Building a model of a useful Turing machine

AbstractThe principal ideas of a universal computer are gradually introduced into a functional model of the Turing machine. The strict sequentiality of this model is confronted with parallelism observed in real computers.This paper follows up the presentation [1] and is complemented by [2,3]

Formal ratification of subseries for the Pleistocene Series of the Quaternary System

The Pleistocene Series/Epoch of the Quaternary System/ Period has been divided unofficially into three subseries/ subepochs since at least the 1870s. On 30th January, 2020, the Executive Committee of the International Union of Geological Sciences ratified two proposals approved by the International Commission on Stratigraphy formalizing: 1) the Lower Pleistocene Subseries, comprising the Gelasian Stage and the superjacent Calabrian Stage, with a base defined by the GSSP for the Gelasian Stage, the Pleistocene Series, and the Quaternary System, and currently dated at 2.58 Ma; and 2) the term Upper Pleistocene, at the rank of subseries, with a base currently undefined but provisionally dated at ~129 ka. Defining the Upper Pleistocene Subseries and its corresponding stage with a GSSP is in progress. The Middle Pleistocene Subseries is defined by the recently ratified GSSP for the Chibanian Stage currently dated at 0.774 Ma. These ratifications complete the official division of the Pleistocene into three subseries/ subepochs, in uniformity with the similarly subdivided Holocene Series/Epoch.</p

Standardized postnatal management of infants with congenital diaphragmatic hernia in Europe: The CDH EURO Consortium Consensus - 2015 Update

In 2010, the congenital diaphragmatic hernia (CDH) EURO Consortium published a standardized neonatal treatment protocol. Five years later, the number of participating centers has been raised from 13 to 22. In this article the relevant literature is updated, and consensus has been reached between the members of the CDH EURO Consortium. Key updated recommendations are: (1) planned delivery after a gestational age of 39 weeks in a high-volume tertiary center; (2) neuromuscular blocking agents to be avoided during initial treatment in the delivery room; (3) adapt treatment to reach a preductal saturation of between 80 and 95% and postductal saturation >70%; (4) target PaCO2 to be between 50 and 70 mm Hg; (5) conventional mechanical ventilation to be the optimal initial ventilation strategy, and (6) intravenous sildenafil to be considered in CDH patients with severe pulmonary hypertension. This article represents the current opinion of all consortium members in Europe for the optimal neonatal treatment of CDH

The chemical compound 'Heatin' stimulates hypocotyl elongation and interferes with the Arabidopsis NIT1-subfamily of nitrilases

Temperature passively affects biological processes involved in plant growth. Therefore, it is challenging to study the dedicated temperature signalling pathways that orchestrate thermomorphogenesis, a suite of elongation growth-based adaptations that enhance leaf-cooling capacity. We screened a chemical library for compounds that restored hypocotyl elongation in the pif4-2-deficient mutant background at warm temperature conditions in Arabidopsis thaliana to identify modulators of thermomorphogenesis. The small aromatic compound 'Heatin', containing 1-iminomethyl-2-naphthol as a pharmacophore, was selected as an enhancer of elongation growth. We show that ARABIDOPSIS ALDEHYDE OXIDASES redundantly contribute to Heatin-mediated hypocotyl elongation. Following a chemical proteomics approach, the members of the NITRILASE1-subfamily of auxin biosynthesis enzymes were identified among the molecular targets of Heatin. Our data reveal that nitrilases are involved in promotion of hypocotyl elongation in response to high temperature and Heatin-mediated hypocotyl elongation requires the NITRILASE1-subfamily members, NIT1 and NIT2. Heatin inhibits NIT1-subfamily enzymatic activity in vitro and the application of Heatin accordingly results in the accumulation of NIT1-subfamily substrate indole-3-acetonitrile in vivo. However, levels of the NIT1-subfamily product, bioactive auxin (indole-3-acetic acid), were also significantly increased. It is likely that the stimulation of hypocotyl elongation by Heatin might be independent of its observed interaction with NITRILASE1-subfamily members. However, nitrilases may contribute to the Heatin response by stimulating indole-3-acetic acid biosynthesis in an indirect way. Heatin and its functional analogues present novel chemical entities for studying auxin biology

Quartaer- und hydrogeologische Untersuchungen im Bereich der Bornhoeveder Seenkette, Schleswig-Holstein

With 41 figs., 8 tabs.SIGLEAvailable from TIB Hannover: RA6759(43) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Discriminating between subglacial and proglacial lake sediments: an example from the Dänischer Wohld Peninsula, northern Germany

Subglacial lakes are common features of contemporary ice masses. However, they are rarely identified in the geological record. This is due to the difficulty in discriminating between subglacial and proglacial lake sediments; a proglacial origin is typically preferred as the ‘simplest’ explanation. We hypothesise that numerous deposits currently interpreted to record proglacial lake sedimentation may actually have a subglacial origin. Here we try and find ways of distinguishing proglacial from subglacial lake sediments by investigating three sites along the Dänischer Wohld Peninsula, northern Germany, which have been interpreted to record both proglacial and subglacial sedimentation. We identify two major phases of ice activity and associated lake formation during the Late Weichselian glaciation. (1) Proglacial lake formation at ∼23 ka in front of the advancing Baltic Ice Stream. This lake was subsequently overridden and the sediments glaciotectonised as ice continued to advance to its maximum extent. (2) Retreat of ice back into the Baltic Basin at ∼19 ka and formation of a proglacial lake that persisted for ∼4 ka. We suggest that subglacial lake activity may have occurred at two of the sites between 23 and 19 ka. This is based on the presence of aggrading sediment deposits characterised by stratified/laminated diamictons and interbedded tabular to channelized sorted sediments, the juxtaposition of relatively undeformed waterlain sediment and subglacial till, absence of glaciotectonic thrusting and folding or of fining/coarsening successions and the geomorphic association with tunnel valleys to the south of the study area. The style of sedimentation and deformation provided the greatest insight into the discrimination of proglacially vs subglacially deposited glaciolacustrine sediments. The luminescence signal palaeodose distributions also offers a potentially powerful means of fingerprinting sediment transport pathways of young glacial systems

Methyl 2-cyanoacrylate

2-Cyjanoakrylan metylu (MCA) jest bezbarwną, lepką cieczą o charakterystycznym zapachu. Znajduje zastosowanie do produkcji różnego rodzaju klejów i polimerów. Informacje dotyczące toksyczności MCA u ludzi są fragmentaryczne. Z badań na ochotnikach wynika, że MCA o stężeniach 4,5÷270,0 mg/m3 wykazuje działanie drażniące na śluzówkę górnych dróg oddechowych i oczu. Długotrwałe narażenie na MCA może być przyczyną dermatoz. W dostępnym piśmiennictwie istnieją dane świadczące o tym, że narażenie na MCA może być przyczyną astmy zawodowej. Z drugiej strony, grupa WATCH (Working Group on the Assessment of Toxic Chemicals) uważa, że nie powinno się MCA i ECA uważać za czynniki astmogenne. Pogląd ten znajduje potwierdzenie w wynikach badań epidemiologicznych nad zależnością między częstością występowania astmy zawodowej a wielkością narażenia na cyjanoakrylany. Wśród narażonych na akrylany nie stwierdzono zwiększonego ryzyka zachorowalności na astmę. MCA w doświadczeniach na zwierzętach wykazuje małą toksyczność. DL50 dla szczurów po podaniu drogą pokarmową waha się w granicach 1600÷3200 mg/kg. Po narażeniu drogą inhalacyjną szczurów przez 12 tygodni stwierdzono jedynie spadek masy ciała po dawce 141 mg/m3. W warunkach zawodowych narażenie na MCA może nastąpić drogą oddechową i dermalną. MCA ulega metabolizmowi do formaldehydu i cyjanooctanu, a następnie do cyjanku i rodanku. W większości państw jako NDS przyjęto wartość 2 ppm (8÷9,2 mg/m3), a jako NDSCh – 4 ppm (16÷18 mg/m3). W 1997 r. ACGIH obniżyło wartość NDS do 0,2 ppm (1 mg/m3). Podstawą były wyniki badań, które wykazały, że przy stężeniu 2 ppm u badanych ochotników widoczne było działanie drażniące MCA na błony śluzowe nosa i gardła. Opierając się na tych badaniach proponuje się przyjąć dla 2-cyjanoakrylanu metylu wartość NDS równą 2 mg/m3 i wartość NDSCh – 4 mg/m3. Proponuje się również oznakowanie normatywu symbolem „I”. Nie ma podstaw do ustalenia wartości DSB.Methyl 2-cyanoacrylate (MCA) is clear, viscous liquid of characteristic irritating odour. It is used in the production of various kinds of glue and polymers. Information on MCA toxicity in humans is fragmentary. It results from tests on volunteers that MCA of 4,5÷270,0 mg/m3 concentration demonstrates irritating activity on upper airways and eyes mucosa. Long-term exposure to MCA may cause dermatoses. In available literature there are data proving that exposure to MCA may be the cause of occupational asthma. On the other hand, WATCH (Working Group on the Assessment of Toxic Chemicals) think that MCA and ECA should not be considered as asthmogenic factors. Their opinion finds confirmation in the results of epidemiologic studies on the dependence between the prevalence of occupational asthma and the range of the exposure to cyanoacrylates. No increased risk of incidence of asthma was found among subjects exposed to acrylates. In experiments on animals MCA demonstrates low toxicity. DL50 for rats after administration into alimentary tract was within the limit: 1600÷3200 mg/kg. After inhalatory exposure of rats throughout 12 weeks, only the decrease of body mass was observed after a dose of 141 mg/m3. In the occupational conditions exposure can occur by inhalation and skin. MCA metabolises to formaldehyde and cyanoacetate and then to cyanide and thiocyanate. In majority of countries the accepted NDS value is 2 ppm (8÷9,2 mg/m3) and NDSCh value - 4 ppm (16÷18 mg/m3). In 1997 ACGIH decreased NDS value to 0,2 ppm (1 mg/m3). The base were the results of studies which demonstrated that at the concentration of 2 ppm irritating activity of MCA on nasal mucosa was observed in the examined volunteers

Palaeo-ice streams: an introduction.

[FIRST PARAGRAPH] Ice streams are narrow fast-flowing zones within ice sheets, and in the case of Antarctica are responsible for draining up to 90% of the mass from the ice sheet. It has been shown that Quaternary ice sheets were profoundly, and arguably catastrophically, influenced by the operation of transitory ice streaming. The palaeo-ice stream that operated through Hudson Strait for example, destabilized the Laurentide Ice Sheet, changed its configuration and thickness, and the resultant iceberg melt cooled North Atlantic waters enough to alter ocean circulation and produce ~4°C flips in climate on abrupt time scales