cssi/SciSciGPT-SciSciNet huggingface dataset:
Pharmacologic Modulation of Multidrug Resistance in Acute Leukemia: Results and Challenges

The limited curative potential of conventional chemotherapy in patients with acute myeloid leukemia (AML) has directed attention to identification of cellular mechanisms contributing to treatment failure. Intrinsic and/or acquired resistance to antineoplastic remains a clinical challenge for patients with poor-risk AML and relapsed patients. Multidrug resistance (MDR) due to overexpression of the mdr1 gene or its membrane product P-glycoprotein (P-gp), has been implicated as an important cellular mechanism of resistance that contributes to treatment failure in this disease [1]. Indeed, prospective studies in de novo AML have shown that overexpression of mdr1 is associated with a lower complete remission rate and shorter remission duration in patients receiving conventional induction and post-remission therapy [2, 3]. P-gp expression has been linked to a number of adverse prognostic variables including age, secondary leukemia, cytogenetic pattern, and a CD34 surface phenotype [3–6]. Evidence to date, indicates that mdr1 expression is determined in part by the lineage and stage of cellular differentiation that mimics its physiologic regulation in blood cell development. Normal hematopoietic stem cells natively express high levels of mdr1, but a corresponding decrease in gene message is seen with myeloid maturation [7, 8]. These observations suggest that expression of the MDR phenotype in AML, therefore, represents a conserved physiologic function.
Cosmic Strings and Galaxy Formation: Overview and Recent Results

The cosmic string model of galaxy formation is briefly summarized and compared with other theories. Some recent results are presented: the origin of galactic angular momentum via tidal torquing is discussed, and the evolution of the mass function is studied.
Chronic familial nonspherocytic hemolytic anemia.

The authors have presented the problems in the diagnosis of an obscure anemia in two sisters which was apparently present at birth. The mechanism could not be established during the initial period of observation. Re-investigation revealed a nonspherocytic, familial, probably hereditary and possibly sex-linked hemolytic anemia. These cases do not fit into any known specific category and are compared with other nonspherocytic hemolytic anemias recorded in the literature. It is suggested that other cases considered to be hypoplastic or aregenerative anemias be re-investigated to exclude the possibility of a hemolytic component.
Tumor necrosis factor alpha inhibits gonadotropin hormonal action in nontransformed ovarian granulosa cells. A modulatory noncytotoxic property.

It has been suggested that resident ovarian macrophages may play a role in the regulation of ovarian function through local paracrine secretion of regulatory molecule(s). It is the objective of the in vitro studies reported herein to evaluate the potential ovarian relevance of one such macrophage product, tumor necrosis factor α (TNF-α). To this end, use was made of a primary culture system of rat ovarian granulosa cells, the functional status of which was monitored by the acquisition of estrogen, progestin, and proteoglycan biosynthetic capacity. Whereas treatment with the gonadotropin follicle-stimulating hormone (FSH), a potent functional regulator, resulted in a substantial increase in the extent of aromatization (conversion of androgenic steroid precursors to estrogens), concomitant exposure to TNF-α (10 ng/ml) produced significant (p
SYNAPTONEMAL COMPLEXES DURING PREMEIOTIC DNA SYNTHESIS IN OOCYTES OF DROSOPHILA MELANOGASTER

Well-synchronized populations of oocytes obtained by means of the "pupal system" (Grell, 1973a) have been examined to determine the time of appearance of the synaptonemal complex. The complex first appears in the most advanced oocytes between 132 and 138 hr of female development. Between 138 and 156 hr the complex apparently undergoes a fourfold increase in length. At 150 and 156 hr the complex system is extensive and present in virtually all oocytes. Previous studies using the pupal system have placed the period of premeiotic DNA synthesis between 132 and 162 hr. Thus, indirect evidence indicates that a significant portion of synaptonemal complex formation is coextensive with the main DNA replication in the oocyte. Direct evidence that DNA synthesis and complex formation occur simultaneously in oocytes has been obtained by electron microscope autoradiography. By definition, then, the stage of synaptonemal complex formation in Drosophila must include premeiotic interphase.
Highly parameterized inverse estimation of hydraulic conductivity and porosity in a three-dimensional, heterogeneous transport experiment

[1] Assessing the impact of parameter estimation accuracy in models of heterogeneous, three-dimensional (3-D) groundwater systems is critical for predictions of solute transport. A unique experimental data set provides concentration breakthrough curves (BTCs) measured at a 0.253 cm3 scale over the 13 × 8 × 8 cm3 domain (∼53,000 measurement locations). Advective transport is used to match the first temporal moments of BTCs (or mean arrival times, m1) averaged at 0.253 and 1.0 cm3 scales through simultaneous inversion of highly parameterized heterogeneous hydraulic conductivity (K) and porosity (φ) fields. Pilot points parameterize the fields within eight layers of the 3-D medium, and estimations are completed with six different models of the K–φ relationship. Parameter estimation through advective transport shows accurate estimation of the observed m1 values. Results across the six different K–φ relationships have statistically similar fits to the observed m1 values and similar spatial estimates of m1 along the main flow direction. The resulting fields provide the basis for forward transport modeling of the advection-dispersion equation (ADE). Using the estimated K and φ fields demonstrates that advective transport coupled with inversion using dense spatial field parameterization provides an efficient surrogate for the ADE. These results indicate that there is not a single set of model parameters, or a single K–φ relationship, that leads to a best representation of the actual experimental sand packing pattern (i.e., nonuniqueness). Additionally, knowledge of the individual sand K and φ values along with their arrangement in the 3-D experiment does not reproduce the observed transport results at small scales. Small-scale variation in the packing and mixing of the sands causes large deviations from the expected transport results as highlighted in forward ADE simulations. Highly parameterized inverse estimation is able to identify those regions where variations in mixing and packing alter the expected property values and significantly improve results relative to the naive application of the experimentally derived property values. Impacts of the observation scale, the scale over which results are averaged and the number of observations and parameters on the final estimations are also examined. Results indicate existence of a representative element volume (REV) at 0.25 cm3, the existence of subgrid scale heterogeneity that impacts transport and the accuracy of highly parameterized models with even relatively small amounts of observations. Finally, this work suggests that local-heterogeneity features below the REV scale are difficult to incorporate into parameterized models, highlighting the importance of addressing prediction uncertainty for small-scale variability (i.e., uncaptured variability) in modeling practice.
Motor activity during searching and walking movements of cockroach legs

1. Rhythmic motor activity may be recorded in the legs of cockroaches during the execution of several different types of behaviour that involve leg movements. It was examined in detail during searching and walking. 2. During walking, motor activity always consisted of a series of bursts separated by silent periods. During searching, it was usually continual, but modulated in frequency. 3. Sometimes, the motor pattern recorded from a searching leg was burst-like rather than modulated. In these cases, it could nevertheless be reliably distinguished from the motor pattern recorded during walking by a simple analysis of the burst pattern. 4. An analysis of the motor pattern recorded during righting indicated that this pattern was more like that for walking than that for searching. Therefore, searching is not simply walking that lacks certain periodic sensory input due to leg contact with the ground. 5. It is concluded that walking and searching can be reliably distinguished from one another on the basis of an analysis of a record of motor activity in a single leg muscle only. An ability to distinguish between similar types of behaviour on the basis of the motor pattern may prove useful in a variety of experiments.
Reversible Deformation of Transfusion Tracheids in Taxus baccata Is Associated with a Reversible Decrease in Leaf Hydraulic Conductance

Declines in leaf hydraulic conductance (Kleaf) with increasing water stress have been attributed to cavitation of the leaf xylem. However, in the leaves of conifers, the reversible collapse of transfusion tracheids may provide an alternative explanation. Using Taxus baccata, a conifer species without resin, we developed a modified rehydration technique that allows the separation of declines in Kleaf into two components: one reversible and one irreversible upon relaxation of water potential to −1 MPa. We surveyed leaves at a range of water potentials for evidence of cavitation using cryo-scanning electron microscopy and quantified dehydration-induced structural changes in transfusion tracheids by cryo-fluorescence microscopy. Irreversible declines in Kleaf did not occur until leaf water potentials were more negative than −3 MPa. Declines in Kleaf between −2 and −3 MPa were reversible and accompanied by the collapse of transfusion tracheids, as evidenced by cryo-fluorescence microscopy. Based on cryo-scanning electron microscopy, cavitation of either transfusion or xylem tracheids did not contribute to declines in Kleaf in the reversible range. Moreover, the deformation of transfusion tracheids was quickly reversible, thus acting as a circuit breaker regulating the flux of water through the leaf vasculature. As transfusion tissue is present in all gymnosperms, the reversible collapse of transfusion tracheids may be a general mechanism in this group for the protection of leaf xylem from excessive loads generated in the living leaf tissue.
Alveolar-Membrane Diffusing Capacity Limits Performance in Boston Marathon Qualifiers

Purpose (1) to examine the relation between pulmonary diffusing capacity and marathon finishing time, and (2), to evaluate the accuracy of pulmonary diffusing capacity for nitric oxide (DLNO) in predicting marathon finishing time relative to that of pulmonary diffusing capacity for carbon monoxide (DLCO).
Relationship Between the OASIS‐2 Aptitude Survey and Grades in College English and Psychology Classes

A total of 36 rising high school seniors (between the 11th and 12th grades), who were taking college classes in English and psychology as part of their participation in a summer program designed to encourage interest in attending college, were administered the OASIS-2 Aptitude Survey, Correlational analyses identified statistically significant relationships between grades in both classes and the general and verbal aptitude measures on the OASIS-2. No statistically significant relationships were identified between other OASIS-2 aptitude measures and grades. Implications for use of the OASIS Aptitude Survey are discussed.
On constrained sintering-II. Comparison of constitutive models

Abstract Several authors have proposed constitutive equations to describe bodies that sinter under constraint. We provide a critical examination of these models and show that some of them imply a negative Poisson's ratio, in contradiction to experimental evidence.
Investigation of subpellicle defect formation at KrF lithography

In this study we investigated the defect due to pellicle frame materials for repeating exposure in months. Defects were found in the sub-pellicle and the defect density was high in the 4 corners compared to the center of the mask. The defects grew on MoSiON or the interface Quartz and MoSiON film, and the defect size was below 0.5 um. By analyzing with Raman Spectroscopy, defects consist of Ammonium Sulfates, Melamine Formaldade Resin and KClO3. The evaluation method for cleaning process and pellicles was Ion Chromatography. According to Ion Chromatography analysis, the main composition of defect was substances of pellicle frame materials. Also we confirmed the pellicle frame effect with the exposure test.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Two layers of neural variability

Variability in neuronal firing rates and spike timing can be modeled as doubly stochastic. A study now suggests that these phenomena could arise from a network built of deterministic neurons with balanced excitation and inhibition.
α-Melanocyte stimulating hormone and adrenocorticotropic hormone: An alternative approach when thinking about restless legs syndrome?

Alpha-melanocyte stimulating hormone (alpha-MSH) and adrenocorticotropic hormone (ACTH) possess properties suggesting that they may be involved in the pathogenesis of restless legs syndrome (RLS). We sought to determine if alpha-MSH and ACTH when administered centrally in rat recapitulate features reminiscent of RLS: increased activity, sleep fragmentation, and periodic movements during sleep. Rats were instrumented with electroencephalography, electromyography, and intracerebral cannulae and recorded for the measurement of sleep, periodic movements, and behavior following intracerebroventricular administration of alpha-MSH, ACTH, or saline. Studied behavior included grooming, locomotion, and rearing during wake and limb movements during sleep. Vigilance states included active wake (AW), quiet wake (QW), slow wave sleep I (SWSI), slow wave sleep II (SWSII), and paradoxical sleep (PS). All rats received normal saline acting as their own controls. Different rats received alpha-MSH in doses of 0.05, 0.5, 1.0, 2.0, and 6.0 microg or ACTH in doses of 0.5, 1.0, and 2.0 microg. Administered alpha-MSH caused an increase in waking behavior and prolongation of sleep latency, while ACTH stimulated waking behavior and fragmented sleep, yielding more AW and less SWSII and PS. Both hormones increased periodic movements during sleep. When administered centrally in rat, alpha-MSH and ACTH stimulate motor activity in wake, cause changes in sleep architecture, and increase periodic movements in sleep. These melanocortin hormones may play a role in the pathogenesis of RLS.
Long-term outcome of retroperitoneal lymph node dissection in the management of testis cancer

In low volume testicular cancer, (clinical stage A/B1) retroperitoneal lymph node dissection has maintained its therapeutic benefit while minimizing morbidity with the reduction of the surgical template from a full bilateral dissection to a unilateral nerve-sparring surgery. The optimal treatment for low stage disease is largely patient driven with surgery and surveillance considered the primary treatment modalities. In the post chemotherapy population, patients with complete radiographic resolution of retroperitoneal disease are observed at Indiana University as the relapse rate in this population is approximately 5%. Residual masses after chemotherapy should be resected. A modified post chemotherapy dissection is adequate in low volume disease restricted to the primary landing zone of the affected testicle. In chemo-refractory disease, aggressive surgery provides a 5 year survival of 31% for patients with active cancer. Excluding chemo-naive patients, late relapse disease is managed surgically with 50% being cured of disease.
Indirect contributions to electron-impact ionization of Kr24+, Kr25+, and Xe43+

Electron-impact ionization cross sections have been calculated for ${\mathrm{Kr}}^{24+}$ and ${\mathrm{Kr}}^{25+}$. The contributions of excitation-autoionization and resonant excitation double autoionization (REDA) were included in addition to the cross sections for direct ionization of a 3s electron. For ${\mathrm{Xe}}^{43+}$ the REDA contributions were extended to two times the ionization threshold. The calculations were performed using the relativistic distorted-wave and the multiconfiguration Dirac-Fock methods. For ${\mathrm{Kr}}^{25+}$ the indirect processes enhance the ionization cross section by a factor of 4. For ${\mathrm{Kr}}^{24+}$ the total cross section is about 3.5 times the direct-ionization cross section. The REDA process produces numerous strong resonances and contributes about 20% to the average ionization cross section for ${\mathrm{Kr}}^{24+}$ and ${\mathrm{Kr}}^{25+}$ and 15% to the average ionization cross section for ${\mathrm{Xe}}^{43+}$.
Prediction of Natural Convection Heat Transfer in Layered Porous Cavities by Homogeneous Anisotropic Model

Steady-state heat transfer by natural convection in a layered porous cavity is examined by using homogeneous anisotropic model. The geometry considered is a two-dimensional square enclosure comprising of three or four porous layers with non-uniform thickness and distinct permeability. The cavity is subjected to differential heating from the vertical walls. The results, which include the flow patterns and temperature profiles as well as the heat transfer coefficients, are presented for a wide range of permeability ratio, sublayer thickness ratio, and Rayleigh number. Particularly, the heat transfer results obtained are compared with those reported from a rigorous numerical model for layered porous media. In addition, the results are compared with the lumped system model that was proposed recently. It has been found that homogeneous anisotropic model predicts the heat transfer coefficient reasonably well within the conductive flow regime. However, beyond this regime, the model fails to represent the layered case for the effective permeabilities and sublayer thickness ratios considered. On the other hand, it is observed that the lumped system model offers better agreement to the heat transfer coefficient of the actual layered porous system over a wider range of parameters and which also significantly reduces computational efforts.© 2008 ASME
Detection and determination of minor components in nominally pure solids by raman spectroscopy

The problems encountered in applying Raman spectroscopy to direct qualitative and quantitative analysis for minor impurities in nominally pure, colorless solids have been examined. Samples of sulfamethoxazole spiked with 0.5 to 5% of sulfanilamide and sulfanilic acid were used as test materials. A procedure is described which permits detection of spectral features of the specified impurities at the 0.5% level. Least-squares fitting and cross-correlation data treatment procedures for the determination of sulfanilamide in sulfamethoxazole, with limits of detection of about 0.1% for either approach, are described. Computer simulations have been used to examine detection of impurity peaks for a variety of conditions, including the worst-case scenario in which the impurity features coincide with the strongest features of the spectrum of the host material. A least-squares fitting approach is described which permits detection of the impurity peak at the 0.5% level, even under worst case conditions.
“Anchoring” white community: White women activists and the politics of public schools

This article discusses the political clout wielded by a group of white women who participate in “Presidents’ Committee,” an organization of Parents Association presidents in a New York City Community School District. The school district, like many urban areas, is experiencing an exodus of white families to the suburbs, which are seen as offering better resources and a safe social distance from blacks and other non‐whites. In this context of social change, white mothers who participate in Presidents’ Committee push at gender boundaries in the public sphere by professionalizing motherhood and watching over potentially corrupt political practices. At the same time, their activism can be understood as a key component of local efforts to reproduce “white” community. Through this ethnographic analysis, “whiteness” is unpacked as a construct that is fractured by gender, class, and place of origin, while remaining a resilient idealized resource with which to reproduce a black/white racial binary.
A re-examination of the polyurethane reaction

Abstract The general base-catalyzed formation of polyurethanes is shown to involve the attack of the nucleophilic oxygen of the alcohol on the electrophilic carbon of the isocyanate. Although the base probably functions by increasing the nucleophilicity of the oxygen through hydrogen-bonding to the adjacent proton, this is, at present, unclear, because of the large number of side reactions, the existence of complexes, and the poorly understood role of the solvent. The metal complex-catalyzed formation of polyurethanes appears to occur in one of two ways: one for Sn4+ complexes and the other, for all other octahedral, as well as planar, complexes. The mechanism for the tin complexes involves an initial reaction with alcohol to form tin alkoxides, while the other mechanism involves the reaction of a metal-isocyanate complex with uncomplexed alcohol. The general base catalysis/metal complex catalysis synergism is discussed and is shown to fit the proposed mechanisms.
Nonalcoholic Wernicke’s Encephalopathy Associated with Unintentional Weight Loss, Cholecystectomy, and Intractable Vomiting: The Role of Dual Thiamine and Corticosteroid Therapy

A 23-year-old male with one month of intractable vomiting, subsequent cholecystitis status post cholecystectomy, and overall 40-pound weight loss over the last few months presented with altered mental status and seizures. MRI showed signal abnormalities involving the hypothalamus, periaqueductal gray matter, 4th ventricle, and bilateral thalami, indicative of Wernicke's encephalopathy. The patient was started on empiric IV thiamine and methylprednisolone; thiamine levels were subsequently found to be low. Infectious disease workup was negative. Within a few days of this therapy, the patient's neurological status steadily improved with increased responsiveness and communication. Repeat MRI 7 days after admission showed significant resolution of the signal abnormalities. Over the next several weeks the patient became fully conversational, cognitively intact, and increasingly ambulatory. Nonalcoholic Wernicke's encephalopathy is rare; there have been reports relating it separately to vomiting and invasive surgery. In this case report, we associate it with both recurrent vomiting and minimally invasive cholecystectomy. We also discuss combinatorial therapy of thiamine and corticosteroids, which is poorly defined in the literature. Though there is no consensus-based optimal treatment of Wernicke's encephalopathy, this adds to the discussion of using dual therapy and supports that the use of empiric corticosteroids does not harm the patient.
Price forecasting and trigger price probability estimation

Abstract This paper shows how probability estimation, incorporated within price prediction from a single equation, will enhance the usefulness of forecast information and will have greater intuitive appeal. The estimated probability is the probability that the price will cross some predetermined threshold of importance, a trigger price. This procedure is likely to be more useful in economic decision making than the application of prediction interval estimates since the latter approach does not convey threshold probability information. Empirical application encompasses forecasting in the watermelon production industry to demonstrate the power and appeal of the approach. All probability estimates were more precise than a 0.5 probability of occurence.
The surgical treatment of concomitant atrial arrhythmias during redo cardiac operations.

Background With improving surgical care yielding better outcomes, patients who have undergone a cardiac operation are surviving longer, and surgeons will inevitably face an increasing number of reoperative procedures. There are few data reporting risk and outcome for patients undergoing atrial fibrillation ablation in this clinical setting. Methods From January 1994 through May 2009, we performed surgery for AF in 245 patients (134 female) who have had at least1 prior cardiac operation. Median age was 45 years (range 1 to 75 years) and preoperative atrial fibrillation was paroxysmal in 161 patients (66%). Most common cardiac diagnoses included Ebstein anomaly (n = 43), tetralogy of Fallot (n = 36), and acquired valvular or ischemic heart disease (n = 35). Median prior sternotomies was 1 (range 1 to 6). Results Ablative lesions most commonly included isolated right-sided maze (n = 123; cryothermy in 84, cut and sew in 39), biatrial maze (n = 52; cryothermy in 26, cut and sew in 26), and right atrial isthmus ablation (n = 41; isolated in 30, concomitant in 11). There were 14 early deaths (5.7%). New permanent pacemaker was required in 39 patients (18%); indication was complete heart block in 9. Rhythm at late follow-up (median: 4.1 years, maximum: 17.2 years) was 89% in the setting of congenital heart disease and 78% in acquired heart disease. Conclusions Atrial fibrillation is common with a variety of pathologies requiring redo cardiac surgery. Lesion set and energy source are dependent on primary procedure. Concomitant AF ablation during redo cardiac reoperations can be performed with reasonable safety and success.
Laser Ablation of Metals: A New Method for Preparing SERS Active Colloids

Laser ablation of metals is a new and very powerful method for preparation of surface-enhanced Raman scattering (SERS) active colloids. The method is characterized by its simplicity and versatility. Stable Ag, Au, Pt, Pd, and Cu colloids are prepared by ablation of the metal for ~ 10 min in water and organic solvents. An important advantage of this approach over conventional chemical procedures is that the colloids are free of organic or ionic species. Consequently, the chemical and physical effects of ions or other adsorbates can be studied under carefully controlled conditions. The SERS activity of colloidal metals prepared by laser ablation is comparable or superior to that of chemically prepared colloids.
Thermo‐chemical response of vinyl‐ester resin

Abstract : This report presents the thermochemical characterization of Dow Derakane 411-C50 commercial vinyl-ester resin at low temperatures (20 deg - 40 deg C). Differential scanning calorimetry (DSC) and torsional braid analysis (TBA) are the experimental techniques used to characterize the material behavior. The cure kinetics are studied using DSC and are modeled using a modified autocatalytic equation with a maximum degree of cure term. Also, the effect of inhibitors in the resin system is accounted for by an inhibitor depletion model. A time-temperature-transformation diagram is constructed for the material by measuring the times to gelation and vitrification using TBA. The glass transition temperature (T(sub g)) is also characterized using the TBA and related to the degree of cure. It was found that the T(sub g) and the degree of cure do not exhibit a linear relationship for this resin system. The findings presented in this work provide information for accurate cure modeling and process simulation of vinyl-ester materials.
Serum β-Amyloid Correlates with Neuropsychological Impairment

ABSTRACT Aims: Evidence suggests a relationship between peripheral Aβ and AD. We hypothesized that higher levels of serum Aβ1–42 would be associated with memory impairment, thought to occur early in the disease, and rises in serum Aβ1–40, which occur later, would be associated with impairment in non-memory measures. Methods: Using a cross-sectional design, we examined the relationship of serum Aβ1–40, Aβ1–42, and the ratio of Aβ1–42/1–40 to neuropsychological measures in 40 cognitively normal controls, 13 MCI subjects, and 25 AD patients. Results: Serum Aβ1–42 and the ratio of Aβ1–42/1–40 were significantly higher in the MCI group compared to the controls. A significant relationship in the hypothesized direction (poorer scores associated with higher Aβ1–40 serum levels) was found between Aβ1–40 and measures of executive functions across the entire cohort of individuals tested and with measures of language and processing speed in the AD group. Regression analysis found that neuropsychological measures acco...
Allocentric spatial neglect with posterior cortical atrophy.

Patients with posterior cortical atrophy (PCA) have been reported to have neglect in the egocentric/ body-centered reference frame. This report describes a woman with PCA who had a right-sided stimulus-based form of allocentric visual neglect on cancellation, reading, and drawing tests. Her brain imaging revealed left parietal atrophy. The pathophysiology of this disorder may be related to an impairment of the ventral “what” stream’s ability to interact with the dorsal “where” stream that mediates the allocation of spatial attention, or a deficit in the systems that allocate contralateral focal attention. Further research is needed to better understand the mechanisms of this disorder and to optimally treat it.
Lightning propagation and flash density in squall lines as determined with radar

Lightning echo rise times and range-time variations due to discharge propagation are determined using S and L band radars, and the evolution of precipitation reflectivity and the associated lightning activity in squall lines is investigated using VHF and L band radars. The rise time of radar echoes can be explained by ionized channel propagation through the radar beams. Speeds of at least 250,000 m/s are found from measurements of the radial velocity of streamer propagation along the antenna beam. The range-time variations in lightning echoes indicate that either new ionization occurs as streamers develop into different parts of the cloud, channel delay occurs during which adequate ionization exists for radar detection, or continuing current occurs. Determinations of the lightning flash density for a squall line in the U.S. show that the maximum lightning density tends to be near the leading edge of the precipitation cores in developing cells. Long discharges are produced as a cell in the squall line develops and the total lightning density increases, although short discharges predominate. As the cell dissipates, short flashes diminish or cease and the long flashes dominate the lightning activity.
Boronic acid-appended bis-viologens as a new family of viologen quenchers for glucose sensing

Abstract A new family of boronic acid-appended viologen quenchers has been synthesized containing two viologen subunits in a single quencher moiety. Relative to the single viologen-based quenchers previously developed in our laboratory, the bis-viologen ortho-boronic acid (BoB) compounds, in combination with the fluorescent dye, HPTS, display greatly enhanced Stern–Volmer quenching constants and much greater signal modulation in response to glucose. The superior performance is realized at lower quencher-to-dye ratios than are required for the single-viologen systems.
Is the “astrometric” plate reduction method rigorous?

It is shown that there is no intrinsic difference between the so-called “astrometric” and “photogrammetric” methods of reducing star plates, and that either, when applied by competent investigators, will yield equivalent results. Es wird gezeigt, das zwischen den sogenannten “astrometrischen” und “photogrammetrischen” Plattenreduktionen kein wesentlicher Unterschied besteht, und das beide Methoden, wenn richtig angewendet, gleichwertige Resultate ergeben.
The overall elastic response of materials containing spherical inhomogeneities

Abstract It is proposed to determine the overall response of linear elastic materials containing non-intersecting spherical inhomogeneities without altering the microscopic geometry of a given representative volume element. In the proposed method, a system of integral equations formulated for such an element is accurately approximated by a system of linear algebraic equations.
Results of aortic valve-sparing and restoration with autologous pericardial leaflet extensions in congenital heart disease.

Background The purpose of this study is to evaluate the efficacy of aortic valve-sparing repair with glutaraldehyde-treated autologous pericardium in congenital valvular pathology. Methods Sixty-two patients underwent reparative aortic valve surgery from January 1997 through December 2003. The mean age was 25 ± 20 years (± standard deviation) (range, 10 days to 81 years). Fifty percent (31 of 62) were less than 19 years old at operation. The diagnoses included bicuspid aortic valve (39 patients), ventricular septal defect (14 patients), severe aortic stenosis (6 patients), subaortic stenosis (7 patients), bacterial endocarditis (7 patients), neonatal truncus arteriosus (2 patients), Shone's complex (2 patients), transposition complex (1 patient), double-chambered right ventricle (1 patient), and Marfan's syndrome (1 patient). Twelve patients (19 %) had prior sternotomy and cardiac operations. Valve-sparing techniques included pericardial leaflet extensions in 62 patients, creation of one or more pericardial neoaortic sinuses in 8, subcommissuroplasty in 8, pericardial patch of perforated leaflets in 9, Dacron mesh wrap (Boston Scientific, Wayne, NJ) of dilated ascending aorta in 12, and concomitant tricuspid and mitral valve repairs in 3 and 4 patients, respectively. Results There was one early death (1.6%). There were no late deaths at a mean follow-up of 25 ± 16 (range, 0.1 to 72.5 months). Six patients required reoperation and prosthetic or homograft replacement for aortic valve incompetence. One out of 6 reoperations required re-repair. The remaining patients are well with a mean aortic regurgitation grade by echocardiography of 1.3 ± 0.9 (scale, 0 to 4). Conclusions Aortic valve repair with pericardial leaflet extension is a promising technique for the growing child.
Fusion reactor application issues for low activation SiC/SiC composites

Abstract Silicon carbide composites are attractive for fusion applications beacuse of their low activation and afterheat properties coupled with excellent high-temperature properties. Their application will require material development and an expanded data base as well as evaluation for high-temperature stability, chemical compatibility with fusion relevant coolants, thermal conductivity, thermal fatigue and shock, hermetic properties, joining methodology and radiation stability. Preliminary data suggest that commercially available material has adequate performance for some requirements in its present form or that there are identifiable routes to improve the performance. This paper summarizes SiC/SiC behavior relative to some performance requirements and identifies areas where further research is needed.
The β-Amyloid Precursor Protein APP Is Tyrosine-phosphorylated in Cells Expressing a Constitutively Active Form of the Abl Protoncogene

The cytosolic domain of the β-amyloid precursor protein APP interacts with three PTB (phosphotyrosine binding domain)-containing adaptor proteins, Fe65, X11, and mDab1. Through these adaptors, other molecules can be recruited at the cytodomain of APP; one of them is Mena, that binds to the WW domain (a protein module with two conserved tryptophans) of Fe65. The enabledand disabled genes of Drosophila, homologues of the mammalian Mena and mDab1 genes, respectively, are genetic modulators of the phenotype observed in flies null for the Abl tyrosine kinase gene. The involvement of Mena and mDab1 in the APP-centered protein-protein interaction network suggests the possibility that Abl plays a role in APP biology. We show that Fe65, through its WW domain, binds in vitro andin vivo the active form of Abl. Furthermore, in cells expressing the active form of Abl, APP is tyrosine-phosphorylated. Phosphopeptide analysis and site-directed mutagenesis support the hypothesis that Tyr682 of APP695 is the target of this phosphorylation. Co-immunoprecipitation experiments demonstrate that active Abl and tyrosine-phosphorylated APP also form a stable complex, which could result from the interaction of the pYENP motif of the APP cytodomain with the SH2 domain of Abl. These results suggest that Abl, Mena, and mDab1 are involved in a common molecular machinery and that APP can play a role in tyrosine kinase-mediated signaling.
Generalized derivation of an exact relationship linking different coefficients that characterize thermodynamic effects of preferential interactions

In solutions consisting of solvent water (component '1') and two solute components ('2' and '3'), various thermodynamic effects of differences between solute-solute and solute-solvent interactions are quantitatively characterized by state functions commonly called 'preferential interaction coefficients': gamma(mu(1),mu(3)) triple bond (delta(m3)/delta(m2))(T,mu(1),mu(3)) and gamma(mu(k)) triple bond (delta(m3)/delta(m2))(T,P,mu(k)), where k = 1,2 or 3. These different derivatives are not all directly accessible to experimental determination, nor are they entirely equivalent for analyses and interpretations of thermodynamic and molecular effects of preferential interactions. Consequently, various practical and theoretical considerations arise when, for a given system, different kinds of preferential interaction coefficients have significantly different numerical values. Previously we derived the exact relationship linking all three coefficients of the type gamma(mu(k), and hence identified the physical origins of the differences between gamma(mu(1)) and gamma(mu(3)) that have been experimentally determined for each of various common biochemical solutes interacting with a protein [J. Phys. Chem. B, 106 (2002) 418-433]. Continuing our investigation of exact thermodynamic linkages among different types of preferential interaction coefficients, we present here a generalized derivation of the relationship linking gamma(mu(1),mu(3)), gamma(mu(3)) and gamma(mu(1)), with no restrictions on m(2), m(3) or any physical characteristic of either solute component (such as partial molar volume). Hence, we show that (gamma(mu(1),mu(3)) - gamma(mu(3))) is related directly to (gamma(mu(3)) - gamma(mu(1))), for which the physical determinants have been considered in detail previously, and to a factor dependent on the ratio of the partial molar volumes V3/V1. Our generalized expression also provides a basis for calculating gamma(mu(1),mu(3)), even in situations where preferential interactions could not be investigated by equilibrium dialysis. To demonstrate this applicability, we analyze isopiestic distillation data for aqueous solutions containing urea and NaCl, two small solute components that cannot be selectively dialyzed.
Review: Primary Hyperparathyroidism, an Update: Incidence, Etiology, Diagnosis, and Treatment

ABSTRACT The past 15 years have witnessed several advances in knowledge about primary hyperparathyroidism. Incidence studies have revealed it to be a disease of aging. Known etiologies now include prior radiation exposure and several familial syndromes. Diagnosis has been simplified by a new generation of radioimmunoassays for parathyroid hormone. The natural history of mild hyperparathyroidism, as revealed by a single study, is one of a stable or slowly progressive disorder, with approximately half of those observed for 10 years showing sufficient progression or new complications to mandate surgery. The course of untreated hyperparathyroidism of more severe degree has not been well documented. Only two medical treatments have been shown to produce beneficial biochemical effects, namely neutral phosphate and estrogens; each is appropriate only for a narrow target group. Surgical treatment is safe and highly effective in experienced hands, and published data suggest a very low rate of recurrence after resection of parathyroid adenomas. Real time, high resolution ultrasonography is proving to be an effective tool for preoperative evaluation of the location and number of abnormal parathyroids.
Use of tactile afferent information in sequential finger movements

We have investigated how tactile afferent information contributes to the generation of sequences of skilled finger movements by anesthetizing the right index fingers of experienced typists. Subjects were asked to type phrases in which the right index finger was used only once every seven to 12 keypresses. The time at which each key was depressed was recorded with a digital timer, and the translational and rotational motion of the fingers and wrist of the right hand were recorded optoelectronically from the location of reflective markers placed on the fingers. Midway through the experiment, a local anesthetic was injected at the base of the distal phalange of the right index finger. Following digital anesthesia, error rates increased considerably, mainly due to the diminished accuracy of movements of the anesthetized finger. The typing intervals following keypresses with the anesthetized fingertip were unaffected by the removal of tactile information. When errors occurred during control trials, the intervals immediately following the errors were greatly prolonged. However, errors produced with the anesthetized right index finger did not influence the timing of subsequent keypresses, implying that lack of tactile cues affected error recognition. The movement patterns during keypresses were similar before and after digital anesthesia for some subjects, while a less pronounced flexion-extension movement was seen in other subjects. The results suggest that tactile afferent information is not essential for initiating movement segments in a sequence. Rather, they emphasize the importance of this information for ensuring movement accuracy and for detecting errors.
Comparison of sulfur concentrations within lake sediment profiles

Sediment cores from lakes in four regions (Adirondacks, Northern New England, Northern Great Lakes States, and Northern Florida) were analyzed for total S concentration. In all regions S concentrations in pre-1900 (1820–1900) sediment were similar and pre-1900 net sediment accumulation rates of S were not significantly different. Sulfur enrichment was greatest in Adirondack lake sediment (Big Moose L., Upper Wallface P., Queer L., and Deep L.), which had total post-1900 S accumulation of 1.1 to 7.4 times pre-1900 S accumulation; post-1900 net sediment accumulation rates of S were significantly greater than the other regions. Sediment from Maine (Little Long P. and Haystack P.) and Vermont (Mud P.) generally had lower S concentration than Adirondack sediments. Sulfur enrichment factors in these lakes ranged from 1.2 to 2.1. There was a positive correlation between contemporary limnetic sulfate concentration and post-1900 net sediment accumulation rates for Adirondack and Northern New England study lakes. Sediment from the Northern Great Lakes States region (McNearney, Andrus, Hustler L. and Dunnigan L.) had similar S concentration and distribution with depth to Northern New England sediment. In two Northern Florida lakes (Mirrow and Fore) sediment showed little variation in S concentration with depth, but L. Mary and L. Barco had higher S in deeper layers (30–55 cm). These different patterns of S distribution among lakes were attributed to differences in limnetic sulfate concentration, organic and inorganic sedimentation, and S diagenesis.
Mental retardation plus macrocephaly in a 16-year-old boy

The evaluation of mental retardation is a frequent and challenging problem in pediatric neurology. Often clues obtained on history or by physical examination will help to direct the evaluation in the appropriate channel. This 16-year-old boy had clinical features which suggested the appropriate diagnostic studies.
A multi-rate multiple model track-before-detect particle filter

Current particle filter track-before-detect (PF-TBD) algorithms assume constant velocity (CV) motion and the filter updates at a full-rate (i.e. at every measurement scan). Previous work in multi-rate processing, via a discrete wavelet transform (DWT), has shown that multi-rate tracking algorithms can provide comparable performance at a lower computational cost. To date, these multi-rate approaches have not yet been applied to low signal-to-noise ratio (SNR) targets. This paper presents a full-rate multiple model particle filter for track-before-detect (MMPF-TBD) and a multi-rate multiple model track-before-detect particle filter (MRMMPF-TBD) that extends the areas mentioned above and tracks low SNR targets which perform small maneuvers. The MRMMPF-TBD and MMPF-TBD both use a combined probabilistic data association (PDA) and maximum likelihood (ML) approach. The MRMMPF-TBD provides equivalent root-mean-square error (RMSE) performance at substantially lower particle counts than a full-rate MMPF-TBD. A performance analysis for various SNR and particle count scenarios is presented.
Some Thoughts on the Relationship Between Behaviorism, Comparative Psychology, and Ethology

Although there has been considerable literature produced on the relationship between behaviorism, comparative psychology, and ethology; there has not been a considerable consensus of opinion. Our position, more historically situated than many, argues that the crucial distinction remains simply: “Why does each discipline use animals as subjects?” Drawing on actual position statements by definitional figures, we believe that answers to this probative inquiry amply illustrates the substantial differences between these long-standing traditions.
The Influence of Lexical Familiarity on Children's Function Morpheme Omissions: A Nonmetrical Effect?☆

Abstract Previous research on children's production of function morphemes demonstrated an effect of meter, such that syllabic morphemes that fit a Strong–weak metrical template were omitted less frequently than morphemes not fitting such a template. The current research addressed the question of whether all omissions of syllabic function morphemes occur when a syllable does not fit a metrical template, or whether other factors, such as lexical familiarity, also play a role. Two experiments demonstrated that 2-year-olds are more likely to omit object articles from sentences containing novel nouns or verbs than sentences containing well-known words. Furthermore, familiarity appears to influence omissions independent of meter, suggesting that function morpheme omissions are caused by at least two mechanisms. One possible mechanism, control over utterance timing, is discussed.
Entropy of a three-dimensional random-tiling quasicrystal.

A numerical calculation of the entropy of a three-dimensional randomly rearranged Penrose tiling is described. The entropy per tile is obtained to be 0.24{plus minus}0.02.