bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystal Growth and Properties of Photorefractive Barium Titanate
Authors: Pollak T.M. , Schunemann P.G.
Published: February 2023

The photorefractive properties of BaTiO3 are sensitive to the powder processing and crystal growing techniques. Variations in starting materials, and growth or annealing atmosphere have been shown to significantly impact the concentration and characteristics of photorefractive charge carriers. We have addressed the optimization of the electronic structure of BaTiO3 by examining process atmosphere and melt additives with the goal to improve the photorefractive sensitivity within the visible and near infrared spectrum.
Nanosecond Selfdiffraction Electrogyration in the crystal of Bi12TiO20 (BTO)
Authors: Brodin M.S. , Volkov V.I. , Kukhtarev N.N. , Privalko A.V.
Published: February 2023

Recently there has been considerable current interest in studies of photorefractive materials. It is mainly due to ample prospects of their applications in the wave-front conjugation, optical data processing, laser-emission control, optical amplification of images, adaptive holographic interferometry and so on. However write an erase times in these materials, typically miliseconds to seconds under continuous wave illumination, are slower required for many applications. For this reason, investigations of such well-known photorefractive substances as BaTiO3,Bi12TiO20 and Bi12GeO20 have been extended to the case of pulse pumping in the nanosecond and picosecond ranges. The obtained results indicated that the photorefractive effect can be observed in the nanosecond range as well, though the corresponding efficiency is lower than that achieved under continuous wave pumping.
Mechanisms of photochromic and photorefractive effects in double doped LiNbO3
Authors: Vartanyan E.S. , Micaelyan R.S. , Hovsepyan R.K. , Pogosyan A.R.
Published: February 2023

The Lithium niobate crystals doping is effective photo-induced crystals properties influence method. Therefor, this paper was devoted to experimental investigations of photorefractive and photochromic effects in lithium niobate crystals, doping with Fe: Mn, Fe: Cu, Fe9Ti and Fe: Hf impurity combinations. Separately doping with Fe, Cu, Ti, Hf crystals were used for comparison in experiments. The crystal absorbtion spectrums show, that the impurities interact in spite of small concentrations. Photorefractive sensibility determination was corried out with careful in this work.
The Application of Holographic Interferometry in Nondestructive Testing Technique
Authors: Dovgalenko G.E. , Eskov-Soskovetz V.M. , Skorikov V.M. , Kargin J.P. , Volkov V.V.
Published: February 2023

Application of photorefractive silverless materials (photorefractive crystals Bi12Ti O20), as media for holographic recording is of a considerable interest for researchers since it is possible to use them in real time systems of nondestructive technical control. Higher recording sensitivity of media Bi12Ti O20 which can be compared with the best silverincluding materials type Kodak -649 -F, together with reversibility (practically unlimited number of optical information record and readout cycles) make the given media sufficiently, prospective for various tasks of technical control. The authors represent the results of the application of the given media in the systems of Hybrid Optical Electron Complexes -HOEC, in which input, preliminary processing and output of information are optical, and the final information processing is performed by a computer.
Development of a Space Interferometer Using LiNbO3-Fe Crystal as Holographic Support
Authors: Marry J. , Bernard Y. , Lefaucheuh F. , Cadoret J.P.
Published: February 2023

HOLIDDO instrument (French acronym for holographic interferometry in two observation directions) will be used to characterize transparent objects in a microgravity environment.(J. Mary et al)
Polarization and Dispersion of Light in the Anisotropic Fiber-Crystal System in Phase Conjugation
Authors: Kuchtarev N.V. , Lapaeva S.N. , Volyar A.V.
Published: February 2023

Polarizing light characteristics have been researched theoretically and experimentally in the anisotropic-multimode fiber crystal system in phase conjugation. It has been shown that in multiple phase conjugation a mode dispersion may be completely compensated in an isotropic cylindrical fiber caused by polarizing phase conjugation pertubation. It has been obtained in a matching anisotrboic fiber-crystal LiNbO3 system it is possible to transmit polarized light with a given ellipticity value.
Implementations of Neural Networks Based on Photorefractive Beam Fanning
Authors: Owechko Y. , Soffer B. H.
Published: February 2023

The great success of conventional computers and procedural programming techniques in solving algorithmic problems in science and engineering contrasts with the far slower progress in solving the ill-defined problems at which humans and animals excel, such as recognizing individual faces.
Optical Devices Based on Photo-induced Index Changes in Silica
Authors: Glass A. M.
Published: February 2023

The discovery of photo-induced index changes in silica has formed the basis for a large number of novel optical devices. This talk reviews both fiber and planar waveguide devices of interest for communications.
Holographic Determination of The Photogalvanic Tensor in LiNbO3: Fe
Authors: Kukhtarev N. , Semenets T. , Knyaz'kov A. , Lobanov M.
Published: February 2023

For the first time both symmetric and antisymmetric parts of circular photogalvanic current were found during holographic gratings writing in LiNbO3: Fe.
Time resolved build-up of the photorefractive effect produced in Bi12SiO20 by picosecond light pulses
Authors: Jonathan J.M.C. , Roosen G. , Roussignol Ph.
Published: February 2023

The photorefractive effect in electro-optic and photoconductive crystals allows a large variety of operations in the field of optical signal processing.
Anisotropic Conical Diffractions in a BaTiO3 Crystal
Authors: Chen Wen-Hsien , Peng Cheng-Miao , Yeh Pochi
Published: February 2023

We report the observaton of anisotropic diffracted rings when a BaTiO3 crystal is illuminated with a laser beam. The rings are nonphotorefractive in nature and appear instantaneously.
The Role of Tunable-Transmitter Wavelength-Division-Multiplexing Star-Coupler Architecture in High-Performance Multigigabit Asynchronous-Transfer-Mode Switching
Authors: Santoro M. A. , Eng K. Y.
Published: February 2023

Many ongoing efforts to implement large-size, multi-gigabit ATM switches have been motivated by the fact that Asynchronous Transfer Mode (ATM) is becoming a standard for B-ISDN applications. The different approaches incorporate both electronic and photonic designs. We continue to investigate photonic designs in this area which are cost-effective compared to electronic designs and are feasible with present photonic technology. Our design goal is to implement a large ATM switch (in excess of 256 lines) with a data rate of 2.5 Gb/s per line. We concentrate on photonic implementations which use star-coupler based, WDM techniques. In this presentation we propose an architecture which, by incorporating the best features of some of the previous designs, offers the best possible switching performance in terms of delay-throughput characteristics but requires the smallest number of wavelengths and a simple control mechanism, independent of the switch size.
Management of Optical Networks
Authors: Johansson Sonny , Brodd Anna , Elander Kuno
Published: February 2023

Management of optical network is an issue that is not very much discussed. Traditionally, we are only considering the transport aspects when optical networks are treated. We can define the transport view reaching from the basic generation of bits to the abstract level dealing with network functional architecture described by functions and reference points. These are all issues that tell us how to transport traffic between different locations.
Who will be the winner, photonics, electronics or photo-electronics?
Authors: Ikegami Tetsuhiko
Published: February 2023

Once ‛photonic switching’ has been demonstrated, the performance has been taken over by electronics in a past decade, like the competition between GaAs and Si in the microelectronics technologies. Recently, bit greedy telecommunication services like Multimedia are coming up and multi-wavelength networking, in which multi-wavelength will be used for new functions, not for a simple idea of increasing channel capacity, is revealing a new horizon to ‛photonic switching’. We will discuss how to share each role of photonics and electronics in the emerging field.
Electro-Nanomechanically Activated Integrated-Optical Interferometric Switches
Authors: Dangel R. , Lukosz W.
Published: February 2023

We demonstrate new electro-nanomechanically activated integrated-optical (IO) 2×2 switches with sub-milliseconds switching times. The switches consist of Mach-Zehnder interferometers (MZI's) with multimode interference couplers (MMI's) as splitters and combiners. Switching from the cross- to the bar-state is effected as follows: attached to the waveguide-chip is an "effective-refractive-index-shifting element" E in form of a micro- machined cantilever protruding over one leg of the interferometer. By nanometer-deflections of the cantilever under electrostatic forces, the width d of an air gap between the element E and the rib waveguide is changed. Thus, a phase shift of π is induced by the IO nanomechanical effect [1,2].
The Role of Photonics in Future Broad Band Networks
Authors: Ericson Bernt
Published: February 2023

Fibre optics has been the key technology to provide low cost long distance communication. The explosive growth on Internet and high expectations on other interactive services will be the next challenge for photonics.
Hyper-media Photonic Information Network
Authors: Yukimatsu Ken-ichi , Matsunaga Tohru , Hiramatsu Atsushi
Published: February 2023

We believe that the photonic technology will not only increase the network capacity dramatically but also change the communication network architecture from the bottom. A hyper-media photonic information network (HM-PIN) [1, 2] is our present solution for the future network architecture, where the photonic technology dramatically simplifies the communication network structure. This paper summarizes the concept of the hyper-media network and the current status of our photonic switching technologies.
Study of ultra-thin films in multilayer structures by standing -waves and small- angle x-ray scattering techniques
Authors: Fraerman A.A. , Platonov Yu. Ya. , Polushkin N.I. , Salashchenko N.N. , Zheludeva S.I. , Kovalchuk M.V. , Novikova N.N. , Bashelhanov I.V. , Shubnikov A.V.
Published: February 2023

The traditional method for LSM parameters investigation uses small angle x-ray diffraction at λ=0.1nm. The parameters of interest have been determined by comparing the theoretical angular dependencies of reflectivity as a functions of these parameters with the experimental curves.
Imaging X-Ray Multilayer Structures with Cross-Sectional HREM
Authors: Cheng Y. , Stearns M.B. , Smith D.J. , Stearns D.G.
Published: February 2023

High-resolution electron microscopy (HREM), with a resolution below 2Å, is the best tool for observing the actual detailed structure for ML. This gives direct atomic scale information about the film structure, including the bilayer thickness, the crystalline structure and the roughness of the individual layers and the interlayers.
Soft X-Ray Multilayer Mirrors
Authors: Zhengxiu Fan , Jianda Shao
Published: February 2023

The present status of studies on soft x-ray multilayer mirrors in our institute are described. These include the optinum design, deposiion technique and the preliminary characterizations. W/C, Ta/Si, Mo/Si, Mo/Al multilayers, which are designed as mirrors at 105A, 135A and 234A respectively, have been fabricated with DC- and RF- plane magnetron sputtering system. Small Angle Diffraction with Cu-Ka radiation, Transmission Electron Microscopy and Auger Electron Spectroscopy have been applied to investigate the informations about the interfaces and the layer thickness monitor random errors and the roughness of the layer systems. Our reflectometer have also given us some informations about the optical constants.
Crystal Balls and Technology
Authors: Freeman R. R.
Published: February 2023

Just what direction lithography will take in the future is the product of advances in technology times the wishes of the user community. Since all we can influence is technology, we have to prepare ourselves for disappointments in the final answer.
MO-SI MULTILAYER AS SOFT X-RAY MIRRORS FOR THE WAVELENGTHS AROUND 20 NM REGION
Authors: Kim D. , Lee H.W. , Lee J. J. , Je J. H. , Sakurai M. , Watanabe M.
Published: February 2023

Molybdenum-silicon multilayer soft x-ray mirrors have been fabricated using a magnetron sputtering system. Their structures have been characterized by x-ray diffraction (XRD) and reflectivities at normal incidence have been measured by using monochromatized synchrotron radiation in the 18-24 nm region. A normal incidence reflectivity as high as 40% at 20.8 nm was achieved.
Recent Developments in X-Ray Astronomy
Authors: Golub L.
Published: February 2023

We focus on aspects of the past, present and future of multilayer optics in Solar astrophysics. Space flights, mostly on sounding rockets, will be discussed and some future satellites which use multilayers for imaging and/or spectrocopy will be presented.
Thermal Stability of Multilayers
Authors: Greer A. L.
Published: February 2023

Multilayers are unstable, showing interdiffusion, reactions, phase transformations and coarsening. Special features arise because of small distances or high chemical driving forces.
Spatial Shift of X-ray Beam Reflected by Multilayer Structure
Authors: Vinogradov A. V. , Popov A. V.
Published: February 2023

The effect lies beyond the frames of geometric optics. We evaluate it in terms of the theory of Gaussian beams. The results can be important for zone plates and Bragg-Fresnel lenses.
Quantum-limited image reconstruction in nuclear medicine
Authors: Barrett H. H. , Aarsvold J. N. , Roney T. J. , Rowe R. K.
Published: February 2023

There is probably no imaging modality more severely limited by quantum noise than nuclear medicine. A typical diagnostic gamma-ray image may consist of only 5,000 detected photons, and there are almost never more than 500,000 photons in the entire image. The images invariably have low resolution and high noise. Yet the goals of nuclear medicine are quite ambitious; often one wants to have quantitative information about the distribution of a radioisotope in three or even four dimensions. Thus there is an overwhelming need to design data-acquisition systems and image reconstruction algorithms so as to make the best possible use of the available gamma-ray quanta. For this reason nuclear medicine is an important test bed for studying the problems of quantum-limited imaging in general.
Modulation of Excitonic Quenching in a Selectively Doped Single Quantum Well
Authors: Tombling C. , Stallard M.M. , Roberts J.S.
Published: February 2023

Recently the characteristic optical absorption of quantum well structures under the influence of an electron (or electron-hole) plasma has attracted much attention in both modulation doped structures1,2and optically non-linear devices3. We present here the first direct experimental evidence of room temperature excitonic recovery in a depletion mode selectively doped GaAs single quantum well. Quenching of the excitonic resonance is achieved in this type of structure when the electron Fermi level in the quantum well exceeds the energy of the nz=1 sub-band, as the states normally available for absorption are filled3. The carrier concentration in the quantum well is varied by a pn junction, effectively enabling the transition from a doped to an undoped quantum well to be observed. Mesa etched photodiodes and slab waveguide structures are considered in this work and both reveal the recovery of an excitonic peak. The modulation of absorption achieved is Δα ≈8000cm−1.
Band Structure and Optical Properties of Short Period Si/Ge Superlattices
Authors: Abstreiter G.
Published: February 2023

Summary not available.
Dependence of Alexandrite Laser Pumped Tm:Ho:YAG and YLF Lasers on System Parameters
Authors: Han Gyoowan , Hwang In H. , Lee Chang J. , Bair Clayton H. , Barnes Norman P. , Brockman Philip , Hess Robert V.
Published: February 2023

The Ho:Tm laser performance has been characterized under a variety of conditions using an alexandrite laser to simulate diode laser pumping. Both Tm:Ho:YAG and Tm:Ho:YLF have been evaluated and compared. Tm concentration was kept nominally constant at 4 %. Laser rods of different length were evaluated. For a 1.5 % Ho concentration in YLF, with pump pulse of 200 µs, a slope efficiency as high as 50 % is obtained for 6 mm long crystal. In general higher slope efficiencies are achieved in Tm:Ho:YLF than in Tm:Ho:YAG.
Wide Angle Michelson Doppler Imaging Interferometer
Authors: Shepherd G.G. , Gault W.A.
Published: February 2023

A field-widened Michelson interferometer with an imaging detector is planned for Spacelab to acquire images of temperature and winds from upper atmospheric line emissions.
An Ocean Atmospheric Radiation Computation Method For Remote Specral Measurement Data Analysis
Authors: Kim Hongsuk H. , Hart William D.
Published: February 2023

An ocean atmospheric radiation computation method which determines the lower boundary ocean surface albedo and other radiation components from spectral measurements of upwelling radiance taken from a high altitude platform has been developed. The method was originally used to process multi spectral ocean color scanner data to determine the influence of chlorophyll in the sea on the ratio of upwelling radiance to downwelling irradiance as a function of wavelength. In order to measure very subtle color shifts in the blue-green region the effects of atmospheric radiation on the spectral channels have to be determined correctly. The analysis method can also be used to study atmospheric radiance over the sea by removing the water radiance component.
Simulation of Heterodyne Detection From Aerosols
Authors: Altman W. P.
Published: February 2023

Wind sensors operating at 10 microns rely on the heterodyne detection of atmospheric aerosol scattering and subsequent processing to measure mean Doppler shifts. A simulation of heterodyne detector output was performed based on a model of randomly distributed aerosol point scatterers illuminated by a single frequency laser pulse.
Upper Atmospheric Temperatures and Excited State Densities from Spire Earth-Limb Infrared Radiances
Authors: Green B. D. , Caledonia G. E. , Nadile R. M. , Stair A. T.
Published: February 2023

High altitude measurements of spectrally-resolved atmospheric infrared fluorescence provide the necessary input for upper atmospheric model verification and refinement. Perhaps the most definitive survey of infrared radiance in the quiescent upper atmosphere was completed in the SPIRE measurement program conducted by the Air Force Geophysics Laboratory. In this mission a rocketborne instrumentation package was launched into the dawn terminator over Poker Flats, Alaska, in September of 1977. The goal of the program was to measure the atmospheric limb infrared radiance for tangent heights between hard earth and 250 km under both sunlit and dark conditions. To achieve this, the payload was sequentially scanned through the earth limb and was oriented at different angles relative to the sun. In this manner regions with a variety of illumination times were observed. One of the diagnostics employed on this flight was a liquid-helium-cooled circular variable filter (CVF) spectrometer capable of monitoring long-wavelength infrared emission in the 8.7 - 16.5 μm region with a spectral resolution of approximately 2% of the wavelength.
VAS-E: Inflight Evaluation of an Atmospheric Sounder on a Geostationary Satellite
Authors: Menzel W. Paul , Smith William L. , Hayden C. M.
Published: February 2023

Soundings from a geostationary platform are compared with soundings from radiosondes, ground based microwave (profiler) data, and polar orbiting satellites. Discrepancies related to differences in the measurement technique are studied. Methods of amalgamating these different observation types are discussed.
Feasibility Of A Fourier Transform Spectrometer (FTS) For The Advanced Moisture And Temperature Sounder (AMTS)
Authors: Poultney S. , Zink D. , Pires A. , Dybwad P. , Oberheuser J. , McGlynn C. , Callan D. , Niple E. , Miller M. D. , Vogel H. , Gowrinathan S.
Published: February 2023

This study1 investigated the feasibility of using a Fourier Transform Spectrometer (FTS) approach for the Advanced Moisture and Temperature Sounder (AMTS) in support of the Jet Propulsion Laboratory (JPL) effort to design an advanced passive infrared sounding system. The FTS approach holds promise in several operational areas, but its unique means of encoding, recording, and retrieving spectro-radiometric information raised questions about its feasibility.
Measurement of H2O Vapor Profiles Using A Solar Blind Raman Lidar
Authors: Salik A. , Petri K. , Cooney J.
Published: February 2023

In the system described, the lidar transmitter is a krypton fluoride (KrF) excimer laser which operates at an output wavelength of 248.5 nm. This laser has an output pulse energy of 0.75 joules in a 20 ns pulse with a pulse repetition rate of 1 Hz. In addition, the lidar is equipped with a 30-inch primary mirror and 2 RCA C31005 photomultipliers. A dual channel system is employed in order to receive and record two signal profiles simultaneously.
Spectroscopy in Radiometry
Authors: Gille John C.
Published: February 2023

Parameterized line-by-line calculations are often used to interpret accurate radiometric measurements. These require line parameters with temperature dependencies, line shapes and other information.
Spectroscopy of Electronically Excited States
Authors: Innes K.
Published: February 2023

Illustrations of the diverse approaches necessary for understanding excited states will be offered in discussions of spectra of NO, N2O, NO2, ClO2, O3 and H2CO.
Line Positions and Energy Levels
Authors: Rao K. N.
Published: February 2023

Summary not available.
Far Infrared Measurability of HCl, OH, H2O2, HO2 and HOCl
Authors: Chance Kelly V. , Traub Wesley A.
Published: February 2023

Rotational transitions in a number of important stratospheric trace molecues can potentially be accurately measured by far infrared spectroscopy. HCl, OH, H2O2, HO2 and HOCl have large rotational constants due to the reduced mass of hydrogen plus other, heavier, constituents. The polyatomics in this group are all nearly symmetric prolate tops (NSPTs) having strong Q branches (b-type selection rules, ΔJ=0, ΔK=1) that are sufficiently compact to be seen as relatively sharp features in atmospheric spectra. All the molecules are characterized by reasonably large dipole moments (μb for the NSPTs) and small partition functions, if we consider only partitioning among the Ki for the NSPTs.
Photoabsorption in the Schumann-Runge Bands and Continuum of O2
Authors: Blake A.J. , McCoy D.G. , Gies H.P.F. , Gibson S.T.
Published: February 2023

Extensive laboratory measurements of photoabsorption in the Schumann-Runge bands and continuum of molecular oxygen have been made using The University of Adelaide six-metre vacuum ultraviolet monochromator. These measurements have shown for the first time rotational dependence in the band oscillator strengths and have provided comprehensive information about linewidths which is essential to an understanding of predissociation in the band system. The technique used to extract these values from the experimental data will be outlined, together with the results.
Intensity of the H2O2 v6(b) Band at 1266 cm−1.
Authors: Valero Francisco P. J. , Goorvitch David , Bonomo Francis , Boese Robert W.
Published: February 2023

The hydrogen atom radicals (H, OH, HO2 and H2O2) are probably the least understood of the atmospheric trace constituents. An effort is necessary to obtain a more detailed knowledge of the behavior of the hydrogen radicals and their close relative H2O2. The hydrogen gases were proposed as ozone-destructive agents in air long before the discovery of nitrogen oxides as similar agents.
Performance of Norton Code 7997 3µ Cut Rate Enhanced Precision Alumina Slurry
Authors: Rostoker David
Published: February 2023

In any lapping operation, especially when lapping precision optical materials, there is always a compromise between cut rate and finish. The most desirable finish is one that leaves the surface sufficiently smooth and free from sub-surface damage that reduces polishing time.
The Surface Structure of Machined Optical Glass
Authors: Liegong Wu , Qiming Xin , Parks Robert E.
Published: February 2023

Eight kinds of optical glass were ground with loose abrasive SiC and sintered diamond tools. The machined surfaces were examined with an electromicroscope. It had been found that the surface cracks of glass were distinguished from the network structure as known before, instead it appeared slice-shaped and overlapped. This new discover will be benifit to the study on the mechanism of grinding of optical glass.
Observation of persistent spectral hole–burning in semiconductor nanocrystals
Authors: Masumoto Yasuaki , Zimin Lev G. , Naoe Kazuhiko
Published: February 2023

So far, persistent spectral hole-burning (PSHB) phenomenon has been observed in a number of materials. They are molecules in glasses, crystals and polymers, color centers in alkali halide crystals, and rare earth and transition metal ions in glasses and crystals. They are molecular or ionic guests embedded in glass, crystal or polymer hosts. Basic requirements for the PSHB are summarized as follows: (1) The optical absorption of guests embedded in hosts must be broadened inhomogeneously. (2) There must exist more than one ground state configurations of the total system consisting of guests and hosts. (3) The relaxation among the ground states must be slower than the decay rate of any excited state. In fact, this set of requirements is satisfied in many kinds of molecular or ionic guests in hosts, such as glasses, crystals and polymers, at low temperatures. We can naturally understand that guests consisting of small number of atoms are greatly influenced by the surrounding hosts and that the energy levels of the guests are inhomogeneously broadened.
Photochemical indused change in infrared reflection spectra of silicates
Authors: Mukhamedgalieva Anel F. , Bondar Anatolii M.
Published: February 2023

The change in infrared reflection spectra of natural silicates caused by CO2 laser action on the surface of these matters has been investigated. The matters mentioned above have intensive inhomogeneously broadened infrared absorbtion band of assymmetric valent Si-O-Si vibrations at the range of laser action, that provide intensive absorbtion of laser energy. The laser action on these matters lead to the intensive sublimation of matter with torch formation at the irradiated surface.
Near Field Phase of Diode Arrays: Measurements and Supermode Theory
Authors: Wilson Kimberley , Dente Gregory , Depatie David
Published: February 2023

Considerable effort has gone into the design, fabrication and testing of semiconductor laser arrays as researchers try to obtain highpower concentrated into a diffraction limited far-field. Unfortunately, many of the designs lead to an undesirable twin-lobed far-field. Furthermore, in those few cases that reported single-lobed performance, the single lobe typically exceed the diffraction limit. Near-field phase measurements of a semiconductor laser array can provide valuable insight into the device performance. In this paper we report on measurements at the output facet of semiconductor lasers and laser arrays using a simple self-referencing interferometer (1) that allows accurate phase measurements, typically 1/30 of a wavelength.
Distributed Bragg Reflector Lead Salt Diode Lasers for Operation Above 77 K
Authors: Shani Y. , Katzir A. , Norton P. , Tacke M. , Preier H.
Published: February 2023

Distributed Bragg reflector (DBR) lead salt diode lasers represent a mid infrared light source with single mode emission, wide continuous mode tunability and a temperature stability better than conventional Fabry-Perot type devices. Lasers are available with cw operation above 77 K and a tuning range of 20 cm–1 which is completely covered. The laser configuration is shown in Fig. 1.
Juvenile Atlantic sea scallop, Placopecten magellanicus, energetic response to increased carbon dioxide and temperature changes
Authors: Pousse Emilien , Poach Matthew E. , Redman Dylan H. , Sennefelder George , Hubbard William , Osborne Kristin , Munroe Daphne , Hart Deborah , Hennen Daniel , Dixon Mark S. , Li Yaqin , Milke Lisa M. , Wikfors Gary H. , Meseck Shannon L.
Published: February 2023

This study assessed the energy budget for juvenile Atlantic Sea Scallop,Placopecten magellanicus, during a natural drop in temperature (15.6°C to 5.8°C) over an 8-week time period during the fall at three different enrichment levels of carbon dioxide (CO2). Every 2 weeks, individuals were sampled for ecophysiological measurements of feeding activity, respiration rate (RR) and excretion rate (ER) to enable the calculation of scope for growth (SFG) and atomic oxygen:nitrogen ratios (O:N). In addition, 36 individuals per treatment were removed for shell height, dry tissue weight (DTW) and dry shell weight (DSW). We found a significant decrease in feeding rates as CO2increased. Those rates also were significantly affected by temperature, with highest feeding at 9.4°C. No significant CO2effect was observed for catabolic energy processes (RR and ER); however, these rates did increase significantly with temperature. The O:N ratio was not significantly affected by CO2, but was significantly affected by temperature. There was a significant interaction between CO2and temperature for ER and the O:N ratio, with low CO2levels resulting in a U-shaped response that was not sustained as CO2levels increased. This suggests that the independent effects of CO2and temperature observed at low levels are different once a CO2threshold is reached. Additionally, there were significant differences in growth estimators (shell height and DSW), with the best growth occurring at the lowest CO2level. In contrast to temperature variations that induced a trade-off response in energy acquisition and expenditure, results from this research support the hypothesis that sea scallops have a limited ability to alter physiological processes to compensate for increasing CO2.
Interventions to reduce deaths in people living with HIV admitted to hospital in low- and middle-income countries: A systematic review
Authors: Burke Rachael M. , Twabi Hussein H. , Johnston Cheryl , Nliwasa Marriott , Gupta-Wright Ankur , Fielding Katherine , Ford Nathan , MacPherson Peter , Corbett Elizabeth L.
Published: February 2023

People living with HIV (PLHIV) admitted to hospital have a high risk of death. We systematically appraised evidence for interventions to reduce mortality among hospitalised PLHIV in low- and middle-income countries (LMICs). Using a broad search strategy with terms for HIV, hospitals, and clinical trials, we searched for reports published between 1 Jan 2003 and 23 August 2021. Studies of interventions among adult HIV positive inpatients in LMICs were included if there was a comparator group and death was an outcome. We excluded studies restricted only to inpatients with a specific diagnosis (e.g. cryptococcal meningitis). Of 19,970 unique studies identified in search, ten were eligible for inclusion with 7,531 participants in total: nine randomised trials, and one before-after study. Three trials investigated systematic screening for tuberculosis; two showed survival benefit for urine TB screening vs. no urine screening, and one which compared Xpert MTB/RIF versus smear microscopy showed no difference in survival. One before-after study implemented 2007 WHO guidelines to improve management of smear negative tuberculosis in severely ill PLHIV, and showed survival benefit but with high risk of bias. Two trials evaluated complex interventions aimed at overcoming barriers to ART initiation in newly diagnosed PLHIV, one of which showed survival benefit and the other no difference. Two small trials evaluated early inpatient ART start, with no difference in survival. Two trials investigated protocol-driven fluid resuscitation for emergency-room attendees meeting case-definitions for sepsis, and showed increased mortality with use of a protocol for fluid administration. In conclusion, ten studies published since 2003 investigated interventions that aimed to reduce mortality in hospitalised adults with HIV, and weren’t restricted to people with a defined disease diagnosis. Inpatient trials of diagnostics, therapeutics or a package of interventions to reduce mortality should be a research priority.

Trial registration: PROSPERO Number: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019150341.
Progestogens for maintenance tocolysis in symptomatic women. A systematic review and meta-analysis
Authors: Ferrari Francesca , Minozzi Silvia , Basile Laura , Chiossi Giuseppe , Facchinetti Fabio
Published: February 2023

Objective

Prevention of preterm birth (PTB) with progestogens after an episode of threatened preterm labour is still controversial. As different progestogens have distinct molecular structures and biological effects, we conducted a systematic review and pairwise meta-analysis to investigate the individual role played by 17-alpha-hydroxyprogesterone caproate (17-HP), vaginal progesterone (Vaginal P) and oral progesterone (Oral P).

Methods

The search was performed in MEDLINE, ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials (CENTRAL) up to 31 October 2021. Published RCTs comparing progestogens to placebo or no treatment for maintenance tocolysis were considered. We included women with singleton gestations, excluding quasi-randomized trials, studies on women with preterm premature rupture of membrane, or receiving maintenance tocolysis with other drugs. Primary outcomes were preterm birth (PTB) < 37 weeks’ and < 34 weeks’. We assessed risk of bias and evaluated certainty of evidence with the GRADE approach.

Results

Seventeen RCTs including 2152 women with singleton gestations were included. Twelve studies tested vaginal P, five 17-HP, and only 1 oral P. PTB < 34 weeks’ did not differ among women receiving vaginal P (RR 1.21, 95%CI 0.91 to 1.61, 1077 participants, moderate certainty of evidence), or oral P (RR 0.89, 95%CI 0.38 to 2.10, 90 participants, low certainty of evidence) as opposed to placebo. Instead, 17-HP significantly reduced the outcome (RR 0.72, 95% CI 0.54 to 0.95, 450 participants, moderate certainty of evidence). PTB < 37 weeks’ did not differ among women receiving vaginal P (RR 0.95, 95%CI 0.72 to 1.26, 8 studies, 1231 participants, moderate certainty of evidence) or 17-HP (RR 0.86, 95%CI 0.60 to 1.21, 450 participants, low certainty of evidence) when compared to placebo/no treatment. Instead, oral P significantly reduced the outcome (RR 0.58, 95% CI 0.36 to 0.93, 90 participants, low certainty of evidence).

Conclusions

With a moderate certainty of evidence, 17-HP prevents PTB < 34 weeks’ gestation among women that remained undelivered after an episode of threatened preterm labour. However, data are insufficient to generate recommendations in clinical practice. In the same women, both 17-HP and vaginal P are ineffective in the prevention of PTB < 37 weeks’.
Meta-analysis on the effects of moderate-intensity exercise intervention on executive functioning in children
Authors: Wang Haixia , Yang Yifei , Xu Jinfu , Niu Lin , Zhang Yue , Shi JingMei , Shen Lin
Published: February 2023

Objective

We evaluated the effect of moderate-intensity exercise intervention in children and summarized the optimal exercise intervention program.

Methods

Five significant databases, namely, Web of Science, PubMed, and China National Knowledge Infrastructure, were searched, and the literature was screened strictly according to the inclusion and exclusion criteria and analyzed using Stata 15.1 software.

Results

There were 25 studies from 22 articles, with a total of 2118 subjects included in the results. According to the meta-analysis, exercise intervention effectively improved children’s working memory [SMD = -1.05, 95% CI (-1.26, -0.84)] and cognitive flexibility [SMD = -0.86, 95% CI (-1.04, -0.69)], with a minor improvement in inhibitory control [SMD = -0.55, 95% CI (-0.68, -0.42)].

Conclusion

a) Improvements in children’s working memory and cognitive flexibility by moderate-intensity exercise interventions reached large effect sizes, and improvements in inhibitory control obtained moderate effect sizes. b) Better improvement in working memory for children aged 10 to 12 years than for children aged 6 to 9 years and better cognitive flexibility for children aged 6 to 9 years than for children aged 10 to 12 years. c) Exercise intervention programs lasting 8 to 12 weeks, 3 to 4 times/week, and 30 min/time are most effective in improving executive function in children.
Lower infant mortality, higher household size, and more access to contraception reduce fertility in low- and middle-income nations
Authors: Bradshaw Corey J. A. , Perry Claire , Judge Melinda A. , Saraswati Chitra M. , Heyworth Jane , Le Souëf Peter N.
Published: February 2023

Although average contraceptive use has increased globally in recent decades, an estimated 222 million (26%) of women of child-bearing age worldwide face an unmet need for family planning—defined as a discrepancy between fertility preferences and contraception practice, or failing to translate desires to avoid pregnancy into preventative behaviours and practices. While many studies have reported relationships between availability/quality of contraception and family planning, infant mortality, and fertility, these relationships have not been evaluated quantitatively across a broad range of low- and middle-income countries. Using publicly available data from 64 low- and middle-income countries, we collated test and control variables in six themes: (i) availability of family planning, (ii) quality of family planning, (iii) female education, (iv) religion, (v) mortality, and (vi) socio-economic conditions. We predicted that higher nation-level availability/quality of family-planning services and female education reduce average fertility, whereas higher infant mortality, greater household size (a proxy for population density), and religious adherence increase it. Given the sample size, we first constructed general linear models to test for relationships between fertility and the variables from each theme, from which we retained those with the highest explanatory power within a final general linear model set to determine the partial correlation of dominant test variables. We also applied boosted regression trees, generalised least-squares models, and generalised linear mixed-effects models to account for non-linearity and spatial autocorrelation. On average among all countries, we found the strongest associations between fertility and infant mortality, household size, and access to any form of contraception. Higher infant mortality and household size increased fertility, whereas greater access to any form of contraception decreased fertility. Female education, home visitations by health workers, quality of family planning, and religious adherence all had weak, if any, explanatory power. Our models suggest that decreasing infant mortality, ensuring sufficient housing to reduce household size, and increasing access to contraception will have the greatest effect on decreasing global fertility. We thus provide new evidence that progressing the United Nation’s Sustainable Development Goals for reducing infant mortality can be accelerated by increasing access to family planning.
A high latitude Gondwanan species of the Late Devonian tristichopterid Hyneria (Osteichthyes: Sarcopterygii)
Authors: Gess Robert W. , Ahlberg Per E.
Published: February 2023

We describe the largest bony fish in the Late Devonian (late Famennian) fossil assemblage from Waterloo Farm near Makhanda/Grahamstown, South Africa. It is a giant member of the extinct clade Tristichopteridae (Sarcopterygii: Tetrapodomorpha) and most closely resembles Hyneria lindae from the late Famennian Catskill Formation of Pennsylvania, USA. Notwithstanding the overall similarity, it can be distinguished from H. lindae on a number of morphological points and is accordingly described as a new species, H. udlezinye sp. nov. The preserved material comprises most of the dermal skull, lower jaw, gill cover and shoulder girdle. The cranial endoskeleton appears to have been unossified and is not preserved, apart from a fragment of the hyoid arch adhering to a subopercular, but the postcranial endoskeleton is represented by an ulnare, some semi-articulated neural spines, and the basal plate of a median fin. The discovery of H. udlezinye shows that Hyneria is a cosmopolitan genus extending into the high latitudes of Gondwana, not a Euramerican endemic. It supports the contention that the derived clade of giant tristichopterids, which alongside Hyneria includes such genera as Eusthenodon, Edenopteron and Mandageria, originated in Gondwana.
Two is better than one: Apologies from two robots are preferred
Authors: Okada Yuka , Kimoto Mitsuhiko , Iio Takamasa , Shimohara Katsunori , Shiomi Masahiro
Published: February 2023

Although the capabilities of service robots are increasing, avoiding any mistakes is difficult. Therefore, strategies for mitigating mistakes, such as apology behavior designs, are essential for service robots. Past studies reported that costly apology is perceived as more sincere than non-costly ones and more acceptable. To increase the apology cost in robot service situations, we thought that using multiple robots would increase the perceived costs in the of financial, physical, and time costs. Therefore, we focused on the number of robots who apologize for their mistakes as well as their individual, specific roles and behaviors during such apologies. We investigated the differences in perceived impressions toward apologies from two robots (the main robot that makes a mistake and apologizes and a sub-robot that also apologizes) and an apology from just one robot (only the main robot) through a web survey with 168 valid participants. The experiment results showed that the participants significantly preferred and positively evaluated apologies from two robots more than one robot in the context of forgiveness, negative word-of-mouth, trust, and intention to use. We also conducted another web survey with 430 valid participants to investigate the effects of different roles for the sub-robot: apologize-only, cleaning-up-only, and both actions. The experimental results showed that the participants significantly preferred and positively evaluated both actions in the context of forgiveness and reliable/competent perspectives.
Evaluating the feasibility and efficacy of a home-based combined high intensity interval and moderate intensity training program for increasing physical activity among low-active adults: A randomized pilot trial
Authors: Lewis Beth A. , Schuver Katie , Dunsiger Shira
Published: February 2023

Background

High intensity interval training (HIIT), which includes short bursts of high-intensity physical activity (PA) followed by recovery, can increase PA by addressing time barriers and improving PA enjoyment. The purpose of this pilot study was to examine the feasibility and preliminary efficacy of a home-based HIIT intervention on PA.

Methods

Low active adults (n = 47) were randomly assigned to a home-based HIIT intervention or wait-list control lasting 12 weeks. Participants in the HIIT intervention received motivational phone sessions based on Self-Determination Theory and accessed a website that included workout instructions and videos demonstrating proper form.

Results

The HIIT intervention appears feasible based on retention, recruitment, adherence to the counseling sessions, follow-up rates, and the consumer satisfaction survey. HIIT participants reported more minutes of vigorous intensity PA at six weeks relative to control (no differences at 12 weeks). HIIT participants reported higher levels of self-efficacy for PA, enjoyment of PA, outcome expectations related to PA, and positive engagement with PA than the control.

Conclusions

This study provides evidence for feasibility and possible efficacy of a home-based HIIT intervention for vigorous intensity PA; however, additional studies are needed with larger samples sizes to confirm efficacy of home-based HIIT interventions.

Trial registration

Clinical Trials Number: NCT03479177.
Trends of repeated emergency department visits among adolescents and young adults for substance use: A repeated cross-sectional study
Authors: Kim Soyeon , Weekes John , Young Matthew M. , Adams Nicole , Kolla Nathan J.
Published: February 2023

Emergency Department (ED) visits for substance-related concerns among young people have been increasing in recent years. Understanding the factors related to repeated ED visits (two or more ED visits per year) for substance use concerns among young people is critical to developing a more efficient mental healthcare system that does not overburden ED and that provides efficient care for substance use patients. This study examined trends of substance use-related ED visits and factors related to repeated ED visits (two or more ED visits per year, in comparison to one ED visit per year) among adolescents and young adults (aged 13 to 25 years) in the province of Ontario, Canada. Binary logistic regression models were conducted to examine associations between hospital-related factors (hospital size, urbanicity, triage level, ED wait time) and visit status (2+ vs 1 ED visit/year), controlling for patient characteristics (age/sex). A population-based, repeated cross-sectional data over a 10-year period (2008, 2013, and 2018) was used. The proportion of substance use-related repeated ED visits significantly and consistently increased in the year 2013 and 2018 compared to 2008 (2008 = 12.52%, 2013 = 19.47%, 2018 = 20.19%). Young adult, male, medium-sized hospital, urban location, wait times longer than 6 hours, and symptom severity was associated with increased numbers of repeated ED visits. Furthermore, polysubstance use, opioid use, cocaine use, and stimulant use were strongly associated with repeated ED visits compared with the use of substances such as cannabis, alcohol and sedatives. Current findings suggest that repeated ED visits for substance use concerns could be reduced by policies that reinforce evenly distributed mental health and addiction treatment services across the provinces in rural areas and small hospitals. These services should put special efforts into developing specific (e.g., withdrawal/treatment) programming for substance-related repeated ED patients. The services should target young people using multiple psychoactive substances, stimulants and cocaine.