scholarly journals Evolution in caves: selection from darkness causes spinal deformities in teleost fishes

2018 ◽  
Vol 14 (6) ◽  
pp. 20180197 ◽  
Author(s):  
Julián Torres-Dowdall ◽  
Nidal Karagic ◽  
Martin Plath ◽  
Rüdiger Riesch
Keyword(s):  
Spinal Column ◽  
Spinal Deformities ◽  
Teleost Fishes ◽  
Dark Cycle ◽  
Trait Divergence ◽  
Relative Paucity ◽  
Poecilia Mexicana ◽  
Amphilophus Citrinellus ◽  
Normal Light ◽  
Successful Colonization

Only few fish species have successfully colonized subterranean habitats, but the underlying biological constraints associated with this are still poorly understood. Here, we investigated the influence of permanent darkness on spinal-column development in one species (Midas cichlid, Amphilophus citrinellus ) with no known cave form, and one (Atlantic molly, Poecilia mexicana ) with two phylogenetically young cave forms. Specifically, fish were reared under a normal light : dark cycle or in permanent darkness (both species). We also surveyed wild-caught cave and surface ecotypes of P. mexicana . In both species, permanent darkness was associated with significantly higher rates of spinal deformities (especially in A. citrinellus ). This suggests strong developmental (intrinsic) constraints on the successful colonization of subterranean environments in teleost fishes and might help explain the relative paucity of cave-adapted lineages. Our results add depth to our understanding of the aspects of selection driving trait divergence and maintaining reproductive isolation in cave faunas.

scholarly journals MODELING OF HUMAN SPINAL COLUMN AND SIMULATION OF SPINAL DEFORMITIES

Mechanika ◽  
2015 ◽  
Vol 21 (3) ◽  
Author(s):  
Corina Mihaela Gruescu ◽  
Alice Garaiman ◽  
Erwin Christian Lovasz
Keyword(s):  
Spinal Column ◽  
Spinal Deformities

The circadian component of spinule dynamics in teleost retinal horizontal cells is dependent on the dopaminergic system

1992 ◽  
Vol 9 (3-4) ◽  
pp. 345-351 ◽  
Author(s):  
H.-J. Wagner ◽  
U. D. Behrens ◽  
M. Zaunreiter ◽  
R. H. Douglas
Keyword(s):  
Dopaminergic System ◽  
Horizontal Cells ◽  
The Other ◽  
Control Fish ◽  
Control Group ◽  
Constant Darkness ◽  
Light Phase ◽  
Dark Cycle ◽  
Normal Light ◽  
Constant Dark

AbstractDuring the light phase of a light/dark cycle, dendrites of teleost cone horizontal cells display numerous finger-like projections, called spinules, which are formed at dawn and degraded at dusk, and are thought to be involved in chromatic feedback processes. We have studied the oscillations of these spinules during a normal light/dark cycle and during 48 h of constant darkness in two groups of strongly rhythmic, diurnal fish, Aequidens pulcher. In one group the retinal dopaminergic system had been destroyed by the application of 6-OHDA, while in the other (control) group, the dopaminergic system was intact. In control fish, oscillations of spinule numbers were observed under both normal and constant dark conditions, indicating the presence of a robust circadian rhythm. However, spinule dynamics were severely affected by the absence of retinal dopamine. During the normal light phase, the number of spinules in 6-OHDA injected retinae was strongly reduced, and throughout continual darkness, spinule formation was almost completely suppressed. These results indicate that dopamine is essential for both light-evoked and circadian spinule formation; furthermore, we conclude that there is no circadian oscillator within horizontal cells controlling the formation of spinules.

scholarly journals The validity of rasterstereography: a systematic review

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Melvin Mohokum ◽  
Samuel Schülein ◽  
Adrian Skwara
Keyword(s):  
Spinal Column ◽  
Cochrane Library ◽  
Spinal Deformities ◽  
Resonance Imaging ◽  
Point Scale ◽  
X Ray ◽  
Non Invasive ◽  
Thoracic Hyperkyphosis ◽  
The Cochrane Library ◽  
Scoliosis Progression

o investigate and monitor the progression of scoliosis and other spinal deformities in patients following idiopathic scoliosis (IS), non-invasive and radiation-free techniques are recommended because of the need for repeated radiographs. In a clinical setting, spine parameters can be quickly, cheaply and easily assessed using rasterstereography (RS). To assess the validity of the radiation-free technique RS based on surface topography compared with radiographs. MEDLINE, the Cochrane Library and EMBASE were systematically searched for studies which investigate the validity of rasterstereography compared with x-ray measurements. Studies published between January 1, 1990 and July 31, 2013 in English, German and French were included. Studies dealing with magnetic resonance imaging were excluded. Twelve studies with 570 patients were included; these articles were published between 1990 and 2013. The majority of studies investigated patients with IS, but other spinal pathologies included were thoracic hyperkyphosis and Scheuermann’s disease. With regard to the quality assessment criteria for the included studies, three out of twelve studies were evaluated using a twelve point scale and two used a scale with eleven points. We conclude that RS facilitates clinical practice by analysing the spinal column. It is completely radiation-free and could help to monitor scoliosis progression.

scholarly journals Impact of Time-Restricted Feeding to Late Night on Adaptation to a 6 h Phase Advance of the Light-Dark Cycle in Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Baoyin Ren ◽  
Changxiao Ma ◽  
Lihong Chen ◽  
Garret A. FitzGerald ◽  
Guangrui Yang
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Modern Society ◽  
Circadian Disruption ◽  
Environmental Cues ◽  
Jet Lag ◽  
Restricted Feeding ◽  
Dark Cycle ◽  
Late Night ◽  
Normal Light

In modern society, more and more people suffer from circadian disruption, which in turn affects health. But until now, there are no widely accepted therapies for circadian disorders. Rhythmic feeding behavior is one of the most potent non-photic zeitgebers, thus it has been suggested that it was important to eat during specific periods of time (time-restricted feeding, TRF) so that feeding is aligned with environmental cues under normal light/dark conditions. Here, we challenged mice with a 6 h advanced shift, combined with various approaches to TRF, and found that food restricted to the second half of the nights after the shift facilitated adaptation. This coincided with improved resilience to sepsis. These results raise the possibility of reducing the adverse responses to jet lag by subsequent timing of food intake.

scholarly journals Light represses transcription of asparagine synthetase genes in photosynthetic and nonphotosynthetic organs of plants.

1991 ◽  
Vol 11 (10) ◽  
pp. 4966-4972 ◽  
Author(s):  
F Y Tsai ◽  
G Coruzzi
Keyword(s):  
Gene Expression ◽  
Direct Effect ◽  
Transcriptional Repression ◽  
Time Course ◽  
Nicotiana Plumbaginifolia ◽  
Asparagine Synthetase ◽  
General Phenomenon ◽  
Dark Cycle ◽  
Normal Light ◽  
Effect Of Light

Asparagine synthetase (AS) mRNA in Pisum sativum accumulates preferentially in plants grown in the dark. Nuclear run-on experiments demonstrate that expression of both the AS1 and AS2 genes is negatively regulated by light at the level of transcription. A decrease in the transcriptional rate of the AS1 gene can be detected as early as 20 min after exposure to light. Time course experiments reveal that the levels of AS mRNA fluctuate dramatically during a "normal" light/dark cycle. This is due to a direct effect of light and not to changes associated with circadian rhythm. A novel finding is that the light-repressed expression of the AS1 gene is as dramatic in nonphotosynthetic organs such as roots as it is in leaves. Experiments demonstrate that the small amount of light which passes through the soil is sufficient to repress AS1 expression in roots, indicating that light has a direct effect on AS1 gene expression in roots. The negative regulation of AS gene expression by light was shown to be a general phenomenon in plants which also occurs in nonlegumes such as Nicotiana plumbaginifolia and Nicotiana tabacum. Thus, the AS genes can serve as a model with which to dissect the molecular basis for light-regulated transcriptional repression in plants.

Light-induced retinal degeneration in rdgB (retinal degeneration B) mutant of Drosophila: Electrophysiological and morphological manifestations of degeneration

1989 ◽  
Vol 2 (6) ◽  
pp. 529-539 ◽  
Author(s):  
Chaim T. Rubinstein ◽  
Shoshana Bar-Nachum ◽  
Zvi Selinger ◽  
Baruch Minke
Keyword(s):  
Retinal Degeneration ◽  
Early Stage ◽  
Light And Electron Microscopy ◽  
Bright Light ◽  
Light Response ◽  
Photoreceptor Cells ◽  
Dark Cycle ◽  
Voltage Dependent ◽  
Normal Light ◽  
Two Phases

AbstractQuantitative light and electron microscopy was used to monitor the extent of retinal degeneration as a function of age and temperature in the white-eyed rdgBKS222 mutant of Drosophila melanogaster. Parallel measurements of the electroretinogram (ERG) of the degenerating retina reveal a new phenomenon – the appearance of spike potentials following illumination with bright light. These spikes, which do not appear in the normal fly retina, have a relatively long duration (20–50 ms), regenerative properties, and a rate of occurrence which increases with increasing light intensity. The spikes differed from the light response in being more susceptible to CO2 and to cuts in the eye. The spikes completely disappeared at low extracellular Ca2+ levels which did not reduce the amplitude of the light response. The spike potentials become triphasic when the recording electrode is advanced to the level of the basement membrane. This suggests that the spike potentials originate from the photoreceptor axons as a result of synchronous opening of voltage-dependent channels in a large number of photoreceptor cells. The occurrence of spike potentials during the process of degeneration was studied. Two phases can be distinguished: (1) Spike potentials appear in retinae of 2–3-day-old flies which display few morphological signs of degeneration. The frequency of appearance of spike potentials decreases in retinae of 14–16-day-old flies which show extensive degeneration of the R1–6 photoreceptor cells but no degeneration of the central R7,8 cells. (2) Spike potentials appear more frequently again in flies of 22–24 d of age. This is probably a consequence of degeneration of the remaining R7,8 photoreceptor cells. Temperature and the light-dark cycle had a critical effect on degeneration. Eight-day-old mutants raised at 19°C in a normal light-dark cycle showed only little degeneration. Eight-day-old mutants raised at 24°C showed only a slight degeneration when raised in the dark. However, the degree of degeneration was greatly enhanced in the mutants raised at 24°C under a light-dark cycle regime.The combined electrophysiological and morphological study of the degeneration, as a function of age and temperature, revealed that (1) the degeneration process takes place even in darkness, but at a slow rate, while light greatly accelerates the degeneration. (2) The degeneration is negligible at 19°C, even during light, in the first week after eclosion. (3) The appearance of spike potentials at an early stage of the degeneration suggests that changes in the plasma membrane of the photoreceptor cells manifest at an initial stage of the degeneration process.

scholarly journals Computer Pattern Recognition: Spontaneous Motor Activity Studies of Rats Following Acute Exposure to Triethyltin

1991 ◽  
Vol 10 (6) ◽  
pp. 705-718 ◽  
Author(s):  
W. J. Kernan ◽  
D. L. Hopper ◽  
M. P. Bowes
Keyword(s):  
Pattern Recognition ◽  
Red Light ◽  
Recognition System ◽  
Exposed Group ◽  
Light Cycle ◽  
Light Conditions ◽  
Sprague Dawley ◽  
Dark Cycle ◽  
Sprague Dawley Rats ◽  
Normal Light

A computer pattern recognition system, RAPID, was used to measure the spontaneous activity of male Sprague-Dawley rats during six observational periods distributed over 11 days after a single oral dose of triethyltin bromide (TET) at 3 or 5 mg/kg. These observational periods were distributed between those taken under red light conditions during the animals normal dark cycle (Days 2, 7, and 10 after exposure) and those taken under white light conditions during the animals normal light cycle (Days 3, 6, and 11 after exposure). Significant disruption of the normal behavioral patterns were observed on Days 2 and 7 for the 3 mg/kg-exposed group and on Days 2, 3, 6, 7, and 10 for the 5 mg/kg-exposed group.

Light represses transcription of asparagine synthetase genes in photosynthetic and nonphotosynthetic organs of plants

1991 ◽  
Vol 11 (10) ◽  
pp. 4966-4972
Author(s):  
F Y Tsai ◽  
G Coruzzi
Keyword(s):  
Gene Expression ◽  
Direct Effect ◽  
Transcriptional Repression ◽  
Time Course ◽  
Nicotiana Plumbaginifolia ◽  
Asparagine Synthetase ◽  
General Phenomenon ◽  
Dark Cycle ◽  
Normal Light ◽  
Effect Of Light

Asparagine synthetase (AS) mRNA in Pisum sativum accumulates preferentially in plants grown in the dark. Nuclear run-on experiments demonstrate that expression of both the AS1 and AS2 genes is negatively regulated by light at the level of transcription. A decrease in the transcriptional rate of the AS1 gene can be detected as early as 20 min after exposure to light. Time course experiments reveal that the levels of AS mRNA fluctuate dramatically during a "normal" light/dark cycle. This is due to a direct effect of light and not to changes associated with circadian rhythm. A novel finding is that the light-repressed expression of the AS1 gene is as dramatic in nonphotosynthetic organs such as roots as it is in leaves. Experiments demonstrate that the small amount of light which passes through the soil is sufficient to repress AS1 expression in roots, indicating that light has a direct effect on AS1 gene expression in roots. The negative regulation of AS gene expression by light was shown to be a general phenomenon in plants which also occurs in nonlegumes such as Nicotiana plumbaginifolia and Nicotiana tabacum. Thus, the AS genes can serve as a model with which to dissect the molecular basis for light-regulated transcriptional repression in plants.

scholarly journals Orthopedic and surgical correction of paralytic deformities of the spine in children and adolescents

2021 ◽  
Author(s):  
И.А. Шавырин ◽  
Е.А. Букреева ◽  
Т.А. Седненкова ◽  
С.В. Колесов ◽  
Д.В. Ковалёв
Keyword(s):  
Surgical Treatment ◽  
Children And Adolescents ◽  
Surgical Techniques ◽  
Spinal Column ◽  
Surgical Correction ◽  
Spinal Deformities ◽  
Successful Development ◽  
Medical Technologies ◽  
New Knowledge ◽  
New Instruments

Благодаря успешному развитию современных медицинских технологий, появлению новых знаний, нового инструментария и имплантатов, совершенствованию хирургических методик, анестезиологической поддержки, появилась возможность проведения оперативной коррекции деформаций позвоночника группе пациентов, страдающих нейромышечным сколиозом, с меньшим интраоперационным риском, более быстрым восстановлением и меньшим числом осложнений. Ортопедохирургическое лечение паралитических деформаций позвоночника проводится при использовании дорсальных и вентральных методик путем коррекции и полисегментарной фиксации позвоночного столба. В результате проведенных вмешательств у данной группы больных улучшается баланс туловища, предотвращается прогрессирование деформации позвоночника и грудной клетки, улучшается самообслуживание пациентов. Thanks to the successful development of modern medical technologies, the emergence of new knowledge, new instruments and implants, the improvement of surgical techniques, anesthetic support, it became possible to perform surgical correction of spinal deformities in a group of patients suffering from neuromuscular scoliosis, with a lower intraoperative risk, faster recovery and fewer complications. Orthopedic and surgical treatment of paralytic deformities of the spine is carried out using dorsal and ventral techniques by means of correction and polysegmental fixation of the spinal column. As a result of the interventions in this group of patients, the balance of the trunk is improved, the progression of deformity of the spine and chest is prevented, and self-care of patients is improved.

Diurnal variation of thermal resistance in rats

1980 ◽  
Vol 58 (10) ◽  
pp. 1174-1179 ◽  
Author(s):  
Y. Isobe ◽  
S. Takaba ◽  
K. Ohara
Keyword(s):  
Body Temperature ◽  
Heat Resistance ◽  
Time Of Day ◽  
Dark Phase ◽  
Diurnal Changes ◽  
Survival Times ◽  
Light Phase ◽  
Dark Cycle ◽  
Hot Environment ◽  
Normal Light

Effects of photoperiod on heat resistance were studied in 88 rats by observing their survival times in a hot environment (42.5 °C). Prior to the experiments individual rats were exposed to a given heat (42.5 °C) at a definite time of day and a "predicted survial time" in a given heat in individual rats was obtained. Rats were then divided into eight groups (with nine rats in each group) so as to ensure intergroup homogeneity regarding their predicted survival time and were exposed to heat at different times of day (every 3 h) until they were exhausted.It was found that the heat resistance varied with the time of day. In the eight groups kept under a normal light–dark cycle (L, 0700–1900; D, 1900–0700), heat resistances were observed to be significantly higher in the light phase than in the dark phase. Lethal body temperature was not correlated with the heat resistance. In two other groups (n = 8) kept under conditions reversed from the normal lighting cycle, resistance was higher in the nighttime (corresponding to the light phase when the rats were kept in the reversed lighting cycle) than in the morning (corresponding to the dark phase), these changes being accompanied by a phase shift of the diurnal changes in body temperature.

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