bluuebunny/crossref_metadata_2025 huggingface dataset:
Nasopharyngeal Dysbiosis Precedes the Development of Lower Respiratory Tract Infections in Young Infants, a Longitudinal Infant Cohort Study
Authors: Lapidot Rotem , Faits Tyler , Ismail Arshad , Allam Mushal , Khumalo Zamantungwak , MacLeod William , Kwenda Geoffrey , Mupila Zachariah , Nakazwe Ruth , Segrè Daniel , Johnson William Evan , Thea Donald M , Mwananyanda Lawrence , Gill Christopher J
Published: April 2022

Background: Infants suffering from lower respiratory tract infections (LRTIs) have distinct nasopharyngeal (NP) microbiome profiles that correlate with severity of disease. Whether these profiles precede the infection or a consequence of it, is unknown. In order to answer this question, longitudinal studies are needed.

Methods: We conducted an analysis of a longitudinal prospective cohort study of 1,981 Zambian mother-infant pairs who underwent NP sampling from 1-week through 14-weeks of age at 2-3-week intervals. Ten of the infants in the cohort who developed LRTI were matched 1:3 with healthy comparators. We completed 16S rRNA gene sequencing on the samples each of these infants contributed, as well as from baseline samples of the infants’ mothers, and characterized the normal maturation of the healthy infant NP microbiome, compared to infants who developed LRTI.

Results: The infant NP microbiome maturation was characterized by transitioning from Staphylococcus dominant to respiratory-genera dominant profiles during the first three months of life, similar to what is described in the literature. Interestingly, infants who developed LRTI had NP dysbiosis before infection, in most cases as early as the first week of life. Dysbiosis was characterized by the presence of Novosphingobium, Delftia, high relative abundance of Anaerobacillus, Bacillus, and low relative abundance of Dolosigranulum, compared to the healthy controls. Mothers of infants with LRTI also had low relative abundance of Dolosigranulum in their baseline samples compared to mothers of infants that did not develop an LRTI.

Conclusions: Our results suggest that NP microbiome dysbiosis precedes LRTI in young infants and may be present in their mothers as well. Early dysbiosis may play a role in the causal pathway leading to LRTI or could be a marker of other pathogenic forces that directly lead to LRTI.
On sequence spaces defined by a sequence of moduli and an extension of Kuttner’s theorem
Authors: Soomer Virge
Published: April 2022

Let  A = (ank) be an infinite matrix with  limn∑kank ≠ 0, and let p=(pk) be a sequence of positive real numbers. If 1≤pk<H<∞, then the strong A-summability field (with the exponent p) is included in the summability field of A. But the result known as Kuttner’s theorem asserts that if 0<pk=˜p<1 and A is regular, then there is a sequence which is strongly (C,1)-summable but which is not A-summable. This result was extended by Thorpe (cf. Theorem 6) and Maddox (cf. [8] and [9]). The purpose of the present paper is to extend the results of Thorpe and Maddox to a lacunary strong summability with respect to a sequence of modulus functions.
An alternative way to derive the geodesic deviation equation for rapidly diverging geodesics
Authors: Mullari Tanel , Tammelo Risto
Published: April 2022

We present a derivation of the equation of geodesic deviation under the assumption that the geodesics are adjacent in some neighbourhood, but their rate of separation is arbitrary. The resulting modified equation of geodesic deviation is nonlinear, it reduces to the ordinary linear geodesic deviation equation when the changes of position of corresponding points on the two geodesics as well as the changes of directions of the corresponding tangents are small. Our derivation is straightforward but shorter and more lucid than the earlier ones. Some of the consequences of the modified equation are also discussed.
Indecomposable Banach spaces
Authors: Werner Dirk
Published: April 2022

This paper aims at describing Tim Gowers' contributions to Banach space theory that earned him the Fields medal in 1998. In particular, the construction of the Gowers-Maurey space, a Banach space not containing an unconditional basic sequence, is sketched as is the Gowers dichotomy theorem that led to the solution of the homogeneous Banach space problem. Moreover, Gowers' counterexamples to the hyperplane problem and the Schröder-Bernstein problem are discussed.

The paper is an extended version of a talk given at Freie Universität Berlin in December 1999; hence the reference to the next millennium at the very end actually appeals to the present millennium. It should be accessible to anyone with a basic knowledge of functional analysis and of German.
On the A-statistical core of sequences of complex numbers
Authors: Çakan Celal , Çoşkun Hüsamettin
Published: April 2022

In [4], the concept of A-statistical core of a sequence of complex numbers was introduced and necessary and sufficient conditions were given for a summability matrix T to satisfy K-core(Tx) ⊆ stA-core(x) whenever x is a bounded complex sequence. In the present paper, we determine the classes of summability matrices T such that stA-core(Tx) ⊆ K-core(x) and stA-core(Tx) ⊆ stB-core(x) for all bounded complex sequences x.
Comparison of small area estimation methods: simulation study in EURAREA project
Authors: Sõstra Kaja
Published: April 2022

In literature several techniques have been introduced for small area estimation. It has not been proved theoretically that some estimator is superior to others. The focus of this paper is on comparison of some estimators (direct, GREG and EBLUP estimators with correlated area and time effects) in a simulation study. The individual-level models are used. The target of estimation is the average disposable income in small geographical regions of Finland. The results given here are developed in the framework of the EURAREA project, where the author of this paper was responsible for the simulation study.
Approximate design-based variance of functions of covariance matrix
Authors: Traat Imbi
Published: April 2022

Functions of a design-weighted estimator ^ S  of the finite population covariance matrix are considered. For these functions (determinant, Hotelling’s T2) the approximate (Taylor series based) variances are derived. For ^ S also the exact dispersion matrix is derived. These are generalizations of earlier results for independent identically distributed (i.i.d.) variables. A simulation study supports the derived formulae.
A weak form of continuity
Authors: Ekici Erdal
Published: April 2022

The aim of this paper is to introduce the notion of a new class of functions which generalize classes of α-irresolute, α-continuous, strongly α-irresolute, contra continuous and contra α-continuous functions.This class of functions is called slightly α-continuous. Moreover, basic properties and preservation theorems of slightly α-continuous functions are obtained and relationships between slightly α-continuous functions and α-co-closed graphs are investigated.
Invariance of the BLUE under the linear fixed and mixed effects models
Authors: Isotalo Jarkko , Möls Märt , Puntanen Simo
Published: April 2022

We consider the estimation of the parametric function X1β1 under the partitioned linear fixed effects model y=X1β1+X2β2+ε and the linear mixed effects model y=X1β1+X2γ2+ε,  where γ2 is considered to be a random vector. Particularly, we consider when the best linear unbiased estimator, BLUE, of X1β1 under the linear fixed effects model equals the corresponding BLUE under the linear mixed effects model.
Superpositional graphs
Authors: Peder Ahti , Tombak Mati
Published: April 2022

The class of superpositional graphs, which is defined as the set of graphs whose elements are generated by superposition, is a subclass of binary graphs. The properties of superpositional graphs are investigated, and necessary and sufficient conditions found for a binarygraph to be a superpositional graph.
Incidence of congenital hypothyroidism by gestational age: a retrospective observational study
Authors: Jo Ha Young , Yang Eun Hye , Kim Young Mi , Choi Soo-Han , Park Kyung Hee , Yoo Hye Won , Park Su Jeong , Kwak Min Jung
Published: April 2022

Background: Congenital hypothyroidism (CH) is the leading cause of preventable physical and intellectual disabilities. This study aimed to assess the incidence and clinical characteristics of CH in newborns.Methods: We retrospectively reviewed the medical records of all newborns delivered at the Pusan National University Hospital between January 2011 and March 2021. The incidence of CH was compared according to gestational age, birth weight, and small for gestational age (SGA). The patients aged ≥3 years who could not maintain normal thyroid function and required levothyroxine treatment were diagnosed with permanent CH. Logistic regression analysis was performed to compare CH risks.Results: Of 3,722 newborns, 40 were diagnosed with CH (1.07%). Gestational age and birth weight were significantly associated with CH incidence. The odds ratios (ORs) of CH in infants delivered at 32–37, 28–31, and <28 weeks were 2.568 (95% confidence interval [CI], 1.141–5.778), 5.917 (95% CI, 2.264–15.464), and 7.441 (95% CI, 2.617–21.159) times higher, respectively, than those delivered at term. The ORs of CH in infants weighing 1,500–2,499 g, 1,000–1,499 g, and <1,000 g were 4.664 (95% CI, 1.928–11.279), 11.076 (95% CI, 4.089–29.999), and 12.544 (95% CI, 4.350–36.176) times greater, respectively, than those in infants weighing ≥2,500 g. The OR of CH was 6.795 (95% CI, 3.553–13.692) times greater in SGA than in non-SGA infants.Conclusion: The CH incidence in South Korea has increased significantly compared with that in the past. Gestational age, birth weight, and SGA were significantly associated with CH incidence.
Research of changes in the level of endothelin-1 in experimental diabetic retinopathy. comparison of methods of correction
Authors: Sirman Y. , Preis N. , Savytskyi I.
Published: April 2022

Diabetic retinopathy (DR) according to the WHO is the main cause of decreased vision and blindness due to diabetes.

The aim of the study: to compare the effectiveness of correction of vasoconstriction in experimental diabetic retinopathy under the influence of different methods of correction.

Our results indicate a violation of the functional state of blood vessels on the 30th day of experimental diabetic retinopathy with subsequent progression of pathological changes on the 60th and 180th day of the study, as evidenced by a significant increase in endothelin-1 in the 2nd group (p <0.001), most pronounced in the 3rd stage.In the analysis of data of group №3 it was found that the correction of pathological conditions with hypoglycemic agents has a positive effect, but does not allow to significantly correct pathologically increased levels of endothelin-1, which indicates the need for additional correction tools other than hyperglycemia.The results of group 4 indicate that the involvement of a donor of nitric oxide and aflibercept in the correction of diabetic retinopathy corrects the level of the studied marker, the most pronounced effect is observed on the 180th day of the experiment, but normative values can not be achieved. It was found that in the 5th group, in which the correction of the simulated pathological condition was performed by reducing hyperglycemia, the introduction of aflibercept and bromfenac gives positive results, but less pronounced than in the 4th group, where L-arginine solution was added to the complex correction. .It was found that rats of group 6, which simulated diabetic retinopathy with subsequent correction of hyperglycemia, administration of aflibercept, L-carnitine and bromfenac have a pronounced effectiveness of the proposed method of correction compared to previous methods, the level of vasoconstriction stage and continues to recover in the following stages of the experiment, but does not reach the normative values. The obtained data suggest that the method of correction selected in group 7, which includes reduction of hyperglycemia, administration of aflibercept, solution of L-arginine and citicoline is most effective for normalizing vascular tone and structural and functional state of the endothelium.
Optic nerve neuropathies – causative factors, methods of diagnostics, current and future possibilities of treatment
Authors: Kobak Joanna , Tyczyńska Magdalena , Forma Alicja , Dudek Iga , Maani Amr , Zembala Patryk , Baj Jacek
Published: April 2022

Introduction:  Optic neuropathies are a broad group of diseases in which the dominant disturbance is damage to the optic nerve, often irreversible. Underlying causes of neuropathy are both genetic and environmental. Despite limited treatment options, much research is currently being done on substances that could improve optic nerve function and alleviate the clinical consequences of optic nerve damage.

Purpose: This article describes current findings in both the optic nerve neuropathy pathophysiology and diagnosis of the disorder, as well as treatment options and future perspectives.

State of knowledge: The pathogenetic cause of neuropathy is mainly demyelination within the neural sheath, often caused by inflammation. It is characterized by progressive loss of vision. The most common genetic cause of optic neuropathy is mitochondrially inherited Leber hereditary optic neuropathy (LHON) and is characterized by mostly sudden and painless loss of visual acuity. Toxic neuropathies are a group of diseases caused by heavy metals, pharmaceuticals, methanol and carbon monoxide. Nutritional neuropathy is mainly related to vitamin B1, B9 and B12 deficiency, and is a rare example of neuropathy that can be curable at the early stage of the disease. Another group of neuropathies is caused by ischemia and can be divided according to the place of the optic nerve affected – AION (anterior ischemic optic neuropathy) and PION (posterior ischemic optic neuropathy).

Conclusions: The therapeutic options in the treatment of optic neuropathy strictly depend on the causative factor. Nutritional deficiencies are treated with appropriate supplementation, so it is vital to truly determine the missing vitamins and elements.
Ketoacidosis and otitis media as a potencial cause of cerebral venous thrombosis in a 7-year-old boy
Authors: Lipińska Justyna , Lipiński Łukasz , Kowalczuk Maria , Kopeć Izabela , Mitek-Palusińska Joanna , Woźniak Magdalena
Published: April 2022

Cerebral venous sinus thrombosis (CVST) in childhood is a rare disorder, occurring most often in the neonatal period, with mortality approaching 10%. This condition has multifactorial etiology including common childhood illnesses such as fever, infection, dehydration, and anemia, as well as acute and chronic medical conditions such as congenital heart disease, nephrotic syndrome,  and malignancy. Thrombosis can also develop and propagate in response to local venous stasis. A large number of children have coincident local head or neck pathology, including head trauma, brain tumors, or recent intracranial surgery. Clinical symptoms are frequently nonspecific and include seizures, depressed level of consciousness, coma, lethargy, nausea, vomiting, headache, visual impairment, papilledema, and hemiparesis, which may often obscure the diagnosis and delay treatment. In the case of patients with neurological symptoms, imaging studies such as computed tomography (CT)  and magnetic resonance imaging (MRI) are invaluable in diagnostics of various pathologies of the nervous system, because of their non-invasiveness, high sensitivity, and specificity. Early diagnosis with management along with a plan for secondary prevention can save from catastrophic consequences.
Infections in the maxillofacial region in the clinic material – retrospective analysis
Authors: Wróbel-Roztropiński Artur , Zagacki Dawid , Kruczykowska Lidia , Kozakiewicz Marcin
Published: April 2022

Infections in the maxillofacial and neck region are a serious problem nowadays. Lately diagnosed infection may lead to many hazardous complications including spreading through superior thoracic aperture to the mediastinum. That affects everyday life of patients, including his ability to work. The aim of this study was to analyze the factors affecting work inability associated with the treatment of maxillofacial and neck infections. We made a retrospective analysis of medical documentation of patients treated in our Department due to the infections of maxillofacial and neck region. In our research, mostly men were burden with infections in the maxilliofacial region and neck (64.3%). Patient presented poor oral hygiene thus the main cause of the infection was periodontal. Treatment period (including hospitalization and inability to work) varied from 1 up to 124 days; Mostly affected are patients in their 3rd and 4th decade of life when they are professionally active. A proper treatment (including surgical and pharmacological) is required to allow those patients come back to their everyday life.
Many-Valued Logics and Bivalent Modalities
Authors: Bezerra Edson , Venturi Giorgio
Published: April 2022

In this paper, we investigate the family LS0.5 of many-valued modal logics LS0.5's. We prove that the modalities of necessity and possibility of the logics LS0.5's capture well-defined bivalent concepts of logical validity and logical consistency. We also show that these modalities can be used as recovery operators.
Does the type of funding influence research results – and do researchers influence funders?
Authors: Hove Kjetil Hatlebakk
Published: April 2022

Does a shift from hard to soft funding have an impact on research outcomes? Existing literature suggests that moving from hard money, such as lump-sum government-funded research, to commissioned research entails a greater risk of the researchers being influenced by the principal (the funding body). Based on literature and an empirical study, we identify two types of researcher roles: the influential consultant and the technical realist. The first type studies more advanced, important, and diffuse topics on behalf of principals high up in the hierarchy. They have a much greater experience of the issues discussed in this paper than the technical consultants. During the course of this study, we also discovered that the balance of power is not necessarily as one-sided as theory suggests: researchers can wield significant influence over the principals as well.
Constructivism and its risks in artificial intelligence
Authors: Lea Gary R
Published: April 2022

The research and development of artificial intelligence (AI) technologies involve choices that extend well beyond the search for narrow engineering solutions to problems. The label ‘constructivism’ is used to capture this larger realm of social choice. Drawing on the history of AI, a distinction is made between limited artificial narrow intelligence (ANI) and artificial general intelligence (AGI). Both forms, the paper argues, carry risks. Following this history, the paper outlines how different approaches to rationality have led to different ‘tribes’ of AI. No universal model of rationality is available to AI engineers. Choice is everywhere. The paper then moves to an exploration of the links between AI and chess. It argues that chess, far from being an objective measure of rationality and intelligence, reveals the subjective biases and risks involved in the pursuit of AI. The paper moves on to provides examples of various unstable and potentially dangerous race heats taking place in AI, including those among various AI research groups (public and private), among corporations and among states. The final section draws together the various risks of AI.
The change agent in innovation
Authors: Tann Jennifer
Published: April 2022

Much has been written on change management in the organization, and on the roles and expertise involved. But the change agent, whether internal or external to the organization, has received less attention. Change agents are characterized by a low boredom threshold; they need change to be energized and they may not fit in. This paper introduces examples of an academic change agent's activities in different contexts and the effects of change agent interventions. Elusive, the change agent moves on, or out, once the change has been initiated.
Can business schools use practical reasoning to help them with social impact?
Authors: Kawalek John Paul
Published: April 2022

This paper concerns the challenges that face university-based business schools. These challenges are concerned with their ability to maintain expectations in educational and research terms, whilst at the same time making impact in social contexts. This paper outlines how impact might be informed by a heightened awareness of the difference between pure and practical reasoning. This was a key concern of Immanuel Kant, who laid the foundation of a philosophical genre which, in this paper, is termed ‘practical reasoning’. The paper contrasts some of the most fundamental ideas of practical reasoning with other forms used to underpin the activities of contemporary business schools. The paper presents an argument about how the methodological, epistemological and philosophical insights drawn from this genre may have relevance to the contemporary requirement for social impact in university-based business schools.
Farmer-driven innovation: lessons from a case study of subterranean clover seed production
Authors: Moss Wesley M. , Nichols Phillip G.H. , Foster Kevin J. , Ryan Megan H. , Guzzomi Andrew L.
Published: April 2022

Farmers are often overlooked and undervalued as sources of innovation, but can be powerful drivers of ingenuity and development. We evaluate historical developments in the Australian subterranean clover seed-production industry as a case study of farmer-driven innovation. Subterranean clover seed machinery patents (75% of which were patented by farmers) are analysed using conventional innovation frameworks, such as the theory of inventive problem solving (TRIZ), to extract lessons for supporting farmer-driven innovation. The small scale of this industry, compared with mainstream cereal-cropping industries and the isolation of farmers, provides analogous lessons for agriculture in developing countries. Economic drivers are important in enabling farmer innovation and the value proposition for developing new inventions must be clear to justify the time and expense. Farmers are different from firms and their on-farm knowledge and experience can form an essential part of innovation. Drivers of innovation also differ, with farmers less likely to attempt to commercialize inventions. Farmers can also be hesitant to share their inventions, instead holding them as trade secrets in competitive industries. Support and collaboration are needed from government and researchers to assist in commercialization or dissemination of useful innovations and to prevent knowledge from being confined to a localized farmer or region. Advances in agriculture require farmer input in research and development, but the benefits will be greater if farmers are enabled to be drivers of innovation.
Spot alignment based on a five-photodiode receiver for a UWOC system
Authors: Xie Sheng , Mi Haining , Feng Renhai
Published: April 2022

In the traditional underwater
wireless optical communication (UWOC) system, spot alignment and
communication are divided into different paths. Moreover, the
attenuated optical signal is easily submerged by underwater noise,
affecting the accuracy of the spot alignment. In this paper, a novel,
to the best of our knowledge, five-photodiode receiver (5-PDR)
combining communication and spot alignment is proposed, which includes
transimpedance amplifiers (TIAs), gain stages, and output buffers.
Furthermore, a new denoising algorithm based on the hidden Markov
model (HMM) is introduced. Through combining the 5-PDR and the HMM
noising algorithm, spot alignment accuracy has been improved.
Simulation results show that the root mean square error (RMSE) of our
proposed method is reduced by 57.2%, compared with that of traditional
four-quadrant detector (4-QD). The RMSE is controlled within
0.0108 mm, even under the worst conditions. The experimental results
also confirm that 5-PDR has a good spot alignment ability in UWOC.
Instrument for fast whole-field peripheral refraction in the human eye
Authors: Fernandez Enrique J. , Sager Santiago , Lin Zhenghua , Hao Jiangdong , Roca Javier , Prieto Pedro M. , Yang Zhikuang , Lan Weizhong , Artal Pablo
Published: April 2022

An instrument for fast and objective measurement of the peripheral refraction in the human eye is presented. The apparatus permits the automatic estimation of both defocus and astigmatism at any retinal eccentricity by scanning a near infrared beam. The design includes a Hartmann-Shack wavefront sensor and a steering mirror, which operate in combination with a compounded eyepiece for wide field operation. The basic scanning protocol allows the estimation of refraction in a circular retinal patch of 50 deg diameter (±25 from central fixation) in 3 sec. Combined with additional fixation points, wider retinal fields can be sampled to achieve a whole field. The instrument underwent calibration and testing, and its performance for real eyes was assessed in 11 subjects of varying age and refraction. The results show high repeatability and precision. The instrument provides a new tool for the investigation of peripheral optics in the human eye.
Outage probability analysis of a vertical underwater wireless optical link subject to oceanic turbulence and pointing errors
Authors: Ijeh Ikenna Chinazaekpere , Khalighi Mohammad Ali , Elamassie Mohammed , Hranilovic Steve , Uysal Murat
Published: April 2022

The reliability of an underwater wireless optical communication (UWOC) network is seriously impacted by beam misalignment between transmitters (Txs) and receivers (Rxs). Also, the performance of UWOC systems can be affected by oceanic turbulence-induced fading due to fluctuations in the water refractive index as a result of variations in the pressure, water temperature, and salinity. In this work, we investigate the performance analysis of a vertical UWOC link subject to oceanic turbulence and pointing errors and further investigate the appropriate selection of link parameters to optimize link performance. This study is based on an accurate mathematical framework for link modeling while taking into account realistic Tx/Rx and channel parameters under different turbulence and beam misalignment conditions. We provide an analytical expression for calculating the link outage probability, whose accuracy is validated through numerical simulations. Last, the necessity of optimal Tx/Rx parameter selection to minimize the link outage is demonstrated. A laser beam is considered at the Tx, as well as an ultra-sensitive photodetector (silicon photo-multiplier) at the Rx to enable working at relatively long link ranges. The presented results give valuable insight into the practical aspects of deployment of UWOC networks.
Priors-guided convolutional neural network for 3D foveal avascular zone segmentation
Authors: Xu Qiuzhuo , Li Mingchao , Pan Nairong , Chen Qiang , Zhang Weiwei
Published: April 2022

The foveal avascular zone (FAZ) is sensitive to retinal pathological process in the macular fovea area. For the purpose of efficient FAZ 3D quantification, we firstly propose a priors-guided convolutional neural network (CNN) to provide a tailor-made solution for 3D FAZ segmentation for optical coherence tomography angiography (OCTA) images. Location and topology priors are taken into account. The random central crop module is utilized to restrict the region to be processed, while the non-local attention gates are contained in the network to capture long-range dependency. The topological consistency constraint is calculated on maximum and mean projection maps through persistent homology to keep topological correctness of the model’s prediction. Our method was evaluated on two OCTA datasets with 478 eyes and the experimental results demonstrate that our method can not only alleviate the over-segmentation prominently but also fit better on the contour of FAZ region.
Simulating a graphene-based acousto-plasmonic biosensor to eliminate the interference of surrounding medium
Authors: Mehrnegar Mohammad Mahdi , Darbari Sara , Moravvej Farshi Mohammad Kazem
Published: April 2022

The presence of species other than the target biomolecules in the fluidic analyte used in the refractive index biosensor based on the surface plasmon resonances (SPRs) can lead to measurement ambiguity. Using graphene-based acousto-plasmonic biosensors, we propose two methods to eliminate any possible ambiguity in interpreting the measured results. First, we take advantage of the dynamic tunability of graphene SPRs in the acousto-plasmonic biosensor with a surface acoustic wave (SAW) induced uniform grating, performing measurements at different applied voltages. Second, a single measurement employing a similar biosensor but with SAW-induced dual-segment gratings. The numerical results show the capability of both methods in decoupling the effect of the target analyte from the other species in the fluid, enabling interpreting the measurement results with no ambiguity. We also report the results of our numerical investigation on the effect of measuring parameters like the target layer effective refractive index and thickness, and the fluid effective refractive index, in addition to the controlling parameters of the proposed acousto-plasmonic biosensor, including graphene Fermi energy and electrical signaling on the sensing characteristics. Both types of proposed biosensors show promising features for developing the next generation lab-on-a-chip biosensors with minimal cross-sensitivities to non-target biomolecules.
Computational ghost imaging encryption with a pattern compression from 3D to 0D
Authors: Zheng Peixia , Ye Zhiyuan , Xiong Jun , Liu Hong-chao
Published: April 2022

The principle of computational ghost imaging (GI) offers a potential application in optical encryption. Nevertheless, large numbers of keys composed of random or specific patterns set an obstacle to its application. Here, we propose a series of pattern compression methods based on computational GI, in which thousands of patterns are replaced by a single standard image (i.e., two-dimensional data), a sequence of numbers (i.e., one-dimensional data) or the fractional part of an irrational number (i.e., zero-dimensional data). Different pattern compression methods are tested in both simulations and experiments, and their error tolerances in encryption are further discussed. Our proposed methods can greatly reduce the pattern amount and enhance encryption security, which pushes forward the application of computational GI, especially in optical encryption.
Ghost imaging through scattering medium by utilizing scattered light: publisher’s note
Authors: Lin Li-Xing , Cao Jie , Zhou Dong , Cui Huan , Hao Qun
Published: April 2022

This publisher’s note contains a correction to [Opt. Express 30(7), 11243 (2022).10.1364/OE.453403]. The article was corrected online on 8 June 2022.
Dual-comb absorption spectroscopy of molecular CeO in a laser-produced plasma
Authors: Rhoades Ryan T. , Weeks Reagan R. D. , Erickson Seth E. , Lecaplain Caroline , Harilal Sivanandan S. , Phillips Mark C. , Jason Jones R.
Published: April 2022

Broadband and high-resolution absorption spectra of molecular cerium oxide (CeO) are obtained in a laser-produced plasma using dual-comb spectroscopy. Simultaneous measurements of Ce and CeO are used to probe time-resolved dynamics of the system. A spectral resolution of 1.24 GHz (2.4 pm) over a bandwidth of 378.7–383.7 THz (781.1–791.5 nm) allows simultaneous detection of hundreds of closely spaced rotational transitions in complex CeO bands.
Subsurface damage layer of bulk single-crystal potassium dihydrogen phosphate (KDP) after SPDT: studied by the grazing incidence X-ray diffraction technique
Authors: Zhang Y. , Fan Q. C. , Gao W. , Wang C. , Ji F.
Published: April 2022

This work proposes a novel way of the subsurface damage layer characterization for bulk single-crystal optical material, based on the X-ray grazing incidence technique (GIXRD). The result shows that the subsurface damage layer of bulk single-crystal potassium dihydrogen phosphate (KDP) mainly consists of polycrystalline KDP and bulk single-crystal matrix after single-point diamond turning (SPDT). Meanwhile, it is found that the polycrystalline KDP presents some kinds of preferred orientations, which depend on the SPDT surfaces and SPDT track
u
. For example, the polycrystalline texture of (010) SPDT surface is
p
(103)//
u
and
p
(204)//
u
, while the polycrystalline texture of (111), I-type and II-type SPDT surfaces are
p
(312)//
u
,
p
(332)//
u
and
p
(202)//
u
, respectively. These findings allow us to further understand the subsurface damage layer of bulk single-crystal KDP after SPDT.
Emerging Optical Materials, Devices and Systems for Photonic Neuromorphic Computing feature issue: publisher’s note
Authors: Hurtado Antonio , Romeira Bruno , Shastri Bhavin , Cheng Zengguang , Buckley Sonia
Published: April 2022

This publisher’s notes amends the title of [Opt. Mater. Express 12, 1214 (2022)10.1364/OME.451016].
Multiphoton ionization of standard optical fibers
Authors: Ferraro M. , Mangini F. , Sun Y. , Zitelli M. , Niang A. , Crocco M. C. , Formoso V. , Agostino R. G. , Barberi R. , De Luca A. , Tonello A. , Couderc V. , Babin S. A. , Wabnitz S.
Published: April 2022

Atoms ionization by the simultaneous absorption of multiple photons has found applications in fiber optics, where it leads to unique nonlinear phenomena. To date, studies of the ionization regime have been limited to gas-filled hollow-core fibers. Here, we investigate multiphoton ionization of standard optical fibers, where intense laser pulses ionize the atoms constituting the fiber structure itself, instead of that of the filling gas. We characterize material modifications produced by optical breakdown. Their formation affects laser beam dynamics over hours long temporal scales. The damage features are studied by means of optical microscopy and X-ray microtomography. In the framework of glass photonics, our results pave the way for a novel glass waveguide micromachining technique.
Wideband diffusion metabsorber for perfect scattering field reduction
Authors: Song Zicheng , Min Pingping , Zhu Jiaqi , Yang Lei , Han Lin Feng
Published: April 2022

Both absorption and diffuse reflection can effectively suppress microwave backward reflection. However, the challenge of designing wideband absorptive elements with anti-phase reflection hinders the simultaneous working of the two principles. With aid of the wideband characteristic of bilateral complementary structure, we propose a strategy to design wideband absorptive elements with large reflection phase differences. For proof of concept, the proposed elements are arranged in a rectangular grid by optimizing scattering field distribution. The proposed diffusion metabsorber achieves over 20-dB scattering field reduction in the range of 8.5–20.3 GHz with good polarization stability and high angular insensitivity of up to

±
40
°

, which has been verified by real experiments. Furthermore, the proposed design strategy exhibits the potential to further reduce electromagnetic wave reflection, and the optical transparent characteristic is promising for window applications.
Chief Digital Officer (CDO): Literaturanalyse und Handlungsempfehlungen für die Praxis
Authors: Hermes Anna , Riedl René
Published: April 2022

Um im Zeitalter der Digitalisierung wettbewerbsfähig zu bleiben und um die digitale Transformation sicherzustellen, schaffen Unternehmen zunehmend die Stelle eines Chief Digital Officer (CDO). Um Unternehmen bei Entscheidungen rund um die Ein- und Ausrichtung der Position des CDOs zu unterstützen, haben wir in folgenden Bereichen die Fachliteratur systematisch analysiert: (1) Gründe für eine CDO-Position, (2) Aufgaben des CDOs, (3) Anforderungen an einen CDO sowie (4) Abgrenzung zwischen CDO und Chief Information Officer (CIO). In der Fachliteratur wird insbesondere die strategische Führung bei Veränderungen als Grund für die Schaffung einer CDO-Position genannt. Damit einhergehend ist die Digitalisierung und das Implementieren der digitalen Transformation die am häufigsten genannte Aufgabe sowie das strategische und geschäftsorientierte Denken die am häufigsten genannte Anforderung. In der Abgrenzung des CDOs zum CIO wird der CDO primär als Stratege und der CIO in erster Linie als Verantwortlicher für die IT-Infrastruktur gesehen. Basierend auf den Ergebnissen der Literaturanalyse beschreiben wir Handlungsempfehlungen für Entscheidungsträger in der Praxis, die sich eine Übersicht über die möglichen Ein- und Ausrichtungen der CDO-Position schaffen wollen.
Das Zusammenspiel von Chief Executive Officer und Chief Digital Officer bei der digitalen Transformation
Authors: Hess Thomas , Sciuk Christian
Published: April 2022

Die schnellen Entwicklungs- und Diffusionszyklen von digitalen Technologien stellen Organisationen branchenübergreifend vor enorme Herausforderungen. Im Zuge ihrer digitalen Transformation müssen sich Unternehmen Gedanken machen, wie sie die Potenziale digitaler Technologien bestmöglich nutzen. Um diesen Anforderungen zu entsprechen, werden zunehmend Chief Digital Officers etabliert. Daneben zeigt sich in der Praxis, dass der Chief Executive Officer aufgrund der hohen strategischen Relevanz auch maßgeblich an der Steuerung der digitalen Transformation beteiligt ist. Zu der genauen Rolle des Chief Executive Officers bei der digitalen Transformation ist bisher jedoch wenig bekannt. Insbesondere gibt es noch keine Untersuchungen zu seiner Zusammenarbeit mit dem Chief Digital Officer. Anhand von vier Fallstudien zeigen wir explorativ auf, wie die Aufgabenverteilung und Interaktion von Chief Executive Officer und Chief Digital Officer in der Praxis ausgestaltet ist. Unsere Ergebnisse weisen darauf hin, dass der Chief Executive Officer oftmals die Vision und die strategischen Vorgaben für die digitale Transformation festlegt. Zudem ist er an ausgewählten Themen aktiv beteiligt. Die konkrete Umsetzung der Leitlinien liegt hingegen beim Chief Digital Officer. Dabei hat er häufig einen gewissen Ermessensspielraum und kann ferner auch eigene Projekte unabhängig vorantreiben. Schließlich hat sich gezeigt, dass eine enge Abstimmung von Chief Executive Officer und Chief Digital Officer Grundvoraussetzung ist, um die digitale Transformation zielführend zu steuern.
A comparative approach to stabilizing mechanisms between discrete- and continuous-time consumer-resource models
Authors: Singh Abhyudai
Published: April 2022

There is rich literature on using continuous-time and discrete-time models for studying population dynamics of consumer-resource interactions. A key focus of this contribution is to systematically compare between the two modeling formalisms the stabilizing/destabilizing impacts of diverse ecological processes that result in a density-dependent consumer attack rate. Inspired by the Nicholson-Bailey/Lotka-Volterra models in discrete-time/continuous-time, respectively, we consider host-parasitoid interactions with an arbitrary parasitoid attack rate that is a function of both the host/parasitoid population densities. Our analysis shows that a Type II functional response is stabilizing in both modeling frameworks only when combined with other mechanisms, such as mutual interference between parasitoids. A Type III functional response is by itself stabilizing, but the extent of attack-rate acceleration needed is much higher in the discrete-time framework, and its stability regime expands with increasing host reproduction. Finally, our results show that while mutual parasitoid interference can stabilize population dynamics, cooperation between parasitoids to handle hosts is destabilizing in both frameworks. In summary, our comparative analysis systematically characterizes diverse ecological processes driving stable population dynamics in discrete-time and continuous-time consumer-resource models.
A new 10-D hyperchaotic system with coexisting attractors and high fractal dimension: Its dynamical analysis, synchronization and circuit design
Authors: Benkouider Khaled , Bouden Toufik , Sambas Aceng , Lekouaghet Badis , Mohamed Mohamad Afendee , Ibrahim Mohammed Sulaiman , Mamat Mustafa , Ibrahim Mohd Asrul Hery , Ahmad Muhammad Zaini
Published: April 2022

This work introduce a new high dimensional 10-D hyperchaotic system with high complexity and many of coexisting attractors. With the adjustment of its parameters and initial points, the novel system can generate periodic, quasi-periodic, chaotic, and hyperchaotic behaviours. For special values of parameters, we show that the proposed 10-D system has a very high Kaplan-Yorke fractal dimension, which can reach up to 9.067 indicating the very complexity of the 10-D system dynamics. In addition, the proposed system is shown to exhibit at least six varied attractors for the same values of parameters due to its multistability. Regions of multistability are identified by analysing the bifurcation diagrams of the proposed model versus its parameters and for six different values of initial points. Many of numerical plots are given to show the appearance of different dynamical behaviours and the existence of multiple coexisting attractors. The main problem with controlling chaos/hyperchaos systems is that they are not always fully synchronized. therefore, some powerful synchronization techniques should be considered. The synchronization between the high-dimensional 10-D system and a set of three low-dimensional chaotic and hyperchaotic systems is proposed. Ten control functions are designed using the active control method, ensuring synchronisation between the collection of systems and the 10-D hyperchaotic system. Finally, using Multisim 13.0 software to construct the new system’s electronic circuit, the feasibility of the new system with its extremely complicated dynamics is verified. Therefore, the novel 10-D hyperchaotic system can be applied to different chaotic-based application due to its large dimension, complex dynamics, and simple circuit architecture.
Semantics of European poetry is shaped by conservative forces: The relationship between poetic meter and meaning in accentual-syllabic verse
Authors: Šeļa Artjoms , Plecháč Petr , Lassche Alie
Published: April 2022

Recent advances in cultural analytics and large-scale computational studies of art, literature and film often show that long-term change in the features of artistic works happens gradually. These findings suggest that conservative forces that shape creative domains might be underestimated. To this end, we provide the first large-scale formal evidence of the association between poetic meter and semantics in 18-19th century European literatures, using Czech, German and Russian collections with additional data from English poetry and early modern Dutch songs. Our study traces this association through a series of unsupervised classifications using the abstracted semantic features of poems that are inferred for individual texts with the aid of topic modeling. Topics alone enable recognition of the meters in each observed language, as may be seen from the same-meter samples clustering together (median Adjusted Rand Index between 0.48 and 1 across traditions). In addition, this study shows that the strength of the association between form and meaning tends to decrease over time. This may reflect a shift in aesthetic conventions between the 18th and 19th centuries as individual innovation was increasingly favored in literature. Despite this decline, it remains possible to recognize semantics of the meters from past or future, which suggests the continuity in meter-meaning relationships while also revealing the historical variability of conditions across languages. This paper argues that distinct metrical forms, which are often copied in a language over centuries, also maintain long-term semantic inertia in poetry. Our findings highlight the role of the formal features of cultural items in influencing the pace and shape of cultural evolution.
Health risks to children from exposure to fecally-contaminated recreational water
Authors: Wade Timothy J. , Arnold Benjamin F. , Schiff Ken , Colford John M. , Weisberg Stephen B. , Griffith John F. , Dufour Alfred P.
Published: April 2022

Background

Children may be at higher risk for swimming-associated illness following exposure to fecally-contaminated recreational waters. We analyzed a pooled data set of over 80,000 beachgoers from 13 beach sites across the United States to compare risks associated with the fecal indicator bacteria Enterococcus spp. (measured by colony forming units, CFU and quantitative polymerase chain reaction cell equivalents, qPCR CE) for different age groups across different exposures, sites and health endpoints.

Methods

Sites were categorized according to the predominant type of fecal contamination (human or non-human). Swimming exposures of varying intensity were considered according to degree of contact and time spent in the water. Health endpoints included gastrointestinal and respiratory symptoms and skin rashes. Logistic regression models were used to analyze the risk of illness as a function of fecal contamination in water as measured by Enterococcus spp. among the exposed groups. Non-swimmers (those who did not enter the water) were excluded from the models to reduce bias and facilitate comparison across groups.

Results

Gastrointestinal symptoms were the most sensitive health endpoint and strongest associations were observed with Enterococcus qPCR CE at sites impacted by human fecal contamination. Under several exposure scenarios, associations between illness and Enterococcus spp. levels were significantly higher among children compared to adolescents and adults. Respiratory symptoms were also associated with Enterococcus spp. exposures among young children at sites affected by human fecal sources, although small sample sizes resulted in imprecise estimates for these associations.

Conclusion

Under many exposure scenarios, children were at higher risk of illness associated with exposure to fecal contamination as measured by the indicator bacteria Enterococcus spp. The source of fecal contamination and the intensity of swimming exposure were also important factors affecting the association between Enterococcus spp. and swimming-associated illness.
Soluble tumor necrosis factor receptor 2 is associated with progressive diabetic kidney disease in patients with type 2 diabetes mellitus
Authors: Wu Tsung-Hui , Chang Li-Hsin , Chu Chia-Huei , Hwu Chii-Min , Chen Harn-Shen , Lin Liang-Yu
Published: April 2022

Background

Chronic low-grade inflammation is considered one of the major mechanisms for the progression of diabetic kidney disease. We investigated the prognostic value of circulating soluble tumor necrosis factor receptor 2 (sTNFR2) for early nephropathy in patients with type 2 diabetes.

Materials and methods

A total of 364 patients with type 2 diabetes and an estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73m2were followed up for a median of 4 years. Renal outcomes were defined as a composite of either or both a >30% decline in the eGFR and/or albuminuria stage progression determined with consecutive tests.

Results

Seventy-three patients developed renal composite events. Serum concentrations of sTNFR2 were strongly associated with the risk of renal function decline and progressive changes in albuminuria. Through a receiver operating characteristic curve analysis, a serum sTNFR2 level of 1.608 ng/mL was adopted as the discriminator value for predicting renal outcomes (area under the curve 0.63, 95% confidence interval 0.57–0.70, p < 0.001), yielding a sensitivity of 75.3% and a specificity of 51.2%. The association of sTNFR2 levels ≥1.608 ng/mL to renal outcomes was significant after adjusting for relevant variables (hazard ratio 2.27, 95% confidence interval 1.23–4.20, p = 0.009) and remained consistent across subgroups stratified by age, sex, systolic blood pressure, eGFR, albuminuria, and the use of renin-angiotensin system blockers.

Conclusions

Higher circulating levels of sTNFR2 are independently associated with an eGFR decline and progressive albuminuria in patients with type 2 diabetes.