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PISONIA CALAFIA (NYCTAGINACEAE) SPECIES NOVA FROM THE BAJA CALIFORNIA PENINSULA, MEXICO
José Luis León de la Luz,Rachel A. Levin
Acta botánica mexicana , 2012,
Abstract: El género Pisonia es primordialmente americano, se distribuye principalmente en regiones subtropicales y tropicales. En este trabajo se describe y documenta la nueva especie Pisonia calafia. Este taxon consiste de una relativamente peque a población en la costa de la región de Los Cabos en la península de Baja California. La principal característica que diferencia a P. calafia del resto de las especies de este género es la carencia de sulcos y glándulas en el fruto. En adición a la descripción morfológica, se documenta la afinidad evolutiva del nuevo taxon con base en el análisis filogenético de la secuencia de nrITS. Las poblaciones conocidas consisten de unas pocas docenas de individuos, seriamente amenazados por el desarrollo de proyectos turísticos en la zona.
Deepwater Horizon Oil Spill: A Review of the Planktonic Response
Raffaela M. Abbriano,Magdalena M. Carranza,Shane L. Hogle,Rachel A. Levin
Oceanography , 2011,
Abstract: On April 20, 2010, the explosion of the Deepwater Horizon (DWH) oil rig resulted in the loss of 11 lives and the largest oil spill in US history (Graham et al., 2010) and perhaps the second largest in the world, after the first Gulf War Oil Spill from Kuwait. Over the 84 days following the explosion, an estimated 6.7 x 105 mT of Louisiana Sweet Crude oil (United States Government, 2011) and up to 500,000 mT of methane and gases (Joye et al., 2011) were released from 1,480 m below the ocean's surface into the Gulf of Mexico (GoM). As oil continued to escape from the seafloor throughout the summer of 2010, images of oiled wildlife pervaded the news. These pictures, though troubling, only hinted at the fate of the plankton that form the foundation of the GoM ecosystem. This review discusses the potential effects of the DWH oil spill on the overlooked, but extremely important, members of the GoM ecosystem—the plankton. Our assessment is based on data collected in the aftermath of the DWH spill and supplemented with studies from past oil spills when information on the GoM spill was limited or unavailable. The time line we develop traces the spill from a "planktonic perspective," emphasizing the population dynamics of marine bacteria, phytoplankton, zooplankton, and fish larvae.
Correlated polymorphism in cytotype and sexual system within a monophyletic species, Lycium californicum
Ambika Kamath,Brian C. Husband,Jill S. Miller,Rachel A. Levin
- , 2016, DOI: 10.1093/aob/mcv167
Abstract: Background and Aims Polyploidy has important effects on reproductive systems in plants and has been implicated in the evolution of dimorphic sexual systems. In particular, higher ploidy is associated with gender dimorphism across Lycium species (Solanaceae) and across populations within the species Lycium californicum. Previous research on the association of cytotype and sexual system within L. californicum sampled a limited portion of the species range, and did not investigate evolutionary transitions between sexual systems. Lycium californicum occurs in arid regions on offshore islands and mainland regions in the south-western United States and Mexico, motivating a more comprehensive analysis of intraspecific variation in sexual system and cytotype across the full range of this species
An Optimized Triple Modality Reporter for Quantitative In Vivo Tumor Imaging and Therapy Evaluation
Rachel A. Levin, Csilla N. Felsen, Jin Yang, John Y. Lin, Michael A. Whitney, Quyen T. Nguyen, Roger Y. Tsien
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0097415
Abstract: We present an optimized triple modality reporter construct combining a far-red fluorescent protein (E2-Crimson), enhanced firefly luciferase enzyme (Luc2), and truncated wild type herpes simplex virus I thymidine kinase (wttk) that allows for sensitive, long-term tracking of tumor growth in vivo by fluorescence, bioluminescence, and positron emission tomography. Two human cancer cell lines (MDA-MB-231 breast cancer and HT-1080 fibrosarcoma cancer) were successfully transduced to express this triple modality reporter. Fluorescence and bioluminescence imaging of the triple modality reporter were used to accurately quantify the therapeutic responses of MDA-MB-231 tumors to the chemotherapeutic agent monomethyl auristatin E in vivo in athymic nude mice. Positive correlation was observed between the fluorescence and bioluminescence signals, and these signals were also positively correlated with the ex vivo tumor weights. This is the first reported use of both fluorescence and bioluminescence signals from a multi-modality reporter construct to measure drug efficacy in vivo.
The cardiovascular effects of aortic clamping and unclamping
A Levin
Southern African Journal of Anaesthesia and Analgesia , 2010,
Abstract: This narrative review is intended to describe the cardiovascular pathophysiology and management of aortic clamping and unclamping.
Stress, strain, ignorance and reinventing the wheel: Understanding central venous pressure
A Coetzee, A Levin
Southern African Journal of Anaesthesia and Analgesia , 2009,
Abstract: An understanding of the physics, physiology and pathophysiology underpinning the use of the central venous pressure is essential in the effective use thereof. As for any hollow organ, the interaction between intracavity volume and pressure of the container is not linear. Because of this characteristic stress and strain relationship, the central venous pressure cannot be a simple and static indication of the volume inside the container and should neither be used as such nor should across the board comparisons between central venous pressure measurements and other markers of intravascular volume be attempted. Dynamic testing of the system stiffness (elastance) of the container is an effective but still indirect manner to gauge the particular intracavity volume.
Cohomology of the complement to an elliptic arrangement
A. Levin,A. Varchenko
Mathematics , 2011,
Abstract: We consider the complement to an arrangement of hyperplanes in a cartesian power of an elliptic curve and describe its cohomology with coefficients in a nontrivial rank one local system.
Early Detection of Malignant Pleural Mesothelioma in Asbestos-Exposed Individuals with a Noninvasive Proteomics-Based Surveillance Tool
Rachel M. Ostroff, Michael R. Mehan, Alex Stewart, Deborah Ayers, Edward N. Brody, Stephen A. Williams, Stephen Levin, Brad Black, Michael Harbut, Michele Carbone, Chandra Goparaju, Harvey I. Pass
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0046091
Abstract: Background Malignant pleural mesothelioma (MM) is an aggressive, asbestos-related pulmonary cancer that is increasing in incidence. Because diagnosis is difficult and the disease is relatively rare, most patients present at a clinically advanced stage where possibility of cure is minimal. To improve surveillance and detection of MM in the high-risk population, we completed a series of clinical studies to develop a noninvasive test for early detection. Methodology/Principal Findings We conducted multi-center case-control studies in serum from 117 MM cases and 142 asbestos-exposed control individuals. Biomarker discovery, verification, and validation were performed using SOMAmer proteomic technology, which simultaneously measures over 1000 proteins in unfractionated biologic samples. Using univariate and multivariate approaches we discovered 64 candidate protein biomarkers and derived a 13-marker random forest classifier with an AUC of 0.99±0.01 in training, 0.98±0.04 in independent blinded verification and 0.95±0.04 in blinded validation studies. Sensitivity and specificity at our pre-specified decision threshold were 97%/92% in training and 90%/95% in blinded verification. This classifier accuracy was maintained in a second blinded validation set with a sensitivity/specificity of 90%/89% and combined accuracy of 92%. Sensitivity correlated with pathologic stage; 77% of Stage I, 93% of Stage II, 96% of Stage III and 96% of Stage IV cases were detected. An alternative decision threshold in the validation study yielding 98% specificity would still detect 60% of MM cases. In a paired sample set the classifier AUC of 0.99 and 91%/94% sensitivity/specificity was superior to that of mesothelin with an AUC of 0.82 and 66%/88% sensitivity/specificity. The candidate biomarker panel consists of both inflammatory and proliferative proteins, processes strongly associated with asbestos-induced malignancy. Significance The SOMAmer biomarker panel discovered and validated in these studies provides a solid foundation for surveillance and diagnosis of MM in those at highest risk for this disease.
Body-focused Anxiety in Women: Associations with Internalization of the Thin-ideal, Dieting Frequency, Body Mass Index and Media Effects  [PDF]
Aileen Pidgeon, Rachel A. Harker
Open Journal of Medical Psychology (OJMP) , 2013, DOI: 10.4236/ojmp.2013.24B004
Abstract:

Exposure to media that portrays thin women as ideal and attractive can lead to women internalizing the thin ideal, which results in incorporating societal standards of thinness into belief systems. Internalization of the thin-ideal is associated with numerous detrimental effects on women, including decreased levels of self-esteem and increased levels of body-focused anxiety, negative emotions and disordered eating. The present study utilized a sample of women (N = 208) aged between 18 and 67 years (M = 29.44, SD = 13.08) to examine the relationship between internalization of the thin- ideal, body-focused anxiety, body mass index (BMI), and dieting frequency. Correlational, regression and mediation analyses conducted on the data showed that internalization of the thin-ideal, BMI and dieting frequency significantly contributed to body-focused anxiety in women. In addition, body-focused anxiety fully mediated the relationship between internalization of the thin-ideal and dieting frequency among women. BMI did not moderate the relationship between internalization of the thin-ideal and body-focused, indicating that women who internalize the thin-ideal are less vulnerable to dieting unless experiencing body-focused anxiety. The results of the current study enhance our understanding of the relationship between internalization of the thin-ideal, body-focused anxiety, BMI, and dieting frequency among women. Clinical implications will be discussed.

Using Informatics to Manage and Measure Performance of Large Femtocell Networks  [PDF]
Jay A Weitzen, Rachel Wakim
Journal of Data Analysis and Information Processing (JDAIP) , 2015, DOI: 10.4236/jdaip.2015.32003
Abstract: This paper describes the analytics platform and algorithms that are used to manage network performance of large femtocell networks with close to one million femtocells from multiple vendors. The system incorporates parallel processing of the data, rule based artificial intelligence, and large scale automated data analysis and data mining.
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