Tripled yield in direct-drive laser fusion through statistical modelling.

Focusing laser light onto a very small target can produce the conditions for laboratory-scale nuclear fusion of hydrogen isotopes. The lack of accurate predictive models, which are essential for the design of high-performance laser-fusion experiments, is a major obstacle to achieving thermonuclear ignition. Here we report a statistical approach that was used to design and quantitatively predict the results of implosions of solid deuterium-tritium targets carried out with the 30-kilojoule OMEGA laser system, leading to tripling of the fusion yield to its highest value so far for direct-drive laser fusion. When scaled to the laser energies of the National Ignition Facility (1.9 megajoules), these targets are predicted to produce a fusion energy output of about 500 kilojoules-several times larger than the fusion yields currently achieved at that facility. This approach could guide the exploration of the vast parameter space of thermonuclear ignition conditions and enhance our understanding of laser-fusion physics.

Environmental life cycle assessment of production of the high intensity sweetener steviol glycosides from Stevia rebaudiana leaf grown in Europe: The SWEET project.

Purpose: There is an increasing interest in the use of non-nutritive sweeteners to replace added sugar in food and beverage products for reasons of improving consumer health. Much work has been done to understand safety of sweeteners, but very little on sustainability. To address that gap, this study presents the results of a life cycle assessment (LCA) of production of rebaudioside A 60%, 95% pure (RA60) steviol glycoside mix from Stevia rebaudiana leaf grown in Europe. Methods: An attributional cradle-to-factory-gate life cycle assessment was conducted on growing of stevia leaves and extraction of steviol glycosides in Europe. Primary data were used from a case study supply chain. Results are reported in impact categories from the ReCiPe 2016 (H) method, with focus given to global warming potential, freshwater eutrophication, water consumption, and land use. Impacts are expressed both in terms of production mass and sweetness equivalence, a common metric for understanding high intensity sweetener potency. Sweetness equivalence of RA60 is typically 200 to 300 times that of sugar. Comparison of environmental impact is made to sugar (sucrose) produced from both cane and beets. The research is part of the EU project SWEET (sweeteners and sweetness enhancers: impact on health, obesity, safety, and sustainability). Results and discussion: Global warming potential for production of RA60 was found to be 20.25 kgCO2-eq/kgRA60 on a mass basis and 0.081 kgCO2-eq/kgSE on a sweetness equivalence basis. Field production of stevia leaves was found to be the main source of impact for most impact categories, and for all four focus categories. Extraction of the RA60 was the main source of impact for the others. Leaf processing and seedling propagation were minor contributors to life cycle impact. Removal of international transport from the supply chain reduced global warming potential by 18.8%. Compared with sugar on a sweetness equivalence basis, RA60 has approximately 5.7% to 10.2% the impact for global warming potential, 5.6% to 7.2% the impact for land use, and is lower across most other impact categories. Conclusion: This is the first LCA of steviol glycoside mix RA60 produced from leaf in Europe. The results indicate that RA60 can be used to reduce environmental impact of providing a sweet taste by replacing sugar across all impact categories. However, it is important to note that specific formulations in which RA60 is used will have a bearing on the final environmental impact of any food or beverage products. For solid foods, this requires further research. Supplementary Information: The online version contains supplementary material available at 10.1007/s11367-022-02127-9.

Direct-drive laser fusion: status, plans and future.

Laser-direct drive (LDD), along with laser indirect (X-ray) drive (LID) and magnetic drive with pulsed power, is one of the three viable inertial confinement fusion approaches to achieving fusion ignition and gain in the laboratory. The LDD programme is primarily being executed at both the Omega Laser Facility at the Laboratory for Laser Energetics and at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. LDD research at Omega includes cryogenic implosions, fundamental physics including material properties, hydrodynamics and laser-plasma interaction physics. LDD research on the NIF is focused on energy coupling and laser-plasma interactions physics at ignition-scale plasmas. Limited implosions on the NIF in the 'polar-drive' configuration, where the irradiation geometry is configured for LID, are also a feature of LDD research. The ability to conduct research over a large range of energy, power and scale size using both Omega and the NIF is a major positive aspect of LDD research that reduces the risk in scaling from OMEGA to megajoule-class lasers. The paper will summarize the present status of LDD research and plans for the future with the goal of ultimately achieving a burning plasma in the laboratory. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

Novel Hot-Spot Ignition Designs for Inertial Confinement Fusion with Liquid-Deuterium-Tritium Spheres.

A new class of ignition designs is proposed for inertial confinement fusion experiments. These designs are based on the hot-spot ignition approach, but instead of a conventional target that is comprised of a spherical shell with a thin frozen deuterium-tritium (DT) layer, a liquid DT sphere inside a wetted-foam shell is used, and the lower-density central region and higher-density shell are created dynamically by appropriately shaping the laser pulse. These offer several advantages, including simplicity in target production (suitable for mass production for inertial fusion energy), absence of the fill tube (leading to a more-symmetric implosion), and lower sensitivity to both laser imprint and physics uncertainty in shock interaction with the ice-vapor interface. The design evolution starts by launching an ∼1-Mbar shock into a DT sphere. After bouncing from the center, the reflected shock reaches the outer surface of the sphere and the shocked material starts to expand outward. Supporting ablation pressure ultimately stops such expansion and subsequently launches a shock toward the target center, compressing the ablator and fuel, and forming a shell. The shell is then accelerated and fuel is compressed by appropriately shaping the drive laser pulse, forming a hot spot using the conventional or shock ignition approaches. This Letter demonstrates the feasibility of the new concept using hydrodynamic simulations and discusses the advantages and disadvantages of the concept compared with more-traditional inertial confinement fusion designs.

Optical characterization of the on-target OMEGA focal spot at high energy using the full-beam in-tank diagnostic.

The full-beam in-tank (FBIT) diagnostic has been deployed to directly measure the target-plane beam fluence profile, when operated at high energy, of the OMEGA Laser System at the University of Rochester's Laboratory for Laser Energetics. This paper presents the results of early measurements taken with this diagnostic and discusses an improvement that has overcome performance limitations discovered during the initial testing. The diagnostic gives new insight into the ability of the OMEGA Laser System to provide uniform fluence profiles that are consistent across all 60 beams in the laser. The ultimate goal of the FBIT diagnostic is to allow accurate assessment of the fluence uniformity on a spherical target in 60-beam implosion experiments.

The effect of hydrocortisone and x-irradiation on the lymphocytosis induced by Bordetella pertussis.

1. In mice rendered lymphocytopenic by X-irradiation or hydrocortisone acetate, pertussis vaccine evoked both lymphocytosis and polymorphonuclear leukocytosis. 2. When mice with lymphocytosis induced by pertussis vaccine were X-irradiated, prompt and extensive destruction of circulating as well as tissue small lymphocytes occurred. The devitalized circulating cells were cleared from the blood primarily by the Kupffer's cells of the hepatic sinusoids. 3. Hydrocortisone acetate administered to mice with lymphocytosis did not cause acute lymphopenia nor was there any evidence of destruction of circulating small lymphocytes. However, destruction of these cells within lymphoid tissues was apparent. These observations suggested that adrenal cortical hormones are not "lymphocytolytic" with respect to circulating lymphocytes.

Mouse thymic virus (MTLV). A mammalian herpesvirus cytolytic for CD4+ (L3T4+) T lymphocytes.

Mouse thymic virus (MTLV; ICTV designation murid herpesvirus 3) infects developing T lymphocytes of neonatal mice, causing thymic necrosis and acute immunosuppression. Infected animals shed virus indefinitely. In the present report, two-color flow cytometric analysis of T lymphocyte subpopulations defined by the markers CD4 (L3T4) and CD8 (Lyt-2) was used to determine whether MTLV was lytic for a specific thymocyte population. At peak necrosis (8-11 d after infection), numbers of CD4+8+ cells in the thymus were reduced by 80% or more as compared with controls, and CD4+8- cells were reduced by greater than 98%. The major survivors were CD4-8+ and CD4-8- lymphocytes. These data indicate that the CD4 bearing lymphocyte is a primary target for cytolysis during MTLV infection. Possible parallels between MTLV and a newly described lymphotropic human herpesvirus, human herpesvirus 6 (HHV-6/HBLV), are also suggested.

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes. IV. Generation, characterization, and specificity of cytotoxic lymphocytes.

Cytotoxic effector lymphocytes were induced in cultures of mouse spleen or lymph node cells by lymphocytosis promoting factor (LPF). The LPF-activated cytotoxic cells: (a) were not generated unless proliferation occurred; (b) sedimented in the lighter density fraction of a bovine serum albumin gradient; (c) were large, blast-like cells; and (d) were lysed by Thy-1.2 antiserum plus complement and, therefore, were T cells. Neither LPF alone nor supernates from stimulated cultures were cytotoxic. Unlike the situation with concanavalin A and phytohemagglutinin P, LPF-stimulated cytotoxic effector lymphocytes required no further addition of mitogen for maximal cytotoxicity. The effector cells displayed specificity, destroying only allogeneic but not syngeneic normal cells; in the case of tumor cells, both allogeneic and syngeneic cells werelysed in the absence of added mitogen. The reason for differentiated cytotoxicity toward syngeneic tumor and normal cells is not clear but may have some relevance to in vivo tumor rejection initiated by Bordetella pertussis.

In vivo transmission of drug resistance factors between strains of Staphylococcus aureus.

1. Multiply resistant strains of Staphylococcus aureus often harbor one or more extrachromosomal drug resistant factors as well as temperate prophages capable of mediating generalized transduction. 2. Spontaneous transduction occurs in mixed cultures of such staphylococcal strains, and the extrachromosomal resistance factors are involved more frequently than are chromosomal genes. 3. Spontaneous transduction of extrachromosomal determinants of erythromycin resistance and of linked penicillin-erythromycin resistance occurs in the kidneys of mice in which mixed infection has been induced.

Studies on the leukocytosis and lymphocytosis induced by Bordetella pertussis. I. Radioautographic analysis of the circulating cells in mice undergoing pertussis-induced hyperleukocytosis.

By the use of radioautographic techniques it was shown that the lymphocytosis induced by Bordetella pertussis in mice was not caused by an increased production of lymphocytes but was primarily due to the entry into the circulation of mature cells from tissue pools. The accompanying polymorphonuclear leukocytosis was due to both proliferation of myeloid elements and entry of mature cells from tissue reserves, with the former the predominant mechanism.

Studies on the leukocytosis and lymphocytosis induced by Bordetella pertussis. II. The effect of pertussis vaccine on the thoracic duct lymph and lymphocytes of mice.

The 24 hr volume flow, cell concentration, and total cell output of thoracic duct fluid from mice with pertussis-induced hyperlymphocytosis were markedly reduced when compared with values obtained in normal animals. An increase in the number of circulating lymphocytes occurred in several of the pertussis-treated mice despite the presence of an indwelling thoracic duct cannula. The drainage from such animals also showed a reduced cell concentration and total cell output. It is suggested that lymphocyte recirculation may be minimal in pertussis-induced lymphocytosis, and the evidence obtained also suggests that lymphocytes may enter the blood stream by direct routes during the course of the reaction.

The occurrence and properties of leukocytosis and lymphocytosis-stimulating material in the supernatant fluids of Bordetella pertussis cultures.

1. Leukocytosis- and lymphocytosis-stimulating activity was present in fluid cultures of B. pertussis. The activity was found primarily in the culture supernatant fluid. 2. The sequential changes in the leukocyte response were similar to those previously observed following injection of intact bacteria into mice. 3. Activity was destroyed by heat and was diminished, but not abolished, by prolonged treatment with proteolytic enzymes. 4. A water-insoluble fraction of the culture supernatant fluid was isolated which contained virtually all of the activity. The specific activity was more than 100-fold greater than that of the intact bacteria, and injection of microgram quantities produced a response. 5. The distribution of histamine-sensitizing factor followed that of leukocytosis-stimulating activity. In contrast, mouse protective antigen was localized to the bacterial pellet.

Isolation and properties of the leukocytosis- and lymphocytosis-promoting factor of Bordetella pertussis.

The leukocytosis- and lymphocytosis-promoting factor (LPF) of Bordetella pertussis has been isolated to near homogeneity by physical, chemical, and electron microscopical criteria. LPF contains 14.5% nitrogen and is lipid and carbohydrate free. It is apparently composed of four polypeptide subunits. LPF caused leukocytosis and lymphocytosis in "nude" as well as in normal mice. In addition, purified LPF also induced histamine sensitization and hypoglycemia and refractoriness to the hyperglycemic effect of epinephrine. A monospecific LPF antiserum blocked these reactions as well as leukocytosis and lymphocytosis. LPF is clearly distinct from the hemagglutinating pili of B. pertussis.

Studies on the ultrastructure of Bordetella pertussis. I. Morphology, origin, and biological activity of structures present in the extracellular fluid of liquid cultures of Bordetella pertussis.

Two distinct particles have been recognized in the extracellular fluid of B. pertussis cultures. Both appeared to arise from the surface (cell wall) of the organism. One of these, a membranous particle, seemed to derive from long projections on the organism composed of the outer membrane of the cell wall. The second particle, a fine filament, was not readily comparable with any previously described bacterial structure. The two particles could be separated from each other by gradient centrifugation in CsCl. Lymphocytosis-promoting factor and histamine-sensitizing activity were only associated with fractions containing the fine filaments.

Studies on the leukocytosis and lymphocytosis induced by Bordetella pertussis. 3. The distribution of transfused lymphocytes in pertussis-treated and normal mice.

Peripheral blood lymphocytes were isolated from normal mice and mice undergoing pertussis-induced lymphocytosis. After labeling in vitro with tritiated uridine the cells were transfused into normal or pertussis-treated mice. It was found that the lymphocytes from pertussis-treated mice entered the lymph nodes of both normal mice and pertussis-treated mice to a significantly lesser extent than did normal lymphocytes which had been transfused into either class of recipient. In addition, an interdependence of changes in the various body compartments examined was found when normal lymphocytes were injected into either type of recipient. However, when pertussis lymphocytes were injected into normal mice there was no interrelationship between the changes in the node with those in the blood, liver, lung, or spleen. In the case of pertussis lymphocytes transfused into pertussis-treated mice no interrelationship between any two compartments was observed. It was concluded that in pertussis-treated mice there is an inhibition of lymphocyte emigration which is primarily the consequence of an effect on the cell.

The effect of Bordetella pertussis on lymphocyte cyclic AMP metabolism.

Bordetella pertussis culture fractions produce decreased metabolic responses to isoproterenol and epinephrine in mice and rats, suggesting the possibility of systemic beta adrenergic blockade. The present study was undertaken to elucidate the mechanism of the alteration in adrenergic responsiveness and to clarify its relationship to other biological effects of the organism. Lymphocytes were selected as a suitable tissue because of the marked alteration in lymphocyte distribution in pertussis-treated mice and rats, suggesting a change in the surface properties of these cells. Human peripheral blood lymphocytes, purified by nylon fiber chromatography, were studied. In short incubation experiments (20 min or less) B. pertussis did not alter the cyclic AMP response to isoproterenol, prostaglandin E (PGE(1)), or methacholine. However, when cells were preincubated with B. pertussis for 90 min at 37 degrees C, the responses to all three agents were markedly inhibited. Although these observations provide direct confirmation of the ability of B. pertussis to inhibit catecholamine responsiveness, the fact that PGE(1) and methacholine responses were also inhibited suggests that blockade at the level of the beta adrenergic receptor is doubtful. The inhibitory activity was localized in a nondialyzable, protein-rich fraction that is precipitated from B. pertussis culture fluid by ammonium sulfate at 90% of saturation. The bulk of the activity was obtained in the load volume after 50,000 g centrifugation in a cesium chloride gradient, density 1.2-1.5 (fraction 4). Fraction 4 produced a change in lymphocyte hormonal responsiveness at concentrations as low as 5 ng/ml. The relationship between cyclic AMP inhibitory activity in isolated human cells and leukocytosis-producing activity in intact mice was studied. The two activities seemed to parallel one another quite closely until the final Sephadex G-150 fractionation step, in which the two activities were obtained in the same column fraction, but a greater recovery of the leukocytosis-producing activity was obtained. Additional purification will be required to establish conclusively whether the same macromolecule is responsible for both activities. The availability of a bacterial product that markedly inhibits cyclic AMP accumulation in purified lymphocytes may help to clarify the role of cyclic AMP in lymphocyte activation by antigen and nonspecific mitogens.

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes. I. Proliferative response.

The lymphocytosis-promoting factor of Bordetella pertussis is a potent mitogen for murine lymphocytes in vitro. The stimulatory response was not the result of specific antigen stimulation. Spleen and lymph node cells were responsive, whereas normal thymocytes were unresponsive. However, DNA replication was induced in cortisone-resistant thymocytes by lymphocytosis-promoting factor (LPF). Bone marrow cells were not stimulated by LPF.

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes: II. Nature of the responding cells.

The mitogenic response of murine lymphocytes to the lymphocytosis-promoting factor of Bordetella pertussis has been shown to be due to activation of T cells. The selectivity of responsiveness to LPF with respect to the population of T cells which is stimllated, differs from that of PHA as well as Con A, and the surface receptors are different. A population of adherent cells, which does not appear to consist of macrophages or other phagocytic cells, is required for the T-cell response.

Purification and characterization of the major iron-regulated protein expressed by pathogenic Neisseriae.

This report describes a method to purify the major iron-regulated protein (MIRP) expressed by N. gonorrhoeae and N. meningitidis. This purification procedure involves maximal expression of the MIRP by growing the organisms on iron-limited media; cellular disruption by sonication followed by centrifugal fractionation; selective solubilization of the MIRP with the cationic detergent hexadecyltrimethylammonium bromide; cation-exchange chromatography in the presence of this detergent; and gel filtration chromatography. The MIRP purified by this technique migrates as a single band when analyzed by SDS-PAGE. The purified MIRP displayed an unusually basic isoelectric point, this value being greater than 9.35. Further biochemical analysis revealed the highly conserved nature of this protein isolated from the two pathogenic species of the genus Neisseria. For example, the amino acid composition of the meningococcal and gonococcal MIRPs were nearly identical and amino terminal sequence analysis showed that both shared the identical primary sequence through residue 48. Surprisingly, the first five NH2-terminal residues of the MIRPs exhibited homology with the first five residues of the gonococcal porin, protein I. Purified preparations of the MIRP exhibited a characteristic pink color reminiscent of the basic iron-binding protein lactoferrin. This observation coupled with the property of iron-regulation prompted us to analyze purified MIRP for iron-content. Approximately 0.5 mol iron per 1 mol of MIRP was detected. This study is the first to show that iron is associated with the MIRP, a property that may implicate this protein as playing a direct role in neisserial iron assimilation. While the precise function of the MIRP is not known, the availability of this protein in pure and biologically relevant quantities will allow further studies to elucidate its pathobiologic function.

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes. III. B-cell dependence for T-cell proliferation.

The nature of the helper lymphocytes in lymphocytosis-promoting factor (LPF)-induced proliferation was explored. Removal of macrophages from adherent splenocytes by either carbonyl-iron incubation or passage through Sephadex G-10 columns did not affect their synergistic function. Nor did cytolysis with Thy-1.2 antiserum and complement. The helper cells were found to be surface immunoglobulin-positive (sIg+) because they are retained by anti-Ig columns, susceptible to lysis by rabbit anti-mouse immunoglobulin and complement, and occurred in the sIg+ fractions of splenocytes after separation on the fluorescence-activated cell sorter. Further delineation of the surface markers on helper cells showed that complement receptors are not the determining marker for synergistic function. The requirement for B-helper cells in the stimulation of T lymphocytes by LPF is unique for a mouse of T-cell mitogen.