cssi/SciSciGPT-SciSciNet huggingface dataset:
ADDITIONAL STUDIES ON THE REGULATION OF CARBOHYDRATE-DEPENDENT ENZYMES IN THE JEJUNUM: CHANGES IN AMINO ACID POOLS, PROTEIN SYNTHESIS, AND THE EFFECT OF ACTINOMYCIN-D.

Adaptive changes in rat jejunal disaccharidase levels during carbohydrate starvation and carbohydrate feeding were studied in relation to protein synthesis, amino acid pools, and cell migration. When animals were fed a sucrose-rich, normal protein diet for 24 hr after being on a casein-rich, carbohydrate-free diet for 7 days, there was 50% reduction in the size of the total amino acid pool without a significant change in the proportions of individual amino acids in the pool. The specific radioactivity of the leucine pool increased whenever carbohydrate was added to the diet and protein intake reduced. The incorporation of radioactive precursors into homogenate and brush border proteins reflected the characteristics of the pools, and was thus higher during carbohydrate feeding when the pool size was smaller. The rate of cell migration was unaffected by diet. Disaccharidase activities fell during prolonged carbohydrate starvation. When animals were treated with actinomycin-D, ribonucleic acid synthesis measured 18 hr later was reduced 50%, and cell migration was arrested. The drug did not inhibit the sucrose-stimulated rise in homogenate sucrase activity, although it did abolish the expected increase in fructokinase activity. With actinomycin-D treatment, brush border sucrase activity did not parallel the increases seen in the homogenate, but rather fell markedly. The data demonstrate that dietary carbohydrate increases jejunal disaccharidase activity without elevations in the rate of protein synthesis and that the effect is also independent of ribonucleic acid synthesis and cell migration. By contrast, jejunal fructokinase activity is probably regulated at the level of transcription.
Noninvasive Monitoring in the Intensive Care Unit

After studying this chapter, you should be able to do the following: Know the different noninvasive monitoring techniques commonly used in the intensive care unit (ICU) setting. Know the advantages and limitations of the different noninvasive monitoring methods. Know the different technologies used in noninvasive monitoring. Correlate the findings observed during noninvasive monitoring with the patient’s changing physiology.
Characterization of HPV16 L1 loop domains in the formation of a type-specific, conformational epitope

Background Virus-like particles (VLPs) formed by the human papillomavirus (HPV) L1 capsid protein are currently being tested in clinical trials as prophylactic vaccines against genital warts and cervical cancer. The efficacy of these vaccines is critically dependent upon L1 type-specific conformational epitopes. To investigate the molecular determinants of the HPV16 L1 conformational epitope recognized by monoclonal antibody 16A, we utilized a domain-swapping approach to generate a series of L1 proteins composed of a canine oral papillomavirus (COPV) L1 backbone containing different regions of HPV16 L1.
Karyotypic Variation in Peromyscus Boylii (Rodentia: Cricetidae) from Mexico and Corresponding Taxonomic Implications

Schmidly, David J., and Gilbert L. Schroeter (Department of Wildlife and Fisheries Sciences and Department of Biology, Texas AM the principal differences are in the numbers of large and medium-sized biarmed autosomes which range from 2-10. Three chromosome races are recognizable in P. boylii; they are distributed parapatrically with respect to one another, and present evidence suggests that limited gene exchange occurs among them. The karyotype for topotypes of P. b. simulus from Nayarit, Mexico, is markedly different from all other forms of P. boylii, suggesting that this taxon is a distinct species. Chromosomal polymorphism of a non-Robertsonian type is seen in certain populations of P. boylii and may be the result of intergradation between the different chromosome races. The polymorphism involves a variable number of large biarmed autosomes with certain individuals in a population possessing a heteromorphic pair of autosomes. The karyotypes of P. oaxacensis and P. evides, both members of the boylii species group, are also described for the first time. [Karotypic variation; Peromyscus boylii.] The brush mouse, Peromyscus boylii, is distributed from Honduras northward to Oregon and Utah and eastward to Texas and New Mexico. This species has the largest geographic distribution of any in the boylii species group (Hooper, 1968) and is among the most common of Mexican mice. Currently, 15 subspecies are recognized with the greatest differentiation occurring on the highlands of Mexico. Chromosomal data from 80 specimens of P. boylii, mostly from the western and southwestern United States, revealed significant geographic variation in the karyotypes of these populations (Lee, Schmidly, and Huheey, 1972). However, only 14 specimens of boylii were examined from western Mexico (Durango, Sonora, and Michoacan) and none was examined from northeastern Mexico. Moreover, all populations sampled by Lee et al. (1972) were monomorphic with regard to their chromosomal complement; for that reason, they suggested that P. boylii is chromosomally conservative. However, since different populations of P. boylii display such karyotypic diversity, it might be expected that populations do exist which are chromosomally polymorphic. Our subsequent data reveal the existence of an extensive intrapopulational chromosomal polymorphism of a non-Robertsonian type in Mexican populations of P. boylii. The polymorphism has been found in populations of the subspecies P. b. levipes, P. b. beatae, and P. b. spicilegus from the Mexican states of Queretaro, Hidalgo, Veracruz, and Durango. Furthermore, certain populations of P. boylii from Queretaro, San Luis Potosi, Tamaulipas, and Nayarit possess karyotypes distinct from other populations of this species. Chromosomal variation in P. boylii is herein reviewed in light of certain taxonomic problems in this
HUMAN SLEEP IN 60 HZ MAGNETIC FIELDS

This report describes a double-blind, laboratory-based study of 24 healthy young men in which sufficient data were collected to examine the effects of intermittent versus continuous exposure to a 60 Hz, 28.3 microT magnetic field on multiple EEG measures of night sleep. Intermittent, but not continuous or sham exposure, was associated with less total sleep time, reduced sleep efficiency, increased time in Stage II sleep, and decreased REM sleep. Subjects exposed intermittently to the field also reported sleeping less well and feeling less rested in the morning than subjects in the other two groups. All observed effects were significant at P < or = .04 or less. The public health relevance of these results cannot be assessed as yet. Poor sleep quality, however, can have a detrimental influence on worker safety and performance, and has been associated with decrements in memory and learning processes. Additional research appears warranted.
Loop electrosurgical excision with a laparoscopic electrode and carbon dioxide laser vaporization: comparison of thermal injury characteristics in the rat uterine horn.

Abstract OBJECTIVE: Our purpose was to compare the thermal intraperitoneal injury in lesions resulting from a monopolar electrosurgical loop electrode designed for laparoscopic surgery with similar lesions fashioned by carbon dioxide laser vaporization. STUDY DESIGN: A randomized, observer-blinded comparison was made of histopathologically measured thermal injury in rat uterine horns. The primary outcome measure was the depth of necrotic debris and coagulative necrosis in the lesions created by the two methods. RESULTS: The depth of coagulative necrois was similar in the laser vaporization (0.118 ± 0.028 mm) and the loop excision groups (0.165 ± 0.167 mm). However, the average amount of necrotic debris was greater in the lasered lesions (0.053 ± 0.019 mm) compared with those made with the loop electorde (0.013 ± 0.011 mm). CONCLUSIONS: The depth of coagulative necrosis in rat uterine lesions fashioned with a loop electrode is similar to that of lesions created by carbon dioxide vaporization at power densities comparable with those usually achieved at laparoscopic surgery. There is a greater amount of necrotic debris in the lasered lesions. This suggest that electrosurgical loops designed for laparoscopic surgery may have promise for the cost-effective excision of intraperitoneal tissue.
Crystal structure and Tc of 1212-type cuprate (Tl,Cr)Sr2(Ca,Tl)Cu2O7

Abstract The crystal structure of the 1212-type cuprate (Tl,Cr)Sr 2 (Ca,Tl)Cu 2 O 7 was investigated using X-ray diffraction data and the Rietveld refinement technique. The refinement was performed using the tetragonal symmetry of space group P4/mmm. It was found that Cr atoms entered the partial Tl site while Tl atoms occupied the Ca site. (Tl,Cr) atomes displaced from the origin to (0.101(1), 0, 0), and O(3) shifted from (0.5, 0.5, 0) to (0.626(8), 0.5, 0). The refined lattice parameters were a = 3.8155(1) A and c = 12.0222(5) A . The refined composition was (Tl 0.812 Cr 0.100 Ca 0.088 )Sr 2 (Ca 0.842 Tl 0.158 )Cu 2 O 7 . Cr atoms were most likely to be at a high valence state. The enhancement of T c in the (Tl,Cr)-1212 cuprate is briefly discussed based on the structure parameters by comparison with the un-doped TlSr 2 CaCu 2 O 7 .
The Thermodynamics of Ion Exchange on Clay Minerals. A Preliminary Report on the System Montmorillonite-CS-SR1

A discussion is given of the advantages of the thermodynamic approach in the study of clay-ion-water systems. Generally valid equations for the description of the systems are given, and the relative significance of the osmotic terms is roughly assessed. The principal theoretical and experimental problem is the determination of the initial slopes of the exchange isotherms, and a formal method for handling this difficulty is described. Preliminary results on the system montmorillonite-cesium-strontium are used for illustrative purposes.
Epinephrine-induced cardiac arrhythmias in rabbits exposed to trichloroethylene: Potentiation by ethanol

Abstract The effect of ethanol on epinephrine-induced cardiac arrhythmias in rabbits exposed to trichloroethylene was examined. Rabbits were treated with saline (1 ml/kg) or ethanol (1 g/kg, iv or po, 30 min prior to exposure) and exposed for 1 hr to 6000 ppm trichloroethylene under dynamic airflow conditions. Epinephrine was infused until arrhythmias occurred after 7.5, 15, 30, 45, and 60 min of exposure and also 15 and 30 min postexposure. Serial blood samples were collected at these time points and analyzed for trichloroethylene and its two major metabolites, trichloroethanol and trichloroacetic acid. When ethanol was administered iv, additional blood samples collected at the same times were analyzed for ethanol. Rabbits treated with ethanol po developed epinephrine-induced cardiac arrhythmias sooner and at lower doses of epinephrine than control rabbits. Blood levels of trichloroethylene in these rabbits were significantly higher and trichloroacetic acid levels were significantly lower than in controls. Rabbits treated with ethanol iv also developed arrhythmias in response to epinephrine sooner and at lower doses than controls. More arrhythmias developed in rabbits treated with ethanol iv than po. Trichloroethylene blood levels of iv treated rabbits were significantly elevated above control level and trichloroethanol and trichloroacetic acid blood levels were significantly depressed. Trichloroethylene exposure significantly increased the blood half-life of ethanol. The data indicate that concomitant ethanol ingestion and trichloroethylene exposure could pose a significant health hazard.
Synthesis of cytoadhesive poly(methylmethacrylate) for applications in targeted drug delivery.

The objective of this work was to incorporate cytoadhesive properties into poly(methylmethacrylate) (PMMA) for potential applications in highly localized tissue-specific drug delivery. First, the PMMA was chemically modified by aminolysis to yield amine-terminated surfaces. X-ray photoelectron microscopy confirmed the presence of surface nitrogen entities, and the distribution of amine groups was found to be relatively uniform, as characterized by atomic force microscopy. The availability of these groups for attachment of biologically active molecules was characterized by fluorescence microscopy after immobilization of avidin-FITC. To render the PMMA cytoadhesive, avidin molecules were conjugated to the amine-terminated surfaces with a hydroxy-succinimide-catalyzed carbodiimide reagent and biotin-labeled lectins (tomato, which binds selectively to Caco-2 cells, and peanut, an unrelated lectin) subsequently were attached utilizing avidin-biotin chemistry. Cytoadhesive activity was evaluated by characterizing the interactions between microfabricated PMMA particles and Caco-2 monolayers. After 15-, 30-, 60-, and 120-min incubation periods, the tomato lectin-conjugated PMMA showed a two to sixfold increase in Caco-2 cell recognition over control particles. Furthermore, the stability of the cytoadhesive PMMA interactions appeared to be three to seven times greater than that of the control surfaces. These findings demonstrate the cytoadhesive properties of modified PMMA, making this novel bioactive polymer very promising for applications in targeted drug delivery. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 369–375, 2003
Growth of uniform ZnO nanoparticles by a microwave plasma process

Abstract ZnO nanoparticle coatings with a controlled size distribution have been grown on quartz substrates by a novel microwave plasma assisted spray (MPAS) technique. This study presents the analysis of structure, photoluminescence, and magnetic properties of particle coatings with two distinctly different mean particle sizes (400 nm and 200 nm). X-ray diffraction patterns show a typical wurtzite structure without any impurity phases for the nanoparticle coatings. SEM and TEM investigations have shown the grown nanoparticles to be spherical and well separated with a narrow size distribution. Nanoparticles are polycrystalline with smaller grain sizes associated with the smaller particle sizes. Photoluminescence (PL) spectra reveal the presence of oxygen vacancy related defects in the 400 nm nanoparticles, which become less pronounced in the 200 nm nanoparticles. The 400 nm nanoparticles are found to exhibit room-temperature ferromagnetism with a clear hysteretic behavior, while the 200 nm nanoparticles are diamagnetic even down to 10 K. These results suggest the oxygen vacancies were the cause for defect-induced ferromagnetism in the 400 nm nanoparticles.
A Comparison of Male and Female Business Managers

This article reports the results of a study of 108 males and 108 female business managers conducted in Autumn 1983 in the Los Angeles area. In addition to demographic data, subjects completed a personal values test and a decision style test. No significant differences were found between the two populations with the exception of salary, with the male managers earning 14 per cent more than the female managers. The gap in salaries between male and female managers appear to be about half of that between male and female workers, usually reported as being between 30 and 40 per cent.
Behavioral avoidance: Possible mechanism for explaining abundanc and distribution of trout species in a metal‐impacted river

Behavioral avoidance of metal mixtures by rainbow trout (Oncorhynchus mykiss) was determined in the laboratory under water quality conditions that simulated the upper Clark Fork River, Montana, USA. A metal mixture with a fixed ratio of observed ambient metal concentrations (12 {micro}g/L Cu:1.1 {micro}g/L Cd:3.2 {micro}g/L Pb:50 {micro}g/L Zn) was used to determine avoidance in a countercurrent avoidance chamber. Rainbow trout avoided all metal concentrations tested from 10 to 1,000% of the simulated ambient metal mixture. The behavioral response of rainbow trout to the metal mixture was more sensitive than the response of brown trout (Salmo trutta) previously reported from the same laboratory under the same experimental conditions. Additionally, rainbow trout that were acclimated to the simulated ambient metal mixture for 45 d preferred clean water and avoided higher metal concentrations. Therefore, laboratory experiments on the behavioral avoidance responses of rainbow trout, as well as previously reported experiments on brown trout, show that both species will avoid typical metal concentrations observed on the Clark Fork River. And the greater sensitivity of rainbow trout to the metal mixture may explain, in part, why rainbow trout populations appear to be more severely affected, compared to brown trout populations, in the upper Clarkmore » Fork River.« less
Parameter estimation for filtered discrete fractal signals

The problems of estimating the parameters of discrete fractals and filtered discrete fractals directions are considered. A maximum likelihood approach for estimating the parameters of pure fractals is presented. In particular, it is shown that the computation of the likelihood function does not require any matrix inversion as previously thought. For filtered fractals, an iterative procedure is proposed to estimate the parameters of the fractal signal and those of the shaping filter. The procedure has been shown to converge experimentally. >
The effect of governmental structure on special district expenditures

Recent research has analyzed the relationships between the governmental structure in an urban area, the degree of competition in the local public services market, and service provision efficiency (Martin and Wagner, 1978; Wagner and Weber, 1975; Mehay, 1981). With few exceptions, this literature has been content to focus on traditional units of local government municipalities, counties, and school districts and has ignored special districts.1 However, the changing pattern of local governmental organization indicates that this is a serious omission in the literature. Of all local jurisdictions, only special districts have increased significantly in numbers in recent years.2 The purpose of this paper is to provide a positive economic analysis of the direct impact of alternative organizational arrangements on resource allocation by special districts. The paper extends the analysis first undertaken by Wagner and Weber (1975) of the differences in the fiscal effects of multipurpose versus single purpose local governments. The hypotheses in this paper are deduced directly from the monopoly model of local government supply introduced by Wagner and Weber and applied to special districts operating under two alternate governmental arrangements. Specifically, the model predicts that the expenditures of special districts will differ depending on whether they are organized as self-governing, independent governmental units or as subordinate units of a larger, general purpose unit, such as a city or county. Section 2 examines some of the advantages and disadvantages that have been claimed for single purpose special districts and develops the basic hypothesis. Section 3 tests the hypothesis using data from two types of California special districts fire protection and recreation and parks -
Lubricant Bonding Effects on Thin Film Disk Tribology

The magnetic recording industry predominantly uses Zdol to lubricate the carbon overcoat of magnetic recording disks. Zdol comprises a perfluoropolyether chain terminated with hydroxyl end groups that are capable of reversibly bonding to the carbon overcoat. Contact start/stop (CSS) tests were done to investigate the effects of Zdol lubricant bonding, thickness, and relative humidity on durability. The durability improved with increasing thickness of fully bonded or mobile Zdol. The durability decreased with increasing initial bonded fraction and with decreasing relative humidity. The bonded fraction increased with time during the tests at elevated temperature and low relative humidity. Presented as a Society of Tribologists and Lubrication Engineers Paper at the ASME/STLE Tribology Conference in Seattle, Washington, October 1–4, 2000
Comparison of the clonal diversity of the B cell repertoires in adult mice that differ in the expression of cell surface IgD.

To determine whether the expression of surface IgD (sIgD) influences the extent of the expressed B cell repertoire, the clonal diversity of the B cell population in mice treated chronically with anti-IgD (delta) antibodies has been compared with the B cell repertoire observed in control animals, using the splenic focus limiting dilution B cell assay. The results show that the phosphorylcholine (PC)-specific B cell precursor frequency in anti-delta antibody-treated mice is increased when compared with that of control mice. Isotype and idiotype (T15) analyses of PC clonal products from anti-delta antibody-treated and control mice revealed no distributional differences. Analyses of the 2,4-dinitrophenyl (DNP)- and fluoresein isothiocyanate-specific B cell repertoires confirmed that the equal or increased precursor frequencies observed in anti-delta antibody-treated mice are not specific for the PC antigen. The increased precursor frequency of B cells from anti-delta antibody-treated mice was not the result of increased homing of B cells from anti-delta antibody-treated mice to recipient spleens, since B cells from control mice homed twice as well to recipient spleens as did B cells from anti-delta antibody-treated mice. Other studies demonstrated that (a) on average, antibody-secreting clones were generated more slowly when B cells from anti-delta antibody-treated mice were used as a source of precursors than B cells of control mice and (b) both sIg− spleen cells and sIg+ spleen cells from anti-delta antibody-treated mice generated a higher frequency of specific antibody-secreting clones than did the corresponding populations from control mice. These observations suggest that a population of sIgM+sIgD− B cells exists that resembles sIgD+ B cells rather than neonatal or xid B cells in its ability to generate responses to PC and suggests that the sIgM+ sIgD− B cells from anti-delta antibody-treated mice are more responsive than are sIgM+IgD+ B cells, regardless of antigenic specificity, to the stimuli provided in the splenic focus system. Finally, this study suggests that the expression of sIgD does not influence the extent of the expressed B cell repertoire.
Spin spectroscopy of dark excitons in CdSe quantum dots to 60 T

Polarization-resolved magnetophotoluminescence spectroscopy is used to study exciton spin states in 40--80 \AA{} diameter chemically synthesized CdSe quantum dots (QDs) at temperatures $T=1.2--50\mathrm{K}.$ The spin polarization is found not to saturate in magnetic fields to 60 T and time-resolved studies indicate a thermal population of exciton states. A simple model incorporating the angle-dependent Zeeman splitting and bright-dark level mixing in these randomly oriented quantum dots is constructed in quantitative agreement with the data. Fits using this model yield a dark exciton g factor of \ensuremath{\sim}0.9 at $T=1.45\mathrm{K},$ which is independent of QD diameter and exhibits a surprising increase with increasing temperature.
On the Phase Transition in Sym-trioxane

Abstract Polarized Raman Spectra of sym-trioxane single crystals have been recorded in the intra- and inter-molecular regions. Three phonons were observed at room temperature at 59.6, 64.3, and 84.8 cm−1 belonging to E symmetry. Temperature dependent Raman spectra were also recorded which showed the following important features: (a) polarization data could not be obtained below ca. 65 K; (b) the phonon at 85 cm−1 (300 K) splits into two modes at 63 K and the splitting grows continuously to 1.6 K, the lowest temperature reached in this study; (c) the phonons at 60 and 65 cm−1 (300 K) show a constar-slope linear increase in energy from 300 to 65 K at which point the slope changes consideramy; and (d) linewidths of these latter two modes evidence discontinuous changes at 63 K. Temperature dependence of the observed E(Tx, Ty ) phonon splitting follows approximately an equation of the form η(T)/η(1.6 K) = |(Tc - T)/Tc| 1/4. The phase transition is discussed in terms of various mechanisms and models which could...
Third ventricular pineal gland grafts in the gerbil: an electron microscopical and immunohistochemical investigation.

The superficial pineal gland was grafted into the third ventricle of adult mongolian gerbils. Donor pineal glands from both neonatal and 3–4 week old gerbils were able to survive for at least 6 months. The pinealocytes of the grafted superficial pineal glands maintained the morphology and the S-antigen immunoreactivity of the in situ pineal complex. Synaptic ribbons and spherules were present but rare. Unlike the in situ pinealocytes, glycogen accumulations were common in the graft pinealocytes. Site specific modulation of structure was indicated as the ventricular surface of the grafts became covered with cerebrospinal fluid (CSF)-contacting pinealocytes typical of those seen in the deep pineal. The CSF-contacting pinealocytes of the graft had numerous processes that extended along the ventricular surface of the graft. The blood vessels of the grafts had non-fenestrated endothelium and wide perivascular areas typical of those seen in the in situ pineal complex. Tyrosine hydroxylase-immunopositive nerve fibers were present in the grafted tissue indicating reinnervation of the graft. The source of the fibers was not determined. The nerve fibers were present both within the perivascular area and within the parenchyma where they were associated with pinealocytes. The results demonstrate that the cerebral ventricles are an ideal location for the survival of superficial pineal gland grafts. It is suggested that pineal grafts may be a means to further study pineal development and innervation. © 1992 Wiley-Liss, Inc.
Biofeedback and relaxation in the treatment of tension headaches: a reply to Belar.

In a recent critique Belar [Belar, C. D. (1979). J. Behav. Med.2: 215–220] questions the conclusion drawn by Silver and Blanchard [Silver, B. V., and Blanchard, E. B. (1978). J. Behav. Med.1: 217–239] regarding the comparative efficacy of EMG biofeedback and relaxation training in tension headache and suggests that continued research is needed. Data bearing on her criticisms and suggestions are reviewed. From the five studies addressing this point, we disagree with her major conclusion and contend that there is no consistent advantage of EMG biofeedback over relaxation training.
Diversity of insulin resistance in monkeys with normal glucose tolerance.

Insulin resistance has been proposed as a critical factor in the development of Type II diabetes, hypertension, dyslipidemia, and coronary artery disease. However, even in normal healthy individuals, a wide range of in vivo insulin action has been found. In the present study we sought to examine this heterogeneity in Insulin action in both normal and spontaneously obese nonhuman primates. Maximal insulin responsiveness as measured by a hyperinsulinemic euglycemic clamp, fasting plasma glucose, and insulin levels, β-cell insulin response to glucose, glucose tolerance, and adiposity were measured in 22 male rhesus monkeys. Results showed that lean animals (body fat ≤ 22%) had higher insulin-stimulated glucose uptake (M rate: 14.42±1.8 mg/kg FFM/min) compared to obese (8.08±0.8). The obese monkeys, with 23–49% body fat, had a wide range of M values (5.32-14.29 mg/kg FFM/min) which showed no relationship to degree of adiposity. In all monkeys, M values had a strong inverse correlation with fasting plasma insulin levels (r=-0.76; p<0.001), but not with fasting glucose or glucose disappearance rate. We conclude that neither degree of obesity above a critical threshold nor range of glucose tolerance is related to insulin resistance; however, in individuals with normal glucose tolerance an early reliable indicator of defective insulin action appears to be fasting insulin concentration. Longitudinal determination of basal insulin levels obtained under standardized conditions so as to minimize extraneous variability is likely to strengthen the ability to predict insulin resistance and possible later development of overt Type II diabetes.
Microfabricated atomic frequency references

Using microfabrication processes, we have been able to construct physics packages for vapour cell atomic frequency references 100× smaller than previously existing versions, with a corresponding reduction in power consumption. In addition, the devices offer the potential for wafer-level fabrication and assembly, which would substantially reduce manufacturing costs. It is anticipated that a complete frequency reference could be constructed based on these physics packages with a total volume below 1 cm3, a power dissipation near 30 mW and a fractional frequency instability below 10−11 over time periods from hours to days. Such a device would enable the use of atomically precise timing in applications that require battery operation and portability, such as hand-held global positioning system receivers and wireless communication systems.
Soda lakes, flamingoes, and scientific literacy: student explorations of the great rift valley

Abstract While current science policy documents suggest teaching and learning strategies that might lead to students becoming scientifically and technologically literate, little is known about how classroom teachers interpret the documents and how they actually incorporate the use of instructional technology in their teaching for scientific literacy. This paper evolved from a study designed to develop a richer understanding of how one elementary teacher, Ms Brook (pseudonym), utilized instructional technology to teach for scientific literacy. Using qualitative methodology, I examined the integration of instructional technology into the science curriculum, focusing on how the teacher used instructional technology to advance students' scientific literacy. In this paper, I first provide a theoretical background for scientific and technological literacy. I then describe the Flamingowatch electronic fieldtrip, its focus on scientific literacy, and students' reactions to the fieldtrip. Next, I describe the qual...
The Weight of the Hyphen: Freedom, Fusion and Responsibility Embodied by Young Muslim-American Women During a Time of Surveillance

This article reports on a qualitative investigation of 15 young Muslim-American women living in New York City, after 9/11 and in the midst of the Patriot Act. Participants completed surveys about identity, discrimination, and coping; drew “identity maps” to represent their multiple identities and alliances; and participated in focus groups on several college campuses in the New York metropolitan area. Focus groups were conducted to investigate collectively their sense of hyphenated identities, their experiences of surveillance and their responses to scrutiny in families, communities, on the streets and in the political public sphere. Implications for the theoretical and empirical study of immigrant youth “under siege” are developed, with a particular focus on the burdens and responsibilities embodied by daughters of the second generation of Muslim-Americans.
Tyrosine in Cheddar Cheese

Summary A study was made of the quantitative aspects of free tyrosine, the total tyrosine liberated, and the tyramine content of commercial and experimental Cheddar cheese. In well ripened commercial Cheddar cheese amounts of free tyrosine as high as 2,630 γ and as low as 348 γ, per gram of cheese, dry weight, were observed, and for experimental cheese similar values were obtained, but with a slightly greater range. The amount of free tyrosine is a variable whose concentration is dependent upon the difference in rates between proteolysis and decarboxylation. Total tyrosine liberated in Cheddar cheese, a function of the activity of proteolytic enzymes, was not subject to the degree of variability that was observed for free tyrosine. In well ripened commercial Cheddar cheese total tyrosine liberated ranged in value from 1,341 to 2,021γ per gram of cheese, dry weight. In experimental Cheddar cheese ripened for 176 days at 60 ° F. values as high as 3,583γ per gram were obtained. Addition of Streptococcus faecalis organisms to commercial lactic acid, starter did not materially increase the extent of total tyrosine liberation, but values were greater in experimental raw milk cheese than in their pasteurized milk counterparts. The total tyrosine liberated in Cheddar cheese during most of the ripening period appears to be the result of hydrolysis at the expense of the lower peptides, appreciable amounts being liberated even after soluble protein had attained its maximum value. Total tyrosine liberated was considered to be a more sensitive criterion of cheese ripening than are soluble protein values.
A reliable method for epicardial atrial and atrioventricular pacing: the loop electrode.

A new temporary atrial “loop” pacing electrode is presented with features of good pacing threshold and easy removal.
Involving academic scientists in conservation research: Perspectives of a plant ecologist

While academic scientists often wish to contribute to conservation efforts, differences between the academic and conservation arenas can sometimes frustrate their efforts. To increase awareness of both the opportunities and the potential pitfalls of such interactions, I examined and contrasted the perspectives of biologists in academia and in land management and conservation. Those responsible for protecting "sensitive" plants and vegetation possess a wealth of empirical evidence that could be used to test predictions of ecological and conservation biology theory. Real-life management issues offer perfect laboratories for research by academic scientists in population and community ecology, e.g., identifying factors important in regulating population size or assessing community responses to disturbance or to the introduction of a species. While such research combines basic questions with tangible application and (sometimes) financial support, it may also offer obstacles to participation by academic ecologists. Some of these are: difficulty of obtaining permits for experimentation on protected species; logistic and ethical questions of exper- imenting in preserves; and the sometimes small influence of science in decision-making in a multiple-use environment. Communication and collaboration between managers and sci- entists might be facilitated by state Heritage programs and recovery teams and by scientists taking advantage of existing agency outreach mechanisms.
Contemporary and historical classification of crop types in Arizona

This research compares three different classification algorithms for mapping crops in Pinal County, Arizona, using both present and historical image data. The study area lacked past crop maps, and farmers were dealing with the risk of evolution of resistance to insecticides in the whitefly, a global pest of cotton, fruits, and vegetables. The ability to create historical crop maps without concurrent training data is an invaluable tool for historical integrated pest management research. Comparison of maximum likelihood, object-oriented, and regression tree classifiers was done with Landsat Thematic Mapper imagery and high quality crop maps. Classification outputs for the three years in this research all achieved overall accuracies above the traditional benchmark of 85%. Comparison of the classification results shows that the classification and regression tree technique clearly outperformed the other classifiers. Using training data from one year and applying that data to another year for classification purposes demonstrated that overall accuracies from 71% to 83% are achievable, although accuracies were consistently greater than 85% for some crops.
Substance P-like immunoreactivity in rat forebrain leptomeninges and cerebral vessels originates from the trigeminal but not sympathetic ganglia

Substance P-like immunoreactivity (SPLI) is present in the pia mater, arachnoid and pial vessels (leptomeninges) of the rat. Unilateral electrolytic lesions of the trigeminal ganglion decreased levels of SPLI in leptomeninges on the lesioned side. Levels did not change following unilateral or bilateral superior cervical ganglionectomies or after i.c.v. injections of 6-hydroxydopamine, sufficient to deplete norepinephrine in pial arteries by more than 90%. SP levels did not decrease in leptomeninges or in blood vessels within the circle of Willis following treatment of adult or neonatal rats with capsaicin despite the fact that levels were reduced in the cornea and dorsal spinal cord in these same animals. These results suggest that not all substance P-containing sensory fibers are susceptible to the peptide-depleting effects of capsaicin.
The Role of Radiation Therapy in Small Cell Lung Cancer

Radiotherapy (RT) is fundamental to the care of patients diagnosed with small-cell lung cancer (SCLC). In the setting of limited stage disease (LS-SCLC), the addition of thoracic RT to chemotherapy (CHT) improves survival and local control, as demonstrated in decades-worth of randomized clinical trials and subsequent meta-analyses. In extensive stage disease (ES-SCLC), thoracic RT is invaluable in the palliation of chest symptoms but there are suggestions that its use in selected patients may potentially improve overall survival . Prophylactic cranial irradiation (PCI) also improves outcomes in SCLC. For LS-SCLC patients, it reduces brain metastases rates by half and improves overall survival with minimal impact on quality-of-life. Recently, favorable results for PCI with respect to survival and prevention of symptomatic brain disease have been observed for ES-SCLC patients with any response to CHT. Current phase III trials in SCLC RT include studies looking at the optimal dose and target for limited disease and the role of thoracic RT in extensive disease.
The Lack of Effect of Aerobic Exercise Training on Propranolol Pharmacokinetics in Young and Elderly Adults

The effects of exercise training on the pharmacokinetics of orally administered propranolol were studied in young and elderly healthy volunteers. Twenty-three young (30 ± 5 years of age) and 20 elderly (67 ± 5 years of age) adults were randomly assigned to endurance training (N = 12 young subjects, 10 elderly subjects) or nonexercising control (N = 11 young subjects, 10 elderly subjects) groups. Training consisted of treadmill walking, stairclimbing, or both three times per week for 40 minutes at 70-85% of maximal heart rate reserve for 16 weeks. Resting plasma propranolol concentrations after a single dose of 80 mg of oral propranolol were measured by high performance liquid chromatography with fluorescence detection, and estimated hepatic blood flow measured was measured using indocyanine green during supine rest. Aerobic training increased maximal oxygen uptake (VO 2 max) by 13% and 14% in the exercising young and elderly groups, respectively. There was no change in VO 2 max in either control group. Adjusted mean estimated hepatic blood flow after exercise corrected for body weight for the young subjects who did not exercise (15.6 mL/min/Kg) and those who did (18.2 mL/min/Kg) groups were of borderline significance. No statistical differences were detected in the experimental propranolol pharmacokinetic parameters (maximal concentration, time of maximal concentration, terminal half-life, area under the curve, and protein binding) or derived pharmacokinetic parameters (intrinsic clearance, bioavailability, clearance, and volume of distribution). These results provide evidence that changes in aerobic fitness do not produce corresponding changes in propranolol pharmacokinetics in young or elderly adults.
Life in science. Having a blast in Kenya.

![Figure][1] CREDIT: PETER HOEY/[PETERHOEY.COM][2] Our task? To position and detonate two 1000-kilo explosive charges on the bottom of Kenya's Lake Turkana. The year was 1990, and these blasts would allow seismometers placed up and down remote parts of the East African Rift to record sound waves from explosions and measure the structure of crust being pulled apart. To collect accurate data, we had to detonate the explosions exactly on time. As an inexperienced graduate student, my job was to pilot the Zodiac raft laden with plastic explosives. Setting the charges on the glassy lake in the morning was easy; we just had to pitch the explosive sausages overboard into a big pile on the lake bottom. We cleverly marked the shot locations with buoys made from empty water jugs anchored with rocks. Returning in the afternoon, we found that the wind had stirred up the lake surface into considerable swells. Finding the small white buoys in a sea of whitecaps was challenging. We found the first of the two, attached the electrical line, reeled off 500 feet of cable, and detonated without incident. But now we had only 10 minutes to find the second, and the wind was fierce. After 9 minutes, we located the small jug. We had time to back off only about 100 feet before hitting the button. The result? Nothing. What we didn't know was that the wind had blown the buoy about 100 feet away from the charge, dragging its inadequate anchor with it. That shift placed us directly above the explosives. So, although we didn't see the plume of water come off the shot, it wasn't long before we felt it. The blast launched the Zodiac and crew into the air. I dangled from the outboard motor and landed back in the lake with the raft, but my two companions were flung into the water. Luckily, the blast had scared the crocodiles away. Under a rain of dead tilapia and muddy water, we hauled back into the boat and started it up. Our only wounds were bruised bottoms from the force of the blast under us. We limped back to shore, where a Kenyan Ministry official had come to keep tabs on us and our effects on the fish. We approached him sheepishly, but he only commented that the second blast had seemed much smaller than the first. [1]: pending:yes [2]: http://PETERHOEY.COM
Excessive cocaine use results from decreased phasic dopamine signaling in the striatum

Drug addiction is a neuropsychiatric disorder marked by escalating drug use. Dopamine neurotransmission in the ventromedial striatum (VMS) mediates acute reinforcing effects of abused drugs, but with protracted use the dorsolateral striatum is thought to assume control over drug seeking. We measured striatal dopamine release during a cocaine self-administration regimen that produced escalation of drug taking in rats. Surprisingly, we found that phasic dopamine decreased in both regions as the rate of cocaine intake increased, with the decrement in dopamine in the VMS significantly correlated with the rate of escalation. Administration of the dopamine precursor L-DOPA at a dose that replenished dopamine signaling in the VMS reversed escalation, thereby demonstrating a causal relationship between diminished dopamine transmission and excessive drug use. Together these data provide mechanistic and therapeutic insight into the excessive drug intake that emerges following protracted use.
Integration of the Client Self-Care Commitment Model in a dental hygiene Curriculum

Objective This exploratory study investigated whether integration of the Client Self-Care Commitment Model (CSCCM) Instructional Module in a dental hygiene curriculum, as an additional educational experience, would further enhance students' client-centred knowledge, values and actions. Methods Subjects (n = 26) were second-year students enrolled in a BS entry-level dental hygiene programme with random assignments to two groups. The experimental group participated in a 2-h didactic session, an 8-h preclinical session, an 8-h clinical session and a 1-h question and answer period. An online pretest–post-test survey administered at three time intervals (baseline, 3 and 6 weeks) was used to measure differences between the groups on three subscales (knowledge, values and actions). Results Cronbach's α for each subscale across time was above 0.90. A repeated-measures anova determined that there were no statistically significant interactions between Time and Group (experimental or control group) for the knowledge and values variables; however, there was a significant interaction between Time (P = 0.003) and Group (P = 0.033) for the actions variable. A content analysis of participants' responses to three open-ended questions reflected both positive and negative comments and revealed that students' primary barrier to implementing the model in client care was lack of time. Conclusions Significant differences in the actions variable between the groups suggested that implementation of the CSCCM Instructional Module enhanced students' client-centred actions during client care.
Comparison of the INDO band structures of polyacetylene, polythiophene, polyfuran, and polypyrrole

The intermediate neglect of differential overlap (INDO) band structures of polythiophene, polyfuran, and polypyrrole are analyzed in terms of the band structure of polyacetylene. This is done by decoupling the INDO Fock operator to obtain the band structure of the carbon system and of the heteroatoms. For all three polymer systems, the highest valence band is essentially a pure carbon band, whereas the lowest conduction band is a strong mixture of carbon and heteroatom bands. This suggests that the electron and hole should show distinct properties. This difference between the electron and hole can be understood in terms of coupling between the respective Wannier functions of polyacetylene and the heteroatoms. Polypyrrole shows a stronger coupling between the carbon and heteroatom bands than polythiophene or polyfuran.
Reciprocal retinal transplantation: A tool for the study of an inherited retinal degeneration

The pathogenesis of retinal degeneration in rd mutant mice has been extensively studied, the gene responsible for the defect has been cloned, and the neural retina has been identified as the primary site for the degeneration. However, the possible contributory role of the ocular environment in this form of retinal degeneration remains undetermined. Retinal transplantation, which provides the opportunity to implant the neural retinal into a genetically defined intraocular environment, was used to examine this possibility. A reciprocal retinal transplantation paradigm was designed based on three experimental groups: (1) normal immature retina transplanted into rd/rd mutant eyes, (2) rd/rd immature retina transplanted into normal eye, and (3) normal immature retina transplanted into normal eyes. The rates of survival and histological characteristics of the grafts were compared between the three groups. At post-transplantation Day 3 (PTD 3), there were no differences between the three groups. Between PTD 10 and 15, the retinal grafts in group 1 showed degeneration. In contrast, the retinal grafts in groups 2 and 3 survived and developed well. At PTD 30, the retinal grafts in both groups 1 and 2 showed degeneration, but the retinal grafts in group 3 survived and remained differentiated well. These results suggest that the retinal degeneration of rd mice may be caused by both a deficit of the neural retina and intraocular environmental changes which are elicited either as a result of mutation or as a sequel to retinal degeneration.