cssi/SciSciGPT-SciSciNet huggingface dataset:
From random mutagenesis to systems biology in metabolic engineering of mammalian cells

Metabolic engineering is rapidly developing, with a continuous stream of technological developments being employed to expand the portfolio of molecules produced in cell factories. For chemical production (e.g., amino acids, biofuels, among others), metabolic engineering has progressed through three phases [1]. Initially, biological products were obtained through random mutagenesis of production strains and large screening efforts. Improved microbial strains could be isolated, but mechanisms underlying the desired phenotype were often poorly understood [2]. Diverse molecular biology techniques facilitated the second phase, in which simple, intuitive modifications were made. The third phase now employs systems biology techniques to understand the effect of modifications on all other metabolic pathways and on cell physiology. Thus, we have entered an era in which metabolic engineering aims to improve microbial strains in a reproducible fashion, using complex designs based on detailed biochemical knowledge and computational model simulations. Here, we highlight the historical progression toward using systems biology in microbial metabolic engineering and compare this to the current status of mammalian production cell line development. Finally, we discuss the unique challenges in engineering mammalian cell lines for biotherapeutic production and outline how systems biology can facilitate metabolic engineering efforts for these platforms. The systems biology approach to metabolic engineering has been enabled by three primary advancements: whole-genome sequencing, gene editing tools and genome-scale models of cellular metabolism. The completion of the Escherichia coli K-12 genome sequencing effort in 1997 [3] provided a comprehensive parts list for targeted metabolic engineering and expanded the scope of our understanding of the machinery within this microbe. The further development of efficient genetic modification systems, such as the lambda Red recombination system [4], enabled the deployment of targeted metabolic engineering designs, such as the removal of competing pathways that divert flux away from the formation of a desired product. Predictions of the systemic effects of genetic modifications were enabled when the information in the sequenced genome was harnessed for the development of genome-scale models of metabolism [5]. These models contain all known biochemical reactions in a cell, thus allowing one to predict the overall impact of modifications on phenotypic traits such as growth rate and small molecule secretion. Systems biology approaches are now important tools in microbial metabolic engineering. Yim et al. genetically modified E. coli to produce 1,4-butanediol (BDO) by introducing heterologous genes to allow Hooman Hefzi Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
Real-world printed circuit board ESD failures

ICs that are robust to ESD at the component-level may be damaged by ESD at the board-level. Two case studies show that real-world Charged Board Model (CBM) ESD damage is typically more severe than Human Body Model (HBM) or Charged Device Model (CDM) ESD damage. Consequently, CBM damage can be easily mistaken for electrical overstress (EOS) damage. A high-capacitance yet compact Printed Circuit Board (PCB) evaluation board facilitates qualitative CBM testing using conventional CDM test systems. Based on the case studies and test results, guidelines are provided on how to minimize the likelihood of real-world CBM failures.
Intent and the judgment of lies.

(1986). Intent and the Judgment of Lies. The Journal of Social Psychology: Vol. 126, No. 1, pp. 129-130.
Weight functions for bimaterial interface cracks

An efficient approach using the analytically decoupled near-tip displacement solution for bimaterial interface cracks presented in this paper involves: (1) the calculation of the decoupled strain energy release rates GI and GII associated respectively with the decoupled stress intensity factors KI and KII and (2) the extension of Rice's displacement derivative representation of Bueckner's weight function vectors beyond the homogeneous media. It is shown that the stress intensity factors for a bimaterial interface crack predicted by the present approach agree very well with those solutions available in the literature. The computational efficiency is enhanced through the use of singular elements in the crack-tip neighborhood.
Idiopathic giant retinal tears in identical twins

Abstract PURPOSE: To report idiopathic unilateral giant retinal tears with retinal detachment in identical twins that occurred 2 weeks apart. METHODS: Case reports. RESULTS: In both patients, giant retinal tear and retinal detachment was treated with pars plana vitrectomy, placement of encircling scleral buckle, fluid-perfluorocarbon exchange, endolaser treatment, perfluorocarbon-air exchange, and 16% perfluoropropane injection. One year after retinal detachment surgery, cataract developed in both postoperative eyes. Phacoemulsification with posterior chamber intraocular lens implantation was performed on both eyes. Three and a half years after retinal surgery, corrected visual acuity in both treated eyes was 20/20, and retinal reattachment was successful. CONCLUSIONS: To our knowledge, this is the first report of idiopathic giant retinal tears in identical twins and raises the issue of genetic influences in the pathogenesis of this disease.
Two-flux method for transient radiative transfer in a semitransparent layer

The two-flux method was used to obtain transient solutions for a plane layer including internal reflections and scattering. The layer was initially at uniform temperature, and was heated or cooled by external radiation and convection. The two-flux equations were examined as a means for evaluating the radiative flux gradient in the transient energy equation. Comparisons of transient temperature distributions using the two-flux method were made with results where the radiative flux gradient was evaluated from the exact radiative transfer equations. Good agreement was obtained for optical thicknesses from 0.5 to 5 and for refractive indices of 1 and 2. Illustrative results obtained with the two-flux method demonstrate the effect of isotropic scattering coupled with changing the refractive index. For small absorption with large scattering the maximum layer temperature is increased when the refractive index is increased. For larger absorption the effect is opposite, and the maximum temperature decreases with increased refractive index .
A Little Bit More Evidence of Lottery Regressivity: The Kansas State Lottery

This paper examines the existence of regressivity at the Kansas State Lottery using county level data. The classic “t-test” is used to test if the mean per capita bet in classes, defined as being below or above the median state income, are the same. The results show that the means of the per capita bets are not statistically different. Another test directly tests regressivity using the mean of bets expressed as a percentage of income. The results show that lower income counties bet more as a percentage of income. The second test also defines classes as being below or above the median educational level, labor force participation rate, employment rate, unemployment rate, population density, percentage white and the population size. The results show that Kansas runs a regressive lottery.
Synthesis and retrostructural analysis of libraries of AB3 and constitutional isomeric AB2 phenylpropyl ether-based supramolecular dendrimers.

We report the synthesis of methyl esters of 3-(4-hydroxyphenyl)propionic, 3-(3,4-dihydroxyphenyl)propionic, 3-(3,5-dihydroxyphenyl)propionic, and 3-(3,4,5-trihydroxyphenyl)propionic acids and their use in a convergent iterative strategy to prepare up to four generations of three libraries, one of 3,4,5- and two of constitutional isomeric 3,4- and 3,5-substituted 3-phenylpropyl dendrons. Each library contains 3-[3,4,5-tris(dodecyl-1-oxy)phenyl]propyl-, 3-[3,4-bis(dodecyl-1-oxy)phenyl]propyl-, 3-{3,4-bis[3-(4-dodecyl-1-oxyphenyl)propyl-1-oxy]phenyl}propyl-, and 3-{3,4,5-tris[3-(4-dodecyl-1-oxyphenyl)propyl-1-oxy]phenyl}propyl ether first-generation dendrons on their periphery and −CO2CH3, −COOH, and −CH2OH groups at their apex. Regardless of their generation number and their periphery, internal, and apex structures, these dendrons self-assemble into supramolecular dendrimers that self-organize into all periodic and quasi-periodic assemblies encountered previously and in several unencountered with architectu...
Quantifying Real-World Upper-Limb Activity in Nondisabled Adults and Adults With Chronic Stroke.

Background. Motor capability is commonly assessed inside the clinic, but motor performance in real-world settings (ie, outside of the clinic) is seldom assessed because measurement tools are lackin...
Idiopathic membranous glomerulopathy preceding the emergence of systemic lupus erythematosus in two children

An idiopathic nephrotic syndrome associated with membranous glomerulopathy antedated the subsequent emergence of systemic lupus erythematosus in two patients (7-year-old and 14-year-old girls). At the onset of INS, there was neither clinical evidence of multisystem disease nor unequivocal serologic evidence of SLE. The only early possible indication of SLE was the presence of microtubular inclusions in glomerular endothelial cells on electron microscopy. In each instance (one year and three years after onset of INS), a second renal biopsy showed transformation of the membranous glomerular lesion to a more florid type with glomerular subendothelial dense deposits. One patient died of overwhelming pulmonary infection while she was receiving prednisone and cyclophosphamide; the other developed progressive renal failure despite steroid treatment. SLE should be considered in patients presenting with apparent idiopathic MG, in whom nephrotic syndrome persists. Intraendothelial cell microtubular inclusions may be an early clue to later emergence of SLE.
2n or not 2n: Aneuploidy, polyploidy and chromosomal instability in primary and tumor cells

Mitotic defects leading to aneuploidy have been recognized as a hallmark of tumor cells for over 100 years. Current data indicate that ∼85% of human cancers have missegregated chromosomes to become aneuploid. Some maintain a stable aneuploid karyotype, while others consistently missegregate chromosomes over multiple divisions due to chromosomal instability (CIN). Both aneuploidy and CIN serve as markers of poor prognosis in diverse human cancers. Despite this, aneuploidy is generally incompatible with viability during development, and some aneuploid karyotypes cause a proliferative disadvantage in somatic cells. In vivo, the intentional introduction of aneuploidy can promote tumors, suppress them, or do neither. Here, we summarize current knowledge of the effects of aneuploidy and CIN on proliferation and cell death in nontransformed cells, as well as on tumor promotion, suppression, and prognosis.
Biomechanics: hydrodynamic function of the shark's tail.

The tail of most sharks has an elongated upper lobe that differs from the externally symmetrical tail structure common among bony fishes, but the hydrodynamic purpose of this asymmetric tail shape is unclear1,2,3. Here we quantify water flow patterns in the wakes of freely swimming dogfish sharks and find that they have a ring-within-a-ring vortex structure, in contrast to the single rings shed by symmetrical fish tails. The branched-ring vortex is generated by the inclined angle of the tail's trailing edge and by its motion at an angle to the horizontal body axis; the vortex directs water backwards and downwards, which may increase the shark's vertical manoeuvrability.
The Use of Insects as Tracers for “Clear-Air” Boundary-Layer Studies by Doppler Radar

Abstract Single- and multiple-Doppler radar systems are increasingly being used to monitor circulations within the clear-air boundary layer where the scatterers may be gradients of the refractive index or biota or a combination of both. When insects are the primary source of returned radar power, it must be assumed that the insects are either small and are being carried passively in the air, or are flying randomly so that the bulk velocity of all the insects contained within a pulse volume is zero relative to the air. This study presents dual-polarization radar observations of the interaction between a gust flow and a deep cloud of insects within a relatively unstable air mass over North Dakota on 4 July 1987. These data are unique in that they reveal several meteorological conditions for which the preceding assumption is not valid. The boundary layer was not capped, and circulations rose above an apparent threshold altitude above which these insects were not flying. Temperatures near the threshold altitu...
Abstract IA8: The interplay of inflammation and cancer.

Efficacious cancer immunotherapies will likely require combinations of strategies that enhance tumor antigen presentation and antagonize negative immune regulatory circuits. We demonstrated that vaccination with irradiated, autologous melanoma cells engineered to secrete GM-CSF followed by antibody blockade of CTLA-4 accomplishes clinically significant tumor destruction with minimal toxicity in a majority of stage IV metastatic melanoma and some advanced ovarian carcinoma patients. The detailed analysis of patients achieving sustained clinical benefits from these therapies illustrated the importance of a coordinated cellular and humoral anti-tumor immune response. Indeed, the extent of tumor necrosis in post-treatment biopsies was linearly related to the natural logarithm of the ratio of infiltrating CD8+ effector T cells to FoxP3+ Tregs. Moreover, therapy induced a potent antibody response to several key tumor cell surface and secreted proteins; these antibodies manifest functional activity in vitro, antagonizing tumor cell survival, invasive potential, and angiogenesis. Through an analysis of cytokine deficient mice, we delineated a critical role for GM-CSF in Treg homeostasis. GM-CSF is required for the expression of the phosphatidylserine binding protein MFG-E8 in antigen presenting cells, whereas the uptake of apoptotic cells by phagocyte-derived MFG-E8 maintains peripheral Treg activity. While blockade of MFG-E8 can enhance therapeutic immunity in the context of cancer vaccines, loss of Treg homeostasis with MFG-E8 deficiency can lead to chronic inflammation. Mice deficient in GM-CSF and IFN-γ develop at high frequency germinal center derived lymphomas and nonsmall cell lung carcinomas. The pathogenesis of these tumors reflects a combination of tumor-promoting inflammation and a loss of protective tumor immunity. Taken together, these findings highlight dual roles for immunity in cancer pathogenesis and therapy. Citation Format: Glenn Dranoff. The interplay of inflammation and cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr IA8.
Wireless, Remote-Query, and High Sensitivity Escherichia coli O157:H7 Biosensor Based on the Recognition Action of Concanavalin A

Escherichia coli O157:H7 is detected using a remote-query (wireless, passive) magnetoelastic sensor platform to which a 1 μm thick layer of Bayhydrol 110 and then a layer of functionalized mannose is applied. The multivalent binding of lectin concanavalin A (Con A) to the E. coli surface O-antigen and mannose favors the strong adhesion of E. coli to the mannose-modified magnetoelastic sensor; E. coli is rigidly and strongly attached on the mannose-modified sensor through Con A, which works as a bridge to bind E. coli to the mannose-modified sensor surface. As E. coli is bound to the sensor, its resonance frequency shifts, enabling quantification of E. coli concentration with a limit of detection of 60 cells/mL and a linear logarithmic response range of 6.0 × 101 to 6.1 × 109 cells/mL. The analysis can be directly conducted without incubation and completed in 3 h or less.
Some regularity properties of diffusion processes on abstract Wiener space

Abstract Diffusion processes on an abstract Wiener space are constructed from fundamental solutions of second-order parabolic equations with variable coefficients. The transition probabilities of such processes are compared with those of the Wiener process, and continuity of sample paths is established. Several operator semigroups associated with the processes are defined (one locally), and some regularity properties of these semigroups are established.
Recombinant α-interferon treatment of non-A, non-B (type C) hepatitis : review of studies and recommendations for treatment

Abstract Non-A, non-B (type C) hepatitis is a serious world problem which typically results in chronic hepatitis and may lead to cirrhosis and hepatocellular carcinoma. α-interferon has recently been studied in a number of randomized controlled trials throughout the world. The results of those studies are reviewed here. ALT levels were normalized by 2–3 MU recombinant interferon alfa-2b, three times per week s.c. for 6 months ( p
The U.S. Print Media and the Conventional Military Balance in Europe

Many analysts of the conventional military balance between NATO and Warsaw Pact forces in Europe argue that the U.S. press presents an unduly pessimistic picture of NATO's capability to withstand an invasion by Soviet-bloc conventional forces. This article seeks to substantiate and to explain this alleged incongruity between strategy experts and the American media.The first section presents the findings of a quantitative study of four influential publications over a three-year period. These findings indicate that the U.S. press does indeed underrepresent the more optimistic assessments of NATO's conventional military capability.The second section offers a twofold explanation for this phenomenon, arguing that the media's pessimism stems from the complexity of the issue and from the inherent advantages held by the conventional wisdom promulgated by self-interested U.S. government officials.
Visual factors in observational learning with rats

Albino rats learned to leverpress for food reinforcement through observation as quickly as hooded rats. Hooded rats, observing a trained rat through a screen, which reduced visibility, learned just as quickly as hooded rats which observed the trained rat through Plexiglas. Leverpressing was more quickly acquired by hooded rats that were shaped than hooded rats learning through observation. The results suggest that the contribution of visual observation to learning in rats is relatively minor and does not involve a high degree of visual acuity.
Coupling of cell structure to cell metabolism and function

The fact that cells make directed decisions regarding how to use energy, i.e., where to direct intracellular particles or where to move, suggests that energy can be, and is, harnessed in specific ways. It is now well established that the chemical reactions of the cell do not occur in nonorganized soup, but rather in the context of ordered structure. The physical components that make up this ordered structure of the cell are part of the tissue matrix, which consists of the dynamic linkages between the skeletal networks of the nucleus (the nuclear matrix), the cytoplasm (the cytoskeleton), and the extracellular environment (the extracellular matrix). To understand gene function and how the energy of the cell is directed towards accomplishing the tasks directed by DNA (gene expression), a further understanding of how cell structure is tied to cellular energy and function is required. We propose that the structural components of the cell harness cellular energy to direct cell functions by providing a dynamic bridge between thermodynamics and gene expression.
Identification of a dual‐specificity protein phosphatase that inactivates a MAP kinase from Arabidopsis

Mitogen-activated protein kinases (MAPKs) play a key role in plant responses to stress and pathogens. Activation and inactivation of MAPKs involve phosphorylation and dephosphorylation on both threonine and tyrosine residues in the kinase domain. Here we report the identification of an Arabidopsis gene encoding a dual-specificity protein phosphatase capable of hydrolysing both phosphoserine/threonine and phosphotyrosine in protein substrates. This enzyme, designated AtDsPTP1 (Arabidopsis thaliana dual-specificity protein tyrosine phosphatase), dephosphorylated and inactivated AtMPK4, a MAPK member from the same plant. Replacement of a highly conserved cysteine by serine abolished phosphatase activity of AtDsPTP1, indicating a conserved catalytic mechanism of dual-specificity protein phosphatases from all eukaryotes.
Novel excitonic transitions in n-type GaAs/AlGaAs quantum wells

Abstract We report on a novel peak, the F-line, observed in photoluminescence spectra of GaAs/AlGaAs quantum wells (QWs) with various donor layer positions and concentrations. The F-line is well-defined and red shifted by approximately 1.3 meV (dependent on the experimental conditions) relatively the free exciton (FE) in a 200 A wide QW. The F-line exhibits a strong magnetic field dependence. The enhanced intensity with increasing field is due to an increasing wave function overlap caused by the enhanced localization of the involved charge carriers. In accordance, the derived thermal activation energy for the F-line is magnetic field dependent. The F-line exhibits a diamagnetic shift as expected for an excitonic transition and splits into four components with increasing magnetic field. Another associated higher energy peak, the E-line, is observed preferably in the presence of a magnetic field, between the heavy hole- and light hole-FE in PL excitation spectra. The E-line also exhibits a striking magnetic field and temperature dependence. The observed properties of the F-line with a striking dependence on the excitation intensity, magnetic field and temperature are consistent with the observation of an exciton bound at the negatively charged D - donor state or a negatively charged X - exciton.
Expression, purification, crystallization and preliminary X-ray studies of Lactobacillus jensenii enolase. Corrigendum

Sequencing of the 16S rDNA from the Lactobacillus strain used as the source of the enolase gene used for the studies reported in the article by Harris et al. (2010 ▶) has shown that what was reported as Lactobacillus jensenii 25258 is in fact Lactobacillus gasseri 33323. Further studies of this crystallized enolase will properly attribute the enzyme to L. gasseri. We sincerely apologize for any confusion arising from this unfortunate error.
Regulation of cardiac angiotensin‐converting enzyme and angiotensin AT1 receptor gene expression in Npr1 gene‐disrupted mice

1. Understanding of the regulatory mechanisms of gene expression in the control of blood pressure and fluid volume is a key issue in cardiovascular medicine. Guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) signalling antagonizes the physiological and pathophysiological effects mediated by the renin-angiotensin-aldosterone system (RAAS) in the regulation of cardiovascular homeostasis. 2. The targeted-disruption of the Npr1 gene (coding for GC-A/PRA) leads to activation of the cardiac RAAS involved in the hypertrophic remodelling process, which influences cardiac size, expression of pro-inflammatory cytokine genes and the behaviour of various hypertrophy marker genes. The Npr1 gene-knockout (Npr1(-/-)) mice exhibit 35-40 mmHg higher systolic blood pressure and a significantly greater heart weight to bodyweight ratio than wild-type (Npr1(+/+)) mice. 3. The expression of both angiotensin-converting enzyme (ACE) and angiotensin II AT(1a) receptors are significantly increased in hearts from Npr1(-/-) mice compared with hearts from Npr1(+/+) mice. In parallel, the expression of interleukin-6 and tumour necrosis factor-alpha is also markedly increased in hearts from Npr1(-/-) mice. 4. These findings indicate that disruption of NPRA/cGMP signalling leads to augmented expression of the cardiac RAAS in conjunction with pro-inflammatory cytokines in Npr1-null mutant mice, which promotes the development of cardiac hypertrophy and remodelling.
Reliability Analysis of a Two-Unit Standby-Redundant System with Preventive Maintenance

We consider a standby-redundant model of two units, where we assume that one unit is operative and the other unit is in standby at time t = 0. If the operative unit fails, a unit in standby is put into preventive maintenance policy of the operative unit to maintain our the preventive maintenance policy of the operative unit to maintain our system with high reliability. Our concern for the system is the time to the first system-down. The Laplace-Stieltjes transform of the time distribution to the first system-down and the mean time to the first system-down are derived by applying the relationship between Markov renewal processes and signal flow graph. Further, the behavior after the system-down is investigated by using the results of Markov renewal processes. Finally, numerical examples are presented for the k-Erlang failure time distributions. The optimal preventive maintenance time is discussed.
Investigation of Color in the Cuisenaire Rods

To determine the value of color in the Cuisenaire rods 66 first and second graders were given treatments of teacher-presented lessons using either colored or uncolored rods. Tests of efficiency, ro...
Are past relationships at the heart of attachment dynamics? What love has to do with it.

The ways in which a sense of attachment security can be primed and the consequences that follow from this for self-, interpersonal, and intergroup perception are the subject of this insightful targ...
Developmental brain abnormalities in tuberous sclerosis complex: A comparative tissue analysis of cortical tubers and perituberal cortex

Summary Objective Genetic loss of Tsc1/Tsc2 function in tuberous sclerosis complex (TSC) results in altered mammalian target of rapamycin (mTOR) signaling and abnormal brain development. Although earlier studies have focused on characterization of cortical tubers, in this study we sought to examine the unique cellular and molecular features of the perituberal cortex in order to better understand its contribution to epileptogenesis, cognitive dysfunction, and autism. Methods Standard histologic and immunohistochemical labeling was used to assess structural abnormalities and cell-specific pattern of mTORC1 activation in surgically resected cortical tubers and perituberal cortex. Western blotting was performed to quantify the expression of the mTORC1 and mTORC2 biomarkers phospho-S6 (Ser235/236), phospho-S6 (Ser240/244), and phospho-Akt (Ser473), in addition to evaluating the differential expression levels of several neuronal and glial-specific proteins in tubers and peritubers, as compared to non-TSC epilepsy specimens. Results Tubers demonstrated mild to severe disruption of cortical lamination, the presence of pS6-positive dysplastic neurons and giant cells, an overall increase in mTORC1 and a decrease in mTORC2 activity, increased axonal connectivity and growth, and hypomyelination. Perituberal cortex presented similar histologic, immunohistochemical, and molecular features; however, they were overall milder. Axonal growth was specific for TSC and was negatively correlated with deficient myelination. Significance Our results show an extension of cellular dysplasia and dysregulated mTOR signaling in the perituberal tissue, and demonstrate for the first time aberrant connectivity in human TSC brain. This study provides new insights into the pathophysiology of neurologic dysfunction associated with TSC and supports the intrinsic epileptogenicity of normal-appearing perituberal cortex. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
Measurement of Trace Gas Fluxes over an Unfertilized Agricultural Field Using the Flux-gradient Technique

Trace gas fluxes exhibit extensive spatial and temporal variability that is dependent on a number of factors, including meteorology, ambient concentration, and emission source size. Previous studies have found that agricultural fertilization contributes to higher fluxes of certain gases. The magnitude of trace gas fluxes over unfertilized crops is still uncertain. In the present study, deposition of ammonia (NH), nitric acid (HNO), and sulfur dioxide (SO) was measured over unfertilized soybean using the flux-gradient technique. The eddy diffusivity was estimated from eddy covariance measurements of temperature fluxes, resulting in K of 0.64 ± 0.30 m s. Flux means and standard deviations were -0.14 ± 0.13, -0.22 ± 0.19, and -0.38 ± 0.54 μg m s for NH, HNO, and SO, respectively. Low concentrations of NH and HNO increased the relative uncertainties in the deposition velocities estimated from measured fluxes. This contributed to dissimilarities between deposition velocities estimated from the resistance analogy and deposition velocities estimated from fluxes. However, wet canopy conditions during the study may have led to an underestimation of deposition by the resistance analogy because the resistance method does not accurately describe the enhanced deposition rates that occur after dew formation. Quantification of vegetation characteristics, such as leaf wetness and apoplast chemistry, would be beneficial in future studies to more accurately determine stomatal resistance and its influence on fluxes.
Effects of various anions and cations on the release of four dehydrogenases from brain mitochondria by a non-ionic detergent.

Summary It has been found that a number of agents greatly affects the release by Triton-X-ioo of certain dehydrogenases from rabbit-brain mitochondria. The enzymes studied were DPN-dependent isocitrate dehydrogenase ( L s-isocitrate:DPN+ oxidoreductase (decarboxylating), EC 1.1.1.41) and TPN-dependent isocitrate dehydrogenase ( L s-isocitrate:TPN+ oxidoreductase (decarboxylating), EC 1.1.1.42), gluta-mate dehydrogenase ( L -glutamate:DPN+ (TPN+) oxidoreductase (deaminating), EC 1.4.1.3) and lipoamide dehydrogenase (DPNH:lipoamide oxidoreductase, EC 1.6.4.3). The effects of Triton X-100 on the morphology of the mitochondria were checked with the electron microscope. 1. The detergent was shown to disrupt the architecture of the mitochondria, leaving single and double membranes and amorphous material. 2. ATP, ADP, pyrophosphate, citrate and isocitrate enhanced release of the enzymes. DPN was less effective, and α-ketoglutarate, adenylic acid and adenosine were ineffective, as was EDTA. 3. K+ and Na+ (80 mM) enhanced release of both isocitrate dehydrogenases, but partially prevented release of glutamate dehydrogenase. Ca2+ and Mg2+ at 4–5 mM enhanced release of TPN-isocitrate dehydrogenase but inhibited that of DPN-isocitrate dehydrogenase and glutamate dehydrogenase. Mg2+ had little effect on the release of lipoamide dehydrogenase. 4. It is suggested that metal ions play a role in the binding of these four dehydrogenases to the mitochondria, but that the details of the attachments may be different in each case.
Electrical characterization of Schottky contacts to N-polar GaN

Abstract The Schottky barrier heights of several metals (Cu, Au, Pd, Ni, and Pt) to N-polar GaN were extracted using current–voltage and capacitance–voltage measurements. The dependence of barrier height on metal was found to vary linearly with the electronegativity of the metal as predicted by the metal-induced gap states (MIGS)-and-electronegativity model. However, the magnitude of the barrier heights are lower than those predicted by the MIGS model for GaN and lower than the experimentally measured barrier heights for Ga-polar GaN. It is likely that the polarization-induced charge at the N-polar GaN surface is responsible for the reduced barrier height.
Resource utilization in patients hospitalized with heart failure: Insights from a contemporary national hospital database

Background Heterogeneity of disease severity and clinical trajectory has been described among patients hospitalized with heart failure (HF). However, little is known about the variability in and contributors to costs associated with HF hospitalizations. We examined the distribution of costs associated with a HF diagnosis in a large contemporary hospital database. Methods Diagnosis and procedure codes were systematically used to identify primary inpatient HF admissions to hospitals participating in the PREMIER database 2004-2005. Average costs per day and division of costs among hospital departments were evaluated based on patient and hospitalization characteristics. Results Total number of hospitalizations was 278,214; 36% had a length of stay (LOS) >5 days. There was a clear association between type of intravenous therapy, LOS, inhospital mortality, and cost. For example, patients initiated on a single intravenous inotrope had a longer mean LOS (9.6 days), greater inhospital mortality rate (14.7%), and higher mean total cost ($18,411) than any other medical therapy administered during hospitalization. The single largest contributor to cost was room and board. Forty-six percent of hospitalizations with diagnosis-related group code 127 (n = 234,204) exceeded average Medicare reimbursement. Variables on admission associated with highest cost hospitalizations were age Conclusions Length of stay is the determinant of cost for HF hospitalizations. Use of vasoactive therapy is a marker for longer LOS, higher mortality, and greater costs. Improved reimbursement rates or improved therapeutic options that lessen LOS are required if the costs of HF care are to be minimized.
INTELLECTUM TIBI DABO …: THE FUNCTION OF FREE WILL IN THE LIBRO DE BUEN AMOR

There can be no doubt that at present a state of confusion exists with respect to Juan Ruiz’ position on the doctrine of free will versus determinism in the Libro de buen amor. Much of the confusion may be attributed to a conscientious effort on the part of some critics to employ parallels between the Libro and similar extracts from mediaeval Latin and classical theological sources whose format and content may support or substantiate inferences drawn previously by these scholars. In some cases the confusion results from a simple misunderstanding of well-known mediaeval attitudes from which Juan Ruiz is often capriciously exempted. In the first instance, the implications are, of course, that Juan Ruiz was familar with the intricacies of Christian philosophy and that he knowingly applied these mental gymnastics to his work under the impression that his audience would recognize and appreciate them. This approach, not unlike the recent typological studies we have seen on mediaeval drama, has some obvious draw...
Factors influencing the pattern of dopamine secretion in Tetrahymena pyriformis

Abstract Dopamine production and secretion by the unicellular eukaryote Tetrahymena pyriformis were examined through the use of high performance liquid chromatography (HPLC) with electrochemical detection and through labeling studies with radioactive precursors. Growing cultures maintained a steady state intracellular level of 1.6 ± 0.3 pmol dopamine/10 6 cells while secreting dopamine into the medium at a rate of 0.2–0.3 pmol/10 6 cells per min. Incorporation of [ 14 C]tyrosine and l -[ 3 H]dihydroxyphenylalanine (DOPA) into dopamine was most successful in a basal medium (1.3 mM Tris-HCl, 1 mM citric acid, and 1 mM Ca(OH) 2 , (pH 6.5)). A rapid conversion of added l -[ 3 H]DOPA into dopamine confirmed the dynamic pattern of dopamine synthesis and secretion first indicated by the quantitative chromatographic analyses. The intracellular concentration of dopamine dropped sharply after cells were resuspended in the basal medium at 10 6 cells/ml, so that by approx. 1 h after resuspension, dopamine dropped below the level detectable by HPLC (0.15 pmol/10 6 cells). Under these conditions, dopamine secretion continued at a high rate for some time, finally leading to a maximal extracellular concentration of 8.71 ± 1.73 pmol/ml by 1 h. At this concentration, the rate of secretion appears to match that of degradation. Pulse chase experiments confirmed the rapid 3urnover of intracellular dopamine. Approx. 90% of [ 3 H]dopamine and l -[ 3 H]DOPA disappeared from l -[ 3 H]DOPA-prelabeled cells during a 5 min chase, with approx. 50% of this being recovered as [ 3 H]dopamine in the cells' medium. Dopamine secretion could be increased by nearly 100-fold by adding high levels (15 nmol/ml) of l -DOPA to the medium. In contrast, NSD-1015, a potent inhibitor of dopamine synthesis, completely blocked dopamine production. 0.15 mM dibucaine and 0.02 mM reserpine reduced dopamine secretion by approx. 65% over a 25-min incubation, but 5 mM EGTA had no noticeable effect.
Intonation and Fundamental Frequency in Male-to-Female Transsexuals

Twenty speakers, diagnosed as male-to-female transsexuals, produced conversational recordings of speech and voice. The samples were submitted to perceptual evaluations and to acoustic analysis by m...
Recent investigations of mechanisms of chemically induced skin irritation in laboratory mice

The time course, dose response, components of inflammation, and involvement of putative mediators of inflammation in irritation induced by different chemicals was compared using a mouse ear swelling technique. Differences in time courses of inflammation produced by the irritants were not solely due to differences in rates of penetration. Changes in blood flow and permeability of vessels were phasic with different numbers of phases induced by different irritants. Effects of antagonists, synthesis, inhibitors, and depleting agents of putative inflammatory mediators on intensity of inflammation varied for different irritants. These studies demonstrate that all chemicals do not produce skin irritation by a common inflammatory pathway. J Invest Dermatol 88:24s—31s, 1987
Chemistry and optical properties of 4d and 5d transition metal compounds. II. synthesis and optical spectra of acetatopentammineruthenium(III) and pseudohalogenpentammineruthenium(III) compounds

Abstract A number of acidopentammineruthenium(III) compounds having C4v micro-symmetry about RuIII were prepared and characterized. Solution optical spectra below 50 kK were recorded, and charged-transfer, dd, and internal transitions were observed. Tetragonal spin-orbit components of the charge-transfer π(NCSe−) →(Ru(xz,yz) transitions are only weakly antibonding, on the basis of band widths, relative to the ground state Γ7t(2Et0. dd transitions are assigned to 2T1g, 2T2gb, and Eg. The latter are not split sufficiently to permit observation of ther C4v components. The observed spectrochemical series of L in [Ru(NH3)5L]Q is NH3>NCO−>OAc−>SCN−>SeCn− on the basis of the energy of the first dd band.
Extinction of premixed flames of practical liquid fuels: Experiments and simulations

Compared to those for gaseous fuels, fundamental flame studies for liquid fuels are less extensive. The reasons are the experimental difficulty in handling the liquid phase and the complexity of kinetics stemming from the structure of liquid fuel molecules. However, such fuels are important in power generation, transportation, and propulsion. In this investigation, a systematic study has been conducted on the extinction of mixtures of methanol, ethanol, n-heptane, and iso-octane with air. The experiments were performed in the counterflow configuration and the extinction strain rates were determined through the use of digital particle image velocimetry. The introduction of the liquid fuel into the air was achieved through a liquid fuel feeder. The liquid flow rates were determined through the use of a high-precision pump. The experiments were conducted at ambient pressure and temperature and the maximum achievable equivalence ratios were limited by the attendant vapor pressure of each liquid fuel. The experiments were numerically simulated using detailed descriptions of chemical kinetic and molecular transport. A number of kinetic mechanisms were tested against the experimentally determined extinction strain rates. The mechanisms were also tested against literature data of laminar flame speeds. It was found that while most mechanisms satisfactorily predict laminar flame speeds, the experimental and predicted extinction strain rates can differ by factors of as much as 2 to 3. Under certain conditions, distinct differences were identified in the kinetic pathways that control the phenomena of propagation and extinction. Additionally, it was found that the sensitivity of laminar flame speeds and extinction strain rates to diffusion could be of the same order as that to kinetics.
In-flight radiometric calibration of Landsat-5 Thematic Mapper from 1984 to the present

The reflectance-based method is used to determine an absolute radiometric calibration of Landsat-5 Thematic Mapper for the solar reflective portion of the spectrum. Results are given for data collected at White Sands Missile Range in New Mexico on 1992-08-15. These results are compared to those obtained from applying a similar processing approach to data collected in 1984, 1985, 1987, and 1988.
Polymer fibers as optical device components

Single mode polymer optical fibers are promising candidates for all-optical devices because of fabrication flexibility, ability to tailor materials to meet a given application, and ease of fiber fabrication. In this paper, we discuss the fabrication process that is used to make single-mode polymer fibers and more complex fiber structures such as dual-core fibers. We also report on linear characterization studies of these fibers. In particular, we discuss refractive index profile measurements in both graded index and step index fiber preforms, dye concentration profiles, and waveguiding studies in dual-core optical fibers. Such linear-optical characterization is an essential input into the design of all-optical devices.
Freshwater aquatic macrophytes as heavy metal monitors - the Ottawa River experience.

The ability of freshwater aquatic vascular plants to accumulate heavy metals was examined in some detail during a five year study. Differences in uptake rate were found to depend on the species of plant, the seasonal growth rate changes and the metal ion being absorbed. Lead and mercury were concentrated to a greater extent than the lighter nickel and copper. Laboratory experiments were designed to establish uptake rate constants which were used to calculate water concentrations of mercury from the analyses of plant samples from the river. ‘Background’ levels of mercury in aquatic plants of 35–50 ng g-1 dry weight corresponded to a water concentration near 15 ng L-1 of total mercury of which 25–30% was methylmercury. Higher concentrations of mercury in the plants indicated a proportional increase in the mercury level in the water.
Aflatoxin is degraded at different temperatures and pH values by mycella of Aspergillus parasiticus

Blended 9-day-old mycelia of Aspergillus parasiticus NRRL 2999 were tested for their ability to degrade aflatoxins B1 and G1 at 7,19,28,36, and 45°C. Rates for degradation of aflatoxin B1 and G1 were maximum at 28°C. Intermediate rates of aflatoxin degradation were observed at 19 and 36°C while little aflatoxin was degraded at 7 and 45°C. Five different pH values (2.0, 3.0, 4.0, 5.0, and 6.5) were also tested to determine the effect of pH on ability of blended 9-day-old mycelia of A. parasiticus NRRL 2999 to degrade aflatoxins. The ability of mycelia to degrade aflatoxin was pH-dependent. Of the pH values tested, greatest rates of aflatoxin B1 and G1 degradation occurred when pH was in the range of 5 to 6.5. Little aflatoxin was degraded at pH 4.0 and essentially no aflatoxin was degraded by mycelia at pH 2.0 or 3.0 although some aflatoxin was degraded by acid conditions only at pH values of 4 or less.
Semiparametric analysis of non-steady-state pharmacodynamic data.

We present an approach to the analysis of pharmacodynamic (PD) data arising from non-steadystate experiments, meant to be used when only PD data, not pharmacokinetic (PK) data, are available. The approach allows estimation of the steady-state relationship between drug input and effect. The analysis is based on a model describing the time dependence of drug effect (E) on (unobserved) drug concentration (Ce) in an hypothetical effect compartment. The model consists of (i) a known model for the input rate of drug I(t), (ii) a parametric model; L(t, a) (a function of time t, and vector of parameters a), relating I to an observed variable X, (iii) a nonparametric model relating X to E. Ce is proportional to X. X(t) is given by I(X) * L(t, a)/AL, where L(t,α)=e −α 1 t * ∑ k=1 m , α2k e −α 2k+1 t, ∑ k=1 m α2k=1, AL=∫ 0 ∞ L(t) dt, and * indicates convolution.The nonparametric model relating X to Eis a cubic spline, a function of X and a vector of (linear) parameters β. The values of α and β are chosen to minimize the sum of squared residuals between predicted and observed E. We also describe a similar model, generalizing a previously described one, to analyze PK/PD data. Applications of the approach to different drug-effect relationships (verapamil-PR interval, hydroxazine-wheal and flare, flecainide and/or verapamil-PR, and left ventricular ejection fraction) are reported.
The Effects of Dream Sharing on Marital Intimacy and Satisfaction

ABSTRACT Dream sharing between partners, coupled with self-disclosure training, was empirically investigated as a means for generating intimacy and satisfaction among 216 participants who were randomly assigned to one of three groups: dream sharing, event sharing, and waiting list controls. Both dream sharing and event sharing participants attended a four hour self-disclosure training workshop and received an intimacy building workbook. Dream sharing in the context of this study supported the contentions of contemporary therapists that sharing dreams may enhance relationships while providing a forum for self-awareness and self-disclosure.
Dynamic simulation of software workers and task completion

As more and more companies are trying to leverage crowd sourcing to reduce cost and time-to-market of software production, it is very important to better understand the dynamics of crowd sourced software development in order to fully realize its benefits and avoid hidden pitfalls. This paper presents a systems dynamic model for crowd sourced software development platforms based on data gathered from Top coder. The model is composed of three components: the worker sub-model, the task sub-model, and the interactions between the two sub-models. Results of simulations are compared with empirical data gathered from Top coder for validation. The major simulation results indicate that task uploading and software workers arrival in the platform follow typical exponential patterns, incentivizing the crowd developers to become more active will lead to more tasks completion and success, and tasks associated with higher awards generally receive few submissions.