scholarly journals Health risks associated with genetic alterations in internal clock system by external factors

2018 ◽  
Vol 14 (7) ◽  
pp. 791-798 ◽  
Author(s):  
Suliman Khan ◽  
Ghulam Nabi ◽  
Lunguang Yao ◽  
Rabeea Siddique ◽  
Wasim Sajjad ◽  
...  
2016 ◽  
Vol 74 (4) ◽  
pp. 299-302 ◽  
Author(s):  
Vanessa Fernanda Moreira Ferreira ◽  
Gabriel Pina Paiva ◽  
Natália Prando ◽  
Carla Renata Graça ◽  
João Aris Kouyoumdjian

ABSTRACT Our internal clock system is predominantly dopaminergic, but memory is predominantly cholinergic. Here, we examined the common sensibility encapsulated in the statement: “time goes faster as we get older”. Objective To measure a 2 min time interval, counted mentally in subjects of different age groups. Method 233 healthy subjects (129 women) were divided into three age groups: G1, 15-29 years; G2, 30-49 years; and G3, 50-89 years. Subjects were asked to close their eyes and mentally count the passing of 120 s. Results The elapsed times were: G1, mean = 114.9 ± 35 s; G2, mean = 96.0 ± 34.3 s; G3, mean = 86.6 ± 34.9 s. The ANOVA-Bonferroni multiple comparison test showed that G3 and G1 results were significantly different (P < 0.001). Conclusion Mental calculations of 120 s were shortened by an average of 24.6% (28.3 s) in individuals over age 50 years compared to individuals under age 30 years.


2021 ◽  
Author(s):  
Gunnar Carlstedt ◽  
Mats Rimborg

<div>A clock system for a huge grid of small clock regions is presented. There is an oscillator in each clock region, which drives the local clock of a processing element (PE). The oscillators are kept synchronized by exploiting the phase of their neighbors. In an infinite mesh, the clock skew would be zero, but in a network of limited size there will be fringe effects. In a mesh with 25×25 oscillators, the maximum skew between neighboring regions is within 3.3 ps. By slightly adjusting the free running frequency of the oscillators, this skew can be reduced to 1.2 ps. The mesh may contain millions of clock regions.</div><div> Because there is no central clock, both power consumption and clock frequency can be improved compared to a conventional clock distribution network. A PE of 150×150 µm² running at 6.7 GHz with 93 master-slave flip-flops is used as an example. The PE-internal clock skew is less than 2.3 ps, and the energy consumption of the clock system 807 µW per PE. It corresponds to an effective gate and wire capacitance of 509 aF, or 7.3 gate capacitances.</div><div> Power noise is reduced by scheduling the local oscillators gradually along one of the grid’s axes. In this way, surge currents, which generally have their peaks at the clock edges, are distributed evenly over a full clock cycle.</div>


2021 ◽  
Author(s):  
Gunnar Carlstedt ◽  
Mats Rimborg

<div>A clock system for a huge grid of small clock regions is presented. There is an oscillator in each clock region, which drives the local clock of a processing element (PE). The oscillators are kept synchronized by exploiting the phase of their neighbors. In an infinite mesh, the clock skew would be zero, but in a network of limited size there will be fringe effects. In a mesh with 25×25 oscillators, the maximum skew between neighboring regions is within 3.3 ps. By slightly adjusting the free running frequency of the oscillators, this skew can be reduced to 1.2 ps. The mesh may contain millions of clock regions.</div><div> Because there is no central clock, both power consumption and clock frequency can be improved compared to a conventional clock distribution network. A PE of 150×150 µm² running at 6.7 GHz with 93 master-slave flip-flops is used as an example. The PE-internal clock skew is less than 2.3 ps, and the energy consumption of the clock system 807 µW per PE. It corresponds to an effective gate and wire capacitance of 509 aF, or 7.3 gate capacitances.</div><div> Power noise is reduced by scheduling the local oscillators gradually along one of the grid’s axes. In this way, surge currents, which generally have their peaks at the clock edges, are distributed evenly over a full clock cycle.</div>


2012 ◽  
Vol 108 (3) ◽  
pp. 381-392 ◽  
Author(s):  
Felino R. Cagampang ◽  
Kimberley D. Bruce

Mammals have an endogenous timing system in the suprachiasmatic nuclei (SCN) of the hypothalamic region of the brain. This internal clock system is composed of an intracellular feedback loop that drives the expression of molecular components and their constitutive protein products to oscillate over a period of about 24 h (hence the term ‘circadian’). These circadian oscillations bring about rhythmic changes in downstream molecular pathways and physiological processes such as those involved in nutrition and metabolism. It is now emerging that the molecular components of the clock system are also found within the cells of peripheral tissues, including the gastrointestinal tract, liver and pancreas. The present review examines their role in regulating nutritional and metabolic processes. In turn, metabolic status and feeding cycles are able to feed back onto the circadian clock in the SCN and in peripheral tissues. This feedback mechanism maintains the integrity and temporal coordination between various components of the circadian clock system. Thus, alterations in environmental cues could disrupt normal clock function, which may have profound effects on the health and well-being of an individual.


Author(s):  
G. W. Hacker ◽  
I. Zehbe ◽  
J. Hainfeld ◽  
A.-H. Graf ◽  
C. Hauser-Kronberger ◽  
...  

In situ hybridization (ISH) with biotin-labeled probes is increasingly used in histology, histopathology and molecular biology, to detect genetic nucleic acid sequences of interest, such as viruses, genetic alterations and peptide-/protein-encoding messenger RNA (mRNA). In situ polymerase chain reaction (PCR) (PCR in situ hybridization = PISH) and the new in situ self-sustained sequence replication-based amplification (3SR) method even allow the detection of single copies of DNA or RNA in cytological and histological material. However, there is a number of considerable problems with the in situ PCR methods available today: False positives due to mis-priming of DNA breakdown products contained in several types of cells causing non-specific incorporation of label in direct methods, and re-diffusion artefacts of amplicons into previously negative cells have been observed. To avoid these problems, super-sensitive ISH procedures can be used, and it is well known that the sensitivity and outcome of these methods partially depend on the detection system used.


2004 ◽  
Vol 3 (1/2) ◽  
pp. 245-269
Author(s):  
Richard L. Harris ◽  
Melinda J. Seid
Keyword(s):  

2012 ◽  
Vol 33 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Joseph Glicksohn ◽  
Yamit Hadad

Individual differences in time production should indicate differences in the rate of functioning of an internal clock, assuming the existence of such a clock. And sex differences in time production should reflect a difference in the rate of functioning of that clock between men and women. One way of approaching the data is to compute individual regressions of produced duration (P) on target duration (T), after log transformation, and to derive estimates for the intercept and the slope. One could investigate a sex difference by comparing these estimates for men and women; one could also contrast them by looking at mean log(P). Using such indices, we found a sex difference in time production, female participants having a relatively faster internal clock, making shorter time productions, and having a smaller exponent. The question is whether a sex difference in time production would be found using other methods for analyzing the data: (1) the P/T ratio; (2) an absolute discrepancy (|P-T|) score; and (3) an absolute error (|P-T|/T) score. For the P/T ratio, female participants have a lower mean ratio in comparison to the male participants. In contrast, the |P-T| and |P-T|/T indices seem to be seriously compromised by wide individual differences.


Author(s):  
Nathan Walter ◽  
Yariv Tsfati

Abstract. This study examines the effect of interactivity on the attribution of responsibility for the character’s actions in a violent video game. Through an experiment, we tested the hypothesis that identification with the main character in Grand Theft Auto IV mediates the effect of interactivity on attributions of responsibility for the main character’s antisocial behavior. Using the framework of the fundamental attribution error, we demonstrated that those who actually played the game, as opposed to those who simply watched someone else playing it, identified with the main character. In accordance with the theoretical expectation, those who played the game and came to identify with the main character attributed the responsibility for his actions to external factors such as “living in a violent society.” By contrast, those who did not interact with the game attributed responsibility for the character’s actions to his personality traits. These findings could be viewed as contrasting with psychological research suggesting that respondents should have distanced themselves from the violent protagonist rather than identifying with him, and with Iyengar’s (1991) expectation that more personalized episodic framing would be associated with attributing responsibility to the protagonist.


PsycCRITIQUES ◽  
2006 ◽  
Vol 51 (30) ◽  
Author(s):  
Stephanie L. Brooke
Keyword(s):  

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