cssi/SciSciGPT-SciSciNet huggingface dataset:
Carrier-mediated Transport of the Folic Acid Analogue, Methotrexate, in the L1210 Leukemia Cell

Abstract Transport of methotrexate (4-amino-10-methylpteroyl-glutamic acid), a structural analogue of folic acid, was studied in L1210 mouse leukemia cells grown in tissue culture. Intracellular methotrexate was present in two states. (a) There was an essentially nonexchangeable intracellular fraction probably bound to the enzyme dihydrofolate reductase. (b) The remaining intracellular methotrexate was rapidly exchangeable and likely present in the cell water in an osmotically active state. In addition, there was a small rapidly exchanging component of methotrexate associated with the cells which had the characteristics of a loose adsorption on or near to the cell membrane. Methotrexate was shown to be negligibly metabolized by this cell system. Because of the presence of tight intracellular binding sites for methotrexate, prior to saturation of these sites, free intracellular methotrexate does not appear and consequently efflux is negligible. This permits the accurate measurement of unidirectional uptake velocities. The major portion of the unidirectional influx process demonstrated Michaelis-Menten kinetics with a high degree of structural specificity, competitive inhibition by folic and folinic acids, and marked temperature dependence. Addition of these competing substances in excess to cells at the steady state with extracellular methotrexate leads to countertransport of intracellular methotrexate. Electrochemical potential gradients for free intracellular methotrexate were demonstrated at low levels of extracellular methotrexate and intracellular methotrexate concentrations at equilibrium exhibited Michaelis-Menten kinetics. Efflux of intracellular methotrexate was not first order and appeared to be partially saturated. The Michaelis constant and maximum velocity for the unidirectional efflux process were estimated, and when related to these parameters for the unidirectional influx, were compatible with an accumulating system. These studies indicate that methotrexate transport in the L1210 cell is carrier-mediated and uphill. Methotrexate exhibits several qualities which make it a valuable "model substrate" for the study of the transport characteristics of folic acid and its naturally occurring derivatives. The implication of these findings with respect to the development of more effective folic acid antagonists is considered.
Blind identification of channels with rational transfer functions

The blind identification of systems using the second-order output cyclic spectra is considered. It is shown that the class of minimal, stable, rational causal (MSRC) systems is not identifiable, and the identification is limited by a nontrivial ambiguity associated with the so-called cyclic all-pass factor. The largest subclass of MSRC systems that ensures the unique identification is shown to be the set of MSRC systems that do not have special uniformly spaced maximum phase zeros. A constructive procedure is presented for the identification of system poles and zeros from those of the cyclic spectra.
UF Center for Precollegiate Education and Training: University Partnerships for K-12 Research and Education

The Center for Precollegiate Education and Training (UF CPET) promotes and supports the use of the facilities and faculty of the research university in the preparation and enhancement of science an...
Astronomy and Empire in the Ancient Andes: The Cultural Origins oflnca Sky Watching

Astronomy and Empire in the Ancient Andes: The Cultural Origins oflnca Sky Watching. Brian S. Bauer and David S. P. Dearborn. Austin: University of Texas Press,1995 .220 pp.
P-Q and P-V Control of Photovoltaic Generators in Distribution Systems

In this paper, simultaneous control of active power and volt/var is explored with photovoltaic (PV) generators in distribution systems. The PV active power output can be controlled in the load-following mode when sufficient solar power is available to supply a local load, or the maximum power point tracking (MPPT) mode when a local load is large or injection to the system is allowed. Two selected control approaches, P-Q control in the load-following mode and P-V control in the MPPT mode, are investigated in this paper. The P-Q control is implemented with a relatively simple approach, while the P-V control demands an extra MPPT logic, which is solved based on a power balance between the dc and ac sides in a two-stage PV configuration. The control algorithms are tested with the IEEE 13-bus distribution feeder with various system conditions like the presence of multiple PV generators, imbalance, harmonics, and faults. The MATLAB and SimPowerSystems simulation results clearly demonstrate the capability of the proposed control in maintaining the P/V bus as either a P-Q or P-V bus depending on different applications.
One-dimensional magnetohydrodynamic flow and the Monge-Ampère equation

Nous considerons les ecoulements unidimensionnels et non-stationnaires d'un fluide ideal, non-visqueux et compressible, parfaitement conducteur de l'electricite, soumis a l'action d'un champ magnetique transversal, et l'equation de Monge-Ampere. Dans le cas limite d'un champ magnetique nul, la solution se reduit exactement a celle du probleme correspondant de la dynamique classique des gaz.
Non-vesicular and vesicular lipid trafficking involving plastids

In plants, newly synthesized fatty acids are either directly incorporated into glycerolipids in the plastid or exported and assembled into lipids at the endoplasmic reticulum (ER). ER-derived glycerolipids serve as building blocks for extraplastidic membranes. Alternatively, they can return to the plastid where their diacylglycerol backbone is incorporated into the glycerolipids of the photosynthetic membranes, the thylakoids. Thylakoid lipids are assembled at the plastid envelope membranes and are transferred to the thylakoids. Under phosphate-limited growth conditions, galactolipids are exported from the outer plastid envelope membranes to extraplastidic membranes. Proteins, such as TRIGALACTOSYLDIACYLGLYCEROL1 (TGD1) or VESICLE-INDUCING PROTEIN IN PLASTIDS1 (VIPP1), which are involved in different aspects of plastid lipid trafficking phenomena have recently been identified and mechanistic models that are based on the analysis of these components have begun to emerge.
Long‐term efficacy of cognitive training for age‐associated memory impairment: A six‐month follow‐up study

The purpose of this investigation was to assess the impact of pretraining on the long‐term effect of an imagery‐based mnemonic in persons with age‐associated memory impairment (AAMI). Eighty‐two participants were randomly assigned to one of six groups: (1) verbal judgment pretraining plus mnemonic training, (2) visual imagery elaboration pretraining plus mnemonic training, (3) relaxation pretraining plus mnemonic training, (4) nonspecific pretraining plus mnemonic training, (5) nonspecific training, and (6) wait list. Participants receiving the three specific pretraining techniques along with mnemonic training (Groups I to 3) recalled more than those receiving nonspecific pretraining with mnemonic training (Group 4) or nonspecific pretraining without mnemonics (Group 5). Participants receiving mnemonic training (Groups 1 to 4) did not differ from nonmnemonic controls (Group 5) at 6 months. The results suggest that specific pretraining strategies can help maintain beneficial effects of imagery‐based mnemon...
Phylogenetic beta diversity: linking ecological and evolutionary processes across space in time

A key challenge in ecological research is to integrate data from different scales to evaluate the ecological and evolutionary mechanisms that influence current patterns of biological diversity. We build on recent attempts to incorporate phylogenetic information into traditional diversity analyses and on existing research on beta diversity and phylogenetic community ecology. Phylogenetic beta diversity (phylobetadiversity) measures the phylogenetic distance among communities and as such allows us to connect local processes, such as biotic interactions and environmental filtering, with more regional processes including trait evolution and speciation. When combined with traditional measures of beta diversity, environmental gradient analyses or ecological niche modelling, phylobetadiversity can provide significant and novel insights into the mechanisms underlying current patterns of biological diversity.
Research Note: Assessing the Perceived Seriousness of White-Collar and Street Crimes

Controversy surrounds the ranking of crime seriousness of white-collar crimes relative to street crimes, with early research suggesting the general public is indifferent to crimes of the elite, whereas more recent research indicates that the public thinks certain types of white-collar crime are serious. Building on prior research limitations and using data from a national random probability sample, this study compares the seriousness ratings of a number of white-collar and street crimes and examines the factors that distinguish seriousness ratings across the crime types. The analyses indicate that certain types of white-collar crimes are ranked as more serious than street crimes and that a limited set of demographic correlates distinguish seriousness ratings across the two crime types. Future research directions are outlined.
Changes in cytoskeletal organization in polyoma middle T antigen-transformed fibroblasts: involvement of protein phosphatase 2A and src tyrosine kinases.

The major transforming activity of polyomavirus, middle T antigen, targets several cellular regulatory effectors including protein phosphatase 2A and src tyrosine kinases. Although transformed cells exhibit profound morphological changes, little is known about how middle T antigen-induced changes in the cellular regulatory environment specifically affect the cytoskeleton. We have investigated these changes in 10T½ mouse fibroblasts transformed with polyoma middle T antigen. Immunofluorescence microscopy revealed that expression of middle T antigen (Pym T cells) depleted the stable (acetylated) microtubule array and increased the sensitivity of dynamic (tyrosinated) microtubules to nocodazole-induced disassembly. These effects were associated with a modest but statistically significant (P≤0.05) increase in recovery of protein phosphatase 2A activity with microtubules. Middle T antigen expression also depleted the normal cellular complement of actin stress fibers and focal adhesions, in parallel with changes in the distribution of src tyrosine kinases. Herbimycin A promoted recovery of paxillin and phosphotyrosine into nascent focal adhesion sites, in addition to restoring normal src tyrosine kinase distribution. However, herbimycin A did not restore actin stress fibers or parental-type microtubules to Pym T cells. We suggest that regulation of the microtubule array by middle T antigen may occur through direct effects including redistribution of protein phosphatase 2A as well as indirect effects such as altered interactions with actin-based stress fibers. Cell Motil. Cytoskeleton 47:253–268, 2000. © 2000 Wiley-Liss, Inc.
Cadmium accumulation in the lung, liver and kidney of mice and rats chronically exposed to cigarette smoke

Cigarette smoking constitutes a major source of cadmium exposure via inhalation in man. To determine how smoke exposure affects the organ distribution and accumulation of cadmium, male C57B1 mice and Sprague-Dawley rats were exposed daily for 52-60 consecutive weeks to mainstream smoke from the University of Kentucky reference cigarettes (2R1) in a nose-only exposure system. Exposed mice and rats averaged blood carboxyhemoglobin values of 17.7 and 7.2%, and a daily total particulate matter (TPM) dose of 7.2 and 3.2 mg kg-1 body wt. per exposure, respectively. These results suggested effective inhalation of smoke by the animals. The tissues were acid digested and analyzed for cadmium by atomic absorption spectrometry. Cadmium levels 5-6- and 2-3-fold greater than control levels were detected in the lungs and kidneys, respectively, of exposed animals of both species. In contrast, the liver did not show increased cadmium levels in exposed mice or rats. The data suggest that low-dose chronic inhalation exposure to cigarette smoke leads to highest cadmium accumulation in the lung, followed by the kidney, with minimal effects on cadmium levels in the liver.
Quarkonia and quark drip lines in a quark-gluon plasma

We extract the Q-Q potential by using the thermodynamic quantities obtained in lattice gauge calculations. The potential is tested and found to give spontaneous dissociation temperatures that agree well with those from lattice gauge spectral function analysis. Using such a Q-Q potential, we examine the quarkonium states in a quark-gluon plasma and determine the "quark drip lines" which separate the region of bound color-singlet Q Q states from the unbound region. The characteristics of the quark drip lines severely limit the region of possible bound Q Q states with light quarks to temperatures close to the phase transition temperature. Bound quarkonia with light quarks may exist very near the phase transition temperature if their effective quark mass is of the order of 300-400 MeV and higher.
Androgenic suppression of mouse hepatic FAD-containing monooxygenase activity

Abstract Sex-related differencesin the activity of hepatic FAD-containing monooxygenase (FAD-M) were found in C3H/St mice. Adult female mice had enzyme activities nearly two-fold greater than male mice and these, differences which were absent in sexually immature mice, became apparent at the onset of puberty. The sex differences in hepatic FAD-M appeared to be mediated through the suppressive effect of testosterone; castration of male mice enhanced enzyme activity, while androgenic replacement returned activities to control levels. Testosterone's suppressive effect was found to be relatively specific for hepatic FAD-M. Treatment of castrated male mice with both the anti-androgen flutamide and testosterone returned enzyme activity to control levels, suggesting that testosterone's regulation of hepatic microsomal FAD-M is receptor-mediated. Female gonadectomy had no effect on this enzyme's activity.
Double stranded DNA sequencing by tandem mass spectrometry

Abstract Electrospray ionization produces far more abundant molecular ions for double stranded (ds) DNA than for single stranded (ss) and accurate molecular masses can provide the base composition of dsDNA. This study shows that the Fourier-transform mass spectra of a ds 64-mer DNA can provide approximately 50% more sequence information than the spectra of either individual ss component. Cleavages triggered by T loss are of low probability, but the opposite is true in the complementary ss strand that bears the base A at this site. The spectrum of the product of the attempted biological synthesis of a ds 70-mer DNA provided critical information on its extensive 3′-end heterogeneity.
Big Fish in Little Ponds: A Multilevel Approach to Reputation in Organizations.

Research has traditionally considered the effects of corporate reputation, but less is known about the influence of individual and group reputation on important outcomes in the organization. This study uses a multilevel approach to explore the effects of having a high personal reputation in a group with a less favorable reputation (big fish in a little pond) or the alternative of having a low personal reputation in a group that is viewed more favorably (little fish in a big pond) on employee mobility. Results demonstrate the significance of employee engagement and identity in clarifying this relationship.
Mixed Tau and TDP-43 pathology in a patient with unclassifiable primary progressive aphasia

Classifying primary progressive aphasia (PPA) into variants that may predict the underlying pathology is important. However, some PPA patients cannot be classified. A 78-year-old woman had unclassifiable PPA characterized by anomia, dysarthria, and apraxia of speech without agrammatism. Magnetic resonance imaging revealed left mesial temporal atrophy and 18-flourodeoxy-glucose positron emission tomography showed left anterior temporal and posterior frontal (premotor) hypometabolism. Autopsy revealed a mixed tauopathy (argyrophilic grain disease) and transactive response-DNA-binding-protein-43 proteinopathy. Dual pathologies may explain the difficulty classifying some PPA patients and recognizing this will be important as new imaging techniques (particularly tau-positron emission tomography) are introduced and patients begin enrollment in clinical trials targeting the underlying proteinopathy.
Effects of nitrogen dioxide and ozone on monkey lung ultrastructure.

Pulmonary ultrastructural abnormalities were studied in squirrel monkeys exposed to 30 ppm NO2 or 3 ppm O3 for three hours with intermittent exercise. The lung tissues were processed either immediately after exposure or 1, 4 or 7 days later. Both the transmission and scanning electron microscopes were used for observation. Initial changes caused by the NO2 were the presence of fibrin in the alveoli, blebbing of the alveolar epithelium and the removal of cilia from the terminal bronchiolar epithelium. Seven days after exposure the tissues appeared to be recovering. Three ppm O3 was more damaging to alveoli than the 30 ppm NO2. The epithelial lining was degenerating or completely gone in many loci. Where intact, the width of the blood-air barrier increased with exposure and further with delay of sacrifice. Abnormal porosity of the alveolar walls was generally observed and remained through seven days after exposure. An unusual number of “paired” type 2 epithelial cells were present and contained a few to many homogeneous spherical inclusions of medium density. The results observed indicate that quantitation of morphological changes will be possible even at ambient exposures of atmospheric pollutants.
Engineered Biosynthesis of Novel Polyketides: Regiospecific Methylation of an Unnatural Substrate by the tcmO O-Methyltransferase†

TcmO is an O-methyltransferase that methylates the C-8 hydroxyl to Tcm B3, a four-ring aromatic intermediate in the tetracenomycin biosynthetic pathway of Streptomyces glaucescens. The gene encoding this enzyme was expressed in Streptomyces coelicolor CH999 together with the actinorhodin polyketide synthase (PKS) gene cluster, which is responsible for the biosynthesis of 3,8-dihydroxy-methylanthraquinone carboxylic acid (DMAC) and its decarboxylated analog, aloesaponarin. The resulting recombinant strain produced approximately equal quantities of aloesaponarin and a new product but no DMAC. Spectroscopic analysis revealed that the novel polyketide was the 3-O-methylated analog of DMAC. An in vitro radioisotopic assay was developed for tcmO. The enzyme requires S-adenosylmethionine as a co-substrate. It has a Km of 3 microM and a kcat of 2.7 min-1 for DMAC. A series of monocyclic, bicyclic, and tricyclic aromatic compounds were also tested as candidate substrates in vitro. Remarkably, none was modified by tcmO within detectable limits of the assay. Together, these results highlight the interesting molecular recognition features of this enzyme. On one hand, there appears to be some flexibility in the number and structures of unreactive rings, since both Tcm and B3 and DMAC are good substrates. However, 6-methylsalicylic acid, a monocyclic analog of the reactive ring, is not recognized by the enzyme. Likewise, neither aloesaponarin (which only differs from DMAC in the reactive ring) nor carminic acid (which only differs in the distal nonreactive ring) is modified. Thus, the binding energy for the tcmO-catalyzed methyl transfer appears to involve significant contributions from both the aromaticity and the functionality of polycyclic substrates.
Exploring the breadth of the top-down representations that control attentional disengagement

Recent studies attribute top-down control as the primary determinant of the speed with which attention can be disengaged from an object, and disengagement has received increased interest as a means to distinguish between top-down and bottom-up accounts of attention capture. We present the results of three experiments exploring the breadth of the representations that delay attentional disengagement based on top-down goals. Experiments 1 and 2 examined whether objects similar to an observers' search target, but differing in luminance and hue, delayed the reallocation of attention in a search paradigm designed to isolate disengagement time. Experiment 3 explored whether the representations that delay disengagement are based on absolute similarity with the search target, or are tuned based on target/nontarget relationships. These three studies confirmed the role of top-down goals in automatically contributing to dwell times and revealed that the representations that underlie disengagement effects are broad (a...
Impaired visual search in drivers with Parkinson's disease.

OBJECTIVE: To assess the ability for visual search and recognition of roadside targets and safety errors during a landmark and traffic sign identification task in drivers with Parkinson's disease (PD). METHODS: Seventy-nine drivers with PD and 151 neurologically normal older adults underwent a battery of visual, cognitive, and motor tests. The drivers were asked to report sightings of specific landmarks and traffic signs along a four-lane commercial strip during an experimental drive in an instrumented vehicle. RESULTS: The drivers with PD identified significantly fewer landmarks and traffic signs, and they committed more at-fault safety errors during the task than control subjects, even after adjusting for baseline errors. Within the PD group, the most important predictors of landmark and traffic sign identification rate were performances on Useful Field of View (visual speed of processing and attention) and Complex Figure Test-Copy (visuospatial abilities). Trail Making Test (B-A), a measure of cognitive flexibility independent of motor function, was the only independent predictor of at-fault safety errors in drivers with PD. INTERPRETATION: The cognitive and visual deficits associated with PD resulted in impaired visual search while driving, and the increased cognitive load during this task worsened their driving safety. Language: en
Regional variations in male and female unemployment.

The regional correlates of male and of female unemployment rates in 1980 and 1990 were different, with rates for females, but not for males, associated with worse socioeconomic conditions, such as high infant mortality and homicide rates. Language: en
Tip of the tongue and feeling of knowing experiences: A developmental study of memory monitoring.

WELLMAN, HENRY M. Tip of the Tongue and Feeling of Knowing Experiences: A Developmental Study of Memory Monitoring. CHILD DEVELOPMENT, 1977, 48, 13-21. Kindergarten, first-, and third-grade children were presented depicted items and asked to name them. For each item they could not name they were asked to judge: (a) if they felt they knew the name and so would be able to recognize it, and (b) if they had seen the depicted item before. Recognition for names was subsequently tested. In relation to a, accuracy of predicted recognition increased with age. In relation to b, judgments of having seen the item were very accurate predictors of recognition at all ages. It was concluded that though younger subjects were poor at predicting future recognition, they had available relevant information for the task. Poor performance resulted from not using the relevant information as a basis for the predictions. The conclusions were related to the concept of memory monitoring.
Short-term effects of rain on soil respiration in two New England forests

To gain new insights into the underlying mechanisms responsible for wetting-induced soil respiration, rain simulation field experiments were carried out in two temperate mixed-hardwood forests in New England (Great Mountain Forest and Harvard Forest). The rain-induced CO2 pulses were observed in both xeric and mesic soils. The pulse intensity was negatively correlated with the site moisture level and the pre-rain soil CO2 flux. At both forests, plots without O horizon responded to wetting with limited or even negative enhancement, confirming previous finding that the rain pulse was likely due to enhanced microbial consumption on substrates mainly of microbial origin. Our results show that the flux rain pulse was a reproducible phenomenon not limited to dry soils.
Urovirulence determinants in Escherichia coli isolates causing first-episode and recurrent cystitis in women

To assess the prevalence of urovirulence determinants among Escherichia coli isolates from women with acute uncomplicated cystitis, 121 isolates from 87 women with first-episode or recurrent cystitis and 156 fecal isolates from 52 women without recent urinary tract infection were tested using DNA probes for P fimbriae, hemolysin, aerobactin, and diffuse adhesin and for expression of hemolysin and P and F adhesins. P fimbrial genotype (P = .002), hemolysin phenotype (P = .007), and the diffuse adhesin determinant (P = .03), but not aerobactin, were found more frequently in E. coli from women with acute cystitis, and expression of the F adhesin (41%) was more common than the P adhesin (24%; P = .001). E. coli isolates that caused cystitis in women using diaphragms had fewer virulence determinants than those from nonusers (P = .04), suggesting that diaphragm use may allow infection with less virulent E. coli.
Results from a pilot clinical trial of varenicline for the treatment of alcohol dependence

Background Alcohol use, abuse and dependence remain a pressing public health problem. Based on its mechanism of action, varenicline seemed to be a likely candidate for treating alcohol dependence.
Photosynthetic Consequences of Late Leaf Spot Differ between Two Peanut Cultivars with Variable Levels of Resistance

Late leaf spot (LLS) caused by Cercosporidium personatum (Berk. & Curt.) Deighton reduces leaf CO 2 assimilation rate (A sat ) and accelerates leaf defoliation, which together lead to major reduc- tions in peanut (Arachis hypogaea L.) yield world- wide. This study was conducted to determine whether differences in photosynthetic response to LLS severity exist among peanut cultivars of differing resistance. Field experiments were con- ducted in 2008 and 2009 to study the effects of LLS on A sat of tagged leaf cohorts, and photo- synthetic response of similar age leaves to LLS in peanut cultivars with more (York) and less (Carver) quantitative resistance. A nonlinear model, y = (1 − x) β was used to analyze A sat data, where y is relative A sat , x is measured visual lesion area, and β represents the relationship between virtual and visual lesion area. Progression of LLS severity on leaf cohorts was slower in York than in Carver. However, the reduction in A sat with leaf cohort age was similar across the cultivars. This paradox could be explained by a higher β value in York (4.6) than in Carver (3.6), indicating a greater relative reduction in A sat beyond the necrotic lesion area in York. This greater reduction in A sat in York compared to Carver was most closely related to a reduction in maximum carboxylation velocity. Results indicated that future efforts to improve LLS resistance should include sustain- ing A sat in response to LLS infection along with slower disease progress.
Minimum altitude‐loss soaring in a sinusoidal vertical wind distribution

Minimum altitude-loss flight of a sailplane through a given vertical wind distribution is discussed. The problem is posed as a non-linear optimalcontrol problem, and several numerical solutions are obtained using a gradient projection algorithm. The initial and final states are required to be equal, though they may be either fixed or free. An unexpected new optimal trajectory type is found to exist for relatively short ranges and free boundary conditions.
Practices of High Reliability Teams: Observations in Trauma Resuscitation:

This paper reports findings on some of the practices adopted by teams based on interviews and observations of teams working in trauma resuscitation. This study was conducted at a level I trauma center over a period of six months. Although analysis of interview transcripts is on-going, these practices can be tentatively organized into several general themes: learning and trusting other roles, sharing responsibilities, ensuring team awareness, and being adaptive. In particular, even though membership of teams in trauma resuscitation is fluid and dynamic, by sharing the overall responsibilities for the well-being of the patient, the teams are able to resist many failure factors.
Periodicities of neurons controlled by slowly adapting cutaneous inputs in somatosensory thalamus of the cat.

Abstract We have studied ventrobasal thalamic neurons with rhythmic ongoing discharge patterns that change in response to steady cutaneous stimulation. Activity consisted of one or a burst of discharges recurring with periods of 61 to 184 msec and other discharges unrelated to the period. Some neurons showed coefficients of variation for events that were similar to those of type II mechanoreceptors. The site of generation of the periodic component was tested by comparing the effects of stimuli evoking neuron responses from different levels of the somatosensory system. Rhythmic activity was retimed by stimuli delivered at the level of primary afferents (skin or median nerve, less often C1–C2 dorsal columns) but not at the level of midbrain tracts or SI projection cortex. Repeated injections of barbiturate caused progressive reductions of mean firing rates but not corresponding changes of the periods. Periodic firing usually continued, with failures, until firing became infrequent. The results suggest that the periodic components arise from individual receptors, probably type II mechanoreceptors, that drive the thalamic neurons through powerful synaptic relays. Some neurons showed a second, usually less prominent periodic component, suggesting convergence of at least one additional rhythmic afferent fiber. We conclude that tonic activity of one or two single cutaneous receptors may be selectively transmitted to sensory cortex in the form of the periodic components and that activity in other convergent afferent fibers may be signaled by an aperiodic component.
Semi-classical scattering from a complex nuclear potential

Abstract A three-dimensional semi-classical treatment of scattering from a complex nuclear potential is given and its relation to the classical formulation of Eisberg, McCarthy and Spurrier 1 ) is shown. A three-dimensional effect which is lost in their approximation and which takes into account the derivatives of the potential transverse to the classical trajectories is explicitly indicated and evaluated for the uniform case. This correction, proportional to the ratio of the curl of the flux to the flux itself, tends to decrease the discrepancy found between the classical and quantal values of the divergence of the flux; but for those regions of the nucleus where the discrepancy and the corrections are large, the validity of the semi-classical and therefore the classical approximation breaks down, and consequently a discrepancy is not unexpected.
Efficacy of the Ivomec SR Bolus for Control of Horn Flies (Diptera: Muscidae) on Cattle in South Texas

The concentration of ivermectin in the serum of Hereford heifers treated with a single Ivomec SR bolus reached a maximum of 8.8 ± 0.9 ppb at 2 wk post-treatment. The single bolus treatment resulted in <10% mortality of adult horn flies feeding on the blood of the treated animals over the 21-wk trial. Bioassays of the manure from treated cattle showed complete inhibition of development of immature horn flies through week 19 post-treatment. When the trial was repeated using two Ivomec SR boluses/heifer, the concentration of ivermectin in the serum of the treated cattle reached a maximum level of 31.2 ± 3.9 ppb at week 13 post-treatment. During the first 17 wk of treatment, the use of two boluses/heifer resulted in 96.2 and 81.2% mortality of adult male and female horn flies feeding on the blood of treated animals, respectively. From these studies, we conclude that a single Ivomec SR bolus used as an anthelmintic treatment can be expected to provide significant control of immature horn flies developing in the manure, but not of adults feeding on the treated cattle.
Localization of immunoreactive glutamyl aminopeptidase in rat brain. I. Association with cerebral microvessels.

Abstract Glutamyl aminopeptidase (aminopeptidase-A, EC 3.4.11.7) is an ectoenzyme that selectively hydrolyses N-terminal glutamyl and aspartyl residues from oligopeptides, including (Asp1)angiotensin II. Here we sought to determine the distribution of glutamyl aminopeptidase (EAP) in rat brain. EAP was purified to homogeneity from rat kidney and polyclonal antiserum raised in rabbits. Immune serum inhibited EAP enzyme activity in kidney homogenates and labeled two major protein bands of Mr ≈ 136,000 and Mr = 101,000 in immunoblots of kidney protein. EAP-like immunoreactivity was concentrated on kidney proximal tubule brush borders. Immunocytochemical staining of rat brain indicated that EAP-like immunoreactivity was primarily associated with cerebral microvessels. Positive staining was detected in microvessels ranging in size from capillaries up to vessels approximately 50 μm in diameter. Isolated cerebral microvessels had a 23-fold enrichment in EAP enzyme activity (193.1 ± 40.4 nmol/mg protein/h) compared to brain homogenate. Finally, immunoblots of isolated cerebral microvessels resulted in a pattern of labeling similar to that seen with kidney homogenates. These results indicate that EAP activity in brain is primarily associated with cerebral microvessels, and suggest that EAP may be involved in the metabolism of circulating or locally formed peptides.
On Massive neutron cores

It has been suggested that, when the pressure within stellar matter becomes high enough, a new phase consisting of neutrons will be formed. In this paper we study the gravitational equilibrium of masses of neutrons, using the equation of state for a cold Fermi gas, and general relativity. For masses under $\frac{1}{3}\ensuremath{\bigodot}$ only one equilibrium solution exists, which is approximately described by the nonrelativistic Fermi equation of state and Newtonian gravitational theory. For masses $\frac{1}{3}\ensuremath{\bigodot}lml\frac{3}{4}\ensuremath{\bigodot}$ two solutions exist, one stable and quasi-Newtonian, one more condensed, and unstable. For masses greater than $\frac{3}{4}\ensuremath{\bigodot}$ there are no static equilibrium solutions. These results are qualitatively confirmed by comparison with suitably chosen special cases of the analytic solutions recently discovered by Tolman. A discussion of the probable effect of deviations from the Fermi equation of state suggests that actual stellar matter after the exhaustion of thermonuclear sources of energy will, if massive enough, contract indefinitely, although more and more slowly, never reaching true equilibrium.
Turbulent separation associated with axisymmetric flared bodies.

Flared afterbody aerodynamic characteristic predictions for aircraft stability at high Mach numbers, discussing turbulent separation
The global engine that could

It has been widely accepted since Carnot's seminal work ( 1 ) that the atmosphere acts as a thermodynamic heat engine: Air motions redistribute the energy gained from the Sun in the warm part of the globe to colder regions where it is lost through the emission of infrared radiation to space. Through this process, some internal energy is converted into the kinetic energy needed to maintain the atmospheric circulation against dissipation. The analogy to a heat engine has been applied to explain various atmospheric phenomena, such as the global circulation ( 2 ), hurricanes ( 3 ), and dust devils ( 4 ). On page 540 of this issue, Laliberte et al. ( 5 ) show that the hydrological cycle reduces the efficiency of the global atmospheric heat engine.
Dynamic Lagrangian dual and reduced RLT constructs for solving 0-1 mixed-integer programs

In this paper, we consider a dynamic Lagrangian dual optimization procedure for solving mixed-integer 0–1 linear programming problems. Similarly to delayed relax-and-cut approaches, the procedure dynamically appends valid inequalities to the linear programming relaxation as induced by the Reformulation-Linearization Technique (RLT). A Lagrangian dual algorithm that is augmented with a primal solution recovery scheme is applied implicitly to a full or partial first-level RLT relaxation, where RLT constraints that are currently being violated by the primal estimate are dynamically generated within the Lagrangian dual problem, thus controlling the size of the dual space while effectively capturing the strength of the RLT-enhanced relaxation. We present a preliminary computational study to demonstrate the efficacy of this approach.
Efficacy of a Gender and Ethnic Equity in Science Education Curriculum for Preservice Teachers.

The purpose of the Gender and Ethnic Equity in Science Education (GEESE) program, conducted during the student-teaching semester, was to provide preservice science teachers with the opportunity to use clinical observations and reflection as vehicles for discovery of the disparate school experiences of the diverse students in their science classrooms. The preservice teachers examined curricular materials in use during their practicum, student and teacher behaviors, the quantity and quality of student–teacher interactions, and grouping and evaluative strategies before attempting self-analysis at the conclusion of the program. Interviews were used as the source of qualitative evidence of change in the preservice teachers' attitudes and teaching behaviors. While students approved of the program initially, they eventually dismissed issues of gender and ethnic equity as critical once they began struggling with the inadequate academic preparation of their students and scant material resources. Ultimately, the preservice teachers identified the GEESE program as useful in that it provided them with specific critical techniques, but inappropriately placed at the conclusion of their professional development sequence. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 1019–1038, 1997.
Semi-mojo, or Shaft in Scarsdale: Michael Rogin and Comparative American Studies

Michael Rogin's Blackface, White Noise (1996) brought the institutional racial unconscious of the entertainment industry into the light. Ten years on, and six years after the author's death, this essay celebrates its publication by looking at some of the ways the book helps illuminate cultural artefacts and productions from Joe Klein's roman a clef Primary Colors (1996) to the music of Steely Dan. Rogin's book is a reminder of the thorny social and cultural relations between Jewish-Americans and African-Americans that scholars sometimes too easily wish away.
Efficacy of Caffeic Acid Phenethyl Ester (CAPE) in skin B16-F0 melanoma tumor bearing C57BL/6 mice

In current work, we investigated the in-vitro efficacy of Caffeic acid Phenethyl Ester (CAPE) as an anti-melanoma agent in five melanoma cell lines B16-F0, B16F10, SK-MEL-28, SK-MEL-5, and MeWo and in-vivo efficacy study in skin B16-F0 melanoma tumor model in C57BL/6 mice. The IC50 (48 h) of CAPE in above five melanoma cell lines was 15 µM. CAPE (20–200 µM) led to intracellular GSH depletion of 16–54%, and 10–25 fold increase in Reactive Oxygen Species (ROS) formation in B16-F0 cells. CAPE (15–30 µM) caused 5–7 fold increase in apoptosis in B16-F0 cells. CAPE (10, 20 and 30 mg/Kg/day) led to tumor size growth inhibition by 39 ± 33%, 54 ± 36%, and 57 ± 18%, respectively. The respective therapies led to plasma Alanine Amino Transferase (ALT) levels corresponding to 85 ± 18, 107 ± 26, 154 ± 35 IU/L in comparison to controls 66 ± 14 IU/L. At corresponding doses, the lipid peroxidation levels as measured by malondialdehyde (MDA) formation in liver homogenates were 255 ± 8 μM, 304 ± 21 μM, and 342 ± 14 μM in comparison to 208 ± 6 μM in controls. The level of MDA in kidney homogenates was 263 ± 21 μM, 282 ± 18 μM, and 350 ± 28 μM, respectively, in comparison to 212 ± 8 μM in controls. Administration of CAPE (10, 20, 30 mg/Kg/day) diminished free thiol contents in liver for 21 ± 15%, 40 ± 17%, and 44 ± 19% and in kidney homogenates for 25 ± 15%, 37 ± 18%, and 40 ± 22%, respectively, as compared to controls. Our study suggests that CAPE at 10 mg/Kg/day has significant anti-melanoma efficacy with minimal toxicity.
Heavy-ion-induced single- and double-strand breaks in phiX-174 replicative form DNA

SummaryDamage caused by accelerated atomic nuclei was measured in ΦX-174 Replicative Form I (RF I) DNA as a function of linear-energy transfer (LET). Irradiations were performed at room temperature in a highly radioprotective broth to minimise the effects of free radicals. Most ion beams terminated in the continuously-mixed samples. By using neutral sucrose gradient sedimentation of 3H-TdR-labelled RF DNA, irradiated samples were assayed for relative proportions of RF I (supercoil), RF II (open coil), and RF III (linear) DNA configurations. A spheroplast assay was used to determine the viability of DNA samples. The efficiency of production (per rad) of single-strand break events decreased three-fold over the LET range investigated, whereas double-strand break production increased five-fold. The ratio of single-strand break events to double-strand breaks varied from about 26 : 1 for 60Co gamma-irradiation, to about 2 : 1 for oxygen-ion irradiation. Double-strand breaks accounted for less than 10 per cent o...
Translational correlations in the vortex array at the surface of a type-II superconductor.

We discuss the statistical mechanics of magnetic flux lines in a finite-thickness slab of type-II superconductor. The long-wavelength properties of a flux-line liquid in a slab geometry are described by a hydrodynamic free energy that incorporates the boundary conditions on the flux lines at the sample's surface as a surface contribution to the free energy. Bulk and surface weak disorder are modeled via Gaussian impurity potentials. This free energy is used to evaluate the two-dimensional structure factor of the flux-line tips at the sample surface. We find that surface interaction always dominates in determining the decay of translational correlations in the asymptotic long-wavelength limit. On the other hand, such large length scales have not been probed by the decoration experiments. Our results indicate that the translational correlations extracted from the analysis of the Bitter patterns are indeed representative of behavior of flux lines in the bulk.
CI-Miner: semantically enhancing scientific processes

The realization of an international cyberinfrastructure of shared resources to overcome time and space limitations is challenging scientists to rethink how to document their processes. Many known scientific process requirements that would normally be considered impossible to implement a few years ago are close to becoming a reality for scientists, such as large scale integration and data reuse, data sharing across distinct scientific domains, comprehensive support for explaining process results, and full search capability for scientific products across domains. This article introduces the CI-Miner approach that can be used to aggregate knowledge about scientific processes and their products through the use of semantic annotations. The article shows how this aggregated knowledge is used to benefit scientists during the development of their research activities. The discussion is grounded on lessons learned through the use of CI-Miner to semantically annotate scientific processes in the areas of geo-sciences, environmental sciences and solar physics: A use case in the field of geo-science illustrates the CI-Miner approach in action.
General purpose symbolic simulation tools for electric networks

Research results on the use of computers to solve simulation problems in a way closer to human thinking are reported. With the aid of techniques in artificial intelligence, database systems, and computer graphics, a set of general-purpose Lisp and Pascal based simulation tools have been developed. Each of these tools solves a specific problem in some stage of simulation. Rule-based and object oriented symbolic manipulations are extensively used. The tools provide more powerful and accurate modeling capability for complex objects, and permit simplicity and flexibility in implementation. They are used to study electrical transient problems, optimal load flow problems, linear control systems, and other simulation problems. >
Carbon sink to source: longitudinal gradients of planktonic P:R ratios in subtropical reservoirs

Spatial patterns of planktonic production and respiration in the surface mixed layer were examined in eight Texas, USA reservoirs to test the hypothesis that P:R ratios are lowest in upreservoir inflow zones and highest in downreservoir open-water zones, as predicted by the heuristic reservoir zonation model. We measured summer planktonic metabolism with light–dark bottles and physical–chemical conditions in epilimnetic water at 85 sites distributed among sixteen longitudinal transects within the eight reservoirs (2 transects per reservoir). Volumetric production and plankton biomass were lowest in the open-water zones and increased upreservoir; however, that pattern was reversed for areal production due to greater photic depths at open-water sites. Volumetric respiration was similar in the three zones; however, corresponding planktonic P:R ratios in the surface mixed layer were significantly lower at open-water sites, which is opposite than hypothesized. Based on linear regressions of production and respiration rates on chlorophyll a, open-water sites were net heterotrophic during the summer regardless of trophic state; whereas inflow and mid-reservoir zone sites were heterotrophic when chlorophyll concentrations were respectively less than 9.5 and 35 mg m−3. Although variation among reservoirs was high, five of the eight reservoirs had inflow zones that were net carbon sinks while seven had open-water zones that were carbon sources. Mean (±standard error) carbon flux rates of inflow, mid-reservoir, and open-water zones were −0.22 ± 0.12 (C sink), 0.39 ± 0.44 (moderate C source), and 1.33 ± 0.50 (strong C source) g C m−2 day−1 respectively. Inflow and mid-reservoir zones comprised approximately 45% of the total reservoir area studied. Therefore, omitting their contribution as often done when a single open-water site is sampled may substantially overestimate reservoir carbon flux.
Clay–starch composites and their application in papermaking

Clay–starch composites with different aggregate sizes and starch to clay ratios were prepared by a simple precipitation method. The aggregates of the composites were used as fillers to improve the paper properties. The experimental results showed that the paper strengths increased more than 100% for starch-modified clay compared to untreated clay at 20–30% clay loading. The increase in paper strengths of clay–starch composite-filled handsheets was mainly due to two reasons, i.e., the relatively large aggregate size and the improved internal bonding. The optical properties compared at same mechanical strength were also improved. The water solubility of starch in the clay–starch composite was less than 3% at 50°C for 30 min, and it could be further reduced by adding crosslinker. Bonding sites between composite and fiber were investigated by scanning electron microscope. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1032–1038, 2006