.