Intravenous cocaine discrimination in humans.

Ten cocaine-dependent participants were trained to discriminate between intravenous saline and 20 mg/70 kg cocaine. During the first session, saline and cocaine injections were alternated twice, with each separated by 1 hr. The injections were identified by letter codes. During the next 3 sessions, 12 trials were conducted, with saline and cocaine administered 6 times each in pseudorandom order. Thirty minutes following each injection, participants were asked to identify the injection by letter code. Seven of the 10 learned the discrimination (at least 10 trials correct). To evaluate sensitivity, the investigators tested participants with different doses of cocaine in test sessions. In the next phase, methamphetamine (5 and 10 mg/70 kg) and pentobarbital (50 and 100 mg/70 kg) were given intravenously during test sessions to determine whether the discrimination exhibited pharmacological class selectivity. During the evaluation of sensitivity and selectivity, training sessions were interspersed. As dose of cocaine increased, the number of participants identifying the test dose as cocaine increased, demonstrating sensitivity. The higher doses of methamphetamine and pentobarbital substituted for cocaine. The physiological and subjective effects of cocaine and methamphetamine were stimulant-like and dose related. Pentobarbital produced no physiological changes but increased Visual Analog Scale ratings of Sedation, Good Drug Effect, and High. This failure to demonstrate pharmacological selectivity may be related to participants' learning a drug-vs.-no-drug discrimination, and thus it may be necessary to alter training procedures in future studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low complexity Byzantine-resilient consensus

The application of the tolerance paradigm to security - intrusion tolerance - has been raising a reasonable amount of attention in the dependability and security communities. In this paper we present a novel approach to intrusion tolerance. The idea is to use privileged components - generically designated by wormholes - to support the execution of intrusion-tolerant protocols, often called Byzantine-resilient in the literature.The paper introduces the design of wormhole-aware intrusion-tolerant protocols using a classical distributed systems problem: consensus. The system where the consensus protocol runs is mostly asynchronous and can fail in an arbitrary way, except for the wormhole, which is secure and synchronous. Using the wormhole to execute a few critical steps, the protocol manages to have a low time complexity: in the best case, it runs in two rounds, even if some processes are malicious. The protocol also shows how often theoretical partial synchrony assumptions can be substantiated in practical distributed systems. The paper shows the significance of the TTCB as an engineering paradigm, since the protocol manages to be simple when compared with other protocols in the literature.Published online: 29 October 2004This work was partially supported by the EC, through project IST-1999-11583 (MAFTIA), and by the FCT, through the Large-Scale Informatic Systems Laboratory (LASIGE) and projects POSI/1999/CHS/33996 (DEFEATS) and POSI/CHS/39815/2001 (COPE).     

A piezoelectric transducer‐tuned microstrip‐ring resonator oscillator operating at the second resonant mode of the ring resonator

A microstrip open‐loop resonator oscillator operating at even modes is proposed. The even mode of the ring circuit can be predicted by using a simple transmission‐line model. The new oscillator has a characteristic similar to that of a push‐push oscillator. In addition, in comparison with the push‐push oscillator, the new oscillator with one active device can minimize the size and lower the cost. A voltage‐controlled piezoelectric transducer (PET) is used to vary the resonant frequencies of the ring resonator, which in turn tunes the oscillator with a good tuning range of 4.9% at around 12.1 GHz. This tuned oscillator should have many applications in wireless systems. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

Reverse nearest neighbors in large graphs

A reverse nearest neighbor (RNN) query returns the data objects that have a query point as their nearest neighbor (NN). Although such queries have been studied quite extensively in Euclidean spaces, there is no previous work in the context of large graphs. In this paper, we provide a fundamental lemma, which can be used to prune the search space while traversing the graph in search for RNN. Based on it, we develop two RNN methods; an eager algorithm that attempts to prune network nodes as soon as they are visited and a lazy technique that prunes the search space when a data point is discovered. We study retrieval of an arbitrary number k of reverse nearest neighbors, investigate the benefits of materialization, cover several query types, and deal with cases where the queries and the data objects reside on nodes or edges of the graph. The proposed techniques are evaluated in various practical scenarios involving spatial maps, computer networks, and the DBLP coauthorship graph.     

Analytic validation of an infrared milk urea assay and effects of sample acquisition factors on milk urea results

The objective of this study was to determine if milk samples, as they are routinely collected by Ontario Dairy Herd Improvement, would yield accurate milk urea results with an infrared assay. This investigation involved analytic validation of the infrared assay and assessment of the effect of DHI routine sample acquisition factors on milk urea results. Analytic validation of an automated milk urea assay was performed by assessing the relative accuracy and precision of milk urea results produced by the Fossomatic 4000 Milk Analyzer, an infrared method of analysis, compared with the Eurochem test, an accepted reference method. Results indicated that, when interpreted at the group level, milk urea results between the infrared method and the reference test were in good agreement. The two tests shared a similar and high level of precision. Milk urea concentrations obtained from composite (metered) milk samples, and not quarter stripping samples, were most representative of concurrent serum urea concentrations. The addition of bronopol preservative did not result in a numerically important change in milk urea concentrations. Storage of preserved metered milk samples for up to 4 d at either room temperature or by refrigeration, or for up to 3 d by freezing, did not result in changes in milk urea concentrations. We concluded that milk samples, as they are routinely collected and handled by DHI, are suitable for measurement of milk urea concentrations with the infrared method of analysis if data are interpreted at the group level.     

Supercritical CO2 extraction of phthalate plasticizers from PVC

Three common phthalates, namely, dioctyl phthalate, diisodecyl phthalate, and trioctyl trimellitate, were used as plasticizers for poly(vinyl chloride) (PVC) processing, and the extraction of these plasticizers were investigated using supercritical CO₂ fluids. Factors affecting the extractions of these phthalates were focused. The molecular weight of phthalates was found to dominate the level of extraction of low temperatures, whereas the content of carbonyl groups in the phthalate was a determining factor for the level of extraction of high temperatures. Negligible extraction was observed below the critical pressure of CO₂. For 32°C, the level of the extraction is insignificant below density of ca 0.7 g/cm³, above which the level of the extraction increases roughly linearly with increasing density. For temperatures above 32°C, the density of CO₂ for apparent extractions decreased with increasing temperatures. The threshold density of CO₂ for extractions was found to be independent of the amount of a given phthalate in PVC. Two extraction rates during the extraction could be determined, with a higher rate in the first hour followed by a lower rate later in the extraction for all three phthalates. The effects of the extractions of phthalates on the flexibility of PVC were also investigated as well as the effects of the extrusion conditions, which could lead to various degrees of plasticization of PVC, on the level of extractions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4032–4037, 2003     

Reply to Mahrer.

Replies to Mahrer's response (see record 2007-09057-001) to the current author's book review (see record 2007-09053-001). Mahrer raises some important questions and submits that different approaches differ significantly in the categories they use to make sense of what clients do, and that each has its own way of eliciting, listening to and observing what the client says and does. I agree that approaches differ on these features and believe that what we listen for and how we make sense of what we hear is the most fundamental aspect of any therapeutic approach. In fact training in an approach involves not only learning the intervention skills of the approach, which is the easy part, but learning when and how to use the intervention, which is based on listening and process diagnosis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple familiar occurrence of ochronotic arthropathy

Complete papillary muscle rupture is a catastrophic complication of acute myocardial infarction which usually leads to acute severe mitral regurgitation requiring urgent or emergent surgery. A case in which this complication occurred after chordal sparing mitral valve replacement is described. The severed papillary muscle was removed surgically. The incidence and natural history of papillary muscle rupture occurring after chordal sparing mitral valve replacement for ischemic mitral insufficiency is not known.     

Ontario bulk milk somatic cell count reduction program: progress and outlook

The objective of this study was to describe the results of the ongoing somatic cell count (SCC) reduction program in Ontario, Canada and to provide an outlook regarding the possible scenarios beyond the final stages of the current reduction program. The data were from all of the approximately 9500 farms in the province of Ontario during the last 10 yr and included monthly data for kilograms of milk sold, mean milk component measurements, and milk quality measurements (bulk milk SCC, plate loop count, and inhibitor presence). Four of five steps in the control program had a significant impact on the mean monthly bulk milk SCC. The total decrease in mean SCC that was attributable to the program was approximately 80 x 10(3) cells/ml. The monthly occurrence of inhibitor violations increased significantly. Cross-classification of the annual mean bulk milk SCC and the incidence of inhibitor violations indicated that the incidence specifically increased for farms with a relatively high bulk milk SCC. In 1994, bulk milk SCC increased, primarily because of farms that had a mean bulk milk SCC between 150 x 10(3) and 450 x 10(3)/ml. The small relative contribution of farms with higher bulk milk SCC was due to their relatively low production and the small number of farms in those classes. The Ontario SCC reduction program was initially successful in the reduction of mean bulk milk SCC. Further reduction will require the active participation of farms with a relatively low bulk milk SCC. Not only is it necessary to penalize farms that exceed thresholds, but also an incentive to prevent farms with good udder health management from increasing bulk milk SCC is of great importance. The increase in inhibitor violations is of concern and requires further attention.     

Effects of task strain, social conflict, and emotional activation on ambulatory cardiovascular activity: Daily life consequences of recurring stress in a multiethnic adult sample.

Ambulatory blood pressure (ABP) may be an independent predictor of cardiovascular endpoints, but little is known about its psychosocial determinants. The acute effects of psychosocial processes on cardiovascular activity during daily life were examined by random-effects regression. Healthy adults (N?=?120) were monitored over a 6-day period with ABP monitors and computer-assisted self-report assessments. Task strain, social conflict, and emotional activation were rated following each ABP measurement, as were activity, posture, and other covariates. Results show that blood pressure) (BP) and heart rate (HR) were elevated during periods of emotional activation (high negative affect or high arousal). Diastolic BP was lower during periods involving high decisional control, and HR was lower during high-control, low-demand activities. There were substantial individual differences in the effects of psychosocial influences on ambulatory cardiovascular activity. Psychological factors are reliable determinants of ABP, which may account for the unique predictive value of ABP. (PsycINFO Database Record (c) 2010 APA, all rights reserved)