cssi/SciSciGPT-SciSciNet huggingface dataset:
Biosensors: a tutorial review

This paper discusses various biosensors in detail, where the biosensor consists of bioelement and a sensor element. The bioelement may be an enzyme, antibody, living cells etc., and the sensing element may be electric current, electric potential, and so on. This survey initially introduces the basic concept of the biosensors. High-level overviews of different types of biosensors are given and the working principles, constructions, advantages and applications of many biosensors are also presented. In addition to these MEMS have given rise to a whole new class of biosensors which involve the transduction of mechanical energy and are based on mechanical phenomena.
Simplified modeling procedure for inverter-based islanded microgrid

A methodology to model renewable energy inverter based microgrids is developed in this paper. Most of the renewable energy sources either produce DC directly (solar photovoltaics or fuel cells) or create DC before inversion to the utility (wind or hydroelectric turbines). The DC electric energy is first conditioned and then converted into the AC grid through an inverter. The proposed method models the dynamics of the DC and the AC sides of the inverters forming a microgrid. Equivalent circuit models for the both sides of the inverters are developed and power flow between them is represented by the dependent voltage and current sources. The effectiveness of the proposed modeling technique has been tested for transient and steady state conditions. Both simulations and experimental results verified the accuracy of the proposed modeling methodology.
Swelling-activated chloride channels in cardiac physiology and pathophysiology.

Abstract Characteristics and functions of the cardiac swelling-activated Cl current ( I Cl,swell ) are considered in physiologic and pathophysiologic settings. I Cl,swell is broadly distributed throughout the heart and is stimulated not only by osmotic and hydrostatic increases in cell volume, but also by agents that alter membrane tension and direct mechanical stretch. The current is outwardly rectifying, reverses between the plateau and resting potentials ( E m ), and is time-independent over the physiologic voltage range. Consequently, I Cl,swell shortens action potential duration, depolarizes E m , and acts to decrease cell volume. Because it is activated by stimuli that also activate cation stretch-activated channels, I Cl,swell should be considered as a potential effector of mechanoelectrical feedback. I Cl,swell is activated in ischemic and non-ischemic dilated cardiomyopathies and perhaps during ischemia and reperfusion. I Cl,swell plays a role in arrhythmogenesis, myocardial injury, preconditioning, and apoptosis of myocytes. As a result, I Cl,swell potentially is a novel therapeutic target.
The North Atlantic Ocean during the last deglaciation

Abstract The last deglacial warming of the high-latitude North Atlantic Ocean (40–65°) occurred in three discrete steps: in the southeast and central regions at 13 000 B.P.; in the central and northern sectors at 10 000 B.P.; and in the western (Labrador Sea) sector between 9000 and 6000 B.P. This regionally time-transgressive sequence was punctuated by a major cooling and polar front readvance from 11 000 to 1000 B.P.; this briefly returned most of the high-latitude North Atlantic to almost full-glacial temperatures. Carbonate productivity levels reached minimum values from 16 000 B.P. to 13 000 B.P. and then gradually rose, reaching maximum values in the Holocene at about 6000 B.P. We interpret these changes in carbonate productivity as indicating a major influx of products of glacial wastage (meltwater and icebergs) from 16 000 to 13 000 B.P., with considerably reduced influx after 13 000 B.P. Combined with evidence for meltwater influx to the Gulf of Mexico via the Mississippi River, this suggests that the bulk of volumetric deglaciation in the Northern Hemisphere occurred considerably earlier than the main areal retreat of ice-sheet limits. This implies that the still-extensive ice sheets in the Northern Hemisphere were relatively thin by 13 000 B.P. Because there is no palynologic evidence of unusual atmospheric warming on the southern margins of the ice sheets before 13 000 B.P., we infer that this early phase of rapid ice disintegration occurred largely by iceberg calving and marine downdraw. We also infer that from 16 000 to 13 000 B.P. low winter insolation combined with a low-salinity meltwater layer to form sea ice south to 50°N; after that date, the winter sea-ice cover diminished significantly. We infer from this that the critical flux of winter moisture to the ice sheets was largely cut off from 16 000 to 13 000 B.P. and still significantly suppressed after 13 000 B.P. Moisture starvation thus hastened the disintegration of Northern Hemisphere ice masses. The brief but strong oceanic cooling roughly coincident with the European Younger Dryas (11 000 to 10 000 B.P.) appears to mark a major influx of tabular icebergs from a disintegrating Arctic ice shelf, perhaps enhanced by external forcing at higher frequencies (2500 yr).
Solid-state and Vacuum Electron Device (VED) Radars - Past, Present and Future

This paper discusses the technological development of microwave vacuum electron devices and radar systems. Historical developments since WW-2 are sighted up to recent trends towards the future technological development
Crisis Intervention Team (CIT) Programs in Rural Communities: A Focus Group Study

The Crisis Intervention Teams model (CIT) was originally developed as an urban model for police officers responding to calls about persons experiencing a mental illness crisis. Literature suggests that there is reason to believe that there may be unique challenges to adapting this model in rural settings. This study attempts to better understand these unique challenges. Thematic analysis of focus group interviews revealed that there were both external and internal barriers to developing CIT in their respective communities. Some of these barriers were a consequence of working in small communities and working within small police departments. Participants actively overcame these barriers through the realization that CIT was needed in their community, through collaborative efforts across disciplines, and through the involvement of mental health advocacy groups. These results indicate that CIT can be successfully implemented in rural communities.
Structural Relaxation Time of Bulk and Fiber Silica Glass as a Function of Fictive Temperature and Holding Temperature

The structural relaxation times of silica glass, both bulk glass and fiber glass at various fictive temperatures, were estimated at selected temperatures. The structural relaxation time of a glass is needed to estimate the rate of change of various glass properties in the glass transition temperature range. Traditionally, the Tool-Narayanaswamy model, in which activation energy of the relaxation time is divided into two parts, one representing the fictive temperature effect and the other representing the temperature effect, has been used. The model can explain the property changes of glass in the glass transition temperature range well when the change of the fictive temperature is small, but the model fails when the change of the fictive temperature is large, as was the case when a fiber sample was heat treated close to the glass transition temperature. The structural relaxation times estimated in the present work exhibited activation energies that varied with fictive temperature, unlike the assumption in the Tool-Narayanaswamy model. On the other hand, the relaxation time for both bulk glass and fiber glass exhibited the same temperature and fictive temperature dependence within experimental error. From these observations, one can see the source of discrepancy between the Tool-Narayanaswamy model and experimental data when the change in fictive temperature is large.
Large volume ultrafiltration for acute decompensated heart failure using standard peripheral intravenous catheters.

Abstract Background Ultrafiltration for decompensated heart failure has recently generated significant clinical interest with the development of a portable machine that does not require an intensive care or dialysis unit. This case series was designed to demonstrate the feasibility and effectiveness of performing large volume ultrafiltration via peripherally inserted standard intravenous (IV) catheters in patients with acute decompensated heart failure. Methods and Results Nine hospitalized patients with decompensated heart failure underwent peripheral ultrafiltration (PUF) therapy with peripheral IV catheters. The mean length of time of PUF therapy was 33.3 ± 20.0 hours with a mean volume removed of 7.0 ± 4.9 L. All patients experienced a statistically significant mean weight loss of 6.2 ± 5.0 kg, P = .01. There was no statistically significant change in renal function. Conclusion We report the first successful implementation of ultrafiltration via standard peripheral IV catheters to remove a large volume of fluid over an extended period of time reliably in a small group of patients. The ability to use PUF therapy via peripheral IV catheters will potentially allow this therapy to be implemented more easily in a variety of care settings to treat patients with resistant heart failure.
Putting Charity to the Test: A Case for Field Experiments on Giving Time and Money in the Nonprofit Sector

Most nonprofit organizations rely on gifts of time and money to support their operations. However, research by nonprofit scholars on the behavioral mechanisms of charity remains underdeveloped. One...
An updated estimate for energy use in U.S. food production and policy implications

In this work we estimate the amount of energy required to produce the food consumed in the United States in 2002 and 2007. Data from government sources and the scientific literature were used to calculate the energy intensity of food production from agriculture, transportation, manufacturing, food sales, storage and preparation. Most data were from 2002; consequently we scaled all data from other years to 2002 by using ratios of total energy consumption in 2002 to total energy consumption in the year data were reported. We concluded that food production required at least 7,880±733 trillion BTU in 2002 and 8,080±752 trillion BTU of energy in 2007, over a third of which came from food handling in homes, restaurants and grocery stores. The energy used to produce food represents approximately 8% of energy consumption. Our estimate is for the energy required to produce the food consumed in the United States and takes into account food imports and exports. To account for net food exports in the agriculture sector we calculated values for the energy intensity of ten food categories and then used the mass of domestic food consumption in each category to calculate the energy embedded in the food consumed in the United States. The amount of energy required to produce the food consumed in the United States has policy implications because it is a substantial fraction of total energy consumption and is responsible for a commensurate amount of greenhouse gas emissions. There are many opportunities for decreasing the energy intensity of food production at all steps of the food system. Education of the public and policy measures that promote energy efficiency in the food sector have the potential for decreasing food waste and the energy intensity of the food system.Copyright © 2010 by ASME
Productivity paralysis and the complexity problem: Why do centrally planned economies become prematurely gray?

Abstract We develop a theory of the Soviet productivity growth slowdown that attributes it to difficulties encountered by systems of central planning as the economy becomes more complex. Shortages become more disruptive as the economy modernizes, forcing the economy to operate at an increasing distance from its production possibility frontier. The model also supports the widely held notion that consumer welfare suffers in Soviet-type economies as consumers' needs become increasingly sophisticated.
Early mouse embryos produce and release factors with transforming growth factor activity

Previous studies have shown that extracts from mouse embryos at mid and late stages of development contain factors that exhibit transforming growth factor activity. The work reported here demonstrates that cultured mouse embryos at significantly earlier stages of development produce and release factors that exhibit the characteristic property of transforming growth factors. Specifically, the data demonstrate that embryos cultured from the blastocyst stage in serum-containing medium or in serum-free medium release factors that promote the anchorage-independent growth of normal rat kidney fibroblasts. It is shown that these factors are produced and released by cells derived from the inner cell mass and by trophoblasts. The precise developmental stage when production of these factors first begins has not been determined but our findings suggest that these factors are produced by cell types associated with early postimplatation embryos.
Mg Substitution Clarifies the Reaction Mechanism of Olivine LiFePO4

Understanding the reaction mechanism of olivine compounds as electrode materials for lithium lithium-ion batteries have has received much attention recently. The question whether olivine LiFePO4 undergoes two-phase or non-nonequilibrium single-phase reaction during electrochemical processes has taken center stage in the understanding of the faster reaction kinetics observed in this material. Here, the lithiation/delithiation mechanism of Mg Mg-substituted LiFePO4 using high high-resolution X-ray diffraction(XRD), transmission electron microscopy(TEM), and electrochemical measurements is reported. Ex situ partially (de)lithiated olivine- LiMg0.2Fe0.8PO4 show the existence of stable equilibrium intermediate phases as characterized by the presence of more than two phases and broadness of diffraction peaks. Electron energy loss spectroscopy profiles across individual nanoparticles further confirm uniform lithiation with a constant Fe–L3 energy measured across each nanoparticle, suggestive of solid solution behavior in individual particles. In addition, a continuous shift in the diffraction peak position is observed even in the “two-phase” region in the ex situ electrochemical (de)lithiated electrodes.
Supervised coverage control of multi-agent systems

In this paper, we consider a dynamic coverage problem for multi-agent systems, where the main objective of a group of mobile agents is to explore a given compact region. We propose a novel control scheme, where we introduce a supervisor that assists a group of agents with the centralized coverage control law and the global trajectory tracking control law. The coverage control law ensures the coverage task is done until the agents end up in local minima, and when they do, the global trajectory tracking control law ensures that the agents are deployed to uncovered regions. Our control scheme is designed to be decoupled such that only one control law is active at a given time. In addition to the coverage objective, we design control laws for coverage agents to avoid collisions and maintain proximity to a supervisor. Moreover, we utilize feedback linearization to use the proposed control scheme for coverage control of kinematic unicycle agents. We validate our approach via numerical simulations.
Breast reconstruction after mastectomy

Abstract The management of the woman with breast cancer who requires mastectomy should involve a multidisciplinary approach which includes close collaboration between the oncological surgeon, the medical oncologist, the radiation oncologist and the reconstructive surgeon. The reconstructive surgeon can be a useful source of information for the patient with respect to the available options for breast reconstruction as well as appropriate techniques and timing. Current evidence supports the use of immediate breast reconstruction which can be performed either by specialist breast surgeons who are trained in both oncological and reconstructive surgery, or by a plastic surgeon. Advances have made reconstruction possible for almost all patients. The goals of breast reconstruction include creation of a long lasting, natural breast which meets the psychological and aesthetic needs of the patient without major morbidity at the donor site or compromise of sound oncolgic management. Autologous tissue reconstruction using the TRAM flap has become the preferred method in the USA due to the excellent results which are achieved without the need for silicone implants. Although these procedures are not without complications, careful patient selection and modifications of the technique have added to breast reconstruction safety and reliability. Current evidence supports the use of immediate breast reconstruction which can be performed either by specialist breast surgeons who are trained in both oncological and reconstructive surgery or by a plastic surgeon.
Polymer–surfactant complexation as a generic route to responsive viscoelastic nanoemulsions

We present a new scheme for imparting thermoreversible viscoelasticity to oil-in-water nanoemulsions based on polymer–surfactant self-assembly in solution. Specifically, bridging of polymer-induced micelles in the aqueous phase give rise to a transient network of interdroplet bridges without compromising colloidal stability. Characterization of the structure, dynamics, and rheological properties over a broad range of material chemistries and compositions suggests rules for controlling the resulting viscoelasticity. Remarkably, the linear viscoelasticity of these systems exhibits time–temperature superposition, which is purely driven by dynamics without noticeable structure changes. This allows quantification of an activation energy for network formation, which is correlated with the viscoelastic properties across a number of parameters, including polymer and surfactant concentration as well as droplet size. However, a complex dependence of the activation energy on fluid composition distinguishes these novel viscoelastic nanoemulsions from other types of transient gels, and we reconcile their behaviour with established mechanisms of polymer–surfactant complexation.
Insights into the mechanism of initial transcription in Escherichia coli RNA polymerase

It has long been known that during initial transcription of the first 8-10 bases of RNA, complexes are relatively unstable, leading to the release of short abortive RNA transcripts. An early "stressed intermediate" model led to a more specific mechanistic model proposing "scrunching" stress as the basis for the instability. Recent studies in the single subunit T7 RNA polymerase have argued against scrunching as the energetic driving force and instead argue for a model in which pushing of the RNA-DNA hybrid against a protein element associated with promoter binding, while likely driving promoter release, reciprocally leads to instability of the hybrid. In this study, we test these models in the structurally unrelated multisubunit bacterial RNA polymerase. Via the targeted introduction of mismatches and nicks in the DNA, we demonstrate that neither downstream bubble collapse nor compaction/scrunching of either the single-stranded template or nontemplate strands is a major force driving abortive instability (although collapse from the downstream end of the bubble does contribute significantly to the instability of artificially halted complexes). In contrast, pushing of the hybrid against a mobile protein element (σ3.2 in the bacterial enzyme) results in substantially increased abortive instability and is likely the primary energetic contributor to abortive cycling. The results suggest that abortive instability is a by-product of the mechanistic need to couple the energy of nucleotide addition (RNA chain growth) to driving the timed release of promoter contacts during initial transcription.
First Report of Aerial Blight Caused by Pythium myriotylum on Tomato in Florida.

In September 1996 and 1997, diseased tomato seedlings were observed with symptoms of an aerial watery rot on leaves, petioles, and stems. Tomato cvs. Sanibel and 10097 from commercial fields in southwest Florida (Collier and Lee counties) and west central Florida (Manatee County) exhibited similar symptoms that occurred at an incidence of 15 to 18% about 4 weeks after transplanting and resulted in plant death. Microscopic examination of symptomatic tissue revealed the presence of mycelium and oogonia typical of Pythium spp. A fungus was consistently isolated from four plants sampled from each site onto a medium selective for Pythium spp. and maintained in pure culture on V8 juice agar at 28°C. The isolates were identified as Pythium myriotylum Drechs. based on the following morphological data: lobate sporangium, 12 to 13 μm wide; vesicle 15.4 to 19.4 μm in diameter; exit tube 54 to 90 μm long, oogonium 23 to 30 μm in diameter; and oospore 21 to 26 μm in diameter (1,2). Pathogenicity tests were conducted with two isolates from diverse regions within Florida by spray inoculating the leaves and shoots of 6- to 8-week-old tomato seedlings with a sporangial suspension of 1 × 104 sporangia per ml. Noninoculated plants served as controls. Plants had 24 h of pre- and post-dark period, day/night temperatures of 28/21°C, a 14-h photoperiod, and near 100% relative humidity in a growth chamber. The foliage of inoculated tomato plants exhibited symptoms identical to those observed in field samples 24 h after inoculation and 100% mortality within 72 h. The reisolated fungus was morphologically identical to the original isolate. Noninoculated plants remained asymptomatic. The unusual rainfall recorded at some sites, such as in Manatee County in September 1997, was 36% higher than the 40-year average and may have contributed to the incidence of this previously undescribed foliar blight. References: (1) Anonymous. C.M.I. Descriptions of Pathogenic Fungi and Bacteria No. 118. (2) T. Watanabe. Pictorial Atlas of Soil Fungi. Lewis Pub., London. p. 71.
A heterogeneous tissue model for measurement of regional blood perfusion in the myocardium using inert gas isotopes

Abstract Inert gas isotopes are finding increasing application in the measurement of blood perfusion in the capillary beds of muscle, especially the myocardium. When measuring blood perfusion of the myocardium, washout curves are first produced by precordial monitoring of isotope activity following intracoronary artery injection of an inert gas isotope dissolved in saline. The washout curve data are then applied to a mathematical model to yield blood perfusion rate. Present models for this purpose either ignore any diffusive effects of gas movement (Kety-Schmidt model), or diffusive effects are accounted for by weighting the calculated perfusion value (Zierler's height-over-area technique). A new model is described here for convective and diffusive movement of an inert, nonpolar gas in myocardial tissue. A digital computer simulation of the model equations is used both to simply the model and to show agreement between the model response and experimental 133 Xe washout curves from normal and infracted canine hearts. The model assumes that the tail of the washout curves (portion after roughly 1.5 minutes) is caused by a heterogeneous, diffusion-limited tissue structure. The model provides two parameters which can be adjusted to washout curve data using model-matching techniques. These are perfusion rate, and a parameter which is an index of the diffusive nature of the particular myocardial area under study.
Pattern of distribution of acetylcholinesterase in the cerebellar cortex of the pond turtle, with emphasis on parallel fibers. A histochemical and biochemical study.

the cerebellar cortex of the pond turtle (Pseudemys scripta elegans) was analyzed with histochemical methods for the enzyme acetylcholinesterase (AChE) in the light and the electron microscope. The glomeruli in the granular layer were moderately AChE positive throughout the cerebellum. The molecular layer, however, showed a peculiar pattern of AChE distribution. While in the rostral portion of the cerebellum the molecular layer was uniformly unstained. AChE reaction product was present at the caudal tip even after relatively short incubation. This reaction product most caudally occupied the whole molecular layer and extended for about 1 mm in the rostral direction forming three or more bands parallel to the cerebellar pial surface alternating with AChE negative zones. Light and electron microscopy indicated that this enzyme is related to parallel fibers. An unusual stacking arrangement of parallel fibers that may explain the formation of the AChE positive bands is discussed. To ascertain whether the AChE positivity is an indicator of cholinergic synapses, radiochemical assays for AChE and choline acetyltransferase (ChAC) were performed. The results of these assays confirmed that there are significantly higher levels of AChE in the caudal molecular layer than in the rostral molecular layer, but showed that the levels of ChAC are extremely low in both regions, thus suggesting that the AChE in the caudal molecular layer is involved with functions unrelated to cholinergic transmission. The granular layer contained slightly higher concentration of both AChE and ChAc than either the rostral or caudal molecular layer, but still not high enough to definitely establish the presence of a cholinergic system. It is suggested that the AChE in the caudal portion of the turtle cerebellum marks a region of continuing growth in adult animals.
Personality and Creativity in Art and Writing: Innovation Motivation, Psychoticism, and (Mal)Adjustment

Undergraduates (N = 68) completed inventories measuring innovation motivation (need to be different and innovation expectancy), psychoticism, extraversion, neuroticism, and symptomatic distress, as well as a sentence completion measure of adjustment. They also wrote lyric poems using an associative procedure and completed house–tree–person drawings. Poems were scored for originality and arousal potential and independently judged for quality by two college writing instructors. Drawings were scored for original features and independently judged for quality by two art therapists. The need to be different and current adjustment problems correlated significantly with both originality scores and judged creativity on both tasks, often interacting to explain much of the variance in creativity. Innovation expectancy and psychoticism displayed significant correlations with some creativity measures. Originality scoring and expert judgment correlated well on both tasks. Originality and judged creativity correlated si...
Primary adenocarcinoma of the upper oesophagus

Adenocarcinoma of the upper one-third of the oesophagus is an uncommon entity. A review of the literature reveals 20 reported cases. This paper reports an additional case. The lesion may arise from oesophageal glands, foci of ectopic gastric mucosa, or a Barrett's oesophagus. In contrast with squamous cell carcinomas submucosal spread is not prominent; however, transverse penetration through the oesophageal wall is common. The prognosis is grave. Treatment modalities that have been employed include supportive care, surgery alone, pre-operative radiation therapy and surgery and radiation therapy alone. Survival statistics produced by these various regimens are similar. There is little documented evidence for the radioresponsiveness of primary adenocarcinoma of the oesophagus. The case described demonstrates marked tumour regression following a course of external radiotherapy as shown by serial oesophagrams. Optimum treatment for adenocarcinoma of the upper oesophagus remains to be determined. It is felt that the role of radiation therapy should be further evaluated.
VEGETATIVE ESTABLISHMENT AND EXPANSION BY THE MYCOBIONT OFCLADINA SUBTENUIS

Abstract Cladina subtenuis establishes and expands by mechanisms of the thallus mycobiont. Vegetative reproduction occurs through thallus fragmentation, branch ‘ de-differentiation ’, and the extension of the underground prothallus. Establishment hyphae can be considered as any hyphae that provide the mechanism for these modes of clonal thallus extension. They may originate in various parts of the thallus, laterally on branch surfaces, at the growing tips of branches, or from the inner fungal layers of the podetium. The thallus of C. subtenuis is structurally and functionally plastic. Parts of the photosynthetic lichen thallus can transform into non-photosynthetic fungal aggregations, and non-photosynthetic aggregations may re-establish as a photosynthetic lichen thallus. These activities expand the area occupied by the clone, and potentially increase its photosynthetic surface.
Decentralized CFAR signal detection

The authors develop the theory of CA-CFAR (cell-averaging constant false-alarm rate) detection using multiple sensors and data fusion, where detection decisions are transmitted from each CA-CFAR detector to the data fusion center. The overall decision is obtained at the data fusion center based on some k out of n fusion rule. For a Swerling target model I embedded in white Gaussian noise of unknown level, the authors obtain the optimum threshold multipliers of the individual detectors. At the data fusion center, they derive an expression for the overall probability of detection while the overall probability of false alarm is maintained at the desired value for the given fusion rules. An example is presented showing numerical results. >
In search of user privacy protection in ubiquitous computing

Participatory applications provide users with value-added and reusable information; however, collection of this information comes at the expense of the participants' privacy. Preserving the mobile participants' privacy is a key concern of mobile computing. This paper outlines current participatory application system model, privacy weaknesses, and existing privacy enhancing technologies. Next, it proposes a study to address mobile privacy protection by educating participants of exploitable privacy areas of their participatory applications. The contribution of the paper is two-fold: it provides a review of the existing privacy weaknesses of PS applications and demonstrates that participants' wanting to know more about these weaknesses warrants further study.
The Phase Change in an Artificial Supercooled Cloud upon Heterogeneous and Homogeneous Nucleation

Abstract A modified version of the Continuous Small Particle Sampler was used to obtain cloud particle samples of the phase change in a cloud chamber. The effects of silver iodide (AgI) and dry ice (CO2) were studied under similar conditions. Nucleation by AgI produced evidence which followed heterogeneous nucleation theory and crystal growth-rate observations. The dry ice seeding, plus a comparison with natural samples, illustrated Mason's homogeneous nucleation theory. Finally, total water content balances were computed and depict the water content of ice, liquid water content, and water vapor content proportions for each seeding.
Temporal Exposure to Chondrogenic Factors Modulates Human Mesenchymal Stem Cell Chondrogenesis in Hydrogels

Tissue engineering utilizes scaffolds containing chondrogenic cells to promote cartilage development at a clinically relevant scale, yet there remains a limited understanding of the optimal conditions for inducing differentiation and matrix production. We investigated how cell density and temporal exposure to chondrogenic factors impacted chondrogenesis of human mesenchymal stem cells (hMSCs) encapsulated in poly(ethylene glycol) diacrylate hydrogels. We found maximal proteoglycan and collagen production in constructs seeded between 10 and 25 × 10(6) cells/mL. Matrix deposition was significantly less per cell in constructs seeded at either higher or lower densities, indicating that paracrine communications may remain important despite loss of direct cell-cell contact. In vitro chondrogenesis of hMSCs was first accomplished using pellet cultures and a defined medium containing transforming growth factor (TGF)-β1 and dexamethasone. The differentiation of hMSCs in hydrogels also required initial exposure to TGF-β1, with no chondrogenic matrix produced in its absence. If TGF-β1 was initially included for at least 7 days, its removal impacted collagen production per cell but also lead to an increase in cell number, such that total collagen deposition was equivalent to controls when TGF-β1 was included for at least 3 weeks. Further, proteoglycan content per construct was higher at 6 weeks after removal of TGF-β1 at any time. In contrast to TGF-β1, dexamethasone was not required for chondrogenesis of hMSCs in hydrogels: there was no difference in matrix deposition between hydrogels cultured with or without dexamethasone. Further, without dexamethasone, SOX9 gene expression was higher during early chondrogenesis and there was a significant reduction in collagen I deposition, suggesting that a more hyaline cartilage phenotype is achieved without dexamethasone. Collagen content at 6 weeks was lower if dexamethasone was excluded after the first 7 days, but was equivalent to control if dexamethasone was included for 2 weeks or longer. Proteoglycan deposition was unaffected by dexamethasone exclusion. These results indicate that modulating exposure to TGF-β1 is beneficial for cell survival/proliferation and matrix production from hMSCs in hydrogels, and that not only is dexamethasone dispensable but also its exclusion may be advantageous for forming hyaline cartilage.
Lexical Organization and Phonological Change in Treatment

Word frequency and neighborhood density are properties of lexical organization that differentially influence spoken-word recognition. This study examined whether these same properties also affect spoken-word production, particularly as related to children with functional phonological delays. The hypothesis was that differential generalization would be associated with a word's frequency and its neighborhood density when manipulated as input in phonological treatment. Using a multiple baseline across subjects design, 8 children (aged 3;10 to 5;4) were randomly enrolled in 1 of 4 experimental conditions targeting errored sounds in high-frequency, low-frequency, high-density, or low-density words. Dependent measures were generalization of treated sounds and untreated sounds within and across manner classes as measured during and following treatment. Results supported a hierarchy of phonological generalization by experimental condition. The clinical implications lie in planning for generalization through the i...
The use of virologically compromised organs in liver transplantation

The present organ donor crisis has led to accepted use of organs from donors infected with hepatitis C virus (HCV) and hepatitis B virus (HBV). Although capable of transmitting disease, these grafts offer opportunities to expand the donor pool for certain populations. Anti-HBc positive grafts can be used if care is taken to provide prophylaxis. Good quality grafts from HCV+ donors may be used in recipients who are themselves HCV+ with good outcomes.
Temporal Variability of the Large-Scale Geostrophic Surface Velocity in the Northeast Pacific*

Abstract Data from Argos-tracked mixed layer drifters in fall and winter 1987 (49 drifters) and 1989 (16 drifters) are used to investigate the differences in the large-scale surface velocity and eddy activity in the northeast Pacific. The velocities were corrected for wind-induced slippage and corrected for wind-driven (Ekman) flow by matching an Ekman model to the observed currents. The model, which explains 15%–30% of the variance, indicates that the currents are at 60° to the right of the wind. The magnitude of the currents is 30% of the magnitude of the wind stress. In 1987–88, the geostrophic motion in the region from 46.5° to 48.5°N, 142° to 133°W was characterized by an eastward flow of 0.9 (±0.4) cm s−1 and a northward flow of 0.7 (±0.4) cm s−1. In 1989–90, for the same region, the geostrophic eastward component was 3.8 (±0.5) cm s−1, more than four times as large as in 1987–88, and the northward component was 0.3 (±0.5) cm s−1. In this region ageostrophic contributions to the velocities are small...
Quantum and semiclassical calculations of gas-surface energy transfer and sticking

In this paper we review some recent models for gas-surface scattering in which the gas particle can interact and exchange energy with the vibrational modes of the solid. Probabilities for energy transfer and sticking are computed for He, Ne, and Ar incident on a Cu surface, for a number of particle energies and surface temperatures. All of the models are applied to the same set of systems, and the results are compared. In all cases the lattice vibrations are treated quantum mechanically. A close-coupling approach which includes only single-phonon processes is presented. It is accurate for He and H2, and Ne at low energies and temperatures. Two common approaches to the problem based on an uncorrelated particle-bath state, the forced oscillator and time dependent Hartree method, are discussed. They are compared with each other and with the close-coupling calculation in the one-phonon limit. Mean field approaches which attempt to improve upon these zero-correlation models are presented and compared with the above models. A one-phonon multiconfiguration self consistent field model is also presented. The nature of atom-surface sticking is examined over a wide range of energies, temperatures, and masses.
Management of Chronic Obstructive Pulmonary Disease with Tiotropium Bromide

In COPD, pathologic upregulation and stimulation of muscarinic (M) receptors contribute to bronchospasm, mucus hypersecretion and possibly airway remodeling. Tiotropium bromide (brand name Spiriva; Boehringer Ingelheim/Pfizer) inhalational powder was approved by the US Food and Drug Administration in January 2004 for the long-term, once-daily, maintenance treatment of bronchospasm associated with chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema. Tiotropium is recommended by the Global initiative for Chronic Obstructive Lung Disease (GOLD) as a first-line therapeutic in treating chronic moderate and severe COPD and is the only long acting inhaled anti-muscarinic (anti-cholinergic) therapy available for the treatment of COPD in the USA. The primary functional effect of tiotropium is mediated through antagonism of M3 receptors and the decreased acetylcholine induced airway smooth muscle bronchoconstriction. Tiotropium is associated with increased lung function, health related quality of life, and exercise tolerance and reduced dyspnea and acute exacerbations of COPD (AECOPD). On November 19, 2009 the Pulmonary-Allergy Drugs Advisory Committee voted 11-1 for new product labeling about the benefits of tiotropium stating that the data provide “substantial and convincing evidence” that tiotropium decreases AECOPD. This indication “for reducing COPD exacerbations” was added to product labeling in December 2009. Tiotropium is safe and well tolerated with few side effects. The large multicenter UPLIFT (Understanding the Potential Long-Term Impacts on Function with Tiotropium) trial demonstrated the long-term safety of tiotropium over four years of continuous use showing no increase in stoke and all cause mortality. Serious adverse events including respiratory failure, congestive heart failure and myocardial infarction were significantly less in the tiotropium group. In a pre-specified subgroup analysis Tiotropium retarded FEV1 decline in milder COPD. Additional review of cholinergic pathobiology relevant to COPD and asthma provides context for future therapeutic and preventative roles for tiotropium.
Structural Identification of the Monomeric Constituents of Petroleum Pitch

The monomer fraction of a representative petroleum pitch, M-50, was characterized in terms of both the predominant polycyclic aromatic hydrocarbon (PAH) backbones and their extent of alkylation. Such an identification of individual molecular species and their relative abundance was greatly facilitated by the use of a series of separation processes prior to analysis. In particular, low (up to 270), medium (270−335), and high (335−388) molecular-weight cuts of the monomeric fraction of the M-50 pitch were isolated by dense-gas extraction (DGE). The resultant three cuts were then further fractionated by preparative-scale gel permeation chromatography (prep-scale GPC) to obtain narrow molecular-weight fractions suitable for individual species identification by both matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry and reversed-phase high-performance liquid chromatography with photodiode array detection (HPLC/PDA). Results indicate that the monomer fraction consists of five d...
Prediction of a shape-induced enhancement in the hole relaxation in nanocrystals

We present a pseudopotential calculation of the single particle and excitonic spectrum of CdSe nanocrystals. We find that in the excitonic manifold derived from the ground state electron and the first 60 hole states there are two energy gaps much larger than the typical LO phonon energy in bulk CdSe. Such gaps can effectively slow the hole relaxation process, as recently found experimentally. We show that they originate from two gaps in the hole spectrum and are therefore a single-particle effect, as opposed to an excitonic effect. The calculated width of the gaps increases with decreasing dot size, in agreement with the experimental trend of the energy loss rate that decreases with dot size. We find that the presence of the gaps is not limited to CdSe nanocrystals with the wurtzite crystal structure but is also found in spherical InAs zinc blende dots. Comparison with our results for quantum rods and cylinders of different aspect ratios, and with a single-band effective mass model, shows the origin of th...
Coaxial imaging technique for superior hypogastric plexus block.

Abstract Background and Objectives: Previously described techniques for superior hypogastric plexus (SHP) block are technically difficult. A simple coaxial imaging technique for SHP block is described. Methods and Results: Fluoroscopic guidance for coaxial approach to SHP block is described. A successful block is easily achieved. Conclusions: A new approach to SHP block is described, which is technically effective. Other approaches involve more difficult needle angulations or use of computed tomography guidance. The coaxial technique avoids these issues and is easy to perform. Reg Anesth Pain Med 2000;25:643-647.
PET/SPECT Imaging of Hindlimb Ischemia: Focusing on Angiogenesis and Blood Flow

Peripheral artery disease (PAD) is a result of the atherosclerotic narrowing of blood vessels to the extremities, and the subsequent tissue ischemia can lead to the up-regulation of angiogenic growth factors and formation of new vessels as a recovery mechanism. Such formation of new vessels can be evaluated with various non-invasive molecular imaging techniques, where serial images from the same subjects can be obtained to allow the documentation of disease progression and therapeutic response. The most commonly used animal model for preclinical studies of PAD is the murine hindlimb ischemia model, and a number of radiotracers have been investigated for positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging of PAD. In this review article, we summarize the PET/SPECT tracers that have been tested in the murine hindlimb ischemia model as well as those used clinically to assess the extremity blood flow.
Incontinence after prostatectomy: coping with incontinence after prostate cancer surgery.

Purpose/objectives To describe the nature of postprostatectomy urinary incontinence, determine how men manage postsurgery urinary incontinence, identify men's perceptions of adequacy of preoperative counseling, and identify men's expectations regarding the probability of postsurgery incontinence. Design Survey. Setting United States. Sample Members of US TOO International, who experienced urinary incontinence after surgery. Methods Copies of the survey (N = 370) were mailed to all chapters of US TOO International, a prostate cancer support group, for distribution to members. A letter of invitation also was posted on the US TOO International Web site and in the monthly newsletter. Men who desired to complete the survey (N = 130) called the researcher's office, and a copy of the survey and a stamped return envelope was mailed to them. Surveys returned to the researchers from June 1998 to January 1999 were included in the analyses. Main research variables Urinary incontinence, management of urinary incontinence, and coping. Findings 166 men returned surveys. The majority was Caucasian (95%) and married (83%). The median age was 67 years, 87% of the men rated their health as good or excellent, and 114 men (69%) reported becoming incontinent after surgery. Most men experienced stress incontinence symptoms. The majority (89 of 111 men) reported that they were told preoperatively that urinary incontinence was a possible complication. Overall, regardless of length of time since surgery, men (74%) thought that incontinence was an important problem to resolve. Men used containment devices such as pads, special undergarments, and even sanitary napkins as management strategies. The majority of men (54%) used pelvic muscle exercises, especially those who were fewer than two years postsurgery (72%). Conclusions Urinary incontinence is a prevalent postoperative complication for men, even up to five years after surgery, and a source of great distress for some. Men reported stress and urge incontinence symptoms and used an array of strategies to contain their urine. Finding effective treatments for postprostatectomy urinary incontinence and receiving adequate information before surgery is important to these men. Implications for nursing As the number of men who undergo surgical treatment for prostate cancer increases, nurses need to be equipped with the necessary knowledge and information to answer preoperative concerns and provide effective strategies for managing postoperative urinary incontinence.
Transform coding of stereo image residuals

Stereo image compression is of growing interest because of new display technologies and the needs of telepresence systems. Compared to monoscopic image compression, stereo image compression has received much less attention. A variety of algorithms have appeared in the literature that make use of the cross-view redundancy in the stereo pair. Many of these use the framework of disparity-compensated residual coding, but concentrate on the disparity compensation process rather than the post compensation coding process. This paper studies specialized coding methods for the residual image produced by disparity compensation. The algorithms make use of theoretically expected and experimentally observed characteristics of the disparity-compensated stereo residual to select transforms and quantization methods. Performance is evaluated on mean squared error (MSE) and a stereo-unique metric based on image registration. Exploiting the directional characteristics in a discrete cosine transform (DCT) framework provides its best performance below 0.75 b/pixel for 8-b gray-scale imagery and below 2 b/pixel for 24-b color imagery, In the wavelet algorithm, roughly a 50% reduction in bit rate is possible by encoding only the vertical channel, where much of the stereo information is contained. The proposed algorithms do not incur substantial computational burden beyond that needed for any disparity-compensated residual algorithm.
Mounting evidence against the role of ICC in neurotransmission to smooth muscle in the gut

How nerves transmit their signals to regulate activity of smooth muscle is of fundamental importance to autonomic and enteric physiology, clinical medicine, and therapeutics. A traditional view of ...