Stochastic Variational Search for ΛΛ4^{4}_{\Lambda\Lambda}H

A four-body calculation of the $pn\Lambda\Lambda$ bound state, $^{\ 4}_{\Lambda\Lambda}$H, is performed using the stochastic variational method and phenomenological potentials. The$NN$,$\Lambda N$, and$\Lambda\Lambda$potentials are taken from a recent Letter by Filikhin and Gal, PRL{\bf 89}, 172502 (2002). Although their Faddeev-Yakubovsky calculation found no bound-state solution over a wide range of$\Lambda\Lambda$interaction strengths, the present variational calculation gives a bound-state energy, which is clearly lower than the$_\Lambda^3{H}+\Lambda$threshold, even for a weak$\Lambda\Lambda$interaction strength deduced from a recent experimental$B_{\Lambda\Lambda}(^{6}_{\Lambda\Lambda}{He})$value. The binding energies obtained are close to, and slightly larger than, the values obtained from the three-body$d\Lambda\Lambda$ model in the Letter.Comment: Corrected typos, added addtional calculations regarding a truncated to l=0 interaction model, 4 pages, 3 figure

Radiation Transport and Shielding for Space Exploration and High Speed Flight Transportation

Transportation of ions and neutrons in matter is of direct interest in several technologically important and scientific areas, including space radiation, cosmic ray propagation studies in galactic medium, nuclear power plants and radiological effects that impact industrial and public health. For the proper assessment of radiation exposure, both reliable transport codes and accurate data are needed. Nuclear cross section data is one of the essential inputs into the transport codes. In order to obtain an accurate parametrization of cross section data, theoretical input is indispensable especially for processes where there is little or no experimental data available. In this grant period work has been done on the studies of the use of relativistic equations and their one-body limits. The results will be useful in choosing appropriate effective one-body equation for reaction calculations. Work has also been done to improve upon the data base needed for the transport codes used in the studies of radiation transport and shielding for space exploration and high speed flight transportation. A phenomenological model was developed for the total absorption cross sections valid for any system of charged and/or uncharged collision pairs for the entire energy range. The success of the model is gratifying. It is being used by other federal agencies, national labs and universities. A list of publications based on the work during the grant period is given below and copies are enclosed with this report

Gray-level co-occurrence matrix bone fracture detection

Problem statement: Currently doctors in orthopedic wards inspect the bone x-ray images according to their experience and knowledge in bone fracture analysis. Manual examination of x-rays has multitude drawbacks. The process is time-consuming and subjective. Approach: Since detection of fractures is an important orthopedics and radiologic problem and therefore a Computer Aided Detection(CAD) system should be developed to improve the scenario. In this study, a fracture detection CAD based on GLCM recognition could improve the current manual inspection of x-ray images system. The GLCM for fracture and non-fracture bone is computed and analysis is made. Features of Homogeneity, contrast, energy, correlation are calculated to classify the fractured bone. Results: 30 images of femur fractures have been tested, the result shows that the CAD system can differentiate the x-ray bone into fractured and nonfractured femur. The accuracy obtained from the system is 86.67. Conclusion: The CAD system is proved to be effective in classifying the digital radiograph of bone fracture. However the accuracy rate is not perfect, the performance of this system can be further improved using multiple features of GLCM and future works can be done on classifying the bone into different degree of fracture specifically

Control Management and Business Performances: the Malaysian Family SMEs Perspectives

This study examined the relationship between control management and family business performance in the Malaysian context. It has two objectives, the first being to determine the relationship of organizational credit control policy and procedures, employee development and motivation, and intelligence collection systems to subsequent collection reports in Malaysian family SMEs. The second objective is to investigate the moderating effect of participation in decision-making and work effort towards innovation and business performance. This is a descriptive study involving 90 senior executives employed in 90 Malaysian family SMEs/firms. A correlation analysis from this study confirmed previous researchers’ observations that high-level organizational commitment to credit control management is linked to improvements in business performance. The results suggest that three components – credit policy, employee development, and intelligence collection systems – are the most important predictors for the efficiency and effectiveness of credit control management.   &nbsp

Hyperonic mixing in five-baryon double-strangeness hypernuclei in a two-channel treatment

Properties of hypernuclei $_{\Lambda \Lambda}^5$H and $_{\Lambda \Lambda }^5$He are studied in a two-channel approach with explicit treatment of coupling of channels ^3\text{Z}+\Lambda+\Lambda and \alpha+\Xi. Diagonal \Lambda\Lambda and coupling \Lambda\Lambda-\Xi N interactions are derived within G-matrix procedure from Nijmegen meson-exchange models. Bond energy \Delta B_{\Lambda\Lambda} in $_{\Lambda \Lambda}^5$He exceeds significantly that in $_{\Lambda \Lambda}^5$H due to the channel coupling. Diagonal \Xi\alpha attraction amplifies the effect, which is sensitive also to \Lambda-core interaction. The difference of the \Delta B_{\Lambda\Lambda} values can be an unambiguous signature of the \Lambda\Lambda-\Xi N coupling in \Lambda\Lambda hypernuclei. However, improved knowledge of the hyperon-nucleus potentials is needed for quantitative extraction of the coupling strength from future data on the \Lambda\Lambda hypernuclear binding energies.Comment: 11 pages with 3 figures; Phys. Rev. C, accepte

Relativistic Multiple Scattering Theory and the Relativistic Impulse Approximation

It is shown that a relativistic multiple scattering theory for hadron-nucleus scattering can be consistently formulated in four-dimensions in the context of meson exchange. We give a multiple scattering series for the optical potential and discuss the differences between the relativistic and non-relativistic versions. We develop the relativistic multiple scattering series by separating out the one boson exchange term from the rest of the Feynman series. However this particular separation is not absolutely necessary and we discuss how to include other terms. We then show how to make a three-dimensional reduction for hadron-nucleus scattering calculations and we find that the relative energy prescription used in the elastic scattering equation should be consistent with the one used in the free two-body t-matrix involved in the optical potential. We also discuss what assumptions are involved in making a Dirac Relativistic Impulse Approximation (RIA).Comment: 20 pages, 9 figures, Accepted for publication in Journal of Physics

A comparison of existing risk prediction models in patients undergoing venoarterial extracorporeal membrane oxygenation

© 2020 The Author(s) Background: Patients undergoing consideration for venoarterial extracorporeal membrane oxygenation (VA-ECMO) require an immediate risk profile assessment in the setting of incomplete information. A number of survival prediction models for critically ill patients and patients undergoing elective cardiac surgery or institution of VA-ECMO support have been designed. We assess the ability of these models to predict outcomes in a cohort of patients undergoing institution of VA-ECMO for cardiogenic shock or cardiac arrest. Methods: Fifty-one patients undergoing institution of VA-ECMO support were retrospectively analyzed. APACHE II, SOFA, SAPS II, Encourage, SAVE, and ACEF scores were calculated. Their ability to predict outcomes were assessed. Results: Indications for ECMO support included postcardiotomy shock (25%), ischemic etiologies (39%), and other etiologies (36%). Pre-ECMO arrest occurred in 73% and 41% of patients underwent cannulation during arrest. Survival to discharge was 39%. Three survival prediction model scores were significantly higher in nonsurvivors to discharge than surivors; the Encourage score (25.4 vs 20; p =.04), the APACHE II score (23.6 vs 19.2; p =.05), and the ACEF score (3.1 vs 1.8; p =.03). In ROC analysis, the ACEF score demonstrated the greatest predictive ability with an AUC of 0.7. Conclusions: A variety of survival prediction model scores designed for critically ill ICU and VA-ECMO patients demonstrated modest discriminatory ability in the current cohort of patients. The ACEF score, while not designed to predict survival in critically ill patients, demonstrated the best discriminatory ability. Furthermore, it is the simplest to calculate, an advantage in the emergent setting

Peripheral blood mononuclear cells of breast cancer patients can be reprogrammed to enhance anti-HER-2/neu reactivity and overcome myeloid-derived suppressor cells [poster abstract]

Barriers limiting the efficacy of adoptive cellular therapy (ACT) for breast cancer patients include immune suppression mediated by myeloid-derived suppressor cells (MDSC) and a low frequency of tumor-reactive memory T cells (Tm). Recently, we developed an ex vivo protocol to reprogram tumor-reactive murine splenocytes; these cells were found to be resistant to MDSC suppression and protected FVBN202 mice from tumor challenge. Here, we evaluated the clinical applicability of reprogramming tumor-sensitized PBMCs isolated from patients with early stage breast cancer by treatment with bryostatin 1 and ionomycin (B/I) combined with IL-2, IL-7 and IL-15. Our data demonstrate that reprogrammed cells are enriched with Tm cells (n=5; p=0.006), as well as activated CD56+(n=6; p=0.003) and CD161+ (n=4; p=0.02) NKT cells, and demonstrate expansion in total cell numbers (n=16; p=0.003) compared to baseline cells. Reprogrammed PBMCs displayed enhanced HER-2/neu-specific IFN-γ producing immune responses (n=6; p=0.04); non-reprogrammed control PBMC IFN-γ production was not significant (n=6; p=0.4). Furthermore, high-throughput sequencing analysis of the T cell receptor (TcR) Vβ in one patient demonstrated clonal expansion of specific TcR VJ recombination events resulting from cellular reprogramming, suggestive of an enriched frequency of specific tumor antigen-primed T cell clones. Interestingly, reprogrammed T cells were resistant to autologous CD33+ CD11b+ HLA-DRlo/- MDSCs, as determined by further enhanced HER-2/neu-specific IFN-γ secretion in the presence of MDSCs (n=6; p=0.03). Activated CD161+ NKT cells comprising 3% or greater of total reprogrammed cells rendered T cells resistant to MDSCs (n=3; p=0.02). Upregulation of NKG2D expression on CD161+(n=5; p=0.0006) and CD56+ (n=5; p=0.04) NKT cells resulted from cellular reprogramming. Therefore, NKG2D signaling was blocked using anti-NKG2D blocking antibody in our co-culture system, resulting in the abrogation of resistance to MDSCs as determined by blunted IFN-γ secretion (n=3; p=0.04). Finally, the phenotype of MDSCs after co-culture with reprogrammed PBMC was examined; we observed downregulation of CD11b expression (n=3; p=0.02) concomitant with HLA-DR upregulation on MDSCs (n=3; p=0.001); suggestive of induced maturation of MDSCs into Dendritic Cells (DC). The results of our study offer the following strategies to improve ACT of breast cancer: i) inclusion of activated NKT cells in ACT to overcome MDSC suppression by inducing MDSC maturation into DCs, and ii) PBMC reprogramming to enrich the frequency of tumor-reactive Tm cells

Chromatic acclimation and population dynamics of green sulfur bacteria grown with spectrally tailored light

Living organisms have to adjust to their surrounding in order to survive in stressful conditions. We study this mechanism in one of most primitive creatures – photosynthetic green sulfur bacteria. These bacteria absorb photons very efficiently using the chlorosome antenna complexes and perform photosynthesis in extreme low-light environments. How the chlorosomes in green sulfur bacteria are acclimated to the stressful light conditions, for instance, if the spectrum of light is not optimal for absorption, is unknown. Studying Chlorobaculum tepidum cultures with far-red to near-infrared light-emitting diodes, we found that these bacteria react to changes in energy flow by regulating the amount of light-absorbing pigments and the size of the chlorosomes. Surprisingly, our results indicate that the bacteria can survive in near-infrared lights capturing low-frequency photons by the intermediate units of the light-harvesting complex. The latter strategy may be used by the species recently found near hydrothermal vents in the Pacific Ocean