1,297 research outputs found
Order statistics from overlapping samples: bivariate densities and regression properties
In this paper we are interested in the joint distribution of two order statistics from overlapping samples. We give an explicit formula for the distribution of such a pair of random variables under the assumption that the parent distribution is absolutely continuous (with respect to the Lebesgue measure on the real line). The distribution is identified through the form of the density with respect to a measure which is a sum of the bivariate Lebesgue measure on R2 and the univariate Lebesgue measure on the diagonal {(x, x) : x â R}. We are also interested in the question to what extent conditional expectation of one of such order statistic given another determines the parent distribution. In particular, we provide a new characterization by linearity of regression of an order statistic from the extended sample given the one from the original sample, special case of which solves a problem explicitly stated in the literature. It appears that to describe the correct parent distribution it is convenient to use quantile density functions. In several other cases of regressions of order statistics we provide new results regarding uniqueness of the distribution in the sample. Nevertheless the general question of identifiability of the parent distribution
by regression of order statistics from overlapping samples remains open.Ministry of Science and Technology, TaiwanMinisterio de Economia, Industria y Competitividad (MINECO). EspañaNational Science Center, Polan
Mobile Metaverse: A Road Map from Metaverse to Metavehicles
With the rapid development of communication technologies and extended reality
(XR), the services and applications of the Metaverse are gradually entering our
lives. However, the current development of the Metaverse provides users with
services that are homogeneous with the user experience that the Internet has
brought in the past, making them more like an extension of the Internet. In
addition, as a mobile application carrier for the Metaverse, it is also worth
considering how vehicles with diverse onboard components can develop in synergy
with the Metaverse. In this article, we focus on the core of the Metaverse,
namely user experience, and provide a road map from Metaverse to Metaverse
vehicles (Metavehicles). Specifically, we first elaborate on six features of
the Metaverse from the perspective of user experience and propose a
hierarchical framework for the Metaverse based on the evolutionary logic of the
features. Under the guidance of this framework, we discuss the empowerment of
onboard components of Metavehicles on the development of the Metaverse, and
analyze the service experience that Metavehicles can bring to two types of
users, namely drivers and passengers. Finally, considering the differentiated
development levels of Metaverse and autonomous driving, we further establish a
hierarchical framework for Metavehicles from three aspects (i.e., enhance
Metaverse, enhance driving experience, and enhance entertainment experience),
providing an evolutionary path for the development of Metavehicles.Comment: 7 pages, 5 figure
A rare, highly aggressive primitive neuroectodermal tumor of the kidney: Case report and literature review
AbstractWe report a case of a 14-year-old boy who initially suffered from a sudden onset of abdominal pain for 2Â weeks with a protrusive soft mass over the left upper abdomen. No obvious symptomatic symptoms or body weight loss were observed. However, early lung metastasis was detected after an initial computed tomographic examination. Even after we performed salvage en bloc resection of the huge retroperitoneal tumor after primary neoadjuvant chemotherapy, the final outcome was still poor. A diagnosis according to radiologic findings was uncharacteristic. Finally, a pathologic diagnosis based on histologic and immunohistochemical results revealed a rare renal peripheral primitive neuroectodermal tumor
Comparison of the mismatch-specific endonuclease method and denaturing high-performance liquid chromatography for the identification of HBB gene mutations
<p>Abstract</p> <p>Background</p> <p>Beta-thalassemia is a common autosomal recessive hereditary disease in the Meditertanean, Asia and African areas. Over 600 mutations have been described in the beta-globin (<it>HBB</it>), of which more than 200 are associated with a beta-thalassemia phenotype.</p> <p>Results</p> <p>We used two highly-specific mutation screening methods, mismatch-specific endonuclease and denaturing high-performance liquid chromatography, to identify mutations in the <it>HBB </it>gene. The sensitivity and specificity of these two methods were compared. We successfully distinguished mutations in the <it>HBB </it>gene by the mismatch-specific endonuclease method without need for further assay. This technique had 100% sensitivity and specificity for the study sample.</p> <p>Conclusion</p> <p>Compared to the DHPLC approach, the mismatch-specific endonuclease method allows mutational screening of a large number of samples because of its speed, sensitivity and adaptability to semi-automated systems. These findings demonstrate the feasibility of using the mismatch-specific endonuclease method as a tool for mutation screening.</p
Second-trimester Maternal Serum Quadruple Test for Down Syndrome Screening: A Taiwanese Population-based Study
SummaryObjectiveTo assess the usefulness of quadruple test screening for Down syndrome in Taiwan.Materials and MethodsMaternal serum concentrations of a-fetoprotein, human chorionic gonadotropin, unconjugated estriol, and inhibin A were measured in 21,481 pregnant women from 15 to 20 weeks of gestation.ResultsOf the 21,481 women, 977 returned values greater than the high-risk cut-off value (1 in 270). Most of these women (86.2%) decided to have an invasive procedure for genetic diagnosis. Nine cases of Down syndrome and 19 cases of other chromosomal anomalies were detected prenatally. Two children with Down syndrome were diagnosed after delivery even though a low estimated risk was determined following the quadruple test. The detection rate was 81.8% (nine out of 11 cases), with a 4.4% false-positive rate. The median multiple of the median value for a-fetoprotein, human chorionic gonadotropin, unconjugated estriol and inhibin A were 0.87, 2.34, 0.77 and 2.16, respectively, in affected cases.ConclusionThis is the first study of the quadruple test for Down syndrome in a Chinese population. Our findings suggested that the second-trimester quadruple test provides an effective screening tool for Down syndrome in Taiwan
NanodiamondâAssisted High Performance Lithium and Sodium Ions CoâStorage
While lithium resources are scarce for high energyâdense lithiumâion batteries (LIBs), sodiumâion batteries (SIBs), serving as an alternative, inherently suffer from low capacity and the highâcost use of nonâgraphite anodes. Combining Liâ and Naâions within a single battery system is expected to mitigate the shortcomings of both systems while leveraging their respective advantages. In this study, we developed and assembled a nanodiamonds (NDs)âassisted coâLi/Naâion battery (NDâLSIB). This innovative battery system comprised a commercial graphite anode, an NDâmodified polypropylene (DPP) separator, a hybrid lithium/sodiumâbased electrolyte, and a cathode. It is theoretically and experimentally demonstrated that the ND/Li coâinsertion can serve as an ionâdrill opening graphite layers and reconstructing graphite anodes into fewâlayered graphene with expanding interlayer space, achieving highly efficient Li/Na storage and the theoretical maximum of LiC6 for Li storage in graphite. In addition, ND is helpful for creating a LiFâ/NaFârich hybrid solid electrolyte interface with improved ionic mobility, mechanical strength, and reversibility. Consequently, NDâLSIBs have higher specific capacities ~1.4 times the theoretical value of LIBs and show longâterm cycling stability. This study proposes and realizes the concept of Li/Na coâstorage in one ion battery with compatible highâperformance, costâeffectiveness, and industrial prospects
CARS and SHG microscopy to follow the collagen production in living human corneal fibroblasts and mesenchymal stem cells in fibrin gel 3D cultures
Coherent anti-Stokes Raman scattering (CARS) microscopy is combined with
second harmonic generation (SHG) technique in order to follow the early stage
of stem cell differentiation within a 3D scaffold. CARS microscopy can detect
lipid membranes and droplet compartments in living cells and SHG microscopy
enables a strong imaging contrast for molecules with a non-centrosymmetric
ordered structure like collagen. One of the first evidence of hMSCs
differentiation is the formation of an extracellular matrix (ECM) where the
collagen protein is its main component. This work demonstrated the multimodal
CARS and SHG microscopy as a powerful non-invasive label free technique to
investigate the collagen production dynamic in living cell 3D cultures. Its
ability to image the cell morphology and the produced collagen distribution on
a long term (4 weeks) experiment allowed to obtain important information about
the cell-scaffold interaction and the ECM production. The very low limit
reached in detecting collagen has permitted to map even the small amount of
collagen produced by the cells in few hours of culture. This demonstrates
multimodal CARS and SHG microscopy as a novel method to follow cells collagen
production and cells differentiation process. In addition the experiment shows
that the technique is a powerful tool for imaging of very thick sections (about
4 mm). The study conducted on mesenchymal stem cell in fibrin gel cultures
confirmed that differentiation stimulus is induced by the scaffold. The
monitoring of stem cell differentiation within a scaffold in a non-destructive
way will be an important advantage in regenerative medicine and tissue
engineering field.Comment: 15 pages, 5 figures, ECONOS 201
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