cssi/SciSciGPT-SciSciNet huggingface dataset:
Prove Them Wrong Be There for Secondary Students with an Emotional or Behavioral Disability

An 18-year-old senior in high school walks into the classroom with a hood pulled over his eyes, his ear buds screaming heavy metal music, carrying no textbooks, and acknowledging no one in the clas...
Junctive/Disjunctive Processes in Organic Chemistry

This chapter defines various junctive and disjunctive processes, which involve the formation and breakdown of directed bonds. It defines fundamental and topological junctive simplexes, and identifies the fundamental types of junctive/disjunctive processes. A junctive process is one in which partial or complete σ and/or π bonding takes place between two unbonded atoms. A disjunctive process is the exact reverse of a junctive process. For a given reacting site, site junctivity (j a ) is the number of directed bonds formed at that site and simplex junctivity (j s ) is the sum total of all the site ligogenicities within the simplex. Molecular junctivity (J) is the sum total of all the simplex junctivities, and the net process junctivity, J for , the difference of the process junctivity (J g ) and process disjunctivity (J l ). The junctivity of the reverse process, J rev , is the negative of J for . The designations presented are useful for describing mechanistic steps from ground state to transition state and vice versa and ground state to ground state (reactant to intermediate, reactant to product). In effect, the said designations are applicable to any two points on the potential energy surface representing a junction or disjunction in a chemical process. The concept of junctivity is in principle, extendable to self-assembly of 2D and 3D H-bonded networks.
Viability of karezes (ancient water supply systems in Afghanistan) in a changing world

The Afghanistan population living far from rivers relies upon groundwater delivered from karezes (sub-horizontal tunnels). Karezes exploit unconfined groundwater in alluvial fans recharged largely by snowmelt from the Hindu Kush, the central mountain range of the country. Since the multi-year drought that began in 1998, many karezes have stopped flowing. This study characterizes the hydraulics of a kariz, the potential for reduced groundwater recharge because of climate change, and the impact of increasing population on kariz water production. A typical kariz in Afghanistan is 1–2 km long with a cross-section of 1–2 m2 and gradient of 1 m km−1. MODFLOW simulations show that water delivery from a kariz can be modeled by imposing a high ratio of kariz hydraulic conductivity to aquifer hydraulic conductivity on the cells representing the kariz. The model is sensitive to hydraulic conductivity, kariz gradient, and length of the kariz in contact with the water table. Precipitation data are scarce in Afghanistan, but regional data show a long-term trend of decreased snow cover, and therefore strong likelihood of decreased aquifer recharge. Population in Afghanistan has increased at a rate of about 2.2 % over the past several decades. An assessment of a six-district region within Kandahar Province where karezes are the most likely source of water indicates that water demand could have caused water tables to decline by 0.8–5.6 m, more than enough to cause karezes to stop flowing. These results suggest that kariz water production is not sustainable under current climate- and population-growth trends.
Psychological Essentialism and Opposition to Human Embryonic Stem Cell Research

Scientists must destroy a human embryo to create an embryonic stem cell line. For those who believe the human embryo is a human person, this act is tantamount to murder. However, belief in the personhood of the embryo rests on hidden intuitions. This article applies research from the field of cognitive psychology to analyze religious teachings, policy reports, and Congressional debates over human embryonic stem cell research.
Assessment of dietary vitamin D requirements during pregnancy and lactation.

Concerns about vitamin D have resurfaced in medical and scientific literature because the prevalence of vitamin D deficiency in the United States, particularly among darkly pigmented persons, has increased. The primary goals of this review were to discuss past and current literature and to reassess the dietary reference intake for vitamin D in adults, with particular focus on women during pregnancy and lactation. The appropriate dose of vitamin D during pregnancy and lactation is unknown, although it appears to be greater than the current dietary reference intake of 200-400 IU/d (5-10 microg/d). Doses of 90 ng/mL, whereas doses < 1000 IU/d appear, in many cases, to be inadequate for maintaining normal circulating 25-hydroxyvitamin D concentrations of between 15 and 80 ng/mL. Vitamin D plays no etiologic role in cardiac valvular disease, such as that observed in Williams syndrome, and, as such, animal models involving vitamin D intoxication that show an effect on cardiac disease are flawed and offer no insight into normal human physiology. Higher doses of vitamin D are necessary for a large segment of Americans to achieve concentrations equivalent to those in persons who live and work in sun-rich environments. Further studies are necessary to determine optimal vitamin D intakes for pregnant and lactating women as a function of latitude and race.
Exposure to Mixtures of Metals and Neurodevelopmental Outcomes: A Multidisciplinary Review Using an Adverse Outcome Pathway Framework

Current risk assessment guidance calls for an individual chemical-by-chemical approach that fails to capture potential interactive effects of exposure to environmental mixtures and genetic variability. We conducted a review of the literature on relationships between prenatal and early life exposure to mixtures of lead (Pb), arsenic (As), cadmium (Cd), and manganese (Mn) with neurodevelopmental outcomes. We then used an adverse outcome pathway (AOP) framework to integrate lines of evidence from multiple disciplines based on evolving guidance developed by the Organization for Economic Cooperation and Development (OECD). Toxicological evidence suggests a greater than additive effect of combined exposures to As-Pb-Cd and to Mn with any other metal, and several epidemiologic studies also suggest synergistic effects from binary combinations of Pb-As, Pb-Cd, and Pb-Mn. The exposure levels reported in these epidemiologic studies largely fall at the high-end (e.g., 95th percentile) of biomonitoring data from the National Health and Nutrition Examination Survey (NHANES), suggesting a small but significant potential for high-end exposures. This review integrates multiple data sources using an AOP framework and provides an initial application of the OECD guidance in the context of potential neurodevelopmental toxicity of several metals, recognizing the evolving nature of regulatory interpretation and acceptance.
Analysis of equine cisterna magna cerebrospinal fluid for the presence of some monoamine neutrotransmitters and transmitter metabolites

Small volumes (0.05 ml) of cisterna magna cerebrospinal fluid (CSF) from 23 neurologically normal horses were analysed for the monoamine neurotransmitters dopamine, norepinephrine, epinephrine, serotonin and their metabolites using high pressure liquid chromatography and electrochemical detection. Two metabolites, homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were present in all CSF samples. The deaminated and methylated metabolite of dopamine, HVA, was present at a mean concentration of 42.33±3.14 ng/ml of CSF. The deaminated metabolite of serotonin, 5-HIAA, was present at a mean concentration of 45.52±3.65 ng/ml of CSF. A positive correlation was found between the CSF concentrations of HVA and 5-HIAA (r=0.72, p=0.0003). The mean ratio of HVA to 5-HIAA concentrations was 1.07±0.05. The ratios of HVA to 5-HIAA concentrations were found to be more indicative of the serotonergic metabolite 5-HIAA (r=−0.62, p=0.0016) than the dopaminergic metabolite HVA (r=0.11, p=0.60). There was a stronger relationship between the concentrations of 5-HIAA and the ratios of HVA to 5-HIAA in male CSF (r=−0.85, p=0.0006) than in female CSF (r=−0.54, p=0.01). Concentrations of CSF neurotransmitter metabolites were evaluated in horses grouped by age (0–4, 5–9 and 10–13 years). The youngest group of horses had a significantly (p=0.003) greater CSF concentration of HVA than of 5-HIAA. The 10–13-year-old horses had a significantly (p=0.02) lower mean CSF HVA concentration than the 0–4-year-old horses. No age-related differences in CSF 5-HIAA concentrations were detected.
CD4 T Lymphocyte Count and the Radiographic Presentation of Pulmonary Tuberculosis: A Study of the Relationship Between These Factors in Patients With Human Immunodeficiency Virus Infection

Background Pulmonary infection and tumor in the AIDS population has a variable clinical and radiographic presentation. The association between the radiographic presentation of pulmonary tuberculosis and CD4 T lymphocyte count in the HIV-infected patient is investigated in order to provide an empirical approach for early diagnosis, treatment, and isolation of infected subjects. Methods: A retrospective analysis of chest radiographs, CD4 T lymphocyte counts, and clinical history of 35 subjects from 3 urban hospitals was performed. All subjects were HIV-seropositive and had culture-proven pulmonary tuberculosis. Radiographs were evaluated for the presence of either a pattern characteristic of post-primary tuberculosis (typical pattern) or a pattern uncharacteristic of post-primary infection (atypical pattern). Results: Twenty-one of 26 subjects with a CD4 T lymphocyte count less than 0.20×10 9 cells/L, whereas only 1 of 9 subjects with a CD4 T lymphocyte count of 0.20×10 9 cells/L or more presented with an atypical pattern of pulmonary tuberculosis (p with atypical versus typical radiographic pattern of post-primary pulmonary tuberculosis were 0.069 × 10 9 cells/L (n=22) and 0.323×10 9 cells/L (n=13), respectively (p 9 cells/L). Atypical radiographic pattern included diffuse and lower lobar opacities, pleural effusion, mediastinal adenopathy, interstitial nodules, and a normal chest radiograph. Conclusion: AIDS patients presenting with CD4 count less than 0.20×10 9 cells/L and an atypical radiographic pattern for pulmonary tuberculosis are at risk for tuberculous infection requiring appropriate treatment and isolation until the diagnosis of pulmonary tuberculosis has been excluded.
The influence of implant geometry on the stress distribution around dental implants.

A three-dimensional finite element stress analysis has been used to investigate the influence that variations in the infrastructural geometry of a blade-type dental implant have on the stress distribution around LTI carbon and aluminum oxide implants. The finite element model was constructed based upon an analysis of serial sections of a retrieved implant specimen. In addition to the implant, the finite element model contained a three-unit fixed bridge connected to a natural molar with periodontal membrane. The removal of the bridge allowed for the study of freestanding implants and molar. Variations in the implant blade geometry were found to produce significant changes in the stress distributions around bridged and freestanding aluminum oxide implants. Very little effect, however, was observed around the LTI carbon implants. A comparison of the stresses around the freestanding molar and the stresses around the bridged and freestanding implants was made to determine the implant dessign that came closest to reproducing the stress state around the modeled molar. The LTI carbon system that best achieved this stress state was found to be a full-blade implant used in conjunction with a tooth as an abutment in a fixed bridge. The aluminum oxide system that best achieved this stress state was found to be of the post or short-blade design used as a freestanding implant.
A high resolution camera for bubble chamber photography

Abstract An account is given of the development of a camera system designed for the SLAC 1-m bubble chamber. The camera is used to photograph the decay vertices of charmed particles.
Relatively low endogenous fatty acid mobilization and uptake helps preserve insulin sensitivity in obese women

Relatively low endogenous fatty acid mobilization and uptake helps preserve insulin sensitivity in obese women
Fractal dimension as a measure of roughness of concrete fracture trajectories

Abstract In this article, fractal characterization of concrete and mortar fracture trajectories is carried out. These trajectories were either sectioned from a replica of the fracture surface, profiled from a digitized image of the fracture surface, or generated via fractional Brownian motion simulation. Compact tension fractured concrete specimens with three different maximum aggregate sizes ( d max = 4.7, 18.8, and 37.5 mm ) and a projected fracture area (ligament area) of 125 × 367.5 mm were analyzed. Two methods, step divider and variogram, were utilized to evaluate the fractal dimension of the fracture trajectories. The fractal dimensions of concrete fracture trajectories calculated using these methods were in the range of 1.07 to 1.25. The variogram method yielded higher values than the step divider method. Synthetic profiles generated via fractional integrals of Brownian motion showed a good visual similarity to the actual fracture profiles. Advanced Cement Based Materials 1994; 1, 169–177
Comparative Analysis of the Earl Warren and Warren Burger Supreme Courts

The past three decades have witnessed an enormous increase in the amount of litigation concerning the procedural rights of the criminally accused. Although the task of monitoring this criminal process was, at common law, left to the many states, perhaps this increase in litigation was a direct result of the appointment of Earl Warren as Chief Justice in 1953 and Warren Burger in 1969. A close examination of the many decisions reached by the Supreme Court during this period manifests an attempt to provide those enmeshed in the criminal justice system with adequate protection from state common law rules and statutes. For example, by 1961, the so-called “exclusionary evidence principle” was applied to State prosecutions, rendering inadmissible at trial any evidence seized in violation of the defendant's Fourth Amendment rights. In so doing, it often required the release of a factually guilty defendant in order to insure an appropriate process. By 1970, with the appointment of Warren Burger, the courts viewed...
High performance detection filter for impulse noise removal in images

A high performance detection (HPD) filter is proposed for impulse noise removal in images. In this approach, the noisy pixels are detected iteratively through several phases, based on a set of unique similarity criteria. Simulation results show that the HPD filter outperforms others at medium to high noise rates and suppresses impulse noise effectively while preserving image details, even thin lines.
Toxicologic and acute lethal hazard evaluation of thermal decomposition products of synthetic and natural polymers.

Abstract Thermal decomposition products from a series of cellular synthetic polymers and several other polymers, synthetic or natural, were investigated. Evaluation of sensory irritating properties, physiological stress, asphyxiation, acute mortality, and histopathological changes due to the thermal decomposition products revealed a very wide range of potency among them. A classification system is proposed for making comparison to standard materials such as wood or fiberglass insulation and an acute lethal hazard system is presented for comparison of materials used for the same function, i.e., insulation.
Graphene stacks as the darkest material

We present the fabrication and characterization of a graphene stack that can function as the darkest material and serve as the basis for a new class of sensitive, high-speed photodetectors.
A multidimensional scale to measure the reproductive concerns of young adult female cancer survivors.

Purpose Concerns about fertility and parenthood are important to many young adult (YA) female cancer survivors and are associated with poorer quality of life. We aimed to develop a new scale to comprehensively measure these concerns so that they can be better addressed.
Oxygen vacancies in silica and germania glasses

A statistical mechanical technique with no adjustable parameters is used to calculate the density of oxygen vacancies in pure germania glasses. The calculated values are in fair agreement with the experimental values obtained by Schurman. A slightly different technique utilizing one adjustable parameter is used to calculate the density of oxygen vacancies in binary germano-silicate glasses. The results are also in fair agreement with experimental values.
THE PATTERN OF THE MICROCIRCULATORY BED IN THE VENTRICULAR MYOCARDIUM OF DOMESTIC MAMMALS.

Observations, as determined by injections of India ink through the coronary arteries of isolated and perfused beating hearts, were presented. Tissue blocks were removed from the right and left ventricular walls and the interventricular septum, sectioned and cleared for microscopic examination and photomicrography. The term microcirculatory bed was defined as those vessels 100 μ and smaller in diameter. The descriptions were based on 76 normal adult hearts of both sexes of six domestic species. The arterioles divided by dichotomous branching until the final division resulted in two daughter capillaries. At no time was a capillary observed leaving an arteriole larger than 15 μ in diameter. The arterioles had a modified type of end artery pattern. Arterial anastomoses were uncommon in the areas and species examined. A specific area of a cardiac muscle fascicle was supplied by several arterioles whose capillaries intermeshed. The implications of this concept in relation to micro-embolism were explored. Capillary anastomoses were frequent but the connecting vessel was only about 20 μ in length. Three types of capillary anastomoses were identified. Capillaries did not cross the muscle fascicles of the myocardium. Collecting venules were often distinctive in their morphological pattern. “Turnip root” patterns were observed in all species and represented the local venous collection of a muscle fascicle. A venule's capillary components were usually from several arteriolar sources. Supported in part by research grant HE 04217-05 from the National Heart Institute, U. S. Public Health Service.
Illegitimate birth and the English clergy, 1198-1348

This article studies illegitimacy, which was a canonical impediment to ordination, within the English clergy between 1198 and 1348. Scholarship on illegitimacy in the clergy has previously relied on canon law, conciliar decrees, and dispensations preserved in papal registers. Using these sources, historians have concluded that the papacy tightly controlled illegitimate men's access to orders, that the burdens of obtaining dispensations for illegitimacy (the defectus natalium) could pose substantial obstacles to a man's clerical career, and that priests' sons made up a significant percentage of the illegitimate clergy. This article, which draws on the large and previously untapped body of dispensations surviving in English episcopal registers to supplement the papal sources, reaches different conclusions. It argues that the great majority of illegitimate clerics in the thirteenth- and fourteenth-century English clergy were the sons of unmarried lay parents. It further argues that dispensations were more readily accessible than has previously been suggested, and emphasises the importance of local branches of the ecclesiastical hierarchy to an individual's efforts to attain a dispensation to enter holy orders.
Autoshaping the pigeon’s keypeck in a dark chamber

Pigeons were exposed to an autoshaping procedure in a dark chamber with a punctate conditioned stimulus signaling response-independent food presentations. Contrary to other findings, a high rate of autoshaped keypecking emerged and was sustained in all subjects. Although these results support a cue localization hypothesis, they also implicate the importance of the context in which a conditioned stimulus is presented in the autoshaping paradigm.
Multiple exciton generation and electrical extraction from a PbSe quantum dot photoconductor

Multiple exciton generation and subsequent electrical extraction from a thin film photoconductive device constructed from PbSe nanocrystal quantum dots are demonstrated. The hydrazine treatment of the PbSe film drastically improves the conductivity of the film while maintaining excellent optical and structural film quality. The effects of multiple exciton generation and electrical extraction (electrons collected per photon absorbed) were quantified as a function of incident photon energy from 1.55to3.1eV. The multiple carrier extraction (>100%) was observed at photon energies greater than 2.8 times of the quantum dot bandgap with ∼210% measured at 4.4 times the bandgap.
Simultaneous monitoring of acoustic emission and ultrasonic attenuation during fatigue of 7075 aluminium

Abstract Although ultrasonic attenuation monitoring has been demonstrated to be capable of providing a quantitative assessment of integrity during fatigue, much less success has been achieved in developing the corresponding capability using acoustic emission monitoring. A thorough review of the previous work employing either technique for the examination of aluminium during fatigue is presented. In addition, results from simultaneous monitoring of ultrasonic attenuation and acoustic emission during the fatigue of 7075 aluminium demonstrate the feasibility for utilizing acoustic emission as a means of continually surveying the structural integrity of a piece. It is evident from the results that, due to the passive nature of the acoustic emission monitoring, sensor location relative to failure location is not critical, thus allowing surveillance of structures with irregular geometries. However, the utilization of high frequency sound in ultrasonic attenuation monitoring makes this technique for inspecting known problem areas extremely useful in the presence of intense environmental noise. The overall findings indicate the capability of both techniques for assessing structural integrity during fatigue while providing complementary practical advantages.
Selected sexually transmitted diseases and their relationship to HIV

Abstract Although sexually transmitted diseases (STDs) are underreported and underrecognized, they are a major source of morbidity, mortality, and represent a major socioeconomic cost in developing and industrialized nations. Individuals who develop STDs are often coinfected with human immunodeficiency virus (HIV). Coinfection with HIV both facilitates the natural history of STDs and worsens the clinical picture. The objective of this article is to provide a review to the practicing clinician on the epidemiology, clinical manifestations, methods of diagnosis, and treatment for four cutaneous STDs—chancroid, genital herpes, granuloma inguinale, and lymphogranuloma venereum—in coinfected HIV patients.
Oscillations of weakly non-linear, self-excited systems under multi-frequency parametric excitation

Abstract A class of self-excited mechanical or structural systems subjected to parametric excitation is considered. The systems have an arbitrary number of generalized co-ordinates. The equations of motion include weak quadratic and cubic non-linearities in the stiffness, small “negative” linear damping terms, and small “positive” cubic damping terms. Special cases are van der Pol's equation and Rayleigh's equation. The parametric excitation includes multiple frequencies λm. By using the method of multiple scales, the following resonances are analyzed: λs ≈ 2ωq (principal parametric resonance), λs ≈ ωq, λs ± λt ≈ 2ωq, and λs + λt ≈ ωr−ωq, where the ωn are natural frequencies of the system. Steady state response amplitudes are determined and plotted as functions of a detuning parameter, excitation amplitudes and, when λs ± λt ≈ 2ωq, a measure of the relative values of λs and λt.
Detection and classification of land-mine-like targets in a non-Gaussian noise environment

Many statistical signal processing approaches to target detection and classification assume the measurement is corrupted by independent, identically distributed white Gaussian noise. This common assumption often results in simpler, and less computationally, intense, mathematically realization for the processor. However, in many instances it is not clear if this assumptions regarding the statistics of the noise is valid. In this paper, the effects of assuming i.i.d. white Gaussian noise on the performance of likelihood ratio detectors and maximum likelihood classifiers implemented in a non-Gaussian noise environment are discussed. If the assumptions regarding the noise distribution are accurate, the resulting likelihood ratio detector and classifier are optimal. However, if those assumptions are inaccurate, performance may be degraded. We present simulation result illustrating the effects of mismatch between the assumed and actual noise distributions on detection and classification performance for likelihood ratio processors derived under several assumptions regarding the noise distribution. Specifically, target detection and classification utilizing electromagnetic induction sensors is considered.
Objectivity Is Not Neutrality: Explanatory Schemes in History

In Objectivity Is Not Neutrality, Thomas L. Haskell argues for a moderate historicism that acknowledges the force of perspective and reaffirms the pluralistic practices of a liberal democratic society-even while upholding time-honored distinctions between fact and fiction, scholarship and propaganda, right and might. Haskell addresses questions that will interest philosophers and literary theorists no less than historians, exploring topics ranging from the productivity of slave labor to the cultural concomitants of capitalism, from John Stuart Mill's youthful "mental crisis" to the cognitive preconditions that set the stage for antislavery and other humanitarian reforms after 1750. He traces the surprisingly short history of the word responsibility, which turns out to be no older than the United States. He examines the reasons for the rising authority of professional experts in nineteenth-century America. And he wonders whether the epistemological radicalism of recent years leaves us with any adequate basis for justifying human rights-rights of academic freedom, for example, or the right not to be tortured. Written by a thoughtful critic of the historical profession, Objectivity Is Not Neutrality calls upon historians to think deeply about the nature of historical explanation and to acknowledge more fully than ever before the theoretical dimension of their work.
Performance of a Variable Speed Constant Frequency Electrical System

This paper presents and discusses the performance data obtained in testing a 30 KVA aircraft generating system of the variable speed constant frequency (VSCF) type. The observed test results are compared with typical data from more conventional generating systems employing hydraulic constant speed drives and constant speed generators. Areas of performance such as voltage and frequency control, dc voltage content, voltage and frequency modulation and parallel operation of VSCF systems are emphasized.
Localization and Tracking of Single RNA Polymerase Molecules in Live E. Coli

Superresolution fluorescence microscopy locates and tracks the diffusive motion of single copies of RNA polymerase (RNAP) in live E. coli. On a timescale of 0.1-1.0 s, most RNAP copies separate remarkably cleanly into two states with comparable populations. The “slow” RNAPs move indistinguishably from DNA loci. We assign them to specifically bound copies that are initiating transcription, elongating, pausing, or awaiting termination. The “fast” RNAP copies act as a homogeneous population with Dfast = 0.2 μm2-s-1. These are assigned as a rapidly exchanging mixture of non-specifically bound copies and copies undergoing three-dimensional diffusion within the nucleoids. In longer trajectories of 7-s duration, we directly observe transitions between the slow and fast states, corroborating the assignments. In rapid growth conditions, for which transcription of stable RNA predominates over transcription of mRNA, the slow, transcribing RNAP copies preferentially locate at the periphery of the nucleoids, as do rrnG and RNAP “transcription foci”. The data provide strong evidence for transcription occurring at or very near the cytoplasmic membrane, supporting the transertion hypothesis of co-transcriptional translation of membrane proteins. We compare the partitioning of RNAP states inferred from single-particle tracking with different partitioning models from the literature.
On an open radiational boundary condition for weakly dispersive Tsunami waves

Abstract A radiational condition compatible with a weakly dispersive governing equation for tsunami waves is developed for use at the open lateral boundaries of a limited-domain propagation model. A Boussinesq-type governing equation for the interior is adopted. The resulting open boundary condition (OBC) is a modified Sommerfeld condition, in which the effects of weak dispersion, geometric spreading and shoaling are allowed. The OBC is applied along wave ray characteristics which intersect the open boundary obliquely. The numerical implementation employs Lagrange interpolations in two dimensions from information on a regular grid in the interior region. Test results indicate that the numerical boundary is highly transparent to incident waves in the absence of bottom topography. Weak dispersion effects (Airy dispersion, Poincare dispersion and nonlinear dispersion) are faithfully reproduced in the test simulations. The effects of topography (reflection, refraction, and diffraction), which are not included in the OBC, result in some contamination of the solutions. However, the first few leading waves are free from serious error. Also the contamination due to topography near the open boundaries is sporadic and does not produce a cumulative effect. The modified OBC is shown to be a very significant improvement over the simple nondispersive Sommerfeld radiation condition.
Dr. Furse's Lazy Professor's Guide to Teaching

This article presents a few suggestions for time-efficient exams, homework, and office hours that maintain educational quality while (hopefully) saving time for professors, and reducing stress for students.
Non-additive costs and interactions alter the competitive dynamics of co-occurring ecologically distinct plasmids.

Plasmids play an important role in shaping bacterial evolution and adaptation to heterogeneous environments. As modular genetic elements that are often conjugative, the selective pressures that act on plasmid-borne genes are distinct from those that act on the chromosome. Many bacteria are co-infected by multiple plasmids that impart niche-specific phenotypes. Thus, in addition to host–plasmid dynamics, interactions between co-infecting plasmids are likely to be important drivers of plasmid population dynamics, evolution and ecology. Agrobacterium tumefaciens is a facultative plant pathogen that commonly harbours two distinct megaplasmids. Virulence depends on the presence of the tumour-inducing (Ti) plasmid, with benefits that are primarily restricted to the disease environment. Here, we demonstrate that a second megaplasmid, the At plasmid, confers a competitive advantage in the rhizosphere. To assess the individual and interactive costs of these plasmids, we generated four isogenic derivatives: plasmidless, pAt only, pTi only and pAtpTi, and performed pairwise competitions under carbon-limiting conditions. These studies reveal a low cost to the virulence plasmid when outside of the disease environment, and a strikingly high cost to the At plasmid. In addition, the costs of pAt and pTi in the same host were significantly lower than predicted based on single plasmid costs, signifying the first demonstration of non-additivity between naturally occurring co-resident plasmids. Based on these empirically demonstrated costs and benefits, we developed a resource–consumer model to generate predictions about the frequencies of these genotypes in relevant environments, showing that non-additivity between co-residing plasmids allows for their stable coexistence across environments.
Vascular clearance of Borrelia burgdorferi in rats

Radiolabeled Borrelia burgdorferi, the etiologic agent of Lyme disease, injected intravenously into rats are cleared from the vasculature within 1 h of injection. One low passage isolate showed trafficking between the circulation and possibly the vessel walls for the first 2 h after injection. All strains used were resistant to the effects of normal and heat-inactivated rat serum. During the first 2 h after injection, B. burgdorferi can be visualized in, and recovered from, the platelet-rich plasma. B. burgdorferi can adhere to both human and rat platelets in in vitro assays, but an in vivo association with these cells was not apparent. Similarly, none of the strains of B. burgdorferi used induced platelet aggregation. Removal from the circulation into the organs was measured in perfused rats by polymerase chain reaction and autoradiography and in non-perfused rats by organ cultures. These organisms invade organs (heart, kidneys, bladder, liver, spleen, brain) within 1-6 h after injection. Invasion of organs occurred in an apparent random manner; a large amount of radiolabel but no live organisms was excreted in the urine during the first 24 h, suggesting degradation of the inoculum.
Synthesis of 2-[11C]methoxy-3,17β-O,O-bis(sulfamoyl)estradiol as a new potential PET agent for imaging of steroid sulfatase (STS) in cancers

Steroid sulfatase (STS) catalyzes the hydrolysis of steroid sulfates to estrones, the main source of estrogens in tumors. Carbonic anhydrase II (CAII) is highly expressed in red blood cells through a coordination of the monoanionic form of the sulfamate moiety to the zinc atom in the enzyme active site, and CAII is highly expressed in several tumors. 2-Methoxy-3,17β-O,O-bis(sulfamoyl)estradiol (5) is a dual-function STS-CAII inhibitor inhibited STS with 39 nM IC(50) value selectively over CAII with 379 nM IC(50) value. This compound exhibited potent antiproferative activity with mean graph midpoint value of 87 nM in the NCI 60-cell-line panel, and antiangiogenic in vitro and in vivo activity in an early-stage Lewis lung model as well. The compound has been recently developed as a multitargeted anticancer agent. Both STS and CAII are over-expressed in cancers and have become attractive targets for cancer treatment and molecular imaging of cancer. Here we report the first design and synthesis of 2-[(11)C]methoxy-3,17β-O,O-bis(sulfamoyl)estradiol ([(11)C]5) as a new potential imaging agent for biomedical imaging technique positron emission tomography (PET) to image STS in cancers. The authentic standard 5 was synthesized from 17β-estradiol by published procedures in 5 steps with 40% overall chemical yield. The precursor 2-hydroxy-3,17β-O,O-bis(sulfamoyl)estradiol (14a) for radiolabeling was synthesized from 17β-estradiol in 10 steps with 5% overall chemical yield. The target tracer [(11)C]5 was prepared from the precursor 14a with [(11)C]CH(3)OTf through O-[(11)C]methylation and isolated by HPLC combined with solid-phase extraction (SPE) purification in 40-50% radiochemical yields based on [(11)C]CO(2) and decay corrected to end of bombardment (EOB), with 370-740 GBq/μmol specific activity at EOB.
Biomarkers of risk stratification in congestive heart failure: North American view.

There is broad adoption of various cardiac and noncardiac biomarkers in clinical practices across North America for the diagnosis and management of heart failure. Like any clinical condition, there are several overall objectives in biomarker testing: to establish or refute a diagnosis of heart failure and/or cardiac dysfunction; to understand the underlying pathophysiologic processes that may warrant specific interventions; to determine the level of disease severity in a manner to triage medical decisions; to detect and potentially avoid adverse consequences as a result of therapeutic interventions; and to monitor responses to treatment. While at present no single biomarker can serve all of these objectives, the growing experience with cardiac-specific biomarkers, such as natriuretic peptide and cardiac troponin testing, has allowed clinicians to better identify those at heightened short- or long-term risk. It is clear that difficulty remains in translating research evidence into clinical practice. While ...
MUTATION IN CONTINUOUS CULTURES. I. DEPENDENCE OF MUTATIONAL RESPONSE UPON GROWTH-LIMITING FACTORS.

Abstract Rates of caffeine-induced mutation to resistance to bacteriophage T5 were measured in strains of E. coli B which were limited with one of several kinds of growth factors. A constant mutation rate was observed only when tryptophan-requiring cultures were limited in their supply of tryptophan. In all others mutation rate increased with increasing growth rate, and furthermore, mutation rate appears to be directly proportional to growth rate in all but one of these. Spontaneous mutation rates in glucose-limited cultures also appear proportional to growth rate. These findings suggest the existence of two different kinds of mutational response.
The long-term outcome of glaucoma filtration surgery.

Abstract PURPOSE: To determine the long-term outcome of glaucoma filtration surgery in preserving vision. Visual loss from progressive glaucomatous damage and from complications of surgery, both short and long term, were included. METHODS: A retrospective, community-based, longitudinal study of residents of Olmsted County, Minnesota, who were newly diagnosed with open-angle glaucoma between 1965 and 1980 and underwent filtration surgery in these or subsequent years through 1998. Intraocular pressure (IOP), visual acuity, visual fields, and progression to legal blindness were monitored. Kaplan-Meier analysis was used to determine the cumulative probabilities of changes in these parameters. RESULTS: 73 eyes of 49 patients underwent conventional filtration surgery. Analysis of the first eye having surgery revealed a mean preoperative IOP of 27.6 ± 8.5 mm dropping to 16.7 ± 5.6 mm at year one, and remaining in this range throughout follow-up (14.7 ± 3.0 mm at 10 years; with or without use of medications). The probability of progression to blindness was 46% at 10 years after surgery, as calculated by Kaplan-Meier analysis. Eyes going blind had a postoperative IOP equal to or lower than those not becoming blind (14.0 ± 4.4 vs. 15.4 ± 3.0 at postoperative year 10). Eyes going blind had more advanced field loss at the time of surgery, with scotomas above and below the horizontal axis, than eyes not going blind, which had scotomas in only one hemifield. Three patients developed late bleb leaks; two patients developed endophthalmitis. The probability of undergoing cataract surgery was 37% by 10 years postoperatively, which did not differ significantly from the cohort of patients not undergoing surgery at a comparable time point. CONCLUSIONS: Filtration surgery was associated with a 54% probability of preservation of vision from progression to legal blindness at 10 years after surgery. Patients becoming blind had more advanced field loss at the time of surgery; IOP was similar between those going blind and those retaining vision.
Wear of silicon carbide in high speed sliding

Abstract Attritious wear of silicon carbide rubbing against a cobalt base superalloy at high speed was studied using a scanning electron microscope (SEM) and an Auger electron spectroscope (AES). The SEM study of the wear area on the silicon carbide grain showed it to be very smooth. The AES study of the groove-like marking generated by a silicon carbide grain showed a heavy concentration of carbon in areas where submicron wear debris was present. No indication of chemical reaction of the abrasive with the work material was evident. Instead, it appears that the surface atoms on the abrasive are removed preferentially, layer by layer, by oxidation under high temperature and a favorably directed shear stress.
The enzymic deacetylation of the carcinogen 2-acetylaminofluorene and related compounds

Abstract The deacetylase activity of various tissue extracts toward the carcinogen 2-acetylaminofluorene and a number of related substrates has been studied by colorimetric and isotropic analytical methods. Mouse liver, rat liver, rat brain, kidney and heart were decreasingly active. Three transplantable rat tumors exhibited a low order of activity. Decreasing amounts of the substrates listed below were hydrolyzed by rat liver homogenates: Acetanilide, 2-acetylaminonaphthalene, 4-acetylaminofluorene, 2-acetylaminofluorene, 2-diacetylaminofluorene, 1-acetylaminofluorene, and 3-acetylaminofluorene. Ethyl alcohol and the surface active agents Tween 80, and Triton X-100 depressed the enzyme activity. The isotopic experiments showed that deacetylation was the only reaction occuring with the procedure employed. Radioactivity was bound to the liver proteins with indications that incorporation had taken place.
Effect of prenatally administered hypericum (St John's wort) on growth and physical maturation of mouse offspring.

Abstract Objective: Our purpose was to determine whether prenatal exposure to the herb hypericum (St John's wort) affects long-term growth and physical maturation of mouse offspring. Study Design: Forty CD-1 mice were randomly assigned to receive daily doses of either 180 mg/kg per day hypericum (n = 20) or a placebo (n = 20) for 2 weeks before conception and throughout gestation. Perinatal outcomes, growth, and physical milestones of the offspring were compared in a blinded manner. Variables were compared by analysis of variance or by χ 2 testing. Results: The gestational ages at delivery and litter sizes did not differ between the hypericum-exposed and the placebo-exposed offspring. The body weight, body length, and head circumference measurements from postnatal day 3 through adulthood increased in a manner that was indistinguishable between the two groups of offspring, regardless of gender. No differences in reaching physical milestones (teeth eruptions, eye opening, external genitalia) were noted between the 2 groups. The reproductive capability, perinatal outcomes, and growth and development of the second-generation offspring were unaffected by hypericum exposure. Conclusion: Maternal administration of hypericum before and throughout gestation did not affect long-term growth and physical maturation of exposed mouse offspring. (Am J Obstet Gynecol 2001;184:191-5.)
Degloving Combined with Structural Trauma at the Digital Level: Functional Coverage with Fascial Free Flaps

Major trauma to the digit that includes skin degloving and tendon loss, as well as fractures, nerve segmental loss, and devascularization can render that digit chronically painful, stiff, insensate, and a detriment to the overall function of the hand to the point that such digits may be candidates for ray resection. Large wounds may exceed the ability to achieve coverage by regional pedicle flaps. When the wound is restricted to the level of the digit, the narrow cylindrical shape and the ability to flex and fold make an absolute requirement for a very thin, as well as supple, flap a requirement that cutaneous free flaps cannot meet. This series reports on 12 male patients with major degloving and structural trauma at the digit level in which bone, tendon, and nerve reconstructions were covered with free fascial flaps and immediate split-thickness skin grafts, followed by early rehabilitation. All patients achieved sufficient functional recovery so that subsequent surgeries were not indicated.
Identification of an interferon-γ responsive element of a class II major histocompatibility gene in rat type 1 astrocytes

Interferon-gamma(IFN-gamma) has been shown to induce class II major histocompatibility complex (MHC) antigens on several cell types. Previous analysis of cell lines including a glioblastoma multiforme line by our laboratory has mapped an IFN-gamma-responsive element to the upstream - 141 to - 109 base pair (bp) region of the DRA promoter. Using deletion mutants, this report shows that this same general region (-135 to -109 bp) is important for IFN-gamma induction in two other human glioma lines and more importantly in primary astrocytes. We have confirmed that this regulatory region of the HLA-DRA gene is necessary for IFN-gamma inducibility in astrocytes using a substitution mutant. Sequences beyond -135 bp do not appear to have any additional positive or negative elements.
HoxA10 represses gene transcription in undifferentiated myeloid cells by interaction with histone deacetylase 2

The homeodomain proteins, HoxA10 and Pbx1a, interact with negative cis elements to repress gene transcription in undifferentiated myeloid cells. The CYBB and NCF2 genes, which encode the gp91PHOX and p67PHOX proteins, are two such HoxA10-Pbx1a target genes. In previous studies, we found that HoxA10-Pbx1a represses transcription of these genes by two mechanisms: competition for DNA binding with transcriptional activators and endogenous repression activity. In these studies, we identify a novel molecular mechanism of endogenous transcriptional repression by HoxA10-Pbx1a. Endogenous repression activity of other Hox-Pbx1a complexes requires recruitment of transcriptional co-repressor proteins by Pbx1a. In contrast, our investigations have determined that HoxA10 has Pbx1a-independent endogenous repression activity. We find that this transcriptional repression activity is abrogated by histone deacetylase inhibitors, suggesting involvement of co-repressor proteins. Consistent with this, we identify HoxA10 amino acids 224–249 as a Pbx1-independent repression domain, which interacts with histone deacetylase 2. We have determined that this HoxA10 domain is not conserved with other Abd Hox proteins, although homology exists with other transcription factors and co-repressors. Understanding the roles different Hox proteins play in myeloid differentiation is a challenging problem. Our results suggest that insight into this problem can be obtained from biochemical characterization of the various molecular mechanisms of Hox protein function.
Early detection of abdominal pregnancy by maternal serum AFP+ screening

We present two cases of abdominal pregnancy identified in our maternal serum screening programme-an additional, as yet unreported benefit of AFP + (multiple analyte) maternal serum oncofetal antigen screening in pregnancy
Homologous bladder augmentation in dog with the bladder acellular matrix graft.

Objective To determine the functional potential and antigenicity of the homologous bladder acellular matrix graft (BAMG) in a dog model. Materials and methods Seven mongrel dogs underwent partial cystectomy (20–50%) and grafting with an equal-sized BAMG; two control animals underwent partial cystectomy (40%) only. The dogs were killed after 30 (one), 120 (one) and 210 days (five dogs). Blood samples were obtained before and at 1, 2, 4, 7, 14, 30, 90 and 210 days after surgery. The dogs underwent cystography, intravenous pyelography and ultrasonography before and after surgery, and on the day they were killed, with cystoscopy carried out just before death. The grafted tissue was assessed using routine and immunohistochemical techniques. Results All the dogs survived surgery; a complete blood cell count, chemical panel and white blood cell count showed no significant difference between the experimental and control animals. Cystography, cystoscopy and ultrasonography revealed no pathological changes in the upper urinary tract. After 7 months, the mean bladder capacity in the augmented dogs was significantly higher (P = 0.035) than in the controls (264 vs 172 mL). Histological evaluation showed an invasion of all bladder wall components during the first month; at 7 months, the morphological examination showed essentially complete regeneration. Conclusion In this dog model, the potential of the BAMG as a bladder augmentation graft was confirmed, having minimal antigenicity with maximal acceptance. The reconstructed bladder matched the morphological and functional properties of the normal bladder.