Interactions

There are currently more than 100 million single nucleotide polymorphisms (SNPs), which are the most frequent and basic type of genetic variation. The availability of over 110,000 three-dimensional protein structures allows the structural context of many SNPs to be examined in atomic detail. Interfaces are essential sites for protein function and adaptation, and key in a majority of biological processes. A computational framework, ProIntVar, was developed for mapping SNPs onto the structures to allow the features of variation at domain-domain and domain-ligand interfaces to be studied. ProIntVar allows the systematic analysis of genetic variation in protein structure interaction surfaces by integrating structural and sequencing data from several biological databases and resources. Protein domains and variants were analysed in the context of structural clusters (SCs) and functional families (FunFams), which are derived from structurally and functionally related protein domains in Superfamilies classified in CATH (Class, Architecture, Topology, Homologous Superfamily). Multiple structural alignments were generated by STAMP for each CATH SC and FunFam, using an improved protocol that leads to improvement of the structural superimposition and resulting structure-based alignments. The structural alignments were extended with similar protein sequences by HMM-based xix sequence search. These sequences are believed to be structurally/functionally homologous and thus a rich source of novel insight into the structural context and potential consequences of a vast number of genetic variants. The characterisation of both disease-associated and non-disease germline variants, as well as somatic variation, was performed. The analysis of non-synonymous SNPs (nsSNPs) was stratified by annotation and potential consequence and focused particularly on domain-domain and domain-ligand interaction interfaces. Domain interactions were screened and further classified by mode of interaction as clustered by iRMSD (interaction root-mean-square deviation). The results corroborate previous observations that pathogenic mutations are enriched at key sites, such as structurally conserved domain-ligands interfaces and the protein core. Examination of genetic variation at such hot-spots in the context of domain families helps to infer which variants are more likely to affect protein activity and function in a broader evolutionary sense. The most drastic features shared by pathogenic variants were identified to prioritise the analysis of nsSNPs currently thought to be neutral, but potentially disruptive.

Trichloroacetic acid (TCA; CCl 3 COOH) is a phytotoxic chemical. Although TCA salts and derivatives were once deployed as herbicides against perennial grasses and weeds, their use has since been banned because of their indiscriminate herbicidal effects on woody plant species. However, TCA can also be formed in the atmosphere. For instance, high-volatile C 2 -chlorohydrocarbons tetrachloroethene (TECE, C 2 Cl 4 ) and 1,1,1-trichloroethane (TCE, CCl 3 CH 3 ) can react to TCA and other substances under oxidative conditions here. Owing to further industrialisation of Southeast Asia, South Africa and South America, a rise can be expected in the use of TECE as solvents in the metal and textile industries of these regions in the southern hemisphere (SH). The increasing emissions of this substanceFtogether with the rise in the atmospheric oxidation potential caused by urban activities, slash and burn agriculture and forest fires in the SHFwill result in the increased input/formation of TCA in the vegetation located on the lee side of these emission sources. By means of biomonitoring studies, inputs/formation of TCA related to the climatic conditions were detected at various locations in South America, Africa, and Europe.

Human red blood cells (RBC) are highly differentiated cells that have lost all organelles and most intracellular machineries during their maturation process. RBC are fundamental for the nearly all basic physiologic dynamics and they are key cells in the body's respiratory system by being responsible for the oxygen transport to all cells and tissues, and delivery of carbon dioxide to the lungs. With their flexible structure RBC are capable to deform in order to travel through all blood vessels including very small capillaries. Throughout their in average 120 days lifespan, human RBC travel in the bloodstream and come in contact with a broad range of different cell types. In fact, RBC are able to interact and communicate with endothelial cells (ECs), platelets, macrophages, and bacteria. Additionally, they are involved in the maintenance of thrombosis and hemostasis and play an important role in the immune response against pathogens. To clarify the mechanisms of interaction of RBC and these other cells both in health and disease as well as to highlight the role of important key players, we focused our interest on RBC membrane components such as ion channels, proteins, and phospholipids.

Flow Meter Based on Freely Suspended Smectic Liquid Crystal Films 1 ADAM GREEN, None, ZHIYUAN QI, CHEOL PARK, MATTHEW GLASER, JOSEPH MACLENNAN, NOEL CLARK, Soft Materials Reseach Center, Univeristy of Colorado, Boulder, CO 80309 -We present the realization of a idealized 2D hydrodynamic system coupled to air-flow, and show that freely suspended films (FSF) of smectic liquid crystals can be used as a novel flow-meter. Freely-suspended films of liquid crystals are one of the closest physical realizations of an idealized 2D fluid. The velocity of air-flow above a film suspended above a channel can be inferred by studying the velocity profile of the smectic film. This velocity profile can be measured using digital video microscopy to track the inclusions present in the moving film. The velocity profile is then fitted to the coupled 2D solutions of an embedded fluid in air, and the velocity of the air can then be extracted. This flow meter serves as a demonstration of a robust test-bed for further exploration of 2D hydrodynamics.

S.A -We generate islands, circular regions of greater thickness than the surrounding film area, on freely-suspended SmC* films by applying air jets to the film. The c-director field (the projection of the molecular long axis onto the plane of the film) is strongly tangential at the edges of the islands, leading to the formation of s = +1 topological defects inside the islands and s = -1 defects nearby on the background film. Islands interact via these topological defects, with a short-range repulsion and a long-range dipolar attraction governing their stability and leading to their organization in chain-like structures with an equilibrium island separation. We use optical tweezers to measure the force between a pair of islands as a function of their separation. As we vary the enantiomeric excess and hence the polarization of the liquid crystal, the force scales as the polarization squared and the shape of the force curve changes. Simulations based on a simple model of film elasticity and polarization explain our experimental results fairly well.

The relationship between Fe uptake and Mo availability and its possible correlation with reduction of nitrates has been studied. Lucerne plants (Medicago sativa L.) were grown in hydroponic cultures in acid‐washed quartz sand and deionized water. The greenhouse environmental temperature ranged from 22–25°C. The pots were exposed to a light intensity of 8000 lux for 16 hours and to a

Louis Laloy a été critique musical, secretaire general de l'Opera de Paris et professeur d'esthetique chinoise a l'Institut des hautes etudes chinoises et d'histoire de la musique au Conservatoire supérieur de Paris. Son amitié avec Claude Debussy est a l'origine d'un veritable échange intellectuel et musical qui transparaît dans les coincidences existant entre la piece pour piano Et la lune descende sur le temple qui fut et une conférence donnée par Louis Laloy en 1906

Island environments have specific biotic and abiotic characteristics, as fragility, limitation of natural resources, geographic isolation, and fragmentation are determining factors that directly affect these areas. Thus, it is relevant to understand the natural evolution of the landscape in the islands, considering the anthropic actions and climate changes in the transformation of vegetation cover, as a means of time series and study of satellite images. This paper aims to analyze the dynamics of the landscape (changes in vegetation cover) of the Fernando de Noronha Archipelago concerning urban development, and other anthropic activities that occurred between 1999 and 2018, through remote sensing images, to establish comparisons with the Island Management Plans that were elaborated in the years of 2005 and 2017. Also, this study intends to raise elements to assist in the spatial management of the Archipelago and to establish Public Conservation Policies for Fernando de Noronha and o...

: Under the National Environmental Policy Act (NEPA), 42 U.S. Code 4321 et seq., Council on Environmental Quality (CEQ) implementing regulations, 40 Code of Federal Regulations (CFR) 1500- 1508, and 32 CFR Part 989, Environmental Impact Analysis Process, the U.S. Air Force (Air Force) conducted an assessment of the potential environmental consequences associated with implementing security and safety upgrades to Entry Control Facilities (ECFs) at Vandenberg Air Force Base (AFB). The Environmental Assessment (EA), incorporated by reference to this finding, considers all potential impacts of the Proposed Action and No-Action Alternative, both as a solitary action, and cumulatively in conjunction with other projects at Vandenberg AFB. The EA analyzes the potential environmental consequences of construction at five of Vandenberg AFB's ECFs, and provides general environmental protection criteria and guidelines for proposed construction and demolition activities that would prevent adve...

Sustainability in (Inter)Action provides a forum for innovative thought, design, and research in the area of interaction design and environmental sustainability. The column explores how HCI can contribute to the complex and interdisciplinary efforts to address sustainability challenges. Elaine M. Huang, Editor

The article analyzes the biographical case of cancer with problematized attitude to traditional medicine. The author examines the biographical choices of the informant and the problem of not following the medicalist treatment strategy. Optics using analytic methods and social theory, the author seeks to show that living biographer’s disease and agree with the diagnosis of a life inextricably linked with the social relations within which these terms aventureuse, namely in the framework of relations “doctor-patient”. The analysis of this social dyad using the methods of anthropology and narratology brings us closer to the understanding of disease as a phenomenon mediated by the cultural codes of society, the dominant model of which is the biomedical paradigm of studying the “diseased body”.

The relative importance of multiple vectors to the initial establishment, spread and population dynamics of invasive species remains poorly understood. This study used molecular methods to clarify the roles of commercial shipping and recreational boating in the invasion by the cosmopolitan tunicate, Botryllus schlosseri. We evaluated (i) single vs. multiple introduction scenarios, (ii) the relative importance of shipping and boating to primary introductions, (iii) the interaction between these vectors for spread (i.e. the presence of a shipping‐boating network) and (iv) the role of boating in determining population similarity. Tunicates were sampled from 26 populations along the Nova Scotia, Canada, coast that were exposed to either shipping (i.e. ports) or boating (i.e. marinas) activities. A total of 874 individuals (c. 30 per population) from five ports and 21 marinas was collected and analysed using both mitochondrial cytochrome c oxidase subunit I gene (COI) and 10 nuclear micr...

A atividade turistica pode gerar impactos positivos e negativos nas localidades onde se desenvolve e esses impactos irao refletir nas praticas culturais da comunidade receptora. Neste sentido, o presente artigo teve como objetivo estudar os impactos do turismo em uma aldeia indigena denominada Sao Francisco. A referida Aldeia fica localizada no municipio de Baia da Traicao, uma regiao bastante visitada, principalmente pela presenca de indios Potiguaras. Para a realizacao do estudo, adotamos a pesquisa bibliografica e documental, entrevista e observacao. Os resultados mostram que o turismo que se desenvolve na regiao e organizado pelos proprios habitantes e por isso, de forma geral, os entrevistados consideram que seus modos de vida nao foram afetados pela presenca dos visitantes. Na verdade, segundo os inquiridos, o turismo funciona como uma renda extra atraves da venda de artesanato e outros produtos locais e estimula a autoestima local, uma vez que a maioria dos turistas busca viv...

The complex flow features that arise from the impact of a shock wave on a concave cavity are determined by means of high-speed video photography. Besides additional information on features that have previously been encountered in specific studies, such as those relating to shock wave reflection from a cylindrical wall and those associated with shock wave focusing, a number of new features become apparent when the interaction is studied over longer times using time-resolved imaging. The most notable of these new features occurs when two strong shear layers meet that have been generated earlier in the motion. Two jets can be formed, one facing forward and the other backward, with the first one folding back on itself. The shear layers themselves develop a Kelvin–Helmholtz instability which can be triggered by interaction with weak shear layers developed earlier in the motion. Movies are available with the online version of the paper.

Background & Aims: Diet contributes to colorectal cancer development and may be potentially modified. We wanted to identify the biological mechanisms underlying colorectal carcinogenesis by assessment of diet-gene interactions. The polymorphisms IL10 C-592A (rs1800872), C-rs3024505-T, IL1b C-3737T (rs4848306), G-1464C (rs1143623), T-31C (rs1143627) and PTGS2 (encoding COX-2) A-1195G (rs689466), G-765C (rs20417), and T8473C (rs5275) were assessed in relation to risk of colorectal cancer (CRC) and interaction with diet (red meat, fish, fibre, cereals, fruit and vegetables) and lifestyle (non-steroid-anti-inflammatory drug use and smoking status) was assessed in a nested case-cohort study of nine hundred and seventy CRC cases and 1789 randomly selected participants from a prospective study of 57,053 persons. Results: IL1b C-3737T, G-1464C and PTGS2 T8473C variant genotypes were associated with risk of CRC compared to the homozygous wildtype genotype (IRR=0.81, 95%CI: 0.68-0.97, p=0.02, and IRR=1.22, 95%CI: 1.04-1.44, p=0.02, IRR=0.75, 95%CI: 0.57-0.99, p=0.04, respectively). Interactions were found between diet and IL10 rs3024505 (P-value for interaction (P int ); meat=0.04, fish=0.007, fibre=0.0008, vegetables=0.0005), C-592A (P int ; fibre=0.025), IL1b C-3737T (P int ; vegetables=0.030, NSAID use=0.040) and PTGS2 genotypes G-765C (P int ; meat=0.006, fibre=0.0003, fruit 0.004), and T8473C (P int ; meat 0.049, fruit=0.03) and A-1195G (P int ; meat 0.038, fibre 0.040, fruit=0.059, vegetables=0.025, and current smoking=0.046). Genetically determined low COX-2 and high IL-1β activity were associated with increased risk of CRC in this northern Caucasian cohort. Furthermore, interactions were found between IL10, IL1b, and PTGS2 and diet and lifestyle factors in relation to CRC. The present study demonstrates that gene-environment interactions may identify genes and environmental factors involved in colorectal carcinogenesis.

The energy flow in various bivalve species (Macoma balthica, Mya arenaria, Cerastoderma edule, Mytilus edulis and Crassostrea gigas) in different habitats (intertidal, subtidal and offshore areas) of Dutch coastal waters was analysed by comparing growth observations in the field with model simulations by means of the Dynamic Energy Budget (DEB) theory. The reconstruction of the seasonal food conditions suggested that with respect to food consumption, M. balthica and C. edule are the most successful species, followed by M. arenaria, and M. edulis and C. gigas. Positive growth was correlated with the beginning of the spring bloom in primary production and food limitation between species was lowest during this period. After the spring bloom, severe food limitation during the summer period was found. As a result, negative body growth occurred during most of year. DEB model simulations both on an annual and a seasonal basis also showed that, at the prevailing water temperatures, growth of the different species was not maximal. It remains uncertain whether the suboptimal food conditions were the consequence of food limitation or also of reduced filtration efficiency due to the high sediment load in the water.

Using a panel data set of 14 EU countries from 1970 to 2012, we study the type of monetary and fiscal policies of both authorities, and assess how they are influenced by certain economic variables and events (the Maastricht Treaty, the Stability and Growth Pact, the Euro and crises). Results show that inflation has a significant impact on monetary policy, and that governments raise their primary balances when facing increases in debt. Another goal is to characterise the type of interactions established between central banks and national governments, i.e. if their policies complement one another, or whether there is a more dominant one. Still, our results point to the lack of evidence concerning central banks' response to fiscal policy.

La diferenciación entre C. borealis y C. diomedea habría ocurrido en alopatría por contracción de su área de distribución durante el Pleistoceno. Calonectris edwardsii está más emparentada con C. diomedea a partir de la cual se habría diferenciado 1 . Se ha detectado flujo reciente de genes entre C. borealis y C. diomedea, alrededor del 3% de C. diomedea a C. borealis y del 10% de C. borealis a C. diomedea 1 . C. borealis es en promedio un 46% mayor en masa corporal que C. diomedea y su pico es más robusto. El cuello muestra menos contraste con la cabeza y el dorso en borealis, dando la sensación de ser más estrecho que en diomedea. El plumaje de C. borealis se muestra en general más oscuro y contrastado, en particular las partes inferiores, donde el reborde oscuro de las alas se adentra más hacia el interior y define un margen mucho más resaltado que en C. diomedea. En C. borealis, el área blanca de la zona inferior de las alas se restringe a las plumas cobertoras, dando una forma redondeada a dicho área. Por el contrario, en C. diomedea la zona proximal de las primarias más externas es casi blanca, lo que crea un efecto de panel blanco angulado en forma de cuña, no sólo formado por la cobertoras, como en C. borealis, sino también por las primarias (Cramp y Simmons, 1977;. La pardela cenicienta es un ave marina típica, con alas largas y delgadas adaptadas para aprovechar al máximo los frecuentes vientos que soplan sobre la superficie marina . Su estrategia de vuelo se basa en largas secuencias de planeo combinadas con secuencias de vuelo activo batiendo las alas, en las que el consumo energético aumenta notablemente. Siempre a escasa altura sobre el agua, este patrón de vuelo varía en función de la velocidad del viento. De esta forma, con el aumento de la velocidad del viento disminuye la frecuencia y duración de los intervalos en que baten las alas y aumenta la distancia a la superficie . La pardela atlántica es la mayor de las pardelas que pueden observarse en aguas europeas, con una envergadura media de 126'30 ± 5'33 cm, n=127 y una masa corporal media de 785'80 ± 86'98 g, n= 771; datos propios). La morfología de esta ave marina es robusta, con cabeza redondeada, alas largas y cola corta. De coloración apagada, presenta colores pardo grisáceos en las zonas superiores, que llegan hasta la zona inferior del pico, mientras que por debajo son de color blanco prácticamente en su totalidad, salvo el borde externo de las alas, que es oscuro. Las plumas supracobertoras caudales están manchadas de blanco, formando muchas veces una estrecha banda que separa la cola del obispillo. El pico, fuerte y largo, es amarillento con el extremo negruzco, y presenta unas narinas muy patentes. Las patas son de tonos rosados. Algunos casos de anomalías pigmentarias en el plumaje han sido publicados. Bried et al. ( ) reportan 3 casos de pardelas con coloración aberrante, una de ellas melánica, en las Islas Canarias, además de un caso de melanismo en Azores. Los valores de hematocrito, leucocitos y trombocitos no difieren entre sexos. Hay una correlación positiva entre el número de leucocitos y condición física . En la Tabla 1 se presentan datos biométricos de varias poblaciones reproductoras de ambas subespecies de pardela cenicienta.

The African continent has been subjected to several changes in its environmental conditions in the past. These changes have affected vegetation patterns, soil development and earth-surface processes. Repeated change has caused the development of a complex pattern of inherited features in the present-day landscape that regulate its susceptibility towards modern change in environmental conditions. Since the late Pleistocene and early Holocene, human interference in ecodynamics has increased dramatically. Humans have been altering the environment since they first controlled fire and invented agriculture. However, the exponential growth of population in the last 100 years has brought with it an accelerated rate of landscape degradation. The superimposition of anthropogenous sources of interference and climatic factors has often changed the type and intensity of earth-surface processes. This results in an imbalance and often triggers an array of self-reinforcing processes. These processes operate on different spatial scales and in different time frames and are discussed in chapter 2. In many areas of Africa, intensified use of land has induced serious soil erosion. Particularly in the semi-arid tropical and subtropical zones of Africa, soil-erosion processes are supported by the variable nature of rainfalls, the strong seasonal contrasts in the availability of moisture and the poor vegetation cover and soils and sediments, which are characterised by a high level of erodibility. Chapter 3 provides an attempt to summarise some of the processes and impacts which are associated with soil erosion in Africa. Extreme events played and play an important role in the African morphodynamic system and may pose a threat to humans. The spatial and temporal distribution of extreme events and factors which determine the magnitude, frequency and the impact of such events are discussed in chapter 4. The increasing demand for arable land has resulted in the enlargement of those areas affected by biomass burning. Chapter 5 provides an overview of the impact of savanna fires on the vegetation and the emission of greenhouse gases into the atmosphere. The objective of this paper is to present a synthesis of the recent research on the influence of human interference on earth-surface processes and the differing reaction paths in the African landscapes. In the course of the Cenozoic period, the African continent experienced several phases characterised by very different environmental conditions. On a time scale of 10 6 to 10 8 years, www.intechopen.com

Excess molar volumes, at 25 • C and atmospheric pressure for methylbutyl amine + n-hexane; + cyclohexane; + n-octane; n-decane; + n-dodecane; + n-tetradecane, or + n-hexadecane systems are reported from densities measured with a vibrating-tube densimeter. The excess functions, molar enthalpy, and volume, for linear secondary amine + n-alkane systems are discussed in terms of interactional and structural effects. In addition, these solutions, which include amines from dimethyl to dioctylamine, are studied in the framework of the ERAS model. The corresponding ERAS parameters are reported. The agreement between experimental data and ERAS results is good for excess enthalpies, excess Gibbs energies, and excess molar volumes. The larger discrepancies are found for the excess volumes when strong free-volume effects are present in the investigated mixtures. The variation with temperature of the thermodynamic properties is well described by ERAS.

Densities, ρ, and speeds of sound, u, of 2-heptanone + aniline + N -methylaniline or + pyridine systems have been measured at (293.15, 298.15 and 303.15) K and atmospheric pressure using a vibrating tube densimeter and sound analyzer. The ρ and u values were used to calculate excess molar volumes, V E , and the excess functions at 298.15 K for the speed of sound, u E , the thermal expansion coefficient, α E p , and for the isentropic compressibility, κ E S . V E and κ E S are both negative and increase in the sequence: aniline < N -methylaniline < pyridine. In contrast, u E is positive and changes in the opposite way. The data suggest the existence of interactions between unlike molecules, which are much weaker in the pyridine solution. Aromatic amine-alkanone interactions are stronger in mixtures with acetone. The linear dependence of Rao's constant with concentration reveals that there is no complex formation in the investigated systems.

Liquid-liquid equilibrium (LLE) temperatures have been determined for benzaldehyde + CH 3 (CH 2 ) n CH 3 (n = 8, 10,12,14) mixtures by means of the opalescence method using a laser scattering technique. All the solutions show an upper critical solution temperature (UCST), which increases almost linearly with n. Benzaldehyde + benzene, or + alkyl-benzene, or + alkane mixtures have been treated in terms of the group contribution model DISQUAC. The corresponding interaction parameters for the contacts formyl/aromatic, formyl/aliphatic, formyl/c-CH 2 are reported. The former are entirely dispersive; the remainder contacts are characterized by both dispersive and quasichemical interaction parameters. The model correctly describes excess molar enthalpies, H E m , and the phase equilibrium diagrams, liquid-liquid, vapour-liquid (VLE) and solid-liquid (SLE) of the investigated solutions, over a wide range of temperature using the same set of interaction parameters. Complex phase diagrams including simultaneous LLE and SLE are also well represented by DISQUAC. It is shown that interactions between benzaldehyde and an aromatic hydrocarbon are mainly dispersive, and that those between benzaldehyde molecules in alkane solutions are of dipolar type.

Linear alkanone or cyclohexanone + aromatic hydrocarbon mixtures have been studied using DIS-QUAC and the Kirkwood-Buff formalism. The aromatic compounds considered are: benzene, toluene, 1,4-dimethylbenzene, 1,2,4-trimethylbenzene and ethylbenzene. Vapour-liquid equilibria (VLE), molar excess Gibbs energies, G E m , molar excess enthalpies, H E m , and isobaric molar excess heat capacities, C E pm , of the binary systems studied are well represented by DISQUAC. There is a good agreement between experimental H E m values of related ternary mixtures, and DISQUAC predictions obtained by means of binary interaction parameters only DISQUAC improves very meaningfully UNIFAC results on H E m , C E pm , properties which are closely related to the molecular structure of the mixture components. The enthalpy (H CO-S int ) of the ketone-aromatic hydrocarbon interactions has been evaluated. These interactions become weaker when the alkanone size increases in mixtures with a given aromatic hydrocarbon, or when the aliphatic surface of the alkylbenzene is increased in systems with a given ketone. Steric effects are more relevant in 1,4-dimethylbenzene mixtures than in those with ethylbenzene. The application of the Kirkwood-Buff formalism to mixtures including toluene or ethylbenzene shows that orientational effects, related to ketone-ketone interactions, exist in solutions with the shorter 2-alkanones. Such effects are weakened when the chain length of the 2-alkanone increases. The opposite behaviour is observed when increasing the aliphatic surface of the alkylbenzene in systems with a given 2-alkanone. The cyclohexanone + benzene mixture shows a structure close to random mixing.

Experimental densities, q, and speeds of sound, u, have been measured at (293.15-303.15) K for the systems methanol, 1-butanol or 1-decanol + 3,6,9-trioxaundecane using a vibrating-tube densimeter and sound analyzer Anton Paar model DSA-5000. These values were used to calculate excess molar volumes, V E m , excess adiabatic compressibilities, j E S , and excess speeds of sound, u E . Data available in the literature on excess molar enthalpies, H E m , and on excess molar isobaric heat capacities, C E p;m , of 1-alkanol + linear polyether mixtures indicate that: (i) interactions are mainly of dipolar type, particularly for solutions with longer 1-alkanols; (ii) the ability of the ether to break the alcohol self-association increases with the number of CH 2 CH 2 O groups in the oxaalkane. The enthalpies of the alcohol-ether interactions, DH OHÀO , have been determined. In mixtures with a given polyether, DH OHÀO increases with the alcohol size. For 1-alkanol + CH 3 O(CH 2 CH 2 O) n CH 3 systems, DH OHÀO decreases for increased n values. Alcoholether interactions are stronger in mixtures with linear polyethers than in those with monoethers.V E m data show the existence of free volume effects in solutions including methanol or ethanol. These effects become more important for large n values, which is supported by values of @V E m @T P . The Flory model has been used to investigate orientational effects in the systems under study. It is shown that orientational effects are relevant in mixtures with methanol or ethanol, and that the behaviour of the remaining systems is close to that of random mixing. Solutions with 3,6-dioxaoctane slightly differ from this trend and are characterized by weak orientational effects. We have also applied the Flory model to 1-alkanol + PEG-250, or +PEG-350 mixtures, which behave similarly to those including linear polyethers. Orientational effects are much stronger in 1-alkanol + linear monoether systems, and are roughly independent of the mixture components. Results obtained in this work are consistent with those obtained previously when applying the Kirkwood-Buff formalism.

Densities, ρ, and speeds of sound, u, of 2-propanone + dipropylamine, + dibutylamine or + triethylamine systems have been measured at (293.15, 298.15 and 303.15) K and atmospheric pressure using a vibrating tube densimeter and sound analyser Anton Paar model DSA-5000. The ρ and u values were used to calculate excess molar volumes, V E , and the excess functions at 298.15 K for the thermal expansion coefficient, α P E , and for the isentropic compressibility, K S E at 298.15 K. V E , K S E and α P E are positive magnitudes. When replacing dipropylamine by dibutylamine or triethylamine in the studied mixtures, the excess functions increase. This may be ascribed to the interactions between unlike molecules which are more important in the former solutions. From the comparison with similar data obtained for 2-propanone + aniline, + N-methylaniline, or + pyridine systems, it is concluded that interactions between unlike molecules are stronger in mixtures containing aromatic amines. Free volume effects are present in solutions with dipropyl or dibutylamine as the V E curves are shifted towards higher mole fractions of 2-propanone.

Densities, ρ, and speeds of sound, u, of 2-propanone + dipropylamine, + dibutylamine or + triethylamine systems have been measured at (293.15, 298.15 and 303.15) K and atmospheric pressure using a vibrating tube densimeter and sound analyser Anton Paar model DSA-5000. The ρ and u values were used to calculate excess molar volumes, V E , and the excess functions at 298.15 K for the thermal expansion coefficient, α P E , and for the isentropic compressibility, K S E at 298.15 K. V E , K S E and α P E are positive magnitudes. When replacing dipropylamine by dibutylamine or triethylamine in the studied mixtures, the excess functions increase. This may be ascribed to the interactions between unlike molecules which are more important in the former solutions. From the comparison with similar data obtained for 2-propanone + aniline, + N-methylaniline, or + pyridine systems, it is concluded that interactions between unlike molecules are stronger in mixtures containing aromatic amines. Free volume effects are present in solutions with dipropyl or dibutylamine as the V E curves are shifted towards higher mole fractions of 2-propanone.

Molar excess enthalpies, H E m , at 298.15 K and 0.1 MPa have been measured using a Tian-Calvet microcalorimeter for N,N,N-triethylamine (TEA) + 2-alkanone mixtures. These data have been used to determine H N-CO , the enthalpy of the amine-ketone interaction, which is practically independent of the ketone size. This allows explain the observed H E m decrease when the ketone size is increased in terms of a lower positive contribution to H E m from the breaking of the alkanone-alkanone interactions. Inspection of molar excess volumes and of molar excess internal energies at constant volume (determined in this work) reveals the existence of structural effects, which are more important for mixtures with 2-heptanone. Tertiary alkyl amine + 2-alkanone, and amino-ketone + n-alkane mixtures have been treated in terms of DISQUAC. The interaction parameters for the carbonyl/amine contacts are reported. It is shown that such contacts are essentially dispersive. Proximity effects in amino-ketone mixtures lead to increased dispersive parameters in comparison to those of amine + ketone solutions. Steric effects related to the length of the alkyl chains attached to the N atom lead to decreased dispersive parameters. DISQUAC describes accurately vapour-liquid equilibria (VLE) and H E m of the investigated mixtures, which have been also treated using UNIFAC (Dortmund version). UNIFAC predictions compare well with DIS-QUAC results for TEA mixtures. For amino-ketone systems, UNIFAC calculations largely differ from the experimental results. This reveals that interactions parameters must be modified to take into account proximity effects.

SIRPα, an ITIMs-containing signaling receptor, negatively regulates leukocyte responses through extracellular interactions with CD47. However, the dynamics of SIRPα-CD47 interactions on the cell surface and the governing mechanisms remain unclear. Here we report that while the purified SIRPα binds to CD47 and that SIRPα is expressed on monocytes and monocytic THP-1 or U937, these SIRPα are ineffective to mediate cell binding to immobilized CD47. However, cell binding to CD47 is significantly enhanced when monocytes transmigrating across endothelia, or being differentiated into macrophages. Cell surface labeling reveals SIRPα to be diffused on naïve monocytes but highly clustered on transmigrated monocytes and macrophages. Protein crosslink and equilibrium centrifugation confirm that SIRPα in the latter cells forms oligomerized complexes resulting in increased avidity for CD47 binding. Furthermore, formation of SIRPα complexes/clusters requires the plasma membrane 'lipid rafts' and the activity of Src family kinase during macrophage differentiation. These results together suggest that 'clustering' SIRPα into plasma membrane microdomains is essential for activated monocytes and macrophages to effectively interact with CD47 and initiate intracellular signaling.