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Electrification to reduce or eliminate greenhouse gas emissions is essential to mitigate climate change. However, a substantial portion of our manufacturing and transportation infrastructure will be difficult to electrify and/or will continue to use carbon as a key component, including areas in aviation, heavy-duty and marine transportation, and the chemical industry. In this Roadmap, we explore how multidisciplinary approaches will enable us to close the carbon cycle and create a circular economy by defossilizing these difficult-to-electrify areas and those that will continue to need carbon. We discuss two approaches for this: developing carbon alternatives and improving our ability to reuse carbon, enabled by separations. Furthermore, we posit that co-design and use-driven fundamental science are essential to reach aggressive greenhouse gas reduction targets.

Interdiffusion experiments are usually time-consuming and tedious since diffusion couples must be annealed at several temperatures for a long time. The efforts required to study interdiffusion in multicomponent alloys increase dramatically as multiple diffusion couples are required to cover broad composition ranges and determine the diffusivities of individual elements in different chemical environments. To circumvent this challenge, we present a high-throughput approach applicable to single-phase and compositionally complex alloys, which are assumed to approximate ideal solid solutions. Here, a simple diffusion-multiple experiment combined with a physically based kinetic model is proposed to efficiently determine the diffusion coefficients of the constituent elements in quaternary CrFeCoNi alloys. Compared with tracer diffusivities reported in the literature, the results, thus, obtained do not differ by more than a factor of 2 and were obtained from a single interdiffusion experiment. In contrast, the diffusivities simulated with commercial mobility and thermodynamic databases are strongly overestimated by a factor ranging from 1 to 16. Therefore, our approach enables high-throughput determination of diffusivities and can help in the design of alloys for high-temperature applications where diffusion plays a key role. [ABSTRACT FROM AUTHOR]

Eukaryotic enhancers act over very long distances, yet still show remarkable specificity for their own promoter. To better understand mechanisms underlying this enhancer-promoter specificity, we used transvection to analyze enhancer choice between two promoters, one located in cis to the enhancer and the other in trans to the enhancer, at the yellow gene of Drosophila melanogaster. Previously, we demonstrated that enhancers at yellow prefer to act on the cis-linked promoter, but that mutation of core promoter elements in the cis-linked promoter releases enhancers to act in trans. Here, we address the mechanism by which these elements affect enhancer choice. We consider and explicitly test three models that are based on promoter competency, promoter pairing, and promoter identity. Through targeted gene replacement of the endogenous yellow gene, we show that competency of the cis-linked promoter is a key parameter in the cis-trans choice of an enhancer. In fact, complete replacement of the yellow promoter with both TATA-containing and TATA-less heterologous promoters maintains enhancer action in cis.

Spt5 and Spt6 have been found to be associated with active transcription and have characteristics of general elongation factors in Drosophila melanogaster. Drosophila homologs of Spt5 and Spt6 have been identified. Their localization on Drosophila polytene chromosomes was studied.

Research supports the role of the TATA box and initiator element in regulating chromosomal transcription. Using a Drosophila yellow gene as a test case, researchers determined that by altering two core promoter elements via gene replacement, the results would provide alleles that could support transvection.

The effect of a new group housing system on performance (132 gilts and litters) and endocrinological (35 gilts) and immunological functions (28 gilts) was studied. Animals were randomly assigned to a conventional system (control), involving > 2 mo in individual stalls, or to the Hurnik-Morris (H-M) housing system, involving continuous housing in small groups, for breeding-gestating swine. The gilts were reared throughout gestation in their respective housing systems and moved 3 to 5 d prefarrowing to a common farrowing facility. Various production data were collected, including sow weight and backfat measurements, number of pigs born, number born alive, number weaned, litter birth weight, and litter weaning weight. An adrenal function test using dexamethasone pretreatment and [ACTH.sub.1-24] challenge was imposed on gilts 5 d prebreeding and once between d 81 to 87 of gestation. Plasma progesterone was measured at the same time. Immune function was measured by serum antibody response to hen egg white lysozyme (HEWL) and delayed-type hypersensitivity (DTH) to tuberculin. Gilts reared in the H-M housing system exhibited a number of pigs weaned per litter and litter weaning weights comparable to the number and weights in the control system (7.3 [+ or -] .33 vs 6.9 [+ pr -] .38, P = .421 and 56.9 [+ or -] 2.42 kg vs 51.3 [+ or -] 2.76 kg, P = .132, respectively). Prefarrowing and weaning backfat measurements were significantly reduced in group-housed gilts (15.8 [+ or -] .45 mm vs 17.8 [+ or -] .55 mm, P = .005 and 14.6 [+ or -] .4 mm vs 16.2 [+ or -] .42 mm, P = .008, respectively). Adrenocortical function and plasma progesterone were not different between gilts in different housing systems. Antibody response to HEWL and inflammatory response was numerically but not significantly greater for gilts reared in the H-M housing system than for those in the control system. The results of this study provided encouragement for the development of group housing without compromising production or endocrinological and immunological functions in breeding-gestating sows., Results of a study indicated that group housing systems such as the Hurnik-Morris (H-M) method can be used for rearing gilts without affecting their productive capacity, immune reaction or endocrinological functions. Gilts in the experimental group were reared were placed in the H-M system with six gilts in each pen while those in the control group were housed in traditional pens involving long duration of isolated confinement. Group housing systems, designed after the study of pigs' social behavior, can provide an alternative to the traditional system of intensive housing.

Hunter, Schmidt, and Coggin (1988) criticized the application of capital budgeting techniques to the evaluation of personnel programs. The argued that many of these methods are often conceptually and logically inappropriate, that they may be logically inapplicable with unintended consequences, and that there is no single correct definition of utility. Three problems with Hunter et al.'s argument are discussed in this article. First, Hunter et al.'s presentation of capital budgeting is inconsistent with widely recognized capital budgeting methods, such as discounting, for the evaluation of personnel programs. Second, Hunter et al. used unrealistic examples constructed to facilitate their critique. Third, Hunter et al.'s argument encourages continued imprecise measurement and presentation of the costs and benefits of personnel programs. In the aggregate, such arguments serve to narrow, rather than broaden, the perspective of personnel psychology. (Reprinted by permission of the publisher.)

Large scale simulations of crystal nucleation from the liquid are performed using the Lennard-Jones potential to determine the time required for nucleation. By considering both transient and finite-size effects, we for the first time successfully predict the nucleation time without any parameter fitting in the Lennard-Jones system. All necessary parameters are derived from separate, equilibrium simulations. At small undercoolings, large system size effects are observed. The required system size is not only determined by the size of the critical nuclei, but also the characteristic spacing between them. Two distinct nucleation regions are predicted by theory and observed by the simulations, which are dominated by the transient time and the steady-state nucleation time, respectively. [ABSTRACT FROM AUTHOR]

Purpose: This study presents a new rat oral implant model for assessing histologic changes in the mechanical environment surrounding loaded and unloaded dental implants. Materials and Methods: The maxillary left first molar from retired breeder rats was extracted, and the site was allowed to heal for 1 month. A titanium miniscrew implant was then placed into the site and allowed to heal for 21 days. The mandibular left first molars in one group of rats were extracted to create an unloaded condition; in a second group of rats the mandibular left first molars were left in occlusion with the opposing screw head to simulate loading. Radiographs were taken on the day of placement and again at 7 days, 14 days, and 21 days after placement and were used to estimate the bone-implant contact ratio. The rats were sacrificed after 21 days. Peri-implant tissue samples from day 21 were processed for histology and immunohistochemistry with antibodies to osteocalcin and matrix metalloproteinase 13 (MMP- 13). Two-dimensional finite element models were created from images of the histologic sections and immunohistochemical samples to observe tissue changes. Results: Areas of high shear stress adjacent to the helical threads of loaded implants were associated with osteocalcin localization and bone formation but only minimal localization of MMP-13. Bone adjacent to unloaded implants showed fibrous tissue and extensive MMP-13 localization surrounding the apical two-thirds of each implant. These results agree with estimated bone-implant contact ratios, which showed a steady decrease in contact ratio for the unloaded implant group but a significantly higher contact ratio in the loaded group between 14 and 21 days. Conclusion: The rat oral implant model is useful for studies of the mechanical and physiologic environment affecting osseointegration in loaded and unloaded implants. [ABSTRACT FROM AUTHOR]

We have calculated the interfacial free energy for the hard-sphere system, as a function of crystal interface orientation, using a method that examines the fluctuations in the height of the interface during molecular dynamics simulations. The approach is particularly sensitive for the anisotropy of the interfacial free energy. We find an average interfacial free energy of γ=0.56±0.02kBTσ-2. This value is lower than earlier results based upon direct calculations of the free energy [R. L. Davidchack and B. B. Laird, Phys. Rev. Lett. 85, 4751 (2000)]. However, both the average value and the anisotropy agree with the recent values obtained by extrapolation from direct calculations for a series of the inverse-power potentials [R. L. Davidchack and B. B. Laird, Phys. Rev. Lett. 94, 086102 (2005)]. [ABSTRACT FROM AUTHOR]

First-principles molecular dynamics simulations are carried out to study the structures, dynamics, and electronic properties of liquid Al88Si12 in the temperature ranging from 898 to 1298 K. The temperature dependence of static structure factors, pair correlation functions, and electronic density-of-states are investigated. The structural properties obtained from the simulations are in good agreement with the x-ray diffraction experimental results. © 2005 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We have calculated the free energy of the crystal-melt interface for the Lennard-Jones system as a function of crystal orientation, near zero pressure, by examining the roughness of the interface using molecular dynamic simulations. The anisotropy is weak, but can be accurately resolved using this approach due to the sensitivity of the fluctuations on the anisotropy. We find that the anisotropy can be described well using two parameters, based upon a low-order expansion satisfying cubic symmetry. The results are in good agreement with previous calculations of the free energies, based upon simulations used to calculate the reversible work required to create the interfaces. The weak anisotropy is also in reasonable agreement: The work here and the work of Davidchack and Laird [R. L. Davidchack and B. B. Laird, J. Chem. Phys. 118, 7651 (2003)] both predict γ[SUB100]>Γ[SUB110]>γ[SUB111]. The only discrepancy is that we find a smaller value for the difference γ[SUB100]-γ[SUB111] by an amount larger than the combined error bars. [ABSTRACT FROM AUTHOR]