Search results for "Polymers."
showing 10 items of 3543 documents
Urban-rural Interactions in Latvia
2010
Policies and plans for rural areas tend to start by assuming that they are separate and distinctive from urban areas, and that this distinctiveness is more important than any of their other characteristics. Laila Kule argues that this introduces an unwelcome hierarchy in regional development priorities, and shows how Latvia has attempted to build on connectivity rather than difference in urban-rural development.
Silk-based matrices and c-Kit positive cardiac progenitor cells for a cellularized silk fibroin scaffold: study of an in vivo model.
2022
The production of a cellularized silk fibroin scaffold is very difficult because it is actually impossible to differentiate cells into a well-organized cardiac tissue. Without vascularization, not only do cell masses fail to grow, but they may also exhibit an area of necrosis, indicating a lack of oxygen and nutrients. In the present study, we used the so-called tyrosine protein kinase kit (c-kit)-positive cardiac progenitor cells (CPCs) to generate cardiac cellularized silk fibroin scaffolds, multipotent cells isolated from the adult heart to date that can show some degree of differentiation toward the cardiac phenotype. To test their ability to differentiate into the cardiac phenotype in …
Is large-scale rapid CoV-2 testing a substitute for lockdowns?
2021
Background Various forms of contact restrictions have been adopted in response to the Covid-19 pandemic. Around February 2021, rapid testing appeared as a new policy instrument. Some claim it may serve as a substitute for contact restrictions. We study the strength of this argument by evaluating the effects of a unique policy experiment: In March and April 2021, the city of Tübingen set up a testing scheme while relaxing contact restrictions. Methods We compare case rates in Tübingen county to an appropriately identified control unit. We employ the synthetic control method. We base interpretations of our findings on an extended SEIR model. Findings The experiment led to an increase in the …
B Cell Expansion Hinders the Stroma-Epithelium Regenerative Crosstalk During Mucosal Healing
2021
Little is known about the pro-resolution role of immune cells recruited to damaged tissue. Using an experimental model of intestinal epithelial damage and repair, we identified B cells as the dominant cell type in the healing colon. Single-cell RNA-sequencing (scRNAseq) revealed the expansion of an IFN-induced B cell subset during experimental mucosal healing which was associated with colitis severity. In line with this, B cell depletion during mucosal healing resulted in accelerated recovery upon injury, which was associated with enhanced expression of tissue remodeling genes. scRNA-seq from the epithelial and stromal compartment confirmed that lack of B cells during mucosal healing alters…
An International Comparison of Skills, Traits and Job Mobility
2019
Making use of an international survey that directly assesses the cognitive skills of the adult population, I document systematic differences in the effect of skills on job mobility across the 37 countries in the sample. While economic growth is associated with relatively higher job mobility among skilled workers, the prevalence of information and communication technology (ICT) in the workplace is associated with relatively lower job mobility. The documented patterns are in line with Schumpeterian growth models of creative destruction in which skilled workers transition to jobs with advanced technologies more easily.
Minimal Dynamic Equilibria
2018
We define dynamic models as multiperiod models with no static representations and demonstrate that current prevalent asset pricing empirical implementations are inconsistent with dynamic equilibria. Specifically, empirical implementations are misspecified with respect to three essential asset pricing questions (TEQ): dependency on higher moments, complexity of risk premia, and mean-variance efficiency of the “market portfolio” (ability to proxy pricing kernels/SDFs). While we already know that “Merton” models, and their derivatives, differ from static models in all TEQ, we show that this is the case even the “minimal” dynamic equilibria.
The Value of Auditor Industry Specialization: Evidence from a Structural Model
2021
ABSTRACT This study investigates the value of auditor industry specialization. In the first step, we use a discrete choice model to derive the first-order demand for auditor industry specialization. Our results reveal that clients have a general preference for auditor industry specialization, relating to both audit firm and audit office specialization. We observe that specializations at the audit firm and audit office level are substitutes. We also find that larger, more complex clients have a stronger demand for industry specialization at the audit office level. In the second step, we use the results from the discrete choice model to quantify the value of auditor industry specialists for c…
Fear Sells: Determinants of Fund-Raising Success in the cross-section of Initial Coin Offerings
2021
This paper explores cross-sectionally the determinants of ICO success as measured by the amount of raised funding. Our study is the first that retrieves an intensive hand-collected data library covering the entire population of all 5,033 ICOs launched in the 2014 – 2019 period. Another important novel aspect is that we address the question whether psychological and financial sentiment cached in whitepapers have an impact on the success of ICOs. We employ natural language procession tools and various sentiment dictionaries to assess the sentiment in whitepapers and our results suggest that ICO investors are largely guided by their emotions when making investment decisions. Additionally, to g…
Effect of organic loading rate on the production of Polyhydroxyalkanoates from sewage sludge
2023
The aim of this work was to study the effect of organic loading rate on the production of Polyhydroxyalkanoates (PHA) from sewage sludge. Synthesis of PHA using sewage sludge as platform was achieved in this work. Three pilot-scale selection-sequencing batch reactors (S-SBR) were used for obtaining a culture able to accumulate PHA following a strategy of aerobic dynamic feeding (ADF) at different volumetric organic-loading-rate (vOLR): 1.3, 1.8 and 0.8 g COD L-1 d-1 for S-SBR 1, S-SBR 2 and S-SBR 3, respectively. Decreasing the vOLR enhanced the general performance of the process as for organic matter removal (from 99.2% ± 0.3% in S-SBR-3 to 92 ± 2 in S-SBR-2) while the opposite trend was r…
Ambient Temperature, Social Perception and Social Behavior
2020
The literature suggests that human perception and behavior vary with physical temperature. We provide an experimental test of how different ambient temperature conditions impact social behavior and social perception: Subjects went through a series of tasks measuring various aspects of social behavior and perception under three temperature conditions (cold vs. optimal vs. warm). Despite well-established findings on temperature effects, our data suggest that physical temperature has no relevant influence on social behavior and social perception. We corroborate our finding of a null effect by the use of equivalence testing and provide a discussion in the light of recent failed replication atte…