cssi/SciSciGPT-SciSciNet huggingface dataset:
Photophysical properties of trans-platinum acetylide complexes featuring N-heterocyclic carbene ligands

A series of trans-N-heterocyclic carbene (NHC) platinum(ii) acetylide complexes of the form (ICy)2Pt(R)2 (where ICy = 1,3-bis-(cyclohexyl)imidazol-2-ylidene and R = 1-Ethynyl-4-(phenylethynyl)benzene (PE2), 2-(9,9-Diethyl-9H-fluoren-7-yl)benzo[d]thiazole (BTF), and 9,9-Diethyl-7-ethynyl-N,N-diphenyl-9H-fluoren-2-amine (DPAF), respectively), were synthesized via Hagihara reaction of the unprotected aryl-acetylide ligands with trans-(ICy)2PtCl2 () in 47-73% yield. Precursor was generated in a one-pot synthesis via formation of a silver carbene precursor followed by transmetallation, and was obtained in high yield (95%). The single-crystal X-ray structures of , were determined and analyzed. The photophysical properties of were compared to their respective tributyl phosphine (PBu3) analogues. The optical properties of the series were studied by UV-Vis spectroscopy, photoluminescence spectroscopy, nanosecond transient absorption spectroscopy, and open aperture nanosecond z-scan. Coupling of the organic chromophores to the platinum center affords efficient intersystem crossing as concluded by the complexes' low fluorescence quantum yields, efficient phosphorescence and intense T1 - Tn absorption. Open aperture z-scan with 606 nm, 10 ns laser pulses showed comparable optical attenuation relative to a standard sample of (PBu3)2Pt(DPAF)2 (). Pulse limiting was achieved via a dual-mechanism of two-photon absorption (2PA) coupled with excited-state absorption (ESA). TD-DFT Computations were also employed for to give greater insight into the nature of the singlet-singlet electronic transitions.
A novel requirement for C. elegans Alix/ALX-1 in RME-1-mediated membrane transport.

BACKGROUND: Alix/Bro1p family proteins have recently been identified as important components of multivesicular endosomes (MVEs) and are involved in the sorting of endocytosed integral membrane proteins, interacting with components of the ESCRT complex, the unconventional phospholipid LBPA, and other known endocytosis regulators. During infection, Alix can be co-opted by enveloped retroviruses, including HIV, providing an important function during virus budding from the plasma membrane. In addition, Alix is associated with the actin cytoskeleton and might regulate cytoskeletal dynamics. RESULTS: Here we demonstrate a novel physical interaction between the only apparent Alix/Bro1p family protein in C. elegans, ALX-1, and a key regulator of receptor recycling from endosomes to the plasma membrane, called RME-1. The analysis of alx-1 mutants indicates that ALX-1 is required for the endocytic recycling of specific basolateral cargo in the C. elegans intestine, a pathway previously defined by the analysis of rme-1 mutants. The expression of truncated human Alix in HeLa cells disrupts the recycling of major histocompatibility complex class I, a known Ehd1/RME-1-dependent transport step, suggesting the phylogenetic conservation of this function. We show that the interaction of ALX-1 with RME-1 in C. elegans, mediated by RME-1/YPSL and ALX-1/NPF motifs, is required for this recycling process. In the C. elegans intestine, ALX-1 localizes to both recycling endosomes and MVEs, but the ALX-1/RME-1 interaction appears to be dispensable for ALX-1 function in MVEs and/or late endosomes. CONCLUSIONS: This work provides the first demonstration of a requirement for an Alix/Bro1p family member in the endocytic recycling pathway in association with the recycling regulator RME-1.
Modeling of extremely low frequency magnetic field sources using multipole techniques

It is necessary to identify sources of magnetic fields in order to analyze shielding schemes. In general, it is difficult to specify actual sources. Here an alternative method to process magnetic field measurement data to create a simple model of a complex set of quasimagnetostatic sources is described. This method uses the maximum likelihood estimation technique to calculate the coefficients of spherical and finite length cylindrical multipole sources whose positions have been defined by the user. If a good fit to measured data is achieved, the simple model can then be used to provide input data required by a shielding analysis program.
Determination of Iron Colloid Size Distribution in the Presence of Suspended Cells: Application to Iron Deposition onto a Biofilm Surface

Abstract Transport and deposition of colloidal Fe, Mn and Al oxides play key roles in the cycling of toxic transition metals in aquatic environments because these colloids strongly bind transition metals. Further, attachment of biological cells and biofilm growth on surfaces can indirectly affect toxic metal distribution by influencing the deposition of colloidal oxides to surfaces. To elucidate the mechanisms governing these processes, deposition of colloidal oxides onto surfaces must be evaluated in the presence of suspended and adherent bacterial cells. Both particle size and concentration are expected to influence deposition. An experimental protocol was developed to determine the size distribution of iron colloids in mixtures with suspended cells. A Ti(III) reagent was used to reduce and dissolve colloidal Fe(III) from mixtures containing both suspended cells and Fe colloids. The size distribution of Fe(III) colloids in the original solution was then determined from the difference between size distributions before and after dissolution of Fe with Ti(III). The Ti(III) reagent dissolved over 95% of the Fe colloids without altering the size distribution of suspended bacterial cells, and the method accurately determined the size distribution of Fe colloids added to cell suspensions. The applicability of this protocol was tested by applying it to a study of the deposition of Fe(III) oxide particles onto glass surfaces with and without biofilms of the bacterium Burkholdaria cepacia 17616. Experimental results using a laboratory biofilm reactor indicated that the deposition rate of Fe(III) colloids was not significantly affected by the presence of B. cepacia biofilms or by the presence of previously deposited Fe. However, deposition of Fe to reactor surfaces other than the glass surfaces may have interfered with the analyses, and atomic absorption measurements showed a slight increase in Fe deposition onto glass surfaces with biofilms present. Fe deposition to the composite of all reactor surfaces increased with increasing colloidal particle size, indicating a dominance of interception and/or sedimentation in controlling Fe deposition on surfaces in the biofilm reactor.
A method to determine effective metamaterial properties based on stratified metafilms

Metamaterials' properties may be quantified through the assignment of bulk material parameters such as magnetic permeability and electric permittivity. These assignments rely on the assumption that metamaterials are effective media, in this context meaning that their electromagnetic properties are independent of the sample size. This assumption is not always valid, particularly for metafilms, the surface equivalents of metamaterials. However, metamaterials comprised of numerous metafilm and dielectric layers can be uniquely characterized in the effective medium approximation when all aspects of the metamaterial are properly integrated. We present a simple model based on stratified systems to illustrate this fact. The model further assists in the interpretation of novel metamaterial behaviors and offers a rapid and accurate method to determine the functionality of bulk metamaterial-based devices.
The SupraThermal Ion Monitor for space weather predictions

Measurement of suprathermal energy ions in the heliosphere has always been challenging because (1) these ions are situated in the energy regime only a few times higher than the solar wind plasma, where intensities are orders of magnitude higher and (2) ion energies are below or close to the threshold of state-of-art solid-state detectors. Suprathermal ions accelerated at coronal mass ejection-driven shocks propagate out ahead of the shocks. These shocks can cause geomagnetic storms in the Earth's magnetosphere that can affect spacecraft and ground-based power and communication systems. An instrument with sufficient sensitivity to measure these ions can be used to predict the arrival of the shocks and provide an advance warning for potentially geo-effective space weather. In this paper, we present a novel energy analyzer concept, the Suprathermal Ion Monitor (STIM) that is designed to measure suprathermal ions with high sensitivity. We show results from a laboratory prototype and demonstrate the feasibility of the concept. A list of key performances is given, as well as a discussion of various possible detectors at the back end. STIM is an ideal candidate for a future space weather monitor in orbit upstream of the near-earth environment, for example, around L1. A scaled-down version is suitable for a CubeSat mission. Such a platform allows proofing the concept and demonstrating its performance in the space environment.
Structure of molten iron chloride: Neutron scattering and modeling

Neutron-diffraction measurements of molten FeCl{sub 3}, combined with model calculations and computer simulations, show that on melting the local structure of Fe changes from an octahedral to a tetrahedral environment. A similar change is observed in AlCl{sub 3}, in contrast to YCl{sub 3}, for example, where the octahedral coordination of Y is preserved on melting. The local structure of the liquid can be described in terms of Fe{sub 2}Cl{sub 6} molecular units, similar to those observed in the vapor phase but with strong intermolecular interactions. Detailed information about the orientational correlations between molecules is derived from the simulations and compared with recent results on another molecular liquid, propylene glycol. {copyright} {ital 1998} {ital The American Physical Society}
Stochastic quantization of supersymmetric field theory

Abstract The Parisi-Wu stochastic quantization method is applied to supersymmetric field theory. The Langevin equation, which reproduces the Green functions of euclidean field theory, is written in terms of superfields. Supersymmetric U(1) theory under gauge fixing and the large N reduction in chiral SU( N ) theory are discussed. Regularization based on the stochastic method is studied also.
Λ and Σ hypernuclei

Abstract The present status of structure calculations for p-shell Λ hypernuclei, including the phenomenological determination of ΛN effective interaction matrix elements, is briefly reviewed. For Σ hypernuclei the Nijmegen potential model D is used for guidance in constructing ΣN effective interactions. The structure of Σ 12 Be and Σ 12 C, including isospin mixing in the latter case, is discussed, and a comparison is made with experimental data.
Alzheimer II astrocytosis following methionine sulfoximine.

A light microscopic study was performed during the preictal period following the administration of methionine sulfoximine (MSO) to adult rats. The principal morphologic observation was the development of Alzheimer II astrocytes in gray matter, suggesting that the metabolic abnormality induced by MSO is initially confined to the astrocyte. In view of the association of the Alzheimer II astrocyte with hyperammonemic states, the drug toxicity may be secondary to the presence of ammonia. A possible mechanism involves astrocytes in the development of seizures produced by MSO.
Free-radical polymerization at higher temperatures: Systems impacts of secondary reactions

Abstract This paper presents an evaluation of systems challenges in free-radical solution homo-polymerization as temperature increases. ‘Classical’ chain-polymerization kinetic models (accounting for initiation, propagation, chain transfer to solvent and monomer, and termination reactions) are unable to describe the dynamics of these processes. This inability is a consequence of the significant contributions of secondary (other) reactions, such as depropagation, self-initiation, β -scission, and inter/intra-molecular chain-transfer reactions, to the process dynamics. These secondary reactions have less significant influence on the polymerization at low temperatures. An application of high-temperature polymerization is in the production of lower average molecular weight, higher solid content resins. The quality of these resins is not characterized completely by measurements of solid content and average molecular weights alone. Advanced chromatographic and spectroscopic measurements of the concentrations of functional groups, terminal double bonds, chain branches and solvent groups, provide a fuller characterization of the polymer quality. Mathematical models describing these processes are of higher order and are more complex than their low-temperature counterparts. These processes are of lower degree of controllability, as a higher number of properties should be controlled (to achieve quality control) using the same number of manipulated inputs. For these same reasons, these processes have less degree of observability than their low-temperature counterparts, unless more advanced measurements are available.
Lectin-specific targeting of β-glucocerebrosidase to different liver cells via glycosylated liposomes

Galactosylated and mannosylated liposomes were more efficient in transporting liposome-entrapped β-glucocerebrosidase to liver compared to nonglycosylated liposomes. The enzyme entrapped to glycoside-bearing liposomes was found to be cleared at a much faster rate than that entrapped in liposomes having no sugar on their surface. Asialoorosomucoid and hydrolyzed mannan were found to inhibit both the clearance and the uptake of galactosylated and mannosylated liposomes, respectively, supporting involvement of lectin-sugar interaction. Further studies on the uptake of glucocerebrosidase by isolated liver cells revealed that the enzyme entrapped in mannosylated liposomes has much higher affinity for nonparenchymal cells whereas the assimilation of the entrapped enzyme into hepatocytes is clearly favored for liposomes having galactose on their surface.
Comparison of nanoparticle size and electrophoretic mobility measurements using a carbon-nanotube-based coulter counter, dynamic light scattering, transmission electron microscopy, and phase analysis light scattering.

The precision and accuracy of measurements of the diameter and electrophoretic mobility (μ) of polymeric nanoparticles is compared using four different analytical approaches: carbon-nanotube-based Coulter counting, dynamic light scattering (DLS), transmission electron microscopy (TEM), and phase analysis light scattering (PALS). Carbon-nanotube-based Coulter counters (CNCCs) use a 132 nm diameter channel to simultaneously determine the diameter (28−90 nm) and μ value for individual nanoparticles. These measurements are made without calibration of the CNCC and without labeling the sample. Moreover, because CNCCs measure the properties of individual particles, they provide true averages and polydispersities that are not convoluted into the intrinsic instrumental response function of the CNCC. CNCCs can be used to measure the size of individual nanoparticles dispersed in aqueous solutions, which contrasts with the TEM-measured size of individual dehydrated particles and the ensemble size averages of dispers...
A prospective randomized trial of the use of epidural anesthesia during external cephalic version.

Objective: To determine if the use of epidural anesthesia improves the success rate of external cephalic version (ECV).Design: Women identified with a singleton fetus in a breech or transverse presentation at a gestational age of >/=37 weeks gestation were offered enrollment in this prospective randomized trial. Inclusion criteria included maternal age of 18 years or older, a non-vertex presentation confirmed by ultrasound, a reactive fetal non-stress test, and an estimated fetal weight of 2,000-4,000 g. A 1:1 randomization was accomplished through a computer-generated random numbers table with group assignments sealed in sequentially numbered opaque envelopes. Women in the epidural ECV group had a lumbar epidural catheter inserted through which 2% lidocaine and 100 µg of fentanyl were infused.Results: There were no statistically significant differences between the two groups in gestational age at ECV, placental location, fetal lie, gravidity or parity, estimated fetal weight, or amniotic fluid index. The ECV was successful in 26 of 45 (58%) women with epidural anesthesia compared to 16 of 48 (33%) with no anesthesia (relative risk 1.7, 95% confidence interval 1.1-2.8, P <.05). Fetal bradycardia resulting in discontinuation of the version efforts occurred in two patients in the epidural group and three women in the control population, a non-statistically significant difference. There were no maternal complications noted in the study population related to the epidural anesthesia.Conclusions: The use of epidural anesthesia increases the success rate of external cephalic version.
Clinical predictors and consequences of atrial fibrillation after surgical myectomy for obstructive hypertrophic cardiomyopathy.

patients with ischemic heart disease. Acta Cardiol 1997;52:261–272. 5. Qi W, Kjekshus J, Hall C. Differential responses of plasma atrial and brain natriuretic peptides to acute alteration in atrial pressure in pigs. Scand J Clin Lab Invest 2000;60:55–63. 6. Yoshimura M, Mizuno Y, Harada E, Nakayama M, Shimasaki Y, Ito T, Nakamura S, Soejima H, Miyamoto S, Takazoe K, et al. Interaction on metabolic clearance between A-type and B-type natriuretic peptides in patients with heart failure. Metabolism 2000;49:1228–1233. 7. Ozaki J, Shimizu H, Hashimoto Y, Itoh H, Nakao K, Inui K. Enzymatic inactivation of major circulating forms of atrial and brain natriuretic peptides. Eur J Pharmacol 1999;370:307–312.
The effects of chronic ethanol challenges on aggressive responding in rats maintained on a semideprivation diet

A 2 by 3 factorial design was used to evaluate the effects of type of injection (saline vs. ethanol) and amount injected (.25 cc,.50 cc,.75 cc/100 g body weight) on shock-elicited aggression. All subjects were maintained on a restricted diet for the duration of the experiment. Intraperitoneal injections were administered to all subjects each day for 15 days. On the 15th day, each subject received shock-elicited aggression testing 15 min after the daily injection. The results indicated that the alcohol-injection subjects were significantly more aggressive than were the saline-injected subjects at the.25-cc level, but these subjects were significantly less aggressive at the.75-cc level.
Effects of oral sunflower oil and olive oil on serum and cutaneous fatty acid concentrations in dogs

Abstract The effects of dietary fatty acids on serum and cutaneous fatty acids of healthy dogs were evaluated under controlled conditions. Beagle puppies (n = 12) were fed a standard diet supplemented with sunflower oil (group A), olive oil (group B) or no supplementation (group C) for 12 weeks. There were no significant differences in food intake or growth rates between the three groups. Dogs in group A had significant increases (P
Covalent binding of suprofen acyl glucuronide to albumin in vitro

1. Suprofen acyl glucuronide, a major metabolite of suprofen in man, is labile, undergoing acyl migration to isomeric conjugates which are not cleaved by beta-glucuronidase. 2. The pH-dependent degradation of diastereomeric suprofen glucuronides in aqueous buffer increases rapidly near physiological pH with an apparent first-order half life of 1.4 h at pH 7.4. 3. Suprofen glucuronide and its isomeric conjugates are reactive with albumin in a pH-dependent manner which corresponds to the stability of the acyl glucuronide. Several per cent of the conjugates added to albumin in solution become covalently bound. 4. The covalent binding of suprofen equivalents to albumin is greatly enhanced by the addition of either cyanide or cyanoborohydride anion, which supports the presence of an imine in the process of binding. Release of isomeric conjugates by treatment of the albumin adduct with dilute acid also supports covalent binding via an imine. 5. The covalent binding of suprofen to proteins through its reactive acyl glucuronide may be of toxicological importance and relevant to the acute renal toxicity observed for suprofen in man.
Cerebrospinal fluid GABA in normals and patients with affective disorders

Cerebrospinal fluid GABA was measured in 41 normal volunteers, 16 depressed and eight manic patients during a medication-free evaluation. CSF GABA was measured by modified cation-exchange chromatography. Mean CSF GABA in the normal volunteers was 231.8 ± 12.5 pmole/ml, nonsignificantly different from that in the depressed patients (209.1 ± 13.8) or manics (211.4 ± 21.7). In one rapidly cylcing patient values during his manic episodes were significantly higher than those during depressed periods (p<0.05). In the normals CSF GABA was positively correlated (p<0.05) with CSF norepinephrine and MHPG and negatively correlated with CSF calcium and magnesium. In the depressed patients and in normal females, but not males, GABA was negatively correlated with age. There was no significant correlation between CSF GABA and degree or severity of rated depression, anxiety, or psychosis. Affectively ill patients treated with the anticonvulsant carbamazepine did not demonstrate significant alterations in CSF GABA concentrations.
Distributed scheduling of demand resources in a congested network

This paper proposes a distributed method to schedule supply and flexible demand in a congested network, accommodating diverse benefits of end-users. We look at two different time horizons to schedule supply and demand; a day ahead and an hour ahead, which we refer to as day-ahead and real-time clearing. For day-ahead clearing, we decompose the system-level problem and solve it in an iterative way to schedule supply and flexible demand over multiple time steps. However, after the day-ahead quantities are cleared and the actual consumption/production is to occur sooner, we use moving-horizon functional clearing. We show an application of this framework to the IEEE 30-bus test system with a large number of various air conditioning loads. The experiment shows effectiveness of the methods in managing congestion and in coping with unexpected conditions such as a rise in the weather temperature.
A study of heavy-ion beams during longitudinal compression using particle simulation

Abstract Particle simulations show that during longitudinal compression there is little growth in beam longitudinal and transverse emittance. Both longitudinal
Steps toward 8m honeycomb mirrors vi. Thermal control

Under the best atmospheric conditions mountain based telescopes have the potential to realize images with 0.25 arc second resolution. However, close thermal control of the observatory is needed to prevent local seeing from spoiling this quality. In particular it is very desirable to control the primary mirror surface temperature by removing heat from behind. In this paper we obtain expressions for the temperature of simple solid and honeycomb mirrors under a realistic observatory thermal environment and with different rates of heat removal. Heat transfer within a honeycomb structure by ventilation with air at ambient temperature is characterized by an efficiency and the mass transfer rate. Experimental values for efficiency are presented for a simple flow geometry. It is shown that readily achievable flow rates can produce the required thermal equilibrium of an 8m honeycomb mirror.
Irreducible inguinal hernia due to crossed testicular ectopia in an infant

The usual presentation of crossed testicular ectopia (CTE) is that of inguinal hernia with contralateral absent testis. We report on a 10-month-old infant with CTE, which presented as irreducible inguinal hernia. Diagnosis was made during surgery, as the child underwent an emergency operation for repair of his irreducible right inguinal hernia. A normal-sized and normal-shaped testis was found in the hernial sac with its blood vessels and vas deferens. A herniotomy with fixation of the ectopic gonad to the opposite hemiscrotum was done. The child remained asymptomatic 1 year postoperatively. Crossed testicular ectopia in infancy may present as irreducible hernia, requiring urgent surgery.
Iron Phosphates as Cathodes of Lithium-Ion Batteries

This study focusses on optimizing the parameters of the hydrothermal synthesis to produce iron phosphates for lithium ion batteries, with an emphasis on pure LiFePO4 with the olivine structure and compounds containing a higher iron:phosphate ratio. Lithium iron phosphate (LiFePO4) is a promising cathode candidate for lithium ion batteries due to its high theoretical capacity, environmentally benign and the low cost of starting materials. Well crystallized LiFePO4 can be successfully synthesized at temperatures above 150 °C. The addition of a reducing agent, such as hydrazine, is essential to minimize the oxidation of ferrous (Fe2+) to ferric (Fe3+) in the final compound. The morphology of LiFePO4 is highly dependent on the pH of the initial solution. This study also investigated the lipscombite iron phosphates of formula Fe1.33PO4OH. This compound has a log-like structure formed by Fe-O octahedral chains. The chains are partially occupied by the Fe3+ sites, and these iron atoms and some of the vacancies can be substituted by other cations. Most of the protons can be ion-exchanged for lithium, and the electrochemical capacity is much increased.
Fast voice-coil scanning optical-resolution photoacoustic microscopy

We developed a photoacoustic imaging system that has real-time imaging capability with optical resolution. The imaging system is capable of scanning at 20 Hz over a 9 mm range and up to 40 Hz over a 1 mm scanning range. A focused laser beam provides a lateral resolution of 3.4 μm as measured in an optically nonscattering medium. Flows of micrometer-sized carbon particles or whole blood in a silicone tube and individual red blood cells (RBCs) in mouse ear capillaries were also imaged in real time, demonstrating the capability to image highly dynamic processes in vivo at a micrometer-scale resolution.
An analysis of the hydraulic conductivity of the extracisternal space of the cochlear outer hair cell.

The cylindrically shaped cochlear outer hair cell (OHC) plays an important role in the transduction of acoustic energy into electrical energy in the cochlea. The extracisternal space (ECiS) of the lateral wall of the OHC is the fluid-filled space between the plasma membrane (PM) and the intracellular subsurface cisterna (SSC). In the ECiS, an array of cylindrical micropillars extends from the SSC to the PM. We obtain equations for the pressure, osmotic concentration and fluid velocity in the ECiS from the Brinkman-Stokes equations for steady incompressible flow in a plane channel that encloses an array of cylinders and whose upper wall, i.e. the plasma membrane, has a hydraulic conductivity of P(PM). From these equations we obtain an estimate for the hydraulic conductivity of the ECiS, P(ECiS). We show that the ECiS geometry accounts for P(ECiS) being several orders of magnitude larger than P(PM) and that P(ECiS) increases with the width of the ECiS and decreases with the length of the ECiS.
Investigation of Antimicrobial and Lipid Perturbing Properties of Lactoferrin Peptides

An increase in bacterial resistance to conventional antibiotics has led to an intense search for alternative treatments. Lactoferricin B (FKCRRWQWRMKKLGAPSITCVRRAF), a peptide with potent broad-spectrum antimicrobial activity, is released by pepsin from bovine lactoferrin. A smaller amidated peptide, (LfB6; RRWQWR-NH2), has been identified as having the core antimicrobial activity (Tomita et al. (1994) Acta Paediatr Jpn. 36:585-91). The exact mechanism by which antimicrobial peptides interact with bacterial cell membranes is not well understood, but it is proposed to depend on lipid composition. In contrast to mammalian membranes which are comprised primarily of neutral lipids, bacterial membranes contain a significant (∼20-25%) fraction of negatively charged lipids. In the case of LfB6, the presence of two tryptophans (W; Trp) and three arginines (R) are thought to promote selective interaction with bacterial cell membranes. Recently, we have shown that the antimicrobial activity of LfB6 peptides is increased by N-acylation and Trp-methylation (Greathouse et al. (2008) J. Pept. Sci. 14:1103-1110).To ascertain whether LfB peptides perturb lipids with negatively charged head groups, macroscopically aligned bilayers composed of lipids to mimic bacterial cell membranes have been prepared in the absence and presence of peptide. The samples are composed of neutral (POPE) and anionic (POPG) lipids (3:1), containing either sn-1 chain perdeuterated POPE-d31 or POPG-d31. The effects of LfB6 and amino acylated LfB peptides on lipid dynamics are being investigated by solid-state deuterium NMR spectroscopy and differential scanning calorimetry. The 2H NMR spectra reveal that the addition of LfB6 results in slight but specific changes in the outer quadrupolar splittings, which result from the methylene groups closest to the lipid head groups. Antimicrobial assays against S. aureus and E. coli demonstrate that the activity of N-acylated LfB peptides increases with acyl chain length.
Effect of early malnutrition on the reaction of adult rats to aversive stimuli.

A GREAT deal of interest has been shown in the relationship between early malnutrition, especially protein–calorie malnutrition, and intellectual capacity or learning ability. But early malnutrition may cause other changes in behaviour. An animal's motivation for food or water may be affected if it is deprived of them in early life1–4. In a non-appetitive situation Barnes et al.5 noted a “motivational and emotional” difference in previously malnourished rats in learning a water maze. Moreover, adult pigs which had been fed protein-poor diets early in life and then given a full diet took longer to extinguish a conditioned avoidance response than controls, although there was little difference in the rate of acquisition of the response6. This has also been reported in rats when there was more intertrial responding in previously malnourished animals7. We have investigated whether a brief period of malnutrition very early in life increases the emotional reactivity of the adult to aversive stimulation.
A Study of Fin Effects in the Measurement of Temperature Using Surface-Mounted Thermocouples

The present study addresses the effects of thermocouples on the measured temperature when such thermocouples are mounted directly on the surface of the object. A surface-mounted thermocouple is a very convenient way of measuring the surface temperature. However, the heat conduction into/from the thermocouple wire changes the local temperature at the thermocouple junctions along with the immediate vicinity of the thermocouple. As a consequence, the emf appearing at the thermocouple terminals does not correspond to the actual surface temperature. We first discuss the general characteristics of the enhanced heating/cooling due to the so-called fin effects associated with the surface-mounted thermocouples. An embedded computational model is then developed so that the model can be used in conjunction with a regular FEM model for the multidimensional calculation of the healing or cooling of a part
The CFTR Met 470 allele is associated with lower birth rates in fertile men from a population isolate.

Although little is known about the role of the cystic fibrosis transmembrane regulator (CFTR) gene in reproductive physiology, numerous variants in this gene have been implicated in etiology of male infertility due to congenital bilateral absence of the vas deferens (CBAVD). Here, we studied the fertility effects of three CBAVD–associated CFTR polymorphisms, the (TG)m and polyT repeat polymorphisms in intron 8 and Met470Val in exon 10, in healthy men of European descent. Homozygosity for the Met470 allele was associated with lower birth rates, defined as the number of births per year of marriage (P = 0.0029). The Met470Val locus explained 4.36% of the phenotypic variance in birth rate, and men homozygous for the Met470 allele had 0.56 fewer children on average compared to Val470 carrier men. The derived Val470 allele occurs at high frequencies in non-African populations (allele frequency = 0.51 in HapMap CEU), whereas it is very rare in African population (Fst = 0.43 between HapMap CEU and YRI). In addition, haplotypes bearing Val470 show a lack of genetic diversity and are thus longer than haplotypes bearing Met470 (measured by an integrated haplotype score [iHS] of −1.93 in HapMap CEU). The fraction of SNPs in the HapMap Phase2 data set with more extreme Fst and iHS measures is 0.003, consistent with a selective sweep outside of Africa. The fertility advantage conferred by Val470 relative to Met470 may provide a selective mechanism for these population genetic observations.
Planning for Phonological GeneralizationAn Approach to Treatment Target Selection

Recent treatment efficacy research has shown that a clinician’s choice of treatment targets is an important factor affecting sound generalization by children with phonological impairments. In this ...
Evaluation of influence of sediment on the sensitivity of a unionid mussel (Lampsilis siliquoidea) to ammonia in 28-day water exposures.

A draft update of the U.S. Environmental Protection Agency ambient water quality criteria (AWQC) for ammonia substantially lowers the ammonia AWQC, primarily due to the inclusion of toxicity data for freshwater mussels. However, most of the mussel data used in the updated AWQC were generated from water-only exposures and limited information is available on the potential influence of the presence of a substrate on the response of mussels in laboratory toxicity tests. Our recent study demonstrated that the acute sensitivity of mussels to ammonia was not influenced by the presence of substrate in 4-d laboratory toxicity tests. The objective of the current study was to determine the sensitivity of mussels to ammonia in chronic 28-d water exposures with the sediment present (sediment treatment) or absent (water-only treatment). The chronic toxicity test was conducted starting with two-month-old juvenile mussels (fatmucket, Lampsilis siliquoidea) in a flow-through diluter system, which maintained consistent pH (� 8.3) and six concentrations of total ammonia nitrogen (N) in overlying water and in sediment pore water. The chronic value (ChV, geometric mean of the no-observed-effect concentration and the lowest-observed-effect concentration) was 0.36 mg N/L for survival or biomass in the water-only treatment, and was 0.66 mg N/L for survival and 0.20 mg N/L for biomass in the sediment treatment. The 20% effect concentration (EC20) for survival was 0.63 mg N/L in the water-only treatment and was 0.86 mg N/L in the sediment treatment (with overlapping 95% confidence intervals; no EC20 for biomass was estimated because the data did not meet the conditions for any logistic regression analysis). The similar ChVs or EC20s between the water-only treatment and the sediment treatment indicate that the presence of sediment did not substantially influence the sensitivity of juvenile mussels to ammonia in the 28-d chronic laboratory water exposures. Environ. Toxicol. Chem. 2011;30:2270-2276. # 2011 SETAC
X-ray absorption spectroscopic investigation of arsenite and arsenate adsorption at the aluminum oxide-water interface

We investigated the As(III) and As(V) adsorption complexes forming at the γ-Al2O3/water interface as a function of pH and ionic strength (I), using a combination of adsorption envelopes, electrophoretic mobility (EM) measurements, and X-ray absorption spectroscopy (XAS). The As adsorption envelopes show that (1) As(III) adsorption increases with increasing pH and is insensitive to I changes (0.01 and 0.8 M NaNO3) at pH 3–4.5, while adsorption decreases with increasing I between pH 4.5 and 9.0, and (2) As(V) adsorption decreases with increasing pH and is insensitive to I changes at pH 3.5–10. The EM measurements show that As(III) adsorption does not significantly change the EM values of γ-Al2O3 suspension in 0.1 M NaNO3 at pH 4–8, whereas As(V) adsorption lowered the EM values at pH 4–10. The EXAFS data indicate that both As(III) and As(V) form inner-sphere complexes with a bidentate binuclear configuration, as evidenced by a As(III)–Al bond distance of ≅3.22 A and a As(V)–Al bond distance of ≅3.11 A. The As(III) XANES spectra, however, show that outer-sphere complexes are formed in addition to inner-sphere complexes and that the importance of outer-sphere As(III) complexes increases with increasing pH (5.5 to 8) and with decreasing I. In short, the data indicate for As(III) that inner- and outer-sphere adsorption coexist whereas for As(V) inner-sphere complexes are predominant under our experimental conditions.
Characterization of the spatial-frequency spectrum in the perception of shape from texture.

The major cue to shape from texture is the compression of texture as a function of surface curvature [ J. Exp. Psychol.13, 242 ( 1987); Vision Res.33, 827 ( 1993)]. A number of computational models have been proposed in which compression is measured by detection of changes in the spatial-frequency spectrum [ Comput. Graphics Image Process.5, 52 ( 1976)]. We propose that the visual system uses a strategy of characterizing the frequency spectrum by a simple set of measures and of tracking the changes in this characterization rather than determining changes in the shape of the actual spectra. Our evidence is based on a number of psychophysical demonstrations that use stimuli with specifically tailored frequency spectra, constructed from white noise filtered in the frequency domain. Our evidence suggests that the visual system determines the average peak frequency of the spectrum and uses this measure as its characterization. Changes in fp¯ are strongly correlated with the degree of surface curvature, and, over a range of stimuli, fp¯ takes account of the variance in local estimates of the frequency spectrum. One computes f¯p by determining the peak frequency at each spatial location and then averaging these frequency values over a local spatial region. We show that f¯p is related to the second-order moment but is more biologically plausible and shows superior ability to function in the presence of noise. As a test of this model, we have constructed a neural network architecture for computing shape from texture. Our model is limited to orthographically projected, homogeneous textures without in-surface rotation. The early stages of the model consist of multiple simple-cell units tuned to different orientations and spatial frequencies. We show that these simple cells are inadequate for the determination of compression but that the outputs of complex-cell-like units after normalization generate estimates of surface slant and tilt. The network shows qualitative agreement with human perception of shape from texture over a wide range of real and artificial stimuli.
When does spontaneous sarcoplasmic reticulum CA(2+) release cause a triggered arrythmia? Cellular versus tissue requirements.

Ventricular arrhythmias are a major cause of sudden premature death in patients with ischemic heart disease, hypertrophy, and congestive heart failure. The processes that initiate these arrhythmias include reentry, abnormal automaticity, and triggered activity.1 2 In the past three decades, there has been substantial investigation into each of these processes.3 4 This discussion will focus on triggered activity caused by delayed afterdepolarizations (DADs). Triggered activity has been widely studied for more than 20 years in whole hearts, isolated myocytes, and muscle and in Purkinje fiber preparations.5 6 Two general types of triggered afterdepolarizations have been observed and characterized. Early afterdepolarizations occur during the plateau phase of long-duration action potentials (APs). These secondary depolarizations involve either reactivation of the L-type Ca2+ channel or Na+ channel.6 7 DADs occur after repolarization of the AP to the resting potential and are caused by spontaneous release of Ca2+ from the sarcoplasmic reticulum (SR).6 8 9 10 11 12 The resulting elevation of cytosolic free Ca2+ activates inward current(s) that causes diastolic depolarization. When DADs are of a sufficient magnitude, an AP is induced. In the intact heart, these APs can propagate throughout the myocardium to cause extra heartbeats. In addition, if they find the ventricle in a partially refractory state or with conduction abnormalities, these APs can lead to tachyarrhythmias and fibrillation. It is well established that DADs result from spontaneous Ca2+ release from a Ca2+-overloaded SR.9 10 11 Many early studies of DADs used cardiac glycosides to increase cellular and SR Ca2+ and induce Ca2+ overload. It is now clear that many other factors including hypoxia, ischemia, increased sympathetic nerve activity, sympathomimetic drugs, hypertrophy, and heart failure can produce Ca2+ overload and DADs.10 In whole hearts, …
WHEN DO IDEAS MATTER? Explaining the Successes and Failures of Thatcherite Ideas

The field of comparative politics has begun to take seriously the role of ideas in politics, but to date this interest has not clearly specified the conditions under which ideas influence public pol- icy. The author develops an integrated framework that shows ideas about policy goals and instru- ments are most influential when they do not attract substantial opposition from voters and inter- est groups and when political institutions concentrate decision-making authority. The author tests this framework by examining the fates of three ideas, facing different degrees of societal opposition and concentrated authority, adopted by the first Thatcher government in Britain.
Experimental examination of a prevaporized premixed combustor

An experimental prevaporizing/premixing combustor configuration was examined. Evaluation of the combustor configuration was accomplished by extracting gas samples at discrete locations from within the combustor and analyzing them for unburned hydrocarbons, CO, CO2, and O2. These data were used to calculate local combustion efficiency and temperature. Contour plots were developed to interpret the gaseous flowfield. Results indicate two distinct regions of combustion: one in the recirculation zone providing constant ignition of incoming air/fuel mixture, and another where vitiated air impinges on the burning air/fuel mixture downstream of the ignition source.
Undersampling Taxa Will Underestimate Molecular Divergence Dates: An Example from the South American Lizard Clade Liolaemini

Methods for estimating divergence times from molecular data have improved dramatically over the past decade, yet there are few studies examining alternative taxon sampling effects on node age estimates. Here, I investigate the effect of undersampling species diversity on node ages of the South American lizard clade Liolaemini using several alternative subsampling strategies for both time calibrations and taxa numbers. Penalized likelihood (PL) and Bayesian molecular dating analyses were conducted on a densely sampled (202 taxa) mtDNA-based phylogenetic hypothesis of Iguanidae, including 92 Liolaemini species. Using all calibrations and penalized likelihood, clades with very low taxon sampling had node age estimates younger than clades with more complete taxon sampling. The effect of Bayesian and PL methods differed when either one or two calibrations only were used with dense taxon sampling. Bayesian node ages were always older when fewer calibrations were used, whereas PL node ages were always younger. This work reinforces two important points: (1) whenever possible, authors should strongly consider adding as many taxa as possible, including numerous outgroups, prior to node age estimation to avoid considerable node age underestimation and (2) using more, critically assessed, and accurate fossil calibrations should yield improved divergence time estimates.
Electronic fluctuations in nanotube circuits and their sensitivity to gases and liquids.

The temperature-dependent noise of individual, single-walled carbon nanotubes is measured here in a variety of different gases and liquids. The ambient environment is found to have only a weak relationship with device noise, even in cases where adsorption significantly changes the dc resistance. Correspondingly, a 450 K degassing procedure typically reduces the device noise by only 1 order of magnitude. An important exception to this finding is a pronounced, 100-fold increase in noise observed near gas -liquid phase transitions of the ambient. Wide-range temperature scans clearly identify the condensation of N 2 ,H 2, and CH4 onto metallic nanotubes, but not the sublimation of CO2. The observations suggest that nanotube devices can directly transduce ambient density fluctuations, though without an inherent gas specificity. Even so, the method is a particularly sensitive characterization of nanotube chemical interactions, one which is successful even for the extreme case of inert gases adsorbed on metallic nanotubes. Field-effect transistors, chemical sensors, and field emission sources and displays 1 are three carbon nanotube (CNT) research areas seeing preliminary commercialization efforts. In all three applications, and particularly in the first two, high levels of electronic noise threaten commercial viability. The noise levels of CNT devices are substantially higher than those in macroscopic films or materials of comparable resistance, 2 so controlling noise may be critical to the success of these applications. Despite this potential hurdle, noise sources in CNTs have remained relatively poorly characterized, particularly in comparison to the low temperature, quantum properties of these circuits. While the exact mechanisms have not yet been identified, the observed noise magnitude of CNTs 2-6 is compatible with the empirical Hooge observation 7 that 1/f noise scales inversely to the number of carriers in a system. Large amplitude noise is common in nanoscale circuits, 8,9 and a typical single-walled nanotube (SWNT) conductor 100 nm long incorporates less than 10 000 atoms and even fewer free carriers. The Hooge law predicts a 1/f noise singularity in very small circuits which is of interest from both fundamental and applied points of view, and SWNT circuits represent an ideal model system to further examine this issue. 9