The function of the RNA-binding protein TEL1 in moss reveals ancient regulatory mechanisms of shoot development

The shoot represents the basic body plan in land plants. It consists of a repeated structure composed of stems and leaves. Whereas vascular plants generate a shoot in their diploid phase, non-vascular plants such as mosses form a shoot (called the gametophore) in their haploid generation. The evolution of regulatory mechanisms or genetic networks used in the development of these two kinds of shoots is unclear. TERMINAL EAR1-like genes have been involved in diploid shoot development in vascular plants. Here, we show that disruption of PpTEL1 from the moss Physcomitrella patens, causes reduced protonema growth and gametophore initiation, as well as defects in gametophore development. Leafy shoots formed on ΔTEL1 mutants exhibit shorter stems with more leaves per shoot, suggesting an accelerated leaf initiation (shortened plastochron), a phenotype shared with the Poaceae vascular plants TE1 and PLA2/LHD2 mutants. Moreover, the positive correlation between plastochron length and leaf size observed in ΔTEL1 mutants suggests a conserved compensatory mechanism correlating leaf growth and leaf initiation rate that would minimize overall changes in plant biomass. The RNA-binding protein encoded by PpTEL1 contains two N-terminus RNA-recognition motifs, and a third C-terminus non-canonical RRM, specific to TEL proteins. Removal of the PpTEL1 C-terminus (including this third RRM) or only 16–18 amino acids within it seriously impairs PpTEL1 function, suggesting a critical role for this third RRM. These results show a conserved function of the RNA-binding PpTEL1 protein in the regulation of shoot development, from early ancestors to vascular plants, that depends on the third TEL-specific RRM.

Ancient Philosophers on Mental Illness

This dissertation is about ancient philosophers notions of mental illness, from Plato onwards. Mental illness here means disorders that, in ancient medical thought, were believed to originate in the body but to manifest themselves predominantly through mental symptoms. These illnesses were treated by physical means, which were believed to address the bodily cause of the illness, conceived of as an elemental imbalance or a state of cephalic stricture , for example. Sometimes the mental symptoms were addressed directly by psychotherapeutic means. The first and most important question explored concerns how the ancient philosophers responded to the medical notion of mental illness, and how they explained such illnesses in their theories of physiology and psychology. Although the illnesses are seldom discussed extensively, the philosophers were well aware of their existence and regarded their occurrence an indication of the soul s close dependence on the body. This called for a philosophical account. The second question addressed has to do with the ancient philosophers role as experts in mental problems of a non-medical kind, such as unwanted emotions. These problems were dubbed diseases of the soul , and the philosophers thus claimed to be doctors of the soul. Although the distinction between mental illnesses and diseases of the soul was often presented as rather obvious, there was some vagueness and overlap. There is still a third question that is explored, concerning the status of both mental illnesses and diseases of the soul as unnatural conditions, the role of the human body in the philosophical aetiologies of evil, and the medico-philosophical theories of psycho-physiological temperaments. This work consists of an introduction and five main chapters, focusing on Plato, Aristotle, the Stoics and Galen, and the Sceptics, the Epicureans and later Platonists. The sources drawn on are the original Greek and Latin philosophical and medical texts. It appears that the philosophers accepted the medical notion of mental illness, but interpreted it in various ways. The differences in interpretation were mostly attributable to differences in their theories of the soul. Although the distinction between mental illness and diseases of the soul was important, marking the boundary between the fields of expertise of medicine and philosophy, and of the individual s moral responsibilities, the problematic aspects of establishing it are discussed rather little in ancient philosophy. There may have been various reasons for this. The medical descriptions of mental illness are often extreme, symptoms of the psychotic type excluding the possibility of the condition being of the non-medical kind. In addition, the rigid normativeness of ancient philosophical anthropologies and their rigorous notion of human happiness decreased the need to assess the acceptability of individual variation in their emotional and intellectual lives and external behaviour.

Geoarchaeological Evidence of a Chola-Period Tsunami from an Ancient Port at Kaveripattinam on the Southeastern Coast of India

Literature of the ancient Chola Dynasty (A.D. 9th-11th centuries) of South India and recent archaeological excavations allude to a sea flood that crippled the ancient port at Kaveripattinam, a trading hub for Southeast Asia, and probably affected the entire South Indian coast, analogous to the 2004 Indian Ocean tsunami impact. We present sedimentary evidence from an archaeological site to validate the textual references to this early medieval event. A sandy layer showing bed forms representing high-energy conditions, possibly generated by a seaborne wave, was identified at the Kaveripattinam coast of Tamil Nadu, South India. Its sedimentary characteristics include hummocky cross-stratification, convolute lamination with heavy minerals, rip-up clasts, an erosional contact with the underlying mud bed, and a landward thinning geometry. Admixed with 1000-year-old Chola period artifacts, it provided an optically stimulated luminescence age of 1091 perpendicular to 66 yr and a thermoluminescence age of 993 perpendicular to 73 yr for the embedded pottery sherds. The dates of these proxies converge around 1000 yr B. P., correlative of an ancient tsunami reported from elsewhere along the Indian Ocean coasts. (C) 2011 Wiley Periodicals, Inc.

Ballistic Studies on TiB2-Ti Functionally Graded Armor Ceramics

The objective of this paper is to discuss the results of the ballistic testing of spark plasma sintered TiB2-Ti based functionally graded materials (FGMs) with an aim to assess their performance in defeating small-calibre armor piercing projectiles. We studied the efficacy of FGM design and compared its ballistic properties with those of TiB2-based composites as well as other competing ceramic armors. The ballistic properties are critically analyzed in terms of depth of penetration, ballistic efficiency, fractographs of fractured surfaces as well as quantification of the shattered ceramic fragments. It was found that all the investigated ceramic compositions exhibit ballistic efficiency (eta) of 5.1 -5.9. We also found that by increasing the thickness of FGM from 5 mm to 7.8 mm, the ballistic property of the composite degraded. Also, the strength of the ceramic compositions studied is sufficient to completely fracture the nose of the pointed projectile used. Analysis of the ceramic fragments (2 mu m-10 mm) showed that harder the ceramic, coarser were the fragments formed. On comparing the results with available armor systems, it has been concluded that TiB2 based composites can show better ballistic properties, except B4C. SEM analysis of the fragments obtained after testing with FGM showed formation of cleavage steps as well as presence of intergranular cracks, indicating that the FGM fractured by mixed mode of failure. It can be concluded that the FGM developed has lower ballistic properties compared to its monolith TiB2-20 wt.% Ti.

Phylogenetic analysis and molecular dating suggest that hemidactylus anamallensis is not a member of the hemidactylus radiation and has an ancient late cretaceous origin

Background of the Work: The phylogenetic position and evolution of Hemidactylus anamallensis (family Gekkonidae) has been much debated in recent times. In the past it has been variously assigned to genus Hoplodactylus (Diplodactylidae) as well as a monotypic genus `Dravidogecko' (Gekkonidae). Since 1995, this species has been assigned to Hemidactylus, but there is much disagreement between authors regarding its phylogenetic position within this genus. In a recent molecular study H. anamallensis was sister to Hemidactylus but appeared distinct from it in both mitochondrial and nuclear markers. However, this study did not include genera closely allied to Hemidactylus, thus a robust evaluation of this hypothesis was not undertaken. Methods: The objective of this study was to investigate the phylogenetic position of H. anamallensis within the gekkonid radiation. To this end, several nuclear and mitochondrial markers were sequenced from H. anamallensis, selected members of the Hemidactylus radiation and genera closely allied to Hemidactylus. These sequences in conjunction with published sequences were subjected to multiple phylogenetic analyses. Furthermore the nuclear dataset was also subjected to molecular dating analysis to ascertain the divergence between H. anamallensis and related genera. Results and Conclusion: Results showed that H. anamallensis lineage was indeed sister to Hemidactylus group but was separated from the rest of the Hemidactylus by a long branch. The divergence estimates supported a scenario wherein H. anamallensis dispersed across a marine barrier to the drifting peninsular Indian plate in the late Cretaceous whereas Hemidactylus arrived on the peninsular India after the Indian plate collided with the Eurasian plate. Based on these molecular evidence and biogeographical scenario we suggest that the genus Dravidogecko should be resurrected.

Bronze and iron weapons from Luristan

The 30,000 km2 province of Luristan is situated in western Iran and encompasses the upper valleys of the Zagros Mountains. Even today, local tribesmen inhabit Luristan with their settlement patterns similar to ancient times. Several scientific excavations in the Luristan region have uncovered evidence that this particular region was a major attraction for human settlements from the Paleolithic era onwards. In Ancient Iran, the existence of rich mines together with discoveries made by innovative and inventive artisans spurred the growth of the metalworking culture as an art and a skill among early human communities in Ancient Iran. The art of Luristan can be described as the art of nomadic herdsmen and horsemen with an emphasis on the crafting of small, easily portable objects, among these a number of bronze daggers, swords and other weapons. Throughout its history, Luristan was never an ethnic or political entity because Luristan has been occupied by various tribes and races, throughout its history. Next to Elamites, other tribes who inhabited Luristan were the Hurrians, Lullubians, Kutians, and Kassites. As local tribesmen of Luristan were illiterate, information about their history can only be partially reconstructed from the literature of their southern neighbors: the Elamites and Babylonians. Luristan smiths made weapons for both civilizations. The region was later invaded by Assyrians and finally the Iranians settled the area and absorbed the local tribes. Following an accidental find by the local inhabitants in Luristan in 1928 CE, a number of unlawful diggings reveal a number of metal objects made of bronze and iron that showed a high level of craftsmanship. These objects were offered for sale on the art market with fancy names to hide their origin. The subsequent scientific excavations several decades after the initial discovery provided fascinating information about the culture of Luristan. The metalworking art of Luristan spans a time period from the third millennium BC to the Iron Age. The artifacts from Luristan seem to possess many unique and distinctive qualities, and are especially noteworthy for the apparently endless, intricate diversity and detail that they characteristically depict. The bronze artifacts found in or attributed to Luristan can be each be classed under five separate heads: a) arms and armor, including swords, dirks, daggers, axes, mace heads, spearheads, shields, quiver plaques, protective bronze girdles, helmets; b) implements related to horsemanship, including decorative or ornamental objects for horses as well as bits and snaffles; c) items for personal adornment and hygiene, including anklets, bangles, bracelets, finger rings, earrings and tweezers; d) ceremonial and ritual objects, including talismans, idols, pins, anthropomorphic and zoomorphic figurines; and e) utilitarian objects comprising various vessels and tools, including beakers, bowls and jugs. The scope of this article is limited to a discussion of the bronze and iron weapons made in Luristan. The techniques used for making bronze weapons in Luristan included: casting with open molds, casting with close molds, and casting with lost wax process. For metal sheets used for quiver plaques and bronze protective belts, the hammering technique was used. Edged weapons made in Luristan can be classified into: a) daggers, dirks, and swords with tangs; b) daggers, dirks, and swords with flanges; and c) daggers, dirks, and swords with cast-on hilts. Next to bronze, iron was also used for making weapons such as the characteristic weapon from this area, the iron mask sword.

Damage development in an armor ceramic under quasi-static indentation

The objective of the present study is to assess the capabilities of a recently developed mechanism-based model for inelastic deformation and damage in structural ceramics. In addition to conventional lattice plasticity, the model accounts for microcrack growth and coalescence as well as granular flow following comminution. The assessment is made through a coupled experimental/computational study of the indentation response of a commercial armor ceramic. The experiments include examinations of subsurface damage zones along with measurements of residual surface profiles and residual near-surface stresses. Extensive finite element computations are conducted in parallel. Comparisons between experiment and simulation indicate that the most discriminating metric in the assessment is the spatial extent of subsurface damage following indentation. Residual stresses provide additional validation. In contrast, surface profiles of indents are dictated largely by lattice plasticity and thus provide minimal additional insight into the inelastic deformation resulting from microcracking or granular flow. A satisfactory level of correlation is obtained using property values that are either measured directly or estimated from physically based arguments, without undue reliance on adjustable (nonphysical) parameters. © 2011 The American Ceramic Society.

Ancient Chinese algorithm: The Ying Buzu Shu (method of surplus and deficiency) vs Newton iteration method

Air exploratory discussion of an ancient Chinese algorithm, the Ying Buzu Shu, in about 2nd century BC, known as the rule of double false position in the West is given. In addition to pointing out that the rule of double false position is actually a translation version of the ancient Chinese algorithm, a comparison with well-known Newton iteration method is also made. If derivative is introduced, the ancient Chinese algorithm reduces to the Newton method. A modification of the ancient Chinese algorithm is also proposed, and some of applications to nonlinear oscillators are illustrated.