2,153 research outputs found
Strong obstruction of the Berends-Burgers-van Dam spin-3 vertex
In the eighties, Berends, Burgers and van Dam (BBvD) found a nonabelian cubic
vertex for self-interacting massless fields of spin three in flat spacetime.
However, they also found that this deformation is inconsistent at higher order
for any multiplet of spin-three fields. For arbitrary symmetric gauge fields,
we severely constrain the possible nonabelian deformations of the gauge algebra
and, using these results, prove that the BBvD obstruction cannot be cured by
any means, even by introducing fields of spin higher (or lower) than three.Comment: 19 pages, no figur
Development of Lumped Element Kinetic Inductance Detectors for NIKA
Lumped-element kinetic inductance detectors(LEKIDs) have recently shown
considerable promise as direct absorption mm-wavelength detectors for
astronomical applications. One major research thrust within the N\'eel Iram
Kids Array (NIKA) collaboration has been to investigate the suitability of
these detectors for deployment at the 30-meter IRAM telescope located on Pico
Veleta in Spain. Compared to microwave kinetic inductance detectors (MKID),
using quarter wavelength resonators, the resonant circuit of a LEKID consists
of a discrete inductance and capacitance coupled to a feedline. A high and
constant current density distribution in the inductive part of these resonators
makes them very sensitive. Due to only one metal layer on a silicon substrate,
the fabrication is relatively easy. In order to optimize the LEKIDs for this
application, we have recently probed a wide variety of individual resonator and
array parameters through simulation and physical testing. This included
determining the optimal feed-line coupling, pixel geometry, resonator
distribution within an array (in order to minimize pixel cross-talk), and
resonator frequency spacing. Based on these results, a 144-pixel Aluminum array
was fabricated and tested in a dilution fridge with optical access, yielding an
average optical NEP of ~2E-16 W/Hz^1/2 (best pixels showed NEP = 6E-17 W/Hz^1/2
under 4-8 pW loading per pixel). In October 2010 the second prototype of LEKIDs
has been tested at the IRAM 30 m telescope. A new LEKID geometry for 2
polarizations will be presented. Also first optical measurements of a titanium
nitride array will be discussed.Comment: 5 pages, 12 figures; ISSTT 2011 Worksho
Towards greener transportation infrastructure through innovative digital twins assessment : study case in Uzbekistan
Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2023.The aim of this paper is to evaluate the use of digital due diligence in infrastructure
projects through a real case study. As part of the Sustainable Development Goals,
innovative digital tools are being developed to provide an advanced impact assessment,
and virtual models such as digital twins are a promising technology for infrastructure
projects. These models can not only provide an accurate representation, but also be used
to run simulations, identify, and evaluate performance issues and generate possible
improvements, leading to a more resilient and sustainable design.
The selected case study, the upgrade of the 4R180 rural road section located in
Uzbekistan, was supported by the Asian Development Bank (ADB) in partnership with
ORIS, to pilot a multiple-scenario digital analysis of its pavement design. First, data
gathering was required to define the local context and the design solutions to be
evaluated. Then, through the ORIS platform, the project and design options were digitised.
The assessment of the results obtained from the ORIS platform showed that the pavement
performance over its lifespan can be significantly improved by making informed and datadriven decisions at an early stage of the project
Adoptive immunotherapy monitored by micro-MRI in experimental colorectal liver metastasis
In this study we used the colon carcinoma DHDK12 cell line and generated single metastasis after subcapsular injection in BDIX rats as an experimental tumor model. The aim of the work was to set up in vitro experimental conditions to prepare immune effector cells and in vivo conditions for monitoring the effects of such cells injected as adoptive immunotherapy. Dendritic cells can process tumor cell antigens, induce a T-cell response and be used ex vivo to prepare activated lymphocytes. Lymphocytes were harvested from mesenteric lymph nodes and cocultured with bone marrow-derived autologous dendritic cells previously loaded with irradiated tumor cells. In vitro, the coculture: 1) induced the proliferation of lymphocytes, 2) expanded a preferential subpopulation of T CD8 lymphocytes, and 3) was in favor of lymphocyte cytotoxic activity against the DHDK12 tumor cell line. Activated lymphocytes were injected in the tumor-bearing rat portal vein. Parameters could be set to monitor tumor volume by micro MRI. This monitoring before and after treatment and immunohistochemical examinations revealed that: 1) micro MRI is an appropriate tool to survey metastasis growth in rat, 2) injected lymphocytes increase lesional infiltration with T CD8 cells even 15 days after treatment, 3) a dose of 50 millions lymphocytes is not sufficient to act on the course of the tumor
Invasive Ductular Reaction Operates Hepatobiliary Junctions upon Hepatocellular Injury in Rodents and Humans.
Ductular reaction (DR) is observed in virtually all liver diseases in both humans and rodents. Depending on the injury, DR is confined within the periportal area or invades the parenchyma. On severe hepatocellular injury, invasive DR has been proposed to arise for supplying the liver with new hepatocytes. However, experimental data evidenced that DR contribution to hepatocyte repopulation is at the most modest, unless replicative capacity of hepatocytes is abrogated. Herein, we proposed that invasive DR could contribute to operating hepatobiliary junctions on hepatocellular injury. The choline-deficient ethionine-supplemented mouse model of hepatocellular injury and human liver samples were used to evaluate the hepatobiliary junctional role of the invasive form of DR. Choline-deficient ethionine-supplemented-induced DR expanded as biliary epithelium into the lobule and established new junctions with the canaliculi. By contrast, no new ductular-canalicular junctions were observed in mouse models of biliary obstructive injury exhibiting noninvasive DR. Similarly, in humans, an increased number of hepatobiliary junctions were observed in hepatocellular diseases (viral, drug induced, or metabolic) in which DR invaded the lobule but not in biliary diseases (obstruction or cholangitis) in which DR was contained within the portal mesenchyme. In conclusion, our data in rodents and humans support that invasive DR plays a hepatobiliary junctional role to maintain structural continuity between hepatocytes and ducts in disorders affecting hepatocytes
Modelling predictors of molecular response to frontline imatinib for patients with chronic myeloid leukaemia
BACKGROUND: Treatment of patients with chronic myeloid leukaemia (CML) has become increasingly difficult in recent years due to the variety of treatment options available and challenge deciding on the most appropriate treatment strategy for an individual patient. To facilitate the treatment strategy decision, disease assessment should involve molecular response to initial treatment for an individual patient. Patients predicted not to achieve major molecular response (MMR) at 24 months to frontline imatinib may be better treated with alternative frontline therapies, such as nilotinib or dasatinib. The aims of this study were to i) understand the clinical prediction 'rules' for predicting MMR at 24 months for CML patients treated with imatinib using clinical, molecular, and cell count observations (predictive factors collected at diagnosis and categorised based on available knowledge) and ii) develop a predictive model for CML treatment management. This predictive model was developed, based on CML patients undergoing imatinib therapy enrolled in the TIDEL II clinical trial with an experimentally identified achieving MMR group and non-achieving MMR group, by addressing the challenge as a machine learning problem. The recommended model was validated externally using an independent data set from King Faisal Specialist Hospital and Research Centre, Saudi Arabia. PRINCIPLE FINDINGS: The common prognostic scores yielded similar sensitivity performance in testing and validation datasets and are therefore good predictors of the positive group. The G-mean and F-score values in our models outperformed the common prognostic scores in testing and validation datasets and are therefore good predictors for both the positive and negative groups. Furthermore, a high PPV above 65% indicated that our models are appropriate for making decisions at diagnosis and pre-therapy. Study limitations include that prior knowledge may change based on varying expert opinions; hence, representing the category boundaries of each predictive factor could dramatically change performance of the models.Haneen Banjar, Damith Ranasinghe, Fred Brown, David Adelson, Trent Kroger, Tamara Leclercq, Deborah White, Timothy Hughes, Naeem Chaudhr
Consistent couplings between spin-2 and spin-3 massless fields
We solve the problem of constructing consistent first-order
cross-interactions between spin-2 and spin-3 massless fields in flat spacetime
of arbitrary dimension n > 3 and in such a way that the deformed gauge algebra
is non-Abelian. No assumptions are made on the number of derivatives involved
in the Lagrangian, except that it should be finite. Together with locality, we
also impose manifest Poincare invariance, parity invariance and analyticity of
the deformations in the coupling constants.Comment: LaTeX file. 29 pages, no figures. Minor corrections. Accepted for
publication in JHE
Weyl approach to representation theory of reflection equation algebra
The present paper deals with the representation theory of the reflection
equation algebra, connected with a Hecke type R-matrix. Up to some reasonable
additional conditions the R-matrix is arbitrary (not necessary originated from
quantum groups). We suggest a universal method of constructing finite
dimensional irreducible non-commutative representations in the framework of the
Weyl approach well known in the representation theory of classical Lie groups
and algebras. With this method a series of irreducible modules is constructed
which are parametrized by Young diagrams. The spectrum of central elements
s(k)=Tr_q(L^k) is calculated in the single-row and single-column
representations. A rule for the decomposition of the tensor product of modules
into the direct sum of irreducible components is also suggested.Comment: LaTeX2e file, 27 pages, no figure
Identification of Pro-MMP-7 as a Serum Marker for Renal Cell Carcinoma by Use of Proteomic Analysis
International audienceBACKGROUND: No validated renal cell carcinoma (RCC) marker is known for detection of asymptomatic disease in selected populations or for prognostic purposes or treatment monitoring. We identified immunogenic proteins as tumor markers for RCC by combining conventional proteome analysis with serological screening, and we investigated the diagnostic clinical value of such markers in serum. METHODS: We studied the immunogenic protein expression profile of CAL 54, a human RCC cell line, by 2-dimensional electrophoresis combined with immunoblotting using sera from healthy donors compared with RCC patients. We developed a homogeneous, fluorescent, dual-monoclonal immunoassay for metalloproteinase 7 (MMP-7) and used it to measure MMP-7 in sera from 30 healthy donors, 30 RCC patients, and 40 control patients. RESULTS: Pro-MMP-7 (29 kDa; pI 7.7) in the CAL 54 cell line secretome was an immunogenic protein reactive with RCC patient sera but not with control sera. The concentrations of pro-MMP-7 were increased (P <0.0001) in sera of RCC patients (median 7.56 microg/L; range 3.12-30.5 microg/L) compared with healthy controls (median 2.13 microg/L; range 0.17-3.5 microg/L). Serum pro-MMP-7 had a sensitivity of 93% (95% CI 78%-99%) at a specificity of 75% (59%-87%) for RCC in the samples tested. CONCLUSION: Proteomics technology combined with serology led to the identification of serum pro-MMP-7 as a marker of RCC and represents a powerful tool in searching for candidate proteins as biomarkers
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