scholarly journals Experimental evidence for foraminiferal calcification under anoxia

2014 ◽  
Vol 11 (14) ◽  
pp. 4029-4038 ◽  
Author(s):  
M. P. Nardelli ◽  
C. Barras ◽  
E. Metzger ◽  
A. Mouret ◽  
H. L. Filipsson ◽  
...  
Keyword(s):  
Environmental Variability ◽  
Sediment Cores ◽  
Adult Mortality ◽  
Short Term ◽  
Essential Information ◽  
Ample Evidence ◽  
Anoxic Conditions ◽  
Inhibition Of Growth ◽  
Foraminiferal Species ◽  
First Time

Abstract. Benthic foraminiferal tests are widely used for paleoceanographic reconstructions from a range of different environments with varying dissolved oxygen concentrations in the bottom water. There is ample evidence that foraminifera can live in anoxic sediments. For some species, this is explained by a switch to facultative anaerobic metabolism (i.e. denitrification). Here we show for the first time that adult specimens of three benthic foraminiferal species are not only able to survive, but are also able to calcify under anoxic conditions, at various depths in the sediment, and with or without nitrates. In fact, several specimens of Ammonia tepida (1–4%), Bulimina marginata (8–24%) and Cassidulina laevigata (16–23%) were able to calcify at different redox fronts of sediment cores, under laboratory conditions. This demonstrates ongoing metabolic processes, even in micro-environments where denitrification is not possible. Earlier observations suggest that the disappearance of foraminiferal communities after prolonged anoxia is not due to instantaneous or strongly increased adult mortality. Here we show that it cannot be explained by an inhibition of growth through chamber addition either. Our observations of ongoing calcification under anoxic conditions mean that geochemical proxy data obtained from benthic foraminifera in settings experiencing intermittent anoxia have to be reconsidered. The analysis of whole single specimens or of their successive chambers may provide essential information about short-term environmental variability and/or the causes of anoxia.

scholarly journals Experimental evidence for foraminiferal calcification under anoxia

2014 ◽  
Vol 11 (3) ◽  
pp. 4669-4694 ◽  
Author(s):  
M. P. Nardelli ◽  
C. Barras ◽  
E. Metzger ◽  
A. Mouret ◽  
H. L. Filipsson ◽  
...  
Keyword(s):  
Anaerobic Metabolism ◽  
Environmental Variability ◽  
Adult Mortality ◽  
Short Term ◽  
Essential Information ◽  
Ample Evidence ◽  
Anoxic Conditions ◽  
Inhibition Of Growth ◽  
Foraminiferal Species ◽  
First Time

Abstract. Benthic foraminiferal tests are widely used for paleoceanographic reconstructions. There is ample evidence that foraminifera can live in anoxic sediments. For some species, this is explained by a switch to facultative anaerobic metabolism (i.e. denitrification). Here we show for the first time that adult specimens of three benthic foraminiferal species are not only able to survive but are also able to calcify in anoxic conditions, at various depths in the sediment, with and without nitrates. This demonstrates ongoing metabolic processes, even in micro-environments where denitrification is not possible. Earlier observations suggest that the disappearance of foraminiferal communities after prolonged anoxia is not due to instantaneous or strongly increased adult mortality. Here we show that it cannot be explained by an inhibition of growth through chamber addition either. Our observations of ongoing calcification under anoxic conditions means that geochemical proxy data obtained from benthic foraminifera in settings experiencing intermittent anoxia have to be reconsidered. The analysis of whole single specimens or of their successive chambers may provide essential information about short-term environmental variability and/or the causes of anoxia.

Regulating short-term rentals: Joined cases C-724/18 and C-727/18 Cali Apartments

2021 ◽  
pp. 1023263X2110146
Author(s):  
Tania Pantazi
Keyword(s):  
Consumer Protection ◽  
European Court Of Justice ◽  
Short Term ◽  
European Regulation ◽  
Future Developments ◽  
Online Platforms ◽  
Court Of Justice ◽  
European Court ◽  
Tourist Accommodation ◽  
First Time

The increase in short-term rentals via online platforms has captured the attention of scholars and regulators. Short-term letting is now considered a considerable alternative to traditional tourist accommodation contracts, challenging matters such as conditions in the housing market and consumer protection. Online platforms, such as Airbnb, Booking.com , Expedia and Tripadvisor, now provide offers for short-term accommodation contracts along with traditional accommodation options (hotels, hostels, apartments). The recent decision of the European Court of Justice in Joined cases C-724/18 and C-727/18 addresses for the first time the issue of regulation of short-term rentals in Member States and evaluates a national authorization scheme in light of the Services Directive. The present paper provides a brief background of European regulation affecting short-term rentals and discusses the judgment and its implications for future developments.

scholarly journals A SLR Pre-Processing Algorithm Based on Satellite Signature Effect

2021 ◽  
Vol 11 (19) ◽  
pp. 8880
Author(s):  
Bowen Guan ◽  
Cunbo Fan ◽  
Ning An ◽  
Ricardo Cesar Podesta ◽  
Dra Ana Pacheco ◽  
...  
Keyword(s):  
Mean Value ◽  
Observation Data ◽  
Short Term ◽  
Error Sources ◽  
Effect Model ◽  
The Mean ◽  
The Stability ◽  
First Time ◽  
Satellite Signature Effect

As one of the major error sources, satellite signature effect should be reduced or even erased from the distribution of the post-fit residuals to improve the ranging precision. A simulation of satellite signature effect removal process for normal point algorithm is conducted based on a revised model of satellite response, which fully considers the structural and distribution characteristics of retroreflectors. In order to eliminate both long-term and short-term satellite signature effect, a clipping method for SLR data processing is proposed by defining the clipping location as 5.6 mm away from the mean value of the long-term fit residuals to select effective returns for normal points. The results indicate that, compared to normal points algorithm, the RMS per NP of LAGEOS-1 observation data processed by the clipping method is reduced from 62.90 ± 9.9 mm to 56.07 ± 4.69 mm, and the stability of RMS is improved 53%. This study improves the satellite signature effect model and simulates the fluctuation of normal points caused by satellite signature effect for the first time. The new method based on the simulation of satellite signature effect has stronger robustness and applicability, which can further minimize the influence of satellite signature effect on the SLR production and significantly improve the data property.

scholarly journals TAXONOMICAL CONSIDERATIONS, PHYLOGENY, PALEOGEOGRAPHY AND PALEOCLIMATOLOGY OF THE MIDDLE EOCENE (BARTONIAN) PLANKTIC FORAMINIFERA FROM JABAL HAFIT, AL AIN AREA, UNITED ARAB EMIRATES

2020 ◽  
Vol 4 (1) ◽  
pp. 10-20
Author(s):  
Haidar Salim Anan
Keyword(s):  
United Arab Emirates ◽  
Present Author ◽  
Middle Eocene ◽  
Planktic Foraminifera ◽  
Oman Mountains ◽  
Foraminiferal Species ◽  
Al Ain ◽  
Eastern Limb ◽  
First Time

The taxonomical consideration, probable phylogeny and stratigraphic significance of twenty-eight middle Eocene (Bartonian) planktic foraminiferal species from the eastern limb of Jabal Hafit, Al Ain area, United Arab Emirates (UAE), Northern Oman Mountains (NOM) are presented, and twenty one of them are illustrated. Identification of these twenty-eight species belonging to ten genera Globoturborotalia, Subbotina, Globigerinatheka, Inordinatosphaera, Orbulinoides, Hantkenina, Acarinina, Morozovelloides, Pseudohastigerina and Turborotalia has led to the recognition of three biostratigraphic zones, in ascending order: Morozovelloides lehneri PRZ (E11), Orbulinoides beckmanni TRZ (E12) and Morozovelloides crassata HOZ (E13). Eight out of the identified species are recorded, in this study, for the first time from Jabal Hafit: Globoturborotalia martini, Subbotina gortanii, S. jacksonensis, S. senni, Globigerinatheca barri, Acarinina praetopilensis, A. punctocarinata and Morozovelloides bandyi. The second or third record of three species from J. Hafit outside its original records are recently documented by the present author: Inordinatosphaera indica, Hantkenina australis and H. compressa. The paleontology, paleoclimatology and paleogeographic distribution of the identified taxa at Jabal Hafit and other Paleogene outcrops in the UAE and Tethys are presented and discussed. The identified fauna emphasis the wide geographic areas in the Tethys, from Atlantic to Indian-Pacific Oceans via Mediterranean.

Short-Term Training in Mindfulness Predicts Helping Behavior Toward Racial Ingroup and Outgroup Members

2021 ◽  
pp. 194855062110530
Author(s):  
Daniel R. Berry ◽  
Catherine S. J. Wall ◽  
Justin D. Tubbs ◽  
Fadel Zeidan ◽  
Kirk Warren Brown
Keyword(s):  
Controlled Trial ◽  
Helping Behavior ◽  
Mindfulness Training ◽  
Trait Mindfulness ◽  
Short Term ◽  
Randomized Controlled ◽  
Ecological Momentary ◽  
First Time ◽  
Momentary Assessment

A randomized controlled trial tested whether mindfulness training would increase lab-based and in vivo spontaneous helping behaviors toward racial outgroup members. First, across conditions, those scoring higher in baseline trait mindfulness showed higher levels of preintervention lab-based and ecological momentary assessment (EMA)-based helping behavior. Next, short-term (4-day) training in mindfulness, relative to a well-matched sham meditation training, increased interracial helping behavior in a lab-based simulation. Finally, among people scoring lower in a basic form of trait mindfulness at baseline—that is, with greater room for improvement—mindfulness training predicted higher postintervention in vivo helping behavior reported via EMA. However, neither training condition alone attenuated preferential helping toward racial ingroup members. These findings indicate, for the first time, that mindfulness and its training fosters helping behavior toward strangers and acquaintances regardless of their racial ingroup or outgroup status, but preferential helping of racial ingroup members remains.

Learning from a Frozen Ocean: The Changing Face of Antarctic Ocean Ecology

2016 ◽  
Author(s):  
Hugh W. Ducklow
Keyword(s):  
Research Collaboration ◽  
Scientific Work ◽  
Principal Investigator ◽  
Rate Of Change ◽  
Short Term ◽  
Temporal Perspective ◽  
Ocean Science ◽  
Long Term Ecological Research ◽  
History Of ◽  
First Time

The temporal perspective provided by the Long-Term Ecological Research (LTER) program places individual, limited, short-term observations and experiments in a valuable context. Proper interpretation of short-term results may be incomplete without a longer-term perspective. This often makes me skeptical of individual studies. The remote location and harsh environment of Antarctica place special demands and constraints on research, collaboration, and education. Meeting these challenges is one of the most exhilarating aspects of our LTER project. Keeping the proper balance between maintaining continuity of observations and keeping the research program new and innovative is another key challenge for research in the LTER program. But rather than constraining them, the ongoing nature of the LTER program facilitates and enhances creative observations and innovation. In 2001, I joined the LTER network as lead principal investigator for the Palmer LTER project (PAL), one of two pelagic marine sites in the LTER network. That was my first formal exposure to the LTER program, about midway through my scientific career. After majoring in the history of science in college, I received my PhD in environmental engineering from Harvard in 1977. I was originally trained as an environmental microbiologist and gradually evolved into a biological oceanographer and ocean biogeochemist. Prior to joining PAL, I worked in other large, multidisciplinary, and interdisciplinary ocean science programs. In addition to leading PAL, I study the roles of ocean microbes in the biogeochemical cycling of carbon and other elements in the ice-influenced ocean surrounding Antarctica. As a principal investigator, I participate in planning and guiding the LTER network. Network participation has significantly broadened my perspective on my own personal scientific work. This participation has been one of my more interesting and fulfilling experiences as a scientist. Over the past 20 years, research has shown that the western Antarctic Peninsula is one of the most rapidly warming regions on earth, and we are gradually beginning to understand how the ecosystem is responding to this unprecedented rate of change. Joining PAL changed my life. (Actually, going to Antarctica for the first time changed my life, but the LTER program gave me the opportunity to go there every year.)

scholarly journals Deep Recurrent Models with Fast-Forward Connections for Neural Machine Translation

2016 ◽  
Vol 4 ◽  
pp. 371-383 ◽  
Author(s):  
Jie Zhou ◽  
Ying Cao ◽  
Xuguang Wang ◽  
Peng Li ◽  
Wei Xu
Keyword(s):  
Machine Translation ◽  
Short Term Memory ◽  
Short Term ◽  
Neural Machine Translation ◽  
Attention Model ◽  
Linear Connections ◽  
New Type ◽  
Long Short Term Memory ◽  
Unknown Words ◽  
First Time

Neural machine translation (NMT) aims at solving machine translation (MT) problems using neural networks and has exhibited promising results in recent years. However, most of the existing NMT models are shallow and there is still a performance gap between a single NMT model and the best conventional MT system. In this work, we introduce a new type of linear connections, named fast-forward connections, based on deep Long Short-Term Memory (LSTM) networks, and an interleaved bi-directional architecture for stacking the LSTM layers. Fast-forward connections play an essential role in propagating the gradients and building a deep topology of depth 16. On the WMT’14 English-to-French task, we achieve BLEU=37.7 with a single attention model, which outperforms the corresponding single shallow model by 6.2 BLEU points. This is the first time that a single NMT model achieves state-of-the-art performance and outperforms the best conventional model by 0.7 BLEU points. We can still achieve BLEU=36.3 even without using an attention mechanism. After special handling of unknown words and model ensembling, we obtain the best score reported to date on this task with BLEU=40.4. Our models are also validated on the more difficult WMT’14 English-to-German task.

scholarly journals Tracing Long- and Short-term Migrants for Participation in Demographic and Epidemiological Studies: Evidence from Senegal

Field Methods ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 38-57
Author(s):  
Mufaro Kanyangarara ◽  
Laetitia Douillot ◽  
Gilles Pison ◽  
Cheikh Tidiane Ndiaye ◽  
Valerie Delaunay ◽  
...  
Keyword(s):  
Rural Areas ◽  
Statistical Power ◽  
Epidemiological Studies ◽  
Adult Mortality ◽  
Short Term ◽  
Middle Income ◽  
Middle Income Countries ◽  
Contact Information

Migration of participants in demographic and epidemiological studies results in missing data. One approach to reduce resulting losses in statistical power and potential biases is to follow up migrants at their new residence. We describe the follow-up of migrants who were eligible for participation in a trial of a new questionnaire to measure adult mortality in Niakhar, Senegal. We conducted a short inquiry in the migrant’s last known household to obtain contact information and then attempted to contact and interview 661 migrants who resided in Dakar, Mbour, and rural areas close to Niakhar. About two-thirds of migrants were successfully enrolled in the study. Having a contact phone number and knowing the name of the head of compound at destination increased the likelihood of successful enrollment. Following up migrants in demographic studies is feasible in low- and middle-income countries, including long-term migrants who have not been contacted for extended periods of time.

scholarly journals Measures of Self-Perception, Level of Physical Activity, and Body Mass Index of Participants of Sports Education Camps for Youths with Visual Impairments

2019 ◽  
Vol 113 (1) ◽  
pp. 43-56
Author(s):  
John McMahon ◽  
Robert S. Wall Emerson ◽  
Paul Ponchillia ◽  
Amy Curtis
Keyword(s):  
Physical Activity ◽  
Body Mass Index ◽  
Body Mass ◽  
Low Vision ◽  
Visual Impairments ◽  
Secondary Data ◽  
Intervention Model ◽  
Self Perception ◽  
Short Term ◽  
First Time

Introduction: This study explored the relationship between first-time or repeat participation at a sports education camp and demographic variables of gender, age, race or ethnicity, measures of self-perception, body mass index (BMI), and physical activity in participants’ communities. Methods: The study was a secondary data analysis of interview and BMI data for youths with visual impairments (i.e., those who are blind or have low vision) who attended a sports education camp in one of 12 states in the years 1989, 1996, and 2000–2010. Results: The short-term intervention model of a sports education camp had a positive effect on participants’ perceptions of themselves. This result was more pronounced for boys and for youths with some usable vision. Involvement in a sports education camp did not tend to translate to increased involvement in sports in a student’s community. The mean BMI of first-time participants was consistent across gender, race or ethnicity, and vision category, and the BMI of first-time participants tended to be higher according to the age of the participant. Discussion: The findings revealed that the short-term intervention model of a sports education camp is highly effective in increasing self-perception for youngsters with vision impairments. Implications for practitioners: For youths with visual impairments who might be experiencing reduced social interaction, decreased self-perception or increased BMI involvement in a sports education camp is a short-term intervention that can positively impact these effects.

scholarly journals Rhythmic neural activity is comodulated with short-term gait modifications during first-time use of a dummy prosthesis: a pilot study

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Vera G. M. Kooiman ◽  
Helco G. van Keeken ◽  
Natasha M. Maurits ◽  
Vivian Weerdesteyn ◽  
Teodoro Solis-Escalante
Keyword(s):  
Time Use ◽  
Ground Reaction Force ◽  
Gait Cycle ◽  
Reaction Force ◽  
Swing Phase ◽  
Experimental Session ◽  
Cycle Duration ◽  
Short Term ◽  
Gamma Rhythms ◽  
First Time

Abstract Background After transfemoral amputation, many hours of practice are needed to re-learn walking with a prosthesis. The long adaptation process that consolidates a novel gait pattern seems to depend on cerebellar function for reinforcement of specific gait modifications, but the precise, step-by-step gait modifications (e.g., foot placement) most likely rely on top-down commands from the brainstem and cerebral cortex. The aim of this study was to identify, in able-bodied individuals, the specific modulations of cortical rhythms that accompany short-term gait modifications during first-time use of a dummy prosthesis. Methods Fourteen naïve participants walked on a treadmill without (one block, 4 min) and with a dummy prosthesis (three blocks, 3 × 4 min), while ground reaction forces and 32-channel EEG were recorded. Gait cycle duration, stance phase duration, step width, maximal ground reaction force and, ground reaction force trace over time were measured to identify gait modifications. Independent component analysis of EEG data isolated brain-related activity from distinct anatomical sources. The source-level data were segmented into gait cycles and analyzed in the time–frequency domain to reveal relative enhancement or suppression of intrinsic cortical oscillations. Differences between walking conditions were evaluated with one-way ANOVA and post-hoc testing (α = 0.05). Results Immediate modifications occurred in the gait parameters when participants were introduced to the dummy prosthesis. Except for gait cycle duration, these modifications remained throughout the duration of the experimental session. Power modulations of the theta, mu, beta, and gamma rhythms, of sources presumably from the fronto-central and the parietal cortices, were found across the experimental session. Significant power modulations of the theta, beta, and gamma rhythms within the gait cycle were predominately found around the heel strike of both feet and the swing phase of the right (prosthetic) leg. Conclusions The modulations of cortical activity could be related to whole-body coordination, including the swing phase and placing of the prosthesis, and the bodyweight transfer between legs and arms. Reduced power modulation of the gamma rhythm within the experimental session may indicate initial motor memories being formed. Better understanding of the sensorimotor processes behind gait modifications may inform the development of neurofeedback strategies to assist gait rehabilitation.

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