Spatial-temporal dynamics of China's terrestrial biodiversity: A dynamic habitat index diagnostic

Biodiversity in China is analyzed based on the components of the Dynamic Habitat Index (DHI). First, observed field survey based spatial patterns of species richness including threatened species are presented to test their linear relationship with remote sensing based DHI (2001-2010 MODIS). Areas with a high cumulative DHI component are associated with relatively high species richness, and threatened species richness increases in regions with frequently varying levels of the cumulative DHI component. The analysis of geographical and statistical distributions yields the following results on interdependence, polarization and change detection: (1) The decadal mean Cumulative Annual Productivity (DHI-cum 4) in Southeast China are in a stable (positive) relation to the Minimum Annual Apparent Cover (DHI-min) and is positively (negatively) related to the Seasonal Variation of Greenness (DHI-sea); (2) The decadal tendencies show bimodal frequency distributions aligned near DHI-min~0.05 and DHI-sea~0.5 which separated by zero slopes; that is, regions with both small DHI-min and DHI-sea are becoming smaller and vice versa; (3) The decadal tendencies identify regions of land-cover change (as revealed in previous research). That is, the relation of strong and significant tendencies of the three DHI components with climatic or anthropogenic induced changes provides useful information for conservation planning. These results suggest that the spatial-temporal dynamics of China's terrestrial species and threatened species richness needs to be monitored by first and second moments of remote sensing based information of the DHI. © 2016 by the authors

Spatiotemporal heterogeneity analysis of Yangtze River delta urban agglomeration: evidence from nighttime light data (2001-2019)

The long-term changes of the relationship between nighttime light and urbanization related built-up areas are explored using nighttime light data obtained from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS, data before 2013) and the Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP/VIIRS, data after 2012) and information of the spatiotemporal heterogeneity of urban evolution. This study assimilates two datasets and diagnoses the spatial heterogeneity in administrative city scale based on built-up area tendencies, temporal heterogeneity in pixel scale based on nighttime light intensity tendencies, and GDP associated spatiotemporal variability over the Yangtze River Delta comparing the first two decades of this century (2001-2010 versus 2011-2019). The analysis reveals the following main results: (1) The built-up areas have generally increased in the second period with the center of fast expansion moving southward, including Suzhou-Wuxi-Changzhou, Hangzhou, Ningbo, Nanjing, and Hefei. (2) Urban development in the original city core has saturated and is spilling over to the suburbs and countryside, leading to nighttime light intensity tendency shift from a "rapid to moderate" and a "moderate to rapid" development (a "hot to cold" and a "cold to hot" spatial clustering distribution). (3) The tendency shifts of built-up area and nighttime light intensity occur most frequently in 2010, after which the urban development is transforming from light intensity growth to built-up area growth, particularly in the developed city cores. The urban agglomeration process with nighttime light intensity reaching saturation prior to the urban development spreading into the surrounding suburbs and countryside, appears to be a suitable model, which provides insights in addressing related environmental problems and contribute to regional sustainable urban planning and management

Volcanic forcing improves Atmosphere-Ocean Coupled General Circulation Model scaling performance

Recent Atmosphere-Ocean Coupled General Circulation Model (AOGCM) simulations of the twentieth century climate, which account for anthropogenic and natural forcings, make it possible to study the origin of long-term temperature correlations found in the observed records. We study ensemble experiments performed with the NCAR PCM for 10 different historical scenarios, including no forcings, greenhouse gas, sulfate aerosol, ozone, solar, volcanic forcing and various combinations, such as it natural, anthropogenic and all forcings. We compare the scaling exponents characterizing the long-term correlations of the observed and simulated model data for 16 representative land stations and 16 sites in the Atlantic Ocean for these scenarios. We find that inclusion of volcanic forcing in the AOGCM considerably improves the PCM scaling behavior. The scenarios containing volcanic forcing are able to reproduce quite well the observed scaling exponents for the land with exponents around 0.65 independent of the station distance from the ocean. For the Atlantic Ocean, scenarios with the volcanic forcing slightly underestimate the observed persistence exhibiting an average exponent 0.74 instead of 0.85 for reconstructed data.Comment: 4 figure

Testing variational estimation of process parameters and initial conditions of an earth system model

We present a variational assimilation system around a coarse resolution Earth System Model (ESM) and apply it for estimating initial conditions and parameters of the model. The system is based on derivative information that is efficiently provided by the ESM's adjoint, which has been generated through automatic differentiation of the model's source code. In our variational approach, the length of the feasible assimilation window is limited by the size of the domain in control space over which the approximation by the derivative is valid. This validity domain is reduced by non-smooth process representations. We show that in this respect the ocean component is less critical than the atmospheric component. We demonstrate how the feasible assimilation window can be extended to several weeks by modifying the implementation of specific process representations and by switching off processes such as precipitation

Assessing the skill of precipitation and temperature seasonal forecasts in Spain: windows of opportunity related to ENSO events

1. The skill of state-of-the-art operational seasonal forecast models in extratropical latitudes is assessed using a multimodel ensemble from the Development of a European Multimodel Ensemble System for Seasonalto- Interannual Prediction (DEMETER) project. In particular, probabilistic forecasts of surface precipitation and maximum temperature in Spain are analyzed using a high-resolution observation gridded dataset (Spain02). To this aim, a simple statistical test based on the observed and predicted tercile anomalies is used. First, the whole period 1960–2000 is considered and it is shown that the only significant skill is found for dry events in autumn. Then, the influence of ENSO events as a potential source of conditional predictability is studied and the validation to strong La Niña or El Niño periods is restricted. Skillful seasonal predictions are found in partial agreement with the observed teleconnections derived from the historical records. On the one hand, predictability is found in spring related to El Niño events for dry events over the south and the Mediterranean coast and for hot events in the southeast areas. In contrast, La Niña drives predictability in winter for dry events over the western part and for hot events in summer over the south and the Mediterranean coast. This study considers both the direct model outputs and the postprocessed predictions obtained using a statistical downscaling method based on analogs. In general, the use of the downscaling method outperforms the direct output for precipitation, whereas in the case of the temperature no improvement is obtained

Carotid stenting: is there an operator effect? A pooled analysis from the carotid stenting trialists' collaboration.

BACKGROUND AND PURPOSE: Randomized clinical trials show higher 30-day risk of stroke or death after carotid artery stenting compared with surgery. We examined whether operator experience is associated with 30-day risk of stroke or death in the Carotid Stenting Trialists' Collaboration database. METHODS: The Carotid Stenting Trialists' Collaboration is a pooled individual patient database including all patients recruited in 3 randomized trials of stenting versus endarterectomy for symptomatic carotid stenosis (Endarterectomy Versus Angioplasty in patients with Symptomatic Severe Carotid Stenosis trial, Stent-Protected Angioplasty versus Carotid Endarterectomy trial, and International Carotid Stenting Study). Lifetime carotid artery stenting experience, lifetime experience in stenting procedures excluding the carotid, and annual number of procedures performed within the trial (in-trial volume), divided into tertiles, were used to measure operator experience. The outcome event was the occurrence of any stroke or death within 30 days of the procedure. The analysis was done per protocol. RESULTS: Among 1546 patients who underwent carotid artery stenting, 120 (7.8%) had a stroke or death within 30 days of the procedure. The 30-day risk of stroke or death did not differ according to operator lifetime carotid artery stenting experience (P=0.8) or operator lifetime stenting experience excluding the carotid (P=0.7). In contrast, the 30-day risk of stroke or death was significantly higher in patients treated by operators with low (mean ≤3.2 procedures/y; risk 10.1%; adjusted risk ratio=2.30 [1.36-3.87]) and intermediate annual in-trial volumes (3.2-5.6 procedures/y; 8.4%; adjusted risk ratio=1.93 [1.14-3.27]) compared with patients treated by high annual in-trial volume operators (>5.6 procedures/y; 5.1%). CONCLUSIONS: Carotid stenting should only be performed by operators with annual procedure volume ≥6 cases per year

Causality of biodiversity loss: Climate, vegetation, and urbanization in China and America

Essential for directing conservation resources is to identify threatened vertebrate regions and diagnose the underlying causalities. Through relating vertebrates and threatened vertebrates to the rainfall-runoff chain, to the food chain, and to the human impact of urbanization, the following relationships are noticed: (i) The Earth’s vertebrates generally show increasing abundance and decreasing threatened species indicator (threatened species number/species abundance) for a higher Normalized Difference Vegetation Index (NDVI) or larger city-size. (ii) Regional vertebrates reveal a notable ‘U-shape profile’ (‘step-like jump’) of threatened species indicator occurs in the moderate (high) NDVI regions in China (America). (iii) Positive/green city states emerge in China and are characterized by the lowest threatened species indicators in areas of low to moderate greenness, where the greenness trend of change during the last 30 years is about three times higher in the urbanized areas than over land. (iv) Negative/brown city states emerge in America revealing high threatened species indicators for greenness exceeding NDVI > 0.2, where similar greenness trends are of both urbanized and land areas. The occurrence of green and brown city states suggests a biodiversity change pattern characterized by the threatened species indicator declining from city regimes with high to those with low indicator values for increasing ratio of the city-over-land NDVI trends. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

Direct, stereodivergent, and catalytic Michael additions of thioimides to α,β-unsaturated aldehydes – Total synthesis of Tapentadol

Direct and stereodivergent Michael additions of N-acyl 1,3-thiazinane-2-thiones to α,β-unsaturated aldehydes catalyzed by chiral nickel(II) complexes are reported. The reactions proceed with a remarkable regio-, diastereo-, and enantioselectivity, so access to any of the four potential Michael stereoisomers is granted through the appropriate choice of the chiral ligand of the nickel(II) complex. Simple removal of the heterocyclic scaffold furnishes a wide array of either syn or anti enantiomerically pure derivatives, which can be exploited for the asymmetric synthesis of biologically active compounds, as demonstrated in a new approach to tapentadol. In turn, a mechanism, based on theoretical calculations, is proposed to account for the stereochemical outcome of these transformations

Right-Sided Location Not Associated With Missed Colorectal Adenomas in an Individual-Level Reanalysis of Tandem Colonoscopy Studies

Background & Aims Interval cancers occur more frequently in the right colon. One reason could be that right-sided adenomas are frequently missed in colonoscopy examinations. We reanalyzed data from tandem colonoscopies to assess adenoma miss rates in relation to location and other factors. Methods We pooled data from 8 randomized tandem trials comprising 2218 patients who had diagnostic or screening colonoscopies (adenomas detected in 49.8% of patients). We performed a mixed-effects logistic regression with patients as cluster effects with different independent parameters. Factors analyzed included location (left vs right, splenic flexure as cutoff), adenoma size, form, and histologic features. Analyses were controlled for potential confounding factors such as patient sex and age, colonoscopy indication, and bowel cleanliness. Results Right-side location was not an independent risk factor for missed adenomas (odds ratio [OR] compared with the left side, 0.94; 95% CI, 0.75–1.17). However, compared with adenomas ≤5 mm, the OR for missing adenomas of 6–9 mm was 0.62 (95% CI, 0.44–0.87), and the OR for missing adenomas of ≥10 mm was 0.51 (95% CI, 0.33–0.77). Compared with pedunculated adenomas, sessile (OR, 1.82; 95% CI, 1.16–2.85) and flat adenomas (OR, 2.47; 95% CI, 1.49–4.10) were more likely to be missed. Histologic features were not significant risk factors for missed adenomas (OR for adenomas with high-grade intraepithelial neoplasia, 0.68; 95% CI, 0.34–1.37 and OR for sessile serrated adenomas, 0.87; 95% CI, 0.47–1.64 compared with low-grade adenomas). Men had a higher number of adenomas per colonoscopy (1.27; 95% CI, 1.21–1.33) than women (0.86; 95% CI, 0.80–0.93). Men were less likely to have missed adenomas than women (OR for missed adenomas in men, 0.73; 95% CI, 0.57–0.94). Conclusions In an analysis of data from 8 randomized trials, we found that right-side location of an adenoma does not increase its odds for being missed during colonoscopy but that adenoma size and histologic features do increase risk. Further studies are needed to determine why adenomas are more frequently missed during colonoscopies in women than men

Intercomparison of the northern hemisphere winter mid-latitude atmospheric variability of the IPCC models

We compare, for the overlapping time frame 1962-2000, the estimate of the northern hemisphere (NH) mid-latitude winter atmospheric variability within the XX century simulations of 17 global climate models (GCMs) included in the IPCC-4AR with the NCEP and ECMWF reanalyses. We compute the Hayashi spectra of the 500hPa geopotential height fields and introduce an integral measure of the variability observed in the NH on different spectral sub-domains. Only two high-resolution GCMs have a good agreement with reanalyses. Large biases, in most cases larger than 20%, are found between the wave climatologies of most GCMs and the reanalyses, with a relative span of around 50%. The travelling baroclinic waves are usually overestimated, while the planetary waves are usually underestimated, in agreement with previous studies performed on global weather forecasting models. When comparing the results of various versions of similar GCMs, it is clear that in some cases the vertical resolution of the atmosphere and, somewhat unexpectedly, of the adopted ocean model seem to be critical in determining the agreement with the reanalyses. The GCMs ensemble is biased with respect to the reanalyses but is comparable to the best 5 GCMs. This study suggests serious caveats with respect to the ability of most of the presently available GCMs in representing the statistics of the global scale atmospheric dynamics of the present climate and, a fortiori, in the perspective of modelling climate change.Comment: 39 pages, 8 figures, 2 table