cssi/SciSciGPT-SciSciNet huggingface dataset:
Nonparametric Bayesian Modeling for Multivariate Ordinal Data

This article proposes a probability model for k-dimensional ordinal outcomes, that is, it considers inference for data recorded in k-dimensional contingency tables with ordinal factors. The proposed approach is based on full posterior inference, assuming a flexible underlying prior probability model for the contingency table cell probabilities. We use a variation of the traditional multivariate probit model, with latent scores that determine the observed data. In our model, a mixture of normals prior replaces the usual single multivariate normal model for the latent variables. By augmenting the prior model to a mixture of normals we generalize inference in two important ways. First, we allow for varying local dependence structure across the contingency table. Second, inference in ordinal multivariate probit models is plagued by problems related to the choice and resampling of cutoffs defined for these latent variables. We show how the proposed mixture model approach entirely removes these problems. We ill...
Statistical errors in acoustic intensity measurements

Abstract A bivariate stochastic process is used to evaluate sources of error in acoustic intensity measurements. Three acoustic intensity estimators are examined for both bias and random errors. All three acoustic intensity estimators are shown to be biased by the presence of a second uncorrelated acoustic source. It is further shown that the presence of phase errors introduces additional bias which may limit the accuracy at low frequency. An expression is derived for the normalized standard error of the acoustic intensity estimates. The normalized standard error is a strong function of the coherence function and the phase angle spectrum, with maximum error occurring at low frequency and low coherence. Further interpretation of the normalized standard error is given by using two monopole acoustic sources as components in the bivariate process.
Cardiopulmonary rehabilitation in a patient with Noonan syndrome

Abstract Callahan MP, Pham T, Rashbaum I, Pineda H, Greenspan N. Cardiopulmonary rehabilitation in a patient with Noonan syndrome. Arch Phys Med Rehabil 2000;81:230-2. Noonan syndrome, an autosomal dominant disease occurring with an incidence of 1 in 1,000 to 1 in 2,500 live births, is characterized by its particular cardiovascular abnormalities, including pulmonic valve stenosis, pulmonary artery stenosis, and, more rarely, septal defects and coarctation of the aorta. The case of a 20-year-old man admitted for inpatient cardiopulmonary rehabilitation after pulmonic valve repair, left pulmonary artery angioplasty, and pectus excavatum repair is presented. His endurance was markedly decreased, thus limiting his ability to perform activities of daily living and reducing his exercise tolerance. With participation in a comprehensive cardiopulmonary rehabilitation program, he experienced marked improvement with independence in his activities of daily living and an increase in his metabolic equivalent levels from to 2.8 to 5.4. After inpatient rehabilitation, he underwent left pulmonary stent placement before being discharged home. Subsequent outpatient cardiopulmonary rehabilitation has continued to improve significantly his overall exercise tolerance. Given that Noonan syndrome is viewed as the most common syndrome associated with congenital heart disease after Down syndrome, physiatrists must be familiar with its presentation, its associated abnormalities, and the treatment approach to optimize the patient's cardiopulmonary, musculoskeletal, and psychological status. © 2000 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
Limitations of the Countershock Dose Response: A Study of Transthoracic Current

Dose response assessment of countershock efficacy has been widely determined with respect to energy but not current. The purpose of this study was to examine the utility of the dose response method in a current-based model of transthoracic defibrillation (pentobarbital anesthetized dogs, n = 8). Ventricular fibrillation induction lasting 15 seconds was separated by 5-minute intervals. Current defibrillation threshold (DFT; the lowest current that successfully defibrillated) was determined by decreasing current on successive trials. Energy DFT equaled the energy value of the corresponding current DFT. Subsequent data were expressed in normalized terms with each DFT assigned a normalized value of 1.00. Three shocks were delivered in random order at each of seven normalized current nodes (total of 21 shocks): 0.55, 0.70, 0.85, 1.00, 1.15, 1.30, and 2.00 x DFT (early testing). Randomization was repeated, and a second set of 21 trials were performed (late testing). Composite plots were made relating normalized current and energy to the percent successful defibrillation. The dose response expressed in normalized energy demonstrated an overall shift to the left compared to current. The difference was significant at every node value below the estimated DFT. Ninety percent of successful trials with respect to current and energy occurred at or above 0.85 DFT and 0.55 DFT, respectively. Significant changes in impedance occurred between early testing (60 +/- 6 ohms) and late testing (47 +/- 5 ohms), n = 8, mean +/- SD. Current, compared to energy, is a more accurate parameter in the dose response assessment of transthoracic defibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)
Field Experiments Examining the Culture of Honor: The Role of Institutions in Perpetuating Norms about Violence

Two field experiments illustrate how institutions of the U.S. South and West can help perpetuate violence related to a culture of honor. In Study 1, employers across the United States were sent letters from job applicants who had allegedly killed someone in an honor-related conflict. Southern and western companies were more likely than their northern counterparts to respond in an understanding and cooperative way. In Study 2, newspapers were sent facts for a story concerning a stabbing in response to a family insult. Southern and western papers created stories that were more sympathetic toward the perpetrator and presented his actions as more justified than northern papers did. Control conditions in both studies showed that the greater sympathy of southern and western institutions involves honor-related violence, not all violence or crime in general. Findings highlight the importance of examining the role of institutional behavior in perpetuating culture.
Stage IV Chronic Kidney Disease

A 54-year-old woman with type 2 diabetes presents for care. Her creatinine level has increased from 1.1 mg per deciliter (97 μmol per liter) 4 years ago to 3.1 mg per deciliter (274 μmol per liter) at the most recent measurement (estimated glomerular filtration rate, 26 ml per minute per 1.73 m2 of body-surface area). Her urinary protein excretion is 2.8 g per 24 hours. Her blood pressure is 155/90 mm Hg, and the glycated hemoglobin level is 7.6 mg per deciliter. Her current medications include an oral hypoglycemic agent, an angiotensin-converting–enzyme inhibitor, a statin, and a thiazide diuretic. How should her case be managed?
Run-in and glaze formation on gray cast iron surfaces

Abstract The chief processes involved in run-in of cast iron are smoothing of the surface and formation of a surface coating derived largely from the graphite in the metal structure and iron oxide (Fe3O4). Much of the smoothing can be attributed to this coating rather than to a wearing off or “squashing” of asperities. It may be almost 1 mil thick and its exact composition varies from point to point along the surface. In the case of a specimen run-in with a non-additive oil under laboratory conditions, the carbon content ranged from 30 to 100% and the remainder could be accounted for by Fe3O4, although on an engine cylinder bore it contains significant amounts of other components. This “glaze” doubtlessly imparts a resistance to scuffing during momentary contacts between the mating surfaces but, possibly more important, by covering surface irregularities it produces a smooth surface which allows higher loads to be carried by a fully hydrodynamic lubricant film.
Radical Awareness and Word Acquisition Among Nonnative Learners of Chinese

This study investigates developmental trends in acquiring knowledge of radicals, radical perception skills, and skills in applying knowledge of radicals among nonnative learners of Chinese across learning levels. It also examines the relationship between the acquisition of radical knowledge and the development of radical perception and radical knowledge application skills, as well as how the development of radical knowledge application skills is associated with Chinese word acquisition. The results of this study suggest that radical knowledge, radical perception skills, and radical knowledge application skills do not develop synchronously across learning levels, but rather that each of them shows a unique developmental trend. A linear trend exists between the development of radical knowledge and the application of this knowledge; a moderate positive association is observed between the development of radical knowledge application skills and Chinese word acquisition. The pedagogical implications of these findings are suggested.
Hybrid Spiral Plasmonic Lens: Towards High Efficiency Miniature Circular Polarization Analyzer

A hybrid plasmonic lens with alternating spiral slot and spiral triangle array focuses left-handed and right-handed circular polarization into spatially separated plasmonic fields, which may serve as a high efficiency circular polarization analyzer.
A procedural condition necessary and sufficient for cyclic social preference

Abstract Several variations and generalizations of the Voting Paradox show that social-preference cycles are not peculiar to majority rule. I offer a new generalization that is demonstrably as general as possible: a relaxation of majority rule is necessary for a cycle of any sort and sufficient for a dominant one—given certain background assumptions, few and familiar. In its “Latin square” proof as well as its assumptions, the sufficiency theorem directly generalizes both the Voting Paradox and Sen's Liberal Paradox.
Uptake and transport of shell minerals in Glottidia pyramidata Stimpson (Brachiopoda: Inarticulata)

Abstract Uptake and transport of shell mineral ions have been investigated in the lingulid brachiopod Glottidia pyramidata Stimpson by tracer techniques and histochemical methods at the ultrastructural level. 45 Ca autoradiography as well as 45 Ca uptake studies show that Ca ions are taken up from the seawater medium primarily by the iophophore and then move through the coelomic system into the mantle and eventually are deposited in the inner shell layer. The rate of Ca deposition in the apatite shell is 12 × 10 −2 μg · mg −1 shell weight ·h −1 , which is similar to that in the calcite shell of the bivalve Argopecten . Potassium antimonate staining for Ca, X-ray microanalysis and electron diffraction analysis further suggest that Ca along with inorganic phosphate are deposited in large vacuoles in the mantle epithelium to form granules of a mixture of apatite crystals and sometimes of amorphous materials. These granules serve as reservoirs of shell minerals. In contrast to 45 Ca, 32 P uptake from seawater is lower in the shell than in other parts of the animal. Therefore, the major source of inorganic phosphate for Glottidia shell formation is unlikely to be the seawater.
Determination of atomic binding sites on the fcc (111) plane

Abstract On the close-packed (111) plane of the fcc lattice, two different types of positions at which atoms are bound can be distinguished: bulk (fcc) and surface (hcp) sites. Although the detailed atomic arrangement of the fcc (111) plane is not resolved in the field ion microscope, the location and nature of the sites can be readily determined by observing the location of an adatom after diffusion. This mapping technique, although basic to site identification, is quite time consuming. In its stead, the appearance of the image spot produced by an individual adatom serves as a reliable indicator of the type of site occupied. Observations of the intensity distribution as well as of the site occupation for chemically different atoms suggest a strong dependence of both upon the electronic structure of the adatom.
Forest plant and bird communities in the Lau Group, Fiji.

Background We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km2), Nayau (18.4 km2), and Aiwa Levu (1.2 km2), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity. Methodology/Principal Findings All trees >5 cm diameter were measured and identified in 23 forest plots of 500 m2 each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging) than to environmental gradients (elevation, slope, rockiness). Our point counts (73 locations in 1 or 2 seasons) recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited) island of Aiwa Levu than on the much larger island of Lakeba. Conclusions/Significance Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human disturbance.
Automated cache optimizations using CME driven diagnosis

Demonstrating our framework on a collection of scientific loop nests, we were able to reduce an average of 84% of cache misses in the optimizable loop nests. This work lays the groundwork for handling a wide range of optimizations through further study of solution patterns in the CME solution table.
A mutant plasma membrane ATPase, Pma1-10, is defective in stability at the yeast cell surface

Pma1 is a plasma membrane H(+)-ATPase whose activity at the cell surface is essential for cell viability. In this paper we describe a temperature-sensitive pma1 allele, pma1-10 (with two point mutations in the first cytoplasmic loop of Pma1), in which the newly synthesized mutant protein fails to remain stable at the cell surface at 37 degrees C. Instead, Pma1-10 appears to undergo internalization for vacuolar degradation in a manner dependent on End4, Vps27, Doa4, and Pep4. By contrast with wild-type Pma1, mutant Pma1-10 is hypophosphorylated and fails to associate with a Triton-insoluble fraction at 37 degrees C, suggesting failure to enter lipid rafts. Kinetic analysis reveals that, at the permissive temperature, newly synthesized Pma1-10 acquires Triton-insolubility before becoming stabilized. We suggest that phosphorylation and lipid raft association may play important roles in maintaining protein stability at the plasma membrane.
Testing of transition-region models

An approach for the comprehensive testing of transition-region models is described. This approach emphasizes the need to evaluate the models in all of the flow scenarios for which they are likely to be used. As an example of the procedure, seven different types of transitioning flows are described and experiments illustrating the different scenarios are discussed. Two transition-region models are used to predict mean-flow quantities for all of the cases and selected results are reported.
Hydrothermal synthesis and structural determination of a three-dimensional microporous iron(III)phosphate: [H3N(CH2)4NH3]3[Fe8(HPO4)12(PO4)2(H2O)6]

Abstract A new microporous iron (III) phosphate, [H 3 N(CH 2 ) 4 NH 3 ] 3 [Fe 8 (HPO 4 ) 12 (PO 4 ) 2 (H 2 O) 6 ], has been prepared using low temperature hydrothermal methods and characterized by single-crystal X-ray diffraction, EDAX, infrared spectroscopy, thermogravimetric analysis and bond valence sums. The title compound crystallizes as light pink hexagonal-shaped tabs in the centrosymmetric hexagonal space group 3¯ (No.147) with a = b = 13.495(2) A, c = 9.396(2) A, V = 1481.9(4) A 3 and Z = 4 with R/R w = 0.044/0.048. The compound exhibits a complicated three-dimensional microporous structure with quaternary ammonium ions acting as a template for the framework. It is similar to previously reported [HN(CH 2 CH 2 ) 3 NH] 3 [Fe 8 (HPO 4 ) 12 (PO 4 ) 2 (H 2 O) 6 ].
Demand for Immunization, Parental Selection, and Child Survival: Evidence from Rural India*

This study focuses on the estimation of demand for immunization as well as its technological effect on the survival probability of a child in rural India. Careful attention is paid to the consequences of parental selection on survival technology and demand for health inputs. The results suggest that child mortality is negatively related to the likelihood of purchasing vaccination, but imperfect vaccination substantially reduce the beneficial effect. Results also suggest that a mother who perceives her child faces a risk of higher likelihood of death compensates for their beliefs in a beneficial way. Consequently, estimations that ignore this selection underestimate the impact of immunization on child survival. Mothers also engage in complementary behavior by reinforcing investment when they choose among health inputs. Estimations that ignore the complementarity substantially overstate the impact of prenatal care and delivery care on demand for immunization. The evidence for complementarity among measured inputs also implies that there might be favorable selection between measured and unmeasured inputs, although the adverse selection seems dominant in this study.
Polyamine involvement in the secretion and action of TGF-α in hormone sensitive human breast cancer cells in culture

These experiments were designed to test polyamine (PA) involvement in the secretion and action of transforming growth factor alpha (TGF-alpha) in hormone responsive MCF-7 breast cancer cells in liquid culture. At the same time, we evaluated the influence of culture conditions (with serum vs. serum depleted) and subclonality of MCF-7 cells on PA involvement in estrogen (E2) and TGF-alpha stimulated cell proliferation. Despite inducing a profound suppression of cellular PA levels and inhibiting basal and E2-stimulated growth, administration of the PA synthesis inhibitor alpha-difluoromethylornithine (DFMO) did not influence either basal or E2-induced TGF-alpha secretion. In the same experiments, on the other hand, addition of DFMO completely blocked the growth stimulatory effect of exogenous TGF-alpha. However, when the culture conditions were changed to serum-free medium, TGF-alpha and E2-induced cell proliferation was affected modestly or not at all by DFMO administration, despite similar suppression of cellular ornithine decarboxylase (ODC) activity and PA levels. In addition, different clones of MCF-7 cells differed in their sensitivity to the antiproliferative effect of DFMO as well as in basal levels of ODC activity and PA. We conclude that PAs are not involved in basal or E2-stimulated TGF-alpha secretion in MCF-7 breast cancer cells. On the other hand, PAs do seem to be important mediators of TGF-alpha and E2-induced breast cancer cell proliferation, though the degree of such involvement appears to be influenced by serum factors and clonal variability of MCF-7 cells.
Analysis of the Nevada-Applied-Ecology-Group model of transuranic radionuclide transport and dose

Abstract The authors analyze the model for estimating the dose from 239Pu developed for the Nevada Applied Ecology Group (NAEG) by using sensitivity analysis and uncertainty analysis. Sensitivity analysis results suggest that the inhalation pathway is the critical pathway for the organs receiving the highest dose. Soil concentration and the factors controlling air concentration are the most important parameters. The only organ whose dose is sensitive to parameters in the ingestion pathway is the GI tract. The inhalation pathway accounts for 100% of the dose to lung, upper respiratory tract and thoracic lymph nodes; and 95% of the dose to liver, bone, kidney and total body. The GI tract receives 99% of its dose via ingestion. Leafy vegetable ingestion accounts for 70% of the dose from the ingestion pathway regardless of organ, peeled vegetables 20%; accidental soil ingestion 5%; ingestion of beef liver 4%; beef muscle 1%. Only a handful model parameters control the dose for any one organ. The number of important parameters is usually less than 10. Uncertainty analysis indicates that choosing a uniform distribution for the input parameters produces a lognormal distribution of the dose. The ratio of the square root of the variance to the mean is three times greater for the doses than it is for the individual parameters. As found by the sensitivity analysis, the uncertainty analysis suggests that only a few parameters control the dose for each organ. All organs have similar distributions and variance to mean ratios except for the lymph nodes.
Ion mobility-mass spectrometry analysis of isomeric carbohydrate precursor ions

The rapid separation of isomeric precursor ions of oligosaccharides prior to their analysis by mass spectrometry to the nth power (MSn) was demonstrated using an ambient pressure ion mobility spectrometer (IMS) interfaced with a quadrupole ion trap. Separations were not limited to specific types of isomers; representative isomers differing solely in the stereochemistry of sugars, in their anomeric configurations, and in their overall branching patterns and linkage positions could be resolved in the millisecond time frame. Physical separation of precursor ions permitted independent mass spectra of individual oligosaccharide isomers to be acquired to at least MS3, the number of stages of dissociation limited only practically by the abundance of specific product ions. IMS–MSn analysis was particularly valuable in the evaluation of isomeric oligosaccharides that yielded identical sets of product ions in tandem mass spectrometry experiments, revealing pairs of isomers that would otherwise not be known to be present in a mixture if evaluated solely by MS dissociation methods alone. A practical example of IMS–MSn analysis of a set of isomers included within a single high-performance liquid chromatography fraction of oligosaccharides released from bovine submaxillary mucin is described.
Uncharacteristic Earthquakes on the San Andreas Fault

One model of earthquake recurrence holds that large quakes exhibit regular or characteristic rupture patterns. Combined with a simple picture of how elastic strain accumulates in the faults, this implies that characteristic earthquakes occur at regular intervals. In her Perspective, Grant proposes that recent data from study sites along the San Andreas fault are difficult to understand with this model. The earthquake activity is more irregular and more clustered than the model would suggest.
Inhibition of CDK-mediated phosphorylation of Smad3 results in decreased oncogenesis in triple negative breast cancer cells

Breast cancer onset and disease progression have been linked to members of the TGFβ superfamily and their downstream signaling components, the Smads. Alterations in Smad3 signaling are associated with the dichotomous role of TGFβ in malignancy, mediating both tumor suppressant and pro-metastatic behaviors. Overexpression of cell cycle regulators, cyclins D and E, renders cyclin-dependent kinases (CDKs) 4/2 hyperactive. Noncanonical phosphorylation of Smad3 by CDK4/2 inhibits tumor suppressant actions of Smad3. We hypothesized that CDK inhibition (CDKi) would restore Smad3 action and help promote cancer cell regression. Treatment of triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, MDA-MB-436, Hs578T) with CDK2i or CDK4i resulted in increased Smad3 activity and decreased cell migration. Transfection with a 5M Smad3 construct containing inhibitory mutations in 5 CDK phosphorylation sites also resulted in decreased TNBC cell migration and invasion. MDA-MB-231 cells treated with CDK2i or CDK4i resulted in decreased Smad3 protein phosphorylation at the CDK phosphorylation T179 site, decreased MMP2 and c-myc expression, and increased p15 and p21 expression. Using a novel transfected cell array, we found that CDK2i treatment decreased activity of the epithelial-to-mesenchymal transition related transcription factors Snail and Twist. In vivo studies in an MDA-MB-231 tumor model showed that individual and combination treatment with paclitaxel and CDK2i resulted in decreased tumor volume and Ki67 staining. Collectively, these data support further investigation of targeted CDK inhibitors as a promising therapeutic strategy for TNBC, a breast cancer subtype with limited treatment options.
The Laws Have Changed, But What About the Police? Policing Domestic Violence in Bosnia and Herzegovina

Despite having received gender sensitivity and domestic violence (DV) education in the post-war reformation era, anecdotal evidence from across Bosnia and Herzegovina indicates that most police officers view DV as a private family affair and continue to hold negative attitudes toward women and DV victims. This study assessed these claims by examining gender and DV attitudes held by 137 Bosnian police officers. It was hypothesized that officers who received DV training would be less likely to hold sexist attitudes toward women or view DV as justifiable compared with untrained officers. Results, as well as policy implications and suggestions for future research, are presented.
Determination of small quantities of nitrogen in serological precipitates and other biological materials.

SummaryA simple and accurate colorimetric method is described for the routine determination of quantities of nitrogen in the range from 5 to 80 y. The method, which is a modification of the direct-nesslerization procedure of Koch and McMeekin, has been developed especially for the analysis of serological precipitates, but is adapted readily to the analysis of protein solutions.
Ultraviolet absorption and epidermal-transmittance spectra in foliage

We examined the UV absorption spectra and the epidermal-transmittance spectra (280–350 nm) of foliage from 42 plant species. Sun foliage was sampled from naturally growing individuals of seven species in each of six life forms comprising two evergreen groups (gymnosperms and angiosperms) and four deciduous angiosperm groups (trees, shrubs and vines, herbaceous dicotyledons and grasses). There were large differences in absorption spectra of whole-leaf extracts among species. While absorbance declined with increasing wavelength in most woody species, there was a trough in absorbance around 300 nm in many herbaceous species. Absorption spectra were negatively correlated with epidermal-transmittance spectra in 31 of the 42 species. Relationships between absorbance and transmittance did not follow the theoretical exponential function. Species rankings of UV-screening effectiveness were similar when we assessed it by using epidermal transmittance at single wavelengths (300 or 320 nm) or different UV-action spectra to weight epidermal-transmittance spectra and estimate the levels of biologically effective UV reaching the mesophyll. Thus, differences in absolute epidermal transmittance among species appeared to overshadow spectral differences. Nevertheless, the differences we found in the internal UV spectral regime in foliage suggest that whole-plant action spectra will differ among species. While species rankings of UV-screening effectiveness were similar when different action spectra were used, the absolute amounts of biologically effective UV reaching the mesophyll of species varied considerably when different action spectra were used.
Assessing the accuracy of two proxy measures for BMI in a semi-rural, low-resource setting in Guatemala

Validation studies of self-reported BMI are limited to populations in high-income countries or urban settings. Here, we assess the accuracy of two proxy measures of measured height, weight and BMI – self-reported values and the Stunkard figure scale – in a semi-rural population in Guatemala. Self-reported values and Stunkard figure selection were elicited prior to biometric measurements from a total of 175 non-pregnant women recruited based on a stratified random sample of households, with 92 women providing full data for validation across measures. 86.3% of participants self-reported weight and 62.3% height. Among those responding, self-reported weight is highly accurate though lower relationships for height contribute to error in reported BMI. The Stunkard scale has a higher response rate (97.1%) and while less accurate in predicting BMI values, more accurately predicts BMI categories. Self-reported measures are more accurate than the Stunkard scale in estimating BMI values, while the latter is more accurate in estimating BMI categories. High non-response rates and lower correlations between reported and measured height caution against using self-reported biometric data other than raw weight in low-resource settings.
Membrane assembly from purified components. II. Assembly of M13 procoat into liposomes reconstituted with purified leader peptidase

The major coat protein of coliphage M13 is an integral protein of the E. coli plasma membrane prior to its assembly into new virus particles. It is generated from its precursor, procoat, by a membrane-bound leader peptidase. We now describe the reconstitution of a highly purified preparation of this enzyme into vesicles of E. coli phospholipids. These vesicles bind procoat made in vitro and procoat isolated from in vitro synthesis. Both the crude and the purified substrates were converted post-translationally to coat protein. A significant proportion of the coat protein becomes inserted into the vesicle bilayer, with the N terminus facing the vesicle interior and the C terminus exposed to the external medium. These results strongly suggest that highly purified leader peptidase from E. coli and phospholipids are the only components necessary to mediate the binding, processing and insertion of this integral membrane protein.
Feasibility Study on a Hyperacuity Device With Motion Uncertainty: Two-Point Stimuli

Can a device that can perform hyperacuity vision tasks be built? In this paper, a feasibility study based on separation discrimination is conducted. Two types of ideal detectors are considered. The first is the stimulus defined statistically (SDS) detector by Geisler and Davilla. The second is one that estimates the uncertainty and then takes out its effect. In the first method, an array of many ideal stimulus defined exactly (SDE) detectors covers uncertainties and forms the ideal SDS detector. When the separation distance between the SDE detectors is around 1 arcmin, the SDS detector can achieve nearly optimal performance. To cover the motion uncertainty with nearly optimal performance, the SDE detector at each position needs to cover 16 directions, and at each direction, it needs to cover speeds with an increment of 0.5deg/s. Typically, the SDS detector needs 7776 SDE detectors to deal with a speed up to 2deg/s stimulus movement with a randomly selected direction and a 9 min times 9 min position uncertainty region. This ideal observer can achieve a hyperacuity threshold of 2-4 arcsec. Its threshold is almost constant over the range of speeds covered by the SDS detector. Using the second method, position estimation and motion tracking capability is examined. With perfect position estimation and motion tracking, the SDS detector can be reduced to a single SDE detector that is tuned to correct position and motion direction and speed. Two lower bounds on the estimation variance are examined, namely: 1) the Cramer-Rao bound and 2) the Ziv-Zakai bound. The results showed that if an estimation algorithm that can achieve the performance of bounds can be found, then the second method could achieve a hyperacuity capability of 1 s or less. The human visual system may more likely adopt the first method, but the second is simpler to use in building up a device using microprocessors. In this paper, dot-pair templates are used, which precisely match to dot-pair stimuli, to compute the likelihood and make a decision. The main difference between this paper and that of Geisler and Davilla lies in using a discrete sum over an array of SDE detectors to closely approximate continuous integration over the uncertain region, which makes it much easier in hardware implementation
The Effects of Heavy Metal Mine Drainage on Population Size Structure, Reproduction, and Condition of Western Mosquitofish, Gambusia affinis

Anthropogenic degradation of aquatic environments worldwide results in disturbed habitats, altered communities, and stressed populations. Surface waters located in an abandoned lead-zinc mining district in northeastern Oklahoma are no exception. This study examines the reproductive and somatic responses of a pollution-tolerant fish, the western mosquitofish, Gambusia affinis (Teleostei: Poeciliidae), living in mine outflow waters contaminated by heavy metals. Populations were sampled from four streams, which were classified into three habitat types. Populations from Tar Creek and an Unnamed Tributary of Tar Creek receive direct input of mine drainage, while populations living in reference creeks are not known to have mining influence. The influence of mine drainage directly or indirectly (via altered competitor and predator regimes or changes in food availability) affects G. affinis at both the population and the individual level. Metal-contaminated sites had reduced proportions of males and reproductively active females and altered male population size structures. Individual-level effects were apparent, as all G. affinis from Tar Creek invested less in liver weights, and mature males and reproductively active females from Tar Creek invested less in gonad weights. Furthermore, males from impacted sites were significantly lighter than those from reference creeks. Gravid females from Tar Creek had smaller clutch sizes, but average embryo weight did not differ among streams.
Intronic snoRNA biosynthesis in Saccharomyces cerevisiae depends on the lariat-debranching enzyme: intron length effects and activity of a precursor snoRNA.

The eukaryotic small nucleolar RNAs (snoRNAs) are involved in processing of pre-rRNA and modification of rRNA nucleotides. Some snoRNAs are derived from mono- or polycistronic transcription units, whereas others are encoded in introns of protein genes. The present study addresses the role of the RNA lariat-debranching enzyme (Dbr1p) in the synthesis and function of intronic snoRNAs in the yeast Saccharomyces cerevisiae. Intronic snoRNA production was determined to depend on Dbr1p. Accumulation of mature intronic snoRNAs is reduced in a dbr1 mutant; instead, intronic snoRNAs are "trapped" within host intron lariats. Interestingly, the extent of intronic snoRNA accumulation in the form of lariats in dbr1 cells varied among different intronic snoRNAs. Intronic snoRNAs encoded within shorter introns, such as U24 and snR38, accumulate more unprocessed lariat precursors than those encoded within longer introns, e.g., U18 and snR39. This correlation was corroborated by experiments conducted with model intron:U24 snoRNA constructs. These results support a splicing-dependent exonucleolytic pathway for the biosynthesis of intronic snoRNAs. Curiously, U24 in a lariat may be functional in directing methylation of ribosomal RNA.
Variation in In Vitro α-Amylase and Protease Activity Is Related to the Virulence of Aspergillus flavus Isolates

Variation in the ability of Aspergillus flavus isolates to spread between cotton boll locules was previously shown to be at least partially related to variation in the production of a specific polygalacturonase (pectinase P2C). To determine if non-pectolytic hydrolase differences between low- and high-virulence isolates exist and, thus, could also potentially contribute to virulence differences, the present investigation was undertaken. Two A. flavus isolates, AF12 with low virulence and lacking pectinase P2C and AF13 with high virulence and producing pectinase P2C, were compared for production of nonpectolytic hydrolases after growth in 10% potato dextrose broth. Activity of amylases, cellulases, xylanases, and proteases was quantified using the radial diffusion/cup plate technique followed by differential staining. Culture filtrates also were subjected to native polyacrylamide gel electrophoresis. Both isolates produced amylases, proteases, and xylanases, whereas cellulases were not detected for either. AF13 produced more amylase than AF12, and this difference was supported by amylase isoform differences between isolates on native polyacrylamide gel electrophoresis gels. AF13 also produced more protease than AF12; however, isoform differences between isolates were inconclusive. These variations in other hydrolytic activities (besides pectinases) may contribute to virulence differences in cotton bolls between AF12 and AF13.
GINGER RHIZOME: A NEW SOURCE OF PROTEOLYTIC ENZYME

The proteolytic activity of ginger rhizome was studied with bovine serum albumin (BSA), collagen and actomyosin as substrates. A semipurified, powdered enzyme preparation was prepared by buffer extraction of an acetone powder of ginger rhizome and subsequent acetone precipitation of the proteolytic principle from the buffer extract. With 3% BSA as substrate, a relatively high proteolytic activity occurred over a pH range of 4.5–6.0, with an optimum pH of 5.0. The optimum temperature for proteolysis of BSA was 60°C during a 10 min reaction time, with rapid denaturation of the enzyme occurring at 70° C. NaCl in cone up to 10% produced about a 20 and 50% reduction in proteolysis of collagen and BSA, respectively. The ginger protease was protected by dithiothreitol during extraction and reaction, indicating the involvement of −SH groups at the active site. The analyses of soluble peptide amino acids or terminal amino acids suggest that the proteolysis of collagen is many fold greater than that of actomyosin. The combined proteolysis of these two muscle protein fractions by the ginger protease resulted in significantly more tender meat. According to conventional nomenclature, “Zingibain” is the proper name for this proteolytically active principle in Zingiber officinale roscoe or ginger rhizome which is commonly referred to as gingerroot. For meat applications, a possible advantage of zingibain over papain and ficin is the greater proteolysis of collagen in comparison to actomyosin. When compared to reported values for bromelain, zingibain has a higher optimum activity temperature, which is desirable in some applications
Distributed Random Access Algorithm: Scheduling and Congestion Control

This paper provides proofs of the rate stability, Harris recurrence, and e-optimality of carrier sense multiple access (CSMA) algorithms where the random access (or backoff) parameter of each node is adjusted dynamically. These algorithms require only local information and they are easy to implement. The setup is a network of wireless nodes with a fixed conflict graph that identifies pairs of nodes whose simultaneous transmissions conflict. The paper studies two algorithms. The first algorithm schedules transmissions to keep up with given arrival rates of packets. The second algorithm controls the arrivals in addition to the scheduling and attempts to maximize the sum of the utilities, in terms of the rates, of the packet flows at different nodes. For the first algorithm, the paper proves rate stability for strictly feasible arrival rates and also Harris recurrence of the queues. For the second algorithm, the paper proves the e-optimality in terms of the utilities of the allocated rates. Both algorithms are iterative and we study two versions of each of them. In the first version, both operate with strictly local information but have relatively weaker performance guarantees; under the second version, both provide stronger performance guarantees by utilizing the additional information of the number of nodes in the network.
A decentralized nonlinear three-term controller for manipulator trajectory tracking

A simple decentralized controller is proposed to enable accurate trajectory tracking without requiring specific knowledge about the robot dynamics. Asymptotic stability of tracking errors is established using the Lyapunov stability theory. The control system is shown to be robust to torque disturbances affecting the system and to a class of unmodeled dynamics. The structure of the controller and the performance of the closed-loop system are analyzed. Simulations results using the complete dynamic model of a six degree of freedom industrial robot are presented to demonstrate the excellent tracking performance of the proposed controller.
Computer innovation in higher education

In the absence of an extensive and intensive causal science of learning, computer applications for education have most often been shaped by external factors. Programming for the manipulation of numbers came first, followed by word processing and the manipulation of text. These are briefly discussed, and the potential of electronic mail and multimedia, which have not found much educational application as yet, is examined. >
Unified Theory of Oscillator Phase Noise I: White Noise

The spectral purity of every oscillator system is limited by phase noise. In this work, we extend the techniques previously used to analyze phase noise in lasers to develop an intuitive, yet powerful description of phase noise in an electromagnetic oscillator for the case when the oscillating field is sinusoidal and perturbed by white noise. The developed theory is general and unifies the understanding of phase noise in both electrical and optical oscillators. Our approach is based on partitioning the noise among the modes of the oscillator, which is analogous to the approach used to analyze phase noise in laser cavities, but has not been previously considered for electrical oscillators. We show that oscillator phase noise depends only on the oscillating power, injected noise, and round-trip delay. This result provides a theoretical foundation to and expands upon the predictions provided by Leeson's well-known empirical oscillator phase-noise model. To validate the developed theory, we compare the predicted phase noise to the experimentally measured phase noise of both a simple electrical oscillator and a hybrid opto-electronic oscillator and show excellent agreement across a wide range of operation.
Processes and Pathways: How Do Mathematics and Science Partnerships Measure and Promote Growth in Teacher Content Knowledge?

Intense focus on student achievement results in mathematics and science has brought about claims that K-12 teachers should be better prepared to teach basic concepts in these disciplines. The focus on teachers' mathematics and science content knowledge has been met by efforts to increase teacher knowledge through funded national initiatives focusing on mathematics and science. The purpose of the present study was to look across projects in the National Science Foundation's Math and Science Partnership Program to determine how partnerships developed processes for measuring growth in teacher content knowledge. Pre- and post-testing was the most common process for measuring growth in content knowledge, with 63% of the mathematics and 78% of the science teachers showing significant gains in content knowledge. A notable difference was found between teacher outcomes when the Learning Mathematics for Teaching instrument was used in comparison with the use of other instruments measuring teacher content knowledge growth. Results revealed two pathways for promoting teacher content knowledge growth: content explicit, where the goal of growth in teacher content knowledge was explicit in the activity, and content embedded, where the goal of growth in teacher content knowledge was embedded in the activity. As a result of the analysis, a framework demonstrating the interrelationships among processes and pathways was developed.1
Book Review, David R. Boyd, The Environmental Rights Revolution: A Global Study of Constitutions, Human Rights, and the Environment (UBC Press, W. Wesley Pue General Ed., 2012)

David R. Boyd’s book entitled, The Environmental Rights Revolution: A Global Study of Constitutions, Human Rights, and the Environment, provides a comprehensive overview of nations that have incorporated the right to a healthy environment in their constitutions. Throughout his research, Boyd analyzes the effectiveness of environmental protection provisions in national constitutions and seeks to determine whether constitutional provisions guaranteeing the right to a healthy environment have measurable, positive effects on the environment. His wide-ranging compilation and analysis of environmental rights provisions in numerous countries is an important contribution to international human rights literature. Although Boyd explains that treating the right to a healthy environment as a fundamental human right is not a new idea, his broad research demonstrates that many national constitutions have, in fact, adopted enforceable environmental protection provisions, particularly the right to a healthy environment. Boyd’s research provides concrete examples of how the constitutional right to a healthy environment, and national legislation guaranteeing that right, have had positive environmental consequences. He predicts that in the future these rights will continue to help combat the effects of global climate change and environmental degradation that permeate national borders to enable the world to achieve the goal of sustainable development.
Induction of Structural Alterations in the Preovulatory Amphibian Ovarian Follicle by Hormones

In vitro hormonal-induced structural changes in preovulatory frog ov arian follicles were studied. After fixation of hormone-treated follicl es separation of the follicular wall from the oocyte was observed. In unmixed follicles follicle cells separated from the exterior surface of the vitelline and the oocyte separated from the interior surface. This detachment seemed to occur simultaneously around the time of germinal vesicle breakdown within the follicular oocyte. Effective steroid inhibitors of germinal vesicle breakdown also caused membrane separation while estrogenic hormones were ineffectual in promoting either process. Progesterone was more effective and more immediate than frog pituitary hormones in stimulating these changes although the types of change were the same. These changes were inhibited by both puromycin and cycloheximide which suggests that protein synthesis has a role in the structural alteration of ovarian follicles. The findings suggest that structural alterations in the surface of the ovarian follicle and follicle rupture are necessary for ovulation to occur and that such events are mediated by hormones. The importance of these changes to follicular function are discussed.