1,745 research outputs found
Sleptons without Hadrons
Multilepton searches for electroweakino and slepton pair production at hadron
colliders remain some of the best means to test weak-scale supersymmetry.
Searches at the CERN Large Hadron Collider, however, are limited by large
diboson and top quark pair backgrounds, despite the application of traditional,
central jet vetoes. In this context, we report the impact of introducing
dynamic jet vetoes in searches for colorless superpartners. As a representative
scenario, we consider the Drell-Yan production of a pair of right-handed smuons
decaying into a dimuon system accompanied with missing transverse energy. As an
exploratory step, we consider several global and local measures of the leptonic
and hadronic activity to construct the veto. In most all cases, we find that
employing a dynamic jet veto improves the sensitivity, independently of the
integrated luminosity. The inclusion of non-perturbative multiple particle
interactions and next-to-leading order jet merging does not alter this picture.
Directions for further improvements are discussed.Comment: 18 pages; 7 figures; additional discussions added; journal version;
results unchange
Bromostibine complexes of iron(II): hypervalency and reactivity
The halostibine complexes [CpFe(CO)2(SbMe2Br)][CF3SO3] and [CpFe(CO)2(SbMe2Br)][BF4] both contain significant interactions between the anion and the formally neutral Sb(III) ligand, which simultaneously displays Lewis acidic and Lewis basic properties. The unexpected secondary product [CpFe(CO)(Me2BrSb-?-Br-SbBrMe2)] is formed in the presence of excess ligand, the strongly associated Br– anion bridging the two Sb donors to form a four-membered FeSb2Br ring.<br/
RNA-seq reveals post-transcriptional regulation of Drosophila insulin-like peptide dilp8 and the neuropeptide-like precursor Nplp2 by the exoribonuclease Pacman/XRN1
Ribonucleases are critically important in many cellular and developmental processes and defects in their expression are associated with human disease. Pacman/XRN1 is a highly conserved cytoplasmic exoribonuclease which degrades RNAs in a 5' - 3' direction. In Drosophila, null mutations in pacman result in small imaginal discs, a delay in onset of pupariation and lethality during the early pupal stage. In this paper, we have used RNA-seq in a genome-wide search for mRNAs misregulated in pacman null wing imaginal discs. Only 4.2% of genes are misregulated ±>2-fold in pacman null mutants compared to controls, in line with previous work showing that Pacman has specificity for particular mRNAs. Further analysis of the most upregulated mRNAs showed that Pacman post-transcriptionally regulates the expression of the secreted insulin-like peptide Dilp8. Dilp8 is related to human IGF-1, and has been shown to co-ordinate tissue growth with developmental timing in Drosophila. The increased expression of Dilp8 is consistent with the developmental delay seen in pacman null mutants. Our analysis, together with our previous results, show that the normal role of this exoribonuclease in imaginal discs is to suppress the expression of transcripts that are crucial in apoptosis and growth control during normal development
Activity-based life-cycle costing applied to an innovative forestry company product portfolio
An accounting system helps to provide information for planning and control of production. This article presents a Life Cycle Costing by using an Activity Based Costing approach of an innovative forestry company. In order to perform a cradle-to-gate assessment the study covers the forest and industrial activities of the forest product processing. The costs of each product in the portfolio are determined by the treatment activities they undergo. The inventory covers several years of activity of the company, which makes it possible to calculate the uncertainty of the average results with Monte Carlo simulation presented in the result section. Based on the results a products portfolio analysis was performed to identify the development progress phases of the mains products to support the product rollover strategy decision
Identification of presumed pathogenic KRT3 and KRT12 gene mutations associated with Meesmann corneal dystrophy.
PurposeTo report potentially pathogenic mutations in the keratin 3 (KRT3) and keratin 12 (KRT12) genes in two individuals with clinically diagnosed Meesmann corneal dystrophy (MECD).MethodsSlit-lamp examination was performed on the probands and available family members to identify characteristic features of MECD. After informed consent was obtained, saliva samples were obtained as a source of genomic DNA, and screening of KRT3 and KRT12 was performed. Potentially pathogenic variants were screened for in 200 control chromosomes. PolyPhen-2, SIFT, and PANTHER were used to predict the functional impact of identified variants. Short tandem repeat genotyping was performed to confirm paternity.ResultsSlit-lamp examination of the first proband demonstrated bilateral, diffusely distributed, clear epithelial microcysts, consistent with MECD. Screening of KRT3 revealed a heterozygous missense variant in exon 1, c.250C>T (p.(Arg84Trp)), which has a minor allele frequency of 0.0076 and was not identified in 200 control chromosomes. In silico analysis with PolyPhen-2 and PANTHER predicted the variant to be damaging to protein function; however, SIFT analysis predicted tolerance of the variant. The second proband demonstrated bilateral, diffusely distributed epithelial opacities that appeared gray-white on direct illumination and translucent on retroillumination. Neither parent demonstrated corneal opacities. Screening of KRT12 revealed a novel heterozygous insertion/deletion variant in exon 6, c.1288_1293delinsAGCCCT (p.(Arg430_Arg431delinsSerPro)). This variant was not present in either of the proband's parents or in 200 control chromosomes and was predicted to be damaging by PolyPhen-2, PANTHER, and SIFT. Haplotype analysis confirmed paternity of the second proband, indicating that the variant arose de novo.ConclusionsWe present a novel KRT12 mutation, representing the first de novo mutation and the first indel in KRT12 associated with MECD. In addition, we report a variant of uncertain significance in KRT3 in an individual with MECD. Although the potential pathogenicity of this variant is unknown, it is the first variant affecting the head domain of K3 to be reported in an individual with MECD and suggests that disease-causing variants associated with MECD may not be restricted to primary sequence alterations of either the helix-initiation or helix-termination motifs of K3 and K12
Circulating microRNA biomarkers in melanoma: tools and challenges in personalised medicine
Effective management of melanoma depends heavily on early diagnosis. When detected in early non-metastatic stages, melanoma is almost 100% curable by surgical resection, however when detected in late metastatic stages III and IV, 5-year survival rates drop to ~50% and 10–25%, respectively, due to limited efficacy of current treatment options. This presents a pressing need to identify biomarkers that can detect patients at high risk of recurrence and progression to metastatic disease, which will allow for early intervention and survival benefit. Accumulating evidence over the past few decades has highlighted the potential use of circulating molecular biomarkers for melanoma diagnosis and prognosis, including lactate dehydrogenase (LDH), S100 calcium-binding protein B (S100B) and circulating tumor DNA (ctDNA) fragments. Since 2010, circulating microRNAs (miRNAs) have been increasingly recognised as more robust non-invasive biomarkers for melanoma due to their structural stability under the harsh conditions of the blood and different conditions of sample processing and isolation. Several pre-analytical and analytical variables challenge the accurate quantification of relative miRNA levels between serum samples or plasma samples, leading to conflicting findings between studies on circulating miRNA biomarkers for melanoma. In this review, we provide a critical summary of the circulating miRNA biomarkers for melanoma published to date
Concerns about medication and medication adherence in patients with chronic pain recruited from general practice
This study examines the concerns and beliefs about medication reported by patients with nonmalignant chronic pain encountered within general practice. Two hundred thirty-nine patients with chronic pain took part in this research. Patients completed the Pain Medication Attitudes Questionnaire, a measure of patient concerns and beliefs relating to addiction, withdrawal, side effects, mistrust in doctors, perceived need of medication, scrutiny from others, and tolerance. The data revealed that patient concerns and beliefs predicted general medication nonadherence. In addition, concerns were related to the direction of nonadherence: overuse of medication was related to increased perceived need for medication and greater concern over side effects; underuse was related to decreased concerns over withdrawal and increased mistrust in the prescribing doctor. Analyses also indicated that patient attitudes and concerns about medication were more predictive of nonadherence than both level of pain and the reported frequency of experienced side effects. This research contributes to the increasing evidence that patient attitudes and beliefs about pain medication are associated with adherence behavior. Training general practitioners to identify and address these concerns may reduce concerns, improve adherence, and facilitate the doctor-patient relationship
[Pd4(μ3-SbMe3)4(SbMe3)4]: A Pd(0) tetrahedron with μ3-bridging trimethylantimony ligands
The palladium(II) chlorostibine complex [PdCl2(SbMe2Cl)2]2 has a dimeric structure in the solid state, stabilized by hyper-coordination at the Lewis amphoteric Sb centers. Reaction with 8 equiv of MeLi forms [Pd4(μ3-SbMe3)4(SbMe3)4], whose structure comprises a tetrahedral Pd(0) core with four terminal SbMe3 ligands and four μ3-SbMe3 ligands, one capping each triangular Pd3 face. Density functional theory calculations, supported by energy decomposition analysis and the natural orbitals for chemical valence scheme, highlight significant donor and acceptor orbital contributions to the bonding between both the terminal and the bridging SbMe3 ligands and the Pd4 core
Specialization of the Drosophila nuclear export family protein Nxf3 for piRNA precursor export.
The PIWI-interacting RNA (piRNA) pathway is a conserved small RNA-based immune system that protects animal germ cell genomes from the harmful effects of transposon mobilization. In Drosophila ovaries, most piRNAs originate from dual-strand clusters, which generate piRNAs from both genomic strands. Dual-strand clusters use noncanonical transcription mechanisms. Although transcribed by RNA polymerase II, cluster transcripts lack splicing signatures and poly(A) tails. mRNA processing is important for general mRNA export mediated by nuclear export factor 1 (Nxf1). Although UAP56, a component of the transcription and export complex, has been implicated in piRNA precursor export, it remains unknown how dual-strand cluster transcripts are specifically targeted for piRNA biogenesis by export from the nucleus to cytoplasmic processing centers. Here we report that dual-strand cluster transcript export requires CG13741/Bootlegger and the Drosophila nuclear export factor family protein Nxf3. Bootlegger is specifically recruited to piRNA clusters and in turn brings Nxf3. We found that Nxf3 specifically binds to piRNA precursors and is essential for their export to piRNA biogenesis sites, a process that is critical for germline transposon silencing. Our data shed light on how dual-strand clusters compensate for a lack of canonical features of mature mRNAs to be specifically exported via Nxf3, ensuring proper piRNA production
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