389 research outputs found

    Microgravity science at Langley Research Center

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    Although space research is still in an embryonic state, a combination of Earth based and space flight experiments are being coupled to yield a better understanding of the complex interaction of heat and fluid flow on the dynamics of crystal growth. Continued efforts on the ground as well as additional flight opportunities are needed to continue the drive to fully understand the advantages, both scientifically and economically, of microgravity crystal growth

    On the Inadequacy of Species Distribution Models for Modelling the Spread of SARS-CoV-2: Response to AraĂşjo and Naimi

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    The ongoing pandemic of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing significant damage to public health and economic livelihoods, and is putting significant strains on healthcare services globally. This unfolding emergency has prompted the preparation and dissemination of the article “Spread of SARS-CoV-2 Coronavirus likely to be constrained by climate” by Araújo and Naimi (2020). The authors present the results of an ensemble forecast made from a suite of species distribution models (SDMs), where they attempt to predict the suitability of the climate for the spread of SARS-CoV-2 over the coming months. They argue that climate is likely to be a primary regulator for the spread of the infection and that people in warm-temperate and cold climates are more vulnerable than those in tropical and arid climates. A central finding of their study is that the possibility of a synchronous global pandemic of SARS-CoV-2 is unlikely. Whilst we understand that the motivations behind producing such work are grounded in trying to be helpful, we demonstrate here that there are clear conceptual and methodological deficiencies with their study that render their results and conclusions invalid. What follows is a response to the Araújo and Naimi article centered around three main criticisms: 1) Given the fact that SARS-CoV-2 has a primary infection pathway of direct contact, it is in an active spreading phase, and remains largely underreported in the Global South, it represents an inappropriate system for analysis using the SDM framework. 2) Even if we were to accept that an SDM framework would be applicable here, the methodology presented in the article strays far from best-practice guidelines for the application of SDMs. 3) The dissemination strategy of the authors failed to respect the frameworks of risks adhered to in other academic disciplines pertaining to public health, resulting in erroneous but well-publicised claims with broad policy implications before any scientific oversight could be applied

    Treatment of Breast Cancer in Countries with Limited Resources

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    Early and accurate diagnosis of breast cancer is important for optimizing treatment. Local treatment of early stage breast cancer involves either mastectomy or breast-conserving surgery followed by whole-breast irradiation. The pathologic and biologic properties of a woman's breast cancer may be used to estimate her probability for recurrence of and death from breast cancer, as well as the magnitude of benefit she is likely to receive from adjuvant endocrine therapy or cytotoxic chemotherapy. Ovarian ablation or suppression with or without tamoxifen is an effective endocrine therapy in the adjuvant treatment of breast cancer in premenopausal women with estrogen receptor (ER)-positive or ER-unknown breast cancer. In postmenopausal women with ER- and/or progesterone receptor (PR)-positive or PR-unknown breast cancer, the use of tamoxifen or anastrozole is effective adjuvant endocrine therapy. The benefit of tamoxifen is additive to that of chemotherapy. Cytotoxic chemotherapy also improves recurrence rates and survival, with the magnitude of benefit decreasing with increasing age. Substantial support systems are required to optimally and safely use breast-conserving approaches to local therapy or cytotoxic chemotherapy as systemic therapy. Locally advanced breast cancer (LABC) accounts for at least half of all breast cancers in countries with limited resources and has a poor prognosis. Initial treatment of LABC with anthracycline-based chemotherapy is standard and effective. Addition of a sequential, neoadjuvant taxane thereafter increases the rate of pathologic complete responses. Neoadjuvant endocrine therapy may benefit postmenopausal women with hormone receptor-positive LABC. After an initial response to neoadjuvant chemotherapy, the use of local-regional surgery is appropriate. Most women will require a radical or modified radical mastectomy. In those women in whom mastectomy is not possible after neoadjuvant chemotherapy, the use of whole-breast and regional lymph node irradiation alone is appropriate. In those women who cannot receive neoadjuvant chemotherapy because of resource constraints, mastectomy with node dissection, when feasible, may still be considered in an attempt to achieve local-regional control. After local-regional therapy, most women should receive additional systemic chemotherapy. Women with LABC that has a positive or unknown hormone receptor status benefit from endocrine therapy with tamoxifen. The treatment of LABC requires multiple disciplines and is resource intensive. Efforts to reduce the number of breast cancers diagnosed at an advanced stage thus have the potential to improve rates of survival while decreasing the use of limited resources

    Non-Abelian dynamics and heavy multiquarks, Steiner-tree confinement in hadron spectroscopy

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    A brief review is first presented of attempts to predict stable multiquark states within current models of hadron spectroscopy. Then a model combining flip-flop and connected Steiner trees is introduced and shown to lead to stable multiquarks, in particular for some configurations involving several heavy quarks and bearing exotic quantum numbers.Comment: 8 pages, 5 figures, Invited talk at the 21st European Conference on Few-Body Problems in Physics, Salamanca, Spain, August 29th--September 3rd, 2010, to appear in the Proceedings, ed.~A.~Valcarce et al., to appear in Few-Body Syste

    All-charm tetraquarks

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    We investigate four-body states with only charm quarks. Working in a large but finite oscillator basis, we present a net binding analysis to determine if the resulting states are stable against breakup into a pair of c-cbar mesons. We find several close-lying bound states in the two models we examine.Comment: 24 pgs, 10 table

    The Best and Worst of Contracts Decisions: An Anthology

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    Five hundred years ago, the common law of contract was without substance. It was form-procedure. Plaintiffs picked a form of action, and common law judges made sure someone besides themselves answered all the hard questions; the parties, a jury, or a ritual determined the winner and the remedy. Judges ran a switch on a conflicts-resolution railway. Thomas More, when Chancellor of England (1529-33), urged judges to lay tracks and control the trains. The problem, he said, was that the judges, by the verdict of the jury[,] cast off all quarrels from themselves. The judges soon assumed greater authority, taking responsibility for the law\u27s substance. The consideration requirement was in place by 1539, and judges afterwards imposed doctrine upon doctrine. Over centuries, they created the common law of contract. That law is now mature, more or less, meaning that judges have tools to fix what they want to fix, and feel free to do so. The law they created-the common law of contract-is a remarkable intellectual and political achievement

    Collage Vol. I

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    JUDY COCHRAN: Editorial MICHAEL TANGEMAN: Haikus 2-5 ELISE ALBRECHT, CURTIS PLOWGIAN: French Calligrams 6 JASON VARDEN: Waiting 7 ALEXANDER GREEN: Photo 8 EDUARDO JARAMILLO: Formas violentas 9-11 GABRIELE DILLMANN: Photo 12 MICHAEL GOLDSBERG: Funf fur Ashley 13 MEGAN CARLSON: Fur Jared (German) 14 MAGGIE GLOVER: For Jared 14-15 CHRIS FAUR: Painting 16 LINDSEY ESHELMAN: Stuhl (The Chair) 17 HALLE THOMPSON, GWENN DOBOS: Les Bouches 18 JILL BOO: Lacheln (A Smile) 19 ALEXANDER GREEN: Photo 20 JULIA GRAWEMEYER: Villanelle 21, Expressions francaises (French Figures) 22-23, Pour me rappeler (So that I\u27d remember) 24 MICHEL CLIQUET: Photo 25 CHARLES O\u27KEEFE: Photos 26-28 LINE LERYCKE: Photos 29-32 MICHEL CLIQUET: Pierre docile (Docile Stone) 29-32 LOGAN FAVIA: Ataraxia 33 AVRITA SINGH: Absence 34 RACHEL GROTHEER: Compassion 35, Ligne (Line) 36, Nuit, douce nuit (Night, gentle night) 37, Rouge (Red) 38, Bonjour Bleu (Hello Blue) 39, Ligne courbe (Curved Line) 40 AMELIA DUNLAP: Compassion 41-42 KYLE SIMPSON: Separation 43 ALEXANDER GREEN: Photo 44 GWENN DOBOS: Ataraxia 45 SARAH SLOTKIN: Separation 46 CURTIS PLOWGIAN: Absence 47 ELISA VER MERRIS: Photo 48, Attachement (Attachment) 49 JENNIFER JOHNSON: Attachement (Attachment)50 ANNA KELLY: Compassion 51 RICHARD BANAHAN: Photo 52, Mon grand-pere et moit (My grandfather and me) 53 MEREDITH KATZ: Separation 54 BRENDA HEATER: Compassion 55 ZACHARY WALSH: Ataraxia 56 MICHEL CLIQUET: Photos 57-5

    Moving magnetoencephalography towards real-world applications with a wearable system

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    Imaging human brain function with techniques such as magnetoencephalography1 (MEG) typically requires a subject to perform tasks whilst their head remains still within a restrictive scanner. This artificial environment makes the technique inaccessible to many people, and limits the experimental questions that can be addressed. For example, it has been difficult to apply neuroimaging to investigation of the neural substrates of cognitive development in babies and children, or in adult studies that require unconstrained head movement (e.g. spatial navigation). Here, we develop a new type of MEG system that can be worn like a helmet, allowing free and natural movement during scanning. This is possible due to the integration of new quantum sensors2,3 that do not rely on superconducting technology, with a novel system for nulling background magnetic fields. We demonstrate human electrophysiological measurement at millisecond resolution whilst subjects make natural movements, including head nodding, stretching, drinking and playing a ball game. Results compare well to the current state-of-the-art, even when subjects make large head movements. The system opens up new possibilities for scanning any subject or patient group, with myriad applications such as characterisation of the neurodevelopmental connectome, imaging subjects moving naturally in a virtual environment, and understanding the pathophysiology of movement disorders

    Oral tongue cancer gene expression profiling: Identification of novel potential prognosticators by oligonucleotide microarray analysis

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    <p>Abstract</p> <p>Background</p> <p>The present study is aimed at identifying potential candidate genes as prognostic markers in human oral tongue squamous cell carcinoma (SCC) by large scale gene expression profiling.</p> <p>Methods</p> <p>The gene expression profile of patients (n=37) with oral tongue SCC were analyzed using Affymetrix HG_U95Av2 high-density oligonucleotide arrays. Patients (n=20) from which there were available tumor and matched normal mucosa were grouped into stage (early vs. late) and nodal disease (node positive vs. node negative) subgroups and genes differentially expressed in tumor vs. normal and between the subgroups were identified. Three genes, <it>GLUT3</it>, <it>HSAL2</it>, and <it>PACE4</it>, were selected for their potential biological significance in a larger cohort of 49 patients via quantitative real-time RT-PCR.</p> <p>Results</p> <p>Hierarchical clustering analyses failed to show significant segregation of patients. In patients (n=20) with available tumor and matched normal mucosa, 77 genes were found to be differentially expressed (P< 0.05) in the tongue tumor samples compared to their matched normal controls. Among the 45 over-expressed genes, <it>MMP-1</it> encoding interstitial collagenase showed the highest level of increase (average: 34.18 folds). Using the criterion of two-fold or greater as overexpression, 30.6%, 24.5% and 26.5% of patients showed high levels of <it>GLUT3</it>, <it>HSAL2</it> and <it>PACE4</it>, respectively. Univariate analyses demonstrated that <it>GLUT3</it> over-expression correlated with depth of invasion (P<0.0001), tumor size (P=0.024), pathological stage (P=0.009) and recurrence (P=0.038). <it>HSAL2</it> was positively associated with depth of invasion (P=0.015) and advanced T stage (P=0.047). In survival studies, only <it>GLUT3</it> showed a prognostic value with disease-free (P=0.049), relapse-free (P=0.002) and overall survival (P=0.003). <it>PACE4</it> mRNA expression failed to show correlation with any of the relevant parameters. </p> <p>Conclusion</p> <p>The characterization of genes identified to be significant predictors of prognosis by oligonucleotide microarray and further validation by real-time RT-PCR offers a powerful strategy for identification of novel targets for prognostication and treatment of oral tongue carcinoma.</p

    Detection of Epileptogenic Cortical Malformations with Surface-Based MRI Morphometry

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    Magnetic resonance imaging has revolutionized the detection of structural abnormalities in patients with epilepsy. However, many focal abnormalities remain undetected in routine visual inspection. Here we use an automated, surface-based method for quantifying morphometric features related to epileptogenic cortical malformations to detect abnormal cortical thickness and blurred gray-white matter boundaries. Using MRI morphometry at 3T with surface-based spherical averaging techniques that precisely align anatomical structures between individual brains, we compared single patients with known lesions to a large normal control group to detect clusters of abnormal cortical thickness, gray-white matter contrast, local gyrification, sulcal depth, jacobian distance and curvature. To assess the effects of threshold and smoothing on detection sensitivity and specificity, we systematically varied these parameters with different thresholds and smoothing levels. To test the effectiveness of the technique to detect lesions of epileptogenic character, we compared the detected structural abnormalities to expert-tracings, intracranial EEG, pathology and surgical outcome in a homogeneous patient sample. With optimal parameters and by combining thickness and GWC, the surface-based detection method identified 92% of cortical lesions (sensitivity) with few false positives (96% specificity), successfully discriminating patients from controls 94% of the time. The detected structural abnormalities were related to the seizure onset zones, abnormal histology and positive outcome in all surgical patients. However, the method failed to adequately describe lesion extent in most cases. Automated surface-based MRI morphometry, if used with optimized parameters, may be a valuable additional clinical tool to improve the detection of subtle or previously occult malformations and therefore could improve identification of patients with intractable focal epilepsy who may benefit from surgery
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