71 research outputs found

    On the Possibility of Optical Unification in Heterotic Strings

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    Recently J. Giedt discussed a mechanism, entitled optical unification, whereby string scale unification is facilitated via exotic matter with intermediate scale mass. This mechanism guarantees that a virtual MSSM unification below the string scale is extrapolated from the running of gauge couplings upward from M_Z^o when an intermediate scale desert is assumed. In this letter we explore the possibility of optical unification within the context of weakly coupled heterotic strings. In particular, we investigate this for models of free fermionic construction containing the NAHE set of basis vectors. This class is of particular interest for optical unification, because it provides a standard hypercharge embedding within SO(10), giving the standard k_Y = 5/3 hypercharge level, which was shown necessary for optical unification. We present a NAHE model for which the set of exotic SU(3)_C triplet/anti-triplet pairs, SU(2)_L doublets, and non-Abelian singlets with hypercharge offers the possibility of optical unification. Whether this model can realize optical unification is conditional upon these exotics not receiving Fayet-Iliopoulos (FI) scale masses when a flat direction of scalar vacuum expectation values is non-perturbatively chosen to cancel the FI D-term, xi, generated by the anomalous U(1)-breaking Green-Schwarz-Dine-Seiberg-Wittten mechanism. A study of perturbative flat directions and their phenomenological implications for this model is underway. This paper is a product of the NFS Research Experiences for Undergraduates and the NSF High School Summer Science Research programs at Baylor University.Comment: 16 pages. Standard Late

    Genetic Sharing with Cardiovascular Disease Risk Factors and Diabetes Reveals Novel Bone Mineral Density Loci.

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    Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False Discovery Rate (FDR) method to identify single nucleotide polymorphisms (SNPs) associated with BMD by leveraging cardiovascular disease (CVD) associated disorders and metabolic traits. By conditioning on SNPs associated with the CVD-related phenotypes, type 1 diabetes, type 2 diabetes, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein, triglycerides and waist hip ratio, we identified 65 novel independent BMD loci (26 with femoral neck BMD and 47 with lumbar spine BMD) at conditional FDR < 0.01. Many of the loci were confirmed in genetic expression studies. Genes validated at the mRNA levels were characteristic for the osteoblast/osteocyte lineage, Wnt signaling pathway and bone metabolism. The results provide new insight into genetic mechanisms of variability in BMD, and a better understanding of the genetic underpinnings of clinical comorbidity

    Chemotherapy regimens and treatment protocols for laryngeal cancer.

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    Item does not contain fulltextIMPORTANCE OF THE FIELD: Laryngeal cancer has been the model of curative-intent organ-preserving therapies in clinical oncology. Although the optimal care of patients with laryngeal cancer is truly multidisciplinary, with progressive advances in surgical, radiation, and medical oncology, the development of effective systemic therapies has been a major component of the therapeutic arsenal against laryngeal cancer. AREAS COVERED IN THIS REVIEW: This review will discuss the rapidly evolving roles of chemotherapy in the management of locally advanced and metastatic laryngeal cancer. WHAT THE READER WILL GAIN: The reader will gain a historical perspective on this evolution in treatment and will appreciate current treatment challenges and promising future directions in optimizing therapeutic efficacy in functional larynx preservation and in patient survival. TAKE HOME MESSAGE: The treatment of most patients with laryngeal cancer with systemic therapy represents an opportunity to positively impact functional outcomes with an anatomically and functionally preserved larynx. Future challenges include identification of novel therapies and optimizing therapy protocols for individualized patient care.1 juni 201

    Concurrent chemoradiation for adenoid cystic carcinoma of the head and neck

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    Background We performed a retrospective review of patients with nonresected head and neck adenoid cystic carcinoma (ACC) treated with concurrent chemoradiation. Methods Sixteen patients (nasopharynx 7, oropharynx 4, trachea 3, oral and nasal cavity 1 each) were treated at 3 tertiary care centers. Six patients received intraarterial cisplatin and 10 received intravenous cisplatin or carboplatin concurrently with radiation. Results Thirteen patients are alive, 7 without signs of disease with a median follow-up of 61 months. Tumor progression was noted in 8 patients (50%) (distant metastasis in 5 patients and local tumor progression in 3 patients) with a median time to progression of 25 months (range, 452 months). Overall survival (OS), progression-free survival (PFS), and local progressionfree survival (LPFS) rates at 5 years were 87%, 39%, and 61%, respectively. Conclusion Concurrent chemoradiation is a feasible treatment option and may lead to sustained locoregional tumor control in patients with nonresected ACC of the head and neck. (C) 2011 Wiley Periodicals, Inc. Head Neck, 2012Biological, physical and clinical aspects of cancer treatment with ionising radiatio
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