Night Light Color Could Be Attitude Adjuster

Night Light Color Could Be Attitude Adjuster
Scientific American, October 28, 2013

Nocturnal Light Exposure Impairs Affective Responses in a Wavelength-Dependent Manner
The Journal of Neuroscience, 7 August 2013, 33(32): 13081-13087
Tracy A. Bedrosian, et al.

Life on earth is entrained to a 24 h solar cycle that synchronizes circadian rhythms in physiology and behavior;
light is the most potent entraining cue.

In mammals, light is detected by (1) rods and cones, which mediate visual function, and
(2) intrinsically photosensitive retinal ganglion cells (ipRGCs), which primarily project to the suprachiasmatic nucleus (SCN) in the hypothalamus to regulate circadian rhythms.

ipRGCs also project to limbic brain regions, suggesting that, through this pathway, light may have a role in cognition and mood. Therefore, unnatural exposure to light may have negative consequences for mood or behavior.

Modern environmental lighting conditions have led to excessive exposure to light at night (LAN), and particularly to blue wavelength lights.

We hypothesized that nocturnal light exposure (i.e., dim LAN) would induce depressive responses and alter neuronal structure in hamsters (Phodopus sungorus).
If this effect is mediated by ipRGCs, which have reduced sensitivity to red wavelength light, then we predicted that red LAN would have limited effects on brain and behavior compared with shorter wavelengths.
Additionally, red LAN would not induce c-Fos activation in the SCN.

Our results demonstrate that exposure to LAN influences behavior and neuronal plasticity and that this effect is likely mediated by ipRGCs.
Modern sources of LAN that contain blue wavelengths may be particularly disruptive to the circadian system, potentially contributing to altered mood regulation.


What’s Keeping You Awake at Night?
Scitable. by Nature Education. June 07, 2013

effects of LED backlit screens and their emission of a certain blue-light wavelength on melatonin levels, an essential hormone that makes you drowsy and kicks in your sleep cycle.
Melatonin is released naturally at the onset of darkness, preparing your body for rest, and then continuously throughout the night as part of your natural circadian rhythm – your body’s daily biological clock.
However, melatonin can be partially curbed by exposure to light, and the abnormally bright glow of backlit computer screens seems to be especially disruptive to its release.
Suppression of melatonin then has the opposite effects, increasing alertness and arousal, and even altering REM sleep patterns when you finally do nod off.


Drug-proof grapefruit

Drug-proof grapefruit
Nature Biotechnology 31, 186 (2013)

Citrus breeders at the University of Florida’s Citrus Research and Education Center display new varieties of grapefruit and pomelo hybrids that could resolve the problem of grapefruit/drug interactions.
The team developed the hybrid fruit as a cross between grapefruit and pummelo, a citrus species…


Effect of grapefruit juice on cabergoline pharmacokinetics in patients with Parkinson’s disease
Clinical Pharmacology & Therapeutics 77, P84 (February 2005)
M. Nagai, et. al.

Background: Cabergoline is one of the synthetic ergoline dopamine agonists, which is widely used for the treatment of Parkinson’s disease (PD). Cytochrome P-450 (CYP) 3A4 contributes to metabolize Cabergoline. It has been well known that grapefruit juice inhibits CYP3A4 enzyme located in the gut wall. To investigate whether grapefruit juice influences the pharmacokinetics of cabergoline, plasma level of cabergoline in patients of PD was evaluated.

Methods: Five patients with PD treated with cabergoline were enrolled. Plasma concentrations of cabergoline before and after coadministration of grapefruit juice were evaluated. The plasma concentration of cabergoline was determined using a LC/MS/MS.

Results: The plasma concentration of cabergoline increased approximately 1.7 times, when grapefruit juice was taken together with cabergoline. Adverse events were not observed during this trial.

Conclusions: Coadministration of grapefruit juice with cabergoline increases bioavailability of cabergoline. A relatively large therapeutic window of cabergoline may allow the concomitant treatment with grapefruit juice, and this combination treatment may augment the antiparkisonian effect of cabergoline.


Chemical ‘clock’ tracks ageing more precisely than ever before

DNA methylation suggests cancerous tissue ages faster than healthy tissue.

Chemical ‘clock’ tracks ageing more precisely than ever before
DNA methylation could shed light on why some tissues are prone to cancer.
Amanda Mascarelli
Nature. 21 October 2013

In a paper published today in Genome Biology, Horvath reveals how methylation levels change in human tissues from before birth to the age of 101, and shows that it is a near-perfect predictor of age for non-cancerous tissues.
The study “represents the most convincing demonstration so far” of age-associated changes in DNA methylation that are consistent across most tissue types, says Andrew Teschendorff, a computational biologist at University College London.


DNA methylation age of human tissues and cell types
Genome Biology 2013, 14(10):R115
Steve Horvath

Conclusions: I propose that DNA methylation age measures the cumulative effect of an epigenetic maintenance system. This novel epigenetic clock can be used to address a host of questions in developmental biology, cancer and aging research.


ScienceClub: Oct. 29, 2013

Why Are Bees Disappearing?

Why Are Bees Disappearing?
September 27, 2013

Bees don’t spend much time thinking about thinking … reflective thinking


> 1/3 of the world’s crops are dependent on bee pollination
tomato growers … tomato tickler … bumblebees
they vibrate the flower, they sonicate it

clover and alfalfa are highly nutritious plants for bees

pesticide residue

a crop 100% dependent on bees: almonds

Every one of us needs to behave a little bit more like a bee society, where each of our individual actions can contribute to a grand solution, an emergent property that’s much greater than the mere sum of our individual actions.


Drug laws & treatment innovation

Effects of Schedule I drug laws on neuroscience research and treatment innovation
David J. Nutt, Leslie A. King and David E. Nichols

draconian penalty

cannabis (marijuana)

lysergic acid diethylamide (LSD; also known as lysergide)

3,4-methyl- enedioxy-N-methylamphetamine (MDMA; also known as ecstasy)

psilocybin:  a hallucinogenic indole C12H17N2O4P obtained from a fungus (as Psilocybe mexicana or P. cubensis syn. Stropharia cubensis)

LSD has been used successfully to treat other addictions

there is no evidence that psychedelics have addictive properties

MDMA similarly has low dependence potential, although some chronic cannabis users can develop dependence

circular argument

in the United States, medical use of marijuana is legal in 18 states and in the District of Columbia.

cannabis was a prescription medication in the United Kingdom until the middle of the twentieth century

In practice, research with Schedule I drugs has almost completely ceased, with research into psychedelic drugs being particularly affected.

Δ9-tetrahydrocannabinol (THC), the psychoactive ingredient of cannabis that makes users ‘stoned’.

Overall, cannabis is less harmful than other popular drugs, such as alcohol.

related news release:


Environmental epigenomics and disease susceptibility

Alterations in methylation status during development.

Environmental epigenomics and disease susceptibility
Randy L. Jirtle and Michael K. Skinner
Nature Reviews Genetics 8, 253-262 (April 2007)

Alterations in methylation status during development.

During embryonic development and gonadal sex determination, primordial germ cells undergo genome-wide demethylation, which erases previous parental-specific methylation marks that regulate imprinted gene expression.

Use of a multiaxial diagnostic system in clinical genetics

Use of a multiaxial diagnostic system in clinical genetics
Genetics in Medicine (2002) 4, 95–96

a multiaxial diagnostic system (MADS) in clinical genetics3 similar to the DSM-III-R system used in psychiatry.
I thought this was important as the clinical diagnoses, and even the ICD codes, were a mixture of etiologic, pathogenetic mechanisms and phenotypic diagnoses.
For simplicity, only four major categorical axes were defined:
I, Phenotypic;
II, Pathogenetic;
III, Etiologic
IV, Differential Diagnoses

The major advantages of such a system included:

  • improved diagnostic accuracy;
  • greater reliability and homogeneity of the diagnostic categories, enhancing the comparison of diagnoses and achievements between different centers, states, regions, or countries;
  • more comprehensive and specific definitions for controversial terms such as “syndrome” or “spectrum”; and
  • its use for educating health professionals.

Research Interests: analysis of high-dimensional data
Teaching: Topics in High Dimensional Data Analysis (STAT:7190)