Urgency is a Non-monotonic Function of Pulse Rate

Magnitude estimation was used to assess the experience of urgency in pulse-train stimuli (pulsed white noise) ranging from 3.13 to 200 Hz. At low pulse rates, pulses were easily resolved. At high pulse rates, pulses fused together leading to a tonal sensation with a clear pitch level. Urgency ratings followed a nonmonotonic (polynomial) function with local maxima at 17.68 and 200 Hz. The same stimuli were also used in response time and pitch scaling experiments. Response times were negatively correlated with urgency ratings. Pitch scaling results indicated that urgency of pulse trains is mediated by the perceptual constructs of speed and pitch

The 50 most influential original articles in vascular surgery during the last 25 years

ObjectiveWe have compiled a list of the 50 most-cited original articles in the field of vascular surgery during the last 25 years to highlight the important changes in practice that have occurred during this interval and provide surgical trainees in vascular surgery ready access to such influential articles.MethodsA Web of Knowledge Citation Index Search was performed in December 2013 for the most-cited journal articles in the discipline of vascular surgery. We searched the term “vascular” in the cited reference search area and then further narrowed our results to exclude all categories except “surgery,” “general internal medicine,” and “cardiac/cardiovascular systems.” We included only documents labeled as “articles” and those published in English. Articles dealing with cardiac surgery, interventional cardiology, and cardiovascular biology were excluded. Our search period was from January 1, 1988, through December 3, 2013. The 50 most frequently cited works were chosen, and a citation density was calculated for each, reflecting the average number of citations each received per year since publication. The articles were then sorted into a defined category, based on the clinical subject to which they pertained.ResultsThe Citation Index Search resulted 80,379 articles, of which the top 50 were indexed and organized according to their citation density and area within the scope of clinical vascular surgery. The number of citations ranged from 218 to 3593. The median citation density was 50.2 (range, 11.3-201.3).ConclusionsThis report is a representation of the most-cited original publications in the field of clinical vascular surgery during the last 25 years. This is an effort to highlight the seminal works that have shaped the discipline of vascular surgery as well as to provide a concise reference list for the surgical trainee in the process of his or her education

The influence of colloidal organic matter on iron and iron‐phosphorus cycling in an acid bog lake

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109933/1/lno19762150684.pd

George’s Island, Labrador - A high-density predator-free refuge for a woodland caribou subpopulation?

The movement patterns and demographic parameters were measured for caribou (Rangifer tarandus caribou) on George’s Island (Labrador, Canada) to determine if the population is separate from the Mealy Mountain Caribou Herd. Movements between George’s Island caribou and nearby Mealy Mountain caribou were examined through satellite telemetry (April 2005 to April 2006). Demographic information was collected through aerial classification surveys. The predator-free island is currently maintaining a density of 22.5-26.5 caribou/km2. Female survival appears high and the recruitment rate in late fall-early spring was 19.0-29.2% calves. Mainland caribou moved very little throughout the year, travelling no more than 53.7 km on average from their initial collaring locations. Also, satellite data indicated no mixing between animals on George’s Island and the mainland. The elevated caribou density and high proportion of calves suggest that George’s Island could at times be acting as a predator-free recruitment area and that George’s Island may be a subpopulation from which animals disperse to the mainland

Relative Emergence of Weeds and Corn and Soybean

The success of integrated weed management relies on matching control strategies to the specific weed problem in a field. This requires information not only on what weed species and how many of these weeds are present in a field, but also knowledge of the distribution of the weeds throughout the field and the stage of development of these weeds. Weed control recommendations typically provide information on appropriate tillage methods and herbicide selection. The information concerning weed infestations used to base these recommendations typically is not of sufficient detail to optimize the efficiency of these strategies. Information on weed populations can be improved by increasing the time spent scouting fields. However, time restraints during the busy spring season restrict this opportunity. This problem could be alleviated with an improved understanding of the environmental influences on weed emergence and growth, therefore allowing us to predict when best to invest time in scouting. Armed with greater knowledge of weed development and populations, a person could determine the optimum time for tillage and crop planting to reduce weed populations, maximizing the effectiveness of mechanical weed control operations, and for timing of burndown and postemergence herbicide applications. Although there has been considerable research and modeling of weed emergence in recent years, little effort has been directed toward development of emergence information for persons involved in weed management. This paper provides information on how weed emergence timing influences weed management systems. Included are preliminary rankings of relative emergence for important weed species in the Midwest. The Leopold Center for Sustainable Agriculture is supporting efforts to develop more precise emergence indices that will be of greater benefit in aiding the development of more efficient weed management systems

Erosion Remineralization Efficacy of Gel-to-Foam Fluoride Toothpastes in situ: A Randomized Clinical Trial

This single-center, randomized, placebo-controlled, four-treatment, four-period crossover study compared the enamel remineralization effects of low- and medium-abrasivity gel-to-foam toothpastes and a reference toothpaste (all 1,450 ppm fluoride as NaF) versus placebo toothpaste (0 ppm fluoride) using a short-term in situ erosion model. Subjects (n = 56) wearing a palatal appliance holding acid-softened bovine enamel specimens brushed their teeth with the test toothpastes. Thereafter, the specimens were removed for analysis of percent surface microhardness recovery (%SMHR) and percent relative erosion resistance (%RER) at 2, 4, and 8 h. Both low- and medium-abrasivity gel-to-foam fluoride toothpastes and the reference toothpaste provided significantly greater %SMHR than placebo at all assessment time points (all p < 0.05). No statistically significant difference of %SMHR was observed between the fluoride treatment groups at any time point. Similarly, all fluoride products provided significantly superior %RER versus placebo (all p < 0.0001), whereas no significant difference of this parameter was noted between the fluoride treatment groups. Increasing numerical improvements of %SMHR and %RER were observed in all four treatment groups over time (2, 4, and 8 h). The present in situ model is a sensitive tool to investigate intrinsic and fluoride-enhanced rehardening of eroded enamel. All three fluoride toothpastes were more efficacious than placebo, and there were no safety concerns following single dosing in this short-term in situ model

Recent Decisions

Admiralty--Workmen\u27s Compensation--Receipt of Benefits under State Workmen\u27s Compensation Act containing Exclusive Remedy Provision does not Bar Subsequent Action against Employer for Unseaworthiness Patricia D. Owen ====================== Common Market--Council Regulations--Regulation Stake Precedence over Provisions of Member States\u27 Constitutions Jeffery R. Rush ===================== Discovery--Aid to Foreign or International Tribunals--United States Courts can Compel Testimony only on Behalf of Foreign or International Tribunals Empowered to make Binding Adjudications Frank R. Krok ===================== Extradition--Statute of Limitations--mere Absence is not Equivalent to Fleeing from Justice under 18 U.S.C. § 3290 Paul P. Sanford ===================== International Court of Justice--Procedure Temporary Relief in the Form of Interim Measures Granted on Prima Facie Evidence of Jurisdiction and Jurisdiction of the Merits Found on Basis of Prior Agreement to Compulsory I.C.J. Jurisdiction Edward N. Perry ==================== Jurisdiction--NATO--North Atlantic Treaty Organization status of Forces Agreement not an Exclusive Remedy for Member of United States Force or Civilian Component Edward A. Betancour

Small-molecule modulators of Hedgehog signaling: identification and characterization of Smoothened agonists and antagonists

BACKGROUND: The Hedgehog (Hh) signaling pathway is vital to animal development as it mediates the differentiation of multiple cell types during embryogenesis. In adults, Hh signaling can be activated to facilitate tissue maintenance and repair. Moreover, stimulation of the Hh pathway has shown therapeutic efficacy in models of neuropathy. The underlying mechanisms of Hh signal transduction remain obscure, however: little is known about the communication between the pathway suppressor Patched (Ptc), a multipass transmembrane protein that directly binds Hh, and the pathway activator Smoothened (Smo), a protein that is related to G-protein-coupled receptors and is capable of constitutive activation in the absence of Ptc. RESULTS: We have identified and characterized a synthetic non-peptidyl small molecule, Hh-Ag, that acts as an agonist of the Hh pathway. This Hh agonist promotes cell-type-specific proliferation and concentration-dependent differentiation in vitro, while in utero it rescues aspects of the Hh-signaling defect in Sonic hedgehog-null, but not Smo-null, mouse embryos. Biochemical studies with Hh-Ag, the Hh-signaling antagonist cyclopamine, and a novel Hh-signaling inhibitor Cur61414, reveal that the action of all these compounds is independent of Hh-protein ligand and of the Hh receptor Ptc, as each binds directly to Smo. CONCLUSIONS: Smo can have its activity modulated directly by synthetic small molecules. These studies raise the possibility that Hh signaling may be regulated by endogenous small molecules in vivo and provide potent compounds with which to test the therapeutic value of activating the Hh-signaling pathway in the treatment of traumatic and chronic degenerative conditions