5,639 research outputs found
A Placenta Derived C-Terminal Fragment of beta-Hemoglobin With Combined Antibacterial and Antiviral Activity
Age effect on retina and optic disc normal values
Purpose:
To investigate retinal thickness and optic disc parameters by the Retinal Thickness Analyzer (RTA) glaucoma program in older normal subjects and to determine any age effect.
Methods:
Subjects over 40 years of age without any prior history of eye diseases were recruited. Only subjects completely normal on clinical ophthalmologic examination and on visual field testing by Humphrey Field Analyzer (HFA) using the SITA 24-2 program were included. A total of 74 eyes from 74 subjects with even age distribution over the decades were enrolled and underwent topographic measurements of the posterior pole and of the optic disc by RTA. The `glaucoma full' program in software version 4.11B was applied.
Results:
Mean patient age was 59.9 +/- 10.3 years with a range from 40 to 80 years. The only parameter intraocular pressure (IOP) correlated with was retinal posterior pole asymmetry (r=0.27, p=0.02). IOP itself increased significantly with age (r=0.341, p=0.003). Mean defect and pattern standard deviation of the HFA did not correlate with any of the retinal or optic disc measurements. Increasing age correlated significantly with some of the morphologic measurements of the RTA: decreasing perifoveal minimum thickness (r=-0.258, p=0.026), increased cup-to-disc area ratio (r=0.302, p=0.016) and increased cup area (r=0.338 p=0.007).
Conclusions:
An age effect exists for some of the retina and optic disc measurements obtained by the RTA. Copyright (C) 2005 S. Karger AG, Basel
Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population
Mineral nutrient malnutrition, and particularly
deficiency in zinc and iron, afflicts over 3 billion people
worldwide. Wild emmer wheat, Triticum turgidum ssp.
dicoccoides, genepool harbors a rich allelic repertoire for
mineral nutrients in the grain. The genetic and physiological
basis of grain protein, micronutrients (zinc, iron,
copper and manganese) and macronutrients (calcium,
magnesium, potassium, phosphorus and sulfur) concentration
was studied in tetraploid wheat population of 152
recombinant inbred lines (RILs), derived from a cross
between durum wheat (cv. Langdon) and wild emmer
(accession G18-16). Wide genetic variation was found
among the RILs for all grain minerals, with considerable
transgressive effect. A total of 82 QTLs were mapped for
10 minerals with LOD score range of 3.2–16.7. Most QTLs
were in favor of the wild allele (50 QTLs). Fourteen pairs
of QTLs for the same trait were mapped to seemingly
homoeologous positions, reflecting synteny between the A
and B genomes. Significant positive correlation was found
between grain protein concentration (GPC), Zn, Fe and Cu,
which was supported by significant overlap between the
respective QTLs, suggesting common physiological and/or
genetic factors controlling the concentrations of these
mineral nutrients. Few genomic regions (chromosomes 2A,
5A, 6B and 7A) were found to harbor clusters of QTLs for
GPC and other nutrients. These identified QTLs may
facilitate the use of wild alleles for improving grain
nutritional quality of elite wheat cultivars, especially in
terms of protein, Zn and Fe
Liver transplantation in cirrhotic patients with diabetes mellitus: Midterm results, survival, and adverse events
Liver cirrhosis is frequently associated with diabetes mellitus (DM), and this
metabolic complication is also frequent after orthotopic liver transplantation
(OLT). The aim of our study is to investigate which factors are associated with
DM before and after OLT and their impact on post-OLT evolution. We evaluated the
prevalence of DM among 115 liver transplant candidates with cirrhosis and
assessed their evolution after OLT (median follow-up, 41 months). Sixteen
candidates had DM requiring pharmacological therapy (group A), 45 candidates had
DM controlled with diet (group B), and 54 candidates did not have DM (group C).
One-year and 3-year actuarial survival rates were 100% and 100% for group A, 91%
and 85% for group B, and 77% and 74% for group C, respectively (P <.03). Post-OLT
DM was more frequent in group A. The incidence of other metabolic complications,
major infections, rejection, and arterial hypertension; the need for
hospitalization; and renal and graft function of patients in groups A, B, and C
were similar. The only risk factor for DM 1 year after OLT on multivariate
analysis was pre-OLT DM requiring pharmacological treatment. The incidence of
complications, need for hospitalization, and renal and graft function 1 year
after OLT for patients with post-OLT DM were similar to those of patients without
post-OLT DM. In conclusion, patients with cirrhosis who have DM have a greater
risk for post-OLT DM, but their midterm survival is not worse than the survival
of those without DM
A Comprehensive Analysis of Choroideremia: From Genetic Characterization to Clinical Practice.
Choroideremia (CHM) is a rare X-linked disease leading to progressive retinal degeneration resulting in blindness. The disorder is caused by mutations in the CHM gene encoding REP-1 protein, an essential component of the Rab geranylgeranyltransferase (GGTase) complex. In the present study, we evaluated a multi-technique analysis algorithm to describe the mutational spectrum identified in a large cohort of cases and further correlate CHM variants with phenotypic characteristics and biochemical defects of choroideremia patients. Molecular genetic testing led to the characterization of 36 out of 45 unrelated CHM families (80%), allowing the clinical reclassification of four CHM families. Haplotype reconstruction showed independent origins for the recurrent p.Arg293* and p.Lys178Argfs*5 mutations, suggesting the presence of hotspots in CHM, as well as the identification of two different unrelated events involving exon 9 deletion. No certain genotype-phenotype correlation could be established. Furthermore, all the patients´ fibroblasts analyzed presented significantly increased levels of unprenylated Rabs proteins compared to control cells; however, this was not related to the genotype. This research demonstrates the major potential of the algorithm proposed for diagnosis. Our data enhance the importance of establish a differential diagnosis with other retinal dystrophies, supporting the idea of an underestimated prevalence of choroideremia. Moreover, they suggested that the severity of the disorder cannot be exclusively explained by the genotype
Sinks in the Landscape, Boltzmann Brains, and the Cosmological Constant Problem
This paper extends the recent investigation of the string theory landscape in
hep-th/0605266, where it was found that the decay rate of dS vacua to a
collapsing space with a negative vacuum energy can be quite large. The parts of
space that experience a decay to a collapsing space, or to a Minkowski vacuum,
never return back to dS space. The channels of irreversible vacuum decay serve
as sinks for the probability flow. The existence of such sinks is a
distinguishing feature of the string theory landscape. We describe relations
between several different probability measures for eternal inflation taking
into account the existence of the sinks. The local (comoving) description of
the inflationary multiverse suffers from the so-called Boltzmann brain (BB)
problem unless the probability of the decay to the sinks is sufficiently large.
We show that some versions of the global (volume-weighted) description do not
have this problem even if one ignores the existence of the sinks. We argue that
if the number of different vacua in the landscape is large enough, the
anthropic solution of the cosmological constant problem in the string landscape
scenario should be valid for a broad class of the probability measures which
solve the BB problem. If this is correct, the solution of the cosmological
constant problem may be essentially measure-independent. Finally, we describe a
simplified approach to the calculations of anthropic probabilities in the
landscape, which is less ambitious but also less ambiguous than other methods.Comment: 42 pages, 5 figures, the paper is substantially extended, a section
on the cosmological constant is addeed; the version published in JCA
Inflation with racetrack superpotential and matter field
Several models of inflation with the racetrack superpotential for the volume
modulus coupled to a matter field are investigated. In particular, it is shown
that two classes of racetrack inflation models, saddle point and inflection
point ones, can be constructed in a fully supersymmetric framework with the
matter field F-term as a source of supersymmetry breaking and uplifting. Two
models of F-term supersymmetry breaking are considered: the Polonyi model and
the quantum corrected O'Raifeartaigh model. In the former case, both classes of
racetrack inflation models differ significantly from the corresponding models
with non-supersymmetric uplifting. The main difference is a quite strong
dominance of the inflaton by the matter field. In addition, fine-tuning of the
parameters is relaxed as compared to the original racetrack models. In the case
of the racetrack inflation models coupled to the O'Raifeartaigh model, the
matter field is approximately decoupled from the inflationary dynamics. In all
of the above models the gravitino mass is larger than the Hubble scale during
inflation. The possibility of having the gravitino much lighter than the Hubble
scale is also investigated. It is very hard to construct models with light
gravitino in which the volume modulus dominates inflation. On the other hand,
models in which the inflationary dynamics is dominated by the matter field are
relatively simple and seem to be more natural.Comment: 40 pages, 13 figures, references added, typos corrected, version to
be publishe
A gene-alteration profile of human lung cancer cell lines
ABSTRACT: Aberrant proteins encoded from genes altered
in tumors drive cancer development and may also be
therapeutic targets. Here we derived a comprehensive
gene-alteration profile of lung cancer cell lines. We tested
17 genes in a panel of 88 lung cancer cell lines and found
the rates of alteration to be higher than previously thought.
Nearly all cells feature inactivation at TP53 and CDKN2A
or RB1, whereas BRAF, MET, ERBB2, and NRAS
alterations were infrequent. A preferential accumulation
of alterations among histopathological types and a mutually
exclusive occurrence of alterations of CDKN2A and RB1
as well as of KRAS, epidermal growth factor receptor
(EGFR), NRAS, and ERBB2 were seen. Moreover, in nonsmall-
cell lung cancer (NSCLC), concomitant activation of
signal transduction pathways known to converge in
mammalian target of rapamycin (mTOR) was common.
Cells with single activation of ERBB2, PTEN, or MET
signaling showed greater sensitivity to cell-growth inhibition
induced by erlotinib, LY294002, and PHA665752,
respectively, than did cells featuring simultaneous activation
of these pathways, underlining the need for combined
therapeutic strategies in targeted cancer treatments. In
conclusion, our gene-alteration landscape of lung cancer
cell lines provides insights into how gene alterations
accumulate and biological pathways interact in cancer.
Hum Mutat 30, 1199–1206, 2009. & 2009Wiley-Liss, Inc
Testing String Theory with CMB
Future detection/non-detection of tensor modes from inflation in CMB
observations presents a unique way to test certain features of string theory.
Current limit on the ratio of tensor to scalar perturbations, r=T/S, is r <
0.3, future detection may take place for r > 10^{-2}-10^{-3}. At present all
known string theory inflation models predict tensor modes well below the level
of detection. Therefore a possible experimental discovery of tensor modes may
present a challenge to string cosmology.
The strongest bound on r in string inflation follows from the observation
that in most of the models based on the KKLT construction, the value of the
Hubble constant H during inflation must be smaller than the gravitino mass. For
the gravitino mass in the usual range, m_{3/2} < O(1) TeV, this leads to an
extremely strong bound r < 10^{-24}. A discovery of tensor perturbations with r
> 10^{-3} would imply that the gravitinos in this class of models are
superheavy, m_{3/2} > 10^{13} GeV. This would have important implications for
particle phenomenology based on string theory.Comment: 13 pages, 2 figure
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
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