Mica: a wireless platform for deeply embedded networks

Low-power integration of sensing, communication, and computation requires a new approach to wireless design. Flexible interfaces and primitive accelerators enable aggressive system-level optimizations. Mica's flexible design serves as a building block for creating efficient application-specific protocols. Instead of defining narrow, standardized application interfaces, Mica provides a set of richly interconnected primitives (such as data serializers and timing extractors) to facilitate cross-layer optimizations. To explore novel systems approaches, researchers can develop customized protocols tailored to their application; Mica does not require use of predefined protocols.     

Hospital resource consumption among older adults: a prospective analysis of episodes, length of stay, and charges over a seven-year period

After linking their administrative records and interview data, the consumption of Medicare-reimbursed hospital resources during 1984 through 1990 by the 7,527 LSOA respondents was prospectively assessed using a two-part design. First, logistic regression was used to model whether a hospital episode occurred. Second, among those having had hospital episodes, OLS regression was used to model the number of episodes, as well as the natural logarithms of the total length of stay and the total charges. The risk of hospitalization was mostly associated with being male, prior hospital and physician utilization, and lower body limitations. Among those hospitalized: (a) greater numbers of episodes were mostly associated with prior hospital and physician utilization, and poorer perceived health; (b) longer lengths of stay were mostly associated with prior hospital and physician utilization, and poorer perceived health; and, (c) higher charges were mostly associated with population density, poorer perceived health, and prior physician and hospital utilization. Decedents consistently consumed substantially more hospital resources than survivors.     

A case for NOW (Networks of Workstations)

Networks of workstations are poised to become the primary computing infrastructure for science and engineering. NOWs may dramatically improve virtual memory and file system performance; achieve cheap, highly available, and scalable file storage: and provide multiple CPUs for parallel computing. Hurdles that remain include efficient communication hardware and software, global coordination of multiple workstation operating systems, and enterprise-scale network file systems. Our 100-node NOW prototype aims to demonstrate practical solutions to these challenges     

Mastitis: I. In vitro antimicrobial activity of alkyl amines against mastitic bacteria.

The activities of branched and straight chain amines (10 to 18 carbons chain length) were compared in inhibiting the growth of five microorganisms that cause about 95% of bovine mastitis. Three gram-positive (Streptococcus agalactiae, Streptococcus uberis, Staphylococcus aureus) and two gram-negative (Escherichia coli, Klebsiella pneumoniae) bacteria were used in a trypticase soy broth tube culture growth assay. Sixty-two compounds were screened at concentrations of 200, 100, 50, 25, 10, 5, and 1 ppm in broth culture to determine the effective minimum inhibitory concentration. Alkyl secondary N-substituted monoethyl [CH3(CH2)nNHCH2CH3] and tertiary N,N-substituted dimethyl [CH3(CH2) nN(CH3)2] amines with chain lengths of 11 to 14 carbon atoms were active against both gram-positive and gram-negative organisms. Antimicrobial activity against gram-positive organisms increased with increasing chain length and carbon-14 to 18 amines were active at 1 to 5 ppm. The carbon-11 to 13 alkyl amines were most active against gram-positive organisms; longer chain amines (more than 14 carbons) were inactive. Branching of the alkyl chain caused a loss of activity against gram-negative but not against gram-positive bacteria. Antimicrobial testing of monoamines, polyamines, and the influence of order substituents were investigated to correlate structure-acitivity relationships.     

Test anxiety and academic performance: The effects of study-related behaviors.

Investigated (a) the relationship of test anxiety to academic performance in college students, (b) differences in study-related behaviors between high and low test-anxious Ss, and (c) differential effectiveness of study-related behaviors for both groups. Undergraduate Ss were 65 high and 31 low scorers on the Test Anxiety Scale. Results demonstrate a significant decrement in GPA associated with test anxiety. High test-anxious Ss were also found to have poorer study skills. For high test-anxious Ss, quality of study habits and amount of study time were positively related to academic performance, whereas missing classes and delaying exams were inversely related to performance. Findings are discussed in terms of the prevailing interference model of test anxiety. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adamantyl ethanone pyridyl derivatives: potent and selective inhibitors of human 11β-hydroxysteroid dehydrogenase type 1

Elevated levels of active glucocorticoids have been implicated in the development of several phenotypes of metabolic syndrome, such as type 2 diabetes and obesity. 11β‐Hydroxysteroid dehydrogenase type 1 (11β‐HSD1) catalyses the intracellular conversion of inactive cortisone to cortisol. Selective 11β‐HSD1 inhibitors have shown beneficial effects in various conditions, including diabetes, dyslipidemia and obesity. A series of adamantyl ethanone pyridyl derivatives has been identified, providing potent and selective inhibitors of human 11β‐HSD1. Lead compounds display low nanomolar inhibition against human and mouse 11β‐HSD1 and are selective for this isoform, with no activity against 11β‐HSD2 and 17β‐HSD1. Structure–activity relationship studies reveal that an unsubstituted pyridine tethered to an adamantyl ethanone motif through an ether or sulfoxide linker provides a suitable pharmacophore for activity. The most potent inhibitors have IC₅₀ values around 34–48 nM against human 11β‐HSD1, display reasonable metabolic stability in human liver microsomes, and weak inhibition of key human CYP450 enzymes.     

Assessing fast network interfaces

Assessing the performance of emerging high-speed networks is difficult. Our communication microbenchmark evaluates design changes in a communications system. Our microbenchmark generates a graphical signature from which we extract communication performance parameters for the hardware-software tandem. We use the LogP conceptual model for communication systems. (LogP stands for the parameters latency, overhead, gap, and processors). We study three important platforms that represent diverse points in the network interface design space: the Intel Paragon, Meiko CS-2, and a cluster of Sparcstation-20s connected by Myrinet switches using LANai SBus cards. Our study views each machine as a gray box supporting Active Messages and conforming to the LogP framework. We devise a simple set of communication microbenchmarks and measure the performance on each platform to obtain the LogP parameters     

Chemical and sensory characterization of oxidative behavior in different wines

In wine making, the redox phenomena are responsible for profound changes in the wine’s chemical composition. Twenty wines set has been selected trying to cover a wide range of behaviors against to oxidation–reduction phenomenon. Free SO₂ level was adjusted to the maximum level found to avoid its influence from the wine oxidative trend. Samples of this set of wines were submitted to extreme conditions during 1 month. Samples were taken in different days for sensorial and chemical analysis. It is proved that red wines oxidation velocity is much higher than white wines. Aldehydes were quantified by gas chromatography–negative ion mass spectrometry (GC–NCI–MS) using a previous derivatization procedure. In conclusion, it can be said that the speed at which the sensory characteristics of wine changes are loosely related to the production of relevant odor active aldehydes, particularly to levels of methional and phenylacetaldehyde. In general, red wines produce those aldehydes during oxidation at a much higher speed than white wines, which is in agreement with the observed changes in sensory properties. However, it was not possible to find good correlations between sensory changes and aldehyde production within the red or white subsets.     

An analysis of VI Architecture primitives in support of parallel and distributed communication

We present the results of a detailed study of the Virtual Interface (VI) paradigm as a communication foundation for a distributed computing environment. Using Active Messages and the Split‐C global memory model, we analyze the inherent costs of using VI primitives to implement these high‐level communication abstractions. We demonstrate a minimum mapping cost (i.e. the host processing required to map one abstraction to a lower abstraction) of 5.4 μs for both Active Messages and Split‐C using four‐way 550 MHz Pentium III SMPs and the Myrinet network. We break down this cost to the use of individual VI primitives in supporting flow control, buffer management and event processing and identify the completion queue as the source of the highest overhead. Bulk transfer performance plateaus at 44 Mbytes/s for both implementations are due to the addition of fragmentation requirements. Based on this analysis, we present the implications for the VI successor, Infiniband. Copyright © 2002 John Wiley & Sons, Ltd.