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Background & aims: Echolalia, the repetition of one's or others' utterances, is a behavior present in typical development, autism spectrum disorder, aphasias, Tourette's, and other clinical groups. Despite the broad range of conditions in which echolalia can occur, it is considered primarily through a disorder-specific lens, which limits a full understanding of the behavior. Method: Empirical and review papers on echolalia across disciplines and etiologies were considered for this narrative review. Literatures were condensed into three primary sections, including echolalia presentations, neural mechanisms, and treatment approaches. Main contribution: Echolalia, commonly observed in autism and other developmental conditions, is assessed, observed, and treated in a siloed fashion, which reduces our collective knowledge of this communication difference. Echolalia should be considered as a developmental, transdiagnostic, and communicative phenomenon. Echolalia is commonly considered as a communicative behavior, but little is known about its neural etiologies or efficacious treatments. Conclusions: This review is the first to synthesize echolalia from a transdiagnostic perspective, which allows for the direct comparisons across and within clinical groups to inform assessment, treatment, conceptualization, and research recommendations. Implications: Considering echolalia transdiagnostically highlights the lack of consensus on operationalization and measurement across and within disorders. Clinical and research future directions need to prioritize consistent definitions of echolalia, which can be used to derive accurate prevalence estimates. Echolalia should be considered as a communication strategy, used similarly across developmental and clinical groups, with recommended strategies of shaping to increase its effectiveness. [ABSTRACT FROM AUTHOR]

Aluminum gallium arsenide-on-insulator (AlGaAsOI) exhibits large χ 2 and χ 3 optical nonlinearities, a wide tunable bandgap, low waveguide propagation loss, and a large thermo-optic coefficient, making it an exciting platform for integrated quantum photonics. With ultrabright sources of quantum light established in AlGaAsOI, the next step is to develop the critical building blocks for chip-scale quantum photonic circuits. Here we expand the quantum photonic toolbox for AlGaAsOI by demonstrating edge couplers, 3 dB splitters, tunable interferometers, and waveguide crossings with performance comparable to or exceeding silicon and silicon-nitride quantum photonic platforms. As a demonstration, we de-multiplex photonic qubits through an unbalanced interferometer, paving the route toward ultra-efficient and high-rate chip-scale demonstrations of photonic quantum computation and information applications. [ABSTRACT FROM AUTHOR]

Background: Neurogenesis in the hippocampus endures across the lifespan but is particularly prolific during the first postnatal week in the developing rodent brain. The majority of new born neurons are in the dentate gyrus (DG). The number of new neurons born during the first postnatal week in the DG of male rat pups is about double the number in females. In other systems, the rate of cell proliferation is controlled by epigenetic modifications in stem cells. We, therefore, explored the potential impact of DNA methylation and histone acetylation on cell genesis in the developing DG of male and female rats. Methods: Cell genesis was assessed by quantification of BrdU + cells in the DG of neonatal rats following injections on multiple days. Methylation and acetylation were manipulated pharmacologically by injection of well vetted drugs. DNA methylation, histone acetylation and associated enzyme activity were measured using commercially available colorimetric assays. mRNA was quantified by PCR. Multiple group comparisons were made by one- or two-way ANOVA followed by post-hoc tests controlling for multiple comparisons. Two groups were compared by t test. Results: We found higher levels of DNA methylation in male DG and treatment with the DNA methylating enzyme inhibitor zebularine reduced the methylation and correspondingly reduced cell genesis. The same treatment had no impact on either measure in females. By contrast, treatment with a histone deacetylase inhibitor, trichostatin-A, increased histone acetylation in the DG of both sexes but increased cell genesis only in females. Females had higher baseline histone deacetylase activity and greater inhibition in response to trichostatin-A treatment. The mRNA levels of the proproliferative gene brain-derived neurotrophic factor were greater in males and reduced by inhibiting both DNA methylation and histone deacetylation only in males. Conclusions: These data reveal a sexually dimorphic epigenetically based regulation of neurogenesis in the DG but the mechanisms establishing the distinct regulation involving DNA methylation in males and histone acetylation in females is unknown. Highlights: Neurogenesis in the dentate gyrus peaks in the early postnatal period and in the laboratory rat is significantly greater in males than females. Here we report divergent regulation of cell genesis in the neonatal dentate gyrus. DNA methylation is a critical regulator of the higher rates of proliferation in males. Conversely, histone acetylation is essential for cell genesis in females. [ABSTRACT FROM AUTHOR]

Silicon photonics is a truly disruptive technology that has grown tremendously in the past two decades. It has now become a recognized leader in the next generation of consumer products. These future products require realizing complex optical functionalities—chief among which is an on-chip laser. Low noise and wide tuning range are the two main important characteristics of an on-chip laser as the components required to achieve these characteristics constitute the bulk of current benchtop lasers. In this paper, we review the impact of silicon photonic chips on dramatically improving the tuning range and the noise characteristics. Two different types of technologies are reviewed— heterogeneous integration by wafer bonding and hybrid integration by butt-coupling. We cover the two most important wavelength bands for optical communications—O-band for data communication applications and C-band for telecom applications. [ABSTRACT FROM AUTHOR]

Advances in thin film growth technology have enabled the selective engineering of material properties to improve the thermoelectric figure of merit and thus the efficiency of energy conversion devices. Precise characterization at the operational temperature of novel thermoelectric materials is crucial to evaluate their performance and optimize their behavior. However, measurements on thin film devices are subject to complications from the growth substrate, non-ideal contacts, and other thermal and electrical parasitic effects. In this manuscript, we determine the cross-plane thermoelectric material properties in a single measurement of a 25 μm InGaAs thin film with embedded ErAs (0.2%) nanoparticles using the bipolar transient Harman method in conjunction with thermoreflectance thermal imaging at temperatures up to 550K. This approach eliminates discrepancies and potential device degradation from the multiple measurements necessary to obtain individual material parameters. In addition, we present a strategy for optimizing device geometry to mitigate the effect of both electrical and thermal parasitics during the measurement. Finite element method simulations are utilized to analyze non-uniform current and temperature distributions over the device area as well as the three dimensional current path for accurate extraction of material properties from the thermal images. Results are compared with independent in-plane and 3ω measurements of thermoelectric material properties for the same material composition and are found to match reasonably well; the obtained figure of merit matches within 15% at room and elevated temperatures. [ABSTRACT FROM AUTHOR]

We have investigated the possibilities to quantify how much stars move in the Milky Way disc due to diffuse processes (blurring) and due to influences from spiral arms and the bar (churning). We assume that the formation radius of a star can be inferred if we know its elemental abundances and age and the metallicity profile of the interstellar medium at the time of the star's formation. We use data for red giant branch stars from APOGEE DR14, parallaxes from Gaia , and stellar ages based on the C and N abundances. In our sample, we find that half of the stars have experienced some sort of radial migration, 10 per cent likely have suffered only from churning, and a modest 5–7 per cent have never experienced either churning or blurring making them ideal tracers of the original properties of the cool stellar disc. To arrive at these numbers, we imposed the requirement that the stars that are considered to be churned have highly circular orbits. If instead we require that the star has moved away from its formation position and at the same time that its Galactocentric radius at formation did not fall between the apo- and pericentre of its orbit today, we find that about half of the stars have undergone a radial migration. We have thus shown that it is possible to put up a framework to quantify churning and blurring. Future work includes investigations of how selection effects influence the results. [ABSTRACT FROM AUTHOR]

Rare-earth impurities in III-V semiconductors are known to self-assemble into semimetallic nanoparticles which have been shown to reduce lattice thermal conductivity without harming electronic properties. Here, we show that adjusting the band alignment between ErAs and In0.53Ga0.47-XAlXAs allows energy-dependent scattering of carriers that can be used to increase thermoelectric power factor. Films of various Al concentrations were grown by molecular beam epitaxy, and thermoelectric properties were characterized. We observe concurrent increases in electrical conductivity and Seebeck coefficient with increasing temperatures, demonstrating energy-dependent scattering. We report the first simultaneous power factor enhancement and thermal conductivity reduction in a nanoparticle-based system, resulting in a high figure of merit, ZT=1.33 at 800 K. [ABSTRACT FROM AUTHOR]

The structure and composition of the interface of directly bonded GaAs and InP (001) wafers has been studied with various techniques in electron microscopy. For each interface three different dislocation networks have been identified and analyzed. They have been confirmed to accommodate the lattice mismatch, the tilt misfit between the two wafers, and the thermal misfit, respectively. Interdiffusion of both group-III and group-V elements takes place. Indium diffusion is enhanced by the Zn dopant and its segregation. The "cavities" at the interface, reported in the literature, have been found to be associated with indium depletion. In the case of inadequate surface preparation prior to bonding an amorphous layer of native oxide(s) forms at the interface. The actual bonding temperature T[sub b] at which the atomic bonds construct locally across the two surfaces of the wafers is lower than the annealing temperature employed in the present experiments. It is therefore suggested that a better interface may be achieved by improving the preparation of the surfaces of the wafers with appropriate chemicals and by bonding the wafers at a lower temperature. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

In our cohort, which includes pts who would not have been eligible for the pivotal ECHELON-1 trial, BV discontinuation rates were higher than previously reported, but 2-year outcomes remain comparable; discontinuation of BV was not associated with inferior PFS. B Introduction: b BV in combination with doxorubicin, vinblastine, and dacarbazine (AVD) is the new standard of care for newly diagnosed stage III/IV cHL. Brentuximab vedotin (BV) + AVD for newly diagnosed classic Hodgkin lymphoma (cHL): incidence and management of peripheral neuropathy (PN) in a multi-institution cohort. [Extracted from the article]

This work investigates the performance of 1.3-μm quantum dot lasers epitaxially grown on silicon under optical feedback sensitivity with different temperature and doping profiles. Experiments show that these quantum dot lasers exhibit a very high degree of resistance to both incoherent and coherent optical feedbacks. 10 Gbps penalty-free transmissions are also unveiled under external modulation and at different temperatures. The paper draws attention on quantum dot lasers with p-doping that exhibit a better thermal resistance, a lower linewidth enhancement factor, a higher critical feedback level, and a better spectral stability with less intensity noise. Together, these properties make epitaxial quantum dot lasers with p-doping more promising for isolator-free and Peltier-free applications, which are meaningful for future high-speed photonic integrated circuits. [ABSTRACT FROM AUTHOR]

This work investigates the effect of the polarization anisotropy on the linewidth enhancement factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small linewidth enhancement factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures. [ABSTRACT FROM AUTHOR]

Analyzes the various properties of the fused interface between gallium arsenide and indium phosphide. Description of the water fusing process; Information on the defect charactertization; Impact of dislocations observed by transmission electron microscopy on the electrical properties of fused gallium arsenide/indium-phosphorus.

We present the results of time-resolved luminescence studies of poly[2-methoxy, 5-(2’-ethyl-hexyloxy)-p-phenylene-vinylene] (MEH-PPV), as a pure film, in solution, in a gel formed by a network of ultrahigh molecular weight polyethylene (UHMW-PE), and in a blend with UHMW-PE. The luminescence has a characteristic lifetime of 200–300 ps at room temperature, increasing to 500–700 ps when the materials are cooled to 80 K; the decay time is approximately the same for all the physical forms of the material (solution, film, gel, blend). The relatively short lifetimes, compared to intrinsic values calculated from absorption and emission spectra, and the observed temperature dependence indicate that the luminescence decay is quenched by nonradiative processes. The time decay of the photoluminescence deviates from a single exponential for most forms of the MEH-PPV. Best fits to stretched exponential and double exponential expressions are presented. Steady state photoluminescence spectra and integrated luminescence vs pump intensity data are presented in order to establish which of the possible mechanisms are most important. [ABSTRACT FROM AUTHOR]

The objective of this study was to detect Streptococcus equi subspecies equi (S. equi) (Lactobacillales: Streptococcaceae) using quantitative polymerase chain reaction (qPCR) in flies collected from a farm with a documented outbreak of strangles. A total of 1856 face flies [Musca autumnalis (Diptera: Muscidae)] were collected using conventional fly traps. The flies were processed for nucleic acid purification and tested for the presence of S. equi by qPCR. A total of 10/1856 flies (0.54%) tested qPCR‐positive for S. equi. The results may implicate the presence of face flies as a risk factor for the transmission of S. equi and highlight the need to institute proper husbandry measures, biosecurity protocols and fly control in order to reduce the potential for infection in at‐risk horses. [ABSTRACT FROM AUTHOR]

Coccidioides immitis and Coccidioides posadasii are soil fungi endemic to desert regions of the southwestern United States, and the causative agents of valley fever, or coccidioidomycosis. Studies have shown that the distribution of Coccidioides in soils is sporadic and cannot be explained by soil characteristics alone, suggesting that biotic and other abiotic factors should be examined. However, tools to reliably and robustly screen the large number of soils needed to investigate these potential associations have not been available. Thus, we developed a real-time polymerase chain reaction (PCR) assay for testing environmental samples by modifying CocciDx, an assay validated for testing clinical specimens to facilitate coccidioidomycosis diagnosis. For this study, we collected soil samples from previously established locations of C. posadasii in Arizona and new locations in fall 2013 and spring 2014, and screened the extracted DNA with the new assay known as CocciEnv. To verify the presence of Coccidioides in soil using an alternate method, we employed next generation amplicon sequencing targeting the ITS2 region. Results show our modified assay, CocciEnv, is a rapid and robust method for detecting Coccidioides DNA in complex environmental samples. The ability to test a large number of soils for the presence of Coccidioides is a much-needed tool in the understanding of the ecology of the organism and epidemiology of the disease and will greatly improve our understanding of this human pathogen. [ABSTRACT FROM AUTHOR]

We demonstrate 10 Gbit/s operation of InAs/InGaAs quantum dot (QD) p-i-n photodiodes (PDs) grown on on-axis (001) GaP/Si substrates. A 3.0 × 50 μm2 QD PD shows a small dark current of 0.2 nA at a bias voltage of −3 V, which corresponds to a dark current density of 0.13 mA/cm2. This low-dark current characteristic obtained from a narrow-stripe device indicates that sidewall and threading dislocations have small effects on the dark current. The 3 dB bandwidth was 5.5 GHz at a bias voltage of −5 V. Large signal measurement with non-return-to-zero signals shows 10 Gbit/s eye opening. [ABSTRACT FROM AUTHOR]

This work reports on the ultra-low linewidth enhancement factor (αH-factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the linewidth enhancement factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources. [ABSTRACT FROM AUTHOR]

Fully integrated photonic microwave/millimeter-wave (MMW) tracking generators, which include wavelength-tunable lasers, distributed feedback lasers, phase modulators, and high-speed photodiodes (PDs), are demonstrated on the heterogeneous integrated III–V-on-Si photonic platform. Two on-chip lasers are locked by an external optical phase-locked loop (OPLL), and the two-tone radio-frequency (RF) signals from the on-chip fast PDs can be photonically generated through the heterodyne-beating process between the wavelength-tunable laser and the OPLL output. Furthermore, the frequency spacing between such two-tone RF signals can be tracked by the oscillation frequency in the OPLL with a wide tunability (near dc to 10 GHz). Fast and truly continuous scanning of photo-generated MMW signals thus becomes feasible by simultaneously tuning the OPLL and the central wavelength of the tunable laser in the demonstrated photonic integrated circuit. [ABSTRACT FROM AUTHOR]

Describes the properties of 1.5-μm double-channel planar buried heterostructure (DC-PBH) laser fabrication. Features of a gallium-indium-arsenic-phosphorous/indium phosphide DC-PBH laser; Frequency dependence of the relative intensity noise; Measurement of temperatures.

A multi-wavelength, high contrast contact radiography system has been developed to characterize density variations in ultra-low density aerogel foams. These foams are used to generate a ramped pressure drive in materials strength experiments at the National Ignition Facility and require precision characterization in order to reduce errors in measurements. The system was used to characterize density variations in carbon and silicon based aerogels to ∼10.3% accuracy with ∼30 μm spatial resolution. The system description, performance, and measurement results collected using a 17.8 mg/cc carbon based JX-6 (C20H30) aerogel are discussed in this manuscript. [ABSTRACT FROM AUTHOR]

Objectives: To determine whether gut focused behavioural treatment (biofeedback) is a useful therapy in multiple sclerosis patients referred for constipation, incontinence, or a combination of these symptoms. Most patients with multiple sclerosis complain of constipation, faecal incontinence, or a combination of the two. Patients rate these bowel symptoms as having a major impact on their life. Until now the management of these problems has been empirical, with a lack of evaluated therapeutic regimes.Methods: Thirteen patients (eight women, median age 38 years, median duration of multiple sclerosis 10 years) complaining of constipation, with or without faecal incontinence underwent a median of four sessions of behavioural treatment. Anorectal physiological tests were performed before therapy. Impairment and disability were rated with the Kurtzke score and the Cambridge multiple sclerosis basic score (CAMBS). Patients were contacted a median of 14 months after completion of treatment.Results: A beneficial effect was attributed to biofeedback in five patients. Mild to moderate disability, quiescent and non-relapsing disease, and absence of progression of multiple sclerosis over the year before biofeedback were predictive of symptom improvement. No physiological test predicted the response to therapy.Conclusion: Biofeedback retraining is an effective treatment in some patients with multiple sclerosis complaining of constipation or faecal incontinence. A response is more likely in patients with limited disability and a non-progressive disease course. [ABSTRACT FROM AUTHOR]

There is considerable interest in determining whether hypergravity can be used as a countermeasure for microgravity-induced bone loss. This study was conducted on 20 immature male rats in order to investigate possible elastic adaptations of cortical bone in rapidly growing rats exposed to chronic hypergravity. Ten rats were continuously centrifuged for 14 days at twice gravitational acceleration (2G) on a 12.75 foot radius centrifuge and 10 rats concurrently acted as stationary controls. The effect of hypergravity on the elastic characteristics of cortical bone was quantified via ultrasonic wave propagation. Propagation velocities of longitudinal and shear waves were measured through cubic cortical specimens from the posterior femoral diaphyses. Density was measured with an Archimedes' technique. The orthotropic elastic properties were calculated and used to compare the difference between groups. Results showed an average increase in both the Young's moduli (Eii, + 2.2%) and shear moduli (Gij, + 4.3%) with a statistically significant increase only in G12 (+15.7%, P = 0.046). The ratio of transverse to axial strain (Poisson's ratio, nuij) demonstrated statistically significant changes in nu12, nu21, nu13, and nu31 (P < 0.05). These findings suggest that although slight elastic changes were incurred via a hypergravity environment, the treatment level or duration in this study do not dramatically perturb the normal elastic behavior of cortical bone and that dramatic biomechanical differences noted in previous studies were due more to structural changes than material elasticity changes. Hypergravity applied post facto to a microgravity environment would offer further illucidation of this method as treatment for a degenerative spaceflight experience. [ABSTRACT FROM AUTHOR]