Light and Clocks in Dark Places

The sun is the premise of our existence. Most animals and all plants use the predictability of the sunrise and sunset to drive a lot of their biological processes, which in turn gives these organisms a fitness advantage. However, there are a subset of animals that live in dark environments, hidden away from the light, yet we know very little about how these animals organise the biology that is normally light or clock driven in other animals. In this thesis, I explore how light impacts the biology of three very different species of fish and explore some aspects of how adaptation to a dark environment many have occurred. 1. The zebrafish, a well-developed model system that uses and depends heavily on sunlight for its survival. In this first data chapter I address how different wavelengths of light impact clock and light inducible genes in different ways. Furthermore, I present data that supports the hypothesis that the different organs of fish have different wavelength sensitivities. 2. I then move on to a relatively “recent” dark adapted animal, the Mexican blind cavefish, a species of fish that has been isolated in over 30 subterranean caves some million years ago, and show extreme adaptations to the dark, such as loss of pigment and eyes. In this second data chapter I show how all strains of cavefish show a delay in the onset of its clock in development, and how different cave populations show slightly different expression patterns in response to light/dark cycles, hinting at different evolutionary adaptations. 3. Finally, I dive deep, into the deep-sea, an environment that shows a strange duality of being pitch black but with animals that possess some of the most impressive visual systems on earth. In this last chapter I present work on two species of deep-sea hatchetfish that have evolved over the past 200 million years in the deep-sea. In this final chapter I present the first molecular study on light and circadian rhythms in deep-sea vertebrates. I explore how two species of hatchetfish, one rhythmic and one arrhythmic, have adapted to a light in the open ocean, and find surprising evidence of in vitro light-sensitivity

Zebrafish circadian clock entrainment and the importance of broad spectral light sensitivity

One of the key defining features of an endogenous circadian clock is that it can be entrained or set to local time. Though a number of cues can perform this role, light is the predominant environmental signal that acts to entrain circadian pacemakers in most species. For the past 20 years, a great deal of work has been performed on the light input pathway in mammals and the role of intrinsically photosensitive retinal ganglion cells (ipRGCs)/melanopsin in detecting and sending light information to the suprachiasmatic nucleus (SCN). In teleost fishes, reptiles and birds, the biology of light sensitivity is more complicated as cells and tissues can be directly light responsive. Non-visual light signalling was described many years ago in the context of seasonal, photoperiodic responses in birds and lizards. In the case of teleosts, in particular the zebrafish model system, not only do peripheral tissues have a circadian pacemaker, but possess clear, direct light sensitivity. A surprisingly wide number of opsin photopigments have been described within these tissues, which may underpin this fundamental ability to respond to light, though no specific functional link for any given opsin yet exists. In this study, we show that zebrafish cells show wide spectral sensitivities, as well as express a number of opsin photopigments - several of which are under direct clock control. Furthermore, we also show that light outside the visual range, both ultraviolet and infrared light, can induce clock genes in zebrafish cells. These same wavelengths can phase shift the clock, except infrared light, which generates no shift even though genes such asper2andcry1aare induced

Blind fish have cells that see light

Most animals on earth have evolved under daily light-dark cycles and consequently possess a circadian clock which regulates much of their biology, from cellular processes to behaviour. There are however some animals that have invaded dark ecosystems and have adapted to an apparently arrhythmic environment. One such example is the Mexican blind cavefish Astyanax mexicanus, a species complex with over 30 different isolated cave types, including the founding surface river fish. These cavefish have evolved numerous fascinating adaptations to the dark, such as loss of eyes, reduced sleep phenotype and alterations in their clock and light biology. While cavefish are an excellent model for studying circadian adaptations to the dark, their rarity and long generational time makes many studies challenging. To overcome these limitations, we established embryonic cell cultures from cavefish strains and assessed their potential as tools for circadian and light experiments. Here, we show that despite originating from animals with no eyes, cavefish cells in culture are directly light responsive and show an endogenous circadian rhythm, albeit that light sensitivity is relatively reduced in cave strain cells. Expression patterns are similar to adult fish, making these cavefish cell lines a useful tool for further circadian and molecular studies

From Arctic Science to International Law: The Road towards the Minamata Convention and the Role of the Arctic Council

The Minamata Convention, which entered into force on 16 August 2017, is a global, legally binding instrument on mercury. The initiative on the Minamata Convention was mainly driven by research showing negative effects on human health and the environment in the Arctic. The Arctic Council, an intergovernmental forum promoting cooperation on Arctic issues, and its Working Group, AMAP, played an important role in the process leading up to international negotiations on the Minamata Convention. This paper elucidates the evolutionary process in which scientific knowledge, herded by an intergovernmental, regional forum, is involved and forms the basis for a legally binding agreement. The paper provides new insight on multilevel governance of the mercury issue and unravels the role that AMAP has played in this dynamic process.publishedVersio

Hva opplever sykepleierstudenter som hensiktsmessig bruk av studentresponssystem i undervisning i palliativ omsorg?

Studentresponssystem (SRS) har vært brukt over lengre tid i flere utdanninger, men har forholdsvis nylig blitt tatt i bruk innen sykepleierutdanningen. Å ta i bruk SRS i større klasser er en tilnærming for å aktivisere og engasjere studenter under forelesning. Hensikten med studien var å beskrive hva sykepleierstudenter opplever som hensiktsmessig bruk av SRS med tanke på deres læring. Data ble samlet fra ett fokusgruppeintervju med fire andreårs sykepleierstudenter som gjennomførte kurs i palliativ omsorg i 2013. Tre temaer ble identifisert; valg av pedagogisk metode som fremmer læring, tilbakemelding til og fra lærer, og gjennomføring av avstemning. Funnene tyder på at hensiktsmessig bruk av SRS forutsetter engasjerte lærere som kombinerer SRS med pedagogiske metoder som tilrettelegger for refleksjon og interaksjon mellom studentene, og mellom studenter og lærer

Intensive care nurses’ experiences using volatile anaesthetics in the intensive care unit: An exploratory study

Objective: To explore the experiences intensive care nurses have with volatile anaesthetics in the intensive care unit. Research methodology and design: A qualitative exploratory and descriptive design was used. Data were collected in 2019 from individual interviews with nine intensive care nurses, who were recruited using purposive sampling. Data were analysed using systematic text condensation. Setting: The study was undertaken in two general intensive care units from different university hospitals in Norway where volatile anaesthetics were utilised. Findings: Three categories emerged from the data analysis: experiencing the benefits of volatile anaesthetics; coping with unfamiliarity in handling volatile anaesthetics; and meeting challenges related to volatile anaesthetics in practice. Conclusion: The intensive care nurses had positive experiences related to administering volatile anaesthetics in the intensive care unit and responded positively to the prospect of using it more often. Because volatile anaesthetics were rarely used in their units, the participants felt uncertain regarding its use due to unfamiliarity. Collegial support and guidelines were perceived as pivotal in helping them cope with this uncertainty. The participants also experienced several challenges in using volatile anaesthetics in the intensive care unit, with ambient pollution being regarded as the main challenge.acceptedVersio

Development of the Astyanax mexicanus circadian clock and non-visual light responses

Most animals and plants live on the planet exposed to periods of rhythmic light and dark. As such, they have evolved endogenous circadian clocks to regulate their physiology rhythmically, and non-visual light detection mechanisms to set the clock to the environmental light-dark cycle. In the case of fish, circadian pacemakers are not only present in the majority of tissues and cells, but these tissues are themselves directly light-sensitive, expressing a wide range of opsin photopigments. This broad non-visual light sensitivity exists to set the clock, but also impacts a wide range of fundamental cell biological processes, such as DNA repair regulation. In this context, Astyanax mexicanus is a very intriguing model system with which to explore non-visual light detection and circadian clock function. Previous work has shown that surface fish possess the same directly light entrainable circadian clocks, described above. The same is true for cave strains of Astyanax in the laboratory, though no daily rhythms have been observed under natural dark conditions in Mexico. There are, however, clear alterations in the cave strain light response and changes to the circadian clock, with a difference in phase of peak gene expression and a reduction in amplitude. In this study, we expand these early observations by exploring the development of non-visual light sensitivity and clock function between surface and cave populations. When does the circadian pacemaker begin to oscillate during development, and are there differences between the various strains? Is the difference in acute light sensitivity, seen in adults, apparent from the earliest stages of development? Our results show that both cave and surface populations must experience daily light exposure to establish a larval gene expression rhythm. These oscillations begin early, around the third day of development in all strains, but gene expression rhythms show a significantly higher amplitude in surface fish larvae. In addition, the light induction of clock genes is developmentally delayed in cave populations. Zebrafish embryonic light sensitivity has been shown to be critical not only for clock entrainment, but also for transcriptional activation of DNA repair processes. Similar downstream transcriptional responses to light also occur in Astyanax. Interestingly, the establishment of the adult timing profile of clock gene expression takes several days to become apparent. This fact may provide mechanistic insight into the key differences between the cave and surface fish clock mechanisms

Circadian Clocks in Fish-What Have We Learned so far?

Zebrafish represent the one alternative vertebrate, genetic model system to mice that can be easily manipulated in a laboratory setting. With the teleost Medaka (Oryzias latipes), which now has a significant following, and over 30,000 other fish species worldwide, there is great potential to study the biology of environmental adaptation using teleosts. Zebrafish are primarily used for research on developmental biology, for obvious reasons. However, fish in general have also contributed to our understanding of circadian clock biology in the broadest sense. In this review, we will discuss selected areas where this contribution seems most unique. This will include a discussion of the issue of central versus peripheral clocks, in which zebrafish played an early role; the global nature of light sensitivity; and the critical role played by light in regulating cell biology. In addition, we also discuss the importance of the clock in controlling the timing of fundamental aspects of cell biology, such as the temporal control of the cell cycle. Many of these findings are applicable to the majority of vertebrate species. However, some reflect the unique manner in which "fish" can solve biological problems, in an evolutionary context. Genome duplication events simply mean that many fish species have more gene copies to "throw at a problem", and evolution seems to have taken advantage of this "gene abundance". How this relates to their poor cousins, the mammals, remains to be seen

Haematological nurses' experiences about palliative care trajectories of patients with life-threatening haematological malignancies: A qualitative study

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Aims: To explore haematological nurses' experiences about the palliative care trajectories of patients with life-threatening haematological malignancies. Design: A qualitative study with a descriptive and explorative design. Methods: Data were collected through 12 individual semi-structured interviews of nurses who work with patients with haematological malignancies from four hospitals in Norway. The data were analysed using systematic text condensation. The study was reported according to the Consolidated Criteria for Reporting Qualitative Research checklist. Results: Three categories emerged from the data analysis: focus on a cure delays integration of palliative care, dialogue with patients facilitates palliative care and the need for enhanced interdisciplinary understanding. Patient or public contribution: No patient or public contribution since nurses' experiences were explored.publishedVersio

The Distinct Cases of Kosovo and South Ossetia: Deciding the Question of Independence on the Merits and International Law

The cases of Kosovo and South Ossetia provide two opportunities for the community of nations to reconcile the rights of Serbia and Georgia with the rights of the peoples within their borders. Instead of doing so, other countries used these cases for ideological and political posturing and continued to do so as of the end of 2008. This Note will review Kosovo and South Ossetia and attempt to take the politics out of an inherently political decision-whether or not to recognize them as independent states. Part I of this Note will review how the United Nations has approached the issues of autonomy, borders, secession, and minorities. It will also provide background on the doctrines of self-determination and the rights of states. Part II will set out the facts-as they are generally accepted-of Kosovo and South Ossetia and consider the differing opinions regarding independence of the two areas. Part III will review those opinions in light of the goals and doctrines of the United Nations and how it has approached these issues in the past. The Note concludes that recognition of independence of the states should be driven by legal arguments rather than political or social alliances and that the goals of the United Nations are best served by being steadfast in promoting multi-ethnicity within political entities; Kosovo and South Ossetia should be recognized as autonomous regions within Serbia and Georgia, respectively. The Note also concludes that domestic as well as international legal structures must be in place to make autonomy workable