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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.
Leaf colour characteristics of 730 sweetpotato, Ipomoea batatas (L.) Lam. (Convolvulaceae), plant introduction (PI) accessions from the USDA sweetpotato germplasm collection were evaluated during 2012–2014. Colorimetry data for the abaxial and adaxial leaf surfaces were recorded using a tristimulus colorimeter and the CIE 1976 L*a*b* and CIE L*C*h* colour spaces. Most accessions (725 of 730 PIs) had dark-to-medium green leaves, but two PIs had totally purple leaves, and three PIs had yellow or yellow-green (chartreuse) leaves. For mature, field-grown green leaves, values for the red-green coordinate (a*) averaged −12.4 for the adaxial and −10.4 for the abaxial leaf surface. Values for the blue-yellow coordinate (b*) averaged 17.2 for the adaxial and 17.3 for the abaxial leaf surface. Hue angle (h*) for green leaves averaged 120.9° for the adaxial and 126.2° for the abaxial leaf surface. Colour saturation (Chroma, C*) averaged 21.3 for the adaxial and 20.2 for the abaxial leaf surface. Lightness (L*) averaged 35.4 for the adaxial and 47.2 for the abaxial leaf surface of green leaves. Late in the season, over one-half (53.9%) of the 730 PIs showed some level of purple pigmentation in the leaf lamina. Late-season purple leaves were collected and colour coordinates were recorded for 118 PIs grown in the field. For purple leaves, values for a*, b*, C*, L* and h* averaged 2.3, 6.2, 7.9, 28.2 and 64.4° for the adaxial surface and −1.0, 12.7, 13.9, 43.1 and 87.0° for the abaxial leaf surface, respectively.
During the past two decades, it has been amply documented that neuropsychiatric disorders (NPDs) disproportionately account for burden of illness attributable to chronic non-communicable medical disorders globally. It is also likely that human capital costs attributable to NPDs will disproportionately increase as a consequence of population aging and beneficial risk factor modification of other common and chronic medical disorders (e.g., cardiovascular disease). Notwithstanding the availability of multiple modalities of antidepressant treatment, relatively few studies in psychiatry have primarily sought to determine whether improving cognitive function in MDD improves patient reported outcomes (PROs) and/or is cost effective. The mediational relevance of cognition in MDD potentially extrapolates to all NPDs, indicating that screening for, measuring, preventing, and treating cognitive deficits in psychiatry is not only a primary therapeutic target, but also should be conceptualized as a transdiagnostic domain to be considered regardless of patient age and/or differential diagnosis.
Fractional anisotropy in the uncinate fasciculus and the cingulum may be biomarkers for bipolar disorder and may even be distinctly affected in different subtypes of bipolar disorder, an area in need of further research.
This study aims to establish if fractional anisotropy in the uncinate fasciculus and cingulum shows differences between healthy controls, patients with bipolar disorder type I (BD-I) and type II (BD-II), and their unaffected siblings.
Fractional anisotropy measures from the uncinate fasciculus, cingulum body and parahippocampal cingulum were compared with tractography methods in 40 healthy controls, 32 patients with BD-I, 34 patients with BD-II, 17 siblings of patients with BD-I and 14 siblings of patients with BD-II.
The main effects were found in both the right and left uncinate fasciculus, with patients with BD-I showing significantly lower fractional anisotropy than both patients with BD-II and healthy controls. Participants with BD-II did not differ from healthy controls. Siblings showed similar effects in the left uncinate fasciculus. In a subsequent complementary analysis, we investigated the association between fractional anisotropy in the uncinate fasciculus and polygenic risk for bipolar disorder and psychosis in a large cohort (n = 570) of healthy participants. However, we found no significant association.
Fractional anisotropy in the uncinate fasciculus differs significantly between patients with BD-I and patients with BD-II and healthy controls. This supports the hypothesis of differences in the physiological sub-tract between bipolar disorder subtypes. Similar results were found in unaffected siblings, suggesting the potential for this biomarker to represent an endophenotype for BD-I. However, fractional anisotropy in the uncinate fasciculus seems unrelated to polygenic risk for bipolar disorder or psychosis.
Pathological worry is a hallmark feature of generalised anxiety disorder (GAD), associated with dysfunctional emotional processing. The ventromedial prefrontal cortex (vmPFC) is involved in the regulation of such processes, but the link between vmPFC emotional responses and pathological v. adaptive worry has not yet been examined.
To study the association between worry and vmPFC activity evoked by the processing of learned safety and threat signals.
In total, 27 unmedicated patients with GAD and 56 healthy controls (HC) underwent a differential fear conditioning paradigm during functional magnetic resonance imaging.
Compared to HC, the GAD group demonstrated reduced vmPFC activation to safety signals and no safety–threat processing differentiation. This response was positively correlated with worry severity in GAD, whereas the same variables showed a negative and weak correlation in HC.
Poor vmPFC safety–threat differentiation might characterise GAD, and its distinctive association with GAD worries suggests a neural-based qualitative difference between healthy and pathological worries.
Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.
To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.
Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.
A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).
The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.
Declaration of interest
Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
The Star Centre is a national astronomy and space science base which
facilitates public access to news and information
promotes public awareness, interest, enjoyment and understanding.
The Star Centre meets these twin aims by providing an information service which can be accessed in a variety of ways and by offering a menu of public observing events.
The concept of a national astronomy base developed as part of the Centre for Science Educations growing portfolio of initiatives in both the formal education sector and the wider umbrella of the Public Understanding of Science. In December 1996 the Star Centre was launched with the aid of a Royal Society COPUS development grant and matching funding from Sheffield Hallam University.
A sub-sea permafrost drilling program was conducted near Prudhoe Bay, Alaska. Sub-sea permafrost was found at all offshore drill sites and was characterized as being ice bonded or unbonded. The unbonded sub-sea permafrost occurred in a thin layer at the sea bed; the near-shore thickness of this layer appears to be controlled by the bathymetry. The mean annual sea-bed temperatures were about —3.4°C at 203 m offshore, — 1.1°C at 481 m offshore and —0.7°C at 3370 m offshore. The thermal diffusivity was about 21 m2 a-1 for unbonded sandy gravel with silt. The sub-sea permafrost soils were sandy gravel with some silt overlain by a thin layer of silty sand which increased in thickness from a few meters near shore to about 14 m at 3370 m offshore. A few small ice lenses were found in a hole 195 m offshore but no massive ice was observed. Pore-water salt concentrations at the sea bed were 3-4 times that of normal sea-water where ice was frozen to the sea bed and 1–2 times that of normal sea-water otherwise. Preliminary laboratory experiments showed that the saturated hydraulic conductivity of the unbonded sub-sea permafrost was about 10–6–10–7 m s–1. The permeability of the subterranean permafrost was zero.
In the original publication of this article, the title was printed as “Four Preceramic Points Newly Discovered in Belize: A Comment on Stemp et al. (1996:279–299).” The article has been updated to the correct title. The authors apologize for this error.
Tropical bamboos persist in a wide range of light conditions and quickly respond to changes in light availability. However, the mechanisms underpinning this ability remain unknown. In order to test the hypothesis that the modular and hollow culm architecture of bamboos explains their performance in a wide range of light environments, we determined the allometric relationships of two dominant bamboo species of the upper hill dipterocarp forests of Malaysia, Gigantochloa ligulata (n = 29) and Schizostachyum grande (n = 25), via destructive sampling. We also monitored biomass turnover of bamboos and woody trees in 24 permanent plots (1.92 ha in total) over a one-year period. Compared with woody trees, bamboo culms attained 1.5 times the height and their clumps supported four times as much total leaf area at the same above-ground biomass. In addition, at a given height, bamboo clumps had six times larger crown projection area than trees while having a similar amount of total leaf area per unit of crown projection area. Finally, bamboos’ biomass turnover rate was three times higher than trees, and G. ligulata increased its specific rate of biomass increase after canopy disturbance, while trees decreased. We conclude that the unique architecture of bamboos allows them to persist under closed forest canopy light conditions and to respond to gap formation via high biomass turnover rate.
Stemp et al. (2016) published data on 81 preceramic (Archaic) points from Belize, Central America. In this comment, we report four more chipped chert bifaces recently recovered in Belize (Figure 1). Based on metrics (Table 1), technology, and style, three are classified as Lowe and one as a Sawmill point (Kelly 1993; Lohse et al. 2006; Stemp et al. 2016).
Some of the ideas about glacier surging are considered, mainly but not entirely in the light of observations of temperate glaciers in Alaska, U.S.A., made within the last 15 years. Climate has an influence on surge recurrence interval. Climate and weather also affect surge initiation, termination and magnitude. Regional studies lead to the speculation that subglacial “till” plays a key role in surging, and it has been found under all surge-type glaciers studied so far, including Black Rapids and Variegated Glaciers, Alaska. In most of the glaciers studied, till deformation processes dominate the motion in quiescence. The linked-cavity model of surge triggering and rapid motion is not consistent with these observations, but the limited coverage of the observations does not rule it out under parts of the glaciers studied. The till observations in Alaska raise old questions about the interaction between till and the hydraulic systems of temperate glaciers. The role of stored water, which observations show to be active even in winter on Black Rapids Glacier, is noted.
Microscopic and textural observations were made on ice samples cored from Blue Glacier slightly below the equilibrium line to depths of 60 m. Observations were started within a few minutes after collection. Water was found in veins along three-grain intersections, in lenses on grain boundaries and in irregular shapes. Gas was found in bubbles in the interior of crystals, in bubbles touching veins, and locally in veins. Vein sizes showed some spread; average cross-sectional area was about 7 × 10−4 mm2 with no discernible, trend with texture or depth except within 7 m of the surface. Before the samples were examined they could have experienced a complex relaxation which could have changed them significantly. As a result it is not possible to determine the in situ size of veins, but an upper limit can be determined. Also it is not possible to predict intergranular water flux per unit area, but 1 × 10−1 m a−1 represents an upper limit. In coarse-grained ice the water flux density is likely to be even smaller, because of a low density of veins, and blocking by bubbles. This indicates that only a very small fraction of the melt-water production on a typical summer day can penetrate into the glacier on an intergranular scale except possibly near the surface. The existence of conduit-like features in several cores suggests that much melt water can nevertheless penetrate the ice locally without large-scale lateral movements along the glacier surface. The observed profile of ice temperature indicates that the intergranular water flux may be much smaller than the upper limit determined from the core samples.
Black Rapids Glacier is a 40 km long surge-type glacier in the central Alaska Range. In spring 1997 a wireline drill rig was set up at a location where the measured surface velocities are high and seasonal and annual velocity variations are large. The drilling revealed a layer of subglacial “till”, up to 7 m thick, that is believed to be water-saturated. At one location a string of instruments, containing three dual-axis tiltmeters and one piezometer, was successfully introduced into the till. The tiltmeters monitored the inclination of the borehole at the ice–till interface and at 1 and 2 m into the till, for 410 days. They showed that no significant deformation occurred in the upper 2 m of the till layer, and no significant amount of the basal motion was due to sliding of the ice over the till. The measured surface velocity at the drill site is about 60 m a−1, of which 20–30 m a can be accounted for by ice deformation. Almost the entire amount of basal motion, 30–40 m a−1, was taken up at a depth of > 2 m in the till, possibly in discrete shear layers, or as sliding of till over the underlying bedrock. We propose that the large-scale mobilization of such till layers is a key factor in initiating glacier surges.