scholarly journals Synergistic adaptations: freezing tolerance is associated with desiccation tolerance and activation of violaxanthin de-epoxidase in wintergreen ferns

2021 ◽  
Vol 72 (8) ◽  
pp. 2814-2817
Author(s):  
Helen I Holmlund
Keyword(s):  
Freezing Tolerance ◽  
Desiccation Tolerance ◽  
Xanthophyll Cycle ◽  
Night Time ◽  
Time Activity ◽  
Experimental Botany

This article comments on: Fernández-Marín B, Arzac MI, López-Pozo M, Laza JM, Roach T, Stegner M, Neuner G, García-Plazaola JI. 2021. Frozen in the dark: interplay of night-time activity of xanthophyll cycle, xylem attributes, and desiccation tolerance in fern resistance to winter. Journal of Experimental Botany 72, 3168–3184.

Frozen in the dark: night activity of xanthophyll cycle, xylem attributes and desiccation-tolerance interplay in fern resistance to winter

2021 ◽  
Author(s):  
Beatriz Fernández-Marín ◽  
Miren Irati Arzac ◽  
Marina López-Pozo ◽  
José Manuel Laza ◽  
Thomas Roach ◽  
...  
Keyword(s):  
Freezing Tolerance ◽  
Desiccation Tolerance ◽  
Xanthophyll Cycle ◽  
Photochemical Efficiency ◽  
Photochemical Efficiency Of Psii ◽  
Tolerant Species ◽  
Fern Species ◽  
Propagation Pattern ◽  
The Tropics ◽  
First Time

Abstract While most ferns avoid freezing by living in the tropics or shedding their fronds, wintergreen species in temperate and boreoalpine ecosystems deal with sub-zero temperatures. Increasing evidence has revealed overlapping mechanisms of desiccation and freezing-tolerance in angiosperms, but physiological mechanisms behind freezing tolerance in ferns are far from clear. We evaluated photochemical and hydraulic parameters in five wintergreen fern species, differing in their ability to tolerate desiccation. We assessed frond freezing tolerance, ice nucleation temperature and propagation pattern, and xylem anatomical traits. Dynamics of photochemical performance and xanthophyll cycle were evaluated during freeze-thaw events under controlled conditions and, in selected species, in the field. Only desiccation-tolerant species, which possessed greater fractions of narrow tracheids (<18 μm) than sensitive species, tolerated freezing. Frond freezing occurred in the field at –3.4 ± 0.9 ºC (SD) irrespective of freezing-tolerance, freezable water content or tracheid properties. Even in complete darkness, maximal photochemical efficiency of PSII was down-regulated concomitantly with zeaxanthin accumulation in response to freezing. This was reversible upon re-warming in tolerant species only. Our results suggest that adaptation to freezing-tolerance is associated with desiccation-tolerance, by means of complementary xylem properties (that may prevent risk of irreversible cavitation) and effective photoprotection mechanisms. The latter includes de-epoxidation of xanthophylls in darkness, a process evidenced for the first time directly in the field.

THE EFFECT OF PROMAZINE ON THE ACTIVITY LEVEL OF RETARDED CHILDREN

PEDIATRICS ◽  
1964 ◽  
Vol 33 (2) ◽  
pp. 271-275
Author(s):  
Jerome L. Schulman ◽  
Sister Mary Clarinda
Keyword(s):  
Activity Level ◽  
Blind Study ◽  
Double Blind Study ◽  
Night Time ◽  
Double Blind ◽  
Time Activity ◽  
Drug Levels ◽  
Daytime Activity ◽  
Dose Levels

Promazine was administered to six hyperactive retarded boys in a long-term double-blind study. There were four dose levels —40, 60, 80, and 160 mg per day. The effect on activity level was measured with actometers. There was no effect on daytime activity when the placebo and drug levels were compared. There was a significant but clinically unimportant effect on night time activity.

scholarly journals Governing the night-time city: The rise of night mayors as a new form of urban governance after dark

Urban Studies ◽  
2020 ◽  
pp. 004209801989522
Author(s):  
Andreina Seijas ◽  
Mirik Milan Gelders
Keyword(s):  
Urban Governance ◽  
New Wave ◽  
Geographic Variations ◽  
Night Time ◽  
Time Activity ◽  
The Past ◽  
Industrial Cities ◽  
Position Data ◽  
Traditional Approaches ◽  
Post Industrial

The urban night has traditionally been a regimented space characterised by strict policing and surveillance. Early research on the night-time economy documented the expansion of nightlife from a centrepiece of culture-led redevelopment strategies in post-industrial cities, to the introduction of a broad governance apparatus to manage the agglomeration of night-time activity. Over the past two decades, a new actor has emerged: more than 40 cities have appointed night mayors or individuals responsible for maintaining nocturnal vibrancy, while mediating between those who wish to work, party or sleep. This article summarises the results of a qualitative study that gathered information on the origins, propagation and geographic variations in the role to provide a first comprehensive look at this position. Data from 35 night mayors and night-time advocacy organisations from around the world revealed that, though cities differ greatly in their approach towards night-time infrastructure and regulation, there seems to be growing consensus on the need for permanent nocturnal governance structures. By encouraging greater dialogue and experimentation, these structures are challenging traditional approaches to urban governance and paving the way for a new wave of studies on the urban night.

scholarly journals Short term effect of treating claw horn lesions in dairy cattle on their locomotion, activity and milk yield

2012 ◽  
Vol 2 (1) ◽  
pp. 7 ◽  
Author(s):  
Jane A. Montgomery ◽  
Katie Forgan ◽  
Catherine Hayhurst ◽  
Elizabeth Rees ◽  
Jennifer S. Duncan ◽  
...  
Keyword(s):  
Milk Yield ◽  
Daily Activity ◽  
Activity Levels ◽  
Night Time ◽  
White Line ◽  
Time Activity ◽  
Milk Flow ◽  
Ulcer Haemorrhage ◽  
Locomotion Activity ◽  
Locomotion Score

The immediate effect on dairy cow mobility, daily activity and milk yield following treatment for claw horn disease was examined in 306 lame cows located on four Cheshire dairy farms over twelve months. The daily activity and milk yield of all cows in these herds was recorded on computer using pedometers and in-parlour milk flow meters. Lame cows identified by stockmen were assessed subjectively by locomotion score, then restrained and their claws examined to identify the predominant lesion present. Those with locomotion scores &gt; 2.5 that presented with sole ulcer, haemorrhage and bruising, or white line disease were studied. Claws of the affected limb were trimmed by one paraprofessional claw trimmer using the five-step <em>Dutch method </em>and the affected claw unloaded either by trimming or application of a block to the healthy digit: those on the contra-lateral limb were trimmed similarly. The same observer repeated the locomotion score assessment seven days later: trimming reduced the proportion of lame cows (score &gt;3) by 55% and those with poor gait (score &lt;3&gt;2.5) by 49%, and the proportion of all cows not lame after trimming was 51% (χ2 4.94: P≤0.001). Night time activity levels increased from 76 to 81 steps/hour on day 2 after treatment (P&lt;0.05) but this was not maintained: daily milk yields fell by 2%. Using univariate mixed models, year and season, parity and farm all had significant effects on locomotion and activity levels. This treatment for claw horn disease in lame dairy cows improved their immediate health and welfare.

scholarly journals Monitoring and visualising of night time activity patterns of people with early dementia

2011 ◽  
Vol 11 (6) ◽  
Author(s):  
Huiru Zheng ◽  
Haiying Wang ◽  
Haiying Wang ◽  
Paul Jeffers ◽  
Paul Jeffers ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Night Time ◽  
Time Activity ◽  
Early Dementia

scholarly journals Autumn Warming Delays the Downregulation of Photosynthesis and Does Not Increase the Risk of Freezing Damage in Interior and Coastal Douglas-fir

2021 ◽  
Vol 4 ◽  
Author(s):  
Devin Noordermeer ◽  
Vera Marjorie Elauria Velasco ◽  
Ingo Ensminger
Keyword(s):  
Cold Acclimation ◽  
Freezing Tolerance ◽  
Xanthophyll Cycle ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Photosynthetic Activity ◽  
Elevated Temperatures ◽  
Douglas Fir ◽  
The Impact ◽  
Xanthophyll Cycle Pigment

During autumn, evergreen conifers utilize the decrease in daylength and temperature as environmental signals to trigger cold acclimation, a process that involves the downregulation of photosynthesis, upregulation of photoprotection, and development of cold hardiness. Global warming will delay the occurrence of autumn low temperatures while daylength remains unaffected. The impact of autumn warming on cold acclimation and the length of the carbon uptake period of species with ranges that encompass diverse climates, such as Douglas-fir (Pseudotsuga menziesii), remains unclear. Our study investigated intraspecific variation in the effects of autumn warming on photosynthetic activity, photosynthetic pigments, and freezing tolerance in two interior (var. glauca) and two coastal (var. menziesii) Douglas-fir provenances. Following growth under simulated summer conditions with long days (16 h photoperiod) and summer temperatures (22/13°C day/night), Douglas-fir seedlings were acclimated to simulated autumn conditions with short days (8 h photoperiod) and either low temperatures (cool autumn, CA; 4/−4°C day/night) or elevated temperatures (warm autumn, WA; 19/11°C day/night). Exposure to low temperatures in the CA treatment induced the downregulation of photosynthetic carbon assimilation and photosystem II efficiency, increased the size and de-epoxidation of the xanthophyll cycle pigment pool, and caused the development of sustained nonphotochemical quenching (NPQ). Seedlings in the WA treatment exhibited no downregulation of photosynthesis, no change in xanthophyll cycle pigment de-epoxidation, and no development of sustained NPQ. Albeit these changes, freezing tolerance was not impaired under WA conditions compared with CA conditions. Interior Douglas-fir seedlings developed greater freezing tolerance than coastal seedlings. Our findings suggest that autumn warming, i.e., short photoperiod alone, does not induce the downregulation of photosynthesis in Douglas-fir. Although autumn warming delays the downregulation of photosynthesis, the prolonged period of photosynthetic activity does not bear a trade-off of impaired freezing tolerance.

Night-Time Activity and Daytime Pain in Patients with Chronic Back Pain

2002 ◽  
Vol 96 (Sup 2) ◽  
pp. A865
Author(s):  
David P. Martin ◽  
John J. Liszka-Hackzell
Keyword(s):  
Back Pain ◽  
Chronic Back Pain ◽  
Night Time ◽  
Time Activity

Observations on the 24 hour activity patterns of stabled horses

2007 ◽  
Vol 2007 ◽  
pp. 34-34
Author(s):  
JJ Cooper ◽  
J. Campbell ◽  
P. Harris
Keyword(s):  
Activity Patterns ◽  
Laboratory Mice ◽  
Dark Cycle ◽  
Night Time ◽  
Low Light ◽  
Time Activity ◽  
Video Cameras ◽  
Low Intensity ◽  
Infra Red ◽  
Laboratory Workers

Activity patterns of domesticated animals have largely focussed on hours of daylight and relatively few studies include detailed observations of night time activity. This has the potential to overlook behaviours of significance to the assessment of welfare. For example, stereotypic activities in laboratory mice are largely confined to dark periods, and consequently are not commonly reported by daytime laboratory workers. Use of low light video cameras coupled with infra-red or low intensity lighting now makes observation over entire light-dark cycle practical, whilst minimising disturbance to the sampled population. This paper describes the activity patterns of stabled horses over 24 hour periods. These observations can then be used as baseline for investigating the effects of changes to the stable environment on horses’ behaviour and welfare.

Autumn warming delays downregulation of photosynthesis and does not increase risk of freezing damage in interior and coastal Douglas-fir seedlings

2020 ◽  
Author(s):  
Devin Noordermeer ◽  
Vera Velasco ◽  
Ingo Ensminger
Keyword(s):  
Low Temperature ◽  
Freezing Tolerance ◽  
Xanthophyll Cycle ◽  
Photosynthetic Activity ◽  
Nonphotochemical Quenching ◽  
Douglas Fir ◽  
Cold Hardening ◽  
Freezing Damage ◽  
Increase Risk ◽  
Xanthophyll Cycle Pigment

&lt;p&gt;In the next several decades, warming in the northern hemisphere will result in asynchronous phasing between the temperature and photoperiod signals that evergreen conifers rely upon for cold hardening during autumn. Our study investigated intraspecific variation in photosynthetic and photoprotective mechanisms in Douglas-fir (Pseudotsuga menziesii) originating from contrasting climates during simulated summer and autumn conditions, as well as how autumn warming affects downregulation of photosynthesis and development of cold hardening. Following growth under long days and summer temperature (LD/ST; 16 h photoperiod; 22 &amp;#176;C/13 &amp;#176;C day/night), Douglas-fir seedlings from two interior and two coastal provenances were acclimated to simulated autumn conditions with short days and either low temperature (SD/LT; 8 h photoperiod; 4 &amp;#176;C/-4 &amp;#176;C day/night) or high temperature (SD/HT; 8 h photoperiod; 19 &amp;#176;C/11 &amp;#176;C day/night). Exposure to low temperature induced increase in size and de-epoxidation of the xanthophyll cycle pigment pool, development of sustained nonphotochemical quenching, and downregulation of photosynthetic activity. SD/HT seedlings exhibited no downregulation of photosynthesis, corresponding with no change in xanthophyll cycle pigment de-epoxidation and no development of sustained nonphotochemical quenching. However, freezing tolerance development for all provenances was not impaired under SD/HT relative to SD/LT. Interior Douglas-fir provenances developed greater freezing tolerance relative to coastal provenances under both temperature treatments. Our findings suggest that short photoperiod alone is insufficient to induce downregulation of photosynthesis in autumn for Douglas-fir. However, this prolonged period of photosynthetic activity does not appear to bear a trade-off of impaired freezing tolerance.&lt;/p&gt;

scholarly journals Predicting personality from patterns of behavior collected with smartphones

2020 ◽  
Vol 117 (30) ◽  
pp. 17680-17687 ◽  
Author(s):  
Clemens Stachl ◽  
Quay Au ◽  
Ramona Schoedel ◽  
Samuel D. Gosling ◽  
Gabriella M. Harari ◽  
...  
Keyword(s):  
Big Five ◽  
Behavioral Data ◽  
Big Five Personality ◽  
Night Time ◽  
Time Activity ◽  
Individual Privacy ◽  
Machine Learning Approach ◽  
Social Media Platforms ◽  
Patterns Of Behavior ◽  
Broad Domain

Smartphones enjoy high adoption rates around the globe. Rarely more than an arm’s length away, these sensor-rich devices can easily be repurposed to collect rich and extensive records of their users’ behaviors (e.g., location, communication, media consumption), posing serious threats to individual privacy. Here we examine the extent to which individuals’ Big Five personality dimensions can be predicted on the basis of six different classes of behavioral information collected via sensor and log data harvested from smartphones. Taking a machine-learning approach, we predict personality at broad domain (rmedian= 0.37) and narrow facet levels (rmedian= 0.40) based on behavioral data collected from 624 volunteers over 30 consecutive days (25,347,089 logging events). Our cross-validated results reveal that specific patterns in behaviors in the domains of 1) communication and social behavior, 2) music consumption, 3) app usage, 4) mobility, 5) overall phone activity, and 6) day- and night-time activity are distinctively predictive of the Big Five personality traits. The accuracy of these predictions is similar to that found for predictions based on digital footprints from social media platforms and demonstrates the possibility of obtaining information about individuals’ private traits from behavioral patterns passively collected from their smartphones. Overall, our results point to both the benefits (e.g., in research settings) and dangers (e.g., privacy implications, psychological targeting) presented by the widespread collection and modeling of behavioral data obtained from smartphones.

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