Looking for the left sneutrino LSP with displaced-vertex searches

We analyze a displaced dilepton signal expected at the LHC for a tau left sneutrino as the lightest supersymmetric particle with a mass in the range $45$-$100$ GeV. The sneutrinos are pair produced via a virtual $W$, $Z$ or $\gamma$ in the $s$ channel and, given the large value of the tau Yukawa coupling, their decays into two dileptons or a dilepton plus missing transverse energy from neutrinos can be significant. The discussion is carried out in the $\mu \nu$SSM, where the presence of $R$-parity violating couplings involving right-handed neutrinos solves the $\mu$ problem and can reproduce the neutrino data. To probe the tau left sneutrinos we compare the predictions of the $\mu \nu$SSM with the ATLAS search for long-lived particles using displaced lepton pairs in $pp$ collisions at $\sqrt s= 8$ TeV, allowing us to constrain the parameter space of the model. We also consider an optimization of the trigger requirements used in existing displaced-vertex searches by means of a High Level Trigger that exploits tracker information. This optimization is generically useful for a light metastable particle decaying into soft charged leptons. The constraints on the sneutrino turn out to be more stringent. We finally discuss the prospects for the $13$ TeV LHC searches as well as further potential optimizations.Comment: Version published in PRD, discussions expanded, references added, LEP and LHC constraints discussed in more detail, 29 pages, 9 figures, 9 table

Explaining muon g-2 data in the μνSSM

We analyze the anomalous magnetic moment of the muon $$g-2$$ in the $$\mu \nu$$SSM. This R-parity violating model solves the $$\mu$$ problem reproducing simultaneously neutrino data, only with the addition of right-handed neutrinos. In the framework of the $$\mu \nu$$SSM, light left muon-sneutrino and wino masses can be naturally obtained driven by neutrino physics. This produces an increase of the dominant chargino-sneutrino loop contribution to muon $$g-2$$, solving the gap between the theoretical computation and the experimental data. To analyze the parameter space, we sample the $$\mu \nu$$SSM using a likelihood data-driven method, paying special attention to reproduce the current experimental data on neutrino and Higgs physics, as well as flavor observables such as B and $$\mu$$ decays. We then apply the constraints from LHC searches for events with multi-leptons + MET on the viable regions found. They can probe these regions through chargino–chargino, chargino–neutralino and neutralino–neutralino pair production. We conclude that significant regions of the parameter space of the $$\mu \nu \mathrm{SSM}$$ can explain muon $$g-2$$ data

Searching for sbottom LSP at the LHC

Assuming that the sbottom is the lightest supersymmetric particle (LSP), we carry out an analysis of the relevant signals expected at the LHC. The discussion is established in the framework of the $\mu\nu$SSM, where the presence of $R$-parity violating couplings involving right-handed neutrinos solves simultaneously the $\mu$-problem and the accommodation of neutrino masses and mixing angles. The sbottoms are pair produced at the LHC, decaying to a lepton and a top quark or a neutrino and a bottom quark. The decays can be prompt or displaced, depending on the regions of the parameter space of the model. We focus the analysis on the right sbottom LSP, since the left sbottom is typically heavier than the left stop because of the D-term contribution. We compare the predictions of this scenario with ATLAS and CMS searches for prompt and long-lived particles. To analyze the parameter space we sample the $\mu\nu$SSM for a right sbottom LSP, paying special attention to reproduce the current experimental data on neutrino and Higgs physics, as well as flavor observables. For displaced (prompt) decays, our results translate into lower limits on the mass of the right sbottom LSP of about $1041$ GeV ($1070$ GeV). The largest possible value found for the decay length is about $3.5$ mm.Comment: 26 pages, 4 figures, 3 tables, 1 appendix. Analysis of the stop LSP at the LHC carried out in arXiv:2111.1321

The new (g−2)μ(g-2)_\mu result and the μν\mu\nuSSM

The $\mu\nu$SSM is a highly predictive alternative model to the MSSM. In particular, the electroweak sector of the model can explain the longstanding discrepancy between the experimental result for the anomalous magnetic moment of the muon, $(g-2)_\mu$, and its Standard Model prediction, while being in agreement with all other theoretical and experimental constraints. The recently published MUON G-2 result is within $0.8\,\sigma$ in agreement with the older BNL result on $(g-2)_\mu$. The combined result was announced as $a_\mu^{\rm exp} = (11659206.1 \pm 4.1) \times 10^{-10}$, yielding a new deviation from the Standard Model prediction of $\Delta a_\mu = (25.1 \pm 5.9) \times 10^{-10}$, corresponding to $4.2\,\sigma$. Using this improved bound we update the analysis in the $\mu\nu$SSM as presented in Ref. [1] and set new limits on the allowed parameters space of the electroweak sector of the model. We conclude that significant regions of the model can explain {the new} $(g-2)_\mu$ data.Comment: 30 pages, 9 figures, 1 table. Follow-up of arXiv:1912.0416

Heterogeneous oxygen availability affects the titer and topology but not the fidelity of plasmid DNA produced by Escherichia coli

Jaen KE, Sigala J-C, Olivares-Hernandez R, Niehaus K, Lara AR. Heterogeneous oxygen availability affects the titer and topology but not the fidelity of plasmid DNA produced by Escherichia coli. BMC BIOTECHNOLOGY. 2017;17(1): 60.Background: Dissolved oxygen tension (DOT) is hardly constant and homogenously distributed in a bioreactor, which can have a negative impact in the metabolism and product synthesis. However, the effects of DOT on plasmid DNA (pDNA) production and quality have not been thoroughly investigated. In the present study, the effects of aerobic (DOT >= 30% air sat.), microaerobic (constant DOT = 3% air sat.) and oscillatory DOT (from 0 to 100% air sat.) conditions on pDNA production, quality and host performance were characterized. Results: Microaerobic conditions had little effect on pDNA production, supercoiled fraction and sequence fidelity. By contrast, oscillatory DOT caused a 22% decrease in pDNA production compared with aerobic cultures. Although in aerobic cultures the pDNA supercoiled fraction was 98%, it decreased to 80% under heterogeneous DOT conditions. The different oxygen availabilities had no effect on the fidelity of the produced pDNA. The estimated metabolic fluxes indicated substantial differences at the level of the pentose phosphate pathway and TCA cycle under different conditions. Cyclic changes in fermentative pathway fluxes, as well as fast shifts in the fluxes through cytochromes, were also estimated. Model-based genetic modifications that can potentially improve the process performance are suggested. Conclusions: DOT heterogeneities strongly affected cell performance, pDNA production and topology. This should be considered when operating or scaling-up a bioreactor with deficient mixing. Constant microaerobic conditions affected the bacterial metabolism but not the amount or quality of pDNA. Therefore, pDNA production in microaerobic cultures may be an alternative for bioreactor operation at higher oxygen transfer rates

Photophysical Characterization of Isoguanine in a Prebiotic-Like Environment

It is intriguing how a mixture of organic molecules survived the prebiotic UV fluxes and evolved into the actual genetic building blocks. Scientists are trying to shed light on this issue by synthesizing nucleic acid monomers and their analogues under prebiotic Era-like conditions and by exploring their excited state dynamics. To further add to this important body of knowledge, this study discloses new insights into the photophysical properties of protonated isoguanine, an isomorph of guanine, using steady-state and femtosecond broadband transient absorption spectroscopies, and quantum mechanical calculations. Protonated isoguanine decays in ultrafast time scales following 292 nm excitation, consistently with the barrierless paths connecting the bright S1 (ππ*) state with different internal conversion funnels. Complementary calculations for neutral isoguanine predict similar photophysical properties. These results demonstrate that protonated isoguanine can be considered photostable in contrast to protonated guanine, which exhibits 40-fold longer excited state lifetimesThe authors acknowledge funding from the National Science Foundation (Grant No. CHE-1800052), the Ramón y Cajal Program (Grant: RYC-2016-20489) and the Ministerio de Ciencia, Innovación y Universidades (PGC2018-094644-B-C21, PID2021- 125207NB-C31 and PRE2019-090448 projects). L. M. F. thanks the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with Universidad Autónoma de Madrid in the line Support to Young Researchers, in the context of the V PRICIT (Regional Programme of Research and Technological Innovation) (SI3/PJI/2021-00331

MANEJO FLORESTAL EMPRESARIAL NO ACRE: CUSTOS DA ATIVIDADE PRÉ-EXPLORATÓRIA NA FLORESTA ESTADUAL DO ANTIMARY.

Esta pesquisa aborda a atividade madeireira sob o regime de concessão florestal desenvolvido no Estado do Acre. Os objetivos do presente estudo são: identificar o custo da produção do manejo florestal sustentável (MFS) para produção madeireira, tendo como base a Floresta Estadual do Antimary (FEA); e, quantificar o valor, a ser pago pela terra, numa área destinada como floresta pública de produção, no ano de 2005. Para tal, foi considerada, como premissa básica, um ciclo de corte de 15 anos. As técnicas usadas identificaram o custo de produção da madeira com origem em uma florestal manejada (Cmf), o valor presente líquido (VPL) do MFS e o valor esperado da terra (VET), os quais foram calculados considerando as taxas de desconto de 4%, 6%, 8%, 10% e 12% ao ano. Os principais resultados obtidos foram: a uma taxa de desconto de 4% ao ano, uma empresa gastaria, com o manejo florestal, US$68,50/ha e geraria um VPL de US$ 92,18/ha. Por outro lado, a 12% ao ano, estes valores decresceriam para US$62,53/ha e US$ 81,34/ha, respectivamente. O preço máximo que poderia ser pago por um hectare de terra na FEA, em 2005, para que o MFS fosse remunerado numa taxa de 4% a.a., foi de US$218,17/ha, visto que, a partir de 6$ 199,03/ha).---------------------------------------------This research addresses the timber activity under a forest concession system in the State of Acre. Its objectives are: to identify the production cost related to sustainable forest management (SFM) for timber yield, having as scenario the Antimary State Forest (ASF); and, quantify the value to be paid for the land, in an area designed as public production forest, in the year 2005. So, it was recognized as basic foundation, a 15-year cutting cycle. The techniques used identified the production cost of log coming from a managed forest area (Cmf), the net present value (NPV) concerning SFM and the land expectation value (LEV), which were calculated adopting annual interest rates of 4%, 6%, 8%, 10% and 12%. The main results obtained were: at annual interest rate of 4%, a firm would spend, with forest management US$68,50/ha and would generate US$ 92,18/ha as NPV. On the another hand, at 12% a.a., these value would decrease to US$62,53/ha and US$ 81,34/ha, respectively. The maximum price which could be paid for one hectare of land in the ASF, in 2005, in order to remunerate SFM at 4% a.a., was US$218,17/ha, because adopting interest rates greater than 6$ 199,03/ha).Manejo florestal sustentável, Custo da produção madeireira, Economia florestal, Valor esperado da terra, Sustainable forest management, timber production cost, Forest economics, Land expectation value, Resource /Energy Economics and Policy,

Fatores influenciadores da intenção de doar sangue: proposição de um modelo exploratório

Purpose – Identify the main factors that significantly influence individuals living in the metropolitan region of Belo Horizonte / MG to donate blood.Design/methodology/approach – Methodologically, it was decided to develop a quantitative research, developed in the light of structural equation modeling, allowing the development of an exploratory behavioral model about the intention to donate blood.Findings – As main results, it was identified that the 'attitude towards screening' contributes significantly to the 'perception of safety' that the individual has about the process of blood donation.Research limitations/implications – Difficulty of access to the main hemotherapy center in the state, Minas Gerais Blood Bank Foundation (HEMOMINAS), a fact that prevented access to up-to-date data on the region's blood donation scenario.Practical implications – The indicators that are directly related to the practice of blood donation obtained statistically significant mean differences between the group of individuals who already donated blood and those who never donated, the former being more sensitive to calls for donation.Originality/value – There is a deepening of the knowledge of the variables that influence the individual who voluntarily performs an act such as blood donation. In this sense, this study provides inputs for the development of more assertive, efficient and effective blood donation public policies, contributing to the recovery of blood banks and raising the rate of donors in the country.Finalidade - Identificar os principais fatores que influenciam significativamente indivíduos residentes na Região Metropolitana de Belo Horizonte/MG a doarem sangueDesenho / metodologia / abordagem - Metodologicamente optou-se por desenvolver uma pesquisa quantitativa, desenvolvida à luz da modelagem de equações estruturais, permitindo que fosse desenvolvido um modelo exploratório comportamental acerca da intenção de doar sangue.Constatações - Como principais resultados identificou-se que a ‘atitude em relação à triagem’ contribui significativamente para a ‘percepção de segurança’ que o indivíduo possui acerca do processo de doação de sangue.Limitações / implicações da pesquisa - Dificuldade de acesso ao principal centro de hemoterapia do estado, a Fundação Centro de Hematologia e Hemoterapia do Estado de Minas Gerais (HEMOMINAS), fato que impediu o acesso a dados atualizados sobre o cenário de doação sanguínea da região.Implicações práticas - Os indicadores que estão diretamente relacionados à prática da doação sanguínea obtiveram diferenças de médias estatisticamente significantes entre o grupo de indivíduos que já doaram sangue e que aqueles que nunca doaram, sendo que os primeiros são mais sensíveis aos apelos em prol da doação.Originalidade / valor - Aprofundamento no conhecimento das variáveis que influenciam o indivíduo que, voluntariamente, executa um ato como a doação de sangue. Nesse sentido, este estudo fornece insumos para o desenvolvimento de políticas públicas de doação de sangue mais assertivas, eficazes e efetivas, contribuindo para a recuperação dos bancos de sangue e elevação da taxa de doadores do país

The origin of efficient triplet state population in sulfur-substituted nucleobases

Elucidating the photophysical mechanisms in sulfur-substituted nucleobases (thiobases) is essential for designing prospective drugs for photo-and chemotherapeutic applications. Although it has long been established that the phototherapeutic activity of thiobases is intimately linked to efficient intersystem crossing into reactive triplet states, the molecular factors underlying this efficiency are poorly understood. Herein we combine femtosecond transient absorption experiments with quantum chemistry and nonadiabatic dynamics simulations to investigate 2-thiocytosine as a necessary step to unravel the electronic and structural elements that lead to ultrafast and near-unity triplet-state population in thiobases in general. We show that different parts of the potential energy surfaces are stabilized to different extents via thionation, quenching the intrinsic photostability of canonical DNA and RNA nucleobases. These findings satisfactorily explain why thiobases exhibit the fastest intersystem crossing lifetimes measured to date among bio-organic molecules and have near-unity triplet yields, whereas the triplet yields of canonical nucleobases are nearly zeroS.M., P.M. and L.G. thank the Austrian Science Fund (FWF) through project P25827, the COST action CM1204 (XLIC) and the Vienna Scientific Cluster (VSC) for the allocation of computational time. We also thank F. Plasser for assistance with the TheoDORE program. I.C. and L.M.-F. thank the Comunidad Autónoma de Madrid, the Ministerio de Economía y Competitividad (Spain) for an FPU (L.M.-F.) grant, the Projects FOTOCARBON-CM S2013/MIT-2841 and No. CTQ2015-63997-C2, and the ERA-Chemistry Project PIM2010EEC-00751 for financial support, as well as the Centro de Computación Científica UAM for generous allocation of computational time. M.P., N.D. and C.E.C.-H. acknowledge the CAREER program of the National Science Foundation (Grant No. CHE-1255084) for financial suppor