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Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
In this article, an extremely wideband, isolation-enhanced, low-profile “Multiple-Input-Multiple-Output” (MIMO) antenna along with dual-band-notched features has been investigated. The antenna proposed herein, possesses two mutually orthogonal staircase-etched radiators for achieving a wide bandwidth. The radiating elements are placed mutually perpendicular in order to achieve polarization diversity and high isolation, i.e. for minimization of mutual coupling effect between adjacent radiating elements. The antenna exhibits an extremely wide frequency bandwidth covering 1.2–19.4 GHz except two frequency band notches centered at 3.5 and 5.5 GHz, respectively, originated due to the incorporation of a “Rectangular Complementary Split Ring Resonator (RCSRR)” structure and by etching dual “L-shaped” slits in the ground plane. The center frequency of the notched bands is adjusted by fine tuning of the dimensions of the incorporated band-notching structures. Isolation level (S21) better than −20 dB has been obtained due to the insertion of a “T-shaped” parasitic element as a decoupling structure. A prototype of the proposed antenna having dimension of 20 mm × 20 mm (0.08 λo × 0.08 λo) is fabricated and the antenna responses have been measured. Obtained results show that the miniaturized MIMO diversity antenna is undoubtedly a capable contender for communications supporting an extremely wide impedance bandwidth along with band-notched features for WLAN and WiMAX.
Objective: This study aimed to systematically review the effects of currently prescribed antiparkinson medication on cognition in patients with mild-to-moderate Parkinson’s disease (PD) who were either cognitively intact or mildly impaired. Methods: English- and French-language studies published between 1969 and 2017 were accessed via MedLine, PsychNET, EMBASE and EBSCO databases. Methodological quality (MQ) was evaluated with the quality assessment instrument of the Cochrane Collaboration Depression, Anxiety and Neurosis Review (scores from 0% to 44% indicate very low quality; scores from 45% to 64% indicate low quality; scores from 65% to 84% indicate medium quality; and scores from 85% to 100% indicate high quality). Hedges’ g and Student’s t-test were performed on all cognitive outcome measures reported. Results: In total, 14 studies assessed the cognitive effects of levodopa (L-D), pramipexole (PRX), selegiline (SEL) and rasagiline (RAS) in mild-to-moderate non-demented PD patients. The MQ was overall low, with an average score of 49.1%. Results for L-D showed deleterious effects on a test of cognitive inhibition, as well as benefits on tests of attention/processing speed/working memory, executive functions and episodic memory. Pramipexole was associated with a worsening of episodic memory and impulse control. Results on SEL indicated a deterioration of global cognition over time and of concept formation. Rasagiline had some benefits on working memory and verbal fluency. Conclusion: Antiparkinson medications can have deleterious (L-D; PRX; SEL) and beneficial (L-D; RAS) effects on cognition. However, randomized double-blind placebo-controlled trials with larger sample sizes are required to better elucidate this issue.
We present predictions for the spatial distribution of 21 cm brightness temperature fluctuations from high-dynamic-range simulations for AGN-dominated reionization histories that have been tested against available Lyα and CMB data. We model AGN by extrapolating the observed Mbh–σ relation to high redshifts and assign them ionizing emissivities consistent with recent UV luminosity function measurements. AGN-dominated reionization histories increase the variance of the 21 cm emission by a factor of up to ten compared to similar reionization histories dominated by faint galaxies, to values close to 100 mK2 at scales accessible to experiments (k ≲ 1 cMpc−1h). This is lower than the sensitivity reached by ongoing experiments by only a factor of about two or less. AGN dominated reionization should be easily detectable by LOFAR (and later HERA and SKA1) at their design sensitivity.
Between austral late winter 1993 and austral autumn 1998, during five cruises aboard the research vessel Nathaniel B. Palmer, almost 300 m of core was obtained from first-year ice floes in the Ross, Amundsen and Bellingshausen Seas. Analysis of the texture, stratigraphy and stable-isotopic composition of the ice was used to assess the magnitude of the role of flooding and snow-ice formation at the base of the snowpack in the thickening of the ice cover and the thinning of the snow cover. Snow ice occurred in all ice-thickness categories and made a significant contribution to the total ice mass (12−36%) in both autumn and winter. Although the amount of snow ice was often exceeded by the amount of frazil ice and congelation ice, the thickness of individual layers of each ice type indicated that snow ice often made a greater contribution to the thermodynamic thickening of the ice cover than the other ice types. The larger quantities of frazil ice and congelation ice were primarily the result of dynamic thickening. Flooding and snow-ice formation reduced the snow cover to 42−70% of the total snow accumulation depending on time and location. On the basis of this information, ship-based snow-depth estimates were adjusted to estimate the total snow accumulation on different ice-thickness categories.
Austral summer sea-ice processes were investigated in January 1999 during a cruise of the R.V. Nathaniel B. Palmer in the central and eastern Ross Sea, Antarctica. The crystal texture, 18O/16O ratios, density and salinity of ice cores and of ice blocks ‘perched’ on slush at the ice surface were studied. The perched ice blocks had a distinctive polygonal granular (PG) crystal texture and very negative isotope signature that were also characteristic of layers at the top of first-year floes and of layers ‘buried’ below the surface in multi-year floes. The PG ice is superimposed ice that results from melting in the snow cover and refreezing at the slush surface and directly on top of ice floes. If PG ice is buried after the ice surface floods and the resultant slush freezes, then snow ice forms above the PG ice. The contribution of superimposed ice to floe surface mass balance and some implications with respect to weather and climate are discussed.
Surface exposure dating was applied to erosional shorelines associated with the Angliers lake level that marks an important stage of Lake Ojibway. The distribution of 15 10Be ages from five sites shows a main group (10 samples) of coherent 10Be ages yielding a mean age of 9.9±0.7 ka that assigns the development of this lake level to the early part of the Lake Ojibway history. A smaller group (3 samples) is part of a more scattered distribution of older 10Be ages (with 2 outliers) that points to an inheritance of cosmogenic isotopes from a previous exposure, revealing an apparent mean age of 15.8±0.9 ka that is incompatible with the Ojibway inundation and the regional deglaciation. Our results provide the first direct 10Be chronology on the sequence of lake levels in the Ojibway basin, which includes the lake stage presumably associated with the confluence and subsequent drainage of Lakes Agassiz and Ojibway. This study demonstrates the potential of this approach to date glacial lake shorelines and underlies the importance of obtaining additional chronological constraints on the Agassiz-Ojibway shoreline sequence to confidently assign a particular lake stage and/or lake-level drawdown to a specific time interval of the deglaciation.
Snow-pack along the land-fast ice fringe off the north coast of Ellesmere Island was generally characterized by depth-hoar overlain by dense snow and wind slab. Mean snow depth in the study area was 0.54 m (1982-85) and the mean δ18O value of the snow-pack was -31.3˚/00. Isotope data were not obtained previously for this geographic region and, therefore, complement a previous study of δ18O variations in High Arctic snow (Koerner, 1979). The data are consistent with an Arctic Ocean moisture source. The δ18O profiles show seasonal variations, with winter snow being more depleted in 18O than fall and spring snow. However, the δ18O profiles are dominated by a trend to higher δ18O values with increasing depth. This is attributed to a decrease in δ18O values as condensation temperatures fall during the autumn-winter accumulation period. During this time, there is also a change from relatively open to almost complete ice cover in the Arctic Ocean. The change in evaporation conditions and consequent effect on δ values gives rise to a sharp discontinuity in the δ18O profiles and a bi-modal δ18O frequency distribution. The bi-modal distribution is reinforced by a secondary isotope fractionation that occurs during depth-hoar formation. This isotope effect leads to a wider δ18O range but does not significantly alter the mean δ18O value.
The salinity and isotope (18O, 3H) content of multi-year landfast sea-ice (MLSI) cores from northern Ellesmere Island, Canada, are examined. Salinity ranges from 0.01‰ to 4.54‰, and δ18O ranges from −23.8‰ to +0.7‰. Salinity and δ18O are linearly related, and tritium values generally exceed natural background levels. The results are evidence of ice growth associated with fresh-water / sea-water stratification below the ice. Salinity variations are cyclic and indicate a mean annual bottom accretion rate of 0.33–0.5 m a−1. Rather than signifying downward percolation of melt water from the surface, the ice δ values are a proxy measure of variations in salinity and 18O content of the water below the ice. Annual salinity layers are preserved in the absence of significant brine movement and ice deformation. The fast-ice environment appears to favour the maintenance of water stratification and growth of annual layers. It is suggested that ice growth in this environment is somewhat independent of thermodynamic sea-ice growth models; instead, ice growth by a double-diffusion process might account for the growth of MLSI beyond thicknesses normally encountered in undeformed multi-year pack-ice floes.
Ice salinity and 18O/16O ratios were measured on 12 ice cores drilled from thick, multi-year land-fast sea ice (MLSI) off the north coast of Ellesmere Island, Canada. Fresh, brackish, and sea ice were identified in the ice cores using the 18O/16O ratios. Two cases are considered: case 1, which assumes that no isotopic fractionation occurs on freezing; and, case 2, which assumes that a maximum isotopic fractionation factor (a) of 1.003 applies. The amount of each ice type is variable among the cores, but overall the 12 cores comprise 29.6% brackish ice, 70.0% sea ice, and 0.4% fresh ice in case 1, and 42.3% brackish ice, 57.3% sea ice, and 0.4% fresh ice in case 2. The data suggest that time-dependent brackish sea-water stratification below the ice is quite common and is often associated with the inverted bottom topography. However, the stratification is not always confined to small, areally limited under-ice melt pools in inverted depressions, and neither is it a summer-only phenomenon. Brackish ice growth apparently occurs in a brackish water layer that in some instances underlies the ice sheet year-round. For both case 1 and case 2 the salinity distribution in brackish ice is positively skewed, with 50% of salinity values occurring in the range 0–0.49‰. Sea-ice salinity values are more evenly distributed. In case 1, brackish ice has mean salinity and mean δ18O values of 0.66 and –19.9‰, respectively, compared to mean values of 1.88 and –6.5‰ for the sea ice. In case 2, brackish ice has mean salinity and mean S18O values of 0.75 and –18.1% compared to mean values of 2.03 and –5.2‰ for the sea ice. The salinity of brackish ice and sea ice, ice-growth mechanisms, and the inclusion of brine in the sub-structure are discussed briefly.
Hobson’s Choice Ice Island is a tabular iceberg that calved in 1982-83 from East Ward Hunt Ice Shelf, N.W.T., Canada. Four ice cores have been analyzed for ice-crystal size, structure and fabric, bulk density, liquid electrical conductivity, δ18O and tritium. This has enabled a complete characterization of the physical properties and the structural characteristics of the ice-shelf component of Hobson’s Choice Ice Island and the first ever study of the stratigraphy and growth history of East Ward Hunt Ice Shelf. The δ18O values range from -34.6 to and indicate that all the ice is derived directly and/or indirectly from precipitation. High tritium values occur only in the lowermost 5 m of the ice shelf in a layer named stratum B. The tritium is anthropogenic and indicates bottom accretion of fresh-water ice since 1952, most likely from fresh water flowing out of Disraeli Fiord below the eastern ice shelf. Above this deepest and youngest ice layer is a 35-38 m thick, unconformable layer (stratum A) comprising three ice types: iced-firn, slush ice and lake ice. This depositional-superimposed ice represents past surface accumulation, which, according to δ18O and ice-crystal structure and size variations, occurred in three major periods, each interrupted by major ablation periods. Fresh water flowing out of Disraeli Fiord below the ice shelf during those warm intervals was the most likely agent responsible for the ablation and eventual complete loss of the original sea-ice platform on which stratum A initially accumulated. The three sub-strata of stratum A vary in thickness from core to core and suggest that there has been an inversion of relief during each ablation period. The different properties and occurrences of the three superimposed ice types are due primarily to past topographic variability.
Ice-core drilling and ice-core analysis (electrical conductivity–salinity, 18O, 3H, density) reveal that the internal structure of the west Ward Hunt Ice Shelf contrasts sharply with that of the east ice shelf. The west ice shelf contains a great thickness (≥22 m) of sea ice (mean salinity, 2.22‰; mean δ18O, -0.8‰), whereas the east ice shelf is entirely of meteoric or fresh-water ice (mean salinity 0.01‰; mean δ18O, -29.7‰). High tritium activities are found only in ice from near the bottom of the east and west ice shelves. The contrasting ice-core data is considered to be a proxy record of variations in water circulation and bottom freezing beneath the ice shelf. The west shelf is underlain by sea water flowing into Disraeli Fiord. Sea ice accretes on to the bottom of the west ice shelf from the sea-water flowing into the fiord. Sea-water flowing out of the fiord is directed below the east ice shelf. However, the east ice shelf is not underlain directly by sea-water but by a layer of fresh water from the surface of Disraeli Fiord. In this region, ice growth resulting from the presence of this stable fresh-water layer has been accompanied by surface ablation over a period of perhaps the last 450 years. As a result, fresh-water ice has completely replaced any sea ice that originally grew in the region of the east ice shelf. Whereas the west and east shelves are underlain almost exclusively by sea-water and fresh water, ice in the south shelf is the result of freezing of fresh, brackish or sea water. This is attributed to mixing of the inflowing and outflowing waters.
We present high resolution Chandra X-ray imaging of two starburst galaxies, M82 and NGC 3256. The central x-ray source observed by ROSAT and ASCA in M82 is resolved into 3 or 4 sources. Most of these sources are variable, suggesting that the point sources are powered by accretion. The brightest of these central sources is ∼ 1041ergs s−1 in the high state, and is responsible for the variability observed by ROSAT and ASCA. Assuming this source radiates at the Eddington limit, the mass is ∼ 500M⊙. The diffuse hard (2-10 keV) emission in M82 is spatially coincident with diffuse radio emission and Pα. This is consistent with diffuse hard X-ray emission arising from hot thermal gas in the starburst region. Approximately 14 sources with LX > 1039ergs s−1 were detected in NGC 3256, including both nuclei. Two of these sources have LX > 1040ergs s−1. This observation suggests that “super Edington” sources may be preferentially associated with starburst galaxies (see also paper by Fabbiano in this volume)
Hα + [NII] and red continuum CCD images as well as high resolution aperture synthesis CO maps were obtained in order to study the optical jet of the barred spiral galaxy NGC 4258. The CO observations show two clouds near the center of the galaxy; these clouds outline a channel and the Hα jet follows this channel. The observations are consistent with the jet being in or making a small angle with the galaxy plane. It is concluded that the interstellar medium may play an important role in making jets detectable optically and in shaping their forms.
Reginald Pecock, bishop of St. Asaph and subsequently of Chichester, has surely been one of the most misrepresented of men. Condemned in his later years as a heretic, he was grossly misunderstood by that garrulous prophet of doom, Thomas Gascoigne, who described him as this ‘Pacock’ who loosed arrows at the sun, one of which by the just judgment of God fell upon his own head. John Foxe allotted him a place as a protestant confessor and Father Robert Parsons wished the martyrologist joy of one who had [allegedly] denied three articles of the Creed and ‘perjuriously abjured’ against his conscience.
Healthcare workers (HCWs), especially those caring for patients with tuberculosis (TB), are at high risk of acquiring that disease. The poor specificity of tuberculin skin testing (TST) prompted us to evaluate the effectiveness of the interferon-γ release assay (IGRA) in comparison with TST in a large prospective, multicenter, 1-year study of HCWs with occupational exposure to TB.
HCWs from high-risk units at 14 university hospitals were invited to participate and underwent both TST and IGRA (first Quantiferon TB Gold-IT®, QFT-G, then T-SPOT.TB® if QFT-G was indeterminate) at baseline and after 1 year. We collected demographic characteristics, country of birth, history of TB, immunosuppression, past exposure to TB, history of BCG vaccination, results of most recent TST, job category, and duration of current function.
Among 807 HCWs enrolled, current or past TST at baseline was positive (≥15 mm) in 282 (34.9%); the IGRA was positive in 113 (14.0%) and indeterminate in 3 (0.4%). After 1 year, 594 HCWs had both an IGRA and TST (or prior TST≥15 mm) at baseline and an IGRA and TST (if indicated). The conversion rate was 2.5% (9 of 367) with TST and 7.6% (45 of 594) with IGRA, with poor agreement between the 2 tests. Using only QFT-G, conversion (9.9%) and reversion (17.8%) rates were higher for baseline QFT-G positive quantitative values <1 IU/mL.
TST and the IGRA yielded discordant results. The value of IGRA in addition to TST remains undetermined; the two should be jointly interpreted in decision-making (clinical trial registration NCT00797836).