161 research outputs found
Alternative forest management strategies to account for climate change-induced productivity and species suitability changes in Europe
We present for the first time a study on alternative forest management at the European scale to account for climate change impacts. We combine insights into detailed studies at high resolution with the actual status of the forest and a realistic estimate of the current management practices at large scale. Results show that the European forest system is very inert and that it takes a long time to influence the species distribution by replacing species after final felling. By 2070, on average about 36 % of the area expected to have decreased species suitability will have changed species following business as usual management. Alternative management, consisting of shorter rotations for those species and species planting based on expected trends, will have increased this species transition to 40 %. The simulated forward-looking alternative management leads to some reduction in increment, but does not influence the amount of wood removed from the forest. Northern Europe is projected to show the highest production increases under climate change and can also adapt faster to the new (proposed) species distribution. Southwest Europe is expected to face the greatest challenge by a combination of a predicted loss of production and a slow rate of management alteration under climate change
The 3q Oncogene SEC62 Predicts Response to Neoadjuvant Chemotherapy and Regulates Tumor Cell Migration in Triple Negative Breast Cancer
In the absence of targeted treatment options, neoadjuvant chemotherapy (NACT) is applied
widely for triple-negative breast cancer (TNBC). Response to NACT is an important parameter
predictive of oncological outcomes (progression-free and overall survival). An approach to the
evaluation of predictive markers enabling therapy individualization is the identification of tumor
driver genetic mutations. This study was conducted to investigate the role of SEC62, harbored at 3q26
and identified as a driver of breast cancer pathogenesis, in TNBC. We analyzed SEC62 expression
in The Cancer Genome Atlas database, and immunohistologically investigated SEC62 expression
in pre- and post-NACT tissue samples from 64 patients with TNBC treated at the Department of
Gynecology and Obstetrics/Saarland University Hospital/Homburg between January 2010 and
December 2018 and compared the effect of SEC62 on tumor cell migration and proliferation in
functional assays. SEC62 expression dynamics correlated positively with the response to NACT
(p ≤ 0.01) and oncological outcomes (p ≤ 0.01). SEC62 expression stimulated tumor cell migration
(p ≤ 0.01). The study findings indicate that SEC62 is overexpressed in TNBC and serves as a
predictive marker for the response to NACT, a prognostic marker for oncological outcomes, and a
migration-stimulating oncogene in TNBC
Benchmarking and Firm Heterogeneity in Electricity Distribution: A Latent Class Analysis of Germany
In January 2009 Germany introduced incentive regulation for the electricity distribution sector based on results obtained from econometric and nonparametric benchmarking analysis. One main problem for the regulator in assigning the relative efficiency scores are unobserved firm-specific factors such as network and technological differences. Comparing the efficiency of different firms usually assumes that they operate under the same production technology, thus unobserved factors might be inappropriately understood as inefficiency. To avoid this type of misspecification in regulatory practice estimation is carried out in two stages: in a first stage observations are classified into two categories according to the size of the network operators. Then separate analyses are conducted for each sub-group. This paper shows how to disentangle the heterogeneity from inefficiency in one step, using a latent class model for stochastic frontiers. As the classification is not based on a priori sample separation criteria it delivers more robust, statistical significant and testable results. Against this backround we analyze the level of technical efficiency of a sample of 200 regional and local German electricity distribution companies for a balanced panel data set (2001-2005). Testing the hypothesis if larger distributors operate under a different technology than smaller ones we assess if a single step latent class model provides new insights to the use of benchmarking approaches within the incentive regulation schemes
EZH2 Depletion Blocks the Proliferation of Colon Cancer Cells
The Enhancer of Zeste 2 (EZH2) protein has been reported to stimulate cell growth in some cancers and is therefore considered to represent an interesting new target for therapeutic intervention. Here, we investigated a possible role of EZH2 for the growth control of colon cancer cells. RNA interference (RNAi)-mediated intracellular EZH2 depletion led to cell cycle arrest of colon carcinoma cells at the G1/S transition. This was associated with a reduction of cell numbers upon transient transfection of synthetic EZH2-targeting siRNAs and with inhibition of their colony formation capacity upon stable expression of vector-borne siRNAs. We furthermore tested whether EZH2 may repress the growth-inhibitory p27 gene, as reported for pancreatic cancer. However, expression analyses of colon cancer cell lines and colon cancer biopsies did not reveal a consistent correlation between EZH2 and p27 levels. Moreover, EZH2 depletion did not re-induce p27 expression in colon cancer cells, indicating that p27 repression by EZH2 may be cell- or tissue-specific. Whole genome transcriptome analyses identified cellular genes affected by EZH2 depletion in colon cancer cell lines. They included several cancer-associated genes linked to cellular proliferation or invasion, such as Dag1, MageD1, SDC1, Timp2, and Tob1. In conclusion, our results demonstrate that EZH2 depletion blocks the growth of colon cancer cells. These findings might provide benefits for the treatment of colon cancer
Productivity in Electricity Retail after Market Liberalisation: Analysing the Effects of Ownership and Firm's Governance Structure
This paper, which is one of the first to estimate productivity in retail electricity for a European country after liberalisation, analyses the effect of ownership and governance structure by using a unique dataset of German electricity retailers from 2003 to 2012. An innovative service production function for the retail sector is derived with labour and external services as the main inputs. A structural model is used with a proxy function for productivity to overcome the endogeneity of input choice. Ownership is controlled for in the law of motion for productivity. The results of the dataset used to validate the model show that firm-level productivity did not increase after 2008 and that ownership had no effect on productivity. The results provide useful insights into the link between ownership and productivity in modern public enterprises after liberalisation
Clamp loader ATPases and the evolution of DNA replication machinery
Clamp loaders are pentameric ATPases of the AAA+ family that operate to ensure processive DNA replication. They do so by loading onto DNA the ring-shaped sliding clamps that tether the polymerase to the DNA. Structural and biochemical analysis of clamp loaders has shown how, despite differences in composition across different branches of life, all clamp loaders undergo the same concerted conformational transformations, which generate a binding surface for the open clamp and an internal spiral chamber into which the DNA at the replication fork can slide, triggering ATP hydrolysis, release of the clamp loader, and closure of the clamp round the DNA. We review here the current understanding of the clamp loader mechanism and discuss the implications of the differences between clamp loaders from the different branches of life
Potential Gains from Mergers in Local Public Transport: An Efficiency Analysis Applied to Germany
We analyze potential gains from hypothetical mergers in local public transport using the non-parametric Data Envelopment Analysis with bias corrections by means of bootstrapping. Our sample consists of 41 public transport companies from Germany's most densely populated region, North Rhine-Westphalia. We merge them into geographically meaningful, larger units that operate partially on a joint tram network. Merger gains are then decomposed into individual technical efficiency, synergy and size effects following the methodology of Bogetoft and Wang [Bogetoft, P., Wang, D., 2005. Estimating the Potential Gains from Mergers. Journal of Productivity Analysis, 23(2), 145-171]. Our empirical findings suggest that substantial gains up to 16 percent of factor inputs are present, mainly resulting from synergy effects
Measurement of the 'Underlying Energy Efficiency' in Chinese Provinces
China is one of the largest consumers of energy globally. The country also emits some of the highest levels of CO2 globally. In 2009, 18% of the world’s total energy was consumed in China and the growth rate of energy consumption in China is 6.4% per year. In recent years, the Chinese government decided to introduce several energy policy instruments to promote energy efficiency. For instance, reduction targets for the level of energy intensity have been defined for provinces in China. However, energy intensity is not an accurate proxy for energy efficiency because changes in energy intensity are a function of changes in several socioeconomic factors. For this reason, in this paper we present an empirical analysis on the measurement of the persistent and transient “underlying energy efficiency” of Chinese provinces. For this purpose, a log-log aggregate energy demand frontier model is estimated by employing data on 29 provinces observed over the period 1996 to 2008. Several econometric model specifications for panel data are used: the random effects model and the true random effects model along with other versions of these models. Our analysis shows that energy intensity cannot measure accurately the level of efficiency in the use of energy in Chinese provinces. Further, our empirical analysis shows that the average value of the persistent “underlying energy efficiency” is around 0.78 whereas the average value of the transient “underlying energy efficiency” is approximately 0.93
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