16,344 research outputs found
Phenomenological Consequences of Soft Leptogenesis
Soft supersymmetry breaking terms involving heavy singlet sneutrinos can be
the dominant source of leptogenesis. The relevant range of parameters is
different from standard leptogenesis: a lighter Majorana mass, M < 10^9 GeV
(allowing a solution of the gravitino problem), and smaller Yukawa couplings,
Y_N < 10^{-4}. We investigate whether the various couplings of the singlet
sneutrinos, which are constrained by the requirement of successful `soft
leptogenesis', can have observable phenomenological consequences. Specifically,
we calculate the contributions of the relevant soft supersymmetric breaking
terms to the electric dipole moments of the charged leptons and to lepton
flavor violating decays. Our result is that these contributions are small.Comment: 11 pages, 1 figure; v2: an additional contribution is considered
(modifying: fig. 1, eq. 10-13, 22) and a reference added. Conclusions
unchange
Genomic homogeneity in fibrolamellar carcinomas
Background-Fibrolamellar carcinoma (FLC) is a variant of hepatocellular carcinoma (HCC) with distinctive clinical and histological features. To date there have been few studies on the genotypic aspects of FLC and no previous attempts have been made to use the arbitrarily primed-polymerase chain reaction (AF-FCR) technique to detect genetic alterations in this disease.Aim-The aim of this study was to assess the degree of genomic heterogeneity of FEC using the AP-PCR technique. Methods-A fetal of 50 tissue samples of primary and metastatic FLCs from seven patients were microdissected. AP-PCR amplification of each genomic DNA sample was carried out using two arbitrary primers.Results-DNA fingerprints of the primary FLCs and all their metastatic lesions (both synchronous and metachronous disease) were identical in an individual patient. The fingerprints were different between tumours of different patients. No evidence of intratumour heterogeneity was observed.Conclusions-Such genomic homogeneity in FLCs may explain their indolent growth. The absence of clonal evolution, which is present in other tumours (particularly HCCs), may explain the distinct behaviour in this tumour. The tumorigenic pathway and degree of somatic genomic changes in this disease may be less complex than in HCC
Seesaw Mass Matrix Model of Quarks and Leptons with Flavor-Triplet Higgs Scalars
In a seesaw mass matrix model M_f = m_L M_F^{-1} m_R^\dagger with a universal
structure of m_L \propto m_R, as the origin of m_L (m_R) for quarks and eptons,
flavor-triplet Higgs scalars whose vacuum expectation values v_i are
proportional to the square roots of the charged lepton masses m_{ei}, i.e. v_i
\propto \sqrt{m_{ei}}, are assumed. Then, it is investigated whether such a
model can explain the observed neutrino masses and mixings (and also quark
masses and mixings) or not.Comment: version accepted by EPJ
A Unified Description of Quark and Lepton Mass Matrices in a Universal Seesaw Model
In the democratic universal seesaw model, the mass matrices are given by
\bar{f}_L m_L F_R + \bar{F}_L m_R f_R + \bar{F}_L M_F F_R (f: quarks and
leptons; F: hypothetical heavy fermions), m_L and m_R are universal for up- and
down-fermions, and M_F has a structure ({\bf 1}+ b_f X) (b_f is a
flavour-dependent parameter, and X is a democratic matrix). The model can
successfully explain the quark masses and CKM mixing parameters in terms of the
charged lepton masses by adjusting only one parameter, b_f. However, so far,
the model has not been able to give the observed bimaximal mixing for the
neutrino sector. In the present paper, we consider that M_F in the quark
sectors are still "fully" democratic, while M_F in the lepton sectors are
partially democratic. Then, the revised model can reasonably give a nearly
bimaximal mixing without spoiling the previous success in the quark sectors.Comment: 7 pages, no figur
Scotland, Catalonia and the “right” to self-determination: a comment suggested by Kathryn Crameri’s “Do Catalans Have the Right to Decide?
No abstract available
Evaluation of a New Recombinant K39 Rapid Diagnostic Test for Sudanese Visceral Leishmaniasis.
A new rK39 rapid diagnostic dipstick test (DiaMed-IT-Leish) was compared with aspiration and a direct agglutination test (DAT) for diagnosis of visceral leishmaniasis (VL) in 201 parasitologically confirmed cases, 133 endemic controls, and in 356 clinical suspects in disease-endemic and -epidemic areas in Sudan. The sensitivity of the rK39 test in parasitologically confirmed VL cases was 90%, whereas the specificity in disease-endemic controls was 99%. The sensitivity of the DAT was 98%. In clinically suspected cases, the sensitivity of the rK39 test was 81% and the specificity was 97%. When compared with the diagnostic protocol based on the DAT and aspiration used by Médecins sans Frontières in epidemic situations, the positive predictive value was 98%, and the negative predictive value was 71%. This rK39 rapid diagnostic test is suitable for screening as well as diagnosis of VL. Further diagnostic work-up of dipstick-negative patients with clinically suspected VL is important. The ease and convenience of the dipstick test will allow decentralization and improved access to care in disease-endemic areas in Sudan
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Reaching the world outside: cultural representation and perceptions of global citizenship in Japanese elementary school English textbooks
Research on the representation of culture in language textbooks rarely incorporates the concept of global citizenship, despite its increasing relevance to language education in our globalising world. To address this critique, a mixed-method study was conducted to investigate cultural representation in Japanese elementary school English textbooks, and the degree to which students feel connected to the concept of global citizenship. Content analysis of Japanese textbooks and thematic analysis of student and teacher interviews found that the texts are culturally simplistic and did not help this population of students fully realise the values of global citizenship. Meaningful cultural representation may reinforce cultural awareness, open-mindedness, and social responsibility – the core dimensions of global citizenship. To this end, future English curricula would benefit from supplementary authentic materials, cultural exchange experiences, and explicit discussions of culture between teachers and students
Universal Seesaw Mass Matrix Model with an S_3 Symmetry
Stimulated by the phenomenological success of the universal seesaw mass
matrix model, where the mass terms for quarks and leptons f_i (i=1,2,3) and
hypothetical super-heavy fermions F_i are given by \bar{f}_L m_L F_R +\bar{F}_L
m_R f_R + \bar{F}_L M_F F_R + h.c. and the form of M_F is democratic on the
bases on which m_L and m_R are diagonal, the following model is discussed: The
mass terms M_F are invariant under the permutation symmetry S_3, and the mass
terms m_L and m_R are generated by breaking the S_3 symmetry spontaneously. The
model leads to an interesting relation for the charged lepton masses.Comment: 8 pages + 1 table, latex, no figures, references adde
Advance care planning in 21st century Australia: a systematic review and appraisal of online advance care directive templates against national framework criteria
Objectives A drive to promote advance care planning at a population level has led to a proliferation of online advance care directive (ACD) templates but little information to guide consumer choice. The current study aimed to appraise the quality of online ACD templates promoted for use in Australia.
Methods A systematic review of online Australian ACD templates was conducted in February 2014. ACD templates were identified via Google searches, and quality was independently appraised by two reviewers against criteria from the 2011 report A National Framework for Advance Care Directives. Bias either towards or against future medical treatment was assessed using criteria designed to limit subjectivity.
Results Fourteen online ACD templates were included, all of which were available only in English. Templates developed by Southern Cross University best met the framework criteria. One ACD template was found to be biased against medical treatment – the Dying with Dignity Victoria Advance Healthcare Directive.
Conclusions More research is needed to understand how online resources can optimally elicit and record consumers’ individual preferences for future care. Future iterations of the framework should address online availability and provide a simple rating system to inform choice and drive quality improvement
Evolution of the Yukawa coupling constants and seesaw operators in the universal seesaw model
The general features of the evolution of the Yukawa coupling constants and
seesaw operators in the universal seesaw model with det M_F=0 are investigated.
Especially, it is checked whether the model causes bursts of Yukawa coupling
constants, because in the model not only the magnitude of the Yukawa coupling
constant (Y_L^u)_{33} in the up-quark sector but also that of (Y_L^d)_{33} in
the down-quark sector is of the order of one, i.e., (Y_L^u)_{33} \sim
(Y_L^d)_{33} \sim 1. The requirement that the model should be calculable
perturbatively puts some constraints on the values of the intermediate mass
scales and tan\beta (in the SUSY model).Comment: 21 pages, RevTex, 10 figure
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