cssi/SciSciGPT-SciSciNet huggingface dataset:
Urban drivers of plant-pollinator interactions

Summary Plant–pollinator interactions are affected by global change, with largely negative impacts on pollination and plant reproduction. Urban areas provide a unique and productive study system for understanding the impacts of many global change drivers on plant–pollinator interactions. We review the mechanistic pathways through which urban drivers alter plant–pollinator interactions. The literature on urban drivers of plant–pollinator interactions is small but growing and has already produced exciting insights about how population processes or pollinator behaviour interacts with landscape urban drivers to affect pollination outcomes. Habitat loss and fragmentation can change flower visitation rates and pollination success through changes in pollinator foraging behaviour or through population-level effects on pollinators. Urban environments, where impermeable surface provides an inhospitable matrix, may allow researchers to identify habitat fragments more clearly than in many other environments. Recent studies have found that non-native plants are not differently preferred by pollinators relative to native plants, therefore removing the basis for expecting pollinator-mediated competition between native and non-native plants in urban habitats. However, non-native species together with managed vegetation may have powerful effects in urban habitats via changes in community-level plant phenology and consequent changes in pollinator phenology. The current level of climate warming has not caused plants and pollinators to become detectably temporally separated, although at the same time, diversity among species’ phenological responses could buffer plant–pollinator interactions from climate variation. Due to the urban warming effect, cities provide a promising system for better understanding the warming effects on plant–pollinator interactions. Environmental contaminants such as soil nitrogen and heavy metal pollution have been examined with respect to plant–pollinator interactions in small-scale, mechanistic studies. The extent to which environmental contaminants drive plant–pollinator interactions in actual urban landscapes is, however, currently unknown. Important knowledge gaps that require research attention include understanding the consequences of plant and pollinator trait filtering on plant–pollinator interactions, and expanding the literature to include underrepresented biomes and pollinator taxa.
Mercury dynamics in a small Northern Minnesota lake: water to air exchange and photoreactions of mercury

Mercury speciation at a small seepage lake in Northern Minnesota was shown to be influenced by photoreduction and photooxidation. Fluxes of Hg0 from water to air were greatest in the warmer, sunnier months in 2001 to 2002; however, correlation with solar radiation was weak. The daytime evasional loss was generally from water to air and was estimated at 5.3 pmol m−2 h−1 for 2001 and 6.2 pmol m−2 h−1 for 2002 using a two-layer gas transfer model. Losses of Hg0(aq) in the dark over 10 days were observed in lake water (0.02 h−1), Milli-Q™ water, and HPLC grade water (0.002 h−1) and agreed with reported pseudo-first-order loss rates in the dark in other freshwaters. Using a mercury arc lamp, the pseudo-first-order loss rate of Hg0 in water from Spring Lake was found to range from 0.39 to 0.76 h−1. Other sinks for Hg0 exist through reaction with ozone, hydroxyl radical, and possibly singlet oxygen. A second-order reaction rate constant for Hg0(aq) and OH of 1.0×109 M−1 s−1 was estimated based on data from experiments and the literature. Although less reactive, there is a higher steady state concentration of ozone in lake water compared to hydroxyl radical. Consequently, loss of Hg0(aq) by ozone may predominate. Potential oxidation of Hg0(aq) by singlet oxygen using rose bengal as a sensitizer could not distinguish between oxidation by rose bengal and by singlet oxygen itself. Chloride enhanced the oxidation of Hg0(aq) and should be considered in the mercury cycle in the ocean.
VEGFA activates erythropoietin receptor and enhances VEGFR2-mediated pathological angiogenesis.

Clinical and animal studies implicate erythropoietin (EPO) and EPO receptor (EPOR) signaling in angiogenesis. In the eye, EPO is involved in both physiological and pathological angiogenesis in the retina. We hypothesized that EPOR signaling is important in pathological angiogenesis and tested this hypothesis using a rat model of oxygen-induced retinopathy that is representative of human retinopathy of prematurity. We first determined that EPOR expression and activation were increased and that activated EPOR was localized to retinal vascular endothelial cells (ECs) in retinas at postnatal day 18 (p18), when pathological angiogenesis in the form of intravitreal neovascularization occurred. In human retinal microvascular ECs, EPOR was up-regulated and activated by VEGF. Lentiviral-delivered shRNAs that knocked down Muller cell–expressed VEGF in the retinopathy of prematurity model also reduced phosphorylated EPOR (p-EPOR) and VEGFR2 (p-VEGFR2) in retinal ECs. In human retinal microvascular ECs, VEGFR2-activated EPOR caused an interaction between p-EPOR and p-VEGFR2; knockdown of EPOR by siRNA transfection reduced VEGF-induced EC proliferation in association with reduced p-VEGFR2 and p-STAT3; however, inhibition of VEGFR2 activation by siRNA transfection or semaxanib (SU5416) abolished VEGFA-induced proliferation of ECs and phosphorylation of VEGFR2, EPOR, and STAT3. Our results show that VEGFA-induced p-VEGFR2 activates EPOR and causes an interaction between p-EPOR and p-VEGFR2 to enhance VEGFA-induced EC proliferation by exacerbating STAT3 activation, leading to pathological angiogenesis.
EFFECTS OF INDUCED SOCIAL ROLES ON THE HIGH SCHOOL PERSONALITY QUESTIONNAIRE

A one-way multivariate analysis of variance design with a control group (regular directions) and three treatment groups using induced social roles (Faking Good, Teacher, and Ideal Teacher) as independent variables and the High School Personality Questionnaire primary scores as dependent variables was used. Subjects were 384 male high school students from Grades 9 through 12. Within each classroom, students were randomly assigned to the four groups noted above. A broad pattern of differences in scores on primary and secondary personality dimensions were obtained. Significant differences between the control (standard directions) and the Faking Good, Teacher, and Ideal Teacher roles were obtained on three secondary and most of the primary personality dimensions. In several cases the ideal social role and neutral social role showed distinct differences from the more pervasive favorable impression role.
A novel self-aligned isolation process for VLSI

We have developed a novel NMOS process for VLSI isolation. The process employs an RIE of the field oxide followed by a metal liftoff and a high-energy boron sheet implant. The energy of the implant and the metal thickness are selected such that the boron penetrates the field oxide, but not the metal. Performing the isolation doping after growing the field oxide eliminates encroachment of the isolation doping into the channel end while simultaneously providing a self-aligned channel stop. The doping concentration in the channel region is determined by implants that are independent of the doping concentration in the channel stop area. With this technique, we have obtained excellent device performance as well as rigorous device isolation. Even at the isolation spacing of 0.7 µm, there was <1-pA leakage at 5 V. The active devices exhibit minimal body effect coefficients (0.1-0.2), good subthreshold behavior (80 mV/DEC), and low junction capacitance. The experimental data is confirmed by two-dimensional analysis.
Assessment of a role for phospholipase A2 and arachidonic acid metabolism in human lymphocyte natural cytotoxicity.

Abstract The reagents quinacrine, hydrocortisone, and dexamethasone have been assumed to affect phospholipase A 2 (PA 2 ) when they reduce natural killer (NK) activity. However, these reagents did not reduce lymphocyte incorporation of [ l4 C]arachidonate, which implies that they are not acting as PA 2 inhibitors in this lymphocyte system. However, p -bromophenacyl bromide (BPB), which is an active site inhibitor of PA 2 , irreversibly abrogated NK activity of pretreated lymphocytes, disrupted target cell binding, and reduced [ 14 C]arachidonic acid incorporation by 70–80% as compared to controls. Other observations contrary to expectations for PA 2 inhibitors were: (1) quinacrine inhibited NK lysis when lymphocytes were pretreated and (2) the glucocorticoids only inhibited NK activity when continuously present in the assay. Furthermore, NK inhibition by hydrocortisone did not require protein synthesis. The lipoxygenase inhibitors, nordihydro-guaiaretic acid (NDGA), 5,8,11,14-eicosotetraynoic acid (ETYA), and hydroxyphenylretinamide, and not cycloxygenase inhibitors, reduced NK activity. These data suggest that arachidonate must be metabolized through the 5-lipoxygenase pathway in order to function in NK.
Temporary paralysis of cranial nerves III, IV, and VI after a Gow-Gates injection

Correct use of the Gow-Gates injection consistently produces area-specific mandibular anesthesia. Although high success rates and significant advantages have been reported for this technique, it is not without complications. A case report featuring temporary paralysis after a Gow-Gates injection is followed by discussion.
Kinetics of the substitution reaction of thiocyanate with tetrakis(3-N-methylpyridyl)porphinecobalt(III)

The equilibrium constant for the first thiocyanate addition to Co(III)-tetra(3-N-methylpyridyl)porphine is a factor of two smaller than for the less basic 4-N-methylporphine isomer. This effect is primarily due to a larger Co-SCN dissociation rate constant for the 3-isomer.
Red cell metabolism in the newborn infant

Studies were undertaken to define further the extent of oxidant-induced injury and the degree to which it was repairable in the red cells of the newborn infant. Red cells from both infants and adults were incubated in the presence of either acetylphenhydrazine or menadione with and without glucose. Glucose deprivation produced irreversible loss of red cell hexokinase and glyceraldehyde-3-phosphate dehydrogenase activity in the cells, which lost the capacity to consume glucose at a normal rate. Menadione, even in the presence of glucose, inhibited fatty acid incorporation into the membrane of the infant's erythrocytes, but stimulated uptake in the cells of adults. The intracellular metabolic alterations produced by the oxidants were reduced by pretreatment of the cells with carbon monoxide, suggesting that hydrogen peroxide generation with inadequate detoxification was responsible for the injury observed in the erythrocytes of the neonate.
Optimized Strategies for Smart Nuclear Search

In many applications the time available for nuclear materials detection is short, the signals are weak, and the backgrounds are large, variable, and difficult to control. We develop optimal strategies for nuclear search in these difficult conditions, and demonstrate these strategies in experiments. Model-driven algorithms promise to reduce search time by order of magnitude, with increased reliability of detection and reduced number of false positives. These strategies can be applied to various nuclear search scenarios, for both mobile and stationary detectors, hand-held detectors and sensors on robotic platforms. Our methods can be used against nuclear smugglers and terrorists, for safeguards and non-proliferation treaty monitoring, as well as in other situations where radioactive sources need to be found.
Trends in Health Care Utilization by HIV-infected Children at Yale-New Haven Hospital, 1981-1996 540

Trends in Health Care Utilization by HIV-infected Children at Yale-New Haven Hospital, 1981-1996 540
REVIEW OF THE FINITE-ELEMENT METHOD FOR THREE-DIMENSIONAL ELECTROMAGNETIC SCATTERING

We review the finite-element method for three-dimensional scattering. A feature of this study is the construction of the weak form of the wave equation for dielectric volumes encompassing impedance and resistive surfaces, thus avoiding the introduction of a variational functional. Formulations based on absorbing boundary conditions, and the boundary integral equation for truncating the mesh, are described, and their corresponding discretization schemes are discussed. We place emphasis on large-scale simulations and solution schemes for achieving low memory requirements and code performance on parallel computing architectures. The results that we present demonstrate the robustness and the versatility of the method for large-scale computations.
Helix nucleation kinetics from molecular simulations in explicit solvent.

We study the reversible folding/unfolding of short Ala and Gly-based peptides by molecular dynamics simulations of all-atom models in explicit water solvent. A kinetic analysis shows that the formation of a first α-helical turn occurs within 0.1–1 ns, in agreement with the analyses of laser temperature jump experiments. The unfolding times exhibit Arrhenius temperature dependence. For a rapidly nucleating all-Ala peptide, the helix nucleation time depends only weakly on temperature. For a peptide with enthalpically competing turn-like structures, helix nucleation exhibits an Arrhenius temperature dependence, corresponding to the unfolding of enthalpic traps in the coil ensemble. An analysis of structures in a “transition-state ensemble” shows that helix-to-coil transitions occur predominantly through breaking of hydrogen bonds at the helix ends, particularly at the C-terminus. The temperature dependence of the transition-state ensemble and the corresponding folding/unfolding pathways illustrate that folding mechanisms can change with temperature, possibly complicating the interpretation of high-temperature unfolding simulations. The timescale of helix formation is an essential factor in molecular models of protein folding. The rapid helix nucleation observed here suggests that transient helices form early in the folding event. Proteins 2001;42:77–84. © 2000 Wiley-Liss, Inc.
Cardiovascular reactivity as behavior

Abstract The word, behavior, means action or reaction. Thus, all physiologic responses meet this definition and are behavior. Furthermore, if the response is neurally mediated, then there are only 3 possible behavioral mechanisms that can be operating to determine it: (1) The response is part of a reflex, elicited by an adequate stimulus. In this case, in an intact animal the expression of the response will be modulated by a variety of situational factors. (2) The response is part of a reflex. However, the capacity of the stimulus to elicit the response is acquired through association with an adequate stimulus. Thus, the reflex is learned rather than innate. (3) The response is part of a “central command” and is emitted in anticipation of a consequence whose likelihood of occurrence has been learned. Neurally mediated responses of the circulation meet all these criteria. Thus, circulatory responses not only are passive reflexes, they also are reactive and proactive behaviors, which permit animals to interact effectively with their environments, and which change with practice. These principles explain a variety of cardiovascular effects observed in experimental or clinical settings. Furthermore, by applying well-established behavioral principles to circulatory responses, it is possible to achieve clinically significant effects. This presentation will characterize the way in which behavioral mechanisms are expressed in the circulation, it will describe a number of clinically significant findings that illustrate the importance of these mechanisms, and it will propose a number of applications of behavioral principles that can be used in clinical practice.
Recipe for a new imaging biomarker: carefully combine target, reagent, and technology

A careful combination of biological targeting moieties (C3 fragments), imaging reagents (a small particle of iron oxide), and appropriate technology (T2-weighted magnetic resonance imaging) is the key to the successful development of an imaging agent for glomerulonephritis. This recipe applies to virtually any molecular imaging probe for the kidney and throughout the body. However, each organ and disease requires a unique combination of these three components in order to achieve success.
Purification of a 3S cytosol androgen receptor from rat prostate that stimulates DNA-dependent RNA synthesis in vitro.

Summary A 3S androgen-binding protein has been purified from a crude 8S cytosol fraction of rat prostate to electrophoretic homogeneity by selective binding to prostate DNA. The receptor activity of this androgen-binding 3S protein was assessed by its tissue-specific transfer of bound androgen to prostate nuclei. The androgen-receptor complex was capable of stimulating DNA-dependent RNA synthesis in vitro in a nucleoplasmic RNA polymerase reaction.
Appearance-Related Social Comparisons: The Role of Contingent Self-Esteem and Self-Perceptions of Attractiveness:

Two studies examined contingent self-esteem (CSE) and responses to appearance-related social comparisons. Study 1 was an experimental study in which women rated a series of advertisements from popular women's magazines. Study 2 employed an event-contingent diary recording procedure. In Study 1, women who were higher in CSE and lower in self-perceptions of attractiveness (SPA) experienced greater decreases in positive affect and greater increases in negative affect following the ad-rating task. Study 2 results supported a mediation model in which women who were higher in CSE felt worse after social comparisons because they made primarily upward comparisons. Overall, results suggest that appearance-related comparisons are more distressing for those who base their self-worth on contingencies and have lower self-perceived attractiveness.
Role of prostaglandins and angiotensin II in experimental glomerulonephritis

Role of prostaglandins and angiotensin II in experimental glomerulonephritis. Moderate autologous nephrotoxic serum nephritis (NSN) in rats causes no reduction in GFR despite a reduction in ultrafiltration coefficient (K f ) to less than one-half of normal. An increase in intraglomerular hydraulic pressure maintains GFR, but the signal and efferent mechanisms for this adaptation remain unknown Indomethacin and saralasin were used to study the possible roles of prostaglandins and angiotensin II (A-II) in the adaptation to NSN. Indomethacin decreased renal blood flow (RBF) in NSN (- 8.6%, P 2 excretion decreased markedly both in NSN and controls. With combined treatment using indomethacin and saralasin, RBF increased in NSN (+ 22.4%, P 2 excretion was increased in NSN compared to controls, decreased markedly in NSN after either indomethacin or saralasin infusion. These findings indicate an increased action of angiotensin II in NSN, and, in addition, provide evidence for increased action of vasodilator prostaglandins, perhaps secondary to enhanced angiotensin II action. These results point to an enhanced intrarenal action of angiotensin II in NSN.
Potentiated cytotoxicity of glycolytic inhibitors by phenethylbiguanide in cell culture.

SummaryCultured cells exposed to phenethylbiguanide and other respiratory inhibitors or uncouplers of phosphorylation exhibited an increased susceptibility to cytotoxicity of certain inhibitors of glycolysis.
An error estimate in the EFG method

In this paper, local and global error estimates for the element-free Galerkin (EFG) method are proposed. The essence of proposed error estimates is to use the difference between the values of the projected stress and these given directly by the EFG solution. The stress projection can be obtained simply by taking product of shape function based on a different domain of influence with the stresses at nodes. In this study, it was found that the effectivity index is optimized if the domain of influence in stress projection procedure is the smallest that retains regularity of the matrices in EFG. Numerical tests are shown for various 1D and 2D examples illustrating the good effectiveness of the proposed error estimator in the global energy norm and in the local error estimates.
Developing Active Citizens: Community Service Learning in Social Studies Teacher Education

(1995). Developing Active Citizens: Community Service Learning in Social Studies Teacher Education. The Social Studies: Vol. 86, No. 3, pp. 122-128.
Sensitivity of papilledema as a sign of shunt failure in children.

Purpose Papilledema is considered one of the cardinal ophthalmologic signs of shunt failure. However, the prevalence of papilledema in children with shunt malfunction has not been systematically investigated. The purpose of this study is to determine the sensitivity of papilledema as a sign of shunt failure in children. Methods A prospective evaluation was undertaken of all children (n = 29; Results Twenty-nine patients had surgically confirmed shunt failure. Patient's age ranged from 36 days to 18 years, 8 months. Four patients (14%) had papilledema, and 1 patient had severe optic disk pallor. The remaining 24 patients had flat optic disks. Five patients had flat optic disks despite an intracranial pressure ≥300 mm H 2 O. Conclusions Papilledema is not a sensitive sign of shunt failure. Even children with severe elevations in intracranial pressure from shunt malfunction may have flat optic disks. Therefore, physicians that evaluate children with shunts should be aware that a normal optic disk does not preclude shunt malfunction.
CELL DIVISION: EFFECTS OF PRESSURE ON THE MITOTIC MECHANISMS OF MARINE EGGS (ARBACIA PUNCTULATA).

Abstract Mitotic apparatus (spindle—aster—chromosome complexes) were isolated from the eggs of Arbacia punctulata immediately subsequent to an exposure to high pressure (2000–10,000 psi) applied at various stages in first cleavage. The isolation procedure consisted of selective solubilization with digitonin after treatment with cold 35 per cent ethanol. Pressure treatments of appropriate intensity and duration effected a drastic disorganization of the linear and radial structure of the spindle-aster complex and an irregular clumping of the chromosomes. One minute of compression at 10,000 psi sufficed to abolish all traces of fibrous structure and to cause a clumping of the chromosomes near the center of the spindle remnant. At lower pressures, however, longer treatments were required to produce an equivalent degree of disorganization, namely: 3–4 min at 8000; 5–6 min at 6000. At 2000 psi, an apparently normal structural configuration persisted but chromosomal displacement was definitely retarded. Virtually no chromosomal displacement was observed at or above the 4000 psi level. Post-compression recovery, as judged by a study of isolations fixed at various times after treatment, is longer with more drastic degrees of disorganization. An intimate relationship was found between structural recovery and the resumption of functional activity. Presumably the observed disorganization of the spindle and asters results from a pressure-induced solation of these intracellular gel structures. Some of the evidence indicates that the mid-region of the anaphase spindle is especially susceptible to such solation.
Mechanics of the implosion of cylindrical shells in a confining tube

Abstract A fundamental experimental investigation, with corresponding computational simulations, was conducted to understand the physical mechanisms of implosions of cylindrical shells occurring within a tubular confining space which has a limited potential energy reservoir. In particular, attention was focused on studying the generation of pressure waves from the implosion, the interaction of the pressure waves with the confining tube walls and end caps, and the collapse mechanisms of the implodable volume. Experiments were conducted with three implodable volume geometries which had similar critical collapse pressures. The implodable volumes were aluminum 6061-T6 cylindrical tubing and were placed concentrically within the confining tube. Pressure histories recorded along the length of the confining tube during the experiments were utilized to analytically evaluate the deformation of the implodable volume using fluid–structure coupled deformation models. Computational simulations were conducted using a coupled Eulerian–Lagrangian scheme to explicitly model the implosion process of the tubes along with the resulting compressible fluid flow. The numerical model developed in this study is shown to have high correlation with the experimental results and will serve as a predictive tool for the simulation of the implosion of different cylindrical geometries as well as various tube-in-tube implosion configurations. The experimental results show that the limited hydrostatic potential energy available in a confined environment, as compared to a free field, significantly influences the implosion process. The wall velocities of the implodable volume during the collapse, as well as the extent of the collapse progression, are largely affected by the sudden decrease in the available hydrostatic potential energy. This energy is shown to be partially transformed into elasto-plastic strain energy absorbed in the deformation of the implodable volume, as well as the kinetic energy of the water during the implosion process. Experiments also show that the extent of the collapse progression of an implodable volume can potentially be inhibited within a closed environment, which can lead to the arresting of an implosion event prior to completion for larger implodable volumes. The pressure waves generated during collapse comprise of waves emitted due to the impact of the implodable volume walls, the arrest of rushing water and contact propagation along the walls. These processes later evolve into water hammer type axial wave behavior.
Effect of administered human growth hormone on growth retardation in inflammatory bowel disease.

In a previous study of 22 severely growth-retarded children with inflammatory bowel disease (IBD), endocrinologic evaluation revealed hypogonadism and low growth hormone (HGH) levels. This was attributed to a secondary hypopituitarism. In order to assess this hypothesis, two individuals from this group and another similar child who was not so severely growth-retarded as to be included in the initial study were given HGH replacement in an acute trial and for a 6-month interval. No significant height increment could be attributed to the HGH administration although a definite anabolic response was present in each patient during the acute trial. It appears that the youngsters with IBD may have a relative end-organ resistance to the metabolic and growth-promoting effects of HGH and that their growth problems are not related to hypopituitarism.
Application of Spinal Ablative Techniques for the Treatment of Benign Chronic Painful Conditions: History, Methods, and Outcomes

Study Design. The literature on current neuroablative techniques for treating benign chronic painful conditions is comprehensively reviewed. Objective. To provide the reader with an understanding of the indications, techniques, and outcomes for the various ablative procedures used to treat chronic pain syndromes. of Background Data. Neuromodulatory techniques are rapidly suppianting the traditional neuroablative procedures used to treat many types of pain. Methods. A MEDLINE search was conducted for each of the following procedures: radiofrequency facet denervation, cordotomy, myelotomy, sympathectomy, DREZ-otomy, rhizotomy, and ganglionectomy. In the review of each article, special attention given to the outcome, length of follow-up, complications, and number of petients. Summaries of this data were compiled to provided historical perspective, current techniques, indications, and outcomes for each of the aforementioned procedures. The outcomes cited for each procedure generally represent the data from the three or four largest series with adequate follow-up length. Results. The aforementioned procedures have 30% to 90% success rates, with success defined as at least a 50% reduction in perceived pain. These results tend to diminish with time. However, most are assoclated with a significant degree of morbidity and relatively high complication rates. In addition, many of the ttechniques lead to deafferentation pain syndromes. Conclusions. Ablative spinal techniques offer pain relief for many patients, but the use of these methods should be considered carefully in the light of available nondestructive procedures that may achieve similar goals with potentially lower morbidities.
A “frustration effect” following electric shock

Abstract The effects of nonreward, punishment by mild electric shock, and their combination were compared in an Amsel double-alleyway situation. Rats ran faster following either nonreward, punishment with shock, or both combined than they did folowing reward alone. There were no differences in the magnitude of these effects. These results extend the empirical evidence for the assertion that mild aversive stimuli such as electric shock and nonreward often yield equivalent behavioral effects. They also suggest that increased vigor in the performance of behavior following nonreward, heretofore termed a “frustration effect,” might be best considered a subset of a more general phenomenon: either escape behavior superimposed upon food motivated behavior, or an “excitatory effect” resulting from mild aversive stimulation.
Independent Christian Day Schools: Past, Present, and Prognosis.

Carper and Layman trace the development of the Protestant day-school movement. They examine its present-day status as a rapidly growing phenomenon in American education. Then they delineate some of the issues that must be addressed if such schools are to successfully negotiate the perilous path towards excellence.
Integral averaging and bifurcation

One of the simplest topological variations of the phase space of a one-parameter family of differential equations (vector fields, flows) is the creation of periodic orbits from equilibria as the parameter crosses a critical value. The study of such topological variations about an equilibrium was initiated and developed by Poincare perhaps 90 years ago and belongs today to the classical theory of periodic solutions. It was Hopf [23] who presented the bifurcation theorem in 1942 and it is now commonly known as the Hopf bifurcation theorem. Specifically, consider a one-parameter family of ODE (ordinary differential equations)
The clinical estimation of pulmonary hypertension accompanying mitral stenosis.

Abstract Forty patients having rheumatic heart disease and mitral stenosis were studied clinically and by cardiac venous catheterization in an attempt to develop clinical criteria for the estimation of the degree of pulmonary hypertension. The patients were divided into three groups according to the mean pulmonary arterial blood pressure: mild or no pulmonary hypertension, below 30 mm. Hg; moderate pulmonary hypertension, 30 to 49 mm. Hg; severe pulmonary hypertension, above 50 mm. Hg. Eighteen subjects were in the mild group; ten were moderate; twelve were severe. The following criteria were evaluated: 1.1. The height of the "A" wave of the right atrial pressure pulse. This was of no help in this group. 2.2. Roentgen evidence of right ventricular hypertrophy. This usually indicated rather severe pulmonary hypertension when marked, if the transverse diameter of the heart was not greatly increased. 3.3. Precordial Lead V 1 of the electrocardiogram was very helpful in evaluating the degree of pulmonary hypertension. In general, evidence of right ventricular hypertrophy was not found with mean pulmonary arterial pressures below 28 mm. Hg and was consistently present with mean pulmonary pressures of 42 mm. Hg or above ∗ ∗Since the writing of this paper, electrocardiographic evidence of right ventricular hypertrophy was found in one patient with mitral stenosis and a mean pulmonary arterial pressure of 21 mm. Hg; another patient with mitral stenosis had a mean pulmonary arterial pressure of 52 mm. Hg and no evidence of right ventricular hypertrophy in Lead V 1 .. 4.4. The intensity of the apical diastolic murmur was of no help in evaluating pulmonary hypertension. Intense apical murmurs and thrills were often associated with mild pulmonary hypertension and only moderate mitral stenosis. 5.5. The intensity of the pulmonic second sound was of no help. Severe pulmonary hypertension was often associated with only slight or moderate accentuation of the sound. 6.6. Hemoptysis was more frequent in severe pulmonary hypertension but was observed at all pressure levels. 7.7. Right heart failure was almost constant in the severe group. It was usually absent in the mild group unless associated with an increase in the transverse diameter of the heart. 8.8. Pulmonary edema was not seen with pulmonary arterial mean pressures below 26 mm. Hg but was often absent at higher pressure levels.
Plasma-derived MHC class II+ exosomes from tumor-bearing mice suppress tumor antigen-specific immune responses.

Tumor-specific immunosuppression is frequently observed in tumor-bearing hosts. Exosomes are nano-sized, endosomal-derived membrane vesicles secreted by most tumor and hematopoietic cells and have been shown to actively participate in immune regulation. We previously demonstrated that antigen-specific immunosuppressive exosomes could be isolated from the blood plasma of antigen-immunized mice. Here, we demonstrate that plasma-derived exosomes isolated from mice bearing OVA-expressing tumors were able to suppress OVA-specific immune responses in a mouse delayed-type hypersensitivity model. Enrichment of tumor-derived exosomes in the plasma of mice bearing subcutaneous melanoma was not detected using an exosome-tagging approach. Instead, depletion of MHC class II+ vesicles from plasma-derived exosomes or using plasma-derived exosomes isolated from MHC class II-deficient mice resulted in significant abrogation of the suppressive effect. These results demonstrate that circulating host-derived, MHC class II+ exosomes in tumor-bearing hosts are able to suppress the immune response specific to tumor antigens.
Studies of oxide supported metal clusters

The metal cluster carbonyl compounds, Rh6(CO)16 and [Pt3(CO)6] (n = 5,6) have been deposited from solution onto alumina and silica supports. Exposure to air results in decarbonylation of the surface supported compounds in each case. Gas adsoprtion and IR measurements for the alumina supported rhodium material indicate a unique and interesting chemistry in which CO and oxygen react with a surface species to form CO2 and the surface rhodium material is reversibly converted from a fully carbonylated form [apparently Rh6(CO)16] to a fully oxygenated (decarbonylated) form which may retain the Rh6 cluster integrity. The supported platinum complexes displayed a more conventional chemistry. After deposition on alumina or silica they could be decarbonylated in air. Exposure to CO failed to regenerate the starting material, but behaviour consistent with that reported for conventional reduced Pt on alumina or silica was observed.
Extracellular ATP induces intracellular alpha-synuclein accumulation via P2X1 receptor-mediated lysosomal dysfunction

The pathologic hallmark of Parkinson’s disease (PD) is the accumulation of alpha-synuclein (asyn) in susceptible neurons in the form of Lewy bodies and Lewy neurites. The etiology of PD remains unclear. Because brain injury has been suggested to facilitate asyn aggregation, we investigated whether cellular breakdown products from damaged cells can act on neighboring healthy cells and cause intracellular asyn accumulation and/or aggregation. Using 2 neuronal cell models, we found that extracellular adenosine triphosphate (ATP) induced a significant increase in intracellular asyn levels between 24 and 48 hours after treatment. Further investigation revealed that the observed asyn accumulation is a result of lysosome dysfunction caused by extracellular ATP-induced elevation of lysosomal pH. Interestingly, P2X1 receptor appears to mediate the cells’ response to extracellular ATP. Although Ca 2þ influx via P2X1 receptor is necessary for asyn accumulation, Ca 2þ influx per se is not sufficient for increased asyn accumulation. These findings provide new insight into our knowledge of the role of P2X receptors in PD pathogenesis and may be helpful in identifying new therapeutic targets for PD.
Cross-Cell DoF Distribution: Combating Channel Hardening Effect in Multi-Cell MU-MIMO Networks

Equipped with the multi-user MIMO (MU-MIMO) technology, a WiFi access point (AP) with M antennas can achieve M degrees-of-freedom (DoF) in theory. Existing MU-MIMO protocols strive to maximize DoF usage by serving M users simultaneously. In this paper, through a MU-MIMO testbed measurement, we found that the correlation between users' channels can severely compromise network throughput under a DoF-maximizing strategy. To combat this problem, we propose Kardia that judiciously distributes the DoF to least-correlated users within an AP's cell, and coordinates neighboring APs such that each can serve the best set of users while nulling mutual interference. The key challenge in Kardia lies in efficiently determining which set of users to serve without knowing the channel state from all of them. We propose a lightweight mechanism that enables APs to collaboratively infer the correlation between users through precoded probing packets. Our analysis shows that Kardia's DoF distribution framework has a provable performance guarantee. Our testbed implementation further reveals that Kardia can significantly boost the performance of multi-cell MU-MIMO networks, in contrast to legacy protocols like 802.11ac.
Obtaining antisera against growth hormone by immunizing rabbits with microdoses of the antigen

The authors describe a method for obtaining antisera in response to a highly purified preparation of growth hormone, free of additional antibody impurities. A high antiserum titer is obtained as a result of two-three subcutaneous injections of the antigen (microdoses) into all the rabbit extremities, in the area of the axillary and inguinal lymph nodes.
Characterization of statistical prior image constrained compressed sensing (PICCS): II. Application to dose reduction.

Purpose: The ionizing radiation imparted to patients during computed tomography exams is raising concerns. This paper studies the performance of a scheme called dose reduction using prior image constrained compressed sensing (DR-PICCS). The purpose of this study is to characterize the effects of a statistical model of x-ray detection in the DR-PICCS framework and its impact on spatial resolution. Methods: Both numerical simulations with known ground truth andin vivo animal dataset were used in this study. In numerical simulations, a phantom was simulated with Poisson noise and with varying levels of eccentricity. Both the conventional filtered backprojection (FBP) and the PICCS algorithms were used to reconstruct images. In PICCS reconstructions, the prior image was generated using two different denoising methods: a simple Gaussian blur and a more advanced diffusion filter. Due to the lack of shift-invariance in nonlinear image reconstruction such as the one studied in this paper, the concept of local spatial resolution was used to study the sharpness of a reconstructed image. Specifically, a directional metric of image sharpness, the so-called pseudopoint spread function (pseudo-PSF), was employed to investigate local spatial resolution. Results: In the numerical studies, the pseudo-PSF was reduced from twice the voxel width in the prior image down to less than 1.1 times the voxel width in DR-PICCS reconstructions when the statistical model was not included. At the same noise level, when statistical weighting was used, the pseudo-PSF width in DR-PICCS reconstructed images varied between 1.5 and 0.75 times the voxel width depending on the direction along which it was measured. However, this anisotropy was largely eliminated when the prior image was generated using diffusion filtering; the pseudo-PSF width was reduced to below one voxel width in that case. In thein vivo study, a fourfold improvement in CNR was achieved while qualitatively maintaining sharpness; images also had a qualitatively more uniform noise spatial distribution when including a statistical model. Conclusions: DR-PICCS enables to reconstruct CT images with lower noise than FBP and the loss of spatial resolution can be mitigated to a large extent. The introduction of statistical modeling in DR-PICCS may improve some noise characteristics, but it also leads to anisotropic spatial resolution properties. A denoising method, such as the directional diffusion filtering, has been demonstrated to reduce anisotropy in spatial resolution effectively when it was combined with DR-PICCS with statistical modeling.
Is there a new biosynthetic pathway for lung surfactant phosphatidylcholine

Abstract A critical appraisal of the literature on lung surfactant phosphatidylcholine synthesis suggests that the known cytidine and deacylation-reacylation pathways cannot quantitatively account for the synthesis of dipalmitoyl-phosphatidylcholine. The data, however, are consistent with a newly-proposed acyl-specific pathway, which would branch from the cytidine pathway at the point of CDPcholine, to form de novo glycerphosphorylcholine which would then be acylated specifically to form the final dipalmitoyl-phosphatidylcholine. Predictions unique to the new pathway are proposed for further testing.
Classifier systems that learn internal world models

Most classifier systems learn a collection of stimulus-response rules, each of which directly acts on the problem-solving environment and accrues strength proportional to the overt reward expected from the behavioral sequences in which the rule participates. gofer is an example of a classifier system that builds an internal model of its environment, using rules to represent objects, goals, and relationships. The model is used to direct behavior, and learning is triggered whenever the model proves to be an inadequate basis for generating behavior in a given situation. This means that overt external rewards are not necessarily the only or the most useful source of feedback for inductive change. gofer is tested in a simple two-dimensional world where it learns to locate food and avoid noxious stimulation.
US Interests and the Use of Force in the Middle East

Many aspects of US relations in the region of the Middle East compete for attention. Recently, the focus has been on US policy towards twin subjects of gripping interest: terrorism and Iran. But at...
High-field EMR: Recent CW developments at 25 tesla, and next-millennium challenges

After a brief review of the motivations to perform electron magnetic resonance at very high-field/high-frequency (VHF-EMR), we describe the spectrometers operational at the National High Magnetic Field Laboratory (NHMFL), Tallahassee, Florida: a 17 and a 25 Tesla instrument. We present measurements performed with the 25 Tesla machine that can operate up to 700 GHz for ag-Lande factor = 2 system. First we document the need of VHF-EMR to resolve all the three components of the g-tensor and thus better characterize the electronic structure of radicals involved in photosynthesis. We then report on the potential of VHF-EMR to address key questions concerning the fundamental mechanisms of the glass-formation process. As a third example we show the interest of VHF-EMR to accurately determine the zero-field splitting parameters of a large-zero-field-splitting system and consequently unequivocally decide upon the structure of the system. The current developments underway at the NHMFL are presented. In the conclusion we conjecture upon the developments of modern EMR.
Improving the performance of the two-rate parameter by use of the integrating ratemeter and temporal optimization

The integrating ratemeter is used in concert with the two-rate parameter to form the integrating ratemeter two-rate parameter. Propagation of error theory is applied to the integrating ratemeter two-rate parameter to yield expressions for the precision of rates calculated from the integrating ratemeter two-rate parameter in terms of the precision of the rates measured with the integrating ratemeter. Simulations and experimental results show that in cases where the standard deviation of the rate is relatively constant, the optimum time to make a rate measurement using the integrating ratemeter is also the optimum time to measure either of the rates in the two-rate parameter. If either of the two rates comprising the two-rate parameter is measured at the optimum time, then the precision and accuracy of concentrations measured with this technique are optimized.
Biological losses and the quarantine policy for Mars.

Mars planetary landing program schedule, COSPAR quarantine policy and biological losses from failures to collect data and from contamination
Prolonged therapy of chronic hepatitis C with ribavirin

Summary. Therapy with ribavirin for 6–12 months is associated with decreases in serum aminotransferases in some patients with chronic hepatitis C. We have assessed the practicality and safety of prolonged therapy with ribavirin. Six patients with chronic hepatitis C were given 1000–1200mg of ribavirin daily for 24 months. Serum aminotranferases and hepatitis C virus (HCV) RNA levels were monitored during and after therapy. Liver biopsies were carried out before and at the end of treatment. With therapy, mean serum alanine aminotransferase (ALT) levels fell from 161 U/L to 45 U/L at 12 months and to 39 U/L at 24 months. HCV RNA levels did not change. Liver histology improved in five and was unchanged in one patient. When therapy was stopped, aminotransferases rose to pretreatment levels. Side effects included mild fatigue and headaches. Two patients developed gallstones during therapy, perhaps caused by the chronic haemolysis that occurred in all patients. In conclusion, prolonged therapy with ribavirin can result in sustained improvements in serum aminotransferases and hepatic histology in a proportion of patients with chronic hepatitis C. Ribavirin therapy does not cause decreases in viraemia and, therefore, probably must be continued indefinitely to provide lasting benefit. The advantages of such therapy must be weighed against possible long-term side-effects.
MG++: Memory graphs for analyzing dynamic data structures

Memory graphs are very useful in understanding the behavior of programs that use dynamically allocated data structures. We present a new memory graph representation, MG++, and a memory graph construction algorithm, that greatly enhance the utility of memory graphs. First, in addition to capturing the shapes of dynamically-constructed data structures, MG++ also captures how they evolve as the program executes and records the source code statements that play a role in their evolution to assist in debugging. Second, MG++ captures the history of actions performed by the memory allocator. This is useful in debugging programs that internally manage storage or in cases where understanding program behavior requires examining memory allocator actions. Our binary instrumentation-based algorithm for MG++ construction does not rely on the knowledge of memory allocator functions or on symbol table information. Our algorithm works for custom memory allocators as well as for in-program memory management. Experiments studying the time and space efficiency for real-world programs show that MG++ representation is space-efficient and the time overhead for MG++ construction algorithm is practical. We show that MG++ is effective for fault location and for analyzing binaries to detect heap buffer overflow attacks.