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Till Roenneberg
Till Roenneberg (born 4 May 1953) is a professor of chronobiology at the Institute of Medical Psychology at Ludwig Maximilian University of Munich, Ludwig-Maximilian University (LMU) in Munich, Germany. Roenneberg, in collaboration with Martha Merrow, explores the impact of light on human circadian rhythms, focusing on aspects such as chronotypes and social jet lag in relation to health benefits. Life Roenneberg was born in Munich, Germany. He began working with Jürgen Aschoff at the age of 17. Roenneberg attended both the University College London and Ludwig Maximilian University of Munich where he began by studying physics. He switched to medicine in order to focus on the science of the human body, but ended up studying biology. As a postdoctoral fellow, he studied again under Jürgen Aschoff, studying annual rhythms in the body, then moved to the United States to study the cellular basis of biological clocks under Woody Hastings at Harvard University. In 1991, he began ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Munich, Germany
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the third-largest city in Germany, after Berlin and Hamburg, and thus the largest which does not constitute its own state, as well as the 11th-largest city in the European Union. The city's metropolitan region is home to 6 million people. Straddling the banks of the River Isar (a tributary of the Danube) north of the Bavarian Alps, Munich is the seat of the Bavarian administrative region of Upper Bavaria, while being the most densely populated municipality in Germany (4,500 people per km2). Munich is the second-largest city in the Bavarian dialect area, after the Austrian capital of Vienna. The city was first mentioned in 1158. Catholic Munich strongly resisted the Reformation and was a political point of divergence during the resulting Thirty Years' War, but remained physically un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woody Hastings
John Woodland "Woody" Hastings, (March 24, 1927 – August 6, 2014) was a leader in the field of photobiology, especially bioluminescence, and was one of the founders of the field of circadian biology (the study of circadian rhythms, or the sleep-wake cycle). He was the Paul C. Mangelsdorf Professor of Natural Sciences and Professor of Molecular and Cellular Biology at Harvard University. He published over 400 papers and co-edited three books. Hastings research on bioluminescence principally focused on bacterial luminescence (over 150 papers) and dinoflagellates (over 80 papers). In addition to bacteria and dinoflagellates, he, with his students and colleagues, also published papers on the biochemical and molecular mechanisms of light production in fungi, cnidarians, ctenophores, polychaetes, insects (fireflies and dipterans), ostracod crustaceans, millipedes, tunicates, and fishes with bacterial light organs. His laboratory produced the first evidence for quorum sensing in bacter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obesity
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's weight divided by the square of the person's height—is over ; the range is defined as overweight. Some East Asian countries use lower values to calculate obesity. Obesity is a major cause of disability and is correlated with various diseases and conditions, particularly cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Obesity has individual, socioeconomic, and environmental causes. Some known causes are diet, physical activity, automation, urbanization, genetic susceptibility, medications, mental disorders, economic policies, endocrine disorders, and exposure to endocrine-disrupting chemicals. While a majority of obese individuals at any given time are attempting to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midpoint
In geometry, the midpoint is the middle point of a line segment. It is equidistant from both endpoints, and it is the centroid both of the segment and of the endpoints. It bisects the segment. Formula The midpoint of a segment in ''n''-dimensional space whose endpoints are A = (a_1, a_2, \dots , a_n) and B = (b_1, b_2, \dots , b_n) is given by :\frac. That is, the ''i''th coordinate of the midpoint (''i'' = 1, 2, ..., ''n'') is :\frac 2. Construction Given two points of interest, finding the midpoint of the line segment they determine can be accomplished by a compass and straightedge construction. The midpoint of a line segment, embedded in a plane, can be located by first constructing a lens using circular arcs of equal (and large enough) radii centered at the two endpoints, then connecting the cusps of the lens (the two points where the arcs intersect). The point where the line connecting the cusps intersects the segment is then the midpoint of the segment. It is more ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep Debt
Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental or physical fatigue, and can adversely affect one's mood, energy and ability to think clearly. There are two kinds of sleep debt: result of partial sleep deprivation, and of total sleep deprivation. Partial sleep deprivation occurs when a person or a lab animal sleeps too little for several days or weeks. Total sleep deprivation, on the other hand, occurs when the subject is being kept awake for at least 24 hours. There is debate in the scientific community over the specifics of sleep debt (see ), and it is not considered to be a disorder. Physiological effects of sleep debt Chronic sleep debt has a substantial health impact on the human body, specifically on metabolic and endocrine functions. A study published in ''The Lancet'' investigated the physiological effects of sleep debt by assessing the sympathovagal balance (an indicator of the sympathetic nerv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Angle Of Entrainment
Phase or phases may refer to: Science *State of matter, or phase, one of the distinct forms in which matter can exist *Phase (matter), a region of space throughout which all physical properties are essentially uniform *Phase space, a mathematical space in which each possible state of a physical system is represented by a point — this equilibrium point is also referred to as a "microscopic state" **Phase space formulation, a formulation of quantum mechanics in phase space *Phase (waves), the position of a point in time (an instant) on a waveform cycle **Instantaneous phase, generalization for both cyclic and non-cyclic phenomena * AC phase, the phase offset between alternating current electric power in multiple conducting wires **Single-phase electric power, distribution of AC electric power in a system where the voltages of the supply vary in unison **Three-phase electric power, a common method of AC electric power generation, transmission, and distribution *Phase problem, the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Munich Chronotype Questionnaire
The Munich Chronotype Questionnaire (MCTQ) was created in 1976 by Till Roenneberg and Martha Merrow at Ludwig-Maximilians University (LMU) Munich. The MCTQ samples sleep and circadian rhythm data from more than 25,000 participants. Questions about work day and free day sleep schedules, work details, and lifestyle provide data to aid in the understanding of how biological clocks work in social life, such as Roenneberg's conclusions of social jetlag. The MCTQ categorizes each participant into one of seven chronotype groups, and utilizes data on participants’ midsleep phase and sleep debt Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental or physical fatigue, and can adversely affect one's mood, energy and ability to think clearly. There are two kinds of sleep ... to survey what "type" of sleeper each person is. From these data, the MCTQ offers methods to make up for sleep debt (if any), and offers suggestio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeitgeber
A zeitgeber () is any external or environmental cue that entrains or synchronizes an organism's biological rhythms, usually naturally occurring and serving to entrain to the Earth's 24-hour light/dark and 12-month cycles. History The term ' (; ) was first used by Jürgen Aschoff, one of the founders of the field of chronobiology. His work demonstrated the existence of endogenous (internal) biological clocks, which synchronize biological rhythms. In addition, he found that certain exogenous (external) cues, which he called zeitgeber, influence the timing of these internal clocks. Photic and nonphotic zeitgebers * Light (light is a more important zeitgeber than social interactions). * Atmospheric conditions * Medication * Temperature * Social interactions * Exercise * Eating/drinking patterns Circadian rhythms Any biological process in the body that repeats itself over a period of approximately 24 hours and maintains this rhythm in the absence of external stimuli is considered a ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the way they are generated through the cellular process of mitosis. The two new haploid cells are genetically identical to the haploid parent, and can develop into new organisms if conditions are favorable, and serve in biological dispersal. Asexual reproduction in ascomycetes (the phylum Ascomycota) is by the formation of conidia, which are borne on specialized stalks called conidiophores. The morphology of these specialized conidiophores is often distinctive between species and, before the development of molecular techniques at the end of the 20th century, was widely used for identification of (''e.g.'' ''Metarhizium'') species. The terms microconidia and macroconidia are sometimes used. Conidiogenesis There are two main types of conidium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency (gene)
The frequency (''frq'') gene encodes the protein frequency (FRQ) that functions in the ''Neurospora crassa'' circadian clock. The FRQ protein plays a key role in circadian oscillator, serving to nucleate the negative element complex in the auto regulatory transcription-translation negative feedback-loop (TTFL) that is responsible for circadian rhythms in ''N. crassa''. Similar rhythms are found in mammals, ''Drosophila'' and cyanobacteria. Recently, FRQ homologs have been identified in several other species of fungi. Expression of frq is controlled by the two transcription factors white collar-1 (WC-1) and white collar-2 (WC-2) that act together as the White Collar Complex (WCC) and serve as the positive element in the TTFL. Expression of frq can also be induced through light exposure in a WCC dependent manner. Forward genetics has generated many alleles of ''frq'' resulting in strains whose circadian clocks vary in period length. Discovery The ''frq'' locus was discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entrainment (chronobiology)
In the study of chronobiology, entrainment occurs when rhythmic physiological or behavioral events match their period to that of an environmental oscillation. It is ultimately the interaction between circadian rhythms and the environment. A central example is the entrainment of circadian rhythms to the daily light–dark cycle, which ultimately is determined by the Earth's rotation. Exposure to certain environmental stimuli will cue a phase shift, and abrupt change in the timing of the rhythm. Entrainment helps organisms maintain an adaptive phase relationship with the environment as well as prevent drifting of a free running rhythm. This stable phase relationship achieved is thought to be the main function of entrainment. There are two general modes of entrainment: phasic and continuous. The phasic mode is when there is limited interaction with the environment to "reset" the clock every day by the amount equal to the "error", which is the difference between the environmental cycle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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