Elevated arousal at time of decision-making is not the arbiter of risk avoidance in chickens

The somatic marker hypothesis proposes that humans recall previously experienced physiological responses to aid decision-making under uncertainty. However, little is known about the mechanisms used by non-human animals to integrate risk perception with predicted gains and losses. We monitored the behaviour and physiology of chickens when the choice between a high-gain (large food quantity), high-risk (1 in 4 probability of receiving an air-puff) option (HGRAP) or a low-gain (small food quantity), no-risk (of an air-puff) (LGNAP) option. We assessed when arousal increased by considering different stages of the decision-making process (baseline, viewing, anticipation, reward periods) and investigated whether autonomic responses influenced choice outcome both immediately and in the subsequent trial. Chickens were faster to choose and their heart-rate significantly increased between the viewing and anticipation (post-decision, pre-outcome) periods when selecting the HGRAP option. This suggests that they responded physiologically to the impending risk. Additionally, arousal was greater following a HGRAP choice that resulted in an air-puff, but this did not deter chickens from subsequently choosing HGRAP. In contrast to human studies, we did not find evidence that somatic markers were activated during the viewing period, suggesting that arousal is not a good measure of avoidance in non-human animals

Under pressure: Response urgency modulates striatal and insula activity during decision-making under risk

When deciding whether to bet in situations that involve potential monetary loss or gain (mixed gambles), a subjective sense of pressure can influence the evaluation of the expected utility associated with each choice option. Here, we explored how gambling decisions, their psychophysiological and neural counterparts are modulated by an induced sense of urgency to respond. Urgency influenced decision times and evoked heart rate responses, interacting with the expected value of each gamble. Using functional MRI, we observed that this interaction was associated with changes in the activity of the striatum, a critical region for both reward and choice selection, and within the insula, a region implicated as the substrate of affective feelings arising from interoceptive signals which influence motivational behavior. Our findings bridge current psychophysiological and neurobiological models of value representation and action-programming, identifying the striatum and insular cortex as the key substrates of decision-making under risk and urgency

BindN+ for accurate prediction of DNA and RNA-binding residues from protein sequence features

Abstract Background Understanding how biomolecules interact is a major task of systems biology. To model protein-nucleic acid interactions, it is important to identify the DNA or RNA-binding residues in proteins. Protein sequence features, including the biochemical property of amino acids and evolutionary information in terms of position-specific scoring matrix (PSSM), have been used for DNA or RNA-binding site prediction. However, PSSM is rather designed for PSI-BLAST searches, and it may not contain all the evolutionary information for modelling DNA or RNA-binding sites in protein sequences. Results In the present study, several new descriptors of evolutionary information have been developed and evaluated for sequence-based prediction of DNA and RNA-binding residues using support vector machines (SVMs). The new descriptors were shown to improve classifier performance. Interestingly, the best classifiers were obtained by combining the new descriptors and PSSM, suggesting that they captured different aspects of evolutionary information for DNA and RNA-binding site prediction. The SVM classifiers achieved 77.3% sensitivity and 79.3% specificity for prediction of DNA-binding residues, and 71.6% sensitivity and 78.7% specificity for RNA-binding site prediction. Conclusions Predictions at this level of accuracy may provide useful information for modelling protein-nucleic acid interactions in systems biology studies. We have thus developed a web-based tool called BindN+ (http://bioinfo.ggc.org/bindn+/) to make the SVM classifiers accessible to the research community

Graduates of Lebanese medical schools in the United States: an observational study of international migration of physicians

BACKGROUND: As healthcare systems around the world are facing increasing physician shortages, more physicians are migrating from low to high income countries. As an illustrative case of international migration of physicians, we evaluated the current number and historical trends of Lebanese medical graduates (LMG) in the US, and compared their characteristics to those of US medical graduates (USMG) and other international medical graduates (IMG). METHODS: We evaluated the number of LMG using the 2004 the American Medical Association Physicians' Professional Data (AMA-PPD) and then compared it to the number of graduates of other countries. We evaluated the historical trends using the 1978–2004 historical files of the AMA-PPD. We analyzed the characteristics of all LMG and compared them to a random sample of 1000 USMG and a random sample of 1000 IMG using the 2004 AMA-PPD. RESULTS: In 2004, there were 2,796 LMG in the US, constituting 1.3% of all IMG. Compared to other foreign countries contributing to the US physician workforce, Lebanon ranked 2nd after adjusting for country population size (about 4 million) and 21st overall. About 40% of those who graduated from Lebanese medical schools in the last 25 years are currently active physicians in the US. Since 1978, the number of LMG in the US showed a consistent upward trend at a rate of approximately 71 additional graduates per year. Compared with USMG and IMG, LMG were more likely to work in medical research (OR = 2.31; 95% Confidence Interval (CI) = 1.21; 4.43 and OR = 2.63; 95% CI = 1.34; 5.01, respectively) and to be board certified (OR = 1.43; 95% CI = 1.14; 1.78 and OR = 2.04; 95% CI = 1.65;2.53, respectively) and less likely to be in family practice (OR = 0.14; 95% CI = 0.10; 0.19 and OR = 0.18; 95% CI = 0.12; 0.26, respectively). CONCLUSION: Given the magnitude and historical trends of migration of LMG to the US, further exploration of its causes and impact is warranted. High income countries should consider the consequences of their human resources policies on both low income countries' and their own healthcare systems

Epiploic appendagitis – clinical characteristics of an uncommon surgical diagnosis

<p>Abstract</p> <p>Background</p> <p>Epiploic appendagitis (EA) is a rare cause of focal abdominal pain in otherwise healthy patients with mild or absent secondary signs of abdominal pathology. It can mimick diverticulitis or appendicitis on clinical exam. The diagnosis of EA is very infrequent, due in part to low or absent awareness among general surgeons. The objective of this work was to review the authors' experience and describe the clinical presentation of EA.</p> <p>Methods</p> <p>All patients diagnosed with EA between January 2004 and December 2006 at an urban surgical emergency room were retrospectively reviewed by two authors in order to share the authors' experience with this rare diagnosis. The operations were performed by two surgeons. Pathological examinations of specimens were performed by a single pathologist. A review of clinical presentation is additionally undertaken.</p> <p>Results</p> <p>Ten patients (3 females and 7 males, average age: 44.6 years, range: 27–76 years) were diagnosed with symptomatic EA. Abdominal pain was the leading symptom, the pain being localized in the left (8 patients, 80 %) and right (2 patients, 20%) lower quadrant. All patients were afebrile, and with the exception of one patient, nausea, vomiting, and diarrhea were not present. CRP was slightly increased (mean: 1.2 mg/DL) in three patients (33%). Computed tomography findings specific for EA were present in five patients. Treatment was laparoscopic excision (n = 8), excision via conventional laparotomy (n = 1) and conservative therapy (n = 1).</p> <p>Conclusion</p> <p>In patients with localized, sharp, acute abdominal pain not associated with other symptoms such as nausea, vomiting, fever or atypical laboratory values, the diagnosis of EA should be considered. Although infrequent up to date, with the increase of primary abdominal CT scans and ultrasound EA may well be diagnosed more frequently in the future.</p

To Fear is to Gain? The Role of Fear Recognition in Risky Decision Making in TBI Patients and Healthy Controls

Fear is an important emotional reaction that guides decision making in situations of ambiguity or uncertainty. Both recognition of facial expressions of fear and decision making ability can be impaired after traumatic brain injury (TBI), in particular when the frontal lobe is damaged. So far, it has not been investigated how recognition of fear influences risk behavior in healthy subjects and TBI patients. The ability to recognize fear is thought to be related to the ability to experience fear and to use it as a warning signal to guide decision making. We hypothesized that a better ability to recognize fear would be related to a better regulation of risk behavior, with healthy controls outperforming TBI patients. To investigate this, 59 healthy subjects and 49 TBI patients were assessed with a test for emotion recognition (Facial Expression of Emotion: Stimuli and Tests) and a gambling task (Iowa Gambling Task (IGT)). The results showed that, regardless of post traumatic amnesia duration or the presence of frontal lesions, patients were more impaired than healthy controls on both fear recognition and decision making. In both groups, a significant relationship was found between better fear recognition, the development of an advantageous strategy across the IGT and less risk behavior in the last blocks of the IGT. Educational level moderated this relationship in the final block of the IGT. This study has important clinical implications, indicating that impaired decision making and risk behavior after TBI can be preceded by deficits in the processing of fear

Prefrontal Norepinephrine Determines Attribution of “High” Motivational Salience

Intense motivational salience attribution is considered to have a major role in the development of different psychopathologies. Numerous brain areas are involved in “normal” motivational salience attribution processes; however, it is not clear whether common or different neural mechanisms also underlie intense motivational salience attribution. To elucidate this a brain area and a neural system had to be envisaged that were involved only in motivational salience attribution to highly salient stimuli. Using intracerebral microdialysis, we found that natural stimuli induced an increase in norepinephrine release in the medial prefrontal cortex of mice proportional to their salience, and that selective prefrontal norepinephrine depletion abolished the increase of norepinephrine release in the medial prefrontal cortex induced by exposure to appetitive (palatable food) or aversive (light) stimuli independently of salience. However, selective norepinephrine depletion in the medial prefrontal cortex impaired the place conditioning induced exclusively by highly salient stimuli, thus indicating that prefrontal noradrenergic transmission determines approach or avoidance responses to both reward- and aversion-related natural stimuli only when the salience of the unconditioned natural stimulus is high enough to induce sustained norepinephrine outflow. This affirms that prefrontal noradrenergic transmission determines motivational salience attribution selectively when intense motivational salience is processed, as in conditions that characterize psychopathological outcomes