cssi/SciSciGPT-SciSciNet huggingface dataset:
In vitro effects of aflatoxin B1 on the uptake of14C-orotic acid into kidney, liver and muscle tissue of the Mongolian Gerbil,Meriones unguiculatus

Aflatoxins are a mixture of highly toxic metabolites produced by certain strains of the mold Aspergillu8 ~avu~ a contaminant of groundnuts and other grains. The chemical structures for these potent hepatotoxic and hepatocarcinogenic agents have been studied extensively and aflatoxin B I (AFB I) has been found to be the most abundant and toxic metabol~te (B~TLER 1966). A major area of study involving the aflatoxins has dealt with their mechanism of action. Often severe inhibition of protein synthesis by the cell can be measured by uptake and incorporation of various labeled precursors of protein and nucleic acids (SMITH 1963, CLIFFORD & REES 1966, 1967). One investigator reported inhibition Of nuclear and nucl~olar RNA synthesis (30% and 85%, respectively) as measured by 14C-orotic acid incorporation in Other work with rats showed rat livers (LEFARGE et al. 1966). i~ no inhibition of incorporation of C-orotic acid in in vivo studies of the nucleotide pool, but immediate inhibition in in vitro studies. However, the authors did find inhibition of nucleotide precursors into nuclear RNA and postulated inhibition of RNA polymerase as a possible explanation (CLIFFORD & REES 1967). Later work subsequently explored this hypothesis corroborating it for RNA polymerase and implicating metabolites of AFB I as the active intermediate forms responsible for the inhibitmon (AKINRIMIST et al. 1974). A metabolite of AFB I was also suggested as the actual inhibitor of RNA synthesis in another work where the incorporation of RNA precursors, 14C-orotic acid and 3H-orotic acid, was markedly inhibited by low levels of AFH I and AFGI, but not AFB 2 and AFG 2 (MCINTOSH et al. 1976). Most of the literature involving measurement of uptake and incorporation of precursors has dealt m~inly with the effects on rats and few recent studies have used 14C-orotic acid. It was the purpose of this study to determine the effects of AFB_ on the uptake of 14C-orotic acid into kidney, liver and muscle tissue of the Mongolian gerbil, Meriones unguicula~s. This animal appears to be less sensitive to the toxin than the rat (GODY & NEAL 1976, LLEWELLYN & THOMEN 1978).
Coordinate repression of regulators of embryonic identity by PICKLE during germination in Arabidopsis

In angiosperms, germination represents an important developmental transition during which embryonic identity is repressed and vegetative identity emerges. PICKLE (PKL) encodes a CHD3-chromatin-remodeling factor necessary for the repression of expression of LEAFY COTYLEDON1 (LEC1), a central regulator of embryogenesis. A candidate gene approach and microarray analysis identified nine additional genes that exhibit PKL-dependent repression of expression during germination. Transcripts for all three LEAFY COTYLEDON genes, LEC1, LEC2, and FUS3, exhibit PKL-dependent repression, and all three transcripts are elevated more than 100-fold in pkl primary roots that inappropriately express embryonic traits (pickle roots). Three other genes that exhibit PKL-dependent regulation have expression patterns correlated with zygotic or somatic embryogenesis, and one gene encodes a putative Lin-11, Isl-1, MEC-3 (LIM) domain transcriptional regulator that is preferentially expressed in siliques. Genes that exhibit PKL-dependent repression during germination are not necessarily regulated by PKL at other points in development. Our data suggest that PKL selectively regulates a suite of genes during germination to repress embryonic identity. In particular, we propose that PKL acts as a master regulator of the LEAFY COTYLEDON genes, and that joint derepression of these genes is likely to contribute substantially to expression of embryonic identity in pkl seedlings.
Metastasis of Ewing's sarcoma to the choroid.

A patient had Ewing's sarcoma of the rib which metastasized to the choroid. Clinically, he showed a solid retinal detachment and recurrent episodes of anterior nongranulomatous uveitis. The uveitis responded to steroid therapy. While metastasis of Ewing's tumor to the orbit is well known, no previous cases of Ewing's tumor in the choroid were found, and the extreme rarity of intraocular tumor metastasis in childhood is discussed.
The measurement of visual attention in infants: a comparison of two methodologies.

Abstract Twenty-four infants were tested at 8 and 12 weeks of age—12 at each age—to determine fixation times to three checkerboard patterns of equal area, a 2 × 2, 8 × 8, and 24 × 24. Each infant was tested twice, once with a single stimulus method of presentation and once with a paired-comparisons. Both methods were similar in depicting age and sex differences. The older infants looked longer at the more complex patterns while the female infants fixated complex patterns longer, relative to simpler patterns, than than did the males. However, the paired-comparisons method was superior in distinguishing between what McCall (1970) has called “blank looking” from meaningful perceptual-cognitive interaction with a stimulus. The data were interpreted as showing that because females are more able to process information from static stimuli, as suggested by McCall, they are ahead of their male age peers in their perceptual-cognitive development within this age range.
Managed care and the competitive market in health care. What they can and cannot do.

THE STRENGTHENING of competitive market forces in recent years deserves some of the credit for the recent marked deceleration in the annual increases in national health care expenditures. But several informed analysts believe that the medical insurance premium cycle is once again turning up, which would be a prelude to higher total expenditures. 1 The recent moderation in annual cost increases reflected, in the first instance, the price-focused efforts of large corporate enterprises to moderate their health care benefit costs; the increasing surpluses in hospital beds and underemployed specialists that enabled the rapidly growing managed care companies to negotiate substantial discounts with key providers, physicians, and hospitals; the enthusiasm of the booming stock market to finance the expansion of the rapidly growing managed care sector; and the increasing preference of the sick elderly to be treated at home rather than in nursing homes, which has fueled a large expansion in
Pentamethyldisilylmethyl and related complexes of iron involving skeletal rearrangements, FeCSiSi → FeSiCSi

Abstract For the new complex Me 3 SiMe 2 SiCH 2 Fe(CO) 2 Cp the metalcarbon bond undergoes normal insertion reactions;however, under certain conditions the SiSiCFe framework rearranges to the siliconiron bonded system SiC SiFe.
Platelet alpha2-adrenergic receptor binding sites in major depressive disorder and borderline personality disorder

Platelet alpha 2-adrenergic receptor binding sites were measured in a group of patients with major depressive disorder (MDD) (n = 23) and in normal controls (n = 25). When all depressed subjects were compared to controls, there were no differences in either Kd (affinity of the ligand) or total binding site (number/platelet), although a significant change in the ratio of high to low affinity states was observed in the depressed group. When the depressed patients were subdivided into those with and without a co-occurring borderline personality disorder (BPD), the BPD group had significantly fewer alpha 2 high affinity binding sites, while the group with depression alone had significantly more binding sites (both low and high affinity) than the control group. The results support the concept that assessment of comorbid diagnoses may be essential to biological studies of depression.
Intracranial arachnoid cysts in children. A comparison of the effects of fenestration and shunting

✓ The best operative intervention for children with arachnoid cysts remains the subject of controversy. Recent reports stress that craniotomy for cyst fenestration is associated with a low incidence of morbidity and mortality and may leave the child shunt-independent. The cases of 40 pediatric patients with arachnoid cysts treated between 1978 and 1989 are reported. Five children with mild symptoms and small cysts that remained stable on follow-up studies have not required surgical intervention. Of 15 patients with cysts initially treated by fenestration, 10 (67%) showed no clinical or radiographic improvement postoperatively and have undergone cyst-peritoneal (eight patients) or ventriculoperitoneal (VP) shunting (one patient), or revision of a VP shunt placed for hydrocephalus before cyst fenestration (one patient). Two other patients with existing VP shunts required no further procedures. Thus, only three (20%) of 15 patients initially treated by fenestration remain shunt-independent after a median fol...
Secondary doping in polyaniline

Abstract Phenomenologically, a primary dopant for a conducting polymer is a substance, a relatively small quantity of which drastically changes the electronic, optical, magnetic, and/or structural properties of the polymer and it is accompanied by a large increase in conductivity. De-doping results in a reversal of the newly-induced properties. Phenomenologically, a secondary dopant is an apparently “inert” substance which, when applied to a primary-doped polymer, induces still further changes in the above properties including a further increase in conductivity. It differs from a primary dopant, in that the newly-enhanced properties may persist even upon complete removal of the secondary dopant. The concept will be illustrated using polyaniline and its derivatives. It will be shown that the effects of secondary doping are based primarily on a change in molecualar conformation of the polyaniline from “compact coil” to “expanded coil” during the secondary doping process.
A metatheory for the development of a science of information

Information science would do well to develop more and better theories, for without adequate theoretical support, we may do a technically brillant job of solving the wrong problems. However, the interdisciplinary nature of what information science is becoming means we must use a metatheory to guide the development of these theories. Without metatheory we cannot compare or unify the theories. A major statement in such a metatheory is to claim that there are three levels that should be used for information theorizing: casual, macroscopic, and microscopic. Use of these levels, and of the rules they imply, simplifies the evaluation of existing theories by making clear when theories are comparable in a meaningful way and, when they are not comparable, by showing what type of transformations are necessary to make them comparable.
Osteoblast precursor cells are found in CD34+ cells from human bone marrow.

It is known that osteoblast precursor cells are found in the low-density mononuclear (LDMN) fraction of human bone marrow (BM) aspirates. The purpose of this study was to investigate whether CD34, a hematopoietic progenitor cell marker, is present on osteoblast progenitor cells. LDMN, CD34+, and CD34− cells were cultured under conditions that promote growth and differentiation of mineral-secreting osteoblasts in a limiting dilution manner. With LDMN cells, osteoblast progenitor cells were found at an average frequency of 1/36,000 cells. With CD34− cells, osteoblast progenitor frequency remained at an average of 1/33,000, similar to LDMN cells. With CD34+ selected cells, osteoblast progenitor frequency increased to an average of 1/5,000. This osteoblast progenitor frequency is maintained in sorted CD34+/CD38+ cells. The osteoblasts generated from CD34+ cells were morphologically normal, and expression of skeletal-specific alkaline phosphatase and osteonectin increased upon differentiation induced by dexamethasone (DEX) treatment. Ultrastructurally, these CD34+ cell-derived osteoblasts displayed osteoblast-specific features. Functionally, these CD34+ cell-derived osteoblasts differentiated with DEX treatment, increased the level of cyclic adenosine monophosphate in response to parathyroid hormone stimulation, increased the level of alkaline phosphatase activity, and increased mineral secretion. These results demonstrate that osteoblast progenitor cells are enriched in the CD34+ cell population from BM and that these progenitor cells can differentiate into functional osteoblasts in culture.
Evaluation of CCHP systems performance based on operational cost, primary energy consumption, and carbon dioxide emission by utilizing an optimal operation scheme

Abstract Optimization of combined cooling, heating, and power (CCHP) systems operation commonly focuses only on energy cost. Different algorithms have been developed to attain optimal utilization of CCHP units by minimizing the energy cost in CCHP systems operation. However, other outcomes resulting from CCHP operation such as primary energy consumption and emission of pollutants should also be considered during CCHP systems evaluation as one would expect these outcomes can be subject to regulation. This paper presents an optimization of the operation of CCHP systems for different climate conditions based on operational cost, primary energy consumption (PEC), and carbon dioxide emissions (CDE) using an optimal energy dispatch algorithm. The results for the selected cities demonstrate that in general there is not a common trend among the three optimization modes presented in this paper since optimizing one parameter may reduce or increase the other two parameters. The only cities that show reduction of PEC while also reducing the CDE are Columbus, MS; Minneapolis, MN; and Miami, FL. For these cities the operational cost always increases when compared to the reference case consisting of using a vapor/compression cycle for cooling and natural gas for heating. On the other hand, for San Francisco and Boston, CCHP systems increase the CDE. In general, if CCHP systems increase the cost of operation, as long as energy savings and reduction of emissions are guaranteed, the implementation of these systems should be considered.
The emergence, localization and maturation of neurotransmitter systems during development of the retina in Xenopus laevis. I. γ-aminobutyric acid

The high-affinity uptake, biosynthesis and release of GABA have been studied in the retina of Xenopus laevis. In the mature retina, [3H]-GABA is accumulated predominantly by horizontal cells. A second population of cells located in the inner nuclear layer (possibly a type of amacrine cell) also showed a specific GABA uptake. In addition, this retina contains significant activities of L-glutamic acid decarboxylase and also releases [3H]-GABA in response to increasing K+ concentrations in the medium. We have followed the appearance and maturation of these GABA-ergic properties during embryonic development of this retina. Our results indicate that these properties emerge in a precise temporal pattern during retinal differentiation: the specific neuronal uptake of GABA precedes GABA synthesis which is followed by K+-stimulated GABA release.
Distinct Subgroups of Former Foster Youth during Young Adulthood: Implications for Policy and Practice

Chapin Hall Issue Brief March 2010 http://www.chapinhall.org/ Mark E. Courtney, Chapin Hall, University of Chicago and Partners for Our Children, University of Washington Jennifer L. Hook, Partners...
The evolution of climate change impact studies on hydrology and water resources in California

Potential global climate change impacts on hydrology pose a threat to water resources systems throughout the world. The California water system is especially vulnerable to global warming due to its dependence on mountain snow accumulation and the snowmelt process. Since 1983, more than 60 studies have investigated climate change impacts on hydrology and water resources in California. These studies can be categorized in three major fields: (1) Studies of historical trends of streamflow and snowpack in order to determine if there is any evidence of climate change in the geophysical record; (2) Studies of potential future predicted effects of climate change on streamflow and; (3) Studies that use those predicted changes in natural runoff to determine their economic, ecologic, or institutional impacts. In this paper we review these studies with an emphasis on methodological procedures. We provide for each category of studies a summary of significant conclusions and potential areas for future work.
CORR insights: Reliability of Bucholz and Ogden classification for osteonecrosis secondary to developmental dysplasia of the hip.

This CORR Insights™ is a commentary on the article “Reliability of Bucholz and Ogden Classification for Osteonecrosis Secondary to Developmental Dysplasia of the Hip” by Roposch and colleagues available at DOI 10.1007/s11999-012-2534-x.
RNA shotgun metagenomic sequencing of northern California (USA) mosquitoes uncovers viruses, bacteria, and fungi

Mosquitoes, most often recognized for the microbial agents of disease they may carry, harbor diverse microbial communities that include viruses, bacteria, and fungi, collectively called the microbiota. The composition of the microbiota can directly and indirectly affect disease transmission through microbial interactions that could be revealed by its characterization in natural populations of mosquitoes. Furthermore, the use of shotgun metagenomic sequencing (SMS) approaches could allow the discovery of unknown members of the microbiota. In this study, we use RNA SMS to characterize the microbiota of seven individual mosquitoes (species include Culex pipiens, Culiseta incidens, and Ochlerotatus sierrensis) collected from a variety of habitats in California, USA. Sequencing was performed on the Illumina HiSeq platform and the resulting sequences were quality-checked and assembled into contigs using the A5 pipeline. Sequences related to single stranded RNA viruses of the Bunyaviridae and Rhabdoviridae were uncovered, along with an unclassified genus of double-stranded RNA viruses. Phylogenetic analysis finds that in all three cases, the closest relatives of the identified viral sequences are other mosquito-associated viruses, suggesting widespread host-group specificity among disparate viral taxa. Interestingly, we identified a Narnavirus of fungi, also reported elsewhere in mosquitoes, that potentially demonstrates a nested host-parasite association between virus, fungi, and mosquito. Sequences related to 8 bacterial families and 13 fungal families were found across the seven samples. Bacillus and Escherichia/Shigella were identified in all samples and Wolbachia was identified in all Cx. pipiens samples, while no single fungal genus was found in more than two samples. This study exemplifies the utility of RNA SMS in the characterization of the natural microbiota of mosquitoes and, in particular, the value of identifying all microbes associated with a specific host.
Hierarchical Bridging Between Ab Initio and Atomistic Level Computations: Sensitivity and Uncertainty Analysis for the Modified Embedded-Atom Method (MEAM) Potential (Part B)

In this paper, a sensitivity and general uncertainty analysis is performed related to the modified embedded-atom method (MEAM) potential calibration of pure aluminum for data garnered from lower length scale (ab initio) simulations. Input uncertainties were quantified from 95% normal distribution confidence intervals of the various calibrated MEAM potential parameters from Part A of this study. A perturbation method was used to quantify the MEAM sensitivities to input parameters. The input uncertainties and sensitivities were then combined in a general uncertainty propagation analysis method. The results of the sensitivity analysis show that all the MEAM parameters interdependently influence all MEAM model outputs to varying degrees, allowing for the definition of an ordered calibration procedure to target specific MEAM outputs. In relation to the generalized stacking fault energy (GSFE) curve, the coefficient of the embedding function related to the background electron density, asub, was the most influential parameter related to the first peak. The first peak of the GSFE curve is related to unstable dislocations, in effect dislocation nucleation, and the first trough is related to stable dislocations. This connection of tying asub to the dislocation nucleation and motion was not obvious before this study indicating the power of the sensitivity and uncertainty method that was employed.
Physical consequences of mass singularities

Abstract We argue that the perturbation expansion of massless field theories are uniquely and unambiguously defined for properly formed observables. In so doing, we generalize the Kinoshita-Lee-Nauenberg theorem to show that there are no observable “mass-shell anomalies”. Paradoxically, in realistic circumstances, massive electrons give rise to non-intuitive, enhanced effects, for example, an unexpected background to the search for right-handed charged currents at HERA.
Morphological transformation, autonomous proliferation and colony formation by chicken heart mesenchymal cells infected with avian sarcoma, erythroblastosis and myelocytomatosis viruses

Normal chicken heart mesenchymal cells at low density in monolayer culture in plasma-containing medium have a polygonal shape and are proliferatively quiescent. The combination of epidermal growth factor and insulin at hyperphysiological concentration, an insulin-like growth factor surrogate, causes these cells to assume a fusiform shape and to increase 40-fold in number during four days of incubation. These mitogenic hormones do not, however, induce normal chicken heart mesenchymal cells to form colonies in agarose suspension culture. Chicken heart mesenchymal cells infected with the Schmidt-Ruppin or Prague-A strains of Rous sarcoma virus or with the Fujinami or Y73 avian sarcoma viruses assume spindle and round shapes, increase 50-100 fold in number during four days of monolayer culture in the absence of mitogenic hormones and form macroscopic colonies during 3-4 days of agarose suspension culture. The autonomous (mitogenic hormone-independent) proliferation, in monolayer culture, of cells infected with temperature-sensitive transformation mutants of Rous sarcoma virus (tsNY68, tsNY72, tsLA24, tsLA29) is temperature-sensitive. Chicken heart mesenchymal cells infected with avian erythroblastosis virus assume spindle shapes and proliferate in monolayer culture at a rate comparable to that of sarcoma virus-infected cells but do not, however, form colonies in agarose suspension culture. Cells infected with the myelocytomatosis virus MC29 assume stellate shapes and increase 18-fold in number during four days of monolayer culture. Cells infected with the myelocytomatosis virus MH2 assume fusiform shapes and increase fourfold in number during four days of monolayer culture. Neither MC29 nor MH2 renders chicken heart mesenchymal cells capable of colony formation in agarose suspension culture. Infection with avian leukosis viruses (RAV-1, RAV-2, RPL-42) or with transformation-defective mutants of Rous sarcoma virus (tdNY105, 107, 109) does not affect the morphology or proliferative behavior of chicken heart mesenchymal cells. Monolayer culture of chicken heart mesenchymal cells in plasma-containing medium appears, therefore, to define the ability of onc genes of acute transforming avian retroviruses to induce autonomous (mitogenic hormone-independent) cell proliferation, the essential characteristic of neoplasia. The differences in transformed morphology and rates of autonomous proliferation between cells infected with different acute transforming retroviruses probably reflects differences in the modes of action of the transforming proteins encoded by the onc genes of the respective viruses.(ABSTRACT TRUNCATED AT 400 WORDS)
Ethanol fuel use in Brazil: air quality impacts

Brazil has a long history in the development of ethanol for use as a liquid fuel for vehicles. They have developed one of most efficient and economical systems for producing ethanol in the world. Brazil provides an example that many other countries would like to emulate. Using ethanol as a vehicle fuel has significant potential air quality impacts. This paper will review the available air quality and vehicle emissions data in Brazil, specifically focusing on vehicle related pollutants that may be impacted by the use of large quantities of ethanol in the fuel. The atmospheric concentrations of acetaldehyde (CH3CHO) and ethanol in Brazil are much higher than those in other areas of the world, while the concentrations of the single ring aromatic compounds and small carboxylic acids are more typical of observations elsewhere. Acetaldehyde and ethanol increase in vehicle emissions and nitrogen oxides (NOx) may increase when ethanol fuels are used. Both CH3CHO and NOx are very important contributors to photochemical air pollution and ozone (O3) formation. There are very significant O3 air quality problems in Brazil, most studied in the larger cities of Sao Paulo and Rio de Janeiro. These are issues that must be evaluated for other areas of the world that are considering the use of high ethanol content vehicle fuels.
A Criterion for Investing in Information

As the amount of money invoiced in a decision rises, so does the burden of making the decision. Thus, it is not surprising or rare that the question arises: should a study be instituted before the decision is made to lessen the risks involved? Of course, such a study will itself cost something depending on the cost of analyzing data, the number of people involved and the value of the information gathered. The decision maker is then confronted with two courses of action, to make a decision based on existing information or to institute a study program, i.e., to invest in information before making a decision. In this paper we develop a procedure by which the decision maker can choose between these alternatives.
Dynamic study of irradiated artificial skin using OCT

We report a novel application of optical coherence tomography (OCT), to monitor post-laser irradiation collagen injury in skin model. An artificial skin model (RAFT) which closely approximates human skin, was irradiated with a Perovskite laser (λ = 1341 nm). We investigated dynamic changes in a RAFT after laser irradiation through OCT and compared the results to those of histology. OCT images clearly delineated areas of post-irradiation collagen injury and allowed non-invasive monitoring of the wound healing process. Histology was correlated well with OCT images. OCT has advantages because it is non-invasive and allows serial monitoring at the same site over time. Our study showed that OCT may be a useful tool for determination of optimal parameters for non-ablative laser skin rejuvenation (NALSR) using different devices.
Hypothesis Testing for Various Familial Dependence Structures

This work compares various hypothesis testing procedures in the case of familial clustered data. Specifically, we use likelihood ratio and Wald's tests for maximum likelihood estimators, and Wald-type tests for moment and quasi-least squares estimators. Using simulations, we estimate significance levels for various hypotheses concerning the one-parent auto-regressive and two-parent equi-correlated dependence structures. We show that the likelihood ratio test performs best for certain simple hypotheses in the one-parent case, whereas the Wald-type test for the quasi-least squares procedure is optimal in the more complex two-parent case.
Timing of induction of ovulation in mares treated with Ovuplant or Chorulon

Abstract Reliable induction of timed ovulation is an important managerial tool in any horse-breeding operation. Not only does breeding close to ovulation increase pregnancy rates when using cooled, frozen, or poor-quality semen, but it also reduces the number of inseminations needed per cycle, resulting in a more efficient breeding program. To better predict ovulation time in the long estrus period of the mare, one could increase the frequency of transrectal palpations and ultrasounds and/or implement hormonal therapies to induce ovulations. However, previous studies have been unclear on the exact timing of ovulation of mares treated with human chorionic gonadotropin (Chorulon, Intervet Inc, Millsboro, DE) or deslorelin acetate (Ovuplant, Pharmacia and UpJohn Co, Kalamazoo, MI). This study was designed to determine the timing of ovulation after Ovuplant or Chorulon treatment in normal cycling mares presented to the veterinary clinic. In addition, the pregnancy rates were determined for mares bred when a single insemination, using frozen or chilled semen, was performed at a fixed time (36 hours) after Ovuplant or Chorulon treatment. Thirty-two mares were given a subcutaneous injection of 7.5 mg of prostaglandin F2α (Lutlyse, Ft Dodge Animal Health, Ft Dodge, IA) 5 days after the last ovulation and were examined every 48 hours until estrus was detected based on a dominant follicle and the presence of endometrial edema as determined by ultrasonographic examination. Group 1 (N = 12) was treated intravenously with 2,500 units of Chorulon, and group 2 (N = 20) was treated subcutaneously with Ovuplant as soon as mares were determined to be in estrus. Once treated all mares were examined by rectal palpation and ultrasound at 0, 12, 24, 28, 30, 32, 34, 36, 38, 40, 42, 44, 48, 60, 72, 84, 96, hours or until ovulation was detected. Ovulation rate in response to Chorulon was 83.3% at 48 hours, 91.6% at 72 hours, and 100% at 96 hours. All of the mares in the Ovuplant-treated group had ovulated by 48 hours. Chi-square analysis of the data showed a significant ( P
Release of insulin from pH-sensitive poly(ortho esters)

Abstract The principal objective of this work is the development of a bioerodible insulin delivery device that will release insulin in response to the concentration of external glucose where release of insulin is modulated by pH changes resulting from a glucose-glucose oxidase reaction. A major component of such a delivery system is a bioerodible polymer that can reversibly change erosion rates in response to very small changes in the surrounding pH. We have prepared such a polymer by incorporating tertiary amine groups into a linear poly(ortho ester). When insulin is incorporated into this polymer and thin disks subjected to well defined pH pulses, the polymer responds rapidly and reversibly to these pH pulses. Current efforts involve preparation of glucose sensitive devices by surrounding the insulin-containing polymer with a microporous hydrogel containing immobilized glucose oxidase. When glucose diffuses into the device, gluconic acid produced within the hydrogel will decrease the ambient pH thus triggering release of insulin. The hydrogel is microporous to permit rapid release of insulin from the polymer to the surrounding environment.
Studies of C4 and C10 methyl ester flames

Abstract The oxidation of three model biodiesel fuels, namely methyl butanoate (C5H10O2, CAS No. 623-42-7), methyl crotonate (C5H8O2, CAS No. 623-43-8), and methyl decanoate (C11H22O2, CAS No. 110-42-9) was investigated in laminar premixed and non-premixed flames. The experiments were conducted in the counterflow configuration at atmospheric pressure, for a wide range of equivalence or inert-dilution ratios, and elevated reactant temperatures. Laminar flame speeds and local extinction strain rates were determined by measuring the flow velocities using digital particle image velocimetry. The experimental data were compared against those derived for flames of n-alkanes of similar carbon number, in order to assess the effects of saturation, the length of carbon chain, and the presence of the ester group. Several recent chemical kinetic models were tested against the experimental data, and major differences were identified and assessed. The accuracy of the Lennard–Jones potential parameters assigned to the methyl esters in the transport databases of the different models was evaluated and new values were estimated. Insight was provided into the high-temperature kinetic pathways of methyl esters in flame environments. Additionally, the reduced sooting propensity of methyl ester flames compared to n-alkane flames was investigated computationally.
Drug Iatrogenesis and Clinical Pharmacy: The Mutual Fate of a Social Problem and a Professional Movement

The controversial question of how much disease is caused by medical intervention goes to the heart of a social movement within the profession of pharmacy. The fate of “clinical pharmacy” is tied to the ability of pharmacists to detect and correct errors in prescribed medications, a potential source of iatrogenic disease. The dilemma for pharmacists is that documentation of their clinical activities could increase the liability exposure of medical organizations and impugn the reputations of physicians as competent prescribers of drugs. A participant observation study reveals how problems of drug therapy and the work of clinical pharmacists are negotiated within hospital settings.
Anticoagulation in the Elderly

Oral anticoagulation has been shown to provide great benefit in preventing and treating thromboembolic disorders. The challenges of oral anticoagulation management in the elderly involve balancing the risks of bleeding versus the benefits of a life-saving treatment. Due to the complex nature of warfarin, therapy must be individualized with frequent monitoring, re-education, and adjustments based on concurrent illness and drug therapy. This review focuses on the use of warfarin, including indications, dosing recommendations, drug and dietary interactions, and reversal of anticoagulation. Methods to determine bleeding risks in this population and barriers that interfere with the prescribing of warfarin are discussed. Strategies to improve patient outcome and reduce adverse events are provided to assist clinicians in their decision-making skills. The potential advantages of anticoagulation clinics are summarized with regards to coordinating the care and minimizing the risks of anticoagulant therapy. The role...
Apparent deposition velocity and compensation point of ammonia inferred from gradient measurements above and through alfalfa

Abstract Understanding the cycling of ammonia between croplands and the atmosphere is of importance to agriculturalists and atmospheric scientists. Flux densities of gaseous ammonia (NH3), particulate ammonium (NH4+), and total ammoniacal nitrogen (AN) were measured using an aerodynamic method above an alfalfa (Medicago sativa, L.) canopy between April and July 1981 at a rural location in central New York State. In air not influenced by local sources, NH3 and NH4+ averaged 1.5 and 3.0 ppb, respectively, at 1 m above the crop. Ambient NH4+ varied consistently with synoptic air masses, being lowest (2.3 ppb) for NW and highest (6.4 ppb) for SW flows. Concentrations and gradients of both species were higher during periods of hay harvest. Gradients of NH3 were much steeper than those of NH4+ within the alfalfa canopy, but NH4+ contributed appreciably (36% on average) to above-canopy AN gradients. Alfalfa's NH3 compensation point was estimated by combining concentration and gradient data with transport resistances. Gaseous gradients indicated a compensation point of 2 ppb, lower than previously published estimates. Conversion of NH3 to NH4+ within the canopy air could have reduced NH3 gradients and caused a low estimate of the compensation point. Acidic aerosols, by keeping NH3 levels low, may compete with plants for NH3. Future studies of ammonia exchange should distinguish between NH3 and NH4+ if flux densities are to be related to ambient conditions. Total AN level is a poor predictor of soil-plant-atmosphere ammonia exchange since high AN was frequently associated with low NH3, and NH3 is more surface reactive than NH4+.
Application of generalized radial basis functions to the problem of object recognition

The neural network approach to computation is founded on the application of simple mechanisms, operating uniformly in massively parallel structures. In addition, the notion of `learning'' or `training'' plays a strong role; the hope is that, given sample solutions to a difficult problem, some general mechanism can construct a general rule which produces solutions. This paper describes an application of one variant on this paradigm, the theory of generalized radial basis functions (GRBF), also called HyperBF, to the problem of object recognition, which has often been regarded as a `symbolic'' domain, ill-suited to the application of neural networks. The authors begin with a brief reviewing of the view of learning which leads to the HyperBF paradigm, and continue by describing how the problem of recognizing views of a particular object may be cast into the neural network paradigm, and showing the application of HyperBF to the problem, with examples. Problems for further work are discussed. The HyperBF scheme for learning models emerges from function approximation theory (specifically, Tikhonov''s regularization theory). In its full generality, it includes a number of other function approximation schemes; it also has a simple representation as a form of computational network (albeit a slightly unusual form). A feature of particular interest is that the network is trained only on 2-D views of the objects to be recognized; no explicit 3-D models are ever constructed, nor are they ever required. A discussion of the plain radial-basis-functions method of approximation is followed by discussion of various generalizations.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Molekulare Bildgebung in der Magnetresonanztomographie und der Nuklearmedizin

Die Bestimmung genetischer und biochemischer Veranderungen erlaubt in zunehmendem Mase die eindeutige Charakterisierung und Klassifikation von Erkrankungen. Bisher ist hierzu in der Regel eine gezielte immunohistopathologische oder molekularbiologische In-vitro-Analyse nach Resektion oder Entnahme einer Biopsie erforderlich. In der experimentellen Forschung wie auch in der klinischen Anwendung sind bildgebende Verfahren wunschenswert, die eine nichtinvasive Detektion und ein wiederholt durchfuhrbares Monitoring gewahrleisten. Aus diesem Grunde ist die Entwicklung radiologischer Untersuchungsmethoden erforderlich, die uber die morphologischen und physiologischen Veranderungen hinaus eine Beurteilung der genetischen und biochemischen Vorgange ermoglichen. In diesem kurzen Ubersichtsartikel werden einige der zahlreiche aktuellen Forschungsprojekte zusammengefasst, die sich mit diesem Problem beschaftigen und inzwischen aussichtsreiche Techniken zur Verfugung stellen.
Developmentally transient expression of acetylcholinesterase within cortical pyramidal neurons of the rat brain

Abstract Using a histochemical method for the visualization of cholinesterase activity in neurons, we have observed developmentally transient expression of acetylcholinesterase (AChE) in cortical pyramidal neurons of the rat brain. Depending on the extent of the deposition of AChE reaction product, several types of cortical neurons could be visualized. We designated neurons with moderate-to-high staining intensity as AChEH and neurons with relatively lower staining intensity as AChEL. At birth (P0), very little AChE activity was found within cortical neurons. Between P1–P4, there was a gradual emergence of AChE-stained cortical neurons. At this stage, the majority of these neurons were of the AChEL type. At P5–P7 we observed an abrupt increase in AChE-stained cortical neurons. The number and the staining intensity of these neurons was at a peak at P8–P10. At this age range, the majority of these neurons were of the AChEH variety and displayed morphological characteristics of cortical pyramidal neurons. At P11–P15, there was an abrupt decrease in the number of AChEH neurons. After P15, the density and staining intensity of cortical AChE-positive (cholinergic) axons gradually increased. Nevertheless, AChEL pyramidal neurons were detected through these fibers up to P21. At P21, a dense plexus of AChE-positive axons was observed in all cortical areas while very little AChE reaction product was visible in pyramidal neurons, and this pattern continued into adult life. When the adult cortex was denervated from its AChE-positive axons by lesions of the nucleus basalis magnocellularis, many AChEL pyramidal neurons were uncovered. However, virtually no AChEH cortical pyramidal neurons were observed in such preparations. Developmentally transient AChE activity within these cortical pyramidal neurons might contribute to their maturation and establishment of synaptic connections.
Chemical vapor deposition of m-plane and c-plane InN nanowires on Si (100) substrate

Abstract In this paper, synthesis of indium nitride (InN) nanowires (NWs) by chemical vapor deposition (CVD) is studied. InN NWs were synthesized via a vapor–liquid–solid (VLS) growth mechanism using high purity indium foil and ammonia as the source materials, and nitrogen as carrier gas. The mixture of nonpolar m-plane oriented and polar c-plane oriented tapered InN NWs is observed grown on top of Si (100) substrate. Energy dispersive spectroscopy (EDS) showed that the tips of the NWs are primarily consisted of Au and the rest of the NWs are consisted of indium (In) and nitrogen (N). High resolution scanning electron microscopy (HRSEM) revealed that the InN NWs have both triangular and hexagonal cross sections. Transmission electron microscopy (TEM) diffraction pattern showed that the NWs are high quality single crystals having wurtzite crystal structure. High resolution transmission electron microscopy (HRTEM) showed the growth directions of the InN NWs with triangular cross section are along 〈10−10〉 nonpolar m-plane orientation and the InN NWs with hexagonal cross section are along 〈0001〉 polar c-plane orientation.
Identification of Types of Potentially Cariogenic Streptococci on Human Tooth Surfaces by the Fluorescent Antibody Technique

The frequency distribution of four potentially cariogenic streptococcal types, AHT, BHT, GS-5, and HHT, on seven specific maxillary and mandibular tooth surface segments of 27 male teenagers was investigated. BHT and HHT serotypes were widespread in the dentition of all subjects. AHT and GS-5 organisms were identified in 7 and 89% of the population studied, respectively.
The ultrastructural localization of acid phosphatase in zinc-deficient rat buccal epithelium

Abstract The ultrastructural localization of acid phosphatase was examined in the buccal epithelium from normal and zinc-deficient rats. The most obvious feature of the zinc-deficient tissue was the intercellular distribution of reaction product in the prickle cell layers. Within the prickle cells, acid phosphatase was present in conspicuous Golgi systems. This appearance is very similar to that described in tumours after treatment with various membrane-labilising agents. As zinc has been shown to have a stabilizing effect on cell membranes, it is suggested that these results may reflect an increased fragility of lysosomal and plasma membranes in the zinc-deficient epithelium.
Isotope effects in aqueous systems. VI. partial molal free energies in NaCl−H2O−D2O by freezing-point measurements. The heat of fusion of D2O

The freezing-point depressions of solutions of NaCl in normal and heavy water have been measured between 0.01 and 2m. Extrapolation of the isotope effect data to infinite dilution yields a new value for the heat of fusion of D2O at its melting point (−1507±3 cal-mole−1). The freezing-point data were employed to obtain osmotic coefficients at the feezing points of the solutions, which were corrected to rounded temperatures up to 40°C using the enthalpy data reported by Craft and Van Hook (previous paper). The data for H2O solution are in quantitative agreement with well-established results. Those for the D2O solvent establish the NaCl−D2O system as an isopiestic reference. In contrast to the statements of earlier authors, examination of the isotope-effect data reveals a\(\surd \overline m\) dependence within experimental error.
Planar thin film device for capillary electrophoresis.

Hollow tubular microfluidic channels were fabricated on quartz substrates using sacrificial layer, planar micromachining processes. The channels were created using a bottom-up fabrication technique, namely patterning a photoresist/aluminum sacrificial layer and depositing SiO2 over the substrate. The photoresist/aluminum layer was removed by etching first with HCl/HNO3, followed by etching in Nano-Strip, a more stable form of piranha (H2SO4/H2O2) stripper. Rapid separation of fluorescently labeled amino acids was performed on a device made with these channels. The fabrication process presented here provides unique control over channel composition and geometry. Future work should allow the fabrication of highly complex and precise devices with integrated analytical capabilities essential for the development of micro-total analysis systems.
Acid catalyzed rearrangement of β-ionone epoxide

Abstract Rearrangement of β-ionone epoxide with aqueous formic acid gave 1,2-dihydro-1,1,6-trimethylnaphthalen ( 2 ), 1-(1,2,2-trimethylcyclopent-1-yl)-2-penten-1,4-dione ( 3 ), 4-(5,5-dimethyl-2-acetyl-1-cyclopenten-1-yl)-2-butanone ( 5 ), 4-(1,3,3-trimethyl-2-cyclohexanon-1-yl)-3-buten-2-one ( 6 ), 4-(2,3,6-trimethylphenyl)-2-butanone ( 7 ) and 6,6-dimethyl-2,5-10-undecatrione ( 8 ). NMR assignments are made for each compound while a computer assisted analysis of the A 2 B 2 portion of 7 has been completed. Possible mechanistic pathways leading to these compounds are discussed.
Mutational Analysis of the Ethylene Receptor ETR1. Role of the Histidine Kinase Domain in Dominant Ethylene Insensitivity

The ethylene receptor family of Arabidopsis consists of five members, one of these being ETR1. The N-terminal half of ETR1 contains a hydrophobic domain responsible for ethylene binding and membrane localization. The C-terminal half of the polypeptide contains domains with homology to histidine (His) kinases and response regulators, signaling motifs originally identified in bacteria. The role of the His kinase domain in ethylene signaling was examined in planta. For this purpose, site-directed mutations were introduced into the full-length wild-type ETR1 gene and into etr1-1, a mutant allele that confers dominant ethylene insensitivity on plants. The mutant forms of the receptor were expressed in Arabidopsis and the transgenic plants characterized for their ethylene responses. A mutation that eliminated His kinase activity did not affect the ability of etr1-1 to confer ethylene insensitivity. A truncated version of etr1-1 that lacks the His kinase domain also conferred ethylene insensitivity. Possible mechanisms by which a truncated version of etr1-1 could exert dominance are discussed.
Goal-directed data integration for sonar picture compilation

Discusses a decision aid for managing data integration resources within a sonar picture compilation system. The system design is based on goal-directed data integration, which is the concept that data integration will be most effective if it is used to solve specific problems detected during the process of building the sonar picture. Under the goal-directed data integration framework, the process of sonar picture compilation is decomposed into a task hierarchy, with the successful completion of each task being considered to be a goal. A blackboard-based control structure is employed for prioritizing unsatisfied goals, planning sequences of data integration operations to satisfy each selected goal, and monitoring the execution of active plans. It is also demonstrated that the goal-directed representation provides a natural user interface for high-level operator control of data integration processing. Examples are presented for a passive sonar sensor and goals related to signal tracking tasks.