Thursday, December 10, 2009
Mathematical Model of Simple Circuit in Chicken Brain Raises Fundamental Questions About Neural Circuitry
The Web site Neuroanthropology asks visitors to complete this quote, "One of the difficulties in understanding the brain is …." In addition to the typical facetious remarks, such as "so few of us seem to have one" and "the damn thing is smart enough to realize what you are doing, and contrary enough to change the way it reacts just to spite you…," there are more serious ones, such as "… it's not a computer" and the methods we have available "are not enough accurate in saying how neural mechanisms correlates to behavior."
Migraine Headaches And Sexual Desire May Be Linked
Contrary to the popular cliché, "Not tonight, I have a headache," new research suggests that not all headache sufferers avoid sexual activity. In fact, migraine sufferers reported higher levels of sexual desire than those with other types of headaches, according to researchers from Wake Forest University School of Medicine and colleagues.
Exercise Program Reduces Migraine Suffering
While physical exercise has been shown to trigger migraine headaches among sufferers, a new study describes an exercise program that is well tolerated by patients. The findings show that the program decreased the frequency of headaches and improved quality of life.
The study used a sample of migraine sufferers who were examined before, during and after an aerobic exercise intervention. The program was based on indoor cycling (for continuous aerobic exercise) and was designed to improve maximal oxygen uptake without worsening the patients’ migraines.
After the treatment period, patients’ maximum oxygen uptake increased significantly. There was no worsening of migraine status at any time during the study period and, during the last month of treatment, there was a significant decrease in the number of migraine attacks, the number of days with migraine per month, headache intensity and amount of headache medication used.
Individuals with headache and migraine typically are less physically active than those without headache. Patients with migraine often avoid exercise, resulting in less aerobic endurance and flexibility. Therefore, well designed studies of exercise in patients with migraine are imperative.
“While the optimal amount of exercise for patients with migraine remains unknown, our evaluated program can now be tested further and compared to pharmacological and non-pharmacological treatments to see if exercise can prevent migraine,” says Dr. Emma Varkey, co-author of the study.
The study is published in Headache: The Journal of Head and Face Pain.
The study used a sample of migraine sufferers who were examined before, during and after an aerobic exercise intervention. The program was based on indoor cycling (for continuous aerobic exercise) and was designed to improve maximal oxygen uptake without worsening the patients’ migraines.
After the treatment period, patients’ maximum oxygen uptake increased significantly. There was no worsening of migraine status at any time during the study period and, during the last month of treatment, there was a significant decrease in the number of migraine attacks, the number of days with migraine per month, headache intensity and amount of headache medication used.
Individuals with headache and migraine typically are less physically active than those without headache. Patients with migraine often avoid exercise, resulting in less aerobic endurance and flexibility. Therefore, well designed studies of exercise in patients with migraine are imperative.
“While the optimal amount of exercise for patients with migraine remains unknown, our evaluated program can now be tested further and compared to pharmacological and non-pharmacological treatments to see if exercise can prevent migraine,” says Dr. Emma Varkey, co-author of the study.
The study is published in Headache: The Journal of Head and Face Pain.
Exercise Program Reduces Migraine Suffering
While physical exercise has been shown to trigger migraine headaches among sufferers, a new study describes an exercise program that is well tolerated by patients. The findings show that the program decreased the frequency of headaches and improved quality of life.
Treating Cluster Headaches With High-Flow Oxygen Appears Effective
Patients with a cluster headache, which is characterized by bouts of excruciating pain usually near the eye or temple, were more likely to report being pain-free within 15 minutes of treatment with high-flow oxygen than patients who received a placebo treatment, according to a study in the December 9 issue of JAMA.
Cluster headache attacks typically last for 15 minutes to 3 hours untreated and have a frequency of 1 every other day for up to 8 attacks a day. Attacks usually occur in bouts, or clusters, lasting for weeks or months, separated by remissions lasting months or years, according to background information in the article. The current treatment for acute attacks of cluster headache is injection with the drug sumatriptan, but frequent dosing is not recommended because of adverse effects. Another treatment option is the inhalation of high-dose, high-flow oxygen, but its use may be limited because of the lack of a good quality controlled trial.
Anna S. Cohen, Ph.D., M.R.C.P., of the National Hospital for Neurology and Neurosurgery, London, and colleagues conducted a randomized, placebo-controlled trial of high-flow oxygen for the treatment of acute attacks of cluster headache. The study included 109 adults (ages 18-70 years). Patients treated four cluster headache episodes alternately with high-flow oxygen (inhaled oxygen at 100 percent, 12 L/min, delivered by face mask, for 15 minutes at the start of an attack) or placebo (high-flow air). Patients were recruited and followed up between 2002 and 2007. The final analysis included 57 patients with episodic cluster headache and 19 with chronic cluster headache.
The researchers found that 78 percent of the patients who received oxygen reported being pain-free or to have adequate relief within 15 minutes of treatment, compared to 20 percent of patients who received air. For other outcomes, such as being pain-free at 30 minutes or a reduction in pain up to 60 minutes, treatment with oxygen was superior to air. There were no serious adverse events related to the treatments.
"To our knowledge, this is the first adequately powered trial of high-flow oxygen compared with placebo, and it confirms clinical experience and current guidelines that inhaled oxygen can be used as an acute attack therapy for episodic and chronic cluster headache," the authors write.
"This work paves the way for further studies to optimize the administration of oxygen and its more widespread use as an acute attack treatment in cluster headache, offering an evidence-based alternative to those who cannot take triptan agents."
Cluster headache attacks typically last for 15 minutes to 3 hours untreated and have a frequency of 1 every other day for up to 8 attacks a day. Attacks usually occur in bouts, or clusters, lasting for weeks or months, separated by remissions lasting months or years, according to background information in the article. The current treatment for acute attacks of cluster headache is injection with the drug sumatriptan, but frequent dosing is not recommended because of adverse effects. Another treatment option is the inhalation of high-dose, high-flow oxygen, but its use may be limited because of the lack of a good quality controlled trial.
Anna S. Cohen, Ph.D., M.R.C.P., of the National Hospital for Neurology and Neurosurgery, London, and colleagues conducted a randomized, placebo-controlled trial of high-flow oxygen for the treatment of acute attacks of cluster headache. The study included 109 adults (ages 18-70 years). Patients treated four cluster headache episodes alternately with high-flow oxygen (inhaled oxygen at 100 percent, 12 L/min, delivered by face mask, for 15 minutes at the start of an attack) or placebo (high-flow air). Patients were recruited and followed up between 2002 and 2007. The final analysis included 57 patients with episodic cluster headache and 19 with chronic cluster headache.
The researchers found that 78 percent of the patients who received oxygen reported being pain-free or to have adequate relief within 15 minutes of treatment, compared to 20 percent of patients who received air. For other outcomes, such as being pain-free at 30 minutes or a reduction in pain up to 60 minutes, treatment with oxygen was superior to air. There were no serious adverse events related to the treatments.
"To our knowledge, this is the first adequately powered trial of high-flow oxygen compared with placebo, and it confirms clinical experience and current guidelines that inhaled oxygen can be used as an acute attack therapy for episodic and chronic cluster headache," the authors write.
"This work paves the way for further studies to optimize the administration of oxygen and its more widespread use as an acute attack treatment in cluster headache, offering an evidence-based alternative to those who cannot take triptan agents."
Methamphetamine Abuse Linked To Underage Sex, Smoking And Drinking
Children and adolescents who abuse alcohol or are sexually active are more likely to take methamphetamines (MA), also known as 'meth' or 'speed'. New research reveals the risk factors associated with MA use, in both low-risk children (those who don't take drugs) and high-risk children (those who have taken other drugs or who have ever attended juvenile detention centres).
MA is a stimulant, usually smoked, snorted or injected. It produces sensations of euphoria, lowered inhibitions, feelings of invincibility, increased wakefulness, heightened sexual experiences, and hyperactivity resulting from increased energy for extended periods of time. According to the lead author of this study, Terry P. Klassen of the University of Alberta, Canada, "MA is produced, or 'cooked', quickly, reasonably simply, and cheaply by using legal and readily available ingredients with recipes that can be found on the internet".
Because of the low cost, ready availability and legal status of the drug, long-term use can be a serious problem. In order to assess the risk factors that are associated with people using MA, Klassen and his team carried out an analysis of twelve different medical studies, combining their results to get a bigger picture of the MA problem. They said, "Within the low-risk group, there were some clear patterns of risk factors associated with MA use. A history of engaging in behaviors such as sexual activity, alcohol consumption and smoking was significantly associated with MA use among low-risk youth. Engaging in these kinds of behaviors may be a gateway for MA use or vice versa. A homosexual or bisexual lifestyle is also a risk factor."
Amongst high-risk youth, the risk factors the authors identified were, "growing up in an unstable family environment (e.g., family history of crime, alcohol use and drug use) and having received treatment for psychiatric conditions. Among high-risk youth, being female was also a risk factor".
MA is a stimulant, usually smoked, snorted or injected. It produces sensations of euphoria, lowered inhibitions, feelings of invincibility, increased wakefulness, heightened sexual experiences, and hyperactivity resulting from increased energy for extended periods of time. According to the lead author of this study, Terry P. Klassen of the University of Alberta, Canada, "MA is produced, or 'cooked', quickly, reasonably simply, and cheaply by using legal and readily available ingredients with recipes that can be found on the internet".
Because of the low cost, ready availability and legal status of the drug, long-term use can be a serious problem. In order to assess the risk factors that are associated with people using MA, Klassen and his team carried out an analysis of twelve different medical studies, combining their results to get a bigger picture of the MA problem. They said, "Within the low-risk group, there were some clear patterns of risk factors associated with MA use. A history of engaging in behaviors such as sexual activity, alcohol consumption and smoking was significantly associated with MA use among low-risk youth. Engaging in these kinds of behaviors may be a gateway for MA use or vice versa. A homosexual or bisexual lifestyle is also a risk factor."
Amongst high-risk youth, the risk factors the authors identified were, "growing up in an unstable family environment (e.g., family history of crime, alcohol use and drug use) and having received treatment for psychiatric conditions. Among high-risk youth, being female was also a risk factor".
Most Internet Sex Offenders Aim At Teens
Contrary to stereotype, most Internet sex offenders are not adults who target young children by posing as another youth, luring children to meetings, and then abducting or forcibly raping them, according to researchers who have studied the nature of Internet-initiated sex crimes.
Rather, most online sex offenders are adults who target teens and seduce victims into sexual relationships. They take time to develop the trust and confidence of victims, so that the youth see these relationships as romances or sexual adventures. The youth most vulnerable to online sex offenders have histories of sexual or physical abuse, family problems, and tendencies to take risks both on- and offline, the researchers say.
In short, the researchers draw a clearer picture about adults who troll the Internet for sex with minors in the study, "Online 'Predators' and Their Victims: Myths, Realities and Implications for Prevention," published in the February/March issue of American Psychologist.
The study was based on three surveys--two comprising telephone interviews of a combined 3,000 Internet users between the ages of 10 and 17; first in 2000 and again in 2005; and one involving 612 interviews with federal, state and local law enforcement officials in the United States between October 2001 and July 2002.
"To prevent these crimes, we need accurate information about their true dynamics," said Janis Wolak, lead author of the study. "The things that we hear and fear and the things that actually occur may not be the same. The newness of the environment makes it hard to see where the danger is."
For example, in spite of public concern, the authors found that adolescents' use of popular social networking sites such as MySpace and Facebook do not appear to increase their risk of being victimized by online predators. Rather, it is risky online interactions such as talking online about sex to unknown people that increases vulnerability, according to the researchers.
"Most Internet-initiated sex crimes involve adult men who are open about their interest in sex," Wolak said. "The offenders use instant messages, e-mail and chat rooms to meet and develop intimate relationships with their victims. In most of the cases, the victims are aware that they are talking online with adults."
"A majority of the offenders are charged with crimes such as statutory rape, that involve non-forcible sexual activity with adolescent victims who are too young to consent to sexual intercourse with adults," she added.
Current educational efforts that are focused on discouraging children from giving out or posting personal information, warning about deception online, and urging parents to monitor their children may not be effective, according to the authors.
Wolak and her colleagues say more effort should be directed at helping teens appreciate the drawbacks and inappropriateness of romantic relationships with adults. These efforts should include frank discussions of the dynamics of Internet-initiated sex crimes. Since many of the victims do not have good relationships with parents, ways to reach vulnerable teens directly, through sources they find credible, need to be found.
Among the study's other findings:
Internet offenders pretended to be teenagers in only 5 percent of the crimes studied by researchers.
Nearly 75 percent of victims who met offenders face-to-face did so more than once.
Online sex offenders are seldom violent, and cases involving stalking or abduction are very rare.
Youth who engaged in four or more risky online behaviors were much more likely to report receiving online sexual solicitations. The online risky behaviors included maintaining buddy lists that included strangers, discussing sex online with people they did not know in person and being rude or nasty online.
Boys who are gay or are questioning their sexuality may be more susceptible to Internet-initiated sex crimes than other populations. Researchers found boys were the victims in nearly one-quarter of criminal cases, and most cases included facts that suggested victims were gay or questioning their sexuality.
Journal reference: Online "Predators" and Their Victims: Myths, Realities, and Implications for Prevention and Treatment, Janis Wolak, PhD, David Finkelhor, PhD and Kimberley J. Mitchell, PhD Crimes Against Children Center at the University of New Hampshire and Michelle L. Ybarra, PhD, Internet Solutions for Kids, Inc., American Psychologist, Vol. 63, No.2.
*These studies were conducted by the authors, Janis Wolak, JD, David Finkelhor, PhD, Kimberly Mitchell, PhD and Michele Ybarra, PhD, at the Crimes against Children Research Center, University of New Hampshire.
Rather, most online sex offenders are adults who target teens and seduce victims into sexual relationships. They take time to develop the trust and confidence of victims, so that the youth see these relationships as romances or sexual adventures. The youth most vulnerable to online sex offenders have histories of sexual or physical abuse, family problems, and tendencies to take risks both on- and offline, the researchers say.
In short, the researchers draw a clearer picture about adults who troll the Internet for sex with minors in the study, "Online 'Predators' and Their Victims: Myths, Realities and Implications for Prevention," published in the February/March issue of American Psychologist.
The study was based on three surveys--two comprising telephone interviews of a combined 3,000 Internet users between the ages of 10 and 17; first in 2000 and again in 2005; and one involving 612 interviews with federal, state and local law enforcement officials in the United States between October 2001 and July 2002.
"To prevent these crimes, we need accurate information about their true dynamics," said Janis Wolak, lead author of the study. "The things that we hear and fear and the things that actually occur may not be the same. The newness of the environment makes it hard to see where the danger is."
For example, in spite of public concern, the authors found that adolescents' use of popular social networking sites such as MySpace and Facebook do not appear to increase their risk of being victimized by online predators. Rather, it is risky online interactions such as talking online about sex to unknown people that increases vulnerability, according to the researchers.
"Most Internet-initiated sex crimes involve adult men who are open about their interest in sex," Wolak said. "The offenders use instant messages, e-mail and chat rooms to meet and develop intimate relationships with their victims. In most of the cases, the victims are aware that they are talking online with adults."
"A majority of the offenders are charged with crimes such as statutory rape, that involve non-forcible sexual activity with adolescent victims who are too young to consent to sexual intercourse with adults," she added.
Current educational efforts that are focused on discouraging children from giving out or posting personal information, warning about deception online, and urging parents to monitor their children may not be effective, according to the authors.
Wolak and her colleagues say more effort should be directed at helping teens appreciate the drawbacks and inappropriateness of romantic relationships with adults. These efforts should include frank discussions of the dynamics of Internet-initiated sex crimes. Since many of the victims do not have good relationships with parents, ways to reach vulnerable teens directly, through sources they find credible, need to be found.
Among the study's other findings:
Internet offenders pretended to be teenagers in only 5 percent of the crimes studied by researchers.
Nearly 75 percent of victims who met offenders face-to-face did so more than once.
Online sex offenders are seldom violent, and cases involving stalking or abduction are very rare.
Youth who engaged in four or more risky online behaviors were much more likely to report receiving online sexual solicitations. The online risky behaviors included maintaining buddy lists that included strangers, discussing sex online with people they did not know in person and being rude or nasty online.
Boys who are gay or are questioning their sexuality may be more susceptible to Internet-initiated sex crimes than other populations. Researchers found boys were the victims in nearly one-quarter of criminal cases, and most cases included facts that suggested victims were gay or questioning their sexuality.
Journal reference: Online "Predators" and Their Victims: Myths, Realities, and Implications for Prevention and Treatment, Janis Wolak, PhD, David Finkelhor, PhD and Kimberley J. Mitchell, PhD Crimes Against Children Center at the University of New Hampshire and Michelle L. Ybarra, PhD, Internet Solutions for Kids, Inc., American Psychologist, Vol. 63, No.2.
*These studies were conducted by the authors, Janis Wolak, JD, David Finkelhor, PhD, Kimberly Mitchell, PhD and Michele Ybarra, PhD, at the Crimes against Children Research Center, University of New Hampshire.
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