Seasonal Climate Prediction and Predictability of Atmospheric Circulation

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Accerlerating acculturation through tacit knowledge flows: refining a grounded theory model

DOI 10.1108/03055721011071430Purpose - Intercultural knowledge flows are critical to global enterprise performance, but the impact of knowledge management theory on such intercultural flows remains limited. This paper seeks to address this issue

Nanostructured Transition Metal Compounds as Highly Efficient Electrocatalysts for Dye-Sensitized Solar Cells

Nowadays, the requirement of energy increases every year, however, the major energy resource is fossil fuel, a limiting source. Dye-sensitized solar cells (DSSCs) are a promising renewable energy source, which could be the major power supply for the future. Recently, the transition metal component has been demonstrated as potential material for counter electrode of platinum (Pt)-free DSSCs owing to their excellent electrocatalytic ability and their abundance on earth. Furthermore, the transition metal components exist different special nanostructures, which provide high surface area and various electron transport routs during electrocatalytic reaction. In this chapter, transition metal components with different nanostructures used for the application of electrocatalyst in DSSCs will be introduced; the performance of electrocatalyst between intrinsic heterogeneous rate constant and effective electrocatalytic surface area are also be clarified. Final, the advantages of the electrocatalyst with different dimensions (i.e., one to three dimension structures) used in DSSCs are also summarized in the conclusion

Intensified impact of tropical Atlantic SST on the western North Pacific summer climate under a weakened Atlantic thermohaline circulation

The tropical North Atlantic (TNA) sea surface temperature (SST) has been identified as one of regulators on the boreal summer climate over the western North Pacific (WNP), in addition to SSTs in the tropical Pacific and Indian Oceans. The major physical process proposed is that the TNA warming induces a pair of cyclonic circulation anomaly over the eastern Pacific and negative precipitation anomalies over the eastern to central tropical Pacific, which in turn lead to an anticyclonic circulation anomaly over the western to central North Pacific. This study further demonstrates that the modulation of the TNA warming to the WNP summer climate anomaly tends to be intensified under background of the weakened Atlantic thermohaline circulation (THC) by using a water-hosing experiment. The results suggest that the weakened THC induces a decrease in thermocline depth over the TNA region, resulting in the enhanced sensitivity of SST variability to wind anomalies and thus intensification of the interannual variation of TNA SST. Under the weakened THC, the atmospheric responses to the TNA warming are westward shifted, enhancing the anticyclonic circulation and negative precipitation anomaly over the WNP. This study supports the recent finding that the negative phase of the Atlantic multidecadal oscillation after the late 1960s has been favourable for the strengthening of the connection between TNA SST variability and WNP summer climate and has important implications for seasonal prediction and future projection of the WNP summer climate

Drug Resistance via Feedback Activation of Stat3 in Oncogene-Addicted Cancer Cells

SummaryPathway-targeted cancer drugs can produce dramatic responses that are invariably limited by the emergence of drug-resistant cells. We found that many drug-treated “oncogene-addicted” cancer cells engage a positive feedback loop leading to Stat3 activation, consequently promoting cell survival and limiting overall drug response. This was observed in cancer cells driven by diverse activated kinases, including EGFR, HER2, ALK, and MET, as well as mutant KRAS. Specifically, MEK inhibition led to autocrine activation of Stat3 via the FGF receptor and JAK kinases, and pharmacological inhibition of MEK together with JAK and FGFR enhanced tumor regression. These findings suggest that inhibition of a Stat3 feedback loop may augment the response to a broad spectrum of drugs that target pathways of oncogene addiction

Nonlinear forced change and nonergodicity: The case of ENSO-Indian monsoon and global precipitation teleconnections

We study the forced response of the teleconnection between the El Nino-Southern Oscillation (ENSO) and global precipitation in general and the Indian summer monsoon (IM) in particular in the Max Planck Institute Grand Ensemble. The forced response of the teleconnection is defined as the time-dependence of a correlation coefficient evaluated over the ensemble. The ensemble-wise variability is taken either wrt. spatial averages or dominant spatial modes in the sense of Maximal Covariance Analysis or Canonical Correlation Analysis or EOF analysis. We find that the strengthening of the ENSO-IM teleconnection is robustly or consistently featured in view of all four teleconnection representations, whether sea surface temperature (SST) or sea level pressure (SLP) is used to characterise ENSO, and both in the historical period and under the RCP8.5 forcing scenario. The main contributor to this strengthening in terms of a linear regression model is the regression coefficient, which can outcompete even a declining ENSO variability in view of using the SLP. We also find that the forced change of the teleconnection is typically nonlinear by (1) formally rejecting the hypothesis that ergodicity holds, i.e., that expected values of temporal correlation coefficients with respect to the ensemble equal the ensemble-wise correlation coefficient itself, and also showing that (2) the trivial contributions of the forced changes of e.g. the mean SST and/or precipitation to temporal correlations are insignificant here. We also provide, in terms of the test statistics, global maps of the degree of nonlinearity/nonergodicity of the forced change of the teleconnection between local precipitation and ENSO

Structural Engineering on Pt-Free Electrocatalysts for Dye-Sensitized Solar Cells

In recent decades, plenty of nanomaterials have been investigated as electrocatalysts for the replacement of the expensive platinum (Pt) counter electrode in dye-sensitized solar cells (DSSCs). The key function of the electrocatalyst is to reduce tri-iodide ions to iodide ions at the electrolyte/counter electrode interface. The performance of the electrocatalyst is usually determined by two key factors, i.e., the intrinsic heterogeneous rate constant and the effective electrocatalytic surface area of the electrocatalyst. The intrinsic heterogeneous rate constant of the electrocatalyst varies by different types of materials, which can be roughly divided into five groups: non-Pt metals, carbons, conducting polymers, transition metal compounds, and their composites. The effective electrocatalytic surface area is determined by the nanostructure of the electrocatalyst. In this chapter, the nanostructural design and engineering on different types of Pt-free electrocatalysts will be systematically introduced. Also, the relationship between various nanostructures of electrocatalysts and the pertinent physical/electrochemical properties will be discussed

Carbon-Based Nanocomposite Materials for High-Performance Supercapacitors

Lightweight, flexible, wearable, and portable electronic gadgets have drawn significant attention in modern electronics industry. To power these gadgets, great efforts have been made to develop highly efficient energy-storage equipment. Among various power sources, a supercapacitor, acting as a bridge between the conventional battery and electrolytic capacitor, has been considered a promising portable energy storage device because of its high power density, fast charge/discharge rate, adequate operational safety, and excellent working lifetime. Hybrid supercapacitors, which combine redox materials with carbon-based materials, exhibit tremendous potential to fulfill the requirement of practical applications. In this chapter, we will review recent reports focusing on composite materials (i.e. metal oxide, metal hydroxide, and metal dichalcogenide composited with carbon materials) for the application in supercapacitors. The conclusion and futuristic prospects and challenges of highly efficient supercapacitors are briefly discussed