bluuebunny/crossref_metadata_2025 huggingface dataset:
Empowered or powerless? Contributing factors to women's appraisal of traumatic childbirth
Authors: Baptie Grace , Januário Elena Mueller , Norman Alyson
Published: December 2021

Background

Approximately one-third of women reflect on childbirth as a traumatic experience and the way women appraise their birth experience is significant to their postnatal wellbeing. This study aimed to identify and compare experiences of childbirth for mothers who reflect on birth as a traumatic or non-traumatic event.

Methods

Semi-structured interviews were conducted with 14 mothers in the postpartum period who appraised their birth as either traumatic or non-traumatic. The data were analysed using thematic analysis to elicit themes and subthemes.

Results

Thematic analysis revealed two contrasting themes relating to whether women felt empowered or powerless during birth. Empowerment was associated with women's trust in their maternity care, the sense of control they felt over their body and birth and the extent to which they felt informed of their options. Being powerless was associated with distrust towards healthcare services, feeling as though they lacked control over the process and feeling ‘in the dark’ about what was happening.

Conclusions

Women's sense of empowerment during birth is an important contributor to the appraisal of childbirth as a traumatic or non-traumatic experience. Empowerment is largely determined by the dynamic between a mother and the support around her.
Residential Care Controversy: The Promise of the UN Convention on the Rights of Persons with Disabilities to Protect All Children
Authors: Rosenthal Eric
Published: December 2021

Conflicting interpretations of the Convention on the Rights of the Child (CRC) and Convention on the Rights of Persons with Disabilities (CRPD) send mixed messages on the safety and legitimacy of residential care, resulting in the replacement of large institutions with smaller ones, often called ‘residential care’ or 'group homes.' The CRPD requires governments to create protections and supports to allow all people with disabilities to live in the community. CRPD Committee General Comment No. 5 says that, for children, living in the community means growing up in a family – not in a large or small facility. This article demonstrates how the family inclusion mandate of General Comment No. 5 is rooted in the 'human rights model of disability,' fundamental to equal protection under the CRPD for all children with actual or perceived disabilities. The article proposes solutions to ensure full implementation of both the CRC and CRPD.
Off-axis optical scanning holography [Invited]
Authors: Zhang Yaping , Yao Yongwei , Zhang Jingyuan , Liu Jung-Ping , Poon Ting-Chung
Published: December 2021

Optical scanning holography (OSH) involves the principles of optical scanning and heterodyning. The use of heterodyning leads to phase-preserving, which is the basic idea of holography. While heterodyning has numerous advantages, it requires complicated and expensive electronic processing. We investigate an off-axis approach to OSH, thereby eliminating the use of heterodyning for phase retrieval. We develop optical scanning theory for holographic imaging and show that by properly designing the scanning beam, we can perform coherent and incoherent holographic recording. Simulation results are provided to verify the proposed idea.
Frequency response measurement of electro-optic phase modulators using the time-frequency analysis method
Authors: Yang Hongzhi , Gao Yuan , Wang Lei , Wang Sijia , Qing Peng , Mao Yefei , Zhang Ziyue , Zhou Ju
Published: December 2021

We propose a novel method for the frequency response measurement of electro-optic phase modulators by time-frequency analyzing the instantaneous frequency of a sinusoidal frequency-modulated (SFM) signal. The SFM signal is generated by a frequency-shifting loop (FSL) in which the electro-optic phase modulator under test generates a dual-sideband frequency shift per roundtrip. And the bandwidth of the generated SFM signal is dozens of times of the input radio-frequency (RF), which makes it a precise method to measure the frequency response of electro-optic phase modulators at lower cutoff frequencies. Based on the previously proposed time-delayed interference model [H. Yang et al., J. Lightwave Technol. 39, 3112 (2021)10.1109/JLT.2021.3059875], we establish the relationship between the “peak-to-peak” frequency of the SFM waveforms and the modulation index of the phase modulators. And a short-time Fourier transformation (STFT) is adopted to characterize the time-frequency properties of output waveforms. Experimental results are well supported by the simple theoretical model. Finally, the accuracy of the half-wave voltage measurement is discussed.
Optimal modes for spatially multiplexed free-space communication in atmospheric turbulence
Authors: Belmonte Aniceto , Kahn Joseph M.
Published: December 2021

In near-field free-space optical (FSO) communication, spatial-mode multiplexing (SMM) increases transmission capacity by transmitting independent information streams in orthogonal modes. Propagation through atmospheric turbulence causes phase and amplitude distortions that can degrade SMM performance. In this paper, we show there exist optimal modes for transmission through turbulence with minimum degradation, under a realistic assumption that a transmitter knows the turbulence statistics but not the instantaneous state of the atmosphere. These modes are determined by performing a Karhunen-Loève expansion of the optical electric field in the receiver aperture. We show that these modes are Laguerre-Gauss (LG) modes whose beam waist is chosen depending on the field coherence length in the receiver plane. These adaptive-waist LG modes, when ordered by decreasing eigenvalue, can approximate a received signal field by a finite number of modes with lowest mean-square error among all orthonormal mode sets. Hence, they represent optimal transmit and receive bases for SMM FSO. Using numerical simulation, we study SMM FSO transmission at various turbulence strengths and signal-to-noise ratios. We compare the performance using the adaptive-waist LG modes to that using fixed-waist LG modes (which assume no knowledge of turbulence statistics) and instantaneous eigenmodes (which assume knowledge of the instantaneous state of the turbulence). We also study the performance using the orbital angular momentum subsets of the adaptive-waist LG mode and fixed-waist LG mode sets.
Integrated InP optical unitary converter with compact half-integer multimode interferometers
Authors: Tanomura Ryota , Tang Rui , Tanemura Takuo , Nakano Yoshiaki
Published: December 2021

Integrated optical unitary converters (OUCs) are vital devices for various emerging applications such as mode-multiplexed optical communication, optical neural networks, and quantum computing. In order to realize large-scale OUCs in a limited footprint, the number of elements, as well as the size of each element, is important. In this work, we present a novel type of OUC using half-integer multimode interferometers (MMIs) based on the multi-plane light conversion (MPLC) concept. A half-integer MMI enables unitary coupling among the multiple input and output ports, while requiring only half the length of a conventional uniform MMI. Although the splitting ratio is not uniform across the ports, we show both numerically and experimentally that arbitrary unitary operation can still be achieved with comparable performance. We fabricate 4×4 OUC with half-integer MMIs on the monolithic InP platform and experimentally demonstrate reconfigurable 4-mode sorting and switching with a significantly reduced footprint compared with the conventional OUCs using uniform MMIs.
Magneto-optical imaging of coherent spin dynamics in ferrites
Authors: Petrov P. E , Kapralov P. O , Knyazev G. A , Kuzmichev A. N , Vetoshko P. M , Bunkov Yu. M , Belotelov V. I
Published: December 2021

The explosive development of quantum magnonics is associated with the possibility of its use as macroscopic quantum systems. In particular, they can find an application for quantum computing processors and other devices. The recently discovered phenomenon of magnon Bose-Einstein condensation and coherent precession of magnetization can be used for these purposes. Our letter describes a method for the optical observation of the coherently precessing magnetization in conditions when the concentration of magnons reaches the value necessary for their quantum condensation. The investigations were conducted in the out-of-plane magnetized yttrium iron garnet films. The required magnon density was achieved by magnetic resonance technique. The magneto-optical imaging method provides such important parameters of the coherent spin dynamics as the amplitude and phase distributed all over the sample. It should become an indispensable read-out tool for the upcoming quantum technologies based on the magnon Bose-Einstein condensation.
Phase-change metasurface for switchable vector vortex beam generation
Authors: Cai Ziru , Wu Cuo , Jiang Jing , Ding Yingtao , Zheng Ziwei , Ding Fei
Published: December 2021

Metasurfaces have attracted increasing attention due to their unprecedented capabilities of molding optical fields with exceedingly low losses. Despite significant achievements, most existing metasurfaces are passive and lack dynamic modulation post-fabrication. Here, we propose a tunable phase-change metasurface for switchable vector vortex beam generation in the mid-infrared range. The phase-change meta-molecule, consisting of two coupled Ge2Sb2Te5 (GST) bricks, is firstly designed to perform the switching between a quarter-wave plate and a usual transmissive plate over a wavelength range from 4.95 to 5.05 µm under the amorphous and crystalline phases of GST, respectively. Furthermore, a general method is derived to achieve a switchable vector vortex beam generator at the target wavelength of 5 µm by spatially orienting GST meta-molecules to locally tailor phase and polarization distribution. Under the amorphous phase, radially polarized and azimuthally polarized beams, composed of the co-polarized circularly polarized (CP) component carrying orbital angular momentum (OAM) with a topological charge of l = 0 and cross-polarized CP component carrying OAM with a topological charge of l = ±2 are obtained for the left circularly polarized (LCP) and right circularly polarized (RCP) incident waves, respectively. The mode purity values of the cross-polarized component and the co-polarized component are calculated to be ∼ 0.949 and ∼ 0.955. When GST transits to its crystalline phase, the vector vortex beam disappears, and the incident CP beams pass through directly. Our finding paves the way for advanced applications targeting photonics integration with switchable functionalities.
Van der Waals materials as dielectric layers for tailoring the near-field photonic response of surfaces
Authors: Grasseschi D. , Bahamon D. A. , Maia F. C. B. , Barcelos I. D. , Freitas R. O. , de Matos C. J. S.
Published: December 2021

Epsilon near-zero photonics and surface polariton nanophotonics have become major fields within optics, leading to unusual and enhanced light-matter interaction. Specific dielectric responses are required in both cases, which can be achieved, e.g., via operation near a material’s electronic or phononic resonance. However, this condition restricts operation to a specific, narrow frequency range. It has been shown that using a thin dielectric layer can adjust the dielectric response of a surface and, therefore, the operating frequency for achieving specific photonic excitations. Here, we show that a surface’s optical properties can be tuned via the deposition/transference of ultra-thin layered van der Waals (vdW) crystals, the thicknesses of which can easily be adjusted to provide the desired response. In particular, we experimentally and theoretically show that the surface phonon resonance of a silica surface can be tuned by ∼50 cm−1 through the simple deposition of nanometer-thick exfoliated flakes of black phosphorus. The surface properties were probed by infrared nanospectroscopy, and results show a close agreement with the theory. The black phosphorus-silica layered structure effectively acts as a surface with a tunable effective dielectric constant that presents an infrared response dependent on the black phosphorus thickness. In contrast, with a lower dielectric constant, hexagonal boron nitride does not significantly tune the silica surface phonon polariton. Our approach also applies to epsilon near-zero surfaces, as theoretically shown, and to polaritonic surfaces operating at other optical ranges.
In-situ adjustable fiber-optic piezometer based on parallelly structured external Fabry-Perot interferometers with Vernier effect and its harmonics
Authors: Wang Shun , Yang Yaowen , Wu Lei , Mohanty Lipi , Jin Rui-Bo , Zhang Liang , Lu Peixiang
Published: December 2021

Translating interferometric applications into practical field use with the required flexible precision and measurement range, is a recognized challenge. We report an in-situ adjustable fiber-optic piezometer based on parallelly structured external Fabry-Perot interferometers (EFPIs) with the Vernier effect and its harmonics. By accommodating the EFPI structure with an adjustable and a fixed cavity length, the EFPIs are utilized as a referencing fiber piezometer (RFP), and a sensing fiber piezometer (SFP), respectively. The Vernier effect with amplified sensitivity is formed by connecting the RFP and SFP in parallel via a 3 dB optical coupler. By simply tuning the cavity length of the RFP, the magnification factor M of the Vernier effect is in-situ continuously adjustable. Using the two prototypes SFP1 and SFP2, water level measurement is performed in the fundamental Vernier effect (FVE) mode and the harmonic Vernier effect (HVE) mode. Experimental results demonstrate that in the FVE mode, the sensitivity can be predictably tuned from −0.15 nm/cm to −7.02 nm/cm with M=1∼48 for SFP1, and −0.31 nm/cm to −7.22 nm/cm with M=1∼23 for SFP2. In the HVE mode, the sensitivity can be further enhanced as high as −9.08 nm/cm, while the sensing performance fluctuates during the adjusting process. Benefiting from the merits of in-situ adjustable sensitivity and measurement range, simplicity of composition, robustness, and remote sensing capability, the proposed scheme can be applied to various practical applications.
Scalar vortex beam produced through faithful reconstruction of polarization holography
Authors: Zheng Shujun , Liu Hongjie , Lin Ayuan , Xu Xianmiao , Ke Shenghui , Song Haiyang , Zhang Yuanying , Huang Zhiyun , Tan Xiaodi
Published: December 2021

Vortex beams have been widely analyzed and applied in various fields owing to their unique phase and intensity distribution, along with their orbital angular momentum; they can be produced through various methods. This study proposes a method based on polarization holography, contrary to the traditional method of producing vortex beams. This method is significant in that the signal wave in the recording stage is not the generated vortex beam; the reconstructed wave is the vortex beam obtained in the reconstruction stage, which varies from the vortex beams produced by holography, where the signal wave is already a vortex beam. Faithful reconstruction of polarization holography is applied in the experiment, where phenanthrenequinone-doped polymethyl methacrylate (PQ/PMMA) photopolymers are used as the recording material. Scalar vortex beams with arbitrary linear polarization and topological charges can be produced by changing the experimental parameters. The experimental results are satisfactory. Additionally, this work demonstrates the application of polarization holography in light field manipulation. This proposed method has potential applications in optical micro-manipulation and optical tweezers.
Simplified twin-single-sideband direct detection system separating left and right sideband signals using a digital signal processing algorithm instead of optical bandpass filters
Authors: Zhou Ye , Xiao Jiangnan , Zhao Chuang , Zuo Jiangli , Ming Jun , Zhao Li
Published: December 2021

Twin-single-sideband (twin-SSB) signals can be generated based on an in-phase– quadrature (I/Q) modulator, and two independent left sideband (LSB) and right sideband (RSB) signals carry individual data to effectively harvest the advantage of twin-SSB modulation, which achieves higher spectral efficiency. However, the conventional twin-SSB scheme employs two optical bandpass filters (OBPFs) and two photodetectors (PDs) for complete separation and detection at the receiver side. To mitigate the crosstalk between RSB and LSB signals and reduce the complexity and cost of the twin-SSB system, we propose a new scheme to realize twin-SSB without OBPFs separating LSB and RSB signals by a single-ended PD to improve system performance. According to the beating characteristics of the LSB and RSB, we can separate two independent sideband signals using a digital signal processing (DSP) algorithm added to the receiver end. Our simulation results demonstrate that our proposed scheme can obtain good bit error ratio (BER) performance of LSB and RSB signals. We designed a twin-SSB system with different modulation formats in the two sidebands, adopting geometric shaping 3PSK (GS-3PSK) modulation for the LSB and quadrature phase shift keying (QPSK) modulation for the RSB. The BER of the LSB GS-3PSK and RSB QPSK signal can reach hard-decision forward error correction (HD-FEC) when the received optical power (ROP) was > −17.5 and > −16 dBm, respectively, at different baud rates of 1-, 2-, and 4-Gbaud with a carrier frequency of 12-GHz over 10-km standard single-mode fiber (SSMF) transmission. For an 8-Gbaud baud rate with a carrier frequency of 12-GHz over 5-km SSMF transmission, the BER of the two sideband signals can still be below the HD-FEC threshold of 3.8 × 10−3 when the ROP was > −17 and > −16 dBm, respectively.
Multicomponent trace gas detection with hollow-core fiber photothermal interferometry and time-division multiplexing
Authors: Liu Fei , Bao Haihong , Ho Hoi Lut , Jin Wei , Gao Shoufei , Wang Yingying
Published: December 2021

We report a multicomponent photothermal gas sensor with a conjoined-tube hollow-core optical fiber gas cell. With a common Fabry-Perot probe interferometer and a common gas cell, simultaneous detection of methane, acetylene and ammonia can be achieved by time-division multiplexing. Experiments with a 15-cm-long hollow-core fiber demonstrated noise-equivalent concentration of 24.2 parts-per-billion (ppb) for methane, 11.6 ppb for acetylene, and 46.1 ppb for ammonia. The dynamic range is measured to be around 5 orders of magnitude. The crosstalk issue is addressed by spectrum fitting. Assisted with an air pump and a compact gas chamber, the response time of less than 10 s is achieved.
Efficient high-energy Raman soliton generation in a Tm:doped large mode area fiber amplifier
Authors: Richter Roland A. , Tolstik Nikolai , Sorokina Irina T.
Published: December 2021

We report the Tm-doped all-fiber MOPA based on a LMA active fiber generating Raman solitons tunable in the range 1970-2300 nm directly from the LMA fiber. By tuning the chirp of the input pulse we reached more than 90 % energy transfer efficiency to Raman soliton. Solitons with 125 fs duration and up to 24 nJ energy are demonstrated in LMA fiber amplifier. We show experimentally that Raman solitons experience both amplification and absorption in active fiber components of the laser system and that the energy of a Raman soliton generated in an LMA fiber amplifier is limited by the soliton area theorem.
Transversal and axial modulation of axicon-generated Bessel beams using amplitude and phase masks for glass processing applications
Authors: Dudutis Juozas , Mackevičiūtė Miglė , Pipiras Jokūbas , Stonys Rokas , Stankevič Valdemar , Račiukaitis Gediminas , Gečys Paulius
Published: December 2021

The control of laser-induced microcracks in the volume of transparent materials is essential for scribing processes. In this paper, we investigate the effect of various amplitude and single-level phase masks on both transverse and axial intensity distribution of the conventional axicon-generated Bessel beams. Furthermore, we demonstrate the volumetric crack control induced by an asymmetrical central core with an appropriately selected intensity level to avoid the influence of peripheral intensity maxima. Proper alignment of cracks and intra-distance between the modifications results in the reduced separation stress of the scribed samples. Furthermore, the additional amplitude modulation of the incident Gaussian beam is introduced to flatten the axial intensity distribution of the axicon-generated Bessel beam.
Dynamic surface-enhanced Raman spectroscopy of DNA oligomer with a single hotspot from a gold nanoparticle dimer
Authors: Sugano Koji , Maruoka Katsunari , Ikegami Kohei , Uesugi Akio , Isono Yoshitada
Published: December 2021

Various nanostructures for single-molecule surface-enhanced Raman spectroscopy (SERS) have been fabricated through a random aggregation process using nanoparticles that can stochastically generate multiple hotspots in the laser spot. This leads to multiple molecule detection. In this study, a single gold nanoparticle (AuNP) dimer with a single hotspot was fabricated in a laser spot controlling the position and orientation on a silicon substrate using a nanotrench-guided self-assembly. The Raman peaks of deoxyribonucleic acid (DNA) were dynamically observed, indicating a single DNA oligomer detection composed of adenine, guanine, cytosine, phosphate, and deoxyribose.
Kilowatt random Raman fiber laser with full-open cavity
Authors: Zhang Hanwei , Wu Jinming , Wan Yingchao , Wang Peng , Yang Baolai , Xi Xiaoming , Wang Xiaolin , Zhou Pu
Published: December 2021

Random Raman fiber laser (RRFL) has been widely studied in high-power laser generation due to its special lasing characteristics. However, all previous high-power results are based on the half-open cavity. In this letter, we demonstrate an applicable high-power RRFL with the simplest structure, that is, a full-open cavity. The lasing dynamic and output characteristics are theoretically and experimentally studied. Laser source with multi-longitudinal modes can result in the random laser output from one side even in the full-open cavity. The ratio of the backward output power is mainly determined by the reflectivity of fiber ends. The experimental results show that such a simple structure can easily generate kilowatts of random laser power and is a promising setup to achieve higher output power, which is also an important platform to study the laser dynamic in high-power full-open cavity without any point-action or regular distributed reflectors.
Large dynamic range and wideband mid-infrared upconversion detection with BaGa4Se7 crystal
Authors: Liu Pengxiang , Guo Liyuan , Qi Feng , Li Weifan , Li Wei , Fu Qiaoqiao , Yao Jiyong , Xia Mingjun , Liu Zhaoyang , Wang Yelong
Published: December 2021

Direct detection of
mid-infrared (MIR) at room temperature commonly suffers from the high
background noise and the lack of ideal sensor material. An indirect
upconversion method based on nonlinear optics bridges the desired MIR
region to the well-developed near-infrared devices. In this paper, we
report an experimental study of 3–8 µm MIR upconversion detection with
a 1 µm laser-pumped

B
a
G

a

4

S

e

7

crystal. This detection scheme is
integrated with an optical parametric oscillator and an optical
receiver to form a coherent source and detection system that offers
high temporal (nanosecond time scale) and spectral resolution (

≤

3

c

m

−
1

). The wide response band (

>

1.4

octave) and large dynamic range (11.5
orders) of this detection scheme benefits from the superior optical
properties of this non-oxide crystal, and a minimum detectable energy
of 1.02 fJ/pulse is observed with an InGaAs p-i-n photodiode. The
upconversion technique outperforms commercial HgCdTe detectors in
terms of both sensitivity (2–4.5 orders better) and wavelength
response flatness. The aforementioned characteristics of this
integrated MIR source and detection system make it of significant
interest for applications in high-resolution gas analysis and spectral
imaging.
Systematic analysis of noise reduction properties of coupled and isolated feed-forward loops
Authors: Chakravarty Suchana , Csikász-Nagy Attila
Published: December 2021

Cells can maintain their homeostasis in a noisy environment since their signaling pathways can filter out noise somehow. Several network motifs have been proposed for biological noise filtering and, among these, feed-forward loops have received special attention. Specific feed-forward loops show noise reducing capabilities, but we notice that this feature comes together with a reduced signal transducing performance. In posttranslational signaling pathways feed-forward loops do not function in isolation, rather they are coupled with other motifs to serve a more complex function. Feed-forward loops are often coupled to other feed-forward loops, which could affect their noise-reducing capabilities. Here we systematically study all feed-forward loop motifs and all their pairwise coupled systems with activation-inactivation kinetics to identify which networks are capable of good noise reduction, while keeping their signal transducing performance. Our analysis shows that coupled feed-forward loops can provide better noise reduction and, at the same time, can increase the signal transduction of the system. The coupling of two coherent 1 or one coherent 1 and one incoherent 4 feed-forward loops can give the best performance in both of these measures.
Nerve recovery from treatment with a vascularized nerve graft compared to an autologous non-vascularized nerve graft in animal models: A systematic review and meta-analysis
Authors: Broeren Berend O. , Duraku Liron S. , Hundepool Caroline A. , Walbeehm Erik T. , Zuidam J. Michiel , Hooijmans Carlijn R. , De Jong Tim
Published: December 2021

Background

Treatment of nerve injuries proves to be a worldwide clinical challenge. Vascularized nerve grafts are suggested to be a promising alternative for bridging a nerve gap to the current gold standard, an autologous non-vascularized nerve graft. However, there is no adequate clinical evidence for the beneficial effect of vascularized nerve grafts and they are still disputed in clinical practice.

Objective

To systematically review whether vascularized nerve grafts give a superior nerve recovery compared to non-vascularized nerve autografts regarding histological and electrophysiological outcomes in animal models.

Material and methods

PubMed and Embase were systematically searched. The inclusion criteria were as follows: 1) the study was an original full paper which presented unique data; 2) a clear comparison between a vascularized and a non-vascularized autologous nerve transfer was made; 3) the population study were animals of all genders and ages. A standardized mean difference and 95% confidence intervals for each comparison was calculated to estimate the overall effect. Subgroup analyses were conducted on graft length, species and time frames.

Results

Fourteen articles were included in this review and all were included in the meta-analyses. A vascularized nerve graft resulted in a significantly larger diameter, higher nerve conduction velocity and axonal count compared to an autologous non-vascularized nerve graft. However, during sensitivity analysis the effect on axonal count disappeared. No significant difference was observed in muscle weight.

Conclusion

Treating a nerve gap with a vascularized graft results in superior nerve recovery compared to non-vascularized nerve autografts in terms of axon count, diameter and nerve conduction velocity. No difference in muscle weight was seen. However, this conclusion needs to be taken with some caution due to the inherent limitations of this meta-analysis. We recommend future studies to be performed under conditions more closely resembling human circumstances and to use long nerve defects.
Investigating the risk factors for seroprevalence and the correlation between CD4+ T-cell count and humoral antibody responses to Toxoplasma gondii infection amongst HIV patients in the Bamenda Health District, Cameroon
Authors: Fang Eugene Enah , Nyasa Raymond Babila , Ndi Emmanuel Menang , Zofou Denis , Kwenti Tebit Emmanuel , Lepezeu Edith Pafoule , Titanji Vincent P. K. , N. Ndip Roland
Published: December 2021

Background

Toxoplasmosis is caused by an obligate intracellular tissue protozoan parasite, Toxoplasma gondii that infect humans and other warm-blooded animals. Transmission to humans is by eating raw or inadequately cooked infected meat or through ingestion of oocysts that cats have passed in faeces. Studies have shown life-threatening and substantial neurologic damage in immunocompromised patients; however, 80% of humans remain asymptomatic. The aim of this study was to determine the seroprevalence of Toxoplasma gondii infection in HIV positive patients and the risk factors associated with the infection, and to investigate the correlation between CD4+ T-cell count and toxoplasma specific antibodies as possible predictors of each other amongst HIV patients in the Bamenda Health District of the North West Region of Cameroon.

Methods

A cross-sectional study was conducted, in which 325 HIV patients were recruited for administration of questionnaire, serological diagnosis of T. gondii and measurement of CD4+ T-cell count. Bivariate and multivariate logistic regression was used to identify risk factors associated with T. gondii infection while the linear regression was used to investigate the relationship between CD4+ T-cell count and antibody levels against T. gondii.

Results

The findings showed that, majority (45.8%) of HIV patients suffered from chronic (IgG antibody) infection, and 6.5% from acute (IgM and IgM/IgG antibody) toxoplasma infection. The overall sero-prevalence of T. gondii infection amongst HIV patients was 50.5%. On the whole, 43 men (45.7%) and 127 women (55%) presented with anti- T. gondii antibodies; however, there was no significant difference amongst males and females who were positive to T. gondii infection (p = 0.131). Marital status (p = 0.0003), contact with garden soil (p = 0.0062), and garden ownership (p = 0.009), were factors that showed significant association with T. gondii infection. There was no significant difference (p = 0.909) between the mean CD4+ T-cell count of HIV patients negative for toxoplasma infection (502.7 cells/mL), chronically infected with T. gondii (517.7 cells/mL) and acutely infected with T. gondii (513.1 cells/mL). CD4+ T-cell count was neither a predictor of IgM antibody titer (r = 0.193, p = 0.401), nor IgG antibody titer (r = 0.149, p = 0.519) amongst HIV patients acutely infected with T. gondii.

Conclusion

The findings from this study underscore the need to implement preventive and control measures to fight against T. gondii infection amongst HIV patients in the Bamenda Health District.
Education for non-citizen children in Malaysia during the COVID-19 pandemic: A qualitative study
Authors: Loganathan Tharani , Chan Zhie X. , Hassan Fikri , Kunpeuk Watinee , Suphanchaimat Rapeepong , Yi Huso , Majid Hazreen Abdul
Published: December 2021

The COVID-19 pandemic disrupted schooling for children worldwide. Most vulnerable are non-citizen children without access to public education. This study aims to explore challenges faced in achieving education access for children of refugee and asylum-seekers, migrant workers, stateless and undocumented persons in Malaysia during the pandemic. In-depth interviews of 33 stakeholders were conducted from June 2020 to March 2021. Data were thematically analysed. Our findings suggest that lockdowns disproportionately impacted non-citizen households as employment, food and housing insecurity were compounded by xenophobia, exacerbating pre-existing inequities. School closures disrupted school meals and deprived children of social interaction needed for mental wellbeing. Many non-citizen children were unable to participate in online learning due to the scarcity of digital devices, and poor internet connectivity, parental support, and home learning environments. Teachers were forced to adapt to online learning and adopt alternative arrangements to ensure continuity of learning and prevent school dropouts. The lack of government oversight over learning centres meant that measures taken were not uniform. The COVID-19 pandemic presents an opportunity for the design of more inclusive national educational policies, by recognising and supporting informal learning centres, to ensure that no child is left behind.
Can the dual-rating regulation improve the rating quality of Chinese corporate bonds?
Authors: Zhou Xiangyun
Published: December 2021

We developed a dual-reputational rating shopping model to introduce public and institutional reputations. Investor’s and regulator’s penalty rates are described as public and institutional reputations, respectively. We achieved the available conditions of single-rating and dual-rating regulations to prevent rating inflation in this model. To examine the regulatory effects of different types of regulations on Chinese corporate bond ratings, we utilize panel ordered logit models. Theoretical analysis and empirical tests show that, when the reputation effect is low, the single-rating regulation is better at improving rating quality, and when the reputation effect is high, the dual-rating regulation induces rating agencies to provide more accurate ratings. Compared to the regulatory effects of the single-rating and the multi-rating regulations, the dual-rating regulation most effectively improves the rating quality of corporate bonds and prevents rating inflation.
Epidemiology of clubfoot in Sweden from 2016 to 2019: A national register study
Authors: Esbjörnsson Anna-Clara , Johansson Arne , Andriesse Hanneke , Wallander Henrik
Published: December 2021

Background

This study aimed to estimate the birth prevalence of children born with isolated or non-isolated clubfoot in Sweden using a national clubfoot register. Secondarily we aimed to describe the clubfoot population with respect to sex, laterality, severity of deformity, comorbidity and geographic location.

Methods

A national register, the Swedish Pediatric Orthopedic Quality register, was used to extract data on newborn children with clubfoot. To calculate the birth prevalence of children with isolated or non-isolated clubfoot between 1st of January 2016 and 31st of December 2019, we used official reports of the total number of Swedish live births from the Swedish Board of Statistics. The Pirani score and predefined signs of atypical clubfoot were used to classify clubfoot severity at birth.

Results

In total 612 children with clubfoot were identified. Of these, 564 were children with isolated clubfoot, generating a birth prevalence of 1.24/1000 live births (95% confidence interval 1.15–1.35). About 8% were children with non-isolated clubfoot, increasing the birth prevalence to 1.35/1000 live births (95% confidence interval 1.25–1.46). Of the children with isolated clubfoot, 74% were boys and 47% had bilateral involvement. The children with non-isolated clubfoot had more severe foot deformities at birth and a greater proportion of clubfeet with atypical signs compared with children with isolated clubfoot.

Conclusion

We have established the birth prevalence of children born with isolated or non-isolated clubfoot in Sweden based on data from a national register. Moreover, we have estimated the number of children born with atypical clubfeet in instances of both isolated and non-isolated clubfoot. These numbers may serve as a baseline for expected birth prevalence when planning clubfoot treatment and when evaluating time trends of children born with clubfoot.
Influence of polyvascular disease on clinical outcome in patients undergoing transcatheter aortic valve implantation via transfemoral access
Authors: Yamawaki Masahiro , Honda Yosuke , Makino Kenji , Nakano Takahide , Iida Yasunori , Yashima Fumiaki , Ueno Hiroshi , Mizutani Kazuki , Tabata Minoru , Tada Norio , Takagi Kensuke , Yamanaka Futoshi , Naganuma Toru , Watanabe Yusuke , Yamamoto Masanori , Shirai Shinichi , Hayashida Kentaro ,   on behalf of OCEAN-TAVI registry
Published: December 2021

Background

The influence of polyvascular disease (PVD) on the short- and long-term clinical outcomes of patients undergoing transcatheter aortic valve implantation via trans-femoral access (TF-TAVI) has not been fully elucidated.

Methods

A total of 2167 patients from the Optimized CathEter vAlvular iNtervention-TAVI (OCEAN-TAVI) registry who underwent TF-TAVI was studied. PVD was defined as the presence of at least two of the following vascular bed (VB) diseases: concomitant coronary artery disease (CAD), cerebrovascular disease (CVD), and peripheral artery disease (PAD).

Results

Patients with PVD (288 patients, 13.3%) had a higher incidence of in-hospital complications, such as AKI (16.3% vs. 7.0%, p<0.01) and disabling stroke (3.5% vs. 1.2%, p<0.01) than patients without PVD. These complications caused higher rates of procedural mortality (4.5% vs. 2.0%, p<0.01). PVD increased the risk of the 2-year rate of cardiovascular death (adjusted hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.04–2.50; p<0.05); however, non-cardiovascular death, myocardial infarction, or ischemic stroke was not associated with PVD. Worsening heart failure (4.6% vs. 1.1%, p<0.01) was the main cause of cardiovascular death among patients with PVD. In a sub-analysis, compared with patients with AS alone, those with 2 VB diseases (CAD+PAD; adjusted HR, 1.93; 95% CI, 1.06–3.53; p<0.05) and 3 VB diseases (CAD+CVD+PAD; adjusted HR, 2.61; 95% CI, 1.21–5.62; p<0.05) had a higher risk of 2-year cardiovascular death.

Conclusions

The increased prevalence of concomitant atherosclerotic VB diseases before TF-TAVI may increase the rates of in-hospital complications and 2-year cardiovascular death. Given the higher rate of mortality in patients with PVD undergoing TF-TAVI, future studies focusing on medical therapy are needed to reduce long-term cardiovascular events in this high-risk subset.
3D fluorescence microscopy data synthesis for segmentation and benchmarking
Authors: Eschweiler Dennis , Rethwisch Malte , Jarchow Mareike , Koppers Simon , Stegmaier Johannes
Published: December 2021

Automated image processing approaches are indispensable for many biomedical experiments and help to cope with the increasing amount of microscopy image data in a fast and reproducible way. Especially state-of-the-art deep learning-based approaches most often require large amounts of annotated training data to produce accurate and generalist outputs, but they are often compromised by the general lack of those annotated data sets. In this work, we propose how conditional generative adversarial networks can be utilized to generate realistic image data for 3D fluorescence microscopy from annotation masks of 3D cellular structures. In combination with mask simulation approaches, we demonstrate the generation of fully-annotated 3D microscopy data sets that we make publicly available for training or benchmarking. An additional positional conditioning of the cellular structures enables the reconstruction of position-dependent intensity characteristics and allows to generate image data of different quality levels. A patch-wise working principle and a subsequent full-size reassemble strategy is used to generate image data of arbitrary size and different organisms. We present this as a proof-of-concept for the automated generation of fully-annotated training data sets requiring only a minimum of manual interaction to alleviate the need of manual annotations.
Effect of HIV status and retinol on immunogenicity to oral cholera vaccine in adult population living in an endemic area of Lukanga Swamps, Zambia
Authors: Luchen Charlie Chaluma , Mwaba John , Ng’ombe Harriet , Alabi Peter Ibukun Oluwa , Simuyandi Michelo , Chilyabanyama Obvious N. , Hatyoka Luiza Miyanda , Mubanga Cynthia , Bosomprah Samuel , Chilengi Roma , Chisenga Cleopatra Caroline
Published: December 2021

Background

We set out to assess the impact of human immunodeficiency virus (HIV) and micronutrient deficiency as indicated by serum retinol levels on the immune responses to Oral Cholera Vaccine (Shanchol™) in a cohort of participants in Lukanga Swamps, Zambia. Cholera remains endemic in Zambia with vaccines being the only effective preventive measures. However, the effect of these vaccines on populations living with HIV has not been widely documented.

Methods

HIV testing and confirmation was done using the Alere Determine™ HIV-1/2 and Uni-Gold™ kits while vibriocidal antibody assay was applied for vaccine immunogenicity. Serum retinol analysis was assessed by Shimadzu Prominence HCT-2010 High Performance Liquid Chromatography (HPLC). The primary outcome was log transformed geometric mean titre.

Results

From 47 participants screened for HIV, 51% (24) tested positive. There was a statistically significant reduction in Ogawa geometric mean ratio (GMR) by 67% (GMR = 0.33; 95% CI: -0.15, 0.76; p-value = 0.009) attributable to HIV positivity with a non-significant reduction in Inaba GMR by about 50% due to HIV positivity. When doubling of retinol levels modelled, GMR reduction against Ogawa were non-significant but that against Inaba resulted in a significant reduction in geometric mean titer (GMT) (GMT-0.33, C.I 0.16–0.66, p-value 0.002). At 1000copies/ml viral load cut off and 350 cells/μl CD4 counts, Ogawa GMT was two times higher 11.16 (95%CI: 8.20–15.19) versus 6.06 (95%CI: 4.04–9.10) in low viremia participants, and three times higher in above threshold CD4 count participants; 24.81 (95%CI: 18.94–32.50) versus 7.07 (95%CI: 5.22–9.58).

Conclusion

Our results show that while Shanchol™ is immunogenic in both HIV+/- individuals, HIV + participants responded poorly. Viral load and CD4 count affected vaccine immunogenicity. More research is required for detailed understanding of this in order to appropriately inform policy and practice.
Determinism of microbial community assembly by drastic environmental change
Authors: Nishida Akifumi , Nakagawa Mayuko , Yamamura Masayuki
Published: December 2021

Microbial community assembly is shaped by deterministic and stochastic processes, but the relationship between these processes and the environment is not understood. Here we describe a rule for the determinism and stochasticity of microbial community assembly affected by the environment using in silico, in situ, and ex situ experiments. The in silico experiment with a simple mathematical model showed that the existence of essential symbiotic microorganisms caused stochastic microbial community assembly, unless the community was exposed to a non-adapted nutritional concentration. Then, a deterministic assembly occurred due to the low number of microorganisms adapted to the environment. In the in situ experiment in the middle of a river, the microbial community composition was relatively deterministic after the drastic environmental change caused by the treated wastewater contamination, as analyzed by 16S rRNA gene sequencing. Furthermore, by culturing microbial communities collected from the upstream natural area and downstream urban area of the river in test tubes with varying carbon source concentrations, the upstream community assembly became deterministic with high carbon concentrations while the downstream community assembly became deterministic with low carbon concentrations. These results suggest that large environmental changes, which are different from the original environment, result in a deterministic microbial community assembly.
Vague data analysis using neutrosophic Jarque–Bera test
Authors: Aslam Muhammad , Sherwani Rehan Ahmad Khan , Saleem Muhammad
Published: December 2021

In decision-making problems, the researchers’ application of parametric tests is the first choice due to their wide applicability, reliability, and validity. The common parametric tests require the validation of the normality assumption even for large sample sizes in some cases. Jarque-Bera test is among one of the methods available in the literature used to serve the purpose. One of the Jarque-Bera test restrictions is the computational limitations available only for the data in exact form. The operational procedure of the test is helpless for the interval-valued data. The interval-valued data generally occurs in situations under fuzzy logic or indeterminate state of the outcome variable and is often called neutrosophic form. The present research modifies the existing statistic of the Jarque-Bera test for the interval-valued data. The modified design and operational procedure of the newly proposed Jarque-Bera test will be useful to assess the normality of a data set under the neutrosophic environment. The proposed neutrosophic Jarque-Bera test is applied and compared with its existing form with the help of a numerical example of real gold mines data generated under the fuzzy environment. The study’s findings suggested that the proposed test is effective, informative, and suitable to be applied in indeterminacy compared to the existing Jarque–Bera test.
Magnitude and associated factors of antenatal depression among mothers attending antenatal care in Arba Minch town, Ethiopia, 2018
Authors: Beketie Eskedar Demissie , Kahsay HaileMariam Berhe , Nigussie Fiseha Girma , Tafese Wubishet Tesfaye
Published: December 2021

Background

Depression is a common mental disorder. The burden of antenatal depression is higher in developing countries which is 20% as compared to developed ones 10% to 15%. In Ethiopia around one-fifth of pregnant mothers are depressed. Despite the severity of the problem, only a few studies have been done in Ethiopia, and there is no study done in Arba Minch on the problem.

Objective

To assess the magnitude and associated factors of antenatal depressive symptoms among pregnant women attending Public Health facilities in Arba Minch town Southern Nations and Nationalities Peoples Region, Ethiopia 2018.

Methods

Health Institution based, cross-sectional study design was used to assess the magnitude and associated factors of antenatal depression among 323 pregnant mothers who came for antenatal care follow-up in all public health facilities in Arba Minch town. The systematic random sampling technique was applied. Interviewer administered, pretested structured Questionnaire containing Edinburgh postpartum depression scale was utilized. EPI INFO was used to enter data and then the data were analyzed by logistic regression using SPSS. Variables with P-value less than 0.2 in the bivariate logistic regression were inserted in for multivariable analysis to see their independent effect and those with P-value less than 0.05 were used to determine the significant association between dependent and independent variables.

Result

The magnitude of antenatal depression was 35.4%. Variables that were significantly associated with antenatal depression on multivariate analysis were anxiety (AOR = 5.49, 95%CI: 2.56, 11.77), un-planned pregnancy (AOR = 2.71, 95%CI: 1.21, 6.07), and Primigravida (AOR = 2.96, 95%CI: 1.28, 6.8). Similarly, uneducated mothers and those who attend only elementary school had AOR 4.92, 95% CI 1.36,17.73 and AOR 4.04955CI 1.23, 13.39 respectively.

Conclusion

The magnitude of antenatal depression, intimate partner violence, and threatening life event in Arba Minch town was high. Anxiety, unplanned pregnancy, educational status, and Primigravida were significantly associated factors with depression. There should be a mechanism for routine screening and management of antenatal depression and intimate partner violence during antenatal care follow-up.