scholarly journals Recent Developments in Calibration for Archaeological and Environmental Samples

Radiocarbon ◽  
2020 ◽  
Vol 62 (4) ◽  
pp. 1095-1117 ◽  
Author(s):  
J van der Plicht ◽  
C Bronk Ramsey ◽  
T J Heaton ◽  
E M Scott ◽  
S Talamo
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Tree Rings ◽  
Environmental Samples ◽  
Varved Sediments ◽  
Companion Article ◽  
Recent Developments ◽  
General Readership ◽  
Paleolithic Archaeology ◽  
Insight Into

ABSTRACTThe curves recommended for calibrating radiocarbon (14C) dates into absolute dates have been updated. For calibrating atmospheric samples from the Northern Hemisphere, the new curve is called IntCal20. This is accompanied by associated curves SHCal20 for the Southern Hemisphere, and Marine20 for marine samples. In this “companion article” we discuss advances and developments that have led to improvements in the updated curves and highlight some issues of relevance for the general readership. In particular the dendrochronological based part of the curve has seen a significant increase in data, with single-year resolution for certain time ranges, extending back to 13,910 calBP. Beyond the tree rings, the new curve is based upon an updated combination of marine corals, speleothems, macrofossils, and varved sediments and now reaches back to 55,000 calBP. Alongside these data advances, we have developed a new, bespoke statistical curve construction methodology to allow better incorporation of the diverse constituent records and produce a more robust curve with uncertainties. Combined, these data and methodological advances offer the potential for significant new insight into our past. We discuss some implications for the user, such as the dating of the Santorini eruption and also some consequences of the new curve for Paleolithic archaeology.

ATMOSPHERIC RADIOCARBON FOR THE PERIOD 1950–2019

Radiocarbon ◽  
2021 ◽  
pp. 1-23
Author(s):  
Quan Hua ◽  
Jocelyn C Turnbull ◽  
Guaciara M Santos ◽  
Andrzej Z Rakowski ◽  
Santiago Ancapichún ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Tree Rings ◽  
Data Sets ◽  
Previous Approach ◽  
Monthly Data ◽  
Smooth Curves ◽  
Clean Air ◽  
Increasing Demand

ABSTRACT This paper presents a compilation of atmospheric radiocarbon for the period 1950–2019, derived from atmospheric CO2 sampling and tree rings from clean-air sites. Following the approach taken by Hua et al. (2013), our revised and extended compilation consists of zonal, hemispheric and global radiocarbon (14C) data sets, with monthly data sets for 5 zones (Northern Hemisphere zones 1, 2, and 3, and Southern Hemisphere zones 3 and 1–2). Our new compilation includes smooth curves for zonal data sets that are more suitable for dating applications than the previous approach based on simple averaging. Our new radiocarbon dataset is intended to help facilitate the use of atmospheric bomb 14C in carbon cycle studies and to accommodate increasing demand for accurate dating of recent (post-1950) terrestrial samples.

A deeper insight into the dynamics and effects of the Hiccup of the fall transition

2021 ◽  
Author(s):  
Vivien Matthias ◽  
Daniela Banys ◽  
Marc Hansen
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Zonal Wind ◽  
Middle Atmosphere ◽  
3D Structure ◽  
Reanalysis Data ◽  
Wind Regime ◽  
Altitudinal Shift ◽  
D Region ◽  
Insight Into

<p>In autumn the prevailing wind in the middle atmosphere at mid and high latitudes changes from summer easterly to winter westerly.  This process is not smooth but interrupted by the Hiccup of the fall transition with characteristics similar to a mini sudden stratospheric warming (SSW) which occurs in fall even though the zonal mean zonal wind does not reverse to easterly again. Combining global reanalysis data and satellite observations we improve our knowledge and understanding of the dynamics of the Hiccup of the fall transition in the middle atmosphere. The introduction of a new definition for the onset of the Hiccup focusing now on its core region in the lower mesosphere allows us the automatic detection of a Hiccup in almost every year and thus a deeper insight into its dynamics. For example, we found a latitudinal and altitudinal shift in the zonal wind regime during the Hiccup. We also investigate its 3D-structure and compare the characteristics of the Hiccup in the Northern hemisphere with those in the Southern hemisphere. We found that the latitudinal and altitudinal shift of the zonal wind regime occurs in both hemispheres but is more pronounced in the Northern hemisphere and smoother in the Southern hemisphere.  Additionally, we discuss the possible impact of the Hiccup on the D-region.</p>

scholarly journals 14C Calibration in the Southern Hemisphere and the Date of the Last Taupo Eruption: Evidence from Tree-Ring Sequences

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 155-163 ◽  
Author(s):  
R. J. Sparks ◽  
W. H. Melhuish ◽  
J.W. A. McKee ◽  
John Ogden ◽  
J. G. Palmer ◽  
...  
Keyword(s):  
New Zealand ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Tree Ring ◽  
Tree Rings ◽  
Calibration Curve ◽  
Systematic Difference ◽  
Calibration Data ◽  
Northern And Southern Hemispheres

Tree rings from a section of Prumnopitys taxifolia (matai) covering the period ad 1335–1745 have been radiocarbon dated and used to generate a 14C calibration curve for southern hemisphere wood. Comparison of this curve with calibration data for northern hemisphere wood does not show a systematic difference between 14C ages measured in the northern and southern hemispheres. A floating chronology covering 270 yr and terminating at the last Taupo (New Zealand) eruption, derived from a sequence of 10-yr samples of tree rings from Phyllocladus trichomanoides (celery pine, or tanekaha), is also consistent with the absence of a systematic north-south difference, and together with the matai data, fixes the date of the Taupo eruption at ad 232 ± 15.

Alpha-Effect, Current and Kinetic Helicities for Magnetically Driven Turbulence, and Solar Dynamo

2000 ◽  
Vol 179 ◽  
pp. 387-388
Author(s):  
Gaetano Belvedere ◽  
V. V. Pipin ◽  
G. Rüdiger
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Convection Zone ◽  
Solar Surface ◽  
Momentum Transport ◽  
Angular Momentum Transport ◽  
Magnetic Buoyancy ◽  
Alpha Effect ◽  
Current Helicity

Extended AbstractRecent numerical simulations lead to the result that turbulence is much more magnetically driven than believed. In particular the role ofmagnetic buoyancyappears quite important for the generation ofα-effect and angular momentum transport (Brandenburg & Schmitt 1998). We present results obtained for a turbulence field driven by a (given) Lorentz force in a non-stratified but rotating convection zone. The main result confirms the numerical findings of Brandenburg & Schmitt that in the northern hemisphere theα-effect and the kinetic helicityℋkin= 〈u′ · rotu′〉 are positive (and negative in the northern hemisphere), this being just opposite to what occurs for the current helicityℋcurr= 〈j′ ·B′〉, which is negative in the northern hemisphere (and positive in the southern hemisphere). There has been an increasing number of papers presenting observations of current helicity at the solar surface, all showing that it isnegativein the northern hemisphere and positive in the southern hemisphere (see Rüdigeret al. 2000, also for a review).

The Hemispheric Sign Rule of Current Helicity during the Rising Phase of Cycle 23

2000 ◽  
Vol 179 ◽  
pp. 303-306
Author(s):  
S. D. Bao ◽  
G. X. Ai ◽  
H. Q. Zhang
Keyword(s):  
Solar Cycle ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Active Regions ◽  
Hemispheric Preference ◽  
Current Helicity

AbstractWe compute the signs of two different current helicity parameters (i.e., αbestandHc) for 87 active regions during the rise of cycle 23. The results indicate that 59% of the active regions in the northern hemisphere have negative αbestand 65% in the southern hemisphere have positive. This is consistent with that of the cycle 22. However, the helicity parameterHcshows a weaker opposite hemispheric preference in the new solar cycle. Possible reasons are discussed.

No fear of George Kingsley Zipf

10.1558/37291 ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 242-263
Author(s):  
Stefano Rastelli ◽  
Kook-Hee Gil
Keyword(s):  
Minimalist Program ◽  
Classroom Research ◽  
Language Design ◽  
Efficient Computation ◽  
Generative Linguistics ◽  
The Third ◽  
Factor Effect ◽  
Language Classroom ◽  
Recent Developments ◽  
Insight Into

This paper offers a new insight into GenSLA classroom research in light of recent developments in the Minimalist Program (MP). Recent research in GenSLA has shown how generative linguistics and acquisition studies can inform the language classroom, mostly focusing on what linguistic aspects of target properties should be integrated as a part of the classroom input. Based on insights from Chomsky’s ‘three factors for language design’ – which bring together the Faculty of Language, input and general principles of economy and efficient computation (the third factor effect) for language development – we put forward a theoretical rationale for how classroom research can offer a unique environment to test the learnability in L2 through the statistical enhancement of the input to which learners are exposed.

Green Synthesized Nanomaterials as Theranostic Platforms for Cancer Treatment: Principles, Challenges and the Road Ahead

2019 ◽  
Vol 26 (8) ◽  
pp. 1311-1327 ◽  
Author(s):  
Pala Rajasekharreddy ◽  
Chao Huang ◽  
Siddhardha Busi ◽  
Jobina Rajkumari ◽  
Ming-Hong Tai ◽  
...  
Keyword(s):  
Nanoparticle Synthesis ◽  
Research Field ◽  
Synthesis Methods ◽  
Synthetic Approach ◽  
Future Directions ◽  
The Road ◽  
New Methods ◽  
Recent Developments ◽  
Theranostic Applications ◽  
Insight Into

With the emergence of nanotechnology, new methods have been developed for engineering various nanoparticles for biomedical applications. Nanotheranostics is a burgeoning research field with tremendous prospects for the improvement of diagnosis and treatment of various cancers. However, the development of biocompatible and efficient drug/gene delivery theranostic systems still remains a challenge. Green synthetic approach of nanoparticles with low capital and operating expenses, reduced environmental pollution and better biocompatibility and stability is a latest and novel field, which is advantageous over chemical or physical nanoparticle synthesis methods. In this article, we summarize the recent research progresses related to green synthesized nanoparticles for cancer theranostic applications, and we also conclude with a look at the current challenges and insight into the future directions based on recent developments in these areas.

scholarly journals An overview of psychological and social factors in Charles Bonnet syndrome

2021 ◽  
Vol 13 ◽  
pp. 251584142110347
Author(s):  
Lee Jones ◽  
Lara Ditzel-Finn ◽  
Jamie Enoch ◽  
Mariya Moosajee
Keyword(s):  
Emotional Response ◽  
Causal Mechanism ◽  
Visual Hallucinations ◽  
Cognitively Normal ◽  
Charles Bonnet Syndrome ◽  
Raising Awareness ◽  
Normal Individuals ◽  
The Social ◽  
Recent Developments ◽  
Insight Into

Charles Bonnet syndrome (CBS) is a condition where cognitively normal individuals with sight impairment experience simple and/or complex visual hallucinations. The exact pathogenesis of CBS is unknown; however, deafferentation is often recognised as a causal mechanism. Studies have provided insight into the multifaceted impact of CBS on wellbeing. Onset of CBS may cause distress among those believing visual hallucinations are indicative of a neurological condition. Hallucinatory content is often congruent with the emotional response. For example, hallucinations of a macabre nature typically result in a fearful response. Visual hallucinations may be highly disruptive, causing everyday tasks to become challenging. Clinical management relies on forewarning and pre-emptive questioning. Yet, knowledge and awareness of CBS is typically low. In this review, we provide a summary of the social and psychological implications of CBS and explore recent developments aimed at raising awareness and improving patient management.

scholarly journals First results of low frequency electromagnetic wave detector of TC-2/Double Star program

2005 ◽  
Vol 23 (8) ◽  
pp. 2803-2811 ◽  
Author(s):  
J. B. Cao ◽  
Z. X. Liu ◽  
J. Y. Yang ◽  
C. X. Yian ◽  
Z. G. Wang ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Geomagnetic Storms ◽  
Low Frequency ◽  
Wave Detector ◽  
Ion Cyclotron Waves ◽  
Satellite Platform ◽  
Ion Cyclotron ◽  
First Results

Abstract. LFEW is a low frequency electromagnetic wave detector mounted on TC-2, which can measure the magnetic fluctuation of low frequency electromagnetic waves. The frequency range is 8 Hz to 10 kHz. LFEW comprises a boom-mounted, three-axis search coil magnetometer, a preamplifier and an electronics box that houses a Digital Spectrum Analyzer. LFEW was calibrated at Chambon-la-Forêt in France. The ground calibration results show that the performance of LFEW is similar to that of STAFF on TC-1. The first results of LFEW show that it works normally on board, and that the AC magnetic interference of the satellite platform is very small. In the plasmasphere, LFEW observed the ion cyclotron waves. During the geomagnetic storm on 8 November 2004, LFEW observed a wave burst associated with the oxygen ion cyclotron waves. This observation shows that during geomagnetic storms, the oxygen ions are very active in the inner magnetosphere. Outside the plasmasphere, LFEW observed the chorus on 3 November 2004. LFEW also observed the plasmaspheric hiss and mid-latitude hiss both in the Southern Hemisphere and Northern Hemisphere on 8 November 2004. The hiss in the Southern Hemisphere may be the reflected waves of the hiss in the Northern Hemisphere.

On a possible geological cause of changes in the position of the axis of the earth's crust

1867 ◽  
Vol 15 ◽  
pp. 46-54 ◽  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Earth’S Crust ◽  
The Subject ◽  
Earth's Crust ◽  
Geological Observation

At a time when the causes which have led to climatal changes in various parts of the globe are the subject of so much discussion, but little apology is needed for calling the attention of this Society to what possibly may have been one of these causes, though it has apparently hitherto escaped observation. That great changes of climate have taken place, at all events in the northern hemisphere of the globe, is one of the best established facts of geology, and that corresponding changes have not been noticed to the same extent in the southern hemisphere may possibly be considered as due, rather to a more limited amount of geological observation, than to an absence of the phenomena indicative of such alterations in climatal con­ditions having occurred.

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