Poor Coherence Research Articles

Observation of a 1.979-eV spectral line of a germanium-related color center in microdiamonds and nanodiamonds

Color centers in diamond are considered as a platform for quantum computing and communications, biomedical markers, and nanosensors. Negatively charged split-vacancy centers have outstanding properties due to bright and almost monochromatic luminescence, but they have poor spin coherence and relaxation times. This drawback is believed to be absent in the neutral charge state of the defects. So far only the neutral silicon-vacancy center has been observed in luminescence and absorption spectra. Here we report the observation of its germanium-based analog in luminescence spectra with the zero-phonon line (ZPL) at 1.979 eV in samples containing negatively charged ${\mathrm{GeV}}^{\ensuremath{-}}$ centers. The relationship between the center and Ge dopant is unambiguously confirmed by studies of $^{12}\mathrm{C}$ diamonds containing $^{70}\mathrm{Ge}$, $^{73}\mathrm{Ge}$, or $^{76}\mathrm{Ge}$ isotopes. The intensity ratio of the ZPL of these centers varies with the crystal size, and the intensity of the ${\mathrm{GeV}}^{0}$ centers reaches its maximum in samples 150 nm in size. In the vibronic sideband of this center the local vibrational mode with an energy of 23 meV was identified. The density functional theory calculations yield a ZPL energy value of the ${\mathrm{GeV}}^{0}$ center which is 150 meV higher than the experimentally observed one and matches the values of its relaxational energy as well as the local phonon mode frequency.

Screening for Latent Tuberculosis in Children With Immune-mediated Inflammatory Diseases Treated With Anti-tumor Necrosis Factor Therapy: Comparison of Tuberculin Skin and T-SPOT Tuberculosis Tests.

This study aims to analyze the coherence between T-SPOT tuberculosis test (T-SPOT.TB) and tuberculin skin test (TST) with different cut-off values in screening latent tuberculosis infection (LTBI) both prior to and at the sixth month of anti-tumor necrosis factor (anti-TNF) treatment. This prospective multicentric study included 57 children (34 girls, 23 boys, mean age 12.4±3.9 years; range, 6 to 18 years) diagnosed with immune-mediated inflammatory diseases (IMIDs) evaluated with TST and T-SPOT.TB for screening LTBI both prior to and at the sixth month of treatment with anti-TNF agents. Coherence between two tests was analyzed for TST cut-off values suggested by the local guidelines and also for different possible cut-off values of TST. Tuberculin skin test was positive (≥5 mm) in 28.1% (n=16) of patients in the screening prior to treatment and in 33.3% (n=19) at the sixth month of treatment. T-SPOT.TB test was positive in 8.8% (n=5) of patients both prior to and at the sixth month of treatment. Coherence between two tests was poor or fair when compared with all possible TST cut-off values both prior to and at the sixth month of anti-TNF therapy. Our results show poor coherence between T-SPOT.TB and TST for all possible cut-off values of TST. Thus, using both tests would be beneficial in screening LTBI until further studies bring new evidence on the subject.

Protecting Quantum Spin Coherence of Nanodiamonds in Living Cells

Due to its superior coherent and optical properties at room temperature, the nitrogen-vacancy (N-V ) center in diamond has become a promising quantum probe for nanoscale quantum sensing. However, the application of N-V containing nanodiamonds to quantum sensing suffers from their relatively poor spin coherence times. Here we demonstrate energy efficient protection of N-V spin coherence in nanodiamonds using concatenated continuous dynamical decoupling, which exhibits excellent performance with less stringent microwave power requirement. When applied to nanodiamonds in living cells we are able to extend the spin coherence time by an order of magnitude to the $T_1$-limit of up to $30\mu$s. Further analysis demonstrates concomitant improvements of sensing performance which shows that our results provide an important step towards in vivo quantum sensing using N-V centers in nanodiamond.

Analysis of an Ensemble of High-Resolution WRF Simulations for the Rapid Intensification of Super Typhoon Rammasun (2014)

Diagnostics are presented from an ensemble of high-resolution forecasts that differed markedly in their predictions of the rapid intensification (RI) of Typhoon Rammasun. We show that the basic difference stems from subtle differences in initializations of (a) 500–850-hPa environmental winds, and (b) midlevel moisture and ventilation. We then describe how these differences impact on the evolving convective organization, storm structure, and the timing of RI. As expected, ascent, diabatic heating and the secondary circulation near the inner-core are much stronger in the member that best forecasts the RI. The evolution of vortex cloudiness from this member is similar to the actual imagery, with the development of an inner cloud band wrapping inwards to form the eyewall. We present evidence that this structure, and hence the enhanced diabatic heating, is related to the tilt and associated dynamics of the developing inner-core in shear. For the most accurate ensemble member: (a) inhibition of ascent and a reduction in convection over the up-shear sector allow moistening of the boundary-layer air, which is transported to the down-shear sector to feed a developing convective asymmetry; (b) with minimal ventilation, undiluted clouds and moisture from the down-shear left quadrant are then wrapped inwards to the up-shear left quadrant to form the eyewall cloud; and (c) this process seems related to a critical down-shear tilt of the vortex from midlevels, and the vertical phase-locking of the circulation over up-shear quadrants. For the member that forecasts a much-delayed RI, these processes are inhibited by stronger vertical wind shear, initially resulting in poor vertical coherence of the circulation, lesser moisture and larger ventilation. Our analysis suggests that ensemble prediction is needed to account for the sensitivity of forecasts to a relatively narrow range of environmental wind shear, moisture and vortex inner-structure.

Compact CW Nd:YVO4/PPMgLN green laser

A compact and reliable linear-beam Nd:YVO4/PPMgLN green laser pumped by an edge-emitting laser diode array (24 separate emitters with an overall length of 480 μm and a gross power of 45 W at 807.1 nm) is achieved. The independent 24-edge-emitting array can achieve poor spatial coherence and effectively reduce laser speckle effect. In the air-cooled (water-cooled) condition, the maximum output power is 8.64 W (11.10 W), the optical-optical conversion efficiency is 24 % (25 %), and the power variation is less than 3 % (2 %) for 1 h (3 h).

Сферические радиальные базисные функции с метрикой Махаланобиса для отображения локальных особенностей поля

As we know the spherical functions are traditionally used in geodesy for modeling the gravitational field of the Earth. But the gravitational field is not stationary either in space or in time (but the latter is beyond the scope of this article) and can change quite strongly in various directions. By its nature, the spherical functions do not fully display the local features of the field. With this in mind it is advisable to use spatially localized basis functions. So it is convenient to divide the region under consideration into segments with a nearly stationary field. The complexity of the field in each segment can be characterized by means of an anisotropic matrix resulting from the covariance analysis of the field. If we approach the modeling in this way there can arise a problem of poor coherence of local models on segments’ borders. To solve the above mentioned problem it is proposed in this article to use new basis functions with Mahalanobis metric instead of the usual Euclidean distance. The Mahalanobis metric and the quadratic form generalizing this metric enables us to take into account the structure of the field when determining the distance between the points and to make the modeling process continuous.

Coherent control in the extreme ultraviolet and attosecond regime by synchrotron radiation

Quantum manipulation of populations and pathways in matter by light pulses, so-called coherent control, is currently one of the hottest research areas in optical physics and photochemistry. The forefront of coherent control research is moving rapidly into the regime of extreme ultraviolet wavelength and attosecond temporal resolution. This advance has been enabled by the development of high harmonic generation light sources driven by intense femtosecond laser pulses and by the advent of seeded free electron laser sources. Synchrotron radiation, which is usually illustrated as being of poor temporal coherence, hitherto has not been considered as a tool for coherent control. Here we show an approach based on synchrotron radiation to study coherent control in the extreme ultraviolet and attosecond regime. We demonstrate this capability by achieving wave-packet interferometry on Rydberg wave packets generated in helium atoms.

α-stable noise-induced coherence on a spatially extended Fitzhugh–Nagumo system

In this paper, we study the noise-induced temporal and spatial coherence in a spatially extended Fitzhugh–Nagumo (FHN) neuronal system. The system is modeled by a randomly connected small-world network, in which an -stable noise is imposed on the first neuron. We focus on the impact of additive temporally and spatially uncorrelated non-Gaussian -stable noise that determines the interactions amongst coupled FHN neurons. Using numerical simulations, we find that the system presents a typical coherence characteristic on temporal scale, while a decoherence characteristic on spatial scale. Then, the temporal and spatial coherence under the influences of -stable noises are studied, respectively. We find that has a significant impact on the temporal coherence but little significance on the spatial coherence. It shows that in contrast to Gaussian noise, -stable noises lead to poor temporal coherence.

Overlap of obsessive–compulsive personality disorder and autism spectrum disorder traits among OCD outpatients: an exploratory study

Background: Whereas the phenomenology of obsessive–compulsive personality disorder (OCPD) shows similarities to that of obsessive compulsive and related disorders (OCRDs) as well as with autism spectrum disorder (ASD), the relationship between these disorders is poorly understood.Aims: Within a clinical sample, we aimed to investigate the distribution of OCD, OCPD and ASD symptoms and traits and their interrelationship, as well as to evaluate insight and treatment refractoriness.Methods: Consecutive adult OCD outpatients were assessed for OCPD traits (Compulsive Personality Assessment Scale (CPAS)), OCD symptoms (Yale–Brown Obsessive Compulsive Scale (Y-BOCS)), ASD traits (Autism Spectrum Quotient (AQ)), insight (Brown Assessment of Beliefs Scale (BABS)) and treatment resistance (clinical records). Those scoring highly on the AQ underwent a diagnostic interview for ASD.Results: Sixty-seven consenting individuals completed the CPAS, BABS and AQ, and 65 completed the Y-BOCS. Twenty-four patients (35.8%) were diagnosed with OCPD. Patients with OCPD were less likely to be employed (p=.04). They demonstrated elevated AQ scores (p=.004) and rates of ASD diagnosis (54.2%) (p <.001). OCPD traits (CPAS) showed a highly significant correlation with ASD traits (AQ) (p<.001), and no association with Y-BOCS, BABS or treatment resistance.Conclusions: In an OCD cohort limited by small size, OCPD associated strongly with unemployment and ASD, with implications for diagnosis, treatment and outcome.KEY POINTSClinicians should exercise a high level of vigilance for OCPD and ASD in patients presenting with obsessive compulsive symptoms.The presence of OCPD may indicate a likelihood of disabling ASD traits, including cognitive inflexibility, poor central coherence and poor social communication.These neuropsychological factors may require separate clinical intervention strategies.

Compact Nd:YVO4/LBO 532.1 nm laser pumped by a multi-emitter laser diode

A linear-beam of Nd:YVO4/LBO green laser at 532.1 nm pumped by a 24-emitter (edge-emitting) laser diode is achieved. This independent 24-emitter pump system can obtain poor spatial coherence of the linear-beam, which can effectively diminish speckle noise effect. The green output power of 8.26 W is obtained at a pump power of 36 W with an optical-to-optical conversion efficiency of 22.9%. Compared with the other green laser pumped by fiber-coupled LD, this system is cheaper and compacter.

Implementing delayed umbilical cord clamping in Nepal-Delivery care staff's perceptions and attitudes towards changes in practice.

AimTo explore delivery care staff’s perceptions and attitudes towards changes in practice of umbilical cord clamping in order to identify work culture barriers and enablers for improved clinical practice and implementation of the new guidelines on cord clamping.MethodA purposive sampling strategy was used to include delivery staff at two major hospitals in Kathmandu, Nepal for focus group discussions. Key informant interviews were conducted with the ward in-charges and skilled birth attendant trainers at the respective hospitals. Data were analyzed using qualitative content analysis.ResultEight focus group discussions altogether with 34 delivery care staff working in the labor room and birthing units, and 12 key informant interviews with skilled birth attendant trainers/supervisors and ward in-charges from both hospitals participated in the study. Participants had positive attitudes towards delayed cord clamping as it was not perceived to be a difficult task and as they perceived it to be beneficial for mother and child. The “will to do good”, and a high level of trust both in the hierarchical system as well as in scientific evidence were identified as promoters of change. Several barriers were mentioned, such as maternal or fetal medical conditions and physical settings, as constraints to perform delayed cord clamping. They also mentioned difficulties in adopting new guidelines due to habitual practice, lack of formal training and poor coherence within the work team. In order to bring change to the practice, participants highlighted that officially approved national and institutional protocols and regular training are crucial.ConclusionDue to poor coherence within the health system and lack of national or institutional protocols, delivery staff has to rely on their own initiative to develop skills and are left to informal decision making, and are therefore hesitant to apply new routines. In order to change cord clamping practices to align with evidence and policies health-care staff needs to be better supported by the governance structures of the health system, with clear and approved guidelines made available and coherent training and support.

1.2 kW quasi-steady-state diamond Raman laser pumped by an M2 = 15 beam.

An external cavity diamond Raman laser with 1.2kW output power is demonstrated for durations 7 times longer than the thermal lens time constant. An 83% slope efficiency and a 53% optical-to-optical efficiency were obtained for conversion from a 1.06μm pump to the 1.24μm first Stokes. The pump had an M2 of 15, demonstrating that efficiency is maintained at the highest levels even when using exceptionally poor quality pumps. We show that a measured decrease in the output beam quality factor from M2=2.95 to M2=1.25 as power increased is evidence for thermal lens development in the diamond. The results foreshadow development of continuous-wave kilowatt-class lasers or amplifiers based on single diamond elements and pumped efficiently by lasers having poor spatial coherence such as line-narrowed diode laser arrays.

Optical coherence of diamond nitrogen-vacancy centers formed by ion implantation and annealing

The advancement of quantum optical science and technology with solid-state emitters such as nitrogen-vacancy (NV) centers in diamond critically relies on the coherence of the emitters' optical transitions. A widely employed strategy to create NV centers at precisely controlled locations is nitrogen ion implantation followed by a high-temperature annealing process. We report on experimental data directly correlating the NV center optical coherence to the origin of the nitrogen atom. These studies reveal low-strain, narrow-optical-linewidth ($<500$ MHz) NV centers formed from naturally-occurring $^{14}$N atoms. In contrast, NV centers formed from implanted $^{15}$N atoms exhibit significantly broadened optical transitions ($>1$ GHz) and higher strain. The data show that the poor optical coherence of the NV centers formed from implanted nitrogen is not due to an intrinsic effect related to the diamond or isotope. These results have immediate implications for the positioning accuracy of current NV center creation protocols and point to the need to further investigate the influence of lattice damage on the coherence of NV centers from implanted ions.

Narrative Coherence in Adolescence: Relations With Attachment, Mentalization, and Psychopathology

Narrative coherence refers to the overall completeness of the narrative that helps the individual to draw meaning from past events. Research has predominantly focused on developmental trajectories of narrative coherence among typically developing individuals and less research sheds light on narrative coherence in adolescents facing serious psychological difficulties. This study is the first to apply Baerger and McAdams’s well-validated coding scheme of narrative coherence to adolescents and to rate narrative coherence based on the content derived from the Child Attachment Interview in the context of attachment security, mentalization, and internalizing and externalizing pathology in 70 inpatient adolescents. Findings emphasized that the coding scheme is applicable for adolescents and attachment narratives. Narrative coherence was negatively correlated with age and no gender differences were found. Higher attachment security and better mentalization both contributed to more coherent narratives. More coherent narratives predicted less externalizing problems, but when controlling for mentalization and attachment security, mentalization was the strongest predictor. The relation between narrative coherence and other social-cognitive constructs is discussed, as well as how poor narrative coherence should be taken into account with respect to psychopathology in adolescence. Finally, the value of this coding scheme to evaluating narrative coherence in adolescence is discussed.

Analysing coherence of oral discourse among Cantonese speakers in Mainland China with traumatic brain injury and cerebrovascular accident

Purpose: Coherence can reflect subtle language deficits in individuals with traumatic brain injury (TBI) and cerebrovascular accident (CVA). This study aimed at investigating whether global and local coherence in Cantonese-speaking adults with CVA and TBI differ from non-brain-injured (NBI) speakers. Factors contributing to the coherence ratings and impacts of elicitation tasks on coherence were examined.Method: Two clinical groups with fluent aphasia (7 CVA and 11 TBI) and 18 controls matched in age and education, who were Cantonese speakers living in China participated. Language samples of single and sequential picture description and storytelling were elicited, and subsequently analysed on global and local coherence, content sequence, and informativeness.Result: TBI speakers had impaired global and local coherence, while CVA speakers had poor global coherence. Sequence of main events produced by the three groups correlated significantly with global coherence. Attention and visuospatial skills were also significantly related to global coherence in both clinical groups. Finally, impaired language integrity was associated with problems of local coherence.Conclusion: The results were consistent with previous studies. Linguistic deficits of coherence in discourse in the two clinical groups and possible impacts of elicitation tasks on the cognitive demands and coherence ratings were discussed.

Enhanced vortex beams resistance to turbulence with polarization modulation

Adopting a vortex beam with poor coherence can reduce turbulence-induced beam spreading and wander effects in the atmosphere, but it intensifies the degradation rate of its beam profile from a doughnut shape into a Gaussian shape. Transmission quality of Orbital–angular–momentum (OAM) mode carried by a vortex beam is closely related to its evolution of intensity distribution. After appropriate polarization modulation, a radially polarized vortex beam has a better performance on the reduction of beam spreading and wander effects than its scalar counterpart. A radially polarized vortex beam can also lower the degradation rate of its beam profile and keep “OAM information” a longer distance. Therefore, appropriate polarization modulation can be an effective approach to mitigate the adverse turbulent effects on OAM-based systems operated in the atmosphere.

Improving Corrosion Resistance of Co Using Silane Coupling Treatment in Neutral Solution

Many products using a magnetic property, a mechanical property and chemical property of the thin metal film of the nm order are developing in the great many fields. The establishment of technology for corrosion prevention under nm level or the atom level is necessary to control corrosion without losing the characteristic of these products. In this study, surface treatments using BTSE, BTSPA, and BTSPS were evaluated from the viewpoint of improving the corrosion resistance of thin cobalt films. Corrosion behavior was evaluated corrosion current density using Tafel plots. Treated cobalt films were characterized by XPS and observed by SEM and AFM. A silane-coupling layer formed on the cobalt as a result of each of these treatments. However, the corrosion resistances offered by the different layers varied significantly. Immersion in BTSE with hydrogen peroxide for one hour did not yield an improvement, whereas immersion for 24 hours resulted in a large improvement. In contrast, immersion in BTSPA with hydrogen peroxide for 24 hours did not lead to a corrosion improvement, whereas immersion for one hour provided corrosion resistance. Immersion in BTSPS with hydrogen peroxide for either amount of time yielded no improvement, because of the poor coherency of the deposit on cobalt. These behaviors can be explained in terms of the hard and soft acid-base principle.

Debora: Acceptance and Feasibility of Pain Competence and Depression Prevention Training in Multidisciplinary Inpatient Rehabilitation

A total of 3 partial studies were used for formative evaluation. The triangulative design consisted of problem-centered interviews and focus groups with rehabilitation patients as well as focus groups with experts. The interviews were transcribed, anonymized, and content analysis was performed. The training was well accepted and feasible from the perspective of the patients and experts. The therapists had a significant influence on the participants' satisfaction. Suggestions for improvement focused on developing extensions of the pain and stress management aspects and on discussing individual problems. Compared to the intervention group and independent of depression, the control group assessed the training as being less satisfatory and showed poor group coherence. Results of the formal evaluation support the combined implementation of the Debora pain competence and depression prevention training program and suggest its long-term establishment in multidisciplinary inpatient rehabilitation.

Poor coherence in older people's speech is explained by impaired semantic and executive processes.

The ability to speak coherently is essential for effective communication but declines with age: older people more frequently produce tangential, off-topic speech. The cognitive factors underpinning this decline are poorly understood. We predicted that maintaining coherence relies on effective regulation of activated semantic knowledge about the world, and particularly on the selection of currently relevant semantic representations to drive speech production. To test this, we collected 840 speech samples along with measures of executive and semantic ability from 60 young and older adults, using a novel computational method to quantify coherence. Semantic selection ability predicted coherence, as did level of semantic knowledge and a measure of domain-general executive ability. These factors fully accounted for the age-related coherence deficit. Our results indicate that maintaining coherence in speech becomes more challenging as people age because they accumulate more knowledge but are less able to effectively regulate how it is activated and used.

Propagation properties of partially coherent Lommel beams in non-Kolmogorov turbulence

Based on generalized Huygens–Fresnel principle, the analytical expressions of the partially coherent Lommel beams propagating in turbulent atmosphere are derived. The propagation properties of vortex mode intensity (including mode probability density and crosstalk probability density) of partially coherent Lommel beam in non-Kolmogorov turbulence are investigated in this paper. The research results show that coherence width of partially coherent Lommel beam plays a key role to determine the mode intensity in the process of propagation. The poor coherence of source beams leads to serious dispersion of spiral spectrum distribution. It is worth noting that crosstalk probability density increases to its peak and gradually decreases due to the enhancement of other-order crosstalk. Furthermore, long wavelength and small asymmetry parameter are helpful to mitigate the influence of atmospheric turbulence and restrain the mode crosstalk on the orbital angular momentum mode transmission.