cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of velocity on ground reaction forces in dogs with lameness attributable to tearing of the cranial cruciate ligament.

Objective-To ascertain the effectiveness of evaluating ground reaction forces (GRFs) at velocities during walking and trotting in dogs with naturally occurring lameness and determine whether walking would provide sufficient motion to adequately characterize GRFs with respect to trotting. Animals-29 dogs with a naturally occurring tear of the cranial cruciate ligament. Procedure-Dogs were walked and trotted over a force platform, and GRFs were recorded during the stance phase. Correlation was used to assess the agreement between walking and trotting for GRF. The coefficient of variation was calculated to assess the relative variation of outcome variables among the gaits. Group means for walking GRF were compared between dogs that trotted and that failed to trot. Results-GRFs during walking and trotting were highly correlated. The coefficient of variation was smaller for GRFs during walking than during trotting. Dogs that failed to trot had significantly smaller mean values of peak vertical force and vertical impulse during walking, compared with values for dogs that were able to trot. Conclusions and Clinical Relevance-Either velocity is acceptable for GRF evaluation in dogs. Mean GRF during walking was significantly different between dogs that could and could not trot, principally because dogs with the most severe lameness failed to trot. These dogs would be eliminated from a clinical study, and thus, that study would become biased toward dogs that were less lame. In that situation, differences between interventions may be less pronounced, because they would be evaluated on dogs with less lameness.
Influence of European corn borer (Lepidoptera: Pyralidae) feeding on various stages of field corn in Kansas

The impact of second-generation European corn borer (ECB), Ostrinia nubilalis (Hubner) stalk tunneling on yield reductions in corn, Zea mays L., was investigated for the Kansasproduction system. The stage of corn development when larval tunneling was initiated, vertical location of larvae on the plant, and number of larvae per plant were variables in the study. The probability of ECB larval occurrence at nodes above ground level was highest on the ear node; larval frequency decreased rapidly as distance increased from the ear node. Acrossall fields, the average probability of larval occurrence per stratum was 18.4, 59.5, and 22.1% for the bottom, middle, and top strata, respectively. A significant negative linear relationship between grain yield and level of infestation in the bottom and middle strata was fitted for all plant stages, with the exception of bottom-dent in 1981 and middle-dough in 1982. No relationship was seen between grain yield and level of infestation in the top stratum regardless of plant stage. The relationship between percentage yield reduction and cumulative corn growing degree-days (GDD) remaining to corn physiological maturity was described using a second-degree polynomial equation. Maximum potential yield reduction as a result of tunneling initiated by third-instar larvae was predicted to occur when ca. 35.7% of the corn GDD remained to physiological maturity. This coincided approximately with initiation of the blister stage. The percentage yield reduction per borer decreased as tunneling was initiated nearer to physiological maturity. Larval tunneling initiated during the pollination period of corn development appeared to have a smaller effect on yield than tunneling initiated near blister stage.
Toward eliminating catheter-associated urinary tract infections in an academic health center

Abstract Background Eliminating catheter-associated urinary tract infections (CAUTI) is at the forefront of quality improvement and cost reduction for payers and hospitals alike. Herein we describe a double-focused strategy to eliminate CAUTI's on a surgical oncology unit over the course of 24 mo. Methods CAUTI's were tracked on a 30-bed surgical oncology unit 12 mo before and 12 mo after implementation of specific measures aimed at (1) decreasing utilization and (2) increasing catheter bundle and hand hygiene compliance. A policy of early Foley catheter removal was implemented. Univariate analyses were performed comparing nominal and numerical variables between the pre- and post-intervention groups. Results The pre- and post-intervention groups comprised of 1376 and 1467 patients, respectively. Postintervention, there was a significant decrease in both total Foley ( P = 0.02) and patient ( P = 0.03) days. This resulted in a significant reduction in utilization rate from 0.28 to 0.24, ( P P = 0.03). Reduced CAUTIs were associated with significant improvements in monthly bundle compliance at ≥95% (75% versus 17%, P = 0.003) and hand hygiene compliance at ≥95% (92% versus 58%, P = 0.05). Among our thoracic epidural cohort ( n = 11), three patients (27%) required reinsertion for urinary retention. None of these epidural patients were diagnosed with a CAUTI. Conclusions Although not eliminated entirely, CAUTIs on our unit were significantly reduced through decreased utilization and improved compliance to institutional patient safety measures. Adoption of these strategies to other inpatient units would not only improve patient safety but also result in significant cost savings.
Extending types to modeling problem-space entities

Structural computing has evolved from Work on open hypermedia to aid in the construction of domain-specific software infrastructure and tools. Part of the premise of structural computing has been that by focusing on the abstraction of structure rather than on a concrete data layer, it should make it easier for developers to use appropriate levels of abstraction to build applications. By using the appropriate level of abstraction, the resulting systems can represent components in ways that closely reflect the problem space, instead of forcing the problem into an implementation-centric paradigm. Our previous work has concentrated on how to accomplish these ends through the abstraction of data--this paper concentrates on the benefits of abstraction of type. As our concern is primarily with modelling the problem space in an application domain, we approach 'type' initially from a problem-space viewpoint, not from a theoretic model. 'Type' is not a monolithic concept: a type may be an interface definition, a set of properties, or a classification. The meaning of a type depends on the individual entity to which the type is being applied, as well as the context in which the typing occurs. The meaning of 'type' in a problem domain may differ greatly from 'type' in an application addressing that domain, and the distinction must be kept clear. Types, like the entities to which they are applied, are not necessarily static. This observation is especially important in applications addressing domains that involve complex activities. This paper proposes a framework for distinguishing among the varieties of 'type' and describes uses for each. In the context of structural programming, we discuss techniques for building context-dependent extensions to existing types (whether interface definitions or classifications) that support applications where both the definitions of types and the classification of items are subject to change. We contextualize this work with respect to related research, and with more general software development concerns.
Identification of YHR068w in Saccharomyces cerevisiae Chromosome VIII as a Gene for Deoxyhypusine Synthase EXPRESSION AND CHARACTERIZATION OF THE ENZYME

Abstract Deoxyhypusine synthase catalyzes the formation of deoxyhypusine, the first step in hypusine biosynthesis. Amino acid sequences of five tryptic peptides from rat deoxyhypusine synthase were found to match partially the deduced amino acid sequence of the open reading frame of gene YHR068w of Saccharomyces cerevisiae chromosome VIII (AC:U00061). In order to determine whether the product of this gene corresponds to yeast deoxyhypusine synthase, a 1.17-kilobase pair cDNA with an identical nucleotide sequence to that of the YHR068w coding region was obtained from S. cerevisiae cDNA by polymerase chain reaction and was expressed in Escherichia coli B strain BL21(DE3). The recombinant protein was found mostly in the E. coli cytosol fraction and comprised 20% of the total soluble protein. The purified form of the expressed protein effectively catalyzed the formation of deoxyhypusine in yeast eIF-5A precursors as well as in human precursor and in those from Chinese hamster ovary cells. The molecular mass of the enzyme was estimated to be 172,000 ± 4,300 Da by equilibrium centrifugation. The mass of its polypeptide subunit was determined to be 43,000 Da, in close agreement with that calculated for the coding region of the YHRO68w gene. These findings show that this gene is a coding sequence for yeast deoxyhypusine synthase and that the product of this gene exists in a tetrameric form.
Security of Reconfigurable FSO Mesh Networks And Application to Disaster Areas

Optical transmission is recognized to be a cost-efficient method. Optical technology, lasers, detectors, fiber or free space and other photonic components support ultra-high data rates that exceed many Gbps per channel. Free space optical communication has an additional advantages over fiber; although it does not currently support many channels, it is fast deployable as it does not require long-term planning and installation as fiber does, and, the optical link has additional security features. In this paper we present a mesh free space optical network, which is reconfigurable, it supports "fused" payloads (voice, data, video, image) it supports wireless communication services, and it supports sensor grids. We also discuss FSO engineering, traffic and fault management, security features and deployability to disaster areas.
Parametric and autoparametric vibrations of an elevated water tower, part III: Random response

The random response characteristics of a non-linear two degree-of-freedom system subjected to wide-band random excitations are determined. The Fokker-Planck equation is used to derive a general differential equation for the response joint moments. The equation is found to consitute an infinite coupled set of differential equations which are closed by using a cumulant non-Gaussian closure scheme. In the neighborhood of a fourth order autoparametric resonance condition the non-linear modal intetaction is found to take the form of energy exchange between the normal modes. Contrary to the Gaussian closure solution, the non-Gaussian closure yields a strictly stationary response in the time domain. The response mean squares, fourth order moments, and fourth order cumulants are presented as functions of the internal resonance detuning for various system parameters. It is found that unbounded response statistics take place at certain regions above and below the exact internal resonance ratio of the system. For regions well remote from the exact internal resonance condition the system exhibits the linear response characteristics.
A substance in L-929 cell extracts which replaces the ascorbate requirement for prolyl hydroxylase in a tritium release assay for reducing cofactor; correlation of its concentration with the extent of ascorbate-independent proline hydroxylation and the level of prolyl hydroxylase activity in these cells

Abstract Reductant used as cofactor for the prolyl hydroxylase reaction, was measured by a tritium release assay modified from an enzyme assay by making all components of the assay system saturating except for the reductant, but including prolyl hydroxylase. Reduced glutathione (6 m m ), which had little activity as a cofactor, and thymol (0.1 m m ), an antioxidant which exhibited no cofactor activity at all, were required for optimal proline hydroxylation dependent on reducing cofactor, with thymol fulfilling the previously described requirement for catalase. Ascorbate, cysteine and 6,7-dimethyltetrahydropterin were active as cofactors, in descending order of activity at equimolar concentrations, and activity was concentration dependent for all of these compounds. Sonicates of stationary phase L-929 cells which exhibit ascorbate-independent proline hydroxylation in culture contained reducing cofactor which could replace ascorbate in the cofactor assay, while sonicates of log phase cells which exhibit an ascorbate requirement in culture contained about one-third or less of that amount. NADH and NADPH, which themselves have little or no activity as cofactor, increased the cofactor activity of log phase cell sonicates but had relatively little effect on the activity of stationary cell sonicates suggesting that the cofactor is in a more reduced state in stationary phase. Within 24 h after replating dense, stationary phase cell cultures at low density, conditions where cells return to ascorbate dependence, prolyl hydroxylase activity had decreased to one-fifth the original activity while the concentration of functional reducing cofactor had decreased to less than 1% of its original concentration, largely as a result of oxidation. Ascorbate was not present in L-929 cells sonicates and the levels of tetrahydropterin and cysteine in sonicates could not account for the amount of cofactor activity exhibited by the sonicates in the assay system. Treatment of L-929 cultures with aminopterin did not decrease ascorbate independence, suggesting that tetrahydrofolate did not contribute significantly to cellular proline hydroxylation. These results suggest that an unidentified reductant present in L-929 cells can account for ascorbate-independent proline hydroxylation and also regulate prolyl hydroxylase activity in these cells and that cellular levels of reduced pyridine nucleotides may regulate the reduction state of this substance.
A cognitive approach to child mistreatment prevention among medically at-risk infants.

The authors assessed the effectiveness of a home visitation program in enhancing the early parenting history of infants born at medical risk--a population that is at risk for mistreatment. A randomized clinical trial design was used to compare the effects of a cognitively based extension of the Healthy Start home visitation program (HV+) with a visitation condition that did not include this component (HV). In the HV+ condition, they observed (a) a lower use of corporal punishment, (b) greater safety maintenance in the home, and (c) fewer reported child injuries. The sample (N = 102) was primarily Latino; however, the effects of the intervention were not qualified by ethnicity, maternal education, or immigration status. Language: en
The occurrence of behavior disorders in children: the interdependence of Attention Deficit Disorder and Conduct Disorder.

A nonreferred elementary school population of 315 children participated in a screening for behavioral problems. The prevalence of inattentive-overactive symptoms suggestive of Attention Deficit Disorder (ADD) was determined to be 2.3%; 3.6% of the children had aggressive/oppositional symptoms suggestive of Conduct Disorder (CD). Another 3.0% showed both ADD and CD symptoms. Index children comprise 8.9% of the school population and were more likely to come from broken homes and had more remedial education. They also had higher scores on the ADD Interview (DICA) and were more impulsive and disorganized on a computerized attentional battery. There were no symptoms or characteristics that differentiated the inattentive-overactive (ADD) from the aggressive/oppositional (CD) child. Multivariate statistical techniques indicated a different relative importance of individual symptoms in the two groups. These results suggest the interdepencence of symptoms commonly associated with ADD and CD diagnoses.
Target-dependent survival of tadpole spinal cord neurites in tissue culture

Abstract Survival of nerve fibers growing from frog tadpole spinal cord explants in tissue culture was examined as a function of the absence or presence of target limb tissue. Neuretic outgrowth was maintained in serum-free medium for significantly longer times when cord was co-cultured with young limb tissue or limb conditioned medium than when grown alone. The results are suggested to be relevant to possible mechanisms controlling the loss of neurons from the spinal motor centers during in vivo development.
Histopathology of bullminnows, Fundulus grandis Baird & Girard, infected with a non‐haemolytic group B Streptococcus sp.

. Histopathological changes in bullminnows, Fundulus grandis Baird and Girard, experimentally infected with a non-haemolytic group B Streptococcus sp. were studied. Following experimental exposure to the Streptococcus sp. approximately 40% of the fish developed exophthalmia, dropsy or petechial haemorrhage along the abdomen. The exophthalmic eye showed haemorrhage with neutrophil infiltration. The liver was oedematous and hepatocytes were atrophied, accompanied by a decrease in glycogen and increases in vacuolization, hyaline droplet degeneration and necrosis. The spleen was congested and cells of the sheathed artery were necrotized.
Mechanical stimulation induces Ca2+i transients and membrane depolarization in cultured endothelial cells. Effects on Ca2+i in co-perfused smooth muscle cells.

Abstract Cytosolic Ca 2+ concentration and membrane potential were monitored in individual cultured enothelial cells mechanically stimulated with a micropipette attached to the stage of a microscope. Both dimpling and poking of endothelial cells resulted in Ca 2+ i transients (from 63 ± 12 to 397 ± 52 nM, characterized by a refractory period of approx. 2 min) and cell depolarization. Ca 2+ i transients of the reduced amplitude (201 ± 41 nM) were evoked by mechanical stimulation of endothelial cells incubated in a Ca 2+ -free medium. Dimpling-induced Ca 2+ i transients were refractory to the pretreatments with pertussis toxin, colchicine, or cytochalasin B, and were not mimicked by an increase in the hydrodynamic pressure. In a co-perfusion system (endothelium: smooth muscle), both the KCl-induced depolarization and ionomycin-induced increase in Ca 2+ i in the endothelial cells resulted in the reduction of Ca 2+ i in the smooth muscle cells. The data reported are consistent with the phenomenon of vascular relaxation in response to the increased blood flow. We hypothesize that the mechanical interaction of the formed elements with the microvascular endothelium can serve as a pacemaker for the sustained relaxation of vascular smooth muscle.
A metal thermal shunt design for hybrid silicon microring laser

In order to overcome the bottlenecks of limited bandwidth and increasing power consumption in CMOS chips due to conventional metal interconnects, photonic data links are an increasingly important research topic for both academia and industry. Recently demonstrated hybrid silicon(Si) microring lasers[1] can be good candidates for Si-based light sources for photonic data links.
Countertransference issues in the treatment of the military dissenter.

Institutional role pressures make it difficult for psychiatrists to escape prevailing prejudices to ostracize, exclude, or punish non-conformists. This paper identifies antitherapeutic defenses employed by military psychiatrists in dealing with dissenters, and describes their operation. It is suggested that the pressures on the psychiatrist that can be observed with particular clarity in the military are, in fact, ubiquitous, as society looks increasingly to the psychiatrist to deal with fundamental social issues.
Stereospecific Syntheses of 3‘-Deuterated Pyrimidine Nucleosides and Their Site-Specific Incorporation into DNA

2‘-Deoxy-3‘-deutero pyrimidines have been synthesized in high yields and incorporated into deoxyoligonucleotides using standard phosphoramidite chemistry. A key synthetic step is a stereospecific reduction of 3‘-keto nucleosides using sodium triacetoxyborodeuteride to give 3‘-deuterated thymidine and 2‘-deoxy uridine nucleosides. Conversion of the corresponding phorphoramidites 7a and 7b to 4-triazolo derivatives has, for the first time, enabled incorporation of 2‘-deoxy-3‘-deutero cytidine and 2‘-deoxy-3‘-deutero-5-methyl cytidine into oligonucleotides.
Galactic structure towards the Open Clusters NGC 188 and NGC 3680

We present the first comparisons of a newly developed Galactic Structure and Kinematic Model to magnitude and color counts, as well as relative proper motions, in the fields of the open clusters NGC 188 [(l, b)= (122.8 deg, +22.4 deg)] and NGC 3680 [(l,b)= (286.8 deg, +16.9 deg)]. In addition to determining the reddening toward these two clusters, it is shown that starcounts at intermediate Galactic latitudes in the range 11< V< 17 allow us to constrain the model scale-height for disk subgiants. We obtain a mean value of 250 +/- 32 pc, in agreement with previous determinations of the scale-height for red-giants. We are also able to constrain the scale-height of main-sequence stars, and the distance of the sun from the Galactic plane, ruling out the possibility of a value of +40 pc, in favor of a smaller value. Comparisons with the observed proper-motion histograms indicate that the velocity dispersion of disk main-sequence stars must increase with distance from the Galactic plane in order to match the observed proper-motion dispersion. The required increase is consistent with the values predicted by dynamical models, and provides a clear observational evidence in favor of such gradients. The shape of the observed proper-motion distribution is well fitted within the Poisson uncertainties. This implies that corrections to absolute proper motion (and, therefore, space velocities) for open clusters may be obtained using our model when no inertial reference frame is available. Using this approach, the derived tangential motions for NGC 188 and NGC 3680 are presented.
Forests and score vectors

Thescore vector of a labeled digraph is the vector of out-degrees of its vertices. LetG be a finite labeled undirected graph without loops, and let σ(G) be the set of distinct score vectors arising from all possible orientations ofG. Let ϕ(G) be the set of subgraphs ofG which are forests of labeled trees. We display a bijection between σ(G) and ϕ(G).
Optical Switching by Nonlinear Lightwave Circuits Inscribed in Chalcogenide Glass by Ultrafast Laser

We report nonlinear lightwave circuits inscribed in chalcogenide glass by ultrafast laser. Exploiting the large nonlinearity of the material, optical switching is demonstrated with reduced power in 1D waveguide array and waveguide Bragg grating.
Systemic or intrahippocampal cannabinoid administration impairs spatial memory in rats.

The purpose of the present study was to investigate the disruptive effects of cannabinoids on working memory as assessed in the eight-arm radial-maze. Systemic administration of Δ9-THC, WIN-55,212-2, and CP-55,940 increased the number of errors committed in the radial-maze. CP-55,940 was the most potent cannabinoid in impairing memory (ED50=0.13 mg/kg). Δ9-THC and WIN-55,212-2 disrupted mazechoice accuracy at equipotent doses (ED50 values =2.1 and 2.2 mg/kg, respectively). In addition, systemic administration of each of these agents retarded completion time. Whereas the doses of Δ9-THC and CP-55,940 required to retard maze performance were higher than those needed to increase error numbers, WIN-55,212-2 was equipotent in both of these measures. On the other hand, neither anandamide, the putative endogenous cannabinoid ligand, nor cannabidiol, an inactive naturally occurring cannabinoid, had any apparent effects on memory. A second aim of this study was to elucidate the neuroanatomical substrates mediating the disruptive effects of cannabinoids on memory. Intrahippocampal injections of CP-55,940 impaired maze performance in a dose-dependent manner (ED50=8 µg/rat), but did not retard the amount of time required to complete the maze. The effects of intrahippocampal CP-55,940 were apparently specific to cognition because no other cannabinoid pharmacological effects (e.g., antinociception, hypothermia, and catalepsy) were detected. This dissociation between choice accuracy in the radial-maze and other cannabinoid pharmacological effects suggests that the working memory deficits produced by cannabinoids may be mediated by cannabinoid receptors in the hippocampus.
Nonprofit organizations’ use of the World Wide Web: are they sufficiently fulfilling organizational goals?

Abstract This study explores nonprofit organizations’ Web sites to determine the extent the organizations utilize the Web to accomplish organizational goals. A sample of the 100 largest NPOs in the United States was used for the study. Results found the selected NPOs were effectively using the Web to present traditional public relations materials and connect with publics. However, the organizations were largely unsuccessful in making interactive and relational communications with publics.
Data mining-based intrusion detectors: an overview of the columbia IDS project

The field of Intrusion Detection has been an active area of research for some time. The goal of an Intrusion Detection System (IDS) is to provide another layer of defense against malicious (or otherwise unauthorized) uses of computer systems by sensing a misuse or a breach of a security policy and alerting operators to an ongoing (or, at least, recent) attack. (We make no distinction between external or internal attacks.) The field has made substantial strides since the earliest papers that have been published on the topic (eg., Denning's 1987 paper1). And today a growing market for IDSs is evidenced by the number of new companies offering various IDS products. (The IDS marketplace, however, is presently immature; many opportunities exist for new products.)
Safety of Thoracentesis in Mechanically Ventilated Patients

As practicing intensivists, we frequently diagnose pleural effusions in mechanically ventilated patients and routinely perform thoracentesis even when the patient is on positive end-expiratory pressure (PEEP). In light of a recent report, we have reviewed our experience. It is of interest that all thoracenteses were performed with patients in the lateral decubitus position. (Chest 1993; 103:1920-21)
K-theory of toeplitzC *-algebras on Lie spheres

In this paper we compute theK-groups of theC*-algebra of Toeplitz operators on the Lie spheres. As a corollary we get an index theorem for Toeplitz operators with matricial symbols analogous to the index theorem of Berger, Coburn and Koranyi for Toeplitz operators with scalar valued symbols.
How Multimedia-Based Learning and Molecular Visualization Change the Landscape of Chemical Education Research

Visualizations of molecular structure and dynamics are widely used in chemistry classrooms, although the research findings needed to make informed decisions about how best to select and use these materials often are not available. Much of the research on educational uses of visualizations that was conducted in the past does not provide the information needed for today’s students. Collaborations among the research communities of cognitive science, education, and physical and life sciences are helping chemical education researchers to study the instructional uses of visualization techniques, particularly visualization and animation of the particulate state of matter. These collaborations reveal how students perceive and interpret various kinds of multimedia presentations and molecular animations and show how to develop design principles for creating and using effective chemistry visualizations. This paper describes how research studies on multimedia-based learning and molecular visualizations have changed o...
Whitman, Warren, and the Literature of Discovery

Examines Robert Penn Warren's responses to Whitman (especially Warren's poem "Empire") and argues that "it was Whitman against whom Warren
Research or Retrench: the teaching profession challenged

The editors welcome readers’ contributions in the form of letters about any aspect of physiology education. Please write to the Editor, Advances in Physiology Education, American Physiology Society...
Fine needle aspiration of gastrointestinal stromal tumors.

OBJECTIVE: Gastrointestinal stromal tumors (GISTs) are uncommon mesenchymal tumors of the gastrointestinal tract. Fine needle aspiration (FNA) is one option for diagnosing GISTs before surgery. This study was designed to evaluate the clinical utility of FNA in the diagnosis of GISTs. STUDY DESIGN: FNAs from 19 GISTs originating in the stomach, small bowel and colon obtained from 1988 to 1998 were studied. Immunocytochemistry was performed on 12 cases. The GISTs were classified as benign, borderline and malignant, according to location, size, mitotic activity and clinical outcome. RESULTS: Benign (three) and borderline (five) GISTs were all spindle cell type; malignant GISTs included five spindle cell type and six epithelioid type. Most smears contained abundant cellular material. Benign and borderline GISTs of spindle cell type tended to have cells arranged in tightly cohesive clusters, while malignant GISTs were more likely to exhibit loosely cohesive groups with many single cells, occasional nuclear pleomorphism, hyperchromasia and irregular nuclear contours. Epithelioid-type GISTs mimicked adenocarcinoma. Mitoses were seldom observed in either type. CD117 (KIT protein product) was demonstrated by immunocytochemistry in 9 cases, CD34 in 11, desmin in 3, S-100 protein in 2 and smooth muscle actin in 6 cases CONCLUSION: FNA can be used to diagnose GISTs as spindle cell and epithelioid types, but cytomorphology alone cannot be used to assess malignant potential. Immunocytochemical staining for CD117 is helpful in confirming the diagnosis. Care must be taken to differentiate epithelioid-type GISTs from adenocarcinoma.
How methanol affects the surface of blue and red emitting porous silicon

The effects of liquid methanol on the photoluminescence intensity and FTIR spectra of red and blue emitting porous silicon were investigated. Hydrogen passivated red emitting samples exhibit quenching and recovery of photoluminescence intensity and broadening of the Si‐Hx stretch bands upon exposure to liquid methanol. Oxygen passivated red emitting samples exhibit no photoluminescence quenching. The sensitivity of the red emitting sample is due to the microstructure of porous silicon at the surface and the ability of methanol to penetrate the pores. The blue photoluminescence of thermally oxidized samples is quenched upon exposure to methanol. This is attributed to the solvent’s ability to change the surface passivation which modifies existing traps and introduces competitive recombination channels for electrons.
Texture in stainless steel welds: an ultrasonic study

We studied texture effects in five AISI-316 stainless-steel welds. We measured nine independent ultrasonic velocities along the weld's principal axes. These velocities reveal a strong texture different from the 〈0 0 1〉 fibre-type usually attributed to these materials The texture is independent of delta-ferrite content and must contain a strong 〈110〉 component related to the f c c monocrystal elastic constantC′=(C11−C12)/2. A postulated ideal (0 0 1) [1 1 0] plate-type texture explains the range of measured longitudinal and transverse sound velocities, but not their detailed values.
Matrices in analogue mathematical machines

Abstract This paper initiates a rational account of the methods of solution of linear differential equations on electronic analogue machines from the matrix point of view. The 1-to-1 reciprocal correspondence between the mathematical problem matrices and the electronic synthesis networks is established. The systematic matrix viewpoint bearing on both the mathematical and physical systems yields theoretical and practical advantages, most of which remain to be exploited.
Just Be There: Campus, Department, Classroom…and Kitchen?

As learners and information users are changing, so must library services. Meeting user needs and expectations is a priority within the academic library experience. Embracing a proactive approach to library service is necessary in order to be successful and relevant in the academic environment. Breaking out of the stereotypical librarian mold, this profile of one academic library's embedded librarian program can offer insight into a tiered strategy targeting the campus, department, and classroom.
Postprandial oxidative stress is exacerbated in cigarette smokers.

Both cigarette smoking and high fat meals induce oxidative stress, which is associated with the pathogenesis of numerous diseases. We compared blood antioxidant status, oxidative stress biomarkers and TAG in twenty smokers and twenty non-smokers, matched for age and physical activity, in response to a high fat test meal standardized to body mass. Blood samples were collected before feeding (resting and fasted) and at 1, 2, 4 and 6 h post feeding and analysed for antioxidant capacity (trolox equivalent antioxidant capacity; TEAC), xanthine oxidase activity (XO), hydrogen peroxide (H2O2), malondialdehyde (MDA) and TAG. Smoking status (P 0.05), contrasts revealed greater values in smokers compared with non-smokers for XO, H2O2, MDA and TAG, and lower values for TEAC at times from 1-6 h post feeding (P < or = 0.05). Our findings indicate that young cigarette smokers experience an exaggerated oxidative stress response to feeding, as well as hypertriacylglycerolaemia, as compared with non-smokers. These data provide insight into another possible mechanism associating cigarette smoking with ill health and disease.
Applications of deuterium labeling in the study of the in vitro conversion of Δ1‐pyrroline to 4‐aminobutanoic acid and 2‐pyrrolidinone

delta 1-Pyrroline is a putrescine metabolite that is biotransformed by rabbit liver preparations to 4-aminobutanoic acid and its lactam, 2-pyrrolidinone. Analysis of dilute aqueous solutions of delta 1-pyrroline by proton nuclear magnetic resonance indicated the the predominating species in the liver incubation preparations was delta 1-pyrroline monomer, although other species, such as 4-aminobutyraldehyde an delta 1-pyrroline timer, may exist in equilibrium with the monomer. [2H12]-delta 1-Pyrroline trimer was synthesized from [2H5]pyrrolidine by conversion to the N-chloro derivative followed by dehydrohalogenation. 4-Aminobutanoic acid was measured by a gas chromatographic mass spectrometric assay after derivatization with dimethylformamide dimethyl acetal. The 4-aminobutanoic acid homologue, 5-aminovaleric acid, served as internal standard. 2-Pyrrolidinone was hydrolyzed and measured as 4-aminobutanoic acid. A comparison of the amounts of product formed following incubation of labeled and unlabeled delta 1-pyrroline indicated a significant isotope effect in the formation of 2-pyrrolidinone. The influence of the label was much less on 4-aminobutanoic acid production. The results suggest that there are two separate pathways involved in the reaction.
Collaborative resource exchanges for peer-to-peer video streaming over wireless mesh networks

Peer-to-peer collaboration paradigms fundamentally change the passive way wireless stations currently adapt their transmission strategies to match available resources, by enabling them to proactively influence system dynamics through exchange of information and resources. In this paper, we focus on delay-sensitive multimedia transmission among multiple peers over wireless multi-hop enterprise mesh networks. We propose a distributed and efficient framework for resource exchanges that enables peers to collaboratively distribute available wireless resources among themselves based on their quality of service requirements, the underlying channel conditions, and network topology. The resource exchanges are enabled by the scalable coding of the video content and the design of cross-layer optimization strategies, which allow efficient adaptation to varying channel conditions and available resources. We compare our designed low complexity distributed resource exchange algorithms against an optimal centralized resource management scheme and show how their performance varies with the level of collaboration among the peers. We measure system utility in terms of the multimedia quality and show that collaborative approaches achieve ~50% improvement over non-collaborative approaches. Additionally, our distributed algorithms perform within 10% system utility of a centralized optimal resource management scheme. Finally, we observe 2-5 dB improvement in decoded PSNR for each peer due to the deployed cross-layer strategy
Modeling the effects of fire and climate change on carbon and nitrogen storage in lodgepole pine (Pinus contorta) stands

The interaction between disturbance and climate change and resultant effects on ecosystem carbon (C) and nitrogen (N) fluxes are poorly understood. Here, we model (using CENTURY version 4.5) how climate change may affect C and N fluxes among mature and regenerating lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Wats.) stands that vary in postfire tree density following stand-replacing fire. Both young (postfire) and mature stands had elevated forest production and net N mineralization under future climate scenarios relative to current climate. Forest production increased 25% [Hadley (HAD)] to 36% [Canadian Climate Center (CCC)], compared with 2% under current climate, among stands that varied in stand age and postfire density. Net N mineralization increased under both climate scenarios, e.g., + 19% to 37% (HAD) and + 11% to 23% (CCC), with greatest increases for young stands with sparse tree regeneration. By 2100, total ecosystem carbon (live + dead + soils) in mature stands was higher than prefire levels, e.g., + 16% to 19% (HAD) and + 24% to 28% (CCC). For stands regenerating following fire in 1988, total C storage was 0-9% higher under the CCC climate model, but 5-6% lower under the HAD model and 20-37% lower under the Control. These patterns, which reflect variation in stand age, postfire tree density, and climate model, suggest that although there were strong positive responses of lodgepole pine productivity to future changes in climate, C flux over the next century will reflect complex relationships between climate, age structure, and disturbance-recovery patterns of the landscape.
X-ray bright points and the solar cycle

Soft X-ray filtergrams show the presence on the Sun of large numbers of small, closed regions of coronal emission. These features, called 'X-ray bright points' correspond to small, short-lived regions of emerging magnetic flux. As a function of size or lifetime they form a broad spectrum of activity which is continuous with the active regions. The shape of the Sun's activity spectrum is such that most of all magnetic flux emerging at the surface comes in the form of bright points. From this viewpoint, active regions may be viewed as the long lifetime tail end of the bright point spectrum. Examination of soft X-ray data obtained from 1970 to 1978 shows that the number of bright points appears to be anticorrelated with traditional activity indices such as sunspot number; the anticorrelation persists after corrections are made for obscuration by active regions. Comparison of X-ray data with KPNO magnetograms shows that to within a factor of 2, the average total amount of magnetic flux emerging over the full Sun is constant through the entire period of observation. The solar cycle therefore appears to be more an oscillation in the wavenumber distribution of emerging flux than of the total quantity of magnetic flux produced.
RARE imaging of PCr in human forearm muscles.

Rapid acquisition with relaxation enhancement (RARE) sequences have been used to map the 31P phosphocreatine (PCr) signal in human forearms at 4.7 T. Signal-to-noise levels of approximately 10 were achieved from the major muscle groups in 5.5-minute scan times with a spatial resolution of 4 × 2 × 2 cm3. Exercise caused demonstrable reductions in PCr signal from activated muscles, which correlated with affected muscle groups in T2-weighted proton images. RARE imaging of the PCr signal at 4.7 T is feasible and, with technically achievable improvements in signal-to-noise ratio, should prove useful in studying energy metabolism in muscle and other organs.
“I vote, therefore I am:” Rituals of Democracy and the Turkish Chief Rabbi

This article describes how the election and investiture of a chief rabbi in 2002 created a unique space for Turkish Jews to debate the meaning of democracy. I document current Turkish Jewish discourses about democracy by combining ethnographic observations of the election season with an analysis of the production and reception of local narratives (speeches, news articles, and interviews) about the process. I then analyze the election and inauguration as a “politics of presence” in which democracy is seen not only as a practice through which to debate ideas but a discursive move to represent collective difference in the public sphere. As such, this article contributes to discussions about the performative nature of minority politics and how these alternative discursive spheres relate to the broader contexts in which they occur.
Single Ping-multiple measurements: sonar bearing angle estimation using spatiotemporal frequency filters

Presented is a mixed-signal full-custom VLSI chip designed to receive sonar return signals from an ultrasonic microphone array, and extract input bearing angles of the incoming signals. Processing utilizes simple low-power analog spatiotemporal bandpass filters to extract wavefront velocity across the array, which translates to input bearing angle. Processing uses phase information of array signals, not onset or offset of ultrasonic burst. With such synchronous processing, multiple angle readings from different returns of the same ultrasonic transmit burst are possible. Compatible microphone arrays are compact in size-test array has a total baseline of 26.5 mm. In a test with ultrasonic beacon 65 cm from a microphone array, angular precision of 1/spl deg/ was demonstrated in most instances in the range -60/spl deg/ to 60/spl deg/. Applications include sonar localization of remote objects, sonar imaging, and improved interference rejection between objects within the field of view of the sensor microphones. The chip was fabricated on a standard 3M2P CMOS process with a 0.5-/spl mu/m feature size.
A Possible Hemoglobin Marker of Alcoholism

Human erythrocytes were found to synthesize 5-deoxy-D-xylulose1-phosphate from added acetaldehyde and endogenous dihydroxyacetone phosphate. In separate experiments 5-deoxy-D-xylulose-l-phosphate was observed to react with hemoglobin Ao, forming a stable adduct. Formation and accumulation of this unique form of hemoglobin in the blood of alcohol users, by integrating the blood acetaldehyde concentration, would provide a dose-time record of alcohol consumption.
Poetry, Prophecy, Hermeneutic: Recent Studies in Isaiah

There is seldom a lack of new studies of Isaiah. In this article I want to mention some aspects of a few recently published studies which direct our attention in different ways to the book of Isaiah, rather than to Isaiah of Jerusalem (or the so-called ‘second Isaiah’) as an individual with an historical role. Not that I am not concerned with the historical Isaiah of Jerusalem: in fact the concern is greater than the following reviews might suggest. Positively I am insisting that our quest for him must start from the book of Isaiah in all its variety and complexity, and not from its few familiar and congenially informative prose sections. Then the more negative suggestion that Isaiah may not have been a ‘prophet’ (at least in the sense that tradition came to regard him) is an attempt to clear the ground for a better point of view.
Making fast buffer insertion even faster via approximation techniques

As technology scales to 0.13 micron and below, designs are requiring buffers to be inserted on interconnects of even moderate length for both critical paths and fixing electrical violations. Consequently, buffer insertion is needed on tens of thousands of nets during physical synthesis optimization. Even the fast implementation of van Ginneken's algorithm requires several hours to perform this task. This work seeks to speed up the van Ginneken style algorithms by an order of magnitude while achieving similar results. To this end, we present three approximation techniques in order to speed up the algorithm: (1) aggressive pre-buffer slack pruning, (2) squeeze pruning, and (3) library lookup. Experimental results from industrial designs show that using these techniques together yields solutions in 9 to 25 times faster than van Ginneken style algorithms, while only sacrificing less than 3% delay penalty.
Student difficulties with basic concepts in introductory materials science engineering

We report on findings of a project to identify specific student difficulties in a university-level introductory materials science course for engineers. This is the first part of a larger project to design and assess evidence-based curricular materials for this course. Through interviews, testing, and classroom observation of over 1000 students, we examined in detail student understanding of basic topics in materials science including topics such as atomic structure, mechanical properties, defects, diffusion, phase diagrams, failure, and the processing of metals. We identified four general areas in which students have difficulties: Student confusion of similar concepts, student difficulties with reasoning about concepts with more than one variable, student use of inappropriate models or analogies, and student difficulties with common graphs and diagrams used in materials science. We provide a number of specific examples of each category, focusing on the materials science of metals. While these student difficulties are interesting in their own right, a careful examination of these difficulties can also provide useful information for the design of instructional materials.
Controller-agnostic SDN Debugging

Complexity in software-defined network (SDN) applications calls for methods and tools that can facilitate comprehensive debugging and analysis. A key challenge in this regard is that SDN configurations interact with network devices that can behave in unexpected ways, depending on factors such as traffic and application mix. In this paper, we describe OFf, a debugging and test environment for SDN developers. OFf is built on top of the fs-sdn simulator, which was developed to offer simple-to-use, accurate and scalable evaluation of OpenFlow-based SDN configurations. OFf offers standard debugging features for controller applications such as stepping, breakpoints, and watch variables. It also offers features that provide visibility into network behavior including packet tracing, packet replay and visualization features, and alerts that are triggered when, e.g., configurations change. OFf is accessed through a text interface and is designed to interoperate with any standard SDN controller platform. We demonstrate the capabilities of OFf through three test scenarios that illustrate its utility and modest performance impact on running applications. Specifically, we show how OFf can be used to analyze and fix bugs in a traffic engineering application, and to detect and repair a security vulnerability due to multiple application interaction and unexpected rule expiration.