cssi/SciSciGPT-SciSciNet huggingface dataset:
Evidence for excitatory actions of histamine on supraoptic neurons in vitro: Mediation by an H1-type receptor

Abstract The effects of histamine on the firing of supraoptic neurosecretory neurons in the rat were examined in vitro using acutely prepared, hypothalamo-neurohypophysial explants perifused with an artificial cerebrospinal fluid. Extracellular action potentials meeting the criteria of antidromic invasion from neurohypophysial stalk stimulation were recorded from 135 neurons in the tuberal portion of the supraoptic nucleus, which lies superficially along the tuber cinereum and consists of mostly vasopressincontaining neurons. Units could be classified as slow/silent (76.3%), phasic (21.5%) or continuous (2.2%) on the basis of their spontaneous activity. Histamine applied briefly to the perifusate excited approximately one-third of the slow silent neurons and approximately two-thirds of the phasic neurons, with a wide range (10−3-10−9) in the effective concentration across neurons. The H1-receptor agonists 2-pyridylethylamine and 2-thiazolylethylamine mimicked these excitations in 10 of 12 and 3 of 6 neurons tested, respectively. The H2-receptor agonists dimaprit (4 neurons) and impromidine (5 neurons) failed to excite any of the tested neurons previously excited by histamine. The H1-receptor antagonist promethazine antagonized histamine's excitatory effect in 8 of 9 cells, while the H2-receptor antagonist cimetidine had little effect on the 9 cells tested. Histamine also modified bursts of activity induced in some slow/silent neurons by antidromic stimulation without having an observable effect in the absence of an antidromic burst. In 10 of 18 neurons histamine produced an elongation of burst duration and a modest increase in intraburst firing rate when applied during an antidromically evoked burst. In an additional 5 of 17 neurons, which had neither previously responded to histamine nor shown an antidromically-evoked burst, the pairing of histamine application and antidromic shocks resulted in an antidromically evoked burst. The effects of histamine on evoked bursts also appeared to be mediated by an H1-receptor. Histamine's excitation of supraoptic neurons is thus dependent on the electrical activity expressed by the neuron at the time of testing. Conductances activated by depolarization of the neuron may be modified by histamine or this compound may alter the threshold for burst generation. Considered with data showing H1-receptor localization and histamine-immunoreactive fibers within the supraoptic nucleus, the present results, as well as those showing the potency of centrally applied histamine in releasing vasopressin, suggest histamine may act physiologically by altering the electrical activity of vasopressin-secreting neurons.
Numerical studies of the trapping of Frenkel excitons in one-dimensional systems

Abstract Numerical studies of the trapping of Frenkel excitons on a one-dimensional lattice are reported. The effects of trapping are introduced through a non-Hermitian decay term in the Hamiltonian. Each of the traps, which are assumed to occupy interstitial positions, can receive excitation from a single center. The equations of motion for the exciton correlation functions of a finite array of centers are integrated to obtain the decay of the k = 0 mode and the probability of finding an exciton in any mode, following excitation of the k = 0 mode. Results for the latter are compared with the predictions of calculations by Hemenger and Pearlstein.
Who is black, white, or mixed race? How skin color, status, and nation shape racial classification in Latin America.

Comparative research on racial classification has often turned to Latin America, where race is thought to be particularly fluid. Using nationally representative data from the 2010 and 2012 America’s Barometer survey, the authors examine patterns of self-identification in four countries. National differences in the relation between skin color, socioeconomic status, and race were found. Skin color predicts race closely in Panama but loosely in the Dominican Republic. Moreover, despite the dominant belief that money whitens, the authors discover that status polarizes (Brazil), mestizoizes (Colombia), darkens (Dominican Republic), or has no effect (Panama). The results show that race is both physical and cultural, with country variations in racial schema that reflect specific historical and political trajectories.
Anatomical Variations of the Spine in the Horse

The vertebral counts of the thoracic, lumbar and sacral spines of 190 horses and of the sacral and lumbar spines of 256 horses and classified into 9 species are given and the variations are shown. The cervical spine always had 7 vertebrae. While 18 is the usual number of thoracic vertebrae, 17 were found in 18 and 19 in 11 of 190 specimens. Nineteen thoracic vertebrae were found in only 11 of the specimens but of these 11 instances, 9 occurred among 32 spines of the Prjevalsky horse. The domestic horse, Shetland pony, zebras, Arabian horses and hybrids normally have 6 lumbar vertebrae, the donkeys and hemiones have 5 but exceptions were found in all classes. The Prjevalsky horse has 5, or 6 equally divided. It may be proper to think of the Prjevalsky horse as having normally 6 lumbar vertebrae with a high incidence of dorsalization of L1. The sacra usually have 5 vertebrae, this number having been counted 176 times, but 4 vertebrae were counted 49 times and 6 vertebrae 9 times. Caudal vertebrae are often fused with the sacrum making a single functional unit. If such fused caudal vertebrae and transitional sacro-caudal vertebrae are counted as parts of the sacra, of 52 horses with 5 lumbar vertebrae, 2 had 4, 30 had 5, 16 had 6 and 4 had 7 sacral segments; of 180 horses with 6 lumbar vertebrae, 18 had 4, 110 had 5, 44 had 6 and 8 had 7 sacral segments. Horses with 5 lumbar vertebrae had longer sacra, average 5.41, than horses with 6 lumbar vertebrae, average 5.23. The shortest sacra were found in Shetland ponies, horses, Arabians and Prjevalsky horses. The longest sacra were found in Grevy zebras, zebras, donkeys and hemiones. Variation in one portion of the spine results in compensating changes in the neighboring areas.
Note on the viscous smoothing of the discontinuities in an inviscid model of abyssal circulation

Abstract Calculations for the thermohaline circulation for an inviscid model over the slope regions of a homogeneous and of a two-layer system with sloping western and northern boundaries and driven by uniform upwelling through the thermocline were carried out by Andersson and Veronis [2004. Thermohaline circulation in a two-layer model with sloping boundaries and mid-ocean ridge. Deep-Sea Research Part I 51, 93–106]. The results showed discontinuities in certain regions of the flow over the western and northern slopes where inviscid flows from different regions merged. A speculation that those discontinuities would be smoothed over when friction is added to the model is verified here in a numerical calculation for the homogeneous model in which the value of friction ranges over three orders of magnitude. The inviscid solution is approached as friction is reduced. The conclusion is that obtaining a solution using an inviscid model over the slope regions is a valid first step in solving a problem of this type.
Sequential estimation for continuous-time linear dynamic systems with completely unknown inputs and duality with singular control

Completely unknown but deterministic (or Fisher-nnknown) inputs often occur in practice and are approximated by Gauss-Markov processes in applying Kalman-Bucy filtering results. In this paper, the exact filtering equations for such inputs are presented in terms of an information-form filter. The equations are obtained by a limit procedure from the corresponding equations for discrete-time systems. Using duality arguments, the necessary and sufficient conditions for singular control problems are shown to follow from these results.
Integrated Lyrical Writing: Addressing Writing via Ballads.

Using songs in a language class takes advantage of the natural connection between students and music. This article describes a project that develops writing and speaking through song, using technology to help build students' knowledge of U.S. culture as well as their ability to communicate using descriptive, narrative, and expository rhetorical styles. The project consists of a series of assignments designed for a class of English as a second language students at the intermediate proficiency level in a university academic preparation program. The project has a humanities focus, involving students in connecting songs with social and historical issues in U.S. culture. Teachers can easily expand or adapt the project in regard to content and concepts, language proficiency levels, targeted language skills, and age group to support any textbook or curriculum.
BSTA Promotes mTORC2-Mediated Phosphorylation of Akt1 to Suppress Expression of FoxC2 and Stimulate Adipocyte Differentiation

Phosphorylation and activation of Akt1 is a crucial signaling event that promotes adipogenesis. However, neither the complex multistep process that leads to activation of Akt1 through phosphorylation at Thr308 and Ser473 nor the mechanism by which Akt1 stimulates adipogenesis is fully understood. We found that the BSD domain–containing signal transducer and Akt interactor (BSTA) promoted phosphorylation of Akt1 at Ser473 in various human and murine cells, and we uncovered a function for the BSD domain in BSTA-Akt1 complex formation. The mammalian target of rapamycin complex 2 (mTORC2) facilitated the phosphorylation of BSTA and its association with Akt1, and the BSTA-Akt1 interaction promoted the association of mTORC2 with Akt1 and phosphorylation of Akt1 at Ser473 in response to growth factor stimulation. Furthermore, analyses of bsta gene-trap murine embryonic stem cells revealed an essential function for BSTA and phosphorylation of Akt1 at Ser473 in promoting adipocyte differentiation, which required suppression of the expression of the gene encoding the transcription factor FoxC2. These findings indicate that BSTA is a molecular switch that promotes phosphorylation of Akt1 at Ser473 and reveal an mTORC2-BSTA-Akt1-FoxC2–mediated signaling mechanism that is critical for adipocyte differentiation.
Modules to enhance smart lighting education

ABSTRACT Over the past several years there has been a rapid advancement in solid state lighting applications brought on by the development of high efficiency light emitting diodes. Development of lighting devices, systems and products that meet the demands of the future lighting market place requires workers from many discip lines including engi neers, scientists, designers and architects. The National Sc ience Foundation has recognized this fact and established the Smart Lighting Engineering Research Center that promotes research leading to smart lighting systems, partners with industry to enhance innovation and educates a diverse, world-class workforce. The lead institution is Rensselaer Polytechnic Institute with core partners Boston University and The University of New Mexico. Outreach partners include Howard University, Morgan State University, and Rose-Hulman Institute of Technology. Because of the multidisciplinary nature of advanced smart lighting systems workers often have little or no formal education in basic optics, lighting and illumination. This paper describes the initial stages of the development of self-contained and universally applicable educational modules that target essential optics topics needed for lighting applications. The modules are intended to be easily incorporated into new and existing courses by a variety of educators and/or to be used in a series of stand-alone, asynchronous training exercises by new graduate students. The ultimate goal of this effort is to produce resources such as video lectures, video presentations of students-teaching-students, classroom activities, assessment tools, student research projects and laboratories inte grated into learning modules. Sample m odules and resources will be highlighted. Other outreach activities such as plans for coursework, undergraduate research, design projects, and high school enrichment programs will be discussed. Keywords: Optics education, Lighting education, Course modules
Anaphylatoxin C5a fails to promote prostacyclin release in cultured endothelial cells from human umbilical veins.

Abstract Subcultured endothelial cells from human umbilical veins respond to histamine and melittin with increased prostacyclin production, measured as 6-keto-prostaglandin F1α by radioimmunoassay. However, no response to leukotriene C4 was observed. Primary cultured cells, on the other hand, respond to leukotriene C4 and the histamine response was 7 times more potent for these cells than for subcultured cells. In contrast, neither primary cultures nor subcultures of endothelial cells released prostacyclin following application of either human anaphylatoxin C5a (100 nM) or C3a (1 μM). In addition, these endothelial cells appear to have no specific binding sites for 125I-C5a. However, endothelial cells released prostacyclin in the presence of human polymorphonuclear leukocytes that were activated with C5a. We conclude that involvement of endothelial cells in the haemodynamic response to anaphylatoxin is an indirect function, i.e. C5a activates circulating or tissue cells which in turn stimulate the endothelial cell to produce prostacyclin.
Disentangling the Effects of Racial and Weight Discrimination on Body Mass Index and Obesity Among Asian Americans

Objectives. We examined whether racial discrimination is associated with increased body mass index (BMI) and obesity among Asian Americans. Further, we explored whether this association strengthens with increasing time in the United States.Methods. We analyzed data from the 2002 to 2003 National Latino and Asian American Study (n=1956). Regression models tested whether reports of racial discrimination were associated with BMI and obesity, after accounting for weight discrimination, age, gender, marital status, ethnicity, generation, employment, health status, and social desirability bias (the tendency to seek approval by providing the most socially desirable response to a question).Results. We found that (1) racial discrimination was associated with increased BMI and obesity after we controlled for weight discrimination, social desirability bias, and other factors and (2) the association between racial discrimination and BMI strengthened with increasing time in the United States.Conclusions. Racial discri...
Pair production in Al, Sn, Ta and Au by 2.62 MeV gamma rays

Abstract The pair-production cross sections of Al, Sn, Ta and Au at 2.62 MeV have been measured in terms of the differential Compton scattering cross section at the same energy. The measured cross sections are (in b) 0.059±0.010, 0.98±0.06, 2.32±0.13 and 2.89±0.15 for Al, Sn, Ta and Au, respectively. These cross sections and the dependence upon atomic number of the cross sections are in close agreement with the results of Dayton.
Perfluorochemical reperfusion yields improved myocardial recovery after global ischemia

Abstract Reperfusion injury remains a limiting factor in extending ischemic storage time for human heart transplantation. In this study, initial myocardial reperfusion with an oxygenated perfluorochemical (Fluosol) was investigated as a means of limiting such injury. Neonatal piglet hearts were arrested with crystalloid cardioplegia, excised, and stored for 12 hours in saline solution at 0 °C. Initial reperfusion (10 minutes) was either with whole blood (n = 6), unmodified perfluorochemical (n = 8), or aspartate/ glulamate-enriched perfluorochemical cardioplegia (n = 6), and was followed by an additional 40 minutes of whole blood perfusion. Functional evaluation was then completed, and left ventricular biopsy specimens were taken. A control group (n = 7) was evaluated without an intervening period of ischemia. At a left ventricular end-diastolic pressure of 9 mm Hg, hearts stored in whole blood cardioplegia developed a left-ventricular strok? work index of 3.8 ± 2.3 × 10 3 erg/g (mean ± standard error of the mean). Under the same conditions, perfluorochemical-reperfused hearts achieved a stroke work index of 14.6 ± 1.3 × 10 3 erg/g, significantly greater than that of the whole blood group ( p 3 erg/g, significantly increased over that of the nonenriched perfluorochemical group ( p 3 erg/g). In addition, perfluorochemical-reperfused hearts demonstrated superior maintenance ( p p
Spatial organization of EEGs from olfactory bulb and cortex.

Abstract This report presents evidence for the concept of ‘wave packet’ (Freeman 1975) in the olfactory system. EEG bursts recorded from electrodes chronically implanted at multiple sites in the olfactory bulb and cortex in awake rabbits were spatially coherent, iso-frequency events. Both bulbar and cortical bursts were composed of a major oscillation in the 35–85 c/sec range. The dominant cortical frequency was within 5% of that of the bulb. A secondary oscillation in the 15–35 c/sec range was found in both bulb and cortex. This was thought to represent a feedback signal of the cortex to the bulb.
Integrating Winter Annual Forages into a No-Till Corn Silage System

The benefits of cover crops within crop rotations are well documented, but information is limited on using cover crops for forage within midwestern United States cropping systems, especially under no-tillage management. Our objective was to evaluate plant, animal, and soil responses when integrating winter cover crop forages into no-till corn (Zea mays L.) silage production. Three cover crop treatments were established no-till after corn silage in September 2006 and 2007 at Columbus, OH: annual ryegrass (Lolium multiflorum L.), a mixture of winter rye (Secale cereale L.) and oat (Avena sativa L.), and no cover crop. Total forage yield over autumn and spring seasons was 38 to 73% greater (P ≤ 0.05) for oat + winter rye than for annual ryegrass. Soil penetration resistance (SPR) in May 2007 was 7 to 15% greater (P ≤ 0.10) in the grazed cover crops than in the nongrazed no cover crop treatment; however, subsequent silage corn yield did not differ among treatments, averaging 10.4 Mg ha -1 in August 2007. Compared with the no cover crop treatment, cover crops had three- to fivefold greater root yield, threefold greater soil microbial biomass (MB) in spring 2008, and 23% more particulate organic carbon (POC) concentrations in the 0- to 15-cm soil depth. Integration of forage cover crops into no-till corn silage production in Ohio can provide supplemental forage for animal feed without detrimental effects on subsequent corn silage productivity, with the added benefit of increasing labile soil C.
Stuck data, dead data, and disloyal data: the stops and starts in making numbers into social practices

Indicators with long social histories, such as the Consumer Price Index, often serve as nodes of calculative infrastructures. They create a field of social action, making some relations between people, institutions, and materials possible, and other relations less possible. By reflecting on two experiments in do-it-yourself sensor data, this article explores the tensions that occur when indicators have not yet become stable entities. When the conditions of possibility for the indicator's continued existence are less assured, the labor it takes to build numbers into something socially meaningful becomes surprisingly visible. This labor proceeds in stops and starts, as the various material and epistemological and social resistances reveal themselves. Sensors shape these starts and stops. Sensors give their users an indication of a possible whole entity whose contents they cannot fully imagine, and either must create or abandon. Far from producing certainty, sensor data often provokes a sense of vagueness th...
The third joint of the canine jaw

The dog mandible has three joints — two temporomandibular and one symphyseal joint. In studies of jaws and their mechanics usually only the temporomandibular joints are considered. The symphysis is consistently neglected and because of this, remarkable features of the temporomandibular joints have never been noted. The symphysis has special connective tissue arrangements and its own vascular and nerve supply. Along the anterosuperior part of the symphysis, a strip of fibrocartilage, and running more or less parallel to it, strong cruciate ligaments bind the symphyseal plates together. Small arteries run into the symphyseal joint and it is drained by an anastomosing venous plexus. The posterior, ligamentous, portion is laced with a profuse network of nerves. The temporomandibular joint is unusual in that its joint disc is powerfully anchored to the skull medially and to the outer pole of the mandibular condyle laterally. The temporomandibular joint disc thus acts as a ligament that halts lateral movement of the condyle just as the carnassial teeth are aligned for cutting function. As the mandible moves laterally, the space between the posterior ends of the symphyseal plates widens: at the same time it narrows anteriorly. The cruciate ligaments control this movement and stabilize the symphyseal joint by preventing direct lateral displacement of the symphyseal plates. The fibrocartilage cushions this movement and also mediates rotational movements about the longitudinal axis of the mandible when crushing molar teeth come into function.
The Common Role Structure Improved Blockmodeling Methods Applied to Two Communities' Elites

The claim by Breiger and Pattison (1978) that the joint homomorphic reduction indicates the role structure common to two populations is shown to be incorrect. The actual common role structure is defined and then calculated for the elites of two communities. A new measure of the similarity of two role structures is also provided. The results show that, in contradiction to Breiger and Pattison's claims, the two community elite role structures do not share relative strength of ties and are, in fact, very different from one another.
Cerebrospinal fluid and nerve conduction abnormalities in HIV positive individuals.

We studied whether there was an association between nerve conduction studies (NCS), CSF, and CD4-T lymphocyte parameters in a large cohort of HIV positive individuals. Two hundred and twenty-eight HIV positive individuals underwent motor and sensory nerve conduction studies, CSF evaluation, peripheral CD4-T lymphocyte count, and neurologic evaluation to determine the presence or absence of peripheral neuropathy. We compared NCS of HIV positive subjects with and without abnormal CSF parameters in the entire cohort. We also compared CSF parameters in a subset of CD4-matched patients with and without neuropathy. CSF abnormalities (in excess of laboratory norms) occured frequently in the entire study group. There was no statistically significant relationship between NCS and CSF parameters. In addition, there was no significiant difference in the CSF findings in the group of patients with clinical neuropathy compared to the group without neuropathy. However, there was an association (p < 0.05) between lower CD4 counts and NCS parameters. In general, abnormal CSF findings are not associated with deteriorating peripheral nerve function in HIV infected patients and are just as likely to be found in an HIV positive patient whether or not a peripheral neuropathy is present.
Rethinking Well-Child Care

Well-child care is a core service of pediatrics, but it receives little emphasis in pediatric training, reluctant consideration by insurers, and rare attention from researchers. Although it encompasses a variety of health-promoting and disease-preventing services, the desired outcomes of well-child care and quality standards for its provision have not been specified. It is not surprising, then, that preventive care services, as they are being provided currently, are not meeting the needs of many families, especially families with the most vulnerable children. The quality of child health supervision varies greatly among physician practices, and parents are signaling their dissatisfaction by failing to obtain approximately one-half of recommended preventive care services. In addition, evidence of effectiveness is lacking for much of the content of well-child care, which may jeopardize both its place as a covered insurance benefit and its reimbursement. It is time for major revision of well-child care, taking into account the varying needs of individual children and families, the operation of child health care practices, and the broad issues of access to primary care and payment for services within the US health care system. Because preventive health care for children, at least as it occurs within well-child visits, is authoritatively guided by the American Academy of Pediatrics (AAP) Recommendations for Preventive Pediatric Health Care ,1 otherwise known as the periodicity schedule, review and revision of well-child care must begin with that document. Historically, the field of pediatrics has been as concerned with promoting children’s health and development as with treating children’s diseases.2 The current need to return to this holistic approach is evident in the trends in children’s health status. Children’s physical health is better than it ever has been.3 Scientific progress has led to substantial reductions in many of the acute morbidities of the early 20th …
Comparative kinetic studies of cytochromes c in reactions with mitochondrial cytochrome c oxidase and reductase

Kinetic studies of the reactions of selected eukaryotic and prokaryotic cytochromes c with mitochondrial cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase (EC 1.9.3.1) using a standardized complex IV preparation from beef heart are reported. Data on reactions with NADH-linked cytochrome c reductase (complexes I and III) are included. The concentration ranges employed provide a basis for quantitative demonstration of a general rate law applicable to oxidase reactions of cytochrome c of greatly differing reactivities. Results are interpreted on the basis of a modified Minnaert mechanism (Minnaert, K. (1961) Biochim. Biophys. Acta 50, 23), assuming productive complex formation between cytochrome c and free oxidase in addition to further complex binding of a second cytochrome c molecule to the initially formed oxidase complex. Kinetic constants so obtained are consistent with the assumption that binding is the dominant parameter in reactivity, and can be rationalized most simply on this basis.
Development of laser deposition package for modeling of EUV sources for microlithography

A laser energy deposition model has been incorporated into the MHRDR-EUVL magnetohydrodynamic (MHD) model of EUV sources for microlithography. The model includes inverse-bremsstrahlung absorption, resonance absorption, and reflection of laser radiation from the plasma critical surface. The plasma evolution is simulated in parallel with the MHRDR-EUVL (Magneto-Hydro-Radiative-Dynamic-Research) 2D, three-temperature, MHD computer code. Convenient user-options include simple specification of the full width at half maximum (FWHM) of typical laser profiles, such as Gaussian profiles in space and time. The new laser deposition capability will allow MHRDR-EUVL to calculate the evolution of magnetized laser-produced plasmas. Magnetic fields can reduce the loss of plasma energy caused by plasma expansion and thermal conductivity.
Distribution of flavonoids in twenty-one species of Oenothera

Abstract Distributional data for 12 flavonoids in 23 taxa of Oenothera , 2 species of Calylophus , and 1 species of Gaura are presented.
Dual Roles for the Phosphatase PPM1D in Regulating Progesterone Receptor Function

Although protein phosphatase magnesium-dependent 1 δ (PPM1D) was initially characterized as a p53-regulated phosphatase responsible for inactivation of p38 MAPK and consequent inactivation of p53, its overexpression and amplification in human breast cancers led us to assess its role in steroid hormone action. We found that PPM1D stimulated the activity of several nuclear receptors including the progesterone receptor (PR) and estrogen receptor. Although p38 MAPK inhibited PR activity, PPM1D stimulation of PR activity was greater than that achieved by a chemical inhibitor of p38 MAPK, SB202190. This suggests an additional novel function for PPM1D. Consistent with this, the transcriptional activity of endogenous PR in MCF-7 breast cancer cells was preferentially inhibited by small interfering RNA for PPM1D; SB202190 failed to reverse the inhibition. Although PPM1D phosphatase activity was required for stimulation of transcriptional activity, the activity of a PR phosphorylation site null mutant was enhanced by PPM1D, indicating that PR is not the direct target. Additional studies revealed that PPM1D enhanced the intrinsic activity of p160 coactivators such as steroid receptor coactivator-1 and promoted the interaction between PR and steroid receptor coactivator-1 in a mammalian two-hybrid assay. Neither activity was induced by SB202190. Although PPM1D stimulated PR activity in part through inhibition of p38 MAPK, its primary action is novel and independent of p38 MAPK. Thus, we speculate that PPM1D promotes breast tumor growth both by inhibiting p53 activity and by enhancing steroid hormone receptor action.
Fair value accounting: A guide to understanding the current standards

Will all financial assets and liabilities soon be measured at fair value? © 1999 John Wiley & Sons, Inc.
Ongoing sexually transmitted disease acquisition and risk-taking behavior among US HIV-infected patients in primary care: implications for prevention interventions.

Background:To better understand the factors associated with HIV- and sexually transmitted disease (STD)-transmitting behavior among HIV-infected persons, we estimated STD prevalence and incidence and associated risk factors among a diverse sample of HIV-infected patients in primary care.Methods:We a
Articles You May Have Missed

In this issue of the Journal of Medical Toxicology, a new feature section entitled “Articles You May Have Missed” is introduced. The goal of this new section is to highlight articles from non-mainstream toxicology journals that may impact the practice of toxicology. The selected articles will cover a broad range of topics within the scope of toxicology including basic science, environmental/occupational exposures, and acute care toxicology. The format consists of a structured synopsis, brief critique, and comments on the potential implication of the information for medical toxicologists. Four articles will be presented in each issue.
Bioavailability of Δ⁹-tetrahydrocannabinol following intranasal administration of a mucoadhesive gel spray delivery system in conscious rabbits.

Background: The purpose of this study was to investigate the potential of the intranasal route for systemic delivery of solubilized Δ9-tetrahydrocannabinol (THC). A further aim was to investigate the effect of nasally administered chitosan-based nasal bioadhesive gel on THC bioavailability as a formulation strategy to decrease normal mucociliary drug clearance. Method: The THC formulations were administered intranasally and compared to intravenous administration utilizing conscious rabbits. Results: After nasal administration, the THC nasal solution afforded a Cmax value of 20 ± 3 ng/mL at 20 minutes. Interestingly, the THC loaded in chitosan gel formulation followed almost the same profile at early time points and subsequently afforded a higher Cmax value of 31 ± 4 ng/mL (Tmax = 45 minutes). The absolute bioavailability of THC after nasal delivery was studied to compare plasma THC concentrations after nasal administration with those after intravenous injection. Absolute bioavailability values were 13.3...
Spectral Interferences in Secondary Ion Mass Spectrometry

The nature and origin of secondary ions resulting from the ion bombardment of a solid have been studied. In addition to the desired singly charged monoatomic ions, five other ion types are described in terms of their potential as spectral interferences. Except for the multiply charged ions, these interferences are molecular ions resulting from inter- and intraelement combinations. Instrumental parameters such as primary ion species, spectral polarity, and spectral resolution are shown to reduce the influence of these molecular ions.
Integrable digital pulse rate doubler

A pulse rate doubling technique for periodic digital signals is described. This circuit is fully compatible with silicon bipolar integrated circuit (IC) technology; no discrete capacitors are required. The difference in storage times between an n-p-n transistor and lateral p-n-p transistor is used to generate the output pulse sequence.
The Latency of Exocytosis Varies with the Mechanism of Stimulated Release in PC12 Cells.

Abstract : To compare the time course of different mechanisms of chemically stimulated release, amperometric detection of dopamine was carried out at single PCl2 cells. The rapid response of carbon fiber microelectrodes allowed the detection of single exocytotic events thus providing time-resolved information about the dynamics of stimulated release, in particular the latency between the stimulation of a cell arid the secretion of catecholamines. Upon rapid depolarization of the cell membrane caused by application of 105 mM K+, almost immediate (6 + or - s) release of dopamine was observed. Stimulation with 1 mM nicotine, involving the stimulant binding to a ligand-gated ion channel, resulted in a short (37 + or - 5 s) delay between stimulation and secretion. The application of 1 mM muscarine to the cells caused a long (103 + or - 11 s) latency before exocytosis was detected. A biphasic response that appeared to be similar to a combination of nicotine- and muscarine- stimulated release was observed when cells were stimulated with 10 mM acetylcholine. Thus it appears that the dynamics of stimulated release at single PC 12 cells is significantly affected by the mechanism leading to exocytosis.
Classically conditioned bradycardia and skeletal-motor activity in restrained rats

Classical conditioning of heart rate (HR) and skeletal-motor activity in restrained rats was ex­ amined using a single, brief (.5-msec) pulse of shock to the rat's tail as both the CS and US. Elec­ tric shock was selected as a CS to discourage behavioral freezing and to provide an above-zero level of movement activity for evaluating the presence of conditioning. Three CS intensities and two US intensities were combined in a factorial design creating six separate experimental groups which received 50 paired trace conditioning trials at a CS-US interval of 8.1 sec. Three control groups were given 50 unpaired presentations of one of the CSs and the highest intensity US. All of the experimental groups showed the development of a bradycardia CR in the absence of a conditioned change in movement. During conditioning, HR and movement to CS onset varied together in both the experimental and control groups. Other examples of a close correspondence between HR and movement included some, but not all, of the preconditioning CS-alone responses, the URs, and shifts in baselines. The results suggested that although some nonassociatively based HR changes may have been tied to movement, the conditioned bradycardias in the experimental groups appeared to be relatively independent of movement. Studies showing that changes in heart rate (HR) may covary directly with increases or decreases in skeletal­ motor activity (Obrist et al., 1974) have led to the proposal (Obrist, 1981) that HR responses in a variety of behavioral situations may be tightly tied to movement through well-known (Rushmer, 1976) cardiac­ somatomotor pathways within the central nervous system. Many of the studies showing a close correspondence be­ tween HR and movement have involved instrumental paradigms in which HR was measured while the subject received contingent reinforcement for changes in overt responding. The complexity of these paradigms and the absence of control procedures to evaluate the possible in­ fluences of nonassociative factors, such as sensitization and pseudoconditioning, have made it difficult to deter­ mine whether the HR changes accompanying movement were learned or nonspecific in nature. That the relationship between learned HR responses and gross body movement may not be a simple one is sug­ gested by the outcomes of aversive classical condition­ ing studies. A number of these studies have shown that although HR CRs (tachycardias as well as bradycardias) may at times covary with and be augmented in the presence of directionally similar changes in overt move­ ment, the HR CRs are also seen in the absence of any
An Improved Streamline Curvature Approach for Off-Design Analysis of Transonic Axial Compression Systems

Abstract : A streamline curvature (SLC) throughflow numerical model was assessed and modified to better approximate the flow fields of highly transonic fans typical of military fighter applications. Specifically, improvements in total pressure loss modeling were implemented to ensure accurate and reliable off-design performance prediction. The assessment was made relative to the modeling of key transonic flow field phenomena, and provided the basis for improvements, central to which was the incorporation of a physics-based shock loss model. The new model accounts for shock geometry changes, with shock loss estimated as a function of inlet relative Mach number, blade section loading (flow turning), solidity, leading edge radius, and suction surface profile. Other improvements included incorporation of loading effects on the tip secondary loss model, use of radial blockage factors to model tip leakage effects, and an improved estimate of the blade section incidence at which minimum loss occurs. Data from a single-stage, isolated rotor and a two-stage, advanced-design (low aspect ratio, high solidity) fan provided the basis for experimental comparisons. The two-stage fan was the primary vehicle used to verify the present work. Results from a three-dimensional, steady, Reynolds-averaged Navier-Stokes model of the first rotor of the two-stage fan were also used to compare with predicted performance from the improved SLC representation. In general, the effects of important flow phenomena relative to off-design performance of the fan were adequately captured. These effects included shock loss, secondary flow, and spanwise mixing. Most notably, the importance of properly accounting for shock geometry and loss changes with operating conditions was clearly demonstrated. The majority of the increased total pressure loss with loading across the important first-stage tip region was shown to be the result of increased shock loss, even at part-speed.
Coupling of translational and reactive dynamics for a simple lattice model

The problem of the coupling of translational and reactive dynamics is investigated in terms of a simple lattice model. A master equation description including repulsive and reactive interactions is analyzed in terms of a boundary layer region and reduced to source term equations at the diffusion level. Comparison is made at this level with boundary condition approaches.
Comparison of Fabrics Made with Cotton Covered Polyester Staple-Core Yarn and 100% Cotton Yarn:

Cotton covered/polyester staple-core yams [6, 8], recently developed at the Southern Regional Research Center, and conventional 100% cotton yarns of equivalent size were woven and knitted into vari...
Segregation behavior at TGO/bondcoat interfaces

The segregation of sulfur and other elements at the interface between thermally grown alumina and a few coatings have been reviewed and compared with studies made at oxide/metal interfaces formed on model alloys. The coatings studied were NiPtAl on CMSX-4 or AM1 with two different bulk sulfur contents, and NiCoCrAlY on PWA 1484. The segregation behavior at the oxide/PWA1484 interface was also reported. Auger electron microscopy was used to study the chemistry at the oxide/coating interface after portions of the oxide were removed in ultra high vacuum (UHV) by scratches made on the oxidized sample surface. The extent of oxide spallation in relation to the scratch width was utilized to evaluate the interfacial strength, which was then correlated with the interface impurity level. Results showed strong relationship between sulfur segregation and the composition of the alloy substrates. In addition to substrate sulfur content, the degree of sulfur segregation was most significantly increased by Cr co-segregation or decreased by Y doping of the coating. Pt and Hf could stop segregation only when present together. P was found as a significant segregand in one case where sulfur segregation was prevented by Y. These behaviors are discussed in terms of various thermochemical interactions in the bulk and at the interface.
Multi-stage step-wise group screening

Step-wise group screening experiments for classifying members of a population as either good or defective are generalised to more than two stages. An expression for the expected number of tests is obtained and optimum 2, 3 and 4-stage designs are tabulated. By assuming p to be small, an approximation to the expected number of tests is derived which is minimized with respect to the number of groups in each stage. Finally, a new bifurcation technique, seen to be a special case of multi-stage step-wise group screening, is discussed.
Cortical fabrics of Upper Jurassic ooids, Arab Formation, Saudi Arabia: Implications for original carbonate mineralogy

Abstract This study reports the occurrence of partly leached ooids, interpreted to have been originally aragonitic, that still preserve intra-cortical fabric details in the Upper Jurassic of Saudi Arabia. A thin dark layer of insoluble material (probably organic matter) separates adjacent carbonate lamellae. Selective leaching of carbonate occurs in each lamella, yielding intra-cortical moldic porosity. It is the presence of the thin dark layers that allows fabric details to be preserved during and after leaching of the ooids. Locally, the intra-cortical moldic pores may be infilled by finely crystalline equant calcite cement that is interpreted to be of meteoric origin. In all cases, this equant calcite cement has nucleated on top of the underlying dark layer of insoluble material and has grown upward and outward until reaching the next layer. If allowed to go to completion, crystal growth in this fashion will produce a radial fabric, similar to or even mimicking that seen in many ancient ooids. This is an important observation because well-preserved radial fabrics seen in ancient ooids have previously been interpreted to represent original calcite mineralogy. Results from this study suggest that a well-preserved radial calcite fabric may be indicative of either originally aragonite or calcite mineralogy.
Effects of phosphoroamides on nitrification, denitrification, and mineralization of organic nitrogen in soil

Recent work has shown that several phosphorodiamides and phosphorotriamides are potent inhibitors of soil urease activity and have potential value for retarding hydrolysis of fertilizer urea in soi...
Profile and potential of ixabepilone in the treatment of pancreatic cancer

The management of metastatic pancreatic adenocarcinoma is a challenge for medical oncologists because of both the aggressive nature of the disease and the relative paucity of effective systemic treatments with activity against this type of tumor. In the effort to discover new agents and combinations that may augment the therapeutic arsenal available for the management of this cancer, early phase clinical trials have been performed using ixabepilone, an epothilone B analog, with promising results. Targeting the microtubule system with certain taxanes in the management of pancreatic adenocarcinoma has been validated; ixabepilone also targets the microtubule system, interfering with it in an alternate manner from the taxane mechanism. Ixabepilone has demonstrated activity in cancers that have become taxane-resistant as well as those that never had any demonstrable taxane susceptibility. The available data for the use of ixabepilone in the management of pancreatic adenocarcinoma are limited but promising. Single-arm studies have demonstrated both clinical efficacy and tolerable toxicity for the use of ixabepilone as monotherapy. The trial data available for ixabepilone used as a part of combination therapy are similar: it has been paired with chemotherapy (carboplatin, irinotecan) and biologic therapy (dasatinib, sunitinib) at the Phase I level to treat solid tumors in general, again with tolerable side effects and a suggestion of benefit. A single Phase II study has evaluated combination therapy with ixabepilone in the management of patients with pancreatic cancer, pairing it with cetuximab with clinical benefit. Although these trials are promising with regard to addition of ixabepilone to the slim armamentarium for management of pancreatic cancer, further work is still to be done. Importantly, this work bears the burden of not only validating the clinical benefit of ixabepilone, but also of determining whether this benefit is enhanced in any way by combination therapy, and where ixabepilone fits in the sequence of management for patients with metastatic pancreatic cancer.
Development and validation of the college drinking influences survey.

Objective: The authors developed and validated measures of college drinking expectations, psychosocial influences, and values. Participants: Freshmen at college entry (N = 320) and the end of freshman year (N = 420) participated. Methods: The College Drinking Influences Survey, administered in paper and Web-based versions, consists of 3 distinct scales: (1) the College Drinking Expectations Scale assesses expectations for drinking norms and consequences; (2) the Psychosocial Drinking Inventory evaluates social influences, stress, and sensation seeking; and (3) the Drinking Values Scale assesses drinking decisions based on personal choice, social responsibility, and institutional obligation. Results: Factor analysis, interitem reliability, and correlations with existing instruments demonstrated validity and reliability. Differences between the sexes were in predicted directions, and multiple regression using subscale scores as predictors accounted for significant variance in drinking behaviors across the f...