145 research outputs found
Residential mobility and local housing-market differences
The authors extend previous literature on variations in mobility rates across local housing markets by examining the linkage of mobility rates at the household level to the structure of local housing markets. The results suggest that residential mobility rates differ widely across local housing markets, substantiating the view that residential relocation is intimately intertwined with conditions at the local level. Local housing-market conditions also have different effects on mobility rates for renters and owner-occupiers. The results suggest that variation in residential mobility rates across housing markets can be in part explained by level of urbanization, the tenure structure, the degree of government intervention, and the size of the housing market. Remarkably, these differences in local housing markets cannot be seen to be related to housing-market features only. The results suggest that these differences can also be attributed to the behavior or attitude of households with respect to housing
The State of the Art in Language Workbenches. Conclusions from the Language Workbench Challenge
Language workbenches are tools that provide high-level mechanisms for the implementation of (domain-specific) languages. Language workbenches are an active area of research that also receives many contributions from industry. To compare and discuss existing language workbenches, the annual Language Workbench Challenge was launched in 2011. Each year, participants are challenged to realize a given domain-specific language with their workbenches as a basis for discussion and comparison. In this paper, we describe the state of the art of language workbenches as observed in the previous editions of the Language Workbench Challenge. In particular, we capture the design space of language workbenches in a feature model and show where in this design space the participants of the 2013 Language Workbench Challenge reside. We compare these workbenches based on a DSL for questionnaires that was realized in all workbenches
HIV Types, Groups, Subtypes and Recombinant Forms: Errors in Replication, Selection Pressure and Quasispecies
HIV-1 is a chimpanzee virus which was transmitted to humans by several zoonotic events resulting in infection with HIV-1 groups M P, and in parallel transmission events from sooty mangabey monkey viruses leading to infections with HIV-2 groups A H. Both viruses have circulated in the human population for about 80 years. In the infected patient, HIV mutates, and by elimination of some of the viruses by the action of the immune system individual quasispecies are formed. Along with the selection of the fittest viruses, mutation and recombination after superinfection with HIV from different groups or subtypes have resulted in the diversity of their patterns of geographic distribution. Despite the high variability observed, some essential parts of the HIV genome are highly conserved. Viral diversity is further facilitated in some parts of the HIV genome by drug selection pressure and may also be enhanced by different genetic factors, including HLA in patients from different regions of the world. Viral and human genetic factors influence pathogenesis. Viral genetic factors are proteins such as Tat, Vif and Rev. Human genetic factors associated with a better clinical outcome are proteins such as APOBEC, langerin, tetherin and chemokine receptor 5 (CCR5) and HLA B27, B57, DRB1{*}1303, KIR and PARD3B. Copyright (C) 2012 S. Karger AG, Base
On the State Complexity of Partial Derivative Automata For Regular Expressions with Intersection
Extended regular expressions (with complement and intersection) are used in many applications due to their succinctness. In particular, regular expressions extended with intersection only (also called semi-extended) can already be exponentially smaller than standard regular expressions or equivalent nondeterministic finite automata (NFA). For practical purposes it is important to study the average behaviour of conversions between these models. In this paper, we focus on the conversion of regular expressions with intersection to nondeterministic finite automata, using partial derivatives and the notion of support. First, we give a tight upper bound of 2O(n) for the worst-case number of states of the resulting partial derivative automaton, where n is the size of the expression. Using the framework of analytic combinatorics, we then establish an upper bound of (1.056 + o(1))n for its asymptotic average-state complexity, which is significantly smaller than the one for the worst case. (c) IFIP International Federation for Information Processing 2016
Enhancement of Polymeric Immunoglobulin Receptor Transcytosis by Biparatopic VHH
The polymeric immunoglobulin receptor (pIgR) ensures the transport of dimeric immunoglobulin A (dIgA) and pentameric immunoglobulin M (pIgM) across epithelia to the mucosal layer of for example the intestines and the lungs via transcytosis. Per day the human pIgR mediates the excretion of 2 to 5 grams of dIgA into the mucosa of luminal organs. This system could prove useful for therapies aiming at excretion of compounds into the mucosa. Here we investigated the use of the variable domain of camelid derived heavy chain only antibodies, also known as VHHs or Nanobodies®, targeting the human pIgR, as a transport system across epithelial cells. We show that VHHs directed against the human pIgR are able to bind the receptor with high affinity (∼1 nM) and that they compete with the natural ligand, dIgA. In a transcytosis assay both native and phage-bound VHH were only able to get across polarized MDCK cells that express the human pIgR gene in a basolateral to apical fashion. Indicating that the VHHs are able to translocate across epithelia and to take along large particles of cargo. Furthermore, by making multivalent VHHs we were able to enhance the transport of the compounds both in a MDCK-hpIgR and Caco-2 cell system, probably by inducing receptor clustering. These results show that VHHs can be used as a carrier system to exploit the human pIgR transcytotic system and that multivalent compounds are able to significantly enhance the transport across epithelial monolayers
Exosomes derived from mesenchymal stem cells enhance radiotherapy-induced cell death in tumor and metastatic tumor foci
We have recently shown that radiotherapy may not only be a successful local and regional treatment
but, when combined with MSCs, may also be a novel systemic cancer therapy. This study aimed to investigate the
role of exosomes derived from irradiated MSCs in the delay of tumor growth and metastasis after treatment with
MSC + radiotherapy (RT). The tumor cell loss rates found after treatment with the combination of MSC and RT and for exclusive RT, were:
44.4% % and 12,1%, respectively. Concomitant and adjuvant use of RT and MSC, increased the mice surviving time 22,5%
in this group, with regard to the group of mice treated with exclusive RT and in a 45,3% respect control group. Moreover,
the number of metastatic foci found in the internal organs of the mice treated with MSC + RT was 60% less than the
mice group treated with RT alone. We reasoned that the exosome secreted by the MSC, could be implicated in tumor
growth delay and metastasis control after treatment. Our results show that exosomes derived form MSCs, combined with radiotherapy, are determinant in
the enhancement of radiation effects observed in the control of metastatic spread of melanoma cells and suggest that
exosome-derived factors could be involved in the bystander, and abscopal effects found after treatment of the tumors
with RT plus MSC. Radiotherapy itself may not be systemic, although it might contribute to a systemic effect when used
in combination with mesenchymal stem cells owing the ability of irradiated MSCs-derived exosomes to increase the
control of tumor growth and metastasis.This work was supported by CNPq, Conselho Nacional de
Desenvolvimento CientÃfico e Tecnológico – Brasil, Junta de AndalucÃa,
project of Excellence from Junta de AndalucÃa P12-CTS-383 to FJO, Spanish
Ministry of Economy and Competitiveness SAF2015-70520-R to FJO and
JMRdA, RTICC RD12/0036/0026 and CIBER Cáncer ISCIII CB16/12/00421 to
FJO
- …