bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the FSO communication system using adaptive and MIMO MPPM with pointing errors and an atmospheric turbulence channel
Authors: Malik Suman , Sahu Prasant Kumar
Published: January 2021

The terrestrial free space optical (FSO) communication system is attracting increased attention among the scientific and commercial research community due to its ultra-high data rate capability, licensed free large bandwidth, cost efficiency, fast and easy deployment, and secure wireless data transmission. However, the FSO system is severely affected by atmospheric conditions such as local weather conditions and fading due to turbulence. Moreover, system performance is significantly affected by pointing errors, which are caused by the misalignment between transmitter-receiver sections. Many statistical models have been proposed in the literature in order to address this significant impairment of the FSO system. In this paper, M-ary pulse position modulation (MPPM)-based FSO signal transmission over a Gamma-Gamma (G-G) fading channel is analyzed in the presence of weak to strong atmospheric turbulence and pointing errors. A multiple-input-multiple-output (MIMO) system with an equal gain combining (EGC) diversity scheme is proposed to enhance the performance of the system. The analytical closed-form expressions are obtained in terms of MeijerG-function to approximate the average bit error rate (BER) and outage probability. Furthermore, the adaptive transmission modulation (ATM) scheme is proposed to enhance the bandwidth efficiency of the FSO system link. The analytical results exhibit that the effect of turbulence and misalignment on the performance metrics (BER, outage probability) and the proposed MIMO-FSO communication link with the EGC scheme appreciably improves the system performance, and Monte Carlo simulation confirms the validation of the analytical expressions. It can also observe that bandwidth efficiency significantly improved with the proposed ATM scheme over non-adaptive counterparts.
Method of combining thermal homology theory with a genetic algorithm for the design and optimization of precise submillimeter-wave antennas
Authors: Zhang Mingzhu , Wang Hairen , Zuo Yingxi
Published: January 2021

It is a common problem in precise submillimeter-wave telescopes that thermal deformation coupling between major subsystems results from materials with different coefficients of thermal expansion or at different temperatures. Here, the method of combining thermal homology theory with a genetic algorithm (CTHTGA) is proposed for the design and optimization of large precise submillimeter-wave antennas. The CTHTGA method has two key steps: (1) design of the structure of the antenna according to thermal homology theory; and (2) structural optimization based on the genetic algorithm. It has the ability to solve the problem of thermal deformation coupling well and to ensure sufficient rigidity. As an application, CTHTGA was used in the design and optimization of a 1.2 m submillimeter-wave telescope. The results showed that the CTHTGA method, compared to the previous design of a 1.2 m antenna, not only dramatically decreases the impact of thermal deformation coupling but gives the designed antenna sufficient stiffness and smaller gravity deformation. Moreover, other things being equal, a method of combining thermal homology theory with zero-order and a first-order compound optimization algorithm is used to quantitatively validate the CTHTGA method. As the results suggest, the overall performance of the CTHTGA is, to the best of our knowledge, better than that of the latter method.
Local stress analysis of blunt V-notches using the digital gradient sensing method
Authors: Liu Wei , Li Longkang , Qiao Yaxu
Published: January 2021

In this study, the digital gradient sensing (DGS) method is extended to determine the local stress fields at the blunt V-notch tip. Completely analytical expressions for angular deflections of light beams in the vicinity of the blunt V-notch tip are deduced based on Filippi’s stress equation. Under plane stress conditions, the patterns of angular deflection related to two orthogonal stress gradients are theoretically plotted, and the effects of notch angle and notch radius are synthetically investigated, respectively. New procedures for the evaluation of local stress components and generalized notch stress intensity factor (NSIF) are presented using the experimental patterns of angular deflection contours. The NSIF values at the blunt V-notch tip in polymer materials with different geometric parameters under three-point-bend loading conditions are extracted from the DGS measurements. A good agreement is observed between the experimental data and the finite element simulations, which can verify the effectiveness and accuracy of the proposed DGS method.
Atmospheric correction over the ocean for hyperspectral radiometers using multi-angle polarimetric retrievals
Authors: Hannadige Neranga K. , Zhai Peng-Wang , Gao Meng , Franz Bryan A. , Hu Yongxiang , Knobelspiesse Kirk , Jeremy Werdell P. , Ibrahim Amir , Cairns Brian , Hasekamp Otto P.
Published: January 2021

We developed a fast and accurate polynomial based atmospheric correction (POLYAC) algorithm for hyperspectral radiometric measurements, which parameterizes the atmospheric path radiances using aerosol properties retrieved from co-located multi-wavelength multi-angle polarimeter (MAP) measurements. This algorithm has been applied to co-located spectrometer for planetary exploration (SPEX) airborne and research scanning polarimeter (RSP) measurements, where SPEX airborne was used as a proxy of hyperspectral radiometers, and RSP as the MAP. The hyperspectral remote sensing reflectance obtained from POLYAC is accurate when compared to Aerosol Robotic Network (AERONET), and Visible Infrared Imaging Radiometer Suite (VIIRS) ocean color products. POLYAC provides a robust alternative atmospheric correction algorithm for hyperspectral or multi-spectral radiometric measurements for scenes involving coastal oceans and/or absorbing aerosols, where traditional atmospheric correction algorithms are less reliable.
Stress-induced deformation of the coating on large lightweight freeform optics
Authors: Qiao Guanbo , Hu Haixiang , Zhang Xuejun , Luo Xiao , Xue Donglin , Zhang Ge , Hu Haifei , Yi Liqi , Yang Yu , Deng Weijie
Published: January 2021

Large aperture, lightweight optics are frequently utilized in modern optical systems. However, despite the use of advanced techniques for developing their materials, fabrication, and mechanical structure, the coatings placed on the substrates induce slight lattice mismatches and increase the thin film stress on polished surfaces. This significantly distorts nano-accuracy optical surfaces, especially on lightweight freeform surfaces. In this study, we construct a finite element model (FEM) and a ray tracing model to estimate the impact of the stress-induced deformation of the coating on a 1.5m class lightweight silicon carbine (SiC) mirror with a freeform surface. Our simulation results are within 10% deviation from the experimental results, and the deformation texture map matches these results as well. We discuss several possible strategies to overcome stress-induced deformation, including fabrication pre-compensation, lightweight structure redesign, and an inverse print-through effect.
High-speed quantum cascade detector characterized with a mid-infrared femtosecond oscillator
Authors: Hillbrand Johannes , Matthieu Krüger Léonard , Dal Cin Sandro , Knötig Hedwig , Heidrich Jonas , Maxwell Andrews Aaron , Strasser Gottfried , Keller Ursula , Schwarz Benedikt
Published: January 2021

Quantum cascade detectors (QCD) are photovoltaic mid-infrared detectors based on intersubband transitions. Owing to the sub-picosecond carrier transport between subbands and the absence of a bias voltage, QCDs are ideally suited for high-speed and room temperature operation. Here, we demonstrate the design, fabrication, and characterization of 4.3 µm wavelength QCDs optimized for large electrical bandwidth. The detector signal is extracted via a tapered coplanar waveguide (CPW), which was impedance-matched to 50 Ω. Using femtosecond pulses generated by a mid-infrared optical parametric oscillator (OPO), we show that the impulse response of the fully packaged QCDs has a full-width at half-maximum of only 13.4 ps corresponding to a 3-dB bandwidth of more than 20 GHz. Considerable detection capability beyond the 3-dB bandwidth is reported up to at least 50 GHz, which allows us to measure more than 600 harmonics of the OPO repetition frequency reaching 38 dB signal-to-noise ratio without the need of electronic amplification.
Group-velocity-dispersion engineering of tantala integrated photonics
Authors: Black Jennifer A. , Streater Richelle , Lamee Kieran F. , Carlson David R. , Yu Su-Peng , Papp Scott B.
Published: January 2021

Designing integrated photonics, especially to leverage Kerr-nonlinear optics, requires accurate and precise knowledge of the refractive index across the visible to infrared spectral ranges. Tantala (

T

a

2

O

5

) is an emerging material platform for integrated photonics and nanophotonics that offers broadband ultralow loss, moderately high nonlinearity, and advantages for scalable and heterogeneous integration. We present refractive index measurements on a thin film of tantala, and we explore the efficacy of this data for group-velocity-dispersion (GVD) engineering with waveguide and ring-resonator devices. In particular, the observed spectral extent of supercontinuum generation in fabricated waveguides and the wavelength dependence of free spectral range (FSR) in optical resonators provide a sensitive test of our integrated photonics design process. Our work opens up new design possibilities with tantala, including with octave-spanning soliton microcombs.
Label-free multimodal microscopy using a single light source and detector for biological imaging
Authors: Kang Juehyung , Kang Ungyo , Nam Hyeong Soo , Kim Wooseop , Kim Hyun Jung , Kim Ryeong Hyeon , Kim Jin Won , Yoo Hongki
Published: January 2021

Multimodal nonlinear microscopy has been widely applied in biology and medicine due to its relatively deep penetration into tissue and its label-free manner. However, current multimodal systems require the use of multiple sources and detectors, leading to bulky, complex, and expensive systems. In this Letter, we present a novel method of using a single light source and detector for nonlinear multimodal imaging of biological samples. Using a photonic crystal fiber, a pulse picker, and multimode fibers, our developed system successfully acquired multimodal images of swine coronary arteries, including two-photon excitation fluorescence, second-harmonic generation, coherent anti-Stokes Raman scattering, and backreflection. The developed system could be a valuable tool for various biomedical applications.
Cluster analysis of resistance combinations in Escherichia coli from different human and animal populations in Germany 2014-2017
Authors: Suwono Beneditta , Eckmanns Tim , Kaspar Heike , Merle Roswitha , Zacher Benedikt , Kollas Chris , Weiser Armin A. , Noll Ines , Feig Marcel , Tenhagen Bernd-Alois
Published: January 2021

Recent findings on Antibiotic Resistance (AR) have brought renewed attention to the comparison of data on AR from human and animal sectors. This is however a major challenge since the data is not harmonized. This study performs a comparative analysis of data on resistance combinations in Escherichia coli (E. coli) from different routine surveillance and monitoring systems for human and different animal populations in Germany. Data on E. coli isolates were collected between 2014 and 2017 from human clinical isolates, non-clinical animal isolates from food-producing animals and food, and clinical animal isolates from food-producing and companion animals from national routine surveillance and monitoring for AR in Germany. Sixteen possible resistance combinations to four antibiotics—ampicillin, cefotaxime, ciprofloxacin and gentamicin–for these populations were used for hierarchical clustering (Euclidian and average distance). All analyses were performed with the software R 3.5.1 (Rstudio 1.1.442). Data of 333,496 E. coli isolates and forty-one different human and animal populations were included in the cluster analysis. Three main clusters were detected. Within these three clusters, all human populations (intensive care unit (ICU), general ward and outpatient care) showed similar relative frequencies of the resistance combinations and clustered together. They demonstrated similarities with clinical isolates from different animal populations and most isolates from pigs from both non-clinical and clinical isolates. Isolates from healthy poultry demonstrated similarities in relative frequencies of resistance combinations and clustered together. However, they clustered separately from the human isolates. All isolates from different animal populations with low relative frequencies of resistance combinations clustered together. They also clustered separately from the human populations. Cluster analysis has been able to demonstrate the linkage among human isolates and isolates from various animal populations based on the resistance combinations. Further analyses based on these findings might support a better one-health approach for AR in Germany.
Adverse Childhood Experiences are associated with choice of partner, both partners' relationship and psychosocial health as reported one year after birth of a common child. A cross-sectional study
Authors: Andersson Sven-Olof , Annerbäck Eva-Maria , Söndergaard Hans Peter , Hallqvist Johan , Kristiansson Per
Published: January 2021

Adverse Childhood Experiences (ACEs) are common and known to have consequences for individuals’ adult health, leading to a higher risk of illness. The aims of the study were to investigate the ACEs in couples, to examine the extent of assortative mating and to investigate the association between the relationship of the load of ACEs within couples and health outcomes, one year after the birth of a common child. At antenatal clinics in Sweden 818 couples were recruited and investigated one year after the birth of a common child answering a questionnaire including the exposure to ten ACE categories and several outcome variables. In total, 59% of both mothers and partners reported exposure to at least one of the ten ACE categories. Among the mothers 11% and among the partners 9% reported exposure to ≥4 ACE categories (p = 0.12). There was a correlation between the numbers of ACE categories reported by the mothers and their partners (Spearman’s ρ = 0.18, p<0.001). This association pertained to six of the ten ACE categories. In multiple logistic regression analyses, there were associations between the ACE exposure load and unfavourable outcomes among the mothers, the partners and within the couples. Unfavourable outcomes concerning health were most prominent in couples where both members reported exposures to ≥4 ACE categories (self-rated bad health (OR 13.82; CI 2.75–69.49), anxiety (OR 91.97; CI 13.38–632.07), depression (OR 17.42; CI 2.14–141.78) and perceived stress (OR 11.04; CI 2.79–43.73)). Mothers exposed to ACEs tend to have partners also exposed to ACEs. Exposure to ACEs was associated with bad health and unfavourable life conditions within the couples, especially among couples where both members reported exposure to multiple ACEs. These results should stimulate incentives to find, to support and to treat individuals and couples where both members report multiple ACEs. The consequences for the children should be further studied as well as how these families should be treated in health care and society.
Exercise reduced the formation of new adipocytes in the adipose tissue of mice in vivo
Authors: Allerton Timothy D. , Savoie Jonathan J. , Fitch Mark D. , Hellerstein Marc K. , Stephens Jacqueline M. , White Ursula
Published: January 2021

Exercise has beneficial effects on metabolism and health. Although the skeletal muscle has been a primary focus, exercise also mediates robust adaptations in white adipose tissue. To determine if exercise affects in vivo adipocyte formation, fifty-two, sixteen-week-old C57BL/6J mice were allowed access to unlocked running wheels [Exercise (EX) group; n = 13 males, n = 13 females] or to locked wheels [Sedentary (SED) group; n = 13 males, n = 13 females] for 4-weeks. In vivo adipocyte formation was assessed by the incorporation of deuterium (2H) into the DNA of newly formed adipocytes in the inguinal and gonadal adipose depots. A two-way ANOVA revealed that exercise significantly decreased new adipocyte formation in the adipose tissue of mice in the EX group relative to the SED group (activity effect; P = 0.02). This reduction was observed in male and female mice (activity effect; P = 0.03). Independent analysis of the depots showed a significant reduction in adipocyte formation in the inguinal (P = 0.05) but not in the gonadal (P = 0.18) of the EX group. We report for the first time that exercise significantly reduced in vivo adipocyte formation in the adipose tissue of EX mice using a physiologic metabolic 2H2O-labeling protocol.
Magnitudes of post-abortion family planning utilization and associated factors among women who seek abortion service in Bahir Dar Town health facilities, Northwest Ethiopia, facility-based cross-sectional study
Authors: Muchie Amsalu , Getahun Fentie Ambaw , Bekele Yibeltal Alemu , Samual Tsion , Shibabaw Tebkew
Published: January 2021

Introduction

Globally an estimated 55.9 million abortions occur each year. The majority of abortions occur due to unintended pregnancies, which is a result of the non-use of family planning methods. World health organization recommends all clients to utilize modern contraceptive methods after any abortion procedure. However, post-abortion family planning utilization is still low in Ethiopia including the study area. Therefore, this study was expected to determine the utilization of post-abortion family planning and associated factors in Bahir Dar city health facilities in Northwest Ethiopia.

Method

Institution based cross-sectional study was conducted among 408 women from March 1 to April 30, 2019. Data were collected through face-to-face interview using a structured and pre-tested questionnaire. Systematic random sampling was used to select the study participants. Data were cleaned, coded, and entered into epi data and exported to SPSS for further analysis. Both bivariable and multivariable logistic regression were employed. Those variables that had a p-value of less than 0.2 during the bivariate analysis were retained for the multivariable analysis. P-value and confidence interval were used to measure the level of significance on multi-variable analysis and those variables whose P-value, less than 0.05 was considered as statistically significant.

Results

The finding of this study showed that the magnitude of post-abortion family planning (PAFP) utilization was 61% with 95% CI (55, 65). Secondary education level(AOR, 4.58; 95% CI (1.96, 10.69)), certificate and above education level (AOR, 3.06; 95% CI (1.32, 7.08)), Manual Vacuum Aspiration(MVA) (AOR, 7.05; 95% CI (2.94, 16.90)), both medication and Manual Vacuum Aspiration (AOR, 5.34; 95% CI (2.56, 11.13)) and received Post Abortion Family Planning (PAFP) counseling (AOR, 5.99; 95% CI (3.23, 11.18)) were significantly associated with PAFP utilization.

Conclusion

Post-abortion family planning utilization in Bahir Dar health facilities was low compared with the national figure. Secondary and above educational level, respondents who were managed by Manual Vacuum Aspiration (MVA), both Manual Vacuum Aspiration (MVA) and medication and receiving Post Abortion Family Planning (PAFP) counseling were predictors of post-abortion family planning service utilization.
Determinants of the intensity of uremic pruritus in patients receiving maintenance hemodialysis: A cross-sectional study
Authors: Zhao Jian-Hui , Zhu Qiu-Shuang , Li Yi-Wen , Wang Li-Li
Published: January 2021

Background

Uremic pruritus (UP) is a common and frustrating symptom in patients receiving hemodialysis (HD). The majority of patients have mild to moderate itching of the skin, and a small percentage have severe itching, which seriously affects their quality of life and survival rate. However, little is known about factors that influence the intensity of itching in patients.

Methods

A cross-sectional study on uremic pruritus in male and female patients receiving HD was conducted in September 2019. This study included 148 eligible patients who received HD at the Blood Purification Center of Xinchang County People’s Hospital, Zhejiang Province, China from March 2019 to June 2019. We collected general data consisted of age, sex, body mass index (BMI), place of residence, educational level, diabetes mellitus status and duration of HD; as well as clinical, biochemical indicators, including serum calcium (Ca), serum phosphorus (P), serum albumin (ALB), haemoglobin (Hb), serum intact parathyroid hormone (iPTH), pre-dialysis serum urea nitrogen (BUN), normalized protein catabolic rate (nPCR), urea nitrogen clearance index (KT/V), ferritin (FER) and pre-dialysis serum creatinine (sCR). We also assayed the inflammatory cytokine serum high sensitivity C-reactive protein (hs-CRP). The Five-Dimensional Itching Scale (5DIS) was used to evaluate the degree of skin itching (none, mild, moderate, or severe). We used multiple logistic regression to analyze influencing factors on the degree of skin itching in patients with UP.

Results

Of the 148 patients, 60 had uremic pruritus (incidence rate, 40.54%). These included 22 cases of mild skin itching (14.86%), 30 of moderate skin itching (20.27%), and 8 of severe skin itching (5.41%). Compared with uremia patients without skin pruritus, patients with UP had higher levels of iPTH, Hb, BUN, nPCR, and hs-CRP. The composition ratio showed significant differences between urban and rural patients with different degrees of skin itching (P= 0.017); moreover, the difference of iPTH and hs-CRP levels were statistically significant (P= 0.009 and < 0.001, respectively). Using no itching as a reference, multiple logistic regression analysis showed that as hs-CRP level increased, the patient’s risks of mild skin itching (odds ratio [OR] = 1.740; 95% confidence interval [CI], 1.061–2.854;P= 0.028), moderate skin itching (OR = 2.8838 95% CI, 1.744–4.718;P< 0.001), and severe skin itching (OR = 9.440; 95% CI, 3.547–25.124; P < 0.001) all increased as well. Compared with urban residents, rural residents have a higher risk of moderate itching (OR = 3.869; 95% CI, 1.099–13.622; P = 0.035).

Conclusion

Levels of hs-CRP were associated with the intensity of skin itching in patients with UP. Higher hs-CRP levels were closely related to severe skin itching. The relationship between the intensity of skin itching and the environment in maintenance hemodialysis patients needs further clarification.
Preparation of solid dispersion systems for enhanced dissolution of poorly water soluble diacerein: In-vitro evaluation, optimization and physiologically based pharmacokinetic modeling
Authors: Fouad Shahinaze A. , Malaak Fady A. , El-Nabarawi Mohamed A. , Abu Zeid Khalid , Ghoneim Amira M.
Published: January 2021

Diacerein (DCN), a BCS II compound, suffers from poor aqueous solubility and limited bioavailability. Solid dispersion systems (SD) of DCN were prepared by solvent evaporation, using hydrophilic polymers. In-vitro dissolution studies were performed and dissolution parameters were evaluated. I-Optimal factorial design was employed to study the effect of formulation variables (drug:polymer ratio and polymer type) on the measured responses including; drug content (DC) (%), dissolution efficiency at 15 min (DE (15 min)%) and 60 min (DE (60 min)%) and mean dissolution time (MDT) (min). The optimized SD was selected, prepared and evaluated, allowing 10.83 and 3.42 fold increase in DE (15 min)%, DE (60 min)%, respectively and 6.07 decrease in MDT, compared to plain drug. DSC, XRD analysis and SEM micrographs confirmed complete amorphization of DCN within the optimized SD. Physiologically based pharmacokinetic (PBPK) modeling was employed to predict PK parameters of DCN in middle aged healthy adults and geriatrics. Simcyp® software established in-vivo plasma concentration time curves of the optimized SD, compared to plain DCN. Relative bioavailability of the optimized SD compared to plain drug was 229.52% and 262.02% in healthy adults and geriatrics, respectively. Our study reports the utility of PBPK modeling for formulation development of BCS II APIs, via predicting their oral bio-performance.
Are consumer confidence and asset value expectations positively associated with length of daylight?: An exploration of psychological mediators between length of daylight and seasonal asset price transitions
Authors: Sekizawa Yoichi , Konishi Yoko
Published: January 2021

Many economists claim that asset price transitions, particularly stock price transitions, have a seasonal cycle affected by length of daylight. Although they claim that the seasonal affective disorder (SAD) is a mediator between the length of daylight and asset price transitions, recent studies in psychology have been inconclusive about the existence of SAD, and some economics studies disagree regarding the involvement of SAD in seasonal stock price transitions. The purpose of the present study is to examine if there is any psychological mediator linking length of daylight and seasonal asset price transitions as an alternative or supplement to SAD. As a possible mediator, we examined Japan’s consumer confidence index (CCI) and asset value expectations (AVE), which indicate people’s optimism for future economy and are generated from a monthly household survey by the Japanese government. We analyzed individual longitudinal data from this survey between 2004 and 2018 and estimated four fixed-effects regression models to control for time-invariant unobserved heterogeneity across individual households. The results revealed that, (i) there was a seasonal cycle of CCI and AVE; the trough occurred in December and the peak in early summer; (ii) the length of daylight time was positively associated with CCI and AVE; and (iii) the higher the latitude, the larger the seasonal cycle of CCI and AVE became. These findings suggest that the length of the daylight may affect asset price transitions through the cycle of optimism/pessimism for future economy exemplified by the CCI and AVE.
The intra-articular administration of triamcinolone hexacetonide in the treatment of osteoarthritis. Its effects in a naturally occurring canine osteoarthritis model
Authors: Alves João C. , Santos Ana , Jorge Patrícia , Lavrador Catarina , Carreira L. Miguel
Published: January 2021

Objective

To evaluate the effect of an intra-articular (IA) administration of triamcinolone hexacetonide, compared with saline.

Patients and methods

Forty (N = 40) hip joints were randomly assigned to a treatment group (THG, n = 20, receiving IA triamcinolone hexacetonide) and a control group (CG, n = 20, receiving IA saline). On treatment day (T0), and at 8, 15, 30, 90 and 180 days post-treatment, weight distribution, joint range of motion, thigh girth, digital thermography, radiographic signs, synovial fluid interleukin-1 and C-reactive protein levels were evaluated. Data from four Clinical Metrology Instruments was also gathered. Results were compared Repeated Measures ANOVA, with a Huynh-Feldt correction, Paired Samples T-Test or Wilcoxon Signed Ranks Test. A Kaplan-Meier test was performed to compare both groups, with p<0.05.

Results

Joints were graded as mild (65%), moderate (20%) and severe (15%). Patients of both sexes, with a mean age of 6.5±2.4 years and bodyweight of 26.7±5.2kg, were included. No differences were found between groups at T0. Comparing THG to CG, weight distribution showed significant improvements in THG from 8 (p = 0.05) up to 90 days (p = 0.01). THG showed lower values during thermographic evaluation in the Lt view (p<0.01). Pain and function scores also improved from 30 to 180 days. Increasing body weight, age, and presence of caudolateral curvilinear osteophyte corresponded to worse response to treatment. Results of the Kaplan Meier test showed significant differences between groups, with THG performing better considering several evaluations and scores.

Conclusion

THG recorded significant improvements in weight-bearing and in with the considered CMIs, particularly pain scores. Lower thermographic values were registered in THG up to the last evaluation day. Age, sex, and radiographic findings did significantly influenced response to treatment.
Method comparison studies of telomere length measurement using qPCR approaches: A critical appraisal of the literature
Authors: Lindrose Alyssa R. , McLester-Davis Lauren W. Y. , Tristano Renee I. , Kataria Leila , Gadalla Shahinaz M. , Eisenberg Dan T. A. , Verhulst Simon , Drury Stacy
Published: January 2021

Use of telomere length (TL) as a biomarker for various environmental exposures and diseases has increased in recent years. Various methods have been developed to measure telomere length. Polymerase chain reaction (PCR)-based methods remain wide-spread for population-based studies due to the high-throughput capability. While several studies have evaluated the repeatability and reproducibility of different TL measurement methods, the results have been variable. We conducted a literature review of TL measurement cross-method comparison studies that included a PCR-based method published between January 1, 2002 and May 25, 2020. A total of 25 articles were found that matched the inclusion criteria. Papers were reviewed for quality of methodologic reporting of sample and DNA quality, PCR assay characteristics, sample blinding, and analytic approaches to determine final TL. Overall, methodologic reporting was low as assessed by two different reporting guidelines for qPCR-based TL measurement. There was a wide range in the reported correlation between methods (as assessed by Pearson’s r) and few studies utilized the recommended intra-class correlation coefficient (ICC) for assessment of assay repeatability and methodologic comparisons. The sample size for nearly all studies was less than 100, raising concerns about statistical power. Overall, this review found that the current literature on the relation between TL measurement methods is lacking in validity and scientific rigor. In light of these findings, we present reporting guidelines for PCR-based TL measurement methods and results of analyses of the effect of assay repeatability (ICC) on statistical power of cross-sectional and longitudinal studies. Additional cross-laboratory studies with rigorous methodologic and statistical reporting, adequate sample size, and blinding are essential to accurately determine assay repeatability and replicability as well as the relation between TL measurement methods.
Activation of EphA2-EGFR signaling in oral epithelial cells by Candida albicans virulence factors
Authors: Swidergall Marc , Solis Norma V. , Millet Nicolas , Huang Manning Y. , Lin Jianfeng , Phan Quynh T. , Lazarus Michael D. , Wang Zeping , Yeaman Michael R. , Mitchell Aaron P. , Filler Scott G.
Published: January 2021

During oropharyngeal candidiasis (OPC),Candida albicansinvades and damages oral epithelial cells, which respond by producing proinflammatory mediators that recruit phagocytes to foci of infection. The ephrin type-A receptor 2 (EphA2) detects β-glucan and plays a central role in stimulating epithelial cells to release proinflammatory mediators during OPC. The epidermal growth factor receptor (EGFR) also interacts withC.albicansand is known to be activated by the Als3 adhesin/invasin and the candidalysin pore-forming toxin. Here, we investigated the interactions among EphA2, EGFR, Als3 and candidalysin during OPC. We found that EGFR and EphA2 constitutively associate with each other as part of a heteromeric physical complex and are mutually dependent forC.albicans-induced activation. Als3-mediated endocytosis of aC.albicanshypha leads to the formation of an endocytic vacuole where candidalysin accumulates at high concentration. Thus, Als3 potentiates targeting of candidalysin, and both Als3 and candidalysin are required forC.albicansto cause maximal damage to oral epithelial cells, sustain activation of EphA2 and EGFR, and stimulate pro-inflammatory cytokine and chemokine secretion. In the mouse model of OPC,C.albicans-induced production of CXCL1/KC and CCL20 is dependent on the presence of candidalysin and EGFR, but independent of Als3. The production of IL-1α and IL-17A also requires candidalysin but is independent of Als3 and EGFR. The production of TNFα requires Als1, Als3, and candidalysin. Collectively, these results delineate the complex interplay among host cell receptors EphA2 and EGFR andC.albicansvirulence factors Als1, Als3 and candidalysin during the induction of OPC and the resulting oral inflammatory response.
The network structure of Hungarian business clusters
Authors: Futó Péter
Published: January 2021

This article investigates the attitudes to inter-firm co-operation in Hungary by analysing a special group of business networks: the business clusters. Following an overview of cluster policy, a wide range of selfproclaimed business clusters are identified. A small elite of these business networks evolves into successful, sustainable innovative business clusters. However, in the majority of cases, these consortia of interfirm co-operation are not based on a mutually satisfactory model, and as a consequence, many clusters do not survive in the longer term. The paper uses the concepts and models of social network theory in order to explain, why and under what circumstances inter-firm co-operation in clusters enhances the competitiveness of the network as a whole, or alternatively, under what circumstances the cluster remains dependent on Government subsidies. The empirical basis of the study is a thorough internet research about the Hungarian cluster movement; a questionnaire based expert survey among managers of clusters and member companies and a set of in-depth interviews among managers of self-proclaimed clusters. The last chapter analyises the applicability of social network theory in the analysis of business networks and a model involving the value chain is recommended.
Freshwater Integrated Multitrophic Aquaculture (FIMTA) technology in Lake Victoria
Authors: Outa Nicholas
Published: January 2021

The decline in capture fisheries of the world has necessitated the production of fish under different aquaculture systems to bridge the gap in demand. Aquaculture contributes about 50% of fish consumed worldwide. Today, the total annual fish production in Kenya is estimated at about 150,000 metric tons, against an annual demand of 500,000. With the ever-increasing human population and demand for fish, technologies to improve aquaculture production must be embraced to bridge fish supply gap and to achieve nutritional sufficiency. One of these technologies is cage aquaculture which is the rearing of fish(es) in water bodies like dams, lakes, ponds and reservoirs in floating enclosures that allow free flow and exchange of water between the cage the outer water body. The frames of the cages can be made from bamboo, metal or High-Density Poly Ethylene (HDPE). With the challenges associated with pond aquaculture such as competition for land with other uses and susceptibility to floods, cage aquaculture has gained recognition and is rapidly expanding in Kenya and the world over. In Kenya, for example, the use of cages to produce fish is relatively new and is being practised in Lake Victoria in the five riparian Counties of Migori, Homabay, Kisumu, Siaya and Busia (Anjejo, 2017). These cages have several negative impacts on the lakes environment as highlighted below.
Desigualdad y bienestar en el periodo postdictatorial: Chile 1990-1998
Inequality and well-being in the post-dictatorial period: Chile 1990-1998
Authors: Matus-Lopez Mauricio
Published: January 2021

Durante la época post dictatorial (1990-1998) Chile fue considerado un ejemplo de crecimiento económico, transición democrática y mejoras sociales. Durante estos años el PIB creció un 81%, el PIB per cápita un 60% y la tasa de pobreza cayó del 25,7% al 16,1%. Sin embargo, los índices de desigualdad continuaron siendo de los más elevados de la región, de manera que los efectos de las medidas regresivas implementadas durante la dictadura (1973-1989) se mantuvieron en democracia. En esta línea de investigación se analiza la evolución de la desigualdad en distintos aspectos del bienestar (salud, educación, vivienda, trabajo e ingreso), durante el denominado
periodo de oro de la economía chilena.

During the post-dictatorial era (1990-1998) Chile was considered an example of economic growth, democratic transition and social improvements. During these years GDP grew by 81%, GDP per capita by 60% and the poverty rate fell from 25.7% to 16.1%. However, inequality rates remained among the highest in the region, so the effects of regressive measures implemented during the dictatorship (1973-1989) remained in democracy. This line of research analyses the evolution of inequality in different aspects of well-being (health, education, housing, work and income), during the so-called "golden period of the Chilean economy".
McMAHAN, J. Animals. In: A Companion to Applied Ethics.p. 525–536.United Kingdom: Blackwell Publishing Ltd, 2003.
Authors: Coelho Gustavo Henrique de Freitas
Published: January 2021

A tradução enviada para publicação corresponde a um artigo publicado como capítulo de livro. Nome do livro: A Companion to Applied Ethics. Obra organizada por: R.G. Frey e Christopher Heath Wellman. Capítulo traduzido: Animals. Autor do capítulo: Jeff McMahan. (Capítulo 39, páginas 525 a 536).
Acute Hand Ischemia and Digital Amputation After Transradial Coronary Intervention in a Patient With CREST Syndrome
Authors: Earl Thomas J.
Published: January 2021

The radial artery approach for coronary angiography and intervention is rapidly replacing the femoral artery approach, largely because it reduces bleeding and vascular access site complications. However, complications associated with transradial access warrant attention, notably radial artery occlusion. This report focuses on a case of radial artery occlusion after percutaneous coronary intervention in a 46-year-old woman with CREST (calcinosis, Raynaud phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia) syndrome, which ultimately led to acute hand ischemia necessitating amputation of her middle and index fingers.
Alcohol Ablation of Cardiac Tissues Quantified and Evaluated Using CIELAB Euclidean Distances
Authors: Rook Ashley , John Mathews M. , Post Allison , Razavi Mehdi
Published: January 2021

Ethanol solubilizes cell membranes, making it useful for various ablation applications. We examined the effect of time and alcohol type on the extent of ablation, quantified as Euclidean distances between color coordinates.

We obtained biopsy punch samples (diameter, 6 mm) of left atrial appendage, atrial, ventricular, and septal tissue from porcine hearts and placed them in transwell plates filled with ethanol or methanol for 10, 20, 30, 40, 50, or 60 min. Control samples were taken for each time point. At each time point, samples were collected, cut transversely, and photographed. With use of a custom MATLAB program, all images were analyzed in the CIELAB color space, which is more perceptually uniform than the red-green-blue color space. Euclidean distances were calculated from CIELAB coordinates. The mean and standard error of these distances were analyzed. Two-way analysis of variance was used to test for differences among time points, and 2-tailed t tests, for differences between the alcohol datasets at each time point.

Generally, Euclidean distances differed significantly between all time points, except for those immediately adjacent, and methanol produced larger Euclidean distances than ethanol did. Some tissue showed a plateauing effect, potentially indicating transmurality.

Mean Euclidean distances effectively indexed alcohol ablation in cardiac tissue. Furthermore, we found that methanol ablated tissue more effectively than ethanol did. With ethanol, the extent of ablation for atrial tissue was largest at 60 min. We conclude that to achieve full transmurality in clinical applications, ethanol must remain in contact with atrial tissue for at least one hour.
Open Repair of Acute Type A Intramural Hematoma in 3 Patients
Authors: Frankel William C. , Weldon Scott A. , Green Susan Y. , Amarasekara Hiruni S. , LeMaire Scott A. , Coselli Joseph S.
Published: January 2021

Acute aortic syndrome encompasses classic aortic dissection and less common aortic phenomena, including intramural hematoma (IMH), a hemorrhage within the aortic media that occurs without a discrete intimal tear. We reviewed our experience with treating acute type A IMH to better understand this acute aortic syndrome. A review of our clinical database identified 1,902 proximal aortic repairs that were performed from January 2006 through December 2018; of these, 266 were for acute aortic syndrome, including 3 (1.1%) for acute type A IMH. Operative technique varied considerably. All IMH repairs involved hemiarch or total arch replacement. In all 3 patients, the IMH extended distally into the descending thoracic aorta. There were no operative deaths or major adverse events (stroke, paraplegia, paraparesis, or renal failure necessitating dialysis) that persisted to hospital discharge. Length of hospitalization ranged from 5 to 20 days. All 3 patients were alive at follow-up (range, 2–6 yr) and needed no aortic reintervention after their index or staged repairs. In our experience, repair of acute type A IMH was infrequent and could be either simple or complex. Despite our limited experience with this disease, we found that it can be repaired successfully in urgent and emergency cases. Following treatment guidelines for aortic dissection appears to be a reasonable strategy for treating IMH.
Food-Seeking Behavior Is Mediated by Fos-Expressing Neuronal Ensembles Formed at First Learning in Rats
Authors: Quintana-Feliciano Richard , Gobin Christina , Kane Louisa , Sortman Bo , Rakela Samantha , Genovese Ariana , Tunstall Brendan , Caprioli Daniele , Iñiguez Sergio D. , Warren Brandon L.
Published: January 2021

Neuronal ensembles in the infralimbic cortex (IL) develop after prolonged food self-administration training. However, rats demonstrate evidence of learning the food self-administration response as early as day 1, with responding quickly increasing to asymptotic levels. Since the contribution of individual brain regions to task performance shifts over the course of training, it remains unclear whether IL ensembles are gradually formed and refined over the course of extensive operant training, or whether functionally-relevant ensembles might be recruited and formed as early as the initial acquisition of food self-administration behavior. Here, we aimed to determine the role of IL ensembles at the earliest possible point after demonstrable learning of a response-outcome association. We first allowed rats to lever press for palatable food pellets and stopped training rats once their behavior evidenced the response-outcome association (learners). We compared their food-seeking behavior and neuronal activation (Fos protein expression) to similarly trained rats that did not form this association (non-learners). Learners had greater food-seeking behavior and neuronal activation within the medial prefrontal cortex (mPFC), suggesting that mPFC subregions might encode initial food self-administration memories. To test the functional relevance of mPFC Fos-expressing ensembles to subsequent food seeking, we tested region-wide inactivation of the IL using muscimol+baclofen and neuronal ensemble-specific ablation using the Daun02 inactivation procedure. Both region-wide inactivation and ensemble-specific inactivation of the IL significantly decreased food seeking. These data suggest that IL neuronal ensembles form during initial learning of food self-administration behavior, and furthermore, that these ensembles play a functional role in food seeking.
Striatal Afferent BDNF Is Disrupted by Synucleinopathy and Partially Restored by STN DBS
Authors: Miller Kathryn M. , Patterson Joseph R. , Kochmanski Joseph , Kemp Christopher J. , Stoll Anna C. , Onyekpe Christopher U. , Cole-Strauss Allyson , Steece-Collier Kathy , Howe Jacob W. , Luk Kelvin C. , Sortwell Caryl E.
Published: January 2021

Preclinical studies show a link between subthalamic nucleus (STN) deep brain stimulation (DBS) and neuroprotection of nigrostriatal dopamine (DA) neurons, potentially through brain-derived neurotrophic factor (BDNF) signaling. However, the question of whether DBS of the STN can be disease-modifying in Parkinson's disease (PD) remains unanswered. In particular, the impact of STN DBS on α-synuclein (α-syn) aggregation, inclusion-associated neuroinflammation, and BDNF levels has yet to be examined in the context of synucleinopathy. To address this, we examined the effects of STN DBS on BDNF using the α-syn preformed fibril (PFF) model in male rats. While PFF injection resulted in accumulation of phosphorylated α-syn (pSyn) inclusions in the substantia nigra pars compacta (SNpc) and cortical areas, STN DBS did not impact PFF-induced accumulation of pSyn inclusions in the SNpc. In addition, nigral pSyn inclusions were associated with increased microgliosis and astrogliosis; however, the magnitude of these processes was not altered by STN DBS. Total BDNF protein was not impacted by pSyn inclusions, but the normally positive association of nigrostriatal and corticostriatal BDNF was reversed in rats with PFF-induced nigrostriatal and corticostriatal inclusions. Despite this, rats receiving both STN DBS and PFF injection showed increased BDNF protein in the striatum, which partially restored the normal corticostriatal relationship. Our results suggest that pathologic α-syn inclusions disrupt anterograde BDNF transport within nigrostriatal and corticostriatal circuitry. Further, STN DBS has the potential to exert protective effects by modifying the long-term neurodegenerative consequences of synucleinopathy.

SIGNIFICANCE STATEMENTAn increase in brain-derived neurotrophic factor (BDNF) has been linked to the neuroprotection elicited by subthalamic nucleus (STN) deep brain stimulation (DBS) in neurotoxicant models of Parkinson's disease (PD). However, whether STN DBS can similarly increase BDNF in nigrostriatal and corticostriatal circuitry in the presence of α-synuclein (α-syn) inclusions has not been examined. We examined the impact of STN DBS on rats in which accumulation of α-syn inclusions is induced by injection of α-syn preformed fibrils (PFFs). STN DBS significantly increased striatal BDNF protein in rats seeded with α-syn inclusions and partially restored the normal corticostriatal BDNF relationship. These findings suggest that STN DBS can drive BDNF in the parkinsonian brain and retains the potential for neuroprotection in PD.