cssi/SciSciGPT-SciSciNet huggingface dataset:
Low Energy Theory for STM Imaging of Carbon Nanotubes

Scanning tunneling images of carbon nanotubes frequently show electron distributions which break the local sixfold symmetry of the graphene sheet. We present a theory of these images which relates the anisotropies to off diagonal correlations in the single particle density matrix induced by elastic scattering from tube defects. The theory reveals that there are three general effects which one can associate with elastic scattering from defects. Any defect can be characterized by a matrix of reflection coefficients which define its signature in the tunneling image. We provide a theory for tunneling images with broken translational symmetry, “primitive” broken symmetry images with broken rotational symmetry but no broken translational symmetry, and a novel “semiconductor effect” in which the symmetry of the tunneling image switches with the sign of the tunnel bias.
Combined Treatment with Morphine and Δ9-Tetrahydrocannibinol (THC) in Rhesus Monkeys: Antinociceptive Tolerance and Withdrawal

Opioid receptor agonists are effective for treating pain; however, tolerance and dependence can develop with repeated treatment. Combining opioids with cannabinoids can enhance their analgesic potency, although it is less clear whether combined treatment alters opioid tolerance and dependence. In this study, 4 monkeys received 3.2 mg/kg morphine alone or in combination with 1 mg/kg THC; the antinociceptive effects (warm water tail withdrawal) of morphine and the cannabinoid receptor agonists WIN 55212 and CP 55940 were determined before and during treatment. To determine whether this treatment produced dependence, behavioral signs indicative of withdrawal were monitored when treatment was discontinued. Before treatment, morphine and the cannabinoids, given alone, increased tail withdrawal latency to 20 sec (maximum possible effect). During treatment, latencies did not exceed 10 sec for any drug, up to doses 3- to 10-fold larger than those that were fully effective before treatment. Rightward and downward ...
Rapid formation and selective stabilization of synapses for enduring motor memories

Long-term memories for motor skill tasks are associated with enhanced synaptic efficacy in the motor cortex. Here, rapid structural responses in individual neurons are revealed to potentially underlie motor learning skill retention. In experiments in which mice were trained to perform a reaching task, new neuronal spines were selectively stabilized within hours, with different spines/putative synapse sets encoding distinct learned motor skills. These stabilized morphological changes are proposed to act as a motor memory substrate. The learning of novel motor skills through repetitive practice is associated with enhanced synaptic efficacy in the motor cortex. However, how motor learning affects neuronal circuitry at the level of individual synapses and how long-lasting memory is structurally encoded in the intact brain remain unknown. Synaptic connections in the living mouse brain are now shown to respond to motor-skill learning and permanently rewire; this could be the foundation of durable motor memory. Novel motor skills are learned through repetitive practice and, once acquired, persist long after training stops1,2. Earlier studies have shown that such learning induces an increase in the efficacy of synapses in the primary motor cortex, the persistence of which is associated with retention of the task3,4,5. However, how motor learning affects neuronal circuitry at the level of individual synapses and how long-lasting memory is structurally encoded in the intact brain remain unknown. Here we show that synaptic connections in the living mouse brain rapidly respond to motor-skill learning and permanently rewire. Training in a forelimb reaching task leads to rapid (within an hour) formation of postsynaptic dendritic spines on the output pyramidal neurons in the contralateral motor cortex. Although selective elimination of spines that existed before training gradually returns the overall spine density back to the original level, the new spines induced during learning are preferentially stabilized during subsequent training and endure long after training stops. Furthermore, we show that different motor skills are encoded by different sets of synapses. Practice of novel, but not previously learned, tasks further promotes dendritic spine formation in adulthood. Our findings reveal that rapid, but long-lasting, synaptic reorganization is closely associated with motor learning. The data also suggest that stabilized neuronal connections are the foundation of durable motor memory.
Silicon Oxide Micromodule Capacitors

Silicon oxide capacitors have been developed on micromodule wafers (O. 3lO-in. sq. with three termination notches per side). Each microelement contains 1, 2, 3, or 4 capacitors with values of 1120 and 560, 180, 100 and 68 pf per capacitor, respectively. The 1120 pf capacitor is double layered. In addition to the general requirements of microelements and micromodules, some of the more important specifications these capacitors must meet are: dissipation factor (DF) not exceeding 0.015, insulation resistance (IR) at 50 volts exceeding 10,000 megohms (25°C) and 750 megohms (125°c), 50 WVDC and 150 volts dielectric withstanding voltage (DWV), \Delta not exceeding + 15% (-55° to 125°C), no breakdown during or after a short term life test of 72 hours at 125°C while stressed at 150 volts, and a long term life test of 2000 hours at 125°C and 100 volts after which DF should not exceed 0.03 and IR should exceed 3000 megohms (room temperature) and be not less than 500 megohms (125°C). The capacitors are non-polar with vacuum deposited A1 electrodes and silicon oxide (largely monoxide) dielectric. They are fabricated in a microcircuit jig that processes 32 microelements simultaneously and 192 microelements during one vacuum cycle. Both the A1 and SiO are deposited at the monitored and controlled rate of 50 A/sec. The thicknesses of electrodes and dielectric are 5000 and 12,500, respectively. Wafer temperature during deposition is about 170°C and chamber pressure is 1-4x10-5torr during A1 evaporation, and 0.6-1x10-5 torr during SiO evaporation. The SiO evaporator design is important; a baffled Ta box has proven satisfactory. Deposition masks were made from 0. 005-in. spring steel by photoresist techniques. Capacitors deposited on unglazed alumina wafers had DF readings of approximately 0.3; undercoating with SiO or polishing the wafers did not prove effective in reducing the DF appreciably. Glazing' the alumina prior to capacitor deposition lowered the DF to about 0.04. Two approaches to glazed elements were equally successful: (1) a glass frit fired onto an unglazed, metallized wafer; (2.) metallizing applied to a glazed wafer. The second approach has been adopted. Capacitance is uniform to within ±5% and DF to within ± 10%. It was found that heat treatment in air at 250°C for at least 48 hours lowered the DE to less than 0.008, lowered the capacitance by about 10%, and increased IR to over 10,000 megohms without causing detrimental electrode-land reactions. Presumably, oxygen diffuses into the dielectric converting it to SiOx(1< x <2) and lowering its dielectric constant. The units are very stable, maintaining their capacitance, DF, and DWV values for months while stored at 25°C in ambient atmosphere. **
Photon path distributions in turbid media: Applications for imaging

Near-IR optical tomography is thwarted by the highly scattering nature of light propagation in tissue. We propose a weighted back-projection method to produce a spatial map of an optical parameter which characterized the investigated medium. We have studied the problem of the choice of the back-projection weight function for the absorption coefficient ((mu) a) and for the reduced scattering coefficient ((mu) s') of tissuelike phantoms. Working in frequency-domain optical imaging, we have initially approached the problem of quantifying the effect caused by a small absorbing defect embedded in the medium on the measured DC intensity, AC amplitude, and phase. The collection of DC, AC, and phase changes during a 1 mm step raster scan of the absorbing defect provides information on the photon path distributions and, in general, on the probed spatial region when DC, AC, and phase are, respectively, the measured parameters. We report experimentally determined weight functions for (mu) a and (mu) s'. They indicate that absorption and scattering maps can significantly differ in terms of resolution.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Factors affecting evidence-based decision making in local health departments.

Background Data indicating the extent to which evidence-based decision making (EBDM) is used in local health departments (LHDs) are limited. Purpose This study aims to determine use of decision-making processes by New York State LHD leaders and upper-level staff and identify facilitators and barriers to the use of EBDM in LHDs. Methods The New York Public Health Practice-Based Research Network implemented a mixed-methods study in 31 LHDs. There were 20 individual interviews; five small-group interviews (two or three participants each); and two focus groups (eight participants each) conducted with people who had decision-making authority. Information was obtained about each person’s background and position, decision-making responsibilities, how decisions are made within their LHD, knowledge and experience with EBDM, use of each step of the EBDM process, and barriers and facilitators to EBDM implementation. Data were collected from June to November 2010 and analyzed in 2011. Results Overall, participants supported EBDM and expressed a desire to increase their department’s use of it. Although most people understood the concept, a relatively small number had substantial expertise and experience with its practice. Many indicated that they applied EBDM unevenly. Factors associated with use of EBDM included strong leadership; workforce capacity (number and skills); resources; funding and program mandates; political support; and access to data and program models suitable to community conditions. Conclusions EBDM is used inconsistently in LHDs in New York. Despite knowledge and interest among LHD leadership, the LHD capacity, resources, appropriate programming, and other issues serve as impediments to EBDM and optimal implementation of evidence-based strategies.
On the capabilities and limitations of GCCM simulations of summertime regional air quality: A diagnostic analysis of ozone and temperature simulations in the US using CESM CAM-Chem

Abstract We conduct a diagnostic analysis of ozone chemistry simulated by four different configurations of a Global Climate-Chemistry Model (GCCM), the Community Earth System Model (CESM) with detailed tropospheric chemistry. The purpose of this study is to evaluate the ability of GCCMs to simulate future ozone chemistry by evaluating their ability to simulate present-day chemistry. To address this we chose four configurations of the CESM that differ in their meteorology (analyzed versus simulated meteorological fields), number of vertical levels, and the coupling of the ice and ocean models. We apply mixed model statistics to evaluate these different configurations against CASTNET ozone observations within different regions of the US by using various performance metrics relevant to evaluating future ozone changes. These include: mean biases and interannual variability, the ozone response to emission changes, the ozone response to temperature changes and ozone extreme values. Using these metrics, we find that although the configuration using analyzed meteorology best simulates temperatures it does not outperform a configuration with simulated meteorology in other metrics. All configurations are unable to capture observed ozone decreases and the ozone north-south gradient over the eastern US during 1995–2005. We find that the configuration with simulated meteorology with 56 vertical levels is markedly better in capturing observed ozone-temperature relationships and extreme values than a configuration that is identical except that it contains 26 vertical levels. We recommend caution in the use of GCCMs in simulating surface chemistry as differences in a variety of model parameters have a significant impact on the resulting chemical and climate variables. Isoprene emissions depend strongly on surface temperature and the resulting ozone chemistry is dependent on isoprene emissions but also on cloud cover, photolysis, the number of vertical levels, and the choice of meteorology. These dependencies must be accounted for in the interpretation of GCCM results.
Formation of the mutagen IFP in model systems and detection in restaurant meats.

Mixtures of the free amino acids, creatine and glucose, were dry-heated to model the potential formation of heterocyclic amines in meats. The formation of the mutagenic amine IFP (determined to be ...
Order in two dimensions

Abstract Recent developments in the study of phase transitions in surface layers and overlayers are reviewed. In particular we outline the universality classes accessible in surface experiments and discuss types of order which can occur in 2D systems. We also discuss the effects of various types of disorder inherent in real substrates and phase transitions of the substrate itself on both ordering properties and critical behavior. The current status of critical phenomena studies in chemisorbed layers is discussed.
Carbamazepine-induced systemic lupus erythematosus presenting as cardiac tamponade

Here we report the case of a patient who presented with acute cardiac tamponade due to drug-induced systemic lupus erythematosus (SLE). The patient had been treated for a seizure disorder with carbamazepine, a drug that has previously been demonstrated to cause SLE-like syndromes. Further serologic analysis demonstrated the likelihood of drug-induced SLE in this patient, with the rare presentation of cardiac tamponade.
Medicine and Public Health: Pursuing a Common Destiny

MEDICINE and public health in the United States are drawing together to work for the good of health and health care through a new movement: the Medicine/Public Health Initiative. The irony of the split and the importance of the bonding come home in the comment a longtime member of the American Medical Association (AMA) made in a conversation with me on informing the general public about the Initiative: "You know," he said, "what will surprise the public is not the news that we are coming together, but the fact that for so long we have been working apart." This separation was not the way of practice envisioned by the founders of Western medicine—Hippocrates and his disciples. "Airs, Waters, Places," one of the most important treatises in the Hippocratic corpus, begins: Whoever wishes to pursue properly the science of medicine must proceed thus: First he ought to consider what effects each
Concurrency and availability as dual properties of replicated atomic data

A replicated data object is a typed object that is stored redundantly at multiple locations in a distributed system. Each of the object's operations has a set of quorums, which are sets of sites whose cooperation is needed to execute that operation. A quorum assignment associates each operation with its set of quorums. An operation's quorums determine its availability, and the constraints governing an object's quorum assignments determine the range of availability properties realizable by replication.In this paper, the restrictions on quorum assignment imposed by three kinds of atomicity mechanisms found in the literature are analyzed: (1) serial schemes, in which replication and atomicity are implemented independently at different levels in the system, (2) static schemes, in which the transaction serialization order is predetermined, and (3) hybrid schemes in which the serialization order emerges dynamically.The following results are derived: (1) Although serial schemes place the strongest restrictions on concurrency, they place the weakest restrictions on availability. (2) Although hybrid and static mechanisms place incomparable restrictions on concurrency, hybrid mechanisms place weaker restrictions on availability. (3) Bounding the maximum depth of transaction nesting strengthens restrictions on concurrency for all classes, but weakens restrictions on availability for hybrid schemes only. Concurrency and availability are best considered as dual properties: A complete analysis of an atomicity mechanism should take both into account.
Dose-dependent protein binding and disposition of prednisolone in rabbits.

An animal model was sought that would mimic humans with regard to the dose-dependent pharmacokinetics of prednisolone. Four rabbits were each given 0.5 and 10 mg iv of prednisolone, and timed blood samples were obtained. Plasma prednisolone and prednisone concentrations were assayed by high-performance liquid chromatography, and protein binding was assessed using equilibrium dialysis at 37°. Increases in the systemic clearance, volume of distribution at steady state, mean residence time (in three of four rabbits), and variance of residence time occurred as dose was increased. As in humans, prednisolone was partly converted to prednisone in the rabbit. Transcortin and albumin concentrations and their affinity constants for binding prednisolone were also similar to humans.
Metal nanoslit lenses with polarization-selective design: erratum

A part of the sentence just before Eq. (1) in our previous Letter [Opt. Lett. 36, 451 (2011)] was incorrect and is corrected here.
INTERACTIONS BETWEEN FIRE AND SPRUCE BEETLES IN A SUBALPINE ROCKY MOUNTAIN FOREST LANDSCAPE

Interactions between natural disturbances are widely recognized as important determinants of vegetation patterns in forested landscapes but have only rarely been in- vestigated quantitatively. In a subalpine forest landscape in northwestern Colorado, we quantified spatial associations of fire and spruce beetle ( rufipennis ) outbreaks over more than a century and developed a multivariate logistic model of probability of occurrence of spruce beetle outbreaks. The study area, an ;2800 km 2 landscape in White River National Forest, was affected by severe widespread fires around 1879 and by a spruce beetle outbreak in the 1940s, which affected most of the forests that were dominated by Picea engelmannii(Engelmann spruce) and Abies lasiocarpa(subalpine fir). The boundaries of the fires ca. 1879 and of the 1940s spruce beetle outbreaks were digitized based on an 1898 vegetation map and modern aerial photograph interpretation, and overlaid in a Geo- graphic Information System. The areas disturbed by the ca. 1879 fires and the 1940s beetle outbreak were also overlaid with 303 fires recorded after 1950 as well as with topographic and forest structural variables. Forests that had burned in 1879 were less affected by the 1940s outbreak than older stands. On the other hand, areas affected by the 1940s spruce beetle outbreak showed no higher susceptibility to subsequent fires. A multivariate logistic model indicated that, al- though fire history had the greatest effect on stand susceptibility to spruce beetle outbreak, dominance of neighboring stands by spruce as well as elevation were also important pre- dictors of outbreaks. Predictive modeling of spatial interactions between fire and spruce beetle disturbances needs to consider the high degree of variability in the nature of these interactions related to contingencies such as time since last major disturbance, topographic position, and weather during windows of potential interaction.
Bismuth based layered perovskite thin films as a charge storage material for low power nonvolatile gaas memory applications

Abstract This work details initial process development and integration of ferroelectric SrBi2Ta2O9 and SrBi2Ta2(1-x)Nb2xO9 for use in low power nonvolatile GaAs memory technology. A spin on process is used to deposit the ferroelectric thin films. Capacitance, hysteresis loop, and switched charge versus time data are presented for metal-ferroelectric-metal capacitors using platinum as the electrode material. Indications are that the substitution of niobium for tantalum in the layered perovskite structure increases both the non-volatile polarization and the coercive field of the material. N-channel transistor characteristics of the low power gallium arsenide field effect transistor contained in the 1T-1C memory bit are also presented. The results presented here imply that these materials warrant further research and process integration studies to realize low power non-volatile GaAs memory technology.
Systemic delivery of therapeutic peptides and proteins

Abstract Peptide/protein drugs are increasingly becoming a very important class of therapeutical agents as a result of our gaining more understanding of their role in physiology and pathology as well as the rapid advances in the field of biotechnology/genetic engineering. These drugs are easily degraded by proteolytic enzymes in the gastrointestinal tract and thus are generally not suitable for oral administration. Currently, they are mostly delivered by parenteral administration. Because they are extremely short-acting, repeated injections are often required. To minimize the health hazard by constant injection, there is an urgent need to search for non-parenteral routes of administration as well as to develop formulations with controlled delivery features. Routes of administration that have been investigated include nasal, ocular, rectal, buccal and transdermal. The mode of delivery can also be very important. In the case of luteinizing hormone-releasing hormone analogs, opposite pharmacological effects could be observed depending on whether they are delivered in a pulsatile pattern or in a continuous manner. Self-regulating systems which will release drug based on the needs of the body (feedback mechanism) have also been developed for some peptide/protein drugs, like insulin. Special considerations are required for the formulation, pharmacokinetic and analytical aspects of peptide/protein drugs. Further work is needed on these aspects and on the routes of administration for commercial viability of therapeutic peptides/proteins.
CLINICAL ASPECTS OF APLASTIC ANEMIA

Severe aplastic anemia is a disorder characterized by peripheral pancytopenia and marrow hypoplasia. Although its pathophysiology is understood poorly, the majority of patients appear to have some immunologic destruction or suppression of hematopoietic cells. The only curative therapy to date is allogeneic stem cell transplantation, although the success of palliative immunosuppressive therapies has improved over the last two decades. Making the best therapy choice is complex and often requires balancing very divergent toxicity profiles, both acute and long-term.
International students in United States’ medical schools: does the medical community know they exist?

Background: Matriculation of international students to United States’ (US) medical schools has not mirrored the remarkable influx of these students to other US institutions of higher education. Methods: While these students’ numbers are on the rise, the visibility for their unique issues remains largely ignored in the medical literature. Results: These students are disadvantaged in the medical school admissions process due to financial and immigration-related concerns, and academic standards for admittance also continue to be significantly higher compared with their US-citizen peers. Furthermore, it is simply beyond the mission of many medical schools both public and private to support international students’ education, especially since federal, state-allocated or institutional funds are limited and these institutions have a commitment to fulfill the healthcare education needs of qualified domestic candidates. In spite of these obstacles, a select group of international students do gain admission to US medical schools and, upon graduation, are credentialed equally as their US-citizen counterparts by the Accreditation Council for Graduate Medical Education (ACGME). However, owing to their foreign citizenship, these students have visa requirements for post-graduate training that may adversely impact their candidacy for residency placement. Conclusion: By raising such issues, this article aims to increase the awareness of considerations pertinent to this unique population of medical students. The argument is also made to support continued recruitment of international students to US medical schools in spite of these impediments. In our experience, these students are not only qualified to tackle the rigors of a US medical education, but also enrich the cultural diversity of the medical student body. Moreover, these graduates could effectively complement the efforts to augment US physician workforce diversity while contributing to healthcare disparity eradication, minority health issues, and service in medically underserved areas. Keywords: international students; medical school admission; diversity; minority; recruitment (Published: 4 June 2012) Citation: Med Educ Online 2012, 17 : 15748 - http://dx.doi.org/10.3402/meo.v17i0.15748
Gray matter T2 hypointensity is related to plaques and atrophy in the brains of multiple sclerosis patients

Cortical and subcortical gray matter hypointensities on T2-weighted MR images (T2WI) occur commonly in MS brains and have been related to disease duration, clinical course, and the level of neurologic disability. These hypointensities have been reported to occur in the thalamus, basal ganglia, and rolandic cortex. We assessed whether T2 hypointensity is associated with the severity of white matter plaques and atrophy of MS brains. In 114 MS patients, hypointensity of the thalamus, putamen, caudate, and sensorimotor cortex was ordinally rated against age- and gender-matched normal controls on 1.5-T MRI fast spin-echo axial T2WI. Regional and global T2 hyperintense and T1 hypointense parenchymal lesion loads were ordinally rated. Enlargement of subarachnoid and ventricular spaces (atrophy) was ordinally rated vs. age- and gender-matched normal controls. T2 hypointensity was highly, positively correlated with many other MRI variables. Regression modeling showed that T2 hypointensity was related to total atrophy, total T2 lesion load, third ventricular enlargement, parietal atrophy, and to a lesser extent, frontal T1 lesions and cerebellar T2 lesions, but not related to gadolinium enhancement. Ordinal ratings of T2 lesions and central atrophy showed high correlations with quantitative computerized assessments. We conclude that gray matter hypointensity on T2WI may reflect pathologic iron deposition and brain degeneration in MS. This T2 hypointensity is associated with brain atrophy and other MR markers of tissue damage. Further study is warranted to determine if T2 hypointensity is predictive of disease course in MS and is a useful surrogate outcome measure in therapeutic trials.
Microcomputer versus mainframe usage by marketing professionals

The purpose of this research is to measure the extent of usage of microcomputers, compared to mainframe usage, by marketing professionals and to describe how microcomputers are used as an aid in marketing decision-making. A national sample of marketing professionals responded to a questionnaire concerning availability of microcomputers and mainframes, decisions and responsibilities performed with each type of computer, software and hardware used, and selected demographics. The results document considerable diffusion of hardware technology as well as widespread use and satisfaction with available software in the subset responding.
SU-D-12A-04: Investigation of a 2D Antiscatter Grid for Flat Panel Detectors

Purpose: To improve CT number accuracy and contrast sensitivity, a novel 2D antiscatter grid (ASG) for flat panel detector (FPD) based CBCT imaging was evaluated. Experiments were performed to characterize the scatter rejection and contrast sensitivity performance of ASG. The reduction in primary transmission for various ASG geometries was also evaluated by a computational model. Methods: The 2D ASG design was based on multi-hole collimators used in Nuclear Medicine. It consisted of abutted hexagon shaped apertures with 2.5 mm pitch and 32 mm height, and separated by 0.25 mm thick lead septa. Scatter-to-primary ratio (SPR), contrast-to-noise ratio (CNR), and mean primary transmission were measured using a benchtop FPD/x-ray source system. Acrylic slabs of varying thicknesses were imaged with a contrast-detail phantom to measure CNR and SPR under different scatter conditions. Primary transmission was also measured by averaging pixel values in flood field images without the phantom. We additionally explored variation of primary transmission with pitch and septum thickness using a computational model of our ASG. Results: Our 2D ASG reduced the SPR from 3.3 to 0.12, and improved CNR by 50% in 20 cm thick slab phantom projections acquired at 120 kVp. While the measured primary transmission was 72.8%, our simulations show that primary transmission can be increased to 86% by reducing the septum thickness to 0.1 mm. Primary transmission further increases to 93% if septum thickness of 0.1 mm is used in conjunction with an increased pitch of 4 mm. Conclusion: The 2D ASG appears to be a promising scatter rejection device, offering both superior scatter rejection and improved contrast sensitivity. Though its lead footprint reduced primary transmission, our work shows that optimization of aperture pitch and septum thickness can significantly improve the primary transmission.
Illuminating Mitochondrial Function and Dysfunction using Multiphoton Technology

Studying differential cell function or dysfunction within the kidney is made difficult by cellular heterogeneity, alterations in regional blood flow, oxygen tension, and interstitial tonicity, resulting in extremely complex anatomic and physiologic arrangements. Creative investigators have developed techniques to reduce this heterogeneity but often with loss or alteration of three-dimensional cellular associations, anatomic and physiologic cell-to-cell interactions, and harsh isolation and experimental conditions. These limitations have made “absolutes” difficult to determine, especially in relation to pathologic processes such as cell type involvement in renal ischemia. In this issue of JASN , Hall et al. 1 use multiphoton microscopy of kidney slices to compare mitochondrial parameters and differential cellular responses to stress. This approach allows them to quantify several key parameters of mitochondrial function and dysfunction in proximal tubular (PT) cells and directly compare different PT segments with each other and with distal tubular (DT) cells of the thick ascending limb (TAL). Because mitochondrial alterations play a central role in normal cell function and in response to injury, the article adds to our previous knowledge about an important area. To understand the significance and limitations of their contribution, one must first understand what is known about differences between PT and TAL cells. Abundant mitochondria in cortical and outer medullary renal epithelial cells are necessary to meet the ATP demands of sodium transport by high-capacity aerobic metabolism. They compose 33% of the volume of proximal convoluted tubular S1 cells, 39% of the cells in the S2 segment, and 22% of the volume of cells in the proximal straight S3 segment; in the medullary and cortical TAL cells, mitochondria account for 30 to 44% of cell volume.2 Differential tubular cell metabolism is also notable for the absence of aerobic and anaerobic glycolysis in the proximal convoluted tubule (S1), …
Subterranean struggles: new dynamics of mining, oil and gas in Latin America

The scholarship of extractive industries is experiencing boom times. As extractive activity has expanded across the global south since the early 2000s, so too has the social science of the subsurfa...
Regional Structure in Sub-Saharan Africa

The urban hierarchies of 280 subnational regions of sub-Saharan Africa are shown to be systematically related to ecological and economic indicators all across Africa, despite that continent's cultural and ecological diversity. Using data from detailed maps of Africa, it appears that urban hierarchy, indexed by the number of cities with a population of 20,000 or more, correlates with the number of towns, the population of the largest place, the population of the region, density, the number of industries (both agricultural and general), and even ecological features like lakes, forests and dams. Additionally, and surprisingly, the number of different agricultural export crops in the region and the number of different minerals that are exploited correlate with the number of cities. Regression analysis of cities and towns within zones, defined by distance from the coast, clarifies the determinants of hierarchy levels.
The variation of the blocking temperature in models of thermoremanence (TRM)

Abstract The simplest non-interactive forms of Neel's domain-reversal and wall-motion models are examined and the variations of their respective blocking temperatures as functions of applied field and coercivity are compared. Both models show remarkably similar blocking temperature behavior, but the remanence acquisition mechanisms are so different as to produce diametrically opposed results when the Lowrie-Fuller stability criterion is considered. In particular, in low fields the wall-motion model selectively activates high-coercivity fractions while the domain-reversal model favors the low coercivities. This results in the paradox that the wall-motion model predicts behavior experimentally associated with the single-domain and pseudo-single-domain size range while the domain-reversal model predicts behavior usually associated with the large multidomain range. The paradox can be partly resolved within the multidomain model alone, but this would not apply for the smallest grain sizes. Several alternative approaches to the problems of this size range are suggested.
Clock buffer polarity assignment considering capacitive load

A clock buffer polarity assignment method is proposed that considers the impact of capacitive load on the peak current. It is shown that the peak current on the supply rails of a buffer is a monotonically increasing function of its driving capacitance. Consequently, the polarity of a clock buffer is assigned based on its capacitive load. The proposed method can be applied to assign buffer polarity on any number of levels of the clock tree. In experiments, the peak current on the clock tree in each local area is reduced by 36.3% on average. The worse case peak current of all the local areas are reduced by 35.7% on average. The proposed method is implemented with a pseudo-polynomial dynamic programming scheme demonstrating runtimes under a minute.
Changes in immediate visual memory predict cognitive impairment

Six-year changes in immediate visual memory performance assessed by the Benton Visual Retention (BVR) test predicted Alzheimer's disease (AD) prior to its onset. Subjects of this study were 371 community-dwelling adult participants in the Baltimore Longitudinal Study of Aging, seven of whom received probable or definite AD diagnoses using DSM-III-R and NINCDS-ADRDA criteria. Subjects with diagnoses of AD had larger changes in immediate memory performance over the 6-year interval prior to the estimated onset of their disease than subjects without AD. Six-year longitudinal change as well as level in immediate visual memory performance also predicted subsequent cognitive performance 6-15 and 16-22 years later, even after adjusting for the influences of age, general ability, and initial immediate memory. These results provide evidence that change and level in immediate visual memory performance has long-term prognostic significance over as many as 16-22 years. These results further suggest that change in recent memory performance, an important component in AD diagnoses, may be an important precursor of the development of the disease.
Gliadins polymerized with cysteine: effects on the physical and water barrier properties of derived films.

To study the effects of disulfide bonds on certain functional properties of films made from the wheat gluten proteins gliadin and glutenin, cysteine was used to promote the formation of interchain disulfide bridges between gliadins in 70% ethanolic solution. Disulfide-mediated polymerization of gliadins was confirmed by means of SDS−PAGE analysis. After chemical treatment of gliadins, films were solution cast and the effects of both glycerol (used as a plasticizer) and relative humidity were studied on water vapor permeability, moisture sorption isotherms at 23 °C, and the optical properties of the films. The results were compared with those obtained from analogous films made from untreated glutenin macromolecules. Cysteine-mediated polymerization of gliadins improved the water vapor resistance of films achieving values close to those obtained for glutenin films. Development of intra- and interchain disulfide bonds did not change the moisture sorption capacity of the films but transparency was slightly di...
Does spontaneous ventilation with IMV protect from PEEP-induced cardiac output depression?

Abstract The hemodynamic effects of 20 cm H 2 O positive end-expiratory pressure (PEEP) administered with controlled mechanical ventilation (CMV) were compared to 20 cm H 2 O PEEP administered with spontaneous ventilation and intermittent mandatory ventilation (1MV) in the same group of six normovolemic baboons. Both CMV and IMV caused cardiac output to fall and intrathoracic and intravascular pressures to rise. Pulmonary vascular resistance increased and the intrathoracic vena cava was compressed with both modes of administering PEEP. The degree of cardiac output depression in each animal and in each group was the same. PEEP administered with spontaneous ventilation with IMV offers no significant protection over controlled ventilation in normal baboons.
Laser speckle contrast imaging of flow in a microfluidic device

ABSTRACT Laser speckle contrast imaging (LSCI) is a well established technique for imaging blood flow in the brain. Microfluidic devices were designed and fabricated in PDMS and TiO 2 to mimic the capillary network in the brain, with different channel sizes (10microns to 150microns). The flow of intralipid through the channels was imaged with LSCI. The microfluidic devices were used as a tissu e phantom to perform controlled experiments to investigate the effect of factors that influence speckle contrast like speed, concentration of intralipid, depth of channels and exposure time. A speckle imaging instrument that allows image acq uisition over a wide range of exposure times is presented. Speckle contrast was found to be a function of speed and exposure time, with concentration and channel depth serving to improve signal strength. Exposure time is shown to influence the sensitivity of speckle contrast to speed. It is also shown that speckle contrast as a function of exposure time can potentially be used a method to obtain qualitative measurements of speed. Keywords: Laser Speckle Contrast Imaging, microfluidics, Dynamic Light Scattering, speckle velocimetry, exposure modulation.
On-the-Fly Principled Speculation for FSM Parallelization

Finite State Machine (FSM) is the backbone of an important class of applications in many domains. Its parallelization has been extremely difficult due to inherent strong dependences in the computation. Recently, principled speculation shows good promise to solve the problem. However, the reliance on offline training makes the approach inconvenient to adopt and hard to apply to many practical FSM applications, which often deal with a large variety of inputs different from training inputs. This work presents an assembly of techniques that completely remove the needs for offline training. The techniques include a set of theoretical results on inherent properties of FSMs, and two newly designed dynamic optimizations for efficient FSM characterization. The new techniques, for the first time, make principle speculation applicable on the fly, and enables swift, automatic configuration of speculative parallelizations to best suit a given FSM and its current input. They eliminate the fundamental barrier for practical adoption of principle speculation for FSM parallelization. Experiments show that the new techniques give significantly higher speedups for some difficult FSM applications in the presence of input changes.
The relationship between the hydrogen and oxygen isotopes of freshwater bivalve shells and their home streams

AbstractRecent technical advances have facilitated the analysis of microgram-size samples of mollusk shell for the hydrogen isotopecomposition of the organic matrix. Our results suggest that these data are meaningful as the δD shell values of samples of freshwaterbivalve shells from different streams preserve the relative distribution of δD values from the water they inhabited over their lifetime(δD shell −δD water =−145‰) after correcting for the contribution of exchangeable hydrogen (∼36%) in organic matrix. WhenδD shell values are compared to the δ 18 O values of the mineral fraction of the shell (CaCO 3 as aragonite), they plot along a line thatreflects the isotopic composition of the waters in which the bivalves lived. This relationship is potentially useful forpaleoenvironmental reconstructions because the δD value of the organic matrix may serve as an independent proxy for the δ 18 Ovalue of water in paleotemperature equations.© 2006 Elsevier B.V. All rights reserved. Keywords: Stable isotopes; Continental environmental proxies; Unionid; Deuterium; Paleotemperature
Determination of charge transfer kinetic parameters using an automated flow system

Abstract The use of an automated flow system coupled to a mathematically rigorous fitting routine is described for determination of the charge transfer kinetic parameters for members of the 1,4-benzodiazepines. The automated flow system offers increased productivity and reproducibility which promote investigation of the model system under a variety of experimental conditions. The values of the charge transfer parameters for reduction of the adsorbed material were determined for a range of electrode surface coverage, supporting electrolyte, and stripping parameters. The interpretation is complicated by the artifact of IR drop, which affects the magnitude of the rate parameters but not the correspondence between the experimental and optimal theoretical voltammogram. The dependence of the charge transfer coefficient α on ionic strength indicated a supporting electrolyte concentration of 1.0 M to be a proper compromise between solution resistivity and solution impurities. Values of the charge transfer coefficient and the rate constant (in reciprocal seconds, referred to −0.6 V vs. SCE) for the totally irreversible reduction of adsorbate were determined for alprazolam (0.674 ± 0.005, −3.80 ± 0.04), loprazolam (0.695 ± 0.004, −5.42 ± 0.050), midazolam (0.721 ± 0.007, −2.74 ± 0.05), and triazolam (0.750 ± 0.005, −4.10 ± 0.05) respectively, in 1.0 M acetate buffer at 25°C.
Actions of cocaine on rat nucleus accumbens neurones in vitro

Abstract 1. Intracellular recordings were made from 103 neurones of the rat nucleus accumbens in vitro. 2. Dopamine (3-100 microM; in sulpiride, 1 microM) hyperpolarized neurones (79%) by acting at D1 receptors: dopamine (3-100 microM; in SCH23390, 1 microM) depolarized neurones (55%) by acting at D2 receptors. 5-Hydroxytryptamine (1-100 microM) depolarized 86% neurones. 3. Both actions of dopamine as well as the effect of 5-hydroxytryptamine were potentiated by cocaine (0.3-30 microM), which had no effect of its own on membrane potential. 4. Dose-ratio was computed as [(concentration of agonist causing a 4 mV potential change in cocaine)/(concentration of agonist causing a 4 mV potential change without cocaine)]. Cocaine (1-30 microM) caused the same dose-ratio whether dopamine depolarizations (D2) or hyperpolarizations (D1) were measured; the dose-ratio ranged from 2 (1 microM) to 50 (30 microM). 5. Responses to 5-hydroxytryptamine were increased more than responses to dopamine; cocaine 1 microM gave a dose-ratio of 13.4 and at 30 microM gave a dose-ratio of 118. 6. It is concluded that cocaine acts to inhibit the uptake of dopamine and 5-hydroxytryptamine in slices of rat nucleus accumbens; lower concentrations of cocaine (0.3 to 1 microM) are particularly effective in potentiating the action of 5-hydroxytryptamine.
Direct Response in Yield and Correlated Response in Components Accompanying Selection for Milk Yield in Jerseys

In 1967, the Jersey herd at the Dairy Experiment Station, Lewisburg, TN was divided into two groups on the basis of ancestry, type, and breeding value for milk as part of a project to determine effects of single trait selection for high milk yield on yield and correlated traits. Control group was mated randomly to 20 unproven young sires selected randomly from those available from breeding studs in 1967. Selection group was mated to sires selected solely on the basis of their high transmitting ability for milk. Selection sires were selected at intervals and used for 4 yr. By the end of the project (1984), lactation information was available on 672 daughters (520 selection and 152 control) of 37 bulls (17 selection and 20 control). Differences in breeding values for milk, fat, and fat test as calculated from the PTA reported in the July 1989 USDA genetic evaluations and differences in first lactation mature equivalent production of milk, fat, fat test, and 4% FCM were examined. Linear mixed models were used for all analyses and contained the fixed effects group, generation within group, and year. Sires were random, nested within group, and used to test for group differences. Groups differed for all traits. Selection was superior to control in breeding value for milk and fat (828 and 31 kg) and for production of milk, fat, and 4% FCM (1066, 42, and 1061 kg). Control was superior to selection in breeding value and production fat test (.15 and .12%). Group differences existed within generation class for all yield traits but not for fat percentage. Realized response closely matched or exceeded expected response as estimated from pedigree information.
The bile acid–activated phosphatidylinositol 3-kinase pathway inhibits Fas apoptosis upstream of bid in rodent hepatocytes

Abstract Backgrounds & Aims: Bile acids differentially modulate hepatocyte injury in cholestasis. Although glycochenodeoxycholate (GCDC) induces Fas-mediated hepatocyte apoptosis, taurochenodeoxycholate (TCDC) simultaneously activates a phosphatidylinositol 3-kinase (PI 3-K)-mediated survival pathway blocking Fas apoptosis. In this study, the mechanisms by which the TCDC/PI 3-K survival signal disrupts Fas signaling were examined. Methods: Studies were performed in primary cultures of mouse hepatocytes and the bile-salt–transporting McNtcp.24 rat hepatoma cell line. Results: GCDC, but not TCDC, resulted in cytochrome c release demonstrating that TCDC blocked apoptosis upstream of mitochondria. In contrast, both GCDC and TCDC treatment resulted in Fas aggregation and recruitment of a dominant-negative FADD green fluorescent protein (GFP) and C360S procaspase 8-GFP to the plasma membrane. Despite recruitment of procaspase 8 to the plasma membrane by both bile acids, only GCDC resulted in increases of caspase 8 activity and Bid-GFP mitochondrial translocation. However, when PI-3K was inhibited with wortmannin or dominant-negative PI 3-K, TCDC-induced Bid-GFP mitochondrial translocation and cytochrome c release. Conclusions: The TCDC/PI 3-K survival signal blocks Fas-mediated apoptosis by preventing caspase 8 activation and Bid mitochondrial translocation. Potentiation of this survival pathway in cholestasis has the potential to attenuate liver injury. GASTROENTEROLOGY 2001;120:1810-1817