"The derivative of the quotient of two differentiable functions equal the denominator times the derivative of the numerator minus the numerator times the derivative of the denominator, all divided by the square of the denominator."
Washington, Allyn J. "Basic Technical Mathematics with Calculus." p.672. Chapter 23. The Derivative.
Thursday, November 15, 2007
Thursday, November 8, 2007
Does Chitin have UV protection properties?
Whilst considering the evolutionary advantage of Chitin, the exoskeleton of Arachnids and membrane of fungi, and it's benefits in an environment of high UV, prior to a substantial Ozone thickness; I was wondering if Chitin did in fact have UV protection factors?
Thursday, November 1, 2007
Adenine Obsession?
What is it about Adenine (A) H3N5C5 (approx. AMU = 133.1137), a double ringed purine with 2 hydrogen bonds, that seems to pop up everywhere in my Life Science studies? I found it in DNA, RNA, NAD+, CoEnzyme A, FAD+ and ever ATP!
Monday, October 8, 2007
Thursday, October 4, 2007
Wednesday, October 3, 2007
Brain connections cause rethink over human memory
Brain connections cause rethink over human memory
From issue 2621 of New Scientist magazine, 18 September 2007, page 23
How do we store so many memories? It is a question that has puzzled neuroscientists for decades - and now it seems that our concept of how memory works may have been wrong all along.
It was originally assumed that the number of memories was proportional to the number of neurons in a network. Given that even 1 cubic centimetre of the brain's cortex contains about 50 million neurons, it seemed that the brain could indeed store masses of information. However, this model relied on the notion that each neuron is connected to every other neuron, whereas a neuron is actually connected to between 5000 and 10,000 others.
Neuroscientists then proposed that the number of memories was proportional to the number of connections per neuron. Now Yasser Roudi and Peter Latham at University College London have found a problem with this model too. They calculated that even with 10,000 connections per neuron, a network could only store about 100 memories - regardless of how many neurons were in the network (PLoS Computational Biology, DOI: 10.1371/journal.pcbi.0030141).
This implies that to store a large amount of information, the brain would have to use multiple networks. This may be problematic for something like vocabulary, Latham says. "You wouldn't want to store 100 words in each of [many] different networks; you probably want to store them more or less in one place. Now we don't know how [the brain] does this."
From issue 2621 of New Scientist magazine, 18 September 2007, page 23
How do we store so many memories? It is a question that has puzzled neuroscientists for decades - and now it seems that our concept of how memory works may have been wrong all along.
It was originally assumed that the number of memories was proportional to the number of neurons in a network. Given that even 1 cubic centimetre of the brain's cortex contains about 50 million neurons, it seemed that the brain could indeed store masses of information. However, this model relied on the notion that each neuron is connected to every other neuron, whereas a neuron is actually connected to between 5000 and 10,000 others.
Neuroscientists then proposed that the number of memories was proportional to the number of connections per neuron. Now Yasser Roudi and Peter Latham at University College London have found a problem with this model too. They calculated that even with 10,000 connections per neuron, a network could only store about 100 memories - regardless of how many neurons were in the network (PLoS Computational Biology, DOI: 10.1371/journal.pcbi.0030141).
This implies that to store a large amount of information, the brain would have to use multiple networks. This may be problematic for something like vocabulary, Latham says. "You wouldn't want to store 100 words in each of [many] different networks; you probably want to store them more or less in one place. Now we don't know how [the brain] does this."
Ketamine relieves depression within hours
Ketamine relieves depression within hours
12:57 08 August 2006
NewScientist.com news service
Roxanne Khamsi
A drug used as a general anaesthetic may also work as a remarkably rapid antidepressant, according to a preliminary study.
The drug’s hallucinogenic side effects mean it is unlikely to be prescribed to patients, but it could pave the way to new faster-acting antidepressants, the researchers suggest.
Ketamine is used as an animal tranquiliser, but is perhaps better known as an illicit street drug, sometimes called “special K”. Now researchers have found the drug can relieve depression in some patients within just 2 hours – and continue to do so for a week.
One problem with current antidepressants is that they typically take weeks to kick in. Some studies have found that patients may face a high risk of suicide in the first week after starting an antidepressant treatment because of this lag time. So researchers have been searching for alternative drugs.
Fast acting
In 2000, a small study of eight people with major depression suggested that ketamine mitigated depression to a certain degree (Biological Psychiatry, vol 47, p 351).
Carlos Zarate, chief of the Mood and Anxiety Disorders Research Unit at the National Institute of Mental Health in Bethesda, Maryland, US and colleagues, set out to conduct a larger, more detailed trial of the drug’s antidepressant effects.
They analysed data from 17 participants, all whom suffered from moderate to severe depression and had failed to respond to at least two types of conventional drug treatments....
12:57 08 August 2006
NewScientist.com news service
Roxanne Khamsi
A drug used as a general anaesthetic may also work as a remarkably rapid antidepressant, according to a preliminary study.
The drug’s hallucinogenic side effects mean it is unlikely to be prescribed to patients, but it could pave the way to new faster-acting antidepressants, the researchers suggest.
Ketamine is used as an animal tranquiliser, but is perhaps better known as an illicit street drug, sometimes called “special K”. Now researchers have found the drug can relieve depression in some patients within just 2 hours – and continue to do so for a week.
One problem with current antidepressants is that they typically take weeks to kick in. Some studies have found that patients may face a high risk of suicide in the first week after starting an antidepressant treatment because of this lag time. So researchers have been searching for alternative drugs.
Fast acting
In 2000, a small study of eight people with major depression suggested that ketamine mitigated depression to a certain degree (Biological Psychiatry, vol 47, p 351).
Carlos Zarate, chief of the Mood and Anxiety Disorders Research Unit at the National Institute of Mental Health in Bethesda, Maryland, US and colleagues, set out to conduct a larger, more detailed trial of the drug’s antidepressant effects.
They analysed data from 17 participants, all whom suffered from moderate to severe depression and had failed to respond to at least two types of conventional drug treatments....
New drugs could spell quick fix for depression
New drugs could spell quick fix for depression
From issue 2620 of New Scientist magazine, 08 September 2007, page 21
SNAPPING out of depression is easier said than done.
Antidepressants such as selective serotonin reuptake inhibitors (SSRIs) can take several weeks to kick in, and for some patients there is an urgent need for a faster-acting drug. Now Guillaume Lucas at McGill University in Montreal, Canada, and his team have found a class of antidepressants that reverse symptoms of depression in rats within days.
The drug, RS67333, works by binding to a receptor on the surface of brain cells and stimulating them to release more serotonin, a neurotransmitter that helps control mood.
Rats with symptoms of depression returned to normal after just three days of injections with the drug, while those treated with a standard SSRI took two weeks to recover (Neuron, DOI: 10.1016/j.neuron.2007.07.041).
From issue 2620 of New Scientist magazine, 08 September 2007, page 21
SNAPPING out of depression is easier said than done.
Antidepressants such as selective serotonin reuptake inhibitors (SSRIs) can take several weeks to kick in, and for some patients there is an urgent need for a faster-acting drug. Now Guillaume Lucas at McGill University in Montreal, Canada, and his team have found a class of antidepressants that reverse symptoms of depression in rats within days.
The drug, RS67333, works by binding to a receptor on the surface of brain cells and stimulating them to release more serotonin, a neurotransmitter that helps control mood.
Rats with symptoms of depression returned to normal after just three days of injections with the drug, while those treated with a standard SSRI took two weeks to recover (Neuron, DOI: 10.1016/j.neuron.2007.07.041).
Biofuel made from power plant CO2
Biofuel made from power plant CO2
New Scientist
06 October 2006
Phil Mckenna
Magazine issue 2572
"If you're working at a power plant, you just saw your carbon dioxide turned into something you can drive home with." So says Isaac Berzin of GreenFuel Technologies in Cambridge, Massachusetts, which is developing a way of producing biofuel from the noxious emissions of power plants.
Two of the world's greatest energy users are electricity generation and transport. Both are responsible for huge quantities of greenhouse gas emissions, as most power plants and vehicles still rely on fossil fuels. Now GreenFuel and others are hoping to marry the two together with an emerging technology that uses a by-product of one to supply fuel to the other. Doing so could dramatically reduce their overall carbon dioxide emissions.
At the heart of the technology is a plastic cylinder full of algae, which literally sucks the CO2 out of a power plant's exhaust. The algae can in turn be converted into biofuel, creating ...
New Scientist
06 October 2006
Phil Mckenna
Magazine issue 2572
"If you're working at a power plant, you just saw your carbon dioxide turned into something you can drive home with." So says Isaac Berzin of GreenFuel Technologies in Cambridge, Massachusetts, which is developing a way of producing biofuel from the noxious emissions of power plants.
Two of the world's greatest energy users are electricity generation and transport. Both are responsible for huge quantities of greenhouse gas emissions, as most power plants and vehicles still rely on fossil fuels. Now GreenFuel and others are hoping to marry the two together with an emerging technology that uses a by-product of one to supply fuel to the other. Doing so could dramatically reduce their overall carbon dioxide emissions.
At the heart of the technology is a plastic cylinder full of algae, which literally sucks the CO2 out of a power plant's exhaust. The algae can in turn be converted into biofuel, creating ...
Artificial soil: quick and dirty
Artificial soil: quick and dirty
New Scientist
13 August 2007
Jessica Marshall
Magazine issue 2616
YOU might think it's as common as muck. Dirt cheap, even. In fact, the soil beneath our feet is anything but. Good, fertile topsoil is crucial for 97 per cent of the world's food supply, and without it parks and gardens would look more brown than green. So it's a worry that soil has joined the long list of resources that are beginning to run out - and there is no natural way to replace it in our lifetime. But soon there might be. By mixing together a bit of animal, vegetable and mineral, researchers are turning waste into fertile ground.
Making soil is a complicated business. In nature it develops when weathered rock and decomposing plant and animal material are mixed and broken down by plant roots, soil fauna, microbes and fungi. Over hundreds of years, if the chemical and biological mix is right, the raw ingredients are ...
... Others are trying similar approaches. Richard Haynes at the University of Queensland, Australia, is trialling a mix of fly ash and chicken litter, composted together with tree and garden waste, as part of a government and industry-sponsored effort to turn waste into new soil. ...
New Scientist
13 August 2007
Jessica Marshall
Magazine issue 2616
YOU might think it's as common as muck. Dirt cheap, even. In fact, the soil beneath our feet is anything but. Good, fertile topsoil is crucial for 97 per cent of the world's food supply, and without it parks and gardens would look more brown than green. So it's a worry that soil has joined the long list of resources that are beginning to run out - and there is no natural way to replace it in our lifetime. But soon there might be. By mixing together a bit of animal, vegetable and mineral, researchers are turning waste into fertile ground.
Making soil is a complicated business. In nature it develops when weathered rock and decomposing plant and animal material are mixed and broken down by plant roots, soil fauna, microbes and fungi. Over hundreds of years, if the chemical and biological mix is right, the raw ingredients are ...
... Others are trying similar approaches. Richard Haynes at the University of Queensland, Australia, is trialling a mix of fly ash and chicken litter, composted together with tree and garden waste, as part of a government and industry-sponsored effort to turn waste into new soil. ...
Friday, September 28, 2007
Svante August Arrhenius (1859-1927)
Linked acid behaviour to the presence of H+ ions, and base to OH- in water.
Tuesday, September 25, 2007
Saturday, September 15, 2007
Friday, September 14, 2007
The role of nutritional factors on the structure and function of the brain: an update on dietary requirements.
Title: The role of nutritional factors on the structure and function of the brain: an update on dietary requirements.
Author(s): Bourre, J.-M. (jean-marie.bourre@fwidal.inserm.fr)
Source: Revue Neurologique (Paris) 160 (8-9) : 767-792 September 2004
Language: French Medium: print
Abstract: The brain is an organ elaborated and functioning from substances present in the diet. Dietary regulation of blood glucose level (via ingestion of food with a low glycemic index ensuring a low insulin level) improves the quality and duration of intellectual performance, if only because at rest the adult brain consumes 50 p. 100 of dietary carbohydrates, 80 p. 100 of them for energy purposes. The nature of the amino acid composition of dietary proteins contributes to good cerebral function; tryptophan plays a special role. Many indispensable amino acids present in dietary proteins help to elaborate neurotransmitters and neuromodulators. Omega-3 fatty acids provided the first coherent experimental demonstration of the effect of dietary nutrients on the structure and function of the brain. First it was shown that the differentiation and functioning of cultured brain cells requires omega-3 fatty acids. It was then demonstrated that alpha-linolenic acid (ALA) deficiency al!
ters the course of brain development, perturbs the composition and physicochemical properties of brain cell membranes, neurones, oligodendrocytes, and astrocytes (ALA). This leads to physicochemical modifications, induces biochemical and physiological perturbations, and results in neurosensory and behavioral upset. Consequently, the nature of polyunsaturated fatty acids (in particular omega-3) present in formula milks for infants (premature and term) conditions the visual and cerebral abilities, including intellectual abilities. Moreover, dietary omega-3 fatty acids are certainly involved in the prevention of some aspects of cardiovascular disease (including at the level of cerebral vascularization), and in some neuropsychiatric disorders, particularly depression, as well as in dementia, notably Alzheimer's disease. Their deficiency can prevent the satisfactory renewal of membranes and thus accelerate cerebral aging. Iron is necessary to ensure oxygenation, to produce energy i!
n the cerebral parenchyma, and for the synthesis of neurotr!
ansmiters. The iodine provided by the thyroid hormone ensures the energy metabolism of the cerebral cells. The absence of iodine during pregnancy induces severe cerebral dysfunction, leading to cretinism. Manganese, copper, and zinc participate in enzymatic mechanisms that protect against free radicals, toxic derivatives of oxygen. The use of glucose by nervous tissue implies the presence of vitamin B1. Vitamin B9 preserves memory during aging, and with vitamin B12 delays the onset of signs of dementia, provided it is administered in a precise clinical window, at the onset of the first symptoms. Vitamins B6 and B12, among others, are directly involved in the synthesis of neurotransmitters. Nerve endings contain the highest concentrations of vitamin C in the human body. Among various vitamin E components, only alpha-tocopherol is involved in nervous membranes. The objective of this update is to give an overview of the effects of dietary nutrients on the structure and certain fu!
nctions of the brain.
Address: Bourre, J.-M.; INSERMU26Unite Rech and Neuropharm Nutr, Hop Fernand Widal, 200,Rue Faubourg, Paris, 10, France
ISSN: 0035-3787
Author(s): Bourre, J.-M. (jean-marie.bourre@fwidal.inserm.fr)
Source: Revue Neurologique (Paris) 160 (8-9) : 767-792 September 2004
Language: French Medium: print
Abstract: The brain is an organ elaborated and functioning from substances present in the diet. Dietary regulation of blood glucose level (via ingestion of food with a low glycemic index ensuring a low insulin level) improves the quality and duration of intellectual performance, if only because at rest the adult brain consumes 50 p. 100 of dietary carbohydrates, 80 p. 100 of them for energy purposes. The nature of the amino acid composition of dietary proteins contributes to good cerebral function; tryptophan plays a special role. Many indispensable amino acids present in dietary proteins help to elaborate neurotransmitters and neuromodulators. Omega-3 fatty acids provided the first coherent experimental demonstration of the effect of dietary nutrients on the structure and function of the brain. First it was shown that the differentiation and functioning of cultured brain cells requires omega-3 fatty acids. It was then demonstrated that alpha-linolenic acid (ALA) deficiency al!
ters the course of brain development, perturbs the composition and physicochemical properties of brain cell membranes, neurones, oligodendrocytes, and astrocytes (ALA). This leads to physicochemical modifications, induces biochemical and physiological perturbations, and results in neurosensory and behavioral upset. Consequently, the nature of polyunsaturated fatty acids (in particular omega-3) present in formula milks for infants (premature and term) conditions the visual and cerebral abilities, including intellectual abilities. Moreover, dietary omega-3 fatty acids are certainly involved in the prevention of some aspects of cardiovascular disease (including at the level of cerebral vascularization), and in some neuropsychiatric disorders, particularly depression, as well as in dementia, notably Alzheimer's disease. Their deficiency can prevent the satisfactory renewal of membranes and thus accelerate cerebral aging. Iron is necessary to ensure oxygenation, to produce energy i!
n the cerebral parenchyma, and for the synthesis of neurotr!
ansmiters. The iodine provided by the thyroid hormone ensures the energy metabolism of the cerebral cells. The absence of iodine during pregnancy induces severe cerebral dysfunction, leading to cretinism. Manganese, copper, and zinc participate in enzymatic mechanisms that protect against free radicals, toxic derivatives of oxygen. The use of glucose by nervous tissue implies the presence of vitamin B1. Vitamin B9 preserves memory during aging, and with vitamin B12 delays the onset of signs of dementia, provided it is administered in a precise clinical window, at the onset of the first symptoms. Vitamins B6 and B12, among others, are directly involved in the synthesis of neurotransmitters. Nerve endings contain the highest concentrations of vitamin C in the human body. Among various vitamin E components, only alpha-tocopherol is involved in nervous membranes. The objective of this update is to give an overview of the effects of dietary nutrients on the structure and certain fu!
nctions of the brain.
Address: Bourre, J.-M.; INSERMU26Unite Rech and Neuropharm Nutr, Hop Fernand Widal, 200,Rue Faubourg, Paris, 10, France
ISSN: 0035-3787
Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects
Title: Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects
Author(s): Fontani, G. (fontanig@unisi.it); Corradeschi, F.; Felici, A.; Alfatti, F.; Migliorini, S.; Lodi, L.
Source: European Journal of Clinical Investigation 35 (11) : 691-699 NOV 2005
Abstract: Background It has been reported that Omega-3 fatty acids may play a role in nervous system activity and that they improve cognitive development and reference memory-related learning, increase neuroplasticity of nerve membranes, contribute to synaptogenesis and are involved in synaptic transmission. The aim of this study was to examine the effects of Omega-3 supplementation on some cognitive and physiological parameters in healthy subjects.Materials and methods Subjects were tested at the beginning of the experiment and after 35 days. In this period they were supplemented with Omega-3 polyunsaturated fatty acids. A group was supplemented with olive oil (placebo). Tests involving different types of attention were used, i.e. Alert, Go/No-Go, Choice and Sustained Attention. For each test, the reaction time, the event-related potentials by electroencephalogram (EEG) and the electromyography (EMG) of the forefinger flexor muscle were recorded. The Profile of Mood States te!
st (POMS) was also administered.Results Blood analyses showed that after Omega-3 supplementation the arachidonic acid/eicosapentaenoic acid ratio (AA/EPA) was strongly reduced. The mood profile was improved after Omega-3 with increased vigour and reduced anger, anxiety and depression states. This was associated with an effect on reactivity with a reduction of reaction time in the Go/No-Go and Sustained Attention tests. The latency of EMG activation was concomitantly reduced in the same tests plus Choice. An EEG frequency shift towards the theta and alpha band were recorded in all the tests after Omega-3.Conclusion Omega-3 supplementation is associated with an improvement of attentional and physiological functions, particularly those involving complex cortical processing. These findings are discussed in terms of the influence of Omega-3 on the central nervous system.
Address: Fontani, G. ; Univ Siena, Dipartimento Fisiol, Sez Neurosci and Fisiol Applicata, Via A Moro 3, I-53100 Siena, Italy
ISSN: 0014-2972
Author(s): Fontani, G. (fontanig@unisi.it); Corradeschi, F.; Felici, A.; Alfatti, F.; Migliorini, S.; Lodi, L.
Source: European Journal of Clinical Investigation 35 (11) : 691-699 NOV 2005
Abstract: Background It has been reported that Omega-3 fatty acids may play a role in nervous system activity and that they improve cognitive development and reference memory-related learning, increase neuroplasticity of nerve membranes, contribute to synaptogenesis and are involved in synaptic transmission. The aim of this study was to examine the effects of Omega-3 supplementation on some cognitive and physiological parameters in healthy subjects.Materials and methods Subjects were tested at the beginning of the experiment and after 35 days. In this period they were supplemented with Omega-3 polyunsaturated fatty acids. A group was supplemented with olive oil (placebo). Tests involving different types of attention were used, i.e. Alert, Go/No-Go, Choice and Sustained Attention. For each test, the reaction time, the event-related potentials by electroencephalogram (EEG) and the electromyography (EMG) of the forefinger flexor muscle were recorded. The Profile of Mood States te!
st (POMS) was also administered.Results Blood analyses showed that after Omega-3 supplementation the arachidonic acid/eicosapentaenoic acid ratio (AA/EPA) was strongly reduced. The mood profile was improved after Omega-3 with increased vigour and reduced anger, anxiety and depression states. This was associated with an effect on reactivity with a reduction of reaction time in the Go/No-Go and Sustained Attention tests. The latency of EMG activation was concomitantly reduced in the same tests plus Choice. An EEG frequency shift towards the theta and alpha band were recorded in all the tests after Omega-3.Conclusion Omega-3 supplementation is associated with an improvement of attentional and physiological functions, particularly those involving complex cortical processing. These findings are discussed in terms of the influence of Omega-3 on the central nervous system.
Address: Fontani, G. ; Univ Siena, Dipartimento Fisiol, Sez Neurosci and Fisiol Applicata, Via A Moro 3, I-53100 Siena, Italy
ISSN: 0014-2972
Cultural symbolism of fish and the psychotropic properties of omega-3 fatty acids
Title: Cultural symbolism of fish and the psychotropic properties of omega-3 fatty acids
Author(s): Reis, L. C.; Hibbeln, J. R. (jhibbeln@mail.nih.gov)
Source: Prostaglandins Leukotrienes and Essential Fatty Acids 75 (4-5) : 227-236 OCT-NOV 2006
Abstract: Fish is a food with unique psychotropic properties. Consumption of long-chain omega-3 fatty acids, rich in seafood, reduces depression, aggression and anger while improving mental well-being. We posit that symbols of fish have become linked to the emotional states induced by long-chain fatty acid by associative pairings, both conscious and unconscious. The limbic and hippocampal activity necessary for memory formation containing emotional content and the labeling of social context by cortical processes appears to be optimized by diets rich in long-chain omega-3 fatty acid. In this critical literature survey, we find that fish have been culturally labeled as symbols of emotional well-being and social healing in religious and medical practices among independent cultures, for at least six millennia. This understanding of the perception of fish as a symbolically healing or purifying food can assist current messages improving public health. (c) 2006 Elsevier Ltd. All righ!
ts reserved.
Address: Hibbeln, J. R.; 31 Ctr Dr 31-1B58, Bethesda, MD USA
ISSN: 0952-3278
Author(s): Reis, L. C.; Hibbeln, J. R. (jhibbeln@mail.nih.gov)
Source: Prostaglandins Leukotrienes and Essential Fatty Acids 75 (4-5) : 227-236 OCT-NOV 2006
Abstract: Fish is a food with unique psychotropic properties. Consumption of long-chain omega-3 fatty acids, rich in seafood, reduces depression, aggression and anger while improving mental well-being. We posit that symbols of fish have become linked to the emotional states induced by long-chain fatty acid by associative pairings, both conscious and unconscious. The limbic and hippocampal activity necessary for memory formation containing emotional content and the labeling of social context by cortical processes appears to be optimized by diets rich in long-chain omega-3 fatty acid. In this critical literature survey, we find that fish have been culturally labeled as symbols of emotional well-being and social healing in religious and medical practices among independent cultures, for at least six millennia. This understanding of the perception of fish as a symbolically healing or purifying food can assist current messages improving public health. (c) 2006 Elsevier Ltd. All righ!
ts reserved.
Address: Hibbeln, J. R.; 31 Ctr Dr 31-1B58, Bethesda, MD USA
ISSN: 0952-3278
NUTRIENTS THAT MODIFY THE SPEED OF INTERNAL CLOCK AND MEMORY STORAGE PROCESSES
Title: NUTRIENTS THAT MODIFY THE SPEED OF INTERNAL CLOCK AND MEMORY STORAGE PROCESSES
Author(s): MECK W H; CHURCH R M
Source: Behavioral Neuroscience 101 (4) : 465-475 1987
Abstract: Two experiments assessed the effects of nutrients on timing behavior by rats. The nutrients were laced with saccharin and given to rats as a snack before training on a 20-s peak-interval procedure. The primary component of the snacks for four groups of 10 rats was lecithin (phosphatidylcholine), protein (casein), carbohydrate (sucrose), or an nonnutrient (saccharin). The primary measures of behavior was the time of the rat's highest response rate during a trial (peak time), which represented the interval during which the rat maximally expected food. With a lecithin snack, peak time was gradually shifted over sessions to a shorter time, remained shifted to the left of the normal function with additional testing, and then remained at the shorter time on two sessions after the snack was discontinued; with the protein snack, peak time was abruptly shifted to a shorter time, returned to normal with additional testing, and then rebounded to a longer time when the snack was!
discontinued; with a carbohydrate, snack peak time was abruptly shifted to a longer time, returned to normal with additional testing, and then rebounded to a shorter time when the snack was discontinued. The behavioral patterns produced by the nutrients were interpreted in terms of precursor effects of central neurotransmitter synthesis and release, psychological stages of an information-processing model, and mathematical parameters of a scalar timing theory.
Address: MECK W H ; DEP PSYCHOL, COLUMBIA UNIV, NEW YORK, NY 10027, USA
ISSN: 0735-7044
Author(s): MECK W H; CHURCH R M
Source: Behavioral Neuroscience 101 (4) : 465-475 1987
Abstract: Two experiments assessed the effects of nutrients on timing behavior by rats. The nutrients were laced with saccharin and given to rats as a snack before training on a 20-s peak-interval procedure. The primary component of the snacks for four groups of 10 rats was lecithin (phosphatidylcholine), protein (casein), carbohydrate (sucrose), or an nonnutrient (saccharin). The primary measures of behavior was the time of the rat's highest response rate during a trial (peak time), which represented the interval during which the rat maximally expected food. With a lecithin snack, peak time was gradually shifted over sessions to a shorter time, remained shifted to the left of the normal function with additional testing, and then remained at the shorter time on two sessions after the snack was discontinued; with the protein snack, peak time was abruptly shifted to a shorter time, returned to normal with additional testing, and then rebounded to a longer time when the snack was!
discontinued; with a carbohydrate, snack peak time was abruptly shifted to a longer time, returned to normal with additional testing, and then rebounded to a shorter time when the snack was discontinued. The behavioral patterns produced by the nutrients were interpreted in terms of precursor effects of central neurotransmitter synthesis and release, psychological stages of an information-processing model, and mathematical parameters of a scalar timing theory.
Address: MECK W H ; DEP PSYCHOL, COLUMBIA UNIV, NEW YORK, NY 10027, USA
ISSN: 0735-7044
The influence on cognition of the interactions between lecithin, carnitine and carbohydrate
Title: The influence on cognition of the interactions between lecithin, carnitine and carbohydrate
Author(s): Benton, David (d.benton@swansea.ac.uk); Donohoe, Rachael T.
Source: Psychopharmacology 175 (1) : 84-91 August 2004
Abstract: It is accepted that acetylcholine-mediated neurones modulate memory. As lecithin, carnitine and glucose all influence acetylcholine metabolism, the possibility of synergistic interactions was considered. Four hundred young adult females randomly, and under a double-blind procedure, received capsules for 3 days that contained a placebo, lecithin (1.6 g/day), carnitine (500 mg/day) or carnitine plus lecithin. A battery of cognitive tests was administered prior to taking the capsules, after 3 days of taking the supplements, and for a third time after consuming either a glucose drink or a placebo. Reaction times were more rapid when carnitine and a glucose drink were taken together. Memory was enhanced in those taking a glucose rather than placebo drink. Neither mood nor the ability to sustain attention were influenced by these procedures. The hypothesis that memory would be facilitated by offering supplements of lecithin, carnitine and glucose was not supported.
Address: Benton, David ; Dept Psychol, Univ Wales, Swansea, W Glam, SA2 8PP, UK
ISSN: 0033-3158 (ISSN print)
Author(s): Benton, David (d.benton@swansea.ac.uk); Donohoe, Rachael T.
Source: Psychopharmacology 175 (1) : 84-91 August 2004
Abstract: It is accepted that acetylcholine-mediated neurones modulate memory. As lecithin, carnitine and glucose all influence acetylcholine metabolism, the possibility of synergistic interactions was considered. Four hundred young adult females randomly, and under a double-blind procedure, received capsules for 3 days that contained a placebo, lecithin (1.6 g/day), carnitine (500 mg/day) or carnitine plus lecithin. A battery of cognitive tests was administered prior to taking the capsules, after 3 days of taking the supplements, and for a third time after consuming either a glucose drink or a placebo. Reaction times were more rapid when carnitine and a glucose drink were taken together. Memory was enhanced in those taking a glucose rather than placebo drink. Neither mood nor the ability to sustain attention were influenced by these procedures. The hypothesis that memory would be facilitated by offering supplements of lecithin, carnitine and glucose was not supported.
Address: Benton, David ; Dept Psychol, Univ Wales, Swansea, W Glam, SA2 8PP, UK
ISSN: 0033-3158 (ISSN print)
ACTION OF A PHOSPHOSERINE GLUTAMINE VITAMIN B-12 COMBINATION ON PSYCHOPHYSICAL ACTIVITY OF HIGH SCHOOL STUDENTS
Title: ACTION OF A PHOSPHOSERINE GLUTAMINE VITAMIN B-12 COMBINATION ON PSYCHOPHYSICAL ACTIVITY OF HIGH SCHOOL STUDENTS
Author(s): DI NARO C; GINI M; SCHIAVI M
Source: Clinica Terapeutica 114 (3) : 225-232 1985
Language: ITALIAN
Abstract: Thirty high-school students were treated with a phosphoserine-glutamine-vitamin B12 combination, and the basal and final results of various items and test were compared. An overall improvement was observed in 83.3% of the cases with reduction of tiredness and emotional instability and increased learning capacity and memory. The combination was well tolerated and side effects were not observed.
Address: DI NARO C ; VIA BAINSIZZA, 2 - MILANO
ISSN: 0009-9074
Author(s): DI NARO C; GINI M; SCHIAVI M
Source: Clinica Terapeutica 114 (3) : 225-232 1985
Language: ITALIAN
Abstract: Thirty high-school students were treated with a phosphoserine-glutamine-vitamin B12 combination, and the basal and final results of various items and test were compared. An overall improvement was observed in 83.3% of the cases with reduction of tiredness and emotional instability and increased learning capacity and memory. The combination was well tolerated and side effects were not observed.
Address: DI NARO C ; VIA BAINSIZZA, 2 - MILANO
ISSN: 0009-9074
Involvement of amino acids, opioids, nitric oxide, and NMDA receptors in learning and memory consolidation in crickets
Title: Involvement of amino acids, opioids, nitric oxide, and NMDA receptors in learning and memory consolidation in crickets
Author(s): Jaffe, Klaus; Blanco, Maria Esther
Source: Pharmacology Biochemistry and Behavior 47 (3) : 493-496 1994
Abstract: The effect of injections of selected acids and of N-methyl-D-aspartate (NMDA); morphine; and NMDA, nitric oxide (NO), and opioid inhibitors given before a maze-learning was investigated. Thirsty crickets (Pteronemobius sp) were trained to turn only to one side of a symmetrical Y-shaped maze using reinforcements with water. The insects retained the learned task 24 h later. N-2 anoxia applied immediately after training produced retrograde amnesia. Injections of alanine (Ala), arginine (Arg), glutamine (Gin), morphine, or NMDA prior to training blocked the amnesic action of anoxia. Naloxone, an opioid antagonist, blocked long-term memory formation, but not learning, whereas hemoglobin or 2-amino-5-phosphonovaleric acid (APV), NO and NMDA antagonists respectively, blocked both. The antiamnesic effect of Morphine and Arg, but not that of Ala or NMDA was blocked by naloxone. The results suggest involvement of NMDA receptors and NO and thus of long-term potentiation phenome!
na in learning and in memory consolidation, whereas other neuromodulatory systems related to Arg, and opiate receptors, are only involved in memory consolidation.
Address: Dep. Biologia Organgismos, Universidad Simon Bolivar, Apartado 89000, Caracas 1980, Venezuela
ISSN: 0091-3057
Author(s): Jaffe, Klaus; Blanco, Maria Esther
Source: Pharmacology Biochemistry and Behavior 47 (3) : 493-496 1994
Abstract: The effect of injections of selected acids and of N-methyl-D-aspartate (NMDA); morphine; and NMDA, nitric oxide (NO), and opioid inhibitors given before a maze-learning was investigated. Thirsty crickets (Pteronemobius sp) were trained to turn only to one side of a symmetrical Y-shaped maze using reinforcements with water. The insects retained the learned task 24 h later. N-2 anoxia applied immediately after training produced retrograde amnesia. Injections of alanine (Ala), arginine (Arg), glutamine (Gin), morphine, or NMDA prior to training blocked the amnesic action of anoxia. Naloxone, an opioid antagonist, blocked long-term memory formation, but not learning, whereas hemoglobin or 2-amino-5-phosphonovaleric acid (APV), NO and NMDA antagonists respectively, blocked both. The antiamnesic effect of Morphine and Arg, but not that of Ala or NMDA was blocked by naloxone. The results suggest involvement of NMDA receptors and NO and thus of long-term potentiation phenome!
na in learning and in memory consolidation, whereas other neuromodulatory systems related to Arg, and opiate receptors, are only involved in memory consolidation.
Address: Dep. Biologia Organgismos, Universidad Simon Bolivar, Apartado 89000, Caracas 1980, Venezuela
ISSN: 0091-3057
The neuropharmacology of L-theanine(N-ethyl-L-glutamine): A possible neuroprotective and cognitive enhancing agent
Title: The neuropharmacology of L-theanine(N-ethyl-L-glutamine): A possible neuroprotective and cognitive enhancing agent
Author(s): Nathan, Pradeep J. (Pradeep.Nathan@med.monash.edu.au); Lu, Kristy; Gray, M.; Oliver, C.
Source: Journal of Herbal Pharmacotherapy 6 (2) : 21-30 2006
Abstract: L-theanine (N-ethyl-L-glutamine) or theanine is a major amino acid uniquely found in green tea. L-theanine has been historically reported as a relaxing agent, prompting scientific research on its pharmacology. Animal neurochemistry studies Suggest that L-theanine increases brain serotonin, dopamine, GABA levels and has micromolar affinities for AMPA, Kainate and NMDA receptors. In addition has been shown to exert neuroprotective effects in animal models possibly through its antagonistic effects on group 1 metabotrophic glutamate receptors. Behavioural studies in animals suggest improvement in learning and memory. Overall, L-theanine displays a neuropharmacology Suggestive of a possible neuroprotective and cognitive enhancing agent and warrants further investigation in animals and humans.
Address: Nathan, Pradeep J. ; Monash Univ, Dept Physiol, Behav Neurosci Lab, Monash Ctr Brain and Behav, POB 13F, Clayton, Vic 3800, Australia
ISSN: 1522-8940
Author(s): Nathan, Pradeep J. (Pradeep.Nathan@med.monash.edu.au); Lu, Kristy; Gray, M.; Oliver, C.
Source: Journal of Herbal Pharmacotherapy 6 (2) : 21-30 2006
Abstract: L-theanine (N-ethyl-L-glutamine) or theanine is a major amino acid uniquely found in green tea. L-theanine has been historically reported as a relaxing agent, prompting scientific research on its pharmacology. Animal neurochemistry studies Suggest that L-theanine increases brain serotonin, dopamine, GABA levels and has micromolar affinities for AMPA, Kainate and NMDA receptors. In addition has been shown to exert neuroprotective effects in animal models possibly through its antagonistic effects on group 1 metabotrophic glutamate receptors. Behavioural studies in animals suggest improvement in learning and memory. Overall, L-theanine displays a neuropharmacology Suggestive of a possible neuroprotective and cognitive enhancing agent and warrants further investigation in animals and humans.
Address: Nathan, Pradeep J. ; Monash Univ, Dept Physiol, Behav Neurosci Lab, Monash Ctr Brain and Behav, POB 13F, Clayton, Vic 3800, Australia
ISSN: 1522-8940
Thursday, September 13, 2007
Thursday, September 6, 2007
Electron-Domain Geometries make Plato happy
Platoic Solids are preferred in Electron-Domain Geometries!
I like my Ammonium Ion Trigonal pyramidal, if you are ordering.
Wednesday, September 5, 2007
'e' has changed m'e' life!
'e' is real.
'e' is irrational.
'e' is unique
'e's value is infinite!
'e' is one of the most important numbers in mathematics!
Sunday, September 2, 2007
Saturday, September 1, 2007
Creation
The Title of this Blog was inspired by QUT LSB118 LIfe Science where I learnt that the molecular shape of amino acid polymer conformations influence their purpose. Hence this Blog is to show the shape of the metaphorical conformation of existance from the subjective experience of Andrew Kettle.
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