Exclusive W + photon production in proton-antiproton collisions I: general formalism

We present a detailed computation of the fully exclusive cross section of p + antip --> W + photon + X with X = 0 and 1 jet in the framework of the factorization theorem and dimensional regularization. Order alpha-strong and photon bremsstrahlung contributions are discussed in the MS-bar mass factorization scheme. The resulting expressions are ready to be implemented numerically using Monte Carlo techniques to compute single and double differential cross sections and correlations between outgoing pairs of particles.Comment: ITP-SB-93-72, 40 pages, LateX. 3*4 figures in separate file. ([email protected]) ([email protected]

Incorporating next-to-leading order matrix elements for hadronic diboson production in showering event generators

A method for incorporating information from next-to-leading order QCD matrix elements for hadronic diboson production into showering event generators is presented. In the hard central region (high jet transverse momentum) where perturbative QCD is reliable, events are sampled according to the first order tree level matrix element. In the soft and collinear regions next-to-leading order corrections are approximated by calculating the differential cross section across the phase space accessible to the parton shower using the first order (virtual graphs included) matrix element. The parton shower then provides an all-orders exclusive description of parton emissions. Events generated in this way provide a physical result across the entire jet transverse momentum spectrum, have next-to-leading order normalization everywhere, and have positive definite event weights. The method is generalizable without modification to any color singlet production process.Comment: 13 pages, 9 figure

Enabling quantitative data analysis through e-infrastructures

This paper discusses how quantitative data analysis in the social sciences can engage with and exploit an e-Infrastructure. We highlight how a number of activities which are central to quantitative data analysis, referred to as ‘data management’, can benefit from e-infrastructure support. We conclude by discussing how these issues are relevant to the DAMES (Data Management through e-Social Science) research Node, an ongoing project that aims to develop e-Infrastructural resources for quantitative data analysis in the social sciences

Factorization and polarization in linearized gravity

We investigate all the four-body graviton interaction processes: $gX\rightarrow \gamma X$, $gX\rightarrow gX$, and $gg\rightarrow gg$ with $X$ as an elementary particle of spin less than two in the context of linearized gravity except the spin-3/2 case. We show explicitly that gravitational gauge invariance and Lorentz invariance cause every four-body graviton scattering amplitude to be factorized. We explore the implications of this factorization property by investigating polarization effects through the covariant density matrix formalism in each four-body graviton scattering process.Comment: 45 pages, figures are included (uses pictex), RevTe

Does Being Bored Make Us More Creative?

Boredom has traditionally been associated with a range of negative outcomes, both within the workplace and outside it. More recently, however, it has been suggested that boredom can have positive outcomes, one of which might be increased creativity. This study addressed this proposition by examining the relationship between boredom and creative potential on a range of tasks. Two studies were carried out; the first involved 80 participants taking part in either a boring writing activity or not (control group) followed by a creative task. The second study involved a further 90 participants who varied in the type of boring activity they undertook (either a boring written activity, a boring reading activity or control) and the type of creative task that followed. Results suggested that boring activities resulted in increased creativity and that boring reading activities lead to more creativity in some circumstances (such as convergent tasks) than boring written activities. The role of daydreaming as a mediator between boredom and creativity is discussed and implications are outline

Keratinocyte-Targeted Overexpression of the Glucocorticoid Receptor Delays Cutaneous Wound Healing

Delayed wound healing is one of the most common secondary adverse effects associated to the therapeutic use of glucocorticoid (GC) analogs, which act through the ligand-dependent transcription factor GC-receptor (GR). GR function is exerted through DNA-binding-dependent and –independent mechanisms, classically referred to as transactivation (TA) and transrepression (TR). Currently both TA and TR are thought to contribute to the therapeutical effects mediated by GR; however their relative contribution to unwanted side effects such as delayed wound healing is unknown. We evaluated skin wound healing in transgenic mice with keratinocyte-restricted expression of either wild type GR or a mutant GR that is TA-defective but efficient in TR (K5-GR and K5-GR-TR mice, respectively). Our data show that at days (d) 4 and 8 following wounding, healing in K5-GR mice was delayed relative to WT, with reduced recruitment of granulocytes and macrophages and diminished TNF-α and IL-1β expression. TGF-β1 and Kgf expression was repressed in K5-GR skin whereas TGF-β3 was up-regulated. The re-epithelialization rate was reduced in K5-GR relative to WT, as was formation of granulation tissue. In contrast, K5-GR-TR mice showed delays in healing at d4 but re-established the skin breach at d8 concomitant with decreased repression of pro-inflammatory cytokines and growth factors relative to K5-GR mice. Keratinocytes from both transgenic mice closed in vitro wounds slower relative to WT, consistent with the in vivo defects in cell migration. Overall, the delay in the early stages of wound healing in both transgenic models is similar to that elicited by systemic treatment with dexamethasone. Wound responses in the transgenic keratinocytes correlated with reduced ERK activity both in vivo and in vitro. We conclude that the TR function of GR is sufficient for negatively regulating early stages of wound closure, while TA by GR is required for delaying later stages of healing

β1 Integrin-Mediated Adhesion Signalling Is Essential for Epidermal Progenitor Cell Expansion

Background: There is a major discrepancy between the in vitro and in vivo results regarding the role of b1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of b1 integrins suggested that epidermis can form and be maintained in their absence, while in vitro data have shown a fundamental role for these adhesion receptors in stem/progenitor cell expansion and differentiation. Methodology/Principal Findings: To elucidate this discrepancy we generated hypomorphic mice expressing reduced b1 integrin levels on keratinocytes that developed similar, but less severe defects than mice with b1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of b1 integrin expression. A similar phenomenon was observed in aged mice with a complete, skin-specific ablation of the b1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of b1 integrin expressing keratinocytes was even further accelerated in situations of increased keratinocyte proliferation such as wound healing. Conclusions/Significance: These data demonstrate that expression of b1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis

Serological detection of antibodies against Paracoccidioides brasiliensis in dogs with leishmaniasis

The aim of this study was to detect antibodies against Paracoccidioides brasiliensis in dogs seropositive and seronegative for leishmaniasis. Sera from 836 dogs (449 positive and 387 negative to leishmaniasis) were analysed by ELISA and the immunodiffusion test using gp43 and exoantigen, respectively. The analysis of the 836 serum samples by ELISA and the immunodiffusion test showed a positivity of 67.8 % and 7.3%, respectively, for P. brasiliensis infection. The dogs positive to leishmaniasis showed a higher reactivity to gp43 (79.9%) and exoantigen (12.7%) than the negative ones (54.0% and 1.0%, respectively). The higher reactivity to P. brasiliensis antigens may be due to cross-reactivity or a co-infection of dogs by Leishmania and P. brasiliensis. The lower correlation (0.187) observed between reactivity to gp43 and Leishmania antigen reinforces the latter hypothesis

Delayed Cutaneous Wound Healing and Aberrant Expression of Hair Follicle Stem Cell Markers in Mice Selectively Lacking Ctip2 in Epidermis

This is the publisher’s final pdf. The published article is copyrighted by PLoS and can be found at: http://www.plosone.org/home.action.Background: COUP-TF interacting protein 2 [(Ctip2), also known as Bcl11b] is an important regulator of skin homeostasis, and is overexpressed in head and neck cancer. Ctip2(ep-/-) mice, selectively ablated for Ctip2 in epidermal keratinocytes, exhibited impaired terminal differentiation and delayed epidermal permeability barrier (EPB) establishment during development, similar to what was observed in Ctip2 null (Ctip2(-/-)) mice. Considering that as an important role of Ctip2, and the fact that molecular networks which underlie cancer progression partially overlap with those responsible for tissue remodeling, we sought to determine the role of Ctip2 during cutaneous wound healing. \ud \ud Methodology/Principal Findings: Full thickness excisional wound healing experiments were performed on Ctip2(L2/L2) and Ctip2(ep-/-) animals per time point and used for harvesting samples for histology, immunohistochemistry (IHC) and immunoblotting. Results demonstrated inherent defects in proliferation and migration of Ctip2 lacking keratinocytes during re-epithelialization. Mutant mice exhibited reduced epidermal proliferation, delayed keratinocyte activation, altered cell-cell adhesion and impaired ECM development. Post wounding, Ctip2(ep-/-) mice wounds displayed lack of E-Cadherin suppression in the migratory tongue, insufficient expression of alpha smooth muscle actin (alpha SMA) in the dermis, and robust induction of K8. Importantly, dysregulated expression of several hair follicle (HF) stem cell markers such as K15, NFATc1, CD133, CD34 and Lrig1 was observed in mutant skin during wound repair. \ud \ud Conclusions/Significance: Results confirm a cell autonomous role of keratinocytic Ctip2 to modulate cell migration, proliferation and/or differentiation, and to maintain HF stem cells during cutaneous wounding. Furthermore, Ctip2 in a non-cell autonomous manner regulated granulation tissue formation and tissue contraction during wound closure