bluuebunny/crossref_metadata_2025 huggingface dataset:
Monolithic integration of laser onto multilayer silicon nitride photonic integrated circuits with high efficiency at telecom wavelength
Authors: Yang Yisu , Zhao Hao , Ren Xiaomin , Huang Yongqing
Published: August 2021

We propose a multilayer silicon nitride (SiN) -on-silicon photonic integrated circuit (PIC) platform with a monolithic laser at the C-band. A tapered edge coupler and a meta-structure-based interlayer directional coupler in the platform were designed to realize low-loss broadband laser-to-chip 3D coupling with small footprint. The coupling length of the interlayer directional coupler and the gap between different SiN layers were optimized as 12.7 µm and 1.4 µm. We measured the 1-dB-drop optical operation bandwidth of greater than 76 nm and the coupling loss of 6.1 ± 0.1 dB at 1550 nm for the interlayer directional coupler. The hybrid integration was demonstrated as a proof of concept for monolithic integration of light sources. The butt-coupling loss of 3.7 ± 0.1 dB between an on-chip DFB laser and a SiN edge coupler at 1549.48 nm was achieved. This approach opens the possibility of employing monolithic laser in the silicon photonics platform.
Single-shot fringe pattern phase retrieval using improved period-guided bidimensional empirical mode decomposition and Hilbert transform
Authors: Gocłowski Paweł , Cywińska Maria , Ahmad Azeem , Ahluwalia Balpreet , Trusiak Maciej
Published: August 2021

Fringe pattern analysis is the central aspect of numerous optical measurement methods, e.g., interferometry, fringe projection, digital holography, quantitative phase microscopy. Experimental fringe patterns always contain significant features originating from fluctuating environment, optical system and illumination quality, and the sample itself that severely affect analysis outcome. Before the stage of phase retrieval (information decoding) interferogram needs proper filtering, which minimizes the impact of mentioned issues. In this paper we propose fully automatic and adaptive fringe pattern pre-processing technique - improved period guided bidimensional empirical mode decomposition algorithm (iPGBEMD). It is based on our previous work about PGBEMD which eliminated the mode-mixing phenomenon and made the empirical mode decomposition fully adaptive. In present work we overcame key problems of original PGBEMD – we have considerably increased algorithm’s application range and shortened computation time several-fold. We proposed three solutions to the problem of erroneous decomposition for very low fringe amplitude images, which limited original PGBEMD significantly and we have chosen the best one among them after comprehensive analysis. Several acceleration methods were also proposed and merged to ensure the best results. We combined our improved pre-processing algorithm with the Hilbert Spiral Transform to receive complete, consistent, and versatile fringe pattern analysis path. Quality and effectiveness evaluation, in comparison with selected reference methods, is provided using numerical simulations and experimental fringe data.
Performance analysis of an all-dielectric planar Mikaelian lens antenna for 1-D beam-steering application
Authors: Shao Wenyi , Chen Qiang
Published: August 2021

This paper investigates the performance of an all-dielectric planar Mikaelian lens based on ray transfer matrices and full-wave analysis for 1-D beam-steering application. This new lens concept has its intrinsic flat shape characteristic allowing for a simple low-cost planar feed technology. To verify the design concept, a lens prototype excited by five rectangular microstrip patch antennas with perforated structure (21×24 holes) is fabricated using stereolithography (SLA) 3-D printing. The simulated and measured results of the proposed lens prototype, operating at 10 GHz, shows that the switched-beam coverage over a certain range of beam-steering angles can be obtained. The intrinsic phase error of lens resulting from comatic aberration exhibits obvious increase as the off-axis angle of beam increases, which leads to further deterioration of the corresponding radiated beam. The beam-steering capabilities from −20° to +20° with around 13.2 dBi of realized gain and side-lobe level (less than −11.5dB), and up to potential steering angles (±30°) with around 10 dBi of realized gain can be steadily achieved. Moreover, the realized gain, efficiency and side-lobe level can be further improved to get better radiation performances by using other materials with lower loss tangent. Due to its intrinsic flat shape characteristic, this lens concept could be a potential alternative to develop a low-cost, low-profile and easy-to-fabricate beam-switching array antenna for microwave communication applications.
Stacked GaN/AlN last quantum barrier for high-efficiency InGaN-based green light-emitting diodes
Authors: Tao Guoyi , Zhao Xiaoyu , Zhou Shengjun
Published: August 2021

Realization of efficient InGaN-based green light-emitting diodes (LEDs) is highly desirable in solid-state lighting industry. Here, we propose a stacked last quantum barrier (SLQB) GaN/AlN layer for green (

∼

550

n
m

) LEDs grown on patterned sapphire substrate to improve the device performance. A green LED with a SLQB achieves a light output power (LOP) of 13 mW at 15 mA, which is 35% higher than that of LEDs with a conventional last quantum barrier (CLQB) GaN layer. In addition, the forward voltage of the green LED with the SLQB is reduced by 0.16 V compared with green LEDs with the CLQB. Simulation results demonstrate that the AlN layer in the SLQB increases the effective barrier height for electrons and alleviates the electron leakage effect. It also enables an intraband tunneling process for holes to inject into the active region, promoting the hole injection efficiency. As a result, we successfully obtain InGaN-based green LEDs with remarkably improved carrier injection efficiency by adopting the SLQB structure.
Laser paintbrush as a tool for modern art: publisher’s note
Authors: Veiko Vadim P. , Andreeva Yaroslava , Van Cuong Luong , Lutoshina Daria , Polvakov Dmitrv , Sinev Dmitrv , Mikhailovskii Vladimir , Kolobov Yurv R. , Odintsova Galina
Published: August 2021

This publisher’s note reports a correction to Eq. (1) of
Optica
8, 577–585 (2021)OPTIC82334-253610.1364/OPTICA.420074.
Beam steering and forming in compact electrowetting prism array with separate electrode control
Authors: Lee Jooho , Lee Junsik , Won Yong Hyub
Published: August 2021

Large aperture beam steering in a transmissive and compact device has been an important design objective for various technologies including LIDAR and 3D displays. We propose a new aperture variable beam steering method using an electrowetting prism array. By individually controlling the voltage of electrode, 3-dimensional beam steering is possible because it can manipulate beam steering and forming simultaneously. The total aperture of the prism array can be varied depending on the number of arrays. The operating speed was 25ms and the steering range was ±9.5° in the transverse and longitudinal directions, and ±13.2° in the diagonal direction. The range of optical power was −47.6D to 47.6D. Measurement of optical properties such as the RMS wavefront error as the sum of all aberrations of the prism and the radius of curvature, which is the flatness of the interface, and a demonstration of a 3-dimensional beam steering is also presented.
Resonance and topological singularity near and beyond zero frequency for waves: model, theory, and effects
Authors: Xiong Langlang , Zhang Yu , Jiang Xunya
Published: August 2021

Research interest in resonance and topology for systems at near-zero frequency, whose wavelength could be 2 orders larger than the scale of resonators is very rare, since the trivial effective-medium theory is generally thought to be correct in this regime. Also, the complex frequency regime is generally thought to be irrelevant to the topological properties of Hermitian systems. In this work, we find the general conditions to realize near-zero frequency resonance for a resonator and theoretically propose two kinds of realizations of such resonators, which are confirmed by numerical methods. The photonic crystals with such a resonator as the unit cell present rich topological characteristics at the near-zero frequency regime. The topological singularity that corresponds to the resonant frequency of the unit cell can be pushed to zero frequency at the bottom of the first band by tuning a certain parameter to a critical value. Surprisingly, we find that, when the parameter is tuned over the critical value, the singularity has disappeared in the first band and is pushed into the imaginary frequency regime, but now the topology of the first band and gap is still nontrivial, which is demonstrated by the existence of the topological edge state in the first gap, the negative sign of imaginary part of the surface impedance, and the symmetry property of Wannier functions. So, we are forced to accept that the singularity in the imaginary frequency regime can influence the topology in the real frequency regime. So, for the first time, to the best of our knowledge, we find that the singularity in the pure imaginary regime can still cause the observable topological effects on the real frequency regime, even for the Hermitian systems. Now, zero frequency acts as a novel exceptional point for Hermitian systems and the topology of the first band and first gap could be quite different from other bands and gaps, since they are intrinsically connected with zero frequency. Other new phenomena are also observed when the singularity is at the near-zero frequency regimes (real or imaginary), e.g.,  the cubic relationship between reflection coefficient and the frequency, the robust wide-bandwidth high transmission at very low frequency, etc. Besides the theoretical importance, some basic applications, such as the robust deep subwavelength wide bandwidth high-transmission layered structures, the subwavelength wide bandwidth absorbers, and the cavity from the topological subwavelength edge state are proposed, which can inspire new designs in many areas of optics, microwaves, and acoustics. This work opens a new window for rich topological physics and revolutionary device designs at the near and beyond zero-frequency regimes.
Dye-sensitized Er3+-doped CaF2 nanoparticles for enhanced near-infrared emission at 1.5  μm
Authors: Liu Jing , Artizzu Flavia , Zeng Min , Pilia Luca , Geiregat Pieter , Van Deun Rik
Published: August 2021

Lanthanide (Ln)-doped nanoparticles have shown potential for applications in various fields. However, the weak and narrow absorption bands of the Ln ions (

Ln

3
+

), hamper efficient optical pumping and severely limit the emission intensity. Dye sensitization is a promising way to boost the near-infrared (NIR) emission of

Er

3
+

, hence promoting possible application in optical amplification at 1.5 μm, a region that is much sought after for telecommunication technology. Herein, we introduce the fluorescein isothiocyanate (FITC) organic dye with large absorption cross section as energy donor of small-sized (

∼
3.6
  
nm

)

Er

3
+

-doped

CaF

2

nanoparticles. FITC molecules on the surface of

CaF

2

work as antennas to efficiently absorb light, and provide the indirect sensitization of

Er

3
+

boosting its emission. In this paper, we employ photoluminescence and transient absorption spectroscopy, as well as density functional theory calculations, to provide an in-depth investigation of the

FITC
→

Er

3
+

energy transfer process. We show that an energy transfer efficiency of over 89% is achieved in

CaF

2

:

Er

3
+

@
FITC

nanoparticles resulting in a 28 times enhancement of the

Er

3
+

NIR emission with respect to bare

CaF

2

:

Er

3
+

. Through the multidisciplinary approach used in our work, we are able to show that the reason for such high sensitization efficiency stems from the suitable size and geometry of the FITC dye with a localized transition dipole moment at a short distance from the surface of the nanoparticle.
Proposal and demonstration of a controllable Q factor in directly coupled microring resonators for optical buffering applications
Authors: Zhang Ying , Liu Qiang , Mei Chenyang , Zeng Desheng , Huang Qingzhong , Zhang Xinliang
Published: August 2021

Optical resonators with controllable

Q

factors are key components in many areas of optical physics and engineering. We propose and investigate a

Q

-factor controllable system composed of two directly coupled microring resonators, one of which is tunable and coupled to dual waveguides. By shifting the resonance of the controllable microring, the

Q

factor of the system as well as the other microring changes significantly. We have demonstrated wide-range controllable

Q

factors based on this structure in silicon-on-insulator, for example. The influences of spectral detuning and coupling strength between two resonators on the variation of

Q

factors are studied in detail experimentally. Then, we explore its applications in optical buffering. Tunable fast-to-slow/slow-to-fast light has been carried out by switching the system between the high-

Q

state and low-

Q

state. Moreover, optical pulse capture and release are also achievable using this structure with dynamic tuning, and the photon storage properties are investigated. The proposed

Q

-factor tunable system is simple, flexible, and realizable in various integrated photonic platforms, allowing for potential applications in on-chip optical communications and quantum information processing.
Controlling the collective radiative decay of molecular ions in strong laser fields
Authors: Xie Hongqiang , Lei Hongbin , Li Guihua , Yao Jinping , Zhang Qian , Wang Xiaowei , Zhao Jing , Chen Zhiming , Cheng Ya , Zhao Zengxiu
Published: August 2021

Molecular ions, produced via ultrafast ionization, can be quantum emitters with the aid of resonant electronic couplings, which makes them the ideal candidates to study strong-field quantum optics. In this work, we experimentally and numerically investigate the necessary condition for observing a collective emission arising from macroscopic quantum polarization in a population-inverted

N
2
+

gain system, uncovering how the individual ionic emitters proceed into a coherent collection within hundreds of femtoseconds. Our results show that for a relatively high-gain case, the collective emission behaviors can be readily initiated for all the employed triggering pulse area. However, for a low-gain case, the superradiant amplification is quenched since the building time of macroscopic interionic quantum coherence exceeds the dipole dephasing time, in which situation the seed amplification and free induction decay play an essential role. These findings not only clarify the contentious key issue regarding to the amplification mechanism of

N
2
+

lasing but also show the unique characteristics of ultrashort laser-induced amplification in a molecular ion system where both the microscopic and macroscopic quantum coherence might be present.
Single-mode helical Bragg grating waveguide created in a multimode coreless fiber by femtosecond laser direct writing
Authors: He Jun , He Jia , Xu Xizhen , Du Bin , Xu Baijie , Liao Changrui , Bai Zhiyong , Wang Yiping
Published: August 2021

We demonstrate the fabrication of single-mode helical Bragg grating waveguides (HBGWs) in a multimode coreless fiber by using a femtosecond laser direct writing technique. This approach provides a single-step method for creating Bragg grating waveguides. Specifically, the unique helical structure in such an HBGW serves as a depressed cladding waveguide and also generates strong Bragg resonance due to its periodicity. Effects of pulse energy, helical diameter, and helical pitch used for fabricating HBGWs were studied, and a single-mode HBGW with a narrow bandwidth of 0.43 nm and a Bragg wavelength of 1546.50 nm was achieved by using appropriate parameters, including a diameter of 10 μm and a helical pitch of 1.07 μm. The measured cross-sectional refractive index profile indicates that a depressed cladding waveguide has been created in this single-mode HBGW. Moreover, five single-mode HBGWs with various Bragg wavelengths were successfully fabricated by controlling the helical pitch, and this technique could be used for achieving a wavelength-division-multiplexed HBGW array. Then, the temperature and strain responses of the fabricated single-mode HBGW were tested, exhibiting a temperature sensitivity of 11.65 pm/°C and a strain sensitivity of 1.29 pm/με, respectively. In addition, the thermal stability of the single-mode HBGW was also studied by annealing at a high temperature of 700°C for 15 h. The degeneration of the single-mode waveguide into a multimode waveguide was observed during the isothermal annealing process, and the peak reflection and the Bragg wavelength of the fundamental mode exhibited a decrease of

∼
7
  
dB

and a “blue” shift of 0.36 nm. Hence, such a femtosecond laser directly written single-mode HBGW could be used in many applications, such as sapphire fiber sensors, photonic integrated circuits, and monolithic waveguide lasers.
Farmer perceptions and willingness to pay for novel livestock pest control technologies: A case of tsetse repellent collar in Kwale County in Kenya
Authors: Muriithi Beatrice W. , Gathogo Nancy G. , Diiro Gracious M. , Kidoido Michael M. , Okal Michael Nyangánga , Masiga Daniel K.
Published: August 2021

Tsetse-transmitted Animal African Trypanosomosis (AAT) is one of the most important constraints to livestock development in Africa. Use of trypanocides has been the most widespread approach for the management of AAT, despite the associated drug resistance and health concerns associated with drug metabolites in animal products. Alternative control measures that target tsetse fly vectors of AAT, though effective, have been hard to sustain in part because these are public goods applied area-wide. The International Centre of Insect Physiology and Ecology (icipe)and partners have developed and implemented a novel tsetse repellent collar (TRC) applied on animals to limit contact of tsetse flies and livestock, thereby reducing AAT transmission. The TRC has now advanced to commercialization. A household-level survey involving 632 cattle keeping households, was conducted in Shimba Hills region of Kwale County, where field trials of the TRC have been previously conducted to assess farmers’ knowledge, perception, and practices towards the management of tsetse flies, their willingness to pay (WTP) for the TRC, and factors affecting the WTP. Almost all the respondents (90%) reported that tsetse flies were the leading cattle infesting pests in the area. About 22% of these correctly identified at least four AAT clinical signs, and even though many (68%) used trypanocidal drugs to manage the disease, 50% did not perceive the drug as being effective in AAT management (50%). Few respondents (8%) were aware of the harmful effects of trypanocidal drugs. About 89% of the respondents were aware oficipeTRC, and 30% of them were using the field trial collars during the survey. Sixty-three (63%) of them were willing to pay for the TRC at the same cost they spend treating an animal for AAT. On average farmers were willing to pay KES 3,352 per animal per year. Male educated household heads are likely to pay more for the TRC. Moreover, perceived high AAT prevalence and severity further increases the WTP. Wider dissemination and commercialization of the herd-level tsetse control approach (TRC) should be encouraged to impede AAT transmission and thus enhance food security and farm incomes among the affected rural communities. Besides the uptake of TRC can be enhanced through training, especially among women farmers.
Description of adverse events among adult men following voluntary medical male circumcision: Findings from a circumcision programme in two provinces of South Africa
Authors: Muchiri Evans , Charalambous Salome , Ginindza Sibuse , Maraisane Mpho , Maringa Tintswalo , Vranken Peter , Loykissoonlal Dayanund , Muturi-Kioi Vincent , Chetty-Makkan Candice M.
Published: August 2021

Background

Clinical trials showed strong evidence that voluntary medical male circumcision (VMMC) reduces the acquisition of HIV among heterosexual men by up to 60%. However, VMMC uptake in East and Southern Africa remains suboptimal, with safety concerns identified as a barrier to uptake. We investigated the occurrence and severity of adverse events (AEs) in a routine VMMC programme implemented in Gauteng and North West provinces of South Africa.

Methods

We describe the frequency and characteristics of AEs using routinely collected data from a VMMC programme implemented between 01 May 2013 and 31 December 2014. The surgical procedure was provided at fixed clinics and mobile units in three districts. Adult men undertaking the procedure were referred for follow-up appointments where AEs were monitored.

Results

A total of 7,963 adult men were offered the VMMC service with 7,864 (98.8%) met the age and consent requirements for inclusion in a research follow-up after the surgical procedure and were followed-up for potential AEs. In total, 37 (0.5%) patients reported AEs post-surgery with infection [11 (29.7%)] and excessive bleeding [11 (29.7%)] commonly reported AEs. In terms of severity, 14 (37.8%) were classified as mild, 13 (35.1%) as moderate, and 10 (27.0%) as severe. Further, 32 (86.5%) of the AEs were classified as definitely related to the surgical procedure, with 36 (97.5%) of all AEs resolving without sequelae.

Conclusion

The VMMC programme was able to reach adult men at high risk of HIV acquisition. Reported AEs in the programme were minimal, with the observed safety profile comparable to clinical trial settings, suggesting that VMMC can be safely administered in a programmatic setting.
Reevaluating the antiquity of the Palmrose site: Collections-based research of an early plank house on the northern Oregon Coast
Authors: Sanchez Gabriel M.
Published: August 2021

Large-scale excavations conducted by Smithsonian Institution archaeologists and avocational archaeologists during the 1960s and 1970s at three sites in Seaside, Oregon, resulted in the recovery of a diverse range of material culture curated by multiple institutions. One site, known as Palmrose (35CLT47), provides compelling evidence for the presence of one of the earliest examples of a rectangular plank house along the Oregon Coast. Previous research suggests habitation of the Palmrose site occurred between 2340 cal BC to cal AD 640. However, recent research highlights significant chronometric hygiene concerns of previously reported radiocarbon dates for the Seaside area, calling into question broader regional chronologies. This paper presents a revised chronology for the Palmrose site based on 12 new accelerator mass spectrometry (AMS) radiocarbon dates of ancient cervid bones. I evaluate these new dates and previously reported radiocarbon dates from the site, applying chronometric hygiene assessments and Bayesian statistics to build a refined chronology for the Palmrose site. Calibration of the 12 AMS radiocarbon dates suggests an initial occupation range from 345−55 cal BC and a terminal occupation range from cal AD 225−340−. Bayesian modeling of the Palmrose sequence suggests initial occupation may have spanned from195−50 cal BCand the terminal occupation from calAD 210−255. Modeling suggests the maximum range of occupation may span from580−55 cal BCtocal AD 210−300based on the start and end boundary calculations. Bayesian modeling of radiocarbon dates directly associated with the plank house deposits suggests the plank house’s occupation may have spanned from160−1 cal BCtocal AD 170−320. The new radiocarbon dates significantly constrain the Palmrose habitation and alter regional chronologies.
Polygenic scores for smoking and educational attainment have independent influences on academic success and adjustment in adolescence and educational attainment in adulthood
Authors: Hicks Brian M. , Clark D. Angus , Deak Joseph D. , Schaefer Jonathan D. , Liu Mengzhen , Jang Seonkyeong , Durbin C. Emily , Johnson Wendy , Wilson Sylia , Iacono William G. , McGue Matt , Vrieze Scott I.
Published: August 2021

Educational success is associated with greater quality of life and depends, in part, on heritable cognitive and non-cognitive traits. We used polygenic scores (PGS) for smoking and educational attainment to examine different genetic influences on facets of academic adjustment in adolescence and educational attainment in adulthood. PGSs were calculated for participants of the Minnesota Twin Family Study (N = 3225) and included as predictors of grades, academic motivation, and discipline problems at ages 11, 14, and 17 years-old, cigarettes per day from ages 14 to 24 years old, and educational attainment in adulthood (mean age 29.4 years). Smoking and educational attainment PGSs had significant incremental associations with each academic variable and cigarettes per day. About half of the adjusted effects of the smoking and education PGSs on educational attainment in adulthood were mediated by the academic variables in adolescence. Cigarettes per day from ages 14 to 24 years old did not account for the effect of the smoking PGS on educational attainment, suggesting the smoking PGS indexes genetic influences related to general behavioral disinhibition. In sum, distinct genetic influences measured by the smoking and educational attainment PGSs contribute to academic adjustment in adolescence and educational attainment in adulthood.
Socio-spatial relations observed in the global city network of firms
Authors: Sigler Thomas , Martinus Kirsten , Loginova Julia
Published: August 2021

One of the prevailing approaches to the study of the global economy is the analysis of global city networks based on the activities of multinational firms. Research in this vein generally conceptualises cities as nodes, and the intra-firm relations between them as ties, forming the building blocks for globally scaled interurban networks. While such an approach has provided a valuable heuristic for understanding how cities are globally connected, and how the global economy can be conceived of as a network of cities, there is a lack of understanding as to how and why cities are connected, and which factors contribute to the existence of ties between cities. Here, we explain how five distinct socio-spatial dimensions contribute to global city network structure through their diverse effects on interurban dyads. Based on data from 13,583 multinational firms with 163,821 international subsidiary locations drawn from 208 global securities exchanges, we hypothesise how regional, linguistic, industrial, developmental, and command & control relations may contribute to network structure. We then test these by applying an exponential random graph model (ERGM) to explain how each dimension may contribute to cities’ embeddedness within the overall network. Though all are shown to shape interurban relations to some extent, we find that two cities sharing a common industrial base are more likely to be connected. The ERGM also reveals a strong core-periphery structure in that cities in middle- and low-income countries are more reliant on connectivity than those in high-income countries. Our findings indicate that, despite claims seeking to de-emphasise the top-heavy organisational structure of the global urban economic network, interurban relations are characterised by uneven global development in which socio-spatial embeddedness manifests through a combination of similarity (homophily) and difference (heterophily) as determined by heterogeneous power relationships underlying global systems of production, exchange and consumption.
The cranial anatomy and relationships of Cardiocorax mukulu (Plesiosauria: Elasmosauridae) from Bentiaba, Angola
Authors: Marx Miguel P. , Mateus Octávio , Polcyn Michael J. , Schulp Anne S. , Gonçalves A. Olímpio , Jacobs Louis L.
Published: August 2021

We report a new specimen of the plesiosaurCardiocorax mukuluthat includes the most complete plesiosaur skull from sub-Saharan Africa. The well-preserved three-dimensional nature of the skull offers rare insight into the cranial anatomy of elasmosaurid plesiosaurians. The new specimen ofCardiocorax mukuluwas recovered from Bentiaba, Namibe Province in Angola, approximately three meters above the holotype. The new specimen also includes an atlas-axis complex, seventeen postaxial cervical vertebrae, partial ribs, a femur, and limb elements. It is identified asCardiocorax mukulubased on an apomorphy shared with the holotype where the cervical neural spine is approximately as long anteroposteriorly as the centrum and exhibits a sinusoidal anterior margin. The new specimen is nearly identical to the holotype and previously referred material in all other aspects.Cardiocorax mukuluis returned in an early-branching or intermediate position in Elasmosauridae in four out of the six of our phylogenetic analyses.Cardiocorax mukululacks the elongated cervical vertebrae that is characteristic of the extremely long-necked elasmosaurines, and the broad skull with and a high number of maxillary teeth (28–40) which is characteristic of Aristonectinae. Currently, the most parsimonious explanation concerning elasmosaurid evolutionary relationships, is thatCardiocorax mukulurepresents an older lineage of elasmosaurids in the Maastrichtian.
Association of obesity, visceral adiposity, and sarcopenia with an increased risk of metabolic syndrome: A retrospective study
Authors: Kim Su Hwan , Kang Hyoun Woo , Jeong Ji Bong , Lee Dong Seok , Ahn Dong-Won , Kim Ji Won , Kim Byeong Gwan , Lee Kook Lae , Oh Sohee , Yoon Soon Ho , Park Sang Joon
Published: August 2021

Aims

Metabolic syndrome (MS) is a global health problem associated with an increased risk of diabetes mellitus (DM), cardiovascular disease (CVD), and cancer. Body composition parameters, including obesity, visceral adiposity, and sarcopenia contribute to the development of MS and CVD. Previous studies have investigated the association of individual body composition parameters with MS. Studies analyzing the association between multiple body composition parameters and MS have been rare. We aimed to investigate the association between MS and multiple body composition parameters, including obesity, visceral adiposity, and sarcopenia.

Methods

A total of 13,620 subjects who underwent voluntary routine checkups at the Health Care Center of our institution between October 2014 and December 2019 were enrolled. Only data from the first examination of subjects who underwent repeated checkups were included. Clinical and laboratory data were collected. Skeletal muscle mass and visceral fat area (VFA) were measured using bioelectrical impedance analysis. Appendicular skeletal muscle mass (ASM) was divided by body weight (in kg) and expressed as a percentage (calculated as, ASM% = ASM × 100/Weight). Data were compared between the groups based on obesity, VFA, and ASM%. Logistic regression analysis was performed to determine the risk of MS in each group.

Results

Body mass index and VFA were significantly higher in subjects with MS than in those without MS. ASM% was significantly lower in subjects with MS than in those without MS. Subjects with obesity, visceral adiposity, or sarcopenia had a higher prevalence of MS than those without. As the number of metabolic components increased from 0 to 5, we identified a decreasing trend of ASM% and an increasing trend of VFA and BMI (P for trend < 0.001 for all). In the paired analyses, all the three body composition parameters showed additive effects in predicting MS. In the logistic regression analysis, the three parameters were associated with an increased risk of MS after adjustment for age, sex, hypertension, DM, dyslipidemia, smoking, alcohol intake, and C-reactive protein.

Conclusions

Obesity, visceral adiposity, and sarcopenia showed additive effects on MS prediction. Subjects with obesity, visceral adiposity, or sarcopenia were significantly associated with the increased risk of MS after adjustment for multiple confounders. Increasing skeletal muscle and reducing visceral fat may be strategies for the prevention or treatment of MS.
Developmental malformations resulting from high-dose maternal tamoxifen exposure in the mouse
Authors: Sun Miranda R. , Steward Austin C. , Sweet Emma A. , Martin Alexander A. , Lipinski Robert J.
Published: August 2021

Tamoxifen is an estrogen receptor (ER) ligand with widespread use in clinical and basic research settings. Beyond its application in treating ER-positive cancer, tamoxifen has been co-opted into a powerful approach for temporal-specific genetic alteration. The use of tamoxifen-inducible Cre-recombinase mouse models to examine genetic, molecular, and cellular mechanisms of development and disease is now prevalent in biomedical research. Understanding off-target effects of tamoxifen will inform its use in both clinical and basic research applications. Here, we show that prenatal tamoxifen exposure can cause structural birth defects in the mouse. Administration of a single 200 mg/kg tamoxifen dose to pregnant wildtype C57BL/6J mice at gestational day 9.75 caused cleft palate and limb malformations in the fetuses, including posterior digit duplication, reduction, or fusion. These malformations were highly penetrant and consistent across independent chemical manufacturers. As opposed to 200 mg/kg, a single dose of 50 mg/kg tamoxifen at the same developmental stage did not result in overt structural malformations. Demonstrating that prenatal tamoxifen exposure at a specific time point causes dose-dependent developmental abnormalities, these findings argue for more considerate application of tamoxifen in Cre-inducible systems and further investigation of tamoxifen’s mechanisms of action.
No evidence for parallel evolution of cursorial limb adaptations among Neogene South American native ungulates (SANUs)
Authors: Croft Darin A. , Lorente Malena
Published: August 2021

During the Neogene, many North American ungulates evolved longer limbs. Presumably, this allowed them to move more efficiently or quickly in open habitats, which became more common during this interval. Evidence suggests that open habitats appeared even earlier in South America, but no study to date has investigated whether the ungulate-like mammals of South America (South American native ungulates or SANUs) evolved similar limb adaptations. We analyzed limb elongation in the two predominant SANU groups, notoungulates and litopterns, by compiling genus-level occurrences from the late Oligocene to the Pleistocene and calculating metatarsal/femur ratio (Mt:F). None of the groups or subgroups we analyzed show a pronounced increase in Mt:F across this interval, with the possible exception of proterotheriid litopterns. Proterotheriids are thought to have inhabited forested environments rather than open ones, which raises questions about the selective forces responsible for limb elongation in ungulates. Conversely, notoungulates, which are traditionally thought to have lived in open habitats, show no strong trend of increasing Mt:F across this interval. Our study suggests that the macroevolutionary trend of limb elongation in ungulate-like mammals is not universal and is highly influenced by the evolutionary affinities of the groups being analyzed.
CXCL1: A new diagnostic biomarker for human tuberculosis discovered using Diversity Outbred mice
Authors: Koyuncu Deniz , Niazi Muhammad Khalid Khan , Tavolara Thomas , Abeijon Claudia , Ginese Melanie L. , Liao Yanghui , Mark Carolyn , Specht Aubrey , Gower Adam C. , Restrepo Blanca I. , Gatti Daniel M. , Kramnik Igor , Gurcan Metin , Yener Bülent , Beamer Gillian
Published: August 2021

More humans have died of tuberculosis (TB) than any other infectious disease and millions still die each year. Experts advocate for blood-based, serum protein biomarkers to help diagnose TB, which afflicts millions of people in high-burden countries. However, the protein biomarker pipeline is small. Here, we used the Diversity Outbred (DO) mouse population to address this gap, identifying five protein biomarker candidates. One protein biomarker, serum CXCL1, met the World Health Organization’s Targeted Product Profile for a triage test to diagnose active TB from latent M.tb infection (LTBI), non-TB lung disease, and normal sera in HIV-negative, adults from South Africa and Vietnam. To find the biomarker candidates, we quantified seven immune cytokines and four inflammatory proteins corresponding to highly expressed genes unique to progressor DO mice. Next, we applied statistical and machine learning methods to the data, i.e., 11 proteins in lungs from 453 infected and 29 non-infected mice. After searching all combinations of five algorithms and 239 protein subsets, validating, and testing the findings on independent data, two combinations accurately diagnosed progressor DO mice: Logistic Regression using MMP8; and Gradient Tree Boosting using a panel of 4: CXCL1, CXCL2, TNF, IL-10. Of those five protein biomarker candidates, two (MMP8 and CXCL1) were crucial for classifying DO mice; were above the limit of detection in most human serum samples; and had not been widely assessed for diagnostic performance in humans before. In patient sera, CXCL1 exceeded the triage diagnostic test criteria (>90% sensitivity; >70% specificity), while MMP8 did not. Using Area Under the Curve analyses, CXCL1 averaged 94.5% sensitivity and 88.8% specificity for active pulmonary TB (ATB) vs LTBI; 90.9% sensitivity and 71.4% specificity for ATB vs non-TB; and 100.0% sensitivity and 98.4% specificity for ATB vs normal sera. Our findings overall show that the DO mouse population can discover diagnostic-quality, serum protein biomarkers of human TB.
A Study on Glycosylated Haemoglobin Values at 6 - 12 Weeks of Pregnancy as an Early Predictor of Gestational Diabetes Mellitus
Authors: Rex Staeny , Agarwal Preet , Murugesan Sarmishta , K.S Rajeshwari
Published: August 2021

BACKGROUND Gestational diabetes mellitus (GDM) is a major health problem arising due to insulin resistance in pregnant women. It is associated with multiple maternal complications which may cause end organ failure, complicated labour and delivery and thereby increasing the maternal morbidity and mortality. The foetus is also at risk for problems beginning from in utero and extending into the neonatal period and adult life. We wanted to correlate first trimester HbA1c values with the subsequent development of gestational diabetes mellitus and identify if glycosylated haemoglobin can be used as an adjunct with other screening methods. METHODS It is a prospective cohort study. This study was conducted from August 2015 to August 2017. All women of gestational age 6 to 12 weeks who came to Sri Ramachandra University outpatient department were taken for this study. Informed consent was obtained and a detailed history taking was done as per proforma. Along with routine antenatal investigations, Glycosylated haemoglobin (HbA1c) was also done. Oral Glucose Tolerance Test was to be performed at 24 - 28 weeks as per the World Health Organisation –with 75gm criteria and the results were tabulated and analysed to know the significance of Glycosylated haemoglobin (HbA1c) in the outcome of gestational diabetes mellitus. Further a fasting and postprandial blood sugar was done in the 3rd trimester for all patients as a secondary screening tool for gestational diabetes mellitus. Secondary outcomes of obstetric and neonatal complications were also studied. RESULTS In the present study a total of 323 patients were screened for HbA1c during the first trimester and followed till delivery. Only 21.9 % developed gestational diabetes mellitus. Elevated Glycosylated haemoglobin (HbA1c) value of 5.7 - 6.4 % was seen in 5.9 %. CONCLUSIONS Most of the patients with elevated Glycosylated Haemoglobin in the first trimester had high chance of developing gestational diabetes mellitus. Glycosylated haemoglobin is indeed a simple way of screening, but its solitary use remains controversial and hence could possibly be tried as an adjunct with other screening methods. KEY WORDS Glycosylated Haemoglobin, Gestational Diabetes Mellitus, Glycaemic Control, Maternal and Foetal Morbidity and Mortality
Fiber Reinforced Composite Space Maintainers Versus Band and Loop Space Maintainers – A Systematic Review
Authors: Padmanabhan Vaishnavi , Kishore Shreya , S Suvetha
Published: August 2021

BACKGROUND Premature loss of primary teeth requires orthodontic intervention to prevent the occurrence of malocclusions in the future. The most preferred way to maintain this space is by using space maintainers. Band and loop maintainers are the most commonly used fixed space maintainers. Despite being the most effective, it has several disadvantages. Hence, the objective of this review was to compare the efficiency between fiber reinforced composite (FRC) space maintainer and the conventional band & loop space maintainer. METHODS A systematic review was performed. Electronic and hand search retrieved 260 records, 246 were screened. The intervention and outcomes were assessed in the study included for systematic review. RESULTS Seven studies were included in this systematic review. These studies compared the fiber reinforced composite and the conventional band & loop and provided results about their clinical efficacy and patient satisfaction. CONCLUSIONS Despite being one of the gold standard appliances for space maintenance, the conventional band and loop space maintainers have multiple disadvantages. The major disadvantages included failure of the appliance due to cement loss and bending of the wire. Out of the 7 articles included in this study, 6 of the articles concluded that the FRC space maintainers are as effective as the conventional band and loop. FRC space maintainers proved to be time effective, more aesthetic, has better patient acceptance and is easier to fabricate. Hence, fiber reinforced composite space maintainers can be used as a more aesthetic and effective alternative to the conventional band and loop space maintainers if proper technique and protocol is followed. KEY WORDS Space Maintainers, Band and Loop Space Maintainer, Fiber Reinforced Space Maintainer, Interceptive Orthodontics, Orthodontics
Kispadra ültetett desztinációmenedzsment a pandémia félidejében(?) = „Kept on the bench” – Destination Management at “half-time” in the pandemic(?)
Authors: Nod Gabriella , Mókusné Pálfi Andrea , Aubert Antal
Published: August 2021

A COVID-19 turisztikai hatásait vizsgáló kutatások sora jelent meg az elmúlt időszakban, melyek leginkább az átalakuló utazói preferenciákat vizsgálják (Güliz Uğur–Akbiyik 2020, VARGAS 2020, Li–Ito 2021, UKPABI et al. 2021), ugyanakkor a frissen megjelent publikációk nem foglalkoznak a jó gyakorlatokkal, a válságkezelésre vonatkozó stratégiák megosztásával és a közös gondolkodással a turizmus nyitást követő újraélesztése kapcsán. Ezért szeretnénk az elsők között megosztani a magyar turisztikai desztinációmenedzsment (TDM) szervezetek körében végzett felmérésünk eredményeit, melyek segíthetik az egyes szervezetek közti tapasztalat- és információcserét, valamint értékes gondolatokkal járulhatnak hozzá a stratégiai tervezéshez is. A világjárvány okozta válság több gazdasági ágazatot is jelentősen érintett, a turizmusra gyakorolt negatív hatásaira számos példát látunk már most. Az egyes turisztikai szereplőkre nagy nyomás nehezedik a kialakult helyzetben, így többek között a TDM szervezetek munkáját is a járvány határozza meg. Tanulmányunk rávilágít arra, hogy a járvány hatására hozott intézkedések hogyan hatottak a TDM szervezetek működésére, milyen új feladatok jelentek meg a tevékenységükben, hogyan tudnak segíteni tagjaiknak a korlátozások ideje alatt, és hogy egyáltalán hogyan tekintenek a jövőbe.
PREVALENCE OF FRAILTY AND MOBILITY LIMITATION IN A RURAL SETTING IN FRANCE
Authors: CESARI M. , DEMOUGEOT L. , BOCCALON H. , VELLAS B.
Published: August 2021

Background:The prevalence of frailty is variable according to the adopted operational definition, thetested population, and the setting where it is explored. Objective:To estimate the prevalence of frailty andmobility disability in community-dwelling persons aged 60 years and older. Design:Cross-sectional analyses.Setting:The rural area of Labastide-Murat (France). Participants:All community-dwelling persons aged 60years and older living in the area and answering to the study survey (n=572/1022). Measurements: The studyquestionnaire included questions defining mobility disability (as ability to walk 400 meters and climb up 2 flightsof stairs) and frailty (according to the FRAIL instrument and a modified version of the original definitionproposed by Fried and colleagues). Results:Mean age of participants was 72.4 years old. Mobility disability wasreported by 47 (8.3%) participants. The sedentariness criterion of frailty was the most prevalent in the presentpopulation. Overall, according to the FRAIL instrument, 77.6%, 14.0%, and 8.3% could be defined as robust,pre-frail/frail, and disabled, respectively. When the alternative definition of frailty mirroring the definitionproposed in the Cardiovascular Health Study was adopted, the prevalence of frailty increased and showedgender-specific differences (p=0.02). Conclusions:A relevant number of older persons living in rural areasexperiences physical impairments and presents an increased risk for major negative health-related events. Theseresults may support the ongoing clinical and research actions aimed at preventing the functional decline in elders.
Characterizing Proficient Teachers as Teacher-Leaders in a Public Secondary School of Leyte Division
Authors: Manito Alvin Jhon
Published: August 2021

Abstract: This case study determines the ability of the classroom teachers of becoming teacher-leaders in school reform in the absence of highly proficient teachers and department heads in the institution. This study aimed to explore and characterize proficient teachers as teacher-leaders at Manlilisid National High School, Javier II District, Leyte Division. This study used mixed method investigative paradigm as its research design. Quantitatively, data were gathered using the Teacher Leadership Self-Assessment (TLSA) by Katzenmeyer and Katzenmeyer (2004). It was randomly distributed to thirteen proficient teachers. Qualitatively, a semi-structured interview was done to three proficient teachers who got highest ratings in the survey. The respondents granted permission to the researcher to use the data obtained. Data were then analyzed using descriptive statistics and thematic analysis. Upon the analysis, the characteristics of the proficient teachers as teacher-leaders are evident in self-awareness, diversity, and instructional proficiency. The school can also foster teacher leadership through the determined themes - initiative and independence, partnership engagement and teamwork, and positive school environment. This study can also be a subject for further research to analyse if there is a significant difference between these types of leadership behaviour, and use the same method and instrument but is implemented in a larger population.
Pridnestrovie
Authors: Napolitano Francesco
Published: August 2021

This work is the result of a research made by the author in 2010, under the guide of Fabio Bettanin, professor of Eastern Studies at the University of Naples “L’Orientale”. It focuses on Pridnestrovie, a small patch of land, legally belonging to the Moldavian Republic, located between the eastern bank of the Dniester River and the Moldovan border with Ukraine. Pridnestrovie, during the Soviet period hosted most of the industries located in the Moldavian Soviet Socialist Republic. In the aftermath of perestroika and the collapse of the USSR, Pridnestrovie declared, with the support of Moscow, its independence from Chinisau.