bluuebunny/crossref_metadata_2025 huggingface dataset:
The Association of Preoperative Frailty and Postoperative Delirium: A Meta-analysis
Authors: Gracie Thomas J. , Caufield-Noll Christine , Wang Nae-Yuh , Sieber Frederick E.
Published: July 2021

BACKGROUND:

Both frailty and postoperative delirium (POD) are common in elective surgical patients 65 years of age and older. However, the association between preoperative frailty and POD remains difficult to characterize owing to the large number of frailty and POD assessment tools used in the literature, only a few of which are validated. Furthermore, some validated frailty tools fail to provide clear score cutoffs for distinguishing frail and nonfrail patients. We performed a meta-analysis to estimate the relationship between preoperative frailty and POD.

METHODS:

We searched several major databases for articles that investigated the relationship between preoperative frailty and POD in patients with mean age ≥65 years who were undergoing elective, nonemergent inpatient surgery. Inclusion criteria included articles published in English no earlier than 1999. Both preoperative frailty and POD must have been measured with validated tools using clear cutoff scores for frailty and delirium. Articles were selected and data extracted independently by 2 researchers. Risk of bias (ROBINS-I) and presence of confounders were summarized. Odds ratios (ORs) for POD associated with frailty relative to nonfrailty were computed with adjusted ORs when available. Original estimates were pooled by random effects analysis. Statistical significance was set at 2-sided P < .05.

RESULTS:

Nine studies qualified for meta-analysis. The Fried score or a modified version of it was used in 5 studies. Frailty prevalence ranged from 18.6% to 56%. Delirium was assessed with the Confusion Assessment Method (CAM) or Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) in 7 studies, Delirium Observation Scale in 1 study, and Intensive Care Delirium Screening Checklist in 1 study. The incidence of POD ranged from 7% to 56%. ROBINS-I risk of bias was low in 1 study, moderate in 4 studies, serious in 3 studies, and critical in 1 study. Random effects analysis (n = 794) of the OR for POD in frail versus nonfrail patients based on adjusted OR estimates was significant with an OR of 2.14 and a 95% confidence interval of 1.43–3.19. The I
2 value was in the low range at 5.5, suggesting small variability from random effects. Funnel-plot analysis did not definitively support either the presence or absence of publication bias.

CONCLUSIONS:

This meta-analysis provides evidence for a significant association between preoperative frailty and POD in elective surgical patients age 65 years or older.
The dorsal blastopore lip is a source of signals inducing planar cell polarity in the Xenopus neural plate
Authors: Mancini Pamela , Ossipova Olga , Sokol Sergei Y.
Published: July 2021

Coordinated polarization of cells in the tissue plane, known as planar cell polarity (PCP), is associated with a signaling pathway critical for the control of morphogenetic processes. Although the segregation of PCP components to opposite cell borders is believed to play a critical role in this pathway, whether PCP derives from egg polarity or preexistent long-range gradient, or forms in response to a localized cue, remains a challenging question. Here we investigate the Xenopus neural plate, a tissue that has been previously shown to exhibit PCP. By imaging Vangl2 and Prickle3, we show that PCP is progressively acquired in the neural plate and requires a signal from the posterior region of the embryo. Tissue transplantations indicated that PCP is triggered in the neural plate by a planar cue from the dorsal blastopore lip. The PCP cue did not depend on the orientation of the graft and was distinct from neural inducers. These observations suggest that neuroectodermal PCP is not instructed by a preexisting molecular gradient but induced by a signal from the dorsal blastopore lip.
HIPEC-Induced Acute Kidney Injury: A Retrospective Clinical Study and Preclinical Model
Authors: Liesenfeld Lukas F. , Wagner Benedikt , Hillebrecht H. Christian , Brune Maik , Eckert Christoph , Klose Johannes , Schmidt Thomas , Büchler Markus W. , Schneider Martin
Published: July 2021

Background

Hyperthermic intraperitoneal chemotherapy (HIPEC) combined with cytoreductive surgery (CRS) is the treatment of choice for selected patients with peritoneal malignancies. HIPEC is accompanied by moderate-to-high patient morbidity, including acute kidney injury. The significance of nephrotoxic agents such as cisplatin versus hyperthermia in HIPEC-induced nephrotoxicity has not been defined yet.

Patients and Methods

A total of 153 patients treated with HIPEC were divided into groups with (AKI+) and without (AKI−) kidney injury. Laboratory parameters and data concerning patient demographics, underlying disease, surgery, complications, and HIPEC were gathered to evaluate risk factors for HIPEC-induced AKI. A preclinical mouse model was applied to assess the significance of cisplatin and hyperthermia in HIPEC-induced AKI, as well as protective effects of the cytoprotective agent amifostine.

Results

AKI occurred in 31.8% of patients undergoing HIPEC. Treatment with cisplatin-containing HIPEC regimens represented a major risk factor for HIPEC-related AKI (p < 0.001). Besides, angiotensin receptor blockers and increased preoperative creatinine and urea levels were independent risk factors for AKI after HIPEC. In a preclinical mouse model, intraperitoneal perfusion with cisplatin induced AKI, whereas hyperthermia alone, or in combination with cisplatin, did not induce or enhance renal injury. Amifostine failed to confer nephroprotective effects in a miniaturized HIPEC model.

Conclusions

AKI is a frequent complication after HIPEC. The risk of renal injury is particularly high in patients treated with cisplatin-containing HIPEC regimens. Hyperthermic perfusion of the abdomen by itself does not seem to induce or aggravate HIPEC-induced renal injury.
Annotating clause boundary labels to the written composition corpus of Japanese elementary and junior high school students
Authors: Imada Mizuho , Tagawa Takumi , Moon Chang-Yun , Nasu Akio
Published: July 2021

To evaluate the development of children’s writing ability, it is necessary not only to examine quantitative indices such as the dependency distance, but also to inquiry the types of structures they use. We conducted clause boundary labeling using Support Vector Machine (SVM) on a corpus of Japanese students' compositions to investigate the change in the tendency of clause use with the progression of school age. The analysis of clause label frequency per sentence exhibited an increase in attributive clauses, nominal clauses, quotation clauses, and continuous clauses, and a decrease in parallel clauses, conditional clauses, reason clauses, time clauses, indirect interrogative clauses, and main clauses. The analysis of dependency distance demonstrated that most of the clauses that increased had short dependency distances, while most of the clauses that decreased had long dependency distances, and that the frequency of clauses with small dependency distances increased relatively with increasing school age. In addition, there was a shift in clause selection among functionally similar clauses, such as from “-te” to continuous forms, from “-tara” to “-ba”, and from “-kedo” and “-keredo” to “-ga”. These results suggest a change in the children’s lexical and grammatical choices, from coordinate to subordinate structures, and from spoken to written vocabulary.
Semen biomarker TEX101 predicts sperm retrieval success for men with testicular failure
Authors: Jarvi Keith , Schlegel Peter , Schiza Christina , Drabovich Andrei , Lau Susan , Soosaipillai Antoninus , Korbakis Dimitrios , Brinc Davor , Mullen Brendan , Diamandis Eleftherios
Published: July 2021

Background: 

Azoospermia could be due to either obstruction (obstructive azoospermia: OA) or spermatogenic failure (non-obstructive azoospermia: NOA). Close to 50% of men with NOA have small pockets of sperm in the testis which could be retrieved surgically and then injected into oocytes in a program of intra-cytoplasmic sperm insertion. Presently, there are no accepted non-invasive tests allowing clinicians to predict the success rates of sperm retrieval. Previously, we have identified a germ cell-specific protein TEX101 in semen found in the primary spermatocytes and more mature sperm forms, but not in spermatogonia, Sertoli or Leydig cells. We hypothesized that the semen concentration of TEX101 could be used to predict sperm production in men with NOA. 

Methods:  

This was a prospective cohort study on men with NOA being treated at a male infertility centre.  

Men with NOA planning sperm retrieval provided 1–3 semen samples prior to surgery. 

Semen TEX101 concentrations were measured by an in-house-developed ELISA assay and compared with the results of the surgery to retrieve sperm.  

Results: 

20/60 karyotypically normal men with NOA had semen TEX101 < LOD (<0.2ng/mL).  Of these, 0% had successful sperm retrieval(0-17%: 95% CI) .  In contrast, of the 40 men with TEX101> LOD, sperm was found in 50% (34-66%: 95% CI, sig diff. Fisher’s exact test, p<0.05).

Conclusions: 

Undetectable (<0.2 ng/mL) semen TEX101 is highly predictive of sperm retrieval failure for karyotypically normal men with NOA and is the single strongest non-invasive predictor of sperm retrieval failure reported so far. Semen TEX101 concentration will help couples decide their individual chances of successful sperm retrieval.
Perception and awareness of COVID-19 among health science students and staff of Kuwait University: An online cross-sectional study
Authors: Alali Walid , AlFouzan Wadha , Alajmi Dhuha , Al-Tawalah Haya , Kheirallah Khalid , Yimer Getnet
Published: July 2021

Background: Coronavirus disease 2019 (COVID-19) pandemic is unprecedented. Health science students are the future frontliners to fight pandemics. Awareness and perception toward COVID-19 among health science students and staff at Kuwait University was assessed.

Methods: Between June and July 2020, an online questionnaire was distributed to all students and staff at HCS.  The questionnaire was divided into six sections: socio-demography, risk and awareness, preparedness and prevention, source of information, policies, and social stigma. 

Results: A total of 592 students and 162 staff completed the questionnaire. The prevalence of self-reported chronic condition among students and staff was 14.0% and 19.1%, respectively. Moreover, self-reported COVID-19 prevalence among students and staff was 2.7% and 1.2%, respectively. Interestingly, 54% of students and 38.3% of staff reported that they knew someone within their immediate social environment who have been/are infected with SARS-CoV-2. Among students, 92.4% wore face mask in indoor places (outside of their home) ‘often/all the time’ compared to wearing it outdoors (69.3%); whereas, for staff, it was more common to wear it outdoor than in indoor places (75.9% vs. 81.5%). Willingness to take COVID-19 vaccine was indicated by 50% of students ‘strongly agreed’ and an additional 25.8% agreed to taking it. Interest vaccine uptake was lower among staff (28.4% and 34.6% strongly agreed or agreed, respectively). Participants strongly agreed or agreed (72.5% and 19.6% of students as well as 68.5% and 22.2% of staff) that wearing face mask in public should be obligatory. More than 18% of students and staff indicated that they would avoid contact with COVID-19 infected people.

Conclusions: Responses of students and staff were mostly similar and showed that they follow precautionary measures to control spread of COVID-19, understand the viral transmission risk, and willing to raise awareness to reduce social stigma.
Developing a programme theory for a transdisciplinary research collaboration: Complex Urban Systems for Sustainability and Health
Authors: Moore Gemma , Michie Susan , Anderson Jamie , Belesova Kristine , Crane Melanie , Deloly Clément , Dimitroulopoulou Sani , Gitau Hellen , Hale Joanna , Lloyd Simon J. , Mberu Blessing , Muindi Kanyiva , Niu Yanlin , Pineo Helen , Pluchinotta Irene , Prasad Aarathi , Roue-Le Gall Anne , Shrubsole Clive , Turcu Catalina , Tsoulou Ioanna , Wilkinson Paul , Zhou Ke , Zimmermann Nici , Davies Michael , Osrin David
Published: July 2021

Background: Environmental improvement is a priority for urban sustainability and health and achieving it requires transformative change in cities. An approach to achieving such change is to bring together researchers, decision-makers, and public groups in the creation of research and use of scientific evidence.

Methods: This article describes the development of a programme theory for Complex Urban Systems for Sustainability and Health (CUSSH), a four-year Wellcome-funded research collaboration which aims to improve capacity to guide transformational health and environmental changes in cities.

Results: Drawing on ideas about complex systems, programme evaluation, and transdisciplinary learning, we describe how the programme is understood to “work” in terms of its anticipated processes and resulting changes. The programme theory describes a chain of outputs that ultimately leads to improvement in city sustainability and health (described in an ‘action model’), and the kinds of changes that we expect CUSSH should lead to in people, processes, policies, practices, and research (described in a ‘change model’).

Conclusions: Our paper adds to a growing body of research on the process of developing a comprehensive understanding of a transdisciplinary, multiagency, multi-context programme. The programme theory was developed collaboratively over two years. It involved a participatory process to ensure that a broad range of perspectives were included, to contribute to shared understanding across a multidisciplinary team. Examining our approach allowed an appreciation of the benefits and challenges of developing a programme theory for a complex, transdisciplinary research collaboration. Benefits included the development of teamworking and shared understanding and the use of programme theory in guiding evaluation. Challenges included changing membership within a large group, reaching agreement on what the theory would be ‘about’, and the inherent unpredictability of complex initiatives.
Strategic planning in the public sector of the economy
Authors: Sil'vestrov Sergey , Starovoytov Vladimir , Bauer Vladimir , Selivanov Aleksandr , Lepskiy Vladimir , Raykov Aleksandr , Lipina Svetlana , Muntiyan Valeriy , Polyanin Andrey , Troshin Dmitriy , Andrianov Konstantin , Bocharova Lina , Pobyvaev Sergey , Sorokina Natal'ya , Erina Nelli , Kotova Natal'ya , Smirnov Vladimir , Vedernikova Anna
Published: July 2021

This collective monograph continues a series of scientific studies and publications on the problems of strategic planning, which have been carried out for several years at the Financial University under the Government of the Russian Federation with the involvement of specialists from other scientific and educational organizations. A series of research papers in 2017-2019 was devoted to the analysis of strategic development risks and the analysis of global strategic planning practice, the general methodology of strategic planning and forecasting (including in the context of ensuring Russia's economic security), the approach to the formation of life cycles of preparation and revision of strategic planning documents and their comparative analysis, the experience of coordinating budget, project and process types of management and financing, monitoring risks and threats, the use of new information tools in the strategic planning complex, including blockchain, and also naturally develops such aspects of previous research as analysis of world practice, coordination of budget, project and process types of management and financing, the use of information technologies. However, at the same time, a special task was set — to approach a comprehensive analysis of the strategic planning process as a whole, especially to study its documentary support as the core of the organization of this process and the implementation of its results in the practice of public administration, as well as to analyze the scientific support of strategic planning as an essential aspect of all strategic planning and strategic management activities in the entirety of its aspects (goal setting, forecast, design, programming, planning, control and audit).
It is intended for specialists from the humanities, natural sciences and technical fields of knowledge focused on management and development problems, for undergraduates and postgraduates, as well as for a wide audience of management practitioners, including those related to strategic planning processes in the public sector.
State and municipal administration
Authors: Abramov Ruslan , Muhaev Rashid
Published: July 2021

This textbook reveals all aspects of the theoretical and applied analysis of the actual problems of modern state and municipal management, which is based on the generalization of the world and domestic experience of the functioning of public administration systems. Within the framework of the communicative paradigm of public administration, the system, mechanism, practices, apparatus of public administration of foreign countries, styles of public decision-making and technologies of their implementation in different models of public administration are considered. The novel of the textbook is a comparative analysis of threats, challenges and responses that determine the modern transformations of the administrative sphere and change management technologies in the field of public administration, as well as markers for quantifying the effectiveness of public management systems in the information society.
Meets the requirements of the federal state educational standards of higher education of the latest generation.
For bachelors of higher educational institutions studying in the areas of training 38.03.04 "State and municipal management", 41.03.04 "Political Science", 38.03.02 "Management".
Narrative summaries in Acts of the Apostles. Reading of the first summary account (2:42–47)
Authors: Celarc Matjaz
Published: July 2021

The article presents the reading of the first summary narrative account in the Acts of the Apostles by adopting Point of View Analysis together with the Intertextual Reading of the Isaianic prophecies. The articles thus shed light on the nascent Christian community that enjoys God’s blessing through welcoming homes and table-fellowship among the community members.
Graphical Convergence of Subgradients in Nonconvex Optimization and Learning
Authors: Davis Damek , Drusvyatskiy Dmitriy
Published: July 2021

We investigate the stochastic optimization problem of minimizing population risk, where the loss defining the risk is assumed to be weakly convex. Compositions of Lipschitz convex functions with smooth maps are the primary examples of such losses. We analyze the estimation quality of such nonsmooth and nonconvex problems by their sample average approximations. Our main results establish dimension-dependent rates on subgradient estimation in full generality and dimension-independent rates when the loss is a generalized linear model. As an application of the developed techniques, we analyze the nonsmooth landscape of a robust nonlinear regression problem.
Clinical and cost efficacy of advanced wound care matrices in the treatment of venous leg ulcers: a systematic review
Authors: Massand Sameer , Lewcun Joseph A , LaRosa Charles A
Published: July 2021

Background:

Venous leg ulcers (VLUs) are hard-to-heal, recurrent and challenging to treat. Advanced wound care matrices (AWCMs) have been developed to supplement conventional therapies. These costly AWCMs warrant careful comparison as healthcare expenditures are subjected to increasing scrutiny.

Aim:

This study was designed to compare AWCMs in their ability to heal VLUs and their cost efficacy through a systematic review of randomised controlled trials (RCTs).

Method:

An organised search of Medline, Cochrane Library, Central and CINAHL databases identified RCTs that compared AWCMs to standard compression therapy in the healing of VLUs. Bias was assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. Eight studies analysing bilayered skin substitute (BSS) (Apligraf), dehydrated human amnion/chorion membrane (dHACM) (Epifix), human fibroblast-derived dermal substitute (HFDDS) (Dermagraft), extracellular wound matrix (ECM) (Oasis), advanced matrix (AM) (Talymed) and matrix wound dressing (MWD) (Promogran) met the inclusion criteria.

Results:

Four studies reported significant improvement over standard therapy: BSS, dHACM, ECM and AM. Incremental cost per additional successful treatment was determined for each trial, ranging from $2593 (MWD) to $210,800 (HFDDS).

Conclusion:

Our consolidated analysis of eight major RCTs of AWCMs in the treatment of VLUs revealed a great variation in clinical and cost efficacy among these products. The included trials were inconsistent in methodology, and these limitations should be noted, but, in the absence of RCTs to compare these products, our systematic review may serve as a guide for practitioners who seek to optimise wound healing while considering cost efficacy.
Surgical reconstruction of pilonidal sinus disease with concomitant extracellular matrix graft placement: a case series
Authors: Chaffin Abigail E , Dowling Shane G , Kosyk Mychajlo S , Bosque Brandon A
Published: July 2021

Background:

Pilonidal sinus disease (PSD) is a chronic inflammatory disease affecting the soft tissue of the sacrococcygeal region and remains a challenging disease for clinicians to treat. The optimal treatment for PSD remains controversial and recent reports describe several different surgical approaches offering different benefits. Approximately 40% of initial incision and drainage cases require subsequent surgery. Due to high recurrence rates and postoperative complications, a more complex revision surgery involving a flap reconstruction may be required. We hypothesised that the combination of an extracellular matrix (ECM) graft with tissue flap reconstruction may decrease the postoperative complications and recurrence rates for PSD.

Method:

We report a retrospective case series using a surgical flap reconstruction with concomitant implantation of an ovine forestomach ECM graft under a fasciocutaneous flap with an off-midline closure for recurrent PSD, where previously surgical intervention had failed due to wound dehiscence and/or recurrent disease.

Results:

The case series included six patients. After three weeks, all patients except one were fully healed, and the sixth was fully healed by week 4; all wounds remained fully healed at 12 weeks. All patients achieved good cosmesis and were able to return to normal function without any residual symptoms.

Conclusion:

This pilot case series explored augmenting a flap reconstruction for complex PSD with advanced ECM graft materials, demonstrating that it may improve outcomes and minimise typical complications seen in flap closure, such as inflammation, infection, haematoma/seroma and hypoperfusion. Although the study had a limited number of participants, long-term outcomes were promising and suggest that further studies are warranted.
Fluid Stiction From a Contact Condition
Authors: Ćerimagić Remzija , Johansen Per , Andersen Torben Ole , Scheidl Rudolf
Published: July 2021

This paper considers modeling of fluid stiction between two separating plates that start from a mechanical contact condition. Published experimental work on initially contacting plates showed significant variations in stiction force peak values. In order to describe the observed strong force variations with mathematical models, the models should be quite sensitive to some of the input parameters of the stiction problem. The model in this paper assumes that small air bubbles are entrapped between the contact areas of the asperity peaks and that the fluid film flow between the cavitation bubbles is guided by Reynolds equation. The proposed model exhibits high sensitivity to initial bubble size and initial contact force compared to state-of-the art models. A delay of about 1 ms in the simulated stiction force evolution and the experiments was found. Potential causes for this discrepancy are discussed at the end of this paper and an outlook to future work, which can reduce the discrepancy between the model and experimental results is given.
Internet access standards: dissemination of the Integrated Services Digital Network in Spain, 1984-2005
Authors: Calvo Angel
Published: July 2021

This article aims to narrate the birth and evolution of the Integrated Services Digital Network (ISDN) in Spain with an essentially descriptive methodology, from an interdisciplinary perspective and from varied sources. The study aims to investigate the forms of the transition from a conceptual or engineering phase to the market in a standard of Internet access and, at the same time, in the different patterns of technological innovation and the factors that motivate them. It tries to verify if the own nature of the techniques, the degree of diffusion of the previous technologies, the technological level -digitalization- and the structure of market of the telecommunications — continued existence of the monopoly of the historical operator National Telephone Company of Spain — had a significant impact on the inequality of penetration with respect to other countries. The research authorizes to conclude that a very heterogeneous combination of factors caused that leading countries in the diffusion of a technology did not achieve that leading role in the diffusion of other technologies.
Academic patents and entrepreneurial intention. To what extent are other knowledge transfer mechanisms affected in a Mexican university?
Authors: Calderón María Guadalupe , Perez Pilar
Published: July 2021

This research aims to expand the explanations about the debate on academic entrepreneurship and other knowledge transfer mechanisms, to respond to what extent entrepreneurial intention affects the diffusion and dissemination of knowledge in a Mexican university. The lack of indicators of commercial activity, leads us to propose the analysis of a pre-commercial stage of technology that we call entrepreneurial intention. After the literature review, we present a database of academic inventors in patents granted to the university, identifying patenting with an entrepreneurial intention, following Lomas (1993) knowledge transfer taxonomy. Data about publications and received citations by academic inventors is also considered for knowledge diffusion; as well as the supervision of end-of-degree projects in undergraduate and graduate studies; before and after the patent was granted, for knowledge dissemination. Using a binomial model, we estimated two data sets, one for the period 1984-2000 and the second for 2001-2020. Our findings reveal, an average increase of 60% in the number of patents obtained. We also found that the characteristics of the research group are significant in both models, but in the 2001-2020 period it is more important to integrate foreign inventors than patenting with firms, the dissemination of knowledge is more significant and has greater importance in the model. To respond to what extent entrepreneurial intention affects the diffusion and dissemination of knowledge, greater attention should be paid to the diffusion of knowledge since in both models the variable that represents publications after patenting is not significant. The explanation about the dissemination of knowledge improves substantially from one period to another.
General neural network approach to compressive feature extraction
Authors: Giljum Anthony , Liu Weidi , Li Le , Weber Reed , Kelly Kevin F.
Published: July 2021

Computer vision with a single-pixel camera is currently limited by a
trade-off between reconstruction capability and image classification
accuracy. If random projections are used to sample the scene, then
reconstruction is possible but classification accuracy suffers,
especially in cases with significant background signal. If data-driven
projections are used, then classification accuracy improves and the
effect of the background is diminished, but image recovery is not
possible. Here, we employ a shallow neural network to nonlinearly
convert from measurements acquired with random patterns to
measurements acquired with data-driven patterns. The results
demonstrate that this improves classification accuracy while still
allowing for full reconstruction.
All-POF coupling ratio-imbalanced Sagnac interferometer as a refractive index sensor
Authors: Santiago-Hernández H. , Bravo-Medina B. , Mora-Nuñez A. , Flores J. L. , García-Torales G. , Pottiez O.
Published: July 2021

A polymer optical Sagnac interferometer is proposed as a compact and
low-cost refractive index sensor for the first time to our best
knowledge. The Sagnac interferometer is fabricated by only one piece
of fiber to facilitate its fabrication and to avoid losses due to
misalignment or fusion. The coupler was developed based on chemical
and twisting techniques of

∼

5

c
m

of fiber. We modified the coupling
ratio by varying the refractive index of media surrounding the coupler
and consequently modified the transmission. For several values of
mass percent concentration of sugar solutions surrounding the coupler,
we found that transmittance decreases as the mass concentration
increases. However, the decay is faster for the low concentration,
while the decay is slower for higher concentrations. Two sets of
experiments were carried out, at high (

≥

1 gm/100 ml) and low (

<

1

g
m

/

100

m
l

) mass concentration of sugar
solutions. The calibration of the sensor was done at 733 nm, where the
response of the interferometer displays larger transmission variations
for different solutions. The refractive index estimation was possible
by correlation of the transmittance function (calculated by fitting
the experimental data) with a linear refractive index model. The
estimated resolution of the system is 0.057 weight percent of sugar
solution, determined by the noise of the system.
Low power, high speed, all-optical logic gates based on optical bistability in graphene-containing compact microdisk resonators
Authors: Keshtkar Peyman , Miri Mehdi , Yasrebi Navid
Published: July 2021

CMOS-compatible all-optical logic gates based on optical bistability are designed and numerically characterized. For this, graphene and H-BN-based hybrid plasmonic microdisk/waveguide structures have been used to achieve optical bistability at very low threshold power and with small dimensions. The simulation results and coupled-mode theory calculations show that, by adjusting the radius of the microdisk resonator, the threshold power and response time of the optical bistability can be tuned in a wide range. It is shown that bistable devices with overall dimensions of

2

µ

m

×

2.2

µ

m

can easily be designed having either threshold powers as low as 0.79 µW (microdisk radius of 0.92 µm) or very short fall time and rise times of 1.24 and 1.53 ps (microdisk radius of 0.93 µm). The design procedure for the AND, NAND, OR, NOR, and NOT logic gates is discussed. Simulation results show that the proposed logic gates have much smaller footprints, lower power consumption, and higher speeds with acceptable response time, compared with the previously reported structures.
Continuous-zoom bifocal metalens by mutual motion of cascaded bilayer metasurfaces in the visible
Authors: Wang Chang , Sun Yan , Zhang Qiangbo , Yu Zeqing , Tao Chenning , Zhang Jinlei , Wu Fei , Wu Rengmao , Zheng Zhenrong
Published: July 2021

Metalens, a subcategory of metasurfaces, has been widely investigated by virtue of its miniature and ultrathin characteristics as well as versatile functionalities. In this study, a tunable bifocal metalens with two continuous-zoom foci is proposed and numerically verified. This design utilizes two cascaded layers of metasurfaces, and different phase profiles for incidences of opposite helicities are imparted on each layer by the combination of geometric phase and propagation phase. When two layers of metasurfaces are actuated laterally, focal lengths of both foci are tuned continuously, with the difference of both focal lengths increasing or decreasing. Additionally, the zoom range for each focus can be designed at will, and the relative intensity of both foci can be modulated by altering the ellipticity of incidence, with the focusing efficiency of the bifocal metalens varying from 19.8% to 32.7% for numerical apertures in a range from 0.53 to 0.78. The proposed device is anticipated to find applications in multi-plane imaging, optical tomography technique, optical data storage, and so on.
Photonic decision-making for arbitrary-number-armed bandit problem utilizing parallel chaos generation
Authors: Peng Jiafa , Jiang Ning , Zhao Anke , Liu Shiqin , Zhang Yiqun , Qiu Kun , Zhang Qianwu
Published: July 2021

In this paper, we propose and experimentally demonstrate a novel scheme that helps to solve an any-number-armed bandit problem by utilizing two parallel simultaneously-generated chaotic signals and the epsilon (ɛ)-greedy strategy. In the proposed scheme, two chaotic signals are experimentally generated, and then processed by an 8-bit analog-to-digital conversion (ADC) with 4 least significant bits (LSBs), to generate two amplitude-distribution-uniform sequences for decision-making. The correspondence between these two random sequences and different arms is established by a mapping rule designed in virtue of the ɛ-greedy-strategy. Based on this, decision-making for an exemplary 5-armed bandit problem is successfully performed, and moreover, the influences of the mapping rule and unknown reward probabilities on the correction decision rate (CDR) performance for the 4-armed to 7-armed bandit problems are investigated. This work provides a novel way for solving the arbitrary-number-armed bandit problem.
Quantitative study of conservative gradient force and non-conservative scattering force exerted on a spherical particle in optical tweezers
Authors: Li Xiao , Zheng Hongxia , Yuen Chi Hong , Du Junjie , Chen Jun , Lin Zhifang , Ng Jack
Published: July 2021

We rigorously calculate the conservative gradient force (GF) and the non-conservative scattering force (SF) associated with the optical tweezers (the single beam optical trap). A wide range of parameters are considered, with particle size ranging from the Rayleigh to Mie regime (radius ∼3 µm), dielectric constant ranging from metallic (large and negative) to high dielectrics (large and positive), numerical aperture (NA) ranging from 0.5 to 1.33, and different polarizations. The trap depth associated with GF can reach 123 and 168 kBT per mW for a 0.5 µm-radius polystyrene particle illuminated by a 1064 nm Gaussian beam with NA = 0.9 and 1.3, respectively. This indicates that unless at a low beam power or with a small NA, the Brownian fluctuations do not play a role in the stability. The transverse GF orthogonal to beam propagation always dominates over the transverse SF. While the longitudinal SF can be larger than the longitudinal GF when the scattering is strong, the NA is small, or when absorption is present, optical trapping under these conditions is difficult. Generally speaking, absorption reduces GF and enhances SF, while increasing a dielectric constant enhances GF slightly but boosts SF significantly owing to stronger scattering. These results verify previous experimental observations and explain why optical tweezers are so robust across such a wide range of conditions. Our quantitative calculations will also provide a guide to future studies.
Three-dimensional stochastic simulation of chemoattractant-mediated excitability in cells
Authors: Biswas Debojyoti , Devreotes Peter N. , Iglesias Pablo A.
Published: July 2021

During the last decade, a consensus has emerged that the stochastic triggering of an excitable system drives pseudopod formation and subsequent migration of amoeboid cells. The presence of chemoattractant stimuli alters the threshold for triggering this activity and can bias the direction of migration. Though noise plays an important role in these behaviors, mathematical models have typically ignored its origin and merely introduced it as an external signal into a series of reaction-diffusion equations. Here we consider a more realistic description based on a reaction-diffusion master equation formalism to implement these networks. In this scheme, noise arises naturally from a stochastic description of the various reaction and diffusion terms. Working on a three-dimensional geometry in which separate compartments are divided into a tetrahedral mesh, we implement a modular description of the system, consisting of G-protein coupled receptor signaling (GPCR), a local excitation-global inhibition mechanism (LEGI), and signal transduction excitable network (STEN). Our models implement detailed biochemical descriptions whenever this information is available, such as in the GPCR and G-protein interactions. In contrast, where the biochemical entities are less certain, such as the LEGI mechanism, we consider various possible schemes and highlight the differences between them. Our simulations show that even when the LEGI mechanism displays perfect adaptation in terms of the mean level of proteins, the variance shows a dose-dependence. This differs between the various models considered, suggesting a possible means for determining experimentally among the various potential networks. Overall, our simulations recreate temporal and spatial patterns observed experimentally in both wild-type and perturbed cells, providing further evidence for the excitable system paradigm. Moreover, because of the overall importance and ubiquity of the modules we consider, including GPCR signaling and adaptation, our results will be of interest beyond the field of directed migration.
On the influence of prior information evaluated by fully Bayesian criteria in a personalized whole-brain model of epilepsy spread
Authors: Hashemi Meysam , Vattikonda Anirudh N. , Sip Viktor , Diaz-Pier Sandra , Peyser Alexander , Wang Huifang , Guye Maxime , Bartolomei Fabrice , Woodman Marmaduke M. , Jirsa Viktor K.
Published: July 2021

Individualized anatomical information has been used as prior knowledge in Bayesian inference paradigms of whole-brain network models. However, the actual sensitivity to such personalized information in priors is still unknown. In this study, we introduce the use of fully Bayesian information criteria and leave-one-out cross-validation technique on the subject-specific information to assess different epileptogenicity hypotheses regarding the location of pathological brain areas based on a priori knowledge from dynamical system properties. The Bayesian Virtual Epileptic Patient (BVEP) model, which relies on the fusion of structural data of individuals, a generative model of epileptiform discharges, and a self-tuning Monte Carlo sampling algorithm, is used to infer the spatial map of epileptogenicity across different brain areas. Our results indicate that measuring the out-of-sample prediction accuracy of the BVEP model with informative priors enables reliable and efficient evaluation of potential hypotheses regarding the degree of epileptogenicity across different brain regions. In contrast, while using uninformative priors, the information criteria are unable to provide strong evidence about the epileptogenicity of brain areas. We also show that the fully Bayesian criteria correctly assess different hypotheses about both structural and functional components of whole-brain models that differ across individuals. The fully Bayesian information-theory based approach used in this study suggests a patient-specific strategy for epileptogenicity hypothesis testing in generative brain network models of epilepsy to improve surgical outcomes.
COVIDomic: A multi-modal cloud-based platform for identification of risk factors associated with COVID-19 severity
Authors: Naumov Vladimir , Putin Evgeny , Pushkov Stefan , Kozlova Ekaterina , Romantsov Konstantin , Kalashnikov Alexander , Galkin Fedor , Tihonova Nina , Shneyderman Anastasia , Galkin Egor , Zinkevich Arsenii , Cope Stephanie M. , Sethuraman Ramanathan , Oprea Tudor I. , Pearson Alexander T. , Tay Savas , Agrawal Nishant , Dubovenko Alexey , Vanhaelen Quentin , Ozerov Ivan , Aliper Alex , Izumchenko Evgeny , Zhavoronkov Alex
Published: July 2021

Coronavirus disease 2019 (COVID-19) is an acute infection of the respiratory tract that emerged in December 2019 in Wuhan, China. It was quickly established that both the symptoms and the disease severity may vary from one case to another and several strains of SARS-CoV-2 have been identified. To gain a better understanding of the wide variety of SARS-CoV-2 strains and their associated symptoms, thousands of SARS-CoV-2 genomes have been sequenced in dozens of countries. In this article, we introduce COVIDomic, a multi-omics online platform designed to facilitate the analysis and interpretation of the large amount of health data collected from patients with COVID-19. The COVIDomic platform provides a comprehensive set of bioinformatic tools for the multi-modal metatranscriptomic data analysis of COVID-19 patients to determine the origin of the coronavirus strain and the expected severity of the disease. An integrative analytical workflow, which includes microbial pathogens community analysis, COVID-19 genetic epidemiology and patient stratification, allows to analyze the presence of the most common microbial organisms, their antibiotic resistance, the severity of the infection and the set of the most probable geographical locations from which the studied strain could have originated. The online platform integrates a user friendly interface which allows easy visualization of the results. We envision this tool will not only have immediate implications for management of the ongoing COVID-19 pandemic, but will also improve our readiness to respond to other infectious outbreaks.
Health seeking behavior after the 2013–16 Ebola epidemic: Lassa fever as a metric of persistent changes in Kenema District, Sierra Leone
Authors: Koch Mikaela R. , Kanneh Lansana , Wise Paul H. , Kurina Lianne M. , Alhasan Foday , Garry Robert F. , Schieffelin John S. , Shaffer Jeffrey G. , Grant Donald S.
Published: July 2021

Background

The West African Ebola epidemic of 2013–2016 killed nearly 4,000 Sierra Leoneans and devastated health infrastructure across West Africa. Changes in health seeking behavior (HSB) during the outbreak resulted in dramatic underreporting and substantial declines in hospital presentations to public health facilities, resulting in an estimated tens of thousands of additional maternal, infant, and adult deaths per year. Sierra Leone’s Kenema District, a major Ebola hotspot, is also endemic for Lassa fever (LF), another often-fatal hemorrhagic disease. Here we assess the impact of the West African Ebola epidemic on health seeking behaviors with respect to presentations to the Kenema Government Hospital (KGH) Lassa Ward, which serves as the primary health care referral center for suspected Lassa fever cases in the Eastern Province of Sierra Leone.

Methodology/Principal findings

Presentation frequencies for suspected Lassa fever presenting to KGH or one of its referral centers from 2011–2019 were analyzed to consider the potential impact of the West African Ebola epidemic on presentation patterns. There was a significant decline in suspected LF cases presenting to KGH following the epidemic, and a lower percentage of subjects were admitted to the KGH Lassa Ward following the epidemic. To assess general HSB, a questionnaire was developed and administered to 200 residents from 8 villages in Kenema District. Among 194 completed interviews, 151 (78%) of respondents stated they felt hospitals were safer post-epidemic with no significant differences noted among subjects according to religious background, age, gender, or education. However, 37 (19%) subjects reported decreased attendance at hospitals since the epidemic, which suggests that trust in the healthcare system has not fully rebounded. Cost was identified as a major deterrent to seeking healthcare.

Conclusions/Significance

Analysis of patient demographic data suggests that fewer individuals sought care for Lassa fever and other febrile illnesses in Kenema District after the West African Ebola epidemic. Re-establishing trust in health care services will require efforts beyond rebuilding infrastructure and require concerted efforts to rebuild the trust of local residents who may be wary of seeking healthcare post epidemic.
Effect of habitat fragmentation on rural house invasion by sylvatic triatomines: A multiple landscape-scale approach
Authors: Cardozo Miriam , Fiad Federico Gastón , Crocco Liliana Beatríz , Gorla David Eladio
Published: July 2021

After the decrease of the relative importance of Triatoma infestans, a number of studies reported the occurrence of sylvatic triatomines dispersing actively to domestic environments in the dry western Chaco Region of Argentina. Anthropic modification of the landscape is mentioned as one of the main causes of the increase in domicile invasion. The aim of this study was to describe the occurrence and frequency of sylvatic triatomines invading rural houses, and to evaluate the effect of habitat fragmentation and other ecological factors on the invasion of rural houses in central Argentina. We hypothesized that the decrease in food sources and the loss of wild ecotopes, as a consequence of habitat fragmentation, increase the chances of invasion by triatomines. The entomological data was collected by community-based vector surveillance during fieldwork carried out between 2017–2020, over 131 houses located in fourteen rural communities in the northwest of Córdoba Province (central Argentina). We used generalized linear models to evaluate the effect of (i) the environmental anthropic disturbance in the study area, (ii) the composition and configuration of the landscape surrounding the house, (iii) the spatial arrangement of houses, (iv) and the availability of artificial refuges and domestic animals in the peridomicile, on house invasion by triatomines. We report the occurrence of seven species of triatomines invading rural houses in the study area -T. infestans, T. guasayana, T. garciabesi, T. platensis, T. delpontei, T. breyeri and P. guentheri-. Study data suggest that invasion by triatomines occurs with higher frequency in disturbed landscapes, with houses spatially isolated and in proximity to subdivided fragments of forest. The availability of domestic refuges in the peridomestic structures as well as the presence of a higher number of domestic animals increase the chances of invasion by triatomines.