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ND3, ND1 and 39kDa subunits are more exposed in the de-active form of bovine mitochondrial complex I
(2014)
An intriguing feature of mitochondrial complex I from several species is the so-called A/D transition, whereby the idle enzyme spontaneously converts from the active (A) form to the de-active (D) form. The A/D transition plays an important role in tissue response to the lack of oxygen and hypoxic deactivation of the enzyme is one of the key regulatory events that occur in mitochondria during ischaemia. We demonstrate for the first time that the A/D conformational change of complex I does not affect the macromolecular organisation of supercomplexes in vitro as revealed by two types of native electrophoresis. Cysteine 39 of the mitochondrially-encoded ND3 subunit is known to become exposed upon de-activation. Here we show that even if complex I is a constituent of the I+III2+IV (S1) supercomplex, cysteine 39 is accessible for chemical modification in only the D-form. Using lysine-specific fluorescent labelling and a DIGE-like approach we further identified two new subunits involved in structural rearrangements during the A/D transition: ND1 (MT-ND1) and 39kDa (NDUFA9). These results clearly show that structural rearrangements during de-activation of complex I include several subunits located at the junction between hydrophilic and hydrophobic domains, in the region of the quinone binding site. De-activation of mitochondrial complex I results in concerted structural rearrangement of membrane subunits which leads to the disruption of the sealed quinone chamber required for catalytic turnover.
Memory Concerns, Memory Performance and Risk of Dementia in Patients with Mild Cognitive Impairment
(2014)
Background: Concerns about worsening memory (“memory concerns”; MC) and impairment in memory performance are both predictors of Alzheimer's dementia (AD). The relationship of both in dementia prediction at the pre-dementia disease stage, however, is not well explored. Refined understanding of the contribution of both MC and memory performance in dementia prediction is crucial for defining at-risk populations. We examined the risk of incident AD by MC and memory performance in patients with mild cognitive impairment (MCI).
Methods: We analyzed data of 417 MCI patients from a longitudinal multicenter observational study. Patients were classified based on presence (n = 305) vs. absence (n = 112) of MC. Risk of incident AD was estimated with Cox Proportional-Hazards regression models.
Results: Risk of incident AD was increased by MC (HR = 2.55, 95%CI: 1.33–4.89), lower memory performance (HR = 0.63, 95%CI: 0.56–0.71) and ApoE4-genotype (HR = 1.89, 95%CI: 1.18–3.02). An interaction effect between MC and memory performance was observed. The predictive power of MC was greatest for patients with very mild memory impairment and decreased with increasing memory impairment.
Conclusions: Our data suggest that the power of MC as a predictor of future dementia at the MCI stage varies with the patients' level of cognitive impairment. While MC are predictive at early stage MCI, their predictive value at more advanced stages of MCI is reduced. This suggests that loss of insight related to AD may occur at the late stage of MCI.
Background: Dengue fever (DF) is the most rapidly spreading mosquito-borne viral disease in the world. In this decade it has expanded to new countries and from urban to rural areas. Nepal was regarded DF free until 2004. Since then dengue virus (DENV) has rapidly expanded its range even in mountain regions of Nepal, and major outbreaks occurred in 2006 and 2010. However, no data on the local knowledge, attitude and practice (KAP) of DF in Nepal exist although such information is required for prevention and control measures.
Methods: We conducted a community based cross-sectional survey in five districts of central Nepal between September 2011 and February 2012. We collected information on the socio-demographic characteristics of the participants and their knowledge, attitude and practice regarding DF using a structured questionnaire. We then statistically compared highland and lowland communities to identify possible causes of observed differences.
Principal findings: Out of 589 individuals interviewed, 77% had heard of DF. Only 12% of the sample had good knowledge of DF. Those living in the lowlands were five times more likely to possess good knowledge than highlanders (P<0.001). Despite low knowledge levels, 83% of the people had good attitude and 37% reported good practice. We found a significantly positive correlation among knowledge, attitude and practice (P<0.001). Among the socio-demographic variables, the education level of the participants was an independent predictor of practice level (P<0.05), and education level and interaction between the sex and age group of the participants were independent predictors of attitude level (P<0.05).
Conclusion: Despite the rapid expansion of DENV in Nepal, the knowledge of people about DF was very low. Therefore, massive awareness programmes are urgently required to protect the health of people from DF and to limit its further spread in this country.
The pharmacokinetic properties and tolerability of a triamcinolone acetonide poloxamer 407 hydrogel for intratympanic application were investigated in a guinea pig model. Evaluation of in vivo release kinetics showed very high initial perilymph drug levels, with clinically relevant levels present for a minimum of 10 days. Assessment of auditory brainstem response thresholds showed a minimal, delayed and transient threshold shift, which was apparent on day 3 and resolved by day 10. No relevant histological changes of the middle and inner ear structures were noted, and hair cell counts showed no significant differences between treated and untreated ears. Thus, the triamcinolone-acetonide-loaded poloxamer 407 hydrogel is an effective vehicle for sustained high-dose inner ear glucocorticoid delivery.
In this study prepared for the ECON Committee of the European Parliament, Gellings, Jungbluth and Langenbucher present a graphic overview on core legislation in the area of economic and financial services in Europe. The mapping overview can serve as background for further deliberations. The study covers legislation in force, proposals and other relevant provisions in fourteen policy areas, i.e. banking, securities markets and investment firms, market infrastructure, insurance and occupational pensions, payment services, consumer protection in financial services, the European System of Financial Supervision, European Monetary Union, Euro bills and Coins and statistics, competition, taxation, commerce and company law, accounting and auditing.
This paper contributes to the ongoing debate on the relationship between austerity measures and economic growth. We propose a general equilibrium model where (i) agents have recursive preferences; (ii) economic growth is endogenously driven by investments in R&D; (iii) the government is committed to a zero-deficit policy and finances public expenditures by means of a combination of labor taxes and R&D taxes. We find that austerity measures that rely on reducing resources available to the R&D sector depress economic growth both in the short- and long-run. High debt EU members are currently implementing austerity measures based on higher taxes and/or lower investments in the R&D sector. This casts some doubts on the real ability of these countries to grow over the next years.
The implications of delegating fiscal decision making power to sub-national governments has become an area of significant interest over the past two decades, in the expectation that these reforms will lead to better and more efficient provision of public goods and services. The move towards decentralization has, however, not been homogeneously implemented on the revenue and expenditure side: decentralization has materialized more substantially on the latter than on the former, creating "vertical fiscal imbalances". These imbalances measure the extent to which sub-national governments’ expenditures are financed through their own revenues. This mismatch between own revenues and expenditures may have negative consequences for public finances performance, for example by softening the budget constraint of sub-national governments. Using a large sample of countries covering a long time period from the IMF’s Government Finance Statistics Yearbook, this paper is the first to examine the effects of vertical fiscal imbalances on fiscal performance through the accumulation of government debt. Our findings suggest that vertical fiscal imbalances are indeed relevant in explaining government debt accumulation, and call for a degree of caution when promoting fiscal decentralization.
We develop a model of managerial compensation structure and asset risk choice. The model provides predictions about how inside debt features affect the relation between credit spreads and compensation components. First, inside debt reduces credit spreads only if it is unsecured. Second, inside debt exerts important indirect effects on the role of equity incentives: When inside debt is large and unsecured, equity incentives increase credit spreads; When inside debt is small or secured, this effect is weakened or reversed. We test our model on a sample of U.S. public firms with traded CDS contracts, finding evidence supportive of our predictions. To alleviate endogeneity concerns, we also show that our results are robust to using an instrumental variable approach.
We develop a model of managerial compensation structure and asset risk choice. The model provides predictions about how inside debt features affect the relation between credit spreads and compensation components. First, inside debt reduces credit spreads only if it is unsecured. Second, inside debt exerts important indirect effects on the role of equity incentives: When inside debt is large and unsecured, equity incentives increase credit spreads; When inside debt is small or secured, this effect is weakened or reversed. We test our model on a sample of U.S. public firms with traded CDS contracts, finding evidence supportive of our predictions. To alleviate endogeneity concerns, we also show that our results are robust to using an instrumental variable approach.
The Eurozone fiscal crisis has created pressure for institutional harmonization, but skeptics argue that cultural predispositions can prevent convergence in behavior. Our paper derives a robust cultural classification of European countries and utilizes unique data on natives and immigrants to Sweden. Classification based on genetic distance or on Hofstede’s cultural dimensions fails to identify a single ‘southern’ culture but points to a ‘northern’ culture. Significant differences in financial behavior are found across cultural groups, controlling for household characteristics. Financial behavior tends to converge with longer exposure to common institutions, but is slowed down by longer exposure to original institutions.
This is a chapter for a forthcoming volume Oxford Handbook of Financial Regulation (Oxford University Press 2014) (eds. Eilís Ferran, Niamh Moloney, and Jennifer Payne). It provides an overview of EU financial regulation from the first banking directive up until its most recent developments in the aftermath of the financial crisis, focusing on the multiple layers of multi-level governance and their characteristic conceptual difficulties. Therefore the paper discusses the need to accommodate cross-border capital flows following from the EU internal market and the resulting regulatory strategies. This includes a brief overview of the principle of home country control and the ensuing Financial Services Action Plan. Dealing with the accommodation of cross-border capital flows and their regulation necessarily require an orchestration of the underlying supervisory structures, which is therefore also discussed. In the aftermath of the financial crisis of 2007-09 an additional aspect of necessary orchestration has emerged, that is the need to control systemic risk. Specific attention is paid to microprudential supervision by the newly established European Supervisory Authorities and macroprudential supervision in the European Banking Union, the latter’s underlying drivers and the accompanying Single Supervisory Mechanism, including the SSM’s institutional framework as well as the consideration of its rationales and the Single Resolution Mechanism closely linked to it.
Mathematical modeling of Arabidopsis thaliana with focus on network decomposition and reduction
(2014)
Systems biology has become an important research field during the last decade. It focusses on the understanding of the systems which emit the measured data. An important part of this research field is the network analysis, investigating biological networks. An essential point of the inspection of these network models is their validation, i.e., the successful comparison of predicted properties to measured data. Here especially Petri nets have shown their usefulness as modeling technique, coming with sound analysis methods and an intuitive representation of biological network data.
A very important tool for network validation is the analysis of the Transition-invariants (TI), which represent possible steady-state pathways, and the investigation of the liveness property. The computational complexity of the determination of both, TI and liveness property, often hamper their investigation.
To investigate this issue, a metabolic network model is created. It describes the core metabolism of Arabidopsis thaliana, and it is solely based on data from the literature. The model is too complex to determine the TI and the liveness property.
Several strategies are followed to enable an analysis and validation of the network. A network decomposition is utilized in two different ways: manually, motivated by idea to preserve the integrity of biological pathways, and automatically, motivated by the idea to minimize the number of crossing edges. As a decomposition may not be preserving important properties like the coveredness, a network reduction approach is suggested, which is mathematically proven to conserve these important properties. To deal with the large amount of data coming from the TI analysis, new organizational structures are proposed. The liveness property is investigated by reducing the complexity of the calculation method and adapting it to biological networks.
The results obtained by these approaches suggest a valid network model. In conclusion, the proposed approaches and strategies can be used in combination to allow the validation and analysis of highly complex biological networks.
Cancer is a disease characterized by uncontrolled cell growth and the capacity to disseminate to distant organs. The properties of cancers are caused by genetic and epigenetic alterations when compared to their normal counterparts. Genetic mutations occur in oncogenes and tumor suppressor genes and are the initial drivers of cellular transformation (Lengauer et al., 1998; Vogelstein and Kinzler, 2004). In addition, epigenetic alterations, which influence the expression of oncogenes and tumor suppressor genes independently from sequence alterations, are also involved in the transformation process (Esteller and Herman, 2001; Sharma et al., 2010). Genetic alterations and epigenetic regulatory signals cooperate in tumor etiology. Glioblastoma multiforme (GBM) is a frequent and aggressive malignant brain tumor in humans. The median survival of GBM patients is about 15 months after diagnosis. Like in other cancers, genetic and epigenetic alterations can be detected in GBM. Genetic alterations in GBM affect cell growth, apoptosis, angiogenesis, and invasion; however, epigenetic alterations in GBM also affect the expression of oncogenes or tumor suppresser genes that increase tumor malignancy (Nagarajan and Costello, 2009).
Reprogramming is a cellular process in which somatic cells can be induced to assume the properties of less differentiated stem cells. This process can be mediated through epigenetic modifications of the genome of somatic cells by the action of four defined transcription factors (Oct4, Sox2, Klf4 and Myc) or by the action of the miR 302/367 cluster (Anokye-Danso et al., 2011; Takahashi and Yamanaka, 2006; Takahashi et al., 2007) and result in the generation of induced pluripotent stem cells (iPS cells). Reprogramming of somatic cells by the miR 302/367 cluster can generate nontumorigenic iPS cells through the inhibition of the epithelial to mesenchymal transition (EMT), cell cycle regulatory genes and epigenetic modifiers (Lin and Ying, 2013).
A grammar of Pite Saami
(2014)
Pite Saami is a highly endangered Western Saami language in the Uralic language family currently spoken by a few individuals in Swedish Lapland. This grammar is the first extensive book-length treatment of a Saami language written in English. While focussing on the morphophonology of the main word classes nouns, adjectives and verbs, it also deals with other linguistic structures such as prosody, phonology, phrase types and clauses. Furthermore, it provides an introduction to the language and its speakers, and an outline of a preliminary Pite Saami orthography. An extensive annotated spoken-language corpus collected over the course of five years forms the empirical foundation for this description, and each example includes a specific reference to the corpus in order to facilitate verification of claims made on the data. Descriptions are presented for a general linguistics audience and without attempting to support a specific theoretical approach, but this book should be equally useful for scholars of Uralic linguistics, typologists, and even learners of Pite Saami.
We consider a class of nonautonomous nonlinear competitive parabolic systems on bounded radial domains under Neumann or Dirichlet boundary conditions. We show that, if the initial profiles satisfy a reflection inequality with respect to a hyperplane, then bounded positive solutions are asymptotically (in time) foliated Schwarz symmetric with respect to antipodal points. Additionally, a related result for (positive and sign changing solutions) of scalar equations with Neumann or Dirichlet boundary conditions is given. The asymptotic shape of solutions to cooperative systems is also discussed.
What happened in Cyprus? The economic consequences of the last communist government in Europe
(2014)
This paper reviews developments in the Cypriot economy following the introduction of the euro on 1 January 2008 and leading to the economic collapse of the island five years later. The main cause of the collapse is identified with the election of a communist government in February 2008, within two months of the introduction of the euro, and its subsequent choices for action and inaction on economic policy matters. The government allowed a rapid deterioration of public finances, and despite repeated warnings, damaged the country's creditworthiness and lost market access in May 2011. The destruction of the island's largest power station in July 2011 subsequently threw the economy into recession. Together with the intensification of the euro area crisis in the summer and fall of 2011, these events weakened the banking system which was vulnerable due to its exposure in Greece. Rather than deal with its fiscal crisis, the government secured a loan from the Russian government that allowed it to postpone action until after the February 2013 election. Rather than protect the banking system, losses were imposed on banks and a campaign against them was coordinated and used as a platform by the communist party for the February 2013 election. The strategy succeeded in delaying resolution of the crisis and avoiding short-term political cost for the communist party before the election, but also in precipitating a catastrophe right after the election.
So-called medicanes (Mediterranean hurricanes) are meso-scale, marine, and warm-core Mediterranean cyclones that exhibit some similarities to tropical cyclones. The strong cyclonic winds associated with medicanes threaten the highly populated coastal areas around the Mediterranean basin. To reduce the risk of casualties and overall negative impacts, it is important to improve the understanding of medicanes with the use of numerical models. In this study, we employ an atmospheric limited-area model (COSMO-CLM) coupled with a one-dimensional ocean model (1-D NEMO-MED12) to simulate medicanes. The aim of this study is to assess the robustness of the coupled model in simulating these extreme events. For this purpose, 11 historical medicane events are simulated using the atmosphere-only model, COSMO-CLM, and coupled model, with different setups (horizontal atmospheric grid-spacings of 0.44°, 0.22°, and 0.08°; with/without spectral nudging, and an ocean grid-spacing of 1/12°). The results show that at high-resolution, the coupled model is able to not only simulate most of medicane events but also improve the track length, core temperature, and wind speed of simulated medicanes compared to the atmosphere-only simulations. The results suggest that the coupled model is more proficient for systemic and detailed studies of historical medicane events, and that this model can be an effective tool for future projections.
Background: The aim of this study was to compare outcome of patients with previous cardiac surgery undergoing transapical aortic valve implantation (Redo-TAVI) to those undergoing classic aortic valve replacement (Redo-AVR) by using propensity analysis.
Methods: From January 2005 through May 2012, 52 high-risk patients underwent Redo-TAVI using a pericardial xenograft fixed within a stainless steel, balloon-expandable stent (Edwards SAPIEN™). During the same period of time 167 patients underwent classic Redo-AVR. Logistic regression analysis was used to identify covariates among 11 baseline patient variables including the type of initial surgery. Using the significant regression coefficients, each patient’s propensity score was calculated, allowing selectively matched subgroups of 40 patients each. Initial surgery included coronary artery bypass grafting in 30 patients, aortic valve replacement in 7 patients and mitral valve reconstruction in 3 patients in each group. Follow-up was 4 ± 2 years and was 100% complete.
Results: Postoperative chest tube drainage (163 ± 214 vs. 562 ± 332 ml/24 h, p = 0.02) and incidence of early permanent neurologic deficit (0 vs. 13%, p = 0.04) was lower in patients with Redo-TAVI and there was a trend towards improved 30-day survival (p = 0.06). Also we detected a decreased ventilation time (p = 0.04) and lower transfusion rate of allogenic blood products (p ≤ 0.05) in the Redo-TAVI group. At late follow up differences regarding incidence of major adverse events, including death and permanent neurologic deficits (25% vs. 43%, p = 0.01) statistically supported early postoperative findings.
Conclusion: The encouraging results regarding early and long-term outcomes following TAVI in patients with previous cardiac surgery show, that this evolving approach may be particularly beneficial in this patient cohort.
The role of RNA interference in the developmental separation of blood and lymphatic vasculature
(2014)
Background: Dicer is an RNase III enzyme that cleaves double stranded RNA and generates functional interfering RNAs that act as important regulators of gene and protein expression. Dicer plays an essential role during mouse development because the deletion of the dicer gene leads to embryonic death. In addition, dicer-dependent interfering RNAs regulate postnatal angiogenesis. However, the role of dicer is not yet fully elucidated during vascular development.
Methods: In order to explore the functional roles of the RNA interference in vascular biology, we developed a new constitutive Cre/loxP-mediated inactivation of dicer in tie2 expressing cells.
Results: We show that cell-specific inactivation of dicer in Tie2 expressing cells does not perturb early blood vessel development and patterning. Tie2-Cre; dicerfl/fl mutant embryos do not show any blood vascular defects until embryonic day (E)12.5, a time at which hemorrhages and edema appear. Then, midgestational lethality occurs at E14.5 in mutant embryos. The developing lymphatic vessels of dicer-mutant embryos are filled with circulating red blood cells, revealing an impaired separation of blood and lymphatic vasculature.
Conclusion: Thus, these results show that RNA interference perturbs neither vasculogenesis and developmental angiogenesis, nor lymphatic specification from venous endothelial cells but actually provides evidence for an epigenetic control of separation of blood and lymphatic vasculature.
The recent approval by the US Food and Drug Administration of ocriplasmin for the treatment of symptomatic vitreomacular adhesion (VMA), often associated with vitreomacular traction (VMT) and macular hole (MH), has brought new attention to the field of pharmacologic vitreolysis. The need for an enzyme to split the vitreomacular interface, which is formed by a strong adhesive interaction between the posterior vitreous cortex and the internal limiting membrane, historically stems from pediatric eye surgery. This review summarizes the different anatomic classifications of posterior vitreous detachment or anomalous posterior vitreous detachment and puts these in the context of clinical pathologies commonly observed in clinical practice of the vitreoretinal specialist, such as MH, VMT, age-related macular degeneration, and diabetic macular edema. We revisit the outcome of the Phase II studies that indicated ocriplasmin was a safe and effective treatment for selected cases of symptomatic VMA and MH. Release of VMA at day 28 was achieved by 26.5% of patients in the ocriplasmin group versus 10.1% in the placebo group (P<0.001). Interestingly, for MHs, the numbers were more remarkable. Predictive factors for successful ocriplasmin treatment were identified for VMT (VMA diameter smaller than 1,500 µm) and MH (smaller than 250 µm). In comparison with the highly predictable outcome after vitrectomy, the general success rate of ocriplasmin not under clinical trial conditions has not fully met expectations and needs to be proven in real-world clinical settings. The ocriplasmin data will be compared in the future with observational data on spontaneous VMA release, will help retina specialists make more accurate predictions, and will improve outcome rates.