Postglacial Isobases from Northern Ellesmere Island and Greenland: New Data

Over seventy new 14C dates on former relative sea levels from Hall Land, northwest Greenland, and Clements Markham Inlet, northern Ellesmere Island, are combined with previous data to revise the regional isobases for this area. These isobases show : 1) a centre of maximum postglacial emergence over northwest Greenland extending to; 2) an intervening cell of lower emergence over northeast Ellesmere Island which was isostatically-dominated by the Greenland Ice Sheet; in turn, extending to 3) a higher centre of emergence over the Grant Land Mountains, northernmost Ellesmere Island, associated with the independent history of local ice caps there. Radiocarbon dates from raised marine shorelines show a 2000 year lag between glacial unloading on northwest Greenland and northernmost Ellesmere Island. This lag in glacioisostatic adjustments suggests a considerable range in the glacier response times and/or glacioclimatic regimes in this area. Throughout the area the last ice limit was ca. 5-60 km beyond present ice margins. Maximum emergence at these ice limits is marked by shorelines built into a full glacial sea which range from 124 m asl in Clements Markham Inlet to 150 m asl in Hall Land. This indicates that similar emergence (120-150 m) in other areas does not necessarily require the removal of entire ice sheets although this has been commonly assumed in the literature. The geophysical implications of this warrant consideration.Plus de 70 nouvelles datations au radiocarbone effectuées sur d'anciens niveaux marins, sur la terre de Hall (nord-ouest du Groenland) et dans la baie de Clements Markham (nord de l'île d'Ellesmere), ont été associées aux données déjà recueillies et permettent de réviser les isobases de la région. Celles-ci révèlent: 1) un centre d'émersion postglaciaire maximale au nord-ouest du Groenland qui s'étend jusqu'à 2) un compartiment de faible relèvement dans le nord-est de l'île d'Ellesmere, couvert par l'inlandsis du Groenland qui s'étendait jusqu'à 3) un centre d'émersion plus importante à l'endroit des Grant Land Mountains, à l'extrême nord de l'île d'Ellesmere, associée à révolution des calottes glaciaires locales. La datation au radiocarbone de lignes de rivage soulevées révèle un décalage de 2000 ans entre le retrait glaciaire qu'a connu l'extrême nord d'Ellesmere et celui qu'a connu le nord-ouest du Groenland. Ce décalage entre les rajustements glacioisostatiques laisse entrevoir une grande variation dans le temps de réaction du glacier et dans les régimes glacioclimatiques de la région. Partout la dernière limite glaciaire se situe de 40 à 60 km au-delà des marges glaciaires actuelles. L'émersion maximale près de cette limite est marquée par des lignes de rivage construites en pleine mer glaciaire, qui vont de 124 m anm, dans la baie de Clements Markham, à 150 m anm, sur la terre de Hall. Ceci révèle qu'ailleurs une emersion de cet ordre, soit de 120 à 150 m, ne suppose pas nécessairement le retrait de toute la calotte glaciaire, bien que cette idée soit généralement acceptée. Les conséquences géophysiques qui en découlent exigent désormais qu'on en tienne compte.Ùber 70 neue 14C Daten ùberfrùhere relative Meeresspiegel von Hall Land, Nordwest-Grônland und der Clements Markham Bucht, nôrdliche Ellesmere-lnsel, werden mit schon vorhandenen Daten kombiniert, um die regionalen Isobasen fur dieses Gebiet zu revidieren. Dièse Isobasen zeigen : 1) ein Zentrum des maximalen postglazialen Auftauchens ùber Nordwest-Grônland, welches sich ausdehnt zu 2) einem dazwischenliegenden Gelàndeabschnitt mit niedrigerem Auftauchen ùber dem Nordosten der Ellesmere-lnsel, welcher isostatisch durch die Grônland Eiskappe dominiert wurde; welcher seinerseits sich zu 3) einem hôheren Auftauchzentrum ùber den Grant Land Mountains ausdehnte, im àuBersten Norden der Ellesmere-lnsel, das mit der unabhângigen Geschichte der dortigen lokalen Eiskappen in Verbindung gebracht wird. Radiokarbon-Daten der gehobenen marinen Kùstenlinien zeigen einen Zeitunterschied von 2000 Jahren zwischen dem glazialen Rùckzug im Nordwesten von Grônland und dem im àuBersten Norden der Ellesmere-lnsel. Dieser Zeitunterschied in den glazialisostatischen Anpassungen IaBt eine erhebliche Schwankung in der Reaktionszeit des Gletschers und/ oder glazialklimatischen Systemen in diesem Gebiet vermuten. In diesem ganzen Gebiet ging die âuBerste Eisgrenze etwa 40-60 km ùber die heitigen Eisgrenzen hinaus. Das maximale Auftauchen an diesen Eisgrenzen ist durch Kùstenlinien markiert, die in ein voiles glaziales Eismeer hineingebaut sind und welche von 124 m ùber dem Meeresspiegel in der Bucht von Clements Markham bis zu 150 m ùber dem Meeresspiegel in Hall Land reichen. Das zeigt, daB ein vergleichbares Auftauchen (120-150 m) in anderen Gebieten nicht unbedingt den Rùckzug der ganzen Eiskappen erfordert, auch wenn dies allge-mein in der Fachliteratur angenommen wurde

A Visual Library for the Geosciences

This project developed a digital library of annotated photographs of geological specimens which has been integrated with the Department of Geology's existing Blackboard resources. The library is available 24/7 enabling students to use it for enhanced learning, reference and revision. Images are downloadable to mobile devices (e.g. phones and mp3 players) and can be used for reference by students in the field. Difficulties were experienced with colour balancing in the photographs (which in some cases made the material difficult to recognize) and representing 3D patterns on 2D images. However, the students found the material a useful addition to the online materials and the library could be packaged for distribution outside Blackboard. This will require further, ongoing work

Atlantic Ocean Heat Transport Enabled by Indo-Pacific Heat Uptake and Mixing

The ocean transports vast amounts of heat around the planet, helping to regulate regional climate. One important component of this heat transport is the movement of warm water from equatorial regions toward the poles, with colder water flowing in return. Here, we introduce a framework relating meridional heat transport to the diabatic processes of surface forcing and turbulent mixing that move heat across temperature classes. Applied to a (1/4)° global ocean model the framework highlights the role of the tropical Indo‐Pacific in the global ocean heat transport. A large fraction of the northward heat transport in the Atlantic is ultimately sourced from heat uptake in the eastern tropical Pacific. Turbulent mixing moves heat from the warm, shallow Indo‐Pacific circulation to the cold deeper‐reaching Atlantic circulation. Our results underscore a renewed focus on the tropical oceans and their role in global circulation pathways

Atlantic Ocean Heat Transport Enabled by Indo-Pacific Heat Uptake and Mixing

The ocean transports vast amounts of heat around the planet, helping to regulate regional climate. One important component of this heat transport is the movement of warm water from equatorial regions toward the poles, with colder water flowing in return. Here, we introduce a framework relating meridional heat transport to the diabatic processes of surface forcing and turbulent mixing that move heat across temperature classes. Applied to a (1/4)° global ocean model the framework highlights the role of the tropical Indo‐Pacific in the global ocean heat transport. A large fraction of the northward heat transport in the Atlantic is ultimately sourced from heat uptake in the eastern tropical Pacific. Turbulent mixing moves heat from the warm, shallow Indo‐Pacific circulation to the cold deeper‐reaching Atlantic circulation. Our results underscore a renewed focus on the tropical oceans and their role in global circulation pathways

BMQ

BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals

Loss-of-Function Variants in DRD1 in Infantile Parkinsonism-Dystonia

The human dopaminergic system is vital for a broad range of neurological processes, including the control of voluntary movement. Here we report a proband presenting with clinical features of dopamine deficiency: severe infantile parkinsonism-dystonia, characterised by frequent oculogyric crises, dysautonomia and global neurodevelopmental impairment. CSF neurotransmitter analysis was unexpectedly normal. Triome whole-genome sequencing revealed a homozygous variant (c.110C>A, (p.T37K)) in DRD1, encoding the most abundant dopamine receptor (D1) in the central nervous system, most highly expressed in the striatum. This variant was absent from gnomAD, with a CADD score of 27.5. Using an in vitro heterologous expression system, we determined that DRD1-T37K results in loss of protein function. Structure-function modelling studies predicted reduced substrate binding, which was confirmed in vitro. Exposure of mutant protein to the selective D1 agonist Chloro APB resulted in significantly reduced cyclic AMP levels. Numerous D1 agonists failed to rescue the cellular defect, reflected clinically in the patient, who had no benefit from dopaminergic therapy. Our study identifies DRD1 as a new disease-associated gene, suggesting a crucial role for the D1 receptor in motor control

Environmental risk factors in puppies and kittens for developing chronic disorders in adulthood: A call for research on developmental programming

Many dogs and cats are affected by chronic diseases that significantly impact their health and welfare and relationships with humans. Some of these diseases can be challenging to treat, and a better understanding of early-life risk factors for diseases occurring in adulthood is key to improving preventive veterinary care and husbandry practices. This article reviews early-life risk factors for obesity and chronic enteropathy, and for chronic behavioral problems, which can also be intractable with life-changing consequences. Aspects of early life in puppies and kittens that can impact the risk of adult disorders include maternal nutrition, establishment of the gut microbiome, maternal behavior, weaning, nutrition during growth, growth rate, socialization with conspecifics and humans, rehoming and neutering. Despite evidence in some species that the disorders reviewed here reflect the developmental origins of health and disease (DOHaD), developmental programming has rarely been studied in dogs and cats. Priorities and strategies to increase knowledge of early-life risk factors and DOHaD in dogs and cats are discussed. Critical windows of development are proposed: preconception, gestation, the suckling period, early growth pre-neutering or pre-puberty, and growth post-neutering or post-puberty to adult size, the durations of which depend upon species and breed. Challenges to DOHaD research in these species include a large number of breeds with wide genetic and phenotypic variability, and the existence of many mixed-breed individuals. Moreover, difficulties in conducting prospective lifelong cohort studies are exacerbated by discontinuity in pet husbandry between breeders and subsequent owners, and by the dispersed nature of pet ownership

Last millennium northern hemisphere summer temperatures from tree rings: Part I: The long term context

Large-scale millennial length Northern Hemisphere (NH) temperature reconstructions have been progressively improved over the last 20 years as new datasets have been developed. This paper, and its companion (Part II, Anchukaitis et al. in prep), details the latest tree-ring (TR) based NH land air temperature reconstruction from a temporal and spatial perspective. This work is the first product of a consortium called N-TREND (Northern Hemisphere Tree-Ring Network Development) which brings together dendroclimatologists to identify a collective strategy for improving large-scale summer temperature reconstructions. The new reconstruction, N-TREND2015, utilises 54 records, a significant expansion compared with previous TR studies, and yields an improved reconstruction with stronger statistical calibration metrics. N-TREND2015 is relatively insensitive to the compositing method and spatial weighting used and validation metrics indicate that the new record portrays reasonable coherence with large scale summer temperatures and is robust at all time-scales from 918 to 2004 where at least 3 TR records exist from each major continental mass. N-TREND2015 indicates a longer and warmer medieval period (∼900–1170) than portrayed by previous TR NH reconstructions and by the CMIP5 model ensemble, but with better overall agreement between records for the last 600 years. Future dendroclimatic projects should focus on developing new long records from data-sparse regions such as North America and eastern Eurasia as well as ensuring the measurement of parameters related to latewood density to complement ring-width records which can improve local based calibration substantially