The biological activities of arginine-vasotocin obtained by a new synthesis

Zusammenfassung Eine neue Synthese von Arginin-Vasotocin (= Arg⁸-Oxytocin = Ile³-Arginin-Vasopressin) wird beschrieben. Das reine synthetische Peptid erwies sich in verschiedenen biologischen Testen wirksamer als nach früheren Literaturangaben zu erwarten war.     

Die DNS-synthese im rattenherzen als funktion des lebensalters. Autoradiographische untersuchungen mit3H-thymidin

Summary The percentage of DNA-synthesising heart muscle nuclei of white rats (³H-thymidine, autoradiography) decreases rapidly during the first month of life reaching a minimum at the fourth month. From then up to 27 months the number of labelled muscle nuclei remains rather constant. Also in nuclei of connective tissue the³H-thymidine labelling index decreases as a function of the rats age. The number of mitotic figures is always about 10 times lower than labelled nuclei. Mostly in heart muscle cells they occur as collapsed mitoses never leading to cytoplasma division¹⁴.     

Stimulating illusory own-body perceptions

'Out-of-body' experiences (OBEs) are curious, usually brief sensations in which a person's consciousness seems to become detached from the body and take up a remote viewing position. Here we describe the repeated induction of this experience by focal electrical stimulation of the brain's right angular gyrus in a patient who was undergoing evaluation for epilepsy treatment. Stimulation at this site also elicited illusory transformations of the patient's arm and legs (complex somatosensory responses) and whole-body displacements (vestibular responses), indicating that out-of-body experiences may reflect a failure by the brain to integrate complex somatosensory and vestibular information.     

Fast heating of ultrahigh-density plasma as a step towards laser fusion ignition

Modern high-power lasers can generate extreme states of matter that are relevant to astrophysics, equation-of-state studies and fusion energy research. Laser-driven implosions of spherical polymer shells have, for example, achieved an increase in density of 1,000 times relative to the solid state. These densities are large enough to enable controlled fusion, but to achieve energy gain a small volume of compressed fuel (known as the 'spark') must be heated to temperatures of about 108 K (corresponding to thermal energies in excess of 10 keV). In the conventional approach to controlled fusion, the spark is both produced and heated by accurately timed shock waves, but this process requires both precise implosion symmetry and a very large drive energy. In principle, these requirements can be significantly relaxed by performing the compression and fast heating separately; however, this 'fast ignitor' approach also suffers drawbacks, such as propagation losses and deflection of the ultra-intense laser pulse by the plasma surrounding the compressed fuel. Here we employ a new compression geometry that eliminates these problems; we combine production of compressed matter in a laser-driven implosion with picosecond-fast heating by a laser pulse timed to coincide with the peak compression. Our approach therefore permits efficient compression and heating to be carried out simultaneously, providing a route to efficient fusion energy production.     

Introduction to the symposium on soil crust communities

Soil crust communities in semiarid and arid lands around the world have received increasing attention in the past two decades. A symposium on their ecology was presented at the annual meeting of the American Bryological and Lichenological Society held in 1991 in San Antonio, Texas. An introduction to the topic and an overview of the papers appearing in the proceedings volume are given in this prologue.     

Additions to knowledge of Paleocene mammals from the North Horn Formation, central Utah

The distinctive but inadequately known Paleocene faunas of central Utah are significant in that they sample a time interval not well represented by sequences in other areas. New materials from the Wagon Road (late Puercan) and Dragon (early Torrejonian) local faunas, North Horn Formation, provide additional information on the composition of the assemblages and systematics of included mammal taxa. The proteutherian ? Propalaeosinopa is recorded for the first time, from the Wagon Road fauna, indicating a significant extension for the enigmatic family Pantolestidae, otherwise first known from the Torrejonian. Associated premolars of Aphronorus simpsoni , a pentacodontid proteutherian from the Dragon fauna, indicated that the species is more distinct from its Torrejonian congener, A. fraudator , than previously suspected. New materials of Desmatoclaenus hermaeus uphold the synonymy of this species with D. paracreodus and permit more adequate definition of the genus with respect to the arctocyonid Loxolophus and the phenacodontid Tetraclaenodon ; because Desmatoclaenus appears to share derived morphology with Loxolophus , we refer it to the basal condylarth family Arctocyonidae. The periptychid condylarth Haploconus , represented in the Wagon Road fauna by the geologically oldest described species of the genus, H. elachistsus , is shown to be distinctive in the configuration of lower molars and premolars; H. elachistus appears to be more primitive than species known from the Torrejonian of New Mexico. Some features of Haploconus are suggestive of the Conacodontinae, a distinctive clade of diminutive periptychids.     

The nuclear γ-H2AX apoptotic ring: implications for cancers and autoimmune diseases

Apoptosis is a fundamental process for metazoan development. It is also relevant to the pathophysiology of immune diseases and cancers and to the outcome of cancer chemotherapies, as well as being a target for cancer therapies. Apoptosis involves intrinsic pathways typically initiated by DNA damaging agents and engaging mitochondria, and extrinsic pathways typically initiated by “death receptors” and their ligands TRAIL and TNF at the cell surface. Recently, we discovered the apoptotic ring, which microscopically looks like a nuclear annular staining early in apoptosis. This ring is, in three-dimensional space, a thick intranuclear shell consisting of epigenetic modifications including histone H2AX and DNA damage response (DDR) proteins. It excludes the DNA repair factors usually associated with γ-H2AX in the DDR nuclear foci. Here, we summarize our knowledge of the apoptotic ring, and discuss its biological and pathophysiological relevance, as well as its value as a potential pharmacodynamic biomarker for anticancer therapies.     

Hatching chronology of Blue Grouse in northeastern Oregon

Hatching chronology of Blue Grouse ( Dendragapus obscurus ) in northeastern Oregon was determined from 431 immatures examined from 1981 to 1985. Young hatched from 1 May through 8 July; median hatching dates for the five years ranged from 27 May to 5 June. Peak hatching in Oregon occurred from one to four weeks earlier than in most portions of the range of Blue Grouse but were similar to north central Washington and Idaho. Variations in hatching dates possibly were related to rainfall.       

Quantum annealing with manufactured spins

Many interesting but practically intractable problems can be reduced to that of finding the ground state of a system of interacting spins; however, finding such a ground state remains computationally difficult. It is believed that the ground state of some naturally occurring spin systems can be effectively attained through a process called quantum annealing. If it could be harnessed, quantum annealing might improve on known methods for solving certain types of problem. However, physical investigation of quantum annealing has been largely confined to microscopic spins in condensed-matter systems. Here we use quantum annealing to find the ground state of an artificial Ising spin system comprising an array of eight superconducting flux quantum bits with programmable spin-spin couplings. We observe a clear signature of quantum annealing, distinguishable from classical thermal annealing through the temperature dependence of the time at which the system dynamics freezes. Our implementation can be configured in situ to realize a wide variety of different spin networks, each of which can be monitored as it moves towards a low-energy configuration. This programmable artificial spin network bridges the gap between the theoretical study of ideal isolated spin networks and the experimental investigation of bulk magnetic samples. Moreover, with an increased number of spins, such a system may provide a practical physical means to implement a quantum algorithm, possibly allowing more-effective approaches to solving certain classes of hard combinatorial optimization problems.