scholarly journals Effects of Heat Stress on Mating Behavior and Colony Development in Bombus terrestris (Hymenoptera: Apidae)

2021 ◽  
Vol 9 ◽  
Author(s):  
Kimberly Przybyla ◽  
Denis Michez ◽  
Ella Zambra ◽  
Abigaël Anselmo ◽  
Elise Hennebert ◽  
...  
Keyword(s):  
Heat Waves ◽  
Bombus Terrestris ◽  
Heat Exposure ◽  
Colony Development ◽  
Experimental Protocol ◽  
Sensitive Species ◽  
Copulation Behavior ◽  
And Control ◽  
Virgin Queens ◽  
The Impact

Climate change is related to an increase in the frequency and intensity of extreme events such as heatwaves. In insect pollinators, heat exposure is associated with direct physiological perturbations, and in several species, could lead to a decrease of fitness related to a decrease in fertility. Here we developed a new experimental protocol in controlled conditions to assess if the exposure to high temperatures could modify the attractiveness and fertility of Bombus terrestris males. Our results show that virgin queens of B. terrestris do not have preferences between the pheromonal secretions of heat-exposed and control males. Moreover, mating with a heat-exposed male has no impact on the copulation behavior and the development of the nest (brood composition). We advise to extend trials to cover a range of wild and heat-sensitive species on multiple generations to better understand the impact of heat waves on the bumblebee communities.

scholarly journals Hormonal and Pheromonal Regulation of Reproduction in the Bumble Bee Bombus terrestris

1994 ◽  
Author(s):  
Abraham Hefetz ◽  
Gene Robinson
Keyword(s):  
Ovarian Development ◽  
Bombus Terrestris ◽  
Worker Reproduction ◽  
Colony Development ◽  
Social Species ◽  
Before And After ◽  
High Aggression ◽  
Total Body ◽  
Virgin Queens ◽  
The Brain

Bombus terrestris constitute important pollinators of greenhouse crops. In Israel the species utilized is, whose colonies are reared commercially. This is a primitively social species with a particular colony development. It encompasses two social phases: a eusocial phase in which the queen dominates reproduction, and a competition phase in which workers compete with the queen for the parentage of males. These workers are distinguished by accelerated ovarian development, high production of JH, and elevated levels of dopamine in the brain. Queen-worker conflict is also manifested in overt aggression among all members of the nest. High aggression is correlated with dominance status of the bees and is also correlated with octopamine levels in the brain. After verifying that JH III is the only JH produced by the bees and validating the assay for its measurements (RCA & RIA), we used JH as an indicator of worker reproduction. Queens taken from colonies both before and after the competition phase were equally effective in inhibiting worker reproduction. Moreover, there is only a narrow window, around the competition point, in which workers may have the opportunity to initiate reproduction. Before that point they are inhibited by the dominant queen, while after that point both the queen and those workers with accelerated ovarian development exert strong inhibition on worker nest mates. Thus, "queen dominance deterioration" is not the primary cause in eliciting the queen-worker conflict. Queens convey their presence by means of a chemical signal that is extractable in organic solvent and that is normally spread on the cuticle. Total body extract and body washes, applied on dead virgin queens, were able to inhibit the release of JHin vitro in queenless workers. However, none of the prominent exocrine gland investigated mimicked this function. It is possible that the source of the putative pheromone is an unknown gland, or that it emanates from an assembly of glands. Chemical analyses of the prominent glands revealed a plethora of compounds the function of which should be further investigated. Understanding the social behavior of B. terrestris paves the way to facilitate colony manipulation and to adjust the colonies for specific pollination requirements.

scholarly journals Worker-Born Males Are Smaller but Have Similar Reproduction Ability to Queen-Born Males in Bumblebees

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1008
Author(s):  
Huiyue Zhao ◽  
Yanjie Liu ◽  
Hong Zhang ◽  
Tom D. Breeze ◽  
Jiandong An
Keyword(s):  
Bombus Terrestris ◽  
Morphological Characteristics ◽  
Worker Reproduction ◽  
Egg Laying ◽  
Colony Development ◽  
Eusocial Insects ◽  
Reproductive Ability ◽  
Evolution Of Sociality ◽  
Sperm Counts ◽  
Virgin Queens

Queen-worker conflict over the reproduction of males exists in the majority of haplodiplioidy hymenpteran species such as bees, wasps, and ants, whose workers lose mating ability but can produce haploid males in colony. Bumblebee is one of the representatives of primitively eusocial insects with plastic division labor and belongs to monandrous and facultative low polyandry species that have reproductive totipotent workers, which are capable of competing with mother queen to produce haploid males in the queenright colony compared to higher eusocial species, e.g., honeybees. So, bumblebees should be a better material to study worker reproduction, but the reproductive characteristics of worker-born males (WMs) remain unclear. Here, we choose the best-studied bumblebee Bombus terrestris to evaluate the morphological characteristics and reproductive ability of WMs from the queenless micro-colonies. The sexually matured WMs showed smaller in forewing length and weight, relatively less sperm counts but equally high sperm viability in comparison with the queen-born males (QMs) of the queenright colony. Despite with smaller size, the WMs are able to successfully mate with the virgin queens in competition with the QMs under laboratory conditions, which is quite different from the honeybees reported. In addition, there was no difference in the colony development, including the traits such as egg-laying rate, colony establishment rate, and populations of offspring, between the WM- and the QM-mated queens. Our study highlights the equivalent reproductive ability of worker-born males compared to that of queens, which might exhibit a positive application or special use of bumblebee rearing, especially for species whose males are not enough for copulation. Further, our finding contributes new evidence to the kin selection theory and suggests worker reproduction might relate to the evolution of sociality in bees.

scholarly journals Impairments to Thermoregulation in the Elderly During Heat Exposure Events

2020 ◽  
Vol 6 ◽  
pp. 233372142093243
Author(s):  
Alison Millyard ◽  
Joe D. Layden ◽  
David B. Pyne ◽  
Andrew M. Edwards ◽  
Saul R. Bloxham
Keyword(s):  
Hospital Admissions ◽  
Heat Waves ◽  
Heat Exposure ◽  
The Elderly ◽  
Physiological Strain ◽  
Reducing Ability ◽  
Health Related ◽  
Heat Perception ◽  
Wave Induced ◽  
The Impact

Heat waves represent a public health risk to elderly people, and typically result in an increased rate of hospital admissions and deaths. Studies of thermoregulation in this cohort have generally focused on single elements such as sweating capacity. Sweating capacity and skin blood flow reduce with age, reducing ability to dissipate heat. Perception of effort during heat exposure is emerging as an area that needs further investigation as the elderly appear to lack the ability to adequately perceive increased physiological strain during heat exposure. The role of the gut and endotoxemia in heat stress has received attention in young adults, while the elderly population has been neglected. This shortcoming offers another potential avenue for identifying effective integrated health interventions to reduce heat illnesses. Increasing numbers of elderly individuals in populations worldwide are likely to increase the incidence of heat wave-induced deaths if adequate interventions are not developed, evaluated, and implemented. In this narrative-style review we identify and discuss health-related interventions for reducing the impact of heat illnesses in the elderly.

scholarly journals Protocol for creating new warnings on cigarette packs and evaluating their efficacy in a randomised experimental setting

BMJ Open ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. e036166
Author(s):  
Christian Ben Lakhdar ◽  
Antoine Deplancke ◽  
Fabrice Le Lec ◽  
Sophie Massin ◽  
Anthony Piermatteo ◽  
...  
Keyword(s):  
Monetary Incentives ◽  
Experimental Setting ◽  
Experimental Protocol ◽  
Control Groups ◽  
Reliable Measure ◽  
Subjective Value ◽  
Scientific Meetings ◽  
And Control ◽  
The Impact ◽  
Cigarette Packs

IntroductionTobacco smoking is one of the leading causes of preventable death. This is not inevitable as tobacco control tools have become more powerful and more effective. Among these, warnings on cigarette packs have proven to be somewhat effective. Our objective is to increase the efficacy of antismoking warnings by using innovative psychological approaches and to create an experimental setting for the evaluation of these new warnings based on behavioural indicators.Methods and analysisFirst, we created new warnings based on three categories of motivational leverage and on harm reduction. New warnings with innovative texts and pictures were designed for each category and inserted on plain packs. We will then use standard indicators to compare their effect to that of control packs: plain pack without warning, plain pack with conventional warning and branded pack with conventional warning. Second, the novelty of our approach will consist in designing an experimental protocol that uses monetary incentives to evaluate the effect of warnings. Subjects will be able to ‘sacrifice’ part of their participation defrayal to purchase a good whose subjective value is related to one’s attitude towards smoking. These monetarily incentivised measures are designed to assess smokers’ immediate/mid-term intention to quit and non-smokers’ aversion to smoking. In both cases, the monetary amounts individuals accept to sacrifice may be a more reliable measure than declarative responses, which may be distorted by several hypothetical biases. In the end, we should be able to robustly measure the impact of our new warnings between intervention and control groups by using both traditional indicators and our new monetarily incentivised measure.Ethics and disseminationThe ethics committee of the Groupement des Hôpitaux de l’Institut Catholique de Lille approved the research protocol on 5 July 2019 (CIER 2019-22). Results will be presented at scientific meetings and published.

Climate Change, Heat Waves and Thermal Comfort—Reflections on Housing Policy in India

2020 ◽  
Vol 11 (1) ◽  
pp. 29-50 ◽  
Author(s):  
Darshini Mahadevia ◽  
Minal Pathak ◽  
Neha Bhatia ◽  
Shaurya Patel
Keyword(s):  
Climate Change ◽  
Low Income ◽  
Heat Waves ◽  
Heat Exposure ◽  
Urban Housing ◽  
Economic Benefits ◽  
Housing Quality ◽  
Informal Housing ◽  
The Right ◽  
The Impact

Housing ideally supplies many physical comforts, social and economic benefits, as well as forms the basis for the right to the city. It also addresses an additional challenge of adaptation to the current as well as expected impacts of climate change—one of them being heat waves—especially in the context of developing countries like India. Few studies in the Indian context have explicitly examined the experience of heat on the indoor temperatures linked to the housing quality and typologies and the quality of the surroundings. Official state and urban policies do not explicitly include heatproofing for existing or new housing to address indoor heat exposure, especially in the case of vulnerable populations. We have measured the indoor and outdoor temperatures in 860 low-income residents living in three different housing typologies in 26 settlements (formal and informal) of Ahmedabad, India, in peak summer months. Building the case for a long-term urban housing strategy to address the impact of indoor temperature particularly for low-income households and residents of informal housing, we argue that conscious and deliberate efforts towards heatproofing existing informal housing are required. One of the options, which is being pursued currently, is transiting informal housing dwellers to formal housing. But, another one for immediate consideration is renewal of current informal housing due to limited coverage possibility of the first option.

Analysis of wind resource under heat wave conditions in southern Europe

2021 ◽  
Author(s):  
María Ofelia Molina ◽  
Enrique Sánchez ◽  
Claudia Gutiérrez ◽  
María Ortega
Keyword(s):  
Energy Demand ◽  
Heat Waves ◽  
Energy System ◽  
High Energy ◽  
Planning And Control ◽  
High Penetration ◽  
Using Data ◽  
And Control ◽  
Wind Resource ◽  
The Impact

<p>In recent years, renewable energy is gaining importance in the energy mix, increasing the dependence of the energy system on weather. Atmospheric patterns that affect wind energy production focusing on the winter months have been studied in previous works, as wind resource in Europe is higher for this season, but also because it is when there is a greater and more stable heating demand in Europe. Southern European countries, however, present summer demand increases due to the cooling needs of these countries (Spain, Portugal , Italy and Greece). These increases have been seen with real daily demand data from ENTSO-E (the European Network of Transmission System Operators for Electricity). Demand in Spain is even higher on days of heat waves in the 2015-2018 period, reaching in that case the annual maxima. The objective of this work is to study the wind patterns in these episodes of heat waves. Reduced overall summer wind power supply coupled with high energy demand under these conditions could be compromised. We will analyse means of daily wind anomalies on days of heat waves (composites) using data from the ERA5 reanalysis and the E-OBS temperature observations. The study of the wind resource in conditions of high energy demand due to extreme climate events, can help in the energy supply strategic planning and control to minimize the impact of these events on an electricity system with high penetration of renewables.</p><p> </p>

scholarly journals Higher developmental temperature increases queen production and decreases worker body size in the bumblebee Bombus terrestris

2021 ◽  
Vol 88 ◽  
pp. 39-49
Author(s):  
Marie Guiraud ◽  
Bérénice Cariou ◽  
Maxime Henrion ◽  
Emily Baird ◽  
Maxence Gérard
Keyword(s):  
Life History ◽  
Body Size ◽  
Elevated Temperatures ◽  
Negative Impact ◽  
Bombus Terrestris ◽  
Reproductive Investment ◽  
Colony Development ◽  
Resource Collection ◽  
Queen Production ◽  
The Impact

Climate change and increasing average temperatures are now affecting most ecosystems. Social insects such as bumblebees are especially impacted because these changes create spatial, temporal and morphological mismatches that could impede their ability to find food resources and mate. However, few studies have assessed how the colony and life cycle are affected when temperatures rise above optimal rearing temperature. It has become imperative to understand how heat stress affects the life history traits of insect pollinators as well as how changes in life history interact with other traits like morphology. For example, a decrease in the number of foraging workers could be balanced by producing larger workers, able to forage at longer distances and gather more resources. Here, we investigated the impact of temperature on colony production and body size in the bumblebee Bombus terrestris. Colonies were exposed to two temperatures: 25 °C, which is around the optimal temperature for larval development and 33 °C, which is slightly above the set-point that is considered stressful for bumblebees. Although the production of males and workers wasn’t significantly affected by these different temperatures, queen production and reproductive investment were much higher for colonies placed in 33 °C than in 25 °C. We also found that, in agreement with the temperature-size rule, workers were significantly smaller in the higher temperature. The decrease in worker body size could affect resource collection and pollination if their foraging distance and the quantity of food they are taking back to the colony decreases. While in our controlled conditions the bumblebees were fed ad libitum, the decrease of resource collection in field conditions could prevent colonies from producing as many queens as in our study. Together with the decrease of worker body size, our results suggest that elevated temperatures could ultimately have a negative impact on bumblebee colony fitness. Indeed, smaller workers are known to have weaker flight performance which could affect foraging performance and consequently colony development.

Suppressed, but Not Forgotten

2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke
Keyword(s):  
Memory Trace ◽  
Thought Suppression ◽  
Test Phase ◽  
Indirect Test ◽  
Final Test ◽  
Test Experiment ◽  
And Control ◽  
Cue Words ◽  
The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

Research Participation Experiences of Informants of Suicide and Control Cases

Crisis ◽  
2010 ◽  
Vol 31 (5) ◽  
pp. 238-246 ◽  
Author(s):  
Paul W. C. Wong ◽  
Wincy S. C. Chan ◽  
Philip S. L. Beh ◽  
Fiona W. S. Yau ◽  
Paul S. F. Yip ◽  
...  
Keyword(s):  
Ethical Issues ◽  
Research Participation ◽  
Self Report ◽  
Initial Contact ◽  
Psychological Autopsy ◽  
Autopsy Study ◽  
The People ◽  
And Control ◽  
The Impact

Background: Ethical issues have been raised about using the psychological autopsy approach in the study of suicide. The impact on informants of control cases who participated in case-control psychological autopsy studies has not been investigated. Aims: (1) To investigate whether informants of suicide cases recruited by two approaches (coroners’ court and public mortuaries) respond differently to the initial contact by the research team. (2) To explore the reactions, reasons for participation, and comments of both the informants of suicide and control cases to psychological autopsy interviews. (3) To investigate the impact of the interviews on informants of suicide cases about a month after the interviews. Methods: A self-report questionnaire was used for the informants of both suicide and control cases. Telephone follow-up interviews were conducted with the informants of suicide cases. Results: The majority of the informants of suicide cases, regardless of the initial route of contact, as well as the control cases were positive about being approached to take part in the study. A minority of informants of suicide and control cases found the experience of talking about their family member to be more upsetting than expected. The telephone follow-up interviews showed that none of the informants of suicide cases reported being distressed by the psychological autopsy interviews. Limitations: The acceptance rate for our original psychological autopsy study was modest. Conclusions: The findings of this study are useful for future participants and researchers in measuring the potential benefits and risks of participating in similar sensitive research. Psychological autopsy interviews may be utilized as an active engagement approach to reach out to the people bereaved by suicide, especially in places where the postvention work is underdeveloped.

Using Work Domain Analysis to Evaluate the Impact of Digitization on Command and Control

2008 ◽  
Author(s):  
Daniel P. Jenkins ◽  
Neville A. Stanton ◽  
Paul M. Salmon ◽  
Guy H. Walker
Keyword(s):  
Command And Control ◽  
Domain Analysis ◽  
Work Domain Analysis ◽  
And Control ◽  
The Impact ◽  
Work Domain
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