cssi/SciSciGPT-SciSciNet huggingface dataset:
Entropically driven binding in a self-assembling molecular capsule

THE encapsulation of molecules within larger molecular or supramolecular cages (see ref. 1 for examples) brings about many interesting phenomena, among them the stabilization of reactive intermediates2, new forms of stereoisomerism3, and templating of the cage itself4,5. Here we describe a self-assembling hydrogen-bonded molecular capsule that encapsulates guest molecules in a reversible, apparently entropy-driven process, giving rise to unusual temperature dependence of the formation process. The positive entropy of formation—at first sight unexpected—seems to be the result of the fact that more than one solvent molecule is included in the 'bare' cage, making their replacement by a single large molecule (here adamantane or ferrocene) entropically favourable.
A hub matrix theory and applications to wireless communications

This paper considers communications and network systems whose properties are characterized by the gaps of the leading eigenvalues of AHA for a matrix A. It is shown that a sufficient and necessary condition for a large eigen-gap is that A is a "hub" matrix in the sense that it has dominant columns. Some applications of this hub theory in multiple-input and multiple-output (MIMO) wireless systems are presented.
Multiple ischemic strokes after transcatheter arterial chemoembolization for hepatocellular carcinoma with a radiographic and pathological correlate.

Introduction Transcatheter arterial chemoembolization (TACE) is a widely used form of therapy in advanced hepatocellular carcinoma. We report the first pathological data from an autopsy case of multiple cerebral emboli occurring during TACE. Methods A Medline search for previous cases of cerebral embolism and TACE revealed 11 other cases. Findings Multiple microscopic subacute infarcts were found in the cerebrum, midbrain, and cerebellum of our patient on autopsy, but no embolic material was seen. Embolic material was noted in dilated vessels throughout the fibrotic right diaphragm and in the upper lobe of the right lung. Combining the literature search with our patient, the mortality of cerebral embolism after TACE is 25% (n = 12). Intracardiac shunts were seen in 20% of the cases (n = 10). Hyperdense lesions were seen on head CT in 80% of the patients evaluated (n = 10). Chest imaging revealed infiltrate or consolidation in 60% of the cases (n = 5). Pulmonary emboli were reported in 100% of the cases (n = 8). Conclusions Cerebral embolism after TACE is devastating. Brain pathology supports embolization of ethiodized oil rather than DC beads as the mechanism of cerebral injury. Further pathological studies are needed to better understand the pathophysiology of this condition. Lung pathology confirmed the presence of embolic material in the distal lung, suggestive of a hepatopulmonary shunt undetectable by current modalities. Evaluation for such shunts with emerging modalities such as TCD with emboli detection may be an area of future research.
Brain μ-Calpain Autolysis During Global Cerebral Ischemia

Proteolytic degradation of numerous calpain substrates, including cytoskeletal and regulatory proteins, has been observed during brain ischemia and reperfusion. In addition, calpain inhibitors have been shown to decrease degradation of these proteins and decrease postischemic neuronal death. Although these observations support the inference of a role for mu-calpain in the pathophysiology of ischemic neuronal injury, the evidence is indirect. A direct indicator of mu-calpain proteolytic activity is autolysis of its 80-kDa catalytic subunit, and therefore we examined the mu-calpain catalytic subunit for evidence of autolysis during cerebral ischemia. Rabbit brain homogenates obtained after 0, 5, 10, and 20 min of cardiac arrest were electrophoresed and immunoblotted with a monoclonal antibody specific to the mu-calpain catalytic subunit. In nonischemic brain homogenates the antibody identified an 80-kDa band, which migrated identically with purified mu-calpain, and faint 78- and 76-kDa bands, which represent autolyzed forms of the 80-kDa subunit. The average density of the 80-kDa band decreased by 25 +/- 4 (p = 0.008) and 28 +/- 9% (p = 0.004) after 10 and 20 min of cardiac arrest, respectively, whereas the average density of the 78-kDa band increased by 111 +/- 50% (p = 0.02) after 20 min of cardiac arrest. No significant change in the density of the 76-kDa band was detected. These results provide direct evidence for autolysis of brain mu-calpain during cerebral ischemia. Further work is needed to characterize the extent, duration, and localization of mu-calpain activity during brain ischemia and reperfusion as well as its role in the causal pathway of postischemic neuronal injury.
A 5 GHz CMOS Variable Gain Low Noise Amplifier for wireless LAN Applications

This paper describes a 5 GHz fully differential variable gain low noise amplifier (VGLNA) in a 0.18-mum CMOS process. The LNA provides a 50-Omega input impedance and utilizes a tuned load to provide high selectivity. The VGLNA achieves a maximum small signal gain of 12.34 dB within 1-dB compression point (iCP1db) of -12.0 dBm and a minimum gain of 6 dB. In the high gain mode(HGM) and low gain mode (LGM), the noise figures (NFs) are 3.89 dB and 4.25 dB, respectively with good input return loss. The LNA's IIP3 in the HGM is - 1.24 dBm. The LNA consumes only 5.79 mA of current from a 1.5-V power supply.
Map Quality for Site-Specific Fertility Management

Maps are fundamental to SSFM because they repThe quality of soil fertility maps affects the efficacy of site-specific resent either the spatial state of a condition of soil fertility management (SSFM). The purpose of this study was to interest, the prescription of inputs needed to manage a evaluate how different soil sampling approaches and grid interpolation particular condition site-specifically, or a record of inschemes affect map quality. A field in south central Michigan was puts or outputs (Pierce and Nowak, 1999). In his review soil sampled using several strategies including grid-point (30- and 100- of variable rate technology (VRT), Sawyer (1994) conm regular grids), grid cell (100-m cells), and a simulated soil map cluded that the success of VRT depends to a large extent unit sampling. Soil fertility [pH, P, K, Ca, Mg, and cation-exchange on the quality of fertility management maps. Although capacity (CEC)] data were predicted using ordinary kriging, inverse methods exist for measuring map quality, in general, distance weighted (IDW), and nearest neighbor (NN) interpolations maps used in SSFM are rarely examined for quality for the various data sets. Each resulting map was validated against (Sawyer, 1994; Pierce and Nowak, 1999). Thus, poor an independent data (n 62) set to evaluate map quality. While soil properties were spatially structured, kriging predictions were marginal map quality may explain why results of some SSFM (prediction efficiencies 48%) at high sample densities and poor at agronomic and economic studies have produced mixed lower densities (i.e., 61- and 100-m grids; prediction efficiencies or negative results (Wibawa et al., 1993; Wollenhaupt 21%). The average optimal distance exponent at each scale of mea- and Bucholz, 1993; Snyder et al., 1996; Lowenberg-Desurement was 1.5. The performance of kriging relative to IDW meth- boer and Swinton, 1997). Map quality consists of two ods (with a distance exponent of 1.5) improved with increasing sam- components, map precision and map accuracy. The forpling intensity (i.e., IDW was superior to kriging for 100% of cases mer is a measure of residual variability in map predicwith the 100-m grid, 79% of the cases with the 61.5-m grid scale, and tion, whereas the latter measures the closeness to the 67% of the cases with the 30-m grid). Practically, there was little true conditions. Map quality is quantified as the mean difference between these interpolation methods. Grid sampling with square error (MSE) of residuals (predicted measured) a 100-m grid, grid cell sampling, and simulated soil map unit sampling obtained with an independent validation data set. yielded similar prediction efficiencies to those for the field average approach, all of which were generally poor.
Usefulness of ensemble forecasts from NCEP Climate Forecast System in sub‐seasonal to intra‐annual forecasting

Typically, sub-seasonal to intra-annual climate forecasts are based on ensemble mean (EM) predictions. The EM prediction provides only a part of the information available from the ensemble forecast. Here we test the null hypothesis that the observations are randomly distributed about the EM predictions using a new metric that quantifies the distance between the EM predictions from the National Centers for Environmental Prediction (NCEP) Climate Forecast System version 2 (CFSv2) and the observations represented by CFSv2 Reanalysis. The null hypothesis cannot be rejected in this study. Hence, we argue that the higher order statistics such as ensemble standard deviation are also needed to describe the forecast. We also show that removal of systematic errors that are a function of the forecast initialization month and lead time is a necessary pre-processing step. Finally, we show that CFSv2 provides useful ensemble climate forecasts from 0 to 9 month lead time in several regions.
Uncoupling the mechanisms of obesity and hypertension by targeting hypothalamic IKK-β and NF-κB

Obesity-related hypertension has become an epidemic health problem and a major risk factor for the development of cardiovascular disease (CVD). Recent research on the pathophysiology of obesity has implicated a role for the hypothalamus in the pathogenesis of this condition. However, it remains unknown whether the often-seen coupling of hypertension with obesity can also be explained by hypothalamic dysfunction, despite the emerging appreciation that many forms of hypertension are neurogenic in origin. Our studies here revealed that acute activation of the proinflammatory protein nuclear factor κB (NF-κB) and its upstream activator IκB kinase-β (IKK-β, encoded by Ikbkb) in the mediobasal hypothalamus rapidly elevated blood pressure in mice independently of obesity. This form of hypothalamic inflammation-induced hypertension involved the sympathetic upregulation of hemodynamics and was reversed by sympathetic suppression. Loss-of-function studies further showed that NF-κB inhibition in the mediobasal hypothalamus counteracted obesity-related hypertension in a manner that was dissociable from changes in body weight. In addition, we found that pro-opiomelanocortin (POMC) neurons were crucial for the hypertensive effects of the activation of hypothalamic IKK-β and NF-κB, which underlie obesity-related hypertension. In conclusion, obesity-associated activation of IKK-β and NF-κB in the mediobasal hypothalamus--particularly in the hypothalamic POMC neurons--is a primary pathogenic link between obesity and hypertension. Breaking this pathogenic link may represent an avenue for controlling obesity-related hypertension and CVD without requiring obesity control.
Evidence for a facultative mutualist nutritional relationship between the green coccoid alga Bracteacoccus sp. (Chlorophyceae) and the zoosporic fungus Rhizidium phycophilum (Chytridiomycota)

Symbiotic interactions between fungi and photosynthetic partners are common among derived fungal lineages. The only fungal-phototroph interactions thus far reported from the early diverging zoosporic fungi are parasitic in nature. Rhizidium phycophilum is a terrestrial, saprotrophic chytrid, which appears to be able to enter a facultative mutualism with a coccoid green alga in the absence of refractory organic material, such as pollen and chitin. Liquid and solid culturing methods were used in a series of differential fitness experiments in conjunction with microscopic analyses to characterize the interaction between R. phycophilum and the alga. The alga in this partnership is identified as a member of the genus Bracteacoccus. Under certain culturing conditions, algal cells grown in coculture with R. phycophilum were shown to grow larger and more prolifically than when cultured axenically under the same conditions. Additionally, dialysis experiments demonstrate that R. phycophilum does not parasitize Bracteacoccus sp., and can be cultured in media infused with unknown algal exudates. Rhizidium phycophilum and Bracteacoccus sp. represent the first facultative positive interaction between a zoosporic fungus and a photoautotroph and may prove a tractable system for modelling interactions between early fungi and plants.
Tetraspanins and cell membrane tubular structures

Tetraspanins regulate a variety of cellular functions. However, the general cellular mechanisms by which tetraspanins regulate these functions remain poorly understood. In this article we collected the observations that tetraspanins regulate the formation and/or development of various tubular structures of cell membrane. Because tetraspanins and their associated proteins (1) are localized at the tubular structures, such as the microvilli, adhesion zipper, foot processes, and penetration peg, and/or (2) regulate the morphogenesis of these membrane tubular structures, tetraspanins probably modulate various cellular functions through these membrane tubular structures. Some tetraspanins inhibit membrane tubule formation and/or extension, while others promote them. We predict that tetraspanins regulate the formation and/or development of various membrane tubular structures: (1) microvilli or nanovilli at the plasma membranes free of cell and matrix contacts, (2) membrane tubules at the plasma membrane of cell-matrix and cell-cell interfaces, and (3) membrane tubules at the intracellular membrane compartments. These different membrane tubular structures likely share a common morphogenetic mechanism that involves tetraspanins. Tetraspanins probably regulate the morphogenesis of membrane tubular structures by altering (1) the biophysical properties of the cell membrane such as curvature and/or (2) the membrane connections of cytoskeleton. Since membrane tubular structures are associated with cell functions such as adhesion, migration, and intercellular communication, in all of which tetraspanins are involved, the differential effects of tetraspanins on membrane tubular structures likely lead to the functional difference of tetraspanins.
Crystallization during hot-drawing of poly(ethylene terephthalate) film: influence of temperature on strain-rate/draw-time superposition

Abstract We have studied the crystallization of poly(ethylene terephthalate) during drawing at temperatures of 83, 90 and 96°C and at strain rates in the range 0.01–2.1 s −1 . Decreasing strain rate shifts the onset of crystallization to higher draw ratios and reduces the rate at which crystallinity increases with draw ratio, an effect that becomes more pronounced as draw temperature increases. When the degree of crystallinity is plotted against draw time, it becomes apparent that the effect of changing strain rate is simply to shift the curves along the log-time axis. The shift factor and the strain rate are related by a power law, and the value of the exponent, which reflects the rate of molecular relaxation at the draw temperature, rises with temperature at an increasing rate. Due to strain-rate/draw-time superposition, empirical equations permit prediction of the degree of crystallinity and the crystallization rate at any strain rate or temperature in the range studied from knowledge of draw time or draw ratio. The study also reveals that increasing draw temperature does not necessarily increase the draw ratio for onset of crystallization λ c as previously supposed: at sufficiently high strain rates, λ c decreases with increasing draw temperature.
Surgical inferior repositioning of the maxilla: Treatment considerations and comprehensive management

Abstract Despite numerous technical and biologic advances in the surgical-orthodontic correction of dentofacial deformities, inferior repositioning of the hypoplastic and/or deficient maxilla remains disturbingly unpredictable. Factors contributing to the success or failure of this surgical procedure have heretofore been poorly defined. This article reviews the salient clinical features, discusses the relevant treatment considerations, and prescribes a specific regimen for stable surgical inferior repositioning of the maxilla in persons with true vertical maxillary deficiency.
Precursors to onset clusters in acquisition.

Two lawful relationships involving word-initial onset clusters have been advanced in the acquisition literature; namely, that clusters imply affricates (Lleo & Prinz, 1996, 1997), and that liquid clusters imply a liquid distinction (Archibald, 1998). This study evaluated and extended the validity of these implicational laws in a population of 110 children (aged 3; 0 to 8; 6) with functional phonological delays who contributed extended speech samples for computational analyses. Results indicated that, for the most part, the composition of children's sound systems were in compliance with the proposed laws; however, there were noted asymmetries and apparent exceptions in the data. The asymmetries motivated an integration of the two laws to reveal a pattern of segmental-prosodic cyclicity consistent with deterministic models of phonological acquisition. The apparent exceptions highlighted the relevance of independent methodologies and offered a potential theoretical alternative with the Resolvability Principle as directions for future research.
Turbulence measurements from moving platforms

Two recent methods for making high-fidelity turbulence measurements from moving platforms are described and demonstrated. The first is a method for measuring profiles of near-surface turbulence from a wave-following 'SWIFT' buoy. The second is a method for measuring time series of turbulence from a submerged compliant mooring. Both approaches use coherent Doppler instruments and inertial motion units (IMUs). In the buoy method, wave motions (e.g., pitch, roll, and heave) are quantified via GPS and IMU measurements. These wave motions are not present in the turbulence observations, because buoy follows the wave orbital motion, and thus the turbulent velocities are processed in the wave-following reference frame. In the mooring method, IMU measurements track the mooring motions (e.g., strum and kiting) and these motions are removed in post-processing to obtain turbulent velocities in the fixed earth reference frame. These approaches successfully quantify turbulence in regions previously unavailable or limited by the noise and spatial aliasing of sampling from bottom-mounted platforms.
A note on manufacturing flexibility as a firm-specific dynamic capability

Abstract This paper addresses the important concept of flexibility in the context of the manufacturing firm. We identify a gap in previous efforts to directly connect the uncertainty in the environment and the flexibility of the firm. To address this gap, a new definition of manufacturing flexibility is proposed.
Hybrid CuO‐TiO2−xNx Hollow Nanocubes for Photocatalytic Conversion of CO2 into Methane under Solar Irradiation

Methane-producing hollow nanocubes: Hybrid CuO-TiO(2-x)N(x) hollow nanocubes have been synthesized by first depositing TiO(2) onto Cu(3)N nanocube templates, then heating in air to oxidize the Cu(3)N to CuO while concomitantly incorporating nitrogen into the TiO(2). The nanostructured CuO-TiO(2-x)N(x) material photocatalytically converts CO(2) into methane under solar irradiation.
Hierarchical Linear Modeling in Salary Equity Studies

A hierarchical linear model is compared with an ordinary least squares model for conducting salary-equity studies.
DNA-directed cell-free protein-synthesizing system of Bacillus subtilis

Abstract A cell-free coupled system of transcription and translation using cell extracts from Bacillus subtilis and DNA from phage SP82 has been developed. Under optimum conditions, it incorporated approx. 300 pmol methionine during a 1 h incubation. The activity of the system increased linearly as the concentration of S-150 supernatant fraction protein increased from 125 to 325 μg per assay. The optimum Mg 2+ concentrattion was 12.5–15 mM. Ribosomes required treatment with DNAase in order to reduce endogenous activity, but the S-150 fraction was kept DNAase-free to prevent degradation of exogenously added DNA. The coupled system was sensitive to inhibitors of RNA and protein synthesis. Kinetic studies showed that the number of pmol of nucleotides present in newly synthesized RNA increased linearly for the first 20-min reaction and that the rate of amino acid incorporation increased linearly for the first 30 min. Polyacrylamide gel electrophoresis of the in vitro synthesized products yielded a band pattern that closely resembled the pattern of early phage SP82 proteins produced in vivo.
The Oral Cephalosporins—A Review

There are currently six cephalosporins available in the United States for oral use. These agents possess a wide spectrum of activity, are relatively safe to use, and are effective for certain infections involving the respiratory tract, skin, and urinary tract. Nonetheless, in general, they offer no advantage over other classes of antimicrobial drugs and are far more expensive. As a result, the oral cephalosporins are not agents of first choice for the treatment of infection but should be reserved for use as alternative therapy.
An O(lg n) expected rounds randomized Byzantine generals protocol

Byzantine Generals protocols enable processes to reliably broadcast messages in the presence of faulty processes. These protocols are run in a system of consists of n processes, t of which are faulty. The protocols are conducted in synchronous rounds of message exchange. We show that, without using cryptography, for t = n/(3 + d), there is a randomized protocol with O(lg n) expected number of rounds. If we allow cryptographic methods, then, for t = n / (2 + d), there is a randomized protocol with O(lg n) expected number of rounds. This is an improvement on the lower bound of t + 1 rounds required for det … … previous result of t/lg n expected nu rounds for randomized protocols.
Validating Atmospheric Reanalysis Data using Tropical Cyclones as Thermometers

AbstractTemperatures in the upper troposphere of the atmosphere, near the tropopause, play a key role in the evolution of tropical cyclones (TC) by controlling their potential intensity (PI), which describes the thermodynamically based maximum TC intensity that the environment will support. Accurately identifying past trends in PI is critical for understanding the causes of observed changes in TC intensity, but calculations of PI trends using different atmospheric reanalysis products can give very different results, largely due to differences in their representation of upper-tropospheric temperatures. Without a means to verify the fidelity of the upper-tropospheric temperatures, PI trends calculated from these products are very uncertain.Here, a method is introduced to validate the upper-tropospheric temperatures in the reanalysis products by using the TCs themselves as thermometers. Using a 30-yr global dataset of TC cloud-top temperatures and three widely utilized atmospheric reanalysis products—Modern-...
Spirituality during alcoholism treatment and continuous abstinence for one year.

Objective:The primary aim of this prospective study was to examine the role of several aspects of spirituality in maintaining abstinence from alcohol for one year in persons treated for alcohol dep...
Size and surface charge significantly influence the toxicity of silica and dendritic nanoparticles

The influence of size, surface charge and surface functionality of poly(amido amine) dendrimers and silica nanoparticles (SNPs) on their toxicity was studied in immunocompetent mice. After systematic characterization of nanoparticles, they were administered to CD-1 (caesarean derived-1) mice to evaluate acute toxicity. A distinct trend in nanotoxicity based on surface charge and functional group was observed with dendrimers regardless of their size. Amine-terminated dendrimers were fatal at doses >10 mg/kg causing haematological complications such as disseminated intravascular coagulation-like manifestations whereas carboxyl- and hydroxyl-terminated dendrimers of similar sizes were tolerated at 50-fold higher doses. In contrast, larger SNPs were less tolerated than smaller SNPs irrespective of their surface functionality. These findings have important implications in the use of these nanoparticles for various biomedical applications.
Chip-to-chip fluidic connectors via near-field electrospinning

Site-specific, chip-to-chip fluidic connectors have been demonstrated via near-field electrospinning (NFES) in a fashion similar to the wire bonding technique in IC manufacturing. Electrospun polymer fibers function as the sacrificial material with deposition control better than 10 m in the planar direction to connect two separated chips. A coating process and sacrificial layer etching process are followed to make micro/nano fluidic channels of 50 nm~5 mum in inner diameter. Preliminary parameter and flow characterizations have been conducted. As such, this fabrication/packaging technology could enable on-chip and off-chip fluidic transportations and networks in MEMS applications, including bioMEMS and microfluidics.
Influence of sucrose on rumen fermentation pattern and milk fat content of cows fed a high-grain ration.

Abstract Milk fat content was not increased by replacing milo with sucrose at levels representing 5,10, and 15% of the dry matter in rations containing 10% alfalfa hay and fed in excess of National Research Council requirements. The experiment involving 16 cows was conducted in randomized block design. It consisted of a standardization period of two weeks, a transition period of four weeks, and a comparison period of sixteen weeks. During the standardization period the cows received ad libitum a ration comprised of 40% alfalfa hay (estimated net energy basis) and 60% ground milo plus minerals. There were no significant differences among the covariant-adjusted treatment means for milk and solids-corrected milk production, milk fat, and solids-not-fat content, or production efficiency. In the rumen contents pH was lower (P
A review of the critical heat flux condition in mini-and microchannels

With ever increasing power dissipation in electronic chips that are shrinking in size, cooling demands are becoming more severe. Forced air cooling is reaching its operational limits, and single-phase liquid cooling in microchannels has been able to accommodate the rising heat fluxes. Further increases in computing (chip) power suggest that a switch from single-phase to boiling heat transfer will be needed. A major impediment to using boiling or forced convective vaporization for such a cooling application is the limiting critical heat flux (CHF) condition. In this paper, the CHF condition in microchannels is reviewed. Data from the literature are discussed, and new data for a range of operating and geometric conditions are presented. Influencing factors, parametric trends, phenomenological models, and other aspects of the CHF condition are discussed.
A Review of: “Achieving and Sustaining Institutional Excellence for the First Year of College”

Through case studies, Barefoot and her fellow authors showcase 13 institutions “in which the first year has become a high priority and truly central to the collegiate experience” (p. xiv). These ca...
Neonatal Extravasation: An Overview and Algorithm for Evidence-based Treatment

Abstract The peripheral intravenous (PIV) catheter is the most used vascular access device for the administration of medications in hospitalized neonates, however 95% of PIV catheters are removed due to complications. Infiltration and extravasation are one of the most destructive complications to the neonate's fragile skin. This article reviews multiple aspects of infiltration and extravasation injury. First, starting at the cellular level the role of vesicants in vascular injury and its role triggering inflammation will be discussed, followed by a comprehensive review of vesicants and their mechanism of injury, by pH, osmolality or chemical composition, then an overview of the NICU nurses knowledge and actions to prevent infiltration and ending with the use of an evidence-based algorithm that was developed at one children's hospital to minimize injury caused by extravasations through targeted, prompt treatment.
Physical database design for data warehouses

Data warehouses collect copies of information from remote sources into a single database. Since the remote data is cached at the warehouse, it appears as local relations to the users of the warehouse. To improve query response time, the warehouse administrator will often materialize views defined on the local relations to support common or complicated queries. Unfortunately, the requirement to keep the views consistent with the local relations creates additional overhead when the remote sources change. The warehouse is often kept only loosely consistent with the sources: it is periodically refreshed with changes sent from the source. When this happens, the warehouse is taken off-line until the local relations and materialized views can be updated. Clearly, the users would prefer as little down time as possible. Often the down time can be reduced by adding carefully selected materialized views or indexes to the physical schema. This paper studies how to select the sets of supporting views and of indexes to materialize to minimize the down time. We call this the view index selection (VIS) problem. We present an A* search based solution to the problem as well as rules of thumb. We also perform additional experiments to understand the space-time tradeoff as it applies to data warehouses.
Teaching Research Integrity and Bioethics to Science Undergraduates

Undergraduate students in the Department of Biomedical Sciences at the University of South Alabama, Mobile, are required to take a course entitled “Issues in Biomedical Sciences,” designed to increase students' awareness about bioethical questions and issues concerning research integrity. This paper describes the main features of this course and summarizes the results of a survey designed to evaluate the students' perceptions about the course. A summary of this study was presented at the 2002 Conference on Research Integrity in Potomac, MD, sponsored by the Office of Research Integrity of the National Institutes of Health.
The Gaussian Interference Relay Channel with a Potent Relay

We consider the Gaussian interference channel with an intermediate relay. The relay is assumed to have abundant power and is named potent for that reason. A main reason to consider this model is to find good outerbounds for the Gaussian interference relay channel (GIFRC) with finite relay power. By setting the power of the relay constraint to infinity, we show that the capacity region is asymptotically equivalent to the case when the relay-destination links are noiseless and orthogonal to other links. The capacity region of the latter provides an outerbound for the GIFRC with finite relay power. We then show the capacity region of the former can be upper bounded by a single-input-multiple-output interference channel with an antenna common to both receivers. To establish the sum capacity of this channel, we study the strong and the weak interference regimes. For both regimes, we show that the upperbounds we find are achievable, thus establishing the sum capacity of GIFRC with the potent relay. Both results, in turn, serve as upperbounds for the sum capacity of the GIFRC with finite relay power. Numerical results show that the upperbounds are close to the known achievable rates for many scenarios of interest.
A Sedimentary Model for Determining Paleotidal Range

Prograding clastic tidal coastlines in embayed areas, lagoons, and open coasts generate a graded, fining-upward sequence of sediments. This graded sequence is produced by a distinct zonation of sediment transport processes across a clastic intertidal flat. These transport zones are (1) tidal bedload transport (producing subtidal sand), (2) combination of tidal bedload transport and emergence runoff prior to exposure (producing low tidal flat sand), (3) alternation of bedload and suspension sedimentation (producing midflat interbedded sands and muds), and (4) suspension sedimentation (producing high tidal flat muds and clays). The distinction between subtidal and low intertidal flat sands is achieved by identifying sedimentary structures indicating late-stage emergence runoff prior to exposure in the low tidal flat sands. The contact between these two sands, one with and the other without emergence runoff sedimentary structures, coincides with the postion of mean low water. The top of the graded, fining-upward sequence consists of clay-sized sediment and coincides with the level of mean high tide. Such prograded fining-upward sequences contain within them a preserved record of tidal range. In Holocene sediments, the thickness of the interval representing low tidal flat, midflat and high tidal flat sediments coincides with mean tidal range . In fossil equivalents, the thickness of similar sequences gives a quantitative measurement of paleotidal range.
A behavioral representation for Nyquist rate A/D converters

The authors present a behavioral representation for the class of Nyquist rate A/D (analog-to-digital) converters. The representation captures the nominal A/D behavior as well as all the statistical variations. The variations are classified into noise and process variations according to how these nonidealities affect the A/D behavior. To describe noise effects a joint probability density function is used. To describe behavioral effects due to process variations, use is made of a variance-covariance matrix, Sigma /sub t/, which is a generalization of the integral nonlinearity vector. Sigma /sub t/'s rank characterizes the testability of an A/D; its decomposition yields efficient strategies for A/D testing. Finally, parameter extraction results obtained from prototypes are presented. >
Comparative Evaluation of Antioxidant Reactivity between Ovariectomized and Control Urinary Bladder Tissue Using Ferric Reducing Ability of Plasma and Cupric Ion Reducing Antioxidant Capacity Assays

Objectives: In rabbits, ovariectomy has been shown to cause reduced blood flow to the bladder, increased free radical generation, and oxidative damage to the bladder. Thus, the antioxidant status of rabbits may play an important role in the damaging effects of ovariectomy. The present study analyzed total antioxidant content (TAC) in control, 14- and 28-day ovariectomized (Ovx) female rabbit bladders using both ferric reducing ability of plasma (FRAP) and cupric ion reducing antioxidant capacity (CURPAC) assays. Methods: Twelve weight- and age-matched virgin female New Zealand White rabbits (∼ 4.0 kg) were separated into three groups of four rabbits each. Group 1 received ovariectomy surgery for 14 days. Group 2 received ovariectomy surgery for 28 days. Group 3 received sham operations. Results: FRAP did not show any significant differences between either muscle and mucosa or control and Ovx samples. CUPRAC revealed higher TAC in the control mucosa compared to muscle and significantly decreased antioxidant levels in 14- and 28-day Ovx mucosal layers compared to the mucosa of the control rabbits. Conclusion: The CUPRAC method proved to be superior to the FRAP method for accuracy.
Performance comparison of asynchronous and synchronous code-division multiple-access techniques for fiber-optic local area networks

Synchronous code-division multiple access (S/CDMA) is investigated for fiber-optic local area networks. It is shown that the large bandwidth expansion required by spread-spectrum techniques, such as CDMA, can be accommodated by using a fiber-optic channel for transmission and incoherent optical signal processing for code generation and correlation. Prime sequence codes, previously developed for a fiber-optic network using (asynchronous) CDMA, are modified to fit a synchronous transmission format. A performance comparison of CDMA and S/CDMA systems reveals that S/CDMA can accommodate a larger number of subscribers and more simultaneous users than CDMA. An environment for which S/CDMA would be suited is discussed. >
Regulation of the elongation-termination decision at intrinsic terminators by antitermination protein N of phage lambda.

The mechanisms that control N-protein-dependent antitermination in the phage l life cycle have counterparts in the regulatory systems of other organisms. Here we examine N-dependent antitermination at the intrinsic tR 0 terminator of l to elucidate the regulatory principles involved. The tR 0 terminator consists of a sequence of six base-pairs along the template at which the transcription complex is sufficiently destabilized to make RNA release possible. Within this ‘‘zone of opportunity’’ for termination the termination efficiency (TE) at each template position is determined by a kinetic competition between alternative reaction pathways that lead either to elongation or to termination. TE values at each position within tR 0 have been mapped as a function of NTP concentration, and it is shown that N protein (in the presence of NusA and a nut site; the minimal system for N-dependent antitermination) can offset increases in TE that are induced by limiting the concentrations of each of the next required NTPs. By limiting NTP concentrations or working at low temperature we show that a significant effect of N within the minimal system is to increase the rate of transcript elongation three- to fivefold at most positions along the template. Assuming that a comparable increase in elongation rate applies at template positions within the terminator, we show that an increase of this magnitude is not sufficient to account for the antitermination efficiency observed and that an 100-fold stabilization of the transcription complex at intrinsic termination sites as a consequence of binding the N-containing antitermination sub-assembly must be invoked as well. A general method for partitioning TE effects in antitermination between changes in elongation rate and termination complex stability is demonstrated, based on competing free energy of activation barriers for the elongation and termination reactions. The analysis and utility of such mixed modes of transcriptional regulation are considered in general terms. # 1997 Academic Press Limited
Capacity analysis for parallel and sequential MIMO equalizers

It is well known that linear MMSE can outperform its zero-forcing counterpart. In combination with a successive interference canceller, MMSE can fully exploit the capacity of MIMO (multiple-input-multiple-output) channels [A.J. Viterbi, 1986, M.K. Varanasi, T. Guess, 1997]. In practice, however, such an advantage is compromised due to its implementation complexity and the requirement of accurate SNR estimate. Thus other equalizers such as zero-forcing may present an attractive alternative as long as the performance gap is tolerable. This motivates a need to quantify the tradeoff between MMSE and zero-forcing in both parallel and sequential structures. In this paper, the capacity performance of different equalization schemes is investigated, with closed-form formulas provided in terms of two key measures: capacity gaps and ratios. We also conclude that the capacity gain via structural choice (between parallel and sequential) far out-weights that via filter choice (between zero-forcing and MMSE). Indeed, the latter is found to be almost negligible for most practical SNR regions. It is also shown that the sequential zero-forcing equalizers can asymptotically reach the channel capacity when SNR approaches infinity, irrelevant of the detection order. Although this paper is focused on the flat-fading channels, the result is directly extendable to the ISI case by slicing the frequency band into infinitesimal stripes, each of which can be treated as flat.
Career HOPES: An Internet-delivered career development intervention

Career HOPES is an Internet-delivered group counseling intervention designed to facilitate occupational exploration and career decision making. The intervention includes automated interactive lessons and self-assessments, homework assignments, and group discussions in private online forums. A randomized, controlled experiment (N=64) was conducted to evaluate (a) the efficacy of Career HOPES and (b) the contribution of professional moderation of the online group discussions to outcomes. Participants in two treatment conditions showed greater gains than control condition participants in career decidedness as measured by the Occupational Alternatives Questionnaire (d=.54), occupationally relevant self-knowledge (d=.58), and emission of career exploration behaviors (d=.50). In one of the treatment conditions, the online group discussions were moderated by a psychologist with career counseling experience; in the other treatment condition, the discussions were unmoderated. Professional moderation resulted in better outcomes on several variables and greater overall satisfaction with the intervention.
THE SPECIFICATION AND TESTING OF A SEISMIC-REFRACTION SYSTEM FOR CRUSTAL STUDIES;

A new seismic-refraction system built for the U. S. Geological Survey for crustal studies has been tested in the laboratory and shown to meet strict performance specifications for broad frequency response, low noise, high gain, and high dynamic range. The inherent advantages of magnetic recording, with selective filtering on playback, were demonstrated in field tests by the recovery of weak events that otherwise would be obscured by high seismic noise.
Comparison of Soil Wetness Indices for Inducing Functional Similarity of Hydrologic Response across Sites in Illinois

Abstract The comparative ability of four soil wetness indices to normalize soil moisture dependence of rootzone fluxes across a range of sites in Illinois is investigated. The soil wetness indices examined are various transformations of the water stored in the top 30 cm of soil (W). The wetness index parameters used in the transformations include porosity, wilting point, and the maximum observed, mean, and standard deviation of W. The long-time average dependence of rootzone outflow (the sum of evapotranspiration, drainage, and runoff) on each index is measured using a new estimation technique based on conditional averaging of precipitation according to soil moisture level. For each soil wetness index, the dependence of mean outflow on that index is estimated at 17 sites and then averaged. The variance around the average curve is used as a measure of the ability of each index to induce functional similarity. Soil wetness indices based on statistical properties of soil moisture data (e.g., maximum observed...
Community Entrepreneurial Climate: An Analysis of Small Business Owners Perspectives

This article examines the determinants of community entrepreneurial climate from the perspectives of small business owners. Data were collected from a survey of 158 small business owners in twelve rural Missouri communities in 2003 and 2004. The results indicate that small business owners’ perceptions of fair treatment within their community, the level of local patronage, and the availability of business networks and high-speed internet have significant positive effects on their perceptions of community entrepreneurial climate. Community quality of life, proximity to metro areas, local government support, and the availability of business services and financial resources showed no statistically significant effects. Furthermore, small business owners from smaller communities were more likely to perceive their communities as having a low entrepreneurial climate.
The Network Analysis ‘Five-Number Summary’

How should you start when you want to do a network analysis in R? The answer to this question rests of course on the analytic questions you hope to answer, the state of the network data that you have available, and the intended audience(s) for the results of this work. The good news about performing network analysis in R is that, as will be seen in subsequent chapters, R provides a multitude of available network analysis options. However, it can be daunting to know exactly where to start.
The determination of serum iron and iron-binding capacity by atomic absorption spectroscopy.

The specificity and accuracy of atomic absorption spectroscopy (AAS) make the use of this technic suitable for the determination of iron in biologic materials. Determinations of iron by AAS in urine prove to be reasonably simple; however, considerable difficulties are encountered when this technic is applied to determinations of iron in serum. Direct analyses of serum, i.e., direct aspiration of the sample (or a dilution thereof) into the flame, may give erroneous results because of interferences by serum constituents and hemolysis. In our experience, direct analysis has been a useful technic in patients with acute iron poisoning with high serum iron levels. Data of sufficient accuracy were obtained within a few minutes after arrival of such patients at the hospital. For the determination of serum iron in the range below 200 pg. per 100 ml., we developed an AAS method based on the chelation of iron and subsequent extraction of the complex into an organic solvent, which then is aspirated into the flame. The method has a precision of better than 1 ng. per 100 ml. of iron.
Design and Evaluation of a 2-DOF Instrumented Platform for Estimation of the Ankle Mechanical Impedance in the Sagittal and Frontal Planes

This paper describes the fabrication and initial evaluation of a vibrating platform with two degrees of freedom (DOF) to estimate the human ankle's mechanical impedance in two DOFs; namely dorsiflexion–plantarflexion (DP) and inversion–eversion (IE). The device consists of an actuation and a force plate module. The actuation module generates torque perturbations up to 168 N·m in DP and 26 N·m in IE in the force plate module using Bowden cables. This provides a low-profile system that can be installed in a walkway. The frame of the force plate module rotates in two DOFs, applying torque perturbations to the human ankle in DP and IE. The ankle's rotations are measured using a motion capture camera system. The analytical and numerical approaches for estimation of the ankle's torques, rotations, and impedances are presented. A system validation using a mockup was conducted to verify the system's ability to estimate the impedance of a physical system in two DOFs. The developed system was capable of identifying the mockup's physical properties up to 15 Hz. The mockup's impedance magnitude at 0.9 Hz using a stochastic identification method was shown to be within 1.68% and 0.54% of the mockup's stiffness in DP and IE, respectively.
Effect of hibernation and cold torpor on tissue catecholamine content.

SummaryHibernation in the ground squirrel is accompanied by increases in hepatic and kidney catecholamine content and no change in cardiac content. Cold torpor in the turtle was not accompanied by significant changes in catecholamine content of heart, liver or kidney.Our thanks to Dr. Douglas E. Smith of the Division of Biological and Medical Research, Argonne National Laboratory, for supplying the ground squirrels.