cssi/SciSciGPT-SciSciNet huggingface dataset:
Unified measurement of observer performance in detecting and localizing target objects on images

In this paper methods used to measure observer performance are reviewed, and a simple general model for finding and reporting target objects in gray-scale image backgrounds is presented. That model provides the basis for a combined measurement of detection and localization performance in various image-interpretation tasks, whether by human observers or by realized computer algorithms. The model assumes that (1) an observer's detection response and first choice of target location both depend on the "maximally suspicious" finding on an image, (2) a correct (first-choice) localization of the actual target occurs if and only if its location is selected as the most suspicious, and (3) a target's presence does not alter the degree of suspicion engendered by any other (normal) image findings. Formalization of these assumptions relates the ROC curve, which measures the ability to discriminate between images containing targets and images without targets, to the "Localization Response" (LROC) curve, which measures the conjoint ability to detect and correctly localize the actual targets in those images. A maximum-likelihood statistical procedure, developed for a two-parameter "binormal" version of this model, concurrently fits both the ROC and LROC curves from an observer's image ratings and target localizations for a set of image interpretations. The model's application is illustrated (and compared to standard ROC analysis) using sets of rating and localization data from radiologists asked to search chest films for pulmonary nodules. This model is then extended to multiple-report ("free-response") interpretations of multiple-target images, under the stringent requirement that an observer's detection capability and criterion for reporting possible targets both remain stationary across images and across the successive reports made on a given image. That extended model yields formulations and predictions for the so-called "Free-Response" (FROC) curve, and for a recently proposed "Alternative FROC" (AFROC) curve. Tests of that model's "stationarity" assumptions are illustrated using radiologists' free-search interpretations of chest films for pulmonary nodules, and they suggest that human observers may often violate those assumptions when making multiple-report interpretations of images.
Period-doubling route to chaos in a semiconductor laser with weak optical feedback.

We report experimental and theoretical observations of a period-doubling route to chaos in a semiconductor laser with optical feedback. Increasing the feedback produces a quasiperiodic route to chaos, manifested as a catastrophic increase in the laser linewidth. Under certain conditions, frequency locking occurs in preference to quasiperiodicity, and then period doubling appears. Both phenomena are explained as interactions between the external cavity modes and the laser relaxation oscillations.
Transient picosecond Raman studies of electron and hole velocity overshoots in a GaAs-based p-i-n semiconductor nanostructure

We report the observation of a velocity overshoot phenomenon for electrons as well as holes in a GaAs-based p–i–n nanostructure by using transient picosecond Raman spectroscopy. Under the picosecond laser excitation, we have found that the extent of velocity overshoot for electrons is comparable to that of holes. These experimental results have been explained in terms of various carrier scattering processes. Comparisons with results obtained from other III–V semiconductors are also made and a comprehensive discussion is given.
Recursion principles for syntax with bindings and substitution

We characterize the data type of terms with bindings, freshness and substitution, as an initial model in a suitable Horn theory. This characterization yields a convenient recursive definition principle, which we have formalized in Isabelle/HOL and employed in a series of case studies taken from the λ-calculus literature.
Abstract 5274: Wnt inhibitory factor 1 reduces the growth and migration of human adenoid cystic carcinoma cells

Background: Adenoid cystic carcinoma (ACC) is a common malignancy that arises in major and minor salivary glands. It is well characterized by relatively high rate of local recurrence, and late onset of distant metastases, which cause high morbidity and mortality. Dysregulation in the Wingless-type (Wnt)/β-catenin pathway contributes to many human tumors. Here, we report that downregulation of an important Wnt antagonist, Wnt inhibitory factor 1 (WIF1), promotes ACC cell proliferation and migration. Aims: To determine the status of WIF1 and study the effects of WIF1 on human adenoid cystic carcinoma cell growth, migration, spheroid formation and senescence. Methods: Genomic DNA isolated from human adenoid cystic carcinoma cell lines (ACC52 and ACC112) was used for methylation-specific PCR after bisulfite modification. ACC52 and ACC112 cells were treated with a demethylating agent, 5-aza-2′-deoxycytidine (DAC) [50 µM for 4 days], and used for total RNA isolation and real-time RT-PCR to determine WIF1 mRNA expression. To determine the growth suppressive effects of WIF1, ACC52 and ACC112 cells were transiently transfected with either pCI blast (vector) or pCI blast-WIF1 and assessed for cell proliferation, migration, spheroid formation and senescence. Cell proliferation was determined at different time intervals (24, 48, 72 h) by hexosaminidase assay. Cell migration and spheroid formation were assessed by scratch assay and soft agar assay, respectively. Cellular senescence was determined using senescence β-galactosidase staining kit. Results: Methylation-specific PCR demonstrate that WIF1 is silenced by promoter methylation in ACC cells. DAC treatment increased the WIF1 mRNA expression by 2.3-fold and 3.8-fold in ACC52 and ACC112 cells, respectively compared with vehicle treatment. WIF1 significantly decreased the proliferation and migration of adenoid cystic carcinoma cells. Additionally, WIF1 significantly decreased the number of spheroids formed at 7 and 17 days. Furthermore, WIF1 induced a remarkable increase in cellular senescence in both the cell lines. Conclusions: We demonstrate that WIF1 is downregulated by promoter hypermethylation in human adenoid cystic carcinoma cells. Importantly, WIF1 inhibited the cell growth, migration and cancer stemness, while inducing cellular senescence. Our findings suggest that WIF1 is a potent growth inhibitor of adenoid cystic carcinoma cells and therefore could be a potential therapeutic agent for ACC. Grant support: This work was supported by the Adenoid Cystic Carcinoma Research Foundation (LQ). LQ holds a Presbyterian Health Foundation Endowed Chair in Otorhinolaryngology. Citation Format: Ilangovan Ramachandran, Vengatesh Ganapathy, Lurdes Queimado. Wnt inhibitory factor 1 reduces the growth and migration of human adenoid cystic carcinoma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5274. doi:10.1158/1538-7445.AM2014-5274
Analysis of crosslinking in amine-cured epoxy systems : the one-to-one relationship between Tg and conversion

Network formation, in a system such as a tetrafunctional aromatic diamine cured with a difunctional epoxy, is considered on the basis of only interconnected trifunctional crosslinking sites. The number-average molecular weight, the crosslinking density, and the gel point, and also the vitrification contours of the time—temperature—transformation (TTT) isothermal cure diagram, are related to the ratio of the reaction rate constants, k2/k1, of the competing reactions of epoxy with secondary amine group (k1) and with primary amine group (k1). It is considered that the glass transition temperature, Tg, is related uniquely to conversion on the basis that the number-average molecular weight and crosslinking density are insensitive to the ratio, k2/k1. Experimental data support the theoretical result. The potential influences of chemical structure and physical aging on Tg are discussed. © 1992 John Wiley & Sons, Inc.
National Symbols and National Identity: Currency and Constructing Cosmopolitans in Tunisia

This article examines the imagery on Tunisian banknotes and its role in constructing a state-sponsored vision of Tunisian national identity. In addition to analyzing the currency itself, the article embeds the symbols used on the money in a social and historical context by looking at other public uses of the historical figures pictured and drawing on ethnographic work conducted in Tunisia. The article suggests that the banknotes must be seen as part of a larger discourse about the nature of Tunisian identity. In particular, this discourse focuses on Tunisia as a cosmopolitan nation that is open to the modern world and posits that this openness is rooted in its history. Although the currency suggests the co-presence of modernity and tradition, tradition is relegated to the rural margins while the urban centers are celebrated as the modern future. Beyond looking at the historical figures represented, the article examines historical absences. Most notably, there are no pre-modern Arab figures on the banknote...
Integral equation and sensitivity analyses of creep behavior for PVDF thin films

Abstract This paper presents an analytic study of a linear viscoelasticity constitutive equation involving stress, strain and creep compliance while simultaneously correcting a previously reported investigation [Vinogradov, A.M., Schmidt, V.H., Tuthill, G.F., Bohannan, G.W., (2004). Damping and electromechanical energy losses in the piezoelectric polymer PVDF. Mechanics of Materials 36, 1007–1016]. The constitutive equation is presented as a linear, weakly-singular Volterra integral equation of the second kind in the stress variable. An analytic solution is developed, using the Laplace transform technique, for acquiring the stress history based on a specified creep compliance function and input strain. The time-dependent stress solution is expressed in terms of an infinite series involving the provided strain history. An example is studied involving constant strain input. This example permits an aposteriori error estimate for the stress based on the truncated series. Finally, a novel first-order sensitivity analysis is presented to assist in developing experiments for estimating the parameters associated with the compliance function. Using the proposed first-order sensitivity analysis, it is possible to investigate how the uncertainty associated with these parameters propagate into the stress history.
Evidence for active normal faulting on 5.9 Ma crust near Hole 504B on the southern flank of the Costa Rica rift

Single-channel and multichannel seismic reflection data show evidence for recent movement of faults on 5.9 Ma crust near Ocean Drilling Program (ODP) Hole 504B on the southern flank of the Costa Rica rift, >200 km from the ridge axis. These faults, which are associated with N85°W-trending, ridge-parallel basement escarpments, can be traced upward into the thick, overlying sedimentary section that blankets volcanic crust in this area. The offset of sedimentary horizons indicates the style and history of faulting. It consistently shows the downdropped side to the north, signifying inward-facing normal faults or grabenlike structures indicative of crustal extension perpendicular to the ridge axis. Although most of the movement on these faults appears to have occurred in young crust near the ridge axis, many of these faults have a long history of activity, with cumulative displacements of several tens of metres occurring over the past several million years. These results are inconsistent with inferences from borehole stress measurements made in Hole 504B that the crust in this area is in horizontal compression or with previous assumptions that crustal extension at mid-ocean ridges is limited to within 10–20 km of the spreading axis. Although the broad zone of crustal extension on the south flank of the Costa Rica rift could reflect anomalous stresses within the Nazca plate, several independent lines of evidence suggest that the active “tectonic zone” of crustal extension and normal faulting at mid-ocean ridges may be significantly wider than previously suspected.
The LARK RNA-Binding Protein Selectively Regulates the Circadian Eclosion Rhythm by Controlling E74 Protein Expression

Despite substantial progress in defining central components of the circadian pacemaker, the output pathways coupling the clock to rhythmic physiological events remain elusive. We previously showed that LARK is a Drosophila RNA-binding protein which functions downstream of the clock to mediate behavioral outputs. To better understand the roles of LARK in the circadian system, we sought to identify RNA molecules associated with it, in vivo, using a three-part strategy to (1) capture RNA ligands by immunoprecipitation, (2) visualize the captured RNAs using whole-genome microarrays, and (3) identify functionally relevant targets through genetic screens. We found that LARK is associated with a large number of RNAs, in vivo, consistent with its broad expression pattern. Overexpression of LARK increases protein abundance for certain targets without affecting RNA level, suggesting a translational regulatory role for the RNA-binding protein. Phenotypic screens of target-gene mutants have identified several with rhythm-specific circadian defects, indicative of effects on clock output pathways. In particular, a hypomorphic mutation in the E74 gene, E74(BG01805), was found to confer an early-eclosion phenotype reminiscent of that displayed by a mutant with decreased LARK gene dosage. Molecular analyses demonstrate that E74A protein shows diurnal changes in abundance, similar to LARK. In addition, the E74(BG01805) allele enhances the lethal phenotype associated with a lark null mutation, whereas overexpression of LARK suppresses the early eclosion phenotype of E74(BG01805), consistent with the idea that E74 is a target, in vivo. Our results suggest a model wherein LARK mediates the transfer of temporal information from the molecular oscillator to different output pathways by interacting with distinct RNA targets.
Effect of a β-lactamase inhibitor, tazobactam, on growth and penicillin-binding proteins of Borrelia burgdorferi

The effects of tazobactam, a relatively new beta-lactamase inhibitor, were investigated on growth and penicillin-binding proteins (PBPs) of Borrellia burgdorferi. A previous communication from our group demonstrated several proteins capable of binding labelled penicillin in this organism. Of these proteins, 94-kDa and 57-kDa PBPs possessed the highest affinity for penicillin and were assumed to be essential proteins involved in cell-wall synthesis. In these experiments, tazobactam was used in competition binding experiments as well as on whole spirochetes. Only the 94-kDa and 57-kDa PBPs were affected by increasing amounts of tazobactam during competition-binding experiments and growth of B. burgdorferi was also inhibited. These results may explain the in vitro activity of beta-lactamase inhibitors in general and suggest a utility for these compounds when examining PBPs with hydrolysing activity and/or organisms with beta-lactamases.
Numerical Study of Transport and Reaction Phenomena in GaN Vapor Phase Epitaxy

A vapor phase epitaxy (VPE) system has been designed to grow high quality gallium nitride layers under the deposition temperature of 990°C and the pressure range of 200–800 Torr. For the better understanding of the deposition mechanism of GaN layers, a numerical model that is capable of describing multi-component fluid flow, gas/surface chemistry, conjugate heat transfer, thermal radiation, and species transport, has been developed to help in design and optimization of the epitaxy growth system. The vacuum area between heaters and reactor tube is simulated as a solid body with small thermal conductivity and totally transparent to radiative heat transfer. Simulation results were compared to the experimental data to examine the temperature distribution achieved inside the growth reactor. To optimize operating parameters, the reaction mechanism for GaN in the VPE system has been identified, and the comprehensive computational simulations have been performed to study the temperature distribution, species mixing process, ammonia decomposition process and GaN deposition rate distribution on the substrate. Parametric studies have been performed to investigate the effects of operational and geometric conditions, such as temperature, reacting/carrier gas flow rate and distance between the substrate and the nozzle, on species mixing process and GaN deposition uniformity. The relationship between gas flow rate and III/V ratio achieved on the substrate will be established.Copyright © 2005 by ASME
Preparation and some properties of porous alumina ceramics obtained by the gelatination of ammonium alginate

This study was carried out to develop a new preparation process of porous alumina ceramics and to examine their porous properties. The gelatination of ammonium alginate by hydrochloric acid was used for the formation of a gel-like precursor composed of alumina particles and alginic polymer. By this simple chemical shaping process of green bodies, porous alumina ceramics with a very sharp pore size distribution and a porosity of 40 to 55% could be obtained after firing at 1000 to 1600°C. The porosity showed an improvement of 15–20% compared with that of porous materials prepared from conventional procedures such as the pressing and slip-casting methods. The optimum concentrations of ammonium alginate and hydrochloric acid were 0.3–2.0 wt% and over 0.1 n, respectively, from the standpoint of the mixing treatment of raw materials and the gelatination.
Differential scanning calorimetry studies of NaCl effect on the inverse temperature transition of some elastin‐based polytetra‐, polypenta‐, and polynonapeptides

and (~-Val'-L-Pro~-L-Ala~-~-Val~-Gly~),; the polytetrapeptide (~-Val'-~-Pro~-Gly~-Gly~), and its more hydrophobic analogue ( ~-1le'~-Pro*-Gly~-Gly~),,; and the polynonapeptide (a pentatetra hybrid), (~-Val'-~-Pro~-G ly~~-Val~-Gly~-~-Val~-~-Pro~-Gly~-G ly~)~. Previous physical characterizations of the polypentapeptides have demonstrated the occurrence of an inverse temperature transition since increase in order of the polypentapeptide, as the temperature is raised from below to above that of the transition, has been repeatedly observed using different physical characterizations. In the present experiments, it is observed that the transition temperatures of the polypeptides studied are linearly dependent on NaCl concentration. The molar effectiveness of NaCl in shifting the transition temperature AT,/ [ N] , is about 14"C/[ N] , with the dependence on peptide hydrophobicity being fairly small. Interestingly, however, the 6AQ/ [ N] does depend on the hydrophobicity of a polypeptide.
Initiation of (−)-Strand RNA Synthesis Catalyzed by the BMV RNA-Dependent RNA Polymerase: Synthesis of Oligonucleotides

RNA replication, a process of fundamental importance for pathogenesis by many viruses, remains poorly understood at the mechanistic level because relatively few of the responsible enzymes have been purified and characterized biochemically. Partially purified RNA-dependent RNA polymerase (RdRp) from brome mosaic virus (BMV)-infected barley leaves is able to synthesize (-)-strand RNAs from input (+)-strand templates. In resolving RdRp products generated during (-)-strand BMV RNA synthesis, we found that an RNA of eight nucleotides was generated at approximately 10-fold molar excess to the full-length (-)-strand RNA. Production of the 8-mer was dependent upon and specific to BMV RNA templates. Furthermore, inhibitors of full-length (-)-strand RNA synthesis by RdRp also affected the production of the 8-mer. Analysis of the sequence of the 8-mer suggests that it is initiated at the authentic initiation site on the BMV RNA template, consistent with the possibility that the 8-mer is an abortive initiation product of RNA synthesis by RdRp in vitro. Addition of heparin or Mn2+ differentially affected production of the 8-mer and full-length (-)-strand RNA, as did some nucleotide changes near the site of RNA initiation. These studies further define the initiation process of (-)-strand RNA synthesis.
Immunocytochemical evidence for anti-LHRH and anti-ACTH activity in the "F" antiserum.

An antiserum which has previously been thought to be specific for LHRH- like immunoreactive material was shown to contain two populations of antibodies, one demonstrating anti-LHRH activity and the other anti -ACTH (1-24) activity. In rat and mouse, ACTH(1-4)-like immunoreactive substance is present in perikarya within the basal hypothalamus and in fibers in arcuate, periventricular and dorsomedial nuclei. LHRH-like immunoreactivity is present in fibers within the median eminence and arcuate nucleus, in a few fibers running along the ventral border of the hypothalamus, and in a small number of cell bodies within the medial basal hypothalamus.
Efficacy of venovenous extracorporeal membrane oxygenation for neonates with respiratory and circulatory compromise.

We report a 12-month experience at Egleston Children's Hospital in Atianta, Ga., with a protocol under which venovenous extracorporeal membrane oxygenation (ECMO) was used instead of venoarterial ECMO. Fifty-five newborn infants were referred for ECMO, four of whom had disqualifying conditions (all four died). Thirty-one infants were supported without recourse to ECMO, one of whom died. Of the 20 remaining patients, three were placed on a venoarterial ECMO regimen because of our early uncertainty about the efficacy of venovenous ECMO or because of technical constraints. All other patients (n=17), including three with congenital diaphragmatic hernia, were supported with venovenous perfusion. No patient begun on a venovenous ECMO regimen required conversion to venoarterial bypass. Before ECMO, venovenous patients required an average dopamine dose of 16 μ g/kg per minute and an average dobutamine dose of 6 μ g/kg per minute. Of 15 patients studied before ECMO, three had significantly impaired contractility, and all had evidence of pulmonary hypertension on an echocardiogram. Mean blood pressure did not change while heart rate fell from 172 to 146 beats/min during the first 2 hours of ECMO and vasoactive drug doses were reduced. Of the 17 venovenous ECMO patients, 15 (88%) survived. We conclude that neonatal patients with severe hypoxia and substantial circulatory compromise can be effectively supported by venovenous ECMO in most case.
The Essential Role of Medical Ethics Education in Achieving Professionalism: The Romanell Report

This article-the Romanell Report-offers an analysis of the current state of medical ethics education in the United States, focusing in particular on its essential role in cultivating professionalism among medical learners. Education in ethics has become an integral part of medical education and training over the past three decades and has received particular attention in recent years because of the increasing emphasis placed on professional formation by accrediting bodies such as the Liaison Committee on Medical Education and the Accreditation Council for Graduate Medical Education. Yet, despite the development of standards, milestones, and competencies related to professionalism, there is no consensus about the specific goals of medical ethics education, the essential knowledge and skills expected of learners, the best pedagogical methods and processes for implementation, and optimal strategies for assessment. Moreover, the quality, extent, and focus of medical ethics instruction vary, particularly at the graduate medical education level. Although variation in methods of instruction and assessment may be appropriate, ultimately medical ethics education must address the overarching articulated expectations of the major accrediting organizations. With the aim of aiding medical ethics educators in meeting these expectations, the Romanell Report describes current practices in ethics education and offers guidance in several areas: educational goals and objectives, teaching methods, assessment strategies, and other challenges and opportunities (including course structure and faculty development). The report concludes by proposing an agenda for future research.
Synthesis and molecular structure of the μ-acetyl complex Cp(CO)2Mo(μ-OCCH3)(μ-PPh2)FeCp(CO)

Abstract Reaction of Cp(CO)2FePPh2 with CH3MoCp(CO)3 gives the new μ-acetyl and μ-hydride complexes Cp(CO)2Mo(μ-OCCH3)(μ-PPh2)FeCp(CO) (2) and Cp-(CO) Fe (μ-H)(μ-PPh2)MoCp(CO)2 (3) in modest yields. Both complexes have been spectroscopically characterized with 3 further defined by an X-ray diffraction study: P21/c, a 8.552(2), b 31.052(9), c 9.681(4) A, β 104.02(3)0, V 2500(1) A3, Z = 4, R = 0.034, Rw = 0.038 for 3800 reflections with F0 ⪢ 3σ(F0). Complex 2 possesses a bridging acetyl ligand with carbon bound to Fe and oxygen bound to Mo. Both spectroscopic and structural data imply considerable oxycarbenoid character in this ligand. The μ-hydride ligand in complex 3 is not acidic and cannot be removed by KOH/EtOH or Na[N{SiMe3}2].
Quantifying degeneration of white matter in normal aging using fractal dimension

Although degeneration of brain white matter (WM) in aging is a well-recognized problem, its quantification has mainly relied on volumetric measurements, which lack detail in describing the degenerative adaptation. In this study, WM structural complexity was evaluated in healthy old and young adults by analyzing the three-dimensional fractal dimension (FD) of WM segmented from magnetic resonance images of brain. FDs detected in the old were significantly smaller than in the young subjects. Specifically, WM interior structure complexity degenerated in the left hemisphere in old men but in the right hemisphere in old women. Men showed more complex WM patterns than women. An asymmetrical (right-greater-than-left-hemisphere) complexity pattern was observed in the interior and general structures of WM, yet the surface complexity was symmetrical across WM structures of the two hemispheres. WM volumes were also measured, but no significant decline was found with aging. These results suggest that the deterioration of WM complexity is not uniformly distributed between the genders and across brain hemispheres.
Electronic Basis of the Strength of Materials

This 2003 book relates the complete set of strength characteristics of constituent atoms to their electronic structures. These relationships require knowledge of both the chemistry and physics of materials. The book uses both classical and quantum mechanics, since both are needed to describe these properties, and begins with short reviews of each. Following these reviews, the three major branches of the strength of materials are given their own sections. They are: the elastic stiffnesses; the plastic responses; and the nature of fracture. This work will be of great value to academic and industrial research workers in the sciences of metallurgy, ceramics, microelectronics and polymers. It will also serve well as a supplementary text for the teaching of solid mechanics.
Growth and nutrition of mycorrhizal guayule plants

SUMMARY Synthesis of mycorrhiza in guayule plants was achieved by inoculation of 8-day-old seedlings with hyphae and chlamydospores of an undescribed Glomus species. There was a five-fold increase in total dry weight of 30-day-old mycorrhizal- compared to nonmycorrhizal-guayule grown in sterile loamy-sand without additional fertiliser. Thirty-day-old, inoculated- and uninoculated-seedlings were transplanted to sterile or unsterile soil and grown an additional 60 days. The greatest total dry weight of guayule was attained by inoculated transplants grown in sterile soil. Inoculated transplants increased two- to three-fold in total dry weight compared to uninoculated transplants, both grown in unsterile soil. After 90 days, uninoculated plants grown in unsterile soil had formed mycorrhizae with resident vesicular-arbuscular mycorrhizal fungi to the same extent as inoculated-plants grown in unsterile soil. Total mineral uptake increased in inoculated guayule, irrespective of soil treatment or the presence of resident VA mycorrhizal fungi.
The development of a novel mouse model of transient global cerebral ischemia.

A reproducible model of global cerebral ischemia in mice is essential for elucidating the molecular mechanism(s) of neuronal damage induced by cerebral ischemia/reperfusion injury. In the present study, we developed a mouse model of transient global ischemia induced by occlusion of the bilateral common carotid arteries and the left subclavian artery together with right subclavian artery (RSA) stenosis (CSOSS) under controlled ventilation in C57BL/10ScSn mice. The mean arterial blood pressure was maintained in the physiological range. The cortical cerebral blood flow was reduced to less than 10% of the pre-ischemic value. Twelve minutes of global ischemia induced brain damage in several brain structures. The neuropathological score in the hippocampus CA1 region was 1.7, 3.5 and 3.7 following reperfusion for 24, 48 and 72 h, respectively. Less extensive damage was seen in the dentate gyrus and cortical regions, compared with the CA1 region. Damage was observed in these regions 24 h after ischemia and was not different between 48 and 72 h post-ischemia. Results indicated that this global ischemia model possessed several advantages, including reproducible cerebral ischemic insult, sufficient reperfusion and low mortality rate (10%), and could be used for studies on cerebral ischemia/reperfusion injury in mice.
Anti-GM1 ganglioside antibodies with differing fine specificities in patients with multifocal motor neuropathy.

Abstract Antibodies to gangliosides were detected in sera from three of 19 patients with chronic inflammatory polyneuropathy (CIP) by a thin-layer chromatogram overlay technique. All three of the patients fell into a clinical subset of the group that had multifocal motor neuropathy, and in all three patients the antibodies reacted with G M1 ganglioside. However, the fine specificities of the antibodies differed as demonstrated by cross-reactivity with different gangliosides in each of the three patients. The antibodies in patient 1 reacted with G M1 , G D1b , and asialo-G M1 suggesting that the terminal Gal(β1–3)GalNAc moiety that is common to these three glycolipids is an important part of the epitope(s). This was confirmed by showing reactivity of the antibodies with Gal(β1–3)GalNAc conjugated to bovine serum albumin. Patient 2 had antibodies that did not react with G D1b , but cross-reacted with G M2 ganglioside suggesting that the epitope(s) involved the inner portion of the oligosaccharide moiety that is shared between G M1 and G M2 . Patient 3 had antibodies that reacted with G M1 and asialo-G M1 , but they did not cross-react with either G D1b or G M2 . These results provide further evidence for a relationship between motor nerve syndromes and anti-G M1 antibodies and also suggest that G M1 could be a principal target antigen since other reactive gangliosides differed among the patients. However, the possible pathogenic effects of anti-G M1 antibodies on motor nerves remain to be established.
Assessing the Impact of Node Churn to Random Walk-Based Overlay Construction

Distributed systems desire to construct a random overlay graph for robustness, efficient information dissemination and load balancing. A random walk-based overlay construction is a promising alternative to generate an ideal random scale free overlay in distributed systems. However, a simple random walk-based overlay construction can be affected by node churn. Especially, the number of edges increases and the degree distribution is skewed. This inappropriate distortion can be exploited by malicious nodes. In this paper, we propose a modified random walk-based overlay construction supported by a logistic/trial based decision function to compensate the impact of node churn. Through event-driven simulations, we show that the decision function helps an overlay maintain the proper degree distribution, low diameter and low clustering coefficient with shorter random walks.
Anergic response to delayed hypersensitivity skin testing. A predictor of early mortality in heart transplant recipients.

Study objective We set out to determine if there is a significant difference in the morbidity and mortality between the anergic and reactive groups. Design A retrospective study of the heart transplant population was performed. Setting We studied the results of delayed hypersensitivity skin tests (DHSTs) in all cardiac transplant recipients at the Cleveland Clinic between May 1985 and November 1991 to determine whether DHST results were of prognostic significance. Results Preoperative skin testing was reactive to two or more antigens in 90 of the 127 patients whose DHSTs were interpretable, and the remainder were anergic. Anergic response was associated with increased bilirubin and decreased albumin levels, but gender, race, primary underlying heart disease, age at transplantation, creatinine level, hematocrit, glucose level, and ejection fraction were not related to anergy. Anergic patients had significantly higher mortality at 30, 60, and 90 days after transplantation, but long-term mortality was not significantly different from patients reactive on DHSTs (p = 0.267). Conclusion We conclude that the DHSTs provide useful information regarding risk of early mortality after heart transplantation
Magnetic superlattices and multilayers

We briefly review the active areas of current research in magnetic superlattices, emphasizing later years. With recent widening use of advanced technologies, more emphasis has been made on quantitative atomic level chemical and structural characterization. Examples where the multilayer structure has been controlled, characterized and correlated with the physical properties are discussed. The physical properties are categorized according to the complexity of a structure needed to observe a particular effect. We outline a number of general important unsolved problems, which could considerably benefit from theoretical and experimental input. An extensive list of magnetic multilayer materials is provided, with references to recent publications.
Precision of dual-energy x-ray absorptiometry: Development of quality control rules and their application in longitudinal studies

In research settings, longitudinal measurements of bone mineral density have become an integral part of the assessment of patients with metabolic skeletal disorders. To adequately utilize longitudinal measures, confidence in the long-term precision of the measurement technique must be very high. Dual-energy x-ray absorptiometry (DXA) has become commonly utilized in this context, and to better understand its long-term precision and to develop quality assurance protocols for its use, we examined the performance of eight DXA machines over a 3 year period. Anthropomorphic spine phantoms were measured frequently on each machine during the period of observation, and precision was estimated from the consistency of these determinations. Overall precision was excellent (mean longitudinal coefficient of variation, 0.4%). Nevertheless, by using a series of objective quality control criteria, small alterations in the performance of each machine were identified (mean number of changes, 4.6 in 3 years; mean magnitude, 0.0039 g/cm2, or 0.4%). The cumulative effects of those changes were sufficient to cause a significant (albeit minor) change in the regression slopes (phantom mineral density versus time) of most machines. The same quality control rules were also used to quantitate the magnitude of change and to adjust retrospectively machine performance during the period of observation, such that alterations were minimal and regression slopes were not significantly different from zero. Although the precision of DXA is excellent, alterations in machine function must be anticipated during longitudinal use. The development of quality control protocols provides the means to detect change objectively and to adjust for alterations in performance during the course of longitudinal evaluations.
The native, denatured and renatured states of deoxyribonucleic acid

The molecular characterization of the native, denatured and renatured forms of deoxyribose nucleic acid has been undertaken by means of sedimentation coefficient, S o , intrinsic viscosity, [ η ], and light-scattering measurements. For native DNA it is shown that S o is uniquely related to [ η ] over a thousandfold range of molecular weight: hence double-stranded DNA molecules form a homologous series independent of composition at least within practical limits. New and published data are analyzed to show that light-scattering determinations of molecular weight are uniformly reliable only below 3 million, and that the value of the Scheraga-Mandelkern constant β evidently remains very close to 2·4 × 10 6 throughout the molecular weight range of 200,000 to 200 million. The slight variation detected is consistent with theoretical predictions. As a result, either S o values or [ η ] values can be converted to molecular weights. Denatured DNA can be kept from aggregation at low ionic strengths and on this basis the dependence on molecular weight of S o and [ η ] have been established in solvents of two molarities, 0·195 M and 0·013 M . In the latter, the relations reflect base composition and degree of secondary structure. These molecular weight calibrations permit the molecular weight of DNA to be followed at elevated temperatures and thereby lead to estimates of the molecular weights of the strands in the native DNA. Hidden breaks are found with very low frequency (1 to 2 per 10 million molecular weight strand) in typical preparations of bacterial DNA. When corrections for these effects are introduced, the halving of the molecular weight upon denaturation can be observed, and the reasons for failing to observe this reproducibly in earlier work are now evident. The thermal degradation of circular, single-stranded ( φ X174 DNA offers another interesting application of the relations presented here. Renatured DNA, when prevented from aggregating, is shown to behave essentially like native DNA, the flexible single chains protruding from each end having relatively little effect.
Aspirin differentially affects thromboxane and prostacyclin production by trophoblast and villous core compartments of human placental villi.

Low-dose aspirin has been used as prophylactic treatment for preeclampsia and fetal growth retardation, but the physiologic mechanisms for the beneficial effect of this therapy are unknown. We studied the effects of aspirin on eicosanoid production by different compartments of normal term human placental villi. Duplicate parallel incubations (n = 7) of whole villi, villous core tissues, and trophoblast were established on Millicell platform dishes in minimum essential medium in the presence or absence of 1 × 10 -4 or 1 × 10 -5 mol/L aspirin. Production rates of thromboxane A 2 and prostacyclin were estimated by radioimmunoassay of their stable hydrolysis products, thromboxane B 2 and 6-keto-prostaglandin F 1α , respectively. Our results indicate that 1 × 10 -4 mol/L aspirin inhibits thromboxane production in whole villi and villous core tissues denuded of their trophoblast layer but not in isolated trophoblast cells. The same concentration of aspirin also inhibits prostacyclin production in the isolated villous core but not in whole villi and not in isolated trophoblast. We conclude that aspirin can selectively inhibit thromboxane production in whole placental villi and differentially affects thromboxane and prostacyclin production by the trophoblast and villous core compartments.
An intuitive approach to variation of parameters

Here is a discovery‐type proof of a strong theorem on variation of parameters. The theorem avoids any continuity assumptions on the given functions; and the proof uses little more than the definition of the Riemann integral.
In situ tribometry of solid lubricant nanocomposite coatings

The friction and wear behavior of nanocomposite coatings comprised of yttria stabilized zirconia (YSZ), Au, carbon and MoS2 were studied by in situ tribometry in both dry nitrogen (3–5% RH) and humid air (35–45% RH). Transfer film formation and interfacial dynamics were evaluated by direct observation of the sliding contact through a sapphire hemisphere. Four different third-body velocity accommodation modes (VAMs) were identified: (1) interfacial sliding, (2) interfacial sliding combined with transfer film shearing, (3) plowing and (4) local plowing and transfer film extrusion. The first two VAMs were associated with low, stable friction in dry and humid environments. The second two VAMs were associated with high friction in dry conditions and increased wear. Tribological performance and VAMs were also correlated with coating composition and mechanical properties. Friction spiking occurred for coatings with greater YSZ content. Harder coatings exhibited high friction run-in that was more pronounced for coatings with high carbon content. In situ experiments demonstrated that friction and wear performance was controlled by stable transfer film formation and VAMs associated with a lubricating condition (interfacial sliding or transfer film shearing). © 2007 Elsevier B.V. All rights reserved.
Solvent effect on second-sphere coordination of ferrioxamine B with substituted 18-crown-6 and 30-crown-10 crown ethers in dichloromethane as compared to chloroform

Abstract Stability constants for the second-sphere association of picrate and perchlorate salts of ferrioxamine B (FeHDFB+) with the substituted crown ethers (CE) 18-crown-6, cis-dicyclohexano-18-crown-6, benzo-18-crown-6, dibenzo-18-crown-6 and dibenzo-30-crown-10 were determined in dichloromethane and compared with corresponding data collected in chloroform. The stability of the supramolecular assembly {FeHDFB+,CE,X−} is increased in wet CH2Cl2 compared to wet CHCl3 by 0.21 to 0.74 log units. This represents a deviation from the expected trend of higher host–guest stability constants in a less polar solvent. The complexity of the molecular recognition process is discussed in the context of the role of the solvent in relation to the role of the cation and anion, and their hydration shells, and the crown ether structure, in determining the stability of the supramolecular assembly.
Regulation of Plasmodesmatal Permeability and Stomatal Patterning by the Glycosyltransferase-Like Protein KOBITO1

The differentiation of stomata provides a convenient model for studying pattern formation in plant tissues. Stomata formation is induced by a set of basic helix-loop-helix transcription factors and inhibited by a signal transduction pathway initiated by TOO MANY MOUTHS (TMM) and ERECTA family (ERf) receptors. The formation of a proper stomata pattern is also dependent upon the restriction of symplastic movement of basic helix-loop-helix transcription factors into neighboring cells, especially in the backgrounds where the function of the TMM/ERf signaling pathway is compromised. Here, we describe a novel mutant of KOBITO1 in Arabidopsis (Arabidopsis thaliana). The kob1-3 mutation leads to the formation of stomata clusters in the erl1 erl2 background but not in the wild type. Cell-to-cell mobility assays demonstrated an increase in intercellular protein trafficking in kob1-3, including increased diffusion of SPEECHLESS, suggesting that the formation of stomata clusters is due to an escape of cell fate-specifying factors from stomatal lineage cells. While plasmodesmatal permeability is increased in kob1-3, we did not detect drastic changes in callose accumulation at the neck regions of the plasmodesmata. Previously, KOBITO1 has been proposed to function in cellulose biosynthesis. Our data demonstrate that disruption of cellulose biosynthesis in the erl1 erl2 background does not lead to the formation of stomata clusters, indicating that cellulose biosynthesis is not a major determining factor for regulating plasmodesmatal permeability. Analysis of KOBITO1 structure suggests that it is a glycosyltransferase-like protein. KOBITO1 might be involved in a carbohydrate metabolic pathway that is essential for both cellulose biosynthesis and the regulation of plasmodesmatal permeability.
Small world, water coolers, and the challenge of remote collaboration

Ah, the water cooler. No other element of the office environment conjures up such visions of camaraderie and congeniality as does the water cooler (or its equivalent; when I worked in Italy, we chatted by---of course---the espresso machine). Often a centerpiece of cartoons and anecdotes, the water cooler has come to symbolize the social glue that holds our professional interactions together and helps the collaborative culture function. Around it we may temporarily drop the subject at hand and get to know one another as human beings.So how do we feel when a professional collaborative environment has no water cooler to facilitate the culture? What do we do? How do we develop relationships and come to trust our colleagues? Lada Gorlenko explores her reactions and what she decided to do about it, and urges us to accept the challenge for ourselves.---Elizabeth Buie
The Effects of Tuition Level and Financial Aid on the Demand for Undergraduate and Advanced Terminal Degrees.

Abstract This paper examines what is known about the effects of tuition level and financial aid on graduate enrollments and the stock of scholars with advanced terminal degrees. The demand for education is not defined in the traditional way as first year enrollments. Rather, a simultaneous equation model is developed which explicitly formulates the interrelated nature of the several demand functions representing progression through higher education. Within this framework, the findings from several statistical and methodological approaches to the demand for education can be analyzed, with a view to reaching a consensus as to the effects of tuition and financial aid at each stage of the choice process.
Prognostic significance of marked leukocytosis in hospitalized patients

Study objective:To identify the prognostic significance of marked neutrophilic leukocytosis (MNL), defined as white blood cell (WBC) count of ≥25,000/µL and ≥80% mature neutrophils by differential count, in hospitalized patients.
Formation and chemical pumping of OH molecules.

It has been suggested that maser amplification may be the cause of intense OH lines observed in some small sources. An efficient two body pre-association of hydrogen and oxygen may lead to the formation of OH and the population inversion needed for maser amplification.
Privacy-preserving DRM

This paper describes and contrasts two families of schemes that enable a user to purchase digital content without revealing to anyone what item he has purchased. One of the basic schemes is based on anonymous cash, and the other on blind decryption. In addition to the basic schemes, we present and compare enhancements to the schemes for supporting additional features such as variable costs, enforcement of access restrictions (such as "over age 21"), and the ability of a user to monitor and prevent covert privacy-leaking between a content-provider-provided box and the content provider. As we will show, the different variants have different properties in terms of amount of privacy leaking, efficiency, and ability for the content provider to prevent sharing of encryption keys or authorization credentials.