cssi/SciSciGPT-SciSciNet huggingface dataset:
Neonatal perforated appendicitis associated with duodenal obstruction

The case of a premature infant with a simultaneous occurrence of appendiceal perforation and incomplete fixation of the colon producing early obstruction of the duodenum is reported. The clinical examination and laboratory and radiological investigations were all negative for the diagnosis of appendicitis, which was found incidentally at laparotomy for duodenal obstruction.
SU-E-T-156: Robust Algorithms for Correction of Predicted Electronic Portal Imager Response

Purpose: Predicted electronic portal imaging device(EPID) response, as calculated by a commercial treatment planning system (TPS), is up to 15% lower than measured EPID response for off‐axis IMRT fields. Two original algorithms are presented to correct for EPID prediction errors. The EPID prediction algorithm and a recent image‐to‐dose conversion algorithm are each tested for ability to identify TPS dose calculation errors. Methods: By comparing test images to respective predictions, correction factors were calculated to modify the EPID diagonal calibration profile (applied via radial symmetry). Secondly, image/prediction comparisons were used to compute a 2D correction matrix for EPID predictions, to account for radially‐asymmetric errors. Over 50 IMRT fields of varying complexity were tested with each correction technique, and with a diode array. Absolute dose and beam‐profile errors were separately induced into the TPS and a number of IMRT plans were recalculated and measured with three systems ‐ an EPID prediction system, an EPIDimage‐to‐dose conversion system, and a diode array ‐ for comparison to verification plans. Results: With the profile correction, TPS predictions agree much better with EPID measurements, yielding improvement in gamma pass rates (3%,3mm) of over 30% on average for off‐axis IMRT fields. Since off‐axis prediction errors are not radially‐symmetric, the matrix correction further improves pass rates by 5% on average (up to 30%) for fields where the profile correction is limited. The EPID prediction system was unable to catch either induced TPS error, while both the image‐to‐dose conversion system and the diode array indicated both errors. Conclusions: Profile correction is effective and efficient though approximate, due to radial symmetry. The matrix correction is comprehensive but requires computational manipulation of DICOM images. Users must be aware that EPID prediction systems may be unable to catch delivered IMRT inaccuracies due to calculation errors downstream from the actual fluence calculation.
Does perilymph modify cupula deflection

The concept of perilymphatic actuation of the cupula proposed by Anliker & VanBuskirk (Acta Otolaryng 72, 93–100, 1971) has been reviewed and found that their model is based on a quite erroneous concept of the anatomy of the temporal bone. Careful study of serial slides of the temporal bone shows that the cupular deflection is caused primarily by flow of endolymph, and therefore, the mathematical model based upon a faulty view of the anatomy of the system cannot be accepted.
A Boussinesq model for pressure and flow velocity waves in arterial segments

We derive a nonlinear model for the pressure and flow velocity wave propagation in an arterial segment. We then study the transmission and reflection of pulses at bifurcation. We observe a linear dependence of the transmitted speeds to the incoming speeds, and similarly for the reflected speeds. We propose a method for validating the numerical results obtained from this model against real data.
Role of response availability in forgetting: A re-appraisal

Saltz & Youssef’s (1964) hypothesis that the loss of response differentiation is a critical factor in forgetting was confirmed, contrary to their own data. Response retraining of CVC’s and adjectives before recall facilitated retention as compared to pairs with non-retrained items. Stimulus retraining impeded recall. The results are attributed to neither warm up nor rehearsal but rather to increased response availability. Extension of Underwood & Schulz’s (1960) two phase acquisition process to forgetting appears warranted.
Time bounds for selection

The number of comparisons required to select the i-th smallest of n numbers is shown to be at most a linear function of n by analysis of a new selection algorithm-PICK. Specifically, no more than 5.4305 n comparisons are ever required. This bound is improved for extreme values of i, and a new lower bound on the requisite number of comparisons is also proved.
Upstream Stimulatory Factor (USF) Is Recruited into a Steroid Hormone-triggered Regulatory Circuit by the Estrogen-inducible Transcription Factor δEF1

In the past decade, investigation into steroid hormone signaling has focused on the mechanisms of steroid hormone receptors as they act as signaling molecules and transcription factors in cells. However, the majority of hormone-responsive genes are not directly regulated by hormone receptors. These genes are termed secondary response genes. To explore the molecular mechanisms by which the steroid hormone estrogen regulates secondary response genes, theovalbumin(Ov) gene was analyzed. Three protein-protein complexes (Chirp-I, -II, -III), which do not contain the estrogen receptor, are induced by estrogen to bind to the 5′-flanking region of the Ov gene. The Chirp-III DNA binding site, which is required for estrogen induction, binds a complex of proteins that contains the estrogen-inducible transcription factor δEF1. Experiments undertaken to identify proteins complexed with δEF1 led to the elucidation of a novel mechanism of action of upstream stimulatory factor-1 (USF-1), which involves its tethering to the Ov gene 5′-flanking region by δEF1. Gel mobility shift assays and co-immunoprecipitation experiments identify USF-1 as a component of Chirp-III. However, USF-1 is not able to bind to the Chirp-III site independently. In addition, USF-1 overexpression is able to induce Ov gene promoter activity in transfection experiments. USF-1 can also potentiate the induction of theOv gene by the transcription factor δEF1. Moreover, mutating the δEF1 binding sites in the 5′-flanking region of theOv gene abrogates induction of the gene by USF-1. These data begin to establish a molecular mechanism by which hormone-inducible transcription factors and ubiquitous transcription factors cooperate to regulate estrogen-induced secondary response gene expression.
Transport in Flat Heat Pipes at High Heat Fluxes From Multiple Discrete Sources

A three-dimensional model has been developed to analyze the transient and steady-state performance of flat heat pipes subjected to heating with multiple discrete heat sources. Three-dimensional flow and energy equations are solved in the vapor and liquid regions, along with conduction in the wall. Saturated flow models are used for heat transfer and fluid flow through the wick. In the wick region, the analysis uses an equilibrium model for heat transfer and a Brinkman-Forchheimer extended Darcy model for fluid flow. Averaged properties weighted with the porosity are used for the wick analysis. The state equation is used in the vapor core to relate density change to the operating pressure. The density change due to pressurization of the vapor core is accounted for in the continuity equation. Vapor flow, temperature and hydrodynamic pressure fields are computed at each time step from coupled continuity/momentum and energy equations in the wick and vapor regions. The mass flow rate at the interface is obtained from the application of kinetic theory Predictions are made for the magnitude of heat flux at which dryout would occur in a flat heat pipe. The input heat flux and the spacing between the discrete heat sources are studied as parameters. The location in the heat pipe at which dryout is initiated is found to be different from that of the maximum temperature. The location where the maximum capillary pressure head is realized also changes during the transient. Axial conduction through the wall and wick are seen to play a significant role in determining the axial temperature variation.
Organolanthanide-Catalyzed Imine Hydrogenation. Scope, Selectivity, Mechanistic Observations, and Unusual Byproducts

In this paper we report the Cp‘2Ln/Me2SiCp‘‘2Ln-catalyzed (Cp‘ = η5-Me5C5; Cp‘‘ = η5-Me4C5) hydrogenation of acyclic imines to yield the corresponding amines. At 190 psi of H2, the observed turnover frequencies (h-1) (100:1 substrate:catalyst ratio, Cp‘2Ln, temperature (°C)) are (1) (N-benzylidene(methyl)amine, Ln = La, 50) 0.03; (Ln = Sm, 90) 1.0; (Ln = Sm + PhSiH3, 90) 2.2; (Ln = Lu, 90) 0.60; (2) (N-benzylideneaniline, Ln = Sm, 90) 0.10; (3) (N-benzylidene(trimethylsilyl)amine, Ln = Sm, 90) 0.40; (4) (N-(α-methylbenzylidene)(methyl)amine, Ln = Sm, 90) 0.20; (5) (N-(α-methylbenzylidene)(benzyl)amine, Ln = Sm, 90) 0.70. The stoichiometric reaction of N-benzylidene(methyl)amine with Cp‘2SmCH(SiMe3)2 or (Cp‘2SmH)2 yields an orthometalated Cp‘2Sm−substrate complex which undergoes either hydrogenolysis/hydrogenation or competing CN insertion of a second substrate molecule to yield a Cp‘2Sm-imine−amido complex with a seven-membered chelate ring. The stoichiometric reaction of 2-methyl-1-pyrroline with Cp‘2SmC...
Development of new microsatellite primers for green and white sturgeon

Sixty-eight primer sets for microsatellite loci were developed from microsatellite motif enriched genomic libraries of pooled DNA from the polyploid green and white sturgeon (Acipenser medirostris and A. transmontanus). Four individuals from each species were screened for polymorphism at these loci. Forty-eight loci amplified in both species, and some exhibited species-specific amplification for white or green sturgeon (8 and 12 loci, respectively). The number of alleles per locus ranged from one to 12. At least 68% of the green and 65% of the white sturgeon loci we developed are polysomic.
Evidence that the C-terminus of the D1 polypeptide of photosystem II is ligated to the manganese ion that undergoes oxidation during the S1 to S2 transition: an isotope-edited FTIR study.

Isotope-edited FTIR difference spectroscopy was employed to determine if the C-terminal α-COO- group of the D1 polypeptide ligates the (Mn)4 cluster in photosystem II (PSII) and, if so, if it ligates the Mn ion that undergoes an oxidation during the S1 → S2 transition. Wild-type and mutant cells of the cyanobacterium Synechocystis sp. PCC 6803 were propagated photoautotrophically in the presence of l-[1-13C]alanine or unlabeled (12C) l-alanine. In wild-type cells, both the C-terminal α-COO- group of the D1 polypeptide at D1-Ala344 and all alanine-derived peptide carbonyl groups will be labeled. In D1-A344G and D1-A344S mutant cells, the C-terminal α-COO- group of the D1 polypeptide will not be labeled because this group is no longer provided by alanine. The resultant S2-minus-S1 FTIR difference spectra of purified wild-type and mutant PSII particles showed that one symmetric carboxylate stretching mode that is altered during the S1 → S2 transition is sensitive to l-[1-13C]alanine-labeling in wild-type PSI...
Eye movements and the identification of spatially ambiguous words during Chinese sentence reading

Readers of Chinese must generally determine word units in the absence of visually distinct inter-word spaces. In the present study, we examined how a sequence of Chinese characters is parsed into words under these conditions. Eye movements were monitored while participants read sentences with a critical four-character (C1234) sequence. Three partially overlapping character groupings formed legal words in the ambiguous condition (C12, C23, and C34), two of which corresponded to context-consistent words (C12 and C34). Two nonoverlapping groupings corresponded to legal words in the control conditions (C12 and C34). In two experiments, readers spent more time viewing the critical character sequence and its two center characters (C23) in the ambiguous condition. These results argue against the strictly serial assignment of characters to words during the reading of Chinese text.
An Approach to the Newly Diagnosed Colorectal Cancer Patient with Synchronous Stage 4 Disease

Although algorithmic diagrams are popular as aids to treatment plans in medicine, stage 4 colorectal cancer is probably too complex for diagrams. There are too many variables. The surgeon should know that although most patients with colorectal cancer with stage 4 disease will ultimately die from their cancer, there is a significant number of patients who can be palliated in a meaningful way, and a very small number who may actually be cured. The surgeon along with his colleagues needs to carefully select patients who can be palliated and those who may be cured from the larger group to ensure optimal care. Some patients should never see the inside of an operating room except perhaps for the implantation of an intravenous chemotherapy port.
Impact of prolonged sitting on lower and upper limb micro‐ and macrovascular dilator function

New Findings What is the central question of this study? The prevalence of sedentary behaviour in the workplace and increased daily sitting time have been associated with the development of cardiovascular disease; however, studies investigating the impact of sitting on vascular function remain limited. What is the main finding and its importance? We demonstrate that there is a marked vulnerability of the vasculature in the lower and upper limbs to prolonged sitting and highlight the importance of physical activity in restoring vascular function in a limb-specific manner. Sedentary behaviour in the workplace and increased daily sitting time are on the rise; however, studies investigating the impact of sitting on vascular function remain limited. Herein, we hypothesized that 6 h of uninterrupted sitting would impair limb micro- and macrovascular dilator function and that this impairment could be improved with a bout of walking. Resting blood flow, reactive hyperaemia to 5 min cuff occlusion (microvascular reactivity) and associated flow-mediated dilatation (FMD; macrovascular reactivity) were assessed in popliteal and brachial arteries of young men at baseline (Pre Sit) and after 6 h of uninterrupted sitting (Post Sit). Measures were then repeated after a 10 min walk (∼1000 steps). Sitting resulted in a marked reduction of resting popliteal artery mean blood flow and mean shear rate (6 h mean shear rate, −52 ± 8 s−1 versus Pre Sit, P < 0.05). Interestingly, reductions were also found in the brachial artery (6 h mean shear rate, −169 ± 41 s−1 versus Pre Sit, P < 0.05). Likewise, after 6 h of sitting, cuff-induced reactive hyperaemia was reduced in both the lower leg (−43 ± 7% versus Pre Sit, P < 0.05) and forearm (−31 ± 11% versus Pre Sit, P < 0.05). In contrast, popliteal but not brachial artery FMD was blunted with sitting. Notably, lower leg reactive hyperaemia and FMD were restored after walking. Collectively, these data suggest that prolonged sitting markedly reduces lower leg micro- and macrovascular dilator function, but these impairments can be fully normalized with a short bout of walking. In contrast, upper arm microvascular reactivity is selectively impaired with prolonged sitting, and walking does not influence this effect.
Characterization of an arachidonic acid-deficient (Fads1 knockout) mouse model.

Arachidonic acid (20:4Δ5,8,11,14, AA)-derived eicosanoids regulate inflammation and promote cancer development. Previous studies have targeted prostaglandin enzymes in an attempt to modulate AA metabolism. However, due to safety concerns surrounding the use of pharmaceutical agents designed to target Ptgs2 (cyclooxygenase 2) and its downstream targets, it is important to identify new targets upstream of Ptgs2. Therefore, we determined the utility of antagonizing tissue AA levels as a novel approach to suppressing AA-derived eicosanoids. Systemic disruption of the Fads1 (Δ5 desaturase) gene reciprocally altered the levels of dihomo-γ-linolenic acid (20:3Δ8,11,14, DGLA) and AA in mouse tissues, resulting in a profound increase in 1-series-derived and a concurrent decrease in 2-series-derived prostaglandins. The lack of AA-derived eicosanoids, e.g., PGE2, was associated with perturbed intestinal crypt proliferation, immune cell homeostasis, and a heightened sensitivity to acute inflammatory challenge. In addition, null mice failed to thrive, dying off by 12 weeks of age. Dietary supplementation with AA extended the longevity of null mice to levels comparable to wild-type mice. We propose that this new mouse model will expand our understanding of how AA and its metabolites mediate inflammation and promote malignant transformation, with the eventual goal of identifying new drug targets upstream of Ptgs2.
Small Particle Transport Across Turbulent Nonisothermal Boundary Layers

The interaction between turbulent diffusion, Brownian diffusion, and particle thermophoresis in the limit of vanishing particle inertial effects is quantitatively modeled for applications in gas turbines. The model is initiated with consideration of the particle phase mass conservation equation for a two-dimensional boundary layer, including the thermophoretic flux term directed toward the cold wall. A formalism of a turbulent flow near a flat plate in a heat transfer problem is adopted, and variable property effects are neglected. Attention is given to the limit of very large Schmidt numbers and the particle concentration depletion outside of the Brownian sublayer. It is concluded that, in the parameter range of interest, thermophoresis augments the high Schmidt number mass-transfer coefficient by a factor equal to the product of the outer sink and the thermophoretic suction.
An interstitial 15q11‐q14 deletion: Expanded Prader‐Willi syndrome phenotype

We present an infant girl with a de novo interstitial deletion of the chromosome 15q11-q14 region, larger than the typical deletion seen in Prader-Willi syndrome (PWS). She presented with features seen in PWS including hypotonia, a poor suck, feeding problems, and mild micrognathia. She also presented with features not typically seen in PWS such as preauricular ear tags, a high-arched palate, edematous feet, coarctation of the aorta, a PDA, and a bicuspid aortic valve. G-banded chromosome analysis showed a large de novo deletion of the proximal long arm of chromosome 15 confirmed using FISH probes (D15511 and GABRB3). Methylation testing was abnormal and consistent with the diagnosis of PWS. Because of the large appearing deletion by karyotype analysis, an array comparative genomic hybridization (aCGH) was performed. A 12.3 Mb deletion was found which involved the 15q11-q14 region containing approximately 60 protein coding genes. This rare deletion was approximately twice the size of the typical deletion seen in PWS and involved the proximal breakpoint BP1 and the distal breakpoint was located in the 15q14 band between previously recognized breakpoints BP5 and BP6. The deletion extended slightly distal to the AVEN gene including the neighboring CHRM5 gene. There is no evidence that the genes in the 15q14 band are imprinted; therefore, their potential contribution in this patient's expanded PWS phenotype must be a consequence of dosage sensitivity of the genes or due to altered expression of intact neighboring genes from a position effect.
Clinical pharmacokinetics 1990.

These developments in analytical techniques, evaluation of disease state effects on pharmacokinetics and pharmacodynamics, enhancements in data analysis and technological advances which allow us better ways of measuring pharmacodynamics, would potentially be wasted if there were no methodologies to apply these findings to patient care. This approach appears also to provide accurate measures of population pharmacokinetic central tendencies and variations
Parent Involvement: Influencing Factors and Implications

Abstract The involvement of Mexican American parents in their children's education was explored in a year-long case study of an elementary school in Texas. Interviews, document analysis, and observations of parent activities revealed that parent involvement was influenced by several factors, including language, parent cliques, parents' education, attitudes of the school staff, cultural influences, and family issues. Although the school staff addressed some of the issues, in general, teachers did not recognize the influence that these concerns had on parent involvement. The findings have implications for teachers that affect both the level and areas of Mexican American parent involvement. An understanding of these factors will provide ways to increase and improve parent involvement.
Relation between acute changes in pH and PCO2 and inotropic responses to acetyl strophanthidin.

Abstract The effects of acutely induced hypercapnic or lactic acidemia on the inotropic responses to acetyl strophanthidin were studied in adult cats. Beta adrenergic blockade was produced with propranolol to eliminate sympathetic influences on the heart. In control animals significant increases in stroke volume, mean ejection rate and rate of rise of left ventricular pressure (dPdt) were shown after infusion of acetyl strophanthidin, 15 μg/kg. Similar increases were demonstrated in cats with lactic acidemia (pH 7.0) or hypercapnic acidemia (PCO 2 60 mm Hg). The responses of cats with low pH or high PCO 2 values did not differ significantly within the 2 groups or by comparison with control responses. These results demonstrate (1) that digitalis is effective in producing significant inotropic responses even under these altered metabolic conditions, and (2) that propranolol does not inhibit these responses.
Predictive models of large neutrino mixing angles

Several experimental results could be interpreted as evidence that certain neutrino mixing angles are large, of order unity. However, in the context of grand unified models the neutrino angles come out characteristically to be small, like the KM angles. It is shown how to construct simple grand-unified models in which neutrino angles are not only large but completely predicted with some precision. Six models are presented for illustration.
Predicting Child Physical Abuse Recurrence: Comparison of a Neural Network to Logistic Regression

ABSTRACT The present study explored the potential of an artificial neural network to improve prediction of recurrences of child physical abuse. Conducted on electronic data file compiled by the U.S. Air Force's central registry of child abuse reports, selected variables pertaining to all child physical abuse reports received from 1990–2000 (N = 5,612) were examined. Thirteen predictor variables and five interaction terms were identified for analysis. The neural network ultimately did not outperform an alternative method, binary logistic regression.
Oestrogen action in the endometrium and oviduct of rhesus monkeys during RU486 treatment

Two experiments were conducted to determine how RU486 affected oestradiol action in the non-human primate female reproductive tract. In the first experiment, spayed rhesus monkeys were first treated with a sequential regimen of oestradiol and progesterone to cause regression and deciliation in the oviduct and progestational development in the endometrium. The ability of oestradiol to stimulate oviductal differentiation and endometrial regeneration in the presence of RU486, progesterone, and progesterone plus RU486 was then tested. RU486 was found to block the ability of oestradiol to increase endometrial growth but did not prevent oestradiol-dependent oviductal differentiation. Also, in the endometrium but not the oviduct, RU486 action differed from simple progesterone withdrawal by causing stromal compaction and glandular apoptosis. In the second experiment, spayed monkeys were first treated with oestradiol for 2 weeks to produce a fully differentiated, ciliated-secretory oviduct and an hypertrophied, proliferative endometrium. The ability of oestradiol to maintain these conditions in oviduct and endometrium during treatment with RU486, progesterone, and progesterone plus RU486 was then tested. It was found that RU486 suppressed the ability of oestradiol to maintain the endometrium in a hypertrophied state but not its ability to maintain the oviduct in a fully ciliated-secretory state. As before, RU486 induced extensive glandular apoptosis and stromal compaction in the endometrium, but not the oviduct. These endometrial effects appeared to be due to a combination of a decrease in proliferation, an increase in epithelial cell death by apoptosis, an increase in stromal compaction and a concomitant decrease in interstitial fluid content, all of which led to a decrease in endometrial wet weight and thickness. These effects of RU486 on oestradiol action were similar in the presence and absence of progesterone and were therefore separate and distinct from the classical antiprogestin effects of RU486. Because RU486 did not inhibit the ability of oestradiol to either stimulate or maintain oviductal differentiation or wet weight, these results suggest that the endometrium is much more sensitive to the anti-proliferative effects of RU486 than the oviducts.
Dealing with data: a milestone in statistical genetics

The world of genetics has seen an explosion of data with gene sequences and whole genomes accumulating in databases at an astounding rate. Fortunately, it has also seen an explosion of interest in developing the statistical tools necessary to analyze and understand these data. Unfortunately, the tools have been widely scattered, difficult to find, and almost impossible to compare with one another. The editors of this book have done us a great service by inviting analytical reviews of nearly all relevant topics from leaders in the field and making them available in a single, admittedly very large, volume. The tools available can now be easily identified, their possibilities and limitations assessed.
Penile erection in the rat: Stimulation of the hypogastric nerve elicits increases in penile pressure after chronic interruption of the sacral parasympathetic outflow

Penile erection, a vascular event mediated by the autonomic nervous system, is often adversely affected by injury to the spinal cord. To further characterize the laboratory rat as an animal model of penile erection and to investigate erectile responses following neural injury, the present study has examined pressor penile responses in intact rats and in animals deprived of sacral parasympathetic outflow. Increases in penile pressure result from graded stimulation of postganglionic parasympathetic fibers. The vasodilator response is insensitive to blockade with atropine, a cholinergic antagonist. Penile tumescence also results from stimulation of the pelvic nerve, but not the hypogastric nerve. However, beginning 3 days after unilateral interruption of the pelvic nerve, stimulation of the ipsilateral hypogastric nerve results in an increase in penile pressure. This novel response, which is blocked by a ganglionic antagonist, is maximally developed at 1 week post-lesion, is stable for at least 3 months and remains confined to the side of the lesion. These results suggest that the rat, although relatively small, can be used to obtain quantitative data on penile erection. Moreover, the model may lend itself to an analysis of the mechanisms of altered control of visceral tissues following injury to the nervous system.
Sequence of effects of acifluorfen on physiological and ultrastructural parameters in cucumber cotyledon discs

Abstract The time course for development of herbicidal effects of acifluorfen on the ultrastructure and physiology of cotyledon discs from 6- to 8-day-old, light-grown cucumber ( Cucumis sativus L.) seedlings was examined. After 20 hr of incubation in darkness in 30 μ M acifluorfen no herbicidal damage was detected, but within 1.5 hr after subsequent exposure to 420 μEin m −2 sec −1 PAR, chloroplast envelope, tonoplast, and plasma membrane disruption was observed. Choloroplast thylakoid disruption occurred after envelope disruption. CO 2 -Dependent O 2 evolution was reduced ca. 30% within 1 hr of the onset of light exposure, whereas dark O 2 uptake was not affected during a 5-hr time course. Reduction of in vivo variable chlorophyll fluorescence and cytochrome f oxidation/reduction was observable within 1 hr and was reduced by ca. 90% within 5 hr. Neither carotenoid nor chlorophyll content declined significantly during 5 hr of light, whereas acifluorfen caused increases in ethane, ethylene, and malondialdehyde within 2 hr. Increased leakage of electrolytes was detectable within 1 hr. These data indicate that loss of membrane integrity, perhaps beginning with the plastid envelope, precedes most of the other symptoms of acifluorfen-caused cellular damage.
Thermochemical structures beneath Africa and the Pacific Ocean

Large low-velocity seismic anomalies have been detected in the Earth's lower mantle beneath Africa and the Pacific Ocean that are not easily explained by temperature variations alone. The African anomaly has been interpreted to be a northwest-southeast-trending structure with a sharp-edged linear, ridge-like morphology. The Pacific anomaly, on the other hand, appears to be more rounded in shape. Mantle models with heterogeneous composition have related these structures to dense thermochemical piles or superplumes. It has not been shown, however, that such models can lead to thermochemical structures that satisfy the geometrical constraints, as inferred from seismological observations. Here we present numerical models of thermochemical convection in a three-dimensional spherical geometry using plate velocities inferred for the past 119 million years. We show that Earth's subduction history can lead to thermochemical structures similar in shape to the observed large, lower-mantle velocity anomalies. We find that subduction history tends to focus dense material into a ridge-like pile beneath Africa and a relatively more-rounded pile under the Pacific Ocean, consistent with seismic observations.
'Basket' Cases: Tax Incentives and International Joint Venture Participation by American Multinational Firms

Abstract This paper examines the impact of the U.S. Tax Reform Act of 1986 (TRA) on international joint ventures by American firms. The TRA mandates the use of separate “baskets” in calculating foreign tax credits on dividends received from each foreign corporation owned 50% or less by Americans – which greatly reduces the attractiveness of joint ventures, especially those in low-tax foreign countries. Since the effect of the TRA on joint ventures varies with foreign tax rates, the country-level pattern of subsequent joint venture activity illustrates the sensitivity of organizational form to tax considerations. The evidence indicates that American participation in international joint ventures fell sharply after 1986, particularly in low-tax countries. Moreover, joint ventures in low-tax countries use more debt and pay greater royalties to their American parents after 1986, reflecting their incentives to economize on dividend payments.
Interaction of the discriminative stimulus effects of phencyclidine with those of (+)-N-allynormetazocine, pentobarbital and d-amphetamine

Pigeons trained to discriminate 1.0 mg/kg phencyclidine from saline were used to study the interaction between the stimulus effects of phencyclidine and those of (+)-N-allylnormetazocine [(+) NANM], pentobarbital and d-amphetamine using a cumulative-dosing procedure. Both (+) NANM and pentobarbital enhanced the discriminative stimulus effects of phencyclidine. The enhancement of the phencyclidine stimulus by pentobarbital was predicted by adding the effects of the individual drugs, but the enhancement of the phencyclidine stimulus by (+) NANM was sometimes more than would have been expected from adding the effects of the individual drugs. d-Amphetamine did not enhance the discriminative stimulus effects of phencyclidine, but neither did it interfere with these effects. Combinations of (+) NANM or pentobarbital with phencyclidine also enhanced the rate-decreasing effects of phencyclidine, but to a lesser extent than they enhanced the discriminative stimulus effects of phencyclidine. d-Amphetamine only slightly enhanced the rate-decreasing effects of phencyclidine.
A spectrophotometric assay for the degradation of the siderophore deferrioxamine B.

Abstract A spectrophotometric assay using ferric perchlorate in a perchloric acid solution has been developed to monitor the degration of the trihydroxamate siderophore deferrioxamine B to monohydroxamates. Using the ferric perchlorate solution and employing various concentrations of acetohydroxamic acid (as the model monohydroxamic acid) while maintaining a constant amount of deferrioxamine B resulted in the shifting of the absorption maximum from that of ferrioxamine B to longer wavelengths and toward that of a pure ferri-acetomonohydroxamic acid solution. A similar result was noted when a cell-free extract, from a bacterium capable of usig deferrioxamine B as its sole carbon source, was given the siderophore in a phosphate buffer and aliquots of the enzyme-deferionxamine B solution were removed for analysis. The assay may thus be used to monitor the formation of the monohydroxamic acid degradation products of the siderophore by the enzyme(s) in the cell-free extract.
Racial differences in sensitivity to the negative chronotropic effects of propranolol in healthy men.

Objective Dose-response studies in patients with hypertension have shown that black subjects are less responsive to β-blocker therapy than white subjects, whereas studies in healthy volunteers suggest marginal or no racial differences in response. No concentration-response studies have been conducted in black subjects and white subjects. The purpose of this study was to characterize β-blocker pharmacodynamics in healthy black and white men. Methods Thirteen black and 13 white healthy men took 80 mg oral propranolo three times daily, for a total of 16 doses. Heart rate response to treadmill exercise was measured at various times over 24 hours. Serum propranolol samples were collected during the same 24-hour time period and were measured by chiral HPLC. The sigmoid maximal effect (Emax), Emax, and linear models were fitted to percentage reductions in exercise heart rate and S-propranolol concentrations. Results Black subjects had significantly lower values for serum concentration producing one-half the maximal effect (EC50) and unbound EC50 than white subjects (EC50: 10.2 ng/ml (4.4 to 28.0 ng/ml) versus 24.4 ng/ml (14.3 to 64.1 ng/ml), blacks versus whites; unbound EC50: 1.29 ng/ml (0.686 to 4.91 ng/ml) versus 2.77 ng/ml (1.70 to 8.11 ng/ml), blacks versus whites). There was no statistical difference in Emax (33.3% [22.2% to 39.7%] versus 38.3% [30.7% to 45.1%], blacks versus whites). Conclusions Healthy black men were more sensitive to β-blockade than healthy white men. The results of this study in healthy volunteers suggest that the racial differences in response observed in patients with hypertension are related to hypertensive pathophysiology rather than normal physiology. Clinical Pharmacology & Therapeutics (1995) 57, 678–683; doi:
Vibration-Analysis Studies Using Changes of Laser Speckle*†

A high-acoustical Q object that vibrates in a resonant mode and has a moderately rough surface illuminated by dispersed laser light shows patterns analogous to Chladni (strewn sand) patterns. These patterns appear as regions in which the laser speckle is similar to that of a rough surface at rest, whereas the rest of the surface has fewer and smaller dark regions between bright speckles. The explanation for this is that regions that undergo the greatest variation of tilt (e.g., usually around nodes) blur the bright speckles. The effect is readily observed visually and may be photographed with some difficulty. Some examples with flat plates, along with the corresponding Chladni sand patterns at the same resonant frequencies, are given. The laser-speckle patterns usually occur at antinodes and are thus complementary to most Chladni patterns. Laser-speckle patterns can be used to provide a real-time noncontact method for vibration analysis, to study flat surfaces in a nonhorizontal position, to eliminate the shift of resonant modes caused by additional weight, and to study curved surfaces, as is shown with a cylindrical can.
Crystal structure of the receptor binding domain of the botulinum C–D mosaic neurotoxin reveals potential roles of lysines 1118 and 1136 in membrane interactions

The botulinum neurotoxins (BoNTs) produced by different strains of the bacterium Clostridium botulinum are responsible for the disease botulism and include a group of immunologically distinct serotypes (A, B, E, and F) that are considered to be the most lethal natural proteins known for humans. Two BoNT serotypes, C and D, while rarely associated with human infection, are responsible for deadly botulism outbreaks afflicting animals. Also associated with animal infections is the BoNT C-D mosaic protein (BoNT/CD), a BoNT subtype that is essentially a hybrid of the BoNT/C ({approx}two-third) and BoNT/D ({approx}one-third) serotypes. While the amino acid sequence of the heavy chain receptor binding (HCR) domain of BoNT/CD (BoNT/CD-HCR) is very similar to the corresponding amino acid sequence of BoNT/D, BoNT/CD-HCR binds synaptosome membranes better than BoNT/D-HCR. To obtain structural insights for the different membrane binding properties, the crystal structure of BoNT/CD-HCR (S867-E1280) was determined at 1.56 {angstrom} resolution and compared to previously reported structures for BoNT/D-HCR. Overall, the BoNT/CD-HCR structure is similar to the two sub-domain organization observed for other BoNT HCRs: an N-terminal jellyroll barrel motif and a C-terminal {beta}-trefoil fold. Comparison of the structure of BoNT/CD-HCR with BoNT/D-HCR indicates that K1118 has a similar structural role asmore » the equivalent residue, E1114, in BoNT/D-HCR, while K1136 has a structurally different role than the equivalent residue, G1132, in BoNT/D-HCR. Lysine-1118 forms a salt bridge with E1247 and may enhance membrane interactions by stabilizing the putative membrane binding loop (K1240-N1248). Lysine-1136 is observed on the surface of the protein. A sulfate ion bound to K1136 may mimic a natural interaction with the negatively changed phospholipid membrane surface. Liposome-binding experiments demonstrate that BoNT/CD-HCR binds phosphatidylethanolamine liposomes more tightly than BoNT/D-HCR.« less
Posterior Instrumentation Surgery for Craniocervical Junction Instabilities : an Update

The surgical treatment of craniocervical junction (CCJ) instability has recently undergone significant development and change. Posterior instrumentation surgery has been the mainstay of treatment of CCJ instability, and is the focus of this review. For the treatment of atlantoaxial instability, C1-2 transarticular screw fixation has shown good stability, and has been regarded as the "gold standard" procedure. Because of potentially hazardous complications including vertebral artery injury, however, C-1 lateral mass-C-2 pedicle screw fixation is gaining popularity. For treatment of atlantooccipital instability, occipitocervical fixation using screw constructs (combined with either rods or plates) has shown more stability than sublaminar wiring techniques, and has been utilized more frequently. Both innovation in material engineering and in vitro biomechanical studies have contributed significantly to the development of more rigid internal fixation devices, and as a result, many patients who would have been treated conservatively with external orthosis are treated nowadays with instrumentation surgery, resulting in earlier ambulation, shortened hospital stay, and earlier recovery into social activities. New surgical techniques and instruments, however, need to stand the test of time to see whether they are free from long-term adverse events. The rapid turnover of new surgical techniques and hardware has made it difficult for less experienced surgeons to keep up with the latest developments. Conventional techniques can be safer and less technically demanding than newer techniques for those who are not familiar with them.
Gadd153 and NF-κB crosstalk regulates 27-hydroxycholesterol-induced increase in BACE1 and β-amyloid production in human neuroblastoma SH-SY5Y cells.

β-amyloid (Aβ) peptide, accumulation of which is a culprit for Alzheimer’s disease (AD), is derived from the initial cleavage of amyloid precursor protein by the aspartyl protease BACE1. Identification of cellular mechanisms that regulate BACE1 production is of high relevance to the search for potential disease-modifying therapies that inhibit BACE1 to reduce Aβ accumulation and AD progression. In the present study, we show that the cholesterol oxidation product 27-hydroxycholesterol (27-OHC) increases BACE1 and Aβ levels in human neuroblastoma SH-SY5Y cells. This increase in BACE1 involves a crosstalk between the two transcription factors NF-κB and the endoplasmic reticulum stress marker, the growth arrest and DNA damage induced gene-153 (gadd153, also called CHOP). We specifically show that 27-OHC induces a substantial increase in NF-κB binding to the BACE1 promoter and subsequent increase in BACE1 transcription and Aβ production. The NF-κB inhibitor, sc514, significantly attenuated the 27-OHC-induced increase in NF-κB-mediated BACE1 expression and Aβ genesis. We further show that the 27-OHC-induced NF-κB activation and increased NF-κB-mediated BACE1 expression is contingent on the increased activation of gadd153. Silencing gadd153 expression with siRNA alleviated the 27-OHC-induced increase in NF-κB activation, NF-κB binding to the BACE1 promoter, and subsequent increase in BACE1 transcription and Aβ production. We also show that increased levels of BACE1 in the triple transgenic mouse model for AD is preceded by gadd153 and NF-κB activation. In summary, our study demonstrates that gadd153 and NF-κB work in concert to regulate BACE1 expression. Agents that inhibit gadd153 activation and subsequent interaction with NF-κB might be promising targets to reduce BACE1 and Aβ overproduction and may ultimately serve as disease-modifying treatments for AD.
Adjusting for confounding by neighborhood using complex survey data.

Recently, we examined methods of adjusting for confounding by neighborhood of an individual exposure effect on a binary outcome, using complex survey data; the methods were found to fail when the neighborhood sample sizes are small and the selection bias is strongly informative. More recently, other authors have adapted an older method from the genetics literature for application to complex survey data; their adaptation achieves a consistent estimator under a broad range of circumstances. The method is based on weighted pseudolikelihoods, in which the contribution from each neighborhood involves all pairs of cases and controls in the neighborhood. The pairs are treated as if they were independent, a pairwise pseudo-conditional likelihood is thus derived, and then the corresponding score equation is weighted with inverse-probabilities of sampling each case-control pair. We have greatly simplified the implementation by translating the pairwise pseudo-conditional likelihood into an equivalent ordinary weighted log-likelihood formulation. We show how to program the method using standard software for ordinary logistic regression with complex survey data (e.g. SAS PROC SURVEYLOGISTIC). We also show that the methodology applies to a broader set of sampling scenarios than the ones considered by the previous authors. We demonstrate the validity of our simplified implementation by applying it to a simulation for which previous methods failed; the new method performs beautifully. We also apply the new method to an analysis of 2009 National Health Interview Survey (NHIS) public-use data, to estimate the effect of education on health insurance coverage, adjusting for confounding by neighborhood. Copyright © 2011 John Wiley & Sons, Ltd.
A review of surface and interfacial adhesion in wood science and related fields

The study of adhesion in wood and wood-based products becomes increasingly important as work continues toward greater utilization of our total forest resources. The present quality of adhesively bonded wood products will be improved in order to achieve bond quality that harnesses the full strength of wood and, more importantly, leads to greatly enhanced bond durability. These goals will primarily be reached through developing a chemically-anchored bond interface and resin systems that are more flexible and compatible in the cured state.
Effect of Cytidine on Membrane Phospholipid Synthesis in Rat Striatal Slices

Using rat striatal slices, we examined the effect of cytidine on the conversion of [ 3 H]choline to [ 3 H]phosphatidylcholine ([ 3 H]PC), and on net syntheses of PC, phosphatidylethanolamine (PE), and phosphatidylserine, when media did or did not also contain choline, ethanolamine, or serine. Incubation of striatal slices with cytidine (50-500 μM) caused dose-dependent increases in intracellular cytidine and cytidine triphosphate (CTP) levels and in the rate of incorporation of [ 3 H]choline into membrane [ 3 H] PC. In pulse-chase experiments, cytidine (200 μM) also increased significantly the conversion of [ 3 H]choline to [ 3 H]PC during the chase period. When slices were incubated with this concentration of cytidine for 1 h, small (7%) but significant elevations were obsened in the absolute contents (nmol/mg of protein) of membrane PC and PE (p<0.05), but not phosphatidylserine, the synthesis of which is independent of cytidine-containing CTP. Concurrent exposure to cytidine (200 μM) and choline (10 μM) caused an additional significant increase (p<0.05) in tissue PC levels beyond that produced by cytidine alone. Exposure to choline alone at a higher concentration (40 μM) increased the levels of all three membrane phospholipids (p<0.01); the addition of cytidine, however, did not cause further increases. Concurrent exposure to cytidine (200 μM) and ethanolamine (20 μM) also caused significantly greater elevations (p<0.05) in tissue PE levels than those caused by cytidine alone. In contrast, the addition of serine (500 μM) did not enhance cytidine's effects on any membrane phospholipid. Exposure to serine alone, however, like exposure to sufficient choline, increased levels of all three membrane phospholipids significantly (p<0.01). These data show that exogenous cytidine, probably acting via CTP and the Kennedy cycle, can increase the synthesis and levels of membrane PC and PE in brain cells
Discrimination and Acculturative Stress Among First-Generation Dominicans

The present study examined the relationship between discriminatory experiences and acculturative stress levels among a sample of 283 Dominican immigrants. Findings from a linear regression analysis...
IN02, A Positive Regulator of Lipid Biosynthesis, Is Essential for the Formation of Inducible Membranes in Yeast

Expression of the 180-kDa canine ribosome receptor in Saccharomyces cerevisiae leads to the accumulation of ER-like membranes. Gene expression patterns in strains expressing various forms of p180, each of which gives rise to unique membrane morphologies, were surveyed by microarray analysis. Several genes whose products regulate phospholipid biosynthesis were determined by Northern blotting to be differentially expressed in all strains that undergo membrane proliferation. Of these, the INO2 gene product was found to be essential for formation of p180-inducible membranes. Expression of p180 in ino2Δ cells failed to give rise to the p180-induced membrane proliferation seen in wild-type cells, whereas p180 expression in ino4Δ cells gave rise to membranes indistinguishable from wild type. Thus, Ino2p is required for the formation of p180-induced membranes and, in this case, appears to be functional in the absence of its putative binding partner, Ino4p.