203 research outputs found
Federal Pre-emption: Time to Reestablish an Old Doctrine
State tort claims have traditionally been decided in state courts using state law and without federal interference
Keeping the baby when we throw out the bathwater: social supermarkets for community development
Attraction pheromone of the benthic diatom Seminavis robusta : studies on structure-activity relationships
Recently the first pheromone of a marine diatom was identified to be the diketopiperazine (S,S)-diproline. This compound facilitates attraction between mating partners in the benthic diatom Seminavis robusta. Interestingly, sexualized S. robusta cells are attracted to both the natural pheromone (S,S)-diproline as well as to its enantiomer (R,R)-diproline. Usually stereospecificity is a prerequisite for successful substrate-receptor interactions, and especially pheromone perception is often highly enantioselective. Here we introduce a structure-activity relationship study, to learn more about the principles of pheromone reception in diatoms. We analyzed the activity of nine different diketopiperazines in attraction and interference assays. The pheromone diproline itself, as well as a pipecolic acid derived diketopiperazine with two expanded aliphatic ring systems, showed the highest attractivity. Hydroxylatoin of the aliphatic rings abolished any bioactivity. Diketopiperazines derived from acyclic amino acids were not attrative as well. All stereoisomers of both the diproline and the pipecolic acid derived diketopiperazine were purified by enantioselective high-performance liquid chromatography, and application in bioactivity tests confirmed that attraction pheromone perception in this diatom is indeed not stereospecific. However, the lack of activity of diketopiperazines derived from acyclic amino acids suggests a specificity that prevents misguidance to sources of other naturally occurring diketopiperazines
Iron is not everything: unexpected complex metabolic responses between iron-cycling microorganisms
Who Receives Outpatient Monitoring During High-Risk Depression Treatment Periods?
To examine the intensity of monitoring received by important patient subgroups during high-risk periods (the 12 weeks after psychiatric hospitalization and after new antidepressant starts).Retrospective secondary analysis of data from the Veterans Affairs (VA) National Registry for Depression using patients aged 65 and older receiving depression treatment from 1999 to 2004.VA healthcare system.VA patients in depression treatment between April 1, 1999, and September 30, 2004, who had psychiatric inpatient stays (n=73,137) or new antidepressant starts (n=421,536).The relationship between the number of outpatient visits for each group and patient characteristics in the 12-week period after psychiatric hospitalizations and antidepressant starts.The characteristic associated with significantly lower rates of monitoring for both high-risk treatment periods was aged 65 and older. White race and living in the south or northeast were also associated with significantly lower rates of monitoring after new antidepressant starts and inpatient stays, respectively. Substance abuse disorders were associated with greater monitoring after both types of depression events but did not seem to interact with other patient characteristics in determining levels of monitoring.VA patients who are older, white, and living in the south or northeast receive less-intensive monitoring during high-risk treatment periods for suicide. This is of concern, given that older patients appear to be at higher risk for suicide, particularly after inpatient stays, and may need particular attention during this time frame. Adapted interventions and proactive outreach may be needed that target this patient group.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79052/1/j.1532-5415.2010.02810.x.pd
Examining the Relationship between Clinical Monitoring and Suicide Risk among Patients with Depression: Matched Case–Control Study and Instrumental Variable Approaches
To assess the relationship between closer monitoring of depressed patients during high-risk treatment periods and death from suicide, using two analytic approaches.VA patients receiving depression treatment between 1999 and 2004.First, a case–control design was used, adjusting for age, gender, and high-risk days (1,032 cases and 2,058 controls). Second, an instrumental variable (IV) approach ( N =714,106) was used, with IVs of (1) average monitoring rates in the VA facility of most use and (2) monitoring rates of VA facilities weighted inversely by distance from patients' residences.The case–control approach indicated a modest increase in suicide risk with each additional visit (odds ratio=1.02; 95 percent confidence interval=1.002, 1.04). The “facility used” IV estimate indicated near zero change in risk (0.0008 percent increase; p =.97) with each additional visit, while the distance-weighted IV estimate indicated a 0.032 percent decrease in risk ( p =.29). An alternative analysis assuming a threshold effect of ≥4 visits during high-risk periods also showed a decrease (0.15 percent; p =.08) using the distance IV.The IV approach appeared to address the selection bias more appropriately than the case–control analysis. Neither analysis clearly indicated that closer monitoring during high-risk periods was significantly associated with reduced suicide risks, but the distance-weighted IV estimate suggested a potentially protective effect.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79285/1/j.1475-6773.2010.01132.x.pd
New solutions to old problems? Appraising the prospects for a social supermarket in South West Glasgow
Ultra high performance liquid chromatography–tandem mass spectrometry method for cyclosporine a quantification in biological samples and lipid nanosystems
- …