Postoperative fluid collection after hybrid debranching and endovascular repair of thoracoabdominal aortic aneurysms

ObjectiveHybrid thoracic endovascular aneurysm repair (H-TEVAR) to include visceral and renal debranching has emerged as a potential therapeutic option for thoracoabdominal aneurysms (TAAA). This study was performed to characterize the frequently noted development of postoperative fluid collections surrounding the bypass grafts.MethodsAll patients undergoing H-TEVAR from 2000-2010 (n = 39, 43.6% male) were identified. One hundred thirty-two bypasses were constructed (median 4 per patient) using either polyester (30), thin-walled polytetrafluoroethylene (ePTFE, 100) or saphenous vein (2). Follow-up computed tomography (CT) imaging was routinely performed at 1 and 6 months, and annually thereafter.ResultsOf the 37 patients with one follow-up CT, 20 (54.1%) were found to have fluid collections. The natural history of the 17 patients with collections and further follow-up imaging was variable, with 2 resolving, 6 stable, and 9 enlarging. Two patients with collections developed evidence of graft infection requiring reoperation. Two patients with enlarging sterile collections required evacuation for symptoms. By multivariate analysis, both preoperative creatinine (P = .005) and number of bypasses constructed (P = .04) independently correlated with the development of a fluid collection.ConclusionsPostoperative fluid collections following hybrid debranching procedures identified in this series represent a unique complication not previously described. The subsequent clinical course of these fluid collections is variable and ranges from benign to frank graft infection and relate both to patient factors, as well as specific operative strategies. Longer-term studies with more robust numbers of patient numbers are warranted to determine whether this complication may limit the long-term durability of this procedure

Obesity-Induced Colorectal Cancer Is Driven by Caloric Silencing of the Guanylin-GUCY2C Paracrine Signaling Axis.

Obesity is a well-known risk factor for colorectal cancer but precisely how it influences risks of malignancy remains unclear. During colon cancer development in humans or animals, attenuation of the colonic cell surface receptor guanylyl cyclase C (GUCY2C) that occurs due to loss of its paracrine hormone ligand guanylin contributes universally to malignant progression. In this study, we explored a link between obesity and GUCY2C silencing in colorectal cancer. Using genetically engineered mice on different diets, we found that diet-induced obesity caused a loss of guanylin expression in the colon with subsequent GUCY2C silencing, epithelial dysfunction, and tumorigenesis. Mechanistic investigations revealed that obesity reversibly silenced guanylin expression through calorie-dependent induction of endoplasmic reticulum stress and the unfolded protein response in intestinal epithelial cells. In transgenic mice, enforcing specific expression of guanylin in intestinal epithelial cells restored GUCY2C signaling, eliminating intestinal tumors associated with a high calorie diet. Our findings show how caloric suppression of the guanylin-GUCY2C signaling axis links obesity to negation of a universal tumor suppressor pathway in colorectal cancer, suggesting an opportunity to prevent colorectal cancer in obese patients through hormone replacement with the FDA-approved oral GUCY2C ligand linaclotide

Sustainable Drag Reduction in Turbulent Taylor-Couette Flows by Depositing Sprayable Superhydrophobic Surfaces

We demonstrate a reduction in the measured inner wall shear stress in moderately turbulent Taylor-Couette flows by depositing sprayable superhydrophobic microstructures on the inner rotor surface. The magnitude of reduction becomes progressively larger as the Reynolds number increases up to a value of 22% at Re=8.0×10[superscript 4]. We show that the mean skin friction coefficient C[subscript f] in the presence of the superhydrophobic coating can be fitted to a modified Prandtl–von Karman–type relationship of the form (C[subscript f]/2)[[superscript -1/2] = Mln (Re(C[subscript f]/2)[[superscript 1/2]) + N + (b/Δr)Re(C[subscript f]/2)[superscript 1/2] from which we extract an effective slip length of b ≈ 19  μm. The dimensionless effective slip length b[superscript +] = b/δ[subscript ν], where δ[subscript ν] is the viscous length scale, is the key parameter that governs the drag reduction and is shown to scale as b[[superscript +] ~ Re[superscript 1/2] in the limit of high Re.United States. Office of Naval Research (Contract 3002453814

BCL-2 family genetic profiling reveals microenvironment-specific determinants of chemotherapeutic response

The Bcl-2 family encompasses a diverse set of apoptotic regulators that are dynamically activated in response to various cell-intrinsic and -extrinsic stimuli. An extensive variety of cell culture experiments have identified effects of growth factors, cytokines, and drugs on Bcl-2 family functions, but in vivo studies have tended to focus on the role of one or two particular members in development and organ homeostasis. Thus, the ability of physiologically relevant contexts to modulate canonical dependencies that are likely to be more complex has yet to be investigated systematically. In this study, we report findings derived from a pool-based shRNA assay that systematically and comprehensively interrogated the functional dependence of leukemia and lymphoma cells upon various Bcl-2 family members across many diverse in vitro and in vivo settings. This approach permitted us to report the first in vivo loss of function screen for modifiers of the response to a front-line chemotherapeutic agent. Notably, our results reveal an unexpected role for the extrinsic death pathway as a tissue-specific modifier of therapeutic response. In particular, our findings show that particular tissue sites of tumor dissemination play critical roles in demarcating the nature and extent of cancer cell vulnerabilities and mechanisms of chemoresistance. Cancer Res; 71(17); 5850–8. ©2011 AACR.National Institutes of Health (U.S.) (NIH RO1 CA128803)National Cancer Institute (U.S.) (Integrated Cancer Biology Program grant NCI 1-U54-CA112967)David H. Koch Institute for Integrative Cancer Research at MIT (Ludwig Fellowship)Massachusetts Institute of Technology. Dept. of Biology (training grant

Towards a theta correspondence in families for type II dual pairs

Let $R$ be a commutative $\mathbb{Z}[1/p]$-algebra, let $m \leq n$ be positive integers, and let $G_n=\text{GL}_n(F)$ and $G_m=\text{GL}_m(F)$ where $F$ is a $p$-adic field. The Weil representation is the smooth $R[G_n\times G_m]$-module $C_c^{\infty}(\text{Mat}_{n\times m}(F),R)$ with the action induced by matrix multiplication. When $R=\mathbb{C}$ or is any algebraically closed field of banal characteristic compared to $G_n$ and $G_m$, the local theta correspondence holds by the work of Howe and M\'inguez. At the level of supercuspidal support, we interpret the theta correspondence as a morphism of varieties $\theta_R$, which we describe as an explicit closed immersion. For arbitrary $R$, we construct a canonical ring homomorphism $\theta^\#_{R} : \mathfrak{Z}_{R}(G_n)\to \mathfrak{Z}_{R}(G_m)$ that controls the action of the center $\mathfrak{Z}_{R}(G_n)$ of the category of smooth $R[G_n]$-modules on the Weil representation. We use the rank filtration of the Weil representation to first obtain $\theta_{\mathbb{Z}[1/p]}^\#$, then obtain $\theta^\#_R$ for arbitrary $R$ by proving $\mathfrak{Z}_R(G_n)$ is compatible with scalar extension. In particular, the map $\text{Spec}(\mathfrak{Z}_R(G_m))\to \text{Spec}(\mathfrak{Z}_R(G_n))$ induced by $\theta_R^\#$ recovers $\theta_R$ in the $R=\mathbb{C}$ case and in the banal case. We use gamma factors to prove $\theta_R^\#$ is surjective for any $R$. Finally, we describe $\theta^\#_R$ in terms of the moduli space of Langlands parameters and use this description to give an alternative proof of surjectivity in the tamely ramified case.Comment: 42 page

The Brexit car crash: using EH Carr’s What is History? to explain the result

Justin Frosini (Bocconi University) and Mark Gilbert (Johns Hopkins University) draw on EH Carr’s seminal What is History? to consider the root causes of Brexit. They identify three key factors: a British preoccupation with parliamentary sovereignty, the role of the media and the impact of migration from Central Europe

KELT-3b: A Hot Jupiter Transiting a V=9.8 Late-F Star

We report the discovery of KELT-3b, a moderately inflated transiting hot Jupiter with a mass of 1.477 (-0.067, +0.066) M_J, and radius of 1.345 +/- 0.072 R_J, with an orbital period of 2.7033904 +/- 0.000010 days. The host star, KELT-3, is a V=9.8 late F star with M_* = 1.278 (-0.061, +0.063) M_sun, R_* = 1.472 (-0.067, +0.065) R_sun, T_eff = 6306 (-49, +50) K, log(g) = 4.209 (-0.031, +0.033), and [Fe/H] = 0.044 (-0.082, +0.080), and has a likely proper motion companion. KELT-3b is the third transiting exoplanet discovered by the KELT survey, and is orbiting one of the 20 brightest known transiting planet host stars, making it a promising candidate for detailed characterization studies. Although we infer that KELT-3 is significantly evolved, a preliminary analysis of the stellar and orbital evolution of the system suggests that the planet has likely always received a level of incident flux above the empirically-identified threshold for radius inflation suggested by Demory & Seager (2011).Comment: 12 pages, 12 figures, accepted to Ap

Sparsity and Incoherence in Compressive Sampling

We consider the problem of reconstructing a sparse signal $x^0\in\R^n$ from a limited number of linear measurements. Given $m$ randomly selected samples of $U x^0$, where $U$ is an orthonormal matrix, we show that $\ell_1$ minimization recovers $x^0$ exactly when the number of measurements exceeds $$m\geq \mathrm{Const}\cdot\mu^2(U)\cdot S\cdot\log n,$$ where $S$ is the number of nonzero components in $x^0$, and $\mu$ is the largest entry in $U$ properly normalized: $\mu(U) = \sqrt{n} \cdot \max_{k,j} |U_{k,j}|$. The smaller $\mu$, the fewer samples needed. The result holds for ``most'' sparse signals $x^0$ supported on a fixed (but arbitrary) set $T$. Given $T$, if the sign of $x^0$ for each nonzero entry on $T$ and the observed values of $Ux^0$ are drawn at random, the signal is recovered with overwhelming probability. Moreover, there is a sense in which this is nearly optimal since any method succeeding with the same probability would require just about this many samples

First radial velocity results from the MINiature Exoplanet Radial Velocity Array (MINERVA)

The MINiature Exoplanet Radial Velocity Array (MINERVA) is a dedicated observatory of four 0.7m robotic telescopes fiber-fed to a KiwiSpec spectrograph. The MINERVA mission is to discover super-Earths in the habitable zones of nearby stars. This can be accomplished with MINERVA's unique combination of high precision and high cadence over long time periods. In this work, we detail changes to the MINERVA facility that have occurred since our previous paper. We then describe MINERVA's robotic control software, the process by which we perform 1D spectral extraction, and our forward modeling Doppler pipeline. In the process of improving our forward modeling procedure, we found that our spectrograph's intrinsic instrumental profile is stable for at least nine months. Because of that, we characterized our instrumental profile with a time-independent, cubic spline function based on the profile in the cross dispersion direction, with which we achieved a radial velocity precision similar to using a conventional "sum-of-Gaussians" instrumental profile: 1.8 m s$^{-1}$ over 1.5 months on the RV standard star HD 122064. Therefore, we conclude that the instrumental profile need not be perfectly accurate as long as it is stable. In addition, we observed 51 Peg and our results are consistent with the literature, confirming our spectrograph and Doppler pipeline are producing accurate and precise radial velocities.Comment: 22 pages, 9 figures, submitted to PASP, Peer-Reviewed and Accepte