cssi/SciSciGPT-SciSciNet huggingface dataset:
Crystallization and preliminary X-ray analysis of a U2AF65 variant in complex with a polypyrimidine-tract analogue by use of protein engineering.

The large subunit of the essential pre-mRNA splicing factor U2 auxiliary factor (U2AF65) binds the polypyrimidine tract near the 3′ splice site of pre-mRNA introns and directs the association of the U2 small nuclear ribonucleoprotein particle (U2 snRNP) of the spliceosome with the pre-mRNA. Protein engineering, in which the flexible linker region connecting tandem RNA-recognition motifs (RRMs) within the U2AF65 RNA-binding domain was partially deleted, allowed successful crystallization of the protein–nucleic acid complex. Cocrystals of a U2AF65 variant with a deoxyuridine dodecamer diffract X-rays to 2.9 A resolution and contain one complex per asymmetric unit.
Fire resistance of tree species explains historical gallery forest community composition

Abstract Fire, climatic variability, and grazing by large herbivores have historically limited woody vegetation in the tallgrass prairie region of North America to gallery forests in protected areas along rivers and streams. Fire, in particular, has been a strong selective pressure against woody vegetation. Consequently, we expect that dominant tree species in these forests have developed mechanisms for tolerating periodic surface fires. Susceptibility of trees to fire damage depends in part on key properties of bark which influence heat transfer to the vascular cambium, including thickness, density, and moisture content. An historical (1983) survey of Konza Prairie Biological Station in northeast Kansas, USA indicated that gallery forests were co-dominated by Quercus macrocarpa and Quercus muehlenbergii, while Celtis occidentalis occurred as an important sub-dominant species. Populus deltoides, Gleditsia triacanthos, and Juniperus virginiana were relatively uncommon. To test the hypothesis that historically dominant gallery forest tree species are more resistant to fire damage than uncommon species, fire was applied to the bark of 10 individuals of each of these six species under conditions mimicking surface fires (400 °C for 120 s). Maximum temperature at the vascular cambium, bark thickness, bark moisture content, and bark density were measured. Trees were considered fire-resistant if the vascular cambium temperature remained below the thermal cell death threshold, 60 °C, throughout the treatment. Using logistic regression, bark thickness was found to be a significant predictor of lethal cambium temperatures (P = 0.002), while neither bark density nor moisture content were significantly related to lethal cambium temperature (P = 0.279 and P = 0.131, respectively). Across species, a minimum bark thickness of approximately 8.6 mm was necessary to maintain the vascular cambium temperature below 60 °C. Trees that produce thick bark quickly in juvenile size classes (P. deltoides, Q. macrocarpa, and Q. muehlenbergii) experienced lower temperatures at the vascular cambium than those which do not develop thick bark with increasing diameter (C. occidentalis, G. triacanthos, and J. virginiana). Ranking these tree species by either the DBH or age needed to develop the minimum protective bark thickness largely agreed with ranking based on historical relative importance. As fire frequency and intensity decrease in remnant tallgrass prairie of North America as a result of habitat fragmentation, fire suppression, and changing land management, fire-sensitive species may increase in relative importance in gallery forests because of increased juvenile survival.
Low-Order Stochastic Mode Reduction for a Realistic Barotropic Model Climate

Abstract This study applies a systematic strategy for stochastic modeling of atmospheric low-frequency variability to a realistic barotropic model climate. This barotropic model climate has reasonable approximations of the Arctic Oscillation (AO) and Pacific/North America (PNA) teleconnections as its two leading principal patterns of low-frequency variability. The systematic strategy consists first of the identification of slowly evolving climate modes and faster evolving nonclimate modes by use of an empirical orthogonal function (EOF) decomposition. The low-order stochastic climate model predicts the evolution of these climate modes a priori without any regression fitting of the resolved modes. The systematic stochastic mode reduction strategy determines all correction terms and noises with minimal regression fitting of the variances and correlation times of the unresolved modes. These correction terms and noises account for the neglected interactions between the resolved climate modes and the unresolve...
An efficient and highly stereocontrolled route to bulgecinine hydrochloride.

(−)-Bulgecinine is a nonproteinogenic amino acid component present in bulgecins A, B, and C, antibiotic glycopeptides derived from Pseudomonas acidophila and Pseudomonas mesoacidophila. In combination with β-lactam antibiotics, bulgecins exihibit a unique synergistic antibacterial activity against various Gram-negative microorganisms. Utilizing d-serine as a chiral template and employing a highly regio- and stereoselective intramolecular amidomercuration-oxidation protocol in the key pyrrolidine ring forming step, an efficient total synthetic route to enantiopure bulgecinine is reported herein.
Electric Trapping and Lysing of Cells in a Microchannel Constriction

Cell lysis is a necessary step in the analysis of intracellular contents. It has been recently demonstrated in microfluidic devices using four methods: chemical lysis, mechanical lysis, thermal lysis, and electrical lysis [1]. The locally high electric fields needed for electrical lysis have been achieved using micro-electrodes and micro-constrictions for pulsed and continuous DC electric fields, respectively. However, since the two determining factors of electrical lysis are field strength and exposure time, opposing pressure-driven flow must often be used in pure DC lysis to reduce the velocity of the cells and to ensure the cells spend sufficient time in the high electric field region [1,2]. Using DC-biased AC fields can easily fulfill these requirements as only the DC component contributes to cell electrokinetic transport. Prior to lysis, cell concentration can be increased by trapping using dielectrophoresis (DEP), which may occur with either DC or DC-biased AC electric fields [3,4]. This operation is useful in cases where the cell supply is limited or when the cell concentration is too low in general. In this work, red blood cells are used to demonstrate the smooth switching between electrical lysing and trapping in a microchannel constriction. The transition between lysis and trapping is realized by tuning the DC component in a DC-biased AC electric field.Copyright © 2009 by ASME
Software Integration without Integrated Software

Every librarian dreams of a full‐function, integrated library automation system arriving in a neatly packaged, turnkey system from a single vendor who will cordially support all of the local library's unique requirements. It should be no surprise that such a system is not available at any price for any size computer—not on a mainframe, minicomputer, or a microcomputer. However, microcomputer users with a do‐it‐yourself bent may find that they can “integrate” available systems using existing building blocks and techniques to link two or more systems to accomplish a task.
Parents as Intervention Agents for Children with Conduct Problems and Juvenile Offenders

Selected research findings on conduct problems and juvenile delinquency that are relevant for practitioners making decisions about the treatment of children with these problems are summarized, with a focus on two decisions: whether to intervene and how to intervene using parents as change agents. The importance of careful assessment, not only of the child's behavior, but also of the parents' strengths and limitations is stressed, along with the importance of flexibility in treatment rather than strict adherence to one theoretical model. Important considerations in assessment and treatment are discussed.
Oxygen may reduce dyspnoea in people with COPD who have mild or no hypoxaemia.

Commentary on: H Uronis, DC McCrory, G Samsa, et al.. Symptomatic oxygen for non-hypoxaemic chronic obstructive pulmonary disease. Cochrane Database Syst Rev2011;6:CD006429.
Electric Silver Antisepsis

Use of silver as a topical antimicrobial agent has been hampered by the absence of a method of providing sustained delivery of the silver ions. One possible solution is the use of silver-coated fabrics as both wound dressings and silver-ion emitting anodes in a simple electric circuit. The antimicrobial dose would then be determined by Faraday's law. In the biological environment, silver-coated materials studied thus far have not behaved as predicted. We have discovered a silver-coated fabric, designated IT, that is almost perfectly Faradaic in vitro up to 0.8 C. The silver ions thus liberated were effective in inhibiting the growth of microorganisms. IT has potential for development as a charge-controlled topical antimicrobial agent.
Multiple Roles of Tail Display by the Curly‐Tailed Lizard Leiocephalus carinatus: Pursuit Deterrent and Deflective Roles of a Social Signal

The same display may be used in different contexts to convey different messages, or may have other, non-signaling functions. Several lines of evidence suggest that vertical tail curling, a previously documented social display in the lizard Leiocephalus carinatus, has antipredatory functions that may include pursuit deterrence and deflection of attacks from the body to the tail, which can be autotomized. An antipredatory role of tail curling is suggested by its more frequent occurrence when a predator is approaching than moving away, its greater frequency and intensity when a lizard is approached by a predator than when it moves spontaneously, and its greater frequency when the predator approaches directly rather than on a path bypassing the lizard. Evidence is presented contradicting use of tail curling for flash concealment or as an alarm signal to conspecifics. A pursuit-deterrent function of tail curling is suggested by its (1) more frequent use by lizards close to a refuge than those further from a refuge, (2) greater frequency during direct approaches by predators, and (3) much greater frequency when a predator is far enough away for pursuit to be deterred than when the predator is close enough to pose a high risk of capture. Lizards fled into a refuge without tail curling when the predator was very close, but often stopped outside a refuge while displaying the curled tail when the predator was farther away. Tail curling also may deflect attacks to the autotomizable tail, as suggested by its occurrence during spontaneous movements when no predator is approaching and by the high frequency of completely uncurled tails among individuals under bushes. The role of the tail in autotomy may facilitate evolution of pursuit-deterrent signals involving the tail.
Spectrum of gross motor function in extremely low birth weight children with cerebral palsy at 18 months of age.

Objective. The purpose of this study was to evaluate the relationship between cerebral palsy (CP) diagnoses as measured by the topographic distribution of the tone abnormality with level of function on the Gross Motor Function Classification System (GMFCS) and developmental performance on the Bayley Scales of Infant Development II (BSID-II). It was hypothesized that (1) the greater the number of limbs involved, the higher the GMFCS and the lower the BSID-II Motor Scores and (2) there would be a spectrum of function and skill achievement on the GMFCS and BSID-II Motor Scores for children in each of the CP categories. Methods. A multicenter, longitudinal cohort study was conducted of 1860 extremely low birth weight (ELBW) infants who were born between August 1, 1995 and February 1, 1998, and evaluated at 18 to 22 months9 corrected age. Children were categorized into impairment groups on the basis of the typography of neurologic findings: spastic quadriplegia, triplegia, diplegia, hemiplegia, monoplegia, hypotonic and/or athetotic CP, other abnormal neurologic findings, and normal. The neurologic category then was compared with GMFCS level and BSID-II Motor Scores. Results. A total of 282 (15.2%) of the 1860 children evaluated had CP. Children with more limbs involved had more abnormal GMFCS levels and lower BSID-II scores, reflecting more severe functional limitations. However, for each CP diagnostic category, there was a spectrum of gross motor functional levels and BSID-II scores. Although more than 1 (26.6%) in 4 of the children with CP had moderate to severe gross motor functional impairment, 1 (27.6%) in 4 had motor functional skills that allowed for ambulation. Conclusions. Given the range of gross motor skill outcomes for specific types of CP, the GMFCS is a better indicator of gross motor functional impairment than the traditional categorization of CP that specifies the number of limbs with neurologic impairment. The neurodevelopmental assessment of young children is optimized by combining a standard neurologic examination with measures of gross and fine motor function (GMFCS and Bayley Psychomotor Developmental Index). Additional studies to examine longer term functional motor and adaptive-functional developmental skills are required to devise strategies that delineate therapies to optimize functional performance.
New U.S. climate change policy draws questions about its scientific basis

Statements in March by U.S. President George W. Bush' administration opposing the Kyoto Protocol to the United Nations Framework Convention on Climate change (UNFCCC), without yet suggesting any alternative to reducing greenhouse gas emissions, have prompted a number of scientists and policy analysts to question whether the administration—which has emphasized the importance of relying on sound science—based this decision on sound science.
A highly sensitive immunoassay for interleukin-6 in dried blood spots.

Objective: Interleukin-6 (IL-6) is a pro-inflammatory cytokine that is associated with the production of C-reactive protein, the acute phase response, and chronic low-grade inflammation. In this report, we describe and validate a highly sensitive enzyme-linked immunosorbent assay (ELISA) for quantifying IL-6 at low concentrations in samples of capillary whole blood collected from a simple finger stick and dried on filter paper (dried blood spots, DBS). Methods: A commercially available ELISA for IL-6 was modified to develop a protocol for the quantification of IL-6 in DBS samples. Procedures for sample elution and incubation were optimized for precision, reliability, accuracy, and lower limit of detection using small volumes of DBS. A set of 46 matched serum/DBS samples were used to evaluate agreement between serum and DBS results. Results: The protocol demonstrated acceptable levels of precision, reliability, accuracy, and agreement with serum-based results. The lower limit of detection was sufficiently low to measure levels of IL-6 associated with both chronic, low-grade inflammation, and acute increases in inflammatory activity. Conclusions: This protocol adds to the growing panel of analytes validated for quantification in DBS samples and should facilitate future research on the causes and consequences of inflammation in diverse non-clinical settings. Am. J. Hum. Biol., 2012. © 2012 Wiley Periodicals, Inc.
Energy-efficient nonstationary power control in cognitive radio networks

Spectrum sharing policies are essential for cognitive radio networks, where primary and secondary users aim to minimize their average energy consumptions subject to minimum throughput requirements. Most existing works proposed stationary spectrum sharing policies, in which users transmit simultaneously at fixed power levels, and need to transmit at high power levels due to multi-user interference. In this paper, we propose nonstationary spectrum sharing policies in which users transmit in a TDMA fashion (but not necessarily in a round-robin manner). Due to the absence of multi-user interference and the ability to let users adaptively switch between transmission and dormancy, our proposed policy greatly improves the spectrum and energy efficiency, and ensures no interference to primary users. Moreover, the proposed policy achieves high energy efficiency even when users have erroneous and binary feedback about their received interference and noise power levels. The proposed policy is also deviation-proof, namely the autonomous users find it in their self-interests to comply with the policy. The proposed policy can be implemented by each user running a low-complexity algorithm in a distributed fashion. Compared to existing policies, the proposed policies can achieve an energy saving of up to 80%.
Lead‐free and No‐clean Soldering for Automotive Electronics*

As the electronics industry moves towards the 21st century, environmentally conscious manufacturing is becoming a very important issue for the industry. In recent years, advanced manufacturing technologies have been developed for automotive electronics packing that not only are environmentally friendly, but also reduce manufacturing complexity and cost, improve product quality, and meet the stringent reliability requirements for the automotive environment. In this paper, aspects of no‐clean soldering and lead‐free solderr development are reviewed, and some of the most critical factors for implementing no‐clean soldering and for developing lead‐free solders for automotive electronics are outlined.
Hardware tansactional memory support for lightweight dynamic language evolution

Lightweight dynamic language runtimes have become popular in part because they simply integrate with a wide range of native code libraries and embedding applications. However, further development of these runtimes in the areas of concurrency, efficiency and safety is impeded by the desire to maintain their native code interfaces, even at a source level. Native extension modules' lack of thread safety is a significant barrier to dynamic languages' effective deployment on current and future multicore and multiprocessor systems. We propose the use of hardware transactional memory (HTM) to aid runtimes in evolving more capable and robust execution models while maintaining native code compatibility. To explore these ideas, we constructed a full-system simulation infrastructure consisting of an HTM implementation, modified Linux kernel and Python interpreter.Python includes thread constructs, but its primary implementation is not architected to support their parallel execution. With small changes, a runtime can be made HTM-aware to enable parallel execution of Python code and extension modules. We exploit the semantics of Python execution to evaluate individual bytecodes atomically by default, using nested transactions to emulate programmer-specified locking constructs where possible in existing threaded code. We eliminate common transactional conflicts and defer I/O within transactions to make parallel Python execution both possible and efficient. Transactions also provide safety for foreign function invocations. We characterize several small Python applications executing on our infrastructure.
Mechanical performance of polysulfone, polybutylene, and polyamide 6/6 in hot chlorinated water

Polymer materials considered for use in domestic hot water heating systems must maintain mechanical properties in the working fluid over their target lifetimes. In potable water, chlorine and pH combine to create an oxidative environment, commonly characterized by the oxidative reduction potential (ORP), that can chemically attack a polymer, resulting in permanent loss of mechanical strength and stiffness. Water absorption and hydrolysis can also impact polymer properties. In the present study, experiments were conducted to evaluate the mechanical performance of polysulfone, polybutylene, and polyamide 6/6 immersed for up to 1100 h in water at ORP levels of 550 and 825 mV at 60 and 80 °C. Mechanical performance was evaluated by measuring creep compliance and the change in tensile strength and molecular weight after exposure. Surface morphology of the exposed materials was examined using scanning electron microscopy. Polyamide 6/6 showed significant degradation in strength and creep compliance in all environments. Despite some variability in measured properties, the blend of polybutylene, which has additives to prolong life, did not degrade. Polysulfone performed the best of the three materials with no discernable change in properties over the duration of the experiments.
Welcoming Undergraduates to Special Collections

Special Collections libraries and librarians have increasingly strived to provide more access and openness to their collections and services. However, not all students have received the message. If “perception is reality” we need to change the perception of research libraries as an intimidating place, even when we believe we are welcoming to all. Kenneth Spencer Research Library, the rare books and manuscripts library of the University of Kansas, adopted two major initiatives during the summer with the express purpose of making our library more welcoming and accessible. Spencer Library staff has worked hard over the years to engage with faculty and students and promote use of our collections. As the number of class requests increase, we are making progress but still encounter assumptions that students will not be welcomed and it will be a confusing and intimidating process. In addition to bringing students into the building, we must show them once they arrive that we are a modern facility, even if our collections are historical. A warm, welcoming presence and an efficient mode of operation can go a long way toward getting students to give you the benefit of the doubt as you show them how special collections can inform their own research.
A Mechanism for the Antiandrogenic Action of Medrogestone

The antiandrogenic action of the progestin, medrogestone, in rat and man was ascribed initially to an alteration in testosterone biosynthesis and metabolism rather than to a direct effect via the androgen receptor. However in previous studies we had found that many progestins bind directly to the androgen receptor in mouse kidney and have androgenic, antiandrogenic or synandrogenic activity. It was thus of interest to characterize the effect of medrogestone on androgen action in mouse kidney and to determine if this progestin was bound by the androgen receptor. Medrogestone inhibited the growth response and increase in the activity of β-glucuronidase and alcohol dehydrogenase induced by exogenous testosterone in the kidney of castrate male mice. It also inhibited the growth response of preputial gland and seminal vesicle. This progestin suppressed nuclear uptake of [3H]androgen in kidney, seminal vesicle and submaxillary gland following the in vivo administration of [3H] testosterone. In vitro, medrogestone directly inhibited [3H]testosterone binding by the androgen receptor in mouse kidney cytosol. To insure that these effects were not unique to the mouse, similar studies were repeated in the rat. In this species, medrogestone also inhibited nuclear androgen accumulation and receptor binding in prostate and seminal vesicle. Thus medrogestone can affect androgen action directly via binding to the androgen receptor in the mouse and rat.
Hemoglobins A and A2 in New World Primates: Comparative Variation and Its Evolutionary Implications

Hemoglobin A 2 (α 2 δ 2 ) in New World primates represents about 1/160 to 1/16 of total hemoglobin and, by virtue of this low proportion, is presumed to be functionally unimportant. Nonetheless, A 2 exhibits genetic polymorphism by electrophoresis in three out of five genera, whereas the major component, hemoglobin A (α 2 β 2 ), is electrophoretically invariant. Moreover, in four genera, including man, the evolutionary accumulation of mutations has been greater in δ than in β Such findings suggest that both polymorphism and evolutionary changes can accrue to an effectively functionless and thus selectively nearly netutral gene.
A mutation in Escherichia coli that mimics diauxie lag.

Abstract We have described a mutant of E. coli (2S142) which shows a specific inhibition of stable RNA synthesis at 42°. The temperature sensitive lesion differs from the stringent response to amino acid starvation in that the shut off of rRNA synthesis is not associated with an inhibition of protein synthesis. The decay of ppGpp is slow at 42° with little or no pppGpp detectable. This slow decay rate is not observed in the parental strain, D10, or in 2S142 at 30°. Neither 2S142 or D10 are spoT, nor does the temperature sensitive lesion map near the spoT locus. Thus, the effect of the temperature sensitive lesion on ppGpp metabolism and rRNA synthesis seems to resemble a carbon source downshift (diauxie lag) rather than a stringent response to amino acid starvation.
A new dimension to hummingbird-flower relationships.

The close correspondence between the bills of hummingbirds and the lengths of the flowers they feed from has been interpreted as an example of coadaptation. Observations of birds feeding at flowers longer and shorter than their bills, however, and the lack of experimental evidence for any feeding advantage to short bills, seem to contradict this interpretation. I address this problem by considering a little-studied dimension of floral morphology: corolla diameter. In laboratory experiments on female ruby-throated hummingbirds (Archilochus colubris), probing abilities (maximum extraction depths) increased with increasing corolla diameter. Handling times increased with decreasing corolla diameter, resulting in “handling time equivalents”, i.e., flowers having the same handling times but different lengths and diameters. Longer-billed birds had greater maximum extraction depths and shorter handling times than shorter-billed birds at all corolla diameters greater than the width of the bill. In contrast, shorter-billed birds made fewer errors inserting their bills into narrow flowers. Hence, differences in bill lengths apparently are associated with trade-offs in foraging abilities, whereby longer-billed birds are able to feed at long flowers and may do so more quickly, whereas shorter-billed birds are able to feed more successfully at narrow flowers.
Piagetian tasks measure intelligence and intelligence tests assess cognitive development: A reanalysis☆

Abstract A reanalysis of the intercorrelations of Wechsler subtests, achievements tests, and Piagetian tasks originally published by Stephens et al. (1972) has corrected errors in the original design and has used models which allow both differences and similarities to appear. Unit weighted composites of the two sets of tests were formed after first partialling chronological age out of the complete table of intercorrelations. The correlation between the composites is .876 which corrects, using split-half estimates of reliabilities, to .918. Next the matrix of partial correlations was factored and the factors rotated to a hierarchical structure. Piagetian tasks contribute almost equally to the definition of the general factor in intelligence along with the Wechsler subtests and the achievement tests. The general factor, furthermore, makes the single largest contribution to the variance of most of the measures of both sets. The smaller group factors consist of an Academic Achievement factor and three Piagetian factors. Of the latter the largest and most clearly identified is the factor called Operational Thought in the earlier analysis, but is here described simply as Conservation. It is concluded that the evidence for communality in function far outweighs the differences between intelligence tests and Piagetian tasks.
Efficacy of Combination of N‐acetylcysteine, Gentamicin, and Amphotericin B for Prevention of Microbial Colonization of Ventricular Assist Devices

We assessed the in vitro antimicrobial activity and the in vivo efficacy of dipping ventricular assist devices in a combination of N-acetylcysteine, gentamicin, and amphotericin B (NAC/G/A). Ventricular assist devices dipped in NAC/G/A exhibited broad-spectrum antimicrobial activity in vitro and were less likely than undipped devices to become colonized with Staphylococcus aureus in a rabbit model.
Analysis of multidimensional difference-of-Gaussians filters in terms of directly observable parameters

The difference-of-Gaussians (DOG) filter is a widely used model for the receptive field of neurons in the retina and lateral geniculate nucleus (LGN) and is a potential model in general for responses modulated by an excitatory center with an inhibitory surrounding region. A DOG filter is defined by three standard parameters: the center and surround sigmas (which define the variance of the radially symmetric Gaussians) and the balance (which defines the linear combination of the two Gaussians). These parameters are not directly observable and are typically determined by nonlinear parameter estimation methods applied to the frequency response function. DOG filters show both low-pass (optimal response at zero frequency) and bandpass (optimal response at a nonzero frequency) behavior. This paper reformulates the DOG filter in terms of a directly observable parameter, the zero-crossing radius, and two new (but not directly observable) parameters. In the two-dimensional parameter space, the exact region corresponding to bandpass behavior is determined. A detailed description of the frequency response characteristics of the DOG filter is obtained. It is also found that the directly observable optimal frequency and optimal gain (the ratio of the response at optimal frequency to the response at zero frequency) provide an alternate coordinate system for the bandpass region. Altogether, the DOG filter and its three standard implicit parameters can be determined by three directly observable values. The two-dimensional bandpass region is a potential tool for the analysis of populations of DOG filters (for example, populations of neurons in the retina or LGN), because the clustering of points in this parameter space may indicate an underlying organizational principle. This paper concentrates on circular Gaussians, but the results generalize to multidimensional radially symmetric Gaussians and are given as an appendix.
Phase diagram of coulomb interactions across the metal-insulator transition in Si:B.

Measurements of the single-particle density of states (DOS) near T=0 ?K in Si:B are used to construct an energy-density phase diagram of Coulomb interactions across the critical density n{sub c} of the metal-insulator transition. Insulators and metals are found to be distinguishable only below a phase boundary (|n/n{sub c}-1|) determined by the Coulomb energy. Above ? is a mixed state where metals and insulators equidistant from n{sub c} cannot be distinguished from their DOS structure. The data imply a diverging screening radius at n{sub c}, which may signal an interaction-driven thermodynamic state change.
Viability and ATP content of conidia of sorbic acid-sensitive and-resistant strains of Penicillium roqueforti after exposure to sorbic acid

Conidia from two strains of Penicillium roqueforti, one sensitive and one resistant to inhibition by sorbic acid, were tested to determine how the chemical affected viability and ATP content of the spores. The minimum inhibitory concentration was less than 1,000 ppm for the sensitive strain and 3,000 ppm for the resistant strain. Exposing conidia to 6,000 ppm sorbic acid caused complete loss of viability in 1 day by those of the sensitive strain and in 4 days by those of the resistant strain. Exposure of conidia to sorbate solutions caused a rapid initial decrease in ATP content during the first few hours, followed by a more gradual decrease over the next 48–72 h. The same general trend was observed for both strains, but the resistant strain recovered some of the lost ATP following the rapid initial decrease. Results suggest that increased viability in the resistant strain may result from maintainance of ionic balance and an internal pH high enough to reduce the effectiveness of sorbic acid.
Superoxide anion release by human endothelial cells: Synergism between a phorbol ester and a calcium ionophore

In order to study the signal transduction mechanism of human endothelial cells (EC), the regulation of superoxide anion (O2−) release in EC has been investigated using the calcium ionophore A23187 and phorbol myristate acetate (PMA), a potential activator of the Ca2+ activated, phospholipid-dependent protein kinase, designated “protein kinase C.” PMA enhanced O2− release from EC, and this enhancement occurred regardless of the presence or absence of extracellular Ca2+. A similar increase was produced by A23187; omission of extracellular Ca2+ prevented this increase. Simultaneous stimulation with PMA and A23187 produced a large increase in O2− release at submaximal concentrations of these agents, which, when added separately, caused minimal effects. These findings indicate that the activation of protein kinase C and mobilization of Ca2+ evoked by PMA and A23187 respectively are synergistically effective for eliciting a full physiological response of EC in the generation and release of O2−.
Giant Right Atrium in Ebstein's Anomaly

On physical examination the patient was severely dyspneic while sitting straight upright. The blood pressure was 200/ 120 mm Hg, and the pulse rate was 94 beats per minute and irregularly irregular. The respiration rate was 28/mm. The lungs were clear. The apical impulse of the heart was palpable 3 cm to the left of the midclavicular line in the fifth intercostal space. There was a prominent left parasternal lift. The first heart sound was loud, and at the lower left sternal border, there was a soft systolic murmur which became louder with deep inspiration. The liver was palpable 6 cm below the right costal margin. There was moderate pretibial and pedal edema of both legs. The nail beds of all extremities were cyanotic.
Performance analysis of disk cache write policies

Abstract Many different techniques for bridging the performance gap between CPUs and I O devices have been studied. Among these is data caching at the disk controller. Of interest is the effectiveness of a disk cache under the presence of a higher level cache, such as the UNIX file buffer cache. Disk activity logs from a UNIX workstation file server have been collected and analysed. Results have been used to guide the design of disk cache architectures, which are analysed using simulations driven by the activity logs. The primary focus is on disk cache write strategies. It is shown that write-through policies achieve the best read response time, with a 4MB cache performing approximately 30% better than no cache. Write-back policies do not achieve the performance of write-through policies (nor even the performance of a system with no disk cache) due to a phenomenon referred to as ‘head thrashing’. Scheduled write-back, a new write policy that utilizes disk idle time to write dirty lines from the cache efficiently, is examined as a solution to the problem and is shown to achieve performance equivalent to that of write-through under light to moderate loads. A variation of the pure LRU replacement algorithm, LRU over clean lines, is proposed for use with scheduled write-back, and is shown to achieve read response times significantly less than pure write-through under simulated heavier loads.
Tunable Frequency Selective Surfaces and Negative-Zero-Positive Index Metamaterials Based on Liquid Crystals

We utilize the properties of aligned nematic liquid crystal (LC) cells in the design of: (i) a new type of metamaterial whose index of refraction is tunable from negative, through zero, to positive values and (ii) micron-scale metallodielectric and all-dielectric tunable frequency selective surfaces (FSSs). The metamaterial is constructed by randomly doping a liquid crystal substrate with coated dielectric (non-magnetic) spheres and can be utilized over a large spectral range. FSSs with a liquid crystal superstrate are synthesized using conventional and genetic algorithm methods to exhibit broadband tunable filter characteristics at mid-infrared (mid-IR) wavelengths. These LC tunable FSS structures can be used to develop a new class of infrared/optical switches for terahertz applications.
Deuterium Abundance in the Interstellar Gas of the Galactic Anticenter from the 327 MHz Line

The deuterium abundance in the primordial gas formed during the big bang is dependent on the baryon-to-photon ratio during nucleosynthesis. We report a measurement of the deuterium-to-hydrogen (D/H) ratio from a 6 σ detection of the hyperfine ground-state transition of deuterium at 327 MHz (92 cm) in emission from the interstellar gas in the region of the Galactic anticenter. We find the maximum signal at l = 183°, where the deuterium line opacity is expected to be a maximum as a result of velocity crowding. Using these deuterium and existing hydrogen observations, we model the effects of beam dilution, spin temperature, and absorption of continuum to derive a D/H ratio of 2.3 × 10-5 by number. The errors are ±3 σ plus our estimate of the systematic uncertainty in the conversion of the observed line amplitude to the D/H ratio.
International students and awareness of digital scanning issues

The legal and ethical issues raised by the ability to use desktop scanners to convert images into digital data for manipulation, enhancement, and eventual incorporation into a publication are discussed. Potential legal problems involve copyright infringement and libel, both of which are familiar concerns to technical writers, although they tend to be associated with text rather than graphic images. Ethical issues raised by the available technology include concerns about enhanced advertisements. To maintain public confidence in digitally processed images, technical communicators in academia must provide guidelines for their students, both US and international, who will encounter many of these legal and ethical issues in the workplace. >
DEXAMETHASONE SUPPRESSION TESTS: USEFULNESS OF SIMULTANEOUS MEASUREMENT OF PLASMA CORTISOL AND DEXAMETHASONE

The effect of oral dexamethasone on the plasma content of cortisol and dexamethasone was investigated in 175 patients suspected of having Cushing's syndrome. Plasma concentrations of cortisol and dexamethasone were measured by specific radioimmunoassays at 08.00 h following administration of either a low-low (0.5 mg), low (1.0 mg), high (4.0 mg) or high-high (8.0 or more mg) dose of dexamethasone at midnight. All seventeen patients with documented Cushing's syndrome exhibited resistance to the action of low-low and/or low dose dexamethasone on suppression of 08.00 h plasma cortisol content. Nine of twelve patients with pituitary dependent Cushing's syndrome had plasma cortisol values of less than 166 nmol/l following high-high dose testing. In 157 patients with suspected Cushing's syndrome, standard dexamethasone testing was considered unsatisfactory in at least 20%. After low-low or low dose tests 11% had supranormal cortisol values, but plasma cortisol content overlapped with values observed in patients with Cushing's syndrome only when plasma dexamethasone content was less than 5.6 nmol/l. Twelve per cent of patients suspected of having Cushing's syndrome had sufficient elevation of plasma dexamethasone values after low dose testing so that marked reduction of plasma cortisol might be expected even in patients with pituitary dependent Cushing's syndrome. Four patients receiving anticonvulsants had subnormal plasma levels of dexamethasone for the dose administered, but all exhibited normal suppression when plasma levels of dexamethasone and cortisol were correlated simultaneously. In summary, there is considerable variation in the plasma content of dexamethasone following oral doses. Simultaneous measurement of both plasma levels of dexamethasone and cortisol has proved most useful in identifying patients with unsatisfactory dexamethasone suppression tests.
SH3 domains come of age

With the sequencing of an eukaryotic genome, it is possible to inventory the predicted proteome for proteins that carry one or more Src Homology 3 (SH3) domains. Due to the current ease of cloning and gene synthesis, these short domains can be readily overexpressed and manipulated for the purpose of characterizing their specificity and affinity for peptide ligands, as well as solving the three-dimensional structures of the domains. This information can be used to predict and confirm their cellular interacting partners, in the effort to understand the function of a eukaryotic protein by focusing on its SH3 domain. Finally, capitalizing on our mature understanding about protein–protein interacting modules, like the SH3 domain, it is possible to use directed evolution to enhance or change the specificity and affinity of an SH3 domain for the purpose of creating reagents to be used in biochemical purification or cell perturbation studies.
A single shot at Salmonella typhi: a new typhoid vaccine with pediatric advantages.

A new typhoid vaccine has just been licensed, which is the third typhoid vaccine available in the United States.1,2 Since publication of the 1994 Red Book occurred before licensure, this new vaccine is not included. The recommendations concerning the two previously licensed typhoid vaccines in the 1994 Red Book remain unchanged.3 The new vaccine, Typhoid Vi, is manufactured by Pasteur Merieux (Marnes-La-Coquette, France). This parenteral vaccine is composed of the purified Vi (virulence) antigen, which is the capsular polysaccharide (ViCPS) of Salmonella typhi. The two previously licensed typhoid vaccines are an oral live-attenuated vaccine, the Ty21a vaccine, manufactured by the Swiss Serum and Vaccine Institute, and the parenteral heat-phenol-inactivated vaccine (Berne, Switzerland), manufactured by Wyeth-Ayerst, which has been available for many years.
Agile monitoring for cyber defense

The Monitoring, Analysis, and Interpretation Tool Arsenal (MAITA) seeks to support rapid construction and empirical reconfiguration of cyber defense monitoring systems inside the opponent decision cycle through a set of mechanisms including a flexible infrastructure for distributed monitoring processes and signal flows, a monitoring executive that coordinates resource allocation and systemic self-monitoring, and a library of monitoring process types, event descriptions, event recognition methods, alerting decision models, and other forms of monitoring knowledge.
Carbon Nanotubes as a Framework for High-Aspect-Ratio MEMS Fabrication

A class of carbon-nanotube (CNT) composite materials was developed to take advantage of the precise high-aspect-ratio shape of patterned vertically grown nanotube forests. These patterned forests were rendered mechanically robust by chemical vapor infiltration and released by etching an underlying sacrificial layer. We fabricated a diverse variety of functional MEMS devices, including cantilevers, bistable mechanisms, and thermomechanical actuators, using this technique. A wide range of chemical-vapor-depositable materials could be used as fillers; here, we specifically explored infiltration by silicon and silicon nitride. The CNT framework technique may enable high-aspect-ratio MEMS fabrication from a variety of materials with desired properties such as high-temperature stability or robustness. The elastic modulus of the silicon-nanotube and silicon nitride-nanotube composites is dominated by the filler material, but they remain electrically conductive, even when the filler (over 99% of the composite's mass) is insulating.
The Play Time Manifesto: Why Having Fun Makes Us Better Workers

Column Editor's Note. Many librarians enjoy their work, but is it appropriate to play while on the job? This article explores theories of play that increasingly indicate that having fun at work can...
Reliability and Feedback of Multiple Hop Wireless Networks

This paper analyzes fault-tolerance over the entire design life of a class of multiple-hop wireless networks, where cooperative transmission schemes are used. The networks are subject to both node failure and random channel fading. A node lifetime distribution is modeled with an increasing failure rate, where the node power consumption level enters the parameters of the distribution. A method for assessing both link and network reliabilities projected at the network’s design life is developed. Link reliability is enhanced through use of redundant nodes. The number of redundant nodes is restricted by the cooperative transmission scheme used. The link reliability is then used to establish a re-transmission control policy that minimizes an expected cost involving power, bandwidth expenditures, and packet loss. The benefit and cost of feedback in network operations are examined. The results of a simulation study under specific node processing times are presented. The study quantifies the effect of loop closure frequency, acknowledgment deadline, and nodes’ storage capacity on the performance of the network in terms of network lifetime, packet loss rate, and false alarm rate. The study concludes that in a network where energy is severely constrained, feedback must be applied judiciously.
Heparin Increases Exercise-Induced Collateral Blood Flow in Rats With Femoral Artery Ligation

Abstract The potential for heparin to enhance the training-induced increase in collateral-dependent blood flow to the distal hind-limb muscles was evaluated after bilateral femoral artery ligation in adult male rats (≈350 g). Rats received either saline (n=34) or heparin (n=36) injections and were kept sedentary (limited to cage activity) or exercised on a treadmill 5 days per week up a 15% incline by one of two protocols: (1) exercise at a constant moderate speed (20 m/min) for ≈6 wks or (2) exercise at a progressively increased speed for 7 to 8 weeks (started at 20 m/min, increased at 15 minutes to 25 m/min, and then increased at 30 minutes to 30 m/min). Heparin- and saline-treated rats, exercised by the moderate-speed protocol, were run for the same time each day. Collateral-dependent blood flow to the distal limb tissue was determined by using 15-μm 85Sr-labeled microspheres in an isolated hindquarter preparation perfused in the descending aorta at 100 mm Hg. For comparison with the above groups, sedentary animals with acute femoral artery ligation and without femoral obstruction were included. Exercise tolerance increased from ≈7 minutes initially to 30 to 40 minutes per bout; tolerance was greater in the heparin-injected rats than in the saline-injected rats ( P <.05). Muscle performance of the gastrocnemius-plantaris-soleus muscle group (GPS) during isometric contractions in situ improved with training, was further increased by heparin administration ( P <.001), and generally scaled with recovery of blood flow. Collateral-dependent blood flow in the GPS of the heparin-injected exercised groups (40±4 and 56±3 mL/min per 100 g) was greater than that in the saline-injected exercised groups (19±3 and 30±5 mL/min per 100 g), and blood flow in both of these groups was greater than that in the sedentary groups (14±4 and 12±2 mL/min per 100 g) ( P <.005). Heparin injections did not alter collateral-dependent blood flow in the absence of exercise training. Thus, exercise appears to impart an essential stimulus for collateral vessel development that is enhanced by heparin administration.