Communication: Truncated non-bonded potentials can yield unphysical behavior in molecular dynamics simulations of interfaces

Non-bonded potentials are included in most force fields and therefore widely used in classical molecular dynamics simulations of materials and interfacial phenomena. It is commonplace to truncate these potentials for computational efficiency based on the assumption that errors are negligible for reasonable cutoffs or compensated for by adjusting other interaction parameters. Arising from a metadynamics study of the wetting transition of water on a solid substrate, we find that the influence of the cutoff is unexpectedly strong and can change the character of the wetting transition from continuous to first order by creating artificial metastable wetting states. Common cutoff corrections such as the use of a force switching function, a shifted potential, or a shifted force do not avoid this. Such a qualitative difference urges caution and suggests that using truncated non-bonded potentials can induce unphysical behavior that cannot be fully accounted for by adjusting other interaction parameters

Shock Temperature of Stainless Steel and a High Pressure - High Temperature Constraint on Thermal Diffusivity of Al_2O_3

Time dependent shock temperatures were measured for stainless steel (SS) films in contact with transparent anvils. The anvil/window material was the same as the driver material so that there would be symmetric heat flow from the sample. Inferred Hugoniot temperatures, T_h , of 5800–7500 K at 232–321 GPa are consistent with previous measurements in SS. Temperatures at the film‐anvil interface (T_i ), which are more directly measured than T_h , indicate that T_i did not decrease measurably during the approximately 250 ns that the shock wave was in Al_2O_3 or LiF anvils. Thus an upper bound is obtained for the thermal diffusivity of Al_2O_3 at the metal/anvil interface at 230 GPa and 6000K of κ≤0.00096 cm_2/s. This is a factor of 17 lower than previously calculated values, resulting in a decrease of the inferred T_h by 730 k. The observed shock temperatures are combined with temperatures calculated from measured Hugoniots and are used to calculate thermal conductivities of Al_2O_3. Also we note that since there was no measurable intensity decrease during the time when the shock wave propagated through the window, we infer from this that Al_2O_3 remained transparent while in the shocked state. Thus sapphire is a good window material to at least 250 GPa for shock temperature measurements for metals

ДО ПИТАННЯ ПРО ЄДНІСТЬ ДВОРЯНСЬКОЇ ВЕРСТВИ (НА ПРИКЛАДІ КАТЕРИНОСЛАВСЬКОГО ДВОРЯНСТВА)

Встатті аналізуються внутрішньокорпоративні відносинидворянської верстви на прикладі Катеринославської губерніїCorporate Relationships ofNobility inKaterinoslavRegion are analyzed in this articl

Baryon-baryon scattering in the Gross-Neveu model: the large N solution

The scattering of two Dashen-Hasslacher-Neveu (DHN) baryons in the large N Gross-Neveu model is solved exactly using the relativistic, time-dependent Hartree-Fock approach. Unlike the special case of kink-antikink scattering, the scattering of DHN baryons is sensitive to the back-reaction of the fermions bound inside the baryons. Correspondingly the solution is much more complicated than the kink-antikink scattering solutions, which can be expressed in terms of sinh-Gordon solitons. Nevertheless, we present a simple ansatz form that gives closed analytic expressions for both the space-time dependent mean fields and the Dirac spinors for all continuum and bound states. The solution can also be applied to the scattering of polarons and solitons in conducting polymers.Comment: 22 pages, 5 figure

Advanced analytics to inform decision making during public health emergencies

The COVID-19 pandemic has led to significant understanding of evidence-informed decision making during public health emergencies. Imperial College London and the World Health Organization (WHO) Hub for Pandemic and Epidemic Intelligence (WHO Hub) jointly organized a workshop to generate an understanding of the context and ways in which advanced analytics were used for decision making during the COVID-19 pandemic and to identify opportunities to strengthen the data-to-decisions pathways. Held on 9 – 10 May 2023 at the WHO Hub in Berlin, Germany, the workshop brought together mathematical modellers specialized in infectious disease modelling and scientists based at academic institutions, public health agencies, or Ministries of Health, and public health decision makers. The workshop was conducted in four interactive group activities. The dialogue among participants led to the identification of potential opportunities for support and actions to strengthen the use of outputs from advanced analytics for decision making. These opportunities could be actions to strengthen processes and structures, improve workflows, find consensus on ways of working together, establish a knowledge foundation for support, and jointly drive evidence-based decision-making priorities for epidemic and pandemic preparedness. Workshop participants highlighted further need to capture additional perspectives held by actors from diverse geographical areas, contexts, and roles who were not present at the workshop, and political decision makers to enrich the understanding of the different priorities for advanced analytics for decision making in different regional and local contexts. The workshop highlighted the benefit in bringing together experts from around the globe to share experience and lessons learned to identify priority activities to tackling challenges and improve the way advanced analysis is perceived and used for policy and response decision making. Overall, this workshop has contributed to a longstanding global dialogue on processes and systems to facilitate knowledge translation from data to decisions. Workshop participants collectively identified the need to develop a global network of advance analytics experts, with regional hub coordination to ensure inclusion and capacity building at local level. A network of modelers would be an interconnected community that would contribute to pandemic and epidemic rapid response while collectively improve how data are analyzed, actionable insights shared to inform decisions during public health emergencies and how models are evaluated and improved jointly

RNA expression of TLR10 in normal equine tissues

Background: Toll like receptors are one of the major innate immune system pathogen recognition systems. There is little data on the expression of the TLR10 member of this family in the horse. Results: This paper describes the genetic structure of the Equine TLR10 gene and its RNA expression in a range of horse tissues. It describes the phylogenetic analysis of the Equine TLR1,6,10,2 annotations in the horse genome, firmly identifying them in their corresponding gene clades compared to other species and firmly placing the horse gene with other TLR10 genes from odd-toed ungulates. Additional 3’ transcript extensions to that annotated for TLR10 in the horse genome have been identified by analysis of RNAseq data. RNA expression of the equine TLR10 gene was highest in peripheral blood mononucleocytes and lymphoid tissue (lymph nodes and spleen), however some expression was detected in all tissues tested (jejunum, caudal mesenteric lymph nodes, bronchial lymph node, spleen, lung, colon, kidney and liver). Additional data on RNAseq expression of all equine TLR genes (1–4 and 6–10) demonstrate higher expression of TLR4 than other equine TLRs in all tissues. Conclusion: The equine TLR10 gene displays significant homology to other mammalian TLR10 genes and could be reasonably assumed to have similar fuctions. Its RNA level expression is higher in resting state PBMCs in horses than in other tissues

Universal finite-size scaling for percolation theory in high dimensions

We present a unifying, consistent, finite-size-scaling picture for percolation theory bringing it into the framework of a general, renormalization-group-based, scaling scheme for systems above their upper critical dimensions $d_c$. Behaviour at the critical point is non-universal in $d>d_c=6$ dimensions. Proliferation of the largest clusters, with fractal dimension $4$, is associated with the breakdown of hyperscaling there when free boundary conditions are used. But when the boundary conditions are periodic, the maximal clusters have dimension $D=2d/3$, and obey random-graph asymptotics. Universality is instead manifest at the pseudocritical point, where the failure of hyperscaling in its traditional form is universally associated with random-graph-type asymptotics for critical cluster sizes, independent of boundary conditions.Comment: Revised version, 26 pages, no figure

The effect of loading direction and Sn alloying on the deformation modes of Zr: An in-situ neutron diffraction study

Deformation modes (slip and twining) in a strongly textured model hcp alloy system (Zr–Sn) have been investigated using in-situ neutron diffraction and deformation along with complementary electron microscopy. Analysis of the evolution of the intergranular strain evolutions and intensity of specific reflections from neutron diffraction show differential influence of Sn on the extent of twinning too, depending on the deformation direction. While Sn displayed very noticeable influence on twin activity when samples were compressed along a direction that predominantly activates prismatic slip, this effect was not seen when samples were compressed along other different directions. These experimental observations were successfully simulated using a CPFE (crystal plasticity finite element) model that incorporates composition sensitive CRSS (critical resolved shear stress) for slip and composition insensitive CRSS activation of twinning. The success of the CPFE model in capturing the experimental observations with respect to twin evolution suggests that the twinning in Zr is chiefly governed by the initial crystallographic texture and the associated intergranular stress state generated during plastic deformation

Effect of extrusion on the nutritional value of soybeans and sorghum grain in finishing pigs

A total of 112 finishing pigs (avg initial wt of 139 lb) was used to determine the effects of adding extruded soybeans and/or sorghum grain to diets for finishing pigs. Treatments were: 1) sorghum-soybean meal control (sorghum-SBM), 2) extruded soybeans and ground sorghum, 3) SBM and extruded sorghum, and 4) extruded soybeans and sorghum. All diets were isocaloric and isolysinic. Using extruded soybeans and/or sorghum improved efficiency of gain compared to the sorghum-SBM control. This response was apparently related to the improved digestibilities of dry matter and nitrogen with the use of extruded ingredients. Optimum digestibility of dry matter and nitrogen was achieved when just the sorghum was extruded, but optimum growth performance (ie., efficiency of gain) was achieved when extruded sorghum and soybeans were added to the diet.; Swine Day, Manhattan, KS, November 15, 199

Effects of daily porcine somatotropin administration on tile performance and carcass characteristics of finishing swine

One hundred forty-four pigs (72 barrows and 72 gilts) were utilized in six treatments with six pens each to evaluate four levels of daily porcine somatotropin (pST) injections (0, 1, 3, or 5 mg/d) in combination with diets containing 13 or 16% crude protein (CP). One randomly selected pig from each pen was slaughtered when it reached a weight between 230 and 240 lb. Daily feed intake (ADFI), tenth rib backfat, and estimated percentage of lean pork were reduced in pigs fed the 13% CP diet and injected with 3 mg/d pST compared to pigs fed the same diet and injected daily with a placebo. Feed intake was reduced in pigs fed the 16% CP diet and injected daily with 3 and 5 mg/d pST. Improvement in feed conversion (F/G), tenth rib backfat, and estimated percentage lean pork occurred when pigs fed the 16% CP diet were injected with 1 mg/d, with greater improvements occurring at the 3 and 5 mg/d levels of pST. The improvement in F/G and the greater magnitude of response observed in pigs fed 16% CP diets compared to the response of pigs fed the 13% CP diet indicate that both the performance and carcass characteristics of pigs injected with pST are dependent on the dietary CP content.; Swine Day, Manhattan, KS, November 16, 198