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Recent infection testing algorithms (RITA) for HIV combine serological assays with epidemiological data to determine likely recent infections, indicators of ongoing transmission. In 2016, we integrated RITA into national HIV surveillance in Ireland to better inform HIV prevention interventions. We determined the avidity index (AI) of new HIV diagnoses and linked the results with data captured in the national infectious disease reporting system. RITA classified a diagnosis as recent based on an AI < 1.5, unless epidemiological criteria (CD4 count <200 cells/mm3; viral load <400 copies/ml; the presence of AIDS-defining illness; prior antiretroviral therapy use) indicated a potential false-recent result. Of 508 diagnoses in 2016, we linked 448 (88.1%) to an avidity test result. RITA classified 12.5% of diagnoses as recent, with the highest proportion (26.3%) amongst people who inject drugs. On multivariable logistic regression recent infection was more likely with a concurrent sexually transmitted infection (aOR 2.59; 95% CI 1.04–6.45). Data were incomplete for at least one RITA criterion in 48% of cases. The study demonstrated the feasibility of integrating RITA into routine surveillance and showed some ongoing HIV transmission. To improve the interpretation of RITA, further efforts are required to improve completeness of the required epidemiological data.
We investigate the approximation of quadratic Dirichlet
-functions over function fields by truncations of their Euler products. We first establish representations for such
-functions as products over prime polynomials times products over their zeros. This is the hybrid formula in function fields. We then prove that partial Euler products are good approximations of an
-function away from its zeros and that, when the length of the product tends to infinity, we recover the original
-function. We also obtain explicit expressions for the arguments of quadratic Dirichlet
-functions over function fields and for the arguments of their partial Euler products. In the second part of the paper we construct, for each quadratic Dirichlet
-function over a function field, an auxiliary function based on the approximate functional equation that equals the
-function on the critical line. We also construct a parametrized family of approximations of these auxiliary functions and prove that the Riemann hypothesis holds for them and that their zeros are related to those of the associated
-function. Finally, we estimate the counting function for the zeros of this family of approximations, show that these zeros cluster near those of the associated
-function, and that, when the parameter is not too large, almost all the zeros of the approximations are simple.
In 2011 the Incidence Assay Critical Path Working Group reviewed the current state of HIV incidence assays and helped to determine a critical path to the introduction of an HIV incidence assay. At that time the Consortium for Evaluation and Performance of HIV Incidence Assays (CEPHIA) was formed to spur progress and raise standards among assay developers, scientists and laboratories involved in HIV incidence measurement and to structure and conduct a direct independent comparative evaluation of the performance of 10 existing HIV incidence assays, to be considered singly and in combinations as recent infection test algorithms. In this paper we report on a new framework for HIV incidence assay evaluation that has emerged from this effort over the past 5 years, which includes a preliminary target product profile for an incidence assay, a consensus around key performance metrics along with analytical tools and deployment of a standardized approach for incidence assay evaluation. The specimen panels for this evaluation have been collected in large volumes, characterized using a novel approach for infection dating rules and assembled into panels designed to assess the impact of important sources of measurement error with incidence assays such as viral subtype, elite host control of viraemia and antiretroviral treatment. We present the specific rationale for several of these innovations, and discuss important resources for assay developers and researchers that have recently become available. Finally, we summarize the key remaining steps on the path to development and implementation of reliable assays for monitoring HIV incidence at a population level.
A compilation of direct age determinations for Late Pleistocene human fossils in eastern Europe and Asia is presented in this paper, and current problems with the dating of hominids in these regions are discussed. Only 25 human finds (4 Neanderthals and 21 modern humans) have been directly dated from Pleistocene eastern Europe and Asia. Indirect dating of human remains (using presumably associated organics) often is insecure, especially when information about the exact provenance of human fossils is lacking. Continuation of direct dating of Late Pleistocene humans in Eurasia, primarily with the help of the accelerator mass spectrometry (AMS) 14C method, is therefore an urgent task.
The chronological status of Pleistocene fossils of early modern humans in the People's Republic of China is based almost exclusively on indirect dating of the stratigraphic context and faunal and radiocarbon dating of associated or supposedly associated archaeological specimens. A similar pattern is observed in Korea and Japan. This paper examines the 14C and other dating techniques of early modern humans in East Asia to gain a more complete and up-to-date understanding of their chronology.
Toxoplasmosis affects a third of the global population and is of particular concern for immunologically compromised individuals. Toxoplasmosis induces host physiological events ranging from immunological to metabolic responses across multiple biological compartments. To understand the sequence of host responses during acute and chronic Toxoplasma gondii infection, eight male BALB/c mice were infected with 2000 T. gondii ME49 tachyzoites with a further eight uninfected mice used as controls. Plasma cytokines status, urinary metabolic profiling and fecal microbial profiles were characterized to monitor temporal variation related to T. gondii infection. The results showed elevated serum interferon-γ (IFN-γ), interleukin-12p40 and necrosis factor-α during acute phase of infection with concomitant perturbation in host energy metabolism and host-gut microbiome co-metabolism of phenolics and a shift in microbial composition. However, the differences were less pronounced during the putative chronic phase of infection with elevated IFN-γ, differences in urinary N-acetyls and O-acetyls of glycoproteins with no shift in gut microbial composition. Structural equation modelling on the current data showed host immune responses as the main driver for changes observed in urinary metabolites and gut microbial composition. Such an approach can be applied to other models of infectious diseases to aid understanding of host–pathogen interactions and potential biomarker discovery.
PROSOPOGRAPHY IS ABOUT identity and about context. Domesday Book offers a peculiarly satisfying challenge for those who enjoy the jigsaw puzzles of the method. Some 45,000 personal names occur in the text, and 29,000 placenames. The textual context of a name is an obvious primary clue when seeking to resolve these many thousands of name-records into names of individual persons and places, but these necessary onomastic exercises are merely to find the corner pieces. Those stalwarts of prosopographical analysis, genealogical links, provide the straight pieces that form the frame of the puzzle. If we wish to see the full picture, however, we should be aware that over-reliance on family relationships, and the ostensible inheritance gains of marriage alliances, may steer us away from, rather than towards, the full potential offered by a prosopographical approach to Domesday Book. That potential is nothing less than a full understanding of how society changed between 1066 and 1086, because it will establish just how title to land passed from the English to the Normans and their allies, and reveal the varied links that formed the bonds of society. Various mechanisms of land transfer have been proposed. The most visible was antecession, that is, the sokeright of one or more named thegns was given to a newcomer and made the basis of the latter's tenancy-in-chief or honour. The lands of the antecessor's median thegns also became the newcomer's to distribute to his own mesne tenants. Whilst the principle of antecession seems predominantly to govern the legal transfer of land from one person to another throughout the period 1066 to 1086, there are exceptions based on a direct grant by writ of the king. Then there are the so-called hundredal grants, geographically defined estates that are more artificially created for strategic purposes, such as the rapes of Sussex and the marcher county of Cheshire. Also alleged as mechanisms are usurpation and marriage alliances.
In order to achieve both the identification of individuals and to say something useful about them, we need to approach the task within the framework of a set of questions suggested by a layered approach to the overall context of Domesday Book.
Observations of metal absorption lines in the spectra of QSOs out to z > 6 are providing an important probe into the enrichment and ionization state of the intergalactic medium (IGM) at the tail end of reionization. Using simulations with four different feedback models, including the Illustris and Sherwood simulations, we investigate how the overall incidence rate and equivalent width distribution of metal-line absorbers varies with the galactic wind scheme. The low-ionization absorbers are reasonably insensitive to the feedback implementation, with all models reasonably close to the observed incidence rate of O i absorbers. However, all of our models struggle to reproduce the observations of C iv, which is probing overdensities close to the mean at z ~ 6, suggesting that the metals are not being transported out into the IGM efficiently enough in these simulations.
Non-alcoholic fatty liver disease (NAFLD) is an independent predictor of CVD in otherwise healthy individuals. Low n-3 PUFA intake has been associated with the presence of NAFLD; however, the relationship between a biomarker of n-3 status – the Omega-3 Index – and liver fat is yet to be elucidated. A total of eighty overweight adults (fifty-six men) completed the anthropometric and biochemical measurements, including the Omega-3 Index, and underwent proton magnetic resonance spectroscopy assessment of liver fat. Bivariate correlations and multiple regression analyses were performed with reference to prediction of liver fat percentage. The mean Omega-3 Index was high in both NAFLD (intrahepatic lipid concentration≥5·5 %) and non-NAFLD groups. The Omega-3 Index, BMI, waist circumference, glucose, insulin, TAG, high-sensitive C-reactive protein (hsCRP) and alanine aminotransferase (ALT) were positively correlated, and HDL and erythrocyte n-6:n-3 ratio negatively correlated with liver fat concentration. Regression analysis found that simple anthropometric and demographic variables (waist, age) accounted for 31 % of the variance in liver fat and the addition of traditional cardiometabolic blood markers (TAG, HDL, hsCRP and ALT) increased the predictive power to 43 %. The addition of the novel erythrocyte fatty acid variable (Omega-3 Index) to the model only accounted for a further 3 % of the variance (P=0·049). In conclusion, the Omega-3 Index was associated with liver fat concentration but did not improve the overall capacity of demographic, anthropometric and blood markers to predict NAFLD.
We report upon laboratory experiments and numerical simulations examining the evolution of an interfacial internal solitary wave incident upon a triangular ridge whose peak lies below the interface. If the ridge is moderately large, the wave is observed to shoal and break similar to solitary waves shoaling upon a constant slope, but interfacial waves are also observed to transmit over and reflect from the ridge. In laboratory experiments, by measuring the interface displacement as it evolves in time, we measure the relative transmission and reflection of available potential energy after the incident wave has interacted with the ridge. The numerical simulations of laboratory- and ocean-scale waves measure both the available potential and kinetic energy to determine the partition of incident energy into that which is transmitted and reflected. From shallow-water theory, we define a critical amplitude,
, above which interfacial waves are unstable. The transmission is found to decrease from one to zero as the ratio of the incident wave amplitude to
increases from less than to greater than one. Empirical fits are made to analytic curves through measurements of the transmission and reflection coefficients.
Carbon nanotubes (CNTs) have been considered as a promising interconnect material to replace the solder bump used in the flip chip package because of their special electrical, mechanical and thermal properties, which may promote both the performance and reliability of the flip chip packaging. In this paper, electrophoretic deposition (EPD) of CNTs on substrates has been demonstrated for the interconnect application. EPD is a simple, low cost and high throughput process that is capable to produce densely packed film with good homogeneity at low temperature. By altering the electric fields and deposition time during the EPD process, the thickness of the CNTs film could be controlled. In this study, multi-walled carbon nanotubes (MWCNTs) were successfully coated on the various substrates using the EPD method. A highly uniform CNTs microstructure film with thickness over 5 µm was achieved. In addition, the selective depositions of CNTs on the pre-defined bond pads to form CNTs bumps were also accomplished. By employing typical flip-chip bonding technique, high density CNTs bumps were aligned to form a test chip/host substrate interconnects. The electrical conductivity of the CNTs interconnects was carried out using four-point probe measurement. Reliable electrical contacts with linear relationship in the current-voltage (I-V) characteristic suggesting ohmic behaviour were attained. The overall resistances extracted were also relatively low. These superior electrical properties have demonstrated that the CNTs bumps deposited using EPD method is a viable way to serve as an alternative to current metal solder interconnects material such as Sn-Pb alloys. Hence, it offers a promising interconnect application in the quest for device miniaturization in microelectronic industry.
Who commissioned the Bayeux Tapestry and why? The question remains open after a considerable body of innovative new writing on the subject during the last decade has given grounds for a major re-evaluation of the Tapestry. Two ideas in particular demand fuller investigation: first, that the Tapestry is an independent, pro-English, source, artistically the first major fusion of Anglo-Norman-Scandinavian iconography and linguistically influenced by both English and French, and secondly, that it was produced as early as 1068 x 1070, since it precedes the Norman vilification of Harold that arose as a response to the various revolts that began in May 1068. Despite the ingenuity of attempts to demonstrate the contrary intention from the curious figures appearing in the borders, the fact is that not a single pejorative is ever attached to Harold in the tituli of the work. Recent detailed studies of the depictions of Harold show him to have been represented with honour even in the tightest of corners. The Tapestry therefore certainly predates the systematic assault on Harold as a perjured usurper, and thus a tyrant whose reign was thereby nullified, which was the legal case fashioned by Archbishop Lanfranc of Canterbury and subsequently presented at Rome, as demonstrated nearly twenty years ago by George Garnett. A similar assault was made on the prelacy and memory of Lanfranc's predecessor Stigand, who had controversially been appointed whilst the archbishop ousted in 1052 still lived. A more longstanding tendency to date the Tapestry to 1070 x 1082, with Bishop Odo as the generally assumed patron, has entailed some fairly contorted attempts to understand the inter-relationships between this and contemporary or near contemporary written sources.
Unlike proteins, the RNA backbone has numerous degrees of freedom (eight, if one counts the sugar pucker), making RNA modeling, structure building and prediction a multidimensional problem of exceptionally high complexity. And yet RNA tertiary structures are not infinite in their structural morphology; rather, they are built from a limited set of discrete units. In order to reduce the dimensionality of the RNA backbone in a physically reasonable way, a shorthand notation was created that reduced the RNA backbone torsion angles to two (η and θ, analogous to φ and ψ in proteins). When these torsion angles are calculated for nucleotides in a crystallographic database and plotted against one another, one obtains a plot analogous to a Ramachandran plot (the η/θ plot), with highly populated and unpopulated regions. Nucleotides that occupy proximal positions on the plot have identical structures and are found in the same units of tertiary structure. In this review, we describe the statistical validation of the η/θ formalism and the exploration of features within the η/θ plot. We also describe the application of the η/θ formalism in RNA motif discovery, structural comparison, RNA structure building and tertiary structure prediction. More than a tool, however, the η/θ formalism has provided new insights into RNA structure itself, revealing its fundamental components and the factors underlying RNA architectural form.
Our study describes the synthesis of novel nanoscale Pd cage and wires whose sizes and shapes are templated by mesoporous matrices. The templates used are cubic phase MCM-48 and hexagonal phase CnMCM-41 (n = 16, and 22), SBA-15, which have pore diameters of ∼3, ∼3.8, ∼4.7, and ∼9 nm, respectively. For Pd@MCM-48, the Pd metal forms spherical domains (∼38 nm) consisting of three dimensionally interconnected into Pd arrays; for Pd@SBA-15 and Pd@MCM-41, the Pd metal forms of one-dimensional wires. Etching out the matrix produces porous Pd cages (pore sizes of ∼1.5 - 2.0 nm) with retaining original domain sizes of ∼38 nm; similarly Pd@SBA-15 and Pd@MCM-41 afford freestanding Pd nanowires. All the materials are examined by TEM, XRD, BET, and EDAX analysis. Furthermore, the thermal behavior of Pd nanowire is briefly described.
A novel method of two-dimensional (2-D) synthesis of anisotropic nanoparticles have been developed in which nanoparticle growth is an example of 2-D process where true 2-D diffusion of precursor molecules and active intermediates, metal atoms and its complexes, nucleus and growing nanoparticles, surfactants and additives occurs only in the plain of a monolayer at the gas/liquid interface. Nanoparticles were generated via ultraviolet decomposition of a volatile insoluble metal-organic precursor compound (iron pentacarbonyl) and by chemical reduction of palladium from Pd3(CH3COO)6 molecules in a mixed Langmuir monolayer with stearic acid, arachidic acid or octadecyl amine on the aqueous subphase surface. The properties of such surfactants to form Langmuir monolayer and to prevent aggregation of nanoparticles were here combined successfully. Atomic force microscopy, scanning tunneling microscopy and transmission electron microscopy techniques were used to study morphology of deposited nanoparticulate monolayers. The size and shape of nanoparticles were dependent substantially on the monolayer composition and state during the synthesis process. We demonstrate that planar synthesis in a monolayer at the gas/liquid interface allows to produce anisotropic extremely flat nanoparticles with very high surface to volume ratio and unique morphologies such as iron-containing magnetic nano-rings.
We have synthesized single crystal bismuth nanowires by pressure injecting molten Bi into anodic alumina templates. By varying the template fabrication conditions, nanowires with diameters ranging from 10 to 200nm and lengths of ~50[.proportional]m can be produced. We present a scheme for measuring the resistance of a single Bi nanowire using a 4-point measurement technique. The nanowires are found to have a 7nm thick oxide layer which causes very high contact resistance when electrodes are patterned on top of the nanowires. The oxide is found to be resilient to acid etching, but can be successfully reduced in high temperature hydrogen and ammonia environments. The reformation time of the oxide in air is found to be less than 1 minute. Focused ion beam milling is attempted as an alternate solution to oxide removal.
We present here an electrical transport property study of Te-doped Bi nanowires, and Bi1−xSbx alloy nanowires embedded in a dielectric matrix. The crystal structure of the nanowires were characterized by X-ray diffraction measurements, indicating that the nanowires possess the same lattice structure as bulk Bi in the presence of a small amount of Te or Sb atoms. The resistance measurements of 40-nm Te-doped Bi nanowires were performed over a wide range of temperature (2 K≤ T ≤ 300 K), and the results are consistent with theoretical predictions. The 1D-to-3D localization transition and the boundary scattering effect are both observed in magneto-resistance measurements of Bi1−xSbx alloy nanowires at low temperatures (T < 4 K).