scholarly journals Arctic and Antarctic lakes as optical indicators of global change

1998 ◽  
Vol 27 ◽  
pp. 691-696 ◽  
Author(s):  
Warwick E. Evincent ◽  
Isabelle Laurion ◽  
Reinhard Pienitz
Keyword(s):  
High Latitude ◽  
Stratospheric Ozone ◽  
Light Availability ◽  
Climate Forcing ◽  
Future Research ◽  
Lake Ice ◽  
Ice Dynamics ◽  
Unit Energy

Lakes are a major feature of Arctic and Antarctic landscapes and are likely to be sensitive indicators ofclimate change. New bio-optical technologies for in situ measurements (e.g. UV-profiling) and remote sensing (e.g. light detection and ranging) now offer a suite of options for long-term monitoring at these sites. Certain properties of high-latitude lakes are highly responsive to changes in climate forcing and could be targeted within a monitoring strategy based on optical properties; these include lake levels, lake-ice dynamics, phytoplankton biomass and chromophoric dissolved organic matter (CDOM). High-latitude lakes are optically sensitive to changes in CDOM export from their surrounding catchments that could result from climate effects on hydrology and vegetation. Using a new model based on biologically weighted transparency, we show that a 20% change in GDOM concentration (as measured by dissolved organic carbon) can have a much greater effect on UV inhibition of phytoplankton than a similar percentage change in stratospheric ozone. Much of this effect is due to UV-A, because the reduced photodamaging effect per unit energy (i.e. low biological weighting) in this waveband is offset by its higher incident flux at the lake surface relative to UV-B and its deeper penetration into the water column. These transparency calculations also show that small changes in CDOM in polar lakes will have a large effect on underwater light availability for photosynthesis. The spectral absorption and fluorescence properties of CDOM lend themselves to a variety of optical monitoring approaches. Future research on the paleo-optics of GDOM will allow the interpretation of current optical trends in high-latitude lakes relative to the scales of natural variability in the past.

scholarly journals High-latitude obliquity forcing drives the agulhas leakage

2011 ◽  
Vol 7 (3) ◽  
pp. 2193-2215 ◽  
Author(s):  
T. Caley ◽  
J.-H. Kim ◽  
B. Malaizé ◽  
J. Giraudeau ◽  
T. Laepple ◽  
...  
Keyword(s):  
High Latitude ◽  
Decadal Variability ◽  
Global Climate ◽  
Decisive Role ◽  
Meridional Overturning Circulation ◽  
Climate Forcing ◽  
Meridional Overturning ◽  
The Indian Ocean ◽  
Forcing Mechanisms

Abstract. The Agulhas Current (AC) transport of heat and salt from the Indian Ocean into the South Atlantic around South Africa (Agulhas leakage), has a profound role in the decadal variability of the Atlantic meridional overturning circulation (AMOC), which influences global climate. On glacial-interglacial timescales, paleostudies postulate that Agulhas leakage plays a decisive role for AMOC resumption during terminations (glacial-interglacial transitions). However, efforts to elucidate forcing mechanisms connecting Agulhas leakage with glacial-interglacial AMOC variability have been hampered due to a lack of climate records extracted from the area where the AC originates. Here we present 800-kyr sea surface temperature (SST) and salinity (SSS) records from the "precursor" region of the AC. These records contain strong obliquity-driven 41-kyr cycles, nearly in phase with changes in annual mean insolation and air temperature at high southern latitudes. In contrast, precession-driven cycles were negligible in our SST records, which is surprising given the low-latitude location of the Agulhas leakage. Together, this suggests that long-term Agulhas leakage dynamics are associated with a high latitude rather than a tropical climate forcing mechanism, probably by varying the position of the Southern Hemisphere subtropical convergence (STC) and its associated westerlies. We argue that during terminations stronger Agulhas leakage was triggered by increased obliquity exerting a positive feedback on the global climate system through modulating long-term AMOC variations.

scholarly journals Coherence of long-term stratospheric ozone vertical distribution time series used for the study of ozone recovery at a northern mid-latitude station

2011 ◽  
Vol 11 (10) ◽  
pp. 4957-4975 ◽  
Author(s):  
P. J. Nair ◽  
S. Godin-Beekmann ◽  
A. Pazmiño ◽  
A. Hauchecorne ◽  
G. Ancellet ◽  
...  
Keyword(s):  
Time Series ◽  
Stratospheric Ozone ◽  
Stratospheric Aerosol ◽  
Data Sets ◽  
Zero Bias ◽  
Lidar Measurements ◽  
Relative Differences ◽  
Difference Time

Abstract. The coherence of stratospheric ozone time series retrieved from various observational records is investigated at Haute-Provence Observatory (OHP–43.93° N, 5.71° E). The analysis is accomplished through the intercomparison of collocated ozone measurements of Light Detection and Ranging (lidar) with Solar Backscatter UltraViolet(/2) (SBUV(/2)), Stratospheric Aerosol and Gas Experiment II (SAGE~II), Halogen Occultation Experiment (HALOE), Microwave Limb Sounder (MLS) on Upper Atmosphere Research Satellite (UARS) and Aura and Global Ozone Monitoring by Occultation of Stars (GOMOS) satellite observations as well as with in situ ozonesondes and ground-based Umkehr measurements performed at OHP. A detailed statistical study of the relative differences of ozone observations over the whole stratosphere is performed to detect any specific drift in the data. On average, all instruments show their best agreement with lidar at 20–40 km, where deviations are within ±5 %. Discrepancies are somewhat higher below 20 and above 40 km. The agreement with SAGE II data is remarkable since average differences are within ±1 % at 17–41 km. In contrast, Umkehr data underestimate systematically the lidar measurements in the whole stratosphere with a near zero bias at 16–8 hPa (~30 km). Drifts are estimated using simple linear regression for the data sets analysed in this study, from the monthly averaged difference time series. The derived values are less than ±0.5 % yr−1 in the 20–40 km altitude range and most drifts are not significant at the 2σ level. We also discuss the possibilities of extending the SAGE II and HALOE data with the GOMOS and Aura MLS data in consideration with relative offsets and drifts since the combination of such data sets are likely to be used for the study of stratospheric ozone recovery in the future.

scholarly journals Coherence of long-term stratospheric ozone vertical distribution time series used for the study of ozone recovery at a northern mid-latitude station

2010 ◽  
Vol 10 (11) ◽  
pp. 28519-28564
Author(s):  
P. J. Nair ◽  
S. Godin-Beekmann ◽  
A. Pazmiño ◽  
A. Hauchecorne ◽  
G. Ancellet ◽  
...  
Keyword(s):  
Time Series ◽  
Stratospheric Ozone ◽  
Stratospheric Aerosol ◽  
Data Sets ◽  
Zero Bias ◽  
Lidar Measurements ◽  
Relative Differences ◽  
Difference Time

Abstract. The coherence of stratospheric ozone time series retrieved from various observational records is investigated at Haute–Provence Observatory (OHP–43.93° N, 5.71° E). The analysis is accomplished through the intercomparison of collocated ozone measurements of Light Detection and Ranging (lidar) with Solar Backscatter UltraViolet(/2) (SBUV(/2)), Stratospheric Aerosol and Gas Experiment II (SAGE II), Halogen Occultation Experiment (HALOE), Microwave Limb Sounder (MLS) on Upper Atmosphere Research Satellite (UARS) and Aura and Global Ozone Monitoring by Occultation of Stars (GOMOS) satellite observations as well as with in-situ ozonesondes and ground-based Umkehr measurements performed at OHP. A detailed statistical study of the relative differences of ozone observations is performed to detect any specific drifts in the data. On average, all instruments show their best agreement with lidar at 20–40 km, where deviations are within ±5%. Discrepancies are somewhat higher below 20 and above 40 km. The agreement with SAGE II data is remarkable since average differences are within ±1% at 17–41 km. In contrast, Umkehr data underestimate systematically the lidar measurements in the whole stratosphere albeit a near zero bias is observed at 16–8 hPa (~30 km). Drifts are estimated using simple linear regression for the long-term (more than 10 years long) data sets analysed in this study, from the monthly averaged difference time series. The derived values are less than ±0.5% yr−1 in the 20–40 km altitude range and most drifts are not significant at the 2σ level.

Physical and Psychological Benefits of Written Emotional Expression

2015 ◽  
Vol 20 (4) ◽  
pp. 242-251 ◽  
Author(s):  
Éva Kállay
Keyword(s):  
Mental Health ◽  
Expressive Writing ◽  
Mental Health Problems ◽  
Cost Effective ◽  
Health Problems ◽  
Future Research ◽  
Psychological Benefits ◽  
Cost Effective Treatment ◽  
Meta Analyses

Abstract. The last several decades have witnessed a substantial increase in the number of individuals suffering from both diagnosable and subsyndromal mental health problems. Consequently, the development of cost-effective treatment methods, accessible to large populations suffering from different forms of mental health problems, became imperative. A very promising intervention is the method of expressive writing (EW), which may be used in both clinically diagnosable cases and subthreshold symptomatology. This method, in which people express their feelings and thoughts related to stressful situations in writing, has been found to improve participants’ long-term psychological, physiological, behavioral, and social functioning. Based on a thorough analysis and synthesis of the published literature (also including most recent meta-analyses), the present paper presents the expressive writing method, its short- and long-term, intra-and interpersonal effects, different situations and conditions in which it has been proven to be effective, the most important mechanisms implied in the process of recovery, advantages, disadvantages, and possible pitfalls of the method, as well as variants of the original technique and future research directions.

Using the Change4Life Disney Branded 10-minute Shake Ups During the COVID-19 ‘Lockdown’

2020 ◽  
Author(s):  
Emily Budzynski-Seymour ◽  
James Steele ◽  
Michelle Jones
Keyword(s):  
Perceived Exertion ◽  
Affective Responses ◽  
Online Resources ◽  
Future Research ◽  
Affective States ◽  
Perceived Effort ◽  
Qualitative Feedback ◽  
Bidirectional Relationship ◽  
The Uk

Physical activity (PA) is considered essential to overall health yet it is consistently reported that children are failing to meet the recommended levels. Due to the bidirectional relationship between affective states and PA, affective responses are a potential predictor to long term engagement. Since late March 2020 the UK government enforced ‘lockdown’ measures to help control the spread of Coronavirus (COVID-19); however, this has impacted children’s PA. Using online resources at home to support PA is now common. The primary aim of this research was to investigate the use of the Change4Life 10-minute Shake Ups to support PA by examining the effects of Disney branding upon children’s (n=32) post activity affective responses and perceived exertion. The secondary was to investigate the effect of the lockdown on PA habits. Children had similar positive affective responses and perceived effort to activities; however, branding was considered to be a key contributing factor based upon qualitative feedback from parents. Children’s PA levels dropped slightly since ‘lockdown’ was imposed; though online resources have been utilised to support PA. The use of immersive elements such as characters and narrative in PA sessions, as well as utilising online resources during ‘lockdown’ appear potentially promising for future research.

Chinese Medicine Protein and Peptide in Gene and Cell Therapy

2019 ◽  
Vol 20 (3) ◽  
pp. 251-264 ◽  
Author(s):  
Yinlu Feng ◽  
Zifei Yin ◽  
Daniel Zhang ◽  
Arun Srivastava ◽  
Chen Ling
Keyword(s):  
Chinese Medicine ◽  
Cell Therapy ◽  
Future Research ◽  
The Past ◽  
Promising Strategy ◽  
Wide Range ◽  
New Directions ◽  
Gene And Cell Therapy ◽  
Proteins And Peptides

The success of gene and cell therapy in clinic during the past two decades as well as our expanding ability to manipulate these biomaterials are leading to new therapeutic options for a wide range of inherited and acquired diseases. Combining conventional therapies with this emerging field is a promising strategy to treat those previously-thought untreatable diseases. Traditional Chinese medicine (TCM) has evolved for thousands of years in China and still plays an important role in human health. As part of the active ingredients of TCM, proteins and peptides have attracted long-term enthusiasm of researchers. More recently, they have been utilized in gene and cell therapy, resulting in promising novel strategies to treat both cancer and non-cancer diseases. This manuscript presents a critical review on this field, accompanied with perspectives on the challenges and new directions for future research in this emerging frontier.

Ketamine Treatment in Depression: A Systematic Review of Clinical Characteristics Predicting Symptom Improvement

2020 ◽  
Vol 20 (15) ◽  
pp. 1398-1414 ◽  
Author(s):  
Darby J.E. Lowe ◽  
Daniel J. Müller ◽  
Tony P. George
Keyword(s):  
Clinical Features ◽  
Clinical Characteristics ◽  
Bipolar Depression ◽  
Antidepressant Effect ◽  
Future Research ◽  
Symptom Improvement ◽  
Randomized Controlled ◽  
Treatment Of Depression ◽  
Future Direction

Ketamine has been shown to be efficacious for the treatment of depression, specifically among individuals who do not respond to first-line treatments. There is still, however, a lack of clarity surrounding the clinical features and response periods across samples that respond to ketamine. This paper systematically reviews published randomized controlled trials that investigate ketamine as an antidepressant intervention in both unipolar and bipolar depression to determine the specific clinical features of the samples across different efficacy periods. Moreover, similarities and differences in clinical characteristics associated with acute versus longer-term drug response are discussed. Similarities across all samples suggest that the population that responds to ketamine’s antidepressant effect has experienced chronic, long-term depression, approaching ketamine treatment as a “last resort”. Moreover, differences between these groups suggest future research to investigate the potential of stronger efficacy towards depression in the context of bipolar disorder compared to major depression, and in participants who undergo antidepressant washout before ketamine administration. From these findings, suggestions for the future direction of ketamine research for depression are formed.

scholarly journals Modelling of speleothems failure in the Hotton cave (Belgium). Is the failure earthquake induced?

2001 ◽  
Vol 80 (3-4) ◽  
pp. 315-321 ◽  
Author(s):  
J.F. Cadorin ◽  
D. Jongmans ◽  
A. Plumier ◽  
T. Camelbeeck ◽  
S. Delaby ◽  
...  
Keyword(s):  
Natural Frequencies ◽  
Quantitative Information ◽  
Rigid Bodies ◽  
Tensile Failure ◽  
Future Research ◽  
Geometrical Parameters ◽  
Laboratory Measurements ◽  
Ground Acceleration ◽  
Strong Ground

AbstractTo provide quantitative information on the ground acceleration necessary to break speleothems, laboratory measurements on samples of stalagmite have been performed to study their failure in bending. Due to their high natural frequencies, speleothems can be considered as rigid bodies to seismic strong ground motion. Using this simple hypothesis and the determined mechanical properties (a minimum value of 0.4 MPa for the tensile failure stress has been considered), modelling indicates that horizontal acceleration ranging from 0.3 m/s2 to 100 m/s2 (0.03 to 10g) are necessary to break 35 broken speleothems of the Hotton cave for which the geometrical parameters have been determined. Thus, at the present time, a strong discrepancy exists between the peak accelerations observed during earthquakes and most of the calculated values necessary to break speleothems. One of the future research efforts will be to understand the reasons of the defined behaviour. It appears fundamental to perform measurements on in situ speleothems.

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