315 research outputs found
The General Type N Solution of New Massive Gravity
We find the most general algebraic type N solution with non-vanishing scalar
curvature, which comprises all type N solutions of new massive gravity in three
dimensions. We also give the special forms of this solution, which correspond
to certain critical values of the topological mass. Finally, we show that at
the special limit, the null Killing isometry of the spacetime is restored and
the solution describes AdS pp-waves.Comment: 7 pages, twocolumn REVTeX; minor changes, new references adde
A Complete Classification of Higher Derivative Gravity in 3D and Criticality in 4D
We study the condition that the theory is unitary and stable in
three-dimensional gravity with most general quadratic curvature,
Lorentz-Chern-Simons and cosmological terms. We provide the complete
classification of the unitary theories around flat Minkowski and (anti-)de
Sitter spacetimes. The analysis is performed by examining the quadratic
fluctuations around these classical vacua. We also discuss how to understand
critical condition for four-dimensional theories at the Lagrangian level.Comment: 20 pages, v2: minor corrections, refs. added, v3: logic modified, v4:
typos correcte
Quadratic Curvature Gravity with Second Order Trace and Massive Gravity Models in Three Dimensions
The quadratic curvature lagrangians having metric field equations with second
order trace are constructed relative to an orthonormal coframe. In
dimensions, pure quadratic curvature lagrangian having second order trace
constructed contains three free parameters in the most general case. The fourth
order field equations of some of these models, in arbitrary dimensions, are
cast in a particular form using the Schouten tensor. As a consequence, the
field equations for the New massive gravity theory are related to those of the
Topologically massive gravity. In particular, the conditions under which the
latter is "square root" of the former are presented.Comment: 24 pages, to appear in GR
T-cell subpopulations αÎČ and γΎ in cord blood of very preterm infants : The influence of intrauterine infection
Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPreterm infants are very susceptible to infections. Immune response mechanisms in this group of patients and factors that influence cord blood mononuclear cell populations remain poorly understood and are considered insufficient. However, competent immune functions of the cord blood mononuclear cells are also described. The aim of this work was to evaluate the T-cell population (CD3+) with its subpopulations bearing T-cell receptor (TCR) αÎČ or TCR γΎ in the cord blood of preterm infants born before 32 weeks of gestation by mothers with or without an intrauterine infection. Being a pilot study, it also aimed at feasibility check and assessment of an expected effect size. The cord blood samples of 46 infants age were subjected to direct immunofluorescent staining with monoclonal antibodies and then analyzed by flow cytometry. The percentage of CD3+ cells in neonates born by mothers with diagnosis of intrauterine infection was significantly lower than in neonates born by mothers without infection (p = 0.005; Mann-Whitney U test). The number of cells did not differ between groups. Infection present in the mother did not have an influence on the TCR αÎČ or TCR γΎ subpopulations. Our study contributes to a better understanding of preterm infants' immune mechanisms, and sets the stage for further investigations.Peer reviewedFinal Published versio
Recurrent spontaneous hip dislocation in a patient with neurofibromatosis type 1: a case report
<p>Abstract</p> <p>Introduction</p> <p>Neurofibromatosis type-1 is a common genetic disorder which often affects the skeleton. Skeletal manifestations of neurofibromatosis type-1 include scoliosis, congenital pseudarthrosis of the tibia and intraosseous cystic lesions. Dislocation of the hip associated with neurofibromatosis type-1 is a rare occurrence and is underreported in the literature.</p> <p>Case presentation</p> <p>We report a case of hip dislocation resulting from an intra-articular neurofibroma in an 18-year-old Caucasian woman following minor trauma. This was originally suggested by the abnormalities on early radiographs of her pelvis and later confirmed with computed tomography and magnetic resonance imaging. Treatment was successful with skeletal traction for six weeks with no further hip dislocations at a 12-year follow-up.</p> <p>Conclusion</p> <p>This case illustrates the radiological features of this rare complication of neurofibromatosis type-1 using the modalities of plain radiograph, magnetic resonance imaging and computed tomography reconstruction. The radiological images give a clear insight into the mechanism by which neurofibromatosis type-1 leads to hip dislocation. It also demonstrates one treatment option with excellent results on long-term follow-up.</p
PodridĂ”es em raĂzes de mandioca: problemas e soluçÔes para o seu controle.
O objetivo deste trabalho foi apresentar de modo simples e objetivo medidas para superação dos principais fatores relacionados com a ocorrĂȘncia das podridĂ”es das raĂzes da mandioca.bitstream/item/214557/1/DOC455.pd
Finding needles in haystacks: linking scientific names, reference specimens and molecular data for Fungi
DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi
Efeito de extratos vegetais na inibição do crescimento micelial de Lasiodiplodia pseudotheobromae e Cylindrocladium sp.
O presente trabalho teve o objetivo de avaliar o efeito de extratos de plantas alimentĂcias nĂŁo convencionais (PANCs) e de plantas medicinais no crescimento de Lasiodiplodiapseudotheobromae e Cylindrocladium sp. Foram avaliados sete extratos de PANCs e nove extratos de plantas medicinais. Os extratos foram incorporados ao meio de cultura na concentração de 1%. Um disco de micĂ©lio fĂșngico foi depositado no centro de cada placa. A avaliação foi realizada diariamente atĂ© que o crescimento micelial atingisse uma das extremidades da placa em um dos tratamentos. O delineamento experimental foi inteiramente casualizado com cinco repetiçÔes. Para L. pseudotheobromae, os extratos de flor de jambu, gengibre, eucalipto, folha de jambu, batata-doce, erva-cidreira, vinagreira, mastruz e alfavaca proporcionaram reduçÔes entre 8,33% e 38,55%. Para Cylindrocladium sp., os extratos de flor de jambu, alfavaca, noni, nim, erva- -cidreira, cipĂł-d?alho, gengibre, coramina, capim-santo, mastruz, batata-doce, folha de jambu, ora-pro-nobis e vinagreira reduziram o crescimento micelial entre 7,48% e 18,04%. O extrato de flor de jambu apresentou os melhores resultados do estudo para ambos os fungos, representando assim, uma alternativa potencial a ser estudada no controle de doenças associadas a estes patĂłgenos.bitstream/item/220566/1/BPD145.pd
Directing cell therapy to anatomic target sites in vivo with magnetic resonance targeting
Cell-based therapy exploits modified human cells to treat diseases but its targeted application
in specific tissues, particularly those lying deep in the body where direct injection is not
possible, has been problematic. Here we use a magnetic resonance imaging (MRI) system to
direct macrophages carrying an oncolytic virus, Seprehvir, into primary and metastatic tumour
sites in mice. To achieve this, we magnetically label macrophages with super-paramagnetic
iron oxide nanoparticles and apply pulsed magnetic field gradients in the direction of the
tumour sites. Magnetic resonance targeting guides macrophages from the bloodstream into
tumours, resulting in increased tumour macrophage infiltration and reduction in tumour
burden and metastasis. Our study indicates that clinical MRI scanners can not only track the
location of magnetically labelled cells but also have the potential to steer them into one or
more target tissues
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