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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.
The trade of live parrots is a threat to wild populations but is understudied. Madagascar is home to three parrot species listed on CITES Appendix II: Coracopsis nigra, Coracopsis vasa and Agapornis canus. Prior to this study there were no data on the ownership of parrots in Madagascar. We therefore aimed to investigate the extent of the domestic pet trade in this group. Our objectives were to quantify the prevalence, spatial extent, and timing of ownership. We collected data in July and August 2016 in nine urban towns across Madagascar, using semi-structured household surveys (n = 440). We found that the ownership of pet parrots is widespread in time and space; 37% (95% CI 26–48%) of interviewees had seen, and 8% (95% CI 3–13%) had owned, a Coracopsis sp. Fewer interviewees (4.5% of all interviewees) had seen A. canus in captivity, and only one individual reported having previously owned an A. canus. We estimate that 1,290 Coracopsis spp. individuals were held in captivity in the towns surveyed, in the 1.5 years prior to our interviews. It is likely that much of this ownership is illegal, although we did not examine this explicitly. Additional research is needed to determine whether current extraction rates are sustainable. This study adds to a growing body of evidence that the domestic regulation of the trade of wild species is not being addressed adequately in Madagascar.
We have mapped the southern galaxies NGC 613, 1313, 1433, 1566, 1672, and 2442 in the 12CO(1-0) line with the SEST telescope. The sample bases on galaxies observed previously in radio continuum at the Molonglo Observatory (Harnett, 1985).
Non-native species impact tropical ecosystems, but the role of different anthropogenic disturbances on the success of non-natives remains unclear, especially in island tropical forests. We sought to understand the influence of anthropogenic habitat degradation and disturbance on non-native plant species in Madagascar. Specifically, we evaluated how densities of non-native species of woody shrub (Lantana camara), climber (Mucuna pruriens) and tree (Mangifera indica, Albizia lebbeck, Tamarindus indica) varied with forest habitat degradation and by disturbance type. We surveyed 60400 m2, recording 482 instances of disturbance and 903 non-native plants in and around the Ankarana National Park. Non-native plant densities were higher in degraded than primary forest. Within degraded forest, densities of non-native trees increased with disturbance. Tree densities correlated with extent of tree damage only in Tamarindus indica, never correlated with extent of tree removal, and always correlated with proximity to roads and trails. Our results suggest roads and trails have relatively greater importance in facilitating the success of non-native tree species than structural changes to habitat. In contrast, densities of Lantana camara and Tamarindus indica did not correlate with any measured type of disturbance; other unmeasured or historical factors may be more important drivers of these smaller, faster-reproducing species.
We report multifrequency observations of the γ-ray blazar 0528+134 with the Effelsberg 100-m telescope, the IRAM 30-m telescope at Pico Veleta and the NRL Green Bank Interferometer. The observing methods are described elsewhere (Reich et al., 1993; Pohl et al., 1995). The radio lightcurves are given in Fig.1 in comparison to the status of 0528+134 in the EGRET energy range. The uncertainties in the flux densities quoted there are less than 5% at 10.55 GHz and lower frequencies, while slightly exceeding this value at 32 GHz and 86 GHz.
We have mapped the southern galaxies NGC 613, 1313, 1433, 1566, 1672 and 2442 in the 12CO(J = 1 → 0) transition with the 15-m Swedish European Submillimetre Telescope (SEST). The sample is based on galaxies previously observed in radio continuum with the Molonglo Observatory Synthesis Telescope (MOST). Strong emission is seen from the barred galaxies NGC 613 and NGC 2442 and from the active galaxies NGC 1566 and 1672. The weakest emission was from NGC 1433, while the Sd spiral NGC 1313 was not detected.
The role of wild meat for subsistence or as a luxury good is debated. We investigated the role of wild meat in food security in Madagascar, where consumption is poorly understood in urban areas and at regional scales. Using semi-structured interviews (n = 1339 heads-of-households, 21 towns), we aimed to: (1) quantify the amount and purpose of, (2) understand the drivers of, and (3) examine changes in wild meat consumption. Few respondents preferred wild meat (8 ± 3%) but most had eaten it at least once in their lifetime (78 ± 7%). Consumption occurred across ethnic groups, in urban and rural settings. More food insecure areas reported higher rates of wild meat consumption in the 6–8 months prior to interviews. Consumption was best explained by individual preferences and taboos. Less than 1% of respondents had increased consumption during their lifetimes. Wild meat prices showed no change from 2005–2013. Most consumption involved wild pigs and smaller-sized animals, though they were consumed less in the years following the 2009 coup. These data illustrate the differences between urban and rural communities, the occasions in which wild meat is used a source of food security, and provide evidence that some taxa are not hunted sustainably in Madagascar.
Marine, freshwater and terrestrial ecosystems face increasing anthropogenic threats that are exacerbated by the ecological connectivity between realms; integrated land-sea management (ILSM) is a framework that can help address this connectivity. However, gaps in our knowledge regarding ILSM remain. This study reviewed 108 relevant studies to understand how ILSM is being utilized. Summarized are: (1) characteristics of integrated land-sea programs; (2) recommendations made from the literature for program planning, implementation and management; (3) how applied programs have been planned, implemented and managed; and (4) recommendations for undertaking ILSM. It was found that applied programs did not often adhere to the strategies recommended by theoretical papers. Applied programs were less likely than theoretical papers to specifically name the land-sea connection, over 50% did not apply a framework or governance approach, many did not include key stakeholders, and over 80% listed at least one conflict or hurdle that decreased program success. This study highlighted the difficulties of undertaking ILSM given the high number of stakeholders, government agencies and experts involved. Based on the findings, recommendations for future ILSM programs are provided.
Overexploitation is a significant threat to biodiversity, with live capture of millions of animals annually. An improved understanding of live capture of primates is needed, especially for Madagascar's threatened lemurs. Our objectives were to provide the first quantitative estimates of the prevalence, spatial extent, correlates and timing of lemur ownership, procurement methods, within-country movements, and numbers and duration of ownership. Using semi-structured interviews of 1,093 households and 61 transporters, across 17 study sites, we found that lemur ownership was widespread and affected a variety of taxa. We estimate that 28,253 lemurs have been affected since 2010. Most lemurs were caught by owners and kept for either short (≤ 1 week) or long (≥ 3 years) periods. The live capture of lemurs in Madagascar is not highly organized but may threaten several Endangered and Critically Endangered species.
We have done a comparative study of carbon-doped GaN and undoped GaN utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies in order to investigate deep levels involved in yellow luminescence (YL) and red luminescence (RL). When the GaN was excited by above-bandgap light, red luminescence (RL) centered at 1.82 eV was the dominant below-gap PL from undoped GaN, but carbon-doped GaN below-gap PL was dominated by yellow luminescence (YL) centered at 2.2 eV. When exciting PL below the band-gap with 2.4 eV light, undoped GaN had a RL peak centered at 1.5 eV and carbon-doped GaN had a RL peak centered at 1.65 eV. PLE spectra of carbon-doped GaN, detecting at 1.56 eV, exhibited a strong, broad excitation band extending from about 2.1 to 2.8 eV with an unusual shape that may be due to two or more overlapping excitation bands. This RL PLE band was not observed in undoped GaN. We also demonstrate that PL spectra excited by below gap light in GaN films on sapphire substrates are readily contaminated by 1.6−1.8 eV and 2.1−2.5 eV chromium-related emission from the substrate. A complete characterization of the Cr emission and excitation bands for sapphire substrates enables the determination of the excitation and detection wavelengths required to obtain GaN PL and PLE spectra that are free of contributions from substrate emission.
Hardness properties of CVD SiO2, films deposited on silicon substrates are investigated by microindentation techniques. It is found that the hardness of these films is sensitive to the thermal histories and doping and is less influenced by the residual stress levels.
Spontaneously laterally ordered (GaP)2/(InP)2 short period superlattices (SPS) grown by Molecular Beam Epitaxy (MBE) on nominal (100) GaAs substrates have been studied by photoluminescence (PL) spectroscopy. The samples studied included SPS comprising 110 pairs of (GaP)2/(InP)2 (total thickness σ90 nm) and multiquantum well structures in which quantum wells comprising 12 pairs of (GaP)2/(InP)2 SPS layers (thickness σ10 nm) are alternated with lattice-matched GaInP random alloy barrier layers. The 5K PL spectra include a σ1760 meV nearband edge band, and a much broader, lower energy (σ1670 meV) luminescence band that exhibits an unusual fatiguing behavior; its intensity diminishes monotonically during continuous illumination by the exciting light. This fatigued PL state is metastable at low temperatures. In the quantum well structure, although the relative intensity of the lower energy band is significantly weaker in comparison to the higher one, the fatiguing behavior still exists. However the fatiguing rate is slower in quantum well structures than that observed in the thick SPS film.
High resolution electron beam lithography and reactive ion etching in methane-hydrogen (CH4/H2) plasmas have been used to fabricate InGaAs/InP open quantum well wires (QWW) with widths ranging from 200 to 40 nm and quantum dots (QD) with diameters ranging from 600 to 100 nm. Low temperature photoluminescence (PL) spectra were investigated in these nanostructures as a function of excitation intensity, wire width, and dot diameter. The peak emission of the dry-etched 40 nm wires is shifted to higher energies by about 2 meV as compared to 100 nm wires. This “open wire” result is consistent with results reported for buried InGaAs/InP wires of the same width. The blue-shift of the PL peak reaches 10 meV in QDs as their diameters decrease to 100 nm. The magnitude of the observed blue shift in the QDs is larger than the blue-shift predicted on the basis of quantum confinement for the same size dots.
We have studied GaN films grown by atmospheric pressure metalorganic chemical vapor deposition (MOCVD) on sapphire substrates using different buffer layer structures. Surface morphology was characterized by scanning electron microscopy (SEM). Optical properties were measured using photoluminescence (PL), cathodoluminescence (CL) spectroscopy and catho-luminescence wavelength imaging (CLWI) method. It is found that the hexagonal pit-like defects in morphology are associated with the D-A/e-A transition band in the PL and CL spectra. The same correlation of morphology with optical properties is observed for the GaN films grown by selective area epitaxy (SAE). In addition, the possibility of improving optical quality by SAE is investigated. The SAE depth profile is simulated for the first time, and satisfactory results are obtained.
We have done a comparative study of carbon-doped GaN and undoped GaN utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies in order to investigate deep levels involved in yellow luminescence (YL) and red luminescence (RL). When the GaN was excited by above-bandgap light, red luminescence (RL) centered at 1.82 eV was the dominant below-gap PL from undoped GaN, but carbon-doped GaN below-gap PL was dominated by yellow luminescence (YL) centered at 2.2 eV. When exciting PL below the band-gap with 2.4 eV light, undoped GaN had a RL peak centered at 1.5 eV and carbon-doped GaN had a RL peak centered at 1.65 eV. PLE spectra of carbon-doped GaN, detecting at 1.56 eV, exhibited a strong, broad excitation band extending from about 2.1 to 2.8 eV with an unusual shape that may be due to two or more overlapping excitation bands. This RL PLE band was not observed in undoped GaN. We also demonstrate that PL spectra excited by below gap light in GaN films on sapphire substrates are readily contaminated by 1.6-1.8 eV and 2.1-2.5 eV chromium-related emission from the substrate. A complete characterization of the Cr emission and excitation bands for sapphire substrates enables the determination of the excitation and detection wavelengths required to obtain GaN PL and PLE spectra that are free of contributions from substrate emission.
An ambient scanning tunneling microscope (STM) was used to excite luminescence in ptype epitaxial GaAs with four separate surface preparations: bare GaAs, Au layer, sulfurmonochloride layer, and one monolayer of octa-decyl-thiol. The STM with tungsten tip was operated at a constant tunnel current of 5 nA during a +1 V bias applied to the sample and the resulting tip to sample distance was fixed during a higher voltage bias pulse which excited luminescence. The luminescence intensity increased rapidly with increasing bias voltage for all passivation types with the octa-decyl-thiol passivation achieving the highest STM excited luminescence (STMEL) of 3500 photons/sec at 4 V bias. Above about 4 V the luminescence from the octa-decyl-thiol and sulfur-monochloride passivated samples fell off irreversibly, indicating that the sample surface had been modified. The Au passivated and unpassivated samples showed no such luminescence drop up to 4.8 V, the highest bias employed. Photoluminescence (PL) studies of the samples showed that PL intensities exhibited a weaker dependence upon passivation type than did STMEL intensities, a result consistent with the assertion that STMEL is more sensitive to the surface properties of the sample than is PL.
The photoluminescence (PL) of GaN grown on SiC is studied as a function of etch depth for two types of etches, photoelectrochemical and chemically assisted ion beam. It is found that as the etch proceeds deeper toward the substrate, the PL exhibits an increasing blue-shift and an increase in emission intensity of the donor acceptor pair band, which indicates increasing biaxial compressive stress and increasing impurity concentration near the substrate. The PL spectra of the dry etched GaN tended to have slightly higher intensities than comparably wet etched GaN.