Very low inheritance in cosmogenic surface exposure ages of glacial deposits: A field experiment from two Norwegian glacier forelands

Terrestrial cosmogenic nuclide dating has been widely used to estimate the surface exposure age of bedrock and boulder surfaces associated with deglaciation and Holocene glacier variations, but the effect of inherited age has been rarely directly addressed. In this study, small clasts, embedded in flute surfaces on two cirque glacier forelands in Jotunheimen, southern Norway and deposited within the last ~60 years, were used to test whether such clasts have the modern surface exposure age expected in the absence of inheritance. Two different approaches were taken involving dating of (1) a single clast of cobble size from the proglacial area of Austanbotnbreen, and (2) 75 clasts mostly of pebble size from the proglacial area of Storbreen crushed and treated as a single sample. 10Be surface exposure ages were 99 ± 98 and 368 ± 90 years, respectively, with 95% confidence (±2σ). It is concluded that (1) these small glaciers have eroded and deposited rock fragments with a cosmogenic zero or near-zero concentration, (2) the likelihood of inherited cosmogenic nuclide concentrations in similar rock fragments deposited by larger warm-based glaciers and ice sheets should be small, and (3) combining a large number of small rock particles into one sample rather than using single large clasts of boulder size may provide a viable alternative to the commonly perceived need for five or more independent estimates of exposure age per site

Alien Registration- Matthews, John A. (Howland, Penobscot County)

https://digitalmaine.com/alien_docs/7907/thumbnail.jp

The economy and efficiency of a milking machine

Industry has progressed considerably in substituting mechanical appliances for hand labor, thereby vastly reducing unit production costs. In more recent years agriculture has been making wider uses of mechanical equipment with the result that production has been increased, altho the proportion of agricultural laborers has markedly declined. Kinsman1 states that within the last 75 years a man\u27s ability as a field worker on the farm has been trebled. As the future of agriculture is studied it seems likely that the greatest opportunity for reducing production costs is to increase the output per man thru mechanical equipment. It is with a hope of lessening labor costs that mechanical milkers are now being installed on numerous dairy farms

The Last (Koy-Yukon) Interglaciation in the Northern Yukon: Evidence from Unit 4 at Ch’ijee’s Bluff, Bluefish Basin

The effects of predicted anthropogenic warming can be assessed in part by documenting responses to past warming events. One of the most pronounced warmings was the last interglaciation - stage 5 of the marine isotope record. A large multinational and multidisciplinary project (CELIA) was launched recently in order to gain detailed knowledge of the climate during stage 5. Several key exposures were identified by CELIA; one of them is Ch'ijee's Bluff on the Porcupine River, northern Yukon. Pollen, plant and insect macrofossils and stratigraphie evidence from Ch'ijee's Bluff show that the part of Ch'ijee's Unit 4 that is above and younger than Old Crow tephra (OCt) was deposited during an interval of climate warmer than present. When OCt was dated at 85 ka BP, the subsequent warming interval was presumed to be correlative with the early part of marine isotope stage 3. New dates on OCt show it to be 140-150 ka BP, and this means that the warm interval discussed here is more likely of stage 5 than stage 3 age. We apply the informal epithet, "Koy-Yukon interglaciation", to it and compare the Ch'ijee's Bluff Unit 4 sequence with other east Beringian sites that contain both Old Crow tephra and putative interglacial deposits.Les conséquences du réchauffement anthropique attendu pourraient en partie être évaluées à partir de nos connaissances sur les réchauffements climatiques antérieurs. Le réchauffement climatique le plus important s'est produit au cours du dernier interglaciaire (stade isotopique 5). Dans le but d'acquérir une meilleure connaissance du climat durant le stade 5, on a créé un important projet multidisciplinaire et multinational (CELIA). On a identifié plusieurs coupes clés dont celle de Ch'ijee's Bluff, de la Porcupine River, dans le nord du Yukon. Les indices fournis par le pollen, les végétaux, les macrofossiles d'insectes et la stratigraphie de Ch'ijee's Bluff démontrent que la partie de l'unité n 4 plus jeune que le tephra de Old Crow et située au-dessus a été déposée durant un intervalle plus chaud qu'aujourd'hui. Quand on a daté à 85 ka BP le tephra de Old Crow, on présumait que l'intervalle de réchauffement subséquent était corrélatif au stade isotopique 3, Les nouvelles dates le font maintenant remonter à 140-150 ka BP, ce qui signifie que le réchauffement climatique appartient plutôt au stade 5. On lui a attribué le nom informel de « interglaciaire de Koy-Yukon ». On a comparé la séquence de l'unité n 4 avec celle d'autres sites de Béringie qui renferment à la fois le tephra de Old Crow et des dépôts considérés comme étant interglaciaires.Die Auswirkungen einer erwarteten anthropogenen Erwàrmung kann man teilweise abschâtzen, indem man die Ergebnisse vergangener klimatischer Erwârmungen dokumentiert. Eine der herausragendsten klimatischen Erwârmungen war die letzte Interglazialzeit - Stadium 5 des marinen Isotop-Belegs. Kùrzlich hat man ein breitangelegtes multinationales und multidisziplinàres Projekt (CELIA) gestartet, um detaillierte Kenntnis ùber das Klima wàhrend des Stadium 5 zu erhalten. CELIA hat mehrere Schlussel-Schnitte identifiziert; einer davon ist Ch'ijee's Bluff am Porcupine River, nôrdliches Yukon. Die von Pollen, Pflanzen, Insektenmakrofossilen und Stratigraphie von Ch'ijee's Bluff gelieferten Anhaltspunkte zeigen, dass der Teil der Ch'ijee's-Einheit 4, der ùber Old Crow Tephra (OCt) liegt und jùnger ist, wâhrend eines klimatischen Intervalls. das warmer war als gengewârtig, abgelagert wurde. AIs man OCt auf 85 ka v. u. Z. datierte. nahm man an. dass das folgende Erwàrmungs-lntervall mit dem frùhen Teil des marinen Isotop-Stadiums 3 korrelierte. Neue Daten auf OCt zeigen, dass dieses 140-150 ka v. u. Z. ait ist, und das bedeutet, dass das warme Intervall, von dem hier die Rede ist. wohl eher dem Stadium 5 als dem Stadium 3 zugehôrt. Wir benutzen die informelle Bezeichnung "Koy-Yukon Interglazialzeit" und vergleichen die Ch'ijee's Bluff 4-Sequenz mit anderen Plâtzen von Ost-Bering, die sowohl Old Crow Tephra enthalten wie auch Ablagerungen, die man fur interglaziale Ablagerungen hait

Ariel - Volume 7 Number 2

Editors Mark Dembert Frank Chervanek John Lammie Jim Burke Curt Cumming

Na(v )1.8-null mice show stimulus-dependent deficits in spinal neuronal activity

BACKGROUND: The voltage gated sodium channel Na(v )1.8 has a highly restricted expression pattern to predominantly nociceptive peripheral sensory neurones. Behaviourally Na(v )1.8-null mice show an increased acute pain threshold to noxious mechanical pressure and also deficits in inflammatory and visceral, but not neuropathic pain. Here we have made in vivo electrophysiology recordings of dorsal horn neurones in intact anaesthetised Na(v )1.8-null mice, in response to a wide range of stimuli to further the understanding of the functional roles of Na(v )1.8 in pain transmission from the periphery to the spinal cord. RESULTS: Na(v )1.8-null mice showed marked deficits in the coding by dorsal horn neurones to mechanical, but not thermal, -evoked responses over the non-noxious and noxious range compared to littermate controls. Additionally, responses evoked to other stimulus modalities were also significantly reduced in Na(v )1.8-null mice where the reduction observed to pinch > brush. The occurrence of ongoing spontaneous neuronal activity was significantly less in mice lacking Na(v )1.8 compared to control. No difference was observed between groups in the evoked activity to electrical activity of the peripheral receptive field. CONCLUSION: This study demonstrates that deletion of the sodium channel Na(v )1.8 results in stimulus-dependent deficits in the dorsal horn neuronal coding to mechanical, but not thermal stimuli applied to the neuronal peripheral receptive field. This implies that Na(v )1.8 is either responsible for, or associated with proteins involved in mechanosensation

Existence and stability of singular patterns in a Ginzburg–Landau equation coupled with a mean field

We study singular patterns in a particular system of parabolic partial differential equations which consist of a Ginzburg–Landau equation and a mean field equation. We prove the existence of the three simplest concentrated periodic stationary patterns (single spikes, double spikes, double transition layers) by composing them of more elementary patterns and solving the corresponding consistency conditions. In the case of spike patterns we prove stability for sufficiently large spatial periods by first showing that the eigenvalues do not tend to zero as the period goes to infinity and then passing in the limit to a nonlocal eigenvalue problem which can be studied explicitly. For the two other patterns we show instability by using the variational characterization of eigenvalues

Continuous-Valued Binary Decision Procedures

Conditions have been given elsewhere which guarantee that binary decision procedures have a simple structure. Here we show that a continuity requirement together with some weak algebraic regularity conditions ensures that a binary procedure is locally simple. Additional topological assumptions are given which require that the binary procedure is a simple game