cssi/SciSciGPT-SciSciNet huggingface dataset:
PET imaging of dopamine D2 receptors with [18F]fluoroclebopride in monkeys: effects of isoflurane- and ketamine-induced anesthesia.

The purpose of the present study was to determine whether positron emission tomography (PET) studies in monkeys with the dopamine (DA) D2 receptor ligand [18F]fluoroclebopride (FCP) would be significantly influenced by anesthetic induction with isoflurane (∼5.0%) compared to induction with 10 mg/kg ketamine. Five experimentally-naive adult male cynomolgus monkeys (Macaca fascicularis) were trained to sit calmly in a primate restraint chair. Before the first PET scan, each monkey was anesthetized, by mask, with isoflurane. After complete sedation, the monkey was intubated and anesthesia was maintained throughout the PET study by isoflurane (∼1.5%). At least 1 month later, a second PET study was conducted in which anesthesia was induced with ketamine and maintained by isoflurane (∼1.5%). Irrespective of induction anesthetic, there was a high uptake of [18F]FCP and a linear rate of washout from the basal ganglia for all monkeys. There were also no differences in time to peak uptake (∼25 min), in clearance half-life (t1/2 = 140–164 min) or in D2 binding (distribution volume ratios of 2.48 vs. 2.50). These results indicate that induction anesthetic did not differentially affect D2 binding of [18F]FCP in monkeys. Furthermore, the low variability between studies indicates that [18F]FCP is an excellent ligand for longitudinal studies of D2 receptors in nonhuman primates.
Microstructural Diffusion Tensor Imaging Reveals Perforant Path Degradation in Aged Humans in vivo

over all ventricular voxels and converting this to percentage change using a calibration factor computed from the displacement yielded by a known ventricular volume change (Smith et al. NeuroImage 2002). Both processes were executed symmetrically to ensure unbiased results. Results: Data were obtained from 22 centers using scanners from 3 manufacturers and 2 field strengths. Compared to the truth, which should be 0 (see Figure), the mean (SD) of the absolute cGMtc was 0.34% (0.32%) using the longitudinal method, and 1.1% (0.72%) using the difference of cross-sectional measures. The absolute VVc was 0.27% (0.17%) using the longitudinal method, and 1.96% (1.20) using the cross-sectional differences. Conclusions: The mean absolute errors for our longitudinal measures were 1/3 that of the difference of cross-sectional measurements for cGMtc, and less than 1/7 for VVc. These results demonstrate the enhanced precision of our longitudinal measures over repeated cross-sectional measures, and suggest that the additional cost and complexity of phantom correction is not necessary.
The effects of secobarbital and dextroamphetamine upon time judgment: intersensory factors.

One hundred and sixty subjects judged the duration of short lights and sounds along 9-category response scales with no drug, a placebo, 200 mg secobarbital, or 15 mg dextroamphetamine. Measures of average category response and intrasubject response variability were obtained from single stimuli judgments of blocks of alternately presented auditory and visual signals using two temporal standards (i.e., social and subjective) 30, 60, and 90 min post-drug. The experiment produced main effects of and interactions among six factors: 1. Four drug conditions; 2. two sense modes; 3. two sense mode orders; 4. two temporal standards; 5. seven durations; 6. three post-drug trials.
THE AFFECTIVE AND COGNITIVE CONTEXT OF SELF REPORTED MEASURES OF SUBJECTIVE. WELL - BEING

Researchers attempting to understand the experience of subjective well-being have relied heavily on self-report measurement. Recent research focused on this method has demonstrated that a number of factors, such as the current mood of the respondent and the cognitive and social context surrounding the response, can significantly influence response to items inquiring about global subjective well-being or satisfaction with life. In the present study, several measurement strategies (e.g., single-item measures, multiple-item scales, and memory search tasks) were compared with regard to their susceptibility to such influences. Although some evidence for effects due to item-placement or transient mood were found, all of the global measures of subjective well-being and life satisfaction has significant convergence with peer-reports, and the single-item measures showed good temporal reliability across a one-month interval. The data provide evidence for a significant degree of stability in subjective well-being and life satisfaction.
Binding of the Neurotoxin DIIODO-Philanthotoxin343 (I2-PhTX-343) to Lipid Vesicles

AbstractThe binding of the glutamate and nicotinic acetylcholine receptor antagonist, I2-PhTX-343, to lipid vesicles was measured by NMR transverse relaxation as a function of I2-PhTX-343 concentration. The dissociation constants, found to be in the low millimolar range, varied with the composition and preparation of the liposomes. The binding of I2-PhTX-343 to liposomes was confirmed by nuclear Overhauser enhancement difference experiments. These results suggest that part of the I2-PhTX-343 molecule partitions into the hydrophobic interior of the liposome.
No Visible Means of Support: Child Labor in Urban Northeast Brazil

Child labor is one of the exigencies of life in poor households and a major aspect of the informal labor sector in urban Northeast Brazil. This article examines how a depressed local economy, extensive adult unemployment, economic niches available to children, and a general surplus of cheap labor reinforce a market for child labor. In poor households the loss of a child's earnings can lead to the disintegration of the household and be potentially life threatening as savings, assets, credit, and health plans are nonexistent. Households access and manage resources by minimizing consumption by children at home while increasing the number of hours children work and consume outside the home. In a context of scarce resources, limited choices, and financial uncertainty, the necessity for immediate income obliterates the luxury of waiting for a return on investments in education. This article further documents how the meaning given to children's work is mediated by economic niche, income-earning capacity, gender,...
Comparing a three-dimensional and a Dupuit-Forchheimer solution for a circular recharge area in a confined aquifer

Abstract An exact, closed-form analytic solution is presented for three-dimensional steady-state flow due to a source disc. The solution is used to model a circular recharge area at the upper boundary of a confined aquifer. Streamlines and contour plots of equipotentials are compared with those obtained from a Dupuit-Forchheimer solution. The latter solution is approximate in that resistance to vertical flow is ignored. As a further illustration a groundwater contamination problem is solved; that of a leaching circular pond in a uniform flow field. Some streamlines and the shape of the downstream plume are plotted for both the three-dimensional and the Dupuit-Forchheimer solution. It appears that when the recharge area is sufficiently large the Dupuit-Forchheimer solution is quite adequate, particularly when tracing streamlines. The results, therefore, confirm the validity of the Dupuit-Forchheimer assumption when modeling regional flow, even under circumstances of areal recharge. However, when the size of the recharge area is in the order of the aquifer thickness a truly three-dimensional solution is needed.
Observation effects on learning in horses

Abstract Sixteen horses, divided into 2 groups of 8, were used to study observational learning in horses. One group served as controls while the other group served as the treated group (observers). Observers were allowed to watch a correctly performed discrimination task for 5 days prior to testing their learning response using the same task. Discrimination testing was conducted on all horses daily for 14 days, with criterion set at 7 out of 8 responses correct with the last 5 consecutively correct. The maximum number of trials performed without reaching criterion was limited to 20 per day. Mean trials to criteria (MT) by group were: control, 11.25; observer, 10.70. Mean error (ME) scores were: control, 2.37; observer, 2.02. Average initial discrimination error scores were 11.13 for control and 10.38 for observers ( P P
Vitamin D Levels in Noninstitutionalized Children With Cerebral Palsy

Calcitriol (1,25-dihydroxy vitamin D) is an important hormone in calcium and phosphate metabolism. Levels of calcitriol and its precursor, 25-hydroxy vitamin D (calcidiol), were measured in a heterogeneous group of 125 noninstitutionalized children and adolescents with spastic cerebral palsy. Levels of each were correlated with: (1) clinical factors including mobility, prior fracture, and use of anticonvulsants; (2) nutrition and growth parameters including skinfolds, body mass index, and use of vitamin supplements; and (3) other serum analyses including osteocalcin as a marker of bone formation, calcium, and alkaline phosphatase. Levels of calcidiol and calcitriol did not correlate with any of the various clinical, nutritional, or growth parameters examined. The prevalence of low (< 10 ng/mL) levels of calcidiol was significant (19%), and dependent on the season of the year in which the level was measured. In contrast, less than 2% of the patients were found to have a low (< 20 pg/mL) level of calcitriol and the mean was comparable to normal pediatric subjects. Levels of calcitriol are maintained in noninstitutionalized children with cerebral palsy despite anticonvulsants, poor nutrition, and calcidiol levels that vary greatly with the seasons.
Employer Coverage of Clinical Preventive Services in the United States

Abstract Purpose. To characterize employers' coverage of clinical preventive services. Design. Mercer Human Resource Consulting Inc. included questions on clinical preventive services as part of its National Survey of Employer-Sponsored Health Plans, 2001. Setting. A national sample of employers of a large, medium, and small number of employees, including governments. Subjects. Respondents self-identified as most knowledgeable about the organization's health benefits. Measures. Weighted analyses of responses to eight survey questions on health promotion. Results. The survey was completed by 2180 employers, and the response rate was 21%. More than 90% of employers included increased productivity and decreased health care costs among their most important reasons for coverage of clinical preventive services. Within health insurance, coverage of physical examinations, immunizations, and screenings generally exceeded 50%, but coverage of lifestyle modification services was less than 20%. Only 20% of employers ...
Instruments for automatic test

Every engineer has used test instruments. From the humble handheld multimeter to the most complex protocol analyzer, test instruments are used by engineers in the field and the design lab, in repair shops and environmental chambers, in research, and in quality assurance (QA). Visit any electronics lab and you'll likely find arrays of instruments, stacked three high on lab benches, all of them familiar tools from familiar manufacturers. Walk down the hall from the lab to the test floor at a semiconductor manufacturer, a contract PC manufacturer, or even a military repair depot, and the familiarity falls away. Instead of multimeters, oscilloscopes, and precision voltage sources, you will find systems full of specialized instrumentation, often made by unfamiliar companies. The corridor between the design lab and the test floor seems to connect two different worlds. This discontinuity is not because the laws of electronics are different in the two worlds; it’s caused by the constraints bounding the test engineer. These constraints have required the creation of a different breed of test instrument, called automatic test equipment (ATE). The line between lab equipment and ATE isn't a sharp one but it's sometimes sharp enough to necessitate entirely different instrument designs. This article explores some of the general themes driving production instrument designs and gives some examples of the impact of production requirements on ATE design. The challenge for ATE designers is to cover all the boundary conditions while making sure that performance is always valued and cost effective.
An Effective Field Theory for One-dimensional Polarized Fermi Gases

We derive an effective field theory describing the long wavelength, low energy properties of one-dimensional (1D) attractive Fermi gases with spin imbalance. Our theory is based on the exact solution (Bethe ansatz) of the microscopic Hamiltonian, the Gaudin-Yang model. We show that the 1D Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state is a novel quantum fluid, a two-component Luttinger liquid with spin-charge mixing. Applying the theory, we obtain the correlation functions and the universal low temperature thermodynamics. Our theory can also predict the phase diagram of weakly coupled 1D gases, a quasi-1D system recently realized in experiments at Rice university.
Changing Clinical Practice through Research The Case of Delirium

Promoting application of study findings to the clinical setting is a constant challenge for nurse researchers. This project used change theory to include staff RNs in a research study on delirium and to use relevant findings. The research hypothesis was: Staff nurses who use a standardized protocol will have improved ability to identify delirium in elderly hospital patients. Staff nurses on the intervention unit used this protocol to screen for delirium on all consenting inpatients 75 years of age and over, and control unit nurses continued using their standard assessment practices. Intervention unit nurses demonstrated an improved ability to identify the presence and absence of delirium, and voluntarily requested to continue using the protocol after the study was terminated. Use of a theoretical model to include nurses in the study promoted the successful conduct of the research and subsequent use of findings.
Delineation of the hypothalamic area controlling thyrotropin secretion in the rat.

Discrete midline hypothalamic lesions were made in male rats in the region of the paraventricular nuclei (PVN), ventromedial nuclei, and medial preoptic area (mPO) using modified Halasz C-shaped knives. In euthyroid rats, small lesions, including the PVN and little surrounding tissue, or large lesions, including portions of the dorsomedial nucleus, anterior hypothalamus, and preoptic area in addition to the PVN, caused a similar 60% drop in the plasma TSH concentration within 2 days, which persisted for at least 3 weeks. PVN lesions also produced a significant decrease in plasma TSH in hypothyroid rats and diminished both the increase in plasma TSH in response to thyroidectomy and the decrease induced by ether inhalation. Ventromedial nuclei lesions preserving the PVN inconsistently decreased plasma TSH. mPO lesions anterior to the PVN induced a transient elevation of plasma TSH and GH only in hypothyroid rats. TRH-stimulated TSH secretion was not affected by any of the lesions. The results suggest: 1) th...
Mechanistic investigation of hydrolysis reactions of dithioacetal derivatives grafted on silica gels.

Abstract Silica gels believed to be grafted with dithioacetal derivatives were recently used for Hg(II) extraction, and were found to selectively remove 94–100% of Hg 2+ ions from metal ion mixtures. The current studies with one derivative suggest that the functional group in the Hg(II) removal is the mercapto (SH) ligand. The dithioacetal group in (ClCOCH 2 S) 2 CHPh ( 2 ) was hydrolyzed during its reaction with amine (O) 3 Si(CH 2 ) 3 NH 2 ( 3 ) grafted on silica gel to give the mercapto ligand (O) 3 Si(CH 2 ) 3 NHCOCH 2 SH ( 4 ). The silica gel grafted with the mercapto ligand 4 selectively removed Hg 2+ ions with reported high capacities.
Bayesian analysis of simulation-based models

a b s t r a c t Recent advancements in Bayesian modeling have allowed for likelihood-free posterior estimation. Such estimation techniques are crucial to the understanding of simulation-based models, whose likelihood functions may be difficult or even impossible to derive. One particular class of simulation-based models that have not yet benefited from the progression of Bayesian methods is the class of neurologically- plausible models of choice response time, in particular the Leaky, Competing Accumulator (LCA) model and the Feed-Forward Inhibition (FFI) model. These models are unique because their architecture was designed to embody actual neuronal properties such as inhibition, leakage, and competition. Currently, these models have not been formally compared by way of principled statistics such as the Bayes factor. Here, we use a recently developed algorithm - the probability density approximation method - to fit these models to empirical data consisting of a classic speed accuracy trade-off manipulation. Using this approach, we find some discrepancies between an assortment of model fit statistics. For some participants, one model appears to be superior when one fit statistic is used, while another appears superior when a different statistic is used. However, for 13 of the 20 participants, one model wins by all of the fit metrics considered. The FFI wins in 5 of these cases, while the LCA wins, often by a wide margin, for the others.
Differences in the pattern of attack of acidic, neutral, and basic phospholipases A2 of A. halys blomhofii on human erythrocyte membranes: Problems in interpretation of phospholipid location

Abstract Purified acidic (pI 4.9), neutral (pI 6.9), and basic (pI 8.7) phospholipase A2 from Agkistrodon halys blomhofii showed characteristically different patterns of hemolysis and phospholipid hydrolysis of intact human erthyrocytes. Acidic and neutral enzymes were nonlytic in the early periods of incubations with intact erythrocytes whereas the basic enzyme caused immediate hemolysis (5–8%). Under nonlytic conditions acidic and neutral enzymes hydrolyzed only phosphatidyl choline (PC) (20 and 50%, respectively), whereas basic enzyme hydrolyzed not only PC (60%) but nearly 15% of the phosphatidylethanolamine (PE). Both PC and PE were hydrolyzed significantly when the three phospholipases A2 were incubated individually with erythrocyte lysate or hypotonic ghosts (sealed or unsealed). The order of substrate preference for acidic and neutral enzymes was always PC > PE. On the contrary basic enzyme exhibited the property of substrate specificity reversal. It hydrolyzed PC faster than PE when the membranes were sealed whereas PE hydrolysis was faster than PC hydrolysis in unsealed membranes. Interestingly only the basic enzyme showed activity in the absence of Ca2+ and in the presence of 0.5 m m EDTA. Phospholipase C (Bacillus cereus or Clostridium perfringens) did not show the property of substrate specificity reversal although their ability to hydrolyze PC and PE was different. In general this study demonstrates the unique activity patterns of three physically different pure phospholipases A2 on human erythrocyte membranes which could be of value in selectively modifying membrane phospholipids. In addition it also throws an important light on the fact that results obtained with phospholipases should be interpreted with caution particularly as regards the localization of phospholipids in membranes.
Expression of multiple forms of an adhesive plaque protein in an individual mussel, Mytilus edulis

Individual blue mussels, Mytilus edulis L., can express at least 20 variants of a small protein known as M. edulis foot protein 3 or Mefp3. Mefp3 has been shown to be a component of the adhesive plaque of the byssus, the structure securing mussels to solid substrata. The cDNAs and deduced fp3 protein sequences display more variation at the carboxy-terminus than at the N-terminus, although there is some variation present throughout the protein. This indicates that there most likely are multiple copies of the gene encoding this protein. Each protein sequence contains a signal peptide, 24 to 25 residues in length, and a mature protein sequence of 44 to 54 residues. Gly is the most common amino acid in the mature protein at 20 to 25 mol%. Tyr and Arg follow closely at 20 to 23 and 16 to 21 mol%, respectively. Both of these amino acids were previously shown to be post-translationally modified to 3,4-dihydroxyphenylalanine (Dopa) and 4-hydroxyarginine, respectively, in this protein. MALDI-TOF (matrix-assisted laser desorption ionization with time-of-flight) mass spectrometric analysis of the underside of adhesive plaques reveals the presence of Mefp3-like proteins. Curiously, only four or five out of 20 possible fp3 variants are detectable in plaques deposited on glass or plastic. This would suggest that selection of protein variants for deposition onto surfaces is determined at the level of translation.
DETERMINATION OF THE FORMS OF CARBON IN GEOLOGIC MATERIALS

Total carbon was determined in 30 geological reference materials by combustion/IR and combustion/coulometry methods. The combustion/coulometric method does not require empirical calibration and was found to be more precise than the combustion/IR method despite the use of smaller sample sizes. Carbonate carbon was determined by coulometric titration of acid-evolved CO2. Non-carbonate carbon was calculated as the difference between the total and carbonate carbon contents.
Peer navigation in African American breast cancer survivors.

Purpose The purpose of this study was to explore the feasibility and acceptability of a peer navigation survivorship program for African American (AA) breast cancer survivors (BCS) and its potential effects on selected short-term outcomes according to the Quality of Life Model Applied to Cancer Survivors. Methods An AA BCS who completed treatment over 1 year prior to the study was trained as a peer navigator (PN), and then paired with AA women completing primary breast cancer treatment (n=4) for 2 months. This mixed-methods, proof of concept study utilized a convergent parallel approach to explore feasibility and investigate whether changes in scores are favorable using interviews and self-administered questionnaires. Results Results indicate that the PN intervention was acceptable by both PN and BCS, and was feasible in outcomes of recruitment, cost, and time requirements. Improvements in symptom distress, perceived support from God, and preparedness for recovery outcomes were observed over time. Qualitative analysis revealed six themes emerging from BCS interviews: "learning to ask the right questions", "start living life again", "shifting my perspective", "wanting to give back", "home visits are powerful", and "we both have a journey": support from someone who has been there. Conclusion Results support current literature indicating that AA women who have survived breast cancer can be an important source of support, knowledge, and motivation for those completing breast cancer treatment. Areas for future research include standardization of training and larger randomized trials of PN intervention. Implications for cancer survivors The transition from breast cancer patient to survivor is a period when there can be a loss of safety net concurrent with persistent support needs. AA cancer survivors can benefit from culturally tailored support and services after treatment for breast cancer. With further testing, this PN intervention may aid in decreasing general symptom distress and increase readiness for recovery post-treatment.
Preattentive and cognitive effects on perceptual completion at the blind spot

Our findings indicate that preattentive processes, such as the filling in of homogeneously colored areas, discrete dots, or bars across the blind spot, take into account both the color and the form that stimulate the retina around the optic disk. Perceptual completion of the “junction” of two opposite colors facing each other on opposite sides of the blind spot was resolved by simultaneous segregation of the two colors at the location of a filled-in perpendicular line that suggested a boundary separating the two colors. Orientation preference and relative salience of one color versus the other determined which color was perceptually completed in a forced-choice situation that involved perceptual completion at the intersection of a cross formed by bars of opposite colors. A 1-min exposure to these stimuli presented an ambiguous situation for perceptual completion of either color within the blind spot, and resulted in a perceptual “flip-flop” from one color to the other, much like the phenomenon that occurs in figure reversal. Instructions to speed up this reversal process led to a fivefold reduction in latency to first reversal.
CD154 Variant Lacking Tumor Necrosis Factor Homologous Domain Inhibits Cell Surface Expression of Wild-type Protein

X-linked hyper-IgM (XHIM) syndrome is an immunological disorder resulting from mutations in the CD154 gene. Some mutations occur in splicing sites and result in transcripts encoding wild-type and mutant proteins. These mutants lack the tumor necrosis factor homologous (TNFH) domain and consequently fail to trimerize. Given that the TNFH domain is responsible for trimerization, one may predict that the TNFH mutant can not participate in the assembly of wild-type CD154. Thus, it was puzzling why these patients exhibit XHIM phenotype, presumably resulting from a lack of functional CD154. One possibility is that the TNFH mutant exhibits a dominant negative effect over the wild-type protein. To investigate this, we coexpressed the wild-type protein and a TNFH mutant and examined the biochemical and functional properties of the resulting CD154 products. We demonstrate that despite the lack of the TNFH domain, the TNFH mutant can associate with the wild-type protein. Furthermore, such an association compromises the ability of the wild-type protein to mature onto the cell surface. These results provide a mechanism for the defect of CD154 in XHIM patients producing both wild-type and TNFH variants and suggest that besides the TNFH domain, the stalk region participates in the assembly of CD154 trimers.
Modelling temperature variation and thermal stratification in shallow aquaculture ponds

Abstract A mathematical model to stimulate thermal stratification in shallow aquaculture ponds is described. The dynamic, mechanistic model was developed to simulate the water column of ponds in discrete, completely mixed, horizontal volume elements. Energy exchanges between the pond's surface and atmosphere were calculated with theoretical and empirical relationships commonly applied to heat balance calculations in lakes, reservoirs and waste treatment ponds. Energy transfer between the volume elements caused by turbulent mixing were simulated as functions of the temperature gradient in the water column and a diffusion coefficient. The value of the diffusion coefficient was calculated in each time step as a function of wind speed, depth, and the water column density gradient. The model was implemented using a dynamics simulation language (STELLA™) using an Apple Macintosh™ microcomputer. Also described are the model calibration and verification procedure and results.
A note on helicity conservation in steady fluid flows

A theorem on helicity conservation proved by Moffatt (1969) for the flows of inviscid barotropic fluids is generalized, for steady flows, to any fluid in which vorticity field lines are material. To make this generalization, the helicity within a volume V enclosed by a material surface S must be defined by the volume integral,formula herewhere v is the fluid velocity, m is a unit vector tangent to a vorticity line, λ is the vorticity line stretch (Casey & Naghdi 1991), and J is the determinant of the deformation gradient tensor. For the case of an inviscid barotropic fluid, ([Hscr ]′S differs only by a constant factor from the helicity integral defined originally by Moffatt (1969). The condition under which ([Hscr ]′S is invariant under steady fluid motion is also the condition necessary and sufficient for the existence of a permanent system of surfaces on which both the stream lines and the vorticity lines lie (Sposito 1997). These surfaces and the helicity invariant ([Hscr ]′S figure importantly in the topological classification of integrable steady fluid flows, including flows with dissipation, in which vorticity lines are material.
Potentiating effect of murine interferon-γ-containing lymphokine preparations on the antiviral and antiproliferative effects of murine interferon-α/β: identification of the potentiation factor as murine interferon-γ itself

Abstract Mixed preparations of murine interferon-γ (MuIFN-γ) and murine interferon-α/β (MuIFN-α/β) have been shown to induce more than additive levels of antiviral protection, when compared to those induced by these interferons given separately. MuIFN-γ preparations contain many lymphokines and several of these as well as MuIFN-γ itself may participate in this potentiation. In the present study, natural as well as three recombinant DNA-derived MuIFN-γ's, in combination with antibody to MuIFN-γ have been employed to examine the precise role of MuIFN-γ. The antiviral effect was examined with a single cycle virus yield reduction assay and the antiproliferative effect with a colony formation inhibition assay. Recombinant DNA-derived MuIFN-γ was as effective as natural MuIFN-γ at participating in the potentiation of both the antiviral and antiproliferative activities. Antibody to MuIFN-γ effectively blocked the potentiation of both the antiviral and the antiproliferative activities of natural and recombinant DNA-derived MuIFN-γ's. Since the recombinant DNA-derived preparations from E. colie can be assumed not to contain mammalian proteins other than MuIFN-γ, the data conclusively demonstrate that the potentiation factor in MuIFN-γ preparations is MuIFN-γ itself.
Inhibition of renin release by vasopressin and angiotensin.

Vasopressin and angiotensin inhibited release of renin induced by lowered renal perfusion pressure. This action could not be related to a measurable haemodynamic change produced by either peptide; in some experiments with vasopressin there was no change in either systemic pressure or renal blood flow. The angiotensin analogues, angiotensin diamide and alanine7 angiotensin II, had no effects on arterial pressure, renal blood flow, or renin release; neither did mixtures of all of the amino acids present in the angiotensin molecule. Oxytocin did not affect renin release when infused in the same doses found to be effective for vasopressin.
Probing the free-energy surface for protein folding with single-molecule fluorescence spectroscopy

Protein folding is inherently a heterogeneous process because of the very large number of microscopic pathways that connect the myriad unfolded conformations to the unique conformation of the native structure. In a first step towards the long-range goal of describing the distribution of pathways experimentally, Forster resonance energy transfer1 (FRET) has been measured on single, freely diffusing molecules2,3,4. Here we use this method to determine properties of the free-energy surface for folding that have not been obtained from ensemble experiments. We show that single-molecule FRET measurements of a small cold-shock protein expose equilibrium collapse of the unfolded polypeptide and allow us to calculate limits on the polypeptide reconfiguration time. From these results, limits on the height of the free-energy barrier to folding are obtained that are consistent with a simple statistical mechanical model, but not with the barriers derived from simulations using molecular dynamics. Unlike the activation energy, the free-energy barrier includes the activation entropy and thus has been elusive to experimental determination for any kinetic process in solution.
The stranger, prudence, and trust in Hobbes's theory

In recent years, a number of interpreters of Hobbes's social and political theory have attempted to place it more firmly in its historical context, relating it not only to other theoretical developments, but also to changes in social and political structures.1 Despite their differences, the more recent interpreters have converged on several key points regarding Hobbes's place in seventeenth-century English history. Just as much recent historiography has moved away from interpreting the English Civil War or Glorious Revolution as bourgeois or capitalist revolutions,2 recent interpreters of Hobbes tend to criticize the picture of Hobbes as a bourgeois or capitalist theorist. They emphasize several features in place of this. The aristocracy did indeed decline in this period, and Hobbes was a critic of aristocratic virtue, in at least some sense of the term. But more importantly, this was a period of crisis for monarchical absolutism but of strengthening of the nation-state, and Hobbes was willing to accept either in principle as long as sovereignty was clear and undivided. And structures of political liberalism and religious toleration were importantly developed at this time, and Hobbes contributed to the theoretical defense of both perhaps paradoxically, given his absolutism.
Predisposed to toxins: association of gallbladder cancer with N-acetyl transferase SNPs.

Commentary to:Slow Acetylator Genotype of N-Acetyl Transferase2 (NAT2) is Associated with Increased Susceptibility to Gallbladder Cancer; The Cancer Risk Not Modulated by Gallstone DiseaseSachchida N. Pandey, Balraj Mittal, Gourdas Choudhuri and Dinesh R. Modi
Modelling the role of government policy in post-war Australian immigration.

The authors develop and estimate a model of post-war Australian migration which highlights an endogenous treatment of government policy and includes three equations explaining the emigration rate, the Government's Immigration Programme rate, and the immigration rate. The model permits the separate identification of long-run population growth influences vis-a-vis short-run economic considerations in explaining migration. Short-run labour market conditions are found to be more important in explaining government behaviour than are long-run population considerations. Immigrant behaviour appears to be affected by both short-run and long-run influences. Very little unexplained variation remains in the estimated regressions.
Photonic crystal defects with increased surface area for improved refractive index sensing

Photonic crystal cavities with tunable surface area via multiple-hole defects were investigated for increased resonance wavelength shifts upon exposure to variable-index analytes. Sensitivity was improved by 10% compared to simulated solid L3 cavities.
Reversible O-O bond cleavage in copper-dioxygen isomers: impact of anion basicity.

Low-temperature oxygenation of copper(I) complexes of N,N,N‘,N‘-tetraethylpropane-1,3-diamine yields solutions containing both μ-η2:η2-peroxodicopper(II) (P) and bis(μ-oxo)dicopper(III) (O) valence isomers. The P/O equilibrium position depends on the nature of the counteranion; P is favored with more basic anions. Titration and EXAFS experiments as well as DFT calculations suggest that axial donation from a sulfonate anion to the copper centers imparts an electronic/electrostatic bias toward the P isomer.
Computer-assisted techniques to evaluate fringe patterns

Strain measurement using interferometry requires an efficient way to extract the desired information from interferometric fringes. Availability of digital image processing systems makes it possible to use digital techniques for the analysis of fringes. In the past, there have been several developments in the area of one dimensional and two dimensional fringe analysis techniques, including the carrier fringe method (spatial heterodyning) and the phase stepping (quasi-heterodyning) technique. This paper presents some new developments in the area of two dimensional fringe analysis, including a phase stepping technique supplemented by the carrier fringe method and a two dimensional Fourier transform method to obtain the strain directly from the discontinuous phase contour map.
Effects of Stabilization of the gp41 Cytoplasmic Domain on Fusion Activity and Infectivity of SIVmac239

Abstract We investigated the effects of introducing specific sequences that are predicted to affect trimer stability into the CT domain of the SIV Env protein. Two constructs, 3HBai and 3HBaa, with additional GCN4-related sequences in the CT domain (45 aa) had enhanced infectivity, and differed in their fusion activity and trimer stability. Another construct, 3HBii, exhibited a very stable trimeric structure. Pseudotyped virions containing 3HBii retained infectivity despite the lack of syncytia formation. In contrast, 3HBai and 3HBaa, which caused extensive syncytia formation, had a less stable trimeric structure. We observed an inverse correlation between trimer stability and fusion activity but no correlation between syncytia formation activity and infectivity. Quantitative cell–cell fusion assays, analysis of Env incorporation, measurement of ectodomain conformation by CD4 binding, and CCR5 blocking assays indicated differential effects on fusion activity and infectivity of the viruses with Env CT modi...
Statistical broadening and population loss in strongly excited three-level systems

We study the effects of statistical broadening and population loss on the dynamics of strongly excited three-level quantum systems. The results of both analytic and numerical treatments of the three-level Schr\"odinger equation are displayed. In order to allow for statistical broadening, solutions are required for arbitrary detuning of the two very intense monochromatic lasers. The most efficient statistically averaged population depletion occurs when the Rabi frequency of the second transition is greater than that of the first.
The Pattern Visual-evoked Potential in Former Preterm Infants with Retinopathy of Prematurity

Purpose: Flash and pattern visual-evoked potentials (VEPs) were recorded in 89 former preterm infants (≤1500 g birth weight), in whom retinopathy of prematurity (ROP) developed that spontaneously regressed without macular detachment (stages 2–4a). Methods: Linear and stepwise regression analyses were performed to determine the correlations between transient pattern-reversal P 1 VEP latency (n = 154 eyes) at a mean of 7.2 years (median, 6.9 years) postnatal age using a check size nominally equivalent to 20/100 (30 minutes) and the following nine parameters: three immaturity parameters (gestational age at birth, birth weight, and ROP zone at 1 month postnatal age); one postnatal insults parameter (worst ROP stage); two structural outcome parameters (macular ectopia and vessel traction); one functional outcome parameter (visual acuity); and two methodological parameters (postnatal age at VEP testing and VEP amplitude). Results: Linear regression analyses, with P 1 VEP latency as a dependent variable, identified the worst ROP stage ( r = +0.42; P r = +0.42; P r = -0.40; P r = +0.35; P Conclusions: P 1 VEP latency correlates with postnatal insults, structural outcome, and functional outcome parameters in former preterms in whom ROP developed that spontaneously regressed without macular detachment. A permanent arrest in the development of the macula and/or prolonged traction on the incompletely developed macula may alter VEPs.
Work in progress — Rules of engagement: Student interest and learning in hands-on laboratory experiences

In order to evaluate the impact of hands-on experiences on student learning, the authors developed and delivered five one-hour supplemental learning sessions to a group of approximately 25 students over two consecutive years. During the sessions, student groups participated in a total of 16 hands-on activities, ranging in length from 5 to 20 minutes each. The primary objective of the activities was to emphasize concepts that students were learning about in a transport phenomena course. Pre- and post-testing indicated that during both years, the sessions helped students learn. In the second year, students were surveyed to attempt to elucidate causes for their engagement levels with the various activities. Student ratings of their interest in an activity and their perception of the learning value of an activity were usually positively correlated. Both student interest and student perception of learning values were positively correlated to improved scores from pre- to post-testing for activities.
Reaction–diffusion models of threshold and waveblock in heterogeneous excitable media

Abstract Nonlinear and linear reaction–diffusion equation models of heterogeneous excitable media are presented. These models include threshold, but no recovery. The linear model behaves in a similar manner to the nonlinear model under certain parameter constraints. It is shown that if a threshold stimulus is applied near the boundary of heterogeneities in excitability, waveblock and unidirectional propagation may occur. In this case, an excitation front propagates in one direction while propagation in the opposite direction is blocked. Waveblock corresponds to specific time-independent, nonhomogeneous steady state solutions of the models. These steady states are numerically and analytically investigated to determine the critical parameter values for which waveblock will occur.
Down-regulation of the GABA receptor subunits mRNA levels in mammalian cultured cortical neurons following chronic neurosteroid treatment

We have recently shown that chronic neurosteroid, 5α3α, treatment produced down-regulation of the GABA receptor binding and function, and heterologous uncoupling on the GABAA receptor complex in cultured mammalian cortical neurons. In order to explore the underlying mechanism of these observed down-regulation and heterologous uncoupling phenomenon, we investigated the effect of chronic 5α3α (1 μM; 5 days) treatment on the GABAA receptor subunits mRNA levels, using RNase protection assay. We found that chronic neurosteroid, 5α3α, treatment decreased the β- and α-subunits mRNA levels while not altering the γ2S-subunit mRNA levels in the cortical neurons. The decrease in the β-subunits mRNA levels suggests a decrease in the presence of the β-subunits in the composition of GABAA receptors. This phenomenon may explain the down-regulation of the GABAA receptor binding and function. A decrease in the α3-subunit mRNA level suggests a corresponding decrease in the α3-subunit in the composition of GABAA receptor isoforms, relative to other isoforms. This observation may be responsible for the chronic neurosteroid-induced uncoupling and decreased efficacy. In summary, chronic 5α3α treatment produced down-regulation of the GABAA receptor β- and α-subunit mRNA levels, and these changes may be associated with the down-regulation, heterologous uncoupling, and decreased efficacy of GABAA receptor complex in the cultured mammalian cortical neurons.
Particle-induced Phagocytic Cell Responses are Material Dependent: Foreign Body Giant Cells Vs. Osteoclasts from a Chick Chorioallantoic Membrane Particle-implantation Model

Abstract There is increasing concern about particles generated from wear-prone implants that are placed in body tissues, including artificial hip, knee, and jaw joints. Although phagocytes and foreign body giant cells are associated with inhaled or embedded particulate debris, some particles also induce bone digestion by eliciting the differentiation and proliferation of highly specialized osteoclastic cells. This report describes the differential phagocytic cellular responses to four implant-related types of ground, model wear particles in a live-egg cell-response model, as implants to the chick chorioallantoic membrane (CAM): polymethylmethacrylate (PMMA), a main constituent of some temporomandibular joint (TMJ) implants and orthopedic cements used to retain artificial hips and knees; Proplast-HA, an implantable composite of polytetrafluoroethylene (PTFE) and degradable mineral (hydroxyapatite) that has been associated with bone erosion around failed TMJ implants; talc, a nondegradable mineral sometimes...
Cortical Mechanisms Specific to Explicit Visual Object Recognition

The cortical mechanisms associated with conscious object recognition were studied using functional magnetic resonance imaging (fMRI). Participants were required to recognize pictures of masked objects that were presented very briefly, randomly and repeatedly. This design yielded a gradual accomplishment of successful recognition. Cortical activity in a ventrotemporal visual region was linearly correlated with perception of object identity. Therefore, although object recognition is rapid, awareness of an object's identity is not a discrete phenomenon but rather associated with gradually increasing cortical activity. Furthermore, the focus of the activity in the temporal cortex shifted anteriorly as subjects reported an increased knowledge regarding identity. The results presented here provide new insights into the processes underlying explicit object recognition, as well as the analysis that takes place immediately before and after recognition is possible.
The Structure of the Arabian Heat Low. Part II: Bulk Tropospheric Heat Budget and Implications

Abstract An investigation of the Arabian heat low is carried out based on observations from various satellites, an experimental aircraft and a surface energy budget monitoring station. The observations suggest that during the spring period the Arabian heat low is nearly radiatively neutral and lacks the properties of an energy sink characteristic of conventional desert heat lows. Satellite derived top-of-atmosphere radiation budget analyses illustrate the high contrast properties of the radiative exchange fields over the southern Arabian Peninsula with respect to its surroundings. However, an examination of a four-month time series of daily averaged net radiative exchange over the Arabian Empty Quarter, derived from Nimbus-7 Earth Radiation Budget (ERB) measurements, indicates that the heat low region is in slight relative excess. Combining these results with estimates of the surface energy budget inside the Arabian Empty Quarter (described in Part I), and previously estimated tropospheric radiative heati...
Soliton-Stripe Patterns of a Functional with an Attractive?Repulsive?Attractive Interaction

We study critical points of a Ginzburg–Landau type functional with an attractive–repulsive–attractive nonlocal interaction. Using an appropriate scaling and Γ-convergence method we reduce the problem to a finite dimensional one. In contrast to a similar problem with just an attractive–repulsive interaction, we obtain a richer set of solutions. The soliton-stripe patterns appear as skewed local minimizers of the free energy, and disappear or become symmetric as the number of interfaces reaches a certain threshold. We also show how other critical points can be constructed using results of the diblock copolymer problem.
The Social Dynamics of Mathematics Coursetaking in High School.

This study examines how high school boys’ and girls’ academic effort, in the form of math coursetaking, is influenced by members of their social contexts. The authors argue that adolescents’ social contexts are defined, in part, by clusters of students (termed “local positions”) who take courses that differentiate them from others. Using course transcript data from the recent Adolescent Health and Academic Achievement Study, the authors employ a new network algorithm to identify local positions in 78 high schools in the National Longitudinal Study of Adolescent Health. Incorporating the local positions into multilevel models of math coursetaking, the authors find that girls are highly responsive to the social norms in their local positions, which contributes to homogeneity within and heterogeneity between local positions.