cssi/SciSciGPT-SciSciNet huggingface dataset:
Transcranial Doppler findings during thoracic endovascular aortic repair.

Objective Thoracic endograft placement has become an acceptable treatment alternative to open repair of the thoracic aorta. Cerebral embolization when manipulating the aortic arch during cardiac catheterization is well described, but the influence of thoracic endovascular aortic repair (TEVAR) on this event remains poorly studied. Our aim was to quantify the number of microembolic signals (MES) detected by transcranial Doppler (TCD) during different stages of TEVAR and correlate them with landing zones, subclavian revascularization, and postoperative morbidity and mortality. Methods TCD was used to monitor 20 patients during TEVAR for the treatment of thoracic aortic aneurysms (TAAs) in 17 (85%) patients, followed by three (15%) with chronic type B aortic dissection and one (5%) Crawford type I thoracoabdominal aortic aneurysm (TAAA). Imaging and medical parameters were entered into a combined database. TCD signals were recorded digitally for the entire case. MES, velocities, and pulsatility index values were entered into a combined database. Results The total number of MES calculated for the diagnostic phase before TEVAR placement and during the treatment phase for all cases combined was 1081 and 1141, respectively. The highest MES counts were generated by the pigtail catheter placement during the diagnostic phase and by device placement during the treatment phase. Embolic count to right/left sides was equal overall. In the diagnostic phase, an average of nine MES were seen right/left, whereas during the treatment phase, 45 and 43 MES were seen, respectively, for right/left. A significant association was found between the total number of MES and postoperative stroke, transient ischemic attack (P = .0055), and death (P = .0053). Conclusions TCD can detect microemboli during TEVAR and is able to identify the procedural aspects most associated with cerebral microemboli.
Fundamental group in positive characteristic

Abstract It is shown that the commutator subgroup of the fundamental group of a smooth irreducible affine curve over a countable algebraically closed field of nonzero characteristic is profinite free of countable rank. A description of the abelianizations of the fundamental groups of affine curves over an algebraically closed field of nonzero characteristic is also given.
Rapamycin inhibition of polyposis and progression to dysplasia in a mouse model.

Familial adenomatous polyposis (FAP) is often due to adenomatous polyposis coli (APC) gene germline mutations. Somatic APC defects are found in about 80% of colorectal cancers (CRCs) and adenomas. Rapamycin inhibits mammalian target of rapamycin (mTOR) protein, which is often expressed in human adenomas and CRCs. We sought to assess the effects of rapamycin in a mouse polyposis model in which both Apc alleles were conditionally inactivated in colon epithelium. Two days after inactivating Apc, mice were given rapamycin or vehicle in cycles of two weeks on and two weeks off. Polyps were scored endoscopically. Mice were euthanized at time points or when moribund, and tissue analyses were performed. In other studies, mice with demonstrable Apc-defective colon polyps were given rapamycin, followed by analysis of their colon tissues. The median survival of mice receiving rapamycin treatment cycles was 21.5 versus 6.5 weeks in control mice (p = 0.03), and rapamycin-treated mice had a significantly lower percentage of their colon covered with polyps (4.3+/− 2 vs 56.5+/− 10.8 percent, p = 0.001). Mice with Apc-deficient colon tissues that developed high grade dysplasia treated with rapamycin underwent treatment for significantly longer than mice treated with vehicle (15.8 vs 5.1 weeks, p = 0.003). In Apc-defective colon tissues, rapamycin treatment was linked to decreased levels of β-catenin and Sox9 at 7 weeks. Other effects of rapamycin in Apc-defectivecolon tissues included decreased proliferation and increased numbers of differentiated goblet cells at 7 weeks. Rapamycin did not affect β-catenin-regulated gene expression in cultured intestinal epithelial cells. Rapamycin has potent inhibitory effects in a mouse colon polyposis model, and mTOR inhibition is linked to decreased proliferation and increased expression of differentiation markers in Apc-mutant colon epithelium and delays development of dysplasia. Our findings highlight the possibility that mTOR inhibitors may have relevance for polyposis inhibition approaches in FAP patients.
Measurement of the Mobility of Negative Ions in Saturated Hydrocarbon Liquids with High Electric Fields

A CONSIDERABLE volume of experimental data concerning the problems of high field conductivity and the electrical breakdown in liquid dielectrics is now in existence, and many theories have been proposed to explain these results. Nevertheless it is rather doubtful whether it will be possible to choose the right one without an understanding of the negative charge carriers and their high field mobility. With the exception of the measurements of Chong1, there are no mobility data at high field strengths. On the contrary, a number of papers concerning the mobility of ions in low fields have been published2–5. The most systematic investigations concerning this problem were carried out by I. Adamczewski.
Role of corollary discharge in space constancy.

Visual fixation can be maintained in spite of finger pressure on the monocularly viewing eye. We measured the amount of extraocular muscle effort required to counter the eyepress as the secondary deviation of the occluded fellow eye. Using this method, without drugs or neurological lesions, we have shown that corollary discharge (CD) governs perception of position of a luminous point in darkness, that is, an unstructured visual field. CD also controls visuomotor coordination measured with open-loop pointing and the matching of visual and auditory direction in light and in darkness. The incorrectly biased CD is superseded byvisual position perception in normal structured environments, a phenomenon we call visual capture of Matin. When the structured visual field is extinguished, leaving only a luminous point, gradual release from visual capture and return to the biased CD direction follows after a delay of about 5 sec.
Synergetic Effect of Grit-Blasting and Atmospheric Cold Plasma Pretreatments on the Surface Free Energy of a Fibreglass/Epoxy Vinyl Ester Composite

For the first time, the efficiency of different surface pretreatment approaches prior to adhesive bonding of a fibreglass-reinforced epoxy vinyl ester thermoset composite has been investigated. It was found that grit-blasting generally had a negligible effect on the surface free energy (SFE) calculated using the Owens, Wendt, Rabel, and Kaelble method, as well as the Lifshitz–van der Waals/acid-base (LWAB) approach. However, contrary to abrading, grit-blasting has shown its efficiency to flatten sharp surface irregularities and introduce surface roughness features suitable to adhesive bonding processes. With or without a previous grit-blasting step, argon gas atmospheric cold plasma treatment has shown a slight to moderate efficiency in increasing the SFE polar component of the composite. However, it was found that the addition of 0.07% oxygen to the argon plasma readily allows an important gain in the SFE polar component. Indeed, when processed at a speed of 30 m/min on a previously grit-blasted composit...
Recent forecast skill for the El Niño/Southern Oscillation

We outline a relationship between three slowly varying characteristics of the coupled ocean-atmosphere system in the tropical Pacific: (i) quasi-periodicity, (ii) extended predictability, and (iii) approximate low dimensionality. The Southern Oscillation Index (SOI) and Nino-3 sea surface temperatures characterize climatic variations in the tropical Pacific; these two time series are usually anticorrelated. This low-dimensional characterization suggests that much of the system's seasonal-to-interannual predictability depends on the regular behavior of the two scalar time series under consideration. The predictive skill of two idealized models is studied, showing the strong connection between regularity and predictability. El-Nino/Southern-Oscillation (ENSO) predictability is then assessed for current forecast models. When the periodic component of the ENSO signal is strong, it results in higher forecast skill. This skill decreases when the anti-correlation between SOI and Nino-3 temperature anomalies is lost, as it has been in the first half of this decade.
Tacit Beginnings Towards a Model of Scientific Thinking

The purpose of this paper is to provide an examination of the role tacit knowledge plays in understanding, and to provide a model to make such knowledge identifiable. To do this I first consider the needs of society, the ubiquity of information in our world and the future demands of the science classroom. I propose the use of more implicit or tacit understandings as foundational elements for the development of student knowledge. To justify this proposition I consider a wide range of philosophical and psychological perspectives on knowledge. Then develop a Model of Scientific Knowledge, based in large part on a similar model created by Paul Ernest (Social constructivism as a philosophy of mathematics, SUNY Press, Albany, NY, 1998a; Situated cognition and the learning of mathematics, University of Oxford Department of Educational Studies, Oxford, 1998b). Finally, I consider the work that has been done by those in fields beyond education and the ways in which tacit knowledge can be used as a starting point for knowledge building.
Mutational analyses of light-controlled seedling development in Arabidopsis

Arabidopsis mutants with decreased responses to light and mutants showing light responses in the dark have both been characterized. Some of the former mutants lack specific photoreceptors, such as the red/far-red light receptor phytochrome A, phytochrome B, or a putative blue light receptor, HY4. These have allowed the assessment of physiological functions of these photoreceptors. The mutants with light responses in the dark include some, such as det1 and cop1, that appear to identify light signal transduction components, and others, such as fus6, that may be less directly related to normal control of light responses. Double mutant studies suggest how the different gene products might interact.
Oligodendrogenesis after cerebral ischemia

Abstract Neural stem cells in the subventricular zone (SVZ) of the lateral ventricle of adult rodent brain generate oligodendrocyte progenitor cells (OPCs) that disperse throughout the corpus callosum and striatum where some of OPCs differentiate into mature oligodendrocytes. Studies in animal models of stroke demonstrate that cerebral ischemia induces oligodendrogenesis during brain repair processes. This article will review evidence of stroke-induced proliferation and differentiation of OPCs that are either resident in white matter or are derived from SVZ neural progenitor cells and of therapies that amplify endogenous oligodendrogenesis in ischemic brain.
Many‐body effects in the gain spectra of strained quantum wells

A many‐body theory for the optical susceptibility in highly excited strained‐layer quantum wells is presented. Gain spectra are computed for the example of InxGa1−xAs/InP and different In concentrations, yielding zero, tensile, and compressive strain.
Scanning electron micrographic studies of acrylic resin beads with and without admixtures of antibiotic

Abstract The surface topography of acrylic resin poly(methyl methacrylate) (PMMA) bone cement beads with and without addition of tobramycin has been studied by scanning electron microscopy. Clear differences in the pore size and density were found between the three brands of PMMA bone cement used to fabricate the beads. The addition of the aminoglycoside, tobramycin, had a pronounced effect on the topography of the beads. The differences in surface topography between the beads appeared to account for the observed differences in the leaching rate of tobramycin from the beads.
Improved thermodynamic model for interaction of EDTA with trivalent actinides and lanthanide to ionic strength of 6.60 m

Abstract The dissociation constants of ethylenediaminetetraacetic acid (H4EDTA), and the stability constants of Am3+, Cm3+and Eu3+ with EDTA4− have been determined at 25 °C, over a range of concentration varying from 0.1 to 6.60 m NaClO4 using potentiometric titration and an extraction technique, respectively. The formation of only 1:1 complex, M(EDTA)−, where (M = Am3+, Cm3+ and Eu3+), was observed under the experimental conditions. The observed ionic strength dependencies of the dissociation constants and the stability constants have been described successfully over the entire ionic strength range using the Pitzer model. The thermodynamic stability constant: log β 101 0 = 20.55 ± 0.18 for Am3+, log β 101 0 = 20.43 ± 0.20 for Cm3+ and log β 101 0 = 20.65 ± 0.19 for Eu3+ were calculated by extrapolation of data to zero ionic strength in an NaClO4 medium. In addition, log β 101 0 of 20.05 ± 0.40 for Am3+ was obtained by simultaneously modeling data both in NaCl and NaClO4 media. For all stability constants, the Pitzer model gives an excellent representation of the data using interaction parameters β(0), β(1), and Cϕ determined in this work. The improved model presented in this work would enable researchers to model accurately the potential mobility of actinides (III) and light rare earth elements to ionic strength of 6.60 m in low temperature environments in the presence of EDTA.
Discovering the plant world

The last fifty years have been a time of accelerated plant collection, especially in the tropics. However, this is a race against time since the destruction of natural habitats has also increased dramatically. The rate at which collecting is still adding new species of flowering plants indicates that the inventory is not nearly complete, and that the past estimates of total species numbers are low and should be increased to 320,000. The production of florulas and quantitative inventories of small areas of the tropics, accompanied by intensive fieldwork, has greatly helped to improve the level of inventory. Future collecting should be carefully targeted towards areas that are particularly threatened, such as those defined as hotspots, and also collection of rare species rather than repeated over-collection of widely distributed common taxa. Future collecting should also gather material for ancillary studies such as molecular work and evolutionary development.
Inhibition of cell proliferation in the embryonic myocardium by A1 adenosine receptor activation

A1 adenosine receptors (A1ARs) are expressed in the embryonic heart and influence cardiac function at early developmental stages. To test if A1ARs also affect cardiac structural development, we examined the effects of A1AR activation on heart formation. When pregnant mice were treated with the A1AR agonist, N6-cyclopentyladenosine (CPA), fetuses showed marked reduction of ventricular size and manifested features of heart failure. Suggesting that these findings represent direct effects on embryos, CPA treatment of cultured whole murine embryos resulted in cardiac hypoplasia. When rates of cell division and cell death in the heart were examined, we found decreases in cardiac cell proliferation following A1AR activation. In contrast, no changes in numbers or distribution of apoptotic cells were seen. Collectively, these data show that A1AR activation inhibits cardiac cell proliferation and can lead to cardiac hypoplasia. These data identify adenosine as a potential regulator of cardiac cell division during early development. © 2001 Wiley-Liss, Inc.
The border between cosmetic and reconstructive surgery.

Dr. Nahai has written a comprehensive description of the fuzzy border between cosmetic and reconstructive surgery, to which I would like to add a sharper definition (see Aesthetic Surgery Journal 2010;30:874-875). At my first business meeting of what is now the American Society of Plastic Surgeons, which was attended by a small enough crowd to fit into a schoolroom, I brashly stood and made the following comment: “I cannot see the difference between a nose that is deformed …
Induced formation of ribonucleic acids and plastid protein in Euglena gracilis under the influence of light.

Abstract 1. 1. Euglena cells grown in the light, which possess the photosynthetic apparatus, contain considerably more protein and RNA than the cells grown in the dark. 2. 2. The additional protein of the green cells is localized in the plastid fraction and appears to be part of the chloroplast structure. The additional RNA is distributed among the plastid, microsome and soluble fractions. 3. 3. During chloroplast formation in resting colorless cells exposed to light, the protein of the plastid fraction increases rapidly after a considerable lag period. The RNA of both the plastid and microsome fractions increases without apparent lag; its synthesis ceases before that of the plastid protein. 4. 4. The RNA produced during chloroplast formation may represent specific ribosomal material necessary for the synthesis of the plastid proteins.
Loss of factor XIIIa in pig dermis during tissue expansion

Considerable evidence suggests that factor XIIIa, a blood coagulation factor, also functions in tissue repair, and specifically in the dynamic process of fibroplasia. On the other hand, the dynamic process of tissue expansion would require a loosening of the dermis, the opposite of fibroplasia. We examined the effects of tissue expansion on the expression of factor XIIIa in pig skin. Standard immunohistochemical procedures were used coupled with a rabbit antibody to factor XIIIa. In this report, we demonstrate that the normal expression of factor XIIIa in pig dermis is completely inhibited at the apex overlying the tissue expander. Factor XIIIa inhibition during expansion supports the thesis that this substance is important in the production and maintenance of fibroplasia.
Disseminated mucormycosis in a paediatric patient: Lichtheimia corymbifera successfully treated with combination antifungal therapy

Mucormycosis is a severe fungal infection that largely affects immunocompromised individuals. It carries a high morbidity and mortality rate and is characterised by extensive angioinvasion and necrosis of host tissue. This case report details success in treating disseminated mucormycosis in a paediatric patient with an underlying haematological malignancy. Treatment included institution of combination antifungal therapy with liposomal amphotericin B and caspofungin, aggressive surgical debridement of infected tissue and reversal of underlying immunosuppression.
Providing Support Services for Medical Students on a Rural Regional Medical Campus

One hundred fourteen regional medical campuses (RMCs) are currently recognized by the American Association of Medical Colleges (AAMC). This large number has been the result of the recognized need to train more physicians to serve a growing population and to address the uneven distribution of physicians in North America. Several RMCs were established in less populated regions, with the expectation that many trainees would eventually choose to practice in more rural locales. The Liaison Committee on Medical Education (LCME) mandates that a RMC must provide an academic program for its medical students equivalent to that provided on the main campus and must also provide equivalent support services for medical students. The small, rural RMC of the University of Kansas School of Medicine (KUSM) in Salina was established in 2011 with a mission to train more physicians who would serve rural Kansas. This RMC has successfully implemented an academic program. The authors report how the Salina RMC has satisfied the student support services described in the new standards for accreditation for July 2015.
A 94GHz mm-wave to baseband pulsed-radar for imaging and gesture recognition

An integrated phase-coherent and pixel-scalable pulsed-radar transceiver with on-chip tapered loop antennas generates programmable pulses down to 36ps using an integrated 94GHz carrier, frequency synthesized and locked to an external reference. A DLL controls the TX pulse position with 2.28ps resolution, which allows the chip to function as a unit element in a timed-array. The receiver also features a >1.5THz GBW DA as the front-end amplifier, quadrature mixers, and a 26GHz quadrature baseband. Phase coherency allows for ∼375µm single-target position resolution by interferometry.
STUDIES ON HAEMOPHILUS INFLUENZAE II. A COMPARATIVE STUDY OF THE VIRULENCE OF SMOOTH, ROUGH, AND RESPIRATORY STRAINS OF HAEMOPHILUS INFLUENZAE AS DETERMINED BY INFECTION OF MICE WITH MUCIN SUSPENSIONS OF THE ORGANISM

1. A comparative study of the mucin virulence of smooth, converted rough, and respiratory strains of H. influenzae was carried out in mice. 2. The smooth strains were found to be significantly more virulent than either the converted rough or respiratory strains. 3. The converted rough and respiratory strains were found to be approximately equal in virulence. 4. A diminution in virulence was observed in those smooth strains which had dissociated spontaneously either partially or completely.
Structural requirements of ATP for activation of basal and atrial natriuretic factor-stimulated guanylate cyclase in rat lung membranes.

Abstract ATP has been reported to increase basal and atrial natriuretic factor (ANF)-stimulated guanylate cyclase activity. The structural features of ATP involved in the activation of guanylate cyclase were examined by employing a variety of ATP analogs with modification either at the phosphate chain or at the ribose moiety. Among the natural adenme nucleotides, ATP and ADP were able to increase both basal and ANF-stimulated guanylate cyclase activities in rat lung membranes. AMP had no effect, ATP was more effective than AMPPCP (the non-hydrolyzable analog of ATP), and ADP was more effective than ADPβS and AMPCP (the hydrolysis-resistant analogs of ADP) to increase basal and ANF-stimulated guanylate cyclase activities. Removal of the oxygen atom from the ribose moiety of ATP or ADP significantly reduced their potency. Thus, the length of the phosphate chain and the hydroxyl groups at the ribose moiety are both determinants for nucleotide mediated guanylate cyclase activation.
Statistical inference with partial prior information based on a Gauss-type inequality

Potter and Anderson [1] have developed a Bayesian decision procedure requiring the specification of a class of prior distributions restricted to have a minimal probability content for a given subset of the parameter space. They do not, however, provide a method for the selection of that subset. We show how a generalization of Gauss' inequality can be used to determine the relevant parameter subset.
On a conjecture of jungnickel and tonchev for quasi-symmetric designs

Jungnickel and Tonchev conjectured in [4] that if a quasi-symmetric design D is an s-fold quasi-multiple of a symmetric (v,k,λ) design with (k,(s − 1)λ) = 1, then D is a multiple. We prove this conjecture under any one of the conditions: s ≤ 7, k − 1 is prime, or the design D is a 3-design. It is shown that for any fixed s, the conjecture is true with at most finitely many exceptions. The unique quasi-symmetric 3-(22,7,4) design is characterized as the only quasi-symmetric 3-design, which as a 2-design is an s-fold quasi-multiple with s ≡ 1 (mod k). © 1994 John Wiley & Sons, Inc.
An ionic current model for neurons in the rat medial nucleus tractus solitarii receiving sensory afferent input.

1. Neurons from a horizontal slice of adult rat brainstem were examined using intracellular recording techniques. Investigations were restricted to a region within the nucleus tractus solitarii, medial to the solitary tract and centred on the obex (mNTS). Previous work has shown this restricted area of the NTS to contain the greatest concentration of aortic afferent baroreceptor terminal fields. Electrical stimulation of the tract elicited short-latency excitatory postsynaptic potentials in all neurons. 2. mNTS neurons were spontaneously active with firing frequencies ranging between 1 and 10 Hz, at resting potentials of -65 to -45 mV. These neurons did not exhibit spontaneous bursting activity. 3. Depolarizing current injection immediately evoked a finite, high-frequency spike discharge which rapidly declined to a lower steady-state level (i.e. spike frequency adaptation, SFA). Increasing depolarizations produced a marked increase in the peak instantaneous frequency but a much smaller increase in the steady-state firing level. 4. Conditioning with a hyperpolarizing prepulse resulted in a prolonged delay of up to 600 ms before the first action potential (i.e. delayed excitation, DE) with an attendant decrease in peak discharge rates. DE was modulated by both the magnitude and duration of the prestimulus hyperpolarization, as well as the magnitude of the depolarizing stimulus. Tetrodotoxin (TTX) eliminated spike discharge but had little effect on the ramp-like membrane depolarization characteristic of DE. 5. We have developed a mathematical model for mNTS neurons to facilitate our understanding of the interplay between the underlying ionic currents. It consists of a comprehensive membrane model of the Hodgkin-Huxley type coupled with a fluid compartment model describing cytoplasmic [Ca2+]i homeostasis. 6. The model suggests that (a) SFA is caused by an increase in [Ca2+]i which activates the outward K+ current, IK,Ca, and (b) DE results from the competitive interaction between the injected depolarizing current and the hyperpolarization-activated transient outward K+ currents, IA and ID. 7. We conclude that our ionic current model is capable of providing biophysical explanations for a number of phenomena associated with brainstem neurons, either during spontaneous activity or in response to patterned injections of current. This model is a potentially useful adjunct for on-going research into the central mechanisms involved in the regulation of both blood pressure and ventilation.
Evaluation of student performance in the four-year study of expanded functions for dental hygienists at the University of Iowa.

The performance of certain expanded functions by 48 dental and 48 dental hygiene students was compared. A comparison was made of the quality of selected operative and periodontal procedures completed by 48 expanded-function dental hygiene and 48 senior dental students. Groups of three dental examiners independently evaluated Class II and Class III cavity preparations and restorations, periodontal examinations, treatment plans, and quadrants of root planing and curettage in an examiner-blind format. Dental hygiene students were able to perform the procedures at a level of quality comparable to that of senior dental students.
Nitrogen fixation (acetylene reduction) associated with communities of heterocystous and non-heterocystous blue-green algae in mangrove forests of Sinai

High rates of nitrogen fixation (acetylene reduction) are associated with communities of heterocystous and non-heterocystous blue-green algae, which are widespread and abundant in the coastal mangrove forests of the Sinai Peninsula. Heterocystous forms, particularly representatives of the Rivulariaceae, grow in aerobic environments, where nitrogenase activity may be limited by the availability of nutrients such as Fe and PO4−P. Desiccated communities of Scytonema sp. reduce acetylene within ten minutes of wetting by tidal sea water. Communities dominated by the non-heterocystous Hydrocoleus sp., Hyella balani, Lyngbya aestuarii, Phormidium sp. and Schizothrix sp., occur in close contact with anaerobic sediments and reduce acetylene in the dark as well as in the light. Nitrogen fixation in all these communities is light dependant and may be supplemented by an alternative source of reductant in the dark. The indications are that nitrogen fixation by these communities of blue-green algae, makes a significant contribution to the overall nitrogen input of the mangrove ecosystem.
A genetic algorithm-based approach to design minicells for mass customisation manufacturing

Designing and deploying a manufacturing system that has the flexibility to deliver customised product at low cost and short turnaround times is one of the main challenges that must be overcome by potential mass customisers. Configuring the system as a collection of modules, by creating minicells that are dedicated to option families, which can be recombined as necessary is one approach to achieve this flexibility. This paper presents a genetic algorithm-based approach to design a minicell configuration for mass customisation. The method is illustrated using a numerical example and results are compared with those from traditional manufacturing cells. The findings are promising and show potential for further improvement to achieve higher flexibility and shorter delivery times for dynamic demand environments as seen in mass customisation.
Solid state NMR studies of photoinduced polarization in photosynthetic reaction centers: mechanism and simulations.

We simulate Photo-Chemically Induced Dynamic Nuclear Polarization in the 15N-solid-state NMR of 15N-labeled photosynthetic reaction centers using a Radical Pair Mechanism (RPM). According to the experimental data, the directly polarized nuclei include all eight nitrogens in the ground state of the bacteriochlorophyll special pair (P), and N-II in the bacteriopheophytin acceptor (H) [M.G. Zysmilich, A.E. McDermott, J. Am. Chem. Soc., 116 (1994) 8362–8363.] [M.G. Zysmilich, A. McDermott, J. Am. Chem. Soc., 118 (1996) 5867–5873.] [M.G. Zysmilich, A. McDermott, Proc. Natl. Acad. Sci. U.S.A., 93 (1996) 6857–6860.]; other signals are polarized in nonspecifically labeled samples, but the polarization apparently results from magnetization exchange with neighboring polarized nitrogens, and these are not treated in this work. Two quantitative models for the polarization associated with the RPM are presented and are used to test the validity of the proposal that this mechanism is cooperative in the reaction centers. The kinetic models can treat the steady state polarizations as well as the approach to steady state, and in principle could be expanded to include anisotropic effects, or pulse-probe experiments. Several features of the detailed simulations of the steady-state amplitudes and the kinetics of the approach to steady-state are compared with our data, including the signs and approximate absolute magnitudes of the polarization on the nitrogen nuclei in P and HL, and the changes in the relative amplitudes with the change in the lifetime of the molecular triplet, photoaccumulation time, nuclear relaxation rate and illumination intensity. The simulations demonstrate that the polarization intensities are in qualitative agreement with those predicted for the RPM, including the curious observation of strong polarization on the pheophytin acceptor for certain experimental conditions. However, this agreement requires efficient relaxation of the nitrogens on HL by 3P, due to a fortuitous low nanosecond value for the spin-lattice relaxation for the electrons in the molecular triplet of the donor, T1e of 3P. Whether this fortuitous match is valid is unproven.
An Empirical Examination of a Modified Matrix Sampling Procedure as an Evaluation Tool for Grades 7 to 12 in a Midwestern School District.

Multiple matrix sampling is a data collection technique that ensures accuracy and efficiency in group performance. It has been widely used in large-scale curriculum evaluation since the 1980s. However, the design does not always fully embrace the dynamics of local evaluation demands. The purpose of this study is to introduce a modified matrix sampling design to meet the specific need of a local school district to collect evaluation data. The most salient difference of the modified matrix sampling method in the present study lay in the incorporation of core items, while dividing the remainder of the items in the entire item pool into two instruments. The results from empirical examination of the modified matrix sampling design indicated that the approach is efficient at no extra cost for accuracy.
Effects of secondary forces on the ligand binding and conformational state of antifluorescein monoclonal antibody 9-40.

Biochemical interactions that occur external to the antibody active site have been termed secondary forces. Secondary forces are supplemental to interactions within the antibody active site (i.e., primary interactions) and can affect ligand binding efficiency as well as variable domain conformation. The antifluorescein antibody system has been determined to be a superior method for delineating primary from secondary interactive components due to the active site-filling properties of the fluorescyl ligand. To date, all studies of secondary forces within the context of the antifluorescein system have been with the high-affinity monoclonal antibody 4-4-20 (mAb 4-4-20) (Mummert & Voss, 1995, 1996, 1997). In order to determine the generality of experimental observations and proposed models, we investigated the effects of secondary forces on the antifluorescein mAb 9-40. In addition to assessing the results of former studies, mAb 9-40 possesses properties unique from those of mAb 4-4-20, namely, a decreased affinity for fluorescein and increased conformational dynamics relative to mAb 4-4-20 (Carrero & Voss, 1996). Results of fluorescein and intrinsic mAb 9-40 tryptophan quenching as well as differential scanning calorimetric (DSC) studies indicated that secondary forces modulated the conformational (metatypic) state in accordance with previous investigations with mAb 4-4-20. Unlike mAb 4-4-20, mAb 9-40 did not exhibit altered ligand binding efficiency due to the inclusion of secondary interactive components. Models were developed that proposed that the increased malleability of mAb 9-40 variable domains could account for functional differences in properties between mAb 9-40 and mAb 4-4-20.
THE BLADDER ANGIOTENSIN SYSTEM IN FEMALE RATS: PONSE TO INFUSIONS OF ANGIOTENSIN I AND THE ANGIOTENSIN CONVERTING ENZYME INHIBITOR ENALAPRILAT

Purpose: A local renin angiotensin (ANG) system has been identified in the bladder. To our knowledge little is known about this system. To define further the physiology of this system we performed this study.Materials and Methods: The circulating and bladder tissue concentrations of ANG I and ANG II were examined in anesthetized Sprague-Dawley female rats in estrus, diestrus or pregnancy. Each was given an intravenous bolus infusion of ANG I, the ANG converting enzyme inhibitor enalaprilat or saline.Results: The mean concentrations of ANG I and ANG II were markedly higher in bladder tissue than in whole blood at the highest levels in pregnancy. The concentration of ANG I and ANG II increased significantly in the bladder tissue and circulation after the ANG I infusion in estrus and diestrus. In pregnancy only circulatory ANG I increased, while circulatory ANG II, tissue ANG I and ANG II remained unchanged. Enalaprilat infusion was associated with an increased concentration of whole blood ANG I in all group...
Management of Alcoholic Cirrhosis of the Liver

Patients with liver disease require skilled, complex management of the inevitable complications associated with hepatic dysfunction. Portal hypertension, a major consequence of cirrhosis of the liver, causes ascites and esophageal variceal hemorrhages. Many clinical and surgical treatment options are available to manage these complications; however, they often produce only temporary symptom control and may beget further morbidity. This article focuses on the etiology, complications, and treatment of alcoholic cirrhosis. Perioperative nursing care of patients with alcoholic cirrhosis is based on an understanding of normal hepatic functions and the systemic effects of cirrhosis.
An Approach to Rationalize Partitioning Sample Size into Individual Regions in a Multiregional Trial

The desire to make valuable medicines available to patients globally at approximately the same time has led many pharmaceutical sponsors to consider conducting multiregional trials. In this article, we propose an approach to rationalize partitioning the total sample size among the constituent regions in a confirmatory multiregional trial. Our approach is to find the minimal sample size for the smallest region so that there is a high probability of observing a consistent trend in the estimated treatment effect across regions if the treatment effect is positive and uniform across regions. We investigate this probability in two ways, namely, unconditional and conditional on the overall treatment effect being statistically significant. In the case of three regions, the proportion of patients from the smallest region could be as low as 15% to have an 80% probability that the observed treatment effects are consistent across the three regions, conditional on concluding a statistically significant overall treatment effect.
Expression of integrin α2β1 in axons and receptive endings of neurons in rat, hairy skin

Abstract Integrin α2β1 has been considered as a mechano-chemical transducer in endothelial and muscle cells. However, little data is available to show whether integrins play a role in the process of mechanical transduction in peripheral mechanosensory neurons. Using immunohistochemistry, we demonstrate that cutaneous neurons express the extracellular matrix (ECM) receptor integrin α2β1. Specifically, we show that integrins α2 and β1 are co-localized with peripherin in the receptive endings of cutaneous neurons in rat, hairy skin. Integrin immunofluorescence was minimal along the axons of large diameter neurons. These results, together with findings by other investigators, provide evidence suggesting that integrin α2β1 may be a linking agent between mechanical stress in the ECM and modulation of the neuronal response of mechanically sensitive neurons.
Formation of Banded Textures in Liquid Crystalline Polymers with Extended Curvature Elasticity

A new theoretical approach which describes the formation of banded textures in liquid crystalline polymers is introduced. The approach incorporates the concept of extended curvature elastic free energy in describing the response of the director field to strain recovery. Physically, this corresponds to accounting for an additional energetic penalty for deformation of the director field over very short distances, resulting from the natural persistence of orientation in rigid polymer chains. Both analytical and numerical results indicate that periodic patterns are spontaneously generated whenever the magnitude of the second-order gradient terms exceeds a critical value. Numerical investigations of two-dimensional systems reveal that elastic anisotropy has a significant effect on the aspect ratio and orientation of the patterns formed.
Mapping at glomerular resolution: fMRI of rat olfactory bulb.

The rat olfactory bulb contains approximately 2000 functional units called glomeruli which are used to recognize specific characteristics of odorants. Activity localization of individual glomerulae ( approximately 0.002 microL) has important consequences for understanding mechanisms in olfactory information encoding. High-resolution functional MRI (fMRI) data from the rat olfactory bulb are presented using the blood oxygenation level dependent (BOLD) method at 7 T. Either individual or clusters of fMRI voxels suggestive of activity in the olfactory nerve and glomerular layers were reproducibly detected with repeated 2-min exposures of iso-amyl acetate at spatial resolution of 0.001-0.003 microL. The importance of glomerular clustering for olfaction and the implications of BOLD mapping with even higher spatial resolution (i.e., <<0.001 microL voxels) are discussed. High-resolution in vivo mapping of the rat olfactory bulb with fMRI at high magnetic field promises to provide novel data for understanding olfaction.
Stray free switched capacitor loop biquad that realizes different generic transfer functions

Abstract A switched capacitor biquadratic filter circuit capable of realizing stable biquadratic Z-domain transfer functions is introduced. The biquad is parasitic free and uses two op.amps. The circuits are arranged in such a way that similarly switched capacitors share a common switch. Design examples are given to illustrate the theory.
Regional distribution of microsomal drug and steroid metabolism in the guinea pig adrenal cortex.

Abstract The regional distribution of steroid and drug metabolism was studied in intact cells and microsomal fractions obtained from the chromatically distinct inner (zona reticularis) and outer (zona fasciculata plus zona glomerulosa) zones of the guinea pig adrenal cortex. Cells isolated from the outer cortical zone produced far more cortisol than cells from the inner zone and cortisol production was stimulated by adrenocorticotropic hormone only in cells from the outer zone. Among the factors which may contribute to the greater cortisol production by the outer zone are a higher rate of 17α-hydroxylation and ratio of 17α- to 21-hydroxylase activities in that zone, both of which favor cortisol synthesis. In contrast, steroid 21-hydroxylase activity was far greater than 17α-hydroxylase activity in microsomes obtained from the inner zone of the adrenal cortex. Microsomal metabolism of various xenobiotics such as benzo (a) pyrene and ethylmorphine proceeded far more rapidly in the inner than outer cortical zone. The zonal differences in metabolism appeared to result in part from differences in the ability of xenobiotics to interact with microsomal cytochromes P-450 in the two zones. The results indicate that the inner zone has a minor role in cortisol production by the adrenal cortex, but its involvement in the production of other steroids cannot be excluded. In contrast, the inner zone appears to have the major role in the metabolism of at least some xenobiotics which may account for its greater vulnerability to the toxic effects of chemicals requiring metabolic activation.
A multiscintigraphic approach to imaging of lymphedema and other causes of the congenitally enlarged extremity

Nuclear imaging in the definition of the components of the congenitally enlarged extremity is important in the design of a successful therapeutic regimen. In our series of 32 patients evaluated for primary lymphedema, 85% were determined to have abnormalities that were not purely lymphatic in origin. The multiscintigraphic approach defines the components of the lymphatic and vascular systems with the use of technetium-99m [99mTc] antimony sulfide colloid (99mTc Sb2S3) for lymphatic, 99mTc diethylenetriamine pentacetic acid (DTPA) for capillary-interstitial, and 99mTc-tagged red blood cells for venous systems.
Cellular Mechanism of Action of Botulinum Neurotoxin

AbstractBotulinum toxin (Botx) is the most potent toxin known. It is found as seven distinct serotypes (A-G). The toxin has a M.W. of approximately 150,000, but is usually found as two disulfide-linked chains, one of 100,000 and the other 50,000. The toxin acts presynaptically to block the release of acetylcholine and thereby induce paralysis. It is suggested that the toxin might act by the same general mechanism as other bacterial toxins, i.e. after binding to a cell surface receptor, it enters the cell and expresses some type of enzymatic action ultimately leading to the block of neurotransmitter release.
The Relationship of Demographic Factors, Locus of Control and Self-Efficacy to Successful Nursing Home Adjustment

This study investigated demographic and psychological predictors of 58 older adults' successful adjustment to a nursing home. Predictors included demographic variables, locus of control, and self-efficacy beliefs. Successful adjustment was defined by activity level and by positive and negative affect. Findings suggest that demographic variables were not effective predictors of successful adjustment. Perceived self-efficacy accounted for more of the unique variance in adjustment than locus of control. Results are discussed in the context of improving resident adjustment to nursing home environments.
The distribution of radioiodine in a patient with metastatic adenocarcinoma of the thyroid; report of a case.

THE following case is reported because it throws some light upon the distribution of radioiodine in tissues other than the thyroid as well as upon the question of the accumulation of radioiodine by primary and metastatic thyroid neoplasms. REPORT OF CASE The patient was a man aged 55 years, who registered at the Mayo Clinic on May 14, 1948. Several years prior to admission a nodular enlargement of the thyroid had occurred and in February, 1947, subtotal thyroidectomy had been performed. The microscopic examination of the thyroid was reported to show adenocarcinoma, grade 3 (Broders' method). Subsequently, the patient had received two intensive courses of roentgen therapy, after which he gained weight and appeared to be well. A visible swelling of the scalp had appeared about six months before admission. Hoentgenograms of the skull were stated to have disclosed a metastatic lesion in the left parietal bone. The swelling subsided upon roentgen treatment. One month before admission the thyroid region again h...
Uncertainty of Estimates of Cancer Risks Derived by Extrapolation from High to Low Doses and from Animals to Humans

The uncertainties associated with extrapolating model-based cancer risks from high to low doses and animal-based cancer risks to humans are examined. It is argued that low-dose linear extrapolation based on statistical confidence limits calculated from animal data is designed to account for data uncertainty, model-selection uncertainty, and model-fitting instability. The intent is to err on the side of safety, that is, overstating rather than understating the true risk. The tendency toward conservatism in predicting human cancer risks from animal data based on linear extrapolation is confirmed by a real-data analysis of the various sources of uncertainty involved in extrapolating from animals to humans. Along with the tendency toward conservatism, a high degree of overall uncertainty in the interspecies extrapolation process is demonstrated. It is concluded that human cancer risk estimates based on animal data may underestimate the true risk by a factor of 10 or may overestimate that risk by a factor of 1...
Conventions of Courtship: Gender and Race Differences in the Significance of Dating Rituals

Dating rituals include dating—courtship methods that are regularly enacted. This study explores gender and race differences in the relative importance placed on certain symbolic activities previously identified by the dating literature as constituting such rituals. Using information collected from a racially diverse sample of college students (N = 680), it is found that some traditional gender differences persist, but that these are also cross-cut by racial contrasts. Men, overall, place more emphasis on gifting, as well as sexual activity. Gender differences, however, are significantly greater among African Americans as compared with Whites in the sample studied. African American respondents are also significantly more likely than White respondents to associate meeting the family with a more serious dating relationship. The findings highlight the need for greater efforts to uncover and account for racial differences in dating, relationships, and courtship.