bluuebunny/crossref_metadata_2025 huggingface dataset:
Meta-analysis in periprosthetic joint infection: a global bibliometric analysis
Authors: Li Cheng , Ojeda-Thies Christina , Xu Chi , Trampuz Andrej
Published: July 2020

Background

Periprosthetic joint infection (PJI) is the most serious complication of joint replacement surgery. Further comorbidities include bedsore, deep vein thrombosis, reinfection, or even death. An increasing number of researchers are focusing on this challenging complication. The aim of the present study was to estimate global PJI research based on bibliometrics from meta-analysis studies.

Methods

A database search was performed in PubMed, Scopus, and Web of Science. Relevant studies were assessed using the bibliometric analysis.

Results

A total of 117 articles were included. The most relevant literature on PJI was found on Scopus. China made the highest contributions to global research, followed by the USA and the UK. The institution with the most contributions was the University of Bristol. The journal with the highest number of publications was The Journal of Arthroplasty, whereas the Journal of Clinical Medicine had the shortest acceptance time. Furthermore, the top three frequently used databases were Embase, MEDLINE, and Cochrane. The most frequent number of authors in meta-analysis studies was four. Most studies focused on the periprosthetic hip and knee. The alpha-defensin diagnostic test, preventive measures on antibiotics use, and risk factors of intra-articular steroid injections were the most popular topic in recent years.

Conclusion

Based on the results of the present study, we found that there was no single database that covered all relevant articles; the optimal method for bibliometric analysis is a combination of databases. The most popular research topics on PJI focused on alpha-defensin, antibiotic use, risk factors of intra-articular steroid injections, and the location of prosthetic hip and knee infection.
Pilot investigation into osteotome hard surface coating and cutting-edge degradation
Authors: White David E. , Bartley Jim , Whittington Christopher , Garcia Lorenzo M. G. , Chand Kaushik , Turangi Celine
Published: July 2020

Background

Osteotomes are bone cutting tools commonly reused in orthopedic surgical procedures. Despite undergoing rigorous cleaning, visual inspection, and sterilization procedures between every use, the condition of the cutting blade edge is commonly not qualitatively assessed. Subjective feedback from surgeons suggests a large variation in osteotome cutting-edge sharpness is found during use. This study seeks to investigate the retention of osteotome cutting-edge sharpness by comparing the wear resistance of as-supplied, electroless nickel, and titanium nitride coated osteotomes following a series of bone cutting tests.

Methods

Changes in edge sharpness were assessed using visual inspection, depth penetration testing that quantified change in the blade sharpness index, and scanning electron microscopy visual analysis. Visual inspection of each osteotome blade edge was then compared to qualitative blade sharpness index measurement.

Results

After use, no cutting-edge damage or change in blade sharpness was detected by visual examination of all three osteotomes; however, the as-supplied osteotome demonstrated 50% loss of blade sharpness index compared to 30% and 15% reduction for the electroless nickel and titanium nitride coated osteotomes, respectively. This finding was supported by scanning electron microscopy evaluation that found greater mechanical damage had occurred along the cutting edge of the as-supplied osteotome compared to the two coated with wear resistant materials.

Conclusions

The rapid loss of blade sharpness found in the as-supplied osteotome supports the degradation in cutting performance frequently reported by surgeons. The findings from this study demonstrate blade sharpness index better detects cutting-edge wear compared to visual inspection. Results from this pilot study also suggest the coating of osteotomes in hard-wearing biocompatible materials assists in retaining cutting-edge sharpness over multiple uses. Further study using a larger sample size is required to validate these findings.
Contextual factors associated with depression among urban refugee and displaced youth in Kampala, Uganda: findings from a cross-sectional study
Authors: Logie Carmen H. , Okumu Moses , Mwima Simon , Hakiza Robert , Chemutai Doreen , Kyambadde Peter
Published: July 2020

Background

Advancing mental health among refugee and displaced adolescents and youth is critically important, as chronic psychological stress can have lifelong harmful impacts. These groups experience socio-environmental stressors that can harm mental health. Informed by a social contextual framework, this study explored the prevalence of depression among urban refugee and displaced youth in Kampala, Uganda and associations with symbolic (violence), relational (social support), and material (food and community insecurity) contexts.

Methods

We implemented a cross-sectional survey with refugee and displaced adolescent girls and young women and adolescent boys and young men aged 16–24 living in Kampala’s informal settlements. We conducted peer-driven recruitment, whereby peer navigators shared study information with their networks and in turn participants were invited to recruit their peers. We conducted gender disaggregated analyses, including stepwise multiple regression to examine factors associated with depression. We then conducted structural equation modeling (SEM) using weighted least squares estimation to examine direct paths from violence, food insecurity, and community insecurity to depression, and indirect effects through social support.

Results

Among participants (n = 445), young women (n = 333) reported significantly higher depression symptoms than young men (n = 112), including any symptoms (73.9% vs. 49.1%,p < 0.0001), mild to moderate symptoms (60.4% vs. 45.5%,p = 0.008), and severe symptoms (13.5% vs 3.6%,p = 0.002). SEM results among young women indicate that the latent violence factor (lifetime sexual and physical violence) had direct effects on depression and social support, but social support did not mediate the path from violence to depression. The model fit the data well: χ2(3) = 9.82,p = 0.020; RMSEA = 0.08, 90% CI [0.03, 0.14], CFI = 0.96). Among young men, SEM findings indicate that food insecurity had direct effects on social support, and an indirect effect on depression through the mediating role of social support. Fit indices suggest good model fit: χ2(3) = 2.09,p = 0.352; RMSEA = 0.02, 90% CI [0.000, 0.19], CFI = 0.99.

Conclusions

Findings reveal widespread depression among urban refugee and displaced youth in Kampala, disproportionately impacting young women. Contextual factors, including food insecurity and violence, increase depression risks. Strategies that reduce gender-based violence and food insecurity, and increase social support networks, have the potential to promote mental health among urban refugee and displaced youth.
Comparative transcriptomic analysis identifies distinct molecular signatures and regulatory networks of chondroclasts and osteoclasts
Authors: Khan Nazir M. , Clifton Kari B. , Lorenzo Joseph , Hansen Marc F. , Drissi Hicham
Published: July 2020

Background

Chondroclasts and osteoclasts have been previously identified as the cells capable of resorbing mineralized cartilage and bone matrices, respectively. While both cell types appear morphologically similar, contain comparable ultrastructural features, and express tartrate-resistant acid phosphatase (TRAP), however, no information is available about the genomic similarities and differences between osteoclasts and chondroclasts.

Methods

To address this question, we laser captured homogeneous populations of TRAP-positive cells that interact with bone (osteoclasts) and TRAP-positive cells that interact with mineralized cartilage (chondroclasts) on the same plane from murine femoral fracture callus sections. We then performed a global transcriptome profiling of chondroclasts and osteoclasts by utilizing a mouse genome Agilent GE 4X44K V2 microarray platform. Multiple computational approaches and interaction networks were used to analyze the transcriptomic landscape of osteoclasts and chondroclasts.

Results

Our systematic and comprehensive analyses using hierarchical clustering and principal component analysis (PCA) demonstrate that chondroclasts and osteoclasts are transcriptionally distinct cell populations and exhibit discrete transcriptomic signatures as revealed by multivariate analysis involving scatter plot, volcano plot, and heatmap analysis. TaqMan qPCR was used to validate the microarray results. Intriguingly, the functional enrichment and integrated network analyses revealed distinct Gene Ontology terms and molecular pathways specific to chondroclasts and osteoclasts and further suggest that subsets of metabolic genes were specific to chondroclasts. Protein-protein interaction (PPI) network analysis showed an abundance of structured networks of metabolic pathways, ATP synthesis, and proteasome pathways in chondroclasts. The regulatory network analysis using transcription factor-target gene network predicted a pool of genes including ETV6, SIRT1, and ATF1 as chondroclast-specific gene signature.

Conclusions

Our study provides an important genetic resource for further exploration of chondroclast function in vivo. To our knowledge, this is the first demonstration of genetic landscape of osteoclasts from chondroclasts identifying unique molecular signatures, functional clustering, and interaction network.
Performances of disseminated intravascular coagulation scoring systems in septic shock patients
Authors: Helms Julie , Severac François , Merdji Hamid , Clere-Jehl Raphaël , François Bruno , Mercier Emmanuelle , Quenot Jean-Pierre , Meziani Ferhat ,   for the CRICS TRIGGERSEP Group (Clinical Research in Intensive Care and Sepsis Trial Group for Global Evaluation and Research in Sepsis)
Published: July 2020

Background

There is no gold standard to diagnose septic shock-induced disseminated intravascular coagulation (DIC). The objective of our multicenter prospective study was to assess the performances of the different major scoring systems in terms of mortality prediction and DIC diagnosis. The JAAM-DIC 2016 score, the ISTH overt-DIC 2001 score, the associations of sepsis-induced coagulopathy (SIC) score with JAAM-DIC 2016 or ISTH overt-DIC scores were tested in patients within 12 h of their admission in ICU for septic shock (day 1) and at day 2.

Results

582 patients were enrolled in the study. 182/567 (32.1%) were diagnosed with DIC according to ISTH overt-DIC score, and 193/561 (34.4%) according to JAAM-DIC score; 486/577 patients (84.2%) were diagnosed with a coagulopathy according to SIC score. A moderate concordance was observed between ISTH overt-DIC and JAAM-DIC [κ = 0.67 (0.60, 0.73),p < 0.001]. The delay of positivity of the scores for early DIC patients was not different between JAAM-DIC and ISTH overt-DIC scores. Although it was positive earlier, SIC score had worse diagnosis specificity, as 84.2% of the patients with septic shock were diagnosed with “coagulopathy”. The specificity of SIC score alone to predict mortality was very low [0.18 (0.15; 0.22)], compared to the ones of JAAM-DIC score [0.71 (0.67; 0.75)], and of ISTH overt-DIC score [0.76 (0.72; 0.80)],p < 0.001. The sensitivity of SIC score to predict mortality was 0.95 [0.89; 0.98], and the ones of JAAM-DIC score and ISTH overt-DIC score were 0.61 [0.50; 0.70] and 0.68 [0.58; 0.77], respectively. There was no benefit in sensitivity and specificity in combining SIC score to JAAM-DIC score or to ISTH overt-DIC score, compared to JAAM-DIC score or ISTH overt-DIC score alone.

Conclusions

Our data suggest that the added value of SIC score alone or combined with other scores is limited, and that both JAAM-DIC score and ISTH overt-DIC score can be used in septic shock patients.

Trial registrationclinicaltrial; Trial registration number: NCT02391792; Date of registration: 18/03/2015; URL of trial registry record:https://clinicaltrials.gov/ct2/show/NCT02391792?term=meziani&draw=4&rank=1
Stochastic modeling of a mosquito-borne disease
Authors: Witbooi Peter J. , Abiodun Gbenga J. , van Schalkwyk Garth J. , Ahmed Ibrahim H. I.
Published: July 2020

We present and analyze a stochastic differential equation (SDE) model for the population dynamics of a mosquito-borne infectious disease. We prove the solutions to be almost surely positive and global. We introduce a numerical invariant ${\mathcal{R}}$
R
of the model with ${\mathcal{R}}<1$
R
<
1
being a condition guaranteeing the almost sure stability of the disease-free equilibrium. We show that stochastic perturbations enhance the stability of the disease-free equilibrium of the underlying deterministic model. We illustrate the main stability theorem through simulations and show how to obtain interval estimates when making forward projections. We consulted a wide range of literature to find relevant numerical parameter values.
Evidence of STEM enactment effectiveness in Asian student learning outcomes
Authors: Wahono Bevo , Lin Pei-Ling , Chang Chun-Yen
Published: July 2020

This study used a systematic review and meta-analysis as a method to investigate whether STEM enactment in Asia effectively enhances students’ learning outcomes. Verifiable examples of science, technology, engineering, and mathematics (STEM) education, effectively being applied in Asia, are presented in this study. The study involved 4768 students from 54 studies. Learning outcomes focused on the students’ academic learning achievement, higher-order thinking skills (HOTS), and motivation. The analysis results of effect sizes showed that the STEM enactments in Asia were effective at a moderate level (0.69 [0.58, 0.81 of 95% CI]) of improving students’ learning outcomes. Sequentially, the effectiveness of STEM enactment starts from students’ higher-order thinking skills, moves to students’ academic learning achievement, and ends with the motivation. In addition, STEM enactments in Asia were carried out with several variations where STEM integrated with project-based learning was preferred. The recommendations of this study include a combination of the learning approach, learning orientation, and duration of instruction, all of which contribute to the STEM enactment effectiveness and maximize results in STEM education. Some practical implications, such as the central role of the teacher during the STEM enactment, are extensively discussed. This study supports that STEM education is a universally crucial tool which effectively prepares students from various national and cultural backgrounds, across Asia, toward improved learning outcomes.
Experience and technique of simultaneous robotic resection for synchronous advanced gastric and rectal cancers: a case report
Authors: Kaida Sachiko , Miyake Toru , Shimizu Tomoharu , Takebayashi Katsushi , Yamaguchi Tsuyoshi , Ishikawa Ken , Tani Masaji
Published: July 2020

Background

Recently, robotic surgery has become more common as a minimally invasive treatment for gastric cancer (GC) and rectal cancer (RC). Herein, we report successful simultaneous robotic gastrectomy and low anterior resection in a patient with advanced GC and RC.

Case presentation

A 76-year-old woman who presented with bloody stool was found to have advanced GC with lymph node metastases and advanced RC. Simultaneous robotic distal gastrectomy with D2 lymph node dissection and Billroth I reconstruction and low anterior resection with D3 lymph node dissection were performed. Preoperatively, multidisciplinary medical staff discussed the case in detail and conducted a simulation with the robot, operating room, and patient. The total operative time was 648 min (console time, 520 min), and the estimated blood loss was small. The patient was discharged on postoperative day 10 without any adverse events. In this case, careful simulation of the patient cart setting and planning of the best port layout resulted in a successful surgical outcome despite this being our first simultaneous total robotic surgery for advanced GC and RC.

Conclusions

Simultaneous robotic surgery for advanced GC and RC may be technically feasible and could provide an option for future minimally invasive treatment.
Effect of high-intensity statin preloading on TIMI flow in patients presenting with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention
Authors: Elserafy Ahmed Shawky , Farag Nabil Mahmoud , El Desoky Ahmed Ibrahim , Eletriby Khaled Adel
Published: July 2020

Background

Acute ST-elevation myocardial infarction (STEMI) is a major cause of morbidity and mortality worldwide. Primary percutaneous coronary intervention (PCI) has improved the outcomes from STEMI and improved myocardial perfusion. However, there is still room for medical therapy to help perfuse the myocardium. The aim of this study was to assess the impact of high-intensity statins used prior to primary PCI in patients presenting with acute STEMI on myocardial perfusion. The study included 170 patients who presented with acute STEMI to Ain Shams University Hospitals and underwent primary percutaneous coronary intervention (PCI). They were divided into two groups where the first group received high-intensity statins (80 mg of atorvastatin or 20 mg of rosuvastatin) besides guideline-recommended therapy before primary PCI and the second group served as a control group and received guideline-recommended therapy, and high-intensity statins were given as usual after going back to the coronary care unit after primary PCI. Post-interventional thrombolysis in myocardial infarction (TIMI) flow grade and myocardial blush grade (MBG) were recorded, and ST-segment resolution was measured.

Results

The LAD was the culprit vessel for the majority of patients in both groups. In the control group, there were 4 patients with TIMI I flow and MBG I, 13 with TIMI II flow and MBG II, and 68 with TIMI III flow and MBG III. Meanwhile, in the cases group, there was 1 patient with TIMI I flow and MBG I, 3 with TIMI II flow and MBG II, and 81 with TIMI III flow and MBG III. This difference was statistically significant with a P value of 0.010. There were 34 patients in the cases group who showed complete ST-segment resolution (40%) vs. 19 patients (22.4%) in the control group which was statistically significant with a P value of 0.013. In addition, ejection fraction had values of mean ± SD of 45.91 ± 5.49 in the cases group vs. 43.01 ± 8.80 in the control group which was statistically significant with a P value of 0.011.

Conclusion

High-intensity statin loading before primary PCI resulted in improved post-procedural TIMI flow, MBG, complete ST-segment resolution, and ejection fraction.
Generation and characterization of an IL2RG knockout Syrian hamster model for XSCID and HAdV-C6 infection in immunocompromised patients
Authors: Li Rong , Ying Baoling , Liu Yanan , Spencer Jacqueline F. , Miao Jinxin , Tollefson Ann E. , Brien James D. , Wang Yaohe , Wold William S. M. , Wang Zhongde , Toth Karoly
Published: July 2020

Model animals are indispensable for the study of human diseases, and in general, of complex biological processes. The Syrian hamster is an important model animal for infectious diseases, behavioral, and metabolic science for which more experimental tools are becoming available. Here, we describe the generation and characterization of an interleukin-2 receptor subunit gamma (IL2RG) knockout (KO) Syrian hamster strain. In humans, mutations in IL2RG can result in a total failure in T and natural killer (NK) lymphocyte development and nonfunctional B lymphocytes (X-linked severe combined immunodeficiency; XSCID). Therefore, we sought to develop a non-murine model to study XSCID and the infectious diseases associated with IL2RG deficiency. We demonstrated that the IL2RG KO hamsters have a lymphoid compartment that is greatly reduced in size and diversity and is impaired in function. As a result of the defective adaptive immune response, IL2RG KO hamsters developed a more severe human adenovirus infection and cleared virus less efficiently than immune competent wild-type (wt) hamsters. Due to this enhanced virus replication, IL2RG KO hamsters developed more severe adenovirus-induced liver pathology than wt hamsters. This novel hamster strain will provide researchers with a new tool to investigate human XSCID and its related infections.
Visual Listening In: Extracting Brand Image Portrayed on Social Media
Authors: Liu Liu , Dzyabura Daria , Mizik Natalie
Published: July 2020

A new approach for measuring consumer brand perceptions from consumer-created brand imagery via deep learning.
Gendered Perspective on Road Crossing Behaviours: A Study of University of Cape Coast Students
Authors: Adjakloe Yvonne D. A , Boateng Ebenezer N. K. , Agyapong Frances , Osei Sampson Aboagye , Koranteng Clifford , Baidoo Abigail N.A , Amoako-Sekyi Regina
Published: July 2020

Globally, studies have provided significant facts about pedestrian demographic characteristics influencing road crossing behaviour of pedestrians. However, there seems to be an unconcluded argument about the influence of demographic characteristics on road crossing behaviour. This study aimed at examine the gender differences in road crossing behaviour of UCC students on campus. The study was done by mapping out the road conditions of pedestrian crossing sites, identifing the perceived gender prone to indulge in bad road crossing behaviour and examine the gendered perception towards drivers’ attitude on road crossing behaviour on campus. An observation checklist was used to observe the road crossing behaviour of both men and women while one Focused Group Discusions was conducted each for men and women groups on UCC campus. Results indicated that men were more prone to road crossing accidents than women. Further analysis showed differing drivers attitudes towards pedestrians and road crossing behaviours by men and women on campus. It was found that women were relatively treated better than men. It is recommended that all road users must be educated to be sensitive to all road users to reduce gender biass attitude and behaviours while using the road.
An introduction to NSAIDs for cattle: recommendations for the veterinary surgeon
Authors: Laven Richard
Published: July 2020

non-steroidal anti-inflammatory drugs (NSAIDs) are increasingly used on cattle in the UK. However there is a lack of evidence on which product to use and when to use it. This guide combines published data on the NSAIDs available for cattle in the UK and basic pharmacology, so that veterinarians can make an informed choice when they prescribe NSAIDs for use in cattle.
Before the killing: intimate partner homicides in a process perspective, Part I
Authors: Enander Viveka , Krantz Gunilla , Lysell Henrik , Örmon Karin
Published: July 2020

This article puts intimate partner homicide (IPH) into a process perspective, and describes the situational precursors that constitute the build-up, that is, the first stage of the IPH process that precedes the deed. Fifty court files, from cases involving 40 male and ten female perpetrators, underwent thematic analysis. Our findings indicate that the build-up phase of an IPH is complex and encompasses several different features, of which some are clearly gendered. The results point to an escalation during the build-up: of possessiveness and violent behaviour in male-to-female cases, of alcohol/drug abuse, of mental health problems and/or of fears for the future, often connected to separation. Concurrent with previous research we found that women often kill in the context of their own victimisation. There were, however, other situations and motives that also stood out as being pertinent.

The practical implications of these findings are that practitioners should be particularly attentive to escalation of known risk factors, especially male possessiveness, and be aware that (the victim wanting) a separation may initiate escalation with lethal consequences.
Single-shot multispectral birefringence mapping by supercontinuum vector beams
Authors: Shoji Misaki , Wakayama Toshitaka , Ishida Hirokazu , Kowa Hiroyuki , Sakaue Kazuyuki , Miura Taisuke , Higashiguchi Takeshi
Published: July 2020

We demonstrated a single-shot, multispectral birefringence mapping by use of a supercontinuum (SC) vector beam. The vector beam, which was generated by a pair of axially symmetric wave plates, leads to angular-variant polarization modulation to divide birefringence properties of a sample substrate into Fourier space. This strategy allows multispectral birefringence mapping from a single-shot image captured by a multispectral imaging detector. For SC vector beam analysis, we also compensated the retardance error of the axially symmetric wave plate in the superbroadband spectrum. Resolutions of retardance and azimuthal angle were 0.4° and 0.2°, respectively, and the spatial resolution was 60 µm. Those results are expected to provide us a single-shot, multispectral birefringence mapping with high spatial resolution as compared with using a scanning laser microscope. Our proposal has extendibility to develop high-speed, high-resolution birefringence imaging spectroscopy.
Measuring the nonlinear optical properties of indium tin oxide thin film using femtosecond laser pulses
Authors: Ali Mona , Shehata Abdullah , Ashour Mohamed , Tawfik Wael Z. , Schuch Reinhold , Mohamed Tarek
Published: July 2020

We have investigated the nonlinear optical properties of indium tin oxide (ITO) thin film coated on soda–lime glass substrate using the z-scan technique. With 100 fs laser pulses, the nonlinear absorption coefficient and nonlinear refractive index are measured at different excitation wavelengths and at different incident intensities. The nonlinear optical absorption shows a competition between saturable absorption and reverse saturable absorption at the different excitation wavelengths and incident intensities. A transition from saturable to reverse saturable absorption was observed with increasing excitation wavelengths. The measured nonlinear refractive index was found to be dependent on wavelength with a maximum value of

5.34

×

10

−
12

c
m

2

/

W

at wavelength of 900 nm.
Automated fast computational adaptive optics for optical coherence tomography based on a stochastic parallel gradient descent algorithm
Authors: Zhu Dan , Wang Ruoyan , Žurauskas Mantas , Pande Paritosh , Bi Jinci , Yuan Qun , Wang Lingjie , Gao Zhishan , Boppart Stephen A.
Published: July 2020

The transverse resolution of optical coherence tomography is decreased by aberrations introduced from optical components and the tested samples. In this paper, an automated fast computational aberration correction method based on a stochastic parallel gradient descent (SPGD) algorithm is proposed for aberration-corrected imaging without adopting extra adaptive optics hardware components. A virtual phase filter constructed through combination of Zernike polynomials is adopted to eliminate the wavefront aberration, and their coefficients are stochastically estimated in parallel through the optimization of the image metrics. The feasibility of the proposed method is validated by a simulated resolution target image, in which the introduced aberration wavefront is estimated accurately and with fast convergence. The computation time for the aberration correction of a 512 × 512 pixel image from 7 terms to 12 terms requires little change, from 2.13 s to 2.35 s. The proposed method is then applied for samples with different scattering properties including a particle-based phantom, ex-vivo rabbit adipose tissue, and in-vivo human retina photoreceptors, respectively. Results indicate that diffraction-limited optical performance is recovered, and the maximum intensity increased nearly 3-fold for out-of-focus plane in particle-based tissue phantom. The SPGD algorithm shows great potential for aberration correction and improved run-time performance compared to our previous Resilient backpropagation (Rprop) algorithm when correcting for complex wavefront distortions. The fast computational aberration correction suggests that after further optimization our method can be integrated for future applications in real-time clinical imaging.
Photon transport model for dense polydisperse colloidal suspensions using the radiative transfer equation combined with the dependent scattering theory
Authors: Fujii Hiroyuki , Tsang Leung , Zhu Jiyue , Nomura Koki , Kobayashi Kazumichi , Watanabe Masao
Published: July 2020

In near-infrared imaging and spectroscopy, high-fidelity modeling of photon transport for dense polydisperse colloidal suspensions is crucial. We developed photon transport models using the radiative transfer equation (RTE) with the dependent scattering theory (DST) at volume fractions up to 20%. The polydispersity and interference effects strongly influence results of the scattering properties and the RTE in cases of small mean diameter and large variance of the particle size distribution. We compared the RTE-results for the Henyey-Greenstein (conventional) function with those for the phase function using the DST. The RTE-results differ between both functions at low volume fractions for forward scattering media, suggesting the limitation of the conventional function.
Multiple angle digital holography for the shape measurement of the unpainted tympanic membrane
Authors: Psota Pavel , Tang Haimi , Pooladvand Koohyar , Furlong Cosme , Rosowski John J. , Cheng Jeffrey T. , Lédl Vít
Published: July 2020

The shape of the tympanic membrane (TM) plays an important role in sound transmission through the ear for hearing. Previously we developed a high-speed holographic system employing a tunable wavelength laser for rapid TM shape measurement. However, the tunable laser illumination was not sufficient to measure the shape of the unpainted TM due to the semi-transparency of the TM and short exposure time of the camera. This paper presents a new multiple angle illumination technique that allows us to use a higher power single wavelength laser to perform shape measurements on the unpainted TM. Accuracy of the new method is demonstrated by a measure of a step gauge provided by the National Institute of Standards and Technology. We successfully applied the new shape measurement method on a fresh postmortem human TM without any paint.
Varifocal augmented reality adopting electrically tunable uniaxial plane-parallel plates
Authors: Wang Yu-Jen , Lin Yi-Hsin , Cakmakci Ozan , Reshetnyak Victor
Published: July 2020

Vergence-accommodation conflict (VAC) is a major challenge in optical-see through augmented reality (AR) system. To resolve this conflict, many approaches are proposed, for instance, by means of adjustment of the projected virtual image to coincide with the surroundings, called image registration, which is more often referred to as varifocal function. In this paper, a varifocal AR system is demonstrated by adopting electrically tunable liquid crystal (LC) plane-parallel plates to solve VAC problem. The LC plates provide electrically tunable optical paths when the directors of LC molecules are re-orientated with applied voltages, which leads to a corresponding change of light speed for an extraordinary wave. To provide a sufficient tunable optical path, three pieces of multiple-layered LC structures are used with the total thickness of the active LC layers (∼510 μm). In experiments, the projected virtual image can be adjusted from 1.4 m to 2.1 m away from the AR system, while the thickness of LC plane-parallel plates are only less than 3 mm without any mechanical moving part. When light propagates in the uniaxial LC layers, the wave vector and the Poynting vector are different. The longitudinal displacement of the image plane is determined by Poynting vectors rather than wave vectors. As a result, the analysis of the AR system should be based on Poynting vectors during geometrical optical analysis. Surprisingly, the tunable range of the longitudinal displacement of Poynting vectors is 2-fold larger than the tunable range of the wave vectors. Moreover, the virtual image shifts in opposite directions with respect to the Poynting vectors and wave vectors. The proposed AR system is not only simple but also thin, and it exhibits a large clear aperture. The investigation here paves the way to a simple solution of the VAC problem for augmented reality systems.
Propagation of the first order annular Bessel Gaussian beams in a uniaxial crystal along the optical axis governed by the Pockels effect
Authors: Wu Xiaolin , Peng Yuanqiang , Qiu Huixin , Chen Kaihui , Wu You , Deng Dongmei , Yang Xiangbo
Published: July 2020

We investigate the first order annular Bessel Gaussian beams propagating in a strontium barium niobate (SBN) crystal governed by the Pockels effect. The left-hand circularly polarized incident waves propagating along the optical axis in the crystal give rise to the right-hand circularly polarized vortex fields with a topological charge of 2. If an external dc field is applied along the optical axis of the SBN crystal, the anisotropy strength can be controlled rapidly, and the rotational invariance around the optical axis is still maintained. In this case, the normalized intensity in the focal region, the power exchange between left-hand and right-hand components, and the exchange between the spin and orbit contributions of the angular momentum flux can be manipulated. We also consider the case where the incident waves are linearly polarized along the x axis. The cylindrical symmetry of two Cartesian components is broken during propagation due to the anisotropy, and the intensity distribution as well as the polarization state of the beams can be regulated electrically.
Measuring the spatial deformation of a liquid-crystal on silicon display with a self-interference effect
Authors: Marco David , Vargas Asticio , Sánchez-López María del Mar , Moreno Ignacio
Published: July 2020

We present a simple technique to characterize the spatial non-uniformity of a liquid-crystal on silicon (LCOS) spatial light modulator (SLM). It is based on illuminating the display with a wavelength out of the operation range, so there is a significant reflection at the output surface. As a consequence, a Gires–Tournois interferometer is directly created, without any alignment requirement and insensitive to vibrations. The beam reflected at the output surface is the reference beam, while the beam reflected at the silicon backplane is modulated with the addressed gray level in order to quantitatively derive its deformation. We provide an experimental demonstration using a LCOS-SLM designed to operate in the near-infrared range but illuminated with visible light.
Laser ellipticity-dependent supercontinuum generation by femtosecond laser filamentation in air
Authors: Chen Na , Wang Tie-Jun , Zhu Zhongbin , Guo Hao , Liu Yaoxiang , Yin Fukang , Sun Haiyi , Leng Yuxin , Li Ruxin
Published: July 2020

We experimentally investigate the laser polarization effect on the supercontinuum (SC) generation through femtosecond laser filamentation in air. By tuning filamenting laser ellipticity from linear polarization to circular polarization, the spectral intensity of the SC after filamentation gradually increases, while the spectral bandwidth of the SC continuously decreases. The laser ellipticity-dependent spectral intensity modulation of the SC is stronger at higher filamenting pulse energy. Laser energy deposits more in linearly polarized laser filaments than in circularly polarized laser filaments. The experimental results are supported by numerical simulations. A physical picture based on the laser ellipticity-dependent clamped intensity inside the filament, together with the Kerr nonlinearity and plasma related self-phase modulations, is proposed to explain the observation.
Provincializing Spotify: Radio, algorithms and conviviality
Authors: Razlogova Elena
Published: July 2020

Focusing on early experiments with algorithms and music streaming at WFMU, the longest-running US freeform radio station, and the Free Music Archive (FMA), a curated open music website, this article shows how commercial streaming services have been indebted to independent, open music infrastructures but have then erased and denied that history. The article ‘provincializes’ music streaming platforms such as Spotify by focusing not on their commercial aims but instead on the ‘convivial’, collaborative practices and spaces that their software engineers and users inhabited. I analyse an experimental national telephone broadcasting service at WFMU in 1989, an algorithmic WFMU radio stream ‘The Flaming Robot of Love’ during the Republican National Convention in 2004 and the ‘Free Music Archive Radio App’ that recommended tracks on the FMA website from 2011 to 2016. The app worked with an application programming interface (API) from Echo Nest. Echo Nests’ algorithmic recommendation engine also powers most commercial streaming services today. When Spotify purchased Echo Nest in 2014 and took the start-up’s open API offline in 2016, it engaged in ‘primitive accumulation’ of open-access knowledge and resources for commercial purposes. The FMA closed in 2019 and now only exists as a static site. As social institutions, however, WFMU and FMA ‘recomposed’ – adapted to a new medium and a new political context – collaborative engineering practices of the early broadcasting era. The article argues that moments of oppositional ‘conviviality’ in media culture such as the FMA should be analysed as elements of a continuous struggle.
Indigenizing radio in Ghana
Authors: Akrofi-Quarcoo Sarah , Gadzekpo Audrey
Published: July 2020

Radio is hailed as Africa’s medium of choice in the global communication age. Introduced as a colonial tool of information, education and entertainment in the early 1930s, radio broadcasting was mainly in colonial languages as colonial administrators perceived local language broadcasting a threat to their empire building and ‘civilization’ agendas. The fortunes of local language broadcasting did not dramatically change in the independence era when broadcast media were in the firm control of the state. From the beginning of the twenty-first century, however, mostly resulting from a more liberalized media environment, local language broadcasting has undergone unprecedented growth. Drawing on written archival material, including internal communication among policy-makers, audience letters, key informant interviews and findings from a recent audience study, this article charts the progressive development of local language radio broadcasting in Ghana, and engages with the role played by early audiences and broadcasters in indigenizing broadcast content.
Producing diversity in BBC radio
Authors: Aujla-Sidhu Gurvinder
Published: July 2020

The voices of minority ethnic staff working in radio are very rarely heard. In fact, the UK radio industry has been singled out, by the government approved regulatory body, as continuing to fail to reflect the diversity of British communities – both on-air and in terms of employment. This article illustrates the perspectives of minority ethnic workers employed at the BBC on the Asian Network, a specialist ethnic radio station, and examines how they craft programme and news content for a distinctive audience. Through in-depth interviews with 30 BBC employees, there is look at the challenges, conflict and barriers this group of staff face. The interviews expose a difference of opinion among staff over the core target audience and the version of Asian identity articulated on-air and demonstrate that a rigid gatekeeping system restricts the dissemination of news content about all the communities that comprise the group British Asian.
Relações entre Estado e associações: origens de associações ambientais em Santos (SP)
Authors: Perez Olivia Cristina
Published: July 2020

A pesquisa verificou a relação entre associações ambientais e Estado, especificamente os motivos envolvidos na criação de associações, segundo os sujeitos envolvidos nesse processo. Partiu-se da corrente teórica chamada de democracia associativa, que considera as associações como artefatos, na medida em que são produtos de estruturas econômicas e políticas. Foram levantados dados sobre o perfil e o financiamento das fundações privadas e associações sem fins lucrativos no Brasil. Também foram feitas entrevistas com membros das onze associações que trabalham em prol do meio ambiente no município de Santos, litoral do estado de São Paulo. Os resultados demonstram que o Estado tem papel central no surgimento das associações ao financiar o trabalho das mesmas.
A História Ambiental da APA Floresta Manaós: um movimento pela defesa territorial e a emersão da Ciência Ambiental
Authors: Oliveira Fabiane Araujo , Santos Elizabeth Conceição
Published: July 2020

A Região Amazônica teve e tem marcada em todo seu processo histórico uma pluralidade de anseios de diversas fontes. O olhar retrospectivo do ambiente possibilita reflexões prospectivas acerca da espécie de gestão urbana ambiental que necessita ser desenvolvida para garantir a sustentabilidade e conservação ambiental. Assim, este artigo tem por objetivo resgatar as memórias do processo de ocupação ao longo da década de 1960 até a implantação em 2012 da Área de Proteção Ambiental Floresta Manaós. Caracteriza-se por um estudo de caso único, com abordagem qualitativa se utilizando da pesquisa bibliográfica, documental e história de vida. A partir dessa apuração foi possível observar a complexidade em harmonizar os diferentes interesses particulares com a conservação dos ecossistemas existentes, demonstrando o caminho percorrido da emersão de movimentos ambientais que  tinham como foco a defesa territorial e posteriormente se transformando em Ciências Ambientais.
Os Movimentos Indígena e Ambientalista sob o viés de análise da História Ambiental: a repercussão no Ensino de História
Authors: Bicalho Poliene Soares dos Santos , Oliveira Maria de Fátima , Oliveira Fernanda Alves da Silva
Published: July 2020

Este artigo tem por objetivo analisar a relação entre o Movimento Indígena no Brasil e o movimento ambientalista, a partir das contribuições teórico-metodológicas da História Ambiental. Em um primeiro momento, a abordagem desta problemática perpassa os discursos e ações que aproximam os movimentos indígena e ambientalista, em torno das diversas e questionáveis formas de apropriações de terras indígenas, e o desequilíbrio ecológico causado ao meio ambiente nos últimos cinquenta anos, mais especificamente após o Golpe Militar de 1964, data simbólica para esta questão. Em um segundo momento, buscou-se compreender como os problemas ambientais que incidem diretamente sobre as populações indígenas são tratados nos livros didáticos e na escola como um todo, além de procurar entender como têm sido construídos os discursos dos livros didáticos sobre a temática da preservação do meio ambiente, ou seja, como a Educação Ambiental tem sido abordada nas escolas, tendo como foco de análise as terras indígenas.Palavras chave: Movimento Indígena, Movimento Ambientalista, Ensino de História.
Sealing Performance Layered Metal Gasket Based on the Simulation Method
Authors: Karohika I Made Gatot , Haruyama Shigeyuki , Antara I Nyoman Gde , Budiarsa I Nyoman , Penindra I Made Dwi Budiana
Published: July 2020

Studies for corrugated metal gaskets are still ongoing to improve its performance. This is considered to be a single gasket with SUS304 material when contact with flanges that have greater surface roughness, reduced contact width and plastic deformed contact surfaces are incomplete and cannot fill the surface roughness of flanged flanges. The use of softer material than the base material as a surface covering material is used to improve the performance of the gasket. In this study, therefore the effect of modulus of elasticity ratio and thickness ratio on contact width and contact stress, 25A three-layer metal gasket was investigated using Finite Element Analysis. The results showed that the material with tangent modulus, Ehal = Eal / 150 had the highest slope for contact width. While the contact width of the plastic mode gasket is higher than the elastic mode gasket.
Ocalali z potopu. Księga potopu Sydora Reya jako robinsonada holokaustowa
Authors: Janik Gaweł
Published: July 2020

Artykuł stanowi próbę odczytania zbioru opowiadań Księga rozbitków (1959) autorstwa polsko‑żydowskiego pisarza Sydora Reya jako specyficznego rodzaju robinsonady holokaustowej. Autor wskazuje, w jaki sposób utwór poruszający tematykę Zagłady przekształca tradycyjny model Defoe. Zwraca uwagę na zastosowaną w tomie metonimizację Holokaustu, który przedstawiony jest jako katastrofa, kataklizm czy klęska oraz zostaje przyrównany do starotestamentowego potopu. Badacz odczytuje Księgę rozbitków jako realizację robinsonady antyutopijnej, w której klasyczny mit metamorfozy rozbitka nie zostaje zrealizowany, co sprawia, że bohaterowie opowiadań nieustannie balansują na granicy życia i śmierci.
Syberyjscy Robinsonowie
Authors: Kopeć Zbigniew
Published: July 2020

Przedmiotem rozważań są tu bohaterowie polskiej prozy powstałej w XX wieku i pod koniec wieku XIX: powieści Anima Vilis Marii Rodziewiczówny, dwóch utworów Wacława Sieroszewskiego: powieści Na kresach lasów i opowiadania W matni oraz powieści Igora Newerlego Wzgórze błękitnego snu. Łączy je między innymi to, że ich akcja rozgrywa się na Syberii, a także możliwości, jakie mają przed sobą ich bohaterowie. Syberia ukazana jest w sposób daleki od ujęć prezentujących ją „jako największe więzienie świata” czy piekło, do którego zsyłani są Polacy. Pokazana jest jako kraj wielkich możliwości, otwarty na każdego, kto chce i potrafi pracować Bohaterami nie są zesłańcy przedstawieni w duchu martyrologiczno-romantycznym, ale ludzie aktywni, pracowici. Postaci z powieści Rodziewiczówny i Newerlego mają wiele wspólnego z bohaterem Przypadków Robinsona Crusoe. Inaczej rzecz się ma z bohaterami Sieroszewskiego z przywołanych tu utworów, którzy znajdując się na „bezludnej wyspie” będącej zagubioną w tajdze jakucką wioską, nie podejmują typowych dla Robinsona ról. Ważny dla podjętej tu problematyki jest II tom powieści Defoe: Dalsze przygody Robinsona Crusoe, gdzie pokazany jest obraz Syberii kolonizowanej przez Rosjan. W procesie kolonizacji, chcąc nie chcąc, biorą też udział bohaterowie omawianych w pracy utworów.
Robinson w postantropocenie
Authors: Tomczok Marta
Published: July 2020

W artykule podjęto próbę wyjaśnienia związków wyrażenia „Robinson warszawski” z powieścią Robinson Kruzoe Daniela Defoe i współczesnym nawiązaniem do niej w futuresce Dwa końce świata Antoniego Słonimskiego. W części analitycznej wykazano zależność prozy Słonimskiego od wzorca fabularnego oraz eseistyki Jana Kotta i Iana Watta poświęconej przekroczeniu perspektywy indywidualistycznej w powieści europejskiej. W zakończeniu postawiono pytanie o preposteryjną lekturę Dwu końców świata w kontekście koncepcji posthumanizmu Rosi Braidotti.