Naresuan University Journal
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Plant cellulose synthesis: CESA proteins crossing Kingdoms
No full textCellulose is a biopolymer of considerable economic importance. It is synthesised by the cellulose synthase complex (CSC) in species ranging from bacteria to higher plants. Enormous progress in our understanding of bacterial cellulose synthesis has come with the recent publication of both the crystal structure and biochemical characterisation of a purified complex able to synthesis cellulose in vitro. A model structure of a plant CESA protein suggests considerable similarity between the bacterial and plant cellulose synthesis. In this review article we will cover current knowledge of how plant CESA proteins synthesise cellulose. In particular the focus will be on the lessons learned from the recent work on the catalytic mechanism and the implications that new data on cellulose structure has for the assembly of CESA proteins into the large complex that synthesis plant cellulose microfibrils
Musical preferences and technologies: Contemporary material and symbolic distinctions criticised
No full textMusic as a mechanism for social distinction is well established. Yet, perhaps more than any other form of cultural expression, it is music which has been systematically transformed by emerging technologies. From the gramophone, radio, cassette and CD, through to portable devices and shared through social media, music is in constant flux. To separate taste for music from its various acquisitional forms is to undermine its role in society. In this article, our aim is to integrate within taste and cultural consumption analysis a salient dimension, such as technologies to acquire music, conceptualized as modes of musical exchange and formats used to listen to music. We argue that these are components of musical consumption practices which enhance our understanding on how symbolic boundaries are shaped today. Using multiple factor analysis, this study provides a simultaneous analysis of musical tastes and technological engagement in Chile. We find that uses of technologies share a unique relationship to musical taste. Musical taste remains a relevant process of distinction, but modes of exchange prove to be an emerging property. They, however, do not create new symbolic boundaries; rather, they are important in reinforcing those that exist
GPR combined with a positioning system to detect anti-personnel landmines
No full textLandmines and explosive remnants of war (ERW) are a serious problem in many countries around the world. In 2012, there were, on average, ten casualties per day globally [1]. Anti-Personnel (AP) landmines have been developed to have only a small amount of metal content, thus making them harder to find with metal detectors. Often there is less metal in a landmine than in “clutter” metallic objects, which are also found during the de-mining process. One reason landmine removal is a time-consuming task using the conventional metal detector is that it is not possible to classify the objects very accurately; consequently all positive signals must be investigated with equal caution. However, the dielectric material (e.g. main charge and plastic case) surrounding the metal detonator components generally occurs in landmines, and less so in clutter. Metal objects detected by a dual sensor without an associated detection of plastic objects can be ignored unless they are metal AP mines. One way to detect the plastic is to add a Ground Penetrating Radar system (GPR) to the conventional metal detector. Developments over the last decade combining GPR with traditional inductive metal detection have demonstrated the value of this approach [2]. GPR data is generally analysed by collating a series of reflection responses (A-Scans), collected over an evenly spaced series of positions in a single direction. This data set is termed a B-Scan. On conventional geotechnical GPR systems, a position encoder is attached to one of the wheels, in order to capture the data at regular intervals. Metal-detector type AP landmine detection systems are handheld devices without wheels, so some other way of detecting position needs to be found other than the operator's location. This paper describes an investigation into a positioning system for a handheld scanner. It describes how inertial measurements combined with a camera can determine the antenna position during the sensor sweep and how this information can be used to create the conventional B-Scan data sets. The paper compares the antenna-to-ground separation measurement extracted from both time and frequency domain GPR measurement systems to that given by an ultrasound distance sensor
The role of cryptotephra in refining the chronology of Late Pleistocene human evolution and cultural change in North Africa
No full textSites in North Africa hold key information for dating the presence of Homo sapiens and the distribution of Middle Stone Age (MSA), Middle Palaeolithic (MP) and Later Stone Age (LSA) cultural activity in the Late Pleistocene. Here we present new and review recently published tephrochronological evidence for five cave sites in North Africa with long MSA/MP and LSA cultural sequences. Four tephra horizons have been identified at the Haua Fteah (Cyrenaica, Libya). They include cryptotephra evidence for the Campanian Ignimbrite (CI) eruption dating to ~39 ka that allows correlation with other Palaeolithic sequences in the eastern Mediterranean and as far north as Russia. Cryptotephra have also been recorded from the Moroccan sites of Taforalt, Rhafas and Dar es-Soltane 1. At Taforalt the geochemical composition suggests a provenance in the Azores, while examples from Sodmein (Egypt) appear to derive from western Anatolia and another unknown source. In these latter examples chemical compositional data from relevant proximal volcanic centres is currently lacking so the identification of tephra in layers of known age and cultural association provides the first reliable age determinations for distal volcanic events and their geographical extent. The future potential for tephrochronological research in North Africa is also discussed
Repression of Esophageal Neoplasia and Inflammatory Signaling by Anti-miR-31 Delivery In Vivo.
No full textAre membrane clock and calcium clock involved in atrioventricular nodal conduction in young and aged
No full textGenetic background is a key determinant of glomerular extracellular matrix composition and organization.
No full textGalaxy alignments: Theory, modelling and simulations
No full textThe shapes of galaxies are not randomly oriented on the sky. During the galaxy formation and evolution process, environment has a strong influence, as tidal gravitational fields in large-scale structure tend to align the shapes and angular momenta of nearby galaxies. Additionally, events such as galaxy mergers affect the relative alignments of galaxies throughout their history. These "intrinsic galaxy alignments" are known to exist, but are still poorly understood. This review will offer a pedagogical introduction to the current theories that describe intrinsic galaxy alignments, including the apparent difference in intrinsic alignment between early- and late-type galaxies and the latest efforts to model them analytically. It will then describe the ongoing efforts to simulate intrinsic alignments using both \$N\$-body and hydrodynamic simulations. Due to the relative youth of this field, there is still much to be done to understand intrinsic galaxy alignments and this review summarises the current state of the field, providing a solid basis for future work
The interactions between temperature and activity levels in driving metabolic rate: theory, with empirical validation from contrasting ectotherms
No full textThe rate of change in resting metabolic rate (RMR) as a result of a temperature increase of 10 °C is termed the temperature coefficient (Q10), which is often used to predict how an organism’s total MR will change with temperature. However, this method neglects a potentially key component of MR; changes in activity level (and thus activity MR; AMR) with temperature may significantly alter the relationship between MR and temperature. The present study seeks to describe how thermal effects on total MR estimated from RMR–temperature measurements can be misleading when the contribution of activity to total MR is neglected. A simple conceptual framework illustrates that since the relationship between activity levels and temperature can be different to the relationship between RMR and temperature, a consistent relationship between RMR and total MR cannot be assumed. Thus the thermal effect on total MR can be considerably different to the thermal effect on RMR. Simultaneously measured MR and activity from three ectotherm species with differing behavioural and physiological ecologies were used to empirically examine how changes in temperature drive changes in RMR, activity level, AMR and the Q10 of MR. These species exhibited varied activity– and MR–temperature relationships, underlining the difficulty in predicting thermal influences on activity levels and total MR. These data support a model showing that thermal effects on total MR will deviate from predictions based solely on RMR; this deviation will depend upon the difference in Q10 between AMR and RMR, and the relative contribution of AMR to total MR. To develop mechanistic, predictive models for species’ metabolic responses to temperature changes, empirical information about the relationships between activity levels, MR and temperature, such as reported here, is required. This will supersede predictions based on RMR alone