cssi/SciSciGPT-SciSciNet huggingface dataset:
Valence Discrimination Effects with Thermospray Sample Introduction: Characterization and Prevention:

With thermospray sample introduction for atomic spectrometry, sensitivity for certain elements can be valence-dependent (valence discrimination effect). To this point, this effect appears to be significant only for nonmetals with easily reducible lower oxidation states, such as arsenic, antimony, and selenium. In this work, the valence discrimination effects for these elements were studied in detail with inductively coupled plasma atomic emission spectrometry detection. The sensitivities for As(III), Sb(III), and Se(IV) were found to be significantly lower than those for As(V), Sb(V), and Se(VI), respectively. In general, the sensitivity difference between the low- and high-valence species increases with thermospray temperature but decreases with an increase in HCl or HNO concen3 tration in solution. The low sensitivity for the low-valence species proved to arise from their reduction to corresponding metals within the thermospray process, after which the metals were trapped on the vaporizer and desolvation system. An effective way to prevent the valence discrimination effect is by means of the addition of a suitable oxidant into the solution.
Transpleural complications of liver biopsy.

Excerpt To the editor: Since submitting my manuscript on unilateral edema (1), I have encountered a cirrhotic patient with ascites who developed unilateral right-sided edema after a liver biopsy. T...
The serum transaminase test in various diseases. Its diagnostic value in liver disease

Abstract 1. 1. The results of serum glutamic-oxalacetic transaminase (SGO-T) tests in 111 patients with a wide variety of disease states is reported. 2. 2. No elevations of SGO-T were found in patients with mild benign idiopathic pericarditis, uncomplicated congestive heart failure, various forms of congenital and acquired heart disease, 2 cases of pulmonary infarction, chronic pancreatitis, quiescent nonlctsric cirrhosis of the liver, congenital hemolytic jaundice, various forms of cancer, cerebral vascular accidents, pneumonia, subphrenic abscess, chronic nephritis, dissecting aneurysm, diabetes, dermatomyositis, 50 per cent of postoperative patients, and 4 out of 5 newborn infants. 3. 3. Slight elevations of SGO-T were found in rheumatic pericarditis, pulmonary infarctions with and without congestive heart failure, quiescent nonicteric cirrhosis of the liver, chronic lymphatic leukemia, one cerebral vascular accident, scleroderma, shock, diverticulitis of the colon, probable renal infarction, some postoperative patients, and 1 newborn infant. 4. 4. Marked elevationsof SGO-T were found in severe idiopathic pericarditis, preterminal shock and cyanosis, acute pancreatitis, viral hepatitis, obstructive jaundice, cirrhosis of the liver with jaundice, metastatic cancer of the liver, muscular dystrophy, paroxysmal myoglobinuria, infarcts of kidney and brain, one postoperative patient. 5. 5. In liver disease, biliary obstruction produces levels of SGO-T ranging from 100 to 200 units, while active cell destruction as seen in hepatitis and active cirrhosis produces levels of 300 to 2,000 units.
Philosophy and the resolution of equality conflicts

This article examines Rowan’s discussion of my earlier paper (Messick, 1995). His warnings about the naturalistic fallacy and self-interest are well taken, but they constitute less serious threats to the usefulness of my suggestions than he indicates.
Pulsed Versus Conventional Radio Frequency Ablation for Lumbar Facet Joint Dysfunction

Low back pain (LBP) is a common source of discomfort and disability. A majority of the US adult population will experience and seek medical attention for the treatment of LBP at some point in their lives. The zygapophysial (facet) joint is a commonly accepted source of LBP and directed interventions exist to address facet-mediated LBP. Hoping to provide longer pain relief, the practice of medial branch denervation utilizing either pulsed or conventional thermal radiofrequency ablation (RFA) can be undertaken. While conventional thermal RFA is widely acknowledged as a viable method to denervate the medial branches for pain relief, pulsed radiofrequency (pRFA) has yet to gain widespread acceptance due to lack of evidence. However, pRFA for facet joint dysfunction may have a role in specific clinical situations.
Letter by Suri and Keller Regarding Article, “Annual Rate of Transvenous Defibrillation Lead Defects in Cardioverter-Defibrillators Over a Period of >10 Years”

To the Editor: The high failure rates of transvenous defibrillation leads in implantable cardioverter-defibrillators reported by Kleemann et al1 are quite disturbing. This article raises many issues about lead design, implantation techniques, and follow-up. First, the electrophysiology community craves leads with small diameters. This preference may have a negative impact on lead durability. Polyurethane, which is used to produce smaller leads, is more likely to degrade prematurely. Kleemann et al make the case for reevaluating the design of smaller leads. Although the poor performance of older leads is concerning, …
INFLUENCE OF FAT CONTENT AND PRESERVATIVES ON THE BEHAVIOR OF LISTERIA MONOCYTOGENES IN BEAKER SAUSAGE

Behavior of Listeria monocytogenes Scott A in pork liver sausage containing 22-67% fat, and antilisterial activities ofsodium lactate, sorbic acid, potassium sorbate and sodium propionate were studied during storage at 4C and 10C. Commercial pork liver sausage batter (22% fat), alone and with additions of lard (15, 30, and 45% by weight) were tested. Concentrations of 1.8% sodium lactate, 0.1% sorbate as the acid or the potassium salt, and 0.2% sodium propionate were tested in heat sterilized sausage inoculated with a 24 h culture of the organism (10 4 CFU/g). Fat content alone caused small reductions in cell numbers by the end of the storage periods: from log CFU/g of 9.9 to 9.4 after 14 days at 10C, and from 7.3 to 6.5 after 50 days at 4C in the basic sausage formulation and with 45% added fat, respectively. The inhibitory activities of lactate and propionate increased with increase in fat content, and were more pronounced at 4C, where the effects were listericidal. Inhibition by sorbic acid was least influenced by the fat content, and the potassium salt was less antilisterial than the acid.
Neuroimaging in traumatic brain imaging

Traumatic brain injury (TBI) is a common and potentially devastating clinical problem. Because prompt proper management of TBI sequelae can significantly alter the clinical course especially within 48 h of the injury, neuroimaging techniques have become an important part of the diagnostic work up of such patients. In the acute setting, these imaging studies can determine the presence and extent of injury and guide surgical planning and minimally invasive interventions. Neuroimaging also can be important in the chronic therapy of TBI, identifying chronic sequelae, determining prognosis, and guiding rehabilitation.
Research Leading To Revisions In Epa's Dispersant Effectiveness Protocol

ABSTRACT The current EPA protocol for testing the effectiveness of dispersants in the laboratory—the Swirling Flask Test—is fraught with difficulties because it has been found to give widely varying results in the hands of different testing laboratories. The objective of this study is to develop an understanding of the factors most responsible for this lack of reproducibility. Once that objective has been accomplished, the protocol will be modified to achieve better reproducibility in the hands of multiple laboratories. To accomplish the objective, fractional factorial experiments were conducted to determine which factors have the greatest impact on the variance of the method. Such factors as oil type, mixing speed, settling time, dispersant type, flask type, and operator were evaluated systematically and in a statistically rigorous manner. In addition, since the calibration curve used for analyzing the oil concentration dispersed in the seawater solution may also be a major source of variability, a syste...
Quality of life following epilepsy surgery for children with tuberous sclerosis complex.

Abstract Parents of children with tuberous sclerosis complex who underwent multistage resections for treatment of refractory seizures were offered a telephone questionnaire regarding quality of life (QOL) of child and family since surgery. Of 53 families, 39 responded. Age at epilepsy onset was birth to 3 months. Average duration of epilepsy before the first surgery was 5.1 years, and average age at surgery was 5.8. The average follow-up was 3.9. Seventy-seven percent had a > 90% reduction in disabling seizures. In all outcome categories, 46–85% had at least a moderate improvement in QOL. There was a significant correlation between QOL variables and Engel outcome class. Despite the potential burden posed by the aggressive surgical approach, including multiple surgeries and long hospitalization periods, 94% of parents would choose the same course once again. We conclude that aggressive surgical treatment of tuberous sclerosis complex-related refractory seizures is associated with significant control of epilepsy as well as improved QOL for the patient and family.
Notes on efficient ray tracing

There are many ways to make your ray tracer faster. If you're writing an interactive ray tracer, you've got to turn to your bottlenecks in your code and make them scream. You're probably spending the majority of your time computing ray-scene intersections (in some applications, ray-scene intersection may not be the bottleneck, for example Perlin noise is commonly a performance bottleneck for applications that use it heavily). To speed up ray-scene intersections, you use acceleration structures, but how do you get that extra factor of two in performance? This document is some informal notes on experience we've had at Utah on this topic. I do not include citations here. For the sources of these techniques see the bibliography for the chapters from the second edition of Fundamentals of Computer Graphics included in these notes. Several papers discussing these techniques are also included in these notes.
Effect of sex on oral cadmium dose responses in rats: Blood pressure and pharmacodynamics

Abstract Male and female weanling Sprague-Dawley rats were fed a commercial diet and given 0.0, 4.3, 8.6, and 17.2 μg cadmium (as CdCl 2 )/ml of drinking water for 39 weeks. During the latter part of this period systolic blood pressure was measured, and water intake was monitored during the entire experimentation period. It was found that females ingested about as much water and therefore cadmium as did males, which resulted in higher intake of Cd/100 g body wt in females. Cadmium concentrations were higher in all organs of females than in males, and the increase was dose related in both sexes. Zinc and copper were elevated in kidneys, but only zinc in liver of both sexes. Blood pressure was elevated in males in a dose-dependent fashion, but was not changed in females. There were a number of other parameters which showed marked sex differences. These differences are discussed in the light of the greater intake, absorption, and retention of cadmium by females. Suggestions of biochemical changes related to cadmium-induced hypertension are also examined.
On the Formation of Fatigue Cracks at Twin Boundaries

Abstract Fatigue crack formation at twin boundaries in OFHC copper has been studied as a function of twin boundary orientation with respect to applied stress. The operation of slip planes immediately adjacent to and parallel to the twin boundaries was found to be essential for crack formation at the boundaries. The role of twin boundary steps as dislocation sources is discussed with respect to increased plastic deformation at twin boundaries. Finally the cracking of alternate twin boundaries was observed and correlated with the operation of secondary slip planes.
URETEROSCOPIC TREATMENT OF URETEROPELVIC JUNCTION OBSTRUCTION

AbstractPurpose: Endopyelotomy has increasingly become well accepted as the optimal management for primary and secondary ureteropelvic junction obstruction. We report our experience with ureteroscopic endopyelotomy guided by endoluminal ultrasound.Materials and Methods: Ureteroscopic endopyelotomy was attempted in 27 patients with primary and 10 with secondary ureteropelvic junction obstruction. Retrograde pyelogram and endoluminal ultrasound were performed at the start of the procedure in all patients. Based on sonographic findings 5 patients were not considered candidates for the procedure. The remaining 13 men and 19 women were treated ureteroscopically with a rigid ureteroscope in 5 (15.6%), flexible in 20 (62.5%), and rigid and flexible in 7 (21.9%) patients. Stents were placed postoperatively for 6 to 10 weeks. The patients were followed for a mean duration of 10 months.Results: The procedure was completed in all patients. Average operating time was 95 minutes including the time for imaging. Sonogra...
Atmospheric nutrient inputs to three forest types in East Texas

Abstract The effect of forest type on atmospheric nutrient inputs to the forest ecosystem was measured for individual storm events for 1 year in three East Texas forest types: beechmagnolia, pine-mixed hardwoods and loblolly pine plantation. Total annual bulk precipitation inputs (kg/ha) for Ca, Mg, N, K and Na were, respectively: 5.0, 1.1, 4.1, 3.3 and 9.9. Total througfall inputs were increased by forest type, but the magnitude differed with each nutrient. Over 3 4 of the total K and 1 2 the total Mg throughfall input were due to the forest canopy. However 2 3 of the Ca and most of the Na throughfall input resulted from bulk precipitation. Although stemflow nutrient concentrations (ppm) were higher than throughfall and bulk precipitation, total annual stemflow nutrient inputs were only a minor component of the loblolly pine plantation ecosystem.
SVG for educational simulations

Helping students to understand complex ideas will always be problematic for teaching professionals. Often, the students can be limited by not only their imagination, but by their experiences. When trying to explain something that is outside of the students' imagination, it is often helpful to have either simple animations or even interactive simulations that the students can explore. The creation of interactive environments and the use of animation can greatly help educators get their point across and, as a result, help students comprehend the ideas.SVG (Scalable Vector Graphics) is an Extensible Markup Language (XML) dialect that allows the designer to create vector shapes from human-readable tags. Those vector shapes, created on their own, might not be that compelling. However, SVG can become interactive with the inclusion of SMIL (Synchronized Multimedia Integration Language - another dialect of XML) or dynamically created with technologies such as PHP (PHP Hypertext Preprocessor) or JavaScript/ECMAScript. This paper will explore the use of this new technology and it's ability to create animation and interactive learning environments. The differences between SVG and other plug-in technologies such as Flash will also be discussed.
A CUDA Based Implementation of Locally-and Feature-Adaptive Diffusion Based Image Denoising Algorithm

In this paper we introduce a parallel implementation of locally-and feature-adaptive diffusion based (LFAD) method for image denoising using NVIDIA CUDA framework and graphics processing units (GPUs). LFAD is a novel method for removing additive white Gaussian (AWG) noise in images reported to yield high quality denoised images [1]. It approaches each image region separately and uses different number of nonlinear anisotropic diffusion iterations for each region to attain best peak signal to noise ratio (PSNR). The inverse difference moment (IDM) feature is embedded into a modified diffusion function. As the method has attained highest performance in the class of advanced diffusion based methods and it is competitive with all the state-of-the-art methods, however computationally intensive when executed on the general purpose CPU. To improve the performance, we implemented using the CUDA computational framework. In order to minimize GPU kernel access to the global memory, we use shared memory and the texture memory per multiprocessor. The performance of the GPU implementation of the LFAD has been tested on the standard benchmark images. We demonstrate that with a single NVIDIA Tesla C2050 GPU we can expedite the sequential CPU implementation in most cases from 13 to 20 times.
Minding the gap: Interprofessional communication during inpatient and post discharge chasm care

Abstract Objective Poor communication is cited as a main cause of poor patient outcomes and errors in healthcare, and clear communication can be especially critical during transitions such as discharge. In this project, communication was standardized for clarity, and techniques were implemented to continue care from inpatient, to discharge, across the post-discharge chasm, to hand-off with the primary care provider (PCP). Methods The interprofessional (IP) quality improvement initiative included: (1) evidence-based teamwork system; (2) in situ simulation; (3) creation of an IP model of care; and (4) innovations in use of telehealth technology to continue care post-discharge. Results Measures inpatient/parent satisfaction and the attitudes of the care team have improved. Conclusions Traditional methods of communication and transition do not meet patient or healthcare provider needs. Communication must be standardized to be understandable and be used by the IP team. Care must continue post-discharge by utilizing technology to increase quality and continuity of care. Practice implications Improving and practicing communication skills may lead to reductions in healthcare errors and readmissions, and may decrease the length of stay and improve satisfaction of care teams.
A fast digital signal processor

This paper describes the design for a versatile digital processor using MSI logic circuits. The operations of filtering, correlation, beamforming, and spectrum analysis are easily handled in real time from signal sources encountered in sonar, seismic and underwater telemetry systems.
Practical experiments are informative, but never perfect

The design of empirical experiments involves making design decisions to trade off what is ideal against what is achievable. Researchers must weigh limitations on resources, metrics, and the current state of knowledge, against the validity of the results. In this paper, we report on the design decisions we made in a small controlled experiment and their effects on the conclusions of the study. The goal of the study was to measure the impact of requirements formats on maintenance tasks. We encountered problems with the subjects' lack of expertise in the technology used, the equivalence of subjects in our experiment conditions, and the number of subjects. These issues meant that we were able to draw conclusions about how subjects worked with the requirements formats, but not about the effect of the formats on the completeness of the implementation. We had a practical and doable experiment, but our results were not conclusive, only informative.
Tooth loss may be associated with increased circulatory mortality.

Article Title and Bibliographic Information The association of tooth loss with all-cause and circulatory mortality. Is there a benefit of replaced teeth? A systematic review and meta-analysis. Polzer I, Schwann C, Volzke H, Mundt T, Biffar R. Clin Oral Investig 2012;16(2):333-51. Reviewer Brian Laurence, DDS, PhD Purpose/Question To determine (1) whether the number of teeth is related to all-cause and circulatory mortality and (2) whether replaced teeth are protective against all-cause or circulatory mortality Source of Funding Government of Germany (Grant #01ZZ9603, 01ZZ0103, and 01ZZ0403 ) Type of Study/Design Systematic review with meta-analysis Level of Evidence Level 1: Good-quality, patient-oriented evidence Strength of Recommendation Grade Grade B: Inconsistent or limited-quality patient-oriented evidence
The Lodran primitive achondrite: petrogenetic insights from electron and ion microprobe analysis of olivine and orthopyroxene

Abstract The Lodran primitive achondrite is thought to represent some of the earliest events in the differentiation of chondritic asteroids. Most researchers who studied Lodran believe that it is a restite from which a melt, enriched in the incompatible trace and minor elements, was extracted. This process is reflected by a lack of feldspar in the Lodran mineral assemblage. Presumably, after or during melting, a reduction event took place resulting in an increase in Mg/Fe near the rims of both olivine and orthopyroxene. The reduction process is far more advanced in olivine than in pyroxene because of the more rapid Fe-Mg diffusion rates in olivine. Narrow reaction rims (
Characterization of link failures in multi-agent systems under the agreement protocol

The concept of detectability for a link with respect to an agent in a multi-agent system is introduced in this work. Link failures in the network are characterized in terms of their detectability, depending on how a link failure affects the response of a particular node in the system, and whether the link failure can be determined by observing that node's response. Sufficient conditions for detectability are provided and it is pointed out that link failures are detectable for a class of directed graphs with rooted out-branchings. The conceptually related notion of distinguishable directed information flow graphs is also introduced, and its importance in a multi-agent system is discussed. Simulation studies reveal that the obtained analytical results hold for randomly initialized network configurations.
Competitive Interactions Between Larvae from Divergent Strains of the Cowpea Weevil (Coleoptera: Bruchidae)

Previous studies demonstrated that larvae from an Indian strain (S) of the seed beetle Callosobruchus maculatus (F.) are much more competitive than larvae from a Nigerian strain (I) during both intra- and interstrain competition in a small host seed (mung bean). The competitive superiority of the S strain was Similarly evident when two larvae cooccurred in a larger host species (adzuki bean) that represented a novel host for both strains. If one or both larvae within a seed belonged to the S strain, survival to adult emergence was 50% lower than it was in the absence of competition. In contrast, survival decreased by only 15% when two I-strain larvae shared a seed. In head-to-head encounters between strains, most seeds produced a single survivor, and nearly 75% of adults from such seeds belonged to the S strain. Reciprocal crosses suggested an additive genetic component to these differences in competitive ability; the reduction in survival following competition was intermediate among F1 progeny. In contrast, the genetic basis of strain differences in adult weight was largely nonadditive, with hybrid progeny displaying a strong dominance deviation toward the heavier S strain. Differences in competitive ability were therefore independent of differences in body size between strains. Variation in competitive ability may ultimately be a consequence of variation in the sizes of host seeds typically encountered by beetle populations.
Extraposition: a case study in German sentence realization

We profile the occurrence of clausal extraposition in corpora from different domains and demonstrate that extraposition is a pervasive phenomenon in German that must be addressed in German sentence realization. We present two different approaches to the modeling of extraposition, both based on machine learned decision tree classifiers. The two approaches differ in their view of the movement operation: one approach models multi-step movement through intermediate nodes to the ultimate target node, while the other approach models one-step movement to the target node. We compare the resulting models, trained on data from two domains and discuss the differences between the two types of models and between the results obtained in the different domains.
Effect of phytic acid on growth and nitrogen retention in tilapia Oreochromis niloticus L.

Two experiments were conducted to determine the effect of phytic acid on nitrogen retention in tilapia (Oreochromis niloticus). The first experiment utilized graded levels of soybean meal (SBM) with or without hydrolysis of phytic acid. The second experiment utilized diets containing graded levels of purified phytic acid. In the first experiment, weight gain was inversely related to SBM inclusion beyond 250 g kg )1 2 of the crude protein (CP). Broken-line and quadratic models were applied to the growth data. The models suggest limiting inclusion to 380 and 170 g kg )1 CP for untreated and phytase treated SBM, respectively. The two SBM treatments exhibited similar trends in efficiency parameters. However, significant differences (P < 0.05) within treatments appeared when phytase treated SBM surpassed 250 g kg )1 CP, but not until 750 g kg )1 CP with untreated SBM. At similar rates of SBM incorporation, apparent net protein utilizations with untreated SBM were significantly higher beyond 250 g kg )1 CP (P < 0.05). In the second experiment, phytic acid did not affect efficiency parameters until the concentration was twice that in diets incorporating SBM as 1000 g kg )1 CP in a 330 g kg )1 CP diet. Phytic acid does not reduce nitrogen retention in tilapia, and its removal from SBM may decrease nitrogen retention.
Targeted polymeric magnetic nanoparticles for brain imaging

The purpose of this study was to develop targeted polymeric magnetic nanoparticle system for brain imaging. Near infrared dye indocyanine green (ICG) or p-gycoprotein substrate rhodamine 123 (Rh123) were encapsulated along with oleic acid coated magnetic nanoparticles (OAMNP) in a matrix of poly(lactide-co-glycolide) (PLGA) and methoxy poly(ethyleneglycol)-poly(lactide) (Met-PEG-PLA). The nanoparticles were evaluated for morphology, particle size, dye content and magnetite content. The in vivo biodistribution study was carried out using three groups of six male Sprague Dawley rats each. Group I received a saline solution containing the dye, group II received dye-loaded polymeric magnetic nanoparticles without the aid of a magnetic field, and group III received dye-loaded polymeric magnetic nanoparticles with a magnet (8000 G) placed on the head of the rat. After a preset exposure period, the animals were sacrificed and dye concentration was measured in the brain, liver, kidney, lungs and spleen homogenates. Brain sections were fixed, cryotomed and visualized using fluorescence microscopy. The particles were observed to be spherical and had a mean size of 220 nm. The encapsulation efficiency for OAMNP was 57%, while that for ICG was 56% and for Rh123 was 45%. In the biodistribution study, while the majority of the dose for all animals was found in the liver, kidneys and spleen, group III showed a significantly higher brain concentration than the other two groups (p < 0.001). This result was corroborated by the fluorescence microscopy studies, which showed enhanced dye penetration into the brain tissue for group III. Further studies need to be done to elucidate the exact mechanism responsible for the increased brain uptake of dye to help us understand if the magnetic nanoparticles actually penetrate the blood brain barrier or merely deliver a massive load of dye just outside it, thereby triggering passive diffusion into the brain parenchyma. These results reinforce the potential use of polymeric magnetically-targeted nanoparticles in active brain targeting and imaging.
Constrained fatigue life optimization of a NASVYTIS multiroller traction drive

A contact fatigue life analysis method for multiroller traction drives is presented. The method is based on the Lundberg-Palmgren analysis method for rolling element bearing life prediction, and also uses life adjustment factors for materials, processing, lubrication, and effect of traction. The analysis method is applied in an optimization study to the multiroller traction drive, consisting of a single-stage planetary configuration with two rows of stepped planet rollers of five rollers per row. The drive was approximately 25 centimeters in diameter by 11 centimeters long, having a nominal ratio of 15:1. The theoretically predicted drive life was 2510 hours at a nominal continuous power and speed of 74.6 kW (100 hp) and 75,000 rpm.
Analysis of frictional behavior and changes in morphology resulting from cartilage articulation with porous polyurethane foams

Porous polyurethane foams (PUR) have been extensively evaluated as meniscal replacement materials and show great promise enabling infiltration of cells and fibrocartilage formation in vivo. Similar to most materials, PUR demonstrates progressive degeneration of opposing cartilage; however, the damage mechanism is impossible to determine because no information exists on the frictional properties of PUR-cartilage interfaces. The goals of this study were to characterize the frictional behavior of a cartilage-PUR interface across a range of articulating conditions and assess the resulting morphological changes to the cartilage surface following articulation. Articular cartilage was oscillated against PUR or stainless steel using phosphate-buffered saline (PBS) and synovial fluid as lubricants. Following friction testing, cartilage and PUR samples were analyzed with environmental scanning electron microscopy and histological staining to determine changes in tissue morphology. Stribeck-surface analysis demonstrated distinct lubrication modes; however, boundary mode lubrication was dominant in cartilage-PUR interfaces and the low-friction pressure-borne lubrication mechanism present in native joints was absent. Microscopy noted obvious wear, with disruption of the collagen architecture and concomitant proteoglycan loss in cartilage articulated against PUR. These data collectively point to the importance of frictional properties as design parameters for implants and materials for soft tissue replacement.
The reactivities of aminoarsines toward diarsines

Abstract The reactions of Me2AsNR2 with Et2AsAsEt2, and of Et2AsNR2 with Me2AsAsMe2 (R = Me or Et), were investigated over the temperature range 24–75°C by using 1H and 13C NMR spectroscopy. The NMR data indicate the initial formation of the unsymmetrical diarsine, Me2AsAsEt2, and the respective dialkylamino-dialkylarsine, Et2AsNR2 or Me2AsNR2. The Me2AsAsEt2 then undergoes symmetrization to yield Me2AsAsMe2 and Et2AsAsEt2. Additional competitive reactions involving AsAs-AsNandAsN-AsN systems also occur in the reaction mixture. In each case, the percentage distribution of products and reactants in the studied systems at equilibrium is independent of temperature within experimental measurement. The reaction rates are dependent upon the nature of R and the alkyl group in the diarsine. In addition, equilibrium constants for several competitive reactions have been determined.
Influence functionals with semiclassical propagators in combined forward-backward time

In a recent letter [Chem. Phys. Lett. 291, 101 (1998)] we presented a semiclassical methodology for calculating influence functionals arising from many-body anharmonic environments in the path integral formulation of quantum dynamics. Taking advantage of the trace operation associated with the unobservable medium, we express the influence functional in terms of a single propagator along a combined forward–backward system path. This propagator is evaluated according to time-dependent semiclassical theory in a coherent state initial value representation. Because the action associated with propagation in combined forward and backward time is governed by the net force experienced by the environment due to its interaction with the system, the resulting propagator is generally a smooth function of coordinates and thus amenable to Monte Carlo sampling; yet, the interference between forward and reverse propagators is fully accounted for. In the present paper we present a more elaborate version of the semiclassica...
Assessing the consequences of global change for forest disturbance from herbivores and pathogens.

Herbivores and pathogens impact the species composition, ecosystem function, and socioeconomic value of forests. Herbivores and pathogens are an integral part of forests, but sometimes produce undesirable effects and a degradation of forest resources. In the United States, a few species of forest pests routinely have significant impacts on up to 20 million ha of forest with economic costs that probably exceed $1 billion/year. Climatic change could alter patterns of disturbance from herbivores and pathogens through: (1) direct effects on the development and survival of herbivores and pathogens; (2) physiological changes in tree defenses; and (3) indirect effects from changes in the abundance of natural enemies (e.g. parasitoids of insect herbivores), mutualists (e.g. insect vectors of tree pathogens), and competitors. Because of their short life cycles, mobility, reproductive potential, and physiological sensitivity to temperature, even modest climate change will have rapid impacts on the distribution and abundance of many forest insects and pathogens. We identify 32 syndromes of biotic disturbance in North American forests that should be carefully evaluated for their responses to climate change: 15 insect herbivores, browsing mammals; 12 pathogens; 1 plant parasite; and 3 undiagnosed patterns of forest decline. It is probable that climatic effects on some herbivores and pathogens will impact on biodiversity, recreation, property value, forest industry, and even water quality. Some scenarios are beneficial (e.g. decreased snow cover may increase winter mortality of some insect pests), but many are detrimental (e.g. warming tends to accelerate insect development rate and facilitate range expansions of pests and climate change tends to produce a mismatch between mature trees and their environment, which can increase vulnerability to herbivores and pathogens). Changes in forest disturbance can produce feedback to climate through affects on water and carbon flux in forest ecosystems; one alarming scenario is that climate warming may increase insect outbreaks in boreal forests, which would tend to increase forest fires and exacerbate further climate warming by releasing carbon stores from boreal ecosystems. We suggest a list of research priorities that will allow us to refine these risk assessments and adopt forest management strategies that anticipate changes in biotic disturbance regimes and mitigate the ecological, social, and economic risks.
Host-derived CD4+ T cells attenuate stem cell–mediated transfer of autoimmune arthritis in lethally irradiated C57BL/6.g7 mice

Objective In the K/BxN mouse model of inflammatory arthritis, T cells carrying a transgenic T cell receptor initiate disease by helping B cells to produce arthritogenic anti–glucose-6-phosphate isomerase (anti-GPI) autoantibodies. We found that lethally- irradiated lymphocyte-deficient C57BL/6 (B6).g7 (I-Ag7+) recombinase-activating gene–deficient (Rag−/−) mice reconstituted with K/BxN hematopoietic stem and progenitor cells exhibit arthritis by week 4. In contrast, healthy B6.g7 recipients of K/BxN hematopoietic stem and progenitor cells show only mild arthritis, with limited extent and duration. The objective of this study was to investigate the factors responsible for the attenuation of arthritis in B6.g7 recipients. Methods Antibody responses were measured by enzyme-linked immunosorbent assay. Fluorescence-activated cell sorting analyses were performed for testing chimerism, expression of markers of activation and suppression, tetramer binding, and intracellular cytokines in CD4+ T cells. Suppressive activity of CD4+ T cells was studied by adoptive transfer. Results Titers of anti-GPI antibodies in reconstituted B6.g7 mice were ∼60-fold lower than in reconstituted B6.g7 Rag−/− mice. Examination of chimerism in the reconstituted B6.g7 mice showed that B cells and myeloid cells in these mice were donor derived, but CD4+ T cells were primarily host derived and enriched for cells expressing the conventional regulatory markers CD25 and FoxP3. Notably, CD4+CD25−FoxP3− T cells expressed markers of suppressive function (CD73 and folate receptor 4), and delayed disease after adoptive transfer. Activation of donor-derived CD4+ T cells was reduced, and thymic deletion of these cells appeared increased. Conclusion Despite myeloablation, host CD4+ T cells having a regulatory phenotype emerge in these mice and attenuate autoimmunity.
Fast methods for determining the evolution of uncertain parameters in reaction-diffusion equations

Abstract An important problem in mathematical modeling in science and engineering is the determination of the effects of uncertainty or variation in parameters and data on the output of a deterministic nonlinear operator. For example, such variations may describe the effect of experimental error in measured parameter values or may arise as part of a sensitivity analysis of the model. The Monte-Carlo method is a widely used tool for determining such effects. It employs random sampling of the input space in order to produce a pointwise representation of the output. It is a robust and easily implemented tool with relatively low dependence on the number of parameters. Unfortunately, it generally requires sampling the operator very many times at a significant cost, especially when the model is expensive to evaluate. Moreover, standard analysis provides only asymptotic or distributional information about the error computed from a particular realization. In this paper, we present an alternative approach for ascertaining the effects of variations and uncertainty in parameters in a reaction-diffusion equation on the solution. The approach is based on techniques borrowed from a posteriori error analysis for finite element methods. The generalized Green’s function solving the adjoint problem is used to efficiently compute the gradient of a quantity of interest with respect to parameters at sample points in the parameter space. This derivative information is used in turn to produce an error estimate for the information computed from the sample points. The error estimate provides the basis for both deterministic and probabilistic adaptive sampling algorithms. The deterministic adaptive sampling method can be orders of magnitude faster than Monte-Carlo sampling in case of a moderate number of parameters. The gradient can also be used to compute useful information that cannot be obtained easily from a Monte-Carlo sample. For example, the adaptive algorithm yields a natural dimensional reduction in the parameter space where applicable. After describing the new methodology in detail, we apply the new method to analyze the parameter sensitivity of a predator–prey model with a Holling II functional response that has six parameters.
Toward Further Modernization of the Study of New Nations

Where are we now in the study of new nations? Three books that are the product of nineteen experienced minds should help to establish our present position. Nation-Building grew out of a panel discussion at the 1962 meeting of the American Political Science Association organized by Karl W. Deutsch. Old Societies and New States reflects the work of the Committee for the Comparative Study of New Nations at the University of Chicago. New Nations represents the thinking of that British school of social anthropologists who, beginning with Radcliffe-Brown, have been especially interested in problems of process, authority, change, and conflict in society.
The Interaction of a Minute Mutation with a Sex-linked Lethal of Drosophila Melanogaster

Despite the fact that the analyses of lethal mutations of Drosophila present a promising approach to the study of gene action, phase specificity has been determined for only a few and the possibility of interaction between lethals and other mutants has received little attention.' An experiment was designed, therefore, to determine the effect of a minute mutation, M(3)w, upon the lethal, 1(1)7, and the average time of death and the distribution of deaths among the 1(1)7 larvae. Method.-The recessive sex-linked lethal 1(1)7, characterized by the appearance of melanomas, was most recently investigated by Russell2 who estimated that death occurs in the male larvae about 100 hrs. after hatching. The minute M(3)w, is lethal when homozygous, but Dunn and Mossige3 found that the heterozygous mutation causes a pronounced retardation in the rate of larval development. To test the effect of this retardation upon the activity of 1(1)7 it was necessary to obtain flies which could be crossed to produce male larvae containing 1(1)7 only and other males with both M(3)w and 1(1)7. Accordingly, two stocks were e 1(1)7 prepared one of which contained females and the other e In(l)dl-49,
Batch-mixed iron treatment of high arsenic waters.

Abstract This paper develops batch-mixed treatment with zero-valent iron as a point-of-use technology, appropriate for arsenic removal from water stored within rural homes in Bangladesh and West Bengal, India, where arsenic poisoning has affected an estimated 20 million people. Batch tests with iron yielded the following results: (1) High arsenic removal (>93%) was achieved from highly arsenated waters (2000 μg/L) over short contact times (0.5–3 h) with iron filings added at doses ranging from 2500 to 625 mg/L; (2) Most rapid arsenic removal was observed in head-space free systems with sulphates present in solution, while phosphate buffers were observed to inhibit arsenic removal by iron; (3) The arsenic removed from water was found to be strongly bound to the elemental iron filings, such that the treated water could be decanted and iron could be reused at least 100 times; (4) Some iron dissolved into water over the contact period, at concentrations ranging from 100 to 300 μg/L, which are within safe drinking water limits. These results indicate that, with appropriate assessment of water chemistry in the affected region, treatment with metallic iron followed by simple decantation can be used as a practical, in-home, point-of-use technique for reducing human exposure to arsenic in drinking water.
Complex FIR block adaptive algorithm employing optimal time-varying convergence factors

The Complex Least Mean Square algorithm (Complex LMS) has been widely used in various adaptive filtering applications, e.g. in the wireless communications and biomedical fields, due to its computational simplicity. However, the main drawback of the Complex LMS algorithm is its slow convergence. In addition, the performance is dependent on the choice of the convergence factor or learning rate. In this paper, a novel complex block adaptive algorithm is presented that overcomes the performance limitation of the Complex LMS. The proposed algorithm (Complex OBA-LMS) derives independent time-varying convergence factors for the real and imaginary components of the FIR complex adaptive filter coefficients. Furthermore, the convergence factors are updated at each block iteration. The convergence speed and accuracy of the Complex OBA-LMS algorithm are investigated and compared with the Complex LMS algorithm. Simulation results show that the proposed technique exhibits superior performance at the expense of a modest increase in computational complexity for different training inputs.
Vision-Based Target Geo-Location Using Feature Tracking ∗

A method for determining the location of a fixed ground target when imaged from the air using a camera equipped Micro Air Vehicle (MAV) is developed. The ground objects’ elevation is assumed known. Rather than a “one shot” affair, multiple bearing measurements of the ground object taken as the aircraft flies around the target are used. This makes it possible for the adverse effects of both the random measurement errors and the systematic measurement errors, a.k.a., attitude sensor biases, to be mitigated. The main result of this paper is that when bearing measurements of a target are taken over time, the target’s position and the MAV’s systematic attitude measurement errors can be jointly estimated using linear regression. As a result, the target is accurately geo-located and the attitude sensors are calibrated. If only one target bearing measurement can be taken, the attitude sensors will be calibrated prior to arrival at the target area using an Initial Point (IP). The technique has been successfully tested on actual flight data.
Second-order schedules and the analysis of human drug-seeking behavior

Behavior maintained by drug injections can be enhanced by using simple schedules as components of more complex second-order schedules. Under second-order schedules, completion of the component schedule, rather than an individual response, produces the drug injection according to another schedule. Each component schedule terminates with the brief presentation of a stimulus that has been associated with drug injection. Research over the past 30 years using these procedures with monkeys and human subjects has allowed an evaluation of the role of conditioned environmental stimuli in the acquisition, maintenance, extinction, and reinstatement of drug--seeking behavior. These results have provided a cross-validation of human and animal models of drug abuse which would not have been possible using simple schedules of reinforcement.
Genome-wide Analysis of the Functions of a Conserved Surface on the Corepressor Tup1

The general transcriptional repressor Tup1 is responsible for the regulation of a large, diverse set of genes in Saccharomyces cerevisiae, and functional homologues of Tup1 have been identified in many metazoans. The crystal structure for the C-terminal portion of Tup1 has been solved and, when sequences of Tup1 homologues from fungi and metazoans were compared, a highly conserved surface was revealed. In this article, we analyze five point mutations that lie on this conserved surface. A statistical analysis of expression microarrays demonstrates that the mutant alleles are deficient in the repression of different subsets of Tup1-regulated genes. We were able to rank the mutant alleles of TUP1 based on the severity of their repression defects measured both by the number of genes derepressed and by the magnitude of that derepression. For one particular class of genes, the mutations on the conserved surface disrupted recruitment of Tup1 to the repressed promoters. However, for the majority of the genes derepressed by the Tup1 point mutants, recruitment of Tup1 to the regulated promoters is largely unaffected. These mutations affect the mechanism of repression subsequent to recruitment of the complex and likely represent a disruption of a mechanism that is conserved in fungi and metazoans. This work demonstrates that the evolutionarily conserved surface of Tup1 interacts with two separate types of proteins-sequence-specific DNA-binding proteins responsible for recruiting Tup1 to promoters as well as components that are likely to function in a conserved repression mechanism.