cssi/SciSciGPT-SciSciNet huggingface dataset:
The acetylcholine receptor and the ionic conductance modulation system of skeletal muscle.

In attempting a molecular analysis of the events involved in the chemical transmission of an impulse, we have selected the vertebrate motor endplate as a model synapse. Ultrastructural localization of certain functional molecules involved there reveals that the acetylcholine (ACh) receptor is concentrated at the crests of the postjunctional folds at a constant density of 20,000–25,000/μm2 of membrane while, by contrast, cholinesterase sites are distributed evenly along the folds. This evidence, together with that from other laboratories, has led to the construction of an endplate model showing the spatial arrangement of transmitter release in relation to ACh receptor and acetylcholinesterase concentrations. By several approaches, the end-plates of different species and muscle types are found to have a fixed number of ACh receptors ranging from 107 to 108 per endplate. Of these, over 90% are now considered to be true ACh receptors as based on their affinity for d-tubocurarine. Interestingly, the maximum sensitivity values for ACh, applied microiontophoretically to these same muscle types, all tend to be in the same range—5000 to 8000 mv/nc. It therefore appears that the endplate response to ACh is determined by the density of receptors along the post-junctional membrane and not by the total number at the endplate. From several considerations, we deduce that this density of receptor sites cannot be saturated by ACh during normal transmission. The correlation of electrophysiological data with quantitative molecular parameters, from these and other laboratories, indicates that the maximum endplate sensitivity to externally applied ACh (∼ 7000 mv/nc) is equivalent to an efficiency of about 12% of that of neurally released transmitter. By similar analysis, a one-to-one or two-to-one relationship for the ACh receptor and the ionic conductance modulation system has been derived, implying that the two may be linked as such in the membrane. ACh receptor, having an apparent molecular weight of about 370,000 (in 0.2% Triton X-100), has been solubilized and purified from denervated muscle.
Bioassay procedure for the evaluation of erythromycin activity in aquaculture environments.

A new bioassay procedure was developed for the detection of erythromycin in aquaculture samples using a strain of a Stenotrophomonas as an indicator organism. Conventional disk-plate and well-plate radial diffusion assay procedures were developed, as well as a third procedure using the same indicator organism in Luria-Bertani (LB) broth, supplemented with the indicator dye Brilliant Black (40 μg/mL) in a multi-well microtiter plate. For both the disk-plate and well-plate radial diffusion assays, the response reflected in the size (width) of the growth inhibition zone, which was linear over the tested concentration range of 0.05 to 2.0 μg erythromycidml. The limit of quantitation of the bioassay was at 0.05 μg erythro-mycidml. Among the three methods of assay tested with Stenotrophomonas sp., the semi-quantitative dye reduction method is easy to read and is not diffusion dependent. This method allows for processing of more samples and more replication on a single titer plate. This new indicator organism is specific for erythromycin when tested in the presence of other antibacterial agents, i.e., oxytetracycline (Terramycin®) and/or Romet-Ma. This new bioassay procedure is suitable for quantitation of low concentrations of erythromycin in aquaculture water and sediment samples.
BIOLOGICAL INTERVENTION BASED ON CELL AND GENE THERAPY TO IMPROVE MUSCLE HEALING AFTER LACERATION

Muscle laceration is a challenging problem in traumatology and is common in sports injuries, with functional recovery remaining slow and incomplete. Even though muscles retain their ability to regenerate after injury, muscles' healing process after such injuries has been found to be very slow and often leads to incomplete muscle recovery. Growth factors may have a role in enhancing recovery. Our previous study showed that IGF-1, β-FGF and NGF can improve myoblast proliferation and differentiation in vitro. We then investigated whether the delivery of IGF-1 would improve muscle healing after injuries. We observed that muscle regeneration was enhanced in lacerated muscles treated with IGF-1 protein, which consequently led to an improvement in muscle healing. However, the rapid clearance and short biological half-lives of these proteins may have limited the success of this approach. We then investigated the efficiency of gene therapy based on adenovirus to deliver a stable expression of the growth factor IGF-1. Although a slight improvement in the healing process occurred in the muscle injected with adenovirus (AIGF), the combination of myoblast transplantation and gene therapy with the ex vivo approach further improved the healing process. The injection of normal myoblasts into the injured muscle led to the best improvement of muscle healing at two weeks post-injection. Implantation of normal minced muscle into mdx mice was also capable of improving muscle healing at 2–4 weeks post-implantation. These studies will further our understanding of muscle healing post-injury and help in the development of strategies to promote efficient muscle healing and complete functional recovery after common muscle injuries.
THE DYE-SENSITIZED PHOTOOXIDATION OF PURINE AND PYRIMIDINE DERIVATIVES.

Abstract In the presence of light and methylene blue (MB), a reaction leading to the loss of ultraviolet absorbance accompanied by the uptake of 1 mole O 2 per mole substrate occurs with guanine derivatives. The wavelengths of light that are most effective are those that are absorbed by the sensitizer; MB acts in a catalytic fashion i.e., it is not required in stoichiometric amounts; and the reaction follows first-order kinetics. The anionic form of the guanine nucleoside is about 25 times more reactive than the neutral species. A number of dyes that are active in other photodynamic reactions also sensitize the reaction of guanine derivatives and have little or no effect on the other bases which occur in DNA and RNA. Other derivatives were examined for their ability to be photooxidized by MB, and a product of the reaction of theophylline was isolated and identified as 1,3-dimethylallantoin.
The new drug approvals of 1987, 1988, and 1989: trends in drug development

The new drug approvals of 1987, 1988, and 1989 were analyzed to determine whether there are any emerging trends in the US drug development and review processes. Sixty-four new drugs were approved by the FDA during this period, of which 55 met the Center for the Study of Drug Development's definition of a new chemical entity (NEC). For the 55 NCEs, the mean length of the investigational new drug application (IND) phase (IND filing to NDA submission) was 5.2 years, the new drug application (NDA) phase (NDA submission to approval) was 2.9 years, and the total phase (IND filing to NDA approval) was 8.1 years. Nine of the 55 NCEs were classified by the FDA as 1A (important therapeutic gain), 15 were classified as 1B (modest gain), 29 were classified as 1C (little or no gain), and 2 were classified as 1AA (drugs to treat AIDS and AIDS-related conditions); 10 drugs were granted orphan status. The mean NDA phase for 1A drugs was 2.4 years; 1B drugs, 2.9 years; 1C drugs, 3.1 years; 1AA drugs, 1.4 years; and orphan drugs, 2.5 years. Forty-four of the 55 NCEs (80%) were available in foreign markets before US approval was given, with a mean of 6.5 years of prior marketing. These data are consistent with figures for previous years and suggest little change in the rate of new drug development and review in the United States.
Hybrid user preference models for second life and opensimulator virtual worlds

Virtual world user models have similarities with hypertext system user models. User knowledge and preferences may be derived from the locations users visit or recommend. The models can represent topics of interest for the user based on the subject or content of visited locations, and corresponding location models can enable matching between users and locations. However, virtual worlds also present challenges and opportunities that differ from hypertext worlds. Content collection for a cross-world search and recommendation service may be more difficult in virtual worlds, and there is less text available for analysis. In some cases, though, extra information is available to add to user and content profiles enhance the matching ability of the system. In this paper, we present a content collection system for Second Life and OpenSimulator virtual worlds, as well as user and location models derived from the collected content. The models incorporate text, social proximity, and metadata attributes to create hybrid user models for representing user interests and preferences. The models are evaluated based on their ability to match content popularity and observed user behavior.
A search for a shift in the transverse electromagnetic mass of the electron

Abstract An experimental search was made for a frequency shift produced by conducting-plate confinement of the cesium beam in an atomic clock. The ratio of experimental to theoretical plate separation dependence is -0.023 ± 0.036, consistent with no shift.
Predictive markers in breast cancer: An update on ER and HER2 testing and reporting

Gene expression profiling of human tumors has provided a new paradigm for classifying breast carcinomas, predicting response to treatment, and risk of recurrence. Estrogen receptor (ER), human epidermal growth factor 2 (HER2) receptor, and proliferation-related genes are the main drivers of classification in many of the gene expression profiling tests for breast cancer. However, ER, progesterone receptor (PR), and HER2 receptor status remain essential in determining the need and type of adjuvant therapy. These biomarkers are routinely tested for in all invasive breast carcinomas; ER testing is also performed on cases of ductal carcinoma in situ (DCIS). This article will provide an update on current guidelines from the American Society of Clinical Oncologists (ASCO) and the College of American Pathologists (CAP) for ER and HER2 testing by immunohistochemistry (IHC) and in situ hybridization (ISH). The populations to be tested, antibody selection, criteria for interpretation, and reporting are discussed. The molecular alterations that correlate with IHC results, alternative methods of testing, and the current approach to complex aspects of HER2 testing, including heterogeneity and polysomy, also are summarized.
Phonon Imaging of Highly Dislocated LiF

It has been found that high-frequency acoustic phonons with certain polarizations can propagate ballistically through a highly deformed LiF crystal. With use of the method of phonon imaging, a large anisotropy has been observed in the phonon-dislocation interaction: the crystal acts as a phonon polarizer. The data are consistent with the fluttering dislocation-model. Phonon focusing and anisotropic-scattering processes profoundly affect the transport of heat through a dislocated crystal.
GLASS: THE BOND IN CERAMICS*

A ceramic industry is one which manufactures products by the application of heat to raw materials containing silica or silicates as essential ingredients, and ceramic chemistry is that branch of Chemistry which deals with the chemistry of silica. The property which makes silica the basis of industries as apparently diverse as water glass and refractories and which is conferred on all mixtures in which it is present in adequate amounts is that of forming glasses. While silica itself forms an ideal glass, its high melting point requires the addition of a flux, and the commonest and most powerful flux is soda. The addition of soda to silica produces a remarkable lowering of the melting point, from 1713 to 793° and glass of this composition is remarkably stable against devitrification. It is dissolved by water and forms the basis for the soluble silicate industry. But insolubility in water and acids is essential for most of the glasses of ceramics, and other oxides must be added to obtain this stability. The commonest and cheapest is lime (CaO), and most of the glass of commerce may be regarded as derived from the sodium-silicate glass by the addition of several per cent of lime, usually also with the addition of small amounts of other oxides, notably magnesia, boric oxide, and alumina. Boric oxide and alumina are especially characteristic of the glassy base of enamels, which chiefly differ from glasses in containing insoluble materials to render them opaque and often coloring agents soluble in the glassy phase. Glazes, too, are of similar composition. Refractories are bonded by glass; either a lime glass in the silica refractories, or an aluminum glass in the clay refractories. But a siliceous glass is the characteristic feature which is found in all products of the ceramic art, and glass is the bond which unites the divers ceramic industries.
Malignant renal tumors intuberous sclerosis

Although the frequency of renal carcinoma in tuberous sclerosis is lower than that in von Hippel-Lindau syndrome, it occurs bilaterally in 43 percent of patients at a median age of twenty-eight years. Concomitant hamartomas and hyperplastic cystic components may confound the histologic diagnosis of renal carcinoma in tuberous sclerosis.
Catheter-based decompression of the left atrium in patients with hypoplastic left heart syndrome and restrictive atrial septum is safe and effective.

Infants with hypoplastic left heart syndrome (HLHS) and restrictive or intact atrial septum (rAS) present with cyanosis, pulmonary edema, and are critically ill. A previous report from our institution on emergent Norwood for HLHS with rAS showed 10% survival. We hypothesized that transcatheter left atrial (LA) decompression in HLHS with rAS would safely and effectively relieve LA hypertension, improve oxygenation, and improve Norwood survival. Between 1996 and 2004, 30 patients with HLHS and rAS underwent cardiac catheterization for pre-Norwood intervention. Twenty-eight atrial septostomies were performed: 23 static balloon dilations, 4 Rashkind septostomies, and 1 intra-atrial stent. Two procedures were aborted due to perforation (n = 1) or inability to enter the LA (n = 1). Eight total patients required surgical septectomy, for a failure rate of 27%. There were no catheter-related mortalities, although two patients died within 36 hr of the procedure after surgical septectomy. Major complications occurred in three patients (10%)—atrial perforations requiring intervention. Mean atrial septal defect gradient fell from 16.7 ± 4.9 to 6.3 ± 3.4 mm Hg (P < 0.001; n = 18). Mean LA pressure dropped from 21.8 ± 5.5 to 13.1 ± 6.5 mm Hg (P < 0.001; n = 16). Mean PaO2 rose from 29.5 ± 9.1 to 36.5 ± 5.1 torr (P < 0.001; n = 23). Seventeen of 30 patients (57%) survived to discharge from Norwood. Thirteen have undergone hemi-Fontan and nine Fontan. Sixteen of 22 successful decompressions (73%) survived to discharge. Transcatheter decompression of the LA for patients with HLHS and rAS can be performed safely, reduces the transatrial gradient, and improves oxygenation. Catheter intervention improves survival compared to historical controls undergoing emergent Norwood. © 2006 Wiley-Liss, Inc.
Recent Advances in Agglomerated Multigrid

We report recent advancements of the agglomerated multigrid methodology for complex flow simulations on fully unstructured grids. An agglomerated multigrid solver is applied to a wide range of test problems from simple two-dimensional geometries to realistic three- dimensional configurations. The solver is evaluated against a single-grid solver and, in some cases, against a structured-grid multigrid solver. Grid and solver issues are identified and overcome, leading to significant improvements over single-grid solvers.
The apolipoprotein(a) gene is regulated by sex hormones and acute-phase inducers in YAC transgenic mice

High plasma concentrations of apolipoprotein (a) (apo(a)) have been implicated as a major independent risk factor for atherosclerosis in humans. Apo(a) is a large, evolutionarily new gene (present primarily in primates) for which considerable controversy exists concerning the factors that regulate its expression. To investigate the in vivo regulation of apo(a), we have created several lines of YAC transgenic mice containing a 110-kb human apo(a) gene surrounded by greater than 60 kb of 5' and 3' flanking DNA. Studies in humans have suggested that acute-phase inducers increase and sex steroids decrease apo(a) concentrations, but these results are controversial. Analysis of the YAC transgenic mice conclusively supports the hypothesized role of sex steroids and refutes the suggested role of acute-phase inducers in regulating the apo(a) gene.
PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure

Polychlorinated biphenyls (PCBs) are persistent pollutants identified worldwide as human blood and breast milk contaminants. Because they bioaccumulate, consumption of meat, fish, and dairy products predicts human blood concentrations. PCBs were also used widely in building materials, including caulks and paints, but few studies have evaluated the contribution of these exposures to body burden. In an earlier study, we detected PCBs in indoor air in 31% of 120 homes on Cape Cod, MA. Two of the homes had much higher concentrations than the rest, so we retested to verify the initial finding, evaluate blood PCB concentrations of residents, and identify the PCB source. Air and dust concentrations remained elevated over 5 years between initial and follow-up sampling. Blood serum concentrations of PCBs in residents of the homes were generally elevated above the 95th percentile of a representative sample of the US population. Serum concentrations in residents and air and dust concentrations were especially high in a home where a resident reported use of PCB-containing floor finish in the past, and where the floor of one room was sanded and refinished just prior to sample collection. This case-study suggests that PCB residues in homes may be more significant contributors to overall exposure than diet for some people, and that use of a commercially-available PCB-containing wood floor finish in residences during the 1950s and 1960s is an overlooked but potentially important source of current PCB exposure in the general population.
Frenkel pairs on the two sublattices of ZnTe

Study of the polarization of a dominant 1.0 $\ensuremath{\mu}\mathrm{m}$ photoluminescence band produced by 2.5 MeV electron irradiation of ZnTe in situ at 4.2 K reveals it to arise from a Frenkel pair produced on the Zn sublattice. Optical detection of electron paramagnetic resonance (ODEPR) studies reveal Frenkel pairs on the Te sublattice. All pairs disappear in various annealing stages from 35 K to 120 K. The Te-sublattice pairs can also be made to disappear by optical injection at 1.5 K. Deconvoluting the Te interstitial contribution to the $S=1$ ODEPR spin Hamiltonian parameters leads to a model for it as ${\mathrm{Te}}_{i}^{\ensuremath{-}},$ which is only slightly distorted off-center from a ${T}_{d}$ interstitial site. The distortion, viewed as partially of Jahn-Teller origin, provides a logical explanation for its optically induced migration.
Measurements of output-dependent Preisach functions

The interiors of hysteresis loops were examined for commercial recording tape samples of gamma -Fe/sub 2/O/sub 3/ and Co-modified gamma -Fe/sub 2/O/sub 3/. It was found that the minor loops did not satisfy the congruency condition of the classical Preisach model. Since both the moving model and the product model are capable of describing minor loops whose height varies with the magnetization, they were used to analyze this data. It was found that the results were consistent with the expectations of the moving model and not with the product model. An identification method for the moving parameter is given. Two models for the reversible component of the magnetization that are compatible with the moving model are presented. >
Effect of tobacco mosaic virus infection on glucose metabolism in Nicotiana tabacum L. var. Samsum II. Investigation of malonic acid inhibition on respiration

Abstract The effect of malonic acid on the respiration rate of leaf tissue from tobacco mosaic virus (TMV)-infected and healthy N. tabacum L. var. Samsun plants was investigated. There were no statistically significant differences in malonic acid-induced respiratory inhibition between infected and healthy tissues, regardless of the time interval used for calculation or the presence of visual symptoms of infection
Surgical infections in the traumatized spine.

Patients with acute spinal injury who require operative intervention may be at increased risk for postoperative surgical-site infection when compared with patients having elective spinal surgery. Various local, systemic, and iatrogenic factors predispose this unique population of patients to post-su
Allozyme polymorphisms, outerossing rates, and hybridization of South AmericanNothofagus

Electrophoretically detectable genetic variation was used to describe the genetic structure of three South American species ofNothofagus: the widespreadN. betuloides andN. dombeyi, and the geographically restrictedN. nitida. Although the widespread species possess higher levels of genetic variation, the three species have more genetic variation within than among populations. These results are consistent with the theoretical expectations for woody, presumably highly outerossed species with wind-borne seeds. Estimates of outcrossing rates from progeny arrays yielded slightly higher average t-values forN. nitida (1.158) andN. dombeyi (range 0.873–1.045) than forN. betuloide (0.878). Hierarchical analysis of population structure revealed values of FIS and FIT that were positive and significantly different from zero at most loci and for each species. The levels of inbreeding detected by F-statistics indicate some degree of self-fertilization and/or population substructuring into discrete family groups. Reduced seed vagility and regeneration of natural stands after disturbance by a few remnant individuals would probably generate the recruitment of related seedlings underneath parent trees. The analysis of a putative hybrid population betweenN. nitida andN. betuloides indicated that individuals clearly segregated intonitida-like orbetuloides- like individuals. The reduced outcrossing rate ofbetuloides-like individuals from the hybrid site (t=0.585) is interpreted in concert with low pollen availability and the increased probability of selfing and/or hybridization inNothofagus.
Nuclear Data Sheets for 97Pd

Abstract Abstract: In this evaluation, the experimental data from a β-decay study of 97Ag (1999Hu10), in combination with the data available from the previous evaluation (Agda Artna-Cohen, Nuclear Data Sheets 70, 85 (1993)), were used to assign excitation energies, β-decay branching ratios, logft values, spins and parities to states in 97Pd. All γ transitions placed in the decay scheme of 97Ag β decay were only accepted if at least the coincidence with 511 keV γ-quanta was observed and both of the connecting levels were confirmed by other γ transitions.
SECURITY RETURN DISTRIBUTIONS AND MARKET STRUCTURE: EVIDENCE FROM THE NYSE/AMEX AND THE NASDAQ MARKETS

This paper documents significant and persistent deviations from normality in security return distributions for the NYSE, AMEX, and NASDAQ from 1974 to 1988. Controlling for January and size effects, we find that the deviations of security return distributions from normality decline with increasing portfolio size and investment horizon for the NYSE and AMEX, especially for daily returns. Deviations appear to be greater for the NASDAQ than for the two exchanges even for firms of the same size. Ratios of monthly to daily variances are also larger for the NASDAQ. These results suggest that nonparametric or other robust statistical techniques should be used when valuing equity options and other derivatives, especially when examining NASDAQ security returns. They further imply that trading strategies based on market inefficiencies are more likely to succeed on the NASDAQ.
Enduring changes in dopamine receptor cells of pups from drug administration to pregnant and nursing rats

A decrease in specific [3H]spiroperidol binding to rat caudate tissue and a parallel decrease in sensitivity to apomorphine in eliciting stereotyped behavior was observed in the offspring of rat mothers treated with either haloperidol or alpha-methyl-p-tyrosine-methyl ester during pregnancy. In contrast, evidence of increased dopamine-receptor sensitivity was observed in the pups if haloperidol was administered to their mothers postpartum during nursing rather than during pregnancy.
Structure and Function of the Sterol Carrier Protein-2 N-Terminal Presequence

Although sterol carrier protein-2 (SCP-2) is encoded as a precursor protein (proSCP-2), little is known regarding the structure and function of the 20-amino acid N-terminal presequence. As shown herein, the presequence contains significant secondary structure and alters SCP-2: (i) secondary structure (CD), (ii) tertiary structure (aqueous exposure of Trp shown by UV absorbance, fluorescence, and fluorescence quenching), (iii) ligand binding site [Trp response to ligands, peptide cross-linked by photoactivatable free cholesterol (FCBP)], (iv) selectivity for interaction with anionic phospholipid-rich membranes, (v) interaction with a peroxisomal import protein [FRET studies of Pex5p(C) binding], the N-terminal presequence increased SCP-2’s affinity for Pex5p(C) by 10-fold, and (vi) intracellular targeting in living and fixed cells (confocal microscopy). Nearly 5-fold more SCP-2 than proSCP-2 colocalized with plasma membrane lipid rafts and caveolae (AF488-CTB); 2.8-fold more SCP-2 than proSCP-2 colocalized...
A Factor in Human Plasma Permits Persistent Expression of E-Selectin by Human Endothelial Cells

Abstract E-selectin is an inducible endothelial cell adhesion protein that is a critical element in the binding of leukocytes to activated endothelial cells. It is induced by a variety of pro-inflammatory soluble substances including interleukin-1 (IL-1), tumor necrosis factor (TNF), or bacterial li- popolysaccharide (LPS). In vitro studies of large vessel endothelial cells demonstrate that stimulation with TNF or IL-1 leads to a rapid, but transient, induction of E-selectin expression that disappears within 24 hours. However, in vivo studies have shown that microvascular endothelial cells persistently express E-selectin in chronic inflammatory states, particularly in the skin where it serves as a homing receptor for memory T cells. Stimulation of dermal-derived microvascular endothelial cells (HDMECs) with single doses of IL-1α, TNF α, or LPS resulted in transient but slightly more persistent expression of E-selectin than seen after stimulation of large vessel derived umbilical vein endothelial cells (HUVECs). However, stimulation of either HDMECs or HUVECs with repetitive doses of IL-1α, TNFα, or LPS in the presence of human serum or plasma resulted in persistent E-selectin expression in vitro . The persistent E-selectin cell surface expression was associated with persistent E-selectin mRNA expression and correlated with E-selectin-mediated HL-60 binding to endothelial cell monolayers. The effect of human Vasma or serum was dose dependent, and fractionation of human plasma by gel filtration demonstrated that the E-selectin persistence activity resolved into high and low molecular peaks. These data demonstrate that human endothelial cells are capable of persistent E-selectin expression in vitro and that factors in human serum or plasma are critical in preventing cytokine refractoriness and loss of E-selectin expression. This study provides a basis to resolve the apparent discrepancies between previous in vivo and in vitro dynamics of E-selectin expression.
A state-space analysis of mechanical energy generation, absorption, and transfer during pedaling

Seated ergometer pedaling is a motor task ideal for studying basic mechanisms of human bipedal coordination because, in contrast to standing and walking, fewer degrees of freedom are being controlled and upright balance is not a factor. As a step toward understanding how individual muscles coordinate pedaling, we investigated how individual net muscle joint torques and non-muscular (e.g. centripetal, coriolis, and gravity) forces of the lower limbs generate, absorb, and transfer mechanical energy in order to propel the crank and recover the limb. This was accomplished using a mechanical power analysis derived entirely from the closed-form state-space dynamical equations of a two-legged pedaling model that accounted for both the limb segmental and crank load dynamics. Based on a pedaling simulation that reproduced experimental kinematic and kinetic trajectories, we found that the net ankle and hip extensor joint torques function 'synergistically' to deliver energy to the crank during the downstroke. The net hip extensor joint torque generates energy to the limb, while the net ankle extensor joint torque transfers this energy from the limb to the crank. In contrast, net knee extensor and flexor joint torques function 'independently' by generating energy to the crank through the top and bottom of the stroke, respectively. The net ankle joint torque transfers and the net knee joint torque generates energy to the crank by contributing to the driving component of the pedal reaction force. During the upstroke, net ankle extensor joint torque transfers energy from the crank to the limb to restore the potential energy of the limb. In both halves of the crank cycle, gravity forces augment the crank-limb energy transfer performed by the net ankle extensor joint torque.
Developmental sex differences in calbindin-D(28K) and calretinin immunoreactivity in the neonatal rat hypothalamus.

The proteins calbindin-D(28K) and calretinin buffer intracellular calcium and are speculated to be involved in the integration of neuronal signaling. Using Western blot analysis, we compared the levels of calbindin-D(28K) and calretinin in the developing male and female rat hypothalamus on postnatal days (PN) 0, PN2, PN4, PN6, PN8, and PN10. Analysis of variance (ANOVA) of mean calbindin levels indicated a significant effect of sex (p </=.001) and age (p </=. 0001) and a significant interaction (p </=.02). Post-hoc Neuman-Keuls analysis revealed that PN0 and PN2 males had significantly elevated calbindin levels over PN0 and PN2 females (p </=.05). ANOVA of mean calretinin levels from the same animals also indicated a significant effect of sex (p </=.002) and a significant interaction between sex and age (p </=.001). Post-hoc analysis indicated males had significantly elevated calretinin levels over PN0, PN4 (p </=.05) and PN6 (p </=.01) females. Immunocytochemical analyses indicated calbindin-immunopositive staining for cell bodies in the central subdivision of the medial preoptic nucleus, paraventricular nucleus, arcuate nucleus, and dorsomedial nucleus, and an area immediately surrounding the ventromedial nucleus (VMN). Calbindin immunoreactivity was absent from the ventrolateral VMN, but lightly stained cell bodies were observed in the dorsomedial VMN. The sex differences observed in calcium binding proteins parallel our previously observed sex differences in excitatory gamma-aminobutyric acid and glutamate early in development and may be related to mechanisms of sexual differentiation of the brain.
Effects of Women's Studies Courses on Gender-Related Attitudes of Women and Men:

Attitudes about feminism, gender equality, and gender differences were assessed for male and female students enrolled in three women's studies courses and four control courses at the beginning and end of an academic semester. Compared to control students, women's studies students agreed more with feminist and equality items, and disagreed more with gender difference items, at the beginning of the term. Nonetheless, belief in gender differences decreased among men, but not women, enrolled in women's studies courses. Additionally, women's studies courses produced increased feminist attitudes among women, but decreased feminist attitudes among the small sample of men in the study.
The interaction of nucleic acids with diamines

Abstract 1. 1. The interaction of nucleic acids with aliphatic diaminns (H 2 N(CH 2 ) n NH 2 ; 2≦ n ≦10) has been investigated, largely by means of helix → coil transition (absorbancy-temperature) profiles. In general the most pronounced effects effects produced by amines were those on T m , the transition midpoint, which is increased (rise ≡ ΔT m ) in the presence of diamines depending on the following parameters. (a) The ionic strength: for any one DNA and amine a decrease in ionic strength leads to an increase in ΔT m and in the strength of the interaction. (b) The concentration of amine: a typical saturation behavior is observed with ΔT m proportional to the amine concentration at low values of the latter and reaching a limiting value ΔT m (max.) at high concentration. Half saturation with diaminopentane is reached at 10 −2 M amine at high, and 10 −4 M amine at low ionic strength. (c) The chain length of amine: the effect is optimal when n = 5 and decreases on either side of the optimum. (d) The conformation of the nucleic acid: the effect is exhibited by double-stranded DNA but not by RNA or single-stranded DNA, nor by “acid” polyadenylic acid. (e) The base composition of the DNA: ΔT m is related to mole % (adenine plus thymine) or, more rigorously, proportional to T m of the DNA used. Teh proportioonality constants are −0.13 and −0.47° per degree in high- and low-ionic-strength media, respectively. 2. 2. These observations have been interpreted in terms of a model which postulates m independent binding sites for diamines on a DNA helix, where m ⪡ total number of nucleotide pairs. These sites involve bridging between the phhosphate residues of one strand and the adenine and/or thymine residues of the other, with the most stable interaction occuring for n = 5.
Twenty questions about student errors

Errors in science learning (errors in expression of organized, purposeful thought within the domain of science) provide a window through which glimpses of mental functioning can be obtained. Errors are valuable and normal occurrences in the process of learning science. A student can use his/her errors to develop a deeper understanding of a concept as long as the error can be recognized and appropriate, informative feedback can be obtained. A safe, non-threatening, and nonpunitive environment which encourages dialogue helps students to express their conceptions and to risk making errors. Pedagogical methods that systematically address common student errors produce significant gains in student learning. Just as the nature-nurture interaction is integral to the development of living things, so the individual-environment interaction is basic to thought processes. At a minimum, four systems interact: (1) the individual problem solver (who has a worldview, relatively stable cognitive characteristics, relatively malleable mental states and conditions, and aims or intentions), (2) task to be performed (including relative importance and nature of the task), (3) knowledge domain in which task is contained, and (4) the environment (including orienting conditions and the social and physical context). Several basic assumptions underlie research on errors and alternative conceptions. Among these are: Knowledge and thought involve active, constructive processes; there are many ways to acquire, organize, store, retrieve, and think about a given concept or event; and understanding is achieved by successive approximations. Application of these ideas will require a fundamental change in how science is taught.
Keeping Rong from Wrong: The Identification and Protection of Traditional Intellectual Property in Chuuk, Federated States of Micronesia

This discussion reviews the differences between traditional Micronesian principles regarding traditional knowledge, or ‘esoteric’ knowledge, and Western copyright laws, which have been used in the expropriation and legal alienation of traditional knowledge. We consider this conflict in relation to contemporary Native American intellectual property issues and tribal responses for the protection of such knowledge and to control research activities. This is compared with the recent international and Pacific Islands governments' concerns and actions regarding commodification and misappropriation of traditional knowledge, including the new Pacific Model Law. Finally, we review the nature of traditional knowledge in Chuuk State and its current status and recommend specific steps that the Federated States of Micronesia might take legislatively to protect traditional knowledge as part of its significant cultural heritage.
Atomoxetine for the treatment of executive dysfunction in Parkinson's disease: A pilot open-label study

Introduction Executive dysfunction (ED) is a prominent and often disabling feature of cognitive impairment in Parkinson’s disease (PD). Few studies have examined treatments. Given the role of noradrenergic pathology in ED, atomoxetine, a norepinephrine reuptake inhibitor indicated for attention deficit hyperactivity disorder (ADHD), may be a potential treatment for PD-related ED.
Dynamic effects of antibody-dependent enhancement on the fitness of viruses

Antibody-dependent enhancement (ADE), a phenomenon in which viral replication is increased rather than decreased by immune sera, has been observed in vitro for a large number of viruses of public health importance, including flaviviruses, coronaviruses, and retroviruses. The most striking in vivo example of ADE in humans is dengue hemorrhagic fever, a disease in which ADE is thought to increase the severity of clinical manifestations of dengue virus infection by increasing virus replication. We examine the epidemiological impact of ADE on the prevalence and persistence of viral serotypes. Using a dynamical system model of n cocirculating dengue serotypes, we find that ADE may provide a competitive advantage to those serotypes that undergo enhancement compared with those that do not, and that this advantage increases with increasing numbers of cocirculating serotypes. Paradoxically, there are limits to the selective advantage provided by increasing levels of ADE, because greater levels of enhancement induce large amplitude oscillations in incidence of all dengue virus infections, threatening the persistence of both the enhanced and nonenhanced serotypes. Although the models presented here are specifically designed for dengue, our results are applicable to any epidemiological system in which partial immunity increases pathogen replication rates. Our results suggest that enhancement is most advantageous in settings where multiple serotypes circulate and where a large host population is available to support pathogen persistence during the deep troughs of ADE-induced large amplitude oscillations of virus replication.
Serotonin-mediated inhibitory postsynaptic potential in guinea-pig prepositus hypoglossi and feedback inhibition by serotonin.

1. Intracellular recordings were made from neurones of the nucleus prepositus hypoglossi (PH) in slices of guinea-pig brain. Focal stimulation evoked an inhibitory postsynaptic potential (IPSP) that was typically 10-25 mV in amplitude and 1 s in duration. The IPSP reversal potential showed a Nernstian dependence on the external potassium concentration ([K+]o). 2. Spiperone blocked the IPSP with an IC50 of 40 nM, while ketanserin and (-)sulpiride had no effect. Cocaine (1 microM) prolonged the IPSP half-duration by 157%, and increased the amplitude by 28%. 3. 5-Hydroxytryptamine (5-HT, serotonin) hyperpolarized PH cells with an EC50 of 8.5 microM in control, and 135 nM in cocaine (10 microM). 8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) also hyperpolarized PH cells with an EC50 of 16 nM, although the maximal effect was only 81% of the maximum 5-HT hyperpolarization. Spiperone produced a parallel, right shift of the 5-HT concentration-response curve; Schild analysis gave a Kd of 10 nM. Application of 5-HT to neurones voltage-clamped near their resting potential (about -55 mV) caused an outward current and an increase in membrane conductance. 4. The amplitude of the IPSP was reversibly decreased by non-hyperpolarizing concentrations of 5-HT and by the 5-HT1 receptor agonists 1-(m-trifluoromethylphenyl)piperazine (TFMPP) and 1-(3-chlorophenyl)piperazine (mCPP). The IC50 values for the latter two compounds were 50 nM and 1.5 microM, respectively; the maximal effect was a 90% inhibition. Neither compound affected the membrane potential nor changed the hyperpolarization induced by 5-HT. Quipizine competitively antagonized TFMPP with an estimated Kd of 165 nM. 5. When trains of stimuli were applied, an inhibition of the IPSP was observed following the first stimulus. At a frequency of 1 Hz, the inhibition was approximately 75%. This frequency-dependent ‘run-down’ of the IPSP was markedly attenuated by pre-treatment with TFMPP (1 microM). 6. It is concluded that the IPSP in PH cells is caused by 5-HT acting on 5-HT1A receptors to activate a potassium conductance. The release of 5-HT can be inhibited by activation of a presynaptic 5-HT1D receptor. This presynaptic receptor appears to be at least partly responsible for the run-down phenomenon, and may be involved in the physiological regulation of 5-HT synaptic transmission.
Influence diagnostics for the Weibull model fit to censored data

Methods for detecting influential observations for the Weibull model fit to censored data are discussed. These methods include: one-step deletion diagnostics, influence functions and curvature diagnostics. Results indicate that the curvature diagnostics may be helpful in detecting masking.
Qualitative plus/versus quantitative: The last word

Neither methodological correctness nor paradigm purity offers an appropriate framework for evaluation practice.
Evaluation of five landscape-level metrics for measuring the effects of urbanization on landscape structure: the case of Tucson, Arizona, USA

Landscape-level metrics can be used to measure changes in landscape structure over time. Four landscape-level metrics and rank-size distributions were used to describe changes in landscape structure caused by urbanization in a portion of the Tucson, Arizona metropolitan area between 1984 and 1998. This analysis describes what each metric conveys regarding how urbanization affects landscape structure. It also compares the efficacy of rank-size distributions with the other metrics. Results indicate all five metrics provided information about a specific aspect of landscape structure including patch size, shape, or dispersion. Results indicate that rank-size distributions and their scaling exponents are useful because they provide information not available from the other metrics. Rank-size distributions describe the patch-size scaling properties of specific land-cover types, the relative effect of large and small patches on the distribution of patch sizes, the magnitude of change in patch size, where patch sizes differ from what is expected by the regression model, and the range of patch sizes displaying fractal patterns.
Comparison of the fidelity of radiographs of mandibular condyles made by different techniques

Abstract The radiograph is an important aid in the diagnosis of temporomandibular joint problems. A marked difference of opinion exists in the interpretation of radiographs produced by various techniques. To establish some common basis for agreement, a study of the morphology of the condyle of the temporomandibular joint was undertaken. Temporomandibular joints of cadavers were radiographed and dissected. The dissections revealed a startling variation in the form of condyles and many instances of pathologic aberrations. Radiographs of the temporomandibular joints were made by three commonly used techniques to correlate the morphology of condyles with their radiographic appearance. All three techniques (Atco, Updegrave and Lindblom) failed to provide a meaningful depiction of the three-dimensional appearance of condyles with irregular forms. Tomography was used to obtain radiographic information of greater diagnostic value. The Polytome H machine uses a hypocycloidal (twisting, pretzel-like) movement to provide radiographs of predetermined sections of structures. All structures other than the thin section desired are blurred out by the hypocycloidal movement of the machine. Tomographs were made of patients with temporomandibular joint problems in conjunction with conventional radiographs for diagnostic study and comparative evaluation. The tomographs provided evidence of condyle and glenoid fossa irregularities that were undetectable by the usual radiographs. When tomographs are made of both sides and in the open and closed positions, valuable clinical information about intercondylar symmetry and the comparative symmetry of condylar movement is provided. Tomography was used on cadavers to determine the fidelity of (1) conventional radiographs and (2) tomographic radiographs in relation to the gross structures they are expected to depict. Comparisons were made of radiographs of the in situ condyles that were obtained by the three one-plane techniques. No significant differences were observed in the radiographs obtained. Comparisons were made of in situ one-plane radiographs with the ideally angulated radiographs of the enucleated condyle. A fair degree of fidelity of the in situ radiographs was observed. However, both radiographs depicted only maximum contours of the condyle and failed to reveal irregularities in contour when asymmetry or pathologic aberrations are present. Comparisons were made of in situ one-plane radiographs with ideally angulated radiographs of the serial cuts of the enucleated condyle. Some degree of fidelity of the in situ radiographs was observed when a symmetrical condyle was sectioned. Lack of fidelity was noted when condylar irregularity was present. Comparisons were made of individual radiographs of a tomographic series with the corresponding ideally angulated radiographs of the condyle section depicted. A fair degree of fidelity of the radiographic image of the tomographic radiograph was observed. However, tomographic radiographs exhibit some magnification and are not as sharp and clear as conventional radiographs.
Uncovering Common Stressful Factors and Coping Strategies Among Childcare Providers

The purpose of this study was to identify the common stress factors among childcare providers and the coping strategies they use to relieve work stress feelings throughout the day. Qualitative data was gathered from a random sample of ten local childcare providers across different races, years of experience, and licensed childcare centers who participated in in-depth focus group interviews. The stressful work factors described by childcare providers included work conditions, work events, client factors and external factors. Childcare providers also describe several coping strategies such as walking, prayer and meditation or planning for stressful moments. Results from this study provide practical approaches for relieving work stress among childcare providers.
Detection of human immunodeficiency virus (HIV) genome from the lymphocytes of homosexual men

Human immunodeficiency virus (HIV) is the primary etiological agent of acquired immunodeficiency syndrome (AIDS). This virus can be transmitted by blood or blood products. Homosexual males (HM) are regarded as one of the high-risk groups for AIDS. Lymphocytes obtained from HM were used for cocultivation with fresh HIV antibody negative lymphocytes. The presence of virus particles was monitored by reverse transcriptase (RT) activity. Three out of eleven donors were found to have reverse transcriptase activity. All three donors were also found to be HIV antibody positive. HIV DNA from infected cells was detected by dot blot hybridization. The number of genome per cell is low. The correlation between RT activity and the cytolytic effect of HIV will be discussed.