286 research outputs found
WWOX at the crossroads of cancer, metabolic syndrome related traits and CNS pathologies
WWOX was cloned as a putative tumor suppressor gene mapping to chromosomal fragile site FRA16D. Deletions affecting WWOX accompanied by loss of expression are frequent in various epithelial cancers. Translocations and deletions affecting WWOX are also common in multiple myeloma and are associated with worse prognosis. Metanalysis of gene expression datasets demonstrates that low WWOX expression is significantly associated with shorter relapse-free survival in ovarian and breast cancer patients. Although somatic mutations affecting WWOX are not frequent, analysis of TCGA tumor datasets led to identifying 44 novel mutations in various tumor types. The highest frequencies of mutations were found in head and neck cancers and uterine and gastric adenocarcinomas. Mouse models of gene ablation led us to conclude that Wwox does not behave as a highly penetrant, classical tumor suppressor gene since its deletion is not tumorigenic in most models and its role is more likely to be of relevance in tumor progression rather than in initiation. Analysis of signaling pathways associated with WWOX expression confirmed previous in vivo and in vitro observations linking WWOX function with the TGFβ/SMAD and WNT signaling pathways and with specific metabolic processes. Supporting these conclusions recently we demonstrated that indeed WWOX behaves as a modulator of TGFβ/SMAD signaling by binding and sequestering SMAD3 in the cytoplasmic compartment. As a consequence progressive loss of WWOX expression in advanced breast cancer would contribute to the pro-metastatic effects resulting from TGFβ/SMAD3 hyperactive signaling in breast cancer.Recently, GWAS and resequencing studies have linked the WWOX locus with familial dyslipidemias and metabolic syndrome related traits. Indeed, gene expression studies in liver conditional KO mice confirmed an association between WWOX expression and lipid metabolism.Finally, very recently the first human pedigrees with probands carrying homozygous germline loss of function WWOX mutations have been identified. These patients are characterized by severe CNS related pathology that includes epilepsy, ataxia and mental retardation. In summary, WWOX is a highly conserved and tightly regulated gene throughout evolution and when defective or deregulated the consequences are important and deleterious as demonstrated by its association not only with poor prognosis in cancer but also with other important human pathologies such as metabolic syndrome and CNS related pathologic conditions.Centro de Investigaciones Inmunológicas Básicas y Aplicada
WWOX at the crossroads of cancer, metabolic syndrome related traits and CNS pathologies
WWOX was cloned as a putative tumor suppressor gene mapping to chromosomal fragile site FRA16D. Deletions affecting WWOX accompanied by loss of expression are frequent in various epithelial cancers. Translocations and deletions affecting WWOX are also common in multiple myeloma and are associated with worse prognosis. Metanalysis of gene expression datasets demonstrates that low WWOX expression is significantly associated with shorter relapse-free survival in ovarian and breast cancer patients. Although somatic mutations affecting WWOX are not frequent, analysis of TCGA tumor datasets led to identifying 44 novel mutations in various tumor types. The highest frequencies of mutations were found in head and neck cancers and uterine and gastric adenocarcinomas. Mouse models of gene ablation led us to conclude that Wwox does not behave as a highly penetrant, classical tumor suppressor gene since its deletion is not tumorigenic in most models and its role is more likely to be of relevance in tumor progression rather than in initiation. Analysis of signaling pathways associated with WWOX expression confirmed previous in vivo and in vitro observations linking WWOX function with the TGFβ/SMAD and WNT signaling pathways and with specific metabolic processes. Supporting these conclusions recently we demonstrated that indeed WWOX behaves as a modulator of TGFβ/SMAD signaling by binding and sequestering SMAD3 in the cytoplasmic compartment. As a consequence progressive loss of WWOX expression in advanced breast cancer would contribute to the pro-metastatic effects resulting from TGFβ/SMAD3 hyperactive signaling in breast cancer.Recently, GWAS and resequencing studies have linked the WWOX locus with familial dyslipidemias and metabolic syndrome related traits. Indeed, gene expression studies in liver conditional KO mice confirmed an association between WWOX expression and lipid metabolism.Finally, very recently the first human pedigrees with probands carrying homozygous germline loss of function WWOX mutations have been identified. These patients are characterized by severe CNS related pathology that includes epilepsy, ataxia and mental retardation. In summary, WWOX is a highly conserved and tightly regulated gene throughout evolution and when defective or deregulated the consequences are important and deleterious as demonstrated by its association not only with poor prognosis in cancer but also with other important human pathologies such as metabolic syndrome and CNS related pathologic conditions.Centro de Investigaciones Inmunológicas Básicas y Aplicada
Habitable Zones of Host Stars During the Post-MS Phase
A star will become brighter and brighter with stellar evolution, and the
distance of its habitable zone will become farther and farther. Some planets
outside the habitable zone of a host star during the main sequence phase may
enter the habitable zone of the host star during other evolutionary phases. A
terrestrial planet within the habitable zone of its host star is generally
thought to be suited to life existence. Furthermore, a rocky moon around a
giant planet may be also suited to life survive, provided that the planet-moon
system is within the habitable zone of its host star. Using Eggleton's code and
the boundary flux of habitable zone, we calculate the habitable zone of our
Solar after the main sequence phase. It is found that Mars' orbit and Jupiter's
orbit will enter the habitable zone of Solar during the subgiant branch phase
and the red giant branch phase, respectively. And the orbit of Saturn will
enter the habitable zone of Solar during the He-burning phase for about 137
million years. Life is unlikely at any time on Saturn, as it is a giant gaseous
planet. However, Titan, the rocky moon of Saturn, may be suitable for
biological evolution and become another Earth during that time. For low-mass
stars, there are similar habitable zones during the He-burning phase as our
Solar, because there are similar core masses and luminosities for these stars
during that phase.Comment: 6 pages, 7 figures. Accepted by Ap & S
Scaling of stochasticity in dengue hemorrhagic fever epidemics
In this paper we analyze the stochastic version of a minimalistic multi-strain model,
which captures essential differences between primary and secondary infections in dengue
fever epidemiology, and investigate the interplay between stochasticity, seasonality and
import. The introduction of stochasticity is needed to explain the fluctuations observed
in some of the available data sets, revealing a scenario where noise and complex
deterministic skeleton strongly interact. For large enough population size, the stochastic
system can be well described by the deterministic skeleton gaining insight on the relevant
parameter values purely on topological information of the dynamics, rather than classical
parameter estimation of which application is in general restricted to fairly simple
dynamical scenarios
Habitable Zones and UV Habitable Zones around Host Stars
Ultraviolet radiation is a double-edged sword to life. If it is too strong,
the terrestrial biological systems will be damaged. And if it is too weak, the
synthesis of many biochemical compounds can not go along. We try to obtain the
continuous ultraviolet habitable zones, and compare the ultraviolet habitable
zones with the habitable zones of host stars. Using the boundary ultraviolet
radiation of ultraviolet habitable zone, we calculate the ultraviolet habitable
zones of host stars with masses from 0.08 to 4.00 \mo. For the host stars with
effective temperatures lower than 4,600 K, the ultraviolet habitable zones are
closer than the habitable zones. For the host stars with effective temperatures
higher than 7,137 K, the ultraviolet habitable zones are farther than the
habitable zones. For hot subdwarf as a host star, the distance of the
ultraviolet habitable zone is about ten times more than that of the habitable
zone, which is not suitable for life existence.Comment: 5 pages, 3 figure
Genetic diversity among farmer-preferred cassava landraces in Uganda
Understanding of genetic diversity among a breeding population is an
important requirement for crop improvement as it allows for the
selection of diverse parental combinations and formation of heterotic
pools for genetic gain. This study was carried out to determine genetic
diversity within and among 51 farmer-preferred cassava ( Manihot
esculenta ) landraces and 15 elite accessions grown in Uganda. Twenty
six simple sequence repeat (SSR) markers used for genetic diversity
assessment in this study revealed a total of 154 alleles, of which 24%
were unique alleles present only in landraces. The genetic diversity
and observed herozygosity in landraces were slightly higher than in
elite accessions. Elite accessions clustered with some of the landraces
indicating that there were some alleles in common. However, 58.8% of
the landraces fell into 3 different clusters independent of the elite
accessions. Including these landraces with unique alleles in cassava
breeding schemes will increase the chances of producing farmer
preferred adapted elite cultivars. The study also revealed genetic
differentiation among accessions from different regions providing an
opportunity for establishment of heterotic pools within a breeding
programme.La compr\ue9hension de la diversit\ue9 g\ue9n\ue9tique est une
condition importante dans la s\ue9lection de diverses combinaisons
parentales et la formation des groupes h\ue9terotiques
d\u2019int\ue9r\ueat g\ue9n\ue9tique pour
l\u2019am\ue9lioration des cultures. Cette \ue9tude \ue9tait
conduite pour d\ue9terminer la diversit\ue9 g\ue9n\ue9tique
parmi 51 vari\ue9t\ue9s locales de manioc ( Manihot esculenta )
pr\ue9f\ue9r\ue9es des fermiers et 15 accessions \ue9lites
cultiv\ue9es en Ouganda. Vingt six marqueurs simples \ue0 sequence
r\ue9p\ue9t\ue9e (SSR) utilis\ue9s pour l\u2019\ue9valuation
de la diversit\ue9 g\ue9n\ue9tique ont r\ue9v\ue9l\ue9 un
total de 154 all\ue8les, parmi lesquelles 24% \ue9taient des
all\ue8les uniques pr\ue9sentes dans les races locales seulement.
La diversit\ue9 g\ue9n\ue9tique et
l\u2019h\ue9terozygosit\ue9 observ\ue9es dans les races locales
\ue9taient l\ue9g\ue8rement sup\ue9rieures que dans les
accessions \ue9lites. Celles-ci s\u2019\ue9taient regroup\ue9es
avec quelques vari\ue9t\ue9s locales indiquant donc qu\u2019elles
avaient quelques all\ue8les en commun. Par ailleurs, 58.8% des races
locales ont form\ue9 trois diff\ue9rents groupes
ind\ue9pendamment des accessions \ue9lites. Inclure ces races
locales \ue0 all\ue8les uniques dans les syst\ue8mes
d\u2019am\ue9lioration du manioc permettra d\u2019augmenter les
chances de produire des cultivars \ue9lites pr\ue9f\ue9r\ue9s
des fermiers. L\u2019\ue9tude montre aussi que la
diff\ue9renciation g\ue9n\ue9tique trouv\ue9e parmi les
accessions de diff\ue9rentes r\ue9gions est une opportunit\ue9
offerte pour l\u2019\ue9tablissement des groupes h\ue9terotiques
dans le programme d\u2019am\ue9lioration
O teor de cálcio na casca é indicativo da suscetibilidade ao "bitter pit" em maçãs 'fuji'
Predição de "bitter pit" em maçãs 'gala' Por meio da infiltração dos frutos com magnésio
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
- …