cssi/SciSciGPT-SciSciNet huggingface dataset:
Dialkylsulfate formation in sulfuric acid-seeded secondary organic aerosol produced using an outdoor chamber under natural sunlight

Environmental context Laboratory and field studies have both provided evidence for organosulfate formation by esterification of H2SO4 with organic compounds in aerosols. Using an outdoor chamber, the production of dialkylsufate was measured for organic aerosols produced by photooxidation of various hydrocarbons in the presence of H2SO4 aerosol and NOx. The formation of organosulfates influences the decrease of both aerosol acidity and aerosol hygroscopicity. Abstract Secondary organic aerosols (SOA) were produced by the photooxidation of the volatile organic hydrocarbons (VOCs) isoprene, α-pinene and toluene, in the presence of excess amounts of sulfuric acid seed aerosol with varying NOx concentrations using a large, outdoor smog chamber. Aerosol acidity ([H+], μmol m–3) was measured using colorimetry integrated with a reflectance UV-visible spectrometer (C-RUV). The C-RUV technique measures aerosol acidity changes through the neutralisation of sulfuric acid with ammonia and the formation of dialkylsulfate, a diester of sulfuric acid. The concentration (μmol m–3) of dialkylsulfate in aerosol was estimated using the difference in [H+] obtained from C-RUV and particle-into-liquid-sampler ion chromatography (PILS-IC). The yield of dialkylsulfate (YdiOS) was defined as the dialkylsulfate concentration normalised by the concentrations of both the ammonium-free sulfate ([SO42–]free=[SO42–] – 0.5 [NH4+]) and organic carbon. The highest YdiOS appeared in isoprene SOA and the lowest YdiOS in α-pinene SOA. Under our experimental conditions, more than 50% of the total sulfates in sulfuric acid-seeded isoprene SOA were dialkylsulfates. For all SOA, higher YdiOS was observed under higher NOx conditions (VOC (ppb C)/NO (ppb)<15). Among the major functional groups (–COOH, –CO–H, –CHO and –ONO2) predicted to be present using a simple absorptive partitioning model of organic products in the multiphase system (gas, organic aerosol and inorganic aerosol), the concentrations of –CO–H, –CHO and –ONO2 groups were found to be correlated with YdiOS. In particular, a strong correlation was observed between YdiOS and the concentration of alcohol functional groups.
Biochemistry of Inorganic Bromide

As a constituent of thyroid hormones, iodine—the heaviest element metabolized in biological materials—plays a unique and essential role in mammalian biochemistry, and, accordingly, the vast majority of research dealing with inorganic iodide (I−) has been related to this role. The biochemistry of thyroid hormones is reviewed in Chapter 6, which includes an overview of the process by which I− is incorporated into thyroid hormones through bioiodination. In this chapter, the more general aspects of the biochemistry of I− will be considered, including occurrence, uptake, biodistribution, and metabolism of I−. Transport mechanisms, in particular, the mechanisms by which the thyroid gland concentrates I−, will be reviewed as will the interaction of I− with enzymes.
IL-2 induces Fas ligand/Fas (CD95L/CD95) cytotoxicity in CD8+ and CD4+ T lymphocyte clones.

IL-2 is a T cell growth factor that has pleiotropic functions in T cell differentiation, induction of lymphokine-activated killer cells, and regulation of immune responses. In studying TCR triggering of perforin or Fas ligand (FasL)/Fas (CD95 ligand/CD95) cytotoxicity in our influenza-specific T cell clones, we found that IL-2 can also induce FasL/Fas cytotoxicity. IL-2 induces FasL/Fas cytotoxicity in our CD8+ and CD4+ Th1 clones, but not in our CD4+ Th2 clones. IL-2 induction of cytolytic activity occurs when the CD8+ T cells are refractory to IL-2-induced proliferation. This killing is Ag independent, MHC unrestricted, and blocked by Fas.Fc fusion protein. IL-2 induces FasL/Fas cytotoxicity in a dose-dependent manner, but does not induce high levels of FasL expression as detected by flow cytometry. TCR triggered FasL/Fas cytotoxicity is detectable in CD8+ and Th1 clones by 3 h and peaks at 6 h; high levels of killing are maintained for at least 24 h. Similarly, IL-2 induces FasL/Fas killing in CD8+ and Th1 clones within 3 h of stimulation and maintains high levels for at least 24 h. TCR-triggered FasL/Fas killing is inhibited by emetine and cyclosporin A, whereas IL-2-induced FasL/Fas killing is inhibited by emetine, but not by cyclosporin A. These results demonstrate a second mechanism to induce FasL/Fas cytotoxicity in CD8+ and Th1 clones and may explain IL-2 induction of Ag-independent MHC-unrestricted lymphokine-activated killer cell activity.
Evaluation of consumer-style cooking methods for reduction of Escherichia coli O157:H7 in ground beef

The objective of this study was to evaluate the thermal inactivation of Escherichia coli O157:H7 in ground beef cooked to an internal temperature of 71.1 degrees C (160 degrees F) under conditions simulating consumer-style cooking methods. To compare a double-sided grill (DSG) with a single-sided grill (SSG), two different cooking methods were used for the SSG: for the one-turnover (OT-SSG) method, a patty was turned once when the internal temperature reached 40 degrees C, and for the multiturnover (MT-SSG) method, a patty was turned every 30 s. Patties (100 g, n = 9) inoculated with a five-strain mixture of E. coli O157: H7 at a concentration of 10(7) CFU/g were cooked until all three temperature readings (for two sides and the center) for a patty were 71.1 degrees C. The surviving E. coli O157:H7 cells were enumerated on sorbitol MacConkey (SMAC) agar and on phenol red agar base with 1% sorbitol (SPRAB). The order of the cooking methods with regard to the cooking time required for the patty to reach 71.1 degrees C was as follows: DSG (2.7 min) < MT-SSG (6.6 min) < OT-SSG (10.9 min). The more rapid, higher-temperature cooking method was more effective (P < 0.01) in destroying E. coli O157:H7 in ground beef. E. coli O157:H7 reduction levels were clearly differentiated among treatments as follows: OT-SSG (4.7 log10 CFU/g) < MT-SSG (5.6 log10 CFU/g) < DSG (6.9 log10 CFU/g). Significantly larger numbers of E. coil O157:H7 were observed on SPRAB than on SMAC agar. To confirm the safety of ground beef cooked to 71.1 degrees C, additional patties (100 g, n = 9) inoculated with lower concentrations of E. coli O157:H7 (10(3) to 10(4) CFU/g) were tested. The ground beef cooked by the OT-SSG method resulted in two (22%) of nine samples testing positive after enrichment, whereas no E. coli O157:H7 was found for samples cooked by the MT-SSG and DSG methods. Our findings suggest that consumers should be advised to either cook ground beef patties in a grill that cooks the top and the bottom of the patty at the same time or turn patties frequently (every 30 s) when cooking on a grill that cooks on only one side.
Cell Line Authentication Methods

In vitro cell culture systems are crucial research tools for discerning the complex mechanisms and pathways that regulate cell growth, differentiation and development. The validity of conclusions drawn from this research demands unequivocal verification of cell line identity. Keywords: DNA fingerprinting; cell line cross; contamination; mycoplasma detection; isoenzymology; cell culture
Building effective models from sparse but precise data: Application to an alloy cluster expansion model

A common approach in computational science is to use a set of highly precise but expensive calculations to parameterize a model that allows less precise but more rapid calculations on larger-scale systems. Least-squares fitting on a model that underfits the data is generally used for this purpose. For arbitrarily precise data free from statistic noise, e.g., ab initio calculations, we argue that it is more appropriate to begin with an ensemble of models that overfit the data. Within a Bayesian framework, a most likely model can be defined that incorporates physical knowledge, provides error estimates for systems not included in the fit, and reproduces the original data exactly. We apply this approach to obtain a cluster expansion model for the CaZr_(1−x)Ti_xO_3 solid solution.
Older Women, Fibromyalgia, and Exercise

Abstract In the year 2000, a paper was published in this journal that discussed the provision of physical activity for older people with fibromyalgia syndrome (FMS). Since then, much has been written and learned about this topic. In the paper that follows, new information is presented which can be helpful for activity directors when programming for exercise and physical activity for this ever growing, special segment of the elderly population.
Arachidonic acid and other free fatty acid changes during abortion induced by prostaglandin F2α

Abstract Serum free fatty acids (FFA's) were measured after intra-amniotic injection of prostaglandin F 2α (PGF 2α ) for the induction of abortion in eight healthy women in the midtrimester of pregnancy. The total FFA levels increased in all cases during the period between PGF 2α administration and abortion. This lipolysis most likely is secondary to the effect of the catecholamines as indicated by the temporal relationship between increased plasma and urine catecholamine and serum FFA levels. The percentage of arachidonic acid in the total amount of FFA's decreased after administration of PGF 2α . This proportional decrease in arachidonic acid (p
The Importance of Genome Architecture in Mental Retardation

Mental retardation (MR) has many different genetic causes, ranging from single gene to whole-chromosome changes. Some of the chromosomal changes underlying MR are recurrent submicroscopic deletions an
On-chip integrated differential optical microring refractive index sensing platform based on a laminar flow scheme

We propose an on-chip integrated differential optical microring refractive index sensing platform which leverages laminar flow conditions. Close spacing between a sensing and a reference resonator, and sharing the same microfluidic channel allows the two resonators to experience similar environmental disturbances, such as temperature fluctuations and fluidic-induced transients, achieving reliable and sensitive sensing performance. We obtain a noise floor of 80.0 MHz (0.3 pm) and a bulk refractive index sensitivity of 17.0 THz per refractive index unit (RIU) (64.2 nm/RIU), achieving a limit of detection of 1.4×10^(-5) RIU in a 30 min and an 8° C window.
Community signalling between Streptococcus gordonii and Porphyromonas gingivalis is controlled by the transcriptional regulator CdhR

Interspecies signalling between Porphyromonas gingivalis and Streptococcus gordonii serves to constrain development of dual species communities. Contact with S. gordonii propagates a tyrosine phosphorylation-dependent signal within P. gingivalis that culminates in reduced transcription of adhesin and signalling genes. Here we demonstrate the involvement of the P. gingivalis orphan LuxR family transcription factor PGN_1373, which we designate CdhR, in this control pathway. Expression of cdhR is elevated following contact with S. gordonii; however, regulation of cdhR did not occur in a mutant lacking the tyrosine phosphatase Ltp1, indicating that CdhR and Ltp1 are components of the same regulon. Contact between S. gordonii and a CdhR mutant resulted in increased transcription of mfa, encoding the subunit of the short fimbriae, along with higher levels of Mfa protein. Expression of luxS, encoding AI-2 synthase, was also increased in the cdhR mutant after contact with S. gordonii. The Mfa adhesive function and AI-2-dependent signalling participate in the formation and development of dual species communities, and consistent with this the cdhR mutant displayed elevated accumulation on a substratum of S. gordonii. Recombinant CdhR protein bound to upstream regulatory regions of both mfa and luxS, indicating that CdhR has a direct effect on gene expression. LuxS was also found to participate in a positive feedback loop that suppresses CdhR expression. Interaction of Mfa fimbriae with S. gordonii is necessary to initiate signalling through CdhR. These results reveal CdhR to be an effector molecule in a negative regulatory network that controls P. gingivalis-S. gordonii heterotypic communities.
A Comparison of the Effects of Thyrotrophin and Sodium Iodide on the Oxidation of Glucose-l-14C and the Levels of Triphosphopyridine Nucleotides in Thyroid Slices from Several Species

The comparative effects of sodium iodide and TSH, in vitro, upon the oxidation of glucose-l-14C and upon triphosphopyridine nucleotide levels in slices of dog, rat, beef and sheep thyroid glands are reported. While TSH increased glucose oxidation in all these species, Nal, in concentrations of 1 × lO-3M and 1 × 1O-4M, produced consistent and statistically significant stimulation only in sheep thyroid slices. In the sheep, the effect of Nal in Krebs-Ringer phosphate buffer was equivalent to that of TSH. The levels of TPN in dog and beef thyroid incubated in Krebs- Ringer bicarbonate buffer were increased when TSH was added to the medium, while the changes attributable to Nal were inconstant. In sheep thyroid slices the changes in TPN in the presence of both TSH and Nal were small and inconstant even in those experiments in which there was a clear-cut stimulation of glucose oxidation. It was concluded that the effect of TSH upon glucose oxidation in thyroid slices is not mediated by TSH-induced release of i...
NLSTT-MRAM: Robust spin transfer torque MRAM using non-local spin injection for write

In this work we propose a magnetic random access memory (MRAM) bit-cell design based on non-local spin transfer torque (NLSTT) [1–4]. In the proposed bit-cell, the data is written into the free layer of a magnetic tunnel junction (MTJ) using spin diffusion current (non-local spin injection), without injecting charge current into the tunneling oxide [1–4]. Thus, the reliability issues, related to dielectric breakdown due to high tunneling current density (for high switching speed) are significantly mitigated [5]. Separation of read and write current paths in the bit-cell helps in optimizing read and write separately. Hence, higher MgO thickness can be used for higher cell TMR and higher read disturb margin. Higher MTJ resistance resulting from thicker MgO also lets us use voltage mode sensing, that achieves higher speed for read operation. In the proposed bit-cell, we employ two supplementary spin injectors with tilted axis anisotropy, in order to compensate for the comparatively lower efficiency for non-local spin injection [3, 4]. Analysis of the proposed NLSTT-MRAM bit-cell is done using a physics based simulation framework, benchmarked with experimental data for lateral spin valve (LSV) [4, 5]. Apart from high reliability, the proposed bit-cell achieves 110% higher tunnel magneto resistance (TMR) and 4× higher read margin for 1ns switching speed as compared to standard 1-transistor-1 MTJ (1-T 1-R) STT-MRAM of similar area.
Are Young Children Logographic Readers and Spellers

According to many views of literacy development, prereaders use a logographic approach when they attempt to link print and speech. If so, these children should find pairs in which the spelling–pronunciation links are consistent with their writing system no easier to learn than arbitrary pairs. We tested this idea by comparing the ability of U.S. prereaders (M age = 4 years 9 months) to learn phonetically motivated pairs like AP–ape and MA–may and arbitrary pairs like OM–ape and PO–may. In both spelling and reading tasks, children learned the pairs with vowel letter name cues more easily than the arbitrary pairs. Phonetically motivated pairs were especially advantaged when the vowel letter names were at the beginning (e.g., AP–ape) rather than the end (MA–may). Prereaders who have some knowledge about letters, as U.S. preschoolers typically do, are not limited to a logographic approach in learning about print.
A Second-Order Magnetic Optical Achromat

A design procedure is given for the elimination of all of the second-order transverse geometric and chromatic aberrations in a particular class of staticmagnetic transport systems for charged-particle beams.
Droplet Size and Coalescence Stability of Whey Protein Stabilized Milkfat Peanut Oil Emulsions

Droplet diameter and the polydispersity of droplet size tended to decrease with increased proportion of peanut oil. Macromolecular additives affected droplet size. Xanthan gum or sodium carboxymethyl-cellulose (Na-CMC) produced smaller droplets than the controls, but the average diameter was independent of the composition of the dispersed phase. At 50°C the coalescence stability of these emulsions qualitatively correlated with the initial droplet diameter. Xanthan gum and Na-CMC, despite increasing continuous phase viscosity, gave lower stability than controls, primarily the result of flocculation of droplets due to depletion of the highly hydrophilic macromolecule from the intervening region between approaching droplets. At 25°C, stability increased as solid butter oil content of the dispersed phase increased.
Distribution of NADPH-d and nNOS-IR in the thoracolumbar and sacrococcygeal spinal cord of the guinea pig

Abstract The distribution of NADPH-d staining and neuronal nitric oxide synthase (nNOS)-immunoreactivity in the spinal cord of the guinea pig was studied to evaluate the potential role of nitric oxide in lumbosacral afferent and spinal autonomic pathways and to compare the distribution of these two markers to that observed in other species. NADPH-d staining and nNOS-immunoreactivity were present in neurons and fibers in the superficial dorsal horn, dorsal commissure and in neurons around the central canal in all levels of the spinal cord examined. Sympathetic preganglionic neurons in the thoracic and rostral lumbar segments identified by choline acetyl transferase (ChAT) immunoreactivity exhibited prominent NADPH-d staining and nNOS-immunoreactivity; whereas the ChAT-immunoreactive parasympathetic preganglionic neurons in the sacral segments were not stained. The most prominent NADPH-d staining in the sacral segments occurred in fibers extending from Lissauer's tract through laminae I along the lateral edge of the dorsal horn to the region of the sacral parasympathetic nucleus (lateral collateral pathway of Lissauer). These fibers were prominent in the S1–S3 segments but not in adjacent (L5–L7 and Cx1) or thoracolumbar segments. These NADPH-d fibers were, for the most part, not nNOS-immunoreactive, but did overlap with a prominent fiber bundle containing vasoactive intestinal polypeptide immunoreactivity in the sacral spinal cord. These results indicate that nitric oxide may function as a transmitter in thoracolumbar sympathetic preganglionic neurons, but not in sacral parasympathetic preganglionic neurons. Although the functional significance of the NADPH-d positive, nNOS-negative fiber bundle on the lateral edge of the sacral dorsal horn remains to be determined, this fiber tract may represent, in part, visceral afferent projections to the sacral parasympathetic nucleus.
Maternal Sensitivity and Anxiety: Impacts on Child Outcome

ABSTRACT Children of anxious parents have been shown to be at an increased risk of developing an anxiety disorder. Thus, it is critically important to identify factors that increase or decrease that risk. The depression literature has shown that maternal sensitivity decreases negative child outcome associated with maternal depression. The current study was designed to determine whether maternal sensitivity may buffer children of anxious mothers in a similar way. Three hypotheses were tested. First, that anxious mothers would display less sensitivity than nonanxious mothers in interactions with their children; that there would be an interaction between sensitivity and anxiety on child outcome; and that sensitivity would account for variance in child outcome beyond that attributed to anxiety. One hundred and twenty-five mothers (75 anxious) and their children (ages 3–12) completed the study. Mothers were administered the Anxiety Disorders Interview Schedule-IV and Parent, and a subset also completed the Bec...
Sponge dermal membrane morphology: Histology of cell‐mediated particle transport during skeletal growth

The keratose demosponge, Dysidea etheria, secretes a skeletal network of interconnecting spongin fibers and incorporates sand grains and other foreign particles into the fibers. Previous studies showed that foreign particles enhanced fiber growth and increased the stiffness of skeletal fibers. The present study uses light and electron microscopy to study the mechanism of particle incorporation. These histological observations show that particles become engulfed into thickened regions of the mesohyl of the dermal membrane, whereupon ameboid cells contact particles and secrete an electron dense layer of extracellular material onto the particle surface. Within several days, particles are moved towards primary skeletal fibers located at cone-shaped protuberances on the sponge surface called conules. Particles accumulate at conules and are consolidated by secretion of spongin at the growing fiber apices. The observations suggest that coordinated migration of groups of mesohyl cells control particle transport to conules and that patterns of cell migration are associated with the structural organization of the dermal membrane. Particle transport may be homologous and analogous to spicule transport in other demosponges.
Polarization Of Light In The Natural Environment

ABSTRACT This paper provides a characterization of the fields of light polarization with which the optical designer or user of optical devices in the natural environment must be concerned. After a brief historical outline of the principal developments in polarization theory and observations during the last two centuries, the main emphasis is on the two primary processes responsible for the polarization of light in nature- -scattering of light by particles of the atmosphere and reflection from soils, vegetation, snow, and water at the earth's surface. Finally, a seven minute film on polarization effects which can be seen in everyday surroundings will be shown.Scattering by atmospheric particles is responsible for high values of polarization in various atmospheric conditions and at certain scattering geometries. Such scattering particles include molecules of the atmospheric gases, aerosols of dust, haze, and air pollution, water droplets of fog and clouds, and the ice crystals of cirrus. It is seen that development of the theory of scattering by such particles has outstripped the measurements necessary for validation of the theory, a fact which points up the importance of symposia such as the present one. The reverse is true, however, for the polarizing properties of natural surfaces. Only in the case of still water is the theory of reflection adequate to characterize in a quantitative fashion the polarizing effects produced by the reflection of light from such natural surfaces. Polarization of light by reflection from vegetation is of prime importance in a remote sensing context, but much further work is needed to characterize vegetative reflectance for the purpose.The short film on polarization effects provides a good visualization technique and training aid for students interested in the field.
Dietary flavonols quercetin and kaempferol are ligands of the aryl hydrocarbon receptor that affect CYP1A1 transcription differentially

Transcriptional activation of the human CYP1A1 gene (coding for cytochrome P450 1A1) is mediated by the aryl hydrocarbon receptor (AhR). In the present study we have examined the effect of the common dietary polyphenolic compounds quercetin and kaempferol on the transcription of CYP1A1 and the function of the AhR in MCF-7 human breast cancer cells. Quercetin caused a time- and concentration-dependent increase in the amount of CYP1A1 mRNA and CYP1A1 enzyme activity in MCF-7 cells. The increase in CYP1A1 mRNA caused by quercetin was prevented by the transcription inhibitor actinomycin D. Quercetin also caused an increase in the transcription of a chloramphenicol reporter vector containing the CYP1A1 promoter. Quercetin failed to induce CYP1A1 enzyme activity in AhR-deficient MCF-7 cells. Gel retardation studies demonstrated that quercetin activated the ability of the AhR to bind to an oligonucleotide containing the xenobiotic-responsive element (XRE) of the CYP1A1 promoter. These results indicate that quercetin's effect is mediated by the AhR. Kaempferol did not affect CYP1A1 expression by itself but it inhibited the transcription of CYP1A1 induced by the prototypical AhR ligand 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD), as measured by a decrease in TCDD-induced CYP1A1 promoter-driven reporter vector activity, and CYP1A1 mRNA in cells. Kaempferol also abolished TCDD-induced XRE binding in a gel-shift assay. Both compounds were able to compete with TCDD for binding to a cytosolic extract of MCF-7 cells. Known ligands of the AhR are, for the most part, man-made compounds such as halogenated and polycyclic aromatic hydrocarbons. These results demonstrate that the dietary flavonols quercetin and kaempferol are natural, dietary ligands of the AhR that exert different effects on CYP1A1 transcription.
Human autoantibodies stabilize the quaternary structure of Ku antigen.

Objective. To examine humoral immune responses to the native Ku antigen and to evaluate the role of autoantibodies in stabilizing intermolecular contacts between the p70 and p80 Ku subunits. Methods. Recombinant free human p70 and p80 Ku subunits and p70/p80 heterodimers were expressed in Sf9 (insect) cells using baculovirus vectors. Affinity-purified recombinant human p70, p80, and p70/p80 dimer were studied by enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation to evaluate autoantibody specificities in sera from 58 patients with systemic autoimmune disease. Results. Anti-Ku antibodies were detected by ELISA or immunoprecipitation using K562 cell Ku antigen. All of the sera were reactive with the native recombinant p70, p80, or p70/p80 antigens: 47% were anti-p70+,anti-p80+ and 32% were anti-p70-,anti-p80+, but only 3% were anti-p70+,anti-p80-. Unexpectedly, 18% of the sera recognized the p70/p80 dimer but did not recognize native p70 or p80 alone. A subset of sera containing autoantibodies that prevent the dissociation of p70 from p80 by high salt and detergent treatment was identified; monoclonal antibody (MAb) 162, a murine anti-Ku MAb, displays the same property. Autoantibodies that stabilize the p70-p80 interaction were found most frequently in sera containing both anti-p70 and anti-p80 antibodies. Conclusion. Autoantibodies to the native p80 sub-unit of Ku are more common than are anti-p70 antibodies. When anti-p70 antibodies were detected, they generally were found together with anti-p80. A novel type of autoantibody capable of stabilizing the p70/p80 heterodimer was identified in human sera for the first time. These “stabilizing” autoantibodies are found in sera containing both anti-p70 and anti-p80 antibodies, and also are produced by mice immunized with human Ku antigen. Autoimmunity to Ku may be initiated with an immune response to p80, followed by spreading to p70. We hypothesize that stabilizing antibodies could facilitate the spreading of autoimmunity from one subunit of Ku to another by altering the processing of p70 or p80 by antigen-presenting cells.
Clinical Experience with Continuous Monitoring of Mixed Venous Oxygen Saturation in Respiratory Failure

The amount of oxygen in mixed venous blood (S v ¯ O 2 ) is a reliable indicator of the status of oxygenation of tissue in most clinical settings. Monitoring levels of S v ¯ O 2 might, therefore, aid in managing critically ill patients. A recently developed adult pulmonary arterial catheter provides continuous measurement of S v ¯ O 2 via fiberoptic bundles incorporated into the catheter, in addition to measuring hemodynamic pressures and cardiac output by thermodilution. We evaluated 100 consecutive fiberoptic catheters for accuracy and reliability of the system in 86 critically ill adult patients and determined the clinical usefulness that knowledge of S v ¯ O 2 provided. Over a range of hemoglobin saturations from 24 to 85 percent, the correlation coefficient between in vivo S v ¯ O 2 vs photometrically measured samples for 199 paired measurements was 0.95. Mean duration of usage for 33 catheters in the medical intensive care unit was 6.1 days; all catheters functioned normally until clinical conditions permitted removal. Continuous measurements of S v ¯ O 2 detected unsuspected increases in tissue oxygen consumption during coughing spasms and positioning of the patient. In nine of 13 patients with hypoxemic respiratory failure requiring positive end-expiratory pressure (PEEP), we found a strong correlation (r = 0.88) between oxygen delivery and S v ¯ O 2 . Of the four patients not showing correlation, two had sepsis, and two had nearly normal values of S v ¯ O 2 and oxygen delivery at all levels of PEEP studied. Continuous measurement of S v ¯ O 2 improves monitoring of patients, facilitates titration of respiratory therapies, detects abrupt changes in tissue oxygen consumption, and identifies levels of PEEP associated with greatest oxygen delivery.
Order parameter dynamics of body-scaled hysteresis and mode transitions in grasping behavior.

Several experimental studies have shown that human grasping behavior exhibits a transition from one-handed to two-handed grasping when to-be-grasped objects become larger and larger. The transition point depends on the relative size of objects measured in terms of human body-scales. Most strikingly, the transitions between the two different behavioral ‘modes’ of grasping exhibit hysteresis. That is, one-to-two hand transitions and two-to-one hand transitions occur at different relative object sizes when objects are scaled up or down in size. In our study we approach body-scaled hysteresis and mode transitions in grasping by exploiting the notion that human behavior in general results from self-organization and satisfies appropriately-defined order parameter equations. To this end, grasping transitions and grasping hysteresis are discussed from a theoretical perspective in analogy to cognitive processes defined by Haken’s neural network model for pattern recognition. In doing so, issues such as the exclusivity of grasping modes, biomechanical constraints, mode-mode interactions, single subject behavior and population behavior are explored.
Elevated intracranial pressure stimulates gastric contractility in the rat.

Abstract The gastric contractile response to elevated intracranial pressure (ICP) was studied in conscious rats. Elevation of intracranial pressure to 20 mm Hg was associated with a marked increase in the amplitude of gastric contractions (70–90% over baseline) without any change in contractile frequency (5.2 ± .5 contractions per min). The increase in contractility continued for 45 min following release of the pressure. Vagotomy completely blocked the increase in gastric contractility seen with elevation in ICP. We conclude that acute elevation of intracranial pressure in rats results in increased force of gastric contractions. The forceful contractions persist despite release of the pressure and the increased contractile force is vagally mediated.
Holographic interferometry study of an axisymmetric shock-wave/boundary-layer strong interaction flow

The results of a holographic interferometric and analytical examination of shock wave/turbulent boundary layer interactions occurring in a flow near a cone-cylinder intersection are reported. A Mach 2.85 flow with an Re of 18 million was used, along with cone angles of 12.5, 20 and 30 deg. Negligible, incipient and large scale separations were observed. The subsonic layer of the boundary always remained thin and was usually penetrated by the shock wave. An Abel transform, applied to the interferometric traces, yielded a great deal of data on the density field when combined with data from application of laser velocimeter, pressure tap and oil flow techniques.
The effect of synchronized inputs at the single neuron level

It is commonly assumed that temporal synchronization of excitatory synaptic inputs onto a single neuron increases its firing rate. We investigate here the role of synaptic synchronization for the leaky integrate-and-fire neuron as well as for a biophysically and anatomically detailed compartmental model of a cortical pyramidal cell. We find that if the number of excitatory inputs, N, is on the same order as the number of fully synchronized inputs necessary to trigger a single action potential, Nt, synchronization always increases the firing rate (for both constant and Poisson-distributed input). However, for large values of N compared to Nt, "overcrowding" occurs and temporal synchronization is detrimental to firing frequency. This behavior is caused by the conflicting influence of the low-pass nature of the passive dendritic membrane on the one hand and the refractory period on the other. If both temporal synchronization as well as the fraction of synchronized inputs (Murthy and Fetz 1993) is varied, synchronization is only advantageous if either N or the average input frequency, fin, are small enough.
Exact Prediction Error Variances for Full Model Computed from Reduced Model

Abstract The coefficient matrix for mixed model equations is often too large to invert for obtaining prediction error variances and for computing estimates of variances and covariances. Reduced, but equivalent, models can be written that have many fewer elements in the u vector than in the full model. The resulting reduced coefficient matrix can then be inverted in some cases. This paper presents a method for computing a g-inverse of the full coefficient matrix by a set of linear functions of a g-inverse for the reduced model. Two examples are presented, a nonadditive genetic model and an animal model.
C. elegans LIN-18 is a Ryk ortholog and functions in parallel to LIN-17/Frizzled in Wnt signaling

Wnt proteins are intercellular signals that regulate various aspects of animal development. In Caenorhabditis elegans, mutations in lin-17, a Frizzled-class Wnt receptor, and in lin-18 affect cell fate patterning in the P7.p vulval lineage. We found that lin-18 encodes a member of the Ryk/Derailed family of tyrosine kinase-related receptors, recently found to function as Wnt receptors. Members of this family have nonactive kinase domains. The LIN-18 kinase domain is dispensable for LIN-18 function, while the Wnt binding WIF domain is required. We also found that Wnt proteins LIN-44, MOM-2, and CWN-2 redundantly regulate P7.p patterning. Genetic interactions indicate that LIN-17 and LIN-18 function independently of each other in parallel pathways, and different ligands display different receptor specificities. Thus, two independent Wnt signaling pathways, one employing a Ryk receptor and the other a Frizzled receptor, function in parallel to regulate cell fate patterning in the C. elegans vulva.
An examination of physical education teacher motivation from a self-determination theoretical framework

Background: The motivation of physical education (PE) teachers has received precious little attention over the years. Self-determination theory (SDT) is a salient theoretical model for understanding motivation, and posits that self-determined motivation (i.e., intrinsic motivation) stems from the perceived fulfillment of three psychological needs: autonomy, competence, and relatedness. Scholars of SDT also contend that individual characteristics and contextual features can facilitate the fulfillment of these three needs. Therefore, SDT provides a useful theoretical platform for studying the relevant psychological needs and personal, professional and environmental features of PE teacher motivation. Aims: The primary purpose of this study was to examine whether physical educators' perceived fulfillment of autonomy, competence, and relatedness were related to their self-determined motivation. The second purpose of this study was to explore the potential impact of various personal, professional, and environme...
Factors Associated With Length of Hospitalization in Patients Admitted With Transient Ischemic Attack in United States

Background and Purpose—Approximately 70% of all patients presenting with transient ischemic attack are admitted to the hospital in United States. The duration and cost of hospitalization and associated factors are poorly understood. This article seeks to identify the proportion and determinants of prolonged hospitalization and to determine the impact on hospital charges using nationally representative data. Methods—We determined the national estimates of length of stay, mortality, and charges incurred in patients admitted with transient ischemic attack (diagnosis-related code 524 or 069) using Nationwide Inpatient Sample data from 2002 to 2010. Nationwide Inpatient Sample is the largest all-payer inpatient care database in the United States and contains data from ≈1000 hospitals, which is a 20% stratified sample of US community hospitals. All the variables pertaining to hospitalization were compared in 3 groups on the basis of length of hospital stay (≤1, 2–6, and ≥7 days). Results—A total of 949 558 pati...
Striving for failure: an industrial case study about test failure prediction

Software regression testing is an important, yet very costly, part of most major software projects. When regression tests run, any failures that are found help catch bugs early and smooth the future development work. The act of executing large numbers of tests takes significant resources that could, otherwise, be applied elsewhere. If tests could be accurately classified as likely to pass or fail prior to the run, it could save significant time while maintaining the benefits of early bug detection. In this paper, we present a case study to build a classifier for regression tests based on industrial software, Microsoft Dynamics AX. In this study, we examine the effectiveness of this classification as well as which aspects of the software are the most important in predicting regression test failures.
Diel periodicity of photosynthesis in marine phytoplankton

Short-term changes in photosynthesis were documented for 17 of 24 marine phytoplankton species, representing a range of taxonomic groups. Periodicity in phytoplankton photosynthesis on light-dark cycles (diel periodicity) was widespread but not universal for the species studied. The centric diatoms Lauderia borealis, Ditylum brightwellii, Stephanopyxis turris, Coscinodiscus rex, Chaetoceros gracile, and Biddulphia mobiliensis had strong diel periodicity in photosynthetic capacity (P max). Amplitudes of the daily variations ranged from 2.9 to >50, with maxima in the morning or near midday, and with minima during the dark period, and these variations were not dependent on changes in cell pigmentation. There was some evidence for sustained photosynthetic periodicity in constant conditions in several diatoms, and an endogenous rhythm may have been present. The photosynthesis-irradiance (P-I) relationship was time-dependent for representative marine diatoms, with both the initial slope (α) and the asymptote (P max) of P-I curves exhibiting significant synchronous diel oscillations. Moreover, detailed studies of the amplitude and timing of photosynthetic periodicity for the diatoms L. borealis and D. brightwellii demonstrated large temporal variations in photosynthesis with morning maxima. These P-I oscillations are discussed with reference to models of primary production which use the relationship between photosynthesis and light as a component of predictive equations for phytoplankton growth in the sea.
Internal state variable plasticity-damage modeling of the copper tee-shaped tube hydroforming process

Abstract This paper presents a parametric finite element analysis using a history-dependent internal state variable model for a hydroforming process. Experiments were performed for the internal state variable model correlation and for validating a 2-in. copper tee hydroforming process simulation. The material model constants were determined from uniaxial stress–strain responses obtained from tensile tests on the tube's material. In the finite element simulations, the mesh and boundary conditions were integrated with the geometry and process parameters currently used in industry. The study provides insights for the variation of different process parameters (velocity and pressure profiles, and bucking system characteristics) related to the finished product.
Impact of the selective estrogen receptor modulator, tamoxifen, on neuronal outgrowth and survival following toxic insults associated with aging and Alzheimer's disease

We investigated the estrogen agonist/antagonist properties of the selective estrogen receptor modulators (SERMs), tamoxifen (TMX) and 4-hydroxy-tamoxifen (OHT), using an in vitro neuron model system to determine the impact of the neuroprotective and neurotrophic properties of these SERMs. Low concentrations of TMX or OHT were without effect on a marker of neuronal viability, basal release of lactate dehydrogenase (LDH), whereas high concentrations of both SERMs (2500 ng/ml) induced a significant increase in LDH, indicating the potential toxicity of both SERMs at high concentrations. Subsequent experiments revealed that subtoxic concentrations of both TMX and OHT induced significant neuroprotection against beta-amyloid(25-35)-induced toxicity; 15-20% and 10-15% (P < 0.05), respectively and also against glutamate-induced toxicity; 25-30% and 20-40% (P < 0.05 and P < 0.01), respectively. Additional in vitro experiments included analysis of neuron survival to determine whether the SERM, OHT, acted competitively or synergistically with the endogenous estrogen, 17 beta-estradiol (E2). These revealed that neuron survival following exposure to the neurotoxins beta-amyloid and excitotoxic glutamate was significantly increased in cultures treated with OHT (50 ng/ml) (10%, P < 0.01) and that the magnitude of survival was equivalent to E2 (10 ng/ml). The combined presence of OHT and E2 significantly protected against both beta-amyloid(25-35) and excitotoxic glutamate-induced neuron death (10%, P < 0.01) but was not significantly different from either OHT or E2 alone. To assess neurotrophic effects of these same SERMs, cultured neurons from brain regions involved in memory function and Alzheimer's disease were evaluated by morphological analysis of individual neurons. Results of these analyses demonstrated that TMX treatment did not significantly increase the process outgrowth or morphological complexity of cortical, hippocampal, or basal forebrain neurons. Similar analyses showed that OHT also failed to significantly increase the neuronal outgrowth of either cortical or hippocampal neurons. Results of these studies predict that TMX and OHT could exert a neuroprotective function but would not promote estrogen-dependent memory function.
Electron spin-lattice relaxation mechanisms of rapidly-tumbling nitroxide radicals.

Abstract Electron spin relaxation times at 295 K were measured at frequencies between 250 MHz and 34 GHz for perdeuterated 2,2,6,6-tetramethyl-4-piperidone-1-oxyl (PDT) in five solvents with viscosities that result in tumbling correlation times, τR, between 4 and 50 ps and for three 14N/15N pairs of nitroxides in water with τR between 9 and 19 ps. To test the impact of structure on relaxation three additional nitroxides with τR between 10 and 26 ps were studied. In this fast tumbling regime T 2 - 1 ∼ T 1 - 1 at frequencies up to about 9 GHz. At 34 GHz T 2 - 1 > T 1 - 1 due to increased contributions to T 2 - 1 from incomplete motional averaging of g-anisotropy, and T 2 - 1 - T 1 - 1 is proportional to τR. The contribution to T 1 - 1 from spin rotation is independent of frequency and decreases as τR increases. Spin rotation dominates T 1 - 1 at 34 GHz for all τR studied, and at all frequencies studied for τR = 4 ps. The contribution to T 1 - 1 from modulation of nitrogen hyperfine anisotropy increases as frequency decreases and as τR increases; it dominates at low frequencies for τR > ∼15 ps. The contribution from modulation of g anisotropy is significant only at 34 GHz. Inclusion of a thermally-activated process was required to account for the observation that for most of the radicals, T 1 - 1 was smaller at 250 MHz than at 1–2 GHz. The significant 15N/14N isotope effect, the small H/D isotope effect, and the viscosity dependence of the magnitude of the contribution from the thermally-activated process suggest that it arises from intramolecular motions of the nitroxide ring that modulate the isotropic A values.
Comparing the Utility of the 2000 and 2005 Carnegie Classification Systems in Research on Students’ College Experiences and Outcomes

This study compares the explanatory power of the 2000 edition of Carnegie Classification, the 2005 revision of the classification, and selected variables underlying Carnegie’s expanded 2005 classification system using data from the National Survey of Student Engagement’s spring 2004 administration. Results indicate that the 2000 and 2005 classifications generally offer comparable explanatory power for measures of self-reported gains and student engagement, but the new variables from the 2005 system are more strongly related to cognitive outcomes and engagement than were the two categorical groupings. The variables most consistently related to outcomes and engagement are graduate-undergraduate coexistence, residential character of the campus, and arts and sciences share of undergraduate majors. Implications of the findings for research and assessment are discussed.
The WD40 domain is required for LRRK2 neurotoxicity.

Background Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of Parkinson disease (PD). LRRK2 contains an “enzymatic core” composed of GTPase and kinase domains that is flanked by leucine-rich repeat (LRR) and WD40 protein-protein interaction domains. While kinase activity and GTP-binding have both been implicated in LRRK2 neurotoxicity, the potential role of other LRRK2 domains has not been as extensively explored.
The chemical plausibility of dicyanamide as a primordial reactant.

Abstract Dicyanamide fulfills the requirements of stability and ease of synthesis initially set up for a reasonable primordial reactant. This is not to say that dicyanamide is the one and only solution to the problem of primordial polymerizations. Rather, these results substantiate the use of dicyanamide in studies designed to elucidate forces and phenomena which may have been instrumental and contributory in prebiotic chemical evolution.
Learning about reform: Time-varying support for structural adjustment

Abstract Political support for structural reforms can vary dramatically over time. Countries that have sustained reforms have seen their popularity grow, while others have witnessed sudden reversals of political support. Opinion can reverse itself, without any apparent provocation, when voters are learning about the effects of reform. In this model, structural adjustment causes a drop in government services and temporary unemployment. The unemployed gradually learn about when they will be re-employed. As labor markets adjust and the cost of reform is revealed, support can gradually rise, it can remain low and suddenly rise, or there can be a quick reversal of support for a previously popular policy. Cross-sectional data, event studies and case study support the explanation. Extensions consider international policies to maintain support for reform.
Numerical Methods for Nonlinear Differential Equations

New and better methods for the numerical solution of partial differential equations are being developed at an ever-in-creasing rate. In this paper, directed to scientists trained in mathematics but not necessarily in numerical analysis, we try to unify and simplify the underlying crucial points in this development. Most of the new methods can be understood and classified according to how space, time, and boundary conditions are discretized and by how nonlinear algebraic equations that arise in the solution process are solved. We will discuss each point and present numericalexamples showing how a simple linear analysis can fail.