The Impact of Size-Selective Predation on Competition between two Daphnia Species: A Laboratory Study

10.2307/5428 ◽  
1991 ◽  
Vol 60 (3) ◽  
pp. 1009 ◽  
Author(s):  
Goran Milbrink ◽  
Jan Bengtsson
Keyword(s):  
Laboratory Study ◽  
Selective Predation ◽  
Daphnia Species ◽  
The Impact

scholarly journals Sleep Deprivation and Sleep-Onset Insomnia are Associated with Blunted Physiological Reactivity to Stressors

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 246-252
Author(s):  
Devon A Hansen ◽  
Brieann C Satterfield ◽  
Matthew E Layton ◽  
Hans P A Van Dongen
Keyword(s):  
Sleep Deprivation ◽  
Laboratory Study ◽  
Salivary Cortisol ◽  
Sleep Onset ◽  
Deprivation Condition ◽  
Increased Risk ◽  
Significant Difference ◽  
Sleep Deficiency ◽  
The Impact ◽  
Chronic Sleep

ABSTRACT Introduction Military operations often involve intense exposure to stressors combined with acute sleep deprivation, while military personnel also experience high prevalence of chronic sleep deficiency from insomnia and other sleep disorders. However, the impact of acute and chronic sleep deficiency on physiologic stressor responses is poorly understood. In a controlled laboratory study with normal sleepers and individuals with chronic sleep-onset insomnia, we measured responses to an acute stressor administered in a sleep deprivation condition or a control condition. Methods Twenty-two adults (aged 22-40 years; 16 females)—11 healthy normal sleepers and 11 individuals with sleep-onset insomnia—completed a 5-day (4-night) in-laboratory study. After an adaptation day and a baseline day, subjects were assigned to a 38-hour total sleep deprivation (TSD) condition or a control condition; the study ended with a recovery day. At 8:00 PM after 36 hours awake in the sleep deprivation condition or 12 hours awake in the control condition, subjects underwent a Maastricht Acute Stress Test (MAST). Salivary cortisol was measured immediately before the MAST at 8:00 PM, every 15 minutes after the MAST from 8:15 PM until 9:15 PM, and 30 minutes later at 9:45 PM. Baseline salivary cortisol was collected in the evening of the baseline day. Additionally, before and immediately upon completion of the MAST, self-report ratings of affect and pain were collected. Results The MAST elicited a stressor response in both normal sleepers and individuals with sleep-onset insomnia, regardless of the condition, as evidenced by increases in negative affect and pain ratings. Relative to baseline, cortisol levels increased immediately following the MAST, peaked 30 minutes later, and then gradually returned to pre-MAST levels. At the cortisol peak, there was a significant difference across groups and conditions, reflecting a pronounced blunting of the cortisol response in the normal sleepers in the TSD condition and the sleep-onset insomnia group in both the TSD and control conditions. Conclusions Blunted stressor reactivity as a result of sleep deficiency, whether acute or chronic, may reflect reduced resiliency attributable to allostatic load and may put warfighters at increased risk in high-stakes, rapid response scenarios.

The impact of Saccharomyces and non-Saccharomyces yeasts on wine colour: A laboratory study of vinylphenolic pyranoanthocyanin formation and anthocyanin cell wall adsorption

LWT ◽  
2020 ◽  
Vol 123 ◽  
pp. 109072 ◽  
Author(s):  
Jelena Topić Božič ◽  
Lorena Butinar ◽  
Alen Albreht ◽  
Irena Vovk ◽  
Dorota Korte ◽  
...  
Keyword(s):  
Cell Wall ◽  
Laboratory Study ◽  
Wine Colour ◽  
The Impact ◽  
Saccharomyces Yeasts

scholarly journals Whiteflies Provide Honeydew to Camponotus ants Without Receiving Reciprocal Favor

Sociobiology ◽  
2016 ◽  
Vol 63 (2) ◽  
pp. 755
Author(s):  
Raí Martins De Jesus ◽  
Ramon Paes Junior ◽  
Gleicy Do Carmo ◽  
Danilo Mota ◽  
Lessando Moreira Gontijo ◽  
...  
Keyword(s):  
Biological Control ◽  
Host Plant ◽  
Laboratory Study ◽  
Natural Enemies ◽  
Predator Cues ◽  
Sooty Mold ◽  
Field Laboratory ◽  
Important Pest ◽  
The Impact

The notion that tending ants provide protection to honeydew-producing hemipterans is widely accepted. Nevertheless, there have been debates about whether or not this protection can always disrupt the biological control of hemipterans. Although various hemipteran species interact with tending ants, most studies have focused on the mutualism between ants and aphids.  Woolly whitefly Aleurothrixus floccosus (Maskell) is an important pest of citrus whose nymphs are frequently tended by ants such as Camponotus. However, it is unknown whether or not ants in this genus can disrupt biological control of woolly whitefly by protecting this pest’s nymphs from natural enemies. We investigated the impact of Camponotus ants on the biological control of woolly whitefly in the field by excluding or allowing the access of ants to whitefly nymph colonies in different tangerine trees. Furthermore, in a laboratory study we also assessed the behavior of Camponotus ants in response to woolly whitefly’s common predator cues (visual and scent).  In summary, this field-laboratory study suggests that there is no mutualism between tending Camponotus ants and the whitefly A. floccosus; rather it indicates commensalism as an alternative interaction. Interactions as this may provide more benefits for the host plant, whereby Camponotus ants can reduce sooty mold by removing honeydew from the leaves and favor pest biological control by leaving the whiteflies unprotected.

Laboratory Study of the Impact of the Cathode Grade on the Formation of Deposits on the Cathode Surface in Hall-Héroult Cells

2018 ◽  
pp. 1229-1233 ◽  
Author(s):  
Jean-René Landry ◽  
Mojtaba Fallah Fini ◽  
Gervais Soucy ◽  
Martin Désilets ◽  
Patrick Pelletier ◽  
...  
Keyword(s):  
Laboratory Study ◽  
Cathode Surface ◽  
The Impact

Laboratory study of the impact of evaporative coolers on indoor PM concentrations

2003 ◽  
Vol 37 (8) ◽  
pp. 1075-1086 ◽  
Author(s):  
Helmut Paschold ◽  
Wen-Whai Li ◽  
Hugo Morales ◽  
John Walton
Keyword(s):  
Laboratory Study ◽  
The Impact
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