218 research outputs found
Neurocognitive Functioning in Individuals at Clinical High Risk for Psychosis
IMPORTANCE: Neurocognitive functioning is a potential biomarker to advance detection, prognosis, and preventive care for individuals at clinical high risk for psychosis (CHR-P). The current consistency and magnitude of neurocognitive functioning in individuals at CHR-P are undetermined. OBJECTIVE: To provide an updated synthesis of evidence on the consistency and magnitude of neurocognitive functioning in individuals at CHR-P. DATA SOURCES: Web of Science database, Cochrane Central Register of Reviews, and Ovid/PsycINFO and trial registries up to July 1, 2020. STUDY SELECTION: Multistep literature search compliant with Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology performed by independent researchers to identify original studies reporting on neurocognitive functioning in individuals at CHR-P. DATA EXTRACTION AND SYNTHESIS: Independent researchers extracted the data, clustering the neurocognitive tasks according to 7 Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) domains and 8 CHR-P domains. Random-effect model meta-analyses, assessment of publication biases and study quality, and meta-regressions were conducted. MAIN OUTCOMES AND MEASURES: The primary effect size measure was Hedges g of neurocognitive functioning in individuals at CHR-P (1) compared with healthy control (HC) individuals or (2) compared with individuals with first-episode psychosis (FEP) or (3) stratified for the longitudinal transition to psychosis. RESULTS: A total of 78 independent studies were included, consisting of 5162 individuals at CHR-P (mean [SD; range] age, 20.2 [3.3; 12.0-29.0] years; 2529 [49.0%] were female), 2865 HC individuals (mean [SD; range] age, 21.1 [3.6; 12.6-29.2] years; 1490 [52.0%] were female), and 486 individuals with FEP (mean [SD; range] age, 23.0 [2.0; 19.1-26.4] years; 267 [55.9%] were female). Compared with HC individuals, individuals at CHR-P showed medium to large deficits on the Stroop color word reading task (gâ=ââ1.17; 95% CI, â1.86 to â0.48), Hopkins Verbal Learning TestâRevised (gâ=ââ0.86; 95% CI, â1.43 to â0.28), digit symbol coding test (gâ=ââ0.74; 95% CI, â1.19 to â0.29), Brief Assessment of Cognition Scale Symbol Coding (gâ=ââ0.67; 95% CI, â0.95 to â0.39), University of Pennsylvania Smell Identification Test (gâ=ââ0.55; 95% CI, â0.97 to â0.12), Hinting Task (gâ=ââ0.53; 95% CI, â0.77 to â0.28), Rey Auditory Verbal Learning Test (gâ=ââ0.50; 95% CI, â0.78 to â0.21), California Verbal Learning Test (CVLT) (gâ=ââ0.50; 95% CI, â0.64 to â0.36), and National Adult Reading Test (gâ=ââ0.52; 95% CI, â1.01 to â0.03). Individuals at CHR-P were less impaired than individuals with FEP. Longitudinal transition to psychosis from a CHR-P state was associated with medium to large deficits in the CVLT task (gâ=ââ0.58; 95% CI, â1.12 to â0.05). Meta-regressions found significant effects for age and education on processing speed. CONCLUSIONS AND RELEVANCE: Findings from this meta-analysis support neurocognitive dysfunction as a potential detection and prognostic biomarker in individuals at CHR-P. These findings may advance clinical research and inform preventive approaches
GaN-based distributed feedback laser diodes for optical communications
Over the past 20 years, research into Gallium Nitride (GaN) has evolved from LED lighting to Laser Diodes (LDs), with applications ranging from quantum to medical and into communications. Previously, off-the-shelf GaN LDs have been reported with a view on free space and underwater communications. However, there are applications where the ability to select a single emitted wavelength is highly desirable, namely in atomic clocks or in filtered free-space communications systems. To accomplish this, Distributed Feedback (DFB) geometries are utilised. Due to the complexity of overgrowth steps for buried gratings in III-Nitride material systems, GaN DFBs have a grating etched into the sidewall to ensure single mode operation, with wavelengths ranging from 405nm to 435nm achieved. The main motivation in developing these devices is for the cooling of strontium ions (Sr+) in atomic clock applications, but their feasibility for optical communications have also been investigated. Data transmission rates exceeding 1 Gbit/s have been observed in unfiltered systems, and work is currently ongoing to examine their viability for filtered communications. Ultimately, transmission through Wavelength Division Multiplexing (WDM) or Orthogonal Frequency Division Multiplexing (OFDM) is desired, to ensure that data is communicated more coherently and efficiently. We present results on the characterisation of GaN DFBs, and demonstrate their capability for use in filtered optical communications systems
InGaN/GaN Laser Diodes and their Applications
Gallium nitride (GaN) laser diodes are becoming popular sources not only for lighting but for applications ranging from communications to quantum. This paper presents the use of a commercial, off-the-shelf laser diode, with an emission wavelength of 450 nm, for visible light communication, both in free space and for underwater scenarios. Data rates up to 15 Gbit/s have been achieved by making use of orthogonal frequency division multiplexing (OFDM). In addition, distributed feedback (DFB) lasers have been realised emitting at a single wavelength which lend themselves towards applications where high spectral purity is crucial such as atomic clocks or filtered free space transmission systems. These devices have the grating structure etched into the sidewall of the ridge and work is ongoing to measure the linewidth of these lasers with the intended application of cooling Sr+ ions
Using Line Profiles to Test the Fraternity of Type Ia Supernovae at High and Low Redshifts
Using archival data of low-redshift (z < 0.01) Type Ia supernovae (SN Ia) and
recent observations of high-redshift (0.16 < z <0.64; Matheson et al. 2005) SN
Ia, we study the "uniformity'' of the spectroscopic properties of nearby and
distant SN Ia. We find no difference in the measures we describe here. In this
paper, we base our analysis solely on line-profile morphology, focusing on
measurements of the velocity location of maximum absorption (vabs) and peak
emission (vpeak). We find that the evolution of vabs and vpeak for our sample
lines (Ca II 3945, Si II 6355, and S II 5454, 5640) is similar for both the
low- and high-redshift samples. We find that vabs for the weak S II 5454, 5640
lines, and vpeak for S II 5454, can be used to identify fast-declining [dm15 >
1.7] SN Ia, which are also subluminous. In addition, we give the first direct
evidence in two high-z SN Ia spectra of a double-absorption feature in Ca II
3945, an event also observed, though infrequently, in low-redshift SN Ia
spectra (6/22 SN Ia in our local sample). We report for the first time the
unambiguous and systematic intrinsic blueshift of peak emission of optical
P-Cygni line profiles in Type Ia spectra, by as much as 8000 km/s. All the
high-z SN Ia analyzed in this paper were discovered and followed up by the
ESSENCE collaboration, and are now publicly available.Comment: 28 pages (emulateapj), 15 figures; accepted for publication in A
Applications of Single Frequency Blue Lasers
Gallium nitride (GaN) sources are becoming a regular part of today's world and are now key devices for lighting infrastructures, communications systems and quantum applications, amongst others. In particular, many applications have seen the shift from LEDs to laser diodes to make use of higher powers, higher bandwidths and increased transmission distances. Laser communication systems are well established, however there are applications where the ability to select a single emitted wavelength is highly desirable, such as quantum atomic clocks or in filtered communication systems. Distributed feedback (DFB) lasers have been realised emitting at a single wavelength where the grating structure is etched into the sidewall of the ridge. The main motivation in developing these lasers is for the cooling of ions in atomic clocks; however their feasibility for optical communications is also explored. Narrow linewidth lasers are desirable and this paper will explore how this is achieved. Data rates in excess of 1 Gbit/s have also been achieved in a directly modulated, unfiltered system. These devices lend themselves towards wavelength division multiplexing and filtered optical communications systems and this will be analysed further in the work presented here
Potential improvements in global carbon flux estimates from a network of laser heterodyne radiometer measurements of column carbon dioxide
We present observing system simulation experiments (OSSEs) to evaluate the impact of a proposed network of ground-based miniaturized laser heterodyne radiometer (mini-LHR) instruments that measure atmospheric column-averaged carbon dioxide (XCO2) with a 1 ppm precision. A particular strength of this passive measurement approach is its insensitivity to clouds and aerosols due to its direct sun pointing and narrow field of view (0.2). Developed at the NASA Goddard Space Flight Center (GSFC), these portable, low-cost mini-LHR instruments were designed to operate in tandem with the sun photometers used by the AErosol RObotic NETwork (AERONET). This partnership allows us to leverage the existing framework of AERONET's global ground network of more than 500 sites as well as providing simultaneous measurements of aerosols that are known to be a major source of error in retrievals of XCO2 from passive nadir-viewing satellite observations. We show, using the global 3-D GEOS-Chem chemistry transport model, that a deployment of 50 mini-LHRs at strategic (but not optimized) AERONET sites significantly improves our knowledge of global and regional land-based CO2 fluxes. This improvement varies seasonally and ranges 58%81% over southern lands, 47%76% over tropical lands, 71%92% over northern lands, and 64%91% globally. We also show significant added value from combining mini-LHR instruments with the existing ground-based NOAA flask network. Collectively, these data result in improved a posteriori CO2 flux estimates on spatial scales of 10 km2, especially over North America and Europe, where the ground-based networks are densest. Our studies suggest that the mini-LHR network could also play a substantive role in reducing carbon flux uncertainty in Arctic and tropical systems by filling in geographical gaps in measurements left by ground-based networks and space-based observations. A realized network would also provide necessary data for the quinquennial global stock takes that form part of the Paris Agreement
Quantitative Expression and Co-Localization of Wnt Signalling Related Proteins in Feline Squamous Cell Carcinoma.
Feline oral squamous cell carcinoma (FOSCC) is an aggressive neoplasm in cats. Little is known about the possible molecular mechanisms that may be involved in the initiation, maintenance and progression of FOSCC. Wnt signalling is critical in development and disease, including many mammalian cancers. In this study, we have investigated the expression of Wnt signalling related proteins using quantitative immunohistochemical techniques on tissue arrays. We constructed tissue arrays with 58 individual replicate tissue samples. We tested for the expression of four key Wnt/Ă-catenin transcription targets, namely Cyclin D1 (CCND1 or CD1), FRA1, c-Myc and MMP7. All antibodies showed cross reactivity in feline tissue except MMP7. Quantitative immunohistochemical analysis of single proteins (expressed as area fraction / amount of tissue for normal vs tumor, mean ± SE) showed that the expression of CD1 (3.9 ± 0.5 vs 12.2 ± 0.9), FRA1 (5.5 ± 0.6 vs 16.8 ± 1.1) and c-Myc (5.4 ± 0.5 vs 12.5 ± 0.9) was increased in FOSCC tissue by 2.3 to 3 fold compared to normal controls (p<0.0001). By using a multilabel, quantitative fluorophore technique we further investigated if the co-localization of these proteins (all transcription factors) with each other and in the nucleus (stained with 4',6-diamidino-2-phenylindole, DAPI) was altered in FOSCC compared to normal tissue. The global intersection coefficients, a measure of the proximity of two fluorophore labeled entities, showed that there was a significant change (p < 0.01) in the co-localization for all permutations (e.g. CD1/FRA1 etc), except for the nuclear localization of CD1. Our results show that putative targets of Wnt signalling transcription are up-regulated in FOSCC with alterations in the co-localization of these proteins and could serve as a useful marker for the disease.This research was funded by the Prostate Cancer Research Centre charity (registered UK charity no. 1156027), Grant Number AA1. A small financial contribution was also made through intra-mural funds from the Royal Veterinary College.This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pone.016110
Adaptation of water resources systems to changing society and environment: a statement by the International Association of Hydrological Sciences
Hydrol. Sci. J.-J. Sci. Hydrol.ISI Document Delivery No.: EB2CDTimes Cited: 0Cited Reference Count: 153Ceola, Serena Montanari, Alberto Krueger, Tobias Dyer, Fiona Kreibich, Heidi Westerberg, Ida Carr, Gemma Cudennec, Christophe Elshorbagy, Amin Savenije, Hubert Van der Zaag, Pieter Rosbjerg, Dan Aksoy, Hafzullah Viola, Francesco Petrucci, Guido MacLeod, Kit Croke, Barry Ganora, Daniele Hermans, Leon Polo, Maria J. Xu, Zongxue Borga, Marco Helmschrot, Jorg Toth, Elena Ranzi, Roberto Castellarin, Attilio Hurford, Anthony Brilly, Mitija Viglione, Alberto Bloeschl, Guenter Sivapalan, Murugesu Domeneghetti, Alessio Marinelli, Alberto Di Baldassarre, GiulianoPeople Programme (Marie Curie Actions) of the European Union [329762]; IRI THESys; German Excellence Initiative; EU [603587]IW acknowledges the support of the People Programme (Marie Curie Actions) of the European Union's 7th Framework Programme FP7/2007-2013/(grant agreement no. 329762). TK is funded, through IRI THESys, by the German Excellence Initiative. SC, AM, AC, and ET acknowledge financial support from the EU funded project SWITCHON (603587).Taylor & francis ltdAbingdonWe explore how to address the challenges of adaptation of water resources systems under changing conditions by supporting flexible, resilient and low-regret solutions, coupled with on-going monitoring and evaluation. This will require improved understanding of the linkages between biophysical and social aspects in order to better anticipate the possible future co-evolution of water systems and society. We also present a call to enhance the dialogue and foster the actions of governments, the international scientific community, research funding agencies and additional stakeholders in order to develop effective solutions to support water resources systems adaptation. Finally, we call the scientific community to a renewed and unified effort to deliver an innovative message to stakeholders. Water science is essential to resolve the water crisis, but the effectiveness of solutions depends, inter alia, on the capability of scientists to deliver a new, coherent and technical vision for the future development of water systems
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Frequency and pattern of childhood symptom onset reported by first episode schizophrenia and clinical high risk youth
BackgroundâPsychosis prevention and early intervention efforts in schizophrenia have focused increasingly on sub-threshold psychotic symptoms in adolescents and young adults. Although many youth report symptom onset prior to adolescence, the childhood incidence of prodromal level symptoms in those with schizophrenia or related psychoses is largely unknown. MethodsâThis study reports on the retrospective recall of prodromal-level symptoms from 40 participants in a first-episode of schizophrenia (FES) and 40 participants at âclinical high riskâ (CHR) for psychosis. Onset of positive and non-specific symptoms was captured using the Structured Interview for Prodromal Syndromes. Frequencies are reported according to onset during childhood (prior to age 13), adolescence (13â17), or adulthood (18 +). ResultsâChildhood-onset of attenuated psychotic symptoms was not rare. At least 11% of FES and 23% of CHR reported specific recall of childhood-onset of unusual or delusional ideas, suspiciousness, or perceptual abnormalities. Most recalled experiencing non-specific symptoms prior to positive symptoms. CHR and FES did not differ significantly in the timing of positive and non-specific symptom onset. Other than being younger at assessment, those with childhood onset did not differ demographically from those with later onset. ConclusionâChildhood-onset of initial psychotic-like symptoms may be more common than previous research has suggested. Improved characterization of these symptoms and a focus on their predictive value for subsequent schizophrenia and other major psychoses are needed to facilitate screening of children presenting with attenuated psychotic symptoms. Accurate detection of prodromal symptoms in children might facilitate even earlier intervention and the potential to alter pre-illness trajectories
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