cssi/SciSciGPT-SciSciNet huggingface dataset:
Negative Differential Resistance in Patterned Electroactive Self-Assembled Monolayers

The phenomenon of negative differential resistance (NDR) is potentially very useful in molecular electronics device schemes. Here, it is shown that NDR can be observed in self-assembled monolayers composed of electroactive thiols on gold. Furthermore, these monolayers can be patterned using a scanning probe lithography technique described earlier to form a basis for potential molecular electronic device construction.
A nobel prize in microwave engineering

As this issue goes to print, the announcements of the various Nobel Prizes have been prominently featured in the news, and have highlighted the scientific advancements in their respective fields. Such public attention, brought to a scientific work by the award of a Nobel Prize for it, can hardly be matched by anything else, even if over the years the works recognized by these awards have ranged from very significant to obscure, and do not always seem to qualify as a "service to the mankind" that Alfred Nobel envisioned in his will. Service alone is not enough - the microwave oven probably serves mankind close to a billion times a day, but lacks the intrigue of fundamental particle physics. Apparently, one way to bring the accomplishments of microwave engineers to the attention of general public would be to institute a "Nobel Prize in Microwave Theory and Techniques." It is argued that the IEEE Microwave Theory and Techniques Society Awards are as close as one can come to a Nobel Prize in microwave engineering. The Society invites nominations for a number of awards described on its Web site, and the nominations for the year 2003 are presently open.
Oxidative stress affects cytoskeletal structure and cell-matrix interactions in cells from an ocular tissue: the trabecular meshwork.

The trabecular meshwork (TM) is a specialized eye tissue that regulates the aqueous humor outflow and controls intraocular pressure. Cells in this tissue are essential for maintenance of the outflow system. Disturbance of the TM cell status by insults such as oxidative stress may lead to elevation of the intraocular pressure and development of glaucoma. In the present study, we investigated the effect of oxidative stress on the adhesion of human TM cells to extracellular matrix (ECM) proteins. Treatment with 1 mM of H2O2 for 10 or 30 min did not affect cell viability, whereas the adhesion of TM cells to fibronectin, laminin, and collagen types I and IV was significantly reduced. Phalloidin and immunostaining also revealed reorganization of actin and vimentin structures. The level of integrins α5β1, αvβ3, and β1 was not altered, although the distribution of paxillin and focal adhesion kinase in focal contacts was reduced. Concomitantly, the level of transcription factor NF-κB was enhanced by the H2O2 treatment. Nuclear extracts of the treated cells also contained a heightened NF-κB binding activity. These changes persisted for up to 6 h after the H2O2 treatment but were partially recovered by 24 h. We concluded that under sublethal oxidative stress conditions, the TM cell adhesion to the ECM was impaired. The short-term loss of cell-matrix adhesiveness may be related to the rearrangement of cytoskeletal structures. Extensive and repeated oxidative stress in vivo may result in reduced TM cell adhesion, leading to cell loss, compromised TM integrity, and pathologic consequences. J. Cell. Physiol. 180:182–189, 1999. © 1999 Wiley-Liss, Inc.
Dutch immigrant demography 1820-1880

The author analyzes the demographic and social composition of Dutch immigrant households at the time of their arrival in the United States. The data are derived from ship passenger lists for selected U.S. ports over the period 1820-1880. Age-sex ratios and family status of the immigrants are considered and an attempt is made "to determine if migration patterns shifted in response to basic socioeconomic structural changes or if short-term cultural and economic crises in the Netherlands were more influential." (EXCERPT)
Integrated role of two apoliprotein E polymorphisms on apolipoprotein B levels and coronary artery disease in a biethnic population.

Abstract Background: Apolipoprotein E (ApoE) plays a major role in lipoprotein metabolism and genetic variability of ApoE confers susceptibility to coronary artery disease (CAD). Beyond variability in the coding region, promoter polymorphisms in the ApoE gene impact on ApoE transcription. Methods: We determined the ApoE − 491 A/T promoter polymorphism, ApoE isoforms, lipid and lipoprotein levels, and CAD risk factors in 313 Caucasians and 215 African Americans. Results: Caucasians had a lower ApoE T allele frequency compared to African Americans (18.1% vs. 32.3%, P < 0.05). Among T/* carriers, ApoB levels were significantly lower in Caucasians, but significantly higher among African Americans, in both cases compared to A/A homozygotes (P = 0.017, and P = 0.012). For a given −491A/T genotype, levels of atherogenic lipoproteins differed across ApoE2/E3/E4 isoforms among African Americans, but not Caucasians, as T/* carriers with ApoE4 had significantly higher ApoB levels compared to T/* carriers with ApoE2 ...
Mitochondrial Phototoxicity Sensitized by Doxycycline in Cultured Human Carcinoma Cells

Cultured MGH-U1 (human urinary bladder carcinoma) cells were treated with doxycycline (DOTC) and long-wave UV radiation (UVA). At UVA dosed of 1J/cm2 and above, the cells showed mitochondrial damage, reflected by altered localization of the fluorescent probe rhodamine-123, and striking vacuolization for several hours after mitochondrial damage was evident. These changes were potentiated by irradiation in the presence of deuterium oxide, and diminished by irradiation in the presence of sodium azide. Addition of catalase, superoxide dismutase, or mannitol did not alter the damage threshold. These data indicate that the mitochondrion is an earlier target of DOTC photosensitization than the cell membrane. The critical photochemistry appears to involve singlet oxygen.
Metabolic engineering of Saccharomyces cerevisiae to improve 1-hexadecanol production

Fatty alcohols are important components of a vast array of surfactants, lubricants, detergents, pharmaceuticals and cosmetics. We have engineered Saccharomyces cerevisiae to produce 1-hexadecanol by expressing a fatty acyl-CoA reductase (FAR) from barn owl (Tyto alba). In order to improve fatty alcohol production, we have manipulated both the structural genes and the regulatory genes in yeast lipid metabolism. The acetyl-CoA carboxylase gene (ACC1) was over-expressed, which improved 1-hexadecanol production by 56% (from 45mg/L to 71mg/L). Knocking out the negative regulator of the INO1 gene in phospholipid metabolism, RPD3, further enhanced 1-hexadecanol production by 98% (from 71mg/L to 140mg/L). The cytosolic acetyl-CoA supply was next engineered by expressing a heterologous ATP-dependent citrate lyase, which increased the production of 1-hexadecanol by an additional 136% (from 140mg/L to 330mg/L). Through fed-batch fermentation using resting cells, over 1.1g/L 1-hexadecanol can be produced in glucose minimal medium, which represents the highest titer reported in yeast to date.
Speckle in photoacoustic tomography

Photoacoustic tomography is emerging as a promising imaging modality for various biomedical applications. Unlike traditional ultrasound imaging that is plagued by strong speckle artifacts, no obvious speckle has so far been observed in photoacoustic images. We systematically studied the reason for this lack of speckle in photoacoustic tomography based on speckle contrast. Theoretical explanations were validated by simulation. The results here can serve as a basis for developing specific applications, such as tissue characterization, using photoacoustic methods.
Glimpses of a one-speed mind: focus-switching and search for verbal and visual, and easy and difficult items in working memory.

Abstract We investigated focus-switching and search rates in an N-Back task for stimuli presumably encoded either in a phonological/semantic or an abstract–visual format. Experiment 1 used Chinese characters and tested Chinese speakers and non-Chinese speakers; character frequency and visual complexity were also manipulated. Experiment 2 presented Chinese characters and English words to non-Chinese English speakers. Effects of focus-switching on accuracy were larger for abstract–visual stimuli and for more difficult stimuli; effects on RT were larger for abstract–visual stimuli, but there was no effect of difficulty, with the exception of the most difficult stimulus set in Experiment 1. Search slopes outside the focus of attention did not covary with either type of code or item difficulty. The decline in accuracy over set-size was stronger for the items coded in abstract–visual format. This suggests that item availability is sensitive to robustness of the memory representations, but item accessibility is not. The data fit well with a model of STM in which a fixed number of ‘slots’ are searched at a constant rate, regardless of the slot’s contents.
Two-time-scale feedback design of a class of nonlinear systems

For a class of nonlinear singularly perturbed systems, feedback stabilizing and near-optimal controls are designed using two separate lower order subsystems. The two-time-scale properties greatly simplify the stability analysis and the nonlinear controller design. Two electric machine examples (a dc motor and a synchronous generator) illustrate the proposed design procedure.
Is there an Empowerment Life Cycle?: Long-Term Black Empowerment and its Influence on Voter Participation

The authors explore the relationship between long-term black empowerment and racial turnout rates in Atlanta (Georgia), Cleveland (Ohio), and Los Angeles (California). Symbolic politics, intergroup...
Analysis of Fire-related Vegetation Patterns in the Huachuca Mountains, Arizona, USA, and Sierra los Ajos, Sonora, Mexico

There is general interest among fire ecologists to integrate observed fire regimes into long term fire management. The United States-Mexico borderlands provide unique research opportunities to study effects of contrasting forest management activities on forest structure and pattern. To increase understanding of the range of forest stand conditions in borderland ecosystems, we compared tree crown patterns from two forests near the US-Mexico border that are managed under contrasting fire policies and have contrasting fire histories. Locations of individual tree crowns in geographically and ecologically matched forest patches were detected and plotted from Digital Orthophoto Quarter Quadrangles (DOQ) using a semi-automated crown detection procedure. Spatial patterns of tree crowns were analyzed with point pattern methods. Results describe disparate spatial patterns and levels of crown density in fire-managed forests of the US and unmanaged forests of northern Mexico.
Inductor-Based Tuning in $LC$ -Quadrature Oscillators: A Comparative Study

This brief analyzes three different mechanisms for injecting a tuning current into the tank of inductively tuned LC-quadrature oscillators. It is shown that, by controlling how the tuning current is injected into the tank, either by magnetic coupling, direct coupling, or the newly proposed partial coupling, a tradeoff exists between tuning range, phase noise, and power consumption. This leads to a very flexible design methodology where the coupling mechanism can be selected based on system-level requirements, which may change from one design to the next.
Ionic requirements of impaled bull spermatozoa driven by external ADP and ATP.

Abstract The flagellar motion of impaled bull spermatozoa can be maintained by external ADP or ATP. The post-impalement flagellar frequency depends sharply on the external Mg 2+ concentration. 0.3 mM Mg 2+ is required for half-optimal activity with ADP, 0.05 mM Mg 2+ with ATP as external power source. Mn 2+ can substitute partially for Mg 2+ as ionic co-factor. Ca 2+ cannot substitute for Mg 2+ , and at concentrations above 0.5 mM it inhibits motility slightly. Zn 2+ acts only as inhibitor of post-impalement flagellar activity, reducing it to zero at concentrations above 1 mM.
Spatiotopic organization in human superior colliculus observed with fMRI.

Spatiotopy is a fundamental organizing principle of the visual brain. Using functional magnetic resonance imaging, we have demonstrated reliable data, consistent with spatiotopic organization in the human superior colliculi. Five subjects underwent cardiac-triggered echo-planar image acquisition, during which they viewed alternating left and right visual hemifield stimulation. Intensity variations from the variable TR were removed, and the data were evaluated for correlation with the lateralized stimulus. The data indicate a strongly preferential response of the left superior colliculus to the right side of visual space, and vice versa. This is consistent with previous findings in animal systems and confirms the existence of spatiotopy in the human superior colliculus.
Significance of silent myocardial ischemia during exercise testing in women: report from the Coronary Artery Surgery Study.

Abstract To evaluate the significance of silent myocardial ischemia during exercise testing in women compared to men, we analyzed the data on 1087 women and 3834 men who underwent exercise testing and coronary angiography from the Coronary Artery Surgery Study (CASS) registry. The patients were divided into three groups on the basis of the results of exercise testing: group 1 silent ischemia (253 women, 853 men); group 2, symptomatic ischemia (156 women, 1250 men); and group 3, no ischemia (678 women, 1731 men). The survival rate at 12 years for women was 80% for group 1, 75% for group 2, and 86% for group 3 ( p = 0.0022); the survival rate for men was 69% for group 1, 69% for group 2, and 76% for group 3 ( p p = 0.0014) but not for women (45% vs 50%, respectively, p = 0.98). These data suggest that silent ischemia in women and men adversely affects survival rate and that men may gain more benefit from coronary artery bypass graft surgery than women when three-vessel CAD is present.
Phonon Lasers in Cavity Optomechanics

The possibility of a phonon laser, the analog of an optical laser except for vibronic motion, has been considered since the earliest days of the optical laser. There are numerous proposals for these devices, and also evidence of stimulated phonon emission in paramagnetic systems at cryogenic temperatures (see [1,2] and references therein). However, phonon laser action in which stimulated emission of phonons overcomes mechanical loss, leading to coherent mechanical motion has only recently been demonstrated [1,2]. One of these systems operates in analogy to a two-level photon laser. Electronic transitions are replaced by phonon-mediated transitions between optical modes of a compound, whispering-gallery resonator (see figure 1). By optical pumping of the upper level, phonon gain is produced leading to coherent mechanical oscillation above a clear threshold (see figure 2). The interaction is provided by radiation pressure within the microcavity system, which provides a “dipole-like” coupling of the optical supermodes to the mechanical breathing modes of either resonator. The physics of this device is reviewed along with data showing threshold and line narrowing. Finally, we illustrate how these devices can be fully integrated as planar sources of vibrational coherence using the new technology of “optomechanical crystals” [3]. The possibility of a phonon laser, the analog of an optical laser except for vibronic motion, has been considered since the earliest days of the optical laser. There are numerous proposals for these devices, and also evidence of stimulated phonon emission in paramagnetic systems at cryogenic temperatures (see [1,2] and references therein). However, phonon laser action in which stimulated emission of phonons overcomes mechanical loss, leading to coherent mechanical motion has only recently been demonstrated [1,2]. One of these systems operates in analogy to a two-level photon laser. Electronic transitions are replaced by phonon-mediated transitions between optical modes of a compound, whispering-gallery resonator (see figure 1). By optical pumping of the upper level, phonon gain is produced leading to coherent mechanical oscillation above a clear threshold (see figure 2). The interaction is provided by radiation pressure within the microcavity system, which provides a “dipole-like” coupling of the optical supermodes to the mechanical breathing modes of either resonator. The physics of this device is reviewed along with data showing threshold and line narrowing. Finally, we illustrate how these devices can be fully integrated as planar sources of vibrational coherence using the new technology of “optomechanical crystals” [3].
Precise efficiency calibration of an HPGe detector up to 3.5 MeV, with measurements and Monte Carlo calculations

Previously we used relative and absolute efficiency measurements combined with Monte Carlo calculations to define the efficiency of an HPGe gamma-ray detector with 0.2% accuracy from 50 to 1400 keV. This work has been extended to 4.8 MeV with measurements of relative efficiencies from 24Na, 56Co, and 66Ga sources. The combined results of experiment and calculation yield an efficiency curve up to 3.5 MeV with 0.4% accuracy. Single- and double-escape peak contributions also agree with calculation if positron annihilation-in-flight is incorporated.
Determination of Hydroxy Compounds by 4-Dimethylaminopyridine-Catalyzed Acetylation

Abstract: 4-Dimethylamlnopyridine is an effective catalyst of analytical acylations by acetic anhydride, having a specific catalytic activity about 10 4 times greater than that of pyridine. The conventional titrimetric determination of hydroxy groups is carried out with 4-dimethylaminopyridine as the catalyst and pyridine as the solvent. Typical reaction times for primary and secondary alcohols are 5–10 min. at 54-70°.
Access to Remote Electronic Resources at the University of Arizona

SUMMARY As libraries shift towards increasingly virtual collections, provision of both intellectual and physical or actual network access to an electronic resource is paramount to the ability of libraries to successfully serve customers. A number of issues make access to these resources difficult, including lack of persistence in the naming of resources and difficulties in providing remote access to resources. While it is impossible to absolutely control access within this electronic environment, it is possible to choose solutions that make managing access easier. The University of Arizona Libraries have chosen to use Persistent Uniform Resource Locators (PURLs) to address transience of links, and EZProxy, a pass-through proxy, to provide remote access as a solution to this problem.
Proton NMR study of the thermodynamics and kinetics of the acid ⇌ base transitions in reconstituted metmyoglobins

Abstract Optical and proton NMR pH titrations of sperm whale metmyoglobin (metMb) in its native form and reconstituted with chemically modified hemes reveal that the p K a for the acid ⇌ base transition decreases as the heme 2,4-substituents are made more electron withdrawing. The proton NMR spectra yields resonances which are averaged over the acidic and basic forms of the protein, but still exhibit significant exchange line broadening. Analysis of this exchange contribution to the linewidth is consistent with the simple kinetic scheme metMb ∗ H 2 O + OH − ⇌ k 2 k 1 with k 2 = 1.3 ± 0.5 · 10 10 M −1 · s −1 and k 1 = 1.6 ± 0.6 · 10 5 s −1 for the native protein. The effect of electron-withdrawing substituents on the heme increase k 2 and decrease k 1 .
Charge carrier transport in poly(2,5-dialkoxy-p-phenylene ethynylene)s

Abstract The charge carrier transport in poly[2,5-dioctyloxy-1,4-diethynyl-phenylene- alt -2,5,-bis(2′-ethylhexyloxy)-1,4-phenylene], a poly( p -phenylene ethynylene) (PPE) derivative, was investigated by time-of-flight (TOF) measurements. The charge transport characteristics in this material are ambipolar, and the transport is dispersive, with high electron (2.2×10 −3 cm 2 V −1 s −1 ) and hole (1.8×10 −3 cm 2 V −1 s −1 ) mobilities at room temperature and at low field (3.1×10 4 V cm −1 ). The mobility strongly depends on the field strength, and is observed to decrease with increasing bias. The positional and energetic disorder parameters were calculated from the temperature and field dependencies of the charge mobility using a Gaussian disorder transport formalism. The positional disorder was found to be larger than the energetic disorder over the entire experimental temperature range, leading to the observed negative field dependence of the carrier mobility.
The absorption of sustained‐release methylphenidate formulations compared to an immediate‐release formulation

A crossover study in 18 subjects evaluated the plasma concentration-time profile of two different 20 mg sustained-release (SR) methylphenidate (MPH) tablets administered before breakfast, compared to a 10 mg immediate-release (IR) tablet administered before breakfast and again 5 h later, before lunch. Plasma MPH concentrations were determined using a sensitive and precise gas chromatography-mass spectrometry method, incorporating a deuterated internal standard. The mean peak MPH concentration was 6.4 ng ml-1 for the IR product versus 4.6 ng ml-1 and 4.8 ng ml-1 for the two SR formulations. Peak concentrations occurred at 3.3 h after dosing with the SR products, compared to 1.5 h after the first dose of the IR product. The extent of absorption for the three products, as determined from areas under the plasma concentration-time curves, were within 5 per cent of each other. There was no significant difference in rate or extent of absorption between the two SR formulations.
Scanning fluorescence correlation spectroscopy: a tool for probing microsecond dynamics of surface-bound fluorescent species.

In this report, a combined imaging and fluorescence correlation spectroscopy (FCS) method is described and its ability to characterize microsecond fluctuations in the fluorescence emission of a sam...
The influence of lower extremity joint torque on gait characteristics in elderly men

Abstract Burnfield JM, Josephson KR, Powers CM, Rubenstein LZ. The influence of lower extremity joint torque on gait characteristics in elderly men. Arch Phys Med Rehabil 2000;81:1153-7. Objective: To examine the relation between certain lower extremity isokinetic muscle torque capabilities and selected stride characteristics for a group of elderly, sedentary men. Study Design: Descriptive analysis of convenience sample. Setting: Veterans Administration (VA) ambulatory care center. Subjects: Eighty-one elderly men, capable of independent ambulation, were recruited from outpatient clinics and the local community (mean age, 74.7yr). Main Outcome Measures: Maximal isokinetic torque in the sagittal plane of hip, knee, and ankle muscles; stride characteristics of speed, stride length, and cadence recorded during walking at a self-selected velocity. Results: Stepwise regression analysis revealed that hip extension torque was the only significant independent predictor for free walking speed, stride length, and cadence, and accounted for 37% ( r =.611), 35% ( r =.590), and 12% ( r =.341) of the total variance, respectively. Other joint torques correlated with gait parameters but did not add significantly to the multivariate model. Conclusions: Hip extension torque was the only significant independent predictor for free walking velocity, stride length, and cadence in this group. These results support the idea that strengthening the hip extensors may improve stride characteristics in elderly individuals. © 2000 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
Isolated ventricular myocytes from failing and non-failing human heart; the relation of age and clinical status of patients to isoproterenol response.

Single cardiac myocytes were isolated from the ventricles of failing and non-failing human hearts. The contraction amplitude, time-to-peak shortening and time to 50% and 90% relaxation were measured in cells stimulated at 0.2 Hz at 32°C. The effects of increasing extracellular calcium and isoproterenol were investigated using cumulative concentration/response curves. Maximum contraction amplitude in high calcium or velocities of contraction or relaxation were not impaired in cells from failling hearts. Beta-adrenoceptor function in a single cell was assessed by the maximum contraction amplitude in the presence of isoproterenol relative to that with high calcium in the same cell (isoproterenol/calcium ratio). A decrease in the isoproterenol/calcium ratio correlated positively with an increase in the isoproterenol EC50 (concentration for half-maximal effect) for a cell (P<0.02, n = 39). The isoproterenol/calcium ratio in left ventricular myocytes decreased with increasing severity of disease, correlating with failure as defined by New York Heart Association class (P<0.001, n = 26 patients), left ventricular ejection fraction (P<0.001, n = 24), left ventricular end diastolic pressure (P<0.05, n = 21) and amount of diuretics prescribed (P<0.001, n = 26). In right ventricular myocytes, only increasing NYHA class correlated with decreasing isoproterenol/calcium ratios. There was a correlation of the isoproterenol/calcium ratio between right and left ventricular cells from patients with ischemic heart disease (P<0.05, n = 11). Beta-adrenoceptor subsensitivity occurred in mitral valve disease, ischemic heart disease, congenital abnormalities and congestive cardiomyopathy, but not in the right ventricle of patients with myocarditis. The isoproterenol/calcium ratio correlated negatively with the age of the patient (P<0.001, n = 26, left ventricle). Multiple regression indicated that the maximum contraction amplitudes in either high isoproterenol or high calcium declined significantly with age only, but that both age and severity of disease contributed to the decrease in isoproterenol/calcium ratio. Time-to-peak tension in isoproterenol, as well as relaxation times in high calcium also decreased with the age of the patient. Analysis of variance showed that between-patient variation was significantly greater than between-cell for most of the parameters measured. Beta-adrenoceptor desensitisation may be detected in individual myocytes from failing hearts, and this relates more to the severity of disease and the age of the patient rather than the etiology of heart failure. A decline in absolute contractility of muscle cells with age was detected.
Thomas Jefferson's computer

Abstract That Thomas Jefferson was a prolific writer is generally recognized. Less well known are his contributions to the history of writing technology. Jefferson invented or improved devices for composing, copying, and encrypting. When the devices Jefferson developed are considered together, they demonstrate a virtual “computer.” As a writer, Jefferson used his improvised “computer” to draft the American Declaration of Independence and, as an officeholder, to create a public record of government. This essay links Jefferson's development of writing technology to his democratic political philosophy. The link should interest writing teachers. Those concerned about oppressive social effects of computers can gain perspective from Jefferson's principled practice. From the Jeffersonian principle of selfgoverning democracy, it follows that user communities, not devices, determine what technology can do. Jefferson's mechanization of copying exemplifies the use of information technology to support democratic governance. Applied to a question troubling the teaching profession, whether information networks might help or hinder democracy in education, Jeffersonian optimism effectively counters Foucauldian pessimism.
PAR-1 antagonist SCH79797 ameliorates apoptosis following surgical brain injury through inhibition of ASK1-JNK in rats

Neurosurgical procedures inevitably produce intraoperative hemorrhage. The subsequent entry of blood into the brain parenchyma results in the release of large amounts of thrombin, a known contributor to perihematomal edema formation and apoptosis after brain injury. The present study seeks to test 1) the effect of surgically induced brain injury (SBI) on thrombin activity, expression of thrombin's receptor PAR-1, and PAR-1 mediated apoptosis; 2) the effect of thrombin inhibition by argatroban and PAR-1 inhibition by SCH79797 on the development of secondary brain injury in the SBI model on rats. A total of 88 Sprague-Dawley male rats were randomly divided into sham, vehicle-, argatroban-, or SCH79797-treated groups. SBI involved partial resection of the right frontal lobe under inhalation isoflurane anesthesia. Sham-operated animals received only craniotomy. Thrombin activity, brain water content, and neurological deficits were measured at 24 h following SBI. Involvement of the Ask1/JNK pathway in PAR-1-induced post-SBI apoptosis was characterized by using Ask1 or JNK inhibitors. We observed that SBI increased thrombin activity, yet failed to demonstrate any effect on PAR-1 expression. Argatroban and SCH79797 reduced SBI-induced brain edema and neurological deficits in a dose-dependent manner. SBI-induced apoptosis seemed mediated by the PAR-1/Ask1/JNK pathways. Administration of SCH79797 ameliorated the apoptosis following SBI. Our findings indicate that PAR-1 antagonist protects against secondary brain injury after SBI by decreasing both brain edema and apoptosis by inactivating PAR-1/Ask1/JNK pathway. The anti-apoptotic effect of PAR-1 antagonists may provide a promising path for therapy following SBI.
Rank extraction in tin-oxide sensor arrays

Abstract It is shown that data pre-processing by rank-order filtering can significantly improve the odor discrimination capability of an array of chemical sensors, while simultaneously reducing the amount of data to be processed. This work is a first example in feature extraction from tin-oxide sensors that both reduces the size of the data set and simultaneously improves the discrimination performance of the array. This work is aimed toward the design of remote sensor modules where bandwidth reduction and improved accuracy are both essential to system performance. The effectiveness of extracting rank from a 30-element array of tin-oxide sensors is presented. Results are extrapolated to other arrays of chemical sensors whose specificities and response characteristics overlap. Methods for processing data and extracting rank-related features from arrays of tin-oxide sensors are comparatively analyzed. Processing parameters studied include those related to temporal filtering and window-averaging, pre-scaling (to remove baseline), sample acquisition time, and the number of ranks used in rank-order filtering of the data during the transient and steady state response. Cluster analysis, including principal component analysis (PCA) and a novel method described herein, is used to determine which of these processing techniques are most effective. Artificial neural networks, specifically multi-layer perceptrons and radial basis function networks, are used to further investigate the ability to discriminate odors on the basis of the extracted features. The analysis is performed for an array of 30 tin-oxide sensors applied to detecting a sampling of breath alcohol mixtures (beer, wine, vodka) and common interferents (acetone, formaldehyde, isopropyl). Ammonia is included as a contrast substance. For the set of seven odorants studied, it is found that using rank-order filtering with 10 or more ranks improves odor recognition rate by a multi-layer perceptron neural network from 92% to 95%. If one odor (vodka) is removed from the study set, the recognition rate for the remaining odors improves from 95% (with no rank-order filtering) to 99%. Simultaneously, the dimensions of the data set for each odor are reduced from 30 sensors×18,000 time steps (12 bit samples) to N integer values, where N is the number of ranks used in the rank-order filtering.
The local introduction of strongly interacting species and the loss of geographic variation in species and species interactions

Species introductions into nearby communities may seem innocuous, however, these introductions, like long-distance introductions (e.g. trans- and intercontinental), can cause extinctions and alter the evolutionary trajectories of remaining community members. These 'local introductions' can also more cryptically homogenize formerly distinct popula- tions within a species. We focus on several characteristics and the potential consequences of local introductions. First, local introductions are commonly successful because the species being introduced is compatible with existing abiotic and biotic conditions; many nearby communities differ because of historical factors and the absence of certain species is simply the result of barriers to dispersal. Moreover, the species with which they interact most strongly (e.g. prey) may have, for example, lost defences making the establishment even more likely. The loss or absence of defences is especially likely when the absent species is a strongly interacting species, which we argue often includes mammals in terrestrial communities. Second, the effects of the introduction may be difficult to detect because the community is likely to converge onto nearby communities that naturally have the introduced species (hence the perceived innocuousness). This homogenization of formerly distinct populations eliminates the geographic diversity of species interactions and the geographic potential for speciation, and reduces regional species diversity. We illustrate these ideas by focusing on the introduction of tree squirrels into formerly squirrel-less forest patches. Such introductions have eliminated incipient species of crossbills ( Loxia spp.) co-evolving in arms races with conifers and will likely have considerable impacts on community structure and ecosystem processes.
Integrals of multinomial systems of ordinary differential equations

On donne une solution partielle du probleme de la determination de toutes les integrales algebriques d'un systeme d'equations differentielles y i =f i (y 1 ,...,y n ), (i=1,...,n), ou les f i sont des fonctions rationnelles de y 1 ,...,y n a coefficients constants
Fluorescent probes for monitoring temperature in organic solvents

We report two fluorophores, N-(1-pyrenylmethyl)-1-pyrenebutanamide and N-(1-pyrenylmethyl)-1-pyreneacetamide, that exhibit temperature-dependent emission spectra over the temperature range of 20−100 °C. The fluorophores are readily synthesized via a one-pot process and can be used in dilute form (<1 μM) for measuring the temperature of various organic solvents nonintrusively. The fluorophores allow measurement of temperatures within a precision of ±1 °C and provide an internal reference signal that allows factors such as fluorophore concentration, optical path, and excitation light intensity to be ignored.
The Semmes Weinstein monofilament examination is a significant predictor of the risk of foot ulceration and amputation in patients with diabetes mellitus.

Objective Diabetic peripheral neuropathy is a major complication of diabetes mellitus (DM) and is the leading cause of foot ulceration and lower extremity amputations (LEAs). The purpose of this systematic review is to evaluate current evidence regarding the prognostic value of the Semmes Weinstein monofilament examination (SWME) in predicting foot ulceration and LEA in patients with DM. Methods The MEDLINE/PubMed database was searched through November 2009 for articles pertaining to diabetic foot and SWME with no language or publication date restrictions. Prognostic studies with original data assessing the predictive value of SWME for foot ulceration or LEA in patients with DM were included in the selection. Data were systematically extracted and analyzed by two independent investigators. Absolute risks and relative risks were determined for each study. Results Of the 863 studies identified, nine articles were relevant, involving 11,007 patients with DM. Six studies were identified that assessed the prognostic value of SWME regarding diabetic foot ulceration. The relative risk for patients with a positive SWME result versus those with a negative result ranged from 2.5 (95% confidence interval [CI], 2.0 to 3.2) to 7.9 (95% CI, 4.4 to 14.3) in the identified studies with follow up between 1 and 4 years. Three of the studies assessed the risk of LEA with a positive SWME result. The relative risk for LEA ranged from 1.7 (95% CI, 1.1 to 2.6) to 15.1 (95% CI, 4.3 to 52.6) with follow-up between 1.5 and 3.3 years. Conclusions All nine studies found SWME to be a significant and independent predictor of future foot ulceration or likely of future LEA as well in patients with DM. Therefore, SWME is an important evidence-based tool for predicting the prognosis of patients with diabetic foot, thus enabling improved patient selection for early intervention and management. More research should be conducted to elucidate the relationship between SWME and LEA.
Seminal Composition and Sexual Activity after Castration and Testosterone Replacement in Rabbits

SummaryLosses of libido and seminal volume, fructose and gel were quantified in eight rabbits ejaculated every second day for 26 days after castration. Androgen requirement for restoration of normal libido and seminal characteristics was established in the same rabbits by injections of testosterone propionate (TP) at levels of from 0.5 to 12.0 mg every second day. Gel mass disappeared from ejacula immediately after castration and seminal fructose declined from 760 μg before castration to 192 μg/ejaculum within 48 hr. But seminal volume and libido declined only gradually and linearly for 3 weeks after castration. Even after 26 days, nearly all rabbits mounted and thrust vigorously although unable to ejaculate. Although libido of castrate rabbits was increased significantly by 0.5 or 1.0 mg of TP, seminal characteristics were not. Control levels of both were reestablished at 8.0 mg of TP.
Nonlinear dynamics of solids by the finite element method

Abstract A method for analyzing the nonlinear dynamic response of deformable solids, subjected to time and space dependent thermal and mechanical loads, is developed. The nonlinearities considered in this analysis are due to the nonlinear character of the strain displacement relations and the equations of motion and to the nonlinear constitutive relations which describe the physical behavior of the material. In this investigation, elastic-plastic relations of the incremental (Prandtl-Reuss) type were chosen for material description. A displacement-type finite element method is applied to reduce the governing partial differential equations to a set of simultaneous nonlinear ordinary differential equations of motion of a lumped mass system connected by three-dimensional elements. These equations are solved by applying a step-by-step numerical technique in conjunction with the constitutive relations. The analysis is specifically applied to plane strain problems. Two plane wave propagation problems and two large deformation problems of shells and beams under blast loading were investigated. Comparison of analytical or experimental results with numerical calculations indicates good agreement.
Melatonin is an efficient antioxidant.

Abstract We have compared the peroxyl radical scavenger ability of melatonin with that of vitamin E, ascorbic acid (As.A.), reduced glutathione (GSH) and mannitol. All the antioxidants, except mannitol, prevented the lysis of human erythrocytes exposed to an azo-initiator of peroxyl radicals (2,2′-azo-bis(2-amidinopropane)dihydrochloride) at 37°C. The percentage of this inhibition of erythrocyte lysis varied with the concentration of antioxidants, but the efficiency was melatonin > vitamin E > As.A. > GSH. Based on the assumption that each molecule of vitamin E scavenges two peroxyl radicals, the scavenging capacity of melatonin was four peroxyl radicals/molecule.
Generation of melt during crushing experiments on freshwater ice

Abstract A stainless-steel platen, with arrays of pressure sensors and thermocouples on the front face, has been used to crush mono-crystalline, bubble-free freshwater ice samples at −10°C and −5°C at various constant speeds. One of the thermocouples was located at the center of the platen's central pressure transducer. Video records of the ice/steel contact zone during crushing were obtained by mounting samples on a thick plexiglas plate which permitted viewing through the specimens to the ice/steel interface. Total load and pressure records exhibited a sawtooth pattern. The relative movement of the ice towards the platen was not uniform but was much slower on the ascending side of each sawtooth, where elastic energy built up in the ice and apparatus, than on the steep descending portion, where the energy was released and the main damage of the ice occurred. This mode of periodic failure was caused by the compliance of the ice and the testing apparatus. Peak pressures were in the pressure melting range for the temperatures investigated. Contact between the platen and the ice consisted of low pressure zones of highly damaged crushed and/or refrozen ice, opaque in appearance, and regions of relatively undamaged ice, transparent in appearance, where ∼88% of the load was borne and the pressure was ⩾ 70 MPa. Specific energy calculations for the ejecta extruded from high pressure zones, based on video and load records, and temperature measurements indicated that the ejecta was partially liquid and that pressure melting and heat generation by viscous flow of liquid plays an important role in ice crushing. The process was responsible for at least ∼64% of the energy dissipated in these tests.
Histochemical study of the acetylcholinesterase activity in the inner ear of the squirrel monkey.

Perfusion-fixation was performed on the squirrel monkey, whose temporal bones were then decalcified in cold EDTA (ethylenediamine tetracetate) solution. Gholinesterase (ChE) activity was demonstrated on frozen sections of these bones. ChE in the efferent fibers of the inner ear was identified as acetylcholinesterase (AChE) by using specific inhibitors. Fine, scattered AChE containing fibers in the cochlear nerve were observed crossing the glial-Schwann sheath junction which were not a part of Rasmussen's bundle. After transection of the cochlear nerve, these fine fibers lost AChE activity, suggesting they were of efferent nature. In the organ of Corti, both the upper tunnel radial and basilar bundles were found to show AChE activity. These two bundles apparently contained efferent fibers.
Analysis of the spatial filtering approach to the decorrelation of coherent sources

The recently proposed spatial filtering, which is developed to effectively decorrelate coherent signals, is analyzed. It has been shown that any set of distinct preliminary estimates of directions of arrival (DOAs) can be used to obtain a full rank source covariance matrix. In addition, a particular signal enhancement approach is developed to minimize the effects of the sensor noise. Statistical analysis of the spatial filtering and its enhanced version are also studied using the Monte Carlo method. >
Hierarchy of regional oxygen delivery during cardiopulmonary bypass

Abstract Background . Relative to the nonbypass state, cardiopulmonary bypass may decrease whole-body oxygen (O 2 ) delivery. We predicted that during cardiopulmonary bypass, a hierarchy of regional blood flow and O 2 delivery could be characterized. Methods . In 8 46.5 ± 1.2-kg pigs, fluorescent microspheres were used to determine blood flow and O 2 delivery to five organ beds before and during 37°C cardiopulmonary bypass at four randomized bypass flows (1.4, 1.7, 2.0, and 2.3 L/min/m 2 ). At completion, 18 tissue samples were obtained from the cerebral cortex (n = 4), renal cortex (n = 2), renal medulla (n = 2), pancreas (n = 3), small bowel (n = 3), and limb muscle (n = 4) for regional blood flow determination. Results . At conventional cardiopulmonary bypass flow (2.3 L/min/m 2 ), whole-body O 2 delivery was reduced by 44 ± 6% relative to the pre-cardiopulmonary bypass state ( p 2 ), brain and kidney maintained their perfusion. Blood flow and O 2 delivery to both regions were reduced when the cardiopulmonary bypass flow was reduced to 1.4 L/min/m 2 . However, perfusion and O 2 delivery to other visceral organs (pancreas, small bowel) and skeletal muscle showed pump flow dependency over the range of flows tested. Conclusions . This study characterizes the organ-specific hierarchy of blood flow and O 2 distribution during cardiopulmonary bypass. These dynamics are relevant to clinical decisions for perfusion management.
Bone morphogenic protein 2 induces Runx2 and osteopontin expression in human aortic valve interstitial cells: Role of Smad1 and extracellular signal-regulated kinase 1/2

Objective Bone morphogenic protein 2 is found in calcified areas of stenotic aortic valves, and prolonged stimulation of aortic valve interstitial cells with bone morphogenic protein 2 results in increased expression of alkaline phosphatase, indicating a mechanistic role for bone morphogenic protein 2 in aortic valve calcification. The purposes of this study were to assess the effect of bone morphogenic protein 2 on the expression of the osteogenic factors Runx2 and osteopontin in human aortic valve interstitial cells and to determine the signaling mechanisms that mediate the expression of these early osteogenic factors. Methods Interstitial cells were isolated from normal and stenotic human aortic valve leaflets, and cellular bone morphogenic protein 2 levels were analyzed by means of immunoblotting. Cultured interstitial cells from normal aortic valves were stimulated with bone morphogenic protein 2 to determine its effect on cellular Runx2 and osteopontin levels. Results Interstitial cells from stenotic aortic valves express greater levels of bone morphogenic protein 2 than cells from normal valves. Stimulation of human aortic valve interstitial cells with bone morphogenic protein 2 induced marked increases in Runx2 and osteopontin levels at 48 hours. The changes in Runx2 and osteopontin levels were preceded by phosphorylation of Smad1 and extracellular signal-regulated kinase 1/2 but not p38 mitogen-activated protein kinase. Silencing Smad1 reduced Runx2 and osteopontin levels, whereas inhibition of extracellular signal-regulated kinase 1/2 reduced osteopontin expression without an influence on Runx2 expression. Conclusions Interstitial cells of stenotic human aortic valves are characterized by increased bone morphogenic protein 2 levels. A short period of exposure of human aortic valve interstitial cells to bone morphogenic protein 2 induces the expression of Runx2 and osteopontin. The extracellular signal-regulated kinase 1/2 pathway modulates bone morphogenic protein 2–induced osteopontin expression, and the Smad1 pathway plays a role in regulating the expression of both Runx2 and osteopontin induced by bone morphogenic protein 2.
The Postural Comfort Zone for Reaching Gestures

We have proposed a method for objective assessment of postural comfort (Kolsch et al., 2003). We defined comfort as the range of postures that is voluntarily assumed despite the availability of other postures. Designing user interfaces within the limits of comfort zones can avert risks associated with unknown alternative use patters of the interface.Here we report on a user study that investigated the comfort zone for free-hand gestures in the horizontal plane at about stomach height. This space is of particular interest to novel technologies such as gesture recognition and virtual reality. The results are in line with previous studies on postural discomfort, but improve on resolution and are not based on subjective, questionnaire-based data acquisition. This study also serves as an example for how to design studies for comfort evaluation.