Calabi-Yau threefolds with large h^{2, 1}

We carry out a systematic analysis of Calabi-Yau threefolds that are elliptically fibered with section ("EFS") and have a large Hodge number h^{2, 1}. EFS Calabi-Yau threefolds live in a single connected space, with regions of moduli space associated with different topologies connected through transitions that can be understood in terms of singular Weierstrass models. We determine the complete set of such threefolds that have h^{2, 1} >= 350 by tuning coefficients in Weierstrass models over Hirzebruch surfaces. The resulting set of Hodge numbers includes those of all known Calabi-Yau threefolds with h^{2, 1} >= 350, as well as three apparently new Calabi-Yau threefolds. We speculate that there are no other Calabi-Yau threefolds (elliptically fibered or not) with Hodge numbers that exceed this bound. We summarize the theoretical and practical obstacles to a complete enumeration of all possible EFS Calabi-Yau threefolds and fourfolds, including those with small Hodge numbers, using this approach.Comment: 44 pages, 5 tables, 5 figures; v2: minor corrections; v3: minor corrections, moved figure; v4: typo in Table 2 correcte

Chemical differences of atherosclerotic plaques in native and bypass human coronary arteries and diseased and non-diseased human aortas

ABSTRACT Cardiovascular disease, primarily atherosclerosis involves a number of distinct processes that are associated with plaque development. The use of differential gel electrophoresis to determine differences between proteins produced in native and bypass coronary arteries from the same heart has been studied. The analytical techniques presented in this study to characterize plaque samples include two dimensional gel electrophoresis, sodium dodecylsulfate polyacrylamide gel electrophoresis, mass spectrometry, differential gel electrophoresis, and high performance liquid chromatography. An overview of the stages involved in atherosclerosis and the theories implicated in the manifestation of atherosclerosis was presented. A design study using the Box Behnken method was used to optimize the components in lysis buffer to solubilize the membrane proteins present in the intima in atherosclerotic plaques. The number of proteins located as spots in the gel were optimized in this study. The isolation and characterization of proteins in intima and media extracts of diseased aortas were separated using two dimensional gel electrophoresis followed by excision of gel spots and tryptic digestion to peptides. Mass analysis (MS and MS/MS) of the digested peptides with a linear quadrupole trap Fourier transform ion cyclotron resonance mass spectrometer was used to determine the amino acid sequences. Protein extracts of normal and diseased aortas and native and bypass arteries were analyzed using differential gel electrophoresis system. Cydye 3 (1-(5-carboxypentyl)-1`-propylindocarbocyanine halide N-hydroxy-succinimidyl ester) and Cydye 5 (1-(5-carboxypentyl)-1´-methylindodicarbocyanine halide N-hydroxy-succinimidyl ester) are fluorescent dyes used in our study to identify differentially expressed proteins of interest in the same gel using matrix assisted laser desorption ionization time-of-flight mass spectrometry. Several proteins in normal and diseased tissues were identified A study of the separation and quantification of cholesterol and cholesteryl esters was performed using reverse phase high performance liquid chromatograph interfaced with atmospheric pressure chemical ionization probe that was introduced into a quadrupole mass analyzer. Thirty-five samples were analyzed by principal component analysis that produced two distinct age groups based on age. In addition, a disease severity index was generated from the data. This study concluded that age and low disease severity index were indicators of the atherogenic states of the extracts analyzed

The Land-Grant Colleges for Negroes 1914-1945: A Study in Higher Education

This study is part II of, The Development of Higher Education for Negroes with Special Reference to the Land-Grant Colleges. The original problem arose out of the general field of the development of American democracy as it expressed itself in the development of opportunities for all its people through a medium of education. C. B. White wrote on this problem and found that higher education for Negroes between 1890 and 1914 was inadequate. Negro higher education has been singled out because of the fact that it has some special problems which have come out of the Negroes\u27 abnormal relationship to American life, negroes constitute a fourth of the population of the South, and it is in this section that three-fourths of the Negroes in America live. Here the Negro is among the multitudes of those who are ill-clothed, ill-housed, and ill-fed. He is a victim of a prevailing cultural lag and of an unsatisfactory economy. Higher educational institutions for Negroes are located largely in the South and thus are a part of the south, under a dual system of education based upon a tax structure inadequate to the efficient support of a single system of education even for white youth, the Negro must be taught the essentials of democratic living. The educational inequalities and economic disadvantage of southern regions, together with the Negro\u27s special handicaps within the area, make it impossible to consider adequately the higher education of Negroes apart from the complex of problems inherent in a dual society and the Negro\u27s segregated life. It is increasingly evident that Negroes have developed along educational and cultural lines more rapidly than our social systems have changed in adjustment to the situation. This disequilibrium appears in the occupational limitations placed on Negroes of ability and training; it is also apparent in the number of negroes ready for graduate and professional training in areas in which inadequate provisions and sometimes no provision has been made for meeting their needs. This paper will attempt to assemble and interpret such social, economic, and educational date as to indicate programs of higher education needed, and to indicate the nature of educational service now rendered to meet those needs

A comparison of stage-specific all-cause mortality between testicular sex cord stromal tumors and germ cell tumors: results from the National Cancer Database.

BackgroundTesticular sex cord stromal tumors (SCSTs) are managed similarly to germ cell tumors (GCTs); however, few studies have directly compared outcomes between these tumor types. Using the National Cancer Database (NCDB), we sought to compare overall and stage-specific all-cause mortality (ACM) between SCSTs versus GCTs.MethodsNCDB was queried for patients diagnosed with SCSTs and GCTs between 2004 and 2013. Descriptive statistics were used to compare sociodemographic and clinical characteristics between groups. Univariable and multivariable Cox proportional hazards regression analyses were used to assess associations with ACM.ResultsWe identified 42,192 patients diagnosed with testicular cancer between 2004 and 2013, with 280 having SCSTs and 41,912 patients having GCTs. Median age for SCSTs and GCTs was 45 (interquartile range [IQR] 34-59) and 34 (IQR 27-43), respectively (p < 0.001). Median follow-up was 39 and 52 months, respectively. Overall, patients with SCSTs had greater risk of ACM compared to those with GCTs (HR 1.69, 95% CI 1.14-2.50). Private insurance, greater education, and fewer comorbidities were associated with reduced risk of ACM (p < 0.05 for all). Among those with stage I disease, tumor type was not associated with ACM on multivariable analysis. Among those with stage II/III disease, patients with SCSTs had increased risk of ACM compared to patients with GCTs (HR 3.29, 95% CI 1.89-5.72).ConclusionsPatients with advanced SCSTs had worse survival outcomes compared to those with advanced GCTs. These data suggest a need for further investigation to ascertain effective management recommendations for SCSTs

A once-daily dose of tadalafil for erectile dysfunction: compliance and efficacy

Selective phosphodiesterase type 5 inhibitors (PDE5Is) have revolutionized the treatment of erectile dysfunction (ED) in men. As an on-demand treatment, PDE5Is have excellent efficacy and safety in the treatment of ED due to a broad spectrum of etiologies. Nevertheless, these drugs do have side-effect profiles that are troublesome to some patients, eg, headache, dyspepsia, myalgia, etc. Furthermore, many patients and their partners dislike the necessity of on-demand treatment for ED, citing a desire for greater spontaneity with sexual interactions. In 2008, approximately 10 years after the release of the first commercially available PDE5I, a paradigm shift in the management of ED occurred with the approval of once-daily dose of tadalafil by the US Food and Drug Administration for the management of ED. The prolonged half-life of tadalafil lends itself well to this dosing regimen and conveys the advantage of separating medication from sexual interactions; lower dose therapy also carries the theoretical benefit of lower incidence of side effects. In this study, we review the current state of the art with respect to this new management strategy for ED, highlighting published reports of the efficacy and tolerability of the daily dose tadalafil regimen

Systematic Assessment of Resistance to Extension Organizational Change: Evidence from the Alabama Cooperative Extension System

This article provides a case-study example of how Extension administrators may help their organizations advance toward institutionalization of change and restructuring through systematic participation of agents and specialists in change assessments. Citing two change assessments in the Alabama Cooperative Extension System, this article offers a framework Extension administrators can adopt to decrease resistance to organizational changes. Action steps are discussed in terms of identifying specific changes resisted and embraced by Extension stakeholders. Though this participative approach does not guarantee complete acceptance of changes by organizational stakeholders, the approach can help evolving Extension organizations advance toward sound institutionalization of changes

Phorbol myristate acetate stimulates microtubule and 10-nm filament extension and lysosome redistribution in mouse macrophages

Phorbol myristate acetate (PMA) stimulates cell spreading and fluid-phase pinocytosis in mouse peritoneal macrophages. Colchicine (10(-5) M) and cytochalasin B (10(-5) M) abolish PMA stimulated pinocytosis but have little effect on cellular spreading (Phaire-Washington et al., 1980, J. Cell Biol., 86:634-640). We report here that PMA also alters the organization of the cytoskeleton and the distrubution of organelles in these cells. Neither control nor PMA-treated macrophages contain actin cables. PMA-treated resident thioglycolate-elicited macrophages exhibit beneath their substrate-adherent membranes many randomly distributed punctate foci that stain brightly for actin. The appearance and distribution of these actin-containing foci are not altered by colchicine (10(-5) M) or cytochalasin B (10(-5) M). In thioglycolate-elicited macrophages PMA causes the extension and radial organization of microtubules and 10-nm filaments and promotes the movement of secondary lysosomes from their perinuclear location to the peripheral cytoplasm. Depending upon the concentration of PMA used, 45-71% of thioglycolate-elicited macrophages and 32-44% of proteose-peptone-elicited macrophages and numerous lysosomes, radiating from the centrosphere region, arranged linearly along microtubule and 10-nm filament bundles. Colchicine (10(-5) M) and podophyllotoxin (10(-5) M) prevent the radial redistribution of microtubules, 10-nm filaments, and lysosomes in these cells. Cytochalasins B and D (10(-5) M) have no inhibitory effects on these processes. These findings indicate that microtubules and 10-nm filaments respond in a coordinated fashion to PMA and to agents that inhibit microtubule function; they suggest that these cytoskeletal elements regulate the movement and distribution of lysosomes in the macrophage cytoplasm

Open string field theory without open strings

Witten's cubic open string field theory is expanded around the perturbatively stable vacuum, including all scalar fields at levels 0, 2, 4 and 6. The (approximate) BRST cohomology of the theory is computed, giving strong evidence for the absence of physical open string states in this vacuum.Comment: 12 pages, 1 figure, LaTeX; v2: reference adde

Identification of pathologic features associated with “ulcerative colitis-like” Crohn’s disease

AIM: To identify pathologic features associated with this “ulcerative colitis (UC)-like” subgroup of Crohn’s disease (CD). METHODS: Seventeen subjects diagnosed as having UC who underwent proctocolectomy (RPC) from 2003-2007 and subsequently developed CD of the ileal pouch were identified. UC was diagnosed based on pre-operative clinical, endoscopic, and pathologic studies. Eighteen patients who underwent RPC for UC within the same time period without subsequently developing CD were randomly selected and used as controls. Pathology reports and histological slides were reviewed for a wide range of gross and microscopic pathological features, as well as extent of disease. The demographics, gross description and histopathology of the resection specimens were reviewed and compared between the two groups. RESULTS: Patients with “UC-like” CD were on average 13 years younger than those with “true” UC (P < 0.01). More severe disease in the proximal involved region and active ileitis with/without architectural distortion were observed in 6 of 17 (35%) and 7 of 17 (41%) “UC-like” CD cases, respectively, but in none of the “true” UC cases (P < 0.05). Active appendicitis occurred in 8 of 16 (50%) “UC-like” CD cases but in only two (11%) “true” UC cases (P < 0.05). Conspicuous lamina propria neutrophils were more specific for “UC-like” CD (76% vs 22%, P < 0.05). In addition, prominent lymphoid aggregates tended to be more common in “UC-like” CD (P = 0.07). The “true” UC group contained a greater number of cases with severe activity (78% vs 47%). Therefore, the features more commonly seen in “UC-like” CD were not due to a more severe disease process. Crohn’s granulomas and transmural inflammation in non-ulcerated areas were absent in both groups. CONCLUSION: More severe disease in the proximal involved region, terminal ileum involvement, active appendicitis, and prominent lamina propria neutrophils may be morphological factors associated with “UC-like” CD