Labrador Sea bio-, tephro-, oxygen isotopic stratigraphy and Late Quaternary paleoceanographic trends

1980 ◽  
Vol 17 (7) ◽  
pp. 831-854 ◽  
Author(s):  
R. H. Fillon ◽  
J. C. Duplessy
Keyword(s):  
Deep Water ◽  
Late Quaternary ◽  
Planktonic Foraminifera ◽  
Open Water ◽  
Labrador Sea ◽  
Surface Cooling ◽  
Stratigraphic Framework ◽  
Stage 4 ◽  
Oxygen Isotopic ◽  
Stage 1

A stratigraphic framework for eastern Labrador Sea cores has been developed for the interval 0–90 000 years BP through analysis of oxygen isotopes, volcanic ash, benthonic foraminifera, and the radiolarian Diplocyclas davisiana. Benthonic and planktonic foraminiferal isotope stratigraphy and the time scale of Shackleton and Opdyke provide a basis for the approximate dating of a series of marker events which include ash zones at ca. 59 000 and ≤ 21 000 years BP; benthonic foraminiferal abundance maxima at ca. 83 000, 75 000, 60 000, 19 000, and 3000 years BP; and D. davisiana percentage maxima at ca. 90 000, 73 000, 64 000, 54 000, 45 000 – 32 000, and 10 000 years BP. Incursions of subpolar planktonic foraminifera into the area during parts of isotopic stage 2 (between about 13 000 and 25 000 years BP but probably excluding the 15 000–18 000 years BP glacial maximum interval) and during the isotopic stage 4/5a transition (around 75 000 years BP) suggest that the eastern Labrador Sea was free of sea ice, at least in summer during periods of rapid continental ice sheet growth which lead to the isotopic stage 4 and stage 2 glacial maxima. A larger than normal stage 1/stage 2 difference in the isotopic composition of benthonic foraminifera (1.8‰) implies that this open water and attendant surface cooling was a potential source for colder than modern deep water. In contrast the Norwegian Sea was a reservoir of warmer than modern deep water during the last glacial.

New Faunal and Isotopic Evidence on the Late Weichselian—Holocene Oceanographic Changes in the Norwegian Sea

1984 ◽  
Vol 21 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Hans Petter Sejrup ◽  
Eystein Jansen ◽  
Helmut Erlenkeuser ◽  
Hans Holtedahl
Keyword(s):  
Deep Water ◽  
Circulation Pattern ◽  
Oceanic Circulation ◽  
Surface Cooling ◽  
Norwegian Sea ◽  
Neogloboquadrina Pachyderma ◽  
The North ◽  
Lower Oxygen ◽  
Late Weichselian ◽  
Stage 1

Downcore studies of planktonic and benthonic foraminifera and δ18O and δ13C in the planktonic foraminifer Neogloboquadrina pachyderma (sin.) in two piston cores from the southern part of the Norwegian Sea suggest large changes in the oceanic circulation pattern at the end of oxygenisotope stage 2 and in the early part of stage 1. Prior to oxygen-isotope Termination IA (16,000–13,000 yr B.P.), an isolated watermass with lower oxygen content and temperature warmer than today existed below a low salinity ice-covered surface layer in the Norwegian Sea. Close to Termination IA, well-oxygenated deep water, probably with positive temperatures, was introduced. This deep water, which must have had physical and/or chemical parameters different from those of present deep water in the Norwegian Sea, could have been introduced from the North Atlantic or been formed within the basin by another mechanism than that which forms the present deep water of the Norwegian Sea. A seasonal ice cover in the southern part of the Norwegian Sea is proposed for the period between Termination IA and the beginning of IB (close to 10,000 yr B.P.). The present situation, with strong influx of warm Atlantic surface-water and deep-water formation by surface cooling, was established at Termination IB.

Late Quaternary (Stage 2 and 3) Meltwater and Heinrich Events, Northwest Labrador Sea

1994 ◽  
Vol 41 (1) ◽  
pp. 26-34 ◽  
Author(s):  
John T. Andrews ◽  
Helmut Erlenkeuser ◽  
Katherine Tedesco ◽  
Ali E. Aksu ◽  
A.J.Timothy Jull
Keyword(s):  
North Atlantic ◽  
Late Quaternary ◽  
Planktonic Foraminifera ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Labrador Sea ◽  
Near Surface ◽  
Heinrich Events ◽  
Eastern Margin ◽  
Detrital Carbonate

AbstractTwo major meltwater events are documented in cores from the NW Labrador Sea. One occurred ca. 20,000 14C yr B.P. in association with deposition of a major detrital carbonate unit. Both prior to and after this event, δ18O values of near-surface planktonic foraminifera were 4.5%, indicating fully enriched glacial values. A younger event (ca. 14,000 14 C yr B.P.) is characterized by a dramatic change in δ18O from 4.5 to 2.0% and coincided with the retreat of ice from the outer SE Baffin Shelf, possibly into Hudson Strait. These meltwater events coincide with Heinrich (H) layers 1 and 2 from North Atlantic sediments. The 14,000 14C yr B.P. meltwater event indicates that the eastern margin of the Laurentide Ice Sheet also underwent rapid retreat at approximately the same time as other ice sheet margins around the NE North Atlantic. A third major detrital carbonate event at the base of HU87-033-009, possibly correlative with Heinrich layer 3, occurred ca. 33,960 ± 675 14 C yr B.P.; however, this is older than the accepted date for H-3 of 27,000 14C yr B.P. and may be H-4.

Late Quaternary circulation changes and sedimentation in Disko Bugt and adjacent fjords, central West Greenland

2001 ◽  
pp. 41-47 ◽  
Author(s):  
Antoon Kuijpers ◽  
Jerry M. Lloyd ◽  
Jørn B. Jensen ◽  
Rudolf Endler ◽  
Matthias Moros ◽  
...  
Keyword(s):  
Deep Water ◽  
Large Scale ◽  
Late Quaternary ◽  
Deep Ocean ◽  
Labrador Sea ◽  
Deep Water Formation ◽  
West Greenland ◽  
Water Formation ◽  
Inland Ice ◽  
Circulation Changes

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kuijpers, A., Lloyd, J. M., Jensen, J. B., Endler, R., Moros, M., Park, L. A., Schulz, B., Gutfelt Jensen, K., & Laier, T. (2001). Late Quaternary circulation changes and sedimentation in Disko Bugt and adjacent fjords, central West Greenland. Geology of Greenland Survey Bulletin, 189, 41-47. https://doi.org/10.34194/ggub.v189.5153 _______________ Several important outlets for meltwater and iceberg discharge occur along the margin of the Greenland Inland Ice. One of these is Disko Bugt in central West Greenland (Fig. 1). Large-scale exchange processes between the deep ocean and atmosphere are highly sensitive with regard to meltwater fluxes and global climate change. The Greenland Sea and Labrador Sea (see Fig. 1) with adjacent waters are the only regions in the Northern Hemisphere where deep-water formation occurs. New evidence shows that this process appears to be highly variable (e.g. Sy et al. 1997). Thus, meltwater production and iceberg calving from the Inland Ice margin of West Greenland may play a crucial role in controlling deep-water formation, notably in the Labrador Sea.

Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

1995 ◽  
Vol 53 ◽  
pp. 970-971
Author(s):  
L. Vacca-Galloway ◽  
Y.Q. Zhang ◽  
P. Bose ◽  
S.H. Zhang
Keyword(s):  
Spinal Cord ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Wild Type Mouse ◽  
Reflex Response ◽  
Mouse Strains ◽  
Behavioral Tests ◽  
Wobbler Mouse ◽  
Stage 4 ◽  
Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

Late Quaternary palaeo-oceanography of the Denmark Strait overflow pathway, South-East Greenland margin

1998 ◽  
Vol 180 ◽  
pp. 163-167
Author(s):  
Antoon Kuijpers ◽  
Jørn Bo Jensen ◽  
Simon R . Troelstra ◽  
And shipboard scientific party of RV Professor Logachev and RV Dana
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Deep Convection ◽  
Conveyor Belt ◽  
Water Masses ◽  
Labrador Sea ◽  
Greenland Sea ◽  
The North ◽  
Denmark Strait ◽  
The North Atlantic

Direct interaction between the atmosphere and the deep ocean basins takes place today only in the Southern Ocean near the Antarctic continent and in the northern extremity of the North Atlantic Ocean, notably in the Norwegian–Greenland Sea and Labrador Sea. Cooling and evaporation cause surface waters in the latter region to become dense and sink. At depth, further mixing occurs with Arctic water masses from adjacent polar shelves. Export of these water masses from the Norwegian–Greenland Sea (Norwegian Sea Overflow Water) to the North Atlantic basin occurs via two major gateways, the Denmark Strait system and the Faeroe– Shetland Channel and Faeroe Bank Channel system (e.g. Dickson et al. 1990; Fig.1). Deep convection in the Labrador Sea produces intermediate waters (Labrador Sea Water), which spreads across the North Atlantic. Deep waters thus formed in the North Atlantic (North Atlantic Deep Water) constitute an essential component of a global ‘conveyor’ belt extending from the North Atlantic via the Southern and Indian Oceans to the Pacific. Water masses return as a (warm) surface water flow. In the North Atlantic this is the Gulf Stream and the relatively warm and saline North Atlantic Current. Numerous palaeo-oceanographic studies have indicated that climatic changes in the North Atlantic region are closely related to changes in surface circulation and in the production of North Atlantic Deep Water. Abrupt shut-down of the ocean-overturning and subsequently of the conveyor belt is believed to represent a potential explanation for rapid climate deterioration at high latitudes, such as those that caused the Quaternary ice ages. Here it should be noted, that significant changes in deep convection in Greenland waters have also recently occurred. While in the Greenland Sea deep water formation over the last decade has drastically decreased, a strong increase of deep convection has simultaneously been observed in the Labrador Sea (Sy et al. 1997).

Novel staging classification of primary mitral regurgitation based on the presence of cardiac damage

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A.L Van Wijngaarden ◽  
Y.L Hiemstra ◽  
P Van Der Bijl ◽  
V Delgado ◽  
N Ajmone Marsan ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Kidney Function ◽  
Left Ventricular ◽  
Prognostic Impact ◽  
Cardiac Damage ◽  
Stage 4 ◽  
All Cause Mortality ◽  
Primary Mitral Regurgitation ◽  
Stage 1 ◽  
Staging Classification

Abstract Background The indication for surgery in patients with severe primary mitral regurgitation (MR) is currently based on the presence of symptoms, left ventricular (LV) dilatation and dysfunction, atrial fibrillation and pulmonary hypertension. The aim of this study was to evaluate the prognostic impact of a new staging classification based on cardiac damage including the known risk factors but also including global longitudinal strain (GLS), severe left atrial (LA) dilatation and right ventricular (RV) dysfunction. Methods In total 614 patients who underwent surgery for severe primary MR with available baseline transthoracic echocardiograms were included. Patients were classified according to the extent of cardiac damage (Figure): Stage 0-no cardiac damage, Stage 1-LV damage, Stage 2-LA damage, Stage 3-pulmonary vasculature or tricuspid valve damage and Stage 4-RV damage. Patients were followed for all-cause mortality. Results Based on the proposed classification, 172 (28%) patients were classified as Stage 0, 102 (17%) as Stage 1, 134 (21%) as Stage 2, 135 (22%) as Stage 3 and 71 (11%) as Stage 4. The more advanced the stage, the older the patients were with worse kidney function, more symptoms and higher EuroScore. Kaplan-Meier curve analysis revealed that patients with more advanced stages of cardiac damage had a significantly worse survival (log-rank chi-square 35.2; p<0.001) (Figure). On multivariable analysis, age, male, chronic obstructive pulmonary disease, kidney function, and stage of cardiac damage were independently associated with all-cause mortality. For each stage increase, a 22% higher risk for all-cause mortality was observed (95% CI: 1.064–1.395; p=0.004). Conclusion In patients with severe primary MR, a novel staging classification based on the extent of cardiac damage, may help refining risk stratification, particularly including also GLS, LA dilatation and RV dysfunction in the assessment. Funding Acknowledgement Type of funding source: None

A Description of Middle School Male Singers’ Voice Change and Voice Part Assignment

2021 ◽  
pp. 875512332110182
Author(s):  
Ryan Austin Fisher ◽  
Nancy L. Summitt ◽  
Ellen B. Koziel
Keyword(s):  
Middle School ◽  
Sixth Grade ◽  
Eighth Grade ◽  
Voice Change ◽  
Stage 4 ◽  
Public Middle School ◽  
Middle School Choir ◽  
Choral Programs ◽  
Stage 1 ◽  
The Voice

The purpose of this study was to describe the voice change and voice part assignment of male middle school choir members. Volunteers ( N = 92) were recruited from three public middle school choral programs (Grades 6-8). Participants were audio-recorded performing simple vocal tasks in order to assess vocal range and asked to share the music they were currently singing in class. Results revealed 23.91% of participants’ voices could be categorized as unchanged, 14.13% as Stage 1, 3.26% as Stage 2, 10.87% as Stage 3, 26.09% as Stage 4, and 21.74% as Stage 5. The majority of sixth-grade participants were classified as unchanged or in Stage 1 of the voice change and the majority of eighth-grade participants were classified in Stages 4 to 5 of the voice change. Of the participants labeled “tenors” in their choir, over 60% were classified as either unchanged voices or in Stage 1 of the voice change.

scholarly journals Temporal changes of quantitative CT findings from 102 patients with COVID-19 in Wuhan, China: A longitudinal study

2021 ◽  
Vol 29 ◽  
pp. 297-309
Author(s):  
Xiaohui Chen ◽  
Wenbo Sun ◽  
Dan Xu ◽  
Jiaojiao Ma ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Lung Diseases ◽  
Early Stage ◽  
Temporal Changes ◽  
Time Interval ◽  
Lesion Area ◽  
Quantitative Ct ◽  
Diagnosis And Prognosis ◽  
Ct Findings ◽  
Stage 4 ◽  
Stage 1

BACKGROUND: Computed tomography (CT) imaging combined with artificial intelligence is important in the diagnosis and prognosis of lung diseases. OBJECTIVE: This study aimed to investigate temporal changes of quantitative CT findings in patients with COVID-19 in three clinic types, including moderate, severe, and non-survivors, and to predict severe cases in the early stage from the results. METHODS: One hundred and two patients with confirmed COVID-19 were included in this study. Based on the time interval between onset of symptoms and the CT scan, four stages were defined in this study: Stage-1 (0 ∼7 days); Stage-2 (8 ∼ 14 days); Stage-3 (15 ∼ 21days); Stage-4 (> 21 days). Eight parameters, the infection volume and percentage of the whole lung in four different Hounsfield (HU) ranges, ((-, -750), [-750, -300), [-300, 50) and [50, +)), were calculated and compared between different groups. RESULTS: The infection volume and percentage of four HU ranges peaked in Stage-2. The highest proportion of HU [-750, 50) was found in the infected regions in non-survivors among three groups. CONCLUSIONS: The findings indicate rapid deterioration in the first week since the onset of symptoms in non-survivors. Higher proportion of HU [-750, 50) in the lesion area might be a potential bio-marker for poor prognosis in patients with COVID-19.

scholarly journals P0828CKD STAGE DISTRIBUTION IN AN ITALIAN PROVINCE; SEVEN YEARS OF FOLLOW UP

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Alessandro Roggeri ◽  
Daniela Paola Roggeri ◽  
Carlotta Rossi ◽  
Marco Gambera ◽  
Rossana Piccinelli ◽  
...  
Keyword(s):  
Hospital Discharge ◽  
Administrative Database ◽  
Ca Channel ◽  
Dialysis Treatment ◽  
First Choice ◽  
Stage 4 ◽  
Ckd Stage ◽  
Significant Difference ◽  
Stage 1

Abstract Background and Aims Chronic kidney disease (CKD) is a chronic illness with important implications for the health of the population and for the commitment of resources by public health services. CKD staging makes it possible to assess the severity of the disease and its distribution in the population. The distribution of the stages of CKD diagnosed through hospitalization were analyzed using administrative database of the Local Health Authority of a province with a population of about 1 million inhabitants in northern Italy. Method Patients with hospital discharge with a diagnosis of CKD (ICD9CM 5851, 5852, 5853, 5854) in 2011- 2012 years, without dialysis treatment, neither transplantation procedure nor acute renal failure were selected. Demographic characteristics, comorbidities, dialysis treatment, drugs prescription and nephrological follow-up were investigated. This cohort of patients was examined over a 7-year period (2011-2017). Stage five was not considered to avoid possible misunderstanding with five D stage. Results 1808 patients diagnosed with CKD were extracted from the 2011-2017 administrative database; of these, 1267 had a diagnosis with the CKD stage specification. The distribution of 1267 patients in the CKD stages at the first hospital discharge was as follows: 7.4% stage 1, 30.9% stage 2, 42.3% stage 3, 19.3% stage 4. The 832 patients described in the study were still alive as of Jan. 1, 2013 while 435 (34.3%) died by Dec. 31, 2012. Until Dec. 31, 2017, 503 of the 832 patients died representing the 52.8% of stage 1 patients, 62% of stage 2 patients, 58.2% of stage 3 patients, 66.4% of stage 4 patients. Males were the most prevalent gender (58.5%), without any significant difference into CKD stages. Our patients have a fairly high age as can be seen from the table 1. The presence of co-morbidities was assessed either directly for the main risk factors or by the modified Charlson index (MCI) for CKD patients. The average value of the MCI is 3.8 ± 3.1 for all patients and 3.4 ±3.0 for stage 1, 4.1 ± 3.3 for stage 2, 3.7 ± 3.1 for stage 3, 3.7 ± 2.9 for stage 4, with maximum values of 12.0, 17.0, 16.0 and 14.0 respectively. About 40% of patients had diabetes mellitus, with the highest prevalence in stage 4 (49.3%) and the lowest in stage 1 (25%). Cardiovascular disease was distributed almost equally among all patients with a value between 82% in stage 1 and 86.3% in stage 4. Cancer were present in 26.3% of patients with similar values in all stages. Just about 9% of patients underwent dialysis treatment for achieving ESRD, with a percentage of 5.6% among patients in stage 1 and 17.1% among those in stage 4. Hemodialysis represented first choice treatment (86%) compared with peritoneal one (14%). Time from the diagnosis of CKD to the first dialysis was variable with an average of 3.4 ±1.7 years; the longest interval for patients in stage 1 (5.1±1.8) and the shortest (3.0 ±1.6) for patients in stage 4. The number of nephrological visits at renal units was analyzed for an assessment of the extent of follow-up and prevention upon reaching the ESRD (table2). More than 90% of patients had prescribed drugs antagonists of the renin angiotensin system, in all stages of CKD; other antihypertensive drugs (Ca channel blockers and peripheral vasodilators) had a similar prescription level. Anemia control drugs (ESA and iron) had an incremental prescription with stages of the disease from 51.4% in stage 1 to 74% in stage 4, similarly to Ca-P metabolism control drugs ranging from 44.4% in stage 1 to 67.8% in stage 4. Conclusion Correct staging of CKD is very important to assess the prognosis of patients, but the major determinants of outcome are comorbidities and age of the patients. The cohort examined has a high mortality rate, far higher than reported in the literature for CKD. It should be noted that the sample was identified by hospitalization for cardiovascular diseases more than 50% complicated by diabetes and hypertension, so death represents the main outcome and not ESRD.

Sign in / Sign up

Export Citation Format

Share Document