bluuebunny/crossref_metadata_2025 huggingface dataset:
Iterative reconstruction method for the accurate measurement of optical
transfer function
Authors: Pu Dong , Pan Xingchen , Tao Hua , Liu Cheng , Zhu Jianqiang
Published: August 2021

An iterative computation method was proposed to accurately reconstruct the optical transfer function (OTF) of an imaging lens from a series of recorded images of different patterns displayed on a digital micromirror device (DMD). Since several tens of recorded images are adopted in combination, the measurement noise is remarkably reduced in comparison with the conventional measurement method using a point object, and quite high measurement accuracy is reached by taking the known shape of each tiny mirror of the DMD into computation. While theoretical analysis is demonstrated, the validity of this proposed method is verified both numerically and experimentally.
High-speed multifocus phase imaging in thick tissue
Authors: Xiao Sheng , Zheng Shuqi , Mertz Jerome
Published: August 2021

Phase microscopy is widely used to image unstained biological samples. However, most phase imaging techniques require transmission geometries, making them unsuited for thick sample applications. Moreover, when applied to volumetric imaging, phase imaging generally requires large numbers of measurements, often making it too slow to capture live biological processes with fast 3D index-of-refraction variations. By combining oblique back-illumination microscopy and a z-splitter prism, we perform phase imaging that is both epi-mode and multifocus, enabling high-speed 3D phase imaging in thick, scattering tissues with a single camera. We demonstrate here 3D qualitative phase imaging of blood flow in chick embryos over a field of view of 546 × 546 × 137 µm3 at speeds up to 47 Hz.
Theoretical approach to verify the resonance frequency of a square split ring resonator
Authors: Samanta S. K. , Pradhan R. , Syam D.
Published: August 2021

An analytical model for a square split ring resonator (S-SRR) having a
single split-gap is considered here to reliably estimate the
fundamental resonance frequency of the ring. An S-SRR is assumed to be
equivalent to a series-resonant LC loop. The approximate formulas for
equivalent self-inductance and total capacitance of the ring are
derived separately. The total capacitance of the ring is expressed as
a sum of a gap capacitance and a surface capacitance (which is
associated with charges on the SRR walls). Both the capacitances are
influenced by not only the medium in split-gap but also the dielectric
constant of substrate. These are taken care of by including
appropriate weight factors in the expressions for the capacitances.
Again, using the software CST Microwave Studio, the resonance
frequencies are calculated for several values of split-gap and SRR
side length. Then the results of simulation are compared with the
results obtained from our formula. It is found that simulation results
agree quite well with the analytical results. Also, the analytical
result for resonance frequency of SRR shows good agreement with a
previously published experimental result. This model can be used for
studies of the resonant properties of split rings in the microwave and
terahertz regions.
Nonlinear frequency domain PMD modeling and equalization for nonlinear frequency division multiplexing transmission
Authors: Zhang Xulun , Xi Lixia , Wei Jiacheng , Du Shucheng , Zhang Wenbo , Li Jianping , Zhang Xiaoguang
Published: August 2021

Polarization mode dispersion (PMD) is one of the fundamental properties of a standard single-mode fiber. It affects the propagating signals and degrades the performance of high-speed optical fiber communication systems. PMD also gives an effect on the nonlinear spectra or scattering data in nonlinear frequency division multiplexing (NFDM) systems. However, PMD is usually described in the linear frequency domain, and there are few investigations about the influence of PMD in the nonlinear frequency domain (NFD). An NFD-PMD model is needed to understand the impact of PMD in the NFD. In this work, using a linear approximation method, we first propose an NFD-PMD model and verify its effectiveness. With the guide of the NFD-PMD model, a blind NFD-PMD equalization scheme is designed. The simulation results indicate that the proposed NFD-PMD equalization scheme has better performance than the training sequence method based on linear frequency domain equalization.
Photonic extreme learning machine based on frequency multiplexing
Authors: Lupo Alessandro , Butschek Lorenz , Massar Serge
Published: August 2021

The optical domain is a promising field for the physical implementation of neural networks, due to the speed and parallelism of optics. Extreme learning machines (ELMs) are feed-forward neural networks in which only output weights are trained, while internal connections are randomly selected and left untrained. Here we report on a photonic ELM based on a frequency-multiplexed fiber setup. Multiplication by output weights can be performed either offline on a computer or optically by a programmable spectral filter. We present both numerical simulations and experimental results on classification tasks and a nonlinear channel equalization task.
High-performance refractive index sensing system based on multiple Fano resonances in polarization-insensitive metasurface with nanorings
Authors: Shen Zhe , Du Mengyuan
Published: August 2021

An optical refractive index sensor is a detection device that can convert changes in the refractive index into detectable optical information. The combination of surface plasmon resonance (SPR) and Fano resonance can improve some key indicators, i. e., sensing sensitivity, figure of merit (FOM), band number, and polarization sensitivity, which are all related to the comprehensive performance for high-precision and multi-band sensing. In our manuscript, we proposed a refractive index sensor composed of a nanoring array and a Fabry-Pérot (F-P) resonant cavity. The coupling of the localized surface plasmon resonances (LSPR) of the nanoring array and the cavity mode of the F-P resonant cavity can produce double Fano resonances. The corresponding sensing sensitivities can reach 621.5 nm/RIU and 906.9 nm/RIU, and the corresponding FOMs can reach 119.7 and 119.0. Then we studied the influence of the structure parameters on the sensitivity and FOM of the sensor through simulation calculation and theoretical analysis and verified the insensitivity of the structure to the polarization of incident light. Our structure has high comprehensive performance, not only polarization insensitivity but also high sensing sensitivity and FOM in both bands, which is more suitable for practical applications.
High performance continuous-wave laser cavity enhanced polarimetry using RF-induced linewidth broadening
Authors: Tran Dang-Bao-An , Peverall Robert , Rosson Sarah , Manfred Katherine M. , Ritchie Grant A. D.
Published: August 2021

We present precise optical rotation measurements of gaseous chiral samples using near-IR continuous-wave cavity-enhanced polarimetry. Optical rotation is determined by comparing cavity ring-down signals for two counter-propagating beams of orthogonal polarisation which are subject to polarisation rotation by the presence of both an optically active sample and a magneto-optic crystal. A broadband RF noise source applied to the laser drive current is used to tune the laser linewidth and optimise the polarimeter, and this noise-induced laser linewidth is quantified using self-heterodyne beat-note detection. We demonstrate the optical rotation measurement of gas phase samples of enantiomers of α-pinene and limonene with an optimum detection precision of 10 µdeg per cavity pass and an uncertainty in the specific rotation of ∼0.1 deg dm−1 (g/ml)−1 and determine the specific rotation parameters at 730 nm, for (+)- and (−)-α-pinene to be 32.10 ± 0.13 and −32.21 ± 0.11 deg dm−1 (g/ml)−1, respectively. Measurements of both a pure R-(+)-limonene sample and a non-racemic mixture of limonene of unknown enantiomeric excess are also presented, illustrating the utility of the technique.
Adaptive multi-layer filters incorporated with Volterra filters for impairment compensation including transmitter and receiver nonlinearity
Authors: Arikawa Manabu , Hayashi Kazunori
Published: August 2021

We propose a receiver-side signal processing to compensate for nonlinearity that occurs in transmitter (Tx) and receiver (Rx) components of coherent optical fiber transmission systems. Nonlinear effects in transmission systems are not mutually commutative with any linear effects in general. Considering the order in which all the relevant impairments occur, we adopt a multi-layer (ML) filter architecture. The ML filters consist of strictly-linear and widely-linear filter layers to compensate for relevant linear impairments that occur in a transmission system and two Volterra filter layers to compensate for Rx and Tx nonlinearity. The coefficients of the ML filters including Volterra filter layers are adaptively controlled by using a gradient calculation with back propagation, which is similar to that used in the learning of neural networks, from the last layer and stochastic gradient descent to minimize a loss function that is composed of the last layer outputs. We evaluated the compensation performance of Tx and Rx nonlinearity using the proposed adaptive ML filters including Volterra filter layers both in simulations and experiments of the transmission of a 23 Gbaud polarization-division-multiplexed 64-quadrature amplitude modulation signal over a 100-km single-mode-fiber span. The results demonstrated that the Volterra filter layers in the ML filter architecture could compensate for the nonlinearity that occurs in Tx and Rx simultaneously and effectively even when other impairments such as chromatic dispersion coexist.
Dual-mode Fizeau interferometer with four-step phase-tilting iteration for dynamic optical measurement
Authors: Yu Caiyun , Zong Yi , Duan Mingliang , Li Jianxin
Published: August 2021

For a conventional Fizeau interferometer, accommodating both anti-vibration and conventional measurement modes is a challenge. Here, a dual-mode Fizeau interferometer (DFI) for dynamic optical measurement is proposed, which retains the conventional measurement mode. A vibration information measurement system is added to the conventional Fizeau interferometer for vibration-phase extraction. To better extract the vibration phase, a four-step phase-tilting iteration algorithm is proposed. The two combined systems separate the vibration information while retaining the Fizeau interferometry accuracy. Simulations and experiments prove that the two DFI modes both can accurately recover the phase. Thus, the DFI has considerable application potential for optical topography measurement.
Characterizing spatial uniformity of tensile deformation with an elastic polymer based holographic sensor
Authors: Yu Dan , Liu Qi , Liu Hongpeng , Luo Suhua , Wei Mingzhao , Li Li , Wang Weibo
Published: August 2021

Tensile deformation uniformity of material has been studied with a stretchable polymer based holographic sensor. The diffraction spectrum distribution of a holographic grating with a large area as a main response parameter is scanned. A linear spatial distribution of peak wavelength provides an important foundation for exploring the tensile uniformity. The same ratio of wavelength to position confirms that the tensile deformation of the material is uniform in a small spot size. Over the entire length of the materials, gradually increasing deformation accumulation is the main uniformity feature of tensile deformation. The uniformity response is expected to apply in sensing the deformation and stress fluctuation distribution in the middle of the thin surface. The non-uniform distribution of stress can be expressed by the nonlinear distribution of the grating diffraction spectrum. The optical measurement of tensile deformation uniformity further validates the applicability of a stretchable polymer based holographic sensor.
Occlusion-capable see-through display without the screen-door effect using a photochromic mask
Authors: Chae Minseok , Bang Kiseung , Jo Youngjin , Yoo Chanhyung , Lee Byoungho
Published: August 2021

Conventional occlusion-capable see-through display systems have many practical limitations such as the form factor, narrow field of view, screen-door effect, and diffraction of a real scene. In this Letter, we propose an occlusion-capable see-through display using lens arrays and a photochromic plate. By imaging the occlusion mask on the photochromic plate with near-UV light, the visible light transmittance of the plate changes. Since no black matrix lies on the photochromic plate, our system provides a clear real scene view without the grid structure of the pixels and can prevent diffraction defects of the real scene. We also alleviate the drawback of a narrow field of view using the lens arrays for a reduced form factor.
Dual stage fiber amplifier operating near 3  µm with milijoule-level, sub-ns pulses at 5  W
Authors: Aydin Yiğit Ozan , Magnan-Saucier Sébastien , Zhang Daiying , Fortin Vincent , Kraemer Darren , Vallée Réal , Bernier Martin
Published: August 2021

We report a 2800 nm

E

r

3
+

-doped fluoride fiber amplifier that delivers 1 mJ pulses with an average power of 5 W and pulse duration of 1 ns at 5 kHz repetition rate. To the best of our knowledge, this is the highest pulse energy achieved from a fluoride-fiber-based system operating near 3 µm, and the W-level average power and short pulse lengths make the system a promising tool for biomaterials processing.
High-Q 1D rod-based nanocavities
Authors: Timmerman Dolf , Iwaya Takenori , Fujiwara Yasufumi
Published: August 2021

We report an analysis of one-dimensional rod-based photonic crystal nanocavities. These cavities offer opportunities for dielectric materials which lack a matching low-refractive index substrate or are limited in under-etching possibilities to create slab-based PhC cavities. They offer high theoretical

Q

-values exceeding

10

6

for transverse magnetic polarized modes with modal volumes below

2.5

(
λ

/

n

)
3

. For practical implementations, we propose embedding these structures in a low-refractive index polymer. An analysis of intentionally introduced variations in a rod diameter reveals which design directions should be followed in order to create cavities that are most robust for fabrication-induced variations.
Temporal pulse quality of a Yb:YAG burst-mode laser post-compressed in a multi-pass cell
Authors: Viotti Anne-Lise , Alisauskas Skirmantas , Tünnermann Henrik , Escoto Esmerando , Seidel Marcus , Dudde Katharina , Manschwetus B. , Hartl Ingmar , Heyl Christoph M.
Published: August 2021

Nonlinear pulse post-compression represents an efficient method for
ultrashort, high-quality laser pulse production. The temporal pulse
quality is, however, limited by amplitude and phase modulations
intrinsic to post-compression. We here characterize in frequency and
time domain with high dynamic range individual post-compressed pulses
within laser bursts comprising 100-kHz-rate pulse trains. We
spectrally broaden 730 fs, 3.2 mJ pulses from a Yb:YAG laser in a
gas-filled multi-pass cell and post-compress them to 56 fs. The pulses
exhibit a nearly constant energy content of 78% in the main peak over
the burst plateau, which is close to the theoretical limit. Our
results demonstrate attractive pulse characteristics, making
multi-pass post-compressed lasers very applicable for pump–probe
spectroscopy at, e.g., free-electron lasers or as efficient drivers
for secondary frequency conversion stages.
Fourier-domain full-field optical coherence tomography with real-time axial imaging
Authors: Auksorius Egidijus
Published: August 2021

Fourier-domain full-field optical coherence tomography (FD-FF-OCT) is a fast interferometric imaging technique capable of volumetric sample imaging. However, half of the backscattered light from a sample is lost as it passes through a 50/50 beam splitter, which is at the heart of almost every interferometer. Here, it is demonstrated that this light could be extracted by spatially splitting the illumination pupil plane and detecting it with a separate camera. When a line camera is used to detect the recovered signal, it enables real-time axial imaging of the human cornea in vivo, which serves as a useful visual feedback for aligning a patient for imaging.
Deep diamond single-photon sources prepared by a femtosecond laser
Authors: Gao Si , Tian Zhen-Nan , Yu Pei , Sun Hao-Yu , Fan Hua , Chen Qi-Dai , Sun Hong-Bo
Published: August 2021

Nitrogen-vacancy color centers (NVs) in diamond have several potential applications ranging from quantum computing to data storage. However, artificial NVs are often close to the surface, which limits their spatial density and applicability. Here we demonstrate an effective and precise method for preparing deep single NVs in diamond. The method is based on a spatial-shaped femtosecond laser to overcome laser defocus in high-refractive materials, and realizes the preparation of single NVs at 95 µm. In addition, owing to the good energy distribution of the shaped laser focus, the single NVs exhibit a statistic yield of

56

%
±

11

%

with excellent qualities. This processing method will contribute to the integration of color centers with emerging optical elements and high-density data storage.
Anti-resonant hollow-core fiber fusion spliced to laser gain fiber for high-power beam delivery
Authors: Goel Charu , Li Huizi , Abu Hassan Muhammad Rosdi , Chang Wonkeun , Yoo Seongwoo
Published: August 2021

We present the selective excitation of the fundamental mode in an anti-resonant hollow-core fiber (ARHCF) fusion-spliced with a commercial large mode area (LMA) fiber. By designing and fabricating a single-ring ARHCF that is mode-matched to a LMA fiber and by splicing the two using a

C
O

2

laser-based splicer, we achieve a coupling efficiency of 91.2% into the fundamental mode. We also demonstrate an all-fiber integration of an ARHCF with a commercial ytterbium-doped fiber in a laser cavity for beam delivery application. Coupling of the single-mode laser output beam into the fundamental mode of the ARHCF is demonstrated with 90.4% efficiency (

<

0.45

d
B

loss) for up to 50 W continuous wave beam in a stable and alignment-free all-fiber laser setup.
Si photonic crystal slow-light waveguides optimized through informatics technology
Authors: Hirotani Keisuke , Shiratori Ryo , Baba Toshihiko
Published: August 2021

We modeled the photonic bands of

S
i
O

2

-cladded Si lattice-shifted photonic crystal waveguides via machine learning and found a structure that generates low-dispersion slow light with a group index of approximately 20 in the full C-band at telecom wavelengths. The normalized delay-bandwidth product is as large as 0.45, which is close to the theoretical upper limit. The transition structure between this waveguide and a Si-channel waveguide was designed using an evolutional optimization, and a C-band average loss of 0.116 dB/transition was calculated. These results prove the possibility of further enhancing the versatility of slow light.
Risk for short-term undesirable outcomes in older emergency department users: Results of the ER2 observational cohort study
Authors: Launay Cyrille P. , Galery Kevin , Vilcocq Christine , Afilalo Marc , Beauchet Olivier
Published: August 2021

Background

The "Emergency Room Evaluation and Recommendations" (ER2) is a clinical tool designed to determine prognosis for the short-term Emergency Department (ED) undesirable outcomes including long length of stay (LOS) in ED and in hospital, as well as the likelihood of hospital admission during an index ED visit. It is also designed to guide appropriate and timely tailor-made geriatric interventions. This study aimed to examine whether ER2 assessment part was: 1) usable by ED healthcare workers (e.g. nurses) and 2) scoring system associated with long LOS in ED and in hospital, as well as hospital admission in older ED users on stretchers.

Methods

Based on an observational, prospective and longitudinal cohort study 1,800 participants visiting the ED of the Jewish General Hospital (Montreal, Quebec, Canada) were recruited between September and December 2017. ER2 assessment determined three risk-levels (i.e., low, medium and high) for short-term ED undesirable outcomes. The rate of ER2 digital form completed, the time to fill ER2 items and obtain ER2 risk-levels, the LOS in ED and in hospital, and hospital admission were used as outcomes.

Results

ER2 was usable by ED nurses in charge of older ED users. High-risk group was associated with both increased ED stay (coefficient of regression β = 3.81 with P≤0.001) and hospital stay (coefficient of regression β = 4.60 with P = 0.002) as well as with hospital admission (HR = 1.32 with P≤0.001) when low ER2 risk level was used as referent level. Kaplan-Meier distributions showed that the three risk groups of participants differed significantly (P = 0.001). Those with high-risk level (P≤0.001) were discharged later from hospital to a non-hospital location compared to those with low risk. There was no significant difference between those classified in low-risk and in medium-risk groups (P = 0.985) and those in medium and high-risk groups (P = 0.096).

Conclusion

The ER2 assessment part is usable in daily practice of ED care and its risk stratifications may be used to predict adverse outcomes including prolonged LOS in ED and in hospital as well as hospital admission.

Trial registration

NCT03964311.
Integrating human and ecological dimensions: The importance of stakeholders’ perceptions and participation on the performance of fisheries co-management in Chile
Authors: Franco-Meléndez Milagros , Tam Jorge , van Putten Ingrid , Cubillos Luis A.
Published: August 2021

Increasing attention is paid to the interdependence between the ecological and human dimensions to improve the management of natural resources. Understanding how artisanal fishers see and use the common-pool resources in a co-management system may hold the clue to establishing effective coastal fisheries policies or strengthening existing ones. A more comprehensive planning of the system will also have a bearing on how to reduce conflicts and strengthen social networks. We surveyed artisanal fishers and decision-makers to determine their perceptions about the Management and Exploitation Areas of Benthic Resources (known as MEABR) in Chile’s Biobio region. We performed a field study from November 2018 to August 2019, applying a set of questionnaires to determine the ecological and human attributes that contribute to MEABR outcomes, and then constructed composite scores for those attributes according to a multidimensional scaling technique (“Rapfish”). We find that fishers have different perspectives: surprisingly, women highlighted that the institutional dimension was the most influential on MEABR performance, whereas men highlighted the ecological and economic outcomes. The decision-makers’ role in the MEABR system was considered adequate, but communication and socialization of regulations were irregular. Results also showed that fishers expressed dissatisfaction with illegal fishing practices (poaching), productivity, profits, and conflicts inside and outside the MEABRs. Our study allowed us to better understand how the MEABR has developed in the region. We recommend strengthening local management strategies with particular attention paid to networking among stakeholders, including gender inclusive relationships.
Identification of conserved transcriptome features between humans and Drosophila in the aging brain utilizing machine learning on combined data from the NIH Sequence Read Archive
Authors: Webb Joe L. , Moe Simon M. , Bolstad Andrew K. , McNeill Elizabeth M.
Published: August 2021

Aging is universal, yet characterizing the molecular changes that occur in aging which lead to an increased risk for neurological disease remains a challenging problem. Aging affects the prefrontal cortex (PFC), which governs executive function, learning, and memory. Previous sequencing studies have demonstrated that aging alters gene expression in the PFC, however the extent to which these changes are conserved across species and are meaningful in neurodegeneration is unknown. Identifying conserved, age-related genetic and morphological changes in the brain allows application of the wealth of tools available to study underlying mechanisms in model organisms such as Drosophila melanogaster. RNA sequencing data from human PFC and fly heads were analyzed to determine conserved transcriptome signatures of age. Our analysis revealed that expression of 50 conserved genes can accurately determine age in Drosophila (R2 = 0.85) and humans (R2 = 0.46). These transcriptome signatures were also able to classify Drosophila into three age groups with a mean accuracy of 88% and classify human samples with a mean accuracy of 69%. Overall, this work identifies 50 highly conserved aging-associated genetic changes in the brain that can be further studied in model organisms and demonstrates a novel approach to uncovering genetic changes conserved across species from multi-study public databases.
Proximity can induce diverse friendships: A large randomized classroom experiment
Authors: Rohrer Julia M. , Keller Tamás , Elwert Felix
Published: August 2021

Can outside interventions foster socio-culturally diverse friendships? We executed a large field experiment that randomized the seating charts of 182 3rd through 8th grade classrooms (N = 2,966 students) for the duration of one semester. We found that being seated next to each other increased the probability of a mutual friendship from 15% to 22% on average. Furthermore, induced proximity increased the latent propensity toward friendship equally for all students, regardless of students’ dyadic similarity with respect to educational achievement, gender, and ethnicity. However, the probability of a manifest friendship increased more among similar than among dissimilar students—a pattern mainly driven by gender. Our findings demonstrate that a scalable light-touch intervention can affect face-to-face networks and foster diverse friendships in groups that already know each other, but they also highlight that transgressing boundaries, especially those defined by gender, remains an uphill battle.
Psychological characteristics and the mediating role of the 5C Model in explaining students’ COVID-19 vaccination intention
Authors: Wismans Annelot , Thurik Roy , Baptista Rui , Dejardin Marcus , Janssen Frank , Franken Ingmar
Published: August 2021

To achieve herd immunity against COVID-19, it is crucial to know the drivers of vaccination intention and, thereby, vaccination. As the determinants of vaccination differ across vaccines, target groups and contexts, we investigate COVID-19 vaccination intention using data from university students from three countries, the Netherlands, Belgium and Portugal. We investigate the psychological drivers of vaccination intention using the 5C model as mediator. This model includes five antecedents of vaccination: Confidence, Complacency, Constraints, Calculation and Collective Responsibility. First, we show that the majority of students have a positive propensity toward getting vaccinated against COVID-19, though only 41% of students are completely acceptant. Second, using the 5C model, we show that ‘Confidence’ (β = 0.33, SE = 03, p < .001) and ‘Collective Responsibility’ (β = 0.35, SE = 04, p < .001) are most strongly related to students’ COVID-19 vaccination intention. Using mediation analyses, we show that the perceived risk and effectiveness of the vaccine as well as trust in the government and health authorities indirectly relate to vaccination intention through ‘Confidence’. The perceived risk of COVID-19 for one’s social circle and altruism, the need to belong and psychopathy traits indirectly relate to vaccination intention through ‘Collective Responsibility’. Hence, targeting the psychological characteristics associated with ‘Confidence’ and ‘Collective Responsibility’ can improve the effectiveness of vaccination campaigns among students.
Efficiency of tourism development in China’s major cities under the constraint of PM2.5
Authors: Li Jiajia , Duan Kaifeng , Xu Quanwei , Sun Xuefei , Zhang Yanwei , Hua Changhua
Published: August 2021

Climate / weather factors are important factors for tourists to choose tourist destinations. With the public’s attention to the influence of haze, air quality will have a profound impact on the development of tourism in tourist destinations. Based on the Epsilon-based Measure (EBM) super-efficiency model and Global Malmquist–Luenberger index analysis method, this paper aims to study the tourism development efficiency of 58 major cities in China from 2001 to 2016 and analyse the total factor productivity in the development of urban tourism and the changing driving factors in consideration of the undesirable output of haze characterised by PM2.5 emission concentration. The study findings show that the overall efficiency of tourism development of 58 cities is not high in 2001–2016, but the tourism development efficiency of all cities is increasing year by year. Under the constraint of haze, the efficiency of urban tourism development is not directly proportional to the degree of urban development. The overall redundancy rate of each input index is slightly high, and the redundancy of PM2.5 emission concentration has a considerable effect on the efficiency of urban tourism development. The overall change trend in total factor productivity in the development of urban tourism is improved, mainly due to the improvement of technological progress factors. On this basis, the corresponding policy implications are concluded according to high-efficiency and high-quality development of tourism in 58 major cities.
Predictors for regression and progression of intestinal metaplasia (IM): A large population-based study from low prevalence area of gastric cancer (IM-predictor trial)
Authors: Aumpan Natsuda , Vilaichone Ratha-korn , Pornthisarn Bubpha , Chonprasertsuk Soonthorn , Siramolpiwat Sith , Bhanthumkomol Patommatat , Nunanan Pongjarat , Issariyakulkarn Navapan , Ratana-Amornpin Sarita , Miftahussurur Muhammad , Mahachai Varocha , Yamaoka Yoshio
Published: August 2021

Background

Gastric intestinal metaplasia (IM) can lead to gastric cancer. Until now, there have been limited studies of predictors for regression and progression of IM. This study aimed to determine risk factors associated with regression or progression of IM for guiding proper management and prevention of gastric cancer.

Methods

2,025 patients undergoing gastroscopy in Thammasat University Hospital, Thailand were enrolled during September 2017-August 2019. Patients’ data including baseline characteristics, laboratory results, and histopathology of gastric biopsies from University medical database were extensively reviewed.

Results

2,025 patients had mean age of 61.3 years and 44.2% were males. Overall H. pylori prevalence was 47.5%. There were 1,551(76.6%) patients with chronic gastritis and 361(17.8%) with IM. Of 400 patients with chronic gastritis having follow-up endoscopy and repeated gastric biopsies, 104(26%) had persistent H. pylori infection and 27(26%) developed IM during mean follow-up time of 24 months. Persistent H. pylori infection was significantly associated with development of IM (OR 3.16, 95%CI 1.56–6.39, p = 0.001). Regression, persistence, and progression of IM were demonstrated in 57.3%, 39.2%, and 3.5% of patients, respectively. Age >65 years, persistent H. pylori infection, and diabetes mellitus were significantly associated with persistent IM or progression to dysplasia with OR 2.47(95%CI 1.33–4.61, p = 0.004), OR 2.64(95%CI 1.13–6.18, p = 0.025), and OR 2.54(95%CI 1.16–5.54, p = 0.019), respectively. Patients without H. pylori infection had more IM regression than patients with persistent infection (60.4%vs.39.4%, p = 0.035). Patients with persistent H. pylori infection significantly had higher IM progression to dysplasia (15.2%vs.2.1%; OR 11.15, 95%CI 1.18–105.24, p = 0.035) than noninfected. During 24 months of study, 30 patients (1.5%) were diagnosed with gastric cancer.

Conclusion

Regression of IM could be achieved by successful H. pylori eradication. Persistent H. pylori infection was significantly associated with development and progression of IM to dysplasia. Age >65 years and diabetes mellitus were also significant predictors for IM progression.
Performance evaluation of e-commerce firms in China: Using three-stage data envelopment analysis and the Malmquist productivity index
Authors: Zheng Sufang , Khan Rabnawaz
Published: August 2021

As a new business form of international trade and electronic commerce, e-commerce has been a controversial topic that has attracted the attention of scholars and industry professionals. This study estimated the operating efficiency and total factor productivity (TFP) of listed e-commerce firms in China from 2015 to 2019. Three related methodologies were applied: data envelopment analysis (DEA), the Malmquist TFP index, and stochastic frontier analysis. The DEA analysis results showed that environmental variables exerted a substantial effect on technical efficiency. Most firms demonstrated effective technical efficiency after adjustment for input variables. Business-to-business firms had the highest operating efficiency, followed by business-to-consumer and production-to-consumer firms. Technical progress and scale were identified as two major factors affecting improvement in TFP. Hence, e-commerce firms should make full use of advanced technology and aim to achieve economies of scale.
Growth-profile configuration for specific deformations of tubular organs: A study of growth-induced thinning and dilation of the human cervix
Authors: Gou Kun , Baek Seungik , Lutnesky Marvin M. F. , Han Hai-Chao
Published: August 2021

Growth is a significant factor that results in deformations of tubular organs, and particular deformations associated with growth enable tubular organs to perform certain physiological functions. Configuring growth profiles that achieve particular deformation patterns is critical for analyzing potential pathological conditions and for developing corresponding clinical treatments for tubular organ dysfunctions. However, deformation-targeted growth is rarely studied. In this article, the human cervix during pregnancy is studied as an example to show how cervical thinning and dilation are generated by growth. An advanced hyperelasticity theory called morphoelasticity is employed to model the deformations, and a growth tensor is used to represent growth in three principle directions. The computational results demonstrate that both negative radial growth and positive circumferential growth facilitate thinning and dilation. Modeling such mixed growth represents an advancement beyond commonly used uniform growth inside tissues to study tubular deformations. The results reveal that complex growth may occur inside tissues to achieve certain tubular deformations. Integration of further biochemical and cellular activities that initiate and mediate such complex growth remains to be explored.
Translation, reliability, and validity of Japanese version of the Respiratory Distress Observation Scale
Authors: Sakuramoto Hideaki , Hatozaki Chie , Unoki Takeshi , Aikawa Gen , Kobayashi Shunsuke , Okamoto Saiko , Shimomura Shinichi , Kawasaki Ayako , Fukui Miwako
Published: August 2021

Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases and is defined as “a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity.” However, Japanese intensive care units (ICUs) do not routinely screen for dyspnea, as no validated Japanese version of the Respiratory Distress Observation Scale (RDOS) is available. Therefore, we aimed to translate the English version of this questionnaire into Japanese and assess its validity and reliability. To translate the RDOS, we conducted a prospective observational study in a 12-bed ICU of a universal hospital that included 42 healthcare professionals, 10 expert panels, and 128 ventilated patients. The English version was translated into Japanese, and several cross-sectional web-based questionnaires were administered to the healthcare professionals. After completing the translation process, a validity and reliability evaluation was performed in the ventilated patients. Inter-rater reliability was evaluated using Cohen’s weighted kappa coefficient. Criterion validity was ascertained based on the correlation between RDOS and the dyspnea visual analog scale. The area under the receiver operating characteristic curve analysis was used to evaluate the ability of the RDOS to identify patients with self-reported dyspnea. The average content validity index at the scale level was 0.95. Data from the 128 patients were collected and analyzed. Cohen’s weighted kappa coefficient and the correlation coefficient between the two scales were 0.76 and 0.443 (95% confidence intervals 0.70–0.82 and 0.23–0.62), respectively. For predicting self-reported dyspnea, the area under the receiver operating characteristic curve was 0.81 (95% confidence interval 0.67–0.97). The optimal cutoff used was 1, with a sensitivity and specificity of 0.89 and 0.61, respectively. Our findings indicated that the Japanese version of the RDOS is acceptable for face validity, understandability, criterion validity, and inter-rater reliability in lightly sedated mechanically ventilated patients, indicating its clinical utility.
Effect of an intensive cervical traction protocol on mid-term disability and pain in patients with cervical radiculopathy: An exploratory, prospective, observational pilot study
Authors: Rulleau Thomas , Abeille Sophie , Pastor Lydie , Planche Lucie , Allary Pascale , Chapeleau Catherine , Moreau Chloé , Cormier Grégoire , Caulier Michel
Published: August 2021

Background

Cervical radiculopathy is a relatively common and disabling condition involving local pain in the neck region and pain that radiates into the upper limb. Recent data suggest that cervical traction may effectively reduce disability and pain, with a dose-response relationship. The main aim of this study was therefore to evaluate the mid-term effect of an intensive cervical traction protocol for patients with cervical radiculopathy on disability, and to compare the effects with those reported by non-intensive protocols in the literature.

Methods

We conducted a prospective open observational study of 36 patients referred by their general practitioner for symptoms suggestive of cervical radiculopathy. All patients underwent the same treatment: a 30-minute cervical traction protocol, twice a day, for five consecutive days. The main objective was the evaluation of disability at 3 months. We evaluated at baseline (D1), the end of the protocol (D5) and at mid-term (M3) disability, cervical pain, radiating pain, pain on motor imagery, presence of neuropathic pain and medication consumption. The primary outcome was the proportion of patients for whom the Neck Disability Index improved by more than the minimum clinically important difference of 7 points by M3.

Results

Thirty-six patients were included in this study. The Neck Disability Index improved by more than the minimum clinically important difference in 48.3% at M3. Mean Neck Disability Index (p < .001), mean cervical VAS (p < .001), mean radiating VAS (p < .001), and mean VAS for imagined lateral flexion and rotation (p < .002) improved significantly from D1 to D5 and from D1 to M3. Consumption of medication reduced at each time point. The proportion of patients with neuropathic pain reduced from 61.1% at D1 to 33.3% at D5 and 48.3% at M3.

Conclusion

Disability reduced by more than the minimum clinically important difference in almost half of the participants following the intensive traction protocol. These results are encouraging and suggest that this complex condition can be treated with relatively simple methods.
Outcome after Modified Maquet Procedure in dogs with unilateral cranial cruciate ligament rupture: Evaluation of recovery limb function by use of force plate gait analysis
Authors: Della Valle Giovanni , Caterino Chiara , Aragosa Federica , Micieli Fabiana , Costanza Dario , Di Palma Cristina , Piscitelli Alfonso , Fatone Gerardo
Published: August 2021

Introduction

Cranial cruciate ligament failure is one of the principal causes of canine lameness. Several surgical procedures were proposed to achieve joint stabilisation; among these, the Modified Maquet Procedure involves using a titanium foam wedge to achieve and maintain the tibial tuberosity advancement. The force-plate analysis provides to objectively assess normal and abnormal gait and the outcome of different surgical techniques. The study evaluates the outcome of limbs that underwent Modified Maquet Procedure using land-force plate analysis comparing the operated limb with its healthy contralateral one as a control.

Materials and methods

Thirty-five dogs with unilateral cranial cruciate ligament rupture were evaluated. Outcome after surgery was assessed by orthopaedic and radiographic evaluations and force plate gait analysis performed before surgery, at 15, 30 and 90 days after surgery. For objective comparison of ground reaction forces, data of operated limb were compared to contralateral limb on each time control and Symmetry Index at 90 days was determined. Healing radiographic signs, minor and major complication were reported.

Results

A significant improvement in ground reaction forces was reached in all the treated limbs between set time intervals. The median percentage increase in ground reaction forces was constant from 15 to 90 days, with a Symmetry Index >9 in 54.2% of patients suggesting a normal gait symmetry. A complete bone healing was noticed at 90 days follow-up radiographic assessment. We experienced three major (8.5%) and one minor (2.8%) complications.

Conclusions

To the Authors’ knowledge, this is the first study in the veterinary literature that assessed outcomes of dogs undergoing Modified Maquet Procedure for the treatment of cranial cruciate ligament rupture using force plate gait analysis and healthy contralateral limb as a control group. Our results confirm that Modified Maquet Procedure is an effective method to stabilise the stifle joint.
Insight into the bacterial communities of the subterranean aphid Anoecia corni
Authors: Fakhour Samir , Renoz François , Ambroise Jérôme , Pons Inès , Noël Christine , Gala Jean-Luc , Hance Thierry
Published: August 2021

Many insect species are associated with bacterial partners that can significantly influence their evolutionary ecology. Compared to other insect groups, aphids harbor a bacterial microbiota that has the reputation of being poorly diversified, generally limited to the presence of the obligate nutritional symbiontBuchnera aphidicolaand some facultative symbionts. In this study, we analyzed the bacterial diversity associated with the dogwood-grass aphidAnoecia corni, an aphid species that spends much of its life cycle in a subterranean environment. Little is known about the bacterial diversity associated with aphids displaying such a lifestyle, and one hypothesis is that close contact with the vast microbial community of the rhizosphere could promote the acquisition of a richer bacterial diversity compared to other aphid species. Using 16S rRNA amplicon Illumina sequencing on specimens collected on wheat roots in Morocco, we identified 10 bacterial operational taxonomic units (OTUs) corresponding to five bacterial genera. In addition to the obligate symbiontBuchnera, we identified the facultative symbiontsSerratia symbioticaandWolbachiain certain aphid colonies. The detection ofWolbachiais unexpected as it is considered rare in aphids. Moreover, its biological significance remains unknown in these insects. Besides, we also detectedArsenophonusandDactylopiibacterium carminicum. These results suggest that, despite its subterranean lifestyle,A.cornishelter a bacterial diversity mainly limited to bacterial endosymbionts.
Seeing the point for the line: Shakir Hassan Al Saʾid’s contemplative concept of the artwork
Authors: Al-Bahloly Saleem
Published: August 2021

This article details how existential phenomenology, mystical theology and abstraction came together in the practice of Shakir Hassan Al Saʿid in the 1960s in order to produce a grammar of experience that might establish some human relationship to a universe rendered meaningless by scientific developments.
The art of nature in Iraq’s marshes: Images of the occupation
Authors: Guarasci Bridget
Published: August 2021

In August 2003, Iraqi exile Zaid Kubra returned to Baghdad to restore and conserve the country’s marshes, once drained by Saddam Hussein, as the signature emblem for the new state. Under Kubra’s leadership Iraq’s marshes conservation initiative became the ‘success story of the war’. Photographic images of Iraq’s restored marshes were potent markers of this success, used by more than 75 news articles since 2003 to fuel special interest good news reportage. Through a comparative of occupation imagery with the Iraqi canon of literary and visual arts centring on the marshes, the article analyses how Iraqi exiles cultivated an occupation aesthetics of the marshes that deployed images of wetlands’ nature – its towering reeds and its soaring birds – to advance the occupation.
Representation and identity: Reflections on presenting contemporary art in an American museum
Authors: Katrib Ruba
Published: August 2021

This text is a curatorial reflection upon the process of organizing the exhibition Theater of Operations: The Gulf Wars 1991–2011, which took place at MoMA PS1 in 2019. The text questions the possibilities and limits of decolonial curating in an American museum and analyses the reception of Iraqi contemporary art in a Western context.
Dynamic change of blood profile in rat models with acute skin injury artificially infected with methicillin-resistant Staphylococcus aureus
Authors: Prakoso Yos Adi , Hidayah Nurul , Rini Chylen Setiyo , Kurniasih Kurniasih
Published: August 2021

Background and Aim: A wound is a common problem for humans and animals. The wound becomes more severe if it is infected by bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). The wound healing mechanism involves various factors, either in the local tissue or the bloodstream. However, the presentation of infected wound healing regarding its impacts on the dynamic change of blood profile is not clearly understood. This study aimed to explore the impacts of wound creation on the blood profile in rat models with and without being artificially infected by MRSA.

Materials and Methods: Thirty male Sprague-Dawley rats (6 months old; weight, 300 g) were used as the model. They were divided into three groups: Without wound creation (C), wounded without infection (CW), and wounded and artificially infected by MRSA (CWI). Groups CW and CWI were shaved and induced with 4 mm two-round full-thickness biopsy on the back. Furthermore, group CWI was artificially infected by 105 colony-forming units of MRSA. The blood samples were collected through the tail vein from days 1 to 5. The blood parameters included blood profile, total plasma protein, C-reactive protein, CD4+, CD8+, CD4+/CD8+, and COX-2. The data were analyzed using the Statistical Package for the Social Sciences, version 16 (SPSS, IBM, Armonk, NY, USA).

Results: The result showed that the presentation of a wound with and without MRSA infection significantly changed the total erythrocytes, leukocytes, neutrophils, lymphocytes, total plasma protein, C-reactive protein, and the subset of circulatory CD4+, CD8+, and COX-2 (p≤0.05). In addition, the wound infected with MRSA impacts the mean corpuscular volume (p≤0.05).

Conclusion: Moreover, the presentation of the wound with and without MRSA infection induces dynamic changes on various blood profile parameters.