Non-perturbative time-dependent String Backgrounds and Axion-induced Optical Activity

Conformal invariance for bosonic strings in time-dependent backgrounds of graviton, dilaton and Kalb-Ramond field is obtained by imposing Weyl-beta functions to be homogeneous in time, to all orders in $\alpha^{'}$. This construction is possible in any target space dimension, as a result of the non-trivial background configurations. The electromagnetic effects of the antisymmetric tensor field, when coupled to an Abelian (electromagnetic) gauge field, are discussed in the framework of a four-dimensional Minkowski Universe, for concreteness. Non-trivial optical activity is demonstrated, which constitutes a way of detecting string-inspired axion/dilaton effects in such models.Comment: 12 page

Investigation of Post-Consumer Regrind Content in Polyethylene and Polypropylene for Consumer Packaging Applications

With the rise of plastics products in waste streams, both consumer products companies and consumers are looking for greener methods to produce the same products with less of a carbon footprint. One way of achieving these goals is to include recycled plastic into consumer goods. These recycled greener alternatives provide many of the same benefits of virgin plastic material. The goal of this project was to determine what, if any, differences are there between virgin resins and resins that contain post-consumer recycled content (PCR). Control and experimental resins were obtained and injection molded to create samples for analysis. Control resins were Ineos H05A-00 Polypropylene Homopolymer and Marlex 9012 High-Density Polyethylene. Experimental resins included Plastic Bank SDS clear polypropylene (Social Plastic), KWR-621 Post Consumer Recycled FDA Polypropylene Resin, and KW Post-Consumer Recycled Polyethylene Resins: KWR 102 BM High-Density Polyethylene and KWR 101 150 Natural High-Density Polyethylene. Samples underwent thermal testing by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to determine key thermal transition and material degradation temperatures to compare each of the experimental materials to the virgin resins. Mechanical testing included tensile testing and Izod impact testing to determine the mechanical strength of each experimental materials to compare to the virgin resins. Melt flow was performed to determine the rheological properties of the virgin and post-consumer recycled (PCR) resins in the melt

Antisymmetric-Tensor and Electromagnetic effects in an alpha'-non-perturbative Four-Dimensional String Cosmology

Starting from an exact (in the Regge slope alpha') functional method for a bosonic stringy sigma-model, we investigate four-dimensional cosmological string solutions in graviton, dilaton and antisymmetric tensor backgrounds, compatible with world-sheet conformal invariance, and valid beyond perturbative expansions in powers of alpha'. The antisymmetric tensor field, playing the role of an axion in the four-dimensional target space time, leads to spatial anisotropies of the emergent Robertson-Walker expanding Universe, and, upon coupling the system to the electromagnetic field, it results in non-trivial optical activity. Some estimates of the corresponding effects are made and their relevance to current cosmology is briefly discussed

Synchronous primary colorectal and liver metastasis: impact of operative approach on clinical outcomes and hospital charges

AbstractObjectivesThe management of patients with colorectal cancer (CRC) and synchronous colorectal liver metastasis (CLM) remains controversial. The present study was conducted in order to assess the clinical and economic impacts of managing synchronous CLM with a staged versus a simultaneous surgery approach.MethodsA total of 224 patients treated for synchronous CLM during 1990–2012 were identified in the Johns Hopkins Hospital liver database. Data on clinicopathological features, perioperative outcomes and total hospital charges (inflation-adjusted) were collected and analysed.ResultsOverall, 113 (50.4%) patients underwent staged surgery and 111 (49.6%) were submitted to a simultaneous CRC and liver operation. At surgery, liver-directed therapy included hepatectomy (75.0%) or combined resection and ablation (25.0%). Perioperative morbidity (30.0%) and mortality (1.3%) did not differ between groups (both P > 0.05). Median total length of hospitalization was longer in the staged (13 days) than the simultaneous (7 days) surgery group (P < 0.001). Median total hospital charges were higher among patients undergoing staged surgery (US$61 938) than among those undergoing a simultaneous operation (US$34 114) (P < 0.01). Median (simultaneous, 32.4 months versus staged, 39.6 months; P = 0.65) and 5-year (simultaneous, 27% versus staged, 29%; P = 0.60) overall survival were similar between groups.ConclusionsPatients with synchronous CLM managed with either simultaneous or staged surgery have comparable perioperative and longterm outcomes. However, patients treated with simultaneous surgery spent an average of 6 days fewer in hospital, resulting in a reduction of median hospital charges of US$27 824 (55.1%). When appropriate and technically feasible, the simultaneous surgery approach to synchronous CLM should be preferred

Black Box Spring 2022/2023

The Black Box is a creative publication dedicated to displaying the talented work of the Embry-Riddle Prescott community - endless creativity and ingenuity flow throughout the Prescott area and our goal is to display it

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery