Prime Submodules And A Sheaf On The Prime Spectra Of Modules

We define and investigate a sheaf of modules on the prime spectra of modules and it is shown that there is an isomorphism between the sections of this sheaf and the ideal transform module

Evolution of new regulatory functions on biophysically realistic fitness landscapes

Regulatory networks consist of interacting molecules with a high degree of mutual chemical specificity. How can these molecules evolve when their function depends on maintenance of interactions with cognate partners and simultaneous avoidance of deleterious "crosstalk" with non-cognate molecules? Although physical models of molecular interactions provide a framework in which co-evolution of network components can be analyzed, most theoretical studies have focused on the evolution of individual alleles, neglecting the network. In contrast, we study the elementary step in the evolution of gene regulatory networks: duplication of a transcription factor followed by selection for TFs to specialize their inputs as well as the regulation of their downstream genes. We show how to coarse grain the complete, biophysically realistic genotype-phenotype map for this process into macroscopic functional outcomes and quantify the probability of attaining each. We determine which evolutionary and biophysical parameters bias evolutionary trajectories towards fast emergence of new functions and show that this can be greatly facilitated by the availability of "promiscuity-promoting" mutations that affect TF specificity

Direct Search Implications for a Custodially-Embedded Composite Top

We assess current experimental constraints on the bi-doublet + singlet model of top compositeness previously proposed in the literature. This model extends the standard model's spectrum by adding a custodially-embedded vector-like electroweak bi-doublet of quarks and a vector-like electroweak singlet quark. While either of those states alone would produce a model in tension with constraints from precision electroweak data, in combination they can produce a viable model. We show that current precision electroweak data, in the wake of the Higgs discovery, accommodate the model and we explore the impact of direct collider searches for the partners of the top quark.Comment: 12 pages, 2 figures (updated figures to show sin(beta) of 0.55 rather than 0.6, to be more informative to the reader)(second update fixes a figure format issue in Fig 1f

Global Symmetries and Renormalizability of Lee-Wick Theories

In this paper we discuss the global symmetries and the renormalizibility of Lee-Wick scalar QED. In particular, in the "auxiliary-field" formalism we identify softly broken SO(1,1) global symmetries of the theory. We introduce SO(1,1) invariant gauge-fixing conditions that allow us to show in the two-field formalism directly that the number of superficially divergent amplitudes in a LW Abelian gauge theory is finite. To illustrate the renormalizability of the theory, we explicitly carry out the one-loop renormalization program in LW scalar QED and demonstrate how the counterterms required are constrained by the joint conditions of gauge- and SO(1,1)-invariance. We also compute the one-loop beta-functions in LW scalar QED and contrast them with those of ordinary scalar QED.Comment: 17 pages, 3 eps figures included. Incorporates suggestions by referee; title change

The Limits of Custodial Symmetry

We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Zbb coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner of the top quark) to the particle content of the standard model in order to implement an O(4) x U(1)_X = SU(2)_L x SU(2)_R x P_{LR} x U(1)_X symmetry that protects the Zbb coupling. This symmetry is softly broken to the gauged SU(2)_L x U(1)_Y electroweak symmetry by a Dirac mass M for the new doublet; adjusting the value of M allows us to explore the range of possibilities between the O(4)-symmetric (M to 0) and standard-model-like (M to infinity) limits. In this simple model, we find that the experimental limits on the Zbb coupling favor smaller M while the presence of a potentially sizable negative contribution to T strongly favors large M. A fit to all precision electroweak data shows that the heavy partner of the top quark must be heavier than about 3.4 TeV, making it difficult to search for at LHC. This result demonstrates that electroweak data strongly limits the amount by which the custodial symmetry of the top-quark mass generating sector can be enhanced relative to the standard model. Using an effective field theory calculation, we illustrate how the leading contributions to alpha T, alpha S and the Zbb coupling in this model arise from an effective operator coupling right-handed top-quarks to the Z-boson, and how the effects on these observables are correlated. We contrast this toy model with extra-dimensional models in which the extended custodial symmetry is invoked to control the size of additional contributions to alpha T and the Zbb coupling, while leaving the standard model contributions essentially unchanged.Comment: 19 pages, 11 eps figures. Typos correcte

Intrinsic limits to gene regulation by global crosstalk

Gene regulation relies on the specificity of transcription factor (TF) - DNA interactions. In equilibrium, limited specificity may lead to crosstalk: a regulatory state in which a gene is either incorrectly activated due to noncognate TF-DNA interactions or remains erroneously inactive. We present a tractable biophysical model of global crosstalk, where many genes are simultaneously regulated by many TFs. We show that in the simplest regulatory scenario, a lower bound on crosstalk severity can be analytically derived solely from the number of (co)regulated genes and a suitable parameter that describes binding site similarity. Estimates show that crosstalk could present a significant challenge for organisms with low-specificity TFs, such as metazoans, unless they use appropriate regulation schemes. Strong cooperativity substantially decreases crosstalk, while joint regulation by activators and repressors, surprisingly, does not; moreover, certain microscopic details about promoter architecture emerge as globally important determinants of crosstalk strength. Our results suggest that crosstalk imposes a new type of global constraint on the functioning and evolution of regulatory networks, which is qualitatively distinct from the known constraints acting at the level of individual gene regulatory elements

Review on Master Patient Index

In today's health care establishments there is a great diversity of information systems. Each with different specificities and capacities, proprietary communication methods, and hardly allow scalability. This set of characteristics hinders the interoperability of all these systems, in the search for the good of the patient. It is vulgar that, when we look at all the databases of each of these information systems, we come across different registers that refer to the same person; records with insufficient data; records with erroneous data due to errors or misunderstandings when inserting patient data; and records with outdated data. These problems cause duplicity, incoherence, discontinuation and dispersion in patient data. With the intention of minimizing these problems that the concept of a Master Patient Index is necessary. A Master Patient Index proposes a centralized repository, which indexes all patient records of a given set of information systems. Which is composed of a set of demographic data sufficient to unambiguously identify a person and a list of identifiers that identify the various records that the patient has in the repositories of each information system. This solution allows for synchronization between all the actors, minimizing incoherence, out datedness, lack of data, and a decrease in duplicate registrations. The Master Patient Index is an asset to patients, the medical staff and health care providers

Can red cell indices predict retinopathy of prematurity in preterm extreme low birth weight neonates? A single center retrospective study

Background: Improvement in neonatal health care services has led to the survival of extreme low birth weight babies over the years. This has led to increased number of retinopathy of prematurity (ROP) cases being diagnosed. Thus it becomes imperative to identify factors which can reliably predict preterm neonates at increased risk of ROP. Aims and objectives were to identify red cell indices at 4 weeks postpartum which can predict ROP in extreme low birth weight neonates.Methods: Three years ROP data in extremely low birth weight neonates was retrospectively collected and analyzed.Results: The mean gestational age at birth of the neonates in ROP group (n=149) and no-ROP group (n=191) was 28.25 (±2.71) weeks and 31.82 (±2.24) weeks, respectively (p<0.05). The mean birth weight of the neonates in ROP group and no-ROP group was 756.44 (±95.50) grams and 890 (±109.20) grams, respectively (p<0.05). In extremely low birth weight (ELBW) neonates, hematologic parameters such as hemoglobin, hematocrit, red blood cells, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values were lower and white blood cell count was higher in ROP group as compared to no-ROP group (p<0.05).Conclusions: Red cell indices may predict which extreme low birth weight neonates are at increased risk of developing retinopathy of prematurity. Being easily and widely available, red cell indices can be used as a screening test to predict ROP

Custodial Isospin Violation in the Lee-Wick Standard Model

We analyze the tension between naturalness and isospin violation in the Lee-Wick Standard Model (LW SM), by computing tree-level and fermionic one-loop contributions to the post-LEP electroweak parameters and the Zbb coupling. The model is most natural when the LW partners of the gauge bosons and fermions are light, but small partner masses can lead to large isospin violation. The post-LEP parameters yield a simple picture in the LW SM: the gauge sector contributes to Y and W only, with leading contributions arising at tree-level, while the fermion sector contributes to S-hat and T-hat only, with leading corrections arising at one loop. Hence, W and Y constrain the masses of the LW gauge bosons to satisfy M1, M2 > 2.4 TeV at 95% CL. Likewise, experimental limits on T-hat reveal that the masses of the LW fermions must satisfy Mq, Mt > 1.6 TeV at 95% CL if the Higgs mass is light and tend to exclude the LW SM for any LW fermion masses if the Higgs mass is heavy. Contributions from the top-quark sector to the Zbb coupling can be even more stringent, placing a lower bound of 4 TeV on the LW fermion masses at 95% CL.Comment: 16 pages, 8 embedded eps figure