1,027 research outputs found
Evaluation of transforming growth factor and vascular endothelial growth factor polymorphisms in Taiwan Chinese patients with pterygium
[[abstract]]PURPOSE. Pterygium is an invasive and highly vascularized growth, thought to arise from activated and proliferating limbal epithelial stem cells. Epidemiologic studies have found the increase of active angiogenic and epithelial growth factors in pterygia, and implicated that these molecules could be involved directly or indirectly in the pathogenesis of pterygia as causative factors. The aim of this study was to investigate the association of polymorphisms of transforming growth factor (TGF) and vascular endothelial growth factor (VEGF) with pterygium.
METHODS. A total of 133 pterygium patients and 105 volunteers without pterygium were enrolled in this study. Polymerase chain reaction based restriction fragment length polymorphism analysis was used to resolve the TGF-beta 1-509 and VEGF-460 genotypes.
RESULTS. There was no significant difference in the allele frequency or genotype of TGF-beta 1-509 or VEGF-460 between total pterygium and the control group. No interaction between TGF-beta 1-509 and VEGF-460 was found either.
CONCLUSIONS. These results indicate that TGF-beta 1-509 and VEGF-460 polymorphisms were not highly associated with the pathology of pterygium. However, it may still be worthwhile to continue to search for angiogenic gene polymorphisms in order to predict the development of pterygium
The Taiwan ECDFS Near-Infrared Survey: Ultra-deep J and Ks Imaging in the Extended Chandra Deep Field-South
We present ultra-deep J and Ks imaging observations covering a 30' * 30' area
of the Extended Chandra Deep Field-South (ECDFS) carried out by our Taiwan
ECDFS Near-Infrared Survey (TENIS). The median 5-sigma limiting magnitudes for
all detected objects in the ECDFS reach 24.5 and 23.9 mag (AB) for J and Ks,
respectively. In the inner 400 arcmin^2 region where the sensitivity is more
uniform, objects as faint as 25.6 and 25.0 mag are detected at 5-sigma. So this
is by far the deepest J and Ks datasets available for the ECDFS. To combine the
TENIS with the Spitzer IRAC data for obtaining better spectral energy
distributions of high-redshift objects, we developed a novel deconvolution
technique (IRACLEAN) to accurately estimate the IRAC fluxes. IRACLEAN can
minimize the effect of blending in the IRAC images caused by the large
point-spread functions and reduce the confusion noise. We applied IRACLEAN to
the images from the Spitzer IRAC/MUSYC Public Legacy in the ECDFS survey
(SIMPLE) and generated a J+Ks selected multi-wavelength catalog including the
photometry of both the TENIS near-infrared and the SIMPLE IRAC data. We
publicly release the data products derived from this work, including the J and
Ks images and the J+Ks selected multiwavelength catalog.Comment: 25 pages, 25 figures, ApJS in pres
Optimizing passive acoustic sampling of bats in forests
Passive acoustic methods are increasingly used in biodiversity research and monitoring programs because they are cost-effective and permit the collection of large datasets. However, the accuracy of the results depends on the bioacoustic characteristics of the focal taxa and their habitat use. In particular, this applies to bats which exhibit distinct activity patterns in three-dimensionally structured habitats such as forests. We assessed the performance of 21 acoustic sampling schemes with three temporal sampling patterns and seven sampling designs. Acoustic sampling was performed in 32 forest plots, each containing three microhabitats: forest ground, canopy, and forest gap. We compared bat activity, species richness, and sampling effort using species accumulation curves fitted with the clench equation. In addition, we estimated the sampling costs to undertake the best sampling schemes. We recorded a total of 145,433 echolocation call sequences of 16 bat species. Our results indicated that to generate the best outcome, it was necessary to sample all three microhabitats of a given forest location simultaneously throughout the entire night. Sampling only the forest gaps and the forest ground simultaneously was the second best choice and proved to be a viable alternative when the number of available detectors is limited. When assessing bat species richness at the 1-km(2) scale, the implementation of these sampling schemes at three to four forest locations yielded highest labor cost-benefit ratios but increasing equipment costs. Our study illustrates that multiple passive acoustic sampling schemes require testing based on the target taxa and habitat complexity and should be performed with reference to cost-benefit ratios. Choosing a standardized and replicated sampling scheme is particularly important to optimize the level of precision in inventories, especially when rare or elusive species are expected
Pengembangan Metode Bangkitan Dan Tarikan Perjalanan Berdasarkan Citra Quickbird
As a basic model, trip generation model aims to obtain the number of movement generated by each origin and the one attracted to each destination zone. Based on the movement, trip generation model is categorized into home-based trip generation and non home-originated/destinated trip attraction. Given that the different types of activities attract trips with different characteristics, it can be concluded that land use management determines the movement and activities. Remote sensing imagery has been extensively used in various research themes including land use management or land use and detailed land utility. As one of the remote sensing imageries, Quickbird imagery is advantageous with its high spatial resolution which is 0.61 cm. Therefore, it is interesting to apply the 0.61 cm spatial resolution to the trip generation model to estimate the number of trips at the trip generation. This aims is to minimize field activities which are high cost, extensive workers, and relatively time consuming
Smooth analysis of the condition number and the least singular value
Let \a be a complex random variable with mean zero and bounded variance.
Let be the random matrix of size whose entries are iid copies of
\a and be a fixed matrix of the same size. The goal of this paper is to
give a general estimate for the condition number and least singular value of
the matrix , generalizing an earlier result of Spielman and Teng for
the case when \a is gaussian.
Our investigation reveals an interesting fact that the "core" matrix does
play a role on tail bounds for the least singular value of . This
does not occur in Spielman-Teng studies when \a is gaussian.
Consequently, our general estimate involves the norm .
In the special case when is relatively small, this estimate is nearly
optimal and extends or refines existing results.Comment: 20 pages. An erratum to the published version has been adde
Oxygenated conditions in the aftermath of the Lomagundi-Jatuli Event : the carbon isotope and rare earth element signatures of the Paleoproterozoic Zaonega Formation, Russia
This study was supported by Estonian Research Council project PRG447, and the Estonian Centre of Analytical Chemistry. K.P. and A.L. were supported by the Research Council of Norway through its Centres of Excellence funding scheme grant No. 223259. K.P. acknowledges the Estonian Research Council grant MOBJD542 and T.M. PUT611.The c. 2.0 Ga Zaonega Formation of the Onega Basin (NW Russia) has been central in efforts to understand what led to the initial rise (Great Oxidation Event, GOE) and postulated fall in free atmospheric oxygen and associated high-amplitude carbon cycle excursions, the Lomagundi-Jatuli Event (LJE) and subsequent Shunga Event during Paleoproterozoic time. The Formation accumulated shortly after the LJE and encompasses both the recovery in the carbon cycle and hypothesised contraction of the oceanic oxidant pool. However, interpreting the correct environmental context recorded by geochemical signatures in the Zaonega rocks is difficult due to a complex depositional and diagenetic history. In order to robustly constrain that history, we undertook a multiproxy study (mineralogy, petrography, carbon isotope and rare earth element composition) of carbonate beds in the upper part of the Zaonega Formation recovered in the 102-m composite section of the OnZap drill-cores. Our findings differentiate primary environmental signatures from secondary overprinting and show that: (i) the best-preserved carbonate beds define an upwards increasing δ13Ccarb trend from c. -5.4‰ to near 0‰; and that (ii) large intra-bed δ13Ccarb variations reflect varying contributions of methanotrophic dissolved inorganic carbon (DIC) to the basinal DIC pool. Rare earth element and yttrium (REYSN) patterns confirm a marine origin of the carbonate beds whereas a consistent positive EuSN anomaly suggests a strong high temperature hydrothermal input during accumulation of the Zaonega Formation. Importantly, the presence of a negative CeSN anomaly in the REYSN pattern indicates an oxygenated atmosphere-ocean system shortly after the LJE and indicates that models invoking a fall in oxygen at that time require reassessment.PostprintPeer reviewe
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