Wild clocks: preface and glossary

No abstract available

Behavioral Responses to Combinations of Timed Light, Food Availability, and Ultradian Rhythms in the Common Vole (Microtus arvalis)

Light is the main entraining signal of the central circadian clock, which drives circadian organization of activity. When food is made available during only certain parts of the day, it can entrain the clock in the liver without changing the phase of the central circadian clock. Although a hallmark of food entrainment is a behavioral anticipation of food availability, the extent of behavioral alterations in response to food availability has not been fully characterized. The authors have investigated interactions between light and temporal food availability in the timing of activity in the common vole. Temporally restricted food availability enhanced or attenuated re-entrainment to a phase advance in light entrainment when it was shifted together with the light or remained at the same time of day, respectively. When light-entrained behavior was challenged with temporal food availability cycles with a different period, two distinct activity components were observed. More so, the present data indicate that in the presence of cycles of different period length of food and light, an activity component emerged that appeared to be driven by a free-running (light-entrainable) clock. Because the authors have previously shown that in the common vole altering activity through running-wheel availability can alter the effectiveness of food availability to entrain the clock in the liver, the authors included running-wheel availability as a parameter that alters the circadian/ultradian balance in activity. In the current protocols, running-wheel availability enhanced the entraining potential of both light and food availability in a differential way. The data presented here show that in the vole activity is a complex of individually driven components and that this activity is, itself, an important modulator of the effectiveness of entraining signals such as light and food. (Author correspondence: [email protected]

The role of traditional knowledge policies in Egypt:The case of Wadi Allaqi

Globally, traditional knowledge is at stake, notwithstanding intentions recorded in international policy conventions. Egypt has accepted and ratifed several conventions on implementation of traditional knowledge in the felds of environment and sustainable development; yet this implementation is hampered by a lack of concrete plans. Focusing on the Bedouin community in the Southern Egypt protectorate of Wadi Allaqi, this paper investigates whether traditional knowledge plays a role in Egyptian policy, as refected in policy documents and by interviews with regional stakeholders. We found that local actors of Wadi Allaqi protectorate-involved institutions appreciate the importance of traditional knowledge especially in environmental afairs. It can be concluded that a strengthened position of traditional knowledge in regulation and law should be supplemented by social measures and actions to overcome bureaucratic, geographical, and communicative barriers. Derived recommendations imply that the perspective of the Bedouin community should be taken into account

Engaging local communities in restoration projects:reconsidering the role of traditional knowledge in Wadi Allaqi, Egypt

Although there may be large differences between scientific and traditional knowledge (TK) traditions, the possible role of TK for natural management and ecological restoration is increasingly recognized and implies the engagement of local people in conservation and restoration projects. This article explores several forms of community engagement: public participation, citizen science, and responsible research and innovation and argues for an integrated approach as they cover different aspects with regard to the engagement of local people in the context of TK. We illustrate our approach with examples from Wadi Allaqi, a remote area in Southern Egypt. It is concluded that both scientists and local people could profit from such an interaction in ecological restoration and conservation, but that effective policy and management strategies are needed to improve and develop mutually fruitful relationships between scientists and local people

SCN-AVP release of mPer1/mPer2 double-mutant mice in vitro

Background: Circadian organisation of behavioural and physiological rhythms in mammals is largely driven by the clock in the suprachiasmatic nuclei (SCN) of the hypothalamus. In this clock, a molecular transcriptional repression and activation mechanism generates near 24 hour rhythms. One of the outputs of the molecular clock in specific SCN neurons is arginine-vasopressin (AVP), which is responsive to transcriptional activation by clock gene products. As negative regulators, the protein products of the period genes are thought to repress transcriptional activity of the positive limb after heterodimerisation with CRYPTOCHROME. When both the Per1 and Per2 genes are dysfunctional by targeted deletion of the PAS heterodimer binding domain, mice lose circadian organization of behaviour upon release into constant environmental conditions. To which degree the period genes are involved in the control of AVP output is unknown. Methods: Using an in vitro slice culture setup, SCN-AVP release of cultures made of 10 wildtype and 9 Per1/2 double-mutant mice was assayed. Mice were sacrificed in either the early light phase of the light-dark cycle, or in the early subjective day on the first day of constant dark. Results: Here we report that in arrhythmic homozygous Per1/2 double-mutant mice there is still a diurnal peak in in vitro AVP release from the SCN similar to that of wildtypes but distinctively different from the release pattern from the paraventricular nucleus. Such a modulation of AVP release is unexpected in mice where the circadian clockwork is thought to be disrupted. Conclusion: Our results suggest that the circadian clock in these animals, although deficient in (most) behavioural and molecular rhythms, may still be (partially) functional, possibly as an hourglass mechanism. The level of perturbation of the clock in Per1/2 double mutants may therefore be less than was originally thought.

Circadian Pacemaker – Temperature Compensation

One of the defining characteristics of circadian pacemakers and indicates the independence of the speed of circadian clock processes of environmental temperature. Mechanisms involved, so far not elucidated in full detail, entail at least two processes that are similarly affected by temperature changes, but with an opposing and counterbalancing effect on the periodicity of the clock system. As a result of temperature compensation, the increase in reaction velocity for every 10° rise in temperature (Q10) of processes governed by circadian pacemakers reaches values of about 1.