bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Waste Glass in Polymer Concrete
Authors: Hodul Jakub , Hodná Jana , Drochytka Rostislav , Vyhnánková Michaela
Published: August 2016

Glass waste is currently produced almost in all developed countries. It is the silicate based waste material which after suitable treatment has found application in many industries and therefore some types of waste glass belong to progressive secondary raw materials. However, the use of this silicate waste material which differ on the basis of an initial use of the glass in its physical and mechanical properties has not been fully explored in the field of building industry – the production of building materials. The replacement of the common filler – quartz sand in the polymer concrete (PC) could be one of the effective possibilities of the utilization of different type of waste glass in the building industry. Mainly for this reason, this work deals with the experimental examining the possibility of using various types of waste glass in the polymer concrete based on epoxy resin.
Testing of Possible Use of Fine-Grained Alkali Activated Composites in the Construction Industry
Authors: Mec Pavel , Boháčová Jana , Závrský Petr
Published: August 2016

Alkali-activated materials are formed by the alkaline activation of inorganic materials and are characterized by the wide range of potential use. The objective of experiment was to investigate the possibility of use fine-grained alkali activated composites in the construction industry. Selected properties of alkali-activated systems based on granulated blast furnace slag and fine-grained aggregates were determined. At the beginning of the experiment, different samples prepared of 3 types of activators were tested, basic properties (time of workability, initial and final setting time, compressive and flexural strength) and also a possibility of selected retarder use was determined. Then, samples with the best potencial to presumed use were tested in detail and a possibility use as a substitute for selected construction materials were evaluated.
On the basis of determined properties, prepared composites could be used as reprofiling mortars, materials for cracks repairing or socle plasters.
The Reliability Analysis of the Initiation Time for RC Members under Chlorine Salt Ingress and Local Micro-Climate
Authors: Jiao Jun Ting , Ye Ying Hua , Wang Chen Fei , Ye Guo Chen
Published: August 2016

The initiation time of reinforcement was researched for reinforced concrete (RC) members along coast regions under chlorine salt ingress and local micro-climate. Based existing chlorine erosion model, when local temperature and relative humidity were considered, the initiation time of reinforcement for RC members were calculated by using Monte-Carlo method, and the influence parameters of the initiation time were researched. According to probability theory, the probability distribution and density of the initiation time was given for RC members in tropical, subtropical and temperate zone along coast in china, for example Haikou City, Shanghai City, and Tianjin City. The research results showed: The impact on the initiation time from local temperature and relative humidity should not be ignored. It should be reasonable to consider when RC members were designed. This would be useful for structure strengthening, maintenance, and remaining life prediction.
Producing High Strength Hollow Core Reinforced Concrete Slab with Silica Fume and Polypropylene Fibers
Authors: Castil Evalyn Joy , Tarranza Nathaniel C.
Published: August 2016

The compressive strength and workability of concrete mixes with the same proportion of cement, sand, gravel and water but with different amounts of silica fume and polypropylene fiber admixtures were investigated. The same concrete mixes were used for producing hollow core reinforced concrete (HCRC) slab-strip samples tested for flexural strength under third-point loading. The HCRC slab-strip samples were reinforced with the same number and size of reinforcing bars. Silica fume content of 0%, 5%, 10%, 15% and 20% by weight of cement, in combination with polypropylene fiber at 0 kg , 0.40 kg , 0.60 kg and 0.80 kg per cubic meter of concrete, were added into the concrete mix. Tests demonstrate that there is an optimum combination of silica fume and polypropylene fiber for maximum gain in concrete compressive strength of the concrete mix, and another optimum combination of the same admixtures for optimal gain in flexural strength of the HCRC slab-strip samples produced using the concrete mix.
Impact of Tool Pin Geometry and Optimized Process Parameters on Mechanical Properties of Friction Stir Welded AZ80A Mg Alloy
Authors: Jaiganesh V. , Nagarajan P.K. , Sevvel P. , Dhileep Kumar J. , Manivannan S.
Published: August 2016

In this paper, the influence of optimized FSW process parameters namely tool rotational speed, feed rate, mechanical axial force and impact of tool pin geometry on the mechanical properties of AZ80A Mg alloy are experimentally investigated in a detailed manner. M35 grade High Speed Steel (HSS) tool with three different pin geometries namely straight cylindrical, threaded cylindrical and taper cylindrical was employed in this investigation. The joints obtained under these conditions are subjected to tensile tests as per ASTM (American Society for Testing and Materials) B557M – 10 standards and tensile fracture surfaces are examined using optical and Scanning Electron Microscope (SEM). The investigations proved that defect free sound joints with better mechanical properties are produced by taper cylindrical tool pin geometry under optimized process parameter values. It was experimentally found that the optimized FSW process parameter values namely 1.0 mm/min feed rate, 5 kN axial force, 1000 rpm of tool rotational speed along with a taper cylindrical pin profiled tool is preferable for FSW of AZ80A Mg alloy of 5mm thickness.Moreover, this experimental work revealed us that the taper cylindrical pin profiled tool fabricated sound, defect free welded joints along with better & improved mechanical properties when compared with other two pin profiles.
Effect of Hydroxyl Concentration on the Structural and Optical Properties of Zinc Oxide Nanoparticles
Authors: Pelicano Christian Mark , Mulimbayan Francis
Published: August 2016

Zinc oxide (ZnO) nanoparticleswere successfully synthesized by chemical precipitation method at different hydroxyl concentrations. The resulting nanoparticles are characterized by transmission electron microscopy (TEM), ultraviolet-visible (UV-VIS) and photoluminescence (PL) spectroscopy. From TEM images, the measured average sizes of the nanoparticles were 4.45 nm to 5.26 nm. Selected area diffraction(SAED) patternsconfirmed that the nanoparticles were of highly crystalline ZnO having wurtzitephase structure.The energy band gap values red-shifted from 3.79 to 3.64 eV based from excitonic absorption peaks. All the samples exhibited a strong visible emission and decreasing peak intensity in increasing OH- concentration.
Antibacterial Properties of Unique Urchin-Like CuO Nanostructures by Chemical Bath Deposition
Authors: Felizco Jenichi Clairvaux , Mulimbayan Francis
Published: August 2016

Unique urchin-like CuO nanostructures were successfully synthesized by a simple chemical bath deposition method at low temperature of 70°C in a short reaction time of 1h. XRD pattern revealed the presence of pure crystalline monoclinic CuO. Morphological analysis revealed the formation of spherical structures composed of numerous hair-like structures arranged in an urchin-like fashion. A plausible growth mechanism was proposed in this paper. Antibacterial test revealed that the nanostructures successfully inhibited the growth of both S. aureus and E. coli.
Influence of Gel Aging Time on the Properties of Various Silica Aerogels Synthesized from Water Glass
Authors: Yücel Sevil , Karakuzu Ikizler Burcu , Terzioğlu Pınar , Temel Tülay Merve
Published: August 2016

In the present paper, water glass was used to synthesize silica aerogels and calcium magnesium silica aerogels. The present research was aimed to investigate the effect of gel aging time (1 and 24 hours) on the physical and surface properties of aerogels. Brunauer-Emmett-Teller, Barrett-Joyner-Halenda, Fourier Transform Infrared spectroscopy and scanning electron microscopy techniques were used to characterize aerogels. Successful formation of nanopores (2.8-4.4 nm) was approved by N2 adsorption/desorption isotherms. The aerogels contained porous network structure with different surface areas (388.9-729.9 m2 g-1). Aging for longer times led to an ability to decrease the density of the aerogels. The bulk density was higher in silica aerogels than in calcium magnesium silica aerogels. The well-tailored network matrix with high BET surface area (729.9 m2 g-1) and low density (0.116 g cm-3) was achieved via 24 hours gel aging of calcium magnesium silica aerogel.
Identification of Kinematic Hardening Material Parameters for Martensitic Steel Sheets
Authors: Song Jung Han , Park J.S. , Lee C.A. , Kim H.Y. , Choi W.H.
Published: August 2016

The identification of the material models which are used in the finite element analysis for the forming operation and springback are very important in terms of accurate predictions. The aim of this paper is to characterize both the anisotropy and the hardening of the ultra-high strength steel such as martensitic steel (MS steel) in order to identify material parameters of constitutive equation, which able to reproduce the mechanical behavior. Uniaxial tensile tests were carried out for characterizing the anisotropic plastic behavior of the MS steel. Cyclic tests under tension-compression load were also carried out for characterizing the Bauschinger effect during reverse deformation. Yoshida-Uemori hardening model associated with orthotropic yield criterion Hill’s 1948 is used to represent the in-plane mechanical behavior of the martensitic steel. The resented results show a very good agreement between model predictions and experiments: flow stresses during loading and reverse loading are well reproduced.
Effect of Temperature and Cooling Rate on the Microstructures of 35MnB and 25Mn Tubes during Heat Treatment
Authors: Jung Sun Ho , Lee S. , Lee J.
Published: August 2016

Band structures with pearlite and ferrite aligned as stripes can be created during the heat treatment of carbon steel. Since band structures undermine the mechanical quality of end products, it is highly important to select a process condition that will not create band structures as a result of heat treatment. This study verified the effect of temperature and cooling rate on the creation of band structures during heat treatment of 35MnB and 25Mn steel tubes for drive shafts and also considered the optimal process conditions to remove band structures or prevent their creation. The experimental results suggest that, during heat treatment of 35MnB and 25Mn steel tubes, it is most effective to ensure a cooling rate faster than furnace cooling in order to prevent band structures.
Belite Cement Prepared from High Carbon-Content Fly Ash
Authors: Wan Yuan Yuan , Fang Yong Hao
Published: August 2016

Stockpiled high carbon-content fly ash and lime was used to prepare belite cement by hydrothermal reaction followed by low temperature calcination. Sodium hydroxide was added as an activator to accelerating the reaction. 0-1.5 wt% Na2O equivalent NaOH was added as a aqueous solution into the mixture of 20 wt%-35 wt% CaO and 65 wt%-80 wt% fly ash. The mixture was formed into granules and steam-curing the at 97°C for 12 h, followed by heating at 800°C for 1 h. The results show that adding 1.0 wt% Na2O to the mixture of fly ash and CaO can efficiently promote the hydrothermal reaction. Belite cement with practicable strength and characterized by rapid setting and high sulfate attack resistance was synthesized.
Plane Waves of Dilatation in Auxetic Bulk Solids
Authors: Lim Teik Cheng
Published: August 2016

This paper addresses the problem of the speed of plane waves of dilatation, in which the impacted end is sustained so as to maintain constant strain behind the wave front, through auxetic solids considering density correction; the importance of this work can be inferred from the lack of knowledge on this type of material. Results for the dimensionless wave speed reveal that the Poisson’s ratio magnitude and the strain play primary and secondary roles, respectively. In addition, there is better control of wave speed in the auxetic region than in the conventional region due to a more gradual change of the wave speed in the former. Hence the use of auxetic materials facilitates better passive control of wave propagation in bulk solids.
Study of the Technical Capability of Sugarcane Bagasse Ash in Concrete Production
Authors: da Cruz Sessa Thiago , Silvoso Marcos Martinez , Vazquez Elaine , Qualharini Eduardo Linhares , Haddad Assed Naked , Amaral Alves Lais
Published: August 2016

Cement industry has a great contribution to CO2 emissions in the world. In order to reduce the levels of CO2 emissions and the consequences of global warming, some researches have been developed aiming to reduce the cement volume produced through mineral mixtures. Sugarcane bagasse ash (SCBA) represents an important environmental liability of the alcohol industry in the northern state of Rio de Janeiro and its use as a partial replacement of Portland cement in concrete has shown great potential for use. This paper aims to analyze, through experimental procedures, the consistency and mechanic strength on concrete with low environmental impact, made from sugarcane bagasse ash, in substitution levels of 20% and 40%. The methodology of the experimental program, included the steps of characterizing the materials; definition of the reference concrete; molding and dosing of the reference concrete and concrete with SCBA; mechanical tests to evaluate the resistance in the reference test bodies; and analysis of the results. The method used from production and processing of the ash to the characterization of other materials in the concrete are also addressed in this study. The results indicate the feasibility of using sugarcane bagasse ashes in application of concretes in the construction industry.
Effect of Substitution of Crushed Waste Glass as Partial Replacement for Natural Fine and Coarse Aggregate in Concrete
Authors: Olofinnade Oluwarotimi Michael , Ndambuki Julius M. , Ede Anthony N. , Olukanni David O.
Published: August 2016

Reusing of waste glass in concrete production is among the attractive option of achieving waste reduction and preserving the natural resources from further depletion thereby protecting the environment and achieving sustainability. This present study examines the possible reuse of waste glass crushed into fine and coarse aggregate sizes as partial substitute for natural fine and coarse aggregate in concrete. The variables in this study is both the fine and coarse aggregate while the cement and water-cement ratio were held constant. The crushed glass was varied from 0 – 100% in steps of 25% by weight to replace the both the natural fine and coarse aggregate in the same concrete mix. Concrete mixes were prepared using a mix proportion of 1:2:4 (cement: fine aggregate: coarse aggregate) at water-cement ratio of 0.5 targeting a design strength of 20 MPa. Tests were carried out on total number of 90 concrete cube specimens of size 150 x 150 x150 mm and 90concrete cylinder specimens of dimension 100 mm diameter by 200 mm height after 3, 7, 14, 28, 42 and 90 days of curing. Test results indicated that the compressive and split tensile strength of the hardened concrete decreases with increasing waste glass content compared with the control. However, concrete mix made with 25% waste glass content compared significantly well with the control and can be suitably adopted for production of light weight concrete.
Economic Exploitation of Gravel in Place of Granite in Concrete Production
Authors: Bamigboye Gideon , Ede Anthony N. , Raheem Ayinde A. , Olofinnade Oluwarotimi Michael , Okorie Uche
Published: August 2016

The paper investigated the application of gravel as partial economic replacement of granite in concrete production. Concrete was produced using granite/gravel combination in varying percentages of 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, 20/80 and 10/90. Concrete made from 100 % granite and 100 % gravel served controls while other constituents of concrete were kept constant. Two different mix ratios of 1:2:4 and 1:3:6 were employed. Sieve analysis was carried out on the aggregates, while slump and compaction factor tests were carried out on fresh concrete. Compressive strength tests were performed on hardened concrete. Specimens were produced using 150 mm cubes for compressive tests. The reliable percentage of granite/gravel combination from compressive strength view point 60/40 with a value of 21.15 N/mm2 for mix ratios 1:2:4 and 70/30 with 15.17 N/mm2 for 1:3:6 mix ratio at 28 days. Satisfying respectively the 20 N/mm2 and 15.17 N/mm2 minimum requirement of BS 8110: 1997.There were costs saving of 4 % per unit volume of concrete production for both 1:2:4 and 1:3:6 respectively. Empirical evidence from the regression analysis revealed that higher composition of gravel significantly improves the concrete consistency properties while greater proportions of granite do significantly enhance comprehensive strength.
Influence of Mineral Admixtures on Fracture Energy of Refractory Cement at Elevated Temperatures
Authors: Geethakumari B. , Ramesh Kumar R. , Syam Prakash V.
Published: August 2016

The influence of three mineral admixtures, Silica Fume (SF), Fly Ash (FA), and Rice Husk Ash (RHA) on the fracture energy of Refractory Cement (RC) over a wide range of temperature from 300K to 1173K is studied. The optimum percentage replacement of RC by these admixtures is found to be around 0.5 for all the temperatures considered but for FA. Fracture energy of control (0% admixture) and blended RC (with 0.5% admixture) are determined by three point bending of notched beam specimens. Fracture energy of RC blended with the three mineral admixtures is lower than that of control RC for temperature range of 300K to 873K. But at elevated temperature of 1173K, blending plays its role as an admixture. Experimental results are corroborating with XRD. It is observed that phenomenon of pseudo dryness of Gismondine in the blended RC causes higher fracture energy which is double that of RC only at 1173K.
Suppression of Glut1 and Glucose Metabolism by Decreased Akt/mTORC1 Signaling Drives T Cell Impairment in B Cell Leukemia
Authors: Siska Peter J. , van der Windt Gerritje J. W. , Kishton Rigel J. , Cohen Sivan , Eisner William , MacIver Nancie J. , Kater Arnon P. , Weinberg J. Brice , Rathmell Jeffrey C.
Published: August 2016

Leukemia can promote T cell dysfunction and exhaustion that contributes to increased susceptibility to infection and mortality. The treatment-independent mechanisms that mediate leukemia-associated T cell impairments are poorly understood, but metabolism tightly regulates T cell function and may contribute. In this study, we show that B cell leukemia causes T cells to become activated and hyporesponsive with increased PD-1 and TIM3 expression similar to exhausted T cells and that T cells from leukemic hosts become metabolically impaired. Metabolic defects included reduced Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling, decreased expression of the glucose transporter Glut1 and hexokinase 2, and reduced glucose uptake. These metabolic changes correlated with increased regulatory T cell frequency and expression of PD-L1 and Gal-9 on both leukemic and stromal cells in the leukemic microenvironment. PD-1, however, was not sufficient to drive T cell impairment, as in vivo and in vitro anti–PD-1 blockade on its own only modestly improved T cell function. Importantly, impaired T cell metabolism directly contributed to dysfunction, as a rescue of T cell metabolism by genetically increasing Akt/mTORC1 signaling or expression of Glut1 partially restored T cell function. Enforced Akt/mTORC1 signaling also decreased expression of inhibitory receptors TIM3 and PD-1, as well as partially improved antileukemia immunity. Similar findings were obtained in T cells from patients with acute or chronic B cell leukemia, which were also metabolically exhausted and had defective Akt/mTORC1 signaling, reduced expression of Glut1 and hexokinase 2, and decreased glucose metabolism. Thus, B cell leukemia–induced inhibition of T cell Akt/mTORC1 signaling and glucose metabolism drives T cell dysfunction.
A Histone Methyltransferase ESET Is Critical for T Cell Development
Authors: Takikita Shoichi , Muro Ryunosuke , Takai Toshiyuki , Otsubo Takeshi , Kawamura Yuki I. , Dohi Taeko , Oda Hiroyo , Kitajima Masayuki , Oshima Kenshiro , Hattori Masahira , Endo Takaho A. , Toyoda Tetsuro , Weis John , Shinkai Yoichi , Suzuki Harumi
Published: August 2016

ESET/SETDB1, one of the major histone methyltransferases, catalyzes histone 3 lysine 9 (H3K9) trimethylation. ESET is critical for suppressing expression of retroviral elements in embryonic stem cells; however, its role in the immune system is not known. We found that thymocyte-specific deletion of ESET caused impaired T cell development, with CD8 lineage cells being most severely affected. Increased apoptosis of CD8 single-positive cells was observed, and TCR-induced ERK activation was severely inhibited in ESET−/− thymocytes. Genome-wide comprehensive analysis of mRNA expression and H3K9 trimethylation revealed that ESET regulates expression of numerous genes in thymocytes. Among them, FcγRIIB, whose signaling can inhibit ERK activation, was strongly and ectopically expressed in ESET−/− thymocytes. Indeed, genetic depletion of FcγRIIB in ESET−/− thymocytes rescued impaired ERK activation and partially restored defective positive selection in ESET−/− mice. Therefore, impaired T cell development in ESET−/− mice is partly due to the aberrant expression of FcγRIIB. Collectively, to our knowledge, we identify ESET as the first trimethylated H3K9 histone methyltransferase playing a crucial role in T cell development.
Regulatory T Cell Numbers in Inflamed Skin Are Controlled by Local Inflammatory Cues That Upregulate CD25 and Facilitate Antigen-Driven Local Proliferation
Authors: Billroth-MacLurg Alison C. , Ford Jill , Rosenberg Alexander , Miller Jim , Fowell Deborah J.
Published: August 2016

CD4+Foxp3+ regulatory T cells (Tregs) are key immune suppressors that regulate immunity in diverse tissues. The tissue and/or inflammatory signals that influence the magnitude of the Treg response remain unclear. To define signals that promote Treg accumulation, we developed a simple system of skin inflammation using defined Ags and adjuvants that induce distinct cytokine milieus: OVA protein in CFA, aluminum salts (Alum), and Schistosoma mansoni eggs (Sm Egg). Polyclonal and Ag-specific Treg accumulation in the skin differed significantly between adjuvants. CFA and Alum led to robust Treg accumulation, with >50% of all skin CD4+ T cells being Foxp3+. In contrast, Tregs accumulated poorly in the Sm Egg–inflamed skin. Surprisingly, we found no evidence of inflammation-specific changes to the Treg gene program between adjuvant-inflamed skin types, suggesting a lack of selective recruitment or adaptation to the inflammatory milieu. Instead, Treg accumulation patterns were linked to differences in CD80/CD86 expression by APC and the regulation of CD25 expression, specifically in the inflamed skin. Inflammatory cues alone, without cognate Ag, differentially supported CD25 upregulation (CFA and Alum > Sm Egg). Only in inflammatory milieus that upregulated CD25 did the provision of Ag enhance local Treg proliferation. Reduced IL-33 in the Sm Egg–inflamed environment was shown to contribute to the failure to upregulate CD25. Thus, the magnitude of the Treg response in inflamed tissues is controlled at two interdependent levels: inflammatory signals that support the upregulation of the important Treg survival factor CD25 and Ag signals that drive local expansion.
Systems Analysis of the Complement-Induced Priming Phase of Liver Regeneration
Authors: Min Jun S. , DeAngelis Robert A. , Reis Edimara S. , Gupta Shakti , Maurya Mano R. , Evans Charles , Das Arun , Burant Charles , Lambris John D. , Subramaniam Shankar
Published: August 2016

Liver regeneration is a well-orchestrated process in the liver that allows mature hepatocytes to reenter the cell cycle to proliferate and replace lost or damaged cells. This process is often impaired in fatty or diseased livers, leading to cirrhosis and other deleterious phenotypes. Prior research has established the role of the complement system and its effector proteins in the progression of liver regeneration; however, a detailed mechanistic understanding of the involvement of complement in regeneration is yet to be established. In this study, we have examined the role of the complement system during the priming phase of liver regeneration through a systems level analysis using a combination of transcriptomic and metabolomic measurements. More specifically, we have performed partial hepatectomy on mice with genetic deficiency in C3, the major component of the complement cascade, and collected their livers at various time points. Based on our analysis, we show that the C3 cascade activates c-fos and promotes the TNF-α signaling pathway, which then activates acute-phase genes such as serum amyloid proteins and orosomucoids. The complement activation also regulates the efflux and the metabolism of cholesterol, an important metabolite for cell cycle and proliferation. Based on our systems level analysis, we provide an integrated model for the complement-induced priming phase of liver regeneration.
Loss of Trex1 in Dendritic Cells Is Sufficient To Trigger Systemic Autoimmunity
Authors: Peschke Katrin , Achleitner Martin , Frenzel Kathrin , Gerbaulet Alexander , Ada Servi Remzi , Zeller Nicolas , Lienenklaus Stefan , Lesche Mathias , Poulet Claire , Naumann Ronald , Dahl Andreas , Ravens Ursula , Günther Claudia , Müller Werner , Knobeloch Klaus-Peter , Prinz Marco , Roers Axel , Behrendt Rayk
Published: August 2016

Defects of the intracellular enzyme 3′ repair exonuclease 1 (Trex1) cause the rare autoimmune condition Aicardi–Goutières syndrome and are associated with systemic lupus erythematosus. Trex1−/− mice develop type I IFN–driven autoimmunity, resulting from activation of the cytoplasmic DNA sensor cyclic GMP–AMP synthase by a nucleic acid substrate of Trex1 that remains unknown. To identify cell types responsible for initiation of autoimmunity, we generated conditional Trex1 knockout mice. Loss of Trex1 in dendritic cells was sufficient to cause IFN release and autoimmunity, whereas Trex1-deficient keratinocytes and microglia produced IFN but did not induce inflammation. In contrast, B cells, cardiomyocytes, neurons, and astrocytes did not show any detectable response to the inactivation of Trex1. Thus, individual cell types differentially respond to the loss of Trex1, and Trex1 expression in dendritic cells is essential to prevent breakdown of self-tolerance ensuing from aberrant detection of endogenous DNA.
Expansion and Protection by a Virus-Specific NK Cell Subset Lacking Expression of the Inhibitory NKR-P1B Receptor during Murine Cytomegalovirus Infection
Authors: Rahim Mir Munir A. , Wight Andrew , Mahmoud Ahmad Bakur , Aguilar Oscar A. , Lee Seung-Hwan , Vidal Silvia M. , Carlyle James R. , Makrigiannis Andrew P.
Published: August 2016

NK cells play a major role in immune defense against human and murine CMV (MCMV) infection. Although the MCMV genome encodes for MHC class I–homologous decoy ligands for inhibitory NK cell receptors to evade detection, some mouse strains have evolved activating receptors, such as Ly49H, to recognize these ligands and initiate an immune response. In this study, we demonstrate that approximately half of the Ly49H-expressing (Ly49H+) NK cells in the spleen and liver of C57BL/6 mice also express the inhibitory NKR-P1B receptor. During MCMV infection, the NKR-P1B−Ly49H+ NK cell subset proliferates to constitute the bulk of the NK cell population. This NK cell subset also confers better protection against MCMV infection compared with the NKR-P1B+Ly49H+ subset. The two populations are composed of cells that differ in their surface expression of receptors such as Ly49C/I and NKG2A/C/E, as well as developmental markers, CD27 and CD11b, and the high-affinity IL-2R (CD25) following infection. Although the NKR-P1B+ NK cells can produce effector molecules such as IFNs and granzymes, their proliferation is inhibited during infection. A similar phenotype in MCMV-infected Clr-b–deficient mice, which lack the ligand for NKR-P1B, suggests the involvement of ligands other than the host Clr-b. Most interestingly, genetic deficiency of the NKR-P1B, but not Clr-b, results in accelerated virus clearance and recovery from MCMV infection. This study is particularly significant because the mouse NKR-P1B:Clr-b receptor:ligand system represents the closest homolog of the human NKR-P1A:LLT1 system and may have a direct relevance to human CMV infection.
Diversified Anchoring Features the Peptide Presentation of DLA-88*50801: First Structural Insight into Domestic Dog MHC Class I
Authors: Xiao Jin , Xiang Wangzhen , Chai Yan , Haywood Joel , Qi Jianxun , Ba Limin , Qi Peng , Wang Ming , Liu Jun , Gao George F.
Published: August 2016

Canines represent a crucial animal model for studying human diseases and organ transplantation, as well as the evolution of domestic animals. MHCs, with a central role in cellular immunity, are commonly used in the study of dog population genetics and genome evolution. However, the molecular basis for the peptide presentation of dog MHC remains largely unknown. In this study, peptide presentation by canine MHC class I DLA-88*50801 was structurally determined, revealing diversified anchoring modes of the binding peptides. Flexible and large pockets composed of both hydrophobic and hydrophilic residues can accommodate pathogen-derived peptides with diverse anchor residues, as confirmed by thermostability measurements. Furthermore, DLA-88*50801 contains an unusual α2 helix with a large coil in the TCR contact region. These results further our understanding of canine T cell immunity through peptide presentation of MHC class I and shed light on the molecular basis for vaccine development for canine infectious diseases, for example, canine distemper virus.
A Logistics Barometer for South Africa: Towards sustainable freight mobility
Authors: Havenga Jan H. , De Bod Anneke , Simpson Zane P. , Viljoen Nadia , King David
Published: August 2016

Background: South Africa has a disproportionately high freight transport demand owing to industrial development far from ports, low domestic beneficiation and improper modal use. Historical freight transport policy supported primary economic development, failing to preempt the changing economic structure and the resulting freight transport needs, resulting in excessive transport costs and externalities.Objectives: To share the macroeconomic freight transport challenges revealed by South Africa’s Logistics Barometer, and to identify key interventions to address these.Method: Freight flows are modelled by disaggregating the national input–output model into 83 commodity groupings and 372 geographical areas, culminating in a 30-year forecast at 5-year intervals for three scenarios, followed by distance-decay gravity modelling to determine freight flows. Logistics costs are calculated by relating these flows to the costs of fulfilling associated logistic functions.Results: Long-distance transport remains the largest general freight typology and is, due to inefficient macro logistics design, extremely costly, both in terms of intrinsic and extrinsic costs.Conclusion: South Africa’s freight task will grow 2.5-fold by 2043. Logistics and externality costs are already untenable at current levels. The development of domestic intermodal solutions will support the drive towards sustainable freight mobility.
In search for a perfect shape of polyhedra: Buffon transformation
Authors: Schreiber Veronika , Veselov Alexander P. , Ward Joseph P.
Published: August 2016

For an arbitrary polygon generate a new one by joining the centres of consecutive edges. Iteration of this procedure leads to a shape which is affine equivalent to a regular polygon. This regularisation effect is usually ascribed to Count Buffon (1707–1788). We discuss a natural analogue of this procedure for 3-dimensional polyhedra, which leads to a new notion of affine

B

-regular polyhedra. The main result is the proof of existence of star-shaped affine $$-regular polyhedra with prescribed combinatorial structure, under partial symmetry and simpliciality assumptions. The proof is based on deep results from spectral graph theory due to Colin de Verdière and Lovász.
Commission Internationale de l'Enseignement Mathématique. ICMI Study 23: Primary Mathematics Study on Whole Numbers
Authors: Bartolini Bussi Maria G. , Sun Xuhua
Published: August 2016

In this paper, we report on the progress of the first ICMI Study directing attention on primary level mathematics, focused on whole number arithmetic. We describe the background and the planning of the study, the realization of the study conference and the preparation of the volume emanating from discussions at the conference, due for publication at the end of 2016.
Ergodicity and indistinguishability in percolation theory
Authors: Martineau Sébastien
Published: August 2016

This paper explores the link between the ergodicity of the cluster equivalence relation restricted to its infinite locus and the indistinguishability of infinite clusters. It is an important element of the dictionary connecting orbit equivalence and percolation theory. This note starts with a short exposition of some standard material of these theories. Then, the classical correspondence between ergodicity and indistinguishability is presented. Finally, we introduce a notion of strong indistinguishability that corresponds to strong ergodicity, and obtain that this strong indistinguishability holds in the Bernoulli case. We also define an invariant percolation that is not insertion-tolerant, satises the Indistinguishability Property and does not satisfy the Strong Indistinguishability Property.
The lower central series of a right-angled Artin group
Authors: Wade Richard D.
Published: August 2016

We give a description of Droms, Duchamp and Krob’s extension of Magnus’ approach to the lower central series of the free group to right-angled Artin groups. We also describe how Lalonde’s extension of Lyndon words to the partially commutative setting gives a simple algorithm to find a basis for consecutive quotients of the lower central series of a RAAG.
Lamplighters, metabelian groups, and horocyclic products
Authors: Amchislavska Margarita , Riley Timothy R.
Published: August 2016

Bartholdi, Neuhauser and Woess proved that a family of metabelian groups including lamplighters have a striking geometric manifestation as 1-skeleta of horocyclic products of trees. The purpose of this article is to give an elementary account of this result, to widen the family addressed to include the infinite valence case (for instance

\mathbb Z \wr \mathbb Z

), and to make the translation between the algebraic and geometric descriptions explicit.

In the rank-2 case, where the groups concerned include a celebrated example of Baumslag and Remeslennikov, we give the translation by means of a combinatorial ‘lamplighter description’. This elucidates our proof in the general case which proceeds by manipulating polynomials.

Additionally, we show that the Cayley 2-complex of a suitable presentation of Baumslag and Remeslennikov’s example is a horocyclic product of three trees.
Pseudoholomorphic simple Harnack curves
Authors: Brugallé Erwan
Published: August 2016

We give a new proof of Mikhalkin’s Theorem on the topological classification of simple Harnack curves, which in particular extends Mikhalkin’s result to real pseudoholomorphic curves.
Changes in the width of the tropical belt due to simple radiative forcing changes in the GeoMIP simulations
Authors: Davis Nicholas A. , Seidel Dian J. , Birner Thomas , Davis Sean M. , Tilmes Simone
Published: August 2016

Abstract. Model simulations of future climates predict a poleward expansion of subtropical arid climates at the edges of Earth's tropical belt, which would have significant environmental and societal impacts. This expansion may be related to the poleward shift of the Hadley cell edges, where subsidence stabilizes the atmosphere and suppresses precipitation. Understanding the primary drivers of tropical expansion is hampered by the myriad forcing agents in most model projections of future climate. While many previous studies have examined the response of idealized models to simplified climate forcings and the response of comprehensive climate models to more complex climate forcings, few have examined how comprehensive climate models respond to simplified climate forcings. To shed light on robust processes associated with tropical expansion, here we examine how the tropical belt width, as measured by the Hadley cell edges, responds to simplified forcings in the Geoengineering Model Intercomparison Project (GeoMIP). The tropical belt expands in response to a quadrupling of atmospheric carbon dioxide concentrations and contracts in response to a reduction in the solar constant, with a range of a factor of 3 in the response among nine models. Models with more surface warming and an overall stronger temperature response to quadrupled carbon dioxide exhibit greater tropical expansion, a robust result in spite of inter-model differences in the mean Hadley cell width, parameterizations, and numerical schemes. Under a scenario where the solar constant is reduced to offset an instantaneous quadrupling of carbon dioxide, the Hadley cells remain at their preindustrial width, despite the residual stratospheric cooling associated with elevated carbon dioxide levels. Quadrupled carbon dioxide produces greater tropical belt expansion in the Southern Hemisphere than in the Northern Hemisphere. This expansion is strongest in austral summer and autumn. Ozone depletion has been argued to cause this pattern of changes in observations and model experiments, but the results here indicate that seasonally and hemispherically asymmetric tropical expansion can be a basic response of the general circulation to climate forcings.
The possible contribution of the periodic emissions from farmers' activities
in the North China Plain to atmospheric water-soluble ions in Beijing
Authors: Liu Pengfei , Zhang Chenglong , Mu Yujing , Liu Chengtang , Xue Chaoyang , Ye Can , Liu Junfeng , Zhang Yuanyuan , Zhang Hongxing
Published: August 2016

Abstract. The North China Plain (NCP), which includes Beijing, is currently suffering from severe haze events due to a high pollution level of PM2.5. To mitigate the serious pollution problem, identification of the sources of PM2.5 is urgently needed for the effective control measures. Daily samples of PM2.5 were collected in Beijing city and in a rural area in Baoding, Hebei Province through the year of 2014, and the seasonal variation of water-soluble ions (WSIs) in PM2.5 was comprehensively analysed to determine their possible sources. The results indicated that the periodic emissions from farmers' activities made a significant contribution to the atmospheric WSIs in Beijing. The relatively high concentration of K+ in winter and autumn at the two sampling sites confirmed that crop straw burning contributed to atmospheric K+ in Beijing. The remarkable elevation of Cl− at the two sampling sites as well as the evident increase of the Cl− ∕ K+ ratio and the Cl− proportion in WSIs during the winter in Beijing could be ascribed to coal combustion for heating by farmers. The unusually high ratio of Cl− to Na+ in summer, the obviously high concentrations of Cl− in the rural sampling site and the elevation of Cl− proportion in WSIs in Beijing during the maize fertilization could be explained by the use of the prevailing fertilizer of NH4Cl in the vast area of NCP. The abnormally high concentrations of Ca2+ at the two sampling sites and the elevation of Ca2+ proportion during the period of the maize harvest and soil ploughing in Beijing provided convincing evidence that the intensive agricultural activities in autumn contributed to the regional mineral dust. The most serious pollution episodes in autumn were coincident with significant elevation of Ca2+, indicating that the mineral dust emission from the harvest and soil ploughing not only increased the atmospheric concentrations of the primary pollutants, but also greatly accelerated formation of sulfate and nitrate through heterogeneous reactions of NO2 and SO2 on the mineral dust. The backward trajectories also indicated that the highest concentrations of WSIs usually occurred in the air parcel from southwest–south regions, which have a high density of farmers. In addition, the values of nitrogen oxidation ratio (NOR) and the sulfur oxidation ratio (SOR) were found to be much greater under haze days than under non-haze days, implying that formation of sulfate and nitrate was greatly accelerated through heterogeneous or multiphase reactions of NO2 and SO2 on PM2.5.
Characteristics of vertical air motion in isolated convective
clouds
Authors: Yang Jing , Wang Zhien , Heymsfield Andrew J. , French Jeffrey R.
Published: August 2016

Abstract. The vertical velocity and air mass flux in isolated convective clouds are statistically analyzed using aircraft in situ data collected from three field campaigns: High-Plains Cumulus (HiCu) conducted over the midlatitude High Plains, COnvective Precipitation Experiment (COPE) conducted in a midlatitude coastal area, and Ice in Clouds Experiment-Tropical (ICE-T) conducted over a tropical ocean. The results show that small-scale updrafts and downdrafts (<  500 m in diameter) are frequently observed in the three field campaigns, and they make important contributions to the total air mass flux. The probability density functions (PDFs) and profiles of the observed vertical velocity are provided. The PDFs are exponentially distributed. The updrafts generally strengthen with height. Relatively strong updrafts (>  20 m s−1) were sampled in COPE and ICE-T. The observed downdrafts are stronger in HiCu and COPE than in ICE-T. The PDFs of the air mass flux are exponentially distributed as well. The observed maximum air mass flux in updrafts is of the order 104 kg m−1 s−1. The observed air mass flux in the downdrafts is typically a few times smaller in magnitude than that in the updrafts. Since this study only deals with isolated convective clouds, and there are many limitations and sampling issues in aircraft in situ measurements, more observations are needed to better explore the vertical air motion in convective clouds.
The contribution of soil biogenic NO and HONO emissions from a managed
hyperarid ecosystem to the regional NOx emissions during growing
season
Authors: Mamtimin Buhalqem , Meixner Franz X. , Behrendt Thomas , Badawy Moawad , Wagner Thomas
Published: August 2016

Abstract. A study was carried out to understand the contributions of soil biogenic NO emissions from managed (fertilized and irrigated) hyperarid ecosystems in NW China to the regional NOx emissions during the growing season. Soil biogenic net potential NO fluxes were quantified by laboratory incubation of soil samples from the three dominating ecosystems (desert, cotton, and grape fields). Regional biogenic NO emissions were calculated bottom-up hourly for the entire growing season (April–September 2010) by considering corresponding land use, hourly data of soil temperature, gravimetric soil moisture, and fertilizer enhancement factors. The regional HONO emissions were estimated using the ratio of the optimum condition ((FN,opt(HONO) to FN,opt (NO)). Regional anthropogenic NOx emissions were calculated bottom-up from annual statistical data provided by regional and local government bureaus which have been downscaled to monthly value. Regional top-down emission estimates of NOx were derived on the monthly basis from satellite observations (OMI) of tropospheric vertical NO2 column densities and prescribed values of the tropospheric NOx lifetime. In order to compare the top-down and bottom-up emission estimates, all emission estimates were expressed in terms of mass of atomic nitrogen. Consequently, monthly top-down NOx emissions (total) were compared with monthly bottom-up NOx emissions (biogenic + anthropogenic) for the time of the satellite overpass (around 13:00 LT) with the consideration of the diurnal cycle of bottom-up estimates. Annual variation in total Tohsun Oasis NOx emissions is characterized by a strong peak in winter (December–February) and a secondary peak in summer (June–August). During summer, soil biogenic emissions were from equal to double that of related anthropogenic emissions, and grape soils were the main contributor to soil biogenic emissions, followed by cotton soils, while emissions from the desert were negligible. The top-down and bottom-up emission estimates were shown to be useful methods to estimate the monthly/seasonal cycle of the total regional NOx emissions. The resulting total NOx emissions show a strong peak in winter and a secondary peak in summer, and the second maximum in summer was only found if the soil emissions were taken into account, which provides confidence in both completely independent methods. Despite the regional character of these findings, particularly the second maximum in summer provides substantial evidence to hypothesize that biogenic emissions from soils of managed drylands (irrigated and fertilized) in the growing period may be much more important contributors to regional NOx budgets of dryland regions than thought before.
Seasonal and inter-annual variability of lower stratospheric age of air spectra
Authors: Ploeger Felix , Birner Thomas
Published: August 2016

Abstract. Trace gas transport in the lower stratosphere is investigated by analysing seasonal and inter-annual variations of the age of air spectrum – the probability distribution of stratospheric transit times. Age spectra are obtained using the Chemical Lagrangian Model of the Stratosphere (CLaMS) driven by ERA-Interim winds and total diabatic heating rates, and using a time-evolving boundary-impulse-response (BIER) method based on multiple tracer pulses. Seasonal age spectra show large deviations from an idealized stationary uni-modal shape. Multiple modes emerge in the spectrum throughout the stratosphere, strongest at high latitudes, caused by the interplay of seasonally varying tropical upward mass flux, stratospheric transport barriers and recirculation. Inter-annual variations in transport (e.g. quasi-biennial oscillation) cause significant modulations of the age spectrum shape. In fact, one particular QBO phase may determine the spectrum's mode during the following 2–3 years. Interpretation of the age spectrum in terms of transport contributions due to the residual circulation and mixing is generally not straightforward. It turns out that advection by the residual circulation represents the dominant pathway in the deep tropics and in the winter hemisphere extratropics above 500 K, controlling the modal age in these regions. In contrast, in the summer hemisphere, particularly in the lowermost stratosphere, mixing represents the most probable pathway controlling the modal age.