3,818 research outputs found
Comment on: Reply to comment on `Perfect imaging without negative refraction'
Whether or not perfect imaging is obtained in the mirrored version of
Maxwell's fisheye lens is debated in the comment/reply sequence
[Blaikie-2010njp, Leonhardt-2010njp] discussing Leonhardt's original paper
[Leonhardt-2009njp]. Here we show that causal solutions can be obtained without
the need for an "active localized drain", contrary to the claims in
[Leonhardt-2010njp].Comment: v2 (added MEEP ctl file), v3 (publisher statement
Sistema coletor de frutos de macaúba.
Este trabalho teve como objetivo avaliar a qualidade do óleo na polpa de frutos de macaúba em função do tempo de permanência de frutos no campo mantido em sistema de coletores/contentores
Características químicas e bioquímicas de frutos de macaúbas: maturação uniforme no cacho.
Para contribuir com conhecimento sobre a maturação de frutos de macauba, neste trabalho foram investigados aspectos de composição e atividade enzimática em frutos de macaúba dispostos nas porções apical, mediana e distal do cacho
Four Poynting Theorems
The Poynting vector is an invaluable tool for analysing electromagnetic
problems. However, even a rigorous stress-energy tensor approach can still
leave us with the question: is it best defined as \Vec{E} \cross \Vec{H} or
as \Vec{D} \cross \Vec{B}? Typical electromagnetic treatments provide yet
another perspective: they regard \Vec{E} \cross \Vec{B} as the appropriate
definition, because \Vec{E} and \Vec{B} are taken to be the fundamental
electromagnetic fields. The astute reader will even notice the fourth possible
combination of fields: i.e. \Vec{D} \cross \Vec{H}. Faced with this diverse
selection, we have decided to treat each possible flux vector on its merits,
deriving its associated energy continuity equation but applying minimal
restrictions to the allowed host media. We then discuss each form, and how it
represents the response of the medium. Finally, we derive a propagation
equation for each flux vector using a directional fields approach; a useful
result which enables further interpretation of each flux and its interaction
with the medium.Comment: 8 pages. Updated slightly from EJP versio
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TRAIL-induced variation of cell signaling states provides nonheritable resistance to apoptosis.
TNFα-related apoptosis-inducing ligand (TRAIL), specifically initiates programmed cell death, but often fails to eradicate all cells, making it an ineffective therapy for cancer. This fractional killing is linked to cellular variation that bulk assays cannot capture. Here, we quantify the diversity in cellular signaling responses to TRAIL, linking it to apoptotic frequency across numerous cell systems with single-cell mass cytometry (CyTOF). Although all cells respond to TRAIL, a variable fraction persists without apoptotic progression. This cell-specific behavior is nonheritable where both the TRAIL-induced signaling responses and frequency of apoptotic resistance remain unaffected by prior exposure. The diversity of signaling states upon exposure is correlated to TRAIL resistance. Concomitantly, constricting the variation in signaling response with kinase inhibitors proportionally decreases TRAIL resistance. Simultaneously, TRAIL-induced de novo translation in resistant cells, when blocked by cycloheximide, abrogated all TRAIL resistance. This work highlights how cell signaling diversity, and subsequent translation response, relates to nonheritable fractional escape from TRAIL-induced apoptosis. This refined view of TRAIL resistance provides new avenues to study death ligands in general
Modulation of small leucine-rich proteoglycans (SLRPs) expression in the mouse uterus by estradiol and progesterone
<p>Abstract</p> <p>Background</p> <p>We have previously demonstrated that four members of the family of small leucine-rich-proteoglycans (SLRPs) of the extracellular matrix (ECM), named decorin, biglycan, lumican and fibromodulin, are deeply remodeled in mouse uterine tissues along the estrous cycle and early pregnancy. It is known that the combined action of estrogen (E2) and progesterone (P4) orchestrates the estrous cycle and prepares the endometrium for pregnancy, modulating synthesis, deposition and degradation of various molecules. Indeed, we showed that versican, another proteoglycan of the ECM, is under hormonal control in the uterine tissues.</p> <p>Methods</p> <p>E2 and/or medroxiprogesterone acetate (MPA) were used to demonstrate, by real time PCR and immunoperoxidase staining, respectively, their effects on mRNA expression and protein deposition of these SLRPs, in the uterine tissues.</p> <p>Results</p> <p>Decorin and lumican were constitutively expressed and deposited in the ECM in the absence of the ovarian hormones, whereas deposition of biglycan and fibromodulin were abolished from the uterine ECM in the non-treated group. Interestingly, ovariectomy promoted an increase in decorin, lumican and fibromodulin mRNA levels, while biglycan mRNA conspicuously decreased. Hormone replacement with E2 and/or MPA differentially modulates their expression and deposition.</p> <p>Conclusions</p> <p>The patterns of expression of these SLRPs in the uterine tissues were found to be hormone-dependent and uterine compartment-related. These results reinforce the existence of subpopulations of endometrial fibroblasts, localized into distinct functional uterine compartments, resembling the organization into basal and functional layers of the human endometrium.</p
Uniformidade de maturação dos frutos no cacho de macaúbas nativas do pantanal e cerrado.
o presente trabalho teve como objetivo avaliar a uniformidade de maturação dos frutos no cacho em macaúbas de ocorrência natural nos biomas Pantanal e Cerrado
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